Shock-absorbing material

Abstract

This invention provides a cushioning material that can be easily installed while suppressing whitening, by having a core material made of tarpaulin and foam in which the content of specific inorganic particles is 5.0 parts by mass or less. [Solution] The cushioning material comprises a core made of foam and tarpaulin in that order, wherein the tarpaulin contains 5.0 parts by mass or less of inorganic particles with an average particle diameter of 1.00 μm or more, calculated from the specific surface area measurement results of the air permeability method in accordance with JIS M-8511, per 100 parts by mass of resin component.

Description

Background Art

[0001] From the perspective of ensuring the safety of athletes, foaming materials have been applied to fences and the like. As methods thereof, there have been known a method of installing a rubber fence (Patent Documents 1 and 2) in which a rubber composition layer is formed on a foam, and a method of forming a surface layer by spraying a high-viscosity mixture in which a main agent and a curing agent are mixed by spraying means in a low-pressure state after attaching a buffer material layer made of a foam on the surface of a concrete wall (Patent Document 3).

[0002] Also, it has been known to use tarpaulin as a material for the roofs and eaves of large facilities such as stadiums and for sunshade tents of stores (Patent Document 4).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a buffer material having a core material made of a foam and a tarpaulin in this order, wherein the tarpaulin has a content of inorganic particles having a specific average particle diameter within a specific range, and can be easily constructed while suppressing whitening.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, the present inventor provides the following [1]. [1] A cushioning material comprising a foam core and tarpaulin in that order, wherein the tarpaulin contains 5.0 parts by mass or less of inorganic particles with an average particle diameter of 1.00 μm or more, calculated from the specific surface area measurement results of the air permeability method in accordance with JIS M-8511, per 100 parts by mass of resin components. [Effects of the Invention]

[0006] According to the present invention, a cushioning material can be provided that has a core material made of foam and tarpaulin in that order, and the tarpaulin contains inorganic particles with a specific average particle size within a specific range, thereby suppressing whitening and allowing for easy installation. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of an example of the cushioning material of this embodiment. [Figure 2] This is a microscopic image of the whitened area of ​​the tarpaulin in Comparative Example 1. [Figure 3] This is a schematic diagram of the tarpaulin used in this embodiment. [Figure 4] This is a schematic diagram showing an example of installing buffer material on a structure (plane). [Figure 5] This is a schematic diagram showing an example of installing buffer material on a structure (cylindrical column). [Modes for carrying out the invention]

[0008] Patent Document 1 describes a rubber fence having a foam cushioning layer, a reinforcing layer, and a dynamically vulcanized rubber composition layer in that order, and Patent Document 2 describes a wall cushioning material in which a sheet made of polyester is attached to the surface of a polyethylene foam, and a rubber sheet is attached to this sheet. In both of these, the rubber material is placed on the outermost surface of the foam. When the rubber material is placed on the outermost surface, it is difficult to apply a design to the surface due to poor printing properties. In addition, the rubber material is inferior in terms of strength, so problems such as tearing occur when subjected to strong impact, and especially when used outdoors, chalking occurs, resulting in deterioration in appearance and durability. Furthermore, sulfur derivatives may be washed away by rainwater.

[0009] Patent Document 3 describes an impact-absorbing fence in which a urethane elastomer is sprayed onto the surface of a foam cushioning material layer to form a urethane layer. However, because this method involves spraying urethane elastomer, it cannot be installed in enclosed spaces such as indoors. Furthermore, even outdoors, it becomes extremely difficult to ensure that the entire fence, especially if it covers a large area, has a certain thickness or higher. In addition, since the surface of the urethane layer is formed after installation, it is difficult to apply any design elements to the surface, and it is not possible to obtain a highly smooth surface in the first place.

[0010] Patent Document 4 describes tarpaulin used for roofs and eaves of large facilities such as sports stadiums. Tarpaulin is suitable for outdoor use because of its excellent durability, waterproofing, and stain resistance, and it also has excellent printability, allowing designs to be applied to its surface by printing. On the other hand, if scratches occur due to strong forces such as collisions with athletes or contact with jigs during construction, the scratches turn white, and the white linear scratches become noticeable. Figure 2 is a micrograph observing the state of whitening (hereinafter, "whitening" refers to the condition in which scratches remain as white lines, as shown in Figure 2). The state of whitening can be confirmed, for example, by adding a black coloring agent to the resin layer of tarpaulin to make it black as in the initial state 20, and then observing the scratches caused by rubbing it multiple times with a 6H pencil. In the micrograph of Figure 2, the left half, the initial state 20, is an area that has not been rubbed, and the white linear areas on the right half show the state 21 where scratches have been made with a 6H pencil and whitened. Even if scratches occur, if they do not whiten, the scratches are not noticeable because they are the original color.

[0011] The cushioning material of this disclosure has been found to protect against impacts during collisions with athletes, etc., and to suppress whitening, by having a core material made of foam and a tarpaulin with an adjusted content of inorganic particles having a specific average particle size. Furthermore, the cushioning material has been found to have excellent workability. In addition, when the tarpaulin is on the outermost surface of the cushioning material, it is preferable for outdoor use because it has excellent durability, waterproofing and stain resistance, and it is also preferable because it has excellent printability, allowing designs to be applied to its surface by printing.

[0012] The following describes the cushioning materials related to this disclosure, but is not limited to the following examples.

[0013] In the present disclosure, the thickness direction 100 means the thickness direction of the tarpaulin as shown in FIG. 3, and the width direction 110 is a direction different from the thickness direction and means a direction perpendicular to the longitudinal direction 120 of the tarpaulin. For example, when the tarpaulin is manufactured by the calendar molding method, the longitudinal direction 120 corresponds to the flow direction (MD: machine direction), and the width direction 110 corresponds to the TD (transverse direction) perpendicular to the MD.

[0014] Hereinafter, embodiments of the present disclosure (hereinafter sometimes referred to as "the present embodiments") will be described. In the present disclosure, the numerical values related to "above", "below", "~", etc. in the description of numerical ranges are numerical values that can be arbitrarily combined.

[0015] Also, the defined provisions that are considered preferable can be arbitrarily adopted. That is, one of the defined provisions that are considered preferable can be adopted in combination with one or more other defined provisions that are considered preferable. It can be said that combinations of preferable ones are more preferable.

[0016] 〔Buffer material〕 The buffer material of the present embodiment has a core material made of a foam and a tarpaulin in this order, and the tarpaulin has a content of inorganic particles having an average particle diameter of 1.00 μm or more calculated from the measurement result of the specific surface area by the air permeability method according to JIS M-8511 of 5.0 parts by mass or less with respect to 100 parts by mass of the resin component. It is required to be a buffer material.

[0017] The buffer material is installed to mitigate the impact when athletes, pedestrians, etc. collide with structures or the like. It is also preferable to install it to mitigate the impact against collisions by vehicles, forklifts, etc. Examples of the structures include, for example, baseball fields, soccer fields, track and field stadiums, other stadiums, and the walls of indoor gymnasiums, the posts of soccer goals and basketball hoops, the posts of nets for tennis, volleyball, etc., and columns installed at locations where pedestrians and vehicles pass through, such as the platforms and corridors of stations. Particularly when the tarpolin is the outermost surface of the buffer material, it is preferably installed outdoors due to the durability, waterproofness, and stain resistance of the tarpolin, and it is also preferable in that it can protect the surface of the structure from the attachment of dirt and the like.

[0018] Also, it is preferable to construct the buffer material with respect to the existing structures. For example, by installing it on an existing baseball field, it is preferable because even an old fence can conceal its dirt and the like and improve the safety of athletes. Also, for a wide planar structure like the fence of a baseball field, not only can the buffer material be arranged and installed flatly (Figure 4), but it is also possible to wrap a columnar structure like the post of a basketball hoop (Figure 5) with the flexible buffer material, which is therefore preferable.

[0019] The buffer material 1 shown in (a) and (b) of Figure 1 is a schematic diagram showing the cross-section of the buffer material. (a) shows a form in which three sides of the core material 11 made of a foam to be described later are wrapped with the tarpolin 10 to be described later, while (b) shows a form in which the tarpolin 10 is arranged only on one side of the core material 11 made of a foam. The form may be appropriately selected according to the shape of the structure on which the buffer material 1 is installed and the ease of construction of the installation of the buffer material 1.

[0020] The size of the buffer material may be appropriately determined according to its installation location and the like. The thickness 130 of the buffer material in Figure 1 only needs to be thick enough to absorb the impact, but it is preferably 3 cm or more and 1 m or less, and more preferably 5 cm or more and 50 cm or less.

[0021] The cushioning material of this embodiment may have a core made of foam and tarpaulin, but may also further have an adhesive layer, a reinforcing layer, etc., which are commonly used in the art.

[0022] The core material and tarpaulin will be explained below.

[0023] <Core material> The core material must be a foam. The foam is not particularly limited as long as it is a material (foamed resin layer) that is excellent at absorbing impact, but it is preferable that it contains at least one of the following: urethane resin (including ether-based or ester-based urethane foam urethane, etc.), ethylene resin, propylene resin, vinyl chloride resin, polystyrene resin, melamine resin, and epoxy resin, and may be a single material or a copolymer thereof. As the styrene resin, polymers (polyethylene-styrene copolymer, polypropylene-styrene copolymer) whose main constituent units are styrene, methylstyrene, dimethylstyrene, etc. are preferred. The foamed resin layer may be a single layer or consist of multiple layers of different materials.

[0024] These materials are preferably flexible in order to improve the ease of installation.

[0025] The thickness of the core material should be sufficient to absorb impact, but it is preferably 3 cm to 1 m, and more preferably 5 cm to 50 m.

[0026] <Tarpaulin> The tarpaulin must contain 5.0 parts by mass or less of inorganic particles with an average particle diameter of 1.00 μm or more, calculated from the specific surface area measurement results of the air permeability method in accordance with JIS M-8511, per 100 parts by mass of resin components.

[0027] The tarpaulin has a structure in which a resin layer is provided on at least one side of a layer containing synthetic fibers, and the layer containing synthetic fibers may be a woven or knitted fabric of synthetic fibers. The resin layer may be a separate layer from the layer containing synthetic fibers, or the resin layer may be partially or completely impregnated.

[0028] The tarpaulin is preferably manufactured by coating at least one side of a base fabric such as a woven or nonwoven polyester fiber fabric with a resin layer, and it is preferable that the base fabric of synthetic fibers is sandwiched between resin layers on both sides.

[0029] The base fabric is not particularly limited in terms of its structure or weave, as long as it is a woven or knitted fabric that has been conventionally used for this purpose. Plain weave and twill weave fabrics are preferred, and plain weave is preferred due to its strength, ease of manufacture, and cost advantages when used as tarpaulin. The thickness of the fibers used and the mesh opening can be adjusted as appropriate according to the required characteristics.

[0030] The synthetic fibers are preferably polyester resins (such as PET resin), polyamide resins, polyolefin resins, polyacrylonitrile resins, etc., and may be monofilaments or multifilaments, with polyester multifilament yarn being more preferred.

[0031] The resin component in the resin layer more preferably contains at least one of polyethylene resins, polypropylene resins, and polyvinyl chloride resins, and more preferably is a thermoplastic synthetic resin such as a polyvinyl chloride resin or an ethylene-vinyl acetate copolymer, and even more preferably is a polyvinyl chloride resin.

[0032] The vinyl chloride resin may be a polymer of polyvinyl chloride monomer alone, or a copolymer of polyvinyl chloride monomer and a monomer copolymerizable with polyvinyl chloride monomer, such as vinyl acetate monomer or acrylonitrile monomer. The polymerization method for the polyvinyl chloride resin is not particularly limited, and resins produced by commonly used polymerization methods such as suspension polymerization or emulsion polymerization can be used.

[0033] The degree of polymerization of the vinyl chloride resin can be appropriately changed depending on the required properties, but it is preferably 1100 to 3000, and more preferably 1200 to 2500, from the perspective of balancing mechanical properties and flexibility.

[0034] The thickness of the tarpaulin (thickness direction 100 in Figure 3) can be appropriately selected depending on the required strength, but is preferably 0.1 mm or more and 10.0 mm or less, more preferably 0.2 mm or more and 5.0 mm or less, even more preferably 0.3 mm or more and 1.0 mm or less, and even more preferably 0.4 mm or more and 0.8 mm or less.

[0035] (Inorganic particles) The inorganic particle content must be such that the amount of inorganic particles with an average particle diameter of 1.00 μm or more is 5.0 parts by mass or less per 100 parts by mass of resin component. These inorganic particles are fillers used primarily to reduce the resin content, and some flame retardants also fall into this category. If the amount of inorganic particles with an average particle diameter of 1.00 μm or more exceeds 5 parts by mass, the aforementioned whitening will occur significantly. As the amount decreases, the degree of whitening is suppressed, so it is more preferable that the content be 3.0 parts by mass or less, even more preferable that be 2.0 parts by mass or less, even more preferable that be 1.0 part by mass or less, and most preferably that be substantially absent. "Substantially absent" means that impurities and other unintentionally included substances are excluded and the substance is not present.

[0036] Examples of the inorganic particles include: carbonates, sulfates, silicates, phosphates, or borates of metals (calcium, magnesium, aluminum, titanium, iron, zinc, etc.); oxides of metals (calcium, magnesium, aluminum, titanium, iron, zinc, etc.); hydrates of the above salts or oxides, etc. These may be synthesized or derived from natural minerals.

[0037] More specifically, calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica, carbon black, zeolite, molybdenum, diatomaceous earth, and bentonite are preferred; calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, talc, carbon black, zeolite, molybdenum, diatomaceous earth, and bentonite are more preferred; calcium carbonate, silica, alumina, and talc are even more preferred; and calcium carbonate is even more preferred.

[0038] The aforementioned talc is classified as a clay mineral and a silicate mineral (Mg3Si4O 10 It is a type of (OH)2). It is classified as a phyllosilicate mineral, a mineral composed of magnesium hydroxide and silicate, and rocks in which this mineral is the main component are also included. It is also called talc, steatite, soapstone, French chalk, and lava.

[0039] (Additives) The resin component of the resin layer may further contain additives in addition to the inorganic particles. Preferred additives include flame retardants, plasticizers, colorants, antistatic agents, antioxidants, ultraviolet absorbers, lubricants, liquid stabilizers, and light stabilizers commonly used in the art. One or more of these additives may be included. It is particularly preferable to include a flame retardant when used indoors.

[0040] ((Flame retardant)) The flame retardant can be any flame retardant commonly used in the field, but inorganic flame retardants are particularly preferred, antimony oxide is more preferred, and antimony trioxide is even more preferred. Inorganic flame retardants are partially in particulate form, but even when using particulate inorganic flame retardants, the average particle size is preferably less than 1.00 μm, more preferably 0.80 μm or less, even more preferably 0.70 μm or less, and even more preferably 0.65 μm or less. Antimony trioxide is preferred because it is readily available in particles less than 1.00 μm, more preferably antimony trioxide with a particle size of 0.80 μm or less, even more preferably antimony trioxide with a particle size of 0.70 μm or less, and even more preferably antimony trioxide with a particle size of 0.65 μm or less.

[0041] The flame retardant is preferably present in an amount of 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, even more preferably 3 to 13 parts by mass, and even more preferably 4 to 10 parts by mass, per 100 parts by mass of the resin component, in order to exhibit flame retardant performance and suppress whitening.

[0042] ((plasticizer)) When a flexible polyvinyl chloride resin is included as a resin component, a general-purpose plasticizer for the flexible polyvinyl chloride resin can be used. For example, phthalate ester plasticizers such as di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and diundecyl phthalate (DUP) can be used; trimellitic acid ester plasticizers such as trioctyl trimellitate (TOTM); fatty acid ester plasticizers such as dioctyl adipate (DOA), dioctyl sebacate (DOS), and dioctyl azelate (DOZ); phosphate ester plasticizers such as cresyl diphenyl phosphate (CDP) and tricresyl phosphate (TCP); epoxy plasticizers such as epoxidized vegetable oil (e.g., epoxidized soybean oil); polyester plasticizers can be used. Among these, di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), dioctyl adipate (DOA), and cresyl diphenyl phosphate (CDP) are preferred, with diisononyl phthalate (DINP) and dioctyl adipate (DOA) being more preferred. These plasticizers may be used individually, but it is also preferable to use two or more plasticizers in combination. When used in combination, the combination of DOP and DINP, and the combination of DOP and CDP are preferred. Furthermore, it is also preferable to combine them with epoxidized soybean oil.

[0043] The plasticizer is preferably in an amount of 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, even more preferably 40 to 65 parts by mass, and even more preferably 50 to 60 parts by mass, per 100 parts by mass of the resin component, in order to improve processability, maintain tensile strength, and suppress whitening.

[0044] ((coloring agent)) It is preferable to include a coloring agent in the resin layer so that the cushioning material can be given the desired color tone. In particular, when used for fences in baseball fields or posts for volleyball nets, it is preferable to use dark blue or dark green so that the color difference with the ball is large and the ball is easier to see. When dark blue or dark green is used, the aforementioned whitening becomes more noticeable, so it is important to suppress whitening.

[0045] The aforementioned colorant is one that is commonly used in the present art and is not particularly limited as long as the buffer material exhibits the desired color tone. It may be a dye or pigment, an inorganic compound or an organic compound, a natural colorant or a synthetic colorant, as long as it absorbs visible light. In particular, when used outdoors and weather resistance is required, it is preferably a synthetic pigment, and to improve color development, it is preferably an organic pigment. The aforementioned colorant preferably contains an inorganic pigment or an organic pigment, and is preferably an inorganic pigment or an organic pigment. More specifically, inorganic pigments such as titanium white (titanium dioxide), zinc oxide, iron oxide, vermilion, ultramarine, cobalt blue, titanium yellow, lead yellow, and carbon black; organic pigments (including dyes) such as isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, induthlene blue RS, and aniline black are preferred.

[0046] ((UV absorber, antioxidant, lubricant, liquid stabilizer)) Preferred UV absorbers include benzotriazole compounds, triazine compounds, benzophenone compounds, and cyanoacrylate compounds, with benzotriazole compounds or triazine compounds being more preferred, and benzotriazole compounds being even more preferred, as they exhibit high UV absorption effects over long periods. These UV absorbers may be used alone, but it is also preferable to use them in combination with two or more plasticizers.

[0047] Examples of the antioxidants include phenolic antioxidants such as monophenolic antioxidants, diphenolic antioxidants, and hindered phenolic antioxidants; phosphorus-based antioxidants such as triphenylphosphite, diisopropylmonophenylphosphite, and monobutyldiphenylphosphite; amine-based antioxidants such as diphenylamine antioxidants and naphthylamine antioxidants; and sulfur-based antioxidants such as phenothiazine, dioctadecyl sulfide, dilauryl-3,3'-thiodipropionate, and 2-mercaptobenzimidazole. As the phenolic antioxidant, a commonly used phenolic antioxidant in this field, such as Irganox 1010 (BASF Japan Ltd.), is preferred, and as the phosphorus-based antioxidant, a commonly used phosphorus-based antioxidant in this field, such as Sumilizer GP (Sumitomo Chemical Co., Ltd.) or Irgafos 168 (BASF Japan Ltd.), is preferred.

[0048] Magnesium stearate is preferred as a lubricant.

[0049] Liquid stabilizers are added, particularly when vinyl chloride resins are used as the resin component, to prevent the detachment of hydrogen chloride from the vinyl chloride resin during processing and to stop the decomposition chain reaction. Barium-zinc stabilizers, calcium-zinc stabilizers, tin stabilizers, and lead stabilizers are preferred, with barium-zinc stabilizers and calcium-zinc stabilizers being more preferred.

[0050] These additives are preferably present in amounts of 10 to 100 parts by mass, more preferably 30 to 80 parts by mass, even more preferably 50 to 70 parts by mass, and even more preferably 60 to 75 parts by mass, per 100 parts by mass of the resin component, in order to suppress whitening and facilitate application.

[0051] <<Adhesive>> The core material 11 and the tarpaulin 10 may be bonded together with an adhesive. Examples of such adhesives include adhesives mainly composed of chloroprene rubber, solvent-based adhesives such as butyl rubber, and emulsion-based adhesives mainly composed of acrylic rubber.

[0052] [Method of manufacturing cushioning material] The cushioning material of this embodiment can be manufactured, for example, by the following method.

[0053] The aforementioned tarpaulin was prepared by blending a resin component, inorganic particles with an average particle size of 1.00 μm or more, and additives as needed, and obtaining a sheet-like resin layer by calendering or melt extrusion molding.

[0054] Tarpaulin can be obtained by placing a plain weave fabric made of synthetic fiber multifilaments between two of the aforementioned sheet-like resin layers, and then laminating and integrating them using a heat lamination method.

[0055] The cushioning material 1 can be manufactured by covering a core material made of foam with the obtained tarpaulin.

[0056] The cushioning material in this embodiment is preferably one of the following [1] to [7]. [1] It has a core made of foam and tarpaulin in that order, The tarpaulin is a cushioning material in which, per 100 parts by mass of resin component, the content of inorganic particles with an average particle diameter of 1.00 μm or more, calculated from the specific surface area measurement results of the air permeability method in accordance with JIS M-8511, is 5.0 parts by mass or less. [2] The cushioning material according to [1], wherein the foam contains at least one of urethane resin, ethylene resin, propylene resin, vinyl chloride resin, styrene resin, melamine resin, and epoxy resin. [3] The cushioning material according to [1] or [2], wherein the tarpaulin contains at least one of polyethylene resin, polypropylene resin, and polyvinyl chloride resin as the resin component. [4] The cushioning material according to any one of [1] to [3], wherein the tarpaulin further contains a flame retardant. [5] The cushioning material according to any one of [1] to [4], wherein the tarpaulin further contains one or more selected from plasticizers, colorants, antistatic agents, antioxidants, ultraviolet absorbers, lubricants, liquid stabilizers, and light stabilizers. [6] The cushioning material according to any one of [1] to [5], wherein the tarpaulin is the outermost surface. [7] Cushioning material for outdoor use as described in any one of [1] to [6]. [Examples]

[0057] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited in any way to the following examples. 1. Whitening evaluation The tarpaulins obtained in the examples and comparative examples described below were cut into 10cm x 10cm pieces and used as evaluation samples.

[0058] The obtained evaluation samples were pressed at a speed of 1 mm / s for a length of 3 cm or more using a pencil hardness test machine (JIS K5600-5-4) equipped with a 6H pencil. This procedure was repeated three times, changing the evaluation sample each time.

[0059] The damaged areas of the evaluation samples after the aforementioned procedure were observed visually and under 20x magnification using a digital microscope (Keyence VHX-X1), and evaluated on the following three-level scale. Grades A and B were considered pass. The results are shown in Tables 1 to 5.

[0060] Grade A (indicated as A in the table): Scratches are present, but the color is the same as the rest of the area.

[0061] Grade B (indicated as B in the table): The damaged area appears slightly white when observed with a digital microscope, but no whitening is visible to the naked eye.

[0062] Grade C (indicated as C in the table): Whitening can be confirmed both visually and with a digital microscope.

[0063] 2.Materials used (Resin component for forming the resin layer of tarpaulin) The components shown in Table 1 were added to a vinyl chloride resin (P-1100), and the mixture was kneaded at 90°C using a resin mixing mixer to obtain the resin used for forming the resin layer in the examples and comparative examples.

[0064] [Table 1]

[0065] [Table 2]

[0066] [Table 3]

[0067] [Table 4]

[0068] [Table 5]

[0069] In the table, the content (parts by mass) of each component per 100 parts by mass of vinyl chloride resin is listed, and "-" means that the component is not present. Plasticizer 1: DINP Plasticizer 2: DOA Plasticizer 3: Epoxy soybean oil Liquid stabilizer: Barium zinc-based stabilizer Inorganic particle 1: Calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., Whiteon SB Aka, average particle size: 1.80 μm) Inorganic particles 2: Calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., Whiteon SSB Blue, average particle size: 1.50 μm) Inorganic particles 3: Aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., BF013, average particle size: 1.00 μm) Inorganic particle 4: Talc (manufactured by Nippon Talc Co., Ltd., MS-W, average particle size: 13.00 μm) Flame retardant: Antimony trioxide (manufactured by Nippon Seikou Co., Ltd., PATOX-MK, average particle size: 0.50 μm) UV absorbers: Benzotriazole-based UV absorbers Coloring agent: Black pigment (carbon black)

[0070] (Tarpaulin fiber woven fabric) Polyester multifilament (500D) with a weight of 500g per 9000m was used as the warp and weft threads, and this was woven in a plain weave to create a textile fabric.

[0071] (Examples 1-1 to 4-2 and Comparative Examples 1-1 to 5-4) Using the aforementioned resin component for forming the tarpaulin resin layer, a black sheet-like resin layer with a thickness of 0.3 mm was obtained by calendering.

[0072] The aforementioned fiber fabric is sandwiched between the aforementioned resin layers and laminated by a heat lamination method (150°C, 20 kgf / cm²). 2 Each tarpaulin (thickness: 0.50 mm) was obtained by the following method.

[0073] The obtained tarpaulins were used to cover the core material, and a cushioning material was obtained.

[0074] All of the aforementioned cushioning materials were confirmed to absorb impact and also to have excellent workability. Furthermore, the cushioning materials using tarpaulin in each example were confirmed to have excellent performance in terms of whitening.

[0075] In contrast, Comparative Examples 1-1 to 5-4 showed the same effect as the cushioning material in the Examples in terms of shock absorption, but were found to be inferior in terms of whitening. Furthermore, in Comparative Examples 5-1 to 5-4, the amount of flame retardant with an average particle size of less than 1.00 μm was varied to check the whitening situation. Compared with Examples 1-1 and 1-2, it was found that whitening could be suppressed even with flame retardants if the particle size was less than 1.00 μm. [Industrial applicability]

[0076] The cushioning material of this embodiment can be easily installed while suppressing whitening, making it suitable for use on the walls of baseball fields, soccer fields, athletic stadiums, other sports venues and indoor gymnasiums, the posts for soccer goals and basketball hoops, the posts for tennis and volleyball nets, and pillars installed in places where pedestrians and vehicles pass through, such as train station platforms and corridors. [Explanation of Symbols]

[0077] 1 Cushioning material 2 structures 10 Tarpaulin 11. Core material made of foam 20 Initial state 21 Whitened state 100 Thickness direction 110 Width direction 120 Longitudinal direction 130 Thickness of cushioning material

Claims

1. It has a core material made of foam and tarpaulin in that order, The tarpaulin is a cushioning material in which, per 100 parts by mass of resin component, the content of inorganic particles with an average particle diameter of 1.00 μm or more, calculated from the specific surface area measurement results of the air permeability method in accordance with JIS M-8511, is 5.0 parts by mass or less.

2. The cushioning material according to claim 1, wherein the foam contains at least one of urethane resin, ethylene resin, propylene resin, vinyl chloride resin, styrene resin, melamine resin, and epoxy resin.

3. The cushioning material according to claim 1, wherein the tarpaulin contains at least one of polyethylene resin, polypropylene resin, and polyvinyl chloride resin as the resin component.

4. The cushioning material according to claim 1, wherein the tarpaulin further contains a flame retardant.

5. The cushioning material according to claim 1, wherein the tarpaulin further contains one or more selected from plasticizers, colorants, antistatic agents, antioxidants, ultraviolet absorbers, lubricants, liquid stabilizers, and light stabilizers.

6. The cushioning material according to claim 1, wherein the tarpaulin is the outermost surface.

7. A cushioning material according to claim 1, for use outdoors.

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