TW201825578A - Rubber composition and pneumatic tire - Google Patents

Abstract

A main object of the present disclosure is to provide a rubber composition excellent in workability and having an excellent balance of rolling resistance and wet grip performance. The present disclosure achieves the object by providing a rubber composition comprising in a range of 1 part by mass to 30 parts by mass of a hydrocarbon resin and in a range of 80 parts by mass to 200 parts by mass of silica, based on 100 parts by mass of a diene based rubber, wherein the hydrocarbon resin includes an aliphatic monomer unit and an aromatic monomer unit, a content of a monomer unit, having a structure that two or more cyclic structures among the aromatic monomer unit are bound, in the aromatic monomer unit is 50% by mass or more, a weight-average molecular weight Mw is in a range of 700 to 6000, and a softening point is in a range of 80 DEG C to 150 DEG C.

Description

Rubber composition and pneumatic tire

The present invention relates to a rubber composition which provides excellent balance between workability and rolling resistance and wet grip performance.

In recent years, due to environmental problems and resource problems, there is a strong demand for low fuel economy of automobile tires. On the other hand, in terms of safety, for example, it is required to improve wet grip performance. a crosslinked product of a rubber composition obtained by blending vermiculite as a filler in a rubber component as compared with a crosslinked product of a rubber composition obtained by blending carbon black (hereinafter, simply referred to as a rubber crosslinked product) In other words, the rolling resistance at the time of constituting the tire becomes small. Therefore, by using a crosslinked product of a rubber composition obtained by blending vermiculite to form a tire, a tire excellent in fuel economy can be obtained.

However, even if the vermiculite is blended in the conventional rubber component, the affinity between the rubber component and the vermiculite is insufficient, so that it is easy to separate, and the processability of the rubber composition before crosslinking is poor, and The rubber cross-linked product obtained by cross-linking has a problem such as insufficient rolling resistance when the tire is formed.

Further, in the patent document 1 (Japanese Patent Laid-Open Publication No. 2010-241965), it is disclosed that in order to improve the rolling resistance of the tire and the grip of the wet ground, the rubber component is simultaneously blended with a specific amount of softening of a specific structure. And a specific amount of a hydrocarbon resin of a specific structure.

In the case where the tire is produced by adding the rubber cross-linked product obtained by adding the softener and the hydrocarbon resin of the specific structure described in Patent Document 1, it is possible to improve the wet grip performance and the rolling resistance. But there are still insufficient issues.

The present invention has been made in view of the above problems, and a main object thereof is to provide a rubber composition which is excellent in workability and which has excellent balance between rolling resistance and wet grip performance.

The inventors of the present invention have focused on a hydrocarbon resin which imparts a superior balance between the rolling resistance and the wet grip performance, and has found that a hydrocarbon resin, which is improved in processing property and rolling with a rubber composition, has been found. The resistance and the wet grip performance are related to an upward improvement in the balance of the two properties, and the hydrocarbon resin comprises the monomer unit in a specified ratio and has a specified characteristic such as a weight average molecular weight within a specified range, wherein This monomer unit has a structure in which two or more ring structures are combined.

Thus, according to the present invention, it is possible to provide a rubber composition obtained by blending 1 to 30 parts by mass of a hydrocarbon resin and 80 to 2 parts by mass of vermiculite with respect to 100 parts by mass of the diene rubber. The rubber composition is characterized in that the hydrocarbon resin is composed of an aliphatic monomer unit and an aromatic monomer unit, and the aromatic monomer unit has a structure in which two or more cyclic structures are combined. The content of the monomer unit in the aromatic monomer unit is 50% by mass or more; the weight average molecular weight Mw of the hydrocarbon resin is in the range of 700 to 6000, and the softening point of the hydrocarbon resin is in the range of 80 to 150 °C. Inside.

The hydrocarbon resin is preferably an alicyclic monoolefin monomer unit having a 1,3-pentadiene monomer unit of 10% by mass to 60% by mass and a carbon number of 4 to 6 and a carbon number of 4% by mass to 30% by mass. ～8 of the acyclic monoolefin monomer unit is 1% by mass to 50% by mass, the alicyclic diolefin monomer unit is 0% by mass to 10% by mass, and the above aromatic monomer unit is 0.1% by mass to 50% by mass. % by mass, and the number average molecular weight (Mn) is in the range of 400 to 3000, the Z average molecular weight (Mz) is in the range of 1,500 to 20,000, and the ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) is 1.0. In the range of ～4.0, the ratio (Mz/Mw) of the Z average molecular weight to the weight average molecular weight is in the range of 1.0 to 4.0.

The monomer having a structure in which two or more cyclic structures are combined is preferably selected from the group consisting of a naphthalene compound, an anthracene compound, a biphenyl compound, an anthracene compound, a phenanthrene compound, an anthracene compound, and a benzothiophene compound. At least one of them.

The above hydrocarbon resin is preferably a value of a mixed aniline point measured by a minimum temperature at which a mixed solution of aniline, methylcyclohexane and the above hydrocarbon resin (volume ratio 2:1:1) exists in a state of a homogeneous solution. Within the range of 25 ° C to 100 ° C.

Further, according to the present invention, there can be provided a pneumatic tire characterized in that the above rubber composition is used for a tread.

The present invention exerts an effect of providing a rubber composition excellent in workability and excellent in balance between rolling resistance and wet grip performance.

The present invention relates to a rubber composition and a pneumatic tire for use in a tread. The rubber composition of the present invention and the pneumatic tire will be described in detail below.

I. Rubber composition

The rubber composition of the present invention is a rubber composition obtained by blending 1 to 30 parts by mass of a hydrocarbon resin and 80 to 2 parts by mass of vermiculite with respect to 100 parts by mass of the diene rubber. The hydrocarbon resin is characterized in that it contains an aliphatic monomer unit and an aromatic monomer unit, and a monomer unit having a structure in which two or more cyclic structures are combined among the above aromatic monomer units is in the above aromatic group. The content in the monomer unit is 50% by mass or more; the weight average molecular weight (Mw) is in the range of 700 to 6000, and the softening point is in the range of 80 to 150 °C.

According to the invention, the rubber composition contains vermiculite and a hydrocarbon resin having characteristics such as a specified weight average molecular weight and a softening point with respect to the specified amount of the diene rubber, whereby excellent workability, rolling resistance and wet grip can be obtained. A rubber composition having a superior balance in geodynamic performance, wherein the hydrocarbon resin comprises an aliphatic monomer unit and an aromatic monomer unit, and comprises at least two cyclic structures in a specified ratio in the above aromatic monomer unit. A monomer unit of the combined structure.

Here, the reason why the rubber composition is excellent in workability and the rubber composition having excellent balance between rolling resistance and wet grip performance can be obtained by using the above-described hydrocarbon resin is not clear, but it is estimated as follows. That is, a hydrocarbon resin containing a monomer unit having a structure in which two or more cyclic structures are combined in a predetermined ratio is used as an aromatic monomer unit, and has the above-mentioned specified characteristics. The hydrocarbon resin can be used such that the weight average molecular weight (Mw) is suitably low and the softening point is appropriately high. Therefore, the hydrocarbon resin is excellent in compatibility with the diene rubber, for example, it is easy to be uniformly mixed with the diene rubber, and the obtained rubber composition is excellent in workability, and the obtained rubber composition is obtained. The loss coefficient tan δ of the crosslinked product at 60 ° C can be lowered, and the loss coefficient tan δ at 0 ° C can be appropriately increased. As a result, for example, in the case of manufacturing a pneumatic tire in which such a rubber composition is used for a tread, it is possible to form a pneumatic tire or the like which has an excellent balance between rolling resistance and wet grip performance.

As described above, by including a predetermined amount of the above hydrocarbon resin with respect to the diene rubber, it is possible to obtain a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

Further, the rubber composition can obtain a rubber composition having excellent balance between rolling resistance and wet grip performance by further containing a specified amount of vermiculite. On the other hand, if the amount of the vermiculite blended is less than 80 parts by mass, the wet grip performance is deteriorated, and if it exceeds 200 parts by mass, the rolling resistance is deteriorated. On the other hand, in the case where the amount of the vermiculite blended is 80 parts by mass or more, the workability is deteriorated. Then, the rubber composition contains a predetermined amount of the hydrocarbon resin together with vermiculite, thereby suppressing a decrease in workability and improving the balance between rolling resistance and wet grip performance.

In this case, the rubber composition contains the hydrocarbon resin and vermiculite in a predetermined amount with respect to the diene rubber, and is excellent in workability, and has excellent balance between rolling resistance and wet grip performance.

The rubber composition of the present invention contains a diene rubber, a hydrocarbon resin, and a vermiculite. Hereinafter, each component contained in the rubber composition of the present invention will be described in detail.

A. Hydrocarbon resin

The above hydrocarbon resin is one containing an aliphatic monomer unit and an aromatic monomer unit.

1. Aromatic monomer unit

The aromatic monomer unit in the present invention is a monomer unit having a structure in which two or more cyclic structures are combined.

As a monomer constituting a monomer unit having a structure in which two or more cyclic structures are combined, it is generally preferred to use one or more aliphatic carbon-carbon unsaturated bonds in its molecular structure and two or more. The structure of the ring structure is combined. Here, as a structure in which two or more ring structures are combined, one or more aromatic rings may be included in two or more ring structures, and may include aromatic rings only. Ring and non-aromatic ring structures.

The aliphatic carbon-carbon unsaturated bond may be a vinyl group as long as it has a radical polymerizability.

The above aliphatic carbon-carbon unsaturated bond may be a vinyl group contained in a five-membered ring of an anthracene, and is included as a part of the above cyclic structure, and may also be a 1-vinylnaphthalene (1-vinylnaphthalene). The vinyl group contained is bonded to the ring structure. In the present invention, it is preferred that the above aliphatic carbon-carbon unsaturated bond is included as a part of the cyclic structure. This is because it is excellent in the controllability of polymerizability, molecular weight, and softening point. Further, in the case where the aliphatic carbon-carbon unsaturated bond is included as a part of the cyclic structure, the cyclic structure thereof is a non-aromatic ring structure.

In the case where the above aliphatic carbon-carbon unsaturated bond is included as a part of the cyclic structure, the carbon number of the cyclic structure including the above aliphatic carbon-carbon unsaturated bond as a part thereof can be formed as long as it has The hydrocarbon resin of the desired characteristics may be, for example, it may be set in the range of 4 to 8, but it is preferably in the range of 4 to 6. Further, in the case where the monomer having a structure in which two or more cyclic structures are combined is ruthenium, as described above, the aliphatic carbon-carbon unsaturated bond is included as a part of a five-membered ring of ruthenium, and The number of carbon atoms of the cyclic structure containing the above aliphatic carbon-carbon unsaturated bond as a part thereof is five.

In the case where the above aliphatic carbon-carbon unsaturated bond is bonded to the cyclic structure, the above aliphatic carbon-carbon unsaturated bond may be formed by a direct cyclic structure like a vinyl group contained in 1-vinylnaphthalene. The bond may be bonded to the cyclic structure through a spacer as well as an allyl group contained in allyl naphthalene.

Examples of the spacer include a hydrocarbon group bonded to a vinyl group such as a 2-propenyl group (allyl group) or a 1-butenyl group; and an acryl-based group, a methacryloyl group or the like is bonded to a vinyl group; Carbonyl group and the like.

The carbon number of the spacer may be a hydrocarbon resin having a desired property, and may be, for example, in the range of 1 to 3.

The number of the aliphatic carbon-carbon unsaturated bonds contained in the monomer having a structure in which two or more cyclic structures are combined is usually one or more, and for example, it may be set within a range of from 1 to 2, but It is better to be one. Further, in the case where two or more kinds of monomers are contained as the monomer having the structure in which two or more cyclic structures are combined, the number of the above aliphatic carbon-carbon unsaturated bonds means each monomer Contains the number of aliphatic carbon-carbon unsaturated bonds.

Further, examples of the structure in which two or more ring structures are combined include a naphthalene structure, a fluorene structure, a fluorene structure, a phenanthrene structure, a benzothiophene structure, a fluorene structure, and the like, and the cyclic structures form a condensed ring group with each other. a structure such as a biphenyl structure, a biphenyl structure, or the like, wherein the cyclic structures form a structure in which a single bond directly forms a base; or a structure comprising the following two structures: a structure in which a cyclic structure forms a condensed ring group with each other, And a structure in which the cyclic structures form a directly connected group with a single bond.

Further, the structure in which two or more cyclic structures are combined includes only an aromatic ring, and examples thereof include a naphthalene structure, a biphenyl structure, a fluorene structure, a phenanthrene structure, a benzothiophene structure, and the like; Examples of the non-aromatic ring structure include a fluorene structure and a fluorene structure.

In the present invention, it is preferred that the structure in which the above two or more cyclic structures are combined includes an aromatic ring and a non-aromatic ring structure. The reason for this is that the structure in which the two or more cyclic structures are combined includes an aromatic ring and a non-aromatic ring structure as a ring structure, and the hydrocarbon resin can impart excellent workability and rolling resistance. And the wet grip performance has achieved a superior balance of rubber composition.

The above-mentioned cyclic structure may have a carbon, such as a naphthalene structure, an anthracene structure, a biphenyl structure, an anthracene structure or a phenanthrene structure, and may have a ring structure, such as a benzothiophene structure, and the like. A heterocyclic ring of atoms other than the atom.

Further, the above cyclic structure may have a substituent. Examples of the substituent include the following: a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amine group, a nitro group, a sulfonic acid group, an amine methyl group, an amine sulfonium group. Base, ureido, alkyl, alkenyl, alkynyl, aliphatic fluorenyl, aliphatic decyloxy, alkoxy, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio (alkylthio group), alkylsulfonyl group, aliphatic guanamine group, aliphatic sulfonamide group, aliphatic substituted amine group, aliphatic substituted amine methyl group, aliphatic substituted amine sulfonyl group, fat The group replaces the urea group and the like.

The number of the above-described annular structures included in the structure in which the two or more annular structures are combined may be 2 or more, and may be set in the range of 2 to 6, but in the range of 2 to 3. It is better inside.

Further, specific examples of the monomer having a structure in which two cyclic structures are combined include 1-vinylnaphthalene, 4-vinylbiphenyl, anthracene, and the like. Further, specific examples of the monomer having a structure in which three cyclic structures are combined include 2,7-divinylfluorene and 9-vinylfluorene.

In the present invention, the monomer having a structure in which two or more cyclic structures are combined is a naphthalene compound, an anthracene compound, a biphenyl compound, an anthraquinone compound, a phenanthrene compound, an anthracene compound, and a benzothiophene compound. Good, among them, bismuth compounds are preferred, especially bismuth. The reason for this is that the hydrocarbon resin can provide excellent workability and superior balance between rolling resistance and wet grip performance by the single-system compound having a structure in which two or more annular structures are combined. Rubber composition.

Examples of the naphthalene compound include a naphthalene structure and one or more aliphatic carbon-carbon unsaturated bonds in the molecular structure thereof, and examples thereof include 1-vinylnaphthalene, 2-vinylnaphthalene, and allylic. Allyl naphthalene, butenyl naphthalene, and the like.

Examples of the ruthenium compound include a ruthenium structure and one or more aliphatic carbon-carbon unsaturated bonds in the molecular structure thereof, and examples thereof include 2,7-divinylfluorene and 2-vinylfluorene. , allyl fluorene, butenyl fluorene, and the like.

Examples of the biphenyl compound include a biphenyl structure and one or more aliphatic carbon-carbon unsaturated bonds in its molecular structure, and examples thereof include 4-vinylbiphenyl and 4-vinyl crosslinked. Triphenyl and so on.

Examples of the ruthenium compound include a ruthenium structure and one or more aliphatic carbon-carbon unsaturated bonds in the molecular structure thereof, and examples thereof include 9-vinyl fluorene, 2-vinyl fluorene, and 9, 10-divinyl anthracene, allyl fluorene, butenyl anthracene, and the like.

Examples of the phenanthrene compound include a phenanthrene structure and one or more aliphatic carbon-carbon unsaturated bonds in the molecular structure thereof, and examples thereof include 9-vinylphenanthrene and 3-vinylphenanthrene.

The ruthenium compound may be one having a ruthenium structure in its molecular structure, and examples thereof include ruthenium, formazan, acetamidine, acetamidine, butyl hydrazine, tertiary butyl fluorene, secondary butyl fluorene, and n-pentamidine. , 2-methyl-butylindene, 3-methyl-butylindene, n-hexyl, 2-methyl-pentylindene And an alkyl-substituted anthracene such as 3-methyl-pentylindene or 4-methyl-pentylindene.

Examples of the benzothiophene compound include a benzothiophene structure and one or more aliphatic carbon-carbon unsaturated bonds in its molecular structure, and examples thereof include 5-vinylbenzothiophene and 2- Vinyl dibenzothiophene and the like.

The monomer having a structure in which two or more cyclic structures are combined may be one containing only one type of monomer, or may be one containing two or more types of monomers. For example, the monomer having a structure in which two or more cyclic structures are combined may be a mixture of 9-vinyl anthracene and 9-vinylphenanthrene, etc., wherein 9-vinyl anthracene is an anthracene compound, 9- The vinylphenanthrene is a phenanthrene compound

The content of the monomer unit having a structure in which two or more cyclic structures are combined in the aromatic monomer unit may be 50% by mass or more, and may be in the range of 55% by mass to 99.9% by mass. Preferably, it is preferably in the range of 58% by mass to 99.85% by mass, particularly preferably in the range of 60% by mass to 99.8% by mass. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

The aromatic monomer unit may include a monomer unit having a structure in which two or more cyclic structures are combined, but may have a structure in which two or more cyclic structures are combined. The monomer unit further contains a monomer unit containing only one cyclic structure, that is, a monomer unit containing only one aromatic ring as a cyclic structure. Examples of the monomer constituting the monomer unit having only one cyclic structure include styrene, α-methylstyrene, and vinyltoluene.

The content of the aromatic monomer unit in the hydrocarbon resin may be a rubber composition which is excellent in workability and excellent in balance between rolling resistance and wet grip performance, and may be set to 0.1 mass, for example. In the range of from 5% by mass to 45% by mass, preferably from 5% by mass to 45% by mass, more preferably from 8% by mass to 43% by mass, particularly preferably from 10% by mass to 40% by mass. The range of % is better. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

2. Aliphatic monomer units

The aliphatic monomer unit in the present invention may be a hydrocarbon resin which exhibits the above specified characteristics and which can provide a rubber composition which is excellent in workability and which has excellent balance between rolling resistance and wet grip performance.

As such an aliphatic monomer unit, as long as it does not contain an aromatic ring, it is preferable to contain, for example, a 1,3-pentadiene monomer unit or an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms. An acyclic monoolefin monomer unit having 4 to 8 carbon atoms, an alicyclic diene monomer unit, or the like. For example, as the aliphatic monomer unit, the alicyclic monoolefin monomer unit 1 having a 1,3-pentadiene monomer unit of 10% by mass to 60% by mass and 4 to 6 carbon atoms in the hydrocarbon resin may be used. From 1% by mass to 30% by mass, from 4% by mass to 50% by mass of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms, and from 0% by mass to 10% by mass based on the alicyclic diene monomer unit.

The content of the 1,3-pentadiene monomer unit in the hydrocarbon resin is such that a hydrocarbon resin which can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance can be obtained. For example, it may be set in the range of 10% by mass to 60% by mass, preferably in the range of 15% by mass to 55% by mass, and preferably in the range of 20% by mass to 50% by mass, particularly in the range of 20% by mass to 50% by mass. It is preferably in the range of 25 mass% to 48 mass%. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

Further, the cis/trans isomer ratio in the 1,3-pentadiene may be any ratio and is not particularly limited.

The alicyclic monoolefin having 4 to 6 carbon atoms is a hydrocarbon compound having an aliphatic carbon-carbon unsaturated bond and a non-aromatic ring structure having 4 to 6 carbon atoms in a molecular structure. Specific examples of the alicyclic monoolefin having 4 to 6 carbon atoms include cyclobutene, cyclopentene, cyclohexene, methylcyclobutene, and methylcyclopentene.

The content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms in the hydrocarbon resin is a hydrocarbon composition which can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance. The resin may be, for example, set to be in the range of 1% by mass to 30% by mass, preferably in the range of 3% by mass to 28% by mass, and more preferably in the range of 5% by mass to 26% by mass. Preferably, it is preferably in the range of 7 mass% to 25% by mass. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

Further, in the alicyclic monoolefin having 4 to 6 carbon atoms, the ratio of each compound conforming thereto may be any ratio, and is not particularly limited, but it is preferably at least cyclopentene, and cyclopentene is used. The proportion of the alicyclic monoolefin having 4 to 6 carbon atoms is preferably 50% by mass or more.

The acyclic monoolefin having 4 to 8 carbon atoms is a chain hydrocarbon compound having one aliphatic carbon-carbon unsaturated bond in the molecular structure and having a ring structure and having 4 to 8 carbon atoms. Specific examples of the acyclic monoolefin having 4 to 8 carbon atoms include butenes such as 1-butene, 2-butene and isobutylene (2-methylpropene); 1-pentene and 2-pentyl a pentene such as alkene, 2-methyl-1-butene, 3-methyl-1-butene or 2-methyl-2-butene; 1-hexene, 2-hexene, 2-methyl Hexene such as 1-pentene; heptene such as 1-heptene, 2-heptene, 2-methyl-1-hexene; 1-octene, 2-octene, 2-methyl-1 An octene such as heptene or diisobutylene (2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene).

The content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the hydrocarbon resin is a hydrocarbon composition which can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance. The resin may be, for example, set to be in the range of 1% by mass to 50% by mass, preferably in the range of 5% by mass to 45% by mass, and more preferably in the range of 10% by mass to 42% by mass. Preferably, it is preferably in the range of 15% by mass to 40% by mass. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

Further, in the acyclic monoolefin having 4 to 8 carbon atoms, the ratio of each compound (including an isomer) conforming thereto may be any ratio, and is not particularly limited, but includes at least one selected from the group consisting of 2-methyl Preferably, at least one of the group consisting of 2-butene, isobutylene and diisobutylene is a total of 2-methyl-2-butene, isobutylene and diisobutylene in an acyclic monoolefin having 4 to 8 carbon atoms. The proportion of the amount is preferably 50% by mass or more.

The hydrocarbon resin may also contain an alicyclic diene in its raw material. The alicyclic diene has a hydrocarbon compound having two or more aliphatic carbon-carbon unsaturated bonds and a non-aromatic ring structure in its molecular structure. Specific examples of the alicyclic diene include a multimer of cyclopentadiene such as cyclopentadiene or dicyclopentadiene, methylcyclopentadiene, and methylcyclopentadiene. Polymer.

The content of the alicyclic diene monomer unit in the hydrocarbon resin may be, for example, a hydrocarbon resin which can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance, for example, It can be set in the range of 0% by mass to 10% by mass, preferably in the range of 0% by mass to 7% by mass, more preferably in the range of 0% by mass to 5% by mass, particularly preferably 0% by mass. It is preferably in the range of % by mass to 3% by mass. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

The aliphatic monomer unit is a 1,3-pentadiene monomer unit, an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, an acyclic monoolefin monomer unit having 4 to 8 carbon atoms, or a fat. In addition to the cyclic diene monomer unit, other monomer units may be contained in a range of a hydrocarbon resin which can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance. The other monomer used for constituting the other monomer unit is not particularly limited as long as it is an addition polymerizable compound which can be copolymerized with 1,3-pentadiene or the like other than the above monomer. limited. Among the above other monomers, for example, 1,3-butadiene, 1,2-butadiene, isoprene, 1,3-hexadiene, 1,4-pentadiene, etc. An unsaturated hydrocarbon having 4 to 6 carbon atoms other than pentadiene; an alicyclic monoolefin having 7 or more carbon atoms such as cycloheptene; an acyclic monoolefin having 4 to 8 carbon atoms such as ethylene, propylene or decene; .

However, the content of the above-mentioned other monomer unit in the hydrocarbon resin in the hydrocarbon resin may be any hydrocarbon resin having the above-mentioned specified characteristics, and specifically, it is usually in the range of 0% by mass to 30% by mass. It is preferably in the range of 0% by mass to 25% by mass, and more preferably in the range of 0% by mass to 20% by mass. The reason for this is that the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

The content of the above-mentioned aliphatic monomer unit in the hydrocarbon resin may be a rubber composition which is excellent in workability and has a superior balance between rolling resistance and wet grip performance, and may be set, for example, at 50. In the range of from 5% by mass to 99.9% by mass, it is preferably in the range of from 60% by mass to 90% by mass. This is because the above-mentioned content is in the above range, and the hydrocarbon resin can provide a rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance.

3. Hydrocarbon resin

The weight average molecular weight (Mw) of the hydrocarbon resin is not particularly limited as long as it is in the range of from 700 to 6,000, and preferably from 900 to 5,000, particularly preferably from 1,000 to 4,000. This is because the weight average molecular weight (Mw) is in the above range, and the hydrocarbon resin can be excellent in compatibility with the diene rubber. The reason for this is that the hydrocarbon resin is likely to lower the loss coefficient tan δ at 60 ° C in the crosslinked product of the rubber composition, and it is excellent in rolling resistance. Further, the reason is that the hydrocarbon resin is easy to increase the loss coefficient tan δ at 0 ° C by the weight average molecular weight (Mw) within the above range, so that excellent rolling resistance can be obtained.

The number average molecular weight (Mn) of the above hydrocarbon resin can be set in the range of from 400 to 3,000, more preferably from 450 to 2,500, particularly preferably from 500 to 2,000. This is because the number average molecular weight (Mn) is within the above range, and the hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, as for the crosslinked product of the rubber composition, since the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, excellent rolling resistance can be obtained.

The Z average molecular weight (Mz) of the above hydrocarbon resin can be set in the range of 1,500 to 20,000, preferably in the range of 1800 to 15,000, particularly preferably in the range of 2,000 to 10,000. This is because the Z average molecular weight (Mz) is in the above range, and the hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, as for the crosslinked product of the rubber composition, since the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, excellent rolling resistance can be obtained.

Further, in the present invention, the number average molecular weight (Mn), the weight average molecular weight (Mw), and the Z average molecular weight (Mz) of the hydrocarbon resin are obtained by using a polystyrene equivalent value measured by high performance liquid chromatography. . More specifically, the measurement of the number average molecular weight, the weight average molecular weight, and the Z average molecular weight can be performed by using "HLC-8320GPC" manufactured by Tosoh Corporation as a measuring device, and the column is connected with "TSKgel SuperMultiporeHZ" manufactured by Tosoh Corporation. The product was measured by using tetrahydrofuran as a solvent at a flow rate of 40 ° C and 1.0 mL/min.

The ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) of the above hydrocarbon resin may be set in the range of 1.0 to 4.0, preferably in the range of 1.1 to 3.5, particularly in the range of 1.2 to 3.0. It is better. The reason for this is that the hydrocarbon resin can be excellent in compatibility with the diene rubber by the above ratio within the above range. In addition, as a result of the crosslinked product of the rubber composition, the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, and it is excellent in wet grip performance.

The ratio (Mz/Mw) of the Z average molecular weight to the weight average molecular weight of the above hydrocarbon resin may be set in the range of 1.0 to 4.0, preferably in the range of 1.1 to 3.5, particularly in the range of 1.2 to 3.0. It is better. The reason for this is that the hydrocarbon resin can be excellent in compatibility with the diene rubber by the above ratio within the above range. As a result, as for the crosslinked product of the rubber composition, since the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, excellent wet grip performance can be obtained.

The softening point of the hydrocarbon resin is not particularly limited as long as it is in the range of 80 ° C to 150 ° C, and preferably in the range of 85 ° C to 145 ° C, particularly preferably in the range of 90 ° C to 140 ° C. The reason for this is that the hydrocarbon resin can be excellent in compatibility with the diene rubber by having the softening point within the above range. In addition, as a result of the crosslinked product of the rubber composition, the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, and it is excellent in rolling resistance. Further, the reason is that the softening point is in the above range, and the hydrocarbon resin is easy to increase the loss coefficient tan δ at 0 ° C, so that excellent wet grip performance can be obtained.

Further, the softening point in the present invention is a value measured for a hydrocarbon resin, for example, in accordance with JIS K 6863.

The mixed aniline point (MMAP) of the above hydrocarbon resin can be set in the range of 25 ° C to 100 ° C, preferably in the range of 27 ° C to 90 ° C, particularly preferably in the range of 30 ° C to 75 ° C. This is because the mixed aniline is in the above range, and the hydrocarbon resin can be excellent in compatibility with the diene rubber. In addition, as a result of the crosslinked product of the rubber composition, the hydrocarbon resin is liable to lower the loss coefficient tan δ at 60 ° C, and it is excellent in rolling resistance. Further, the reason is that, by mixing the aniline point within the above range, since the hydrocarbon resin system easily increases the loss coefficient tan δ at 0 ° C, excellent wet grip performance can be obtained.

Further, the mixed aniline point in the present invention is a temperature measured by a minimum temperature at which a mixed solution of aniline, methylcyclohexane and the above hydrocarbon resin (volume ratio 2:1:1) exists in a state of a uniform solution, For example, for a hydrocarbon resin, the value measured by using methylcyclohexane instead of heptane is used in accordance with JIS K 2256.

The blending amount of the hydrocarbon resin is not particularly limited as long as it is 1 part by mass to 30 parts by mass based on 100 parts by mass of the diene rubber, but it is 5 parts by mass to 20 parts by mass based on 100 parts by mass of the diene rubber. The range is better. The reason for this is that the rubber composition is excellent in workability and has a superior balance between rolling resistance and wet grip performance by the above-mentioned blending amount within the above range.

Further, the blending amount of the hydrocarbon resin is preferably in the range of 1% by mass to 30% by mass based on the blending amount of the vermiculite, and preferably in the range of 3% by mass to 25% by mass.

4. Method for producing hydrocarbon resin

The method for producing the hydrocarbon resin may be a method of obtaining a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit, and a method of forming the above aliphatic monomer unit and aromatic compound may be mentioned. A method of appropriately performing addition polymerization of a polymerizable component (monomer mixture A) of a monomer of a monomer unit.

For example, a hydrocarbon resin can be obtained by addition polymerization using a cationic polymerization catalyst of the Friedel-Crafts type. As a method for preferably producing a hydrocarbon resin, a method having a polymerization step as described below: a combination of an aluminum halide (A) and a halogenated hydrocarbon (B) as a polymerization catalyst, and comprising the above The monomer mixture A of the aliphatic monomer and the aromatic monomer is polymerized, wherein the halogenated hydrocarbon (B) is selected from a halogenated hydrocarbon (B1) comprising a tertiary carbon atom bonded to a halogen atom, and adjacent to the carbon a group of halogenated hydrocarbons (B2) in which a carbon atom of a carbon unsaturated bond is bonded to a halogen atom.

Further, the amount of each monomer contained in the monomer mixture A may be set to be the same as the content of each monomer unit in the hydrocarbon resin.

Therefore, the alicyclic monoolefin monomer unit containing 10% by mass to 60% by mass of the 1,3-pentadiene monomer unit and 4 to 6 carbon atoms is produced in an amount of 1% by mass to 30% by mass, and the carbon number is 4-8. 1% by mass to 50% by mass of the acyclic monoolefin monomer unit and 0% by mass to 10% by mass of the alicyclic diene monomer unit as an aliphatic monomer unit, and containing 0.1% by mass to 50% by mass of aromatic In the case of a hydrocarbon resin of a monomer unit, the above production method, more specifically, may be set to have a polymerization step of containing 10% by mass to 60% by mass, and carbon number of the 1,3-pentadiene monomer. 4 to 6 alicyclic monoolefin monomers 1% by mass to 30% by mass, 4 to 8 carbon atoms of acyclic monoolefin monomer, 1% by mass to 50% by mass, and alicyclic diene monomer 0% by mass ～10% by mass, and a monomer having a structure in which two or more cyclic structures are combined, a content of 50% by mass or more of the aromatic monomer in the aromatic monomer of 0.1% by mass to 50% by mass The bulk mixture A was polymerized.

Specific examples of the aluminum halide (A) include aluminum chloride (AlCl ₃ ), aluminum bromide (AlBr ₃ ), and the like. Among them, aluminum chloride is preferably used from the viewpoint of versatility and the like.

The amount of use of the aluminum halide (A) is not particularly limited, but is preferably in the range of 0.05 parts by mass to 10 parts by mass, based on 100 parts by mass of the polymerizable component (monomer mixture A), and is 0.1 parts by mass. A range of 5 parts by mass is preferred.

By using the halogenated hydrocarbon (B) in combination with the aluminum halide (A), the activity of the polymerization catalyst can be extremely excellent.

Specific examples of the halogenated hydrocarbon (B1) in which a tertiary carbon atom and a halogen atom are bonded to each other include tertiary t-butyl chloride and tertiary t-butyl bromide. 2-chloro-2-methylbutane, triphenylchloromethane. Among these, in view of obtaining a superior balance between activity and ease of handling, it is preferable to use tertiary chlorobutane.

The unsaturated bond in the halogenated hydrocarbon (B2) in which a carbon atom adjacent to a carbon-carbon unsaturated bond is bonded to a halogen atom includes a carbon-carbon double bond and a carbon-carbon triple bond, and is also included. A carbon-carbon conjugated double bond in an aromatic ring or the like. Specific examples of such a compound include α-chlorobenzyl, α-brominated bromide, (1-chloroethyl)benzene, and allyl chloride. 3-Chloro-1-propyne, 3-chloro-1-butene, 3-chloro-1-butyne, cinnamic chloride. Among these, α-chlorotoluene is preferably used from the viewpoint of achieving a superior balance between activity and ease of handling. Further, the halogenated hydrocarbons (B) may be used alone or in combination of two or more.

The amount of the halogenated hydrocarbon (B) to be used is preferably in the range of 0.05 to 50, and preferably in the range of 0.1 to 10, based on the molar ratio of the aluminum halide (A).

In the polymerization reaction, the order of adding the components of the monomer mixture and the polymerization catalyst to the polymerization reactor is not particularly limited, and may be added in an arbitrary order, but the polymerization reaction is preferably controlled from the above. From the viewpoint of precisely controlling the weight average molecular weight and the like, it is preferred to partially add a monomer mixture and a component of the polymerization catalyst to the polymerization reactor, and after starting the polymerization reaction, the residual portion of the polymerization catalyst is added to the polymerization. reactor.

In the case of producing a hydrocarbon resin, in the case where an alicyclic monoolefin monomer unit is contained as an aliphatic monomer unit, it is preferred to first mix the aluminum halide (A) with the alicyclic monoolefin. The reason for this is that by contacting the aluminum halide (A) with an alicyclic monoolefin, gel formation can be prevented, and a hydrocarbon resin having a weight average molecular weight or the like controlled with a preferable precision can be obtained.

The amount of the alicyclic monoolefin to be mixed with the aluminum halide (A) is preferably at least 5 times (mass ratio) of the amount of the aluminum halide (A). If the amount of the alicyclic monoolefin is too small, the effect of preventing gel formation is insufficient. The mass ratio of the alicyclic monoolefin to the aluminum halide (A) is preferably 5:1 to 120:1, preferably 10:1 to 100:1, and more preferably 15:1 to 80:1. . If more alicyclic monoolefins are used in this ratio, the catalytic activity is lowered and the polymerization cannot be sufficiently carried out.

In the case of mixing the aluminum halide (A) with the alicyclic monoolefin, the order of the input is not particularly limited, and the aluminum halide (A) may be introduced into the alicyclic monoolefin, and vice versa, in the aluminum halide (A). The alicyclic monoolefin is charged. Mixing is usually accompanied by heat generation, so a suitable diluent can also be used. As a diluent, the solvent mentioned later can be used.

In the case where the aliphatic monomer unit further contains a 1,3-pentadiene monomer unit or an acyclic monoolefin monomer unit in addition to the alicyclic monoolefin monomer unit, it is preferably as described above. After the mixture M of the aluminum halide (A) and the alicyclic monoolefin is prepared, a mixture a comprising at least 1,3-pentadiene and an acyclic monoolefin is mixed with the mixture M. The aforementioned mixture a may also contain an alicyclic diene.

The preparation method of the mixture a is not particularly limited, and the target mixture a may be obtained by mixing a pure compound, and the target mixture a may be obtained by using, for example, a mixture of a target monomer containing a fraction derived from petroleum brain lysate or the like. For example, in order to incorporate 1,3-pentadiene or the like into the mixture a, it is preferred to use a C5 fraction obtained by extracting isoprene and cyclopentadiene (including a polymer thereof).

It is preferred to further mix the halogenated hydrocarbon (B) with the mixture a and the mixture M. The order of input of these three is not particularly limited.

From the viewpoint of more preferably controlling the polymerization reaction, it is preferred to add a solvent to the polymerization reaction system and carry out the polymerization reaction. The type of the solvent is not particularly limited as long as it does not interfere with the polymerization reaction, but is preferably a saturated aliphatic hydrocarbon or an aromatic hydrocarbon. Examples of the saturated aliphatic hydrocarbon to be used as a solvent include n-pentane, n-hexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, and 3 -methylhexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethyl a chain-like saturated aliphatic hydrocarbon having 5 to 10 carbon atoms such as pentane, 2,2,3-trimethylbutane or 2,2,4-trimethylpentane; cyclopentane, cyclohexane, cycloglycan A cyclic saturated aliphatic hydrocarbon having a carbon number of 5 to 10, such as an alkane or a cyclooctane. Examples of the aromatic hydrocarbon to be used as the solvent include aromatic hydrocarbons having a carbon number of 6 to 10 such as benzene, toluene or xylene. The solvent may be used singly or in combination of two or more. The amount of the solvent to be used is not particularly limited, but is preferably in the range of 10 parts by mass to 1,000 parts by mass, and preferably 50 parts by mass to 500 parts by mass, per 100 parts by mass of the polymerizable component (monomer mixture A). The range is preferred. Further, for example, a mixture of an addition polymerizable component and a non-addition polymerizable component such as a mixture of cyclopentane and cyclopentene derived from a C5 fraction may be added to the polymerization reaction system, and the addition polymerizable component may be added. As the component which is a monomer mixture, a non-addition polymerizable component is used as a solvent.

The polymerization temperature at the time of carrying out the polymerization reaction is not particularly limited, but is preferably in the range of from -20 ° C to 100 ° C, and more preferably in the range of from 0 ° C to 75 ° C. When the polymerization temperature is too low, the polymerization activity may be lowered and the productivity may be poor. When the polymerization temperature is too high, the controllability of the weight average molecular weight of the obtained hydrocarbon resin may be poor. The pressure at which the polymerization is carried out may be at atmospheric pressure or under pressure. The polymerization reaction time can be appropriately selected, but it is usually selected in the range of 10 minutes to 12 hours, and it is preferably selected in the range of 30 minutes to 6 hours.

The polymerization reaction can be stopped by adding a polymerization terminator such as methanol, an aqueous sodium hydroxide solution, or an aqueous ammonia solution to the polymerization reaction system at the time point when the desired polymerization conversion ratio is obtained.

The method for producing the hydrocarbon resin described above is at least the above-mentioned polymerization step, but may have other steps as needed. As the other step, for example, after the polymerization step, by removing the polymerization terminator in the polymerization step, the solvent-insoluble catalyst residue formed when the polymerization catalyst is inactivated may be removed by filtration or the like. Catalyst residue removal step; after the polymerization reaction caused by the polymerization step is stopped, the unreacted monomer and solvent are removed, and the low molecular weight oligomer component is removed by steam distillation or the like, and cooled, thereby obtaining a solid Recovery step of resin, etc.

B. Diene rubber

As the diene rubber, any diene rubber which can be blended with a hydrocarbon resin and vermiculite to a rubber composition can be used. As such a diene rubber, for example, a diene rubber described in JP-A-2015-189873 can be used. More specifically, the diene rubber may, for example, be natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), or styrene-butadiene copolymer rubber (SBR). Acrylonitrile-butadiene copolymer rubber (NBR), ethylene-propylene-diene terpolymer rubber (EPDM), etc., of which styrene-butadiene copolymer rubber, natural rubber, etc. are preferred. The reason for this is that a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance can be obtained by the above diene rubber. The diene rubber may be contained in at least one type, or may be used alone or in combination of two or more.

Further, the diene rubber is not particularly limited in molecular weight and microstructure, and may be terminally modified by an amine, a guanamine, a mercapto group, an alkoxysilyl group, a carboxyl group or a hydroxyl group, or may be subjected to a ring. Oxidation. The diene rubber may be a hydrogen addition product, but it is preferred that the hydrogen addition is not performed.

C. Meteorite

The vermiculite is blended with the diene rubber and the above hydrocarbon resin into the rubber composition.

As such a vermiculite, a rubber composition excellent in workability and excellent balance between rolling resistance and wet grip performance can be imparted by blending with a diene rubber and the above hydrocarbon resin into a rubber composition. For example, the same as the vermiculite described in Japanese Patent Laid-Open Publication No. 2016-3274 can be used. More specifically, the above-mentioned vermiculite, dry vermiculite, wet vermiculite, citric acid gel and precipitated vermiculite can be used. Further, the type of the vermiculite may be two or more kinds alone or in combination.

Silica aforementioned BET specific surface area (in accordance with ISO5794 / 1 for measurement) may be set in a range of ^{100m 2 / g ~ 400m 2 /} g , of which in the range of ^{150m 2 / g ~ 350m 2 /} g are preferred.

The amount of the above-mentioned vermiculite is not particularly limited as long as it is 80 parts by mass to 200 parts by mass based on 100 parts by mass of the diene rubber, but it is 90 parts by mass to 150 parts by mass based on 100 parts by mass of the diene rubber. The scope of the serving is preferred. The reason for this is that the rubber composition is excellent in workability and has a superior balance between rolling resistance and wet grip performance by the above-mentioned blending amount.

D. Other ingredients

The rubber composition of the present invention contains a diene rubber, a hydrocarbon resin, and a vermiculite, but may contain other components as necessary. As the above other components, a necessary amount of a blending agent may be blended, for example, a decane coupling agent, a crosslinking agent, a crosslinking accelerator, a crosslinking activation agent, an anti-aging agent, an active agent, and a processing oil. (process oil), plasticizer, lubricant, adhesive, etc. In addition, the content of such other components and the content thereof can be set, for example, in the same manner as described in Japanese Patent Laid-Open Publication No. 2016-30795.

The above other components may include fillers other than vermiculite. As the filler other than the vermiculite, a general user of the rubber composition can be used, and examples thereof include carbon black, clay, diatomaceous earth, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, and aluminum hydroxide. In addition to various metal powders, wood powders, glass powders, ceramic powders, etc., inorganic hollow fillers such as glass balloons and silica balloons; polystyrene and polydifluoroethylene are also included; An organic hollow filler such as ethylene or a polydifluoroethylene copolymer. Among these fillers, for example, carbon black or the like can be used as described in Japanese Patent Laid-Open Publication No. 2016-30795.

In the present invention, the filler is preferably carbon black or the like. The reason for this is that the rubber composition is excellent in wet grip property by being the above filler.

In addition, the filler may be contained in at least one type, and may be used in combination of two or more types.

The content of the filler other than the vermiculite may be any rubber composition which is excellent in workability and has excellent balance between rolling resistance and wet grip performance. The content is, for example, 120 parts by mass or less based on 100 parts by mass of the diene rubber.

E. Rubber composition

In the method for producing the rubber composition of the present invention, the components may be kneaded by a usual method, and for example, a component obtained by removing a component which is unstable to heat such as a crosslinking agent or a crosslinking accelerator may be removed from the diene rubber. After the kneading, a component which is unstable to heat, such as a crosslinking agent or a crosslinking accelerator, is mixed in the kneaded product to obtain a target composition. The kneading temperature of the component obtained by removing the component which is unstable to heat and the diene rubber is preferably in the range of 80 ° C to 200 ° C, and preferably in the range of 120 ° C to 180 ° C. The kneading time is preferably from 30 seconds to 30 minutes. Further, the mixing of the kneaded material and the component which is unstable to heat is usually carried out after cooling to 100 ° C or lower, and it is preferably carried out after cooling to 80 ° C or lower.

As a crosslinking method of the rubber composition of the present invention as a rubber crosslinked product, a known crosslinking method can be used, and for example, a molding machine corresponding to a desired shape, for example, an extruder, A method in which a molding machine, a compressor, a roll, and the like are injection molded, and a crosslinking reaction is performed by heating to fix a shape to form a crosslinked product. In this case, molding and crosslinking can be simultaneously performed even if crosslinking is carried out after molding is performed in advance. The molding temperature is usually in the range of 10 ° C to 200 ° C, and preferably in the range of 25 ° C to 120 ° C. The crosslinking temperature is usually in the range of 100 ° C to 200 ° C, preferably in the range of 130 ° C to 190 ° C, and the crosslinking time is usually in the range of 1 minute to 24 hours, in the range of 2 minutes to 12 hours. The range is preferably in the range of from 3 minutes to 6 hours.

Further, depending on the shape and size of the rubber crosslinked product, even if the surface is crosslinked, the inside is not sufficiently crosslinked. Therefore, the crosslinking method may be further heated to perform secondary crosslinking.

As the heating method, a general method used for crosslinking the rubber composition such as press heating, steam heating, oven heating, or hot air heating may be appropriately selected.

The rubber composition of the present invention achieves a superior balance between rolling resistance and wet grip performance. Moreover, the rubber composition of the present invention utilizes such characteristics for use in, for example, a tread of a tire (tread running surface, tread base), carcass, sidewall, bead (bead) It is preferable to use various parts of the tires, such as all-season tires, high-performance tires, and studless tires, which are preferably used in treads, carcasses, and tires. Various parts of the tire such as the side and the lip portion are particularly excellent for low heat build-up, and therefore are particularly suitable for use as a tread for a low-burning tire, and particularly preferably used for a tread running surface.

II. Pneumatic tires

Next, the pneumatic tire of the present invention will be described. The pneumatic tire of the present invention is characterized in that the above rubber composition is used for a tread.

The tread is formed by using the rubber composition described above, that is, the rubber composition is used, and usually the crosslinked product of the rubber composition is contained.

The rubber composition used to form such a tread and the crosslinked product thereof can be set to be the same as those described in the above-mentioned "I. Rubber composition", and thus the description thereof will be omitted.

The pneumatic tire may be formed by using the rubber composition as the tread, or may be formed by using the rubber composition in other portions.

The tread formed by using the above rubber composition may be a part of the tread or the whole of the tread, but it is preferable to include at least a tread running surface.

Further, the method for producing a pneumatic tire according to the present invention may be any method as long as it can produce a pneumatic tire having a tread formed using the above composition, and a known method for producing a pneumatic tire can be used.

The present invention is not limited to the above embodiment. The above-described embodiments are exemplified, and those having substantially the same configuration as the technical idea described in the patent application scope of the present invention and having the same effects are included in the technical scope of the present invention.

The embodiment will be described below.

The examples and comparative examples are listed below, and the present invention will be specifically described. Further, the parts and % in each example are based on mass unless otherwise specified.

Various measurements were made in accordance with the following methods.

[Quantum average molecular weight, weight average molecular weight, Z average molecular weight, and molecular weight distribution]

For the hydrocarbon resin as a sample, gel permeation chromatography analysis was performed to obtain a number average molecular weight (Mn), a weight average molecular weight (Mw), and a Z average molecular weight (Mz) in terms of standard polystyrene, and the molecular weight distribution system was obtained. It is expressed by the ratio of Mw/Mn and the ratio of Mz/Mw. In addition, in the gel permeation chromatography, "HLC-8320GPC" manufactured by Tosoh Corporation was used as a measuring device, and the column was connected with three "TSKgel SuperMultiporeHZ" manufactured by Tosoh Co., Ltd., and tetrahydrofuran was used as a solvent at 40 ° C. The flow rate of 1.0 mL/min was measured.

[softening point (°C)]

The hydrocarbon resin as a sample was measured in accordance with JIS K 6863.

[mixed aniline point (°C)]

The hydrocarbon resin as a sample was measured in accordance with JIS K 2256 using methylcyclohexane instead of heptane.

[Moneyy viscosity (ML1+4)]

The rubber composition as a sample was measured by the following conditions in accordance with JIS K 6300-1:2001. This characteristic is expressed by an index in which a reference sample (Comparative Example 1 described later) is set to 100.・Test temperature: 100°C ・Type of rotor: L shape ・Use test machine: Shimadzu viscometer SMV-300J manufactured by Shimadzu Corporation

[tensile strength (MPa) and elongation (%)]

For the test piece of the rubber cross-linked product as a sample, tensile strength (MPa) and elongation (%) were measured in accordance with JIS K 6251:2010 under the following conditions. These characteristics are expressed by an index that sets a reference sample (Comparative Example 1 described later) to 100.・Test piece production method: After the sheet is formed by pressurization and vulcanization, punching processing is performed. The shape of the test piece: Dumbbell shape No. 3 and test piece take direction: Parallel direction with respect to texture (test) Number of sheets: 3 ・Measurement temperature: 23 °C ・Test speed: 500 mm/min ・Use test machine: TENSOMETER 10k manufactured by ALPHA TECHNOLOGIES Co., Ltd. ・Tester capacity: load cell type 1kN

[loss tangent tan δ]

The test piece for the rubber cross-linked product as a sample was subjected to the following measurement conditions in accordance with JIS K 7244-4, and the loss tangent tan δ at 0 ° C and 60 ° C was measured using dynamic strains of 0.5% and 10 Hz. . This characteristic is expressed by an index which sets a reference sample (comparative example 1 mentioned later) to 100. In addition, the higher the tangent tan δ at 0 °C, the better the wet grip performance, and the lower the tangent tan δ at 60 ° C, the better the rolling resistance. Measurement item: dynamic storage elastic modulus E': dynamic loss elastic modulus E'': loss tangent tan δ ・sample preparation method: sheet punching and test piece Shape: length 50 mm × width 2 mm × thickness 2 mm ・Number of test pieces: 1 ・Clamp spacing: 20 mm

[Manufacturing Example 1]

In the polymerization reactor, a mixture of 56.1 parts of cyclopentane and 15.5 parts of cyclopentene was charged into a polymerization reactor, and after raising the temperature to 70 ° C, 0.75 parts of aluminum chloride (mixture M ₁ ) was added. Next, it will contain 46.7 parts of 1,3-pentadiene, 18.4 parts of isobutylene, 0.1 part of diisobutylene, 0.1 part of dicyclopentadiene, 0.2 part of C4-C6 unsaturated hydrocarbon, 7.2 part of C4-C6 saturated hydrocarbon, and aromatic A mixture a _{1 of} 19.0 parts of a monoolefin was maintained at a temperature (70 ° C) for 60 minutes, and continuously added to a polymerization reactor containing the aforementioned mixture M ₁ while carrying out polymerization. Thereafter, an aqueous sodium hydroxide solution was added to the polymerization reactor to terminate the polymerization reaction. Further, the kinds and amounts of the components in the polymerization reactor at the time of the polymerization were shown in Table 1. After the precipitate formed by the polymerization stop was removed by filtration, the obtained polymer solution was charged into a distillation pot, and heated under a nitrogen atmosphere to remove the polymerization solvent and the unreacted monomer. Next, the hydrocarbon resin of Production Example 1 was obtained by blowing saturated steam at 240 ° C or higher while distilling off the low molecular weight oligomer component. The number average molecular weight, the weight average molecular weight, the Z average molecular weight, the molecular weight distribution, the softening point, and the mixed aniline point of the obtained hydrocarbon resin of Production Example 1 were measured. These measurements are consolidated and are shown in Table 1 below.

Further, the aromatic monoolefin contained in the mixture a ₁ is contained as an aromatic monomer. Further, as the aromatic monoolefin, 0.95 parts of styrene (5.0% by mass of the aromatic monomer) and 18.05 parts of 1-vinylnaphthalene (95.0% by mass of the aromatic monomer) were used.

[Production Examples 2 to 6]

A hydrocarbon resin was obtained in the same manner as in Production Example 1 except that the types and amounts of the components added to the polymerization reactor were changed as shown in Table 1 below. The number average molecular weight, the weight average molecular weight, the Z average molecular weight, the molecular weight distribution, the softening point, and the mixed aniline point of the hydrocarbon resin of Production Examples 2 to 6 obtained in the same manner as in the hydrocarbon resin of Production Example 1 were measured. These measurements are consolidated and are shown in Table 1 below.

In addition, in the production examples 2 to 6, as the aromatic monomer other than the monomer having a structure in which two or more cyclic structures are combined, styrene is used in the same manner as in Production Example 1. Further, in Production Example 4, those which do not contain an aromatic monomer are included.

[Table 1]

[Example 1]

In the Banbury mixer, oil-extended emulsion polymerized styrene butadiene rubber (E-SBR) (trade name "Nipol 1739", manufactured by Nippon Seon Co., Ltd., combined with benzene Amount of ethylene: 40%, vinyl bond content of butadiene unit portion: 13.5 mol%, weight average molecular weight: 690,000, molecular weight distribution (Mw/Mn): 3.98, glass transition temperature (Tg): −35 ° C, 96.3 parts of an extender oil containing 37.5 parts with respect to 100 parts of the rubber component (content of rubber component: 70 parts, content of filler oil: 26.3 parts), solution-polymerized styrene butadiene rubber (S-SBR) (trade name "Nipol NS 616", manufactured by Nippon Seychelles Co., Ltd., Muni viscosity (ML1+4, 100 °C): 62) 15.0 parts, and natural rubber (NR) (SIR20) 15.0 parts, kneaded for 30 seconds In the following, 60.0 parts of a vermiculite (trade name "Zeosil 1165MP", manufactured by Rhodia Co., Ltd.), 20.0 parts of carbon black (manufactured by Cabot Japan Co., Ltd., trade name "N234"), and a decane coupling agent: tetrasulfide double [ 3-(triethoxysilyl)propane](bis[3-(triethoxysilyl)propy 9.0 parts of tetrasulfide) (trade name "Si69" manufactured by Degussa Co., Ltd.) and 10.0 parts of a hydrocarbon resin obtained in Production Example 1. After kneading for 90 seconds, a vermiculite (trade name "Zeosil 1165MP" manufactured by Rhodia Co., Ltd.) was added. 40.0 parts, 3.0 parts of zinc oxide, 2.0 parts of stearic acid, and an anti-aging agent: N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (manufactured by Ouchi Shinko Co., Ltd., In the case of the product name "NOCRAC6C", 2.0 parts were mixed and further kneaded for 90 seconds, and then 15.0 parts of processing oil (manufactured by Shin-Nippon Oil Co., Ltd., trade name "Aromax T-DAE") was put. Thereafter, the starting temperature was 90° C. and kneading was carried out, and after kneading at 145° C. to 155° C. for 60 seconds or more (primary mixing), the kneaded product was discharged from the mixer.

After cooling the obtained kneaded product to room temperature, the mixture was again set to 90 ° C in a Banbury mixer and kneaded for 2 minutes (secondary mixing), and then discharged from the mixer. Refining. The temperature of the kneaded material at the end of the kneading was 145 °C.

Next, 1.7 parts of sulfur and a vulcanization accelerator: N-cyclohexyl-2-benzothiazolesulfenamide (N-cyclohexyl-2-benzothiazolesulfenamide) were added to the obtained kneaded product by using two rolls of 50 °C. CBS product name "NOCCELERCZ-G", manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.), and benzophenone (DPG trade name "NOCCELER D", manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) 1.7 copies, and these are mixed. After kneading (vulcanizing agent), a sheet-like rubber composition was taken out.

Further, the kneading conditions of the primary mixing, the secondary mixing, and the kneading agent kneading were set to the conditions shown below.

(Combination conditions for primary mixing and secondary mixing) ・Testing machine: LAYO PLASTOMILL Bamburi mixer B-600 manufactured by Toyo Seiki Co., Ltd. ・Filling rate: 70 to 75 vol% ・Rotor rotation number: 50 rpm ・Starting test Set temperature: 90 ° C

(Kneading conditions for vulcanizing agent kneading) ・Testing machine: Ikeda Machinery Co., Ltd. Electric heating type high temperature roller machine ・Roll size: 6φ×16 ・Front roller rotation number: 24 rpm ・ Front and rear roller rotation ratio: 1:1.22・Roller temperature: 50°C±5°C ・Flip times: 2 times left and right ・passing rounding width: Roller interval is about 0.8 mm ・Rolling into a cylinder: 5 times

[Examples 2 to 3 and Comparative Examples 1 to 3]

A rubber composition was obtained in the same manner as in Example 1 except that the hydrocarbon resin obtained in Production Examples 2 to 6 was used instead of the hydrocarbon resin obtained in Production Example 1 as shown in Table 2 below.

〔Evaluation〕

The rubber compositions obtained in the examples and the comparative examples were subjected to pressure crosslinking at a pressurization pressure of about 8 MPa and a pressurization temperature of 160 ° C for 40 minutes, and then matured in a constant temperature room at 23 ° C to prepare 150 mm. A test piece of a rubber crosslinked product of ×150 mm × 2 mm in thickness.

With respect to the rubber composition and the rubber cross-linked product obtained in the examples and the comparative examples, the Muini viscosity of the rubber composition, the tensile strength (MPa), the elongation (%), and the loss tangent tan δ of the rubber cross-linked product were measured. The results are shown in Table 2 below.

[Table 2]

From Tables 1 and 2, it was confirmed that in the examples, the loss tangent tan δ at 0 ° C was high and the loss tangent tan δ at 60 ° C was low. From this result, it was confirmed that both excellent rolling resistance and wet grip performance were obtained.

Further, in the case where the diene rubber and the hydrocarbon resin are contained, since the rolling resistance and the wet grip performance are excellent, it is confirmed that the rubber composition is excellent in excellent compatibility. The work becomes excellent in workability. Further, it has been confirmed that the rubber composition has excellent dispersibility of vermiculite and excellent workability even in the case of containing a filler such as vermiculite.

In other words, it can be confirmed from Tables 1 and 2 that a monomer unit having a structure in which two or more cyclic structures are combined is contained in a predetermined ratio, and has a specified weight average molecular weight (Mw), a softening point, and the like. The characteristics, especially, for example, with respect to the diene rubber, include a specified amount of a hydrocarbon resin and vermiculite, the hydrocarbon resin being a weight average molecular weight (Mw), and a ratio of a weight average molecular weight to a number average molecular weight (Mn) (Mw/Mn) It is a hydrocarbon resin which is moderately low and has a moderately high softening point, whereby the rubber composition is excellent in workability and has excellent rolling resistance and wet grip performance.

no.

Claims (5)

A rubber composition obtained by blending 1 to 30 parts by mass of a hydrocarbon resin and 80 to 2 parts by mass of vermiculite with respect to 100 parts by mass of the diene rubber, and the rubber composition is characterized in that The hydrocarbon resin is a monomer unit comprising an aliphatic monomer unit and an aromatic monomer unit; wherein the aromatic monomer unit has a structure in which two or more cyclic structures are combined; The content in the unit is 50% by mass or more; the weight average molecular weight (Mw) is in the range of 700 to 6,000, and the softening point is in the range of 80 to 150 °C. The rubber composition according to claim 1, wherein the hydrocarbon resin comprises: 1,3-pentadiene monomer unit 10% by mass to 60% by mass, and carbon number 4-6 alicyclic monoolefin monomer unit 1 1% by mass to 30% by mass, 1% by mass to 50% by mass of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms, 0% by mass to 10% by mass of the alicyclic diolefin monomer unit, and The aromatic monomer unit is 0.1% by mass to 50% by mass, the number average molecular weight (Mn) is in the range of 400 to 3,000, the Z average molecular weight (Mz) is in the range of 1,500 to 20,000, and the weight average molecular weight is relative to the number average molecular weight. The ratio (Mw/Mn) is in the range of 1.0 to 4.0, and the ratio (Mz/Mw) of the Z average molecular weight to the weight average molecular weight is in the range of 1.0 to 4.0. The rubber composition according to claim 1 or 2, wherein the single system having a structure in which two or more cyclic structures are combined is selected from the group consisting of a naphthalene compound, an anthracene compound, a biphenyl compound, an anthracene compound, and a phenanthrene compound. At least one of the group of hydrazine compounds and benzothiophene compounds. The rubber composition according to claim 1 or 2, wherein the hydrocarbon resin is the lowest in a state of a homogeneous solution by using a mixture of aniline, methylcyclohexane and the hydrocarbon resin (volume ratio 2:1:1) The value of the mixed aniline point measured by the temperature is in the range of 25 ° C to 100 ° C. A pneumatic tire characterized by using the rubber composition according to claim 1 or 2 for a tread.