JP6068005B2 - Pneumatic tire and manufacturing method thereof - Google Patents

Description

  The present invention relates to a laminate having a layer containing a thermoplastic resin film and a rubber layer, and a method for producing a pneumatic tire using the laminate.

Conventionally, a rubber layer mainly composed of butyl rubber has been generally used as an inner liner layer of a pneumatic tire. However, a thin resin film having a low gas permeability has been developed in accordance with a recent demand for weight reduction of a tire. It has been proposed to use
As a conventional method of manufacturing a pneumatic tire using this resin film as an inner liner, a resin film is wound around a tire molding drum, and members such as carcass and tread made of unvulcanized rubber are sequentially wound thereon. After being stacked, the drum is pulled out to obtain a green tire, and this green tire is heated and vulcanized to obtain a pneumatic tire (for example, paragraph 0042 of Patent Document 1).

  However, since there is no adhesion by co-vulcanization between the carcass made of these unvulcanized rubber and the resin film, there is a problem that they may be peeled off. It is also conceivable to prepare a laminate in which a rubber layer is lined on a resin film in advance. However, when this laminate is wound on a tire molding drum, the resin film on one end side and the rubber layer on the other end side overlap at the overlap portion at both ends of the laminate, and peeling occurs at this overlap portion. There are things to do.

Accordingly, various techniques have been proposed to solve the problem of peeling between the resin film and the carcass.
For example, Patent Document 2 proposes a technique that uses a resin film that forms an inner liner layer and is formed into a cylindrical shape without a joint.
Patent Document 3 discloses a technique in which a laminated body formed by lining a rubber layer on the surface of a resin film is wound around a tire molding drum, and then the overlapping portions at both ends of the laminated body are bonded with an adhesive layer for an end. Has been proposed.
Patent Document 4 proposes a laminate comprising a thermoplastic resin film and an adhesive layer on the surface thereof, and a rubber sheet attached to the adhesive layer while being shifted in the length direction. In this laminate, the surface of the adhesive layer is exposed at one end, and the back surface of the rubber sheet is exposed at the other end. When this laminate is wound on a tire molding drum, the adhesive layer on one end of the laminate and the rubber sheet on the other end adhere to each other to prevent peeling at the overlapping portion of the laminate. Is done.

JP 10-025375 A JP 2002-283808 A JP 2007-276631 A JP 2010-005986 A

The techniques of Patent Documents 1 to 4 have problems such as peeling of the overlapping portion of the laminated body, an increase in inventory management cost, a decrease in production efficiency, an increase in the number of parts, and a deterioration in winding workability on a forming drum.
That is, according to Patent Document 1, as described above, there is a risk of peeling at the overlapping portion that occurs when the laminate is wound around the tire forming drum.
According to Patent Document 2, it is necessary to prepare cylindrical thermoplastic resin films having various dimensions according to the tire size, and there are problems such as an increase in inventory management cost and a decrease in production efficiency.
According to Patent Document 3, the number of parts is increased by the amount of the edge adhesive layer, and the labor of transferring and laminating the edge adhesive layer is required.
According to Patent Document 4, since it is necessary to stagger each layer in the laminated body, it takes time for the laminating operation, and since the adhesive layer is exposed at one end in the length direction, it is on the forming drum. Wrapping workability is poor.
The present invention has been made under such circumstances, and peeling of the overlapped portion of the laminated body is prevented, the inventory management cost is low, the production efficiency is high, the number of parts is not increased, and the molding drum is onto. An object of the present invention is to provide a laminate including a thermoplastic resin film and a rubber layer excellent in winding workability, and a method for producing a pneumatic tire using the laminate.

As a result of intensive studies to achieve the above object, the present inventors have achieved the object by using a modified diene polymer as a rubber layer in a laminate having a thermoplastic resin film and a rubber layer. I found out that I could do it.
The present invention has been completed based on such findings.

That is, the present invention provides the following [1] to [2].
[1] A layer including a thermoplastic resin film having a laminated structure of a thermoplastic resin film (A layer) and a layer composed of a resin composition including an elastomer (B layer) having a total number of layers of 7 or more, and a rubber layer A pneumatic tire using a laminate having
The rubber layer contains two or more kinds of modified diene polymers having different modification rates ;
The pneumatic tire is characterized in that the laminated body is arranged as an inner liner so that the rubber layer is on the outside and the layer containing the thermoplastic resin film is on the inside.
[2] The laminate according to [1] is wound around a tire molding drum so that the rubber layer is on the outside, and further a tire member is wound, and then the molding drum is pulled out to obtain a green tire. The manufacturing method of the pneumatic tire which heat vulcanizes and makes a pneumatic tire.

  According to the present invention, it is possible to prevent the overlapped portion of the laminate from being peeled off, the inventory management cost is low, the production efficiency is high, the number of parts is not increased, and the thermoplastic resin is excellent in winding workability on a molding drum. A laminate including a film and a rubber layer and a method for producing a pneumatic tire using the laminate can be provided.

It is typical sectional drawing which shows an example of the laminated body of this invention. It is a schematic diagram explaining the process of winding the laminated body of FIG. 1 around a tire molding drum. FIG. 3 is a schematic cross-sectional view of an overlapping portion of the laminated body after the laminated body of FIG. 2 is wound around a tire molding drum. It is a fragmentary sectional view of a pneumatic tire.

[Laminate]
The laminate of the present invention is a laminate having a layer containing a thermoplastic resin film and a rubber layer, and the rubber layer contains a modified diene polymer.
Hereinafter, the laminate of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the laminate of the present invention, FIG. 2 is a schematic view for explaining a process of winding the laminate of FIG. 1 around a tire molding drum, and FIG. It is a typical sectional view of an overlap part of a layered product after winding a layered product around a tire forming drum.

A laminate 10 in FIG. 1 is a laminate 10 having a layer 11 including a thermoplastic resin film and a rubber layer 12, and the rubber layer 12 contains a modified diene polymer. In addition, the code | symbol 10a shows the left end part of this laminated body 10, and the code | symbol 10b shows the right end part of this laminated body 10. FIG. The laminate 10 has an end 10a and an end 10b.
Since the rubber layer 12 contains a modified diene polymer, the rubber layer 12 is excellent in adhesiveness with the layer 11 including a thermoplastic resin film. For this reason, it is excellent in the adhesiveness of the overlapping part formed by overlapping the end portions 10a and 10b of the laminated body 10.

That is, although details will be described later, when a pneumatic tire using the laminate 10 is manufactured, the layer 11 including the thermoplastic resin film faces the outer peripheral surface of the tire molding drum 20 as shown in FIG. Thus, the laminate 10 is wound around the tire molding drum 20. As shown in FIG. 3, after this winding, an overlapped portion is formed by the surface of the layer 11 including the thermoplastic resin film in the vicinity of the left end portion 10a of the laminate 10 and the surface of the rubber layer 12 in the vicinity of the right end portion 10b. The And as above-mentioned, since the rubber layer 12 containing this modified diene type polymer is excellent in adhesiveness with the layer 11 containing a thermoplastic resin film, it is excellent in the adhesiveness of this overlapping part.
Next, the layer including the thermoplastic resin film and the rubber layer will be described in this order.

<Layer containing thermoplastic resin film>
The layer containing a thermoplastic resin film has a laminated structure of a thermoplastic resin film (A layer) and an elastomer layer (B layer) made of a resin composition containing an elastomer.
The layer containing the thermoplastic film may consist of a single layer of the thermoplastic resin film (A layer), or may consist of two or more layers of the thermoplastic resin film (A layer). You may consist of two or more layers of a resin film (A layer) and another layer. The other layer is preferably a layer (B layer) made of a resin composition containing an elastomer having high stretchability. Thereby, even when the stretchability of a thermoplastic resin film (A layer) is low, the whole stretchability of the layer containing a thermoplastic resin film can be improved.

  Hereinafter, the layer structure (multilayer structure) in the case where the layer containing the thermoplastic resin film consists of multiple layers (multilayer structure), the thermoplastic resin film (A layer), the layer made of the resin composition containing the elastomer (B layer), the A layer and B The relationship with the layers and the method for manufacturing the multilayer structure will be described in this order.

≪Layer structure (multilayer structure) ≫
The multilayer structure preferably includes a total of two or more layers of a thermoplastic resin film (A layer) and a layer (B layer) made of a resin composition containing an elastomer. As a result, it has a low gas permeable A layer and a highly extensible B layer, and the layer including the thermoplastic resin film as a whole is low gas permeable and crack resistant in a low temperature environment. Excellent in properties.

From such a viewpoint and a manufacturing viewpoint, the layer including the thermoplastic resin film is preferably a multilayer structure composed of three or more layers. Furthermore, the layer including the thermoplastic resin film is more preferably a multilayer structure composed of 7 or more layers. That is, the total number of layers A and B is preferably 3 or more, and more preferably 7 or more.
Further, the total number of layers of the A layer and the B layer is more preferably 17 layers or more, particularly preferably 25 layers or more, particularly preferably 48 layers or more, and extremely preferably 65 layers or more. The multilayer structure may be a multilayer structure, and the total number of layers A and B may be 128 or more, 256 or more, 512 or more, or 1,024 or more. The upper limit of the total number of layers is appropriately selected depending on the use of the multilayer structure.

The multilayer structure can also have a C layer other than the A layer and the B layer. In addition, as the stacking order of the A layer and the B layer, for example,
(1) A, B, A, B... A, B (that is, (AB) _n )
(2) A, B, A, B... A (that is, (AB) _n A)
(3) B, A, B, A... B (that is, (BA) _n B)
(4) A stacking order such as A, A, B, B... B, B (that is, (AABB) _n ) can be employed. Moreover, when it has other C layers, for example,
(5) A stacking order such as A, B, C... A, B, C (that is, (ABC) _n ) can be adopted. In the above (1) to (5), n is an integer of 1 or more.

  In particular, as the stacking order of the A layer and the B layer, it is preferable that the A layer and the B layer are alternately stacked as in the above (1), (2), or (3). The layered body in which the A layer and the B layer are alternately stacked in this way may be irradiated with active energy rays, thereby improving the bonding property between the stacked layers and exhibiting high adhesiveness. it can. As a result, the interlayer adhesion of the multilayer structure, as well as the low gas permeability and the bending resistance, can be significantly improved. Moreover, since the A layer is sandwiched between the B layers from both sides by alternately laminating the A layer and the B layer, the stretchability of the A layer is further improved.

  In this multilayer structure, the average thickness of each layer of the A layer and the B layer is preferably 0.001 to 10 μm, and more preferably 0.001 to 40 μm. By setting the average thickness of one layer of the A layer and the B layer in the above range, the number can be increased even when the entire thickness of the multilayer structure is the same. Property, bending resistance, and the like can be further improved.

  In the multilayer structure, since the B layer made of the resin composition containing the elastomer is laminated together with the A layer having the thickness in the above range, even when the stretchability of the gas barrier resin itself is low The stretchability of the A layer made of a resin composition having low properties can be further increased. This is because the low stretchable resin composition is transferred to a highly stretchable state by thinly laminating the A layer made of the poorly stretchable resin composition on the stretchable B layer. Conceivable. The present inventor pays attention to the above fact, and the A layer is generally made of a material having low stretchability. Thus, by making the thickness of each layer very thin, a low gas required for a layer including a thermoplastic resin film is required. Highly compatible with permeability and bending resistance. Therefore, even when the multilayer structure is used after being deformed such as bending, characteristics such as low gas permeability can be maintained.

  The lower limit of the average thickness of the A layer is 0.001 μm, preferably 0.005 μm, and more preferably 0.01 μm. On the other hand, the upper limit of the average thickness of the single layer A is 10 μm, preferably 7 μm, more preferably 5 μm, further preferably 3 μm, further preferably 1 μm, further preferably 0.5 μm, 0.2 μm and further 0 .1 μm is particularly preferable, and 0.05 μm is most preferable.

  If the average thickness of one layer A is smaller than the above lower limit, it becomes difficult to mold with a uniform thickness, and the low gas permeability and bending resistance of the multilayer structure may be reduced. Conversely, if the average thickness of the single layer A exceeds the upper limit, the durability and crack resistance of the multilayer structure may be reduced when the thickness of the entire multilayer structure is the same. Moreover, when the average thickness of one A layer exceeds the said upper limit, there exists a possibility that the extending | stretching improvement of A layer mentioned above may not fully express. In addition, the average thickness of one layer of A layer means the value which remove | divided the sum total of the thickness of all the A layers contained in the said multilayered structure by the number of layers of A layer.

  The lower limit of the average thickness of the B layer is 0.001 μm, but 0.005 μm is preferable and 0.01 μm is more preferable for the same reason as the A layer. On the other hand, the upper limit of the average thickness of the B layer is 40 μm, preferably −20 μm, and more preferably 20 μm or less. If the average thickness of one layer B exceeds the above upper limit, the durability and crack resistance of the multilayer structure may be reduced when the thickness of the entire multilayer structure is the same. In addition, the average thickness of one layer of B layer means the value which remove | divided the sum total of the thickness of all the B layers contained in the said multilayered structure by the number of layers of B layer.

  Regarding the average thickness of the B layer, the ratio of the average thickness of the B layer to the average thickness of the A layer (B layer / A layer) is preferably 1/3 or more, more preferably 1/2 or more. It is more preferable. Further, the ratio is preferably 1 or more, that is, the average thickness of one layer B is more than or equal to the average thickness of one layer A, more preferably 2 or more. By making the ratio of the thicknesses of the A layer and the B layer in this way, the bending fatigue characteristics until the multilayer structure reaches the entire layer breakage is improved.

  The thickness of the multilayer structure is preferably 0.1 μm or more and 1,000 μm or less, more preferably 0.5 μm or more and 750 μm or less, and further preferably 1 μm or more and 500 μm or less. By making the thickness of the multilayer structure in the above range, while maintaining the average thickness of one layer of the A layer and B layer in the above range, while maintaining the applicability to an inner liner of a pneumatic tire, etc. Gas barrier properties, flex resistance, crack resistance, durability, stretchability, and the like can be further improved. Here, the thickness of the multilayer structure is obtained by measuring the thickness of the cross section at an arbitrarily selected point of the multilayer structure.

≪Thermoplastic resin film (A layer) ≫
In the thermoplastic resin film (A layer), a flexible resin (A2) having a dynamic storage elastic modulus E ′ at −20 ° C. lower than that of the thermoplastic resin (A1) is dispersed in a matrix made of the thermoplastic resin (A1). The resin composition (A3) may contain at least a layer.
Here, the “dynamic storage elastic modulus E ′ at −20 ° C.” is a condition of initial strain 10%, dynamic strain 0.1%, frequency 15 Hz, −20 ° C. using a spectrometer manufactured by Ueshima Seisakusho Co., Ltd. It is the dynamic storage elastic modulus E ′ measured in (1).
As the thermoplastic resin (A1), the dynamic storage elastic modulus E ′ at −20 ° C. preferably exceeds 1 × 10 ⁸ Pa. Specifically, the polyamide resin, the polyvinylidene chloride resin, the polyester resin , Thermoplastic urethane elastomers, ethylene-vinyl alcohol copolymer resins, and the like. Among these, ethylene-vinyl alcohol copolymer resins are preferable. Such an ethylene-vinyl alcohol copolymer-based resin has a low air permeability and a very good low gas permeability. In addition, these thermoplastic resins (A1) may be used individually by 1 type, and may be used in combination of 2 or more type.

On the other hand, the flexible resin (A2) requires that the dynamic storage elastic modulus E ′ at −20 ° C. is lower than that of the thermoplastic resin (A1), and is preferably 1 × 10 ⁸ Pa or less. When the pressure is not more than 10 ⁸ Pa, the elastic modulus of the thermoplastic resin film (A layer) can be lowered, and as a result, the crack resistance and the bending resistance in a low temperature environment can be improved.
Moreover, it is preferable that the said flexible resin (A2) has a functional group which reacts with a hydroxyl group. When the flexible resin (A2) has a functional group that reacts with a hydroxyl group, the flexible resin (A2) is uniformly dispersed in the thermoplastic resin (A1). 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 (A2) 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. It is done.
Furthermore, the flexible resin (A2) preferably has an average particle size of 2 μm or less. If the average particle diameter of the flexible resin (A2) exceeds 2 μm, the bending resistance of the thermoplastic resin film (A layer) may not be sufficiently improved, and the gas barrier property is lowered, and thus the internal pressure of the tire is maintained. May cause sexual deterioration. In addition, the average particle diameter of the flexible resin (A2) in the thermoplastic resin film (A layer) is observed, for example, by freezing the sample, cutting the sample with a microtome, and observing with a transmission electron microscope (TEM).

  The content of the flexible resin (A2) in the thermoplastic resin film (A layer) is preferably in the range of 10 to 30% by mass. When the content of the flexible resin (A2) is less than 10% by mass, the effect of improving the bending resistance is small. On the other hand, when it exceeds −20% by mass, the gas permeability may be increased.

  The ethylene-vinyl alcohol copolymer-based resin is preferably a modified ethylene-vinyl alcohol copolymer obtained by, for example, reacting an ethylene compound with an ethylene-vinyl alcohol copolymer. Such a modified ethylene-vinyl alcohol copolymer has a low elastic modulus as compared with a normal ethylene-vinyl alcohol copolymer, so it has high fracture resistance at the time of layer bending and excellent crack resistance in a low temperature environment. Yes.

  The ethylene-vinyl alcohol copolymer preferably has an ethylene content of 25 to 50 mol%, more preferably -20 to 48 mol%, and still more preferably 35 to 45 mol%. If the ethylene content is less than 25 mol%, the bending resistance, fatigue resistance and melt moldability may be deteriorated. On the other hand, if it exceeds 50 mol%, the gas barrier properties may not be sufficiently secured. The ethylene-vinyl alcohol copolymer preferably has a saponification degree of 90% or more, more preferably 95% or more, and even more preferably 99% or more. If the degree of saponification is less than 90%, gas barrier properties and thermal stability during molding may be insufficient. Further, the ethylene-vinyl alcohol copolymer preferably has a melt flow rate (MFR) of 0.1 to 30 g / 10 min at 190 ° C. under a load of 2160 g, and 0.3 to 25 g / 10 min. More preferably.

  In the present invention, a method for producing the modified ethylene-vinyl alcohol copolymer is not particularly limited, but a production method in which the ethylene-vinyl alcohol copolymer and an epoxy compound are reacted in a solution is preferably exemplified. More specifically, a modified ethylene-vinyl alcohol copolymer is produced by adding an epoxy compound to a solution of an ethylene-vinyl alcohol copolymer in the presence of an acid catalyst or an alkali catalyst, preferably in the presence of an acid catalyst, and reacting. can do. Examples of the reaction solvent include aprotic polar solvents such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Examples of the acid catalyst include p-toluenesulfonic acid, methanesulfonic acid, trifluoromeckensulfonic acid, sulfuric acid, and boron trifluoride. Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, and lithium hydroxide. Sodium methoxide and the like. The catalyst amount is preferably in the range of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer.

  As the epoxy compound to be reacted with the ethylene-vinyl alcohol copolymer, a monovalent epoxy compound is preferable. A divalent or higher-valent epoxy compound may crosslink with the ethylene-vinyl alcohol copolymer to generate gels, blisters, and the like, thereby reducing the crystal quality of the layer including the thermoplastic resin film. Of the monovalent epoxy compounds, glycidol and epoxypropane are particularly preferred from the viewpoints of ease of production of the modified ethylene-vinyl alcohol copolymer, gas barrier properties, flex resistance, and fatigue resistance. Moreover, it is preferable that the said epoxy compound is made to react 1-50 mass parts with respect to 100 mass parts of ethylene-vinyl alcohol copolymers, It is still more preferable to react 2-40 mass parts, 5-35 mass parts It is more preferable to react.

  The modified ethylene-vinyl alcohol copolymer has a melt flow rate (MFR) of 190 ° C. and 0.130 g / 10 min under a load of 2160 g from the viewpoint of obtaining gas barrier properties, flex resistance and fatigue resistance. It is preferable that it is 0.3 to 25 g / 10 min, more preferably 0.5 to 20 g / 10 min.

  The thermoplastic resin film (A layer) is prepared by kneading a thermoplastic resin (A1) and a flexible resin (A2) to prepare a resin composition (A3), followed by melt molding, preferably a T-die method or an inflation method. The film can be formed into a film, a sheet or the like at a melting temperature of preferably 150 to 270 ° C. by extrusion molding. In addition, the thermoplastic resin film (A layer) may be a single layer or a multilayered layer as long as it includes a layer made of the resin composition (A3). Here, as a method of multilayering, a co-extrusion method and the like can be mentioned.

  In the laminated body of the present invention, it is preferable to further include one or more layers made of a thermoplastic urethane-based elastomer from the viewpoint of water resistance and adhesion to rubber. Here, the said thermoplastic urethane type elastomer is obtained by reaction of a polyol, an isocyanate compound, and a short chain diol. A polyol and a short chain diol form a linear polyurethane by an addition reaction with an isocyanate compound. The polyol becomes a flexible part in the thermoplastic urethane-based elastomer, and the isocyanate compound and the short-chain diol become a hard part. Note that the properties of thermoplastic urethane elastomers can be changed over a wide range by changing the type, blending amount, polymerization conditions, and the like of raw materials. Suitable examples of the thermoplastic urethane elastomer include polyether urethane.

In addition, the thermoplastic resin film (A layer) preferably has an oxygen permeability coefficient at 20 ° C. and 65% RH of 3.0 × 10 ⁻¹² cm ³ / cm ² · sec · cmHg or less, 1.0 It is more preferable that it is 10 × 10 ⁻¹² cm ³ / cm ² · sec · cmHg or less, and it is more preferable that it is 5.0 × 10 ⁻¹³ cm ³ / cm ² · sec · cmHg or less. When the oxygen permeability coefficient at 20 ° C. and 65% RH exceeds 3.0 × 20 ⁻¹² cm ³ / cm ² · sec · cmHg, when this thermoplastic resin film (A layer) is used as an inner liner, In order to enhance the internal pressure retention characteristics, the thermoplastic resin film (A layer) must be thickened, and the weight of the tire cannot be sufficiently reduced.

  Furthermore, the thermoplastic resin film (A layer) is preferably cross-linked. When the thermoplastic resin film (A layer) is not cross-linked, the laminate is significantly deformed and becomes non-uniform in the vulcanization process of the tire, and the gas barrier property, flex resistance, fatigue resistance of the thermoplastic resin film (A layer) Sexuality may worsen. Here, as a crosslinking method, a method of irradiating energy rays is preferable. Examples of the energy rays include ionizing radiation such as ultraviolet rays, electron beams, X-rays, α rays, γ rays, and among these, electron beams are used. Particularly preferred. The electron beam irradiation is preferably performed after the thermoplastic resin film (A layer) is processed into a molded body such as a film or sheet. Here, the dose of the electron beam is preferably in the range of 10 to 60 Mrad, and more preferably in the range of 20 to 50 Mrad. When the electron beam dose is less than 10 Mrad, the crosslinking is difficult to proceed. On the other hand, when the dose exceeds 60 Mrad, the molded body is likely to deteriorate. In addition, the thermoplastic resin film (A layer) may be subjected to a surface treatment by an oxidation method, a concavo-convex method or the like in order to improve the adhesiveness with the adhesive layer. 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. Is mentioned. Among these, corona discharge treatment is preferable.

≪Layer made of resin composition containing elastomer (B layer) ≫
The multilayer structure (a layer containing a thermoplastic resin film) preferably contains one or more layers (B layer) made of a resin composition further containing an elastomer from the viewpoint of water resistance and adhesion to rubber. As this elastomer, it is preferable to use a thermoplastic elastomer for melt molding.

Examples of the thermoplastic elastomer include polystyrene thermoplastic elastomers, polyolefin thermoplastic elastomers, polydiene thermoplastic elastomers, polyvinyl chloride thermoplastic elastomers, chlorinated polyethylene thermoplastic elastomers, polyurethane thermoplastic elastomers (hereinafter referred to as thermoplastic elastomers). , Sometimes referred to as “TPU”), at least one selected from the group consisting of polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and fluororesin-based thermoplastic elastomers. Among these, from the viewpoint of ease of molding, from the group consisting of polystyrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polydiene-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers and polyamide-based thermoplastic elastomers. At least one selected from the above is preferably used, and a polyurethane-based thermoplastic elastomer is more preferably used.
Here, the polyurethane-based thermoplastic elastomer is obtained by a reaction of a polyol, an isocyanate compound, and a short-chain diol. A polyol and a short chain diol form a linear polyurethane by an addition reaction with an isocyanate compound. The polyol becomes a flexible part in the thermoplastic urethane-based elastomer, and the isocyanate compound and the short-chain diol become a hard part. Note that the properties of thermoplastic urethane elastomers can be changed over a wide range by changing the type, blending amount, polymerization conditions, and the like of raw materials. Suitable examples of the thermoplastic urethane elastomer include polyether urethane.

≪Relationship between A layer and B layer≫
In the multilayer structure, the peel resistance between the A layer and the B layer was measured at 23 ° C. and 50% RH atmosphere at a tensile rate of 50 mm / min after heating at 180 ° C. for 15 minutes and in accordance with JIS-K6854. Is preferably 25 N / 25 mm or more, more preferably 27 N / 25 mm or more, still more preferably 30 N / 25 mm or more, and particularly preferably 50 N / 25 mm or more. Thus, the A layer and the B layer have very good interlayer adhesion.

  Regarding the interlayer relationship of the multilayer structure, it is considered that the cross-linking reaction between molecules occurs at the interface between the A layer and the B layer by irradiation of active energy rays, and it is considered that they are firmly bonded, and high interlayer adhesion is exhibited. Is done.

<Method for producing multilayer structure>
The method for producing the multilayer structure is not particularly limited as long as the A layer and the B layer are laminated and bonded satisfactorily. For example, known methods such as co-extrusion, bonding, coating, bonding, and adhesion are known. This method can be adopted. Specifically, the method for producing the multilayer structure includes (1) using a resin composition for forming an A layer and a resin composition for forming a B layer, and having the A layer and the B layer by a multilayer coextrusion method. A method for producing a multilayer structure, and (2) using a resin composition for forming an A layer and a resin composition for forming a B layer, by laminating and stretching a plurality of laminates via an adhesive. Examples thereof include a method for producing a multilayer structure having an A layer and a B layer. Among these, from the viewpoint of high productivity and excellent interlayer adhesion, there is a method of molding by a multilayer coextrusion method using the resin composition for forming the A layer and the resin composition for forming the B layer of (1). preferable.

  In the multilayer coextrusion method, the resin composition for forming the A layer and the resin composition for forming the B layer are heated and melted, supplied from different extruders or pumps to the extrusion dies through the respective flow paths, and extruded. The multilayer structure is formed by laminating and bonding after being extruded into multiple layers from the die. As this extrusion die, for example, a multi-manifold die, a field block, a static mixer, or the like can be used.

  In the multilayer structure, the multilayer laminate obtained in this manner is irradiated with active energy rays as described above to promote the crosslinking reaction and further improve the interlayer adhesion between the A layer and the B layer. It is preferable to make it. Since the multilayer structure is thus irradiated with the active energy rays, the adhesion between the layers is enhanced, and as a result, the gas barrier property and the bending resistance can be improved.

  The active energy rays are those having energy quanta among electromagnetic waves or charged particle beams, specifically, ultraviolet rays, γ rays, electron beams and the like. Among these active energy rays, an electron beam is preferable from the viewpoint of improving the interlayer adhesion. By using an electron beam as the active energy ray, the interlayer cross-linking reaction is further promoted, and the interlayer adhesion of the multilayer structure can be further improved.

  When irradiating an electron beam, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type are used as an electron beam source. It is preferable to irradiate within an irradiation dose range of 5 to 600 kGy with a normal acceleration voltage of 100 to 500 kV.

  Moreover, when using an ultraviolet-ray as an active energy ray, it is good to irradiate what contains the ultraviolet-ray with a wavelength of 190-380 nm. The ultraviolet light source is not particularly limited, and for example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, or the like is used.

  As described above, this multilayer structure has excellent interlayer adhesion, and has high gas barrier properties, stretchability, thermoformability, and durability.

  This multilayer structure is not limited to the above embodiment. For example, other layers may be included in addition to the A layer and the B layer. Although the kind of resin composition which comprises this other layer is not specifically limited, A thing with high adhesiveness between A layer and / or B layer is preferable. The other layer has a molecular chain having a functional group that reacts with a hydroxyl group possessed by, for example, EVOH in the A layer, or a carbamate group or an isocyanate group in the molecular chain of, for example, TPU in the B layer. Those that are particularly preferred.

<Rubber layer>
The material of this rubber layer contains a modified diene polymer. Here, the modified diene polymer refers to a diene polymer modified with a polar functional group.
The polar functional group is a functional group containing an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, or a tin atom, specifically, an epoxy group, an amino group, an imino group, a nitrile group, an ammonium group, or an isocyanate group. , Imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, oxycarbonyl group, sulfide group, disulfide group, sulfonyl group, sulfinyl group, thiocarbonyl group, nitrogen-containing heterocyclic group , Oxygen-containing heterocyclic groups, alkoxysilyl groups, and tin-containing groups. Epoxy groups and isocyanate groups are particularly preferable.
Moreover, it is preferable that the material of this rubber layer includes a softening agent described later. By adjusting the content of the softener in the rubber layer, the dynamic storage elastic modulus E ₂ ′ at −20 ° C. of the rubber layer 7 can be adjusted.

The dynamic storage elastic modulus E ₂ ′ at −20 ° C. of this rubber layer is preferably 1.0 × 10 ^{5 to} 1.0 × 10 ⁸ Pa, more preferably 1.0 × 10 ^{5 to} 1.0. × a 10 ⁷ Pa, more preferably from ^{1.0 × 10 5 ~5.0 × 10 5} Pa. When it is 1.0 × 10 ⁵ Pa or more, it is preferable in that the workability of rubber kneading can be sufficiently secured and the gauge can be reduced to a range of 0.1 to 1 mm. When it is 1.0 × 10 ⁸ Pa or less, the elasticity of the rubber layer itself in the low temperature environment is improved, the deformation of the carcass can be reduced, the deformation of the thermoplastic resin film is suppressed, and the crack resistance in the low temperature environment is achieved. improves.
In the present invention, the dynamic storage elastic modulus E ₂ ′ at −20 ° C. means a value after heat vulcanization, that is, a value after a pneumatic tire is manufactured using a laminate.

≪Modified diene polymer≫
Examples of the modified diene polymer include modified natural rubber (modified NR) and / or modified synthetic rubber. Examples of the modified synthetic rubber include modified polyisoprene rubber (modified IR), modified polybutadiene rubber (modified BR), modified styrene-butadiene copolymer (modified SBR), and modified styrene-isoprene copolymer (modified SIR). . These modified natural rubber and modified synthetic rubber are excellent in durability in a low temperature environment.

The adhesive layer preferably contains two or more modified diene polymers having different modification rates. Thereby, the adhesiveness with a carcass can be improved with a modified diene polymer having a low modification rate, and the adhesiveness with a thermoplastic resin film can be improved with a modified diene polymer with a high modification rate.
In the present invention, the “modification rate” means the ratio (mol%) of the number of modified double bonds to the total number of double bonds in the diene polymer before modification.

The glass transition temperature (Tg) of this modified diene polymer is preferably 0 ° C. or lower, more preferably −20 ° C. or lower, still more preferably −20 ° C. or lower, particularly preferably −50 ° C. or lower. is there. When the glass transition temperature (Tg) is 0 ° C. or lower, the embrittlement temperature can be sufficiently lowered, and the low temperature durability can be sufficiently ensured.
The glass transition temperature (Tg) is a value measured by the following method. That is, using a differential scanning calorimeter (DSC) “RDC220” manufactured by Seiko Co., Ltd., the temperature is measured at 15 ° C./min after cooling to −150 ° C. Before and after the jump of the DSC curve, a tangent to the base line is drawn, and the temperature at the midpoint between the two tangents is read and defined as Tg.
As the modified diene polymer, an epoxy-modified diene polymer is preferably used. Among the epoxy-modified diene polymers, one or more selected from epoxidized natural rubber, epoxidized butadiene rubber, and epoxidized polyisoprene rubber are preferably used.

(Epoxidized natural rubber (ENR))
As the modified diene polymer, epoxidized natural rubber (hereinafter sometimes abbreviated as “ENR”) is preferably used.
As the epoxidized natural rubber (ENR), commercially available epoxidized natural rubber may be used, or natural rubber may be epoxidized. The method for epoxidizing natural rubber is not particularly limited, and can be carried out using a method such as a chlorohydrin method, a direct oxidation method, a hydrogen peroxide method, an alkyl hydroperoxide method, or a peracid method. Examples of the peracid method include a method of reacting natural rubber with an organic peracid such as peracetic acid or performic acid. This reaction epoxidizes the double bond present in the natural rubber molecule, and this structure is revealed from proton nuclear magnetic resonance spectrum (NMR) and infrared absorption spectrum (IR). Moreover, content of an epoxy group is measured from NMR.
This epoxidized natural rubber has less air permeability than natural rubber, and the air permeability tends to be greatly reduced.

The epoxidized natural rubber (ENR) preferably contains at least two types of ENRs having different epoxidation rates. As a result, in the bonding of the resin film layer and the rubber-like elastic layer, the adhesion with the rubber-like elastic layer is improved with an ENR having a low degree of epoxidation, and the adhesion with the resin film layer is improved with an ENR having a high epoxidation rate. Can be made.
Here, the epoxidation rate A mol% means that A% of double bonds in natural rubber is epoxidized.
In the present invention, the epoxidation rate means the ratio (mol%) of the number of epoxidized double bonds to the total number of double bonds in the rubber before epoxidation, and measured by the following method, for example. it can. That is, ENR is dissolved in deuterated chloroform, and the integrated value h of the carbon-carbon double bond portion and the aliphatic portion is determined by nuclear magnetic resonance (NMR (JNM-ECA series manufactured by JEOL Ltd.)) spectroscopic analysis. It can be calculated from the ratio of (ppm) using the following calculation formula. The same applies hereinafter.
(Epoxidation rate) = 3 × h (2.69) / (3 × h (2.69) + 3 × h (5.14) + h (0.87)) × 100

  As ENRs having different epoxidation rates, a combination of at least two types of (a) ENR having an epoxidation rate of 5 to 30 mol% and (b) ENR having an epoxidation rate of 40 to 90 mol% is preferable. The content of the ENR combination is preferably 80 to 100% by mass. If the content of the ENR combination in the rubber layer is in the range of 80 to 100% by mass, the compatibility of the components in the rubber layer is improved, and the adhesive strength and durability of the rubber layer are improved. From such a viewpoint, the content of the ENR combination is more preferably 90 to 100% by mass, and most preferably 100% by mass.

Further, by using ENR having an epoxidation rate of 5 to 30 mol% as an ENR having a low epoxidation rate, the properties of natural rubber are maintained, and the dynamic storage elastic modulus E ₂ ′ of the rubber layer at −20 ° C. Can be suppressed, and the occurrence of cracks in a low temperature environment can be prevented. By using ENR having an epoxidation rate of 40 to 90 mol% as a natural rubber having a high epoxidation rate, it makes use of the properties of ENR and acts with a functional group in the thermoplastic resin film, thereby providing a gas barrier property of the resulting laminate. Can be improved.
In the present invention, the content ratio of the low epoxidation rate ENR and the high epoxidation rate ENR is 20:80 to 80:20 in terms of mass ratio from the viewpoint of the balance of the respective effects described above. It is preferable that it is the range of these.

(Epoxidized butadiene rubber (EBR))
As the modified diene polymer, an epoxidized butadiene rubber (hereinafter sometimes abbreviated as “EBR”) is also preferably used.
The epoxidized butadiene rubber (EBR) is not particularly limited, and may be a commercially available epoxidized butadiene rubber or an epoxidized butadiene rubber (BR). The method for epoxidizing butadiene rubber is not particularly limited, and examples thereof include a chlorohydrin method, a direct oxidation method, a hydrogen peroxide method, an alkyl hydroperoxide method, and a peracid method. Examples of the peracid method include a method of reacting butadiene rubber with an organic peracid such as peracetic acid or performic acid. This reaction epoxidizes the double bonds present in the butadiene rubber molecule, and this structure is revealed from proton nuclear magnetic resonance spectra (NMR) and infrared absorption spectra (IR). Moreover, content of an epoxy group is measured from NMR. It should be noted that epoxidized butadiene rubbers having various epoxidation rates can be prepared by adjusting the amount of organic peracid and the reaction time.
This epoxidized butadiene rubber has less air permeability than butadiene rubber, and the air permeability tends to be greatly reduced.

  The epoxidation rate of the epoxidized butadiene rubber (EBR) is preferably 5 mol% or more, and more preferably 10 mol% or more. When the epoxidation rate is less than 5 mol%, sufficient adhesion to the thermoplastic resin film tends not to be obtained. The epoxidation rate is preferably 90 mol% or less, more preferably 75 mol% or less, and still more preferably 60 mol% or less. When the epoxidation rate exceeds 90 mol%, the elastic modulus at −20 ° C. tends to increase and the low temperature cracking property tends to decrease.

  The epoxidized butadiene rubber (EBR) is not particularly limited. For example, BR1220 manufactured by Nippon Zeon Co., Ltd., BR130B manufactured by Ube Industries, Ltd., BR150B and other high cis content BR, Ube Industries, Ltd. BR containing a syndiotactic polybutadiene crystal such as VCR412 and VCR617 manufactured by the same company can be used.

  The epoxidized butadiene rubber (EBR) preferably contains at least two types of EBR having different epoxidation rates. Thereby, when joining a laminated body with the rubber-like elastic body layer for carcass at the time of tire manufacture mentioned below, the adhesiveness with a rubber-like elastic body layer can be improved by EBR with a low degree of epoxidation, Adhesiveness with a layer containing a resin film can be improved with ENR having a high epoxidation rate.

  As the EBR having different epoxidation rates, a combination of at least two types of (a) EBR having an epoxidation rate of 5 to 30 mol% and (b) EBR having an epoxidation rate of 40 to 90 mol% is preferable. It is preferable that content of the said EBR combination is 80-100 mass%. If the content of the EBR combination in the rubber layer is in the range of 80 to 100% by mass, the compatibility of the components in the rubber layer is improved, and the adhesive strength and durability of the rubber layer are improved. From such a viewpoint, the content of the EBR combination is more preferably 90 to 100% by mass, and most preferably 100% by mass.

Also, by using EBR with an epoxidation rate of 5 to 30 mol% as an EBR with a low epoxidation rate, the properties of butadiene rubber are maintained, and the dynamic storage elastic modulus E ₂ ′ at −20 ° C. of the rubber layer is increased. Can be suppressed, and the occurrence of cracks in a low temperature environment can be prevented. By using EBR having an epoxidation rate of 40 to 90 mol% as a butadiene rubber having a high epoxidation rate, it makes use of the properties of EBR and acts with a functional group in the thermoplastic resin film, thereby providing a gas barrier property of the resulting laminate. Can be improved.
In the present invention, the content ratio of the low epoxidation rate EBR and the high epoxidation rate EBR is 20:80 to 80:20 in terms of mass ratio from the viewpoint of the balance of the respective effects described above. It is preferable that it is the range of these.

(High diene elastomer)
As the modified diene polymer, in addition to the ENR, the high diene elastomer can be contained in a proportion of preferably 20% by mass or less, more preferably 10% by mass or less, but most preferably not.
Examples of the high diene elastomer include natural rubber, synthetic isoprene rubber (IR), cis 1,4-polybutadiene rubber (BR), syndiotactic-1,2-polybutadiene rubber (1, BR), and styrene-butadiene rubber ( SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR) and the like.
These high diene elastomers may be used singly or in combination of two or more, among which natural rubber, synthetic isoprene rubber (IR) and cis 1,4-polybutadiene rubber (BR) is preferred.

≪Softening agent≫
In order to adjust the dynamic storage elastic modulus E ₂ ′ at −20 ° C. of the rubber layer, it is preferable to contain a softening agent. That is, when the modification rate of the diene polymer is increased in order to improve the adhesion of the adhesive layer, the dynamic storage elastic modulus E ₂ ′ tends to increase. However, by adding a softening agent, the dynamic storage elasticity is increased. The rate E ₂ 'can be reduced to a desired value.

As the softener, any of mineral oil softeners, vegetable oil softeners, and synthetic softeners can be used. Mineral oil softeners include petroleum softeners and coal tar softeners. Examples of petroleum softeners include process oil, extender oil, asphalt, paraffins, liquid paraffin, petroleum jelly, and petroleum resin. Examples of the coal tar softener include coal tar and coumarone indene resin.
As vegetable oil softeners, fatty oil softeners such as soybean oil, palm oil, pine oil, castor oil, linseed oil, rapeseed oil, coconut oil, tall oil, waxes such as factis, beeswax, carnauba wax, lanolin, Examples include fatty acids such as linoleic acid, palmitic acid, stearic acid, and lauric acid.
Synthetic softeners include synthetic resin softeners, liquid rubbers or oligomers, low molecular plasticizers, high molecular plasticizers, and reactive plasticizers.
Examples of the synthetic resin softener include phenol aldehyde resin, styrene resin, and atactic polypropylene. Examples of the liquid rubber or oligomer include polybutene, liquid butadiene rubber, liquid isoprene rubber, and liquid acrylonitrile butadiene rubber. Examples of the low molecular plasticizer include dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, and the like.

  The content of the softening agent is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, and still more preferably 10 to 20 parts by mass with respect to 100 parts by mass of all rubber components constituting the rubber layer. Part. When the amount is 1 part by mass or more, the modification rate of the modified diene polymer can be sufficiently increased. It is prevented that a rubber layer is too soft as it is 30 mass parts or less. As the softening agent, one selected from the softening agents described above can be used, or a plurality of softening agents can be used in combination.

≪Vulcanizing agent, vulcanization accelerator≫
The rubber layer can contain a vulcanizing agent, or a vulcanizing agent and a vulcanization accelerator, in order to impart vulcanizability.
As said vulcanizing agent, sulfur etc. are mentioned, The usage-amount is 0.1-10 mass parts as a sulfur content with respect to 100 mass parts of all the rubber components, More preferably, it is 1.0-5 mass parts. It is.
The vulcanization accelerator that can be used in the present invention is not particularly limited. For example, M (2-mercaptobenzothiazole), DM (dibenzothiazolyl disulfide), CZ (N-cyclohexyl-2-benzothia). Zolylsulfenamide) and other guanidine vulcanization accelerators such as DPG (diphenylguanidine) can be used, and the amount used is 0.1 to 5 with respect to 100 parts by mass of the rubber component. A mass part is preferable, More preferably, it is 0.2-3 mass part.

≪Optional ingredient≫
The rubber layer can contain a filler, a tackifier resin, stearic acid, zinc white, an anti-aging agent, and the like, if necessary, in addition to the above components.
(Filler)
As the filler, an inorganic filler and / or carbon black is used. The inorganic filler is not particularly limited, and preferred examples include silica, aluminum hydroxide, aluminum oxide, magnesium oxide, montmorillonite, mica, smectite, organic montmorillonite, organic mica, and organic smectite by a wet method. . These may be used individually by 1 type, and may be used in combination of 2 or more types.
On the other hand, as carbon black, any of those conventionally used as reinforcing fillers for rubber can be appropriately selected and used, for example, FEF, SRF, HAF, ISAF, SAF, GPF, etc. Is mentioned.
The content of the filler is preferably 5 parts by mass or more of the inorganic filler together with carbon black from the viewpoint of tackiness and peeling resistance per 100 parts by mass of the modified diene polymer.

(Tackifying resin)
Examples of the tackifying resin having a function of imparting tackiness to the rubber layer include phenolic resins, terpene resins, modified terpene resins, hydrogenated terpene resins, rosin resins, C5, C9 petroleum resins, xylene resins, Coumarone-indene resin, dicyclopentadiene resin, styrene resin and the like can be mentioned. Among these, phenol resin, terpene resin, modified terpene resin, hydrogenated terpene resin and rosin resin are preferable.
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. Further, as terpene resins, modified terpene resins, and hydrogenated terpene resins, for example, terpene resins such as β-pinene resin and α-pinene resin, hydrogenated terpene resins obtained by hydrogenation of these, terpenes and the like Examples thereof include modified terpene resins obtained by reacting phenol with a Friedel-Craft type catalyst or condensing with formaldehyde. Examples of rosin resins include natural resin rosin and rosin derivatives modified by hydrogenation, disproportionation, dimerization, esterification, limeization, and the like.
These resins may be used alone or in combination of two or more. Among these resins, phenolic resins are particularly preferable.
This tackifying resin is preferably used in an amount of 5 parts by mass or more, more preferably 5 to 40 parts by mass, and still more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the modified diene polymer.

The rubber layer can be prepared by mixing the components described above using, for example, a Banbury mixer or a roll.
The adhesive layer of the present invention thus obtained is used for joining the thermoplastic resin film and the carcass.

≪Rubber layer thickness≫
The rubber layer has a thickness of 0.1 to 30 mm, preferably 0.1 to 2 mm, more preferably 0.1 to 1 mm, and still more preferably 0.1 to 0.4 mm. When the thickness is 0.1 mm or more, the thermoplastic resin film and the carcass can be firmly bonded, and the function of improving crack resistance in a low-temperature environment is satisfactorily exhibited. When it is 30 mm or less, the weight reduction of a pneumatic tire is achieved.

[Manufacturing method of laminate]
Although there is no restriction | limiting in particular in the manufacturing method of this laminated body, The method using the sheet | seat of the rubber layer shown next, and the method using the coating liquid of the composition of a rubber layer are employ | adopted suitably.

<Method of using rubber layer sheet>
In this method, a layer containing a thermoplastic resin film is prepared in advance. Also, a rubber layer sheet is prepared in advance using an extruder or the like. Next, a rubber layer sheet is attached to the surface of the layer containing the thermoplastic resin film. At this time, the sheet of the rubber layer has adhesiveness because it contains the modified diene polymer, and is firmly adhered to the layer including the thermoplastic resin film.

<Method of Using Coating Solution for Rubber Layer Composition>
In this method, a layer containing a thermoplastic resin film is prepared in advance, and an adhesive coating solution obtained by dissolving the rubber layer composition in a good solvent is applied to the surface.
As the good solvent, an organic solvent having a Hilderand solubility parameter δ value in the range of 14 to 20 MPa ^1/2 as 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 handling properties, but is usually in the range of 5 to 50% by mass, preferably 10 to 30% by mass. It is.

[Pneumatic tire manufacturing method]
The method for producing a pneumatic tire according to the present invention is such that the laminated body is wound around a tire molding drum so that the rubber layer is on the outside, and further a tire member is wound, and then the molding drum is pulled out to obtain a green tire. The green tire is heated and vulcanized to form a pneumatic tire.
For convenience of explanation, the structure of the pneumatic tire will be described, and then the details of the method for manufacturing the pneumatic tire will be described.

<Pneumatic tire structure>
FIG. 4 is a partial cross-sectional view showing an example of the pneumatic tire 9 along the tread width direction and the tire radial direction.
The pneumatic tire 9 includes a bead core 1, a carcass 2 wound around the bead core 1, an inner liner 3 disposed inside the carcass 2 in the tire radial direction, and a tire radial direction of a crown portion of the carcass 2. The belt portion includes two belt layers 4 disposed on the outer side, and a tread portion 5 and a sidewall portion 6 disposed on the outer side in the tire radial direction of the belt portion.
The inner liner 3 is made of the laminate 10.

<Pneumatic tire manufacturing method>
Next, a method for manufacturing the pneumatic tire 9 will be described.
First, as described above (see FIGS. 1 to 3), the layer 10 (inner liner 3) is provided on the circumferential surface of the tire molding drum 20 and includes a thermoplastic resin film with respect to the outer circumferential surface of the tire molding drum 20. Wrap so that 11 faces. As shown in FIG. 3, after this winding, the laminate 10 (inner liner 3) is overlapped by the surface of the layer 11 including the thermoplastic resin film in the vicinity of the left end portion 10a and the surface of the rubber layer 12 in the vicinity of the right end portion 10b. A mating portion is formed.
Next, a rubber member constituting the carcass 2 is wound on the laminate 10 (inner liner 3), and further a rubber member constituting the belt layer 4, a rubber member constituting the tread portion 5, and a sidewall portion 6 are provided thereon. After the constituent rubber members and the like are wound up, the drum is pulled out to obtain a green tire.
A pneumatic tire 9 is obtained by heating and vulcanizing the green tire at a temperature of usually 120 ° C. or higher, preferably 125 to 200 ° C., more preferably 130 to 180 ° C.

  According to this method for producing a pneumatic tire, as described above, since the rubber layer contains the modified diene polymer, it has excellent adhesiveness with the layer containing the thermoplastic resin film, and the end of the laminate formed by the winding described above. Excellent adhesion of overlapping parts. This reliably prevents peeling at the overlapping portion. In addition, since the adhesiveness of the overlapping portion is excellent as described above, it is not necessary to make the laminate into a cylindrical shape without the overlapping portion as in Patent Document 2, and an increase in inventory management cost and a decrease in production efficiency are prevented. Is done. Further, since an edge adhesive layer for adhering the overlapping portion as in Patent Document 3 is not required, the number of parts is reduced by that amount, and the edge adhesive layer is transferred and laminated. This eliminates the hassle of working and is excellent in workability. Moreover, since it is not necessary to shift and laminate each layer in the laminated body as in Patent Document 4, it does not take time to carry out the laminating work, and is excellent in workability on winding on a forming drum.

≪Carcass 2≫
The carcass 2 is composed of one or two or more carcass plies. The carcass ply has a structure in which fibers such as polyester are wrapped in a coating rubber.
The material for the coating rubber is not particularly limited, and for example, a diene rubber is used. Specific examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), cis-1,4-polybutadiene rubber (BR), and syndiotactic-1,2-polybutadiene rubber (1,2BR). ), Styrene-butadiene copolymer rubber (SBR), and the like. These diene rubbers may be used alone or in combination of two or more.

  For coating rubber, in addition to the above rubber components, compounding agents commonly used in the rubber industry, such as reinforcing fillers, softeners, anti-aging agents, vulcanizing agents, vulcanization accelerators for rubber, scorch inhibiting agents , Zinc white, stearic acid and the like can be appropriately blended according to the purpose. As these compounding agents, commercially available products can be suitably used.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The measurement method and evaluation method for each characteristic will be described first.

[Measurement method and evaluation method of each characteristic]
(1) Dynamic storage elastic modulus E ′ at −20 ° C.
For each sample (dimensions: width 5 mm, length 40 mm), using a spectrometer manufactured by Ueshima Seisakusho Co., Ltd., under the conditions of an initial strain of 10%, a dynamic strain of 0.1%, a frequency of 15 Hz, and −20 ° C. The storage elastic modulus E ′ was measured.

(2) Tg
Using a differential scanning calorimeter (DSC) “RDC220” manufactured by Seiko Co., Ltd., the temperature was measured at 15 ° C./min after cooling to −150 ° C. Before and after the jump of the DSC curve, a tangent to the base line was drawn, and the temperature at the midpoint between the two tangents was read and taken as Tg.

(3) Epoxidation rate of epoxy-modified diene polymer Epoxidized butadiene rubber (EBR) was dissolved in deuterated chloroform and analyzed by nuclear magnetic resonance (NMR (JNM-ECA series manufactured by JEOL Ltd.)) spectroscopic analysis. The epoxidation rate was calculated from the ratio of the integral value h (ppm) of the carbon-carbon double bond part and the aliphatic part using the following calculation formula.
(Epoxidation rate E%) = 3 × h (2.69) / (3 × h (2.69) + 3 × h (5.14) + h (0.87)) × 100

(4) Gas barrier properties 5 layer film and 21 layer film, which will be described later, are conditioned for 5 days at 20 ° C.-65% RH, and two samples of conditioned 3 layer film and 7 layer film are used. Using a “MOCON OX-TRAN 2/20 type” manufactured by Control Co., the oxygen transmission rate was measured according to the method described in JIS-K7126 (isobaric method) under 20 ° C.-65% RH condition. The average value was obtained (unit: mL / m ² · day · atm), and the average value of Comparative Example 1 was displayed as an index to evaluate gas barrier properties. The lower the index value, the better the gas barrier property.

(5) Interlaminar peel resistance After the laminate was heated at 160 ° C. for 20 minutes, the interlaminar peel resistance was measured according to JIS-K6854 in a T-type peel test under a 23 ° C., 50% H atmosphere and a pulling speed of 50 mm / min. Was measured.

(6) Presence or absence of cracks after drum running test The tire was run at 1,000 km by pressing it on a drum with an air pressure of 140 kPa and a rotational speed corresponding to a speed of 80 km / h with a load of 6 kN in an atmosphere of −20 ° C. did. The appearance of the inner liner of the tire after running the drum was visually observed to evaluate the presence or absence of cracks.

(7) Gas barrier property of the tire after the drum running test The tire side surface part is cut out to a size of 10 cm × 10 cm, conditioned at 20 ° C.-65% RH for 5 days, and a sample of the section of the conditioned tire side part is prepared. Using 2 sheets, using “MOCON OX-TRAN 2/20 type” manufactured by Modern Control Co., under the conditions of 20 ° C.-65% RH, the oxygen transmission rate is adjusted according to the method described in JIS-K7126 (isobaric method). The average value was measured (unit: mL / m ² · day · atm), and the average value of the oxygen permeation rate of the sample of the laminate of Comparative Example 1 was displayed as an index to evaluate gas barrier properties. The lower the index value, the better the gas barrier property.

(8) Characteristics of ethylene-vinyl alcohol copolymer (EVOH) The ethylene content and saponification degree of EVOH were measured by ¹ H-NMR measurement using deuterated dimethyl sulfoxide as a solvent [“JNM-GX-” manufactured by JEOL Ltd. The value calculated from the spectrum obtained in [Use 500 type] was used.
Further, the melt flow rate (MFR) of EVOH was measured by filling a sample into a cylinder having an inner diameter of 9.55 mm and a length of 162 mm of a melt indexer L244 [manufactured by Takara Kogyo Co., Ltd.], melting at 190 ° C., and weighing 2160 g. The load was evenly applied using a plunger with a diameter of 9.48 mm, and the amount was calculated from the amount of resin (g / 10 minutes) extruded per unit time from an orifice with a diameter of 2.1 mm provided at the center of the cylinder. However, when the melting point of EVOH is around 190 ° C or exceeds 190 ° C, it is measured at a plurality of temperatures above the melting point under a load of 2160g, and the inverse of absolute temperature is plotted on the horizontal axis and the logarithm of MFR is plotted on the vertical axis in a semilogarithmic graph. The value calculated by plotting and extrapolating to 190 ° C. was taken as the melt flow rate (MFR).

[Production Example 1] Production of a layer containing a thermoplastic resin film (5-layer film) EVOH [Kuraray Co., Ltd. "E105"] and thermoplastic polyurethane (TPU) [Kuraray Co., Ltd. Kuraray 3190] Was used, and a film layer (TPU layer / EVOH layer / TPU layer / EVOH layer / TPU layer) having a five-layer structure was produced under the following coextrusion molding conditions using a two-type five-layer coextrusion apparatus. The thickness of each layer is 2 μm / 20 μm / 2 μm / 20 μm / 10 μm, respectively.

Extrusion temperature of each resin: C1 / C2 / C3 / die = 170/170/170/220/220/220 ° C.
Extruder specifications for each resin:
TPU: 25mmφ Extruder “P25-18AC” [Osaka Seiki Machine Co., Ltd.]
EVOH: 20 mmφ Extruder Lab Machine ME Type “CO-EXT” [Toyo Seiki Co., Ltd.]
T-die specification: 500mm width, 2 types, 5 layers [Plastic Engineering Laboratory Co., Ltd.
Cooling roll temperature: 50 ° C
Take-off speed: 4 m / min The gas barrier property of this inner liner was measured by the above measuring method. The results are shown in Table 1.

[Production Example 2] Production of a layer containing a thermoplastic resin film (21-layer film) EVOH [Kuraray Co., Ltd. “E105”] and thermoplastic polyurethane (TPU) [Kuraray Co., Ltd. “Kuramylon 3190”] And a 21-layer film layer (TPU layer / EVOH layer ... EVOH layer / TPU layer. TPU layer: 11 layers, EVOH layer: 10 layers). The thickness of each layer is 2 μm for the TPU layer and 1 μm for the modified EVOH layer.

A multilayer film of 21 layers was extruded at a feed block temperature of 210 ° C. and a die of 208 ° C. for a multilayer.
Extruder specifications for each resin:
Thermoplastic polyurethane: 25mmφ extruder “P25-18AC” [manufactured by Osaka Seiki Co., Ltd.]
EVOH: 20 mmφ Extruder Lab Machine ME Type “CO-EXT” [Toyo Seiki Co., Ltd.]
T-die specification: 500mm width 2 types 21 layers [Plastic Engineering Laboratory Co., Ltd.]
Cooling roll temperature: 50 ° C
Take-off speed: 4 m / min For this inner liner, the gas barrier product was measured by the measurement method described above. The results are shown in Table 1.

[Production Example 3] Production of Epoxidized Butadiene Rubber (EBR (1)) 100 g of BR-150B (Hisys BR manufactured by Ube Industries Co., Ltd.) is finely cut so that one grain is about 0.5 g. The solution was added to 1200 ml of toluene in a 5 L container and dissolved with stirring for 24 hours. Next, 2 ml of formic acid was added and the temperature was raised to 50 ° C. on a water bath. While stirring the solution, 60 g of 30% by mass hydrogen peroxide was added dropwise over 30 minutes. After completion of the dropping, stirring was continued while maintaining 50 ° C., and 5 hours later, 0.3 g of BHT (dibutylhydroxytoluene) was added. After cooling to room temperature, the reaction solution was added to 5 L of methanol to precipitate the rubber component. The precipitate was spread on a wide vat and air-dried for 24 hours, followed by vacuum drying to obtain 99 g of EBR (1). As a result of calculating the epoxidation rate of this EBR (1) by the said method, it was 23.2 mol%.

[Production Example 4] Production of Epoxidized Butadiene Rubber (EBR (2)) 100 g of BR-150B (Hisys BR manufactured by Ube Industries Co., Ltd.) is finely cut so that one grain is about 0.5 g. The solution was added to 1200 ml of toluene in a 5 L container and dissolved with stirring for 24 hours. Next, 6 ml of formic acid was added and the temperature was raised to 50 ° C. on a water bath. While stirring the solution, 130 g of a hydrogen peroxide solution having a concentration of 30% by mass was added dropwise over 30 minutes. After completion of dropping, stirring was continued while maintaining 50 ° C., and after 7 hours, 0.3 g of BHT was added. After cooling to room temperature, the reaction solution was added to 5 L of methanol to precipitate the rubber component. The precipitate was spread on a wide vat and air-dried for 24 hours, followed by vacuum drying to obtain 99 g of EBR (2). As a result of calculating the epoxidation rate of this EBR (2) by the said method, it was 48.5 mol%.

[Production Example 5] Production of rubber sheet having no adhesiveness A rubber composition having the following composition was prepared, and a rubber sheet (thickness: 0.4 mm) was produced using an extruder.

(Rubber composition)
Natural rubber ... 50 parts by mass SBR [manufactured by JSR, SBR1712] ... 68.75 parts by mass GPF N-660 (carbon black) [Asahi Carbon Co., Ltd., 50S] ... 43 parts by mass Softener [TOP, large Hachi Chemical Industry Co., Ltd.] ... 3 parts by mass Aging inhibitor [Nocrac224-S, Ouchi Shinsei Chemical Co., Ltd.] ... 1.5 parts by mass Stearic acid [Asahi Denka Kogyo Co., Ltd.] ... 1. 5 parts by mass Vulcanization accelerator [Accel M, manufactured by Kawaguchi Chemical Industry Co., Ltd.] ... 0.5 part by mass Vulcanization accelerator [Accel CZ, manufactured by Kawaguchi Chemical Industry Co., Ltd.] ... 1 part by mass Zinc oxide [Hitec Corporation Made] ... 4 parts by mass Sulfur [manufactured by Karuizawa Refinery] ... 2.66 parts by mass

[Examples 1 to 4]
(1) Preparation of rubber layer The components of the types and amounts shown in Table 1 were kneaded according to a conventional method, and a rubber layer was prepared by molding into a sheet having a thickness of 400 µm using an extruder.
Further, a part of the rubber layer was used and heated and vulcanized at 160 ° C. for 20 minutes to obtain a vulcanized rubber layer. This vulcanized rubber layer at the measuring method, to measure the dynamic storage modulus E ₂ 'and Tg at -20 ° C.. The results are shown in Table 1.
(2) Production of Laminate Using the electron beam irradiation apparatus “Curetron EBC200-100 for Production” manufactured by Nissin High Voltage Co., Ltd., the rubber layer is pasted on one side of the 5-layer film obtained in Production Example 2. The laminated body was produced.
Moreover, according to the method mentioned above, the peeling resistance between the layers in the laminated body after vulcanization was measured. The results are shown in Table 1.

(3) Production of tire The laminate was wound on a tire molding drum so that the layer containing the thermoplastic resin film faced the drum. Next, a carcass was wound on the laminate, and a belt layer, a tread rubber member, and a sidewall rubber member were sequentially wound, and then the drum was pulled out to obtain a green tire.
This green tire was heated and vulcanized to produce a pneumatic tire (195 / 65R15) as shown in FIG.
About the obtained tire, the presence or absence of the crack after a drum running test and the gas barrier property of the tire after a drum running test were measured with the said measuring method. The results are shown in Table 1.

[Comparative Examples 1-2]
(1) Preparation of Rubber Layer A rubber layer was prepared in the same manner as in Example 1 except that the thickness was 400 μm and that the components in Table 1 were used as the components of the rubber layer. Further, in the same manner as in Example 1, the dynamic storage elastic modulus E ₂ ′ and Tg at −20 ° C. of the vulcanized rubber layer were measured. The results are shown in Table 1.
(2) Production of Laminate Using the electron beam irradiation apparatus “Curetron EBC200-100 for Production” manufactured by Nissin High Voltage Co., Ltd., the rubber layer is pasted on one side of the three-layer film obtained in Production Example 2. And a rubber sheet having no adhesiveness obtained in Production Example 8 was bonded thereon to produce a laminate.
Moreover, according to the method mentioned above, the peeling resistance between the layers in the laminated body after vulcanization was measured. The results are shown in Table 1.

(3) Production of Tire A pneumatic tire (195 / 65R15) as shown in FIG. 4 was produced in the same manner as in Example 1, and the presence or absence of cracks after the drum running test, and the gas barrier of the tire after the drum running test. Sex was measured. The results are shown in Table 1.

[note]
1) ENR25: Epoxidized natural rubber (trade name: ENR25, manufactured by RRIM) (epoxidation degree (epoxidation rate): 25 mol%)
2) ENR50: Epoxidized natural rubber (trade name: ENR50, manufactured by RRIM) (epoxidation degree (epoxidation rate): 50 mol%)
3) ENR10: Epoxidized natural rubber (trade name: ENR-10, manufactured by Kumpulan Guthuri Berhard) (epoxidation degree (epoxidation rate): 10 mol%)
4) ENR60: Epoxidized natural rubber (trade name: ENR-60, manufactured by MUANG MAI GUTHURIE) (Degree of epoxidation (epoxidation rate): 60 mol%)
5) BR: “BR01” manufactured by JSR
6) Carbon Black: “Seast NB” manufactured by Tokai Carbon
7) Tackifying resin: “KORSIN” manufactured by BASF AKTIENGEELLS, phenolic 8) Anti-aging agent: “Antigen 6C” manufactured by Sumitomo Chemical Co., Ltd., chemical name N-phenyl-N′-1,3-dimethylbutyl-p-phenylene Diamine 9) Vulcanization accelerator: “Noxeller CZ-G” manufactured by Ouchi Shinsei Chemical Co., Ltd., chemical name N-cyclohexyl-2-benzothiazolesulfenamide 10) Softener (oil) [TOP, Daihachi Chemical Co., Ltd. ) Made] 3 parts by mass

[Examples 5 to 8]
The operation was performed in the same manner as in Example 1 except that the inner liner (21 layer film) was used in place of the inner liner (5 layer film) and that the components in Table 2 were used as the components of the rubber layer. It was. The results are shown in Table 2.

[Comparative Examples 3 to 4]
The operation was performed in the same manner as in Comparative Example 1 except that the inner liner (21 layer film) was used instead of the inner liner (5 layer film) and that the components in Table 2 were used as the components of the rubber layer. It was. The results are shown in Table 2.

[Examples 9 to 12]
The operation was performed in the same manner as in Example 1 except that the components in Table 5 were used as the components of the rubber layer. The results are shown in Table 3.

The various chemicals in Table 3 are as follows.
EBR (1) to (2): produced in the above production example ENR10: as in Table 1 Carbon black: Show Black N220 (N2SA: 125 m2 / g) manufactured by Cabot Japan Co., Ltd.
Anti-aging agent: NOCRACK 6C (N-1,3-dimethylbutyl-N′-phenyl-p-phenylenediamine) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Stearic acid: Stearic acid manufactured by NOF Corporation Oil: Process oil PW-380 manufactured by Idemitsu Kosan Co., Ltd.
Zinc oxide: Zinc Hana No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: Powdered sulfur manufactured by Tsurumi Chemical Co., Ltd. Vulcanization accelerator (1): Noxeller CZ (N-t manufactured by Ouchi Shinsei Chemical Co., Ltd.) -Butyl-2-benzothiazolylsulfenamide)

[result]
As shown in Table 1 (main components of rubber layer: ENR, layers containing thermoplastic resin: 5 layers), Examples 1 to 4 in which the rubber layer contains ENR are cracks and film peeling after a drum running test of the tire. There was no gas barrier property. On the other hand, Comparative Examples 1 and 2 in which the rubber layer did not contain ENR caused film peeling after the drum running test of the tire and had poor gas barrier properties.
As shown in Table 2 (main component of rubber layer: ENR, layer containing thermoplastic resin: 21 layers), Examples 5 to 8 in which the rubber layer contains ENR are cracks and film peeling after the drum running test of the tire. There was no gas barrier property. On the other hand, in Comparative Examples 3 to 4 in which the rubber layer did not contain ENR, film peeling occurred after the tire drum running test, and the gas barrier property was inferior.
As shown in Table 3 (main component of rubber layer: EBR, layer containing thermoplastic resin: 5 layers), Examples 9-12, in which the rubber layer contains ENR, are cracks and film peeling after the drum running test of the tire. There was no gas barrier property.

  DESCRIPTION OF SYMBOLS 1 ... Beat core, 2 ... Carcass, 3 ... Inner liner, 4 ... Belt part, 5 ... Tread part, 6 ... Side wall part, 7 ... Rubber layer, 9 ... Pneumatic tire, 10 ... Laminated body, 11 ... Thermoplastic resin Layer containing film, 12 ... rubber layer

Claims (10)

It has a layer containing a thermoplastic resin film having a laminated structure of a thermoplastic resin film (A layer) and a layer composed of a resin composition containing an elastomer (B layer) having a total number of layers of 7 or more, and a rubber layer A pneumatic tire using a laminate,
The rubber layer contains two or more kinds of modified diene polymers having different modification rates ;
The pneumatic tire is characterized in that the laminated body is arranged as an inner liner so that the rubber layer is on the outside and the layer containing the thermoplastic resin film is on the inside.   The pneumatic tire according to claim 1, wherein the rubber layer has a thickness of 0.1 to 30 mm. 3. The pneumatic tire according to claim 1, wherein the rubber layer has a dynamic storage elastic modulus E ′ at −20 ° C. of 1.0 × 10 ^{5 to} 1.0 × 10 ⁸ Pa. 4.   The pneumatic tire according to any one of claims 1 to 3, wherein the modified diene polymer has a glass transition temperature of 0 ° C or lower.   The pneumatic tire according to any one of claims 1 to 4, wherein the modified diene polymer is an epoxy-modified diene polymer.   The pneumatic tire according to claim 5, wherein the modified diene polymer is one or more selected from epoxidized natural rubber, epoxidized polybutadiene rubber, and epoxidized polyisoprene rubber. In at least two combinations of two or more modified diene polymers having different modification ratio of the rubber layer, modification rate 5-30 mole% of the modified diene polymers and modification rate 40 to 90 mole% of the modified diene polymer the pneumatic tire according to any one of certain claims 1-6.   The pneumatic tire according to claim 1, wherein the layer including the thermoplastic resin film is a multilayer structure including 17 layers or more.   The layer including the thermoplastic resin film, wherein one of the thermoplastic resin film (A layer) and the layer (B layer) made of a resin composition including an elastomer is an outer layer in contact with the rubber layer. A pneumatic tire given in any 1 paragraph. The laminate according to any one of claims 1 to 9 is wound around a tire molding drum so that the rubber layer is on the outside, and after further wrapping a tire member, the molding drum is pulled out to obtain a green tire, A method for producing a pneumatic tire by heating and vulcanizing the green tire to obtain a pneumatic tire.