Patent GB-1046495-A (GB)
Title: Cross-linked plastics
IPC: C08F8/30
Filed: 1963-08-01
Abstract: A process for producing cross-linked plastics comprises mixing (A) a carboxylic acid having a molecular weight from 500 to 1 million, 1-30% by weight of carboxyl groups and at least 2 carboxyl groups in the molecule with (B) an isonitrile having 2 to 4 isocyano groups and a maximum molecular weight of about 500, in such amounts that the ratio of carboxyl groups to isonitrile groups is from 0.2:1 to 2:1. Cross-linking is generally effected at temperatures from 0 DEG  to 200 DEG  C. with or without a solvent; accelerators may be present, e.g. compounds of Mg, Zn, B, Al, Si, Ti, Co, Sn or Mn, specific examples being manganese naphthenate, boron trifluoride etherate, dioctyl tin laurate and tetrabutyl orthotitanate.  Other substances may additionally be present during cross-linking, particularly compounds containing primary or secondary amino groups, hydrazide groups and/or hydroxyl groups, e.g. dimethylhydrazine, stearylamine, ethanolamine, n-butylamine, benzhydrazide, N,N1-diisobutylidene - hexamethylene diamine and morpholine.  The products can be additionally cross-linked or vulcanized by using sulphur, formaldehyde, hexamethylene tetramine or dicumyl peroxide.  The carboxylic acid polymer may be a homopolymer, copolymer or graft addition polymer, or a condensation product of a polyhydroxy compound and a polycarboxylic acid.  Long lists of cross-linking components (A) and (B) are provided.  The cross-linked products can be used in the production of foam materials using blowing agents, and can be admixed with various additives such as dyes, brighteners, stabilizers, plasticizers and fillers.  The products can be used in coating compositions, lacquers, adhesives &c.  In the Examples, the acid polymers used are copolymers of (1) methyl methacrylate-acrylic acid, (2) cyclohexyl methacrylate - dodecyl methacrylate - methacrylic acid, (3) methyl vinyl ketone-acrylic acid-butyl acrylate - styrene (4) acrylonitrile - butadiene-acrylic acid, (5) butyl acrylate-acrylic acid, (6) acrylic acid-acrylonitrile, (7) acrylic acid-vinyl acetate-vinyl chloride, (8) acrylic acid-vinyl acetate, (9) ethylene-vinyl alcohol (obtained by saponification of ethylene-vinyl acetate copolymer) esterified with succinic anhydride, (10) styrene-methacrylic acid-butyl acrylate, (11) acrylic acid-hydroxypropyl methacrylate-ethyl acrylate, (12) isoprene-cyclohexyl hydrogen maleate, (13) vinylidene chloride-methyl methacrylate-methacrylic acid in the presence or absence of methyl methacrylate-methyl vinyl ketone copolymer, (14) butyl acrylate-acrylic acid-styrene (15) dodecyl methacrylate-styrene-methacrylic acid, (16) methacrylic acid-methyl methacrylate-ethyl acrylate, (17) acrylic acid-ethyl acrylate, (18) butyl acrylate-ethyl acrylate, partially saponified with aqueous NaOH; and condensation polymers of (19) pyromellitic anhydride and adipic acid-ethylene glycol polyester and (20) 1,2,4-benzene-tricarboxylic acid anhydride and the transesterification product of linseed oil and 1,1,1-trimethylol propane. The isonitriles used in the examples are bis-(4-isocyano - 3,5 - diethylphenyl) - methane, 1,4-diisocyano - cyclohexane, an isomeric mixture of diisocyano-diethyl toluenes and the reaction product of 3 mols. of this mixture with 1 mol. citric acid and 3 mols. cyclohexanone (a trifunctional isonitrile), a mixture of 1,4-bis-(isocyanomethyl)-cyclohexane with CN-(CH2)6-NC and CH3-N-(CH2CH2CH2-NC)2, CN-CH(CH2CH2CH2CH2CH2-NC)2, bis - (4 - isocyanomethyl - phenyl) ether, and N(CH2CH2CH2-NC)3.