Granted Patent B2

US 7,589,152 · App. 11/010,906 · Granted Sep 15, 2009

Abstract

Claims (38)

1. A block copolymer composition comprising:

a. a tetra-branched block copolymer (IV) represented by the general formula (A-B) 4 X;

b. a tri-branched block copolymer (III) represented by the general formula (A-B) 3 X;

c. a di-branched block copolymer (II) represented by the general formula (A-B) 2 X; and

d. a linear diblock copolymer (I) represented by the general formula A-B; where:

i. A represents a polymer block of a mono alkenyl arene;

ii. B represents a polymer block of a mixture of isoprene and 1,3-butadiene having a random distribution in a weight ratio of isoprene to butadiene from 70:30 to 40:60;

iii. X represents the residue of a multi-functional coupling agent selected from silicon halides, siloxanes, epoxy alkoxysilanes, esters of monohydric alcohols with carboxylic acids, epoxidized oils, epoxides and divinylaromatics;

iv. the weight percent of A blocks is from 14% to 22%;

v. the relative amounts of copolymers IV, III, II, and I are from 0 to 20 weight percent IV, from 50 to 80 weight percent III, from 0 to 20 weight percent II and from 20 to 50 weight percent I, where the total of I, II, III and IV equals 100 weight percent; and

vi. the melt flow rate of the polymer composition is at least 2.0 g/10 minutes at 200° C./5 kg as measured by ASTM D1238 (D condition).

2. The block copolymer composition of claim 1 wherein said mono alkenyl arene is styrene.

3. The block copolymer composition of claim 2 wherein said block B has a glass transition temperature (Tg) less than −50° C. as determined according to ASTM E-1356-98.

4. The block copolymer composition of claim 3 wherein said multi-functional coupling agent is selected from the group comprising silicon halides, siloxanes, alkoxysilanes, epoxy alkoxysilanes, esters of monohydric alcohols with carboxylic acids, epoxidized oils, epoxides and divinylaromatics.

5. The block copolymer composition of claim 4 wherein each block A has a weight average molecular weight of 5,000 to 17,000 and each B block has a weight average molecular weight of 50,000 to 100,000.

6. The block copolymer composition of claim 5 wherein:

a. the relative amounts of copolymers IV, III, II, and I are from 1 to 15 weight percent IV, from 50 to 70 weight percent III, from 1 to 10 weight percent II and from 30 to 50 weight percent I, where the total of I, II, III and IV equals 100 weight percent; and

b. the weight ratio of isoprene to butadiene in each block B is from 60:40 to 50:50.

7. The block copolymer composition of claim 6 wherein the weight percent styrene is from 15% to 21%.

8. The block copolymer composition of claim 7 wherein the melt flow rate is greater than or equal to 5.0 g/10 min as measured by D1238 (D condition).

9. The block copolymer composition of claim 7 wherein the coupling agent residue (X) is formed from glycidoxy propyl trimethoxy silane (GPTS), or tetramethoxysilane.

10. An adhesive composition comprising (i) one or more block copolymers, (ii) one or more tackifying resins, and (iii) optionally, one or more plasticizers, wherein at least one of the block copolymers is a block copolymer composition comprising:

a. a tetra-branched block copolymer (IV) represented by the general formula (A-B) 4 X;

b. a tri-branched block copolymer (III) represented by the general formula (A-B) 3 X;

c. a di-branched block copolymer (II) represented by the general formula (A-B) 2 X; and

d. a linear diblock copolymer (I) represented by the general formula A-B; where:

i. A represents a polymer block of a mono alkenyl arene;

ii. B represents a polymer block of a mixture of isoprene and 1,3-butadiene having a random distribution in a weight ratio of isoprene to butadiene from 70:30 to 40:60;

iii. X represents the residue of a multi-functional coupling agent selected from silcon halides, siloxanes, epoxy alkoxysilanes, esters of monohydric alcohols with carboxylic acids, epoxidized oils, epoxides and divinylaromatics;

iv. the weight percent of A blocks is from 14% to 22%;

v. the relative amounts of copolymers IV, III, II, and I are from 0 to 20 weight percent IV, from 50 to 80 weight percent III, from 0 to 20 weight percent II and from 20 to 50 weight percent I, where the total of I, II, III and IV equals 100 weight percent; and

vi. the melt flow rate of the polymer composition is at least 2.0 g/10 minutes at 200° C./5 kg as measured by ASTM D1238 (D condition).

11. The adhesive composition of claim 10 wherein said tackifier resin has an aromaticity (in relative percentage of aromatic protons as determined by H—NMR)of from 3 to 18%.

12. The adhesive composition of claim 11 where said adhesive composition comprises 100 parts by weight of said block copolymer composition and 50 to 400 parts by weight of said tackifier resin.

13. The adhesive composition of claim 12 also containing 5 to 150 parts by weight of a plasticizer.

14. The adhesive composition of claim 12 wherein said mono alkenyl arene is styrene.

15. The adhesive composition of claim 14 wherein said block B has a glass transition temperature (Tg) less than −50° C. as determined according to ASTM E-1356-98.

16. The adhesive composition of claim 15 wherein each block A has a weight average molecular weight of 5,000 to 17,000 and each B block has a weight average molecular weight of 50,000 to 100,000.

Assignments (13)