HU180327B - Method for producing artificial leather having pasted smooth or velourlike surface - Google Patents

Abstract

The invention relates to the production of a nonwoven-based artificial leather having excellent softness and flexibility as well as high moisture absorption capacity and high water and air transport properties. The essence of the invention is that the nonwoven at least partially consists of such fibers impregnated with a hydrophobing agent, such as oils, fats, fatty acid salts, silicones, silicone-containing products and mixtures of these agents, wherein the hydrophobizing agent in an order of 0 , 01% to 5%, preferably 0.1 to 2%, contained in the treated fibers.

Description

The present invention relates to a process for the production of a non-woven base with excellent softness, elasticity and other imitations of genuine leather having properties similar to genuine leather, such as high moisture uptake and high water and burn resistance.

Synthetic leathers or leather substitutes are known. In addition, there are known staple fibers or staple fibers made from synthetic or synthetic fibers or yarns which are impregnated, vulcanized or coagulated, optionally cleaved and coated with known lubricants for use as latexes or plurethanes. These materials are usually less flexible and have poor foldability.

It is also known that the softness and grip of the outer fabric is similar to that of the impregnated base fabric of synthetic leather - the number of bonding points between the different fiber surfaces and the binder used, in other words the bonding ratio of the bondless fiber surface. greater flexibility of yarns in the Vlies belt for bending stress ·

It is also known that the softness and grip of the base meat depends on the edges. The finer the fibers used, the softer the fibers will be.

DE-AS 20 23 214 discloses the production of yarns of 0.1 denier per milliliter per fiber. Vlles and warps made of these fibers

-2180.327 Synthetic leather has excellent softness. In addition to microfine yarns, imitation leather made by the process described in this form also has a number of anchor points. The mlcross bundle contains ui. only the capillary yarns in the outer layer are bonded to the impregnating material, and therefore the capillaries inside the bundle can slip on each other when flexed.

However, the above process for producing high-soft suede leather is too complicated and requires high technical skill. This applies not only to the production of microfine fibers, but also to the subsequent refinement and finishing stages when converting the needle felt into the desired artificial leather.

The purpose of the present invention is to provide a synthetic leather which exhibits a high degree of flexibility, good water absorption and basic water permeability properties of the base fabric inside the synthetic leather. Hydrophobic or partially hydrophobic natural or synthetic fibers, or mixtures thereof, are preferably used as cut fibers, optionally as endless yarns.

FIELD OF THE INVENTION The present invention relates to a process for the production of synthetic leather made from non-wovens of staple fibers, wherein the fibers are disassembled on a carding machine or pneumatic re-forming device, molded, compressed, preferably stapled, optionally shrunken, impregnated with binder, optionally cut, in which case at least a part of the nonwoven comprises a fiber impregnated with a hydrophobising agent.

The proportion of non-microphobic fibers in the nonwoven may be in the range of 5-100%, preferably 5-90%, more preferably 50-70%.

Suitable hydrophobizing agents are all water-repellent products such as oils, fats, fatty acid salts and preferably silicone or silicone containing products. The amount of hydrophobizing agent suitable for the task is determined by the type of agent, e.g. wool, cotton, polyamide, polyacxyl nitrile, polyester, polypropylene, cellulose, etc. and the desired effect of the article in question.

The amount of hydrophobizing agent suitable for the task is generally from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight, based on the hydrophobized fiber material.

A preferred use of a mixture of fibers with different swelling capabilities in accordance with the present invention is to achieve targeted hydrophobation of the fibers.

The process according to the invention is e.g. it is possible to carry out a staple fiber of non-staple or preferably staple fiber having a uniform proportional distribution throughout the non-woven cross-section, as known per se, e.g. prior to impregnation with latex or polyurethane, it is hydrophobised with one of said hydrophobizing agents, preferably by dipping or spraying. Alternatively, all the hydrophobised fibers, or a mixture of hydrophobised and non-hydrophobised fibers, may be used to construct the mesh. .

It is particularly advantageous to use a sandwich-like non-woven fabric as a base non-woven according to the invention.

-3180.327

This vlles may be stapled but preferably stapled. In such a sandwich structure, each layer may comprise fibers of the same type or may consist of fibers of different types. The use of fibers with different swelling capacities is particularly advantageous. In this way, the desired properties of the leather and imitation leather are perfectly suited to the purpose, e.g. in each case, by selecting the type and amount of fibers or fiber mixtures in each layer and positioning the fiber layers relative to one another and by the amount and type of hydrophobizing agent. For example, when making a two-layer staple non-woven fabric, one layer is a mixture of pollamide and the other layer is a mixture of 80% viscose fiber and viscose fiber. This vliest is called so-called. Immersion method is impregnated with a 1% Si-H emulsion. dried and heated briefly to 140 ° C for curing, whereby the water-repellent effect of the polyamide / viscose layer is greater than that of the polyamide layer. Subsequent impregnation with known latexes has a higher affinity of the polyamide layer for the latex than for the viscose layer, but less than for a non-silicon impregnated polyamide web. The base fabric thus obtained is much softer than the base fabric which is not impregnated with silicone and has a higher moisture vapor removal capacity when the polyamide fiber side is lubricated and the viscose layer forms the inner part of the skin.

Vapor vapor oxidation of viscose is not significantly affected by silicone treatment.

For example, hydrofoilizing a three-layer nonwoven so that the most water-permeable layer forms the middle layer of the nonwoven, after impregnation with the latex, produces a base non-woven with a uniform reduction in thickness from the center of both edges of the relay. The base leather and the artificial leather produced from it are extremely soft and eg. when used as a shoe top, it has pleasant wearing properties. By increasing the weight of each layer, in particular the middle layer described, two middle layers corresponding to the two-layer nonwoven fabric of the structure described above are obtained by cleavage of the middle layer.

In a particular embodiment of the process according to the invention, the basic nonwoven is a two-layer nonwovens in which only one of the layers comprises at least partially hydrophobic fibers. The two layers are stapled in such a way that, at least in the last step, the needles penetrate only from the side containing the hydrophobized fibers. The stitching depth is selected by passing fiber beams through a hydrophobic layer opposed to the insertion side to give a velor-like surface after casting and brushing.

The process according to the invention provides a particularly soft and pleasantly felt artificial leather when impregnated with latex binders as described in DE-OS 25 02 654, DE-OS 25 02 655 or DE-OS 26 01 781.

EXAMPLE 1% of% Hydrophobized Polyamide Fiber / Approx. 40 mm filament length, 1 »€> dtex /, 40% polyester fiber / approx. 40 mm strand fiber-4190327, 1.6 dtex / wt urine fiber was impregnated with an abundant latex mixture of the following composition by taking 100 g of solids per 100 g of fiber. The impregnated cloth was then heated suddenly to 50 ° C, thereby gelatinizing the latex mixture. It was then cured with steam at 105 ° C for 30 minutes and then exposed to dry air. Vlles cleavage yielded a microporous synthetic skin stock.

The latex mixture used was of the following composition: 210 sr of a 47% latex copolymer consisting of:

60.0% by weight of butadylene

36.0% w / w acrylic

4.0% by weight of methacrylic acid in a total of 100 sr solids / sr of polydimethylsiloxane in 35% emulsion

1.0 sr polyether ether siloxane

2.0 sr of benzylphenylphenol

75 »O sr water

41.0 sr vulcanization paste consisting of:

sr colloidal sulfur sr cinnamoxide sr clnk-diethyldithiocarbamate sr titanium dioxide sr sodium sodium diisopropylditlocarbamate sr 5% solution of the condensation product of naphthalenesulfonic acid with formaldehyde.

The coagulation temperature of this latex blend is approx. 40 °.

Example 2

A fiber mixture containing 70% of a 1.6 dtex / 40 mm siliconized pollen filament and 30% polyester-big zororodene / 3dtex / 60 mm filament was carded, layered and stitched using a needle 38 following known procedures;

The weight of the fabric is approx. At 350 g / ^z , the firing density was' 750 / c ¹ . The supernatant was then shrunk at 70 ° C. The shrunken shell weighing approx. 450 g / m 2, impregnated with a pollurethane solution after approx. 50% solids were deposited / coagulated, washed and dried.

The polyurethane solution had the following composition, known per se (DE-AS 12 70 276, DE-AS 16 94 171):

- 9 kg of a cationic dispersion of polyurethane, consisting of polyester, phthalic acid and ethylene glycol (molar ratio 1: 1: 2.2), toluene diisoclanate, N-methyl diethanolamine and 1.4 dichlorobutane,

- in a mixture of water-dimethylformamide containing 25% DMF,

- 3 kg polyurethane, which is a hexanediol-polycarboxylic acid ester and 1,4-butanediol adipic acid ester. and a mixture of 4,4-Diphenylmethane diisocyanate and 1,4-butanediol (25% DMF solution),

- 0.5 kg of polyurethane containing butanediol and ethylene glycol mixed with adipic acid ester, 4, ^z- P

-5180.327

1,4— bu.t.1.1 Lead / 25% DM? solution/

0.05 kg of 20% magnesium chloride

- 0,01 kg commercial white tanning agent.

The sealed material was polished, sliced and cca. A white velor-like imitation leather weighing 220 g / π ^{2 was} obtained.

Example 3 A mixture of 1.6% dtex / 40 mm siliconized polyester fiber and 30% polyester high tensile fiber 1.3 dtex / 60 mm fiber was converted to the same procedure as in Example 2 and post-treated with a polyurethane solution.

The velorazer-like imitation leather thus obtained, weighing - 230 g / m *, is significantly harder and less wrinkled than the product of Example 2.

Example 4 A mixture of 1.6% dtex / 40mm siliconized pollamide fiber and 30% polyester high shrinkage 1.3dtex / 60mm fiber was formed, stapled and shrunk as described in Example 2.

Weight of fabric: 450 g / m ^J

Insertion density approx. 8D0 insertion / cn was ¹ .

a / The pre-treated vlleat is impregnated with 23% latex diazers (Perbunan N 3415), with a solids application of approx. 100% by weight of the non-woven material is coagulated in IV space, cured with steam, washed, dried and cured at 140 ° C dry temperature.

The raw material thus obtained is sliced, sanded on both sides, and the velur obtained in this way is dyed by dispersion dyeing according to the known dyeing process. Depending on the thickness of the product, it is suitable for outerwear, upholstery or shoe uppers.

b / The pre-treated wax is prepared with a latex diaper disperser consisting of 23% 5θ% N 3415 perbunan and 50% N latex KA 8194 perbunan, as described in 4a /, with a 100% application of azide solids to the weight of the base material.

The slit and polished material can be dyed with dispersion dyeing, this product is softer to grip and more textile-like than the product manufactured by. Its field of application is outerwear.

Example 5% Siliconized and 20% Non Siliconized / Approx. The azal mixture obtained from 8% residual shrinkage / 1.6 dtex / 40 mm pollamide fiber was converted to the same as in Example 2, impregnated with the latexes mentioned in Example 4, and further processed.

In both cases, the end products are softer than the end products of 4a and 4b, having better strength, breaking strength and fireproofing strength.

Claims (9)

Patent claims CLAIMS 1. A process for producing synthetic leather from staple fibers by disintegrating, laminating, compacting, preferably stitching, optionally shrinking, impregnating, optionally slitting, grinding, beating, combing, combing, or combing pneumatic webbing. wherein the fiber is impregnated with a hydrophobicizing agent for at least a portion of the fabric. 2. A process according to claim 1, wherein the hydrophobized fibers are applied in an amount of 0.01% to 5%, preferably 0.1% to 2%. 5. The process of claim 1 or 2 wherein the hydrophobizing agent is selected from the group consisting of oil, fat, fatty acid salt, silicone, silicone-containing product and mixtures thereof. 4. A method according to any one of claims 1 to 4, characterized in that the nonwoven is formed from a mixture of hydrophobised and hydrophobic lan. 5. A process according to any one of claims 1 to 6, characterized in that the nonwoven is at least partially hydrophobised with a binder prior to impregnation. 6. A method according to any one of claims 1 to 6! characterized in that the weft is formed as a sandwich structure with layers of at least partially hydrophobized fibers. 7. A process according to claim 6, characterized in that only one layer is formed of at least partially hydrophobized fibers. The process according to any one of claims 1 to 7 «! characterized in that the non-woven fabric is formed from two separate non-woven layers, only one of which is formed of at least partially hydrophobized fibers, and that at least in the last step the stitching is performed by stitching the needles on the hydrophobized fiber side; ! and selecting the depth by passing through the ends of the fiber on the non-hydrophobic layer opposite to the insertion side and then creating a velor-like surface by molding and brushing. 9. A method according to any one of claims 1 to 6, characterized in that each layer is made of fibers having different swelling capacities. 10. Method of toothing according to any one of claims 1 to 3, characterized in that the nonwoven is made from 5 to 100%, preferably 5 to 90%, of hydrophobised fibers.