The method of obtaining porous fibrous material

 

(57) Abstract:

The invention is intended to obtain porous materials on the basis of tannery wastes and low grade raw materials and is more simple and cheap process for the production of porous fibrous collagen material, provides the feedstock expansion of these materials. The method of obtaining porous fibrous collagen containing material includes the preparation of a collagen dispersion in an alkaline environment, the introduction of cross-linking agent in collagen dispersion in an alkaline medium, freezing the resulting composition with subsequent thawing and finish. The method allows to exclude a number of energy-intensive and long-term stages, guide to the process wastewater from the stage of the ashing. 2 C.p. f-crystals, 1 table.

The invention relates to the leather industry, specifically to a method for producing porous materials on the basis of tannery wastes and substandard raw materials.

For existing technologies manufacture natural skin characterized by the formation of a large number trudnoozhidaemyh waste, including waste containing main peopoe raw materials, which in large quantities landfilled, where rotting, it adversely affects the ecological situation in the regions.

The number of known methods of transformation of tannery waste materials for various purposes. In particular, describes a method for collagen containing material that imitates natural skin [2], which consists in freezing and thawing of the composition consisting of the products of dissolution of 4.5-5.0 wt.h. collagen 100 wt.h. 0.1 M aqueous solution of phosphoric acid, crushed waste tanned leather, glutaraldehyde and water. Product dissolution of collagen derived from holeway trimmings, which is ground, treated with alkali-salt solution, washed to pH 7-8, and then dissolved in an aqueous solution of phosphoric acid. Prepare a paste of tanned collagen, which chips tanned skin pour 4 volumes of water and ground in a homogenizer for 3-5 min at room temperature. The obtained components are mixed in a predetermined ratio, add a crosslinking agent and stirred for 2-3 minutes Ready weight put on pallets and thermostatic in a freezer at -70...-10oC, then thawed at room temperature, washed, what s necessary stage:

- alkaline-saline processing of the hide (10-12 h),

- neutralization of the hide (6-8 h),

- dissolution of the hide in acetic acid (10-12 h),

- dispersion tanned shavings in water (1-3 h),

- preparation of a mixture of components with stapler (0.5-1 h),

- freeze mixture (0.5-1 h),

- maintaining material with a negative temperature (24 h),

- thawing, washing and drying in the air (24-36 h).

The duration of the technological process in total is 76-96 PM

The described method includes material and energy-intensive stage alkali-salt and acid treatment holeway trimmings and long maturing of the frozen material in the cryochamber, and alkali-salt solution together with the products of partial dissolution of collagen is discharged into the waste water, which entails the necessity of their treatment. The material obtained in accordance with the described method has a low deformation-strength properties (ultimate tensile stress of 4.95-5,75 kg/cm2, elongation 20-28%).

Also known is a method of obtaining fibrous material [3], which includes grinding redoubling waste leather proizvodstva of sodium sulfate, subsequent washing in running water, followed by acidification of the mixture of 9% solution of acetic acid and keeping it within 24 hours Swollen in acid particles of the raw material is then homogenized, getting acetic acid solution of collagen. Tanned leather shavings milled in water to a particle size of 0.2-0.6 mm, the resulting acetic acid solution of collagen is mixed with water paste tanned waste ratio, providing the content in the formed mass of 0.2-2.0 wt.% nedubrovo collagen and 0.3 to 1.0 wt.% tanned collagen. In the resulting mass was cooled to 0-5oC, introduce a crosslinking agent is glutaric aldehyde in the amount of 0.15-7.0 wt.%. The resulting mass to form a layer, which is subjected to structuring, cooling to a temperature of -75 -14...oC for 0.1 to 2.0 hours and soaking in the specified temperature range within 4-24 hours After thawing, the resulting material is heated to a temperature of 105oC, treated with alkali-salt solution, wring out, subjected to hot-pressing, followed by the usual in the manufacture of natural leather trim.

The above-described method comprises the following steps:

- alkaline-saline processing of the hide,

- promny tanned shavings in the water,

- cooling components to 0-5oC,

- preparation of a mixture of components with a stapler,

- freeze mixture,

- keeping material at subzero temperatures,

- defrost,

- heating the material at a temperature of 105oC,

- alkaline-saline treatment,

- wringing, pressing, embossing.

This method is due to the existence of stages of leather processing allows you to obtain a softer and more durable material than previously described, but also has several disadvantages. The presence of two stages of the alkali-salt processing increases the cost of the process, because the solutions are used once and then when washing fall into the waste water, which leads to the need for cleaning the latter. In addition, to obtain a dispersion of tanned collagen is used only leather shavings, because in a neutral or slightly acidic environment, this type of large-scale waste, as the leather flap, practically does not swell and therefore the dispersion is technically difficult task, i.e., the known method is not enough universal in respect of the raw materials used. Carrying out a reaction between a binder with collagen in an acidic medium with a negative temperature p the spine staple in these conditions, that also affects the cost of the process due to the significant energy costs.

The closest analogue of the invention is a method of obtaining a porous fibrous collagenopathies material, comprising preparing a collagen dispersion in an alkaline environment, the introduction of cross-linking agent, freezing the resulting composition with subsequent thawing and finish of the material obtained [4].

The technical result of the invention is to provide a more simple and cheap process for the production of porous fibrous collagen containing materials, as well as strengthening their resource base.

This result is achieved in that a method of obtaining a porous fibrous collagen material according to the invention includes the preparation of a collagen dispersion in an alkaline environment, the introduction of cross-linking agent, freezing the resulting composition with subsequent thawing and finish. In the way of a crosslinking agent injected into the collagen dispersion in an alkaline environment. As the alkaline environment of the use of 0.4-4% solution of caustic soda and/or wastewater from the stage of the ashing. At the same time as the stapler is applied di - and polif the dicarboxylic acids, the diisocyanates.

The method of obtaining porous collagen-fibrous material according to the invention comprises the following steps:

alkaline processing of raw materials,

- the dispersion of the swollen raw material

- cooling of the collagen dispersion to a temperature not lower than the freezing point of the dispersion,

- preparation of a mixture of a dispersion of collagen with stapler,

- freezing the dispersion,

- defrost material,

- pressing and dressing.

The choice of parameters of technological process due to the following points:

1. The invention can be used to process all kinds of collagen containing waste, namely: holeway parings and flap with stage ashing, razdolblennye leather fibre, leather shavings and flap from the stage of planing, grinding and ghosting natural leather, because the conduct of swelling in an alkaline environment facilitates subsequent dispersion even such trudnoozhidaemyh waste, as the leather flap.

2. The duration of the alkaline treatment of the collagen raw material (12-120 h) provides this degree of swelling, which then allows to carry out in the shortest time subsequent dispersion is an increase in the duration of the alkaline treatment more than the claimed time economically.

3. As the alkali solution used is 0.4-4% solution of caustic soda and/or wastewater from the stage ashing, containing in addition to the inorganic components of the products of dissolution of wool keratin, present in the composition gives the ultimate material for increased strength. The concentration of alkali was found experimentally, according to the present invention, it is 0.4-4%.

4. The solids content in the aqueous dispersion of collagen waste is 0.5-5%. When using less concentrated dispersions material does not have the necessary strength characteristics. When using more concentrated dispersions difficulties in the distribution of variance in volume form.

5. As a staple, use di - and polyfunctional organic compounds, the rate of interaction with collagen in alkaline medium is that it allows you to eliminate lengthy and energy-intensive stage of keeping the material in a frozen state. Such substances are, for example, glutaric, succinic (glyoxal) or terephthalic dialdehyde, diepoxide or epichlorohydrin, galodamadruga dicarboxylic acids, diisocyanates, taken in an amount of 0.5-5%. The device of the material does not have sufficient strength characteristics. More staple impractical, since the formation of the spatial cross-linked structure to the distribution of variance in volume form.

6. Dispersion of collagen is cooled to a temperature below the freezing point of the dispersion (0oC) prior to the introduction of cross-linking agent, and this temperature is maintained during the homogenization of the composition, because the speed of chemical processes in the specified pH range is such that the formation of spatial cross-linked structure may fail to freeze the reaction mass, resulting in unable to obtain characteristic of porous fibrous structure.

7. Aqueous collagen dispersion is frozen at a temperature of -10 to -75oC. When conducting stage freeze at a higher temperature due to the effect of hypothermia is a high probability of unfrozen areas, which leads to non-uniformity of material properties. Conducting freeze at lower temperatures is impractical due to high energy costs.

8. The duration of the stage of freezing (15-120 min) was found empirically, based on the need for uniform and full EcoObraz.

9. After thawing, the material is subjected to processing, tanning and oiling compositions by known methods similar stages of tanning leather. This stage is an integral part of the proposed technical solution in General, i.e. is included in the combination provided by this invention.

Comparing the method according to the invention with the prototype, you can see that in this technical solution is completely excluded the following material and energy-intensive stage:

- washing of the hide in running water after the alkali-salt processing,

- processing and grinding of the hide in a solution of acetic acid,

- keeping material at subzero temperatures,

- heating of the material at 105oC,

- alkaline-saline treatment.

Therefore, solved a basic problem of the invention is the simplification and cheapening of the technological scheme of production of porous fibrous collagen containing materials. Use as reaction medium alkaline solution leads to the solution of another urgent issue is the expansion of raw materials, because in an alkaline environment all collagen containing waste from the leather industry well swell and therefore imagevenue chips humidity 50%, crushed on the homogenizer knife or abrasive type, add 1000 ml of water, mix, then add 13000 ml of 0.4% sodium hydroxide solution and maintain the dispersion at a temperature of 20oC for 72 h Content tanned with chromium salts of collagen in the obtained dispersion is 3 wt. %. The dispersion is cooled to a temperature of 0oC, add 150 ml of 25% aqueous solution globalusage aldehyde, mix and spread over the plane or three-dimensional form. The dispersion is frozen at -40oC for 120 min, then thawed by immersing the form in hot water. After thawing, centrifuge, drying and finishing operations, the material has a tensile strength of 20 kg/cm2when the relative elongation of 28%.

Other examples illustrating the invention is shown in the table (examples 2-10).

This technological solution has the following advantages compared to previously known methods:

- the exclusion of a number of energy-intensive and long-term stages allows to obtain a porous fibrous materials more economically advantageous way, the method allows to significantly simplify the instrumentation process with simultaneous increase effective geologicheskiy schemes in General;

the method allows to send to the process wastewater from the stage ashing, which saves costly reagents and reduce the load on the existing treatment plant, which also reduces the cost of the process;

- greatly expanding the raw material base obtain a porous collagen-fibrous materials through the use of previously non-recyclable waste, such as leather flap.

1. The method of obtaining porous fibrous collagen containing material, comprising preparing a collagen dispersion in an alkaline environment, the introduction of cross-linking agent, freezing the resulting composition with subsequent thawing and finish of the material obtained, characterized in that the crosslinking agent is introduced into collagen dispersion in an alkaline environment.

2. The method according to p. 1, characterized in that the alkaline environment of the use of 0,4 - 4,0% solution of caustic soda and/or wastewater from the stage ashing.

3. The method according to p. 1, characterized in that as the cross-linking agent used di - and polyfunctional organic compounds, such as dialdehyde, diepoxide or halohydrin, Galoyan the

 

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FIELD: polymer materials.

SUBSTANCE: sheet porous collagen-containing material, suited to be used in footwear, furniture, and vehicle manufacture, comprises water-soluble plasticizer and particles of hydrophilic filler in the form of fibers with length-to-diameter ratio between 5 and 500. At least 50% of fibers are parallel to sheet sides with largest surface areas. This sheet is characterized by rupturing relative elongation when stretched in one direction in planes of the largest sides equal to 10-30%, modulus of compression elasticity for thickness equal to 50-300 kPa, and coefficient of thickness restoration after 70% compression for 5 h equal to 0.90-0.95 at 8-12% moisture. Also described is method of manufacturing such material including following operations: mixing hydrophilic fibers having length-to-diameter 5-500 with aqueous collagen solution and multifunctional cross-linking agent to form homogenous mass containing 1-20% fibers, 1-5% collagen, and 0.2-20% cross-linking agent; freezing liquid sheet and unfreezing it followed by pressing resulting porous sheet; softening with water-soluble plasticizer; second pressing; and drying.

EFFECT: enhanced damping ability of sheet and simplified manufacturing technology.

8 cl, 2 tbl, 10 ex

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