STYRENE-BUTADIENE BLOCK COPOLYMERS FOR TUBING APPLICATIONS

1 . A conjugated diene monovinylarene block copolymer comprising from about 35 phm to about 75 phm monovinylarene monomer, and comprising polymer chains containing a block structure having formula I:

S 1 —(S/B) 1 —(S/B) 2   (I); wherein:

S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from about 10 phm to about 45 phm of the copolymer;

(S/B) 1 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from about 30 wt. % to about 80 wt. %, based on the total weight of (S/B) 1 ; and

(S/B) 2 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the conjugated diene monomer content is from about 70 wt. % to about 99 wt. %, based on the total weight of (S/B) 2 ; and

wherein a kink resistance of tubing produced from the copolymer and tested in accordance with DIN EN 13868 is less than or equal to about 32 mm.

2 . The copolymer of claim 1 , wherein S 1 is in a range from about 20 phm to about 40 phm.

3 . The copolymer of claim 1 , wherein the monovinylarene monomer content in (S/B) 1 is in a range from about 35 wt. % to about 65 wt. %, based on (S/B) 1 .

4 . The copolymer of claim 1 , wherein the conjugated diene monomer content in (S/B) 2 is in a range from about 70 wt. % to about 85 wt. %, based on (S/B) 2 .

5 . The copolymer of claim 1 , wherein the copolymer comprises monovinylarene monomer in a range from about 58 phm to about 68 phm.

6 . The copolymer of claim 1 , wherein:

the monovinylarene monomer is styrene;

the conjugated diene monomer is a butadiene; and

the kink resistance is in a range from about 10 to about 24 mm.

7 . The copolymer of claim 1 , wherein:

the monovinylarene monomer is from about 57 phm to about 67 phm of the copolymer;

S 1 is from about 25 phm to about 38 phm of the copolymer;

the monovinylarene monomer content is from about 40 wt. % to about 60 wt. % of (S/B) 1 ; and

the conjugated diene monomer content is from about 72 wt. % to about 90 wt. % of (S/B) 2 .

8 . The copolymer of claim 7 , wherein the conjugated diene monovinylarene block copolymer is a styrene butadiene block copolymer.

9 . The copolymer of claim 1 , wherein S 1 is two or more monoblocks of the monovinylarene monomer.

10 . The copolymer of claim 1 , wherein the copolymer further comprises polymer chains containing a block structure having formula II:

S 2 —(S/B) 1 —(S/B) 2   (II); wherein:

S 2 is a monoblock of the monovinylarene monomer, wherein S 2 is from about 5 phm to about 30 phm of the copolymer.

11 . The copolymer of claim 10 , wherein S 2 is in a range from about 12 phm to about 25 phm.

12 . The copolymer of claim 10 , wherein the copolymer further comprises polymer chains containing a block structure having formula IA and/or IIA:

S 1 —(S/B) 1 —(S/B) 2 —S T1   (IA)

S 2 —(S/B) 1 —(S/B) 2 —S T2   (IIA); wherein:

S T1 and S T2 independently are monoblocks of the monovinylarene monomer, wherein S T1 and S T2 independently are from about 0.5 phm to about 5 phm of the copolymer.

13 . The copolymer of claim 1 , wherein (S/B) 1 is two mixed blocks of the conjugated diene monomer and the monovinylarene monomer having formula III:

—(S/B) 1A —(S/B) 1B —  (III); wherein:

the monovinylarene monomer content is from about 30 wt. % to about 80 wt. % of (S/B) 1A , and the monovinylarene monomer content is from about 30 wt. % to about 80 wt. % of (S/B) 1B .

14 . The copolymer of claim 13 , wherein the monovinylarene monomer content, independently, is from about 35 wt. % to about 65 wt. %, based on (S/B) 1A , and from about 35 wt. % to about 65 wt. %, based on (S/B) 1B .

15 . The copolymer of claim 1 , wherein the copolymer has:

a melt flow rate in a range from about 3 to about 20;

a kink resistance in a range from about 9 mm to about 20 mm; and

a Shore A hardness in a range from about 50 to about 90.

16 . The copolymer of claim 15 , wherein the copolymer has:

a pellet blocking force of less than or equal to about 120 lb f ; and

a re-kink resistance in a range from about 10 mm to about 30 mm.

17 . The copolymer of claim 1 , wherein the copolymer has:

a melt flow rate in a range from about 4 to about 18;

a kink resistance in a range from about 10 mm to about 24 mm; and

a Shore A hardness in a range from about 60 to about 80.

18 . An article of manufacture comprising the copolymer of claim 1

19 . A tubing product comprising the copolymer of claim 1 .

20 . A composition comprising:

(a) a conjugated diene monovinylarene block copolymer; and

(b) a second polymer;

wherein the conjugated diene monovinylarene block copolymer comprises from about 35 phm to about 75 phm monovinylarene monomer, and comprises polymer chains containing a block structure having formula I:

S 1 —(S/B) 1 —(S/B) 2   (I); wherein:

S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from about 10 phm to about 45 phm of the copolymer;

(S/B) 1 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from about 30 wt. % to about 80 wt. %, based on the total weight of (S/B) 1 ; and

(S/B) 2 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the conjugated diene monomer content is from about 70 wt. % to about 99 wt. %, based on the total weight of (S/B) 2 ; and

wherein a kink resistance of tubing produced from the copolymer and tested in accordance with DIN EN 13868 is less than or equal to about 32 mm.

21 . The composition of claim 20 , wherein the second polymer comprises a styrene butadiene polymer, a polystyrene polymer, or a combination thereof.

22 . The composition of claim 20 , wherein the composition further comprises an additive.

23 . The composition of claim 20 , wherein a kink resistance of tubing produced from the composition and tested in accordance with DIN EN 13868 is from about 10 to about 28 mm.

24 . A tubing product comprising the composition of claim 23 .

25 . A process to produce a conjugated diene monovinylarene block copolymer comprising from about 35 phm to about 75 phm monovinylarene monomer, and comprising polymer chains containing a block structure having formula I:

S 1 —(S/B) 1 —(S/B) 2   (I); wherein:

S 1 is a monoblock of the monovinylarene monomer, wherein S 1 is from about 10 phm to about 45 phm of the copolymer;

(S/B) 1 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the monovinylarene monomer content is from about 30 wt. % to about 80 wt. %, based on the total weight of (S/B) 1 ; and

(S/B) 2 is a mixed block of the conjugated diene monomer and the monovinylarene monomer, wherein the conjugated diene monomer content is from about 70 wt. % to about 99 wt. %, based on the total weight of (S/B) 2 ; and

wherein a kink resistance of tubing produced from the copolymer and tested in accordance with DIN EN 13868 is less than or equal to about 32 mm;

the process comprising contacting:

(i) a first initiator charge and a first charge of the monovinylarene monomer and allowing polymerization to occur until minimal free monomer is present; thereafter contacting all products of step (i) with

(ii) a second initiator charge and a second charge of the monovinylarene monomer and allowing polymerization to occur until minimal free monomer is present; thereafter contacting all products of step (ii) with

(iii) a first mixture of the monovinylarene monomer and the conjugated diene monomer and allowing polymerization to occur until minimal free monomer is present; thereafter contacting all products of step (iii) with

(iv) a second mixture of the monovinylarene monomer and the conjugated diene monomer and allowing polymerization to occur until minimal free monomer is present; thereafter contacting all products of step (iv) with

(v) a third mixture of the monovinylarene monomer and the conjugated diene monomer and allowing polymerization to occur until minimal free monomer is present; thereafter contacting all products of step (v) with

(vi) a coupling agent.

26 . The process of claim 25 , wherein at least one step in the process comprises polymerization in the presence of a modifier.

27 . The process of claim 25 , wherein an additional initiator is used in at least one of steps (iii) to (v).