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EP-3670551-B1 - COPOLYMER, RUBBER COMPOSITION, RUBBER COMPOSITION FOR TIRE SIDE USE, CROSSLINKED RUBBER COMPOSITION AND TIRE

EP3670551B1EP 3670551 B1EP3670551 B1EP 3670551B1EP-3670551-B1

Inventors

  • HORIKAWA, YASUO
  • KAITA, SHOJIRO
  • TARDIF, OLIVIER
  • MATSUSHITA, JUNKO

Dates

Publication Date
20260513
Application Date
20120202

Claims (19)

  1. A rubber composition comprising: a copolymer of a conjugated diene compound and a non-conjugated olefin, wherein the content of 1,2 adduct units (including 3,4 adduct units) of a unit derived from the conjugated diene compound is 5 % or less, and the non-conjugated olefin is at least one selected from the group consisting of ethylene, propylene, and 1-butene; and a conjugated diene-based polymer, wherein the conjugated diene-based polymer means a polymer that does not contain a non-conjugated olefin as a monomer unit component, the content of 1,2 adduct units (including 3,4 adduct units) is determined through 1 H-NMR spectroscopy, and a mass ratio of the copolymer of a conjugated diene compound and a non-conjugated olefin to the conjugated diene-based polymer is 10/90 to 90/10.
  2. The rubber composition according to claim 1, wherein the unit derived from the conjugated diene compound has a cis-1,4 bond content of more than 50 mol%, and the cis-1,4 bond content is determined through 13 C-NMR spectroscopy.
  3. The rubber composition according to claim 1, wherein the content of a unit derived from the non-conjugated olefin is greater than 0 mol% and not more than 50 mol%.
  4. The rubber composition according to claim 1, wherein the copolymer has a polystyrene-equivalent average-weight molecular weight of 10,000 to 10,000,000, and the polystyrene weight-average molecular weight is determined through gel permeation chromatography using monodisperse polystyrene as a reference.
  5. The rubber composition according to claim 1, wherein the non-conjugated olefin is ethylene.
  6. The rubber composition according to claim 1, wherein the conjugated diene compound is at least one selected from the group consisting of 1,3-butadiene and isoprene.
  7. The rubber composition according to claim 1, wherein the content of 1,2 adduct units (including 3,4 adduct units) of a unit derived from the conjugated diene compound is 3% or less.
  8. The rubber composition according to claim 7, wherein the content of 1,2 adduct units (including 3,4 adduct units) of a unit derived from the conjugated diene compound is 2% or less.
  9. The rubber composition according to claim 1 further comprising carbon black, wherein the carbon black has a nitrogen adsorption specific surface area (N 2 SA) of 20 m 2 /g to 100 m 2 /g, and the nitrogen adsorption surface area (N 2 SA) is determined in accordance with JIS K6217-2:2001.
  10. The rubber composition according to claim 9, wherein the content of the carbon black is 10 parts by mass to 70 parts by mass per 100 parts by mass of the rubber component.
  11. The rubber composition according to claim 1, wherein the conjugated diene-based polymer is natural rubber.
  12. The rubber composition according to claim 11, wherein the content of the natural rubber per 100 parts by mass of the rubber component is at least 10 parts by mass.
  13. The rubber composition according to claim 1 further comprising a crosslinking agent by 0.1 parts by mass to 20 parts by mass per 100 parts by mass of the rubber component.
  14. The rubber composition according to claim 1, wherein the content of the conjugated diene compound/non-conjugated olefin copolymer per 100 parts by mass of the rubber component is 25 parts by mass to 75 parts by mass.
  15. The rubber composition according to claim 1, wherein the content of the conjugated diene-based polymer per 100 parts by mass of the rubber component is 75 parts by mass to 25 parts by mass.
  16. The rubber composition according to claim 9, wherein the carbon black has a nitrogen adsorption specific surface area (N 2 SA) of 35 m 2 /g to 80 m 2 /g.
  17. A crosslinked rubber composition obtained by crosslinking the rubber composition according to claim 1.
  18. A tire manufactured by using the rubber composition according to claim 1 or the crosslinked rubber composition according to claim 17.
  19. A tire according to claim 18, wherein the crosslinked rubber composition is applied to at least one selected from the group consisting of a tread, a base tread, a sidewall, a side reinforcing rubber, and a bead filler.

Description

The present application is a divisional application of European patent application no. 12742203.8. TECHNICAL FIELD The present invention relates to a rubber composition comprising a copolymer of a conjugated diene compound and a non-conjugated olefin (a conjugated diene compound/non-conjugated olefin copolymer), a rubber composition for tire side use, a crosslinked rubber composition and a tire, and in particular, to a rubber composition comprising a copolymer of a conjugated diene compound and a non-conjugated olefin used for manufacturing a rubber with low heat generation properties and excellent in heat resistance, ozone resistance (weather resistance) as well as crack growth resistance, a rubber composition for tire side use using the rubber composition for tire sidewall members, a crosslinked rubber composition obtained by crosslinking the rubber composition, and a tire using the rubber composition or the crosslinked rubber composition. BACKGROUND ART At least two different monomers can be polymerized in the same polymerization system so as to generate a copolymer having those different monomer units arranged as repeating units in one polymer chain. However, no report has been made on the content of 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound unit in a copolymer obtained by polymerization reaction of a conjugated diene compound and a non-conjugated olefin (the content of 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound in a unit derived from the conjugated diene compound). For example, JP 2000-154210 A (PTL 1) discloses a catalyst for polymerizing conjugated dienes that contains a transition metal compound of group IV of the periodic table having a cyclopentadiene ring structure. PTL 1 discloses α-olefins such as ethylene as monomers which can be copolymerized with a conjugated diene. PTL 1, however, does not at all refer to the content of 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound unit in a copolymer, and there is no teaching or suggestion that a rubber composition with low heat generation properties and excellent in heat resistance and ozone resistance (weather resistance) may be obtained by controlling the content of 1,2 adduct units (including 3,4 adduct units) to be 5 % or less. In addition, JP 2006-249442 A (PTL 2) discloses a catalyst for polymerizing olefins that is composed of a transition metal compound such as a titanium compound and a co-catalyst. PTL 2 also discloses a copolymer of an α-olefin and a conjugated diene compound. PTL 2, however, does not at all refer to the content of 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound unit in the copolymer, and there is no teaching or suggestion that a rubber composition with low heat generation properties and excellent in heat resistance and ozone resistance (weather resistance) may be obtained by controlling the content of 1,2 adduct units (including 3,4 adduct units) to be 5 % or less. Further, JP 2006-503141 A (PTL 3) discloses a copolymer of ethylene and butadiene that is obtained by synthesizing ethylene and butadiene as a starting material by means of a special organic metal complex as a catalytic component. However, PTL 3 merely refers to the fact that butadiene, a monomer, is inserted into the copolymer in the form of transformer-1,2-cyclohexane and does not at all refer to the content of 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound unit in the copolymer. There is no teaching or suggestion that a rubber composition with low heat generation properties and excellent in heat resistance and ozone resistance (weather resistance) may be obtained by controlling the content of 1,2 adduct units (including 3,4 adduct units) to be 5 % or less. In addition, JP 11-228743 A (PTL 4) discloses an olefin-rich, olefin-diene copolymer. PTL 4 discloses an unsaturated elastomer composition that is composed of an unsaturated olefin-based copolymer and rubber and used for obtaining a vulcanizate excellent in heat resistance and so on. PTL 4 also refers to a ratio of the double bonds in the side chain derived from 1,2 adduct units (including 3,4 adduct units) to the double bonds in the main chain derived from 1,4 adduct units. PTL 4, however, fails to provide any teaching or suggestion of the cis content and vinyl content of the olefin-diene copolymer, or the use of a copolymer containing 1,2 adduct units (including 3,4 adduct units) of the conjugated diene compound unit in an amount of 5 % or less. Moreover, PTL 4 does not provide any teaching or suggestion that a rubber composition with low heat generation properties and excellent in heat resistance and ozone resistance (weather resistance) may be obtained by controlling the content of 1,2 adduct units (including 3,4 adduct units) to be the content 5 % or less. In addition, JP 2000-086857 A (PTL 5) discloses a butadiene polymer that has a vinyl c