JP5074708B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire. More specifically, when a thermoplastic resin film is used as an inner liner, it is necessary to overlap the end of the inner liner with another end and make it cylindrical through an adhesive layer. It is related to a pneumatic tire that has high shear adhesion during vulcanization, and has a small amount of displacement of the joint part of the green tire (raw tire) that is being stored after molding, and has excellent workability that does not cause problems due to the joint part during manufacturing is there.

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, a single layer or particularly a multilayer thermoplastic resin film having good gas barrier properties and excellent flexibility can be considered. In this case, it is necessary to joint the resin film layer into a cylindrical shape via an adhesive layer, but the joint portion has a high shear adhesive force when unvulcanized, and is a green tire (raw tire) that is being stored after molding. The amount of shift of the joint part is required to be small.

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 uses a single-layer or multilayer thermoplastic resin film layer having good gas barrier properties and excellent flexibility as an inner liner, and the resin film layer is formed into a cylindrical shape via an adhesive layer. Provides a pneumatic tire with excellent molding workability, with high shear adhesion when unvulcanized, and little slippage of the joint of a green tire (raw tire) that is being stored after molding. It is intended to do.

As a result of intensive studies to achieve the above object, the present inventors have determined that a single-layer or multilayer thermoplastic resin film layer having a good gas barrier property and excellent flexibility is an adhesive composition having a specific composition. It was found that the object can be achieved by jointing through an adhesive layer composed of The present invention has been completed based on such findings.
That is, the present invention
(1) When manufacturing a tire using (A) a single layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via the (B) adhesive layer, A pneumatic tire characterized by having a shear adhesion during vulcanization of 10 kPa or more,
(2) When manufacturing a tire using (A) a single-layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via the (B) adhesive layer and deviates after molding the tire. The pneumatic tire of (1) above, wherein the joint length (deviation amount) of the joint portion of the green tire is 5 mm / day or less when unvulcanized,
(3) When manufacturing a tire using (A) a single layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via the (B) adhesive layer, The above (1) or (2), wherein the vulcanization shear adhesive strength is 10 kPa or more and the joint length (displacement amount) of the joint portion of the green tire which is displaced after the tire molding is 5 mm / day or less when unvulcanized. Pneumatic tires,
(4) The pneumatic tire according to any one of the above (1) to (3), wherein the unbonded joint portion has a shear adhesive strength of 40 kPa or more,
(5) The pneumatic tire according to any one of (1) to (4), wherein the joint length (deviation amount) of the joint portion of the green tire that is shifted after the tire molding is 2 mm / day or less when unvulcanized.
(6) The (A) single layer or multilayer thermoplastic resin film layer reacts 1 to 50 parts by weight of an epoxy compound with respect to 100 parts by weight of an ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 50 mol%. A pneumatic tire according to any one of the above (1) to (5), comprising a layer comprising a modified ethylene-vinyl alcohol copolymer obtained by
(7) (A) The pneumatic tire according to any one of the above (1) to (6), wherein a thermoplastic urethane-based elastomer is used as the surface layer of the single-layer or multilayer thermoplastic resin film layer,
(8) The pneumatic tire according to any one of the above (1) to (7), wherein the (A) layer constitutes the (B) adhesive layer (C) is adhered using the adhesive composition,
(9) (C) Adhesive composition comprises (a) rubber component and 100 parts by mass thereof, (b) poly-p-dinitrosobenzene, 1,4-phenylene dimaleimide as a crosslinking agent and crosslinking aid The pneumatic tire of (8) above, containing at least one part of
(10) The pneumatic tire according to (9), wherein (C) the adhesive composition includes (a) 10% by mass or more of chlorosulfonated polyethylene as a rubber component,
(11) (C) The pneumatic tire according to any one of (8) to (10), wherein the adhesive composition further includes (c) 2 to 50 parts by mass of a filler,
(12) The pneumatic tire according to (11), wherein (C) the adhesive composition contains (c) carbon black as a filler,
(13) The pneumatic tire according to any one of (8) to (12) above, wherein (a) the rubber component contains 50 parts by mass or more of butyl rubber and / or halogenated butyl rubber in the adhesive composition.
(14) (C) The pneumatic tire according to any one of (8) to (13), wherein the adhesive composition further includes (d) 0.1 part by mass or more of a rubber vulcanization accelerator,
(15) The pneumatic tire according to (14), wherein (d) the rubber vulcanization accelerator is a thiuram-based and / or substituted dithiocarbamate-based vulcanization accelerator,
(16) (C) The pneumatic tire according to any one of (8) to (15), 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,
(17) The above (16), wherein the resin in component (e) is at least one selected from a C5 resin, a phenol resin, a terpene resin, a modified terpene resin, a hydrogenated terpene resin, and a rosin resin. Pneumatic tires,
(18) The pneumatic tire according to (17), wherein the resin is a phenol resin.
(19) The pneumatic tire according to (16), 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,
(20) The pneumatic tire according to (19), wherein the weight average molecular weight of the low molecular weight polymer in component (C) is 1,000 to 50,000 in terms of polystyrene,
(21) The pneumatic tire according to any one of the above (16) to (20), wherein the low molecular weight polymer in the component (e) is a polymer having a double bond in the molecule.
(22) The pneumatic tire according to any one of the above (16) to (21), wherein the low molecular weight polymer in the component (e) is a polymer containing a styrene unit, and (23) the low molecular weight polymer in the component (e) Is a styrene-butadiene copolymer, the pneumatic tire of (22) above,
Is to provide.

  According to the present invention, a single layer or multilayer thermoplastic resin film layer having a good gas barrier property and excellent flexibility is used as an inner liner layer, and the resin film layer is jointed into a cylindrical shape via an adhesive layer. It is possible to provide a pneumatic tire excellent in molding workability with a high shear adhesive strength at the time of unvulcanization of the joint portion and a small shift amount of the joint portion of the green tire during storage after molding.

First, when the pneumatic tire of the present invention is a tire using (A) a single-layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via the (B) adhesive layer. And the uncured shear adhesive strength of the joint portion is 10 kPa or more.
The joint strength at the time of unvulcanized joint portion needs to be 10 kPa or more, and more preferably 40 kPa or more. In addition, the joint length (deviation amount) of the joint portion of the green tire that shifts during storage after molding the tire is preferably 5 mm / day or less when unvulcanized, and 2 mm / day or less when unvulcanized. It is more preferable.
In particular, the inner liner used in the present invention by setting the shear adhesive strength of the joint portion when not vulcanized to the above range is excellent in gas barrier properties and bending resistance, and causes defects due to the joint portion during production. A pneumatic tire having excellent molding workability can be obtained.
There is no particular limitation on the upper limit of the shear adhesive strength of the joint, but it is usually 400
It is about kPa.
Here, “joint” usually refers to the overlapping of both ends of the inner liner layer.
There are no particular restrictions on the joint width.
In addition, it is appropriately determined depending on tire size and the like, but is usually about 5 to 20 mm.
Further, the “green tire” refers to an unvulcanized raw tire after molding.

The thermoplastic film constituting the layer (A) in the pneumatic tire of the present invention is not particularly limited as long as it has good gas barrier properties and appropriate mechanical strength, and various resin films can be used. Can be used. 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 performed by reacting the part. 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.

Further, the thermoplastic urethane elastomer (hereinafter sometimes abbreviated as TPU) of the thermoplastic resin film constituting the layer (A) in the pneumatic tire of the present invention has a urethane group (—NH— in the molecule). COO-) is an elastomer having a three-component intermolecular reaction of (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 (a) 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. 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 (A) resin film layer preferably includes a thermoplastic urethane-based elastomer layer, particularly includes a thermoplastic urethane-based elastomer layer, and further includes one or more of the modified ethylene-vinyl alcohol copolymer layer. A layer made of a multilayer film is preferred.
As a specific example of such a multilayer film, a multilayer film having a three-layer structure in which a thermoplastic urethane-based elastomer film is laminated on both sides of the modified ethylene-vinyl alcohol copolymer film can be exemplified.
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 present invention, (A) a single-layer or multi-layer thermoplastic resin film (B) an adhesive layer is composed of (B) an adhesive layer, and (C) an adhesive composition is used for shear bonding during unvulcanized It is preferable from the viewpoint of improving power. The (B) adhesive composition constituting the (B) adhesive layer includes (a) a rubber component and 100 parts by mass of (b) a poly-p-dinitrosobenzene as a crosslinking agent and a crosslinking aid. 1,4-phenylene dimaleimide having a composition containing at least one part by mass of 0.1 part by mass or more is used.
In the adhesive composition, (a) the rubber component is not particularly limited, and (A) the thermoplastic resin film layers in the joint portion, or (A) the rubber-like elastic layer adjacent to the thermoplastic resin film layer. Although it is determined as appropriate depending on the type and the combination thereof to ensure excellent tackiness and average peeling force, it is usually preferable to use 50% by mass or more of butyl rubber and / or halogenated butyl rubber or diene rubber. .
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). .
The component (a) preferably contains 70 to 100% by mass of halogenated butyl rubber from the viewpoints of workability of the adhesive layer and average peeling force.
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.

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 viewpoint of improvement in average peeling force and heat resistance of the adhesive layer, those containing 10 to 40% by mass of CSM are preferable.
In the present invention, from the viewpoint of the average peeling force, 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 average peeling force after heat treatment, (b) at least one of poly-p-dinitrosobenzene and 1,4-phenylenedimaleimide as a crosslinking agent and a crosslinking aid. It is preferable to blend 0.1 part by mass or more of one kind.
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.
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 adhesive composition, the content of the filler as the component (c) is 2 to 50 in terms of tackiness and average peeling force per 100 parts by mass of the rubber component as the component (a). It is selected in the range of parts by mass, preferably 5 to 35 parts by mass.

  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. It is also possible to use this Chemlock 6250 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 exhibits a desired average peeling force. Can do. 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 the thiuram-based and / or substituted dithiocarbamate-based vulcanization accelerator, the obtained laminate can exhibit a desired average peeling force. 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 (C) 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 (A) layer, the green tire is subjected to a molding process in which the (A) layer is jointed via the (B) adhesive layer. The pneumatic tire of the present invention is obtained by heating and vulcanizing the tire.

In the above method, when the resin film constituting the layer (A) has a modified ethylene-vinyl alcohol copolymer layer, the resin film and the rubber-like elastic film or sheet are pasted via the adhesive composition layer. Before combining, the modified ethylene-vinyl alcohol copolymer layer is preferably crosslinked by irradiating the resin film with energy rays in advance. 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 is jointed by using an adhesive composition having a specific composition, so that the joint portion has good tackiness and excellent shear adhesive force when unvulcanized, etc. It has the characteristics.
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 used in 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.
Although not shown, the inner liner layer 3 is overlap-joined via an adhesive 14.
FIG. 2 is a detailed cross-sectional view of an example of the inner liner layer according to the present invention in the pneumatic tire. The inner liner layer 3 is formed on both surfaces of the modified ethylene-vinyl alcohol copolymer layer 11 with thermoplastic urethane. It has a structure composed of a resin film layer 13 formed by laminating the system elastomer layers 12 a and 12 b and an 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 saponification degree 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. ] Is a value calculated from the spectrum obtained in [1]. 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 three-layer film Using the modified EVOH obtained in Production Example 1 and thermoplastic polyurethane (Kuraray Co., Ltd., Kuramylon 3190) as an elastomer, using a two-type three-layer coextrusion apparatus, A three-layer film (thermoplastic polyurethane layer / modified EVOH layer / thermoplastic polyurethane layer) was produced under the following coextrusion molding conditions. The thickness of each layer is 20 μm for both the modified EVOH layer and the thermoplastic polyurethane layer.
The coextrusion molding conditions are as follows.
Layer structure:
Thermoplastic polyurethane / 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.)
Modified EVOH:
20mmφ Extruder Lab Machine ME Type CO-EXT (Toyo Seiki Co., Ltd.)
T-die specification:
500mm width for 2 types and 3 layers (Plastics Engineering Laboratory Co., Ltd.)
Cooling roll temperature: 50 ° C
Pickup speed: 4m / min

Production Example 3 Preparation of Adhesive Composition-1 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 knead | mixing by a conventional method according to the said mixing | blending composition, this adhesive composition was added to 1000 mass parts of toluene as an organic solvent, and it melt | dissolved or disperse | distributed and prepared each adhesive coating liquid.

Production Example 4 Preparation of Adhesive Composition-2 and Coating Solution An adhesive composition and a coating solution were prepared in the same manner as in Production Example 3 except that the amount of carbon black was 60 parts by mass.

Production Example 5 Preparation of Adhesive Composition-3 and Coating Solution An adhesive composition and a coating solution were prepared in the same manner as in Production Example 3 except that the amount of carbon black was 45 parts by mass.

Production Example 6 Preparation of Adhesive Composition-4 and Coating Solution Adhesive Composition and Coating were conducted in the same manner as in Production Example 3 except that the amount of carbon black was 60 parts by mass and the amount of phenol resin was 5 parts by mass. The liquid was prepared.

Production Example 7 Preparation of Adhesive Composition-5 and Coating Solution Adhesive Composition and Coating were conducted in the same manner as in Production Example 3 except that the amount of carbon black was 45 parts by mass and the amount of phenol resin was 5 parts by mass. The liquid was prepared.

Example 1
Using the Nisshin High Voltage Co., Ltd. electron beam irradiation device "Curetron EBC200-100 for production", the three-layer film (thermoplastic polyurethane / modified EVOH / thermoplastic polyurethane) obtained in Production Example 2 was accelerated. The film was irradiated with an electron beam under the conditions of a voltage of 200 kV and an irradiation energy of 30 Mrad, subjected to crosslinking treatment, and used as a multilayer thermoplastic resin film.
To 100 parts by mass of the adhesive composition-1 obtained in Production Example 3, 1000 parts by mass of toluene as an organic solvent was dissolved or dispersed to prepare an adhesive coating solution. The coating solution is applied to one side of the above-mentioned cross-linked multilayer thermoplastic resin film, dried, and then a test sample is prepared by laminating the adhesive-coated surface and the non-adhesive surface of the film. Shear adhesive strength measurement and holding power test were carried out.
Further, the film is cut into a rectangular shape, and is formed into a cylindrical shape by overlapping the adhesive-coated surface at one end and the non-coated surface at the other end to form a cylindrical shape. An unvulcanized tire (for 195 / 65R15) using a multilayer thermoplastic resin film as an inner liner was produced. The joint width was 10 mm. The obtained green tire was allowed to stand at room temperature for one day, and the joint properties of the multilayer thermoplastic resin film joint portion on the inner surface of the tire were confirmed to evaluate whether or not the tire could be manufactured.
Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

In addition, about the shearing adhesive force, holding force (deviation amount), and confirmation of the joint part of the molded tire, measurement and evaluation were performed based on the following methods.
(1) Measurement of shear adhesive strength Shear adhesive strength: A test sample film was fixed to a stainless steel plate in accordance with JIS Z1541, and the film was laminated as shown in the above example, followed by one reciprocal pressing with a 5 kg roller, and cured for 72 hours. Measure the maximum load until the specimen breaks at 23 ° C and a tensile speed of 50 mm / min.
(2) Measurement of holding force (displacement) Based on JIS Z1541, the test piece which stuck the film like the said Example on the stainless steel plate was affixed, and the shift | offset | difference was measured by applying a 9.8N load at room temperature.
(3) Confirmation of joint part of green tire after molding As described in the above embodiment, the obtained green tire is allowed to stand at room temperature for one day, and the properties of the joint of the multilayer thermoplastic film joint part on the inner surface of the green tire are determined. It was confirmed that the joint part was peeled off and the tire that could not be manufactured as a tire was rated as x, and the tire that could be manufactured without any problem as a tire was rated as ○.

Example 2
In Example 1, evaluation was performed in the same manner as in Example 1 except that the adhesive composition obtained in Production Example 5 was used. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

Example 3
In Example 1, evaluation was performed in the same manner as in Example 1 except that the adhesive composition obtained in Production Example 7 was used. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

Comparative Example 1
In Example 1, evaluation was performed in the same manner as in Example 1 except that the adhesive composition of Production Example 3 was not applied. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

Comparative Example 2
In Example 1, it evaluated similarly to Example 1 except having apply | coated the commercially available adhesive composition which is the metalloc R-46 by Toyo Chemical Laboratory. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

Comparative Example 3
In Example 1, evaluation was performed in the same manner as in Example 1 except that the adhesive composition of Production Example 4 was used. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

Comparative Example 4
In Example 1, evaluation was performed in the same manner as in Example 1 except that the adhesive composition of Production Example 6 was used. Table 1 shows the results of confirming the shear adhesive force, the holding force (deviation amount), and the joint properties of the molded thermoplastic resin film joint.

  The pneumatic tire of the present invention uses a single-layer or multilayer thermoplastic resin film layer having good gas barrier properties and excellent flexibility as an inner liner layer, and in the molding step, the resin film layer is interposed via an adhesive layer. When jointing into a cylindrical shape, it is possible to provide a pneumatic tire excellent in molding workability, in which the joint portion has high unbonded shear adhesive strength and the amount of deviation of the joint portion of the green tire after molding is small.

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 portion 5: Tread portion 6: Side wall portion 7: Bead filler 11: Modified ethylene-vinyl alcohol copolymer layer 12a, 12b: Thermoplastic urethane-based elastomer layer 13: Resin film layer 14: Adhesive layer

Claims (11)

When manufacturing a tire using (A) a single layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via the (B) adhesive layer, and the joint portion is unvulcanized. The shear adhesive strength is 10 kPa or more, the (A) layer is bonded using the (C) adhesive composition that constitutes the (B) adhesive layer, and the (a) rubber component of the (C) adhesive composition is a pneumatic tire which comprises brominating Buchirugo arm 5 0 mass% or more and a chlorosulfonated polyethylene 10 wt% or more.   When manufacturing a tire using (A) a single layer or multilayer thermoplastic resin film as an inner liner layer, the (A) layer is jointed via (B) an adhesive layer, and the green tire is displaced after the tire is molded. The pneumatic tire according to claim 1, wherein the joint length (deviation amount) of the joint portion is 5 mm / day or less when unvulcanized.   The pneumatic tire according to claim 1 or 2, wherein the unbonded joint portion has a shear adhesive strength of 40 kPa or more.   The pneumatic tire according to any one of claims 1 to 3, wherein the joint length (deviation amount) of the joint portion of the green tire that is displaced after the tire molding is 2 mm / day or less when unvulcanized.   The (A) single layer or multilayer thermoplastic resin film layer is obtained by reacting 1 to 50 parts by mass of an epoxy compound with 100 parts by mass of an ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 50 mol%. The pneumatic tire according to claim 1, comprising a layer made of a modified ethylene-vinyl alcohol copolymer.   The pneumatic tire according to any one of claims 1 to 5, wherein a thermoplastic urethane elastomer is used as a surface layer of the (A) single-layer or multilayer thermoplastic resin film layer.   The (C) adhesive composition comprises (a) a rubber component and 100 parts by mass of (b) a poly-p-dinitrosobenzene or 1,4-phenylene dimaleimide as a crosslinking agent and a crosslinking aid. The pneumatic tire according to any one of claims 1 to 6, comprising at least one part by mass of 0.1 part by mass or more. The pneumatic tire according to any one of claims 1 to 7 , wherein the (C) adhesive composition further includes (c) 2 to 50 parts by mass of a filler. The pneumatic tire according to claim 8 , wherein the adhesive composition (C) includes carbon black as a filler (c). The pneumatic tire according to any one of claims 1 to 9 , wherein the (C) adhesive composition further includes (d) 0.1 part by mass or more of a rubber vulcanization accelerator. The pneumatic tire according to claim 10 , wherein (d) the rubber vulcanization accelerator is a thiuram-based and / or substituted dithiocarbamate vulcanization accelerator.

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