Repair sheet and tire repair method

Abstract

The purpose of the present disclosure is to provide a repair sheet that allows for more labor-saving processing of tires and a method for repairing tires. A repair sheet for attachment to a tire portion is provided, the repair sheet comprising a retaining layer capable of retaining an additive for supplying to the tire portion, wherein the retaining layer has a breaking strength of 0.5 MPa or more and an elongation at break of 5% or more.

Description

Technical Field

[0001] The present disclosure relates to a repair sheet and a tire repair method. Background Art

[0002] Conventionally, for a tire whose tire rubber has reached the end of its service life, for example, a tire whose tread has reached the end of its service life, a processing method of removing the old tread and then replacing the old tread with new tread rubber is known (Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: JP 2018-114781 A Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the conventional processing method, operations such as removing the tread portion and attaching a new tread portion are required, and thus such processing requires time and effort.

[0008] The object of the present disclosure is to provide a repairing sheet and a tire repairing method.

[0009] Means of solving the problem

[0010] The present disclosure relates to a repair sheet for attachment to a tire portion, the repair sheet comprising:

[0011] a retaining layer, which can retain an additive for supplying to a tire region,

[0012] The holding layer has a breaking strength of 0.5 MPa or more and a breaking elongation of 5% or more.

[0013] Effects of the Invention

[0014] The present disclosure can provide a tire repair sheet and a tire repair method that can process a tire with less effort. DETAILED DESCRIPTION

[0015] The repair sheet involved in the present invention is a repair sheet for attaching to a tire part, and the repair sheet includes a retaining layer, which can retain additives supplied to the tire part, wherein the retaining layer has a breaking strength of more than 0.5 MPa and a breaking elongation of more than 5%.

[0016] According to this structure, since the repair sheet has a breaking strength of more than a predetermined value, it is less likely to break during use, and further, since the repair sheet has a breaking elongation of more than a predetermined value, it can easily follow the tire part during use. Therefore, it is easy to handle. Accordingly, the tire can be processed more laboriously. In addition, the supply amount of the additive can be adjusted by the repair time during which the repair sheet retaining the additive is in contact with the tire and by the amount of the additive retained in the repair sheet. In addition, the physical properties of the retaining layer having a breaking strength of more than 0.5 MPa and an elongation at break of more than 5% are values ​​in a state where no additive is retained in the retaining layer. In addition, "repair" in the present disclosure refers not only to tire processing for improving or maintaining the performance of used tires, but also means including tire processing for improving or changing the performance of new tires.

[0017] Preferably, the holding layer is composed of a material containing at least one selected from a thermoplastic elastomer, a resin, and a cross-linked rubber. This is because it becomes easy to obtain a predetermined holding layer according to the present disclosure.

[0018] Preferably, the thickness of the retaining layer is 100 mm or less, because if the retaining layer becomes too thick, it becomes difficult to handle.

[0019] Preferably, the repairing sheet further includes a support layer for supporting the holding layer. This is because the repairing sheet becomes easy to handle by further including the support layer.

[0020] The repair sheet of the present disclosure is used for processing a tire in a state where the additive is retained in the retaining layer. Preferably, the additive contains at least one selected from a plasticizer, an antioxidant, and a vulcanization accelerator.

[0021] Another embodiment of the present disclosure is a tire repair method including the steps of attaching the repair sheet to a tire portion and supplying the additive to the tire portion.

[0022] When the repair sheet is attached to the tread portion of the tire, preferably, the longitudinal length of the retaining layer does not exceed the tire width plus 10 mm, the lateral length does not exceed the tire circumference plus 10 mm, and the thickness is 110 mm or less.

[0023] [definition]

[0024] (Tire part)

[0025] Tire site is a term used to specify the position of tire components constituting the tire surface (including the outer surface and the inner surface) on the surface, for example, the tread portion, the sidewall portion, the lap portion, the wing portion, the inner liner portion, etc., but is not limited to these (as long as the position of the tire component on the surface can be specified).

[0026] [Measurement method]

[0027] (Additive content in tire tread)

[0028] According to JIS K 6229, by immersing a sample cut out from the tread surface of each tire in acetone for 24 hours, extracting the soluble components, and measuring the mass of each sample before and after the extraction, the content of the additive was determined as the amount of the extract using the following formula:

[0029] Amount of extract (%) = {(mass of sample before extraction - mass of sample after extraction) / (mass of sample before extraction)} × 100

[0030] (Hardness of tire tread)

[0031] According to JIS K 6253, the hardness is measured by pressing a type A durometer on a sample at 23°C.

[0032] (Breaking strength and breaking elongation of the holding layer)

[0033] According to JIS K 6251 "Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties", a tensile test is performed on a dumbbell-shaped test piece No. 7 with a thickness of 1 mm at a tensile speed of 3.3 mm / sec at 23°C to measure the breaking strength TB (in MPa) and the breaking elongation EB (in %).

[0034] (Ozone resistance of tire tread)

[0035] According to JIS K 6259 "Vulcanized rubber or thermoplastic rubber - Determination of ozone resistance", ozone resistance is evaluated by preparing a test piece of a predetermined size from the surface of the tread portion and subjecting the test piece to a dynamic ozone degradation test. Specifically, under the conditions of an ozone concentration of 50±5pphm, a test temperature of 40°C, and a tensile strain of 10±2%, the test piece is subjected to a reciprocating motion test with a frequency of 0.5±0.025Hz for 48 hours, and after the test, the state of cracks generated on the test piece (the presence or absence of cracks, the number of cracks, the length of cracks, etc.) is observed. The method described in JIS K 6259 (Method A: Crack state observation method) is used as an evaluation method. Specifically, a numerical value indicating the degree of crack generation defined by multiplying the number of cracks of 0.05mm or more confirmed after the test by the average length of cracks of 0.05mm or more in length is calculated, and the reciprocal of the numerical value is used as the evaluation value of the ozone resistance index.

[0036] (Weight average molecular weight of various materials used for repair sheets)

[0037] The “weight average molecular weight” can be calculated based on the measured value obtained by gel permeation chromatography (GPC) (for example, GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation) by conversion to standard polystyrene.

[0038] (Tensile strength of resin)

[0039] The "tensile strength of the resin (unit: MPa)" can be determined as the tensile strength (50 mm / min) according to ISO 527-1.

[0040] [Repair sheet]

[0041] The repair sheet of the present disclosure will be described below.

[0042] <Keep Layer>

[0043] The retaining layer can retain the additive, and the retaining layer has a breaking strength of 0.5 MPa or more and an elongation at break of 5% or more. These values ​​are the physical properties of the retaining layer in a state where no additive is retained. Preferably, the retaining layer in a state where the additive is retained (the entire layer consisting of the retaining layer and the additive retained in the retaining layer) also satisfies these physical properties.

[0044] (Breaking Strength)

[0045] From the perspective of ensuring strength during use, the breaking strength (in MPa) of the retaining layer is preferably greater than 0.5, more preferably greater than 1.0, further preferably greater than 1.5, further preferably greater than 2.0, further preferably greater than 3.0, further preferably greater than 5.0, further preferably greater than 10.0, further preferably greater than 15.0, further preferably greater than 17.0. On the other hand, from the perspective of ensuring strength during use, there is no specific upper limit for the breaking strength (in MPa), but the upper limit is usually less than about 40.0, or may be less than 35.0, less than 30.0, less than 25.0 or less than 20.0. These values ​​are the physical properties of the retaining layer in a state where no additive is retained. Preferably, the retaining layer in a state where the additive is retained (the entire layer consisting of the retaining layer and the additive retained in the retaining layer) also satisfies these physical properties.

[0046] (Elongation at break)

[0047] From the perspective of ensuring the followability during use, the elongation at break (in %) of the retaining layer is preferably greater than 5, more preferably greater than 10, further preferably greater than 50, further preferably greater than 100, further preferably greater than 200, further preferably greater than 230, further preferably greater than 300, further preferably greater than 400, further preferably greater than 420, further preferably greater than 500, further preferably greater than 600. On the other hand, from the perspective of ensuring the followability during use, there is no specific upper limit for the elongation at break (in %), but the upper limit is usually less than about 1200, or may be less than 1100, less than 1000, less than 900, or less than 800. These values ​​are the physical properties of the retaining layer in a state where no additive is retained. Preferably, the retaining layer in a state where the additive is retained (the entire layer consisting of the retaining layer and the additive retained in the retaining layer) also satisfies these physical properties.

[0048] (size)

[0049] From the perspective of easy operation, the thickness of the retaining layer is preferably 100 mm or less, more preferably 80 mm or less, more preferably 60 mm or less, and more preferably 50 mm or less. On the other hand, the lower limit of the thickness is not particularly limited (as long as the necessary amount of additives can be retained), but it is usually preferably 0.5 mm or more, more preferably 0.8 mm or more, and more preferably 1 mm or more. These values ​​are the dimensions of the retaining layer in a state where no additive is retained. Preferably, the retaining layer in a state where the additive is retained (the entire layer consisting of the retaining layer and the additive retained in the retaining layer) also meets these dimensions.

[0050] When the purpose is to be attached to the repair sheet of the tire tread, the length of the tire width direction (longitudinal direction) of the retaining layer is preferably no more than the length on the tire width. In addition, the length of the tire circumference (lateral direction) of the retaining layer is preferably no more than the length on the tire periphery.

[0051] (Maintenance of Additives)

[0052] The ratio (in mass %) of the mass of the additive retained by the retaining layer to the total mass of the retaining layer and the mass of the additive is preferably greater than 0.1 mass %, more preferably greater than 15 mass %, and further preferably greater than 25 mass %. On the other hand, there is no specific upper limit to the ratio (in mass %), but the upper limit is usually less than 99.9 mass %, less than 92 mass %, or less than 90 mass %.

[0053] In the case of a repair sheet intended to be attached to a tire tread, the thickness of the retaining layer holding the additive is preferably 110 mm or less, more preferably 88 mm or less, further preferably 66 mm or less, further preferably 55 mm or less. On the other hand, there is no particular restriction on the lower limit of the thickness, but it is usually preferably 0.55 mm or more, more preferably 0.88 mm or more, further preferably 1.1 mm or more. In addition, the longitudinal length of the retaining layer is preferably not more than the tire width plus 10 mm. In addition, the lateral length of the retaining layer is preferably not more than the tire circumference plus 10 mm.

[0054] <Material of the retaining layer>

[0055] The material of the retaining layer is not particularly limited as long as it can retain the additive as described above and has a predetermined breaking strength and breaking elongation. Examples of such materials include, for example, thermoplastic elastomers, resins, cross-linked rubbers, etc. It is preferred that one or two or more of them be used as the material constituting the retaining layer. In addition, there is a case where a resin is used as the material of the retaining layer, and there is another case where a resin is used as the additive, therefore, hereinafter, the resin as the material of the retaining layer shall be referred to as the first resin, and the resin as the material of the additive shall be referred to as the second resin.

[0056] (Thermoplastic Elastomer)

[0057] The thermoplastic elastomer used as the material of the retaining layer is not limited as long as it can retain the additive and form a retaining layer that can be deformed and attached along the shape of the tire and meets predetermined requirements such as breaking strength. Examples of thermoplastic elastomers include, for example, styrene elastomers, polyurethane elastomers, polyester elastomers, etc. Among them, styrene elastomers are preferred. Thermoplastic elastomers can be used alone or in combination of two or more thereof.

[0058] As the styrene-based elastomer, a thermoplastic elastomer containing a styrene block can be appropriately used. The thermoplastic elastomer containing a styrene block comprises a soft segment and a hard segment of a polystyrene block. A typical soft segment is a diene block. Examples of constituents of the diene block include butadiene, isoprene, 1,3-pentadiene and 2,3-dimethyl-1,3-butadiene, wherein butadiene and isoprene are preferred. One or more constituents can be used as constituents of the diene block.

[0059] Thermoplastic elastomers containing styrene blocks include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), styrene-isobutylene-styrene block copolymers (SIBS), hydrides of SBS, hydrides of SIS, and hydrides of SIBS. Examples of hydrides of SBS include styrene-ethylene-butylene-styrene block copolymers (SEBS), styrene-butadiene-butylene-styrene block copolymers (SBBS). Examples of hydrides of SIS include styrene-ethylene-propylene-styrene block copolymers (SEPS). Among them, SEBS is preferred.

[0060] From the perspective of obtaining the retaining layer of the present disclosure, the content of the styrene component in the thermoplastic elastomer containing the styrene block is preferably greater than 10% by mass, more preferably greater than 12% by mass, and further preferably greater than 15% by mass. From the same perspective, the content is preferably less than 50% by mass, more preferably less than 47% by mass, and further preferably less than 45% by mass.

[0061] Examples of polyurethane elastomers include thermoplastic elastomers having multiple urethane bonds in the main chain of the molecule. Polyurethane is preferably a polyurethane obtained by reacting a polyisocyanate component with a polyol component. Examples of polyisocyanate components include diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HMDI), etc.

[0062] As the polyester-based thermoplastic elastomer, a polyester-based thermoplastic elastomer having a soft segment of an olefin-based elastomer and a hard segment of polyethylene terephthalate, polybutylene terephthalate, etc. is preferably used. Examples of the olefin-based elastomer include olefin-based elastomers obtained by homopolymerizing one selected from a linear olefin having 1 to 8 carbon atoms, a branched olefin, and polyvinyl acetate, or copolymerizing two or more thereof, particularly ethylene-vinyl acetate copolymers, ethylene-propylene copolymers, linear low-density polyethylene, etc.

[0063] (First resin)

[0064] The first resin used as the material of the retaining layer is not limited as long as it can retain the additive and form a retaining layer that can be deformed and attached along the shape of the tire, meeting predetermined requirements such as breaking strength. Plastics or resins commonly used in the tire industry can be used as such first resins. The first resin is solid at 25°C. The softening temperature of the first resin is preferably higher than 60°C, more preferably higher than 70°C, and further preferably higher than 80°C. The softening temperature of the first resin is a value (so-called Vicat softening point) measured by the A50 method (test load: 10N, heating rate: 50°C / h) according to JIS K7206. Examples of the first resin include, for example, alkylphenol-based resins, coumarone-indene resins, terpene-based resins, styrene-based resins, rosin-based resins, acrylic resins, dicyclopentadiene resins (DCPD resins), etc. Among them, styrene-based resins are preferred. Examples of styrene-based resins include resins that are homopolymers of α-methylstyrene or styrene, resins that are copolymers of at least one of α-methylstyrene and styrene with butadiene, etc. Among them, styrene-butadiene copolymer resins, etc. are preferred. The first resin may be used alone, or two or more thereof may be used in combination.

[0065] As alkylphenol resins, for example, alkylphenol resins manufactured by BASF and Tanaoka Chemical Co., Ltd. can be used. As benzofuran-indene resins, for example, benzofuran-indene resins manufactured by Nippon Steel Chemical Materials Co., Ltd. and Innolux Co., Ltd. can be used. As terpene resins, for example, terpene resins manufactured by Kraton and Yasuhara Chemical Co., Ltd. can be used. As styrene resins, for example, styrene resins manufactured by Asahi Kasei Corporation and Kraton can be used. As rosin resins, for example, rosin resins manufactured by Harima Chemicals Group Co., Ltd. and Arakawa Chemical Industries, Ltd. can be used.

[0066] From the perspective of the effects of the present disclosure, the tensile strength (in MPa) of the first resin is preferably 5 or more, more preferably 10 or more, and further preferably 15 or more. In addition, there is no specific upper limit for the tensile strength, but it is usually about 50 or less, or about 40 or less. The tensile strength (in MPa) of the first resin is measured by the method for measuring the tensile strength of the resin as described above.

[0067] (Cross-linked rubber)

[0068] The crosslinked rubber used as the material of the retaining layer is not limited as long as it can retain the additive and form a retaining layer that can be deformed and adhered along the shape of the tire, satisfying predetermined requirements such as breaking strength, etc. Here, the crosslinked rubber refers to a rubber in which chain-like rubber molecules are crosslinked to each other to form a three-dimensional network structure to prevent plastic deformation.

[0069] As the rubber component constituting the cross-linked rubber, cross-linkable rubber components commonly used in the tire industry can be used, and examples thereof include: for example, natural rubber (NR), isoprene rubber (IR) and other isoprene-based rubbers, styrene-butadiene rubber (SBR), butadiene rubber (BR), styrene-isoprene-butadiene copolymer rubber (SIBR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber, polynorbornene rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, etc. The rubber components can be used alone or in combination of two or more thereof.

[0070] More specifically, for example, NR is not particularly limited, and NR commonly used in the tire industry, such as SIR20, RSS#3, TSR20, etc. can be used. SBR is not particularly limited, and SBR commonly used in the tire industry can be used, and any of emulsion-polymerized styrene-butadiene rubber (E-SBR) and solution-polymerized styrene-butadiene rubber (S-SBR) can be used, and SBR manufactured and sold by JSR Corporation, Sumitomo Chemical Co., Ltd., Ube Industries, Ltd., Asahi Kasei Corporation, ZS Elastomers Co., Ltd., etc. can be used. BR is not particularly limited, and BR commonly used in the tire industry can be used, and BR manufactured and sold by JSR Corporation, Zeon Corporation, Ube Industries, Ltd., etc. can be used.

[0071] <Additives>

[0072] The additive is an additive added to the rubber composition constituting the tire, which has the property of penetrating into the rubber composition to soften the rubber composition, or, if it does not have the property of penetrating into the rubber composition, is an additive used in combination with an additive having the property of penetrating into the rubber composition to soften the rubber composition. The additive preferably includes at least one selected from a plasticizer, an antioxidant, and a vulcanization accelerator. In the present disclosure, the additive is supplied to the rubber composition constituting the tire portion, and preferably penetrates into the tire portion by 0.1 mm or more, more preferably by 1 mm or more, and further preferably by 2 mm or more.

[0073] (Plasticizer)

[0074] Examples of plasticizers include, for example, oil, resin (second resin), liquid rubber, ester plasticizers, etc. Among them, oil, second resin and ester plasticizers are preferred. Among these plasticizers, as additives, it is preferred to use a plasticizer that is liquid at room temperature (25° C.), or to use an additive in combination with a liquid plasticizer. The plasticizer may be used alone, or two or more thereof may be used in combination.

[0075] <<Oil>>

[0076] Examples of oils include, for example, mineral oils, vegetable oils (or fats), or mixtures thereof. Examples of mineral oils include, for example, paraffin oils, aromatic oils, naphthenic oils, etc. Examples of vegetable oils (or fats) include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia oil, tung oil, etc. They can be used alone, or two or more thereof can be used in combination.

[0077] <<Second Resin>>

[0078] The second resin is not particularly limited, and examples thereof include petroleum resins, terpene resins, rosin resins, phenolic resins, etc. commonly used in the tire industry. Among them, petroleum resins are preferred. The second resin can be used alone, or two or more thereof can be used in combination. In addition, when the first resin is used as the material of the retaining layer, the second resin as a plasticizer is selected to be a resin of a different type from the first resin.

[0079] Examples of the petroleum resin include C5-based petroleum resin, aromatic petroleum resin, C5-C9-based petroleum resin, etc. Among them, aromatic petroleum resin is preferred.

[0080] "C5-based petroleum resin" refers to a resin obtained by polymerizing a C5 fraction. Examples of the C5 fraction include, for example, petroleum fractions having 4 to 5 carbon atoms, such as cyclopentadiene, pentene, pentadiene, isoprene, etc. As the C5-based petroleum resin, dicyclopentadiene resin (DCPD resin) is preferably used.

[0081] "Aromatic petroleum resin" refers to a resin obtained by polymerizing a C9 fraction, which can be hydrogenated or modified. Examples of C9 fractions include, for example, petroleum fractions having 8 to 10 carbon atoms, such as vinyltoluene, alkylstyrene, indene, methylindene, etc. As specific examples of aromatic petroleum resins, for example, benzofuran-indene resins and aromatic vinyl resins are suitably used. Among them, benzofuran-indene resins are preferred. For reasons of economy, easy processing, and excellent heat generation, as aromatic vinyl resins, homopolymers of α-methylstyrene or styrene, or copolymers of α-methylstyrene and styrene, more preferably copolymers of α-methylstyrene and styrene, are preferred. As aromatic vinyl resins, for example, commercially available aromatic vinyl resins from Kraton, Eastman Chemical Company, etc. can be used.

[0082] "C5-C9-based petroleum resin" refers to a resin obtained by copolymerizing a C5 fraction and a C9 fraction, and may be hydrogenated or modified. Examples of the C5 fraction and the C9 fraction include the above-mentioned petroleum fractions. As the C5-C9-based petroleum resin, for example, C5-C9-based petroleum resins commercially available from Tosoh Corporation, LUHUA Corporation, etc. can be appropriately used.

[0083] Examples of terpene resins include: polyterpene resins composed of at least one selected from terpene compounds such as α-pinene, β-pinene, limonene, dipentene, etc.; aromatic modified terpene resins made from the above terpene compounds and aromatic compounds; terpene phenol resins made from terpene compounds and phenolic compounds; and resins obtained by hydrogenating these terpene resins (hydrogenated terpene resins). Examples of aromatic compounds used as raw materials for aromatic modified terpene resins include, for example, styrene, α-methylstyrene, vinyltoluene, divinyltoluene, etc. Examples of phenolic compounds used as raw materials for terpene phenol resins include, for example, phenol, bisphenol A, cresol, xylenol, etc.

[0084] Examples of rosin-based resins include natural resin rosins such as tall rosin, gum rosin, and wood rosin, and rosin-modified resins obtained by modifying natural resin rosins by hydrogenation, disproportionation, dimerization, esterification, and the like.

[0085] Examples of the phenolic resin include phenolic resin, alkylphenolic resin, alkylphenolacetylene resin, oil-modified phenolic resin, and the like.

[0086] The softening point of the second resin is not particularly limited, but it is preferred that the second resin has a low softening point and is easy to add when it is in a liquid state. Therefore, when considering such a viewpoint, the softening point of the second resin is generally preferably higher than 0°C, more preferably higher than 5°C, and further preferably higher than 10°C. In addition, the softening point of the second resin is preferably lower than 150°C, more preferably lower than 140°C, further preferably lower than 130°C, further preferably lower than 80°C, further preferably lower than 50°C, further preferably lower than 25°C, and further preferably lower than 20°C. In addition, the softening point in this specification can be defined as the temperature at which a ball falls when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point measuring device. In addition, the molecular weight (Mw) of the second resin is preferably 300 or more, and preferably less than 10,000.

[0087] <<Liquid Rubber>>

[0088] The liquid rubber is not particularly limited as long as it is a polymer in a liquid state at normal temperature (25° C.), and examples of the liquid rubber include, for example, a diene polymer having a weight average molecular weight of 50,000 or less, more preferably 10,000 or less, more particularly, liquid butadiene rubber (liquid BR), liquid styrene-butadiene rubber (liquid SBR), liquid isoprene rubber (liquid IR), liquid styrene-isoprene rubber (liquid SIR), liquid farnesene rubber, etc. The liquid rubber may be used alone, or two or more thereof may be used in combination.

[0089] <<Ester plasticizers>>

[0090] Examples of ester plasticizers include, for example, dibutyl adipate (DBA), diisobutyl adipate (DIBA), dioctyl adipate (DOA), di(2-ethylhexyl) azelate (DOZ), dibutyl sebacate (DBS), diisononyl adipate (DINA), diethyl phthalate (DEP), dioctyl phthalate (DOP), diundecyl phthalate (DUP), dibutyl phthalate (DBP), dioctyl sebacate (DOS), tributyl phosphate (TBP), trioctyl phosphate (TOP), triethyl phosphate (TEP), trimethyl phosphate (TMP), thymidine triphosphate (TTP), tricresyl phosphate (TCP), tri(xylene) phosphate (TXP), etc. The ester plasticizers may be used alone or in combination of two or more thereof.

[0091] (Antioxidant)

[0092] Examples of antioxidants include, for example, naphthylamine antioxidants such as phenyl-α-naphthylamine, etc.; diphenylamine antioxidants such as octylated diphenylamine, 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine, etc.; p-phenylenediamine antioxidants such as N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, etc.; quinoline antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline, etc.; monophenol antioxidants such as 2,6-di-tert-butyl-4-methylphenol, styrenated phenol, etc.; bisphenol, trisphenol or polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, etc. As commercially available products, for example, products manufactured by Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Co., Ltd., Flexsys Co., Ltd., etc. can be used. The antioxidant may be used alone, or two or more thereof may be used in combination.

[0093] (Vulcanization accelerator)

[0094] Examples of the vulcanization accelerator include, for example, sulfenamide vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, thiourea vulcanization accelerators, guanidine vulcanization accelerators, dithiocarbamic acid vulcanization accelerators, aldehyde-amine or aldehyde-ammonia vulcanization accelerators, imidazoline vulcanization accelerators, and xanthate vulcanization accelerators.

[0095] Examples of sulfonamide vulcanization accelerators include CBS (N-cyclohexyl-2-benzothiazole sulfonamide), TBBS (N-tert-butyl-2-benzothiazole sulfonamide), N-oxyethylene-2-benzothiazole sulfonamide, N,N'-diisopropyl-2-benzothiazole sulfonamide, N,N-dicyclohexyl-2-benzothiazole sulfonamide, etc. Examples of thiazole vulcanization accelerators include 2-mercaptobenzothiazole, dibenzothiazolyl disulfide, etc. Examples of thiuram vulcanization accelerators include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetrabenzylthiuram disulfide (TBzTD), etc. Examples of guanidine vulcanization accelerators include diphenylguanidine (DPG), di-o-tolylguanidine, o-tolylbiguanide, etc. They can be used alone, or two or more of them can be used in combination.

[0096] Other additives may be materials generally used for tires. Examples of other additives include, for example, waxes other than the above-mentioned vulcanization accelerators, surfactants, and vulcanization chemicals.

[0097] <Repair Sheet>

[0098] Examples of the repair sheet used in the present disclosure include a repair sheet having a retaining layer in a state where the above-mentioned additive is not retained, and a repair sheet having a retaining layer in a state where the above-mentioned additive is retained. When the tire is processed using the repair sheet, the additive is retained in the retaining layer. Retaining the additive in the retaining layer can be configured as: impregnating or injecting the retaining layer in a state where the additive is not retained with the additive, so that the retaining layer is in a state where the additive is retained, or the additive is retained during the preparation process of the retaining layer.

[0099] Preferably, the repair sheet of the present invention is directly attached to the exposed part of the tire part, such as the tread part, the sidewall part, the overlap part and the tire wing part on the outer surface and the inner liner part on the inner surface. In this case, since the repair sheet of the present invention has a predetermined breaking strength and elongation at break, it can be effectively attached to the tire. In addition, the amount of additive supplied to the tire can be adjusted by the time the repair sheet with the additive is in contact with the tire (i.e., the repair time), and the amount of additive retained in the repair sheet. Therefore, the tire can be processed with more effort.

[0100] Preferably, the repair sheet of the present invention has a necessary and sufficient shape and size to cover the tire part. For example, when the repair sheet of the present invention is used to repair the tread, preferably, the longitudinal length of the repair sheet does not exceed the tire width plus 10 mm, the lateral length does not exceed the tire circumference plus 10 mm, and the thickness is 110 mm or less. Those skilled in the art can determine the necessary and sufficient shape and size of the repair sheet of the present invention according to the shape and size of the tire part.

[0101] (Support layer)

[0102] The repair sheet of the present disclosure may have a support layer that supports the retaining layer. When the repair sheet includes the support layer, the following advantage can be obtained: the repair sheet becomes easy to handle until the retaining layer holding the additive is attached to the tire. Preferably, the support layer is a support layer that does not inhibit the deformation of the retaining layer when the repair sheet is attached to the tire, and examples thereof include, for example, a support layer composed of a material that is easier to stretch than the retaining layer (e.g., rubber, thermoplastic elastomer, etc.).

[0103] <Manufacturing method>

[0104] Next, a method for producing the repairing sheet of the present disclosure will be described.

[0105] (Keep Layer)

[0106] The retaining layer included in the repairing sheet can be manufactured by molding a predetermined material so that it can retain the additive and has a predetermined breaking strength and breaking elongation. Those skilled in the art can select such a predetermined material and appropriately set the conditions for molding the selected material.

[0107] <<Retention layer made of thermoplastic elastomer>>

[0108] For example, a retaining layer made of a thermoplastic elastomer (substrate) can be manufactured by press-molding a material containing a granular thermoplastic elastomer. The pressure, time and temperature of the press-molding can be appropriately set in a suitable combination according to the type of thermoplastic elastomer. Usually, the pressure (unit: MPa) of the press-molding is preferably greater than 0.1, more preferably greater than 0.2, and further preferably greater than 0.4. On the other hand, the pressure is preferably less than 30, more preferably less than 25, and further preferably less than 20. The time of press-molding is preferably greater than 1 minute, more preferably greater than 2 minutes, and further preferably greater than 3 minutes. On the other hand, the time is preferably less than 20 minutes, more preferably less than 15 minutes, and further preferably less than 10 minutes. The temperature of the press-molding can be appropriately set according to the type of thermoplastic elastomer used.

[0109] As described above, the fracture strength of the retaining layer can be adjusted by selecting the type of thermoplastic elastomer used and by kneading the thermoplastic elastomer in advance with a material other than the additives disclosed herein (e.g., a reinforcing material that does not penetrate into the tire, such as carbon black, silica, etc.). For example, the fracture strength can be increased by kneading a larger amount of reinforcing material, and conversely, the fracture strength can be reduced by kneading a smaller amount of reinforcing material. The reinforcing material can be kneaded into the material constituting the retaining layer using a Banbury mixer or the like. In addition, as described above, when a material other than the additive (e.g., a reinforcing material) is used as the material of the retaining layer, the material (reinforcing material) can be regarded as a component of the retaining layer (the same applies below).

[0110] The elongation at break of the retaining layer can be adjusted by selecting the kind of thermoplastic elastomer used and by kneading the thermoplastic elastomer in advance with materials other than the additives of the present disclosure (e.g., reinforcing materials that do not permeate into the tire, for example, carbon black, silica, etc.).

[0111] <<Retention layer made of first resin>>

[0112] For example, a retaining layer made of a first resin (substrate) can be manufactured by press-molding a material including a granular first resin. The pressure, time and temperature of the press-molding can be appropriately set in a suitable combination according to the type of the first resin. Usually, the pressure (unit: MPa) of the press-molding is preferably greater than 0.1, more preferably greater than 0.2, and further preferably greater than 0.4. On the other hand, the pressure is preferably less than 30, more preferably less than 25, and further preferably less than 20. The time of the press-molding is preferably greater than 1 minute, more preferably greater than 2 minutes, and further preferably greater than 3 minutes. On the other hand, the time is preferably less than 20 minutes, more preferably less than 15 minutes, and further preferably less than 10 minutes. The temperature of the press-molding can be appropriately set according to the type of the first resin used.

[0113] As described above, the breaking strength of the retaining layer can be adjusted by selecting the type of the first resin used. For example, the breaking strength can be increased by using a first resin with a higher strength such as tensile strength, and conversely, the breaking strength can be reduced by using a first resin with a lower strength.

[0114] The elongation at break of the retaining layer can be adjusted by selecting the kind of the first resin used and by kneading the first resin in advance with materials other than the additives of the present disclosure (eg, reinforcing materials that do not permeate into the tire, such as carbon black, silica, etc.).

[0115] <<Retention layer made of cross-linked rubber>>

[0116] For example, a holding layer made of a crosslinked rubber (base material) can be produced by crosslinking chain rubber molecules with a co-crosslinking agent, an organic peroxide, sulfur, or the like.

[0117] As above, the breaking strength of the retaining layer can be increased by making the crosslinking denser and by kneading the crosslinked rubber in advance with materials other than the additives of the present disclosure (e.g., reinforcing materials that do not penetrate into the tire, such as carbon black, silica, etc.). Conversely, the breaking strength can be reduced by making the crosslinking sparser and by reducing the amount of reinforcing materials to be kneaded.

[0118] Even if the material (base material) of the holding layer is composed of a combination of two or more selected from the thermoplastic elastomer, the first resin and the crosslinked rubber, the intended holding layer can be manufactured by appropriately referring to the manufacturing methods when using the above-mentioned various materials.

[0119] (Repair sheet with additives)

[0120] The additive can be retained in the retaining layer by immersing the retaining layer in the additive or injecting the additive into the retaining layer. The additive can be added at room temperature or in a heating temperature range that does not affect the structure or function of the retaining layer. Alternatively, after mixing the material (base material) of the retaining layer and the additive, compression molding can be performed according to the above-mentioned manufacturing method. However, it is preferred that the retaining layer is immersed in the additive or the additive is injected into the retaining layer because this can adjust the amount of the additive.

[0121] (Repair sheet with support layer)

[0122] A repair sheet provided with a support layer can be manufactured by bonding a retaining layer before the support layer is provided to the support layer. There is no particular limitation on bonding, as long as the retaining layer before the support layer is provided can be bonded to the support layer with an adhesive force not less than the necessary minimum adhesive force regardless of the means used. For example, if the two layers are bonded by themselves, bonding can be implemented in this way; or, if necessary, bonding can also be implemented by using a suitable adhesive. However, if the support layer is to be separated during use, the bonding is preferably bonding with an adhesive force within a range that allows easy separation. In addition, the "necessary minimum adhesive force" refers to the minimum adhesive force required for bonding the support layer and the retaining layer from the point in time when the support layer is bonded to the retaining layer until the support layer is peeled off from the repair sheet.

[0123] [Tire repair method]

[0124] The tire repair method of the present disclosure is a tire repair method including the steps of attaching a repair sheet to a tire site and supplying an additive into the tire site.

[0125] The tire repair method disclosed herein can be performed as follows: the repair sheet is directly attached to the exposed portion of the tire part (for example, the tread portion on the outer surface, the sidewall portion, the overlap portion, the tire wing portion, the inner liner portion on the inner surface, etc.). In this case, since the repair sheet has a predetermined breaking strength and breaking elongation, it can be effectively attached to the tire. In addition, the amount of additive supplied to the tire can be adjusted by the time the repair sheet retaining the additive is in contact with the tire (i.e., the repair time) and by the amount of the additive retained in the repair sheet. Therefore, the tire can be processed more labor-savingly.

[0126] Furthermore, unless there is any particular contradiction, the above description on the repairing sheet can also be applied to the description of the repairing method.

[0127] [use]

[0128] The repair sheet disclosed in the present invention can be used to repair tires used in a variety of vehicles (for example, large vehicles such as passenger cars, trucks or buses, motorcycles, racing cars, industrial vehicles, special vehicles, load vehicles such as trailers or cranes, etc.). In addition, such tires are not limited to pneumatic tires, and can be non-pneumatic tires. In particular, in studless anti-skid tires, in order to obtain the ground contact surface effect and edge effect on icy and snowy roads, a larger amount of additives are compounded compared to ordinary tires, so that the hardening of the rubber is easy to proceed over time. Therefore, the repair sheet disclosed in the present invention can be appropriately used. There is no particular limitation on the tire part to which the repair sheet disclosed in the present invention is applied, but it is generally the tread portion, sidewall portion, overlap portion, tire wing portion, inner liner portion, etc. that constitute the surface (including the outer surface or inner surface) of the tire. In particular, the repair sheet can be appropriately applied to the tread portion.

[0129] Example

[0130] Hereinafter, the present invention will be described based on Examples, but the present invention is not limited to these Examples.

[0131] The materials used in Examples and Comparative Examples are summarized below.

[0132] Thermoplastic elastomer: Tuftec (registered trademark) P1500 manufactured by Asahi Kasei Corporation (hydrogenated styrene-based thermoplastic elastomer, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene / ethylene-butylene-butadiene ratio: 30 / 70)

[0133] First resin: Asaflex (registered trademark) 815 manufactured by Asahi Kasei Corporation (styrene resin, styrene-butadiene copolymer resin (SBC), tensile strength (50 mm / min): 27 MPa, Vicat softening point: 82° C.)

[0134] Cross-linked rubber: the cross-linked rubber obtained in the following Production Example 1

[0135] Oil: PS-32 (mineral oil) manufactured by Idemitsu Kosan Co., Ltd.

[0136] Second resin: NOVARES C10 (liquid coumarone-indene resin) manufactured by Rutgers Chemical Company

[0137] · Ester plasticizer: Bis(2-ethylhexyl) sebacate (dioctyl sebacate) manufactured by Daihachi Chemical Industry Co., Ltd.

[0138] Antioxidant: Nocrac 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0139] [Experimental Example 1]

[0140] <Repair Sheet>

[0141] (Keep layer 1)

[0142] The granular thermoplastic elastomer was pressed using a rubber pressing machine at 170°C, 5 minutes, and 1 MPa to produce a retaining layer 1 (repairing sheet). The retaining layer 1 thus obtained was cut into a size of 20 mm in the longitudinal direction (tire width direction) × 30 mm in the transverse direction (tire circumferential direction) × 2 mm in thickness.

[0143] (Keep layer 2)

[0144] The granular first resin was pressed using a vacuum press molding machine at 140°C, 5 minutes, and 10 MPa to produce a retaining layer 2 (repairing sheet). The retaining layer 2 thus obtained was cut into a size of 20 mm in the longitudinal direction (tire width direction) × 30 mm in the transverse direction (tire circumferential direction) × 2 mm in thickness.

[0145] (Keep layer 3)

[0146] The crosslinked rubber was pressed using a rubber vulcanization press molding machine at 170°C, 20 minutes, and 10 MPa to produce a retaining layer 3 (repairing sheet). The retaining layer 3 thus obtained was cut into a size of 20 mm in the longitudinal direction (tire width direction) × 30 mm in the transverse direction (tire circumferential direction) × 2 mm in thickness.

[0147] The breaking strength and breaking elongation of the holding layer 1, the holding layer 2, and the holding layer 3 obtained above were measured as follows.

[0148] (Breaking strength, breaking elongation)

[0149] A dumbbell-shaped No. 7 test piece with a thickness of 1 mm was prepared and cut so that the transverse direction (tire circumferential direction) of the retaining layer 1, retaining layer 2 and retaining layer 3 became the stretching direction. According to JIS K 6251 "Vulcanized rubber or thermoplastic rubber - Determination of tensile stress-strain properties", a tensile test was carried out in an atmosphere of 23°C at a tensile speed of 3.3 mm / sec to measure the breaking strength (TB) (MPa) and the breaking elongation (EB) (%).

[0150] Table 1

[0151]

[0152] <Repairing sheet with additives>

[0153] Using the above-obtained repairing sheet, namely, the retaining layer 1, the retaining layer 2 or the retaining layer 3, the additives were impregnated under the impregnation conditions shown in Table 2 below to produce repairing sheets 1 to 10 in which the additives were retained at the ratios shown in Table 2.

[0154] Table 2

[0155]

[0156] <Tire Repair>

[0157] Used tire 0 and used tires 1 to 3 were prepared (each of which was WINTER MAXX 02 (Sumitomo Rubber Industries, Ltd.) manufactured in 2018; 2-year-old products; the same template). These tires were all installed on the same vehicle. Among them, used tire 0 was used for the comparative example, and used tires 1 to 3 were used for the examples. As shown in Table 3, used tire 0 in the comparative example was directly sent for tire evaluation without any repair. On the other hand, at room temperature (25°C), under the conditions shown in Table 3, used tires 1 to 3 in the examples were repaired and then sent for tire evaluation.

[0158] <Evaluation of Tires>

[0159] Each tire was evaluated as follows. The results are shown in Table 3.

[0160] (Content of additives)

[0161] According to JIS K 6229, the content of the additive was determined as the amount of extractable by immersing a sample cut out from the tread surface of each tire in acetone for 24 hours, extracting the soluble components, and measuring the mass of each sample before and after the extraction, using the following formula. The content is expressed as an index, where the amount (%) of the extractable in Comparative Example 1 is 100. The higher the numerical value, the greater the amount of the extractable, i.e., the content of the additive.

[0162] Amount of extract (%) = {(mass of sample before extraction - mass of sample after extraction) / (mass of sample before extraction)} × 100

[0163] (hardness)

[0164] A sample for measuring hardness was cut out from the tread portion forming the ground contact surface of each tire so that the tire radial direction became the thickness direction, and a type A durometer was pressed to the sample from the ground contact surface side at 23° C. to measure the rubber hardness in accordance with JIS K 6253. The reciprocal value of the hardness was expressed as an index, wherein the case of Comparative Example 1 was 100. The higher the value, the lower the hardness and the softer the rubber.

[0165] (Wet grip performance and ice performance)

[0166] Regarding the wet grip performance, the road friction coefficient was measured using an internal drum tester at a drum speed of 20 km / h under wet road conditions (25°C, water depth of 5 mm) with the slip ratio varying from 0 to 30%. The road friction coefficient thus obtained was expressed as an index (wet grip performance index), where the case of Comparative Example 1 was 100. The higher the value, the higher the wet grip performance.

[0167] Regarding the on-ice performance, the same measurement as the wet grip performance index is performed except that frozen road conditions (-1°C, on ice) are used instead of wet road conditions to obtain the on-ice performance index. The higher the value, the higher the on-ice performance.

[0168] Table 3

[0169]

[0170] As can be seen from Table 3, as a result of the repair, the content of the additive in the tread portion in the example is increased, the hardness of the tread portion is reduced to soften the tread portion, and further, both the wet grip performance and the performance on ice are improved, compared with the comparative example.

[0171] [Experimental Example 2]

[0172] The same process as in Experimental Example 1 was performed, except that used tire 4 and used tire 5 (each of which was WINTER MAXX 02 (Sumitomo Rubber Industries, Ltd.) manufactured in 2018; 2-year-old tire; same template) were prepared as tires for repair, and a second resin and an ester plasticizer were used as additives retained in the retaining layer 1, and the process was performed according to Table 4, to obtain the results of Example 4 and Example 5.

[0173] Table 4

[0174]

[0175] As can be seen from Table 4, as a result of repair, the content of the additive in the tread portion in the example is increased compared to the comparative example, the hardness of the tread portion is reduced to soften the tread portion, and further, both the wet grip performance and the performance on ice are improved.

[0176] [Experimental Example 3]

[0177] The same process as in Experimental Example 1 was performed, except that used tires 6 to 8 (each of which was WINTER MAXX 02 (Sumitomo Rubber Industries, Ltd.) manufactured in 2018; 2-year-old tires; same template) were prepared as tires for repair, an antioxidant was used as an additive retained in the retaining layer 1, ozone resistance was evaluated, and the process was performed according to Table 5 to obtain the results of Examples 6 to 8.

[0178] (Ozone resistance)

[0179] According to JIS K 6259 "Vulcanized rubber or thermoplastic rubber - Determination of ozone resistance", ozone resistance is evaluated by preparing a test piece of a predetermined size from the surface of the tread portion and subjecting the test piece to a dynamic ozone degradation test. Specifically, under the conditions of an ozone concentration of 50±5pphm, a test temperature of 40°C, and a tensile strain of 10±2%, the test piece is subjected to a reciprocating motion test with a frequency of 0.5±0.025Hz for 48 hours, and after the experiment, the state of cracks generated on the test piece (the presence or absence of cracks, the number of cracks, the length of cracks, etc.) is observed. The method described in JIS K 6259 (Method A: Crack state observation method) is used as an evaluation method. Specifically, a numerical value indicating the degree of crack generation defined by multiplying the number of cracks of 0.05mm or more confirmed after the test by the average length of cracks of 0.05mm or more in length is calculated, and the reciprocal of the numerical value is used as the evaluation value of the ozone resistance index. Therefore, it can be said that the higher the value is than the ozone resistance index 100 in Comparative Example 2 which is the evaluation standard, the less cracks are generated and the smaller the size of the cracks is, indicating that the ozone resistance is excellent.

[0180] Table 5

[0181]

[0182] As can be seen from Table 5, as a result of the repair, the content of the additive in the tread portion in the example is increased compared to the comparative example, and the ozone resistance of the tread portion is improved.

[0183] [Experimental Example 4]

[0184] The same process as in Experimental Example 1 was carried out, except that used tires 9 to 11 (each of which was WINTER MAXX 02 (Sumitomo Rubber Industries, Ltd.) manufactured in 2018; 2-year-old tires; same template) were prepared as tires for repair, and retaining layer 2 was used as the retaining layer, and the process was carried out according to Table 6, to obtain the results of Examples 9 to 11.

[0185] Table 6

[0186]

[0187] According to Table 6, as a result of repair, the content of the additive in the tread portion in the example is increased, the hardness of the tread portion is reduced to soften the tread portion, and further, both the wet grip performance and the performance on ice are improved, compared with the comparative example.

[0188] [Experimental Example 5]

[0189] Used tires 12 to 15 (all of which were WINTER MAXX 02 (Sumitomo Rubber Industries, Ltd.) manufactured in 2018; 2-year-old products; the same template) were prepared as tires for repair. These tires were all mounted on the same vehicle. The same process as in Experimental Example 1 was performed, except that the used tire 12 was used in the comparative example, the used tires 13 to 15 were used in the examples, the retaining layer 3 was used as the retaining layer, and the process was performed according to Table 7, to obtain the results of Examples 12 to 14.

[0190] Table 7

[0191]

[0192] As can be seen from Table 7, as a result of repair, the content of the additive in the tread portion in the example is increased compared to the comparative example, the hardness of the tread portion is reduced to soften the tread portion, and further, the wet grip performance and the performance on ice are improved.

[0193] Production Example 1

[0194] A cross-linked rubber was produced according to the formulation shown in Table 8. That is, among the components listed in Table 8, the components other than sulfur and the vulcanization accelerator were kneaded, and then sulfur and the vulcanization accelerator were added to the kneaded product, and further kneaded to obtain a kneaded product. For kneading, a general-purpose closed kneading machine for rubber kneading and two rolls were used. The kneaded product was vulcanized at 170° C. for 20 minutes to obtain a cross-linked rubber composition.

[0195] Table 8

[0196]

[0197] [Implementation Method]

[0198] Examples of implementations of the present disclosure are as follows.

[0199] [1] A repair sheet for attachment to a tire portion, the repair sheet comprising:

[0200] a retaining layer capable of retaining an additive for delivery into the tire region,

[0201] Among them, the breaking strength of the retaining layer is 0.5 MPa or more, preferably greater than 0.5 MPa, more preferably greater than 1.0 MPa, further preferably greater than 1.5 MPa, further preferably greater than 2.0 MPa, further preferably greater than 3.0 MPa, further preferably greater than 5.0 MPa, further preferably greater than 10.0 MPa, further preferably greater than 15.0 MPa, further preferably greater than 17.0 MPa, and the breaking elongation is 5% or more, preferably greater than 5%, more preferably greater than 10%, more preferably greater than 50%, further preferably greater than 100%, further preferably greater than 200%, further preferably greater than 230%, further preferably greater than 300%, further preferably greater than 400%, further preferably greater than 420%, further preferably greater than 500%, further preferably greater than 600%.

[0202] [2] The repair sheet according to [1] above, wherein the retaining layer contains at least one selected from the group consisting of a thermoplastic elastomer, a resin, and a cross-linked rubber.

[0203] [3] The repair sheet according to [1] or [2] above, wherein the thickness of the retaining layer is 100 mm or less, preferably 80 mm or less, more preferably 60 mm or less, and even more preferably 50 mm or less.

[0204] [4] The repairing sheet according to any one of [1] to [3] above, further comprising a support layer that supports the holding layer.

[0205] [5] The repair sheet according to any one of [1] to [4] above, wherein the additive is retained in a retaining layer.

[0206] [6] The repair sheet according to [5] above, wherein the additive contains at least one selected from the group consisting of a plasticizer, an antioxidant, and a vulcanization accelerator.

[0207] [7] A method for repairing a tire, the method comprising the following steps:

[0208] a step of attaching the repair sheet described in [5] or [6] above to a tire portion, and

[0209] The step of delivering the additive into the tire region.

[0210] [8] The repair method according to [7] above, wherein the longitudinal length of the retaining layer does not exceed the tire width plus 10 mm, the lateral length does not exceed the tire circumference plus 10 mm, and the thickness is not more than 110 mm, and

[0211] The tire portion is the tread portion of the tire.

Claims

1. A repair sheet for attaching to a tire portion, the repair sheet comprising: a retaining layer capable of retaining an additive for delivery into a tire region, and a supporting layer, the supporting layer supporting the retaining layer; The holding layer has a breaking strength of 0.5 MPa or more and a breaking elongation of 5% or more.

2. The repair sheet according to claim 1, wherein: The retaining layer includes at least one selected from the group consisting of a thermoplastic elastomer, a resin, and a cross-linked rubber.

3. The repair sheet according to claim 1 or 2, wherein: The thickness of the retaining layer is less than 100 mm.

4. The repair sheet according to any one of claims 1 or 2, wherein The additive is retained in the retaining layer.

5. The repair sheet according to claim 4, wherein: The additive comprises at least one selected from the group consisting of a plasticizer, an antioxidant and a vulcanization accelerator.

6. A tire repair method, the repair method comprising the following steps: The step of attaching the repair sheet according to claim 4 or 5 to a tire portion, and The step of delivering the additive into the tire region.

7. The repair method according to claim 6, wherein: The longitudinal length of the retaining layer does not exceed the tire width plus 10mm, the transverse length does not exceed the tire circumference plus 10mm, and the thickness is less than 110mm. The tire portion is the tread portion of the tire.

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