JP2019077072A - Laminate for pneumatic tire, inner liner material and method for producing pneumatic tire - Google Patents

Abstract

To reduce heat generation property and improve adhesion of a laminate including a layer of a rubber composition, a layer of a thermoplastic resin or a layer of a thermoplastic elastomer composition.SOLUTION: A laminate for pneumatic tire includes a layer for unvulcanized rubber composition, a layer of a thermoplastic resin or a layer of a thermoplastic elastomer composition, in which the unvulcanized rubber composition contains a rubber component, and with respect to 100 pts.mass of the rubber component, 0.5-20 pts.mass of a condensate of a substituted or non-substituted phenol compound having a specific structure and formaldehyde, 0.25-200 pts.mass of a methylene donor, 0.5-5 pts.mass of a substituted or non-substituted aromatic carboxylic acid having a pKa of 1.5-4.0 at a temperature of 25°C, 20-100 pts.mass of calcium carbonate, 0-20 pts.mass of carbon black and a vulcanizer are contained, and a mass ratio of the methylene donor and the condensate is 0.5:1 to 10:1.SELECTED DRAWING: None

Description

  The present invention relates to a laminate for a pneumatic tire comprising a layer of an unvulcanized rubber composition and a layer of a thermoplastic resin or a layer of a thermoplastic elastomer composition, an inner liner material comprising the laminate, and a pneumatic tire It relates to the manufacturing method.

  Heretofore, the rolling resistance (heat buildup) of a pneumatic tire has been reduced by replacing part of carbon black contained as a filler in a rubber composition with silica to improve the fuel economy of automobiles. . However, Patent Document 1 has a problem that the hardness of the rubber composition is lowered due to the low fuel consumption (low heat generation) by silica, so that the tire is softened and the flex crack growth resistance is lowered. It is described to replace part or all of the silica with calcium carbonate by setting the content of black to preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. On the other hand, in order to reduce the manufacturing cost of the pneumatic tire, it is required to simplify the manufacturing process, and to meet such a demand, the inventor previously made a laminate or a laminate that constitutes the pneumatic tire. When manufacturing a pneumatic tire, a film of a thermoplastic resin or a thermoplastic elastomer composition as a technique for bonding a layer of a thermoplastic resin composition and a layer of an unvulcanized rubber composition without using an adhesive layer Patent Document 2 proposes a technique for laminating a layer of a rubber composition containing a condensation product of a phenolic compound and formaldehyde and a methylene donor (Patent Document 2).

JP, 2014-145033, A Patent No. 4858654

  While silica is less exothermic in the tire as compared to carbon black, carbon black and silica are both materials that increase heat buildup. The inventors of the present invention have made intensive studies as a result of intensive investigation for the purpose of further reducing the heat buildup of the layer of the rubber composition without losing the high adhesive strength between the thermoplastic resin film and the layer of the rubber composition. In a vulcanized rubber composition, even when the amount of carbon black is reduced, the unvulcanized rubber composition contains a rubber component, a specific amount of phenol-formaldehyde condensate and a methylene donor, and further a specific amount of a specific aroma It has been found that the above object is achieved when it comprises a group carboxylic acid and a certain amount of calcium carbonate, and the present invention has been completed.

According to the present invention, there is provided a pneumatic tire comprising a layer of an unvulcanized rubber composition and a layer of a thermoplastic resin or a layer of a thermoplastic elastomer composition joined to the layer of the unvulcanized rubber composition. It is a laminate, and the above-mentioned unvulcanized rubber composition is
(A) rubber component,
(B) 0.5 to 20 parts by mass of the following formula (1): 100 parts by mass of the rubber component (A):

(Wherein, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group having 1 to 8 carbon atoms, and the number of carbon atoms Independently selected from the group consisting of 1 to 8 alkoxide groups)
A condensate of a substituted or unsubstituted phenolic compound represented by
(C) 0.25 to 200 parts by mass of methylene donor with respect to 100 parts by mass of the rubber component (A)
(D) 0.5 to 5 parts by mass, per 100 parts by mass of the rubber component (A), a substituted or unsubstituted aromatic carboxylic acid having a pKa of 1.5 to 4.0 at a temperature of 25 ° C.
(E) 20 to 100 parts by mass of calcium carbonate, per 100 parts by mass of the rubber component (A)
(F) 0 to 20 parts by mass of carbon black with respect to 100 parts by mass of the rubber component (A), and (G) a vulcanizing agent,
And a mass ratio of the methylene donor (C) to the condensate (B) is 0.5: 1 to 10: 1.

  According to the present invention, there is further provided an inner liner material for a pneumatic tire comprising the above laminate.

  According to the present invention, there is further provided a method of manufacturing a pneumatic tire, including the steps of forming a green tire including the above inner liner material, and vulcanizing the green tire.

Specifically, the present invention includes the following aspects 1 to 8.
[Aspect 1]
A laminate for a pneumatic tire comprising a layer of an unvulcanized rubber composition and a layer of a thermoplastic resin or a layer of a thermoplastic elastomer composition, wherein the unvulcanized rubber composition is
(A) rubber component,
(B) 0.5 to 20 parts by mass of the following formula (1): 100 parts by mass of the rubber component (A):

(Wherein, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group having 1 to 8 carbon atoms, and the number of carbon atoms Independently selected from the group consisting of 1 to 8 alkoxide groups)
A condensate of a substituted or unsubstituted phenolic compound represented by
(C) 0.25 to 200 parts by mass of methylene donor with respect to 100 parts by mass of the rubber component (A)
(D) 0.5 to 5 parts by mass, per 100 parts by mass of the rubber component (A), a substituted or unsubstituted aromatic carboxylic acid having a pKa of 1.5 to 4.0 at a temperature of 25 ° C.
(E) 20 to 100 parts by mass of calcium carbonate, per 100 parts by mass of the rubber component (A)
(F) 0 to 20 parts by mass of carbon black with respect to 100 parts by mass of the rubber component (A), and (G) a vulcanizing agent,
A laminate for a pneumatic tire, comprising: and a mass ratio of methylene donor (C) to condensate (B) is 0.5: 1 to 10: 1.
[Aspect 2]
The laminate according to the above aspect 1, wherein the calcium carbonate has an average primary particle size of 10 μm or less.
[Aspect 3]
The thermoplastic resin is selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD 6, and nylon 6 T. The laminate according to Aspect 1 or 2, which is at least one selected.
[Aspect 4]
The thermoplastic elastomer composition comprises a thermoplastic resin component and an elastomer component dispersed in the thermoplastic resin component, and the thermoplastic resin component is polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, At least one thermoplastic resin selected from the group consisting of nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD 6 and nylon 6 T, the elastomer component being a brominated isobutylene- At least one selected from the group consisting of p-methylstyrene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer and maleic anhydride-modified ethylene-ethyl acrylate copolymer Above or 1) including Laminate according to 2.
[Aspect 5]
Any of the above embodiments 1 to 4, wherein the methylene donor (C) is at least one selected from the group consisting of modified etherified methylolmelamine, paraformaldehyde, hexamethylenetetramine, pentamethylenetetramine, and hexamethoxymethylmelamine. The laminated body described in one.
[Aspect 6]
The condensate (B) is represented by the formula (2):

(Wherein n is an integer of 1 to 20); or Formula (3):

(Wherein, m is an integer of 1 to 20)
The laminated body as described in any one of the said aspect 1-5 represented by these.
[Aspect 7]
The laminated body as described in any one of the said aspect 1-6 whose rubber component (A) is a diene based rubber.
[Aspect 8]
The inner-liner material for pneumatic tires which consists of a laminated body as described in any one of the said aspect 1-7.
[Aspect 9]
A step of forming a green tire including the inner liner material according to the above aspect 8, and a step of vulcanizing the green tire,
A method of manufacturing a pneumatic tire including:

  The laminate for a pneumatic tire according to the present invention exhibits improved heat buildup without losing its reinforcing property when the unvulcanized rubber composition layer is vulcanized, and the rubber composition layer and thermoplasticity It shows improved adhesion strength with a layer of resin or a layer of thermoplastic elastomer composition. Even though the unvulcanized rubber composition layer and the thermoplastic resin layer or the thermoplastic elastomer composition layer are bonded without an adhesive, the laminate of the present invention should be heated at the following predetermined temperature. By this, high adhesive strength can be expressed between the rubber composition layer and the thermoplastic resin layer or the thermoplastic elastomer composition layer. Since the laminate of the present invention does not contain an adhesive, equipment and work necessary for applying the adhesive can be eliminated, and the laminate can be easily manufactured as compared with the prior art using an adhesive. When a layer of the unvulcanized rubber composition constituting the laminate of the present invention is vulcanized in a state of being laminated or adjacent to another vulcanizable rubber molded article having an arbitrary shape such as a sheet or a film shape Also, the vulcanization reaction occurs between the layer of the unvulcanized rubber composition and the other vulcanizable rubber molded product, and thereby the layer between the unvulcanized rubber composition and the other rubber molded product is strong. Adhesion is achieved. Therefore, according to the present invention, the thermoplastic elastomer composition layer can be firmly adhered to other rubber molded articles, for example, other rubber members constituting the pneumatic tire, through the rubber composition layer, As a result, a composite excellent in low heat buildup and peel strength can be obtained. When a thermoplastic resin such as polyamide or polyvinyl alcohol having excellent gas barrier properties is contained in the thermoplastic resin layer or the thermoplastic elastomer composition, a laminate excellent in gas barrier properties can be obtained, and such a laminate is, for example, It is useful as an inner liner material of a pneumatic tire. A pneumatic tire excellent in low heat buildup, peel strength and gas barrier property can be manufactured using the inner liner material made of the laminate of the present invention.

Hereinafter, the present invention will be described in detail.
[Layer of unvulcanized rubber composition]
In the present invention, the unvulcanized rubber composition constituting the layer of the unvulcanized rubber composition is
(A) rubber component,
(B) 0.5 to 20 parts by mass of the following formula (1): 100 parts by mass of the rubber component (A):

(Wherein, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group having 1 to 8 carbon atoms, and the number of carbon atoms Independently selected from the group consisting of 1 to 8 alkoxide groups)
A condensate of a substituted or unsubstituted phenolic compound represented by
(C) 0.25 to 200 parts by mass of methylene donor with respect to 100 parts by mass of the rubber component (A)
(D) 0.5 to 5 parts by mass, per 100 parts by mass of the rubber component (A), a substituted or unsubstituted aromatic carboxylic acid having a pKa of 1.5 to 4.0 at a temperature of 25 ° C.
(E) 20 to 100 parts by mass of calcium carbonate, per 100 parts by mass of the rubber component (A)
(F) 0 to 20 parts by mass of carbon black with respect to 100 parts by mass of the rubber component (A), and (G) a vulcanizing agent,
And the mass ratio of the methylene donor (C) to the condensate (B) is 0.5: 1 to 10: 1.

(A) Rubber Component The rubber component (A) contains one or more rubbers, preferably one or more diene rubbers. Examples of diene rubbers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR) and the like. The diene rubber is selected from natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), and a combination of two or more thereof, processability, and the unvulcanized rubber relative to the rubber sheet It is preferable from the point of the adhesiveness of the layer of a composition.

(B) Condensed product of substituted or unsubstituted phenolic compound and formaldehyde One preferred example of the substituted or unsubstituted phenolic compound represented by the formula (1) is R ¹ , R ² , R ³ , R ⁴ and at least one of R ⁵ but in 1-8 alkyl carbon atoms, those remainder is hydrogen or a carbon number between 1-8 alkyl group. Another preferable example of the compound represented by the formula (1) is that at least one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ is a hydroxyl group, and the rest is hydrogen or has 1 to 8 carbon atoms. Alkyl groups. The substituted or unsubstituted phenolic compound is more preferably cresol, resorcin, paraoctylphenol. Examples of the condensation product (C) of the substituted or unsubstituted phenol compound and formaldehyde include cresol-formaldehyde condensates, resorcin-formaldehyde condensates, and the like. Moreover, these condensates may be denatured in the range which does not impair the effect of this invention. For example, modified resorcin-formaldehyde condensates modified with epoxy compounds can also be used in the present invention. These condensation products are commercially available, and commercially available products can be used in the present invention. The condensate (C) is preferably a cresol-formaldehyde condensate represented by the following formula (2), or a resorcin-formaldehyde condensate represented by the formula (3).

In the formula, n is an integer of 1 to 20, preferably an integer of 1 to 10, more preferably an integer of 1 to 5.

In the formula, m is an integer of 1 to 20, preferably an integer of 1 to 10, more preferably an integer of 1 to 3.

  The amount of the condensation product (B) is preferably 0.5 to 10 parts by mass, more preferably 1.5 to 6.0 parts by mass with respect to 100 parts by mass of the rubber component (A). When the amount of the condensation product (B) is less than 0.5 parts by mass with respect to 100 parts by mass of the rubber component (A), the layer of the unvulcanized rubber composition and the layer of the thermoplastic resin or the thermoplastic elastomer composition It is difficult to sufficiently improve the adhesive strength between layers, and if it exceeds 10 parts by mass, the resulting rubber composition does not have sufficient elongation properties after vulcanization and is easily broken.

(C) Methylene Donor In the present specification, “methylene donor” refers to a base compound that generates formaldehyde upon heating etc., and examples of methylene donors include hexamethylenetetramine, pentamethylenetetramine, hexamethylenediamine, methylolmelamine Etherified methylolmelamine, modified etherified methylolmelamine, esterified methylolmelamine, hexamethoxymethylmelamine, hexamethylolmelamine, hexakis (ethoxymethyl) melamine, hexakis (methoxymethyl) melamine, N, N ', N''-trimethyl -N, N ', N "-trimethylolmelamine, N, N', N"-trimethylolmelamine, N-methylolmelamine, N, N '-bis (methoxymethyl) melamine, N, N', N '' -Tributyl-N, ', N''- trimethylolmelamine, paraformaldehyde and the like. Preferably, the methylene donor (C) is at least one selected from the group consisting of modified etherified methylolmelamine, paraformaldehyde, hexamethylenetetramine, pentamethylenetetramine, and hexamethoxymethylmelamine. Among them, denatured etherified methylolmelamine is preferable from the viewpoint of the emission temperature of formaldehyde.

  The amount of the methylene donor (C) is preferably 0.25 to 50 parts by mass, more preferably 0.75 to 18 parts by mass, with respect to 100 parts by mass of the rubber component (A). When the amount of the methylene donor is less than 0.25 parts by mass with respect to 100 parts by mass of the rubber component (A), when the laminate of the present invention is heated at the following predetermined temperature, The reaction does not proceed sufficiently, and as a result, it is difficult to improve the adhesive strength. If the amount of methylene donor is too high, the vulcanization system of the rubber composition may be adversely affected.

  The mass ratio of the methylene donor (C) to the condensate (B) is preferably 0.5: 1 to 5: 1, more preferably 1: 1 to 3: 1. When the ratio of the methylene donor (D) to the condensate (B) is too small, the reaction of the condensate (B) does not proceed sufficiently when the laminate of the present invention is heated at the following predetermined temperature, It is difficult to improve sufficiently. If the ratio of the methylene donor (C) to the condensation product (B) is too high, the vulcanization system of the rubber composition may be adversely affected.

(D) Substituted or Unsubstituted Aromatic Carboxylic Acid In the present invention, the unvulcanized rubber composition is a substituted or unsubstituted aromatic carboxylic acid having an acid dissociation constant pKa at _a temperature of 25 ° C. of 1.5 to 4.0. Contains acid. Here, the aromatic carboxylic acid refers to a compound in which at least one hydrogen of the aromatic ring of the aromatic compound is substituted with a carboxyl group. Unsubstituted aromatic carboxylic acids refer to aromatic carboxylic acids having no substituent. The substituted aromatic carboxylic acid refers to a compound in which at least one hydrogen of the aromatic ring of the aromatic carboxylic acid is substituted with a substituent other than a carboxyl group. As a substituent other than a carboxyl group, a C1-C6 alkyl group, a hydroxyl group, an amino group, halogen etc. are mentioned. As the value of acid dissociation constant pK _a is small, indicating a strong acid. If _the pK _a of the aromatic carboxylic acid (D) is too low, may cause vulcanization delay of the unvulcanized rubber components of unvulcanized rubber composition, _the pK _a of the aromatic carboxylic acid (D) in the opposite Is too high, that is, when the acid dissociation constant is too small, it is difficult to sufficiently improve the adhesive strength between the unvulcanized rubber composition layer and the thermoplastic resin layer or the thermoplastic elastomer composition layer.

Specific examples of the substituted or unsubstituted aromatic carboxylic acid having a pKa of 1.5 to 4.0 at a temperature of 25 ° C. include benzoic acid (pK _a = 4.0) and 2,4-dihydroxybenzoic acid (pK _a = 3.2), salicylic acid (o-hydroxybenzoic acid) (pK _a = 2.7), o-aminobenzoic acid (pK _a = 2.0), 4-aminosalicylic acid (pK _a = 1.5) And the like, and one of these may be used or two or more may be used in combination.

  The amount of the substituted or unsubstituted aromatic carboxylic acid (D) is 0.5 to 5 parts by mass, preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component (A). When the amount of the aromatic carboxylic acid (D) is less than 0.5 parts by mass with respect to 100 parts by mass of the rubber component (A), it is difficult to sufficiently improve the adhesive strength, and when it exceeds 5 parts by mass The unvulcanized rubber composition tends to be scorched during processing, or the metal adhesion of the rubber is increased, making roll forming difficult.

(E) Calcium Carbonate In the present invention, the unvulcanized rubber composition contains calcium carbonate. The calcium carbonate used in the present invention is preferably ground calcium carbonate or precipitated calcium carbonate. Calcium carbonate is in the form of powder having an average primary particle diameter of 10 μm or less, preferably 0.1 μm to 10 μm. Here, the average primary particle size of calcium carbonate means a sphere-equivalent primary average particle size obtained from the Kozeny-Carman equation by the permeation method. The amount of calcium carbonate is 20 to 100 parts by mass, preferably 20 to 60 parts by mass, per 100 parts by mass of the rubber component (A). When the amount of calcium carbonate is less than 20 parts by mass with respect to 100 parts by mass of the rubber component (A), it is difficult to sufficiently improve the adhesive strength, and when it exceeds 100 parts by mass, the unvulcanized rubber composition The heat buildup of the rubber after vulcanization is increased.

(F) Carbon black Examples of carbon black contained in the layer of the non-vulcanized rubber composition include GPF (General Purpose Furnace), FEF (Fast Extruding Furnace), HAF (High Abrasion Furnace) and ISAF (Intermediate Super Abrasion Furnace). And other grades of carbon black. These carbon blacks are used alone or in combination of two or more. The carbon black is preferably GPF grade carbon black. The amount of carbon black is 0 to 20 parts by mass, preferably 0 to 10 parts by mass with respect to 100 parts by mass of the rubber component (A). In the present invention, the layer of the rubber composition may not contain carbon black. When the amount of carbon black exceeds 20 parts by mass with respect to 100 parts by mass of the rubber component (A), it is difficult to sufficiently reduce the heat buildup.

(G) Vulcanizing agent Examples of the vulcanizing agent include inorganic vulcanizing agents and organic vulcanizing agents. Examples of inorganic vulcanizing agents include sulfur, sulfur monochloride, selenium, tellurium, zinc oxide, magnesium oxide, lead monoxide and the like, and examples of organic vulcanizing agents include sulfur-containing organic compounds, dithiocarbamine Acid salts, oximes, tetrachloro-p-benzoquinone, dinitroso compounds, modified phenolic resins, polyamines, organic peroxides and the like. Among them, sulfur, organic peroxides such as 1,3-bis- (t-butylperoxyisopropyl) -benzene, modified phenolic resin such as brominated alkylphenol-formaldehyde condensate, zinc oxide, sulfur-containing organic compounds Is preferred.

  The amount of the vulcanizing agent is preferably 0.2 to 5.0 parts by mass, more preferably 1.0 to 4.0 parts by mass with respect to 100 parts by mass of the rubber component (A). When the amount of the vulcanizing agent is too small, the vulcanization reaction of the rubber component (A) does not sufficiently proceed when the laminate of the present invention is heated at the following predetermined temperature, and peeling due to material destruction may occur. If the amount of the vulcanizing agent is too large, premature vulcanization (scorch) may occur before the predetermined vulcanization step.

  In addition to the components (A) to (G) described above, the layer of the rubber composition is, for example, a vulcanization accelerator, a vulcanization accelerator, a softener, and a processing aid as long as the effects of the present invention are not impaired. And various additives that are commonly used in rubber compositions for pneumatic tires, such as anti-aging agents.

[The layer of thermoplastic resin]
Examples of the thermoplastic resin constituting the thermoplastic resin layer include polyamide resin, polyester resin, polynitrile resin, polymethacrylate resin, polyvinyl resin, cellulose resin, fluorine resin, imide resin, polystyrene Examples include system resins and polyolefin resins. The layer of thermoplastic resin can comprise one or more thermoplastic resins. Examples of polyamide resins include nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), Nylon 6/66 (N6 / 66), nylon 6/66/12 (N6 / 66/12), nylon 6/66/610 (N6 / 66/610), nylon MXD6 (MXD6), nylon 6T, nylon 6 / 6T, nylon 9T, nylon 66 / PP copolymer, nylon 66 / PPS copolymer and the like. Examples of polyester resins include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal Examples thereof include polyester and aromatic polyester such as polyoxyalkylene diimidic acid / polybutyrate terephthalate copolymer. Examples of polynitrile resins include polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile / styrene copolymer (AS), methacrylonitrile / styrene copolymer, methacrylonitrile / styrene / butadiene copolymer, etc. It can be mentioned. Examples of polymethacrylate resins include polymethyl methacrylate (PMMA), polyethyl methacrylate and the like. Examples of polyvinyl resins include polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), vinyl chloride / chloride Examples thereof include vinylidene copolymers and vinylidene chloride / methyl acrylate copolymers. Examples of the cellulose-based resin include cellulose acetate, cellulose acetate butyrate and the like. Examples of the fluorine-based resin include polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer (ETFE) and the like. As an example of imide type-resin, aromatic polyimide (PI) etc. are mentioned. Polystyrene (PS) etc. are mentioned as an example of polystyrene resin. Examples of polyolefin resins include polyethylene (PE) and polypropylene (PP). Among them, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD 6 and nylon 6 T are fatigue resistance and air blocking. It is preferable at the point of coexistence of sex.

  The thermoplastic resin is, for example, a filler, a reinforcing agent, a processing aid, a stabilizer, an antioxidant, in order to improve the processability, dispersibility, heat resistance, oxidation resistance, etc., as long as the effects of the present invention are not impaired. A compounding agent such as an agent may be included.

[Layer of Thermoplastic Elastomer Composition]
The thermoplastic elastomer composition comprises one or more elastomers dispersed in one or more thermoplastic resins. In the thermoplastic elastomer composition, one or more thermoplastic resins constitute a matrix phase (or continuous phase), and one or more elastomers constitute a dispersed phase (or discontinuous phase).

  The one or more thermoplastic resins constituting the thermoplastic elastomer composition can be one or two or more of those exemplified for the thermoplastic resin constituting the layer of the above-mentioned thermoplastic resin.

  Examples of the elastomer constituting the thermoplastic elastomer composition include diene rubbers and hydrogenated products thereof, olefin rubbers, halogen-containing rubbers, silicone rubbers, sulfur-containing rubbers, fluororubbers and the like. Examples of diene rubbers and hydrogenated products thereof include natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR) (high cis BR and low cis BR) ), Acrylonitrile butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR and the like. Examples of olefin rubbers include ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), maleic acid modified ethylene propylene rubber (M-EPM), maleic anhydride modified ethylene-α-olefin copolymer, ethylene- Examples include glycidyl methacrylate copolymer, maleic anhydride-modified ethylene-ethyl acrylate copolymer (modified EEA), butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), ionomer, etc. Be Examples of the halogen-containing rubber include halogenated butyl rubber such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR), brominated isobutylene-p-methylstyrene copolymer (BIMS), halogenated isobutylene- An isoprene copolymer rubber, chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorinated polyethylene (M-CM) and the like can be mentioned. Examples of silicone rubber include methyl vinyl silicone rubber, dimethyl silicone rubber, methyl phenyl vinyl silicone rubber and the like. Examples of the sulfur-containing rubber include polysulfide rubber and the like. Examples of fluorine rubber include vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicone rubber, fluorine-containing phosphazene rubber and the like. Among them, brominated isobutylene-p-methylstyrene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer and maleic anhydride-modified ethylene-ethyl acrylate copolymer It is preferable from the viewpoint of blocking property.

  The combination of the elastomer and the thermoplastic resin which can constitute the thermoplastic elastomer composition in the laminate of the present invention is not limited, but halogenated butyl rubber and polyamide based resin, brominated isobutylene-p-methylstyrene Copolymer rubber and polyamide resin, butadiene rubber and polystyrene resin, isoprene rubber and polystyrene resin, hydrogenated butadiene rubber and polystyrene resin, ethylene propylene rubber and polyolefin resin, ethylene propylene diene rubber and polyolefin resin, non-crystal Butadiene rubber and syndiotactic poly (1,2-polybutadiene), non-crystalline isoprene rubber and trans poly (1,4-isoprene), fluoro rubber and fluoro resin, etc. may be mentioned, but butyl rubber and polyurea having excellent air blocking properties A combination of a brominated resin is preferable, and in particular, a combination of brominated isobutylene-p-methylstyrene copolymer rubber which is a modified butyl rubber and a blend resin of nylon 6/66 or nylon 6 or nylon 6/66 and nylon 6, It is particularly preferable in terms of achieving both fatigue resistance and air blocking properties.

  The thermoplastic resin constituting the thermoplastic elastomer composition is obtained by melt-kneading one or more thermoplastic resins and one or more elastomers with, for example, a twin-screw kneading extruder to form a matrix phase. It can be produced by dispersing an elastomer component as a dispersed phase in a thermoplastic resin. The mass ratio of the thermoplastic resin to the elastomer is not limited, but is preferably 10/90 to 90/10, more preferably 15/85 to 90/10.

  The thermoplastic elastomer composition is, for example, a filler, a reinforcing agent, a processing aid, a stabilizer, for the purpose of improving processability, dispersibility, heat resistance, oxidation resistance and the like, as long as the effects of the present invention are not impaired. Ingredients commonly formulated with resin compositions, such as antioxidants, may be included. The elastomer constituting the thermoplastic elastomer composition is a rubber composition such as other reinforcing agents (fillers) such as carbon black and silica, softeners, anti-aging agents, processing aids, etc. within the range that does not inhibit the effects of the present invention. The formulation may contain ingredients generally formulated.

[Production of laminate]
The laminate of the present invention comprises a layer of an unvulcanized rubber composition containing the above components (A) to (G) and optionally additives and a layer of the above thermoplastic resin or a layer of a thermoplastic elastomer composition To form a laminate (hereinafter referred to as “unvulcanized laminate”), and then vulcanizing the obtained unvulcanized laminate by heating at a predetermined temperature of 120 ° C. to 200 ° C. It is possible to manufacture by joining or integrating the layer of the rubber composition and the layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition. More specifically, production of an unvulcanized laminate can be carried out by the following method, but is not limited to the following method. First, an unvulcanized rubber composition containing the above components (A) to (G) and, if necessary, an additive is prepared, and the obtained unvulcanized rubber composition is molded with a forming apparatus such as a T-die extruder. It is molded into a layer to make a layer of an unvulcanized rubber composition. Next, a layer of thermoplastic resin or a layer of thermoplastic elastomer composition is laminated on the layer of unvulcanized rubber composition to produce an unvulcanized laminate. The integration by vulcanization of the unvulcanized laminate can be performed, for example, under vulcanization conditions at a temperature of 120 ° C. to 200 ° C. for 50 seconds to 320 minutes.

  In the present specification, “unvulcanized laminate” means that the layer of the rubber composition and the layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition are laminated. It refers to one that has not been subjected to heating at the vulcanization temperature of the product. Here, with respect to the “layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition” and the “layer of the rubber composition”, the term “layer” is a layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition is a sheet Or “having a form of film”, “lamination” means “layer of thermoplastic resin or layer of thermoplastic elastomer composition” and layer of rubber composition at least partially directly superposed in their thickness direction Means that

The thickness of the layer of the unvulcanized rubber composition and the thickness of the layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition are not particularly limited. When the laminate of the present invention is used as an inner liner material for a pneumatic tire, the layer of a thermoplastic resin or the layer of a thermoplastic elastomer composition and the layer of a rubber composition exerts an effect as an inner liner material. It only needs to have a thickness that can be done. When the laminate of the present invention is used as an inner liner material for a pneumatic tire, the thickness of the layer of the thermoplastic resin or the layer of the thermoplastic elastomer composition is preferably 0.03 to
The thickness of the layer of the unvulcanized rubber composition is preferably 0.1 to 2.0 mm.

  A pneumatic tire can be manufactured by a conventional method using the laminate of the present invention. For example, the inner liner material made of the laminate of the present invention is placed on a tire molding drum such that the thermoplastic resin layer or the thermoplastic elastomer composition side of the laminate is directed to the tire molding drum. And a member used for ordinary tire production such as a carcass layer, a belt layer, a tread layer and the like made of unvulcanized rubber is sequentially laminated and molded thereon to form a green tire including the laminate of the present invention, Subsequently, a pneumatic tire can be manufactured by vulcanizing this green tire according to a conventional method.

(1) Preparation of Thermoplastic Elastomer Film The raw materials shown in the following Table 1 are melt-kneaded by the twin-screw kneading extruder at the ratio shown in the same table, and melted by the inflation molding apparatus connected to the discharge port of the twin-screw kneading extruder. The kneaded product was subjected to inflation molding to prepare a 0.2 mm thick thermoplastic elastomer film.

Raw material of film A:
BIMS: Brominated isobutylene-p-methylstyrene copolymer (Exxpro (registered trademark) 3035 manufactured by ExxonMobil Chemical Co., Ltd.)
Zinc oxide: Zinc white No. 3 manufactured by Shodomo Chemical Industry Co., Ltd. Stearic acid: industrial stearic acid manufactured by Chiba Fatty Acid Co., Ltd. Zinc stearate: Zinc stearate manufactured by NOF Co., Ltd. Thermoplastic resin: nylon 6 / 66 (Ube nylon (registered trademark) 5033B manufactured by Ube Industries, Ltd.)
Modified EEA: Maleic anhydride-modified ethylene-ethyl acrylate copolymer (Lilsan BESNOTL manufactured by Alcaire)
Plasticizer: BM-4 manufactured by Daihachi Chemical Industry Co., Ltd.

(2) Preparation of rubber composition The following raw materials were mix | blended with the Banbury mixer by the compounding ratio (mass part) shown to Table 2 and 3, and the rubber composition of Comparative Examples 1-18 and Examples 1-8 was prepared.
Raw material of rubber composition:
SBR: Nipol (registered trademark) 1502 manufactured by Nippon Zeon Co., Ltd.
NR: SIR-20
Carbon black: SEAST V manufactured by Tokai Carbon Co., Ltd.
Calcium carbonate: Heavy calcium carbonate (Super S, average primary particle size: 6.5 μm) manufactured by Maruo Calcium Co., Ltd.
Stearic acid: Industrial stearic acid from Chiba Fatty Acid Co., Ltd. Aroma oil: Desolex No. 3 from Showa Shell Petroleum Co., Ltd. Zinc oxide: Zinc oxide No. 3 from Shodomo Chemical Industry Co., Ltd. Modified resorcin-formaldehyde condensate Sumikanol 620 manufactured by Taoka Chemical Industry Co., Ltd.
Methylene donor: Modified etherified methylolmelamine resin (Sumikanol 507AP manufactured by Taoka Chemical Industry Co., Ltd.)
4-aminosalicylic acid (pK _a = 1.5 at _a temperature of 25 ° C.): Tokyo Chemical Industry Co., Ltd. o-aminobenzoic acid (pK _a = 2.0 at _a temperature of 25 ° C.): salicylic acid manufactured by Tokyo Chemical Industry Co., Ltd. _(pK a = 2.7 at a temperature _{25 ℃): (pK a =} 3.2 at a temperature 25 ° C.) Tokyo Chemical industry Co., Ltd. 2,4-dihydroxybenzoic acid: Tokyo Chemical industry Co., Ltd. benzoate ( PK _a = 4.0 at _a temperature of 25 ° C .: L-ascorbic acid manufactured by Tokyo Chemical Industry Co., Ltd. (pK _a = 4.2 at _a temperature of 25 ° C.): 3,4-dihydroxybenzoic acid manufactured by Tokyo Chemical Industry Co., Ltd. : (Temperature 25 ° C., pK _a = 4.3): Tokyo Chemical Industry Co., Ltd. product phenylpropionic acid: (temperature 25 ° C., pK _a = 4.4): Tokyo Chemical Industry Co., Ltd. sulfur: Co., Ltd. Karuizawa Refinery's 5% oil-treated sulfur vulcanization accelerator: di-2-benzothiazolyl Disulfide (Noccellar DM manufactured by Ouchi Shinko Chemical Co., Ltd.)

(3) Production of Laminate On the thermoplastic elastomer film produced in the above (1), the rubber composition prepared in the above (2) was extruded at a thickness of 0.7 mm to produce a laminate.

(4) Evaluation of Laminate The laminates of Examples and Comparative Examples produced as described above were evaluated by the following peel strength test and heat generation test. The evaluation results are shown in Tables 2 and 3.
[Peeling strength test]
The laminate was vulcanized at 170 ° C. for 10 minutes under a pressure of 4.0 MPa with a press. Strip test pieces of 125 mm in length and 25 mm in width are cut out from the vulcanized laminate, and the peel strength (N / 25 mm) between the thermoplastic elastomer layer and the rubber composition layer of the strip test pieces is in accordance with JIS K6256-1 It was measured. The measurement results of the peel strengths of Comparative Examples 2 to 18 and Examples 1 to 8 are shown in Tables 2 and 3 below as relative values when the measured value of Comparative Example 1 is 1.
[Heat test]
The laminate was vulcanized at 170 ° C. for 10 minutes under a pressure of 4.0 MPa in a press. JIS No. 2 dumbbell-shaped test pieces are punched out of the vulcanized laminate, and the obtained test pieces are initially strained 0%, amplitude ± 20%, using a viscoelastic constant strain fatigue tester manufactured by Ueshima Seisakusho Co., Ltd. The temperature change before and after the cyclic strain test at room temperature (23 ° C.) was measured by a radiation thermometer (a portable small thermal imaging camera CPA-E50 manufactured by CHINO Corporation) manufactured by FLIR Systems. The measurement results for Comparative Examples 2 to 18 and Examples 1 to 8 are shown in Tables 2 and 3 below as relative values when the value of Comparative Example 1 is 100. The smaller the index of heat buildup means that the heat buildup is smaller, that is, a pneumatic tire with lower rolling resistance can be provided.

  From the test results of peel strength and heat buildup shown in Table 2 and Table 3, according to the present invention, high peel strength between the thermoplastic resin film and the layer of the rubber composition is improved, and the rubber composition is also obtained. It can be seen that the heat buildup of the layer is reduced.

  The laminate of the present invention is useful as an inner liner material for a pneumatic tire, and can be suitably used for the production of a pneumatic tire. The pneumatic tire including the inner liner material made of the laminate of the present invention can be suitably used as a tire for an automobile.

Claims (9)

A laminate for a pneumatic tire comprising an unvulcanized rubber composition layer and a thermoplastic resin layer or a thermoplastic elastomer composition layer, wherein the unvulcanized rubber composition is
(A) rubber component,
(B) 0.5 to 20 parts by mass of the following formula (1): 100 parts by mass of the rubber component (A):

(Wherein, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group having 1 to 8 carbon atoms, and the number of carbon atoms Independently selected from the group consisting of 1 to 8 alkoxide groups)
A condensate of a substituted or unsubstituted phenolic compound represented by
(C) 0.25 to 200 parts by mass of methylene donor with respect to 100 parts by mass of the rubber component (A)
(D) 0.5 to 5 parts by mass, per 100 parts by mass of the rubber component (A), a substituted or unsubstituted aromatic carboxylic acid having a pKa of 1.5 to 4.0 at a temperature of 25 ° C.
(E) 20 to 100 parts by mass of calcium carbonate, per 100 parts by mass of the rubber component (A)
(F) 0 to 20 parts by mass of carbon black with respect to 100 parts by mass of the rubber component (A), and (G) a vulcanizing agent,
A laminate for a pneumatic tire, comprising: and a mass ratio of methylene donor (C) to condensation product (B) is 0.5: 1 to 10: 1.   The laminate according to claim 1, wherein the calcium carbonate has an average primary particle size of 10 μm or less.   The thermoplastic resin is selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD 6, and nylon 6 T. The laminate according to claim 1, which is at least one selected.   The thermoplastic elastomer composition comprises a thermoplastic resin component and an elastomer component dispersed in the thermoplastic resin component, and the thermoplastic resin component is polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, At least one thermoplastic resin selected from the group consisting of nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD 6 and nylon 6 T, the elastomer component being a brominated isobutylene- At least one selected from the group consisting of p-methylstyrene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer and maleic anhydride-modified ethylene-ethyl acrylate copolymer Claim 1 or including Laminate according to.   The methylene donor (C) is at least one selected from the group consisting of modified etherified methylolmelamine, paraformaldehyde, hexamethylenetetramine, pentamethylenetetramine, and hexamethoxymethylmelamine. The layered product according to one item. The condensate (B) is represented by the formula (2):

(Wherein n is an integer of 1 to 20); or Formula (3):

(Wherein, m is an integer of 1 to 20)
The laminated body as described in any one of Claims 1-5 represented by these.   The laminate according to any one of claims 1 to 6, wherein the rubber component (A) is a diene rubber.   The inner-liner material for pneumatic tires which consists of a laminated body as described in any one of Claims 1-7. A process of forming a green tire including the inner liner material according to claim 8, a process of vulcanizing the green tire,
A method of manufacturing a pneumatic tire including: