JP4921625B2 - Modified diene rubber composition - Google Patents

Description

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実施例１〜５および比較例１〜２
基本配合組成として表２に示す組成を用いた。
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６０ｃｃのバンバリータイプのプラストミルを用いて表３に示す主要配合組成の組成物（のこりの成分については表２参照）を混練りし（加硫剤はロールを用いて混練りした）、１５０℃で３０分間プレス加硫して各種ゴム組成物を調製し、引張強度（Ｍ３００）、ランボーン摩耗指数、転がり抵抗指数およびウエットスキッド指数を測定した。結果を表３に示す。
【００６８】
【表２】

【００６９】
【表３】

【００７０】
【発明の効果】
本発明によれば、高シス−１，４構造を有するゴムを、アミノ基とアルコキシ基とを含有する有機ケイ素化合物により変性した変性ジエン系ゴムからなる転がり摩擦抵抗特性（燃費特性）、ウエットスキッド特性やウエットオンアイス特性（雪氷上性能）などのグリップ特性および耐摩擦性に優れた変性ジエン系ゴム組成物を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rolling friction resistance characteristic (fuel consumption characteristic), a wet skid characteristic, and a modified diene rubber obtained by modifying a rubber having a high cis-1,4 structure with an organosilicon compound containing an amino group and an alkoxy group. The present invention relates to a modified diene rubber composition having excellent grip characteristics such as wet-on-ice characteristics (performance on snow and ice) and friction resistance.
[0002]
[Prior art]
Conventionally, polybutadiene rubber (BR), natural rubber (NR), styrene-butadiene rubber (SBR) and the like have been used as rubber for automobile tires.
[0003]
In recent years, demands for lower fuel consumption of automobiles and driving safety requirements on snow and on ice during rainy weather have increased. As a tire tread rubber for automobiles, rolling resistance at high temperatures is low, and road grip on rainy weather, snow and ice is low. The development of large materials has been desired.
[0004]
However, a rubber having a large rebound resilience (low rolling resistance) such as BR has a low wet skid resistance, and a rubber having a small rebound resilience (high rolling resistance) such as SBR has a high wet skid resistance. Yes, these are contradictory to each other. Therefore, how to maintain these characteristic values in a well-balanced manner and improve both characteristic values is an issue.
[0005]
Conventionally, as a means for solving such a problem, many methods for chemically modifying a low cis conjugated diene rubber obtained using a lithium catalyst with a modifier have been proposed.
[0006]
For example, a method of modifying low cis BR with a benzophenone compound has been proposed in Japanese Patent Application Laid-Open Nos. 58-162604 and 59-117514, and the rolling resistance of automobile tires is low and the wet skid resistance is high. The improvement effect is recognized.
[0007]
Further, a method for producing a modified diene rubber by reacting a low cis BR produced with a lithium catalyst with a silicon or tin compound and a specific aminosilane compound is disclosed in JP-A-1-284503, It is described that the impact resilience is high, the JIS hardness at low temperature is low, and the processability is excellent.
[0008]
However, the low cis BR has insufficient wear resistance and impact resilience compared to the high cis BR, and this problem cannot be solved even by modification.
[0009]
In addition, the low cis BR obtained with the lithium catalyst is in a state where the end of the polymer is activated (living state) and can be easily reacted with the modifier, but with a cobalt, titanium, or nickel catalyst. The produced high cis BR has poor reactivity and is difficult to react with the denaturing agent. For this reason, so far, there have not been many proposals for modification methods relating to rubber having a high cis-1,4 structure.
[0010]
On the other hand, in recent years, many methods using silica as a low heat-generating filler have been reported from the viewpoint of reinforcing properties, but silica tends to aggregate particles due to hydrogen bonding of silanol groups which are surface functional groups. Therefore, various silane coupling agents have been developed to solve these problems. However, this silane coupling agent is still insufficient to increase the workability and processability of the rubber composition, despite the cost.
[0011]
[Problems to be solved by the invention]
An object of the present invention is to provide a modified diene rubber composition excellent in gripping characteristics such as rolling friction resistance characteristics (fuel consumption characteristics), wet skid characteristics and wet on ice characteristics (performance on snow and ice), and friction resistance. To do.
[0012]
[Means for Solving the Problems]
As a result of intensive studies to improve the above problems, the present inventors are composed of a modified diene rubber obtained by modifying a rubber having a high cis-1,4 structure with a silicon compound containing an amino group and an alkoxy group. To find that the modified diene rubber composition has rolling friction resistance characteristics (fuel consumption characteristics), grip characteristics such as wet skid characteristics and wet on ice characteristics (performance on snow and ice) and friction resistance, and completes the present invention. It came.
[0013]
That is, the present invention
(A) a cobalt compound,
(B) A diene rubber obtained by polymerizing a diolefin having a conjugated double bond using a catalyst composed of an organoaluminum compound and (C) water, and immediately after polymerization , an amino group and an alkoxy group, which are modifiers Obtained by modification using an organosilicon compound containing
More than 80% of the repeating units are cis-1,4 structures,
The weight average molecular weight (Mw) by GPC is 20,000 to 1,000,000,
With respect to 100 parts by weight of a rubber component containing 10 to 80% by weight of a modified diene rubber having a nitrogen content attributable to the modifier of 10 ppm or more,
Modified diene rubber composition comprising 5 to 100 parts by weight of silica and 0 to 10% by weight of silane coupling agent based on silica weight (Claim 1)
About.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The modified diene rubber used in the present invention was obtained by polymerizing a diolefin having a conjugated double bond using a catalyst comprising (A) a cobalt compound, (B) an organoaluminum compound, and (C) water. 80% or more of a diene rubber having a cis-1,4 structure is modified with an organosilicon compound containing an amino group and an alkoxy group as a modifier.
[0015]
Any diolefin having a conjugated double bond can be used without particular limitation as long as it is generally used as a raw material monomer for a diene rubber. Specifically, polybutadiene rubber, styrene-butadiene rubber, styrene-isoprene-butadiene rubber and the like are preferable as the diene rubber, and 1,3-butadiene, isoprene and the like are preferably used. These may be used alone or in combination of two or more. Styrene is preferably used as a copolymerization component.
[0016]
The polymerization of the diolefin is generally performed in a polymerization solvent using the catalyst. The polymerization conditions are not particularly limited, and may be general conditions known to those skilled in the art.
[0017]
Examples of the polymerization solvent include inert aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons. Specifically, benzene, toluene, xylene, n-hexane, n-pentane, n-heptane, n-octane, cyclohexane, methylcyclohexane, decalin and the like. These may be used alone or in combination of two or more.
[0018]
As the cobalt compound which is the component (A) of the catalyst used in the present invention, organic carboxylate cobalt, organic cobalt sulfonate, cobalt β-diketone complex compound, cobalt halide tertiary amine complex compound and the like are used. It is done. Specifically, cobalt naphthenate, cobalt octenoate, cobalt malonate, cobalt octoate, cobalt stearate, cobalt acetate, cobalt benzoate, cobalt oxalate, cobalt salicylate, cobalt dodecylbenzenesulfonate, bis (ethyl acetoacetate) Examples include cobalt, bis (acetylacetonato) cobalt, tris (acetylacetonato) cobalt, and dichloro-bis (pyridine) cobalt. These may be used alone or in combination of two or more. Among these, cobalt organic carboxylates, particularly cobalt naphthenate, cobalt octenoate, and cobalt octoate are preferred.
[0019]
As the organoaluminum compound which is the component (B) of the catalyst used in the present invention, the general formula AlR ₂ X (where R represents an alkyl group having 1 to 6 carbon atoms such as an ethyl group, an isobutyl group and a hexyl group). The two alkyl groups may be the same or different, and X represents a halogen atom such as a chlorine atom, a bromine atom or an iodine atom). Specific examples include diethylaluminum monochloride, diisobutylaluminum monochloride, dihexylaluminum monochloride, diethylaluminum monobromide and the like. These may be used alone or in combination of two or more. Of these, diethylaluminum monochloride and diisobutylaluminum monochloride are preferably used.
[0020]
The amount of the cobalt compound used is preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻³ mol with respect to 1 mol of the diolefin.
[0021]
The amount of the organoaluminum compound used is preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol per 1 mol of the diolefin.
[0022]
The amount of water used is preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol per 1 mol of the diolefin. If the amount of water added is less than 1 × 10 ⁻⁵ mol, the effect of improving the catalytic activity is small, and if it exceeds 1 × 10 ⁻¹ mol, the activity decreases.
[0023]
The order of addition of the catalyst components is not particularly limited, but it is desirable to add them after the organoaluminum compound and water are reacted in advance.
[0024]
The diene rubber is modified using an organosilicon compound containing an amino group and an alkoxy group, but is preferably modified immediately after production. Here, “immediately after production” means that the modification is continuously performed in a polymerization system in which diolefin polymerization is performed to obtain a diene rubber. In this case, modification may be performed by directly adding a modifier to the polymerization system obtained from the diene rubber. The temperature for the modification is preferably in the range of 0 to 100 ° C, more preferably in the range of room temperature to 70 ° C. If the temperature is too low, the modification reaction is difficult to proceed, and if the temperature is too high, the diene rubber gels, which is not preferable. There is no particular limitation on the modification reaction time, but usually it is preferably in the range of 0.5 to 6 hours. If the modification time is too short, the reaction does not proceed sufficiently, and if the time is too long, the diene rubber may be gelled.
[0025]
The modifying agent is not particularly limited as long as it is an organosilicon compound containing an amino group and an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group in the molecule. Specifically, 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropylmethyldisilane Ethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethylbutoxysilane, 3-aminopropylmethyldibutoxysilane, 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, 3- (2-aminoethylamino) Propyl) dimethoxyethylsilane, 3- (2-aminoethylaminopropyl) dimethoxypropylsilane, 3- (2-aminoethylaminopropyl) dimethoxybutylsilane, 3- (2-aminoethylaminopropyl) Examples include diethoxymethylsilane, 3- (2-aminoethylaminopropyl) trimethoxysilane, 3- (2-aminoethylaminopropyl) triethoxysilane, and 3- (2-aminoethylaminopropyl) tributoxysilane. . These may be used alone or in combination of two or more. Of these, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, and 3- (2-aminoethylaminopropyl) trimethoxysilane are particularly preferably used.
[0026]
The amount of the modifying agent used is preferably 0.01 to 150 mmol, more preferably 1.0 to 100 mmol, with respect to 100 g of the diene rubber. When the amount of the modifier used is small, the amount of silicon compound containing amino groups and alkoxysilyl groups introduced into the modified diene rubber (modified amount) decreases, and a satisfactory modification effect is unlikely to appear. On the other hand, if the amount of the modifier used is too large, unreacted modifier remains in the modified diene rubber, and it takes time to remove it, resulting in waste of the modifier, and a significant improvement in physical properties. Hard to appear.
[0027]
The modifier is considered to be bonded to the main chain double bond and / or 1,2-vinyl group and / or terminal.
[0028]
The modified diene rubber preferably has a cis-1,4 structure with 80% or more, more preferably 85% or more of the repeating units.
[0029]
The modified diene rubber may have a weight average molecular weight (Mw) of 20,000 to 1,000,000, more preferably 100,000 to 1,000,000 by GPC (gel permeation method). preferable. When the weight average molecular weight is less than 20,000, the strength becomes low, and when it exceeds 1,000,000, the workability is lowered. Moreover, it is preferable that molecular weight distribution (Mw / number average molecular weight (Mn)) is 1-3. Furthermore, for the same reason, the Mooney viscosity (ML _{1 + 4} , 100 ° C.) is preferably 20 to 80.
[0030]
It can be confirmed that the diene rubber is chemically modified by measuring the nitrogen content of the modified diene rubber from which the unreacted modifier has been sufficiently removed by the Kjeldahl method described later. The nitrogen content is an index indicating how much the diene rubber and the modifier have reacted. Nitrogen atoms can be easily and reliably analyzed even in a small amount, and the modification rate of the modified diene rubber can be evaluated based on the nitrogen content.
[0031]
The nitrogen content of the modified diene rubber is preferably 10 ppm or more, more preferably 10 to 5,000 ppm. When the nitrogen content is less than 10 ppm, the effect of modifying the diene rubber is reduced, and when it exceeds 5,000 ppm, the gelation of the rubber is promoted during kneading and the processability tends to be impaired.
[0032]
The modified diene rubbers may be used alone or in combination of two or more. Further, the modified diene rubber is used by blending with other synthetic rubbers or natural rubbers. From the viewpoint of sufficiently obtaining the effect of using the modified diene rubber, the modified diene rubber in all rubber components is used. The amount is 10 to 80% by weight, preferably 15 to 75% by weight. If necessary, the oil may be extended with process oil.
[0033]
Examples of the other synthetic rubber include unmodified diene rubbers such as styrene-butadiene rubber, polyisoprene rubber, styrene-isoprene-butadiene rubber, ethylene-propylene-diene rubber, chloroprene rubber, and acrylonitrile-butadiene rubber. It is done.
[0034]
There is no restriction | limiting in particular in the silica used for the rubber composition of this invention, Although a dry process silica (anhydrous silicic acid), wet process silica (hydrous silicic acid), etc. are mention | raise | lifted, a wet process silica is preferable. A nitrogen adsorption specific surface area (N ₂ SA) of 50 to 300 m ² / g is preferable. When the nitrogen adsorption specific surface area (N ₂ SA) of silica is less than 50 m ² / g, the dispersibility improving effect and the reinforcing effect tend to be small, and when it exceeds 300 m ² / g, the dispersibility is poor and the heat generation is increased. Tend to. Preferable examples of the wet process silica include Ultrasil VN3 (trade name) manufactured by Degussa and Nipsil VN3 AQ (trade name) manufactured by Nippon Silica Co., Ltd.
[0035]
The amount of silica is 5 to 100 parts by weight, preferably 10 to 85 parts by weight, and more preferably 20 to 65 parts by weight with respect to 100 parts by weight of the rubber component. If the blending amount of silica is less than 5 parts by weight, the reinforcing effect is small, and if it exceeds 100 parts by weight, workability decreases, which is not preferable. From the viewpoint of low heat build-up and workability, the amount of silica is preferably 20 to 65 parts by weight.
[0036]
The silane coupling agent used in the rubber composition of the present invention has an action of strengthening the bond between silica and the rubber component and improving the wear resistance. As the silane coupling agent, any silane coupling agent conventionally used in combination with silica may be used. Specifically, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) Tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethyl Thiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, Examples include 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, and 3-trimethoxysilylpropyl methacrylate monosulfide. Bis (3-triethoxysilylpropyl) tetrasulfide and the like are preferable from the viewpoint of both the effect of adding a coupling agent and cost.
[0037]
The compounding amount of the silane coupling agent is preferably 0 to 10% by weight, more preferably 0.5 to 8% by weight, based on the silica weight. If the amount of the silane coupling agent exceeds 10% by weight, the coupling effect cannot be obtained although the cost increases, which is not preferable. In view of the dispersibility of silica and the coupling effect, the amount of the silane coupling agent is preferably 0.5 to 8% by weight.
[0038]
Furthermore, the rubber composition of the present invention contains carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 30 to 200 m ² / g and a compressed dibutyl phthalate oil absorption (24M4DBP oil absorption) of 30 to 150 ml / 100 g. You may go out. When the nitrogen adsorption specific surface area (N ₂ SA) and the compressed dibutyl phthalate oil absorption (24M4DBP oil absorption) are smaller than the respective lower limit values, the dispersibility improving effect and the reinforcing effect are small, and when the upper limit value is exceeded, Dispersibility is poor and heat generation tends to increase. Examples of carbon black that can be used include HAF, ISAF, and SAF.
[0039]
In addition to the rubber component, silica, silane coupling agent, and carbon black, the rubber composition of the present invention includes a softening agent, an anti-aging agent, a vulcanizing agent, a vulcanization accelerator, and a vulcanization as necessary. A rubber composition that can be appropriately mixed with a compounding agent used in a normal rubber industry such as an acceleration aid, and that requires mechanical properties and wear resistance of tires, hoses, belts, and other various industrial products. As applied.
[0040]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, these do not limit the objective of this invention. First, various chemicals used in the following examples and comparative examples will be described below.
[0041]
(Description of various chemicals)
Natural rubber: NR 7
Silica: Ultrasil VN3 manufactured by Degussa (N ₂ SA: 180 m ² / g)
Silane coupling agent: Si69 (chemical name: bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by Degussa
Vulcanization accelerator A: Noxeller NS (chemical name: Nt-butyl-2-benzothiazyl sulfenamide) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Vulcanization accelerator B: Noxeller D (chemical name: N, N'-diphenyl guanidine) manufactured by Ouchi Shinsei Chemical Co., Ltd.
In addition, the cis-1,4 structural amount, the weight average molecular weight and the molecular weight distribution, the nitrogen content, and the Mooney viscosity of the rubber component were measured by the following methods.
[0042]
(Cis-1,4 structure amount)
The cis-1,4 structure amount was calculated by measuring the microstructure of the rubber using a 0.4% by weight carbon disulfide solution by infrared absorption spectrum analysis.
[0043]
(Weight average molecular weight and molecular weight distribution)
Gel permeation (permeation) chromatography (made by Tosoh Corporation, GPC) was performed at a temperature of 40 ° C. using polystyrene as a standard substance and polystyrene as a solvent, and the weight was determined using a calibration curve obtained from the obtained molecular weight distribution curve. Average molecular weight (Mw) and number average molecular weight (Mn) were determined. The molecular weight distribution was calculated as the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn).
[0044]
(Nitrogen content)
According to JIS K0102, it quantified by the Kjeldahl method.
[0045]
(Mooney viscosity (ML _{1 + 4} , 100 ° C))
According to JIS K6300, after preheating at 100 ° C. for 1 minute, the rubber Mooney viscosity (ML _{1 + 4} , 100 ° C.) measured for 4 minutes was displayed.
[0046]
Further, in the following Examples and Comparative Examples, the tensile strength (M300), the Lambourn wear index, the rolling resistance index, and the wet skid index of the rubber composition were measured by the following methods.
[0047]
(Tensile test)
It was measured according to JIS K6301 and indicated by a modulus of 300%.
[0048]
(Rolling resistance index)
Using a viscoelastic spectrometer VES (manufactured by Iwamoto Seisakusho Co., Ltd.), tan δ of each formulation was measured under the measurement conditions of a temperature of 70 ° C., an initial strain of 10%, and a dynamic strain of 2%. The index was expressed by the following formula. The larger the index, the better the rolling resistance characteristics.
Rolling resistance index = (tan δ of Comparative Example 1 / tan δ of each formulation) × 100
[0049]
(Lambourn wear index)
Using a Lambourn Abrasion Tester, measure the Lambourn wear amount under the measurement conditions of a temperature of 20 ° C., a slip rate of 20%, and a test time of 5 minutes, and calculate the volume loss of each formulation. The index was expressed by the following formula. It shows that abrasion resistance is excellent, so that an index | exponent is large.
Abrasion index = (loss amount of Comparative Example 1 / loss amount of each formulation) × 100
[0050]
(Wet skid index)
The measurement was performed according to the method of ASTM E303-83 using a portable skid tester manufactured by Stanley Co., Ltd., and displayed as an index using the following formula. The larger the index, the better the wet skid performance.
[0051]
Wet skid index = (Numerical value of each formulation / Numerical value of Comparative Example 1) × 100
Next, the rubber component will be described.
[0052]
Production Example 1
Into a 1.5 L stainless steel autoclave with sufficient nitrogen substitution, 1 L of a benzene-C ₄ fraction mixed solution containing 27.9 wt% of 1,3-butadiene (26.9 wt% of benzene and cis-2-butene g of the containing C ₄ fraction 45.2% by weight as a main component), then distilled water 2 mmol, diethylaluminum monochloride (n- hexane solution) was added to 2.9 mmol, was performed stirring. Next, 4.24 mmol of cyclooctadiene was added, and the temperature increase of the autoclave was started. After the internal temperature reaches 58.5 ° C., the polymerization of 1,3-butadiene was started by injecting 0.0087 mmol of cobalt octenoate (benzene solution) as the main catalyst, and at 60 ° C. for 30 minutes. A polymerization reaction was performed.
[0053]
After completion of the polymerization reaction, the unreacted gas was discharged out of the system, and 500 ml of toluene was added to make a toluene solution of unmodified polybutadiene, and then 500 ml of methanol was further added and the contents were sufficiently stirred for 10 minutes. After the stirring was stopped, the entire content of the autoclave was transferred to a separate container, and unmodified polybutadiene was filtered and separated. This separated polymer was dissolved in 800 ml of toluene, and then 800 ml of methanol was added to precipitate the polymer, followed by filtration and separation three times. Next, Irganox 1010 (tetrakis (methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate) methane 0.11 phr as an antioxidant for the unmodified polymer. As an anti-aging agent, 0.45 phr of trisnonylphenyl phosphite was added and kneaded, and vacuum-dried at 100 ° C. for 1.5 hours to produce unmodified polybutadiene (hereinafter referred to as polymer 1).
[0054]
Using the obtained polymer 1, cis-1,4 structural amount, weight average molecular weight and molecular weight distribution, nitrogen content and Mooney viscosity were measured. The results are shown in Table 1.
[0055]
Production Example 2
Into a 1.5 L stainless steel autoclave with sufficient nitrogen substitution, 1 L of a benzene-C ₄ fraction mixed solution containing 27.9 wt% of 1,3-butadiene (26.9 wt% of benzene and cis-2-butene And 45.2 wt% of a C ₄ fraction containing as a main component), 2 mmol of distilled water and 2.9 mmol of diethylaluminum monochloride (n-hexane solution) were added and stirred. Next, 4.24 mmol of cyclooctadiene was added, and the temperature increase of the autoclave was started. After the internal temperature reaches 58.5 ° C., the polymerization of 1,3-butadiene was started by injecting 0.0087 mmol of cobalt octenoate (benzene solution) as the main catalyst, and at 60 ° C. for 30 minutes. A polymerization reaction was performed.
[0056]
Immediately after completion of the polymerization reaction, 1.78 mmol of 3- (2-aminoethylaminopropyl) trimethoxysilane was added as a modifier to 100 g of rubber at the same temperature, and the modification reaction was performed for 120 minutes.
[0057]
After completion of the modification reaction, the unreacted gas was discharged out of the system, and 500 ml of toluene was added to make a toluene solution of the modified polybutadiene, and then 500 ml of methanol was further added and the contents were sufficiently stirred for 10 minutes. After the stirring was stopped, the entire content of the autoclave was transferred to a separate container, and the modified polybutadiene was filtered and separated. The separated polymer was dissolved in 800 ml of toluene, and then 800 ml of methanol was added to precipitate the polymer, followed by filtration and separation three times. Next, for the modified polymer, Irganox 1010 (tetrakis- (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate) methane 0.11 phr as an antioxidant, Modified polybutadiene (hereinafter referred to as polymer 2) was produced by adding 0.45 phr of trisnonylphenyl phosphite as an anti-aging agent and kneading and drying in vacuo at 100 ° C. for 1.5 hours.
[0058]
Using the obtained polymer 2, cis-1,4 structural amount, weight average molecular weight and molecular weight distribution, nitrogen content and Mooney viscosity were measured. The results are shown in Table 1.
[0059]
Production Example 3
Modified polybutadiene (hereinafter referred to as polymer 3) was produced in the same manner as polymer 2 except that the modifier was changed to 3- (2-aminoethylaminopropyl) dimethoxymethylsilane.
[0060]
Using the obtained polymer 3, cis-1,4 structural amount, weight average molecular weight and molecular weight distribution, nitrogen content and Mooney viscosity were measured. The results are shown in Table 1.
[0061]
Production Example 4
Modified polybutadiene (hereinafter referred to as polymer 4) was produced in the same manner as polymer 2 except that the modifier was changed to 3-aminopropyltrimethoxysilane.
[0062]
Using the obtained polymer 4, cis-1,4 structure amount, weight average molecular weight and molecular weight distribution, nitrogen content and Mooney viscosity were measured. The results are shown in Table 1.
[0063]
Production Example 5
Modified polybutadiene (hereinafter referred to as polymer 5) was produced in the same manner as polymer 2, except that the amount of 3- (2-aminoethylaminopropyl) trimethoxysilane as a modifier was changed to 0.95 mmol. .
[0064]
Using the obtained polymer 5, cis-1,4 structure amount, weight average molecular weight and molecular weight distribution, nitrogen content and Mooney viscosity were measured. The results are shown in Table 1.
[0065]
[Table 1]

[0066]
Examples 1-5 and Comparative Examples 1-2
The composition shown in Table 2 was used as the basic blend composition.
[0067]
Using a 60 cc Banbury type plast mill, knead the composition of the main composition shown in Table 3 (see Table 2 for the ingredients of the residue) (the vulcanizing agent was kneaded using a roll) at 150 ° C. Various rubber compositions were prepared by press vulcanization for 30 minutes, and the tensile strength (M300), the Lambourn wear index, the rolling resistance index, and the wet skid index were measured. The results are shown in Table 3.
[0068]
[Table 2]

[0069]
[Table 3]

[0070]
【Effect of the invention】
According to the present invention, rolling friction resistance characteristics (fuel consumption characteristics) comprising a modified diene rubber obtained by modifying a rubber having a high cis-1,4 structure with an organosilicon compound containing an amino group and an alkoxy group, wet skid It is possible to obtain a modified diene rubber composition excellent in grip characteristics such as characteristics and wet-on-ice characteristics (performance on snow and ice) and friction resistance.

Claims (1)

(A) a cobalt compound,
(B) A diene rubber obtained by polymerizing a diolefin having a conjugated double bond using a catalyst composed of an organoaluminum compound and (C) water, and immediately after polymerization , an amino group and an alkoxy group, which are modifiers Obtained by modification using an organosilicon compound containing
More than 80% of the repeating units are cis-1,4 structures,
The weight average molecular weight (Mw) by GPC is 20,000 to 1,000,000,
With respect to 100 parts by weight of a rubber component containing 10 to 80% by weight of a modified diene rubber having a nitrogen content attributable to the modifier of 10 ppm or more,
A modified diene rubber composition comprising 5 to 100 parts by weight of silica and 0 to 10% by weight of a silane coupling agent based on the weight of silica.