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US-12617878-B2 - Sulfur-containing unsaturated hydrocarbon polymer and method for production thereof, additive for rubber, rubber composition, and tire

US12617878B2US 12617878 B2US12617878 B2US 12617878B2US-12617878-B2

Abstract

Provided is a sulfur-containing unsaturated hydrocarbon polymer which can improve wet grip performance and fuel efficiency of a tire in a well-balanced manner by being blended into a rubber composition for a tire. A sulfur-containing unsaturated hydrocarbon polymer of the present invention is a reaction product obtained by reacting sulfur with an unsaturated bond in a polymer of an unsaturated hydrocarbon.

Inventors

  • Keisuke Chino
  • Yusuke MATSUO
  • Makoto Ashiura

Assignees

  • ENEOS CORPORATION

Dates

Publication Date
20260505
Application Date
20200820
Priority Date
20190822

Claims (14)

  1. 1 . A method for producing a rubber composition comprising a step of combining a sulfur-containing unsaturated hydrocarbon polymer and a rubber component and a step of kneading the sulfur-containing unsaturated hydrocarbon polymer and the rubber component, wherein the sulfur-containing unsaturated hydrocarbon polymer is a reaction product obtained by reacting sulfur with an unsaturated bond of a polymer of an unsaturated hydrocarbon, the reaction product is composed only of sulfur and the polymer of the unsaturated hydrocarbon, the polymer of the unsaturated hydrocarbon is a petroleum resin comprising a norbornene skeleton, and the amount of sulfur reacted with the petroleum resin is 0.3 to 5 equivalent per unsaturated bond of the petroleum resin.
  2. 2 . The method of claim 1 , wherein the unsaturated hydrocarbon comprises a dicyclopentadiene.
  3. 3 . The method of claim 2 , wherein the petroleum resin is a DCPD/C9 resin.
  4. 4 . The method of claim 3 , wherein the rubber component comprises a diene rubber.
  5. 5 . The method of claim 1 , wherein the petroleum resin is a DCPD/C9 resin.
  6. 6 . The method of claim 5 , wherein the rubber component comprises a diene rubber.
  7. 7 . The method of claim 1 , wherein the rubber component comprises a diene rubber.
  8. 8 . A tire produced with the rubber composition obtained by the method of claim 1 .
  9. 9 . A tire produced with the rubber composition obtained by the method of claim 2 .
  10. 10 . A tire produced with the rubber composition obtained by the method of claim 3 .
  11. 11 . A tire produced with the rubber composition obtained by the method of claim 4 .
  12. 12 . A tire produced with the rubber composition obtained by the method of claim 5 .
  13. 13 . A tire produced with the rubber composition obtained by the method of claim 6 .
  14. 14 . A tire produced with the rubber composition obtained by the method of claim 7 .

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a sulfur-containing unsaturated hydrocarbon polymer and a method for producing the same. The present invention also relates to an additive for rubber comprising the sulfur-containing unsaturated hydrocarbon polymer, a rubber composition comprising the additive for rubber, and a tire produced using the rubber composition. Background Art Conventionally, tires have been manufactured using a vulcanized rubber in which a vulcanizing agent such as sulfur is added to a rubber component as a raw material. For example, when insoluble sulfur is used as a vulcanizing agent, it is possible to suppress blooming in which insoluble sulfur migrates to the rubber surface and precipitates in the vulcanization step. However, on the other hand, affinity with the rubber is low and dispersibility is poor. To solve such problem, it has been proposed to use a vulcanizing agent composition comprising insoluble sulfur and a dicyclopentadiene resin (see Patent Document 1). It has also been proposed to use a reaction product of sulfur and dicyclopentadiene alone as a vulcanizing agent (see Patent Document 2). Further, in recent years, regulations on exhaust gas such as carbon dioxide have become severe and demands for fuel efficiency improvement for automobiles have extremely increased from the viewpoints of resource conservation, energy saving, and environmental protection. Therefore, it is required to improve fuel efficiency by improving the rolling resistance of the tires. It is also required to improve the grip performance (wet grip performance) of the tires when the road surface is wet. However, the vulcanizing agent compositions described in Patent Documents 1 and 2 do not improve the performance of these tires. Therefore, there is a need for an additive capable of improving the performance of these tires. PRIOR ART DOCUMENTS Patent Documents [Patent Document 1] WO2018/189878[Patent Document 2] Japanese Patent Application Laid-Open Publication No. S62-84133 SUMMARY OF THE INVENTION Problems to be Solved by the Invention The present inventors have conducted intensive studies in order to solve the above problems and as a result have developed a sulfur-containing unsaturated hydrocarbon polymer which is a reaction product obtained by reacting sulfur with an unsaturated bond of a polymer of an unsaturated hydrocarbon, and have found that by adding the sulfur-containing unsaturated hydrocarbon polymer to a rubber composition for a tire, it is possible to improve wet grip performance and fuel efficiency of the tire in a well-balanced manner, thereby completing the present invention. That is, according to the present invention, the following inventions are provided. [1] A sulfur-containing unsaturated hydrocarbon polymer, being a reaction product obtained by reacting sulfur with an unsaturated bond of a polymer of an unsaturated hydrocarbon.[2] The sulfur-containing unsaturated hydrocarbon polymer according to [1], wherein the unsaturated hydrocarbon comprises an alicyclic unsaturated compound.[3] The sulfur-containing unsaturated hydrocarbon polymer according to [2], wherein the alicyclic unsaturated compound comprises a compound having a norbornene skeleton.[4] The sulfur-containing unsaturated hydrocarbon polymer according to [3], wherein the compound having a norbornene skeleton comprises dicyclopentadiene.[5] The sulfur-containing unsaturated hydrocarbon polymer according to [3] or [4], wherein only an unsaturated bond in the norbornene skeleton reacts with sulfur.[6] A method for producing a sulfur-containing unsaturated hydrocarbon polymer, comprising the step of reacting sulfur with a polymer of unsaturated hydrocarbon.[7] The method for producing a sulfur-containing unsaturated hydrocarbon polymer according to [6], wherein the unsaturated hydrocarbon comprises an alicyclic unsaturated compound.[8] An additive for rubber comprising the sulfur-containing unsaturated hydrocarbon polymer according to any one of [1] to [5].[9] The additive for rubber according to [8], being an agent for improving viscoelastic property of a tire.[10] The additive for rubber according to [8], being an agent for improving cut chip resistance of a tire.[11] A rubber composition comprising the additive for rubber according to any one of [8] to [10] and a rubber component.[12] The rubber composition according to [11], for use in a tire.[13] A tire produced by using the rubber composition according to [11] or [12]. Effect of the Invention It is possible to improve wet grip performance and fuel efficiency of a tire in a well-balanced manner by adding a sulfur-containing unsaturated hydrocarbon polymer of the present invention to a rubber composition for a tire. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a 1H-NMR chart of Sulfur-containing unsaturated hydrocarbon polymer A synthesized in Preparation Example 1. MODE FOR CARRYING OUT THE INVENTION [Sulfur-Containing Unsatu