JP2022054937A - Self-seal tire - Google Patents

Abstract

To provide a self-seal tire that includes an adhesive sealing layer having excellent flow resistance, while maintaining excellent sealability.SOLUTION: A self-seal tire has an adhesive sealing layer in an inner surface of the tire. The adhesive sealing layer is formed from a composition for adhesive sealing layers, the composition containing a rubber component, a polymer having more than one hydrolytic condensable silicon groups on average in each molecule, a plasticizer, and a condensation catalyst.SELECTED DRAWING: Figure 1

Description

The present invention relates to a self-sealing tire.

Conventionally, a self-sealing tire having an adhesive sealing layer (sealant) on the inner surface of the tire is known. The adhesive sealing layer can be formed by using a composition containing a rubber-based material.
In the self-sealing tire, even when a nail or the like pierces the tire and a through hole is formed, the adhesive sealing layer flows into the through hole to seal the through hole, and it is possible to suppress a decrease in the internal pressure of the tire. Performance, that is, sealing performance is required.
Further, the self-sealing tire is required to have a performance that the sealant does not flow toward the tire center side due to the influence of heat and centrifugal force applied during traveling, that is, flow resistance. This is because if the sealant flows during traveling, the sealing property may be deteriorated.

For example, Patent Document 1 describes a sealant on the inner surface of a tire for the purpose of providing a sealant material composition and a pneumatic tire that can ensure good sealing performance and suppress the flow of the sealant during running. A sealant material composition constituting a sealant layer of a pneumatic tire provided with a layer, wherein 0.1 part by mass to 20 parts by mass of a cross-linking agent and 0.1 mass by mass of an organic peroxide with respect to 100 parts by mass of a rubber component. A sealant material composition comprising 40 parts by mass to 40 parts by mass and 10 parts by mass to 400 parts by mass of a liquid polymer is described.

Japanese Unexamined Patent Publication No. 2019-162847

Under these circumstances, the present inventors prepared and evaluated a sealant composition containing a rubber component and the like with reference to Patent Document 1, and found that the adhesive sealing layer obtained from such a composition had flow resistance. Regarding the sex, it was considered that there is room for improvement from a viewpoint different from that of Patent Document 1.
Therefore, an object of the present invention is to provide a self-sealing tire having excellent flow resistance of the adhesive sealing layer while maintaining good sealing property.

As a result of diligent research to solve the above problems, the present inventors have found that the adhesive sealing layer of the self-sealing tire has a rubber component and more than one hydrolysis-condensable silicon group in one molecule on average. It has been found that, by being formed by a composition containing a polymer, a plasticizer, and a condensation catalyst, the effect of excellent flow resistance of the adhesive sealing layer can be obtained while maintaining good sealing properties. , Which led to the present invention.
The present invention is based on the above findings and the like, and specifically solves the above problems by the following configurations.

[1] The adhesive sealing layer is provided on the inner surface of the tire, and the adhesive sealing layer is formed.
With the rubber component,
A polymer having more than one hydrolyzable and condensable silicon group in one molecule on average,
With a plasticizer,
A self-sealing tire formed by a composition for an adhesive sealing layer containing a condensation catalyst.
[2] The self-sealing tire according to [1], wherein the composition for an adhesive sealing layer is hydrolyzed, condensed and crosslinked by moisture.
[3] The composition for the adhesive sealing layer is partially crosslinked with moisture in advance, and then the partially crosslinked composition for the adhesive sealing layer is placed on the inner surface of the tire and further crosslinked. [1] or [ 2] The self-sealing tire described in.
[4] The self-sealing tire according to any one of [1] to [3], wherein the polymer contains a polyolefin having a trialkoxysilyl group in the side chain.
[5] The self-seal according to any one of [1] to [4], wherein the polymer contains a (meth) acrylic polymer having more than one hydrolyzable condensable silicon group in one molecule on average. tire.
[6] The self-sealing tire according to any one of [1] to [5], wherein the rubber component contains at least one selected from the group consisting of natural rubber, styrene-butadiene rubber, butadiene rubber and isoprene rubber.
[7] The self-sealing tire according to any one of [1] to [6], wherein the plasticizer contains at least one selected from the group consisting of polybutene, process oil and ester-based plasticizer.
[8] The self-sealing tire according to any one of [1] to [7], wherein the content of the polymer is 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component.
[9] The self-sealing tire according to any one of [1] to [8], wherein the content of the plasticizer is 50 to 400 parts by mass with respect to 100 parts by mass of the rubber component.

The self-sealing tire of the present invention has excellent flow resistance of the adhesive sealing layer while maintaining good sealing properties.

FIG. 1 is a cross-sectional view taken along the meridian diagram schematically showing an example of the self-sealing tire of the present invention.

The present invention will be described in detail below.
In the present specification, (meth) acrylate represents acrylate or methacrylate, and (meth) acrylic represents acrylic or methacrylic.
Further, the numerical range represented by using "-" in the present specification means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.
In the present specification, unless otherwise specified, each component may be used alone or in combination of two or more kinds of substances corresponding to the component. When a component contains two or more substances, the content of the component means the total content of the two or more substances.
In the present specification, it is said that the effect of the present invention is more excellent when at least one of the sealing property and the flow resistance of the adhesive sealing layer is more excellent.

[Self-sealing tires]
The self-sealing tire of the present invention (the tire of the present invention) is
The adhesive sealing layer has an adhesive sealing layer on the inner surface of the tire, and the adhesive sealing layer is
With the rubber component,
A polymer having more than one hydrolyzable and condensable silicon group in one molecule on average,
With a plasticizer,
A self-sealing tire formed by a composition for an adhesive sealing layer containing a condensation catalyst.

In the present specification, a polymer having more than one hydrolytically condensable silicon group in one molecule on average may be referred to as a "specific polymer".

Since the tire of the present invention has such a configuration, it is considered that a desired effect can be obtained. The reason is not clear, but it is presumed to be as follows.
Since the composition for the adhesive sealing layer forming the adhesive sealing layer of the self-sealing tire of the present invention contains a specific polymer, the composition for the adhesive sealing layer comes into contact with moisture (for example, moisture in the air). Then, the silicon group of the specific polymer is hydrolyzed and condensed, and the specific polymer is crosslinked to form an adhesive sealing layer. It is considered that the composition for the adhesive sealing layer can be cured to the extent that the flow resistance of the adhesive sealing layer is improved while maintaining the sealing property even after the specific polymer is crosslinked.
In the present invention, the adhesive sealing layer composition newly forms a hydrolyzable condensable silicon group crosslink to the rubber component, which is different from the crosslink with sulfur, while maintaining the sealing property. , It is considered that the adhesive sealing layer has excellent flow resistance.
It should be noted that the above mechanism is a guess of the present inventors, and the mechanism of the present invention is not limited to the above.
Hereinafter, the tire of the present invention will be described in detail.

(Basic structure of tire)
The portion (tire itself) other than the adhesive sealing layer of the self-sealing tire of the present invention may be referred to as "the basic structure of the tire".
Examples of the basic structure of the tire include a pneumatic tire, specifically, for example, a tread portion extending in the tire circumferential direction to form an annular shape, and a pair of sides arranged on both sides of the tread portion. Examples thereof include a pneumatic tire including a wall portion and a pair of bead portions arranged inside the sidewall portions in the tire radial direction. The basic structure of the tire may further have an inner liner layer, for example, on the inner peripheral surface (innermost layer) of the tire.
In the present invention, the inner surface of the tire refers to the inner surface of the basic structure of the tire (the tire itself).

<Adhesive sealing layer>
The self-sealing tire of the present invention has an adhesive sealing layer on the inner surface of the tire. Further, in the present invention, the adhesive sealing layer is formed by the composition for an adhesive sealing layer described later.

From the viewpoint that the effect of the present invention is more excellent, the self-sealing tire of the present invention preferably has an adhesive sealing layer at least on the inner surface of the tire (the surface of the inner portion in the radial direction of the tire) in the tread portion. The adhesive sealing layer in the tread portion may be further present on the inner surface of the tire of the sidewall portion (continuously and integrally with the adhesive sealing layer in the tread portion).
Further, it is one of the preferable embodiments that the adhesive sealing layer is provided on the inner liner layer on the inner surface of the tire.
It is preferable that the inner liner layer contains a halogenated butyl rubber. This is because the adhesiveness between the inner liner layer and the adhesive sealing layer can be improved.

Hereinafter, the configuration of the self-sealing tire of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the accompanying drawings.
FIG. 1 is a cross-sectional view taken along the meridian diagram schematically showing an example of the self-sealing tire of the present invention.
As shown in FIG. 1, the self-sealing tire 20 has a tread portion 1 extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a sidewall portion 2. It is provided with a pair of bead portions 3 arranged inside the tire radial direction of the tire. In FIG. 1, the reference numeral CL indicates the tire equator. Although FIG. 1 is a cross-sectional view of the meridian, the tread portion 1, the sidewall portion 2, and the bead portion 3 each extend in the tire circumferential direction to form an annular shape, whereby the toroidal of the tire is formed. The basic structure of the shape is constructed. Further, the other tire components in the meridian cross section also extend in the tire circumferential direction to form an annular shape unless otherwise specified.

In the example of FIG. 1, a carcass layer 4 is mounted between the pair of left and right bead portions 3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the inside to the outside of the vehicle around the bead core 5 and the bead filler 6 arranged in each bead portion 3. The bead filler 6 is arranged on the outer peripheral side of the bead core 5, and is wrapped by the main body portion and the folded portion of the carcass layer 4.
A plurality of belt layers 7 (7a, 7b) are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. A belt reinforcing layer 8 is provided on the outer peripheral side of the belt layer 7 in the tread portion 1. In the illustrated example, two belt reinforcing layers 8 are provided, one is a full cover layer covering the entire width of the belt layer 7, and the other is an edge cover layer arranged on the outer peripheral side of the full cover layer and covering only the end portion of the belt layer 7. ing.

In FIG. 1, an inner liner layer 9 is provided inside the tire along the carcass layer 4. The inner liner layer 9 is a layer for preventing air or the like filled in the tire from permeating to the outside of the tire.

In FIG. 1, an adhesive sealing layer 10 is provided on the inner surface of the tire (more specifically, inside the inner liner layer 9 in the tread portion 1 in the radial direction of the tire).

The adhesive sealing layer 10 preferably has a thickness of, for example, 0.5 mm to 5.0 mm. By having such a thickness, the effect of the present invention is more excellent. In addition, the workability when the adhesive sealing layer 10 is provided is also improved. The thickness of the adhesive sealing layer 10 is an average thickness.

For example, when a nail or the like pierces the tread portion 1, the sealant material constituting the adhesive sealing layer 10 flows into the through hole, whereby a decrease in air pressure can be suppressed and running can be maintained.

<< Composition for adhesive sealing layer >>
In the present invention, the adhesive sealing layer is formed by the composition for the adhesive sealing layer.
<Rubber component>
Examples of the rubber component contained in the composition for the adhesive sealing layer include natural rubber and synthetic rubber.
In the present invention, it is preferable that the rubber component is a solid under the condition of 23 ° C.
Further, it is preferable that the rubber component does not have a hydrolyzable condensable silicon group.
Examples of the rubber component include diene-based rubber, and more specifically, examples thereof include natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, and halogenated butyl rubber.

From the viewpoint that the effect of the present invention is more excellent, the rubber component preferably contains at least one selected from the group consisting of natural rubber, styrene-butadiene rubber, butadiene rubber and isoprene rubber, and the natural rubber or styrene-butadiene rubber is preferably contained. It is more preferable to include it.

The natural rubber (NR) is not particularly limited. For example, conventionally known ones can be mentioned.
The styrene-butadiene rubber (SBR) is not particularly limited as long as it is a copolymer of styrene and butadiene. For example, conventionally known ones can be mentioned.

The weight average molecular weight (Mw) of the rubber component is preferably 400,000 to 1,000,000 from the viewpoint that the effect of the present invention is more excellent.
The weight average molecular weight of the rubber component can be a standard polystyrene-equivalent value obtained by gel permeation chromatography (GPC) measurement under the following conditions.
・ Solvent: Tetrahydrofuran ・ Detector: RI detector

<Specific polymer>
In the present invention, the specific polymer contained in the composition for the adhesive sealing layer is a polymer having more than one hydrolyzable condensable silicon group in one molecule on average.
In the present invention, the specific polymer includes the concept of an oligomer having more than one hydrolyzable condensable silicon group in one molecule on average.

<Hydrolyzed and condensable silicon group>
In the present invention, the specific polymer has a hydrolyzable and condensable silicon group.
The hydrolyzable and condensable silicon group means a hydrolyzable group (hydrolyzable group) or a silicon group having a condensable group.
Examples of the silicon group (hydrolyzable silyl group) having a hydrolyzable group (hydrolyzable group) include a halide silyl group, an alkoxysilyl group, an acyloxysilyl group, and an aminooxysilyl group. A silicon group having a hydrolyzable group (hydrolyzable group) can become a silicon group having a group capable of condensation (for example, a silanol group) after hydrolysis.
Examples of the silicon group having a group capable of condensation include a silanol group. In addition, the silicon group having a hydrolyzable group can be hydrolyzed to form a silanol group.
The hydrolyzable and condensable silicon group is preferably an alkoxysilyl group from the viewpoint that the effect of the present invention is more excellent.

-Alkoxysilyl group Examples of the alkoxysilyl group include a monoalkoxysilyl group, a dialkoxysilyl group, and a trialkoxysilyl group.
As the alkoxysilyl group, a dialkoxysilyl group and a trialkoxysilyl group are preferable, and a trialkoxysilyl group is more preferable, from the viewpoint that the effect of the present invention is more excellent.
When the alkoxysilyl group is a monoalkoxysilyl group or a dialkoxysilyl group, examples of the group that can be further bonded (other than the alkoxy group) to the silicon atom in the alkoxysilyl group include a hydrocarbon group. Examples of the hydrocarbon group include an aliphatic hydrocarbon group (including linear, branched and cyclic), an aromatic hydrocarbon group, and a combination thereof. The hydrocarbon group is preferably an alkyl group as one of the preferred embodiments.
Examples of the dialkoxysilyl group include a dimethoxysilyl group and a diethoxysilyl group.
Examples of the trialkoxysilyl group include a trimethoxysilyl group and a triethoxysilyl group.

-Main chain of specific polymer Examples of the main chain of the specific polymer include polyolefins, (meth) acrylic polymers, polyoxyalkylenes, and polyesters. The main chain portion of the specific polymer may be either a homopolymer or a copolymer.
Examples of the polyolefin include polymers of olefins such as ethylene and propylene.
Examples of the (meth) acrylic polymer include polymers having repeating units with (meth) acrylate.
Examples of the polyoxyalkylene include a polymer having an oxyalkylene group such as an oxyethylene group and an oxypropylene group as a repeating unit.
The main chain of the specific polymer is preferably a polyolefin or (meth) acrylic polymer, more preferably a polymer having a repeating unit of polyolefin or (meth) acrylate, and further preferably a polyolefin, from the viewpoint of more excellent effect of the present invention. ..

-Bond position of hydrolyzable condensable silicon group The specific polymer may have a hydrolyzable condensable silicon group at the end and / or side chain of the specific polymer (that is, the end and / or side chain of the main chain). can.
From the viewpoint that the effect of the present invention is more excellent, the specific polymer preferably has a hydrolyzable condensable silicon group in the side chain. When the specific polymer has a hydrolyzable condensable silicon group in the side chain, it may further have a hydrolyzable condensable silicon group at the end.

In a particular polymer, the hydrolyzable and condensable silicon group can be attached to the backbone of the particular polymer either directly or via an organic group. The organic group is not particularly limited.

The specific polymer may be, for example, a graft polymer. When the specific polymer is a graft polymer, for example, a graft polymer obtained by grafting a vinyl-based monomer to various polymers as the main chain of the specific polymer can be mentioned. Examples of the vinyl-based monomer include a vinyl-based monomer having a hydrolyzable and condensable silicon group. The above-mentioned graft can introduce a hydrolyzable and condensable silicon group into the side chain of a specific polymer.
Examples of the vinyl-based monomer having a hydrolyzable condensable silicon group include a vinyl compound having a hydrolyzable condensable silicon group and a vinyl group (for example, trialkoxysilylvinyl).
In the present invention, the method for introducing a hydrolytically condensable silicon group into the side chain of a specific polymer is not limited to grafting.

<Number of hydrolyzable and condensable silicon groups>
The specific polymer has more than one hydrolytically condensable silicon group in one molecule on average.
The number of hydrolyzable and condensable silicon groups contained in one molecule of the specific polymer is preferably 2 to 20 from the viewpoint that the effect of the present invention is more excellent.

The specific polymer is a graft polymer obtained by grafting a vinyl-based monomer having a hydrolyzable and condensable silicon group to a polyolefin from the viewpoint that the effect of the present invention is more excellent (the above-mentioned graft polymer is contained in one molecule). Has an average of more than one hydrolyzable condensable silicon group; the same applies hereinafter) and / or a (meth) acrylic polymer having an average of more than one hydrolyzable condensable silicon group in one molecule. Is preferable, and a graft polymer obtained by grafting a vinyl-based monomer having a hydrolyzable condensable silicon group to a polyolefin and / or a hydrolyzable condensable silicon group in one molecule on average. It is more preferable to contain a poly (meth) acrylate having more than one and at least a part of the silicon group bonded to the side chain.
Further, from the viewpoint that the effect of the present invention is more excellent, the specific polymer is a polyolefin having a trialkoxysilyl group in the side chain (the above-mentioned polyolefin contains one hydrolysis-condensable silicon group including the above-mentioned trialkoxysilyl group). It suffices to have more than one in the molecule on average, and all hydrolyzable and condensable silicon groups may be trialkoxysilyl groups) and / or hydrolyzed and condensable in one molecule. It is preferable to contain a (meth) acrylic polymer having more than one silicon group on average, and a polyolefin having an average of more than one trialkoxysilyl group in one molecule in the side chain, and / or one molecule. It is more preferable to contain a poly (meth) acrylate having more than one hydrolyzable and condensable silicon group on average and at least a part of the silicon groups bonded to the side chain.

-Molecular Weight of Specific Polymer The weight average molecular weight (Mw) of the specific polymer is preferably 10,000 to 200,000 from the viewpoint that the effect of the present invention is more excellent.
The method for measuring the weight average molecular weight of the specific polymer is the same as the above-mentioned method for measuring the weight average molecular weight of the rubber component.

The method for producing the specific polymer is not particularly limited. For example, a conventionally known method can be mentioned.

(Combination of rubber component and specific polymer)
The combination of the above rubber component and the specific polymer is at least one selected from the group consisting of natural rubber, styrene butadiene rubber, butadiene rubber and isoprene rubber as the rubber component from the viewpoint that the effect of the present invention is more excellent. , As a specific polymer, a combination with a polymer having a hydrolyzable condensable silicon group in the side chain is preferable, and a natural rubber and / or styrene-butadiene rubber as the rubber component and a trialkoxysilyl group as the specific polymer are preferable. Is more preferable in combination with a polymer having a side chain.

-Content of Specific Polymer The content of the specific polymer is preferably 10 to 100 parts by mass, preferably 25 to 40 parts by mass, with respect to 100 parts by mass of the rubber component, from the viewpoint that the effect of the present invention is more excellent. Is more preferable.

<Plasticizer>
In the present invention, the plasticizer contained in the composition for the adhesive sealing layer is not particularly limited as long as it can soften the rubber component or reduce the hardness of the rubber component.
It is preferable that the plasticizer is liquid under the condition of 23 ° C.
It is preferable that the plasticizer does not have a hydrolyzable condensable silicon group.

The plasticizer preferably contains at least one selected from the group consisting of polybutenes, process oils and ester plasticizers from the viewpoint of more excellent effects of the present invention and excellent processability, and polybutenes and / or processes. It is more preferable to contain oil, and even more preferably to contain process oil.
The plasticizer may be appropriately selected in combination with the rubber component.

Examples of the polybutene include isobutene and normal butene homopolymers and isobutene-isoprene copolymers, respectively.
Examples of the process oil include paraffin-based oils, naphthenic-based oils, aroma-based (aromatic) oils, and the like.
Examples of the ester-based plasticizer include phthalates such as dioctylphthalate (DOP), diisononyl phthalate, and diisononyl phthalate, adipates, and fatty acid esters.
In the present invention, when oil-added rubber is used as the above-mentioned rubber component, the oil in the oil-added rubber is included in the above-mentioned plasticizer. When oil-added rubber is used as the above-mentioned rubber component, the content of the plasticizer described later shall include the oil in the oil-added rubber.

The weight average molecular weight (Mw) of the plasticizer is preferably less than 400,000, more preferably 400 to 100,000, from the viewpoint of more excellent effects of the present invention and excellent processability.
When the plasticizer is a polymer compound (for example, polybutene, process oil, etc.), the method for measuring the weight average molecular weight thereof is the same as the method for measuring the weight average molecular weight of the rubber component described above.

-Content of Plasticizer The content of the plasticizer is preferably 50 to 400 parts by mass with respect to 100 parts by mass of the rubber component from the viewpoint that the effect of the present invention is more excellent and the processability is excellent. , 150-350 parts by mass is more preferable.

The content of the plasticizer is preferably 350 to 800 parts by mass, and 500 to 750 parts by mass with respect to 100 parts by mass of the specific polymer, from the viewpoint that the effect of the present invention is more excellent and the processability is excellent. Is more preferable.

<Condensation catalyst>
In the present invention, the condensation catalyst contained in the composition for the adhesive sealing layer is not particularly limited as long as it is a compound that can contribute to the condensation of the hydrolyzable and condensable silicon groups of the specific polymer.
Examples of the condensation catalyst include a silanol condensation catalyst (a catalyst capable of promoting a dehydration condensation reaction between silanol groups formed by hydrolysis of the silicon group or the like).
Specific examples of the condensation catalyst include tin compounds, amines, titanium compounds, and aluminum compounds.
As the condensation catalyst, tin compounds and amines are preferable, and tin compounds are more preferable, from the viewpoint that the effect of the present invention is more excellent.

Examples of the tin-based compound include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diethylhexanoate, dibutyltin dioctate, dibutyltin dimethylmalate, dibutyltin diethylmalate, dibutyltin dibutylmalate, and dibutyltin diiso. Octylmalate, dibutyltin ditridecylmalate, dibutyltin dibenzylmalate, dibutyltin maleate, dioctyltin diacetate, dioctyltin distearate, dioctyltin dilaurate, dioctyltin diethylmalate, dioctyltin diisooctylmalate, etc. Dialkyltin Dicarboxylates; Dialkyltin dialcoxides; Examples thereof include divalent tin compounds such as tin octylate, tin naphthenate, tin stearate and tin ferzaticate.

Examples of amines include aliphatic primary amines such as methylamine, ethylamine, propylamine, octylamine and 2-ethylhexylamine; aliphatic secondary amines such as dimethylamine and diethylamine; triamylamine and trihexyl. Aliphatic tertiary amines such as amines; aliphatic unsaturated amines such as triallylamine and oleylamine; aromatic amines such as laurylaniline, stearylaniline and triphenylamine; other amines include monoethanolamine and ethylenediamine. , Morphorin, N-methylmorpholin, 1,8-diazabicyclo (5,4,0) undecene-7 (DBU).

-Content of Condensation Catalyst The content of the condensation catalyst is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the specific polymer from the viewpoint that the effect of the present invention is more excellent.

(Additive)
In addition to the above components, the composition for the adhesive sealing layer may further contain, for example, an additive, if necessary. Examples of the additive include fillers (eg, carbon black, silica, calcium carbonate, hollow fillers), tackifiers, dehydrating agents such as vinyltrimethoxysilane, vulcanizing agents such as sulfur, vulcanization accelerators, and the like. Examples include zinc oxide, stearic acid, antioxidants, antioxidants, UV absorbers, flame retardants, surfactants, dispersants, antioxidants and the like.

-Tackifire The tackyfire that can be further contained in the above-mentioned adhesive sealing layer composition is not particularly limited. Examples thereof include C5 resin, C9 resin, C5 to C9 resin, dicyclopentadiene resin, rosin resin, alkylphenol resin, and terpene phenol resin.
The content of the adhesive bandage is 100 parts by mass of the composition for the adhesive sealing layer (the content of the adhesive bandage is not included in the above) from the viewpoint that the effect of the present invention is more excellent and the adhesion to the tire is excellent. ), 50 to 100 parts by mass is preferable.

-Carbon Black When the composition for the adhesive sealing layer further contains carbon black, it is preferable from the viewpoint that the composition for the adhesive sealing layer can be made into a paste and the adhesive sealing layer can be efficiently thickened.
The carbon black that can be further contained in the adhesive sealing layer composition is not particularly limited.
The content of the carbon black is 100 parts by mass of the composition for the adhesive sealing layer (the content of the carbon black is not included in the above) from the viewpoint that the effect of the present invention is more excellent and the adhesion to the tire is excellent. ), 0.1 to 20 parts by mass is preferable.

-Hollow filler When the composition for the adhesive sealing layer further contains the hollow filler, it is preferable because the adhesive sealing layer can be made lighter and the fuel efficiency of the tire is excellent.
The hollow filler that can be further contained in the adhesive sealing layer composition is not particularly limited. For example, a glass balloon and a resin balloon can be mentioned.

-Dehydrating agent When the composition for the adhesive sealing layer further contains a dehydrating agent such as vinyltrimethoxysilane, the content of the dehydrating agent is superior from the viewpoint of the effect of the present invention and excellent processability. , 1 to 8 parts by mass is preferable with respect to 100 parts by mass of the rubber component.

-Vulcanizing agent When the composition for the adhesive sealing layer further contains a vulcanizing agent such as sulfur, the content of the vulcanizing agent is superior from the viewpoint of the effect of the present invention and excellent processability. , 0.1 to 2 parts by mass is preferable with respect to 100 parts by mass of the rubber component.

(Manufacturing method of composition for adhesive sealing layer)
The composition for an adhesive sealing layer can be produced by mixing the essential components and, if necessary, additives that can be contained. The mixing method and conditions are not particularly limited.

-Viscosity of the composition for the adhesive sealing layer The viscosity of the composition for the adhesive sealing layer is more excellent in the effect of the present invention and is processable (for example, as will be described later, the composition for the adhesive sealing layer is used as a tire. From the viewpoint of being excellent in stable application, etc.), the complex viscosity at 100 ° C. is preferably 100 to 5000 Pa · s. In the present invention, the complex viscosity is determined by shear dynamic viscoelasticity measurement under the conditions of a temperature of 100 ° C. and a frequency of 1 Hz (the same applies hereinafter).
The details of the above viscosity measurement conditions are as follows (the same applies hereinafter).
Viscosity measurement method:
Equipment: TA Instruments rheometer ARES G2
Jig: 25mm Parallel plate Sample thickness: 1.5mm
Frequency: 1Hz (amplitude)
Distortion: 0.1%
Temperature: 100 ° C

(Manufacturing method of self-sealing tires)
Examples of the method for manufacturing a self-sealing tire of the present invention include a method having an installation step of installing the composition for an adhesive sealing layer on the inner surface of the tire.
The tire (tire having a basic structure) and the composition for the adhesive sealing layer used in the above manufacturing method are the same as described above. In the above manufacturing method, the tire after vulcanization can be used.

-Installation process In the above installation process, the method of installing the adhesive sealing layer composition on the inner surface of the tire is not particularly limited. For example, a conventionally known method can be mentioned. Specifically, for example, a method of supplying (specifically, for example, applying) the composition for the adhesive sealing layer with a nozzle; the composition for the adhesive sealing layer in the form of a tape or a sheet is attached on the inner surface of the tire. The method can be mentioned.
From the viewpoint that the effect of the present invention is more excellent, it is preferable to continuously install the composition for the adhesive sealing layer on the inner surface of the tire. Continuously installing the composition for the adhesive sealing layer means that the composition for the adhesive sealing layer is not interrupted during the installation.

When the nozzles are used when the composition for the adhesive sealing layer is installed on the tire, the number of nozzles to be used may be one or more.

From the viewpoint that the effect of the present invention is more excellent, for example, the composition for the adhesive sealing layer is spirally formed on the inner surface of the tire (that is, along the inner peripheral surface of the tire, on the tire equatorial line shown in FIG. 1). It is preferable to install it so as to draw a circle in the direction parallel to it.
In the composition for the adhesive sealing layer installed in a spiral shape (for example, coating and pasting), it is preferable that there is no gap between the adjacent compositions for the adhesive sealing layer (lines).

When the composition for the adhesive sealing layer is installed on the tire, the composition for the adhesive sealing layer can be heated. The heating can be, for example, 100 to 220 ° C.
The viscosity of the composition for the adhesive sealing layer after heating as described above is preferably 100 to 5000 Pa · s at a complex viscosity at 100 ° C. from the viewpoint that the effect of the present invention is more excellent and the processability is excellent. ..

-Crosslinking The composition for the adhesive sealing layer can be hydrolyzed and condensed with water (hydrolyzed and condensed with water) and crosslinked.
When the composition for the adhesive sealing layer comes into contact with moisture (for example, moisture in the air), the silicon groups of the specific polymer are hydrolyzed and condensed to crosslink the specific polymer, and the composition for the adhesive sealing layer is used. It can be crosslinked as a whole to form an adhesive sealing layer.
The conditions for cross-linking the adhesive sealing layer composition with moisture are not particularly limited. For example, the composition for an adhesive sealing layer can be crosslinked under the conditions of 10 to 50 ° C. and 20 to 60% RH.
In the method for producing a self-sealing tire of the present invention, the timing at which the composition for an adhesive sealing layer is hydrolyzed and condensed with moisture (for example, moisture) and crosslinked is not particularly limited.
The composition for an adhesive sealing layer may be crosslinked in an environment with moisture (for example, moisture) after the installation step. The composition for the adhesive sealing layer may be crosslinked, for example, while the tire on which the composition for the adhesive sealing layer is installed is stored.

Before the installation step, the composition for the adhesive sealing layer may be crosslinked with moisture (for example, moisture) in advance and then installed on the inner surface of the tire.
When the composition for the adhesive sealing layer is cross-linked in advance with moisture (for example, moisture or the like), the composition for the adhesive sealing layer can be cross-linked under the conditions of, for example, 10 to 50 ° C. and 20 to 60% RH.

Further, from the viewpoint that the effect of the present invention is more excellent, the composition for the adhesive sealing layer is partially crosslinked with water (for example, moisture) in advance, and then the partially crosslinked composition for the adhesive sealing layer is applied to the inner surface of the tire. One of the preferred embodiments is to install and further crosslink.
In the present invention, the partial cross-linking of the composition for an adhesive sealing layer means that a part of the hydrolyzable and condensable silicon groups of the specific polymer is cross-linked.
The conditions for preliminarily cross-linking the composition for the adhesive sealing layer with moisture (for example, moisture) can be the same as described above.
When the partially crosslinked adhesive sealing layer composition is placed on the inner surface of the tire and then crosslinked, the adhesive sealing layer composition may be further crosslinked under the conditions of, for example, 10 to 50 ° C. and 20 to 60% RH. can.
The viscosity of the composition for the adhesive sealing layer after the partial cross-linking is preferably 500 to 6000 Pa · s at a complex viscosity at 100 ° C. from the viewpoint that the effect of the present invention is more excellent and the processability is excellent.

Further, after installing the composition for the adhesive sealing layer on the inner surface of the tire, the step of leveling the adhesive sealing layer with a pressing roller may be further provided. Further having the above steps is preferable from the viewpoint of being more excellent in sealing property.
Examples of the pressing roller include a pressing roller having a roller portion whose surface is made of a material having a water contact angle of 70 degrees or more.

Further, the adhesive sealing layer may further have a step of post-treating the adhesive sealing layer from the viewpoint of excellent foreign matter adhesion resistance of the adhesive sealing layer. Examples of the post-treatment include physical action on the surface of the adhesive sealing layer (for example, collision of powder) and adhesion of powder to the surface of the adhesive sealing layer.
The tack on the surface of the adhesive sealing layer is preferably 2N or less from the viewpoint of excellent foreign matter adhesion resistance of the adhesive sealing layer. The tack on the surface of the adhesive sealing layer can be measured by the following tack test.
(Tack test)
Using the tackiness checker HTC-1 manufactured by Toyo Seiki Co., Ltd., in an atmosphere of 25 ° C and 60% relative humidity, the type of contact is a ring with aluminum R, a contact crimping force of 10 N, and a crimping time of 3 seconds. The tack (adhesive strength) of the adhesive sealing layer can be measured by performing the tack test conducted in.

For the self-sealing tire of the present invention, a sound absorbing material such as a sponge may be placed on the adhesive sealing layer.

Examples of the gas filled in the tire of the present invention include normal or adjusted oxygen partial pressure, and inert gases such as nitrogen, argon, and helium.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Manufacturing of composition for adhesive sealing layer>
Each component in Table 1 below was used in the composition (part by mass) shown in the same table, and these were mixed with a stirrer to prepare a composition for each adhesive sealing layer. The inside of the stirrer was replaced with dried nitrogen gas for mixing.
In the "Rubber component 3" column of Table 1, the numerical value in the upper row represents the amount of the oil-added product of the rubber component 3, and the numerical value in the lower row represents the net amount of SBR in the rubber component 3.

The details of each component shown in Table 1 are as follows.
-Rubber component 1: Natural rubber. PT. KIRANA SAPTA SIR20. Solid under 23 ° C. conditions.
-Rubber component 2: Styrene butadiene rubber. Nippon Zeon Nipol SBR1502. SBR produced by emulsion polymerization. Solid under conditions of weight average molecular weight of 400,000 and 23 ° C.
-Rubber component 3: Styrene butadiene rubber. Nippon Zeon Nipol SBR1723. An oil-extended product in which 37.5 parts by mass of oil is added to 100 parts by mass of the rubber component. SBR produced by emulsion polymerization. Solid under conditions of weight average molecular weight 600,000 and 23 ° C.

-A polyethylene resin having an average of 20 or less trimethoxysilyl groups in a specific polymer 1: 1 molecule. Linkron SL800N manufactured by Mitsubishi Chemical Corporation. A polymer in which a trimethoxysilylethyl group is grafted on linear low density polyethylene (LLDPE) by a radical reaction of vinyltrimethoxysilane. It has a trimethoxysilylethyl group in the side chain. Solid under 23 ° C conditions.
-Specific polymer 2: A (poly) butyl acrylate having an average of two dimethoxysilyl groups in one molecule. NE-4004DD4 manufactured by Soken Chemical Co., Ltd. Viscosity 300 Pa · s, number average molecular weight 16,000, weight average molecular weight 57,000. Liquid under 23 ° C. conditions.

-Plasticizer 1: Paraffin oil. Idemitsu Kosan Diana Process Oil PW-380. Liquid at 23 ° C. Weight average molecular weight 1300
-Plasticizer 2: Naphthenic oil. Idemitsu Kosan Diana Process Oil NM-280. Liquid at 23 ° C. Weight average molecular weight 260
-Plasticizer 3: Aroma oil. Showa Shell Extract No. 4 s. Liquid under 23 ° C conditions. Weight average molecular weight 760

-Condensation catalyst (tin-based): Dioctyl tin dilaurate. Nitto Kasei Co., Ltd. Neostan U810

-Carbon black: Carbon black N660. Tokai Carbon's Seast V.
・ Zinc oxide: Zinc oxide 3 types manufactured by Shodo Chemical Industry Co., Ltd. ・ Stearic acid: Bead stearic acid manufactured by NOF Corporation ・ Water absorbent: Vinyl trimethoxysilane. KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.

<Manufacturing of self-sealing tires>
Each adhesive sealing layer composition produced as described above is sandwiched between two release films in a mold, molded in a 180 ° C. heating press for 3 minutes to form a sheet, cooled, and then molded. The release film was peeled off from one side of the sheet and left in the air for 1 month to prepare a sheet (thickness 3 mm, hereinafter also referred to as “crosslinked sheet”) partially crosslinked with moisture in advance.
Also, vulcanized tires (of the basic structure) with a tire size of 255 / 40R20 were used. The inner liner layer of the tire was made of halogenated butyl rubber.
The crosslinked sheet was evenly attached to the entire inner peripheral surface (inside in the tire radial direction) on the inner liner layer in the tread portion of the tire.
Each tire to which the crosslinked sheet is attached is left under the condition of 23 ° C. and 60% relative humidity for 10 days, and the crosslinked sheet is further crosslinked with the humidity in the air to form an adhesive sealing layer, and a self-sealing tire is formed. (Test piece tire) was manufactured. Table 1 shows the thickness of the adhesive sealing layer of each self-sealing tire (test piece tire).
The tire of Comparative Example 1 does not have an adhesive sealing layer. It is a tire with a basic structure.

<Evaluation>
The following evaluations were performed using each self-sealing tire (test piece tire) manufactured as described above. The results are shown in Table 1.
・ Sealing property of self-sealing tires After assembling each test tire manufactured as described above to a wheel with a rim size of 20 x 8.5J, mounting it on a test vehicle, setting the initial air pressure to 250 kPa, and driving a nail with a diameter of 4 mm into the tread. The air pressure of each test tire was measured after the tire was allowed to stand for 1 hour with the nail removed. The evaluation results are shown in the following five stages.
5: Air pressure after standing still is 240 kPa or more and 250 kPa or less 4: Air pressure after standing is 230 kPa or more and less than 240 kPa 3: Air pressure after standing is 220 kPa or more and less than 230 kPa 2: Air pressure after standing is 200 kPa or more Less than 220 kPa 1: The air pressure after standing still is less than 200 kPa. In the present invention, if the above evaluation result is "2" or more on a 5-point scale, the sealing property is excellent. When the five-grade evaluation of the above evaluation result is "2" or more, the higher the evaluation, the better the sealing property.
When the above evaluation result was "1" on a 5-point scale, it was evaluated that the sealing property was poor.

-Flow resistance of the adhesive sealing layer in self-sealing tires Each test tire manufactured as described above is assembled on a wheel with a rim size of 20 x 8.5J and mounted on a test vehicle, with an initial air pressure of 250 kPa and a load of 8. A running test was conducted in which the running speed was set to 5 kN and the running speed was 80 km / h for 24 hours. The state of the adhesive sealing layer after the running test was visually confirmed.
When no flow was observed in the adhesive sealing layer after the running test, it was evaluated as having excellent flow resistance and marked with "○".
When the adhesive sealing layer after the running test flowed, it was evaluated as having poor flow resistance and marked with "x".

As is clear from the results shown in Table 1, Comparative Example 1 without the adhesive sealing layer had poor sealing properties.
Comparative Example 2 in which the composition for the adhesive sealing layer did not contain a specific polymer had poor flow resistance.
In Comparative Example 3 in which the composition for the adhesive sealing layer did not contain a rubber component, the sealing property was poor.

On the other hand, the self-sealing tire of the present invention has excellent sealing properties and flow resistance for the adhesive sealing layer.

1 Tread part 2 Side wall part 3 Bead part 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 8 Belt reinforcement layer 9 Inner liner layer 10 Adhesive sealing layer 20 Self-sealing tire CL Tire equator

Claims (9)

The adhesive sealing layer has an adhesive sealing layer on the inner surface of the tire, and the adhesive sealing layer is
With the rubber component,
A polymer having more than one hydrolyzable and condensable silicon group in one molecule on average,
With a plasticizer,
A self-sealing tire formed by a composition for an adhesive sealing layer containing a condensation catalyst. The self-sealing tire according to claim 1, wherein the composition for an adhesive sealing layer is hydrolyzed, condensed and crosslinked by moisture. The composition according to claim 1 or 2, wherein the composition for an adhesive sealing layer is partially crosslinked with moisture in advance, and then the partially crosslinked composition for an adhesive sealing layer is placed on the inner surface of the tire and further crosslinked. Self-sealing tire. The self-sealing tire according to any one of claims 1 to 3, wherein the polymer contains a polyolefin having a trialkoxysilyl group in the side chain. The self-sealing tire according to any one of claims 1 to 4, wherein the polymer contains a (meth) acrylic polymer having more than one hydrolyzable condensable silicon group in one molecule on average. The self-sealing tire according to any one of claims 1 to 5, wherein the rubber component comprises at least one selected from the group consisting of natural rubber, styrene-butadiene rubber, butadiene rubber and isoprene rubber. The self-sealing tire according to any one of claims 1 to 6, wherein the plasticizer contains at least one selected from the group consisting of polybutene, process oils and ester-based plasticizers. The self-sealing tire according to any one of claims 1 to 7, wherein the content of the polymer is 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component. The self-sealing tire according to any one of claims 1 to 8, wherein the content of the plasticizer is 50 to 400 parts by mass with respect to 100 parts by mass of the rubber component.

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