Preparation of bimodal rubber, thermoplastic vulcanizates, and articles made therefrom

Patent metadata

Field	Value
Publication number	US-11466149-B2
Application number	US-201916460260-A
Country	US
Kind code	B2
Filing date	Jul 2, 2019
Priority date	Jul 23, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

Pellet-stable olefinic copolymer bimodal rubber is made using parallel reactors, with one reactor synthesizing higher molecular weight (MW) rubber with dual catalysts, with an improved molecular weight split ratio and an improved composition distribution of the moderate and ultra-high MW components, while another reactor synthesizes random isotactic polypropylene copolymer (RCP). The effluents are reactor-blended and result in pellet-stable bimodal rubber (P-SBR), which may be pelletized. When making thermoplastic vulcanizates (TPVs) with P-SBR, the need to granulate rubber bales and subsequently use talc, clay, or other anti-agglomeration agents to prevent granulated rubber crumbs from agglomerating are eliminated. TPVs made with P-SBR have vulcanized rubber particles that are smaller and more uniform in size, resulting in TPVs with higher particle counts and more thermoplastic “ligaments” between the particles, with such ligaments being made stronger by the added RCP. Such thus-produced TPVs have a lower hysteresis and flexural modulus, and better elastic properties.

First claim

What is claimed is:

1. A method of preparing a pellet-stable olefinic copolymer bimodal rubber, comprising:
producing a high molecular weight olefinic copolymer rubber with a weight average molecular weight (Mw) of greater than 500,000 g/mol and characterized by a bimodal molecular weight and a bimodal composition distribution (“bimodal rubber”) within a first reactor;
concurrently producing isotactic polypropylene random copolymer (RCP) within a second reactor, wherein the first and second reactors are operated in parallel to each other;
obtaining an effluent from the first reactor;
obtaining an effluent from the second reactor;
reactor-blending the effluents in situ to thereby produce a cross-linkable pellet-stable RCP-containing bimodal rubber (“pellet-stable bimodal rubber”), wherein about 80-97.5 wt % of the bimodal rubber is blended with about 2.5-20 wt % of the RCP, and optionally pelletizing—the pellet-stable bimodal rubber.

2. The method of claim 1 , further comprising producing the RCP by contacting, at a temperature of 80° C. or more, propylene and an optional comonomer with a homogeneous catalyst system comprising a non-coordinating anion activator and one or more metallocene catalyst compound represented by the formula:

wherein:
R 2 and R 8 are, independently, a C 1 to C 20 linear alkyl group;
R 4 and R 10 are substituted or unsubstituted aryl groups, provided that at least one of the aryl groups is: 1) substituted at an othro-position with at least one group selected from C 1 to C 40 hydrocarbyls, heteroatoms, and heteroatom containing groups, 2) substituted at the 3′, 4′ or 5′-position with at least one group selected from C 1 to C 40 hydrocarbyls, heteroatoms, and heteroatom containing groups, or a combination thereof;
M is a group transition 2, 3 or 4 metal;
T is a bridging group;
each X is an anionic leaving group;
each R 1 , R 3 , R 5 , R 6 , R 7 , R 9 , R 11 , R 12 , R 13 , and R 14 is, independently, hydrogen, or a hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, silylcarbyl, substituted silylcarbyl, germylcarbyl, or substituted germylcarbyl substituents; and
recovering a reactor effluent.

3. The method of claim 2 , wherein the one or more metallocene catalyst compound further comprises one or more of:
R 2 is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl or n-decyl;
R 8 is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl or n-decyl;
at least one of R 4 and R 10 is a phenyl group substituted at the 3′ and 5′-positions with C 1 to a C 10 alkyl groups or aryl groups or combinations thereof;
R 4 and R 10 are independently a phenyl group substituted at the 3′ and 5′-positions with C 1 to a C 10 alkyl groups or aryl groups or combinations thereof;
R 4 and R 10 are independently a phenyl group substituted at the 3′ and 5′-positions with C 1 to a C 10 alkyl groups or aryl groups or combinations thereof, the 4′-position is substituted with a group selected from (XR′ n ), wherein X is a Group 14-17 heteroatom having an atomic weight of 13 to 79 and R′ is one of a hydrogen atom, halogen atom, a C 1 -C 10 alkyl group, or a C 6 -C 10 aryl group and n is 0, 1, 2, or 3;
M is Hf, Ti and/or Zr;
at least one of R 4 and R 10 is a phenyl group substituted at the 2′-position with an alkyl or aryl group;
wherein one of R 5 and R 6 or R 11 and R 12 join together to form a ring structure;
wherein T is represented by the formula R 2 a J, where J is C, Si, or Ge, and each R a is, independently, hydrogen, halogen, C 1 to C 20 hydrocarbyl or a C 1 to C 20 substituted hydrocarbyl, and two R a can form a cyclic structure including aromatic, partially saturated, or saturated cyclic or fused ring system; and
wherein T is CH 2 , CH 2 CH 2 , C(CH 3 ) 2 , SiMe 2 , SiPh 2 , SiMePh, Si(CH 2 ) 3 , Si(CH 2 ) 4 , Si(Me 3 SiPh) 2 , or Si(CH 2 ) 5 .

4. The method of claim 1 , further comprising producing the RCP by using a metallocene catalyst compound represented by one or more of the following formulas:

5. The method of claim 1 , further comprising producing the bimodal rubber by using a transition metal pyridyldiamide catalyst component represented by formula (III):

wherein:
each of R 12 , R 13 , R 14 , R 15 , and R 16 is independently hydrogen, methyl, ethyl, propyl, isopropyl, isobutyl, or tertbutyl; and
each of X 1 and X 2 is independently halogen or alkyl.

6. The method of claim 1 , further comprising producing the bimodal rubber by using transition metal pyridyldiamides from a catalyst system including one or more of (1) to (8) below:

7. The method of claim 1 , further comprising producing the bimodal rubber by using a bridged biscyclopentadienyl compound represented by the formula:

wherein:
M is zirconium or hafnium;
each of Cp 1 and Cp 1 is independently a substituted or unsubstituted cyclopentadienyl-containing group;
T is a Group 14 element containing bridging group;
each of Y 1 and Y 2 is independently an anionic leaving group;
each of Q 1 and Q 2 is independently a substituted or unsubstituted hydrocarbyl group; and
each of Ar 1 and Ar 2 is independently a substituted or unsubstituted aryl group.

8. The method of claim 7 , further comprising producing the bimodal rubber, wherein Ar 1 and Ar 2 may be independently:

wherein each of R 30 , R 31 , R 32 , R 33 , and R 34 may be independently hydrogen, linear or branched C 1 -C 40 hydrocarbyl, linear or branched substituted C 1 -C 40 hydrocarbyl, silylcarbyl, substituted silylcarbyl, C 6 -C 10 aryl, substituted C 6 -C 10 aryl, —NR′ 2 , —SR′, —OR′, —OSiR′ 3 , —PR′ 2 , where each R′ is hydrogen, halogen, C 1 -C 10 alkyl, or phenyl;
Q 1 and Q 2 may be independently hydrogen, linear or branched C 1 -C 40 hydrocarbyl, linear or branched substituted C 1 -C 40 hydrocarbyl, silylcarbyl, substituted silylcarbyl, C 6 -C 10 aryl, substituted C 6 -C 10 aryl, —NR′ 2 , —SR′, —OR′, —OSiR′ 3 , —PR′ 2 , where each R′ is hydrogen, halogen, C 1 -C 10 alkyl, or phenyl;
each of Cp 1 and Cp 2 may be independently unsubstituted cyclopentadienyl, substituted cyclopentadienyl, unsubstituted indenyl, substituted indenyl, unsubstituted fluorenyl, or substituted fluorenyl; and
wherein Y 1 and Y 2 may be independently hydrogen, halide, hydroxyl, or C 1 -C 50 substituted or unsubstituted hydrocarbyl, amide, alkoxide, sulfide, phosphide, halide, or a combination thereof, or Y 1 and Y 2 are joined together to form a metallocycle ring, or Y 1 and Y 2 are joined to form a chelating ligand, or an alkylidene.

9. The method of claim 1 , further comprising making the bimodal rubber by cont

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Tsou Andy H
• Hagadorn John R
• Yang Jian
• Walker Ron
• Datta Sudhin

Classifications

• C08F210/18

  with non-conjugated dienes, e.g. EPT rubbers · CPC title

• B29B7/46

  with more than one shaft · CPC title

• C08J2323/12

  Polypropene · CPC title

• B29B7/7495

  for mixing rubber · CPC title

• B29B7/42

  with screw or helix · CPC title