2-Hydroxypropane sulphonic acid derivatives; their preparation and curable compositions containing them

Claim 2

A 2-hydroxypropane sulphonic acid derivative of general formula wherein n is a number having an average value from 0 to 12, Ⓐ denotes saturation or aromatic unsaturation in an associated carbocyclic ring, and the or each of the R 1 and R 2 groups are independently selected from hydrogen and C 1-12 alkyl groups provided that the or each -C(R 1 )(R 2 )-group contains not more than 13 carbon atoms; or a salt thereof.

Claim 3

A derivative according to Claim 1 wherein each Ⓐ moiety denotes aromatic unsaturation, n has an average value from 0 to 9 and the R 1 and R 2 groups are methyl groups.

Claim 4

A derivative according to claim 1 or 2 in the form of the free acid or a tertiary or quaternary ammonium salt thereof.

Claim 5

A process for preparing a derivative of formula I as defined in claim 1, 2 or 3 characterised in that an epoxy resin of general formula wherein R , R 2 , n and Ⓐ are as defined in claim 1 or 2, is reacted with an ammonium sulphite or bisulphite of formula or wherein R 3 is hydrogen and either R 4 , R 5 and R 6 are independently, selected from C 1-6 alkyl and 2-hydroxyalkyl groups or R 4 is a benzyl group optionally substituted by a methyl, methoxy or trifluoromethyl group and/or one or more halogen atoms or nitro groups and R 5 is a methyl group and R is a methyl, ethyl or 2-hydroxyethyl group, provided that the total number of carbon atoms in the groups R , R 5 and R 6 does not exceed 10; or R , R , R and R are independently C 1-4 alkyl groups; or R , R and R are methyl groups and R 6 is a benzyl group or a C 5-16 alkyl group; in homogeneous solution in an inert solvent, optionally followed by evaporation of the solvent to isolate the corresponding ammonium salt of the sulphonic acid of formula I, or by addition of a strong acid followed by separation of the precipitated free acid, or by conversion of the ammonium salt or the free acid to a desired salt.

Claim 6

A curable composition comprising a 2-hydroxypropane sulphonic acid derivative of formula I or a salt thereof according to any one of claims 1 to 3, and a co-curing resin.