JP2020070329A - Rubber composition and pneumatic tire using the same - Google Patents

Abstract

To provide a rubber composition capable of giving a rubber crosslinked product excellent in rolling resistance and wear resistance.SOLUTION: The rubber composition is provided which contains a diene rubber, a hydrocarbon resin hydride, and silica. The content of the hydrocarbon resin hydride is 1-30 pts.mass based on 100 pts.mass of the diene rubber. The content of the silica is 80-200 pts.mass based on 100 pts.mass of the diene rubber. The hydrocarbon resin hydride is obtained by hydrogenating a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit and has a hydrogenation rate within the range of 0.1-80%, a weight average molecular weight (Mw) within the range of 700-6,000, and a softening point within the range of 80-150°C.SELECTED DRAWING: None

Description

  TECHNICAL FIELD The present invention relates to a rubber composition, and more particularly to a rubber composition capable of obtaining a rubber cross-linked product having excellent rolling resistance and abrasion resistance.

  In recent years, automobile tires have been strongly required to have low fuel consumption due to environmental problems and resource problems, and have been required to have improved wet grip properties from the viewpoint of safety. A crosslinked product of a rubber composition in which silica is added to a rubber component as a filler (hereinafter, may be simply referred to as a rubber crosslinked product) constitutes a tire as compared with a crosslinked product of a rubber composition in which carbon black is mixed. If so, the rolling resistance becomes smaller. Therefore, by constructing a tire using a cross-linked product of a rubber composition containing silica, a tire having excellent fuel economy can be obtained.

  However, even if silica is blended with the conventional rubber component, the affinity between the rubber component and silica is insufficient, and due to the fact that these are easily separated, the processability of the rubber composition before crosslinking is poor, Further, the rubber cross-linked product obtained by cross-linking these has a problem that rolling resistance in the case of forming a tire becomes insufficient.

  Therefore, in Patent Document 1, 1 part by mass to 30 parts by mass of a hydrocarbon resin and 80 parts by mass of silica are used with respect to 100 parts by mass of a diene rubber for the purpose of improving workability, rolling resistance of a tire, and wet grip properties. Parts to 200 parts by mass, wherein the hydrocarbon resin contains an aliphatic monomer unit and an aromatic monomer unit, and 2 or more of the aromatic monomer units are included. The content of the monomer unit having a structure in which the cyclic structure is bound in the aromatic monomer unit is 50% by mass or more, the weight average molecular weight (Mw) is in the range of 700 to 6000, and A rubber composition having a softening point in the range of 80 ° C to 150 ° C has been proposed.

  However, Patent Document 1 does not consider a rubber composition for obtaining a rubber crosslinked product having excellent rolling resistance and abrasion resistance.

International Publication No. 2018/101361

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rubber composition capable of obtaining a crosslinked rubber excellent in rolling resistance and abrasion resistance.

  The inventors of the present invention conducted a study to achieve the above object and found that a specific hydrocarbon resin was hydrogenated to have a specific hydrogenation rate and a rubber composition containing a specific amount of silica. If so, it is found that at the same time as having excellent workability, a rubber crosslinked product having excellent tensile strength, elongation and wet grip properties, and particularly excellent rolling resistance and abrasion resistance can be obtained, and the present invention It came to completion.

  That is, according to the present invention, a rubber composition containing a diene rubber, a hydrocarbon resin hydride, and silica, wherein the content of the hydrocarbon resin hydride is 100 parts by mass of the diene rubber. 1 to 30 parts by mass, the content of silica is 80 to 200 parts by mass with respect to 100 parts by mass of the diene rubber, and the hydrocarbon resin hydride is an aliphatic monomer unit and an aromatic compound. It is a product obtained by hydrogenating a hydrocarbon resin containing a group monomer unit, the hydrogenation rate is within the range of 0.1 to 80%, and the weight average molecular weight (Mw) is 700 to 6,000. Provided is a rubber composition having a softening point in the range of 80 to 150 ° C.

In the rubber composition of the present invention, the hydrocarbon resin is 1,3-pentadiene monomer unit 10 to 60% by mass, C4 to C6 alicyclic monoolefin monomer unit 1 to 30% by mass, 1 to 50% by mass of acyclic monoolefin monomer unit having 4 to 8 carbon atoms, 0 to 10% by mass of alicyclic diolefin monomer unit, and 0.1 to 50% by mass of the aromatic monomer unit. %, The hydrocarbon resin hydride has a number average molecular weight (Mn) in the range of 400 to 3,000, and a Z average molecular weight (Mz) in the range of 1,500 to 20,000. 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, and the ratio of the Z average molecular weight to the weight average molecular weight (Mz / Mw) is 1.0 to 4.0. It is preferably within the range.
In the rubber composition of the present invention, it is preferable that the aromatic monomer contains at least one selected from the group consisting of a styrene compound, an indene compound, and a C9 fraction.

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

  ADVANTAGE OF THE INVENTION According to this invention, the rubber composition which can obtain the rubber crosslinked material excellent in rolling resistance and abrasion resistance can be provided.

  Hereinafter, each component of the rubber composition of the present invention will be described.

<Hydrocarbon resin hydride>
The hydrocarbon resin hydride used in the present invention is obtained by hydrogenating a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit, and has a hydrogenation rate of 0.1 to 80%. Is in the range, 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 hydrocarbon hydride used in the present invention is obtained by hydrogenating a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit.
In the following, first, a hydrocarbon resin before hydrogenation (hereinafter, may be simply referred to as a hydrocarbon resin) will be described in detail, and then a hydrocarbon resin hydride obtained by hydrogenating this hydrocarbon resin will be described. ,explain.

<Hydrocarbon resin>
The hydrocarbon resin is a raw material resin before hydrogenation and contains an aliphatic monomer unit and an aromatic monomer unit.

(Aliphatic monomer unit)
The aliphatic monomer for forming the aliphatic monomer unit does not include an aromatic ring and may be at least an unsaturated hydrocarbon, and examples of such an aliphatic monomer include: 1, 1,3-pentadiene, alicyclic monoolefin monomers having 4 to 6 carbon atoms, acyclic monoolefin monomers having 4 to 8 carbon atoms, alicyclic diolefin monomers and the like. it can.

  The hydrocarbon resin is, as an aliphatic monomer unit, a 1,3-pentadiene unit, an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, and an acyclic monoolefin monomer having 4 to 8 carbon atoms. It is preferable to contain a unit, and in addition to these, an alicyclic diolefin monomer unit may be further contained.

  The content of the 1,3-pentadiene monomer unit in the hydrocarbon resin is preferably 10 to 60% by mass, more preferably 15 to 55% by mass, further preferably 20 to 50% by mass, and particularly preferably. Is 25 to 48 mass%. By setting the content of the monomer unit derived from 1,3-pentadiene in the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced. The cis / trans isomer ratio in 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 4 to 6 carbon atoms and 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, methylcyclopentene and the like.

  The content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms in the hydrocarbon resin is preferably 1 to 30% by mass, more preferably 3 to 28% by mass, and further preferably 5 to 5. 26% by mass, particularly preferably 7 to 25% by mass. By setting the content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms within the above range, it is possible to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

  In addition, as a C4-C6 alicyclic monoolefin, the ratio of each compound applicable to this may be an arbitrary ratio, although it is not particularly limited, it is preferable that at least cyclopentene is contained, It is more preferable that the proportion of cyclopentene in the alicyclic monoolefin of to 6 is 50% by mass or more.

  The acyclic monoolefin having 4 to 8 carbon atoms is a chain hydrocarbon compound having 1 to 8 ethylenically unsaturated bonds in its molecular structure and having 4 to 8 carbon atoms and having 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 , 2-methyl-1-hexene and other heptenes; 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); and the like.

  The content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the hydrocarbon resin is preferably 1 to 50% by mass, more preferably 5 to 45% by mass, and further preferably 10 to 42% by mass, particularly preferably 15 to 40% by mass. By setting the content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

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

  The hydrocarbon resin used in the present invention may contain an alicyclic diolefin as a raw material. The 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 cyclopentadiene, dicyclopentadiene and other cyclopentadiene multimers, methylcyclopentadiene, methylcyclopentadiene multimers and the like.

  The content of the alicyclic diolefin monomer unit in the hydrocarbon resin is preferably 0 to 10% by mass, more preferably 0 to 7% by mass, further preferably 0 to 5% by mass, particularly preferably Is 0 to 3% by mass. When the content is within the above range, rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  Further, the hydrocarbon resin used in the present invention includes, as an aliphatic monomer unit, a monomer unit derived from 1,3-pentadiene described above, an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms, and a carbon atom. In addition to the acyclic monoolefin monomer units of the formulas 4 to 8 and the alicyclic diolefin monomer units, other aliphatic monomer units are contained within a range in which the effects of the present invention can be obtained. Good.

  The other aliphatic monomer used to form such another aliphatic monomer unit is a compound other than the above-mentioned aliphatic monomer and is adducted with 1,3-pentadiene or the like. The compound is not particularly limited as long as it is a compound having an addition polymerizability capable of being polymerized. Examples of the above-mentioned other aliphatic monomer include carbon atoms other than 1,3-pentadiene such as 1,3-butadiene, 1,2-butadiene, isoprene, 1,3-hexadiene, 1,4-pentadiene and the like. Unsaturated hydrocarbons having 6 to 6 carbon atoms; alicyclic monoolefins having 7 or more carbon atoms such as cycloheptene; acyclic monoolefins having 3 or less carbon atoms or 9 or more carbon atoms such as ethylene, propylene and nonene;

  The content of the above other monomer units in the hydrocarbon resin is not particularly limited as long as the effects of the present invention can be obtained, but is preferably 0 to 30 mass%, more preferably 0. -25 mass%, more preferably 0-20 mass%.

  The content of the aliphatic monomer unit in the hydrocarbon resin is preferably 50 to 99.9% by mass, more preferably 55 to 95% by mass, further preferably 57 to 92% by mass, and particularly preferably It is 60 to 90 mass%. By setting the content of the aliphatic monomer unit in the above range, it is possible to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

(Aromatic monomer unit)
The aromatic monomer for forming the aromatic monomer unit may have an aromatic ring and can be copolymerized with an aliphatic monomer, for example, styrene and α-methyl. Styrene compounds such as styrene and vinyltoluene; indene, methylindene, ethylindene, propylindene, butylindene, t-butylindene, sec-butylindene, n-pentylindene, 2-methyl-butylindene, 3-methyl-butyl. Indene compounds such as indene, n-hexylindene, 2-methyl-pentylindene, 3-methyl-pentylindene, 4-methyl-pentylindene; 1-vinylnaphthalene, 2-vinylnaphthalene, allylnaphthalene, butenylnaphthalene, etc. Naphthalene compound; 2,7-divinylfluorene, 2-vinylfluorene Fluorene compounds such as len, allylfluorene and butenylfluorene; biphenyl compounds such as 4-vinylbiphenyl and 4-vinyl-p-terphenyl; 9-vinylanthracene, 2-vinylanthracene, 9,10-divinylanthracene, allylanthracene Anthracene compounds such as butenylanthracene; phenanthrene compounds such as 9-vinylphenanthrene and 3-vinylphenanthrene; benzothiophene compounds such as 5-vinylbenzothiophene and 2-vinylbenzothiophene; and the like. Among these, Styrene compounds and indene compounds are preferable, and styrene and indene are more preferable. These aromatic monomers may be used alone or in combination of two or more. Moreover, you may add the mixture containing these aromatic monomers to the polymerization reaction system at the time of manufacturing a hydrocarbon resin. At this time, the aromatic monomer contained in the mixture is used as a component of the monomer unit constituting the hydrocarbon resin. The addition-polymerizable component other than the aromatic monomer contained in the mixture may be used as the constituent component of the monomer unit of the hydrocarbon resin, and the non-addition-polymerizable component may be used as the solvent during the polymerization. .. As the mixture containing such an aromatic monomer, for example, a C9 fraction containing a styrene compound, an indene compound or the like as the aromatic monomer can be preferably used.

  Further, when the hydrocarbon resin contains, as an aromatic monomer unit, a monomer unit having a structure in which two or more cyclic structures are bonded, the resulting rubber cross-linked product has higher rolling resistance and abrasion resistance. be able to.

  The monomer constituting the monomer unit having a structure in which two or more cyclic structures are bonded is usually one or more aliphatic carbon-carbon unsaturated bond in the molecular structure and two or more cyclic structures. And a structure in which are bonded are preferably used. Here, the structure in which two or more cyclic structures are bonded may be one having at least one aromatic ring among the two or more cyclic structures, and a structure containing only an aromatic ring may be an aromatic ring. It may include a ring and a non-aromatic ring structure. The content of the monomer unit having a structure in which two or more cyclic structures are bonded in the hydrocarbon resin is preferably 0.1 to 50% by mass, more preferably 5 to 45% by mass, and further preferably 8%. ˜43% by mass, particularly preferably 10 to 40% by mass. By setting the content of the monomer unit having a structure in which two or more cyclic structures are bonded within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  As the above-mentioned aliphatic carbon-carbon unsaturated bond, any radical-polymerizable one may be used, and a vinyl group can be preferably used. When the monomer having a structure in which two or more cyclic structures are bonded is indene, the aliphatic carbon-carbon unsaturated bond is included as a part of the five-membered ring of indene.

  As the monomer having a structure in which two or more cyclic structures are bonded, a naphthalene compound, a fluorene compound, a biphenyl compound, an anthracene compound, a phenanthrene compound, an indene compound and a benzothiophene compound are preferable, an indene compound is more preferable, and indene is More preferable.

  The content of the aromatic monomer unit in the hydrocarbon resin is preferably 0.1 to 50% by mass, more preferably 5 to 45% by mass, further preferably 8 to 43% by mass, and particularly preferably 10%. -40 mass%. By setting the content of the aromatic monomer unit within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

The hydrocarbon resin in the present invention has a 1,3-pentadiene monomer unit of 10 to 60 mass%, an alicyclic monoolefin monomer unit of 4 to 6 carbon atoms of 1 to 30 mass%, and a carbon number of 4 to 8. It may contain 1 to 50% by mass of an acyclic monoolefin monomer unit, 0 to 10% by mass of an alicyclic diolefin monomer unit, and 0.1 to 50% by mass of the aromatic monomer unit. preferable. By including such a hydrocarbon resin, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.
The content ratio of the above-mentioned monomer unit is the same in the hydride of the hydrocarbon resin, and the suitable range of the content ratio is the same as that of the hydrocarbon resin.

(Method for producing hydrocarbon resin before hydrogenation)
The method for producing the hydrocarbon resin is not particularly limited as long as the polymerizable component (monomer mixture A) having the above-mentioned aliphatic monomer and aromatic monomer is preferably addition-polymerized. For example, a hydrocarbon resin can be obtained by addition polymerization using a Friedel-Crafts type cationic polymerization catalyst.

  Suitable methods for producing a hydrocarbon resin include, for example, aluminum halide (A) described below, halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom, and carbon- 1,3-Pentadiene 10 comprising a polymerization catalyst in combination with a halogenated hydrocarbon (B) selected from the group consisting of a halogenated hydrocarbon (B2) in which a halogen atom is bonded to a carbon atom adjacent to a carbon unsaturated bond. -60 mass%, C4-6 alicyclic monoolefin 10-30 mass%, C4-8 acyclic monoolefin 1-50 mass%, alicyclic diolefin 0-10 mass%, And a method having a polymerization step of polymerizing a monomer mixture A containing 0.1 to 50 mass% of an aromatic monomer.

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

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

  Further, in the polymerization, 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) having a halogen atom bonded to a tertiary carbon atom as the halogenated hydrocarbon (B) include t-butyl chloride, t-butyl bromide, and 2-chloro-2-methylbutane. , Triphenylmethyl chloride and the like. Among these, t-butyl chloride is particularly preferably used because of its excellent balance between activity and handleability.

  The unsaturated bond in the halogenated hydrocarbon (B2) in which a halogen atom is bonded to the carbon atom adjacent to the carbon-carbon unsaturated bond as the halogenated hydrocarbon (B) includes a carbon-carbon double bond and a carbon- A carbon triple bond is included, and a carbon-carbon conjugated double bond in an aromatic ring or the like is also included. 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 of its excellent balance between activity and handleability.

  The halogenated hydrocarbon (B) may be used alone or in combination of two or more.

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

  In carrying out the polymerization reaction, the order of adding the respective components of the monomer mixture and the polymerization catalyst to the polymerization reactor is not particularly limited and may be added in any order, but by controlling the polymerization reaction well, From the viewpoint of further increasing the rolling resistance and abrasion resistance of the obtained rubber cross-linked product, the monomer mixture and a part of the components of the polymerization catalyst are added to the polymerization reactor to start the polymerization reaction, and then the polymerization catalyst. The method of adding the rest of the above to the polymerization reactor is preferred.

  Specifically, in producing a hydrocarbon resin, it is preferable to first mix aluminum halide (A) and an alicyclic monoolefin in advance. By performing the contact treatment in which the aluminum halide (A) and the alicyclic monoolefin are mixed in advance, it is possible to prevent the formation of gel and to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

  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 reduced. The mass ratio of the alicyclic monoolefin and the aluminum halide (A) is a mass ratio of “alicyclic monoolefin: aluminum halide (A)”, preferably 5: 1 to 120: 1, and more preferably It is 10: 1 to 100: 1, more preferably 15: 1 to 80: 1. If the alicyclic monoolefin is used in a larger amount than this ratio, the catalytic activity may be lowered and the polymerization may not be sufficiently advanced.

  When preliminarily mixing the aluminum halide (A) and the alicyclic monoolefin, the order of introducing them is not particularly limited, and the aluminum halide (A) may be introduced into the alicyclic monoolefin, Conversely, an alicyclic monoolefin may be added to the aluminum halide (A). Mixing is usually exothermic, so a suitable diluent can be used. As the diluent, the solvent described below can be used.

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

  The method for preparing the mixture a is not particularly limited, and pure compounds may be mixed to obtain the desired mixture a, for example, a desired monomer derived from a fraction of a naphtha decomposition product is contained. The desired mixture a may be obtained using the mixture. For example, in order to mix 1,3-pentadiene and the like in the mixture a, the C5 fraction obtained after extraction of isoprene and cyclopentadiene (including multimers thereof) can be preferably used.

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

  From the viewpoint of better controlling the polymerization reaction, it is preferable to add a solvent to the polymerization reaction system to carry out the polymerization reaction. The type of 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 a solvent include n-pentane, n-hexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane. Carbon number of 2,2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane, 2,2,4-trimethylpentane 5-10 chain saturated aliphatic hydrocarbons; cyclopentane, cyclohexane, cycloheptane, cyclooctane, and other cyclic saturated aliphatic hydrocarbons having 5-10 carbon atoms. Examples of the aromatic hydrocarbon used as the solvent include aromatic hydrocarbons having 6 to 10 carbon atoms such as benzene, toluene and xylene. The solvent may be used alone or as a mixed solvent of two or more kinds.

  The amount of the solvent used is not particularly limited, but is preferably 10 to 1,000 parts by mass, more preferably 50 to 500 parts by mass, relative to 100 parts by mass of the polymerizable component (monomer mixture A). In addition, 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 is added to the polymerization reaction system, and the addition-polymerizable component is a single amount. It is also possible to use it as a component of the body mixture and use the non-addition-polymerizable component as a solvent.

  The polymerization temperature for carrying out the polymerization reaction is not particularly limited, but is preferably -20 ° C to 100 ° C, more preferably 10 ° C to 70 ° C. If the polymerization temperature is too low, the polymerization activity may be lowered and productivity may be deteriorated. If the polymerization temperature is too high, the obtained rubber cross-linked product may be inferior in rolling resistance and abrasion resistance. The pressure for carrying out the polymerization reaction may be atmospheric pressure or increased pressure. The polymerization reaction time can be appropriately selected, but is usually 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 solution of sodium hydroxide or an aqueous solution of ammonia to the polymerization reaction system when a desired polymerization conversion rate is obtained.

  The above-mentioned method for producing a hydrocarbon resin may include at least the above-mentioned polymerization step, but may include other steps as necessary.

  As other steps, for example, after the polymerization step, a catalyst residue is removed by adding a polymerization terminator in the polymerization step to inactivate the polymerization catalyst, which is generated when the polymerization catalyst is inactivated. Step, after the polymerization reaction is stopped by the polymerization step, unreacted monomers and solvent are removed, low-molecular weight oligomer components are further removed by steam distillation or the like, and the solid hydrocarbon resin is cooled. The recovering step for obtaining may be mentioned.

  Further, as another step, after the catalyst residue removal step and before the recovery step, the catalyst residue removal mixture after removing the catalyst residue insoluble in the solvent is contacted with the adsorbent to obtain an adsorbent treatment mixture. A treatment step may be provided. The provision of the contact treatment step makes it possible to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

  In addition, you may perform the said other process after the hydrogenation process in the manufacturing method of the hydrocarbon resin hydride mentioned later.

  The adsorbent used in the contact treatment step is not particularly limited, and may be a chemical adsorbent or a physical adsorbent.

  Examples of the chemical adsorbents include zinc adsorbents such as basic zinc carbonate, zinc oxide, zinc sulfate, zinc laurate, zinc stearate, and zinc myristate; zirconium oxide, zirconium hydroxide, zirconium phosphate, and the like. Zirconium-based adsorbents; manganese-based adsorbents such as manganese dioxide; cobalt-based adsorbents such as cobalt chloride; copper-based adsorbents such as copper chloride and copper oxide; amine-based adsorbents such as polyamine compounds.

  Examples of the physical adsorbent include, for example, zeolite-based adsorbents generally referred to in the group of hydrous aluminosilicate minerals such as sodium aluminum silicate, silicon dioxide, magnesium oxide, silica gel, silica / alumina, aluminum silicate, activated alumina, and acid clay. , Activated clay, dawsonite compounds, hydrotalcite compounds, and the like.

  The adsorbents may be used alone or in combination of two or more. When two or more adsorbents are used in combination, two or more chemical adsorbents may be used in combination, two or more physical adsorbents may be used in combination, or one or more chemical adsorbents may be used. The agent and one or more kinds of physical adsorbents may be used in combination, and for example, the physical adsorbent may carry a chemical adsorbent. In particular, from the viewpoint of obtaining a rubber crosslinked product having excellent rolling resistance and abrasion resistance, it is preferable to use a chemical adsorbent among these adsorbents, more preferable to use a zinc adsorbent, and a basic adsorbent. It is particularly preferred to use zinc carbonate.

  In the above contact treatment step, the method of contacting the catalyst residue removal mixture with the adsorbent is not particularly limited. For example, the catalyst residue removal mixture and the adsorbent are allowed to coexist in an appropriately selected container, agitated if necessary, a batch treatment method of contacting them, or the adsorbent is packed in a packed tower in advance, and A continuous treatment method in which the catalyst residue removal mixture is circulated and brought into contact with the above is included.

  The amount of the adsorbent used when the catalyst residue removal mixture and the adsorbent are brought into contact with each other by a batch treatment method is not particularly limited, but is usually 0.1% with respect to 100 parts by mass of the hydrocarbon resin contained in the catalyst residue removal mixture. The amount is 01 to 5.0 parts by mass, preferably 0.03 to 3.0 parts by mass, and more preferably 0.05 to 2.0 parts by mass.

  The temperature at which the catalyst residue removal mixture and the adsorbent are brought into contact with each other is not particularly limited, but is usually 10 to 70 ° C. The treatment time is not particularly limited, but is usually 0.1 to 2 hours.

  When the catalyst residue removal mixture and the adsorbent are contacted by a batch treatment method, the adsorbent can be removed from the catalyst residue removal mixture by filtration or the like, if necessary. Further, when there is no problem in using the hydrocarbon resin and the hydrocarbon resin hydride even if the adsorbent remains, the adsorbent may be subjected to the next step without being removed from the catalyst residue removal mixture.

<Hydrocarbon resin hydride>
The hydrocarbon resin hydride used in the present invention can be obtained by hydrogenating the above-mentioned hydrocarbon resin.

  The hydrogenation rate of the hydrocarbon resin hydride used in the present invention may be in the range of 0.1 to 80%, preferably in the range of 10 to 60%, and more preferably in the range of 20 to 50%. It is within the range. By setting the hydrogenation rate within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced. The hydrogenation rate means the proportion of hydrogenated ones of all non-aromatic carbon-carbon double bonds of the hydrocarbon resin before hydrogenation.

  The carbon-carbon double bond in the hydrocarbon resin may be a non-aromatic carbon-carbon double bond (mainly a main chain carbon-carbon double bond) or an aromatic carbon-carbon double bond. Although there is a heavy bond (carbon-carbon double bond in the aromatic ring), it is preferable that the aromatic carbon-carbon double bond is not hydrogenated as much as possible, and the wholly aromatic carbon-carbon double bond is preferable. Of these, the hydrogenated ratio is preferably 10% or less, more preferably 7% or less, and further preferably 0%.

The hydrogenation rate can be determined from the difference between the non-aromatic carbon-carbon double bonds of the hydrocarbon resin before hydrogenation and the hydrogenated hydrocarbon resin hydride. Here, the non-aromatic carbon-carbon double bond of each resin can be determined by ¹ H-NMR spectrum measurement. ¹ H-NMR spectrum measurement can be carried out using deuterated chloroform as a solvent and JMN-AL series AL400, manufactured by JEOL, as an NMR measuring device.

  The weight average molecular weight (Mw) of the hydrogenated hydrocarbon resin hydride may be in the range of 700 to 6,000, preferably 900 to 4,500, more preferably 1,000. Within the range of up to 4,000. By adjusting the weight average molecular weight (Mw) to the above range, the processability of the obtained rubber composition and the balance of tensile strength, elongation, wet grip property, rolling resistance, and abrasion resistance of the obtained rubber cross-linked product are obtained. Can be increased.

  The number average molecular weight (Mn) of the hydrogenated hydrocarbon resin hydride is preferably in the range of 400 to 3,000, more preferably in the range of 450 to 2,500, and further preferably in the range of 500 to 2,000. Within. By adjusting the number average molecular weight (Mn) within the above range, the balance between the processability of the obtained rubber composition and the tensile strength, elongation, wet grip property, rolling resistance and abrasion resistance of the obtained rubber cross-linked product. Can be increased.

  The Z average molecular weight (Mz) of the hydrogenated hydrocarbon resin hydride is preferably in the range of 1,500 to 20,000, more preferably in the range of 1,800 to 10,000, and further preferably 2, It is in the range of 000 to 8,000. By adjusting the Z-average molecular weight (Mz) within the above range, the processability of the obtained rubber composition and the balance of tensile strength, elongation, wet grip property, rolling resistance, and abrasion resistance of the obtained rubber cross-linked product are obtained. Can be increased.

  In the present invention, the weight average molecular weight (Mw), number average molecular weight (Mn), and Z average molecular weight (Mz) of the hydride of the hydrocarbon resin are obtained as polystyrene-converted values by high performance liquid chromatography measurement. To do.

  Further, the ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight of the hydrocarbon resin hydride is preferably in the range of 1.0 to 4.0, more preferably in the range of 1.2 to 3.5. And more preferably in the range of 1.4 to 3.0. By setting the above ratio within the above range, it is possible to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

  The ratio (Mz / Mw) of the Z average molecular weight to the weight average molecular weight of the hydrocarbon resin hydride is preferably in the range of 1.0 to 4.0, more preferably in the range of 1.2 to 3.5. , And more preferably within the range of 1.4 to 3.0. By setting the above ratio within the above range, it is possible to further enhance the rolling resistance and abrasion resistance of the obtained rubber cross-linked product.

  The softening point of the hydride of the hydrocarbon resin may be in the range of 80 to 150 ° C, preferably in the range of 85 to 145 ° C, and more preferably in the range of 90 to 140 ° C. By setting the softening point within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  In addition, the softening point in the present invention can be measured according to JIS K 2207 for a hydride of a hydrocarbon resin.

  As a method for producing a hydride of a hydrocarbon resin, for example, a method having a hydrogenation step of hydrogenating a hydrocarbon resin can be used.

  In the hydrogenation step, hydrogenation of the hydrocarbon resin can be carried out by bringing the hydrocarbon resin into contact with hydrogen in the presence of a hydrogenation catalyst.

  Examples of hydrogenation catalysts used include those disclosed in JP-B-58-43412, JP-A-60-26024, JP-A-64-24826, JP-A-1-138257, and JP-A-7-41550. What is described can be used and can be a homogeneous or heterogeneous catalyst.

  Examples of the homogeneous catalyst include cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxy titanate / dimethylmagnesium, and the like. A catalyst system comprising a combination of a transition metal compound and an alkali metal compound; a noble metal complex catalyst such as dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, chlorotris (triphenylphosphine) rhodium; and the like. ..

  Examples of heterogeneous catalysts include those in which a hydrogenation catalytic metal such as Ni or Pd is supported on a carrier. Examples of the carrier include silica, alumina, silica-alumina, diatomaceous earth and the like. Above all, a Ni catalyst supported on silica is preferable.

  The hydrogenation reaction may be carried out directly on the hydrocarbon resin, or may be carried out in an organic solvent by dissolving the hydrocarbon resin in an organic solvent. From the viewpoint of easiness of operation, it is preferable to carry out directly on the hydrocarbon resin. The organic solvent used to dissolve the hydrocarbon resin is not particularly limited as long as it is inert to the catalyst, but usually a hydrocarbon solvent is used because it has excellent solubility of the hydrogenated product to be produced. Used.

  Examples of the hydrocarbon solvent include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as n-pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decalin; Among these, cyclic aromatic hydrocarbons and alicyclic hydrocarbons are preferable. These organic solvents can be used alone or in combination of two or more. As the organic solvent, the solvent used for polymerizing the hydrocarbon resin may be used.

  The method of contacting the hydrocarbon resin with hydrogen in the presence of the hydrogenation catalyst is not particularly limited. For example, a hydrocarbon resin and a hydrogenation catalyst are allowed to coexist in an appropriately selected container, stirred if necessary, and a batch treatment method of contacting with hydrogen, or a packed column is filled with the hydrogenation catalyst in advance. Then, a continuous treatment method in which a hydrocarbon resin is circulated and contacted with hydrogen is included.

  The hydrogenation reaction can be performed according to a conventional method. By appropriately adjusting the reaction conditions such as the type of hydrogenation catalyst and the reaction temperature, the hydrogenation ratio of the hydrocarbon resin can be adjusted.

  When a homogeneous catalyst is used as the hydrogenation catalyst, the rate of hydrogenation of the hydrocarbon resin can be increased. A ruthenium homogeneous catalyst is suitable as the homogeneous catalyst. The reaction temperature is preferably 100 to 200 ° C, more preferably 130 to 195 ° C. Further, when a heterogeneous catalyst is used as the hydrogenation catalyst, the rate of hydrogenation of the hydrocarbon resin can be suppressed. As the heterogeneous catalyst, a nickel heterogeneous catalyst is suitable. The reaction temperature is preferably 150 to 300 ° C, more preferably 180 to 260 ° C.

  The absolute hydrogen pressure in the hydrogenation reaction is usually 0.01 to 10 MPa, preferably 0.05 to 6 MPa, and more preferably 0.1 to 5 MPa.

  The lower limit of the amount of hydrogen used is preferably 1 time or more, more preferably 1.2 times or more, and even more preferably 1.8 times or more the theoretically necessary amount of hydrogen for obtaining a resin having a desired hydrogenation rate. The upper limit of the amount of hydrogen used is preferably 20 times or less, more preferably 10 times or less, further preferably 5 times or less, and further preferably 5 times or less of the theoretically necessary amount of hydrogen for obtaining a resin having a desired hydrogenation rate. It is particularly preferably 4 times or less. By setting the amount of hydrogen used in the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  After completion of the hydrogenation reaction, the hydrogenation catalyst is removed from the reaction solution by centrifugation or filtration if necessary. The centrifugation method and filtration method are not particularly limited as long as the used catalyst can be removed. Removal by filtration is preferable because it is simple and efficient. In the case of filtration, pressure filtration or suction filtration may be performed, and from the viewpoint of efficiency, it is preferable to use a filter aid such as diatomaceous earth or perlite. If necessary, a catalyst deactivator such as water or alcohol can be used, or an adsorbent such as activated clay or alumina can be added.

<Diene rubber>
The rubber composition of the present invention contains a diene rubber in addition to the above-mentioned hydrocarbon hydride. The diene rubber is not particularly limited as long as it can be blended with the hydride of the hydrocarbon resin. Examples of such diene rubbers include the diene rubbers described in JP-A-2005-189873. Specifically, natural rubber (NB), isoprene rubber (IR), butadiene rubber ( BR), styrene-butadiene copolymer rubber (SBR), ethylene-propylene-diene terpolymer (EPDM) and the like. Among them, styrene-butadiene copolymer rubber and natural rubber are preferable. .. By using the above-mentioned diene rubber, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced. The diene rubbers may be used alone or in combination of two or more.

  Further, the diene rubber in the present invention is not particularly limited in its molecular weight and microstructure, and may be end-modified with amine, amide, silyl, alkoxysilyl, carboxyl, hydroxyl group or the like, or may be epoxidized. . Further, the diene rubber in the present invention may be hydrogenated, but it is preferable that it is not hydrogenated.

  In the rubber composition of the present invention, the mixing ratio of the diene rubber and the hydrocarbon hydride is 1 to 30 parts by mass of the hydrocarbon hydride based on 100 parts by mass of the diene rubber. It is preferable that 5 to 20 parts by mass is blended. By setting the mixing ratio of the diene rubber and the hydride of the hydrocarbon resin within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  Moreover, the blending amount of the hydrocarbon resin hydride is preferably in the range of 1 to 30% by mass and more preferably in the range of 3 to 25% by mass of the blending amount of silica described below.

<Silica>
The rubber composition of the present invention contains silica in addition to the above-described hydrocarbon resin hydride and diene rubber. Examples of silica include dry method white carbon, wet method white carbon, colloidal silica, and precipitated silica. Among these, wet method white carbon containing hydrous silicic acid as a main component is preferable. Further, a carbon-silica dual phase filler in which silica is supported on the surface of carbon black may be used. These silicas can be used alone or in combination of two or more. The nitrogen adsorption specific surface area (measured by the BET method according to ASTM D3037-81) of silica used is preferably 100 to 400 m ² / g, more preferably 150 to 350 m ² / g. Further, the pH of silica is preferably 5 to 10.

  The amount of silica in the rubber composition of the present invention may be 80 to 200 parts by mass, preferably 85 to 150 parts by mass, and more preferably 90 to 120 parts by mass with respect to 100 parts by mass of the diene rubber. is there. By setting the content of silica within the above range, the rolling resistance and abrasion resistance of the obtained rubber cross-linked product can be further enhanced.

  Further, the rubber composition of the present invention preferably contains a silane coupling agent together with silica. Examples of the silane coupling agent include vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, and 3-octathio-. 1-propyl-triethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, γ-trimethoxysilylpropyldimethylthiocarbamyltetrasulfide, and γ -Trimethoxysilylpropyl benzothiazyl tetrasulfide and the like can be mentioned. These silane coupling agents can be used alone or in combination of two or more kinds. The compounding amount of the silane coupling agent is preferably 0.1 to 30 parts by mass, and more preferably 1 to 15 parts by mass with respect to 100 parts by mass of silica.

  The rubber composition of the present invention may be composed only of a diene rubber, a hydride of a hydrocarbon resin, and silica, but may further contain other components. Other components that may be contained in the rubber composition of the present invention include, for example, fillers other than silica, crosslinking agents, crosslinking accelerators, crosslinking activators, antioxidants, antioxidants, activators, process oils, plasticizers. Agents, lubricants, tackifiers and the like, and these other compounding agents can be added in the required amounts.

  As the filler other than silica that can be blended in the rubber composition of the present invention, those generally used in rubber compositions can be used, and examples thereof include carbon black, clay, diatomaceous earth, talc, barium sulfate, and carbonic acid. Inorganic hollow fillers such as calcium, magnesium carbonate, metal oxides, mica, aluminum hydroxide, various metal powders, wood powders, glass powders, ceramics powders, glass balloons, silica balloons; polystyrene, polyvinylidene fluoride, polyvinylidene fluoride Examples thereof include organic hollow fillers such as polymers.

  Examples of carbon black include furnace black, acetylene black, thermal black, channel black, and graphite. These carbon blacks can be used alone or in combination of two or more.

  The filler may be used alone or in combination of two or more.

  The content of the filler other than silica may be within the range in which the effects of the present invention can be obtained, and for example, can be 120 parts by mass or less with respect to 100 parts by mass of the rubber component.

  The cross-linking agent is not particularly limited, but examples thereof include sulfur, sulfur halides, organic peroxides, quinone dioximes, organic polyvalent amine compounds, and alkylphenol resins having a methylol group. Among these, sulfur is preferably used. The compounding amount of the crosslinking agent is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 4 parts by mass with respect to 100 parts by mass of the rubber component in the rubber composition. Is.

  When sulfur or a sulfur-containing compound is used as the crosslinking agent, it is preferable to use a crosslinking accelerator and a crosslinking activator together. Examples of the crosslinking accelerator include sulfenamide crosslinking accelerators; guanidine crosslinking accelerators; thiourea crosslinking accelerators; thiazole crosslinking accelerators; thiuram crosslinking accelerators; dithiocarbamic acid crosslinking accelerators; xanthogenic acid accelerators. Crosslinking accelerator; and the like. Among these, those containing a sulfenamide crosslinking accelerator are preferable. These crosslinking accelerators may be used alone or in combination of two or more. The amount of the crosslinking accelerator compounded is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 4 parts by mass, relative to 100 parts by mass of the rubber component in the rubber composition. It is a department.

  Examples of the cross-linking activator include higher fatty acids such as stearic acid; zinc oxide; and the like. These crosslinking activators may be used alone or in combination of two or more. The compounding amount of the cross-linking activator is preferably 0.05 to 20 parts by mass, particularly preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the rubber component in the rubber composition.

  If desired, an antiaging agent such as a phenol-based stabilizer, a phosphorus-based stabilizer, or a sulfur-based stabilizer may be added to the rubber composition of the present invention. The amount of the antioxidant added may be appropriately determined depending on the type of the antioxidant.

  Moreover, you may add antioxidant to the rubber composition of this invention as needed. The antioxidant is not particularly limited, but examples thereof include pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-t. -Butyl-4-hydroxyphenyl) propionate, 2,6-di-t-butyl-p-cresol, di-t-butyl-4-methylphenol and other hindered phenolic compounds; such as dilaurylthiopropionate Thiodicarboxylate esters; phosphites such as tris (nonylphenyl) phosphite; and the like. The antioxidants may be used alone or in combination of two or more. The content of the antioxidant is not particularly limited, but is preferably 10 parts by mass or less, and more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the rubber component in the rubber composition.

  Further, the rubber composition of the present invention may contain a resin in addition to the diene rubber and the hydrocarbon resin hydrogen compound described above. By compounding the resin, it is possible to impart tackiness to the rubber composition and to enhance the dispersibility of the filler in the rubber composition. As a result, the obtained rubber cross-linked product can be expected to have improved rolling resistance and abrasion resistance. Further, it is possible to improve the processability of the rubber composition as the same effect as the plasticizer. Examples of the resin include C5 petroleum resin, C5 / C9 petroleum resin, C9 petroleum resin, dicyclopentadiene resin, terpene resin, terpene phenol resin, aromatic modified terpene resin, alkylphenol-acetylene resin, rosin resin. Resin, rosin ester resin, indene resin, C9 resin containing indene, α-methylstyrene / indene copolymer resin, coumarone-indene resin, farnesene resin, polylimonene resin and the like can be mentioned. These resins may be modified or hydrogenated. These resins may be used alone or in combination of two or more. The compounding amount of the resin is preferably 25 parts by mass or less with respect to 100 parts by mass of the rubber component in the rubber composition.

  The method for producing the rubber composition of the present invention may be carried out by kneading each component according to a conventional method. For example, a component excluding heat-labile components such as a crosslinking agent and a crosslinking accelerator, a diene rubber, and a hydrocarbon. After kneading with the resin hydride, a heat-labile component such as a crosslinking agent or a crosslinking accelerator is kneaded with the kneaded product to obtain the desired rubber composition. The kneading temperature at the time of kneading the components excluding heat-labile components, the diene rubber, and the hydride of the hydrocarbon resin is preferably 80 to 200 ° C, more preferably 120 to 180 ° C. The time is preferably 30 seconds to 30 minutes. The kneaded material and the heat-unstable component are kneaded after cooling to preferably 100 ° C or lower, more preferably 80 ° C or lower.

  By using the rubber composition of the present invention, a rubber cross-linked product having excellent rolling resistance and abrasion resistance can be obtained. Taking advantage of such characteristics, the rubber composition of the present invention is preferably used, for example, as a material for tire parts such as treads (cap treads, base treads), carcasses, sidewalls, and bead parts. However, in all kinds of tires such as all-season tires, high-performance tires, and studless tires, treads, carcasses, sidewalls, and bead portions can be preferably used for each part of the tire, for example, for treads of tires, It can be used particularly preferably, and particularly preferably used for a cap tread.

<Rubber cross-linked product>
The rubber crosslinked product of the present invention is obtained by crosslinking the rubber composition of the present invention described above.
The rubber cross-linked product of the present invention is obtained by using the rubber composition of the present invention to perform molding with a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, a roll, etc., and heating. It can be produced by carrying out a cross-linking reaction to fix the shape as a rubber cross-linked product. In this case, the molding may be performed in advance and then crosslinked, or the molding and the crosslinking may be performed simultaneously. The molding temperature is usually 10 to 200 ° C, preferably 25 to 120 ° C. The crosslinking temperature is usually 100 to 200 ° C., preferably 130 to 190 ° C., and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, particularly preferably 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 fully cross-linked to the inside, so secondary heating may be performed to carry out secondary cross-linking.

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

  The thus-obtained rubber cross-linked product of the present invention is obtained by using the above-mentioned rubber composition of the present invention, and therefore has excellent rolling resistance and abrasion resistance.

  The rubber cross-linked product of the present invention takes advantage of its excellent rolling resistance and wear resistance, and is used as a material for tire parts such as treads (cap treads, base treads), carcasses, sidewalls, and bead parts in tires. Among them, in various tires such as all-season tires, high-performance tires, and studless tires, among others, it can be suitably used in each tire portion such as tread, carcass, sidewall, and bead portion. Can be particularly preferably used for the tread, and among them, it is particularly preferably used for the cap tread.

  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 using the above-mentioned rubber composition, that is, one formed using the above-mentioned rubber composition, and usually the rubber cross-linking of the present invention obtained by crosslinking the above-mentioned rubber composition of the present invention. It includes things.

  The tread of the pneumatic tire may be formed using the rubber composition, and other portions may 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 it is preferable that at least the cap tread is included.

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

Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are based on mass unless otherwise specified.
The test methods used in the examples and comparative examples are as follows.

[Hydrogenation rate (%)]
The amount of the non-aromatic carbon-carbon double bond is determined by performing ¹ H-NMR spectrum measurement on the hydrocarbon resin before hydrogenation and the hydrogenated hydrocarbon resin hydride after hydrogenation, and The hydrogenation rate (%) was measured based on the difference in the amount of non-aromatic carbon-carbon double bond. The ¹ H-NMR spectrum measurement was performed using deuterated chloroform as a solvent and JMN-AL series AL400 (manufactured by JEOL) as an NMR measuring device.

[Number average molecular weight, weight average molecular weight, Z average molecular weight, and molecular weight distribution]
A gel permeation chromatography analysis was performed on a hydrocarbon hydride as a sample, and a number average molecular weight (Mn), a weight average molecular weight (Mw), and a Z average molecular weight (Mz) in terms of standard polystyrene were obtained, and the molecular weight was calculated. The distribution is shown by the ratio of Mw / Mn and the ratio of Mz / Mw. In addition, 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, using tetrahydrofuran as a solvent. , 40 ° C., and a flow rate of 1.0 mL / min.

[Softening point (℃)]
With respect to the hydrocarbon hydride as a sample, the softening point was measured according to JIS K 2207.

[Moonie viscosity (ML1 + 4)]
The rubber composition as a sample was measured under the following conditions in accordance with JIS K 6300-1: 2001. This characteristic is shown by an index with the reference sample (Comparative Example 1 described later) as 100.
・ Test temperature: 100 ℃
・ Type of rotor: L type ・ Test machine: Shimadzu Mooney Viscometer SMV-300J made by Shimadzu Corporation

[Tensile strength (MPa) and elongation (%)]
Tensile strength (tensile stress (MPa)) and elongation (elongation (%)) of the test piece of the rubber cross-linked product as a sample were measured under the following conditions according to JIS K 6251: 2010. These characteristics are shown by indices with the reference sample (Comparative Example 1 described later) as 100.
・ Test piece preparation method: punching after forming a sheet by press-crosslinking ・ Test piece shape: dumbbell No. 3 shape ・ Test piece collection direction: parallel to grain ・ Number of test pieces: 3
・ Measurement temperature: 23 ℃
・ Test speed: 500 mm / min
・ Use tester: TENSOMETER 10k manufactured by ALPHA TECHNOLOGIES
・ Tester capacity: Load cell type 1kN

[Loss tangent tan δ]
Regarding a test piece of a rubber cross-linked product as a sample, the loss tangent tan δ at 0 ° C. and 60 ° C. was measured under the following measurement conditions under a dynamic strain of 0.5% and 10 Hz, according to JIS K 7244-4. .. This characteristic is shown by an index with the reference sample (Comparative Example 1 described later) as 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 elastic modulus E "
: Loss tangent tan δ
-Sample preparation method: punching from sheet-Test piece shape: length 50 mm x width 2 mm x thickness 2 mm
・ Number of test pieces: 1
・ Clamp distance: 20 mm

[Abrasion resistance]
Using a FPS abrasion tester manufactured by Ueshima Seisakusho, a sheet-shaped rubber cross-linked product test piece as a sample was measured at a load of 1 kgf and a slip ratio of 15%. This property was calculated by an index with the measured value of the sample of Comparative Example 1 as 100. The larger this index is, the better the abrasion resistance can be evaluated.

[Production Example 1]
A polymerization reactor was charged with a mixture of 56.1 parts of cyclopentane and 15.5 parts of cyclopentene, the temperature was raised to 70 ° C., and then 0.75 part of aluminum chloride was added (mixture M ₁ ). Subsequently, 1,3-pentadiene 46.7 parts, isobutylene 18.4 parts, diisobutylene 0.1 part, dicyclopentadiene 0.1 part, C4-C6 unsaturated hydrocarbon 0.2 part, C4-C6 saturated carbonization. A mixture a ₁ consisting of 7.2 parts of hydrogen and 19.0 parts of styrene was continuously added to a polymerization reactor containing the mixture M ₁ obtained above while maintaining the temperature at 70 ° C. for 60 minutes. Polymerization was carried out while adding. Then, the polymerization reaction was stopped by adding an aqueous sodium hydroxide solution to the polymerization reactor. The types and amounts of the components in the polymerization reactor during the polymerization reaction are summarized in Table 1. The precipitate generated by termination of the polymerization was removed by filtration to obtain a polymer solution containing the hydrocarbon resin before hydrogenation, unreacted monomers and the like. Next, the polymer solution was charged into a distillation kettle and heated under a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers to obtain a hydrocarbon resin before hydrogenation.

  Then, the hydrocarbon resin before hydrogenation obtained above was supplied to a multi-tube heat exchange type hydrogenation reaction device to hydrogenate the hydrocarbon resin. The hydrogenation reaction uses a nickel silica catalyst (N108F manufactured by JGC Catalysts & Chemicals Co., Ltd.) as a hydrogenation catalyst, hydrogen pressure 1.2 MPa, reaction temperature 220 ° C., residence time in reaction tube 30 minutes, and desired hydrogenation rate It was carried out under the condition of 1.7 times the amount of hydrogen required to obtain a hydride of a hydrocarbon resin.

  The obtained polymer solution containing hydrocarbon hydride was charged into a distillation pot and heated in a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers. Next, at 200 ° C. or higher, a low molecular weight oligomer component was distilled off while blowing saturated steam to obtain a hydrocarbon resin hydride of Production Example 1. The hydrogenation rate, number average molecular weight, weight average molecular weight, Z average molecular weight, molecular weight distribution, and softening point of the obtained hydrocarbon resin hydride of Production Example 1 were measured. The results of these measurements are summarized in Table 1 below.

[Production Examples 2 to 7]
A hydrocarbon resin hydride 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 and the hydrogenation conditions were changed as shown in Table 1 below. Regarding the obtained hydrocarbon resin hydrides of Production Examples 2 to 7, hydrogenation rate, number average molecular weight, weight average molecular weight, Z average molecular weight, molecular weight distribution, and The softening point was measured. The results of these measurements are summarized in Table 1 below.

[Example 1]
Emulsion-polymerized styrene-butadiene rubber (E-SBR) (trade name "Nipol 1739", manufactured by Nippon Zeon Co., Ltd., bound styrene content: 40%, vinyl bond content in butadiene unit: 13) 0.5 mol%, weight average molecular weight: 690,000, molecular weight distribution (Mw / Mn): 3.98, glass transition temperature (Tg): −35 ° C., 37.5 parts of extender oil to 100 parts of rubber component. 96.3 parts (rubber component content: 70 parts, extender oil content: 26.3 parts) and solution-polymerized styrene butadiene rubber (S-SBR) (trade name "Nipol NS 616", Japan Zeon, Mooney viscosity (ML1 + 4,100 ° C.): 62) 15 parts, and natural rubber (NR) (SIR20) 15 parts were masticated for 30 seconds, and then silica (manufactured by Rhodia, Product name "Zeosil 1165MP") 60 parts, carbon black (manufactured by Cabot Japan, product name "N234") 20 parts, silane coupling agent: bis [3- (triethoxysilyl) propyl] tetrasulfide (manufactured by Tegusa, product name) "Si69") 9 parts, and 10 parts of the hydrocarbon resin hydride obtained in Production Example 1 were added, and after kneading for 90 seconds, 40 parts of silica (manufactured by Rhodia, trade name "Zeosil 1165MP"), 3 parts of zinc oxide. , 2 parts of stearic acid, and 2 parts of anti-aging agent: N-phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Nocrac 6C"). Add, knead for 90 seconds, and then add 15 parts of process oil (Nippon Oil Co., Ltd., trade name "Alomax T-DAE"). It was Then, the mixture was kneaded (primary kneading) at 145 to 155 ° C. for 60 seconds or more with 90 ° C. as the starting temperature, and then the kneaded product was discharged from the mixer.

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

  Then, with two rolls at 50 ° C., 1.7 parts of sulfur and a crosslinking accelerator: N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS, trade name “Noccer CZ-G”) were added to the obtained kneaded product. , Ouchi Shinko Chemical Industry Co., Ltd.) 1.8 parts, and diphenylguanidine (DPG trade name "Nocceller D", Ouchi Shinko Chemical Industry Co., Ltd.) 1.7 parts were added and these were kneaded (crosslinking agent kneading). After that, the sheet-shaped rubber composition was taken out.

  The kneading conditions of the primary kneading, the secondary kneading, and the kneading of the cross-linking agent were the following conditions.

(Kneading conditions for primary kneading and secondary kneading)
・ Testing machine: Toyo Seiki Seisakusho Labo Plastomill Banbury type mixer B-600
・ Filling ratio: 70 to 75 vol%
・ Rotor speed: 50 rpm
・ Test start set temperature: 90 ℃

(Kneading conditions for kneading cross-linking agent)
・ Testing machine: Electric heating type high temperature roll machine manufactured by Ikeda Machinery Co., Ltd. ・ Roll size: 6φ × 16
・ Front roll speed: 24 rpm
・ Front and rear roll rotation ratio: 1: 1.22
・ Roll temperature: 50 ± 5 ℃
・ Number of times of turning back: 2 times each on left and right ・ Rounding width: Roll interval of about 0.8 mm
・ Number of rounds: 5 times

[Examples 2 to 4 and Comparative Examples 1 to 3]
As shown in Table 2 below, a rubber composition was obtained in the same manner as in Example 1 except that the hydrocarbon resin hydrides obtained in Production Examples 2 to 7 were used in place of the hydrocarbon resin hydride obtained in Production Example 1. I got a thing.

[Evaluation]
The rubber compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were press-crosslinked with a press pressure of about 8 MPa and a press temperature of 160 ° C. for 40 minutes, and then further aged in a thermostatic chamber at 23 ° C. overnight, and then 150 mm. A test piece of a rubber cross-linked product having a size of 150 mm and a thickness of 2 mm was prepared.

  Regarding the rubber compositions and rubber cross-linked products obtained in Examples 1 to 4 and Comparative Examples 1 to 3, Mooney viscosity of the rubber composition, tensile strength (MPa), elongation (%), loss tangent tan δ of the rubber cross-linked product. , And abrasion resistance were measured. The results are shown in Table 2 below.

  As shown in Tables 1 and 2, a hydrocarbon resin hydride obtained by hydrogenating a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit, which has a hydrogenation rate of 0.1. Is 80%, the weight average molecular weight (Mw) is 700 to 6,000, and the softening point is 80 to 150 ° C., a rubber composition containing a hydride of a hydrocarbon resin, a diene rubber, and silica, The workability was excellent, and the obtained rubber cross-linked product was excellent in tensile strength, elongation, and wet grip property, and particularly excellent in rolling resistance and abrasion resistance (Examples 1 to 4).

On the other hand, a rubber crosslinked product made of a rubber composition containing an unhydrogenated hydrocarbon resin instead of the hydrocarbon hydride was inferior in rolling resistance and abrasion resistance (Comparative Examples 1, 2). ).
Further, a rubber cross-linked product made of a rubber composition containing a hydrogenated hydrocarbon resin having a hydrogenation rate of more than 80% was inferior in rolling resistance (Comparative Example 3). Regarding the abrasion resistance, a rubber cross-linked product (Comparative Example 3) made of a rubber composition containing a hydrogenated hydrocarbon resin having a hydrogenation rate of more than 80% was used to hydrogenate a hydrocarbon resin having the same monomer composition. It was inferior to the rubber cross-linked product (Example 4) composed of the hydrogenated hydrocarbon resin.

Claims (4)

A rubber composition containing a diene rubber, a hydrocarbon resin hydride, and silica,
The content of the hydrocarbon hydride is 1 to 30 parts by mass with respect to 100 parts by mass of the diene rubber,
The content of the silica is 80 to 200 parts by mass with respect to 100 parts by mass of the diene rubber,
The hydrocarbon resin hydride is
What is obtained by hydrogenating a hydrocarbon resin containing an aliphatic monomer unit and an aromatic monomer unit,
The hydrogenation rate is in the range of 0.1 to 80%,
The weight average molecular weight (Mw) is in the range of 700 to 6,000,
A rubber composition having a softening point in the range of 80 to 150 ° C. The hydrocarbon resin is
1,3-pentadiene monomer unit 10 to 60% by mass,
1 to 30% by mass of 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,
Alicyclic diolefin monomer unit 0 to 10 mass%, and the aromatic monomer unit 0.1 to 50 mass%,
The hydrocarbon resin hydride is
The number average molecular weight (Mn) is in the range of 400 to 3,000,
Z average molecular weight (Mz) is in the range of 1,500 to 20,000,
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 4.0.   The rubber composition according to claim 1, wherein the aromatic monomer contains at least one selected from the group consisting of a styrene compound, an indene compound, and a C9 fraction.   A pneumatic tire using the rubber composition according to any one of claims 1 to 3 for a tread.