Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H5/00—Special paper or cardboard not otherwise provided for
  • D21H5/12—Special paper or cardboard not otherwise provided for characterised by the use of special fibrous materials
• • 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
• • 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
  • D06N3/0056—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by the compounding ingredients of the macro-molecular coating
  • D06N3/0061—Organic fillers or organic fibrous fillers, e.g. ground leather waste, wood bark, cork powder, vegetable flour; Other organic compounding ingredients; Post-treatment with organic compounds
• • 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
  • D06N3/12—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 otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins
  • D06N3/14—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 otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins with polyurethanes
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/30—Multi-ply
• • 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
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
  • Y10T428/24994—Fiber embedded in or on the surface of a polymeric matrix
  • Y10T428/249941—Fiber is on the surface of a polymeric matrix having no embedded portion
• • 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
  • Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• • 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
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2904—Staple length fiber
• • 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
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
  • Y10T428/31558—Next to animal skin or membrane

Definitions

• This invention relates to leather substitutes and compositions useful in the preparation thereof. More particularly the invention relates to leather substitutes based on water-laid sheet material formed of a major portion of globular, nonfibrous elastomeric material and a minor portion of fibrous material.
• the constructions of the present invention are permeable to air and moisture vapor, are strong, tough, porous and have good flex endurance.
• the materials further have the appearance and general performance characteristics of leather, preferably displaying a delayed elastic recovery as contrasted to either a snappy rubbery characteristic or a permanent set of the type displayed by some resinous materials.
• the polymeric components of the sheet materials are sufiiciently resistant to flow at ambient temperatures to preclude loss of porosity and moisture permeability under the temperature and stress conditions normally encountered by footwear.
• the materials further have significantly higher moisture regain value than do leather substitutes based wholly on synthetic polymers.
• a water slurry in which the solids are about 50 to percent by weight globular elastomeric polyurethane particles and 20 to 50 percent fibrous material, at least /3 of the fibrous material being leather fiber and substantially the remainder ibeing staple fiber such as nylon and preparing a water-laid sheet therefrom.
• elastomeric polyurethane compositions of the type hereinafter described, particularly when coagulated from a latex, result in a dispersion containing globular (i.e. nonfibrous) polymer particles having properties such that the same can be formed into a useful sheet on a foraminous surface even when used in compositions containing a major proportion of the globular polymeric particles and a minor portion of fibrous material.
• the fibrous component of the composition should be at least onethird by weight tanned leather fibers, the remainder of the fibrous component being substantially composed of staple fibers, preferably of a high strength flexible type such as nylon, polyethylene terephthalate, polypropylene or acetal copolymers (such as those based on trioxane).
• the total composition should, in any event, contain a minimum of at least about 10 percent by Weight leather fibers, 20 to 25 percent leather fibers being preferred.
• the staple fibers impart high tensile and tear strength and flex endurance to the sheet material, and serve to make the sheet more porous.
• the elastomeric polyurethane materials useful in forming the sheet materials of the present invention are present in the form of discrete globular particles in the 1-100 micron average particle size range. Even though such particles may tend to agglomerate, the individual particles are readily identifiable as falling within the abovementioned size range.
• These polyurethane particles are preferably formed from latices based on polyetherurethane or polyurethane-urea elastomers.
• Other urethane elastomers for example, polyesterurethanes having the hereinafter specified minimum physical properties are also useful. Examples of the suitable latices are those disclosed in U.S. Patent 2,968,575, issued Jan. 17, 1961 (Mallonee), and British Patent No. 880,665, issued Oct.
• the preferred polyurethanes are those formed from the reaction product of an organic diisocyanate with a polyalkylene ether glycol or polyol chain extended with a compound having at least two active hydrogen atoms, especially a diamine such as piperazine, dimethyl piperazine, hydrazine, methylene bis-3-chloro-4-aniline, 2,4- tolylene diamine, ethylene diamine, ethanol amines, poly alkylene ether diamines or the like.
• a diamine such as piperazine, dimethyl piperazine, hydrazine, methylene bis-3-chloro-4-aniline, 2,4- tolylene diamine, ethylene diamine, ethanol amines, poly alkylene ether diamines or the like.
• polyalkylene ether glycols or Water may be used as chain extending agents.
• leather substitutes having outstanding characteristics can be prepared by using chain-extended polymers formed by the reaction of isocyanate terminated prepolymers of polyalkylenether glycols and organic diisocyanates with the above-noted diamines to provide a polyurethane having a number average molecular 'weight of at least about 10,000.
• the elastomeric polyurethane materials can be formed into globules suitable for sheet formation on a paper machine by coagulation from a latex under controlled conditions, hereinafter exemplified, or alternatively, without going through a latex stage, by a direct reaction in aqueous medium under suitable conditions of an isocyanateterminated prepolymer with Water or a diamine or by other techniques providing the desired globular particle.
• Globular polymer particles may be prepared by adding one or more flocculating agents to a latex to cause coagulation.
• flocculating agents are alum, sodium carbonate, sodium chloride, karaya gum, locust bean gum, and the like. These agents may be added t the aqueous latex either prior to or subsequent to admixture with the fibrous materials.
• the fibrous constituent of the constructions must be at least one-third weight of leather fibers.
• the presence of at least about percent by weight of the total construction of leather fibers imparts to the construction a leather-like feel and appearance and a high moisture regain value and assists in the formation of a breathable sheet which has a surface receptive to finishing by standard leather finishing techniques.
• the leather fibers are preferably derived from leather scrap comminuted to fibrous form, the degree of comminution of the fibers being varied in accordance with the properties desired in the final sheet material. Fibers ranging in length from about 0.25 to about 2 millimeters have been found preferable. Shorter fibers such as beater-treated leather fiber generally result in a smoother sheet surface. But unbeaten chrome-tanned fibers are preferred where higher strength is desired. Vegetable tanned fibers have also been found suitable.
• the staple fibers significantly improve tensile strength, tear strength and flex durability as well as breathability of the leather substitutes of the invention, thereby enabling their use as shoe uppers materials and the like.
• polyamide e.g., nylon fibers
• high strength products can also be prepared using fibers of wholly synthetic polymers such as polypropylene, polyesters, e.g., polyethylene terephthalate and acetal copolymers (e.g., those based on trioxane).
• wholly synthetic polymer as the term is used herein is meant polymeric material synthesized by man as distinguished from polymeric products of nature or derivatives thereof.
• High strength fibers generally have a tensile strength of at least 4 gm. per denier.
• the high strength flexible fibers should form at least 10 percent of the weight of the construction, 10 to 20 percent being preferred.
• Other fibers such as rayon, cellulosic fibers, glass, asbestos, and the like may be used to vary the physical properties of the sheet.
• the staple fibers preferably are in the size range of from 1 to 6 denier and range in length from A3 to /2 inch, ,41 to inch being preferred. Minor amounts (e.g., 1 percent by weight of the sheet) of fibrids may also be included as part of the fibrous constituents of the sheet.
• Sheets having smoother surfaces may be formed by increasing the proportion of leather fibers in the fibrous component at least near the top surface of the sheet.
• a typical leather substitute may be formed from a base sheet containing 50 percent to 80 percent polyurethane particles, the remainder being fibrous material preferably present in the approximate proportion of two parts leather fibers to one part nylon or other staple fibers upon which is superimposed another layer or ply having approximately the same or higher polymer content but in which substantially all (e.g., at least 85 percent) of the fibers are leather.
• Such constructions can be prepared by forming the individual layers separately on a papermaking machine and then laminating the same, generally using adhesives and/or heat and pressure, or more preferably by using paper making apparatus having two or more head boxes or cylinders to form a multiply composite sheet.
• a substrate layer will contain 60 to 70 percent elastomeric polyurethane, to 30 percent leather fibers and 10 to percent staple fibers maintaining an approximate ratio of leather to staple fibers of 2 to 1.
• An intermediate ply may be formed comprising for example, 75 percent globular elastomeric polyurethane material and percent nylon fibers and a top ply may comprise about 75 percent elastomeric polyurethane materials and 25 percent leather fibers.
• multiply sheet When hot pressed the multiply sheet is typically mils thick.
• the composite sheet ma then be ground or buffed to smooth the surface and reduce the thickness to about 60 to 65 mils.
• a multiply construction of this type is then in a form suitable for finishing by conventional leather finishing techniques.
• An alternative method of forming a leather substitute using the water-laid sheet materials of the present invention involves the application with or without an adhesive of a microporous polymeric layer, for example of the type disclosed in Holden US. Patent 3,100,721, issued Aug. 13, 1963 to a substrate layer described in the preceding paragraph.
• the slurry from which the sheets are formed should have a consistency approximately that normally used in papermaking procedures.
• the degree of mixing and smoothness of the slurry can be improved by beater treatment.
• Slurries of the type described can be formed into a water-laid sheet using Fourdrinier machines, simple cylinder machines, or modified cylinder machines such as those which are vacuum assisted and have a head box rather than a vat.
• Laboratory size sheets may be formed by depositing the slurry on any suitable foraminous surface, such as a screen or felt, to form hand sheets.
• the polyurethanes which result in useful leather substitutes must be elastomeric and resistant to creep or flow at ambient temperatures. They generally have been found to have a brittle temperature of about -l0 C. or lower, and preferably -30 C. or lower.
• the heat distortion temperature as hereafter defined should be at least +40 C. or preferably at least +75 C.
• the polyurethane should have a tensile of at least 300 p.s.i., more preferably at least 1000 p.s.i., and should have an elongation at break of at least percent, preferably at least 300 percent.
• the modulus stress at 100 percent elongation
• prepolymers bearing terminal isocyanate groups may be prepared by adding one or more polyalkylenether glycols, polyalkylenether diamines or hydroxy terminated polyesters to an excess of organic diisocyanate and by carrying out their reaction in a temperature range from about room temperature to about 100 C.
• Another procedure is to react the diisocyanate with an excess of polyalkylenether glycol, polyester glycol or polyalkylenether diamine so as to prepare the dimerized glycol or diamine, and then cap this material with isocyanate groups, i.e., add it to an excess of diisocyanate to form a prepolymer having terminal isocyanate groups.
• Reactive prepolymers such as these may subsequently be converted to the desired polyurethanes of this invention by reaction with compounds having at least two reactive hydrogen atoms.
• active hydrogens as the term is used herein, is meant hydrogens which display activity according to the Zerewitinoff test described in J.A.C.S., 49, 3181 (1927). Typical groups are hydroxyl, carboxyl, primary or secondary amino, and mercapto groups.
• organic diisocyanates may be used in the preparation of prepolymers for use in the invention. Because of their ready availability and the fact that they are liquid at room temperature, mixtures of the 2,-4- and 2,6-toluene diisocyanate isomers are preferred.
• Other preferred d-i isocyanates are 4,4'-diphenylene methane diisocyanate, and 3,3-dimethyl-4,4-diphenyl diisocyanate.
• useful aromatic diisocyanates include paraphenylene diisocyanate, meta-phenylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate.
• Suitable aliphatic or cycloaliphatic diisocyanates include the simple alkyl diisocyanates such as hexamethylene diisocyanate as well as more complex materials such as bis(Z-isocyanatoethyl)fum arate, bis(2-isocyanatoethyl)carbonate, bis(2-isocyanatoethyl)-4-cyclohexene 1,2- dicarboxylate, bis(2-isocyanatoethyl) 1,4,5,6,7,7-hexachloro-S-norbornene 2,3-dicarboxylate.
• Polyalkylenether glycol or polyols used in preparing such prepolymers have molecular weights generally ranging from about 300 to about 5,000 and preferably from about 400 to about 3,000, the more resilient polymers normally being obtainable from higher molecular weight glycols.
• Examples of such polyalkylenether glycols are polyethylenether glycol, polypropylene ether glycol, polytetramethylene ether glycol and higher polyalkylenether glycols. These polyether glycols are prepared by well known ring opening or condensation polymerizations. When these polyols contain recurring oxyethylene groups, the total welght fraction of such oxyethylene groups should be controlled since this structure tends to confer water sensitivity to the finished product.
• Other suitable polyols include castor oil, hydroxyl terminated polybutadiene and hydroxyl terminated vinyl polymers, preferably in the SOD-5,000 molecular weight range.
• Polyalkylenether diamines prepared from polyglycols, such as polypropylene glycol, may also be used to prepare useful polyurethanemreas, as described in US. Patent 3,179,606.
• Such diamines usually have molecular weights from about 1,000 to about 10,000.
• Polyester glycols or polyols may be used alone or together with polyether glycols or polyols in the preparation of the polymers for use in this invention.
• Polyester glycols or polyols may be prepared for example by reacting dicarboxylic acids, esters or acid halides with simple glycols or polyols.
• Suitable glycols are polymethylene glycols, such as ethylene, propylene, tetramethylene, decamethylene glycols, substituted polymethylene glycols, such as 2,2-dimethyl-1,3-propane diol, and cyclic glycols, such as cyclohexanediol.
• Polyols such as glycerine, pentaerythritol, trimethylol propane and trimethylol ethane, may be used in limited amounts to introduce chain branching into the polyester. These hydroxy compounds are reacted with aliphatic, cycloaliphatic or aromatic dicarboxylic acids or lower alkyl esters or ester forming derivatives thereof to produce polymers bearing terminal hydroxyl groups, having melting points less than about 70 C., and being characterized by molecular weights in the same approximate range as for the aforementioned polyalkylene ether glycols; preferably the molecular weights are from about 400 to about 4,000 and more preferably from about 1,000 to about 2,000.
• Suitable acids are, for example, succinic, adipic, suberic, sebacic, phthalic, isophthalic, terephthalic and hexahydro terephthalic acids and the alkyl and halogen substituted derivatives of these acids.
• a prepolymer can be carried out with or without solvents, although the presence of solvent may often facilitate mixing and handling.
• solvents which are inert to isocyanates may be used, such as toluene, xylene, etc.
• Chain extension of the prepolymer may be carried out in solution, using such highly polar solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methyl pyrrolidone, etc.
• the prepolymer may be chain extended with water or polyamine during the emulsification process, as in the procedure of Mallonee, US. Patent 2,968,575; or Wyandotte, British Patent 880,665.
• an emulsion can be prepared by pouring a polymeric solution slowly into water containing suitable dispersing agents with vigorous agitation. The solvent contained in the polymer can be allowed to remain in the emulsion or removed by distillation if the emulsion is sufliciently stable.
• Emulsions may be treated with alum, salt or other agents to produce the coagulated particles desired for this invention.
• Agents such as Na CO are also prefer ably added to control the pH of the mixture to optimize coagulation conditions.
• the pH, type and amount of precipitating agents, etc. should be selected according to the type of emulsifiers, stabilizers, etc., present in the latex. In such cases the individual coagulated particles usually have a number average particle size between about 1 and 5 microns.
• Another method of coagulation involves freezing the latex.
• the globular particles desired for this invention may be prepared directly during the polymerization step, or they may be formed by taking a solution of the polymer and adding it to a nonsolvent with stirring.
• the globular particles are usually larger than those formed by the coagulation of latices, and may range from 2 to microns in diameter, although they usually have a diameter of 5 to 30 microns. It will be apparent that, although the polyurethane particles can be formed in various ways, the particle size must be controlled within the earlier mentioned limits.
• the prepolymers before chain extending, or the emul- 7 8 sions before coagulation, or the polymer solutions before Excess water was blotted from the hand sheet which was precipitation, or the coagulated globular particles after then removed from the wire.
• the hand sheet was placed they are formed, can be modified with other ingredients between two blotters and pressed in a Meade press at such as surfactants, plasticizers, dyes, pigments, minor 35 lbs. per inch for 1 minute.
• the sheet was removed from amounts of other compatible polymers, or agents which 5 the press and dried on a Williams sheet drier at surface provide light, heat, or oxidative stability, and the like, as temperatures of about 230 to 240 F.
• the sample containing only 40% polymer was a loose of organic diisocyanate and polyalkylene ether glycol fibrous porous material useful for only such applications chain extended with piperazine (a film cured 10 min. at as insoles, gaskets or the like.
• the 50:50, 60:40, and 121 C. had a tensile strength of 4,190 p.s.i., a 100% 70:30 samples all formed materials suitable as base sheets modulus of 240 p.s.i., elongation at rupture of 580 perfor the formation of shoe uppers, the density and rubberycent, and a Shore A hardness of 55). ness of the sheets increasing with increasing polymer con- 30 ml.
• Example I 701 glass fiber 731 6 l 67 37 288 200 All of the hand sheets were remarkably similar in appearance and general feel to that of Example I, which contained the nylon staple fibers.
• all of the sheets made with fibers other than rayon were inferior to the sheet of Example I made with nylon in piping.
• a urethane prepolymer was prepared by mixing 239 parts of an 80:20 mixture of 2,4- and 2,6-toluene diisocyanate and 1,340 parts polyoxypropylene glycol of molecular weight about 2000 (Hydroxyl No. 57.5) in a dry nitrogen purged 3-liter reaction vessel. The mixture was heated to 90 to 95 C. for 2 hours during which time it was stirred slowly.
• a polymer dispersion was formed by mixing 250 ml. H O, 1.3 gm. KOH, 1.3 gm. polyvinyl pyrrolidone and 1.2 gm. ethylene diamine in a 2-liter resin flask with an Eppenbach Homo-Mixer. 70 gm. of the prepolymer mixed with 4 gm. oleic acid was added and mixing was continued for 1 minute. The mixture was transferred to a 1 pint round bottle which was placed on a roller revolving at 2 revolutions per second for minutes. A dispersion of globular particles ranging in size from about 8-15 microns was obtained.
• EXAMPLE V The prepolymer of Example IV was chain-extended with hydrazine rather than ethylene diamine, and emulsified with a compound formed of 10% polyoxyethylene and 90% polyoxypropylene (Wyandotte Pluronic L 61); the molecular weight of the propylene base of this emulsifier is 1,750 and of the total, therefore, 1,930,
• Example IV 250 cc. H O, 0.5 gm. of hydrazine hydrate and 2 gm. of Pluronic L 61 were stirred in a 2 liter resin flask and a mixture of 60 gm. of prepolymer and 2 gm. of Pluronic L 61 were added as in Example IV. An emulsion was obtained.
• Example IV the procedure and the proportion of ingredients were the same as in Example IV except that 50 gm. of sodium chloride in 500 cc. of water were added after adding the latex to cause coagulation of the latex. Sheet properties are given in Table III.
• the batch was cooled and dropped into a 3,000 gallon tank containing 5,085 pounds of an :20 mixture of 2,4- and 2,6-toluene diisocyanate, maintained at a temperature below 170 to 180 F.
• the final viscosity was about 15,000 cps. at 25 C. and the isocyanate equivalent was 445.
• Coagulation of the emulsion and preparation of the sheet containing leather and nylon fibers was the same as for Example V.
• Sheet properties are given in Table III.
• EXAMPLE VII Into a 200 gallon reaction vessel equipped with a gas purge were placed 1,558 pounds of an 80:20 mixture of 2,4- and 2,6-tol-uene diisocyanate and 785 pounds of polypropylene glycol 400. The reaction temperature was kept below 145 F. by cooling. After reaction, the batch was cooled to and 157 pounds of a triol prepared from trimethylol propane and propylene oxide and having a molecular weight of from 420 to 450 were added. The
• An emulsified polymer was formed by mixing 250 ml. of water, 1.3 gm. of KOH, and 0.6 gm. of 64% hydrazine in water in a 2-liter resin flask equipped with an Eppenbach Homo-Mixer. 70 gm. of the above prepolymer 1 1 mixed with 4 gm. of oleic acid was added and mixing was continued for 1 minute. The mixture was transferred to a 1 pint round bottle which was placed on a roller at 2 revolutions per second for minutes. A stable latex was obtained.
• a sheet was formed as in Example V. Properties of the sheet are given in Table III. The sheet showed no sign of failure after 500,000 flexes on a Newark Leather Finish 'Co. flex tester. The sheet was tested after air drying and after placing in an oven at 280 F. for 1 hour. The effect of heat to help unify the sheet, probably by improving the adhesion between the polyurethane and the fibers without harming the porosity, is shown by the data given in Table IV. When heating was tried in a press using zero ram pressure, the surface was fused sufficiently to reduce the porosity to a considerable extent.
• EXAMPLE VIII Two prepolymers were used, the first being that of Example IV.
• the second prepolymer was a triol prepared as follows: 458.2 parts of a :20 mixture of 2,4- and 2,6-toluene diisocyanate and 2597 parts of a 1,000 molecular weight triol prepared from glycerine and propylene oxide were stirred slowly at 73 C. for 2 hours under a nitrogen purge to form a product having an isocyanate equivalent of 1175.
• An emulsion was formed by mixing gm. of each of the two prepolymers and processing the same as in Example VII.
• Sheet preparation was the same as in Example V and sheet properties are given in Table III. After 640,000 flexes on a Newark Leather Finish Co.
• Example V (designated VIII-B). This sheet was tested after drying at room temperature, and after heat treatment, with results similar to those obtained in Example VII as seen in Table IV.
• EXAMPLE IX 1,000 parts of a blend of 0.8 mole of polytetramethylene ether glycol (mol. wt. 1,060) and 0.2 mole of polyproplyene glycol (mol. wt. 1,080) were added to a distilling flask together with 250 parts of isooctane. 135 parts of the isooctane were distilled off and the batch cooled to 70 C. 245 parts of an 80:20 mixture of 2,4- and 2,6- toluene diisocyanate were added and the heat of reaction raised the temperature to 90 C. where it was held for 2 /2 hours.
• Example VIII 60 gm. of the above prepolymer and 10 gm. of the triol prepolymer described in Example VIII were emulsified according to the procedure given in Example VII and a sheet prepared as in Example V. Sheet properties are reported in Table III. After 560,000 flexes on a Newark Leather Finish Co. flex tester the sheet showed no sign of failure.
• EXAMPLE X Into a 25 gallon hot oil heated kettle were added pounds of adipic acid and 37.6 pounds of neopentyl glycol. Enough toluene was added to fill the decanting system which was purged with inert gas. The batch was heated and water was removed azeotropically until the acid number was reduced to zero. The batch was cooled to 300 F., and the entrainer removed by vacuum. The batch was then cooled to room temperature. 140 parts of the above polymer were added to 35 parts of an 80:20 mixture of 2,4- and 2,6-toluene diisocyanate in a suitable reaction vessel, blanketed with an inert gas purge and then heated with slow stirring to 160 F. for 2 hours before cooling. Emulsification was the same as in Example VII and sheet preparation the same as in Example V. After 880,000 flexes on a Newark Leather Finish Co. flex tester, the sheet showed no sign of failure.
• This prepolymer (60 parts) and the triol prepolymer of Example VIII (10 parts) were emulsified as in Example VII and a sheet was made as in Example V. After 1,215,000 flexes on a Newark Leather Finish Co. flex tester the sheet showed no signs of failure.
• EXAMPLE XII gm. of a hydroxy terminated polybutadiene containing 0.1 hydroxyl equivalents were mixed with 18 parts of an 80:20 mixture of 2,4- and 2,6-toluene diisocyanate and placed in a bottle which was purged and sealed for 24 hours.
• Emulsification was carried out as in Example VII using a mixture of 60 gm. of the polybutadiene prepolymer and 10 gm. of the triol prepolymer of Example VIII.
• a sheet was formed as in Example V. After 1,215,000 flexes on a Newark Leather Finish Co. flex tester, the sheet showed no sign of failure.
• EXAMPLE XIII Into a suitable reaction vessel were placed 2,400 parts of polytetramethylene ether glycol (molecular weight 1,060), and 960 parts substantially water free toluene, 288 parts of toluene were distilled to render the charge substantially water free. The batch was cooled to 73 C. and 591.4 parts of an 80:20 mixture of 2,4- and 2,6- toluene diisocyanate were added. The temperature dropped to 68 C. and subsequently rose to 96 C. When the temperature dropped back to 90 C. it was held there for minutes before cooling. Emulsification was carried out as in Example VII and a sheet formed as in Example V.
• EXAMPLE XIV Into the 2 liter resin flask were placed 250 ml. of water, 5 gm. sodium alkyl arylsulfonate and 0.9 gm. of hydrazine hydrate. 60 gm. of the prepolymer of Example XIII were added as in Example XIII. An unstable emulsion resulted which was useful for about 8 hours if shaken gently from time to time. Sheet preparation was the same as in Example V. Use of a sodium alkyl arylsulfonate dispersing agent instead of potassium oleate produced a sheet having better physical properties.
• EXAMPLE XV 70 gm. of the diol prepolymer described in Example IX were mixed with 4 gm. of oleic acid. Chain extension and particle formation were carried out as in Example IV. A dispersion of moderately fine particles resulted which tended to form agglomerates which could be broken down again by placing on the Waring Blendor for 1 mmute with enough water to fill half the cup. Sheet formulation was the same as in Example IV. Sheet properties are given in Table III. Sheet properties (Table IV) were also obtained after air drying and after heating in an oven at 230 F. and at 280 F.
• EXAMPLE XVI Into a 1 liter 3-neck round bottom flask were charged 500 gm. of dihydric polyoxyethylene-polyoxypropylene, of molecular weight 1148, and 320 gm. of toluene. gm. of the toluene were distilled off to remove traces of water. The charge was cooled to 98 C. and 151.7 gm. of an 80:20 mixture of 2,4- and 2,6-toluene diisocyanate were added. The charge was heated to 120 C. for 3 hours and then cooled to room temperature. 250 gm. of the above prepolymer solution '(220 gm. of prepolymer) was placed in a Waring Blendor. To this were added 30.8 gm. of toluene and 12 gm. of an emulsifier consisting of a 14 in Example I. Sheet properties are given in Table III (Example XVII, (B-1)).
• Example II Another sheet was prepared as in Example I except that a blend of two parts of this material and one part of the latex of Example I was used. See Table III for properties (Example XVII, (B-2)).
• Drie atroom temperature 29 23 140 was formed using these particles following the procedure (b) aheated forlhour at wool no 50 11 0 of Example IV. (0) aheated for 1 hour at220 F.
• This material was substituted for the latex of Example I and a sheet was prepared.
• the sheet was very thick and had a low tensile strength believed to be caused by the excessively large size of the polyurethane particles.
• Example XV The sample was blended with an equal amount of the latex of Example I and used to prepare a leather sheet as Example XV:
• EXAMPLE XIX 30 lbs. of leather fibers (Lorum Y020 0l5) and 116 gal. water were lightly beaten in a Valley beater and were pumped into a 1,500 gal. tank along with 604 gal. water. 136 gm. of Na salt of a sulfonated naphthalene formaldehyde condensation product (Rohm & Haas Tamol SN), and lbs. of the latex of Example I (5 0% solids) were added. 2 lbs. alum (solids) were added as a 5% solution to coagulate the latex. The pH of the mixture was 5.1. 3 lbs. of Na CO were added to raise the pH value to 8.2. 15 lbs.
• nylon 0A", 1.5 denier were dispersed in 116 gal. water with 2 gal. of 1% deaeetylated karaya gum in at Valley beater. The dispersion was blended into the mixture in the tank. This mixture was fed into the headbox of a 27" wide Fourdrinier paper machine and formed into a sheet 60 mils thick and dried in the conventional manner over heated drums at temperatures of 95-l25 C. The sheet had a basis weight of 623 lbs. per 3,000 ft. a tensile strength of 120 lbs. per inch width in the machine direction and 58 lbs. per inch width in the cross direction, percent stretch at rupture of 30% in the machine direction and 60% cross direction, a Gurley densometer reading of 22 sees. for 400 cc.
• EXAMPLE XX A sheet made using the same proportions of ingredients and generally following the same procedures as set forth in Example XIX, had a caliper of .042" when dry.
• the dry sheet had a Gurley porosity of 36 sees. for 400 cc., a tensile strength of 63 lbs. per inch width and an elongation at rupture of 34%.
• the sheet after soaking in water had a tensile strength of 19 lbs. per inch width and an elongation of 25%.
• a portion of the sheet was heated at 150 C. for 10 minutes.
• the heated sheet had a caliper of .041", a Gurley porosity reading of 38 secs., a dry tensile strength of 75 lbs.
• An air permeable flexible water-laid sheet having at least one ply comprising between about 50 and 80 weight percent of elastomeric polyurethane in the form of globular floc particles having an average diameter between about 1 and 100 microns and between 20 to 50 weight percent of fibrous material, at least one-third of said fibrous material being leather fibers and the remainder being substantially staple fibers, at least 10 weight percent of said ply being leather fibers and at least 10 weight percent of said ply being staple fibers, said sheet having a dry porosity value as measured by a Gurley densometer of to 2,000 seconds per 400 cc. air per 60 mil thickness.
• a porous, breathable, flexible, water-laid sheet comprising betwen about 50 to 80 weight percent elastomeric polyurethane globules, at least some of which are present as agglomerates, and about 20 to 50 percent fibrous material, at least one-third of said fibrous material being tanned leather fibe-rs and substantially the remainder being staple fibers, at least percent of the dry weight of said sheet being leather fibers, said globules having an average diameter of about 1 to 100 microns.
• elastomeric polyurethane globules comprise the reaction product of an organic diisocyanate and a polyalkylene ether polyol chain-extended with an organic polyamine to an average molecular weight of at least 10,000.
• polyurethane globules comprise the reaction product of an aromatic diisocyanate and a polyoxyalkylene glycol chain extended with piperazine.
• a flexible water-laid sheet comprising between about 50 to 80 Weight percent elastomeric polyurethane in the form of globular floc particles having an average diameter between about 1 and 100 microns and about 20 to 16 50 weight percent of fibrous material, at least one-third of said fibrous material being leather fibers and the remainder being staple fiber, at least 10 percent by weight of the solid matter in said sheet being tanned leather fibers.
• An aqueous slurry suitable for preparing a leatherlike water-laid sheet comprising water and slurried solids having a papermaking consistency, said slurried solids comprising between 50 and percent globular particles of elastomeric polyurethane having an average particle size between 1 and microns and between 20 and 50 weight percent of fibrous material, at least one-third of said fibrous material being tanned leather fibers and essentially the remainder being high strength, flexible staple fibers, at least 10 percent of said solids being tanned leather fibers, so that when a sheet is formed by depositing said aqueous slurry on a foraminous surface said sheet when dried without pressure will have a porostiy value as determined on a Gurley densometer of 5 to 2000 seconds per 400 cc. of air per 60 mil sample thickness.
• a method for forming a porous breathable leather- -like sheet which comprises (a) depositing the slurry of claim 6 onto a foraminous surface to form a water-laid sheet (b) drying said sheet (0) heating said sheet at an elevated temperature of at least C. for a time sulficient to cause flow of said polyurethane particles without degrading said fibers, to form a tough, flexible, leatherlike sheet having improved tensile strength over that resulting after step (b).
• a method for forming a porous breathable leatherlike sheet comprising (a) providing a slurry defined by claim 6, (b) depositing said slurry on a foraminous surface to form a water-laid sheet, (c) drying said sheet, and (d) heating said sheet without pressure at an elevated temperature of at least about 120 C. for a time suflicient to cause flow of said polyurethane particles, (e) discontinuing said heating prior to flowing together of said polyurethane particles into a continuous phase, whereby a sheet having increased tensile strength over that resulting after step (c) is produced.
• a sheet according to claim 1 formed from at least two plies laminated to each other.
• staple fibers are wholly synthetic high tensile strength, flexible fibers selected from the group consisting of nylon, polyethylene te-rephthalate, and polypropylene.

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• 1965
  • 1965-09-16 US US487890A patent/US3436303A/en not_active Expired - Lifetime
• 1966
  • 1966-09-05 ES ES0330905A patent/ES330905A1/es not_active Expired
  • 1966-09-08 CH CH1299466A patent/CH527245A/de not_active IP Right Cessation
  • 1966-09-15 AT AT872366A patent/AT290849B/de not_active IP Right Cessation
  • 1966-09-15 BR BR182874/66A patent/BR6682874D0/pt unknown
  • 1966-09-15 SE SE12429/66A patent/SE316143B/xx unknown
  • 1966-09-15 GB GB41339/66A patent/GB1171132A/en not_active Expired
  • 1966-09-15 DK DK477766AA patent/DK126598B/da unknown
  • 1966-09-15 CS CS5995A patent/CS160083B2/cs unknown
  • 1966-09-15 DE DE1635546A patent/DE1635546C3/de not_active Expired
  • 1966-09-15 FR FR76246A patent/FR1501816A/fr not_active Expired

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