GB951399A - New acetals containing epoxy groups - Google Patents

Abstract

The invention comprises acetals containing at least two epoxide groups and of the formula: <FORM:0951399/C2/1> in which R1 to R9 each represent a hydrogen atom or a monovalent substituent such as a halogen atom, an alkoxy group or an aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon residue, and R1 and R5 together may also represent an alkylene radical such as a methylene group; #Z represents a trivalent aliphatic, cycloaliphatic or araliphatic hydrocarbon residue with at least 3 carbon atoms, none of which has more than a single free valence, and no carbon having such a free valence carries a hydroxyl group; n is 1 or 2; and, when n is 1, G is a radical of formula -#O-#U1 or -#O-C#O-#U1, where #U1 is an organic radical containing an epoxide group and, when n is 2, G is a radical of the formula -#O-, -#O-C#O-#O-, -#O-C#O-C#O-#O, or -#OC#O-#U2-#O-C#O-, where #U2 is an aliphatic, cycloaliphatic, araliphatic, or aromatic hydrocarbon radical. The epoxy compounds may be obtained by epoxidation of the compounds having a formula: <FORM:0951399/C2/2> in which when n is 1, G1 is -#O#U1 1 or -#OC#O#U1 1 where #U1 1 is an organic radical containing an epoxidisable group, such as a double bond or halohydrin grouping. The double bonds may be epoxidised with a peracid such as peracetic, perbenzoic, peradipic or mono-perphthalic acid, or by reaction with H#OCI followed by treatment with strong alkali. The unsaturated starting materials (IV) may be made by acetalising a D 3-tetra-hydrobenzaldehyde with a polyalcohol (H#O)2#Z-#C, where #C may be #O#H, Cl or Br., in the presence of an acid catalyst, or with an epoxide #O = #Z-#C. The product is an acetal of formula: <FORM:0951399/C2/3> This acetal may be converted to (IV) by etherification, esterification or re-esterification with a compound containing one or more reactive halogen atoms or groups containing active hydrogen atoms. Suitable types of compounds are epihalohydrins, dihalohydrins, unsaturated alcohols, glycerol diesters of unsaturated fatty acids, unsaturated carboxylic acids and functional derivatives, unsaturated halides, unsaturated acetals, carbonic acid, phosgene, and polycarboxylic acids, their acid halides or anhydrides. The acetals (IV) may also be made by acetalising the D 3-tetrahydrobenzaldehyde with a polyol of the formula (#H#O)2 #Z-G-#Z(#O#H)2, e.g., diglycerol, or with a dialcohol (#H#O)2 #Z-G1 such as an adduct of glycerol with dicyclopentadiene, or glycerol-monoallyl ether with cyclo-pentadiene. The preferred compounds of the invention are those of the formula: <FORM:0951399/C2/4> where R and R1 each represents hydrogen or C1-4 alkyl; Y2 is an aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon residue, and m and n are each 1 or 2, and those of the formula: <FORM:0951399/C2/5> in which R and R1 each represents hydrogen or C1-4 alkyl. Specification 932,960 is referred to.ALSO:Curable mixtures comprise at least one acetal of the formula: <FORM:0951399/C3/1> wherein R1 to R9 are hydrogen or monovalent substituents such as halogen, alkoxy or aliphatic cycloaliphatic, araliphatic or aromatic hydrocarbon residues, and R1 and R5 together may also represent an alkylene radical such as a methylene group; Z is a trivalent aliphatic, cycloaliphatic or araliphatic hydrocarbon residue with at least 3 carbon atoms, none of which has more than a single free valence, and no carbon having such a free valence carries a hydroxyl group; n is 1 or 2, and, when n is 1, G is a radical of formula -O-Y1- or -O-CO-Y1, where Y1 is an organic radical containing an epoxide group and, when n is 2, G is a radical of the formula -O-, -O-CO-O, -O-CO-CO-O-, or -OCO -Y2-OCO-, where Y2 is an aliphatic, cycloaliphatic, araliphatic or aromatic radical, together with a curing agent for epoxy resins. The curing agent is preferably an anhydride of a dicarboxylic, or polycarboxylic acid. Other suitable curing agents are amines and amides, dicyandiamides, formaldehyde resins with aniline, urea and melamine; polymers of aminostyrenes, polyamides, isocyanates, isothiocyanates, polyhydric phenols, phenol-aldehyde resins, reaction products of aluminium alcoholates and phenolates with compounds of tautomeric reaction, Friedel-Crafts catalysts, metal fluoborates and phosphoric acid. An accelerator such as a tertiary amine or a strong Lewis base and advantageously also a polyhydroxy compound, may be added. The curable mixtures may also contain a proportion of the above acetals whose epoxide groups have been wholly or partially hydrolysed to hydroxyl groups, and/or also other cross-linking polyhydroxy compounds, such as hexanetriol. Other epoxides, such as mono-glycidyl or polyglycidyl ethers of mono- or polyalcohols, or of mono- or polyphenols, polyglycidyl esters of polycarboxylic acids, or amino-polyepoxides. Fillers, plasticizers and colouring matters may be added. Specification 932,960 is referred to.