JP2020116847A - Laminate for tire and pneumatic tire - Google Patents

Abstract

To provide a tire laminate having low rolling resistance and excellent operation stability when the tire is used, durability, and adhesiveness (peel strength), and a pneumatic tire using the same in an inner linear layer.SOLUTION: In a laminate for tire constituted from a film layer 9a made of a thermoplastic resin or a thermoplastic elastomer composition in which an elastomer component is dispersed in the thermoplastic resin, and an adhesive rubber layer 9B for adhering the film layer 9A to an adjacent member, in the rubber adhesive layer 9B, 0.5 pt.mass to 20 pts.mass of a condensate between a compound represented by a general equation (1) and formaldehyde, 0.25 pt.mass to 200 pts.mass of methylene doner are compounded to rubber component of 100 pts.mass containing 20 mas.% to 100 mass% of an unmodified butadiene rubber, and a ratio of compounding amount of the methylene doner to the compounding amount of the condensate is set to 0.5 to 10.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a tire laminate mainly used as an air permeation preventive layer of a pneumatic tire and a pneumatic tire using the same.

In recent years, as an air permeation preventive layer (inner liner layer) of a pneumatic tire, a thermoplastic elastomer composition in which an elastomer component is dispersed in a thermoplastic resin or a thermoplastic resin is used in place of a conventional rubber layer made of butyl rubber. Is used. At this time, since the film layer mainly composed of resin generally has low adhesiveness to rubber, the film layer is disposed on the inner surface of the tire with an adhesive rubber layer for imparting adhesiveness interposed therebetween. Therefore, a laminate including a film layer and an adhesive rubber layer (hereinafter referred to as a tire laminate) may be used as the inner liner layer.

On the other hand, in pneumatic tires, it is required to improve fuel consumption performance during traveling in order to reduce environmental load. Therefore, in order to further improve the fuel efficiency, it has been studied to suppress heat generation in a rubber composition constituting each part of a pneumatic tire (particularly, a member whose heat generation property has not been considered so far). There is. For example, in a tire using the above-mentioned tire laminate as an inner liner layer, it has been found that the exothermicity of the adhesive rubber layer has a great influence. Therefore, it is required to suppress heat generation also in the rubber composition constituting this. Has been.

As an index of exothermicity of the rubber composition, tan δ at 60° C. (hereinafter, referred to as “tan δ (60° C.)”) measured by dynamic viscoelasticity is generally used, and tan δ (60° C.) of the rubber composition is small. The lower the exothermicity, the less. Then, as a method of reducing tan δ (60° C.) of the rubber composition, for example, a compounding amount of a filler such as carbon black may be reduced or a particle size of carbon black may be increased. Alternatively, it has been proposed to blend silica (see, for example, Patent Document 1). However, these methods do not always provide sufficient rubber hardness and fatigue resistance, and when used in tires (particularly when used in the above-mentioned adhesive rubber layer), influences on steering stability and durability. Is concerned. Further, the performance as the adhesive rubber layer (adhesiveness to the film layer) may not be sufficiently obtained. Therefore, in the tire laminate (rubber composition intended for use as an adhesive rubber layer), while ensuring good steering stability, durability, and adhesiveness (peel strength) when used for a tire, Further measures are required to improve low rolling performance.

JP, 2015-059181, A

An object of the present invention is to provide a tire laminate having low rolling resistance, excellent steering stability when used in a tire, durability, and excellent adhesiveness (peel strength), and a pneumatic tire using the same. is there.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵は、水素、ヒドロキシル基または炭素原子数が１〜１２個のアルキル基である。） The tire laminate of the present invention that achieves the above-mentioned object is a thermoplastic resin or a film layer made of a thermoplastic elastomer composition in which an elastomer component is dispersed in a thermoplastic resin, and the film layer is adhered to an adjacent member. And a bonding rubber layer for the tire, wherein the bonding rubber layer has the following general formula (100 parts by mass with respect to 100 parts by mass of a rubber component containing 20% by mass to 100% by mass of terminal modified butadiene rubber). The compound represented by 1) and a formaldehyde condensate are mixed in an amount of 0.5 to 20 parts by mass and a methylene donor in an amount of 0.25 to 200 parts by mass. It is characterized in that the blending ratio is 0.5 to 10.

(In the formula, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are hydrogen, a hydroxyl group, or an alkyl group having 1 to 12 carbon atoms.)

In the tire laminate of the present invention, since the adhesive rubber layer is composed of the above-mentioned specific rubber composition, steering stability when used in a tire while reducing rolling resistance, durability, adhesiveness ( The peel strength) can be improved. In particular, the rubber composition constituting the adhesive rubber layer uses a specific condensate, a methylene donor, and a terminal-modified butadiene rubber in combination, so that it is possible to enhance the rubber physical properties without deteriorating the heat generation property, The above-mentioned performance can be improved in a well-balanced manner.

In the present invention, the thermoplastic resin is polyvinyl alcohol, ethylene-vinyl alcohol copolymer, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon MXD6, and nylon 6T. It is preferably at least one selected from the group consisting of This makes it possible to improve the physical properties of the film layer, which is particularly advantageous for improving the adhesiveness (peel strength).

In the present invention, the elastomer component is a brominated isobutylene-p-methylstyrene copolymer, a maleic anhydride modified ethylene-α-olefin copolymer, an ethylene-glycidyl methacrylate copolymer, and a styrene-isobutylene-styrene block copolymer. It is preferably at least one selected from the group consisting of a polymer, an acid anhydride-modified styrene-isobutylene-styrene block copolymer, and a maleic anhydride-modified ethylene-ethyl acrylate copolymer. This makes it possible to improve the physical properties of the film layer, which is particularly advantageous for improving the adhesiveness (peel strength).

In the present invention, the methylene donor is preferably at least one selected from the group consisting of modified etherified methylolmelamine, paraformaldehyde, hexamethylenetetramine, pentamethylenetetramine, and hexamethoxymethylmelamine. This makes it possible to improve the physical properties of the adhesive rubber layer, which is particularly advantageous for improving the adhesiveness (peel strength).

In the present invention, the molecular weight distribution (Mw/Mn) determined from the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the terminal-modified butadiene rubber compounded in the rubber composition constituting the adhesive rubber layer is 2.0 or less. Is preferred. By narrowing the molecular weight distribution in this manner, the rubber physical properties become better, which is advantageous for improving the durability while reducing the rolling resistance. The "weight average molecular weight Mw" and the "number average molecular weight Mn" are measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

In the present invention, the terminal functional group of the terminal-modified butadiene rubber compounded in the rubber composition constituting the adhesive rubber layer is selected from the group consisting of a hydroxyl group, an amino group, an amide group, an alkoxyl group, an epoxy group and a siloxane bonding group. At least one kind is preferable. Accordingly, when the adhesive rubber layer contains carbon black, the affinity with carbon black is increased and the dispersibility of carbon black is further improved, so that rubber hardness and rubber hardness and The durability can be increased, which is advantageous for achieving a good balance of these performances.

The tire laminate of the present invention is preferably used as an inner liner material for a pneumatic tire. Further, the pneumatic tire including the inner liner layer formed of the tire laminate of the present invention has excellent physical properties of the rubber composition forming the above-mentioned adhesive rubber layer, thereby reducing rolling resistance and stabilizing steering. Property, durability, and adhesiveness (peel strength) can be improved.

It is a meridian half cross section of the pneumatic tire which consists of embodiment of this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a pneumatic tire of the present invention includes a tread portion 1, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a sidewall portion 2 which is arranged inside a tire radial direction. And a pair of bead portions 3. In FIG. 1, reference symbol CL indicates the tire equator. Although not shown because FIG. 1 is a meridional cross-sectional view, the tread portion 1, the sidewall portion 2, and the bead portion 3 each extend in the tire circumferential direction to form an annular shape. The toroidal basic structure of is constructed. Hereinafter, although the description with reference to FIG. 1 is basically based on the meridian cross-sectional shape shown in the drawing, each tire constituent member extends in the tire circumferential direction to form an annular shape.

A carcass layer 4 is mounted between the pair of left and right bead portions 3. The carcass layer 4 is folded back from the inside of the vehicle to the outside around a bead core 5 arranged in each bead portion 3. A bead filler 6 is arranged on the outer periphery of the bead core 5, and the bead filler 6 is wrapped by the main body portion and the folded portion of the carcass layer 4. On the other hand, a plurality of belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. Further, a belt reinforcing layer 8 is provided on the outer peripheral side of the belt layer 7.

In the above pneumatic tire, an inner liner layer 9 is provided inside the carcass layer 4 and at a portion facing the tire cavity. The inner liner layer 9 includes a film layer 9A made of a thermoplastic resin or a thermoplastic elastomer composition in which an elastomer component is dispersed in the thermoplastic resin, and the film layer 9A except for the inner liner layer 9 is located closest to the tire cavity side. It is composed of a tire laminated body including an adhesive rubber layer 9B for adhering to a positioned tire constituent member (hereinafter, may be referred to as "adjacent member").

The concrete structure of the pneumatic tire of the present invention is not limited to the above-mentioned basic structure as long as the tire laminate described below is used as the inner liner layer 9.

In the rubber composition for tires (hereinafter, sometimes referred to as "rubber composition part for tire of the present invention") constituting the adhesive rubber layer 9B of the tire laminate, the rubber component is a diene rubber and the terminal modified butadiene rubber. Be sure to include.

The terminal-modified butadiene rubber is a butadiene rubber modified with an organic compound having a functional group at one end or both ends of the molecular chain. By blending such a terminal-modified butadiene rubber, the affinity with the carbon black described later is increased and the dispersibility is improved, so that the action and effect of the carbon black is further improved while keeping the exothermicity low. The rubber hardness can be increased. Examples of the functional group that modifies the terminal of the molecular chain include an alkoxysilyl group, a hydroxyl group (hydroxyl group), an aldehyde group, a carboxyl group, an amino group, an amide group, an imino group, an alkoxyl group, an epoxy group, an amide group, a thiol group, Examples thereof include ether groups and siloxane bonding groups. Among them, at least one selected from a hydroxyl group (hydroxyl group), an amino group, an amide group, an alkoxyl group, an epoxy group, and a siloxane bonding group is preferable. Here, the siloxane bonding group is a functional group having a -O-Si-O- structure.

When the total amount of the rubber component (diene rubber) is 100% by mass, the compounding amount of the terminal-modified butadiene rubber is 20% by mass to 100% by mass, preferably 20% by mass to 70% by mass. If the compounding amount of the terminal-modified butadiene rubber is less than 20% by mass, fuel economy is deteriorated.

The molecular weight distribution (Mw/Mn) determined from the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the terminal-modified butadiene rubber is preferably 2.0 or less, more preferably 1.1 to 1.6. In this way, by using a terminal-modified butadiene rubber having a narrow molecular weight distribution, the rubber physical properties become better, and while reducing rolling resistance, steering stability when tired, durability, and peel strength are improved. Can be effectively improved. When the molecular weight distribution (Mw/Mn) of the terminal-modified butadiene rubber exceeds 2.0, the hysteresis loss becomes large, the heat generation property of the rubber becomes large, and the compression set resistance decreases.

The tire rubber composition of the present invention may contain a diene rubber other than natural rubber and terminal-modified butadiene rubber. Other diene rubbers include, for example, butadiene rubber without terminal modification, styrene butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber and the like. These diene rubbers can be used alone or as an arbitrary blend.

Among these other diene rubbers, it is preferable to use natural rubber, and by blending natural rubber, sufficient rubber strength as a rubber composition for tires can be obtained. As the natural rubber, a rubber usually used in a rubber composition for tires can be used. When the total amount of the rubber component (diene rubber) is 100% by mass, the compounding amount of the natural rubber is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 80% by mass. Further, in addition to the natural rubber, it is also preferable to use other butadiene rubber which is not end-modified. The combined use of the terminal-modified butadiene rubber, the natural rubber, and the other butadiene rubber can improve the sheet property formation and the interface formability at the time of adhesion. As the other butadiene rubber which is not end-modified, a rubber usually used in a rubber composition for tires can be used. When the total amount of the rubber component (diene rubber) is 100% by mass, the compounding amount of the other butadiene rubber which is not end-modified is preferably 30% by mass to 60% by mass, more preferably 30% by mass to 50% by mass. is there.

The tire rubber composition of the present invention preferably contains carbon black as a filler. By blending carbon black, the strength of the rubber composition can be increased. In particular, carbon black used in the present invention, the nitrogen adsorption specific surface area N ₂ SA is preferably 20m ² / g~150m ² / g, more preferably 20m ² / g~120m ² / g. By thus blending the carbon black having a specific particle size in combination with the above-mentioned terminal-modified butadiene rubber, it is possible to effectively increase the rubber hardness while keeping the heat generation property low. When the nitrogen adsorption specific surface area N ₂ SA of carbon black is preferably less than 20 m ² /g, the durability of the tire is deteriorated. When the nitrogen adsorption specific surface area N ₂ SA of carbon black is preferably more than 150 m ² /g, the exothermic property deteriorates.

The blending amount of carbon black is preferably 20 parts by mass to 80 parts by mass, and more preferably 30 parts by mass to 70 parts by mass with respect to 100 parts by mass of the above-mentioned rubber component. When the blending amount of carbon black is less than 20 parts by mass, the hardness is lowered and the durability of the tire is lowered. If the blending amount of carbon black exceeds 80 parts by mass, the exothermic property deteriorates.

The rubber composition of the present invention may contain an inorganic filler other than carbon black. Examples of other inorganic fillers include silica, clay, talc, calcium carbonate, mica, aluminum hydroxide and the like.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵は、水素、ヒドロキシル基または炭素原子数が１〜１２個のアルキル基である。） The rubber composition of the present invention always contains a condensate of a compound represented by the following general formula (1) and formaldehyde. By using such a material, the adhesion between the film layer 9A and the adhesive rubber layer 9B in the tire laminate becomes good.

(In the formula, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are hydrogen, a hydroxyl group, or an alkyl group having 1 to 12 carbon atoms.)

The amount of the condensate compounded is 0.5 to 20 parts by mass, preferably 2 to 8 parts by mass, based on 100 parts by mass of the rubber component. Thereby, the adhesion between the film layer 9A and the adhesive rubber layer 9B in the tire laminate can be improved. If the amount of this condensate is less than 0.5 parts by mass, the adhesiveness to the film layer 9A will be insufficient. If the amount of the condensate compounded exceeds 20 parts by mass, the hardness of the rubber composition becomes excessive, and the tire layer may not be able to follow the deformation of the tire and peeling off from the film layer 9 may occur.

Examples of this condensate include a resol type condensate and a novolac type condensate. As the resol type condensate, for example, a resol type phenolic resin (alkylphenol-formaldehyde condensate) can be used. As the novolac type condensate, for example, a novolac type phenol resin (modified resorcin-formaldehyde condensate) can be used. The use of a resol type condensate has an advantage that it is unnecessary to add a methylene donor because it has self-reactivity. Further, when a novolac type condensate is used, there is an advantage that the reaction can be easily controlled and the adhesiveness can be controlled by the addition amount of the methylene donor. From the viewpoint of reaction control, it is particularly preferable to use a novolac type condensate.

The rubber composition of the present invention always contains a methylene donor. Examples of the methylene donor include modified etherified methylolmelamine, hexamethylenetetramine, pentamethylenetetramine, hexamethylenediamine, methylolmelamine, etherified methylolmelamine, esterified methylolmelamine, hexamethoxymethylolmelamine, hexamethylolmelamine, hexakis(ethoxy). Methyl)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',N"-trimethylolmelamine, paraformaldehyde, etc. can be used. From the viewpoint of, modified etherified methylol melamine, paraformaldehyde, hexamethylene tetramine, pentamethylene tetramine, and hexamethoxymethyl melamine are preferable.The amount of the methylene donor is 0.25 parts by mass with respect to 100 parts by mass of the rubber component. To 200 parts by mass, preferably 3 parts by mass to 24 parts by mass, in particular, the ratio of the compounding amount of the methylene donor to the compounding amount of the above-mentioned condensate is 0.5 to 10, preferably 1.5 to 3.0. If the content of the methylene donor is less than 0.25 parts by mass, the adhesiveness to the film layer 9A is insufficient.If the content of the methylene donor exceeds 200 parts by mass, the hardness of the rubber composition is increased. Is too large to follow the deformation of the tire and peeling off from the film layer 9. When the ratio of the methylene donor content to the condensate content is less than 0.5, the film layer 9A is not formed. If the ratio of the content of the methylene donor to the content of the condensate exceeds 10, the hardness of the rubber composition becomes excessive and the tire cannot follow the deformation of the film layer. There is a risk that peeling from 9 will occur.

Compounding agents other than the above may be added to the rubber composition for a tire of the present invention. Examples of other compounding agents include various compounding agents generally used for pneumatic tires, such as vulcanizing or crosslinking agents, vulcanization accelerators, antioxidants, liquid polymers, thermosetting resins, and thermoplastic resins. can do. The compounding amount of these compounding agents can be a conventional general compounding amount as long as the object of the present invention is not impaired. As the kneading machine, a usual kneading machine for rubber, for example, Banbury mixer, kneader, roll or the like can be used.

The rubber composition for a tire of the present invention can improve the steering stability, durability, and adhesiveness (peel strength) when used in a tire while reducing rolling resistance due to the above-mentioned composition and physical properties. In particular, since a specific condensate, methylene donor, and terminal modified butadiene rubber are used in combination, it is possible to increase the adhesiveness and rubber hardness without deteriorating heat generation and improve the above-mentioned performance in a well-balanced manner. can do. Therefore, the rubber composition for a tire of the present invention can be suitably used for the adhesive rubber layer 9B of the tire laminate intended to be used for the inner liner layer 9. The tire laminate using the tire rubber composition of the present invention as the adhesive rubber layer 9B can reliably adhere the film layer 9A to an adjacent member due to its excellent adhesiveness, and has low rolling resistance. Therefore, the heat generation property of the entire tire can be reduced. Further, due to its excellent physical properties, steering stability and durability can be exhibited well.

When the film layer 9A of the tire laminate of the present invention is composed of a thermoplastic resin, examples of the thermoplastic resin include polyamide resins [for example, nylon 6 (N6), nylon 66 (N66), nylon 46 ( N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6/66 copolymer (N6/66), nylon 6/66/610 copolymer ( N6/66/610), nylon MXD6 (MXD6), nylon 6T, nylon 9T, nylon 6/6T copolymer, nylon 66/PP copolymer, nylon 66/PPS copolymer] and N-alkoxyalkyl thereof. Compounds such as methoxymethylated products of nylon 6, methoxymethylated products of nylon 6/610 copolymer, methoxymethylated products of nylon 612, polyester resins [eg polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene Aromatic polyesters such as isophthalate (PEI), PET/PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, polyoxyalkylene diimidodiacid/polybutylene terephthalate copolymer], Polynitrile resin [eg, polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile/styrene copolymer (AS), (meth)acrylonitrile/styrene copolymer, (meth)acrylonitrile/styrene/butadiene copolymer], Polymethacrylate resin [eg, polymethylmethacrylate (PMMA), polyethylmethacrylate], polyvinyl resin [eg, polyvinyl acetate, polyvinyl alcohol (PVA), vinyl alcohol/ethylene copolymer (EVOH), polychlorination Vinylidene (PVDC), polyvinyl chloride (PVC), vinyl chloride/vinylidene chloride copolymer, vinylidene chloride/methyl acrylate copolymer, vinylidene chloride/acrylonitrile copolymer (ETFE)], cellulose resin [eg cellulose acetate , Cellulose acetate butyrate], fluororesins [eg, polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), tetrafluoroethylene/ethylene copolymer], imide resins [eg, Aromatic polyimide (PI)] or the like can be used. Among them, at least 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 MXD6, and nylon 6T. It is preferable to use one kind.

When the film layer 9A of the tire laminate of the present invention is composed of a thermoplastic elastomer composition in which an elastomer component is dispersed in a thermoplastic resin, the above-mentioned thermoplastic resin can be used. Examples of the elastomer component include diene rubber and hydrogenated products thereof [eg, natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR, high cis BR). And low cis BR), nitrile rubber (NBR), hydrogenated NBR, hydrogenated SBR], olefin rubber [eg, ethylene propylene rubber (EPDM, EPM), maleic acid modified ethylene propylene rubber (M-EPM), butyl rubber ( IIR), isobutylene and aromatic vinyl or diene-based monomer copolymer, acrylic rubber (ACM), ionomer], halogen-containing rubber [eg Br-IIR, CI-IIR, brominated isobutylene-p-methylstyrene copolymer] (BIMS), chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfonated polyethylene rubber (CSM), chlorinated polyethylene rubber (CM), maleic acid modified chlorinated polyethylene rubber (M-CM)], silicone rubber [eg, , Methyl vinyl silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber], sulfur-containing rubber [for example, polysulfide rubber], fluororubber [for example, vinylidene fluoride rubber, fluorovinyl ether rubber, tetrafluoroethylene-propylene rubber] , Fluorine-containing silicone rubber, fluorine-containing phosphazene rubber], thermoplastic elastomer [eg, styrene elastomer, olefin elastomer, ester elastomer, urethane elastomer, polyamide elastomer] and the like can be used. Among them, brominated isobutylene-p-methylstyrene copolymer, maleic anhydride-modified ethylene-α-olefin copolymer, ethylene-glycidyl methacrylate copolymer, and styrene-isobutylene-styrene block copolymer, acid anhydride It is preferable to use at least one selected from the group consisting of a modified styrene-isobutylene-styrene block copolymer and a maleic anhydride-modified ethylene-ethyl acrylate copolymer.

Further, when the above-mentioned specific thermoplastic resin and the specific elastomer component are combined and blended, if the compatibility is different, both can be compatibilized by using an appropriate compatibilizing agent as the third component. By mixing the compatibilizer in the blend system, the interfacial tension between the thermoplastic resin and the elastomer component is lowered, and as a result, the particle diameter of the elastomer component forming the dispersed phase becomes fine, so that The characteristics will be expressed more effectively. As such a compatibilizing agent, generally, a copolymer having a structure of one or both of a thermoplastic resin and an elastomer component, or an epoxy group, a carbonyl group, a halogen group capable of reacting with the thermoplastic resin or the elastomer component, It may have a structure of a copolymer having an amino group, an oxazoline group, a hydroxyl group and the like. These may be selected depending on the types of the thermoplastic resin and the elastomer component to be blended, and the commonly used ones are styrene/ethylene/butylene block copolymer (SEBS) and its maleic acid modified product, EPDM, EPM. , EPDM/styrene or EPDM/acrylonitrile graft copolymers and maleic acid modified products thereof, styrene/maleic acid copolymers, and reactive phenoxine. The compounding amount of the compatibilizing agent is not particularly limited, but preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymer component (the total of the thermoplastic resin and the elastomer component).

In the thermoplastic elastomer composition in which the elastomer component is dispersed in the thermoplastic resin, the composition ratio of the specific thermoplastic resin and the elastomer component is not particularly limited, and the elastomer component is not contained in the matrix of the thermoplastic resin. It may be appropriately determined so as to have a dispersed structure as a continuous phase. The weight ratio of the thermoplastic resin to the elastomer component is preferably 90/10 to 30/70.

The thermoplastic elastomer composition in which the elastomer component is dispersed in the thermoplastic resin may be mixed with another polymer such as a compatibilizer within a range that does not impair the required properties as an inner liner. The purpose of mixing other polymers is to improve the compatibility between the thermoplastic resin and the elastomer component, to improve the moldability of the material, to improve the heat resistance, to reduce the cost, etc. Examples of the material used include polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS, SBS, polycarbonate (PC), and the like. The elastomer component can also be dynamically vulcanized during mixing with the thermoplastic resin. The vulcanizing agent, vulcanizing aid, vulcanizing condition (temperature, time) and the like for dynamically vulcanizing may be appropriately determined according to the composition of the elastomer component to be added, and are not particularly limited.

The tire laminate of the present invention comprising the above-mentioned film layer 9A and the adhesive rubber layer 9B has excellent physical properties of each layer, and while reducing rolling resistance, handling stability, durability and adhesiveness when formed into a tire. (Peeling strength) can be improved. Therefore, the pneumatic tire including the inner liner layer 9 composed of the tire laminate can improve the fuel economy performance, steering stability, durability, and adhesiveness (peel strength) in a well-balanced manner.

Hereinafter, the present invention will be further described with reference to examples, but the scope of the present invention is not limited to these examples.

From a rubber sheet composed of 19 kinds of rubber compositions (standard example 1, comparative examples 1 to 7, examples 1 to 11) having the formulations shown in Tables 1 and 2, and a thermoplastic elastomer composition having the composition shown in Table 3. Was laminated with the film layer to produce a tire laminate. Further, a pneumatic tire (tire size 195/65R15) using the manufactured tire laminate as an inner liner layer was prepared.

With respect to the obtained tire laminate and the pneumatic tire, the peel strength, low fuel consumption performance, steering stability and durability were evaluated by the methods described below.

Peel strength The peel force was measured when the film layer and the adhesive rubber layer of the obtained tire laminate were pulled in opposite directions (180°). The obtained results are shown in the "peel strength" column of Tables 1 and 2 as an index with the value of Standard Example 1 as 100. The larger the index value, the larger the peeling force, which means that the adhesiveness between the film layer and the adhesive rubber layer is excellent.

Low fuel consumption performance Each pneumatic tire was assembled to a standard rim, and an indoor drum tester (drum diameter: 1707.6 mm) was used, in accordance with ISO28580, air pressure of 210 kPa, load of 4.82 kN, speed of 80 km/h. The rolling resistance was measured with. The evaluation result is shown by an index with the value of Standard Example 1 being 100, using the reciprocal of the measured value. The larger the index value, the lower the rolling resistance and the better the fuel efficiency.

Steering stability Each pneumatic tire was mounted on a standard rim, mounted on a test vehicle, the air pressure was set to 230 kPa, and a sensory test was conducted by a test driver on steering stability. The evaluation results are shown by an index with the standard example 1 being 100. The larger this index value, the better the steering stability.

Durability Assemble each pneumatic tire to the standard rim and use an indoor drum tester (drum diameter: 1707 mm) in accordance with JIS D-4230, after every 5 hours after the JATMA 2018 version specified load durability test. The load was increased by 20% and the running distance until the tire was broken was measured. The evaluation results are shown by an index with the measured value of Standard Example 1 being 100. The larger the index value, the better the durability.

The types of raw materials used in Tables 1 and 2 are shown below.
・NR: Natural rubber, SIR-20
BR: butadiene rubber, BR01 manufactured by JSR
Modified BR1: terminal modified butadiene rubber, BR54 manufactured by JSR (glass transition temperature Tg: −107° C., functional group: silanol group, molecular weight distribution Mw/Mn=2.5)
-Modified BR2: terminal-modified butadiene rubber synthesized by the following method (glass transition temperature Tg: -93°C, functional group: polyorganosiloxane group, refer to the following for molecular weight distribution)
-Modified BR3: Terminal-modified butadiene rubber, Nipol BR1250H manufactured by Nippon Zeon Co., Ltd. (glass transition temperature Tg: -96°C, functional group: N-methylpyrrolidone group, molecular weight distribution Mw/Mn = 1.1).
・CB: Carbon black, Tokai Carbon Co., Ltd., Seast V (nitrogen adsorption specific surface area N ₂ SA: 27 m ² /g)
-Stearic acid: Nisshin Rika-Aroma oil: Showa Shell Sekiyu's "Desolex 3"
・Zinc oxide: 3 types of zinc oxide manufactured by Shodo Kagaku Kogyo Co., Ltd. ・Condensate: modified resorcin/formaldehyde condensate, Sumikanol 620 manufactured by Sumitomo Chemical Co., Ltd.
・Methylene donor: Sumikanol 507AP manufactured by Taoka Chemical Co., Ltd.
・Sulfur: 5% oil-extended sulfur and vulcanization accelerator: Nouchira DM manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

Method for synthesizing modified BR2 After charging cyclohexane 5670 g, 1,3-butadiene 700 g and tetramethylethylenediamine 0.17 mmol in a nitrogen atmosphere in an autoclave equipped with a stirrer, the polymerization contained in cyclohexane and 1,3-butadiene is inhibited. The amount of n-butyllithium necessary for neutralizing the impurities was added, and further, 8.33 mmol of n-butyllithium for the polymerization reaction was added, and the polymerization was started at 50°C. After 20 minutes from the start of the polymerization, 300 g of 1,3-butadiene was continuously added over 30 minutes. The maximum temperature during the polymerization reaction was 80°C. After the continuous addition was completed, the polymerization reaction was continued for another 15 minutes, and after confirming that the polymerization conversion rate was in the range of 95% to 100%, a small amount of the polymerization solution was sampled. A small amount of the sampled polymerization solution was added with excess methanol to stop the reaction, and then air-dried to obtain a polymer, which was used as a sample for gel permeation chromatography (GPC) analysis. Using the sample, the peak top molecular weight and the molecular weight distribution of the polymer (corresponding to a conjugated diene-based polymer chain having an active end) were measured and found to be "230,000" and "1.04", respectively.

Immediately after sampling the aforementioned small amount of the polymerization solution, 40% by weight of 0.288 mmol of 1,6-bis(trichlorosilyl)hexane (corresponding to 0.0345 times mol of n-butyllithium used for the polymerization) was added to the polymerization solution. It was added in the state of a cyclohexane solution and reacted for 30 minutes. Further, after that, 0.0382 mmol of polyorganosiloxane A (corresponding to 0.00459 times mol of n-butyllithium used for polymerization) was added in the state of a 20 wt% xylene solution, and the reaction was carried out for 30 minutes. Then, as a polymerization terminator, methanol was added in an amount corresponding to twice the mol of n-butyllithium used. As a result, a solution containing the modified butadiene rubber was obtained. To this solution, after adding 0.2 parts of 2,4-bis(n-octylthiomethyl)-6-methylphenol as an antioxidant per 100 parts of rubber component, the solvent was removed by steam stripping, It was vacuum dried at 24° C. for 24 hours to obtain a solid modified butadiene rubber (modified BR2). With respect to this modified butadiene rubber (modified BR2), the weight average molecular weight, molecular weight distribution, coupling rate, vinyl bond content, and Mooney viscosity were measured to be "510,000", "1.46", and "28", respectively. %", "11 mass%" and "46".

The types of raw materials used in Table 3 are shown below.
Br-IPMS: brominated isobutylene-p-methylstyrene copolymer, Exxpro 3035 manufactured by ExxonMobil Chemical Company
Modified EEA: Maleic anhydride modified ethylene-ethyl acrylate copolymer, HPR-AR201 manufactured by Mitsui DuPont Polychemicals
・N6/66: Nylon 6/66 copolymer, UBE Ube Nylon 5033B manufactured by Ube Industries, Ltd.
・Zinc oxide: manufactured by Shodo Kagaku Kogyo Co., Ltd., Zinc Hua No. 3 ・Stearic acid: manufactured by Chiba Fatty Acid Company, industrial stearic acid, zinc stearate: manufactured by NOF CORPORATION, zinc stearate

As is clear from Tables 1 and 2, the tire laminates and pneumatic tires of Examples 1 to 11 maintain a good balance of peel strength, fuel efficiency performance, driving stability, and durability with respect to Standard Example 1. Or improved.

On the other hand, since the tire laminate and the pneumatic tire of Comparative Example 1 did not contain the terminal-modified butadiene rubber, the peel strength, the steering stability, and the durability deteriorated. In the tire laminates and the pneumatic tires of Comparative Examples 2 to 4, since the compounding amount of the terminal-modified butadiene rubber was small and the compounding amount of carbon black was small, the peel strength, the steering stability, and the durability were deteriorated. The tire laminates and the pneumatic tires of Comparative Examples 5 to 7 did not have the effect of improving the peel strength, the fuel consumption performance, the driving stability, and the durability because the amount of the terminal-modified butadiene rubber was small. ..

1 Tread Part 2 Sidewall Part 3 Bead Part 4 Carcass Layer 5 Bead Core 6 Bead Filler 7 Belt Layer 8 Belt Reinforcing Layer 9 Inner Liner Layer 9A Film Layer 9B Adhesive Rubber Layer CL Tire Equator

Claims (8)

A tire laminate comprising a film layer made of a thermoplastic resin or a thermoplastic elastomer composition in which an elastomer component is dispersed in the thermoplastic resin, and an adhesive rubber layer for adhering the film layer to an adjacent member. And
In the adhesive rubber layer, 0.5 parts by mass of a condensate of a compound represented by the following general formula (1) and formaldehyde is used with respect to 100 parts by mass of a rubber component containing 20% by mass to 100% by mass of terminal modified butadiene rubber. Part to 20 parts by mass, 0.25 to 200 parts by mass of a methylene donor, and a ratio of the content of the methylene donor to the content of the condensate is 0.5 to 10. Laminate.

(In the formula, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are hydrogen, a hydroxyl group, or an alkyl group having 1 to 12 carbon atoms.) 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 MXD6, and nylon 6T. It is at least 1 sort(s) selected, The laminated body for tires of Claim 1 characterized by the above-mentioned. The elastomer component is a brominated isobutylene-p-methylstyrene copolymer, a maleic anhydride-modified ethylene-α-olefin copolymer, an ethylene-glycidyl methacrylate copolymer, and a styrene-isobutylene-styrene block copolymer, an acid. The tire according to claim 1 or 2, wherein the tire is at least one selected from the group consisting of an anhydride-modified styrene-isobutylene-styrene block copolymer and a maleic anhydride-modified ethylene-ethyl acrylate copolymer. Laminate. 4. The methylene donor is at least one selected from the group consisting of modified etherified methylol melamine, paraformaldehyde, hexamethylene tetramine, pentamethylene tetramine, and hexamethoxymethyl melamine. A laminated body for a tire according to claim 1. The molecular weight distribution (Mw/Mn) obtained from the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the terminal-modified butadiene rubber compounded in the rubber composition constituting the adhesive rubber layer is 2.0 or less. The laminated body for tires according to any one of claims 1 to 4 characterized by things. The terminal functional group of the terminal-modified butadiene rubber compounded in the rubber composition constituting the adhesive rubber layer is at least one selected from the group consisting of a hydroxyl group, an amino group, an amide group, an alkoxyl group, an epoxy group, and a siloxane bonding group. It is a seed, The laminated body for tires in any one of Claims 1-5. An inner liner material for a pneumatic tire comprising the tire laminate according to any one of claims 1 to 6. A pneumatic tire comprising an inner liner layer composed of the tire laminate according to claim 1.

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