WO2018101364A1 - Rubber composition and pneumatic tire - Google Patents

Abstract

The main purpose of the present invention is to provide a rubber composition which has excellent workability and has an excellent balance of rolling resistance and wet grip performance.　The present invention solves this problem by providing a rubber composition obtained by combining 1 part by mass to 200 parts by mass of a modified hydrocarbon resin per 100 parts by mass of a diene rubber, the rubber composition being characterized in that the modified hydrocarbon resin is a hydrocarbon resin that has been modified by at least one compound from among an amine compound, an amide compound, and an imide compound, the weight average molecular weight (Mw) of the modified hydrocarbon resin is in the range of 1000–8000, and the softening point of the modified hydrocarbon resin is in the range of 80°C–150°C.

Description

Rubber composition and pneumatic tire

The present invention relates to a rubber composition having excellent processability and excellent balance between rolling resistance and wet grip performance.

In recent years, automobile tires are strongly required to have low fuel consumption due to environmental problems and resource problems. On the other hand, in terms of safety, for example, improvement in wet grip properties is required. A cross-linked product of a rubber composition in which silica is added to a rubber component as a filler (hereinafter sometimes referred to simply as a “cross-linked rubber product”) constitutes a tire compared to a cross-linked product of a rubber composition in which carbon black is mixed. In this case, the rolling resistance is reduced. Therefore, a tire excellent in fuel efficiency can be obtained by constituting a tire using a crosslinked product of a rubber composition containing silica.

However, even if silica is blended with the conventional rubber component, the rubber component and silica have insufficient affinity, and due to their easy separation, the processability of the rubber composition before crosslinking is poor, Moreover, the rubber cross-linked product obtained by cross-linking this has a problem that the rolling resistance is insufficient when a tire is constituted.

Further, in Patent Document 1, by preparing a rubber composition using an amine-modified conjugated diene polymer as a rubber component, a pneumatic tire with reduced heat generation and improved run-flat running durability can be provided. Are listed. In Patent Document 2, by preparing a rubber composition using a hydrogenated conjugated diolefin-based polymer in which a polymer chain end is modified with an amide or an imide as a rubber component, the abrasion resistance, weather resistance, processability, etc. are improved. It is described that tires and the like that are excellent and generate little heat can be obtained.

JP 2011-255881 A JP 2000-53706 A

However, in the rubber components described in Patent Document 1 and Patent Document 2, when a tire is manufactured from a rubber crosslinked product obtained by adding the rubber component, both wet grip properties and rolling resistance characteristics can be improved in a balanced manner. There is a problem that it is difficult.

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

As a result of diligent investigation on the hydrocarbon resin added to the rubber composition together with the rubber component, the inventors have modified the hydrocarbon resin with a predetermined amount of an amine compound and have a weight within a predetermined range. The present invention finds that a modified hydrocarbon resin having predetermined characteristics such as average molecular weight is involved in improving the workability of the rubber composition and improving the balance of both rolling resistance and wet grip performance. It has come to be completed.

Thus, according to the present invention, there is provided a rubber composition comprising 1 part by mass to 200 parts by mass of a modified hydrocarbon resin per 100 parts by mass of a diene rubber. , Modified with at least one of an amine compound, an amide compound or an imide compound, the weight average molecular weight (Mw) is in the range of 1000 to 8000, and the softening point is in the range of 80 ° C. to 150 ° C. A rubber composition is provided.

The hydrocarbon resin is a C5 petroleum resin or a C5 / C9 petroleum resin, and the C5 petroleum resin or the C5 / C9 petroleum resin is 20% by mass to 70% by mass of a 1,3-pentadiene monomer unit. 5 to 35% by mass of alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, 1 to 50% by mass of acyclic monoolefin monomer unit having 4 to 8 carbon atoms, and alicyclic A hydrocarbon resin containing 0% by mass to 10% by mass of a diolefin monomer unit and 0% by mass to 50% by mass of an aromatic monoolefin monomer unit, and the modified hydrocarbon resin is the hydrocarbon resin 100 The mass part was obtained by modifying 0.01 parts by weight to 20 parts by weight of at least one compound selected from the group consisting of the amine compound, amide compound and imide compound, and the number average molecular weight (Mn) Is 500 Within the range of 4000, the Z average molecular weight (Mz) is within the range of 2000 to 25000, and the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) is within the range of 1.0 to 4.0. The ratio of the Z average molecular weight to the weight average molecular weight (Mz / Mw) is preferably in the range of 1.0 to 4.5.

Further, according to the present invention, there is provided a pneumatic tire characterized by using the above rubber composition for a tread.

The present invention has an effect that it is possible to provide a rubber composition which is excellent in workability and has a good balance between rolling resistance and wet grip performance.

The present invention relates to a rubber composition and a pneumatic tire using it as a tread. Hereinafter, the rubber composition and pneumatic tire of the present invention will be described in detail.

I. Rubber composition The rubber composition of the present invention is a rubber composition obtained by blending 1 part by mass to 200 parts by mass of a modified hydrocarbon resin with 100 parts by mass of a diene rubber. A hydrogen resin is modified with at least one of an amine compound, an amide compound or an imide compound, has a weight average molecular weight (Mw) in the range of 1000 to 8000, and a softening point of 80 ° C. to 150 ° C. It is characterized by being within the range.

According to the present invention, the rubber composition is, for example, at least one compound selected from the group consisting of an amine compound, an amide compound, and an imide compound (hereinafter sometimes referred to as an amine compound). By containing a predetermined amount of a modified hydrocarbon resin that is modified and has characteristics such as a predetermined weight average molecular weight and softening point with respect to the diene rubber, it is excellent in workability and has excellent rolling resistance and wet grip performance. A rubber composition excellent in balance can be obtained.

Here, by using the modified hydrocarbon resin, it is not clear why a rubber composition having excellent workability and a good balance of rolling resistance and wet grip performance can be obtained. Is inferred. That is, as a modified hydrocarbon resin, by using a hydrocarbon resin modified with an amine compound, as a typical example, when a filler is blended in a rubber composition, the affinity with the filler is increased, and the filler is dispersed. Can be improved. Furthermore, the compatibility with diene rubber can be made excellent by setting the molecular weight and softening point of the modified hydrocarbon resin to predetermined values. Therefore, the modified hydrocarbon resin is excellent in compatibility with the diene rubber, and is excellent in dispersion of fillers such as silica, so that the terminal group filler of the diene rubber can be used. By promoting the fixation, for example, with respect to the obtained rubber composition, the loss coefficient tan δ at 60 ° C. of the crosslinked product can be lowered, and the loss coefficient tan δ at 0 ° C. can be appropriately increased. As a result, when a tire is manufactured using such a rubber composition, it is possible to form a tire having an excellent balance between rolling resistance and wet grip performance.

From the above, by including a predetermined amount of the modified hydrocarbon resin with respect to the diene rubber, it is possible to obtain a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance. is there.

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

A. Modified hydrocarbon resin The modified hydrocarbon resin is a modified product of an amine compound of a hydrocarbon resin. Hereinafter, a hydrocarbon resin before being modified with an amine compound (hereinafter sometimes referred to as a resin before modification), an amine compound and a modified hydrocarbon resin for modifying this (hereinafter sometimes referred to as a modified resin). ) Will be described in detail.

1. Hydrocarbon resin The hydrocarbon resin is a raw material resin before being modified with an amine compound.

As such a hydrocarbon resin, any resin can be used as long as it can be modified with an amine compound to provide a rubber composition having excellent workability and a good balance between rolling resistance and wet grip performance. . In the present invention, the hydrocarbon resin is preferably a C5 petroleum resin or a C5 / C9 petroleum resin. This is because the petroleum resin can stably provide a rubber composition having excellent processability and excellent balance between rolling resistance and wet grip performance.

The C5-based petroleum resin is one which refers to a hydrocarbon resin obtained by naphtha by polymerizing a monomer composition comprising at least one monomer included in the C ₅ fraction obtained by thermal decomposition .

As the monomer contained in the C ₅ fraction, for example, 1,3-pentadiene, isoprene, cyclopentadiene can be mentioned conjugated diene monomer having a carbon number of 4-5 such as, among others in the present invention The monomer composition preferably contains 1,3-pentadiene as the C ₅ fraction, that is, the hydrocarbon resin preferably contains 1,3-pentadiene monomer units.

Incidentally, monomer, monomer naphtha may be included as C ₅ fraction or C ₉ fraction upon pyrolysis contained in C ₉ fraction described later and monomers contained in the C ₅ fraction If it is. For example, the monomer contained in the C ₅ fraction, naphtha is not limited to monomer was obtained as C ₅ fraction by thermal decomposition, it was obtained by other synthetic methods such as It may be a monomer.

The C5 / C9 petroleum resin, a monomer contained at least one and naphtha monomer include naphtha C ₅ fraction obtained by thermal decomposition to C ₉ fractions obtained by pyrolysis A hydrocarbon resin obtained by polymerizing a monomer containing at least one of the above.

Examples of the monomer contained in the C ₉ fraction include aromatic monoolefins having 8 to 10 carbon atoms such as styrene, α-methylstyrene, vinyltoluene, indene and coumarone.

More specifically, the C5 petroleum resin or C5 / C9 petroleum resin includes a 1,3-pentadiene monomer unit, an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, and A hydrocarbon resin containing at least an acyclic monoolefin monomer unit having 4 to 8 carbon atoms and, if necessary, an alicyclic diolefin monomer unit and an aromatic monoolefin monomer unit. Among them, 1,3-pentadiene monomer unit 20% by mass to 70% by mass, C 4-6 alicyclic monoolefin monomer unit 5% by mass to 35% by mass, carbon number 4 1 to 50% by mass of acyclic monoolefin monomer units of 8 to 8%, 0 to 10% by mass of alicyclic diolefin monomer units, and 0 to 10% by mass of aromatic monoolefin monomer units This is a hydrocarbon resin containing 50% by mass. It is preferred. The C5 petroleum resin or the C5 / C9 petroleum resin is the above-described hydrocarbon resin, that is, by using the hydrocarbon resin having the predetermined monomer unit and ratio as the pre-modification resin, the modification This is because the hydrocarbon resin can provide a rubber composition having excellent processability and excellent balance between rolling resistance and wet grip performance.

The content of the 1,3-pentadiene monomer unit in the resin before modification may be in the range of 20% by mass to 70% by mass, and may be in the range of 25% by mass to 67% by mass. In particular, it is preferably in the range of 30% by mass to 65% by mass, and particularly preferably in the range of 33% by mass to 63% by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

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

The alicyclic monoolefin having 4 to 6 carbon atoms is a hydrocarbon compound having 4 to 6 carbon atoms having one ethylenically unsaturated bond and a non-aromatic ring structure in its 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 resin before modification can be in the range of 5% by mass to 35% by mass, and is 8% by mass to 33% by mass. It is preferably within the range, and more preferably within the range of 10% by mass to 32% by mass, and particularly preferably within the range of 13% by mass to 30% by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

In the alicyclic monoolefin having 4 to 6 carbon atoms, the ratio of each of the corresponding compounds may be any ratio, and is not particularly limited, but preferably contains at least cyclopentene, and has 4 to 6 carbon atoms. The proportion of cyclopentene in the alicyclic monoolefin is more preferably 50% by mass or more.

An acyclic monoolefin having 4 to 8 carbon atoms is a chain hydrocarbon compound having 4 to 8 carbon atoms having one ethylenically unsaturated bond in its molecular structure and no ring structure. 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, 2-pentene, 2-methyl-1 -Pentenes such as butene, 3-methyl-1-butene, 2-methyl-2-butene; hexenes such as 1-hexene, 2-hexene, 2-methyl-1-pentene; 1-heptene, 2-heptene Heptenes such as 2-methyl-1-hexene; 1-octene, 2-octene, 2-methyl-1-heptene, diisobutylene (2,4,4-trimethyl-1-pentene and 2,4,4- Octenes such as trimethyl-1-pentene).

The content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the pre-modification resin can be in the range of 1% by mass to 50% by mass, and 5% by mass to 45% by mass. It is preferably within the range, more preferably within the range of 10% by mass to 42% by mass, and particularly preferably within the range of 15% by mass to 40% by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

In the acyclic monoolefin having 4 to 8 carbon atoms, the ratio of each of the corresponding compounds (including isomers) may be any ratio, and is not particularly limited. However, at least 2-methyl-2-butene, Preferably, at least one selected from the group consisting of isobutylene and diisobutylene is included, and the total amount of 2-methyl-2-butene, isobutylene and diisobutylene occupies in the acyclic monoolefin having 4 to 8 carbon atoms The ratio is more preferably 50% by mass or more.

The pre-modification resin may contain an alicyclic diolefin as a raw material. An alicyclic diolefin is a hydrocarbon compound having two or more ethylenically unsaturated bonds and a non-aromatic ring structure in its molecular structure. Specific examples of the alicyclic diolefin include multimers of cyclopentadiene such as cyclopentadiene and dicyclopentadiene, and multimers of methylcyclopentadiene and methylcyclopentadiene.

The content of the alicyclic diolefin monomer unit in the resin before modification may be in the range of 0% by mass to 10% by mass, and may be in the range of 0% by mass to 7% by mass. In particular, it is preferably in the range of 0% by mass to 5% by mass, and particularly preferably in the range of 0% by mass to 3% by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

The resin before modification may contain an aromatic monoolefin in its raw material. An aromatic monoolefin is an aromatic compound having one ethylenically unsaturated bond in its molecular structure. Specific examples of the aromatic monoolefin, styrene, alpha-methyl styrene, vinyl toluene, indene, aromatic monoolefin having 8 to 10 carbon atoms contained in the C ₉ fraction, such as coumarone.

The content of the aromatic monoolefin monomer unit in the resin before modification can be in the range of 0% by mass to 50% by mass, and preferably in the range of 0% by mass to 45% by mass. In particular, it is preferably in the range of 0% by mass to 43% by mass, and particularly preferably in the range of 0% by mass to 40% by mass.

In the aromatic monoolefin monomer unit, the ratio of each compound (including isomers) corresponding to the aromatic monoolefin monomer unit may be any ratio, and is not particularly limited, but the aromatic monoolefin having 8 to 10 carbon atoms is selected. The proportion of the total amount of the aromatic monoolefin having 8 to 10 carbon atoms is preferably 30% by mass or more, more preferably 40% by mass or more, and especially 50% by mass It is preferable that it is above, and it is particularly preferable that it is 60% by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

Resin before modification is 1,3-pentadiene monomer unit, alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, acyclic monoolefin monomer unit having 4 to 8 carbon atoms, alicyclic In addition to diolefin monomer units and aromatic monoolefin monomer units, it is possible to obtain a modified hydrocarbon resin that provides a rubber composition that is excellent in processability and has a good balance of rolling resistance and wet grip performance. As long as it is possible, other monomer units may be included.

Other monomers used for constituting such other monomer units may be compounds having addition polymerizability that can be addition copolymerized with 1,3-pentadiene or the like other than the aforementioned monomers. There is no particular limitation. Examples of the other monomers include carbon numbers other than 1,3-pentadiene such as 1,3-butadiene, 1,2-butadiene, isoprene, 1,3-hexadiene, and 1,4-pentadiene. An unsaturated monoolefin having 7 or more carbon atoms such as cycloheptene; an acyclic monoolefin having 4 to 8 carbon atoms such as ethylene, propylene and nonene.

However, the content of the other monomer units in the resin before modification in the resin before modification is not particularly limited as long as the modified hydrocarbon resin having the predetermined characteristics can be obtained. Usually, it is in the range of 0% by mass to 30% by mass, 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. This is because the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

The method for producing the pre-modification resin is not particularly limited as long as the polymerizable component (monomer mixture A) having a monomer capable of constituting the above-described monomer unit is suitably subjected to addition polymerization. For example, the resin before modification can be obtained by addition polymerization using a Friedel-Crafts type cationic polymerization catalyst.

As a method suitably used for producing the pre-modified resin, the following aluminum halide (A), halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom, and a carbon-carbon bond are used. In combination with a halogenated hydrocarbon (B) selected from the group consisting of halogenated hydrocarbons (B2) in which a halogen atom is bonded to a carbon atom adjacent to the saturated bond, a polymerization catalyst is used, The method which has the superposition | polymerization process to superpose | polymerize can be mentioned.

Moreover, the addition amount of each monomer contained in the monomer mixture A can be the same as the content of each monomer unit in the hydrocarbon resin. Therefore, as the pre-modification resin, 1,3-pentadiene monomer unit 20 mass% to 70 mass%, alicyclic monoolefin monomer unit 4 to 6 carbon atoms 5 mass% to 35 mass%, carbon number 4 1 to 50% by mass of acyclic monoolefin monomer units of 8 to 8%, 0 to 10% by mass of alicyclic diolefin monomer units, and 0 to 10% by mass of aromatic monoolefin monomer units In the case of producing a hydrocarbon resin containing 50% by mass, the above production method is more specifically, 5% by mass of 1,3-pentadiene 20% by mass to 70% by mass and C 4-6 alicyclic monoolefin. % To 35% by mass, 1 to 50% by mass of acyclic monoolefin having 4 to 8 carbon atoms, 0 to 10% by mass of alicyclic diolefin, and 0 to 50% by mass of aromatic monoolefin A polymerization step of polymerizing the monomer mixture A containing How to you can be cited.

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

The amount of aluminum halide (A) used is not particularly limited, but is preferably in the range of 0.05 to 10 parts by mass, more preferably 100 parts by mass of the polymerizable component (monomer mixture A). It is within the range of 0.1 to 5 parts by mass.

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

Specific examples of the halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom include t-butyl chloride, t-butyl bromide, 2-chloro-2-methylbutane, and triphenylmethyl chloride. . Among these, t-butyl chloride is particularly preferably used because it has an excellent balance between activity and ease of handling.

Examples of the unsaturated bond in the halogenated hydrocarbon (B2) in which a halogen atom is bonded to a carbon atom adjacent to the carbon-carbon unsaturated bond include a carbon-carbon double bond and a carbon-carbon triple bond, and an aromatic ring It also includes a carbon-carbon conjugated double bond in Specific examples of such compounds include benzyl chloride, benzyl bromide, (1-chloroethyl) benzene, allyl chloride, 3-chloro-1-propyne, 3-chloro-1-butene, 3-chloro-1-butyne, Examples include cinnamon chloride. Among these, benzyl chloride is preferably used because it is excellent in balance between activity and ease of handling. In addition, halogenated hydrocarbon (B) may be used by 1 type, or may be used in combination of 2 or more types.

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

In performing the polymerization reaction, the order of adding each component of the monomer mixture and the polymerization catalyst to the polymerization reactor is not particularly limited, and may be added in any order, but the polymerization reaction is well controlled, From the viewpoint of more accurately controlling the weight average molecular weight and the like, after adding the monomer mixture and a part of the components of the polymerization catalyst to the polymerization reactor and starting the polymerization reaction, the remainder of the polymerization catalyst is subjected to the polymerization reaction It is preferable to add to the vessel.

In producing the pre-modification resin, it is preferable to first mix the aluminum halide (A) and the alicyclic monoolefin. This is because by subjecting the aluminum halide (A) and the alicyclic monoolefin to contact treatment, gel formation can be prevented, and a pre-modified resin in which the weight average molecular weight and the like are accurately controlled can be obtained.

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

When mixing the aluminum halide (A) and the alicyclic monoolefin, the charging order is not particularly limited, and the aluminum halide (A) may be charged into the alicyclic monoolefin, and conversely, An alicyclic monoolefin may be introduced into the aluminum halide (A). Since mixing usually involves exotherm, an appropriate diluent can also be used. As the diluent, a solvent described later can be used.

After preparing a mixture M of an aluminum halide (A) and an alicyclic monoolefin as described above, a mixture a containing at least 1,3-pentadiene and an acyclic monoolefin is mixed with the mixture M. It is preferable to do. The mixture a may contain an alicyclic diolefin.

The preparation method of the mixture a is not particularly limited, and each of the pure compounds may be mixed to obtain the target mixture a. For example, a mixture containing the target monomer derived from a fraction of a naphtha decomposition product May be used to obtain the desired mixture a. For example, in order to incorporate 1,3-pentadiene or the like into the mixture a, the C5 fraction after extraction of isoprene and cyclopentadiene (including its multimer) can be preferably used.

It is preferable to further mix the halogenated hydrocarbon (B) together with the mixture a and the mixture M. There are no particular restrictions on the order of these three parties.

From the viewpoint of better controlling the polymerization reaction, it is preferable to carry out the polymerization reaction by adding a solvent to the polymerization reaction system. The type of the solvent is not particularly limited as long as it does not inhibit the polymerization reaction, but saturated aliphatic hydrocarbons or aromatic hydrocarbons are preferable. Examples of the saturated aliphatic hydrocarbon used as the solvent include n-pentane, n-hexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, and 3-ethylpentane. , 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane, 2,2,4-trimethylpentane, etc. Examples include 5-10 chain saturated aliphatic hydrocarbons; cyclic saturated aliphatic hydrocarbons having 5 to 10 carbon atoms such as cyclopentane, cyclohexane, cycloheptane, cyclooctane and the like. Examples of the aromatic hydrocarbon used as the solvent include aromatic hydrocarbons having 6 to 10 carbon atoms such as benzene, toluene and xylene. A solvent may be used individually by 1 type and may be used as a 2 or more types of mixed solvent. The amount of the solvent used is not particularly limited, but is preferably in the range of 10 parts by weight to 1,000 parts by weight with respect to 100 parts by weight of the polymerizable component (monomer mixture A), and 50 parts by weight to More preferably, it is in the range of 500 parts by weight. 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 the C5 fraction is added to the polymerization reaction system, and the addition polymerizable component is a single amount. It can be used as a component of the body mixture, and the non-addition polymerizable component can be used as a solvent.

The polymerization temperature for carrying out the polymerization reaction is not particularly limited, but is preferably in the range of −20 ° C. to 100 ° C., and preferably in the range of 0 ° C. to 75 ° C. If the polymerization temperature is too low, the polymerization activity may be lowered and productivity may be inferior. If the polymerization temperature is too high, controllability such as the weight average molecular weight of the resin before modification may be inferior. The pressure for performing the polymerization reaction may be atmospheric pressure or increased pressure. The polymerization reaction time can be appropriately selected, but is usually selected within the range of 10 minutes to 12 hours, preferably 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 when a desired polymerization conversion rate is obtained.

The method for producing the pre-modified resin has at least the polymerization step, but may have other steps as necessary. Examples of the other steps include, for example, a catalyst residue that is generated when a polymerization terminator is added in the polymerization step after the polymerization step to inactivate the polymerization catalyst, and the catalyst residue insoluble in the solvent is removed by filtration or the like. After the polymerization reaction is stopped by the removal step and the polymerization step, the unreacted monomer and solvent are removed, and the low molecular weight oligomer component is removed by steam distillation or the like, followed by cooling to obtain a solid unmodified resin. It can have a recovery process.

2. Amine-based compound The amine-based compound is at least one compound selected from the group consisting of an amine compound, an amide compound, and an imide compound.

(1) Amine compound The amine compound is a compound having an amine structure in which 0 to 2 hydrogen atoms and one or more hydrocarbon groups are covalently bonded to nitrogen.

The amine compound has an amine structure, and the modified hydrocarbon resin only needs to provide a rubber composition having excellent workability and excellent balance of rolling resistance and wet grip performance. For example, those having a hydrocarbon group bonded to the nitrogen atom within the range of 1 to 3, that is, primary amine, secondary amine and tertiary amine can be used.

As the hydrocarbon group, an aliphatic hydrocarbon group and an aromatic hydrocarbon group can be used. In addition, the aromatic hydrocarbon group refers to a group in which the site directly bonded to the nitrogen atom is an aromatic ring, and even if it has an aromatic ring such as a benzyl group, the site bonded directly to the nitrogen atom Those in which is not an aromatic ring are included in the aliphatic hydrocarbon group.

The aliphatic hydrocarbon group may include any structure of a chain aliphatic group and a cyclic aliphatic group, or may include an unsaturated group. Furthermore, the cyclic aliphatic group and the aromatic hydrocarbon group may be a carbocyclic group containing only carbon as an atom constituting the cyclic structure, but may be a heterocyclic group containing an atom other than carbon.

Furthermore, as the aliphatic hydrocarbon group and the aromatic hydrocarbon group, a substituted product in which a hydrogen atom contained in the aliphatic hydrocarbon group and the aromatic hydrocarbon group is substituted with a substituent can also be used. As a substituent, at least one of a hydrogen atom, an aliphatic hydrocarbon group, and an aromatic hydrocarbon group is bonded via an atom other than carbon such as an amine structure or a nitrogen atom such as —OCH ₃ , an oxygen atom, or a sulfur atom. Can be mentioned. Therefore, as the amine compound, if the modified hydrocarbon resin is capable of providing a rubber composition having excellent workability and a good balance between rolling resistance and wet grip performance, an amine in the molecule can be used. It is not limited to the monoamine which has only one structure, For example, diamine, a triamine etc. which have the 2 or more amine structure covalently bonded through the said hydrocarbon group can also be used. When the amine compound has two or more amine structures, the two or more amine structures may be the same structure or different structures. For example, an amine compound includes two amine structures, a primary amine structure and a secondary amine structure, includes two secondary amine structures, and one secondary amine structure is the other secondary amine structure. The hydrocarbon groups bonded to nitrogen may have different structures.

The molecular weight of the amine compound is not particularly limited as long as it can be stably bonded to the resin before modification, and can be, for example, in the range of 50 to 500, particularly in the range of 100 to 300. Preferably there is.

Examples of the primary amine include amines in which aliphatic hydrocarbon groups having a total of 6 to 20 carbon atoms in the compound are bonded as hydrocarbon groups such as 1-hexylamine, 1-heptylamine, 1-octylamine, and the like. Examples of the hydrocarbon group include amines to which heteroaromatic groups contained in an aromatic hydrocarbon group are bonded, and among them, amines to which a total of 8 to 12 carbon atoms in the compound are bonded. Can be preferably used.

Examples of the secondary amine include 1,6-bis (ethylamino) hexane, 1,2-bis (tert-butylamino) ethane, N′-benzyl-N, N-dimethylethylenediamine, and N-benzyl-N. , N′-dimethylethylenediamine and other hydrocarbon groups in which a total of 6 to 20 carbon atoms of aliphatic hydrocarbon groups are bonded, and heteroaromatic groups contained in aromatic hydrocarbon groups are bonded as hydrocarbon groups Among them, amines to which aliphatic hydrocarbon groups having 8 to 12 carbon atoms in total in the compound are bonded can be preferably used.

Examples of the tertiary amine include fatty acids having 6 to 20 carbon atoms in total in the compound as hydrocarbon groups such as N′-benzyl-N, N-dimethylethylenediamine and N-benzyl-N, N′-dimethylethylenediamine. Examples include amines to which aromatic hydrocarbon groups are bonded, and amines to which heteroaromatic groups contained in aromatic hydrocarbon groups are bonded as hydrocarbon groups. Among them, fatty acids having 8 to 12 carbon atoms in total in the compound An amine or the like to which an aromatic hydrocarbon group is bonded can be preferably used.

In addition, when it has a secondary amine structure and a tertiary amine structure such as N′-benzyl-N, N-dimethylethylenediamine, the amine compound corresponds to both the secondary amine and the tertiary amine. It is.

Further, N′-benzyl-N, N-dimethylethylenediamine has (1) benzyl group (carbon number 7) and (2) ethylene group (—C ₂ H ₅ ) as hydrocarbon groups constituting the secondary amine structure. In which one hydrogen atom has an aliphatic hydrocarbon group (—C ₂ H ₄ —N— (CH ₃ ) ₂ : carbon number 4) substituted with an amine structure, and has at least 7 carbon atoms. Having a hydrocarbon group. Further, N′-benzyl-N, N-dimethylethylenediamine has (1) two methyl groups (1 carbon number) and (2) ethylene group (—C ₂ H) as hydrocarbon groups constituting the tertiary amine structure. ₅ ) wherein one hydrogen atom has an aliphatic hydrocarbon group (— (C ₂ H ₄ ) —NH—CH ₂ —C ₆ H ₅ : carbon number 9) substituted with an amine structure, It has at least an aliphatic hydrocarbon group having 9 carbon atoms.

Examples of the diamine include 1,6-bis (ethylamino) hexane, 1,2-bis (tert-butylamino) ethane, 1,4-di (aminomethyl) cyclohexane, 4-amino-1-diethylaminopentane, N -Amine having a total of 6 to 20 carbon atoms bonded as a hydrocarbon group, such as benzyl-N, N'-dimethylethylenediamine, in the compound, or a complex contained in an aromatic hydrocarbon group as a hydrocarbon group Examples include amines to which aromatics are bonded, and among these, amines to which aliphatic hydrocarbon groups having 8 to 12 carbon atoms in total in the compound are bonded can be preferably used.

Examples of the triamine include amines and carbons bonded with aliphatic hydrocarbon groups having a total of 6 to 20 carbon atoms in the compound as hydrocarbon groups such as bis (4-aminobutyl) amine and bis (6-aminohexyl) amine. Examples of the hydrogen group include amines to which a heteroaromatic group contained in an aromatic hydrocarbon group is bonded. Among them, amines to which a total of 8 to 12 carbon atoms of an aliphatic hydrocarbon group in the compound are bonded. It can be preferably used.

The amine compound may contain only one type or may contain two or more types.

(2) Amide compound The amide compound may be a compound having one or more amide bonds in the molecule, and for example, a compound represented by the following formula (1) can be used.

(In formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom or a hydrocarbon group.)

The hydrocarbon group in R ¹ to R ³ can be the same as that described in the section “(1) Amine compound”. R ¹ to R ³ may be the same functional group or different functional groups.

In addition, the hydrocarbon group in R ¹ to R ³ can provide a rubber composition in which the modified hydrocarbon resin is excellent in workability and has a good balance of rolling resistance and wet grip performance. It suffices that a part of the hydrogen atoms of the aliphatic hydrocarbon group and aromatic hydrocarbon group contained as the hydrocarbon group is substituted with an amide structure or an amine structure. That is, the amide compound is not limited to a monoamide having only one amide structure in the molecule, but has two or more amide structures covalently bonded via R ¹ to R ³ as the hydrocarbon group, For example, diamide, triamide and the like can be used. The amide compound may have an amide structure and an amine structure bonded via R ¹ to R ³ as the hydrocarbon group.

The molecular weight of the amide compound is not particularly limited as long as it can be stably bonded to the resin before modification, and can be, for example, in the range of 50 to 500, particularly in the range of 100 to 300. Preferably there is.

As the amide compound, specifically, an amide compound described in JP-A-2000-53706 can be used, and more specifically, N, N-dimethylformamide, acetamide, N, N-diethylacetamide , Aminoacetamide, N, N-dimethyl-N ′, N′-dimethylaminoacetamide, N, N-dimethylaminoacetamide, N, N-ethylaminoacetamide, N, N-dimethyl-N′-ethylaminoacetamide, acrylamide N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, nicotinamide, isonicotinamide, picolinic acid amide, N, N-dimethylisonicotinamide, succinic acid amide, phthalic acid amide, N, N, N ′ , N′-tetramethylphthalamide, oxamide and N N, N ′, N′-tetramethyloxamide, 2-furancarboxylic acid amide, N, N-dimethyl-2-furancarboxylic acid amide, quinoline-2-carboxylic acid amide, N-ethyl-N-methyl-quinoline Examples thereof include carboxylic acid amides and N-acetylethylenediamine. Among them, N-acetylethylenediamine and the like can be preferably used.

The amide compound may include only one type or may include two or more types.

(3) Imide compound As said imide compound, what is necessary is just a compound which has one or more imide bonds in a molecule | numerator, For example, the cyclic imide compound represented by following formula (2) or (3) can be used.

(R ⁴ , R ⁵ and R ⁶ and R ⁷ , R ⁸ and R ⁹ in formulas (2) and (3) are each independently a hydrogen atom or a hydrocarbon group.)

The hydrocarbon group for R ⁴ to R ⁹ can be the same as that described in the section “(1) Amine compound”. R ⁴ to R ⁹ may be the same functional group as each other or different functional groups.

In addition, the hydrocarbon groups in R ⁴ to R ⁹ are those that can give a rubber composition in which the modified hydrocarbon resin has excellent workability and a good balance between rolling resistance and wet grip performance. It suffices that a part of the hydrogen atoms of the aliphatic hydrocarbon group and aromatic hydrocarbon group contained as the hydrocarbon group is substituted with an imide structure, an amide structure or an amine structure. That is, the imide compound is not limited to a monoimide having only one imide structure in the molecule, and has two or more imide structures bonded via R ⁷ to R ⁹ as the hydrocarbon group. Diimide, triimide and the like can also be used. The imide compound may have an amide structure and at least one of an amide structure and an amine structure bonded via R ⁷ to R ⁹ as the hydrocarbon group.

The molecular weight of the imide compound is not particularly limited as long as it can stably bind to the resin before modification, and can be, for example, in the range of 50 to 500, and in particular, in the range of 100 to 300. Preferably there is.

As the imide compound, specifically, an imide compound described in JP-A-2000-53706 can be used, and more specifically, succinimide, N-methyl succinimide, maleimide, N-methyl. Maleimide, phthalimide, N-methylphthalimide, bismaleimide and the like can be mentioned, and among them, N-alkylmaleimide compounds such as N-methylmaleimide can be preferably used.

The imide compound may contain only one type or may contain two or more types.

(4) Amine compound The amine compound is at least one compound selected from the group consisting of an amine compound, an amide compound, and an imide compound. Accordingly, the amine compound may include only an amine compound, only an amide compound, or only an imide compound, and may include two types of compounds, an amine compound and an amide compound, an amine compound, It may contain three kinds of compounds, an amide compound and an imide compound. In the present invention, the amine compound preferably includes an amide compound.

The modified hydrocarbon resin is obtained by modifying the hydrocarbon resin with an amine compound.

Here, “obtained by modification” means that the amine compound is bonded to the hydrocarbon resin by a covalent bond.

The product obtained by modifying 100 parts by mass of a hydrocarbon resin with 0.01 to 20 parts by mass of an amine compound is derived from an amine compound that is bonded to 100 parts by mass of the hydrocarbon resin. This means that the mass of the site to be within the range of 0.01 to 20 parts by mass.

The content of the amine compound, that is, the content of the site derived from the amine compound bonded to 100 parts by mass of the hydrocarbon resin as the pre-modified resin is in the range of 0.01 to 20 parts by mass. It is preferably in the range of 0.1 to 10 parts by weight, more preferably in the range of 0.1 to 8 parts by weight, It is preferably in the range of 5 to 5 parts by mass. This is because when the content is within the above range, the modified hydrocarbon resin can provide a rubber composition having excellent workability and excellent balance between rolling resistance and wet grip performance.

As the amine modification method of the pre-modification resin using the amine compound, any method can be used as long as the amine compound can be covalently bonded to the pre-modification resin. As such an amine modification method, a known method can be appropriately used. Specifically, as the above-mentioned amine modification method, by mixing a resin before modification, an amine compound and a peroxide initiator, free peroxide is generated in the resin before modification by the peroxide initiator. Can be used, such as a method of reacting an amine compound with an amine compound, a method of mixing an amine compound with a pre-denaturing resin having an active terminal, and the like.

In the above-described amine modification method, the amount of the amine compound added to the pre-modified resin may be any amount that can bind a desired amount of the amine compound. For example, the amine compound in the modified hydrocarbon resin. The amount can be the same amount or more.

The reaction conditions in the amine modification method using free radicals described above are not particularly limited as long as a desired amount of amine compound can be bound to the resin before modification, and the kind of resin before modification and the kind of amine compound. For example, the reaction temperature may be 0 ° C. to 200 ° C. and the reaction time may be 5 minutes to 20 hours.

The amine modification method can also be performed in an organic solvent, for example. Such an organic solvent may be the same as the solvent that can be used for the polymerization reaction of the pre-modification resin described in the section “1. Hydrocarbon resin”. The amine modification method may be, for example, a method in which amine modification is performed in a solvent used in polymerization of a resin before modification.

The peroxide initiator is not particularly limited as long as it can bind a desired amount of an amine compound to the resin before modification. For example, an inorganic peroxide such as sodium persulfate, diisopropylbenzene hydroperoxide, etc. Known peroxide initiators such as organic peroxides can be used. As such inorganic peroxide, organic peroxide, etc., for example, those described in JP-A-2004-285230 can be used.

The amount of the peroxide initiator used is not particularly limited as long as a desired amount of the amine compound can be bound to the pre-modification resin, and is appropriately set according to the addition amount of the amine compound. .

The amine modification method may be a method of bonding an amine compound to the resin before modification via a known silane coupling agent, if necessary. In addition, about the method of couple | bonding a silane coupling agent with resin before modification | denaturation, it can be made to be the same as that of the above-mentioned amine modification method.

As the silane coupling agent, for example, a bifunctional silane coupling agent having a vinyl group and a reactive functional group capable of binding to a nitrogen atom contained in an amine compound can be used. Examples of the functional group for reaction include a hydroxyl group, a carboxy group, a ketone group, an epoxy group, a halogen group, and a sulfonic acid group. Among them, a hydroxyl group, a carboxyl group, and the like are preferable. In addition, about the bifunctional silane coupling agent which has such a vinyl group and the functional group for reaction, it can select suitably from a well-known silane coupling agent.

In addition, the amount of the silane coupling agent used as a spacer between the amine compound and the resin before modification, including those not bonded to the amine compound, is usually included as part of the resin before modification. It is what

Examples of the method for bonding the pre-modified resin bonded with the silane coupling agent and the amine compound include, for example, a method in which the pre-modified resin bonded with the silane coupling agent and the amine compound are mixed and heat-treated. Can do.

As the above heat treatment conditions, for example, the heat treatment may be performed within a temperature range of 50 ° C. to 300 ° C. for 5 minutes to 20 hours.

In the above heat treatment, a diluent, an antigelling agent, a reaction accelerator and the like may be present as necessary. Such a diluent may be the same as the solvent that can be used for the polymerization reaction of the pre-modification resin described in the section “1. Hydrocarbon resin”. The heat treatment may be performed, for example, in a solvent used in the polymerization of the resin before modification.

Moreover, as the above-mentioned amine modification method, a method in which an amine compound is bonded to a resin before modification by reacting a nitrogen atom of the amine compound with an acidic group such as a carboxyl group or an acid anhydride group contained in the resin before modification. It may be.

As for the acidic group, an acidic group introduced into the resin before modification by using a polymerizable component (monomer mixture A) containing a monomer having an acidic group may be used. The acidic group introduced by doing so may be used.

Here, as a method of acid-modifying the resin before modification, a known method can be used. For example, when introducing a carboxyl group as an acidic group, the resin before modification and an unsaturated carboxylic acid are mixed and heated. The method of processing can be mentioned. The acid modification method may include a method in which an acid anhydride group is introduced as an acidic group, and the resin before modification and the unsaturated dicarboxylic acid anhydride are mixed and heat-treated.

Examples of unsaturated carboxylic acids used for introducing carboxyl groups include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like, and ethylenically unsaturated carboxylic acids having 8 or less carbon atoms, and Examples include Diels-Alder adducts of conjugated dienes such as 3,6-endomethylene-1,2,3,6-tetrahydrophthalic acid and α, β-unsaturated dicarboxylic acids having 8 or less carbon atoms.

Examples of unsaturated dicarboxylic acid anhydrides used for introducing acid anhydride groups include α, β-unsaturated dicarboxylic acid anhydrides having 8 or less carbon atoms such as maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. Examples include Diels-Alder adducts of conjugated dienes such as 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride and α, β-unsaturated dicarboxylic anhydrides having 8 or less carbon atoms. It is done.

In addition, the blending amount of an acid modifier such as an unsaturated carboxylic acid introduced to acid-modify such a pre-modification resin, including those not bound to an amine compound, is usually It is included as a part.

As the reaction conditions for the acid modification reaction, for example, the reaction can be performed within a temperature range of 50 ° C. to 300 ° C. for 5 minutes to 20 hours.

The acid modification reaction may contain a diluent, an anti-gelling agent, a reaction accelerator and the like as necessary.

In addition, examples of the reaction for bonding an acidic group and an amine compound include a method in which a resin before modification or a resin before modification after acid modification and an amine compound are mixed and heat-treated. About the method of heat-processing, it can be made to be the same as that of the heat processing method which couple | bonds the resin before modification | denaturation which the above-mentioned silane coupling agent couple | bonded, and an amine compound, for example.

In the following formulas (4) to (6), the above amine modification method uses maleic anhydride as the unsaturated dicarboxylic anhydride, and the resin A before modification into which the carboxylic anhydride group as an acidic group has been introduced, The example which is a method of obtaining the modification | denaturation hydrocarbon resin B by making an amine compound react is shown. Moreover, following formula (4) shows the example which uses the diamine compound containing two amine structures as an amine compound. Further, the following formulas (5) and (6) show examples in which an amide compound containing an amine structure and an amide structure is used as the amine compound, and the formula (5) shows an amide structure contained in the amine compound. Is reacted with an acidic group, and formula (6) shows an example in which a nitrogen atom of an amine structure contained in an amine compound reacts with an acidic group.

In the above-mentioned amine modification reaction, a secondary modification reaction in which an amine compound bonded to a modified hydrocarbon resin further reacts with a modified hydrocarbon resin after the primary modification reaction in which the amine compound is bonded to the pre-modified resin. It may be.

As the secondary modification reaction, for example, as shown in the following formulas (7) and (8), an amine structure or an amide structure contained in an amine compound bonded to the modified hydrocarbon resin may be further modified. And the like which react with an acidic group or the like contained in the like.

Further, the secondary modification reaction may occur for the same modified hydrocarbon resin as the modified hydrocarbon resin bonded by the primary modification reaction, or may occur for a different modified hydrocarbon resin or a pre-modified resin, It may produce a crosslinked modified hydrocarbon resin.

In the formula (7), the secondary modification reaction is such that the nitrogen atom of the amine structure contained in the amine compound bonded to the modified hydrocarbon resin reacts with an acidic group contained in the same modified hydrocarbon resin. Thus, an example of newly generating an amide structure will be shown. Further, the formula (8) shows that the secondary modification reaction is carried out with respect to the same acidic group as that in which the nitrogen atom of the amide structure contained in the amine compound bonded to the modified hydrocarbon resin is reacted with the amine compound. An example in which a cyclic imide structure is newly generated by reacting again is shown.

3. Modified Hydrocarbon Resin The weight average molecular weight (Mw) of the modified hydrocarbon resin is not particularly limited as long as it is within the range of 1,000 to 8,000, but among these, 1,200 to 6,000. Is preferably within the range of 1,400 to 4,500, and more preferably within the range of 1,400 to 4,500. This is because when the weight average molecular weight (Mw) is within the above-mentioned range, the modified hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. of the cross-linked product of the rubber composition, and can be excellent in rolling resistance. Further, when the weight average molecular weight (Mw) is within the above-mentioned range, the modified hydrocarbon resin can easily increase the loss coefficient tan δ at 0 ° C. and has excellent rolling resistance. Because it can.

The number average molecular weight (Mn) of the modified hydrocarbon resin can be in the range of 500 to 4000, preferably in the range of 550 to 3000, particularly in the range of 600 to 2500. It is more preferable. This is because when the number average molecular weight (Mn) is within the above range, the modified hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. of the cross-linked product of the rubber composition, and can be excellent in rolling resistance.

The modified hydrocarbon resin may have a Z average molecular weight (Mz) in the range of 2,000 to 25,000, particularly preferably in the range of 3,000 to 20,000. , Preferably in the range of 4,000 to 15,000. This is because when the Z average molecular weight (Mz) is within the above range, the modified hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. of the cross-linked product of the rubber composition, and can be excellent in rolling resistance.

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 modified hydrocarbon resin are determined as polystyrene-converted values measured by high performance liquid chromatography. For the measurement of number average molecular weight, weight average molecular weight and Z average molecular weight, more specifically, “HLC-8320GPC” manufactured by Tosoh Corporation is used as a measuring apparatus, and three “TSKgel SuperMultipleHZ” manufactured by Tosoh Corporation are connected. And measured with a tetrahydrofuran as a solvent at 40 ° C. and a flow rate of 1.0 mL / min.

The ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight of the modified hydrocarbon resin can be in the range of 1.0 to 4.0, and more preferably in the range of 1.2 to 3.5. It is preferably within the range, and more preferably within the range of 1.4 to 3.0. This is because when the ratio is within the above range, the modified hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. with respect to the crosslinked product of the rubber composition and can be excellent in wet grip performance. .

The ratio of the Z average molecular weight to the weight average molecular weight (Mz / Mw) of the modified hydrocarbon resin can be in the range of 1.0 to 4.5, and in particular, in the range of 1.0 to 4.0. It is preferably within the range, and more preferably within the range of 1.0 to 3.5. This is because when the ratio is within the above range, the modified hydrocarbon resin can be excellent in compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. with respect to the crosslinked product of the rubber composition and can be excellent in wet grip performance. .

The softening point of the modified hydrocarbon resin is not particularly limited as long as it is in the range of 80 ° C. to 150 ° C. Among them, it is preferably in the range of 85 ° C. to 145 ° C., particularly 90 ° C. It is more preferable that the temperature be within a range of ˜140 ° C. This is because when the softening point is within the above-described range, the modified hydrocarbon resin can have excellent compatibility with the diene rubber. As a result, the modified hydrocarbon resin can easily reduce the loss coefficient tan δ at 60 ° C. of the cross-linked product of the rubber composition, and can be excellent in rolling resistance. In addition, since the softening point is within the above range, the modified hydrocarbon resin can easily increase the loss coefficient tan δ at 0 ° C. and can have excellent wet grip performance. is there.

The softening point in the present invention is a value measured according to JIS K 6863 for a modified hydrocarbon resin, for example.

The amount of the modified hydrocarbon resin is not particularly limited as long as it is 1 to 200 parts by mass with respect to 100 parts by mass of the diene rubber, but 1 part by mass with respect to 100 parts by mass of the diene rubber. It is preferably in the range of ˜70 parts by mass, more preferably in the range of 3 parts by mass to 35 parts by mass. This is because, when the blending amount is within the above-described range, the rubber composition has excellent processability and excellent balance between rolling resistance and wet grip performance. In addition, the blending amount of the modified hydrocarbon resin includes two or more kinds of modified hydrocarbon resins, such as those in which the modified hydrocarbon resin is a modified C5 petroleum resin and a modified C5 / C9 petroleum resin. When included, the total amount of all the modified hydrocarbon resins can be obtained.

As the method for producing the modified hydrocarbon resin, a method having an amine modification step of modifying 100 parts by mass of the hydrocarbon resin, which is a resin before modification, with 0.01 to 20 parts by mass of the amine compound is used. it can. The method of modifying with the amine compound, that is, the amine modifying method, and the like can be the same as the contents described in the above section “2. Amine compound”, and thus the description thereof is omitted here. .

B. Diene Rubber As the diene rubber, any diene rubber that can be blended with the modified hydrocarbon resin in 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 rubbers are natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR). ), Ethylene-propylene-diene terpolymer (EPDM), etc., among which styrene-butadiene copolymer rubber, butadiene rubber and the like are preferable. This is because by using the diene rubber, it is possible to obtain a rubber composition having excellent workability and a good balance between rolling resistance and wet grip performance. The diene rubber need only contain at least one kind, and may contain only one kind, or a mixture of two or more kinds.

Further, the molecular weight and microstructure of the diene rubber are not particularly limited, and may be terminally modified with an amine, amide, silyl, alkoxysilyl, carboxyl, hydroxyl group or the like, or may be epoxidized. The diene rubber may be hydrogenated, but is preferably not hydrogenated.

C. Other Components The rubber composition of the present invention contains a diene rubber and a modified hydrocarbon resin, but may contain other components as necessary.

Examples of the other components include compounding agents such as a silane coupling agent, a crosslinking agent, a crosslinking accelerator, a crosslinking activator, an anti-aging agent, an activator, a process oil, a plasticizer, a lubricant, and a tackifier. Necessary amount can be blended. Such other components and their contents can be the same as those described in JP-A-2016-30795, for example.

The above other components can contain a filler. As said filler, what is generally used for a rubber composition can be used, for example, carbon black, clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, In addition to aluminum hydroxide, various metal powders, wood powder, glass powder, ceramic powder, inorganic hollow fillers such as glass balloons and silica balloons; organic hollow fillers made of polystyrene, polyvinylidene fluoride, polyvinylidene fluoride copolymers, etc. Etc. Among these fillers, for example, silica, carbon black and the like described in JP-A-2016-30795 can be used.

In the present invention, among these, the filler is preferably silica or carbon black, and particularly preferably silica. This is because the rubber composition is excellent in wet grip properties by being the filler.

Further, the filler only needs to contain at least one type, and may contain only one type, or a mixture of two or more types. For example, the filler can be used by mixing silica and carbon black.

The content of the filler is not particularly limited as long as it is excellent in processability and can provide a rubber composition excellent in the balance between rolling resistance and wet grip performance. The content can be, for example, in the range of 10 parts by mass to 200 parts by mass with respect to 100 parts by mass of the diene rubber, and more preferably in the range of 30 parts by mass to 150 parts by mass. In particular, it is preferably in the range of 50 to 70 parts by mass. This is because the rubber composition has excellent processability and wet grip properties when the content is within the above-described range.

D. Rubber composition The rubber composition of the present invention may be prepared by kneading each component according to a conventional method. For example, a component excluding a thermally unstable component such as a crosslinking agent or a crosslinking accelerator and a diene rubber are used. After kneading, a heat-unstable component such as a crosslinking agent or a crosslinking accelerator can be mixed with the kneaded product to obtain a desired composition. The kneading temperature of the component excluding the thermally unstable component and the diene rubber is preferably in the range of 80 ° C. to 200 ° C., more preferably in the range of 120 ° C. to 180 ° C., and the kneading time is preferably Is 30 seconds to 30 minutes. The kneaded product and the thermally unstable component are usually mixed after cooling to 100 ° C. or lower, preferably 80 ° C. or lower.

As a crosslinking method using the rubber composition of the present invention as a rubber crosslinked product, a known crosslinking method can be used. For example, a molding machine corresponding to a desired shape, such as an extruder, an injection molding machine, a compressor, Examples of the method include forming by a roll or the like, performing a crosslinking reaction by heating, and fixing the shape as a crosslinked product. In this case, it is possible to perform crosslinking after molding in advance or at the same time as molding. The molding temperature is usually in the range of 10 ° C to 200 ° C, 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, preferably 2 minutes to 12 hours. And particularly preferably within the range of 3 minutes to 6 hours.

Further, depending on the shape, size, etc. of the rubber cross-linked product, even if the surface is cross-linked, it may not be sufficiently cross-linked to the inside. Good.

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

The rubber composition of the present invention has an excellent balance between rolling resistance and wet grip performance. The rubber composition of the present invention is preferably used as a material for each part of the tire such as a tread (cap tread, base tread), carcass, sidewall, bead portion, etc. of the tire, taking advantage of such characteristics. In particular, in various tires such as all-season tires, high-performance tires, and studless tires, it can be suitably used for tire parts such as treads, carcass, sidewalls, and bead portions, and particularly excellent in low heat generation. Therefore, it can be particularly suitably used as a tread for a fuel-efficient tire, and in particular, it is preferably used for a cap tread.

II. Pneumatic tire Next, the pneumatic tire of the present invention will be described. The pneumatic tire of the present invention is characterized by using the above rubber composition in a tread.

The tread is one that uses the above rubber composition, that is, one that is formed using the rubber composition, and usually contains a cross-linked product of the rubber composition.

Since the rubber composition used for forming such a tread and its cross-linked product can be the same as those described in the above section “I. Rubber composition”, the description thereof is omitted here.

The pneumatic tire only needs to have a tread formed using the rubber composition, and other parts may also be formed using the rubber composition.

The tread formed using the rubber composition may be a part of the tread or the entire tread, but preferably includes at least a cap tread.

Moreover, as a manufacturing method of the pneumatic tire of this invention, what is necessary is just a method which can manufacture the pneumatic tire which has the tread formed using the said composition, and using the manufacturing method of a well-known pneumatic tire is used. it can.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the part and% in each example are a mass reference | standard unless there is particular notice.

Various measurements were performed according to the following methods.

[Number average molecular weight, weight average molecular weight, Z average molecular weight and molecular weight distribution]
About the modified hydrocarbon resin as a sample, gel permeation chromatography analysis is performed to determine the number average molecular weight (Mn), the weight average molecular weight (Mw) and the Z average molecular weight (Mz) in terms of standard polystyrene. It was shown by the ratio of Mw / Mn and Mz / Mw. The gel permeation chromatography analysis uses “HLC-8320GPC” manufactured by Tosoh Corporation as a measuring device, and the column uses three connected “TSKgel SuperMultipore HZ” manufactured by Tosoh Corporation, with tetrahydrofuran as a solvent. , 40 ° C. and a flow rate of 1.0 mL / min.

[Softening point (℃)]
The modified hydrocarbon resin as a sample was measured according to JIS K 6863.

[Mooney viscosity (ML1 + 4)]
The rubber composition as a sample was measured according to JIS K 6300-1: 2001 under the following conditions. About this characteristic, it showed with the index | exponent which makes a reference | standard sample (after-mentioned comparative example 1) 100.
Test temperature: 100 ° C
・ Rotor type: L type ・ Testing machine: Shimadzu Mooney Viscometer SMV-300J manufactured by Shimadzu Corporation

[Tensile strength (MPa), elongation (%), and 200% elongation tensile stress (MPa)]
About the test piece of rubber crosslinked material used as a sample, according to JIS K 6251: 2010, tensile strength (tensile stress (MPa)), elongation (elongation (%)), and 200% tensile stress (tensile stress (tensile stress (%)) MPa)). About these characteristics, it showed with the index | exponent which makes a reference sample (comparative example 1 mentioned later) 100. The 200% tensile strength ((MPa)) is a value obtained by dividing the tensile force when 200% elongation is given to the test piece by the initial cross-sectional area of the test piece.
-Test piece preparation method: After sheet preparation by press vulcanization, punching process-Test piece shape: Dumbbell shape No. 3-Specimen sampling direction: Parallel to line arrangement-Number of test pieces: 3
・ Measurement temperature: 23 ℃
・ Test speed: 500 mm / min
-Test machine: TENSOMETER ₁₀ 0k manufactured by ALPHA TECHNOLOGIES
・ Test machine capacity: Load cell type 1kN

[Loss tangent tan δ]
The loss tangent tan δ at 0 ° C. and 60 ° C. was measured under the following measurement conditions under the following measurement conditions for the test piece of the crosslinked rubber product as a sample under the following measurement conditions: . About this characteristic, it showed with the index | exponent which makes a reference | standard sample (after-mentioned comparative example 1) 100. The higher the loss tangent tan δ at 0 ° C., the better the wet grip performance, and the lower the loss tangent tan δ at 60 ° C., the better the rolling resistance.
Measurement item: Dynamic storage elastic modulus E '
: Dynamic loss modulus E ''
: Loss tangent tan δ
-Sample preparation method: punching from sheet-Specimen shape: length 50 mm x width 2 mm x thickness 2 mm
・ Number of specimens: 1
・ Distance between clamps: 20mm

[Production Example 1]
A polymerization reactor was charged with a mixture of 47.3 parts of cyclopentane and 28.3 parts of cyclopentene. The temperature was raised to 70 ° C., and then 0.75 part of aluminum chloride was added (mixture M ₁ ). Subsequently, from 63.6 parts of 1,3-pentadiene, 6.2 parts of isobutylene, 0.1 part of dicyclopentadiene, 0.3 part of C4-C6 unsaturated hydrocarbon, and 5.7 parts of C4-C6 saturated hydrocarbon the mixture a ₁ comprising, maintaining the temperature (70 ° C.) for 60 minutes, was subjected to a continuous polymerization while adding to the polymerization reactor containing the mixture M _1. Thereafter, an aqueous sodium hydroxide solution was added to the polymerization reactor to stop the polymerization reaction. Table 1 summarizes the types and amounts of the components in the polymerization reactor during the polymerization reaction. After removing the precipitate generated by the termination of polymerization by filtration, the obtained polymer solution was charged into a distillation kettle and heated in a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers. Next, the oligomer component having a low molecular weight was distilled off at 240 ° C. or higher while blowing saturated water vapor.

For 100 parts of molten resin, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: Irganox 1010, manufactured by BASF) as an antioxidant. 0.2 part was added, and then 2.0 parts of maleic anhydride was added, followed by addition reaction at 230 ° C. for 1 hour. And an addition reaction was carried out at 200 ° C. for 1 hour. Thereafter, the molten resin was taken out from the distillation kettle and allowed to cool to room temperature to obtain a modified hydrocarbon resin of Production Example 1. About the obtained modified hydrocarbon resin of Production Example 1, the number average molecular weight, weight average molecular weight, Z average molecular weight, molecular weight distribution, and softening point were measured. These measurement results are summarized in Table 1 below.

The values of amine compound (parts) / resin before modification (100 parts) in Table 1 were calculated using maleic anhydride used for acid modification as part of the raw material of the resin before modification. The addition amount (parts) of an amine compound per 100 parts in total of the monomer mixture constituting the pre-modification resin described in 1 and maleic anhydride.

[Production Examples 2 to 8]
A modified hydrocarbon resin was obtained in the same manner as in Production Example 1 except that the type and amount of components added to the polymerization reactor and the polymerization temperature were changed as shown in Table 1 below. For the resins of Production Examples 2 to 8 obtained, the number average molecular weight, weight average molecular weight, Z average molecular weight, molecular weight distribution, and softening point were measured in the same manner as the modified hydrocarbon resin of Production Example 1.

Note that diisobutylene, aromatic monoolefin and toluene not described in Production Example 1 were mixed with 1,3-pentadiene and the like, and subjected to polymerization. Styrene was used as the aromatic monoolefin.

Further, in Production Example 6 and Production Example 7, an unmodified hydrocarbon resin was obtained without performing acid modification with maleic anhydride and amine modification with an amine compound.

[Example 1]
Oil-extended emulsion-polymerized styrene butadiene rubber (SBR) (trade name “Nipol 1739”, manufactured by Nippon Zeon Co., Ltd., bound styrene content: 40%, vinyl bond content of butadiene unit: 13.5 mol in a Banbury mixer %, Weight average molecular weight: 690,000, molecular weight distribution (Mw / Mn): 3.98, glass transition temperature (Tg): -35 ° C., containing 37.5 parts of extended oil with respect to 100 parts of diene rubber ) 96.3 parts (diene rubber content: 70 parts, extender oil content: 26.3 parts) and solution polymerized butadiene rubber (BR) (trade name “Nipol BR1220”, manufactured by Nippon Zeon Co., Ltd., butadiene unit) Vinyl bond content of part: 2 mol%, weight average molecular weight: 490,000, molecular weight distribution (Mw / Mn): 2.52, Mooney viscosity (ML1 + 4, 100 ° C.) 44, 30.0 parts of glass transition temperature (Tg): −110 ° C.) for 30 seconds, and then 46.6 parts of silica (trade name “Zeosil 1165MP” manufactured by Rhodia), carbon black (Cabot Japan ( Co., Ltd., trade name “N339”) 5.0 parts, silane coupling agent: bis [3- (triethoxysilyl) propyl] tetrasulfide (Degussa, trade name “Si69”) 6.0 parts After adding 10.0 parts of the modified hydrocarbon resin obtained in Production Example 1 and kneading for 90 seconds, 23.4 parts of silica (trade name “Zeosil 1165MP” manufactured by Rhodia), 3.0 parts of zinc oxide, stearic acid 2.0 parts and anti-aging agent: N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine (manufactured by Ouchi Shinsei Co., Ltd., trade name “NOCRACK 6C”) 2 Was added to 0 parts, and more for 90 seconds kneaded, then, process oil (Nippon Oil Co., Ltd. under the trade name "allo-Max T-DAE") 5.0 parts was charged. Thereafter, the mixture was kneaded at 90 ° C. as a starting temperature, kneaded at 145 ° C. to 155 ° C. for 60 seconds or more (primary kneading), and then the kneaded product was discharged from the mixer.

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

Next, with two rolls at 50 ° C., the obtained kneaded product was mixed with 1.7 parts of sulfur and a vulcanization accelerator: N-cyclohexyl-2-benzothiazolylsulfenamide (CBS trade name “NOXELLA CZ-G”). "1.8 parts of Ouchi Shinsei Chemical Co., Ltd.) and 1.7 parts of diphenylguanidine (DPG product name" Noxeller D ", Ouchi Shinsei Chemical Co., Ltd.) are added and kneaded (mixed with vulcanizing agent) After kneading, the sheet-like rubber composition was taken out.

The kneading conditions for primary kneading, secondary kneading and vulcanizing agent kneading were as shown below.

(Kneading conditions for primary and secondary kneading)
・ Testing machine: Labo Plast Mill, Banbury mixer B-600 manufactured by Toyo Seiki Seisakusho Co., Ltd.
・ Filling rate: 70-75 vol%
・ Rotor speed: 50rpm
・ Test start set temperature: 90 ℃

(Kneading conditions for vulcanizing agent)
・ Testing machine: Ikeda Machine Industries Co., Ltd. electric heating type high temperature roll machine ・ Roll size: 6φ × 16
-Front roll speed: 24rpm
-Front / rear roll rotation ratio: 1: 1.22
・ Roll temperature: 50 ℃ ± 5 ℃
・ Number of turn-over: Twice left and right ・ Rounding width: Roll interval approx. 0.8mm
・ Number of rounding: 5 times

[Examples 2 to 5 and Comparative Examples 1 to 3]
As shown in Table 2 below, instead of the modified hydrocarbon resin obtained in Production Example 1, modified hydrocarbon resins obtained in Production Examples 2 to 8 (Production Examples 6 to 7 are unmodified hydrocarbon resins). A rubber composition was obtained in the same manner as in Example 1 except that it was used.

[Evaluation]
The rubber compositions obtained in the examples and comparative examples were press-crosslinked at a press pressure of about 8 MPa and a press temperature of 160 ° C. for 40 minutes, and then aged overnight in a thermostatic chamber at 23 ° C., and then 150 mm × 150 mm × thickness. A test piece of 2 mm rubber cross-linked product was prepared.

For the rubber compositions and rubber cross-linked products obtained in Examples and Comparative Examples, the Mooney 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.

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

In addition, when a diene rubber and a modified hydrocarbon resin are included, the rubber composition is excellent in both rolling resistance and wet grip performance. It was confirmed that Moreover, even when the said rubber composition contains fillers, such as a silica, it has confirmed that the dispersibility of a filler was favorable and became what was excellent in workability.

That is, from Table 1 and Table 2, those modified with a predetermined amount of an amine compound and having characteristics such as a predetermined weight average molecular weight and softening point, particularly, for example, weight average molecular weight (Mw) and weight average molecular weight The rubber composition contains a predetermined amount of a modified hydrocarbon resin having a moderately low ratio (Mw / Mn) to the number average molecular weight (Mn) and a moderately high softening point relative to the diene rubber. It was confirmed that the film was excellent in both rolling resistance and wet grip performance.

Claims (3)

1. For 100 parts by mass of diene rubber,
   A rubber composition comprising 1 part by mass to 200 parts by mass of a modified hydrocarbon resin.
   The modified hydrocarbon resin is
   A hydrocarbon resin is modified with at least one compound of an amine compound, an amide compound or an imide compound,
   A rubber composition having a weight average molecular weight (Mw) in the range of 1000 to 8000 and a softening point in the range of 80 ° C to 150 ° C.
2. The hydrocarbon resin is a C5 petroleum resin or a C5 / C9 petroleum resin,
   The C5 petroleum resin or C5 / C9 petroleum resin is
   1,3-pentadiene monomer unit 20 mass% to 70 mass%,
   5 to 35% by mass of an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms,
   1 to 50% by mass of an acyclic monoolefin monomer unit having 4 to 8 carbon atoms,
   A hydrocarbon resin containing 0% by mass to 10% by mass of an alicyclic diolefin monomer unit and 0% by mass to 50% by mass of an aromatic monoolefin monomer unit;
   The modified hydrocarbon resin is
   Obtained by modifying 100 parts by mass of the hydrocarbon resin with 0.01 to 20 parts by mass of at least one compound selected from the group consisting of the amine compound, amide compound and imide compound,
   The number average molecular weight (Mn) is in the range of 500 to 4000,
   The Z average molecular weight (Mz) is in the range of 2000 to 25000,
   The ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) is in the range of 1.0 to 4.0,
   The rubber composition according to claim 1, wherein the ratio of the Z average molecular weight to the weight average molecular weight (Mz / Mw) is in the range of 1.0 to 4.5.
3. A pneumatic tire using the rubber composition according to claim 1 or 2 for a tread.