Preparation of prepregs from cellulosic fibers using water-borne resin compositions

Claim 1

A method for the production of prepregs which comprises (1) impregnating cellulosic fibers with a water-borne composition comprising (a) a photopolymerisable resin, and (b) an epoxide resin, and then (2) exposing the impregnated fibers to actinic radiation so that (a) becomes photopolymerised, (a) being of formula ##STR21## where b represents zero or 1, e is an integer of at least 1, each R 14 denotes a hydrogen atom or a methyl group, each R 15 represents the divalent residue of a compound having two glycidyl groups directly attached to an atom or atoms of oxygen, nitrogen, or sulphur, after removal of the said two glycidyl groups, each R 16 represents the divalent residue of a dihydric alcohol, a dihydric phenol, a dicarboxylic acid, or a compound containing two groups selected from amide groups and imide groups, after removal of two terminal hydrogen atoms attached to an atom or atoms of oxygen or nitrogen, each R 17 denotes an alkylene group of 1 to 6 carbon atoms, an alkenylene group of 2 to 10 carbon atoms, an arylene group of 6 to 10 carbon atoms, or a cycloalkylene or cycloalkenylene group of 5 to 8 carbon atoms, each R 18 denotes a divalent aliphatic, cycloaliphatic, or araliphatic group of 2 to 8 carbon atoms, with the proviso that at least 25% of the total of the (e+1) R 15 and e R 16 groups each represent a group of the formula ##STR22## or a group of formula --O(OC).sub.d --R.sup.20 --(CO).sub.d --O-- X wherein R 4 represents a divalent aliphatic, cycloaliphatic, or araliphatic radical of 1 to 8 carbon atoms, each R 19 denotes an alkyl group of 1 to 4 carbon atoms or each pair of R 19 conjointly represents a group of formula ##STR23## c and d are each zero or 1, R 20 represents a straight or branched chain aliphatic group of 2 to 20 atoms or, provided each d is 1, it may alternatively represent a group of formula ##STR24## and R 21 and R 22 either each denote a hydrogen atom or a straight or branched alkyl group of up to 9 carbon atoms or together they denote a tetramethylene, pentamethylene, methylpentamethylene, or hexamethylene group.

Claim 2

A method for the production of prepregs which comprises (1) impregnating cellulosic fibers with a water-borne composition comprising (a) a photopolymerisable resin, and (b) an epoxide resin, and then (2) exposing the impregnated fibers to actinic radiation so that (a) becomes photopolymerised, (a) being of formula ##STR21## where b represents zero or 1, e is an integer of at least 1, each R 14 denotes a hydrogen atom or a methyl group, each R 15 represents the divalent residue of a compound having two glycidyl groups directly attached to an atom or atoms of oxygen, nitrogen, or sulphur, after removal of the said two glycidyl groups, each R 16 represents the divalent residue of a dihydric alcohol, a dihydric phenol, a dicarboxylic acid, or a compound containing two groups selected from amide groups and imide groups, after removal of two terminal hydrogen atoms attached to an atom or atoms of oxygen or nitrogen, each R 17 denotes an alkylene group of 1 to 6 carbon atoms, an alkenylene group of 2 to 10 carbon atoms, an arylene group of 6 to 10 carbon atoms, or a cycloalkylene or cycloalkenylene group of 5 to 8 carbon atoms, each R 18 denotes a divalent aliphatic, cycloaliphatic, or araliphatic group of 2 to 8 carbon atoms, with the proviso that at least 25% of the total of the (e+1) R 15 and e R 16 groups each represent a group of the formula ##STR22## or a group of formula --O(OC).sub.d --R.sup.20 --(CO).sub.d --O-- X wherein R 4 represents a divalent aliphatic, cycloaliphatic, or araliphatic radical of 1 to 8 carbon atoms, each R 19 denotes an alkyl group of 1 to 4 carbon atoms or each pair of R 19 conjointly represents a group of formula ##STR23## c and d are each zero or 1, R 20 represents a straight or branched chain aliphatic group of 2 to 20 atoms or, provided each d is 1, it may alternatively represent a group of formula ##STR24## and R 21 and R 22 either each denote a hydrogen atom or a straight or branched alkyl group of up to 9 carbon atoms or together they denote a tetramethylene, pentamethylene, methylpentamethylene, or hexamethylene group.