Fiber sheet

Abstract

To provide a new fiber sheet joined to a rubber member.SOLUTION: A fiber sheet in a certain aspect contains a thermoplastic resin fiber, and a non-thermoplastic fiber, wherein the thermoplastic resin fiber is 30 to 80 mass% based on the total mass, the non-thermoplastic fiber is 20 to 70 mass% based on the total mass, and a mass ratio (thermoplastic resin fiber / non-thermoplastic fiber) of the thermoplastic resin fiber to the non-thermoplastic fiber is 3 / 7 to 8 / 2, and the fiber sheet is joined to a rubber member.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fibrous sheet. [Background technology]

[0002] Generally, rubber members have poor bonding properties with other materials. Therefore, various surface treatment methods have been proposed to improve the bonding properties of rubber members with different materials, such as resin members and metal members, and to form composites.

[0003] For example, Patent Document 1 proposes a surface treatment method for improving the bonding between a rubber member and a dissimilar material by irradiating the surface of vulcanized rubber with ultraviolet light. This method activates the surface of the vulcanized rubber, making it easy to combine the rubber member with a dissimilar material. Furthermore, the ultraviolet irradiation device used in this method is simpler than other surface treatment devices and can efficiently treat the surface of the vulcanized rubber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-139901 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the method disclosed in Patent Document 1 can improve the efficiency of the surface treatment itself, it has the problem of being time-consuming and labor-intensive in that, after the surface treatment, an adhesive must be applied to the rubber surface and then cured.

[0006] Furthermore, adhesives generally used for joining (particularly polyurethane adhesives) may not provide sufficient adhesion between rubber members and dissimilar materials.

[0007] Therefore, an object of the present invention is to provide a novel fiber sheet to be bonded to a rubber member. The fiber sheet of the present invention is a fiber sheet that has excellent adhesive strength, durability, and thermocompression bonding properties between a rubber member and a different material such as a resin or metal.

[0008] Certain aspects of the present disclosure include: The fiber sheet contains thermoplastic resin fibers and non-thermoplastic fibers, the thermoplastic resin fibers account for 30 to 80 mass% of the total mass, the non-thermoplastic fibers account for 20 to 70 mass% of the total mass, and the mass ratio of the thermoplastic resin fibers to the non-thermoplastic fibers (the thermoplastic resin fibers / the non-thermoplastic fibers) is 3 / 7 to 8 / 2, and is to be bonded to a rubber member. The porosity of the fiber sheet is preferably 20 to 70%. The melting temperature of the thermoplastic resin fibers contained in the fiber sheet is 110 to 250°C, The thermoplastic resin fibers preferably have a glass transition temperature of 80° C. or lower. The thermoplastic resin fibers preferably contain at least one of polyester, polyolefin, polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyamide, polyurethane polylactic acid, and polyglycol. The fiber sheet is preferably produced by a wet papermaking method. The arithmetic mean surface roughness (Ra) of the main surface of the fiber sheet on the side to be bonded to the rubber member is preferably 5 to 20 μm. The rubber member preferably contains at least one of natural rubber (NR), styrene butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). [Effects of the Invention]

[0009] The disclosed technology provides a novel fiber sheet that can be bonded to a rubber member. The fiber sheet of the disclosed technology has excellent adhesive strength, durability, and thermocompression bonding properties between the rubber member and dissimilar materials such as resin and metal, making it easy to composite the rubber member with dissimilar materials such as resin and metal. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following.

[0011] In this specification, the expression "a to b" in the description of a numerical range means that the range is from a to b, unless otherwise specified.

[0012] <<<Fiber sheet>>> The fiber sheet of the present disclosure contains thermoplastic resin fibers and non-thermoplastic fibers, the thermoplastic resin fibers accounting for 30 to 80 mass% of the total mass of the fiber sheet, and the non-thermoplastic fibers accounting for 20 to 70 mass% of the total mass of the fiber sheet. The fiber sheet of the present disclosure is characterized in that the mass ratio of thermoplastic resin fibers to non-thermoplastic fibers (thermoplastic resin fibers / non-thermoplastic fibers) is 3 / 7 to 8 / 2 (more preferably 3 / 6 to 7 / 2), and is bonded to a rubber member. The fiber sheet of the present disclosure has excellent adhesive strength, durability, and thermocompression bondability between rubber members and dissimilar materials such as resins and metals, and therefore can easily combine rubber members with dissimilar materials such as resins and metals.

[0013] When the thermoplastic resin fiber content in the fiber sheet, the non-thermoplastic fiber content in the fiber sheet, and the mass ratio of the thermoplastic resin fibers to the non-thermoplastic fibers (thermoplastic resin fibers / non-thermoplastic fibers) are within the above-mentioned ranges, the amount of melted components in the fiber sheet increases when the fiber sheet is thermocompression-bonded to a rubber member, improving the bonding strength. Furthermore, since the porosity of the fiber sheet can be set within a predetermined range, the rubber components of the rubber member can sufficiently penetrate into the sheet when the fiber sheet is thermocompression-bonded to a rubber member, improving the bonding strength.

[0014] The porosity of the fiber sheet is not particularly limited, but is preferably 10 to 80%, more preferably 15 to 75%, even more preferably 20 to 70%, and particularly preferably 25 to 65%. When the porosity of the fiber sheet is within this range, the rubber component sufficiently penetrates into the fiber sheet when the rubber member is thermocompression-bonded to the sheet, improving the adhesive strength (or compression strength) between the rubber member and the fiber sheet. Furthermore, when the rubber member is thermocompression-bonded to the fiber sheet, the rubber component does not bleed into the sheet, preventing poor appearance. Therefore, a fiber sheet with excellent adhesive strength, durability, and thermocompression-bondability between the rubber member and different materials such as resins and metals can be obtained.

[0015] The porosity of the fiber sheet is calculated by the following formula (1): The porosity is the value of the fiber sheet before heat pressing in the manufacturing process described below. The porosity is calculated by calculating the thickness (A) when the porosity is 0% from the specific gravity, weight, and area of ​​the fiber sheet, measuring the actual thickness (B) of the test piece, and using the following formula 1. (Formula 1) Porosity (%)=(1-(A / B))×100

[0016] The porosity of the fiber sheet can be adjusted by the manufacturing method of the fiber sheet described below. For example, when a wet papermaking method is used, the desired porosity can be obtained by adjusting the press pressure in the dehydration and drying steps in the papermaking process and the roll surface temperature in the drying step.

[0017] The arithmetic mean surface roughness (Ra) of the main surface of the fiber sheet that is bonded to the rubber member is not particularly limited, but is preferably 1 to 25 μm, more preferably 4 to 23 μm, even more preferably 5 to 20 μm, and particularly preferably 15 to 20 μm. When the arithmetic mean surface roughness (Ra) of the main surface of the fiber sheet that is bonded to the rubber member is within this range, the rubber component exhibits an anchoring effect when the rubber member is thermocompression-bonded to the sheet, improving the adhesive strength (or compression strength) between the rubber member and the fiber sheet. Furthermore, when the rubber member is thermocompression-bonded to the fiber sheet, the rubber component does not bleed into the sheet, preventing poor appearance. Therefore, a fiber sheet with excellent adhesive strength, durability, and thermocompression-bondability between the rubber member and different materials such as resins and metals can be obtained.

[0018] The arithmetic mean surface roughness (Ra) is measured using a confocal laser microscope (for example, OLS3000 manufactured by Olympus Corporation).

[0019] The arithmetic mean surface roughness (Ra) of the main surface of the fiber sheet that is bonded to the rubber member can be adjusted, for example, by adjusting the fiber length, fiber diameter, and blending amount and blending ratio of the thermoplastic resin fibers and non-thermoplastic fibers that are used as raw materials during manufacturing.

[0020] The thickness of the fiber sheet is not particularly limited, but is preferably 50 to 500 μm, more preferably 50 to 400 μm, and even more preferably 150 to 400 μm.

[0021] The basis weight of the fiber sheet is not particularly limited, but is preferably 50 to 400 g / m 2 is preferable, and 80 to 300 g / m 2 More preferably, 83 to 283 g / m 2 is more preferable.

[0022] <<Thermoplastic resin fiber>> The fiber sheet contains thermoplastic resin fibers. The content of the thermoplastic resin fibers in the fiber sheet is preferably 30 to 80 mass % and more preferably 40 to 70 mass % based on the total mass of the fiber sheet.

[0023] The thermoplastic resin fiber is not particularly limited, but can be a main fiber or a composite fiber. The main fiber refers to a fiber having a substantially single composition in the cross section, such as a fiber with a non-core-sheath structure. More specifically, a fiber having a substantially single composition can be interpreted as a fiber having a substantially uniform composition distribution in the fiber cross section (a fiber having a substantially uniform composition). Note that, as described above, the components constituting the substantially single composition may be composed of one type of thermoplastic resin or two or more types of thermoplastic resin. Furthermore, the cross section of the fiber may be a composite fiber containing multiple materials (for example, a fiber having a core-sheath structure), in which case at least a part or all of the fiber surface may be a thermoplastic resin (for example, when the sheath of the core-sheath structure is a thermoplastic resin). In the case of a composite fiber, all of the materials contained therein may be a thermoplastic resin.

[0024] The material of the thermoplastic resin fiber is not particularly limited, but preferred examples include polyesters such as PET, PBT, and copolyester (Co-PES); polyolefins such as polyethylene, polypropylene, and polyethylene-polypropylene copolymers; polylactic acid (PLA); polyglycolic acid (PGA); polyhydroxybutyrate (PHB); polybutylene succinate (PBS); polybutylene succinate adipate (PBSA); polycaprolactone (PCL); polyvinyl alcohol (PVA); polyamide; polyurethane polylactic acid; and polyglycol. These may be used alone or in combination in any ratio. When these thermoplastic resin fibers are used, they have good water dispersibility during the preparation of papermaking raw materials and high thermal melting properties during papermaking and drying, allowing for easy formation of fiber sheets in the manufacturing process described below.

[0025] Examples of materials other than thermoplastic resins that can be contained in the thermoplastic resin fibers include inorganic fibers such as glass fibers and carbon fibers, inorganic particles (or inorganic fillers) such as titanium oxide, silica, carbon black, graphene, and carbon nanofibers, and organic particles (organic fillers) such as polystyrene particles. These can be used alone or in combination in any ratio.

[0026] The fineness of the thermoplastic resin fiber is preferably 0.5 to 10 dtex, and more preferably 1 to 5 dtex. When the fineness of the thermoplastic resin fiber is within this range, it becomes easy to obtain a fiber sheet that has excellent adhesive strength, durability, and thermocompression bondability between the rubber member and different materials such as resin or metal. The fineness of the thermoplastic resin fiber is measured by the following steps (1-1) to (1-3). (1-1) The fiber length of each of 100 randomly selected thermoplastic resin fibers in the raw material is measured using an optical microscope, and the sum (total fiber length Lt of 100 randomly selected thermoplastic resin fibers) is calculated. (1-2) Furthermore, the total mass (Mt) of the 100 fibers whose fiber lengths have been measured is weighed. (1-3) Calculate the fineness based on the following formula 2. (Formula 2) Fineness (dtex)=9000÷Lt×Mt

[0027] The average fiber length of the thermoplastic resin fibers is preferably 1 to 10 mm, and more preferably 3 to 7 mm. When the average fiber length of the thermoplastic resin fibers is within this range, it becomes easy to obtain a fiber sheet that has excellent adhesive strength, durability, and thermocompression bondability between rubber members and dissimilar materials such as resins and metals. The average fiber length of the thermoplastic resin fibers can be obtained by measuring the fiber length of any 100 fibers in the raw thermoplastic resin fibers using an optical microscope and calculating the number average of the obtained values. Note that the average fiber length of the thermoplastic resin fibers in a fiber sheet or thermoplastic resin fibers taken out of a fiber sheet can also be measured in the same manner as described above.

[0028] The melting temperature of the thermoplastic resin fiber is not particularly limited, but is preferably 100 to 280°C, more preferably 110 to 260°C, even more preferably 110 to 250°C, and particularly preferably 150 to 230°C. If the melting temperature of the thermoplastic resin fiber is within this range, the adhesion between the fiber sheet and the rubber component is further improved when the fiber sheet and the rubber member are thermocompression bonded, and the compression strength is further improved. Furthermore, when a wet manufacturing method such as a wet papermaking method is used to produce a fiber sheet, the fiber sheet must be dried. However, if the melting temperature of the thermoplastic resin fiber is within this range, the fiber sheet can be prevented from sticking to a dryer or the like during drying, thereby improving productivity.

[0029] Here, the melting temperature is a temperature that indicates the fluidity of an amorphous thermoplastic resin or a temperature related to the melting point of a crystalline thermoplastic resin. The melting temperature is close to the melting point of a crystalline thermoplastic resin, but it is not the melting point itself. It is a value determined by a measurement method using a differential scanning calorimeter (DSC) as a result of the combined influence of many conditions. The melting temperature corresponds to the temperature at which the thermoplastic resin begins to flow during the heating process.

[0030] The melting temperature of the thermoplastic resin fiber is measured using a differential scanning calorimeter (e.g., Q200 manufactured by TA Instruments Japan) in a temperature range of 0 to 250°C, at a heating rate of 10°C / min, in a nitrogen atmosphere, by measuring the peak temperature during melting.

[0031] The glass transition temperature of the thermoplastic resin fiber is not particularly limited, but the upper limit is preferably 90° C. or lower, more preferably 80° C. or lower. The lower limit is preferably −50° C. or higher, more preferably −40° C. or higher. When the glass transition temperature of the thermoplastic resin fiber is within this range, the thermoplastic fiber is sufficiently melted when the fiber sheet and the rubber member are thermocompression-bonded, improving the adhesion between the fiber sheet and the rubber member and further improving the compression strength.

[0032] The glass transition temperature of the thermoplastic resin fiber is measured by measuring the baseline shift using a differential scanning calorimeter (for example, Q200 manufactured by TA Instruments Japan) in a temperature range of -50 to 250°C, at a heating rate of 10°C / min, in a nitrogen atmosphere.

[0033] <<Non-thermoplastic fiber>> The fiber sheet contains non-thermoplastic fibers. Non-thermoplastic fibers refer to fibers that do not soften even when heated to their melting point. The content of the non-thermoplastic fibers in the fiber sheet is preferably 20 to 70 mass % and more preferably 30 to 60 mass % based on the total mass of the fiber sheet.

[0034] The non-thermoplastic fiber is not particularly limited, and examples thereof include inorganic fibers such as ceramic fibers, mineral fibers such as rock wool, and carbon fibers; and organic fibers such as aramid fibers, rayon fibers, polyimide fibers, and cellulose fibers. These fibers can be used alone or in combination in any ratio. Of these, cellulose fibers are preferably used from the viewpoints of reducing the weight of the fiber sheet and reducing the environmental impact.

[0035] The cellulose fibers are not particularly limited, and any of the following can be used: plant-derived cellulose fibers, animal-derived cellulose fibers such as those from acetic acid bacteria, and regenerated fibers artificially produced by dissolving natural cellulose from trees or wood pulp in a solvent to produce thin, long, continuous fibers. From the viewpoint of achieving excellent dispersibility of the cellulose fibers, cellulose fibers obtained by pulp pulp pulverization (defibration) are preferably used. These cellulose fibers can be used alone or in combination in any ratio.

[0036] The pulp may be either wood pulp or non-wood pulp in terms of raw materials, and either mechanical pulp or chemical pulp in terms of production method.

[0037] Examples of wood pulp include MP, CP, GP, RGP, CGP, SP, AP, KP, SCP, etc., made from conifers such as fir and pine, or broad-leaved trees such as eucalyptus and poplar, and these may be unbleached or bleached pulp.

[0038] Examples of non-wood pulp include natural fibers other than wood, such as cotton, straw, bamboo, esparto, bagasse, linter, kenaf, Manila hemp, flax, hemp, jute, and gampi, as well as recycled paper pulp made from recycled paper and scraps.

[0039] The average fiber length of the non-thermoplastic fibers is preferably 1.5 to 3.5 mm, more preferably 2 to 2.5 mm. When the average fiber length of the non-thermoplastic fibers is within this range, a fiber sheet with excellent sheet strength can be obtained. The average fiber length of the non-thermoplastic fibers can be measured by measuring the fiber length of any 100 fibers in the raw non-thermoplastic fibers using an optical microscope and calculating the number average of the obtained values. Note that the average fiber length of the non-thermoplastic fibers in a fiber sheet or non-thermoplastic fibers removed from the fiber sheet can also be measured in the same manner as described above.

[0040] The average fiber diameter of the non-thermoplastic fibers is preferably 20 to 35 μm. When the average fiber diameter of the non-thermoplastic fibers is in this range, bleeding can be prevented when the rubber penetrates the fiber sheet during thermocompression bonding of the fiber sheet to a rubber member, and a fiber sheet with excellent sheet strength can be obtained. The average fiber diameter of the non-thermoplastic fibers can be measured by measuring the fiber diameter of any 100 fibers in the raw non-thermoplastic fibers using an optical microscope and calculating the number average of the obtained values. Note that the average fiber length of the non-thermoplastic fibers in the fiber sheet or the non-thermoplastic fibers extracted from the fiber sheet can also be measured in the same manner as described above.

[0041] <<Other ingredients>> The fiber sheet may contain other components as needed. The other components are not particularly limited as long as they are known as components contained in fiber sheets, and examples thereof include thermoplastic resin particles, dyes, drainage improvers, paper strength agents, thickeners, dispersants, antifoaming agents, fillers, etc. These can be used alone or in combination in any ratio. These components may be present between the fibers of the thermoplastic fiber sheet, on the surface or inside of the thermoplastic resin fibers, or on the surface or inside of the cellulosic fibers.

[0042] <Thermoplastic resin particles> The fiber sheet may contain thermoplastic resin particles. When thermoplastic resin particles are blended, the blending amount of the thermoplastic resin particles is preferably 0.1 to 70 mass %, more preferably 1 to 60 mass %, and even more preferably 5 to 55 mass %, based on the total mass of the fiber sheet. The thermoplastic resin particles are used for the purpose of improving the interlayer strength of the fiber sheet.

[0043] The material of the thermoplastic resin particles is not particularly limited, but preferred examples include polyesters such as PET, PBT, and copolymer polyester (Co-PES); polyolefins such as polyethylene, polypropylene, and polyethylene-polypropylene copolymer; polylactic acid (PLA); polyglycolic acid (PGA); polyhydroxybutyrate (PHB); polybutylene succinate (PBS); polybutylene succinate adipate (PBSA); polycaprolactone (PCL); polyvinyl alcohol (PVA); polyamide; polyurethane-polylactic acid; polyglycol; etc. These may be used alone or in combination in any ratio.

[0044] The average particle size of the thermoplastic resin particles is not particularly limited, but is preferably 10 to 200 μm, more preferably 20 to 100 μm, even more preferably 30 to 80 μm, and particularly preferably 40 to 70 μm. When the average particle size of the thermoplastic resin particles is within this range, a fiber sheet with superior interlayer strength can be obtained. The average particle size of the thermoplastic resin particles is the volume-based cumulative 50% diameter (D50) of the particles, which can be determined by a particle counter using a laser diffraction scattering method.

[0045] <<Fiber sheet manufacturing method>> The fiber sheet can be produced by a known papermaking method, but here, a wet papermaking method will be described. Non-thermoplastic fibers, thermoplastic resin fibers, and optionally other components are dispersed in water to prepare a raw material slurry, which is then made into paper using a known papermaking machine (papermaking / pressing process). Specifically, papermaking is performed using a cylinder papermaking machine, tilted papermaking machine, Fourdrinier papermaking machine, or short wire papermaking machine, either alone or in combination. A wet sheet (fiber sheet before drying) is obtained by wet papermaking.

[0046] When using cellulose fibers as the non-thermoplastic fibers, it is preferable to beat the cellulose fibers in advance. Beating can be carried out appropriately using a beating machine such as a single disc refiner (SDR), a double disc refiner (DDR), or a beater.

[0047] The obtained wet sheet is dehydrated and dried at a drying temperature of 100 to 140° C. to obtain a fiber sheet (drying step). Specifically, this can be carried out using a known dryer such as a Yankee dryer, a cylinder dryer, an air dryer, or an infrared dryer.

[0048] Here, by adjusting the press pressure in the dewatering and drying steps in the papermaking process and the roll surface temperature in the drying step, it is possible to obtain a desired porosity of the fiber sheet.

[0049] <<Applications of fiber sheets>> The fiber sheet can be used as a composite member of a rubber member and a fiber sheet by bonding a rubber member to one main surface of the fiber sheet by thermocompression bonding. The thermocompression bonding method involves loading a fiber sheet into a rubber mold, pouring a rubber material into the mold, and then applying heat of 160-170°C and a load of about 100 kgf to mold the rubber material while allowing it to penetrate into the voids in the sheet. After holding for a certain period of time, the sheet is cooled at room temperature to obtain a composite part of the fiber sheet and rubber material (thermocompression bonding process).

[0050] The rubber material is not particularly limited, and examples thereof include natural rubber (NR), styrene butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). These materials can be used alone or in combination in any ratio. These materials are highly durable and therefore suitable for the anti-slip member described below. is.

[0051] The composite member of a fiber sheet and a rubber member can be used, for example, as an anti-slip member, and is particularly preferably used as an anti-slip member for the outsole (bottom) of a shoe. Since the outsole of a shoe requires adhesive strength and durability, a composite member using the fiber sheet of the present disclosure is preferably used. [Example]

[0052] Specific examples are given below, but the present invention is not limited to these. <<Manufacturing of fiber sheets and composite materials>> <Raw materials> The fiber sheets and composite members of each example and comparative example were manufactured using the following raw materials. The formulations of each example and comparative example (each formulation is shown in mass % based on the total mass of the fiber sheet) are shown in Tables 1 and 2. (thermoplastic resin fiber) Thermoplastic resin fiber 1: core-sheath fiber (core: PET, sheath: copolymerized PET, melting temperature: 130°C, glass transition temperature: 73.3°C, fineness: 2.2 dtex, average fiber length: 5 mm) Thermoplastic resin fiber 2: core-sheath fiber (core: PET, sheath: copolymer PET, melting temperature: 150°C, glass transition temperature: 72.6°C, fineness: 2.2 dtex, average fiber length: 5 mm) Thermoplastic resin fiber 3: Main fiber of polyester (melting temperature 230°C, glass transition temperature: 77.7°C, fineness 1.2 dtex, average fiber length 5 mm) Thermoplastic resin fiber 4: Main fiber of polyester (melting temperature 260°C, glass transition temperature: 76.5°C, fineness 1.2 dtex, average fiber length 5 mm) Thermoplastic resin fiber 5: core-sheath fiber (core: polylactic acid, sheath: polybutylene succinate, melting temperature: 115°C, glass transition temperature: -30°C, fineness: 2.4 dtex, average fiber length: 5 mm) (Non-thermoplastic fiber) Non-thermoplastic fiber: Cellulose fiber (softwood pulp, N wood, average fiber length 2.3 mm, average fiber diameter 27.6 μm) (thermoplastic resin particles) Thermoplastic resin particles: Powder resin G-190P (Tokyo Ink Mfg. Co., Ltd., copolymer polyester type, melting point 120°C, average particle size: 55 μm) (Rubber material) Rubber 1: Styrene butadiene rubber (SBR) Rubber 2: Acrylonitrile butadiene rubber (NBR)

[0053] <Manufacturing> According to the formulations in Tables 1 and 2, fiber sheets of each Example and Comparative Example were produced, and further, composite members of each Example and Comparative Example's fiber sheet and a rubber member were produced (referred to as composite members of each Example and Comparative Example). Specifically, each raw material for the fiber sheet shown in Tables 1 and 2 was dispersed in water to prepare a raw material slurry, and the obtained raw material slurry was made into paper using a cylinder paper machine to obtain a wet sheet. The resulting wet sheet was then dehydrated and dried using a Yankee dryer at a drying temperature of 140°C to obtain a fiber sheet of each Example and Comparative Example. The settings of the touch roll pressure and calender roll pressure applied to the Yankee dryer in the production of the fiber sheet of each Example and Comparative Example are shown in Tables 1 and 2.

[0054] The obtained fiber sheets of each Example and Comparative Example were cut into a shape of 200 mm in length x 100 mm in width, and the mass was measured to determine the basis weight (g / m), which is the mass per area (200 mm in length x 100 mm in width) of the fiber sheet. 2 ) was calculated. The porosity of the fibrous sheet was calculated based on the above-mentioned formula 1. Furthermore, the arithmetic mean surface roughness was measured using a surface roughness measuring device (OLS3000 manufactured by Olympus Corporation). The results of the basis weight, thickness, porosity, and arithmetic mean surface roughness of the fibrous sheets of each example and comparative example are shown in Tables 1 and 2.

[0055] The obtained fiber sheets of each Example and Comparative Example were loaded into a rubber mold, and the rubber materials of each Example and Comparative Example listed in Tables 1 and 2 were poured into the mold. Then, while heating to 160-170°C, a load of approximately 100 kgf was applied, allowing the rubber materials to penetrate into the voids in the fiber sheet and mold it. After holding for a certain period of time, the mold was cooled at room temperature to obtain a composite member of the fiber sheet and rubber member of each Example and Comparative Example. The composite member of the fiber sheet and rubber member was molded into a rectangular shape measuring 200 mm in length, 100 mm in width, and 3.15 mm in thickness (fiber sheet thickness: 150 μm, rubber member thickness: 3 mm) using a mold.

[0056] <<Evaluation>> <Peel strength evaluation> The resulting composite members of the fiber sheet and rubber member in each example and comparative example were subjected to peel strength measurement using an Instron material testing machine in accordance with "5.3 Peel Strength" in JIS X6305-1:2010. The measurement was performed at a peel angle of 90° and a tensile speed (crosshead speed) of 200 mm / min. The measurement results were evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) A: The peel strength measurement result is 20N / 15mm or more. B: The peel strength measurement result is 10N / 15mm or more and less than 20N / 15mm C: The peel strength measurement result is 2N / 15mm or more and less than 10N / 15mm D: The peel strength measurement result is less than 2N / 15mm

[0057] <Evaluation of the outermost surface appearance after thermocompression bonding> The outermost surface appearance of the composite members of the fiber sheet and rubber member in each Example and Comparative Example after thermocompression bonding was observed with the naked eye. Evaluation was based on the following criteria. The results are shown in Tables 1 and 2. A: No bleeding is visible on the top surface of the composite material after thermocompression bonding. B: Slight bleeding can be seen on the outermost surface of the composite material after thermocompression bonding, but it is not enough to impair the appearance. C: Blurring can be seen on the outermost surface of the composite material after thermocompression bonding, but this is acceptable depending on the application. D: Clear bleeding is observed on the outermost surface of the composite material after thermocompression bonding, significantly impairing the appearance.

[0058] <Overall rating> A: The peel strength evaluation result and the outermost surface appearance evaluation result after thermocompression bonding are both A. B: Either the peel strength evaluation result or the outermost surface appearance evaluation result after thermocompression bonding is A and the other is B, or both evaluation results are B. C: Either the peel strength evaluation result or the outermost surface appearance evaluation result after thermocompression bonding is A or B, and the other is C, or both evaluation results are C. D: The peel strength evaluation result and the outermost surface appearance evaluation result after thermocompression bonding are either A, B, or C for one and D for the other, or both are D.

[0059] [Table 1]

[0060] [Table 2]

Claims

1. The fabric comprises thermoplastic resin fibers and non-thermoplastic fibers, The thermoplastic resin fiber is 30 to 80% by mass based on the total mass, The non-thermoplastic fibers are 20 to 70% by mass based on the total mass, a mass ratio of the thermoplastic resin fibers to the non-thermoplastic fibers (the thermoplastic resin fibers / the non-thermoplastic fibers) is 3 / 7 to 8 / 2; A fiber sheet bonded to a rubber component.

2. 2. The fiber sheet according to claim 1, having a porosity of 20 to 70%.

3. The melting temperature of the thermoplastic resin fiber is 110 to 250°C, 3. The fiber sheet according to claim 1, wherein the thermoplastic resin fibers have a glass transition temperature of 80°C or lower.

4. 3. The fiber sheet according to claim 1 or 2, wherein the thermoplastic resin fibers contain at least one of polyester, polyolefin, polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyamide, polyurethane polylactic acid, and polyglycol.

5. 3. The fiber sheet according to claim 1, which is produced by a wet papermaking method.

6. 3. The fiber sheet according to claim 1, wherein the arithmetic mean surface roughness (Ra) of the main surface of the fiber sheet on the side to be bonded to the rubber member is 5 to 20 μm.

7. 3. The fiber sheet according to claim 1, wherein the rubber member comprises at least one of natural rubber (NR), styrene butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR).

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