DE1272877B - Process for the production of gas and moisture permeable synthetic leather - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

Number:
File number:
Registration date:
Display day:

D06n

German class: 81-2

P 12 72 877.7-43 (S 92757)

August 21, 1964

July 18, 1968

Numerous processes for the production of gas- and moisture-permeable synthetic leather are known (cf. the article by H. G. S c h w a b e in the journal "Kunststoffe", Vol. 48 [1958], p. 285, with numerous other references; German Auslegeschrift 1103 884, French patent specification 1131453; Article by G. Wick, D. Homann and P. Schmidt in the journal "Kunststoffe", Vol. 49 [1959], pp. 389/390; British patent specification 416; German utility model 1 749 029; German patent application St7019VII / 8h [announced on August 23, 1956]; German Auslegeschriftl096324; German utility model 1,694,051 and British patent specification 850,791).

The known methods can be divided into the following groups:

1. Process for the production of air-permeable artificial leather by incorporating highly porous Fillers in plastic compounds before processing into sheets.

2. Process for the production of gas-permeable or suede-like artificial leather by dissolving it out of previously incorporated soluble substances. This procedure is quite complicated, and it a flexible synthetic leather product is difficult to obtain.

3. Process for the production of foamed artificial leather by applying a propellant containing Plastic layer on a textile substrate and heating of the layer material. The foam layer has an open-cell structure, but forms on the foamed surface that exposed to the atmosphere, a continuous layer of film. Therefore this has conventional Synthetic leather has a structure made of a fabric layer, a foam layer and a Foil layer. The aforementioned film layer enables gas and moisture permeability disturbed, and therefore this conventional artificial leather has practically no or very little low gas and moisture permeability.

4. A method for producing a suede-like artificial leather by grinding a foam cover layer.

5. Process for the production of gas-permeable carrier webs by partial coating of Textile webs with a plastic coating.

Process for the production of gas

and moisture-permeable synthetic leather

Applicant:

Sumitomo Chemical Company, Ltd.,

Osaka (Japan)

Representative:

Dr. V. Vossius, patent attorney,
8000 Munich 23, Siegesstr. 26th

Named as inventor:

Hirosi Tsukamoto, Nishinomiya-shi;

Kazuo Fujimoto, Hirakata-shi (Japan)

Claimed priority:

Japan August 22, 1963 (44 652)

6. Process for the production of artificial leather by applying and gluing a foamed Layer, e.g. B. made of polyvinyl chloride, on a non-porous carrier, e.g. B. a polyvinyl chloride film.

7. Process for the production of plastic-coated Textile webs, in which a plastic powder layer is applied to the textile web and optionally the plastic particles are anchored to the textile web by applying heat and / or pressure.

8. Perforation of foil or synthetic leather strips. In the process, although the holes are Help made by needles, yet the holes close instantly when the needles be pulled out. Large holes must therefore be made to prevent closing will. The holes made by this perforation process are directly connected, and thus the synthetic leather is not waterproof.

9. Treatment of plastic foils and high-frequency discharges using needle-shaped flashover electrodes.

809 570/511

3 4

The methods described above have bonded the fabric layer without the powder layer too one or more disadvantages, and they do not result in a cohesive layer flowing together satisfactory gas and moisture permeable, and without being at the border between powder and "Breathing" synthetic leather. Foam layer pore closures occur.

The invention relates to a method for producing the foamed layer Manufacture of gas and moisture permeable and the sintered top layer at the same time on the Synthetic leather is made by coating fabrics, fiber carrier material, or one is revealed beforehand or paper with pastes based on a sintered layer made of polyvinyl chloride on the carrier or mainly vinyl chloride is removed by placing a holding copolymers or mixtures of this io foamed layer forms.

Polymers that contain an additive of propellants. Synthetic leather with high strength can indeed be used, which is characterized in that it is made by placing a sheet or film with capillary on at least part of the surface of the like openings with a carrier such as Fabric, fabric, fiber fleece or paper applied, a fiber fleece or paper, and glued with the help of a common propellant with a decomposition temperature between 90 15 seeds binding agent. This synthetic leather and paste containing 180 ° C has no gas and moisture permeability, polymers either a powder of the named poly since between the permeable film and the meren, which has formed an adhesive film layer at a temperature below 220 ° C carrier material. According to one embodiment of the method according to the invention, the laminate is heated to a temperature of between 160 and 220 ° C, or a sintered film is applied to the moisture-permeable film layer on the carrier or web of material with the help of a gas and moisture throughden said polymer with capillary openings a permeable layer with continuous open-celled and then bonded the laminate to a structure so that the artificial leather obtained is ^{heated to a temperature between 130 and 200 0} C and completely gas and 25 is moisture permeable. after which the foamed layer has a cavity- In the known process for the production of

Ratio from 0.4 to 0.95 and the sintered layer of artificial leather, in which a foamed layer is made has a void ratio of 0.05 to 0.4. Polyvinyl chloride formed on a textile support

The F i g. 1 to 4 show schematically, in cross section, is formed on the surface of the foamed the structure of the layer according to the invention is a coherent, closed layer, drive manufacturable synthetic leather. In the figures, this largely denotes the gas permeability 1 the sintered top layer, 2 a mixing lorry. In the method according to the invention is a layer, 3 the foamed top layer and 4 the paste with high propellant content used. the Carrier. foamed layer has a high content

F i g. 1 shows an artificial leather in which the coating has open cells. It forms from the powder layer processing paste applied to one side of the carrier material or sintered layer and the blowing agent-containing paste is. On this layer, the powder layer is then a composite layer when foaming applied and the laminate heated; Gas permeability is maintained. At the same time owns

F i g. 2 shows an artificial leather which, according to an assumption, the artificial leather-like product obtained has a high borrowed method as in F i g. 1 is manufactured, 40 strength and a leather-like handle, However, the coating paste is only applied to part of the coating.

applied to the carrier material; paste is made by thoroughly mixing the

F i g. 3 shows an artificial leather in which on one side paste-making suitable polyvinyl chloride, a a carrier material is a gas and moisture permeable mixed polymer, which is mainly made of vinyl-permeable sintered layer with capillary-like opening 45 chloride, or a mixture of these Polymerinungen using a coating paste sate with a plasticizer, a stabilizer and as a binder, which contains a propellant, on a propellant produced at a temperature has been brought, whereupon the laminate heated between 90 and 180 ° C, a large amount of gas was released; splits. If necessary, a pigment is used

F i g. Fig. 4 shows an artificial leather similarly containing 50 filler, an auxiliary blowing agent, a vulcanizing agent as in the explanation of FIG. 3 was made. and slammed fiber material. The gas and moisture permeable sintered coating paste is then applied to the entire

Top layer is, however, with the help of the coating surface or part of the surface of the carrier paste, the only at certain points of the carrier layer fabric with the help of z. B. a doctor blade, reversing roller or was applied, bound to this. 55 Print roller mounted in a certain layer thickness

This brought about by the method according to the invention. You can also use the coating paste on adjustable synthetic leather is "breathing", ie gas and moisture - the entire surface or part of the surface is permeable, it has a superior toughness, a metal plate or heat-resistant paper, flexibility, it is waterproof and very good that has no binding properties, with the help of structure, and in it the smallest cavities, such as a squeegee, reversing roller or pressure roller, are distributed skin pores, and it resembles natural leather and 30 seconds to 2 minutes at 80 to 120 ^° C its properties and its shape. heating, whereby the sol mixture is converted into a semi-solid state. For the production of the artificial leather, the carrier material is then simply and continuously pressed onto this mass and can be carried out for 1 to 10 minutes. 65 heated to 80 to 150 ⁰ C. The received

In a one-step heat process, a three-layer laminate is removed from the base, layered artificial leather is produced, whereby the on- As soon as the coating paste is applied to the carrier material

scattered powder layer with the foamed synthetic is applied, a powdery mixture of the

5 6

Polymers in the manner described below or the nonwoven fabric to the foamed layer very

is uniformly and, if necessary, strongly bound under pressure, and no film is formed,

applied, and a laminate structure is obtained which prevents gas and moisture permeability.

from a carrier layer, one from the coated.

tungspaste formed layer and a powder 5 By using a certain propellant

layer. and in a certain amount for the coating paste

The powder mixture is prepared by mixing and working at a certain temperature see polyvinyl chloride or a mixed poly, the void ratio can be merisat to a value, which consists mainly of vinyl chloride, from 0.95 to 0.40 and the diameter of the cells on or a mixture of these polymers and that you set a value of 50 to 1000 microns,
can pulverize, with at least one plasticizer By changing the cavity ratio and, if necessary, stabilizer, pigment, filler of the diameter of the cells in the specified or fiber-like material, in a belt screw area, the gas and moisture mixer or Henschel mixer can be operated at 60 to 140 ° C, nonchalance, flexibility, toughness, the structure until the mixture is dry. The mixture obtained 15 and similar properties of the artificial leather on one is then z. B. crushed in a jet mill and set the desired value,
sieved through a sieve with an internal mesh size of 0.38 to 0.074 mm used in the coating paste. Propellant is its decomposition temperature of

A powder layer with a certain thickness can be important. If from the propellant gas at a can easily be produced by generating the constant supplied temperature at which the sintering of the Powder with the help of z. B. a squeegee or buffing powder layer takes place, the gas development is planarized dispersed or electrostatically inhibited the powder and worsened the formation of cells, of a certain layer thickness. Accordingly, you have to use a coating paste

The laminate structure obtained is then produced on, at a temperature between 90 and

heated to a temperature between 160 and 220 ° C, 25 180 ⁰ C begins with the foaming. This temperature

wherein the layer formed from the coating paste is about 40 to 7O ⁰ C lower than the lowest

foams and the powder layer sinters at the same time. The temperature at which the sintering takes place,

The resulting foamed layer has an open-cell structure. Any chemical compound can be used as a blowing agent

Structure, and the sintered top layer has capillary willows that use nitrogen in their decomposition

like openings. 30 developed. Examples of the in the invention

When the heating is just carried out so far procedures are preferred propellants used

is that the top of the powder layer opens, ρ, ρ'-Oxybisbenzenesulfonylhydrazid, Azodicarbonamid,

a surface with suede-like Ν, Ν'-dinitrosopentamethylenetetramine, diazoamino-

Appearance. If the heat treatment is carried out by benzene, diphenylsulfone-3,3'-disulfohydrazide, 4,4'-di-

bring flat and porous metal plates to the 35 phenyldisulfonylazid or N, N'-dimethyl-N, N'-di-

Surface of the powder layer is carried out nitrosoterephthalamide.

a shell-like surface is obtained, the production of the sintered top layer with

and when the heat treatment on a porous capillary-like openings made of the synthetic resin powder

Metal plate with an engraved, skin-like pattern is carried out as follows: The sintering is carried out through

is carried out, one obtains a corresponding 40 melting of each powder particle carried out, wherein

patterned skin-like surface. at the same time the powder particles at their point of contact

The foamed layer with open-cell structure is glued together and gaps in is made by forming the coating paste of the powder layer. These spaces lets melt and at the same time from the blowing agent or cavities extend from one side to the generates a large amount of gas. Here, the other side of the sintered layer expands in the form of Mixture with the formation of open cells, the capillaries. By controlling the void ratio the layer are evenly distributed. nisses of the powder layer by selecting the particle if during the heat treatment, the surface of the sol size distribution of the powder and the extent of the mixture layer is not covered by the powder layer, pressure exerted on the powder, as well as forms on its surface, directly associated with the 50 by controlling the conditions of the warm atmosphere is in contact, a continuous treatment in terms of temperature and the Resin layer, which is the inner part of the time, the void ratio can be reduced to one continuous open-cell structure against the value between 0.05 and 0.40 and the diameter Atmosphere. of the capillaries in the sintered layer of some

Even if such a continuous resin change from 55 microns to about 60 microns. By changing

layer when using a large amount of propellant change the void ratio and the diameter

is not formed and the inner part against the knife of the capillaries in the specified area

Atmosphere is not closed, the surface can reduce gas and moisture permeability,

the foam layer is not fine, and you get no water permeability, flexibility, toughness

Leather that meets the usual requirements. If 60 speed, the structure and similar properties of the

on the other hand, the surface of the layer sintered from the coating paste can be set differently. By

formed layer according to the invention by a powder reduction of the void ratio and the

layer is covered, one obtains a gas and a moist diameter of the capillaries can be completely

permeable synthetic leather can be obtained without the above waterproof sintered layer which

mentioned difficulties and disadvantages. 65 but their gas and moisture permeability

Maintains on the contact side of the coating paste. Part of the sintered top layer is with

the fibers are mixed with the woven or non-woven fabric by part of the foamed layer. These

the foamed layer envelops, whereby the tissue layer is briefly referred to as "mixed layer".

When the powder layer and the layer formed from the coating paste stick together under pressure and then heated at atmospheric pressure, the layer formed from the coating paste expands by foaming, and the powder layer shrinks during sintering. Here some of the sintered ones are mixed up Layer with part of the foamed layer to form the mixed layer.

The conventional artificial leather has a structure in which each layer is layered in heels, for Difference in the structure of the synthetic leather that can be produced according to the invention.

The examples illustrate the invention. Unless otherwise stated, parts are by weight is.

example 1

Production of a polyvinyl chloride sol mixture (coating paste)

The following ingredients become a coating paste in a mortar thoroughly for about 40 minutes mixed:

Parts

Polyvinyl chloride for paste 100

Dioctyl phthalate (plasticizer) 80

Dibutyl phthalate (plasticizer) 60.

ρ, ρ'-oxybisbenzenesulfonyl hydrazide (Propellant) 18

Stabilizer based on organic tin compounds containing sulfur 2

Brown pigment 0.2

Making the powder mix

The following ingredients are mixed in a ribbon screw mixer:

Parts

Powderable polyvinyl chloride 100

Dioctyl phthalate (plasticizer) 15

Brown pigment 0.2

The mixture is ^{heated to 120 °} C. until it is dry. The dried mixture is then ground in a jet mill and sieved through a sieve with a mesh size of 0.15 mm. A powder mixture is obtained with a grain size that passes through a sieve with a mesh size of 0.15 mm.

Method according to the invention

On the entire surface of a woven cloth, knitted on both sides, number 30, the coating paste prepared in the manner described above is applied in a thickness of 0.1 mm with the aid of a doctor blade. The powder mixture described above is sprayed onto this layer in an amount of 300 g / m ² and then distributed evenly with a doctor blade. A layered product having a fabric layer, a layer formed from a coating paste and a powder layer is obtained. This laminate is heated for 2 minutes at atmospheric pressure in a circulating hot air oven set at 180 ° C. Here, the sintering and the foaming reaction are carried out at the same time. It is an artificial leather with the in F i g. 1 obtained structure. The surface of this synthetic leather looks like suede. The void ratio of the sintered layer and the foamed layer are 0.25 and 0.85, respectively. The artificial leather obtained has the following properties:

leatherette

Moisture permeability

JIS *) Z 0208 gas permeability

nitrogen

at a pressure of
0.1 kg / cm ²

Kink resistance
after Scott

JIS *) K-6772

Synthetic leather according to the example!

Conventional artificial leather made using the foaming process

*) JIS = Japanese industrial test standard.

more than

400 g / m ² /

24 hours less than

20g / m ² / 24hours 150 cm ³ / cm ²

less than
2.5 cm ³ / cm ²

no change after more than 10000 folds

no change after more than 10000 folds

Example 2

Preparation of a sol mixture (coating paste) A sol mixture is made up of the following components produced in a similar way as in example 1:

Parts

Polyvinyl chloride for paste 100

Dioctyl phthalate (plasticizer) 60

Dibutyl phthalate (plasticizer) 40

Azodicarbonamide (propellant) 5

Stabilizer based on organic tin compounds containing sulfur 2

Black pigment 0.2

Making the powder mix

The following ingredients are in a high speed Mixer thoroughly mixed:

Parts

Polyvinyl chloride for the production of
Powder 100

Staple silk fibers 2 mm in length. 2
Black pigment 0.2

Method according to the invention

The coating paste is applied to kraft paper, the surface of which is modified with a melamine alkyd

Synthetic resin was treated, applied in round spots of 5 mm diameter at equal intervals of 8 mm by the screen printing process. The paper is then heated for about 1 minute in a hot air oven set at 100 ° C. Subsequently, the printed with the coating paste surface of the paper dam with woven and knitted cloth on both sides is no. 30 bonded under light pressure and heated for approximately 3 minutes in a set at 12O ⁰ C hot-air oven. The cloth is peeled off the paper with the coating ^{paste and sprayed evenly in an amount of 300 g / m 2} with the powder mixture and then spread with a knife and then pressed ^{for about 10 seconds at a pressure of 10 kg / cm 2.}

μ / on the obtained laminate, an aluminum metal plate, the small holes having placed and heated for 4 minutes in a Umwälzheißluftofen, which is set at 18O ⁰ C. A clamshell-like artificial leather of the type shown in FIG. 2, which has numerous small pores on its surface that look like small holes. The void ratio of the sintered layer is 0.20, the moisture permeability is more than 400 g / m ^2/24 hours and the gas permeability of more than 250 cm ³ / cm ² with nitrogen at a pressure of 0.1 kg / cm ^2. The synthetic leather can be bent more than 1000 times according to Scott without changing the flexural strength.

Example 3

A plastisol composed of 100 parts of polyvinyl chloride, 120 parts of plasticizer, 16 parts of ρ, ρ'-oxybisbenzenesulfonylhydrazide and 2 parts of a stabilizer based on a sulfur-containing organic tin compound is thinly spread over the entire surface of a No. 30 woven cloth, and a gas-permeable sheet is placed thereon obtained by sintering pulverizable polyvinyl chloride. The laminate is heated for 2 minutes at atmospheric pressure at 16O ⁰ C. The sintered layer has a void ratio of 0.25, a pore diameter of 10 microns and a thickness of 0.5 mm and a suede-like surface. The artificial leather has the in FIG. 3 cross-sectional structure shown. In Fig. 3 denotes 1 a layer with capillary-like cavities, 3 the foam layer and 4 the layer made of the woven cloth. The synthetic leather obtained had a gas permeability (air at a pressure of 0.1 kg / cm ² ) of 130 cm ³ / cm ² , and after buckling more than 2000 times according to Scott (test standard JIS K-6772), there was no change in the flexural strength.

Example 4

55

A plastisol similar to that obtained in Example 3 is spread on a woven cloth in point form, and the sintered film described in Example 3 with skin-like embossing on the surface is applied thereon. The laminate is then heat treated at 160 ° C for minutes. An artificial leather with a skin pattern and the one in FIG. 4 cross-sectional structure shown. The gas permeability (air at 0.1 kg / cm ² ) is 170 cm ³ / cm ² , and the flexural strength shows no change even after Scott buckles more than 2000 times.

Claims (2)

Patent claims: 1. A process for the production of gas- and moisture-permeable synthetic leather by coating fabrics, nonwovens or paper with pastes based on polyvinyl chloride or mainly vinyl chloride-containing copolymers or mixtures of these polymers which contain an additive of propellant, characterized in that the at least a portion of the surface of the fabric, nonwoven fabric or paper applied, a blowing agent having a decomposition temperature between 90 and 18O ⁰ C containing paste on the basis of the polymers mentioned, either a powder of said polymer which are sintered at a temperature below 220 ⁰ C. can uniformly applied, followed by heating the laminate to a temperature between 160 and 22O ⁰ C or applying to the applied paste, a sintered film or sheet of the aforementioned polymers with capillary openings and then the laminate to a temperature between 1 30 and 200 ⁰ C and after which the foamed layer has a void ratio of 0.4 to 0.95 and the sintered layer has a void ratio of 0.05 to 0.4. 2. The method according to claim 1, characterized in that pastes are applied as blowing agents ρ, ρ'-oxybisbenzenesulfonylhydrazide, azodicarbonamide, N, N '- dinitrosopentamethylenetetramine, diazoaminobenzene, diphenylsulfone-3,3'-disulfohydrazide, 4,4'-diphenyldisulfonyl azide or N, N '- dimethyl - Ν, Ν' - dinitrosoterephthalamide contain. Considered publications: German Auslegeschriften No. 1103 884,1096 324; German Auslegeschrift St 7019 (published on August 23, 1956); German utility model No. 1 694 051, 1 749 029; French Patent No. 1131453;
British Patent Nos. 833,416, 850,791;
"Kunststoffe", 1958, pp. 285/286; 1959, pp. 389/390. 1 sheet of drawings 809 570/511 7.68 © Bundesdruckerei Berlin