Claims
- 1. A method for preparing a block copolymer, said method comprising polymerizing under polymerization conditions by sequentially charging at least one monovinylarene monomer, an organomono alkali metal initiator, and at least one conjugated diene monomer, thereafter coupling with a polyfunctional coupling agent; and recovering said block copolymer;
- wherein the step of polymerizing is conducted using a charge sequence of the following charges in the following order:
- (a) a monovinylarene monomer and initiator;
- (b) initiator and a monovinylarene monomer;
- (c) a mixture of monovinylarene monomer and conjugated diene monomer; and
- (d) a monovinylarene monomer;
- wherein steps (a)-(b) are the only monomer and initiator charges used in the process;
- wherein said at least one monovinylarene monomer contains from about 8 to about 18 carbon atoms and is provided in at least three monovinylarene charges; and
- wherein said at least one conjugated diene monomer contains from about 4 to about 12 carbon atoms and is provided in at least one conjugated diene monomer charge.
- 2. A method for preparing a block copolymer, said method comprising polymerizing under polymerization conditions by sequentially charging at least one monovinylarene monomer, an organoalkali metal initiator, and at least one conjugated diene monomer, thereafter coupling with a polyfunctional coupling agent; and recovering said block copolymer;
- wherein the step of polymerizing is conducted using a charge sequence of the following charges in the following order:
- (a) a monovinylarene monomer and initiator;
- (b) initiator and a monovinylarene monomer;
- (c) a mixture of monovinylarene monomer and conjugated diene monomer;
- (d) a monovinylarene monomer and initiator; and
- (e) a mixture of monovinylarene monomer and conjugated diene monomer;
- wherein steps (a)-(e) are the only monomer and initiator charges used in the process;
- wherein said at least one monovinylarene monomer contains from about 8 to about 18 carbon atoms and is provided in at least three monovinylarene charges; and
- wherein said at least one conjugated diene monomer contains from about 4 to about 12 carbon atoms and is provided in at least one conjugated diene monomer charge.
- 3. A method according to claim 1 wherein said monomers are added in an amount in the range of about 55 to about 95 weight percent monovinylarene monomer and about 5 to about 45 weight percent conjugated diene monomer.
- 4. A method according to claim 3 wherein said monomers are added in an amount in the range of about 60 to about 95 weight percent monovinylarene monomer and about 5 to about 40 weight percent conjugated diene monomer.
- 5. A method according to claim 4 wherein said monomers are added in an amount in the range of about 80 to about 95 weight percent monovinylarene monomer and about 5 to about 20 weight percent conjugated diene monomer.
- 6. A method according to claim 1 wherein the first monovinylarene monomer charge contains monovinylarene monomer in an amount in the range of from about 30 weight percent to about 50 weight percent based on the total weight of the final block copolymer.
- 7. A method according to claim 6 wherein the second monovinylarene monomer charge contains monovinylarene monomer in an amount in the range of from about 15 weight percent to about 30 weight percent based on the total weight of the final block copolymer.
- 8. A method according to claim 7 wherein the third monovinylarene monomer charge contains monovinylarene monomer in the range of from about 5 weight percent to about 30 weight percent based on the total weight of the final block copolymer.
- 9. A method according to claim 8 wherein said conjugated diene monomer is 1,3-butadiene and said monovinylarene monomer is styrene.
- 10. A monovinylarene/conjugated diene block copolymer consisting essentially
- about 55 to about 95 weight percent polymerized monovinylarene based on total weight of said copolymer and about 5 to about 45 weight percent polymerized conjugated diene based on total weight of said copolymer;
- wherein said copolymer results from coupling block copolymer chains
- S.sub.1 -S.sub.2 -B.sub.1 /S.sub.3 -S.sub.4 -Li.sub.1
- S.sub.2 -B.sub.1 /S.sub.3 -S.sub.4 -Li.sub.2
- wherein
- S=monovinylarene block
- B/S=tapered block of conjugated diene/monovinylarene
- Li=living polymer site or coupling site where subscripts 1 and 2 refer to the imitator charge sequence and said block copolymer chains are the only block copolymer chains present during the coupling.
- 11. A monovinylarene/conjugated diene block copolymer consisting essentially of;
- about 55 to about 95 weight percent polymerized monovinylarene based on total weight of said copolymer and about 5 to about 45 weight percent polymerized conjugated diene based on total weight of said copolymer;
- wherein said copolymer results from coupling block copolymer chains
- S.sub.1 -S.sub.2 -B.sub.1 /S.sub.3 -S.sub.4 -B.sub.2 /S.sub.5 -Li.sub.1
- S.sub.2 -B.sub.1 /S.sub.3 -S.sub.4 -B.sub.2 /S.sub.5 -Li.sub.2
- S.sub.4 -B.sub.2 /S.sub.5 -Li.sub.3
- wherein
- S=monovinylarene block
- B/S=tapered block of conjugated diene/monovinylarene
- Li=living polymer site or coupling site where subscripts 1, 2 and 3 refer to the initiator charge sequence.
- 12. A method according to claim 2 wherein said monomers are added in an amount in the range of about 55 to about 95 weight percent monovinylarene monomer and about 5 to about 45 weight percent conjugated diene monomer.
- 13. A method according to claim 12 wherein said monomers are added in an amount in the range of about 60 to about 95 weight percent monovinylarene monomer and about 5 to about 40 weight percent conjugated diene monomer.
- 14. A method according to claim 13 wherein said monomers are added in an amount in the range of about 80 to about 95 weight percent monovinylarene monomer and about 5 to about 20 weight percent conjugated diene monomer.
- 15. A method according to claim 2 wherein the first monovinylarene monomer charge contains monovinylarene monomer in an amount in the range of from about 30 weight percent to about 50 weight percent based on the total weight of the final block polymer.
- 16. A method according to claim 15 wherein the second monovinylarene monomer charge contains monovinylarene monomer in an amount in the range of from about 15 weight percent to about 30 weight percent based on the total weight of the final block polymer.
- 17. A method according to claim 16 wherein the third monovinylarene monomer charge contains monovinylarene monomer in an amount in the range of from about 5 weight percent to about 30 weight percent based on the total weight of the final block polymer.
- 18. A method according to claim 17 wherein said conjugated diene monomer is 1,3-butadiene and said monovinylarene monomer is styrene.
Parent Case Info
This application is a continuation of application Ser. No. 08/424,020, filed Apr. 18, 1995, now abandoned, which is a division of application Ser. No. 08/308,240, filed Sep. 19. 1994, now U.S. Pat. No. 5,436,298, which is a continuation-in-part of application Ser. No. 08/130,039, filed Sep. 30, 1993, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5130377 |
Trepka et al. |
Jul 1992 |
|
5290875 |
Moczygemba et al. |
Mar 1994 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
308240 |
Sep 1994 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
424020 |
Apr 1995 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
130039 |
Sep 1993 |
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