Patent GB-802245-A (GB)
Title: New synthetic resins
Inventor: RAYNER LAURENCE STEPHEN
IPC: C08G18/42
Filed: 1955-07-06
Abstract: The invention comprises a synthetic resin prepared by reacting, under substantially anhydrous conditions, a polyester of tetramethylene glycol or pentamethylene glycol and glutaric acid with a diisocyanate in more than equimolecular amount, based on the polyester, the said polyester having an average molecular weight of at least 1000. Preferably, the esters have molecular chains terminating mainly in hydroxyl groups and are obtained by reacting 1.5 to 2 mols. of glycol per mol. of acid.  Ester-forming derivatives of the glycol or acid may be used.  The products of the invention have preferably (by suitable choice of reactant proportions) a molecular weight of about 7000 to 8000.  Suitable diisocyanates are 2-nitrodiphenylene - 4,41-, diphenylmethane - 4,41, 2-nitrodiphenylmethane - 4,41, naphthylene - 1,4, -1,5 or -2,7, fluorene-2,7, chrysene-2,8, 1-chlorophenylene-2,4, tolylene-2,4 or -2,6, dicyclohexylmethane - 4,41, diporoxylylmethane - 4,41, diphenylene - 4,41, 4,41 - cyclohexylphenyl, 3,31-dimethoxy - 4,41 - diphenylene and 3,31 - dimethyl and 4,41-diphenylene diisocyanates.  The reaction is preferably effected at 120 DEG  to 160 DEG  C.  To moderate the reaction acidic materials or materials capable of forming acids, such as sulphur dioxide, boric acid, adipic acid, salicylic acid or butadiene sulphone.  The diisocyanate may be reacted with the polyester in two stages.  The synthetic resins produced by the above processes can be converted into rubber-like material by heating in the presence of an inorganic base, an alkoxide or a tertiary amine. Alternatively, there may be used a cross-linking agent such as water, glycols, diamines having primary or secondary amino groups, dicarboxylic acids, hydroxy acids, hydroxy amines or amino acids, e.g. glycol, 1 : 3-propanediol, 1 : 4-butane diol, ethylene diamine, tri- or tetramethylene diamine, m-phenylene diamine, o- and m-dichlorobenzidine, dianisidine, 4,41-diamino-diphenyl-methane, naphthylene diamines, tolylene 2,4-diamine, aminobenzylaniline, aminodiphenylamine, 2-aminoethyl alcohol, 2-amino-1-naphthol, m-aminophenol, glycollic acid, a -hydroxy-propionic acid, aminoacetic acid and aminobenzoic acid. Preferably, such organic cross-linking agents are used together with water.  The water may be used as water of crystallization, e.g. in cobaltous chloride hexahydrate or may be applied from the atmosphere. The water content of the resin to be cross-linked may be controlled by heating in an atmosphere of low humidity.  An expanded product can be produced when water is the cross-linking agent is water.  The cross-linking may be controlled by the methods described in Specifications 767,017 and 773,991. Examples illustrate the invention, with 1 : 5-naphthylene diisocyanate or 3,31-dimethoxy-4,41-diphenylene diisocyanate as the diisocyanate, water or butanediol-1 : 4 as the cross-linking agent and salicylic acid as the moderating agent. The Provisional Specification relates to a similar process in which the polyester is prepared by reacting a glycol of the formula HO(CH2)xOH with an acid of the formula HOOC.(CH2)y.COOH, x being from 2 to 7 but not 3 y being from 0 to 7, the sum of x and y being from 7 to 10, y being 7 if x is 2, the CH2 groups being unreactive with isocyanate groups, the polyester having a molecular weight of at least 1000 and a melting point not higher than 50 DEG  C.  Further esters specified are poly-(ethylene azelate), poly-(pentamethylene succinate), poly-(pentamethylene pimelate), poly-(hexamethylene glutarate) and poly-(heptamethylene oxalate).