JP2018035250A - Manufacturing method of natural rubber-white filler composite and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a natural rubber-white filler composite less in odor specific to natural rubber, and excellent in rubber physical properties such as low fuel consumption by adding the same to a rubber composition and a tire having a tire member constituted by the rubber composition containing the composite.SOLUTION: There are provided a manufacturing method of a natural rubber-white filler composite including a mixing process for mixing a natural rubber latex and a white filler A, a high purification process for conducting high purification treatment on a mixture obtained in the mixing process and a solidification drying process for solidification drying the high purified article obtained in the high purification process, and a tire having a tire member constituted by a rubber composition containing the natural rubber-white filler composite manufactured by the manufacturing method.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a natural rubber-white filler composite, and a tire including a tire member composed of a rubber composition containing the composite.

  In recent years, rubber compositions for tires are required to have various rubber properties such as low fuel consumption. In particular, rubber compositions for treads are resistant to wet grip and abrasion, and rubber compositions for sidewalls are resistant to rubber. Flex crack growth and handling stability are required.

  Natural rubber is an indispensable raw material for rubber compositions for tires because it has excellent rubber properties and does not depend on petroleum resources. Is difficult. Furthermore, there is a problem that natural rubber produced by the conventional method has a characteristic odor.

  For example, Patent Document 1 discloses a technique that improves the dispersibility of the filler by improving processability by removing impurities from natural rubber as much as possible, and further improves the fuel efficiency. However, there is still room for improvement in wet grip performance, and low fuel consumption is not sufficient.

  Although it is known that aluminum hydroxide is effective in improving wet grip properties (for example, Patent Document 2), there is still room for improvement in wear resistance.

  Further, in the cited document 3, a rubber composition containing a composite obtained by washing an agglomerate of a blended latex in which a modified natural rubber latex and fine particle silica are mixed is used to reduce fuel consumption and wear resistance. And a technology that can achieve both fracture performance. However, there is still room for improvement in terms of fuel efficiency.

Japanese Patent No. 3294901 Japanese Patent No. 4163863 JP 2012-107099 A

  The present invention relates to a method for producing a natural rubber-white filler composite that has less odor peculiar to natural rubber and is excellent in rubber physical properties such as low fuel consumption when blended with a rubber composition, and a rubber composition containing the composite It aims at providing a tire provided with the tire member comprised by the thing.

  As a result of intensive studies, the inventors of the present invention have made natural rubber a white rubber-white filler composite obtained by mixing a natural rubber latex with a white filler and then subjecting the rubber to a high-purification treatment, followed by coagulation and drying. As a result, the present inventors have found that the above problems can be solved, and have succeeded in completing the present invention through further studies.

  That is, the present invention includes a mixing step of mixing natural rubber latex and white filler A, a purification step of purifying the mixture obtained in the mixing step, and a purified product obtained in the purification step. The present invention relates to a method for producing a natural rubber-white filler composite, which includes a coagulation drying step of coagulation and drying.

  The white filler A is preferably aluminum hydroxide having an average particle diameter of less than 1.5 μm.

  The white filler A is preferably silica.

  The present invention relates to a tire including a tire member composed of a rubber composition containing the natural rubber-white filler composite produced by the production method.

  The present invention is obtained by a mixing step of mixing natural rubber latex and aluminum hydroxide having an average particle size of less than 1.5 μm, a high purification step of purifying the mixture obtained in the mixing step, and a high purification step. And a rubber composition containing a natural rubber-aluminum hydroxide composite obtained by a method for producing a natural rubber-white filler composite including a coagulation drying step for coagulation and drying. The present invention relates to a tire provided with a tread.

  The present invention is obtained by a mixing step of mixing natural rubber latex and aluminum hydroxide having an average particle size of less than 1.5 μm, a high purification step of purifying the mixture obtained in the mixing step, and a high purification step. A rubber composition containing a natural rubber-aluminum hydroxide composite obtained by a method for producing a natural rubber-white filler composite including a coagulation drying step for coagulating and drying the highly purified product, and a styrene butadiene rubber. The present invention relates to a tire including a tread that is configured.

  The present invention includes a mixing step of mixing natural rubber latex and silica, a purification step of purifying the mixture obtained in the mixing step, and a highly purified product obtained in the purification step coagulated and dried. The present invention relates to a tire provided with a tread composed of a natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite including a coagulation drying step, and a rubber composition containing butadiene rubber.

  The present invention includes a mixing step of mixing natural rubber latex and silica, a purification step of purifying the mixture obtained in the mixing step, and a highly purified product obtained in the purification step coagulated and dried. The present invention relates to a tire provided with a tread composed of a natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite including a coagulation drying step, and a rubber composition containing styrene-butadiene rubber.

  The present invention also includes a mixing step of mixing natural rubber latex and silica, a high-purification step for purifying the mixture obtained in the mixing step, and a coagulation of the high-purity product obtained in the high-purification step. The present invention relates to a tire provided with a sidewall composed of a rubber composition containing a natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite including a coagulation drying step for drying, and a butadiene rubber.

  The average particle diameter of the aluminum hydroxide is preferably 0.7 μm or less.

The silica preferably has a BET specific surface area of 50 m ² / g or more.

  The white filler A content in the composite is preferably 5 to 80 parts by mass with respect to 100 parts by mass of the rubber component in the composite.

  The purification process in the purification process is preferably a saponification process.

  It is preferable that the complex has a pH of 2 to 7.

  The rubber composition preferably further contains silica and / or carbon black.

  The butadiene rubber is preferably a butadiene rubber having a functional group that interacts with silica.

  The butadiene rubber is preferably butadiene rubber having a cis content of 90% by mass or more.

  The styrene butadiene rubber is preferably a styrene butadiene rubber having a functional group that interacts with silica.

  The mixing step of mixing the natural rubber latex and the white filler A of the present invention, the purification step for purifying the mixture obtained in the mixing step, and the solidification of the purified product obtained in the purification step According to the method for producing a natural rubber-white filler composite including a drying and coagulating drying step, the composite has a low odor peculiar to natural rubber, and a rubber composition containing the composite has low fuel consumption. A composite that can improve the physical properties of rubber and the like can be obtained.

  In particular, by using the rubber composition containing the composite as a tread, it is possible to provide a tire that has a low odor peculiar to natural rubber and that is excellent in fuel efficiency, wet grip and wear resistance. . Further, by using the rubber composition containing the composite as a tire for a sidewall, there is provided a tire having a low odor peculiar to natural rubber, excellent in fuel efficiency, flex crack growth resistance and steering stability. be able to.

  The method for producing a natural rubber-white filler composite according to the present invention comprises a mixing step of mixing natural rubber latex and white filler A, a high purification step of purifying the mixture obtained in the mixing step, and a high purity. It is a manufacturing method including the coagulation drying process which coagulate | solidifies and dries the highly purified product obtained at the conversion process. The present invention is characterized in that a white filler is added in the mixing step. In addition, you may add a white filler in another process.

  The mixing step is a step of adding and mixing the white filler A to natural rubber latex. Natural rubber latex is collected as a sap of a natural rubber tree such as Hevea, and the sap contains various impurities such as water, proteins, lipids, and inorganic salts in addition to rubber. It is believed that. In the present invention, since the white filler is mixed with the solution-like natural rubber latex in the mixing step, the white filler can be sufficiently dispersed. Furthermore, since the white filler A adsorbs the impurities of the natural rubber latex, the impurities can be effectively removed in the subsequent purification step.

  As natural rubber latex, raw latex (field latex) collected by tapping Hevea tree, concentrated latex obtained by concentrating raw latex by centrifugation or creaming method (refined latex, high ammonia latex with ammonia added by conventional method) And zinc oxide, TMTD (tetramethylthiuram disulfide) and ammonia stabilized LATZ latex). Among these, it is preferable to use field latex because it is easy to achieve high purity by pH control.

  The rubber component (solid rubber content) in the natural rubber latex is preferably 5 to 40% by mass, more preferably 10 to 30% by mass because of the excellent balance of stirring efficiency, white filler dispersibility, and volumetric efficiency. preferable.

  In this specification, the white filler A indicates a white filler contained in a natural rubber-white filler composite. Examples of the white filler A include aluminum hydroxide, silica, magnesium hydroxide, calcium carbonate, and magnesium carbonate. These white fillers A may be used independently and may use 2 or more types together. Especially, it is preferable to use a natural rubber-aluminum hydroxide composite using aluminum hydroxide from the viewpoint of wet grip properties, and a natural rubber-silica composite using silica from the viewpoint of wear resistance. Is preferred.

  The addition amount of the white filler A in the mixing step is preferably 5% by mass or more, and more preferably 10% by mass or more of the total amount of the white filler A, from the viewpoints of impurity adsorption effect and low fuel consumption. Moreover, although the addition amount of the white filler A in a mixing process can also be made into 100 mass% of the white filler A whole quantity, 90 mass% or less is preferable from a dispersible viewpoint to a rubber composition.

  In the case of using aluminum hydroxide as the white filler A, the average particle diameter of aluminum hydroxide is preferably 0.20 μm or more, and more preferably 0.25 μm or more from the viewpoint of wear resistance and workability. The average particle diameter of aluminum hydroxide used in the mixing step is preferably less than 1.5 μm, more preferably 1.0 μm or less, even more preferably 0.7 μm or less, from the viewpoint of wear resistance and wet grip properties. Most preferably, it is 6 μm or less. In addition, the average particle diameter of the aluminum hydroxide in this specification is a number average particle diameter, and is a value measured with a transmission electron microscope.

When aluminum hydroxide is used as the white filler A, the BET specific surface area of aluminum hydroxide is preferably 5 m ² / g or more, and more preferably 8 m ² / g or more. Further, BET specific surface area of aluminum hydroxide is preferably 80 m ² / g or less, more preferably 70m ² / g or less, 60 m ² / g or less is more preferred. By setting the BET specific surface area of aluminum hydroxide within the above range, excellent wear resistance and wet grip properties can be obtained. In addition, the BET specific surface area of the aluminum hydroxide in this specification is a value measured by BET method according to ASTM D3037-81.

  When silica is used as the white filler A, the average particle diameter of silica is preferably 1 nm or more, and more preferably 5 nm or more from the viewpoint of processability. Further, the average particle diameter of silica is preferably 30 nm or less, more preferably 25 nm or less, and further preferably 20 nm or less, from the viewpoints of wear resistance and wet grip properties. In addition, the average particle diameter of the silica in this specification is a number average particle diameter, and is a value measured by a transmission electron microscope.

The BET specific surface area of the silica used in the mixing step when the composite using silica as the white filler A is contained in the tread rubber composition is preferably 50 m ² / g or more, more preferably 80 m ² / g or more, 120 m ² / g or more is more preferable, 150 m ² / g or more is more preferable, and 160 m ² / g or more is most preferable. Further, BET specific surface area of the silica is preferably not more than 500 meters ² / g, more preferably at most 300m ² / g. By setting the BET specific surface area of the silica used in the mixing step within the above range, excellent wear resistance and wet grip properties can be obtained. Moreover, the BET specific surface area of the silica used in the mixing step when the composite using silica as the white filler A is contained in the rubber composition for the sidewall is because the balance between the low fuel consumption and the rubber strength is excellent. 50 to 250 m ² / g is preferable, and 80 to 180 m ² / g is preferable. In addition, the BET specific surface area of the silica in this specification is a value measured by BET method according to ASTM D3037-81.

  It does not specifically limit as a mixing method, It can be set as a general mixing method, such as stirring with a blender mill. The white filler A may be added to the natural rubber latex as it is, but it is preferably added as a slurry solution dispersed in water from the viewpoint of dispersibility.

  The purification step is a step of obtaining a highly purified product by subjecting the mixture obtained in the mixing step to a purification treatment. Here, high purification means removal of impurities such as phospholipids and proteins other than natural polyisoprenoid components contained in natural rubber latex. Natural rubber particles contained in natural rubber latex have a structure in which an isoprenoid component is coated with an impurity component. By removing impurities on the surface of natural rubber particles, the structure of the isoprenoid component changes and the interaction with the compounding agent also changes, resulting in the effects of reducing energy loss and improving durability, resulting in excellent high It is speculated that purified natural rubber (UPNR) can be obtained. Moreover, the odor peculiar to natural rubber can be reduced by removing impurities from the natural rubber latex. Furthermore, in the production method of the present invention, since the white filler is present in the natural rubber latex by the mixing step, the white filler adsorbs impurities, and the purification can be performed more efficiently. it can.

  For the purification treatment, known methods such as saponification treatment, enzyme treatment, and mechanical treatment such as ultrasonic wave and centrifugation are used without limitation. Among them, production efficiency, cost, dispersibility of white filler, etc. In view of the above, saponification treatment is preferable.

  Examples of the saponification method include methods described in JP2010-138359A and JP2010-174169A. Specifically, it can be carried out by adding a basic compound and, if necessary, a surfactant to natural rubber latex and allowing it to stand at a predetermined temperature for a certain period of time. Also good.

  The basic compound is not particularly limited, but a basic inorganic compound is preferable from the viewpoint of removal performance of proteins and the like. Examples of basic inorganic compounds include metal hydroxides such as alkali metal hydroxides and alkaline earth metal hydroxides; metal carbonates such as alkali metal carbonates and alkaline earth metal carbonates; alkali metal hydrogen carbonates and the like Metal phosphates such as alkali metal phosphates; metal acetates such as alkali metal acetates; metal hydrides such as alkali metal hydrides; ammonia and the like.

  Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. Examples of the alkaline earth metal hydroxide include magnesium hydroxide, calcium hydroxide, and barium hydroxide. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate. Examples of the alkaline earth metal carbonate include magnesium carbonate, calcium carbonate, barium carbonate and the like. Examples of the alkali metal hydrogen carbonate include lithium hydrogen carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. Examples of the alkali metal phosphate include sodium phosphate and sodium hydrogen phosphate. Examples of the alkali metal acetate include sodium acetate and potassium acetate. Examples of the alkali metal hydride include sodium hydride and potassium hydride. Of these, metal hydroxides, metal carbonates, metal hydrogen carbonates, metal phosphates, and ammonia are preferable from the viewpoint of saponification efficiency and ease of treatment. Sodium hydroxide, an alkali metal hydroxide, water More preferred is potassium oxide. These basic compounds may be used alone or in combination of two or more.

  The surfactant is not particularly limited, and examples thereof include known anionic surfactants such as polyoxyethylene alkyl ether sulfates, nonionic surfactants, and amphoteric surfactants, but do not coagulate rubber. Anionic surfactants such as polyoxyethylene alkyl ether sulfates are preferred because they can be saponified satisfactorily. In addition, what is necessary is just to set suitably the addition amount of a basic compound and surfactant, the temperature and time of a saponification process in a saponification process.

  When the high-purification treatment is a saponification treatment, a basic compound is added to the mixture in the saponification treatment, so the white filler in the mixture is considered to be partially soluble in water under an alkaline solution. Therefore, the saponified complex is not subjected to saponification treatment, that is, the basic compound is not added, and the white color in the complex is higher than the complex obtained by coagulating and drying the neutral mixture. It is estimated that the dispersibility of the filler is excellent, and the wear resistance and fuel efficiency are improved. In particular, when silica is used as the white filler A, silica partially in a colloidal or sol form under an alkaline solution is not subjected to a saponification treatment as a high-purification treatment, and is gelled under a neutral solution. It is thought that the purification can be performed more efficiently because impurities of the natural rubber latex are adsorbed more than the silica that has become.

  The coagulation drying process is a process for obtaining a natural rubber-white filler composite by coagulating the purified product obtained in the purification process and then drying the coagulated product. The complex obtained in the coagulation drying process has the structure of the isoprenoid component of the natural rubber having a polar group because impurities on the surface of the natural rubber particles are removed in the previous purification step, and the polar group and The interaction with the white filler is strong. Therefore, it is considered that the rubber composition containing the composite is excellent in rubber physical properties.

  The coagulation method is not particularly limited, and examples thereof include a method of adjusting the pH to 4 to 7 by adding an acid such as formic acid, acetic acid or sulfuric acid, and further adding a polymer flocculant and stirring if necessary. It is done. By coagulating, the rubber content of the highly purified product can be agglomerated to obtain a coagulated rubber.

  Further, in the coagulation and drying step, impurities of natural rubber latex can be more efficiently removed, and from the reason that coagulated rubber can be easily obtained, white filler A may be further added, and an acid is added to adjust pH. It is preferable to add to the coagulated rubber by adding the mixture after stirring and stirring. The amount of white filler A added in the coagulation drying step when white filler A is added in the coagulation drying step is preferably 0 to 40% by mass, more preferably 1 to 20% by mass of the total amount of white filler A. The white filler A added in the step can be the same as the white filler A added in the mixing step.

  The drying method is not particularly limited. For example, the drying method is performed using a normal dryer such as a trolley dryer, a vacuum dryer, an air dryer, a drum dryer, or the like used in the drying process of a normal natural rubber production method such as TSR. it can.

  Drying is preferably performed after washing the obtained coagulated rubber. The cleaning method is not particularly limited as long as impurities contained in the entire rubber can be sufficiently removed. For example, the rubber component is diluted with water and washed, and then centrifuged. For example, a method of floating and discharging only the aqueous phase and taking out the rubber component may be mentioned. Further, when the obtained solidified rubber is treated with a basic compound after washing, the impurities trapped in the rubber at the time of solidification can be redissolved and washed, and strongly adhered to the solidified rubber. Impurities can also be removed.

  2-7 are preferable, as for pH of the natural rubber-white filler complex based on this invention, 3-6 are more preferable, and 4-6 are more preferable. By making the pH of the composite within the above range, deterioration of heat aging resistance can be prevented, and the performance balance of fuel efficiency, heat aging resistance and processability can be remarkably improved, and the odor peculiar to natural rubber is further reduced. There is an effect that can be done. In addition, the pH of the composite is cut into a size of 2 mm square on each side, immersed in distilled water, extracted at 90 ° C. for 30 minutes while irradiating with microwaves, and the immersion water is extracted using a pH meter. It is a measured value, specifically, measured by the method described in the examples described later.

  The content of the white filler A is preferably 5 parts by mass or more with respect to 100 parts by mass of the rubber component in the composite because the odor peculiar to natural rubber can be reduced and the fuel efficiency is improved. More than mass part is more preferable. Further, the content of the white filler A is preferably 80 parts by mass or less, and more preferably 60 parts by mass or less, because a natural rubber-white filler complex can be easily produced. In addition, the rubber component in the said composite body shows the rubber solid content of the natural rubber latex added at the mixing process.

  The natural rubber-white filler composite obtained by the production method of the present invention can be blended in a rubber composition. By making a rubber composition containing the composite, rubber properties such as low fuel consumption can be obtained. An excellent rubber composition can be obtained.

  The rubber composition containing the natural rubber-white filler composite obtained by the production method of the present invention includes, in addition to the composite, a rubber component other than the rubber component contained in the composite (other rubber components), A white filler other than the white filler A, a coupling agent, carbon black, a plasticizer, zinc oxide, stearic acid, various anti-aging agents, a wax, a vulcanizing agent, a vulcanization accelerator, and the like can be appropriately blended.

  Examples of the other rubber components include non-modified natural rubber (NR), highly purified natural rubber (UPNR), epoxidized natural rubber (ENR), isoprene rubber (IR), butadiene rubber (BR), and styrene butadiene. Examples thereof include rubber (SBR), styrene isoprene rubber (SIR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR) and the like. Especially, it is preferable to use BR from the reason that it is excellent in abrasion resistance, a low temperature characteristic, and bending crack growth resistance, and it is preferable to use SBR from the reason that it is excellent in wet grip property.

  As BR, high cis BR having a cis content of 90% by mass or more is preferable from the viewpoint that excellent wear resistance can be obtained. The cis content of BR is preferably 90% by mass or more, and more preferably 95% by mass or more. In addition, the cis content in this specification is a value measured by an infrared absorption spectrum analysis method.

  In addition, as BR, the interaction with the filler becomes stronger and the fuel efficiency is excellent, so that modified BR (modified with a modified terminal BR and / or main chain, tin, silicon compound, etc.) ( From the point of reaction with silica, modified BR having a terminal and / or main chain modified with a functional group that interacts with silica, particularly silyl, is preferable. A modified BR having at least one selected from the group consisting of a group, an amino group, an amide group, a hydroxyl group, and an epoxy group is preferred.

  In the case of containing BR, the content in the rubber component is preferably 5% by mass or more, more preferably 8% by mass or more, and further preferably 10% by mass or more from the viewpoint of wear resistance. Moreover, 80 mass% or less is preferable from a viewpoint of workability, and, as for content in the rubber component of BR, 75 mass% or less is more preferable. In addition, content in the rubber component in this specification is content in the total amount of the rubber component in the composite and the other rubber components.

  The SBR is not particularly limited. For example, unmodified emulsion polymerized styrene butadiene rubber (E-SBR), solution polymerized styrene butadiene rubber (S-SBR), and modified emulsion polymerized styrene butadiene rubber (modified E-SBR) obtained by modifying them. And modified solution-polymerized styrene butadiene rubber (modified S-SBR). The SBR includes an oil-extended type in which flexibility is adjusted by adding an extending oil, and a non-oil-extended type in which no extending oil is added, either of which can be used.

  Examples of the modified SBR include those having a terminal and / or main chain modified with a functional group that interacts with silica, and those that are coupled with tin, silicon, or the like. Among these modified SBRs, modified SBRs whose terminals and / or main chain are modified by a functional group that interacts with silica are obtained from the viewpoint of reaction with silica and excellent fuel economy. Particularly preferred is a modified S-SBR having at least one selected from the group consisting of a silyl group, an amino group, an amide group, a hydroxyl group, and an epoxy group.

The styrene content of SBR is preferably 5% by mass or more, and more preferably 10% by mass or more, because sufficient grip properties and rubber strength can be obtained. Further, the styrene content of SBR is preferably 60% by mass or less, and more preferably 50% by mass or less from the viewpoint of low fuel consumption. In addition, the styrene content of SBR in the present specification is a value calculated by ¹ H-NMR measurement.

The vinyl bond amount of SBR is preferably 10% by mass or more, and more preferably 15% by mass or more, because sufficient grip properties and rubber strength can be obtained. The vinyl bond amount of SBR is preferably 65% by mass or less and more preferably 60% by mass or less from the viewpoint of low fuel consumption. In addition, the vinyl bond amount of SBR in this specification shows the vinyl bond amount of a butadiene part, and is a value computed by < ¹ > H-NMR measurement.

  When the SBR is contained, the content in the rubber component is preferably 40% by mass or more, and more preferably 50% by mass or more from the viewpoint of grip properties. Further, the content of the SBR in the rubber component is preferably 90% by mass or less, and more preferably 80% by mass or less, because there is a possibility that excellent fuel efficiency due to UPNR contained in the composite may not be obtained. . When oil-extended SBR is used as SBR, the content of SBR itself as a solid content contained in the oil-extended SBR is set as the content in the rubber component.

  The rubber composition further contains a white filler in addition to the composite, thereby improving wear resistance, wet grip properties, and performance on ice. Further, the white filler contained is a white filler B other than the white filler A. The white filler B can be arbitrarily selected from those conventionally used in the rubber industry, for example, mica such as silica, calcium carbonate, sericite, aluminum hydroxide, magnesium hydroxide, alumina, clay. , Talc, titanium oxide and the like. Of these, silica is preferably used from the viewpoint of low fuel consumption. In addition, it is preferable not to contain aluminum hydroxide as the white filler B from a viewpoint of abrasion resistance. The white filler B may be the same white filler as the white filler A, but is clearly classified from the viewpoint of content.

  From the viewpoint of dispersibility, the content of the white filler B with respect to 100 parts by mass of the rubber component in the case of containing the white filler B is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and more preferably 15 parts by mass or more. Further preferred. Further, the content of the white filler B is preferably 150 parts by mass or less, more preferably 100 parts by mass or less, and still more preferably 80 parts by mass or less from the viewpoint of improving processability and fuel economy. In addition, the rubber component which comprises 100 mass parts of rubber components in this specification is the rubber component in the said composite, and the said other rubber component.

  The silica when silica is used as the white filler B is not particularly limited, and examples thereof include dry method silica (anhydrous silicic acid), wet method silica (anhydrous silicic acid) and the like. Of these, wet-process silica is preferred because it has many silanol groups.

In the case of using silica as the white filler B, the BET specific surface area of silica is preferably 40 m ² / g or more, more preferably 50 m ² / g or more, and 100 m ² / g or more from the viewpoint of fracture strength after vulcanization. More preferably, 150 m ² / g or more is particularly preferable. Further, BET specific surface area of the silica, from the viewpoint of fuel economy and workability, is preferably from 500 meters ² / g, more preferably at most 300m ² / g. In addition, the BET specific surface area of the silica in this specification is a value measured by BET method according to ASTM D3037-81.

  In the case of using silica as the white filler B, the content of silica with respect to 100 parts by mass of the rubber component is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 30 parts by mass or more from the viewpoint of low heat generation. Preferably, 40 parts by mass or more is most preferable. Further, the content of silica is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and further preferably 130 parts by mass or less, because silica is sufficiently dispersed and excellent in workability. In addition, 5-80 mass parts is preferable and, as for content of the silica with respect to 100 mass parts of rubber components in case silica is contained as a white filler B in the rubber composition for sidewalls, 10-50 mass parts is more preferable. In addition, when using a silica as the white filler A in a composite_body | complex, let the content of the said silica be the total content of the silica of the white filler A, and the silica of the white filler B.

  When the rubber composition contains silica, it is preferable to contain a silane coupling agent together with silica. Examples of silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, and bis (3-trimethoxy Silylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2-triethoxysilylethyl) ) Trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide Sulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (2- Trimethoxysilylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetra Sulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilyl group Sulfide system such as pyrbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-mercaptopropyltrimethoxysilane , 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-octanoylthio-1-propyltriethoxysilane, etc., mercapto series, vinyltriethoxysilane, vinyltrimethoxysilane, etc. Vinyl-based, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxy Amino, such as silane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane , Glycidoxy type such as γ-glycidoxypropylmethyldimethoxysilane, nitro type such as 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane And chloro-based compounds such as 2-chloroethyltrimethoxysilane and 2-chloroethyltriethoxysilane. These may be used alone or in combination of two or more. Product names include Si69, Si75, Si363 manufactured by Degussa, NXT, NXT-LV, NXTULV, NXT-Z manufactured by Momentive. Of these, mercapto-based NXT, sulfide-based Si69, Si75, and the like are preferable because they have a good balance of workability, fuel efficiency, and wear resistance.

  The content with respect to 100 parts by mass of silica in the case of containing a silane coupling agent is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, because silica can be dispersed well. 2.5 parts by mass or more is more preferable. Further, the content of the silane coupling agent is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and more preferably 10 parts by mass or less because the scorch time is appropriate and the processability in kneading and extrusion is excellent. Further preferred. Moreover, even if it contains the silane coupling agent exceeding 20 mass parts, the dispersibility effect of a silica does not improve, but there exists a tendency for cost to increase unnecessarily. The silica constituting 100 parts by mass of silica is silica of white filler A and silica of white filler B.

  The carbon black is not particularly limited, and GPF, FEF, HAF, ISAF, SAF and the like can be used alone or in combination of two or more. In order to increase the ratio of non-petroleum resources, it is preferable to use carbon black that uses renewable biological materials. By containing carbon black, excellent weather resistance and antistatic properties can be obtained.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 70 m ² / g or more, more preferably 100 m ² / g or more, from the viewpoint of reinforcing properties. Also, N ₂ SA of carbon black is in terms of fuel economy, is preferably not more than 200 meters ² / g, more preferably at most 180 m ² / g. In addition, N ₂ SA of carbon black in this specification is a value obtained by the A method of JIS K6217.

  In the case of containing carbon black, the content with respect to 100 parts by mass of the rubber component is preferably 1 part by mass or more, and more preferably 2 parts by mass or more. Further, the content of carbon black is preferably 150 parts by mass or less, more preferably 100 parts by mass or less, further preferably 50 parts by mass or less, and most preferably 30 parts by mass or less. By setting the carbon black content within the above range, good fuel economy and weather resistance can be obtained.

  Examples of the plasticizer include oil, liquid polymer, and liquid resin. These plasticizers may be used alone or in combination of two or more. However, it is more preferable to use oil as a plasticizer from the viewpoint of excellent balance between cost and workability. By containing a plasticizer, excellent processability and rubber strength can be obtained.

  When the plasticizer is contained, the content relative to 100 parts by mass of the rubber component is 1 part by mass or more and preferably 3 parts by mass or more from the viewpoint of processability. Moreover, content of a plasticizer is 40 mass parts or less from a viewpoint of abrasion resistance and steering stability, and 20 mass parts or less are preferable. In addition, the oil content contained in oil-extended rubber and insoluble sulfur is included in the content of the plasticizer in the present specification.

  Examples of the oil include process oil, vegetable oil, and animal oil. Examples of the process oil include paraffinic process oil, naphthenic process oil, and aromatic process oil. Moreover, the process oil (low PCA content process oil) with a low content of a polycyclic aromatic (polycyclic aromatic compound: PCA) compound is mentioned as an environmental measure. Low PCA content process oils include: Treated Distillate Aromatic Extract (TDAE), which is a re-extracted oil aromatic process oil, aroma substitute oil that is a mixed oil of asphalt and naphthenic oil, mild extraction solvates, MES ), And heavy naphthenic oils. Vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice bran oil, sesame oil, olive oil, sunflower Oil, palm kernel oil, cocoon oil, jojoba oil, macadamia nut oil, safflower oil, tung oil and the like. Examples of animal fats include oleyl alcohol, fish oil, and beef tallow. Among these, process oil is preferable from the viewpoint of processability, and it is preferable to use process oil having a low PCA content in terms of environmental measures.

  In the case of containing oil, the content with respect to 100 parts by mass of the rubber component is preferably 2 parts by mass or more, and more preferably 5 parts by mass or more from the viewpoint of processability. In addition, the oil content is preferably 40 parts by mass or less from the viewpoint of the load in the process.

  As a method for producing the rubber composition, a known method can be used. For example, the rubber composition can be produced by kneading the components with a Banbury mixer, a kneader, an open roll, etc., and then vulcanizing.

  Since the rubber composition is excellent in rubber physical properties such as fuel efficiency, it is preferably used for tire members, particularly treads and sidewalls.

  In particular, the rubber composition containing the natural rubber-aluminum hydroxide composite, in which the white filler A is aluminum hydroxide having an average particle size of less than 1.5 μm, and BR has excellent wet grip properties and wear resistance. It is preferable to use it for a tread. A natural rubber-aluminum hydroxide composite in which white filler A is aluminum hydroxide having an average particle size of 1.5 μm and a rubber composition containing SBR are excellent in wet grip and wear resistance, and are therefore used for treads. It is preferable. Since the natural rubber-silica composite whose white filler A is silica and the rubber composition containing BR are excellent in wet grip properties and wear resistance, they are preferably used for treads. Since the natural rubber-silica composite whose white filler A is silica and the rubber composition containing SBR are excellent in wet grip properties and wear resistance, they are preferably used for treads. In particular, a natural rubber-silica composite in which the white filler A is silica and a rubber composition containing BR are preferably used for a tire sidewall because they have excellent resistance to flex crack growth and steering stability. .

  The tire of the present invention can be produced by an ordinary method using the rubber composition containing the natural rubber-white filler composite obtained by the production method of the present invention. That is, the rubber composition is extruded together with a tire member at an unvulcanized stage, bonded together with other tire members on a tire molding machine, and molded by a normal method, thereby obtaining an unvulcanized tire. And the unvulcanized tire is heated and pressed in a vulcanizer to produce the tire of the present invention.

  The tire of the present invention can be suitably used as a tire for passenger cars, and can be applied to both winter tires and summer tires. In particular, a tread composed of a rubber composition containing BR is used. Since the provided tire is excellent in low-temperature characteristics and on-ice performance, it is preferably applied to winter tires such as studless tires. In addition, the winter tire in this specification is a tire excellent in performance on ice and snow and low temperature characteristics, and the summer tire indicates a tire other than the winter tire.

  The present invention will be described based on examples, but the present invention is not limited to the examples.

Hereinafter, various chemicals used in Examples and Comparative Examples are shown together.
Composite 1: Natural rubber-hydroxylated Al1 composite composite prepared in Production Example 1 below: Natural rubber-hydroxylated Al2 composite composite produced in Production Example 2 below: produced in Comparative Production Example 1 below Natural rubber-hydroxylated Al1 composite UPNR1: UPNR produced in Comparative Production Example 2 below
Composite 4: Natural rubber-silica 1 composite composite produced in Production Example 3 below: Natural rubber-silica 2 composite composite produced in Production Example 4 below: Natural rubber produced in Comparative Production Example 3 below -Silica 1 composite UPNR2: UPNR produced in Comparative Production Example 4 below
Complex 7: Natural rubber-hydroxylated Al1 complex composite 8 produced in the following Production Example 5: Natural rubber-hydroxylated Al2 complex complex 9 produced in the following Production Example 6: produced in Comparative Production Example 5 below Natural rubber-hydroxylated Al1 composite composite 10: Natural rubber-hydroxylated Al1 composite composite 11 produced in Comparative Production Example 6 below: Natural rubber-silica 1 composite composite 12 produced in Production Example 7 below: Natural rubber-silica 2 composite composite 13 produced in Production Example 8 below: Natural rubber-silica 1 composite composite produced in Comparative Production Example 7 below: Natural rubber-silica 1 produced in Comparative Production Example 8 below Composite complex 15: Natural rubber-hydroxylated Al1 composite complex 16 produced in the following Production Example 9: Natural rubber-hydroxylated Al2 composite complex 17 produced in the following Production Example 10: In Comparative Production Example 9 below Made natural rubber-water Al1 composite complex 18: natural rubber-hydroxylated Al1 composite complex 19 produced in Comparative Production Example 10 below: natural rubber-silica 1 composite composite 20 produced in Production Example 11 below: Production Example 12 below Natural rubber-silica 2 composite composite 21 prepared in the above: natural rubber-silica 1 composite composite 22 prepared in the following Comparative Production Example 11: natural rubber-silica 1 composite composite produced in the following Comparative Production Example 12 23: Natural rubber-hydroxylated Al1-silica 1 composite composite produced in the following Production Example 13 24: Natural rubber-hydroxylated Al1-silica 1 composite composite produced in the following Comparative Production Example 25: The following Production Example 14: natural rubber-silica 3 composite composite 26 produced in 14: natural rubber-silica 3 composite composite 27 produced in Comparative Production Example 14 below: natural rubber-silica 3 produced in Comparative Production Example 15 below Combined NR: TSR
SBR: Modified S-SBR prepared in the following modified SBR production example (terminal-modified S-SBR having a hydroxyl group, a glycidyl group, and an alkoxysilyl group, Mw: 717,000, styrene content: 28% by mass, vinyl bond amount: 60% by mass )
BR: Modified BR prepared in the following modified BR production example (terminal-modified BR having a hydroxyl group, a glycidyl group, and an alkoxysilyl group, Mw: 350,000, cis content: 97% by mass, vinyl bond amount: 1.1% by mass)
Aluminum hydroxide 1: Heidilite H-43 manufactured by Showa Denko KK (average particle size: 0.75 μm, BET: 10 m ² / g)
Silica 1: Ultrasil VN3 manufactured by Degussa (average particle size: 17.8 nm, BET: 175 m ² / g)
Silica 3: Zeosil 1115MP manufactured by Rhodia (average particle size: 23.2 nm, BET: 100 m ² / g)
Carbon black: Diamond Black I (ISAF, N ₂ SA: 114 m ² / g) manufactured by Mitsubishi Chemical Corporation
Silane coupling agent: NXT manufactured by Momentive
Stearic acid: Beads manufactured by NOF Co., Ltd. Beaded stearic acid zinc oxide 1: Zinc oxide 2 types manufactured by Mitsui Kinzoku Mining Co., Ltd. 2: Zinc oxide 3 types manufactured by Hakusui Tech Co., Ltd. Antioxidant: Ouchi Nocrack 6C (N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine, 6PPD) manufactured by Shinsei Chemical Industry Co., Ltd.
Wax: Ozoace 0355 manufactured by Nippon Seiwa Co., Ltd.
Oil 1: Diana Process NH-70S (naphthenic process oil) manufactured by Idemitsu Kosan Co., Ltd.
Oil 2: VIVETEC 500 (TDAE oil) manufactured by H & R
Sulfur 1: Seimi Sulfur (insoluble sulfur, oil content: 10%) manufactured by Nihon Kiboshi Kogyo Co., Ltd.
Sulfur 2: Powdered sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd .: Noxeller NS (Nt-butyl-2-benzothiazylsulfenamide, TBBS) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

Complex Production Examples Hereinafter, various chemicals used in Production Examples 1 to 14 and Comparative Production Examples 1 to 15 are collectively shown.
Aluminum hydroxide 1: Heidilite H-43 manufactured by Showa Denko KK (average particle size: 0.75 μm, BET: 10 m ² / g)
Aluminum hydroxide 2: Dry pulverized product of aluminum hydroxide 1 (average particle size: 0.3 μm, BET: 45 m ² / g)
Silica 1: Ultrasil VN3 manufactured by Degussa (average particle size: 17.8 nm, BET: 175 m ² / g)
Silica 2: Zeosil Premium 200MP manufactured by Rhodia (average particle size: 14 nm, BET: 220 m ² / g)
Silica 3: Zeosil 1115MP manufactured by Rhodia (average particle size: 23.2 nm, BET: 100 m ² / g)
Field Latex: Field Latex Emar E-27C (surfactant) obtained from Muhiba Latex Co., Ltd .: Emar E-27C (Polyoxyethylene lauryl ether sodium sulfate, 27% by mass of active ingredient) manufactured by Kao Corporation
NaOH: NaOH manufactured by Wako Pure Chemical Industries, Ltd.
Wingstay L (anti-aging agent): WINGSTAY L (compound obtained by butylating the condensate of ρ-cresol and dicyclopentadiene) manufactured by ELIOKEM
Emulvin W (surfactant): Emalvin W (aromatic polyglycol ether) manufactured by LANXESS
Tamol NN9104 (surfactant): Tamol NN9104 manufactured by BASF (Naphthalenesulfonic acid / formaldehyde sodium salt)
Van gel B (surfactant): Van gel B (magnesium aluminum silicate hydrate) manufactured by Vanderbilt
Cationic polymer flocculant: Aron Flock C312 manufactured by MT Aqua Polymer Co., Ltd.

<Preparation of anti-aging agent dispersion>
462.5 g of water was mixed with 12.5 g of Emulvin W, 12.5 g of Tamol NN9104, 12.5 g of Van gel B, and 500 g of Wingstay L (total of 1000 g) for 16 hours by a ball mill to prepare an antioxidant dispersion.

Production Example 1: Complex 1
1000 g of water was added to 55 g of aluminum hydroxide 1 and stirred vigorously for 20 minutes to obtain a slurry solution. After adjusting the solid content concentration (DRC) of the field latex to 30% (w / v), the whole amount of the aluminum hydroxide slurry solution was added to 1000 g of the latex, and vigorously stirred at room temperature for 30 minutes. Then, 25 g of 10% Emar E-27C aqueous solution and 60 g of 25% NaOH aqueous solution were added, and saponification treatment was performed at room temperature for 24 hours. Next, 6 g of the anti-aging agent dispersion was added and stirred for 2 hours. Next, formic acid was added with stirring to adjust the pH to 5.6, then a cationic polymer flocculant was added, stirred for 2 minutes, and 5 g of aluminum hydroxide 1 was further added, followed by stirring for 25 minutes. Went. The obtained solidified product was taken out, 2000 ml of water was added, and the mixture was stirred for 2 minutes, and the washing operation for removing water as much as possible was repeated 4 times. Thereafter, water was squeezed with a water squeezing roll to form a sheet, and then dried at 90 ° C. for 4 hours to obtain a composite 1. The pH of Complex 1 was 5.8.

Production Example 2: Composite 2
A composite was produced in the same manner as in Production Example 1 except that aluminum hydroxide 2 was used as aluminum hydroxide, and composite 2 was obtained. The pH of Complex 2 was 5.9.

Comparative Production Example 1: Composite 3 (without high purity)
A slurry solution was obtained by adding 1425 g of water to 75 g of aluminum hydroxide 1 and stirring vigorously for 15 minutes. After adjusting the solid content concentration (DRC) of the field latex to 30% (w / v), the aluminum hydroxide slurry solution was added to 1000 g of the latex so that the amount of aluminum hydroxide was 60 g, and vigorously at room temperature for 30 minutes. Stir. Next, 6 g of the anti-aging agent dispersion was added, and the pH was adjusted to 5.0 by adding formic acid while slowly stirring, and then the cationic polymer flocculant was added and stirred for 2 minutes to solidify. . Thereafter, water was squeezed with a water squeezing roll to form a sheet, and then dried at 90 ° C. for 4 hours to obtain a composite 3. The pH of Complex 3 was 5.3.

Comparative production example 2: UPNR1
A composite was prepared in the same manner as in Production Example 1, except that the slurry solution containing aluminum hydroxide 1 and the cationic polymer flocculant were added and stirred for 2 minutes, but no aluminum hydroxide 1 was added. , UPNR1 was obtained. The pH of UPNR1 was 4.9.

Production Example 3: Composite 4
A slurry solution was obtained by adding 1000 g of water to 175 g of silica 1 and stirring vigorously for 20 minutes. After adjusting the solid content concentration (DRC) of the field latex to 30% (w / v), the entire amount of the silica slurry solution was added to 1000 g of the latex, and vigorously stirred at room temperature for 30 minutes. Then, 25 g of 10% Emar E-27C aqueous solution and 60 g of 25% NaOH aqueous solution were added, and saponification treatment was performed at room temperature for 24 hours. Next, 6 g of the anti-aging dispersion was added and stirred for 2 hours. Next, formic acid was added with stirring to adjust the pH to 4.5, then a cationic polymer flocculant was added, stirred for 2 minutes, and 5 g of silica 1 was added, followed by stirring for 25 minutes. It was. The obtained solidified product was taken out, 2000 ml of water was added, and the mixture was stirred for 2 minutes, and the washing operation for removing water as much as possible was repeated 4 times. Thereafter, water was squeezed with a water squeezing roll to form a sheet, and then dried at 90 ° C. for 4 hours to obtain a composite 4. The pH of the complex 4 was 4.5.

Production Example 4: Composite 5
A composite was produced in the same manner as in Production Example 3 except that silica 2 was used as silica, and composite 5 was obtained. The pH of the complex 5 was 4.3.

Comparative Production Example 3: Composite 6 (without high purity)
A slurry solution was obtained by adding 1425 g of water to 75 g of silica 1 and stirring vigorously for 15 minutes. After adjusting the solid content concentration (DRC) of the field latex to 30% (w / v), the silica slurry solution was added to 1000 g of the latex so that the silica was 180 g, and the mixture was vigorously stirred at room temperature for 30 minutes. Next, 6 g of the anti-aging agent dispersion was added, and the pH was adjusted to 4.5 by adding formic acid while stirring slowly, and then the cationic polymer flocculant was added and stirred for 2 minutes to solidify. . Thereafter, water was squeezed with a water squeezing roll to form a sheet, and then dried at 90 ° C. for 4 hours to obtain a composite 6. The pH of the complex 6 was 4.4.

Comparative production example 4: UPNR2
A composite was prepared in the same manner as in Production Example 3 except that the slurry solution containing silica 1 and the cationic polymer flocculant were added and the silica 1 added after stirring for 2 minutes was not added to obtain UPNR2. It was. The pH of UPNR2 was 4.5.

Production Example 5: Composite 7
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 75 g of aluminum hydroxide 1 and stirring vigorously for 20 minutes, and after adding a cationic polymer flocculant and stirring for 2 minutes, the slurry solution was added. A composite was prepared in the same manner as in Production Example 1 except that 15 g of aluminum hydroxide 1 was used (except that 30 parts by mass of aluminum hydroxide was used relative to 100 parts by mass of the solid content of the field latex). Body 7 was obtained. The pH of the complex 7 was 5.2.

Production Example 6: Composite 8
A composite was produced in the same manner as in Production Example 6 except that aluminum hydroxide 2 was used as aluminum hydroxide, and composite 8 was obtained. The pH of the complex 8 was 5.3.

Comparative Production Example 5: Composite 9 (UPNR mixed with white filler)
A slurry solution was obtained by adding 1000 g of water to 75 g of aluminum hydroxide 1 and stirring vigorously for 20 minutes. In addition, after adjusting the solid content concentration (DRC) of the field latex to 30% (w / v), 25 g of 10% Emar E-27C aqueous solution and 60 g of 25% NaOH aqueous solution were added to 1000 g of the latex, and the mixture was stirred at room temperature for 24 hours. Saponification was performed. Next, 6 g of the anti-aging dispersion was added and stirred for 2 hours. The whole amount of the aluminum hydroxide slurry solution was added to the obtained saponified latex solution, and stirred until uniform. Next, formic acid was added with stirring to adjust the pH to 5.6, then a cationic polymer flocculant was added, stirred for 2 minutes, and further 15 g of aluminum hydroxide 1 was added, followed by stirring for 25 minutes. Went. The obtained solidified product was taken out, 2000 ml of water was added, and the mixture was stirred for 2 minutes, and the washing operation for removing water as much as possible was repeated 4 times. Thereafter, water was squeezed with a water squeezing roll to form a sheet, and then dried at 90 ° C. for 4 hours to obtain a composite 9. The pH of the complex 9 was 5.2.

Comparative Production Example 6: Composite 10 (without high purity)
A composite was produced in the same manner as in Comparative Production Example 1 except that an aluminum hydroxide slurry solution was added to 1000 g of latex so that aluminum hydroxide 1 was 90 g, and composite 10 was obtained. The pH of the composite 10 was 5.8.

Production Example 7: Composite 11
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 75 g of silica 1 and stirring vigorously for 20 minutes, and added after adding a cationic polymer flocculant and stirring for 2 minutes. The composite was prepared in the same manner as in Production Example 3 except that the amount was 15 g (except that the solid content of the field latex was 100 parts by mass and 30 parts by mass of silica). The pH of the complex 11 was 4.5.

Production Example 8: Composite 12
A composite was produced in the same manner as in Production Example 7 except that silica 2 was used as silica, and composite 12 was obtained. The pH of the composite 12 was 4.3.

Comparative Production Example 7: Composite 13 (UPNR mixed with white filler)
A composite was produced in the same manner as in Comparative Production Example 5 except that silica 1 was used in place of aluminum hydroxide 1, and composite 13 was obtained. The pH of the complex 13 was 4.4.

Comparative Production Example 8: Composite 14 (without high purity)
A composite was produced in the same manner as in Comparative Production Example 3 except that the silica slurry solution was added to 1000 g of latex so that silica 1 was 90 g, and composite 14 was obtained. The pH of the complex 14 was 4.9.

Production Example 9: Composite 15
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 120 g of aluminum hydroxide 1 and stirring vigorously for 20 minutes, and after adding a cationic polymer flocculant and stirring for 2 minutes, the slurry solution was added. A composite was produced in the same manner as in Production Example 1 except that aluminum hydroxide 1 was changed to 15 g (except that 45 mass parts of aluminum hydroxide was used relative to 100 mass parts of the solid content of the field latex). Body 15 was obtained. The pH of the complex 15 was 5.5.

Production Example 10: Composite 16
A composite was produced in the same manner as in Production Example 9 except that aluminum hydroxide 2 was used as aluminum hydroxide, and composite 16 was obtained. The pH of the composite 16 was 5.4.

Comparative production example 9: Composite 17 (UPNR mixed with white filler)
A composite was produced in the same manner as in Comparative Production Example 5 except that an aluminum hydroxide slurry solution was added to 1000 g of latex so that aluminum hydroxide 1 was 120 g, and composite 17 was obtained. The pH of the complex 17 was 5.6.

Comparative Production Example 10: Composite 18 (without high purity)
A composite was produced in the same manner as in Comparative Production Example 1 except that an aluminum hydroxide slurry solution was added to 1000 g of latex so that aluminum hydroxide 1 was 135 g, and composite 18 was obtained. The pH of the complex 18 was 5.4.

Production Example 11: Composite 19
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 135 g of silica 1 and stirring vigorously for 20 minutes, and adding the cationic polymer flocculant and stirring for 2 minutes, and then adding silica 1 The composite was prepared in the same manner as in Production Example 3 except that the amount of the silica was 15 g (except that the silica was 50 parts by mass with respect to 100 parts by mass of the solid content of the field latex). The pH of the complex 19 was 4.3.

Production Example 12: Composite 20
A composite was prepared in the same manner as in Production Example 11 except that silica 2 was used as silica, and composite 20 was obtained. The pH of the complex 20 was 4.2.

Comparative Production Example 11: Composite 21 (UPNR mixed with white filler)
A composite was prepared in the same manner as in Comparative Production Example 7 except that a silica slurry solution was added to 1000 g of latex so that silica 1 was 135 g, and composite 21 was obtained. The pH of the complex 21 was 4.3.

Comparative Production Example 12: Composite 22 (without high purity)
A composite was prepared in the same manner as in Comparative Production Example 3 except that a silica slurry solution was added to 1000 g of latex so that silica 1 was 150 g, and composite 22 was obtained. The pH of the composite 22 was 4.1.

Production Example 13: Composite 23
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 65 g of aluminum hydroxide 1 and 135 g of silica 1 and stirring vigorously for 20 minutes, and adding a cationic polymer flocculant for 2 minutes. A composite was prepared in the same manner as in Production Example 5 except that 10 g of aluminum hydroxide 1 and 15 g of silica 1 were used as the aluminum hydroxide 1 to be added after stirring, and a composite 23 was obtained. The pH of the complex 23 was 5.4.

Comparative Production Example 13: Composite 24
The slurry solution was made into a slurry solution obtained by adding 1000 g of water to 65 g of aluminum hydroxide 1 and 135 g of silica 1 and stirring vigorously for 20 minutes, and adding a cationic polymer flocculant for 2 minutes. A composite was produced in the same manner as in Comparative Production Example 5 except that 10 g of aluminum hydroxide 1 and 15 g of silica 1 were used as the aluminum hydroxide 1 added after stirring. The pH of the composite 24 was 5.0.

Production Example 14: Composite 25
A composite was produced in the same manner as in Production Example 7 except that silica 3 was used as silica, and composite 25 was obtained. The pH of the complex 25 was 4.3.

Comparative Production Example 14: Composite 26 (UPNR mixed with white filler)
A composite was produced in the same manner as in Comparative Production Example 7 except that silica 3 was used as silica, and composite 26 was obtained. The pH of the composite 26 was 4.8.

Comparative Production Example 15: Composite 27 (without high purity)
A composite was produced in the same manner as in Comparative Production Example 8 except that silica 3 was used as silica, and composite 27 was obtained. The pH of the complex 27 was 4.5.

<PH measurement method>
Each composite and UPNR 5 g were cut into a total of 5 mm or less (about 1-2 × about 1-2 × about 1-2 (mm)) and placed in a 100 ml beaker, and 50 ml of room temperature distilled water was added to add 2 The temperature was raised to 90 ° C. for 1 minute, and then irradiation with microwaves (300 W) was performed for 13 minutes (total 15 minutes) while maintaining the temperature at 90 ° C. Next, the immersion water was cooled with an ice bath to 25 ° C., and then the pH of the immersion water was measured using a pH meter.

Modified SBR production example <Preparation of terminal modifier>
In a nitrogen atmosphere, add 23.6 g of 3- (N, N-dimethylamino) propyltrimethoxysilane (manufactured by Amax Co.) to a 100 ml volumetric flask, and add anhydrous hexane (manufactured by Kanto Chemical Co., Inc.). Made to 100 ml.

<Modified S-SBR production>
In a 30 l pressure vessel sufficiently purged with nitrogen, 18 l of n-hexane, 540 g of styrene, 1460 g of butadiene and 17 mmol of tetramethylethylenediamine were added, and the temperature was raised to 40 ° C. Next, after adding 10.5 ml of butyllithium, the temperature was raised to 50 ° C. and stirred for 3 hours. Next, 30 ml of the terminal modifier was added and stirred for 30 minutes. After adding 2 ml of methanol in which 0.2 g of 2,6-tert-butyl-p-cresol (manufactured by Ouchi Shinsei Chemical Co., Ltd.) was dissolved in the reaction solution, the reaction solution was placed in a stainless steel container containing 18 l of methanol. The solidified body was recovered. The obtained solidified body was dried under reduced pressure for 24 hours to obtain modified S-SBR. As a result of the following analysis, Mw was 717,000, styrene content was 28% by mass, and vinyl bond content was 60% by mass.

Modified BR Production Example Into a 5 l autoclave, 2.4 kg of cyclohexane and 300 g of 1,3-butadiene were charged in a nitrogen atmosphere. To these, a solution of neodymium versatate (0.09 mmol) in cyclohexane, methylalumoxane (1.0 mmol) in toluene, diisobutylaluminum hydride (3.5 mmol) and diethylaluminum chloride (0.18 mmol) in toluene 1,3-butadiene (4.5 mmol) and a catalyst prepared by reaction aging at 50 ° C. for 30 minutes were charged, and a polymerization reaction was performed at 80 ° C. for 45 minutes. Next, while maintaining the reaction temperature at 60 ° C., a toluene solution of 3-glycidoxypropyltrimethoxysilane (4.5 mmol) is added, and the reaction is performed for 30 minutes, and the active terminal of the first conjugated diene polymer and The active ends of the two conjugated diene polymers were modified. Thereafter, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added. Next, the modified polymer solution was added to 20 l of an aqueous solution adjusted to pH 10 with sodium hydroxide, desolvated at 110 ° C. for 2 hours, and dried with a roll at 110 ° C. to obtain a modified BR. As a result of the following analysis, Mw was 350,000, the amount of vinyl bonds was 1.1% by mass, and the cis content was 97% by mass.

Copolymer Analysis Method <Measurement Method of Weight Average Molecular Weight Mw>
The weight average molecular weight Mw of the copolymer is a gel permeation chromatograph (GPC) (GPC-8000 series manufactured by Tosoh Corp., detector: differential refractometer, column: TSKGEL SUPERMALTPORE HZ-M manufactured by Tosoh Corp.) It calculated | required by standard polystyrene conversion based on the measured value by.

<Method for identifying structure of copolymer>
The structure of the copolymer was identified using a JNM-ECA series device manufactured by JEOL Ltd. From the measurement results, the styrene content and vinyl bond content in the copolymer were calculated.

<Method for measuring cis content>
The cis content was calculated by infrared absorption spectrum analysis (FT / IR-5300 (Fourier transform infrared spectrophotometer) manufactured by JASCO Corporation).

Examples 1 to 8 and Comparative Examples 1 to 12 (summer tires using a rubber composition containing a composite for a tread)
In accordance with the blending contents shown in Tables 1 and 2, chemicals other than sulfur and vulcanization accelerator among the blending materials are kneaded using a 1.7 l Banbury mixer for 5 minutes until the discharge temperature reaches 150 ° C. and mixed. A kneaded paste was obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded using a biaxial open roll for 5 minutes until reaching 80 ° C. to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was extruded into a tread shape, bonded together with other tire members on a tire molding machine, vulcanized at 170 ° C. for 10 minutes, and a test summer tire (tire size) 195 / 65R15, passenger car tire). The following test summer tires were subjected to the following fuel economy, wet grip, wear resistance, and odor evaluation. The results are shown in Tables 1 and 2. The reference examples of Examples 1, 2 and Comparative Examples 2 and 3 are Comparative Example 1, Examples 3, 4, and the reference examples of Comparative Examples 5 and 6 are Comparative Example 4, Examples 5, 6, Comparative Example 8 and Reference Example 9 was Comparative Example 7, Examples 7 and 8, and Comparative Examples 11 and 12 were Comparative Example 10.

<Low fuel consumption (rolling resistance characteristics)>
Using a rolling resistance tester, the rolling resistance when each test tire was run at a rim (15 × 6JJ), internal pressure (230 kPa), load (3.43 kN), speed (80 km / h) was measured, The index is displayed as an index when the reference example is 100. A larger index indicates better fuel efficiency.

<Wet grip>
Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and a braking distance from an initial speed of 100 km / h was determined on a wet asphalt road surface. The results are expressed as an index, and the larger the index, the better the wet grip property. The index was calculated by the following formula.
(Wet grip index) = (braking distance of reference example) / (braking distance of each blending example) × 100

<Abrasion resistance>
Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and the groove depth of the tire tread portion after a running distance of 8000 km was measured, and the running distance when the tire groove depth was reduced by 1 mm was obtained. The results are expressed as an index, and the larger the index, the better the wear resistance. The index was calculated by the following formula.
(Abrasion resistance index) = (travel distance when the tire groove of each blending example is reduced by 1 mm) / (travel distance when the tire groove of the reference example is reduced by 1 mm) × 100

<Odor evaluation>
Sensory evaluation based on the following criteria was evaluated with an unvulcanized rubber composition.
The odor can be felt considerably even at a distance of 5: 1 m. The odor is considerably uncomfortable when approaching 4:30 cm. The odor is felt at about 3:30 cm, the odor is felt at about 2:10 cm, and the odor is approached at about 1:10 cm. 0: Feels no odor even when the nose is moved closer

Examples 9 to 12 and Comparative Examples 13 to 18 (Winter tires using a rubber composition containing a composite as a tread)
According to the blending contents shown in Table 3, among the blended materials, chemicals other than sulfur and the vulcanization accelerator were kneaded using a 1.7 l Banbury mixer for 5 minutes until the discharge temperature reached 150 ° C. Obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded using a biaxial open roll for 5 minutes until reaching 80 ° C. to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was extruded into a tread shape, bonded together with other tire members on a tire molding machine, vulcanized at 170 ° C. for 10 minutes, and tested for winter tires (tire size) 195 / 65R15, passenger car tire). About the obtained winter tire for a test, the above-mentioned low fuel consumption property, wet grip property, abrasion resistance, odor evaluation, and the following performance evaluation on ice were performed. The results are shown in Table 3. The reference examples of Examples 9 and 10 and Comparative Examples 14 and 15 were Comparative Example 13, and the reference examples of Examples 11 and 12 and Comparative Examples 17 and 18 were Comparative Example 16.

<Performance on ice>
Each test winter tire was mounted on all wheels of a vehicle (domestic FF2000cc), and the stopping distance on ice required to step on and stop the lock brake at 30 km / h was measured. The performance index on ice was calculated from the following formula. The larger the index, the better the performance on ice. The test was conducted at the Hokkaido Nayoro Test Course of Sumitomo Rubber Industries, Ltd., and the temperature on ice was −2 to −6 ° C.
(Performance index on ice) = (braking stop distance of reference example) / (stop distance of each blending example) × 100

Example 13 and Comparative Example 19 (summer tires using a rubber composition containing a composite for a tread) and Example 14 and Comparative Example 20 (winter use using a rubber composition containing a composite for a tread) tire)
According to the blending contents shown in Table 4, chemicals other than sulfur and vulcanization accelerator are kneaded for 5 minutes until the discharge temperature reaches 150 ° C. using a 1.7 l Banbury mixer. Obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded using a biaxial open roll for 5 minutes until reaching 80 ° C. to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition is extruded into a tread shape, bonded together with other tire members on a tire molding machine, vulcanized at 170 ° C. for 10 minutes, and used for a test summer tire or test A winter tire (tire size: 195 / 65R15, passenger car tire) was produced. The test tire thus obtained was evaluated for fuel efficiency, wet grip, wear resistance, and odor as described above, and the performance on ice was further evaluated for the winter tire. The results are shown in Table 4. The reference example of Example 13 was Comparative Example 19, and the reference example of Example 14 was Comparative Example 20.

  From the results of Tables 1, 2 and 4, the summer tire using the rubber composition containing the composite obtained by the production method of the present invention in the tread has less odor peculiar to natural rubber, low fuel consumption, wet It can be seen that the grip and wear resistance are excellent. Further, from the results of Tables 3 and 4, the winter tire using the rubber composition containing the composite obtained by the production method of the present invention for the tread has less odor peculiar to natural rubber, low fuel consumption, on ice It can be seen that it has excellent performance, wet grip and wear resistance.

Example 15 and Comparative Examples 21 to 23 (tires using a rubber composition containing a composite as a sidewall)
According to the blending contents shown in Table 5, among the blended materials, chemicals other than sulfur and the vulcanization accelerator were kneaded using a 1.7 l Banbury mixer for 5 minutes until the discharge temperature reached 150 ° C. Obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded using a biaxial open roll for 5 minutes until reaching 80 ° C. to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was extruded into a sidewall shape, bonded together with other tire members on a tire molding machine, vulcanized at 170 ° C. for 10 minutes, and a test tire (tire size: 195 / 65R15, passenger car tire). The test tire thus obtained was evaluated for fuel economy, odor, and resistance to flex crack growth and steering stability described below. The results are shown in Table 5. The reference example was Comparative Example 21.

<Flexible crack growth resistance>
A test piece was cut out from the side wall of the test tire, a sample of the vulcanized rubber composition was prepared based on JIS K6260 “Vulcanized Rubber and Thermoplastic Rubber—Dematcher Flexural Crack Test Method”, and a flexural crack growth test was performed. After the sample was bent by repeating 70% stretching 1 million times, the length of the cracks generated was measured. The result is shown as an index with the reciprocal of the measured value (length) of Comparative Example 19 as 100. The results are expressed as an index. The larger the index, the more the crack growth is suppressed and the better the resistance to flex crack growth. The index was calculated by the following formula.
(Bending crack growth resistance index) = (Crack length of reference example) / (Crack length of each formulation) × 100

<Steering stability>
Test tires are mounted on all wheels of a test vehicle (domestic FF vehicle, displacement: 2000cc) and run on the test track. The test driver performs sensory evaluation on the stability of control during steering. Is shown by a 10-point method with 6 points The larger the score, the better the steering stability.

  From the results of Table 5, the tire using the rubber composition containing the composite obtained by the production method of the present invention for the side wall has less odor peculiar to natural rubber, low fuel consumption, resistance to flex crack growth, It can also be seen that the steering stability is excellent.

  Further, from the results of Tables 1 to 5, a tire using a rubber composition containing a composite obtained by the production method of the present invention as a tire member has less odor peculiar to natural rubber, and has low fuel consumption. It turns out that it is excellent in physical properties.

Claims (22)

Mixing step of mixing natural rubber latex and white filler A,
A purification step for purifying the mixture obtained in the mixing step,
A method for producing a natural rubber-white filler composite comprising a coagulation drying step in which a highly purified product obtained in the high purification step is coagulated and dried. The production method according to claim 1, wherein the white filler A is aluminum hydroxide having an average particle diameter of less than 1.5 μm. The production method according to claim 2, wherein an average particle diameter of the aluminum hydroxide is 0.7 μm or less. The production method according to claim 1, wherein the white filler A is silica. The manufacturing method according to claim 4, wherein the silica has a BET specific surface area of 50 m ² / g or more. The production method according to any one of claims 1 to 5, wherein the content of the white filler A with respect to 100 parts by mass of the rubber component in the composite is 5 to 80 parts by mass. The production method according to any one of claims 1 to 6, wherein the purification treatment in the purification step is a saponification treatment. A tire provided with the tire member comprised with the rubber composition containing the natural rubber-white filler composite body manufactured with the manufacturing method of Claims 1-7. Mixing step of mixing natural rubber latex and aluminum hydroxide having an average particle size of less than 1.5 μm;
A purification step for purifying the mixture obtained in the mixing step,
A natural rubber-aluminum hydroxide composite obtained by a method for producing a natural rubber-white filler composite, comprising a coagulation drying step for coagulating and drying the highly purified product obtained in the purification step,
And a tire comprising a tread composed of a rubber composition containing butadiene rubber. Mixing step of mixing natural rubber latex and aluminum hydroxide having an average particle size of less than 1.5 μm;
A purification step for purifying the mixture obtained in the mixing step,
A natural rubber-aluminum hydroxide composite obtained by a method for producing a natural rubber-white filler composite, comprising a coagulation drying step for coagulating and drying the highly purified product obtained in the purification step,
And a tire provided with a tread composed of a rubber composition containing styrene-butadiene rubber. Mixing step of mixing natural rubber latex and silica,
A purification step for purifying the mixture obtained in the mixing step,
A natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite, comprising a coagulation drying step for coagulating and drying the highly purified product obtained in the high purification step,
And a tire comprising a tread composed of a rubber composition containing butadiene rubber. Mixing step of mixing natural rubber latex and silica,
A purification step for purifying the mixture obtained in the mixing step,
A natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite, comprising a coagulation drying step for coagulating and drying the highly purified product obtained in the high purification step,
And a tire provided with a tread composed of a rubber composition containing styrene-butadiene rubber. Mixing step of mixing natural rubber latex and silica,
A purification step for purifying the mixture obtained in the mixing step,
A natural rubber-silica composite obtained by a method for producing a natural rubber-white filler composite, comprising a coagulation drying step for coagulating and drying the highly purified product obtained in the high purification step,
And a tire comprising a sidewall composed of a rubber composition containing butadiene rubber. The tire according to claim 9 or 10, wherein an average particle diameter of the aluminum hydroxide is 0.7 µm or less. The tire according to claim 11, wherein the silica has a BET specific surface area of 50 m ² / g or more. The tire according to any one of claims 9 to 15, wherein the content of aluminum hydroxide or silica in the composite with respect to 100 parts by mass of the rubber component in the composite is 5 to 80 parts by mass. The tire according to any one of claims 9 to 16, wherein the purification process in the purification process is a saponification process. The tire according to any one of claims 8 to 17, wherein the complex has a pH of 2 to 7. The tire according to any one of claims 8 to 18, wherein the rubber composition is a rubber composition further containing silica and / or carbon black. The tire according to any one of claims 9, 11, and 13, wherein the butadiene rubber is a butadiene rubber having a functional group that interacts with silica. The tire according to any one of claims 9, 11, and 13, wherein the butadiene rubber is a butadiene rubber having a cis content of 90% by mass or more. The tire according to claim 10 or 12, wherein the styrene-butadiene rubber is a styrene-butadiene rubber having a functional group that interacts with silica.