Sealant composition

A two-part condensation curable silyl modified polymer-based sealant composition comprising a base part, Part A, and a catalyst package, Part B,

• wherein the base part comprises:
• (a) a silyl modified organic polymer having at least two (R)m(Y1)3-m—Si— groups per molecule where each R is hydroxyl or a hydrolysable group, each Y1 is an alkyl group containing from 1 to 8 carbons and m is 1, 2 or 3, which organic polymer is selected from polyethers, hydrocarbon polymers, acrylate polymers, polyesters, polyurethanes, and polyureas;
• and
• (b) a reinforcing filler;
• and
• optionally, further comprising:
• (c) one or more plasticisers;
• and/or
• (d) one or more stabilizers;
• and
• wherein the catalyst package comprises:
• (ai) a silyl modified organic polymer having at least two (R)m(Y1)3-m—Si— groups per molecule where each R is hydroxyl or a hydrolysable group, each Y1 is an alkyl group containing from 1 to 8 carbons and m is 1, 2 or 3, which organic polymer is selected from polyethers, hydrocarbon polymers, acrylate polymers, polyesters, polyurethanes, and polyureas;
• (e) a catalyst comprising (i) a titanate and (ii) a zinc carboxylate salt comprising:
• zinc, and
• a carboxylate group conforming to the formula R15COO−, where R15 is an alkyl group;
• and
• (f) an adhesion promoter;
• and
• optionally, further comprising:
• (g) a cross-linker;
• and/or
• (h) a hydroxy scavenging agent selected from a disilazane or polysilazane;
• and
• wherein the titanate (i) and the zinc carboxylate salt (ii) of catalyst (e) is provided in a molar ratio of 4:1 to 2:1.