TW201406835A - Resin foam, foam member, foam member laminate, and electric or electronic devices - Google Patents

Abstract

Provided is a resin foam having a fine cell structure, being capable of suppressing or preventing foam destruction when peeling same from a carrier tape even if same is a flexible resin foam, and having excellent workability and transport properties when being held by the carrier tape. This resin foam is characterized by: having an interlayer peeling strength, as defined, of at least 10 N/20 mm; having a repulsive force at 50% compression of 0.1-4.0 N/cm2; having an average cell diameter of 10-200 [mu]m; and having a maximum cell diameter of no more than 300 [mu]m. Interlayer peeling strength: The peeling strength when a sheet-shaped resin foam is pasted to an adhesive surface of an adhesive tape (product name "No. 5603", manufactured by Nitto Denko Corporation) in an atmosphere of 23 DEG C, the resin foam is compressed under the conditions of one reciprocal movement by a 2 kg roller, and the resin foam is peeled from the adhesive tape under conditions of a peeling angle of 90 DEG and a peeling speed of 0.3 m/min.

Description

Resin foam, foam member, foam member laminate, and electrical or electronic equipment

The present invention relates to a resin foam, a foam member, a foam member laminate, and an electric or electronic device. More specifically, the present invention relates to an electrical or electronic device (eg, a mobile phone, a mobile terminal, a smart phone, a tablet (tablet PC), a digital camera, a video camera, a digital video camera, a personal computer, home appliances, etc.) A resin foam used in the present invention, a foamed member including the resin foam, a foamed member laminated body including the foamed member, and an electrical or electronic device including the foamed member.

The resin foam is usually punched in a desired shape in accordance with the shape of the member to be used, or the surface of the resin foam is subjected to adhesive processing so as to be easily fixed to the member, but such processing is carried out. Since the resin foam is not easy to handle, it is often used to carry it to a specific portion. In other words, the resin foaming system is subjected to various processes (such as punching or adhesion processing) in a state of being bonded to a carrier tape, or is conveyed after processing. On the other hand, after the processing, the resin foam must be peeled off from the carrier tape, and when the surface strength of the resin foam is low (weak), the resin foam may be damaged when peeled off. In particular, in the case of a resin foam having a high expansion ratio [for example, a thermoplastic resin foamed by a step of subjecting a high-pressure inert gas (for example, carbon dioxide in a supercritical state) to a thermoplastic resin and then performing a pressure reduction step. (see Patent Document 1), since the thickness of the bubble wall is thin, breakage at the time of peeling is likely to occur. In particular, if the resin foam contains coarse cells, the proportion of the bubble walls on the surface of the foam is reduced, making it easier Destruction occurs when peeling occurs.

Further, if a carrier tape having a smaller adhesive force is used in order to prevent breakage during peeling, there is a problem that dimensional deviation (shape stability) is lowered due to offset during processing, or self-processing is performed when assembling a foam member. The problem that the self-loading tape is peeled off before being peeled off by the liner paper and cannot be assembled.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-247706

Therefore, an object of the present invention is to provide a resin foam which can suppress or prevent the destruction of the bubble when the self-supporting tape is peeled off, and which is retained on the carrier tape even if it is a soft resin foam having a fine cell structure. It is excellent in workability and conveyability.

Further, another object of the present invention is to provide a foam member using the above resin foam, a foam member laminate using the foam member, and an electric or electronic device using the foam member.

Therefore, the inventors of the present invention have conducted an effort to find that when the interlaminar peeling strength is a specific value or more, the repulsive force at a compression of 50% is within a specific range, and the average cell diameter is set. When the maximum cell diameter is set to a specific value or less in a specific range, the fine cell structure is obtained, and excellent flexibility can be obtained, and the suppression of the bubble damage at the time of peeling off from the carrier tape can be obtained and maintained. Processability and transportability at the time of carrier tape. The present invention is based on such insights.

That is, the present invention provides a resin foam characterized in that the interlaminar peel strength defined below is 10 N/20 mm or more, and the rebound force at a compression of 50% is 0.1 to 4.0 N/cm ² , and the average cell diameter is 10~200μm, the maximum cell diameter is 300μm or less.

Interlaminar peeling strength: The sheet-like resin foam was attached to the adhesive surface of an adhesive tape (trade name "No. 5603", manufactured by Nitto Denko Corporation) at 23 ° C, and was transferred to a 2 kg roller. After the pressure bonding, the peeling strength of the resin foam at the peeling angle of 90° and a tensile speed of 0.3 m/min from the adhesive tape was peeled off.

The resin foam preferably further has an apparent density of 0.01 to 0.20 g/cm ³ .

The resin constituting the above resin foam is preferably a thermoplastic resin.

The above thermoplastic resin is preferably a polyester.

The resin foam is preferably formed by a step of impregnating a resin composition with a high-pressure gas and then reducing the pressure.

The above gas is preferably an inert gas.

The above gas is preferably carbon dioxide.

The high pressure gas is preferably in a supercritical state.

Furthermore, the present invention provides a foamed member comprising the above resin foam.

The foam member preferably contains a surface layer on the resin foam.

The surface layer is preferably a layer formed by heat-melting treatment of the surface of the resin foam.

The above surface layer is preferably an adhesive layer.

The above adhesive layer is preferably an acrylic adhesive layer.

The foaming member is preferably used for electrical or electronic equipment.

Further, the present invention provides a foamed member laminated body comprising a structure in which the foam member is held by a carrier tape including an adhesive layer on at least one side of the substrate.

Furthermore, the present invention provides an electric or electronic device comprising the above-described foam member.

Since the resin foam of the present invention has the above-described configuration, even if it is a soft resin foam having a fine cell structure, it is possible to suppress or prevent bubble breakage when the self-supporting tape is peeled off (cells in the foam) The structure is deteriorated, and the workability and the conveyability at the time of carrying the tape are excellent in the characteristics of the carrier tape.

In the resin foam of the present invention, the interlayer peel strength defined below is 10 N/20 mm or more, the rebound force at 50% compression is 0.1 to 4.0 N/cm ² , and the average cell diameter is 10 to 200 μm. The cell diameter is 300 μm or less.

Interlaminar peeling strength: The sheet-like resin foam was attached to the adhesive surface of an adhesive tape (trade name "No. 5603", manufactured by Nitto Denko Corporation) at 23 ° C, and was transferred to a 2 kg roller. After the pressure bonding, the peeling strength of the resin foam at the peeling angle of 90 (degrees) and a tensile speed of 0.3 m/min from the adhesive tape was peeled off.

Further, in the present specification, the interlayer peel strength defined above may be simply referred to as "interlayer peel strength".

The resin foaming system of the present invention is formed by foaming a composition (resin composition) containing at least a resin constituting the resin foam of the present invention. The resin composition preferably contains 70% by weight or more (preferably 80% by weight or more) based on the total amount of the resin composition (100% by weight).

The interlayer peel strength of the resin foam of the present invention is 10 N/20 mm or more, preferably 15 N/20 mm or more, and more preferably 20 N/20 mm or more. In the resin foam of the present invention, since the interlayer peeling strength is 10 N/20 mm or more, the foaming property at the time of peeling off from the carrier tape is excellent. For example, when carrying a resin foam, use a carrier tape temporarily. When the resin foam is fixed and transferred after the resin foam is fixed, it is difficult to cause breakage of the resin foam when the resin foam is peeled off from the carrier tape. Further, the upper limit of the interlayer peeling strength is not particularly limited, but is preferably 60 N/20 mm, more preferably 50 N/20 mm.

The rebound stress at 50% compression of the resin foam of the present invention is not particularly limited, but is preferably 0.1 to 4.0 N/cm ² , more preferably 0.3 to 3.5 N/cm ² , and still more preferably 0.5 to 3.0 N. /cm ² . In the resin foam of the present invention, when the rebound stress at 50% compression is 0.1 N/cm ² or more, it is preferable to obtain appropriate rigidity and to easily obtain good workability. Further, when the rebound stress at 50% compression is 4.0 N/cm ² or less, it is easy to obtain excellent flexibility, which is preferable.

The above-mentioned rebound stress at 50% compression means a compressive stress at a compression ratio of 50%. The compression ratio is 50%, which means that the sheet-like resin foam is compressed in the thickness direction to a height corresponding to 50% of the initial height, that is, it is compressed to a state of 50% from the initial thickness strain, and is compressed. The thickness of the sheet-like resin foam having a ratio of 50% corresponds to a thickness of 50% of the initial thickness.

The resin foam of the present invention has an average cell diameter of 10 to 200 μm, more preferably 15 to 150 μm, still more preferably 20 to 100 μm. In the resin foam of the present invention, since the average cell diameter is 10 μm or more, it has excellent flexibility. Moreover, since the average cell diameter is 200 μm or less, generation of voids can be suppressed, and excellent dust resistance can be obtained. Moreover, since the adhesion area to the carrier tape can be enlarged, the characteristics of the carrier tape are excellent.

The resin foam of the present invention has a maximum cell diameter of 300 μm or less, more preferably 250 μm or less, still more preferably 200 μm. In the resin foam of the present invention, since the maximum cell diameter is 300 μm or less, the cell structure is excellent in uniformity and does not contain coarse cells, so that the strength or the characteristics of the carrier tape are excellent. In addition to this, it is possible to suppress the problem that dust enters from the coarse cells and the dustproof property is lowered, so that the sealing property and the dustproof property are excellent.

The cell diameter in the cell structure of the resin foam of the present invention is obtained, for example, by obtaining a cell structure portion (bubble structure portion) of the cut surface by a digital microscope. The image is enlarged, the area of the cell is determined, and the diameter of the approximate circle is converted.

In the resin foam of the present invention, since the average cell diameter is 10 to 200 μm and the maximum cell diameter is 300 μm, it has a uniform and fine cell structure. Also, it does not contain coarse cells.

The cell structure of the resin foam of the present invention is not particularly limited, but is preferably a semi-continuous semi-closed cell structure (independent bubble structure and continuous cell structure) in terms of strength, sealing property, dust resistance, and flexibility. The ratio of the cell structure to be mixed is not particularly limited, and it is particularly preferable that the cell structure of the resin foam has a cell structure of 40% or less (preferably 30% or less).

The apparent density of the resin foam of the present invention is not particularly limited, but is preferably 0.01 to 0.20 g/cm ³ , more preferably 0.02 to 0.17 g/cm ³ , still more preferably 0.03 to 0.15 g/cm ³ . In the resin foam of the present invention, when the density is 0.01 g/cm ³ or more, good strength is easily obtained, which is preferable. Moreover, when the density is 0.20 g/cm ³ or less, a high expansion ratio is obtained and excellent flexibility is easily obtained, which is preferable. In other words, in the resin foam of the present invention, when the apparent density is 0.01 to 0.20 g/cm ³ , better foaming properties (high expansion ratio) can be obtained, so that it is easy to exhibit appropriate strength and excellent properties. Softness and excellent cushioning properties.

The shape of the resin foam of the present invention is not particularly limited, but is preferably a sheet shape or a belt shape. Moreover, it can also be processed into an appropriate shape according to the purpose of use. For example, it may be processed into a linear shape, a circular shape or a polygonal shape, a frame shape (frame shape), or the like by cutting, punching, or the like.

The thickness of the resin foam of the present invention is not particularly limited, but is preferably 0.05 to 3.0 mm, more preferably 0.06 to 2.8 mm, still more preferably 0.07 to 1.5 mm, and still more preferably 0.08 to 1.0 mm.

The resin which is a raw material of the resin foam of the present invention is not particularly limited, and a thermoplastic resin is preferably used. The resin foam of the present invention may be composed of only one resin The composition may be composed of two or more kinds of resins.

Examples of the thermoplastic resin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, a copolymer of ethylene and propylene, ethylene or propylene and other α-olefins (for example). a copolymer of butene-1, pentene-1, hexene-1, 4-methylpentene-1, etc., ethylene and other ethylenically unsaturated monomers (for example, vinyl acetate, acrylic acid, acrylate) a polyolefin resin such as a copolymer of methacrylic acid, methacrylic acid ester or vinyl alcohol; styrene such as polystyrene or acrylonitrile-butadiene-styrene copolymer (ABS (Acrylonitrile Butadiene Styrene) resin) Resin; 6-nylon, 66-nylon, 12-nylon and other polyamine resin; polyamidoquinone; polyurethane; polyimine; polyether quinone; polymethacrylic acid Acrylic resin such as methyl ester; polyvinyl chloride; polyvinyl fluoride; alkenyl aromatic resin; polyester resin such as polyethylene terephthalate or polybutylene terephthalate; bisphenol A polycarbonate Polycarbonate such as ester; polyacetal; polyphenylene sulfide. Further, the thermoplastic resin may be used singly or in combination of two or more. Further, when the thermoplastic resin is a copolymer, it may be a copolymer of any of a random copolymer and a block copolymer.

The thermoplastic resin also contains a rubber component and/or a thermoplastic elastomer component. Since the rubber component or the thermoplastic elastomer component is at room temperature or lower (for example, 20° C. or lower), the flexibility and shape followability of the resin foam are remarkably excellent. Further, the resin foaming system of the present invention may be formed of a resin composition containing the above thermoplastic resin and a rubber component and/or a thermoplastic elastomer component.

The rubber component or the thermoplastic elastomer component is not particularly limited as long as it has rubber elasticity and can be foamed, and examples thereof include natural rubber, polyisobutylene, polyisoprene, chloroprene rubber, and butyl rubber. Natural or synthetic rubber such as nitrile rubber; olefin-based elastomer such as ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, polybutene, chlorinated polyethylene; Styrene-based elastomers such as butadiene-styrene copolymers, styrene-isoprene-styrene copolymers and their hydrides Various thermoplastic elastomers such as polyester elastomers; polyamine elastomers; polyurethane elastomers. In addition, these rubber components or thermoplastic elastomer components may be used alone or in combination of two or more.

As the thermoplastic resin, an interlayer peel strength of a specific value or more, a rebound force at a compression of 50% in a specific range, an average cell diameter in a specific range, and a maximum cell diameter of a specific value or less are obtained, even if there are fine cells. The structure is soft, and the foam damage inhibition property at the time of peeling off from the carrier tape and the workability and transportability at the time of carrier tape are excellent at the level of the carrier tape, and polyester is preferable. The polyester such as the polyester resin or the polyester elastomer is more preferably a polyester elastomer. In other words, the resin foam of the present invention is more preferably a resin foam (polyester elastomer foam) formed of a resin composition containing a polyester elastomer.

The polyester-based elastomer is not particularly limited as long as it is a resin having an ester bond site formed by a reaction (polycondensation) of a polyol component and a polycarboxylic acid component, and examples thereof include an aromatic dicarboxylic acid (II). A polyester-based thermoplastic resin obtained by polycondensation of a valence aromatic carboxylic acid) and a diol component.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, and naphthalenecarboxylic acid (for example, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, etc.). Diphenyl ether dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and the like. Further, the aromatic dicarboxylic acid system may be used singly or in combination of two or more kinds.

Further, examples of the diol component include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, and 1,5- Pentandiol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl- 2,4-pentanediol, 1,7-heptanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl -1,6-hexanediol, 1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,3,5-trimethyl-1,3-pentanediol 1,9-nonanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,10-nonanediol, 2-methyl -1,9-nonanediol, An aliphatic diol such as 1,18-octadecanediol or a dimer; 1,4-cyclohexanediol, 1,3-cyclohexanediol, 1,2-cyclohexanediol, 1,4- An alicyclic diol such as cyclohexane dimethanol, 1,3-cyclohexane dimethanol or 1,2-cyclohexane dimethanol; bisphenol A, an ethylene oxide adduct of bisphenol A, bisphenol S, an ethylene oxide adduct of bisphenol S, an aromatic diol such as benzene dimethyl glycol or naphthalene diol; diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, A diol component such as an ether diol such as dipropylene glycol. Further, the diol component may be a diol component in a polymer form such as a polyether diol or a polyester diol. Examples of the polyether diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, which are subjected to ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, and the like, and copolyethers obtained by copolymerizing the same. Polyether glycol and the like. Further, the diol component may be used singly or in combination of two or more.

Examples of the polyester-based thermoplastic resin include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polynaphthalene dicarboxylic acid. A polyalkylene terephthalate resin such as butadiene ester or polycyclohexane terephthalate. Further, a copolymer obtained by copolymerizing two or more kinds of the above polyalkylene terephthalate resins may be used. Further, when the polyalkylene terephthalate resin is a copolymer, it may be a copolymer of any of a random copolymer, a block copolymer, and a graft copolymer.

Further, examples of the polyester-based elastomer include a polyester-based elastomer which is a block copolymer of a hard segment and a soft segment.

Examples of the polyester-based elastomer (the polyester-based elastomer which is a block copolymer of a hard segment and a soft segment) include (i) a hydroxyl group in the above aromatic dicarboxylic acid and the above-mentioned diol component. A polyester formed by polycondensation of a diol component having a carbon number of 2 to 4 in a main chain with a hydroxyl group is a hard segment and a hydroxyl group and a hydroxyl group in the above aromatic dicarboxylic acid and the above diol component a polyester formed by polycondensation of a diol component having a carbon number of 5 or more in the main chain is a polyester/polyester copolymer of a soft segment; (ii) and (i) above Copolymerization of polyester ‧ polyether type in which the same polyester is set as a hard segment and the polyether such as polyether diol is set as a soft segment (iii) a polyester ‧ polyester type copolymer in which the polyesters similar to the above (i) and (ii) are hard segments and the aliphatic polyester is a soft segment.

In particular, when the resin foam of the present invention is a polyester elastomer foam, the polyester elastomer to be formed is preferably a block copolymer of a hard segment and a soft segment. a polyester elastomer, more preferably a polyester ‧ polyether copolymer of the above (ii) (a diol having a carbon number of 2 to 4 in the main chain between the aromatic dicarboxylic acid and the hydroxyl group and the hydroxyl group) The polyester formed by the polycondensation of the component is a hard segment and the polyether is a soft segment of the polyester ‧ polyether copolymer).

The polyester ‧ polyether type copolymer of the above (ii), more specifically, a polyester ‧ polyether having a polybutylene terephthalate as a hard segment and a polyether as a soft segment Type block copolymer and the like.

The melt flow rate (MFR, Melt Flow Rate) of the resin constituting the resin foam of the present invention at 230 ° C is not particularly limited, but is preferably 1.5 to 4.0 g/10 min, more preferably 1.5 to 3.8 g/10 min. Further preferably, it is 1.5 to 3.5 g/10 min. When the melt flow rate (MFR) of the resin at 230 ° C is 1.5 g/10 min or more, the formability of the resin composition used in forming the resin foam of the present invention is improved, which is preferable. Further, when the melt flow rate (MFR) of the resin at 230 ° C is 4.0 g/10 min or less, it is difficult to cause a variation in the cell diameter after the formation of the cell structure, and it is easy to obtain a uniform cell structure, which is preferable. In the present specification, the MFR at 230 ° C means the MFR measured at a temperature of 230 ° C and a load of 2.16 kgf based on ISO 1133 (JIS K 7210).

That is, the resin foam of the present invention is preferably formed of a resin composition containing a resin having a melt flow rate (MFR) of from 230 to 4.0 g/10 min at 230 °C. In particular, in the case where the resin foam of the present invention is a polyester elastomer foam, it is preferred to have a polyester-based elasticity containing a melt flow rate (MFR) at 230 ° C of 1.5 to 4.0 g/10 min. A resin composition of a body (especially a polyester elastomer which is a block copolymer of a hard segment and a soft segment).

The resin composition forming the resin foam of the present invention preferably contains a foaming nucleating agent in addition to the above resin. When the resin composition contains a foaming nucleating agent, it is easy to obtain a resin foam having a good foaming state. Further, the foaming nucleating agent may be used singly or in combination of two or more.

The foaming nucleating agent is not particularly limited, and an inorganic material can be preferably used. Examples of the inorganic substance include hydroxides such as aluminum hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide; clay (especially hard clay); talc; cerium oxide; zeolite; for example, calcium carbonate and magnesium carbonate. An alkaline earth metal carbonate; for example, a metal oxide such as zinc oxide, titanium oxide or aluminum oxide; for example, various metal powders such as iron powder, copper powder, aluminum powder, nickel powder, zinc powder, titanium powder, alloy powder, etc. Metal powder; mica; carbon particles; glass fiber; carbon tube; layered niobate; glass.

Among them, as the inorganic substance as the foaming nucleating agent, the generation of coarse cells is suppressed, and a uniform and fine cell structure can be easily obtained, and clay, alkaline earth metal carbonate, and more preferably hard clay are preferable. .

The above hard clay system contains almost no clay of coarse particles. In particular, the hard clay is preferably a clay having a mesh residue of 0.01% or less of 0.01%, more preferably 0.001% or less of clay having a mesh residue of 0.001% or less. Further, the sieve residue (sieve residue) is a ratio (weight basis) of the residue to the whole when it is sieved by a sieve.

The hard clay is composed of alumina and cerium oxide as essential components. The total ratio of the alumina and the cerium oxide in the hard clay is preferably 80% by weight or more (for example, 80 to 100% by weight), more preferably 90% by weight or more based on the total amount of the hard clay (100% by weight). (for example, 90 to 100% by weight). Further, the hard clay may be calcined.

The average grain diameter of the hard clay is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.2 to 5.0 μm, still more preferably 0.5 to 1.0 μm.

Further, the inorganic material is preferably subjected to surface processing. That is, the foaming nucleating agent is preferably a surface-treated inorganic substance. Surface treatment used as a surface treatment for inorganic materials The agent is not particularly limited, and the affinity with a resin (especially polyester) is improved by performing a surface treatment, and voids are not generated during foaming, molding, kneading, stretching, and the like. In view of the effect of not breaking the cells at the time of foaming, an aluminum compound, a decane compound, a titanate compound, an epoxy compound, an isocyanate compound, a higher fatty acid or a salt thereof and preferably As the phosphate ester, a decane-based compound (especially a decane coupling agent), a higher fatty acid or a salt thereof (especially stearic acid) can be more preferably exemplified. In addition, the surface treatment agent may be used alone or in combination of two or more.

That is, the surface treatment of the above inorganic substance is preferably a decane coupling treatment or a treatment using a higher fatty acid or a salt thereof.

The aluminum compound is not particularly limited, and is preferably an aluminum coupling agent. Examples of the aluminum-based coupling agent include aluminum acetaloxydiisopropylate, aluminum ethoxide, aluminum isopropoxide, aluminum mono-t-butoxydiisopropylate, aluminum second butoxide, and acetamidine. Ethyl acetate diisopropoxide aluminum, tris(acetonitrile ethyl acetate) aluminum, monoethyl acetonacetone bis(acetonitrile ethyl acetate) aluminum, tris(acetonitrile)aluminum, isopropyl acid cycloaluminum oxide (Cyclic Aluminum Oxide Isopropylate), Cyclic Aluminum Oxide Isostearate, and the like.

The decane-based compound is not particularly limited, and is preferably a decane-based coupling agent. Examples of the decane-based coupling agent include a vinyl-containing decane-based coupling agent, a (meth)acryl-based decane-based coupling agent, an amine-containing decane-based coupling agent, and an epoxy group-containing decane-based coupling agent. A mixture, a decane-based coupling agent containing a mercapto group, a decane-based coupling agent containing a carboxyl group, a decane-based coupling agent containing a halogen atom, and the like. Specific examples of the decane coupling agent include vinyl trimethoxy decane, vinyl ethoxy decane, dimethyl vinyl methoxy decane, dimethyl vinyl ethoxy decane, and methyl ethylene. Dimethoxy decane, methyl vinyl diethoxy decane, vinyl tris(2-methoxy) decane, vinyl triethoxy decane, 2-methyl propylene methoxyethyl three Ethoxy decane, 3-methacryloxypropyltrimethoxydecane, 3-methylpropenyloxypropyltriethoxydecane, 3- Methyl propylene methoxy-propyl methyl dimethoxy decane, 3-aminopropyl trimethoxy decane, 3-aminopropyl triethoxy decane, 2-aminoethyl trimethoxy decane 3-[N-(2-Aminoethyl)amino]propyltrimethoxydecane, 3-[N-(2-aminoethyl)amino]propyltriethoxydecane, 2- [N-(2-Aminoethyl)amino]ethyltrimethoxydecane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 2-(3,4-epoxy ring Hexyl)ethyltriethoxydecane, 3-glycidoxy-propyltrimethoxydecane, 3-glycidoxy-propylmethyldiethoxydecane, 2-glycidoxy-ethyl Trimethoxydecane, 2-glycidoxy-ethyltriethoxydecane, 3-mercaptopropyltrimethoxydecane, carboxymethyltriethoxydecane, 3-carboxypropyltrimethoxydecane, 3 -Carboxypropyltriethoxydecane, and the like.

The titanate-based compound is not particularly limited, and is preferably a titanate-based coupling agent. Examples of the titanate coupling agent include isopropyl triisostearate isopropyl titanate, isopropyl tris(dioctylpyrophosphonium oxy)titanate, and tris(N-aminoethyl- Isopropyl ethyl) isopropyl titanate, isopropyl tridecyl benzene sulfonyl titanate, tetraisopropyl bis(dioctylphosphonium oxy) titanate, tetraoctyl bis (two) -tridecylphosphonium oxy) titanate, tetrakis(2,2-diallyloxymethyl-1-butyl)bis(di-tridecyl)phosphite-titoxytitanate Ester, bis(dioctylpyridiniumoxy)glycolic acid titanate, bis(dioctylpyridiniumoxy)ethene titanate, trioctylphosphonium titanate, dimethyl methacrylate Isopropyl stearyl phthalate, isopropyl isostearyl bis propylene methacrylate, isopropyl tris(dioctylphosphonium oxy) titanate, triisopropylphenyl phenyl titanic acid Isopropyl ester, dicumylphenyl hydroxyglycolate titanate, diisostearate vinyl titanate, and the like.

The epoxy compound is not particularly limited, and is preferably an epoxy resin or a monoepoxy compound. Examples of the epoxy resin include a glycidyl ether epoxy resin such as a bisphenol A epoxy resin, a glycidyl ester epoxy resin, a glycidylamine epoxy resin, and an alicyclic epoxy resin. . Further, examples of the monoepoxy compound include styrene oxide, glycidyl phenyl ether, allyl glycidyl ether, glycidyl (meth)acrylate, and 1,2-epoxycyclohexane. , epichlorohydrin, deglycerin, etc.

The isocyanate compound is not particularly limited, and is preferably a polyisocyanate compound or a monoisocyanate compound. Examples of the polyisocyanate-based compound include aliphatic diisocyanates such as tetramethylene diisocyanate and hexamethylene diisocyanate; and alicyclic groups such as isophorone diisocyanate and 4,4′-dicyclohexylmethane diisocyanate; Diisocyanate; diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, benzene dimethylene diisocyanate, tolyl An aromatic diisocyanate such as a diisocyanate; a polymer having a free isocyanate group formed by the reaction of the diisocyanate compound and a polyol compound. Further, examples of the monoisocyanate compound include phenyl isocyanate and stearyl isocyanate.

Examples of the higher fatty acid or a salt thereof include higher fatty acids such as oleic acid, stearic acid, palmitic acid, and lauric acid, and salts of the higher fatty acid (for example, metal salts). Examples of the metal atom in the metal salt of the above-mentioned higher fatty acid include an alkali metal atom such as a sodium atom or a potassium atom, and an alkaline earth metal atom such as a magnesium atom or a calcium atom.

The above phosphates are preferably partial esters of phosphoric acid. Examples of the above-mentioned phosphoric acid partial esters include a partial ester of phosphoric acid (monoesterified or diesterified) partially phosphoric acid (such as orthophosphoric acid), or a partial ester of the phosphoric acid. Salt (using a metal salt such as an alkali metal or the like) or the like.

The method for surface-treating the inorganic material by the surface treatment agent is not particularly limited, and examples thereof include a dry method, a wet method, and an overall blending method. In addition, the amount of the surface treatment agent in the surface treatment of the inorganic material by the surface treatment agent is not particularly limited, and is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 8 parts by weight, per 100 parts by weight of the inorganic substance.

Further, the 166 mesh residue of the inorganic material is not particularly limited, but is preferably 0.01% or less, more preferably 0.001% or less. The reason for this is that when the resin composition is foamed, if coarse particles are present, foaming of the cells is likely to occur. It is caused by the size of the particles exceeding The thickness of the cell wall.

The average grain diameter of the inorganic substance is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.2 to 5.0 μm, still more preferably 0.5 to 1.0 μm. When the average particle diameter is less than 0.1 μm, it may not be sufficiently acted as a nucleating agent. On the other hand, when the average particle diameter exceeds 10 μm, there is a case where the resin composition becomes a cause of outgassing during foaming, which is not preferable.

In particular, the above-mentioned foaming nucleating agent can easily obtain affinity with a resin, or can suppress foaming at the time of foaming due to generation of voids in the interface between the resin and the inorganic material, and can easily obtain a fine cell structure. In general, it is preferably a surface-treated inorganic substance (especially a surface-treated hard clay).

The content of the foaming nucleating agent in the resin composition is not particularly limited, and is preferably 0.1 to 20% by weight, more preferably 0.3 to 10% by weight, based on the total amount of the resin composition (100% by weight), and further Good is 0.5~6 wt%. When the content is 0.1% by weight or more, when the content is 0.1% by weight or more, the portion for forming bubbles (bubble forming portion) can be sufficiently ensured, and a fine cell structure can be easily obtained, which is preferable. In addition, when the content is 20% by weight or less, the viscosity of the resin composition is remarkably increased, and the outgas of the resin composition during foaming can be suppressed, and a uniform cell structure can be easily obtained, which is preferable.

Further, the above resin composition preferably contains an epoxy-modified polymer. The above epoxy-modified polymer functions as a crosslinking agent. Moreover, it functions as a modifier (resin modifier) which improves the melt tension and the strain hardening degree of the resin composition (especially the resin composition containing a polyester-type elastomer). Therefore, when the resin composition contains an epoxy-modified polymer, a foamed structure having a high foaming, fineness, and uniformity is obtained, and an interlayer peeling strength of a specific value or more is obtained, so that flexibility and excellent carrier tape are easily obtained. Characteristics (for example, foam damage inhibition when peeling off from the carrier tape, adhesion to the carrier tape, etc.). Further, the epoxy-modified polymer may be used singly or in combination of two or more.

The epoxy-modified polymer is not particularly limited, and it is difficult to form a three-dimensional network structure as compared with a compound having a low molecular weight epoxy group, and a resin composition excellent in melt tension and strain hardening degree can be easily obtained (especially containing In terms of the resin composition of the polyester-based elastomer, an epoxy-modified acrylic polymer selected from a polymer having an epoxy group at the terminal or side chain of the main chain of the acrylic polymer is preferred. Or at least one polymer of an epoxy-modified polyethylene having a polymer having an epoxy group at the end of the main chain of the polyethylene or a side chain.

The weight average molecular weight of the above epoxy-modified polymer is not particularly limited, but is preferably 5,000 to 100,000, more preferably 8,000 to 80,000, still more preferably 10,000 to 60,000, still more preferably 20,000 to 60,000. Further, when the molecular weight is less than 5,000, the reactivity of the epoxy-modified polymer is increased and the high foaming cannot be performed.

The epoxy equivalent of the epoxy-modified polymer is not particularly limited, but is preferably 100 to 3000 g/eq, more preferably 200 to 2500 g/eq, still more preferably 300 to 2000 g/eq, and particularly preferably 800 to 1600 g. /eq. When the epoxy equivalent of the epoxy-modified polymer is 3,000 g/eq or less, the melt tension and strain hardening degree of the resin composition (especially the resin composition containing the polyester elastomer) can be sufficiently increased, and the specificity can be easily obtained. It is preferable that the interlayer peeling strength or the high foaming and fine cell structure is higher than the value. In addition, when the epoxy equivalent of the epoxy-modified polymer is 100 g/eq or more, the reactivity of the epoxy-modified polymer can be suppressed from being improved, and the viscosity of the resin composition becomes too high to allow high foaming. Bad conditions are therefore ideal.

The viscosity (B type viscosity, 25 ° C) of the above epoxy-modified polymer is not particularly limited, but is preferably from 2,000 to 4,000 mPa·s, more preferably from 2,500 to 3,200 mPa·s. When the viscosity of the epoxy-modified polymer is 2,000 mPa·s or more, it is preferable to suppress breakage of the cell wall during foaming of the resin composition and to easily obtain a highly foamed and fine cell structure. On the other hand, when the viscosity is 4,000 mPa·s or less, the fluidity of the resin composition is easily obtained, and the resin composition can be effectively foamed, which is preferable.

In particular, the epoxy-modified polymer preferably has a weight average molecular weight of 5,000 to 100,000 and an epoxy equivalent of 100 to 3000 g/eq.

The content of the epoxy-modified polymer in the resin composition is not particularly limited, and is preferably 0.5 to 15.0 parts by weight, more preferably 0.6 to 10.0 parts by weight, per 100 parts by weight of the resin in the resin composition. Further, it is preferably 0.7 to 7.0 parts by weight, particularly preferably 0.8 to 3.0 parts by weight. When the content of the epoxy-modified polymer is 0.5 parts by weight or more, the melt tension and the strain hardening degree of the resin composition can be increased, and an interlayer peel strength of a specific value or more or a highly foamed and fine cell structure can be easily obtained. More ideal. In addition, when the content of the epoxy-modified polymer is 15.0 parts by weight or less, it is possible to suppress the problem that the viscosity of the resin composition is too high and the high foaming cannot be performed, and it is easy to obtain a highly foamed and fine cell structure. Therefore, it is ideal.

Further, the epoxy-modified polymer can prevent the cutting of the polyester chain caused by hydrolysis (for example, hydrolysis due to moisture absorption of the raw material), pyrolysis, oxidative decomposition, etc., and can be cut. Since the broken polyester chain is re-bonded, the melt tension of the resin composition containing the polyester elastomer can be further improved. Further, in the above epoxy-modified polymer, since the epoxy group has a plurality of epoxy groups in one molecule, it is easier to form a branched structure than the conventional epoxy-based crosslinking agent, and the poly-containing polymer can be further improved. The degree of strain hardening of the resin composition of the ester elastomer.

Further, the above resin composition preferably contains a lubricant. When the resin composition contains a lubricant, the formability of the resin composition is improved, which is preferable. The slidability becomes good, and it is preferable, for example, to be easily extruded from the extruder in a desired shape without stopping. Further, the lubricants may be used singly or in combination of two or more.

The lubricant is not particularly limited, and examples thereof include an aliphatic carboxylic acid and a derivative thereof (for example, an aliphatic carboxylic anhydride, an alkali metal salt of an aliphatic carboxylic acid, or an alkaline earth metal salt of an aliphatic carboxylic acid). As the above aliphatic carboxylic acid and derivatives thereof, preferred are lauric acid and derivatives thereof, stearic acid and derivatives thereof, crotonic acid and derivatives thereof, oleic acid and Its derivatives, maleic acid and its derivatives, glutaric acid and its derivatives, behenic acid and its derivatives, montanic acid and its derivatives, and other fatty acid carboxylic acids having 3 to 30 carbon atoms and their derivatives Things. Further, among the fatty acid carboxylic acids having a carbon number of 3 to 30 and derivatives thereof, stearic acid and derivatives thereof are preferred from the viewpoints of the dispersibility, solubility, and surface appearance of the resin composition. , montanic acid and its derivatives, particularly preferably alkali metal salts of stearic acid, alkaline earth metal salts of stearic acid. Further, among the alkali metal salts of stearic acid and the alkaline earth metal salts of stearic acid, zinc stearate or calcium stearate is more preferred.

Further, examples of the lubricant include an acrylic lubricant. For example, an acrylic polymer external lubricant (trade name "Metablen L", manufactured by Mitsubishi Rayon Co., Ltd.) or the like can be mentioned as a commercial product of the above-mentioned acrylic lubricant.

In particular, as the lubricant, an acrylic lubricant is preferred.

The content of the lubricant in the resin composition is not particularly limited, and is preferably 0.1 to 20 parts by weight, more preferably 0.3 to 10 parts by weight, even more preferably 100 parts by weight of the resin in the resin composition. 0.5 to 8 parts by weight. When the content of the lubricant is 0.1 part by weight or more, the effect obtained by containing the lubricant is easily obtained, which is preferable. On the other hand, when the content of the lubricant is 20 parts by weight or less, it is preferable to suppress the escape of bubbles during foaming of the resin composition and to suppress the problem that high foaming cannot be performed.

In the above resin composition, a crosslinking agent may be contained within a range not inhibiting the effects of the invention of the present application. The crosslinking agent is not particularly limited, and examples thereof include an epoxy crosslinking agent, an isocyanate crosslinking agent, a stanol alcohol crosslinking agent, a melamine resin crosslinking agent, a metal salt crosslinking agent, and a metal chelate. A compound-based crosslinking agent, an amine-based resin-based crosslinking agent, and the like. Further, the crosslinking agent may be used singly or in combination of two or more.

Further, the resin composition may contain a crystallization accelerator insofar as the effects of the invention of the present application are not inhibited. As the above crystallization accelerator, there is no particular limitation For example, an olefin resin can be mentioned. As such an olefin-based resin, a resin having a broad molecular weight distribution and a shoulder-type type on a high molecular weight side, a resin of a micro-crosslinking type (a resin in which a plurality of types are cross-linked), a resin having a long-chain branch type, and the like are preferable. . Examples of the olefin-based resin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, a copolymer of ethylene and propylene, ethylene or propylene, and other α-olefins (for example). a copolymer of butene-1, pentene-1, hexene-1, 4-methylpentene-1, etc., ethylene and other ethylenically unsaturated monomers (for example, vinyl acetate, acrylic acid, acrylate) a copolymer of methacrylic acid, methacrylic acid ester, vinyl alcohol, etc.). Further, when the olefin resin is a copolymer, it may be a copolymer of any of a random copolymer and a block copolymer. Further, the olefin resin may be used singly or in combination of two or more kinds.

Further, the resin composition may contain a flame retardant within a range that does not inhibit the effects of the invention of the present application. The reason for this is that the resin foaming system of the present invention contains a resin and therefore has a property of being easily burned, but may be used for applications in which it is necessary to impart flame retardancy to an electric machine or an electronic device. The flame retardant is not particularly limited, and examples thereof include powder particles having flame retardancy (for example, various flame retardants in a powder form), and an inorganic flame retardant is preferably used. The inorganic flame retardant may be, for example, a bromine-based flame retardant, a chlorine-based flame retardant, a phosphorus-based flame retardant, or an antimony-based flame retardant, but a chlorine-based flame retardant or a bromine-based flame retardant is burned. When a gas component which is harmful to the human body and corrosive to the machine is generated, and the phosphorus-based flame retardant or the antimony-based flame retardant has problems such as harmfulness or explosiveness, it is preferably a halogen-free and non-antimony-based inorganic resistor. Burning agent (inorganic flame retardant that does not contain halogen compounds and antimony compounds). Examples of the halogen-free antimony-based inorganic flame retardant include hydrated metal compounds such as aluminum hydroxide, magnesium hydroxide, magnesium oxide, nickel oxide hydrate, and magnesium oxide/zinc oxide hydrate. Furthermore, the hydrated metal oxide can also be surface treated. These flame retardants may be used singly or in combination of two or more.

Further, in the above resin composition, within the range not inhibiting the effects of the present invention, The following additives may also be included as needed. Examples of such an additive include a crystal nucleating agent, a plasticizer, a coloring agent (carbon black for coloring, a pigment, a dye, etc.), an ultraviolet absorber, an antioxidant, an anti-aging agent, a reinforcing agent, and an antistatic agent. Agent, surfactant, tension modifier, anti-shrinkage agent, fluidity modifier, vulcanizing agent, surface treatment agent, dispersing aid, modifier for polyester resin, and the like. Further, the additives may be used singly or in combination of two or more.

In particular, the resin composition obtains an interlayer peel strength of a specific value or more, a rebound force at a compression of 50% in a specific range, an average cell diameter within a specific range, and a maximum cell diameter of a specific value or less, even if it has a fineness. It is preferable that the cell structure is soft, and the foam damage suppressing property at the time of peeling off from the carrier tape and the workability and transportability at the time of carrying the tape are excellent at the level of the carrier tape. At least the following (i) to (iv).

(i): a polyester-based elastomer having a melt flow rate (MFR) of from 1.5 to 4.0 g/10 min at 230 ° C (preferably a melt flow rate (MFR) at 230 ° C of from 1.5 to 4.0 g/10 min, and The polyester elastomer as a block copolymer of a hard segment and a soft segment preferably has a melt flow rate (MFR) of from 1.5 to 4.0 g/10 min at 230 ° C, and an aromatic dicarboxylic acid and a hydroxyl group. a polyester formed by polycondensation of a diol component having a carbon number of 2 to 4 in a main chain with a hydroxyl group, which is a hard segment and a polyether as a soft segment. Copolymer)

(ii): epoxy modified polymer

(iii): lubricant (preferably acrylic lubricant)

(iv): foaming nucleating agent (preferably surface treated inorganic matter, more preferably surface treated hard clay)

The method for producing the resin composition is not particularly limited, and examples thereof include a treatment in which the above-mentioned resin, an additive to be added, and the like are mixed. Furthermore, heat can also be applied during production.

The melt tension (pull speed: 2.0 m/min) of the above resin composition is not particularly limited Preferably, it is preferably 15 to 70 cN, more preferably 13 to 60 cN, further preferably 15 to 55 cN, and particularly preferably 26 to 50 cN. When the melt tension of the resin composition is less than 10 cN, when the resin composition is foamed, the expansion ratio is low, and it is difficult to form independent bubbles, and the shape of the formed bubbles is less likely to be uniform. On the other hand, when the melt tension of the resin composition exceeds 70 cN, the fluidity is lowered to adversely affect the foaming.

In addition, the term "melt tension" means a tension when a molten resin extruded at a predetermined temperature and an extrusion speed is drawn into a rope at a predetermined drawing speed from a predetermined die using a predetermined apparatus. In the present invention, a Capillary Extrusion Rheometer manufactured by Malvern Co., Ltd. was used, and a resin having a diameter of 2 mm and a length of 20 mm was used to extrude the resin at a fixed speed of 8.8 mm/min at 2 m/min. The pull rate of the pull speed is set to the melt tension.

Further, the melt tension was measured from the melting point of the resin of the resin composition to a temperature of 10 ± 2 ° C on the high temperature side. This is because the resin does not become in a molten state at a temperature that does not reach the melting point, and on the other hand, it completely becomes a fluid at a temperature that greatly exceeds the melting point to the high temperature side, so that the melt tension cannot be measured.

The strain hardening degree (strain rate: 0.1 [1/s]) of the above resin composition is not particularly limited, but a uniform and dense cell structure is obtained, and foaming of cells at the time of foaming is suppressed to obtain high foaming. In terms of the foam, it is preferably from 2.0 to 5.0, more preferably from 2.5 to 4.5. Further, the strain hardening degree of the resin composition is a strain hardening degree at a melting point of the resin of the resin composition. Further, the strain hardening degree is a region in which the uniaxial elongation viscosity gradually rises (linear region) with an increase in strain after the start of the measurement, and the uniaxial elongation viscosity is over the region (non- In the linear region), an index indicating the degree of increase in the uniaxial elongation viscosity.

The resin foam of the present invention is preferably formed by foam molding the above resin composition. The foaming method of the above resin composition is not particularly limited, and it is preferred to After the high-pressure gas is impregnated into the resin composition, a pressure reduction method (release pressure) is performed. That is, the resin foam of the present invention is preferably formed by a step of impregnating the resin composition with a high-pressure gas and then reducing the pressure.

As the gas, an inert gas is preferred in terms of obtaining a clean resin foam. By inert gas is meant a gas which is inert to the resin composition and which can be impregnated. Furthermore, the gas system can also be used in combination.

Further, examples of the foaming method of the resin composition include a physical foaming method (a foaming method using a physical method) or a chemical foaming method (a foaming method using a chemical method). Concerned about the environmental impact of the flammability or toxicity of the material used as a foaming agent (foaming agent gas) and the destruction of the ozone layer in the physical foaming method, but the foaming method using an inert gas does not use such a hair. The method of the environment is considered in terms of the foaming agent. In the chemical foaming method, since the residue of the foaming gas generated by the foaming agent remains in the foam, there is a corrosive gas or gas especially when applied to an electronic device having a high degree of low pollution. The pollution caused by the impurities in the problem becomes a problem. However, according to the foaming method using an inert gas, a clean foam in which such impurities or the like are not present can be obtained. Further, in any of the physical foaming method and the chemical foaming method, it is considered that it is difficult to form a fine cell structure, and in particular, it is extremely difficult to form fine bubbles of 300 μm or less.

The inert gas is not particularly limited, and examples thereof include carbon dioxide gas (carbonic acid gas), nitrogen gas, helium gas, and air. Among them, carbon dioxide gas is preferred in terms of a large amount of impregnation and a high impregnation speed.

Further, in order to accelerate the impregnation speed to the resin composition, the high-pressure gas is preferably in a supercritical state. In the supercritical state, the solubility of the gas to the resin composition is increased, and high concentration of the mixture can be achieved. Further, when the pressure after impregnation is drastically lowered, as described above, it can be impregnated at a high concentration, so that the generation of bubble nuclei is increased, and even if the porosity is the same, the density of bubbles formed by the growth of the nuclei will increase, so that fineness can be obtained. Bubbles. Further, the critical temperature of carbon dioxide is 31 ° C and the critical pressure is 7.4 MPa.

As described above, the resin foam of the present invention is preferably produced by impregnating a resin composition with a high-pressure gas. However, in this case, a resin composition may be formed into a sheet shape or the like in advance. After forming an unfoamed resin molded body (unexpanded molded product), a high-pressure gas is impregnated into the unfoamed resin molded body, and a pressure is released to thereby form a batch method of foaming, and a resin may be used. The composition is kneaded together with a high-pressure gas under pressure to release the pressure while forming, while performing a continuous manner of forming and foaming.

The case where the resin foam of the present invention is produced in a batch manner will be described. In the batch method, first, an unfoamed resin molded body is produced when the resin foam is produced, and the method for producing the unfoamed resin molded body is not particularly limited, and for example, the resin composition is uniaxially extruded. A method of forming an extruder such as a machine or a twin-screw extruder; and kneading the resin composition in advance using a kneading machine equipped with a blade such as a roller, a cam, a kneading machine, or a Banbury type, and using heat A method of press molding into a specific thickness by a press machine of a plate, a method of forming a resin composition by using an injection molding machine, or the like. Among these methods, an appropriate method is preferably selected in such a manner as to obtain an unexpanded resin molded body of a desired shape or thickness. Further, the unfoamed resin molding system may be produced by other molding methods in addition to extrusion molding, press molding, and injection molding. Moreover, the shape of the unfoamed resin molded body is not limited to a sheet shape, and various shapes can be selected depending on the application. For example, a sheet shape, a roll shape, a corner column shape, a plate shape, etc. are mentioned. Then, bubbles are formed by placing the above-mentioned unfoamed resin molded body (molded body formed of the resin composition) into a pressure-resistant container (high-pressure container), injecting (introducing) a high-pressure gas, and making high-pressure gas a gas impregnation step in which a gas is impregnated into an unfoamed resin molded body; a pressure reduction step (generally at atmospheric pressure) at a time when the gas is sufficiently impregnated with a high pressure, and a decompression step of generating a bubble nucleus in the unfoamed resin molded body; In the case (if necessary), a heating step of growing the bubble nuclei by heating. Further, the bubble nucleus may be grown at room temperature without providing a heating step. After the bubble is grown in this manner, it is rapidly cooled by cold water or the like as needed, and the shape is fixed, whereby a resin foam can be obtained. Further, the introduction of the high-pressure gas may be carried out continuously or discontinuously. Further, as a heating method for growing the bubble nuclei, a well-known or conventional method such as a water bath, an oil bath, a hot roll, a hot air oven, far infrared rays, near infrared rays, or microwaves may be used.

In other words, the resin foam of the present invention can be formed by foaming a high-pressure gas by impregnating an unfoamed molded article containing the resin composition and then decompressing it. Further, it may be formed by further heating by subjecting a high-pressure gas to an unfoamed molded article containing the resin composition, followed by depressurization.

On the other hand, in the case of being produced in a continuous manner, for example, a case where the resin composition is kneaded by using an extruder such as a single-axis extruder or a twin-screw extruder while being injected is used. (introducing) a high-pressure gas, a gas impregnation step in which the gas is sufficiently impregnated in the resin composition; extruding the resin composition through a die or the like provided at the front end of the extruder, thereby releasing the pressure (usually, at atmospheric pressure) At the same time, the forming and decompression steps of forming and foaming are carried out. Further, depending on the case (if necessary), a heating step of growing the bubbles by heating may be provided. After the bubble is grown in this manner, it is rapidly cooled by cold water or the like as needed, and the shape is fixed, whereby a resin foam can be obtained. Further, in the kneading impregnation step and the molding decompression step, an injection molding machine or the like may be used in addition to the extruder.

That is, the resin foam of the present invention can be formed by foaming by subjecting a high-pressure gas to a molten resin composition and then performing a pressure reduction step. Moreover, the resin foam of the present invention can be formed by further heating by subjecting a high-pressure gas to a molten resin composition, followed by depressurization.

In the gas impregnation step in the above batch mode or the kneading impregnation step in the above-described continuous mode, the mixing amount of the gas is not particularly limited, and is preferably, for example, 1 to 10% by weight, more preferably, based on the total amount of the resin composition. It is 2 to 8 wt%.

In the gas impregnation step in the above batch mode or the kneading impregnation step in the above continuous mode, when the high pressure gas is impregnated into the unfoamed resin molded body or the resin composition The pressure is preferably 3 MPa or more (for example, 3 to 100 MPa), more preferably 4 MPa or more (for example, 4 to 100 MPa). When the gas pressure is less than 3 MPa, the bubble growth at the time of foaming is remarkable, and the bubble diameter becomes excessively large, and for example, a problem such as a decrease in dustproof effect is likely to occur, which is not preferable. The reason is that if the pressure is low, the amount of gas impregnation is relatively small compared to the case of high pressure, and the bubble nucleation rate decreases and the number of bubble nuclei formed decreases, so that the amount of gas per bubble increases instead of bubbles. The path is extremely increased. Further, in the pressure region of less than 3 MPa, the bubble diameter and the bubble density can be largely changed by merely changing the impregnation pressure a little, so that it is difficult to control the bubble diameter and the bubble density.

Further, in the gas impregnation step in the batch mode or the kneading impregnation step in the continuous mode, the temperature at which the high-pressure gas is impregnated into the unfoamed resin molded body or the polyester-based elastomer composition can be widely used. The selection is preferably 10 to 350 ° C in consideration of the operability or the like. For example, in the batch mode, the impregnation temperature in the case where the high-pressure gas is impregnated into the sheet-shaped unfoamed resin molded body is preferably 40 to 300 ° C, more preferably 100 to 250 ° C. Further, in the continuous mode, the temperature at which the high-pressure gas is injected into the resin composition and kneaded is preferably 150 to 300 ° C, more preferably 210 to 250 ° C. Further, in the case of using carbon dioxide as a high-pressure gas, in order to maintain the supercritical state, the temperature (impregnation temperature) at the time of impregnation is preferably 32 ° C or more (especially 40 ° C or more).

Further, in the pressure reduction step, the pressure reduction rate is not particularly limited, and is preferably 5 to 300 MPa/s in order to obtain uniform fine bubbles. Further, the heating temperature in the heating step is not particularly limited, but is preferably 40 to 250 ° C, more preferably 60 to 250 ° C.

Moreover, according to the method for producing a resin foam described above, a resin foam having a high expansion ratio can be produced, and thus a thick resin foam can be obtained. For example, in the case of manufacturing the resin foam by the above-described continuous method, in order to maintain the pressure inside the extruder in the kneading impregnation step, it is necessary to minimize the distance between the die mounted on the front end of the extruder (usually 0.1 to 1.0). Mm). Therefore, in order to obtain a thick resin foam, it is necessary to foam the resin composition extruded through a narrow pitch at a higher magnification, but it is not possible to obtain a higher hair previously. The bubble ratio, thus causing the thickness of the formed foam to be limited to a relatively thin one (for example, 0.5 to 2.0 mm). On the other hand, according to the method for producing the resin foam produced by using a high-pressure gas, a resin foam having a final thickness of 0.30 to 5.00 mm can be continuously obtained.

In the resin foam of the present invention, since the interlayer peel strength is at least a specific value, the properties of the carrier tape are excellent. For example, since it is possible to effectively suppress or prevent the destruction of the foam body when the self-supporting tape is peeled off, it is difficult to cause breakage of the resin foam when the resin foam is peeled off from the carrier tape.

Further, in the resin foam of the present invention, since the average cell diameter is within a specific range, the maximum cell diameter is not more than a specific value, and does not contain coarse cells, it has a uniform and fine cell structure. Therefore, on the surface of the foam, the adhesion area to the carrier tape can be enlarged, and the strength of the surface of the foam is excellent. Therefore, in the resin foam of the present invention, since the adhesion to the carrier tape is excellent, the transportability at the time of use of the carrier tape or the workability at the time of using the carrier tape is excellent. For example, it is possible to efficiently perform processing in which the resin foam is processed in a state of being bonded to the carrier tape, and one of the resin foams after the processing is carried out in series. Further, in the resin foam of the present invention, since the adhesion to the carrier tape is excellent, the pickup property is excellent. For example, the carrier tape can be attached to the resin foam to easily lift the resin foam. Further, when the resin foam is bonded to the adhesive tape having the adhesive layer on one side of the release film, the carrier tape is bonded to the resin foam, and then the carrier tape is lifted, and the self-release film and the adhesive layer are applied. The interface is peeled off, so that the structure of the carrier tape, the resin foam, and the adhesive layer can be easily obtained.

In the resin foam of the present invention, since the repulsive force at a compression of 50% is within a specific range, the average cell diameter is within a specific range, and the maximum cell diameter is below a specific value, a uniform and fine cell structure is obtained. Excellent in softness. Therefore, it is possible to follow a small gap.

In the resin foam of the present invention, since the average cell diameter is within a specific range, the maximum cell diameter is not more than a specific value, and does not contain coarse cells, it is difficult to generate dust from the coarse cells and the dustproof property is lowered. The problem. The resin foaming system of the present invention is also excellent in dustproofness.

The resin foaming system of the present invention can be preferably used as a sealing material or a dustproof material for an electric machine or an electronic machine. Moreover, it can be preferably used as a cushioning material or a shock absorbing material, and in particular, it can be preferably used as a cushioning material or a shock absorbing material for an electric machine or an electronic machine.

(foaming member)

The resin foaming system of the present invention can also be used as a foaming member. That is, the foaming member is a member including the above-described resin foam of the present invention. The foam member may be, for example, a structure including only the resin foam of the present invention described above, or may have at least the resin foam and the surface layer.

The shape of the foam member is not particularly limited, but is preferably a sheet shape (including a film shape) or a belt shape. Further, the foaming member may be processed in such a manner as to have a desired shape or thickness. For example, it can be processed into various shapes in accordance with the apparatus or machine used, the housing, the member, and the like.

The surface layer is not particularly limited. For example, a resin layer (polymer layer) is preferably used in terms of improving the properties of the carrier tape or improving the sealing property. The foam member may be, for example, a resin layer laminated on the resin foam of the present invention.

The resin layer is preferably a layer having the same resin composition as the resin foam of the present invention. The reason for this is that when the polymer layer is a layer composed of a material different from the above-described resin foam of the present invention, the physical properties of the resin foam are changed.

Moreover, when a resin layer which is a surface layer is laminated on a resin foam, the manufacturing process may become complicated. For example, when a resin layer as a surface layer is laminated on a resin foam by application of a resin forming a resin layer, welding of a resin layer, adhesion of a resin layer interposing an adhesive layer, or the like, Has an adverse effect on workability or productivity.

Therefore, the surface layer is more preferably a layer (heat-melted layer) formed by heat-melting treatment of the surface of the resin foam in terms of improving the characteristics of the carrier tape or improving the sealing property. According to the heat-melting treatment, it can be easily combined with the resin foam It is the same, so it is not necessary to consider the compatibility with other materials, and it is advantageous in terms of less thickness variation. Moreover, it is also advantageous in terms of workability.

The heat-melting treatment is not particularly limited, and examples thereof include a pressure treatment by a hot roll, a laser irradiation treatment, a contact melting treatment on a heated roll, a flame treatment, and the like.

In the case of the pressure treatment using a hot roll, it can be preferably processed using a heat bonding machine or the like. In addition, examples of the material of the roll include rubber, metal, and fluorine-based resin (for example, Teflon (registered trademark)).

The temperature of the heat-melting treatment is not particularly limited, and is preferably a temperature lower than the softening point or melting point of the resin constituting the resin foam by 15 ° C (more preferably lower than the softening point or melting point of the resin constituting the resin foam). The temperature of °C, more preferably at least 12 ° C lower than the softening point or melting point of the resin constituting the resin foam), is preferably 20 ° C higher than the softening point or melting point of the resin constituting the resin foam. The temperature (more preferably, the temperature is 10 ° C higher than the softening point or melting point of the resin constituting the resin foam). If the temperature at the time of heat-melting treatment is lower than the temperature lower than the softening point or melting point of the resin constituting the resin foam, the melting of the resin may not be performed. On the other hand, when the temperature at the time of the heat-melting treatment is higher than the temperature higher than the softening point or the melting point of the resin constituting the resin foam, there is a problem that the bubble structure shrinks and wrinkles occur.

The treatment time as the heat-melting treatment differs depending on the treatment temperature, and is, for example, preferably 0.1 second to 10 seconds, preferably 0.5 second to 7 seconds. If the time is too short, the surface may not be melted to cause formation of a surface layer. On the other hand, if the time is too long, there is a problem that the resin foam shrinks and wrinkles occur.

Further, as the surface layer, the adhesive sheet may be interposed between the foam member and the processing liner may be provided or fixed or temporarily fixed to the adherend (for example, a casing or a part). Preferably, the adhesive layer is exemplified.

The adhesive for forming the above adhesive layer is not particularly limited, and for example, Acrylic adhesive, rubber adhesive (natural rubber adhesive, synthetic rubber adhesive, etc.), polyoxynoxy adhesive, polyester adhesive, urethane adhesive, polyamine An adhesive, an epoxy adhesive, a vinyl alkyl ether adhesive, a fluorine adhesive, or the like. The adhesive system may be used alone or in combination of two or more. Further, the adhesive may be an adhesive of any form such as a latex adhesive, a solvent adhesive, a hot melt adhesive, an oligomer adhesive, or a solid adhesive. In particular, the adhesive is preferably an acrylic adhesive from the viewpoint of preventing contamination of the adherend. In other words, the foam member preferably has an acrylic pressure-sensitive adhesive layer on the resin foam of the present invention.

The thickness of the above adhesive layer is not particularly limited, but is preferably 2 to 100 μm, more preferably 10 to 100 μm. The thinner the adhesive layer layer is, the higher the effect of preventing the adhesion of dust or dust at the ends, and the thinner the thickness, the better. Further, the adhesive layer may have any one of a single layer and a laminate.

In the above foamed member, the above adhesive layer may be provided via another layer (lower layer). Examples of such a lower layer include other adhesive layers, intermediate layers, undercoat layers, and base material layers (especially, a film layer or a nonwoven fabric layer). Further, the adhesive layer may be protected by a release film (separator) (for example, a release paper, a release film, or the like).

Further, the foaming member may have the above-described resin foam and resin layer of the present invention in terms of sealing property, excellent properties to the carrier tape, fixing or temporary fixing, and the like. It is a heat-melted layer formed by heat-melting treatment, and an adhesive layer (especially an acrylic adhesive layer). For example, the foam member may have the resin layer (especially a heat-melted layer formed by heat-melting treatment) on one side of the sheet-like resin foam, or may have the other side surface side. Adhesive layer (especially acrylic adhesive layer).

Since the foaming member contains the above-described resin foam of the present invention, it is excellent in flexibility. Moreover, it has flexibility to follow a small gap. Further, the dustproof property is also excellent.

Moreover, since the said foaming member contains the resin foam of this invention mentioned above, it is excellent in the characteristics of a carrier tape. For example, it is excellent in the adhesiveness of a carrier tape and the peeling property of a self-carrier tape. Moreover, it is excellent in conveyability and workability at the time of using a carrier tape.

The above-mentioned foamed member has the characteristics as described above, and therefore can be preferably used as a member used when a plurality of members or parts are attached (mounted) to a specific portion. In particular, the foaming member is used in an electric or electronic device, and can be preferably used as a member used when attaching (mounting) a component constituting an electric or electronic device to a specific portion.

That is, the above foaming member can be preferably used as an electric or electronic machine. That is, the foam member may be a foam member for electric or electronic equipment.

The various members or components that can be attached (mounted) by the above-described foaming member are not particularly limited, and for example, various members or parts of electric or electronic equipment can be preferably used. Examples of the member or the component for the electric or electronic device include an image display member (display portion) mounted on an image display device such as a liquid crystal display, an electroluminescence display, or a plasma display (especially a small image). A display member) or an optical member or optical component such as a camera or a lens (especially a small camera or lens) mounted on a device for communicating with a mobile device such as a "mobile phone" or "mobile information terminal".

The preferred embodiment of the foam member of the present invention is used for the purpose of dustproof, light-shielding, buffering, etc., and is used around a display portion such as an LCD (liquid crystal display) or clamped to an LCD ( A case where the display unit and the casing (window portion) are used in a liquid crystal display or the like.

(foaming member laminate)

The foamed member laminate system of the present invention comprises at least the above-mentioned foamed member (a member comprising the above-described resin foam of the present invention) and a carrier tape (especially a carrier tape having an adhesive layer on at least one side of the substrate) The structure has a structure in which the foam member is held by a carrier tape.

As described above, since the foamed member laminate system has a configuration in which the foam member is bonded to the adhesive surface of the carrier tape, the foam member can be bonded to the adhesive surface of the carrier tape. When the foam member is used, it is possible to suppress or prevent the foam from being broken, and the foam member can be easily peeled off from the carrier tape.

The carrier tape is not particularly limited, and it is important to have at least one adhesive layer to exert a sufficient degree of adhesion (adhesion force) required for holding the foam member during processing or transport of the foam member. When the foamed member is peeled off, it is possible to exert an adhesive force (adhesion force) to the extent that it is easy to peel off without damaging the surface.

Therefore, as the carrier tape, an adhesive tape (adhesive tape or sheet) having an adhesive layer using an adhesive can be cited. In particular, from the viewpoint of achieving both the adhesion to the foam member and the releasability, it is preferable to use an acrylic adhesive (particularly, an alkyl (meth)acrylate is used as a main monomer component. An acrylic adhesive tape in which an acrylic polymer is used as an adhesive layer (acrylic adhesive layer) of an acrylic adhesive of a base polymer. The adhesive tape may have any one of an adhesive tape with a base material formed on at least one side surface of the substrate, and a non-substrate adhesive tape formed of only an adhesive layer. However, in terms of workability or workability, an adhesive tape with a substrate is preferred.

In addition, examples of the adhesive other than the acrylic adhesive in the adhesive for forming the adhesive layer include a rubber-based adhesive (a natural rubber-based adhesive, a synthetic rubber-based adhesive, etc.), and a polyfluorene-based system. An adhesive, a polyester-based adhesive, a urethane-based adhesive, a polyamide-based adhesive, an epoxy-based adhesive, a vinyl alkyl ether-based adhesive, a fluorine-based adhesive, or the like. The adhesive system may be used alone or in combination of two or more. Further, the adhesive may be any one of a form of an adhesive such as a latex adhesive, a solvent adhesive, a hot melt adhesive, an oligomer adhesive, or a solid adhesive.

Moreover, the base material in the adhesive tape is not particularly limited, and examples thereof include a plastic base material such as a plastic film or a sheet; a paper base material such as paper; a fibrous base material such as a cloth, a nonwoven fabric, or a mesh; and a metal. a metal-based substrate such as a foil or a metal plate; a rubber-based substrate such as a rubber sheet; a foam such as a foamed sheet, or a laminate (especially a plastic substrate and other substrates) A suitable sheet such as a laminate or a plastic film (or sheet) laminated to each other.

Further, the thickness of the substrate or the adhesive layer in the adhesive tape as the carrier tape is not particularly limited.

According to the foamed member laminated body, the foamed member is processed until it has a specific shape, and then the foamed member is peeled off from the carrier tape, whereby a foamed member having a specific shape can be obtained. The foamed member is peeled off at the interface between the foamed member and the carrier tape, has little or no bubble breakage, maintains a good cell structure, and is processed into a specific shape. Therefore, the foamed member obtained by processing using the foamed member laminated body can be preferably used as a sealing material, a dustproof material, a cushioning material, and the like when the various members or components are mounted (mounted) on a specific portion. Shock absorbers, etc. In particular, the foam member can be preferably used even when a small member or component is attached to a thinned product.

(electrical or electronic equipment)

The electric or electronic device of the present invention has the above-described foam member (member including the above-described resin foam of the present invention). That is, the electric or electronic device of the present invention has a configuration in which the above-described foam member is used. In the electric or electronic equipment, the foaming member is used, for example, as a dustproof material, a sealing material, a vibration absorbing material, a cushioning material, or the like. Such an electric or electronic device has a configuration in which a member or a member for an electric or electronic device is attached (mounted) to a specific portion via the foam member. Specifically, examples of the electric or electronic device include an image display device such as a liquid crystal display, an electroluminescence display, or a plasma display in which an optical member or a component is interposed between the resin foam or the foam member. In particular, an image or display device having a small image display member as an optical member, or an electric or electronic device (for example, a "mobile phone" or a camera or a lens (especially a small camera or lens). "Mobile information communication device such as "action information terminal"). Such an electric or electronic device may be a product which is thinner than the prior art, and the thickness, shape, and the like are not particularly limited.

[Examples]

Hereinafter, the present invention will be more specifically described by way of examples and comparative examples. The invention is not limited by these.

(Example 1)

A block copolymer of polybutylene terephthalate as a hard segment and a polyether as a soft segment (trade name "Pelprene P-90BD", manufactured by Toyobo Co., Ltd., melt flow rate at 230 ° C: 3.0 g/10 min, melting point: 204 ° C): 100 parts by weight, an acrylic lubricant (trade name "Metablen L-1000", manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, surface treatment with a decane coupling agent Hard clay (trade name "ST-301", manufactured by Shiraishi Calcium Co., Ltd.): 1 part by weight, carbon black (trade name "旭#35", manufactured by Asahi Carbon Co., Ltd.): 5 parts by weight and epoxy Modifier (epoxy modified acrylic polymer, weight average molecular weight (Mw): 50000, epoxy equivalent: 1200 g/eq, viscosity: 2850 mPa‧s): 2 parts by weight, using a biaxial kneading machine at 220 ° C After kneading at a temperature, it is extruded into a rope shape, and after water cooling, it is cut into pellets and formed.

The pellet was placed in a single-screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an environment of 240 °C. After the carbon dioxide gas was sufficiently saturated, it was cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-shaped polyester elastomer foam having a thickness of 2.0 mm.

(Example 2)

The polyester elastomer foam produced in Example 1 was heated at a pitch of 0.95 mm using a heat bonding machine (device name "MRK-6504", manufactured by MCK Co., Ltd.) with adjustable roll pitch. The surface thermal fusion treatment was carried out under the conditions of a temperature of 190 ° C and a treatment rate of 12 m / min to obtain a polyester elastomer foam having a surface layer.

(Example 3)

A block copolymer of polybutylene terephthalate as a hard segment and a polyether as a soft segment (trade name "Pelprene P-90BD", manufactured by Toyobo Co., Ltd., Melt flow rate at 230 ° C: 3.0 g/10 min, melting point: 204 ° C): 100 parts by weight, an acrylic lubricant (trade name "Metablen L-1000", manufactured by Mitsubishi Rayon Co., Ltd.): 1 part by weight, utilized Hard clay (product name "ST-301", manufactured by Shiraishi Calcium Co., Ltd.) which is surface-treated with a decane coupling agent: 1 part by weight, carbon black (trade name "旭#35", manufactured by Asahi Carbon Co., Ltd.): 5 parts by weight and an epoxy-based modifier (epoxy-modified acrylic polymer, weight average molecular weight (Mw): 50,000, epoxy equivalent: 1200 g/eq, viscosity: 2850 mPa·s): 2 parts by weight, using double The shaft kneading machine was kneaded at a temperature of 220 ° C, and then extruded into a rope shape, and after water cooling, it was cut into pellets and formed.

The pellet was placed in a single-screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an environment of 240 °C. After the carbon dioxide gas was sufficiently saturated, it was cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-shaped polyester elastomer foam having a thickness of 2.0 mm.

(Example 4)

A block copolymer of polybutylene terephthalate as a hard segment and a polyether as a soft segment (trade name "Pelprene P-90BD", manufactured by Toyobo Co., Ltd., melt flow rate at 230 ° C: 3.0 g/10 min, melting point: 204 ° C): 100 parts by weight, an acrylic lubricant (trade name "Metablen L-1000", manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, surface treatment with a decane coupling agent Hard clay (trade name "ST-301", manufactured by Shiraishi Calcium Co., Ltd.): 3 parts by weight, carbon black (trade name "旭#35", manufactured by Asahi Carbon Co., Ltd.): 5 parts by weight and epoxy Modifier (epoxy modified acrylic polymer, weight average molecular weight (Mw): 50000, epoxy equivalent: 1200 g/eq, viscosity: 2850 mPa‧s): 2 parts by weight, using a biaxial kneading machine at 220 ° C After kneading at a temperature, it is extruded into a rope shape, and after water cooling, it is cut into pellets and formed. The pellet was placed in a single-screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 MPa after injection) in an environment of 240 °C. After fully saturating the carbon dioxide gas, After cooling to a temperature suitable for foaming, it was extruded from a die to obtain a sheet-like polyester elastomer foam having a thickness of 1.5 mm.

(Comparative Example 1)

A block copolymer of polybutylene terephthalate as a hard segment and a polyether as a soft segment (trade name "Hytrel 5577", manufactured by Du Pont Toray Co., Ltd., 230 ° C Melt flow rate: 1.8 g/10 min, melting point 208 ° C): 100 parts by weight, acrylic lubricant (trade name "Metablen L-1000", manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, polypropylene (product "NEWSTREN SH9000", manufactured by Japan Polypropylene Co., Ltd.): 1 part by weight, magnesium hydroxide (average particle diameter: 0.7 μm): 1 part by weight, carbon black (trade name "旭#35", Asahi Carbon Co., Ltd.): 5 parts by weight and an epoxy-based crosslinking agent (trifunctional epoxy compound, trade name "TEPIC-G", manufactured by Nissan Chemical Industries, Ltd.): 0.5 parts by weight, using biaxial kneading After kneading at a temperature of 220 ° C, the machine was extruded into a rope shape, and after water cooling, it was cut into pellets and formed.

The pellet was placed in a single-screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an environment of 240 °C. After the carbon dioxide gas was sufficiently saturated, it was cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-shaped polyester elastomer foam having a thickness of 2.2 mm.

(Comparative Example 2)

Polypropylene (melt flow rate (MFR): 0.35 g/10 min): 45 parts by weight, polyolefin-based elastomer (melt flow rate (MFR): 6 g/10 min): 55 parts by weight, polyethylene: 10 parts by weight, A nucleating agent (magnesium hydroxide, average particle diameter: 0.7 μm): 10 parts by weight and carbon black (trade name "Asahi #35", manufactured by Asahi Carbon Co., Ltd.): 5 parts by weight, using a biaxial kneading machine, After kneading at a temperature of 200 ° C, it was extruded into a rope shape, and after water cooling, it was cut into pellets to obtain a particulate matter.

The pellet was placed in a single-axis extruder manufactured by Nippon Steel Co., Ltd. at 220 ° C. In the environment, carbon dioxide gas is injected at a pressure of 13 (12 after injection) MP. The carbon dioxide gas system was injected at a ratio of 5% by weight based on the total amount of the particulate matter. After the carbon dioxide gas was sufficiently saturated, it was cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-like resin foam having a thickness of 2.3 mm.

(Comparative Example 3)

A commercially available polyurethane having an average cell diameter of 160 μm, a compression of 50%, a rebound stress (50% anti-repulsion load) of 0.7 N/cm ² and an apparent density of 0.15 g/cm ³ was used. A foam of ingredients.

The foaming system was in the form of a sheet having a thickness of 1.0 mm.

(Evaluation)

The following measurements or evaluations were performed on the examples and comparative examples. Then, the results are shown in Table 1.

(visual density)

The foam was punched out by a punching die having a width of 20 mm and a length of 20 mm, and was set as a sheet-like test piece. The size of the test piece was measured using a vernier caliper. Also, using the diameter of the measuring terminal ( The thickness of the test piece was measured for a 1/100 dial gauge of 20 mm. The volume of the test piece was calculated from the equivalent values. Next, the weight of the test piece was measured using an electronic balance. The apparent density (g/cm ³ ) of the foam was calculated by the following formula based on the volume of the test piece and the weight of the test piece.

The apparent density of the foam (g/cm ³ ) = (weight of the test piece) / (volume of the test piece)

(average cell diameter, maximum cell diameter)

A magnifying microscope (trade name "VHX-500", manufactured by KEYENCE Co., Ltd.) was used to obtain an enlarged image of the bubble portion of the foam, and image analysis was performed using the analysis software of the measuring device. The cell diameter (μm) of the cells was determined, and the average cell diameter (μm) and the maximum cell diameter (μm) were determined. The number of bubbles of the enlarged image obtained is about 200. Furthermore, the cell diameter is determined by the area of the cell, and the diameter of the circle is approximated. Converted to the original.

(interlayer peel strength)

A test piece having a width of 20 mm and a length of 120 mm was obtained from the foam, and the test piece was stored in an environment of temperature: 23 ± 2 ° C and humidity: 50 ± 5% for 24 hours. Furthermore, the pretreatment conditions are based on JIS Z 0237.

Adhesive tape (width: 20mm, length: 120mm, trade name "No.5603", manufactured by Nitto Denko Co., Ltd., with adhesive tape on both sides of the substrate, substrate: PET (Polyethylene terephthalate, ethylene terephthalate) One of the side adhesive faces of the substrate is attached to a SUS plate (Steel Use Stainless), and the above adhesive tape is fixed on the SUS plate. Next, the test piece was attached to the other adhesive side of the above-mentioned adhesive tape fixed to the SUS plate, and crimped under the condition of 2 kg of roller and one round trip.

After the pressure bonding, a tensile tester (device name "TCN-1kNB", manufactured by Minebea Co., Ltd.) was used, and the test piece was peeled off from the adhesive tape under the conditions of a peeling angle of 90° and a tensile speed of 0.3 m/min. Peel strength (N/20mm). The measured peel strength was defined as the interlayer peel strength.

(Rebound force when compressing 50% (repulsive load at 50% compression, 50% load compression))

The measurement was carried out in accordance with the compression hardness measurement method disclosed in JIS K 6767.

The foam was cut into a test piece having a width of 30 mm and a length of 30 mm. Then, the test piece was compressed at a compression speed of 10 mm/min in the thickness direction until the compression ratio became 50%, and the stress (N) was converted into a rebound force (N/) in terms of a unit area (1 cm ² ). Cm ² ).

(pickup)

A test piece having a width of 20 mm and a length of 120 mm was obtained from the foam, and the test piece was stored in an environment of temperature: 23 ± 2 ° C and humidity: 50 ± 5% for 24 hours. Furthermore, the pretreatment conditions are based on JIS Z 0237.

One side of the test piece was made of adhesive tape A (width: 20 mm, length: 120 mm, trade name "No. 5603", manufactured by Nitto Denko Co., Ltd., adhesive tape on both sides of the substrate, substrate: PET substrate) It is fixed to a release paper which is treated with a polyfluorene-based release agent. Next, on the other side of the test piece, the carrier tape (trade name "3164S", manufactured by Kern Co., Ltd.) was attached in the form of contact between the test piece and the adhesive layer of the carrier tape, under the condition of 2 kg of roller and one round trip. The pressure was applied and left for 24 hours to obtain a sample for evaluation.

When the carrier tape of the evaluation sample is lifted by hand, the laminate between the release paper and the adhesive tape A in the evaluation sample is peeled off to obtain a laminate of the carrier tape and the test piece and the adhesive tape A. "Good" (○). On the other hand, when the carrier tape of the sample for evaluation is lifted by hand, the interface between the test piece and the carrier tape in the sample for evaluation is peeled off, and the laminate of the carrier tape and the test piece and the adhesive tape cannot be obtained. The evaluation was "bad" (×).

(foam destruction inhibition)

A test piece having a width of 20 mm and a length of 120 mm was obtained from the foam, and the test piece was stored in an environment of temperature: 23 ± 2 ° C and humidity: 50 ± 5% for 24 hours. Furthermore, the pretreatment conditions are based on JIS Z 0237.

Adhesive tape A was attached to one side of the test piece (width: 20 mm, length: 120 mm, trade name "No. 5603", manufactured by Nitto Denko Co., Ltd., adhesive tape on both sides of the substrate, substrate: PET substrate) And the test piece was fixed to a SUS plate (stainless steel plate). After the fixing, the test piece on the SUS plate was attached to the test piece in the form of contact with the adhesive layer (trade name "3164S", manufactured by Kern Co., Ltd.), and pressed under a condition of 2 kg of roller and one round trip. The sample was placed for 24 hours to obtain a sample for evaluation.

The carrier tape of the sample for evaluation was quickly peeled off by hand, and the state of the test piece after peeling was visually observed, and it evaluated based on the following evaluation criteria.

Good (○): No surface damage of the test piece was produced.

Poor (x): Surface damage of the test piece was produced.

(reworkability)

A test piece having a width of 10 mm and a length of 120 mm was obtained from the foam, and the test piece was stored in an environment of temperature: 23 ± 2 ° C and humidity: 50 ± 5% for 24 hours. Furthermore, the pretreatment conditions are based on JIS Z 0237.

Adhesive tape A was attached to one side of the test piece (width: 10 mm, length: 120 mm, trade name "No. 5603", manufactured by Nitto Denko Co., Ltd., adhesive tape on both sides with substrate, substrate: PET substrate) The pressure bonding was carried out under the condition of 2 kg of rollers and one round trip, and the test piece was fixed to a SUS plate (stainless steel plate).

The foam was peeled off by hand from the foam with the adhesive tape described above, and the peeling state was visually confirmed, and the reworkability was evaluated based on whether or not the layers of the resin foam were broken.

Good (○): no interlayer damage of the foam was produced.

Poor (X): The interlayer damage of the foam is produced.

(melt tension)

For the measurement of the melt tension, a resin extruded at a fixed speed of 8.8 mm/min was pulled at a pulling speed of 2 m/min using a Capillary Extrusion Rheometer manufactured by Malvern Co., Ltd. from a capillary having a diameter of 2 mm and a length of 20 mm. The tension is set to the melt tension.

Further, at the time of measurement, the particulate matter before foam molding was used. Further, the temperature at the time of measurement was a temperature of 10 ± 2 ° C from the melting point of the resin to the high temperature side.

(strain hardening degree)

At the time of measurement, the particulate matter before foam molding was used. The pellet was formed into a sheet having a thickness of 1 mm using a heated hot plate press to obtain a sheet, and a sample was cut from the sheet (vertical: 10 mm, transverse: 10 mm, thickness: 1 mm).

From the above samples, a uniaxial elongation viscosity at a strain rate of 0.1 [1/s] was measured using a uniaxial elongation viscometer (manufactured by TA Instruments). Then, the strain hardening degree was obtained according to the following formula.

Strain hardening degree = log η max / log η 0.2

(ηmax represents the elongational viscosity at the highest uniaxial elongational viscosity, and η0.2 represents the elongational viscosity when the strain ε is 0.2).

Further, the temperature at the time of measurement was made the melting point of the resin.

In the embodiment, since the interlayer peeling strength of the foam is 10 N/20 mm or more, there are no coarse cells having a cell diameter of 200 μm or more, and the cell structure is uniform, so that the carrier tape can be picked up and the bubble is generated. The problem of destruction. On the other hand, in the foam of Comparative Example 1, since the coarse cells were contained, the proportion of the cell walls on the surface of the foam was reduced, and the adhesion to the carrier tape was weakened, and it was difficult to pick up the carrier tape. . Further, in the foams of Comparative Examples 2 and 3, since the interlayer peeling strength was small, the foam damage suppressing property was inferior. Therefore, when the carrier tape was attached to the foams of Comparative Examples 2 and 3, the carrier tape was peeled off, and the foam of the foam was broken.

[Industrial availability]

The resin foaming system of the present invention is applied to electrical or electronic machines (for example, mobile phones, mobile terminals, smart phones, tablet personal computers, digital Cameras, video cameras, digital video cameras, personal computers, home appliances, etc.).

Claims (16)

A resin foam characterized in that the interlaminar peel strength defined below is 10 N/20 mm or more, the rebound force at a compression of 50% is 0.1 to 4.0 N/cm ² , and the average cell diameter is 10 to 200 μm. The cell diameter is 300 μm or less, and the interlaminar peeling strength is attached to the adhesive surface of the adhesive tape (trade name "No. 5603", manufactured by Nitto Denko Corporation) at 23 ° C in the sheet-like resin foam. After the pressure-bonding under the condition of 2 kg of the roller and one round trip, the peeling strength of the resin foam at the peeling angle of 90° and the tensile speed of 0.3 m/min was peeled off from the adhesive tape. The resin foam of claim 1, wherein the apparent density is from 0.01 to 0.20 g/cm ³ . The resin foam of claim 1 or 2, wherein the resin constituting the resin foam is a thermoplastic resin. The resin foam of claim 3, wherein the thermoplastic resin is a polyester. The resin foam according to any one of claims 1 to 4, wherein the resin foaming system is formed by a step of subjecting a high-pressure gas to a resin composition and then performing a pressure reduction. The resin foam of claim 5, wherein the gas is an inert gas. The resin foam of claim 5 or 6, wherein the gas is carbon dioxide. The resin foam according to any one of claims 5 to 7, wherein the high-pressure gas is in a supercritical state. A foamed member comprising the resin foam according to any one of claims 1 to 8. The foam member according to claim 9, wherein the surface layer is contained on the resin foam. The foam member of claim 10, wherein the surface layer is foamed by the resin The layer formed by the heat treatment of the surface of the body. The foam member of claim 10, wherein the surface layer is an adhesive layer. The foam member of claim 12, wherein the adhesive layer is an acrylic adhesive layer. A foamed member according to any one of claims 9 to 13, which is for use in an electrical or electronic machine. A foamed member laminate comprising a foam member having any one of claims 9 to 14 by a carrier tape comprising an adhesive layer on at least one side of the substrate. An electrical or electronic machine characterized by comprising the foam member of any one of claims 9 to 14.