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
  • D04H1/42—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
  • D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
• • 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
  • D04H1/425—Cellulose series
  • D04H1/4258—Regenerated cellulose series
• • 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
  • D04H1/4309—Polyvinyl alcohol
• • 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
  • D04H1/44—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/46—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
  • D04H1/48—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres in combination with at least one other method of consolidation
  • D04H1/488—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres in combination with at least one other method of consolidation in combination with bonding agents
• • 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
  • D04H1/44—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/50—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by treatment to produce shrinking, swelling, crimping or curling of fibres
• • 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
  • D04H1/645—Impregnation followed by a solidification process
• • 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
  • D06N3/0015—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 fibres of specified chemical or physical nature, e.g. natural silk
• • 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
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
  • Y10T428/24364—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.] with transparent or protective coating
• • 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
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
  • Y10T428/24438—Artificial wood or leather grain surface

Definitions

• a supple sheet material suitable as a base material for the manufacture of artificial leather comprising a non woven condensed web formed from fibers of substantially hydrophilic material, e.g., polyvinyl alcohol, and a polymer filler which has substantially no adhesion to the fibers, e.g., polyurethane.
• the filler is homogeneously distributed throughout the web and coheres at spaces between the fibers and the sheet material has a density of at least 0.5 gram per cubic centimeter at a total filler content of not more than 30% by weight, based on the weight of the sheet material. Also a method for producing this sheet material is disclosed.
• This invention relates to a supple sheet material which is particularly suitable to be used as base material for the manufacture of artificial leather. More particularly this invention relates to a supple sheet material which has properties that closely approach or even excel those of dressed animal skin used for the manufacture of natural leather and which is similar to natural leather in that it contains a maximum amount of hydrophilic fibrous material and to a method for producing such sheet material.
• British patent specification No. 804,669 discloses a process for the manufacture of a leather-like sheet material from a web of natural and/ or synthetic fibers. This process comprises the steps of impregnating the web with a solution of a given polyurethane and then subjecting it to an aftertreatment, which may or may not be carried out under pressure at an elevated temperature. The concentration of polyurethane may be considerably reduced if prior to impregnation the Web is treated with a rubbery binder such as a latex of a butadiene-acrylonitrile copolymer.
• the resulting web is processed into a leather-like sheet material having a density of approximately 0.4 gram per cubic centimeter; the pick-up on the web of polyurethane, or polyurethane and rubbery binder being on an average 100% by weight or more on the weight of the web.
• PVA fiber sheets in which the fibers themselves serve as binder.
• Use is made of PVA fibers which may be crimped or uncrimped and which owing tothe treatment applied (stretching, hot stabilizing and shrinking) are capable of swelling in hot water without their structure being changed and which, when subsequently dried, with or without pressure, will adhere to one another.
• a binder may be added in this process.
• the resulting sheets which may or may not be subjected to a formalization treatment, have a wide field of application. They may be used, for example, as substitutes for various sorts of paper, felts, table linen, etc.
• Netherlands patent application 6511390 describes the manufacture of a polyvinyl alcohol-fiber web which is particularly suitable to serve as a substrate for artificial leather.
• the base material is a web or mat comprising water-shrinkable PVA-fibers, which is successively contacted with an aqueous liquid, subjected to a formalization treatment, and so dried that practically no sticking together of the polyvinyl alcohol fibers will occur.
• the web when still dry, is preferably subjected to a needle-punching treatment and the aqueous liquid should contain a water-soluble polymer filler which (in a subsequent coagulating bath) is precipitated in the web.
• the web may be impregnated and/or coated with a polyurethane composition.
• Suitable methods for impregnating a fibrous substrate with a homogeneously distributed and porous polymer filler having no adhesion to the fibers are described in, inter alia, the US. Pat. 3,067,482 and the Netherlands patent application 6511220.
• the method described in the US. Pat. 3,067,482 comprises applying a polymer solution such as polyurethane in dimethyl formamide (DMF), and treating the impregnated substrate with a liquid miscible with the solvent, for instance water, which causes the polymer to coagulate and which serves to remove the solvent in a washing treatment.
• a polymer solution such as polyurethane in dimethyl formamide (DMF)
• a liquid miscible with the solvent for instance water
• the polymer solution is premixed with a small amount of a non-solvent, for instance, water. Thereafter the polymer is co'agulated by a decrease in temperature, and the solvent and the non-solvent are removed.
• this invention provides a method of obtaining such a base material.
• this invention contemplates a supple sheet material for the manufacture of artificial leather made from hydrophilic fibers, which is characterized in that it has a density of at least 0.5 gram per cubic centimeter at a total filler content of not more than 30%, but preferably of from 10 to 20%, calculated on the weight of the sheet.
• hydrophilic fibers as used herein is meant to designate fibers which when placed in a moist atmosphere of 20 C. having a relative humidity that changes from 50% to will show a moisture pick-up of at least 7% of their own weight.
• Such fibers usually have a swelling value of at least 25%, but generally of 40% or higher.
• the swelling value is defined as the percentage moisture retained by the water-impregnated dry fibers after they have been subjected to a relative centrifugal force of 1,500 grams for minutes.
• the properties of the supple sheet material of this invention closely approach, or even excel, those of animal skin used for the preparation of leather. This is particularly true of the important properties such as strength, elongation at break, modulus, tear strength, and water vapor pick-up.
• the unique properties of the supple sheet material are due to the fact that the greater part of the sheet material, namely, at least 70%, is formed by densified hydrophilic fibrous material, and the filler content has been kept as low as practically possible.
• the moisture-absorption capacity of the sheet material and consequently its ability to swell and shrink, depending on the moisture content, provides the sheet with a suppleness that greatly contributes to wearing comfort.
• the starting materials used for the manufacture of the sheet material of this invention comprise fibers of substantially hydrophilic material such as polyvinyl alcohol (PVA) and regenerated cellulose (rayon), which fibers, while in the form of a condensed nonwoven web or mat are consolidated into a sheet having the desired properties with the aid of a polymer filler that has no adhesion to the fibers.
• substantially hydrophilic material such as polyvinyl alcohol (PVA) and regenerated cellulose (rayon)
• This invention also therefore contemplates a method for producing a supple sheet material suitable as a base for artificial leather which comprises forming a non-woven web of the substantially hydrophilic fibers, shrinking the fibers to effect initial densification of the web, subjecting the shrunk fibrous web to pressure at an elevated temperature to effect further densification, i.e., to provide a density of at least 0.5 gm./cm. and thereafter introducing a polymeric filler that has substantially no adhesion for the fibers into the highly densified web; the amount of filler not being greater than 30% by weight based on the weight of the sheet material.
• the method of this invention includes the following processing operations in order:
• a web of hydrophilic fibers preferably water-shrinkable crimped PVA fibers, is formed and, if necessary, subjected to a needle-punching operation to improve its coherency.
• Retractable PVA fibers of this type are known and may be obtained, inter alia, by the methods described in the heretofore described Netherlands patent application 6511390 and the US. Pat. 2,962,762.
• the fibers preferably each have a denier of from 0.5 to 2.5, and are advantageously out to lengths of about 40 mm.
• the fiber web is preferably subjected to a shrinking treatment.
• shrinking is efiected by treating the webs with water at a temperature below about 70 C.
• the shrunk web is, when necessary, dried at a temperature not higher than 70 C.
• a binder may be introduced into the web.
• Suitable binders include dispersions or a variety of solutions such as reactive rubber latices, cyanates, alginates, carboxy methyl cellulose, and the like. It will be appreciated that the binding together of the fibers by a binder need only be of a temporary nature since the binder only serves to maintain the high fiber density obtained in the subsequent processing step or operation until the filler has been introduced.
• the shrinking treatment is carried out under conditions such that the fibers themselves will locally and temporarily bond together, then the use of binders is not necessary at all.
• the concentration and the amount thereof should be so chosen that the dried web will not contain more than 10% by weight of the binder.
• the dried web is now pressed at an elevated temperature-for instance, by passing it between heated rollsto activate the binder and/ or the fibers with simultaneous densification of the web to a value of 0.5 g./cm. or higher.
• the pressing temperature is dependent on the binder applied, if any, but the temperature is usually C. or higher.
• the resulting web is formed by a highly densified hydrophilic fibrous material which is kept together at the bonding points throughout the web, and particularly at the fiber crossing points.
• a highly densified hydrophilic fibrous material which is kept together at the bonding points throughout the web, and particularly at the fiber crossing points.
• the polyurethane filler may be introduced by any one of the known methods, as described in, inter alia, the US. Pat. 3,067,482 and the Netherlands patent application 6511220.
• the aforedescribed method of impregnating with a solution of polyurethane in a mixture of a solvent, for instance, dimethylformamide, and a small amount of a non-solvent, for instance, water, followed by precipitating and removing the solvent and the non-solvent, is particularly suitable for obtaining a homogeneously distributed and porous filler which has substantially no adhesion to the fibrous material.
• the concentration and the amount of the impregnant are invariably so chosen that the total filler content of the web should not be higher than 30% by weight. It is preferred that the amount of filler introduced into the web should not be higher than of from 10 to 20% by weight.
• the total content of binder and filler must not be higher than 30% by weight, based on the weight of the sheet or Web.
• variable factors and conditions are the retractability and the degree of crimp of the hydrophilic fibers, the type of binder, the application of aqueous or non-aqueous binder dispersions (if use is made of a non-aqueous dispersion it is, as a rule, desirable that the web should be pre-shrunk in water), the pressure and temperature at which the web is densified and bonded, and the like.
• the supple sheet material of this invention forms an excellent base material to be further processed into artificial leather.
• the sheet material may in a conventional manner he fatliquored, hydrophobized, staked, buffed and/or split, and it may be coated by successive napping and spraying. It should be added that the fat-liquoring and hydrophobizing substances also may be introduced during the preceding processing steps. In a final processing step, usually a varnish top coat is applied.
• Use may also be made of different finishing methods known from the synthetic leather technique, more particularly different methods of applying various coatings ineluding, if desired, a binder layer.
• EXAMPLE I After being given a needle-punching treatment, a web of crimped 1.3 denier polyvinyl alcohol fibers (length 40 mm.) weighing 400 gun/m. is shrunk in water of about 50 C.
• the shrunk web is dried and then pressed for 30 seconds between the platens of a press at a temperature of 120 C. and at a pressure of approximately 6 kg./cm.
• the condensed web has a density of about 0.6 g./cm.
• the web is subsequently immersed in a 15 %-solution of a polyurethane (Estane 5707 F1, of B. F. Goodrich Chemical Company) in a mixture of 95 parts dimethyl formamide (DMF) and 5 parts water at 50 C.
• a polyurethane Estane 5707 F1, of B. F. Goodrich Chemical Company
• DMF dimethyl formamide
• the excess liquid is removed by passing the web between squeeze rolls after which the web, while being cooled down to 5 C., is washed in water containing a small amount of DMF, followed by drying it at 50-70 C.
• the resulting supple sheet material has a density of 0.60 gm./cm. and contains approximately 11% by weight of the polyurethane that has no adhesion to the fibers.
• EXAMPLE II A shrunk and dried web produced in the manner in Example I is pressed for 30 seconds between the platens of a press at a temperature of 120 C. and at a pressure of approximately 5 kg./cm. The compressed web has a density of 0.57 gm./cm.
• the sheet material After the additional treatment described in Example I, the sheet material has a density of 0.58 gar/cm. and a polyurethane content of 15% by weight.
• EXAMPLE III the needle-punched web of Example I is impregnated with a %-dispersion of a reactive acrylate rubber (Hycar 2679, of N.V. Chemisehe Industrie AKU-Goodrich) at about 50 C. Owing to this treatment the surface area of the web shrinks by a factor of about 2.
• a reactive acrylate rubber Hycar 2679, of N.V. Chemisehe Industrie AKU-Goodrich
• the impregnated web is dried at 45-50 C. and is found to have a binder content of about 8% by weight.
• the dried web is then pressed for 30 seconds between the platens of a press to a density of 0.50 gm./crn. at a temperature of 120 C.
• the web is filled with polyurethane, which is now done by coagulation in DMF-containing water at 20 C.
• the resulting sheet is found to have a density of 0.53 gm./cm. and a binder content and filler content of 8% by weight and 16% by weight, respectively.
• EXAMPLE IV A binder-impregnated web is produced following the procedure described in Example III. The web is slightly squeezed and passed through a /2%aqueous solution of triethyllauryl-ammonium chloride (destabilizer for the rubber dispersion). The web thus treated is again slightly squeezed and then dried at 45-50 C.
• the dried web is compacted to a density of 0.6 g./cm. and filled as described in Example III.
• the resulting sheet has a density of 0.60 g./cm. its binder content and filler content being 8% by weight and 10% by weight, respectively.
• EXAMPLE V A shrunk and dried web produced as described in Example I is treated at room temperature with the binder dispersion described in Example III, and then pressed to a factor of approximately 2 and dried at 40-45 C.
• the dried web is pressed for 30 seconds between the platens of a press to density of 0.75 g./cm. at a temperafurture of 120 C. and then cured for 10 minutes at 120 C.
• the web is impregnated with a 20%-aqueous emulsion of a nitrile rubber (Hycar 1562, of N.V. Chemisehe Industrie AKU-Goodricht) which has no adhesion to PVA-fibers.
• a nitrile rubber Hycar 1562, of N.V. Chemisehe Industrie AKU-Goodricht
• the excess liquid is squeezed out, after which the web is dried at 45-50 C.
• the resulting sheet has a density of 0.58 g./cm. a binder content of 8% by weight and contains 18% nitrile rubber filler.
• EXAMPLE VI A web of crimped 1.5 denier rayon fibers (length 40 mm.) weighing 600 gm./m. is formed and, after needling, impregnated at room temperature with the binder dispersion described in Example III.
• the web is dried at 65-70 C. and is then found to have a binder content of about 14% by weight.
• the dried web is subsequently pressed for 30 seconds between the platens of a press to a density of 0.78 gm./cm. at a temperature of 120 C.
• the condensed web is filled with polyurethane as described in Example III.
• the resulting sheet has a density of 0.55 gn1./em. a binder content of 14% by weight and a filler content of 14% by weight.
• EXAMPLE VII A shrunk and dried web produced in the manner described in Example I is immersed in a 4%-solution in ethylacetate of a reactive macroisocyanate (a mixture of Imprafix and Impranil which are products of Bayer).
• the excess liquid is removed followed by evaporation of the solvent.
• the dry web is then kept for 24 hours at room temperature.
• the 'web is pressed for 30 seconds between the platens of a press to a density of 0.7 gm./cm. at a temperature of 120 C.
• the condensed web is filled with polyurethane as described in Example III.
• the resulting sheet has a density of 0.70 g./cm. a binder content of 8% by weight and a filler content of 10% by weight.
• EXAMPLE VIII A needle-punched web produced in the manner described in Example I is shrunk in a 2% aqueous alginate solution of 50 C. The excess liquid is removed, after which the web is dried at 4050 C. The binder content is found to be approximately 7% by weight.
• the dried web is pressed to a density of 0.6 gm./cm. at a temperature of 120 C.
• the web is then filled with polyurethane as described in Example III, after which the resulting sheet is found to have a density of 0.58 g./cm. and a filler content of 14% by weight.
• the initially introduced binder is found to be completely removed by the washing treatment.
• EXAMPLE IX The sheet materials produced in the preceding examples, i.e., Examples I to VIII are further processed into artificial leather and evaluated. In each case the sheet materials provide outstanding artificial leather substrates.
• the product according to the present invention offers a considerable improvement.
• the novel products are found to have a water vapor pick-up of 450 or more, and at a higher density and a lower filler content, which are to be preferred, this value is usually at least as high as 650 (such sheet materials are shown in Examples I, II, IV and VII).
• the properties relating to the strength of the material compare with or are superior to those of both natural leather and the known artificial leather products. It has been found that the product according to the present invention generally shows the following values (both in longitudinal and transverse direction): strength 23-35 kg./cm., elongation at break 7080%, modulus at 10% elongation 5-6 kg./cm., mean tear strength 8 kg.
• fibers as used herein is meant to designate staple fibers and continuous filaments.
• Hydrophilic material in the form of grindings or other particulate matter may also be introduced into the fibrous web.
• the product according to the invention may be made to contain a small amount of non-hydrophilic fibers such as those of nylon, polyester or polypropylene.
• the amount of non-hydrophilic fibers to be admixed must be kept small, and, in general, is less than 5%.
• a supple sheet material suitable to be used as base material for the manufacture of artificial leather which comprises a non-woven condensed web formed from fibrous material consisting essentially of substantially hydrophilic polymeric fibers, and a polymer fillter which has substantially no adhesion to said fibers, said hydrophilic polymeric fibers having a moisture pick-up of at least 7% of the weight of said fibers when placed in a moist atmosphere with a temperature of 20 C. and a relative humidity that changes from 50% to 95%, said filler being homogeneously distributed throughout said web and cohering at spaces between said fibers, and said sheet material having a density of at least 0.5 gram per cubic centimeter and a total filler content of not more than 30% by weight based on the weight of the sheet material.
• filler content is in an amount of from 10 to 20% by weight.
• filler is a polyurethane.
• hydrophilic fibers are selected from the group consisting of polyvinyl alcohol and regenerated cellulose fibers.
• the supple sheet material of claim 1 further comprising a binder by which said fibers are bonded together at randomly distributed fiber crossing points; the total amount of binder and filler not being more than 30% by weight, based on the weight of the sheet material.
• the supple sheet material of claim 5 in which said sheet material contains from 5 to 10% by weight of the binder and from 10 to 20% by weight of the filler.
• supple sheet material of claim 1 in which a sheet having a thickness of 1 to 2 mm. exhibits a water vapor pick-up of at least 450 mg./ cm. when placed in said moist atmosphere.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical 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)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19802711

Family Applications (1)

Country Status (6)

Cited By (8)

Families Citing this family (4)

• 1968
  • 1968-02-09 NL NL6801826A patent/NL6801826A/xx unknown
• 1969
  • 1969-01-27 US US794404*A patent/US3597307A/en not_active Expired - Lifetime
  • 1969-02-03 FR FR6902338A patent/FR2001438A1/fr not_active Withdrawn
  • 1969-02-05 GB GB6149/69A patent/GB1260154A/en not_active Expired
  • 1969-02-05 DE DE19691905551 patent/DE1905551A1/de active Pending
  • 1969-02-07 ES ES363371A patent/ES363371A1/es not_active Expired

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