JPH05255543A - Rubber composition - Google Patents

Abstract

(57) [Abstract] [Purpose] Grip performance is improved by compounding a specific compound with rubber used for tires. [Configuration] The anilide compound represented by is compounded in the rubber together with the filler. R ¹ in the formula is hydrogen atom, alkanoyl group, amino group, nitro group, cyano group, hydroxyl group, carboxyl group,
It is a phenoxy group, a benzoyl group or a halogen atom, and R ² is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. [Effect] Since the loss coefficient (tan δ) of the rubber compounded with the above anilide compound is improved particularly in a high temperature region, the grip force of the tire can be increased. Further, the strength characteristics of rubber are not impaired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition, and more particularly to a rubber composition having an increased rubber loss coefficient (tan δ) without impairing mechanical strength.

[0002]

2. Description of the Related Art In recent years, as automobiles have become more sophisticated, roads have been paved, and highway networks have developed, there has been an increasing demand for improvement in tire grip performance, which is closely related to automobile acceleration performance and brake performance. There is. To obtain high grip performance, it is known that the energy loss due to friction between the tread portion of the tire and the road surface should be increased, and correspondingly, the loss coefficient during deformation (tan δ) Large tread rubber materials are required.

Conventionally, as a technique for increasing tan δ during deformation, a method of using a styrene-butadiene copolymer rubber having a high styrene content as a base, a method of adding a large amount of process oil, and a carbon black having a high reinforcing property are used. A method of adding a large amount has been proposed. In addition,
Japanese Patent No. 70539 discloses that the grip property is improved by compounding a rubber with a p-phenylenediamine derivative having an acryloyl group or a methacryloyl group such as N-methacryloyl-N'-phenyl-p-phenylenediamine. Has been done.

[0004]

When a styrene-butadiene rubber having a high styrene content is used, the grip performance is improved to some extent, but this is not always sufficient. In addition, although a method of adding a large amount of process oil or high-reinforcing carbon black can improve the grip performance, the high addition increases the heat generation property of the rubber, and the strength characteristics and wear resistance of the rubber increase accordingly. There was a problem of a significant decrease. On the other hand, JP 64-70539
The method of blending a p-phenylenediamine derivative having an acryloyl group or a methacryloyl group described in JP-A No. 1994-58500 increases the tan δ of rubber, but the problem has been clarified that such blending deteriorates the strength characteristics.

From such a background, the present inventors have found that tan δ
As a result of earnest researches to develop a compounding agent that can improve the grip performance, especially the grip performance especially when the tire temperature becomes high, and does not impair the mechanical strength. Invented.

[0006]

That is, the present invention provides rubber with the following general formula (I):

[0007]

[Chemical 3]

(In the formula, R ¹ is a hydrogen atom, an alkanoyl group, an amino group, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a phenoxy group, a benzoyl group or a halogen atom, and R ² is a hydrogen atom or a carbon number of 1 The present invention provides a rubber composition containing an anilide compound represented by 10 to 10 alkyl groups). In addition, the present invention, in rubber,
Provided is a method of increasing the loss factor of rubber by blending a filler and the anilide compound represented by the general formula (I).

As the anilide compound represented by the above general formula (I), for example, the corresponding aniline compound is triethylamine, in an inert solvent such as toluene or chloroform,
It can be produced by dehydrochlorination reaction with saturated fatty acid chloride in the presence of a basic compound such as pyridine and sodium hydroxide.

In the general formula (I), R ¹ is a hydrogen atom, an alkanoyl group, an amino group, a nitro group, a cyano group,
It is a hydroxyl group, a carboxyl group, a phenoxy group, a benzoyl group or a halogen atom. Among these, alkanoyl group, cyano group and phenoxy group are preferable. R
^The alkanoyl group represented by ¹ has a total number of carbon atoms of about 2 to 9, and those having a relatively small number of carbon atoms, for example, those having a total number of carbon atoms of about 2 to 6 are preferable.
Acetyl, propionyl, butyryl, isobutyryl and the like are preferable. Among these alkanoyl groups, acetyl is particularly preferable. The amino group represented by R ¹ may be unsubstituted amino or mono- or di-substituted amino. Examples of the group which may be substituted on the amino group include, for example,
Examples thereof include lower alkyl groups such as methyl and ethyl, and phenyl groups. Therefore, the amino group which can be R ¹ includes methylamino, ethylamino, dimethylamino, diethylamino, anilino and the like. Examples of the halogen atom represented by R ¹ include fluorine, chlorine, bromine and iodine, and chlorine is preferable.

R ² in the general formula (I) is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The alkyl group having 3 or more carbon atoms may be linear or branched. R ² is an alkyl group having a relatively small number of carbon atoms such as methyl, ethyl, propyl,
Butyl and the like are preferable, and methyl is particularly preferable.

In the present invention, among these anilide compounds of the general formula (I), those in which R ¹ is acetyl and R ² is methyl are preferably used.

Examples of the anilide compound represented by the general formula (I) that can be used in the present invention include those shown in the following table. In the table, o-in the R ¹ column,
m- and p- each represent a substitution position based on the position of the amide group on the benzene ring.

[0014]

[Chemical 4]

R ¹ R ² (1) hydrogen hydrogen (2) hydrogen methyl (3) p-acetyl methyl (4) pn-hexanoyl methyl (5) p-aminomethyl (6) p-nitromethyl (7) p-Cyanomethyl (8) p-Hydroxymethyl (9) p-Carboxymethyl (10) p-Dimethylaminomethyl (11) p-Diethylaminomethyl (12) p-Anilinomethyl (13) p-Phenoxymethyl (14) p-chloromethyl (15) p-iodomethyl (16) p-benzoylmethyl (17) o-acetylmethyl (18) m-acetylmethyl (19) o-dimethylaminomethyl (20) m-dimethylaminomethyl (21) ) P-cyano ethyl (22) p-cyano n-propyl (23) p-cyano isopropyl ( 24) p-cyano t-butyl (25) p-cyano n-octyl (26) p-cyano 1,1,3,3-tetramethylbutyl (27) p-dimethylamino ethyl (28) p-dimethylamino t -Butyl (29) p-dimethylamino n-octyl (30) o-chloroethyl (31) m-chloro n-pentyl (32) o-cyanoethyl (33) m-cyano t-butyl (34) p-carboxy Ethyl (35) p-carboxy n-octyl (36) p-carboxy t-butyl (37) o-nitro ethyl (38) m-nitro n-octyl (39) p-anilino ethyl (40) p-phenoxy ethyl

When the anilide compound of the general formula (I) is added to the rubber, each compound may be a simple substance or a mixture of a plurality of compounds, or the physical properties of the rubber may be affected. It may be mixed with a carrier such as clay that does not give The anilide compound can be added at any stage of producing a compounded rubber. In compounding the rubber, the amount of the compound represented by the general formula (I) used is not limited, but it is generally used in the range of about 0.1 to 20 parts by weight per 100 parts by weight of the rubber.

As the filler used in the present invention, various fillers used in the rubber industry can be applied, but carbon black is generally preferred. The type of carbon black is not particularly limited, and various types of carbon black conventionally used in the rubber industry can be used in the present invention. In order to improve the grip performance of tires, SAF black, ISAF
Nitrogen adsorption specific surface area such as black, HAF black 80
Highly reinforcing carbon black of up to 250 m ² / g is used, and it is preferable to use such highly reinforcing carbon black also in the present invention. The compounding amount of the filler is not particularly limited, but generally 2 parts with respect to 100 parts by weight of rubber.
A range of about 0 to 200 parts by weight is preferable.

The types of rubber that can be used in the present invention include natural rubber, polyisoprene rubber (IR),
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, blend of natural rubber and synthetic rubber, and SBR and IR, SBR and BR
As an example, a blend of synthetic rubber is exemplified. Recently, SBR having a particularly high styrene content is preferably used in order to improve the grip performance of the tire. However, in the present invention, such an SBR having a high styrene content can also be used. The present invention has a styrene content of 20 to 50.
It is also effective for SBR of weight%, and such S
BR is one of the preferred rubbers. The type of SBR may be a solution polymerization type or an emulsion polymerization type.

In compounding the tire tread rubber material,
Conventionally, a method of blending a process oil has been often used in order to improve grip performance of a tire, but in the present invention, a process oil can be used together and is preferable. The blending amount of the process oil is not particularly limited, but is generally 200 parts by weight or less per 100 parts by weight of rubber, and preferably selected from the range of 5 to 200 parts by weight. The type of process oil is 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 an antiaging agent, a vulcanizing agent, a vulcanization accelerator, a retarder, a peptizer, and a softening agent, are used in the same manner as before. It goes without saying that you may do so.

[0021]

EXAMPLES Next, the present invention will be described in more detail with reference to the examples in which the compound represented by the general formula (I) was blended with rubber to evaluate the physical properties, but the present invention is limited by these. Not a thing. In the following examples,% and parts are based on weight unless otherwise specified.

The compounds used in Examples and Comparative Examples are as follows, and are represented by respective symbols below. A: formanilide B: p-acetylacetanilide C: p-cyanoacetanilide D: p-phenoxyacetanilide E: p-chloroacetanilide F: p-cyanopivalanilide G: o-cyanopropionanilide H: m-nitro-n -Nonaneanilide I: N-phenyl-N'-propionyl-p-phenylenediamine X: N-methacryloyl-N'-phenyl-p-phenylenediamine

Example 1 [Compounding Formulation] Styrene / Butadiene Copolymer Rubber Table-1 Description (styrene content 35%, aromatic oil 37.5 parts per 100 parts rubber) Butadiene rubber (BR-01) Table-1 Description However, listed in Table-1 ISAF carbon black Listed in Table-1 Stearic acid 3 parts Platinum flower 5 parts Aromatic process oil Listed in Table-1 Vulcanization accelerator 1 part (N-cyclohexyl-2- Benzothiazole sulfenamide) Iou 2 parts Compounds listed in Table-1

2 made by Toyo Seiki as a Banbury mixer
Oil bath temperature of 17 using 50 ml Labo Plastomill ^R
At 0 ° C., the compound of the present invention, carbon black, stearic acid, process oil, and zinc white were added to the rubber based on the above compounding recipe, and kneaded at a mixer rotation speed of 50 rpm for 5 minutes. The rubber temperature at this time is 160-1
It was 70 ° C. Next, this rubber compound was transferred to an open mill, and the vulcanization accelerator and sulfur shown in the above compounding formulation were added and kneaded at a temperature of 40 to 50 ° C.

Further, it was vulcanized by a vulcanizing press to obtain a predetermined shape and then subjected to measurement of tan δ. Measurement of tan δ, using a viscoelasticity spectrometer manufactured by Iwamoto
It was carried out at a temperature of −50 ° C. to 100 ° C. under the condition of a frequency of 10 Hz. As a mechanical strength test, a vulcanized rubber test piece (Dumbbell No. 3 according to JIS K 6301) prepared from the rubber composition was used to measure M ₁₀₀ and M ₃₀₀ at room temperature. Of the results obtained, tan δ at 80 ° C,
Table 1 shows M ₁₀₀ and M ₃₀₀ at room temperature. In the table,
If the M ₃₀₀ column is blank, it means that measurement was impossible.

[0026]

[0027]

[0028]

[0029]

[0030]

EFFECTS OF THE INVENTION According to the present invention, by blending a specific anilide compound with rubber, it can be used in a high temperature region of 60 ° C. or higher corresponding to the grip force when the tire temperature is high.
It is possible to effectively improve tan δ, and there is almost no deterioration in strength characteristics. Therefore, when the rubber composition according to the present invention is applied to the tire, especially the tread portion, a tire having excellent grip performance, which is closely related to the acceleration performance and brake performance of an automobile, can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Nagasaki 3-98 Kasugade, Konohana-ku, Osaka City Sumitomo Chemical Co., Ltd. No. 1-98 Sumitomo Chemical Co., Ltd.

Claims (3)

[Claims] 1. A rubber, a filler, and the following general formula: (In the formula, R ¹ is a hydrogen atom, an alkanoyl group, an amino group,
A nitro group, a cyano group, a hydroxyl group, a carboxyl group, a phenoxy group, a benzoyl group or a halogen atom, and R ²
Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms)
A rubber composition comprising an anilide compound represented by: 2. R ¹ in the general formula of the anilide compound
The rubber composition according to claim 1, wherein is acetyl and R ² is methyl. 3. A rubber, a filler and the following general formula: (In the formula, R ¹ is a hydrogen atom, an alkanoyl group, an amino group,
A nitro group, a cyano group, a hydroxyl group, a carboxyl group, a phenoxy group, a benzoyl group or a halogen atom, and R ²
Is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms)
A method for increasing the loss factor of rubber, which comprises blending an anilide compound represented by