JP2023017696A - Rubber composition and tire - Google Patents

Abstract

To provide a rubber composition having excellent overall performance of low fuel consumption and bleed resistance and good LCA performance (such as CO2 emissions reduction) and to provide a tire using the rubber composition.SOLUTION: There is provided a rubber composition comprising a vegetable oil which satisfies the following conditions (1) to (4). (1) The rubber composition is a liquid state at a temperature of 23°C. (2) The rubber composition has a weight average molecular weight determined by a GPC method of more than 800. (3) The absorbance at wavelengths of 450 nm and 600 nm measured by a spectrophotometer of a vegetable oil after diluted 3 times with THF satisfies the following expression: (the absorbance at a wavelength of 450 nm)-(the absorbance at a wavelength of 600 nm)≥0.05. (4) The weights before and after passing 100 g of a vegetable oil at a temperature of 23 to 30°C through a plain weave wire net having 20 mesh satisfies the following expression: (the weight after passing through the plain weave wire net)/(the weight before passing through the plain weave wire net)×100≥99.0.SELECTED DRAWING: None

Description

The present invention relates to rubber compositions and tires.

Mineral oil and the like are widely used as plasticizers or softeners for rubber. However, from the viewpoint of future depletion of fossil resources, environmental load, etc., the use of vegetable oil as a substitute is being studied (see Patent Document 1). Improvements in bleed resistance, LCA performance (reduction of _CO2 emissions, etc.), etc. are desired.

JP-A-2003-63206

The present invention solves the above problems, and provides a rubber composition that is excellent in overall performance of fuel efficiency and bleed resistance, and also has good LCA performance (reduction of _CO2 emissions, etc.), and a tire using the same. With the goal.

The present invention relates to a rubber composition containing vegetable oil that satisfies the following conditions (1) to (4).
(1) It is in a liquid state at a temperature of 23°C.
(2) Weight average molecular weight exceeding 800 by GPC method.
(3) The diluted vegetable oil diluted 3-fold with THF has absorbance at wavelengths of 450 nm and 600 nm measured with a spectrophotometer that satisfies the following formula.
Absorbance at wavelength 450 nm - Absorbance at wavelength 600 nm ≥ 0.05
(4) The weight before and after passing 100 g of vegetable oil at a temperature of 23 to 30° C. through a 20-mesh plain-woven wire mesh satisfies the following formula.
(Weight after passing through plain weave wire mesh / Weight before passing through plain weave wire mesh) × 100 ≥ 99.0

The present invention is a rubber composition containing vegetable oil that satisfies the above conditions (1) to (4). The rubber composition is excellent in overall performance of fuel efficiency and bleed resistance, and also has good LCA performance (reduction of _CO2 emissions, etc.).

Although the mechanism by which such action and effect are obtained is not necessarily clear, it is presumed that the following actions and functions are exhibited.
Vegetable oils that satisfy the above conditions (1) to (4) interact with fillers such as carbon black by conjugating carbonyls to double bonds, and the double bonds are reduced in this way. As a result, the vegetable oil tends to have a low Tg and a low tan δ, which is thought to improve fuel efficiency. Compared to mineral oils with an Mw of 200 to 700 g/mol, a vegetable oil with an Mw of more than 800 g/mol is considered to have a higher molecular weight, resulting in lower fluidity in rubber and improved bleed resistance. Furthermore, by adopting biomass material vegetable oil, it is possible to reduce _CO2 emissions at the time of disposal compared to mineral oil from the viewpoint of carbon neutrality. By adopting vegetable oil for recycling, it is possible to reduce _CO2 emissions from the production and transportation of raw materials, so it has excellent LCA performance. From the above, it is presumed that the rubber composition is excellent in overall performance of fuel efficiency and bleed resistance, and is also good in LCA performance (reduction of _CO2 emissions, etc.).

In this way, the present invention is configured with a vegetable oil that satisfies the above conditions (1) to (4), so that overall performance of fuel efficiency and bleed resistance, LCA performance (reduction of CO ₂ emissions, etc.) This is to solve the problem (objective) of improving the That is, the above conditions (1) to (4) do not define the subject (purpose), but the subject of the present application is the overall performance of fuel efficiency and bleed resistance, LCA performance (reduction of _CO2 emissions, etc.). It is an improvement, and as a solution for that purpose, the vegetable oil of the above conditions (1) to (4) is essential.

(Vegetable oil)
From the viewpoint of LCA (Life Cycle Assessment), it is desirable to use vegetable oil (plant-derived glycerol fatty acid triester) in the rubber composition. Here, glycerol fatty acid triester is an ester of fatty acid and glycerin, and is also called triglyceride or tri-O-acylglycerin.

The vegetable oil used in the rubber composition is in a liquid state at a temperature of 23°C (condition (1)).
Since it is a material in a liquid state at 23°C, it functions as a plasticizer for the rubber composition. As used herein, a plasticizer is a material that imparts plasticity to a rubber component.

The vegetable oil has a weight average molecular weight (Mw) of more than 800 by GPC method (condition (2)). In other words, the vegetable oil has an Mw value of more than 800, which is calculated by standard polystyrene conversion based on the measurement value by gel permeation chromatography (GPC).

The vegetable oil has a weight average molecular weight (Mw) of more than 800, preferably 850 or more, more preferably 900 or more, even more preferably 950 or more, and particularly preferably 1000 or more, as measured by gel permeation chromatography. Although the upper limit is not particularly limited, it is preferably 10,000 or less, more preferably 5,000 or less, even more preferably 4,000 or less, and particularly preferably 3,000 or less. Within the above range, the effect tends to be obtained more favorably.

In the present specification, Mw is measured by GPC (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). It can be calculated by polystyrene conversion.

From the viewpoint of obtaining a better effect, the vegetable oil has a peak area occupied by components with a molecular weight of 800 or more in the molecular weight distribution curve obtained by the GPC method (ratio of components with a molecular weight of 800 or more in the molecular weight distribution curve). is preferably 90% or more. The peak area is more preferably 95% or more, still more preferably 97% or more, particularly preferably 98% or more, and may be 100%.

The vegetable oil has absorbance at wavelengths of 450 nm and 600 nm measured with a spectrophotometer of the diluted vegetable oil diluted 3 times with THF (tetrahydrofuran) absorbance at wavelengths of 450 nm and 600 nm) satisfies the following formula (condition (3)).
Absorbance at wavelength 450 nm - Absorbance at wavelength 600 nm ≥ 0.05
The absorbance at a wavelength of 450 nm−the absorbance at a wavelength of 600 nm is preferably 0.10 or more, more preferably 0.20 or more, even more preferably 0.30 or more, and particularly preferably 0.35 or more. The upper limit is preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.70 or less, and particularly preferably 0.60 or less. Within the above range, the effect tends to be obtained more favorably.

The absorbance at a wavelength of 450 nm measured with the spectrophotometer is preferably 0.10 or higher, more preferably 0.20 or higher, still more preferably 0.30 or higher, and particularly preferably 0.40 or higher. The upper limit is preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.70 or less, and particularly preferably 0.60 or less. Within the above range, the effect tends to be obtained more favorably.

In addition, in this specification, the absorbance of vegetable oil can be measured with an ultraviolet-visible spectrophotometer, for example. Specifically, it can be measured by the method described in Examples.

Regarding the vegetable oil, the weight (g) before passing 100 g of vegetable oil at a temperature of 23 to 30 ° C. through a 20-mesh plain-woven wire mesh and the weight (g) after passing through a 20-mesh plain-woven wire mesh satisfy the following formula (condition (4)).
(Weight after passing through plain weave wire mesh / Weight before passing through plain weave wire mesh) × 100 ≥ 99.0
(Weight after passing through plain-woven wire mesh/weight before passing through plain-woven wire mesh) × 100 is preferably 99.3% or more, more preferably 99.5% or more, still more preferably 99.7% or more, and particularly preferably is 99.8% or more, and may be 100%. Within the above range, the effect tends to be obtained more favorably.
The plain-woven wire mesh refers to a wire mesh in which vertical lines and horizontal lines are intersected one by one while maintaining a constant interval.

Waste edible oil (waste edible vegetable oil) can be suitably used as the vegetable oil from the viewpoint of obtaining better effects.

Although the mechanism by which such action and effect are obtained is not necessarily clear, it is presumed that the following actions and functions are exhibited.
Waste cooking oil interacts with fillers such as carbon black by conjugating double bonds with carbonyls, and the reduction of double bonds in this way lowers the Tg of vegetable oil and lowers tan δ. Therefore, it is thought that fuel efficiency is improved. In addition, by using waste cooking oil, it is possible to reduce the amount of _CO2 emitted during the production and transportation of raw materials, so it has excellent LCA performance. Therefore, it is presumed that the rubber composition is excellent in overall performance of fuel economy and bleeding resistance, and also has good LCA performance (reduction of _CO2 emissions, etc.).

As the waste cooking oil, general vegetable oil used as cooking oil, which has been used for cooking with heat and whose quality has deteriorated, can be used. The waste edible oil may contain oils and fats derived from cooked foods, their decomposition/denatured products, and the like.

Specifically, soybean oil, rapeseed oil, cottonseed oil, sunflower oil, kapok oil, sesame oil, corn oil, rice oil, peanut oil, safflower oil, olive oil, linseed oil, paulownia oil, castor oil, palm oil, palm kernel oil , coconut oil, etc., and those whose quality has deteriorated due to the use of these mixtures for cooking.

These waste edible oils are usually disposed of using vegetable oils consisting of esters of fatty acids and glycerin. Here, the number of carbon atoms of the fatty acid is preferably in the range of 6 to 24, and each molecule may contain 0 to 3 unsaturated bonds. Specific examples of fatty acids include caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanic acid, arachidic acid, behenic acid, and lignoserine. Saturated fatty acids such as acid; succinic acid, lindelic acid, thuzunic acid, myristoleic acid, palmitoleic acid, petroselinic acid, oleic acid, elaidic acid, vaccenic acid, erucic acid, sorbic acid, linoleic acid, linoleic acid, γ- Examples include unsaturated fatty acids such as linolenic acid, linolenic acid, arachidonic acid, and mixtures thereof.

In the rubber composition, the content of the vegetable oil is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and particularly preferably 7 parts by mass with respect to 100 parts by mass of the rubber component. Department or above. The upper limit is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, still more preferably 80 parts by mass or less, particularly preferably 70 parts by mass or less, and most preferably 50 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

(rubber component)
Examples of rubber components that can be used in the rubber composition include isoprene rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR). , and other diene rubbers such as styrene-isoprene-butadiene copolymer rubber (SIBR). Among them, isoprene-based rubber, BR, and SBR are preferable.

Each rubber component may be an unmodified rubber or a modified rubber.
Modified rubbers include rubbers having functional groups that interact with fillers such as silica and carbon black. Specifically, at least one end of the rubber is modified with a compound (modifier) having the above functional group (terminally modified rubber having the above functional group at the end), or the above functional group on the main chain and a main chain end-modified rubber having the above functional group on the main chain and the end (for example, a main chain having the above functional group on the main chain and at least one end modified with the above modifier terminal rubber), and terminal-modified rubber modified (coupling) with a polyfunctional compound having two or more epoxy groups in the molecule to introduce a hydroxyl group or an epoxy group. These may be used alone or in combination of two or more.

Examples of the functional group include functional groups containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a silicon atom. These may be used alone or in combination of two or more.

Examples of the functional groups include amino group, amido group, silyl group, alkoxysilyl group, isocyanate group, imino group, imidazole group, urea group, ether group, carbonyl group, oxycarbonyl group, mercapto group, sulfide group, disulfide group, sulfonyl group, sulfinyl group, thiocarbonyl group, ammonium group, imide group, hydrazo group, azo group, diazo group, carboxyl group, nitrile group, pyridyl group, alkoxy group, hydroxyl group, oxy group, epoxy group and the like. . In addition, these functional groups may have a substituent. Among them, amino group (preferably an amino group in which the hydrogen atom of the amino group is substituted with an alkyl group having 1 to 6 carbon atoms), alkoxy group (preferably 1 carbon atom 6 alkoxy groups) and alkoxysilyl groups (preferably alkoxysilyl groups having 1 to 6 carbon atoms) are preferred.

The isoprene rubber includes natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, modified IR, and the like. NR may be SIR20, RSS#3, TSR20, etc., and IR may be IR2200, etc., which are commonly used in the tire industry. Modified NR includes deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc. Modified NR includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc., modified IR Examples include epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, and the like. These may be used alone or in combination of two or more.

When the rubber composition contains an isoprene-based rubber, the content of the isoprene-based rubber in 100% by mass of the rubber component is preferably 30% by mass or more, more preferably 40% by mass or more, and still more preferably 45% by mass or more. is. Although the upper limit of the content is not particularly limited, it is preferably 90% by mass or less, more preferably 75% by mass or less, and still more preferably 60% by mass or less. Within the above range, the effect tends to be obtained more favorably.

The BR is not particularly limited. BR), tin-modified butadiene rubber modified with a tin compound (tin-modified BR), and the like, which are commonly used in the tire industry. Commercially available BR products of Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Zeon Corporation, etc. can be used. These may be used alone or in combination of two or more.

Both non-denatured BR and denatured BR can be used as BR.
Examples of modified BR include BR having the above functional groups.

From the viewpoint of performance on ice, the cis content of BR is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more. In this specification, the cis content (cis-1,4-bond amount) is a value calculated from signal intensity measured by infrared absorption spectroscopy or NMR analysis.

When the rubber composition contains BR, the content of BR in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 40% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. Within the above range, the effect tends to be obtained more favorably.

The SBR is not particularly limited, and for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc. can be used. These may be used alone or in combination of two or more.

The styrene content of SBR is preferably 5.0% by mass or more, more preferably 10.0% by mass or more, still more preferably 15.0% by mass or more, and particularly preferably 20.0% by mass or more. The upper limit of the styrene content is preferably 60.0% by mass or less, more preferably 50.0% by mass or less, still more preferably 40.0% by mass or less, and particularly preferably 30.0% by mass or less. . Within the above range, the effect tends to be obtained more favorably.
In this specification, the styrene content of SBR is calculated by ¹ H-NMR measurement.

The vinyl content of SBR is preferably 5.0% by mass or more, more preferably 10.0% by mass or more, still more preferably 12.0% by mass or more, and particularly preferably 14.0% by mass or more. The vinyl content is preferably 50.0% by mass or less, more preferably 30.0% by mass or less, still more preferably 20.0% by mass or less, and particularly preferably 18.0% by mass or less. Within the above range, the effect tends to be obtained more favorably.
The vinyl content (1,2-bonded butadiene unit amount) can be measured by infrared absorption spectrometry.

As SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Co., Ltd., Asahi Kasei Co., Ltd., Nippon Zeon Co., Ltd., etc. can be used.

SBR may be unmodified SBR or modified SBR.
Examples of modified SBR include SBR having the above functional groups.

When the rubber composition contains SBR, the content of SBR in 100% by mass of the rubber component is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more, and , preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less. Within the above range, the effect tends to be obtained more favorably.

(filler)
The rubber composition desirably contains a filler.
The filler is not particularly limited, and materials known in the rubber field can be used. Examples thereof include inorganic fillers such as carbon black, silica, calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, and mica. be done. Among them, carbon black and silica are preferred.

In the rubber composition, the content of fillers (total content of fillers) is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, and still more preferably 30 parts by mass with respect to 100 parts by mass of the rubber component. parts or more, particularly preferably 40 parts by mass or more. The upper limit of the content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, even more preferably 100 parts by mass or less, and particularly preferably 90 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

Examples of carbon black that can be used in the rubber composition include, but are not limited to, N134, N110, N220, N234, N219, N339, N330, N326, N351, N550 and N762. As commercially available products, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Co., Ltd., Lion Corporation, Nippon Steel Carbon Co., Ltd., Columbia Carbon Co., etc. can be used. . These may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 20 m ² /g or more, more preferably 30 m ² /g or more, and even more preferably 40 m ² /g or more. The N ₂ SA is preferably 200 m ² /g or less, more preferably 150 m ² /g or less, and even more preferably 130 m ² /g or less. Within the above range, the effect tends to be obtained more favorably.
The nitrogen adsorption specific surface area of carbon black is determined according to JIS K6217-2:2001.

In the rubber composition, the content of carbon black is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass with respect to 100 parts by mass of the rubber component. Department or above. The upper limit is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

Silica is not particularly limited, and examples thereof include dry silica (anhydrous silicic acid) and wet silica (hydrous silicic acid). These may be used alone or in combination of two or more. Among them, wet-process silica is preferable because it has many silanol groups.

As silica, for example, products of Degussa, Rhodia, Tosoh Silica, Solvay Japan, Tokuyama, etc. can be used.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 50 m ² /g or more, more preferably 100 m ² /g or more, still more preferably 150 m ² /g or more. Also, the N ₂ SA is preferably 300 m ² /g or less, more preferably 250 m ² /g or less, still more preferably 230 m ² /g or less. Within the above range, the effect tends to be obtained more favorably.
The N ₂ SA of silica can be measured according to ASTM D3037-81.

In the rubber composition, the content of silica is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass with respect to 100 parts by mass of the rubber component. That's it. The upper limit is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

(Silane coupling agent)
The rubber composition preferably contains a silane coupling agent.
The silane coupling agent is not particularly limited, and examples thereof include bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, Bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (2-triethoxysilylethyl) trisulfide, 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, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3- sulfides such as triethoxysilylpropyl methacrylate monosulfide; 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane; vinyl-based such as methoxysilane; amino-based such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. These may be used alone or in combination of two or more. Among them, sulfide-based and mercapto-based are preferable because they are more effective.

Examples of silane coupling agents that can be used include products of Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azmax Co., Ltd., Dow Corning Toray Co., Ltd., and the like.

The content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, preferably 25 parts by mass or less, and more preferably 20 parts by mass or less, relative to 100 parts by mass of the silica. 15 parts by mass or less is more preferable. Within the above range, the effect tends to be obtained more favorably.

(other plasticizers)
The rubber composition may contain other plasticizers in addition to the vegetable oil.
Other plasticizers include, for example, liquid plasticizers (plasticizers in liquid state at 23° C.) other than the vegetable oils, resins (resin in solid state at 23° C.), and the like.

In the rubber composition, the content of the plasticizer (total amount of plasticizer) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more with respect to 100 parts by mass of the rubber component. , particularly preferably 7 parts by mass or more. The upper limit is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, even more preferably 80 parts by mass or less, and particularly preferably 70 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

The liquid plasticizer (plasticizer in liquid state at 23 ° C.) other than the vegetable oil is not particularly limited, and includes process oil, liquid polymer (liquid resin, liquid diene polymer, liquid farnesene polymer, etc.), vegetable oil other than the vegetable oil. etc. These may be used alone or in combination of two or more.

In the rubber composition, the content of the liquid plasticizer (total amount of the liquid plasticizer) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass with respect to 100 parts by mass of the rubber component. parts or more, particularly preferably 7 parts by mass or more. The upper limit is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, even more preferably 80 parts by mass or less, and particularly preferably 70 parts by mass or less. Within the above range, the effect tends to be obtained more favorably. The content of the liquid plasticizer also includes the amount of oil contained in the oil-extended rubber.

As the process oil, for example, paraffinic process oil, aromatic process oil, naphthenic process oil, etc. can be used. Commercially available products include Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., ENEOS Co., Ltd., Orisoi Co., Ltd., H&R Co., Ltd., Toyokuni Oil Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kosan Co., Ltd., Japan Products such as Sei Oillio Group Co., Ltd. can be used.

Liquid resins include liquid terpene resins (including terpene phenolic resins and aromatic modified terpene resins), rosin resins, styrene resins, C5 resins, C9 resins, C5/C9 resins, dicyclopentadiene (DCPD ) resins, coumarone-indene resins (including coumarone and indene single resins), phenol resins, olefin resins, polyurethane resins, acrylic resins, and the like. Hydrogenated products of these can also be used.

Examples of the liquid diene-based polymer include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), liquid styrene-isoprene copolymer (liquid SIR), liquid styrene butadiene styrene block copolymer (liquid SBS block polymer), liquid styrene isoprene styrene block copolymer (liquid SIS block polymer), liquid farnesene polymer, liquid farnesene butadiene copolymer, and the like. . These may be modified with a polar group at the terminal or main chain. Hydrogenated products of these can also be used.

Examples of the resins (resins in a solid state at 23°C) that can be used in the rubber composition include aromatic vinyl polymers in a solid state at 23°C, coumarone-indene resins, coumarone resins, indene resins, phenolic resins, and rosin. Resins, petroleum resins, terpene-based resins, acrylic-based resins, and the like. Also, the resin may be hydrogenated. These may be used alone or in combination of two or more. Among them, aromatic vinyl polymers, petroleum resins, and terpene resins are preferred.

In the rubber composition, the content of the resin is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass with respect to 100 parts by mass of the rubber component. That's it. The upper limit is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

The softening point of the resin is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. The upper limit is preferably 160°C or lower, more preferably 150°C or lower, and even more preferably 145°C or lower. Within the above range, the effect tends to be obtained more favorably. The softening point of the resin is the temperature at which the ball descends when the softening point specified in JIS K6220-1:2001 is measured with a ring and ball type softening point measuring device.

The aromatic vinyl polymer is a polymer containing an aromatic vinyl monomer as a structural unit. Examples thereof include α-methylstyrene and/or resins obtained by polymerizing styrene. Specifically, styrene homopolymers (styrene resins), α-methylstyrene homopolymers (α-methylstyrene resins ), copolymers of α-methylstyrene and styrene, and copolymers of styrene and other monomers.

The coumarone-indene resin is a resin containing coumarone and indene as main monomer components constituting the skeleton (main chain) of the resin. Examples of monomer components contained in the skeleton other than coumarone and indene include styrene, α-methylstyrene, methylindene, and vinyltoluene.

The coumarone resin is a resin containing coumarone as a main monomer component that constitutes the skeleton (main chain) of the resin.

The indene resin is a resin containing indene as a main monomer component that constitutes the skeleton (main chain) of the resin.

As the phenolic resin, for example, known polymers obtained by reacting phenol with aldehydes such as formaldehyde, acetaldehyde and furfural with an acid or alkali catalyst can be used. Among them, those obtained by reacting with an acid catalyst (such as novolac phenolic resins) are preferable.

Examples of the rosin resin include natural rosin, polymerized rosin, modified rosin, ester compounds thereof, and rosin-based resins represented by hydrogenated products thereof.

Examples of the petroleum resins include C5-based resins, C9-based resins, C5/C9-based resins, dicyclopentadiene (DCPD) resins, and hydrogenated products thereof. Among them, DCPD resin and hydrogenated DCPD resin are preferable.

The terpene-based resin is a polymer containing terpene as a structural unit. Examples thereof include polyterpene resins obtained by polymerizing terpene compounds, and aromatic modified terpene resins obtained by polymerizing terpene compounds and aromatic compounds. Aromatic modified terpene resins include terpene phenol resins made from terpene compounds and phenol compounds, terpene styrene resins made from terpene compounds and styrene compounds, and terpene compounds, phenol compounds and styrene compounds as raw materials. Terpene phenol styrene resins can also be used. The terpene compounds include α-pinene and β-pinene, the phenolic compounds include phenol and bisphenol A, and the aromatic compounds include styrene compounds (styrene, α-methylstyrene, etc.).

The acrylic resin is a polymer containing an acrylic monomer as a structural unit. Examples thereof include styrene-acrylic resins such as styrene-acrylic resins, which have a carboxyl group and are obtained by copolymerizing an aromatic vinyl monomer component and an acrylic monomer component. Among them, solvent-free carboxyl group-containing styrene-acrylic resins can be preferably used.

Examples of plasticizers include Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical, Nichinuri Chemical Co., Ltd. Products of Nippon Shokubai, ENEOS Co., Ltd., Arakawa Chemical Co., Ltd., Taoka Chemical Co., Ltd., etc. can be used.

(other materials)
The rubber composition preferably contains sulfur.
Sulfur includes powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur and the like commonly used in the rubber industry. These may be used alone or in combination of two or more.

As sulfur, for example, products of Tsurumi Chemical Industry Co., Ltd., Karuizawa Io Co., Ltd., Shikoku Kasei Kogyo Co., Ltd., Flexis Co., Ltd., Nippon Kantan Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

The sulfur content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and still more preferably 0.8 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, even more preferably 5 parts by mass or less, particularly preferably 3 parts by mass or less, and most preferably 2 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

The rubber composition preferably contains a vulcanization accelerator.
Vulcanization accelerators include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), tetrakis (2 -ethylhexyl) thiuram-based vulcanization accelerators such as thiuram disulfide (TOT-N); N-cyclohexyl-2-benzothiazolylsulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxy Sulfenamide-based vulcanization accelerators such as ethylene-2-benzothiazolesulfenamide and N,N'-diisopropyl-2-benzothiazolesulfenamide; guanidines such as diphenylguanidine, diorthotolylguanidine and orthotolylbiguanidine system vulcanization accelerators. These may be used alone or in combination of two or more. Among them, a sulfenamide-based vulcanization accelerator is preferable.

As the vulcanization accelerator, for example, products manufactured by Kawaguchi Kagaku Co., Ltd., Ouchi Shinko Kagaku Co., Ltd., Rhein Chemie Co., etc. can be used.

The content of the vulcanization accelerator is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass, based on 100 parts by mass of the rubber component. Part by mass or less. Within the above range, the effect tends to be obtained more favorably.

The rubber composition preferably contains stearic acid.
As the stearic acid, conventionally known ones can be used, for example, products of NOF Corporation, Kao Corporation, Fuji Film Wako Pure Chemical Industries, Ltd., Chiba Fatty Acids Co., Ltd., etc. can be used.

The stearic acid content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the rubber component. Also, the above content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

The rubber composition may contain zinc oxide.
As the zinc oxide, conventionally known ones can be used, for example, products of Mitsui Kinzoku Mining Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used.

The content of zinc oxide is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass, relative to 100 parts by mass of the rubber component. It is below. Within the above range, the effect tends to be obtained more favorably.

The rubber composition may contain an antioxidant.
Examples of anti-aging agents include naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4′-bis(α,α′-dimethylbenzyl)diphenylamine; -Isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, etc. p-phenylenediamine-based antioxidants; quinoline-based antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; 2,6-di-t-butyl-4-methylphenol, monophenolic anti-aging agents such as styrenated phenol; inhibitors and the like. These may be used alone or in combination of two or more. Among them, p-phenylenediamine anti-aging agents and quinoline anti-aging agents are preferred, and p-phenylenediamine anti-aging agents are more preferred.

As the anti-aging agent, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Kagaku Kogyo Co., Ltd., Flexis, etc. can be used, for example.

The content of the anti-aging agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass, relative to 100 parts by mass of the rubber component. It is below the department. Within the above range, the effect tends to be obtained more favorably.

The rubber composition may contain wax.
The wax is not particularly limited, and includes petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as plant waxes and animal waxes; synthetic waxes such as polymers of ethylene and propylene. These may be used alone or in combination of two or more.

As the wax, for example, products of Ouchi Shinko Kagaku Kogyo Co., Ltd., Nippon Seiro Co., Ltd., Seiko Kagaku Co., Ltd., etc. can be used.

The wax content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the rubber component. Moreover, the content is preferably 10 parts by mass or less, more preferably 7 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

In addition to the above components, the rubber composition may contain additives commonly used in the tire industry, such as vulcanizing agents other than sulfur (e.g., organic cross-linking agents, organic peroxides), etc. can be exemplified. The content of each of these components is preferably 0.1 parts by mass or more and preferably 200 parts by mass or less with respect to 100 parts by mass of the rubber component.

The rubber composition can be produced, for example, by kneading each of the above components using a rubber kneading device such as an open roll mixer or a Banbury mixer, followed by vulcanization.

As for the kneading conditions, the kneading temperature is usually 100 to 180°C, preferably 120 to 170°C in the base kneading step for kneading additives other than the cross-linking agent (vulcanizing agent) and the vulcanization accelerator. In the finishing kneading step of kneading the vulcanizing agent and the vulcanization accelerator, the kneading temperature is usually 120°C or lower, preferably 80 to 110°C. A composition obtained by kneading a vulcanizing agent and a vulcanization accelerator is usually subjected to vulcanization treatment such as press vulcanization. The vulcanization temperature is generally 140-190°C, preferably 150-185°C.

The rubber composition can be used, for example, in tire components (as a rubber composition for tires).
The tire member is not particularly limited, and includes any tire member such as tread (cap tread, base tread), sidewall, bead apex, clinch apex, inner liner, undertread, breaker topping, ply topping, etc. be done. Among them, sidewalls, inner liners and cap treads are preferred, and sidewalls and inner liners are particularly preferred.

The tire of the present invention is manufactured by a conventional method using the above rubber composition. That is, a rubber composition blended with various additives as necessary is extruded in the unvulcanized stage according to the shape of each member of the tire, molded by a usual method on a tire molding machine, After bonding together with other tire members to form an unvulcanized tire, a tire can be manufactured by heating and pressurizing in a vulcanizer.

The tire is not particularly limited, and examples thereof include a pneumatic tire, a solid tire, an airless tire, and the like. Among them, pneumatic tires are preferred.

The tires include tires for passenger cars, tires for large passenger cars, tires for large SUVs, tires for heavy loads (tires for trucks and buses, etc.), tires for motorcycles, tires for competition, winter tires (studless tires, snow tires, low-temperature road surfaces). tires, stud tires), all-season tires, run-flat tires, aircraft tires, mining tires, etc.

EXAMPLES The present invention will be specifically described based on Examples, but the present invention is not limited to these.

Various chemicals used in Examples and Comparative Examples are collectively described below.
NR: RSS#3
BR: Polybutadiene rubber UBEPOL BR150B manufactured by Ube Industries, Ltd. (cis content: 97% by mass, ML ₁₊₄ (100°C): 40, Mw/Mn: 3.3)
Carbon black: SEAST N550 (N ₂ SA: 41 m ² /g) manufactured by Mitsubishi Chemical Corporation
Silica: Ultrasil VN3 from EVONIK-DEGUSSA (N ₂ SA: 175 m ² /g)
Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by EVONIK-DEGUSSA
Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd.
Anti-aging agent: Nocrac 6C (N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vegetable oils 1 to 8: Waste edible oil Mineral oil having the properties shown in Table 1: PS-32 manufactured by Idemitsu Kosan Co., Ltd.
Vegetable oil 9: Vegetable oil (new) with the properties listed in Table 1
Stearic acid: NOF Co., Ltd. stearic acid "Paulownia"
Zinc oxide: Mitsui Kinzoku Kogyo Co., Ltd. zinc oxide Class 2 Sulfur: Tsurumi Chemical Industry Co., Ltd. powdered sulfur Vulcanization accelerator: Ouchi Shinko Kagaku Co., Ltd. Noccellar NS (N-tert-butyl-2-benzothiazol rusulfenamide)

The molecular weight and absorbance of vegetable oil were measured by the following methods. The weight before and after passing through a 20 mesh plain weave wire mesh is the weight before and after passing 100 g of vegetable oil at a temperature of 23 to 30° C. through a 20 mesh plain weave wire mesh.

<Molecular weight analysis>
The weight average molecular weight Mw of the vegetable oil is measured by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). Based on the value, it was determined as a standard polystyrene conversion value. Also, using the molecular weight distribution curve obtained by GPC, the peak area occupied by components having a molecular weight of 800 or more was determined.

<Absorbance measurement>
Using a spectrophotometer (manufactured by Thermo SCIENTIFIC), absorbance at 450 nm and 600 nm of a sample (diluted vegetable oil) obtained by diluting 100 μL of vegetable oil 3 times with 200 μL of THF was measured, and the absorbance at wavelength 450 nm - absorbance at wavelength 600 nm. was calculated.

<Production of vulcanized rubber composition and test tires>
Chemicals other than sulfur and a vulcanization accelerator were kneaded using a 1.7 L Banbury mixer according to the formulation shown in Table 2. Next, using an open roll, sulfur and a vulcanization accelerator were added to the resulting kneaded material and kneaded to obtain an unvulcanized rubber composition. Next, the obtained unvulcanized rubber composition was press-vulcanized at 170° C. for 15 minutes in a mold having a thickness of 2 mm to obtain a vulcanized rubber composition (vulcanized rubber sheet).
Further, the obtained unvulcanized rubber composition was molded into a sidewall shape, bonded to another tire member, and vulcanized at 170° C. for 15 minutes to prepare a test tire.

The vulcanized rubber compositions and test tires were evaluated as follows, and the results are shown in Table 2. Comparative Example 1 was used as the reference comparative example in Table 2.

<Viscoelasticity test (fuel efficiency)>
Using a viscoelastic spectrometer VES manufactured by Iwamoto Seisakusho Co., Ltd., the loss tangent (tan δ) of the vulcanized rubber slab sheet was measured under conditions of a temperature of 70°C, an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz. Assuming that the rolling resistance index of the reference comparative example was 100, the rolling resistance was expressed as an index according to the following formula. A higher rolling resistance index indicates lower rolling resistance and better fuel efficiency.
(Rolling resistance index) = (tan δ of reference comparative example) / (tan δ of each formulation) x 100

<Bleed resistance>
After mounting the test tire on the vehicle and running it for 8000 km, the amount of acetone extracted from the sidewall rubber of the test tire was measured, and the reciprocal of (the amount of acetone extracted before running - the amount of acetone extracted after running) was calculated. , and expressed as an index when the reference comparative example is set to 100 (bleed resistance index). The larger the index, the more suppressed the bleeding and the better the bleeding resistance.

<LCA performance>
The LCA performance was evaluated according to the following three-stage criteria.
○: CO ₂ emissions can be greatly reduced.
△: CO ₂ emissions can be reduced.
x: A large amount of CO ₂ is emitted.

From Tables 1 and 2, it can be seen that the rubber compositions of Examples containing vegetable oils satisfying the above conditions (1) to (4) have a comprehensive performance of fuel efficiency and bleed resistance (two of fuel efficiency and bleed resistance). (expressed by the sum of indices) and the LCA performance was also good.

The present invention (1) is a rubber composition containing vegetable oil that satisfies the following conditions (1) to (4).
(1) It is in a liquid state at a temperature of 23°C.
(2) Weight average molecular weight exceeding 800 by GPC method.
(3) The diluted vegetable oil diluted 3-fold with THF has absorbance at wavelengths of 450 nm and 600 nm measured with a spectrophotometer that satisfies the following formula.
Absorbance at wavelength 450 nm - Absorbance at wavelength 600 nm ≥ 0.05
(4) The weight before and after passing 100 g of vegetable oil at a temperature of 23 to 30° C. through a 20-mesh plain-woven wire mesh satisfies the following formula.
(Weight after passing through plain weave wire mesh / Weight before passing through plain weave wire mesh) × 100 ≥ 99.0

The present invention (2) is the rubber composition according to the present invention (1), wherein the vegetable oil has a peak area of 95% or more at molecular weights of 800 or more in a molecular weight distribution curve by GPC method.

Present invention (3) is the rubber composition according to present invention (1) or (2), wherein the vegetable oil is waste edible oil.

The present invention (4) is the rubber composition according to any one of the present inventions (1) to (3), wherein the content of the vegetable oil is 1 to 100 parts by mass with respect to 100 parts by mass of the rubber component.

The present invention (5) is the rubber composition according to any one of the present inventions (1) to (4), which is a sidewall rubber composition and/or an innerliner rubber composition.

Invention (6) is a tire using the rubber composition according to any one of Inventions (1) to (5).

Claims (6)

A rubber composition containing vegetable oil that satisfies the following conditions (1) to (4).
(1) It is in a liquid state at a temperature of 23°C.
(2) Weight average molecular weight exceeding 800 by GPC method.
(3) The diluted vegetable oil diluted 3-fold with THF has absorbance at wavelengths of 450 nm and 600 nm measured with a spectrophotometer that satisfies the following formula.
Absorbance at wavelength 450 nm - Absorbance at wavelength 600 nm ≥ 0.05
(4) The weight before and after passing 100 g of vegetable oil at a temperature of 23 to 30° C. through a 20-mesh plain-woven wire mesh satisfies the following formula.
(Weight after passing through plain weave wire mesh / Weight before passing through plain weave wire mesh) × 100 ≥ 99.0 2. The rubber composition according to claim 1, wherein the vegetable oil has a peak area of 95% or more at molecular weights of 800 or more in a molecular weight distribution curve by GPC method. 3. The rubber composition according to claim 1, wherein said vegetable oil is waste cooking oil. 3. The rubber composition according to claim 1, wherein the content of said vegetable oil is 1 to 100 parts by mass with respect to 100 parts by mass of the rubber component. 3. The rubber composition according to claim 1, which is a sidewall rubber composition and/or an innerliner rubber composition. A tire using the rubber composition according to claim 1 or 2.