JP2019130689A - Laminated sheet, inner liner material and pneumatic tire - Google Patents

Abstract

To provide a laminated sheet of a thermoplastic film and a tie rubber layer, with improved adhesion between the thermoplastic film and the tie rubber layer.SOLUTION: The present invention provides a laminated sheet of a thermoplastic film (A) and a tie rubber layer (B). The thermoplastic film (A) and the tie rubber layer (B) are laminated through (C) a tack layer having a material or composition that is 10-100 μm in thickness and has an adhesiveness of 500-2000 g measured by a tack test.SELECTED DRAWING: None

Description

  The present invention relates to a laminated sheet, an inner liner material, and a pneumatic tire. More specifically, the present invention relates to a laminated sheet of a thermoplastic film and a tie rubber layer, an inner liner material for a pneumatic tire comprising the laminated sheet, and a pneumatic tire including the laminated sheet.

  A technique using a thermoplastic film for an inner liner of a pneumatic tire is known, but the thermoplastic film is inferior in adhesion to a tie rubber layer. Therefore, in order to strengthen the adhesion between the thermoplastic film and the tie rubber layer, the thermoplastic film is a thermoplastic film constituting the thermoplastic film such as an epoxy-modified styrene-butadiene-styrene block copolymer between the tie rubber layer. A technique for providing a layer of an adhesive composition containing an adhesive that can react with a resin or a thermoplastic elastomer and a tackifier is known (Patent Documents 1 and 2).

International Publication No. 2006/121140 International Publication No. 2007/100021

However, the techniques described in Patent Document 1 and Patent Document 2 have a problem that an equipment that does not react a material that reacts and adheres during tire vulcanization even at a film forming temperature higher than the tire vulcanization temperature is required. .
Moreover, in order to reinforce the adhesive force between the thermoplastic film and the tie rubber layer without providing a layer of an adhesive composition containing an adhesive capable of reacting with the thermoplastic resin or thermoplastic elastomer constituting the thermoplastic film. In addition, when the adhesive component is blended with the thermoplastic film, the desired film physical properties cannot be obtained, or the film formability is deteriorated. When sufficient adhesiveness with the thermoplastic film is imparted to the tie rubber, the rubber mixture, There is a problem that the sheet formability of tie rubber deteriorates.
The present invention relates to a laminated sheet of a thermoplastic film and a tie rubber layer used as an inner liner material for a pneumatic tire, and an adhesive that includes an adhesive capable of reacting with a thermoplastic resin or a thermoplastic elastomer constituting the thermoplastic film. It is an object of the present invention to provide a laminated sheet having excellent adhesive force between a thermoplastic film and a tie rubber layer without providing a layer of the agent composition.

  The present inventor has found that a laminated sheet having excellent adhesion can be obtained while satisfying good film physical properties and rubber processability by arranging a tack layer between the thermoplastic film and the tie rubber layer. Completed the invention.

The present invention is a laminated sheet of a thermoplastic film (A) and a tie rubber layer (B),
The thermoplastic film (A) and the tie rubber layer (B) are laminated via the tack layer (C),
The tack layer (C) is characterized in that it has a thickness of 10 to 100 μm and is made of a substance or composition having an adhesive force measured by a tack tester of 500 to 2000 g.

The present invention includes the following aspects.
[1] A laminated sheet of a thermoplastic film (A) and a tie rubber layer (B),
The thermoplastic film (A) and the tie rubber layer (B) are laminated via the tack layer (C),
The tack layer (C) is a laminated sheet having a thickness of 10 to 100 μm and made of a substance or composition having an adhesive force measured by a tack test of 500 to 2000 g.
[2] The laminated sheet according to [1], wherein the tack layer (C) includes a tackifier.
[3] The laminated sheet according to [1] or [2], wherein the tack layer (C) is a coating film of an aqueous solution or an aqueous dispersion containing a tackifier.
[4] The laminated sheet according to [1] or [2], wherein the tack layer (C) is a melt-extruded layer of a tackifier or a composition containing a tackifier.
[5] The laminated sheet according to any one of [1] to [4], wherein the thermoplastic film (A) includes a thermoplastic elastomer composition or a thermoplastic resin.
[6] The laminated sheet according to [5], wherein the thermoplastic elastomer composition includes a matrix composed of a thermoplastic resin component and a dispersed phase composed of an elastomer component dispersed in the matrix.
[7] The laminated sheet according to any one of [1] to [6], wherein the tie rubber layer (B) includes a rubber component, a phenol / formaldehyde condensate, and a methylene donor.
[8] An inner liner material for a pneumatic tire comprising the laminated sheet according to any one of [1] to [7].
[9] A pneumatic tire including the laminated sheet according to any one of [1] to [7].

  The laminated sheet of the present invention is excellent in the adhesive force between the thermoplastic film and the tie rubber layer.

The present invention is a laminated sheet of a thermoplastic film (A) and a tie rubber layer (B), and the thermoplastic film (A) and a tie rubber layer (B) are laminated via a tack layer (C). .
The tack layer (C) is made of a substance or composition having a thickness of 10 to 100 μm and an adhesive strength measured by a tack test of 500 to 2000 g.

By providing the tack layer (C) having a thickness of 10 to 100 μm, there is an effect of obtaining good tire moldability while maintaining good film adhesion.
The thickness of the tack layer (C) is 10 to 100 μm, preferably 15 to 90 μm, and more preferably 20 to 80 μm. If the thickness of the tack layer (C) is too thin, the film cannot be held on the inner surface of the tire during molding of the tire, and if it is too thick, the adhesion to the film is deteriorated.

  The substance or composition constituting the tack layer (C) has an adhesive strength measured by a tack test of 500 to 2000 g, preferably 800 to 2000 g, and more preferably 1000 to 2000 g. If the adhesive strength is too small, the film cannot be held on the inner surface of the tire during the molding of the tire, and if it is too large, the film becomes too close and workability deteriorates.

  In addition, the adhesive force measured by the tack test means an adhesive force measured using a PICMA tack tester manufactured by Toyo Seiki Co., Ltd. under an atmosphere of a room temperature of 25 ° C. and a humidity of 60% under a pressure bonding speed of 500 mm / min.

  Examples of the substance or composition having an adhesive strength measured by a tack test of 500 to 2000 g include a tackifier or a composition containing a tackifier. Specific examples of the tackifier include liquid rubber, C9 petroleum resin, C5 petroleum resin, terpene resin, coumarone resin, coumarone indene oil, rosin ester, hydrogenated rosin ester, alkylphenol resin, and DCPD. Examples of the composition containing a tackifier include blending the tackifier into a thermoplastic resin or a thermoplastic elastomer. That is, the tack layer (C) preferably contains a tackifier.

  The tack layer (C) is formed by, for example, applying an aqueous solution or aqueous dispersion containing a tackifier to the thermoplastic film (A) or the tie rubber layer (B), or a composition containing the tackifier or tackifier. Can be produced by melt extrusion. That is, the tack layer (C) is preferably a melt-extruded layer of an aqueous solution or aqueous dispersion containing a tackifier or a composition containing a tackifier or tackifier.

The tackifier used when the tack layer (C) is produced by coating is preferably an emulsion tackifier.
When using the aqueous solution containing a tackifier, the concentration of the tackifier in the aqueous solution is preferably 5 to 30% by mass, more preferably 5 to 20% by mass, and further preferably 10 to 20% by mass. is there. If the concentration is too low, uniform coating is difficult, and if it is too high, control of the thickness becomes difficult.
Specific examples of the aqueous dispersion containing a tackifier include polyvinyl alcohol and polyester. The concentration of the tackifier in the aqueous dispersion is preferably 5 to 30% by mass, more preferably 5 to 20% by mass, and still more preferably 10 to 20% by mass. If the concentration is too low, uniform coating is difficult, and if it is too high, it becomes difficult to control the thickness.

The tackifier used when the tack layer (C) is produced by melt extrusion is preferably a terpene phenol resin.
The method of melt extrusion is not particularly limited. For example, a melted tackifier or a composition containing a melted tackifier may be extruded from a T-die onto a thermoplastic film.

  The thermoplastic film (A) is not limited as long as it can function as an inner liner material of a pneumatic tire, but is preferably a film made of a thermoplastic resin or a thermoplastic elastomer composition.

Examples of thermoplastic resins include polyamide resins, polyester resins, polynitrile resins, polymethacrylate resins, polyvinyl resins, cellulose resins, fluorine resins, imide resins, polystyrene resins, polyolefin resins, and the like. Can do.
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, Examples include nylon 9T, nylon 66 / PP copolymer, nylon 66 / PPS copolymer, and the like.
Polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, And aromatic polyesters 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, and the like. .
Examples of the polymethacrylate resin include polymethyl methacrylate (PMMA) and polyethyl methacrylate.
Polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), polyvinyl chloride / vinylidene chloride Examples thereof include a polymer and a vinylidene chloride / methyl acrylate copolymer.
Examples of the cellulose resin include cellulose acetate and cellulose acetate butyrate.
Examples of the fluorine-based resin include polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), and tetrafluoroethylene / ethylene copolymer (ETFE).
Examples of the imide resin include aromatic polyimide (PI). Examples of the polystyrene resin include polystyrene (PS).
Examples of the polyolefin resin 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 MXD6, nylon 6T are fatigue resistant and air blocking. It is preferable in terms of compatibility of sex.

  Thermoplastic resins are commonly used in resin compositions such as fillers, reinforcing agents, processing aids, stabilizers, and antioxidants to improve processability, dispersibility, heat resistance, and antioxidant properties. You may mix | blend the compounding agent mix | blended with in the range which does not inhibit the effect of this invention. The plasticizer should not be blended from the viewpoints of air barrier properties and heat resistance, but may be blended as long as the effects of the present invention are not impaired.

  In the present invention, the thermoplastic elastomer composition is a composition in which an elastomer component is dispersed in a thermoplastic resin component, more specifically, a matrix composed of a thermoplastic resin component and an elastomer component dispersed in the matrix. It consists of a dispersed phase.

  As a thermoplastic resin component which comprises a thermoplastic elastomer composition, the same thing as the said thermoplastic resin can be used.

Examples of the elastomer component constituting the thermoplastic elastomer composition include diene rubber and hydrogenated product thereof, olefin rubber, halogen-containing rubber, silicone rubber, sulfur-containing rubber, and fluorine rubber.
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), Examples thereof include acrylonitrile butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, and the like.
Examples of the olefin rubber 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-glycidyl methacrylate. Examples thereof include a copolymer, a maleic anhydride-modified ethylene-ethyl acrylate copolymer (modified EEA), a butyl rubber (IIR), an isobutylene and aromatic vinyl or diene monomer copolymer, an acrylic rubber (ACM), and an ionomer.
Examples of the halogen-containing rubber include halogenated butyl rubbers such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR), halogenated isomonoolefin-p-alkylstyrene copolymers (for example, brominated isobutylene-p-). Methylstyrene copolymer (BIMS)), halogenated isobutylene-isoprene copolymer rubber, chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorination Examples thereof include polyethylene (M-CM).
Examples of the silicone rubber include methyl vinyl silicone rubber, dimethyl silicone rubber, and methyl phenyl vinyl silicone rubber. Examples of the sulfur-containing rubber include polysulfide rubber. Examples of the fluorine rubber include vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicone rubber, and fluorine-containing phosphazene rubber.
Among them, halogenated isomonoolefin-p-alkylstyrene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer, maleic anhydride-modified ethylene-ethyl acrylate copolymer are available. From the viewpoint of air barrier properties, it is preferable.

  For the elastomer component, other reinforcing agents (fillers) such as carbon black and silica, softeners, anti-aging agents, processing aids and the like are generally added to the rubber composition. You may mix | blend in the range which does not inhibit.

  The combination of the elastomer component and the thermoplastic resin component constituting the thermoplastic elastomer composition is not limited, but halogenated butyl rubber and polyamide 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, amorphous butadiene rubber and syndiotactic poly (1,2-polybutadiene), amorphous isoprene rubber and transpoly (1,4-isoprene), fluororubber and fluororesin, and the like, but the combination of butyl rubber and polyamide resin with excellent air barrier properties is preferred. In particular, a combination of a brominated isobutylene-p-methylstyrene copolymer rubber, which is a modified butyl rubber, and nylon 6/66 or nylon 6 or a blend resin of nylon 6/66 and nylon 6 provides fatigue resistance and air blocking. It is particularly preferable from the viewpoint of compatibility.

  The thermoplastic elastomer composition is obtained by melt-kneading a thermoplastic resin component and an elastomer component with, for example, a twin-screw kneading extruder to disperse the elastomer component as a dispersed phase in the thermoplastic resin component forming a matrix phase. Can be manufactured. The mass ratio of the thermoplastic resin component and the elastomer component is not limited, but is preferably 10/90 to 90/10, more preferably 15/85 to 90/10.

  The thermoplastic resin or the thermoplastic elastomer composition can contain various additives as long as the effects of the present invention are not impaired.

The tie rubber layer (B) is a layer interposed between the thermoplastic film and the rubber member in order to improve adhesion between the thermoplastic film and a rubber member used for manufacturing a normal tire such as a carcass layer. .
As the rubber composition constituting the tie rubber layer (B), a rubber composition conventionally used as a tie rubber layer in a pneumatic tire can be used. Preferably, a rubber component, a phenol / formaldehyde condensate and A rubber composition containing a methylene donor.

The rubber component constituting the rubber composition is not particularly limited, and examples thereof include diene rubber and hydrogenated products thereof, olefin rubber, halogen-containing rubber, silicone rubber, sulfur-containing rubber, and fluorine rubber.
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), Examples thereof include acrylonitrile butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, and the like.
Examples of the olefin rubber 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-glycidyl methacrylate. Examples thereof include a copolymer, a maleic anhydride-modified ethylene-ethyl acrylate copolymer (modified EEA), a butyl rubber (IIR), an isobutylene and aromatic vinyl or diene monomer copolymer, an acrylic rubber (ACM), and an ionomer.
Examples of the halogen-containing rubber include halogenated butyl rubbers such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR), halogenated isomonoolefin-p-alkylstyrene copolymers (for example, brominated isobutylene-p-). Methylstyrene copolymer (BIMS)), halogenated isobutylene-isoprene copolymer rubber, chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorination Examples thereof include polyethylene (M-CM).
Examples of the silicone rubber include methyl vinyl silicone rubber, dimethyl silicone rubber, and methyl phenyl vinyl silicone rubber. Examples of the sulfur-containing rubber include polysulfide rubber.
Examples of the fluorine rubber include vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicone rubber, and fluorine-containing phosphazene rubber.
Of these, diene rubber, olefin rubber, and halogen-containing rubber are preferable from the viewpoint of co-crosslinking properties with adjacent rubber materials, and more preferably natural rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, halogenated rubber. Butyl rubber is a mixture thereof, more preferably a combination of natural rubber and styrene butadiene rubber, a combination of natural rubber and butadiene rubber, a combination of natural rubber and butyl rubber, a combination of natural rubber and halogenated butyl rubber, or the like.

  In the present invention, the phenol / formaldehyde condensate refers to a condensate of the compound represented by the formula (1) and formaldehyde.

In formula (1), R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represent hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, or 1 to 1 carbon atoms. Eight alkoxy groups.

One preferred 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 an alkyl group having 1 to 8 carbon atoms, and the rest is It is hydrogen or an alkyl group having 1 to 8 carbon atoms. A preferred specific example of the compound represented by the formula (1) is cresol.
Another preferred 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 1 to 8 carbon atoms. Is an alkyl group. Another preferred specific example of the compound represented by the formula (1) is resorcinol (also referred to as “resorcin”).

  Examples of the condensate of the compound represented by the formula (1) and formaldehyde include a cresol / formaldehyde condensate and a resorcin / formaldehyde condensate. Moreover, these condensates may be modified as long as the effects of the present invention are not impaired. For example, a modified resorcin / formaldehyde condensate modified with an epoxy compound can also be used in the present invention. These condensates are commercially available, and commercially available products can be used in the present invention.

  The condensate of the compound represented by formula (1) and formaldehyde is preferably a compound represented by formula (2) or formula (3).

  In Formula (2), n is an integer of 1-20, Preferably it is an integer of 1-10, More preferably, it is an integer of 1-5.

  In Formula (3), m is an integer of 1-20, Preferably it is an integer of 1-10, More preferably, it is an integer of 1-3.

  The compounding amount of the condensate of the compound represented by formula (1) and formaldehyde (hereinafter also simply referred to as “condensate”) is 0.5 to 20 parts by mass with respect to 100 parts by mass of the rubber component, Preferably it is 1-10 mass parts. If the amount of the condensate is too small, the amount of heat and time required to obtain good adhesion will increase and the vulcanization efficiency will deteriorate. Conversely, if the amount is too large, the vulcanization elongation of the resulting rubber composition will be impaired. It becomes easy to break.

  The methylene donor refers to a base compound that generates formaldehyde by heating or the like, for example, hexamethylenetetramine, pentamethylenetetramine, hexamethylenediamine, methylolmelamine, etherified methylolmelamine, modified etherified methylolmelamine, esterified methylolmelamine, Hexamethoxymethylol melamine, hexamethylol melamine, hexakis (ethoxymethyl) melamine, hexakis (methoxymethyl) melamine, N, N ', N "-trimethyl-N, N', N" -trimethylol melamine, N, N ', N "-trimethylol melamine, N-methylol melamine, N, N'-bis (methoxymethyl) melamine, N, N ', N" -tributyl-N, N', N "-trimethylol melamine, paraforma Dehydro, and the like. Among them, from the viewpoint of the discharge temperature of formaldehyde, preferably modified etherified methylol melamine.

  The compounding amount of the methylene donor is 0.25 to 200 parts by mass, preferably 0.5 to 80 parts by mass, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the rubber component. If the amount of methylene donor is too small, the methylene donor is consumed in the resin reaction in the rubber composition system, the reaction in the interfacial reaction does not proceed, and the adhesion deteriorates. On the other hand, when the amount is too large, the reaction in the rubber composition system is promoted too much, or the cross-linking reaction in the resin system to be adhered is induced to deteriorate the adhesion.

  The ratio of the amount of methylene donor to the amount of condensate is preferably 0.5 to 10, more preferably 1 to 4 parts by mass, and even more preferably 1 to 3. If this ratio is too small, the donor is consumed in the resin reaction in the rubber composition system, and the reaction in the interfacial reaction does not proceed, resulting in poor adhesion. On the other hand, if it is too large, the reaction in the rubber composition system is promoted too much, or the cross-linking reaction in the resin system to be deposited is induced to deteriorate the adhesion.

The rubber composition preferably contains a vulcanizing agent.
Examples of vulcanizing agents include inorganic vulcanizing agents and organic vulcanizing agents. Examples of inorganic vulcanizing agents include sulfur, sulfur monochloride, selenium, tellurium, zinc oxide, magnesium oxide, and lead monoxide. Examples of organic vulcanizing agents include sulfur-containing organic compounds, dithiocarbamates, oximes, tetrachloro-p-benzoquinone, dinitroso compounds, modified phenolic resins, polyamines, and organic peroxides. Of these, sulfur, organic peroxides such as 1,3-bis (t-butylperoxyisopropyl) benzene, modified phenol resins such as brominated alkylphenol / formaldehyde condensates, zinc oxide, and sulfur-containing organic compounds are preferred.

  The compounding amount of the vulcanizing agent is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and further preferably 0.5 to 5 parts with respect to 100 parts by mass of the rubber component. Part by mass. If the amount of the vulcanizing agent is too small, the strength of the rubber is reduced, and as a result, good adhesiveness is not exhibited. If the amount of the vulcanizing agent is too large, the adhesion reaction between the rubber and the film is hindered.

The rubber composition may further contain a vulcanization accelerator.
Examples of the vulcanization accelerator include aldehyde / ammonia, aldehyde / amine, thiourea, guanidine, thiazole, sulfenamide, thiuram, dithiocarbamate, xanthate, and preferably thiazole. System, sulfenamide system, thiuram system.

  The blending amount of the vulcanization accelerator is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and further preferably 0.5 to 100 parts by mass with respect to 100 parts by mass of the rubber component. 5 parts by mass. If the blending amount of the vulcanization accelerator is too small, the vulcanization reaction is not completed within the desired vulcanization time, so that the rubber strength is reduced and as a result, good adhesion is not exhibited. When the amount of the vulcanization accelerator is too large, the adhesion reaction between the rubber and the film is inhibited.

  The laminated sheet of the present invention can be produced by laminating a rubber composition for a tie rubber layer on a thermoplastic film via a tack layer. Although it does not limit, more specifically, it can manufacture as follows. First, a thermoplastic resin or a thermoplastic elastomer composition is molded into a film shape by a molding apparatus such as an inflation molding apparatus or a T-die extruder to produce a thermoplastic film. The rubber composition for the tie rubber layer is calendered and formed into a sheet shape to produce a rubber composition sheet. An aqueous solution or aqueous dispersion containing a tackifier is applied to the thermoplastic film, or a composition containing the tackifier or tackifier is melt-extruded to form a tack layer. Alternatively, a thermoplastic film or a thermoplastic elastomer composition and a tackifier or a composition containing a tackifier can be coextruded to produce a thermoplastic film having a tack layer. Next, a laminated sheet can be obtained by laminating the rubber composition sheet on the tack layer forming surface of the thermoplastic film.

The laminated sheet of the present invention can be used as an inner liner material for a pneumatic tire.
The present invention is also an inner liner material for a pneumatic tire comprising the laminated sheet.

The present invention is also a pneumatic tire including the laminated sheet.
The pneumatic tire of the present invention can be manufactured by a conventional method. For example, the laminated sheet of the present invention is placed on a tire molding drum as an inner liner material so that the film side of the thermoplastic resin or thermoplastic elastomer composition faces the tire molding drum, and the unvulcanized sheet is placed thereon. Rubber tire carcass layer, belt layer, tread layer and other members used in normal tire production are laminated one after another. After molding, the drum is pulled out to make a green tire. By doing so, a pneumatic tire can be manufactured.

(1) Preparation of composition for thermoplastic film The following raw materials were blended in the ratios shown in Table 1 to prepare thermoplastic film compositions a1 and a2.
BIMS: Brominated isobutylene-p-methylstyrene copolymer “EXXPRO” (registered trademark) 3035 manufactured by ExxonMobil Chemical Co., Ltd.
Zinc oxide: Zohua Chemical Industry Co., Ltd., Zinc Hana No. 3 Stearic acid: Industrial Nippon Steika Chemical Co., Ltd. Zinc stearate: NOF Co., Ltd. zinc stearate Nylon 6/66: Ube Industries, Ltd. UBE nylon "5033B
Modified EEA: Maleic anhydride modified ethylene-ethyl acrylate copolymer “Rilsan” (registered trademark) BESN O TL manufactured by Arkema
Plasticizer: N-Butylbenzenesulfonamide “BM-4” manufactured by Daihachi Chemical Industry Co., Ltd.
Tackifier: Terpene phenol resin “YS Polystar T100” manufactured by Yasuhara Chemical Co., Ltd.

(2) Preparation of composition for tie rubber layer The following raw materials were blended in the ratios shown in Table 2 to prepare tie rubber layer compositions b1 and b2.
Styrene butadiene rubber: “Nipol 1502” manufactured by Nippon Zeon Co., Ltd.
Natural rubber: SIR-20
Carbon Black: “Seast V” manufactured by Tokai Carbon Co., Ltd.
Stearic acid: Industrial stearic acid manufactured by Nippon Nippon Chemical Co., Ltd. Aroma oil: “Desolex No. 3” manufactured by Showa Shell Sekiyu KK
Zinc oxide: Zinc Hana 3 manufactured by Shodo Chemical Industry Co., Ltd. Modified resorcin / formaldehyde condensate: “Sumikanol 620” manufactured by Taoka Chemical Co., Ltd.
Methylene donor: Modified etherified methylol melamine “Sumikanol 507AP” manufactured by Taoka Chemical Co., Ltd.
Tackifier: Terpene phenol resin “YS Polystar T100” manufactured by Yasuhara Chemical Co., Ltd.
Sulfur: 5% oil-extended sulfur from Tsurumi Chemical Industry Co., Ltd. Vulcanization accelerator: Di-2-benzothiazolyl disulfide “Noxeller DM” from Ouchi Shinsei Chemical Co., Ltd.

(3) Preparation of Tack Layer Composition The following raw materials were blended in the ratios shown in Table 3 to prepare two types of tack layer compositions c1 and c2.
NH-18: “GOHSENOL NH-18” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
Tuffprene A: “Tuffprene A” manufactured by Asahi Kasei Corporation
YS Polystar T100: Terpene phenol resin tackifier manufactured by Yasuhara Chemical Co., Ltd. Superester E-720: “Superester E-720” manufactured by Arakawa Chemical Industries, Ltd.

Example 1
The composition a1 for thermoplastic films was shape | molded with the inflation shaping | molding apparatus, and 0.1-mm-thick thermoplastic film A1 was produced. The tie rubber layer composition b1 was formed into a sheet by calendering to produce a tie rubber layer B1 having a thickness of 0.7 mm. A tack layer composition C1 was applied to the produced thermoplastic film A1, dried, and provided with a tack layer C1 having a thickness of 80 μm. Next, a tie rubber layer B1 was laminated on the tack layer C1 side to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4.

Example 2
The tack layer composition c2 was melt-extruded to the thermoplastic film A1 produced in Example 1 to provide a tack layer C2 having a thickness of 80 μm. Next, the tie rubber layer B1 produced in Example 1 was laminated on the tack layer C1 side to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4.

Comparative Example 1
The thermoplastic film A1 and the tie rubber layer B1 were laminated without providing a tack layer to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4. If the tack layer is not provided, the tire moldability is poor.

Comparative Example 2
The tie rubber layer composition b2 was formed into a sheet by calendering to produce a tie rubber layer B2 having a thickness of 0.7 mm. However, it was difficult to remove the tie rubber layer composition b2 from the Banbury mixer, and for the tie rubber layer Composition b2 stuck to the calender roll and was difficult to remove. The thermoplastic film A1 produced in Example 1 and the tie rubber layer B2 were laminated without providing a tack layer to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4. When a tackifier is added to the tie rubber layer, the tire moldability is good without providing a tack layer, but the tie rubber layer composition to which the tackifier is added has poor processability.

Comparative Example 3
The thermoplastic film composition a2 was molded with an inflation molding apparatus to produce a thermoplastic film A2 having a thickness of 0.1 mm, but the inflation molding was very difficult. The thermoplastic film A2 and the tie rubber layer B1 produced in Example 1 were laminated without providing a tack layer to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4. When a tackifier is added to the thermoplastic film, the tire moldability is good without providing a tack layer, but the thermoplastic film composition to which the tackifier is added has poor moldability.

Comparative Example 4
The thermoplastic film A2 produced in Comparative Example 3 and the tie rubber layer B2 produced in Comparative Example 2 were laminated without providing a tack layer to produce a laminated sheet. About the obtained lamination sheet, the tire moldability was evaluated. The evaluation results are shown in Table 4. When a tackifier is added to the thermoplastic film and the tie rubber layer, the tire moldability is good without providing a tack layer, but the composition for a thermoplastic film to which a tackifier is added has poor moldability. The tie rubber layer composition to which a tackifier is added has poor processability.

[Tack test]
Using a PICMA tack tester manufactured by Toyo Seiki Co., Ltd., the adhesive strength was measured under a pressure bonding speed of 500 mm / min under an atmosphere of room temperature of 25 ° C. and humidity of 60%.

[Evaluation of moldability of thermoplastic film]
When the composition for a thermoplastic film is molded by an inflation molding apparatus to produce a thermoplastic film, the case where the molding can be carried out without hindrance is indicated by ◯, and the case where the inflation molding is difficult is indicated by x.

[Evaluation of tie rubber layer processability]
When the composition for tie rubber layer is kneaded with a Banbury mixer and formed into a sheet by calendering, the case where the molding can be carried out without any trouble is indicated by ○, and the composition for tie rubber layer is taken out from the Banbury mixer. The case where it is difficult to remove or the tie rubber layer composition sticks to the calendar roll and is difficult to take is indicated by x.

[Evaluation of tire formability]
20 tires were prepared using the prepared laminate, and rubber / film interlayer air before vulcanization due to excessive molding or insufficient adhesion between film molding and tire vulcanization, or film tire The case where peeling from the inner surface was not confirmed is indicated by ◯, and the confirmed case is indicated by ×.

  The laminated sheet of the present invention can be suitably used as an inner liner material for a pneumatic tire.

Claims (9)

A laminated sheet of a thermoplastic film (A) and a tie rubber layer (B),
The thermoplastic film (A) and the tie rubber layer (B) are laminated via the tack layer (C),
The tack layer (C) is a laminated sheet having a thickness of 10 to 100 μm and made of a substance or composition having an adhesive force measured by a tack test of 500 to 2000 g.   The laminated sheet according to claim 1, wherein the tack layer (C) contains a tackifier.   The laminated sheet according to claim 1 or 2, wherein the tack layer (C) is a coating film of an aqueous solution or an aqueous dispersion containing a tackifier.   The laminated sheet according to claim 1 or 2, wherein the tack layer (C) is a melt-extruded layer of a tackifier or a composition containing a tackifier.   The laminated sheet according to any one of claims 1 to 4, wherein the thermoplastic film (A) comprises a thermoplastic elastomer composition or a thermoplastic resin.   The laminated sheet according to claim 5, wherein the thermoplastic elastomer composition includes a matrix composed of a thermoplastic resin component and a dispersed phase composed of an elastomer component dispersed in the matrix.   The laminated sheet according to any one of claims 1 to 6, wherein the tie rubber layer (B) contains a rubber component, a phenol / formaldehyde condensate and a methylene donor.   The innerliner material for pneumatic tires which consists of a laminated sheet of any one of Claims 1-7.   A pneumatic tire comprising the laminated sheet according to claim 1.