Cyclic diene-based copolymers

Patent metadata

Field	Value
Publication number	US-11732076-B2
Application number	US-202117301488-A
Country	US
Kind code	B2
Filing date	Apr 5, 2021
Priority date	Apr 6, 2020
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

Disclosed herein are copolymers formed by cationic polymerization of one or more cyclic dienes and a comonomer selected from the group consisting of a monoterpene, a branched styrene, and combinations thereof, in the presence of a catalyst. Random copolymers having repeat units derived from a cyclic conjugated diene, such as 1,3-cyclohexadiene, and a comonomer such as a monoterpene, can be prepared as soluble products in hydrocarbon solvents. The copolymers can be crosslinked with various crosslinking agents to form materials having good oxidative stability and fire retardancy. The uncrosslinked and crosslinked copolymers have useful properties such as a low dissipation factor, low dielectric constants, and a good balance of thermomechanical and electrical properties that make them valuable in electronic applications.

First claim

The invention claimed is:

1. A copolymer formed by cationic polymerization of one or more cyclic dienes, and a comonomer in the presence of a catalyst, wherein
the comonomer is selected from the group consisting of a monoterpene, a branched styrene, and combinations thereof;
the one or more cyclic dienes is selected from the group consisting of 1,3-cyclohexadiene (CHD), cyclopentadiene (CPD), 1,3-cycloheptadiene, 4,5,6,7-tetrahydroindene, norbornadiene (NBD), and combinations thereof;
the catalyst is selected from the group consisting of a Bronsted acid, a Lewis acid, and combinations thereof;
the copolymer has a Mn of 300-5,000 Dalton and a Mz of 2000-30,000 Dalton;
the copolymer has
(i) a solubility in a hydrocarbon solvent of 0.1 to 2 g of the copolymer per gram of the hydrocarbon solvent, and
(ii) a Tg of 80° C. to 180° C.

2. The copolymer of claim 1 , wherein the copolymer contains at least 0.1 wt. % of phenyl groups as measured by proton NMR.

3. The polymer of claim 1 , wherein the branched styrene comprises any of α-methylstyrene, 1,1-diphenylethylene, or combinations thereof.

4. The polymer of claim 1 , wherein the monoterpene is selected from the group consisting of α-pinene, β-pinene, limonene, myrcene, ocimene, α-phellandrene, β-phellandrene, farnesene, camphene, α-terpinene, sabinene, γ-terpinene, α-terpinene, 3-carene, and combinations thereof.

5. The copolymer of claim 1 , wherein the one or more cyclic dienes comprises a cyclic conjugated diene, and wherein the cyclic conjugated diene is 1,3-cyclohexadiene containing up to 10 wt. % of 1,4-cyclohexadiene, relative to the overall weight of cyclic conjugated diene.

6. The copolymer of claim 1 , wherein the one or more cyclic dienes comprises a cyclic conjugated diene, and wherein the cyclic conjugated diene comprises polymerized 1,4-addition units and polymerized 1,2-addition units in molar ratio from 90:10 to 10:80.

7. The copolymer of claim 1 , having a molar ratio of one or more cyclic dienes to comonomer ranging from 5:95 to 95:5.

8. The copolymer of claim 1 , wherein the catalyst is a Lewis catalyst, and wherein the Lewis acid catalyst comprises a Group 3-8 or Group 12-15 metal and one or more electron-withdrawing groups.

9. The copolymer of claim 1 , wherein the copolymer has a solubility in the hydrocarbon solvent ranging from 10 wt % to about 80 wt %, relative to the weight of the hydrocarbon solvent.

10. The copolymer of claim 1 , wherein the hydrocarbon solvent is selected from the group of aromatic hydrocarbons, alicyclic or aliphatic hydrocarbons, and combinations thereof.

11. The copolymer of claim 1 , wherein
the comonomer is selected from the group consisting of α-methylstyrene, 1,1-diphenylethylene, α-pinene, β-pinene, limonene, myrcene, ocimene, α-phellandrene, β-phellandrene, farnesene, camphene, α-terpinene, sabinene, γ-terpinene, α-terpinene, 3-carene, and combinations thereof;
the one or more cyclic dienes comprises a cyclic conjugated diene, and wherein the cyclic conjugated diene is 1,3-cyclohexadiene containing up to 10 wt. % of 1,4-cyclohexadiene, relative to the overall weight of cyclic conjugated diene;
the copolymer has 5-95 mol % of polymerized units derived from 1,3-cyclohexadiene, and 95-5 mol % of polymerized units derived from the comonomer;
the copolymer contains at least 0.1 wt. % of phenyl groups as measured by proton NMR.

12. A crosslinked polymer formed by reaction of the copolymer of claim 1 with a crosslinking agent selected from the group of sulfur-based agents, peroxide-based agents, tellurium, selenium, polysulfide polymers, metallic oxides, di-isocyanates, and combinations thereof.

13. The crosslinked polymer of claim 12 , having one or more of:
(i) a Tg of 140° C. to 250° C.,
(ii) a 180° peel strength to copper of 0.2 to 1.5 N/m 2 ,
(iii) a dissipation factor of 0.0025-0.0045 according to IPC TM-650 2.5.5.13,
(iv) a dielectric constant Dk of <4.5 according to IPC TM-650 2.5.5.13, and
(v) a fire retardancy, corresponding to the time taken for complete char formation, measured from sample ignition time, of less than or equal to 40 seconds.

14. A prepreg composition comprising the crosslinked polymer of claim 13 , a reinforcing material, and a rubber.

15. A method for forming a copolymer, the method comprising:
cationically polymerizing a monomer comprising one or more cyclic dienes and a comonomer in the presence of a catalyst and in a hydrocarbon solvent, forming the copolymer; and
recovering the copolymer;
wherein
the catalyst is selected from the group consisting of a Bronsted acid, a Lewis acid, and combinations thereof;
the comonomer is selected from the group consisting of a monoterpene, a branched styrene, and combinations thereof;
the one or more cyclic dienes is selected from the group consisting of 1,3-cyclohexadiene (CHD), cyclopentadiene (CPD), 1,3-cycloheptadiene, 4,5,6,7-tetrahydroindene, norbornadiene (NBD), and combinations thereof; and
wherein
the copolymer has a Mn of 300-5,000 Dalton and a Mz of 2000-30,000 Dalton;
the copolymer has
(i) a solubility in a hydrocarbon solvent of 0.1 to 2 g of the copolymer per gram of the hydrocarbon solvent, and
(ii) a Tg of 80° C. to 180° C.

16. The method of claim 15 , wherein the copolymer contains at least 0.1 wt. % of phenyl groups as measured by proton NMR.

17. The method of claim 15 , wherein the one or more cyclic dienes comprises a cyclic conjugated diene, and wherein the cyclic conjugated diene comprises polymerized 1,4-addition units and polymerized 1,2-addition units in molar ratio from 90:10 to 10:80.

18. The method of claim 15 , wherein the cationically polymerizing is at a reaction temperature of −100° C. to 120° C.

19. The method of claim 15 , wherein the catalyst is selected from the group consisting of AlCl 3 , TiCl 4 , SnCl 4 , B(C 6 F 5 ) 3 , BF 3 and complexes thereof with Lewis bases, methylalumoxane, metallocene halides and combinations thereof with methylalumoxane, and combinations thereof.

20. The method of claim 19 , further comprising crosslinking the recovered polymer with a crosslinking agent to provide a crosslinked copolymer, wherein the crosslinking agent is selected from the group of sulfur-based agents, peroxide-based agents, tellurium, selenium, polysulfide polymers, metallic oxides, di-isocyanates, and combinations thereof.

Assignees

• Kraton Polymers Llc
• Kraton Corp

Inventors

• Ding Ruidong
• Tian Jason
• Van Erp Hannes Hendrik Peter
• Reiter Chad

Classifications

• C08F236/045 Primary

  conjugated hydrocarbons other than butadiene or isoprene · CPC title

• C08F132/06

  having two or more carbon-to-carbon double bonds · CPC title

• C08F136/045

  conjugated hydrocarbons other than butadiene or isoprene · CPC title

• C08F232/04

  having one carbon-to-carbon double bond · CPC title

• C08J5/244

  using glass fibres · CPC title