Absorbing product, containing composite material
SUBSTANCE: claimed invention relates to an absorbing product, containing a lyophilised composite material. The lyophilised composite material contains a cellulose mass and an absorbing material, in which the said absorbing material contains microfibrous cellulose in the form of an absorbing porous foam-material. The content of carboxylate groups in the said microfibrous cellulose (MFC) constitutes from 0.5 to 2.2 mmol/g MFC.
EFFECT: increase of the mechanical strength and absorbing characteristics of the composite material is provided.
17 cl, 13 dwg, 11 tbl
The technical field TO WHICH the INVENTION RELATES
The present invention relates to an absorbent product containing the composite material. The composite material comprises an absorbent material in the absorbent porous foam. A composite material obtained from a renewable source of pulp.
The state of the art TO WHICH the INVENTION RELATES
Advances in technology absorbing products stimulated the search for absorbent materials with desirable properties, such as high absorbency, large storage capacity and high mechanical strength.
Absorbent products such as diapers, attached to the undergarment pads, incontinence pads, sanitary napkins and similar articles of a kind normally include ultra-absorbent material distributed within a fibrous matrix. Ultra-absorbent polymers (SAP) are karosserie hydrophilic polymers that have the ability to absorb and retain large amounts of liquid relative to their own mass. Thus, SAP is widely used in absorbent articles to improve their absorbency.
Various SAP materials for use in absorbent products, including synthetic and natural SAP. Natural materials, still� as pectin, starch and materials based on cellulose, usually suffer from poor absorbing properties and low mechanical strength and, thus, not widely used in absorbent articles. On the other hand, a synthetic material, such as SAP on the basis of polyacrylic acids/polyacrylates, receive, mainly from non-renewable raw materials, such as materials based on oil, and they are generally not considered favorable for the environment.
Non-renewable nature of SAP on the basis of polyacrylates is a source of growing public concern, and it is desirable to detect a biodegradable and renewable material, which according to its absorbent characteristics is similar synthetic materials SAP.
Concern about the environment has led to several attempts to use cellulose, which is a biodegradable and renewable resource. For example, patent application U.S. No. 2003/0045707 describes ultra-absorbent polymer made from cellulosic, lignocellulosic, or polysaccharide material, where the polymer is preferably a sulfonated to increase its swelling capacity in water. International patent application WO 97/21733 describes swelling in water insoluble sulfonated, cellul�Zou, in which the average degree of substitution by sulforaphane is from about 0.2 to about 0.5.
In recent years, the microfibrous cellulose (MFC) has received considerable attention in various applications. This is due, in particular, with its high mechanical strength and resistance.
For example, European patent No. 0210 570 describes absorbing and retaining the pulp mass, obtained by the introduction of microfiber pulp in sporoobrazuyushchie particles and cross-linking cross-linking reagent.
Similar approaches describe in U.S. patent No. 4 949 474 and European patent No. 0 209 884, where absorbing and retaining the pulp mass produced mechanical processing of cellulose fibers in microfiber form and lyophilization pulp.
Due to the growing interest in replacing traditional materials SAP based on polyacrylates more environmentally friendly alternatives there is a need to create alternative natural ultra-absorbent materials based on cellulose. Such material must be mechanically stable and exhibit improved absorbency characteristics that make them suitable for implementation in absorbent products.
Summary of the INVENTION
One objective of the present invention is to satisfy vishey�related need and offer absorbent product containing with a high absorbency material which exhibits excellent absorbing properties and high mechanical strength, and the material derived from renewable cellulose-based.
These and other objectives of the present invention are achieved with an absorbent article described in the attached claims.
Thus, in one aspect, the present invention relates to an absorbent product containing the lyophilized composite material. Composite material contains cellulose mass and absorbent material.
Absorbent microfiber material contains cellulose in the form of an absorbent porous foam. In microfibrous cellulose (MFC) the content of carboxylate groups ranges from 0.5 to 2.2 mmol/g of MFC.
Absorbent material according to the present invention exhibits excellent stability and absorption properties and is good for the environment.
The authors present invention found that by adjusting the number of charged groups, i.e. carboxylate groups in the cellulose chains MFC improving the characteristics of the porous structure of the foam. The stability of porous foam material is increased and improved its absorbing properties.
Typically, the absorbency increases�tsya with the number of charged groups. However, with a high content of charged groups in MFC, i.e. above 2.2 mmol/g, thin fibrils become more prone to fracture, which is undesirable. On the other hand, if the content of charged groups is excessively low, the material tends to be less "foam-like", and it makes the grid much more lyophilized cellulose fibers. This material is less resistant when wet and is fragile.
Containing from 0.5 to 2.2 mmol/g of charged groups, i.e., carboxylate groups, the foam has a high content of fine pores capable of holding large quantities of liquid, which, in turn, leads to a good speed of absorption and capillary leaking.
Microfibrous cellulose (MFC) gives mechanical strength and stability of the foam, "locking" the structure of the foam and making it less prone to breakage.
Composite material according to the present invention described above contains an absorbent material and freeze-dried pulp weight. The authors present invention found that the effectiveness of absorbent material may increase when it is present in the form of a composite. A porous foam material that gives stability to the fibrous mesh pulp and, thus, also to�Positano material as such.
To ensure similar absorbency requires less absorbent material in the composite, which is considered due to the positive synergistic effect between the components of the composite. If these two components are used separately and wet, absorbent material may be unable to withstand the high compression pressure, and a fibrous mesh pulp can be separated. However, in the form of a composite absorbent material will act as "glue" to form a very strong bond between the fibers in the mesh. Thus, it appears relatively rigid material that is able to withstand high compression forces. This, in turn, leads to the fact that the absorbent material will not be subjected to high compression forces, and, thus, can be used for holding liquids over a significant portion of the material.
The composite material consists mainly from renewable sources, i.e. materials based on cellulose, and thus represents an environmentally friendly alternative when used in hygienic products instead of traditional fibrous structures containing ultra-absorbent polymers on the basis of oil.
The composite material may contain at least 5 wt.% adsorbent material. Preferably,the composite material contains from 10 to 50 wt.% absorbent material, for example from 10 to 30 mass%. The authors present invention found that even small amounts of absorbent material provides good absorption and properties in compression of the composite material. Since the pulp usually is an inexpensive material, the composite material also has the advantage from an economic point of view.
Preferably the pulp is chemicomechanical cellulose pulp (CTMP). Composite material containing CTMP, has high mechanical strength and high bulk density in the wet state. Preferably, the content of charged groups in microfibrous cellulose is from 0.8 to 1.8 mmol/g of MFC. This leads to increased stability of the foam and superior absorbency.
The content of carbonyl groups in microfibrous cellulose is preferably at least 0.2 mmol/g, preferably at least 0.5 mmol/g of MFC. Carbonyl groups increase the stability not only of the absorbent material, but also a composite material. These groups can form interfibrillar covalent bonds inside the porous structure of the foam, as well as between the fibers of the cellulosic fibrous mesh. The result is a high mechanically stable structures�.
The absorbent material according to the present invention the specific surface area by BET method is at least 24 m2/g, preferably at least 30 m2/G. This provides a large specific surface area that becomes available for liquid, and increases the degree of comminution of the solid phase of the foam. Accordingly, this affects the absorbency properties of the material. Improving, for example, capillarity, i.e., capillary suction that is able to provide good retention of fluid, and may also be provided with a capillary leaking of the fluid inside the foam structure.
The absorbent material volume weight in the wet state is at least 10 cm3/g at 5 kPa, preferably at least 15 cm3/g at 5 kPa. Accordingly, the absorbent material, i.e. porous absorbent foam is mechanically stable under load, i.e. it has the ability to hold large quantities of liquid and is not destroyed when exposed to excess water.
In addition, the absorbent material according to the present invention, the value of the ability of free swelling (FSC) is at least 45 g/g. It exhibits good absorbency absorbent material according to this image�meniu.
In addition to the good properties of absorption of liquids, the absorbent product according to the present invention also exhibits good capacity retention of fluids. The absorbent material, i.e. porous foam, holding capacity by centrifugation (CRC) in determining the holding ability test when centrifugation is at least 8 g/g, preferably at least 12 g/g. Thus, the foam has the ability to firmly grasp and hold the liquid inside the pores and cavities of the foam.
The composite material can be obtained:
(a) oxidizing a first cellulosic mass to obtain a content of carboxylate groups of from 0.5 to 2.2 mmol/g pulp).
(b) crushing the specified first pulp mixture into microfibrous cellulose;
(c) mixing microfibrous cellulose after stage b) with the second pulp weight;
(d) lyophilizer specified blend of microfibrous cellulose and the second pulp;
(c) mixing microfibrous cellulose after stage b) with the second pulp weight;
(d) lyophilizer specified blend of microfibrous cellulose and said second pulp.
The result is a freeze-dried composite material in which the absorbent foam material distributed within the cellulose�Oh the fibrous structure. Finely porous structure is formed in the space between the larger fibers. Obtained as described above, the composite material is mechanically stable and does not require any additional cross-linking reagents, to bond the particles of the material. Such cross-linking reagents, usually required to bond the particles of the conventional structure microfiber materials.
Microfibrous cellulose and a second cellulosic mass is usually mixed in the wet state.
In embodiments, the stage of oxidation (a) is carried out in the presence of (2,2,6,6-tetramethylpiperidine-1-yl)Axela (TEMPO). This method provides a selective oxidation oxidation and adjustable, aimed primarily at the hydroxyl group at carbon atom 6 of cellulose chains. It also provides the formation of carbonyl groups, which, as mentioned above, contribute to the sustainability of absorbent foam material.
Absorbent product according to the present invention, typically contains permeable to liquids top sheet, bottom sheet and an absorbent mass, nested between permeable to liquids top sheet and bottom sheet. The absorbent mass is present composite material containing absorbent material.
Because of the porous absorbent foam has a multi - �ranked absorbent properties with respect to absorption, capture and retention of fluid, the composite material may also act as an absorbent layer that distributes the liquid accumulating layer and the liquid layer.
Absorbent mass or at least one layer may contain fractions of the composite material mixed with a second absorbent material. This configuration can improve the distribution of fluid within the absorbent mass.
These and other aspects of the present invention will become apparent and understood after reading further described variants (a variant of) its implementation.
BRIEF description of the DRAWINGS
Fig. 1 shows obtained by the method SEM structure of the absorbent porous foam material according to the present invention (1a) in comparison with the comparative material (1b). Fig. 1c illustrates obtained by the method SEM structure of composite material according to the present invention.
Fig. 2a illustrates a volumetric mass of wet absorbent material according to the present invention in comparison with comparative material.
Fig. 2b illustrates a bulk density in the wet state (5,2 kPa) of the lyophilized composite material obtained from different types of fibers from pulp and with different amounts of these fibers compared to writing�mi values for each material.
Fig. 3 illustrates the ability of the free swell absorbent material according to the present invention in comparison with comparative material.
Fig. 4a illustrates a holding capacity by centrifugation absorbent material according to the present invention in comparison with comparative material.
Fig. 4b illustrates a holding capacity by centrifugation absorbent material in combination with cellulose fibers in lyophilized composite material.
Fig. 5a is a flow diagram of the manufacture of absorbent material according to the present invention.
Fig. 5b is a process diagram of a possible method of manufacturing a composite material according to the present invention.
Fig. 6 illustrates the full accumulated amount of the liquid depending on the pore radius.
Fig. 7 illustrates an absorbent product according to the present invention.
Fig. 8 illustrates an absorbent product according to the present invention in cross section through the midpoint of the product.
DETAILED description of the INVENTION
The present invention relates to an absorbent product containing absorbent material. Absorbent material contains a lyophilized microfibrous cellulose in the form of absorbent p�istogo foam. Lyophilized microfibrous cellulose (MFC) contains charged groups in an amount constituting from 0.5 to 2.2 mmol/g of MFC.
Absorbent material contained in a lyophilized composite material, which also contains cellulose mass.
The term "absorbent product" includes any type of absorbent hygiene products such as diapers, sanitary incontinence products, feminine hygiene products such as sanitary napkins, and similar products. It may also include any type of paper napkins and towels for hygiene of the face, toilet paper, absorbent paper towels and handkerchiefs.
The term "lyophilized composite material" means the freeze-dried structure containing at least two distinct components: an absorbent material in the form of a porous foam and cellulose mass. These components are connected to each other sustainable interfibrillar bonds and remain in the composite are separate and distinct on a microscopic level. The components of the composite are usually mixed in the wet state. Other components may also be present in the composite.
When used herein the term "porous" means a material that contains pores and allows the flow of gas or liquid through the pores.
The term "p�nomaterial" means a material educated in the capture of gas bubbles in a liquid or a solid. The term "foam" when used in the present invention means a structure obtained by capturing the domains of water in the solid and its subsequent evaporation of water using the lyophilization method.
Absorbent material according to the present invention is an "absorbent porous foam", which is a solid foam comprising a continuous phase on the basis of the microfibrous cellulose that surrounds the pores are connected with one another and form an interconnected porous system.
The term "microfibrous cellulose" or "MFC" when used herein means having a small diameter and a high ratio of length to diameter of the substructure. Free and individual fibers, as a rule, the diameter is from 5 nm to 300 nm, preferably from 5 nm to 100 nm at all points along the fiber. The diameter may vary along the length of the fiber. Microfibrous cellulose can exist in the form of free and individual fibrils and/or in the form of free clusters of these fibrils.
Microfibrous cellulose can be produced from any source of cellulose, including, without limitation, wood fibers, for example, obtained from deciduous and coniferous wood, such�EP, from chemical pulps, mechanical pulps, thermomechanical pulps, chemicomechanical the pulps, recycled fibers, the fibers of plant seeds, leaf fibers, straw fibers or cellulose fibers produced by bacteria.
Absorbent porous foam material for the product according to the present invention is made from a renewable source (cellulose) and thus represents an environmentally friendly alternative to traditional SAP materials based on polyacrylates. Due to their good properties of absorption, retention and accumulation of fluids it is suitable for implementation in any type of absorbent products.
Charged groups that are present in the foam, i.e., microfibrous cellulose, increase the osmotic pressure so that the liquid effectively and quickly absorbed into the foam. This, in turn, may affect the capillary force required to hold the liquid within the foam structure. Accordingly, the absorbent material used to improve the properties of absorption, distribution and accumulation of fluid absorbing product according to the present invention.
When used herein the term "charged group" refers to any negatively W�costumed group. Typically, the charged groups are carboxylate groups. Such carboxylate group can be obtained by oxidation of the cellulose chain, preferably at the 6 carbon atom, i.e. the carbon atom, which contains a free hydroxyl group (marked with *below).
The content of charged groups such as carboxylate groups, defined as the molar number per gram of microfiber cellulose or per gram of pulp and expressed in mmol/g.
The number of charged groups comprising from 0.5 to 2.2 mmol/g of MFC, has proved useful in ensuring desirable absorbent properties.
In this interval the absorbent material is a porous foam having a high content of small pores that are capable of capturing a large amount of fluid that, in turn, leads to increased infiltration rate and increase the ability of capillary wicking, i.e. the ability of the foam to distribute the liquid inside the foam.
However, the content of charged groups should not exceed 2.2 mmol/g, since an excess of charged groups may give MFC increased susceptibility to fracture, which is undesirable. On the other hand, if the content of charged groups is excessively low, for example, mills�tsya below 0.5 mmol/g, the material tends to lose its characteristics as a foam and, as a rule, contains a larger fiber with a large degree of external education of the fibers (see Fig. 1b).
Lyophilized microfibrous cellulose imparts mechanical strength and stability of porous foam material and has the ability to "lock" the structure of the foam. Believe that the high stability of the absorbent porous foam material according to the present invention arises from a particularly strong hydrogen bonds between the thin and flexible fibrils microfibrous cellulose, which strengthens the structure of the foam. In addition, the foam stability can be attributed to the presence of carbonyl groups in microfibrous cellulose. These groups can provide crosslinking between the MFC fibrils, which are used to increase the stability of the material through the formation of interfibrillar covalent bonds within the absorbent porous foam material.
Absorbent porous foam material contains pores and cavities which are connected to each other, forming a fine interconnection network. This foam is stable both in dry and in wet condition and not falling apart under the pressure.
Composite material according to the present invention contains described� above the absorbent material, called herein the term "absorbent material", and the pulp mass. These two components are preferably mixed in the wet state and then lyophilizer. The result is formation of a very strong fibrous connection between cellulosic fibers and absorbent material. Absorbent material, i.e. porous absorbent foam, is distributed among a larger lyophilized cellulose fibers and serves as the "glue" bonding together particles of the material.
The authors present invention found that the composite material according to the present invention has a very good absorbency under pressure, illustrating the high bulk density in the wet state in Fig. 2b. In addition, the composite material makes more efficient use of the holding capacity of the absorbent material compared to absorbent material in a pure form (see Fig. 4b).
Consider that the pulp fibers in combination with absorbent material to improve the mechanical properties of the composite material so that the structure is able to withstand high mechanical stresses. The material can be compressed to high density values and even to stretch when wet.
The presence of fibers of pulp in Lee�fileservername the composite may also improve the ability of a material to liquid distribution.
Composite material is unique in the sense that he is basically a material based on wood. However, its absorbent properties similar to the properties of absorbent structures containing ultra-absorbent polymers on the basis of oil.
The composite material may include at least 5 wt.% adsorbent material. Preferably the composite material contains from 0 to 50 wt.% absorbent material, for example, from 10 to 30 mass%. Even such small quantities of absorbent material are sufficient to ensure good absorbent properties. As mentioned above, the absorbent material acts as a "glue" in the intersections of the fibers and forms a very strong bond between the fibers in the mesh. Thus, it appears relatively rigid material that can withstand high compression forces. This, in turn, leads to the fact that the absorbent material will not be subjected to high compression forces, and thus, a larger portion of the material can be used for accumulation of fluid. Unexpectedly high bulk density in the wet state was observed even when using such small quantities of absorbent material.
Increased bulk density in the wet state was also observed when pulp is hemiatrophy�die cellulose pulp (CTMP), for example, high temperature chemicomechanical pulp mass (HTCTMP). CTMP is an inexpensive material, which typically has low absorbency. Thus, it is unexpected improved absorbent properties to the same extent for the composite containing CTMP. This can be attributed to the fact that this type of pulp is characterized by a large length of the fibers, a low content of small particles, the strength and stiffness of fibers.
Microfibrous cellulose absorbent material has a suitable content of charged groups, i.e. carboxylate groups comprising from 0.8 to 1.8 mmol/g of MFC.
In this interval were observed especially good absorbency. Foam structure contains many tiny interconnected pores and can absorb 180 times its own weight after immersion in water for 10 minutes. The absorption liquid is high (more than 150 times its own weight) after only 1 minute, which shows a remarkably quick absorption of liquid (see table 6).
This remarkable result is superior to traditional SAP materials based on polyacrylates, which typically exhibit low initial rates of absorption.
In microfibrous cellulose content of carbonyl groups is preferably, for IU�Isha least to 0.2 mmol/g of MFC, for example, at least 0.5 mmol/g of MFC. Carbonyl group capable of forming polyacetylene communication and acetaline communication in the reaction with hydroxyl groups present on the surface of MFC and fibers from the pulp. Thus, while increasing the stability of the absorbent material, and composite material.
The absorbent porous foam material according to the present invention the specific surface area by BET method is at least 24 m2/g, for example at least 28 m2/g, preferably at least 30 m2/g.
When used herein the term "specific surface area by BET method" or "specific surface area" is a measure of the available area foam, which affects the test liquid. Thus, it is a way of quantifying the total amount of solid surface, which has an absorbent porous foam.
When the foam material has a large specific surface area, the absorption is improved, and the liquid can also be more effectively used to maintain the foam structure. Specific surface area by BET method is defined as the available area (m2) per gram of foam. High specific surface area by BET method leads to the increased rate of absorption�Oia and capillarity, providing an acceptable retention of fluid and desirable capillary leaking, which occurs within the foam structure.
As illustrated obtained by the SEM image in Fig. 1a, the porous foam material according to the present invention has a very fine particle microfibrous cellulose in listopadova structure with large voids between them. This leads to the fact that when exposed to be the absorption of liquids available is a large surface area. As a result of increased absorption.
On the other hand, when the specific surface area by BET method is low, as illustrated in Fig. 1b, the smaller the surface area of the foam is available, and, accordingly, the absorption capacity decreases.
Another distinctive feature of absorbent material is that it has a high bulk density in the wet state. When used herein the term "bulk density in the wet state" means the volume in cubic centimeters per gram (dry substance) of absorbent material under load after saturation of the material with deionized water. Bulk density in the wet state correlates with the absorption under load. This test is intended to determine the effectiveness of the absorb�equation describing abilities for example, the diaper under load of the weight of the child.
The absorbent material according to the present invention the bulk density in the wet state is at least 10 cm3/g at 5 kPa, preferably at least 15 cm3/g at 5 kPa (see Fig. 2). Accordingly, the absorbent material has the ability to hold large quantities of liquid and is not destroyed when exposed to excess water. The foam can rapidly absorb and effectively distribute the liquid on the ground, remote from the place of impact.
The authors of the present invention unexpectedly found that the volumetric mass in the wet state is incremented when an absorbent material is contained in the composite material according to the present invention. This is unexpected and proves positive synergies between the cellulose fiber structure and absorbent material in a dried composite. Best results are obtained when used in the composite or CTMP HTCTMP (see Fig. 2b).
The absorbent material, i.e. porous absorbent foam material, meaning the ability of free swelling (FSC) is at least 45 g/g.
When used herein the term "power of free swell" or "FSC" means the ability of absorption for impregnation VPI�yvouxeo material with an aqueous solution of 0.9% sodium chloride for 30 minutes at room temperature, followed by shaking off excess fluid and weighing to determine the amount of moisture absorbed by the fluid. The ability of free swelling is expressed as grams of absorbed fluid per gram of dry mass of the sample.
As can be seen in Fig. 3, the power of free swell absorbency of the material is very high even after 1 minute and 5 minutes, respectively, and observed values up to 60 g/g. This demonstrates improved absorption rate and absorption of the liquid absorbent material. Such high values of FSC as a rule, not observed for traditional SAP materials based on polyacrylates, which, as mentioned above herein, typically exhibit a slow initial rate of absorption.
In addition to improving the properties of absorption of the liquid absorbent material for absorbent products according to the present invention also exhibits good ability of accumulation of fluid, which is measured in the test the holding capacity by centrifugation (CRC).
When used herein the term "holding capacity by centrifugation" or "CRC" is a measure of the ability of the foam to retain fluid within the absorbent material. Holding capacity by centrifugation measure, about�of itiva absorbent material with an aqueous solution of 0.9% sodium chloride for 30 minutes at room temperature and then centrifuger material for 3 minutes, to determine the number of retained fluid.
The absorbent material retention capacity (CRC) in determining the holding ability test when centrifugation is at least 8 g/g, for example at least 10 g/g, and preferably at least 12g/g. compared with the traditional pulp and weighing the CRC value increases significantly (see Fig. 4a).
The authors of the present invention unexpectedly found that the CRC absorbent material increases with increasing the number of fibers of the pulp in the composite. This means that the composite material makes more efficient use of restraint, the ability of the absorbent material compared to absorbent material in a pure form. As illustrated in Fig. 4b, a very high CRC values obtained at high concentrations of cellulose fibres, shows that the best preservation of the porous structure (less deterioration of the structure) at high levels of the additive fibers.
The absorbent porous foam material appropriate the full amount of accumulation is more than 5 mm3/mg, preferably more than 10 mm3/mg with a corresponding pore radius of 2 µm. The absorbent porous foam total accumulation could reach more than 20 mm3/mg, the preferred�Uo more than 40 mm 3/mg in the range of the corresponding pore radii of from 10 μm to 50 μm. Such a foam is useful because it contains larger voids that can provide the best transfer fluid, and smaller voids that have better properties retention.
Absorbent material, i.e. porous absorbent foam, the product according to the present invention can be obtained:
(a) oxidizing a first cellulosic mass to obtain a content of carboxylate groups of from 0.5 to 2.2 mmol/g pulp).
(b) pulping pulp mass in microfibrous cellulose;
(c) lyophilizer microfibrous cellulose.
The content of carboxylate groups can be measured and determined by any known method, for example by sorption of methylene blue. This method is further explained in the article P. Fardim, B. Holmbom, J. Karhu, Nordic Pulp and Paper Research Journal (Scandinavian journal cellulose paper studies), 2002, vol. 17, No. 3, pp. 346-351, which are incorporated in this document by reference.
Stage (a) can be done with an adjustable oxidation, using any type of oxidizing agent, i.e. the agent which oxidizes the hydroxyl group in the glucose units of the cellulose chains. For example, you can use the periodate sodium, or nitrogen dioxide. Alternatively, the pulp and the mass can be subjected�ü carboxymethylamino, in which monochloroacetic acid is reacted with hydroxyl groups of cellulose chains of the pulp, forming a charged group.
Oxidation can also be carried out through free-radical reactions. This reaction initiates the reaction with a catalytic agent, which produces a free radical. Oxidizing agent in the free radical reaction is a winner of the free radical, including, for example, hypohalite, such as lipophility, hypochlorites, hypobromites and lipoidica, preferably hypochlorites such as sodium hypochlorite (NaOCl), potassium hypochlorite (KOCl), lithium hypochlorite (LiOCl) or calcium hypochlorite (Ca(OCl)2). This list of examples of oxidizing agents is not exhaustive. The catalytic agent can be a peroxide or organic nitroxyl compound, such as (2,2,6,6-tetramethylpiperidine-1-yl)oxyl (TEMPO), 2,2,5,5-tetramethylpyrrolidine-N-oxyl (PROXYL), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl and 4-atsetamido-2,2,6,6-tetramethylpiperidine-1-oxyl, as well as their derivatives. These catalytic agents selectively react at carbon 6 of glucose level of cellulose molecule.
Before oxidation (stage a) cellulosic pulp can be cleaned, for example, additional stages of mechanical treatment before the stage of oxidation (a). This can be useful with regard to op�imitatie energy consumption of the process.
The presence of charged groups makes it easier to shred the pulp mass in microfibrous cellulose (stage b).
Stage of grinding pulp, as a rule, exercise, homogenizing pulp weight, getting thinner structure, i.e., microfibrous cellulose, for example, with an ultrasonic homogenizer. The required degree of homogenization depends on the number of charged groups, embedded in pulp. For example, if the content of charged groups is high, the homogenization time can be as little as one minute or a few minutes. On the other hand, if the content of charged groups is smaller, it may take time for the homogenization gap of more than 10 minutes. Microfibrous cellulose can be present in the form of individual MFC fibrils or their clusters.
The material obtained as a result of mechanical processing, in step (b) has a gel-like nature.
By lyophilization microfibrous cellulose get absorbent porous foam containing numerous interconnected pores and a thin MFC fibrils and their clusters. Other drying technologies, such as air drying, do not lead to such characteristics of foams.
Charged groups introduced into the cellulose mass at the stage (a) remain even after TSE�rulesnew pulp is subjected to mechanical treatment (stage b) and lyophilization (stage c), i.e. lyophilized microfibrous cellulose contains almost the same number of charged groups, as the pulp after step (a).
Composite material according to the present invention can be obtained:
(a) oxidizing a first cellulosic mass to obtain a content of carboxylate groups of from 0.5 to 2.2 mmol/g pulp).
(b) crushing the specified first pulp mixture into microfibrous cellulose;
(c) mixing microfibrous cellulose after stage b) with the second pulp weight;
(d) lyophilizer specified blend of microfibrous cellulose and the second pulp.
Stage (a) and (b) can be realized as described above. At the stage (c) microfibrous cellulose is mixed with a second cellulosic mass and then the mixture liofilizat.
The second pulp can be any type of weight based on the pulp, such as chemical, mechanical or thermomechanical pulp. Preferably the second pulp is chemicomechanical cellulose pulp (CTMP), for example high temperature chemicomechanical pulp mass (HTCTMP).
Fig. 1c illustrates a composite material obtained according to the method described above. The CTMP fibers imbedded in a matrix of absorbent material. Absorbent Mat�Rial has a large specific surface with small pores. The pores of the absorbent material will remain stored even when exposed to high pressures.
Preferably, stage (a) is carried out in the presence of (2,2,6,6-tetramethylpiperidine-1-yl)Axela (TEMPO). TEMPO is a preferred catalytic agent, because it provides a selective and controlled oxidation. The hydroxyl group at the 6 carbon atom in the cellulose chains of the pulp is preferably oxidized, forming a charged carboxylate groups in an amount constituting from 0.5 to 2.2 mmol/g pulp. This catalytic agent is stable during the reaction and can also be removed and recycled to the process that represents an important aspect from the point of view of both the economy and the environment. In addition, this method of oxidation does not cause any significant destruction of the cellulose chains of the pulp, which may occur in the case of other methods of oxidation.
You can also add socializaton, for instance bromides of alkali metals such as sodium bromide (NaBr), potassium bromide (KBr) and lithium bromide (LiBr).
During oxidation in the presence of TEMPO are formed carbonyl group, and these groups can improve resilience, forming interfibrillar covalent bonds within the absorbent porous foam. In this way�m, you can get a covalent linkage between the MFC fibrils, which are important for the conservation of the mesh fibers in the wet state. In conventional microfiber materials, as a rule, requires cross-linking reagents, to bond together the particles of the material. However, due to strong interfibrillar linkages formed within an absorbent porous foam material, cross-linking reagents are not required. The first pulp mass, preferably oxidize, getting the content of carbonyl groups constituting at least 0.2 mmol/g of MFC, for example, at least 0.5 mmol/g.
Interfibrillar covalent bonds contribute to the mechanical strength of the foam and the composite.
Fig. 5a schematically illustrates the method possible manufacturing an absorbent foam according to the present invention.
In the first stage (stage a), the reaction begins with the addition of an oxidant such as sodium hypochlorite (NaOCl), which can be added in a quantity amounting to approximately from 1.5 to 7.0, for example, from 2.0 to 6.0 mmol/g pulp. NaOCl reacts with, for example, sodium bromide (NaBr) to form hypobromite. The amount of NaBr can be, for example, from 0.2 to 8 mmol. Hypobromite then oxidizes 2,2,6,6-tetramethylpiperidine-1-yloxy (TEMPO), which promotes the oxidation of the hydroxyl groups at the carbon atom�and 6 of cellulose chains. The number of TEMPO may be, for example, from 0.01 to 0.5 mmol/g. At this stage, are formed negatively charged carboxyl groups, and carbonyl groups, which contribute to the absorbent properties and mechanical stability of the foam, respectively.
Alkaline compound such as sodium hydroxide (NaOH), is added to maintain a pH in the range from 8.5 to 10.5, so that the cellulose fibers is not destroyed and damaged to a significant extent during the reaction.
This method may optionally include the stage of leaching, where the pulp mass is washed and filtered to reuse the catalyst and oxidant, i.e. TEMPO, NaBr, etc., and to separate unwanted components of fibers and materials.
After oxidation of the cellulose mass is called by the term "TEMPO oxidized pulp" (TOP).
Then the TOP is subjected to mechanical treatment (stage b), i.e., homogenization, to grind the pulp mass in microfibrous cellulose. The resulting material is called the term "homogenisierung TEMPO oxidized pulp" (HTOP). Milling step can be accomplished in any way in which for the grinding of pulp fibers to the pulp and the mass attached to the force, for example mechanical beating.
Then HTOP lyophilizer, getting policyparameter, containing lyophilized microfibrous cellulose in which the content is charged from 0.5 to 2.2 mmol/g of MFC (stage c).
Fig. 5b schematically illustrates a method to manufacture a composite material according to the present invention. It includes the same steps as those shown in Fig. 5a, but additionally includes the stage of mixing, where homogenized TEMPO oxidized cellulose mass (HTOP) is mixed with a second cellulosic mass. Thereafter, the mixture liofilizat. Two materials are preferably mixed in the wet state prior to lyophilization, providing the formation of stable chemical bonds between the cellulosic fibers and absorbent material.
Composite material and absorbent porous foam preferably do not contain any traditional ultra-absorbent polymers (SAP). However, in the present invention, to introduce SAP in the composite or in the structure of the foam.
"The ultra-absorbent polymers are swellable in water water-insoluble organic or inorganic materials capable of absorbing at least about 20 times its mass of an aqueous solution containing 0.9 wt.% of sodium chloride. Any type of ultra-absorbent polymer (SAP), which is known to specialists in this about�lusty machinery, you can enter in the foam according to the present invention.
You can also enter additional components such as viscosity regulators and surfactants, to improve the stability of the foam.
Absorbent product 10 in the form of an open diaper shown in Fig. 7. Absorbent product 10 according to the present invention, typically contains permeable to liquids top sheet 11, the bottom sheet 13 and the absorbent mass 12, nested between permeable to liquids top sheet 11 and lower sheet 13. Composite material containing absorbent material, i.e. porous absorbent foam, is present in the absorbent mass 12.
Permeable to liquids top sheet 11 facing the wearer's body during use and is designed to absorb released from the body fluids such as urine and blood. The upper sheet material 11 may be, for example, non-woven spunbond material mode of production, the obtained aerodynamic method from the melt material from carded wool fiber, etc.
The bottom sheet 13, as a rule, is impermeable to liquids, not necessarily breathable, and it can represent, for example, plastic (e.g., polyolefin) film, coated with plastics or nonwoven hydrophobic netcon�th material.
Absorbent mass 12 is used for receiving and maintenance of fluid and other secretions of the body. Thus, it may contain an absorbent porous foam material, i.e. a composite material, and may contain additional absorbent materials. Examples usually occurring absorbent materials are cellulosic downy mass, tissue layers, ultra-absorbent polymers, other types of absorbent foams, absorbent nonwoven materials or similar materials.
Absorbent mass 12 may consist of several layers, such as the absorbent layer, the storage layer and distribution layer, to perform the functions that are desirable for the absorbent mass, i.e. have the ability to quickly absorb liquid, distribute it throughout the mass and hold.
Because the absorbent porous foam according to the present invention has a multi-functional absorbent properties regarding absorption, uptake and accumulation, the composite material according to the present invention can simultaneously perform absorbent layer that distributes the liquid layer and holding the liquid layer.
Thus, the absorbent mass 12 may contain at least one absorbent layer, the storage layer and Raspredelitelnaya or any combination, and the composite material is present at least in one of these layers or is it. The layers of the absorbent mass 12 are designed to absorb large amounts of fluid in a short time and its uniform distribution throughout the absorbent mass. Composite material according to the present invention may be present in one or more of such layers, and even in all layers. Absorbent mass may also be composed entirely of composite material.
The size and absorbent capacity of the absorbent mass 12 can be changed depending on different applications such as baby diapers, sanitary napkins and incontinence pads.
Fig. 8 is a cross sectional view of the absorbent product 10, such as a diaper, is shown in Fig. 7, through the midpoint of the product. It is permeable to liquids top sheet 11, the bottom sheet 13 and the absorbent mass 12, nested between permeable to liquids top sheet 11 and lower sheet 13. In a variant implementation, illustrated in Fig. 8, the absorbent mass 12 or at least one layer contains a fraction of a composite material containing absorbent material (porous foam) (number 14), mixed with the second absorbent material.
The second absorbent materialmade to be a traditional material, used in absorbent mass, for example, pulp and down mass, tissue layers, absorbent foams, absorbent nonwoven materials or ultra-absorbent polymers (SAP).
Accordingly, the composite material 14 is cut into small fractions or pieces that are placed in certain areas of the absorbent mass. When such fraction is mixed with the second absorbing material, for example a material containing ultra-absorbent polymer (polymers), it is possible to improve the circulation and capillary leaking of fluid within an absorbent mass or layer (s). This provides the advantage that the liquid is more effectively distributed inside the absorbent mass or layer.
MANUFACTURE of ABSORBENT MATERIAL ACCORDING to the INVENTION
Example 1. Oxidation of pulp
Added 12.0 g (kiln dried) bleached, not previously dried coniferous sulfonated pulp 1.20 l of a solution containing 0.1 mm TEMPO (a free radical (2,2,6,6-tetramethylpiperidine-1-yl)oxyl) and 1 mm NaBr (sodium bromide). After adding the pulp pH was adjusted to 10 using a solution of 1 M NaOH. The reaction was started by addition of certain amount of a solution of NaOCl (sodium hypochlorite), brought to pH 10. The amount of added NaOCl was different for the four samples obtained cellulosome (indicated by the letters A, B, C and D) as described in table 1, to obtain a pulp samples with different content of charged groups, i.e. carboxylate groups. The reaction was performed at room temperature in two-liter glass vessel, and the suspension was continuously stirred using a magnetic stirrer. To avoid a decrease in pH in the reaction process drops added a solution of 1 M NaOH, maintaining a pH in the range from 9.75 to 10,25. The reaction was stopped when no longer observed decrease in pH. Reaction time increased with increasing doses of NaOCl and amounted to a maximum of 150 minutes at 5 mmol NaOCl/g pulp.
After reaction, the pulp and the mass was placed in a Buchner funnel (Buchner) with nylon mesh (distance between threads is 200 μm, the diameter of the filaments 400 μm), and the liquid was separated from the oxidized pulp. The filtrate is once returned to reduce the loss of fine material. After that, the oxidized cellulose mass was washed using at least 0.4 l of deionized water per gram of mass.
|Sample||The NaOCl concentration (mmol/g pulp, dried in furnace)|
Oxidation of TEMPO radicals accelerates the oxidation of the hydroxyl groups at the 6 carbon atom in the cellulose chains as in carbonyl and carboxylate groups. After oxidation pulp termed "TEMPO oxidized pulp" (TOP).
Example 2. The content of charged groups
The content of charged carboxylate groups in the pulp samples after the oxidation step was determined by sorption of methylene blue. Approximately 0.05 g (kiln dried) TEMPO oxidized pulp was placed in a beaker containing 100 ml of a solution of 0.01 HCl. The suspension was stirred for 1 hour using a magnetic stirrer. After this, the pulp and the mass portion was washed with 50 ml of 0.01 M HCl and two portions of deionized water. To reduce the water content in the sample, it is thoroughly dehydrated. At the next stage, the dehydrated sample was placed in a beaker along with 100 ml of buffer solution containing methylene blue. Containing methylene blue buffer solution contained 0,002 M NaH2PO4 , 0,0078 M Na2HPO4(buffer solution brought to pH 7.8), 0,4798 g methylene blue and deionized water to volume of 1.00 L.
Sorption was carried out in the dark for 1 hour. After that the reaction liquid and the fibers were separated by filtration. The initial volume of the filtrate was diluted 125 times and analyzed using a spectrophotometer U-3200 Hitachi. The absorption was measured at 664 nm. The fiber was collected on a filter paper and then washed using 200 ml of 0.01 M HCl to be conducted in order methylene blue from fibers. After that the fiber was further washed with deionized water, dried in an oven at 105°C for at least 4 hours and then measured the mass of fibers. The content of charged groups was calculated based on the consumption of methylene blue and the weight of the fiber.
As shown in table 2, the content of charged carboxyl groups is increased by oxidation with TEMPO. Bleached softwood pulp without any treatment NaOCl termed "Comparative pulp I" in table 2. The hydroxyl group at the 6 carbon atom in the cellulose chain is selectively transformed into a charged carboxyl group.
The content of charged groups
|The NaOCl concentration (mmol/g pulp, dried in furnace)||Charged groups (mmol/g)|
|Comparative pulp I||0||0,07|
Example 3. Mechanical treatment of the oxidized pulp
Oxidized TEMPO samples of pulp, are shown in table 2, are then mechanically processed by homogenization.
Suspended 5.0 g TOP in water in a plastic laboratory glass, getting a solids content equal to 1%.
Then TOP homogenized using vysokoduhovnym laboratory batch mixer, such as Ultra-Turrax T 45/N firm IKA WERK (speed 10000 rpm, rotor diameter of 40 mm, the diameter of the stator 45 mm). Fiber in the pulp mass was ground, getting even smaller particles.
After machining, the material is transformed from a hydrophilic� pulp in the material more like a gel. This material is termed "homogenisierung TEMPO oxidized pulp" (HTOP). All terms of mechanical processing herein is based on samples weighing 5 g (dry matter).
Table 3 presents the final solids content for each of the samples. Samples were taken after 1, 3, 5, 10 and 15 minutes, respectively.
The solids content (%) in samples homogenized TEMPO oxidized pulp
|1 min||3 min||5 min||10 min||15 min|
In the homogenization process, the slurry viscosity increased. Some of the suspensions (HTOP (C and D) become overly viscous, so that the formed dead zones in a laboratory beaker with the sample. To ensure good mixing of the entire volume of data samples, their portion was diluted with deionized water, providing further processing.
In the process liberated fibrils were suspendirovanie due to the presence of charged carboxylate groups.
Samples HTOP A and B were taken after 1 min and 3 min, because the data samples of the pulp were not so easy to grind (due to the low content of charged groups).
Example 4. Fractionation of fibres
Fractionation of long and short fibers in the samples HTOP presented in table 2, was performed to show the relative ease of pulverization of fibers.
In a beaker was placed 10 g samples HTOP presented in table 2, whose concentration was varied from 0.5 to 1%.
After this was added 80 ml of deionized water and 10 ml of a solution of 0.1 M HCl. Then the suspension was slowly stirred magni�Noah agitator for 1 hour. When you add acid protonirovanii acidic carboxyl groups, which contributed to the release of individual fragments of the fibers in the slurry. Before the actual fractionation pH was adjusted to 7 by adding drops of a solution of 0.5 M NaOH.
Comparative number of long and short fibers was determined by separation of fractions of fibers, using a Dynamic Drainage Jar (dynamic drain receptacle) is manufactured by Paper Research Materials. Dynamic Drainage Jar, manufactured by Paper Research Materials, consists of a vessel with a device for mixing a metal conical sieve with holes (used a metal mesh 40M, which is approximately equivalent to a regular square mesh of 50 mesh (297 μm)) and a plastic tube at the bottom to collect the filtrate (not used glass bottom cone).
Then the sample was diluted to volume, amounting to approximately 500 ml using deionized water. The diluted sample was injected into the discharge vessel with a closed bottom tube) and started stirring by for 15 s at 1500 rpm (revolutions per minute). Then the mixing speed was reduced to 750 rpm and opened the bottom up to drain the water and short fibers in a beaker. After draining the collected fraction of short fibers and the fraction of long fibers, and both fractions were diluted yielding� the total mass of each suspension, equal to 500 g. the Content of solid particles in the suspensions was determined by allocating the solid material by filtration and weighing it after drying at 105°C for four hours.
Table 4 presents the percentage fraction of short fibers, i.e., the fraction that has microfibrous cellulose. Time in the names of the samples means the time of machining.
Comparative pulp I is a bleached softwood pulp weight (without oxidation and without mechanical processing).
Comparative pulp II is a bleached softwood pulp mass, processed by homogenization for 15 minutes.
The fraction of short fibers
|Sample||The fraction of short fibers (%)|
|Comparative pulp I||32|
|Comparative pulp II||41|
|HTOP A_10 min||24|
|HTOP B_10 min||54|
|HTOP C_10 min||81|
|HTOP D_1 min||41|
|HTOP D_3 min||69|
|HTOP D_10 min||77|
|HTOP D_15 min||80|
Table 4 shows how the mechanical grinding increases with the increase in the content of carboxylate groups. More material is transferred from the fraction of long fibers in a fraction of the short fibers. In addition, the grinding pulp in MFC by homogenization contributes to longer machining.
Example 5. Lyophilization microfibrous cellulose
The samples of example 4 were successively subjected to lyophilization, quickly freezing the samples in a glass laboratory beaker with liquid nitrogen. After that the beaker was placed in a freeze dryer Hetosicc CD of 2.5 from the company Heto at a pressure of 0.3 to 0.5 mbar (30-50 PA) and water were removed by sublimation. The lyophilization time was 60 hours to ensure dryness of the samples.
The resulting material was a porous foams with slightly different characteristics of the foam depending on the number of charged groups and lyophilization. This material is termed "freeze-dried homogenisierung TEMPO oxidized cellulose wt�a (FD - HTOP).
The characteristics of the absorbent foam
Example 6. The distribution of pore volume and total total
The distribution of the pore volume of different permeable for liquids covering material and transporting liquid materials was determined using the method described in the article (Journal of Colloid and Interface Science (Journal of colloid and interface science, 1994, vol. 162, pp. 163-170). The used method is based on measurements of the amount of liquid that can be released from the porous material ("the selection mode") at a certain pressure, and the results of the measurements are presented as a curve on the graph where the curve illustrates the total pore volume for a given pore radius.
The measurements of the measuring liquid using n-hexadecane (purity 99%) from the company Sigma H-0255. Measurements were performed on round specimens with an area of 15.9 cm2. The sample was placed in a cell and feed the fluid for testing. As the membrane used a 0.22 μm Millipore (catalog number GSWP 09000). To make it possible to measure the remaining liquid, the sample was weighed before the test and immediately after its completion.
The equilibrium velocity, i.e. the velocity at which the change in mass for the selected pore radius was reduced to negligible significance was set at 5 mg/min, and the measurement time, in tech�tion of which recorded the change in mass, was 30 seconds.
The measurements were carried out at pressures corresponding to the following pore radii [µm]: 400, 350, 300, 250, 200, 150, 100, 75, 50, 25, 10, 5 and 2 (assuming that the surface tension of the liquid is 27.7 mn/m, and that the liquid completely wets the structure).
Fig. 6 is a full cumulative pore volume PVr(the index refers to the pore radius (r) for all voids, in which the corresponding pore radius smaller than the actual pore radius r, shown in the drawing. The total pore volume, at which the corresponding radius is in the range from the smaller pore radius to a larger radius then b can be calculated as follows:
It is assumed that the liquid entrained at high capillary pressures, for example, in the walls of the cells of the foam, is located in the voids with small corresponding to a radius of less than 2 μm. Larger pores are related to the volume of fluid which may be trapped in the voids between the walls of the cells of the foam. Foam with large cells and absorbs walls define a large total pore volume of less than 2 μm, the total pore volume is more than 5 mm3/mg, preferably more than 10 mm3/mg, as well as a significant volume of pores in the walls corresponding to the voids in the range from 10 μm to 50 μm, where the volume�m then is more than 20 mm 3/mg, preferably more than 40 mm3/mg. This foam is useful because it contains larger voids that can provide the best transfer fluid, and smaller voids that have better properties retention.
Example 7. Specific surface area by BET method
The specific surface area of the lyophilized material of example 5 was measured automatically gazoadsorbtsionnoi analyzer Tristar company Micromeritics. First, the samples were placed in vials and pre-heated in an inert atmosphere for 3 hours at 25°C in a programmable system degassing Smartprep company Micromeritics. After pre-processing the test tubes were placed in the analyzer. In all experiments used gaseous nitrogen. The specific surface area of the lyophilized samples of example 5 was calculated by BET method (table 5).
The lyophilized sample HTOP_A in table 4 (with a low content of charged groups) did not show desirable characteristics of foam material and appeared to be less stable in the wet state. Next, this sample is called "comparative sample III.
Table 5 presents the following samples:
Comparative samples I and II indicate the freeze-dried samples of comparative pulp cellulose I and II.
Sample B1: absorbent foam containing 0,92 mmol/g of charged groups; 10 minute machining
Sample C1: absorbent foam containing 1,02 mmol/g of charged groups; 10-minute machining
Sample D1: absorbent foam containing 1,38 mmol/g of charged groups; the 1-minute machining
Sample D2: absorbent foam containing 1,38 mmol/g of charged groups; 3-minute automatic processing
Sample D3: absorbent foam containing 1,38 mmol/g of charged groups; 10-minute machining
Sample D4: absorbent foam containing 1,38 mmol/g of charged groups; 15-minute machining
Specific surface area by BET method
|Sample||Specific surface area by BET method (m2/g)|
|Comparative sample I||15,9|
|Comparative sample II||21,7|
|Comparative sample III||9,6|
Measurement of the specific surface show that the specific surface area increases with the content of charged groups. In addition, the specific surface increases with the time of mechanical treatment. When the content of charged groups is reduced, it may be necessary to use a longer period of mechanical processing that may occur in the case of sample B1.
Example 8. Scanning electron microscopy
Scanning electron microscopy was used to study the structure of the comparative sample III and D3 in example 7. The sample was prepared, selecting first a small amount of freeze-dried homogenized TEMPO oxidized pulp of lyophilized sample. Then, on the surface of the samples sprayed a layer of gold ions, having an approximate thickness of 20 nm using ion spray JFC-1100E firm JEOL. After the step of spraying segments of the samples were placed in a scanning microscope JSM-820, JEOL company at an accelerating voltage of 20 kV. Digital photos of the samples was obtained using the slow scanning device Ozerova�ing Semafore SA20 firm JEOL and software Semafore 5.1.
Fig. 1a and 1b illustrate a fiber mesh sample D3 and comparative sample III, respectively. The increase is 370 - and 350-fold, respectively, and the markers represent the length of 100 mm.
Example 9. The stability of the absorbent porous foam
Determination of content of carbonyl groups with sodium chlorite
The oxidation of sodium chlorite was performed to determine the content of carbonyl groups in cellulose mass. Sodium chlorite oxidizes the carbonyl group in this slow reaction. The content of carbonyl groups was then calculated by the increase in the content of charged groups in comparison with the image, which is not oxidized by sodium chlorite. Weighed 0.05 g of sample was injected into a mixture containing 10 ml solution of 0.5 M CH3COOH, 5 ml of 0.5 M NaOH, 0.04 g of NaClO2and 85 ml of deionized water. The pH of the solution was 4.6. The pulp suspension was stirred during the reaction term (24 hours). After the reaction of the cellulose mass was washed with 200 ml of deionized water. The content of charged groups is then determined by the method of sorption of methylene blue, see example 2.
The recovery of the carbonyl groups tetrahydroborate sodium
Reduction of the oxidized pulp (TOP_D) was performed to reduce the content of carbonyl groups. For this purpose, 5 g of oxidized cellulose mass� suspended in water (solid content material of 8%) together with to 0.303 g of NaBH 4and 0.115 g of a 0.05 mm solution of NaOH. The suspension was poured in a plastic package and plastic package was placed in a water bath (60°C) for 2 hours. The reaction of the carbonyl group was restored to the hydroxyl group. After the reaction time the pulp mass was cooled by dilution with cold water, and then the sample was evaporated and washed with deionized water.
The foam stability was studied by preparing samples with different content of carbonyl groups.
Sample 1: sample described above D4.
Sample 2: same as sample D4, but the oxidized pulp treated tetrahydroborate sodium prior to mechanical processing (to reduce the number of carbonyl groups).
Sample 3 comparative sample I, mechanically processed within 120 minutes.
All three samples were placed in a beaker containing a large excess of water. Sample 1 containing carbonyl groups in an amount of 0.61 mmol/g of MFC, was restored to its original size and shape after initial shrinkage in the process of rapid absorption of water. Bonds formed in this sample, create a stable porous foam in the wet state. The size and shape of the specimen was also recovered after compression by 20% in height. This shows that the MFC fibrils are held together timeprofile links. In the case of sample 2, where the content of carbonyl groups is 0.14 mmol/g of MFC, the sample was returned to a gel state after wetting. During compression, the sample was split into several fragments. Sample 3 (0,03 mmol of carbonyl groups per gram cellulose) was completely dispersed in the wetting of the sample. This shows that in this sample there are no connection that protects fibrous mesh in the presence of water.
Thus, the results definitely show that the carbonyl groups present in the absorbent porous foam material according to the present invention, create interfibrillar covalent bonds, which are important for the maintenance of foam in the wet state. Previously it was proposed to use cross-linking reagents for binding the particles of microfiber material, but the absorbent material according to the present invention, cross-linking reagents are not required.
Example 10. Absorbent properties
Experiments on the absorption was carried out to assess the absorbent properties of the absorbent foams having a high content of charged groups (sample D4).
Comparative experiments were carried out with samples D HTOP, which was dried in the air instead of lyophilization (15-minute mechanical processing).
The experiments were performed in deionized water and a solution of 1.0 mA�S.% NaCl, respectively. First, we measured the dry mass of the sample. At each measurement the sample was placed in a beaker at time zero and left to soak in for 1 minute, 3 minutes, 5 minutes and 10 minutes, respectively.
Then the clock stopped, and the sample was removed from solution, free water was allowed to drain, and measured the mass. Then the sample was placed in a beaker and again included a clock.
Tests are also conducted with a sample of D4 during compression of the material, at least 30 times compared to its original height.
Samples of HTOP, which was dried in the air, poured on the surface of the plastic cap, and left to dry at room temperature for several days. There was obtained thin films with various amounts of fibers present, depending on the level of oxidation and mechanical processing.
The air-dried material is then called in this document the term "air-dried homogenisierung TEMPO oxidized pulp" (AD-HTOP).
In table 6 absorb liquid in parentheses. Presented in the table values denote the ratio of the mass of absorbed liquid and the dry weight of the sample.
Absorbent properties in yy
|Sample||1 min||3 min||5 min||10 min|
|D4 (1% NaCI)||121||148||153||141|
|D4_ (1% NaCI)||54,2||70,4||72,2||75,9|
|AD_HTOP (1% NaCI)||2,0||2,4||2,4||2,6|
Experiments on the absorption showed large differences in speed and ability absorbed between foam and a thin film obtained by air drying clicks�scow HTOP.
The air-dried film does not absorb large amounts of fluid either in brine or in water, and after 90 minutes was not detected any significant increase in absorption. For samples of the foam (D4) the initial absorption rate was very high due to the open and porous structure of the material. Absorption after 10 minutes was 182 g/g, which approximately coincides with theoretical value of absorption, which is calculated as the volume of voids in the dried material.
High values of absorption were obtained even after 1 minute, 3 minutes and 5 minutes, respectively. Absorption rate was high even when the compression of the material. The speed and capacity of absorption were also high when using the salt solution, but not as high as for deionized water.
Example 11. Bulk when wet
To evaluate the behavior under external load, bulk density in the wet state was measured for the two absorbent foams according to the present invention (B2 and D4), when they were subjected to various external loads. The liquid for the test consisted of deionized water. The content of solid material in the samples homogenized TEMPO oxidized pulp before lyophilization was 0.6%.
Used cylinder with internal�Enni 5 cm in diameter, having a bottom, made of permeable for liquids metal mesh. The grid needs to maintain stability and to withstand loads equal to 20 kPa. Also used a meter thick, are able to apply load to the specimen during the measurement of its thickness. Easy flat acrylic plate of the same diameter as the inner diameter of the cylinder was placed on top of a metal grid. This acrylic plate further herein termed "lid". The weight of the cover must be correctly identified, while the cover remains dry. Measuring the thickness was trioval 0 mm inside the cylinder on the cover surface, placed on a metal grid inside the cylinder.
A sample of 5 cm in diameter were weighed and its mass recorded. Then the sample was placed on the cylinder. The lid was placed on the surface of the sample. Joint load measuring the thickness and the cover was 0.7 kPa. This configuration remained steady for 2 minutes. After that, the thickness T1 was measured and recorded. Bulk density in the dry state can be calculated as follows:
Bulk density in the dry state = T1 [cm]•the Size of the sample [cm2]/Weight of dry sample [g]
In a clean beaker with an inner diameter of 10.4 cm was placed 80 ml deminsional water. The cylinder with the sample is carefully placed in a laboratory�atorny the glass.
Preferably, the beaker was placed around the sample without moving the sample. The sample was allowed to absorb the liquid for 10 minutes under load only one cover (of 0.07 kPa). The beaker with the liquid was carefully removed and the sample was left for 2 minutes (without measurement). Then made a full load of 0.1 kPa and left the system on for 2 minutes.
Then they measured and recorded the thickness TW, and it was possible to calculate the volumetric mass of wet:
Bulk density in the wet state = TW [cm]•the Size of the sample [cm2]/Weight of dry sample [g]
The load exerted in the sequence according to table 7. For each new load time conditioning before measurement of the thickness was 2 minutes.
If the sample area was not the same as the area of the cylinder 5 cm in diameter, attached load is changed in accordance with the actual size of the sample. The sample that was not pre-fabricated in a layer, could pass the test in the case of uniform distribution of the sample on a metal mesh.
Table 7 illustrates the volumetric mass of wet two samples of foam according to the present invention, i.e., B2 (similar to the above sample B1, but the machining time was 15 minutes) and D4, in comparison with comparative sample II(i.e. lyophilized comparative cellulose mass II).
Bulk density in the wet state (refer3/g)
|Load (kPa)||Comparative sample II||B2||D4|
Example 12. The ability of free swelling (FSC)
The ability of free swelling was measured in a standard test EDANA 440.1-99, where the duration of stage dive, which is 10 minutes, reduced to 2 minutes. The ability of free swelling was also measured after 1 minute and 5 minutes, respectively.
For these measurements used the same samples that were used in the test bulk density in the wet state.
The ability of free swelling (g/g)
|Time||Comparative sample II||B2||D4|
The results of table 8 are illustrated in Fig. 3.
Example 13. Holding capacity by centrifugation (CRC)
Holding ability�ness by centrifugation was measured in a standard test EDANA 441.1-99.
For these measurements used the same samples that were used in the test bulk density in the wet state.
Holding capacity by centrifugation (yoy)
|Time||Comparative sample II||B2||D4|
The results of table 9 are illustrated in Fig. 4.
Manufacturing a composite material according to the present invention
Oxidation and mechanical treatment of pulp was carried out according to the explanations in the examples 1-4. Then gelled microfiber cellulose (HTOP) was mixed with pulp lots of different types.
Mixer from the company IKA used for mixing the material HTOP and cellulose fibers.
For each sample use a fixed amount of material HTOP, so the number of fibers was determined by the ratio of the fibers and material HTOP. The stirring was continued to obtain a homogeneous suspension.
The ratio of fibers and material for HTOP pulp of various types in the manufacture of a composite material
|Fiber type||The ratio of fiber and HTOP (g/g)|
CRO�e, for comparison produced samples containing only absorbent material and fibers (samples containing only fibre, had the same weight in the dry state, as samples containing 4 g fiber / 1 g HTOP). Suspension liofilizirovanny as in example 5 (for each sample was used 20 g of wet suspensions).
Liofilizirovanny suspension in which the solid content of the material ranged from 0.6 to 5.0%. 20 g of the suspension were placed in glass beakers 100 ml Samples were frozen with liquid nitrogen and placed in a freeze dryer Hetosicc 2.5 CD from the company Heto, as long as the material did not recognize dry (about 48 hours). The pressure in the lyophilization process was approximately 0.3 mbar (30 PA), and the temperature of the condenser was -55°C. After lyophilization, the samples were placed in plastic bags and stored at room temperature.
Characteristics of the composite material
Example 14. Scanning electron microscopy
In accordance with example 8, scanning electron microscopy was used to study the structure of the composite material. Fig. 1c illustrates obtained by the method SEM structure of composite material comprising fibers CTMP (5.7 g CTMP/g absorbent material).
Example 15. Bulk when wet
Bulk density in wet state�research Institute in the case of composite materials (plus samples, containing 0% and 100% of the fibers) was measured in accordance with example 11, except that a physiological solution (0.9 wt.% NaCl) was used as the liquid for the test instead of deionized water. The load was not significantly different compared with example 11 as a consequence of the square samples used, and the load used for composite materials, are presented below.
Volumetric mass of wet composite material containing different amounts of (i) unbleached coniferous sulfonated pulp (SKP), (ii) chemicomechanical pulp (CTMP), and (iii) high temperature chemicomechanical pulp (HTCTMP), pollastri�of use in Fig. 2b. In addition, the measurements were conducted for a clean absorbent material, as well as for pure pulp of each type. The dotted lines in Fig. 2b represent theoretical bulk density in the wet state, which is expected for a composite material containing cellulose mass of each type.
Example 16. Holding capacity by centrifugation composite materials
Test the holding capacity by centrifugation was performed as in example 13. The test samples consisted of samples containing only fibre, only the absorbent material, and composite materials containing different amounts and different types of fibers. Measured CRC values are then used to calculate bad crc2 (see below formula). Bad crc2 is a holding capacity absorbent material, if improved the ability of the composite material is entirely attributable to the absorbent material. This assumption is reasonable due to the restrictions of the fibres on the retention of large amounts of fluid. In this formula you can see that the subtracted contribution to CRC, is due only to the fibers, and also subtracted the mass of fibers. Thus, bad crc2 can be defined as a CRC-absorbing material when it is used together with the fibers in Ko�positon material according to the present invention.
As illustrated in Fig. 4b, at low concentrations of coniferous fibres unbleached sulfated pulp (SKP) was a preferred type of pulp, while the addition of mechanically processed pulp (CTMP or HTCTMP) was preferred at high concentrations of fibers. The increased stiffness of the pulp and CTMP fibers and HTCTMP was favourable for the creation of sustainable grids at high concentrations of fibers. The highest possible value of CRC was obtained at high concentrations of cellulose fibres, indicating a better preservation of the porous structure (fewer destruction of the structure) at high concentrations of fibers.
Although the present invention is illustrated and described in detail in the drawings and the above description, the drawings and description should be considered illustrative or exemplary and not restrictive; the present invention is not limited to the described variants of its implementation. Other variations of the described embodiments can understand and exercise specialists in the art in the practical use of the claimed invention as a result of studying these drawings, descriptions and p�rageboy of the claims. For example, the present invention is not limited to use of a particular type of pulp.
In addition, the present invention is not limited to a specific method of administration of a plurality of charged groups in microfibrous cellulose, and may be any suitable method.
1. Absorbent article containing a lyophilized composite material; and specified lyophilized composite material contains cellulose mass and absorbent material, wherein said absorbent material comprises microfibrous cellulose in the form of an absorbent porous foam material; and in said microfibrous cellulose (MFC) the content of carboxylate groups ranges from 0.5 to 2.2 mmol/g of MFC.
2. Absorbent article according to claim 1, wherein said composite material contains at least 5 wt.% an absorbent material.
3. Absorbent article according to claim 2, wherein said composite material contains from 10 to 50 wt.% an absorbent material.
4. Absorbent article according to any one of claims. 1-3, in which the specified pulp is chemicomechanical cellulose pulp (CTMP).
5. Absorbent article according to any one of claims. 1-3, in which the content of carboxylate groups in said microfibrous cellulose is from 0.8 to 1.8 mmol/g of MFC.
6. Vpityvaya� a product according to any one of claims. 1-3, in which the content of carbonyl groups in said microfibrous cellulose is at least 0.2 mmol/g of MFC, preferably at least 0.5 mmol/g of MFC.
7. Absorbent article according to any one of claims. 1-3, in which the specified absorbent material specific surface area by BET method is at least 24 m2/g, preferably at least 30 m2/g.
8. Absorbent article according to any one of claims. 1-3, in which the specified absorbent material volume weight in the wet state is at least 10 cm3/g at 5 kPa, preferably at least 15 cm3/g at 5 kPa.
9. Absorbent article according to any one of claims. 1-3, in which the specified absorbent material meaning the ability of free swelling (FSC) is at least 45 g/g.
10. Absorbent article according to any one of claims. 1-3, in which the specified absorbent material holding capacity by centrifugation (CRC), defined in test the holding capacity by centrifugation, is at least 8 g/g, preferably at least 12 g/g.
11. Absorbent article according to any one of claims. 1-3, wherein said composite material can be obtained:
(a) oxidizing a first cellulosic mass to obtain a content of carboxylate groups of from 0.5 to 2.2 mmol/g cellulose� mass;
(b) crushing the specified first pulp mixture into microfibrous cellulose;
(c) mixing microfibrous cellulose after stage b) with a second cellulose mass;
(d) lyophilizer specified blend of microfibrous cellulose and the second pulp.
12. Absorbent article according to claim 11, in which the specified microfibrous cellulose and the specified second pulp weight after stage c) is mixed in the wet state.
13. Absorbent article according to claim 10, wherein said second pulp is chemicomechanical pulp mass.
14. Absorbent article according to claim 12 or 13, in which the specified stage of oxidation (a) is carried out in the presence of (2,2,6,6-tetramethylpiperidine-1-yl)Axela (TEMPO).
15. Absorbent article according to any one of claims. 1-3, contains permeable to liquids top sheet, bottom sheet and an absorbent mass, nested between said permeable to liquids top sheet and the bottom sheet where the specified composite material is present in said absorbent mass.
16. Absorbent article according to claim 10, in which the specified absorbent mass or at least one layer contains a specified fraction of the composite material mixed with a second absorbent material.
17. The use of lyophilized composite material, soderzhashchayasya weight and the absorbent material, wherein said absorbent material comprises microfibrous cellulose in the form of an absorbent porous foam material; in said microfibrous cellulose (MFC) the content of carboxylate groups ranges from 0.5 to 2.2 mmol/g of MFC in the absorbent structure.
SUBSTANCE: what is described is a mesh bioactive wound coating with its base containing disintegrated bacterial cellulose comprising antimicrobial and antioxidant ingredients: silver-modified montmorillonite and fellerenol aiming at optimising the course of the wound process, preventing the development and suppression of a wound infection. The mesh bioactive wound coating is used for treating gunshot wounds, severe mechanical injuries, uninfected and infected wounds, including septic and persistent wounds, granulating wounds following deep thermal, chemical and radiation burns, for conducting the integrated treatment of trophic ulcers and bedsores in hospital, out-patient and field settings.
EFFECT: mesh bioactive wound coating is non-toxic; it causes no local irritant and skin re-absorption action, possesses elasticity, a high degree of wound modelling; it is not fragmented that facilitates a wound care.
5 dwg, 2 tbl, 3 ex
SUBSTANCE: invention relates to biotechnology and medicine, and specifically to a method of producing film-type and composite materials based on chitosan and polylactide, which are biodegradable, biocompatible and hypoallergenic. Described is a method of producing composite biodegradable materials based on chitosan and polylactide, which includes preparing polysaccharide and polylactide solutions using a mixed solvent, wherein the chitosan solution is mixed with 10-50% polylactide solution with respect to the mass of chitosan while stirring continuously. The obtained mixture is subjected to ultrasonic treatment until a block-copolymer of chitosan and polylactide is obtained. Disclosed materials can be used in articles for biomedical purposes, including osteosynthesis materials and prolonged action medicinal drug carriers.
EFFECT: obtained materials are used for osteosynthesis based on natural and synthetic polymers, decomposition products of which prevent the development of toxic, inflammatory and allergic reactions in tissue owing to use of a chitosan biopolymer.
2 cl, 1 tbl, 5 ex
SUBSTANCE: invention refers to medicine. What is described is a method for producing a therapeutic tissue involving producing a polymer base containing alginic acid salt, administering an active substance in a therapeutically effective amount, agitating the mixture in a slow-speed mixer, applying the prepared composition on a textile material containing at least 50% cellulose fibres, while the composition of the polymer with the active substance is applied on the textile material through a mesh template at a cell size of 200 to 450 mcm to generate a continuous polymer layer on the face surface of the textile material not penetrating to the inner side.
EFFECT: method enables extending the range of therapeutic agents and biologically active additives, enabling variation of their concentration that causes their concentration in treating various diseases, enables fast transformation of the technological process and its cost-effectiveness.
28 cl, 23 ex
SUBSTANCE: invention refers to medicine, more specifically to a biodegradable absorbent polymer produced from a composition with nitrogen-containing heterocyclic monomer, polymerized acryl or methacryl, a non-organic excipients and an allyl compound of cellulose.
EFFECT: biodegradable absorbent polymer has excellent biodegradability and high absorbing capacity.
11 cl, 3 tbl, 2 dwg, 5 ex
SUBSTANCE: material consists of several layers: an inner layer is made from chitosan nanofibres/superfine fibres, and an outside layer are used as an electrical forming substrate and exercise the protective function. The chitosan layer is made from herbal or mixed herbal and animal chitosan and can contain antibiotic. The multilayer material can contain at least one more layer of biopolymer nanofibres/superfine fibres electroformed of cellulose diacetate or gelatin. The three-layer material with the chitosan layer of the nanofibres/superfine fibres is applicable for local wound and burn healing.
EFFECT: material resistance to mechanical stress.
15 cl, 4 dwg, 8 ex
SUBSTANCE: dressing represents a knitted mesh fabric coated with a composition of a biocompatible film-forming polymer of polyvinyl pyrrylidone and drug preparations: iodine, novociane, carboxymethyl cellulose sodium salt, of the following formulation (mg/cm2): iodine 0.0282±20%; polyvinyl pyrrylidone (Mr 20000) 1.2±20%; novociane 0.426±20%; carboxymethyl cellulose sodium salt 1.6-1.9.
EFFECT: using the wipe provides antimicrobial, antiseptic, disinfecting, antifungal and antiprotozoal action ensured by the fact that a polyvinyl pyrrylidone matrix retains iodine in the wipe and promotes its release on the skin.
SUBSTANCE: what is described is a coating in the form of a film which contains the following ingredients, wt %: low-molecular edible chitosan 5.3-5.7, glycerol 2.2-2.8, ceruloplasmin 0.06-0.08, L-asparaginic acid 0.04-0.06, a solvent with pH 5-7 - the rest. What is described is a method for preparing the coating consisting in the fact that a chitosan weigh is diluted in the solvent at 1000 mg of the weigh to 15 ml of the solvent, mixed and placed in a thermostat at a temperature of 37-42°C for 1-2 hours. The mixture is added with ceruloplasmin diluted in the solvent at 1:10 to form a homogenous hydrogel. L-asparaginic acid is diluted in the solvent pre-heated to 37-40°C and added to the mixture to provide pH of the mixture 5-7. A plasticising agent in the form of glycerol is added in the amount of 2.2-2.8% of total volume of the prepared biomass The prepared biomass is placed into containers to form a uniform layer of the coating 3-5 mm high and to form a film by drying the biomass for 18-24 hours in the thermostat at a temperature of 37-40°C.
EFFECT: wound coating provides the highest clinical effect.
6 cl, 6 dwg, 2 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to chemical-pharmaceutical industry and medical equipment and may be used in preparing multifunctional biological active structures for the fixation of dressings and objects. The fixation device consists of a paper carrier made of cellulose and viscous fibres impregnated with a special preparation, dried; with its one side of the prepared carrier coated with an adhesive and with its other side coated with a primer and an adhesive.
EFFECT: improved drape effect, enhancement, easier and faster usage.
6 cl, 1 tbl, 2 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to medicine. What is described is a superabsorbent polymer composite containing superabsorbent polymers and cellulose nanofibrils having a diameter of 100 nm or less. The composite may be presented in the form of either particles, or foam. There are also described methods for preparing the composite and absorbent products containing the superabsorbent polymer composite.
EFFECT: cellulose nanofibrils improve the gel strength of the superabsorbent polymer.
23 cl, 6 dwg, 6 ex
SUBSTANCE: invention refers to medicine, particularly to surgery, burn and radiation therapy. A dressing contains rayon fabric which at the first stage of carbon cloth production is exposed to ionising radiation of a high-speed electron bunch in cathode-ray current (1-3) mca and power (0.5-0.7) MeV when transported through an electron accelerator exposure chamber at rate (1-4) m/min; the produced carbon cloth is characterised by density 1.3-1.4 g/cm3; surface density 2.5-3.5 m2/g; carbon content 99.6-99.9 wt %; ash content 0.1-0.4 wt %; chlorhexidine absorption 0.6-0.7 g/g if continuously coating the wound surface for 4 days.
EFFECT: dressing is characterised by high sorption dynamics, does not stick to the damaged skin, and does not scar after burns, cleans the wound surface so that reduces a time for wound preparation for closure in 1,5-2 times due to its high mechanical strength and chemical resistance of the carbon cloth after graphitisation at 2400°C; the dressings are re-useable.
SUBSTANCE: what is described is an antiseptic sorption material having the anti-inflammatory, wound-healing, absorbent, astringent and antiseptic action representing a microfiber matrix with a disperse adsorbent attached to its fibres and containing highly porous alumina hydrate particles and zinc oxide particles. A method for making the same and a based dressing are also described.
EFFECT: material is applicable for making wound dressings having additional functional properties and maintaining the absorbing properties of the material absorbing the wound discharge, inhibiting bacterial growth inside the dressing and preventing the wound re-infection.
15 cl, 4 dwg, 2 tbl, 3 ex
FIELD: process engineering.
SUBSTANCE: invention relates to disposable absorbing articles and their production. Proposed method comprises making of side panel web with lengthwise direction, separation of side panel material strip of maximum size. Embossed image is applied on main element material web before securing of strip, said image being provided with marking band of from foot tape, rear foot tape band and waist band tape. Note here that said band has the section of marking band of front foot tape, section of band of rear foot tape and section of waist tape band. Proposed method comprises attachment of band to main element material web to make the article assembly web. Note here that main element material web has machine direction, web material being cut for making of a separate article.
EFFECT: decreased amount of wastes.
20 cl, 6 dwg
SUBSTANCE: method involves application of a dressing on the periodontal tissues. Before the application of the dressing, the periodontal tissues are irrigated with Dentos solution for more than once. The dressing is prepared by adding zinc oxide power and zinc sulphate to Dentos and mixing them to pasty consistency. The solid dental tissues are coated with the polymer film from the vestibular and oral surfaces to a cutting edge. The periodontal tissues and the solid dental tissues coated with the polymer film are coated with the dressing.
EFFECT: method provides the anti-inflammatory, hardening, haemostatic capillary-reinforcing, immunomodulatory and adaptogenic effects; it enables maintaining the active substance concentration in the periodontal tissues, removing the dressing from the solid dental tissues, preventing colouring them and providing the Dentos exposure on the restoration components.
SUBSTANCE: invention relates to medical equipment, namely to wound bandages. Wound bandage for wound treatment from medium to high exudation contains carrying layer and absorbing pillow, with absorbing pillow including first absorbing layer, which contains first absorbing material, and different from first layer second absorbing layer, which contains different from first material second absorbing material, with first layer being held at a distance from second layer by at least one third layer, and third layer contains at least one antimicrobial preparation, characterised by the fact that second absorbing material contains fibres, which possess super-high absorption ability, and absorbing pillow additionally contains contacting with wound layer, which is in direct contact with first layer, and contacting with wound layer represents polymer net or perforated polymer film, and antimicrobial means represents elementary silver, silver oxide, silver complex, or silver salt, or their mixtures, and fibres which have super-high absorption ability are obtained from salts of polyacrylic acids or polyacrylates.
EFFECT: application of invention makes it possible to reduce risk of sticking to wound and simultaneously counteract maceration, without loading wound to be treated with excessive biologically active substances.
8 cl, 3 dwg
FIELD: personal use articles.
SUBSTANCE: disposable diaper contains a back and a front parts, an absorbing element, a belt flap and a hydrophilous sheets set. The hydrophilous sheets set includes an inner hydrophilous sheet and an outer hydrophilous sheet; the inner hydrophilous sheet and the outer hydrophilous sheet are in the belt zone containing a zone overlapping the belt flap edge and the absorbing element end. The belt flap having an outer hydrophilous sheet and an inner hydrophilous sheet additionally contains a belt elastic element fixed in the flap in a condition wherein the belt elastic element is stretched in a cross direction of the disposable diaper so that the flap forms frills. The outer hydrophilous sheet has higher liquid absorbing capacity than the inner hydrophilous sheet and contains two outer hydrophilous sheets where the belt elastic elements are positioned between the said two outer hydrophilous sheets; the outer hydrophilous sheet passes from the belt flap edge beyond the absorbing element end and ends over the absorbing element.
EFFECT: sweat absorbing capacity enhancement thus preventing appearance of eczema, sweat fever, contact dermatitis etc.
7 cl, 13 dwg
SUBSTANCE: invention refers to an orthopaedic product and an orthopaedic pad, particularly an amputation stump pad, a contact pad, a prosthesis cover, an orthesis cover, a prosthesis collar, a shoe sole or orthopaedic socks, i.e. polymer materials used in direct skin contact. The polymer material is applicable for direct skin contact and contains a fine-distributed silver as an antibacterial agent and is additionally provided with fine-dispersed particles of other metal. The metals of the group containing aluminium or aluminium alloy, magnesium, bronze, titanium and/or platinum are applicable.
EFFECT: invention enables concealing the discoloration when using the orthopaedic pad on the skin, and hence when using the orthopaedic product provided with this pad, also including for masking the discoloration in the pigmented or coloured polymer materials applicable in air or skin contact.
7 cl, 1 tbl
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention relates to the field of pharmaceutics, namely represents a thixotropic preparation of a smearing consistence, which assists in healing wounds and improves characteristics of a postepithelially formed tissue.
EFFECT: invention describes a method of considerable increase of solubility of useful active substances in siloxane-matrix-forming preparations.
20 cl, 1 dwg, 4 ex, 9 tbl
SUBSTANCE: present invention relates to conveyor and method for producing absorbing article which uses such conveyor to selectively convey continuous canvas of different sizes. Conveyor selectively conveying continuous canvas having the first article size or continuous canvas having the second article size other than the first article size includes guiding mechanism made with possibility to change position of passing at least one of the first and the second side edge portions of canvas by means of contact interaction with at least side edge portion of canvas. There are two mechanisms: detection mechanism configured to detect position of canvas side edge portion passing and driving mechanism actuating guiding mechanism and mechanism of detection of equal distance in transversal direction being perpendicular to conveying direction of canvas of the first or the second canvas size. Detection mechanism and guiding mechanism are installed to be capable of simultaneous movement, detection mechanism is electrically connected with power drive which is part of guiding mechanism and detects passing of edge portion of canvas, and guiding mechanism corrects position of roller assembly which is part of guiding mechanism by means of power drive based on detection mechanism data.
EFFECT: invention is aimed to provide conveyor and method to produce absorbing article which are capable of selective conveying any of canvases for two or more sizes by simply changing position of side edge canvas portion passing without complex control.
10 cl, 8 dwg
FIELD: machine building.
SUBSTANCE: method to produce a disposable absorbing product with a variety of components is proposed and involves selection of the first material, suitable to be used as an external coating, manufacturing of a basic element including the external coating with the latter comprising the central zone of the external coating having the appearance of the external coating central zone, selection of the second material suitable to be used as an elastic panel, the second material is different from the first material, and manufacturing of the first elastic panel having the central zone of the first elastic panel. The method also implies the application of a printed graphic image on the first elastic panel on the central zone of the first elastic panel, and attachment of the first elastic panel to the basic element, choice and application of the print are made so that the central zone of the first elastic panel provides for appearance in essence similar to the appearance of the central zone of the external coating.
EFFECT: improved design.
20 cl, 5 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to light industry. In compliance with proposed process, outer clamp plate with front and rear waist edges. Elastomer material of front and rear article panels is attached to outer clamp plate. Front and rear panel material comprises laminar elastomer film. Outer clamp plate section is removed to make some spaced apart holes. Front panel elastomer material defines its width. The latter extends through at least 50% of the shortest distance extending from front waist edge to every hole. Rear panel elastomer material defines its width. The latter extends through at least 50% of the shortest distance extending from rear waist edge to every hole.
EFFECT: perfected method.
17 cl, 18 dwg
FIELD: medical engineering.
SUBSTANCE: device has foam tampon to be introduced into a wound area and material for covering the wound and sealing the foam tampon in the wound area. The foam tampon communicates to vacuum source via flowing medium to help draining the flowing medium. The foam tampon is impregnated with basic fibroblast growth factor and antimicrobial factor.
EFFECT: accelerated wound healing.
9 cl, 1 dwg