DE1288061B - - Google Patents

Description

1 2

The invention relates to the production of stages, namely an impregnation of the fibers with

porous synthetic leather. Latex, a coagulation of latex under heating,

It is a method of making porous a squeezing off part of the water and only Artificial leather known, in which a natural subsequent drying of the squeezed-off material or synthetic textile fibers existing fiber materials are worked, a product is coated or fiber mat with a binding agent of special quality, which is characterized by high elasticity, impregnated and dried and the thus produced uniform strength and uniform and controlled drying The base has one or more overbearing porosities.

Tension layers made of plastic is provided. When using the method according to the coating layers, the impregnated fiber layer or fiber layer with a content of plasticizer and given mat can therefore be obtained in the form of a solution, according to the invention, a great uniformity throughout a paste or a dispersion on a synthetic resin base by suppressing the casein if applied. The coating layer migration of the latex to the surface of the impregnation may then be subjected to a heat treatment, e.g. B. a gnated fiber layer not only a possible separation hot calenders are subjected. As a binder 15 of the layers of the artificial leather, but also the slope for the textile fibers in the underlay, latex can be prevented from forming undesirable wrinkles.
Natural or synthetic rubber can be used. Although a method has already been described, it can be used. after which a migration of the latex particles in the fleece

In the case of documents made with natural and / or by very long lasting, at low temperatures Textile fibers bonded to synthetic latex consist, 20 occurring coagulation with simultaneous drying special problems arise. Which after the known should be avoided. Another procedure aren Process-made products were not processed in the case of plastic dispersions with a pre-uniformity porous and also often showed coagulation and final coagulation Risk of splitting. the drying, whereby the precoagulation a

The object of the invention is to create a precipitation and fixation of a part of the latex particles

improved process for the production of artificial leather, and thereby a migration of the latex

which is characterized by a particular homogeneity of the porosity particles in the subsequent post-coagulation stage, in

did excel and at which no risk of any of the at the same time expelling the water by heat

Splitting is present. and the material is dried, prevented or

The method according to the invention for production is intended to be at least made more difficult.

of porous synthetic leather with a backing apart from the difficulties in terms of

natural or synthetic, with natural the handling of such partially coagulated nonwovens occurs

and / or synthetic latex agglomerated textile - unwanted sticking and hardening of the

fibers, on which one or more coating layers fleece, since in both cases the entire water content

Made of plasticized plastic, the given 35 latex or synthetic resin dispersion by heat

if casein and / or fillers, pigments, have to be evaporated and the relatively long

Adhesion promoters and stabilizers also contain the latex particles, as long as they are exposed to high temperatures

have been brought, is characterized by the fact that they soften and flow together,

one first a fiber layer or a fiber mat In contrast, according to the method according to

impregnated with the latex, the latex in the impregnation 40 invention in the coagulation stage a complete

gnosed fiber layer or fiber mat carried out by precipitation of the latex, with the proviso,

warm coagulates * with only part of the water that only part of the water content of the latex

allowed to evaporate, then the impregnated, heat-evaporated. This means that no or only one

acted fiber layer or fiber mat so far by very little migration of the precipitated latex particles

Squeezing dehydrated, that they still take place 20 to 50 ° / ₀ 45 with the water migrating in the heat.

Contains water, find the squeezed off material on it. As a result of the complete coagulation, the

dries and the coating layer or layers of latex particles also immediately and to a large extent

applies in a manner known per se. fixed to the fibers of the fleece. During the subsequent

The invention is based on the knowledge that when the larger amount of water is mechanically squeezed off at the same time as the coagulation, a proportion that occurs or that occurs at significantly lower temperatures Immediately subsequent heat drying at a latex temperature than the drying temperature does not take place impregnated fiber layer or fiber mat a substantial shift of the latex particles instead of that of the rubber particles is preferably used as the surface takes place, whereby an impoverishment of the inner mechanical strength of the not yet dried Layers of the base; due to rubber particles, the non-woven fabric is considerably increased and its further handling is that relieves the danger of a lack of internal connectivity. During the later drying process is a split or a split. In addition, the dry content of the fleece is already so high a disadvantageous accumulation of the rubber particles increases and the latex particles are so strongly fixed that on the surface of the impregnated fiber layer these can no longer migrate even in the heat, or fiber mat instead, which leads to an undesirable 60 Since, moreover, a considerable part of the water already Compaction of the surface layer and one inhomo- is removed, the drying times and thus the genes porosity leads. The wandering of the rubber temperature stresses compared to the ones involved before in the known mode of operation, the procedure out of writing is significantly reduced. That so which a reduction in elasticity and an un- preserved, very uniform material is not uniform Strength of the impregnated fiber 65 sticks or hardens, but it has excellent layer or fiber mat. Firm up, it remains softer and more pliable

If, however, according to the invention in the intended and less prone to wrinkling and it shows extra-

four interrelated essential treatments that ensure excellent and uniform porosity.

The method according to the invention is explained in more detail below with reference to a few exemplary embodiments explained.

It is first a layer of fibers or a continuous mat of natural or synthetic Fibers, optionally from waste fibers, by superimposing several carded nonwovens or on a "curlator" machine.

The fiber layer or fiber mat is then immersed in a bath which has approximately the following composition Has:

position of polyacrylic acid or methacrylic acid esters or of polyvinyl halides. It can too Mixtures of these substances are used. A latex of natural and / or synthetic rubber can be added.

A particularly advantageous preparation for the production of the coating is the following:

Components Parts by weight Latex made from natural or synthetic rubber (approx
60%)> based on dry matter 100

Zinc oxide 3 to 5

Sulfur 1.5 to 2.5

Accelerator 1

Antioxidants 1 to 2

Fillers (kaolin, lithopone, ben-

tonite, calcium carbonate) ...: ... 0 to 100

Stabilizers 3 to 5

Wetting agent 2 to 10

Water 500 to 2000

The impregnated fiber layer or fiber mat is passed through an oven which is at a temperature of 200 to 300 ^° C. in order to bring about coagulation of the latex. Dielectric heating can also be used. The impregnated fiber layer or fiber mat should be passed through the oven in such a way that the latex can coagulate at about 60 to 80.degree. Some of the water evaporates in the process.

The still wet fiber layer or fiber mat containing rubber as a binder for the fibers, is then dewatered by pressing or by treatment with nip rollers, and preferably dried at a maximum of 120 ⁰ C.

According to the invention it is essential that the impregnated, heat-treated and dewatered fiber layer or fiber mat still contains 20 to 50% water, so that the water droplets during drying Leave behind pores that give the product the desired porosity.

After drying, the material is provided with a coating in a manner known per se, wherein Coating agents can be used that include casein, plasticizers, pigments, fillers, etc. and besides Resin elastomers included. Such additives can, for. B. the adhesion, the wear resistance and the aging of the coatings can be improved. These coatings are made by means of any appropriate device, for example by means of a spray gun, by means of a brush or by application applied by means of a doctor knife.

The plasticizers can be made from sulfonated castor oil, glycerine, dibutyl phthalate or the like Mixtures of these substances exist.

Iron oxides, ocher or cadmium sulfide, for example, can be used as pigments, while the fillers can consist of titanium dioxide, lithopone, barium sulfate, kaolin or bentonite.

The elastomers contained in the coating agent can be those based on copolymers, such as those made of acrylonitrile and butadiene or butadiene and styrene, or those based on

Components parts by weight

Elastomer 100

Casein (15% ammoniacal

Solution) 15 to 100

Fillers 25 to 100

Pigments 10 to 20

Zinc stearate 10 to 200

sulfonated castor oil 25 to 50

Water 150 to 600

Wetting agent (on water) 0.2 to 0.5

Glycerin 10 to 25

Dibutyl phthalate 20 to 35

There can be one layer or several one on top of the other Layers are applied, the top layers not having a wetting agent and decreasing May contain amounts of plasticizer. Each layer can be dried before the next Layer is applied.

A further layer can then be applied to this coating

can be applied using a preparation which has the following composition:

Components parts by weight

Casein (in 15% solution) 100

Elastomer 50

Plasticizers 25 to 60

Antiseptic (e.g. formaldehyde
40 ° / ₀ ig) 2% on the total weight

Water as necessary to obtain the appropriate viscosity

After this coating has dried, a second layer can be applied which contains 15 to 20% formaldehyde (40%). This layer is dried with hot air of 50 to 80 ⁰ C and by contact with a polished metal plate that has a temperature of 70 to 8O ⁰ C, for 5 seconds smoothed under a pressure of 25 to 50 kg / cm ^2.

For certain applications, an excellent result is obtained by having a part the fillers are replaced by zinc stearate, which when this happens will result in those produced in this way Objects are given a natural sheen that is difficult to distinguish from that of natural leather is. It can 10 to 200 parts and preferably 50 to 200 parts of zinc stearate, based on 100 Parts of elastomer are added, and then those of lithopone, titanium dioxide, barium chloride can be added fillers formed etc. are omitted.

On the other hand, products can be obtained which improve the appearance and the performance properties of natural leather as well as the desired porosity

sit by per se known coatings of polyvinyl chloride in place of those described above Layers are applied. The degree of porosity that can be achieved depends on the amount of

Claims (4)

5 6 applied coating compound as well as their joint claims
composition. For example, the above-described 1. Process for the production of porous Wise impregnated, heat-treated, drained artificial leather with a base made of natural and dried fiber layers or fiber mats 5 synthetic, with natural and / or synthetic a coating of 70 to 300 g / m ² by using table latex agglomerated textile fibers on which a preparation obtained, which the following additional one or more coating layers of soft- composition may have: machinist plastic, which if necessary additional casein and / or fillers, pigments, Ingredients parts by weight ok containing adhesion promoters and stabilizers, Polyvinyl chloride 55 to 62 have been brought, thereby marked Dioctyl phthalate 12 to 16 ζ e i c h η e t that you first have a fiber layer Dioctyl adipate 12 to 16 o ^{of a} fiber mat impregnated with the latex, Epoxy resin (as plaslilizicruiigs- t.ulex ^{in the} impregnated fiber layer or and stabilizers) 1 to 3 ¹ S fiber mat coagulated by heating, with only Fillers 0 to 12 ^em part of the water is allowed to evaporate, then the Pigments 1 to 4 impregnated, heat-treated fiber layer or Cadmium barium laurate fiber mat is dehydrated by squeezing (Stabilizing agent) 0.25 to 0.75 ^{that it still contains 20 to 5O} 7o water, then ao the squeezed-off material dries and the excess After the coating has been applied, it becomes known per se in the pulling layer or layers Usually applied at 170 ° C for 2 to 5 minutes. gels and can then be embossed. 2. The method according to claim 1, characterized It is also possible to draw on this polyvinyl chloride that the latex in the impregnated coating one or more additional layers on to-05 fiber layer or fiber mat at 60 to 8O ⁰ C. bring which the porosity is coagulated to a desired one. Decrease or suppress degrees if this is considered 3. The method according to claim 1 or 2, thereby considered necessary. in that the impregnated and dewatered by the results obtained according to the invention products squeezing fiber layer or fiber porous bodies of high quality artificial leather, which fall matte 30 is dried at a maximum of 120 ⁰ C,
are suitable for numerous purposes, both 4. The method according to any one of claims 1 to 3, for example for shoe materials, such as upper leather, characterized in that for the intermediate lining, Insoles or caps, an aqueous preparation is used for the upholstery layer, goods, bags, filters and other uses containing zinc stearate in an amount of 50 to 200 where natural leather is otherwise used. Contains 35 parts per 100 parts of polymer elastomer.