Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/564—Polyureas, polyurethanes or other polymers having ureide or urethane links; Precondensation products forming them
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
  • C08L75/04—Polyurethanes
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/904—Artificial leather

Definitions

• An aspect of this invention relates to insole and outsole material for shoes, boots, and similar wearing apparel.
• Another aspect of this invention relates to a waterlaid sheet of leather fibers impregnated with a cured in situ elastomeric polyurethane (or polyurea) composition.
• Natural leather e.g., calfskin, steerhide, side leather, and similar epidermal or hide materials
• ease of fabrication good stitch tear and tongue tear resistance and easy shaping or lasting, good internal bond or strength (dry peel back resistance), and good wearing properties (resistance to compression set, abrasion resistance, flex fatigue resistance, etc.).
• the consuming public associates even the appearance, odor, and feel of leather with quality insole and outsole material and generally overlooks the disadvantages of leather, e.g., rapid water pickup (which may cause discomfort) and high density.
• a leather substitute to be preferable to natural leather in the high quality insole and outsole market, it would have to mimic the advantages and characteristics of leather while eliminating the disadvantages.
• the prior art approaches to making an artificial sole material have generally involved the use of a rubbery polymer alone or in combination with a fibrous filler or web, the fibrous material being either synthetic (e.g., nylon, polyester, etc.) or natural (wool, cotton, leather dust, cork, etc.).
• the resulting sole material generally has very specialized uses (e.g., tennis shoes, work shoes, and the like) due to the lack of leather-like characteristics.
• Void volume is particularly likely to be sacrificed when pressing and/or large amounts of'binder are used to achieve a good internal bond. Large amounts of saturant tend to fill up voids, and pressing reduces the number and/or size of the voids.
• a typical fiber/polymer sheet containing a substantial amount of leather fiber has a true density (density at 0 percent void volume) ofiat least 1.1 g/cc and generally greater than 1.2 g/cc. If a void volume of at least 20 percent could be achieved and maintained, the sheet could have an apparent density lower than 0.9 g/cc, a significant improvement over natural leather and many types of synthetic outsole materials. (However, the danger of more rapid water pickup must always be borne in mind.) But pressed sheets often have 20 percent voids.
• leather fiber has striking aesthetic and economic advantages for use as a filler or fibrous component in a shoe sole material; for this reason a leather-fiber/polymer sheet with low. apparent density, low compression set, slow water pickup, good internal strength, etc., is still being sought by industry.
• this invention contemplates providing a sheet material from natural leather fiber and a rubbery binder wherein: pressing or other densification of the sheet and the amount of rubbery binder in the sheet are kept to a minimum, thereby maintaining a high void volume; both desirable leather-like properties and the amount of leather fiber in the sheet are maximized, thereby taking full advantage of the aesthetic appeal and properties of leather; the rate of water pickup of the sheet is made as slow as possible, so that upon brief immersions in liquid water, only a minor amount of the voids will take up liquid water; the internal bond of the sheet is maximized; the permanent compression set of the sheet is minimized; and the method of making the sheet is designed such that strict control over all of the aforementioned properties is possible.
• This invention also contemplates a substantially uniform impregnation of awaterlaid sheet with a rubbery binder which can be non-linear and/or relatively high in molecular weight.
• this invention involves:
• the uncured impregnant can undergo an exothermic in situ cure in the waterlaid sheet at ambient temperatures, e.g., C. or higher.
• substantially all of the curing should be in situ, i.e., after impregnation, rather than during the mixing step, and the uncured impregnant should contain at least about 20 wt. percent solvent.
• removal of the solvent from the waterlaid sheet can be accomplished by drying at room temperature or, preferably, at suitable elevated temperatures. Solvent removal should not be begun until the in situ cure is substantially completed. Afterthe in situ cure of the impregnant is complete,
• the term denotes a paper-like sheet having a small thickness (relative to the area) and comprising solids which have been deposited from an aqueous slurry or the like onto a foraminous surface, e. g., onto the screen of a handsheet mold or Fourdrinier machine.
• leather-like sheet materials made according to this invention have a substantially uniform fiber/polymer ratio throughout their thickness.
• the thickness, for outsole materials or heels can be up to 2 or 3 cm or more; typically, 6 or 9 Iron (0.32 or 0.48 cm) sheets make good sole materials.
• Lamination can be used to increase the thickness still further, and splitting can be used to reduce the thickness to, for example, a millimeter.
• the process of this invention is inherently capable of producing, without lamination, sheets about 0.5 -l .0 cm in thickness.
• substantially uniform means'that, in the innermost regions or core areas of the impregnated and cured sheet produced by this invention (which will normally be 0.5-l cm thick), the fiber/polymer ratio is substantially the same as that of the areas or regions near (within a millimeter of) the exposed surfaces of the sheet, differences or variations in this ratio between such core and near-surface regions being substantially less than 20 percent and preferably less than 10 percent. (it may be desirable to have a higher fiber/polymer ratio at one or more surfaces of the sheet to provide a leather-like skin.)
• the apparent density of sheets made according to this invention can be less than 1.0 g/cc, and apparent densities as low as 0.3 g/cc have been achieved in practice.
• the apparent density should be well below 1.4 g/cc, and preferably below 1.2 g/cc.
• An internal bond strength (dry peel back) substantially greater than 10 pounds per lineal inch 1,800 g. per lineal cm) can be obtained according to the teachings of this invention.
• the theoretical void volume of sheets of this invention can be as high as 80 percent, but preferably is less than percent.
• the 'void volume should be at least 20 percent. Of the total apparent volume of a sheet made according to'this invention, about 15 to about 35 percent will be closed, or substantially closed, cells.
• the permanent compression set (ASTM test B-2213-cT) of the cured sheet is less than about 25 percent and is preferably less than 15 percent.
• the fiber/polymer ratio (by weight)-of the cured sheets ranges from 0.4:1 to 1.7:], preferably about 1:1, and the particular fiber-to-polymer ratio for a particular sheet will have the substantial uniformity described previously. (Expressed in terms of polymer-to-fiber ratio, this range is 0.6:l2.5:l, and preferably about 1:1.)
• the flex fatigue resistance or flex life of sheets of this invention is determined by cutting a hole in a sample sheet and flexing it on a Ross Rubber Flexing Machine (Emerson Apparatus Co., Melrose, Mass). Samples are conditioned at 50 percent relative humidi ty and 23 C. before the Ross flex test. The flex life of preferred sheets of this invention is in excess of 30,000 cycles.
• a particularly advantageous feature of cured sheets made according to this invention is the slow water pickup rate.
• the expression water pickup rate means the percent of water absorbed at room temperature by an initially dry sample in a given increment of time.
• the percent of water absorbed can be expressed as either weight percent (based on the weight of a dry sample) or volume percent (based on the apparent volume of a dry sample). For ease of calculation, all measurements are in grams and cubic centimeters, and the density of water at room temperature is assumed to be exactly one gram per cc. If W is the weight of the dry sample and W is the weight of the sample after immersion in a room temperature water bath, the weight percent water absorption will be given by:
• volume percent absorption is obtained by multiplying the above expression by the apparent density, assuming the density of water is 1.00 g/cc.
• At least one-third and preferably two-thirds, by weight, of the fiber used in practicing this invention should be leather fiber of paper-making length (less than about 15 mm and preferably less than 5 mm).
• the natural leather fibrous material can be chrome or vegetable tanned and can be dyed and/or pigmented.
• the leather fiber can be slurried with a discontinuous (e.g., chopped staple) synthetic fiber such as polyamide, regenerated cellulose or cellulose acetate (e.g., rayon), polyolefin (e.g., polyethylene or polypropylene), polyester (e.g., polyethylene terephthalate and acetal copolymers), etc.
• Naturally occurring staple fibers such as wool and cotton (or other natural cellulosic fibers) can also be used.
• Such natural or synthetic staple fiber is preferably one to six denier and preferably shorter than 15 mm. in length.
• the amount of natural or synthetic fiber other than leather should be kept to less than 10 wt. percent and preferably less than 5 wt. percent of-the total fiber content of the sheet.
• these lower synthetic fiber content materials have a slower water pickup rate.
• Elastomeric binder-forming materials used in the practice of this invention are not introduced into the sheet until after formation and drying of the fibrous waterlaid sheet is complete.
• the preferred binder material after curing, comprises a polyurethane (including polyurethane-polyurea) or'polyurea elastomer containing --NHRNHCO- and X-Z-X CO units, and preferably -XZ XCO units,
• aralkylene or aromatic group such as an alkylene radi-.
• cal of four to 10 carbon atoms or a monocyclic or polycyclic aromatic or aralkyl nucleus such as benzene, toluene, xylene, diphenylmethane, naphthalene, etc.;
• X is O, S, NH, N-aliphatic, or the like;
• Z is a polyoxyalkylene or polyester chain; and Z is a divalent aliphatic, cycloaliphatic, or aromatic radical. Although these units are shown as divalent structures, it should be understood that, if a crosslinked, crosslinkable, branched-chain polyurethane is desired, the Z, Z "or R groups can have one or more additional substituents.
• the Z radical is derived from a compound having the formula Z (XH),,,, wherein Z and X are as defined previously, m is 1-5, preferably 2 or 3, and H is an active hydrogen as defined previously; Z (XH), can be piperazine and the like.
• X is oxygen or NH. If the Z chains in the molecule are not the same, i.e., the polymer contains more than one kind of polyoxyalkylene and/or polyester chain, at least one 2 chain preferably has a molecular weight of at least about 400 but less than about 5 ,000.
• polyester units are preferably of the repeating formula OA O COA CO, wherein A and A are divalent aliphatic groups such as alkylene radicals.
• a and A are divalent aliphatic groups such as alkylene radicals.
• These polyester units can be derived from the interaction of a bifunctional initiator with one or more lactones, for example, as described in U.S. Pat. No. 2,933,477, or by an esterification or ester-interchange reaction involving a dicarboxylic acid or anhydride or ester thereof with an alkylene polyol, preferably an alkylene glycol.
• polyesters are prepared from dicarboxylic acids, anhydrides, or esters, and alkylene glycols, the
• preferred acid, anhydride, or ester can be selected from a wide variety of polybasic (preferably dibasic) acids. It is preferred to use the dibasic fatty acids, i.e.,
• dibasic acids are malonic, succinic, and adipic.
• useful alkylene glycols are ethylene glycol; 1,3-propane-diol; 1,4-butane diol, and the like.
• chain-extending, chain-branching, or chain-terminating agents e.g., arylene diamine chain extenders.
• chain-branching agents are the triols and triamines commonly used in the polyurethane art.
• Choain propagation can be carried out in any suitable manner know in the art, e.g., the one shot procedure, which generally involves the use of a catalyst, or the chain-extension of a suitable prepolymer. Prepolymers are preferred.
• the preferred components are: an aromatic diisocyanate, an active hydrogen component comprising a polyoxyalkylene glycol and an aromatic diamine, and, optionally, one or more compounds having 3-5 active hydrogen-bearing substituents (e.g., a triol), and a suitable catalyst, e.g., an organo-metallic compound such as stannous octoate, mercuric acetate, phenyl mercuric acetate, or the like.
• a suitable catalyst e.g., an organo-metallic compound such as stannous octoate, mercuric acetate, phenyl mercuric acetate, or the like.
• Polyoxyalkylene diamines can be substituted for the polyoxyalkylene glycol with good results. An advantage of this substitution is that the resulting polyurea can be more degradation resistant. Water and/or carboxyl containing compounds can be included in the active hydrogen component, but due to the formation of carbon dioxide, such inclusion is ordinarily
• the molecular weight, cross-link density (if any), amount of aromatic content (if any), amount of urea and/or urethane linkages, etc., of the polyurethane or polyurea binder material must be selected such that the binder is elastomeric in nature.
• elastomeric is meant the ability of an article, e.g., a cast film consisting of the polymer, to be elongated substantially more than percent of its length and to return with force to substantially the original length.
• Elastomeric polymers suitable for use in this invention have a molecular weight greater than 10,000 and form films with the following physical properties: (tested free of fillers and the like at 23 C.
• the stress at 100 percent elongation should not exceed 1,000 psi (70 Kg/cm).
• the elongation at break should not exceed 1,500 percent.
• the elastomeric binder materials of this invention are preferably formed by mixing the starting materials in the presence of a volatile organic liquid solvent or vehicle (i.e., a solvent for the uncured starting materials, not necessarily the fully cured polymer) and a suitable catalyst to form a low viscosity saturant system with which the waterlaid sheet is saturated.
• a volatile organic liquid solvent or vehicle i.e., a solvent for the uncured starting materials, not necessarily the fully cured polymer
• a suitable catalyst to form a low viscosity saturant system with which the waterlaid sheet is saturated.
• the starting materials interact primarily while in situ, i.e., in the sheet.
• a suitable catalyst is'included in the saturant mixture
• curing of the mixture can be completed at ambient temperatures near roomtemperature, e. g., 20-25 C. Since the curing reaction-is exothermic, the use of ordinary ambient temperatures is preferred; however, ambient tem'- peratures up to 65 C
• Suitable solvents include esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran and dioxane, ketones such as acetone and methylisobutylketone (but, with ketones, Schiffs base reactions must be considered), sulfones, hydrocarbons (particularly aromatic hydrocarbons such as toluene) sulfoxides, chlorinated hydrocarbons, and mixtures of one or more of these.
• Organic liquids can, if desired, be selected from the-above list with a view toward low toxicity and/or miscibility with water.
• the organic liquid solvent can be evaporated or drawn off from the cured, impregnated sheet at ambient temperatures near room temperature or at elevated temperatures, e.g., up to 70 C., and at atmospheric or subatmospheric pressure.
• the aromatic hydrocarbons (benzene, toluene, xylene,
• a waterlaid sheet of fiber Prior to impregnation with the elastomeric binderforrning impregnant, a waterlaid sheet of fiber is made according to standard papermaking techniques using a Fourdrinier screenor a hand sheet mold. This waterlaid sheet is substantially self-supporting and has sufficient strength after drying to pennit further processing.
• the sheet is saturated with the impregnant by any suitable method including immersion in, floating upon, or spraying with the impregnant.
• the preferred method (hereinafter referred to as float saturation) is to float the sheet upon a bath of the impregnating agent.
• the starting materials which make up the impregnant are preferably premixed prior to the impregnation step.
• the time lapse between mixing up the impregnant and commencing the saturation of the waterlaid sheet should not be unduly long, however. With some systems, a lapse of up to 2 hours is not too detrimental, but the lapse should preferably be as short as possible, e.g., less than minutes, preferably less than 5 minutes.
• the time lapse can be reduced to zero by spraying the waterlaid sheet with two sprayheads, one dispensing an active hydrogen-containing component and the other dispensing the free isocyanate component. The two sprays intermingle in the interstices of the sheet, thus combining the impregnating and mixing steps of this invention.
• a dyed pigmented leather fiber sheet was prepared as follows: Chrome tanned leather fibers (Lorum Fiber Co. Y-020-015 chrome tanned leather fibers) were beat up with water using a Vally paper beater (Vally Iron Works). A 6.3 wt. percent total solids leather fiber slurry was obtained having an S.R. (Schopper-Riegler) freeness of l9.5. One hundred thirty-eight grams of leather solids (2,190 grams of slurry) was diluted to liters in a S-gallon 17.9 liters) pail with cold tap water. The diluted slurry was added to a 12 X 12 inch (30.5 X 30.5 cm) Williams Apparatus Co. handsheet mold. The slurry was drained catching the fibers on the wire. The resulting waterlaid sheet was then removed and dried in a 150 F. (66 C.) forced air oven.
• the two-part polyurethane impregnant system was as follows:
• Part -A Two hundred parts of a Part -A (composed of 712 parts of a 2,000 molecular weight polyoxypropylene glycol, 43.2 parts of methylenebisorthochloroaniline, 4.3 parts phenylmercuric acetate, 32.0 parts of an amorphous silica filler with particle size of approximately 0.1 micron (available under the trademark Cab-O-Sil from Cabot Corp.), 3.0 parts of a mull of 80% PbO,(by wt.) in a 2,000 molecular weight polyoxypropylene glycol, 2.40 parts of calcium octoate and 3.2 parts of 2,6-ditertiary butyl paracresol), and
• Part B prepolymer Sixty parts of a Part B prepolymer (composed of 30.6 parts of a 400 molecular weight polyoxypropylene diol and 8.7 parts of a 435 molecular weight polyoxypropylene triol reacted with 60.7 parts of /20 [by wt.] isomer mixture of 2,4l/2,-toluenediisocyanate at 66 C. for approximately 4 hours).
• Parts A" and B were mixed with 482 parts toluene and poured into a 8% X 12 inch (21.5 X 30.5 cm) glass tray immediately after mixing. Within a minute after this pouring step, a 6 X 12 inch (15.25X 30.5 cm) piece of the above described dried, waterlaid sheet of leather fiber was submerged in this bath and saturated. After about an hour an immobile gel formed. The impregnated sheet was removed, the excess polymer scraped from its surface, followed by drying at F. (66 C.). The dried sheet looked very much like leather.
• the finished sheet had the following properties:
• Each waterlaid sheet was rubber dammed by placing a thin sheet of latex film over the still-wet waterlaid sheets and removing the air from below so as to further remove water.
• the sheets were dried at 200 F. (93 C.) for 8 hours.
• the dried waterlaid sheets were all approximately 0.4 inch (1.0 cm) thick, having an apparent density of approximately 0.3 g/cm.
• the saturant was: 158 parts of a Part A (composed of 3,560 parts of a 2,000 average molecular weight polyoxypropylene glycol and 216 parts methylenebisorthochloroaniline) mixed with 50.4 parts of the same Part B described in Example 1, 388 parts toluene, and 3.12 parts of a 30 wt. percent solution, in aqueous ammonia, of phenylmercuric acetate catalyst (Metasol 30, trademark of Metal Salts Corp., l-lawthrone, N.J.).
• Example 2(8) 45 wt. percent Solids Saturant Another sheet was prepared by the procedure of Example 2(A) and with the same materials except that the following saturant formulation was used:
• Example 2(C) 55 wt. percent Solids Saturant Another sheet was prepared using the same procedure and materials as in Example 2(A) except the following saturant formulation was used:
• Example 2(A) 250 parts of Part A 80 parts of Part 8" 270 parts of toluene 1.82 parts of the catalyst solution of Example 2(A)
• Example 2(D) 65 wt. percent Solids Saturant
• Example 2(E) 70 wt. percent Solids Saturant
• EXAMPLE 3 In this example, up to 50 percent by weight of the A dry waterlaid sheet was prepared from dyed, pig-.
• Example 3 wt. percent leather/25 wt.
• Example 3(A) 50 wt. percent leather/50 wt. percent Rayon A dyed, pigmented 50 percent leather/50 percent rayon fiber dry waterlaid sheet was prepared by the same process as in Example 2 except that 50 percent of the leather was replaced with one-quarter inch (0.63 cm) long by 2 denier rayon fibers. This sheet was then float saturated, pressed and dried as in Examples 3(A) and 3(8).
• EXAMPLE 4 This example illustrates the uniformity of the polymer-to-fiber ratio throughout the impregnated waterlaid sheet.
• a dry waterlaid sheet was prepared from dyed, pigmented leather fiber as in Example 2.
• An 8 X 12 inch (20.3 X 30.4 cm) piece of this dry sheet was float saturated and dried at 66 C. as described in Example 1.
• Example 2(A) 153.2 parts of the Part A described in Example 2 46.8 parts of the Part B described in Example 2 200 parts of toluene 1.45 parts 30 wt. solution of phenylmercuric acetate (see Example 2(A)
• the resultant sheet was then split into 1 1 layers, each as near as possible to 30 mils (0.076 cm) thick, numbered l-l 1 from top to bottom.
• EXAMPLE 5 orthochloroaniline, both of which are dissolved in toluene at 55.5 percent solids was mixed with 243.9 parts of a Part B (a prepolymer prepared by reacting 1,000 parts of a 1,000 molecular weight, hydroxyl terminated poly(epsilon-caprolactone) with 348 parts 80/20 mixture 2,4-/2,6-isomers of toluene diisocyanate in toluene at 52.9 percent solids for 4 hours at C 27.6 parts of toluene and 0.75 g. of a 30 wt.
• Part B a prepolymer prepared by reacting 1,000 parts of a 1,000 molecular weight, hydroxyl terminated poly(epsilon-caprolactone) with 348 parts 80/20 mixture 2,4-/2,6-isomers of toluene diisocyanate in toluene at 52.9 percent solids for 4 hours at C 27.6 parts of toluene and 0.75 g. of
• Example 2(A) An 8 X 8 inch (20.3 X 20.3 cm.) piece of the abovedescribed waterlaid sheet was float saturated as described in Example 1. The excess gel was removed followed by drying at 150 F. (66 C. as in Example 1.
• EXAMPLE 6 A leather fiber waterlaid sheet was prepared by the same procedure as in Example 2 except that enough crimped one-quarter inch (0.64 cm) X 2 denier nylon fibers were added to fiber slurry to equal 3 percent of the total leather fiber weight. The following saturant formulation was used:
• the resultant sheet had the following properties:
• EXAMPLE 7 A polyether urea Part B was prepared diluting 1,000 parts of a 2,000 molecular weight polyoxypropylene diamine with 1,000 parts of toluene. One hundred seventy-four parts of (/20 [wt.] mixture 2,4-/2,6-isomers) toluene diisocyanate was diluted with 174 parts toluene also. The polyether diamine solution was then added to the toluene diisocyanate solution with agitation. The mixture was allowed to exotherm and then cool to room temperature.
• Part A was prepared by dissolving parts of methylene-bis-orthochloroaniline in 200 parts of dimethylformamide.
• elastomeric binders containing polyoxypropylene chains have the advantage of providing a relatively flexible impregnated and cured sheet wherein the leather content has somehow been made at least partially hydrophobic. Similar advantages, at slightly greater cost, can be obtained with other polyoxyalkylene (Z chains wherein the alkylene portion of the oxyalkylene units contains at least three carbon atoms, e.g., poly(oxy-l,2-butylene), poly(oxy-l ,4-butylene), etc. Oxyethylene units are not preferred, due to their relatively high hydrophilicity.
• a process for preparing an impregnated fibrous sheet comprising:
• a curable liquid impregnant system comprising a. a polyisocyanate

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
• Laminated Bodies (AREA)
• Polyurethanes Or Polyureas (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22149783

Family Applications (1)

Country Status (5)

Cited By (20)

Citations (12)

• 1970
  • 1970-10-08 US US00079318A patent/US3708333A/en not_active Expired - Lifetime
• 1971
  • 1971-10-07 CA CA124,717A patent/CA955812A/en not_active Expired
  • 1971-10-07 GB GB4682171A patent/GB1363708A/en not_active Expired
  • 1971-10-07 DE DE19712150556 patent/DE2150556A1/de active Pending
  • 1971-10-07 FR FR7136109A patent/FR2110296B1/fr not_active Expired

Patent Citations (12)

Also Published As

Similar Documents