JP5299733B2 - Rubber composition and method for producing pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition reducing the using amount of raw materials originated from petroleum resources, and also imparted with a good weather resistance, a pneumatic tire having a tread rubber consisting of the rubber composition, and a pneumatic tire having a side wall rubber consisting of the rubber composition. <P>SOLUTION: This rubber composition contains 100 pts.mass rubber component and &ge;1 pt.mass carbon black made by purifying wood tar, and the rubber component consists of at least any one of natural rubber and a modified natural rubber. The pneumatic tire having the tread rubber consisting of the above rubber composition and the pneumatic tire equipped with the side wall rubber consisting of the above rubber composition are also provided. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a rubber composition, a pneumatic tire including a tread rubber made of the rubber composition, and a pneumatic tire including a sidewall rubber made of the rubber composition.

  Conventionally, as a rubber composition for tires, carbon black has been widely used as a reinforcing filler for imparting desired mechanical strength and rubber hardness. However, in recent years, methods for reducing the amount of raw materials derived from petroleum resources have been studied in various technical fields due to increasing interest in environmental problems. Currently, commercially available tires are composed of raw materials in which more than half of the total weight is petroleum resources. For example, a general tire for a passenger car contains about 20% by mass of synthetic rubber, about 20% by mass of carbon black, a softener, a synthetic fiber, and the like, so that about 50% by mass or more of the entire tire is derived from raw materials of petroleum resources. It is configured. Accordingly, it is desired to develop a rubber for tires using a raw material derived from a natural resource that satisfies the same or more required characteristics as when using a raw material derived from a petroleum resource.

Patent Document 1 proposes a tire in which 75% by weight or more of the total weight is made of raw materials made of resources other than petroleum for the purpose of providing a tire that is friendly to the earth. However, for example, in tire applications, particularly for tread rubber and sidewall rubber, the rubber is required to have practically sufficient weather resistance, and the conventional technology reduces the amount of raw materials derived from petroleum resources. However, no rubber composition capable of imparting good weather resistance has been proposed.
JP 2003-063206 A

  The present invention solves the above-mentioned problems, reduces the amount of raw materials derived from petroleum resources, and imparts good weather resistance, a pneumatic tire comprising a tread rubber comprising the rubber composition, and An object of the present invention is to provide a pneumatic tire including a sidewall rubber made of the rubber composition.

  The present invention provides a rubber composition comprising 100 parts by mass of a rubber component and 1 part by mass or more of carbon black purified from wood tar, wherein the rubber component is at least one of natural rubber and modified natural rubber. .

  In the rubber composition of the present invention, the modified natural rubber is preferably an epoxidized natural rubber.

  The present invention also provides a pneumatic tire provided with a tread rubber made of any of the above rubber compositions.

  The present invention also provides a pneumatic tire including a sidewall rubber made of any of the rubber compositions described above.

  According to the present invention, a rubber composition having reduced use amount of raw materials derived from petroleum resources and imparted with good weather resistance, a pneumatic tire provided with a tread rubber comprising the rubber composition, and the rubber composition It is possible to provide a pneumatic tire provided with a side wall rubber.

  The present invention provides a rubber composition comprising 100 parts by mass of a rubber component and 1 part by mass or more of carbon black purified from wood tar, wherein the rubber component is at least one of natural rubber and modified natural rubber. .

<Rubber component>
In the rubber composition of the present invention, the rubber component comprises at least one of natural rubber and modified natural rubber. By using the rubber component, the amount of raw material derived from petroleum resources can be reduced.

  Any natural rubber may be used as long as it is known as natural rubber, and the place of origin is not limited. Such natural rubber mainly contains cis 1,4 polyisoprene, but can also contain trans 1,4 polyisoprene according to required characteristics. Therefore, the natural rubber includes natural rubber mainly containing trans 1,4 isoprene, such as balata, which is a kind of rubber from the South American Acatecaceae family, in addition to natural rubber mainly containing cis 1,4 polyisoprene. It is. The natural rubber component in the present invention may contain one or more of such natural rubbers (that is, one component or two or more components). As such natural rubber, for example, natural rubber of grades such as RSS # 3 and TSR can be suitably used.

  As the modified natural rubber, for example, epoxidized natural rubber, hydrogenated natural rubber and the like can be suitably used. It is preferable that the modified natural rubber is an epoxidized natural rubber because it is easy to achieve both reduction of the amount of the raw material derived from petroleum resources and ensuring good rubber properties.

  Epoxidized natural rubber is a kind of modified natural rubber in which unsaturated double bonds of natural rubber are epoxidized, and molecular cohesion is increased by epoxy groups that are polar groups. Therefore, the glass transition temperature (Tg) is higher than that of natural rubber, and the mechanical strength, wear resistance, and air permeation resistance are excellent. Examples of such epoxidized natural rubber include commercially available products such as ENR25 (manufactured by Clamp-Lance Gully) (epoxidation rate: 25%), ENR 50 (made by Clamp-Lance Gully) (epoxidation rate: 50%), and the like. You may use what was used and what epoxidized natural rubber may be used. The method for epoxidizing natural rubber is not particularly limited, and examples thereof include a chlorohydrin method, a direct oxidation method, a hydrogen peroxide method, an alkyl hydroperoxide method, and a peracid method. Examples of the peracid method include a method of reacting an organic peracid such as peracetic acid or performic acid as an epoxidizing agent with an emulsion of natural rubber.

  The epoxidation rate of the epoxidized natural rubber (ENR) is preferably 5 mol% or more, and more preferably 10 mol% or more. Here, the epoxidation rate is the ratio of the number of epoxidized to the total number of double bonds in natural rubber before epoxidation ((number of epoxidized double bonds) / (two before epoxidation). The number of double bonds)), and is determined by titration analysis, nuclear magnetic resonance (NMR) analysis, or the like. When the epoxidation rate of the epoxidized natural rubber (ENR) is less than 5 mol%, the glass transition temperature of the epoxidized natural rubber (ENR) is low, so that the mechanical strength provided by the rubber composition is reduced and the wear resistance is reduced. The improvement effect tends to be low. The epoxidation rate of the epoxidized natural rubber (ENR) is preferably 65 mol% or less, and more preferably 60 mol% or less. When the epoxidation rate of epoxidized natural rubber (ENR) exceeds 65 mol%, the rubber hardness tends to be too high and the mechanical strength imparted by the rubber composition tends to be low.

  The rubber component is particularly preferably made of natural rubber (NR) in that the rubber composition gives particularly excellent mechanical strength.

  Note that part or all of the natural rubber (NR) may be deproteinized natural rubber (DPNR), or part or all of the modified natural rubber may be modified rubber of the deproteinized natural rubber (DPNR). good.

<Carbon black>
The rubber composition of the present invention contains carbon black obtained by refining wood tar in addition to the rubber component described above. Carbon black obtained by refining wood tar typically means carbon black produced by an oil furnace method using wood tar generated as a by-product when producing charcoal, and in the present invention. For example, carbon black obtained as described above is used.

  Since wood tar is derived from non-petroleum resources, by using carbon black obtained by refining wood tar, it is possible to sufficiently improve the weather resistance while reducing the amount of raw materials derived from petroleum resources. it can.

  The amount of carbon black obtained by refining wood tar is 1 part by mass or more with respect to 100 parts by mass of the rubber component. When the blending amount of the carbon black is less than 1 part by mass, it is impossible to achieve both a reduction in the amount of use of raw materials derived from petroleum resources and a sufficient effect of improving weather resistance to the rubber composition. The blending amount of the carbon black is more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more. On the other hand, the amount of carbon black obtained by refining wood tar is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less with respect to 100 parts by mass of the rubber component. . When the blending amount of the carbon black exceeds 100 parts by mass, the rubber becomes hard and the mechanical strength tends to be lowered.

  The rubber composition of the present invention may contain petroleum resource-derived carbon black as long as the effects of the present invention are not impaired, but the content of the petroleum resource-derived carbon black is 100 masses per 100 parts by mass of the rubber component. Part or less, preferably 50 parts by weight or less, and most preferably the rubber composition of the present invention does not contain carbon black derived from petroleum resources.

  Examples of carbon black derived from petroleum resources include Show Black N220 (manufactured by Cabot Japan Co., Ltd.).

<Silica>
The rubber composition of the present invention may contain silica. Silica functions as a reinforcing filler, and the mechanical strength imparted by the rubber composition can be improved by blending silica. Further, since silica is derived from resources other than petroleum, for example, the amount of raw material derived from petroleum resources in the rubber composition can be reduced as compared with the case where petroleum-derived carbon black or the like is blended as a main reinforcing agent.

The nitrogen adsorption specific surface area of silica is preferably in the range of 100 to 200 m ² / g. When the nitrogen adsorption specific surface area of silica is less than 100 m ² / g, the reinforcing effect tends to be small, and when it exceeds 200 m ² / g, the workability during preparation of the rubber composition tends to be low. The nitrogen adsorption specific surface area of silica is more preferably 120 m ² / g or more, and more preferably 180 m ² / g or less.

  In addition, the nitrogen adsorption specific surface area of the silica mentioned above can be measured by a method based on, for example, ASTM-D-4820-93.

Silica may be prepared by a wet method or may be prepared by a dry method. Examples of preferable commercial products include Ultrazil VN2 (manufactured by Degussa) (nitrogen adsorption specific surface area: 125 m ² / g), Ultrasil VN3 (manufactured by Degussa) (nitrogen adsorption specific surface area: 175 m ² / g), and the like. it can.

<Silane coupling agent>
When the rubber composition of this invention contains a silica, it is preferable to mix | blend a silane coupling agent with this silica. As the silane coupling agent, a conventionally known silane coupling agent can be used. For example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4- Triethoxysilylbutyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxy Silylpropyl) trisulfide, bis (2-triethoxysilylethyl) trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) ) Resulfide, bis (4-trimethoxysilylbutyl) trisulfide, 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-trimethoxy Ethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthio Rubamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, etc. Sulfide type; mercapto type such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane; vinyltriethoxysilane, vinyltrimethoxysilane, etc. Vinyl-based; 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxy Amino series 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 , Chloro-based compounds such as 2-chloroethyltrimethoxysilane and 2-chloroethyltriethoxysilane; These silane coupling agents may be used alone or in combination of two or more.

  Among the above, Si69 (made by Degussa) (bis (3-triethoxysilylpropyl) tetrasulfide), Si266 (made by Degussa) (bis (3-triethoxysilylpropyl) disulfide because of good processability Etc.) are preferably used.

  When the silane coupling agent is further contained, the content thereof is not particularly limited, but is 4% by mass or more, and more preferably 6% by mass or more when the blending amount of silica is 100% by mass. preferable. When the content of the silane coupling agent is less than 4% by mass, the workability at the time of kneading and extruding the rubber tends to decrease, and the reinforcing effect on the rubber composition tends to be small. . Further, the content of the silane coupling agent is preferably 15% by mass or less, more preferably 12% by mass or less, and further preferably 10% by mass or less, based on the amount of silica as 100% by mass. When the content of the silane coupling agent exceeds 15% by mass, even if the amount of the silane coupling agent is increased, the workability at the time of kneading and extruding the rubber and the effect of improving the reinforcing effect on the rubber composition Although it is small, the cost tends to increase and it is not economical.

<Other ingredients>
In addition to the components described above, the rubber composition of the present invention includes other compounding agents conventionally used in the rubber industry, such as vulcanizing agents, stearic acid, vulcanization accelerators, vulcanization accelerators, oils, and curing agents. Resins, waxes, anti-aging agents and the like may be blended.

  As the vulcanizing agent, an organic peroxide or a sulfur-based vulcanizing agent can be used. Examples of the organic peroxide include benzoyl peroxide, dicumyl peroxide, and di-t-butyl peroxide. , T-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoyl) Peroxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 or 1,3-bis (t-butylperoxypropyl) benzene, di-t-butylperoxy- Diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoyl peroxide, 1,1-di t- butyl peroxy-3,3,5-trimethyl siloxane, and the like can be used n- butyl-4,4-di -t- butyl peroxy valerate. Of these, dicumyl peroxide, t-butylperoxybenzene and di-t-butylperoxy-diisopropylbenzene are preferred. Moreover, as a sulfur type vulcanizing agent, sulfur, morpholine disulfide, etc. can be used, for example. Of these, sulfur is preferred. These vulcanizing agents may be used alone or in combination of two or more.

  Vulcanization accelerators include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine or aldehyde-ammonia, imidazoline, or xanthate vulcanization accelerators. Those containing at least one of them can be used. Examples of the sulfenamide system include CBS (N-cyclohexyl-2-benzothiazylsulfenamide), TBBS (N-tert-butyl-2-benzothiazylsulfenamide), N, N-dicyclohexyl-2- Sulfenamide compounds such as benzothiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide, and N, N-diisopropyl-2-benzothiazolesulfenamide can be used. Examples of the thiazole type include MBT (2-mercaptobenzothiazole), MBTS (dibenzothiazyl disulfide), sodium salt of 2-mercaptobenzothiazole, zinc salt, copper salt, cyclohexylamine salt, 2- (2,4-dinitro). Thiazole compounds such as phenyl) mercaptobenzothiazole and 2- (2,6-diethyl-4-morpholinothio) benzothiazole can be used. Examples of thiurams include TMTD (tetramethyl thiuram disulfide), tetraethyl thiuram disulfide, tetramethyl thiuram monosulfide, dipentamethylene thiuram disulfide, dipentamethylene thiuram monosulfide, dipentamethylene thiuram tetrasulfide, dipentamethylene thiuram hexasulfide. Further, thiuram compounds such as tetrabutylthiuram disulfide and pentamethylenethiuram tetrasulfide can be used. As the thiourea series, for example, thiourea compounds such as thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diortolylthiourea and the like can be used. Examples of guanidine-based compounds include guanidine-based compounds such as diphenylguanidine, diortolylguanidine, triphenylguanidine, orthotolylbiguanide, and diphenylguanidine phthalate. Examples of dithiocarbamate include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate , Complex salt of zinc pentamethylenedithiocarbamate and piperidine, zinc hexadecyl (or octadecyl) isopropyldithiocarbamate, zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate, diamyl Such as cadmium dithiocarbamate And the like can be used thiocarbamate compound. As the aldehyde-amine system or aldehyde-ammonia system, for example, an aldehyde-amine system such as an acetaldehyde-aniline reaction product, butyraldehyde-aniline condensate, hexamethylenetetramine, an acetaldehyde-ammonia reaction product, or an aldehyde-ammonia system compound is used. can do. As the imidazoline-based compound, for example, an imidazoline-based compound such as 2-mercaptoimidazoline can be used. As the xanthate type, for example, a xanthate type compound such as zinc dibutylxanthate can be used. These vulcanization accelerators may be used alone or in combination of two or more.

As the vulcanization acceleration aid, for example, zinc oxide, stearic acid and the like can be used.
As the anti-aging agent, an amine-based, phenol-based or imidazole-based anti-aging agent, a carbamic acid metal salt, or the like can be appropriately selected and used.

  Examples of the oil include process oil, vegetable oil and fat, or a mixture thereof. Examples of the process oil include paraffinic process oil, naphthenic process oil, and aromatic process oil. Vegetable oils include castor oil, cottonseed oil, sesame oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pineapple, tall oil, corn oil, rice bran oil, bean flower oil, sesame oil, olive oil, Examples include sunflower oil, palm kernel oil, cocoon oil, jojoba oil, macadamia nut oil, safflower oil, tung oil, and the like.

<Pneumatic tire>
The present invention also provides a pneumatic tire having at least a tread rubber made of the rubber composition of the present invention as described above, and a pneumatic tire having at least a sidewall rubber made of the rubber composition. FIG. 1 is a schematic cross-sectional view showing an example of the pneumatic tire of the present invention. The pneumatic tire 1 includes a tread portion 2, a pair of sidewall portions 3 extending inward in the tire radial direction from both ends of the tread portion 2, and a bead portion 4 positioned at an inner end of each sidewall portion 3. Prepare. A carcass 6 is bridged between the bead portions 4 and 4, and a belt layer 7 is provided outside the carcass 6 and inside the tread portion 2 to reinforce the tread portion 2 with a tagging effect.

  The carcass 6 is formed of one or more carcass plies in which the carcass cord is arranged at an angle of, for example, 70 to 90 ° with respect to the tire equator CO. The carcass ply extends from the tread portion 2 to the sidewall portion 3. After that, the periphery of the bead core 5 of the bead portion 4 is folded back from the inner side in the tire axial direction to be locked.

  The belt layer 7 is composed of two or more belt plies in which the belt cords are arranged at an angle of, for example, 40 ° or less with respect to the tire equator CO. The belt layers 7 are stacked in different directions so that the belt cords cross each other. doing. If necessary, a band layer (not shown) for preventing lifting at both ends of the belt layer 7 may be provided at least outside the belt layer 7. At this time, the band layer is formed of a low modulus organic fiber. The cord is formed of a continuous ply spirally wound substantially parallel to the tire equator CO.

  Further, a bead apex rubber 8 extending radially outward from the bead core 5 is disposed in the bead portion 4, and an inner liner rubber 9 forming a tire lumen surface is adjacent to the inside of the carcass 6. The outside of the carcass 6 is protected by clinch rubber 4G and sidewall rubber 3G. The rubber composition of the present invention can be preferably applied to, for example, the sidewall rubber 3G and the tread rubber 4G.

  FIG. 1 illustrates a pneumatic tire for a passenger car, but the present invention is not limited to this, and is used for various vehicles such as a passenger car, a truck, a bus, and a heavy vehicle. Provided pneumatic tires.

  The pneumatic tire of the present invention is produced by a conventionally known method using the rubber composition of the present invention. That is, a rubber composition containing the above-described essential components and other compounding agents blended as necessary is kneaded, and at an unvulcanized stage, for example, at least one of tread rubber and sidewall rubber of the tire The unvulcanized tire is formed by extruding in accordance with the shape of the tire and molding it together with other members of the tire by a usual method on a tire molding machine. The tire of the present invention can be obtained by heating and pressurizing the unvulcanized tire in a vulcanizer.

  Such a pneumatic tire of the present invention has a reduced content ratio of components derived from petroleum resources in at least a member to which the rubber composition of the present invention is applied, such as tread rubber and sidewall rubber, for resource saving and environmental protection. Since the rubber composition giving sufficient weather resistance is used, it is an “eco-tyre” that is friendly to the global environment and has good weather resistance.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Examples 1 and 2 and Comparative Examples 1 to 4>
In accordance with the formulation shown in Table 1, using a 1.7L Banbury mixer manufactured by Kobe Steel, the components other than sulfur and vulcanization accelerator were filled so that the filling rate would be 58%, and the rotational speed was 80 rpm. And kneading for 3 minutes until reaching 140 ° C. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded material in the amounts shown in Table 1, and then kneaded for 5 minutes at 80 ° C. using an open roll. Examples 1, 2 and Comparative Example 1 The unvulcanized rubber sheet blended according to -4 was extruded. This was formed on the tire tread portion for Example 1 and Comparative Examples 1 and 2, and on the sidewall portion for Examples 2 and 3 and 4, and together with other members of the tire, on the tire molding machine. An unvulcanized tire was formed by molding in a conventional manner. This unvulcanized tire was heated and pressurized at 150 ° C. for 30 minutes in a vulcanizer to produce a size 195 / 65R15 pneumatic tire having the structure shown in FIG. 1 as a test tire.

(Weatherability)
The weather resistance of the obtained test tire was evaluated. The test tires according to each of the examples and the comparative examples were each mounted on a passenger car and allowed to travel 30000 km. The surface condition of the side portion of the tire after running was evaluated in three stages according to the following criteria.
A: No crack was generated.
B: Wrinkles occurred.
C: A crack occurred.

(Non-oil ratio)
From the blending amounts of the blending components in each Example and each Comparative Example, the following formula,
Non-petroleum ratio = (blending amount of blending components derived from non-petroleum resources (parts by mass)) ÷ (sum of blending amounts of all blending components (parts by weight)) × 100
From the above, the non-oil ratio (mass%) was calculated and evaluated in two stages according to the following criteria.
A: The ratio outside of petroleum is 96% by mass or more.
B: The ratio outside of petroleum is less than 96% by mass.

  Among the ingredients shown in Table 1, the ingredients derived from non-petroleum resources are natural rubber, wood tar carbon, silica, vegetable oil, silane coupling agent, stearic acid, zinc oxide, and sulfur. The blending components are ISAF, FEF, wax, anti-aging agent, and vulcanization accelerator.

The detail of the various compounding component used by each Example and each comparative example is as follows.
(1) Natural rubber (NR): “TSR20” grade (2) ISAF: “Diamond Black I” manufactured by Mitsubishi Chemical Corporation
(3) FEF: “Diamond Black E” manufactured by Mitsubishi Chemical Corporation
(4) Wood tar carbon: Carbon black produced by the oil furnace method using wood tar generated as a by-product when producing charcoal (nitrogen adsorption specific surface area: 125 m ² / g, DBP oil absorption: 105 cm ³ / 100g)
(5) Silica: “Ultra Gil VN3” manufactured by Degussa Huls Co., Ltd. (nitrogen adsorption specific surface area: 175 m ² / g)
(6) Silane coupling agent: “Si-69” manufactured by Degussa Huls Co., Ltd.
(7) Vegetable oil: “refined palm oil J (S)” manufactured by Nissin Oil Co., Ltd.
(8) Wax: “Ozoace 0355” manufactured by Nippon Seiki Co., Ltd.
(9) Anti-aging agent: “Antigen 6C” manufactured by Sumitomo Chemical Co., Ltd.
(10) Stearic acid: “Stearic acid cake” manufactured by Nippon Oil & Fats Co., Ltd.
(11) Zinc oxide: "Zinc oxide type 2" manufactured by Mitsui Mining & Smelting Co., Ltd.
(12) Sulfur: “Powder sulfur” manufactured by Tsurumi Chemical Co., Ltd.
(13) Vulcanization accelerator: “Noxeller NS” manufactured by Ouchi Shinsei Chemical Co., Ltd.
From the results shown in Table 1, in Example 1 and Comparative Examples 1 and 2 in which the tread rubber compounding was studied, the ratio outside the petroleum was low in Comparative Example 1 using ISAF for the tread rubber compounding, and no carbon was used. In Comparative Example 2, the weather resistance was low, whereas in Example 1 using wood tar carbon, the weather resistance was good and the ratio outside of petroleum could be increased.

  Further, in Example 2 and Comparative Examples 3 and 4 in which the blending of the sidewall rubber was examined, Comparative Example 4 in which FEF was used for the blending of the sidewall rubber had a low ratio outside of petroleum and no carbon was used. In Example 2, which used wood tar carbon, the weather resistance was good and the ratio outside of petroleum could be increased.

  From the above results, it can be seen that by using the rubber composition of the present invention, it is possible to give good weather resistance while reducing the amount of the raw material derived from petroleum resources.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic sectional drawing which shows an example of the pneumatic tire of this invention.

Explanation of symbols

  1 tire, 2 tread part, 3 side wall part, 3G side wall rubber, 4 bead part, 4G clinch rubber, 5 bead core, 6 carcass, 7 belt layer, 8 bead apex rubber, 9 inner liner rubber.

Claims (4)

A method for producing a rubber composition, comprising:
Preparing carbon black by refining wood tar;
A step of mixing 100 parts by mass of a rubber component and 1 part by mass or more of the carbon black to obtain a rubber composition,
The method for producing a rubber composition, wherein the rubber component comprises at least one of natural rubber and modified natural rubber. The method for producing a rubber composition according to claim 1, wherein the modified natural rubber is an epoxidized natural rubber. A pneumatic tire manufacturing method comprising:
Preparing carbon black by refining wood tar;
Mixing 100 parts by mass of a rubber component and 1 part by mass or more of the carbon black to obtain a rubber composition;
Applying the rubber composition to the tread portion to mold a pneumatic tire,
The method for producing a pneumatic tire, wherein the rubber component is made of at least one of natural rubber and modified natural rubber. A pneumatic tire manufacturing method comprising:
Preparing carbon black by refining wood tar;
Mixing 100 parts by mass of a rubber component and 1 part by mass or more of the carbon black to obtain a rubber composition;
Applying the rubber composition to the sidewall portion and forming a pneumatic tire,
The method for producing a pneumatic tire, wherein the rubber component is made of at least one of natural rubber and modified natural rubber.

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