摘要:
Polymers having substituted urea groups, and molded objects therefrom, can be made by reacting, in a reaction injection molding (RIM) process, a composition comprising (A) a polyisocyanate and (B) a mixture comprising an imino functional resin and a chain extender. The chain extender may also be imino functional.
摘要:
An internal mould release composition, suitable for use in the production of moulded articles by the RIM process comprising :
a) a metal salt of an organic acid, said metal salt having mould release properties, and b) a polymer having a molecular weight of at least 1500 containing at least two guanidine or isourea groups of the formula : wherein A represents and wherein each of Q¹ and Q², independently, represents hydrogen, alkyl or cycloalkyl and each of Q³ and Q⁴, independently, represents hydrogen, alkyl, cycloalkyl, arakyl or aryl.
摘要:
A polyisocyanate composition, suitable for use in the production of elastomers by the RIM process, said composition being the product of reacting an alcohol and/or thiol having an average hydroxyl and/or thiol functionality of from about 1.5 to about 4 and an average hydroxyl and/or thiol equivalent weight of at least 500 with at least 2 equivalents, per hydroxyl and/or thiol equivalent, of an organic polyisocyanate under such conditions that at least about 20 % of the initially formed urethane and/or thiourethane groups are converted to allophanate and/or thioallophanate groups.
摘要:
An isocyanate-reactive composition having a plurality of isocyanate-reactive groups comprising :
(i) at least one polyol having a number average molecular weight of from 2000 to 12,000; (ii) at least one low molecular weight polyol, including water, immiscible in said high molecular weight compound and having a molecular weight in the range of 18-500; and (iii) a compatibilising amount of an amidine compound of the Formula (1)
wherein each of R¹ to R⁴ represent H or, independently or together, an organic radical selected from :
(a) alkyl radicals having 1 to 25 carbon atoms; (b) cyclo alkyl radicals having 5 to 25 carbon atoms; (c) aralkyl and/or aryl radicals having 6 to 18 carbon atoms, and (d) polymeric chains containing hetero atoms selcted from polyether, polythioether, polyester, polycarbonate and polyacetal chains.
The amidine improves the stability of compositions comprising high and low molecular weight polyols.
摘要:
The invention relates to polyisocyanate compositions comprising compounds of the general formula T m (R) n wherein T represents a chain of more than 70 atoms, m represents an integer of at least 1, R represents an isocyanate group containing residue and n is an integer of at least 2, at least one of the residues represented by R containing at least two isocyanate groups separated one from another by a chain of from 5 to 30 atoms and the sum of the residues represented by R constituting less than 50 % of the total molecule on a weight basis. The invention also relates to a method for the preparation of flexible polymeric foams using such polyisocyanate compositions.
摘要:
A polyurea elastomer comprising the reaction product of an organic polyisocyanate, an aromatic amine-terminated chain extender, an isocyanate-reactive amine having a molecular weight of at least 200 and at least two isocyanate-reactive groups at least 50 % of which are aliphatically bound primary and/or secondary amino groups and an aldehyde or ketone in an amount equivalent to at least 5 % of the aliphatic amino group content of the isocyanate-reactive amine.
摘要:
Improved reinforced polyurethane/urea articles are made by reacting an organic polyisocyanate with low viscosity imino/enaminefunctional compounds in contact with fiberous reinforcing agents.
摘要:
Polyurethane/polyurea foams are made by reacting an organic polyisocyanate with resins containing imino/enamino-functional groups in the presence of blowing agents. Control of foam properties is offered by selecting imino/enamino-functional groups which decompose with water at the temperature of the reaction to produce volatile gases.