Patent GB-932960-A (GB)
Title: New acetals containing epoxide groups
IPC: C08G59/24
Filed: 1960-08-31
Abstract: Curable mixtures contain an acetal which contains at least two epoxide groups and corresponds to the formula <FORM:0932960/IV(a)/1> in which X1 and X2 each represent a hydrogen atom or a methyl group, Z is an organic residue containing at least one epoxide group, n is 1, 2 or 3, and Y is the residue of a polyhydric alcohol with 2n free valences and, when n=1, the residue Y must contain at least one epoxide group, together with a curing agent for epoxy resins. Preferred epoxy acetals are those in which Y is a 1:1-bis[hydroxymethy]-3:4-epoxycyclohexane radical which may contain alkyl groups or a 2:5-endo-alkylene radical, and/or Z is 3:4-epoxycyclohexylmethyl radical, which may contain alkyl groups or a 2:5-endo-alkylene radical.  Suitable curing agents are amines, amides, guanidine or derivatives, dicyandiamide, aniline-, urea- or melamine-formaldehyde resins, aminostyrene polymers, polyamides, isocyanates, isothiocyanates, polyhydric phenols, phenolaldehyde resins, reaction products of aluminium alcoholates or phenolates with compounds of tautomeric reaction such as acetoacetic ester, Friedel Crafts catalysts, or phosphoric acid.  Preferred curing agents are polybasic carboxylic acids and anhydrides thereof, such as phthalic anhydride. Accelerators such as tertiary amines, strong Lewis bases, and polyhydroxy compounds may also be added.  The curable mixtures may also contain a proportion of acetals whose epoxide groups are wholly or partially hydrolysed to hydroxyl groups, or other epoxides such as mono- or polyglycidyl esters of mono-or polyalcohols of mono- or polyphenols, polyglycidyl esters of polycarboxylic acids or aminopolyepoxides.  Fillers, extenders, plasticizers and colouring matter may be included.  Specification 887,593 is referred to.ALSO:The invention comprises new acetals, containing at least two epoxide groups of the formula <FORM:0932960/IV(a)/1> in which X1 and X2 each represent a hydrogen atom or a methyl group; Z represents an organic residue containing at least one epoxide group; n is 1, 2 or 3; and Y represents the residue of a polyhydric alcohol with 2n free valences and, when n = 1, the residue Y must contain at least one epoxide group.  For example, Z may be a glycidyl group, or a 3:4-epoxytetrahydrodicyclopentadiene-(8)-yl residue or a 3:4epoxycyclohexylmethylene radical, and Y may be a 3:4-epoxycyclohexyldimethylene radical.  Examples of such compounds are those of the types:- <FORM:0932960/IV(a)/2> and <FORM:0932960/IV(a)/3> and <FORM:0932960/IV(a)/4> and a similar triepoxide-triacetal, where X1 and X11 each stands for a methyl group or a hydrogen atom, and R1 to R9 and R11 to R10 each stand for monovalent substituents such as halogen or hydrocarbon residues, or hydrogen atoms, or R1 and R5 together or R11 and R15 together may form an alkylene residue, and A represents a tetravalent aliphatic residue which may be unsubstituted or substituted by hydroxyl, ether, sulphide, carboxy, carboxylic acid ester, keto, aldehyde or acetal groups.  The novel epoxides may be made by epoxidising the corresponding acetal containing at least one epoxidisable group, such as a double bond or halohydrin group, or by reacting n mols of a compound of the formula Z-OH with one mol of an unsaturated acetal of the formula <FORM:0932960/IV(a)/5> An unsaturated acetal of the above formula in which Y is replaced by Y1, where Y1 contains at least one epoxide or epoxidisable group, is made by heating methacrolein, crotonic aldehyde or acrolein with a dialcohol, such as butene-(2)-diol-1:4, glycerol monoallyl ether, butane-triol-(1 : 2 : 4)-monoallyl ether, or 1:1-bis-[hydroxymethyl]-cyclohex-3-enes which may contain halogen, alkoxy or hydrocarbon groups, or a polyalcohol containing at least four hydroxyl groups, e.g. erythritol, pentaerythritol, pentitols, hexitols, heptitols, 21-2:6:6-tetramethylol cyclohexanol-(1), sugar, or sugar acids, in the presence of an acid catalyst.  The unsaturated acetal may be reacted with an alcohol of the formula Z1-OH, such as a chlorohydrin or unsaturated alcohol, or with an aliphatic or cycloaliphatic diol or polyol.  Any free hydroxyl groups in the product can be further reacted with compounds containing in addition to epoxidisable groups such groups as can be condensed with hydroxyl groups, e.g. carboxyl, hydroxyl or halogen.  Detailed examples are given.  Specification 887,593 is referred to.