Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/0002—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate
  • D06N3/0004—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the substrate using ultra-fine two-component fibres, e.g. island/sea, or ultra-fine one component fibres (< 1 denier)
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4282—Addition polymers
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/904—Artificial leather

Definitions

• a method for making an air and moisture-permeable sheet material comprising impregnating a fibrous substrate of mix-spun fibers with an impregnant comprised of a high molecular weight polymeric material having rubber-like elasticity, coagulating the impregnant, and extracting one of the polymers in the mix-spun fibers by means of a solvent which is a non-solvent for at least one other polymer in the said mix-spun fibers.
• the present invention relates to a pliable, airand moisture-permeable sheet material with a high strength and to the method of manufacturing the same.
• the invention is concerning with a sheet material which bears a striking resemblance to the natural leather in structure, external appearance, texture and touch, that is so-called synthetic leather, and with the method of preparing the same.
• the artificial leather so-called imitation leather.
• the artificial leather was made, in the early time, by coating nitrocellulose and then vinyl chloride or rubber by changing the coatings on woven fabrics.
• the artificial leather is made resembling to the natural leather in the texture by composing of the coatings and in the external appearance by pressing grain.
• the physical strength of the artificial leather depends only upon the fabric used.
• the deficiencies remaining on the natural leather are the very problems also on the synthetic leather, upon estimation of the latter.
• the novel synthetic leather should retain desirable properties of the natural leather but be free from undesirable properties of the latter.
• the dermis is the main part constituting the leather which substantally determines its qualities, the epidermis defines the external appearance, and the hypodermis, the so-called hypodermal fatty tissue, makes the characteristic back surface of the finished leather as the hide is stripped off at this part.
• the dermis is composed of collagen, and the characteristics of the leather attributable to the collagen are as follows:
• Collagen fibers, in the dermis are intertwined with all angles to the surface of the dermis to form a firm net-work.
• the collagen fibers adjacent to the papillate surface are extending in parallel to the surface of the leather and are more compact than the internal reticulating tissue and, in addition, elastic fibers spread in the interior, so that they serve for preventing the surface of the leather from crack and for imparting to the surface of the leather a grain.
• Each collagen molecule has a mild linear structure, more particularly a spherical configuration, and some molecules collect together to form, by degrees, a micelle, a fibril, a visible fiber and finally a tridimensional fiber.
• the availability of the leather is not attributable to its individual properties and features but to the excellence of the combination of the individual properties. This is a remarkable feature ofthe leather which can not be found in the other materials and, moreover, the leather, due to a natural product, has such several specific characteristics that one can not limitate.
• some defects on the leather are regarded as peculiar to the leather, but these result from the common property of the natural article. Therefore, it is essential for those skilled in the synthetic leather to surely know the advantages and defects of the natural leather, and the following items commonly may be specified as common sense.
• the advantages are, connected to the appropriate properties and Working ability for leather material for making shoe and the defects indicate the problems to be noticed upon design of synthetic leathers.
• the leather has a unique beauty attributable to its grain surface. Commonly the expression leather-like has been used, and leather-made ornaments match Well both Japanese clothes and European clothes.
• the leather possesses great, balanced mechanical strength.
• the tensile strength and tear strength of the leather are greater than those of the other materials which resembles in other properties to the leather and would be employed in the same uses as that of the leather, and there is not found any differential in the strength between the longitudinal and lateral directions as found in the other materials.
• the leather exhibits a unique tension-elongation curve, to say, the leather has a greater modulus than the other materials employed in the same uses, and the differential in tensile strength and in elongation between dry state and wet state is not so great as in the other materials in spite of great differentials in the other properties.
• the leather is pliable, readily gets to fit and has a small specific gravity. These indicate that the leather has a high flexibility in the shape and a high adaptability in the working.
• the leather has proper moisture-absorbing property and moistureand air-permeabilities.
• the development of the function combined these properties is an essential property for raw material of products used daily, and in a highly humid environment as in Japan.
• the leather has temperature retaining and heat insulating properties. It is evident from its structure that in addition to the above described properties are added, and this makes it excellent heat insulating materials to be used in the winter season.
• the leather is capable of being formed into a product with a desired curved surface. This indicates the leather having an excellent workability, and it is said that the harmony in resiliency and creeping property is the characteristic of the component of the leather.
• the leather is dyeable with case. This indicates that the composition in grain surface, is compact and uniform and that the leather may be suitably used as material for personal ornaments and wears.
• the leather is different in properties according to the race of animal and the area living the animal, and even in the same race of animal the properties of the leather are different depending upon the sex, age, feed, season and other factors, and in one piece of leather the properties differ according to portions.
• the leather is different in size and thickness from piece to piece, so that it has been handled manually and it is of difficulty to handle the leather by machines.
• the leather is, as mentioned above, restricted in size and the parts having the same property are small, so that it is of difficulty to cut a patch with a desired shape from a piece of leather, and this influences highly upon the cost.
• the leather is not inexpensive and, in addition, the leather is not manufactured as an industrial material for the main object but it is byproduct of the meat, so that an amount of the leather supplied is influenced by the weather and the demand condition of meats and the price is varied.
• An object of the present invention is to provide a synthetic leather which retains the advantages of the natural leather and is improved fully in the defects of the latter and the method of preparing such synthetic leather.
• the synthetic leather of the present invention may be obtained by forming a web or fibrous mat with a mix-spun fiber comprising at least two high molecular weight materials, impregnating the web with a solution of one or more high molecular weight materials, coagulating the impregnating substance in a wet or dry process and, thereafter extracting and removing at least one high molecular weight material which constitutes the mix-spun fiber by treating said web in a solvent for at least one of the high molecular weight materials constituting the fiber.
• the mix-spun fiber may be obtained by a wet, dry or melt spinning of a mixture of two or more high molecular weight materials, although the melt spinning process is preferable.
• the filament is stretched after spun.
• high molecular weight materials are polyolefins, such as polyethylene and polypropylene; atacticand isotactic polystyrenes, alkyl or halogen substituted polystyrenes; polyamides, such as 6-nylon and 66-nylon; polyesters, such as polyethylene terephthalate; polymethacrylates such as polymethylmethacrylate; polyvinyl esters such as polyvinyl acetate and polyvinyl butylate; polyvinyl alcohol and its derivatives; polyvinyl halides such as polyvinyl chlorides; polyacrylonitrile; polyvinylidene halides such as polyvinylidene chloride; cocondensates or copolymers comprising various low molecular weight condensated or polymerized materials and graft high molecular weight materials as obtained by graft polymerization of various polymerizable low molecular weight substances with the various homopolymers or cocondensates or copolymers thereof
• the mix ratio of these mix-spun fiber is 20% or more of one high molecular Weight material with respect to the other material.
• the high molecular weight material to be removed and extracted in the mix-spun fiber preferably is swollen with or dissolved in the solvent in the solution of the high molecular weight mate rial to be impregnated in the mat and, in this case, there is obtainable a satisfactorily compact synthetic leather due to a press effect during the coagulating step.
• a web or fibrous :mat in a wet or dry process from the resulting mix-spun fiber is too coarse and when desiring to obtain a final product with a high strength, the web or fibrous mat may be tightened in a suitable manner.
• This process preferably is carried out as follows: The mix-spun fiber is cut into a staple, which is formed into a random web by means of a random webber. The random web is then tightened and three dimensionalized by means of a needle punch. When the tightening is insufficient, the web is further tightened by compression. It is preferable to heat the web during the compression. The tightening also may be effected by application of shrink to the fibers. The demand to obtain a final product with a high strength may be attained by stretching the sheet material without allowing any shrinkage.
• 'Ilhe present invention has a distinctive feature in the process for manufacture of such three-dirnensionalized non-Woven fabric.
• the mat In the manufacturer of a good synthetic leather from a three-dimensionalized non-woven fabric, it is a fundamental condition that the mat is pliant and supple.
• a fiber with a fine denier less than 1 denier, preferably less than 0.5 denier It is, however, difficult to form a random web by passing such fine fiber through a card sliver and to form a three-dimensionalized non-woven fabric therefrom by means of a needle punch because of a poor spinnability of such fine fibers.
• a well-spinnable fiber of from 1.5 to 3.0 denier to form a mat.
• a thick fiber with a denier as large as from 1.5 to 3.0 denier is far superior in spinnability to a fine fiber with a denier as small as 0.5 denier or less.
• a mat which has been made from a large fiber with a denier of as large as from 1.5 to 3.0 denier is in general not pliant, but at least one high molecular Weight material within the fiber is extracted and removed in a subsequent extraction process, whereby it is possible to obtain a mat having the same pliability as that of mat made from a fine fiber with a denier of about 0.5 denier.
• a fibrous mat is made from a mix-spun fiber composed of two components, one being soluble and another being insoluable in the subsequent step.
• This brings about an additional advantage.
• a fiber formed of a 6-nylon alone has a poor spinnability due to its low Youngs modulus and to its unsuitable dryto-wet ratio in Youngs modulus.
• 6- nylon fiber having a fiber denier assmall as 0.5 denier is very ditficult in the spinnability.
• a mixspun fiber formed of a mixture of a 6-nylon and a polystyrene has an improved Youngs modulus and wet-todry ratio in Youngs modulus as shown in Table 1.
• the web or sheet material so formed in the above steps is impregnated with a solution of a high molecular weight material.
• the high molecular weight material includes: (1) one or more high molecular weight material having rubber-like elasticity and (2) mixtures of one or more high molecular weight material having rubber-like elasticity with one or more high molecular weight materials having no rubber-like elasticity.
• the solution need not be a true solution, but may be an emulsion as far as it is possible to impregnate the web therewith. To the solution there may be added salts, dyes, pigments, fillers, various surface active agents and other additives.
• any of such ones which are insoluble in the solvent to be used in extraction of an eX- tractable high molecular Weight material in the mix-spun fiber are used any of such ones which are insoluble in the solvent to be used in extraction of an eX- tractable high molecular Weight material in the mix-spun fiber.
• examples are polyurethanse-type elastic high moleoular weight materials, acrylates, syn-thetic rubbers, chlorinated polyethylene and polyolefin derivatives, internally plasticized high molecular Weight materials and other elastic high molecular weight materials having a rubbery elasticity.
• high molecular weight material having no rubbery elasticity use may be made of various polymerized or condensated high molecular weight materials such as polyvinyl chloride, polyacrylonitrile, polystyrene, polyvinyl alcohol or acetalized product thereof, polyvinyl acetate, polyamides, modified polyamides, polypropylene, polyethylene, polyurethanes, polyureas, polyesters, polycarbonates or cocondensated or copolymerized materials thereof, or graft polymerized high molecular weight materials.
• polyvinyl chloride polyacrylonitrile, polystyrene, polyvinyl alcohol or acetalized product thereof
• polyvinyl acetate polyamides, modified polyamides, polypropylene, polyethylene, polyurethanes, polyureas, polyesters, polycarbonates or cocondensated or copolymerized materials thereof, or graft polymerized high molecular weight materials.
• the impregnated material After impregnation of the web with the high molecular weight material, the impregnated material is coagulated in a wet and/0r dry process. It is preferred to press or hot press the impregnated sheet material either before, during or after the coagulating process.
• the sheet material is then treated with a solvent to extract therefrom at least one of the high molecular weight materials which are components of the mix-spun fiber forming the sheet material. It is preferable to remove by extraction, before, during or after the extracting step, a part of the impregnated high molecular weight materials capable of extracting and removing and a ortion of a coating film which has been applied to a grain surface as hereafter described.
• the solvent to be used in the 'invention for extraction of at least one of the high molecular weight materials which constitute the mix-spun fiber should be solvent for at least one high molecular weight material (soluble component) but non-solvent for the remainder (insoluble components) of the high molecular weight materials forming the mix-spun fiber.
• the solvent suitably used in the extraction varies with the nature of the mixspun fiber as a raw material of the artificial leather of the invention, there may be used water, organic solvents, such as aromatic compounds, cyclic ethers, aliphatic hydrocarbons, ketones, cyclic ketones and the like; various salt solutions, such as methanol solutions of calcium chloride, titanium tetrachloride, lithium chloride and the like; and mixtures thereof.
• the synthetic leather of the invention thus obtained is composed of a layer of fiber which retains a complete fibrous structure as in the natural leather, and the synthetic leather of the present invention is similar in external appearance, texture, touch and other characteristics to the natural leather.
• the synthetic leather of the present invention accomplishes to the problems for synthetic leathers as fully described at the head of this specification.
• the fiber, which constitutes the leather has numbers of micro-pores and a grain surface as a result of extraction of at least one of the high molecular weight materials forming the fiber. This makes the synthetic leather of the invention very pliant and similar in structure to the natural leather.
• the fiber iself is made more pliant by the micro-pores therein formed and that the soluble component of the fiber exposed to the surface of the fiber is extracted to form a number of spaces between the impregnated materials and the fiber and 'whereby the fiber separates the high molecular weight materials having rubbery elasticity to become movable each other.
• the micro-pores and spaces result in essential improvements in air permeability, moisture permeability and air-retaining property and in the natural leather-like texture.
• a large number of micro-pores of the shaped article of the invention is not only based on spaces formed between the fibers each other composed of the shaped article, but also on hollows of the fiber itself composed the shaped article. Porosity of the fiber depends upon the proportions of two or more high molecular weight materials in the initial fiber to be used in making the shaped article. This will be illustrated by the following example.
• Chips prepared by blending a 6-nylon and a polystyrene at various mix ratio are extruded through a nozzle having 100 holes each of 0.2 mm. diameter to form fibers having different mix ratios, which are stretched 300% at 175 C. and then 50% at 200 C. (the total stretch ratio of 500%).
• the stretched fibers are extracted with benzene at 65 C. to remove therefrom polystyrene.
• the properties of the porous fibers are as follows:
• the fiber is fibrilized at the buffed part to a very fine denier, and this imparts to the synthetic leather an excellent leather-like texture.
• a chip consisting of a blend of 40 parts of a 6-nylon and 60 parts of a polystyrene is extruded by means of a screw-type cxtruder through a spinneret with 300 holes each of 0.2 mm. in diameter at spinning temperature of 300 C. into a draughting zone cooled to a temperature of 120 C. by air blast and is Wound up at a rate of 600 m./min.
• the mixed fiber thus spun is formed crimps of 24/in. and out to a length of 3 cm. and then formed into a three-dimensionalized web of 330 g./m. by means of a random webber and a needle puncher.
• the web is lightly compressed by means of hot rollers at 100 C.
• the so pressed web is immersed in a 13% solution in dimethylformamide of a polyurethane type elastic high molecular weight material obtained by reaction of polyester of adipic acid and ethylene glycol and diphenylmethane diisocyanate and glycol and coagulated in Water and then dried, and treated with toluene to extract the remaining solvent and polystyrene in the fiber.
• the web thus treated is improved remarkably in pliability and texture as compared with the web prior to the extraction and has fundamental characteristics as leathers, such as air-retaining property, air-permeability, moisture-permeability and others.
• the porosity indicates value obtained by dividing the deniers of the fiber after extraction of polystyrene by the deniers of the fiber composed of insoluble components only having the same sectional area as that of the former.
• the fiber which constitutes the shaped product of the present invention, has a porosity of up to about 70%.
• the remarkable pliability is the charac teristic of the synthetic leather of the invention.
• a fiber having a fine denier because a mat which has been formed of a fiber having a large fineness results in a rigid synthetic leather.
• the fine fiber however, has a defect of having a poor spinnability.
• the synthetic leather of the invention thus obtained has such external appearance, texture and other properties similar to those of the natural leather.
• the synthetic leather of the invention is composed of a layer of fibers which retains completely the same fibrous structure as that of the natural leather.
• a grain surface which is a characteristic of the natural leather, may be formed on a surface of the synthetic leather by applying thereto a film or the like, and in the invention this may also be performed by the following procedure.
• a suitable amount of a solution of a high molecular weight material is applied to a surface of the synthetic leather prepared in the manner as mentioned hereinbefore and is coagulated in a -wet or dry process.
• the coagulation preferably is conducted in a wet process, or jointly in a dry process partly and in a Wet process mainly.
• the high molecular weight material suitably used as coating material includes: (1) one or more high molecular weight materials having rubbery elasticity, and (2) mixtures of one or more high molecular weight materials having rubbery elasticity and one or more high molecular weight materials having no rubbery elasticity.
• the term high molecular weight material having rubbery elasticity and high molecular weight material having no rubbery elasticity have the same meanings as mentioned hereinbefore and, as also mentioned above, the solution of high molecular weight material means not only true solution but also emulsion.
• salts may be added to the solution there may be added salts, dyes, pigments, fillers, various surface active agents and other additives.
• a proper amount of a high molecular weight material is applied to the surface of the web or the sheet material in any stage of preparation of the synthetic leather and is thereafter coagulated in a dry or wet process; specified examples of the modified processes are as follows:
• a web of mix-spun fiber is impregnated with a solution of high molecular weight material and the impregnating material is partly or entirely, coagulated in dry and/ or wet processes, thereafter a solution of high molecular weight material is applied thereto by coating or spraying to form a grain surface and is then coagulated in dry and/or wet processes. Then the web is soaked in a solvent for at least one high molecular weight material in the mix-spun fiber to extract therefrom the said high molecular weight material, and washed and dried.
• a web of mix-spun fiber is impregnated with a solution of high molecular weight material and, thereafter, a solution of high molecular weight material is applied thereto by coating or spraying to form a grain surface. Then the both high molecular weight materials are coagulated in dry and/or wet processes. At least one high molecular weight material in the mix-spun fiber is extracted therefrom and the so treated web is washed and dried.
• a web of mix-spun fiber is impregnated with a solution of high molecular weight material and the high molecular weight material is coagulated in a Wet process.
• the Web is then washed and dried and, thereafter, a solution 01f high molecular weight material is applied thereto by coating or spraying to form a grain surface.
• At least one high molecular weight material in the mix-spun fiber is extracted therefrom and the so treated web is washed and dried.
• the resulting synthetic leather Even if a solution of high molecular weight material is applied relatively thick on formation of the grain surface by coating or spraying of the high molecular weight material, the resulting synthetic leather has satisfactory airand moisture-permeabilities, such properties being important characteristics of leathers, because portion of the applied high molecular weight material is removed by extraction in a subsequent step of the process, and the removal of portion of the high molecular weight material results in formation of a moderate indention which makes the resulting synthetic leather very similar in external appearance to the natural leather.
• the grain surface may also be obtained by forming a Web with a mix-spun fiber made from a blend of high molecular weight material having rubbery elasticity and a high molecular weight material having no rubbery elasticity, laminating the said Web on a synthetic leather of the invention as already mentioned above and, thereafter, completely or almost completely dissolving said high molecular weight materials in said Web and, thereby, bonding said web to said synthetic leather.
• the synthetic leather of the invention there may be added, if desired, a step of partially dissolving the unextractable high molecular weight materials in the mix-spun fiber to adhere the fibers to other fibers.
• the mix-spun fiber of a raw material for the synthetic leather of the invention may be used in admixture with a proportion of various fibers comprising monopolymer or natural fibers.
• a woven fabric composed of a synthetic fiber consisting of monopolymer, or natural fiber may be used as a core layer or substratum.
• the two steps of coagulation and of extraction may be conducted simultaneously.
• EXAMPLE 1 A stretched and crimped nylon-polystyrene 40:60 mixspun filament of 2 denier was cut into a staple fiber of 5.0 cm. length and the staple fiber was formed by random webbing and subsequent needle punching into a nonwoven mat of a weight of 220 g./m.
• the non-woven mat thus formed was immersed in an impregnating solution prepared by adding 0.4% of cellulose octadecylurethane as softener to a 8% solution in dimethylformamide of a polyurethane elastomer obtained by reaction of a polyethylene propylene adipate of a molecular weight of 1,500 (mole ratio of ethylene glycol units to propylene glycol units of 07:03), p,p-diphenylmethane diisocyamate and ethylene glycol in the mole ratio of 1:2.5:1.5, and then squeezed by means of doctor blades at each side of the mat to adjust the amount of the solution taken up by the mat to about eight times the weight of the mat.
• an impregnating solution prepared by adding 0.4% of cellulose octadecylurethane as softener to a 8% solution in dimethylformamide of a polyurethane elastomer obtained by reaction of a polyethylene propylene adip
• the mat was then immersed in a 30% aqueous solution of dimethylformamide at 30 C. for a period of 15 minutes and squeezed while coagulating the impregnating and coated materials, and then Washed with water for a short period of time, after which was passed through hot press rollers and then extracted and removed at least of polystyrene in the nylon-polystyrene mix-spun fiber by toluene at 70 C.
• the sheet material thus obtained was extremely pliant due to poor adhesion between nylon fibers and poly urethane elastomer and presence of random micro-pores which had been formed in the nylon fibers as a result of extraction of polystyrene, and possessed a smooth texture.
• the grain surface of the sheet material was extremely tough due to presence of fibers and was fine-grained and pliant, and possessed a texture similar to that of natural leather, especially those for wear uses.
• the properties of the sheet material were similar to those of sheep skin as shown in the following table.
• the mat was then immersed in a 30% aqueous solution of dimethylformamide for 20 minutes to coagulate and, thereafter, extracted polystyrene in the fiber by toluene at 6570 C.
• the sheet material thus obtained was of an apparent specific gravity of 0.5-0.6 and possessed a compact texture.
• the sheet material possessed a moderate pliability due to poor adhesion between resin and fibers and presence in fibers of random micro-pores resulting from the extraction, and exhibited a texture similar to that of the natural leather for shoe upper use.
• the properties of the sheet material were as shown in the following table.
• the web was impregnated with a 6% solution obtained by dissolving a mixture of 60 parts of a polyurethane-type high molecular weight material as in Example 1 and 40 parts of a polystyrene in dimethylformamide and, thereafter, a 5% solution obtained by dissolving a mixture of 40 parts of a polyurethane type high molecular weight material, parts of a polyvinyl chloride and 30 parts of polystyrene in dimethylformamide was again sprayed to grain surface of the impregnated web.
• the web was then coagulated by water and treated in toluene at 80 C. to completely extract polystyrene in the resulting shaped article which was then washed with methanol and dried.
• the sheet materials as shown in the above examples may be dyed, or applied a smooth surface by known method such as dyeing, spraying, coating or laminating a solution or emulsion of a high molecular we ht material or embossing or otherwise finishing.
• EXAMPLE 3 A blend of 50 parts of a 6-nylon and 50 parts of a polystyrene was melt spun by means of extruder into filaments and stretched by 6 times to obtain a mix-spun fiber of 1.5 denier, which was wound and crimped to 18/in., cut into 50 mm. length and, thereafter, passed through a random webber and a needle loom to form a web with a three-dimensional network structure.
• the web was impregnated with a 6% solution in tetrahydrofuran of a polyurethane prepared by reacting a polyester derived from adipic acid and ethylene glycol with diphenylmethane dissocyanate to form a prepolymer and subsequently reacting the prepolymer with a diol, and was then immersed in water to coagulate the polyurethane. After dried, the shaped article thus formed was immersed in toluene at 90 C. for one hour to extract polystyrene, then washed with methanol and dried.
• the finished shaped article of the invention was a pliable leather-like product with a high elasticity.
• EXAMPLE 4 Single surface of the pliable shaped article, as obtained in Example 3, was burned and the shaped article was then hot pressed. Then a 7% solution of a polyurethane type high molecular weight material as used in Example 1 in dimethylformamide was applied by spraying to the burnt surface of the shaped article to form a very thin coating film. Thus, there was obtained a synthetic leather just like natural leather.
• the synthetic leather of the invention thus obtained was similar in external appearance, texture and other properties to those of natural leather.
• EXAMPLE 7 A mix-spun filament (1.5 denier) formed of a blend of parts of a polystyrene and 50 parts of a polyethylene terephthalate was formed crimps of 20/in. and cut into 3 cm. length. The staple fiber thus obtained was formed, in the same manner as in Example 6, into a three-dimensionalized random web with a weight of 250 g./m.
• the web was impregnated with a 6% solution in dimethylformamide-acetone (121) of a polyurethane type high molecular weight material prepared by reacting a polyethylene adipate with diphenylmethane diisocyanate to form a prepolymer and reacting the prepolymer with a diol and, thereafter, the web was squeezed by means of rubber rollers so as to adjust the amount of the solution taken up by the web to 600% by weight of the web.
• the solution was then applied again to the surface of the web and the web was, after stood still for a short period of time, coagulated by 30% aqueous dimethylformamide solution, while squeezing.
• the shaped article thus formed was immersed in toluene at 80 C. for minutes to effect complete extraction of polystyrene in the mix-spun 13 fiber, and then washed and dried.
• the artificial leather thus obtained possessed the same external appearance, texture and other properties as that of natural leathers.
• EXAMPLE 8 A mix-spun filament composed of a blend of 40 parts of a 6-nylon and 60 parts of a polyvinyl alcohol was stretched by 6 times at 200 C. to obtain a fiber of 1.5 denier. The filament was formed crimps of 18/in. and cut into 50 mm. length and, thereafter, passed through a random webber and a needle loom to form a web with a three-dimensional net-work structure.
• the web was impregnated with a 6% solution in dirnethylformarnide of a polyurethane prepared by reacting polyester obtained from ethylene glycol and adipic acid with a diphenylmethane diisocyanate and a diol and then immersed in water so as to elfect coagulation of polyurethane and at the same time extraction of polyvinyl alcohol contained in the mix-spun fiber and was, thereafter, washed again with water and dried.
• the shaped article of the invention thus obtained was an extremely pliant leather-like product with a high elasticity.
• EXAMPLE 9 A mix-spun filament of 2 denier obtained by melt spinning a blend of 45 parts of a polyester derived from terephthalic acid and ethylene glycol and 55 parts of a polystyrene by an extruder and hot drawing by 5 times.
• the fiber was formed into a web with a three-dimensional network structure in a manner as in Example 8 and the web was impregnated with a 6% solution of a blend of 60 parts of a polyurethane type high molecular weight material as in Example 1 and 40 parts of a polystyrene in dimethylformamide. Then a 5% solution of a blend of 40 parts of a polyurethane type high molecular weight material, 30 parts of a polyvinyl chloride and 30 parts of polystyrene in dimethylformamide was sprayed to the grain surface and, thereafter, the web was treated in cyclohexane at 50 C. to remove completely polystyrene and coagulate polyurethane in the shaped article and then was washed with methanol and dried.
• a method for the manufacture of pliant, supple, airand moisture-permeable sheet material comprising:
• said fibrous substrate being comprised of mix-spun fibers shaped from polymers comprising at least two high molecular weight materials'selected from the group consisting of polyamide, linear condensation polyester, polymethacrylate, polyvinyl ester, polyvinyl alcohol, derivatives of polyvinyl alcohol, polyolefin, atactic and isotactic polystyrene, alkyl-substituted polystyrene, halogen-substituted polystyrene, polvinyl halide, polyacrylonitrile, and polyvinylidene halide;
• the high molecular weight material (i) is at least one member selected from the group consisting of elastomeric segmented polyurethane, polyacrylate, synthetic rubber, chlorinated polyolefin and chlorinated polyethylene, and further wherein the high molecular weight material (ii) is a mixture of the above high molecular weight material (i) with at least one member selected from the group consisting of polyvinyl chloride, polyacrylonitrile, polystyrene, polyvinyl alcohol, acetalized polyvinyl alcohol, polyvinyl acetate, polyamide, polypropylene, polyethylene, nonelastomeric polyurethane, polyurea, linear condensation polyester and polycarbonate.
• step (c) is selected from the group consisting of: water, an aromatic hydrocarbon, a cyclic ether, an aliphatic hydrocarbon, an aliphatic ketone, a cyclic ketone, and a methanol solution of calcium chloride, titanium tetrachloride and lithium chloride, and mixtures thereof.
• step;(a) is a true solution.
• step (a) is an emulsion.
• the fibrous substrate is formed from mix-spun fibers obtained by mixed spinning of at least two polymers.
• the high molecular weight material (i) is at least one member selected froh'i the group consisting of elastomeric segmented polyurethane, polyacrylate, synthetic rubber, chlorinated polyolefin and chlorinated polyethylene, and further wherein the high molecular weight material (ii) is a mixture of the above high molecular weight material (i) with at least one member selected from the group consisting of polyvinyl chloride, polyacrylonitrile, polystyrene, polyvinyl alcohol, acetalized polyvinyl alcohol, polyvinyl acetate, polyamide, polypropylene, polyethylene, nonelastomeric polyurethane, polyurea, linear condensation polyester and polycarbonate.
• mixspun fibers are composed of poly-(e-caprolactam) and polystyrene.
• step (a) is with a solution of an elastomeric segmented polyurethane in dimethylformamide.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dispersion Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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Cited By (11)

Citations (2)

• 0
  • BE BE655812D patent/BE655812A/xx unknown
  • NL NL131976D patent/NL131976C/xx active
• 1964
  • 1964-11-05 LU LU47292A patent/LU47292A1/xx unknown
  • 1964-11-09 US US409997A patent/US3424604A/en not_active Expired - Lifetime
  • 1964-11-13 FI FI2389/64A patent/FI42819B/fi active
  • 1964-11-13 CH CH1467164A patent/CH436211A/de unknown
  • 1964-11-13 SE SE13685/64A patent/SE316141B/xx unknown
  • 1964-11-14 ES ES0306049A patent/ES306049A1/es not_active Expired
  • 1964-11-14 DK DK563064AA patent/DK115986B/da unknown
  • 1964-11-16 DE DE19641469550 patent/DE1469550A1/de active Pending
  • 1964-11-16 GB GB46505/64A patent/GB1094064A/en not_active Expired
  • 1964-11-16 NL NL6413333A patent/NL6413333A/xx unknown

Patent Citations (2)

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