US3791849A

US3791849A - Process for the manufacture of a chemically bondedtextile sheet material based on synthetic fibers and having a high water vapor absorption capacity

Info

Publication number: US3791849A
Authority: US
Inventors: K Hammer; H Porrmann
Original assignee: Kalle GmbH and Co KG
Current assignee: Kalle GmbH and Co KG
Priority date: 1969-10-15
Filing date: 1970-10-13
Publication date: 1974-02-12
Anticipated expiration: 1991-02-12
Also published as: LU61878A1; NL7014850A; DE1951977A1; GB1324877A; CS204966B2; DE1951977C3; ES384505A1; JPS4948596B1; BE757409A; FR2064354A1; DE2046664A1; SE364081B; CA937463A; FR2064354B1; CH1526470D; DE1951977B2

Abstract

This invention relates to a process for the manufacture of chemically bonded, textile sheet material based on synthetic fibers, in which a polymer material in the form of a solution or dispersion is incorporated in the flexible textile sheet material and the polymer material is then coagulated, which comprises impregnating the textile sheet material containing synthetic fibers with a liquid binder system containing (a) a liquid aqueous dispersion of an elastomer, (b) a liquid aqueous solution of a hydrophilic polymer, and (c) a liquid aqueous emulsion of a long-chain aliphatic monoisocyanate and/or diisocyanate, or an aqueous dispersion of an ethylene imine reaction product of a monoisocyanate and/or a diisocyanate; heating the textile sheet material to the coagulating temperature of the elastomer; further heating the impregnated textile sheet material to a temperature in excess of 100*C, but below the softening temperature of the fibers contained in the textile sheet material; treating the sheet material with a washing liquid; and drying the sheet material.

Description

tlnited States Patent Hammer et al.

[451 Feb. 12, 1974 ABSORPTION CAPACITY Inventors: Klaus-Dieter Hammer, Finthen;

Herbert Porrmann, Konigshofen, both of Germany Kalle Aktiengesellschaft, Wiesbaden-Biebrich, Germany [73] Assignee:

[22] Filed: Oct. 13, 1970 [2]] Appl. No.: 80,335

[30] Foreign Application Priority Data Oct. 15, 1969 Germany 1951977 Sept. 22, 1970 Germany 2046664 [52] US. Cl. ..117/63,117/135.5,117/138.8 F, 1l7/l38.8 N, 117/140 A, 117/161 UE, 117/DlG. 7, 260/296 RW, 260/296 WA [58] Field of Search 117/138.8 F, 138.8 N,

117/161 UT, 161 UE, 163,63, 140 A, DlG.7,135.5;260/29.6 RB, 29.6 WA

[56] References Cited UNITED STATES PATENTS 3,278,333 10/1966 Titzmann et al 117/138.8 3,190,765 6/1965 Yuan 1 17/140 X 3,424,604 l/l969 Fukushima et al. 117/11 I 3,507,675 4/1970 Noda et a1. 1 17/1 1 2/1970 Knibbe et al. 117/163 X 3,494,781 3,040,002 6/1962 Aldridge 260/853 x FOREIGN PATENTS OR APPLICATIONS 626,893 9/1961 Canada 1,128,989 1/1957 France ll7/D1G. 7

Primary Examiner-William D. Martin Assistant ExaminerSadie 'L. Childs Attorney, Agent, or Firm-James E. Bryan [57] ABSTRACT This invention relates to a process for the manufacture of chemically bonded, textile sheet material based on synthetic fibers, in which a polymer material in the form of a solution or dispersion is incorporated in the flexible textile sheet material and the polymer material is then coagulated, which comprises impregnating the textile sheet material containing synthetic fibers with a liquid binder system containing (a) a liquid aqueous dispersion of an elastomer, (b) a liquid aqueous solution of a hydrophilic polymer, and (c) a liquid aqueous emulsion of a long-chain aliphatic monoisocyanate and/or diisocyanate, or an aqueous dispersion of an ethylene imine reaction product of a monoisocyanate and/or a diisocyanate; heating the textile sheet material to the coagulating temperature of the elastomer; further heating the impregnated textile sheet material to a temperature in excess of 100C, but below the softening temperature of the fibers contained in the textile sheet material; treating the sheet material with a washing liquid; and drying the sheet material.

20 Claims, 1 Drawing Figure PATENTEDFEBWQH V 379L849 V mvan'roas KLAUS-DIETER HAMMER HERBERT PORRMANN ATTORNEY PROCESS FOR THE MANUFACTURE OF A CIIEMICALLY BONDEDTEXTILE SHEET MATERIAL BASED ON SYNTHETIC FIBERS AND HAVING A HIGH WATER VAPOR ABSORPTION CAPACITY This invention relates to a process for the manufacture of a chemically bonded textile sheet material based on synthetic fibers and having a high degree of water vapor absorption, in particular a chemically bonded fiber fleece made of synthetic fibers which is distinguished by a high water vapor absorption capacity.

The invention is particularly concerned with a continuous process of this type. Further, the invention relates to a chemically bonded textile sheet material containing synthetic fibers, in particular a fiber fleece, of high water vapor absorption capacity, which is prepared by this process.

A process for chemically bonding a fiber fleece is known, by which a dispersion or a solution of synthetic material is incorporated in the fleece and the polymer contained in the dispersion or solution is caused to coagulate. The polymer is deposited in the interior of the fleece, thus bonding the individual fibers of the fleece.

By this known process, the mechanical strength of the fleece may be improved by the chemical binder incorporated therein. A fiber fleece bonded in this manner has a very low water vapor absorption capacity, however. Although, due to its chemical bonding, the strength of the fleece is sufficient for use as a base material for the production of synthetic leather, the leather substitute produced from such a material is inferior to natural leather because it has a much lower water vapor absorption than natural leather. The water vapor absorption capacity of natural leather is of particular significance for the comfortable feeling experienced when wearing shoes or garments made of leather or using leather-upholstered articles. The fiber fleeces produced by the known processes are water-repellent, but they do not comply with the requirements as to water vapor absorption capacity made of base materials to be processed into shoe uppers, garments, or upholstery materials.

Leather is substantially water-impermeable and water vapor absorptive. For this reason, the same combination of qualities is desired from a leather substitute.

A fleece bonded by another known process with a chemical binder of hydrophilic character has the disadvantage that the binder is deposited in compact form in the interior of the fleece. In spite of the hydrophilic character of the chemical binder used, the water vapor absorption capacity achievable with such fleeces is insufficient, because the structure of the binder contained in the fleece is free from or poor in capillaries or pores.

The present invention provides a process for the manufacture of a chemically bonded textile sheet material which does not have the disadvantages of known processes and enables the manufacture of chemically bonded textile sheet materials based on synthetic fibers which are distinguished by a good water vapor absorption capacity. In the present process for the manufacture of a chemically bonded textile sheet material based on synthetic fibers, as a first process step, the textile sheet material containing synthetic fibers is impregnated with a liquid binder containing a. a liquid aqueous dispersion of an elastomer,

b. a liquid aqueous solution ofa hydrophilic polymer,

and

c. a liquid aqueous emulsion ofa long-chain aliphatic monoisocyanate and/or diisocyanate, or an aqueous dispersion of an ethyleneimine reaction product of a monoisocyanate and/or a diisocyanate. As a second process step, sufficient heat to reach the coagulation temperature of the elastomer is caused to act upon the textile sheet material. As a third process step, sufficient heat is caused to act upon the impregnated textile sheet material to heat it to a temperature above C, but below the softening temperature of the fibers contained in the textile sheet material. As a fourth process step, the textile sheet material is treated with a washing liquid, and, as a fifth process step, the textile sheet material is dried by the action of heat.

The liquid binder used for bonding the fleece will be designated in the following as a liquid binder system.

In principle, any aqueous dispersion of an elastomer may be used as the aqueous elastomer dispersion, but those based on polyacrylates or polyvinyls are preferred, particularly copolymers of diene and vinyl monomers. lt is particularly advantageous, however, to use elastomer dispersions the elastomers of which contain reactive groups, such as COOl-l, NH, NH OH or SH groups. Elastomer dispersions containing free COOH groups are of particular advantage. Elastomers of such structure are preferred because these groups enable them to react with the other solid components of the liquid binder system, thus causing the substance bonding the fibers to assume a three-dimensionally cross-linked structure. Synthetic rubber based on a butadiene-acrylonitrile-methacrylic acid copolymer, e.g., PERBUNAN 3405, a product of Farbenfabriken Bayer, Leverkusen, Germany, has proved to be a particularly suitable aqueous elastomer dispersion.

The expression elastomers means polymers as defined on page 154 of Textbook of Polymer Chemistry by Billmeyer, N.Y., 1967.

Suitable hydrophilic components of the liquid binder system are water-soluble polymers, e.g., cellulose derivatives, such as carboxymethyl cellulose or cellulose ethers, or starch; polyvinyl alcohol is particularly advantageous.

Thus the hydrophilic component of the liquid binder system is a polymer which possesses a plurality of groups having a hydrophilizing effect.

Suitable aqueous isocyanate emulsions are those based on aliphatic monoisocyanates and/or diisocyanates having carbon chains with 14 to 25 carbon atoms, preferably between 16 and 20 carbon atoms. These isocyanates may be branched or straight-chained, and mixtures of branched isocyanates with straight-chained isocyanates may also be used. The ethylene imine isocyanate reaction products (ethylene ureas) are applied in the form of aqueous dispersions. They are prepared by the reaction of the above described aliphatic isocyanates with ethylene imine. When diisocyanates are used, one or two NCO groups react with the ethylene imine. The dispersion may also consist of a mixture of several ethylene imine reaction products of monoisocyanates and/or diisocyanates. It is of particular advantage to use the isocyanates of this type in a dis guised form. Aliphatic isocyanates of this structure are distinguished by the fact that they react very slowly with the dispersing agent, even when they are stored for I a prolonged period of time in the aqueous emulsion.

Even at the boiling temperature of the dispersed substance, the reaction between water and isocyanate is not noticeably accelerated. This behavior of the aliphatic isocyanates mentioned may be explained by their hydrophobic character. The use of aqueous dispersions of ethylene imine/ isocyanate reaction products as a component of the binder liquid is of particular advantage, octadecyl ethylene urea being preferred. The dispersed substance in the emulsion or dispersion represents the hydrophobic, fat-like element within the liquid binder system. Due to their hydrophobic character, the aliphatic isocyanates or their ethylene imine reaction products form an integral component of the liquid binder system or the complex binder system and are primarily responsible for the softening of the bonded textile sheet material and its hydrophobic properties, suppleness and handling characteristics.

The readily water-soluble hydrophilic polymer substance contained in the liquid binder system is of good compatibility with the dispersed elastomer. The watersoluble hydrophilic polymer has a stabilizing effect upon the elastomer dispersion. When polyvinyl alcohol is used as the water-soluble hydrophilic polymer, this has an accelerating effect upon the vulcanization of synthetic rubber, which may be of interest when such vulcanization is intended.

in the liquid binder system, the elastomer, the watersoluble hydrophilic polymer, and the aliphatic isocyanate are present in such quantities that the entire liquid binder system has a solids content of 30 to 60 percent by weight, preferably between 40 and 50 percent by weight, calculated on the total weight of the liquid binder system.

The solids component of the liquid binder system contains 40 to 98 percent by weight, preferably 60 to 90 percent by weight calculated on the total weight of solids of polymer material.

Fifty to 98 percent by weight, preferably 60 to 80 percent by weight, of the polymer component of the solids contained in the liquid binder system is elastomer material, whereas the proportion of water-soluble hydrophilic polymer substance is in the range from 1 to 40 percent by weight, preferably 5 to 25 percent by weight.

One to 40 percent by weight, particularly 5 to 25 percent by weight, of the weight of the solids component of the liquid binder system is aliphatic monoand/or diisocyanates.

The coagulation temperature is the temperature above which coagulation of the dispersed elastomer begins. It is a requirement of the present invention that the coagulation temperature is below that temperature at which chemical reactions take place between the various components of the liquid binder system.

In the present invention, chemical binders are chemicals which cause a physical-mechanical bond between the fibers of the fleece. Thus, the liquid binder system itself is not capable of bonding the fleece mechanically. The substance capable of mechanically bonding the fleece, which is present in the interior of the fleece after the third process step, will be designated as a Tbinder complex. The binder complex is distinguished from the liquid binder system and the individual solid components thereof, respectively, by the fact that, due to the chemical reactions occurring between the components of the liquid binder system in the course of the present process, the binder complex is substantially insoluble in water. I

The liquid bindersystem is prepared by mixing an aqueous dispersion of an elastomer with asolids content of 30 to percent by weight, preferably of 40 to 60 percent by weight, calculated on the total weight of the dispersion, with (a) an aqueous solution of a hydrophilic polymer which differs in its chemical structure and its physical properties from the elastomer, the solution having a solids content of 5 to 40 percent by weight, preferably l0 to 20 percent by weight, calculated on the total weight of the solution, and (b) an aqueous emulsion of an aliphatic isocyanate or an aqueous dispersion of a reactive ethyleneimine reaction product of such isocyanate, in which the solids proportion ranges from 10 to percent, preferably from 40 to 60 percent by weight, calculated on the total weight of the emulsion or dispersion, the said dispersion, solution and emulsion, or dispersion, as the case may be, being mixed in such proportions that the resulting liquid mixture has the above mentioned total solids content and that the individual solid components are present in the quantities stated. 9

In connection with the statements referring to the solids content of the liquid binder system, the dispersed substance in the emulsion is also regarded as a solid.

During the third process step, the heat action by which the binder system is heated to a temperature above C, but below the softening temperature of the fibers of the textile sheet material, causes a reaction between the isocyanate, or the reactive ethyleneimine reaction product of the isocyanate, and the hydrophilic water-soluble polymer of the liquid binder system resulting in a reaction product which is insoluble in water and organic solvents. When the elastomer contains groups capable of reaction with isocyanate groups, the temperature conditions prevailing during this process step cause an additional cross-linking of the isocyanates, and/or the reaction product formed from the isocyanate and the hydrophilic component, with the carboxyl groups which may be present in the polymer chains of the elastomer.

When the reaction takes place between an isocyanate group and a carboxyl group of the elastomer, CO is liberated, and the gas promotes the formation of pores in the binder.

The NCO groups of the isocyanate are protected by reaction of'the isocyanates with ethylene imine, phenol, sodium hydrogen sulfite, and the like. Under the influence of heat, the reaction product is split again, and the NCO group is liberated. The disguised isocyanates are also employed in the form of aqueous emulsions and are of good compatibility with the aqueous elastomer dispersions.

Textile, sheet-like materials based on synthetic fibers are woven, knitted, or felt-like webs consisting of synthetic fibers. Fiber fleeces, in particular matted fiber fleeces, are preferred, and most of all those containing a proportion of heat-shrinkable synthetic fibers.

Needled matted fiber fleeces consisting of or containing synthetic fibers, at least part of which are heatshrinkable, are particularly suitable for performing the process of the invention. Fiber fleeces consisting of mixtures of at least two chemically different synthetic fibers, preferably predominantly of polyester fibers and a smaller proportion of polyamide fibers, are preferred. In this case, all the fibers of the same chemical structure may be heat-shrinkable, or heat-shrinkable synthetic fibers may be present together with fibers of the same chemical structure which are not capable of shrinking under the influence of heat.

The titer of the fibers of the fleece is preferably in the range of 0.8 to 3 denier. The weight per unit area of suitable fiber fleeces is preferably in the range of 150 to 500 g per square meter. Needled fiber fleeces are advantageously needled at a rate of about 400 stitches per cm The liquid binder system advantageously may contain a vulcanization accelerator, e.g., zinc oxide or sulfur compounds known as vulcanization accelerators, such as VULKACIT a product of Farbenfabriken Bayer, Leverkusen, Germany.

The process is performed as follows:

A textile sheet material, preferably a fiber fleece, and in particular a needled matted fiber fleece, is impregnated by immersion in a trough containing the liquid binder system. The impregnated fleece is then removed from the trough and squeezed out. Then the impregnated fleece is heated to the coagulation temperature of the elastomer contained in the liquid binder system, but not sufficiently to initiate chemical reactions between the solid components of the liquid binder system or to soften the fibers of the fleece. Advantageously, this heat action is caused by irradiation of the fleece with an infra-red radiator. The coagulation temperature is in the range of to 80C., especially between and 50C.

After complete coagulation of the elastomer, the fleece is introduced into a heating chamber supplied with hot air at a temperature between 100 and 180C. In the heating chamber, the fleece is heated to a temperature above 100C., but below the softening temperature of the synthetic fibers, preferably to a temperature ranging from 120 to 180C. The heating time ranges from 2 to 30 minutes and is preferably between 5 and 15 minutes. At this temperature and within the period of time stated, the above mentioned chemical reactions take place between the reactive components of the binder system contained in the interior of the fleece.

After leaving the heating chamber, the fleece is washed first with hot water, then with cold water, and then dried, e.g., in a drying oven fed with hot air at 120 to 150C.

A continuous performance of this process is of particular advantage.

By the process of the invention, a chemically bonded textile sheet material is produced which possesses the advantages of the materials bonded according to known processes, but is without their disadvantages. In addition to polymer chains, the complex binder incorporated between the fibers of the textile sheet material contains high molecular weight substances with branched chains, which are of hydrophobichydrophilic character and contain urethane groups. These substances are formed by the above mentioned chemical reactions of the solid components of the liquid binder system during the third process step. After the performance of the third process step, during which the above mentioned chemical reactions between the reactive solids of the liquid binder system occur, the

formerly liquid binder system is designated as complex binder system.

The complex binder system produced according to the present invention is distinguished by its structure, which is characterized by a large number of pores and capillaries. The porosity of the complex binder system may be advantageously increased by using an aqueous dispersion of a synthetic rubber based on a butadieneacrylonitrile-methacrylic acid copolymer (e.g., PER- BUNAN""N-Latex, a product of Farbenfabriken Bayer, Leverkusen, Germany) as the aqueous elastomer dispersion and vulcanizing it with the addition of zinc oxide. By the formation of a zinc salt between the carboxyl groups of neighboring polymer chains, the chains become cross-linked. This salt formation does not include all the carboxyl groups of the elastomer based on the copolymer. Due to the presence of the aqueous dispersion of a long-chain aliphatic isocyanate, preferably stearyl isocyanate, or of monoethylene urea and/or diethylene urea, together with the aqueous solution of the hydrophilic polymer, preferably polyvinyl alcohol or partially saponified polyvinyl acetate, in the liquid binder system, chemical reactions taking place in the course of the third process step cause not only the formation of reaction products of isocyanate and polyvinyl alcohol, but also of reaction products of isocyanate or monoor diethylene urea and carboxyl groups of the above mentioned synthetic rubber which had not been bonded by salt formation during vulcanization of the elastomer. During the latter reaction, CO is liberated. This increases the porosity of the complex binder system within the fleece and removes its tackiness.

Alternatively, the carboxyl groups of the synthetic rubber may react with the OH groups of the polyvinyl alcohol and/or the OH group-containing reaction product of polyvinyl alcohol and isocyanate, with ester formation. This reaction promotes the formation of a three-dimensional network of complex binder within the fleece. When the third process step is performed at a relatively high reactiontemperature, polyvinyl alcohol molecules combine into relatively long, waterinsoluble molecule chains and form ethers. This reaction is preferably conducted at a temperature in the range of to C.

The water vapor absorption capacity and the degree of hydrophobic property of the fleece can be varied within wide limits, not only by the absolute quantities employed of the chemical substances making up the complex binder system, but also by the quantitative ratio of water-soluble hydrophilic components to hydrophobic components and by the reaction conditions prevailing. As an example, with a given quantity of polyvinyl alcohol, the water vapor absorption capacity is increased by adding smaller quantities of stearyl isocyanate or by heating to higher temperatures during the third process step, while at the same time the hydrophobic character of the complex binder system becomes less pronounced. Vice versa, when the quantity of polyvinyl alcohol in the binder system remains constant, the degree to which the fleece is made hydrophobic by the binder increases with an increasing quantity of stearyl isocyanate, while at the same time the water vapor absorption capacity of the complex binder system is reduced.

The advance in the art achieved by the process of the invention resides in the fact that the process for bonding the fiber fleece can be performed in a manner which is economical and technically inexpensive, and the fiber fleece bonded in accordance with this process is distinguished favorably from fiber fleeces bonded by conventional methods by its high water vapor absorption in combination with its water-repellent properties.

The water vapor absorption capacity of the fiber fleece bonded by the process of the invention may be varied from 1 to percent, depending on the quantities of the different substances contained in the liquid binder system and the reaction conditions prevailing during the third process step.

The water vapor absorption is determined as follows: A sample of the fleece of 10 cm length and 5 cm width is conditioned by storing it for 24 hours at a relative humidity of 65 percent and a temperature of C., and then weighed. After weighing, the sample is stored again for 24 hours at a relative humidity of 100 percent and a temperature of C, and then weighed again. The resulting difference in weight is calculated in percent and termed water vapor absorption capacity.

By the process of the invention, a number of related properties of the bonded fleece may be advantageously altered.

' It is an essential advantage that a fiber fleece intended for processing into a leather substitute can be given properties by the present invention which displace the characteristics of the leather substitute prepared from this fleece towards those of leather. The fleece produced by the present process is not only water-repellent and simultaneously highly water-vapor absorptive, but it is improved also in other respects. During the coagulating process, the high-molecular weight hydrophilic compounds added are present in the binder in the swollen state. Under the influece of the heat action following during the third process step, the hydrophilic compounds are deswollen and the water which is evaporated causes thecomplex binder system to assume a highly porous structure. This effect is enhanced by a chemical reaction which causes the formation of branched molecules which increase the distance between the chain molecules. For a high water vapor absorption capacity of the complex binder system, not only hydrophilic groups, but also pores and capillaries within the complex binder system are required. One of these prerequisites alone does not cause a high water vapor absorption. The high gas permeability of the fleece bonded according to the present process is also related to the substantially increased porosity of the complex binder system. As mentioned above, this is of particular importance for the feeling of comfort when wearing shoes and garments made of leather substitutes based on these fleeces.

The long-chained fat-like isocyanates or the monoethylene ureas and/or diethylene ureas contained in the complex binder system render the bonded fleece soft and supple. The degree of flexibility can be adjusted by the quantities of these substances employed. The longchained aliphatic isocyanate or the monoethylene and- /or diethylene urea is firmly incorporated in. the complex binder system by chemical reaction, which means that it does not migrate under normal conditions. The process of'the invention produces a complex binder system which has a high degree of cross-linking and is of three-dimensional network structure.

Due to the softening effect of the isocyanates contained in the complex binder system, however, the

cross-linkage has no adverse effects. Since the fleece bonded according to the present invention is not tacky, it can be ground without difficulties. The surface thereof does not become sticky or smeary by grinding.

By mixing the aqueous elastomer dispersion and the aqueous emulsion of the aliphatic isocyanate, or the aqueous dispersion of the monoethylene and/or diethylene urea, with the aqueous solution of the hydrophilic polymer and by the above described cross-linking of the various components by chemical reactions taking place during the performance of the present process, a complex binder system is produced in the interior of the fleece which is no longer swellable, or only insignificantly swellable, in water and in organic solvents. This incapability of swelling of the complex binder system within the fleece causes further important effects when a top coating is applied to the fleece containing the complex binder system. Normally, polyurethanes dissolved in dimethyl formamide are applied to the fleece to form a top coating. Since the fleece bonded by the present process is no longer swellable in dimethyl formamide or a mixture of dimethyl formamide and water, the air contained in the cells and fine capillaries in the interior of the fleece is no longer squeezed out of the fleece during the coating operation. In this manner, the formation of bubbles during the application of the top coating is avoided.

In the fleeces produced according to the process of the invention, the structure of the raw fleece is no longer discernible as surface irregularities of the top coating. The surface irregularities (needle structure) are due to differences in the density of the fleece, i.e., different binder contents in the fleece.

The accompanying drawing shows, in cross-section, a flow diagram of a continuous process according to the invention.

A web of synthetic fiber fleece 2 is drawn off of a magazine roll 1 and continuously introduced, over a guide pulley 3, into an open trough 4 filled with a liquid 5 consisting of the liquid binder system, so that it becomes impregnated with the liquid binder system. Numeral 6 designates a supply reservoir for the liquid binder system 5. The impregnated fleece is then withdrawn from the bath and squeezed out by means of a pair of squeeze rolls 7. In this manner, any excess of liquid binder is removed. The impregnated web of fleece is then conducted past a heat radiator 8, e.g., a ceramic infra-red radiator, in such a manner that the radiation acts upon the surface of the web 2. By the irradiation of the fleece, the liquid binder system contained in the interior of the fleece is heated to its coagulation temperature and the elastomer is caused to coagulate. The web 2 then passes a number of further guide rolls 3 and is introduced into a heating chamber 9. Numerals l0 and 1 l designate the inlet and outlet slots of the heating chamber. The heating chamber 9 is heated with hot air fed into the heating chamber through the inlet pipe 12 and leaving it through the outlet pipe 13. The temperature prevailing in the heating chamber initiates the chemical reactions between the solid components of the liquid binder system contained in the fleece. This means that the complex binder system capable of bonding the fleece is formed at this stage of the process. After leaving the heating chamber through the outlet slot 11, the web is introduced into a Foulard bath 14. This is an open container which is subdivided into sev- 9. eral compartments 16 by means of a number of partition walls extending vertically upwards from the bottom of the container. The compartments 16 are filled with a washing liquid 17. The washing liquid within the various compartments has a temperature gradient such that the washing liquid in the first compartment entered by the fleece is hot, whereas the liquid at the discharge end of the Foulard bath is cold. Numeral- 18 designates a pair of squeeze rolls.

The washed web of fleece is then conducted through a drying oven 19 supplied with hot air. The hot air enters the drying oven through the inlet opening 20 and leaves it through the outlet opening 21. Numeral 22 designates the inlet slot through which the web enters the drying oven and 23 is the outlet slot. The web of fleece bonded by the complex binder system is then wound upon a magazine roll 24.

The invention will be further illustrated by reference to the following specific examples:

EXAMPLE 1 The liquid binder system is prepared as follows:

14.8 g of polyvinyl alcohol (e.g., MOWlOU N -88, a product of Farbwerke Hoechst A.G., Frankfurt/Main, Germany) are dissolved in 258.0 g of water.

Thissolution is thoroughly mixed with an aqueous emulsion of the following composition:

29.60 g of water 24.90 g of stearyl isocyanate, and

12.45 g of a 40 percent by weight solution of an electroneutral fatty acid condensation product (e.g., EMULV1N" W, a product of Farbenfabriken Bayer, Leverkusen, Germany) as an emulsifier. The liquid thus obtained is added, while vigorously stirring, to a dispersion of the following composition:

1. 594 g of a 50 percent by weight aqueous dispersion of a' butadiene-acrylonitrile-methacrylic acid copolymer (e.g., PERBUNAN N-Latex, 3405-M, a product of Farbenfabriken Bayer, Leverkusen, Germany),

2. 29.7 g of a 50 percent by weight aqueous dispersion of active zinc oxide in an aqueous solution of a salt of a naphthalene sulfonic acid condensation product (e.g., VULTAMOL a product of Badische Anilin und Soda-Fabrik A.G., Ludwigshafen, Germany), 1 I

3. 14.8 g of a 20 percent by weight aqueous dispersion of an electroneutral fatty acid condensation product (e.g., EMULV1N."W, a product of Farbenfabriken Bayer, Leverkusen, Germany),

1.33 g of a polysiloxane (e.g., COAGU- LANT"WS, a product of Farbenfabriken Bayer, Leverkusen, Germany), and

5. 13.0 g of a 50 percent by weight aqueous dispersion of a black pigment (e.g., MELUSTRAL""- dyestuff, a product of Farbwerke Hoeschst A. G., Frankfurt/Main, Germany).

A matted fiber fleece consisting of polyethylene terephthalate fibers of 1.3 denier, consolidated by needling (400 stitches per cm and having a weight per unit area of 250 g per m is impregnated with the liquid binder system of the above composition to the point of saturation in a Foulard impregnating bath, then withdrawn from the bath, and squeezed out.

The impregnated fleece is then conducted past infrared radiators the radiation of which is directed onto both surfaces of the fleece, and heated to a temperature between 38 and 40 C. This temperature corresponds to the coagulation temperature of the liquid binder system.

The fleece is then introduced into a heating chamber supplied with hot air at 150 C. In this chamber, the fleece is maintained at a temperature of 150 C. for 15 minutes.

The fleece is then washed for 5 minutes in a Foulard bath with water at a temperature of C. and then thoroughly rinsed with cold water. For drying, the fleece is treated with hot air at C.

The bonded fleece has a water vapor absorption capacity of 10 percent by weight and a binder content of 60 percent by weight, calculated on the total weight of the fleece. The bonded fleece is difficultly wettable with water and absorbs very little water. The bonded fleece may be used as supporting material for the pro duction of synthetic leather.

EXAMPLE 2 A liquid binder system of the composition stated in Example I is prepared. The process is performed as in Example 1, except that the fleece is maintained for 20 minutes at a temperature of C. in the heating chamber.

The water vapor absorption capacity of the bonded fleece is 12.8 percent by weight and its binder content is 62 percent by weight, calculated on the total weight of the fleece. Wettability with water and absorptivity towards water and suitability of the bonded fleece are the same as stated in Example 1.

EXAMPLE 3 Other than in Example 1, the aqueous emulsion used for the preparation of the liquid binder system has the following composition: 12.5 g of stearyl isocyanate, 6.2 g of a 40 percent by weight aqueous dispersion of an electroneutral fatty acid condensation product (e.g., EMULV1N W, a product of Farbenfabriken Bayer, Leverkusen, Germany) and 14.8 g of water.

The process conditions differ from those of Example 1 in that the fleece is kept for 10 minutes at a temperature of C. in a heating chamber supplied with air at 180 C. The bonded fleece has a water vapor absorption capacity of 14.5 percent by weight and its binder content is 60 percent by weight, calculated on the total weight of the fleece. Wettability with water and water absorption capacity, as well as the suitability of the fleece, are the same as stated in Example 1.

EXAMPLE 4 As a modification of Example 3, the fleece is maintained in the heating chamber for 10 minutes at a temperature of 150 C.

The water vapor absorption capacity of the bonded fleece thus produced is 6.2 percent by weight, and its binder content is 61 percent by weight, calculated on the total weight of the fleece. The bonded fleece is difficultly wettable with water and its water absorption capacity islow. The bonded fleece may be used for the purpose stated in Example 1.

EXAMPLE 5 Three separate liquids, viz. liquids a, b, and c, are prepared which have the following compositions, respectively:

a. 482.0 g of an acrylate copolymer (e.g., Acrylate- Latex-Versuchs-product KA 8059, 40 percent by weight aqueous dispersion, a product of Farbenfabriken Bayer, Leverkusen, Germany),

9.4 g of a polysiloxane (e.g., Coagulant WS, a product of Farbenfabriken-Bayer, Leverkusen, Germany),

38.4 g of water,

9.4 g of an urea-formaldehyde pre-condensate (e.g., FIXAPRET 140, a product of Badische Anilin-und Sodafabrik A. G., Ludwigshafen, Germany),

38.4 g of a fatty acid/alkaline earth metal salt (e.g., GADALAN FF, 10 percent by weight aqueous dispersion, a product of Dr. Quehl & Co. GmbH., Speyer, Germany),

9.4 g of titanium dioxide (e.g., BAYER TITAN R-FK- D, a product of Farbenfabriken Bayer, Leverkusen,

Germany), dispersed in 10 parts by weight of a percent aqueous solution of a salt of a naphthalene sulfonic acid condensation product (e.g., VUL- TAMOL," a product of Badische Anilinund Soda- Fabrik A. G., Ludwigshafen, Germany), and 38.4 g of ammonium chloride, percent aqueous solution. b. 16.5 g of polyvinyl alcohol (e.g. MOWIOIJ N 30-88, a product of Farbwerke Hoechst A. G., Frankfurt/Main, Germany), and 1 275.0 g of water. 6. 27.0 g of stearyl isocyanate, 13.5 g of a 40 percent solution of an electroneutral fatty acid condensation product (e.g., EMULVIN" W, a product of Farbenfabriken Bayer, Leverkusen, Germany, 6.4 g of a polysiloxane (e.g., COAGULANT""WS, a product of Farbenfabriken Bayer, Leverkusen, Germany), and 54.0 g of water.

The aqueous emulsion c is added to the aqueous solution b with vigorous stirring.

The resulting liquid is then mixed with the dispersion a while stirring, thus producing the liquid binder system.

A fleece similar to the one described in Example 1 is impregnated as in Example 1 with the liquid binder system prepared as described above. The performance of the process is as described in Example 1, with the exception that, for coagulation of the elastomer in.the liquid binder system, the impregnated fleece is heated to 43 C. when it passes the infra-red radiators. In a heating chamber heated with air at 160 C., the fleece is kept for 10 minutes at a temperature of 160 C. Then, it is washed for 6 minutes with water at 85 C., repeatedly rinsed with cold water, and finally dried by the action of hot air.

The fleece thus produced has a water vapor absorption capacity of 8.2 percent by weight and a binder content of 62 percent by weight, calculated on the total weight of the fleece.

The bonded fleece cannot be easily wetted with water and its water absorption capacity is low. It is suitable for the purpose stated in Example 1.

EXAMPLE 6 with hot air at 160 C.

The process of Example 5 is modified in that the liq- The finished bonded fleece has a water vapor absorptivity of 11.6 percent by weight and a binder content of 59 percent by weight, calculated on the total weight of the fleece.

The fleece cannot be easily wetted with water and its water absorption capacity is low. It is also suitable for the purpose stated in Example 1.

EXAMPLE 7 For the preparation of the liquid binder system, 12.5 g of polyvinyl alcohol (e.g., MOWlOU N 30-88, a product of Farbwerke Hoeschst A.G., Frankfurt/Main, Germany) are dissolved in 187.5 g of water. This solution is then intimately mixed with an aqueous dispersion consisting of:

82.5 g of water 72.75 g of a 22 percent by weight aqueous dispersion of octadecyl ethylene urea (e.g., PRIMENIT LD, a product of Farbwerke Hoeschst A.G., Frankfurt/Main, Germany), and

8.25 g of a 26 percent by weight aqueous solution of an electroneutral fatty acid condensation product (e.g., EMULVlN" W, a product of Farbenfabriken Bayer, Leverkusen, Germany).

The liquid produced by mixing is then added, while intensively stirring, to a dispersion of the following composition:

500.0 g of a 50 percent by weight aqueous dispersion of a butadiene-acrylonitrile-methacrylic acid copolymer (e.g., PERBUNAN NT-Latex, a product of Farbenfabriken Bayer, Leverkusen, Germany),

35.75 g ofa 50 percent by weight dispersion of active zinc oxide in an aqueous solution of a salt of a naphthalene sulfonic acid condensation product (e.g., VULTAMOL", a product of Badische Anilinund Soda-Fabrik A.G., Ludwigshafen, Germany),

7.5 g of a 26 percent solution of an electroneutral fatty acid condensation product (e.g., EMULVlN"" W, a product of Farbenfabriken Bayer, Leverkusen, Germany),

82.5 g of water,

0.5 g of colloidal sulfur,

0.5 g of a vulcanization accelerator (e.g., VULK- AClT"LDA, a product of Far benfabriken Bayer, Leverkusen, Germany),

3.75 g of a vulcanization accelerator (e.g., VULKACIT"" ZM, a product of Farbenfabriken Bayer, Leverkusen, Germany),

12.5 g of titanium dioxide,

3.0 g of a 40 percent solution of an electroneutral fatty acid condensation product (e.g., EMUL- VlN"""W, a product of Farbenfabriken Bayer, Leverkusen, Germany),

6.5 g of a polysiloxane (e.g., COAGULANT""WS, a product of Farbenfabriken Bayer, Leverkusen, Germany), and 2.7 g of a 50 percent aqueous dispersion of a black pigment (e.g., "MELUSTRAL -dyestuff, a product of Farbwerke Hoeschst A.G., Frankfurt/Main,

Germany). I A matted fibre fleece as used in Example 1 is impregnated with this liquid binder system in a Foulard bath, squeezed off, and then further treated as described in Example 1.

The bonded fibre fleece has a water vapor absorption capacity of 12 percent by weight, and its binder content is 61 percent by weight, calculated on the total weight of the fleece.

It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. A process for the manufacture of chemically bonded, textile sheet material based on synthetic fibers, in which a polymer material in the form of a solution or dispersion is incorporated in the flexible textile sheet material and the polymer material is then coagulated, which comprises impregnating the textile sheet material containing synthetic fibers with a liquid binder system containing a. a liquid aqueous dispersion of an elastomer,

b. a liquid aqueous solution of a hydrophilic polymer,

and

c. A liquid aqueous emulsion of a long-chain aliphatic monoisocyanate or diisocyanate having a chain length of 14 to 25 carbon atoms, or mixtures thereof, or an aqueous dispersion of an ethylene imine reaction product of a mono-isocyanate or a diisocyanate or mixtures thereof; heating the textile sheet material to the coagulation temperature of the elastomer; further heating the impregnated textile sheet material to a temperature in excess of 100C. but below the softening temperature of the fibers contained in the textile sheet material; treating the sheet material with a washing liquid; and drying the sheet material. 1

2. A process according to claim 1 in which the textile sheet material is dried by heating.

3. A process according to claim 1 in which'the liquid binder system contains about 50 to 98 percent by weight of aqueous elastomer dispersion, calculated on the total weight of the liquid binder system.

4. A process according to claim 1 in which theelastomer employed is a butadiene-acrylonitrile-methacrylic acid terpolymer.

5. A process according to claim 1 in which the liquid binder system contains an aliphatic isocyanate having a chain length of 16 to 20 carbon atoms.

6. A process according to claim 1 in which the liquid binder system contains stearyl isocyanate.

7. A process according to claim 1 in which the liquid binder system contains a reactive ethylene imine reaction product of a monoisocyanate or a diisocyanate or mixtures thereof.

8. A process according to claim 1 in which the liquid binder system contains octadecyl ethylene urea.

9. A process according to claim I in which polyvinyl alcohol is employed as the water-soluble hydrophilic component of the liquid binder system.

10. A process according to claim 1 in which the liquid binder system contains an aqueous dispersion of a butadiene-acrylonitrile-methacrylic acid terpolymer, an aqueous solution of polyvinyl alcohol, and an aqueous emulsion of stearyl isocyanate.

11. A process according to claim 1 in which the liquid binder system consists of an aqueous dispersion of a butadiene-acrylonitrile-methacrylic acid terpolymer, an aqueous solution of polyvinyl alcohol, and an aqueous dispersion of octadecyl-ethylene-urea.

12. A process according to claim 1 in which a matted fiber fleece of synthetic fibers is employed.

13. A process according to claim 1 in which a matted fiber fleece of polyethylene terephthalate fibers is employed.

14. A process according to claim 1 in which a needled matted fiber fleece of polyethylene terephthalate fibers is employed.

15. A process according to claim 1 in which a needled matted fiber fleece based on polyethylene terephthalate fibers is employed having a weight per unit area of 250 grams per m 16. A process according to claim 1 in which a matted fiber fleece is employed which contains more than 50 percent by weight of polyethylene terephthalate fibers and less than 50 percent by weight of polyamide fibers.

17. A process according to claim 1 in which masked isocyanates are employed.

18. A process according to claim 1 in which, during the third process step, the textile sheet material is subjected for 2 to 30 minutes to a temperature between and C.

19. A chemically bonded, textile sheet material, based on synthetic fibers, produced according to the process of claim 1.

20. A process according to claim 1 in which the liquid binder system contains an elastomer having at least one free group selected from the group consisting of COOH, OH, NH and SH groups.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,791,849 r Dated February 12, 1974 Inventor(s) Klaus-Dieter Hammer et al It is-cert-i'fied that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 9, line 58, "Hoeschst" should read Hoechst Column 12 lines 23 and 31, "Hoeschst" should read Hoechst each occurrence. I

Column 14, the last line should read as follows; COOH, OH NH, and SH groups Signed and sealed this 20th day of August 197A.

(SEAL) Attest:

MccoY M. GIBSON, JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents F ORM PO-lOSO 10-69) USCOMM-DC OOSIG-PGD t u.s. Govumunn "mime orrlc: lul o-au-au.

Claims

2. A process according to claim 1 in which the textile sheet material is dried by heating.
3. A process according to claim 1 in which the liquid binder system contains about 50 to 98 percent by weight of aqueous elastomer dispersion, calculated on the total weight of the liquid binder system.
4. A process according to claim 1 in which the elastomer employed is a butadiene-acrylonitrile-methacrylic acid terpolymer.
5. A process according to claim 1 in which the liquid binder system contains an aliphatic isocyanate having a chain length of 16 to 20 carbon atoms.
6. A process according to claim 1 in which the liquid binder system contains stearyl isocyanate.
7. A process according to claim 1 in which the liquid binder system contains a reactive ethylene imine reaction product of a monoisocyanate or a diisocyanate or mixtures thereof.
8. A process according to claim 1 in which the liquid binder system contains octadecyl ethylene urea.
9. A process according to claim 1 in which polyvinyl alcohol is employed as the water-soluble hydrophilic component of the liquid binder system.
10. A process according to claim 1 in which the liquid binder system contains an aqueous dispersion of a butadiene-acrylonitrile-methacrylic acid terpolymer, an aqueous solution of polyvinyl alcohol, and an aqueous emulsion of stearyl isocyanate.
11. A process according to claim 1 in which the liquid binder system consists of an aqueous dispersion of a butadiene-acrylonitrile-methacrylic acid terpolymer, an aqueous solution of polyvinyl alcohol, and an aqueous dispersion of octadecyl-ethylene-urea.
12. A process according to claim 1 in which a matted fiber fleece of synthetic fibers is employed.
13. A process according to claim 1 in which a matted fiber fleece of polyethylene terephthalate fibers is employed.
14. A process according to claim 1 in which a needled matted fiber fleece of polyethylene terephthalate fibers is employed.
15. A process according to claim 1 in which a needled matted fiber fleece based on polyethylene terephthalate fibers is employed having a weight per unit area of 250 grams per m2.
16. A process according to claim 1 in which a matted fiber fleece is employed which contains more than 50 percent by weight of polyethylene terephthalate fibers and less than 50 percent by weight of polyamide fibers.
17. A process according to claim 1 in which masked isocyanates are employed.
18. A process according to claim 1 in which, during the third process step, the textile sheet material is subjected for 2 to 30 minutes to a temperature between 120* and 180*C.
19. A chemically bonded, textile sheet material, based on synthetic fibers, produced accordinG to the process of claim 1.
20. A process according to claim 1 in which the liquid binder system contains an elastomer having at least one free group selected from the group consisting of COOH, OH, NH2, and SH groups.