DE1965587A1 - Process for the production of reversibly water vapor-absorbing flat structures - Google Patents

Description

Badische Anilin- & Soda-Fabrik AG

Our reference: O.Z. 26 535 vG / Ot 67OO Ludwigshafen, December 29, 1969

Process for the production of reversibly water vapor absorbent flat structure

The invention relates to a method for the production of reversibly water vapor-absorbing flat structures, which by application of polymers containing ester groups of tertiary alcohols on carrier materials such as fibers, nonwovens, fabrics and heating the Flat structures are obtained, the polymer foaming to form a foam.

Flat structures which, when used as intended, come into direct or indirect contact with the human body, Like clothing, shoes or upholstery materials, etc., should be "breathable" so that they do not get in at low temperatures cause an uncomfortable feeling of coldness and, at higher temperatures, unpleasant sweating. A big number Flat structures made from natural materials such as wool, cotton, leather, etc. have these properties breathability and, as a result, are comfortable to wear.

This is important for corresponding flat structures made from synthetic materials, such as artificial leather Property only available to an unsatisfactory degree.

In order to achieve the property of breathability, it is not sufficient, as has been attempted very often technically, such to train flat structures gas-permeable. Such gas permeability is found in synthetic materials, for example Fibers before. The desired effect of breathability in natural substances is given by the fact that they have the ability to to bind or release water vapor at a sufficiently high speed. A measure of breathability is therefore the water vapor absorption per square meter of leather

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or synthetic leather or in g / kg. The task of artificial leather breathable training has not been adequately solved, as the following table shows:

What s erdampfähme

in g per. r 2 8th 1 mm 1 2 in g / kg 12th η and 15th 20th 25th 30th 50 after hours 1 strength 20th 25th 12th 30th 35 8th 45 9 synthetic leather A 15th 30th 35 30th 25th 35 40 45 ¹¹ B 15th 35 40 25th 30th 40 40 60 C. 25th 40 80 40 30th 45 40 110 ¹¹ D 25th 25th 65 50 30th 40 45 130 Leather cowhide 25th 95 90 ¹¹ sole leather 20th 80 105

Φ The artificial leathers are products that already are now widely used as shoe upper leather. The natural leathers are commercially available Qualities.

The present invention is based on the object of synthetic to produce flat structures that are breathable.

It has been found that this task is surprisingly easier Way can be solved if such polymers are applied to carrier materials that contain at least 5% by weight? Ethylenic ester unsaturated carboxylic acids with tertiary alcohols with 4 to 8 carbon atoms Contained in copolymerized form and then at temperatures above the decomposition temperature of the tertiary esters heated. When heated, the polymers decompose with elimination of an olefin, e.g. isobutylene, with free carboxyl groups arise in the polymer. The olefin which is split off causes the polymer to foam at the same time. This creates the necessary large inner surface, which causes a sufficiently rapid absorption of water vapor.

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In all cases, the task is to use carrier materials that have the necessary strength values, such as tensile strength, Elongation and tear resistance must be combined with the polymers as evenly as possible. Consequently The process is technologically easiest to carry out when the polymers used are in finely divided form, most expediently in the form of aqueous dispersions or as fine powders or solutions.

The aqueous dispersions of the polymers to be used preferably contain 20 to 70 %, preferably 25 to 55 %, of polymer. The polymers contain at least 5, but preferably more than 20 % esters of the tertiary alcohols. Suitable ester tert. Alcohols are those of ethylenically unsaturated polymerizable acids with aliphatic or cycloaliphatic alcohols with 4 to 8 carbon atoms, but preferably with 4 carbon atoms, ie esters of tert. Butanols. Suitable esters of tertiary alcohols are those of ethylenically unsaturated copolymerizable carboxylic acids which contain 3 to H C atoms, such as acrylic, methacrylic or maleic acid.

As comonomers, which can optionally build up the polymer together with the unsaturated esters of tertiary alcohols mentioned, copolymerizable, ethylenically unsaturated compounds are suitable, such as acrylic esters or methacrylic esters of alcohols having 1 to 9 carbon atoms, vinyl esters, vinyl chloride, vinylidene chloride, styrene, butadiene, among others.

Are particularly advantageous for the method according to the invention the dispersions of such polymers, the tert in addition to the carboxylic acid esters. Alcohols contain copolymerizable acids which have a dissociation constant above 10.

-H-

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A suitable copolymerizable acid with a dissociation constant above 10 is preferably vinyl sulfonic acid. It can also e.g. styrene sulfonic acid, 3-methacryloxypropyl (or -äthyDsulfonsäure, 3-acryloxy-propyl- (or -ethyl) sulfonic acid, vinylphosphonic acid and others can be used. The salary of the copolymer of such a polymerized acid is 0.1 to 10, preferably 0.5 to 6 wt. based on the total amount of monomers.

It should also be pointed out that the copolymerization of 0.5 to 20 wt.% _T based on the total amount of monomers having strongly polar groups, such as acrylic acid or acrylonitrile, has advantages. The polymer dispersions can be prepared by the known processes by polymerizing the monomers in the aqueous phase with the customary auxiliary systems. The polymers to be used according to the invention have a K value (according to Fikentscher) which is greater than 25.

Support materials are to be understood as flat structures, the structure of which preferably allows gases to flow through. Particularly Flat structures made up of fibers, such as nonwovens, woven or knitted fabrics, are suitable. Also mushrooms and close-knit nets are suitable. The fibers can be organic or inorganic in nature. There are also foam sheets with mostly open ones Cells or openings (pores), e.g. those made of polyolefin foams.

Carrier materials composed of synthetic polymers are particularly suitable. Applying the dispersions the carrier materials can be made, for example, by dipping, brushing, pouring, spraying or impregnating. The polymers can also be rolled onto the carrier materials.

According to a particularly advantageous embodiment of the method, the carrier materials with the aqueous dispersions of Impregnated with polymers and then initially below the decomposition

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temperature of the polymers containing tertiary ester groups, i.e. below the temperature at which the olefins are split off the water is evaporated. The flat structures thus obtained are then heated to temperatures above the decomposition temperature of the polymer, so that decomposition begins. This process can be carried out either at normal pressure, at reduced pressure or at elevated pressure, for example in a press will. In the latter case, a correspondingly smooth or grained surface is obtained from the start, depending on the surface the press plate. If you work with normal pressure, the surface becomes a bit choppy. However, one can use them according to known ones Grinding methods flat, e.g. on leather grinding machines. If you work at reduced pressure, they become during the foaming process occurring propellant gases are removed particularly quickly.

The acid groups exposed by the decomposition process are expediently at least partially neutralized, for example converted into their sodium salt, because this increases the absorption of water vapor and the desired breathability. After the neutralization has taken place, which expediently takes place in the aqueous phase, the product is washed, dried and then trimmed in a known manner, for example finishing lines are applied. You can also neutralize with gaseous ammonia; then he left off the washing process.

The decomposition temperature of the carboxylic acid ester is the temperature at which the polymerized carboxylic acid esters split into carboxylic acids and olefins.The decomposition temperature depends on various factors, e.g. on the type of carboxylic acid ester used or its content in the polymer * The decomposition temperature must be determined on a case- by-case basis will.

The decomposition of polymers with ester groups of tertiary alcohols in aqueous dispersions or solutions is also dependent on the pH. It is therefore advantageous to set a pH value of 1.5 and below before the decomposition process.

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It is expedient to work in the pH range 1.5 to 0.1. As a result, particularly fine-cell foams are created, which enable water vapor to be absorbed quickly enough. This measure of setting a low pH makes it possible to ^{carry out the decomposition process between 70 and 170 °} C. without the time required for this exceeding 30 minutes. The setting of the low pH value is achieved by adding sulfuric acid, phosphoric acid, benzenesulfonic acid, lbluenesulfonic acid or compounds which split off acids.

The appropriate temperature and heating time to be used in each case depend on the thermal resistance of the substrate (fiber, fleece, woven, knitted fabric) and on the composition of the polymer used for coating and any other additives used. The most suitable temperatures are usually in the range between 70 and 170 ° C, preferably at 100 to 1 JLO ⁰ C and the heating time in the range of 30 lake. to 30 minutes, preferably 2 to 15 minutes.

It has also been shown that, according to a particularly advantageous embodiment of the method, the tert. Polyfunctional compounds are added to polymers containing ester groups which can react with the acid groups of the polymer exposed by the decomposition process, for example polyfunctional "Ie alcohols such as glycerol, glycol, etc. This achieves a crosslinking reaction which gives the flat structure greater stability against the action of There is water, so that when such flat structures are stored in water, they swell but not disintegrate.Such compounds can be added in amounts of 0.5 to 60 % , preferably 3 to 25% by weight, based on the amount used Polymer.

To increase the stability of the flat structure against the influence of water, it is also possible after carrying out the decomposition process to react the carboxyl groups of the polymeric foam with multifunctional compounds, e.g.

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with polyvalent amines, isocyanates or polyvalent metal ions such as aluminum, chromium or calcium ions.

As long as flat structures are to be produced using dispersions of the polymers described up to a square meter weight of about 100 g, it is sufficient to use the dispersions in the usual viscosity range. However, if higher square meter weights, i.e. thicker layers, are to be produced, such as, for example, water-vapor-absorbing flat synthetic leather, which are suitable for shoe soles or shoe upper leather, it is technically difficult to impregnate the carrier materials homogeneously with the necessary amount of dispersion, so that sufficient before the drying process Plastic dispersion has been applied. It has proven to be useful here to add processing aids to the dispersions which, when the temperature of the dispersions is increased to approximately above 50 ° C., cause the dispersions to coagulate. Such substances which cause such a heat sensitization are known, for example polyvinyl methyl ether, among others. For example, 1 to 50 parts, preferably 3 to 10 parts, of polyvinyl methyl ether can be used per 100 parts of the polymer to be used according to the invention. In this way of working, it is advisable to proceed in such a way that, after the impregnation process, if possible, the coated materials are briefly heated to about 5 to 60 ° C on the base on which the fleece was placed before the impregnation. carried out, namely at temperatures between 50 and 200 ^° C. As a result, the dispersion coagulates on the carrier material j the entire structure is thus already transportable in the moist state and can be fed to the drying process. After drying, as already described, it is then thermally decomposed and further processed. The heating is expediently carried out by means of a heat exchanger. This is understood to mean flat structures made of metal, for example sheet metal, which are in direct contact with the coated carrier materials.

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"Breathable" flat structures produced in this way must have the necessary flexibility with regard to their use as upholstery and clothing materials. When they have absorbed water vapor, the water bound by the polymers • has a softening effect. However, if such products are dried out completely, the flat structure can become relatively stiff if the binding agent does not inherently have the necessary degree of softness. In order to prevent this effect, it is advisable either to use polymers which by themselves have the necessary flexibility P even in a completely dry state, for example due to the usual softening measure, or one can, as is also common with leather, Add humectants such as polyhydric alcohols, glycol, glycerine, pentaerythritol, polyethylene oxide _s polypropylene oxide and others. The amount added is expediently between 5 and 40 % by weight, based on the weight of the polymer. It is expedient to use compounds which have such a high molecular weight that evaporation no longer takes place to such an extent that the softening effect is lost over time.

The desired "breathability ^{11" of} the flat structure is achieved because the hydrophilic character of the binding agent allows water vapor to be bound and because of the sufficiently large "internal surface" water vapor absorption can take place quickly. These two basic requirements are also given for natural substances. For example, the leather has a very large inner surface due to the wax-like fibril structure.

Garments or cushioning materials have the property of breathability if they are able to lower the humidity between the body and the garment to such an extent that water cannot occur in the liquid phase. Basically there are 3 different tasks:

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1. In the case of textiles, e.g. shirts, the water vapor must first be absorbed by the tissue so quickly that the necessary lowering of the water vapor concentration between Body and tissue enters. At the same time, the water absorbed in this way can also be on the side facing away from the body continuously evaporate while wearing, so that in such a case there is no requirement that the fabric must store a certain minimum amount of water during the period of wearing.

2. In the case of the shoe upper leather, this situation is different, because the dressing of the leather on the side facing away from the body allows the water to evaporate during the period of wearing is largely inhibited. In this case, the requirement must be made that the total mass of the upper leather binds the water vapor sufficiently quickly and also binds a certain absolute amount of water during the wearing time.

3. In the case of upholstery leather, due to the application, the Dressing of the leather facing the body. As a result, care must be taken in this case that either the dressing itself has sufficient water vapor absorption capacity or is perforated to a sufficient extent, that the underlying water vapor absorbing layer in comes into direct contact with the atmosphere saturated with water vapor

As a result, smaller amounts of the corresponding polymers are sufficient for the first case, while hol in the second and third cases
have to.

If higher quantities and thus higher m ² weight are required

Using the method described, it is possible to produce flat structures that absorb water vapor, e.g. artificial leather, which have a much higher water vapor absorption than natural leather. So you can, for example, when using polyacrylic acid

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tertiary butyl ester by the process described above flat structures with a water dam]
- produce at 1 mm thickness.

ρ structures with a water vapor absorption even beyond * 100 g / m

As can be seen above, it is because of the different Embodiment of the subject matter of the invention only possible to provide general information on the appropriate amounts of polymer to be applied to the carrier materials. In the case of the Of artificial leather, it is advantageous, but not mandatory, based on one part by weight of carrier material, 0.5 to 5 parts by weight of the polymer to be used according to the invention, ie to use polymers containing the ester group of tertiary alcohols. However, it is advantageous to use 1 part to 2 parts of polymer, based on one part by weight of carrier material. In the case of the production of flat textile structures that are used, for example, as clothing materials, considerably smaller amounts of polymer, based on the carrier material, can be used. For example, based on 100 parts by weight of carrier material, it may be advantageous to apply 2 to 10 parts by weight of polymer.

If you have flat structures with a very high range of water vapor absorption produces, which no longer have to be required for clothing and upholstery materials, decreases at the same time "their stability towards liquid water, by the given high water vapor absorption it is possible, quite a number other important properties, such as resistance to cold, abrasion, etc., to bring them to the required level in each case that the copolymers to be used according to the invention are combined with other polymers. The easiest way to do this is that other aqueous dispersions are added to the aqueous plastic dispersions and the process is carried out with this mixture. So you can e.g. a dispersion of a copolymer of butyl acrylate with dispersions based on polyvinylidene chloride, polyvinyl chloride, Mix polyacrylic esters, polymethacrylic esters, polyvinyl esters, polydienes, etc. But it is also possible to produce these polymer blends by the fact that

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adding other polymers in powder form to aqueous dispersions. This is particularly useful when the other polymers in dispersion form. This is the case with polyolefins, for example. Here you can proceed like this that dispersed copolymers containing the ester groups of tertiary alcohols are mixed with polyethylene powder is evenly distributed, and then proceeds as it does above for the production of water vapor-absorbing two-dimensional Structure was described.

It is of course possible to disperse the added polymers into an aqueous dispersion in the form of solutions. This is of interest, for example, if you want to combine with polymers, which on the one hand are very difficult to disperse are to be produced, but on the other hand are so soft that the production of the powder is subject to technical difficulties bumps. This is the case, for example, with polyisobutylene, which is expediently dissolved in aliphatic hydrocarbons in the dispersions are incorporated. In general, it is advisable to use such amounts of other polymers that for 1 part of the polymer to be used according to the invention 0.1 to 10, preferably 0.5 to 2 parts of other polymers omitted.

In addition, you can of course the polymers further Adding additives such as fillers, dyes, fungicides, flame retardants, finely ground other foams, short fibrous structures such as asbestos, short-cut fibers up to a fiber length of up to 30 mm, but preferably less than 0.5 mm. Depending on the properties of the flat structure, in particular of the carrier materials and binder combinations used, these can be used for such applications where water vapor absorption and water vapor release are important is. This is the case in the entire field of clothing, although in individual cases the absolute amount of desired water vapor absorption can be very different.

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In the production of artificial leather for shoe outerwear, the task is to use at least the same amount per shoe To bind water vapor during a normal period of wear, as is the case with leather. In this case, practically the entire The amount of water vapor in the synthetic leather is bound because it evaporates of water vapor on the side facing away from the body can only take place to a small extent, since there is a corresponding one here Finishing must be applied, which both the desired color effects and a water-repellent effect should achieve. For this purpose, for example, waxes and polymers of acrylic ester dispersions are used. With the artificial leather that has been used up to now There has recently been a very strong trend to carry out this dressing with polyurethane.

The task is different when it comes to uses in which the flat structure is capable of carrying out the The side facing away from the body to release water vapor again to a significant extent while wearing. This is e.g. with clothing fabrics (Shirts) the case. A much smaller absolute water vapor absorption of the order of magnitude is sufficient here

2
between 30 to 50 g / m, as the side facing away from the body can continuously release water vapor during the period of wearing. The water vapor-absorbing substrate absorbs on the side facing the body and thus lowers the water vapor concentration so much that dripping "that is to say perspiration" cannot occur. At the same time, however, this water vapor is released again during wearing.

The parts mentioned are parts by weight and the percentages are percentages by weight.

example 1

1 m of splice fiber fleece made of a polypropylene with a proportion of 2 % by mass soluble in n-heptane and a weight of 600 g / m was impregnated with a 28% liquor composed as follows:

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150 parts of a 40% emulsion polymer of acrylic acid tertiary butyl ester,

9.5 parts of 10 % sulfuric acid,

3 parts of a 20% solution of an oxethylated fatty alcohol, 24 parts of a 15% aqueous solution of polyvinyl methyl ether

50 parts of water required to obtain a viscosity suitable for impregnation. The liquor has a pH value from 1.

The thoroughly impregnated fleece is gently squeezed off and brought into contact for a few seconds with metal surfaces which have a temperature of 150 ° C., so that partial coagulation of the material to be impregnated takes place. With this treatment one obtains an easy-to-handle, flat structure, which is dried at 75 ⁰ C.

The flat structure is then treated in a press for 30 minutes at 150 ° C under a pressure of 20 atmospheres, then stored in 5% sodium bicarbonate solution, washed thoroughly, air-dried and stored at 23 ° C / 50 % r.h. conditioned *

The flat structure obtained is exposed to an atmosphere containing 100 % relative humidity.

The water vapor absorption of the flat structure is according to 1,2,8 and 12 hours detected. Table 2 shows the water vapor absorption to be seen in g per m and mm thickness and in g / kg.

The flat structure is accordingly in the water vapor absorption better than the artificial leather investigated and achieved, for example, if the amount of water vapor absorbed is related to the surface and the layer thickness, the level of the two types of leather, however, is related to the weight of the flat structures, it is clearly superior to them too.

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Example 2

2
• 1 m of splice fiber fleece made of a polypropylene polymer with a proportion of 24 % soluble in n-heptane and which is one weight

of 600 g / m, the following is made with a 25-liter liquor Impregnated composition:

150 parts of a 40 igen emulsion polymer of acrylic acid tertiary butyl ester,

6.5 parts of 10% sulfuric acid with

2.5 parts of the 20% aqueous solution of an oxethylated Fatty alcohol.

The liquor has a pH value of 1.

It is still a mixture of 72.5 parts of a 55 Sfigen Dispersion of an emulsion polymer composed of 91 parts of vinylidene chloride and 9 parts of methyl acrylate, 2.5 parts of a 20 Sfigen aqueous solution of an oxethylated fatty alcohol added and adjusted to pH 1 with aqueous sulfuric acid.

The mixture of dispersions is diluted with 50 parts of water and then 45 parts of a 15 strength aqueous dispersion of Polyvinyl methyl ether with a K value of 45 was added. Afterward the batch is diluted by adding 100 parts of water, that its viscosity allows perfect impregnation of the fleece. Production of the flat structure from the Impregnable fleece is carried out as in Example 1.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours is determined and shown in Table 2 *

Example 3

1 m of splice fiber fleece made of polypropylene with a proportion of 24 % soluble in n-heptane and a weight of 600 g / m is impregnated with a 35% aqueous liquor of the following composition:

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250 parts of an emulsion copolymer composed of 93 parts of tertiary-butyl acrylic acid 4 parts of methyl acrylate

3 parts of acrylonitrile

are adjusted to pH 1 with 40 parts of 30% phosphoric acid containing 5 parts of a 20% aqueous solution of an oxethylated fatty alcohol. Then, ^ O parts of a 15 % aqueous solution of a polyvinyl methyl ether are added.

The flat structure is produced as in Example 1.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours it is found and shown in Table 2.

Example 4

ο
1 m of splice fiber fleece made of polypropylene with a proportion of 24 % soluble in n-heptane and a content of 600 g / m is impregnated with a 25 * 5 / own liquor of the following composition.

150 parts of a 40-liter emulsion polymer of acrylic acid tert-butyl ester and 3 parts of a 20% strength aqueous solution of an oxethylated fatty alcohol. are mixed. The approach has a pH of 1.

Then 24 parts of a 15 JCigen aqueous solution of a polyvinyl methyl ether added.

After homogenizing the batch and diluting the initially highly viscous batch with 75 parts of water, the production of the flat structure as in Example 1 take place.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours is determined. The results are shown in Table 2.

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Example 5

1 m of a needled fleece made of polycaprolactam (nylon 6) with a weight of 200 g / m is impregnated with the following composition:

Approach 1

with a weight of 200 g / m is with a 25 Siigen liquor

150 parts of a coarse aqueous emulsion copolymer composed of 93 parts of tert-butyl acrylic acid, 4 parts of methyl acrylate, 2 parts of vinylsulfonic acid and 3 parts of acrylic acid; 2.5 parts of the 20% solution of an oxethylated fatty alcohol

Approach 2

72.5 parts of a 55% emulsion copolymer from 91 parts of vinylidene chloride and 9 parts of methyl acrylate are mixed with a mixture of 5 parts of 10% sulfuric acid and 2.5 parts of a 20 jSigen aqueous solution of an oxethylated Fatty alcohol adjusted to pH 1.

The mixture of the two approaches is diluted with 50 parts of water, before 40 parts of a 15% aqueous solution of polyvinyl methyl ether can be added. After homogenizing the batch and diluting the initially highly viscous batch with 100 parts of water This has an impregnation consistency and it can be 'further processed' to a flat structure as in Example 1 take place.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours it is determined and shown in Table 2.

The flat structure is considerably superior to the two types of leather.

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Example 6

2
1 m fleece made of polycaprolactam (nylon 6) with a weight of

2
200 g / m 2 is impregnated with a 27-point liquor of the following composition:

Approach 1

150 parts of a 40 £ aqueous emulsion polymer of 93 parts acrylic acid-tertiary-butyl-ester, H parts of methyl acrylate, 2 parts of vinyl sulfonic acid and 3 parts of acrylic acid are added 2.5 parts of a 20 #igen solution of oxyethylated fatty alcohol and 10 parts of diglycol; the pH is

Approach 2

72.5 parts of a 55% emulsion copolymer from 91 parts of vinylidene chloride and 9 parts of methyl acrylate are mixed with a mixture of 5 parts of 10% sulfuric acid and 2.5 parts of a 20% aqueous solution of an oxethylated fatty alcohol adjusted to pH 1.

The two batches are combined with stirring and diluted with 50 parts of water before 40 parts of a 15% aqueous solution of polyvinyl methyl ether are added. After the batch has been homogenized and the initially highly viscous batch has been diluted with 100 parts of water, it has an impregnation consistency and it can be further processed into the flat structure as in Example 1.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours is determined and shown in Table 2 *

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Example 7

ρ
1 m of polyamide (nylon 6) fleece with a weight per unit area of 200 g / m is impregnated with a 29 igen liquor of the following composition:

Approach 1

150 parts of a ¹ IO £ aqueous Emulsionsmischpolymerisates of 93 parts acrylic acid-tertiary butyl ester, 4 parts of methyl acrylate, 2 parts of vinyl sulfonic acid and 3 parts of acrylic acid, 2.5 parts of 20 £ solution of an oxyethylated fatty alcohol and 20 parts of diglycol added. The pH is

Approach 2

72.5 parts of a 55% emulsion copolymer 91 parts of vinylidene chloride and 9 parts of methyl acrylate are mixed with a mixture of 5 parts of 10% sulfuric acid and 2.5 parts of a 20 iigen aqueous solution of a fatty alcohol pH adjusted to 1.

Both approaches are --sammengegeben under stirring and diluted with 50 parts of water before 40 parts of a 15 Jt aqueous solution of polyvinyl ether can be added. After the initially viscous batch has been homogenized with 100 parts of water, it has an impregnation consistency and it can be further processed into a flat structure as in Example 1.

The water vapor absorption of the ready-to-use, flat structure after 1, 2, 8 and 12 hours is determined and shown in Table 2.

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Table 2

Water vapor absorption after hours

Leather A / B per m ² / l mm strength 12th 1 2 g / kg 12th Artificial leather A / D 1 2 8th 8th Flat structures 90 70 110 250 according to example 1 25th 40 70 50 60 90 210 I65 2 20th 30th 40 75 50 95 135 210 3 20th 35 60 90 60 100 170 250 4th 20th 35 80 380 120 I8O 220 38O 5 120 175 315 425 140 200 320 430 6th 135 195 350 355 120 I80 36O 38O 7th 110 160 300 80/95 3O / 3O 330 40/45 9O / IO5 HO / 130 20/25 25/40 65/80 25-50 25-30 30-40 40-45 45-60 15-25 15-35 20-40

Example 8

Fabrics made of polypropylene tapes are immersed in an approximately 45% aqueous dispersion of a copolymer of 89 parts of tertiary butyl acrylic ester, 6 parts of vinylsulfonic acid and 5 parts of methyl acrylate with a K value of 60 and a pH value of 1.5 and then added in the drying cabinet 130 ^° C. heated for about 5 minutes, during which the coating foams.

If the flat foam structure obtained in this way is exposed to an atmosphere saturated with water vapor after conditioning for 24 hours at 23 ° C. and 50 t relative humidity, up to about 60 % water, based on the dry weight of the entire structure, is obtained in 24 hours , recorded. If the structure is then stored again in a standard climate, the absorbed moisture is released again. This cycle can be repeated as often as you like.

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10% by weight of silica gel can be added to the aqueous dispersion.

Example 9

The procedure is as in Example 8, but with a 40 Dispersion of the copolymer from 9 ^ parts of acrylic acid tertiary butyl ester, 2 parts of vinyl sulfonic acid, 4 parts of methyl acrylate (K value 65) treated.

The foam structure is coated on both sides with a solution of 200 parts of a mixed polyamide composed of 120 parts of AH-SaIz and 80 parts Caprolactam in 675 parts of methanol and 75 parts of water, to which 100 parts of 2-ethylhexyl hydroxybenzoic acid ester are added was coated and dried at 70 ° C for 120 minutes.

The flat foam structure coated in this way has a similar ability to absorb and release water vapor as that according to Example 8 foam structure obtained.

Example 10

Staple fibers of Polyterephthalsäure-glykolester are sprayed with an aqueous dispersion of the copolymer of Example 1 and dried as in Example 9 * The thus treated staple fiber is processed in a carding machine to form a web and this leads to closing with IiJO ⁰ C in a sheet-like foam formation which in relation to the water vapor absorption and release behaves like the structure in example 8.

Example 11

A tricot fabric made of polyacrylonitrile fibers is coated with the polymer dispersion according to Example 8 by roller application and

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then treated as in Example 8. A "breathable", flat structure is again obtained.

It is also possible to use the copolymer instead of in dispersion in 20% solution apply in tetrahydrofuran. The result is the same.

Example 12

A web of Polyterephthalsäureglykolester fibers is impregnated with an about 35 £ aqueous dispersion of a copolymer of 85 parts acrylic acid tert-butyl ester, 2 parts of vinylphosphonic acid and 13 parts of methyl methacrylate (pH 1.5) ", dried at 40 ⁰ C. and then irradiated with a 500 watt IR radiator (distance 8 cm) for 5 minutes. A flat foam structure is obtained with a similar ability to absorb and release water vapor as the structure in Example 1.

Example 13

20 parts (based on the solids content of the dispersion) of glycerol are added to a 50% aqueous dispersion of a copolymer composed of 94 parts of tertiary-butyl acrylic ester, ¹ part of methyl acrylate and 2 parts of vinyl sulfonic acid. This dispersion is applied onto a textile web of polyamide, in such amounts that 1 part polymer account for 5 parts of the poly araidgewebes * Thereafter, the coated structure to nearest 5 hours at 30 ⁰ C is dried. The mixture is then heated to a temperature of 130 ^° C. for 15 minutes, during which the flat structure foams * The flat structure obtained is stored in an ammonia atmosphere for a period of 1 hour.

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Example 14

An aqueous dispersion of a copolymer of 91 parts acrylic acid tert-butyl ester, 4 parts of methyl acrylate, 3 parts of acrylic acid and 2 parts of vinyl sulfonic acid, are based on the Pestgehalt the dispersion, 15 wt.% 1,2-propanediol was added. The mixture obtained is spread onto a polyacrylonitrile fabric, 1 part of polymer being used for 3 parts of the fabric. The fabric treated in this way is ^{dried at 30 °} C. for one hour and then heated to 130 ° C. for 15 minutes. The result is a flat, foam-like structure that is particularly resistant to the effects of alkalis.

If one works without the addition of 1,2-propanediol, the structure becomes easy due to the action of alkalis of the same concentration destroyed.

Example 15

A ridiculous structure produced according to Example 5 is cut to size in the form of insoles. These insoles are inserted into shoes that are worn by test subjects for a period of 12 hours. During this time the Soles absorbed an average of 400 to 500 g of water vapor per square meter of sole material. It was made by the test subjects consistently found a comfortable fit. Within Over a period of 12 hours, when the shoes are not used, all moisture is released again.

109829/191 0

Claims (8)

- 23 - O.Z. 26 535 claims 1. A process for the preparation of reversibly steam-receiving sheet-like structures by applying polymers to carrier materials, characterized in that Polymersate, the weight of at least 5 wt. £ esters of ethylenically unsaturated carboxylic acids with tertiary alcohols with H to 8 C atoms, is applied to carrier materials and heated to temperatures above the decomposition temperature of the carboxylic acid ester. 2. The method according to claim 1, characterized in that aqueous dispersions of the polymers are applied to carrier materials, then the carrier materials are dried and then heated to temperatures above the decomposition temperature. 3. The method according to claim 1 and 2, characterized in that dispersions or solutions are used which have a pH of 1.5 and below. 4. The method according to claim 1, 2 and 3, characterized in that polymers are used which contain 0.1 to 10 wt. 5. Process according to Claims 1 to Ί, characterized in that polyfunctional compounds are added to the polymers as a crosslinking component. 6. Process according to Claims 1 to 5 » characterized in that the foamed polymers are reacted with polyfunctional compounds. 109829/1910 - 2h - OZ, 26 535 7. Process according to Claims 1 to 6, characterized in that the acid groups of the foamed polymer are completely or partially converted into their salts. 8. Process according to Claims 1 to 7, characterized in that polyvinyl methyl ether is added to the aqueous polymer dispersions before use, the mixture is then applied to carrier materials and the coated carrier materials are treated with heat carriers for a period of 5 to 60 seconds before drying, which have a temperature between 50 and 200 ⁰ C, treated. Badische Anilin- & Soda-Pabrik AQ 109829/1910