SILOXANE COPOLYMER CONTAINING ALKENYLOXY GROUP, ITS PREPARATION, CROSSLINKABLE ORGANOPOLYSILOXANE COMPOSITION CONTAINING SAME AND PREPARATION OF PHOTOCURABLE COATING MATERIAL

摘要

A siloxane copolymer contg. 2 or more alkenyloxy gps. is claimed as is also its prepn.. The copolymer contains (a) siloxane units of formula RaSi(OR')bO(4-(a+b))/2 (I); (b) at least one siloxane of formula QRcSiO(4-(c+1))/2 (II) per mol; and opt. also (c) at least one unit of formulae O(4-(c+1))/2RcSi-Q1-(SiRcO(4-(c+1))/2)n (III); R = opt. halogenated 1-18C hydrocarbon (same or different); R' = 1-4C alkyl (same or different) opt. substd. by ether O; a and b = 0, 1, 2 or 3 with a+b not greater than 3; c = 0, 1 or 2; n = 1-3; Q = -CH2CHR2CHR2OY (OCR2=CR2Me)x-1; R3 = H or Me (same or different); Y = (a) a 3-, 4-, 5-, or 6-valent 2-20C hydrocarbon which can be interrupted by O, S or CO or which can be substd. by halogen, -OH, -OR3 (where R3 = 1-6C alkyl), -OSi(R4)3 (where R4 = Me, Et, isoPr, t.Bu or Ph) or -OC(O)R3; (b) = P, P=O or SiR5 or (c) a 4-valent element such as C, Si or Ti; R5 = 1-8C monovalent hydrocarbon; x= 3, 4, 5 or 6; and Q1 = gps. of formulae (VI), (VII) and (VIII). -