JP7315078B1 - Rubber compositions for sealants, pneumatic tires - Google Patents

Abstract

A sealant rubber composition having excellent sealing properties and flow resistance, and a pneumatic tire (sealant tire) using the same are provided. The content of butyl rubber in 100% by mass of the rubber component is 5 to 100% by mass, and compounds represented by the following formulas (i) to (iii) and their weights are added to 100 parts by mass of the rubber component. 0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of coalescence, N-cyclohexyl-2-benzothiazolylsulfenamide, sulfur-containing compounds such as zinc dibenzyldithiocarbamate, and guanidine compounds A rubber composition for a sealant containing 1 to 10 parts by mass of a selected cross-linking accelerator. TIFF0007315078000014.tif50156 [selection drawing] Fig. 4

Description

TECHNICAL FIELD The present invention relates to a rubber composition for sealant material and a pneumatic tire using the same.

2. Description of the Related Art As a pneumatic tire having a puncture prevention function (hereinafter, a pneumatic tire is also simply referred to as a tire), a sealant tire is known in which a sealant material is applied to the inner surface of the tire. A sealant tire is one in which a hole formed when punctured is automatically closed with a sealant material, and various studies have been made on the sealant material.

For conventional sealant formulations, formulations using a combination of a quinone cross-linking agent and a peroxide have been proposed (for example, Patent Documents 1 and 2).

Japanese Patent No. 6930434 Japanese Patent No. 5589182

However, as a result of studies by the present inventors, it was found that the technique of using a quinone crosslinking agent and a peroxide in combination cannot obtain a sufficient crosslinking rate, and that there is room for improvement in sealability and flow resistance.
An object of the present invention is to solve the above-mentioned problems and to provide a rubber composition for a sealant material that is excellent in sealing properties and flow resistance, and a pneumatic tire (sealant tire) using the same.

（式（４）中、Ｒ^１及びＲ^２は、同一又は異なって、アルキル基、又は水素原子を表し、Ｒ^１及びＲ^２は環を形成してもよい。）
（式（５）中、Ｒ^３～Ｒ^６は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（６）中、Ｒ^７～Ｒ^１０は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（７）中、Ｒ^１１及びＲ^１２は、同一又は異なって、アルキル基、又は水素原子を表す。） In the present invention, the content of butyl rubber in 100% by mass of the rubber component is 5 to 100% by mass,
Per 100 parts by mass of the rubber component,
0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of compounds represented by the following formulas (i) to (iii) and polymers thereof;
The present invention relates to a sealant rubber composition containing 1 to 10 parts by mass of at least one cross-linking accelerator selected from the group consisting of compounds represented by the following formulas (1) to (7).

(In formula (4), R ¹ and R ² are the same or different and represent an alkyl group or a hydrogen atom, and R ¹ and R ² may form a ring.)
(In formula (5), R ³ to R ⁶ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In Formula (6), R ⁷ to R ¹⁰ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In formula (7), R ¹¹ and R ¹² are the same or different and represent an alkyl group or a hydrogen atom.)

The rubber composition for a sealant material of the present invention has a butyl rubber content of 5 to 100% by mass in 100% by mass of the rubber component, and contains 0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of the compounds represented by the above formulas (i) to (iii) and polymers thereof, and 1 to 10 parts by mass of at least one cross-linking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7) relative to 100 parts by mass of the rubber component. Therefore, it is possible to provide a sealant rubber composition excellent in sealing properties and flow resistance, and a pneumatic tire (sealant tire) using the same.

It is explanatory drawing which shows typically an example of the coating device used with the manufacturing method of a sealant tire. 2 is an enlarged view of the vicinity of the tip of a nozzle that constitutes the coating device shown in FIG. 1. FIG. FIG. 4 is an explanatory diagram schematically showing the positional relationship of nozzles with respect to tires; FIG. 4 is an explanatory diagram schematically showing an example of a state in which a substantially string-shaped sealant material is continuously and spirally attached to the inner peripheral surface of a tire. 2 is an enlarged view of the vicinity of the tip of a nozzle that constitutes the coating device shown in FIG. 1. FIG. It is explanatory drawing which shows typically an example of the sealant material stuck on the sealant tire. It is an explanatory view showing typically an example of the manufacturing equipment used for the manufacturing method of a sealant tire. FIG. 5 is an explanatory diagram schematically showing an example of a cross section of the sealant material when the sealant material of FIG. 4 is cut along a straight line AA perpendicular to the application direction (longitudinal direction) of the sealant material. It is an explanatory view showing an example of a section of a pneumatic tire typically.

The rubber composition for a sealant material (sealant material) of the present invention has a butyl-based rubber content of 5 to 100% by mass in 100% by mass of the rubber component, 0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of the compounds represented by the above formulas (i) to (iii) and polymers thereof, and 1 to 1 part of at least one cross-linking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7). Contains 0 parts by mass. As a result, it is excellent in sealing performance and resistance to flow.

Although the above rubber composition has the above-described effects, the reason why such effects are obtained is not necessarily clear, but it is speculated as follows.
The sealant material is applied to the inner surface of the vulcanized tire. In order for the applied sealant material to retain its shape, it is necessary to appropriately crosslink the sealant material and impart good resistance to flow.
However, as described above, as a result of investigations by the present inventors, it was found that the technique of using a quinone cross-linking agent and a peroxide in combination cannot obtain a sufficient cross-linking speed, and that there is room for improvement in sealability and flow resistance.
On the other hand, in the present invention, the rubber composition contains a specific cross-linking agent and a specific cross-linking accelerator for the rubber component containing butyl rubber, so that a suitable cross-linking reaction rate can be obtained, the cross-linking reaction can be sufficiently progressed, and excellent sealing properties and flow resistance performance (shape retention performance) are obtained.

The rubber composition for a sealant material (sealant material) of the present invention is applied to a portion of the inner surface of a tire that may be punctured, such as a tread of a sealant tire, and the sealant material will be described below while explaining a preferred example of a method for producing a sealant tire.

A sealant tire can be manufactured by, for example, preparing a sealant material by mixing each component constituting the sealant material, and then applying the obtained sealant material to the inner peripheral surface of the tire by coating or the like to form a sealant layer. The sealant tire has a sealant layer inside the inner liner in the tire radial direction.

A preferred example of a method for manufacturing a sealant tire will be described below.

A sealant tire can be manufactured by, for example, preparing a sealant material by mixing each component constituting the sealant material, and then applying the obtained sealant material to the inner peripheral surface of the tire by coating or the like to form a sealant layer. The sealant tire has a sealant layer inside the inner liner in the tire radial direction.

The sealant material is not particularly limited as long as it has adhesiveness, and ordinary rubber compositions used for tire puncture sealing can be used. Butyl-based rubber is used as a rubber component that constitutes the main component of the rubber composition. As a result, there is a tendency that moderate fluidity can be obtained while securing good air permeation resistance and deterioration resistance performance. Examples of butyl-based rubber include butyl rubber (IIR) and halogenated butyl rubber (X-IIR) such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR). These may be used alone or in combination of two or more. Among them, butyl rubber is preferred.

The Mooney viscosity ML1+8 at 125° C. of the butyl-based rubber is preferably 20 or more, more preferably 40 or more, and preferably 60 or less, from the viewpoint that the fluidity of the sealant material can be more suitably secured. Within the above range, the effect tends to be obtained more favorably.

The Mooney viscosity ML1+8 at 125° C. conforms to JIS K-6300-1:2001 and is measured at a test temperature of 125° C. with an L-shaped rotor preheating for 1 minute and rotating for 8 minutes.

The proportion of the isoprene component (isoprene unit) in the butyl rubber is preferably 1.00 mol% or more, more preferably 1.20 mol% or more, still more preferably 1.30 mol% or more, preferably 3.00 mol% or less, more preferably 2.75 mol% or less, and still more preferably 2.50 mol% or less. Within the above range, there is a tendency that a desired cross-linking rate can be achieved more favorably, and effects can be obtained more favorably.

Examples of commercially available butyl-based rubbers include products of Exxon Mobil, Japan Butyl, JSR, Cenway, and the like.

The content of the butyl rubber is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 30% by mass or more, particularly preferably 60% by mass or more, most preferably 80% by mass or more, most preferably 90% by mass or more, and may be 100% by mass, based on 100% by mass of the rubber component. Within the above range, the effect tends to be obtained more favorably.
Here, when multiple types of butyl-based rubbers are blended, the above content means the total content. The same applies to other ingredients.

In addition to the above rubber component, other components such as diene rubbers such as natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR) may be used in combination. These may be used alone or in combination of two or more.

As the rubber component, for example, a rubber component containing at least one functional group having metal coordinating ability in its molecular structure can be suitably applied. Here, the functional group having metal coordinating ability is not particularly limited as long as it has metal coordinating ability, and examples thereof include functional groups containing metal coordinating atoms such as oxygen, nitrogen, and sulfur. Specific examples include a dithiocarbamic acid group, a phosphoric acid group, a carboxylic acid group, a carbamic acid group, a dithioic acid group, an aminophosphoric acid group, and a thiol group. 1 type of the said functional groups may be contained, or 2 or more types may be contained.

Coordinating metals for the functional groups include, for example, Fe, Cu, Ag, Co, Mn, Ni, Ti, V, Zn, Mo, W, Os, Mg, Ca, Sr, Ba, Al, and Si. For example, in a polymer material containing a compound having such a metal atom (M1) and containing a functional group (-COO, etc.) having metal coordinating ability, each -COOM1 is coordinated and a large number of -COOM1 are overlapped to form clusters in which metal atoms are aggregated. The amount of the metal atom (M1) compounded is preferably 0.01 to 200 parts by mass with respect to 100 parts by mass of the rubber component.

Commercially available products of the rubber component include, for example, products of Sumitomo Chemical Co., Ltd., Ube Industries, Ltd., JSR Corporation, Asahi Kasei Co., Ltd., Nippon Zeon Co., Ltd., and the like.

Preferably, the sealant material comprises a liquid polymer. As a result, moderate fluidity can be secured more favorably, and better sealability can be obtained.

The liquid polymer in the sealant material includes liquid polybutene, liquid polyisobutene, liquid polyisoprene, liquid polybutadiene, liquid polyα-olefin, liquid isobutylene, liquid ethylene α-olefin copolymer, liquid ethylene propylene copolymer, liquid ethylene butylene copolymer, and the like. Among them, liquid polybutene is preferred because it has high compatibility with butyl rubber and more suitable effects can be obtained. Examples of liquid polybutene include copolymers mainly composed of isobutene and having a molecular structure of long-chain hydrocarbon obtained by further reacting normal butene. Hydrogenated liquid polybutene can also be used. As the liquid polymer, only one type may be used, or two or more types may be used in combination.

The kinematic viscosity at 100° C. of the liquid polymer such as liquid polybutene is preferably 500 cSt or higher, more preferably 580 cSt or higher, and even more preferably 3000 cSt or higher. The kinematic viscosity at 100° C. is preferably 6000 cSt or less, more preferably 5500 cSt or less, still more preferably 5000 cSt or less. Within the above range, the effect tends to be obtained more favorably.

The kinematic viscosity of the liquid polymer such as liquid polybutene at 40° C. is preferably 15000 cSt or higher, more preferably 20000 cSt or higher, still more preferably 25000 cSt or higher, particularly preferably 50000 cSt or higher, and most preferably 100000 cSt or higher. The kinematic viscosity at 40° C. is preferably 250,000 cSt or less, more preferably 200,000 cSt or less, still more preferably 180,000 cSt or less. Within the above range, the effect tends to be obtained more favorably.

The kinematic viscosity is a value measured at 40°C or 100°C in accordance with ASTM D445 (2019).

The content of the isobutene skeleton in 100% by mass of the liquid polybutene may be 100% by mass, but is preferably 90% by mass or less, more preferably 87% by mass or less, preferably 15% by mass or more, more preferably 30% by mass or more, still more preferably 45% by mass or more, and particularly preferably 60% by mass or more. Within the above range, a more suitable crosslinking rate can be obtained, and the effect tends to be obtained more suitably.

The number average molecular weight (Mn) of the liquid polymer such as liquid polybutene is preferably 1000 or more, more preferably 1100 or more, and preferably 6000 or less, more preferably 5500 or less. Within the above range, the effect tends to be obtained more favorably.
The weight average molecular weight (Mw) of the liquid polymer such as liquid polybutene is preferably 2,000 or more, more preferably 2,500 or more, and preferably 12,000 or less, more preferably 11,000 or less. Within the above range, the effect tends to be obtained more favorably.

The number-average molecular weight (Mn) and weight-average molecular weight (Mw) are gel permeation chromatograph (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). It can be obtained by standard polystyrene conversion based on measured values.

Commercially available products of the above liquid polymer include, for example, products of ENEOS Corporation, NOF Corporation, DAELIM, KEMAT, and INEOS.

The content of the liquid polymer (preferably liquid polybutene) is preferably 60 parts by mass or more, more preferably 80 parts by mass or more, still more preferably 100 parts by mass or more, particularly preferably 150 parts by mass or more, most preferably 200 parts by mass or more, and most preferably 250 parts by mass or more, relative to 100 parts by mass of the rubber component. The content is preferably 500 parts by mass or less, more preferably 450 parts by mass or less, even more preferably 400 parts by mass or less, and particularly preferably 350 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

Among them, as the liquid polymer, it is preferable to use only one type of liquid polymer (preferably liquid polybutene) having a kinematic viscosity at 100° C. and a kinematic viscosity at 40° C. within the above-mentioned ranges, in the content described above. By using such a type and content of the liquid polymer, the effect can be obtained more preferably.

The composition contains, as a cross-linking agent (curing agent), at least one cross-linking agent selected from the group consisting of compounds represented by the following formulas (i) to (iii) (compound (p-dinitrosobenzene) represented by the following formula (i), compound represented by the following formula (ii) (o-dinitrosobenzene), compound represented by the following formula (iii) (m-dinitrosobenzene)) and polymers thereof. Thereby, it is excellent in sealing property and flow resistance performance. These may be used alone or in combination of two or more.

The polymer of the compound represented by the above formulas (i) to (iii) is not particularly limited as long as it is a polymer having structural units based on the compounds represented by the above formulas (i) to (iii). Examples thereof include copolymers of the compounds shown in i) to (iii). These may be used alone or in combination of two or more. The above polymer may have structural units other than the structural units based on the compounds represented by the above formulas (i) to (iii).
As used herein, the polymer also includes a polymer. For example, p-dinitrosobenzene polymers also include p-dinitrosobenzene polymers. Here, the p-dinitrosobenzene polymer means a polymer containing two or more molecules of p-dinitrosobenzene. The same applies to other polymolecular bodies.

The dinitrosobenzene polymer may be a copolymer or a homopolymer, preferably a homopolymer. The content of structural units based on dinitrosobenzene in 100% by mass of the structural units of the dinitrosobenzene polymer is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more, and most preferably 100% by mass.
The content of the structural units of the dinitrosobenzene polymer is a value measured by NMR.

As the cross-linking agent, p-dinitrosobenzene and p-dinitrosobenzene polymer are preferable, p-dinitrosobenzene polymer is more preferable, and p-dinitrosobenzene polymer is still more preferable.

The content of at least one cross-linking agent selected from the group consisting of the compounds represented by formulas (i) to (iii) and polymers thereof is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, relative to 100 parts by mass of the rubber component. Within the above range, a more suitable crosslinking rate can be obtained, and the effect tends to be obtained more suitably.
Here, the content of at least one cross-linking agent selected from the group consisting of the compounds represented by the above formulas (i) to (iii) and polymers thereof means the content alone when at least one cross-linking agent selected from the group consisting of the compounds represented by the above formulas (i) to (iii) and these polymers is used alone, and the total content when two or more types are used in combination. The same applies to other descriptions.

The composition may contain, as a cross-linking agent, a cross-linking agent other than at least one cross-linking agent selected from the group consisting of the compounds represented by the above formulas (i) to (iii) and polymers thereof. Particularly preferably, it is 95% by mass or more, and may be 100% by mass.

（式（４）中、Ｒ^１及びＲ^２は、同一又は異なって、アルキル基、又は水素原子を表し、Ｒ^１及びＲ^２は環を形成してもよい。）
（式（５）中、Ｒ^３～Ｒ^６は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（６）中、Ｒ^７～Ｒ^１０は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（７）中、Ｒ^１１及びＲ^１２は、同一又は異なって、アルキル基、又は水素原子を表す。） The above composition contains at least one cross-linking accelerator selected from the group consisting of compounds represented by the following formulas (1) to (7) as a cross-linking accelerator. Thereby, it is excellent in sealing property and flow resistance performance. These may be used alone or in combination of two or more.

(In formula (4), R ¹ and R ² are the same or different and represent an alkyl group or a hydrogen atom, and R ¹ and R ² may form a ring.)
(In formula (5), R ³ to R ⁶ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In Formula (6), R ⁷ to R ¹⁰ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In formula (7), R ¹¹ and R ¹² are the same or different and represent an alkyl group or a hydrogen atom.)

The alkyl groups for R ¹ to R ¹² are not particularly limited and may be linear, branched or cyclic, but linear is preferred.
The number of carbon atoms in the alkyl group is preferably 1 or more, more preferably 3 or more, preferably 18 or less, more preferably 12 or less, and still more preferably 8 or less. Within the above range, the effect tends to be obtained more favorably. Here, when R ¹ and R ² form a ring to form a cycloalkyl group, the preferred numerical range of the number of carbon atoms in the cycloalkyl group is the same as the number of carbon atoms in the alkyl group described above.

Examples of alkyl groups for R ¹ to R ¹² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, isopentyl group, n-hexyl group, cyclopentyl group and cyclohexyl group.
Examples of the cycloalkyl group in which R ¹ and R ² form a ring include cyclopentyl group, cyclohexyl group, cycloheptyl group and the like.

The number of carbon atoms in the aromatic hydrocarbon groups of R ³ to R ¹⁰ is preferably 6 or more, preferably 18 or less, more preferably 12 or less, and even more preferably 8 or less. Within the above range, the effect tends to be obtained more favorably.
Examples of aromatic hydrocarbon groups for R ³ to R ¹⁰ include phenyl group, tolyl group, xylyl group and naphthyl group. Among them, a phenyl group is preferred.

In formula (4), R ¹ and R ² are preferably an alkyl group, a hydrogen atom, a cycloalkyl group in which R ¹ and R ² form a ring, more preferably a cycloalkyl group in which R ¹ and R ² form a ring.
In formula (5), R ³ to R ⁶ are preferably aromatic hydrocarbon groups, more preferably all of R ³ to R ⁶ are aromatic hydrocarbon groups.
In formula (6), R ⁷ to R ¹⁰ are preferably aromatic hydrocarbon groups, more preferably all of R ⁷ to R ¹⁰ are aromatic hydrocarbon groups.
In formula (7), R ¹¹ and R ¹² are preferably hydrogen atoms.

Examples of the compound represented by the above formula (4) include N-cyclohexyl-2-benzothiazolylsulfenamide, tert-butyl-2-benzothiazolylsulfenamide and the like. Among them, N-cyclohexyl-2-benzothiazolylsulfenamide is preferred.

Examples of the compound represented by formula (5) include tetrabenzylthiuram disulfide and tetramethylthiuram disulfide. Among them, tetrabenzylthiuram disulfide is preferred.

Examples of the compound represented by the above formula (6) include zinc dibenzyldithiocarbamate.

Examples of the compound represented by the above formula (7) include 1,3-diphenylguanidine and the like.

As the cross-linking accelerator, the compounds represented by the above formulas (1) to (7) are preferable, the compounds represented by the above formula (1), the compounds represented by the above formula (3), the compounds represented by the above formula (4), the compounds represented by the above formula (5), and the compounds represented by the above formula (6) are more preferable, and the compounds represented by the above formula (4) and the compounds represented by the above formula (6) are more preferable.

Commercially available cross-linking accelerators include products of Sumitomo Chemical Co., Ltd., Ouchi Shinko Kagaku Kogyo Co., Ltd., Sanshin Chemical Co., Ltd., and the like.

The content of at least one crosslinking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 5 parts by mass or more, and preferably 10 parts by mass or less, relative to 100 parts by mass of the rubber component. Within the above range, a more suitable crosslinking rate can be obtained, and the effect tends to be obtained more suitably.
Here, the content of at least one cross-linking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7) is selected from the group consisting of the compounds represented by the above formulas (1) to (7). When using at least one cross-linking accelerator alone, it means a single content, and when two or more types are used in combination, it means a total content. The same applies to other descriptions.

The composition may contain, as a cross-linking accelerator, at least one cross-linking accelerator other than the cross-linking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7). Yes, and may be 100% by mass.

In the above composition, the content of the organic peroxide, which is a conventionally used crosslinking agent, is preferably 0.3 parts by mass or less, more preferably 0.2 parts by mass or less, still more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less, most preferably 0.01 parts by mass or less, and most preferably 0 parts by mass, relative to 100 parts by mass of the rubber component. This makes it more effective.

Examples of organic peroxides include acyl peroxides such as benzoyl peroxide, dibenzoyl peroxide, and p-chlorobenzoyl peroxide; peroxy esters such as 1-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxyphthalate; ketone peroxides such as methyl ethyl ketone peroxide; hydroperoxides such as t-butyl hydroperoxide, dicumyl peroxide, t-butyl cumyl peroxide and the like. One of these may be used, or two or more of them may be used.

Commercially available products of the above organic peroxide include NOF Corporation, Arkema, Kawaguchi Pharmaceutical Co., Ltd., Nourion, and the like.

In the above composition, the content of the quinonedioxime compound (quinoid compound), which is a conventionally used cross-linking aid, is preferably 0.3 parts by mass or less, more preferably 0.2 parts by mass or less, still more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less, most preferably 0.01 parts by mass or less, and most preferably 0 parts by mass, per 100 parts by mass of the rubber component. This makes it more effective.

The quinonedioxime compounds include p-benzoquinonedioxime, p-quinonedioxime, p-quinonedioxime diacetate, p-quinonedioxime dicaproate, p-quinonedioxime dilaurate, p-quinonedioxime distearate, p-quinonedioxime dicrotonate, p-quinonedioxime dinaphthenate, p-quinonedioxime succinate, p-quinonedioxime adipate, p-quinonedioxime difuroate, p-quinonedioxime dibenzoate, p-quinonedioxime di(o-chlorobenzoate), p-quinonedioxime di(p-chlorobenzoate), p-quinonedioxime di(p-vitrobenzoate), p-quinonedioxime di(m-vitrobenzoate), p-quinonedioxime di(3,5-dinitrobenzoate), Examples include p-quinonedioxime di(p-methoxybenzoate), p-quinonedioxime di(n-amyloxybenzoate), p-quinonedioxime di(m-bromobenzoate), etc. These may be one kind or two or more kinds.

Commercially available products of the quinonedioxime compound include, for example, Fuji Film Wako Pure Chemical Co., Ltd., Junsei Chemical Co., Ltd., Ouchi Shinko Kagaku Co., Ltd., LORD, and the like.

In the above composition, the sulfur content is preferably 0.3 parts by mass or less, more preferably 0.2 parts by mass or less, even more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less, most preferably 0.01 parts by mass or less, and most preferably 0 parts by mass, based on 100 parts by mass of the rubber component. This makes it more effective.
Here, the sulfur content is the amount of sulfur derived from pure sulfur components such as powdered sulfur, and does not include sulfur derived from sulfur-containing compounds such as phenol/sulfur chloride condensates.

Sulfur includes powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and the like. One of these may be used, or two or more of them may be used.

Commercially available products of sulfur include those manufactured by Tsurumi Chemical Industry Co., Ltd., Karuizawa Io Co., Ltd., Shikoku Kasei Kogyo Co., Ltd., Flexis Co., Ltd., Nippon Kandi Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., and the like.

The rubber composition includes carbon black, silica, barium sulfate, talc, mica, mM2.xSiOy.zH2O (wherein M2 is at least one metal selected from the group consisting of aluminum, calcium, magnesium, titanium and zirconium, or an oxide, hydroxide, hydrate or carbonate of the metal, m is 1 to 5, x is 0 to 10, y is 2 to 5, and z is a numerical value in the range of 0 to 10.) inorganic filler; A plasticizer such as process oil, naphthenic process oil, or paraffinic process oil may be added. These may be used alone or in combination of two or more.

Specific examples of the filler represented by mM2.xSiOy.zH2O include aluminum hydroxide (Al(OH)3), alumina (Al2O3, Al2O3.3H2O (hydrate)), clay (Al2O3.2SiO2), kaolin (Al2O3.2SiO2.2H2O), pyrophyllite (Al2O3.4SiO2.H2O), and bentonite (Al2O3.4SiO2.2H2O). , aluminum silicate (Al2SiO5, Al4(SiO2)3.5H2O, etc.), aluminum calcium silicate (Al2O3.CaO.2SiO2), calcium hydroxide (Ca(OH)2), calcium oxide (CaO), calcium silicate (Ca2SiO4), magnesium calcium silicate (CaMgSiO4), magnesium hydroxide (Mg(OH)2), magnesium oxide (MgO), talc (MgO.4SiO2.H2O), aluminum Tapulgite (5MgO.8SiO2.9H2O), aluminum magnesium oxide (MgO.Al2O3), titanium white (TiO2), titanium black (TinO2n-1), and the like. These may be used alone or in combination of two or more.

Examples of commercially available inorganic fillers include Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Co., Ltd., Lion Corporation, Shin Nikka Carbon Co., Ltd., Columbia Carbon Co., Ltd., Degussa Co., Rhodia Corporation, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., Tokuyama Co., Ltd., and the like.

Commercially available plasticizers include, for example, Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., Japan Energy Co., Ltd., Orisoi, H&R, Toyokuni Seiyu Co., Ltd., Showa Shell Sekiyu K.K., Fuji Kosan Co., Ltd., Nisshin Oillio Group Co., Ltd., Taoka Chemical Co., Ltd., and other products.

The content of the inorganic filler is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

Carbon black is preferable as the inorganic filler from the viewpoint of preventing deterioration due to ultraviolet rays, and also from the reason that it is possible to more preferably ensure appropriate reinforcing properties while ensuring good elongation at break. In this case, the content of carbon black is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

As the carbon black, one commonly used for rubber can be appropriately used. Specifically, N110, N115, N120, N121, N125, N134, N135, N219, N220, N231, N234, N293, N299, N326, N330, N335, N339, N343, N347, N351, N356, N358, N375, N539 , N550, N582, N630, N642, N650, N660, N683, N754, N762, N765, N772, N774, N787, N907, N908, N990, N991 and the like can be preferably used. These may be used alone or in combination of two or more.

As the plasticizer (oil), dioctyl phthalate (DOP) is preferable because the softening point temperature is preferably low in order to maintain the softened state at a low temperature.
In this specification, the plasticizer does not include the liquid polymer.

The content of the plasticizer is preferably 15 parts by mass or more, more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 40 parts by mass or less, more preferably 30 parts by mass or less.

The rubber composition may contain a thermoplastic resin as an adhesive.
Specific examples of thermoplastic resins include gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, glycerin of modified rosin, rosin-based resins such as pentaerythritol esters, terpene-based resins such as α-pinene-based, β-pinene-based, dipentene-based terpene resins, aromatic modified terpene resins, terpene-phenolic resins, and hydrogenated terpene resins, and polymerization or copolymerization of C5 fraction obtained by thermal decomposition of naphtha. aromatic petroleum resins obtained by polymerizing or copolymerizing the C9 fraction obtained by thermal decomposition of naphtha; copolymer petroleum resins obtained by copolymerizing the C5 fraction and the C9 fraction; hydrogenated petroleum resins, alicyclic compound petroleum resins such as dicyclopentadiene; These may be used alone or in combination of two or more. Among them, aliphatic petroleum resins are preferable because they are more suitable for obtaining effects.

Commercially available thermoplastic resins include, for example, Nippon Zeon Co., Ltd., Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical, Nichinuri Chemical Co., Ltd., Nippon Shokubai Co., Ltd., ENEOS Co., Ltd., Arakawa Chemical Co., Ltd., Taoka Chemical Co., Ltd., and the like.

The content of the thermoplastic resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less. Within the above range, the effect tends to be obtained more favorably.

In addition to the above components, the rubber composition may further contain additives generally used in the tire industry, such as silane coupling agents and various anti-aging agents. The content of these additives is preferably 0.1 to 200 parts by mass with respect to 100 parts by mass of the rubber component.

A sealant tire having a sealant layer on the inner side of the inner liner in the tire radial direction can be produced by preparing a sealant material by mixing each of the above-described materials and applying the produced sealant material to the inner peripheral surface of the tire (preferably the radially inner portion of the inner liner in the tire radial direction). FIG. 7 shows an example of manufacturing equipment used in the method of manufacturing a sealant tire.

Application of the sealant material to the inner peripheral surface of the tire may be performed at least on the inner peripheral surface of the tire corresponding to the tread portion, more preferably at least on the inner peripheral surface of the tire corresponding to the breaker. By omitting the application of the sealant material to portions that do not need to be applied, sealant tires can be manufactured with higher productivity.
Here, the inner peripheral surface of the tire corresponding to the tread portion means the inner peripheral surface of the tire located inside the tread portion in contact with the road surface in the tire radial direction, and the inner peripheral surface of the tire corresponding to the breaker means the inner peripheral surface of the tire located inside the breaker in the tire radial direction. The breaker is a member arranged inside the tread and radially outward of the carcass, and specifically, it is a member such as the breaker 16 in FIG.

Unvulcanized tires are usually vulcanized using a bladder. This bladder expands during vulcanization and comes into close contact with the inner peripheral surface (inner liner) of the tire. Therefore, a release agent is usually applied to the inner peripheral surface (inner liner) of the tire so that the bladder and the inner peripheral surface (inner liner) of the tire do not adhere to each other when vulcanization is completed.

Water-soluble paints and release rubbers are usually used as release agents. However, if the release agent is present on the inner peripheral surface of the tire, the adhesiveness between the sealant material and the inner peripheral surface of the tire may decrease. Therefore, it is preferable to remove the release agent from the inner peripheral surface of the tire in advance. In particular, it is more preferable to remove the release agent in advance at least from the portion of the inner peripheral surface of the tire where the application of the sealant material is to be started. In addition, it is more preferable to previously remove the release agent from all portions of the inner peripheral surface of the tire to which the sealant material is to be applied. As a result, the adhesion of the sealant material to the inner peripheral surface of the tire is further improved, and a sealant tire with higher sealability can be manufactured.

The method for removing the release agent from the inner peripheral surface of the tire is not particularly limited, and includes known methods such as buffing, laser treatment, high-pressure water washing, and removal with a detergent (preferably a neutral detergent).

By continuously and spirally applying the sealant material to the inner peripheral surface of the tire, it is possible to prevent deterioration of the uniformity of the tire and to manufacture a sealant tire excellent in weight balance. In addition, by continuously spirally attaching the sealant material to the inner peripheral surface of the tire, the sealant material can form a uniform sealant layer in the tire circumferential direction and the tire width direction (especially in the tire circumferential direction). Therefore, a sealant tire having excellent sealability can be manufactured stably and with high productivity. The sealant material is preferably attached so as not to overlap in the width direction, and more preferably attached without gaps. As a result, it is possible to further prevent deterioration of tire uniformity and form a more uniform sealant layer.

In addition, the raw material is sequentially supplied to a continuous kneader (especially a twin-screw kneading extruder), and the sealant material is sequentially prepared by the continuous kneader (especially a twin-screw kneading extruder). Thereby, a sealant tire can be manufactured with good productivity.

The sealant layer is preferably formed by continuously spirally applying a substantially string-shaped sealant material to the inner peripheral surface of the tire. As a result, it is possible to form on the inner peripheral surface of the tire a sealant layer composed of a substantially string-shaped sealant material that is continuously spirally arranged along the inner peripheral surface of the tire. The sealant layer may be formed by laminating sealant materials, but preferably consists of one layer of sealant material.

When the sealant material has a substantially string-like shape, a sealant layer consisting of one layer of the sealant material can be formed by applying the sealant material continuously and spirally to the inner peripheral surface of the tire. When the sealant material has a substantially string-like shape, the applied sealant material has a certain thickness, so even with a sealant layer consisting of one layer of the sealant material, deterioration of tire uniformity can be prevented, and a sealant tire having excellent weight balance and good sealability can be manufactured. Moreover, since it is sufficient to apply only one layer of the sealant material without laminating many layers, the sealant tire can be manufactured with higher productivity.

The number of times the sealant material is wound around the inner peripheral surface of the tire is preferably 20 or more, more preferably 35 or more, preferably 70 or less, more preferably 60 or less, and even more preferably 50 or less, for the reason that it is possible to prevent deterioration of the tire uniformity, achieve excellent weight balance, and manufacture a sealant tire having good sealing performance with high productivity. Here, the number of times of winding is two times means that the sealant material is applied so as to make two turns around the inner peripheral surface of the tire. In FIG. 4, the number of times of winding the sealant material is six times.

Next, a method of applying the sealant material to the inner peripheral surface of the tire will be described below.

<First embodiment>
In the first embodiment, the sealant tire includes a step (1) of measuring the distance between the inner peripheral surface of the tire and the tip of the nozzle with a non-contact displacement sensor when the adhesive sealant material is applied to the inner peripheral surface of the tire by the nozzle while rotating the tire and moving at least one of the tire and the nozzle in the width direction of the tire, and moving at least one of the tire and the nozzle in the radial direction of the tire based on the measurement result, thereby reducing the distance between the inner peripheral surface of the tire and the tip of the nozzle. It can be manufactured by performing the step (2) of adjusting the distance to a predetermined distance and the step (3) of applying the sealant material to the inner peripheral surface of the tire whose distance is adjusted.

By measuring the distance between the inner peripheral surface of the tire and the tip of the nozzle using a non-contact displacement sensor and feeding back the measurement results, it is possible to keep the distance between the inner peripheral surface of the tire and the tip of the nozzle at a constant distance. Since the sealant material is applied to the inner peripheral surface of the tire while maintaining the above-mentioned interval at a constant distance, the thickness of the sealant material can be made uniform without being affected by variations in tire shape and unevenness of joints. Furthermore, since there is no need to input coordinate values for each tire size as in the conventional system, the sealant material can be applied efficiently.

FIG. 1 is an explanatory view schematically showing an example of an applicator used in a method for manufacturing a sealant tire. Moreover, FIG. 2 is an enlarged view of the vicinity of the tip of a nozzle that constitutes the coating apparatus shown in FIG.

FIG. 1 shows a cross section of a portion of the tire 10 taken in the meridian direction (a cross section taken along a plane including the width direction and radial direction of the tire), and FIG. 2 shows a cross section of a portion of the tire 10 taken along a plane including the circumferential direction and the radial direction of the tire. 1 and 2, the X direction is the tire width direction (axial direction), the Y direction is the tire circumferential direction, and the Z direction is the tire radial direction.

The tire 10 is set in a rotation drive device (not shown) that fixes and rotates the tire and moves it in the width direction and radial direction of the tire. This rotary drive device independently enables rotation of the tire about its axis, movement of the tire in the width direction, and movement of the tire in the radial direction.

The rotary drive device also has a control mechanism (not shown) capable of controlling the amount of radial movement of the tire. The control mechanism may be capable of controlling the amount of lateral movement of the tire and/or the rotational speed of the tire.

The nozzle 30 is attached to the tip of an extruder (not shown) and can be inserted inside the tire 10 . Then, the adhesive sealant material 20 extruded from the extruder is discharged from the tip 31 of the nozzle 30 .

The non-contact displacement sensor 40 is attached to the nozzle 30 and measures the distance d between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 .
Thus, the distance d measured by the non-contact displacement sensor is the radial distance between the inner peripheral surface of the tire and the tip of the nozzle.

In the method of manufacturing a sealant tire according to the present embodiment, first, the tire 10 molded in the vulcanization process is set in the rotary drive device, and the nozzle 30 is inserted inside the tire 10 . Then, as shown in FIGS. 1 and 2, the sealant material 20 is continuously applied to the inner peripheral surface 11 of the tire 10 by discharging the sealant material 20 from the nozzle 30 while rotating the tire 10 and moving the tire 10 in the width direction. The movement of the tire 10 in the width direction is performed along the previously input profile shape of the inner peripheral surface 11 of the tire 10 .

As will be described later, the sealant material 20 preferably has a substantially string-like shape. More specifically, when the sealant material is applied to the inner peripheral surface of the tire, it is preferable that the sealant material retains a substantially string-like shape.

In this specification, the term "substantially string-like shape" means a shape whose length is longer than its width and which has a certain amount of width and thickness. FIG. 4 schematically shows an example of a state in which a substantially string-shaped sealant material is continuously and spirally attached to the inner peripheral surface of a tire. Further, FIG. 8 schematically shows an example of a cross section of the sealant material when the sealant material of FIG. 4 is cut along a straight line AA perpendicular to the application direction (longitudinal direction) of the sealant material. Thus, the substantially string-shaped sealant material has a certain width (length indicated by W in FIG. 8) and a certain thickness (length indicated by D in FIG. 8). Here, the width of the sealant material means the width of the sealant material after application, and the thickness of the sealant material means the thickness of the sealant material after application, more specifically, the thickness of the sealant layer.

Specifically, the substantially string-shaped sealant material is a sealant material that satisfies a preferable numerical range of the thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer, the length indicated by D in FIG. 8) and the preferable numerical range of the width of the sealant material (the width of the sealant material after application, the length indicated by W in FIG. 4, and the length indicated by _W0 in FIG. 6). The sealant material satisfies the preferred numerical range of the width ratio (thickness of the sealant material/width of the sealant material). It is also a sealant material that satisfies the preferable numerical range of the cross-sectional area of the sealant material, which will be described later.

In the method for manufacturing a sealant tire according to the present embodiment, the sealant material is applied to the inner peripheral surface of the tire by the following steps (1) to (3).

<Step (1)>
As shown in FIG. 2, the non-contact displacement sensor 40 measures the distance d between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 before the sealant material 20 is applied. The distance d is measured each time the sealant material 20 is applied to the inner peripheral surface 11 of each tire 10, from the start of application of the sealant material 20 to the end of application.

<Step (2)>
The measurement data of the distance d are transferred to the control mechanism of the rotary drive. Based on the measurement data, the control mechanism adjusts the amount of radial movement of the tire so that the distance between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 is a predetermined distance.

<Step (3)>
Since the sealant material 20 is continuously discharged from the tip 31 of the nozzle 30, the sealant material 20 is applied to the inner peripheral surface 11 of the tire 10 where the interval is adjusted. Through the steps (1) to (3) described above, the sealant material 20 having a uniform thickness can be applied to the inner peripheral surface 11 of the tire 10 .

FIG. 3 is an explanatory diagram schematically showing the positional relationship of the nozzles with respect to the tire.
As shown in FIG. 3, while the nozzle 30 moves to the positions indicated by (a) to (d) with respect to the tire 10, the gap between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 is a predetermined distance _d0 .

The distance _d0 after adjustment is preferably 0.3 mm or more, and more preferably 1.0 mm or more, because the effect can be obtained more preferably. Further, the distance _d0 after adjustment is preferably 3.0 mm or less, more preferably 2.0 mm or less.
Here, the distance _d0 after adjustment is the distance in the radial direction of the tire between the inner peripheral surface of the tire and the tip of the nozzle after adjustment in step (2).

In addition, since the effect can be obtained more preferably, the distance _d0 after adjustment is preferably 30% or less, more preferably 20% or less, of the thickness of the sealant material after application, and the thickness of the sealant material after application.

The thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer, and the length indicated by D in FIG. 8) is not particularly limited because the effect can be obtained more preferably. 5.0 mm or less. The thickness of the sealant material can be adjusted by adjusting the rotational speed of the tire, the moving speed of the tire in the width direction, the distance between the tip of the nozzle and the inner peripheral surface of the tire, and the like.

The thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer) is preferably substantially constant. As a result, deterioration of tire uniformity can be further prevented, and a sealant tire having a more excellent weight balance can be manufactured.
Here, in this specification, the substantially constant thickness means that the variation in thickness falls within 90 to 110% (preferably 95 to 105%, more preferably 98 to 102%, and still more preferably 99 to 101%).

It is preferable to use a substantially string-shaped sealant material for the reason that the nozzle is less clogged and the operation stability is excellent, and because the effect is more preferably obtained, and the substantially string-shaped sealant material is more preferably applied in a spiral shape to the inner peripheral surface of the tire. However, a sealant material that does not have a substantially string-like shape may be used and the sealant material may be applied by spraying it on the inner peripheral surface of the tire.

When using a substantially string-shaped sealant material, the width of the sealant material (the width of the sealant material after application, the length indicated by W in FIG. 4) is not particularly limited. 0 mm or less, most preferably 6.0 mm or less, and most preferably 5.0 mm or less.

The ratio of the thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer, the length indicated by D in FIG. 8) and the width of the sealant material (the width of the sealant material after application, the length indicated by W in FIG. 4) (thickness of sealant material/width of sealant material) is preferably 0.6 or more, more preferably 0.7 or more, still more preferably 0.8 or more, particularly preferably 0.9 or more, and more preferably 1.4 or less, and more preferably 1.4 or less. It is 1.3 or less, more preferably 1.2 or less, and particularly preferably 1.1 or less. The closer the ratio is to 1.0, the more ideal the shape of the sealant material is, the string-like shape, and the more productively the sealant tire with high sealability can be manufactured.

The cross-sectional area of the sealant material (the cross-sectional area of the sealant material after application, in FIG. 8, the area calculated by D×W) is preferably 0.8 mm ² or more, more preferably 1.95 mm ² or more, still more preferably 3.0 mm ² or more, particularly preferably 3.75 mm ² or more, preferably 180 mm 2 or less, more preferably 104 mm 2 or less, still more preferably 45 mm ² or less, and particularly preferably 45 mm ^{2 or less, because the effect can be obtained more preferably. 35 mm 2 or less} , most preferably 25 mm ^{2 or} less.

The width of the area where the sealant material is attached (hereinafter also referred to as the width of the attached area or the width of the sealant layer, the length represented by 6×W in FIG. 4 and the length represented by W ₁ + 6×W ₀ in FIG. 6) is not particularly limited, but is preferably 80% or more, more preferably 90% or more, even more preferably 100% or more, more preferably 120% or less, and 110% or less, because the effect is more preferably obtained. more preferred.

The width of the sealant layer is preferably 85 to 115% of the tire breaker width (the length of the breaker in the tire width direction) for the reason that the effect can be obtained more favorably.
In this specification, when a tire is provided with a plurality of breakers, the length of the breaker in the tire width direction means the length in the tire width direction of the breaker having the longest length in the tire width direction among the plurality of breakers.

In this specification, the tread contact width is defined as follows. First, the outermost contact point in the tire axial direction when a normal load is applied to a non-loaded tire mounted on a normal rim and filled with a normal internal pressure and grounded on a flat surface with a camber angle of 0 degrees is defined as a "grounding edge" Te. A tread contact width TW is defined as a distance in the tire axial direction between the contact points Te and Te. Unless otherwise specified, the dimensions of each portion of the tire are values measured in this normal state.

The above-mentioned "regular rim" is a rim defined for each tire by each standard in the standard system including the standard on which the tire is based. In addition, the above-mentioned "regular internal pressure" is the air pressure determined for each tire in the standard system including the standard on which the tire is based. For JATMA, it is the "maximum air pressure"; is 180 kPa.

In addition, the above-mentioned "regular load" is the load defined for each tire in the standard system including the standard on which the tire is based. For JATMA, it is the "maximum load capacity". A load corresponding to 88% of

The rotation speed of the tire when applying the sealant material is not particularly limited, but is preferably 5 m/min or more, more preferably 10 m/min or more, and preferably 30 m/min or less, more preferably 20 m/min or less, because the effect is more preferably obtained.

By using a non-contact displacement sensor, it is possible to reduce the risk of failure due to the sealant material adhering to the sensor. The non-contact displacement sensor to be used is not particularly limited as long as it can measure the distance between the inner peripheral surface of the tire and the tip of the nozzle. Examples thereof include laser sensors, optical sensors, and capacitance sensors. These sensors may be used alone or in combination of two or more. Among them, from the viewpoint of measuring rubber, a laser sensor and an optical sensor are preferable, and a laser sensor is more preferable. When a laser sensor is used, the inner peripheral surface of the tire is irradiated with a laser, the distance between the inner peripheral surface of the tire and the tip of the laser sensor is measured from the reflection of the laser, and the distance between the tip of the laser sensor and the tip of the nozzle is subtracted from that value, whereby the distance between the inner peripheral surface of the tire and the tip of the nozzle can be obtained.

The position of the non-contact displacement sensor is not particularly limited as long as the distance between the inner peripheral surface of the tire before applying the sealant material and the tip of the nozzle can be measured, but it is preferably attached to the nozzle, and it is more preferable to install it at a position where the sealant material does not adhere.

In addition, the number, size, etc. of the non-contact displacement sensors are not particularly limited.

Since the non-contact displacement sensor is vulnerable to heat, it is preferable to perform protection using a heat insulating material or the like and/or cooling using air or the like in order to prevent the thermal effect of the high-temperature sealant material discharged from the nozzle. Thereby, the durability of the sensor can be improved.

In the description of the first embodiment, an example in which the tire moves without the nozzle moving has been described as movement in the width direction and radial direction of the tire. However, the nozzle may move without the tire moving, or both the tire and the nozzle may move.

Preferably, the rotary drive device also has means for widening the bead portion of the tire. When applying the sealant material to the tire, the sealant material can be easily applied to the tire by widening the width of the bead portion of the tire. In particular, when the nozzle is introduced into the vicinity of the inner peripheral surface of the tire after the tire is set on the rotary drive device, the nozzle can be introduced simply by moving the nozzle in parallel, thereby facilitating control and improving productivity.

The means for widening the width of the bead portion of the tire is not particularly limited as long as it is possible to widen the width of the bead portion of the tire, but examples include a mechanism that uses two sets of devices having a plurality of (preferably two) rolls that do not change their positions, and each moves in the tire width direction. The device can be inserted into the tire from both sides of the tire opening to widen the bead portion of the tire.

In the above-described manufacturing method, the sealant material mixed in a twin-screw kneading extruder or the like and the progress of the crosslinking reaction in the extruder is suppressed is applied to the inner peripheral surface of the tire as it is, so that the crosslinking reaction starts from the time of application. Therefore, it is not necessary to further crosslink the sealant tire to which the sealant material is applied, and good productivity can be obtained.

If necessary, a cross-linking step of further cross-linking the sealant tire to which the sealant material has been applied may be performed.
Preferably, the sealant tire is heated in the cross-linking step. As a result, the speed of crosslinking of the sealant material can be improved, the crosslinking reaction can proceed more favorably, and sealant tires can be manufactured with higher productivity. A heating method is not particularly limited, and a known method can be employed, but a method using an oven is preferable. For the cross-linking step, for example, the sealant tire may be placed in an oven at 70° C. to 190° C. (preferably 150° C. to 190° C.) for 2 to 15 minutes.
In addition, it is preferable to rotate the tire in the tire circumferential direction when crosslinking because it is possible to perform the crosslinking reaction without deteriorating the uniformity by preventing the fluidity even if the sealant material is easy to flow immediately after application. The rotation speed is preferably 300-1000 rpm. Specifically, for example, an oven with a rotating mechanism may be used as the oven.

Further, even if the cross-linking step is not separately performed, it is preferable to rotate the tire in the tire circumferential direction until the cross-linking reaction of the sealant material is completed. As a result, the cross-linking reaction can be performed without deteriorating the uniformity of the sealant material, which is easily flowable immediately after application, by preventing the flow. The rotation speed is the same as for the cross-linking step.

In order to improve the speed of cross-linking of the sealant material, it is preferable to preheat the tire before applying the sealant material. Thereby, a sealant tire can be manufactured with higher productivity. The tire preheating temperature is preferably 40° C. or higher, more preferably 50° C. or higher, and preferably 100° C. or lower, more preferably 70° C. or lower. By setting the preheating temperature of the tire within the above range, the cross-linking reaction starts favorably from the time of coating, the cross-linking reaction proceeds more favorably, and a sealant tire with high sealability can be produced. Further, by setting the preheating temperature of the tire within the above range, it is possible to manufacture the sealant tire with high productivity because the cross-linking step is not required.

A continuous kneader (particularly a twin-screw kneading extruder) generally operates continuously. On the other hand, when manufacturing a sealant tire, it is necessary to replace the tire after the application to one tire is completed. In this case, the following methods (1) and (2) may be adopted in order to manufacture sealant tires of higher quality while suppressing a decrease in productivity. The method (1) has the demerit of lowering the quality, and the method (2) has the demerit of increased cost.
(1) The supply of the sealant material to the inner peripheral surface of the tire is controlled by simultaneously operating and stopping the continuous kneader and all the supply devices. That is, when the application to one tire is completed, the continuous kneader and all the supply devices are stopped at the same time, the tire is replaced (preferably within 1 minute), the continuous kneader and all the supply devices are operated simultaneously, and the application to the tire is restarted. By replacing the tire quickly (preferably within 1 minute), deterioration in quality can be suppressed.
(2) The supply of the sealant material to the inner peripheral surface of the tire is controlled by switching the flow path while the continuous kneader and all supply devices are in operation. That is, the continuous kneader is provided with a separate flow path from the nozzle that feeds directly to the inner peripheral surface of the tire. In this method, a sealant tire can be manufactured while the continuous kneader and all supply devices are in operation, so that a higher quality sealant tire can be manufactured.

Carcass cords used for the carcass of the sealant tire are not particularly limited, and examples thereof include fiber cords and steel cords. Among them, steel cords are preferable. Among others, steel cords made of hard steel wire specified in JIS G3506 are desirable. In the sealant tire, by using a high-strength steel cord as the carcass cord instead of the generally used fiber cord, the side cut resistance performance (resistance to cuts in the tire side portion caused by riding on a curb, etc.) can be greatly improved, and the puncture resistance of the entire tire including the side portion can be further improved.

The structure of the steel cord is not particularly limited, and examples thereof include a 1×n single-stranded steel cord, a k+m layer-twisted steel cord, a 1×n bundle-twisted steel cord, and an m×n double-twisted steel cord. Here, the single-twisted steel cord having a 1×n configuration is a single-layer stranded steel cord obtained by twisting n filaments together. A k+m layer-twisted steel cord is a steel cord having a two-layer structure with different twisting directions and twisting pitches, with k filaments in the inner layer and m filaments in the outer layer. A stranded steel cord having a 1×n configuration is a stranded steel cord obtained by bundling and twisting n filaments. The double-twisted steel cord having an m×n configuration is a double-twisted steel cord obtained by twisting m strands obtained by twisting n filaments together. n is an integer of 1-27, k is an integer of 1-10, and m is an integer of 1-3.

The twist pitch of the steel cord is preferably 13 mm or less, more preferably 11 mm or less, and is preferably 5 mm or more, more preferably 7 mm or more.

The steel cord preferably includes at least one helically shaped shaped filament. Such typed filaments can improve rubber permeability by providing a relatively large gap in the steel cord, maintain elongation under low load, and prevent the occurrence of molding defects during vulcanization molding.

The surface of the steel cord is preferably plated with brass (brass), Zn, or the like in order to improve initial adhesion to the rubber composition.

The steel cord preferably has an elongation of 0.5 to 1.5% under a load of 50N. The elongation under a load of 50 N is more preferably 0.7% or more and more preferably 1.3% or less.

The steel cord ends are preferably 20 to 50 (cords/5 cm).

<Second embodiment>
With only the method of the first embodiment, when the sealant material has a substantially string-like shape, it may be difficult to apply the sealant material to the inner peripheral surface of the tire. In the second embodiment, in the above-described method for manufacturing a sealant tire, after setting the distance _d1 between the inner peripheral surface of the tire and the tip of the nozzle and applying the sealant material, the distance is set to a distance _d2 larger than the distance _d1 , and the sealant material is applied. As a result, the width of the sealant material corresponding to the application start portion can be widened by narrowing the distance between the inner peripheral surface of the tire and the tip of the nozzle at the start of application, and at least on the inner peripheral surface of the tire corresponding to the tread portion, an adhesive and substantially string-shaped sealant material is continuously applied in a spiral shape, and at least one of the ends of the sealant material in the longitudinal direction is a wide portion wider than the adjacent portion in the longitudinal direction. It can be manufactured easily. In the sealant tire, by widening the width of the sealant material corresponding to the attachment start portion, the adhesive strength of the portion can be improved and the peeling of the sealant material at the portion can be prevented.
In addition, in the description of the second embodiment, mainly only points different from the first embodiment will be described, and descriptions of the contents overlapping with the first embodiment will be omitted.

FIG. 5 is an enlarged view of the vicinity of the tip of the nozzle that constitutes the coating device shown in FIG.

FIG. 5 shows a cross section of a portion of the tire 10 taken along a plane including the circumferential direction and radial direction of the tire. In FIG. 5, the X direction is the tire width direction (axial direction), the Y direction is the tire circumferential direction, and the Z direction is the tire radial direction.

In the second embodiment, first, the tire 10 molded in the vulcanization process is set in the rotary drive device, and the nozzle 30 is inserted inside the tire 10 . Then, as shown in FIGS. 1 and 5, the sealant material 20 is continuously applied to the inner peripheral surface 11 of the tire 10 by discharging the sealant material 20 from the nozzle 30 while rotating the tire 10 and moving the tire 10 in the width direction. The movement of the tire 10 in the width direction is performed, for example, along the previously input profile shape of the inner peripheral surface 11 of the tire 10 .

Since the sealant material 20 has adhesiveness and has a substantially string-like shape, it is continuously and spirally affixed to the inner peripheral surface 11 of the tire 10 corresponding to the tread portion.

At this time, as shown in FIG. 5(a), the sealant material 20 is affixed with the distance _d1 between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 for a predetermined time after the affixing start. After a predetermined period of time has passed, the tire 10 is moved in the radial direction to change the distance to a distance d2 larger than the distance _d1 , and the sealant material ₂₀ is adhered, as shown in FIG. 5(b).

The distance may be returned from the distance _d2 to the distance _d1 before finishing the application of the sealant material, but from the viewpoint of manufacturing efficiency and weight balance of the tire, the distance _d2 is preferable until the application of the sealant material is finished.

In addition, it is preferable to keep the value of the _{distance d1 constant} for a predetermined period _of time from the start of attachment, and _keep the value of the distance _d2 constant after the predetermined period of time has elapsed.

Although the value of the distance _d1 is not particularly limited, it is preferably 0.3 mm or more, more preferably 0.5 mm or more because the effect is more preferably obtained, and the value of the distance _d1 is preferably 2 mm or less, more preferably 1 mm or less.

Although the value of the distance _d2 is not particularly limited, it is preferably 0.3 mm or more, more preferably 1 mm or more, and preferably 3 mm or less, more preferably 2 mm or less, because the effect can be obtained more preferably. The distance _d2 is preferably the same as the adjusted spacing _d0 described above.

In this specification, the distances d ₁ and d ₂ between the inner peripheral surface of the tire and the tip of the nozzle are the distances between the inner peripheral surface of the tire and the tip of the nozzle in the radial direction of the tire.

The rotation speed of the tire when applying the sealant material is not particularly limited, but is preferably 5 m/min or more, more preferably 10 m/min or more, and preferably 30 m/min or less, more preferably 20 m/min or less, because the effect is more preferably obtained.

Through the steps described above, the sealant tire of the second embodiment can be manufactured.
FIG. 6 is an explanatory diagram schematically showing an example of the sealant material attached to the sealant tire of the second embodiment.

The substantially string-shaped sealant material 20 is wound in the circumferential direction of the tire and is continuously attached in a spiral shape. One end of the sealant material 20 in the length direction forms a wide portion 21 that is wider than the portion adjacent to it in the length direction. This wide portion 21 corresponds to a portion where the sealant starts to be applied.

The width of the wide portion of the sealant material (the width of the wide portion of the sealant material after application, the length indicated by W1 in FIG. 6) is not particularly limited, but is preferably 103% or more, more preferably 110% or more, and even more preferably 120% or more of the width of the portion other than the wide portion (the length indicated by _{W0 in FIG. 6 )} because the effect is more preferably obtained. The width of the wide portion of the sealant material is preferably 210% or less, more preferably 180% or less, and even more preferably 160% or less of the width of the portion other than the wide portion.

The width of the wide portion of the sealant material is preferably substantially constant in the length direction, but there may be portions where the width is not substantially constant. For example, the wide portion may have the widest width at the attachment start portion, and the width may become narrower along the length direction. Here, in this specification, the width is substantially constant means that the variation in width falls within 90 to 110% (preferably 97 to 103%, more preferably 98 to 102%, and still more preferably 99 to 101%).

The length of the wide portion of the sealant material (the length of the wide portion of the sealant material after application, the length indicated by _L1 in FIG. 6) is not particularly limited, but is preferably less than 650 mm, more preferably less than 500 mm, even more preferably less than 350 mm, and particularly preferably less than 200 mm because the effect is more suitably obtained. The length of the wide portion of the sealant material is preferably as short as possible, but considering the control of the distance between the inner peripheral surface of the tire and the tip of the nozzle, the limit is about 10 mm.

The width of the sealant material other than the wide portion (the width of the sealant material other than the wide portion after application, the length indicated by _W0 in FIG. 6) is not particularly limited, but is preferably 0.8 mm or more, more preferably 1.3 mm or more, still more preferably 1.5 mm or more, more preferably 18 mm or less, more preferably 13 mm or less, still more preferably 9.0 mm or less, particularly preferably 7.0 mm or less, and most preferably 6.0 mm, because the effect is more preferably obtained. mm or less, more preferably 5.0 mm or less. W ₀ is preferably the same as W described above.

It should be noted that the width of the sealant material other than the wide portion is preferably substantially constant in the longitudinal direction, but there may be portions that are not substantially constant.

The width of the area where the sealant material is attached (hereinafter also referred to as the width of the attached area or the width of the sealant layer, and the length represented by W ₁ + 6 × W ₀ in FIG. 6) is not particularly limited, but the width is preferably 80% or more, more preferably 90% or more, even more preferably 100% or more, more preferably 120% or less, and more preferably 110% or less, because the effect is more preferably obtained.

The width of the sealant layer is preferably 85 to 115% of the tire breaker width (the length of the breaker in the tire width direction) for the reason that the effect can be obtained more favorably.

In the sealant tire of the second embodiment, the sealant material is preferably applied so as not to overlap in the width direction, and more preferably adhered without gaps.

In addition, in the sealant tire of the second embodiment, the other end of the sealant material in the length direction (the end corresponding to the attachment end portion) may also be a wide portion that is wider than the portion adjacent to it in the length direction.

The thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer, and the length indicated by D in FIG. 8) is not particularly limited, but is preferably 1.0 mm or more, more preferably 1.5 mm or more, still more preferably 2.0 mm or more, particularly preferably 2.5 mm or more, and is preferably 10 mm or less, more preferably 8.0 mm or less, and still more preferably 5.0 mm or less, because the effect is more preferably obtained.

The thickness of the sealant material (the thickness of the sealant material after application, the thickness of the sealant layer) is preferably substantially constant. As a result, deterioration of tire uniformity can be further prevented, and a sealant tire having a more excellent weight balance can be manufactured.

シーラント材の厚さ（塗布後のシーラント材の厚さ、シーラント層の厚さ、図８中、Ｄで示される長さ）と、シーラント材の幅広部以外の幅（塗布後のシーラント材の幅広部以外の幅、図６中、Ｗ _０で示される長さ）の比率（シーラント材の厚さ／シーラント材の幅広部以外の幅）は、好ましくは０．６以上、より好ましくは０．７以上、更に好ましくは０．８以上、特に好ましくは０．９以上であり、好ましくは１．４以下、より好ましくは１．３以下、更に好ましくは１．２以下、特に好ましくは１．１以下である。 The closer the ratio is to 1.0, the more ideal the shape of the sealant material is, the string-like shape, and the more productively the sealant tire with high sealability can be manufactured.

The cross-sectional area of the sealant material (the cross-sectional area of the sealant material after application, in FIG. 8, the area calculated by D×W) is preferably 0.8 mm ² or more, more preferably 1.95 mm ² or more, still more preferably 3.0 mm ² or more, particularly preferably 3.75 mm ² or more, preferably 180 mm 2 or less, more preferably 104 mm 2 or less, still more preferably 45 mm ² or less, and particularly preferably 45 mm ^{2 or less, because the effect can be obtained more preferably. 35 mm 2 or less} , most preferably 25 mm ^{2 or} less.

In the second embodiment, even if the viscosity of the sealant material is within the above range, particularly, even if the viscosity is relatively high, by widening the width of the sealant material corresponding to the attachment start portion, the adhesive strength of the portion can be improved and the peeling of the sealant material at the portion can be prevented.

The sealant tire of the second embodiment is preferably manufactured by the above manufacturing method, but may be manufactured by any other suitable manufacturing method as long as at least one end of the sealant material can be made into a wide portion.

In the above description, particularly in the description of the first embodiment, the case where the non-contact displacement sensor is used to apply the sealant material to the inner peripheral surface of the tire has been described. However, the sealant material may be applied to the inner peripheral surface of the tire by controlling the movement of the nozzle and/or the tire based on previously input coordinate values without performing measurement with the non-contact displacement sensor.

A sealant tire having a sealant layer produced using the rubber composition for a sealant material on the inner liner in the radial direction of the inner liner can be manufactured by the manufacturing method described above. Since the sealant layer of the pneumatic tire is produced using the rubber composition for a sealant material, it is excellent in sealing performance and flow resistance (shape retention performance).

It is preferable that the sealant layer is composed of a substantially string-shaped sealant material that is continuously spirally arranged along the inner peripheral surface of the tire, and that the substantially string-shaped sealant materials that are spirally arranged are more preferably arranged without overlapping in the width direction and without gaps.
The sealant tire having the above structure has a sealant layer in which the sealant material is uniform in the tire circumferential direction and the tire width direction (particularly, the tire circumferential direction) (a substantially string-shaped sealant layer arranged continuously along the inner circumferential surface of the tire in a spiral shape) on the inner circumferential surface of the tire, and thus has excellent sealing performance. In addition, the tire is less likely to be out of balance due to the sealant material, and deterioration of tire uniformity can be reduced.
Furthermore, the effect tends to be obtained more preferably by making the sealant layer produced using the above rubber composition for sealant material into the above structure. It is presumed that this is because the uniform thickness of the sealant layer is ensured, so that the effect is exhibited more preferably.
The sealant layer having the structure described above can be manufactured, for example, by applying a substantially string-shaped sealant material continuously and spirally to the inner peripheral surface of the tire.

定数
ｔ_０：基準時間＝１［分］
Ｅ：活性化エネルギー＝８３．７ｘ１０^３［Ｊ／ｍｏｌ］
Ｒ：気体定数＝８．３１４［Ｊ／ｍｏｌ・Ｋ］
Ｔ_０：基準温度＝４１４．８５［Ｋ］

変数
ｔ：架橋時間［分］
Ｔ：架橋中の架橋ゴムの測定温度［Ｋ］ The sealant layer is preferably a sealant layer obtained by completing the crosslinking reaction of the rubber composition for a sealant material with an ECU (amount of crosslinking) defined by the following formula of less than 0.10 ECU. The ECU (amount of cross-linking) defined by the following formula is more preferably 20 ECU or less, more preferably 10 ECU or less, particularly preferably 1 ECU or less, most preferably 0.50 ECU or less, preferably 0.01 ECU or more, more preferably 0.05 ECU or more, and still more preferably 0.10 ECU or more. Within the above range, a more suitable amount of cross-linking can be obtained, and the effect tends to be obtained more suitably.

Constant t ₀ : Reference time = 1 [minute]
E: activation energy = ^83.7x103 [J/mol]
R: gas constant = 8.314 [J / mol K]
T ₀ : Reference temperature = 414.85 [K]

Variable t: Cross-linking time [minutes]
T: Measured temperature of crosslinked rubber during crosslinking [K]

The ECU (amount of cross-linking) defined by the above formula can be adjusted by adjusting the cross-linking temperature (T) and the cross-linking time (t) in the cross-linking reaction of the rubber composition for sealant material.

The sealant layer is preferably a sealant layer obtained by completing the cross-linking reaction of the rubber composition for a sealant during kneading in a kneader such as a dynamic mixer or a static mixer. As a result, the cross-linking step becomes unnecessary, and there is a tendency that the effect can be obtained more favorably.
Since the rubber composition for a sealant material contains a specific cross-linking agent and a specific cross-linking accelerator for a rubber component containing a butyl-based rubber, a suitable cross-linking reaction rate can be obtained, the cross-linking reaction can proceed sufficiently, and the cross-linking reaction can be completed during kneading with a kneader such as a dynamic mixer or a static mixer.

The above tires are suitably used as passenger car tires, large passenger car tires, large SUV tires, truck and bus tires, motorcycle tires, competition tires, winter tires (studless tires, snow tires, stud tires), all-season tires, runflat tires, aircraft tires, mining tires, and the like.

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

Various chemicals used in the examples are described below.
Butyl rubber: Butyl 268 (manufactured by ExxonMobil, Mooney viscosity ML1+8=51 at 125° C., proportion of isoprene component (isoprene unit) in butyl rubber: 1.70 mol %)
Natural rubber: TSR20
Carbon black: Dia Black H (Mitsubishi Chemical Corporation, N330)
Crosslinking accelerator 1: Noxceler DM-P (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., di-2-benzothiazolyl disulfide (compound represented by the above formula (1)))
Crosslinking accelerator 2: Suncellar TBzTD (manufactured by Sanshin Chemical Co., Ltd., tetrabenzylthiuram disulfide (a compound in which R ³ to R ⁶ in the above formula (5) are phenyl groups))
Crosslinking accelerator 3: Zinc salt of 2-mercaptobenzothiazole (manufactured by Sanshin Chemical Co., Ltd., Suncellar MZ (compound represented by the above formula (2)))
Crosslinking accelerator 4: 2-mercaptobenzothiazole (manufactured by Kawaguchi Chemical Industry Co., Ltd., Accel M (compound represented by the above formula (3)))
Crosslinking accelerator 5: N-cyclohexyl-2-benzothiazolylsulfenamide (manufactured by Kawaguchi Chemical Industry Co., Ltd., Accel CZ (a compound of a cyclohexyl group in which R ¹ and R ² in the above formula (4) form a ring))
Cross-linking accelerator 6: Zinc dibenzyldithiocarbamate (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., Noxeler ZTC (a compound in which R ⁷ to R ¹⁰ in the above formula (6) are phenyl groups))
Crosslinking accelerator 7: 1,3-diphenylguanidine (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., Noxceler DP (a compound in which R ¹¹ and R ¹² in the above formula (7) are hydrogen atoms))
Liquid polybutene: Nisseki Polybutene HV1900 (manufactured by ENEOS Corporation, kinematic viscosity at 40°C: 160000 cSt, kinematic viscosity at 100°C: 3710 cSt, number average molecular weight: 2,900, weight average molecular weight (Mw): 9,500, content of isobutene skeleton in 100% by mass of liquid polybutene: 80% by mass)
Tackifier: Quintone A100 (manufactured by Nippon Zeon Co., Ltd., aliphatic petroleum resin)
Cross-linking agent 1: Actor DB (containing 25% by mass of p-dinitrosobenzene polymolecular) (manufactured by Kawaguchi Chemical Industry Co., Ltd.)
Cross-linking agent 2: Barnok GM-P (p-benzoquinonedioxime, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
Cross-linking agent 3: BENZOXE (containing 75% by mass of benzoyl peroxide) (manufactured by Kawaguchi Yakuhin Co., Ltd.)

<Manufacture of sealant tires>
According to the formulation contents shown in Table 1, kneading was performed under the conditions shown in Table 1 using a 3L kneader mixer to prepare a sealant material. Here, the cross-linking temperature and cross-linking time in the table correspond to the kneading temperature and kneading time, respectively.

Next, a sealant material (viscosity: 35,000 Pa s (40°C), approximately string-like shape, thickness: 3 mm, width: 4 mm) is successively prepared from a nozzle that is directly connected to the outlet of the mixer and whose tip is placed on the inner surface of the tire. It was applied (applied in a spiral shape) so as to have a width of 180 mm to form a sealant layer to produce a sealant tire. Also, the viscosity of the sealant material was measured with a rotary viscometer at 40° C. in accordance with JIS K 6833.
Here, the cross-linking curing reaction was advanced by heat generated during kneading.
The obtained test tires were used for the following evaluations, and the results are shown in Table 1.
Table 1 shows the ECU calculated based on the above formula.
In the rubber compositions for sealant materials of Examples, the cross-linking reaction was completed during kneading.

<Air seal performance>
The air seal success rate was measured when 100 nails of 5 mmφ x 30 mm length were driven into and removed from the sealant tire in a -10 ^° C constant temperature room. A higher air seal success rate indicates better sealing performance.

<Fluidity resistance (shape retention performance)>
The above-mentioned sealant tire was placed in an oven at 60° C. and placed horizontally for 7 days. When the flow of the sealant material was 10 mm or less, it was judged that the flow resistance performance (shape retention performance) was good.

From Table 1, the content of butyl rubber in 100% by mass of the rubber component is 5 to 100% by mass, and 0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of compounds represented by the above formulas (i) to (iii) and polymers thereof per 100 parts by mass of the rubber component, and 1 to 10 parts by mass of at least one cross-linking accelerator selected from the group consisting of the compounds represented by the above formulas (1) to (7). It was found to have excellent flow performance.

（式（４）中、Ｒ^１及びＲ^２は、同一又は異なって、アルキル基、又は水素原子を表し、Ｒ^１及びＲ^２は環を形成してもよい。）
（式（５）中、Ｒ^３～Ｒ^６は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（６）中、Ｒ^７～Ｒ^１０は、同一又は異なって、アルキル基、水素原子、又は芳香族炭化水素基を表す。）
（式（７）中、Ｒ^１１及びＲ^１２は、同一又は異なって、アルキル基、又は水素原子を表す。） In the present invention (1), the content of butyl rubber in 100% by mass of the rubber component is 5 to 100% by mass,
Per 100 parts by mass of the rubber component,
0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of compounds represented by the following formulas (i) to (iii) and polymers thereof;
A rubber composition for a sealant containing 1 to 10 parts by mass of at least one cross-linking accelerator selected from the group consisting of compounds represented by the following formulas (1) to (7).

(In formula (4), R ¹ and R ² are the same or different and represent an alkyl group or a hydrogen atom, and R ¹ and R ² may form a ring.)
(In formula (5), R ³ to R ⁶ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In Formula (6), R ⁷ to R ¹⁰ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In formula (7), R ¹¹ and R ¹² are the same or different and represent an alkyl group or a hydrogen atom.)

The present invention (2) is the rubber composition for a sealant according to the present invention (1), which contains 100 to 500 parts by mass of liquid polybutene per 100 parts by mass of the rubber component.

The present invention (3) is the rubber composition for a sealant according to the present invention (2), wherein the liquid polybutene has a number average molecular weight of 1,000 to 6,000 and a weight average molecular weight of 2,000 to 12,000.

The present invention (4) is the rubber composition for a sealant material according to the present invention (2) or (3), wherein the content of the isobutene skeleton is 90% by mass or less in 100% by mass of the liquid polybutene.

The present invention (5) is the rubber composition for sealant materials according to any one of the present inventions (1) to (4), wherein the proportion of the isoprene component in the butyl rubber is 1.00 mol % or more.

The present invention (6) is the rubber composition for a sealant material according to any one of the present inventions (1) to (5), wherein the sulfur content is 0.3 parts by mass or less per 100 parts by mass of the rubber component.

Invention (7) is a pneumatic tire having a sealant layer produced using the rubber composition according to any one of Inventions (1) to (6).

定数
ｔ_０：基準時間＝１［分］
Ｅ：活性化エネルギー＝８３．７ｘ１０^３［Ｊ／ｍｏｌ］
Ｒ：気体定数＝８．３１４［Ｊ／ｍｏｌ・Ｋ］
Ｔ_０：基準温度＝４１４．８５［Ｋ］

変数
ｔ：架橋時間［分］
Ｔ：架橋中の架橋ゴムの測定温度［Ｋ］ The present invention (8) is the pneumatic tire according to the present invention (7), wherein the sealant layer is a sealant layer obtained by completing the crosslinking reaction of the rubber composition at an ECU of less than 0.10 ECU defined by the following formula.

Constant t ₀ : Reference time = 1 [minute]
E: activation energy = ^83.7x103 [J/mol]
R: gas constant = 8.314 [J / mol K]
T ₀ : Reference temperature = 414.85 [K]

Variable t: Cross-linking time [minutes]
T: Measured temperature of crosslinked rubber during crosslinking [K]

The present invention (9) is the pneumatic tire according to the present invention (7) or (8), wherein the sealant layer is a sealant layer obtained by completing the crosslinking reaction of the rubber composition during kneading in a dynamic mixer or a static mixer.

10 Tire 11 Tire inner peripheral surface 14 Tread portion 15 Carcass 16 Breaker 17 Band 20 Sealant material 21 Wide portion 30 Nozzle 31 Nozzle tip 40 Non-contact displacement sensor 50 Rotary drive device 60 Twin-screw kneading extruder 61 (61a 61b 61c) Supply port 62 Material feeder d, d ₀ , d ₁ , d ₂ Tire inner peripheral surface and nozzle tip the distance of

Claims (9)

The content of butyl rubber in 100% by mass of the rubber component is 5 to 100% by mass,
Per 100 parts by mass of the rubber component,
0.5 to 10 parts by mass of at least one cross-linking agent selected from the group consisting of compounds represented by the following formulas (i) to (iii) and polymers thereof;
A rubber composition for a sealant containing 1 to 10 parts by mass of at least one cross-linking accelerator selected from the group consisting of compounds represented by the following formulas (1) to (7).

(In formula (4), R ¹ and R ² are the same or different and represent an alkyl group or a hydrogen atom, and R ¹ and R ² may form a ring.)
(In formula (5), R ³ to R ⁶ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In Formula (6), R ⁷ to R ¹⁰ are the same or different and represent an alkyl group, a hydrogen atom, or an aromatic hydrocarbon group.)
(In formula (7), R ¹¹ and R ¹² are the same or different and represent an alkyl group or a hydrogen atom.) The rubber composition for a sealant material according to claim 1, containing 100 to 500 parts by mass of liquid polybutene with respect to 100 parts by mass of the rubber component. 3. The rubber composition for a sealant material according to claim 2, wherein the liquid polybutene has a number average molecular weight of 1,000 to 6,000 and a weight average molecular weight of 2,000 to 12,000. The rubber composition for a sealant material according to claim 2, wherein the content of the isobutene skeleton is 90% by mass or less in 100% by mass of the liquid polybutene. 2. The rubber composition for a sealant material according to claim 1, wherein the ratio of the isoprene component in said butyl rubber is 1.00 mol % or more. 2. The rubber composition for a sealant according to claim 1, wherein the sulfur content is 0.3 parts by mass or less per 100 parts by mass of the rubber component. A pneumatic tire having a sealant layer produced using the rubber composition according to any one of claims 1 to 6. 8. The pneumatic tire according to claim 7, wherein the sealant layer is a sealant layer obtained by completing the crosslinking reaction of the rubber composition at an ECU of less than 0.10 ECU defined by the following formula.

Constant t ₀ : Reference time = 1 [minute]
E: activation energy = ^83.7x103 [J/mol]
R: gas constant = 8.314 [J / mol K]
T ₀ : Reference temperature = 414.85 [K]

Variable t: Cross-linking time [minutes]
T: Measured temperature of crosslinked rubber during crosslinking [K] 8. The pneumatic tire according to claim 7, wherein the sealant layer is obtained by completing the cross-linking reaction of the rubber composition during kneading with a dynamic mixer or a static mixer.

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