DE1803021B - - Google Patents

Description

I 2

The invention relates to a method of wise (2) suffers from the difficulty of a great deal Manufacture of vapor-permeable, microporous restricted area in proportion to the addition of the Coatings on fibrous substrates or on microporous ones for the preparation of the colloidal dispersion Foils. applying non-solvent and includes as well

There are a number of operations for the 5 an unstable process operation, as they oppose Manufacture of vapor-permeable, microporous room temperature and moisture very sensitive Synthetic leathers or polymer films with good water resistance. The mode of operation (3) comprises a technical one vapor permeability, d. H. good exudation difficulty both in terms of separation and Ventilation behavior, known as art as well as coating stages, and suffers from poor leather material for shoe upper leather, clothing or io polymer yields. The mode of operation (4) has Gloves should be used. also the disadvantage of a longer period of time,

One of the particularly suitable processes for the coagulation due to the application of such an artificial leather, which has a bath with a content of highly concentrated, highly vapor-permeable polymer film, solvents in which the polymer is hardly the so-called "wet coagulation process", at 15 is coagulable, is required, whereby a bad film-forming polymer solution is applied to a production scale or an enlargement of the carrier material and the coated length of the bath is conditioned, which from an economic point of view are then soaked or soaked in a bath less attractive,
that contains a liquid that neither the object of the invention is to create a carrier material nor the polymer solves, but with 20 effective and novel method for obtaining the solvent in the polymer solution is miscible from highly vapor-permeable, microporous films, whereby the polymer coagulates will. These or foils, which are very similar to natural leather, work method, however, suffers from the disadvantage that in which the disadvantages described above, which often lead to the generation of rough and large previous work methods, full voids in the film, which in turn leads to the 25 consistently avoided, resulting in fairly pinhole formation with little film or fold device without the occurrence of any film strength. In order to avoid the pre- reduction of the performance or the necessary disadvantage and to improve the steam maneuverability for a strict conditioning of the permeability and the microporous structure in the atmosphere is used,
the wet coagulation process have already been used. The subject of the invention is a process for different working methods for the production of a film the microporous films are exposed to moist air and coagulated by applying a solution of carrier material after coating with a poly of a polymer in an organic solvent, merisate solution, which optionally includes the addition of a non-washing solution which is at least partially miscible with a non-solvent removes and dries (German solvent for the polymer in an amount, Legeschrift 1 110 607); (2) a process in which the is so low that no gel formation is brought about, a polymer solution with a nonsolvent contains, is mixed on a fibrous substrate or on medium, which with the solution up to such an impermeable carrier material, Coagulation is miscible to the extent that the polymer solution does not suffer from polymer by treatment in a bath of gel formation, but a colloidal dispersion does not dissolve the polymer and forms with the organic, whereupon the mixture obtained is applied to the carrier see solvent-miscible nonsolvent material and then the material removing the solvent and drying the product soaked and coagulated with a nonsolvent as well as, in the case of use, (US Pat. No. 3,100,721); (3) a working of an impermeable carrier material, stripping wise, in which a relatively large of the formed coating of the same, which is characterized by the amount of a non-solvent of a polymer, that one admixes to the surface of the solution, thereby the solution in to separate one in the form of the solution of the polymer on the carrier gel part and a liquid part, then 50 material or the base applied coating covers the carrier material with the gel part and first to concentrate the outer layer then in a nonsolvent bath, the coating solution soaks a gas stream of a compared to (USA.-Patent 3 190 766), and (4) a working of the polymer solution inactive gas with a manner in which the carrier material is coated with a polymer solution in a 55 m / sec at a flow rate of 1 to 50 m / sec can act, the polymer still in a mixture of a solvent mittel and a coagulated state remains, and only then the nonsolvent for the polymer-containing polymer is coagulated in a known manner. This bath soaks (U.S. Patent 3,208,875). is the duration of the action of the inactive

These modes of operation are to some extent for gas longer than 5 seconds. According to this procedure

the achievement of microporous films or sheets 60 becomes a film with a high vapor permeability

effective, however, every method has received prak- ing.

table application the following It is thus a polymer solution first Disadvantage. For example, the working method (1) requires a carrier material, for example made of woven fabrics, a knitted or crocheted fabric, non-woven cloth, precisely conditioned with regard to moisture, Atmosphere and also a longer period of time 65 paper, plastic films, metal foils or the like., Auffür the execution of the suspension, thereby bringing the, on which the resulting support material with Process control becomes quite complicated and one of the gas flow having kinetic energy poor productivity is obtained. The working an appropriate wind pressure, flow magnitude and

Contact angle is brought into contact before soaking or soaking in a bath, that contains a nonsolvent, the at least is partially miscible with the solvent contained in the polymer solution, but the polymer material does not dissolve, and then the polymer is formed with the formation of a highly vapor-permeable film coagulated in a known manner.

The gas to be used in practicing the invention is expedient from dust-free air, but other gases such. B. nitrogen or carbon dioxide, the opposite of the polymer solution are inactive, either alone or in the form of a mixture for use be able. The kinetic energy can be added to the gas flow according to customary, known working methods can be issued, for example by using various types of gas compressors, fans or the like, and the gas, which has kinetic energy in this way, is then used as a coating applied solution either as an open gas stream or as a restricted or enclosed gas stream after passing through a nozzle or through nozzles of various shapes. the Wind pressure and the speed or extent of the flow can be determined by the wind speed or by wind hours. According to the method according to the invention, the one to be applied Gas speed more than 1 m / sec. The upper limit generally depends on the Viscosity of the solution to be applied and the varying influence on the surface smoothness. However, a gas velocity of usually up to 50 m / sec. without significant impairment the surface smoothness can be applied. The gas flow is allowed to act so long that when the Coating solution is then soaked in the nonsolvent for the polymer, a dense a gelled layer is formed on the surface of the coating solution; d. i.e., the current is turned off during a Periods of at least 5 seconds, preferably more than 10 seconds, are generally maintained.

ίο If the moisture content in the gas, i.e. H. the Humidity, being relatively high, the duration of the application of the gas stream can be longer or longer can be shortened less, but with a sufficient effect when using drying gas can be granted. Therefore, when practicing the method according to FIG the invention is of lesser importance.

The temperature of the gas and the coated solution is preferably not too high, since a high temperature promotes the rate of dispersion of the solvent molecules in the solution, as can be seen from the microporous formation mechanism explained in more detail below. In this regard, it is generally advantageous and desirable that the temperature is not higher than 5O ⁰ C, preferably not higher than 30 ° C.

The conditions under which the gas flow is applied can be within an optimal range Range depending on the type or composition of the polymer in the film image to be used imgs solution can be chosen. Preferred conditions of the gas flow with respect to given solutions are listed in Table 1 below.

Table I.
Conditions of the gas flow in relation to the composition of the coatings

Type of polyurethane ( Polyethylene propylene adipate / Solution
medium Conc
tration Additions ⁷ ) Tempe
rature Humidity
air Stream
mnngs-
quick win To whom-
manic
7FMt MDl ^ / ethylenediamine
(molar reaction (Weight age Z.V1I ratio 2: 3: 0.88) percent) (Parts by weight) ("C) (Before. F.) (m / sec.) (Sec.) DMF ² ) 33 15 to 35 10 to 85 4 to 30 5 to 180 DMF ² ) 33 PVC ³ ) 20 18 to 30 0 to 45 10 to 15 lO to 35 Polycaprolactone / TD ι ») / DOP ⁴ ) 15 Hydrazine DMF ² ) 33 PVC ³ ) 30
ΠΛϋ4ι ~ ΗΛ 10 to 25 0 to 60 2 to 10 5 to 40 Polycaprolactone / TDI ⁵ ) _; / UUr) TO Hydrazine DMF ² ) 33 Soot 10 15 to 33 15 to 90 2 to 40 5 to 28 DMF ² ) 33 Soot 30 15 to 33 15 to 90 2 to 5 lO to 30 DMA ⁶ ) 25th - 20 to 35 0 to 55 2 to 8 5 to 40 DMA ⁶ ) 25th Calcium 15 to 35 0 to 55 2 to 8 5 to 180 carbonate15

') MDI: diphenylmethane-4,4'-diisocyanate.

² ) DMF: dimethylformamide.

³ ) PVC: polyvinyl chloride.

⁴ ) DOP: dioctyl phthalate.

^) TDI: tolylene diisocyanate.
'■) DMA: dimethylacetamide.
') ie 100 parts of polyurethane.

The polymer solution, which in this way is incapable of dissolving the polymer material, Was subjected to kinetic energy of the gas flow, 65 soaked in order to thereby coagulate the polymer, is then placed in a bath of a nonsolvent, whereupon the solvent is removed and allowed to form at least partially in the solution in the polymer of a vapor-permeable microporous film contained solvent is soluble, but dries. As the conditions for the gas flow

5 6

not as severe as in the known method, however, in general a concentration of was required to be regulated, provided that it gave more than 5% satisfactory results. the within the range given above, proportion or the ratio of the addition of behaves the procedural regulation or various additions may be twice the weight -control in much simpler and easier 5 of the polymer do not exceed, as on the other hand Way than in the known working methods carried out unfavorable results, z. B. Humiliation in the will. mechanical properties and roughening of the

Some additional treatments can be obtained prior to the film surface.

Applying the gas stream to the coated solution The carrier materials on which the polymerizate or after applying the gas flow, but before io solution is applied, include those as immersion in the nonsolvent bath, for substrates of artificial leather, e.g. B. Application. Such treatments include woven, knitted or knitted fabrics z. B. the adjustment of the viscosity of the cover woven fabrics or cloths, or natural leather, materials by cooling or heating on any occasionally can paper, film or metal foils appropriate extent. Such an additional loading 15 can be used. Artificial leather is used in However, treatment does not constitute an essential part of the case of the latter by coating the artificial leather process according to the invention. Substrates on the surface of the film after

The film formation on the carrier materials in the practical execution of the process below the invention to be used polymers following stripping of the support materials or by can choose from a wide variety of high- 20 coating of the film after stripping the Molecular materials are chosen, provided that they contain carrier materials. When the carrier material are suitable for forming films. Typical poly- possesses a smooth surface, the surface exhibits Merizates which can be used include the synthetic leather thus obtained having a superior smoothness Polyurethanes, polyamides, polyvinyl chloride and mixed on. Also, by previous creation polymers of vinyl chloride with vinyl acetate, vinyl 25 of suitable embossed patterns on the carrier materials methyl ether or acrylic acid ester. Others also received a leather with a molded pattern borrowed different polymers can either be.

alone or in the form of a mixture for application The application or coating of the polymer solution on the carrier material can be applied

That is done for the preparation of the polymer solution to 30 of the usual tools and working methods,

Solvents using may be any of, for example, knife or squeegee application

those used to dissolve the above devices would be reverse roll coaters

listed polymers are suitable, and must or reverse roll coating ^ curtain flow coating

at least in part with the nonsolvent means or slot mold coating means.

be mixable. With reference to the application of 35 the gas flow can be applied to the carrier materials

Water as a nonsolvent for practical reasons applied as a coating polymer solution under

it is expedient and desirable to use at least partially arbitrary contact angles

water-miscible solvents, e.g. B. dimethyl long, for example in vertical, parallel

formamide, dimethyl sulfoxide, dimethylacetamide, opposite, parallel, rectified and

Oxane, tetrahydrofuran, γ-butyrolactone, pyrrolidone 40 tended to flow. To achieve good

or cyclohexanone, to be used. The solution quality controls are preferably irregular

medium can either be used as a single component or wind speeds and wind pressures avoided,

in the form of a mixture of two or more. The nonsolvent contained in the according to the

come into use. Invention to use nonsolvent bath

These solvents can be included with the nonsolvent 45, can be any, both agent for the polymer, for example water, in relation to the carrier material as well as the polyeiner Amount are added which is so small that merisate material is inactive in the coating solution. no gel formation of the solution is brought about. Preferably, however, water is used because it In this case, the method can be more effective in the cheapest and most accessible non-manner by shortening the process steps represents 5 ° solvent. A mix of two Leads to microporous structures containing one or more nonsolvents can also be used denser surface than inside. be used. Other solvents or

The polymer solution can also contain desired swelling agents which are necessary for obtaining a micro-

if other various additives including filling porous film by regulating the coagulation

substances, pigments, plasticizers, anti-aging properties are favorable, if desired, the

agents, ultraviolet absorbers, non-solvent surfactants.

Agent, silicone oil or wax can be incorporated. The temperature of the non-

The higher the viscosity of the polymer solution, the solvent bath is usually kept at room, the lower the influence due to the fluctuation temperature, although increased or the wind pressure or flow rate without decreased temperatures depending on the cause of any deterioration in the upper composition the coating solution, the gas surface smoothness and uniformity and this is therefore the flow rate and the temperature of the ver for the shortening of the process steps. applied gas flow can be used. In general, however, a viscosity of above is formed. The mechanism by which the microporous 10 poise, preferably 150 to 3000 poise, is formed for the 65 structure of the polymer film in the method of carrying out the method according to the invention according to the invention can be satisfactory as follows. The higher the concentration is to be derived,
the required gas blowing time is thus shorter. If the on the sheet or web-shaped carrier

7 8

material as a coating applied polymer solution steam in order to bring about coagulation, is immersed in the nonsolvent bath, so that the solvent to be used from hygrofused the contained in the polymer solution must be of a scopic nature. Therefore, the solvent fails through the non-solvent, use of non-hygroscopic solvents, while the liquid in the nonsolvent bath 5, for example, of 1,1,2,2-tetrachloroethane, isophorone, penetrates into the bulk of the polymer solution and through nitrobenzene or the like, and does not form microporous this diffuses through, creating a gradual structure due to the lack of semicoagulation Gelation of the polymeric material from its or a colloidal solution. In contrast to Surface is obtained. can in the method according to the invention

On the basis of studies it was found that any solvent regardless of its

that the structure of the polymer solution is applied according to the hygroscopic nature.

The method according to the invention also enables coagulation of the change in the coagulation

Settlement ratio or concentration gradient the treatment within a short period of time,

between the solvent and that in the poly- while the hygroscopic process is an essential

Merisate solution contained nonsolvents in the 15 lent a longer period of time for the completion of the

depends on the course of coagulation. Doing this favors a treatment that requires.

In the hygroscopic process, the ratio or a lower gradient of the concentration structure of the solution is due to the gel formation or tration, the replacement of the solvent by the non-coagulation of the entire polymer in the solvent and leads to the formation of an equal- 20 Solvents during exposure of the oversized microporous structure through a regulated material to moisture in the atmospheric and uniform coagulation. Further, the sphere is fixed, the obtained product being found to have a microporous structure as the coagulation progresses,
fundamentally from the very first gelation state. In the method according to the invention, the surface of the solution is influenced, which however forms the coagulation in the nonsolvent at the beginning of the introduction step, in which, after the outer layer alone has been concentrated, the coating solution in the nonsolvent bath has been effected so that the microporous structure becomes soaked and the diffusion takes place immediately having a denser outer layer and a relatively rougher inner layer after immersion within as short a time as about 0.01 second. 30 is very similar to natural leather.

After the poly has been applied, the microporous film also develops

merisate solution is obtained as a coating on the carrier material by the method according to the invention,

there is a saturated layer of vapor on the surface, fine creases or folds in a manner similar to this

the solution by the evaporation of the solution is the case with natural leather when this is on

by means of, and the solvent molecules formed inside 35 a flexible support sheet and if

slowly diffuse into the atmosphere by folding the film surface inward while the

first through the solution layer and then through the same carrier sheet never forms such creases,

saturated vapor layer while maintaining a

Going through equilibrium. Was put by that.

Bringing the surface of the polymer into contact is based on such a difference in the solution at this point in time with the movement behavior of the microporous structure between the energy-containing gas stream, the saturated two films, which after the hygroscopic vapor phase are disturbed, with a dilution In the drive or according to the method according to the boundary layer of the saturated vapor pressure occurs, the former assumes a microporous structure, which in turn is the diffusion of solvent molecules, and the surface of the solution is much more the latter with a small-pore structure and dense surface layer as opposed to diffusion from inside the solution and having a rough or coarse inner layer favored and eventually collapsing to the surface layer,
of the state of equilibrium. Such a characteristic structure of the nach

Accordingly, the polymer concentration in the art of the very thin solution layer of an inner thickness obtained in the process according to the invention is also exhibited by the fact that half a micron of the solution surface is so high, there are almost the same inner surface areas as that when the coated solution in possesses the nothing of natural leather,
In addition, the leather obtained by the method according to and a dense gelled layer formed on the surface 55 of the invention has an extraordinarily high quality, whereupon the diffusion of the bath solvent and high scratch resistance to such an extent that the nonsolvent is controlled so that a coagulation with the formation of a microscope, which was never formed immediately after the hygroscopic process, was available. This is one of the most beneficial mercury films to make possible. of the invention, since the scratch resistance of synthetic

The method according to the invention is in the 60 leather must be kept sufficiently high, ins-

In contrast to a process in which the over-special due to the fact that scratches, the

pulled polymer solution of a humid atmosphere are once formed on the leather product, hardly

exposed for a period of time is cured or by shoe polish or by wax

and then can be immersed in the nonsolvent and covered over, whereas the natural

is coagulated (this procedure is hereinafter referred to as leather, although it is very resistant to scratches

referred to as the "hygroscopic process"). is sensitive to, effortlessly from such scratches,

In the hygroscopic method, the missing absorbed by covering with shoe polish or the like.

the solvent in the polymer solution can be freed from water.

9 10

By the method according to the invention can and the presence of a denser and very fine

also a high moisture permeability created microporous structure on the surface layer,

For comparison, one of the most important conditions for it was a microporous structure

represents ordinary synthetic leather. after the hygroscopic method by exposure

That according to the method according to the invention 5 of the coated nonwoven fabric for more than 30 minutes

obtained sheet or sheet-like material possesses in an atmosphere at a relative humidity

a unique microporous structure, with that of 50% and at a temperature of 25 ° C

The surface layer is more dense than the inner layer, holding when there is no air movement exerted on it

because the polymer solution, which is applied as a coating.

is, first concentrated only on the surface part, io The coating which is then coagulated in the nonsolvent bath according to the method according to the invention showed a moisture-permeable and therefore the material according to the invention is for speed of 1850 cm ³ / m ² in 24 hours , a bending for use as a top film or sheet of artificial leather or folding resistance of more than 1 million bending of other sheet or web-shaped materials at -5 ⁰ C, and a cream scratch resistance suitable. 15 of 1100 g. In contrast, the rough one was porous

The invention is described below with reference to a coating having a pore diameter of 30 to

Examples in which the stated 700 microns, without the use of air flow

Parts are based on parts by weight. produced, however, showed a moisture permeability of 1950 cm ³ / m ^{2 in 24 hours}

B eis ρ ie 1 1 ²⁰ cracks after repeated bending or folding in one

Extent of 500,000 bends at -5 ⁰ C and

Polyamide staple fiber materials with a thread showed a scratch resistance of 700 g.
size of 3 den and a fiber length of 51 mm

became will using an apparatus - Example 2
Freely laying down webs and by needling 25

Shaped into a web in order to form a felt with a pseudo-polymer solution as in Example 1 with a weight of 250 g / m ² . The felt used in this way was then applied to the held felt in a thickness of 1 mm in a synthetic non-woven fleece as used in Example 1, rubber latex made of acrylonitrile-butadiene mixed poly. Dry nitrogen gas which had been merisat impregnated, squeezed over a with a mangle and 30 calcium chloride absorbing tube at 25 ⁰ C of Feuchin freed a 15 ° / _o aqueous solution of calcium chloride ACTION was immersed with a Windzur coordination of the latex with water speed of 18 m / sec. Washed for 65 seconds, dried and cut into disks of non-woven cloth in a parallel and unidirectional flow direction with a thickness of 1 mm. to the direction of movement of the non-woven fleece The amount of mixed polymer 35 introduced is blown. The gas-treated cloth was then measured at 235 g / m ² . As a coating was applied to the import an aqueous bath at 20 ° C for 10 minutes prägnierte nonwoven fabric, a polymer solution introduced at a and impregnated, with moderately hot water viscosity of 350 poise, by mixing washed 1 hour during and at 120 ⁰ C during 100 parts of polyurethane, which is dried by polyaddition of 8 minutes to form a microporous over 2 moles of diphenylmethane-4,4'-diisocyanate to 1 mole of 40 train with a dense surface layer and a polyethylene adipate with a molecular weight relatively coarse inner layer with respect to 2000 and with OH groups at both ends to form the surface layer. On the other hand, when the chain was subsequently extended with butane, the coating obtained by coagulation after allowing the diol to stand gave 40 parts of calcium carbonate, in static, ie non-flowing, dry 15 parts of polyvinyl chloride resin with a molecular nitrogen gas, only an irregular weight of 800, 10 parts of carbon black and 525 parts of structure with coarse and large pores, even after dimethylformamide was made, in one standing in the nitrogen gas for one hour. 1 mm thick. Then an air stream with a relative humidity of 50% and Example 3
at 25 ° C on the surface of the coated solution 50
applied through a slot nozzle. A polymer solution with a viscosity of

The blowing conditions were adjusted so that the 850 poise was obtained by mixing 200 parts of poly clearance or space from the nozzle 3 mm urethane, which was made by polyaddition of polytetrahydro, the nozzle pitch was 35 mm, the extrusion furan with a molecular weight of 2250 at speed 10 m / sec. The distance was 55 diphenylmethane-4,4'-diisocyanate with subsequent 350 mm chain extension with hydrazine between the solution surface and the nozzle and the blowing angle to the solution surface was 60 parts polyvinyl chloride, 30 parts dioctyl from the nozzle was 90 °. The air flow was applied while phthalate, 20 parts of phthalocyanine blue (ultraviolet for 15 seconds. The absorbent), 685 parts of dimethyl sulfoxide coated nonwoven fabric was then made by a water- 60 (DMSO) and 2 parts of water. In this bath passed at 25 ° C and coagulated therein, then with example water was rinsed in such a slight amount of hot water and dried to a film amount added that no polymer separated, with a thickness of 0.42 mm on the nonwoven The polymer solution produced in this way was formed into fleece. A microscopic observation of a thickness of 1.5 mm as a coating on a polyam cross section of the product thus obtained showed 65 ester film with a thickness of 100 microns in the presence of continuous and uniformly applied reverse coater, and shaped microporous structures with a pore the coated film was temperature with air at a Temdurchmesser 2-3 mMikron in the interior portion of 30 ⁰ C and a relative humidity

11 12

from 35% for 12 seconds with a flow, gravure or engraving application machine up to

speed of 27 m / sec. coated under a thickness of 8 microns. After

Angle of 45 ° drying on the solution surface, the material was then pressed to a

blown. Thereafter, the blown film was developed into a pore pattern similar to that of

aqueous bath containing 6% dimethyl 5 natural leather and became one

sulfoxide, which was kept at 30 ⁰ C, soaked, formed with sheet or web-like material, which for

Rinsed with water, freed from solvent and suitable for use as a leather substitute.

dries, leaving a uniform microporous film obtained after this procedure, but without

Film with a dense surface layer and an application of air blowing treatment wor-

with respect to the surface layer was relatively io den, resulted in a non-uniform and coarse porous

coarse inner layer is obtained. On the other hand, it had a structure that was merely sheet-like or web-like

a film that even after the material with a rough surface without the application of airflow

had been produced, a rough and unevenly-engraved coating or delivered after embossing.

shaped porous structure. ". . ,,

Example6

B e ι s ρ ι e 1 4 _Dje procedure of Example 2 was repeated under staple fiber products of polyester fibers a thread twist of carbon dioxide gas instead of air size of 1.5 den and a fiber length of 38 mm. The coating thus obtained had none of the pores that were defective into a sheet using a transverse cross-section. Such pores were found to be curlers and then needling, but to a degree of 340 per cm ² when the coagulation of a felt with an apparent weight of 220 g / m ^{2 formed} after the coated material was left to stand. This felt was in a 20% solution of fleece under static carbon dioxide gas while polyurethane in dimethyl sulfoxide, which was effected as in 1 hour.
Example 3, had been prepared, a. .
submerged, then squeezed to an extent, 25 example /
that the polyurethane content was 50 parts per 100 parts of a 27% solution of poly-e-capronamide fiber material. (Nylon-6) in methanol containing calcium chloride was Thereafter, a polymer solution, as in the example used as a coating on a sheet of paper 1.0 mm thick game 3, was applied to the felt using and blowing with air in a similar reverse roll coater to applied to a thickness of 30 ways as described in Example 3, subjected to 1.1 mm. The material was then soaked with and then in water. After coagulation, the air at a humidity of 60% and a coating film, the paper was rinsed with water geTemperatur of 25 ⁰ C at a Strömungsgeschwindig- until the calcium chloride in the film verkeit of 40 m / sec. for 10 seconds in the opposite direction, then dried at 80 ° C., a microset flow direction to the direction of movement 35 porous film of poly-e-capronamide was obtained, the coated non-woven felt was blown. Which was thus free from coarse, defective pores and a treated felt was placed in a water bath at a thickness of 0.35 mm, an apparent density of 0.45 g / temperature of 18 ° C and therein coagu cm ^{3 and a moisture permeability of 33 C0 cm 3} / liert. Having After removal of the solvent and after m ^2/24 hours. The film, which in similar drying showed the film in a characteristic microscopic manner, but without the use of air blowing under a scopic structure with a dense surface standing for 12 seconds instead, and relatively a rough interior, had a thickness of 0.50 mm, observation under the microscope. an apparent density of 0.30 g / cm ³ and 25 defects

^. . ,. Adhere coarse pores per cm ² .

Example5 ₄₅ ^{5 J}

A flano textile material made from a mixed example 8

spun yarn of polyamide and rayon (30:70) The procedure of Example 7 was followed by weaving and napping. was made with a turn of a 45 weight percent solution of polymer solution in a thickness of 0.8 mm under 100 parts of polyvinyl chloride with a molecular application of a squeegee or knife application machine 50 weight of 800, in which 15 mole percent vinyl coated. The polymer solution had a viscose acetate copolymerized, in dimethylity of 1600 poise and contained 100 parts of polyformamide, in which 45 parts of dioctyl phthalate as urethane, which had been incorporated by polyaddition of 1 mol of poly-plasticizer, as coating diethylene adipate (molecular weight 1800 ) repeated with 1.6 moles of material. Was after air blowing in a similar diphenylmethane-4,4'-diisocyanate with subsequent 55 manner and after drying at 2O ⁰ C which he chain extender maintained film had with ethylenediamine produced a fully microporous structure have been, 30 parts Siliciumdioxydpulver, 20 parts, and was absolutely free of any coarse pores in the film. Pulp dust, 15 parts carbon black and 385 parts dimethyl- The number of coarse pores increased to formamide. 400 per cm ² , if the film without using the air

The solution applied as a coating was left to stand for a further 12 seconds at 60 degrees

5 ^C C and cooled with air at 20'C with a relative was.

Humidity of 65% at a flow rate of 1 9
speed of 5 m / sec. for a period of

90 seconds blown and then by soaking in The procedure of Example 1 was with the Ab-

coagulated in a water bath. After the removal 65 change repeated that on a non-woven fleece

of the solvent and after drying, a 35% solution of polyurethane was used as a coating,

microporous film obtained. The film was also made by reacting 1 mole of polybutylene

with a varnish of a polyurethane type using adipat (molecular weight of about 1500) with 3 moles

Tolylene diisocyanate and 0.75 mol of butylene glycol in dimethylacetamide and 0.01 mol of triethyjenediamine as a catalyst was applied. The coating thus obtained had a thickness of 0.35 mm, an apparent density of 0.65 g per cm ³ , a moisture permeability of 2800 cm ³ / m ² per 24 hours, a scratch resistance of 1200 g and a flexural strength of more than 1 million bends at -20 ⁰ C.

The coating formed without air blowing had a thickness of 0.543 mm, an apparent density of 0.33 g / cm ^a , a scratch resistance of 750 g, and a flexural strength of less than 50,000 flexures.

When the film was left to stand in the air without using the air flow under the same conditions for the purpose of merely absorbing moisture, the number of faulty large ones changed Pores in the film with the lapse of time for moisture absorption as shown in the following Table is given:

Duration for Flawed Moisture absorption coarse pores (Minutes) per cm ² 0 400 1 400 3 400 5 400 10 250 30th 150 60 72 120 5 180 0.3

35

40

Example 10

Composition: parts

Polyurethane (as in Example 1) 80

Dioctyl phthalate 10

Polyvinyl chloride 20

Soot 30

Calcium carbonate powder 40

Dimethylformamide 520

A coating solution having the above composition was applied to two polyester film samples applied, one sample according to the invention and the other after the hygroscopic Process was treated under the conditions given below.

a) According to the invention:

Flow speed 4m / sec .; 20 "C; air of 65% relative humidity; Distance between the nozzle and the solution surface 10 cm; Ejection angle 90 °.

b) Hygroscopic procedure:

Leave to stand in air at 20 ^° C. and 65% relative humidity.

After treatment for certain periods of time, the samples were placed in water to coagulate, whereupon the solvent was removed. The minimum times required for micropore formation and observed through a microscope are listed in the table below:

thickness
the polymer Hygroscopic Blowing time at
Procedure according to solution V Cl! «AIIICII the invention (mm) (Minutes) (Minutes) 0.5 30th 0.5 1.0 45 0.3 1.5 60 0.45 2.0 150 0.5 4.0 400 0.5

As can be seen from the table above, the method according to the invention enables the Formation of a microporous structure within a much shorter period of time, whereas this at Application of the hygroscopic method requires a much longer period of time.

Example 11

A polyester film was coated with a solution or dispersion (solid content 33 ° / ₀ ) of 80 parts of polyurethane, 10 parts of carbon black and 50 parts of light carbon in dimethylformamide using a knife or blade with a gap of 1.5 mm and under the following conditions treated.

The method according to the invention. 20 ⁰ C, air with 65% relative humidity, 4 m / sec, 40 seconds, distance between the nozzle and the solution surface 10 cm, Ausdrückwinkel 90 °.

Hygroscopic method: 20 ^° C., leaving to stand in air with a relative humidity of 65%.

Thereafter, the formed film of 0.63 mm was peeled off from the polyester film. The film was then laminated onto a nonwoven fabric (the same as used in Example 1) coated with an adhesive of 50 parts of polyurethane and 10 parts of dimethylformamide at a rate of 50 g / m ² and incorporated coagulated in water and finally cut into slices 1.5 mm thick on part of the non-woven cloth. A comparison of the performance and behavior of each of the products is given in the table below.

proceedings Hygro Nature- according to scopic JCUCI invention proceedings Yes Wrinkling Yes no 500 Scratch resistance (g) 1100 800 Moisture through nonchalance 4800 (g / ^cm2 / 24 hours) .. 2020 1850 Inner surfaces 1.1 area (m ² / g) 1.2 1.8

The wrinkling was observed when the coated film was bent inward.
The scratch resistance was expressed by the loading weight at which the sample received faint scratches using a Clemen scratch hardness tester.

The moisture permeability was measured according to JIS Z 0 20 8.

The inner surface area was determined by the amount of nitrogen adsorption at low temperature (the temperature of liquid nitrogen) is determined

and then calculated using the equation of BET adsorption isotherm.

From the table above it can be seen that in the hygroscopic method none Creases have been developed, but in the process according to the invention fine creases similar to those of very similar to natural leather obtained and thus made according to the behavior of the invention Products have been given a high technical value.

Claims (2)

Patent claims: 1. Process for the production of vapor-permeable, microporous coatings on fibrous Documents or microporous films by applying a solution of a polymer in a organic solvent, which may optionally include an addition of an at least partially with the Solvent-miscible non-solvent for contains the polymer in an amount so small that no gel formation is caused, on a fibrous surface or on an impenetrable casual carrier material, coagulation of the polymer by treatment in a bath of one which does not dissolve the polymer and one with the organic one Solvent miscible non-solvent, removing the solvent and drying of the product obtained as well as in the case of the use of an impermeable carrier material Stripping off the formed coating therefrom, characterized in that one on the surface of the in the form of the solution of the polymer on the carrier material or Base applied coating initially to concentrate the outer layer of the coating solution a gas flow opposite to the Polymer solution of inactive gas at a flow rate of 1 to 50 meters per Lets act for a second, the polymer still remaining in the uncoagulated state, and only then does the polymer coagulate in a known manner. 2. The method according to claim 1, characterized in that the gas flow during a Applies a period of at least 5 seconds. 109 512/370