KR102174106B1 - Thermoplastic resin foam and foam-based sealing material - Google Patents

Abstract

An object of the present invention is to provide a resin foam and a foam sealing material capable of achieving excellent processability by imparting remarkable anisotropy to shear fracture in a specific direction while maintaining flexibility. It is a resin foam containing a thermoplastic resin, the maximum breaking strength Smax of the foam is 0.1 MPa to 3 MPa, and the ratio Smax of the maximum breaking strength Smax and the breaking strength Smin in a direction orthogonal to the direction showing the maximum breaking strength /Smin is 1.5 to 6, characterized in that the resin foam. In addition, the breaking elongation SSmax in the direction showing the maximum breaking strength is 200% or less, and the breaking elongation SSmax in the direction showing the maximum breaking strength and the breaking elongation SSmin in a direction orthogonal to the direction showing the maximum breaking strength. It is preferable that the breaking elongation ratio SSmax/SSmin is 1.5-6.

Description

Thermoplastic resin foam and foam sealing material {THERMOPLASTIC RESIN FOAM AND FOAM-BASED SEALING MATERIAL}

The present invention relates to a thermoplastic resin foam and a foam sealing material.

Conventionally, resin foams have been used as gasket materials for mobile phones and portable information terminals, or as packing sheets or tapes, sealing tapes, protective sheets or tapes.

As the resin foam, for example, a microcellular urethane resin foam having a continuous cell structure with low foaming, compression molding of high foaming urethane, a polyethylene resin foam having a foaming ratio of about 30 times having closed cells, and a density of 0.2 g /Cm 3 or less polyolefin resin foam (refer to Patent Documents 1 and 2) and the like have been proposed. And it is manufactured in the form of a sheet or a tape by stretching or extrusion of a resin having a controlled surface shape.

Such a resin foam is usually applied by being processed into a predetermined shape and fixed to a predetermined site. However, since the resin foam is flexible and fragile, fracture may occur unintentionally during processing or fixing, etc. there was. Alternatively, a large load is applied to the cutting or shearing in a predetermined direction, and during this cutting or shearing, it is extended in an unintended direction or the blade breaks, or it becomes difficult to form an opportunity for breakage by extension, and hand cutting It was not satisfactory enough for the hand-cutting property at the time of processing, for example, there may be a decrease in the property.

Japanese Patent Publication No. 2005-227392 Japanese Patent Publication No. 2007-291337

An object of the present invention is to provide a resin foam and a foam sealing material capable of imparting remarkable anisotropy to shear fracture in a specific direction while maintaining flexibility and realizing good workability.

The present invention includes the following inventions.

(1) It is a resin foam containing a thermoplastic resin,

The maximum breaking strength Smax of the foam is 0.1 MPa to 3 MPa, and

The resin foam, wherein the ratio Smax/Smin of the maximum breaking strength Smax and the breaking strength Smin in a direction orthogonal to the direction representing the maximum breaking strength is 1.5 to 6.

(2) the breaking elongation SSmax in the direction showing the maximum breaking strength is 200% or less,

The resin foam according to (1), wherein the breaking elongation SSmax in the direction showing the maximum breaking strength and the breaking extension SSmin in the direction orthogonal to the direction showing the maximum breaking strength are 1.5 to 6.

(3) (1) or (2) wherein the ratio Cmax/Cmin of the bubble size Cmax in the direction showing the maximum breaking strength and the bubble size Cmin in the direction orthogonal to the direction showing the maximum breaking strength is 1.2 to 5 Of resin foam.

(4) The resin foam according to any one of (1) to (3), wherein the apparent density is 0.01 to 0.2 g/cm 3.

(5) The resin foam according to any one of (1) to (4) obtained by decompression treatment of a thermoplastic resin composition impregnated with a high-pressure gas.

(6) The resin foam according to (5), wherein the gas is an inert gas.

(7) The resin foam according to (6), wherein the inert gas is carbon dioxide or nitrogen.

(8) The resin foam according to any one of (5) to (7), wherein the gas is a gas in a supercritical state.

(9) A foam sealing material comprising the resin foam according to any one of (1) to (8) above.

(10) The foam sealing material of the base material (9) having an adhesive layer disposed on one or both sides of the foam.

(11) The foam sealing material of the base (10), wherein the adhesive layer is disposed on the surface of the resin foam through the film layer.

Advantageous Effects of Invention According to the present invention, it is possible to provide a resin foam and a foam sealing material capable of realizing good processability by imparting remarkable anisotropy to shear fracture in a specific direction while maintaining flexibility.

1 is a plan view of a sample for implementing a method for evaluating hand cutability of a resin foam of the present invention.
Fig. 2 is a schematic diagram showing an evaluation form of a sample in a method for evaluating hand cutability of a resin foam of the present invention.
Fig. 3 is a schematic view of a main part in a manufacturing process for explaining the method of stretching a resin foam of the present invention.

The resin foam of the present invention is a foam containing a thermoplastic resin, and is obtained by foaming or molding a thermoplastic resin composition. The shape of the resin foam of the present invention is not particularly limited, and for example, any shape such as a block, a sheet, or a film may be used.

〔Physical properties of resin foam〕

The resin foam of the present invention has a maximum breaking strength Smax of 0.1 MPa to 3 MPa, preferably 0.1 MPa to 2 MPa, more preferably 0.2 MPa to 2 MPa, and still more preferably 0.3 MPa to 2 MPa.

Here, the maximum breaking strength Smax means the greatest breaking strength among breaking strengths in various directions of the resin foam.

In order to obtain such breaking strength, first, the resin foam measures the breaking strength in an arbitrary direction (for example, direction A), and further sets the center X on the axis of the direction A, and with respect to this center X The shaft is rotated by 10°, and the breaking strength in each direction indicated by the shaft is measured (a total of 18 directions). Among them, the breaking strength in the direction having the largest breaking strength (hereinafter sometimes referred to as "the maximum breaking strength direction") is selected, and this is referred to as the maximum breaking strength Smax.

By having such a maximum breaking strength, it is possible to obtain a resin foam having an appropriate strength.

In the resin foam of the present invention, the direction showing the maximum breaking strength is usually the MD direction (flow direction).

In the resin foam of the present invention, the ratio Smax/Smin of the above-described maximum breaking strength Smax and the breaking strength Smin in a direction orthogonal to the direction of the maximum breaking strength is 1.5 to 6, preferably 1.8 to 6, more It is preferably 2 to 6, more preferably 2 to 5.

By having such a breaking strength ratio, the anisotropy in shear fracture in a specific direction can be remarkably improved, so that good workability, particularly hand cutability, can be realized. Accordingly, it becomes possible to use the resin foam of the present invention as an easily openable tape requiring anisotropy, a sheet having excellent field workability, and the like.

In the resin foam of the present invention, the breaking elongation SSmax in the direction of the maximum breaking strength is preferably 200% or less, more preferably 180% or less, and still more preferably 160% or less. Further, it is preferably 100% or more, and more preferably 105% or more.

By having such breaking elongation, elongation at the time of processing or fixing can be prevented. Further, it is possible to effectively prevent breakage caused by elongation of the tape and the like in use as a tape. The elongation of the resin foam can be evaluated as the softness, which is an elongation rate when a predetermined load is applied. For example, if the electrical conductivity under a load of 0.5N is 5.0% or less, it is difficult to elongate, and it can be judged to be good. If the softness under a load of 1.0N is 10.0% or less, it is difficult to extend and can be judged to be good. The softness can be measured by the method described in Examples described later.

In the resin foam of the present invention, the breaking elongation SSmax in the direction of the maximum breaking strength and the breaking elongation ratio SSmax/SSmin of the breaking elongation SSmin in the direction orthogonal to the direction of the maximum breaking strength are preferably 1.5 to 6, more preferably. Is 2 to 6, more preferably 2.5 to 6.

By having such a breaking elongation ratio, since elongation in a direction orthogonal to the maximum breaking direction is reduced, cutting in a specific direction can be made easier.

The resin foam of the present invention has, for example, a closed cell structure or a semi-continuous semi-independent cell structure (a cell structure in which an independent cell structure and a semi-continuous semi-independent cell structure are mixed, and the ratio is not particularly limited). It is desirable. In particular, a cell structure in which the closed cell ratio of the resin foam is 50% or less, preferably 40% or less, and more preferably 35% or less is mentioned. With this range, air is easily escaped from the resin during compression deformation when an impact is applied, and sufficient impact absorption can be exhibited. Further, a cell structure in which the closed cell ratio of the resin foam is 10% or more, preferably 15% or more, and more preferably 20% or more is mentioned. With this range, the passage of fine particles such as dust can be prevented, and the dustproof property can be improved.

In addition, the closed cell ratio can be measured, for example, by the method described in Examples.

In the resin foam of the present invention, the ratio Cmax/Cmin of the cell size Cmax in the direction of the maximum breaking strength and the cell size Cmin in the direction orthogonal to the direction of the maximum breaking strength is preferably 1.2 to 5, more preferably Is 1.2 to 4, more preferably 1.2 to 3.5, and even more preferably 1.3 to 3.5.

Here, the bubble size is taken as the average value of 10 bubble diameters measured by the following method.

First, parallel to the direction of the maximum breaking strength of the resin foam and a direction orthogonal to this direction, each of the main surfaces of the resin foam is cut in a vertical direction (thickness direction) with a cutter to prepare a smooth cross section. Subsequently, these cross sections are observed with a Keyence microscope (for example, the brand name "VHX-600" manufactured by Keyence Corporation). Then, 10 points are extracted from those having a large bubble size within the measurement range of 3000 µm x 2500 µm, the area of the bubbles is converted into a diameter, and their average value is calculated, and it is set as the bubble diameter.

In the resin foam of the present invention, the cell diameter is preferably 50 to 300 µm, more preferably 70 to 300 µm, and further in a vertical direction (thickness direction) cut surface parallel to the maximum breaking strength direction. It is preferably 100 to 300 µm, and even more preferably 100 to 250 µm. In addition, the cell diameter in the cut surface in the vertical direction (thickness direction) parallel to the direction orthogonal to the direction orthogonal to the direction of the maximum breaking strength is preferably 10 to 200 µm, more preferably 30 to 200 µm, and even more preferably It is 50 to 200 µm, and even more preferably 80 to 180 µm.

In the resin foam of the present invention, by making the cell diameter of the foam within this range, anisotropy in the intended direction can be further realized, good processability and hand-cutting properties can be secured, and the cut surface is also uneven. Less, it becomes possible to do it with a sharp side.

The resin foam of the present invention further preferably has an apparent density of 0.01 to 0.20 g/cm 3, more preferably 0.01 to 0.15 g/cm 3, still more preferably 0.01 to 0.10 g/cm 3, and even more preferably 0.02 to 0.08 g/cm 3. When the apparent density is in this range, strength can be sufficiently secured, good workability (especially punching workability) can be obtained, and at the same time, flexibility can be secured.

The resin foam of the present invention has a tensile modulus of preferably 5.0 to 14.0 MPa, more preferably 5.5 to 13.5 MPa, and still more preferably 6.0 to 13.0 MPa. By setting it as such a range, when the resin foam is pulled, plastic deformation does not occur, and extension and fracture in an unintended direction can be effectively prevented. Thereby, the softness is low and excellent workability can be exhibited.

The tensile modulus of elasticity is determined by a tensile test in accordance with JIS K 6767.

[Material of resin foam]

The resin foam of the present invention is formed of a thermoplastic resin or a resin composition containing a thermoplastic resin. As a thermoplastic resin, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, copolymers of ethylene and propylene, ethylene or other α-olefins (for example, butene-1, pentene- 1, a copolymer of hexene-1, 4-methylpentene-1, etc.), ethylene and other ethylenically unsaturated monomers (eg, vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, vinyl alcohol, etc.) ) Polyolefin resins such as copolymers; Styrene resins such as polystyrene and acrylonitrile-butadiene-styrene copolymer (ABS resin); Polyamide resins such as 6-nylon, 66-nylon, and 12-nylon; Polyamide imide; Polyurethane; Polyimide; Polyetherimide; Acrylic resins such as polymethyl methacrylate; Polyvinyl chloride; Polyvinyl fluoride; Alkenyl aromatic resins; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonates such as bisphenol A polycarbonate; Polyacetal; Polyphenylene sulfide, etc. are mentioned.

Thermoplastic resins can be used alone or in combination of two or more. When the thermoplastic resin is a copolymer, it may be a copolymer in any form of a random copolymer or a block copolymer.

As the thermoplastic resin, a polyolefin-based resin is suitable from characteristics such as mechanical strength, heat resistance, and chemical resistance, and molding such as easy melt thermoforming.

As the polyolefin-based resin, appropriately mentioned resins having a wide molecular weight distribution and having a shoulder on the high molecular weight side, non-crosslinked type resins (slightly crosslinked type resins), long-chain branched type resins, and the like are suitably mentioned.

The thermoplastic resin contains a rubber component and/or a thermoplastic elastomer component.

Since the rubber component and the thermoplastic elastomer component have, for example, a glass transition temperature of room temperature or lower (for example, 20°C or lower), the flexibility and shape followability in the case of a resin foam become very good.

The rubber component and the thermoplastic elastomer component are not particularly limited as long as they have rubber elasticity and can be foamed, and for example, natural or synthetic rubbers such as natural rubber, polyisobutylene, polyisoprene, chloroprene rubber, butyl rubber, and nitrile butyl rubber. ; Olefin elastomers such as ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, polybutene, and chlorinated polyethylene; Styrene-based elastomers such as styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, and hydrogenated products thereof; Polyester elastomer; Polyamide elastomers; And various thermoplastic elastomers such as polyurethane elastomers.

These may be used alone or in combination of two or more.

Among them, as the rubber component and/or the thermoplastic elastomer component, an olefin elastomer is preferred. The olefin-based elastomer has good compatibility with the polyolefin-based resin exemplified as a thermoplastic resin.

The olefinic elastomer may be of a type having a structure in which the resin component A (olefin resin component A) and the rubber component B are microphase separated. The resin component A and the rubber component B may be physically dispersed, or the resin component A and the rubber component B may be dynamically heat-treated in the presence of a crosslinking agent (dynamic crosslinkable thermoplastic elastomer, TPV).

In particular, as the olefin elastomer, a dynamic crosslinkable thermoplastic olefin elastomer (TPV) is preferable.

The dynamic crosslinkable thermoplastic olefin elastomer has a higher elastic modulus than TPO (non-crosslinkable thermoplastic olefin elastomer) and has a smaller compression set. Thereby, recovery is good, and when it is made into a resin foam, excellent recovery is shown.

Dynamically crosslinked thermoplastic olefinic elastomer means, as described above, a mixture comprising a resin component A (olefinic resin component A) forming a matrix and a rubber component B forming a domain, in the presence of a crosslinking agent, dynamically heat-treated. It is a polyphase polymer having an island-in-the-sea structure in which crosslinked rubber particles are finely dispersed as a domain (island) in the resin component A as a matrix (sea).

As such a dynamic crosslinking type thermoplastic olefin elastomer, for example, Japanese Patent Laid-Open No. 2000-007858, Japanese Patent Laid-Open No. 2006-052277, Japanese Patent Laid-Open No. 2012-072306, Japanese Patent Laid-Open No. 2012-057068 Japanese Patent Application Publication No. 2010-241897, Japanese Patent Application Publication No. 2009-067969, Japanese Patent Republished Publication No. 03/002654, etc., “Zeosome” (manufactured by Nippon Xeon), “Thermoran” (Mitsubishi Chemical Co., Ltd.), "Salink 3245D" (Toyobo Seki Co., Ltd. product) and the like commercially available.

When the resin constituting the resin foam of the present invention contains a rubber component and/or a thermoplastic elastomer component together with a thermoplastic resin, the content is not particularly limited. For example, in the resin constituting the resin foam of the present invention, the ratio of the thermoplastic resin and the rubber component and/or the thermoplastic elastomer component is preferably 70/30 to 30/70 based on weight, More preferably 60/40 to 30/70, more preferably 50/50 to 30/70, even more preferably 60/40 to 10/90, 58/42 to 10/90, 55 /45 to 10/90. If the ratio of the rubber component and/or the thermoplastic elastomer component is too small, the cushioning property of the resin foam is liable to deteriorate or the recovery after compression may decrease.On the other hand, if the ratio of the rubber component and/or the thermoplastic elastomer component is too large When the foam is formed, gas escape is likely to occur, and it may be difficult to obtain a foam having high foaming properties.

In the resin foam of the present invention, in order to realize flexibility during high compression and to recover the shape after compression, that is, to enable large deformation and not to cause plastic deformation, it is formed of a material having excellent rubber elasticity. Suitable. From that point of view, in the resin foam of the present invention, it is preferable that a rubber component and/or a thermoplastic elastomer component are included together with the above-described thermoplastic resin as a constituting resin.

Moreover, it is preferable that the resin foam of this invention further contains a nucleating agent. When the nucleating agent is contained, the cell diameter can be easily adjusted, and a foam having adequate flexibility and excellent cutting processability can be obtained.

Examples of the nucleating agent include oxides such as talc, silica, alumina, zeolite, calcium carbonate, magnesium carbonate, barium sulfate, zinc oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, mica, and montmorillonite, complex oxides, metal carbonates, and metals. Sulfate, metal hydroxide; Carbon particles, glass fibers, and carbon tubes. Moreover, a nucleating agent is used individually or in combination of 2 or more types.

The average particle diameter of the nucleating agent is not particularly limited, but is preferably 0.3 to 1.5 µm, more preferably 0.4 to 1.2 µm. By setting it as such an average particle diameter, a sufficient function as a nucleating agent can be exhibited. In addition, the nucleating agent does not penetrate the wall of the cell, and a high foaming ratio can be achieved.

This average particle diameter can be measured by a laser diffraction type particle size distribution measurement method. For example, by "MICROTRAC MT-3000" manufactured by LEEDS & NORTHRUP INSTRUMENTS, it is possible to measure (AUTO measurement) from a dispersion diluent of a sample.

In the resin foam of the present invention, the content in the case of containing such a nucleating agent is not particularly limited, and is preferably 0.5 to 150 parts by weight, more preferably 2 to 140 parts by weight, based on 100 parts by weight of the resin constituting it. And more preferably 3 to 130 parts by weight.

Since the resin foam of the present invention is composed of a thermoplastic resin and is easily burned, it is preferable to contain a flame retardant.

As the flame retardant, a non-halogen-non-antimony inorganic flame retardant is preferable.

As such an inorganic flame retardant, a metal hydroxide, a hydrate of a metal compound, etc. are mentioned, for example. More specifically, aluminum hydroxide; Magnesium hydroxide; Hydrates of magnesium oxide or nickel oxide; And hydrates of magnesium oxide and zinc oxide. Among them, magnesium hydroxide is appropriately mentioned. The hydrated metal compound may be surface-treated. Flame retardants are used alone or in combination of two or more.

In the resin foam of the present invention, when the flame retardant is included, the content is preferably 5 to 70 parts by weight, more preferably 25 to 65 parts by weight, based on 100 parts by weight of the constituent resin.

The resin foam of the present invention further has a polar functional group, has a melting point of 50 to 150° C., and may contain at least one aliphatic compound selected from fatty acids, fatty acid amides and fatty acid metal soaps. Among them, fatty acids and fatty acid amides are preferred.

In the resin foam of the present invention, if such an aliphatic compound is contained, the cell structure is less likely to be damaged during processing (especially punching), thereby improving shape recovery, and further improving workability (especially punching processability). do. These aliphatic compounds have high crystallinity, and when added to the thermoplastic resin (especially polyolefin resin), it forms a solid film on the resin surface, thereby preventing the walls of the cells forming the cell structure from blocking each other. I guess this is.

Since such aliphatic compounds are difficult to be compatible with those containing a functional group having a high polarity, particularly with respect to a polyolefin-based resin, it is easy to precipitate on the surface of the resin foam, and the above effect is easily exhibited.

The melting point of the aliphatic compound is preferably 50 to 150° C. from the viewpoint of lowering the molding temperature when foaming the resin composition, suppressing deterioration of the resin (especially polyolefin resin), imparting sublimation resistance, and the like. And more preferably 70 to 100°C.

As the fatty acid, it is preferably one having 18 to 38 carbon atoms, more preferably 18 to 22 carbon atoms. Specifically, stearic acid, behenic acid, 12-hydroxystearic acid, etc. are mentioned. Among them, behenic acid is particularly preferred.

The fatty acid amide is preferably a fatty acid portion having about 18 to 38 carbon atoms, more preferably about 18 to 22 carbon atoms, and may be either monoamide or bisamide. Specifically, stearic acid amide, oleic acid amide, erucic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, and the like are mentioned. Among them, erucic acid amide is particularly preferred.

Examples of the fatty acid metal soap include salts of aluminum, calcium, magnesium, lithium, barium, zinc, and lead of the above fatty acids.

In the resin foam of the present invention, the content in the case where such an aliphatic compound is included is not particularly limited, and is preferably 1 to 5 parts by weight, more preferably 1.5 to 3.5 parts by weight based on 100 parts by weight of the constituent resin. Parts by weight, and more preferably 2 to 3 parts by weight. Thereby, when the resin is foamed and molded, a sufficient pressure can be maintained, the content of the foaming agent (for example, an inert gas such as carbon dioxide) can be secured, and a high foaming ratio can be obtained.

The resin foam of the present invention may contain a lubricant. Thereby, while improving the fluidity|liquidity of a resin composition, thermal deterioration of a resin can be suppressed. The lubricant is used alone or in combination of two or more.

Although it does not specifically limit as a lubricant, For example, Hydrocarbon lubricants, such as liquid paraffin, paraffin wax, microwax, and polyethylene wax; And ester lubricants such as butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, hydrogenated castor oil, stearyl stearate, and the like. In addition, the content of the lubricant can be appropriately selected within a range that does not impair the effects of the present invention.

The resin foam of the present invention may contain other additives as necessary. Examples of such additives include anti-shrinkage agents, anti-aging agents, heat stabilizers, lightfasteners such as HALS, weathering agents, metal inactivators, UV absorbers, light stabilizers, stabilizers such as anti-freeze agents, antibacterial agents, anti-mold agents, dispersants, adhesives. Imparting agents, coloring agents such as carbon black and organic pigments, and fillers. In particular, in the case of using a dynamic crosslinkable thermoplastic olefin elastomer, a composition containing the same may be used as a composition containing additives (eg, coloring agents such as carbon black, softening agents, etc.). These additives are used alone or in combination of two or more.

The content of these additives can be appropriately selected within a range that does not impair the effects of the present invention.

[Method for producing resin foam]

The resin foam of the present invention uses a resin composition obtained by mixing or kneading a thermoplastic resin (including a rubber component and/or a thermoplastic elastomer component), optionally, an additive such as a nucleating agent, an aliphatic compound, and a lubricant, It can be manufactured by foaming or molding a resin composition. In particular, the anisotropic structure of the bubble can be formed by stretching.

The foaming method used when foaming or molding the resin composition is not particularly limited, and for example, a method commonly used such as a physical method and a chemical method may be mentioned. A general physical method is a method in which a low-boiling liquid (foaming agent) such as chlorofluorocarbons or hydrocarbons is dispersed with a resin and then heated to volatilize the blowing agent to form bubbles. In addition, a general chemical method is a method of forming bubbles by gas generated by thermal decomposition of a compound (foaming agent) added to a resin.

In the present invention, as a foaming method, since a foam having a small cell diameter and a high cell density can be easily obtained, a method using a high-pressure gas as a foaming agent is preferable. In particular, a method of using a high-pressure inert gas as the blowing agent is preferred.

As a method of using a high-pressure gas as a foaming agent, a method of impregnating a resin composition with a high-pressure gas and then forming a pressure-reducing process is preferable. Specifically, a high-pressure gas is applied to a non-foamed molded article containing the resin composition. After impregnating, a method of forming through a step of reducing pressure, a method of impregnating a molten resin composition with a gas under a pressurized state and then subjecting it to molding with reduced pressure, and the like.

The inert gas is not particularly limited as long as it is inert with respect to the resin, which is a material of the resin foam, and can be impregnated, and examples thereof include carbon dioxide, nitrogen, and air. These gases may be mixed and used. Among these, carbon dioxide or nitrogen is preferable because the amount of impregnation into the resin is large and the impregnation rate is high.

In addition, from the viewpoint of increasing the impregnation rate into the resin composition, the high-pressure gas (especially an inert gas, furthermore carbon dioxide) is preferably a gas in a supercritical state. In the supercritical state, the solubility of the gas in the resin increases, and high concentration mixing is possible. In addition, in the case of a sudden pressure drop after impregnation, since it is possible to impregnate at a high concentration as described above, the generation of bubble nuclei increases, and the density of the bubbles generated by the growth of the bubble nuclei increases even if the porosity is the same. Can be obtained. For example, the critical temperature of carbon dioxide is 31°C and the critical pressure is 7.4 MPa.

As a method of foaming or molding the resin composition by using a high-pressure gas as the foaming agent, the resin composition is previously molded into a suitable shape such as a sheet shape to obtain a non-foamed resin molded body (non-foamed resin molded product). A batch method in which a non-foamed resin molded body is impregnated with a high-pressure gas to release the pressure to thereby foam is mentioned. Further, a continuous method in which the resin composition is kneaded with a high-pressure gas under pressure, the pressure is released while molding is performed, and molding and foaming are performed simultaneously is exemplified.

When foaming or molding a resin composition in a batch method, examples of a method of forming an unfoamed resin molded body for foaming include a method of molding the resin composition using an extruder such as a single screw extruder or a twin screw extruder; A method of uniformly kneading the resin composition using a kneader equipped with blades such as rollers, cams, kneaders, Banbury type, etc., and press molding to a predetermined thickness using a press of a hot plate or the like; The method of molding a resin composition using an injection molding machine, etc. are mentioned. In addition, the non-foamed resin molded body can also be formed by other molding methods other than extrusion molding, press molding, and injection molding. In addition, the shape of the non-foamed resin molded body is not particularly limited, and various shapes can be selected depending on the application, and examples thereof include a sheet shape, a roll shape, a plate shape, and a block shape.

In this way, when the resin composition is foamed or molded in a batch method, the resin composition can be molded by an appropriate method for obtaining an unfoamed resin molded body having a desired shape or thickness.

In the case of foaming or molding the resin composition in a batch method, the obtained non-foamed resin molded body is placed in a pressure-resistant container (high-pressure container), and high-pressure gas (especially inert gas, furthermore carbon dioxide) is injected (introduced), and the non-foamed resin molded body Gas impregnation process in which high-pressure gas is impregnated into the inside, decompression process in which pressure is released (usually up to atmospheric pressure) when sufficiently high-pressure gas is impregnated, to generate bubble nuclei in the resin, in some cases (if necessary) Then, through a heating step of growing a bubble core by heating, bubbles are formed in the resin. You may grow a bubble core at room temperature without providing a heating process.

In the foaming or molding of the resin composition in a continuous manner, high-pressure gas (especially inert gas, further carbon dioxide) is injected (introduced) while kneading the resin composition using an extruder such as a single screw extruder or a twin screw extruder, By a kneading impregnation step in which a sufficiently high pressure gas is impregnated into the resin composition, the pressure is released by extruding the resin composition through a die installed at the tip of the extruder (usually up to atmospheric pressure), and molding and foaming are performed simultaneously. Foaming or molding is mentioned. These kneading and impregnation steps and molding decompression steps may be performed using an injection molding machine or the like in addition to an extruder. In addition, in the case of foaming or molding of the resin composition in a continuous manner, a heating step of growing bubbles by heating may be provided as needed.

In either the batch method or the continuous method, after growing the air bubbles, if necessary, it may be rapidly cooled with cold water or the like to fix the shape. Further, the high-pressure gas introduction may be performed continuously or discontinuously. As the heating method for growing the bubble nuclei, known methods such as water bath, oil bath, heat roll, hot air oven, far-infrared ray, near-infrared ray, and microwave can be adopted.

Further, in the case of producing the resin foam of the present invention, it is necessary to impart anisotropy to the resin foam by stretching either the batch method or the continuous method after passing through the above-described process or during the above-described process.

Specifically, it is preferable to extend by the following method.

For example, as shown in Fig. 3A, when a resin is extruded in a sheet shape from a slit T-die or a slit die 10, the resin sheet 11 is melted before the resin is cooled and solidified. Or put in the nip roll 12 in a semi-melted state, and pull it; As shown in FIG. 3B, when the resin is extruded from the slit-shaped T-die or the slit die 10 into a sheet shape, the resin sheet 11 is transferred to the roll 13 before the resin is cooled and solidified. How to stretch and pull; As shown in Fig. 3C, a method of pulling the resin sheet 11 over the roll 13 multiple times so that it does not slip; As shown in Fig. 3D, a method of biting and pulling between the rolls 13 so that the resin sheet 11 does not slip; As shown in Fig. 3E, a method of sandwiching the resin sheet 11 between the endless belts 14, bringing it into contact from both sides, and pulling it so that it does not slip by friction; As shown in FIG. 3F, a method of pulling by bringing into contact on the endless belt 14 so as not to slip due to friction between the belt and the resin sheet 11 is mentioned. In addition, as shown in G of Fig. 3, the resin sheet 11 was extruded from the cylindrical die 20 in a ring shape, and one of the ring shapes was cut with a cutter or the like and expanded into a sheet shape, For example, it may be inserted into the nip roll 12 and pulled out.

In the case of performing the above-described method, if the speed at which the resin sheet is sent by the roll or belt is defined as the molding speed, in order to form an anisotropic structure, the ratio of the extrusion speed of the resin and the molding speed is 1:1.2 to 1 It is preferable to set it as :5. By setting it as this range, it becomes possible to make a bubble shape into an elongate shape suitably, without being crushed in the thickness direction of a resin sheet, and porosity, cushioning property, and flexibility can be ensured.

In addition, the molding speed is not particularly limited, and in consideration of stably molding the resin sheet and production efficiency, it is preferable to set it in the range of 2 m/min to 100 m/min.

Further, in the case of biting the resin sheet with a roll or a belt, it is preferable to apply pressure so that the formed foam is not damaged in the thickness direction.

The amount of gas mixture when foaming or molding the resin composition is not particularly limited. For example, with respect to the total amount of the resin component in the resin composition, preferably 2 to 10% by weight, more preferably 2.5 to 8% by weight, and further It is more preferably 3 to 6% by weight. By setting it as this range, a foam having a high foaming rate can be obtained without separating the gas in the molding machine.

The pressure at the time of impregnating the gas into the unfoamed resin molded body or resin composition in the gas impregnation step in the batch method or the kneading impregnation step in the continuous method when foaming or molding the resin composition is determined by the type and operability of the gas. Although it can be appropriately selected in consideration of the like, for example, when an inert gas is used as a gas, particularly carbon dioxide, preferably 6 MPa or more (eg 6 to 100 MPa), more preferably 8 MPa or more (For example, 8 to 100 MPa). By setting it to such a pressure, bubble growth during foaming can be appropriately controlled, the cell diameter can be reduced, and further, a good dustproof effect can be provided. This is because the impregnation amount of the gas becomes an appropriate amount, the bubble nucleus formation rate is controlled, and the number of bubble nuclei formed can be adjusted to an appropriate number. In addition, control of the cell diameter and cell density becomes easy.

In the gas impregnation step in the batch method when foaming or molding the resin composition, or the kneading impregnation step in the continuous method, the temperature when impregnating the unfoamed resin molded body or the resin composition with a high-pressure gas is the gas to be used. Alternatively, depending on the type of resin, etc., it can be selected from a wide range. When operability or the like is considered, it is, for example, 10 to 350°C. In the batch method, when impregnating a sheet-shaped unfoamed resin molded body with a high-pressure gas, the impregnation temperature is preferably 10 to 250°C, more preferably 40 to 240°C, and preferably 60 to 230°C. to be. Further, in the continuous mode, the temperature at the time of injecting and kneading a high-pressure gas into the resin composition is preferably 60 to 350°C, more preferably 100 to 320°C, and preferably 150 to 300°C. When carbon dioxide is used as a high-pressure gas, in order to maintain a supercritical state, the temperature at the time of impregnation (impregnation temperature) is preferably 32°C or higher (particularly 40°C or higher).

The depressurization rate in the decompression step when foaming or molding the resin composition in a batch method or a continuous method is not particularly limited, and in order to obtain uniform fine bubbles, it is preferably 5 to 300 MPa/sec. The heating temperature in the heating step is, for example, 40 to 250°C (preferably 60 to 250°C).

When the above method is used when the resin composition is foamed or molded, a highly foamed resin foam can be produced, and a thick resin foam can be produced. For example, in the case of foaming or molding the resin composition in a continuous manner, in order to maintain the pressure inside the extruder in the kneading and impregnation process, the gap of the die installed at the tip of the extruder is made as narrow as possible (usually about 0.1 to 1.0 mm). ) do. Therefore, in order to obtain a thick resin foam, the resin composition extruded through a narrow gap is foamed at a high magnification. Conventionally, the thickness of the formed resin foam was limited to a thin one (for example, 0.5 to 2.0 mm) from the point of not obtaining a high expansion ratio. On the other hand, by foaming or molding the resin composition using a high-pressure gas, it is possible to continuously obtain a resin foam having a thickness of 0.50 to 5.00 mm.

Depending on its properties, such as apparent density, breaking strength, breaking elongation, cell size, hand cutability, gas used, thermoplastic resin, rubber component and/or thermoplastic elastomer component, for example, gas impregnation process Or operating conditions such as temperature, pressure, time in the kneading and impregnation process, the decompression rate in the decompression process or the raw molding decompression process, operating conditions such as temperature, pressure, and the heating temperature in the heating process after decompression or molding decompression. It can also be adjusted by appropriate selection and setting.

In particular, the resin foam of the present invention is formed by impregnating a resin composition containing at least a nucleating agent and an aliphatic compound in addition to a thermoplastic resin with a high-pressure gas (especially an inert gas) and then depressurizing the resin composition. It is desirable to be. Thereby, it has a cell structure with a small average cell diameter, a low closed cell structure rate, a high foaming ratio, has good flexibility, a cell structure is difficult to deform or compress, and is excellent in distortion recovery when pressed, A resin foam having excellent processability can be easily obtained.

In the resin foam of the present invention, in addition to the thermoplastic resin, after impregnating a resin composition containing at least a nucleating agent and an aliphatic compound having a particularly small average particle diameter with an inert gas in a supercritical state, the resin composition is depressurized, and the obtained resin It is more preferable that it is formed through the process of extending|stretching a foam. Thereby, the average cell diameter is very small, has a cell structure with a low closed cell structure rate, has a high foaming ratio, has good flexibility, the cell structure is difficult to deform or compress, and is excellent in distortion recovery when pressed. , Since the nucleating agent can be more suppressed from piercing the cell wall, and the anisotropy is very high, a resin foam having more excellent workability can be easily obtained.

The resin foam of the present invention is a mixture of a thermoplastic resin and a rubber component and/or a thermoplastic elastomer component, and in addition to the thermoplastic resin having a ratio of 70/30 to 30/70 by weight, 100 parts by weight of the thermoplastic resin After impregnating a resin composition containing at least 0.5 to 150 parts by weight of a nucleating agent and 1 to 5 parts by weight of an aliphatic compound based on 100 parts by weight of the thermoplastic resin, a step of impregnating a high pressure gas (especially an inert gas), It is preferable that it is formed through.

〔Expand seal material〕

The foamed sealing material of the present invention is a member containing the resin foam. The shape of the foam sealing material is not particularly limited, but a sheet shape (including a film shape) is preferable. The foamed sealing material may be, for example, a configuration including only a resin foam, or may be a configuration in which a pressure-sensitive adhesive layer, a substrate layer, and the like are laminated on the resin foam.

In particular, it is preferable that the foam sealing material of the present invention has an adhesive layer. For example, when the foam sealing material of the present invention is a sheet-shaped foam sealing material, you may have an adhesive layer on one or both sides thereof. If the foamed sealing material has an adhesive layer, for example, a substrate for processing can be provided on the foamed sealing material through an adhesive layer, and further, fixed to an adherend, temporary fixing, and the like can be performed.

The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is not particularly limited, and for example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive (natural rubber-based pressure-sensitive adhesive, synthetic rubber-based pressure-sensitive adhesive, etc.), a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a polyamide-based pressure-sensitive adhesive, an epoxy-based Known pressure-sensitive adhesives, such as an adhesive, a vinyl alkyl ether-based adhesive, and a fluorine-based adhesive, can be appropriately selected and used. The adhesive can be used alone or in combination of two or more. Further, the pressure-sensitive adhesive may be any type of pressure-sensitive adhesive, such as an emulsion-based pressure-sensitive adhesive, a solvent-based pressure-sensitive adhesive, a hot melt-type pressure-sensitive adhesive, an oligomer-based pressure-sensitive adhesive, and a solid-type pressure-sensitive adhesive. Among them, as the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of preventing contamination of an adherend.

The thickness of the adhesive layer is preferably 2 to 100 μm, more preferably 10 to 100 μm. The thinner the adhesive layer is, the higher the effect of preventing the adhesion of dust and dirt at the end, so the thinner the thickness is preferable.

The pressure-sensitive adhesive layer may have either a single layer or a laminated body, and may be either foamable or non-foamable. Among them, a non-foaming adhesive layer is preferable.

In the foam sealing material of the present invention, the adhesive material layer may be provided through another layer (lower layer). As such an underlayer, another adhesive material layer, an intermediate layer, an undercoat layer, a base layer (especially a film layer, a nonwoven fabric layer, etc.) etc. are mentioned, for example. Although the lower layer may be a foamable layer or a porous layer, it is preferable that it is a non-foamable layer, and it is more preferable that it is a resin layer.

The adhesive layer may be protected by a release film (separator, for example, a release paper, a release film, etc.).

Since the foamed sealing material of the present invention contains the resin foam of the present invention, it has good dustproofing properties, particularly good dynamic dustproofing properties, and has flexibility that can be traced to minute clearances.

The foam sealing material of the present invention may be processed to have a desired shape, thickness, or the like. For example, processing may be performed in various shapes according to the devices, devices, housings, members, etc. to be used.

The foam sealing material of the present invention is suitably used as a member used when various members or parts are installed (mounted) at a predetermined site. In particular, the foam sealing material of the present invention is suitable as a member used when installing (mounting) parts constituting an electric or electronic device in a predetermined portion in an electric or electronic device.

It does not specifically limit as various members or parts which can be installed or attached using a foam member, For example, various members or parts etc. in electric or electronic equipment are mentioned. As such a member or component for an electric or electronic device, for example, an image display member (display portion) mounted on an image display device such as a liquid crystal display, an electroluminescence display, and a plasma display (especially, a small image display member), so-called Optical members or optical parts, such as cameras and lenses (especially small cameras and lenses) mounted on mobile communication devices such as "mobile phone" and "portable information terminal", may be mentioned.

As a suitable specific form of use of the foam sealing material of the present invention, for the purpose of, for example, dustproof, light shielding, buffering, etc., around a display portion such as an LCD (liquid crystal display), between a display portion such as an LCD (liquid crystal display) and a housing (window) It can be inserted into and used.

When the foam sealing material of the present invention is installed on such a member or part, it is preferable to install it so as to prevent the clearance, and this clearance is not particularly limited, for example, about 0.05 to 0.5 mm. .

Hereinafter, the thermoplastic resin foam and foam sealing material of the present invention will be described based on Examples.

(Example 1)

As a resin composition,

35 parts by weight of polypropylene,

60 parts by weight of a thermoplastic elastomer composition,

5 parts by weight of lubricant,

10 parts by weight of a nucleating agent and

2 parts by weight of erucic acid amide (melting point 80 to 85°C) was kneaded at a temperature of 200°C with a twin-screw kneader.

Here, the polypropylene is a resin having a melt flow rate (MFR) of 0.35 g/10 min,

The thermoplastic elastomer composition contains 16.7% by weight of carbon black, and is a blend of polypropylene (PP) and ethylene/propylene/5-ethylidene-2-norbornene terpolymer (EPT) (crosslinked olefin-based thermoplastic Elastomer, TPV), polypropylene: ethylene/propylene/5-ethylidene-2-norbornene terpolymer = 10:90 (by weight),

The lubricant is a master batch in which 10 parts by weight of polyethylene is mixed with 1 part by weight of monoglyceride stearate,

The nucleating agent is magnesium hydroxide having an average particle diameter of 0.8 µm.

Thereafter, the resin composition was extruded into a strand shape, cooled with water, and cut into a pellet shape to be molded.

This pellet was put into a tandem single screw extruder manufactured by Nippon Sekosho Co., Ltd., and 3.8% by weight of carbon dioxide gas was injected at a pressure of 14 (18 MPa after injection) in an atmosphere of 220°C. The carbon dioxide gas was sufficiently saturated and cooled to a temperature suitable for foaming. After that, in order to extrude from the die to obtain an anisotropic structure, the ratio of the extrusion speed and the molding speed of the resin is adjusted to be in the range of 1:1.2 to 1:2, so that the foam does not become loose in the line, and the thickness is 1 mm. It adjusted so that it might become, and the sheet-shaped resin foam was obtained. This resin foam had a semi-continuous semi-independent cell structure having a tensile modulus of 9.3 MPa and a closed cell ratio of 32%.

(Example 2)

A sheet-shaped resin foam was produced substantially in the same manner as in Example 1 except that the thickness was adjusted to 0.5 mm. This resin foam had a semi-continuous semi-independent cell structure with a closed cell ratio of 32%. The ductility at 0.5N was 3.7%, and the ductility at 1.0N was 7.2%.

(Comparative Example 1)

As an isotropic foam, a urethane foam (main component: polyurethane, sheet shape, average cell diameter: 229 μm, apparent density: 0.24 g/cm 3) was prepared.

(Measurement method of independent bubble rate)

The closed cell ratio of the resin foam obtained in Examples and Comparative Examples was measured according to the following method.

From the obtained resin foam, a flat square test piece having a side of 5 cm at a constant thickness is cut out. Subsequently, the weight W1 (g) and thickness (cm) of the test piece are measured, and the apparent volume V1 (cm 3) of the test piece is calculated.

Subsequently, the obtained value is substituted into the equation (1) to calculate the apparent volume V2 (cm 3) occupied by the bubbles. In addition, the density of the resin constituting the test piece is set to ρg/cm3.

(1)

(One)

Subsequently, this test piece is immersed in distilled water at 23°C so that the distance from the top surface of the test piece to the water surface becomes 40 mm, and left to stand for 24 hours. After that, the test piece is taken out in distilled water, and moisture adhering to the surface of the test piece is removed. The weight W2 (g) of the obtained test piece is measured, and the continuous bubble ratio F1 is calculated based on the formula (2). The closed cell ratio F2 is determined from this continuous cell ratio F1.

(2)

(2)

(3)

(3)

(Tensile modulus)

A tensile test in accordance with JIS K 6767 was performed, and the obtained stress distortion line was calculated based on the following equation by the inclination under the elastic region. That is, under the elastic region in the stress distortion line, it was determined by the ratio of the stress and the corresponding distortion.

Tensile modulus (㎫) = stress/distortion

(Softness)

A. Flexibility (0.5N)

The resin foam was cut out in the MD direction, and a sheet-shaped test piece having a thickness of 0.5 mm, a width of 3 mm and a length of 30 mm was produced. With the one end of the test piece fixed in the longitudinal direction, the test piece was stretched in the longitudinal direction under a load of 0.5 N, and the length of the test piece after stretching was measured. Based on the following equation, the softness (%) was calculated.

Softness (%) = 100 × [(length of test piece after stretching)-(length of initial test piece)]/(length of initial test piece)

If the softness (0.5N) is 5.0% or less, it is difficult to extend and can be judged to be good.

B. Softness (1.0N)

The ductility (%) was calculated similarly to the ductility (0.5N) except that the load was 1.0N.

When the softness (1.0N) is 10.0% or less, it is difficult to extend and can be judged to be good.

(evaluation)

The following evaluation was performed about the sheet|seat of the resin foam of an Example and a comparative example. The results are shown in Table 1.

(Measurement method of apparent density)

Using a sample cut out of the resin foam into 20 mm x 20 mm, the apparent density (g/cm 3) of the foam was calculated from the weight and buoyancy of the sample with a density meter.

(Measurement method of maximum breaking strength Smax and breaking strength Smin/breaking elongation SSmax and SSmin)

First, the resin foam measures the breaking strength in an arbitrary direction (e.g., direction A), further sets a center X on the axis of the direction A, and rotates the axis by 10° with respect to this center X, The breaking strength in each direction indicated by each axis was measured (a total of 18 directions). Among them, the breaking strength in the direction having the largest breaking strength was selected, and this was referred to as the maximum breaking strength Smax.

In addition, in the resin foam of Examples, the direction in which the maximum breaking strength Smax was indicated coincided with the MD direction. Therefore, the direction orthogonal to the direction representing the maximum breaking strength coincides with the TD direction.

As for the breaking strength, a resin foam was drilled through a dumbbell No. 1, and a tensile test was conducted at a distance of 50 mm between the chucks and a tensile speed of 500 mm/min. And the breaking strength and breaking elongation, respectively.

(Measurement method of bubble size)

In parallel to the direction of the maximum breaking strength to be described later of the resin foam and a direction orthogonal to this direction, each of the main surfaces of the resin foam was cut in a vertical direction (thickness direction) with a cutter to prepare a smooth cross section.

These cross sections were introduced into a Keyence microscope (for example, a brand name "VHX-600" manufactured by Keyence Corporation), and image analysis was performed using the analysis software (Mitani Shoji Co., Ltd. product: Win ROOF) of this measuring instrument. Within the measurement range of the resin foam 3000 µm x 2500 µm, the diameter was converted from the pixel area of the image and measured as the cell diameter, and 10 points were extracted from those having a large cell diameter, and the average was calculated, and this was called the cell size. .

(Hand cutting property)

As shown in Fig. 1, sample 1 having a width of 40 mm and a length of 100 mm was prepared, and a cutout 1a was formed in the sample 1 from a position of 20 mm in width to 50 mm in parallel with the length direction. As shown in Fig. 2, after fixing the sample 1 to the gripping part 2 of the tensile testing machine, at a tensile speed of 500 mm/min, the sample 1 was pulled in the Z direction until it broke and separated, and sample 1 The linear cutability of was judged by the naked eye. When the position deviation (Q in FIG. 1) from the cut-out position to the fractured end was within 5 mm (20%), the hand-cutting property was evaluated as good.

According to Table 1, it was confirmed that the resin foams of Examples 1 and 2 had a large value of Smax/Smin, and had remarkable anisotropy against shear fracture in a specific direction, and thus, good processability could be realized.

The present invention is useful as a heat insulating material, food packaging material, clothing material, building material, internal insulators for electronic devices, cushioning material, sound insulation material, vibration isolating material, shock absorber, light shielding material, etc., has excellent flexibility, cushioning and processability, and has a high foaming ratio It is a resin foam and a foam sealing material, and can be widely used for various members.

1: sample
2: gripping part
10: T-die or slit die
11: resin sheet
12: nip roll
20: resin foam
21: roller

Claims (11)

It is a resin foam containing a thermoplastic resin,
The maximum breaking strength Smax of the foam is 0.1 MPa to 3 MPa, and
The resin foam, wherein the ratio Smax/Smin of the maximum breaking strength Smax and the breaking strength Smin in a direction orthogonal to the direction representing the maximum breaking strength is 1.5 to 6. The method of claim 1,
The breaking elongation SSmax in the direction representing the maximum breaking strength is 200% or less,
A resin foam in which the breaking elongation SSmax in the direction showing the maximum breaking strength and the breaking elongation ratio SSmax/SSmin in the direction orthogonal to the direction showing the maximum breaking strength are 1.5 to 6. The method according to claim 1 or 2,
A resin foam in which the ratio Cmax/Cmin of the cell size Cmax in the direction showing the maximum breaking strength and the cell size Cmin in a direction orthogonal to the direction showing the maximum breaking strength is 1.2 to 5. The method according to claim 1 or 2,
A resin foam having an apparent density of 0.01 to 0.2 g/cm 3. The method according to claim 1 or 2,
A thermoplastic resin foam obtained by depressurizing a thermoplastic resin composition impregnated with a high-pressure gas. The method of claim 5,
A resin foam in which the gas is an inert gas. The method of claim 6,
The resin foam in which the inert gas is carbon dioxide or nitrogen. The method of claim 5,
The resin foam wherein the gas is a gas in a supercritical state. Foam sealing material comprising the resin foam according to claim 1 or 2. The method of claim 9,
Foam sealing material having an adhesive layer disposed on one or both sides of the foam. The method of claim 10,
Foam sealing material in which an adhesive layer is arranged on the surface of a resin foam through a film layer.

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