GB939465A - Polyurethane foam - Google Patents

Abstract

A process for the production of a substantially rigid polyurethane foam having predominantly closed pores comprises reacting an organic polyisocyanate, a polyol having a molecular weight of from 100 to 600 and containing at least one tertiary nitrogen atom and at least three hydroxyl groups, and tall oil (the amount of tall oil in the resulting mixture calculated on the combined weight of the polyol and the tall oil being from 30% by weight to 90% by weight) and simultaneously or subsequently foaming the reaction mixture by means of a blowing agent. Suitable polyisocyanates are listed, and include crude 4,41-diphenylmethane diisocyanate and crude 2,4- or 2,6-toluene diisocyanates which contain hydrolysable chlorine, such materials giving products of greater dimensional stability. A mixture of di- and tri-isocyanates can be used. The polyol containing tertiary nitrogen can be obtained by condensing a polyamine with an alkylene oxide. A number of aliphatic, aromatic and heterocyclic polyamines are listed. The aromatic compounds may contain alkyl, alkoxy, nitro or hydroxyalkylene substituents. A diamine which contains one primary and one secondary amino group can also be used. Hydroxy poly(alkylene thioether) derivatives are also suitable starting materials. Blowing of the products can result from the presence in the reaction mixture of water, an inert gas such as air, nitrogen, carbon dioxide or argon, or trichlorofluoromethane or other chlorofluoroalkane, or pentane or hexane. One shot or prepolymer methods can be used. As catalysts tin compounds and tertiary amines are listed. A silane oxyalkylene block copolymer is also preferably present in the reaction mixture. In Example (1) there are mixed tall oil and N,N,N1,N1-tetrakis-(2-hydroxypropyl) ethylene diamine, and then, using the apparatus of Specification 769,682, there are mixed in crude 4,41-diphenylmethane diisocyanate containing hydrolysable chloride, a silicone oil, and trichlorofluoromethane. The mixture is discharged into a cavity and rises and sets to a rigid foam. In other generally similar Examples (2) to (5) the polyol is a propylene oxide/tolylene diamine condensate and there are used as catalysts a mixture of 1-methyl-4-dimethylaminoethyl-piperazine and stannous octoate. In Example (5) water replaces trichlorofluoromethane as blowing agent. Specifications 769,680, 804,369 and 939,464 also are referred to.ALSO:A process for the production of a substantially rigid polyurethane foam having predominantly closed pores comprises reacting an organic polyisocyanate, a polyol having a molecular of from 100 to 600 and containing at least one tertiary nitrogen atom and at least three hydroxyl groups, and tall oil (the amount of tall oil in the resulting mixture calculated on the combined weight of the polyol and the tall oil being from 30% by weight to 90% by weight) and simultaneously or subsequently foaming the reaction mixture by means of a blowing agent. Suitable polyisocyanates are listed, and include crude 4, 41- diphenyl-methane diisocyanate and crude 2, 4- or 2, 6-toluene diisocyanates which contain hydrolysable chlorine, such materials giving products of greater dimensional stability. A mixture of di- and triisocyanates can be used. The polyol containing tertiary nitrogen can be obtained by condensing a polyamine with an alkylene oxide. A number of aliphatic, aromatic and heterocyclic polyamines are listed. The aromatic compounds may contain alkyl, alkoxy, nitor or hydroxyalkylene substituents. A diamine which contains one primary and one secondary amino group can also be used. Hydroxy poly(alkylene thioether) derivatives are also suitable starting materials. Blowing of the products can result from the presence in the reaction mixture of water, an inert gas such as air, nitrogen, carbon dioxide or argon, or trichlorofluoromethane or other chlorofluoroalkane, or pentane or hexane. One-shot or prepolymer methods can be used. As catalysts tin compounds and tertiary amines are listed. A silane oxyalkylene block copolymer is also preferably present in the reaction mixture. In Example (1) there are mixed tall oil and N, N, N1, N1- tetrakis(3-hydroxypropyl)ethylene diamine, and then, using the apparatus described in Specification 769,682, there are mixed in crude 4, 41-diphenylmethane diisocyanate containing hydrolysable chloride, a silicone oil, and trichlorofluoromethane. The mixture is discharged into a cavity and rises and sets to a rigid foam. In other, generally similar Examples (2) to (5) the polyol is a propylene oxide/tolylene diamine condensate and there are used as catalysts a mixture of 1-methyl-4 dimethyl-aminoethyl-piperazine and stannous octoate. In Example (5) water replaces trichlorofluoromethane as blowing agent. Specifications 769,680, 804,369 and 939,464 also are referred to.