JP2014037116A - Method for manufacturing a laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminate capable of inhibiting the generation of bubbles between a resin film layer and a tackifier/adhesive layer.SOLUTION: The provided method for manufacturing a laminate is a method for manufacturing a laminate including a resin film layer and a tackifier/adhesive layer wherein peaks and valleys are formed on the adhesion interface of the tackifier/adhesive layer with the resin film layer, wherein the average length RSm of contour curve elements of the peaks and valleys in compliance with JIS B 0601 : 2001 is 1000 μm or below, and wherein the arithmetic mean roughness Ra of the peaks and valleys in compliance with JIS B 0601 : 2001 is 2-50 μm; a laminate obtained by the same manufacturing method and a pneumatic tire possessing the laminate as an inner liner layer are also provided.

Description

  The present invention includes a method for producing a laminate having a resin film layer and an adhesive layer, a laminate obtained by the production method, a tire inner liner using the laminate, and the inner liner. Related to tires.

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. Has been proposed (for example, Patent Documents 1, 2, and 3).
In the case of air bubbles in the conventional inner liner consisting of a rubber layer mainly composed of butyl rubber, the rubber layer will remain clean even if the unvulcanized inner liner is scrubbed when the tire is molded. There is no problem because the hole made is self-repaired when the tire is vulcanized.
However, when the resin film layer is used as an inner liner and the resin film layer and the adhesive layer are bonded together, bubbles may enter between the layers. In this case, if the inner liner of the resin film layer is cracked, it cannot be repaired and the hole will remain open, and the function as the inner liner will be lost. There wasn't.
In addition, the inner liner breaks along with the bubbles due to the pressure at the time of molding or vulcanizing the tire, and the function as the gas barrier layer may be lost, or the gas barrier property may be deteriorated.

JP-A-6-40207 JP 2004-176048 A JP 2007-099146 A

  Under such circumstances, an object of the present invention is to provide a method for producing a laminate that can suppress the generation of bubbles between a resin film layer and an adhesive layer.

  The inventors of the present invention have arrived at the present invention by focusing on the surface properties of the adhesive surface of the adhesive layer to the resin film layer in a laminate having a resin film and an adhesive layer, and earnestly researching it. did.

That is, the present invention provides the following [1] to [2].
[1] A method for producing a laminate having a resin film layer and an adhesive layer, wherein irregularities are formed on the adhesive surface of the adhesive layer with the resin film layer, and JIS B 0601 of the irregularities is formed. : The average length RSm of the contour curve element based on 2001 is 1000 μm or less, and the arithmetic average roughness Ra based on JIS B 0601: 2001 is 2-50 μm. Production method.
[2] A laminate obtained by the production method according to [1].
[3] An inner liner for a tire using the laminate according to [2].
[4] A tire provided with the inner liner according to [3].

  According to this invention, generation | occurrence | production of the bubble between the resin film layer and adhesive agent layer of a laminated body can be suppressed. And gas barrier property becomes still better by using the obtained laminated body as an inner liner for tires.

It is typical sectional drawing which shows an example of the laminated body obtained with the manufacturing method of this invention.

[Laminate]
Hereinafter, the laminate obtained by the production method 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 a laminate obtained by the production method of the present invention.
The laminate 10 in FIG. 1 has a resin film layer 11 and an adhesive layer 12.
The resin film layer 11 may be composed of a single layer of the gas barrier layer 11a, may be composed of two or more layers of the gas barrier layer 11a, and may be composed of two or more layers of the gas barrier layer 11a and other layers. It may consist of multiple layers.
As shown in FIG. 1, it is preferable that the laminated body 10 has the gas barrier layer 11a and the elastomer layer 11b. Thereby, even when the ductility of the gas barrier layer 11a is low, the overall ductility of the resin film layer 11 can be increased, and the resin film layer 11 can be made flexible in a low temperature environment.

[Manufacturing method of laminate]
The manufacturing method of the laminated body 10 of this invention is a manufacturing method of the laminated body which has the resin film layer 11 and the adhesive layer 12, Comprising: On the adhesive surface with the resin film layer 11 of the adhesive layer 12 Concavities and convexities are formed, the average length RSm of the contour curve elements conforming to JIS B 0601: 2001 is 1000 μm or less, and the arithmetic average roughness Ra of the concavities and convexities conforming to JIS B 0601: 2001 is 2 It is characterized by being 50 μm. The reason why the unevenness is formed on the adhesive surface of the adhesive layer 12 with the resin film layer 11 is to suppress the generation of bubbles between the resin film layer 11 and the adhesive layer 12.
The average length RSm of the contour curve element in accordance with JIS B 0601: 2001 of the unevenness is required to be 1000 μm or less. This is because if the thickness is 1000 μm or less, the resin film layer 11 and the adhesive layer 12 can be bonded together while keeping the adhesion between them and degassing. In this respect, the thickness is preferably 1 to 1000 μm, and more preferably 1 to 500 μm.
Moreover, arithmetic mean roughness Ra based on the said uneven | corrugated JISB0601: 2001 needs to be 2-50 micrometers. If it is 2 micrometers or more, generation | occurrence | production of the bubble between a resin film layer and an adhesive agent layer can be suppressed suitably. Moreover, if it is 50 micrometers or less, the processability of an unevenness | corrugation will improve.

The formation method of the unevenness | corrugation of the adhesive agent layer 12 surface of the laminated body 10 of this invention is demonstrated concretely.
The method for forming the first unevenness is a roll with embossing in a shape that makes the necessary RSm and Ra just before the resin film layer 11 and the adhesive layer 12 are bonded together. Make the surface uneven by sandwiching it. In this case, the adhesive sheet may be obtained by previously forming the adhesive composition into a sheet form, or processing the adhesive composition into an uneven sheet form on an embossed roll. May be.
The method for forming the second surface irregularity is transfer from a polysheet. Usually, after rolling, an anti-adhesive polysheet or the like is bonded to the adhesive sheet, but the polysheet is shaped into the necessary RSm and Ra and transferred to the adhesive sheet. The policy is peeled off immediately before the adhesive layer 12 is bonded to the resin film layer 11.
In addition, as a formation method of an unevenness | corrugation, it is not limited to said formation method.
As a method for producing an adhesive sheet in the case of preparing an adhesive sheet in advance, for example, a method of producing an adhesive layer sheet using an extruder or the like can be mentioned.

<Multilayer structure>
The resin film layer 11 according to the present invention is preferably a multilayer structure having 3 or more gas barrier layers 11a and elastomer layers 11b in total, more preferably a multilayer structure having 5 or more layers, and 7 or more layers. More preferably, it is a multilayer structure having the same. This is because the resin film layer 11 has a low gas permeability and a laminated body excellent in crack resistance in a low temperature environment. The upper limit of the number of layers of the multilayer structure is not particularly limited, but is preferably 2000 layers or less.

This multilayer structure has a C layer other than the gas barrier layer 11a (hereinafter sometimes abbreviated as “A layer”) and the elastomer layer 11b (hereinafter sometimes abbreviated as “B layer”). It is also possible. 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, A, B, B... B, B (that is, (AABB) _n )
A stacking order such as can be adopted. Moreover, when it has other C layers, for example,
(5) A, B, C... A, B, C (that is, (ABC) _n )
A stacking order such as 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 gas barrier layer 11a and the elastomer layer 11b, it is preferable that the gas barrier layer 11a and the elastomer layer 11b are alternately stacked as in (1), (2), or (3). Thus, active energy rays may be irradiated to the laminate in which the gas barrier layers 11a and the elastomer layers 11b are alternately laminated, thereby improving the bonding between the laminated layers and exhibiting high adhesiveness. be able to. 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. In addition, by alternately laminating the gas barrier layer 11a and the elastomer layer 11b, the gas barrier layer 11a is sandwiched between the elastomer layer 11b from both sides, so that the ductility of the gas barrier layer 11a is further improved. By alternately disposing the gas barrier layer 11a and the elastomer layer 11b, even if the ductility of the gas barrier layer 11a is low, the overall ductility of the resin film layer 11 can be further increased, and the resin film layer 11 can be reduced in temperature. More flexibility in the environment.

  In this multilayer structure, the average thickness of each layer of the gas barrier layer 11a and the elastomer layer 11b is preferably 0.001 to 40 μm, and more preferably 0.001 to 10 μm. By setting the average thickness of one layer of the gas barrier layer 11a and the elastomer layer 11b within the above range, the number can be increased even when the overall thickness of the multilayer structure is the same. Permeability, bending resistance, etc. can be further improved.

  In the multilayer structure, the gas barrier layer 11a having a thickness in the above range and the elastomer layer 11b made of a resin composition containing an elastomer are laminated, so even when the gas barrier resin itself has low ductility, The ductility of the gas barrier layer 11a made of a resin composition having low ductility can be further increased. This is thought to be because the gas barrier layer 11a made of a resin composition with low ductility is thinly laminated on the elastomer layer 11b with excellent ductility, so that the resin composition with low ductility is transferred to a state with high ductility. . The present inventor pays attention to the above fact, and the gas barrier layer 11a is generally made of a material having low ductility. 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 gas barrier layer 11a is preferably 0.001 μm, more preferably 0.005 μm, and still more preferably 0.01 μm. On the other hand, the upper limit of the average thickness of the gas barrier layer 11a is preferably 40 μm, more preferably 10 μm, further preferably 7 μm, further preferably 5 μm, further preferably 3 μm, further preferably 1 μm, and further preferably 0.5 μm, 0.2 μm, further 0.1 μm is particularly preferable, and 0.05 μm is most preferable.

  If the average thickness of one gas barrier layer 11a is not less than the above lower limit, it becomes easy to form with a uniform thickness, and the low gas permeability and the bending resistance of the multilayer structure are improved. On the contrary, if the average thickness of one gas barrier layer 11a is not more than the above upper limit, the ductility of the gas barrier layer 11a is improved when the thickness of the entire multilayer structure is the same, and the durability and crack resistance of the multilayer structure are improved. Will be improved. The average thickness of one layer of the gas barrier layer 11a is a value obtained by dividing the total thickness of all the gas barrier layers 11a included in the multilayer structure by the number of layers of the gas barrier layers 11a.

  The lower limit of the average thickness of one elastomer layer 11b is preferably 0.001 μm, more preferably 0.005 μm, and even more preferably 0.01 μm for the same reason as the gas barrier layer 11a. On the other hand, the upper limit of the average thickness of one elastomer layer 11b is preferably 40 μm, more preferably 20 μm, and even more preferably 20 μm or less. If the average thickness of one elastomer layer 11b is less than or equal to the above upper limit, the durability and crack resistance of the multilayer structure will be improved when the thickness of the entire multilayer structure is the same. The average thickness of one layer of the elastomer layer 11b is a value obtained by dividing the total thickness of all the elastomer layers 11b included in the multilayer structure by the number of layers of the elastomer layer 11b.

  Regarding the average thickness of one elastomer layer 11b, the ratio of the average thickness of one elastomer layer 11b to the average thickness of one gas barrier layer 11a (elastomer layer 11b / gas barrier layer 11a) is preferably 1/3 or more. / 2 or more is more preferable. The ratio is 1 or more, that is, the average thickness of one elastomer layer 11b is more preferably equal to or more than the average thickness of one gas barrier layer 11a, and more preferably 2 or more. By making the ratio of the thicknesses of the gas barrier layer 11a and the elastomer layer 11b 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 keeping the thickness of the multilayer structure within the above range, the average thickness of the gas barrier layer 11a and the elastomer layer 11b is kept within the above range, and the applicability to an inner liner of a pneumatic tire is maintained. In addition, 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.

≪Gas barrier layer≫
The gas barrier layer 11a is made of a gas barrier resin having an oxygen permeability coefficient at 60 ° C. and 65 RH% smaller than 1.0 × 10 ⁻¹⁰ cm ³ · cm / (cm ² · sec · cmHg). The gas barrier layer 11a can be made thin in order to enhance the retainability, and when used as a tire inner liner, the weight of the tire can be reduced sufficiently, which is preferable.
The resin film layer 11 preferably has an oxygen permeability coefficient (60 ° C., 65 RH%) smaller than 7.0 × 10 ⁻¹⁰ cm ³ · cm / (cm ² · sec · cmHg).
The oxygen permeation coefficient of the gas barrier layer, elastomer layer, resin film layer, etc. is determined according to each rubber composition in accordance with JIS K 7126-1: 2006 “Plastics—Film and Sheet—Gas Permeability Test Method—Part 1: Differential Pressure Method” The oxygen permeability coefficient of the object is measured. Specifically, the oxygen transmission coefficient is measured at 60 ° C. and 65 RH% using a trade name “GTR-10X” manufactured by GTR-TEC.

The gas barrier resin used for the gas barrier layer 11a is not particularly limited as long as a desired air barrier property (especially oxygen barrier property) can be secured. For example, polyamide resin, ethylene-vinyl alcohol copolymer, modified ethylene-vinyl alcohol copolymer, urethane polymer, polyvinylidene chloride resin, polyester resin, olefin polymer or diene polymer, etc. Is mentioned. Moreover, these resin may be used individually by 1 type, and may be used in combination of 2 or more type.
Further, the gas barrier resin is preferably at least one of resins having a polar group of OH, S, Cl or F. This is because when the gas barrier resin has these polar groups, the cohesive energy density is increased, and as a result, the gas barrier property can be further improved.
Furthermore, it is preferable that the resin having a polar group is at least one selected from an ethylene-vinyl alcohol copolymer and a modified ethylene-vinyl alcohol copolymer. This is because such a resin has a low air permeation amount and excellent gas barrier properties.

  The ethylene-vinyl alcohol copolymer (EVOH) preferably has an ethylene content of 10 to 60 mol%, more preferably 20 to 55 mol%, and more preferably 25 to 50 mol%. Preferably, it is 30 to 48 mol%, more preferably 35 to 45 mol%. If the ethylene content is 10 mol% or more, the crack resistance, fatigue resistance and melt moldability are improved. On the other hand, if the ethylene content is 60 mol% or less, the gas barrier properties can be sufficiently secured. The ethylene-vinyl alcohol copolymer preferably has a saponification degree of 80% or more, more preferably 90% or more, still more preferably 95% or more, and 99 % Or more is more preferable. If the degree of saponification is 80% or more, the gas barrier properties and the thermal stability during molding will be better. Further, the ethylene-vinyl alcohol copolymer preferably has a melt flow rate (MFR) of 0.1 to 30 g / 10 minutes under a load of 190 ° C. and 2160 g, and 0.3 to 25 g / 10 minutes. More preferably.

The modified ethylene-vinyl alcohol copolymer can be obtained, for example, by reacting an ethylene-vinyl alcohol copolymer with an epoxy compound. 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.
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 to react 1-50 mass parts with respect to 100 mass parts of ethylene-vinyl alcohol copolymers, and it is further more preferable that the said epoxy compound is made to react 2-40 mass parts, 5-35 mass parts. It is more preferable to react.

Furthermore, the gas barrier layer 11a is preferably cross-linked. If the gas barrier layer 11a is cross-linked, the laminated body can be prevented from being deformed and non-uniform in the vulcanization process of the tire, and the gas barrier property, flex resistance, and fatigue resistance of the gas barrier layer 11a are improved. 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 gas barrier layer 11a is processed into a molded body such as a film or a sheet or a multilayer structure. 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.
If the cross-linking treatment is performed after processing into a multilayer structure, it is considered that the cross-linking reaction between the molecules occurs at the interface between the gas barrier layer 11a and the elastomer layer 11b due to the irradiation of the active energy ray, and is strongly bonded. Interlayer adhesion is exhibited.
Moreover, in order to improve the adhesiveness with the adhesive layer 12, the gas barrier layer 11a is subjected to corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), flame treatment, matured air treatment, ozone, ultraviolet irradiation treatment. Etc. may be processed. Among these, corona discharge treatment is preferable.

≪Elastomer layer≫
The multilayer structure preferably further includes one or more elastomer layers 11b 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. Preferred examples of the thermoplastic urethane elastomer include polyester urethane and polyether urethane.

<Method for producing multilayer structure>
The method for producing the multilayer structure is not particularly limited as long as the gas barrier layer 11a and the elastomer layer 11b are satisfactorily laminated and bonded. For example, coextrusion, bonding, coating, bonding, adhesion, etc. These known methods can be employed. Among these, a method of molding by a multilayer coextrusion method using a resin composition for forming the gas barrier layer 11a and a resin composition for forming the elastomer layer 11b is preferable.
In the multi-layer coextrusion method, the resin composition for forming the gas barrier layer 11a and the resin composition for forming the elastomer layer 11b are heated and melted and supplied to the extrusion die from different extruders and pumps through the respective flow paths. The multilayer structure is formed by extruding into multiple layers from the extrusion die and then laminating and bonding. As this extrusion die, for example, a multi-manifold die, a field block, a static mixer, or the like can be used.

<Adhesive layer>
The adhesive composition constituting the adhesive layer 12 according to the present invention preferably 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 includes epoxy group, amino group, imino group, nitrile group, ammonium group, isocyanate group, imide group, amide group, hydrazo group, azo group, diazo group, hydroxyl group, carboxyl group, carbonyl group, oxy Examples include carbonyl group, sulfide group, disulfide group, sulfonyl group, sulfinyl group, thiocarbonyl group, nitrogen-containing heterocyclic group, oxygen-containing heterocyclic group, alkoxysilyl group and tin-containing group, and epoxy group and isocyanate group are particularly preferable. .
Examples of the modified diene polymer include modified natural rubber and / or modified synthetic rubber. Examples of the modified synthetic rubber include modified polyisoprene rubber (IR), modified polybutadiene rubber (BR), modified styrene-butadiene copolymer (SBR), and modified styrene-isoprene copolymer (SIR). These modified natural rubber and modified synthetic rubber are excellent in durability in a low temperature environment.
The modified diene polymer is preferably an epoxidized diene polymer. Examples of the epoxidized diene polymer include epoxidized natural rubber (hereinafter abbreviated as “ENR”) and / or epoxidized polybutadiene rubber (hereinafter abbreviated as “EBR”). Preferably used.

(Epoxidized natural rubber (ENR))
As the epoxidized natural rubber (ENR) suitably used in the present invention, a commercially available epoxidized natural rubber may be used, or a 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). In addition, the content of epoxy groups is measured from IR and elemental analysis.
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. The epoxidation rate means the mol% of the olefin unsaturation position originally present in the rubber converted to oxirane, and is sometimes referred to as “oxirane enzyme concentration”.

  As ENRs having different epoxidation rates, (a) at least two combinations of ENRs having an epoxidation rate of 5 to 30 mol% and (b) ENRs having an epoxidation rate of 40 to 90 mol% are preferable. The total content of the ENR combination in the rubber component of the adhesive composition constituting the adhesive layer 12 is preferably 80 to 100% by mass. If the total content of the combination of the ENRs in the rubber component of the adhesive composition constituting the adhesive layer 12 is in the range of 80 to 100% by mass, the components in the adhesive layer 12 The compatibility is improved, and the adhesive force and the durability of the adhesive layer 12 are improved. From such a viewpoint, the total content of the ENR combination in the rubber component of the adhesive composition constituting the adhesive layer 12 is more preferably 90 to 100% by mass, and 100% by mass. Most preferably.

Further, by using an 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 at −20 ° C. of the adhesive layer 12 is maintained. The rise of ₂ '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, the gas barrier property of the resulting laminate 10 is obtained by acting on the functional groups in the resin film 11 utilizing the properties of the ENR. Can be improved.
In the present invention, the content ratio of the low epoxidation rate ENR and the high epoxidation rate ENR is a mass ratio (low epoxidation rate ENR / High epoxidation rate ENR) is preferably in the range of 20:80 to 80:20.

≪Vulcanizing agent, vulcanization accelerator≫
The adhesive composition constituting the adhesive layer 12 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 rubber components, More preferably, it is 1.0-5 mass parts. is there.
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 adhesive composition constituting the adhesive layer 12 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, N339, IISAF, ISAF, SAF, GPF, etc. are mentioned.
The content of these fillers is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the rubber component of the adhesive composition. From the viewpoints of tackiness and peel resistance, the inorganic filler 5 is combined with carbon black. It is preferable to contain at least part by mass.

(Tackifying resin)
Examples of the tackifying resin having the function of imparting tackiness to the adhesive layer 12 include phenolic resins, terpene resins, modified terpene resins, hydrogenated terpene resins, rosin resins, C5 and C9 petroleum resins. , Xylene resin, coumarone-indene resin, dicyclopentadiene resin, styrene resin, etc., among these, phenol resin, terpene resin, modified terpene resin, hydrogenated terpene resin and rosin resin Is preferred.
Examples of the phenolic resin include a resin obtained by condensing pt-butylphenol and acetylene in the presence of a catalyst (p-tert-butylphenol / acetylene resin), a condensate of alkylphenol and formaldehyde, and the like. 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 further preferably 5 to 30 parts by mass with respect to 100 parts by mass of the rubber component of the adhesive composition. Used.

(Softener)
Examples of softeners include process oil and plasticizer. Examples of the process oil include paraffinic oil and naphthenic oil. Preferred examples of the plasticizer include tris (2-ethylhexyl) phosphate (TOP: manufactured by Daihachi Chemical Industry Co., Ltd.).

  The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 12 can be prepared by mixing the respective components using, for example, a Banbury mixer or a roll.

≪Thickness of adhesive layer≫
The thickness of the adhesive layer 12 is preferably 0.1 to 2 mm, more preferably 0.1 to 1 mm, and still more preferably 0.1 to 0.4 mm. If it is 0.1 mm or more, a thermoplastic resin film and a carcass can be firmly joined, and the function of improving crack resistance in a low-temperature environment is exhibited well. If it is 2 mm or less, weight reduction of a pneumatic tire will be achieved.

[Pneumatic tire manufacturing method]
In the method for manufacturing a pneumatic tire according to the present invention, the laminate 10 is wound around a tire molding drum so that the adhesive layer 12 is on the outer side to form an inner liner. The green tire is heated and vulcanized to obtain a pneumatic tire.

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) Epoxidation rate of ENR ENR was dissolved in deuterated chloroform, and carbon-carbon double bond part and fat were 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 family part using the following calculation formula.
(2) Average length RSm and arithmetic average roughness Ra of the contour curve element
Measured according to JIS B 0601: 2001.
(3) Presence / absence of bubbles remaining The interface between the tire resin film layer and the adhesive layer was visually evaluated.

[Production Example 1] Production of resin film layer (21-layer film) EVOH ["E105" manufactured by Kuraray Co., Ltd. {ethylene content: 44 mol%, saponification degree: 99.9%, melt flow rate (MFR): 5.5 g / 10 min (190 ° C., 2160 g)}] and a polyester-based thermoplastic polyurethane (TPU) [“Kuramylon 3190” manufactured by Kuraray Co., Ltd.], using a two-type 21-layer multilayer coextrusion apparatus Then, a film layer having a 21-layer structure under the following coextrusion molding conditions (TPU layer / EVOH layer / TPU layer... EVOH layer / TPU layer. TPU layer: 11 layers and EVOH layer: 10 layers were alternately arranged) Was made. 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
Pickup speed: 4m / min

Examples 1 and 2 and Comparative Examples 1 and 2
(1) Preparation of adhesive layer The components of the adhesive composition shown in Table 1 are kneaded according to a conventional method, and formed into a sheet having a thickness of 400 μm using an extruder. An adhesive sheet was prepared.
(2) Production of Laminate A laminate having the resin film layer and the adhesive layer bonded to one side of the resin film layer (21-layer film) obtained in Production Example 1. Was made. When the adhesive sheet was bonded, the resin film layer side surface of the adhesive sheet was sandwiched between embossed rolls to make the surface uneven. The irregularities RSm and Ra of Examples 1 and 2 and Comparative Examples 1 and 2 are as shown in Table 2.

(3) Preparation of tire Each of the laminates of Examples 1 and 2 and Comparative Examples 1 and 2 is wound on a tire molding drum so that the resin film layer (21-layer film) side of the laminate faces the drum. And used as an inner liner. Next, a carcass was wound on the laminate, and further, 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).
With respect to the four types of tires of Examples 1 and 2 and Comparative Examples 1 and 2 obtained, the above measurement method was evaluated for the presence or absence of remaining bubbles. The results are shown in Table 2.

[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) Carbon black: HAF manufactured by Tokai Carbon Co., Ltd., trade name “Seast NB”
4) Anti-aging agent: Chemical name N-phenyl-N′-1,3-dimethylbutyl-p-phenylenediamine, manufactured by Sumitomo Chemical Co., Ltd., trade name “antigen 6C”
5) Tackifier: p-tert-butylphenol / acetylene resin, manufactured by BASF, trade name “KORESIN” (registered trademark)
6) Softener: Paraffinic oil: Idemitsu Kosan Co., Ltd., trade name "Process Oil PW-380"
7) Vulcanization accelerator CZ: Chemical name N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “Noxeller CZ-G”

  As is apparent from Table 2, no bubble residue was observed in the laminates of Examples 1 and 2.

Since the laminated body of the present invention can suitably suppress air bubbles remaining in an inner liner for a pneumatic tire using the laminated body and a pneumatic tire provided with the inner liner, the gas barrier property is further improved, compared to the conventional case, Furthermore, it is industrially useful in that a pneumatic tire that can be used for a long time is obtained.
[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Laminate 11 Resin film layer 11a Gas barrier layer 11b Elastomer layer 12 Adhesive layer

Claims (7)

  A method for producing a laminate having a resin film layer and an adhesive layer, wherein irregularities are formed on the adhesive surface of the adhesive layer with the resin film layer, and the irregularities are defined in JIS B 0601: 2001. An average length RSm of conforming contour curve elements is 1000 μm or less, and an arithmetic average roughness Ra based on JIS B 0601: 2001 of the unevenness is 2 to 50 μm.   The method for producing a laminate according to claim 1, wherein the resin film layer has a gas barrier layer and an elastomer layer.   The manufacturing method of the laminated body of Claim 1 or 2 in which the said adhesive layer contains an epoxidized diene type polymer.   The method for producing a laminate according to claim 3, wherein the epoxidized diene polymer is an epoxidized natural rubber.   The laminated body obtained by the manufacturing method in any one of Claims 1-4.   An inner liner for a tire using the laminate according to claim 5.   A tire comprising the inner liner according to claim 6.

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