# US 12,600,837 B2 · Rubber composition and crosslinked rubber molded product

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- Number: US 12,600,837 B2
- Document ID: US12600837B2
- Status: Granted
- Kind: B2
- Application number: 17/836,392
- Filed: 2022-06-09
- Published: 2022-12-29
- Granted: 2026-04-14
- Earliest claimed: 2021-06-11
- Assignees: Sumitomo Rubber Industries, Ltd.
- Applicants: Sumitomo Rubber Industries, Ltd.
- Inventors: Hiroshi Tadaoka; Kazuyoshi Shiga; Takahiro Shigemitsu
- Web page: https://patentgrep.com/patent/US12600837B2

## CPC

- C08K 5/47: Thiazoles
- A63B 37/005: {Cores}
- C08F 136/06: Butadiene
- C08K 3/22: of metals
- C08K 5/098: Metal salts of carboxylic acids
- C08K 5/14: Peroxides
- C08K 5/372: Sulfides {, e.g. R-(S)x-R'}
- C08L 21/00: Compositions of unspecified rubbers
- C08K 2003/2296: {of zinc}
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

An object of the present disclosure is to provide a rubber composition from which a crosslinked rubber molded product having good softness and excellent resilience performance can be obtained. The present disclosure provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) a salt of a benzothiazole derivative, wherein (d) the salt of the benzothiazole derivative includes a compound represented by the formula (1) in which a sulfur atom S2 constituting a thiocarbonyl group has a Mulliken charge of −0.190 or more. [In the formula (1), R1 to R4 are identical to or different from each other, and represent an electron-withdrawing group or a hydrogen atom, S1 and S2 represent a sulfur atom, X represents a cation component, n is an integer ranging from 1 to 4, and at least one of R1 to R4 bonding to the identical benzene ring is an electron-withdrawing group when n is 2 or more.]

## Claims

### Claim 1

A rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) a salt of a benzothiazole derivative,
wherein (d) the salt of the benzothiazole derivative includes a compound represented by the formula (2) in which a sulfur atom S2 constituting a thiocarbonyl group has a Mulliken charge of −0.185 or more,
wherein in the formula (2),
R1 represents an electron-withdrawing group selected from the group consisting of a halogen group, a perfluoroalkyl group, and a pentafluorosulfanyl group,
S1 and S2 represent a sulfur atom,
X represents a cation component, and
n is an integer ranging from 1 to 4.

### Claim 2 (depends on 1)

The rubber composition according to claim 1, wherein the electron-withdrawing group represented by R1 is selected from the group consisting of a fluoro group, a chloro group, a bromo group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a pentafluorosulfanyl group.

### Claim 3 (depends on 1)

The rubber composition according to claim 1, wherein an amount of (d) the salt of the benzothiazole derivative ranges from 0.01 part by mass to 20 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 4 (depends on 1)

The rubber composition according to claim 1, wherein an amount of (b) the co-crosslinking agent ranges from 15 parts by mass to 50 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 5

A crosslinked rubber molded product formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) a salt of a benzothiazole derivative,
wherein (d) the salt of the benzothiazole derivative includes a compound represented by the formula (2) in which a sulfur atom S2 constituting a thiocarbonyl group has a Mulliken charge of −0.185 or more,
wherein in the formula (2),
R1 represents an electron-withdrawing group selected from the group consisting of a halogen group, a perfluoroalkyl group, and a pentafluorosulfanyl group,
S1 and S2 represent a sulfur atom,
X represents a cation component, and
n is an integer ranging from 1 to 4.

### Claim 6 (depends on 5)

The crosslinked rubber molded product according to claim 5, wherein the electron-withdrawing group represented by R1 is selected from the group consisting of a fluoro group, a chloro group, a bromo group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a pentafluorosulfanyl group.

### Claim 7 (depends on 5)

The crosslinked rubber molded product according to claim 5, wherein an amount of (d) the salt of the benzothiazole derivative ranges from 0.01 part by mass to 20 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 8 (depends on 5)

The crosslinked rubber molded product according to claim 5, wherein an amount of (b) the co-crosslinking agent ranges from 15 parts by mass to 50 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 9

A golf ball comprising a constituent member formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) a salt of a benzothiazole derivative,
wherein (d) the salt of the benzothiazole derivative includes a compound represented by the formula (2) in which a sulfur atom S2 constituting a thiocarbonyl group has a Mulliken charge of −0.185 or more,
wherein in the formula (2),
R1 represents an electron-withdrawing group selected from the group consisting of a halogen group, a perfluoroalkyl group, and a pentafluorosulfanyl group,
S1 and S2 represent a sulfur atom,
X represents a cation component, and
n is an integer ranging from 1 to 4.

### Claim 10 (depends on 9)

The golf ball according to claim 9, wherein the electron-withdrawing group represented by R1 is selected from the group consisting of a fluoro group, a chloro group, a bromo group, a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a pentafluorosulfanyl group.

### Claim 11 (depends on 9)

The golf ball according to claim 9, wherein an amount of (d) the salt of the benzothiazole derivative ranges from 0.01 part by mass to 20 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 12 (depends on 9)

The golf ball according to claim 9, wherein an amount of (b) the co-crosslinking agent ranges from 15 parts by mass to 50 parts by mass with respect to 100 parts by mass of (a) the base rubber.

### Claim 13 (depends on 1)

The rubber composition according to claim 1, wherein the rubber composition further contains (f) an organic sulfur compound excluding (d) the salt of the benzothiazole derivative.

### Claim 14 (depends on 5)

The crosslinked rubber molded product according to claim 5, wherein the rubber composition further contains (f) an organic sulfur compound excluding (d) the salt of the benzothiazole derivative.

### Claim 15 (depends on 9)

The golf ball according to claim 9, wherein the rubber composition further contains (f) an organic sulfur compound excluding (d) the salt of the benzothiazole derivative.