SU460633A3 - The method of obtaining artificial leather - Google Patents

Description

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A method for producing artificial leather is known by repeatedly applying a fiber layer of a solution of polyurethane or its mixture with other polymers with increasing concentration impregnated with a binder, coagulation, washing and subsequent drying; “But although this achieves a different density of polyurethane across the layers of the front coating, but artificial skin is not similar to natural in its structure and properties.

For the purpose of obtaining artificial leather, according to the structure and properties close to natural leather according to the invention, each subsequent layer of polyurethane solution (or its mixture with other polymers) is applied after the fiber layer is completely absorbed by the fibrous mat.

Fibrous mats comprising at least 1 part of synthetic fibers and having a density of 0.08-0.30, mainly 0.12-0.20 g / cm, are used as the starting material. Such mats are prepared on a carding machine or papermaking process and compacted by heating.

The concentration of elastomeric pacTBOipOB is 8-35, preferably 12-30 wt. % The concentration of the individual solutions, applied successively one after the other, is chosen in accordance with the density of the fibrous mats so that the final product has the greatest possible difference in the density of the upper and lower sides.

For the manufacture of artificial leather with a possible (more dense upper side, i.e., with the structure most closely resembling the structure of natural leather, the compaction of fibrous mats is additionally introduced during the coagulation of elastomers.

act in such a way that after the onset of coagulation of the elastomeric binder; the substances impregnated fibrous mats are compressed in a water bath with rotating rollers. This process can be repeated several times.

time. Thus, the density of the upper side of the finished imitation leather can be increased by 30-60% compared to uncompressed leather. Solutions of polyurethane in dimethylformamide or other known solvents are mainly used as an impregnating agent. To improve the neck and flexibility of artificial leather, you can add 5-30 weight to the elastomer solution (A). % paraffin or horse force (relative to the elastomer). The elastomer solutions applied on the upper side can contain up to 35 wt. % of polyvinyl chloride or copolymers of polyvinyl chloride with respect to the total content of polymers, such

the thermal stabilization of the material is enhanced, which is of particular importance in the further processing of artificial leather in the shoe industry.

Example 1. On a paper machine: 1 fabric was made from polyamide and regenerated cellulose fiber dispersion (80:20 ratio). This batt is compacted by short-term heating.

For impregnation through the web, elastomer solutions A – C are used as follows; its composition, wt. %: Polyurethane Dimethylformamide Silicone oil Vinyl chloride / maleic anhydride copolymers Water Polyurethane used in all solutions is a product of polybutylene adipate with an average molecular weight of about 1000, diphenylmethane-4,4-diisocyanate and butane diol in a molar ratio of 1: 3, 3, 3, 3, 3, 3, 3, 3, 3, butanediol in a 1: 3, 3, 3, 3 molar ratio, 1: 3, 3, 3, 3-diisocyanate and butane diol in a molar ratio of 1: 3, 3, 3, 3, 3, 3, 3 2.1. Silicone oil is phenyl methyl field, isiloxane. PacTBOipbi is heated to 45 ° C and degassed. Fibrous iriches are fed to the roll doctor at a speed of 1 m / min. The roller is moved in the bath, filled with solution A. Next to the place of contact between the roll and the upper side of the batt, the scraper is installed on some work from the surface of the roll, KOTOipbm cuts the solution to thickness, and 0.5 mm of a layer. The impregnating solution batt transported to the bottom side is about 0.5 kg per meter of impregnation. By means of a doctor blade installed at the height of the roller axis above the batt, solution B is applied simultaneously. The gap between the doctor blade and the batt upper side is 0.6 mm. 0.77 kg of solution B is applied per square meter of fibrous mat. The webbing is carried out freely with a 0.6 m squeegee and then passed between a pair of rolls. Before the batting in the rollers, solution B completely penetrates into the fibrous mat, which looks volOKnisty and almost dry. The rolls are set in motion with a circumferential speed of rotation of 1 m / min. The gap between the roll 1 and 2.1 mm, so that the impregnating solution does not spin. At a distance of 0.5 m behind this pair of rolls, the next blade, which is set at a distance of 0.7 mm from the top surface of the batt, is applied to the next blade, and 0.8 г g of solution C is applied to 1 m of fiber mat. . At a distance of 2 m behind a rollerblade, the batt enters a water bath with a temperature of 40 ° C, in which the polymers coagulate and wash off the solvent, then the batt is dried.

Example 2. The method described in Example 1 is repeated using a fiber batt of the composition indicated. Polymeric {solutions A – C, applied successively one after another, have the following composition, wt.%:

The sun

Polyurethane16,0

18.0 20.0

Paraffin oil2.0

6.0

4.0

Water6.0

Dimethylformamide 76.0 76.0

71.0

5.0

Vinyl chloride-Copolymers Polyurethane is obtained by converting polybutylene adipate, dnfenilmeta | H-4,4-di (Isocyanate and butanediol in a ratio of 1: 2: 1. After applying the solution in accordance with Example 1, the impregnated bat without compression during coagulation is passed through water bath. The weight of 1 m of artificial leather is 775 g and the thickness is 1.29 mm, The density of three layers with a thickness of up to 0.43 mm is below BBQpx 0.52, 0.60, 0.68 g / cm. Example 3. Artificial skin is made of a fibrous bat (Example 1) by impregnation according to Example 1, and successively one after another, the A-C solutions have the following composition, wt%: Polyurethane Paraffin oil Water Dimethylformamide Vinyl chloride copolymers Polyurethane is obtained by converting polybutyl enadipate, diphenylmethane-4,4-diisocyanate and butanediol in a ratio of 1: 2.5: 1.5. The coagulation process is carried out without the use of compression. The weight of 1 m of artificial leather is 778 g, thickness is 1.73 mm. Three layers of 0.58 iMM each have a density of 0.33, 0.46 and 0.56 G / 1CM Example 4. Fibrous webs (example 1) are impregnated, as in example 1, with solutions A – C of the following composition, weight. %: Sun Polyurethane12.0 16.0 20.0 Paraffin oil2.0 Water6.0 Dimethylformamide 80.0 Vinylchloride-Copolymers Polyurethane is obtained by converting polybutylene adipate, diphenylmethane-4,4-diisocyanate and butanediol in a ratio of 1: 2.25: 1 25 After processing the impregnated fiber mat to coagulate the polymers without

the use of compression in the finished and body leather obtained the following indicators: weight 1 m 885 g, thickness 2.40 mm. Three layers with a thickness of 0.80 mm have a density of 0.29, 0.36 and 0.45 g / cm.

If the coagulation is carried out by pressure, artificial skin is obtained, the weight of 1 m which is 874 g, the thickness is 1.62 mm. Layers with a thickness of 0.54 mm have a density of 0.41, 0.50 and 0.63 g / cm 3.

Example 5. The fibrous webs with a thickness of 1.85 mm are subjected to a prescription according to example 1 with solutions having the composition specified in example 4. The artificial skin is easily compacted during coagulation and has a thickness of 1.31 mm and a weight of 1 m 687 g. Layers of 0.41 mm each have a density of 0.47, 0.52 and 0.67 g / cm3.

Example 6. A fibrous mat is subjected to an imbalance, “as indicated in Example 1. The solutions sequentially used for this

have a composition as in p-polymer 2. Coagulation of polymers is carried out without compression. Weight of 1 m of artificial leather. And 705 g, thickness 1.31 mm. The layers have a thickness of 0.44 mm each and have a density of 0.48, 0.52, and 0.62 g / cm.

Subject invention

The method of obtaining artificial leather by repeatedly applying to the fibrous canvas layers of a solution in an organic solvent of polyurethane or its mixture with vinyl chloride polymer with increasing concentration from layer to layer, coagulating with a wet method, washing and drying, in order to obtain artificial skin on the ai structure properties close to natural leather, each subsequent layer of the solution is applied to the fibrous canvas after it has completely absorbed the previous layer of the polymer solution.