Porous pvdf film with high wear resistance, method of its production, as well as method of its rinsing and method of filtration using said film

FIELD: process engineering.

SUBSTANCE: this invention relates to porous films used as filtration membranes. Proposed film comprise poly(vinylidene fluoride) as the main component and polyethylene glycol as hydrophilic component. Degree of crystallinity of poly(vinylidene fluoride) polymer makes 50% or higher, but not exceeds 90%, while product of degree of crystallinity of poly(vinylidene fluoride) polymer by specific area of film surface makes 300 (%·m2/g) or higher, but not exceeds 2000 (%·m2/g). Porous film is produced by extruding film-forming solution from injection orifice. Said solution comprises hydrophobic and hydrophilic components and common solvent. Film-forming solution is hardened.

EFFECT: improved water permeability and resistance to effects caused by porous poly(vinylidene fluoride) film reagents.

12 cl, 1 tbl, 11 ex

 

CROSS-REFERENCE

The technical FIELD TO WHICH the INVENTION RELATES

The present invention relates to a porous PVDF (polyvinylidene fluoride) film, which has excellent permeability and resistance to chemical reagents, the method of production, as well as to the method of washing and to a method of filtering.

Filtration processes are widely used in such industries as manufacturing sterilized water, ultrapure water or drinking water, and air purification. In addition, in recent years, the range of applications of such filtration processes has expanded to include areas such as secondary or tertiary treatment of domestic wastewater or industrial wastewater stations for wastewater, and process water with high turbidity, such as the separation of solid particles from fluids in septic tanks.

Used for such filtration processes filter materials consist of membrane modules, consisting of a set of membranes of hollow fibers, in which the polymers with excellent ability to process form a hollow tube, or flat membranes, in which the polymers form a structure in the form of layers. However, in the case of the use of such membrane modules for water treatment and she is such the surface of the membrane becomes clogged in suspension of solid particles, detachable during filtration, thus causing a problem of lowering the ability of the membrane module to pass water.

For example, if the membrane module of this type in the septic tank for separating solid particles from liquids clogging of the membrane surface occurs, as described above, due to filtering and, because it causes a significant decrease in the ability of the membrane module to pass water, usually after a predetermined period of time or after filtration of a predetermined amount of the suspension is necessary to periodically flush the membrane. In General, the clogging of the membranes of this type by reason of their occurrence is divided into physical blockage (obstruction)in which fine particles and the like accumulate on the surface or inside the membrane, and chemical contamination (pollution), in which the organic substance and the like accumulate on the surface or inside the membrane as a result of adsorption.

Processing by blowing air at which the membrane is shaken continuously or intermittently feeding the air to the source water during the filtering or cleaning of the filter by reverse flow, is used as an effective way to prevent physical clogging. On the other hand, Alenia accumulated organic matter and the like by means of decomposition of the chemical reagents in the form of oxidizing reagents, such as sodium hypochlorite, or bases, such as sodium hydroxide, is used as an effective way to eliminate chemical contamination. However, these chemicals not only decompose the accumulated organic matter, but also simultaneously and gradually destroy the polymer included in the composition of the membrane, and cause its degradation. Therefore, as the repetition of washing chemicals, layered membranes are destroyed and at the same time collapse the membrane of the hollow fibers, thereby making it difficult long-term use of the membrane module.

Recently, in order to prevent caused by such chemical reagents fracture membranes on sale at industrial scale has released a membrane consisting of such materials as inorganic substances or fluorinated polymers such as polytetrafluoroethylene (PTFE), which has an excellent resistance to chemical reagents. However, since such materials have a poor ability to process compared to traditional polymers, it has been difficult using such materials to produce effective for filtering membranes with different shape and diameter of the pores.

On the other hand, although PVDF (PVDF) polymers are used as polymer components of the porous films, because when Anenii they are among the fluorine-containing polymers have a better ability to process, such polymers have the disadvantage associated with low compared with other fluorine-containing polymers resistant to reason. Therefore, using PVDF polymer, it has been difficult to produce a porous film capable of withstanding long-term use, which is accompanied by washing base.

In addition, compared with those commonly used in the manufacture of porous films "wet" or "dry-wet" methods, polymers, as polysulfones, ethers of polysulfones, polyacrylonitrile or cellulose acetates, PVDF polymers have poor solubility in organic solvents. Therefore, when using PVDF polymer for manufacturing a porous film "dry-wet" method, it was difficult to achieve useful in practice, values of pore size, permeability and durability of the film.

Methods of making membranes of PVDF hollow fibers suitable for use as membranes for dialysis, are disclosed as examples of the porous films, for which use such PVDF polymers (see, for example, patent Japanese Patent Publication No. 1988180). However, since the membrane of PVDF hollow fibers made according to this method of obtaining, not only have low mechanical strength, and also have poor permeability, as stated in the description of Takovo is, they are unsuitable for use in applications that require high permeability and resistance to high pressure (resistance to wear).

To compensate for the disadvantage associated with such a low mechanical strength, have developed methods for producing films on a hollow substrate (see, for example, International Publication No. WO 2004/043579). However, in such composite films due to long-term repeated use predict the existence of separation of the interfaces between the substrate and the film.

In addition, to preserve the mechanical strength of the membranes of PVDF hollow fibers is disclosed a method of inclusion of fibers in the thickest part of the membrane of the hollow fibers (see, for example, patent application Japanese Patent Application Laid-open No. 2005-270845). However, as predicted, that with this method it is difficult accurately to include fiber in the thickest part of the membrane of the hollow fibers and the output fibers on the surface of the membrane leads to defects in the membrane, this method is unsuitable for applications such as filtration of drinking water, which requires a high degree of filtering.

Moreover, it is disclosed the production of a porous membrane, which improve the mechanical strength reaches way caused by the temperature change of the phase section the population (see, for example, International patent Publication No. WO 2003/031088). The porous film obtained according to this method of manufacture, has a high degree of crystallinity and a high strength and at the same time when processing the hood and like her its permeability can also achieve a high level. However, since forming the porous film, the main part consists of spherical crystals, has a large specific surface area and therefore has an extremely large surface area in contact with the liquid, the stability of the resulting porous film for washing alkaline chemicals, which is an extremely effective way in the case of applications that require high permeability is extremely low. Therefore, the resulting porous film may be subjected to washing chemicals for easy and efficient removal of impurities film and as a consequence long-term use of the membrane module while maintaining its high permeability is difficult.

BRIEF description of the INVENTION

In order to solve the above problems, the purpose of the present invention is to provide a porous PVDF film, which has a high permeable is thew, as well as high chemical resistance to washing chemicals and the like, it has been difficult to implement with traditional porous polymer films, and which can be used for a long period of time, how you can get it, and how to wash and method of filtration using it.

As the result of conducting extensive studies to solve the above problems, the authors of the present invention have focused on the degree of crystallinity of PVDF polymer, which is the main component part of the porous film of the polymer component, and the specific surface area of the porous film and found that a porous film with a specific structure, for which these parameters are within the prescribed ratio, has excellent permeability and resistance to chemical reagents compared to conventional polymeric films, and also that such a polymer film can be obtained easily and invariant, thus achieving the purpose of the present invention.

Namely, the present invention provides the following for PCT(1)-(14):

(1) a porous film comprising a polymer component containing the PVDF polymer as a main component thereof, where the degree Crist is lichnosti PVDF polymer is 50% or more, but does not exceed 90%, and the product of the degree of crystallinity of PVDF polymer on the surface area of the film is 300 (%·m2/g) or more but does not exceed 2000 (%·m2/g);

(2) a porous film described in paragraph (1), where the total content of crystals of β-type crystals of γ-type crystalline part of the PVDF polymer is 30% or less of the total content of the crystalline part of the PVDF polymer;

(3) the porous film described in paragraph (1) or p. (2), where the polyethylene glycol with srednevekovoi molecular weight of 20,000 or more but not exceeding 300000, is contained as the polymer component in an amount of 0.01 parts or more but not more than 3 parts per 100 parts of PVDF polymer;

(4) the porous film described in any of the PP (1)-(3), where, according to the measurement method19F NMR spectroscopy contents intramolecular irregular sequences in the PVDF polymer is 8.8% or more but not exceeding 30,0%;

(5) the porous film described in any of the PP (1)-(4), where the porous film has a film structure, characteristic of the membrane of the hollow fibers;

(6) the porous film described in any of percentage points (1)to(5), where the porous film has a film structure in which the basis of the polymer component forms a mesh grid with the audience in her pores, and the total thickness of the polymer component continuously or discontinuously otrastaet, at least, up to 1/5 of the thickness of the film from the edges of the upper and lower surfaces of the film with the highest density;

(7) a method of washing a porous film, which consists in contacting a porous film described in any of percentage points (1)to(6), with an alkaline solution;

(8) a method of filtration which consists in contacting a porous film described in any of percentage points (1)to(6), alternately at least once with an aqueous solution and an alkaline solution;

(9) a method of obtaining a porous film, which consists in obtaining a porous film containing PVDF polymer as a main component, the extrusion molding hole film-forming solution which contains at least a hydrophobic polymer component containing the PVDF polymer as a main component, a hydrophilic polymer component and the total for both hydrophobic and hydrophilic polymer components of the solvent, and curing the film-forming solution in a solution that contains water as a main component thereof, where the hydrophilic polymer component using polyethylene glycol with srednevekovoi molecular weight equal to 20000 or more, but no more than 150000;

(10) a method of obtaining a porous film described in paragraph 9, in which the PVDF polymer using PVDF polymer retained the e intramolecular irregular sequences in which according to the measurement method 19F NMR spectroscopy is 8.8% or more but not exceeding 30,0%;

(11) a method of obtaining a porous film described in paragraph (9) or p. (10), wherein the film-forming solution contains 20 wt.% or more but not more than 35 wt.% the hydrophobic polymer component and 8 wt.% or more but not more than 30 wt.% the hydrophilic polymer component;

(12) a method of obtaining a porous film described in any of p.p. (9)-(11), wherein the temperature of the solution to curing the film-forming solution (Tb°C)and the temperature of the film-forming solution (Td°C) and the cloud point of the film-forming solution (Tc°C) satisfy the relation Td+5≤Tb≤Td+30 and the ratio of Td≤Tc≤Tb;

(13) a method of obtaining a porous film described in any of p.p. (9)-(12), in which the injection hole is doctrate injection hole, and a porous film with the structure characteristic of the membrane of the hollow fibers, is produced by extrusion molding hole film-forming solution together with contributing to the formation of cavities reagent and its cure in the solution which contains water as a main component thereof; and

(14) a method of obtaining a porous film described in any of p.p. (9)-(13), wherein the film-forming solution as abwehrstelle contains, at least dimethylacetamide.

Since the porous film according to the porous film of the present invention has a high permeability and high resistance to chemical reagents, it can be used in contact with chemical reagents used for washing and other chemical reagents, and its ability to pass water, downward as a result of clogging of the surface of the film, you can easily restore. In addition, since the porous film according to the present invention is characterized by the ability to prevent the lowering of the film strength due to decay and destruction when handling the chemical reagents used for washing and other chemical reagents, it can be used for a long period of time. Moreover, since the porous film according to the present invention can be produced as easily and stably, it has excellent performance and efficiency.

Description of the DRAWINGS

In Fig. 1 shows a19F NMR spectrum of the porous film according to example 7 of the present invention;

Fig. 2 is an electron micrograph (magnification: h) surface with a higher density (outer surface) of the porous film according to example 7 of the present izopet the deposits; and

Fig. 3 is an electron micrograph (magnification: h)obtained for the area, located near the center of the thickest part of the porous film according to example 7 of the present invention.

DETAILED description of the INVENTION

The following description provides an explanation of embodiments of the present invention. In addition, the following implementation options are given to explain the present invention and the present invention is not limited solely to the exercise of such options, or rather the present invention can be implemented in various ways without deviating from the invention.

The porous film according to the present invention contains PVDF polymer as a polymeric component, which forms a film. In this document PVDF polymer refers to homopolymer of vinylidenefluoride or copolymer containing vinylidenefluoride, the mole fraction of 50% or more. From the point of view of better durability preferably PVDF polymer was a homopolymer. In the case when the PVDF polymer is a copolymer, you can appropriately choose a well-known monomer as another capable of copolymerization monomer, copolymerizable with monomer vinylidenefluoride, and despite the fact that this is not), is there any specific limitations, preferably, when used, for example, fluorine-containing monomer or a chlorine-containing monomer. In addition, although there are no particular restrictions on srednevekovoi molecular mass (Mw) PVDF polymer, it is desirable to $ 100000 or more but not exceeding 1000000, and more preferably, it is comprised of 150,000 or more but not exceeding 500000.

Porous PVDF film contains a polymer as a main component a polymer component. In this document "containing as a main component" refers to a content of 50 wt.% or more in the content of solids in the polymer component. In addition, despite the absence of specific limitations in this respect, preferably, when the porous film contains PVFD polymer as a main component a polymer component at a content of 80 wt.% or more but not more than 99.99 wt.%, and more preferably at a content of 90 wt.% or more but not more than 99 wt.%. On the other hand, the porous film may also contain other polymeric component. Although no specific limitations to this, it is preferable that the other polymer component was compatible with PVDF polymer, and it is desirable to use, for example, fluorine-containing polymer having a high Usto the strains to chemical reagents similar to the one which has the PVDF polymer. In addition, as another polymer component can also be used hydrophilic polymer in the form of polyethylene glycol, which will be described later.

Since this porous film of high resistance to chemical reagents combined with high permeability, the degree of crystallinity of PVDF polymer, which is part of the film is 50% or more but not exceeding 90%, and the product of degree of crystallinity on the specific surface area of the porous film is 300 (%·m2/g) or more but not exceeding 2000 (%·m2/g).

In this work, in the case when the degree of crystallinity of PVDF polymer is less than 50%, the rigidity of the film decreases and the polymer is deformed under pressure during filtration, thus making it unsuitable for filtration. I believe that the destruction of the PVDF polymer under the influence of chemical reagents starts in the amorphous part, which exhibits elasticity. Therefore, if the degree of crystallinity of PVDF polymer exceeds 90% and the amorphous portion is relatively thin, porous film as a whole becomes fragile and easily torn by the decomposition and degradation of the amorphous part of the under the influence used for washing chemicals and they podobnych the other hand, if the specific surface area of the porous film is excessively small, the permeability decreases, thereby making the porous film is not suitable for associated with filtration applications. On the contrary, in the case where the specific surface area of the porous film is excessively large, despite the increase in permeability, resistance to chemical reagents due to increased contact with chemical reagents surface area decreases. Based on these results for porous film with excellent permeability and resistance to chemical reagents required to work specific surface area of the film crystallinity was in the range specified above, 300 (%·m2/g) or more but not exceeding 2000 (%·m2/g), and preferably in the order of 300 (%·m2/g) or more but not exceeding 1500 (%·m2/g), and more preferably, it was 300 (%·m2/g) or more, but not exceeding 1000 (%·m2/g). In addition, despite the absence of specific restrictions in relation to this, it is desirable that the specific surface area of the porous film was 3.5 (m2/g) or more, but not exceeding 30 (m2/g), and more preferably it were 5.0 (m2/g) or more, but not offset the La 20 (m 2/g).

Moreover, to improve the resistance to chemical reagents and, in particular, improve the resistance of the reasons that trigger the destruction of the PVDF polymer, it is preferable that the total content of crystals of β-type crystals of γ-type crystalline part of the PVDF polymer, which is part of the polymer film was 30% or less, more preferably 25% or less, and more preferably to 20% or less of the total content of the crystalline part. In this paper, there are three known types of crystal structures of PVDF polymer, consisting of crystals of α-type, β-type and γ-type, and PVDF polymer with a degree of crystallinity of 50% or more but not exceeding 90% can contain them in their crystalline part. However, since the crystal structure of β-type and γ-type are unstable in thermodynamic relation, in the case where these structures are contained in the crystals in large quantities, suppose that the porous film has a part that is prone to chemical destruction near the interface between the crystalline part and an amorphous part under the influence of chemical reagents, thus stimulating trend of decreasing resistance to chemical reagents for porous film as a whole. In addition, n is despite the absence of specific restrictions in relation to this, preferred is lower, so close to 0%as possible, the content of the total amount of crystals of β-type crystals of γ-type. In addition, PVDF polymer may contain in its crystalline part or crystals of β-type, or crystals of γ-type.

In addition, preferably, the PVDF polymer contained irregular sequence in a certain amount. In this document an irregular sequence refers to the part in which unlike regular sequence of CF2groups are adjacent in the chain of the molecule instead of the normal (standard) sequence PVDF, consisting of regularly alternating CF2and CH2-groups, and the ratio of the amounts of such groups can be defined through measurement method19F NMR spectroscopy.

From the point of view of wear resistance and film strength preferably, according to the measurement method19F NMR spectroscopy the contents of the irregular sequences in molecules PVDF polymer was 8.8% or more but not exceeding 30,0%. At low concentrations of irregular sequences, namely in the case of PVDF polymer containing a regular sequence in chains of molecules PVDF in large quantities, the destruction during processing used for rinsing chemical p the agents has a tendency to rapid development. At high contents of irregular sequences, namely in the case of PVDF polymer containing random sequences in chains of molecules PVDF in large numbers, characteristic crystallinity of PVDF polymer decreases, causing a tendency to the formation of a porous film with a low resistance. More preferably, the content of intramolecular irregular sequences for PVDF polymer according to the measurement method19F NMR spectroscopy was 8.8% or more but not exceeding 30,0%, preferably was 9.0% or more but not exceeding 25%, and especially preferably, it is 10% or more but less than 20%.

In addition, it is preferable that the porous film contains a polyethylene glycol (also known as polyethylene oxide) with srednevekovoi molecular weight (Mw) of 20,000 or more but not exceeding 300000, in the polymer component at a content of 0.01 parts or more but not more than 3 parts per 100 parts of PVDF polymer. Owing to the presence in the polymeric film such glycol due to the fact that the hydrophilicity of the film surface increases, and on the film surface during its contact with the aqueous solution is easily formed layer of water molecules, the frequency of contacts between the polymer component, which is included in the composition of the porous film, and as a result is passed for washing chemicals, considered to be reduced due to the presence of a layer of water molecules, which is formed on the film surface, and consequently the resistance of the porous film to chemical reagents can be improved. In this work, if srednevekovaja molecular mass (Mw) of the polyethylene glycol is less than 20000, the trend towards increased leaching of polyethylene glycol of the film. On the contrary, if srednevekovaja molecular mass (Mw) glycol exceed 300,000, the porous main body, which forms a porous film, there is an area in which the polyethylene glycol is in the form of spheres, thus stimulating the tendency to reduce the strength of the porous body. On the other hand, if the content of polyethylene glycol is less than 0.01 parts, the formation of the water layer is usually difficult, whereas if the content of polyethylene glycol is more than 3 parts, the polyethylene glycol excessively attracts water molecules, which leads to a tendency to swelling of the film and decrease permeability.

Despite the absence of specific restrictions on the form contains a polyethylene glycol, and the fact that the molecules of polyethylene glycol can be obtained so that they were present only in the surface layer of the porous main body, for example, by means fo the formation of the coating or carrying out graft polymerization, from the point of view of facilitating the effect of increasing resistance to the effects of chemicals over a long period of time, it is preferable that at least part of the molecules of polyethylene glycol is included in the base porous body.

Although the effects of increasing resistance to chemical reagents shown without regard to the way in which the form contains a polyethylene glycol, in the case of application of polyethylene glycol on the surface layer of the porous core part through the formation of a coating, and the like when using film in water glycol washed away over time, whereas in the case of covalent binding of polyethylene glycol with a surface layer of the porous core part in the graft polymerization and similar binding sites damaged during the washing of the film used for washing chemicals. Thus, in each of these cases, the promoting effect of increasing resistance to the effects of chemicals over a long period of time usually difficult.

Preferably, the porous film had a film structure, characteristic of the membrane of the hollow fibers. In this document the hollow fibre membrane refers to a film having the form polgolla. Due to the formation of a porous film with typical membrane of the hollow fiber structure of the film surface film on a unit volume of the module can be increased in comparison with the flat films. In addition, in the case where the porous film has a characteristic of the membrane of the hollow fiber structure of the film, there is an advantage associated with the ability to effectively use for washing film techniques such as reverse washing, which removes sediment, causing the cleaning liquid to penetrate into the opposite direction to the filtration direction, or blowing air, which removes sediment by shaking of the film, introducing air bubbles into the module. The inner diameter of the membrane of the hollow fibers is typically 0.10 mm or more but not more than 5 mm, and its outer diameter is typically 0.15 mm or more but not exceeding 6 mm in Addition, from the viewpoint of achieving a suitable balance between strength and permeability to the membrane of the hollow fibers preferably, the ratio of the outer diameter to the inner diameter of the membrane of the hollow fiber was 1.3 or more but not more than 2.5.

In addition, it is preferable that the amount of time required for the destruction of the membrane of the hollow fibers when the COI is Tania's story of long-time strength during the filtration under pressure, when the time for the destruction of the membrane of the hollow fibers is determined at constantly existing installed the pressure difference between the inner and outer sides of the membrane from the edge of the outer surface of the membrane, the pressure difference of 0.4 MPa was 150 hours or more. In this research, fracture membrane imply the inability of the membrane of the hollow fibers to maintain a round or oval shape, and in the case of oval rings refers to the condition in which the ratio of the length of the long axis to the length of the short axis of the outer diameter of the membrane of the hollow fibers is increased above 1.5. When the time required for fracture is small, the membrane tends to easy destruction due to the repeated application of pressure during filtration or reverse washing. As a result of establishing the period of time required to fracture when the pressure difference of 0.4 MPa, 150 hours or more, the film of the present invention is able to adequately meet the operational life (product), considered as required for planning applications.

Moreover, it is preferable that the filtration volume of pure water per unit area of the surface of the membrane for the membrane of the hollow fibers, based on the area of the inner membrane surface of the hollow is elocon, with the passage of pure water at 25°C through the membrane of the hollow fibers at a pressure during filtration of 0.1 MPa was 500 (l/m2·h) or more. Pure water used in this phase is distilled water or water filtered through the membrane for ultrafiltration or membrane for reverse osmosis with a fractional molecular weight of 10,000 or less. In the case of small filtration volume of pure water the number of membrane modules required to process a set number for a fixed period of time increases, thereby leading to an increase in the space occupied by the filtration equipment. Although in order to avoid this, set number can be processed within a fixed period of time, setting a higher pressure during the filtration process, in this case along with the need to have a membrane module, which is capable of withstanding higher pressure rise necessary to implement filtering energy consumption, thereby reducing performance. From this point of view, it is preferable that the filtration volume of pure water was as large as possible, and more specifically, it is desirable that $ 700 (l/m2·h) or more, and more preferably, it is left 1000 (l/m 2·h) or more.

Moreover, it is preferable that the polymer film described above, had a film structure in which the basis of the polymer component formed would mesh grid with the audience in her pores, or, in other words, it is preferable that it had the structure of a porous film, in which the basis of the polymer component of the hollow fibers would have been stitched in the three-dimensional grid, and then there would be the basis of the polymer component.

In addition, it is preferable that the porous film had a structure in which the thickness of the polymeric component in which pores are formed, increased continuously or discontinuously, at least up to 1/5 of the thickness of the film, at least from the surface, having the highest density among the upper and lower surfaces of the film. Owing to this structure, the damage to the film as a whole can be prevented even when a part of the surface is destroyed by chemical reagents, since the thick part of the film has a thick base. In this work the surface with the highest density refers to the surface with pores of smaller diameter, are present per unit area of the surface among the upper and lower surfaces of the film, porous film, and in the present description, it is determined by way of erenia, used in examples which will be described later. The pore diameter of the surface with the greatest density at this stage is usually of 0.001 μm or more but not more than 0.5 μm, and thanks to the filtering side surface with a higher density of physical clogging of the inner part of the porous film can be prevented more effectively, while maintaining high permeability. In addition, the porous film with such a structure is particularly suitable for applications in which the porous film can be used repeatedly when washing in the physical sense or in the washing chemical reagents. From the viewpoint of more reliably filtered water with high as such it is preferable that the pore diameter of the surface with the highest density was of 0.001 μm or more but not exceeding 0.05 microns.

Although it is preferable, when the porous film as described above can be used for applications involving filtration of aqueous solutions, thanks to its excellent permeability and resistance to chemical reagents, it is desirable that it also can be used in applications that accompanies contact with chemical reagents. In particular, particularly preferably, such a porous film could use the AMB in applications, followed by contacting with the grounds for which the use of traditional PVDF porous films was limited. In this paper, the applications, followed by contacting with the bases involve the filtration of alkaline solutions, multiple filtering non-alkaline solutions at alkaline washing solution, and simply washing with an alkaline solution, but are not limited to specific them. In addition, under an alkaline solution implies a solution containing at least any alkaline substance, and in a more preferred aspect thereof, mean a solution in which the concentration of the alkaline substance is 0.001 wt.% or more but not more than 20 wt.%.

The following description provides an explanation of the method of manufacturing a polymer film according to the present invention.

Preferably, the polymer film of the present invention produced the so-called "wet" method for the films in which film-forming solution (spinning solution)comprising at least a hydrophobic polymer component containing the PVDF polymer as a main component thereof, a hydrophilic polymer component and the total for both hydrophobic polymer component and the hydrophilic polymer component p is storytell, was extrudible of injection holes, followed by curing in a solution containing water as a main component thereof, or the so-called "dry-wet" method for the films in which film-forming solution ekstragiruyut of injection holes, then providing free movement within the prescribed period. As it is implied in this document, the hydrophilic polymer component in the present invention is defined as a polymer component, for which the critical surface tension of the polymer (γc) at a temperature of 20°C is 50 (mn/m) or more, whereas the hydrophobic polymer component is defined as a polymer component, for which the surface tension (γc) polymer at a temperature of 20°C is less than 50 (mn/m).

In this method of manufacturing a hydrophobic polymer component to obtain a porous film containing PVDF polymer as a main component thereof, and the hydrophilic component in the form of a hydrophilic polymer component is first dissolved in a shared hydrophobic polymer component and the hydrophilic polymer component solvent to obtain a film-forming solution for the porous film. The polymer components to obtain a porous film used at this stage, the mod is ut to be either PVDF polymer itself, or one or more types of other polymers can be introduced into the mix to improve the properties of the film.

In the case of the introduction in a mixture with other polymers specific restrictions in relation to other polymers, provided that they are compatible with PVDF polymer, are absent. For example, if desired, to impart hydrophilicity of the film can be used hydrophilic polymer, or, if desired, to further increase the hydrophobicity you can use a hydrophobic polymer, and preferably, when using a polymer is a fluorinated polymer. With the introduction of a mixture with other polymers, preferably film-forming solution contained 80% or more, and preferably 90% or more, PVDF polymer of the total solids content of the polymer component.

When the method of receiving according to the present invention, as the hydrophilic polymer component included in the film-forming solution, using polyethylene glycol (also known as polyethylene oxide) with srednevekovoi molecular weight (Mw) of 20,000 or more but not exceeding 150000. Although the porous film can be produced even when using polyethylene glycol with srednevekovoi molecular weight of less than 25,000, it is usually difficult to achieve a suitable match for the relationship between crystallinity and Ude is Inoi surface area, envisaged by the present invention. In addition, in the case when srednevekovaja molecular weight exceeds 150000, it is usually difficult homogeneously dissolved in the spinning solution, the main component of the hydrophobic polymer component in the form of a PVDF polymer, which forms a porous film. From the viewpoint of obtaining a spinning solution with a better film-forming properties, it is preferable that srednevekovaja molecular weight of polyethylene glycol was 30000 or more but does not exceed 120000. From the viewpoint of obtaining a spinning solution with a better film-forming properties when saving with this appropriate balance between the degree of crystallinity and specific surface area, moreover, it is desirable that the proportion of glycol in the hydrophilic polymer component, based on the content of the hydrophilic polymer component in the form of solids, was 80% or more, more preferably 90% or more, and still more preferably 95% or more.

As described above, although in the method of manufacturing according to the present invention it is necessary to use at least one grade of polyethylene glycol as a hydrophilic polymer component, you can use a combination of two or more varieties of polyethylene is glycol or can be used in combination with other hydrophilic polymer components. In respect of other hydrophilic polymer components that can be used in combination with polyethylene glycol, there is no particular limitation, and examples thereof include polyvinylpyrrolidone and partially saponified polyvinyl alcohol.

Polyethylene, which is produced in the form of industrial product can be used by itself or as polyethylene glycol, which satisfies the requirements specified above, it is possible to use polyethylene, obtained by blending several kinds thereof. Moreover, you can also use a glycol derived from polyethylene glycol with a large srednevekovoi molecular weight, taken as source material, with the subsequent regulation through chemical or mechanical treatment thereof to a suitable srednevekovoi molecular weight.

Moreover, from the viewpoint of obtaining a film with the best resistance to chemical reagents, preferably PVDF polymer used to prepare the film-forming solution, contained in a number of irregular sequence, and, as described previously, it is desirable to use PVDF polymer, which according to the measurement method19F NMR spectroscopy contents intramolecular irregular sequence which is 8.8% or more, but does not exceed 30,0%.

Moreover, despite the absence of specific limitations of ratio in which mixed hydrophobic polymer component and the hydrophilic polymer component to obtain a film-forming solution, it is preferable that the content of the hydrophobic polymer component was 20 wt.% or more but not exceeding 35 wt.%, the content of the hydrophilic polymer was 8 wt.% or more but not more than 30 wt.%, and the balance represented the solvent, and more preferably, the content of the hydrophobic polymer component was 25 wt.% or more but not exceeding 35 wt.%, the content of the hydrophilic polymer component was 10 wt.% or more but not exceeding 25 wt.%, and the balance represented the solvent. Obtaining a porous film using the film-forming solution in this range of compositions of the mixture facilitates the regulation of residual polyethylene glycol to a set number, making it easier, in addition, obtaining a porous film with high strength, excellent resistance to chemicals and excellent permeability.

In addition, when the above-described method of manufacturing the solution temperature (Tb°C), located in the working tank and containing water as a main component is as such, in which utverjdayut film-forming solution in the course of obtaining the film, and the film-forming temperature of the solution (Td°C) must satisfy the relation Td+5≤Tb≤Td+30, and preferably, they and the cloud point (Tc°C) film-forming solution to satisfy the relation Td≤Tc≤Tb. Produce a film under such conditions, under which observed this relationship for a range of temperatures, allows to obtain a porous film with high permeability, and at the same time also leads to the possibility to adjust the remaining amount of the polyethylene glycol, which may need to be adjusted so that it was in the desired range, since the curing is complete when the increase rate of diffusion, causing solidification of the solution, at least part of the molecules of polyethylene glycol is included in the base porous body.

Moreover, in the aforementioned method of manufacturing as injection holes in obtaining films use doctrate injection hole and preferably, the film-forming solution was extrudible of dogtramadol injection holes together with contributing to the formation of cavities reagent to otvetit film-forming solution in the solution containing at what we as a main component thereof. The result can be easily made porous film with a characteristic of the membrane of the hollow fiber structure of the film. Without any specific limitations dogtramadol injection holes and contributing to the formation of cavities reagent used in this work, it is possible to use known doctrate injection hole and contributing to the formation of cavities reagent commonly used in this technical field.

Moreover, there are no particular restrictions on the total solvent used for film-forming solution, provided that it dissolves, both hydrophobic and hydrophilic polymer components, and a known solvent can suitably be selected and used. From the viewpoint of stability of film-forming solution preferably as a common solvent used at least one type of solvent selected from the group consisting of N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAC) and dimethyl sulfoxide (DMSO). From the point of view of ease of handling and high permeability especially desirable is dimethylacetamide. In addition, at least one General type of solvent selected from the above group, can also be used as the shift of the data with other solvent of the solvent. In this case, it is preferable to use a mixed solvent, for which it is desirable that the total content of solvent selected from the above group was 80 wt.% or more and more preferably 90 wt.% or more.

As a result of application of such methods of manufacturing the present invention can be easily and invariant to produce a porous film with excellent permeability and resistance to chemical reagents, as well as with excellent wear resistance, which is impossible to achieve for conventional porous films.

EXAMPLES

Although the following description provides a detailed explanation of the present invention by specifying examples thereof, the present invention is not limited to these examples.

For the following porous film using the following methods were used to define the degree of crystallinity of PVDF polymer, the determination of the specific surface area, determination of the total amount of crystals of β-type crystals of γ-type from the total amount of the crystalline part of the PVDF polymer, the determination of the content of polyethylene glycol per 100 parts by weight of PVDF polymer, the definition srednevekovoi molecular weight contained in the film of polyethylene glycol (PEG), is the definition of the contents of the irregular sequences in the PVDF polymer, thickness determination of the basis of the thick part of the surface with the highest density, definition srednevekovoi molecular weight PVDF polymer and the test for resistance to chemical reagents.

(1) determination of the degree of crystallinity of PVDF polymer

Measurements by the method of differential scanning calorimetry (DSC) was performed under the following conditions, using the device DSC2920, manufactured by TA Instruments Japan. The baseline for calculating the amount of the absorbed heat is conducted from 60°C to the temperature at which culminated melting (approximately 190°C), and the degree of crystallinity of PVDF was calculated, using as a quantitative assessment is required for melting the crystals of a quantity of heat is 104,7 (j/g).

Sample mass: approximately 5 mg

Cell for sample: aluminum Cup.

The heating rate: 5°C/min

Purge gas: helium.

The velocity of the gas flow: 20 ml/min

(2) Determination of specific surface area

Dried by the method of freeze drying the membrane of the hollow fibers cut to a length of 2 mm to obtain 1 g of the membrane with the subsequent determination of the specific surface area thereof according to the method of brunauer-Emmett-teller (BET)using the device SA3100, manufactured by Coulter Electronics, Ltd.

(3) Determination of the total content of crystals of β-type and cu the growth of γ-type crystalline part of the PVDF polymer

Measurement method19F NMR spectroscopy in the solid phase was carried out at the conditions specified below, using the device DSX400, manufactured by Bruker BioSpin AG.

Sample: 2.5 mm sample, rotating the magic angle (MAS).

Measurement mode: single pulse (pulse mode: zg0).

19F 90° pulse duration: MX.

Duplicate standby time: 4 C.

Speed under magic angle (MAS): 32000 Hz.

Measure temperature: room temperature (25°C).

Internal standard: C6F6(-163,6 ppm).

The total content of crystals of β-type crystals of γ-type was calculated using the following equation, based on the peak height (Hαsignal corresponding to the crystals of α-type appearing in the field -78,9 ppm, and the peak height (Hα+β+γsignal corresponding to the aggregate of all crystals of α-type, β-type and γ-type that appears when -93,5 ppm.

The content of crystals of β-type and γ-type (%) =

= {(Hα+β+γ- Nα)/(Hα+β+γ+ Hα)}×100

(4) Determination of the content of PEG in the porous film on 100 parts of PVDF polymer

Measurement method1H NMR spectroscopy for porous films was performed using d5-DMF (deuterated dimethylformamide as solvent and tetramethylsilane was as wew is unit standard (0 ppm), with the help of the device Lambda 400, manufactured by JEOL Ltd. as a system for carrying out measurements by NMR spectroscopy.

The content of polyethylene glycol was calculated using the following equation, based on the integral value of the signal related to the glycol produced in the region of about 3.6 ppm (IPEG) and the integral value of the signal related to the PVDF polymer produced in the region from about 2.3 to 2.4 and 2.9 to 3.2 ppm (IPVDFin the resulting spectra.

The content of polyethylene glycol (weight%)={44(IPEG/4)/60(IPVDF/2)}×100.

(5) Determination srednevekovoi molecular weight PEG in a porous film

0.1 g of the porous film was dissolved in 10 ml of acetone, followed by the introduction of this solution dropwise to the resultant deposition rates of the components of the film of polymer in 100 ml of water and separation of the remaining film of polyethylene glycol in aqueous solution. Further containing PEG solution was concentrated using an evaporator, followed by dissolving the following mobile phase to obtain a solution of polyethylene glycol. Using 200 ml of the resulting solution, a measurement was performed by the method of gel permeation chromatography (GPC) under the following conditions to determine srednevekovoi molecular weight (as a standard image is and PEG).

Device: HLC-8220GPC (company Tosoh Corp.).

Column: Shodex SB-803HQ.

Mobile phase: aqueous solution KH2PO4(0.02 mm) + Na2HPO4(0.02 mm), the rate is 0.7 ml/min

Detector: differential Refractometer.

(6) the Determination of the irregular sequences in PVDF polymer

Measurement method19F NMR spectroscopy for porous films was performed using d5-DMF as solvent and CFCl3as an internal standard (0 ppm), with the help of the device Lambda 400, manufactured by JEOL Ltd., as a system for carrying out measurements by NMR spectroscopy. The contents of the irregular sequences in the PVDF polymer was calculated by the following equation using the integral value of the signal related to regular sequences that occur in the area approximately from -92 to -97 ppm (Ir), and the integral value of the signal related to irregular sequences that occur in the area approximately from -114 to -117 ppm (Ii), in the resulting spectra.

The contents of the irregular sequences (%) =

= {Ii(Ir+ Ii)}×100

(7) determination of the thickness of the basics of the thick part of the surface with the highest density

Ten or more pores on both surfaces high the perfect method of freeze drying of porous films were recorded when observed increase in a separate area with an electron microscope, and pores in the resulting electron micrographs were approximatively circles with further consideration of the diameter determined from the average surface area such as the diameter of pores on the surface. The resulting diameter of pores on the surface of the porous film with pores smaller diameter, taken as a surface with a higher density, considered as the diameter of pores on the surface with the highest density. Cross-section of the dried method of freeze drying of porous films were examined in a similar way with increasing h and to confirm that the base thickness increases continuously or stepwise, were compared to the thickness of the basics about the side opposite the surface with the highest density in this area to 1/5 the thickness of the film.

(8) Determination srednevekovoi molecular weight PVDF polymer

Measurement using gel permeation chromatography (GPC) was performed using 50 ml of the sample, representing a solution of PVDF polymer in dimethylformamide (DMF) with a concentration of 1.0 mg/ml, with the following conditions to determine srednevekovoi molecular weight thereof (as PMMA).

Device: HLC-8220GPC (company Tosoh Corp.).

Column: Shodex KF-606M, KF-601.

Mobile phase: dimethylformamide (DMF), the rate is 0.6 ml/min

<> Detector: differential Refractometer.

(9) Test the resistance of the porous film to chemical reagents

The test of the stability of the porous films to chemical reagents was performed by immersing the porous membrane of the hollow fibers in a solution of a chemical reagent for a fixed period of time, measuring the elongation at which destruction occurs when the tensile testing tensile and calculating the coefficient of maintaining the ability to lengthen according to the following equation on the basis of the corresponding fracture tensile elongation before diving (SW) and the corresponding destruction of the tensile elongation after aging in the processing of chemical reagent when immersed in n days (En).

The retention capacity for elongation (%) =

= (En/EO)×100.

In this paper a chemical reagent used in the test of resistance to chemicals, consisted of an aqueous solution composed of a mixture containing sodium hydroxide at a concentration of 4 wt.% and sodium hypochlorite at an effective chlorine concentration of 0.5 wt.%, and a porous film was immersed at 25°C. in Addition, the determination of the elongation at tensile clamping was carried out at a distance of 50 mm and at a speed races is agenia, 100 mm/min

Example 1

27 wt.% PVDF polymer in the form of PVDF homopolymer with srednevekovoi molecular weight of 350,000 (KYNAR741, the company Arkema Co., Ltd.) and 15 wt.% polyethylene glycol with srednevekovoi molecular weight of 35,000 (Polyethylene Glycol 35000, firm Merck Ltd.) was dissolved at 70°C in 58% (wt.) the dimethylacetamide to obtain a film-forming solution. The turbidity of this solution was 75°C.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection holes (outer diameter: 1.3 mm, the intermediate diameter: 0.7 mm, inner diameter 0.5 mm, the same injection hole is used in the following examples and comparative examples)was given to go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 77°C, followed by removal of solvent in water at 60°C. the Characteristics of the resulting film are shown in table including any of the following examples.

Example 2

30 wt.% the same PVDF polymer as that used in example 1, and 13 wt.% the same polyethylene glycol as the one used in example 1 was dissolved at a temperature of 70°C in 57% (wt.) Dima is ylacetamide to obtain a film-forming solution. The turbidity of this solution was 76°C.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection hole, gave the go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 80°C, followed by removal of solvent in water at 60°C.

Example 3

27 wt.% the same PVDF polymer as that used in example 1, 9 wt.% the same polyethylene glycol as the one used in example 1 and 6 wt.% polyethylene glycol with srednevekovoi molecular weight of 150000 (R-150, the firm Meisei Chemical Works, Ltd.) was dissolved at 60°C in 58% (wt.) the dimethylacetamide to obtain a film-forming solution. The turbidity of this solution was 75°C.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection hole, gave the go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 80°C, followed by removal of solvent in water at 60°C.

Example 4

The porous film with the characteristic membrane of the hollow fiber structure film made entirely under the conditions shown in example 1, except that PVDF polymer used PVDF homopolymer with srednevekovoi molecular weight of 300,000 (SOLEF6010, the company Solvay Solexis, Inc.). The cloud point of the film-forming solution at this time was 75°C.

Example 5

The porous film with the characteristic of the membrane of the hollow fiber structure film made entirely under the conditions shown in example 1, except that PVDF polymer used PVDF homopolymer with srednevekovoi molecular weight 290000 (KF1000, the company Kureha, Corp.). The cloud point of the film-forming solution at this time was 75°C.

Example 6

The porous film with the characteristic of the membrane of the hollow fiber structure film made entirely under the conditions shown in example 1, except that PVDF polymer used PVDF homopolymer with srednevekovoi molecular weight 380000 (SOLEF6012, the company Solvay Solexis, Inc.). The cloud point of the film-forming solution at this time was 75°C.

Comparative example 1

25 wt.% PVDF polymer is the same as the one used in example 1 and 15 wt.% polyethylene glycol with srednevekovoi molecular weight of 6000 (Polyethylene Glycol 6000, the company Wako Pure Chemical Industries; Ltd.) was dissolved at a temperature of 70°C at 60% (wt.) the dimethylacetamide to obtain a film-forming is astora. The turbidity of this solution was 100°C or higher.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection hole, gave the go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 80°C, followed by removal of solvent in water at 60°C.

Comparative example 2

20 wt.% PVDF polymer in the form of PVDF homopolymer with srednevekovoi molecular weight 420000 (KYNAR301F, the company Arkema Co., Ltd.) and 6 wt.% polyethylene glycol is the same as the one used in comparative example 1, was dissolved at 70°To 74% (wt.) the dimethylacetamide to obtain a film-forming solution. The turbidity of this solution was 100°C or higher.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection hole, gave the go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 30°C, followed by removal of solvent in water at 60°C. the membrane of the hollow fibers showed no what kind of strength at elevated pressures and was not able to withstand actual use when filtering.

Comparative example 3

25 wt.% PVDF polymer is the same as the one used in example 1 and 10 wt.% polyethylene glycol with srednevekovoi molecular weight of 500,000 (Polyethylene Glycol 500000, the company Wako Pure Chemical Industries, Ltd.) was mixed with 65% (wt.) the dimethylacetamide. Although this mixture was stirred at 70°C, homogeneous film-forming solution to get it was impossible and it was impossible to make a hollow fibre membrane. In addition, turbidity was impossible to determine because it was impossible to obtain a homogeneous film-forming solution.

Comparative example 4

40 wt.% PVDF polymer in the form of the same PVDF of homopolymer as the one used in example 5 was mixed with 60% (wt.) gamma-butyrolactone, followed by stirring and dissolving at a temperature of 170°C. to obtain a film-forming solution. This solution had a cloud point.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of gamma-butyrolactone was extrudible of dogtramadol injection hole, gave the go with the free movement distance of 50 mm, and utverjdali in 80%aqueous solution of gamma-butyrolactone at a temperature of 30°C and following the removal of solvent in water at 60°C.

Example 7

25 wt.% PVDF polymer in the form of the same PVDF of homopolymer as the one used in example 1 and 15 wt.% polyethylene glycol with srednevekovoi molecular weight of 20,000 (Polyethylene Glycol 20000, the company Wako Pure Chemical Industries, Ltd.) was dissolved at a temperature of 70°C at 60% (wt.) the dimethylacetamide to obtain a film-forming solution. The turbidity of this solution was 78°C. In Fig. 1 shows a19F NMR spectrum used in example 7 PVDF polymer with the contents of the irregular sequences of 9.4%.

To obtain a porous film with typical membrane of the hollow fiber structure of the film, this film-forming solution together with the internal liquid in the form of water were extrudible of dogtramadol injection holes in the same way as the one described in example 1, gave the go with the free movement distance of 200 mm, and utverjdali in water with a temperature of 80°C, followed by removal of solvent in water at 60°C.

Structural analysis

Analyzed the structure of the porous film according to example 7. In Fig. 2 shows an electron micrograph (magnification: h) surface with a higher density (outer surface) of the porous film according to example 7, while in Fig. 3 shows an electron micrograph (magnification: h)obtained for the region near the center of t is lstay part of the porous film according to example 7. As shown in Fig. 2 and 3, the porous film according to example 7 has a dense surface, which on the surface thereof formed numerous pores. In addition, it was confirmed that the cross-section of the porous film base of the hollow ring-shaped polymer components of the three-dimensional crosslinked with the formation of the mesh grid, resulting in obtaining a film with a structure with many pores. In addition, it was confirmed that the total thickness of the hollow annular polymeric component increases from the edge surface with a higher density are shown in Fig. 2, in the direction of the center thick part of the film, as shown in Fig. 3.

Evaluation of resistance to chemical reagents

Test of resistance to chemical reagents was performed using a porous film with a characteristic of the membranes of the hollow fiber structure of the films obtained in examples 1-7 and comparative examples 1, 2 and 4. After immersion of the membrane of the hollow fibers were removed from the chemical reagent after 1, 3, 7 or 14 days, sufficiently washed with water and subjected to a tensile test. The results are shown in the table.

Example 2 357,5
Table
When Mer 1Example 3Example 4Example 5Example 6Example 7EUR. example 1EUR. example 2EUR. example 3EUR. example 4
The degree of crystalli-knosti PVDF polymer (%)626560677067656157-71
Average specific area over a surface of the porous film (m2/g)6,85,513,17,07,4the 10.16,235,33,1-98,6
Production management degree crystal personality on the specific area over a surface film (%·m2/g)421,6786469518676,74032153,3176,7-7000,6
The total content
abolition Chris-metal β-type and γ-type (%)
272527153316262838-55
OST-
the exact content of PEG in the membrane of the hollow fibers (weight. %)
1,92,53,51,92,22,50,200-0
Medium-weight Molek-lar mass of PEG in membre not hollow fibre (Mw)400003700024500042000 420004500025000----
Content-the content of deregu-regular sequences in the PVDF polymer in the membrane of the hollow fiber (%)9,49,49,48,67,88,69,49,410,3-7,8
The flow of pure water (l/m3·h @ 0.1 MPa)950510120098088010501000110600-500
The content of the hydrophobic polymer component in the spinning solution (wt.%)273027272727 25202540
The contents of the irregular sequences in the original substance representing PVDF polymer (%)9,49,49,48,67,88,69,49,410,39,47,8
The content of the hydrophilic polymer component in the spinning solution (wt.%)15131515151515156100
Average-weight molecular weight of the original substances-VA, Chairman of table-found a PEG (Mw)3500035000810003500035000350002000 60006000500000-
Unwise-they maintain-tion method-ness to the elongation grow hereto after immersion for 3 days (%)888580736780881990-11
Unwise-they maintain-tion method-ness to the elongation grow hereto after immersion for 7 days (%)80816961426872882-5
Adjusted they saving
in a way-ness to the elongation grow hereto after immersion for 14 days (%)
767860601862 67575-The impossible is possible determi-share
The way of the active extracts from jobstears experience pressureAboutAboutAboutAboutAboutAboutAboutAboutThe impossible can be evaluated-About

Because of the high chemical resistance to chemical reagents and the like for PVDF porous film of the present invention, it manifests while maintaining a high permeability, the porous film can be used for a long period of time in applications that are mixed with laundering alkaline solutions and other chemical reagents suspended matter and other organic substances accumulating on the surface of the film is the result of the filter. Moreover, since the PVDF film of the present invention can be produced as easily and invariant, it contributes to increased productivity and efficiency. For this reason, it can be widely and effectively used in the region is, requiring film exhibiting high permeability and high resistance to chemical agents during the laundering chemicals suspended matter and other organic substances accumulating on the surface of the film is the result of the filter, such as water treatment at water treatment plants, filtration of river water and lake water filtration purification of industrial water and wastewater treatment and filtration treatment fluids, such as pre-treatment for seawater desalination.

1. The porous film as a membrane for filtering comprising a polymer component containing polyvinylidenfluoride (PVDF) polymer as a main component thereof and a glycol with srednevekovoi molecular weight of 20,000 or more but not more than 300,000, as a hydrophilic component,
where the degree of crystallinity of PVDF polymer is 50% or more but not exceeding 90%,
the content of crystals of β-type crystals of γ-type crystalline part of the PVDF film is 30% or less of the total content of the crystalline part in PVDF polymer, and
the product of the degree of crystallinity of PVDF-polymer on the surface area of the film is 300 %·m2/g or more but not exceeding 2000 %·m2/year

p> 2. The porous film according to claim 1, which contains polyethylene glycol in an amount of 0.01 parts or more but not more than 3 parts per 100 parts of PVDF polymer.

3. The porous film according to claim 1, in which according to the measurement method19F NMR spectroscopy contents intramolecular irregular sequences in the PVDF polymer is 8.8% or more but not exceeding 30,0%.

4. The porous film according to claim 1, where the porous film has a film structure, characteristic of the membrane of the hollow fibers.

5. The porous film according to claim 1, where the porous film has a film structure in which the basis of the polymer component forms a mesh grid, and it contains pores, and the total thickness of the polymeric component increases continuously or discontinuously, at least up to 1/5 of the thickness of the film from the edges of the upper and lower surfaces of the film with a higher density.

6. The method of washing a porous film, comprising contacting a porous film according to claim 1 with an alkaline solution.

7. The method of filtration comprising contacting a porous film according to claim 1 alternately at least once with an aqueous solution and an alkaline solution.

8. A method of obtaining a porous film according to claim 1, comprising obtaining a porous film containing polyvinylidenfluoride (PVDF) polymer as a main component, the extrusion molding hole is supplying film-forming solution, which includes at least a hydrophobic polymer component containing PVDF-polymer as a main component, a hydrophilic polymer component and the total for both hydrophobic and hydrophilic polymer components of the solvent, and curing the film-forming solution in a solution containing water as a main component, where
as the hydrophilic polymer component using polyethylene glycol with srednevekovoi molecular weight of 20,000 or more but not exceeding 150000,
the common solvent is at least one solvent selected from the group comprising N-organic (NMP), dimethylformamide (DMF), dimethylacetamide (DMAC) and dimethyl sulfoxide (DMSO), and
the temperature of the solution to curing the film-forming solution (Tb°C), the temperature of the film-forming solution (Td°C) and the cloud point of the film-forming solution (TC°C) satisfy the relation Td+5≤Tb≤Td+30 and the ratio of Td≤Twith≤Tb.

9. A method of obtaining a porous film of claim 8, in which the PVDF-PVDF polymer used is a polymer, the content of intramolecular irregular sequences in which according to the measurement method19F NMR spectroscopy is 8.8% or more but not exceeding 30,0%.

10. The way recip is of a porous film of claim 8, in which film-forming solution contains 20 wt.% or more but not more than 35 wt.% the hydrophobic polymer component and 8 wt.% or more but not more than 30 wt.% the hydrophilic polymer component.

11. A method of obtaining a porous film of claim 8, in which the injection hole is doctrate injection hole, and a porous film with the structure characteristic of the membrane of the hollow fibers, is produced by extrusion film-forming solution from the injection holes together with contributing to the formation of cavities reagent and curing the film-forming solution in a solution containing water as a main component thereof.

12. A method of obtaining a porous film of claim 8 in which the film-forming solution as a General solvent contains at least dimethylacetamide.



 

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1 tbl, 3 ex

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FIELD: chemistry.

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FIELD: chemical power sources.

SUBSTANCE: fuel cell comprises proton-conducting diaphragm of solid electrolyte from both sides of which the catalytically active metallic grids are arranged. The metallic grids represent current-collecting electrodes and are provided with passages for supplying fuel and oxidizer to the current-collecting electrodes. The proton-conducting diaphragm of the solid electrolyte is made of a composite material with a filler made of fiber glass textile.

EFFECT: simplified design and enhanced reliability.

1 dwg

FIELD: chemical industry; methods of production of the thermocross-linked polyvinyl acetals.

SUBSTANCE: the invention is pertaining to: the thermocross-linked polyvinyl acetal produced at least from one polyvinyl acetal (I), which is the result of the interaction of at least one polymer (A) containing in the mass % in terms of the total sum of the polymer (A)- a) 1.0-99.9 of the structural links of the formula (1), - b) 0-98.9999 of the structural links of the formula (2), - c) 0.0001-30,0 of the structural links of the formula (4), with the compound (B) of the formula (5); at that at least partially the groups of the formulas (1) and (4) are etherifying with one another. The invention also is pertaining to: the method of the cross-linking of the polyvinyl acetal (I) at the temperature of the mass within the limits from 120°С up to 280°С, in the case of necessity, together with at least one plasticizer; to the molding mass containing the indicated polyvinyl acetal; to the produced out of the molding mass film for manufacture of multilayered safety glasses and to the coating; and to application of the molding mass for production of the ionic-conducting layers for the electrochromic systems. The presented polyvinyl butyral (PVB) is produced with the high reproducibility and without addition of the separate cross-linking agent. The films containing the given high-molecular cross-linked polyvinyl acetal, have the lowered flow index of their melt, and the coatings have the improved resistance to the dissolvents.

EFFECT: the invention ensures, that the films made out of the high-molecular cross-linked polyvinyl acetal have the lowered flow index of their melt and the coatings made out of the high-molecular cross-linked polyvinyl acetal have the improved resistance to the dissolvents.

15 cl, 16 ex

FIELD: chemical engineering.

SUBSTANCE: method comprises producing heterogeneous ion exchange film by rolling a mixture of ionite and polymeric binder and supplying the mixture to the calender. The film calendered at a temperature of 125-135°C is provided with reinforcing material and material preventing the film to be glued to the surface of the press.

EFFECT: improved quality of diaphragm.

5 ex

Bipolar membrane // 2290985

FIELD: bipolar membrane used in hydrometallurgy and method for manufacturing the same.

SUBSTANCE: method involves providing simultaneous joint hot pressing and reinforcement with synthetic fabric from monopolar filaments of sulfocationite membrane based on macroporous sulfocationite with highly developed surface having specific surface value equal to 10 m2 and membrane based on benzyltrimethyl ammonium anionite. Both membranes are manufactured with the use of low-pressure polyethylene.

EFFECT: improved electromechanical properties of membrane.

1 tbl, 1 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to polymer mixture for use in membrane manufacture. Mixture contains (i) at least one acrylic polymer or at least one acrylic polymer and at least one vinyl polymer, which polymers comprise at least one ionic or ionizable group, in particular sulfurized group, and (ii) at least one thermoplastic fluoropolymer, provided that components (i) and (ii) differ from each other. Invention also related to polymeric ionic membrane, membrane electrode complex, fuel cell, battery, and to a polymer mixture and composition preparation process.

EFFECT: enabled production of fluoropolymer uniformly mixing with other polymers, enabled manufacture of membrane directly from aqueous fluoropolymer dispersions, and increased chemical resistance and mechanical strength of membranes.

25 cl, 5 tbl, 13 ex

FIELD: chemistry.

SUBSTANCE: invention relates to production of shrinkable polymer labels, particularly to preparation of a film composition. The composition contains (a) a high-impact polystyrene component (HIPS) with a block-copolymer grafted to the polystyrene, (b) 10-50 wt % general purpose polystyrene (GPPS) and (c) approximately 2-80 wt % styrene block-copolymer. Component (a) contains a grafted rubber component which is a styrene block-copolymer and a rubber-like diene with conjugated double bonds from 1 to 7 wt % of the weight of the HIPS; less than 10 wt % concentration of gel, defined by extraction of the methylethylketone/methanol mixture. The average particle size of the rubber is less than 1 mcm and 0.01 mcm or more. Approximately 40-90 vol % of the rubber particles have diametre approximately less than 0.4 mcm and approximately 10-60 vol % of the rubber particles have diametre of approximately 0.4-2.5 mcm. Most of the rubber particles have a nucleus-shell morphology and said particles are in concentration of 10-70 wt % of the total weight of the polymer composition, and 1-5 wt % of the rubber-like diene of the total weight of the polymer composition.

EFFECT: film made from said composition has ratio of directed length to non-directed length in the direction of the greatest drawing at least equal to 3:1 and enable increase in size by 20% in the direction of less stretching at 110°C.

10 cl, 3 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing electroconductive gas-sensitive material for a nitrogen dioxide sensor. The method of producing gas-sensitive material involves preparation of a film-forming solution from polyacrylonitrile and copper (II) chloride CuCl in dimethylformamide, which is deposited through centrifuging onto a substrate made from quartz glass and undergoes drying and infrared annealing successively in two steps: on air at temperature 150°C for 15 minutes and at 200°C for 15 minutes; and in an argon atmosphere at T=150°C, 200°C for 15 minutes; and then at T=500-800°C for 5 minutes.

EFFECT: obtaining gas-sensitive material which is sensitive to nitrogen dioxide with semiconductor properties from material which has dielectric properties using infrared annealing.

3 tbl, 2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to multilayer metallised biaxially-oriented polypropylene films used for food packing and to method of their production. Said film comprises main layer A made from crystalline home- or copolymers of propylene comprising bonds C2-C10 of alpha-olefine, one top layer B made from propylene copolymer containing 3 to 6 wt % of the bonds of linear C4-C10-1-alkene, and metal layer M applied on the surface of top layer B. Propylene copolymer of layer B has fraction soluble in xylene at 23°C, less than 4.0 wt %, Vick softening point above 135°C indenter depth in Vick test smaller than or equal to 0.05 mm at 120°C. Method of film production comprises co-extrusion of layers A and B, biaxial orienting of co-extruded layer A and B, treatment of top layer B surface and metal deposition on said layer.

EFFECT: multilayer metallised biaxially-oriented polypropylene films with high oxygen and steam barrier properties.

FIELD: process engineering.

SUBSTANCE: proposed method allows producing extruded one- or multilayer polymer film 8 with a structure produced therein at least partially. Said film is produced by stamping. Finished film 8 features thickness of 1 to 1500 mcm, preferably, of 30 to 300 mcm. Structure features depth of 1 to 1000 mcm, preferably of 5-300 mcm, particularly preferably, of 10-20 mcm. Width of structure groove 9 makes 1-1000 mcm, preferably, 10-500 mcm, particularly preferably, 40-80 mcm. Distance between structure grooves 9 makes 1-1000 mcm, preferably, 100-500 mcm, particularly preferably, 200-300 mcm. Note here that produced may be linear or linear-crossed structure with grooves 9. Said film is intended for packing and may be produced as described in invention claims. Said polymer film 8 is jointed with other layers of package materials 6, 7, and polymer film 8 is supplemented by other layers of package materials 6, 7, and package breakage pattern is defined by polymer film 8.

EFFECT: polymer film that allows ease of marking, breaking at preferable direction.

15 cl, 5 dwg

FIELD: chemistry.

SUBSTANCE: thermoplastic material, having a polyethylene matrix which contains 1-70 pts. wt polypropylene per 100 pts. wt polyethylene matrix, is used to make medical and hygienic films. After heating, said material is passed through a pressing zone between cooled rollers, where the initial film-type linen is heated to molten state of the material of the polyethylene matrix but not up to temperature of molten polypropylene.

EFFECT: inproved operational characteristics of film-type linen including for films with thickness equal to less than 20 mcm.

25 cl, 1 dwg, 6 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a monolithic sheet for light scattering shaped articles used in flat screens. The sheet is made from a composition which contains (a) 80-99.99 wt % transparent polycarbonate with ISO 13468-2 light transmission greater than 88.5% (for sample thickness of 4 mm), and (b) 0.01-20 wt % poly(meth)acrylate particles with nucleus/shell morphology, particle size of 0.5-100 mcm, and refraction index different from the refraction index of transparent polycarbonate. The sheet does not contain a dye selected from a group comprising antanthrones, anthraquinones, benzimidazoles, diketopyrrolopyrroles, isoindolinols, perynones, perylenes, phthalocyanines, quinacridones, quinophthalones and their combinations, but additionally contains 0.001-0.2 wt % optical bleaching agent and 0.01-0.5 wt % UV-absorber.

EFFECT: invention enables to obtain monolithic sheets with thickness of 2 mm with high degree of light transmission and brightness.

9 cl, 1 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention relates to making articles with an elongated shape with a regular microrelief on the surface, which can be used as elements of optoelectronic devices and information display systems. In the first version, articles with an elongated shape made from glass-like non-oriented or partially oriented polymer are treated with low-temperature plasma. The articles are then heated to temperature higher than the glass transition point (Tg). The articles are stretched in at least one direction. The articles are cooled to temperature lower than Tg of the polymer while fixing the size of the article in the direction of stretching. In the second version, the non-oriented or partially oriented article made from amorphous glass-like or polycrystalline polymer is treated with low-temperature plasma. The article is stretched at temperature lower than Tg for the amorphous polymer and lower than melting point (Tm) for the polycrystalline polymer. In the third version, an article in high-elastic state of the polymer is treated with low-temperature plasma. The article is stretched while fixing the size of the stretched article in the direction of stretching. In the fourth version, an article made from amorphous or polycrystalline polymer is used. The article is stretched at temperature higher than Tg for the amorphous polymer and lower than Tm for the polycrystalline polymer. The article is treated with low-temperature plasma while fixing the size of the article with subsequent removal of the fixing.

EFFECT: easier formation of a regular microrelief on the surface of polymer articles.

8 cl, 7 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: method involves preparation of two solutions of a mixture of 5(6)-amino-2(para-aminophenyl)benzimidazole with 5(6)-amino-2(para-iminoquinone)benziimide in dimethylacetamide which contains lithium chloride, and then addition of paraphenylenediamine and an equimolar amount of terephthaloyl chloride to the first solution, and to the second solution - an equimolar amount of a dianhydride of pyromellitic acid. Said solutions are mixed at room temperature until formation of a spinning solution with dynamic viscosity of 300-600 P and concentratio of 3.5-4.0 wt %. The solution is filtered, vacuum treated and formed in a water-salt or water-alcohol settling bath, dried and thermally treated in free state. Industrial fireproof ballistic fabric is then produced from the obtained fibres. Threads obtained according to the invention have elementary fibre diametre higher than 10 mcm, rupture resistance not lower than 280 cN/tex and relative elongation of 3.8-4.5%.

EFFECT: invention enables to obtain fibres, threads, films with high elasticity while retaining good strength properties.

2 cl, 3 tbl, 4 ex

FIELD: process engineering.

SUBSTANCE: invention relates to polymer intermediate layers used in multilayer-glass panels. Intermediate layer comprises extruded layer of poly(vinyl butyral) including first coextruded skin-layer of poly(vinyl butyral) with thickness less than 0.15 mm that contains additive selected from the group adhesion regulators, pigments, coloring agents UV-and IR-radiation absorbers. Note here that said poly(vinyl butyral) sheet contains less than 10% of said additive.

EFFECT: higher efficiency of application of said additives that add to operating properties.

6 cl, 3 dwg

FIELD: chemistry.

SUBSTANCE: composition contains a mixture of a low molecular weight polyethylene component and a high molecular weight polyethylene component and a binding agent containing at least 0.0025 wt % polysulphonyl azide. The mixture has sine peak on the lamella thickness distribution (LTD) curve.

EFFECT: prolonged wear resistance of pipes under gas or water pressure, resistance to cracking under stress associated with environmental factors, resistance to slow formation of cracks, to fast crack propagation and to creep under internal stress.

64 cl, 3 dwg, 24 tbl, 6 ex

FIELD: process engineering.

SUBSTANCE: invention relates to method of producing composite membranes with fullerene-containing polymer selective layer to extract ethers in alkyl acetate hybrid process. Proposed method consists in forming selective diffusion polymer layer on microporous substrate. Microporous substrate is represented by microfiltration membrane from copolymer of vinylidene fluoride with lavsan-based tetrafluoroethylene. Selective layer is the mix of poly(phenylene oxide) and fullerene C60. Selective layer is formed by applying 2%-solution of aforesaid mix onto surface of said microporous substrate and drying it.

EFFECT: composite membrane with improved transfer properties for extracting ethers.

1 tbl, 3 ex

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