Rubber composition and pneumatic tire

Patent metadata

Field	Value
Publication number	US-9932460-B2
Application number	US-201214002881-A
Country	US
Kind code	B2
Filing date	Apr 20, 2012
Priority date	Apr 22, 2011
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, and abrasion resistance in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a liquid resin having a softening point of −20 to 20° C., wherein the rubber component contains, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with a specific compound; and an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component.

First claim

The invention claimed is:

1. A rubber composition, comprising a rubber component, silica, and a liquid resin having a softening point of −20 to 20° C.,
wherein the rubber component contains, based on 100% by mass of the rubber component, 5 to 90% by mass of a conjugated diene polymer containing a constituent unit based on 1,3-butadiene, a constituent unit based on styrene, and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with at least one compound selected from the group consisting of a compound represented by formula (II) below, a compound represented by formula (IIIa-2) below, a compound represented by formula (IIIa-3) below, a compound represented by formula (IIIb-1-1) below, a compound represented by formula (IIIb-1-2) below, a compound represented by formula (IV) below, a compound represented by formula (Va-2) below, a compound represented by formula (VIa) below, and a compound represented by formula (VII-1) below,
wherein the rubber component further contains natural rubber and polybutadiene rubber,
wherein the rubber component contains, based on 100% by mass of the rubber component, 5 to 60% by mass of natural rubber,
wherein the rubber component contains, based on 100% by mass of the rubber component, 5 to 60% by mass of polybutadiene rubber,
wherein the liquid resin is at least one selected from the group consisting of liquid coumarone-indene resin, liquid indene resin, liquid α-methylstyrene resin, and liquid polyisopentane resin,
wherein an amount of the liquid resin is 1 to 60 parts by mass per 100 parts by mass of the rubber component, and
an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component,

wherein X 1 , X 2 , and X 3 each independently represent, a hydroxyl group or a C 1-4 alkyl group, and two of X 1 , X 2 , and X 3 are hydroxyl groups;

wherein n represents an integer of 1 to 10; R 11 , R 12 , and R 13 each independently represent a C 1-4 alkyl group or a C 1-4 alkoxy group, and at least one of R 11 , R 12 , or R 13 is an alkoxy group; and A 1 is a group represented by the formula (IIa):

wherein R 14 and R 15 each independently represent a C 1-6 alkyl group, a C 1-6 alkylene oxide group, a C 1-6 alkylene oxide alkyl group, or a C 1-6 trialkylsilyl group;

wherein e represents an integer of 2 to 7, and R 34 and R 35 each independently represent a C 1-20 alkyl group;

wherein f represents an integer of 2 to 7, and R 36 represents a C 1-20 alkyl or aryl group;

wherein r represents an integer of 1 or 2; and Y 1 represents a dialkylamino group, an imidazolyl group, or a morpholino group, and when a plurality of Y 1 's are present, the plurality of Y 1 's may be the same as or different from one another;

wherein s represents an integer of 1 or 2; t represents an integer of 0 to 2; Y 2 and Y 3 each represent a dialkylamino group, an imidazolyl group, or a morpholino group, and when a plurality of Y 2 's are present, the plurality of Y 2 's may be the same as or different from one another, and when a plurality of Y 3 's are present, the plurality of Y 3 's may be the same as or different from one another;

wherein g represents an integer of 1 to 10; R 21 represents a hydrogen atom, a C 1-6 alkyl group, or a C 1-6 alkoxyalkyl group; A 3 represents the following group: —NR 22 — where R 22 represents a hydrogen atom or a C 1-4 alkyl group; and A 4 is a group represented by the formula (IVa):

wherein R 23 and R 24 each independently represent a C 1-6 alkyl group, a C 1-6 alkylene oxide group, a C 1-6 alkylene oxide alkyl group, or a C 1-6 trialkylsilyl group;

wherein j, k, and l each independently represent an integer of 1 to 10; and R 52 to R 60 each independently represent a C 1-4 alkyl group or a C 1-4 alkoxy group, at least one of R 52 , R 53 , and R 54 is an alkoxy group, at least one of R 55 , R 56 , and R 57 is an alkoxy group, and at least one of R 58 , R 59 , and R 60 is an alkoxy group;

wherein v represents an integer of 1 to 10; R 61 , R 62 , and R 63 each independently represent a C 1-4 alkyl group or a C 1-4 alkoxy group, and at least one of R 61 , R 62 , and R 63 is an alkoxy group; and R 64 represents a C 1-10 alkyl group;

wherein z represents an integer of 0 to 10; R 71 represents a C 1-5 alkyl group; R 72 , R 73 , R 74 and R 75 each independently represent a hydrogen atom, a C 1-5 alkyl group, a C 1-5 alkoxyalkyl group, or a C 1-5 alkoxy group, and when a plurality of R 72 's and a plurality of R 73 's are present, the plurality of R 72 's and the plurality of R 73 's may be the same as or different from one another; and R 76 and R 77 each independently represent a C 1-6 alkyl group.

2. The rubber composition according to claim 1 ,
wherein one of R 74 and R 75 in formula (VII-1) is a hydrogen atom.

3. The rubber composition according to claim 1 ,
wherein the conjugated diene polymer has a vinyl bond content of at least 10 mol % but not more than 80 mol % per 100 mol % of the constituent unit based on 1,3-butadiene.

4. The rubber composition according to claim 1 ,
wherein the silica has a nitrogen adsorption specific surface area of 40 to 400 m 2 /g.

5. The rubber composition according to claim 1 , which is for use as a rubber composition for a tread.

6. A pneumatic tire, produced using the rubber composition according to claim 1 .

Assignees

• Tsumori Isamu
• Uesaka Kenichi
• Omura Naoya
• Kunisawa Tetsuya
• Tanaka Tatsuhiro
• Nishioka Kazuyuki
• Sumitomo Rubber Ind

Inventors

• Tsumori Isamu
• Uesaka Kenichi
• Omura Naoya
• Kunisawa Tetsuya
• Tanaka Tatsuhiro
• Nishioka Kazuyuki

Classifications

• C08C19/44

  of polymers containing metal atoms exclusively at one or both ends of the skeleton · CPC title

• C08K3/36 Primary

  Silica · CPC title

• C08L15/00

  Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence) · CPC title

• Y02T10/862

  Cross-Sectional Technologies · mapped topic

• B60C1/0016

  Compositions of the tread · CPC title