摘要:
This invention relates to isocyanate-terminated prepolymers, a process for the preparation of these isocyanate-terminated prepolymers, a process for the production of polyurethane.backslash.polyurea elastomers prepared from a diisocyanate comprising these prepolymers, and the elastomers produced by this process. These isocyanate-terminated prepolymers have a viscosity less than about 6000 mPa.cndot.s at 80.degree. C. and an NCO content of about 3 to 10%. These isocyanate-terminated prepolymers are the reaction product ofa) an aromatic diisocyanate,b) a polyether polyol having an OH number of about 25 to 125 and containing from about 1.8 to 2.5 hydroxyl groups, andc) an aliphatic diisocyanate.The equivalent ratio of the polyether polyol to the aromatic diisocyanate is from about 1.0:0.7 to 1.0:1.1.
摘要:
This invention relates to mixtures of polymethylene poly(phenylisocyanate) blends with epoxides. The addition of the epoxide stabilizes the reactivity of the polyisocyanate blends such that it is no longer dependent on the acidity. It is now possible to form polyurethanes from these mixtures based on polymethylene poly(phenylisocyanate) blends wherein less catalyst is necessary.
摘要:
Isocyanate prepolymers which are useful as binders are made from a polyisocyanate mixture and a hydroxyl compound having at least about 1 hydroxyl group. The polyisocyanate mixture is made up of from about 50 to about 60% by weight of polyphenyl polymethylene polyisocyanate and from about 40 to about 50% by weight of an isomeric mixture of diphenylmethane diisocyanate (MDI). The isomeric mixture of MDI is made up of from about 4 to about 30% by weight of the 2,4'-isomer and from about 70 to about 96% by weight of the 4,4'-isomer. The binders of the present invention are advantageous in that they may be used in high moisture, low temperature conditions without a catalyst. Reduced MDI emissions are also achieved when the binders of the present invention are used to make composite materials.
摘要:
The present invention relates to a novel photochromic polyurethane consisting essentially of an isocyanate reactive mixture consisting essentially of: i) from about 40 to about 85% by weight of one or more polyols having a nominal functionality of from 2 to 4 and molecular weights of from 500 to 6000 g/mole; ii) from about 15 to about 60% by weight of one or more diols or triols or mixtures thereof having a functionality of from 2 to 3 and molecular weights of from 62 to 499; b) an aliphatic polyisocyanate having a functionality ranging from about 2 to about 3; and c) a photochromic compound selected from a group consisting of spirooxazines, fulgides, fulgimides, and naphthopyrans, wherein the photochromic compound is present in an amount of 0.01 to 5 parts per hundred parts by weight of the isocyanate reactive mixture.
摘要:
The present invention relates to a novel photochromic polyurethane consisting essentially of an isocyanate reactive mixture consisting essentially of: i) from about 40 to about 85% by weight of one or more polyols having a nominal functionality of from 2 to 4 and molecular weights of from 500 to 6000 g/mole; ii) from about 15 to about 60% by weight of one or more diols or triols or mixtures thereof having a functionality of from 2 to 3 and molecular weights of from 62 to 499; b) an aliphatic polyisocyanate having a functionality ranging from about 2 to about 3; and c) a photochromic compound selected from a group consisting of spirooxazines, fulgides, fulgimides, and naphthopyrans, wherein the photochromic compound is present in an amount of 0.01 to 5 parts per hundred parts by weight of the isocyanate reactive mixture.
摘要:
This invention relates to novel light stable elastomers which exhibit good dynamic properties, and a process for their preparation. These elastomers comprise the reaction product of an isocyanate propolymer, a chain extender, and a catalyst selected from i) solid delayed action catalysts having a melting point of greater than about 60.degree. C., ii) alkyl substituted organotin catalysts containing alkylmercaptide ligands, and which are liquid at room temperature, and iii) alkyl substituted organotin catalysts containing sulfur bridging groups, and which are liquid at room temperature.
摘要:
This invention relates to a one-step process for preparing polyurea elastomers comprising reaction at an isocyanate index of from 90 to 200 of(a) one or more aliphatic and/or cycloaliphatic diisocyanates;(b) 25 to 70 equivalent percent, relative to the total of components (b) and (c), of one or more liquid amine-terminated polymers containing at least two aromatically bound isocyanate-reactive primary or secondary amino groups and/or aliphatically bound isocyanate-reactive secondary amino groups and having a molecular weight of from 400 to 6000; and(c) 75 to 30 equivalent percent, relative to the total of components (b) and (c), of one or more aromatic diamine chain extenders having a molecular weight of from 108 to 399, optionally in admixture with one or more crosslinkers.
摘要:
This invention relates to fire-resistant, flexible, molded, medium density polyurethane foams. These foams typically have a density of from 10 to 30 pcf. The foams are the reaction product of a) at least one polyester polyol, b) at least one highly branched polyether polyol, c) at least one chain extender, d) a polymethylene poly(phenyl isocyanate), an isocyanate group containing prepolymer based on a polymethylene poly(phenyl isocyanate), or mixtures thereof, e) a solid flame retardant and f) water. This invention also relates to a process for preparing these polyurethane foams in open molds.
摘要:
Fire-resistant, medium density molded polyurethane foams which may be removed from a mold in substantially shorter times than previously possible are produced by the process of the present invention. These reduced de-mold times are achieved by including a solid flame retardant composition in the polyurethane foam forming composition. This solid flame retardant composition includes a melamine coated ammonium polyphosphate and zinc borate.
摘要:
This invention relates to sprayable polyurethaneurea compositions, composite articles comprising at least one layer of these polyurethaneurea compositions and at least one layer of a polyurethaneurea foam forming composition, and to a process for the production of these composites.