high haertbare to elastomers on the basis of polysiloxan polyurethane mischpoly - european union

摘要

1532971 Silicone moulding compositions containing silylated polyurethane prepolymers BAYER AG 19 Sept 1975 [21 Sept 1974] 38530/75 Heading C3T A moulding composition comprises (a) a polysiloxane HO(R 2 SiO) n H, wherein each R is H, alkyl, alkaryl, aryl or haloalkyd and n is at least 3; (b) a silylated polyurethane prepolymer wherein RSP1/SP is a C 1-8 alkyl or C 8-14 cycloalkyl radical, RSP11/SP is an optionally halo- or cyanosubstituted C 1-10 alkyl, C 4-10 cycloalkyl or C 6-10 aryl radical; RSP111/SP is H, CH 3 - or C 6 S-; RSP1111/SP is H or as RSP11/SP; QSP1/SP is a C 4-36 alkylene, C 4-14 cycloalkylene, C 7-46 aralkylene or alkarylene or a C 6-14 arylene radical; X is -O-, -NH- or -NY- (Y being C 1-8 alkyl); and Q is derivable from a compound Q(XH) 2 of M.W. 200-80,000, containing at least one ester, ether, urethane, urea, carbonate or amide group and optionally at least one siloxane group; and (c) a compound containing at least 3 hydrolysable groups attached to each Si atom. In Example 1 component (b) is prepared by treating (i) a polypropylene glycol with (ii) TDI and (iii) C 6 H 11 -NH-CH 2 SiMe 2 OEt in 1 : 2 : 2 molar ratio. In Examples 5-9 and 12 there is used instead of (i) an adipic acid-hexamethylene glycolneopentyl glycol (Ex. 5), instead of (ii) hexamethylene or isophorone diisocyanate (Examples 7 and 8), instead of (iii) C 6 H 5 -CH 2 -NH-CH 2 SiMe 2 OEt or (Ex. 12), and molar ratios of about 2 : 3 : 1 (Examples 6-8) or 5 : 6 : 1 (Ex. 9); additional polysiloxane diol is then added in Examples 5-8. In Examples 4-12 moulding compositions are made from 30 p.b.w. of (a) a polydimethylsiloxane diol of 45,000 c.p., 31 p.b.w. of (b), 5 p.b.w. of (c) MeSi(ON=CMeEt) 3 , 24 p.b.w. of (d) a trimethylsilyl-terminated polydimethylsiloxane, and 10 p.b.w. SiO 2 and 0À05 p.b.w. of dibutyltin dilaurate; in Examples 1-3 20, 28 and 20 p.b.w. of (a) are used with 63, 55 and 41 p.b.w. (b), 7, 7 and 5 p.b.w. of (c) and 0, 0 and 24 p.b.w. (d), 10 p.b.w. silica and 0À05 of catalyst.