Thermoplastic polyurethane block copolymer compositions

1. A novel block copolymer composition comprising:

(a) a hydrogenated block copolymer that has at least one block A and at least one block B, and wherein:

a. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;

b. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced;

c. each A block having a number average molecular weight between about 3,000 and about 60,000 and each B block having a number average molecular weight between about 30,000 and about 300,000;

d. each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units;

e. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 5 percent weight to about 50 percent weight; and

f. the weight percent of mono alkenyl arene in each B block is between about 10 percent and about 75 percent; and

(b) about 50 to about 95 percent by weight of a thermoplastic polyurethane elastomer based on the weight of the novel block copolymer composition.

2. The composition according to claim 1 , further comprising between about 0.1 wt % to about 5 wt % of a maleated controlled distribution block copolymer based on the weight of the novel block copolymer composition.

3. The composition according to claim 1 , wherein the mono alkenyl arene is styrene.

4. The composition according to claim 1 , wherein the the conjugated diene is selected from the group consisting of butadiene and isoprene.

5. The composition according to claim 1 , further comprising oil in an amount between about 10 wt % to about 20 wt % based on the weight of the novel block copolymer composition.

6. The composition according to claim 1 , wherein the conjugated diene block comprises from about 1 wt % to about 20 wt % of a functionalized block copolymer.

7. The composition according to claim 1 wherein said A block in the novel block copolymer composition contains about 10 to about 30 percent by weight styrene.

8. The composition according to claim 1 , wherein said thermoplastic polyurethane is derived from the reaction of an organic diisocyanate, at least one polymeric diol, and at least one difunctional extender.

9. A novel block copolymer composition comprising:

(a) a hydrogenated block copolymer that has at least one block A and at least one block B, and wherein:

a. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;

b. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced;

c. each A block having a number average molecular weight between about 3,000 and about 60,000 and each B block having a number average molecular weight between about 30,000 and about 300,000;

d. each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units;

e. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 5 percent weight to about 50 percent weight; and

f. the weight percent of mono alkenyl arene in each B block is between about 10 percent and about 75 percent; and

(b) about 50 to about 95 percent by weight of a thermoplastic polyurethane elastomer based on the weight of the novel block copolymer composition.

10. The composition according to claim 9 , further comprising between about 0.1 wt % to about 5 wt % of a maleated controlled distribution block copolymer based on the weight of the novel block copolymer composition.

11. The composition according to claim 9 , wherein each B block contains between about 5 wt % to about 10 wt % of a functionalized polymer.

12. The composition according to claim 9 , wherein the thermoplastic polyurethane is derived from 4,4′-methylenebis(cyclohexyl isocyanate), a 2,000 molecular weight polyethyleneoxy capped polypropyleneoxy diol, and 1,4-butanediol.

13. The composition according to claim 9 , wherein thermoplastic polyurethane is derived from 4,4′-methylenebis(phenyl isocyanate), a blend of a 2,000 and 700 molecular weight polybutylene adipate diol, and 1,4-butanediol.

14. The composition according to claim 9 , wherein said thermoplastic polyurethane is a polyether based polyurethane.

15. The composition according to claim 9 , wherein the amount of polyurethane is about 50 to about 80 percent by weight.

16. A novel block copolymer composition comprising:

(a) a. a hydrogenated block copolymer that has at least one block A and at least one block B, and wherein:

b. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;

c. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced;

d. each A block having a number average molecular weight between about 3,000 and about 60,000 and each B block having a number average molecular weight between about 30,000 and about 300,000;

e. each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units;

f. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 5 percent weight to about 50 percent weight;

g. the weight percent of mono alkenyl arene in each B block is between about 10 percent and about 75 percent;

h. from about 10 wt % to about 20 wt % of oil based on the weight of the novel block copolymer composition; and

(b) about 50 to about 95 percent by weight of a thermoplastic polyurethane elastomer based on the weight of the novel block copolymer composition.

17. The composition according to claim 16 , further comprising between about 0.1 wt % to about 5 wt % of a maleated controlled distribution block copolymer based on the weight of the novel block copolymer composition.

18. The composition according to claim 16 , wherein the Shore A hardness is between about 70 to about 60 according to ASTM D2240.

19. The composition according to claim 16 , wherein the light transmittance is between about 80 % to about 90 %.

20. The composition according to claim 16 , wherein the block copolymer and TPU have a similar refractive index.