GELS PREPARED FROM DPE CONTAINING BLOCK COPOLYMERS
The present invention relates to gels prepared from novel anionic block copolymers of mono alkenyl arenes, diphenylethylenes and conjugated dienes, and to blends of such block copolymers with oils. The block copolymers are selectively hydrogenated and have mono alkenyl arene/diphenylethylene end blocks and conjugated diene mid blocks. The block copolymer may be combined with oils and other components to form the gels of the present invention.
1 . An oil gel composition comprising 100 parts by weight of at least one hydrogenated block copolymer composition and about 300 to about 2000 parts by weight of an extending oil, wherein said hydrogenated block copolymer comprises an A-B-A, an (A-B) n or an (A-B) n -X copolymer wherein:
i. A comprises a polymer block of a monoalkenyl arene and one or more 1,1-diphenylethylenes or its derivatives of the formula I:
wherein R 1 is hydrogen or an alkyl of 1 to 22 carbon atoms, a is 0, 1, 2, 3, 4, or5 and b is 0, 1, 2, 3, 4, or 5.;
ii. B represents a polymer block of a hydrogenated conjugated diene;
iii. X represents the residue of coupling agent; and
iv. n is an integer from 2 to 30.
2 . The oil gel composition according to claim 1 wherein the weight ratio of monoalkenyl arene to 1,1-diphenylethylene is from 97:3 to 30:70.
3 . The oil gel composition according to claim 2 wherein said mono alkenyl arene is styrene, said 1,1-diphenylethylene is unsubstituted and said conjugated diene is selected from the group consisting of isoprene and butadiene.
4 . The oil gel composition according to claim 3 wherein said conjugated diene is butadiene, and wherein prior to hydrogenation about 10 to about 80 mol percent of the condensed butadiene units in block B have 1,2-configuration.
5 . The oil gel composition according to claim 3 wherein said coupling agent is an alkoxy silane coupling agent selected from the group consisting of tetraethoxy silane, tetramethoxy silane, tetrabutoxy silane, methyl trimethoxy silane, methyl triethoxy silane, phenyl trimethoxy silane and isobutyl trimethoxy silane.
6 . The oil gel composition according to claim 5 wherein n is 2 to 4.
7 . The oil gel composition according to claim 3 wherein said A blocks have a number average molecular weight of between about 5,000 and about 60,000, and wherein said B blocks have a number average molecular weight of between about 10,000 and about 200,000.
8 . The oil gel composition according to claim 7 wherein the weight ratio of polymer block A to polymer block B is from 5/95 to 50/50.
9 . The oil gel composition according to claim 8 wherein said extending oil is a paraffinic/naphthenic process oil.
10 . The oil gel composition according to claim 9 wherein the amount of extending oil is between about 400 and about 1000 parts by weight.
11 . The oil gel composition according to claim 1 also comprising up to 30 percent by weight of a filler, based on the total formulation.
12 . An article prepared from the gel of claim 1 .