JP7023698B2 - Manufacturing method of rubber parts for pneumatic tires and manufacturing method of pneumatic tires - Google Patents

Description

The present invention relates to a method for manufacturing a rubber member for a pneumatic tire obtained by vulcanizing a rubber composition containing at least a rubber wet master batch, and a method for manufacturing a pneumatic tire.

Conventionally, in the rubber industry, it has been known to use a rubber wet masterbatch in order to improve the processability when producing a rubber composition containing carbon black and the dispersibility of carbon black. This is a mixture of a carbon black-containing slurry solution in which carbon black and a dispersion solvent are mixed in a predetermined ratio in advance and carbon black is dispersed in the dispersion solvent by a mechanical force, and a rubber latex solution in a liquid phase. After that, a coagulating agent such as an acid is added to collect the coagulated product and dry it. When using a rubber wet master batch, the dispersibility of carbon black is superior to that of using a rubber dry master batch obtained by mixing carbon black and rubber in a solid phase, and rubber physical properties such as workability and reinforcing properties. An excellent rubber composition can be obtained. By using such a rubber composition as a raw material, for example, it is possible to manufacture a rubber product such as a pneumatic tire having reduced rolling resistance and excellent fatigue resistance and reinforcing property.

In the technique for manufacturing a rubber wet masterbatch, there are many reports on the manufacturing process of a carbon black-containing slurry solution.

For example, Patent Document 1 below describes a method for producing a zinc oxide-containing rubber wet masterbatch in which zinc oxide and carbon black are simultaneously dispersed using a high shear mixer. Further, Patent Document 2 below describes a method for producing a rubber composition having a premixing step of wet-mixing carbon black and smectite-based powder in the form of an aqueous slurry.

Further, in Patent Document 3 below, when the addition amount of carbon black is 120 g, 100 g of silica (83% by mass of silica when the addition amount of carbon black is 100% by mass) is added, and no surfactant is added. A method for producing a rubber wet master batch including a step of preparing a slurry solution by dispersing in water using a high shear mixer in the presence is described.

Japanese Unexamined Patent Publication No. 2006-213791 Japanese Unexamined Patent Publication No. 2002-256109 Japanese Unexamined Patent Publication No. 2006-219593

However, as a result of diligent studies by the present inventor, it has been found that there is room for further improvement in the above-mentioned prior art in terms of improving the dispersibility of carbon black. Specifically, in Patent Document 1, zinc oxide is blended when producing a carbon black-containing slurry solution, but zinc oxide does not contribute to improving the dispersibility of carbon black. Similarly, the smectite-based powder in Patent Document 2 does not contribute to improving the dispersibility of carbon black. In Patent Document 3, silica is added when the carbon black-containing slurry solution is produced, but the amount of silica added is very large relative to the amount of carbon black added, and the slurry has excellent dispersibility of carbon black. It has been found that a solution and even a rubber wet master batch obtained from this as a raw material cannot be produced.

The present invention has been made in view of the above circumstances, and an object thereof is a method for manufacturing a rubber member having excellent dispersibility of carbon black, low heat generation and excellent reinforcing property, and a pneumatic tire provided with the rubber member. The purpose is to provide a manufacturing method.

The present invention is a method for manufacturing a rubber member for a pneumatic tire obtained by vulcanizing a rubber composition containing at least a rubber wet master batch, wherein the rubber wet master batch is described in the following steps (i) to (i). iii);
Step (i): In the presence of an inorganic filler, carbon black is dispersed in a dispersion solvent to produce a slurry solution. Step (ii): The slurry solution and the rubber latex solution are mixed to form a slurry-containing rubber latex solution. Step (iii): A step of manufacturing a rubber wet master batch by coagulating and drying the slurry-containing rubber latex solution (however, the moth hardness of the inorganic filler is 5 or more, and the step (i). ), When the addition amount of the carbon black is 100% by mass, the addition amount of the inorganic filler is less than 50% by mass)), which is a rubber member for a pneumatic tire. Regarding the manufacturing method of.

The method for manufacturing a rubber member for a pneumatic tire according to the present invention is characterized by a manufacturing process of a rubber wet masterbatch used as a raw material, and specifically, it is manufactured via the following (i) to (iii). .. First, in the step (i) of dispersing carbon black in a dispersion solvent to produce a slurry solution, carbon black is dispersed in the dispersion solvent in the presence of an inorganic filler having a Mohs hardness of 5 or more. The inorganic filler having a Mohs hardness of 5 or more is harder than the carbon black, and when the carbon black is dispersed in the dispersion solvent, the carbon black is dispersed while being crushed by the inorganic filler. As a result, the dispersibility of the carbon black in the slurry solution containing the inorganic filler and the carbon black is greatly enhanced, so that the rubber finally produced even through the steps (ii) and the step (iii). Improves the dispersibility of carbon black in wet master batches. As a result of the excellent dispersibility of carbon black in the rubber wet masterbatch, the rubber composition containing the same is vulcanized, and the dispersibility of carbon black is also excellent as a rubber member. As a result, the rubber member is excellent in low heat generation and reinforcing property.

However, in the present invention, when the addition amount of carbon black is 100% by mass in the step (i), the addition amount of the inorganic filler needs to be less than 50% by mass. When the amount of carbon black added is 100% by mass, the amount of the inorganic filler added is less than 50% by mass, so that the inorganic filler enters the agglomerates of carbon black in the slurry solution and the carbon black is uniformly formed. A dispersed slurry solution can be produced. On the other hand, when the amount of carbon black added is 100% by mass, if the amount of the inorganic filler added exceeds 50% by mass, the excess inorganic filler rather deteriorates the dispersibility of the carbon black, and further, the inorganic filler. It is not preferable because the dispersibility of the product itself deteriorates.

In the above manufacturing method, it is preferable that the step (i) is a step of dispersing the carbon black in the dispersion solvent using a high shear mixer. When the carbon black is dispersed in the dispersion solvent, the use of a high shear mixer further enhances the crushing effect of the carbon black by the inorganic filler, so that the rubber in the carbon black-containing slurry solution and finally produced rubber. The dispersibility of carbon black in the wet master batch is further improved. As a result, the dispersibility of carbon black in the rubber member is further improved, so that the low heat generation property and the reinforcing property of the rubber member are also further improved.

In the above manufacturing method, it is preferable that the rubber member is a tread member. Among the rubber members constituting the pneumatic tire, the tread member is particularly required to have low heat generation and reinforcing properties, but the tread member manufactured from the rubber wet master batch manufactured through the above manufacturing process is a tread member. Since the carbon black has excellent dispersibility, low heat generation and reinforcing properties are improved.

The present invention also relates to a method for manufacturing a pneumatic tire including a rubber member, wherein the rubber member is manufactured by any one of the above manufacturing methods. Since the rubber member has excellent dispersibility of carbon black, the low heat generation and the reinforcing property of the pneumatic tire provided with the rubber member are also improved.

The method for manufacturing a rubber member for a pneumatic tire according to the present invention is characterized by a manufacturing process of a rubber wet master batch used as a raw material, and the rubber wet master batch is characterized by at least carbon black, an inorganic filler, a dispersion solvent, and a dispersion solvent. It is obtained from a rubber latex solution as a raw material.

In the present invention, as the carbon black, in addition to carbon black used in the ordinary rubber industry such as SAF, ISAF, HAF, FEF, and GPF, conductive carbon black such as acetylene black and ketjen black is used. Can be done. The carbon black may be granulated carbon black or ungranulated carbon black, which is granulated in consideration of its handleability in the ordinary rubber industry. When the total amount of the rubber component in the rubber composition obtained from the rubber wet masterbatch as a raw material is 100 parts by mass, the blending amount of carbon black is preferably 10 to 80 parts by mass, preferably 20 to 60 parts by mass. Is more preferable.

As the inorganic filler, a material having a Mohs hardness of 5 or more is used. For the Mohs hardness, 10 kinds of standard minerals corresponding to integer values from 1 to 10 are used, and the target substance is sequentially scratched with the standard minerals to determine the hardness. The larger the value, the harder it is. The standard minerals are as follows. Mohs (Mohs hardness 1), gyps (Mohs hardness 2), mineral stone (Mohs hardness 3), Mohs stone (Mohs hardness 4), Mohs ash stone (Mohs hardness 5), regular long stone (Mohs hardness 6), quartz (Mohs hardness 7) , Topaz (Mohs hardness 8), Mohs (Mohs hardness 9), Diamond (Mohs hardness 10). Examples of the inorganic filler having a Mohs hardness of 5 or more include silica (Mohs hardness (7)) and alumina (Mohs hardness 9). The Mohs hardness of silica was determined based on the Mohs hardness of silicon dioxide constituting silica. When the total amount of the rubber component in the rubber composition obtained from the rubber wet masterbatch as a raw material is 100 parts by mass, the blending amount of the inorganic filler is preferably 1 to 40 parts by mass, preferably 3 to 30 parts by mass. It is more preferable to have. The amount of the inorganic filler added to the amount of carbon black added in step (i) will be described later.

As the silica, for example, wet silica and dry silica can be used. Among them, it is preferable to use wet silica containing hydrous silicic acid as a main component.

As the dispersion solvent, it is particularly preferable to use water, but for example, water containing an organic solvent may be used.

As the rubber latex solution, a natural rubber latex solution and a synthetic rubber latex solution can be used.

The natural rubber latex solution is a natural product due to the metabolic action of plants, and a natural rubber / aqueous solution in which the dispersion solvent is water is particularly preferable. As for the natural rubber latex solution, concentrated latex or fresh latex called field latex can be used without distinction. Examples of the synthetic rubber latex solution include those produced by emulsion polymerization of styrene-butadiene rubber, butadiene rubber, nitrile rubber, and chloroprene rubber.

Hereinafter, a method for manufacturing a rubber member for a pneumatic tire according to the present invention will be described. Such a manufacturing method is characterized in the manufacturing process of the rubber wet masterbatch used as a raw material, and specifically, it is manufactured via the following (i) to (iii).
Step (i): A step of producing a slurry solution by dispersing carbon black in a dispersion solvent in the presence of an inorganic filler.
Step (ii): A step of mixing the slurry solution and the rubber latex solution to produce a slurry-containing rubber latex solution.
Step (iii): A step of manufacturing a rubber wet masterbatch by coagulating and drying the slurry-containing rubber latex solution.

(1) Step (i)
In step (i), carbon black is dispersed in a dispersion solvent in the presence of an inorganic filler to produce a slurry solution containing the inorganic filler and carbon black. As the timing of adding carbon black to the dispersion solvent, the inorganic filler may be added in advance to the dispersion solvent, and if necessary, the inorganic filler may be dispersed in the dispersion solvent, and then carbon black may be added. , Carbon black and an inorganic filler may be added to the dispersion solvent at the same time. In the step (i), the concentration of carbon black in the dispersion solvent can be appropriately adjusted in consideration of workability and the like, but in consideration of the dispersibility of carbon black, it is preferably about 2 to 15% by mass.

In the step (i), the amount of the inorganic filler added to the amount of carbon black added is less than 50% by mass. In order to produce a slurry solution in which carbon black is uniformly dispersed, it is more preferable that the amount of the inorganic filler added is less than 45% by mass with respect to the amount of carbon black added. When the amount of the inorganic filler added is extremely small relative to the amount of the carbon black added, it becomes difficult for the inorganic filler to sufficiently proceed with crushing when the carbon black is dispersed in the dispersion solvent. Therefore, the amount of the inorganic filler added to the amount of carbon black added is preferably 5% by mass or more, and more preferably 10% by mass or more.

In step (i), as a method for dispersing carbon black in a dispersion solvent in the presence of an inorganic filler, general methods such as a high shear mixer, a homomixer, a ball mill, a bead mill, a high-pressure homogenizer, an ultrasonic homogenizer, and a colloid mill are used. A method of dispersing carbon black using a disperser can be mentioned. In particular, in the present invention, it is preferable to disperse the carbon black in the dispersion solvent in the presence of the inorganic filler in the step (i) using a high shear mixer.

The above-mentioned "high shear mixer" is a mixer provided with a rotor and a stator, and the rotor rotates with a precise clearance provided between a rotor capable of high-speed rotation and a fixed stator. Means a mixer with high shearing action. In order to produce such a high shearing action, it is preferable that the clearance between the rotor and the stator is 0.8 mm or less and the peripheral speed of the rotor is 5 m / s or more. As such a high shear mixer, a commercially available product can be used, and examples thereof include a "high shear mixer" manufactured by SILVERSON.

(2) Step (ii)
In the step (ii), the slurry solution and the rubber latex solution are mixed to produce a slurry-containing rubber latex solution. The method of mixing the slurry solution and the rubber latex solution in the liquid phase is not particularly limited, and the slurry solution and the rubber latex solution are mixed with a high shear mixer, a high shear mixer, a homomixer, a ball mill, a bead mill, a high-pressure homogenizer, etc. Examples thereof include a method of mixing using a general disperser such as an ultrasonic homogenizer and a colloidal mill, or a mixer in which a blade rotates in a cylindrical container. If necessary, the entire mixing system such as a disperser may be heated during mixing.

(3) Step (iii)
In the step (iii), first, the slurry-containing rubber latex solution is coagulated to produce a carbon black-containing rubber coagulated product. As a coagulation method, a method of containing a coagulant in a slurry-containing rubber latex solution can be exemplified. In this case, as the coagulant, an acid such as formic acid or sulfuric acid, which is usually used for coagulation of a rubber latex solution, or a salt such as sodium chloride can be used. Next, in the step (iii), the obtained carbon black-containing rubber coagulum is dehydrated and dried to finally produce a rubber wet masterbatch. As a method for dehydrating and drying the obtained carbon black-containing rubber solidified product, for example, a single-screw extruder is used to dehydrate and dry the carbon black-containing rubber solidified product while applying shear force to the carbon black-containing rubber solidified product while heating at 100 to 250 ° C. It is possible to dry. Before dehydration and drying, for the purpose of appropriately reducing the amount of water contained in the carbon black-containing rubber coagulum, for example, a solid-liquid separation step using a centrifugal separation or a vibration screen may be provided. Well, or for the purpose of cleaning, a cleaning step such as a water washing method may be provided. Further, in order to further dry the rubber wet masterbatch, various drying devices such as an oven, a vacuum dryer, and an air dryer can be used.

After the step (iii), a rubber composition is produced by dry-mixing various rubber compounding agents with the obtained rubber wet masterbatch. Examples of rubber compounding agents that can be used include sulfur-based vulcanizing agents, vulcanization accelerators, antiaging agents, silica, silane coupling agents, zinc oxide, methylene acceptors and methylene donors, stearic acid, and vulcanization promoting agents. Examples include auxiliaries, vulcanization retarders, organic peroxides, softeners such as waxes and oils, and compounding agents commonly used in the rubber industry such as processing auxiliaries.

The sulfur as the sulfur-based vulcanizing agent may be ordinary sulfur for rubber, and for example, powdered sulfur, precipitated sulfur, insoluble sulfur, highly dispersible sulfur and the like can be used. The sulfur content in the rubber composition according to the present invention is preferably 0.3 to 6 parts by mass with respect to 100 parts by mass of the rubber component. If the sulfur content is less than 0.3 parts by mass, the crosslink density of the vulcanized rubber is insufficient and the rubber strength and the like are lowered, and if it exceeds 6 parts by mass, both heat resistance and durability are particularly deteriorated. .. In order to ensure good rubber strength of vulcanized rubber and further improve heat resistance and durability, the sulfur content should be 1.5 to 5.5 parts by mass with respect to 100 parts by mass of the rubber component. Is more preferable, and 2.0 to 4.5 parts by mass is further preferable.

As the vulcanization accelerator, a sulfur amide-based vulcanization accelerator, a thiuram-based vulcanization accelerator, a thiazole-based vulcanization accelerator, a thiourea-based vulcanization accelerator, and a guanidine-based vulcanization agent, which are usually used for rubber vulcanization, are used. A vulcanization accelerator such as an accelerator or a dithiocarbamate-based vulcanization accelerator may be used alone or in combination as appropriate. The content of the vulcanization accelerator is more preferably 1.0 to 5.0 parts by mass, and further preferably 1.5 to 4.0 parts by mass with respect to 100 parts by mass of the rubber component.

As anti-aging agents, aromatic amine-based anti-aging agents, amine-ketone anti-aging agents, monophenol anti-aging agents, bisphenol anti-aging agents, polyphenol anti-aging agents, dithiocarbamic acid, which are usually used for rubber. Anti-aging agents such as salt-based anti-aging agents and thiourea-based anti-aging agents may be used alone or in admixture. The content of the anti-aging agent is more preferably 0.5 to 6.0 parts by mass, still more preferably 1.0 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component.

As described above, the rubber wet masterbatch obtained in the step (iii) has excellent dispersibility of carbon black. Therefore, a pneumatic tire manufactured by using a rubber composition containing such a rubber wet master batch, specifically, a tread rubber, a side rubber, a ply or belt coated rubber, or a bead filler rubber has a rubber composition according to the present invention. Pneumatic tires made of objects are provided with, for example, a rubber member having both low heat generation and reinforcing properties. The above-mentioned rubber member can be manufactured by using a rubber composition containing a rubber wet masterbatch obtained in the step (iii) and molding by a method known to those skilled in the art. In addition, a pneumatic tire can be manufactured by combining individually manufactured unvulcanized rubber members to manufacture a raw tire and appropriately performing vulcanization molding. Since the rubber member of the pneumatic tire is excellent in low heat generation and reinforcing property, the pneumatic tire is also excellent in low heat generation and reinforcing property.

Hereinafter, examples of the present invention will be described and more specifically described.

(Raw materials used)
a) Carbon black Carbon black "N134";"Seest9H" (manufactured by Tokai Carbon Co., Ltd.)
Carbon black "N234";"Seast7HM" (manufactured by Tokai Carbon Co., Ltd.)
Carbon black "N339": "Seast KH" (manufactured by Tokai Carbon Co., Ltd.)
b) Inorganic filler silica 1; "Ultrasil 7000GR" (manufactured by Evonik), Mohs hardness 7, BET specific surface area 170 m ² / g
Silica 2; "Ultrasil 9100GR" (manufactured by Evonik), Mohs hardness 7, BET specific surface area 235 m ² / g
Alumina; "AS-50", (manufactured by Showa Denko), Mohs hardness 9
c) Dispersion solvent Water d) Rubber latex solution Natural rubber latex solution (NR field latex); (Golden Hope) (DRC = 31.2% adjusted so that the rubber concentration is 25% by mass e) Coagulation Agent Gicic acid (1st grade 85%, 10% solution diluted to adjust to pH 1.2); "Made by Nakaraitesk"
f) Synthetic rubber; "BR150L", (manufactured by Ube Industries, Ltd.)
g) Zinc Oxide Zinc Oxide No. 1; (manufactured by Mitsui Mining & Smelting Co., Ltd.)
h) Stearic acid; "Lunac S-20", (manufactured by Kao Corporation)
i) Wax; "OZOACE0355", (manufactured by Nippon Seiro Co., Ltd.)
j) Anti-aging agent (A) N-Phenyl-N'-(1,3-dimethylbutyl) -p-phenylenediamine "Nocrack 6C", (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.)
(B) 2,2,4-trimethyl-1,2-dihydroquinoline polymer "Nocrack RD", (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.)
k) Silane coupling agent; "Si69", (manufactured by Evonik Industries)
l) Sulfur, (manufactured by Tsurumi Chemical Industry Co., Ltd.)
m) Vulcanization accelerator N-cyclohexyl-2-benzothiazolesulfenamide; "Sunceller CM", (manufactured by Sanshin Chemical Industry Co., Ltd.)

Examples 1-7
Simultaneously add the amounts of carbon black and inorganic filler shown in Table 1 to water as a dispersion solvent, and disperse the carbon black using a high shear mixer, Silverson's powder and liquid mixing mixer (flash blend). (Conditions of the flash blend: 3600 rpm, 30 minutes) produced a slurry solution containing carbon black and an inorganic filler (step (i)). To the obtained slurry solution, add the amount of the natural rubber latex solution shown in Table 1 in terms of solid content, and mix using a Kawata mixer (Super Mixer SM-20) (mixer conditions 1000 rpm, 30 minutes). ), A slurry-containing natural rubber latex solution was produced (step (ii)).

Formic acid as a coagulant was added to the slurry-containing natural rubber latex solution produced in step (ii) until the entire solution reached pH 4, to produce a carbon black-containing natural rubber coagulated product. A solid-liquid separation step was carried out on the obtained carbon black-containing natural rubber coagulum, and then the rubber wet masterbatch was manufactured by putting it into a screw press V-02 type manufactured by Suehiro EPM and drying it (step (step (step). iii)). The compounding ratio in Table 1 is shown by the mass part (phr) when the total amount of the rubber component (solid content) in the natural rubber latex solution is 100 parts by mass.

A rubber composition was produced by adding various rubber compounding agents shown in Table 1 to the obtained rubber wet masterbatch and dry-mixing them using a Banbury mixer. The blending ratio in Table 1 is shown by the mass part (phr) when the total amount of the rubber component (solid content) in the natural rubber latex solution is 100 parts by mass.

Example 8
At the rubber wet master batch manufacturing stage, a rubber wet master batch is manufactured with 80 parts by mass of natural rubber (solid content), various rubber compounding agents are added, and when dry mixing using a Banbury mixer, 20 mass of synthetic rubber is used. A rubber composition was produced by partially adding and dry-mixing.

Comparative Examples 1 to 4
In Comparative Examples 1, 2, and 3, instead of producing the rubber wet masterbatch, natural rubber (RSS # 3), carbon black, silica, and various rubber compounding agents shown in Table 1 were added, and dry mixing was performed. The rubber composition was produced by the above. In Comparative Example 4, instead of producing the rubber wet master batch, natural rubber (RSS # 3), synthetic rubber, carbon black, silica and various rubber compounding agents shown in Table 1 are added and dry-mixed. As a result, a rubber composition was produced.

(evaluation)
The evaluation was performed on the rubber obtained by heating and vulcanizing each rubber composition at 150 ° C. for 30 minutes using a predetermined mold.

(Low heat generation)
Using a viscoelasticity tester manufactured by Toyo Seiki Seisakusho Co., Ltd., the loss coefficient tan δ was measured under the conditions of initial strain of 10%, dynamic strain of 1%, frequency of 10 Hz, and temperature of 60 ° C. The evaluation is shown by an index evaluation with tan δ of Comparative Example 1 as 100 for Examples 1 to 5, and similarly, an index with tan δ of Comparative Examples 2, 3 and 4 as 100 for Examples 6, 7 and 8, respectively. Shown in the evaluation. The lower the value, the better the dispersibility of carbon black in the rubber member, which means that the heat generation is excellent.

(Reinforcing)
The (break strength) (MPa) and (elongation at break) (%) of the obtained vulture rubber were measured for the sample prepared using the JIS No. 3 dumbbell in accordance with JIS-K 6251, and the measured values were used. , (Breaking strength) × (Elongation at break) was calculated (tensile product). The evaluation is shown by an index evaluation with the (tension product) of Comparative Example 1 as 100 for Examples 1 to 5, and similarly, the (anti-stretching) of Comparative Examples 2, 3 and 4 are shown for Examples 6, 7 and 8, respectively. It is shown by an index evaluation with (Zhang product) as 100. The higher the value, the better the dispersibility of carbon black in the rubber member, which means that the reinforcing property is excellent.

From the results in Table 1, since the dispersibility of carbon black in the rubber wet master batches produced in Examples 1 to 8 is excellent, the dispersibility of carbon black in the finally obtained vulcanized rubber (rubber member) is also excellent. You can see that it has improved.

Claims (4)

A method for manufacturing a rubber member for a pneumatic tire obtained by vulcanizing a rubber composition containing at least a rubber wet masterbatch.
The rubber wet masterbatch is the following steps (i) to (iii);
Step (i): In the presence of an inorganic filler, carbon black is dispersed in a dispersion solvent to produce a slurry solution. Step (ii): The slurry solution and the rubber latex solution are mixed to form a slurry-containing rubber latex solution. Step (iii): A step of manufacturing a rubber wet master batch by coagulating and drying the slurry-containing rubber latex solution (however, the inorganic filler is alumina , and in the step (i), the step A method for manufacturing a rubber member for a pneumatic tire, which is manufactured via (when the addition amount of carbon black is 100% by mass, the addition amount of the inorganic filler is less than 50% by mass). The method for manufacturing a rubber member for a pneumatic tire according to claim 1, wherein the step (i) is a step of dispersing the carbon black in the dispersion solvent using a high shear mixer. The method for manufacturing a rubber member for a pneumatic tire according to claim 1 or 2, wherein the rubber member is a tread member. A method for manufacturing pneumatic tires equipped with rubber members.
A method for manufacturing a pneumatic tire, wherein the rubber member is manufactured by the manufacturing method according to any one of claims 1 to 3.