Method for producing rubber composition

Abstract

To provide a method for producing a rubber composition capable of suppressing batch-to-batch variations caused on temperature, viscosity, state of texture or the like of the rubber composition after kneading.SOLUTION: There is provided a method for producing a rubber composition, which performs batch kneading of a rubber component 3 and an additive in a kneading machine 2 equipped with a rotor R, and which comprises steps of: (1) measuring a temperature of a rubber component just before putting into the kneading machine and an outside air temperature; (2) calculating a displacement amount R1 and a displacement amount T1 to be displaced according to a temperature of the rubber component, and calculating a displacement amount R2 and a displacement amount T2 to be displaced according to an outside temperature regarding a rotor rotation speed and kneading time with respect to a preset rotor rotation speed reference value R0 and a kneading time reference value T0; (3) determining a rotor speed RV corrected based on the R0, R1 and R2, and determining a kneading time TV corrected based on the T0, T1 and T2; and (4) performing kneading by the corrected RV and the corrected TV.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing a rubber composition, a method for producing a tire, and a kneading device, and more specifically to a method for producing a rubber composition in which a rubber component and an additive are batch-kneaded in a kneading device equipped with a rotor, a method for producing a tire using an unvulcanized rubber composition obtained by a production method including the above-mentioned production method, and a kneading device. [Background technology]

[0002] Banbury mixers, kneaders, open rolls, and the like are commonly used as kneading machines for dispersing and kneading various additives into rubber components. When batch kneading a rubber composition using such a kneading machine, it is important to minimize variations in properties (e.g., temperature, viscosity, dispersion state of chemicals, etc.) between batches. Patent Document 1 describes a rubber kneading method in which, when kneading rubber, the temperature of the rubber immediately before being supplied to a rubber kneading machine is detected for each batch, and at least one of the standard amount of power supplied to the rubber kneading machine and the standard kneading time is adjusted according to the detected temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-24412 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when kneading the rubber component, although it is true that the temperature of the raw rubber component immediately before being fed into the kneader affects the properties of the kneaded rubber composition, it is difficult to sufficiently suppress the variation between batches by adjusting the temperature alone. Furthermore, the adjustment method is also insufficient by adjusting the amount of electricity and the kneading time alone. For this reason, it is not possible to sufficiently suppress the variation in the temperature, viscosity, and texture of the rubber composition after kneading, and a method for further improvement is desired.

[0005] In particular, in the summer when the outside air temperature is high, the temperature of the mixture of the rubber component and various additives tends to rise at the end of mixing. In particular, when mixing the rubber component with silica and a silane coupling agent, the high outside air temperature can cause the coupling reaction to proceed excessively, resulting in gelation and poor sheet texture.

[0006] The present disclosure aims to provide a method for producing a rubber composition that can reduce batch-to-batch variations in the temperature, viscosity, and dough state of the rubber composition after kneading, a method for producing a tire using the rubber composition produced by the production method, and a kneading device for producing a rubber composition by the production method. [Means for solving the problem]

[0007] As a result of extensive research to solve the above-mentioned problems, the present inventors have found that if the temperature of the rubber component and the ambient temperature are measured immediately before being put into a kneading machine, and the deviation amount from a preset reference value of the rotor rotation speed and the kneading time is calculated based on the results, and kneading is carried out at a rotor rotation speed and a kneading time corrected by taking into account the deviation amount, it is possible to suppress variation in the properties of the kneaded rubber composition between batches. After further research, the present inventors have completed the present disclosure.

[0008] That is, the present disclosure: [1] A method for producing a rubber composition, The rubber component and the additives are batch-kneaded in a kneader equipped with a rotor, (1) a step of measuring the temperature of the rubber component and the ambient temperature immediately before being charged into the kneader; (2) calculating a displacement R1 and a displacement T1 that should be displaced in accordance with the temperature of the rubber component with respect to at least a rotor rotation speed and a kneading time, respectively, relative to a preset reference value R0 of the rotor rotation speed and a preset reference value T0 of the kneading time, and calculating a displacement R2 and a displacement T2 that should be displaced in accordance with the ambient air temperature; (3) The rotor rotation speed R corrected based on the reference value R0, the displacement amount R1, and the displacement amount R2. V and determining a kneading time T corrected based on the reference value T0, the displacement amount T1, and the displacement amount T2. V determining the (4) The corrected rotor rotation speed R V and the corrected kneading time T V and kneading the mixture. A method for producing a rubber composition comprising: [2] The displacement R1 satisfies the following relationship depending on the temperature of the rubber component, When the temperature of the rubber component is below 20°C, R1>0 When the temperature of the rubber component is between 20°C and 35°C, R1=0 When the temperature of the rubber component is above 35°C, R1<0 The displacement amount R2 satisfies the following relationship depending on the outside air temperature: When the outside temperature is below 20°C, R2>0 When the outside temperature is between 20℃ and 35℃, R2=0 When the outside temperature is over 35°C, R2<0 The manufacturing method according to [1] above, [3] The displacement amount T1 satisfies the following relationship depending on the temperature of the rubber component, When the temperature of the rubber component is below 20°C, T1<0 When the temperature of the rubber component is between 20°C and 35°C, T1=0 When the temperature of the rubber component is above 35°C, T1>0 The displacement amount T2 satisfies the following relationship depending on the outside air temperature: When the outside temperature is below 20°C, T2<0 When the outside temperature is between 20℃ and 35℃, T2=0 When the outside temperature is above 35°C, T2>0 The manufacturing method according to the above [1] or [2] [4] The step (2) further includes a step of calculating a displacement amount W1 that should be displaced in accordance with the temperature of the rubber component from a preset reference value W0 of the amount of electric power, and calculating a displacement amount W2 that should be displaced in accordance with the outside air temperature, The step (3) further includes: the reference value W0; the displacement amount W1; and and the amount of power W corrected from the displacement W2 V determining The step (4) calculates the corrected amount of power W V The manufacturing method according to any one of the above [1] to [3], wherein batch mixing is carried out while further taking into consideration the above. [5] The method according to any one of the above [1] to [4], wherein the additive contains silica. [6] The manufacturing method according to any one of the above [1] to [5], wherein the additives are chemicals other than vulcanization-related chemicals. [7] A method for manufacturing a tire, comprising: A step of producing an unvulcanized rubber composition by a production method including the production method described in any one of [1] to [6] above; and A step of manufacturing a tire using the unvulcanized rubber composition by a conventional method. a manufacturing method comprising: [8] A kneading apparatus for batch kneading a rubber composition, The present invention comprises a kneading machine having a rotor R, a means D1 for detecting the temperature of a rubber component, a means D2 for detecting the ambient air temperature, a calculation means C for calculating the amount of displacement, and an operation control means O for controlling the operation of the kneading machine, The detection means D1 detects the temperature of the rubber component immediately before being fed into the kneader and transmits the detected temperature as an electric signal to the calculation means C, The detection means D2 detects the outside air temperature immediately before the material is fed into the kneader, and transmits the detected temperature as an electric signal to the calculation means C. the calculation means C calculates, with respect to at least the rotor rotation speed and the kneading time, a displacement R1 and a displacement T1 to be displaced, respectively, in accordance with the received electrical signal corresponding to the temperature of the rubber component, with respect to a preset reference value R0 of the rotor rotation speed and a preset reference value T0 of the kneading time, and calculates a displacement R2 and a displacement T2 to be displaced, respectively, in accordance with the received electrical signal corresponding to the outside air temperature, and transmits the electrical signals corresponding to each displacement to the operation control means O; The operation control means O calculates the rotor rotation speed R corrected based on the reference value R0, the displacement amount R1, and the displacement amount R2. V is determined, and the rotor rotation speed R V and transmitting an electrical signal corresponding to the reference value T0, the displacement amount T1, and the displacement amount T2 to the kneading machine. V is determined, and the kneading time T V and transmits an electrical signal corresponding to the The kneader receives the rotor rotation speed R V and the kneading time T V A kneading device that performs kneading in accordance with an electrical signal corresponding to Regarding. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a method for producing a rubber composition that can reduce batch-to-batch variations in the temperature, viscosity, dough state, etc. of the rubber composition after kneading, a method for producing a tire using the rubber composition produced by the production method, and a kneading device for producing a rubber composition by the production method. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram of a kneading device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] One embodiment is a method for producing a rubber composition, The rubber component and the additives are batch-kneaded in a kneader equipped with a rotor, (1) a step of measuring the temperature of the rubber component and the ambient temperature immediately before being charged into the kneader; (2) calculating a displacement R1 and a displacement T1 that should be displaced in accordance with the temperature of the rubber component with respect to at least a rotor rotation speed and a kneading time, respectively, relative to a preset reference value R0 of the rotor rotation speed and a preset reference value T0 of the kneading time, and calculating a displacement R2 and a displacement T2 that should be displaced in accordance with the ambient air temperature; (3) The rotor rotation speed R corrected based on the reference value R0, the displacement amount R1, and the displacement amount R2. V and determining a kneading time T corrected based on the reference value T0, the displacement amount T1, and the displacement amount T2. V determining the (4) The corrected rotor rotation speed R V and the corrected kneading time T V and kneading the mixture. A method for producing a rubber composition comprising the steps of:

[0012] The displacement R1 satisfies the following relationship depending on the temperature of the rubber component, When the temperature of the rubber component is below 20°C, R1>0 When the temperature of the rubber component is between 20°C and 35°C, R1=0 When the temperature of the rubber component is above 35°C, R1<0 It is preferable that the displacement R2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, R2>0 When the outside temperature is between 20℃ and 35℃, R2=0 When the outside temperature is over 35°C, R2<0

[0013] The displacement amount T1 satisfies the following relationship depending on the temperature of the rubber component, When the temperature of the rubber component is below 20°C, T1<0 When the temperature of the rubber component is between 20°C and 35°C, T1=0 When the temperature of the rubber component is above 35°C, T1>0 It is preferable that the displacement amount T2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, T2<0 When the outside temperature is between 20℃ and 35℃, T2=0 When the outside temperature is above 35°C, T2>0

[0014] The step (2) further includes a step of calculating, with respect to the amount of electric power, a displacement amount W1 that should be displaced in accordance with the temperature of the rubber component from a preset reference value W0 of the amount of electric power, and calculating a displacement amount W2 that should be displaced in accordance with the outside air temperature, The step (3) further calculates the amount of power W corrected from the reference value W0, the amount of displacement W1, and the amount of displacement W2. V determining The step (4) calculates the corrected amount of power W V It is preferable that the batch kneading is carried out in addition to the above.

[0015] The additive preferably includes silica.

[0016] The additives are preferably chemicals other than vulcanization chemicals.

[0017] Another embodiment is a method for manufacturing a tire, the method comprising the steps of manufacturing an unvulcanized rubber composition by a manufacturing method including the above-described manufacturing method, and manufacturing a tire using the unvulcanized rubber composition by a conventional method.

[0018] Another embodiment is a kneading device for batch kneading a rubber composition, comprising a kneader equipped with a rotor R, a means D1 for detecting the temperature of a rubber component, a means D2 for detecting an outside air temperature, a calculation means C for calculating a displacement amount, and an operation control means O for controlling the operation of the kneader, wherein the detection means D1 detects the temperature of the rubber component immediately before being introduced into the kneader and transmits the detected temperature to the calculation means C as an electric signal, and the detection means D2 detects the outside air temperature immediately before being introduced into the kneader and transmits the detected temperature to the calculation means C as an electric signal, and the calculation means C is configured to calculate at least With respect to at least the rotor rotation speed and kneading time, the control unit 10 calculates a displacement R1 and a displacement T1 to be displaced, respectively, in accordance with the received electric signal corresponding to the temperature of the rubber component, with respect to a preset reference value R0 of the rotor rotation speed and a reference value T0 of the kneading time, and calculates a displacement R2 and a displacement T2 to be displaced, respectively, in accordance with the received electric signal corresponding to the outside air temperature, and transmits the electric signals corresponding to each displacement to the operation control unit 0, and the operation control unit 0 corrects the rotor rotation speed R corrected based on the reference value R0, the displacement R1, and the displacement R2. V is determined, and the rotor rotation speed R V and transmitting an electrical signal corresponding to the reference value T0, the displacement amount T1, and the displacement amount T2 to the kneading machine. V is determined, and the kneading time T V The kneader transmits an electric signal corresponding to the rotor rotation speed R V and the kneading time T V The kneading device performs kneading in accordance with an electrical signal corresponding to the above.

[0019] While not intending to be bound by theory, the mechanism by which the above-mentioned effect is exhibited is thought to be as follows. That is, in the present disclosure, when kneading a rubber composition, in addition to measuring the temperature of the rubber component immediately before adding the rubber component, the ambient temperature is also measured. For example, if the ambient temperature is high, the temperature rise during kneading of the rubber component and various additives will be rapid. For example, when mixing a rubber component containing silica and a silane coupling agent, the coupling reaction between the silica and the silane coupling agent will proceed excessively, causing a crosslinking reaction and gelation, which is an important factor in suppressing batch-to-batch variation. Furthermore, in the present disclosure, the kneading rotation speed is also adjusted in addition to the kneading time, taking into account the measured temperature information. For example, the kneading rotation speed needs to be reduced to suppress the temperature rise during kneading of the rubber component and various additives. However, care must be taken because lowering the rotor rotation speed too much reduces shear energy, resulting in insufficient mixing of the rubber component and various additives at the end of kneading. In the present disclosure, not only the temperature of the rubber component but also the ambient temperature is measured immediately before the rubber component is added, and based on the temperature information thus obtained, not only the kneading time but also the kneading rotation speed is adjusted when kneading is carried out. This combination of measurement and adjustment works surprisingly well, and as a result, it is believed that the variation between batches in the properties of the rubber composition at the end of kneading is well suppressed.

[0020] [Method of manufacturing rubber composition] The method for producing the rubber composition of the present disclosure will be described below.

[0021] <Rubber component> The rubber component is not particularly limited, and any rubber conventionally used in the rubber industry can be suitably used. Examples include diene rubbers such as isoprene rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene rubber (SIR), styrene-isoprene-butadiene rubber (SIBR), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR), and butyl rubbers such as halogenated butyl rubbers including butyl rubber (IIR), brominated butyl rubber (Br-IIR), chlorinated butyl rubber (Cl-IIR), and fluorinated butyl rubber (F-IIR). These rubber components can be used alone or in combination of two or more. Among these, from the viewpoint of obtaining a high-performance rubber composition by blending silica, it is preferable to include SBR, more preferably SBR and BR, more preferably SBR, BR, and isoprene rubber, and even more preferably SBR, BR, and isoprene rubber alone.

[0022] (styrene butadiene rubber) Styrene-butadiene rubber (SBR) is not particularly limited and includes, for example, unmodified emulsion-polymerized styrene-butadiene rubber (E-SBR) and solution-polymerized styrene-butadiene rubber (S-SBR), as well as modified SBRs such as modified emulsion-polymerized styrene-butadiene rubber (modified E-SBR) and modified solution-polymerized styrene-butadiene rubber (modified S-SBR). Modified SBRs include SBRs whose terminals and / or main chains are modified, and modified SBRs (condensates, branched structures, etc.) coupled with tin or silicon compounds. SBRs include oil-extended types in which flexibility is adjusted by adding an extender oil, and non-oil-extended types in which no extender oil is added, and either type can be used. Examples of such SBRs include those manufactured by JSR Corporation, Asahi Kasei Chemicals Corporation, Nippon Zeon Corporation, and ZS Elastomers Co., Ltd. These SBRs can be used alone or in combination of two or more. Among these, from the viewpoint of obtaining a rubber composition excellent in fuel economy and wet grip performance by blending silica, solution-polymerized styrene-butadiene rubber (S-SBR) is preferred, and modified solution-polymerized styrene-butadiene rubber (modified S-SBR) is more preferred. According to the production method including the kneading step of the present disclosure, even when silica is blended into the modified S-SBR, efficient kneading can be achieved by ensuring a sufficient kneading time in the temperature range where silanization progresses, thereby achieving the effect of improving the dispersibility of silica as silanization progresses.

[0023] The styrene content of SBR is preferably 15.0% by mass or more, more preferably 20.0% by mass or more, from the viewpoint of rubber strength and grip performance. Also, from the viewpoint of fuel economy, the styrene content is preferably 40.0% by mass or less, more preferably 30.0% by mass or less. The styrene content of SBR is 1 This is a value calculated by H-NMR measurement.

[0024] The vinyl content (amount of 1,2-bonded butadiene units) of SBR is preferably 10.0% or more, preferably 25.0% or more, and more preferably 40.0% or more, from the viewpoint of rubber strength and grip performance. Furthermore, the vinyl content is preferably 80.0% or less, preferably 75.0% or less, and more preferably 70.0% or less, from the viewpoint of fuel economy. The vinyl content of SBR is a value measured by infrared absorption spectroscopy.

[0025] The glass transition temperature (Tg) of SBR is preferably −90° C. or higher, more preferably −50° C. or higher, and even more preferably −40° C. or higher. The Tg is preferably 0° C. or lower, more preferably −10° C. or lower, and even more preferably −15° C. or lower. The Tg of SBR is a value measured in accordance with JIS K 7121 using a differential scanning calorimeter (Q200) manufactured by TA Instruments Japan, Inc., at a heating rate of 10° C. / min.

[0026] The weight-average molecular weight (Mw) of SBR is preferably 200,000 or more, more preferably 300,000 or more. Furthermore, the Mw is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less. The Mw and number-average molecular weight (Mn) of SBR, which will be described later, can be determined in terms of standard polystyrene based on measurements obtained by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMALTPORE HZ-M manufactured by Tosoh Corporation).

[0027] When SBR is contained, the content in the rubber component is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. The SBR content may be 100% by mass, but is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 60% by mass or less. By setting the SBR content within the above range, good silica dispersibility and good processability tend to be obtained. When oil-extended SBR is used as the SBR, the content of SBR itself as a solid content contained in the oil-extended SBR is defined as the SBR content in the rubber component.

[0028] (butadiene rubber) The butadiene rubber (BR) is not particularly limited, and any rubber commonly used in this field can be suitably used. For example, various BRs can be used, such as low-cis polybutadiene rubber (low-cis BR), high-cis polybutadiene rubber (high-cis BR), rare earth butadiene rubber synthesized using a rare earth catalyst (rare earth BR), butadiene rubber containing 1,2-syndiotactic polybutadiene crystals (SPB-containing BR), and modified butadiene rubber (modified BR). Examples of such BRs that can be used include those manufactured by Ube Industries, Ltd., Zeon Corporation, JSR Corporation, Lanxess AG, and Asahi Kasei Corporation. These BRs can be used alone or in combination of two or more.

[0029] High-cis BR is a butadiene rubber with a cis content (cis-1,4 bond content) of 90% or more. Of these, those with a cis-1,4 bond content of 93% or more are preferred, those with a cis-1,4 bond content of 94% or more are more preferred, and those with a cis-1,4 bond content of 95% or more are even more preferred. The inclusion of high-cis BR can improve low heat buildup, tensile strength, elongation at break, and abrasion resistance. The cis-1,4 bond content in BR is a value calculated by infrared absorption spectroscopy.

[0030] When BR is contained, the content in the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of abrasion resistance, and preferably 80% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, from the viewpoint of processability.

[0031] (Isoprene rubber) Isoprene-based rubbers that can be used include those commonly used in the rubber industry, such as isoprene rubber (IR) and natural rubber. Natural rubber includes unmodified natural rubber (NR) as well as modified natural rubbers such as epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), deproteinized natural rubber (DPNR), highly purified natural rubber, and grafted natural rubber. Of these, NR is preferred. These isoprene-based rubbers can be used alone or in combination.

[0032] The NR is not particularly limited, and for example, those commonly used in the rubber industry, such as SIR20, RSS#3, and TSR20, can be used.

[0033] When an isoprene-based rubber is contained, the content in the rubber component is preferably 5% by mass or more, and more preferably 10% by mass or more, from the viewpoint of heat generation suppression effect, etc. The content of the isoprene-based rubber is preferably 90% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less.

[0034] <Additives> The rubber composition of the present disclosure contains, in addition to the rubber component described above, additives commonly used in the production of rubber compositions, such as fillers commonly used in this field, such as silica, carbon black, aluminum hydroxide, alumina (aluminum oxide), calcium carbonate, talc, and clay, as well as silane coupling agents, oils, resins, stearic acid, zinc oxide, inorganic potassium salts, antioxidants, waxes, processing aids, vulcanizing agents, and vulcanization accelerators.

[0035] One or more fillers can be used. In the present disclosure, it is preferable to contain silica as the filler. When silica is contained as the filler, a silane coupling agent is usually also compounded and kneaded. In this case, if the coupling reaction between the silica and the silane coupling agent proceeds excessively, gelation occurs, resulting in poor sheet texture, so it is important to carefully adjust the temperature at which the rubber composition is kneaded. Furthermore, from the viewpoint of rubber strength, it is preferable to contain carbon black as a filler other than silica.

[0036] (silica) The silica is not particularly limited, and examples thereof include silica (anhydrous silicic acid) prepared by a dry method and silica (hydrated silicic acid) prepared by a wet method. Among these, silica prepared by a wet method is preferred because it has many silanol groups on the surface and many reaction sites with silane coupling agents. For example, silica manufactured and sold by Evonik Japan Co., Ltd., Solvay, Tosoh Silica Co., Ltd., Tokuyama Corporation, etc. can be used. These silicas can be used alone or in combination of two or more.

[0037] The nitrogen adsorption specific surface area (N2SA) of silica is not particularly limited, but from the viewpoint of fuel economy and wear resistance, it is preferable that the nitrogen adsorption specific surface area (N2SA) is 80m 2 / g or more is preferable, and 110m 2 / g or more is more preferable, and 140m 2 / g or more is more preferable, and 170m 2 / g or more is more preferable. From the viewpoint of dispersibility and processability of silica, the N2SA of silica is 500m 2 / g or less is preferable, and 400m 2 / g or less is more preferable, and 300m 2 / g or less is more preferable, and 200m 2 / g or less is more preferable. The N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-81.

[0038] The amount of silica per 100 parts by mass of the rubber component is not particularly limited, but is preferably at least 1 part by mass, more preferably at least 3 parts by mass, and more preferably at least 5 parts by mass. The upper limit of the amount of silica is not particularly limited, but is preferably at most 150 parts by mass, more preferably at most 120 parts by mass, more preferably at most 110 parts by mass, and even more preferably at most 100 parts by mass. When the amount of silica is within the above range, good dispersibility and good processability tend to be obtained, and the effects of the present disclosure can be more effectively exhibited.

[0039] (carbon black) The carbon black is not particularly limited, and those commonly used in the rubber industry, such as GPF, FEF, HAF, ISAF, and SAF, can be used. For example, those manufactured and sold by Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Nippon Steel Carbon Co., Ltd., Columbia Carbon Co., Ltd., etc. These carbon blacks can be used alone or in combination of two or more.

[0040] The carbon black N2SA is not particularly limited, but from the viewpoint of obtaining sufficient reinforcement and good abrasion resistance, 50m 2 / g or more is preferable, and 80m 2 / g or more is more preferable, and 110m 2 / g or more is more preferable. In addition, N2SA carbon black has excellent dispersibility and is less likely to generate heat. 2 / g or less is preferable, and 300m 2 / g or less is more preferable, and 200m 2 / g or less is more preferable. The N2SA of carbon black is a value measured in accordance with JIS K 6217-2:2001.

[0041] When carbon black is contained, the content per 100 parts by mass of the rubber component is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more. The carbon black content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less. When the carbon black content is within the above range, sufficient reinforcing properties, good dispersion in the rubber, and good processability tend to be obtained, and the effects of the present disclosure can be more effectively exhibited.

[0042] <Silane coupling agent> The silane coupling agent is not particularly limited, and any silane coupling agent that has been conventionally used in combination with silica in the rubber industry can be used. Examples of such silane coupling agents include silane coupling agents having a sulfide group such as bis(3-triethoxysilylpropyl) disulfide and bis(3-triethoxysilylpropyl) tetrasulfide; silane coupling agents having a mercapto group such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, compounds represented by the following formula (1) described below, and compounds containing a bond unit A represented by the following formula (2) and a bond unit B represented by the following formula (3) described below; 3-octanoylthio-1-propyltriethoxysilane, 3-hexanoylthio-1-propyltriethoxysilane, 3-octanoylthio-1-propyltrimethoxysilane, 3-octanoylthio-1-propyltrieth ... Examples of suitable silane coupling agents include silane coupling agents having a thioester group such as hydroxysilane; silane coupling agents having a vinyl group such as vinyltriethoxysilane and vinyltrimethoxysilane; silane coupling agents having an amino group such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltriethoxysilane; glycidoxy-based silane coupling agents such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based silane coupling agents such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based silane coupling agents such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Among these, silane coupling agents having a sulfide group are preferred. Examples of suitable silane coupling agents include those manufactured by Momentive and Evonik Japan Co., Ltd. These silane coupling agents can be used alone or in combination of two or more.

[0043] The content of the silane coupling agent relative to 100 parts by mass of silica is preferably 4.0 parts by mass or more, more preferably 5.0 parts by mass or more, more preferably 6.0 parts by mass or more, and even more preferably 7.0 parts by mass or more, because it can obtain a sufficient silica dispersion effect.In addition, the content of the silane coupling agent is preferably 20.0 parts by mass or less, more preferably 15.0 parts by mass or less, and even more preferably 12.0 parts by mass or less, because it can efficiently obtain a sufficient coupling effect and silica dispersion effect and ensure reinforcement.

[0044] (oil) The oil is not particularly limited, and any oil commonly used in the rubber industry can be suitably used. Examples include paraffinic, aromatic, and naphthenic process oils. Furthermore, for environmental reasons, process oils with a low content of polycyclic aromatic compounds (PCA) can be used. Examples of low-PCA process oils include Treated Distillate Aromatic Extract (TDAE), which is a re-extraction of aromatic process oil, aroma substitute oils that are mixtures of asphalt and naphthenic oil, mild extraction solvates (MES), and heavy naphthenic oil. Among these, aromatic process oils are preferred. Examples of oils that can be used include those manufactured and sold by H&R, ENEOS Corporation, Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., and others. These oils can be used alone or in combination.

[0045] When oil is contained, the content per 100 parts by mass of the rubber component is not particularly limited, but is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more. The oil content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. By setting the oil content within the above range, the effects of rubber plasticization and improved silica dispersion tend to be more effectively exhibited, and the effects of the present disclosure can be more effectively exhibited. The oil content includes the amount of oil used in oil extension.

[0046] (resin) The resin is not particularly limited, and resins commonly used in conventional rubber compositions for tires, such as aromatic petroleum resins, can be used. Examples of aromatic petroleum resins include phenolic resins, coumarone-indene resins, styrene resins, terpene resins, acrylic resins, rosin resins, and dicyclopentadiene resins (DCPD resins). Examples of phenolic resins include those manufactured by BASF and Taoka Chemical Co., Ltd.; examples of coumarone-indene resins include those manufactured by Nippon Steel Chemical & Material Co., Ltd. and ENEOS Corporation; and examples of styrene resins include those manufactured by Arizona Chemical Co., Ltd. Examples of terpene resins include those manufactured by Arizona Chemical Co., Ltd. and Yasuhara Chemical Co., Ltd. Examples of rosin resins include those manufactured by Harima Chemical Co., Ltd. and Arakawa Chemical Co., Ltd. These resins can be used alone or in combination of two or more.

[0047] When a resin is contained, the content per 100 parts by mass of the rubber component is preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more. The content of the resin is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less. By setting the content of the resin within the above range, the effects of the present disclosure can be more effectively exhibited.

[0048] (stearic acid) When stearic acid is contained, the content per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, from the viewpoint of increasing the vulcanization rate of the rubber and improving tire productivity, and is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, from the viewpoint of preventing a decrease in abrasion resistance.

[0049] (zinc oxide) When zinc oxide is contained, the content per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, from the viewpoint of increasing the vulcanization rate of the rubber and improving tire productivity, and is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, from the viewpoint of preventing a decrease in abrasion resistance.

[0050] (inorganic potassium salts) The inorganic potassium salt may be any of those commonly used in the tire industry, and may be used alone or in combination of two or more. Examples of the inorganic potassium salt include one or more potassium salts selected from the group consisting of potassium carbonate, potassium bicarbonate, and potassium tetraborate, and among these, potassium tetraborate is preferred.

[0051] (anti-aging agent) The antioxidant is not particularly limited, and any of those commonly used in the rubber industry can be suitably used. Examples include quinoline-based antioxidants, quinone-based antioxidants, phenol-based antioxidants, phenylenediamine-based antioxidants, and metal carbamates. Among these, phenylenediamine-based antioxidants are preferred because they can better demonstrate the effects of the present disclosure. Examples of phenylenediamine-based antioxidants include N-phenyl-N'-isopropyl-p-phenylenediamine (IPPD) and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD) is more preferred. Examples of antioxidants that can be used include those manufactured by Ouchi Shinko Chemical Industry Co., Ltd., Kawaguchi Chemical Industry Co., Ltd., and Sumitomo Chemical Co., Ltd. These antioxidants can be used alone or in combination of two or more.

[0052] When an antioxidant is contained, the content thereof per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, and even more preferably 1.0 part by mass or more. The content of the antioxidant is preferably 7.0 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 3.0 parts by mass or less. By setting the content of the antioxidant within the above range, it tends to be possible to obtain a sufficient anti-aging effect and to suppress discoloration caused by precipitation of the antioxidant on the tire surface.

[0053] (wax) The wax is not particularly limited, and any wax commonly used in the rubber industry can be suitably used, such as petroleum wax, mineral wax, and synthetic wax. Of these, petroleum wax is preferred. Examples of petroleum wax include paraffin wax and microcrystalline wax. Waxes that can be used include those manufactured by Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Paramelt Co., Ltd. These waxes can be used alone or in combination of two or more.

[0054] When wax is contained, the content per 100 parts by mass of the rubber component is preferably 0.3 parts by mass or more, more preferably 0.7 parts by mass or more, and even more preferably 0.8 parts by mass or more. The content of wax is preferably 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, and even more preferably 2.0 parts by mass or less. By setting the wax content within the above range, the effects of the present disclosure can be more effectively exhibited.

[0055] (processing aids) Examples of processing aids include fatty acid metal salts, fatty acid amides, amide esters, silica surfactants, fatty acid esters, mixtures of fatty acid metal salts and amide esters, mixtures of fatty acid metal salts and fatty acid amides, etc. Examples of processing aids that can be used include those manufactured by Struktol Co., Ltd. and Tesco Co., Ltd. These processing aids can be used alone or in combination of two or more.

[0056] When a processing aid is contained, the content thereof per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, and even more preferably 1.0 part by mass or more. The content of the processing aid is preferably 10.0 parts by mass or less, more preferably 8.0 parts by mass or less, and even more preferably 6.0 parts by mass or less. By setting the content of the processing aid within the above range, the effects of the present disclosure can be more effectively exhibited.

[0057] (vulcanizing agent) The vulcanizing agent is not particularly limited, and known vulcanizing agents can be used, such as organic peroxides, sulfur-based vulcanizing agents, resin vulcanizing agents, and metal oxides such as magnesium oxide. Of these, sulfur-based vulcanizing agents are preferred. Examples of sulfur-based vulcanizing agents that can be used include sulfur and morpholine disulfide. Of these, sulfur is preferred. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur, all of which are suitable. These vulcanizing agents can be used alone or in combination of two or more.

[0058] When a vulcanizing agent is contained, the content thereof per 100 parts by mass of the rubber component is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more. The content of the vulcanizing agent is preferably 4.0 parts by mass or less, more preferably 3.5 parts by mass or less, and even more preferably 3.0 parts by mass or less. By setting the content of the vulcanizing agent within the above range, the effects of the present disclosure can be more effectively exhibited.

[0059] (Vulcanization accelerator) The vulcanization accelerator is not particularly limited, and known vulcanization accelerators can be used, such as sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based or aldehyde-ammonia-based, imidazoline-based, or xanthate-based vulcanization accelerators. Among these, those containing sulfenamide-based and guanidine-based accelerators are preferred, and those containing only sulfenamide-based and guanidine-based accelerators are more preferred. These vulcanization accelerators can be used alone or in combination of two or more.

[0060] Examples of sulfenamide vulcanization accelerators include N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N'-dicyclohexyl-2-benzothiazolylsulfenamide (DZ), etc. Among them, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS) is preferred.

[0061] Examples of guanidine vulcanization accelerators include 1,3-diphenylguanidine (DPG), di-orthotolylguanidine, orthotolylbiguanidine, etc. Among these, 1,3-diphenylguanidine (DPG) is preferred from the viewpoint of shortening the vulcanization time.

[0062] When a vulcanization accelerator is contained, the content thereof is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, and even more preferably 1.5 parts by mass or more, per 100 parts by mass of the rubber component, and is preferably 4.0 parts by mass or less, more preferably 3.5 parts by mass or less, and even more preferably 3.0 parts by mass or less.

[0063] <Batch mixing> In the present disclosure, batch mixing refers to each mixing when mixing predetermined amounts of raw materials in predetermined formulations multiple times. The manufacturing method of the present disclosure is intended to suppress variation in properties between batches of the rubber composition obtained in the batch mixing.

[0064] In the present disclosure, the batch kneading may be any kneading method as long as the rubber component and desired additives are kneaded together, and the additives may contain vulcanization-related chemicals consisting of a vulcanizing agent and a vulcanization accelerator, or may not contain vulcanization-related chemicals.

[0065] Usually, when producing a vulcanized rubber composition such as a tire, the kneading process comprises a base kneading process in which rubber components and additives other than vulcanization-related chemicals are kneaded together, and a finish kneading process in which vulcanization-related chemicals are added to the mixture obtained in the base kneading process and kneaded further. However, the batch kneading method of the present disclosure can be applied only to the base kneading process, and can also be applied to processes including the finish kneading process in which vulcanization-related chemicals are added and kneaded using an internal kneader, open rolls, or the like.

[0066] The base kneading is usually performed for 1 to 10 minutes at a discharge temperature of 135 to 165°C, and the finish kneading is usually performed for 1 to 5 minutes at 90 to 110°C. Remilling (re-kneading) may be performed between the base kneading and the finish kneading.

[0067] <Kneader equipped with a rotor> As a kneader equipped with a rotor, a known kneader conventionally used in the rubber industry can be used, such as an internal kneader or an open roll. An internal kneader generally has a rotor installed above a kneading chamber. The rotor has a shaft at one or both ends, which is rotatably supported by bearings, and the rotor rotates when the shaft rotates. Two rotors are generally installed in a pair within the kneading chamber. Raw materials such as rubber components are introduced into the kneading chamber, and kneading is performed by rotating the rotor within the kneading chamber. Examples of such kneaders include Banbury mixers and kneaders. Among these, Banbury mixers are preferred due to their excellent workability and productivity. The rotor may be either a tangential or intermeshing type. The rotor may be a two-blade rotor, a four-blade rotor, or a six-blade rotor. The capacity of the kneading chamber of the internal kneader is not particularly limited, and for example, those with various capacities in the range of 1.7 to 619 L can be used.

[0068] <Process (1)> Step (1) is a step of measuring the temperature of the rubber component and the ambient air temperature immediately before being introduced into the kneader. Here, "immediately before" refers to the point in time when the rubber component is about to be introduced into the kneader. For example, if the rubber component is introduced into the kneader via a weighing conveyor, this refers to the point in time before the rubber component is introduced into the kneader on the weighing conveyor. However, as long as the measured temperature of the rubber component and the ambient air temperature hardly fluctuate, the point in time when the temperature is measured can be interpreted as "just before being introduced into the kneader," even if there is a slight time difference between the time of temperature measurement and the time of introduction of the rubber component. Here, "the temperature hardly fluctuates" means that the fluctuation range is within ±3%, preferably within ±2%, and more preferably within ±1%.

[0069] The means for measuring the temperature of the rubber component is not particularly limited as long as it can measure the temperature of the rubber component charged into the kneader for each batch, and any means can be used. For example, the temperature of the rubber component may be directly measured by a person using a thermometer, or a temperature sensor may be installed in a predetermined position in advance and mechanically measure the temperature of the rubber component immediately before being charged into the kneader. However, since the temperature of the rubber component needs to be a temperature that can represent the rubber component as a whole, the appropriate temperature measurement means may vary depending on the shape of the rubber component, etc. For example, when the rubber component is in a sheet-like form, the surface temperature of the rubber component can be measured to determine the temperature of the rubber component. On the other hand, when the rubber component is in a bale-like form, it is preferable to measure the internal temperature of the rubber component to determine the temperature of the rubber component. This is because, in the case of a bale-like rubber material, the surface temperature and internal temperature of the rubber component may differ, and the internal temperature of the rubber component is more suitable as a temperature that represents the rubber component.

[0070] Here, the sheet-like rubber component is, for example, 5 mm to 20 mm thick and 300 mm to 1000 mm wide, and the bale-like rubber component is, for example, a block-like component having a thickness of 100 mm to 300 mm, a width of 100 mm to 500 mm, and a length of 100 mm to 800 mm.

[0071] When the rubber component is in the form of a sheet, and the temperature of the rubber component is measured based on its surface temperature, a non-contact temperature measuring device, for example, an infrared radiation thermometer, is preferred because it does not require direct contact with the object to be measured and is suitable for high temperature measurement. On the other hand, when the rubber component is in the form of a bale, it is preferred to directly measure the internal temperature of the rubber component using a contact temperature measuring device, for example, a contact thermometer.

[0072] The means for measuring the ambient temperature is not particularly limited as long as it is a means capable of measuring the ambient temperature for each batch when the rubber component is fed into the kneader, and any means can be employed. As in the case of measuring the temperature of the rubber component, the temperature may be measured directly by a person using a thermometer, or a temperature sensor may be installed in advance at a predetermined position and the ambient temperature may be mechanically measured immediately before the rubber component is fed into the kneader. The ambient temperature refers to the temperature outside the kneader at the location where the kneader is installed.

[0073] <Process (2)> Step (2) is a step of calculating, for at least the rotor rotation speed and the kneading time, a displacement R1 and a displacement T1 that should be displaced, respectively, in accordance with the temperature of the rubber component, relative to a preset reference value R0 of the rotor rotation speed and a preset reference value T0 of the kneading time, and calculating a displacement R2 and a displacement T2 that should be displaced, respectively, in accordance with the outside air temperature.

[0074] (R0, T0) The reference value R0 for the rotation speed and the reference value T0 for the kneading time may vary depending on the type and amount of the rubber component and additives to be kneaded, the shape of the rubber component, the type of kneading machine, the kneading location, etc. The reference value R0 for the rotor rotation speed and the reference value T0 for the kneading time can be determined, for example, through a preliminary experiment. For example, preferred values ​​include a reference value R0 for the rotation speed of 30 rpm and a reference value T0 for the kneading time of 145 seconds when the rubber component is in a sheet form, and a reference value R0 for the rotation speed of 45 rpm and a reference value T0 for the kneading time of 130 seconds when the rubber component is in a bale form.

[0075] (R1, R2) The amount of change R1 in the rotation speed that should be varied depending on the temperature of the rubber component and the amount of change R2 in the rotation speed that should be varied depending on the type and amount of rubber component and additives being kneaded, the shape of the rubber component, the type of kneading machine, the kneading location, etc. The amount of change R1 and the amount of change R2 can be determined in advance, for example, through preliminary experiments. Specifically, the amounts of change R1 and R2 can each be, for example, based on a certain temperature (reference temperature), zero when the temperature of the rubber component is equal to the reference temperature, a positive value when the temperature of the rubber component is below the reference temperature, and a negative value when the temperature of the rubber component is above the reference temperature. The reference temperature may be a predetermined temperature or a temperature within a predetermined temperature range (i.e., in this case, the amount of change is zero when the temperature of the rubber component is within the predetermined range).

[0076] Furthermore, the displacement R1 (positive value) when the temperature of the rubber component is below the reference temperature may be a single predetermined displacement, or the absolute value of the displacement may increase in multiple stages as the temperature falls below the reference temperature to a greater extent. On the other hand, the displacement R1 (negative value) when the temperature of the rubber component is above the reference temperature may be a single predetermined displacement, or the absolute value of the displacement may increase in multiple stages as the temperature exceeds the reference temperature to a greater extent. The absolute values ​​of the displacement R1 (positive value) and the displacement R1 (negative value) may be the same or different from each other. The relationship between the temperature of the rubber component and the displacement R1 described above also applies to the relationship between the outside air temperature and the displacement R2.

[0077] When the temperature of the rubber component or the ambient temperature is lower than the reference value, it is preferable to increase the rotor rotation speed above the reference value R0 in order to promote the temperature increase during kneading of the rubber component and various additives. Conversely, when the temperature of the rubber component or the ambient temperature is higher than the reference value, it is preferable to decrease the rotor rotation speed below the reference value R0 in order to suppress the temperature increase during kneading of the rubber component and various additives.

[0078] Specific examples of the relationship between the temperature of the rubber component and the displacement R1 are as follows. When the temperature of the rubber component is below 20°C, R1>0 When the temperature of the rubber component is between 20°C and 35°C, R1=0 When the temperature of the rubber component is above 35°C, R1<0

[0079] As the value of R1, for example, when R1>0, the value is +2 rpm, and when R1<0, the value is -2 rpm.

[0080] A specific example of the relationship between the outside air temperature and the displacement R2 is as follows. When the outside temperature is below 20°C, R2>0 When the outside temperature is between 20℃ and 35℃, R2=0 When the outside temperature is over 35°C, R2<0

[0081] As the value of R2, for example, when R2>0, the value is +5rmp, and when R2<0, the value is -5rmp.

[0082] (T1, T2) The amount of variation T1 in the mixing time that should be varied depending on the temperature of the rubber component and the amount of variation T2 in the mixing time that should be varied depending on the type and amount of rubber component and additives being mixed, the shape of the rubber component, the type of mixer, the location of mixing, etc. The amounts of variation T1 and T2 can be determined in advance, for example, through preliminary experiments. Specifically, the amounts of variation T1 and T2 can be determined, for example, based on a certain temperature (reference temperature), with the amount of variation being zero when the temperature of the rubber component is equal to the reference temperature, a negative value when the temperature of the rubber component is below the reference temperature, and a positive value when the temperature of the rubber component is above the reference temperature. The reference temperature may be a predetermined temperature or a temperature within a predetermined temperature range (i.e., in this case, the amount of variation is zero when the temperature of the rubber component is within the predetermined range).

[0083] Furthermore, the displacement amount T1 (negative value) when the temperature of the rubber component is below the reference temperature may be a single predetermined displacement amount, or the absolute value of the displacement amount may increase in multiple stages as the temperature falls below the reference temperature to a greater extent. On the other hand, the displacement amount T1 (positive value) when the temperature of the rubber component is above the reference temperature may be a single predetermined displacement amount, or the absolute value of the displacement amount may increase in multiple stages as the temperature exceeds the reference temperature to a greater extent. The absolute values ​​of the displacement amount T1 (negative value) and the displacement amount T1 (positive value) may be the same or different from each other. The relationship between the temperature of the rubber component and the displacement amount T1 described above also applies to the relationship between the outside air temperature and the displacement amount T2.

[0084] The reason why it is preferable to make the kneading time shorter than the reference value T0 when the temperature of the rubber component or the ambient air temperature is lower than the reference value is that, since the shear energy per unit time increases when the rotor rotation speed is increased as described above, the kneading time is adjusted to prevent the shear energy from becoming too large.On the other hand, the reason why it is preferable to make the kneading time longer than the reference value T0 when the temperature of the rubber component or the ambient air temperature is higher than the reference value is that, since the shear energy per unit time decreases when the rotor rotation speed is decreased as described above, the kneading time is adjusted to compensate for the decrease in shear energy.

[0085] Specific examples of the relationship between the temperature of the rubber component and the displacement T1 include the following. When the temperature of the rubber component is below 20°C, T1<0 When the temperature of the rubber component is between 20°C and 35°C, T1=0 When the temperature of the rubber component is above 35°C, T1>0

[0086] As the value of T1, for example, when T1<0, the value is set to -6 seconds, and when T1>0, the value is set to +6 seconds.

[0087] A specific example of the relationship between the outside air temperature and the displacement T2 is as follows. When the outside temperature is below 20°C, T2<0 When the outside temperature is between 20℃ and 35℃, T2=0 When the outside temperature is above 35°C, T2>0

[0088] For example, the value of T2 may be set to −15 seconds when T2<0 and +15 seconds when T2>0.

[0089] <Process (3)> Step (3) is a step of calculating the rotor rotation speed R corrected based on the reference value R0, the displacement amount R1, and the displacement amount R2. V and determining a kneading time T corrected based on the reference value T0, the displacement amount T1, and the displacement amount T2. V This is a process of determining:

[0090] Corrected rotor speed R V can be determined by performing a calculation based on the reference value R0, the displacement amount R1, and the displacement amount R2. V can be determined by performing calculations based on the reference value T0, the displacement amount T1, and the displacement amount T2. These determinations may be performed manually or may be processed by a calculation function provided in the operation control means.

[0091] <Process (4)> Step (4) is to calculate the corrected rotor rotation speed R V and the corrected kneading time T V This is the step of carrying out kneading.

[0092] The rotor rotation speed in step (4) is the corrected rotor rotation speed R V Similarly, the kneading time in step (4) is the corrected kneading time T V The rotor speed R V and kneading time T V The kneading may be performed by a person operating the kneader, or may be performed by the kneader receiving an electric signal transmitted from the operation control means to the kneader.

[0093] <Adjusting the amount of electricity> Preferably, the step (2) further includes a step of calculating a displacement W1 of the amount of electric power that should be varied in accordance with the temperature of the rubber component from a preset reference value W0 of the amount of electric power, and calculating a displacement W2 of the amount of electric power that should be varied in accordance with the ambient air temperature. In this case, the step (3) further includes a step of calculating the amount of electric power W corrected from the reference value W0, the displacement W1, and the displacement W2. V and the step (4) includes a step of determining the corrected amount of power W V The amount of power may also be adjusted manually or by means other than manual adjustment, as in the case of the rotation speed and kneading time described above.

[0094] The relationship between the amount of electric power and the kneading rotation speed is such that the amount of electric power increases as the kneading rotation speed increases, and decreases as the kneading rotation speed decreases. Also, the relationship between the amount of electric power and the kneading time is such that the amount of electric power increases as the kneading time increases, and decreases as the kneading time decreases. By adjusting the amount of electric power, it becomes possible to suppress variations more precisely, and the adjustment range of the amount of electric power can be determined taking into account the relationship between the amount of electric power and the kneading rotation speed and the relationship between the amount of electric power and the kneading time shown above.

[0095] <Rubber composition> In this way, a rubber composition according to the present disclosure is obtained. For example, if the batch mixing is base mixing, the rubber composition is the rubber composition after base mixing, and if the batch mixing includes base mixing and finish mixing, the rubber composition is the rubber composition after finish mixing.

[0096] The rubber composition thus obtained is a rubber composition in which variations between batches in temperature, viscosity, dough state, etc. are suppressed. For example, when batch kneading is carried out as base kneading, the difference between the maximum and minimum values ​​of the discharge temperature of the rubber composition obtained in each batch kneading is, for example, preferably within 15°C, more preferably within 13°C, even more preferably within 11°C, even more preferably within 9°C, and even more preferably within 7°C. Here, the discharge temperature in base kneading is the temperature of the kneaded material when it is discharged from the kneader. In addition, the viscosity (Mooney viscosity ML) of the rubber composition obtained in each batch kneading is 1+4 The difference between the maximum and minimum values ​​of the temperature (130°C) is, for example, preferably within 15, more preferably within 11, even more preferably within 7, and still more preferably within 5. It is also preferable that no gelation is observed in the rubber composition obtained by each batch mixing.

[0097] [Tire manufacturing method] The rubber composition of the present disclosure can be used to manufacture a tire. The tire can be manufactured by a conventional method using an unvulcanized rubber composition obtained by a manufacturing method including the above-described manufacturing method, for example.

[0098] The tire manufacturing method includes the steps of extruding the unvulcanized rubber composition obtained above into the desired shape of a tire component (e.g., tread, sidewall, carcass covering rubber, clinch, chafer, bead, breaker cushion, inner liner, etc.) to obtain the tire component, laminating and molding the tire component together with other tire components in a tire building machine to obtain an unvulcanized tire, and vulcanizing the unvulcanized tire under pressure in a vulcanizer to obtain a tire. The vulcanization conditions in this case are not particularly limited, but are, for example, pressure vulcanization at 150 to 200°C for 5 to 30 minutes.

[0099] The tire of the present disclosure may be a pneumatic tire or a non-pneumatic tire, but is preferably a pneumatic tire. Furthermore, pneumatic tires can be used for various types of tires, such as passenger car tires, truck and bus tires, motorcycle tires, and high-performance tires such as racing tires, and run-flat tires.

[0100] [Kneading equipment] The kneading device of the present disclosure will be described below with reference to FIG. 1 as appropriate.

[0101] The kneading apparatus of the present disclosure is used to carry out the method for producing the rubber composition of the present disclosure, and therefore, unless otherwise inconsistent, all descriptions regarding the method for producing the rubber composition can be interpreted as descriptions regarding the kneading apparatus.

[0102] Fig. 1 shows an example of a kneading device according to the present disclosure. The kneading device shown in Fig. 1 includes a Banbury mixer 2 (kneading machine) equipped with a rotor R, a means D1 for detecting the temperature of the rubber component 3, a means D2 for detecting the ambient air temperature, a calculation means C, and an operation control means O for controlling the operation of the Banbury mixer 2 (kneading machine).

[0103] The temperature of the rubber component 3 and the outside air temperature are detected by D1 and D2, respectively, converted into electric signals, and then transmitted from D1 and D2 to a calculation means C. The calculation means C calculates, with respect to at least the rotor rotation speed and the kneading time, a displacement amount R1 and a displacement amount T1 to be displaced, respectively, in accordance with the received electric signal corresponding to the temperature of the rubber component 3, with respect to a preset reference value R0 of the rotor rotation speed and a reference value T0 of the kneading time, and also calculates a displacement amount R2 and a displacement amount T2 to be displaced, respectively, in accordance with the received electric signal corresponding to the outside air temperature, and transmits the electric signals corresponding to each displacement amount to an operation control means O. The operation control means O calculates the rotor rotation speed R corrected based on the reference value R0, the displacement amount R1, and the displacement amount R2. V is determined, and the rotor rotation speed R V and transmitting an electrical signal corresponding to the reference value T0, the displacement amount T1, and the displacement amount T2 to the kneading machine.V is determined, and the kneading time T V The Banbury mixer 2 (kneader) receives an electric signal corresponding to the rotor rotation speed R V and the kneading time T V The kneading is carried out in accordance with an electrical signal corresponding to the above.

[0104] The means D1 and D2 for detecting the temperature of the rubber component 3 and the ambient air temperature are not particularly limited, and any detecting means can be used as long as they can measure the temperature of the rubber component and the ambient air temperature for each batch when the rubber component is fed into the kneader. Among these, the means D1 for detecting the temperature of the rubber component 3 can be suitably a non-contact temperature measuring device, such as an infrared radiation thermometer, when the rubber component 3 is in a sheet form. On the other hand, when the rubber component 3 is in a bale form, a contact temperature measuring device, such as a contact thermometer, can be suitably used to measure the internal temperature of the rubber component. The calculation means C is not particularly limited, and any calculating means can be used as long as it can calculate, based on the received temperature information, at least the rotor rotation speed and the kneading time, the displacement amounts R1 and R2 from the reference value R0, and the displacement amounts T1 and T2 from the reference value T0, and transmit electrical signals corresponding to each of the displacement amounts to the operation control means O. The operation control means O calculates the corrected rotor rotation speed R based on the reference value R0, the displacement amounts R1, and the displacement amounts R2. V Determine the rotor speed R V An electrical signal corresponding to the reference value T0, the displacement amount T1, and the displacement amount T2 is transmitted to the Banbury mixer 2 (kneader), and a corrected kneading time T V Determine the kneading time T V Any operation control means can be used as long as it can transmit an electric signal corresponding to the rotor rotation speed R to the Banbury mixer 2 (kneader). V The electrical signal corresponding to the kneading time T V There are no particular limitations on the kneading machine, and any kneading machine can be used as long as it can perform kneading in accordance with an electric signal corresponding to the above. [Example]

[0105] The present disclosure will be specifically described based on examples, but the present disclosure is not limited to these examples.

[0106] <Various raw materials used in the examples and comparative examples> SBR1: SE-0212 (amine-based end-modified solution-polymerized styrene-butadiene rubber, styrene content: 25% by mass, vinyl content: 61.0%, Tg: -25°C, Mn: 2.1 x 10 5 , Mw: 3.1 × 10 5 , non-oil-extended, available from Sumitomo Chemical Co., Ltd. SBR2: Modified styrene butadiene rubber synthesized according to the following manufacturing example BR: ASAPRENE N103 (cis content: 38% by mass, Mw: 550,000, available from Asahi Kasei Corporation) NR:TSR20 Carbon black: Diablack N220 (N2SA: 115m 2 / g, available from Mitsubishi Chemical Corporation) Silica: Ultrasil VN3 (N2SA: 175m 2 / g, available from Evonik Japan Co., Ltd.) Silane coupling agent: SI998 (bis(3-triethoxysilylpropyl) disulfide, available from Nanjing Shuguang Silane Chemical Co., Ltd.) Wax 1: Ultralube 160 (available from Keim Additec Surface) Wax 2: Ozoace 0355 (available from Nippon Seiro Co., Ltd.) Processing aid: Ultraflow 440 (available from Tesco Co., Ltd.) Inorganic potassium salt: potassium tetraborate tetrahydrate (K2B4O7·4H2O, available from Yoneyama Pharmaceutical Co., Ltd.) Stearic acid: Camellia stearate beads (available from NOF Corporation)

[0107] Manufacturing Example 1 (Manufacturing of SBR2) Cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene were charged into a nitrogen-purged autoclave reactor. After adjusting the temperature of the reactor contents to 20°C, n-butyllithium was added to initiate polymerization. Polymerization was carried out under adiabatic conditions, with the maximum temperature reaching 85°C. When the polymerization conversion reached 99%, 1,3-butadiene was added, and polymerization was continued for an additional 5 minutes. 3-Diethylaminopropyltriethoxysilane was then added as a modifier, and the reaction was continued. After the polymerization reaction was completed, 2,6-di-tert-butyl-p-cresol was added. The solvent was then removed by steam stripping, and the mixture was dried on a heated roll heated to 110°C to obtain modified SBR.

[0108] 1. When the rubber component is in sheet form (Example 1, Comparative Examples 1 and 2) <Production of Rubber Composition> (Base kneading process) According to the formulation shown in Table 1, the ingredients were kneaded using a Banbury mixer (volume 240 L, two-blade rotor) and discharged to obtain a kneaded mixture.

[0109] The kneading was carried out under the conditions shown in Table 2 for Example 1, with the rotor rotation speed (R0) set to a reference value of 30 rpm and the kneading time (T0) set to a reference value of 145 seconds, and the rotation speed and kneading time were modified.

[0110] That is, in Example 1, for the reference value of the kneading rotation speed (R0) of 30 rpm and the reference value of the kneading time (T0) of 145 seconds, under the conditions shown in Table 2, the amount of displacement (R1, T1) due to the rubber component temperature and the amount of displacement (R2, T2) due to the ambient temperature were determined according to the rubber component temperature at the time of input and the ambient temperature shown in Table 4, and the kneading rotation speed and the kneading time were corrected taking this into consideration, and the rotation speed R V , and kneading time T V The temperature of the rubber component immediately before addition was measured with a non-contact infrared thermometer.

[0111] For Comparative Example 1, the kneading was carried out under the conditions shown in Table 3, with the reference value of the kneading rotation speed (R0) set to 30 rpm and the reference value of the kneading time (T0) set to 145 seconds, with only the kneading time being adjusted depending only on the rubber component temperature at the time of addition shown in Table 4 (Table 6).

[0112] In Comparative Example 2, as shown in Table 7, regardless of the temperature of the rubber component at the time of addition and the ambient temperature, the kneading rotation speed and kneading time were both kept at the standard values ​​(R0: 30 rpm, T0: 145 seconds).

[0113] <Evaluation> The evaluation methods are as follows: The results are shown in Tables 5 to 7.

[0114] (Mooney viscosity) In accordance with JIS K 6300-1, for each copolymer, in accordance with JIS K 6300 "Testing method for unvulcanized rubber", a Mooney viscosity tester was used to rotate the large rotor at a temperature of 130°C, which was preheated for 1 minute, and the Mooney viscosity ML after 4 minutes was measured. 1+4 (130°C) was measured.

[0115] (Fabric condition) The state of the sheet dough after kneading was visually confirmed. If no gelation occurred in the sheet dough, it was marked with an O, and if gelation occurred, it was marked with an X.

[0116] [Table 1]

[0117] [Table 2]

[0118] [Table 3]

[0119] [Table 4]

[0120] [Table 5]

[0121] [Table 6]

[0122] [Table 7]

[0123] (result) Regarding the discharge temperature, in Example 1 it was within the range of 142 to 148°C, whereas in Comparative Example 1 it varied from 139 to 155°C, which is comparable to the variation (136 to 157°C) of Comparative Example 2, where no correction was made. Regarding the Mooney viscosity, in Example 1 it was within the range of 79 to 83, whereas in Comparative Example 1 it varied from 76 to 94, which is comparable to the variation (79 to 96) of Comparative Example 2, where no correction was made. Regarding the state of the dough, no gelation occurred at all in Example 1, whereas gelation was observed in one batch of Comparative Example 1 and in two batches of Comparative Example 2.

[0124] 2. When the rubber component is in a veil-like form (Example 2) The same procedures as in Example 1 were carried out, except that a bale-shaped rubber component was used instead of a sheet-shaped rubber component, the reference value for the rotor rotation speed (R0) was changed from 30 rpm to 45 rpm, the reference value for the kneading time (T0) was changed from 145 seconds to 130 seconds, the rubber component temperature and the ambient air temperature at the time of addition were those shown in Table 8 below instead of Table 4, and the temperature of the rubber component immediately before addition was measured by inserting a contact thermometer into the center of the bale-shaped rubber component, and the results shown in Table 9 below were obtained.

[0125] [Table 8]

[0126] [Table 9]

[0127] (result) In Example 2, the discharge temperature was within the range of 138 to 145°C, the Mooney viscosity was within the range of 55 to 57, and no gelation occurred in the dough state.

[0128] As described above, according to the manufacturing method of the present disclosure, a rubber composition can be obtained with reduced variations in discharge temperature, Mooney viscosity, and fabric state. [Explanation of symbols]

[0129] 1. Mixing equipment 2 Banbury Mixer 3. Rubber components C calculation means D1 Means for detecting the temperature of the rubber component D2 Means for detecting outside air temperature O Operation control means R rotor

Claims

1. A method for producing a rubber composition, comprising: The rubber component and the additives are batch-kneaded in a kneader equipped with a rotor, (1) a step of measuring the temperature of the rubber component and the ambient temperature immediately before being charged into the kneader; (2) A preset reference value R of the rotor rotation speed for at least the rotor rotation speed and the kneading time. 0 and the reference value T of the kneading time 0 The displacement R that should be displaced depending on the temperature of the rubber component 1 and displacement T 1 and the displacement amount R that should be changed depending on the outside air temperature. 2 and displacement T 2 Calculating (3) The reference value R 0 , the displacement amount R 1 and the displacement amount R 2 The rotor rotation speed R is corrected based on V and determining the reference value T 0 , the amount of displacement T 1 and the displacement amount T 2 The kneading time T is corrected based on V determining the (4) The corrected rotor rotation speed R V and the corrected kneading time T V and kneading the mixture. A method for producing a rubber composition comprising: The displacement R 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is lower than 20°C, R 1 >0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, R 1 =0 When the temperature of the rubber component exceeds 35°C, R 1 <0 The manufacturing method, wherein the displacement R 2 satisfies the following relationship depending on the outside air temperature: When the outside temperature is below 20°C, R 2 >0 When the outside temperature is between 20°C and 35°C, R 2 =0 When the outside temperature is over 35°C, R 2 <0

2. A method for producing a rubber composition, comprising: The rubber component and the additives are batch-kneaded in a kneader equipped with a rotor, (1) a step of measuring the temperature of the rubber component and the ambient temperature immediately before being charged into the kneader; (2) calculating, with respect to at least the rotor rotation speed and the kneading time, a displacement R 1 and a displacement T 1 that should be displaced in accordance with the temperature of the rubber component with respect to a preset reference value R 0 of the rotor rotation speed and a preset reference value T 0 of the kneading time, and calculating a displacement R 2 and a displacement T 2 that should be displaced in accordance with the ambient air temperature; (3) determining a rotor rotation speed R V corrected based on the reference value R 0 , the displacement amount R 1 and the displacement amount R 2 , and determining a kneading time T V corrected based on the reference value T 0 , the displacement amount T 1 and the displacement amount T 2 ; and (4) A step of carrying out kneading at the corrected rotor rotation speed R V and the corrected kneading time T V . A method for producing a rubber composition comprising: The displacement amount T 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is less than 20° C., T 1 <0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, T 1 =0 When the temperature of the rubber component is higher than 35°C, T 1 >0 The manufacturing method, wherein the displacement amount T 2 satisfies the following relationship depending on the outside air temperature: When the outside temperature is below 20°C, T 2 <0 When the outside temperature is between 20°C and 35°C, T 2 =0 When the outside temperature is above 35°C, T 2 >0

3. A method for producing a rubber composition, comprising: The rubber component and the additives are batch-kneaded in a kneader equipped with a rotor, (1) a step of measuring the temperature of the rubber component and the ambient temperature immediately before being charged into the kneader; (2) calculating, with respect to at least the rotor rotation speed and the kneading time, a displacement R 1 and a displacement T 1 that should be displaced in accordance with the temperature of the rubber component with respect to a preset reference value R 0 of the rotor rotation speed and a preset reference value T 0 of the kneading time, and calculating a displacement R 2 and a displacement T 2 that should be displaced in accordance with the ambient air temperature; (3) determining a rotor rotation speed R V corrected based on the reference value R 0 , the displacement amount R 1 and the displacement amount R 2 , and determining a kneading time T V corrected based on the reference value T 0 , the displacement amount T 1 and the displacement amount T 2 ; and (4) A step of carrying out kneading at the corrected rotor rotation speed R V and the corrected kneading time T V . A method for producing a rubber composition comprising: A manufacturing method that satisfies the following conditions (a) and (b): Condition (a): The displacement R 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is lower than 20°C, R 1 >0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, R 1 =0 When the temperature of the rubber component exceeds 35°C, R 1 <0 The displacement R 2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, R 2 >0 When the outside temperature is between 20°C and 35°C, R 2 =0 When the outside temperature is over 35°C, R 2 <0 Condition (b): The displacement amount T 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is less than 20° C., T 1 <0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, T 1 =0 When the temperature of the rubber component is higher than 35°C, T 1 >0 The displacement T 2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, T 2 <0 When the outside temperature is between 20°C and 35°C, T 2 =0 When the outside temperature is above 35°C, T 2 >0

4. The step (2) further includes: setting the amount of power to a predetermined reference value W 0 From the above, the displacement amount W that should be displaced depending on the temperature of the rubber component 1 and the displacement amount W that should be displaced according to the outside air temperature 2 wherein the electric energy is an electric energy related to the kneading rotation speed and kneading time, The step (3) further includes: 0 , the displacement amount W 1 and the displacement amount W 2 The corrected amount of power W V determining The step (4) calculates the corrected amount of power W V The method according to any one of claims 1 to 3, wherein batch mixing is carried out while further taking into consideration the above.

5. The method according to any one of claims 1 to 4, wherein the additive comprises silica.

6. The manufacturing method according to any one of claims 1 to 5, wherein the additive comprises a chemical other than a vulcanization-related chemical.

7. A method for manufacturing a tire, comprising: A step of producing an unvulcanized rubber composition by a production method including the production method according to any one of claims 1 to 6; and A step of manufacturing a tire using the unvulcanized rubber composition by a conventional method. A manufacturing method comprising:

8. A kneading apparatus for batch kneading a rubber composition, The present invention comprises a kneader having a rotor R, a means D1 for detecting the temperature of a rubber component, a means D2 for detecting the ambient air temperature, a calculation means C for calculating the amount of displacement, and an operation control means O for controlling the operation of the kneader, The detection means D1 detects the temperature of the rubber component immediately before being fed into the kneader and transmits the detected temperature as an electric signal to the calculation means C, The detection means D2 detects the outside air temperature immediately before the material is fed into the kneader, and transmits the detected temperature as an electric signal to the calculation means C. The calculation means C calculates a preset reference value R of the rotor rotation speed for at least the rotor rotation speed and the kneading time. 0 and the reference value T of the kneading time 0 a displacement amount R that should be displaced in response to the received electrical signal corresponding to the temperature of the rubber component 1 and displacement T 1 and a displacement amount R that should be changed in accordance with the received electrical signal corresponding to the outside air temperature. 2 and displacement T 2 and transmits an electric signal corresponding to each displacement amount to the operation control means O, The operation control means O determines the reference value R 0 , the displacement amount R 1 and the displacement amount R 2 The rotor rotation speed R is corrected based on V is determined, and the rotor rotation speed R V and transmitting an electrical signal corresponding to the reference value T 0 , the amount of displacement T 1 and the displacement amount T 2 The kneading time T is corrected based on V is determined, and the kneading time T V and transmits an electrical signal corresponding to the The mixer receives the rotor rotation speed R V and the kneading time T V A kneading device that performs kneading in accordance with an electrical signal corresponding to A kneading device that satisfies the following condition (a) or (b): Condition (a): The displacement R 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is lower than 20°C, R 1 >0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, R 1 =0 When the temperature of the rubber component exceeds 35°C, R 1 <0 The displacement R 2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, R 2 >0 When the outside temperature is between 20°C and 35°C, R 2 =0 When the outside temperature is over 35°C, R 2 <0 Condition (b): The displacement amount T 1 satisfies the following relationship depending on the temperature of the rubber component: When the temperature of the rubber component is less than 20° C., T 1 <0 When the temperature of the rubber component is 20° C. or higher and 35° C. or lower, T 1 =0 When the temperature of the rubber component is higher than 35°C, T 1 >0 The displacement T 2 satisfies the following relationship depending on the outside air temperature. When the outside temperature is below 20°C, T 2 <0 When the outside temperature is between 20°C and 35°C, T 2 =0 When the outside temperature is above 35°C, T 2 >0

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