Classifications

• • 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
  • D04H1/68—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 the bonding agent being applied in the form of foam
• • 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
  • D04H1/587—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 characterised by the bonding agents used
• • 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
• • 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
  • D06N3/04—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • 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
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/23907—Pile or nap type surface or component
  • Y10T428/2395—Nap type surface
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249978—Voids specified as micro

Definitions

• This invention is directed to a tenacious and moisture permeable leatherlike sheet material having breatheability and water absorbability and which is comparable to natural leathers in durability and wearing comfort. It comprises: a base fabric having a large content of its void spaces; a microporous and aqueous insoluble polyvinyl acetal resin, adhering to and entirely covering the structural fibers of said fabric, in the form of a unitary three dimensional network; and a layer of a different resin covering said polyvinyl acetal resin.
• the sheet material may have a grain side layer on at least one surface side thereof.
• a process for manufacturing such a sheet material comprises steps of: impregnating a base fabric with an aqueous solution of polyvinyl acetal; heating the impregnated fabric at 50"l30C.; further impregnating said fabric with liquid comprising different resin; and curing.
• the resultant article is particularly useful for inner parts of shoe, such as insole, sole pad, inner lining and the like.
• This invention relates to a leatherlike material and a process for making the same and, more pmicularly, to such a leatherlike sheet material which has a combination of properties including an excellent air and moisture permeability and a high strength.
• the moistening or humidification of the inside of a shoe is not only out uncomfortable but also undesirable from the sanitary point of view, for in most cases, shoes are worn continuously for a long time throughout all seasons.
• the previously known manmade leathers have had such a drawback that when they are used as chair coverings, wall linings, motor-car panellings, upholstery materials and the like, those articles are apt to get moist or to have dew-drops condensed on their surface especially under moist atmospheric conditions, for instance, in a rainy day or in the rainy season, or owing to some variations in temperature.
• Another object is the provision of a process of making flexible and tenacious moisture permeable sheet materials having a microporous polymeric component in adherence with fibers in their substrate.
• Still another object is the provision of an economical process of making such sheet materials which are comparable with natural leathers in durability and comfort characteristics.
• a leatherlike material comprising a base fabric and a microporous and aqueous insoluble resin consisting essentially of acetalized product of polyvinyl alcohol (hereinafter referred to as polyvinyl acetal”) adhering to and entirely covering the structural fibers of the said base fabric, the said resin forming a unitary three dimensional network containing a number of pores therein, the surface of the said resin being covered continuously by a layer comprising at least one resin different from the aforementioned resin.
• polyvinyl acetal polyvinyl alcohol
• such a leatherlike material comprises a base fabric having a large content of void spaces and a microporous and aqueous insoluble polyvinyl acetal resin, specifically polyvinyl formal resin, adhering to and entirely covering the structural fibers of the said base fabric, which resin extending from the surface of the fibers towards void spaces formed among the fibers, interconnecting adjacent fibers and forming a unitary three dimensional network containing a number of pores therein, the said network uniformly existing in and extending over the fabric, the surface of the said resin being covered continuously by a layer comprising at least one resin different from the aforementioned polyvinyl acetal resin.
• Another embodiment of the present invention is a leatherlike material comprising a substrate consisting of the above obtained leatherlike material, and a grain side layer formed on the surface of the substrate, which grain side layer comprising at least one resin selected from the class consisting of synthetic resins and natural resins.
• the invention further comprises a process of making a leatherlike material which comprises first step of impregnating a base fabric with an aqueous solution containing water soluble polyvinyl acetal, second step of heating the impregnated fabric at 50-l30 C. to promote acetalization of said polyvinyl acetal, whereby resulting microporous and aqueous insoluble polyvinyl acetal resin adhering to and entirely covering the structural fibers of the said fabric, third step of further impregnating the resultant fabric with liquid containing emulsion or solution of at least one resin different from polyvinyl acetal selected from the class consisting of synthetic resins and natural resins and fourth step of curing the thus resin impregnated fabric.
• FIG. I is a magnified schematic cross-sectional view, somewhat diagrammatic and fragmentary in character, illustrating conditions of fibers when the base fabric is impregnated with a treating solution.
• FIG. 2 is also a magnified schematic cross-sectional view, illustrating the structure of leatherlike material of the present invention, wherein the base fabric has been bound and entirely covered with the microporous, water-insoluble polyvinyl formal resin and the other polymer consolidated after the course of fourth step of the invention.
• FIG. 3 is a diagrammatic side elevational view of an apparatus suitable for carrying out the process of the present invention.
• FIGS. 4 and 5 are diagrams showing the relation between time elapsed from impregnation of water and water content with respect to insoles manufactured from the leatherlike material of the present invention and those in the market.
• FIG. 6 is a perspective view, with a part broken away, of an ordinary shoe for gentlemen.
• FIG. 7 is a vertical cross-sectional view of the shoe shown in FIG. 6.
• structural fibers of the base fabric As structural fibers of the base fabric, effectively applicable are natural fibers such as cotton, silk, wool and the like, artificial fibers such as cellulose acetate fibers, viscose rayons, cupra and the like, and synthetic fibers consisting of such a polymer as polyacrylonitrile, polyamide, polyester, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyolefin and the like.
• polyamide fibers such as nylon-6, nylon-66 and the like, polyvinyl alcohol fiber what is called Vinylon or the like and viscose rayon are suitable among the others.
• the structure of the base fabric has a large content of void spaces and from this point of view, nonwoven fabrics such as web and batt, pile fabrics with projecting filaments, napped fabrics, terry, plush and the like are advantageously applicable.
• the aforementioned base fabric which has been relevantly prepared and selected is impregnated with an aqueous solution containing water soluble polyvinyl acetal as its principal ingredient.
• the treating solution i.e., and above-mentioned aqueous solution can be prepared in the following manner.
• An aqueous solution of polyvinyl alcohol is admixed with aldehydes such as formaldehyde, acetaldehyde, butylaldehyde, glyoxal, benzaldehyde and the like, and acids such as hydrochloric acid, sulfuric acid, hydrobromic acid, phosphoric acid, trichloroacetic acid, organic sulfonic acids and the like, to acetalize the polyvinyl alcohol.
• aldehydes such as formaldehyde, acetaldehyde, butylaldehyde, glyoxal, benzaldehyde and the like
• acids such as hydrochloric acid, sulfuric acid, hydrobromic acid, phosphoric acid, trichloroacetic acid, organic sulfonic acids and the like
• An aqueous solution of the thus obtained water-soluble polyvinyl acetal can be used as the above-mentioned treating solution, to which a catalyst for acetalization comprising aldehydes and the above-mentioned acids or their salts, a pore forming agent such as starch, dextrine and the like, or a coloring agent is incorporated, if required.
• the treating solution may be applied to the base fabric by any conventional method, such as pad-squeezing, doctor coating, roll coating, brush coating and spraying.
• the application or impregnation of the solution may be effected from one side or both sides of the fabric.
• the amount of the solution adhered to the fabric is preferably 10-20 percent by weight of its solid ingredients based on the weight of fabric, and more preferably -100 percent by weight, although it differs according to the kind of fabric or its outlets;
• the first step wherein the base fabric is impregnated with the treating solution is successively followed by the second step in which the fabric is heated to promote acetalization of the polyvinyl acetal which has been applied to the fabric in the preceding step, up to a degree of acetalization of 30-85 percent by mole, preferably 50-75 percent, whereby C., more referably of 70polyvinyl acetal is consolidated to form a microporous and water-insoluble polyvinyl acetal resin of a unitary three dimensional network in the base fabric.
• the heating is conducted preferably at a temperature of 50-l30 C., more preferably of 70-l00 C.
• a manner of heating either dry heating or steam heating may be adoptable and in general, the latter is more preferable.
• a heating period can be determined appropriately according to the temperature as well as the heating manner.
• the fabric thus heat treated in the second step A leatherlike mentioned above may be neutralized, washed to extract excess aldehydes, catalysts for acetalization, other water soluble substances poly(vinyl nonreacted substances therefrom, squeezed and dried, if required.
• structural fibers 1 are impregnated with treating solution 2. if such a fabric is subjected to a heat treatment, then as is shown in FIG. 2, insolubilized and consolidated acetalized product 3 having a microporous structure is formed therein, adhering to and entirely covering the structural fibers l as a unitary three dimensional network.
• the acetalized resinous product 3 extends from the surface of the structural fibers 1 towards void spaces formed among structural fibers, interconnecting adjacent structural fibers and occupies a part of said void spaces forming pores or cavities 4.
• the acetalized resinous product 3 now formed is water insoluble, comparatively hydrophilic and extremely microporous and which composes a unitary three dimensional network extending on and along the structural fibers. Accordingly, the product resulting from the aforementioned second step exhibits excellent water and moisture absorbability as well as moisture exhalability and furthermore displays superior water retentiveness and air permeability due to its numerous pores or cavities 4.
• the product manufactured by the foregoing two steps may have its top surface buffed or abraded, or may be sliced or pressed so as to be as thick as is desired, by an appropriate method prior to being subjected to the third step.
• resins to be applicable for the preparation of the treating liquid used in the third step mention may be made of: addition polymers such as acrylic and vinylic polymers; condensation polymers such as polyamides, polyesters, polyurethanes and the like; synthetic rubbers such as styrene/butadiene rubber, nitrile/butadiene rubber and the like; and natural rubber.
• condensation resins for instances prepolymers of such condensation resins as a ureaformaldehyde resin, melamine-formaldehyde resin, phenolsformaldehyde resin and the like are also preferably applicable for the preparation of the treating liquid.
• Latex, and solution in organic solvent, of polyurethanes, polyacrylonitrile, polyacrylic acid esters, polyamides or polyvinyl chloride, and aqueous solution of precondensate of melamine-formaldehyde are especially preferable among the others.
• plasticizers such as butyl lauryl phthalate, butyl phthalyl butyl glycolate, dibutyl phthalate, diethyl phthalate, di-2-ethyl hexyl phthalate, dimethyl phthalate, di-n-octyl phthalate, tricresyl phosphate, ethylene glycol, glycerine and the like; catalysts for condensation reaction such as hydrochloric acid salts of organic amine, magnesium chloride, zinc nitrate, ammonium chloride and primary ammonium phosphate; coloring agents; softening agents; and hardening agents.
• plasticizers such as butyl lauryl phthalate, butyl phthalyl butyl glycolate, dibutyl phthalate, diethyl phthalate, di-2-ethyl hexyl phthalate, dimethyl phthalate, di-n-octyl phthalate, tricresyl phosphate, ethylene glyco
• the sheet material which has been treated in the third step isthen subjected to the fourth step, wherein said sheet material is heated preferably at 50-l80 C., although the suitable heating temperature varies depending upon characteristics of the resin impregnated to the material in the foregoing step.
• the applied resin covers the surface of the aforementioned polyvinyl acetal resin which uniformly exists in and extends over the base fabric, whereby interconnection or conjunction of structural fibers is secured, resulting in a tenacious and tough leatherlike material, which retains appropriate air and moisture permeability.
• An amount of the resin to be fixed onto the sheet material in the fourth step is preferably 5-l00 percent by weight based on the weight of the base fabric and more preferably 10-50 percent by weight, although the above stated preferable range may somewhat vary according as the kinds of resin and intended outlets of the product.
• the sheet material may be pressed on a cylinder heating apparatus or compressed by and between two hot plates under a pressure of 3-20 kg./cm. simultaneously with heating.
• base fabric 5 is passed through a first saturator 6, impregnated with treating solution 7 and squeezed by squeeze rolls 8 to control the pickup.
• the fabric is subjected to a heat treatment, then squeezed again by squeeze rolls iii to remove an excess treating solution, fed into washer l l consisting of first washing bath l2 and second washing bath 13, wherein the fabric is successively washed, and squeezed by squeeze rolls 14.
• a second saturator 15 to impregnate with treating liquid 16
• squeezed by squeeze rolls 17 to regulate the pickup and wound up on a roll by a batch-up device 18.
• processed and batched-up sheet material is then subjected to the fourth step of heating with or without pressing according as its contemplated outlets.
• conventional methods for manufacturing manmade leathers their process and steps have been so complicated that they have been difiicult to carry out continuously, while according to the process of the present invention, a continuous process can be readily realized utilizing conventional equipments and machineries.
• the fifth step of the process of the invention will ex plained hereafter.
• resin is applied onto the surface of the sheet material which has been prepared by and through the foregoing four steps and which is used as a substrate in the instant step, to fonn a grain side layer on the top side thereof.
• Resins to be employable to form the grain side layer are: synthetic polymers such as polyurethanes, polyamides and vinyl polymers; synthetic rubbers such as styrene/butadiene rubber, nitril/butadiene rubber and the like; artificial resins such as cellulose acetate, cellulose nitrate and the like; and natural resins such as natural rubber.
• a treating liquid in the form of emulsion, aqueous solution or solution in organic solvent, of the above-mentioned resin is prepared, using the resin either solely or in combination of more than one, and which treating liquid is applied and coagulated on the top side of the substrate which has been obtained by the aforementioned four steps, to form a grain side layer thereupon.
• the kinds and amount of the resin to be applied may be properly selected and determined according to the kinds of structural fibers, the texture of base fabric, the kinds of resin employed in the third sheet material of the present invention as the insole and inner linings.
• the process of the invention permits the rapid and economical production of continuous lengths of the sheet material in any desired width, is relatively easy to control and consistently yields a high quality product.
• the material has a highly increased water retentiveneness and an extremely small so-called equilibrium moisture regain at 25 C., 65 percent R.H. as compared with conventional shoe materials, so that it has considerably increased capacity for absorbing sweat. Accordingly, even one who has a plenty of perspiration can keep ones feet in dry condition and feel.
• step outlets of product and the type of machinery.
• doctor coating, roll coating or any other conventional coatings are employable.
• leatherlike materials thus obtained have its flesh side and grain side layers resembling natural leathers and moreover, exhibit excellent moisture absorptivity, moisture exhalability, air permeability and hands comparable to natural leathers, so that they are suitable broadly for coats, chair coverings, bags, shoe uppers, wall materials, etc.
• a shoes having its insole and linings composed of the leatherlike material of the present invention can provide its inner surface with microporous polyvinyl acetal resin layers having exceedingly numerous micropores therein, so that it exhibits highly intensified capillary action with the aid of the hydrophilic properties inherent to the polyvinyl acetal resin.
• the sheet material of the present invention possesses appropriate strength even if it absorbs water and therefore, in case it absorbs a lot of sweat, it can keep its original configuration unchanged.
• FIG. shows the same lines indicating the water content with respect to the above mentioned insoles as shown in FIG. 4, being somewhat rearranged only with their parts below a water content of 67 percent.
• lines A, D and B show water exhaling abilities of the corresponding insoles A, D and B beginning at their respective water content of 40 percent, 36 percent and 53 percent, and each of the beginning points is made to accord with the point of the same value of water content on the line H for the purpose of comparison with each other.
• the leatherlike material of the present invention is extremely superior in water exhaling ability to any other conventional materials. Accordingly, the materials of the invention can provide shoes having such a wearing comfort that even though they are with water on a rainy day, they can be dried thoroughly by standing overnight and worn comfortably again on the next morning.
• FIGS. 6 and 7 show a structure of an ordinary shoe for gentlemen, wherein between outsole 110 and circumference of slipsole 111, toe cap 112, vamp 113, counter 114, toe lining 1 16 and quarter lining 1 17 are tightly fastened and secured at their circumferences.
• Toe box is indicated as 115.
• Insole or inner sole 1 18 is placed upon the slipsole l1 1, heel pad 119 is superimposed upon a heel portion, 120 is lace and 121 indicates a surface of the insole which is to be in contact with a foot.
• a leatherlike material of the invention having a continuous microporous structure comprising polyvinyl acetal, specifically polyvinyl formal may be employed to constitute at least a part of the insole 118 of the shoe as illustrated above, and further is applicable to form the tow lining 116, quarter lining 117, heel pad 119 or a sole pad (not shown in FIGS. 6 and 7).
• the microporous resin of which the leatherlike material of the present invention is composed has numerous fine projections, such as coralline branches, on the surface of its pore, so that it exhibits an increased void content as well as a tremendously large surface area per unit volume.
• the particular microstructural feature of the resin as such greatly enhances the effects and merits of the leatherlike material of the present invention.
• Moisture absorptivity A specimen was conditioned in an atmosphere having 65 percent RH. at 20 C. for 24 hours and its weight W was determined. The thus conditioned specimen was allowed to absorb moisture in a moist atmosphere having 100 percent R.H. at 30 C. for an arbitrary period of time and its weight W was weighed. Then the moisture absorptivity of the specimen is given by the following equation:
• Moisture exhalability X 100 Water content A specimen having an initial weight of W; was soaked in water at 20 C. for 24 hours, taken out of the water and after removing excess water from its surface, the weight W of the wet specimen was determined. Then the water content is calculated according to the following equation:
• part used in the examples means part by weight,” unless otherwise indicated.
• EXAMPLE I A web having a thickness of 6 mm. and a weight of 700 gJm. which had been prepared from nylon-6 staples of 1.5 denier having fiber length of 38 mm. was employed as a base fabric.
• a water soluble formalized product of polyvinyl alcohol having a degree of formalization of 20 percent by mole was prepared with a polyvinyl alcohol having an average degree of polymerization of 1,500, formaldehyde and sulfuric acid, and then a treating solution consisting of 40 parts of 10 percent solution of the above obtained formalized product of polyvinyl alcohol, 6 parts of formaldehyde of an industrial grade having its concentration of 37 percent, 5 parts of sulfuric acid of an industrial grade having its specific gravity of 50 Be and 15 parts of water was prepared in advance.
• the amount of the resin further adhered onto the fabric in the third and fourth steps was 16 percent by weight based on the fabric.
• the leatherlike material prepared by all four steps of the process of the invention shows a slight decrease with respect to the water absorbability and water vapor permeability, yet it exhibits a considerable improvement in all other mechanical properties, as compared with the intermediate product prepared by only the first and second steps of the process of the invention, so that the utility of the leatherlike material of the present invention is greatly improved.
• the leatherlike material manufactured according to the process as described in example 1 is suitable for insole and sole pad of shoes, wall linings, motor car panellings and the like.
• EXAMPLE 2 The intermediate prepared in example 1 was impregnated with 40 parts of an emulsion (comprising 40 percent of solid component) of an acrylonitrile/acrylic acid butyl ester copolymer and 60 parts of water and squeezed to retain I00 percent by weight of the treating solution based on the fabric,
• the resultant leatherlike material had desirable properties linings of shoes.
• EXAMPLE 3 The leatherlike sheet material manufactured in example 2 was sliced into sheets of 1 mm. thick, and which sheets were employed as substrates to be subjected to the fifth step according to the process of the present invention.
• a colored treating liquid which had been prepared by admixing a black toner (a pigment paste) with Crisvon (a trade name of a N,N-dimethylformamide 30 percent solution of polyurethane of 35 percent ester type, manufactured by Dainihon lnk Kogyo K.K.) was applied to the top surface of the above-mentioned substrate by 0.6 mm. thick by means of a roll coater. Then the coated sheet was introduced into water and the liquid applied thereupon was coagulated and solidified to form a grain side layer. The sheet was thereafter subjected to a drying process, followed by an embossing process whereby a leatherlike superficial appearance was imparted to the product. The amount of resin adhered onto the substrate in the fifth step was 14 percent by weight based on the substrate.
• the leatherlike sheet material thus obtained exhibited hands and feels resembling those of natural leathers, and suitable for shoe uppers, bags, chair coverings and the like.
• EXAMPLE 4 A terry composed of polyamide staples having a cut length of 5 mm. was employed as a base fabric.
• a water soluble formalized product of polyvinyl alcohol having a degree of formalization of 22 percent by mole was prepared with a polyvinyl alcohol having an average degree of polymerization of 1700, and then a treating solution consisting of 40 parts of percent solution of the above obtained formalized product of polyvinyl alcohol, 6 parts of formaldehyde of an industrial grade having its concentration of 37 percent, 5 parts of sulfuric acid of an industrial grade having its specific gravity of 50 Be and parts of 5 percent aqueous solution of potato starch was prepared in advance.
• Hydran F-24 a trade name of a water soluble polyurethane resin, containing 30 percent of nonvolatile ingredients, manufactured by Dainihon lnk Kogyo K,K.
• a treating liquid consisting of 100 parts of 30 percent N,N-dimethylformamide of S-lec BH-Z (a trade name of a polyvinyl butylal resin having an average degree of polymerization of 1600 and an average degree of butylalization of 65 percent, manufactured by Sekisui Kagaku Kogyo K.l(.) and 10 parts of butyl phthalyl butyl glycolate, in the same manner as in the fifth step of example 3, to form a grain side layer on the sheet material.
• the thus obtained leatherlike material had its properties as follows:
• the resultant leatherlike material exhibited appropriate softness and preferable hands and was suitable for clothings such as a coat, chair coverings and bags.
• a leatherlike sheet material comprising a base fabric, a resin adhering to and entirely covering the structural fibers of said fabric, said resin consisting essentially of microporous water-insoluble poly(vinyl formal) in the form of a porous unitary three-dimensional network in the fabric in a ratio by weight of poly(vinyl formal) to fabric of 1 :10 to 2:1 and a continuous layer of at least one polymer selected from the group consisting of polyurethane, polyacrylonitrile, poly(acrylic ester), polyamide, and melamine-formaldehyde polymer in an amount of the polymer of 5-100 percent by weight.
• said material being produced by impregnating said base fabric with an aqueous solution containing a water-soluble poly(vinyl (vinyl formal) having an average degree of formalization of 10-30 mole percent, heating the impregnated fabric to 50 to 130 C. to increase the formalization of said poly(vinyl formal) to yield a microporous, water-insoluble polylviny] formal) having an average degree of formalization of 50-75 mole percent and then impregnating the resultant fabric with at least one of said polymers.
• a leatherlike material as claimed in claim l wherein the ratio by weight of said poly(vinyl formal) resin to said base fabric is 1:5 to 1:1.
• a process of making a leatherlike sheet material as claimed in claim I which comprises: (1) first step of impregnating a base fabric with an aqueous solution containing water soluble polyvinyl acetal, (2) second step of heating the impregnated fabric at 50-l 30 C.
• aqueous solution further contains catalyst for acetalization comprising aldehydes and acids or their salts.
• aqueous solution further contains catalyst for acetalization and a pore forming agent.
• heating temperature in the second step is in the range of 70-100 C.

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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)
• Laminated Bodies (AREA)
• Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
• Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)

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Publications (1)

Family

ID=12925584

Family Applications (1)

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Cited By (15)

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Citations (3)

• 1968
  • 1968-07-27 JP JP5282468A patent/JPS535362B1/ja active Pending
• 1969
  • 1969-07-23 US US843990A patent/US3627567A/en not_active Expired - Lifetime
  • 1969-07-25 BR BR211045/69A patent/BR6911045D0/pt unknown
  • 1969-07-28 GB GB3783269A patent/GB1257095A/en not_active Expired
  • 1969-07-28 DE DE1938284A patent/DE1938284C3/de not_active Expired

Patent Citations (3)

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