JP2021091830A - Rubber composition, method for producing the same and tire - Google Patents

Abstract

To provide a rubber composition that has an increased content of metal oxide such as zinc oxide to shorten the vulcanization reaction time, and achieves improved reversion of the vulcanized rubber composition.SOLUTION: A rubber composition contains a rubber component, a eutectic compound, and metal oxide of more than 4 pts.mass relative to the rubber component 100 pts.mass. There are also provided a method for producing the rubber composition, and a tire including the vulcanized rubber composition.SELECTED DRAWING: None

Description

The present invention relates to a rubber composition containing a rubber component, a eutectic compound, and a metal oxide.

Metal oxides, especially zinc oxide, are commonly used for sulfur vulcanization of rubber, typically in combination with stearic acid.
Zinc species and / or zinc oxide are believed to act as activators for sulfur vulcanization.
Zinc oxide and stearic acid are also thought to form zinc species in situ and, in combination with zinc oxide, affect the speed and quality of the sulfur vulcanization process.
On the other hand, if the blending amount of a metal oxide such as zinc oxide is reduced, the vulcanization density of the rubber composition after vulcanization decreases, so that the tensile stress at each elongation and the maximum vulcanization curve in the vulcanization tester are maximum. There was a problem that the torque Fmax decreased. From these points, in the conventional rubber composition, it is preferable to add 2 parts by mass or more of a metal oxide such as zinc oxide to 100 parts by mass of the rubber component.

Further, in order to adjust the vulcanization rate of the sulfur-containing rubber composition, an attempt has been made to use a new vulcanization accelerator, and a rubber composition containing a quaternary ammonium salt has been proposed (Patent Document 1).

JP-A-2019-44126

An object of the present invention is to obtain a rubber composition having a further shortened vulcanization reaction time and improved vulcanization returnability as compared with the conventional one, and as a result, a tire having excellent high temperature durability.

The present inventor further enhances the dispersibility of the metal oxide compounded in a large amount by further compounding the eutectic compound in the rubber composition containing a large amount of the metal oxide, further shortens the vulcanization reaction time, and adds. It has been found that a rubber composition having improved vulcanization returnability can be obtained, and as a result, a tire having excellent high temperature durability can be obtained.
That is, the present invention
[1] A rubber composition containing a rubber component, a eutectic compound, and a metal oxide exceeding 4 parts by mass with respect to 100 parts by mass of the rubber component.
[2] The rubber composition according to the above [1], wherein the metal oxide is an oxide of zinc.
[3] The rubber composition according to the above [1], wherein the eutectic compound is a mixed product of an onium salt and a hydrogen bond donor.
[4] The rubber composition according to the above [3], wherein the onium salt is at least one selected from the group consisting of an ammonium salt, a sulfonium salt and a phosphonium salt.
[5] The rubber composition according to the above [3], wherein the hydrogen bond donor contains a structure derived from at least one selected from a urea derivative and an alkylene glycol in the molecule.
[6] The rubber composition according to the above [3] or [4], wherein the onium salt is an ammonium salt.
[7] The rubber composition according to the above [6], wherein the ammonium salt is a quaternary ammonium salt.
[8] The rubber composition according to the above [7], wherein the quaternary ammonium salt is choline chloride.
[9] The rubber composition according to any one of [1] to [8], which is used for run-flat tires.
[10] The rubber composition according to any one of [11] [1] to [9], which comprises the rubber composition after vulcanization of the rubber composition according to any one of [1] to [8]. A run-flat tire containing the vulcanized rubber composition of the above, and a component containing [12] a rubber component, an organic salt liquid at room temperature, and a metal oxide exceeding 4 parts by mass with respect to 100 parts by mass of the rubber component. Is a method for producing a rubber composition, which comprises a step of mixing.

According to the present invention, in a rubber composition containing a large amount of a metal oxide such as zinc oxide, a rubber composition having a short vulcanization reaction time and improved vulcanization returnability is obtained, and as a result, high temperature durability is obtained. Excellent tires can be obtained.

Hereinafter, the rubber composition according to the embodiment of the present invention will be described in detail.
[Rubber composition]
In the present invention, the rubber composition indicates an unvulcanized rubber composition before vulcanization (sometimes abbreviated as a vulcanizable rubber composition), except when there is a limitation of "after vulcanization". ..
The rubber composition of the present invention contains a rubber component, a eutectic compound, and a metal oxide exceeding 4 parts by mass with respect to 100 parts by mass of the rubber component.
In addition to the above compounding materials, optionally, a filler, a sulfur-containing vulcanizer (including sulfur), stearic acid, and an organometallic compound (eg, an organometallic salt) are included. In addition, softeners such as process oils (processing oils) and / or bulking oils, resins, waxes, vulcanization accelerators, scorch inhibitors, antioxidants, antioxidants, and others known in the art. Other optional ingredients such as rubber compounding additives may also be included. However, any other component, not limited to these, may be included.

[Eutectic compound]
The eutectic compound according to the present invention is preferably a mixed product of at least one onium salt selected from the group consisting of ammonium salt, sulfonium salt and phosphonium salt and a hydrogen bond donor. This eutectic compound may be liquid, and when it is liquid, it is also called a eutectic solvent or a deep eutectic solvent (DES), and is liquid at room temperature (23 ° C.).
In one or more embodiments, the eutectic compounds have a lower melting point than each compound combined. As a result, the eutectic compound comprises a composition formed by combining two or more compounds.
Without wishing to be bound by any particular theory, it is believed that the eutectic components react or interact in other ways to form a complex.
Thus, any reference to a eutectic compound, or eutectic combination, eutectic pair, or eutectic complex comprises a combination and reaction product or complex between the combined components that produces a lower melting point than the respective component. .. For example, in one or more embodiments, a useful eutectic composition can be defined by Formula I.

Cat ⁺ X ^- zY ... (I)
Here, Cat ⁺ is a cation, X ⁻ is a counter anion (counter anion, eg Lewis base), and z is the number of Y molecules that interact with the counter anion (eg Lewis base).
Lewis base. For example, Cat ⁺ can include ammonium, phosphonium, or sulfonium cations.
As X ⁻ , for example, a halide ion can be contained.
In one or more embodiments, z is the number to achieve a deep eutectic solvent, or in other embodiments a number to achieve a complex having a melting point lower than each eutectic component.

In one or more embodiments, the useful eutectic compound comprises a combination of acid and base, and the acid and base may comprise Lewis acid and base, or Bronsted acid and base.
In one or more embodiments, a useful eutectic compound is a combination of a tetraammonium salt and a metal halide (called a type I eutectic compound), a tetraammonium salt and a metal halide hydrate (type II). A combination with a tetraammonium salt (called a eutectic compound), a combination of a tetraammonium salt and a hydrogen bond donor (called a type III eutectic compound), or a metal halide hydrate and a hydrogen bond donor (type IV eutectic compound). Includes a combination with).

(Onium salt)
The onium salt is preferably at least one selected from the group consisting of ammonium salts, sulfonium salts and phosphonium salts. That is, as the onium salt, a similar combination in which a sulfonium salt or a phosphonium salt is used instead of the ammonium salt can also be used.
At least one onium salt is mixed with the hydrogen bond donor to give a mixed product, a eutectic compound.
In the present invention, the ammonium salt is preferable among the onium salts, and the quaternary ammonium salt is particularly preferable among the ammonium salts.

(Quaternary ammonium salt)
In one or more embodiments, the quaternary ammonium salt is solid at 20 ° C.
In these or other embodiments, the metal halide and the hydrogen bond donor are solid at 20 ° C.

In one or more embodiments, a useful quaternary ammonium salt, which may also be referred to as an ammonium compound, can be defined by Formula II.

_{(R 1) (R 2)} (R 3) (R 4) -N + -Φ - ····· (II)
Here, each R ₁ , R ₂ , R ₃ , and R ₄ are individually hydrogen or monovalent organic groups, or, instead, R ₁ , R ₂ , R ₃ , and R ₄ are two. It combines to form a divalent organic group, where Φ is an anion.
In one or more embodiments, R _{1, R} 2, _{R 3,} and at least one of R _4, at least two in other embodiments, and at least three and in other embodiments is not hydrogen.

In one or more embodiments, a counter anion (e.g. [Phi ^-) is a halide (X-), nitrate (NO ₃ -), tetrafluoroborate (BF ₄ -), perchlorate (ClO ₄ -), Triflate (SO ₃ CF _3- ), trifluoroacetate (COOCF _3- ) are selected from the group.
In one or more embodiments, Φ ⁻ is a halide ion and in certain embodiments a chloride ion.

In one or more embodiments, the monovalent organic group comprises a hydrocarbyl group and the divalent organic group comprises a hydrocarbylene group.
In one or more embodiments, the monovalent and divalent organic groups include heteroatoms, including, but not limited to, oxygen and nitrogen and / or halogen atoms.
Thus, the monovalent organic group may include an alkoxy group, a siloxy group, an ether group, and an ester group, as well as a carbonyl or acetyl substituent.
In one or more embodiments, the hydrocarbyl and hydrocarbylene groups are from 1 (or a suitable minimum number) to about 18 carbon atoms, in other embodiments from 1 to about 12 carbon atoms, and others. In the embodiment, it contains 1 to about 6 carbon atoms. The hydrocarbyl group and the hydrocarbylene group may be branched, cyclic, or linear. Typical types of hydrocarbyl groups include alkyl groups, cycloalkyl groups, aryl groups and alkylaryl groups. Typical types of hydrocarbylene groups include alkylene groups, cycloalkylene groups, arylene groups, and alkylarylene groups.
In certain embodiments, the hydrocarbyl group is selected from the group consisting of a methyl group, an ethyl group, an octadecyl group, a phenyl group, and a benzyl group.
In certain embodiments, the hydrocarbyl group is a methyl group and the hydrocarbylene group is an ethylene or propylene group.

Useful types of ammonium compounds include secondary ammonium compounds, tertiary ammonium compounds, and quaternary ammonium compounds. In these or other embodiments, the ammonium compounds include, but are not limited to, ammonium halides such as ammonium chloride.
In certain embodiments, the ammonium compound is quaternary ammonium chloride.
In certain _{embodiments, R 1, R 2, R} 3, and _{R 4} is hydrogen, ammonium compound is ammonium chloride.
In one or more embodiments, the ammonium compounds are asymmetric.

In one or more embodiments, the ammonium compound comprises an alkoxy group and can be defined by formula III.

_{(R 1) (R 2)} (R 3) -N + - (R 4 -OH) Φ - ····· (III)
Here, each R ₁ , R ₂ , and R ₃ are individually hydrogen or monovalent organic groups, or, as an alternative _{, two of R 1} , R 2, and R ₃ are combined to form a divalent. Forming an organic group, R ₄ is a divalent organic group and Φ ⁻ is a counter anion.
At least one in one or more embodiments, at least two in other embodiments, and at least three of R ₁ , R ₂ , and R ₃ in other embodiments are not hydrogen.

Examples of ammonium compounds defined by formula III include N-ethyl-2-hydroxy-N, N-dimethylethaneaminium chloride, 2-hydroxy-N, N, N-trimethylethaneaminium chloride (as choline chloride). Also known), and N-benzyl-2-hydroxy-N, N-dimethylethaneaminium chloride.

In one or more embodiments, the ammonium compound comprises a halogen-containing substituent and can be defined by Formula IV:

Φ ^― − (R ₁ ) (R ₂ ) (R ₃ ) −N ⁺ −R ₄ X ・ ・ ・ ・ ・ (IV)
Here, R ₁ , R ₂ , and R ₃ are hydrogen or monovalent organic groups, respectively, or, instead, R ₁ , R ₂ , and R ₃ are combined to form a divalent organic group. When forming a group, R ₄ is a divalent organic group, X is a halogen atom, and Φ ⁻ is a counter anion.
At least one in one or more embodiments, at least two in other embodiments, and at least three of R ₁ , R ₂ , and R ₃ in other embodiments are not hydrogen.
In one or more embodiments, X is chlorine.

Examples of ammonium compounds defined by formula IV are 2-chloro-N, N, N-trimethylethylaminium (also called chlorocholine chloride), and 2- (chlorocarbonyloxy) -N, N, N-trimethyl. Includes, but is not limited to, ethylammonium chloride.

Specific examples of the quaternary ammonium salt in the present invention include choline chloride, acetylcholine chloride, lauroyl choline chloride, β-methylcholine chloride, carbamyl choline chloride, choline metachloride, trimethylacetohydrazidoammonium chloride, benzoylcholine chloride, and the above. N-Ethyl-2-hydroxy-N, N-dimethylethaneaminium chloride, N-benzyl-2-hydroxy-N, N-dimethylethaneaminium chloride, and tetramethylammonium chloride, among others, chloride. Choline, acetylcholine chloride and lauroyl choline chloride are preferred.

[Hydrogen bond donor]
In one or more embodiments, the hydrogen bond donor (HBD compound) includes, but is not limited to, amines, amides, carboxylic acids, and alcohols.
In one or more embodiments, the hydrogen bond donor comprises a hydrocarbon chain component. The hydrocarbon chain component can include a carbon chain length containing at least two carbon atoms, at least three in other embodiments, and at least five carbon atoms in other embodiments. Also, in other embodiments, the hydrocarbon chain component has a carbon chain length of less than 30, in other embodiments less than 20, and in other embodiments less than 10 carbon atoms.

(Amine)
In one or more embodiments, useful amines include compounds defined by formula a.

R _1- (CH ₂ ) _x- R ₂ ... (a)
Here, R ₁ and R ₂ are -NH ₂ , -NHR ₃ , or NR ₃ R ₄ , and x is an integer of at least 2.
In one or more embodiments, x is 2 to about 10, in other embodiments about 2 to about 8, and in other embodiments about 2 to about 6. R ₁ , R ₂ , R ₃ and R ₄ are the same as the definitions in Equation IV, respectively.

Specific examples of useful amines include aliphatic amines, ethylenediamine, diethylenetriamine, aminoethylpiperazine, triethylenetetramine, tris (2-aminoethyl) amine, N, N'-bis- (2-aminoethyl) piperazin, piperazin ethylenediamine. , And tetraethylenepentamine, propyleneamine, aniline, substituted aniline, and combinations thereof.

(Amid)
In one or more embodiments, useful amides include compounds defined by formula b.

R-CO-NH ₂ ... (b)
In the formula, R is H, NH ₂ , CH ₃ or CF ₃ .

Specific examples of useful amides include, but are not limited to, urea, 1-methylurea, 1,1-dimethylurea, 1,3-dimethylurea, thiourea, benzamide, acetamide, and combinations thereof. ..

(carboxylic acid)
In one or more embodiments, useful carboxylic acids include monofunctional, bifunctional, and trifunctional organic acids. These organic acids can include alkyl acids, aryl acids, and mixed alkyl-aryl acids.

Specific examples of useful monofunctional carboxylic acids include, but are not limited to, aliphatic acids, phenylpropionic acids, phenylacetic acid, benzoic acid, and combinations thereof.
Specific examples of the bifunctional carboxylic acid include, but are not limited to, oxalic acid, malonic acid, adipic acid, succinic acid, and combinations thereof.
Specific examples of trifunctional carboxylic acids include citric acid, tricarbaryl acid, and combinations thereof.

(alcohol)
Types of alcohols include, but are not limited to, monools, diols, and triols. Specific examples of monools include aliphatic alcohols, phenols, substituted phenols, and mixtures thereof. Specific examples of diols include ethylene glycol, propylene glycol, resorcinol, substituted resorcinol, and mixtures thereof. Specific examples of triol include, but are not limited to, glycerol, benzenetriol, and mixtures thereof.

The hydrogen bond donor preferably contains a structure derived from at least one selected from urea derivatives and alkylene glycols in the molecule.
Preferable specific examples of the hydrogen bond donor include urea derivatives and alkylene glycols.

(Urea derivative)
Urea derivatives include compounds defined by formula c.
R ₂ N-CX-NR ₂ ... (c)
In the formula, R is an H or monovalent organic group, and X is O (oxygen atom) or S (sulfur atom). As the monovalent organic group, a monovalent hydrocarbon group which may have a hetero atom is preferable.
Specific examples of the urea derivative include, but are not limited to, urea, 1-methylurea, 1,1-dimethylurea, 1,3-dimethylurea, thiourea, and combinations thereof.

(Alkylene glycol)
Examples of hydrogen bond donors include alkylene glycols as well as urea derivatives. As the alkylene glycol, ethylene glycol having 2 carbon atoms, propylene glycol having 3 carbon atoms, and butylene glycol having 4 carbon atoms are preferable, and ethylene glycol is particularly preferable.

(Metal halide, metal halide hydrate)
Examples of the type of metal halide used in the eutectic compound according to the present invention include, but are not limited to, chlorides, bromides, iodides and fluorides.
In one or more embodiments, these metal halides include, but are not limited to, transition metal halides.
Moreover, the metal halide hydrate corresponding to the above can also be easily used.

Specific examples of useful metal halides include aluminum chloride, aluminum bromide, aluminum iodide, zinc chloride, zinc bromide, zinc iodide, tin chloride, tin bromide, tin iodide, iron chloride, iron bromide. , Iron iodide, and combinations thereof, but is not limited thereto.
Moreover, the metal halide hydrate corresponding to the above can also be easily used.
For example, aluminum chloride hexahydrate and copper chloride dihydrate correspond to the above-mentioned halide hydrates.

(Production of eutectic compounds)
In the present invention, an appropriate eutectic member can be selected at an appropriate molar ratio in order to provide a eutectic composition of a desired eutectic compound.
Usually, the molar ratio of a pair of first compounds (eg, Lewis bases) to a pair of second compounds (eg, Lewis acids) varies based on the selected compound.
The melting point of the eutectic compound exists between the melting points of the two constituents, and the melting point of the eutectic compound is determined according to the molar ratio.
However, the molar ratio of the first compound to the second compound nevertheless changes to result in suppression of the melting point of the eutectic solvent with respect to the individual melting points of the first and second compounds, which are not the minimum melting points. Can be made to.
Therefore, embodiments of one or more embodiments of the present invention include forming a eutectic solvent at a molar ratio outside the eutectic point.

In the eutectic compound according to the present invention, in one or more embodiments, the molar ratio of the eutectic pair compound and the pair of the first compound to the second compound is less than 130 ° C., and in other embodiments 110. Melting point below ° C., below 100 ° C. in other embodiments, below 80 ° C. in other embodiments, below 60 ° C. in other embodiments, below 40 ° C. in other embodiments, and below 30 ° C. in other embodiments. Is selected to produce a mixture with.
In these or other embodiments, the compound of the eutectic pair, and the molar ratio of the compounds to a melting point greater than 0 ° C., in other embodiments greater than 10 ° C., greater than 20 ° C. in other embodiments greater than 30 ° C. In other embodiments above 40 ° C., the embodiment is selected to produce a mixture.

The eutectic compound according to the present invention is a compound having a eutectic pair in one or more embodiments, and the molar ratio of the first compound pair to the second compound has the ability or ability to dissolve a desired metal compound. Selected to produce a crystalline solvent, which can be referred to as solubility or dissolving power.
This solubility can be quantified based on the mass of the metal compound dissolved in a given mass of eutectic solvent over a period of time at a particular temperature and pressure when a saturated solution is prepared.
In one or more embodiments, the eutectic solvent of the invention exceeds 100 ppm over 24 hours at 50 ° C. under atmospheric pressure, in other embodiments greater than 500 ppm, in other embodiments 1000 ppm. Exceeded, in other embodiments greater than 1200 ppm, in other embodiments greater than 1400 ppm, and in other embodiments greater than 1600 ppm soluble in zinc oxide is selected, where ppm is the mass solute. Measured on the basis of mass solvent.

In one or more embodiments, the eutectic compound combines the first compound with the second compound in an appropriate molar ratio to provide a solvent composition (ie, a liquid composition at a desired temperature). Formed by.
The eutectic mixture can be mechanically agitated by using various techniques including, but not limited to, solid state mixing or blending techniques.
Generally speaking, the eutectic mixture for producing the eutectic compound is mixed or otherwise stirred until a visually uniform liquid is formed.
Also, the eutectic mixture may be formed at a high temperature. For example, the eutectic compound can be formed by heating the eutectic mixture to a temperature above 50 ° C., above 70 ° C. in other embodiments, and above 90 ° C. in other embodiments.
Mixing can be continued during heating of the eutectic mixture. Once the desired mixture is formed, the eutectic solvent can be cooled to room temperature.
In one or more embodiments, the eutectic mixture can be cooled at a controlled rate, such as a rate of less than 1 ° C./min.

In one or more embodiments, useful eutectic compounds are commercially available. For example, deep eutectic solvents are commercially available from Scionix under the trade name Ionic Liquids.
Useful eutectic compounds are also commonly known as described in the US Patent Gazette below.
Nos. 2004/0997755 A1 and 2011/0707633 A1 are incorporated herein by reference.

In the eutectic compound according to the present invention, the combination of the quaternary ammonium salt and the hydrogen bond donor is preferable, and the molar ratio (quaternary ammonium salt / hydrogen bond donor) is 1/100 to 10/1. Preferably, 1/10 to 5/1 is more preferable, 1/5 to 2/1 is further preferable, and 1/5 to 1/1 is particularly preferable. This is because eutectic compounds are efficiently produced when the molar ratio (quaternary ammonium salt / hydrogen bond donor) is in the range of 1/100 to 10/1. In particular, when the molar ratio is 1/100 or more, the melting point is preferably lower than that of the quaternary ammonium salt, and when it is 10/1 or less, the melting point is lower than that of the hydrogen bond donor, which is preferable. In this case, the temperature of the eutectic mixture of the quaternary ammonium salt and the hydrogen bond donor is set so that the eutectic solvent is generated in the range of 50 to 150 ° C., preferably 70 to 120 ° C.

(Rubber component)
In one or more embodiments, the rubber component comprises a polymer in which a vulcanizable rubber, which may also be called rubber or a vulcanizable elastomer, can be vulcanized to form a composition having rubbery or elastomeric properties. be able to.
Examples of these rubber components include natural rubber and synthetic rubber. Synthetic rubbers are typically conjugated diene monomer polymer rubbers, copolymer rubbers of conjugated diene monomers with other monomers such as vinyl-substituted aromatic monomers, or ethylene and one or more α-olefins and optionally. Examples thereof include a copolymer rubber with one or more kinds of diene monomers.

Specific examples of the rubber component include natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene ternary copolymer rubber, and isoprene-butadiene. Copolymer rubber, butyl halide rubber, ethylene-propylene-diene ternary copolymer rubber (EPDM), isobutylene-isoprene copolymer rubber, ethylene-propylene copolymer rubber (EPM), butyl halide rubber, butyl rubber, acrylic It is preferable to contain at least one selected from the group consisting of rubber, fluororubber, chlorosulfonated polyethylene, urethane rubber, and neoprene rubber. These rubber components can have a myriad of macromolecular structures, including linear, branched, and star structures. These rubber components may also contain one or more functional units, typically containing heteroatoms.
In the present invention, the rubber components are natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene ternary copolymer rubber, isoprene-. It is more preferable to contain at least one selected from the group consisting of butadiene copolymer rubber, butyl halide rubber and ethylene-propylene-diene ternary copolymer rubber (EPDM), and the rubber component is natural rubber or synthetic poly. At least selected from the group consisting of isoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene ternary copolymer rubber, and isoprene-butadiene copolymer rubber. It is particularly preferable to include one type.

[Metal oxide]
As suggested above, the vulcanizable rubber composition of the present invention contains a metal oxide as a metal activator.
In one or more embodiments, the metal oxide is an activator (ie, assists in vulcanization or curing of rubber).
In other embodiments, zinc oxide, i.e. zinc oxide, is preferred as the metal oxide serving as the metal activator.
In certain embodiments, the metal oxide is zinc organic acid formed in situ by the reaction or interaction between zinc oxide and an organic acid (eg, stearic acid).
Further, in addition to zinc oxide, as a metal compound that becomes a metal oxide, a magnesium compound such as magnesium hydroxide, an iron compound such as iron oxide as the metal compound, and a cobalt compound such as cobalt carboxylate as the metal compound may be blended. good.
In the present invention, the vulverable rubber composition needs to contain more than 4 parts by mass of a metal oxide with respect to 100 parts by mass of the rubber component, and preferably contains 5 parts by mass or more of the metal oxide. It is more preferable to contain 6 parts by mass or more of the metal oxide, further preferably 7 parts by mass or more of the metal oxide, and particularly preferably 8 parts by mass or more of the metal oxide. Although there is no upper limit to the amount of the metal oxide to be blended, it is preferable to contain 20 parts by mass or less of the metal oxide from the viewpoint of dispersibility in the rubber composition and economic efficiency, and 18 parts by mass or less of the metal oxide is contained. It is more preferable to contain a metal oxide of 15 parts by mass or less, and it is particularly preferable to contain a metal oxide of 12 parts by mass or less.

(Zinc oxide)
In the present invention, the vulcanizable rubber composition preferably contains more than 4 parts by mass of zinc oxide with respect to 100 parts by mass of the rubber component, more preferably 5 parts by mass or more of zinc oxide, and 6 parts by mass. It is more preferable to contain more than 7 parts by mass of zinc oxide, and it is particularly preferable to contain 7 parts by mass or more of zinc oxide. Although there is no upper limit to the amount of zinc oxide to be blended, it is preferable to contain 20 parts by mass or less of zinc oxide from the viewpoint of dispersibility in the rubber composition and economic efficiency, and it is more preferable to contain 18 parts by mass or less of zinc oxide. It is more preferable to contain 15 parts by mass or less of zinc oxide, further preferably 12 parts by mass or less of zinc oxide, and particularly preferably less than 8 parts by mass.
The vulcanized product, which is a vulcanized rubber product, is 300% above 3 MPa, above 5 MPa in other embodiments, and above 7 MPa in other embodiments, as determined by JIS K6251: 2010 at room temperature. Characterized by tensile tensile stress.

(Filler)
The vulcanizable rubber composition of the present invention may contain one or more fillers. These fillers can include reinforced fillers and non-reinforced fillers. Exemplary fillers include carbon black, silica, and various inorganic fillers.

(Carbon black)
Useful carbon blacks include furnace blacks, channel blacks, and lamp blacks.
More specific examples of carbon black include SAF black, ISAF black, HAF black as furnace black, intermediate treated channel black, hard treated channel black, conductive channel black, and acetylene black as channel black.

Carbon black in certain embodiments of the above 20 m ² / g, in other embodiments can have a CTAB specific surface area of more than 35m ² / g, specific surface area values using cetyl trimethyl ammonium bromide (CTAB) technique Can be determined by ASTM D-1765. ^{The CTAB specific surface area of carbon black is more preferably 50 m 2} / g or more, and further preferably 60 m ² / g or more, from the viewpoint of reinforcing properties of the rubber composition. A CTAB specific surface area of the carbon black, the upper limit is not, it is preferable from the viewpoint of dispersibility secured to the rubber composition is 200 meters ² / g or less, and more preferably less 160 m ² / g.
The carbon black may be in pelletized or non-pelletized cotton-like form.
The preferred form of carbon black may depend on the type of mixer used to mix the rubber composition.

(Inorganic filler)
Examples of the inorganic filler used in the vulcanizable rubber composition of the present invention include inorganic compounds represented by the following general formula (V) other than silica.

nM ・ xSiO _{y ・ zH 2} O ・ ・ ・ ・ ・ (V)

In formula (V), M is a metal selected from the group consisting of aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, and hydrates thereof, or carbonic acid of these metals. At least one selected from salts, n, x, y and z are integers 1-5, 0-10, 2-5 and 0-10, respectively. These fillers may be used alone or in combination of two or more.
Specific examples thereof include aluminum hydroxide, magnesium hydroxide, titanium oxide, boron nitride, iron oxide, mica, talc (hydrated magnesium silicate), and clay (hydrated aluminum silicate).
As the inorganic compound represented by the general formula (V), at least one in which M is selected from aluminum metal, aluminum oxide, aluminum hydroxide, aluminum hydrate, and aluminum carbonate is preferable. .. Of these, aluminum hydroxide is preferable as the filler.

Examples of useful organic fillers include starch.

(silica)
Examples of suitable silica fillers include precipitated amorphous silica, wet silica (hydrated silicic acid), dry silica (silicic anhydride), fumed silica, calcium silicate, aluminum silicate, magnesium silicate and the like. ..

In one or more embodiments, silica may be characterized by their surface area, which gives a measure of their reinforcing properties. Methods for measuring surface area include The Brunauer, Emmet and Teller ("BET") method (described in J. Am. Chem. Soc., Vol. 60, p. 309 et seq.).
The BET surface area of silica is generally ^{less than 450 m 2} / g.
The useful range of the BET surface area of silica is preferably 30 m ² / g or more, more preferably 50 m ² / g or more, still more preferably 80 m ² / g or more, still more, from the viewpoint of improving the reinforcing property of the rubber composition. It can be preferably 100 m ² / g or more, particularly preferably 150 m ² / g or more, and there is no particular upper limit, but from the viewpoint of ensuring dispersibility in the rubber composition, it is preferably 400 m ² / g or less. preferably 300 meters ² / g or less, more preferably 280 meters ² / g or less, even more preferably include 250 meters ² / g or less.

When one or more silicas are used, the pH of the silica is generally about 5 to about 7 or just above 7, or in other embodiments about 5.5 to about 6.8.

Coupling agents and / or shielding agents to enhance the interaction of silica with elastomers in one or more embodiments where silica is used as a filler (alone or in combination with other fillers). Can be added to the rubber composition during mixing.

(Coupling agent)
Useful coupling and shielding agents are disclosed in US Patent Number.
3,842,111, incorporated herein by reference to 3,997,581, 3,978,594, 3,580,919, 3,583,583,245, 5,663,396, 5,674 , 932, 5,684,1711, 5,684,172, 5,696,197, 6,608,145, 6,667,362, 6,579,949, 6,590,017.
Examples of sulfur-containing silane coupling agents include bis (trialkoxysilyl organo) polysulfides or mercapto-organoalkoxysilanes.
Types of bis (trialkoxysilyl organo) polysulfides include bis (trialkoxysilyl organo) disulfides and bis (trialkoxysilyl organo) tetrasulfides.
Specific examples of the bis (trialkoxysilylorgano) polysulfide include bis (trialkoxysilylpropyl) disulfide and bis (trialkoxysilylpropyl) tetrasulfide.

(resin)
As suggested above, the vulcanizable rubber composition of the present invention may contain one or more resins.
These resins may include phenolic resins and hydrocarbon resins such as alicyclic resins, aliphatic resins, aromatic resins, terpene resins, and combinations thereof.
Useful resins include, for example, Chemfax, Dow Chemical Company, Eastman Chemical Company, Idemitsu, Nevile Chemical Company, Nippon, PolySat Inc, Resin Commercially available, and Resin Apple Commercially available.

In one or more embodiments, the useful hydrocarbon resin is at about 30-about 160 ° C, in other embodiments about 35-about 60 ° C, and in other embodiments about 70-about 110 ° C. glass transition temperature (Tg). ) Can be characterized.
In one or more embodiments, the useful hydrocarbon resin can also be characterized in that its softening point is higher than its Tg.
In certain embodiments, the useful hydrocarbon resin has a softening point of about 70-about 160 ° C., in other embodiments about 75-about 120 ° C., and in other embodiments about 120-about 160 ° C.

In certain embodiments, one or more alicyclic resins are used in combination with one or more aliphatic, aromatic, and terpene resins.
In one or more embodiments, one or more alicyclic resins are used as the major mass component (eg, greater than 50% by weight) with respect to the total load of the resin. For example, the resin used comprises at least 55% by weight, at least 80% by weight in other embodiments, and at least 99% by weight in other embodiments of one or more alicyclic resins.

In one or more embodiments, both the alicyclic homopolymer resin and the alicyclic copolymer resin containing those derived from the alicyclic monomer are optionally one or more others. Included in combination with (non-alicyclic) monomers, most of the mass of all monomers is alicyclic.
Non-limiting examples of suitable useful alicyclic resins include cyclopentadiene (“CPD”) homopolymers or copolymer resins, dicyclopentadiene (“DCPD”) homopolymers or copolymer resins, and combinations thereof. Be done.
Non-limiting examples of alicyclic copolymer resins include CPD / vinyl aromatic copolymer resins, DCPD / vinyl aromatic copolymer resins, CPD / terpene copolymer resins, DCPD / terpene copolymer resins, CPD / aliphatic copolymer resins (eg). , CPD / C5 distillate copolymer resin), DCPD / aliphatic copolymer resin (eg, DCPD / C5 distillate copolymer resin), CPD / aromatic copolymer resin (eg, CPD / C9 fraction). DCPD / aromatic copolymer resin (eg DCPD / aromatic copolymer resin), DCPD / aromatic-aliphatic copolymer resin (eg DCPD / C9 fraction copolymer resin), CPD / aromatic-aliphatic copolymer resin (eg DCPD) / C5 and C9 fraction copolymer resin), CPD / vinyl aromatic copolymer resin (eg, CPD / styrene copolymer resin), CPD / vinyl aromatic copolymer resin (eg, DCPD / styrene) copolymer resin), CPD / terpen copolymer resin (eg, CPD / terpen copolymer resin) For example, limonen / CPD copolymer resin) and DCPD / terpen copolymer resin (eg, limonen / DCPD copolymer resin).
In certain embodiments, the alicyclic resin may include one hydrogenated form of the alicyclic resin described above (ie, a hydrogenated alicyclic resin).
In other embodiments, the alicyclic resin eliminates the hydrogenated alicyclic resin; in other words, the alicyclic resin is not hydrogenated.

In certain embodiments, the one or more aromatic resins are used in combination with one or more of the aliphatic, alicyclic, and terpene resins.
In one or more embodiments, one or more aromatic resins are used as the major mass component (eg, greater than 50% by weight) with respect to the total load of the resin. For example, the resin used comprises at least 55% by weight, at least 80% by weight in other embodiments, and at least 99% by weight of another aromatic resin.

In one or more embodiments, an aromatic copolymer comprising an aromatic resin derived from one or more aromatic monomers in combination with an aromatic homopolymer resin and one or more other (non-aromatic) monomers. The maximum amount of any type of monomer, including both with resin, is aromatic.
Non-limiting examples of useful aromatic resins include kumaron-inden resins and alkyl-phenol resins, as well as vinyl aromatic homopolymers or copolymer resins (eg, derived from one or more of the following monomers): Are: α-methylstyrene, styrene, orthomethylstyrene, metamethylstyrene, paramethylstyrene, vinyltoluene, parra (tert-butyl) styrene, methoxystyrene, chlorostyrene, hydroxystyrene, vinylmethylene, divinylbenzene, vinylnaphthalene, or Any vinyl aromatic monomer resulting from the C9 distillate or the C8-C10 distillate.
Non-limiting examples of vinyl aromatic copolymer resins include vinyl aromatic / terpene copolymer resins (eg limonene / styrene copolymer resins), vinyl aromatic / C5 distillate resins (eg C5 distillates / styrene copolymer resins). , Vinyl aromatic / aliphatic copolymer resin (for example, CPD (cyclopentadiene) / styrene copolymer resin, and DCPD (dicyclopentadiene) / styrene copolymer resin).
Non-limiting examples of alkylphenol resins include alkylphenol-acetylene resins such as p-tert-butylphenol-acetylene resins, alkylphenol-formaldehyde resins (such as those having a low degree of polymerization), but in certain embodiments, aromatics. The resin may include a hydrogenated form of one of the above aromatic resins (ie, a hydrogenated aromatic resin).
In other embodiments, the aromatic resin excludes the hydrogenated aromatic resin, in other words, the aromatic resin is not hydrogenated.

In certain embodiments, the one or more aliphatic resins are used in combination with one or more alicyclic, aromatic and terpene resins.
In one or more embodiments, one or more aliphatic resins are used as the major mass component (eg, greater than 50% by weight) relative to the total load of the resin. For example, the resin used comprises at least 55% by weight, at least 80% by weight in other embodiments, and at least 99% by weight in other embodiments.

In one or more embodiments, the aliphatic resin is derived from one or more aliphatic monomers in combination with an aliphatic homopolymer resin and one or more other (non-aliphatic) monomers. Including.
Non-limiting examples of useful aliphatic resins include C5 distillate homopolymers or copolymer resins, C5 distillate / C9 distillate copolymer resins, C5 distillate / vinyl aromatic copolymer resins (eg, C5 distillate / styrene). Copolymer resin), C5 distillate / alicyclic copolymer resin, C5 distillate / C9 distillate / alicyclic copolymer resin, and combinations thereof.
Non-limiting examples of alicyclic monomers include, but are not limited to, cyclopentadiene (“CPD”) and dicyclopentadiene (“DCPD”).
In certain embodiments, the aliphatic resin may comprise a hydrogenated form of one of the above-mentioned aliphatic resins (ie, a hydrogenated aliphatic resin).
In other embodiments, the aliphatic resin eliminates the hydrogenated aliphatic resin; in other words, in such an embodiment, the aliphatic resin is not hydrogenated.

In one or more embodiments, both the terpene homopolymer resin and the terpene copolymer resin, including those in which the terpene resin is derived from one or more terpene monomers combined with one or more other (non-terpene) monomers. The maximum amount of any type of monomer, including terpenes, is terpenes.
Non-limiting examples of useful terpene resins include alpha-pinene resins, beta-pinene resins, limonene resins (eg, dipentene, a racemic mixture of L-limonenes, D-limonenes, L- and D-isomers). , Beta-ferrandrene, delta-3-calene, delta-2-calene, pinene-limonene copolymer resin, terpene-phenolic resin, aromatic-modified terpene resin, and combinations thereof.
In certain embodiments, the terpene resin can include a hydrogenated form of one of the above-mentioned terpene resins (ie, a hydrogenated terpene resin).
In other embodiments, the terpene resin eliminates the hydrogenated terpene resin; in other words, in such an embodiment the terpene resin is not hydrogenated.

(Vulcanizing agent)
In the rubber composition of the present invention, sulfur or a sulfur-containing vulcanizing agent is preferably used as the vulcanizing agent, and sulfur is particularly preferable. Sulfur or a sulfur-containing vulcanizing agent is used as the sulfur content in an amount of 0.5 to 12 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.
For example, the sulfur content used in the side reinforcing rubber of a run-flat tire is preferably 3 to 10 parts by mass and more preferably 3.3 to 9 parts by mass with respect to 100 parts by mass of the rubber component. It is more preferable to use 5 to 8 parts by mass.
As the sulfur, powdered sulfur, powdered insoluble sulfur (insoluble polymer sulfur) and the like are used.
Examples of suitable sulfur-containing vulcanizers include sulfur-donating vulcanizers such as amine disulfide, polymer polysulfides or sulfur olefin adducts.
The vulcanizing agent can be used alone or in combination. Also, the amount of vulcanizing agent can be easily selected to achieve the desired vulcanization level.
In the present invention, if desired, a peroxide-based cross-linking agent may be used in addition to the sulfur or sulfur-containing vulcanizing agent. However, when a peroxide-based cross-linking agent is used in addition to the sulfur or sulfur-containing vulcanizing agent, It is preferable not to use a sulfur-based cross-linking agent because the elongation at break of the rubber composition is reduced and the fracture resistance is deteriorated.

(Vulcanization accelerator)
In one or more embodiments, the vulcanizing agent is used in combination with a vulcanization accelerator.
In one or more embodiments, the vulcanization accelerator is used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanized product.
Examples of accelerators include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazil-sulfenamide (CBS), N-tert-butyl-2-benzothia. Includes sulfenamide vulcanization accelerators such as zoryl sulfenamide and guanidine vulcanization accelerators such as diphenylguanidine (DPG).
In the present invention, the amount of vulcanization accelerator can be easily selected to achieve the desired curing level.

(Other compounding agents)
Other formulations typically used in rubber formulations can also be added to the rubber composition.
These include accelerators, accelerator activators, oils, additional plasticizers, waxes, scorch inhibitors, processing aids, zinc oxide, tackifier resins, reinforced resins, fatty acids such as stearic acid, solubilizers, and Decomposition inhibitors such as antioxidants and anti-ozone agents are included.
In certain embodiments, those conventionally used as softeners are included. Useful oils or bulking agents that can be used as softeners include aromatic oils, parlaffin oils, naphthenic oils, vegetable oils other than castor oil, low PCA oils containing MES, TDAE, and SRAE, and heavy naphthenic oils. Included, but not limited to.
Suitable low PCA oils also include oils of various plant origins, such as those that can be harvested from vegetables, nuts, and seeds.
Non-limiting examples include soybean or soybean oil, sunflower oil, benibana oil, corn oil, flaxseed oil, cottonseed oil, rapeseed oil, cashew oil, sesame oil, camellia oil, hover oil, macadamia nut oil, coconut oil, and palm oil. These include, but are not limited to.

In one or more embodiments, the organic acid is a carboxylic acid.
In certain embodiments, the carboxylic acid is a fatty acid, including saturated and unsaturated fatty acids.
In certain embodiments, saturated fatty acids such as stearic acid are used.
Other useful acids include, but are not limited to, permicinic acid, arachidic acid, oleic acid, linoleic acid, and arachidonic acid.

(Amount of eutectic compound compounded)
In one or more embodiments, the vulcanizable rubber composition exceeds 0.005 parts by mass with respect to 100 parts by mass of the rubber component, and in other embodiments, it exceeds 0.01 parts by mass. Contains more than 0.02 parts by mass of eutectic compounds.
In these or other embodiments, the vulcanizable rubber composition is less than 3 parts by mass, less than 1 part by mass in other embodiments, and 0.1 parts by mass in other embodiments, relative to 100 parts by mass of the rubber component. Contains less than a portion of eutectic compounds.
In one or more embodiments, the vulcanizable rubber composition is about 0.005 to about 3 parts by mass with respect to 100 parts by mass of the rubber component, and in other embodiments is about 0.01 to about 1 part by mass. In other embodiments, it comprises from about 0.02 to about 0.1 parts by weight of the eutectic compound.

In one or more embodiments, the amount of the eutectic compound can be described with reference to the amount of the metal oxide (such as zinc oxide) blended.
In one or more embodiments, the vulcanizable composition is greater than 2% by weight based on the total mass of eutectic compounds and metal oxides (eg, zinc oxide) present in the vulcanizable composition. , In other embodiments greater than 3% by weight, and in other embodiments greater than 5% by weight vulcanizing solvent.
In these or other embodiments, the vulcanizable composition is less than 20% by weight, based on the total mass of eutectic compounds and metal oxides (eg, zinc oxide) present in the vulcanizable composition. Other embodiments contain less than 15% by weight, and other embodiments contain less than 12% by weight vulcanizing solvent.
In one or more embodiments, the vulcanizable composition is about 2 to about 15 based on the total mass of eutectic solvents and metal oxides (eg, zinc oxide) present in the vulcanizable composition. It contains about 3 to about 12% by weight of vulcanized compounds in other embodiments and about 5 to about 10% by weight in other embodiments.

(Organic acid)
In one or more embodiments, the vulcanizable rubber composition exceeds 0.5 parts by mass with respect to 100 parts by mass of the rubber component, and in other embodiments, it exceeds 0.7 parts by mass, and the other embodiment. Contains more than 1.0 parts by mass of organic acids (eg stearic acid).
In these or other embodiments, the vulcanizable rubber composition comprises less than 5 parts by mass, in other embodiments less than 3 parts by mass, and in other embodiments less than 2 parts by mass of an organic acid (eg stearic acid). Including.
In one or more embodiments, the vulcanizable rubber composition is about 0.5 to about 5 parts by mass with respect to 100 parts by mass of the rubber component, and in other embodiments is about 0.7 to about 3 parts by mass. In other embodiments, it comprises from about 1.0 to about 2 parts by weight of organic acid (eg stearic acid) by weight.

(Amount of filler compounded)
In one or more embodiments, the vulcanizable rubber composition is at least 0 parts by mass, at least 10 parts by mass in other embodiments, and at least 20 parts by mass in other embodiments, relative to 100 parts by mass of the rubber component. Includes filler.
In these or other embodiments, the vulcanizable rubber composition comprises at most 200 parts by mass, in other embodiments at most 100 parts by mass, and in other embodiments at most 70 parts by mass.
In one or more embodiments, the vulcanizable rubber composition is from about 0 to about 200 parts by mass, in other embodiments from about 10 to about 100 parts by mass, and in other embodiments from about 20 to about 70 parts by mass. Includes filler.

(Amount of carbon black blended)
In one or more embodiments, the vulcanizable rubber composition comprises at least 0 parts by mass, at least 10 parts by mass in other embodiments, and at least 20 parts by mass in other embodiments, relative to 100 parts by mass of the rubber component. Contains carbon black.
In these or other embodiments, the vulcanizable rubber composition comprises at most 200 parts by mass, in other embodiments at most 100 parts by mass, and in other embodiments at most 70 parts by mass of carbon black.
In one or more embodiments, the vulcanizable rubber composition is about 0 to about 200 parts by mass with respect to 100 parts by mass of the rubber component, in other embodiments about 10 to about 100 parts by mass, and other embodiments. Contains about 20 to about 70 parts by mass of carbon black.

(Silica compounding amount)
In one or more embodiments, the vulcanizable rubber composition comprises at least 5 parts by mass, at least 25 parts by mass in other embodiments, and at least 50 parts by mass in other embodiments, relative to 100 parts by mass of the rubber component. Contains silica.
In these or other embodiments, the vulcanizable rubber composition is up to 200 parts by mass, up to 130 parts by mass in other embodiments, and up to 80 parts by mass with respect to 100 parts by mass of the rubber component. Contains parts by mass of silica.
In one or more embodiments, the vulcanizable rubber composition is about 5 to about 200 parts by mass with respect to 100 parts by mass of the rubber component, in other embodiments about 25 to about 130 parts by mass, and in other embodiments. Contains about 50 to about 80 parts by mass of silica.

(Filling ratio of filler)
In the vulcanizable rubber composition of the present invention, carbon black alone or silica alone may be blended, but both carbon black and silica may be blended.
In one or more embodiments, the vulcanizable rubber composition can be characterized by the ratio of the amount of the first filler to the amount of the second filler.
In one or more embodiments, the ratio of carbon black to silica amounts is about 1: 1, in other embodiments about 10: 1, in other embodiments about 14: 1, and in other embodiments about 20 :. It is 1.
In one or more embodiments, the ratio of the amount of carbon black to silica is about 1: 5, in other embodiments about 1:10, in other embodiments about 1:14, and in other embodiments about 1. : 20.

(Amount of silane coupling agent compounded)
In one or more embodiments, the vulcanizable rubber composition contains at least 1 part by weight of silane, at least 2 parts by weight in other embodiments, and at least 5 parts by weight in other embodiments, relative to 100 parts by weight of silica. A coupling agent may be included.
In these or other embodiments, the vulcanizable rubber composition is at most 20 parts by weight, in other embodiments at most 15 parts by weight, and at most in other embodiments, relative to 100 parts by weight of silica. It may contain 10 parts by mass of a silane coupling agent.
In one or more embodiments, the vulcanizable rubber composition is about 1 to about 20 parts by weight, in other embodiments about 2 to about 15 parts by weight, with respect to 100 parts by weight of silica, in other embodiments. It may contain about 5 to about 10 parts by mass of the silane coupling agent.

(Amount of resin compounded)
In one or more embodiments, the vulcanizable rubber composition is more than 1 part by weight with respect to 100 parts by weight of rubber, more than 15 in other embodiments, and more than 25 parts by weight in other embodiments. For example, hydrocarbon resin) is included.
In these or other embodiments, the vulcanizable rubber composition is less than 150 parts by mass with respect to 100 parts by mass of rubber, less than 120 parts by mass in other embodiments, and less than 90 parts by mass in other embodiments. (For example, hydrocarbon resin) is included.
In one or more embodiments, the vulcanizable rubber composition is about 1 to about 150 parts by mass, in other embodiments about 15 to about 120 parts by mass, and in other embodiments about 25 to about 90 parts by mass of resin. (For example, hydrocarbon resin) Contains parts by mass.

(Manufacturing method of rubber composition)
The method for producing a rubber composition according to the present invention includes a step of mixing a rubber component, an organic salt liquid at room temperature, and a component containing more than 4 parts by mass of a metal oxide with respect to 100 parts by mass of the rubber component.
Here, the organic salt that is liquid at room temperature refers to the above-mentioned eutectic compound that is a deep eutectic solvent (DES) that is liquid at room temperature (23 ° C.). Room temperature is room temperature (23 ° C.).
The method for producing a rubber composition according to the present invention is
(i) A step (A) of kneading a rubber component, a eutectic compound, and a metal oxide to produce a masterbatch.
(ii) A method for producing a rubber composition, which comprises a step (B) of kneading the masterbatch and a sulfur-based vulcanizing agent to produce a rubber composition, is preferable.
In one or more embodiments, the vulcanizable composition is prepared by mixing a vulcanizable rubber with a vulcanizing solvent to form a masterbatch, followed by the addition of a vulcanizing agent to the masterbatch. ..
Masterbatch preparation is, for example, one or more subs in which one or more components can be added continuously to the composition, if desired, after the first mixture is prepared by mixing two or more components. It can be done using a mixing step.
Also, using conventional techniques, processing aids such as carbon black, additional fillers, chemically treated inorganic oxides, silica, silane coupling agents, silica dispersants, processing oils, zinc oxide and fatty acids. , And additional components such as antioxidants such as antioxidants or antioxidants can be added in the preparation of vulcanizable compositions, but not limited to these.

In the present invention, the eutectic compound is preferably prepared by mixing a quaternary ammonium salt and a hydrogen bond donor. In the present invention, it is preferable that the eutectic compound is prepared before introducing the eutectic compound into the rubber component.
That is, the first component (quaternary ammonium salt) of the mixture constituting the eutectic compound is the second component (hydrogen bond donor) of the mixture before the eutectic compound is introduced into the vulverable rubber composition. Is preferably premixed with.
In one or more embodiments, the combined components of the mixture are mixed until a homogeneous liquid composition is observed.

By blending the eutectic compound, even in a rubber composition containing a large amount of metal oxide, the dispersibility of the metal oxide in the rubber composition can be improved and the vulcanization reaction time can be shortened.
By blending both the eutectic compound and the metal oxide in the rubber composition, the dispersibility of the metal oxide in the rubber composition is improved, and the vulcanization return property can be dramatically improved. ..
In these embodiments, it is presumed that the eutectic compound is a carrier of a metal oxide such as zinc oxide.
For example, a eutectic compound can be combined with a larger amount of a metal oxide such as zinc oxide, and a metal oxide such as zinc oxide can be prepared in a mixer by combining a metal oxide such as zinc oxide and a eutectic compound as a solid. Acts as a carrier for delivery to rubber.
In yet another embodiment, one of the members of the eutectic pair acts as a solid carrier for the eutectic compound, so the combination of the first and second components of the eutectic compound is on the rubber in the mixer. Form a preliminary combination that can be added as a solid.
In the present invention, a mixture of this property is formed by excessive combination of excess first or second eutectic members with respect to other eutectic members in order to maintain the solid composition at a desired temperature. You will understand that you can.

In one or more embodiments, the eutectic compound is introduced into the vulcanizable rubber composition as an initial component in the formation of the rubber masterbatch.
As a result, the eutectic compound undergoes high shear and high temperature mixing with the rubber component.
In one or more embodiments, the eutectic compound (particularly the eutectic solvent) has a minimum temperature above 110 ° C., another embodiment a minimum temperature above 130 ° C., and another embodiment a minimum temperature above 150 ° C. Mixed with rubber components at temperature.
In one or more embodiments, the high shear high temperature mixing is performed at a temperature of about 110 ° C to about 170 ° C.

In another embodiment, the eutectic compound is introduced with the vulcanizing agent into the rubber, which can be vulcanized continuously or simultaneously.
As a result, the eutectic compound is mixed with the vulcanizable rubber at a maximum temperature of less than 110 ° C., less than 105 ° C. in other embodiments and less than 100 ° C. in other embodiments.
In one or more embodiments, mixing with the vulcanizing agent is carried out at a temperature of about 70 ° C to about 110 ° C.

Like eutectic compounds, metal oxides such as zinc oxide and stearic acid can be added to the rubber masterbatch as initial components, thus these components are subject to high temperature, high shear mixing.
Alternatively, metal oxides such as zinc oxide and stearic acid can be added together with the sulfur-based vulcanizer, thereby only subject to low temperature mixing.

In one or more embodiments, metal oxides such as zinc oxide are introduced into the vulcanizable rubber separately from the eutectic compound.
In other embodiments, it is preferred that a metal oxide such as zinc oxide and a eutectic compound are premixed to form a metal oxide master batch, particularly a zinc oxide master batch, to give a zinc oxide master batch. In this case, it is preferable that zinc oxide is dissolved in the eutectic compound. In a zinc oxide master batch which is a mixture of zinc oxide and a eutectic compound, when zinc oxide is dissolved in the eutectic compound, the rubber composition of zinc oxide is obtained by adding this zinc oxide master batch to the rubber composition. Dispersion in the object is improved.

(Mixed conditions)
In one or more embodiments, the vulcanizable composition first combines the vulcanizable rubber with the eutectic compound at a temperature of about 110 to about 180 ° C., or in other embodiments from about 130 to about 170 ° C. Prepared by mixing in.
In certain embodiments, following the initial mixing, the composition (ie, masterbatch) is cooled to a temperature below 100 ° C., or in other embodiments below 80 ° C., and a vulcanizing agent is added.
In certain embodiments, mixing is continued at a temperature of about 90 to about 110 ° C., or in other embodiments about 95 to about 105 ° C., to prepare the final vulcanizable rubber composition.

In one or more embodiments, the masterbatch mixing step, or one or more substeps of the masterbatch mixing step, can be characterized by the peak temperature obtained by the composition during mixing. This peak temperature is also called the fall temperature.
In one or more embodiments, the peak temperature of the composition during the masterbatch mixing step may be at least 140 ° C., at least 150 ° C. in other embodiments, and at least 160 ° C. in other embodiments.
In these or other embodiments, the peak temperature of the composition during the masterbatch mixing step is from about 140 to about 200 ° C., in other embodiments from about 150 to about 190 ° C., and in other embodiments from about 160 to about 180 ° C. It may be.

(Final mixing process)
Following the masterbatch mixing step, a vulcanizing agent or vulcanizing agent system is introduced into the composition and mixing is continued to finally form a vulcanizable material composition.
This mixing step can be referred to as a final mixing step, a vulcanization mixing step, or a productive mixing step.
The product obtained from this mixing step can be referred to as a vulcanizable rubber composition (or unvulcanized rubber composition).

In one or more embodiments, the final mixing step can be characterized by the peak temperature obtained by the composition during the final mixing.
In the present invention, this temperature is also referred to as the final droplet temperature.
In one or more embodiments, the peak temperature of the composition during final mixing may be at most 130 ° C., at most 110 ° C. in other embodiments, and at most 100 ° C. in other embodiments.
In these or other embodiments, the peak temperature of the composition during final mixing is from about 80 to about 130 ° C, in other embodiments from about 90 to about 115 ° C, and in other embodiments from about 95 to about 105 ° C. You may.

(Mixing device)
All components of the vulcanizable rubber composition can be mixed with standard mixers such as internal mixers (eg, Banbury mixers, internal mixers, etc.), extruders, kneaders, and double roll mills.
Mixing can be done alone or in tandem.
As suggested above, the ingredients can be mixed in a single step, or in other embodiments in two or more steps.
For example, a masterbatch is prepared in the first step (ie, the mixing step), which typically comprises rubber components and fillers.
Once the masterbatch is prepared, the vulcanizer may be introduced into the masterbatch at the final mixing stage and mixed, which is typically relatively low to reduce the chance of premature vulcanization. It is done at temperature.
An additional mixing step, sometimes called a remil, can be used between the masterbatch mixing step and the final mixing step.

The vulcanizable rubber composition can be processed into tire components according to conventional tire manufacturing techniques, including standard rubber molding, molding and curing techniques.
Typically, vulcanization is carried out by heating the vulcanizable composition in a mold, for example, it can be heated to about 140 ° C. to about 180 ° C.
The cured or vulcanized rubber composition may also be referred to as vulcanized rubber, which generally comprises a thermosetting three-dimensional polymer network.
Other components such as fillers and processing aids can be uniformly dispersed throughout the vulcanization network.
Pneumatic tires can be manufactured as described in the US Patent Number below.
5,866,171, 5,876,527, 5,931,211 and 5,971,046 (these are incorporated herein by reference).

(Vulcanized rubber products)
As described above, the vulcanizable rubber composition of the present invention is vulcanized and cured to become a vulcanized rubber product. Examples of the vulcanized rubber product include those selected from the group consisting of tires, anti-vibration rubbers, seismic isolation rubbers, conveyor belts, hoses, and crawlers.

According to the aspect of the present invention, the vulcanized rubber product which is a vulcanized product can obtain advantageous vulcanization characteristics while containing a metal oxide such as zinc type.

Hereinafter, the present embodiment will be described in more detail with reference to Examples, but the present embodiment is not limited to these Examples.
The rubber composition and the vulcanized product of the rubber composition in the examples were evaluated by the following methods.
Unless otherwise specified, all amounts are represented by parts by mass with respect to 100 parts by mass of the rubber component.
1. 1. Vulcanization characteristics (1) Using each of the prepared rubber compositions, a curast meter (“Rotarless Leometer RLR-4” manufactured by Toyo Seiki Co., Ltd.), in accordance with JIS K6300-2: 2001, 10 at 160 ° C. % Vulcanization time {tk (10)} (unit: minutes), 90% vulcanization time {tk (90)} (unit: minutes) and maximum torque (Fmax) (unit: dN · m) were measured.
(2) Vulcanization returnability (index)
As an index of vulcanization returnability, the slope of the vulcanization curve after the maximum torque (Fmax) (unit: dN · m) was quantified, and the slope of Comparative Example 1 was indexed as 100. The larger the value, the more difficult it is to return to vulcanization.

[Formation of eutectic compounds]
The eutectic compound was prepared by mixing 1 mol of choline chloride and 2 mol of urea at 100 ° C. to form an eutectic compound. It was cooled to room temperature (23 ° C.) under standard conditions (1 atm).
The eutectic compound composed of choline chloride and urea is also called a eutectic solvent or a deep eutectic solvent (DES), and is liquid at room temperature (23 ° C.).

[Mixing of eutectic compound and zinc oxide]
Next, the eutectic compound and zinc oxide are mixed in a mixer at a ratio of mass ratio (0.1 part by mass of eutectic compound / 1.0 part by mass of zinc oxide), and a mixture of the eutectic compound and zinc oxide is mixed. Got

Examples 1-2 and Comparative Examples 1-8
The rubber compositions having the compounding compositions provided in Tables 1 and 2 were prepared by the following procedure.
Based on the compounding composition shown in Tables 1 and 2, a masterbatch of the rubber component, stearic acid and the antiaging agent was obtained by the step (A) (masterbatch mixing step) of producing a masterbatch with a Banbury mixer. The Banbury mixer was operated at 70 RPM (rotation / min) and kneaded at a maximum temperature of 160 ° C. This maximum temperature means the maximum temperature in the masterbatch immediately after being discharged from the Bambari mixer. The masterbatch was cooled to room temperature (23 ° C.) after step (A) (masterbatch mixing step).
Next, in the step (B) for producing the rubber composition after the mixing step (A), various master batches, a mixture of a eutectic compound and zinc oxide, zinc oxide or a eutectic compound other than the mixture, and a vulcanization accelerator. And sulfur were operated with a Banbury mixer at 40 RPM (rotation / min), kneaded at a maximum temperature of 100 ° C., and then cooled to room temperature (23 ° C.).
The vulcanization characteristics and vulcanization returnability of the obtained 10 types of rubber compositions were evaluated by the above methods. The results are shown in Tables 1 and 2.

The components shown in Tables 1 and 2 are as follows.
* 1: Polyisoprene rubber: manufactured by JSR Corporation, product name "JSR IR2200"
* 2: Stearic acid: Kao Corporation, product name "Lunac S-50V"
* 3: Anti-aging agent: N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, manufactured by Seiko Kagaku Co., Ltd., trade name "Ozonone 6C"
* 4: Zinc oxide: Made by Sakai Chemical Industry Co., Ltd., trade name "Zinc oxide 1 type"
* 5: Eutectic compound: As described above, a eutectic compound obtained by mixing 1 mol of choline chloride and 2 mol of urea at 100 ° C. Choline chloride: manufactured by Kanto Chemical Co., Inc., trade name "choline chloride""
Urea: Made by Kanto Chemical Co., Inc., trade name "Urea"
* 6: Vulcanization accelerator: N-tert-butyl-2-benzothiazolyl sulfeneamide, manufactured by Sanshin Kagaku Kogyo Co., Ltd., trade name "Sunseller NS"
* 7: Sulfur: Made by Sanshin Chemical Industry Co., Ltd., product name "Sanfel EX"
* 8: Natural rubber: RSS # 3

From Tables 1 and 2, it can be seen that the dispersibility of zinc oxide in the rubber composition can be significantly improved in the presence of the eutectic compound. That is, in the presence of the eutectic compound, it was possible to obtain a rubber composition in which a rubber composition containing a large amount of metal oxide can enjoy improved vulcanization characteristics and rubber physical characteristics after vulcanization. In Table 1, as an evaluation of vulcanization returnability, the main chain breakage was evaluated with isoprene skeleton rubber, which is more likely to occur than other diene rubbers. However, polymer components composed of other diene rubbers, isoprene skeleton rubbers and other dienes were evaluated. The invention of the present application improves the vulcanization returnability even when the system rubber is contained as a polymer component. Further, although Table 1 does not contain a filler typified by silica or carbon black, the vulcanization returnability is similarly improved even when a filler is contained.

In the rubber composition of the present invention, the vulcanization reaction time is shortened and the 100% elongation tensile stress is further increased by increasing the blending amount of a metal oxide such as zinc oxide in the presence of a eutectic compound. In particular, since the vulcanization returnability of the rubber composition after vulcanization could be dramatically improved, the side reinforcing rubber of the run flat tire, the run flat tire, the tire, the anti-vibration rubber, the seismic isolation rubber, and the conveyor It is suitably used for vulcanized rubber products such as belts, hoses and crawlers.

Claims (12)

A rubber composition containing a rubber component, a eutectic compound, and a metal oxide exceeding 4 parts by mass with respect to 100 parts by mass of the rubber component. The rubber composition according to claim 1, wherein the metal oxide is an oxide of zinc. The rubber composition according to claim 1, wherein the eutectic compound is a mixed product of an onium salt and a hydrogen bond donor. The rubber composition according to claim 3, wherein the onium salt is at least one selected from the group consisting of an ammonium salt, a sulfonium salt and a phosphonium salt. The rubber composition according to claim 3, wherein the hydrogen bond donor contains a structure derived from at least one selected from a urea derivative and an alkylene glycol in the molecule. The rubber composition according to claim 3 or 4, wherein the onium salt is an ammonium salt. The rubber composition according to claim 6, wherein the ammonium salt is a quaternary ammonium salt. The rubber composition according to claim 7, wherein the quaternary ammonium salt is choline chloride. The rubber composition according to any one of claims 1 to 8, which is used for a run-flat tire. A tire comprising the vulcanized rubber composition according to any one of claims 1 to 8. A run-flat tire comprising the vulcanized rubber composition according to any one of claims 1 to 9. A method for producing a rubber composition, which comprises a step of mixing a rubber component, an organic salt liquid at room temperature, and a component containing more than 4 parts by mass of a metal oxide with respect to 100 parts by mass of the rubber component.