Nova Patents
EP0857752A2

Rubber composition and pneumatic tire made by using the same

Abstract

The present invention provides a rubber composition comprising natural rubber and/or diene synthetic rubbers, silica in an amount of 10 to 85 parts by weight per 100 parts by weight of the rubber, a specific silane coupling agent, i.e., a bis(alkoxysilylalkyl) polysulfide having a polysulfide structure in which the distribution of sulfur is specified, in an amount of 1 to 20% by weight of the amount of silica, and a specific silica dispersion improver in an amount of 1 to 15% by weight of the amount of silica, and provides a pneumatic tire manufactured by using the rubber composition. The pneumatic tire has excellent low heat buildup property and abrasion resistance.

EP0857752A2, drawing sheet 1
Sheet 1 of 35

Term

Term ended

Projected expiry passed 26 August 2017, 9.1 years ago.

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18 claims: 1 independent, 17 dependent

  1. 1
    A rubber composition which comprises a rubber component comprising at least one member selected from the group consisting of natural rubber and diene synthetic rubbers; silica in an amount of 10 to 85 parts by weight per 100 parts by weight of the rubber component; in an amount of 1 to 20% by weight of the amount of silica, a silane coupling agent represented by following general formula (I):(C n H 2n+1 O) 3 Si-(CH 2 ) m -S y -(CH 2 ) m -Si(C n H 2n+1 O) 3      (I) wherein n represents an integer of 1 to 3, m represents an integer of 1 to 9, y represents a positive number of 1 or more which has a distribution, and the distribution of -S y - satisfies the relation: (S 1 +S 2 +S 3 +S 4 )/(S 5 +S 6 +S 7 +S 8 +S 9 ) ≥ 0.85;and, in an amount of 1 to 15% by weight of the amount of silica, at least one silica dispersion improver selected from the group consisting of: (1) hexamethyldisilazane, (2) silicone oils represented by general formula (II): (3) silicone oils modified with an alkoxy group or an amino group which are represented by general formula (III): wherein, in general formulae (II) and (III), R represents an alkyl group having 1 to 3 carbon atoms or a phenyl group, 1≤p+q≤200 , q/(p+q)≥0.15 , X 1 represents an alkoxy group having 1 to 3 carbon atoms or an amino group represented by -R 1 NR 2 R 3 or -R 1 NHR 4 NR 2 R 3 , wherein R 1 and R 4 each represents -(CH 2 ) n -, n represents 1, 2, or 3, and R 2 and R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 36 carbon atoms, or a phenyl group, (4) carbonyl compounds Containing nitrogen which are represented by general formulae (IV): wherein R a to R j each represents a hydrogen atom or a linear or branched saturated or unsaturated aliphatic, aromatic, or alicyclic hydrocarbon having 1 to 20 carbon atoms, and (5) amine compounds represented by general formula (V): wherein R p and R t each independently represents an alkyl or alkenyl group having 1 to 36 carbon atoms, a benzyl group, a cyclohexyl group, or one of these groups substituted with a hydroxyl group, and R k represents an alkyl, alkenyl, or alkoxy group having 1 to 36 carbon atoms or one of these groups substituted with a hydroxyl group, a benzyl group, a benzyl group substituted with an alkyl or alkenyl group having 4 to 36 carbon atoms, or a group represented by following general formulae (VI): wherein R 5 represents an alkyl or alkenyl group having 1 to 36 carbon atoms, R 6 represents an ethylene group or a propylene group, X 2 represents a hydrogen atom, an alkyl, alkenyl, alkyloyl, or alkenyloyl group having 1 to 18 carbon atoms, A represents an alkylene or hydroxyalkylene group having 2 to 6 carbon atoms, m represents an integer of 1 to 10, A may be the same or may differ from each other when m represents 2 or a number greater than 2, and n represents an integer of 1 to 10.
  2. 2
    A rubber composition according to Claim 1, wherein the amount of silica is 20 to 65 parts by weight per 100 parts by weight of the rubber component.
  3. 3
    A rubber composition according to Claim 1, wherein the amount of the silane coupling agent is 3 to 15% by weight of the amount of silica.
  4. 4
    A rubber composition according to Claim 1, wherein the amount of the silica dispersion improver is 2 to 15% by weight of the amount of silica.
  5. 5
    A rubber composition according to Claim 1, wherein the distribution of -S y - satisfies the relation:(S 1 +S 2 +S 3 )/(component(s) S having 4 or more sulfurs) ≥ 0.45 and the content of component S 3 is 20% or more.
  6. 6
    A rubber composition according to Claim 1, wherein the distribution of -S y - satisfies the relation:(S 1 +S 2 +S 3 )/(component(s) S having 4 or more sulfurs) ≥ 0.55 and the content of component S 3 is 30% or more.
  7. 7
    A rubber composition according to Claim 1, further comprising 80 parts by weight or less of carbon black as a reinforcing filler per 100 parts by weight of the rubber component.
  8. 8
    A rubber composition according to Claim 5, further comprising 80 parts by weight or less of carbon black as a reinforcing filler per 100 parts by weight of the rubber component.
  9. 9
    A rubber composition according to Claim 6, further comprising 80 parts by weight or less of carbon black as a reinforcing filler per 100 parts by weight of the rubber component.
  10. 10
    A rubber composition according to Claim 7, further comprising 20 to 60 parts by weight of carbon black as a reinforcing filler per 100 parts by weight of the rubber component.
  11. 11
    A rubber composition according to Claim 1, wherein anhydrous sodium sulfide (Na 2 S) and sulfur (S) are reacted with each other in a mol ratio in a range of 1:1 to 1:2.5 in an atmosphere of an inert gas in a polar solvent to obtain sodium polysulfide, the obtained sodium polysulfide is reacted in an atmosphere of an inert gas with a halogenoalkoxysilane represented by general formula (VII): wherein R 7 and R 8 each represents an alkyl group having 1 to 3 carbon atoms, R 9 represents a divalent hydrocarbon group having 1 to 9 carbon atoms, X 3 represents a halogen atom, and k represents an integer of 1 to 3, and the obtained compound is used as the silane coupling agent.
  12. 12
    A rubber composition according to Claim 5, wherein anhydrous sodium sulfide (Na 2 S) and sulfur (S) are reacted with each other in a mol ratio in a range of 1:1 to 1:2.5 in an atmosphere of an inert gas in a polar solvent to obtain sodium polysulfide, the obtained sodium polysulfide is reacted in an atmosphere of an inert gas with a halogenoalkoxysilane represented by general formula (VII) of Claim 11, and the obtained compound is used as the silane coupling agent.
  13. 13
    A rubber composition according to Claim 6, wherein anhydrous sodium sulfide (Na 2 S) and sulfur (S) are reacted with each other in a mol ratio in a range of 1:1 to 1:2.5 in an atmosphere of an inert gas in a polar solvent to obtain sodium polysulfide, the obtained sodium polysulfide is reacted in an atmosphere of an inert gas with a halogenoalkoxysilane represented by general formula (VII) of Claim 11, and the obtained compound is used as the silane coupling agent.
  14. 14
    A pneumatic tire which is manufactured by using the rubber composition described in Claim 1 for tread rubber.
  15. 15
    A pneumatic tire which is manufactured by using the rubber composition described in Claim 5 for tread rubber.
  16. 16
    A pneumatic tire which is manufactured by using the rubber composition described in Claim 6 for tread rubber.
  17. 17
    A pneumatic tire which is manufactured by using the rubber composition described in Claim 7 for tread rubber.
  18. 18
    A pneumatic tire which is manufactured by using the rubber composition described in Claim 11 for tread rubber.
Independent claims18