Patent ID: 8729162

Claim:
A cured vinyl ester resin composition, comprising a primary resin system comprising: (a) a peroxide cured vinyl ester resin, (b) a manganese compound which is a manganese carboxylate or a manganese acetoacetate, (c) a 1,3-dioxo compound having the following formula: wherein, X,Y═H, C 1 -C 20 alkyl, C 6 -C 20 aryl, alkylaryl, arylalkyl, part of a polymer chain, OR 3 , NR 3 R 4 ; R 1 , R 2 , R 3 , and R 4 each individually may represent hydrogen (H), or a C 1 -C 20 alkyl, C 6 -C 20 aryl, alkylaryl or arylalkyl group, that each optionally may contain one or more hetero-atoms selected from the group consisting of oxygen, phosphor, nitrogen and sulphur atoms; and/or substituents; a ring may be present between R 1 and R 2 , R 1 and R 3 , and/or between R 2 and R 4 ; R 3 and/or R 4 may be part of a polymer chain, may be attached to a polymer chain or may contain a polymerizable group, and (d) a base, wherein the base is an organic base with pKa≧10 selected from amines or the base is an alkaline metal or earth alkaline metal compound, wherein the amount of the 1,3-dioxo compound is between 0.05 and 5% by weight, calculated on the total weight of the primary resin system, and wherein the base is present in an amount of from 0.001 to 2000 mmol/kg of the primary resin system, and wherein the composition has a molar ratio between the manganese compound and a basic functionality of the base of 1:1 to 1:1500.