摘要:
Urethane-modified polyisocyanates having an NCO-content of from 5 to 45 wt. % are made by reacting an organic polyisocyanate or mixture of polyisocyanates having an NCO-content of from 30 to 50 wt. % with an organic polyhydroxyl compound or mixtures of polyhydroxyl compounds. The organic polyhydroxyl compound must include at least 10 hydroxyl equivalent percent of an alkoxylation product of a bisphenol corresponding to a specified formula containing two alcoholic hydroxyl groups and having an OH number of from 112 to 389. The reactants are employed in quantities such that the NCO:OH equivalent ratio is from 2:1 to 50:1. The urethane-modified polyisocyanates of the present invention are particularly useful in the production of polyurethanes by the isocyanate polyaddition process.
摘要:
The present invention is directed to a process for the production of urea- and/or biuret-modified polyisocyanates by reacting organic polyisocyanates with a mixture of high molecular weight isocyanate-reactive compounds and low molecular weight isocyanate-reactive compounds, wherein at least 25% of the isocyanate-reactive groups are primary amino groups. The present invention is further directed to the products obtained by this process and their use for the production of polyisocyanate polyaddition products, especially for the preparation of molded articles by the RIM process.
摘要:
Optionally-foamed polyurethanes are produced by reacting polyisocyanates with organic compounds containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range from 400 to 10,000, in the presence of activators corresponding to the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and represent C.sub.1 -C.sub.20 -alkyl, C.sub.5 -C.sub.7 -cycloalkyl, C.sub.6 -C.sub.14 -aryl or C.sub.7 -C.sub.30 -alkaryl,X.sup.1 and X.sup.2 may be the same or different and represent halogen or a radical of the formula --OR.sup.5, --SR.sup.6 or ##STR2## with the proviso that X.sup.1 and X.sup.2 cannot both represent a halogen atom,R.sup.5, R.sup.6 and R.sup.7 may be the same or different and represent a C.sub.1 -C.sub.20 -alkyl, C.sub.5 -C.sub.7 -cycloalkyl, C.sub.6 -C.sub.14 -aryl or C.sub.7 -C.sub.30 -alkaryl and 1.ltoreq.x.ltoreq.4,and, optionally, in the presence of co-catalysts, blowing agents, chain-extending agents having a molecular weight of from 32 to 400 and other known auxiliaries and additives.
摘要:
The present invention relates to a process for the production of polyisocyanate compositions containing urethane groups and having an isocyanate content of about 0.5 to 45% by weight by the reaction of(a) an organic polyisocyanate or mixtures thereof having an isocyanate content of about 30 to 50% by weight with(b) organic polyhydroxyl compounds using an equivalent ratio of isocyanate groups to hydroxyl groups of at least 1.8:1, characterized in that the polyhydroxyl compounds (b) are based on(b1) polyhydroxypolyacrylates having an average molecular weight, determined by vapor pressure osmometry, of 232 to about 100,000 which optionally contain urethane or ester groups in side chains, and a statistical average of at least one alcoholic hydroxyl group per molecule(b2) optionally in admixture with up to about 250% by weight, based on (b1), of other polyhydroxyl compounds in the molecular weight range of 62 to about 12,000.The invention also relates to the polyisocyanate compositions obtainable by this process and their use as components for the production of polyurethanes or polyurethane ureas.
摘要:
Homogeneous storable mixtures containing small quantities of salts and having a high mixed hydroxyl number of mixed hydroxyl/amine number are made by mixing (a) a polyoxyalkylene polyol and/or polyolamine and/or polyamine based on an alkyloxirane having a molecular weight of from 400 to 12,000, (b) a low molecular weight polyol which is not completely miscible with (a) and a solution-promoting additive in quantities such that for every 100 parts of (a), from 1 to 200 parts of (b) and from 0.01 to 10 parts of (c) are present. The solution-promoting additives are salts of cations of Groups IA, IIA and IIIA of the Periodic System of Elements or ammonium or mono- to tetra-alkylammonium ions and anions formed by removing at least one proton from an acid having a K.sub.s -value of at least 10.sup.-7. These mixtures are particularly useful in the production of polyurethanes.
摘要:
The present invention is directed to a process for the production of polyisocyanates containing urea and/or biuret groups by reacting organic polyisocyanates with a mixture of water, high molecular weight isocyanate reactive compounds and optionally low molecular weight isocyanate reactive compounds. The present invention is further directed to the products obtained by this process and their use for the production of polyisocyanate polyaddition productions, especially for the preparation of molded articles by the RIM process.
摘要:
A process for the production of optionally cellular molded articles with a smooth outer skin and improved surface characteristics by the reaction, inside a closed mold, of a mixture of one or more organic polyisocyanates, one or more compounds having molecular weights of from 400 to 12,000, which contain at least two isocyanate-reactive groups, chain-linking and/or chain-extending agents, and optionally, known auxiliary agents and additives used in polyurethane chemistry, characterized in that before the reaction, surface-improving additives comprising one or more polymers or copolymers of one or more olefinically-unsaturated monomers, which polymers or copolymers have molecular weights of from 200 to 50,000, are liquid at room temperature, soluble in the reaction mixture, and inert toward isocyanate groups and at least one metal salt of a monocarboxylic acid having at least 8 carbon atoms, are incorporated into the reaction mixture.
摘要:
The present invention is directed to a process for the production of optionally cellular, polyurethane and/or polyurethane-urea moldings having an impervious skin by reacting in a closed mold a reaction mixture containing(a) at least one organic polyisocyanate,(b) at least one compound which has a molecular weight of about 400 to 12,000 and at least two isocyanate-reactive groups, and(c) optionally at least one compound which has a molecular weight of from 32 to 399 and at least two isocyanate-reactive groups,wherein before the reaction takes place a surface-improving additive (e) is added containing(e1) a liquid and sedimentation-stable polymer dispersion which is produced by the free radical addition polymerization or copolymerization of one or more olefinically unsaturated monomers in a high molecular weight compound having isocyanate-reactive groups of the type mentioned in (b),and optionally(e2) a metal salt of a monocarboxylic acid having at least 8 carbon atoms in the moleculewherein additive (e) is used in a quantity such that about 0.01 to 3 parts by weight of polymer solids of the polymer dispersion (e1) and up to about 2 parts by weight of metal salt (e2) are incorporated per 100 parts of component (b).
摘要:
Urethane-modified polyisocyanate compositions are made by reacting (a) an organic polyisocyanate or mixture of polyisocyanates having an NCO-content of from 5 to 45 wt % with (b) a hydantoin having an OH number of from 56 to 596 and containing two alcoholic hydroxyl groups. These reactants are used in quantities such that the NCO:OH equivalent ratio is from 2:1 to 50:1. The preferred polyisocyanates are 4,4'-diisocyanatodiphenylmethane and isomer mixtures thereof. The most preferred hydantoin is 5,5-dimethyl hydantoin. These urethane-modified polyisocyanates are particularly useful in the production of polyisocyanate addition products such as polyurethanes and polyisocyanurates.
摘要:
The present invention relates to a process for the production of polyurethane molded articles in which the polyurethane-forming mixture applied to reinforcing fiber layer(s) or a reinforcing fiber mat includes a gas and a foam stabilizer. These molded articles are useful in automotive and construction applications and in furniture.