KR19990067093A - Rubber composition and air tire using it - Google Patents

Abstract

The present invention relates to silica of bis (alkoxysilyl alkyl) polysulfide having 10 to 85 parts by weight of silica and a specific silane coupling agent, that is, a polysulfide structure with a sulfur distribution, based on 100 parts by weight of natural rubber and / or diene-based rubber. The rubber composition which mix | blends 1-20 weight% with respect to the quantity of 1, and 1-15 weight% of specific silica dispersion improving agents with respect to the quantity of silica, and the air tire using the same are provided. This pneumatic tire is excellent in low heat generation and wear resistance.

Description

Rubber composition and air tire using it

Conventionally, carbon black is used as a reinforcing filler for rubber. This is because carbon black has higher reinforcement and good abrasion resistance than other fillers, but in recent years, in response to social requests for energy and resource saving, low heat generation of rubber compositions has been attempted at the same time.

When aiming to lower the heat generation of the rubber composition by carbon black, it is possible to consider the small filling of carbon black or the use of large particle carbon black. However, in either method, the low heat generation has a relationship between yield reinforcement and abrasion resistance. It is well known that On the other hand, silica is known as a low heat-generating filler of a rubber composition, and many patents, such as Unexamined-Japanese-Patent No. 3-252431, are applied.

However, silica tends to aggregate with each other by hydrogen bonding of silanol groups, which are surface functional groups, and it is necessary to lengthen the kneading time in order to improve the dispersibility of silica particles in rubber. Insufficient dispersion of the silica particles in the rubber causes problems such as high Mooney viscosity of the rubber composition and poor workability such as extrusion.

In addition, since the surface of the silica particles is acidic, when the rubber composition is vulcanized, the basic material used as a vulcanization accelerator is adsorbed, so that the vulcanization is not sufficiently performed and the elastic modulus does not increase.

To solve these problems, various silane coupling agents have been developed. For example, Japanese Unexamined Patent Publication No. 50-29741 describes that a silane coupling agent is used as a reinforcing agent. However, this silane coupling agent-based reinforcing agent was also insufficient to achieve high breaking properties, workability and workability of the rubber composition. In addition, Japanese Patent Application Publication No. 51-20208 discloses a rubber composition using a silica silane coupling agent as a reinforcing agent. By reinforcing the silica silane coupling agent system, the reinforcement of the rubber composition can be remarkably improved and the fracture characteristics can be improved. However, the drawback of remarkably deteriorating the flowability at the time of unvulcanization of the rubber composition results in deterioration of workability and processability. have.

The drawback of the prior art by using such a silane coupling agent is due to the following mechanism. That is, when the mixing temperature of the rubber is low, the silanol groups on the silica surface and the silane coupling agent do not sufficiently react, and as a result, the reinforcing effect is not obtained. In addition, the dispersion of silica into the rubber is not good, and the low heat generation property, which is an advantage of the silica compound rubber, is caused. The alcohol produced by the partial reaction between the silanol group and the silane coupling agent on the silica surface is not completely volatilized due to the low mixing temperature, and the alcohol present in the rubber vaporizes in the extraction process to generate blisters.

On the other hand, when the high temperature mixing with the mixing temperature of 150 degreeC or more is performed, the silanol group and silane coupling agent of a silica surface will fully react, and a reinforcement property will improve as a result. In addition, the dispersion of silica into rubber is improved, a low heat-generating rubber composition is obtained, and the generation of blisters during the extrusion process is also suppressed. In this temperature range, however, the gelation of the polymer derived from the silane coupling agent occurs simultaneously, and the Mooney viscosity is greatly increased, and in reality, it is impossible to perform the processing in the post process.

Therefore, when using a silane coupling agent together with silica, it is necessary to carry out temperature mixing below 150 degreeC in multiple steps, and the remarkable fall of productivity is unavoidable.

Summary of the Invention

The present invention is to solve the above problems of the prior art to suppress the gelation of the polymer by the silane coupling agent when mixing at a high temperature of 150 ℃ or more and to efficiently react the silica and silane coupling agent without lowering the workability and low heat generation To provide a rubber composition and a pneumatic tire that can improve the performance and wear resistance.

In order to solve the above problems, the present inventors conducted extensive research on silica-containing rubber compositions, and as a result, by specifying the distribution of bound sulfur in each component in the silane coupling agent, an increase in the Mooney viscosity of the rubber composition was suppressed even when mixed at a temperature higher than 150 ° C. It has also been found that a rubber composition excellent in low heat generation and workability is obtained. In addition, by mixing a specific amount of a specific dispersion modifier with respect to silica, it has been found that the dispersibility of the silica into the rubber is greatly improved, the Mooney viscosity of the rubber composition is lowered, and the low calorific property and the wear resistance are improved. .

That is, the present invention is as follows.

1. 10 to 85 parts by weight of silica, preferably 20 to 65 parts by weight of the following general formula (I), based on 100 parts by weight of at least one rubber component selected from the group consisting of natural rubber and diene-based rubber

(C _n H _2n + ₁ O) ₃ Si-(CH ₂ ) _m -S _y- (CH ₂ ) _m -Si (C _n H _2n + ₁ O) ₃ (I)

In the above formula as a silane coupling agent represented by (wherein n is an integer of 1~3, m is an integer of 1-9, y has a distribution of one or more integer) -S _y - is the distribution of food,

(S ₁ + S ₂ + S ₃ + S ₄ ) / (S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) ≥ 0.85

1 to 20% by weight, preferably 3 to 15% by weight, of the silane coupling agent that satisfies the relationship indicated by

(1) hexamethyldisilazane,

(2) hydrogen silicone oil represented by formula (II),

(Ⅱ)

(3) alkoxy modified silicone oil or amino modified silicone oil represented by formula (III),

(Ⅲ)

In formulas (II) and (III), R represents an alkyl or phenyl group having 1 to 3 carbon atoms, p and q each represent the number of units, and 1 ≦ p + q ≦ 200, q / (p + q) ≧ 0.15, X ¹ is an alkoxy group having 1 to 3 carbon atoms or -R ¹ NR ² R ³ or -R ¹ NHR ⁴ NR ² R ³ and R ¹ and R ⁴ are-(CH ₂ ) n-(where n is 1,2 or 3 ), R ² and R ³ each independently represent a hydrogen atom, an amino group having 1 to 36 carbon atoms or a phenyl group.)

(4) a nitrogen-containing carbonyl compound represented by formula (IV),

(Ⅳ)

Wherein R ^a to R ^j each represent a hydrogen atom, a straight or branched saturated, unsaturated aliphatic hydrocarbon, aromatic hydrocarbon or alicyclic hydrocarbon having 1 to 20 carbon atoms, and

(5) Amine compound represented by general formula (V)

(Ⅴ)

(Wherein R ^K is an alkyl group having 1 to 36 carbon atoms, an alkenyl group or an alkoxy group and a hydroxy substituent, benzyl group, benzyl group substituted with an alkyl group or alkenyl group having 4 to 36 carbon atoms, represented by the following general formula (VI) Group and R ^P and R ^t independently represent an alkyl group having 1 to 36 carbon atoms or an alkenyl group, benzyl group, cyclohexyl group and hydroxy substituents thereof.

(Ⅵ)

In formula, R <^5> represents a C1-C36 alkyl group or alkenyl group, R <^6> represents an ethylene group or a propylene group, X <^2> represents hydrogen, a C1-C18 alkyl group, an alkenyl group, an alkyloyl group, or an alkenylyl group, A represents an alkylene group or a hydroxy alkylene group having 2 to 6 carbon atoms, and m is an integer of 1 to 10, and when m is 2 or more, each A may be the same or different and n is an integer of 1 to 10.)

It is a rubber composition which mix | blends at least 1 sort (s) of dispersion improving agent of the silica chosen from the group which consists of 1-15 weight% with respect to silica amount, Preferably it is 2-15 weight%.

2. In the rubber composition of 1, the -S _y -distribution in the formula is

(S ₁ + S ₂ + S ₃ ) / (S ₄ or more components) ≥ 0.45

It is a rubber composition that satisfies the relationship indicated by and has a S ₃ component of 20% or more.

3. In the rubber composition of the above 1 -S _y

(S ₁ + S ₂ + S ₃ ) / (S ₄ or more components) ≥ 0.55

It is a rubber composition that satisfies the relationship indicated by and has a S ₃ component of 30% or more.

4. In the rubber composition according to the above 1, 2 or 3, it is a rubber composition in which carbon black is blended at 80 parts by weight or less, preferably 20 to 60 parts by weight, based on 100 parts by weight of the rubber component.

5. In the rubber composition according to the above 1, 2 or 3, anhydrous sodium sulfide (Na ₂ S) and sulfur (S) are reacted in a polar solvent in an inert gas atmosphere in a molar ratio of 1: 1 to 1: 2.5. Sodium sulfide was obtained, and this sodium polysulfide was added to the following general formula

(Ⅶ)

Halogenoalkoxysilane represented by (wherein R ⁷ and R ⁸ are each an alkyl group having 1 to 3 carbon atoms, R ⁹ is a divalent hydrocarbon group having 1 to ⁹ carbon atoms, X ³ is a halogen atom and k is an integer of 1 to 3). In addition, the compound obtained by making it react in inert gas atmosphere is a rubber composition used as said silane coupling agent.

6. Pneumatic tire, characterized in that the rubber composition of 1, 2, 3, 4 or 5 as the tread rubber.

The present invention relates to a rubber composition blended with silica using a silane coupling agent and to an air tire using the same. Specifically, silica inhibits gelation of the polymer by the silane coupling agent and does not deteriorate workability when mixed at a high temperature of 150 ° or more. The present invention relates to a rubber composition capable of efficiently reacting with a silane coupling agent and improving low heat generation and abrasion resistance, and an air tire using the same.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

In the present invention, as the rubber component, natural rubber (NR) or synthetic rubber may be used alone or in combination thereof. Examples of the synthetic rubbers include synthetic polyisoprene rubber, polybutadiene rubber (BR), styrene butadiene rubber (SBR), butyl rubber and butyl halide rubber.

As the silica used in the present invention, synthetic silica by precipitation method is used. Specifically, Nipsil AQ manufactured by Nippon Silica Co., Ltd., ULTRASIL VN3, BV3370GR manufactured by Degussa, Germany, RP1165MP, Zeosil 1165GR, Zeosil 165MP, Zeosil 175MP, manufactured by Long Plansa, Hisil 233, Hisil 210, Hisil 255, etc. (all Brand name), but the present invention is not particularly limited.

The compounding quantity of silica is 10-85 weight part with respect to 100 weight part of said rubber components, Preferably it is 20-65 weight part. If the blending amount of silica is less than 10 parts by weight, it is not reinforcing, and if it is more than 85 parts by weight, workability such as warming up and extrusion deterioration is caused, which is not preferable. In view of low heat generation and workability, the blending amount of silica is preferably 20 to 65 parts by weight.

The silane coupling agent used in the present invention is represented by the following general formula (I),

(C _n H _{2n + 1} O) ₃ Si- (CH ₂ ) _m -S _y- (CH ₂ ) _m -Si (C _n H _{2n + 1} O) ₃ (I)

In the above formula as a silane coupling agent represented by (wherein n is an integer of 1~3, m is an integer of 1-9, y has a distribution of one or more integer) -S _y - is the distribution of food,

(S ₁ + S ₂ + S ₃ + S ₄ ) / (S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) ≥ 0.85

Preferably the following formula,

(S ₁ + S ₂ + S ₃ + S ₄ ) / (S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) ≥ 1.0

It is required to satisfy the relationship indicated by. If the distribution ratio is less than 0.85, the inhibitory effect on the gelation of the polymer is not obtained when mixing at a high temperature of 150 ° C. or higher, and the Mooney viscosity is significantly increased, resulting in poor workability. Here, the S _y -distribution in the above formula is preferably a value of (S ₁ + S ₂ + S ₃ ) / + (S ₄ or more components) of 0.45 or more and S ₃ component of 20% or more, more preferably (S ₁ + S ₂ + S ₃₎ / a + (S ₄ or more component), the value is 0.55 or more, or the component S ₃ is 30% or more. When the value of the above formula is less than 0.45, the inhibitory effect on the gelation of the polymer is not sufficiently obtained at high temperature mixing of 150 ° C. or higher, and the Mooney viscosity is increased, resulting in poor workability. In addition, when the S ₃ component is 20% or more, the S ₁ and S ₂ components which do not have a coupling action are relatively small, so that the reinforcement is better and the wear resistance is not inhibited.

The silane coupling agent is 1 to 20% by weight, preferably 3 to 15% by weight based on the weight of silica. If the blending amount of the silane coupling agent is less than 1% by weight, the coupling effect is small, whereas if the amount of the silane coupling agent is greater than 20% by weight, it causes gelation of the polymer, which is not preferable.

As a dispersion improving agent of silica used for this invention, (1) hexamethyldisilazane, (2) the hydrogen silicone oil represented by the said General formula (II), (3) the alkoxy modified silicone oil of the said General formula (III), or It is preferable that it is at least 1 sort (s) chosen from the group which consists of an amino modified silicone oil, (4) the nitrogen-containing carbonyl compound represented by the said General formula (IV), and (5) the amine compound represented by the said General formula (V).

When the degree of polymerization (p + q) of the siloxane bond in the hydrogen silicone oil, the alkoxy modified silicone oil or the amine modified silicone oil represented by the above-mentioned general formula is greater than 200, the effect of lowering the compound Mooney viscosity and the exotherm The improvement effect of a characteristic also becomes small. Therefore, the polymerization degree (p + q) of the siloxane bond is required to be 200 or less, preferably 100 or less. If q / (p + q) is less than 0.15, improvement of dispersibility into silica rubber and efficient vulcanization are not performed. Therefore, q / (p + q) is required to be 0.15 or more. Preferably it is 0.3 or more.

In the amino-modified silicone oil, one of the primary amino group, the secondary amino group, and the tertiary amino group may be used as the bonding form of the amino group. However, when carbon black is used, the secondary amino group and the tertiary amino group are preferred, or the tertiary amino group. More preferred. When used in combination with carbon black, hydrogen bonded to the nitrogen atom promotes the vulcanization reaction, so the scorch time is shortened, which is not preferable for processing.

The nitrogen-containing carbonyl compound used in the present invention may be used alone or in combination of two or more thereof. Specific examples of the nitrogen-containing carbonyl compound include urea, 1, 1-dimethylurea, 1, 3-dimethylurea, tetramethylurea, 1, 3-diphenylurea, acetamide, stearic acid hydrazide, and the like. It is most effective when used.

In the formula (V) of the amine compound used in the present invention, R ^K is specifically methyl, ethyl, propyl, lauryl, stearyl, lauroyl aminoethylene, stearoyloxyethylene and acryl. Iloxy propylene group, methacroyl oxypropylene group, 2-hydroxymethyl group, 2-hydroxy dodecyl group, benzyl group, cyclohexyl group, etc. are mentioned.

Specific examples of R ^P and R ^t include a methyl group, an ethyl group, a lauryl, a stearyl group, a vinyl group, an aryl group, a 3-aryloxy-2-hydroxypropyl group, a benzyl group, and a hydroxyethyl group.

Specific examples of R ⁵ in formula (VI) include methyl group, ethyl group, lauryl group, stearyl group, vinyl group and aryl group.

Specific examples of X ² include hydrogen, ethyl group, lauryl group, stearyl group, vinyl group, aryl group, lauroyl group, stearoyl group, acryloyl group and methacryloyl group.

Specific examples of the amine compound used in the present invention include N, N, N-trioctylamine, N, N-dimethyl, -N-decylamine, N, N-dimethyl-N-myristylyl, N, N-dilauryl -N-methylamine, N, N-dimethyl-N-octadecenylamine, N, N-dimethyl-N-hexadecenylamine, N, N-dimethyl-N-methacryloxypropylamine, N-methyl- N, N-divinylamine, N, N, N-trilaurylamine, N, N, N-tristearylamine, N, N-dimethyl-N-laurylamine, N, N-dimethyl, -N -Stearylamine, N-methyl-N, N-dilaurylamine, N-methyl-N, N-distearylamine, N, N-dibenzyl-N-stearylamine, N-benzyl-N, N -Dilaurylamine, N, N-diallyl-N-stearylamine, N, N-diallyl-N-laurylamine, N, N-dimethyl-N-lauroyloxyethylamine, N, N- Dimethyl-N-stearoyloxyethylamine, N, N-dimethyl-N'-lauroyl-propylamine, N, N-dihydroxyethyl-N-stearylamine, N, N-dihydroxyethyl -N-laurylamine, N, N-dihydroxyethyl-N- (2-hydroxydodecyl) amine , N, N-polyoxyethylene-N-stearylamine, N, N-di (2-hydroxy-3-allyloxypropyl) -N-hexadecylamine, N, N-di (-2-hydroxy -3-allyloxypropyl) -N-oradecylamine, N, N-di- (2-hydroxy-3-acryloxycarbonyl) propyl-N-hexadiylamine, N, N-di (2hydroxy -3-acryloxycarbonyl) propyl-N-octadecylamine, N, N-di (-5-hydroxy-3,7-dioxy-9-decyl-1 yl) -N-octadecylamine, acrylic acid And esterified products of methacrylic acid and fatty acid esterified products.

Preferably, R ^k and R ^p represent a methyl group and R ^t represents a dimethylalkylamine which represents an alkyl group having 12 to 36 carbon atoms, and preferably dimethylstearylamine in terms of flash point, low heat generation and dispersion improvement.

Moreover, it is preferable that the molecular weight of the amine compound used by this invention is 180 or more. If the molecular weight of the amine compound is lower than 180, the flash point is lowered and there is a risk of ignition in the processing step, which is not preferable.

The compounding quantity of the said dispersion improving agent of silica is 1-15 weight% with respect to a silica, Preferably it is 2-15 weight%. When the blending amount is less than 1% by weight, the Mooney viscosity of the target rubber composition does not decrease, and low heat and wear resistance are not improved.In addition, when the content exceeds 15% by weight, for example, the dispersion improvement effect and the low heat generation effect are saturated and the scorch time. Because of this shortening and the problem of pre-vulcanization (scoring) or the effect as a plasticizer greatly increases, the wear resistance is inversely lowered, which is not preferable.

As the carbon black used as the reinforcing filler in the present invention, SAF, ISAF, HAF grade can be preferably used, but is not particularly limited.

It is preferable that the compounding quantity of carbon black is 80 weight part or less with respect to 100 weight part of said rubber components. When the compounding quantity of carbon black exceeds 80 weight part, low heat generation property will deteriorate significantly. 25-60 weight part is preferable at the point of reinforcement property and low heat generation property.

In the rubber composition of the present invention, in addition to the rubber component, silica, silane coupling agent, and carbon black, compounding agents commonly used in the rubber industry such as softeners, anti-aging agents, vulcanizing agents, vulcanization accelerators, vulcanization accelerators, etc. as necessary. Can be suitably blended.

In order to effectively show the characteristics of the rubber composition of the present invention, the mixing temperature is preferably 150 ° C or more and 180 ° C or less. This is because when the mixing temperature is lower than 150 ° C, the silane coupling agent does not sufficiently react and blisters are generated during extrusion. On the other hand, when the mixing temperature is higher than 180 ° C, gelation of the polymer also occurs and the Mooney viscosity is increased, which is undesirable in processing.

In the rubber composition of the present invention, a working structure of how the polymer is not gelled and the low exothermicity is improved even at a mixing temperature of 150 ° C. or higher will be described based on the consideration and examination results.

Long chain sulfur of S ₆ or more in the molecule was analyzed by high-performance liquid chromatography after heating in a oven at 150 ° C. for 2 hours in a silane coupling agent (trade name: Si69, German Degus Co., Ltd.) commonly used in the tire industry. It was found that the component having a decreased compared to the original product and increased the component with free ions and short chain sulfur below S ₄ . In other words it is considered that the cracking component with S ₆ or more long chain sulfur molecules hameuroseo during the heating of the high temperature. It is expected that the gelation of the polymer occurs at high temperature mixing due to the generation of radicals upon decomposition or the decomposition products act as sulfur feeders. Therefore, as a result of the thorough review under the assumption that if the component having long chain sulfur in the silane coupling agent is reduced in advance, the gelation of the polymer is suppressed at the time of high temperature mixing above 150 ° C, the short chain in the component having various lengths of chain sulfur in the molecule As a result of the ratio of the sulfur component to a predetermined value or more, the gelation of the polymer is actually suppressed and the mixture is mixed at a high temperature, so that the reaction between the silanol groups and the silane coupling agent on the silica surface is sufficient to improve the dispersibility of the silica into the rubber and lower the heat generation property. It was found that this was obtained.

In addition, in the case of a dispersion modifier such as hydrogen silicone oil, a hydrogen atom bonded to a silicon atom has activity, and in the case of an alkoxy-modified silicone oil, dehydration is performed between silanol formed by hydrolysis of the alkoxy moiety and silanol groups on the silica surface. Condensation reaction occurs, and in the case of amino-modified silicon oil, nitrogen-containing carbonyl compound or amine compound, the nitrogen atom in the molecule has a high ability to form hydrogen bonds with silanol groups on the silica surface and the silanol groups on the silica surface Therefore, it is thought that silica particles prevent aggregation of each other. For example, in the case of hydrogen silicone oil and alkoxy modified silicone oil, the alkyl moiety bound to these oils has high affinity with rubber, and in the case of amino modified silicone oil, nitrogen-containing carbonyl compound or amine compound Since the reaction between the play and these compounds is chemical adsorption, it is believed that both of them have an effect of improving the dispersion of silica into the rubber in the low temperature region of the rubber mixture, lowering the Mooney viscosity of the rubber composition, and improving the low heat generation and wear resistance. .

Example

Hereinafter, an Example demonstrates this invention further more concretely.

Shown in Table 5 below is a common basic blending ratio,

Various alkoxy-modified silicone oil formulations are shown in Tables 6 and 7 below.

Various amino-modified silicone oil formulations are shown in Tables 8 and 9 below.

Various hydrogen silicone oil formulations are shown in Tables 10 and 11 below.

Various nitrogen-containing carbonyl compound-based formulations are shown in Tables 12 and 13 below.

Various amine compound-based formulations are shown in Tables 14 and 15 below.

Hexamethyldisilazane formulations are shown in Tables 16 and 17 below.

According to various rubber compositions were prepared. The evaluation results were written together in the table, respectively.

Moreover, the various silane coupling agents used for such compounding are represented by the following formula,

(C ₂ H ₅ O) ₃ Si (CH ₂ ) ₃ -S _y- (CH ₂ ) ₃ Si (C ₂ H ₅ O) ₃ is represented by -S _y -in the distribution shown in Table 1 below Relationship.

(Analysis of -S _y -distribution)

As shown in Table 1, each chain sulfur component (-S _y distribution ratio of the silane coupling agent used in each of the examples and the comparative examples was determined by high-performance liquid chromatography- (HPLC) specifically shown below). It was calculated as (%).

(Condition of PLC Analysis)

HPLC: HLC-8020 manufactured by Tosoh Corporation

UV Detector: Doso Co., Ltd. UV-8110 (254mm)

Recorder: Doso Co., Ltd. Super System Controller SC-8010

Column: Tosko Corporation TSKgel ODS-80T _M CTR (inner diameter: 4.6 mm / length: 10 cm)

Measuring Temperature: 25 ℃

Sample concentration: 6mg / 10cc acetonitrile solution

Sample injection volume: 20 μl

Elution condition: Flow rate 1cc / min

Acetonitrile: eluted with a mixed solution of water = 1: 1 for 2 minutes, and then eluted with a gradient of acetnitrile at 100% over 18 minutes.

Analysis of the silane coupling agent (Si69, manufactured by Degussa, Germany) of Sample A in Table 1 under the above conditions was performed. In the vicinity, the peaks of -S _2- , -S _3- , -S _4- , -S _5- , -S _6- , -S _7- , -S _8- , -S _9- , are separated. Measure each peak area and calculate the (S ₁ + S ₂ + S ₃ + S ₄ ) and (S ₄ + S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) values, and also calculate (S ₁ + S ₂ + S ₃ + S ₄ ) / (S ₄ + S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) was 0.73.

In addition, the value of (S ₁ + S ₂ + S ₃ ) and (S ₄ + S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) are calculated and (S ₁ + S ₂ + S ₃ ) / ( S ₄ + S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) was 0.225. In addition, the peak area ratio of S ₃ was 15.9%. Each value was similarly calculated | required about the samples B-F in Table 1, too.

* 1 Si 69 made by German company

* 2 Samples B to F

(Preparation of various silane coupling agents)

ㆍ Preparation of Sample A

Si 69 manufactured by Degussa, Germany was used.

ㆍ Preparation of Samples B, C, E, F

Anhydrous sodium sulfide and sulfur were synthesized according to the method of Japanese Patent Laid-Open No. 7-228588 in the following molar ratios.

Sample B 1: 2.5

Sample C 1: 2.5

Sample E 1: 2

Sample F 1: 1

ㆍ Preparation of Sample D

It was synthesized by oxidizing r-mercaptopropyltriethoxysilane using manganese dioxide as a catalyst according to the method described in EP 0 732 363 A1.

(Types of various dispersion modifiers)

Various dispersion improving agents used in the formulation of the rubber composition are as follows.

ㆍ Various alkoxy modified silicone oils are shown in Table 2,

Various amino modified silicone oils are shown in Table 3 below.

ㆍ Various hydrogen silicone oils shown in Table 4,

Various nitrogen-containing carbonyl compounds are shown in Tables 12-13,

ㆍ Various Amine Compounds in Tables 14-15

• Hexamethyldisilazane is shown to the following 16-17, respectively.

(evaluation)

The obtained rubber composition was evaluated for abrasion resistance, Mooney viscosity, hysteresis loss characteristics (pyrogenicity) and the presence of blister generation by the following evaluation methods. Next, using the obtained rubber composition as a tread, a tire of size 185 / 60R 14 was produced and the rolling resistance was evaluated.

(1) wear resistance

The abrasion resistance index showing wear resistance is measured at ground pressure of 5Kg / Cm ² and sliding rate of 40% by the method according to BS (British Standard) standard 903 (part A) D method using a Lambbourn wear tester. Calculated.

Abrasion Resistance Index = (loss weight of control / loss weight of test specimen) × 100

The larger this index, the better the wear resistance.

(2) Mooney viscosity

According to JIS K6300, it was measured by 1 minute of preheating, 4 minutes of measurement, and temperature of 130 DEG C and represented by an index compared with the control. The smaller the index, the lower the Mooney viscosity and the better the processability.

(3) Measurement of hysteresis loss characteristic (pyrogenicity)

Internal loss (tanδ) was measured using a viscoelastic spectrometer manufactured by Iwamoto Co., Ltd. under conditions of 1% dynamic field stress, frequency 50H _Z and 60 ° C. In addition, the test piece used the slab sheet of thickness about 2mm, width 5mm, and the initial load was 160g with the clamp distance between 2Cm. The value of tan δ is expressed as an index compared to the control. The smaller the index value, the lower the hysteresis loss characteristic and the lower the fever.

(4) Measurement of rolling resistance performance

The starting tire was brought into contact with a drum having an internal pressure of 2.0 kg / cm ² , a load of 440 kg, and a rim of 6 JJ on a drum having an outer diameter of 1.7 m to rotate the drum, and the drum was rotated after rising to a speed of 120 km / hr. The value calculated by the moment was evaluated by the following formula. The formula expresses the control as an exponent as 100, with the larger being preferred.

Index = ((tire moment of inertia of the control) / (moment of inertia of the test tire)] × 100

In the above evaluations, in Examples 1 to 12 and Comparative Examples 2 to 7, Comparative Example 1 was used in Example 13 and Comparative Examples 9 to 10, and Comparative Example 8 was used. In Examples 14 to 15, rubber of Comparative Example 11 was used. The composition was taken as a control.

In Examples 16 to 28 and Comparative Examples 13 to 18, Comparative Example 12 was used, Comparative Example 19 was used in Example 29 and Comparative Examples 20 to 21, and rubber compositions of Comparative Example 22 were used in Examples 30 to 31. As a control.

In Examples 32 to 42 and Comparative Examples 24 to 29, Comparative Example 23 was compared to Comparative Example 30 in Examples 43 and Comparative Examples 31 to 32, and rubber compositions of Comparative Example 33 were compared to Examples 44 to 45. It was made with water.

In Examples 46 to 59 and Comparative Examples 35 to 37, Comparative Example 34 was used, Comparative Example 38 was used in Examples 60 and 39 to 40, and rubber compositions of Comparative Example 41 were prepared in Examples 61 to 62. Each was used as a control.

In Examples 63 to 73 and Comparative Examples 43 to 45, Comparative Example 42 was used, Comparative Examples 46 were used in Examples 74 and 47 to 48, and in Examples 75 to 76, the rubber composition of Comparative Example 49 was used. Was used as a control.

In Examples 77 to 85 and Comparative Examples 51 to 54, Comparative Example 50 was used, Comparative Examples 55 were used in Examples 86 and 56 and 57, and rubber compositions of Comparative Examples 58 were prepared in Examples 87 to 88. As a control.

(5) presence or absence of blister occurrence

It was measured by Rheograph 2000 by Gottfert. It measured at 120 degreeC using the die | dye of an extrusion hole of 9 mm x 2 mm rectangle, and thickness 2mm. Extrusion was carried out at a preheating time of 3 minutes at an extrusion speed of 10 mm / sec of the piston and visually determined whether blisters occurred in the extract.

Weight of ingredients Rubber content 100 Silica variable amount Carbon black Variable amount aromatic oil 20 Stearic acid 2 Silane coupling agent Variable amount Various dispersion improving agent Variable amount Zinc oxide 3 Anti-aging agent 1 Vulcanization accelerator 1. 5 Sulfur 1. 5

* 1 N-phenyl-N'-isopropyl-p-phenylenediamine

* 2 N-oxydiethylene-2-benzothiazolesulfenamide

Since the rubber composition of the present invention uses a silane coupling agent having a specific sulfur distribution and a dispersion improving agent of silica, the generation of blisters is suppressed in the process of extruding when mixing at a high temperature of 150 ° C. or higher, and the polymer of the silane coupling agent Since gelation is suppressed and reaction of a silica and a silane coupling agent is performed efficiently without reducing workability, it is widely used for the various air tires which improve the dispersibility of the silica in rubber, and are excellent in abrasion resistance and low heat generation property.

Claims (18)

10 to 85 parts by weight of silica with respect to 100 parts by weight of at least one rubber component selected from the group consisting of natural rubber and diene synthetic rubber and the following general formula (I) (C _n H _{2n + 1} O) ₃ Si-(CH ₂ ) _m -S _y- (CH ₂ ) _m -Si (C _n H _{2n + 1} O) ₃ (I) The distribution of the S _y of the above formula as a silane coupling agent represented by (wherein, n is an integer of 1~3, m is an integer of 1-9, y has a distribution of one or more integer) food, (S ₁ + S ₂ + S ₃ + S ₄ ) / (S ₄ + S ₅ + S ₆ + S ₇ + S ₈ + S ₉ ) ≥ 0.85 The silane coupling agent which satisfies the relationship shown by 1-20weight% with respect to the quantity of silica, (1) hexamethyldisilazane; (2) hydrogen silicone oil represented by formula (II), (Ⅱ) (3) alkoxy modified silicone oil or amine modified silicone oil represented by formula (III), (Ⅲ) (In formulas (II) and (III), R represents an alkyl or phenyl group having 1 to 3 carbon atoms, p and q each represent the number of units, and 1 ≦ p + q ≦ 200 and q / (p + q) ≧ 0.15 X ¹ is an alkoxy group having 1 to 3 carbon atoms, or -R ¹ NR 2 R 3 or -R ¹ NHR 4 NR 2 R 3, R 1 and R 4 are-(CH 2) n-(where n is 1,2 or 3), R 2 and R 3 are Each independently represents a hydrogen atom, an alkyl group having 1 to 36 carbon atoms or an amino group which is a phenyl group) (4) a nitrogen-containing carbonyl compound represented by formula (IV) (Ⅳ) (Wherein R ^a to R ^j each represent a hydrogen atom, a straight or branched saturated, unsaturated aliphatic hydrocarbon, aromatic hydrocarbon, or alicyclic hydrocarbon having 1 to 20 carbon atoms) (5) Amino compound represented by general formula (V) (Ⅴ) (Wherein R ^K is an alkyl group having 1 to 36 carbon atoms, an alkenyl group or an alkoxy group and a hydroxy substituent, benzyl group, benzyl group substituted with an alkyl group or alkenyl group having 4 to 36 carbon atoms, represented by the following general formula (VI) Group and R ^P and R ^t independently represent an alkyl group having 1 to 36 carbon atoms or an alkenyl group, benzyl group, a cyclohexyl group, and a hydroxy substituent thereof. (Ⅵ) Wherein R ⁵ represents an alkyl group or alkenyl group having 1 to ³⁶ carbon atoms, R ⁶ represents an ethylene group or a propylene group, X ² represents hydrogen, an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an alkyloyl group or an alkenylyl group. A represents an alkylene group or a hydroxyalkylene group having 2 to 6 carbon atoms, m is an integer of 1 to 10, when m is 2 or more, each A may be the same or different, and n is an integer of 1 to 10.) A rubber composition comprising 1 to 15% by weight of a dispersion improving agent of at least one type of silica selected from the group consisting of silica. The rubber composition according to claim 1, wherein the compounding amount of silica is 20 to 65 parts by weight based on 100 parts by weight of the rubber component. The rubber composition according to claim 1, wherein the compounding amount of the silane coupling agent is 3 to 15% by weight based on the amount of silica. The rubber composition according to claim 1, wherein the dispersion improving agent of silica is 2 to 15% by weight based on the amount of silica. The method of claim 1, wherein the -S _y -distribution in the formula is (S ₁ + S ₂ + S ₃ ) / (S ₄ or more components) ≥ 0.45 A rubber composition that satisfies the relationship indicated by and has a S ₃ component of 20% or more. The method of claim 1, wherein the -S _y -distribution in the formula is (S ₁ + S ₂ + S ₃ ) / (S ₄ or more components) ≥ 0.55 A rubber composition that satisfies the relationship indicated by S ₃ and is 20% or more. The rubber composition according to claim 1, further comprising carbon black at 80 parts by weight or less with respect to 100 parts by weight of the rubber component. The rubber composition according to claim 5, wherein carbon black is blended at 80 parts by weight or less with respect to 100 parts by weight of the rubber component as a filler for reinforcement. The rubber composition according to claim 6, wherein carbon black is blended at 80 parts by weight or less with respect to 100 parts by weight of the rubber component as a filler for reinforcement. The rubber composition according to claim 7, wherein carbon black is blended in an amount of 20 to 60 parts by weight based on 100 parts by weight of the rubber component as a filler for reinforcement. The sodium sulfide according to claim 1 is reacted with anhydrous sodium sulfide (Na ₂ S) and sulfur (S) in an inert gas atmosphere in a polar solvent in a molar ratio of 1: 1 to 1: 2.5 to obtain sodium polysulfide. Sodium sulfide to the following general formula (Ⅶ), (Ⅶ) Halogenoalkoxy represented by (wherein R ⁷ and R ⁸ are each an alkyl group having 1 to 3 carbon atoms, R ⁹ is a divalent hydrocarbon group having 1 to ⁹ carbon atoms, X ³ is a halogen atom and k is an integer of 1 to 3). A rubber composition wherein a compound obtained by adding silane and reacting under an inert gas atmosphere is used as the silane coupling agent. 6. The sodium sulfide according to claim 5, wherein anhydrous sodium sulfide (Na ₂ S) and sulfur (S) are reacted in a polar solvent in an inert gas atmosphere in a molar ratio of 1: 1 to 1: 2.5 to obtain sodium polysulfide. A rubber composition in which a compound obtained by adding sodium sulfide to a halogenoalkoxysilane represented by the general formula of claim 11 and reacting in an inert gas atmosphere is used as the silane coupling agent. 7. The sodium sulfide according to claim 6 is reacted with anhydrous sodium sulfide (Na ₂ S) and sulfur (S) in a polar solvent in an inert gas atmosphere in a molar ratio of 1: 1 to 1: 2.5 to obtain sodium polysulfide. A rubber composition in which a compound obtained by adding sodium sulfide to a halogenoalkoxysilane represented by the general formula of claim 11 and reacting in an inert gas atmosphere is used as the silane coupling agent. Pneumatic tire using rubber composition of claim 1 as tread rubber Pneumatic tire using rubber composition of claim 5 as tread rubber Pneumatic tire using rubber composition of claim 6 as tread rubber Pneumatic tire using rubber composition of claim 7 as tread rubber Pneumatic tire using rubber composition of claim 11 as tread rubber