Composition for foam molding, foam molded article, and member

Abstract

The present invention provides a composition for foam molding, which has excellent foamability and according to which a molded article after foaming (foam molded article) demonstrates excellent strength, thermal expandability during combustion, and shape stability after combustion.　The present invention provides a composition for foam molding, the composition comprising a crosslinkable rubber component, a phosphoric acid-based inorganic compound, a crosslinking agent, and a foaming agent, wherein with respect to 100 parts by mass of the crosslinkable rubber component, the content of the phosphoric acid-based inorganic compound is 10-2000 parts by mass, the content of the crosslinking agent is 0.1-30 parts by mass, the content of the foaming agent is 1-30 parts by mass, and the content of a thermally expandable layered inorganic compound is less than 5 parts by mass.

Description

Composition for foam molding, foam molded body, and member

[0001] The present invention relates to a composition for foam molding, a foam molded body, and a member.

[0002] Synthetic resins are widely used as building materials because of their good moldability and mass productivity of uniform products. On the other hand, synthetic resins are inexpensive when melted or burned and generate gas and smoke. Therefore, from the viewpoint of safety in case of fire, materials with excellent low smoke generation properties and fire resistance are required. In particular, for door and window sashes, not only the flame retardancy of the material but also a material that can prevent the flame from spreading outside (the back side) of the door or window by maintaining its shape even after combustion is required.

[0003] As a material that meets such requirements, Patent Document 1 discloses a rubber composition that can obtain a foam molded body having an excellent balance of thermal expansibility, shape retention, and flame retardancy and a small specific gravity, which contains a thermosetting elastomer, a thermal expander, a solid metal (sub)phosphate, an inorganic filler, and a foaming agent.

[0004] In recent years, thermally expandable refractory materials have also been used for battery members. In battery cells such as lithium-ion batteries, disasters such as ignition and smoke generation may occur at high temperatures. In order to suppress damage when fire breaks out from the battery cell, a thermally expandable refractory material may be used around the battery cell. For example, Patent Document 2 discloses a thermally expandable refractory sheet that contains a matrix resin and thermally expandable graphite, contains 5% by mass or more of the thermally expandable graphite, and specifies the relationship between the thickness of the thermally expandable refractory sheet and the average aspect ratio of the thermally expandable graphite.

[0005] WO2020 / 090696 JP2018-115319

[0006] The thermally expandable graphite described in Patent Document 1 is obtained by treating powders of natural graphite, pyrolysis graphite, etc., with inorganic acids such as sulfuric acid and nitric acid, and strong oxidizing agents such as concentrated nitric acid and permanganate, and is a flattened crystalline compound that maintains a graphite layered structure. When exposed to temperatures of about 200°C or higher, it expands thermally in an accordion shape, for example, by more than 100 times. There is a trade-off relationship between this thermal expandability and the shape stability that allows it to maintain its shape, and it has not been possible to achieve both properties simultaneously.

[0007] Similarly, the heat-expandable fire-resistant sheet described in Patent Document 2 also failed to achieve both heat expandability and shape stability, which allows it to maintain its shape.

[0008] Therefore, the present invention provides a foaming composition that exhibits excellent foaming properties, and the resulting molded article (foamed molded article) has excellent strength, thermal expansion properties during combustion, and shape stability after combustion.

[0009] As a result of diligent research to solve the above problems, the inventors of the present invention have found that the above problems can be solved by using a specific compound composition, and have completed the present invention.

[0010] In other words, the present invention provides the following inventions: [1] A foam molding composition comprising a crosslinkable rubber component, a phosphate-based inorganic compound, a crosslinking agent, and a foaming agent, wherein, per 100 parts by mass of the crosslinkable rubber component, the content of the phosphate-based inorganic compound is 10 to 2000 parts by mass, the content of the crosslinking agent is 0.1 to 30 parts by mass, the content of the foaming agent is 1 to 30 parts by mass, and the content of the thermally expandable layered inorganic compound is less than 5 parts by mass. [2] The foam molding composition according to [1], wherein the content of the thermally expandable layered inorganic compound is less than 3 parts by mass. [3] The foam molding composition according to [1] or [2], wherein the content of the thermally expandable layered inorganic compound is 0 parts by mass. [4] The foam molding composition according to any one of [1] to [3], wherein the phosphate-based inorganic compound comprises at least one selected from aluminum hydrogen phosphite or disaluminum phosphate. [5] The foam molding composition according to any one of [1] to [4], wherein the content of the phosphoric acid-based inorganic compound is 70 to 1400 parts by mass. [6] The foam molding composition according to any one of [1] to [5], wherein the content of the phosphoric acid-based inorganic compound is 130 to 800 parts by mass. [7] A foamed molded body of the foam molding composition according to any one of [1] to [6]. [8] A member comprising the foamed molded body according to [7]. [9] The member according to [8] used in joinery, fireproofing of steel frames, soffit vents, or partition penetration holes.

[10] The member according to [8] used in batteries.

[0011] According to the present invention, it is possible to provide a foam molding composition that exhibits excellent foaming properties, and the resulting molded article (foamed molded article) has excellent strength, thermal expansion properties during combustion, and dimensional stability after combustion. Foamed molded articles made from such a foam molding composition can be used, for example, in building fixtures, fireproofing for steel frames, soffit vents, partition penetration holes, or components used in batteries. Furthermore, since such a foam molding composition also exhibits excellent adhesion to the substrate after thermal expansion, the residue after thermal expansion adheres to the metal or resin substrate of door and window frames, batteries, etc., preventing it from falling off due to the heat, wind, or deformation of the adherend during a fire.

[0012] Figure 1A is a schematic diagram showing how a foam molded body is attached to the surface of a cylindrical battery cell. Figure 1B is a schematic diagram showing the state after the foam molded body has been attached to the surface of the cylindrical battery cell. This diagram explains the test method for adhesion after thermal expansion.

[0013] The embodiments for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail below.

[0014] The foam molding composition of this embodiment comprises a crosslinkable rubber component, a phosphate-based inorganic compound, a crosslinking agent, and a foaming agent. Each component will be described below.

[0015] <Crossable Rubber> The crosslinkable rubber used in this invention is not particularly limited as long as it can be crosslinked or vulcanized with a crosslinking agent or vulcanizing agent and its strength can be improved. Examples include chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), natural rubber (NR), acrylonitrile-butadiene rubber (NBR), silicone rubber, chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CPE), hydrogenated nitrile rubber (HNBR), acrylic rubber (ACM), urethane rubber, and butyl rubber. These crosslinkable rubbers may be used individually or in combination of two or more types.

[0016] Among these, chloroprene rubber is preferred from the viewpoint of flame retardancy.

[0017] The foam molding composition contains, for example, 5 to 77% by mass of crosslinkable rubber, preferably 10 to 55% by mass, and more preferably 25 to 45% by mass, in 100% by mass of the foam molding composition.

[0018] <Phosphoric Acid-Based Inorganic Compounds> Phosphoric acid-based inorganic compounds are used as thermally expandable compounds to provide shape stability to foamed molded products that undergo significant thermal expansion and maintain their expanded form when exposed to high temperatures such as 600°C.

[0019] The phosphoric acid-based inorganic compound preferably includes at least one of the following: phosphoric acid-based compounds, phosphite-based compounds, hypophosphite-based compounds, metaphosphoric acid-based compounds, pyrophosphoric acid-based compounds, and polyphosphoric acid-based compounds.

[0020] Examples of phosphate compounds include monoaluminum phosphate, monosodium phosphate, monopotassium phosphate, monocalcium phosphate, monozinc phosphate, dialuminum phosphate, disodium phosphate, dipotassium phosphate, dicalcium phosphate, dizinc phosphate, trialuminum phosphate, trisodium phosphate, tripotassium phosphate, tricalcium phosphate, trizinc phosphate, trimagnesium phosphate, monoammonium phosphate, diammonium phosphate, tricalcium phosphate, and aluminum phosphate.

[0021] Examples of phosphite compounds include aluminum phosphite, aluminum hydrogen phosphite, sodium phosphite, potassium phosphite, calcium phosphite, and zinc phosphite.

[0022] Examples of hypophosphite compounds include aluminum hypophosphite, sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, and zinc hypophosphite.

[0023] Examples of metaphosphate compounds include aluminum metaphosphate, sodium metaphosphate, potassium metaphosphate, calcium metaphosphate, zinc metaphosphate, and sodium hexametaphosphate.

[0024] Examples of pyrophosphate compounds include sodium pyrophosphate.

[0025] Examples of polyphosphate compounds include ammonium polyphosphate, melamine-modified ammonium polyphosphate, sodium tripolyphosphate, sodium pentapolyphosphate, sodium tetrapolyphosphate, and potassium tripolyphosphate.

[0026] The content of the phosphoric acid-based inorganic compound is 10 to 2000 parts by mass per 100 parts by mass of crosslinkable rubber, preferably 70 to 1400 parts by mass, and more preferably 130 to 800 parts by mass. If the content of the phosphoric acid-based inorganic compound is less than 10 parts by mass, the thermal expansion properties will be poor. If the content of the phosphoric acid-based inorganic compound exceeds 2000 parts by mass, the foaming properties during foam molding will be poor (the hardness of the foamed molded article will be too high). The content of the phosphoric acid-based inorganic compound may be, for example, 10, 50, 70, 100, 130, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000 parts by mass per 100 parts by mass of crosslinkable rubber, and may be within the range of any two of the values ​​exemplified here.

[0027] The phosphate-based inorganic compound preferably contains a phosphite compound and a phosphate compound, and more preferably contains aluminum hydrogen phosphite or disaluminum phosphate. The inclusion of aluminum hydrogen phosphite or disaluminum phosphate tends to improve the shape stability after thermal expansion.

[0028] These phosphate-based inorganic compounds can be used individually or in combination of two or more.

[0029] <Thermally Expandable Layered Inorganic Compounds> Thermally expandable layered inorganic compounds may be used to assist the thermal expansion of phosphoric acid-based inorganic compounds, in addition to non-layered phosphoric acid-based inorganic compounds. There are no particular limitations on thermally expandable compounds other than phosphoric acid-based inorganic compounds as long as they expand when heated, but for example, thermally expandable layered compounds such as thermally expandable layered inorganic compounds can be used.

[0030] As thermally expandable layered inorganic compounds, any known inorganic compound having a layered structure that expands when heated can be used, such as vermiculite, kaolin, mica, and thermally expandable graphite. Thermally expandable graphite is a crystalline compound that maintains a graphite layered structure, obtained by treating powders of natural graphite, pyrolysis graphite, etc., with inorganic acids such as sulfuric acid and nitric acid, and strong oxidizing agents such as concentrated nitric acid and permanganate. When exposed to temperatures of around 200°C or higher, these expand by more than 100 times, for example. In addition to deacidification treatment, various types of powders of natural graphite, pyrolysis graphite, etc., are available, including those that have undergone neutralization treatment, and all types can be used.

[0031] The thermally expandable graphite used in this invention preferably has an average aspect ratio of 20 or more. An average aspect ratio of 20 or more allows for sufficient filling of the frame structure constituting the opening frame of building components such as fire-resistant resin sashes, and it can also be suitably used for steel frame covering.

[0032] The average aspect ratio is the ratio of the average horizontal diameter to the vertical thickness. Since the thermally expandable graphite used in this invention is generally flat, the vertical direction can be considered to coincide with the thickness direction and the horizontal direction with the diameter direction. Therefore, the aspect ratio is calculated by dividing the maximum horizontal dimension by the vertical thickness. The aspect ratio is then measured for a sufficiently large number of graphite pieces, i.e., 10 or more, and the average value is taken as the average aspect ratio. The average particle size of the thermally expandable graphite can also be determined as the average value of the maximum horizontal dimension. The maximum horizontal dimension and thickness of the thermally expandable graphite can be measured, for example, using a field emission scanning electron microscope (FE-SEM).

[0033] The content of the thermally expandable layered inorganic compound is less than 5 parts by mass, preferably less than 3 parts by mass, and more preferably 0 parts by mass, per 100 parts by mass of the crosslinkable rubber component. If the content of the thermally expandable layered inorganic compound is 5 parts by mass or more, the shape stability after thermal expansion deteriorates. Specifically, the content of the thermally expandable layered inorganic compound is, for example, 0, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, or 4 parts by mass per 100 parts by mass of the crosslinkable rubber component, and may be within the range between any two of the values ​​exemplified here, or less than either of them.

[0034] <Foaming Agent> A foaming agent is a substance that generates gas when heated. The foaming agent is a component excluding thermally expandable layered inorganic compounds and phosphoric acid-based inorganic compounds. The foaming agent is used to obtain a foamed molded article from the foaming molding composition (rubber composition) of this embodiment. When heated to about 200°C (for example, 180-240°C or 200-220°C), the foaming agent generates gas and transforms the foaming molding composition into a foamed molded article. Foaming agents are broadly classified into chemical foaming agents and physical foaming agents, and chemical foaming agents can be classified into organic foaming agents and inorganic foaming agents. The foaming agent used in the foaming molding composition of this embodiment is preferably an organic foaming agent or an inorganic foaming agent.

[0035] Examples of organic blowing agents include azo-based blowing agents such as azodicarbonamide (ADCA), azobisisobutyronitrile, azodiaminobenzene, and azocyclohexylnitrile; nitroso-based blowing agents such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethylN,N'-dinitrosotelephthalamide; sulfonyl hydrazide-based blowing agents such as p,p'-oxybisbenzenesulfonyl hydrazide (OBSH), benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, and diphenylsulfone-3,3'-disulfonyl hydrazide; and microspheres and melamine.

[0036] Examples of inorganic foaming agents include ammonium bicarbonate, ammonium carbonate, sodium bicarbonate, ammonium nitrite, and calcium azide.

[0037] Among these, organic blowing agents are more preferred, and azodicarbonamide (ADCA) is even more preferred. These blowing agents may be used alone or in combination of two or more.

[0038] The foaming agent content is 1 to 30 parts by mass, preferably 5 to 25 parts by mass, and more preferably 10 to 20 parts by mass, per 100 parts by mass of the crosslinkable rubber component. If the foaming agent content is less than 1 part by mass, the foaming properties are poor and the material becomes hard. If the foaming agent content exceeds 30 parts by mass, the durability, such as tensile strength, deteriorates. Specifically, the foaming agent content may be, for example, 1, 5, 8, 10, 15, 17, 20, 25, or 30 parts by mass per 100 parts by mass of the crosslinkable rubber component, and may be within the range of any two of the values ​​exemplified here.

[0039] <Crosslinking Agents> Crosslinking agents are not particularly limited as long as they can crosslink or vulcanize rubber, but examples include sulfur, sulfur compounds such as polysulfides, oxime compounds such as p-quinone dioxime and p,p'-dibenzoylquinone oxime; organic peroxide compounds such as t-butyl hydroperoxide, acetylacetone peroxide, and cumene hydroperoxide; magnesium oxide, zinc oxide (1 type), zinc oxide (2 types), zinc oxide (3 types). These crosslinking agents may be used alone or in combination of two or more types.

[0040] The crosslinking agent preferably contains at least one of zinc oxide and sulfur. For example, zinc oxide is preferred for materials containing chlorine moieties, such as chloroprene rubber (CR) and chlorosulfonated polyethylene rubber (CSM), while sulfur is preferred for EPDM and butyl rubber.

[0041] The crosslinking agent content is 0.1 to 30 parts by mass, preferably 1 to 22 parts by mass, and more preferably 3 to 13 parts by mass, per 100 parts by mass of the crosslinkable rubber component. If the crosslinking agent content is less than 0.1 parts by mass, durability such as tensile strength will be poor. If the crosslinking agent content exceeds 30 parts by mass, foaming properties will be poor and the material will become hard. Specifically, the crosslinking agent content may be, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 15, 20, 22, 25, or 30 parts by mass per 100 parts by mass of the crosslinkable rubber component, and may also be within the range of any two of the values ​​exemplified here.

[0042] <Other Components> In this embodiment, plasticizers (softeners), antioxidants, processing aids, lubricants, tackifiers, fibrous organic compounds, inorganic compounds (excluding phosphate-based inorganic compounds, thermally expandable layered inorganic compounds, and foaming agents), crosslinking accelerators, carbonizing agents, flame retardants, etc., which are commonly used in rubber compositions for foam molding, may be used in combination, to the extent that they do not hinder the effect.

[0043] <Other Inorganic Compounds> The shapes of other inorganic compounds include, for example, spherical, ellipsoidal, cuboidal, rectangular, random, and fibrous shapes, and they may be hollow or solid. The average particle size of particulate inorganic compounds is, for example, 10 to 1000 μm, preferably 20 to 800 μm, more preferably 30 to 500 μm, and even more preferably 40 to 200 μm. "Average particle size" refers to the particle size at 50% of the cumulative value in the particle size distribution determined by laser diffraction / scattering. These may be used individually or in combination of two or more.

[0044] As other inorganic compounds, for example, metal oxides such as alumina, silica, aluminosilicate, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, etc.; hydrous inorganic substances such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, hydrotalcite, etc.; metal carbonates such as basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate, barium carbonate, etc.; calcium salts such as calcium sulfate, calcium silicate, etc.; glass beads, silica-based balloons, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon balloons, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, zinc borate, various magnetic powders, fly ash, inorganic hollow fillers, perlite, obsidian, pearlite, pumice, diatomaceous earth, dehydrated sludge, boron, sodium tetraborate hydrate (borax), etc. can be mentioned. These may be used alone or in combination of two or more. Among these, from the viewpoint of flame retardancy, it is preferable to contain aluminum hydroxide.

[0045] <Plasticizer (Softening Agent)> The softening agent is not particularly limited. For example, rapeseed oil, cottonseed oil, palm oil, coconut oil, peanut oil, sub (factice), tall oil, pine tar, process oil (paraffin-based oil, naphthenic oil, and aromatic-based process oil), carboxylic acid ester-based plasticizers (phthalic acid ester, adipic acid ester, sebacic acid ester, maleic acid ester, fumaric acid ester, trimellitic acid ester, citric acid ester, oleic acid ester, ricinoleic acid ester, stearic acid ester, glycolic acid ester, etc.), phosphate ester-based plasticizers (tritolyl phosphate, triisopropylphenyl phosphate, etc.), sulfur factice, etc. can be mentioned. The softening agent may be used alone or in combination of two or more.

[0046] Crosslinking accelerators are used to promote the crosslinking of rubber and are not particularly limited, but examples include thiuram compounds such as tetramethylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, and dipentamethylenethiuram tetrasulfide; thiazole compounds such as 2-mercaptobenzothiazole and dibenzothiazole disulfide; carbamate compounds such as zinc dimethyldithiocarbamate and zinc dibutyldithiocarbamate; aldehyde amine compounds such as n-butyraldehyde aniline; sulfenamide compounds such as N-cyclohexyl-2-benzothiadylsulfenamide; guanidine compounds such as diorthotrylguanidine and diorthonitrileguanidine; thiourea compounds such as thiocarbanilide, diethylthiourea, and trimethylthiourea; and metal compounds such as zinc oxide. Crosslinking accelerators may be used individually or in combination of two or more of these. The amount of crosslinking accelerator used is preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the crosslinkable rubber component.

[0047] The carbonizing agent generally has the effect of forming a thick foamed layer with superior heat insulation properties by dehydrating and carbonizing itself along with the carbonization of the binder due to fire. The carbonizing agent is not particularly limited as long as it has this effect, and the same carbonizing agents as those used in known foamed refractory materials can be used. Examples include polyhydric alcohols such as pentaerythritol, dipentaerythritol, and trimethylolpropane, as well as starch and casein. These can be used one or more at a time. Among these, dipentaerythritol is particularly preferred because it has excellent dehydration cooling effect and foamed layer formation effect.

[0048] Examples of the flame retardant include organic phosphorus compounds such as tricresyl phosphate and diphenyl cresyl phosphate; chlorine compounds such as chlorinated polyphenyl, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, pentachlorinated fatty acid ester, perchloropentacyclodecane, chlorinated naphthalene, and tetrachlorophthalic anhydride; antimony compounds such as antimony trioxide and antimony pentachloride; phosphorus compounds such as phosphorus trichloride and phosphorus pentachloride; and other inorganic compounds such as zinc borate and sodium borate, etc.

[0049] When both a charring agent and a flame retardant are blended, the weight ratio thereof is preferably 2:8 to 8:2, and more preferably 3:7 to 7:3. Further, the total amount of the charring agent and the flame retardant is preferably 10 to 500 parts by mass with respect to 100 parts by mass of the matrix polymer component.

[0050] The composition for foam molding may contain a low molecular weight polyhydric alcohol compound. The content of the low molecular weight polyhydric alcohol compound is less than 30 parts by mass, preferably less than 10 parts by mass, and more preferably 0 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component. Specifically, the content of the low molecular weight polyhydric alcohol compound is, for example, 0, 5, 10, 15, 20, 25, 29 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component, and may be within the range between any two of the values exemplified herein, or less than any of them.

[0051] The low molecular weight polyhydric alcohol compound is a compound having two or more hydroxyl groups in the molecule and having a molecular weight of 500 or less. Examples of the low molecular weight polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, glycerin, butylene glycol, 1,4 - butanediol, 1,6 - hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, inositol, mannitol, glucose, fructose, etc. The molecular weight of the low molecular weight polyhydric alcohol is, for example, 50 to 500, and for example, 50, 100, 150, 200, 250, 三十、三百五十、四百、四百五十、五百であり、ここで例示した数値の何れか2つの間の範囲内であってもよい。

[0052] The foam molding composition of the present invention can be obtained, for example, by blending and kneading each component in a predetermined proportion. The method for producing a foam molded article according to another embodiment is not particularly limited, but includes a blending step to obtain the foam molding composition, a molding step to mold the foam molding composition into a desired shape, a foaming step to heat the foaming agent above its foaming start temperature to cause foaming, and a crosslinking step to heat the foaming agent above its crosslinking start temperature to cause crosslinking. The foaming step and the crosslinking step may be performed as separate steps or simultaneously.

[0053] In another embodiment, the component comprises a foamed molded body. The component may consist solely of the foamed molded body, or it may be composed of other components as appropriate. The foamed molded body or component may be used for component fittings, fireproofing of steel frames, soffit vents, or partition penetration holes. The foamed molded body or component may also be used to cover batteries.

[0054] For example, the component may have components other than the foam molded body laminated onto it, or a base material may be provided on at least one surface of the foam molded body. The base material may be a combustible material layer, a semi-noncombustible material layer, or a noncombustible material layer. The thickness of the base material is not particularly limited, but is for example 5 μm to 1 mm. Examples of materials used for the combustible material layer include one or more types of materials such as cloth, paper, wood, and resin film. When the base material is a semi-noncombustible material layer or a noncombustible material layer, examples of materials used include metals and inorganic materials, and more specifically, woven or nonwoven fabrics made of glass fibers, ceramic fibers, carbon fibers, and graphite fibers. Alternatively, composite materials of these fibers and metals may be used, for example, aluminum glass cloth is preferred. Furthermore, an adhesive layer may be laminated onto the foam molded body. The use of an adhesive layer makes it possible to easily adhere the foam molded body to other components. The adhesive layer may be provided on top of the base material, or it may be formed directly on the surface of the foam molded body. Alternatively, a double-sided adhesive tape having adhesive layers on both sides of the base material may be used. In this case, one adhesive layer is used to attach to the foamed molded body, and the other adhesive layer is used to attach to other components.

[0055] Conventional mixing equipment for kneading the compound includes known mixers, Banbury mixers, kneader mixers, and double-roll mixers. Conventional molding equipment for molding the kneaded compound includes known press molding, extrusion molding, and calendering. Generally, the compound is extruded into the product shape using a rubber extruder, then introduced into a crosslinking tank, and crosslinking and foaming can be performed by heating with hot air, a fluidized bed, microwaves, or other means. The shape of the foamed molded product can be designed as appropriate for the application, such as in the form of a sheet or tape.

[0056] <Characteristics> The foam molding composition is prepared by foaming and crosslinking a foam molded body at 200°C for 4 minutes. A test piece measuring 30 mm in length, 30 mm in width, and 10 mm in thickness is prepared, and the Shore E hardness measured in accordance with JIS K6253 under a load of 1 kg and at 21°C is preferably less than 35, more preferably less than 30, and even more preferably less than 25. The lower limit of the Shore E hardness may be, for example, 10 or higher.

[0057] The foam molding composition is prepared by foaming and crosslinking a foamed molded body at 200°C for 4 minutes. A 2 mm thick test piece is prepared, punched out in a dumbbell shape (size 3) according to JIS K6251, and the tensile strength measured at a tensile speed of 500 mm / min is preferably 0.5 MPa or higher, more preferably 1 MPa or higher, and even more preferably 2 MPa or higher. The upper limit of the tensile strength may be, for example, 6 MPa or less.

[0058] The foam molding composition is prepared by foaming and crosslinking a foamed molded body at 200°C for 4 minutes. A test piece measuring 2 mm thick, 30 mm long, and 30 mm wide is prepared from this foamed molded body and heat-treated at 600°C for 0.5 hours. The measured volume expansion ratio is preferably 2 times or more, more preferably 5 times or more, and even more preferably 10 times or more. The upper limit of the volume expansion ratio may be, for example, 20 times or less. The volume expansion ratio is calculated by dividing the volume after heat treatment by the volume before heat treatment.

[0059] The foam molding composition is prepared by foaming and crosslinking a foamed molded body at 200°C for 4 minutes. A test specimen with a thickness of 2 mm, a length of 30 mm, and a width of 30 mm is prepared from the foamed molded body. The test specimen is heat-treated at 600°C for 0.5 hours. A three-point bending test is performed on the test specimen using a three-point bending test fixture (upper pressing tip R1 mm and width 80 mm, lower two-point support side R1 mm and width 80 mm, distance between supports 20 mm). The strength (three-point bending fracture strength) obtained when the heat-expanded test specimen is fractured at a compression rate of 50 mm / min is preferably 5 N or more, more preferably 20 N or more, and even more preferably 30 N or more. The upper limit of the strength (three-point bending fracture strength) may be, for example, 50 N or less.

[0060] A foamed molded body obtained by foaming and crosslinking a foam molding composition at 200°C for 4 minutes is prepared as a test piece measuring 30 mm in length, 30 mm in width, and 2 mm in thickness. This is placed on a calcium silicate board and left in an atmosphere maintained at 600°C for 0.5 hours to allow thermal expansion. As shown in Figure 2, the surface of the calcium silicate board to which the sample is attached is fixed parallel to the vertical direction. The thermally expanded sample is then pressed against the boundary between the calcium silicate board and the expanded sample at a speed of 50 mm / min using the upper pressing jig (tip radius 1 mm and width 80 mm) of a three-point bending test jig. The adhesion strength when the thermally expanded sample is peeled off is preferably 0.5 N or more, more preferably 1.0 N or more, and even more preferably 1.5 N or more. The upper limit of the adhesion strength is, for example, 3.0 N or less.

[0061] <Other Embodiments> Another embodiment of the present invention provides a battery comprising a member made of the foamed molded body described above. The battery typically has at least one battery cell 3, and the foamed molded body is attached to the battery as a member 1 such as a protective material or fireproofing material (Figure 1). The foamed molded body is typically attached to the surface of the battery cell. The battery may have one battery cell or two or more battery cells.

[0062] Battery cells include, but are not limited to, lithium-ion batteries, lithium-ion polymer batteries, nickel-metal hydride batteries, lithium-sulfur batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, sodium-sulfur batteries, lead-acid batteries, and air batteries.

[0063] Batteries are used in, for example, small electronic devices such as mobile phones and smartphones, laptop computers, automobiles, power tools, and the like, but are not limited to these.

[0064] The present invention will be described in more detail below with reference to examples, but these examples are not intended to limit the present invention. The unit of measurement for the amount of each substance used below is parts by mass. The raw materials used in the examples and comparative examples are as follows.

[0065] [Examples and Comparative Examples] The mixtures (foaming molding compositions) prepared according to the proportions shown in the table were kneaded uniformly using a 3L pressure kneader (temperature: 100°C, time: 10 minutes) and then a roll mill (temperature: 40°C, time: 10 minutes) to form sheets. Next, the obtained sheets were foamed and crosslinked at 200°C for 4 minutes to obtain foamed molded articles. The physical properties were evaluated, and the results are shown in the table.

[0066] 1. Materials [Cross-linkable rubber] ・Chloroprene rubber (CR): S-40V manufactured by Denka Co., Ltd. ・EPDM rubber (EPDM): EPT3092M manufactured by Mitsui Chemicals, Inc. ・Butyl rubber: BUTYL268 manufactured by JSR Corporation [Phosphoric acid-based inorganic compounds] ・Aluminum hydrogen phosphite (AL hydrogen phosphite): NSF manufactured by Taihei Chemical Industry Co., Ltd. ・Dialuminum phosphate (AL diphosphate): Taihei Chemical Industry Co., Ltd. ・Sodium phosphite (Na phosphite): Taihei Chemical Industry Co., Ltd. ・Ammonium polyphosphate (NH4 polyphosphate): SCM Industrial Chemical Co., Ltd. , "HP-APP II" [Thermally expandable layered inorganic compound] ・Thermally expandable graphite: ADT501 (aspect ratio 25.2): ADT Corporation's "ADT501" aspect ratio 25.2 [Foaming agent] ・Azodicarbonamide (ADCA): Sankyo Chemicals Co., Ltd.'s "Cellmic C-1" ・Sodium bicarbonate: Sankyo Chemicals Co., Ltd.'s "Cellmic 417" [Crosslinking agent] ・Sulfur: Hosoi Chemical Industry Co., Ltd.

[0067] 2. Various Evaluations The following measurements and evaluations were performed on the foamed molded articles of each example and comparative example. The results are shown in the table.

[0068] The details of the evaluation method are as follows:

[0069] <Foaming Properties (Shore E Hardness)> Foamed molded bodies of the examples and comparative examples were prepared as test pieces measuring 30 mm in length x 30 mm in width x 10 mm in thickness, and the Shore E hardness was measured at a load of 1 kg in an environment of 21°C in accordance with JIS K6253. Based on the measured values, the hardness was judged according to the following evaluation criteria. [Evaluation Criteria] ◎: Shore E hardness is less than 25. ○: Shore E hardness is 25 or more and less than 30. △: Shore E hardness is 30 or more and less than 35. ×: Shore E hardness is 35 or more.

[0070] <Durability (Tensile Strength)> Foam molded bodies of the examples and comparative examples were prepared as 2 mm thick test pieces, punched out in a dumbbell shape (Type 3) according to JIS K6251, and the tensile strength of the test pieces was measured at a tensile speed of 500 mm / min and judged according to the following criteria: ◎: Tensile strength of 2 [MPa] or more ○: Tensile strength of 1 [MPa] or more and less than 2 [MPa] △: Tensile strength of 0.5 [MPa] or more and less than 1 [MPa] ×: Tensile strength less than 0.5 [MPa]

[0071] <Thermal Expansion> Foamed molded articles of the examples and comparative examples were prepared as test pieces with a thickness of 2 mm, a length of 30 mm, and a width of 30 mm. They were heat-treated at 600°C for 0.5 hours, and their expansion ratio was measured. Specifically, the volume expansion ratio was calculated by dividing the volume after heat treatment by the volume before heat treatment, and the thermal expansion properties were determined according to the following criteria. Note that the volume was calculated by actually measuring the pressure, width, and length. ◎: Volume expansion ratio of 10 times or more ○: Volume expansion ratio of 5 times or more and less than 10 times △: Volume expansion ratio of 2 times or more and less than 5 times ×: Volume expansion ratio less than 2 times

[0072] <Shape Stability After Thermal Expansion> After evaluating the thermal expansion properties described above, a three-point bending test fixture (upper pressing tip R1 mm and width 80 mm, lower two-point support side R1 mm, width 80 mm, distance between supports 20 mm) was used to measure the strength (three-point bending fracture strength) of the specimen after thermal expansion when it was fractured under the condition of a compression rate of 50 mm / min. The shape stability after thermal expansion was then determined according to the following criteria: ◎: Three-point bending fracture strength of 30 [N] or more ○: Three-point bending fracture strength of 20 [N] or more and less than 30 [N] △: Three-point bending fracture strength of 5 [N] or more and less than 20 [N] ×: Three-point bending fracture strength less than 5 [N]

[0073] <Adhesion after thermal expansion> Using the foamed molded bodies of the examples and comparative examples, test pieces measuring 30 mm in length, 30 mm in width, and 2 mm in thickness were prepared, placed on a calcium silicate board, and left in an atmosphere maintained at 600°C for 0.5 hours to allow thermal expansion. As shown in Figure 2, the surface of the calcium silicate board to which the sample was attached was fixed parallel to the vertical direction, and the thermally expanded sample was pressed against the boundary between the calcium silicate board and the expanded sample at a speed of 50 mm / min using the upper pressing jig (tip radius 1 mm and width 80 mm) of a three-point bending test jig, and the adhesion strength when the thermally expanded sample was peeled off was measured. Based on the adhesion strength, the adhesion after thermal expansion was judged according to the following criteria. If the thermally expanded sample fell before the upper pressing jig was pressed, the adhesion strength was set to 0.0 [N]. ◎: 1.5 [N] or more ○: 1.0 [N] or more, less than 1.5 [N] △: 0.5 [N] or more, less than 1.0 [N] ×: Less than 0.5 [N]

[0074]

[0075]

[0076]

[0077]

[0078] 1: Components 3: Battery cells

Claims

1. A foam molding composition comprising a crosslinkable rubber component, a phosphate-based inorganic compound, a crosslinking agent, and a foaming agent, wherein, per 100 parts by mass of the crosslinkable rubber component, the content of the phosphate-based inorganic compound is 10 to 2000 parts by mass, the content of the crosslinking agent is 0.1 to 30 parts by mass, the content of the foaming agent is 1 to 30 parts by mass, and the content of the thermally expandable layered inorganic compound is less than 5 parts by mass.

2. The foam molding composition according to claim 1, wherein the content of the thermally expandable layered inorganic compound is less than 3 parts by mass.

3. The foam molding composition according to claim 1, wherein the content of the thermally expandable layered inorganic compound is 0 parts by mass.

4. The foam molding composition according to claim 1, wherein the phosphate-based inorganic compound comprises at least one selected from aluminum hydrogen phosphite or disaluminum phosphate.

5. The foam molding composition according to claim 1, wherein the content of the phosphoric acid-based inorganic compound is 70 to 1400 parts by mass.

6. The foam molding composition according to claim 1, wherein the content of the phosphoric acid-based inorganic compound is 130 to 800 parts by mass.

7. A foamed molded article of a foamed molding composition according to any one of claims 1 to 6.

8. A member comprising the foamed molded body described in claim 7.

9. The member according to claim 8, used for joinery, fireproofing of steel frames, soffit ventilation openings, or partition penetration holes.

10. The component according to claim 8, used in a battery.

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