JP2003321578A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an especially high-performance pneumatic tire satisfying all of wet grip performances, abrasion resistance and maneuverability at high levels. <P>SOLUTION: The pneumatic tire comprises a rubber composition comprising (A) a rubber component having (a) an ethylenically unsaturated nitrile monomer unit, (b) an aromatic vinyl monomer unit and (c) a conjugated diene monomer unit and containing 5-45 wt.% of the unit (a) and 10-50 wt.% of the aromatic vinyl monomer unit (b) based on the total amount of the units (a), (b) and (c) and (B) at least one kind of filler selected from carbon black and a white filler and used as a tread rubber. The rubber composition has ≥12.0 MPa dynamic storage modulus at 30°C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pneumatic tire. More specifically, the present invention provides, as a rubber component,
The present invention relates to a pneumatic tire having high kinetic performance, which is made of a conjugated diene-based copolymer rubber having a nitrile group having an improved affinity with a reinforcing filler, and which is particularly used for high performance or sports.

[0002]

2. Description of the Related Art Generally, grip performance is a particularly important required characteristic in a high-movement pneumatic tire. Good grip performance means good acceleration performance and braking performance, and the vehicle has good steering stability and can travel at high speed. Conventionally, in order to obtain a high grip performance as a high exercise performance, a method of using a styrene-butadiene copolymer rubber having a high styrene content as a rubber component, a method of highly filling and blending a softening agent and carbon black, and a small particle diameter A method of blending carbon black is known. However, in these methods, there is a problem that the wear resistance becomes poor and the initial high exercise performance is deteriorated at an early stage. If natural rubber or polybutadiene rubber is blended in order to improve wear resistance, steering stability is significantly impaired. Furthermore, it is required to achieve both steering stability and wet grip performance (braking performance on wet road surface). Therefore, the performance requirements for the rubber composition used for the tread of a high-motility pneumatic tire are desired to satisfy all of the wet grip performance as well as the steering stability and wear resistance.

As a method for obtaining a rubber composition having improved wet grip performance, a method of using silica instead of carbon black as a reinforcing filler has already been carried out.
However, in silica, particles tend to aggregate due to hydrogen bonds of silanol groups, which are surface functional groups, and it is difficult to disperse the silica particles in the rubber. Therefore, the filler originally has it. There is a problem that the reinforcing effect and the like cannot be obtained sufficiently.

[0004]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention provides a pneumatic tire having a high level of steering stability, wet grip performance and wear resistance, particularly a high performance or sports type passenger car. An object of the present invention is to provide a pneumatic tire for use.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a tread rubber containing a specific conjugated diene copolymer rubber containing a nitrile group is used as a tread rubber. It has been found that the purpose can be achieved by using a rubber composition in which a filler is added to the components. The present invention has been completed based on such findings. That is, the present invention has (A) (a) an ethylenically unsaturated nitrile monomer unit, (b) an aromatic vinyl monomer unit, and (c) a conjugated diene monomer unit, and Based on the total amount of the above (a), (b) and (c) units,
A rubber component containing 10% by weight or more of a conjugated diene-based copolymer rubber containing (a) a unit of 5 to 45% by weight and (b) an aromatic vinyl monomer unit of 10 to 50% by weight, and (B) a carbon black. And a rubber composition containing at least one kind of filler selected from a white filler, and a rubber composition having a dynamic storage elastic modulus at 30 ° C. of 12.0 MPa or more of the rubber composition, a tread rubber. A pneumatic tire characterized by being used as.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the pneumatic tire of the present invention, the rubber composition used for the tread needs to have a dynamic storage elastic modulus at 30 ° C. of 12.0 MPa or more. If it is less than 12.0 MPa, the steering stability will decrease. In the tread rubber composition, the rubber component containing the conjugated diene-based copolymer rubber used as the component (A) is as follows. The conjugated diene-based copolymer rubber comprises (A) (a) an ethylenically unsaturated nitrile monomer unit, (b) an aromatic vinyl monomer unit, and (c) a conjugated diene monomer unit. In addition, based on the total amount of the units (a), (b) and (c), it contains 5 to 45% by weight of the unit (a).

When the content of the ethylenically unsaturated nitrile unit which is the unit (a) is less than 5% by weight, the dispersibility of the filler becomes poor and the abrasion resistance may not be sufficiently improved. On the other hand, if this content exceeds 45% by weight, the glass transition point (Tg) of the conjugated diene-based copolymer rubber becomes too high, and the properties as a rubber elastic body are lost. The content of the ethylenically unsaturated nitrile unit is preferably 8 to 35% by weight, and particularly preferably 9 to 20% by weight.

The content of the aromatic vinyl monomer unit which is the unit (b) is 10 to 50% by weight. If this content is less than 10% by weight, the abrasion resistance of the vulcanized rubber obtained may be insufficient, while if it exceeds 50% by weight, the balance of the physical properties of the vulcanized rubber may be impaired. The more preferable content of the aromatic vinyl monomer unit is 10 to 40% by weight. Examples of the monomer forming the ethylenically unsaturated nitrile monomer unit include acrylonitrile and methacrylonitrile. Of these, acrylonitrile is preferable. These monomers may be used alone or in combination of two or more. Examples of the monomer forming the aromatic vinyl monomer unit include styrene and 2-
Methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-
Examples include butyl styrene and tert-butoxy styrene, and among these, styrene is particularly preferable.
These monomers may be used alone or in combination of two or more.

Further, examples of the monomer forming the conjugated diene monomer unit include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and chloroprene. Of which 1,3-
Butadiene and isoprene are particularly preferred. These monomers may be used alone or in combination of two or more. If necessary, the conjugated diene-based copolymer rubber may be obtained by copolymerizing various ester-based monomers in addition to the above-mentioned monomers.

Examples of the ester type monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-amyl (meth) acrylate and n-hexyl. (Meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth)
(Meth) acrylates such as acrylates, and vinyl esters such as vinyl acetate may be mentioned. The content of the monomer unit formed from these ester-based monomers can be a ratio in the range that does not impair the properties of the conjugated diene-based copolymer rubber, but with respect to the total amount of the monomer unit. It is preferably 20% by weight or less. Examples of the conjugated diene-based copolymer rubber of the present invention include acrylonitrile-butadiene-styrene copolymer and the like.

The glass transition point of the conjugated diene-based copolymer rubber varies depending on the composition ratio of the monomers used.
STM D3418-82 (Reapproved 1
988), when measured by a differential scanning calorimeter (DSC) according to 988), -70 to 0 ° C is preferable, and further -60 to
It is preferably −10 ° C. Further, the difference between the extrapolation start temperature and the extrapolation end temperature of the glass transition is preferably 20 ° C or lower, more preferably 18 ° C or lower, and further preferably 15 ° C.
C. or lower, particularly preferably 13.degree. C. or lower. The lower limit is usually 5 ° C. If this temperature difference exceeds 20 ° C., the wet skid performance of the obtained vulcanized rubber will deteriorate, and ta
nδ also becomes large, which is not preferable. Further, it is preferable that the content of the monomer unit (a) is 9 to 20% by weight, and the difference between the extrapolation start temperature and the extrapolation end temperature of the glass transition is 13 ° C. or less, particularly 10 ° C. or less. .

Here, the extrapolation start temperature and extrapolation end temperature of the glass transition are determined by ASTM D3418-82 (Reapp.
differential scanning calorimeter (DS)
According to C), it is measured as follows. That is,
The extrapolation start temperature is approximately the temperature between the straight line extending the low temperature side baseline and the inflection point P ₁ on the low temperature side and the inflection point P ₂ on the high temperature side in the temperature rising curve of the DSC shown in FIG. The extrapolation end temperature was determined as the temperature at the intersection of the straight line L and the extended straight line, and the extrapolation end temperature was obtained by extending the straight line L and the straight line extending the high temperature side baseline in the DSC heating curve shown in FIG. Obtained as the temperature at the point where the line intersects.

The Mooney viscosity [ML _{1 + 4} (100 ° C.)] of the conjugated diene-based copolymer rubber used in the present invention is 20 to 20.
0 is preferable, and 30 to 150 is more preferable. If the Mooney viscosity is less than 20, the vulcanized rubber obtained may have reduced wear resistance.
If it exceeds 0, the processability of the rubber composition containing the conjugated diene-based copolymer rubber may decrease. The weight average molecular weight of polystyrene of the conjugated diene copolymer rubber measured by GPC (gel permeation chromatography) is preferably 100,000 or more, particularly preferably 100,000 to 2,000.
It is 000. If this weight average molecular weight is less than 100,000, the abrasion resistance of the vulcanized rubber obtained tends to decrease, and tan δ may increase. on the other hand,
If it exceeds 2,000,000, the processability of the rubber composition containing the conjugated diene-based copolymer rubber may be lowered. This weight average molecular weight can be controlled during polymerization by using a chain transfer agent represented by alkyl mercaptan which is generally used in radical polymerization.

The conjugated diene-based copolymer rubber is produced by polymerizing the above-mentioned various essential monomers and, if necessary, an ester-based monomer in a water-based medium using a radical polymerization initiator. You can The polymerization method is not particularly limited, but emulsion polymerization is usually preferable. Emulsion polymerization may be a general method, for example, by emulsifying a predetermined monomer in an aqueous medium in the presence of an emulsifier, initiating polymerization with a radical polymerization initiator, and when a predetermined polymerization conversion rate is reached. A method of stopping the polymerization with a polymerization terminator can be mentioned.

In the present invention, the method of charging the above-mentioned ethylenically unsaturated nitrile monomer is important, and it is preferable to add it in divided portions to the polymerization system. It is preferable to add a part of the monomer before starting the polymerization and to add the rest intermittently or continuously to the polymerization system in the polymerization process.
Further, after the polymerization conversion rate of the total amount of the monomers charged measured during the polymerization is 10 to 95%, preferably 20 to 80%, the rest of the monomers are collectively or divided, Alternatively, it is preferable to add them continuously. When the whole amount of the monomer is charged into the polymerization system before the initiation of polymerization and copolymerized, the difference between the starting temperature and the ending temperature of the glass transition of the copolymer rubber tends to be larger than 20 ° C. Is not preferable. The initial charge amount of the monomer before the start of polymerization is preferably 20 with respect to the total amount of the monomer used.
˜95% by weight, more preferably 20 to 90% by weight, still more preferably 30 to 85% by weight.

As the emulsifier, an anionic surfactant,
Examples include nonionic surfactants, cationic surfactants and amphoteric surfactants. Further, a fluorinated surfactant can also be used. As these emulsifiers, anionic surfactants are frequently used, for example, capric acid, lauric acid, myristic acid, palmitic acid, oleic acid,
In addition to potassium salts or sodium salts of long-chain fatty acids having 10 or more carbon atoms such as stearic acid, rosin acid salts and the like can be used.

Radical polymerization initiators include benzoyl peroxide, lauroyl peroxide and tert.
-Butyl hydroperoxide, cumene hydroperoxide, paramenthane hydroperoxide, di-te
Organic peroxides such as rt-butyl hydroperoxide and dicumyl peroxide can be used. Further, an azo compound represented by azobisisobutyronitrile, an inorganic peroxide represented by potassium persulfate, and a redox catalyst represented by a combination of these peroxides and ferrous sulfate are used. You can also These radical polymerization initiators may be used alone or in combination of two or more.

In order to control the molecular weight of the conjugated diene copolymer rubber, a chain transfer agent such as alkyl mercaptans such as tert-dodecyl mercaptan and n-dodecyl mercaptan can be used as a chain transfer agent. Polymerization is carried out using a reactor from which oxygen is removed
It can be carried out at 0 ° C, and the polymerization temperature is particularly preferably 0 to 80 ° C. The polymerization system may be a continuous system or a batch system, and the polymerization temperature and the like or the operating conditions such as stirring and the like can be appropriately changed during the reaction. As the polymerization terminator, amine compounds such as hydroxylamine and diethylhydroxylamine can be used.
After the termination of the polymerization, the conjugated diene-based copolymer rubber latex was coagulated as a crumb from the produced conjugated diene-based copolymer rubber latex, the crumb was washed, dehydrated, and then dried with a dryer or the like to obtain a conjugated diene-based rubber. It can be a copolymer rubber.

Further, the conjugated diene-based copolymer rubber may contain an extending oil. In this case, the content of the extending oil is 100 parts by weight of the conjugated diene-based copolymer rubber. It is usually 10 to 60 parts by weight, preferably 20 to 50 parts by weight. If the amount of the extender oil is less than 10 parts by weight, the processability is not sufficiently improved, and if it exceeds 60 parts by weight, the amount ratio of the extender oil blended according to the required processability etc. at the time of preparing the rubber composition becomes large. It is not preferable because it is limited.
The Mooney viscosity [ML _{1 + 4} (100
[Deg.] C)] is preferably 20 to 180, particularly preferably 30.
~ 150. The extender oil is not particularly limited, and examples thereof include aromatic oils, naphthene oils, and paraffin oils. These may use only 1 type and may use 2 or more types together. Of these,
Aromatic extender oils are particularly preferred.

In the rubber composition of the present invention, it is necessary to contain 10% by weight or more of the conjugated diene copolymer rubber as the rubber component of the component (A). This content is 1
If it is less than 0% by weight, a rubber composition having desired physical properties cannot be obtained, and the object of the present invention cannot be achieved. The content of the conjugated diene-based copolymer rubber in the rubber component is preferably 35% by weight.
It is above, and especially 50 to 100% by weight is suitable. Examples of the rubber component used in combination with the conjugated diene-based copolymer rubber include natural rubber and diene-based synthetic rubber, and examples of the diene-based synthetic rubber include styrene-butadiene copolymer (SBR) and polybutadiene (BR). , Polyisoprene (IR), butadiene-isoprene copolymer, butadiene-styrene-isoprene copolymer, acrylonitrile-butadiene copolymer, chloroprene rubber, butyl rubber (IIR), ethylene-propylene copolymer and mixtures thereof. Can be mentioned. Further, a part thereof may have a branched structure by using a polyfunctional modifier, for example, a modifier such as tin tetrachloride.

Next, as the component (B), carbon black or a white filler may be used alone, or a combination system of carbon black / white filler may be used. Systems are preferred. Here, the carbon black is not particularly limited, and any carbon black can be selected and used from those conventionally used as a reinforcing filler for rubber. Examples of the carbon black include FEF, SRF, HAF, ISAF, S
AF etc. are mentioned. Iodine adsorption amount (IA)
Is 60 mg / g or more and the dibutyl phthalate oil absorption (DBP) is 80 ml / 100 g or more. By using this carbon black, the effect of improving various physical properties becomes great, but HAF, ISAF, and SAF, which are excellent in wear resistance, are particularly preferable.
Further, the white filler is not limited as long as it is conventionally used in the rubber industry, for example, as the white filler, silica, alumina, aluminum hydroxide,
Clay, calcium carbonate and the like are preferably used. Among them, especially the nitrogen adsorption specific surface area (N ₂ SA) is 190
~300m ² / g of silica, and a nitrogen adsorption specific surface area (N ₂ SA) of 1-20 m ² / g of aluminum hydroxide further Konomashiii. Specifically, aluminum hydroxide having such N ₂ SA is, for example, “Hydrite”.
There is a commercially available product as a trademark [Showa Denko KK]. The silica is not particularly limited and may be arbitrarily selected from those conventionally used as a reinforcing filler for rubber. Examples include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, and aluminum silicate. Among them, the effect of improving fracture properties and the effect of achieving both wet grip and low rolling resistance are the most effective. Wet silica, which is prominent, is preferred.

Here, the total amount of the carbon black as the component (B) and the white filler is preferably 40 to 120 parts by weight per 100 parts by weight of the rubber. Outside of this range, it is difficult to obtain a rubber composition having the desired physical properties, and the object of the present invention may not be achieved. The total amount of carbon black and the white filler is preferably 100 parts by weight or less from the viewpoint of the compounding effect and the physical properties. The white filler is preferably 10% by weight or more in the filler as the component (B). In the rubber composition used for the tire of the present invention, if desired, a silane coupling agent can be blended as the component (C). The silane coupling agent is not particularly limited, and known silane coupling agents conventionally used in rubber compositions such as bis (3-triethoxysilylpropyl) polysulfide, γ-mercaptopropyltriethoxysilane, γ-aminopropyl are used. Triethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-
Aminopropyltrimethoxysilane or the like can be used. The blending amount of the silane coupling agent used as desired is usually selected in the range of 1 to 20% by weight with respect to the filler. If this amount is less than 1% by weight, the effect as a coupling agent is not sufficiently exhibited, and if it exceeds 20% by weight, gelation of the rubber component may be caused. From the viewpoints of the effect as a coupling agent and the prevention of gelation, the preferable amount of the silane coupling agent is in the range of 5 to 15% by weight.

In the rubber composition, any process oil generally used in the rubber industry can be used as a softening agent. When a petroleum-based resin having a softening point of 30 to 150 ° C. is further added as a softening agent component, it is possible to satisfy all of the steering stability, wet grip performance, and wear resistance at a high level. it can. Preferable examples of such a resin include Escoletz (manufactured by Tonenx), Stractol TS30 (manufactured by Storactor) Quinton (manufactured by Nippon Zeon), neopolymer (manufactured by Nippon Oil Co., Ltd.), and coresin (manufactured by BASF). To be In the rubber composition, if desired, various chemicals other than the above, which are usually used in the rubber industry, such as a vulcanizing agent, a vulcanization accelerator, an antiaging agent, and a scorch preventive agent, are used as long as the object of the present invention is not impaired. Agents, zinc white, stearic acid, etc. may be contained. The pneumatic tire of the present invention can be produced by a conventional method by applying the rubber composition to a tread rubber. The pneumatic tire thus obtained has excellent performance particularly as a pneumatic tire for passenger cars having high exercise performance. In the present invention, air, nitrogen, or the like can be used as the gas filling the tire.

[0024]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Various measurements on the vulcanized rubber were made by the following methods. (1) Dynamic storage elastic modulus (E ') Using Toyo Seiki spectrometer, frequency 50H
The dynamic storage elastic modulus (E ′) at 30 ° C. was measured under the conditions of Z and strain of 1.0%. (2) Steering stability From the above-mentioned 30 ° C dynamic storage elastic modulus, a score when running at high speed was calculated and expressed as an index. The larger the value, the better. (3) Wet Grip Performance BPST (British Portable Skid Tester) was used to measure at room temperature. The larger the value, the better. (4) Abrasion resistance A Lambourn tester manufactured by Ueshima was used to measure the amount of abrasion at a slip ratio of 60% at room temperature. The larger the value, the better.

Production Example 1 (NSBR: oil-extended conjugated diene rubber) In a polymerization vessel, 200 parts by weight of water and 4.
5 parts by weight, 66 parts by weight of butadiene, 26 parts by weight of styrene, and 5 parts by weight of acrylonitrile were charged. Then, the temperature of the polymerization vessel was set to 5 ° C., and p-menthane hydroperoxide as a radical polymerization initiator was adjusted to 0.
03 parts by weight of ethylenediaminetetraacetic acid sodium salt was added.
02 parts by weight, 0.01 parts by weight of ferrous sulfate heptahydrate, and 0.02 parts of sodium formaldehyde sulfoxylate.
Polymerization was started by adding 3 parts by weight. Polymerization conversion rate is 30%
Then, 3 parts by weight of acrylonitrile was further added, and when the conversion of polymerization reached 60%, diethylhydroxylamine was added to terminate the polymerization. Then
Unreacted monomer is recovered by steam stripping,
A conjugated diene rubber latex was obtained. After that, 37. with respect to 100 parts by weight of the solid content contained in this latex.
An emulsion containing 5 parts by weight of aroma oil (manufactured by Fuji Kosan Co., Ltd., trade name "Fuccol Aromax # 3") was blended and coagulated with sulfuric acid and sodium chloride to give crumb. Next, this crumb was dried by a hot air dryer to obtain a conjugated diene rubber (NSBR) oil-extended with aroma oil. The conjugated diene rubber contained in the latex has a Mooney viscosity of 127, an acrylonitrile unit content of 10% by weight, a styrene unit content of 20% by weight, a weight average molecular weight of 640,000, and a glass transition point of -43 ° C. The difference between the extrapolation start temperature and the extrapolation end temperature of the glass transition was 11 ° C. The Mooney viscosity of the oil-extended conjugated diene rubber A (NSBR) was 49.

Examples 1 to 8 and Comparative Examples 1 to 6 As the rubber component, the conjugated diene rubber rubber (NSBR), styrene-butadiene copolymer rubber (SBR) and butadiene rubber (BR) obtained in the above Production Example 1 were used. Alternatively, a natural rubber was used to prepare a rubber composition according to the formulation shown in Table 1. This rubber composition was vulcanized at 160 ° C. for 15 minutes, and the physical properties of the vulcanized rubber were measured. The results are shown in Table 1.

[0027]

[Table 1]

[Note] 1) SBR0120: an oil-extended rubber of SBR, which is a trademark, manufactured by JSR, and has 35% by weight of bound styrene. (Rubber content 10
(37.5 parts by weight of oil is oil-extended with respect to 0 parts by weight) 2) NSBR according to Production Example 1: NSBR oil-extended rubber containing 10% by weight of acrylonitrile and 20% by weight of bound styrene.
(Oil extension of 37.5 parts by weight of oil to 100 parts by weight of rubber) 3) BR31: trademark, manufactured by JSR, cis-1,
4-Polybutadiene (Oil extension of 37.5 parts by weight of oil to 100 parts by weight of rubber) 4) Carbon black: SAF grade, manufactured by Tokai Carbon Co., Ltd. 5) Aluminum hydroxide: Hydilite 43M (trademark,
Showa Denko KK) 6) Silane coupling agent: "Si69" trademark Degussa, bis (3-triethoxysilylpropyl) tetrasulfide 7) petroleum resin: manufactured by C ₅ petroleum resins (Struktol Corporation) 8) Antiaging agent 6C: N- (1,3-dimethylbutyl)
-N'-phenyl-p-phenylenediamine 9) Vulcanization accelerator GPG: diphenylguanidine 10) Vulcanization accelerator CZ: N-cyclohexyl-2-benzothiazolylsulfenamide 11) Vulcanization accelerator DM: dibenzothia Jill disulfide

In the above, Example 1 is a carbon black compounding system as a filler, and Examples 2 to 6 and 8 are silica / carbon black combination systems. Furthermore, in Example 7, silica, carbon black, and aluminum hydroxide were used together as a filler. Comparing these results with Comparative Example 1, it is recognized that in the example according to the present invention, all of the steering stability, wet grip performance, and wear resistance are in good balance. That is, for example, when Examples 3 and 4 are compared with Comparative Example 4, 10% by weight or more of the SBR rubber of the conventional composition is the NSB in the present invention.
It can be seen that, by substituting with R, at least the wet grip performance and the steering stability are not adversely affected, and especially the wear resistance is significantly improved. Also, silica /
Example 7 of a combination system of Heidilite / carbon black
In comparison with Comparative Example 1, the wet grip performance is extremely excellent while maintaining the steering stability and wear resistance. Further, in the rubber composition of the present invention, as can be seen from Example 8 and Comparative Example 1, by blending a petroleum resin, steering stability, wet grip performance and wear resistance are made compatible at a higher level. You can see that you can. In the case of Examples 5 and 6 in which BR or natural rubber is blended with NSBR according to the present invention, the steering stability is slightly lowered, but both the wet grip performance and the abrasion resistance are remarkably improved. On the other hand, in Comparative Examples 1 to 6 using the conventional SBR containing a high styrene content, even if the compounding is changed, the result that the driving stability, the wet grip performance, and the wear resistance are not satisfied at a high level is not obtained. The stability is very poor.

[0030]

According to the present invention, as the tread rubber,
By using a conjugated diene-based copolymer rubber with a nitrile group that has improved affinity with reinforcing fillers such as silica and carbon black, steering stability, wet grip performance, and wear resistance are all at a high level. It is possible to obtain a satisfying pneumatic tire. Therefore, the pneumatic tire of the present invention can be effectively applied as a high performance pneumatic tire.

[Brief description of drawings]

FIG. 1 is a DSC chart showing how to determine an extrapolation start temperature and an extrapolation end temperature of a glass transition of a conjugated diene-based copolymer rubber according to the present invention.

Claims (8)

[Claims] 1. (A) (a) an ethylenically unsaturated nitrile monomer unit, (b) an aromatic vinyl monomer unit,
(C) a conjugated diene monomer unit, and based on the total amount of the above (a), (b) and (c) units,
A rubber component containing 10% by weight or more of a conjugated diene-based copolymer rubber containing (a) a unit of 5 to 45% by weight and (b) an aromatic vinyl monomer unit of 10 to 50% by weight, and (B) a carbon black. And a rubber composition containing at least one kind of filler selected from a white filler, and a rubber composition having a dynamic storage elastic modulus at 30 ° C. of 12.0 MPa or more of the rubber composition, a tread rubber. A pneumatic tire characterized by being used as. 2. The pneumatic tire according to claim 1, wherein the white filler is 10% by weight or more in the component (B). 3. The conjugated diene-based copolymer rubber has a glass transition temperature of −70 to 0 ° C. and a Mooney viscosity [ML _{1 + 4} (10
0 ° C.)] 20 to 200. The pneumatic tire according to claim 1 or 2. 4. The pneumatic tire according to claim 1, wherein the conjugated diene polymer rubber has a difference in extrapolation start temperature and extrapolation end temperature of glass transition of 20 ° C. or less. . 5. The pneumatic tire according to claim 1, wherein the conjugated diene-based copolymer rubber is a copolymer of acrylonitrile, styrene and butadiene. 6. The rubber component 100 is used as the filler of the component (B).
The pneumatic tire according to claim 1, which is 40 to 120 parts by weight per part by weight. 7. Further, for the filler of the component (B),
The pneumatic tire according to any one of claims 1 to 6, which comprises 1 to 20% by weight of (C) a silane coupling agent. 8. The white filler has a nitrogen adsorption specific surface area (N ₂
SA) is 190~300m ² / g of silica, and any one of claims 1 to 7 at least one thing nitrogen adsorption specific surface area (N ₂ SA) is selected from aluminum hydroxide of 1-20 m ² / g Pneumatic tire described in.