| 摘要 |
Polyurethanes and compositions used in nonwoven fabrics (see Division D1) are: (Example 1) polyurethane derived from polyethylene-propylene adipate having hydroxyl groups at both ends, p,p1-diphenylmethane diisocyanate and ethylene glycol is dissolved in dimethylformamide; (Example 2) polyurethane derived from poly-epsilon-caprolactone, having hydroxyl groups at both ends, p,p1-diphenylmethane diisocyanate and ethylene glycol is dissolved in tetra-hydrofurane; (Example 3) a prepolymer having isocyanate groups at both ends and derived from polytetramethylene glycol, p,p1-di-phenylmethane diisocyanate and p,p1-methylene-dianiline is dissolved in dimethylformamide; (Example 4) ethyl-cellulose-octadecylurethane is added to the solution of Example 1; (Example 5) sorbitan monopalmitate is added to the solution of Example 2; (Example 6) the solution of Example 3 is diluted with dimethylformamide and ethylcellulose-octadecylurethane is added; (Example 7) polyurethane derived from polyethylene adipate, diethylmethane diisocyanate and 1,4-butandiol and sorbitan monostearate are dissolved in dimethylformamide; another solution has the same composition but contains also stearyl alcohol; and (Example 8) a polyurethane formed from the same monomers as in Example 1, but in different proportions, is dissolved in dimethylformamide and mixed with sorbitan monostearate. ALSO: Sheet material resembling leather is made by applying to the fibres of a fibrous base material a bonding inhibitor, simultaneously or subsequently applying a solution of an elastomeric polymer to the base material, solidifying the elastomeric polymer and dissolving out at least a portion of the bonding inhibitor with a suitable solvent. The bonding inhibitor contains an alkyl group of from 4 to 50 carbon atoms and is a hydrocarbon, a salt or ester of a carboxylic acid, an amide, an alcohol, a nitrile, a halide, an amine, a sulphonate, a ureide or a urethane derivative, including mixtures such as paraffin wax or chlorinated paraffin. It inhibits bonding between the polymer and the fibres. In the Examples: (1) a blended spun fibre of nylon-polystyrene is stretched, crimped, cut to staple length, and made into a random web; this web is needle-punched, dipped in an aqueous dispersion of ethylcellulose-octadecylurethane and dried; it is then dipped in a solution of a polyurethane elastomer in dimethylformamide, then in aqueous dimethyl formamide to solidify the elastomer, squeezed, washed with water and dried; the sheet is then steeped in hot toluene to extract the p ethylcellulose-octadecylurethane and part of the polystyrene in the fibres, washed with methanol and dried; (2) a mat of crimped nylon staple fibres is dipped into an emulsion of paraffin wax, squeezed, dried, impregnated with a solution of a polyurethane elastomer in tetrahydrofurane, dipped into aqueous tetrahydrofurane and then water to solidify the elastomer, washed with water, dried, extracted with hot toluene, washed with methanol and dried; (3) a mat of crimped polyvinyl alcohol fibres is dipped into a solution of stearyl alcohol in methanol, squeezed, dried, impregnated with a solution of a polyurethane prepolymer in dimethylformamide, then into aqueous dimethylformamide and then water, squeezed, washed and dried, steeped in hot methanol, washed and dried; (4) stretched and crimped nylon-polystyrene blended spun fibre is cut to staple length and polyvinyl chloride fibre is added; a random web is formed, needle-punched, shrunk by treatment with hot water and then hot air, impregnated with a solution of a polyurethane and ethylcellulose-octadecylurethane, in dimethylformamide, dipped into aqueous dimethylformamide, squeezed, washed with water and pressed between hot rollers to smooth and dry it; it is then steeped in hot toluene, washed with methanol and dried; (5) a non-woven mat of crimped nylon staple yarn is impregnated with a solution of a polyurethane elastomer and sorbitan monopalmitate in tetrahydrofurane, dipped into aqueous tetrahydrofurane and then into water, squeezed, washed with water, pressed and dried, extracted with hot toluene, washed and dried; (6) a non-woven mat of crimped polyvinyl alcohol fibres is dipped into a solution of stearyl alcohol in methanol, squeezed and dried, impregnated with a solution of a polyurethane prepolymer and ethylcellulose-octadecylurethane in dimethylformamide, dipped into aqueous dimethylformamide and then in to water, squeezed, washed with water, pressed and dried, steeped in hot methanol, washed with water and dried; (7) a non-woven mat of the same fibres as in Example 1 is impregnated with a solution of a polyurethane elastomer and sorbitan monostearate in dimethylformamide, passed between rollers to compress and smooth it, coated with a solution of the same composition as the impregnant but containing also stearyl alcohol, dipped into aqueous dimethylformamide then into cold and then warm water, squeezed between rollers in warm water, dried and squeezed between rollers in hot toluene; (8) a non-woven mat of the same fibres as in Example 1 is dipped into toluene to extract the polystyrene from the fibres, treated with an emulsion of ethylcelluloseoctadecylurethane as in Example 1 and dried, impregnated with a solution of a polyurethane elastomer and sorbitan monostearate in dimethylformamide, dipped into aqueous dimethylformamide, worked by roller press, washed with water, dried, extracted with toluene, and washed with methanol. Reference is also made to the use as elastomer of polyacrylates, polyolefine derivatives, chlorinated polyethylene and synthetic rubber. The sheet materials may have their surfaces decorated by colouring, lustring or smoothing, by dyeing spraying, or coating a finish of dissolved or emulsified polymer, pattern printing or embossing. |
