JPH04249551A - Rubber composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a rubber composition having high grip performance suitable as a tire tread material, and more specifically, to a rubber composition having an increased loss coefficient (tan δ) without impairing mechanical strength. The present invention relates to a rubber composition.

0002

[Background Art] In recent years, as automobiles have become more sophisticated, roads have become more paved, and expressway networks have developed, there has been an increasing demand for improved tire grip performance, which is closely related to automobile acceleration and braking performance. There is. It is known that in order to obtain high grip performance, it is sufficient to increase the energy loss due to friction between the tire tread and the road surface.
) is in demand.

Conventionally, techniques for increasing tan δ during deformation include a method of using styrene-butadiene copolymer rubber with a high styrene content as a base, a method of adding a large amount of process oil, and a method of adding highly reinforcing carbon black. A method of adding a large amount has been proposed. Furthermore, JP-A-64-70539 discloses p-methacryloyl-N'-phenyl-p-phenylenediamine and other
It is described that grip properties can be improved by blending a phenylenediamine derivative into rubber.

0004

[Problems to be Solved by the Invention] When using styrene-butadiene rubber with a high styrene content, although some improvement in grip performance can be seen, this alone has not always been sufficient. Furthermore, although the grip performance is improved by adding a large amount of process oil or highly reinforcing carbon black, the addition of a large amount increases the heat generation property of the rubber, and as a result, the strength properties and wear resistance deteriorate. There was a problem of a significant drop in the performance. On the other hand, Japanese Patent Publication No. 64-7
Although the method of blending a p-phenylenediamine derivative described in Publication No. 0539 increases the tan δ of the rubber, it has become clear that such blending causes a decrease in strength properties.

[0005] Against this background, the present inventors have developed ta
As a result of intensive research to develop a compound that can sufficiently increase nδ and thereby improve grip performance, especially grip performance when the tire becomes hot, without impairing mechanical strength, we have found that: This led to the present invention.

[0006]

[Means for Solving the Problems] That is, the present invention provides rubber with a filler and the following general formula (I).

[0007]

[Chemical formula 3]

(In the formula, R1 is a hydrogen atom, an alkyl group,
a substituted or unsubstituted phenyl group, or a substituted or unsubstituted benzyl group, R2 is a hydrogen atom, an alkyl group, an alkoxy group, an alkanoyl group, a phenoxy group,
Provided is a rubber composition containing a benzamide compound represented by a benzoyl group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a substituted or unsubstituted amino group, or a halogen atom. The present invention also provides a method of increasing the loss coefficient of rubber by blending a filler and a benzamide compound represented by the general formula (I) into rubber.

The benzamide compound represented by the general formula (I) can be prepared by, for example, converting the corresponding amine compound into toluene,
triethylamine, in an inert solvent such as chloroform,
It can be produced by dehydrochlorination reaction with the corresponding benzoyl chloride compound in the presence of a basic compound such as pyridine or sodium hydroxide.

In the general formula (I), R1 is a hydrogen atom, an alkyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted benzyl group. R1
The alkyl group represented by, for example, has 1 to 1 carbon atoms.
About 0 carbon atoms are suitable, and those having 3 or more carbon atoms may be linear or branched.

The phenyl group or benzyl group represented by R1 may be unsubstituted or substituted with a nucleus. Examples of groups that can be substituted on the benzene ring of the phenyl group or benzyl group include lower alkyl groups, lower alkoxy groups, lower alkanoyl groups, phenoxy groups, amino groups, nitro groups, cyano groups, hydroxyl groups, carboxyl groups, and halogen atoms. It will be done.

[0012] "Lower" as used herein refers to an alkyl moiety having about 1 to 5 carbon atoms, and those having 3 or more carbon atoms may be linear or branched. . Preferred lower alkyl groups include methyl, ethyl, propyl,
Examples include butyl, preferred lower alkoxy groups include methoxy, ethoxy, propoxy, etc., and preferred lower alkanoyl groups include acetyl, propionyl, and the like.

When R1 is a phenyl group or a benzyl group, the amino group that can be substituted therein may be unsubstituted amino or mono- or di-substituted amino. Examples of substituents for the amino group include methyl, ethyl, phenyl, and the like. Therefore, the amino group here includes unsubstituted amino, methylamino, ethylamino, anilino,
Dimethylamino, diethylamino, etc. are included.

When R1 is a phenyl group or a benzyl group, examples of the halogen atom which can be substituted there include fluorine, chlorine, bromine, and iodine.

In the general formula (I), R2 represents a hydrogen atom, an alkyl group, an alkoxy group, an alkanoyl group, a phenoxy group, a benzoyl group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or a substituted or unsubstituted amino group. group, or a halogen atom.

Examples of the alkyl group, alkoxy group and alkanoyl group that can be R2 include lower members in which the alkyl moiety has about 1 to 5 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, methoxy, ethoxy, propoxy, Examples include butoxy, pentyloxy, acetyl, propionyl, butyryl, valeryl, hexanoyl and the like. An alkyl moiety having 3 or more carbon atoms may be linear or branched.

The amino group represented by R2 may be unsubstituted amino or mono- or di-substituted amino. Examples of substituents for the amino group include methyl, ethyl, and phenyl. Therefore, the amino group here is
Included are unsubstituted amino, methylamino, ethylamino, anilino, dimethylamino, diethylamino, and the like.

The halogen atom represented by R2 is:
Examples include fluorine, chlorine, bromine, and iodine.

The above general formula (
Specific examples of the benzamide compound I) include the following.

A. A benzamide compound in which R1 is a hydrogen atom or an alkyl group in general formula (I):
(A1) Benzamide (A2) 4-aminobenzamide (A3)
N-methylbenzamide (A4) 4,N-
Dimethylbenzamide (A5) N-methyl-4
-n-Butylbenzamide (A6) N-methyl-4-methoxybenzamide (A7) N-methyl-4-ethoxybenzamide (A8) N-methyl-4-aminobenzamide (A9) N-methyl-4-nitrobenzamide ( A10) N-methyl-4-cyanobenzamide (A11) N-methyl-4-hydroxybenzamide (A12) N
-Methyl-4-carboxybenzamide (A13)
N-methyl-4-dimethylaminobenzamide (A1
4) N-methyl-4-diethylaminobenzamide (A15) N-methyl-4-anilinobenzamide (A16) N-methyl-4-phenoxybenzamide (A17) N-methyl-4-chlorobenzamide (A18) N-methyl -4-iodobenzamide (A19) N-methyl-4-benzoylbenzamide (A20) N-methyl-2-methoxybenzamide (A21) N-methyl-3-methoxybenzamide (A22) N-methyl-2-nitrobenzamide ( A23) N-methyl-3-nitrobenzamide (A24) N-n-butylbenzamide (A25) N-t-butylbenzamide (A26) N-n-octylbenzamide (A2
7) N-n-propyl-4-methoxybenzamide (A28) N-t-butyl-4-methoxybenzamide (A29) N-n-octyl-4-methoxybenzamide (A30) N-(1,1,3,
3-tetramethylbutyl)-4-methoxybenzamide (A31) N-ethyl-4-dimethylaminobenzamide (A32) N-t-butyl-4-dimethylaminobenzamide (A33) N-n-octyl-4-dimethylamino Benzamide (A34) N-n-propyl-2-chlorobenzamide (A35) N-n-octyl-3-chlorobenzamide (A36) N-n-propyl-2-
Cyanobenzamide (A37) N-t-butyl-
3-cyanobenzamide (A38) N-n-propyl-4-carboxybenzamide (A39) N-n-octyl-4-carboxybenzamide (A40) N-t-butyl-4-carboxybenzamide (A41) N-ethyl- 2-nitrobenzamide (A42) N-n-octyl-3-nitrobenzamide (A43) N-ethyl-4-anilinobenzamide (A44) N-ethyl-4-phenoxybenzamide

Among these, preferred are benzamide, N-methylbenzamide,
N-methyl-4-methoxybenzamide and the like.

B. Benzanilide compounds in which R1 is a substituted or unsubstituted phenyl group in general formula (I): (B1) Benzanilide (B2) N-(4-methylphenyl)benzamide (B3) N-(4-n-propylphenyl) Benzamide (B4) N-(4-n-pentylphenyl)benzamide (B5) N-(4-t-butylphenyl)benzamide (B6) N-(4-methoxyphenyl)benzamide (B7) N-(4-ethoxy phenyl)benzamide (B8) N-(4-t-
Butoxyphenyl)benzamide (B9) N-(4-acetylphenyl)benzamide (B10) N-(4-propionylphenyl)benzamide (B11) N-(4-n-hexanoylphenyl)benzamide (B12) N-(4 -aminophenyl)benzamide (B13) N-(4-nitrophenyl)benzamide (B14) N-(4-cyanophenyl)
Benzamide (B15) N-(4-hydroxyphenyl)benzamide (B16) N-(4-carboxyphenyl)benzamide (B17) N-(
4-dimethylaminophenyl)benzamide (B18) N-(4-diethylaminophenyl)
Benzamide (B19) N-(4-anilinophenyl)benzamide (B20) N-(4-phenoxyphenyl)benzamide (B21) N-(3-methylphenyl)benzamide (B22) N-(2-methylphenyl)benzamide (B23) N-(3-ethoxyphenyl)benzamide (B24) N-(
2-ethoxyphenyl)benzamide (B25)
N-(4-ethoxyphenyl)-4-methylbenzamide (B26) N-(4-ethoxyphenyl)-4-
Methoxybenzamide (B27) N-(4-ethoxyphenyl)-4-
Acetylbenzamide (B28) N-(4-ethoxyphenyl)-4-
Aminobenzamide (B29) N-(4-ethoxyphenyl)-4-
Nitrobenzamide (B30) N-(4-ethoxyphenyl)-4-
Cyanobenzamide (B31) N-(4-ethoxyphenyl)-4-
Hydroxybenzamide (B32) N-(4-ethoxyphenyl)-4-
Carboxybenzamide (B33) N-(4-ethoxyphenyl)-4-
Dimethylaminobenzamide (B34) N-(4-ethoxyphenyl)-4-
Anilinobenzamide (B35) N-(4-ethoxyphenyl)-4-
Phenoxybenzamide (B36) N-(4-acetylphenyl)-4-
Aminobenzamide (B37) N-(4-acetylphenyl)-4-
Dimethylaminobenzamide (B38) N-(4-anilinophenyl)-4-
Methoxybenzamide (B39) N-(4-anilinophenyl)-4-
Acetylbenzamide (B40) N-(4-phenoxyphenyl)-4
-methoxybenzamide

Among these, preferred compounds include benzanilide, N-(4-methoxyphenyl)benzamide, and N-(4-ethoxyphenyl)benzamide. Benzanilide is preferred from the viewpoint of ease of availability or production.

C. N-benzylbenzamide compound in which R1 is a substituted or unsubstituted benzyl group in general formula (I): (C1) N-benzylbenzamide (C2)
N-(4-methylbenzyl)benzamide (C3
) N-(4-n-propylbenzyl)benzamide (C4) N-(4-n-pentylbenzyl)benzamide (C5) N-(4-t-butylbenzyl)benzamide (C6) N-(4-methoxybenzyl ) Benzamide (C7) N-(4-ethoxybenzyl)benzamide (C8) N-(4-t-
Butoxybenzyl)benzamide (C9) N-(4-acetylbenzyl)benzamide (C10) N-(4-propionylbenzyl)benzamide (C11) N-(4-n-hexanoylbenzyl)benzamide (C12) N-(4 -aminobenzyl)benzamide (C13) N-(4-nitrobenzyl)benzamide (C14) N-(4-cyanobenzyl)
Benzamide (C15) N-(4-hydroxybenzyl)benzamide (C16) N-(4-carboxybenzyl)benzamide (C17) N-(
4-dimethylaminobenzyl)benzamide (C18) N-(4-diethylaminobenzyl)
Benzamide (C19) N-(4-anilinobenzyl)benzamide (C20) N-(4-phenoxybenzyl)benzamide (C21) N-(3-methylbenzyl)benzamide (C22) N-(2-methylbenzyl)benzamide (C23) N-(3-ethoxybenzyl)benzamide (C24) N-(
2-Ethoxybenzyl)benzamide (C25)
N-(4-ethoxybenzyl)-4-methylbenzamide (C26) N-(4-ethoxybenzyl)-4-
Methoxybenzamide (C27) N-(4-ethoxybenzyl)-4-
Acetylbenzamide (C28) N-(4-ethoxybenzyl)-4-
Aminobenzamide (C29) N-(4-ethoxybenzyl)-4-
Nitrobenzamide (C30) N-(4-ethoxybenzyl)-4-
Cyanobenzamide (C31) N-(4-ethoxybenzyl)-4-
Hydroxybenzamide (C32) N-(4-ethoxybenzyl)-4-
Carboxybenzamide (C33) N-(4-ethoxybenzyl)-4-
Dimethylaminobenzamide (C34) N-(4-ethoxybenzyl)-4-
Anilinobenzamide (C35) N-(4-ethoxybenzyl)-4-
Phenoxybenzamide (C36) N-(4-acetylbenzyl)-4-
Aminobenzamide (C37) N-(4-acetylbenzyl)-4-
Dimethylaminobenzamide (C38) N-(4-acetylbenzyl)-4-
Carboxybenzamide (C39) N-(4-anilinobenzyl)-4-
Methoxybenzamide (C40) N-(4-anilinobenzyl)-4-
Acetylbenzamide (C41) N-(4-phenoxybenzyl)-4
-methoxybenzamide

Among these, preferred compounds include N-benzylbenzamide, N-(4-methoxybenzyl)benzamide, and N-(4-ethoxybenzyl)benzamide. Considering ease of availability or production, N-benzylbenzamide is preferred.

When the benzamide compound of general formula (I) is added to rubber, each compound may be added alone, a mixture of multiple compounds may be added, or a compound having an effect on the physical properties of the rubber may be added. It may also be mixed with a carrier such as clay that is not used. Such a benzamide compound can be added at any stage of producing compounded rubber. In compounding the rubber, the amount of the benzamide compound used is not limited, but it is generally preferred to use it in a range of about 0.1 to 20 parts by weight per 100 parts by weight of rubber.

Further, as the filler used in the present invention, various fillers used in the rubber industry can be used, but carbon black is generally preferred. The type of carbon black is not particularly limited, and various carbon blacks conventionally employed in the rubber industry can be used in the present invention. In addition, in order to improve the grip performance of tires, SAF black, ISAF
Black, HAF black, etc. Nitrogen adsorption specific surface area 80
~250 m2/g of highly reinforcing carbon black is used, and it is preferable to use such highly reinforcing carbon black in the present invention as well. The amount of filler blended is not particularly limited, but is generally preferably in the range of about 20 to 200 parts by weight per 100 parts by weight of rubber.

[0028] In addition to natural rubber, the types of rubber that can be used in the present invention include polyisoprene rubber (IR),
Various types of styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), acrylonitrile-butadiene copolymer rubber (NBR), isoprene-isobutylene copolymer rubber (IIR), ethylene-propylene-diene copolymer rubber (EPDM), etc. Synthetic rubber, blends of natural rubber and synthetic rubber, and SBR and IR, SBR and BR
Blends of synthetic rubber are exemplified. Note that recently, SBR with a particularly high styrene content has been preferably used to improve the grip properties of tires, and such SBR with a high styrene content can also be used in the present invention. The present invention has a styrene content of 20 to 50
It is also effective against SBR of % by weight, and such SBR
BR is one of the preferred rubbers. The type of SBR may be either a solution polymerization type or an emulsion polymerization type.

[0029] In compounding the tire tread rubber material,
Conventionally, a method of blending a process oil in order to improve the grip performance of a tire has often been used, but it is also possible and preferable to use a process oil in combination in the present invention. The amount of process oil blended is not particularly limited, but is generally 200 parts by weight or less per 100 parts by weight of rubber, preferably selected from the range of 5 to 200 parts by weight. The type of process oil is also not limited in the present invention, and various process oils conventionally used in the rubber industry can be used.

In the present invention, various rubber chemicals commonly used in the rubber industry, such as anti-aging agents, vulcanizing agents, vulcanization accelerators, retarders, peptizers, and softeners, are used in combination in the same manner as in the past. It goes without saying that it is okay to do so.

[0031]

[Example] Next, the present invention will be explained in more detail with reference to Examples in which the compound represented by the general formula (I) was blended into rubber and the physical properties were evaluated, but the present invention is not limited by these. It's not a thing. In the following examples, all percentages and parts are by weight unless otherwise specified.

The test compounds used in the examples are as follows, and are indicated by the respective symbols below.

AA: Benzamide AB: 4-aminobenzamide AC: N-methyl-4-methoxybenzamide AD
: N-methyl-4-chlorobenzamide AE:
N-t-butylbenzamide AF: N-n-octyl-4-methoxybenzamide AG: N-n-propyl-2-cyanobenzamide AH: N-n-propyl-4-carboxybenzamide AI: N-ethyl-4- Anilinobenzamide

0
BA: Benzanilide BB: N-(4-ethoxyphenyl)benzamide BC: N-(4-n-pentylphenyl)benzamide BD: N-(4-aminophenyl)benzamide B
E: N-(4-carboxyphenyl)benzamide BF: N-(4-dimethylaminophenyl)benzamide BG: N-(4-ethoxyphenyl)-4-dimethylaminobenzamide BH: N-(4-anilinophenyl) -4-methoxybenzamide BI: N-(4-phenoxyphenyl)-4-methoxybenzamide

CA: N-benzylbenzamide CB: N-(4-methoxybenzyl)benzamide CC: N-(4-n-pentylbenzyl)benzamide CD: N-(4-aminobenzyl)benzamide C
E: N-(4-ethoxybenzyl)-4-cyanobenzamide CF: N-(4-ethoxybenzyl)-4-dimethylaminobenzamide CG: N-(4-acetylbenzyl)-4-carboxybenzamide CH: N- (4-anilinobenzyl)-4-acetylbenzamide CI: N-(4-phenoxybenzyl)-4-methoxybenzamide

X: N-methacryloyl-N'-
Phenyl-p-phenylenediamine

Example 1 [Blending recipe] Styrene-butadiene copolymer rubber
Listed in Table 1 (Styrene content 35%, aromatic oil 37.5 parts per 100 parts rubber) Butadiene rubber (BR-
01)
Listed in Table-1 Natural
rubber
Listed in Table-1
ISAF carbon black
Table-1
Description stearic acid

Part 3 Zinc
flower
Part 5 Aromatic process oil
Table-1
Description Vulcanization accelerator

1 part (N-cyclohexyl-2-benzothiazolesulfenamide) a
Oh

Part 2 Test compound

Listed in Table-1

2 manufactured by Toyo Seiki as a Banbury mixer
Using a 50ml Labo Plastomill R, the test compound, carbon black, stearic acid, process oil, and zinc white were added to the rubber based on the above formulation at an oil bath temperature of 170°C, and the mixture was mixed at a mixer rotation speed of 50 rpm. Kneaded for 5 minutes. The rubber temperature at this time is 160-170℃
Met. This rubber compound is then transferred to an open mill,
The vulcanization accelerator and sulfur shown in the above formulation were added and kneaded at a temperature of 40 to 50°C.

[0039] Furthermore, after being vulcanized using a vulcanization press to form a predetermined shape, it was subjected to tan δ measurement. tan
δ was measured using a viscoelastic spectrometer manufactured by Iwamoto Seisakusho at a frequency of 10 Hz from -50°C to 100°C.
Performed at temperatures up to ℃. In addition, as a mechanical strength test,
Vulcanized rubber test piece (JIS
M100 and M300 were measured at room temperature using a dumbbell No. 3 by K 6301.

Among the results obtained, t at 80°C
anδ, M100 and M300 at room temperature are shown in Table-1.
It is shown in Table 4. Table 1 shows the compounds of group A (AA~
Table 2 shows the results when using Group B compounds (BA to BI), and Table 3 shows the results when using Group B compounds (BA to BI).
Table 4 represents the results when using Group C compounds (CA to CI), and Table 4 represents the results when no test compound was used and when Compound X was used for comparison. ing. In the table, a blank column for M300 means that measurement was not possible.

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

According to the present invention, by blending a specific compound into rubber, the tan δ in the high temperature region of 60°C or higher, which corresponds to the grip force when the tire becomes high temperature, can be improved.
can be effectively improved, with almost no deterioration in strength properties. Therefore, by applying the rubber composition according to the present invention to the tread portion of a tire, it is possible to obtain a tire with excellent grip performance, which is closely related to the acceleration performance and braking performance of an automobile.

Claims (5)

[Claims] Claim 1: A rubber, a filler and the following general formula: is a hydrogen atom, an alkyl group, an alkoxy group, an alkanoyl group, a phenoxy group, a benzoyl group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a substituted or unsubstituted amino group, or a halogen atom). A rubber composition comprising: Claim 2: The benzamide compound is benzamide, N
-Methylbenzamide or N-methyl-4-methoxybenzamide. 3. The benzamide compound is benzanilide,
N-(4-methoxyphenyl)benzamide or N-
Claim 1: (4-ethoxyphenyl)benzamide
The rubber composition described. 4. The rubber composition according to claim 1, wherein the benzamide compound is N-benzylbenzamide, N-(4-methoxybenzyl)benzamide or N-(4-ethoxybenzyl)benzamide. 5. Rubber, a filler and the following general formula: is a hydrogen atom, an alkyl group, an alkoxy group, an alkanoyl group, a phenoxy group, a benzoyl group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a substituted or unsubstituted amino group, or a halogen atom). A method for increasing the loss coefficient of rubber, characterized by compounding the rubber.