RU2794507C1 - Method for manufacturing artificial leather - Google Patents

Abstract

FIELD: leather.

SUBSTANCE: invention relates to methods for manufacturing artificial leathers produced by applying high-molecular substances, in particular cellulose derivatives, onto a fibrous or woven base. Method for manufacturing artificial leather includes the operations of producing and applying a nitrate cellulose primer onto a dyed cotton fabric treated with a finishing agent, characterised by adding a 30% wt. solution of a butyl methacrylate copolymer in ethyl acetate with methacrylic acid BMC-5, a plasticiser – dioctyl phthalate, fillers, and pigments to a primer based on 22% wt. nitromastic, wherein the fabric is treated with a finishing agent at the final stage of dyeing by impregnating in a 25% wt. aqueous dispersion of a styrene copolymer with acrylic monomers of the A10 brand at 40 °C for 10 minutes.

EFFECT: advanced method for manufacturing artificial leather with a nitrate cellulose coating by modifying a nitrate cellulose primer and by using a synthetic high-molecular weight finishing agent exhibiting high affinity for the fabric and the nitrate cellulose primer ensures high adhesion of the applied nitrate cellulose primer to the fabric base, improves strain and strength performance, and prolongs the durability of artificial leather.

2 cl, 1 ex

Description

The claimed invention relates to methods for the production of artificial leather obtained by applying high molecular weight substances to a fibrous base, for example, resins, rubbers, cellulose derivatives.

Such materials are used as decorative finishing coatings in construction, in the automotive industry and other areas of technology. They are widely used in the printing industry for binding books, albums, notebooks and special types of printed products, which greatly increases the performance of products and improves their appearance.

Technological solutions known in the field of artificial leather production are based on the application of cellulose nitrate primers of various compositions to previously prepared dyed and dressed cotton fabrics. To give the fabric the properties of natural leather, the primer is made up of nitromastics, plasticizers, pigments, fillers and technological additives [1].

The closest technical solution to the claimed method is the technology for obtaining artificial skin on a fabric basis with a nitrocellulose coating [2], which includes the following operations:

1. Preparing the fabric - cleaning, dyeing, dressing, expanding, drying and ironing. These operations are performed on production lines. Dyeing of cotton fabrics is carried out with direct dyes,

and dressing - with an aqueous solution of potato starch containing chalk, kaolin and soda ash. The composition of the dressing, wt. hours:

- starch 11.00 - alizarin oil 0.20 - soda ash 0.03 water 100.00

2. Preparation of cellulose nitrate primer - finishing (colorful).

Recipe for cellulose nitrate soil, wt. hours:

- nitromastic containing 22% cellulose nitrate "colloxilin" (GOST 3864-75) 100.0 - Castor oil 19.8 - oxidized castor oil 8.3 - pigments and fillers 24.2 - solvent (mixture of ethyl acetate and ethanol in a ratio of 65:35) 16.3

3. Priming (priming) and drying.

4. Embossing of a small relief pattern (surface finish of the fabric).

The finished nitrocellulose-coated fabric is embossed on two-roll and three-roll calenders.

All operations are carried out on units that include unwinding and winding devices, priming machines, mainly of the squeegee type, as well as drying chambers.

In known methods for the production of artificial leather, the quality of the finished product is determined mainly by the composition of the cellulose nitrate primer applied to the fabric and the composition of the sizing for the fabric [3]. At the same time, the properties of cellulose nitrate itself, due to its physicochemical properties, do not always ensure the achievement of the required deformation and strength characteristics of artificial leather. In some cases, as a result of strong kinks in the artificial leather, cracks in the coating occur. In addition, the use of a starch composition for sizing fabric leads to a decrease in the adhesion of cellulose nitrate primer to the fabric base of artificial leather. These comments reduce the quality of products, their performance and durability. The objective of the present invention is to improve the method of manufacturing fabric-based artificial leather with cellulose nitrate coating by modifying the composition of the cellulose nitrate primer, as well as changing the fabric sizing process and using a new type of sizing that has a high affinity for fabric and cellulose nitrate primer.

The solution of the above problem is achieved by introducing a copolymer of butyl methacrylate with methacrylic acid of the BMK-5 brand in the form of a 30% solution in ethyl acetate at the rate of 40 wt. hours of copolymer solution per 100 wt. including 22% cellulose nitrate mastic with the following content of ingredients, wt. hours:

- nitromastic containing 22% cellulose nitrate "colloxilin" (GOST 3864-75) 100.0 - plasticizer (dioctyl phthalate) 30.0 - fillers 10.0 - pigments 15.0 - BMK-5 copolymer 12.0 - solvent (ethyl acetate) 28.0

The choice of the BMK-5 copolymer as a modifying additive is explained by the fact that it has a solubility parameter close to that of nitrocellulose, and this ensures their good combination over a wide range. The BMK-5 copolymer gives elasticity to the cellulose nitrate coating of the fabric, improves the organoleptic perception of the material, and makes it possible to use dioctyl phthalate (DOP) as a plasticizer instead of castor oil. DOP, being an intermolecular and interstructural plasticizer, allows you to control the rheological characteristics of the cellulose nitrate composition, which contributes to the formation of a high-quality coating on the fabric.

In addition to modifying the cellulose nitrate composition, at the final stage of fabric dyeing (washing in warm water), it is finished by impregnating it with a 25% aqueous dispersion of a styrene copolymer with acrylic monomers for 10 minutes at a temperature of 40°C.

The content of acrylic copolymers in cellulose nitrate primer and fabric ensures their strong connection after the completion of the entire technological cycle.

A comparative analysis of the proposed technical solution with the prototype shows that the method differs from the known one in that acrylic copolymer is introduced into the cellulose nitrate primer in the form of a solution in an organic solvent, and an aqueous dispersion of acrylic copolymer is used to finish the fabric. Thus, high adhesion of the applied cellulose nitrate primer to the fabric base of artificial leather is ensured, the deformation-strength performance is improved, and the durability of use is increased.

An additional difference is that an aqueous dispersion of an acrylic copolymer is used as a fabric sizing instead of a starch primer. Such a replacement greatly simplifies the dressing operation itself, as it allows it to be combined with the fabric dyeing process.

Example.

The proposed method for manufacturing fabric-based artificial leather with cellulose nitrate coating, which is intended for use as a binding material in the field of printing, is implemented as follows. The first step of the method is the selection and preparation of the fabric.

For the manufacture of artificial leather, which is intended for use as a binding material, a plain weave cotton fabric 0.16 mm thick with a warp to weft density of 21 × 21 (number of threads per 1 cm) was selected. The selected fabric was cleaned in a shearing-cleaning machine on both sides. The cleaned fabric was dyed in a two roll padding. The dye solution heated to 85-95°C contained 5% (by weight of fabric) Bordeaux direct dye, 2% surfactant OP-10 and alizarin oil, 3% soda ash. Sodium chloride was added to the solution in an amount of 10% by weight of the tissue. Next, the dyed fabric was pressed between padding rollers, washed in warm water, and finalized by impregnating with a 25% aqueous dispersion of a copolymer of styrene with acrylic monomers of grade A10 (Forsit, Finland) at a temperature of 40°C for 10 minutes. After that, the fabric was pressed again in the padding and sent to the drying-expanding frames, where possible wrinkles are eliminated and the dimensions of the fabric (surface structure) of the dyed and, thus, finished fabric are fixed.

After the drying process, the fabric was ironed by passing it through the nip of a three-roll ironing calender.

Cellulose nitrate primer was applied to the thus treated fabric.

Recipe for cellulose nitrate soil, wt.h.:

- nitromastic containing 22% cellulose nitrate "colloxilin" (GOST 3864-75) 100.0 - dioctyl phthalate 30.0 - lithopone 10.0 - technical chalk 3.0 - scarlet pigment 1.5 - kraplak 5.0 - iron minium 5.0 - BMK-5 copolymer 12.0 - solvent (ethyl acetate) 28.0

The imposition of soil on the fabric was carried out in the unit, which includes priming machines of the squeegee type and drying chambers. The thickness of the coating was adjusted by setting the required clearance between the doctor blade and the fabric. In this case, the thickness of the cellulose nitrate coating should be 0.2 mm. After completion of the drying process, the cellulose nitrate-coated material was embossed on a two-roll calender (top roll - metal, bottom - paper) at a temperature of a metal roll with a relief pattern of 60-70°C.

Embossing is the final operation and is performed to give the nitro-coated fabric a leather-like surface condition.

The use of the proposed method for manufacturing artificial leather provides the following advantages in comparison with existing methods:

- the possibility of obtaining a fabric-based material with high deformation-strength properties of cellulose nitrate coating;

- reliable connection of fabric and cellulose nitrate coating, which guarantees the achievement of high performance characteristics of materials;

- simplifies the process of finishing the fabric and allows you to exclude the use of a food product - starch from the technological cycle.

List of literature sources used

1. F.B. Klupt. Production of new types of binding materials. Moscow. Publishing House "Forest Industry". 1964; B.N. Shakhkeldyan, L.A. Zagarinskaya. Printing materials. Moscow. Publishing house "Book". 1988

2. M.S. Monastyrskaya, T.P. Shvetsov. Technology of polymer film materials and artificial leather. Moscow, "Light industry", - 1974

3. Sukhareva L.A., Kipnis Yu.B. Protective polymer coatings in the production of artificial leather. - M.,: Chemistry, 1989, p. 256.

Claims (3)

1. A method for the manufacture of artificial leather, including the operations of preparing and applying cellulose nitrate primer to dyed and dressed cotton fabric, characterized in that a 30 wt.% solution in ethyl acetate of a copolymer of butyl methacrylate with methacrylic acid BMK-5 is introduced into the primer based on 22 wt.% nitromastic , plasticizer-dioctyl phthalate, fillers, pigments, at the following ratio of ingredients of the soil composition, wt.h.: nitromastic containing 22 wt.% cellulose nitrate "coloxylin" 100.0 plasticizer-dioctyl phthalate 30.0 fillers 10.0 pigments 15.0 copolymer BMK-5 12.0 solvent-ethyl acetate 28.0 2. A method for manufacturing artificial leather according to claim 1, characterized in that the finishing of the fabric is carried out at the final stage of its dyeing by impregnation in a 25 wt.% aqueous dispersion of a copolymer of styrene with acrylic monomers of grade A10 at a temperature of 40 ° C for 10 minutes.