JP2013154848A - Tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire in which a colored layer is hardly changeable after a long time usage, and the degree of freedom of color is high and superior in fashionability.SOLUTION: A tire includes: a side rubber 7 arranged in a sidewall section 2; a colored layer 8 arranged in a tire width direction outside of the side rubber 7; and a thermoplastic film layer 9 arranged between the side rubber 7 and the colored layer 8. In the tire, it is desired for the thermoplastic film layer 9 that an oxygen permeation rate is 3.0×10cm.cm/cm.sec.cmHg or less at 20 °C and 65% RH.

Description

  The present invention relates to a tire, in particular, a pneumatic tire in which a colored layer is formed on the outer side in the tire width direction of a side rubber of a sidewall portion.

  Conventionally, as with other molded products, a coloring process such as painting and printing on a surface has been widely performed for tires in order to improve decoration and visibility. For example, Japanese Patent Application Laid-Open No. 2010-125440 discloses a method of decorating a tire with ultraviolet curable ink. In addition, Japanese Patent Publication No. 2004-526814 and Japanese Patent Publication No. 2009-520616 disclose a tire in which a colored layer made of a polyurethane layer is provided on a sidewall portion.

  On the other hand, in order to improve the fashionability and the like of the tire, a technique for disposing a film layer on the sidewall portion of the tire is known. For example, Japanese Patent Application Laid-Open No. 2010-111351 discloses a natural rubber, Titanium dioxide is blended with the thermoplastic resin through a rubber layer formed by blending at least one rubber component selected from the three types of butyl rubber, halogenated butyl rubber, and ethylene-propylene-diene terpolymer. A tire provided with a film layer is disclosed. JP-A-56-90704, Japanese Utility Model Laid-Open No. 58-175042, etc. disclose a tire in which a film layer is provided on the outer layer of the tire for the purpose of preventing contamination of the colored rubber by an anti-aging agent. It is disclosed.

JP 2010-125440 A JP-T-2004-526814 Special table 2009-520616 JP 2010-111351 A JP 56-90704 A Japanese Utility Model Publication No. 58-175042

  By the way, an anti-aging agent or the like is generally added to the rubber composition for the side rubber disposed in the sidewall portion of the tire for the purpose of preventing deterioration due to ozone or ultraviolet rays. It is known that it gradually shifts to the tire surface over time and use. And when a colored layer is formed on such a side rubber for the purpose of decoration or improvement of visibility, the anti-aging agent blended in the rubber composition for the side rubber during long-term use. There was a problem of being contaminated. On the other hand, in order to prevent contamination, if the thickness of the colored layer is increased to ensure the contamination distance, there is a problem that the tire weight increases and the rolling resistance of the tire increases. Moreover, in the tire which provided the film layer in the outermost layer of the tire without providing the colored layer, the degree of freedom in color was low and the fashionability was insufficient.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a tire that has a high degree of freedom in color and excellent fashionability, as well as having a colored layer that is difficult to discolor even after long-term use.

  As a result of intensive studies to achieve the above object, the present inventors interpolated a thermoplastic film layer between the side rubber and the colored layer in the tire in which the colored layer is disposed on the outer side in the tire width direction of the side rubber. Thus, the colored layer is difficult to discolor, and furthermore, the tire has a high degree of freedom in color and is excellent in fashionability, and the present invention has been completed.

  That is, the tire of the present invention includes a side rubber disposed on the sidewall portion, a colored layer disposed on the outer side in the tire width direction of the side rubber, and a heat disposed between the side rubber and the colored layer. And a plastic film layer. Such a tire of the present invention has a high degree of freedom in color, is excellent in fashionability, and the colored layer is not easily discolored even after long-term use.

In a preferred example of the tire of the present invention, the thermoplastic film layer has an oxygen transmission rate of 20 × 10 ⁻¹² cm ³ · cm ² · sec · cmHg or less at 20 ° C. and 65% RH. In this case, the discoloration resistance of the colored layer is greatly improved, and the thickness of the thermoplastic film layer can be reduced to, for example, 100 μm or less, thereby suppressing an increase in tire weight and rolling resistance. Can be suppressed.

  According to the present invention, the side rubber has a colored layer on the outer side in the tire width direction, and the thermoplastic film layer is disposed between the side rubber and the colored layer. It is possible to provide a tire having a high degree of freedom in color and excellent in fashionability.

1 is a cross-sectional view of a preferred embodiment of a tire according to the present invention.

  Hereinafter, the present invention will be described in detail by illustrating its embodiments. The tire according to the present invention includes a side rubber disposed in a sidewall portion, a colored layer disposed on the outer side in the tire width direction of the side rubber, and a thermoplastic film disposed between the side rubber and the colored layer. It is characterized by comprising a layer. In the tire of the present invention, a thermoplastic film layer is disposed between the side rubber and the colored layer, and the transition of additives such as an anti-aging agent from the side rubber is inhibited by the thermoplastic film layer. Contamination of the colored layer by the agent is prevented. Therefore, the colored layer of the tire of the present invention is hardly discolored even after long-term use. Further, in the tire of the present invention, the colored layer is located on the outer side in the tire width direction of the thermoplastic film layer, and the tire can be colored by the colored layer. It is highly fashionable and fashionable. In addition, since the thermoplastic film layer is lightweight, it has little influence on the tire weight and little influence on the increase in tire rolling resistance.

In the present invention, the thermoplastic film layer is not particularly limited, but the oxygen permeation amount at 20 ° C. and 65% RH is 3.0 × 10 ⁻¹² cm ³ · cm ² · sec · cmHg or less. It is preferable that If the amount of oxygen permeation at 20 ° C. and 65% RH of the thermoplastic film layer to be used is 3.0 × 10 ⁻¹² cm ³ · cm ² · sec · cmHg or less, the discoloration resistance of the colored layer is greatly increased. In addition, the desired discoloration resistance can be obtained even when the thickness of the thermoplastic film layer is reduced, for example, 100 μm or less. Therefore, when the oxygen permeation amount at 20 ° C. and 65% RH of the thermoplastic film layer to be used is 3.0 × 10 ⁻¹² cm ³ · cm ² · sec · cmHg or less, the thickness of the thermoplastic film layer is By reducing the thickness, an increase in the weight of the tire can be reliably suppressed, and an increase in rolling resistance of the tire can be reliably suppressed.

  The thickness of the thermoplastic film layer is preferably in the range of 0.1 μm to 1000 μm, more preferably in the range of 0.5 μm to 750 μm, and still more preferably in the range of 1 μm to 500 μm. By setting the thickness of the thermoplastic film layer within the above range, the bending resistance, crack resistance, durability, stretchability and the like of the thermoplastic film layer can be improved.

  The thermoplastic film layer is not particularly limited, but ethylene-vinyl alcohol copolymer resin, polyamide resin, vinylidene chloride resin, polyester resin, fluorine resin, acrylic resin, vinyl resin. A thermoplastic resin such as can be used.

  Examples of the ethylene-vinyl alcohol copolymer-based resin include an ethylene-vinyl alcohol copolymer (EVOH), a modified ethylene-vinyl alcohol copolymer (modified EVOH), and the like. The modified EVOH is a compound obtained by, for example, reacting an epoxy compound or the like with EVOH, and has a lower elastic modulus than that of ordinary EVOH.

  Examples of the polyamide resins include aliphatic polyamide homopolymers such as nylon-6, nylon-11, nylon-12, nylon-6,6, nylon-6,10, nylon-6 / 12, nylon-6 / 11. , Nylon-6 / 9, Nylon-6 / 6,6, Nylon-6 / 6,6 / 6,12 and other aliphatic polyamide copolymers, polymetaxylylene adipamide (MX-nylon), hexamethylene tele An aromatic polyamide such as a phthalamide / hexamethylene isophthalamide copolymer (nylon-6T / 6I) can be used.

  As the vinylidene chloride resin, polyvinylidene chloride and a vinylidene chloride copolymer can be suitably used. Here, the vinylidene chloride copolymer is a copolymer of vinylidene chloride and a copolymerizable monomer. Examples of the copolymerizable monomer include vinyl halides such as vinyl chloride and vinyl carboxylates such as vinyl acetate. (Meth) acrylic such as (meth) acrylic acid, crotonic acid and other unsaturated carboxylic acids, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, etc. Acid ester, (meth) acrylonitrile, etc. are mentioned.

  Examples of the polyester resin include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), and liquid crystal polyester. And aromatic polyesters such as polybutylene terephthalate-polytetramethylene glycol copolymer and polyoxyalkylene diimide diacid-polybutylene terephthalate copolymer.

  Examples of the fluororesin include polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), and tetrafluoroethylene / ethylene copolymer (ETFE).

  Examples of the acrylic resin include poly (meth) acrylate resins such as polymethyl methacrylate (PMMA) and polyethyl methacrylate, polyacrylonitrile, and the like.

  Examples of the vinyl resin include vinyl acetate (EVA), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer resin (EVOH), polyvinylidene chloride (PDVC), polyvinyl chloride (PVC), and vinyl chloride-vinylidene chloride. Examples thereof include a copolymer resin and a vinylidene chloride-methyl acrylate copolymer resin.

  For the thermoplastic film layer, a resin composition is used in which a flexible resin having a storage shear modulus (G ′) at −20 ° C. lower than that of the thermoplastic resin is dispersed in a matrix made of the thermoplastic resin. May be. Here, it is preferable that the flexible resin has a functional group that reacts with a hydroxyl group. When the flexible resin has a functional group that reacts with a hydroxyl group, the flexible resin is uniformly dispersed in the thermoplastic resin. Examples of the functional group that reacts with a hydroxyl group include a maleic anhydride residue, a hydroxyl group, a carboxyl group, and an amino group. Examples of the flexible resin having a functional group that reacts with a hydroxyl group include maleic anhydride-modified hydrogenated styrene-ethylene-butadiene-styrene block copolymer, maleic anhydride-modified ultra-low density polyethylene, and the like.

  In addition, the thermoplastic film layer may contain other resins, radical crosslinkers, heat stabilizers, ultraviolet absorbers, antioxidants, colorants, fillers, and the like, as long as the object of the present invention is not impaired. A resin composition containing various additives such as sulfur may be used. When the resin composition of the thermoplastic resin contains an additive, the amount of the additive is preferably 50% by mass or less, more preferably 30% by mass or less, with respect to the total amount of the resin composition. % Or less is particularly preferable.

  The thermoplastic film layer may include a layer made of a resin composition containing an elastomer. The elastomer is not particularly limited. For example, polystyrene-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, polydiene-based thermoplastic elastomer, polyvinyl chloride-based thermoplastic elastomer, chlorinated polyethylene-based thermoplastic elastomer, polyurethane-based thermoplastic Examples include elastomers (TPU), polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, silicone-based thermoplastic elastomers, and fluororesin-based thermoplastic elastomers. Among these, polyurethane-based thermoplastic elastomers (TPU) are preferable.

  The above-mentioned polystyrene-based thermoplastic elastomer has an aromatic vinyl polymer block (hard segment) and a rubber block (soft segment), and the aromatic vinyl polymer portion forms a physical cross-link and becomes a crosslinking point. On the other hand, the rubber block imparts rubber elasticity. The polystyrene-based thermoplastic elastomer can be divided according to the arrangement pattern of the soft segments in the molecule. For example, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), Styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), and the like. A block copolymer of crystalline polyethylene and ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and butadiene-styrene random copolymer, polybutadiene or ethylene-butadiene random Obtained by hydrogenating a block copolymer of the polymer and polystyrene, for example, also include diblock copolymer of crystalline polyethylene and polystyrene. Among these, styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene from the balance of mechanical strength, heat stability, weather resistance, chemical resistance, gas barrier properties, flexibility, workability, etc. / Butylene-styrene block copolymer (SEBS) and styrene-ethylene / propylene-styrene block copolymer (SEPS) are preferred.

  The polyolefin-based thermoplastic elastomer includes a thermoplastic elastomer having a polyolefin block such as polypropylene or polyethylene as a hard segment and a rubber block such as an ethylene-propylene-diene copolymer as a soft segment. Such thermoplastic elastomer includes a blend type and an implant type. Examples of the polyolefin-based thermoplastic elastomer include maleic anhydride-modified ethylene-butene-1 copolymer, maleic anhydride-modified ethylene-propylene copolymer, halogenated butyl rubber, modified polypropylene, and modified polyethylene. You can also.

  Examples of the polydiene thermoplastic elastomer include 1,2-polybutadiene TPE, trans 1,4-polyisoprene TPE, hydrogenated conjugated diene TPE, and epoxidized natural rubber. The 1,2-polybutadiene-based TPE is a polybutadiene containing 90% or more of 1,2-bonds in the molecule, and is crystalline syndiotactic 1,2-polybutadiene as a hard segment and amorphous as a soft segment. It consists of 1,2-polybutadiene. Trans 1,4-polyisoprene-based TPE is polyisoprene having a trans 1,4 structure of 98% or more in the molecule, and includes crystalline trans 1,4 segments as hard segments and soft segments as soft segments. It consists of amorphous trans 1,4 segments.

  The polyvinyl chloride-based thermoplastic elastomer (TPVC) generally comprises (1) high molecular weight polyvinyl chloride (PVC) / plasticized polyvinyl chloride (PVC) blend type TPVC, and (2) partially crosslinked PVC / plasticized PVC blend. Type TPVC and (3) PVC / elastomer alloy type TPVC. The above high molecular weight polyvinyl chloride (PVC) / plasticized polyvinyl chloride (PVC) blend type TPVC is a heat formed by using high molecular weight PVC for the hard segment and PVC plasticized with a plasticizer for the soft segment. It is a plastic elastomer, and a high molecular weight PVC is used for the hard segment, so that the microcrystalline portion has a function of a crosslinking point. The partially crosslinked PVC / plasticized PVC blend type TPVC is a thermoplastic elastomer using PVC in which a partially crosslinked or branched structure is introduced into a hard segment and PVC plasticized in a soft segment with a plasticizer. The PVC / elastomer alloy type TPVC is a thermoplastic elastomer using PVC as a hard segment and rubber such as partially crosslinked nitrile butadiene rubber (NBR) or TPE such as polyurethane TPE and polyester TPE as a soft segment.

  The chlorinated polyethylene-based thermoplastic elastomer is a soft resin obtained by reacting polyethylene with chlorine gas in a solvent such as an aqueous suspension or carbon tetrachloride. A chlorinated polyethylene (CPE) block is used for the segment. In the CPE block, both components of polyethylene and chlorinated polyethylene are mixed as a mixture having a multi-block or random structure.

  The polyurethane-based thermoplastic elastomer (TPU) includes (1) a polyurethane obtained by a reaction of a short-chain glycol and an isocyanate as a hard segment, and (2) a polyurethane obtained by a reaction of a long-chain glycol and an isocyanate as a soft segment. This is a linear multi-block copolymer. Here, polyurethane is a general term for compounds having a urethane bond (—NHCOO—) obtained by a polyaddition reaction (urethanization reaction) of isocyanate (—NCO) and alcohol (—OH). The TPU is composed of a polymer polyol, an organic polyisocyanate, a chain extender and the like. This polymer polyol is a substance having a plurality of hydroxyl groups, and can be obtained by polycondensation, addition polymerization (for example, ring-opening polymerization), polyaddition or the like. Examples of the polymer polyol include polyester polyol, polyether polyol, polycarbonate polyol, or a cocondensate thereof (for example, polyester-ether-polyol). These polymer polyols may be used alone or in combination of two or more. Among these, a polyester polyol or a polycarbonate polyol is preferable, and a polyester polyol is particularly preferable. Here, the polyester polyol is obtained by condensing an ester-forming derivative such as a dicarboxylic acid, an ester thereof, an anhydride thereof and the like with a low molecular polyol by a direct esterification reaction or a transesterification reaction, or a lactone. Can be produced by ring-opening polymerization.

  The polyester-based thermoplastic elastomer (TPEE) is a multi-block copolymer using polyester as a hard segment in a molecule and polyether or polyester having a low glass transition temperature (Tg) as a soft segment. TPEE can be divided into (1) polyester / polyether type TPEE, (2) polyester / polyester type TPEE, and (3) liquid crystalline TPEE depending on the molecular structure. Type TPEE dominates. The polyester / polyether type TPEE is generally a thermoplastic elastomer using an aromatic crystalline polyester as a hard segment and a polyether as a soft segment. The polyester / polyester type TPEE is a thermoplastic elastomer using an aromatic crystalline polyester as a hard segment and an aliphatic polyester as a soft segment. The liquid crystalline TPEE is a thermoplastic elastomer using a rigid liquid crystal molecule as a hard segment and an aliphatic polyester as a soft segment.

  The polyamide-based thermoplastic elastomer (TPA) is a multi-block copolymer using polyamide as a hard segment and polyether or polyester having a low Tg as a soft segment. The polyamide component constituting the hard segment is selected from nylon 6, 66, 610, 11, 12 and the like, and nylon 6 and nylon 12 are mainly used. As the constituent material of the soft segment, a long-chain polyol such as polyether diol or polyester diol is used. Representative examples of polyether polyols include diol poly (oxytetramethylene) glycol (PTMG), poly (oxypropylene) glycol, and the like. Representative examples of polyester polyols include poly (ethylene adipate) glycol, poly (butylene- 1,4 adipate) glycol and the like.

  The silicone-based thermoplastic elastomer is mainly composed of organopolysiloxane, and is divided into polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane, and some are modified with vinyl groups, alkoxy groups, etc. There are also things. Specific examples include the KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, SH series (above, manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like.

  The fluororesin-based thermoplastic elastomer is an ABA type block copolymer made of fluororesin as a hard segment and fluororubber as a soft segment. Tetrafluoroethylene-ethylene copolymer or polyvinylidene fluoride (PVDF) is used for the fluororesin constituting the hard segment, and vinylidene fluoride-hexafluoropropylene-tetrafluoro is used for the fluororubber constituting the soft segment. An ethylene terpolymer or the like is used. More specifically, it includes vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, tetrafluoroethylene-perfluoromethyl vinyl ether rubber, phosphazene fluororubber, fluoropolyether, fluoronitroso rubber, perfluorotriazine. And the like. In addition, fluororesin TPE is microphase-separated like other TPE, and the hard segment forms the crosslinking point.

  The resin composition containing the elastomer is a resin other than the elastomer material, a radical cross-linking agent, a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and a filler as necessary, as long as the object of the present invention is not impaired. Various additives may be included. When the resin composition containing an elastomer contains an additive, the amount of the additive is preferably 50% by mass or less, more preferably 30% by mass or less, and more preferably 10% by mass with respect to the total amount of the resin composition. It is particularly preferred that

  In the present invention, the paint is applied, for example, on the thermoplastic film layer of a vulcanized tire having a thermoplastic film layer by a method such as screen printing, inkjet printing, letterpress printing, or tampo printing. The coated layer can be cured to form a colored layer on the thermoplastic film layer of the tire. Further, in the present invention, the colored layer is formed on the thermoplastic film layer of the tire by in-mold molding in which a film obtained by applying a coating material on a release film or the like and curing it in advance is inserted at the time of vulcanization of the tire. It may be provided above.

  In the tire of the present invention, the paint used for forming the colored layer is not particularly limited, and examples thereof include evaporation-dried paints, oxidation polymerization paints, aroma-free paints, soybean oil paints, ultraviolet curable paints, and the like. it can. These paints preferably contain a colorant, and organic or inorganic pigments or dyes can be used as the colorant. For example, white colorants include titanium oxide, antimony white, zinc sulfide and the like, and red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, Watching Red, Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2 and the like, and examples of the blue colorant include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Partially Chlorinated Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC, etc. , Yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, hansa yellow G, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12 and the like.

  The tire according to the present invention includes the thermoplastic film layer and the colored layer described above on the outer side in the tire width direction of the side rubber disposed in the sidewall portion, but the rubber composition applied to the side rubber is particularly limited. Instead, a conventional rubber composition for a side rubber of a tire can be used. The rubber composition can be usually produced by kneading various ingredients appropriately selected as necessary with a rubber component, heating, extruding, etc., where the rubber component is a natural component. In addition to rubber (NR), synthetic polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), diene-based synthetic rubber such as polybutadiene rubber (BR), and non-diene such as ethylene-propylene-diene rubber (EPDM) Synthetic rubbers, and as compounding agents, fillers such as carbon black, anti-aging agents, vulcanizing agents such as sulfur, vulcanization accelerators, process oils, scorch preventing agents, zinc white, stearic acid, etc. The compounding agent normally used in the rubber industry of these is mentioned, As these compounding agents, a commercial item can be used conveniently.

  Below, the tire of the suitable aspect of this invention is demonstrated in detail, referring FIG. The tire shown in FIG. 1 is formed in a toroidal shape between a pair of bead portions 1, a pair of sidewall portions 2, a tread portion 3 connected to both sidewall portions 2, and a bead core 4 embedded in each bead portion 1. An extended carcass 5 and a belt 6 arranged on the outer side in the tire radial direction of the crown portion of the carcass 5 are provided. Further, the tire shown in FIG. 1 includes a pair of sidewall portions 2 and side rubbers 7, and a colored layer 8 is disposed on the outer side in the tire width direction of the side rubber 7 of one of the sidewall portions 2. A thermoplastic film layer 9 is disposed between the layer 8 and the side rubber 7. In other words, the thermoplastic film layer 9 is disposed outside the side rubber 7 in the tire width direction, and the thermoplastic film is further disposed. The colored layer 8 is disposed outside the layer 9 in the tire width direction.

  The carcass 5 in the illustrated example is composed of a single carcass ply, and has a main body portion extending in a toroidal shape between the pair of bead cores 4 and around each bead core 4 from the inside to the outside in the tire width direction. In the tire of the present invention, the number of plies and the structure of the carcass 5 are not limited to this. Further, in the illustrated tire, a belt 6 composed of two belt layers is disposed on the outer side in the tire radial direction of the crown portion of the carcass 5, and the belt layer is usually inclined with respect to the tire equatorial plane. The two belt layers are laminated such that the steel cords constituting the belt layers intersect with each other across the tire equatorial plane to constitute the belt 6. The belt 6 in the figure is composed of two belt layers, but in the tire of the present invention, the number of belt layers constituting the belt 6 may be three or more. Moreover, although the tire shown in FIG. 1 is a tire for passenger cars, the tire of this invention is not limited to this.

  The tire shown in FIG. 1 includes a thermoplastic film layer 9 on a part of the side rubber 7 on the outer side in the tire width direction, and a colored layer 8 on the thermoplastic film layer 9 (on the outer side of the tire). For example, a tire in which the thermoplastic film layer 9 is disposed on the entire outer side in the tire width direction of the side rubber 7 is also a preferred embodiment of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

<Example 1>
The raw materials shown in Table 1 are mixed by a Banbury mixer to prepare a rubber composition, and the obtained rubber composition is applied to the side rubber of the sidewall portion, and further, a thermoplastic film layer on the outer side in the tire width direction of the side rubber. And a tire for a passenger car having a size of 195 / 65R15 was produced. The thermoplastic film layer used is made of an ethylene-vinyl alcohol copolymer resin, has a thickness of 100 μm, and has an oxygen transmission rate of 2.0 × 10 ⁻¹² cm ³ · 20 ° C. and 65% RH. cm / cm ² · sec · cmHg. Next, on the surface of the thermoplastic film layer of the obtained tire, a commercially available polyester-based paint (Sunday Paint Co., Ltd., FRP / plastic paint) is applied and dried to produce a colored layer. A tire having the structure shown was obtained. The resulting tire was evaluated for rolling resistance and stain resistance by the following methods. The results are shown in Table 1.

(1) Rolling resistance Rotate the drum while bringing the test tire into contact with the drum, raise it to a certain speed, turn off the drum drive switch, rotate the drum freely, and determine the rolling resistance from the degree of deceleration. The rolling resistance of tire No. 1 is shown as an index with 100 as the rolling resistance. It shows that rolling resistance is so small that an index value is small.

(2) Contamination resistance Contamination resistance was evaluated by measuring using a spectrocolorimeter (CM-700D manufactured by Konica Minolta Co., Ltd.). About the sample obtained by each Example and the comparative example, exposure evaluation was performed outdoors and the magnitude | size of the change of the color difference 30 days after exposure and the initial color difference was evaluated. About evaluation, it displays as an index value when the color difference of the comparative example 1 is set to 100, A color difference is so small that a numerical value is large, and stain resistance becomes favorable. The evaluation results are shown in Table 1.

<Comparative Examples 1-2>
Raw materials shown in Table 1 were mixed by a Banbury mixer to prepare a rubber composition, and the obtained rubber composition was applied to the side rubber of the side wall portion to produce a tire for a passenger car having a size of 195 / 65R15. Next, on the surface of the side rubber of the obtained tire, the same acrylic paint as used in Example 1 was applied and dried to prepare a colored layer. In addition, the produced tire has the same structure as the tire of Example 1 except having no thermoplastic film layer. With respect to the obtained tire, rolling resistance and contamination were evaluated by the above methods. The results are shown in Table 1.

* 1 Polybutadiene rubber (BR): Diene rubber, BR-01 (manufactured by JSR)
* 2 Carbon Black: Carbon Black, FEF, Asahi Carbon Co., Ltd., “Asahi # 65”
* 3 Anti-aging agent: N- (1,3-dimethylbutyl) -N′-p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Co., Ltd., knock rack 6C
* 4 Vulcanization accelerator CZ-G: N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd., Noxeller CZ-G
* 5 Vulcanization accelerator DM-P: Dibenzothiazyl disulfide, manufactured by Ouchi Shinsei Chemical Co., Ltd., Noxeller DM-P

  From the comparison between Example 1 and Comparative Example 1 in Table 1, by disposing the thermoplastic film layer between the side rubber and the colored layer, the contamination resistance of the colored layer is increased without increasing the rolling resistance of the tire. It can be seen that the performance can be greatly improved. Further, from the comparison between Example 1 and Comparative Example 2, when a thermoplastic film layer is disposed between the side rubber and the colored layer, the stain resistance of the colored layer is higher than that of a tire that does not use an anti-aging agent for the side rubber. Is high.

DESCRIPTION OF SYMBOLS 1 Bead part 2 Side wall part 3 Tread part 4 Bead core 5 Carcass 6 Belt 7 Side rubber 8 Colored layer 9 Thermoplastic film layer

Claims (2)

  Comprising a side rubber disposed in the sidewall portion, a colored layer disposed on the outer side in the tire width direction of the side rubber, and a thermoplastic film layer disposed between the side rubber and the colored layer. Tire characterized by. 2. The thermoplastic film layer according to claim 1, wherein the oxygen permeation amount at 20 ° C. and 65% RH is 3.0 × 10 ⁻¹² cm ³ · cm / cm ² · sec · cmHg or less. tire.

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