WO2019151127A1 - Composition, cross-linked molded body, and tire - Google Patents

Abstract

Provided is a composition for creating a molded body that can improve work efficiency by effectively suppressing cold flow and that has high strength and outstanding wear resistance. This composition contains a polymer (A) that includes a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and water (B). The average ethylene sequence length of the polymer (A) is 2–20. The iodine value of the polymer (A) is 10–100, and if the content of the polymer (A) is Ma (parts by mass) and the content of the water (B) is Mb (parts by mass), Ma / Mb = 50–2000.

Description

Composition, crosslinked molded body and tire

The present invention relates to a composition, a crosslinked molded article, and a tire.

Copolymers of conjugated diene compounds and aromatic vinyl compounds have good properties such as heat resistance, wear resistance, mechanical strength, and moldability, so pneumatic tires, hoses, anti-vibration rubber, etc. It is used for various applications.

For example, pneumatic tires are required to improve fuel efficiency due to environmental conditions such as global warming due to carbon dioxide emissions, increased awareness of resource and energy savings, and economic conditions such as the recent rise in gasoline prices. ing. Conventionally, various conjugated diene rubbers have been proposed in order to meet such demands (see, for example, Patent Document 1). Patent Document 1 discloses a conjugated diene rubber whose terminal is modified with a functional group. End-modified conjugated diene rubber has better compatibility with fillers as reinforcing agents such as carbon black and silica compared to unmodified conjugated diene rubber, so it can suppress heat generation and improve fuel efficiency. Is possible.

JP 2003-171418 A

However, the conventional conjugated diene rubbers tend to generate cold flow, and the bale shape stability of the raw rubber before crosslinking is not particularly satisfactory.

Therefore, some aspects according to the present invention can improve work efficiency by effectively suppressing cold flow by solving at least a part of the above problems, and are excellent in high strength and wear resistance. It is an object of the present invention to provide a composition for producing a molded body.

The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following aspects or application examples.

[Application Example 1]
One aspect of the composition according to the present invention is:
A polymer (A) having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound;
Water (B),
Containing
The polymer (A) has an average ethylene chain length of 2 to 20,
The iodine value of the polymer (A) is 10 to 100,
When the content of the polymer (A) is Ma (parts by mass) and the content of the water (B) is Mb (parts by mass), Ma / Mb = 50 to 2000.

[Application Example 2]
In the composition of the above application example,
The polymer (A) may be a polymer containing butadiene as the conjugated diene compound and having a vinyl bond content of a structural unit derived from the butadiene of 60 mol% or less.

[Application Example 3]
In the composition of the above application example,
One or more functional groups selected from the group consisting of an amino group, a group having a carbon-nitrogen double bond, a nitrogen-containing heterocyclic group, a phosphino group, a thiol group, and a hydrocarbyloxysilyl group at the terminal of the polymer (A). Can have.

[Application Example 4]
One aspect of the crosslinked molded article according to the present invention is:
It was created using the composition of the above application example.

[Application Example 5]
One aspect of the tire according to the present invention is:
The crosslinked molded body of the above application example is used as a material of at least dread or sidewall.

According to the composition of the present invention, it is possible to improve the working efficiency by suppressing the cold flow, and it is possible to produce a crosslinked molded article having high strength and excellent wear resistance.

Hereinafter, preferred embodiments according to the present invention will be described in detail. It should be understood that the present invention is not limited to only the embodiments described below, and includes various modifications that are implemented without departing from the scope of the present invention.

In this specification, a numerical range described using “to” means that numerical values described before and after “to” are included as a lower limit value and an upper limit value.

In this specification, “room temperature” is a temperature of 1 to 30 ° C., but is a temperature of 25 ° C. particularly when a test or the like is performed.

“(Meth) acrylic” is a concept encompassing both “acrylic” and “methacrylic”. Further, “˜ (meth) acrylate” is a concept encompassing both “˜acrylate” and “˜methacrylate”.

1. Composition The composition according to the present embodiment contains a polymer (A) having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, and water (B), The average ethylene chain length of the polymer (A) is 2 to 20, the iodine value of the polymer (A) is 10 to 100, the content of the polymer (A) is Ma (parts by mass), When the content of water (B) is Mb (parts by mass), Ma / Mb = 50 to 2000.
Hereinafter, each component contained in the composition according to the present embodiment will be described in detail.

1.1. Polymer (A)
The polymer (A) contained in the composition according to this embodiment has a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound. A polymer (A) may have other structural units other than the said structural unit. The polymer (A) may be either a random copolymer or a block copolymer.

The content ratio of the polymer (A) in the composition according to the present embodiment is preferably 50 parts by mass or more, more preferably 55 parts by mass or more and 99.99 parts by mass when the total solid content of the composition is 100 parts by mass. It is 998 parts by mass or less.

Hereinafter, the structural unit constituting the polymer (A) will be described.

1.1.1. Structural unit derived from conjugated diene compound The polymer (A) has a structural unit derived from a conjugated diene compound. Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene, 2-phenyl- 1,3-butadiene, 3-methyl-1,3-pentadiene, 2-chloro-1,3-butadiene and the like can be mentioned, and one or more selected from these can be used. Of these, 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene are preferred.

The content ratio of the structural unit derived from the conjugated diene compound in the polymer (A) is preferably 50 to 95 parts by mass when the total structural unit of the polymer (A) is 100 parts by mass. More preferably, it is 95 parts by mass. When the content ratio of the structural unit derived from the conjugated diene compound is in the above range, it becomes easy to produce a crosslinked molded article having an excellent balance between high strength and wear resistance.

1.1.2. Structural unit derived from aromatic vinyl compound The polymer (A) has a structural unit derived from an aromatic vinyl compound. Examples of the aromatic vinyl compound include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, and 4-t-butyl. Styrene, 5-t-butyl-2-methylstyrene, vinylethylbenzene, divinylbenzene, trivinylbenzene, divinylnaphthalene, t-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl) dimethylaminoethyl ether, N, N -Dimethylaminoethylstyrene, N, N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-t-butylstyrene, 3-t-butylstyrene, 4-t-butylstyrene , Vinyl xylene, vinyl naphthalate , Vinylpyridine, diphenylethylene, tertiary amino group-containing diphenylethylene (for example, 1- (4-N, N-dimethylaminophenyl) -1-phenylethylene) and the like are selected from these There can be one or more. Of these, styrene and 2-methylstyrene are preferable as the aromatic vinyl compound.

The content ratio of the structural unit derived from the aromatic vinyl compound in the polymer (A) is preferably 5 to 40 parts by mass when the total structural unit of the polymer (A) is 100 parts by mass, The amount is more preferably 10 to 40 parts by mass, and particularly preferably 10 to 35 parts by mass. When the content ratio of the structural unit derived from the aromatic vinyl compound is in the above range, it becomes easy to produce a crosslinked molded article having an excellent balance between high strength and wear resistance.

1.1.3. Other Structural Units The polymer (A) may have other structural units other than the above structural units. Examples of other structural units include repeating units derived from non-conjugated olefins. Examples of the non-conjugated olefin include unsaturated carboxylic acid esters, unsaturated carboxylic acids, α, β-unsaturated nitrile compounds, propylene, and ethylene. When the total structural unit of the polymer (A) is 100 parts by mass, the other structural unit is preferably less than 25 parts by mass, and more preferably 15 parts by mass or less.

The unsaturated carboxylic acid ester is preferably a (meth) acrylic acid ester. Specific examples of such (meth) acrylic acid esters include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, (meth ) N-butyl acrylate, i-butyl (meth) acrylate, n-amyl (meth) acrylate, i-amyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth ) 2-ethylhexyl acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylic Ethylene glycol, di (meth) acrylic acid ethylene glycol, di (meth) acrylic acid propylene glycol , Trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, allyl (meth) acrylate, and the like. Can be one or more. Of these, one or more selected from methyl (meth) acrylate, ethyl (meth) acrylate and 2-ethylhexyl (meth) acrylate is preferable, and methyl (meth) acrylate is particularly preferable. preferable.

Specific examples of the unsaturated carboxylic acid include mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, and the like. One type selected from these That can be the end. In particular, at least one selected from acrylic acid, methacrylic acid and itaconic acid is preferable.

Specific examples of the α, β-unsaturated nitrile compound include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile, vinylidene cyanide, and one or more selected from these. Can be. Of these, at least one selected from acrylonitrile and methacrylonitrile is preferable, and acrylonitrile is particularly preferable.

Moreover, the polymer (A) may further have a structural unit derived from the compound shown below. Examples of such compounds include fluorine-containing compounds having an ethylenically unsaturated bond such as vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene; ethylenically unsaturated carboxylic acids such as (meth) acrylamide and N-methylolacrylamide. Acid alkyl amides; Vinyl acetates, vinyl acetates, vinyl propionates, etc .; Acid anhydrides of ethylenically unsaturated dicarboxylic acids; Monoalkyl esters; Monoamides; Aminoethylacrylamide, dimethylaminomethylmethacrylamide, Methylaminopropylmethacrylamide Examples thereof include aminoalkylamides of ethylenically unsaturated carboxylic acids such as, and can be one or more selected from these.

1.1.4. Production Method of Polymer (A) The polymer (A) can be produced by a known synthesis method, but a solution polymerization method is particularly preferred. Moreover, as a polymerization form, you may use any of a batch type and a continuous type. In the case of using the solution polymerization method, as an example of a specific polymerization method, monomers such as a conjugated diene compound and an aromatic vinyl compound in an organic solvent are used as a polymerization initiator and a randomizer used as necessary. The method of superposing | polymerizing in presence is mentioned. For example, it can be produced according to known methods described in Japanese Patent No. 5402112, Japanese Patent No. 573216, International Publication No. 2014/014052, and the like. As the polymerization initiator, for example, a polymerization initiator described in JP-A-2006-274178 can be used.

The randomizer can be used for the purpose of adjusting the content (vinyl content) of vinyl bonds (1,2-bonds and 3,4-bonds). Randomizers include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di (tetrahydrofuryl) propane, 2- (2-ethoxyethoxy) -2-methylpropane, triethylamine, pyridine, N -Methylmorpholine, tetramethylethylenediamine and the like, and one or more selected from these can be used.

The iodine value of the polymer (A) is controlled by reducing the content of structural units derived from conjugated diene compounds and increasing the content of structural units derived from aromatic vinyl compounds and other structural units. can do. Further, the iodine value of the polymer may be controlled by hydrogenating a double bond in the polymer (hereinafter also referred to as “hydrogenation”) by a known method.

When the iodine value of the polymer (A) is controlled by hydrogenation, it can be arbitrarily selected by changing the amount of the catalyst, the hydrogen pressure during the reaction, and the reaction time, but the structural unit derived from the conjugated diene compound The hydrogenation rate is preferably in the range of 70 to 99%. The hydrogenation rate is a value obtained by measurement by ¹ H-NMR.

The polymer (A) is composed of an amino group, a carboxyl group, an oxazoline group, a group having a carbon-nitrogen double bond, a nitrogen-containing heterocyclic group, a phosphino group, a thiol group, and a hydrocarbyloxysilyl group at its end. It can also have one or more functional groups selected. By having such a functional group, for example, when applied to tire applications, the dispersibility of a reinforcing filler such as silica can be effectively improved, and the low hysteresis loss characteristic can be improved. In this specification, “amino group” means a primary amino group (—NH ₂ ), a secondary amino group (—NHR, where R is a hydrocarbon group), and a tertiary amino group (—NRR ′, where R , R ′ represents any one of hydrocarbon groups). The “carboxyl group” is a concept including not only —COOH but also —COOM (M is a monovalent metal ion) and an acetic anhydride segment. The amino group, carboxyl group, oxazoline group, phosphino group, thiol group and the like may be protected by a protecting group such as a trisubstituted hydrocarbylsilyl group.

1.1.5. Characteristics of polymer (A) <iodine value>
The iodine value of the polymer (A) is from 10 to 100, preferably from 10 to 80, and more preferably from 10 to 70. When the iodine value is in the above range, the cold flow phenomenon tends to be reduced. When the iodine value is not within the above range, the main chain contains many unsaturated bonds, resulting in a decrease in the entanglement density of the main chain, or a decrease in crystallinity due to the ethylene chain being broken by the unsaturated bond, etc. It is considered that the shape retention of the polymer (A) is lowered due to the influence of the above. In addition, when the iodine value is not within the above range, the heat resistance tends to be deteriorated, and it may not be able to withstand a processing step at a high temperature such as coextrusion. This is considered to be an effect of the unsaturated bond contained in the polymer (A) reacting at a high temperature and denatured.

The iodine value of the polymer (A) in the present invention can be measured according to the method described in “JIS K 0070: 1992”. Since the iodine value is a value that represents the amount of halogen that reacts with 100 g of the target substance in terms of grams of iodine, the unit of iodine value is “g / 100 g”. In this specification, for example, “the iodine value is 10 to 100” means “the iodine value is 10 to 100 g / 100 g”.

<Vinyl bond content>
The “vinyl bond content” in the present invention means a conjugated diene compound that is incorporated in the polymer (A) (before hydrogenation) in a 1, 2, or 1,4 bond bonding mode. It is the total ratio (on a mol% basis) of units incorporated in 1, 2 bonds and 3, 4 bonds among the derived structural units. The vinyl bond content of the polymer (A) is preferably 60 mol% or less, more preferably 50 mol% or less, and particularly preferably 40 mol% or less. When the vinyl bond content is in the above range, the mechanical strength and wear resistance of the obtained molded product tend to be further improved. The vinyl bond content (1,2 bond content and 3,4 bond content) can be calculated from the ¹ H-NMR spectrum.

The polymer (A) is particularly preferably a polymer containing a structural unit derived from butadiene and having a vinyl bond content of the structural unit derived from butadiene of 60 mol% or less. By making the vinyl bond content of the structural unit derived from butadiene 60 mol% or less, not only the mechanical strength and wear resistance of the resulting molded product become very good, but also grip characteristics when used for tires. Tend to be better.

<Weight average molecular weight (Mw)>
The weight average molecular weight (Mw) of the polymer (A) is preferably 1 × 10 ⁵ to 1 × 10 ⁶ , more preferably 1.5 × 10 ⁵ to 5 × 10 ⁵ , and 2 × 10. Particularly preferred is ⁵ to 4 × 10 ⁵ . When the weight average molecular weight (Mw) of the polymer (A) is in the above range, it is easy to obtain a molded article excellent in processability of the composition and excellent in high strength and wear resistance. The “weight average molecular weight” refers to a polystyrene equivalent weight average molecular weight measured by GPC (gel permeation chromatography).

<Average ethylene chain length>
The average ethylene chain length of the polymer (A) is 2 to 20, preferably 2 to 10, and more preferably 2 to 7. When the average ethylene chain length of the polymer (A) is in the above range, a crosslinked molded article having excellent mechanical strength and wear resistance can be obtained. When the average ethylene chain length is less than the above range, it indicates that more short chain branches and the like are introduced into the molecular chain, and crystallization by the ethylene chain is inhibited. There is a tendency to be inferior in wear resistance. On the other hand, when the average ethylene chain length exceeds the above range, workability and impact resistance may be deteriorated. The average ethylene chain length is also referred to as the average 1,4-butylene chain length. The number of 1,4-butylene units and the number of chains can be determined by ¹³ C-NMR and calculated from the following formula.
(Average ethylene chain length) = (1,4-butylene unit number) / (1,4-butylene chain number)

For example, the average ethylene chain length of the copolymer as shown in the following formula is 1,4 butylene units in total and the number of chains is 4, so the average ethylene chain length is 2.

As a method for adjusting the average ethylene chain length of the polymer (A), a known means can be adopted, and for example, it can be controlled by adding a potassium compound together with a polymerization initiator. By adding the potassium compound together with the polymerization initiator, the aromatic vinyl compound introduced into the polymer (A) can be randomly arranged or a single chain of the aromatic vinyl compound can be added. Thus, the average ethylene chain length of the polymer (A) can be controlled. Examples of the potassium compound include potassium alkoxide, potassium phenoxide, potassium salt of organic carboxylic acid, potassium salt of organic sulfonic acid, potassium salt of organic phosphorous acid, and the like.

1.2. Water (B)
The composition according to the present embodiment contains water (B). The content ratio of water (B) in the composition according to this embodiment is 0.05% by mass or more and 2.0% by mass or less, preferably 0.1% by mass or more and 1.5% by mass or less, More preferably, it is 0.2 mass% or more and 1.2 mass% or less. In the composition according to this embodiment, when the content of the polymer (A) is Ma (parts by mass) and the content of water (B) is Mb (parts by mass), Ma / Mb = 50 to 2000, preferably Ma / Mb = 67 to 1000, and more preferably Ma / Mb = 83 to 500.

When the content ratio of water (B) in the composition is within the above range, when the composition is molded, the moldability becomes excellent, and the cold flow of the molded product can be suppressed. If the content ratio of water (B) in the composition exceeds the above range, cold flow of the molded body may be easily generated, and water is heated to form bubbles, and bubbles are broken on the surface of the molded body. There is a possibility of failure (siriburst leak). When the content ratio of water (B) in the composition is less than the above range, the composition may be overdried and rubber may be burned, and the moldability of the composition tends to deteriorate.

The content ratio of water (B) in the composition is determined by heating the composition at a temperature and time suitable for the polymer to be used, using a dryer such as a dehumidifying dryer, a vacuum dryer, or a hot air dryer. Can be controlled. If the drying temperature is high and the drying time is long, the amount of water can be greatly reduced, but the composition may cause alteration such as scorch. Further, when the drying temperature is low and the drying time is short, the moisture content tends to increase. In any case, the content ratio of water (B) can be controlled by controlling the drying temperature and the drying time in this way.

2. A composition for a cross-linked molded body and a cross-linked molded body A composition for a cross-linked molded body is a polymer other than the crosslinking agent and the polymer (A), if necessary, in order to prepare a cross-linked molded body. , Fillers, anti-aging agents, zinc white, softeners, vulcanization accelerators, silane coupling agents, compatibilizers, vulcanization aids, processing aids, process oils, scorch prevention agents, etc. It refers to a composition containing various commonly used additives. The blending ratio of these additives can be appropriately selected within a range not impairing the effects of the present invention.

Examples of the crosslinking agent include sulfur, sulfur halides, organic peroxides, quinonedioximes, organic polyvalent amine compounds, alkylphenol resins having a methylol group, and one or more selected from these are used. can do. For example, when sulfur is used as the crosslinking agent, the amount is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymer (A).

Examples of the polymer other than the polymer (A) include butadiene rubber (BR, such as high cis BR having 90% or more of cis-1,4 bonds, BR containing syndiotactic-1,2-polybutadiene (SPB)), styrene butadiene, and the like. Examples include rubber (SBR), natural rubber (NR), isoprene rubber (IR), styrene isoprene copolymer rubber, butadiene isoprene copolymer rubber, and the like. One or more selected from these may be used. it can.

Examples of the filler include various reinforcing fillers such as carbon black, silica, clay, and calcium carbonate, and one or more selected from these can be used. Among these, carbon black, silica, or a combination of carbon black and silica is preferable. When carbon black or silica is used as the filler, the content of silica and / or carbon black is preferably 20 to 130 parts by mass with respect to 100 parts by mass of the polymer (A).

The vulcanization accelerator is not particularly limited, and examples thereof include sulfenamide-based, guanidine-based, thiuram-based, thiourea-based, thiazole-based, dithiocarbamic acid-based, xanthogenic acid-based and dithiophosphoric acid-based compounds, preferably 2 -Mercaptobenzothiazole, dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide N-oxyethylene-2-benzothiazole sulfenamide, N, N′-diisopropyl-2-benzothiazole sulfenamide, diphenylguanidine, diortolylguanidine, orthotolylbisguanidine and the like. The content of the vulcanization accelerator is usually 0.1 to 5 parts by mass, preferably 0.4 to 4 parts by mass with respect to 100 parts by mass of the polymer (A).

As the vulcanization aid or processing aid, stearic acid is usually used. The content ratio of the vulcanization aid and the processing aid is usually 0.5 to 5 parts by mass with respect to 100 parts by mass of the polymer (A).

The composition for crosslinked molded bodies can be produced by kneading the above components using a kneader such as an open kneader (for example, a roll) or a closed kneader (for example, a Banbury mixer).

The composition for a crosslinked molded body produced in this manner can be applied to various products as a crosslinked molded body by crosslinking (vulcanizing) by heating or the like after the molding process. Specifically, for example, tire applications such as tire treads, under treads, carcass, sidewalls, and bead parts; seal materials such as packings, gaskets, weather strips, O-rings; various vehicles such as automobiles, ships, aircraft, and railways Interior and exterior skin materials for building; building materials; anti-vibration rubbers for industrial machinery and equipment; various hoses and hose covers such as diaphragms, rolls, radiator hoses and air hoses; belts such as power transmission belts; Dust boots; Medical equipment materials; Fenders; Wire insulation materials; Other industrial products. In particular, a vulcanized molded body obtained by using the above-mentioned composition for a crosslinked molded body can be suitably used as a material for tire treads and sidewalls because it has high strength and excellent wear resistance.

The tire can be manufactured according to a conventional method. For example, in the case of a material for a sidewall, the composition for a cross-linked molded body is mixed with a kneader, and the sheet-like material is placed outside the carcass according to a conventional method and vulcanized and molded. Formed as sidewall rubber, a pneumatic tire is obtained.

3. EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present disclosure is not limited to these examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

3.1. Example 1
3.1.1. Production of Polymer A1 An autoclave reactor with an internal volume of 50 liters purged with nitrogen was charged with 25600 g of cyclohexane, 76.8 g of tetrahydrofuran, 160 g of styrene, and 2976 g of 1,3-butadiene. After the temperature of the reactor contents was adjusted to 45 ° C., a cyclohexane solution containing n-butyllithium (72.44 mmol) was added to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum temperature reached 85 ° C.
When the polymerization conversion rate reached 99%, 64 g of butadiene was added and further polymerized for 1 minute, and then 2.64 g of silicon tetrachloride was added and stirred for 15 minutes.
Next, the reaction solution is heated to 80 ° C. or higher and hydrogen is introduced into the reactor, and then [bis (η5-cyclopentadienyl) titanium (furfuryloxy) chloride] (“[chlorobis (2,4-cyclopenta Dienyl) titanium (IV) furfuryl alkoxide] ”) is added, and 1.32 g of diethylaluminum chloride and 1.28 g of n-butyllithium are added to maintain a hydrogen pressure of 0.7 MPa or more. Hydrogenation reaction was performed. After reaching a predetermined integrated hydrogen flow rate, the reaction solution was returned to room temperature and normal pressure and extracted from the reactor.
Next, the solvent of the reaction solution is removed by steam stripping (steam temperature: 190 ° C.) for 2 hours at a temperature of the liquid phase of the solvent removal tank: 95 ° C., and drying is performed by a hot roll adjusted to 110 ° C. Thus, a polymer A1 was obtained.

3.1.2. Evaluation method <Evaluation of styrene content>
The polymer A1 was dissolved in carbon tetrachloride, and the styrene content was calculated from the ¹ H-NMR spectrum at 500 MHz. The results are shown in Table 2.

<Evaluation of the amount of vinyl bonds (1, 2, and 3, 4 bonds)>
The amount of vinyl bonds (1, 2 bonds and 3, 4 bonds) was calculated from the ¹ H-NMR spectrum of polymer A1 at 500 MHz. The results are shown in Table 2.

<Evaluation of iodine value>
The iodine value of the polymer A1 was calculated according to the method described in “JIS K 0070: 1992”. The results are shown in Table 2.

<Evaluation of weight average molecular weight (Mw)>
It calculated | required in polystyrene conversion from the retention time corresponded to the vertex of the maximum peak of the GPC curve obtained using the gel permeation chromatography (GPC) of the following conditions. The results are shown in Table 2.
Column; two brand names “GMHXL” (manufactured by Tosoh Corporation) Column temperature: 40 ° C.
Mobile phase; tetrahydrofuran flow rate; 1.0 ml / min sample concentration; 10 mg / 20 ml

<Evaluation of average ethylene chain length>
^The number of 1,4-butylene units and the number of chains were determined by ¹³ C-NMR, and the average ethylene chain length was calculated from the following formula. The results are shown in Table 2.
(Average ethylene chain length) = (1,4-butylene unit number) / (1,4-butylene chain number)

3.1.3. Preparation and Evaluation of Composition The polymer (A1) obtained above was dried by changing the drying time with a hot roll to prepare the composition used in Example 1. The water content of the composition thus prepared was measured using an automatic heating and vaporization moisture measuring system (AQS-22320A manufactured by Hiranuma Sangyo Co., Ltd.) at a heating temperature of 150 ° C. and a nitrogen gas flow rate of 200 mL / min. .

<Cold flow>
The obtained composition was held at 70 ° C. and extruded from a 6.35 mm orifice under the condition of a pressure of 24.1 kPa. From 10 minutes after the start of extrusion, the extrusion amount (mg) of polymer A1 for 90 minutes was measured. The measurement results are shown as an index with Comparative Example 3 described later as 100, and the larger the value, the worse the shape stability and the more difficult the handling. The results are shown in Table 2.

3.1.4. Manufacture of a crosslinked molded body Using a plastmill with a temperature controller (internal volume: 250 ml), under the conditions of a filling rate of 72% and a rotation speed of 60 rpm, 100 parts by mass of the composition obtained above, silica (manufactured by Solvay, product) Name “ZEOSIL 1165MP”) 45 parts by mass, Silane coupling agent (product name “Si75” manufactured by Evonik Co., Ltd.) 3.6 parts by mass, stearic acid (manufactured by ADEKA) 2.0 parts by mass, anti-aging agent (Ouchi) First-stage kneading was performed by blending 1.0 part by mass of Shinsei Chemical Co., Ltd., trade name “NOCRACK 810NA”) and 3.0 parts by mass of zinc oxide. Next, after cooling to room temperature, 1.5 parts by mass of sulfur and 1.8 parts by mass of a vulcanization accelerator (trade name “Noxeller CZ” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.), a vulcanization accelerator (Ouchi Shinsei Chemical Industry) 1.5 parts by mass (trade name “Noxeller D”, manufactured by the company) was blended and kneaded in the second stage to produce a composition for a crosslinked molded body.

The obtained composition for a crosslinked molded article was molded and vulcanized with a vulcanizing press at 160 ° C. for a predetermined time to obtain a crosslinked molded article.

3.1.5. Evaluation of cross-linked molding <Tensile test>
Using the obtained cross-linked molded product, a tensile test was performed in accordance with JIS K6251. Here, dumbbell-shaped No. 3 was used as a test sample, and stress at break (TB) and elongation at break (EB) were measured at room temperature. The larger the values of TB and EB, the higher the breaking strength, indicating that the mechanical strength of the material is high and good. The results are shown in Table 2.

<Abrasion resistance test>
The obtained crosslinked molded article was used as a measurement sample, and measured using a DIN abrasion tester (manufactured by Toyo Seiki Co., Ltd.) according to JIS K6264-2: 2005 at a load of 10 N at 25 ° C. The measurement results are shown as an index with Comparative Example 3 being 100, and the larger the value, the better the wear resistance. The results are shown in Table 2.

3.2. Examples 2-4
Except having changed into the composition of Table 1, polymer A2, A3, and A4 were obtained by the same operation as Example 1, respectively. Each composition was prepared in the same manner as in Example 1 except that each of the polymers A2, A3, and A4 was used instead of the polymer A1, and the compositions shown in Table 2 were used. And evaluated. The results are shown in Table 2.

3.3. Example 5
An autoclave reactor with an internal volume of 50 liters purged with nitrogen was charged with 25600 g of cyclohexane, 76.8 g of tetrahydrofuran, 480 g of styrene, and 2656 g of 1,3-butadiene. After adjusting the temperature of the reactor contents to 45 ° C., a cyclohexane solution containing n-butyllithium (37.97 mmol) was added to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum temperature reached 85 ° C.
When the polymerization conversion rate reaches 99%, 64 g of butadiene is added, and further polymerized for 1 minute, and then a cyclohexane solution containing 6.3 g of N, N-dimethylaminopropylmethyldiethoxysilane is added and reacted for 15 minutes. I let you.
Next, the reaction solution was brought to 80 ° C. or higher to introduce hydrogen into the system, and then [bis (η5-cyclopentadienyl) titanium (furfuryloxy) chloride] 2.65 g, diethylaluminum chloride 3.99 g, and 1.12 g of n-butyllithium was added, and a hydrogenation reaction was performed while maintaining a hydrogen pressure of 0.7 MPa or more. After reaching the predetermined hydrogen integrated flow rate, the reaction solution was returned to room temperature and normal pressure and extracted from the reaction vessel.
Then, the solvent of the reaction solution was removed by the same operation as in Example 1, and the polymer A5 was obtained by drying with a hot roll adjusted to 110 ° C.
A composition was prepared in the same manner as in Example 1 except that the polymer A5 was used in place of the polymer A1, and a crosslinked molded body was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2.

3.4. Comparative Example 1
A polymer P1 was obtained by the same operation as in Example 1 except that the polymerization formulation was changed as shown in Table 1. Except for using the polymer P1 instead of the polymer A1, a composition was prepared in the same manner as in Example 1 so as to have the composition described in Table 2, and a crosslinked molded product was produced and evaluated. The results are shown in Table 2.

3.5. Comparative Example 2
Polymerization reaction and desolvation were carried out by the same polymerization formulation and operation as in Example 4 except that the hydrogenation reaction was not carried out to obtain a polymer P2. Except for using the polymer P2 instead of the polymer A1, a composition was prepared in the same manner as in Example 1 so as to have the composition described in Table 2, and a crosslinked molded product was produced and evaluated. The results are shown in Table 2.

3.6. Comparative Example 3
A polymer P3 was obtained by the same polymerization prescription and operation as in Example 4 except that the integrated hydrogen flow rate in the reaction was reduced. Except for using the polymer P3 in place of the polymer A1, a composition was prepared in the same manner as in Example 1 so as to have the composition described in Table 2, and a crosslinked molded product was produced and evaluated. The results are shown in Table 2.

3.7. Comparative Example 4
A polymer P4 was obtained by the same polymerization formulation and operation as in Example 4 except that the temperature of the hot roll for drying was 95 ° C. Except for using the polymer P4 in place of the polymer A1, a composition was prepared in the same manner as in Example 1 so as to have the composition described in Table 2, and a crosslinked molded product was produced and evaluated. The results are shown in Table 2.

3.8. Evaluation results Table 1 shows the polymerization prescription of each polymer. Table 2 shows the composition of each composition and each evaluation result.

As is apparent from Table 2, a polymer containing a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, having an average ethylene chain length of 2 to 20 and an iodine value of 10 to 100 And the composition which has a specific amount of water turned out that a cold flow can be suppressed effectively. Moreover, it turned out that the mechanical strength and abrasion resistance of material improve the crosslinked molded object manufactured from the composition for crosslinked molded objects containing this composition.

Claims (5)

A polymer (A) having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound;
Water (B),
Containing
The polymer (A) has an average ethylene chain length of 2 to 20,
The iodine value of the polymer (A) is 10 to 100,
A composition in which Ma / Mb = 50 to 2000 when the content of the polymer (A) is Ma (parts by mass) and the content of the water (B) is Mb (parts by mass). The composition according to claim 1, wherein the polymer (A) is a polymer containing butadiene as the conjugated diene compound and having a vinyl bond content of a structural unit derived from the butadiene of 60 mol% or less. One or more functional groups selected from the group consisting of an amino group, a group having a carbon-nitrogen double bond, a nitrogen-containing heterocyclic group, a phosphino group, a thiol group, and a hydrocarbyloxysilyl group at the terminal of the polymer (A). A composition according to claim 1 or claim 2 having A cross-linked molded article produced using the composition according to any one of claims 1 to 3. A tire using the crosslinked molded article according to claim 4 as at least a dread or sidewall material.