JP2008024219A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire using a laminate with a superior exfoliation resistance obtained by jointing and integrating a thermoplastic film layer and a rubber elastic layer via an adhesive layer containing an adhesive composition and without failures such as bubbles in manufature derived from the adhesive after heating/vulcanization, when a tire using a single layer or a multi-layer thermoplastic film as an inner liner layer capable of making a gauge thin is manufactured. <P>SOLUTION: This tire uses (A) a single layer, in which soft resin is dispersed in matrix resin, or a multi-layer thermoplastic resin film layer containing a layer, in which soft resin is dispersed in matrix resin, as an inner liner layer. A coating liquid containing an adhesive composition is applied/dried on the layer (A) and/or a rubber elastic layer (B). After the adhesive layer (C) is formed, the layers (A) and (B) are adhered via the adhesive layer (C). At that time, a volatile component when the laminate comprising the layer (A) and/or the layer (B) containing the adhesive layer (C) is further treated at 120°C for 2 hours is 10 mass% or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tire using a single layer or multilayer thermoplastic film as an inner liner layer capable of reducing gauge, and comprising an adhesive layer containing an adhesive composition comprising the thermoplastic film layer and a rubber elastic layer. The present invention relates to a pneumatic tire that has been joined and integrated to eliminate manufacturing defects caused by the adhesive after heating and vulcanization.

Conventionally, an inner liner layer mainly composed of a low gas permeable butyl rubber such as butyl rubber or halogenated butyl rubber has been provided on the inner surface of a pneumatic tire in order to prevent air leakage and keep the tire air pressure constant. Yes. However, if the content of these butyl rubbers is increased, the strength of the unvulcanized rubber will decrease, and it will easily cause rubber breakage and sheet holes. Sometimes the inner cord tends to be exposed.
Therefore, the blending amount of the butyl rubber is limited by itself, and when using a rubber composition blended with the butyl rubber, the thickness of the inner liner layer needs to be around 1 mm from the viewpoint of air barrier properties. . Therefore, the weight of the inner liner layer in the tire is about 5%, which has been an obstacle for reducing the weight of the tire and improving the fuel efficiency of the automobile.
Therefore, in accordance with social demands for energy saving in recent years, a method for reducing the thickness of the inner liner layer has been proposed for the purpose of reducing the weight of automobile tires. For example, a method of using a nylon film layer or a vinylidene chloride layer as an inner liner layer instead of a conventional butyl rubber is disclosed (for example, see Patent Document 1 and Patent Document 2). In addition, it is disclosed that a film of a composition comprising a blend of a thermoplastic resin such as a polyamide-based resin or a polyester-based resin and an elastomer is used for the inner liner layer (see, for example, Patent Document 3).

However, the methods using these films, even if the weight of the tire can be reduced to some extent, since the matrix agent is a crystalline resin material, crack resistance and resistance particularly when used at a low temperature of 5 ° C. or less. There is a drawback that bending fatigue is inferior to that of a butyl rubber compounded composition layer that is usually used, and tire manufacture is also complicated.
On the other hand, an ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is known to have excellent gas barrier properties. EVOH has an air permeation amount of 1/100 or less of the inner liner rubber composition containing butyl rubber, so that the internal pressure retention can be greatly improved even with a thickness of 50 μm or less. It is possible to reduce the weight. Therefore, it can be said that it is effective to use EVOH for the tire inner liner in order to improve the air permeability of the pneumatic tire. For example, a pneumatic tire having a tire inner liner made of EVOH is disclosed (see, for example, Patent Document 4).

However, when this EVOH is used as an inner liner, the effect of improving the internal pressure retention is great, but because the elastic modulus is significantly higher than that of rubber used in normal tires, it will break or crack due to deformation during bending. It sometimes occurred. For this reason, when an inner liner made of EVOH is used, the internal pressure retention before use of the tire is greatly improved, but the internal pressure retention of the tire after use subjected to bending deformation during rolling of the tire is higher than that before use. There was a problem that it may decrease.
In order to solve this problem, for example, it comprises 60 to 99% by weight of an ethylene-vinyl alcohol copolymer having an ethylene content of 20 to 70 mol%, a saponification degree of 85% or more, and 1 to 40% by weight of a hydrophobic plasticizer. Although an inner liner for a tire inner surface using a resin composition is disclosed (see, for example, Patent Document 5), the bending resistance is not always satisfactory.
Accordingly, there has been a demand for the development of an inner liner that has a high degree of bending resistance and can be made thinner while maintaining gas barrier properties.
As such an inner liner, for example, a laminated body in which a rubber-like elastic film or sheet having excellent bending resistance and a resin film having good gas barrier properties are joined and integrated via an adhesive layer can be considered. In this case, workability in the production process of the laminate is required, there is no problem due to the generation of bubbles or the like derived from the adhesive after vulcanization of the tire, and excellent peeling resistance is required.

Japanese Patent Laid-Open No. 7-40702 JP-A-7-81306 JP-A-10-26407 JP-A-6-40207 JP 2002-52904 A

  Under such circumstances, the present invention bonds the thermoplastic film layer and the rubber elastic layer when manufacturing a tire using a single-layer or multilayer thermoplastic film as an inner liner layer that can be made thinner. It is a laminated body that is joined and integrated through an adhesive layer containing an adhesive composition, and has no defects such as generation of bubbles derived from the adhesive after heating and vulcanization, and has excellent peeling resistance Another object of the present invention is to provide a pneumatic tire using the laminate.

As a result of intensive studies to achieve the above object, the present inventors applied and dried an adhesive containing a specific adhesive composition on the thermoplastic resin film layer and / or the rubber-like elastic layer. The resulting laminate comprising a thermoplastic resin film layer containing an adhesive layer and / or a rubber-like elastic body containing an adhesive layer is further treated at a specific temperature and time, and the value of the generated volatile component is a specific value. The purpose can be achieved by joining, integrating, heating and vulcanizing the thermoplastic resin film layer and the rubber-like elastic body layer via the adhesive layer dried under the drying conditions that are below the specified value. I found. The present invention has been completed based on such findings.
That is, the present invention
(1) A tire using a multilayer thermoplastic resin film layer including (A) a single layer in which a flexible resin is dispersed in a matrix resin or a layer in which a flexible resin is dispersed in a matrix resin as an inner liner layer. Then, the coating liquid containing the adhesive composition is applied to the layer (A) and / or (B) the rubber elastic layer and dried (C) to form the adhesive layer, and then the (A) layer and the (B When the layer is bonded to the layer (C) via the adhesive layer, the laminate comprising the (A) layer and / or the (B) layer including the (C) adhesive layer is further treated at 120 ° C. for 2 hours. Pneumatic tire characterized in that the volatile component at the time is 10% by mass or less,
(2) (C) The adhesive composition constituting the adhesive layer comprises (a) a rubber component and 100 parts by mass thereof, (b) poly-p-dinitrosobenzene, maleimide as a crosslinking agent and a crosslinking aid. The pneumatic tire according to (1) above, containing at least 0.1 part by mass of at least one derivative,
(3) The pneumatic tire according to claim 14, wherein the maleimide derivative of the component (b) is 1,4-phenylene dimaleimide.
(4) The pneumatic tire according to any one of the above (1) to (3), wherein the adhesive composition contains 10% by mass or more of chlorosulfonated polyethylene as a rubber component (a),
(5) The pneumatic tire according to any one of the above (1) to (4), wherein the adhesive composition further includes (c) 2 to 50 parts by mass of a filler,
(6) The pneumatic tire according to (5), wherein the adhesive composition includes (c) carbon black as a filler,
(7) In the adhesive composition, (a) the rubber component includes 50 parts by mass or more of butyl rubber and / or halogenated butyl rubber, the pneumatic tire according to any one of (1) to (6) above,
(8) The pneumatic tire according to any one of (1) to (7), wherein the adhesive composition further includes (d) 0.1 part by mass or more of a rubber vulcanization accelerator,
(9) The pneumatic tire according to (8), wherein (d) the rubber vulcanization accelerator is a thiuram-based and / or substituted dithiocarbamate-based vulcanization accelerator,
(10) The pneumatic tire according to any one of (1) to (9), wherein the adhesive composition further includes (e) 0.1 part by weight or more of at least one of a resin and a low molecular weight polymer,
(11) The above (10), wherein the resin in component (e) is at least one selected from C5 resins, phenol resins, terpene resins, modified terpene resins, hydrogenated terpene resins, and rosin resins. Pneumatic tires,
(12) The pneumatic tire according to (11), wherein the resin is a phenol resin.
(13) The pneumatic tire according to (10), wherein the weight average molecular weight of the low molecular weight polymer in component (e) is 1,000 to 100,000 in terms of polystyrene,
(14) The pneumatic tire according to (13), wherein the weight average molecular weight of the low molecular weight polymer in the component (e) is 1,000 to 50,000 in terms of polystyrene,
(15) The pneumatic tire according to any one of (10) to (14), wherein the low molecular weight polymer in component (e) is a polymer having a double bond in the molecule.
(16) The pneumatic tire according to any one of the above (10) to (15), wherein the low molecular weight polymer in the component (e) is a polymer containing a styrene unit.
(17) The pneumatic tire according to (16), wherein the low molecular weight polymer in component (e) is a styrene-butadiene copolymer,
(18) With respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 50 mol%, the thermoplastic resin constituting the matrix in which the flexible resin is dispersed in (A) the matrix resin, The pneumatic tire according to any one of the above (1) to (17), comprising a layer comprising a modified ethylene-vinyl alcohol copolymer obtained by reacting 1 to 50 parts by weight of an epoxy compound;
(19) The flexible resin has a functional group that reacts with a hydroxyl group, Young's modulus is 500 MPa or less, and the content of the flexible resin is 10 to 30% by mass with respect to 100 parts by mass of the modified ethylene-vinyl alcohol copolymer. The pneumatic tire according to any one of claims 1 to 18, comprising a resin composition dispersed in the copolymer with an average particle size of 2 µm or less.
(20) (A) A thermoplastic urethane elastomer as a surface layer of a multilayer thermoplastic resin film layer including a single layer in which a flexible resin is dispersed in a matrix resin or a layer in which a flexible resin is dispersed in a matrix resin The pneumatic tire according to any one of (1) to (19) above,
(21) The pneumatic tire according to any one of (1) to (20) above, wherein butyl rubber or halogenated butyl rubber is used for the (B) rubber-like elastic layer.
(22) The pneumatic tire according to any one of (1) to (20), wherein a diene elastomer is used for the (B) rubber-like elastic layer.
(23) After coating / drying a coating liquid composed of an adhesive composition containing an organic solvent on a rubber-like elastic film or sheet surface, a resin film is pasted thereon and heated / vulcanized. The pneumatic tire according to any one of (1) to (22), and (24) the pneumatic tire according to (23), wherein the heating / vulcanizing temperature is 100 ° C. or higher.
Is to provide.

  According to the present invention, a tire using a single-layer or multilayer thermoplastic film layer as an inner liner layer capable of thinning gauge, wherein the thermoplastic resin film layer and the rubber elastic body layer are combined with an adhesive composition. The laminated body joined and integrated through the adhesive layer including the above laminated body having no defects such as production of bubbles derived from the adhesive after heating and vulcanization, and having excellent peeling resistance. The used pneumatic tire can be provided.

  The pneumatic tire of the present invention uses a multilayer thermoplastic resin film layer including (A) a single layer in which a flexible resin is dispersed in a matrix or a layer in which a flexible resin is dispersed in a matrix as an inner liner layer. A coating liquid containing an adhesive composition, which is a tire, is applied to the layer (A) and / or (B) the rubber elastic layer and dried (C) to form an adhesive layer, and then the layer (A) In adhering the (B) layer via the (C) adhesive layer, a laminate comprising the (A) layer and / or the (B) layer including the (C) adhesive layer is further added at 120 ° C. The volatile component at the time of the time treatment is 10% by mass or less.

Normally, when a plastic film is used as the inner liner layer, when the surface layer of a single layer or multilayer thermoplastic film is directly bonded to the adjacent rubber-like elastic layer, the adhesive strength between the two is low, and the required characteristics of the tire In order to ensure the above, it is necessary to integrate them through an adhesive layer.
The adhesive according to the present invention is used as a coating liquid composed of an adhesive composition containing a volatile component such as an organic solvent, and the coating liquid is applied and dried on the (A) layer and / or (B) surface. The volatile component generated when the laminate comprising the (A) layer and / or the (B) layer including the (C) adhesive layer is further treated at 120 ° C. for 2 hours is 10% by mass or less. is required. More preferably, it is 5 mass% or less. (C) The adhesive layer that has undergone the drying process is further treated at 120 ° C. for 2 hours to remove volatile components mainly derived from the solvent remaining in the adhesive layer, and confirm the amount of volatile components. it can.
An unvulcanized tire in which the (A) layer and the (B) layer are joined and integrated through the (C) layer using the (C) adhesive layer containing volatile components exceeding 10% by mass as it is. When the vulcanization treatment is performed, the volatile component remaining in the layer (C) volatilizes during the manufacture of the tire and may accumulate as bubbles locally in the tire, which may cause a malfunction in the tire. Such a phenomenon is particularly likely to occur when the (A) layer composed of a thermoplastic resin film layer is used as the inner liner layer, and causes problems as compared with the conventional one using a butyl rubber-based inner liner. Probability is high.
When the volatile component remaining in the (C) layer is 10% by mass or less, a tire having the above-described problems and having a high peel resistance can be obtained as the inner liner laminate.

The thermoplastic resin constituting the matrix in which the flexible resin is dispersed in the matrix resin constituting the layer (A) in the pneumatic tire of the present invention has good gas barrier properties and appropriate mechanical strength. Any resin film can be used without particular limitation. Examples of such a resin film material include polyamide resins, polyvinylidene chloride resins, polyester resins, ethylene-vinyl alcohol copolymer resins, and thermoplastic urethane elastomers. These may be used individually by 1 type, and may be used in combination of 2 or more types. The resin film produced using these materials may be a single layer film or a multilayer film having two or more layers.
Among the materials, ethylene-vinyl alcohol copolymer-based resin is a preferable material because it has an extremely low air permeation amount and excellent gas barrier properties. The thermoplastic urethane-based elastomer is excellent in water resistance and adhesiveness to rubber, and is preferably used by being disposed in the outer layer portion in a multilayer film.

The ethylene-vinyl alcohol copolymer-based resin is preferably a modified ethylene-vinyl alcohol copolymer obtained by reacting an epoxy compound with an ethylene-vinyl alcohol copolymer. By modifying in this way, the elastic modulus of the unmodified ethylene-vinyl alcohol copolymer can be greatly reduced, and the breakability during bending and the degree of occurrence of cracks can be improved.
In the ethylene-vinyl alcohol copolymer used for this modification treatment, the ethylene unit content is preferably 25 to 50 mol%. From the viewpoint of obtaining good flex resistance and fatigue resistance, the ethylene unit content is more preferably 30 mol% or more, and even more preferably 35 mol% or more. From the viewpoint of gas barrier properties, the ethylene unit content is more preferably 48 mol% or less, and even more preferably 45 mol% or less. When the ethylene unit content is less than 25 mol%, flex resistance and fatigue resistance may be deteriorated, and melt moldability may be deteriorated. Moreover, when it exceeds 50 mol%, gas barrier property may be insufficient.
Further, the saponification degree of the ethylene-vinyl alcohol copolymer is preferably 90 mol% or more, more preferably 95 mol% or more, further preferably 98 mol% or more, and optimally 99 mol%. That's it. If the degree of saponification is less than 90 mol%, the gas barrier properties and the thermal stability during production of the laminate may be insufficient.

The preferred melt flow rate (MFR) (under 190 ° C. and 21.18 N load) of the ethylene-vinyl alcohol copolymer used in the modification treatment is 0.1 to 30 g / 10 minutes, and more preferably 0.3. ~ 25 g / 10 min. However, when the melting point of the ethylene-vinyl alcohol copolymer is around 190 ° C. or exceeds 190 ° C., it is measured under a load of 21.18 N at a plurality of temperatures equal to or higher than the melting point. The logarithm of MFR is plotted on the vertical axis and expressed as a value extrapolated to 190 ° C.
In the modification treatment, the epoxy compound is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, and further preferably 5 to 35 parts by mass with respect to 100 parts by mass of the unmodified ethylene-vinyl alcohol copolymer. It can be carried out by reacting parts. In this case, it is advantageous to carry out the reaction in a solution using a suitable solvent.

  In the modification treatment method by solution reaction, a modified ethylene-vinyl alcohol copolymer is obtained by reacting an epoxy compound with an ethylene-vinyl alcohol copolymer solution in the presence of an acid catalyst or an alkali catalyst. The reaction solvent is preferably a polar aprotic solvent which is a good solvent for an ethylene-vinyl alcohol copolymer such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone. Reaction catalysts include acid catalysts such as p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, sulfuric acid and boron trifluoride, and alkali catalysts such as sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium methoxide. Is mentioned. Of these, it is preferable to use an acid catalyst. As a catalyst amount, about 0.0001-10 mass parts is suitable with respect to 100 mass parts of ethylene-vinyl alcohol copolymers. The modified ethylene-vinyl alcohol copolymer can also be produced by dissolving an ethylene-vinyl alcohol copolymer and an epoxy compound in a reaction solvent and performing a heat treatment.

The epoxy compound used for the modification treatment is not particularly limited, but is preferably a monovalent epoxy compound. When the epoxy compound is divalent or higher, a cross-linking reaction with the ethylene-vinyl alcohol copolymer may occur, and the quality of the laminate may be deteriorated due to the generation of gels and blisters. From the viewpoint of ease of production of the modified ethylene-vinyl alcohol copolymer, gas barrier properties, flex resistance, and fatigue resistance, preferred monovalent epoxy compounds include glycidol and epoxy propane.
The melt flow rate (MFR) (under 190 ° C. and 21.18 N load) of the modified ethylene-vinyl alcohol copolymer used in the present invention is not particularly limited, but has good gas barrier properties, flex resistance and fatigue resistance. From the viewpoint of obtaining, it is preferably 0.1 to 30 g / 10 minutes, more preferably 0.3 to 25 g / 10 minutes, and further preferably 0.5 to 20 g / 10 minutes. However, when the melting point of the modified EVOH is around 190 ° C or exceeds 190 ° C, it is measured under a load of 21.18 N at a plurality of temperatures above the melting point. Plotted on the axis and expressed as a value extrapolated to 190 ° C.

The oxygen permeation amount at 20 ° C. and 65 RH% of the film layer made of the modified ethylene-vinyl alcohol copolymer is preferably 3 × 10 ⁻¹⁵ cm ³ · cm ² · sec · Pa or less, It is more preferably 7 × 10 ⁻¹⁶ cm ³ · cm ² · sec · Pa or less, and further preferably 3 × 10 ⁻¹⁶ cm ³ · cm ² · sec · Pa or less.

As the thermoplastic film constituting the (A) layer in the pneumatic tire of the present invention, it is necessary to disperse a flexible resin in a matrix made of a thermoplastic resin. The flexible resin preferably has a functional group that reacts with a hydroxyl group and has a Young's modulus of 500 MPa or less. The content of the flexible resin in the thermoplastic resin matrix is preferably 10 to 30% by mass with respect to 100 parts by mass of the thermoplastic resin, and the average particle size is preferably 2 μm or less as the dispersion state.
The thermoplastic resin in which the flexible resin is dispersed is a modified ethylene-vinyl alcohol obtained by reacting 1 to 50 parts by mass of an epoxy compound with respect to 100 parts by mass of an ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 50 mol%. A copolymer is preferred. The modified ethylene-vinyl alcohol copolymer has a lower elastic modulus than a normal ethylene-vinyl alcohol copolymer, and further has a functional group that reacts with a hydroxyl group, and a flexible resin that satisfies the above physical properties is dispersed. The elastic modulus can be further reduced. Therefore, the resin composition in which a flexible resin is dispersed in a matrix composed of the modified ethylene-vinyl alcohol copolymer has a significantly reduced elastic modulus, high rupture resistance when bent, and cracks are also generated. It is hard to do.

The flexible resin dispersed in the matrix made of the modified ethylene-vinyl alcohol copolymer has a functional group that reacts with a hydroxyl group, has a Young's modulus of 500 MPa or less, and has a functional group that reacts with a hydroxyl group. The flexible resin is uniformly dispersed in the vinyl alcohol copolymer. Here, examples of the functional group that reacts with a hydroxyl group include a maleic anhydride residue, a hydroxyl group, a carboxyl group, and an amino group.
Specific examples of the flexible resin having a functional group that reacts with a hydroxyl group include maleic anhydride-modified hydrogenated styrene-ethylene-butadiene-styrene block copolymer, maleic anhydride-modified ultra-low density polyethylene, and the like. Further, when the Young's modulus of the flexible resin is 500 MPa or less, the elastic modulus of the resin composition can be lowered, and as a result, the bending resistance can be improved.

Moreover, it is preferable that the content rate of the flexible resin in the said resin composition is the range of 10-30 mass%. By making the content rate of a flexible resin into the said range, the fall of gas barrier property can be suppressed and bending resistance can be improved.
Furthermore, it is preferable that the average particle diameter in the state disperse | distributed to the modified ethylene-vinyl alcohol copolymer of the said flexible resin is 2 micrometers or less. If the average particle size exceeds 2 μm, the bending resistance of the layer made of the resin composition may not be sufficiently improved, and the gas barrier property may be deteriorated and the internal pressure retention property of the tire may be deteriorated.

  The resin composition can be prepared by kneading the modified ethylene-vinyl alcohol copolymer and the flexible resin (D). The resin composition is preferably in the form of a film at the time of producing the inner liner, and the layer made of the resin composition is preferably 150 to 350 by melt molding, preferably extrusion molding such as T-die method or inflation method. Used as a molded inner liner for films and sheets at a melting temperature of 270 ° C.

In the pneumatic tire of the present invention, the thermoplastic urethane elastomer (hereinafter sometimes abbreviated as TPU) of the thermoplastic film constituting the layer (A) is a urethane group (—NH—COO) in the molecule. -) Is an elastomer having (1) polyol (long-chain diol), (2) diisocyanate, and (3) short-chain diol. The polyol and the short chain diol undergo an addition reaction with diisocyanate to produce a linear polyurethane. Among these, the polyol becomes a flexible portion (soft segment) of the elastomer, and the diisocyanate and the short-chain diol become a hard portion (hard segment). The properties of TPU depend on the properties of raw materials, the polymerization conditions, and the blending ratio, and among these, the type of polyol greatly affects the properties of TPU. Many of the basic properties are determined by the type of long chain diol, but the hardness is adjusted by the proportion of hard segments.
The types are (i) caprolactone type (polylactone ester polyol obtained by ring-opening caprolactone), (b) adipic acid type (= adipate type) <adipic acid ester polyol of adipic acid and glycol>, (ha ) PTMG (polytetramethylene glycol) type (= ether type) <polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran>.

In the present invention, the method for molding the resin film constituting the layer (A) is not particularly limited, and in the case of a single layer film, a conventionally known method, for example, a solution casting method, a melt extrusion method, a calendering method, or the like is adopted. Among these methods, a melt extrusion method such as a T-die method or inflation is preferable. In the case of a multilayer film, a laminating method by coextrusion is preferably used.
The thickness of the (A) resin film layer in the present invention is preferably 200 μm or less from the viewpoint of reducing the gauge when using a laminate of thermoplastic resin films as an inner liner. Moreover, when too thin, there exists a possibility that the effect which joined the (A) layer to the (B) layer may not fully be exhibited. Therefore, the lower limit of the thickness of the layer (A) is about 1 μm, a more preferable thickness is 10 to 150 μm, and a further preferable thickness is 20 to 100 μm.
In the present invention, the resin film layer constituting the layer (A) preferably includes a thermoplastic urethane-based elastomer layer, and particularly includes a thermoplastic urethane-based elastomer layer and a modified resin in which the flexible resin is dispersed. A layer composed of a multilayer film including one or more ethylene-vinyl alcohol copolymer layers is preferred.

A specific example of such a multilayer film is a multilayer film having a three-layer structure in which a thermoplastic urethane elastomer film is laminated on both sides of the modified ethylene-vinyl alcohol copolymer film in which the flexible resin is dispersed. Can be mentioned.
In order to improve the adhesiveness with the adhesive layer provided on the (A) layer, the resin film constituting the layer (A) is optionally formed on at least the surface of the adhesive layer by an oxidation method or an unevenness method. Surface treatment can be applied. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like. Treatment methods and the like. These surface treatment methods are appropriately selected depending on the type of the base film, but generally, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.

In the pneumatic tire of the present invention, preferred examples of the rubber-like elastic body constituting the layer (B) include butyl rubber and diene rubber. Examples of the diene rubber include natural rubber, isoprene synthetic rubber (IR), cis 1,4-polybutadiene (BR), syndiotactic-1,2-polybutadiene (1,2BR), and styrene-butadiene rubber (SBR). , Acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR) and the like. Of these, natural rubber and butadiene rubber are preferred.
From the viewpoint of gas barrier properties, it is preferable to use butyl rubber as the rubber-like elastic body. Examples of the butyl rubber include butyl rubber and / or halogenated butyl rubber. Among the butyl rubbers, the vulcanization speed is fast, heat resistance, adhesiveness, and compatibility with other unsaturated rubbers. Halogenated butyl rubber is preferred from the standpoint of superiority. Examples of the halogenated butyl rubber include chlorinated butyl rubber, brominated butyl rubber, and modified rubber thereof. For example, there is “Enjay Butyl HT10-66” (trademark, manufactured by Enjay Chemical Co., Ltd.) as a chlorinated butyl rubber, and “bromobutyl 2255” (trademark, manufactured by Exxon Corp.) as a brominated butyl rubber. Further, a chlorinated or brominated modified copolymer of a copolymer of isomonoolefin and paramethylstyrene can be used as the modified rubber, and is available as, for example, “Expro 50” (trademark, manufactured by Exxon). .

  In addition, from the viewpoint of suppressing the extension of the crack after the occurrence of cracks in the rubber-like elastic layer, it is preferable to use a composition containing butyl rubber and diene rubber as the rubber-like elastic body. A preferable content of the butyl rubber in the rubber component in the rubber-like elastic body is 70 to 100% by mass from the viewpoint of air permeation resistance, and 0 to 50% by mass, preferably 0 in the rubber component. The diene rubber can be contained at a ratio of ˜30 mass%. By using such a composition as a rubber-like elastic body, oxygen permeation can be satisfactorily suppressed even when minute cracks are generated in the rubber-like elastic body layer.

The rubber-like elastic body can contain an inorganic filler in addition to the rubber component in order to improve air permeation resistance, low-temperature crack resistance, bending fatigue resistance, and the like. As the inorganic filler, a layered or plate-like one is preferable, and examples thereof include a hydrous composite of kaolin, clay, mica, feldspar, silica and alumina. The content of the inorganic filler is usually about 10 to 180 parts by mass, preferably 20 to 120 parts by mass per 100 parts by mass of the rubber component.
Further, for the purpose of improving the strength of the unvulcanized rubber, 0 to 50 parts by mass, preferably 10 to 50 parts by mass of carbon black can be further contained per 100 parts by mass of the rubber component.
The type of the carbon black is not particularly limited, and any one of those conventionally used as a reinforcing filler for rubber can be appropriately selected and used. For example, FEF, SRF, HAF, ISAF, SAF, GPF etc. are mentioned.
In the present invention, the total content of the inorganic filler and carbon black is from the balance of air permeation resistance, flex fatigue resistance, low temperature crack resistance, workability, and the like per 100 parts by mass of the rubber component. A range of 30 to 200 parts by mass is preferable, and a range of 50 to 140 parts by mass is particularly preferable.

In the rubbery elastic body, in order to improve the dispersibility of the inorganic filler and carbon black in the rubber component and to improve the desired physical properties, the dispersion improver is further added in an amount of 0 to 5 mass per 100 parts by mass of the rubber component. Part can be contained. Examples of the dispersion improver include a silane coupling agent, dimethyl stearylamine, and triethanolamine. These may be used individually by 1 type, and may be used in combination of 2 or more types.
Further, in the rubber-like elastic body, when the carbon black is blended, the ratio of naphthenic oil or paraffinic oil is 1 part by mass or more, particularly 3 to 20 parts by mass, per 100 parts by mass of the rubber component. It is preferable to contain. Here, naphthenic oil preferably has% C _N by ring analysis of 30 or more, paraffinic oil% C _P is preferably of 60 or more.

The rubbery elastic body can contain organic short fibers as desired. By including this organic short fiber, when the laminate according to the present invention is used as an inner liner, it is possible to suppress the inner surface cord exposure that occurs when the inner liner is thinned to produce a tire. The organic short fibers preferably have an average diameter of 1 to 100 μm and an average length of about 0.1 to 0.5 mm. This organic short fiber may be blended as FRR (complex of short fiber and unvulcanized rubber).
The content of such organic short fibers is preferably 0.3 to 15 parts by mass per 100 parts by mass of the rubber component. The material of the organic short fiber is not particularly limited, and examples thereof include polyamides such as nylon 6 and ny 66, syndiotactic-1,2-polybutadiene, isotactic polypropylene, polyethylene, and the like. Polyamide is preferred.

Further, in order to increase the modulus of the organic short fiber compound rubber, an adhesion improver between rubber and fiber such as hexamethylenetetramine and resorcin can be further compounded.
In the rubbery elastic body, in addition to the above compounding agents, various chemicals usually used in the rubber industry, such as vulcanizing agents, vulcanization accelerators, anti-aging agents, as long as the object of the present invention is not impaired. A scorch inhibitor, zinc white, stearic acid, etc. can be blended.
In the present invention, the rubber-like elastic body constituting the layer (B) is obtained by extruding a rubber composition containing each of the above components into a film or a sheet at an unvulcanized stage by a conventionally known method. Can be obtained.
The thickness of the rubber-like elastic layer (B) in the present invention is usually 200 μm or more. The upper limit is appropriately determined depending on the tire size in consideration of the reduction in gauge when used as an inner liner.

  (B) When the laminate according to the present invention provided with a rubber-like elastic layer is applied to an inner liner of a tire, the above-mentioned (A) resin film layer is used with a thin gauge of 200 μm or less, so that it is resistant to bending. And fatigue resistance are improved, and breakage and cracks are less likely to occur due to bending deformation during rolling of the tire. Even if it breaks, the (A) resin film layer has a very good adhesion to the (B) rubber-like elastic layer through the adhesive layer (C), which will be described later, and is difficult to peel off. Since it is difficult to extend, large breakage and cracks do not occur. Even when it occurs, (B) the rubber elastic layer supplements the gas barrier properties of the fracture and cracks generated in the (A) resin film layer, so that good internal pressure can be maintained even after use of the tire.

In the laminate according to the present invention, (C) the adhesive composition constituting the adhesive layer includes (a) a rubber component and 100 parts by mass of (b) a poly-p as a crosslinking agent and a crosslinking aid. -Dinitrosobenzene, a composition containing at least 0.1 part by mass of at least one of maleimide derivatives having two or more reactive sites in the molecule is used.
Examples of the maleimide derivative include 1,4-phenylene dimaleimide, 1,3-bis (citraconimidomethyl) benzene, and among these, 1,4-phenylene dimaleimide is preferable.
In the adhesive composition, (a) the rubber component is not particularly limited, and (A) a resin film layer and (B) a rubber-like elastic body layer, and a combination thereof and excellent tackiness and peeling resistance, respectively. In general, it is preferable to use 50% by mass or more of butyl rubber and / or halogenated butyl rubber or diene rubber.
The butyl rubber and / or halogenated butyl rubber and diene rubber are as illustrated in the description of the rubber-like elastic body constituting the layer (B).
The component (a) preferably contains 70 to 100% by mass of a halogenated butyl rubber from the viewpoints of workability of the adhesive layer and peeling resistance.

Furthermore, it is preferable to contain 10% by mass or more of chlorosulfonated polyethylene as desired as the component (a). The chlorosulfonated polyethylene (hereinafter sometimes abbreviated as CSM) is a synthetic rubber having a saturated structure containing no double bond, which is produced by chlorinating and chlorosulfonated polyethylene using chlorine and sulfurous acid gas. Excellent stability such as weather resistance, ozone resistance and heat resistance. CSM is commercially available from DuPont under the trade name “Hypalon”. From the viewpoints of improving the peel resistance of the adhesive layer, heat resistance, etc., those containing 10 to 40% by mass of CSM are preferable.
In the present invention, from the viewpoint of peeling resistance, it is particularly preferable to contain 70% by mass or more of halogenated butyl rubber, 10% by mass or more of chlorosulfonated polyethylene and 5% by mass or more of natural rubber and / or isoprene rubber.

In the adhesive composition, in order to improve the peel resistance after heat treatment, (b) at least one of poly-p-dinitrosobenzene and 1,4-phenylene dimaleimide is used as a crosslinking agent and a crosslinking aid. Is preferably blended in an amount of 0.1 parts by mass or more.
Poly-p-dinitrosobenzene is an effective cross-linking agent for rubbers with few double bonds such as halogenated butyl rubber. Unvulcanized compound by adding poly-p-dinitrosobenzene and heat treatment It can prevent cold flow of products, improve extrusion properties, physical properties of vulcanizates, and adjust plasticity.
In addition, vulcanization using 1,4-phenylene dimaleimide produces a carbon-carbon covalent bond and improves heat resistance and aging resistance. In particular, it is an effective crosslinking agent for chlorosulfonated polyethylene rubber.
The blending amount of the component (b) with respect to the adhesive composition is preferably 0.1 parts by mass with respect to 100 parts by mass of the rubber component of the adhesive composition.

As the filler of component (c) in the adhesive composition, an inorganic filler and / or carbon black can be used. Examples of the inorganic filler include silica by a wet method (hereinafter referred to as wet silica), aluminum hydroxide, aluminum oxide, magnesium oxide, montmorillonite, mica, smectite, organic montmorillonite, organic mica, and organic smectite. be able to. These may be used individually by 1 type, and may be used in combination of 2 or more types.
On the other hand, about carbon black, it is as having illustrated in description of the rubber-like elastic body which comprises the above-mentioned (B) layer.
In the adhesive composition, the content of the filler that is the component (c) is 2 to 50 masses per 100 parts by mass of the rubber component that is the component (a) in terms of tackiness and peeling resistance. Parts, preferably in the range of 5 to 35 parts by weight.

  Further, as a commercially available adhesive composition containing (a) a chlorosulfonated polyethylene as a rubber component, (b) a crosslinking agent and a crosslinking aid, and (c) a filler as a component contained in the adhesive composition, for example, Chemlock 6250 (manufactured by Road Corporation) may be mentioned. This Chemlock 6250 can also be used as a mixture of components (a), (b) and (c) of the adhesive composition.

  In the adhesive composition, as a component (d), by including 0.1 part by mass or more of a vulcanization accelerator per 100 parts by mass of the rubber component, the obtained laminate can exhibit a desired peeling resistance. it can. There are no particular restrictions on the vulcanization accelerator, and examples include at least one selected from thiuram, substituted dithiocarbamate, guanidine, thiazole, sulfenamide, thiourea, xanthate, and the like. Can do. Of these, thiuram-based and / or substituted dithiocarbamate-based vulcanization accelerators are preferred. Although there is no restriction | limiting in particular about the upper limit of content of the said vulcanization accelerator, Usually, it is about 5 mass parts. The preferable content of the vulcanization accelerator is in the range of 0.3 to 3 parts by mass.

By including 0.1 part by mass or more of a thiuram-based and / or substituted dithiocarbamate-based vulcanization accelerator, the obtained laminate can exhibit a desired peeling resistance. Although there is no restriction | limiting in particular about the upper limit of content of the said vulcanization accelerator, Usually, it is about 5 mass parts. The preferable content of the vulcanization accelerator is in the range of 0.3 to 3 parts by mass.
Examples of the thiuram vulcanization accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, activated tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram monosulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide, Examples include dipentamethylene thiuram hexasulfide, tetrabenzyl thiuram disulfide, and tetrakis (2-ethylhexyl) thiuram disulfide.

On the other hand, as the substituted dithiocarbamate vulcanization accelerator, for example, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium di-n-butyldithiocarbamate, potassium dimethyldithiocarbamate, lead ethylphenyldithiocarbamate, zinc dimethyldithiocarbamate, Zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc dibenzyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc ethylphenyldithiocarbamate, tellurium diethyldithiocarbamate, copper dimethyldithiocarbamate, pentamethylenedithiocarbamate piperidine, etc. Is mentioned.
In the present invention, at least one selected from the thiuram vulcanization accelerator and the substituted dithiocarbamate vulcanization accelerator is used. Among these, the substituted dithiocarbamate vulcanization accelerator is used. Particularly preferred is zinc dibenzyldithiocarbamate.

In the adhesive composition, as the component (e), a resin and / or a low molecular weight polymer is used particularly for sticking workability (adhesion improvement of the adhesive composition).
Examples of the component (e) resin include phenolic resins, modified terpene resins, terpene resins, hydrogenated terpene resins, rosin resins, C ₅ and C ₉ petroleum resins, xylene resins, coumarone indene resins, dicyclopentadiene resins and styrene resins, among these, C ₅ fraction resins, phenol resins, terpene resins, modified terpene resins, hydrogenated terpene resins and rosin-based resin is preferable .
The C ₅ fraction resins, obtained by the thermal cracking of naphtha, usually 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene Polymerized or copolymerized diolefinic hydrocarbons such as olefinic hydrocarbons, 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 3-methyl-1,2-butadiene, etc. Petroleum resin is mentioned.
Examples of the phenolic resin include a resin obtained by condensing pt-butylphenol and acetylene in the presence of a catalyst, and a condensate of alkylphenol and formaldehyde.

Examples of the terpene resin, modified terpene resin, and hydrogenated terpene resin include, for example, terpene resins such as β-pinene resin and α-pinene resin, hydrogenated terpene resins obtained by hydrogenating these resins, and terpenes. And a modified terpene resin in which phenol and phenol are reacted with a Friedel-Craft type catalyst or condensed with formaldehyde.
Examples of the rosin resin include a natural resin rosin and a rosin derivative modified by hydrogenation, disproportionation, dimerization, esterification, limeization or the like. These resins may be used alone, but among these, phenolic resins are particularly preferable.

On the other hand, the low molecular weight polymer preferably has a weight average molecular weight in the range of 1,000 to 100,000 in terms of polystyrene, more preferably 1,000 to 50,000. Moreover, what has a double bond in a molecule | numerator is preferable, and what has a styrene unit further is preferable. An example of such a low molecular weight polymer is a styrene-butadiene copolymer.
This low molecular weight styrene-butadiene copolymer is obtained by using butadiene and styrene in a hydrocarbon solvent such as cyclohexane in the presence of an ether or a tertiary amine to produce butadiene and styrene at 50 to 90 ° C. It can be produced by copolymerizing at a degree. The molecular weight of the obtained copolymer can be controlled by the amount of the organic lithium compound, and the microstructure can be controlled by the amount of ether or tertiary amine.
In the present invention, as the component (e), the low molecular weight polymer may be used alone or in combination of two or more. Alternatively, one or more of the above resins and one or more of the low molecular weight polymers may be used in combination.
In the present invention, the component (e) is preferably used in an amount of 5 parts by mass or more, more preferably 5 to 40 parts by mass, particularly preferably 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component of the component (a). Used in parts ratio.
In particular, an adhesive composition obtained when a phenol resin is used as the component (e) is preferable because it exhibits excellent tackiness.

  In the adhesive composition part, a vulcanizing agent, stearic acid, zinc oxide, an anti-aging agent and the like can be contained as desired within a range that does not impair the object of the present invention.

Next, the manufacturing method of the laminated body used for this invention is demonstrated.
First, each component which comprises the said adhesive composition is added to an organic solvent, and it melt | dissolves or disperses and prepares the coating liquid which consists of an adhesive composition containing an organic solvent.
In this case, as the organic solvent, (a) an organic solvent having a Hildebrand solubility parameter δ value of 14 to 20 MPa ^1/2 which is a good solvent for the rubber component is preferably used. Examples of such an organic solvent include toluene, xylene, n-hexane, cyclohexane, chloroform, methyl ethyl ketone, and the like. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.
The solid content concentration of the coating solution thus prepared is appropriately selected in consideration of coating properties and handleability, but is usually in the range of 5 to 50% by mass, preferably 10 to 30% by mass. is there.
Next, after coating and drying the coating liquid on the surface of the resin film constituting the layer (A), the rubber-like elastic film or sheet constituting the layer (B) is bonded thereon, A laminate used in the present invention is obtained by heating and vulcanization treatment.

Alternatively, after coating and drying the coating liquid on the surface of the rubbery elastic film or sheet constituting the layer (B), the resin film constituting the layer (A) is bonded thereon. By heating and vulcanizing, the laminate used in the present invention is obtained.
Of these two methods, the former method is usually used.
As described above, for example, it is necessary to dry the adhesive layer (C) before applying the coating liquid on the surface of the resin film constituting the layer (A) and laminating with the layer (B). As drying conditions, it is necessary that the volatile content remaining in the (C) adhesive layer when the dried (C) adhesive layer is treated at 120 ° C. for 2 hours is 10% by mass or less. More preferably, it is 5 mass% or less.

As said drying conditions, 60 to 150 degreeC is preferable and 80 to 120 degreeC is more preferable. By setting the drying conditions within the above range, it is possible to suppress a decrease in productivity and a decrease in peeling resistance due to the curing of the adhesive.
The drying time can be appropriately determined depending on the amount of the adhesive composition and the solvent, but the amount of the volatile component remaining in the adhesive layer may be 10% by mass or less.
When the (A) layer and the (B) layer are bonded via the (C) layer containing many volatile components exceeding 10% by mass, and the tire is heated and vulcanized as an inner liner phase, The volatile component volatilizes during the manufacture of the tire and accumulates as bubbles locally in the tire, which may cause performance problems in the tire.
Therefore, it is important that the amount of the volatile component remaining in the adhesive layer (C) is 10% by mass or less, the tackiness is good, the workability is good, and the peel resistance is excellent. A pneumatic tire having an inner liner can be obtained.

In the above method, when the resin film constituting the layer (A) has a modified ethylene-vinyl alcohol copolymer layer in which a flexible resin is dispersed, the resin film and the rubber-like elastic film or sheet are bonded to an adhesive. Before pasting through the composition layer, it is preferable to irradiate the resin film with energy rays in advance to crosslink the modified ethylene-vinyl alcohol copolymer layer. If this cross-linking operation is not performed, the modified ethylene-vinyl alcohol copolymer layer is remarkably deformed in the subsequent heating / vulcanizing step, and a uniform layer cannot be maintained, and the resulting laminate is a tire. There is a possibility that a predetermined function as an inner liner for a product may not be exhibited.
Examples of the energy rays include ionizing radiation such as ultraviolet rays, electron beams, X-rays, α rays, and γ rays, and electron beams are preferable.
As for the electron beam irradiation method, a method of introducing a resin film into an electron beam irradiation apparatus and irradiating the electron beam can be mentioned. Although it does not specifically limit regarding the dose of an electron beam, Preferably it exists in the range of 10-60 Mrad. When the electron dose to irradiate is lower than 10 Mrad, it becomes difficult to crosslink. On the other hand, when the electron dose to be irradiated exceeds 60 Mrad, the deterioration of the resin film easily proceeds. More preferably, the electron dose range is 20 to 50 Mrad.

The heating / vulcanizing treatment is usually performed at a temperature of 100 ° C. or higher, preferably 125 to 200 ° C., more preferably 130 to 180 ° C. In the case of the pneumatic tire of the present invention, the heating / vulcanizing treatment is usually performed at the time of tire vulcanization.
The inner liner layer used in the pneumatic tire of the present invention has characteristics such as good tackiness, good workability, and excellent peeling resistance by using an adhesive composition having a specific composition. ing.
FIG. 1 is a partial sectional view showing an example of a pneumatic tire using an inner liner layer according to the present invention, in which the tire is wound around a bead core 1 and a carcass ply in which a cord direction is directed in a radial direction. A carcass layer 2, an inner liner layer 3 made of a laminate according to the present invention disposed on the inner side in the tire radial direction of the carcass layer, and 2 disposed on the outer side in the tire radial direction of the crown portion of the carcass layer. The belt portion includes a belt portion 4, a tread portion 5 disposed on the upper portion of the belt portion, and sidewall portions 6 disposed on the left and right sides of the tread portion.
FIG. 2 is a cross-sectional detail view of an example of the inner liner layer according to the present invention in the pneumatic tire. The inner liner layer 3 is a modified ethylene-vinyl alcohol copolymer in which a flexible resin is dispersed in a matrix resin. A resin film layer 13 formed by laminating thermoplastic urethane-based elastomer layers 12a and 12b and a rubber-like elastic body layer 15 are bonded to both surfaces of the combined layer 11 via an adhesive layer 14 and integrated. It has a structure. The rubber-like elastic body layer 15 is bonded to the carcass layer 2 in FIG. 1 on the surface opposite to the adhesive layer 14.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Production Example 1 Production of Modified Ethylene-Vinyl Alcohol Copolymer An ethylene-vinyl alcohol copolymer having an ethylene content of 44 mol% and a saponification degree of 99.9 mol% (MFR: 5.5 g / 10 min) was placed in a pressure reaction vessel. 2 parts by weight (under 190 ° C. and 21.18 N load) and 8 parts by weight of N-methyl-2-pyrrolidone were charged and stirred at 120 ° C. for 2 hours to completely dissolve the ethylene-vinyl alcohol copolymer. After adding 0.4 parts by weight of epoxy propane as an epoxy compound to this, it was heated for 4 hours at 160 ° C. After the heating, it was precipitated in 100 parts by weight of distilled water, and a sufficient amount of distilled water was sufficient for N-methyl. -2-pyrrolidone and unreacted epoxypropane were washed to obtain a modified ethylene-vinyl alcohol copolymer. The copolymer was fined to a particle size of about 2 mm with a pulverizer, and then thoroughly washed with a large amount of distilled water again.The washed particles were vacuum-dried at room temperature for 8 hours, and then 200 ° C. using a twin screw extruder. And then pelletized.

The ethylene content and the degree of saponification of the ethylene-vinyl alcohol copolymer were measured by ¹ H-NMR measurement using deuterated dimethyl sulfoxide as a solvent [JIM-GX-500 type manufactured by JEOL Ltd.]. It is a value calculated from the spectrum obtained in [Use]. Also, the melt flow rate (MFR) of the ethylene-vinyl alcohol copolymer was melted at 190 ° C. by filling a sample into a cylinder with an inner diameter of 9.55 mm and a length of 162 mm of a melt indexer L224 (manufactured by Takara Kogyo Co., Ltd.). After that, using a plunger with a weight of 2160 g and a diameter of 9.48 mm, load was evenly applied, and the amount of resin extruded per unit time by an orifice with a diameter of 2.1 mm provided in the center of the cylinder (g / 10 min) I asked for it. However, when the melting point of the ethylene-vinyl alcohol copolymer is around 190 ° C. or exceeds 190 ° C., it is measured at a plurality of temperatures higher than the melting point under a load of 2160 g. The melt flow rate (MFR) was calculated by plotting the logarithm of γ on the vertical axis and extrapolating to 190 ° C.

Production Example 2 Production of flexible resin A maleic anhydride-modified hydrogenated styrene-ethylene-butadiene-styrene block copolymer was synthesized by a known method and pelletized. The obtained maleic anhydride-modified hydrogenated styrene-ethylene-butadiene-styrene block copolymer had a Young's modulus of 3 MPa, a styrene content of 20%, and a maleic anhydride amount of 0.3 meq / g. The Young's modulus of the maleic anhydride-modified hydrogenated styrene-ethylene-butadiene-styrene block copolymer was measured by the following method.

(1) Measurement of Young's modulus Using the obtained pellets, a film was formed by a twin-screw extruder manufactured by Toyo Seiki Co., Ltd. under the following extrusion conditions to produce a single-layer film having a thickness of 20 μm. Next, using this film, a strip-shaped test piece having a width of 15 mm was prepared and left for 1 week in a temperature-controlled room at 23 ° C. and 50% RH, and then autograph [AG-A500 type manufactured by Shimadzu Corporation]. ] Is used to measure the SS curve (stress-strain curve) at 23 ° C. and 50% PH under the conditions of a distance between chucks of 50 mm and a tensile speed of 50 mm / min, and obtain the Young's modulus from the initial slope of the SS curve. It was.

Production Example 3 Production of 3-layer film The modified ethylene-vinyl alcohol copolymer obtained in Production Example 1 and the flexible resin obtained in Production Example 2 were kneaded with a twin screw extruder, and the flexible resin was dispersed in the matrix. A modified ethylene-vinyl alcohol copolymer was obtained. The blending amount of the flexible resin with respect to the modified ethylene-vinyl alcohol copolymer was 20% by mass, and the average particle diameter of the flexible resin in the resin composition measured with a transmission electron microscope was 1.2 μm.
A three-layer film (thermoplastic polyurethane layer) under the following co-extrusion molding conditions using the obtained resin composition and thermoplastic polyurethane (manufactured by Kuraray Co., Ltd., Kuramiron 3190) using a two-type three-layer coextrusion apparatus. / Flexible resin dispersion modified EVOH layer / thermoplastic polyurethane layer). The thickness of each layer is 20 μm for both the flexible resin dispersion-modified EVOH layer and the thermoplastic polyurethane layer.
The coextrusion molding conditions are as follows.
Layer structure:
Thermoplastic polyurethane / flexible resin dispersion modified EVOH / thermoplastic polyurethane (thickness 20/20/20, unit is μm)
Extrusion temperature of each resin:
C1 / C2 / C3 / die = 170/170/220/220 ° C.
Extruder specifications for each resin:
Thermoplastic polyurethane:
25mmφ extruder P25-18AC (manufactured by Osaka Seiki Co., Ltd.)
Resin composition:
20mmφ Extruder Lab Machine ME Type CO-EXT (Toyo Seiki Co., Ltd.)
T-die specification:
500mm width for 2 types and 3 layers (Plastic Engineering Laboratory Co., Ltd.)
Cooling roll temperature: 50 ° C
Pickup speed: 4m / min

Production Example 4 Production of Unvulcanized Rubber-like Elastic Sheet A rubber composition having the following composition was prepared to produce an unvulcanized rubber-like elastic sheet having a thickness of 500 μm.
Rubber composition (compounding unit: parts by mass)
* Natural rubber 30
* Br-IIR: (Bromobutyl 2244 manufactured by JSR Corporation) 70
* GPF carbon black: (Asahi Carbon Corporation # 55) 60
* SUNPAR 2280 (Nihon Sun Oil Co., Ltd.) 7
* Stearic acid: (Asahi Denka Kogyo Co., Ltd.) 1
* Vulcanization accelerator: (Noxeller DM manufactured by Ouchi Shinsei Chemical Co., Ltd.) 1.3
* Zinc oxide: (Shiramizu Chemical Co., Ltd.) 3
* Sulfur: (Karuizawa Smelter) 0.5

Production Example 5 Preparation of Adhesive Composition and Coating Solution Adhesive Composition (Formulation Unit: Mass Part)
* Br-IIR: (Bromobutyl 2244 made by JSR) 90
* Chlorosulfonated polyethylene: (Hypalon manufactured by Dupnt Dow Elastomers LLC) 10
* Carbon black: (Toast Carbon Co., Ltd. Seast NB) 10
* Phenolic resin: (PR-SC-400, manufactured by Sumitomo Bakelite) 20
* Stearic acid: (New Nippon Rika Co., Ltd. 50S) 1
* Zinc oxide: (Hakusuitec manufactured by Hakusui Chemical Co., Ltd.) 3
* P-dinitrosobenzene: (Valnock DNB manufactured by Ouchi Shinsei Chemical Co., Ltd.) 3
* 1,4 phenylene dimaleimide: (Valnock PM manufactured by Ouchi Shinsei Chemical Co., Ltd.) 3
* Vulcanization accelerator: (Ouchi Shinsei Chemical Co., Ltd. Noxeller ZTC) 1
* Vulcanization accelerator: (Noxeller DM manufactured by Ouchi Shinsei Chemical Co., Ltd.) 0.5
* Vulcanization accelerator: (Noxeller D manufactured by Ouchi Shinsei Chemical Co., Ltd.) 1
* Sulfur: (Tsurumi Chemical Co., Ltd. Jinhua seal fine powder sulfur) 1.5
After kneading by a conventional method according to the above composition, the adhesive composition is added to 1000 parts by mass of toluene (δ value: 18.2 MPa ^1/2 ) as an organic solvent, and dissolved or dispersed to apply each adhesive. A liquid was prepared.

Example 1
Three-layer film (thermoplastic polyurethane / soft resin dispersion-modified EVOH / thermoplastic polyurethane) obtained in Production Example 3 using an electron beam irradiation device “Curetron EBC200-100 for production” manufactured by Nissin High Voltage Co., Ltd. The film was irradiated with an electron beam under the conditions of an acceleration voltage of 200 kV and an irradiation energy of 30 Mrad, and subjected to a crosslinking treatment, and used as a multilayer thermoplastic resin film.
To 100 parts by mass of the adhesive composition obtained in Production Example 5, 1000 parts by mass of toluene as an organic solvent was dissolved or dispersed to prepare an adhesive coating solution. The coating solution was applied to one side of the crosslinked multilayer thermoplastic resin film, dried at 100 ° C. for 2 minutes, and then the multilayer thermoplastic resin film having an adhesive layer was cut into a 20 cm square and further 120 ° C. Then, the remaining volatile matter was measured for 2 hours, and the inner liner was prepared by laminating with the unvulcanized rubber-like elastic sheet having a thickness of 500 μm obtained in Production Example 4 in parallel. Using the obtained inner liner, a pneumatic tire for passenger cars (195 / 65R15) was produced through a vulcanization step by a conventional method.
Table 1 shows the appearance evaluation of the inner liner of the prototype tire and the measurement results of the volatile matter remaining in the adhesive layer.

In addition, the measurement of residual volatile matter, the tire inner surface confirmation of the prototype tire, and the determination of availability were performed based on the following methods.
(1) Measurement of the amount of residual volatile components Cross-linked film (a) coated with an adhesive and dried and cross-linked film (b) coated with no adhesive are cut into 20 cm squares, and the respective masses are measured. The resulting mass was set to mass 1 and mass 2, and then they were placed in a constant temperature bath at 120 ° C. for 2 hours, and then the respective masses were measured again. The masses measured were designated as mass 1 ′ and mass 2 ′. The following calculation was performed to determine the amount of volatile components.
Volatile component amount (mass%) = 100− (mass 1′−mass 2 ′) / (mass 1−mass 2) × 100
(2) Prototype tire inner surface confirmation and use availability determination The inner surface of the tire manufactured through the vulcanization process was confirmed. The inner surface property was checked for foaming, and a tire that could be used as a product without any property problem was acceptable.

Example 2
In Example 1, the evaluation was performed in the same manner as in Example 1 except that the drying condition was a process of drying at 100 ° C. for 1 minute. Table 1 shows the appearance evaluation of the inner liner of the prototype tire and the measurement results of the volatile matter remaining in the adhesive layer.

Comparative Example 1
In Example 1, the evaluation was performed in the same manner as in Example 1 except that the drying condition was a treatment for 2 minutes at room temperature. Table 1 shows the appearance evaluation of the inner liner of the prototype tire and the measurement results of the volatile matter remaining in the adhesive layer.

Comparative Example 2
In Example 1, the evaluation was performed in the same manner as in Example 1 except that the drying was performed at 100 ° C. for 10 seconds. Table 1 shows the appearance evaluation of the inner liner of the prototype tire and the measurement results of the volatile matter remaining in the adhesive layer.

  The pneumatic tire of the present invention has an adhesive agent for bonding the thermoplastic resin film layer and the rubber elastic layer when manufacturing a tire using a single layer or multilayer thermoplastic film layer as an inner liner layer that can be made thinner. A laminated body joined and integrated using an adhesive containing the composition, the laminated body having no problems such as production of bubbles derived from the adhesive after heating and vulcanization, and having excellent peeling resistance A pneumatic tire using the body can be provided.

It is a fragmentary sectional view showing an example of the tire of the present invention. It is a cross-sectional detail drawing which shows an example of a structure of the laminated body used for this invention.

Explanation of symbols

1: Beat core 2: Carcass layer 3: Inner liner layer 4: Belt part 5: Tread part 6: Side wall part 7: Bead filler 11: Flexible resin dispersion modified ethylene-vinyl alcohol copolymer layer 12a, 12b: Thermoplastic urethane Elastomer layer 13: Resin film layer 14: Adhesive layer 15: Rubber elastic layer

Claims (24)

  A tire that uses, as an inner liner layer, a multilayer thermoplastic resin film layer including (A) a single layer in which a flexible resin is dispersed in a matrix resin or a layer in which a flexible resin is dispersed in a matrix resin. A coating liquid containing an agent composition is applied to the (A) layer and / or (B) rubber elastic layer and dried (C) to form an adhesive layer, and then the (A) layer and the (B) layer (C) When adhering via an adhesive layer, volatilization when a laminate comprising the (A) layer and / or (B) layer including the adhesive layer is further treated at 120 ° C. for 2 hours The component is 10 mass% or less, The pneumatic tire characterized by the above-mentioned.   (C) The adhesive composition constituting the adhesive layer is (a) a rubber component and per 100 parts by mass of (b) a poly-p-dinitrosobenzene, maleimide derivative as a crosslinking agent and a crosslinking aid. 2. The pneumatic tire according to claim 1, comprising at least 0.1 part by mass of at least one kind.   The pneumatic tire according to claim 2, wherein the maleimide derivative of the component (b) is 1,4-phenylene dimaleimide.   The pneumatic tire according to any one of claims 1 to 3, wherein the adhesive composition contains 10% by mass or more of chlorosulfonated polyethylene as a rubber component (a).   The pneumatic tire according to any one of claims 1 to 4, wherein the adhesive composition further comprises (c) 2 to 50 parts by mass of a filler.   The pneumatic tire according to claim 5, wherein the adhesive composition contains (c) carbon black as a filler.   The pneumatic tire according to any one of claims 1 to 6, wherein in the adhesive composition, (a) the rubber component contains 50 parts by mass or more of butyl rubber and / or halogenated butyl rubber.   The pneumatic tire according to any one of claims 1 to 7, wherein the adhesive composition further includes (d) 0.1 part by mass or more of a rubber vulcanization accelerator.   The pneumatic tire according to claim 8, wherein the (d) rubber vulcanization accelerator is a thiuram-based and / or substituted dithiocarbamate vulcanization accelerator.   The pneumatic tire according to any one of claims 1 to 9, wherein the adhesive composition further includes 0.1 part by weight or more of at least one of (e) a resin and a low molecular weight polymer.   The air according to claim 10, wherein the resin in component (e) is at least one selected from C5 resins, phenol resins, terpene resins, modified terpene resins, hydrogenated terpene resins, and rosin resins. Enter tire.   The pneumatic tire according to claim 11, wherein the resin is a phenolic resin.   The pneumatic tire according to claim 10, wherein the weight average molecular weight of the low molecular weight polymer in component (e) is 1,000 to 100,000 in terms of polystyrene.   The pneumatic tire according to claim 13, wherein the weight average molecular weight of the low molecular weight polymer in component (e) is 1,000 to 50,000 in terms of polystyrene.   The pneumatic tire according to any one of claims 10 to 14, wherein the low molecular weight polymer in component (e) is a polymer having a double bond in the molecule.   The pneumatic tire according to any one of claims 10 to 15, wherein the low molecular weight polymer in component (e) is a polymer containing a styrene unit.   The pneumatic tire according to claim 16, wherein the low molecular weight polymer in component (e) is a styrene-butadiene copolymer.   The thermoplastic resin constituting the matrix in which the flexible resin is dispersed in the matrix resin is an epoxy compound of 1 to 50 weights per 100 parts by weight of an ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 50 mol%. The pneumatic tire according to claim 1, comprising a modified ethylene-vinyl alcohol copolymer obtained by reacting parts.   The flexible resin has a functional group that reacts with a hydroxyl group, Young's modulus is 500 MPa or less, and the content of the flexible resin is 10 to 30% by mass with respect to 100 parts by mass of the modified ethylene-vinyl alcohol copolymer, The pneumatic tire according to any one of claims 1 to 18, comprising a resin composition dispersed in the copolymer with an average particle size of 2 µm or less.   (A) A thermoplastic urethane elastomer is used as a surface layer of a multilayer thermoplastic resin film layer including a single layer in which a flexible resin is dispersed in a matrix resin or a layer in which a flexible resin is dispersed in a matrix resin. The pneumatic tire according to any one of 1 to 19.   The pneumatic tire according to any one of claims 1 to 20, wherein butyl rubber or halogenated butyl rubber is used for the (B) rubber-like elastic body layer.   The pneumatic tire according to claim 1, wherein a diene-based elastomer is used for the (B) rubber-like elastic body layer.   2. A coating solution comprising an adhesive composition containing an organic solvent is applied to a rubbery elastic film or sheet surface and dried, and then a resin film is bonded thereon, followed by heating and vulcanization treatment. The pneumatic tire in any one of -22.   The pneumatic tire according to claim 23, wherein a heating / vulcanizing temperature is 100 ° C or higher.

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