JP5509370B1 - Resin foam, foam member, foam laminate, and electrical or electronic equipment - Google Patents

Abstract

[PROBLEMS] To suppress or prevent foam breakage when peeling from a carrier tape, even if it is a flexible resin foam having a fine cell structure, and processability and transportability when held on a carrier tape. Provided is a resin foam excellent in.
The resin foam of the present invention has a delamination strength as defined below of 10 N / 20 mm or more, a repulsive force at 50% compression of 0.1 to 4.0 N / cm ² , and an average The cell diameter is 10 to 200 μm, and the maximum cell diameter is 300 μm or less.
Interlaminar peel strength: A sheet-like resin foam is attached to an adhesive surface of an adhesive tape (trade name “No. 5603”, manufactured by Nitto Denko Corporation) in a 23 ° C. atmosphere, and is crimped under conditions of 2 kg roller and one reciprocation. After peeling, the peel strength when the above resin foam is peeled from the above adhesive tape at a peel angle of 90 ° and a tensile speed of 0.3 m / min [Selection] None

Description

  The present invention relates to a resin foam, a foam member, a foam member laminate, and electrical or electronic equipment. More specifically, a resin foam used for electrical or electronic devices (for example, mobile phones, mobile terminals, smartphones, tablet computers (tablet PCs), digital cameras, video cameras, digital video cameras, personal computers, home appliances, etc.) The present invention relates to a foam member having the resin foam, a foam member laminate having the foam member, and electrical or electronic equipment having the foam member.

  In general, the resin foam is punched in the required shape according to the shape of the member used, and the surface of the resin foam is subjected to adhesive processing to facilitate fixing to the member. However, since the resin foam subjected to such processing is not easy to handle, a carrier tape may be used to efficiently transport the resin foam to a predetermined location. That is, the resin foam is subjected to various types of processing (such as punching or adhesive processing) while being adhered to the carrier tape, or is conveyed after processing. On the other hand, after processing, the resin foam needs to be peeled off from the carrier tape. However, if the strength of the surface of the resin foam is low (weak), the resin foam may be destroyed at the time of peeling. It was. In particular, in the case of a resin foam having a high expansion ratio [for example, heat formed through a process of depressurizing after impregnating a thermoplastic resin with a high-pressure inert gas (for example, supercritical carbon dioxide). Plastic resin foam etc.] (refer to Patent Document 1), and the thickness of the cell wall was so thin that breakage during peeling was likely to occur. In particular, when the resin foam contains coarse cells, the ratio of the cell walls on the surface of the foam is reduced, and breakage during peeling is more likely to occur.

  In addition, if a carrier tape with a lower adhesive strength is used to prevent breakage at the time of peeling, it may be displaced during processing, resulting in reduced dimensional stability (shape stability), or processing when assembling a foam member. There has been a problem that the tape cannot be assembled by being peeled off from the carrier tape before being peeled off from the mounting board.

JP 2001-247706 A

Accordingly, an object of the present invention is to suppress or prevent foam breakage when peeling from a carrier tape, even if it is a flexible resin foam having a fine cell structure, The object is to provide a resin foam excellent in processability and transportability.
Furthermore, another object of the present invention is to provide a foamed member using the resin foam, a foamed member laminate using the foamed member, and an electric or electronic device using the foamed member. There is.

  Therefore, as a result of intensive studies by the present inventors, in the resin foam, the delamination strength is set to a specific value or more, the repulsive force at 50% compression is within a specific range, and the average cell diameter is within a specific range. Furthermore, when the maximum cell diameter is set to a specific value or less, it has a fine cell structure, obtains excellent flexibility, suppresses foam breakage when peeled from the carrier tape, and processability held on the carrier tape. In addition, it has been found that transportability can be obtained. The present invention has been completed based on these findings.

That is, the present invention is a resin foam formed by foaming a resin composition containing at least a resin and an epoxy-modified polymer, the resin constituting the resin foam is a thermoplastic resin, and the thermoplastic The resin is polyester, the delamination strength defined below is 10 N / 20 mm or more, the repulsive force at 50% compression is 0.1 to 4.0 N / cm ² , and the average cell diameter is 10 to 200 μm. The resin foam is characterized in that the maximum cell diameter is 300 μm or less.
Interlaminar peel strength: A sheet-like resin foam is attached to an adhesive surface of an adhesive tape (trade name “No. 5603”, manufactured by Nitto Denko Corporation) in a 23 ° C. atmosphere, and is crimped under conditions of 2 kg roller and one reciprocation. Then, the peel strength when the resin foam was peeled from the adhesive tape under the conditions of a peel angle of 90 ° and a tensile speed of 0.3 m / min.

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

  The resin foam is preferably formed through a step of depressurizing the resin composition after impregnating the resin composition with a high-pressure gas.

  The gas is preferably an inert gas.

  The gas is preferably carbon dioxide.

  The high-pressure gas is preferably in a supercritical state.

  Furthermore, this invention provides the foaming member characterized by including said resin foam.

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

  The surface layer is preferably a layer formed by heating and melting the surface of the resin foam.

  The surface layer is preferably a pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive layer.

  The foamed member is preferably for electric or electronic equipment.

  Furthermore, the present invention provides a foamed member laminate, wherein the foamed member has a configuration in which the foamed member is held by a carrier tape having an adhesive layer on at least one side of the substrate.

  Furthermore, the present invention provides electrical or electronic equipment having the foamed member.

  Since the resin foam of the present invention has the above-mentioned configuration, it has a fine cell structure, and even if it is a flexible resin foam, foam breakage (destruction of the cell structure in the foam) when peeling from the carrier tape Can be suppressed or prevented, and excellent properties with respect to the carrier tape such as processability and transportability when held on the carrier tape.

The resin foam of the present invention has a delamination strength of 10 N / 20 mm or more as defined below, a repulsion force at 50% compression of 0.1 to 4.0 N / cm ² , and an average cell diameter of 10 ˜200 μm, and the maximum cell diameter is 300 μm or less.
Interlaminar peel strength: A sheet-like resin foam is attached to an adhesive surface of an adhesive tape (trade name “No. 5603”, manufactured by Nitto Denko Corporation) in a 23 ° C. atmosphere, and is crimped under conditions of 2 kg roller and one reciprocation. Then, the peel strength when the resin foam is peeled from the pressure-sensitive adhesive tape under the conditions of a peel angle of 90 ° (degrees) and a tensile speed of 0.3 m / min. In the present specification, the interlayer defined above is used. The peel strength may be simply referred to as “interlayer peel strength”.

  The resin foam of the present invention is formed by foaming a composition (resin composition) containing at least the 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) of the resin with respect to the total amount (100% by weight) of the resin composition.

  The delamination strength of the resin foam of the present invention is 10 N / 20 mm or more, preferably 15 N / 20 mm or more, more preferably 20 N / 20 mm or more. Since the delamination strength of the resin foam of the present invention is 10 N / 20 mm or more, the resin foam is excellent in suppression of foam breakage when being peeled from the carrier tape. For example, at the time of transporting the resin foam, when the resin foam is peeled off from the carrier tape after the resin foam is temporarily fixed and transported by the carrier tape, the resin foam is hardly broken. The upper limit of the delamination strength is not particularly limited, but is preferably 60 N / 20 mm, more preferably 50 N / 20 mm.

Rebound stress at 50% compression of the resin foam of the present invention is not particularly limited, is preferably 0.1~4.0N / cm ^2, more preferably 0.3~3.5N / cm ² More preferably, it is 0.5 to 3.0 N / cm ² . The resin foam of the present invention preferably has a rebound stress at 50% compression of 0.1 N / cm ² or more because it can easily obtain appropriate rigidity and good workability. Moreover, when the repulsive stress at the time of 50% compression is 4.0 N / cm ² or less, excellent flexibility is easily obtained, which is preferable.

  The repulsive stress at the time of 50% compression means the compressive stress when the compressibility is 50%. The compression ratio of 50% means that the sheet-like resin foam is compressed to a state corresponding to 50% of the initial height in the thickness direction, that is, to a state where the initial thickness is distorted by 50%. This means that the thickness of the sheet-like resin foam having a compression rate of 50% corresponds to a thickness of 50% of the initial thickness.

  The average cell diameter of the resin foam of this invention is 10-200 micrometers, More preferably, it is 15-150 micrometers, More preferably, it is 20-100 micrometers. Since the resin foam of the present invention has an average cell diameter of 10 μm or more, it has excellent flexibility. In addition, since the average cell diameter is 200 μm or less, the generation of pinholes can be suppressed and excellent dust resistance is obtained. Moreover, the contact | adherence area with respect to a carrier tape can be enlarged, and the characteristic with respect to a carrier tape is excellent.

  The maximum cell diameter of the resin foam of the present invention is 300 μm or less, more preferably 250 μm or less, and further preferably 200 μm. Since the maximum cell diameter of the resin foam of the present invention is 300 μm or less, the cell structure is excellent in uniformity, and since it does not contain coarse cells, it is excellent in strength and characteristics with respect to the carrier tape. In addition, it is possible to suppress the problem that dust enters from a coarse cell and the dust resistance deteriorates, and the sealing performance and dust resistance are excellent.

  The cell diameter in the cell structure of the resin foam of the present invention is obtained, for example, by taking an enlarged image of the cell structure part (bubble structure part) of the cut surface with a digital microscope, obtaining the cell area, and converting to an equivalent circle diameter. Desired.

  Since the resin foam of the present invention has an average cell diameter of 10 to 200 μm and a maximum cell diameter of 300 μm, it has a uniform and fine cell structure. Moreover, the coarse cell is not included.

  The cell structure of the resin foam of the present invention is not particularly limited, but it has a semi-continuous semi-closed cell structure (a mixture of closed-cell structure and open-cell structure from the viewpoint of strength, sealability, dustproof property, and flexibility. It is a cell structure, and the ratio is not particularly limited. In particular, a cell structure in which the closed cell structure part is 40% or less (preferably 30% or less) in the resin foam is preferable.

The apparent density of the resin foam of the present invention is not particularly limited, is preferably 0.01~0.20g / cm ^3, more preferably 0.02~0.17g / cm ^3, more preferably 0 0.03 to 0.15 g / cm ³ . The resin foam of the present invention preferably has a density of 0.01 g / cm ³ or more because good strength can be easily obtained. Moreover, it is preferable for the density to be 0.20 g / cm ³ or less because a high expansion ratio can be obtained and excellent flexibility can be easily obtained. That is, when the apparent density of the resin foam of the present invention is 0.01 to 0.20 g / cm ³ , better foaming characteristics (high foaming ratio) can be obtained, moderate strength, excellent flexibility, It becomes easy to demonstrate excellent cushioning properties.

  Although the shape of the resin foam of this invention is not specifically limited, It is preferable that it is a sheet form or a tape form. Further, it may 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, 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, particularly preferably. 0.08 to 1.0 mm.

  Although it does not specifically limit as resin which is the raw material of the resin foam of this invention, A thermoplastic resin is mentioned preferably. The resin foam of the present invention may be composed of only one kind of resin, or 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 another α-olefin (for example, Copolymer with butene-1, pentene-1, hexene-1, 4-methylpentene-1, etc.), ethylene and other ethylenically unsaturated monomers (for example, vinyl acetate, acrylic acid, acrylic ester, Polyolefin resins such as copolymers with methacrylic acid, methacrylic acid esters, vinyl alcohol, etc.); styrene resins such as polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS resin); 6-nylon, 66-nylon, Polyamide resin such as 12-nylon; Polyurethane; Polyimide; Polyetherimide; Acrylic resin such as polymethyl methacrylate; Polyvinyl chloride; Polyvinyl fluoride; Alkenyl aromatic resin; Polyester resin such as polyethylene terephthalate and polybutylene terephthalate; Bisphenol A polycarbonate Polycarbonate; polyacetal; polyphenylene sulfide and the like. Moreover, a thermoplastic resin may be used individually or in combination of 2 or more types. In addition, when a thermoplastic resin is a copolymer, the copolymer of any form of a random copolymer and a block copolymer may be sufficient.

  The thermoplastic resin includes a rubber component and / or a thermoplastic elastomer component. Since the rubber component and the thermoplastic elastomer component have a glass transition temperature of room temperature or lower (for example, 20 ° C. or lower), they are remarkably excellent in flexibility and shape followability when formed into a resin foam. In addition, the resin foam of this invention may be formed with the resin composition containing said thermoplastic resin and a rubber component and / or a thermoplastic elastomer component.

  The rubber component or thermoplastic elastomer component is not particularly limited as long as it has rubber elasticity and can be foamed. For example, natural rubber, polyisobutylene, polyisoprene, chloroprene rubber, butyl rubber, nitrile butyl rubber and the like are used. Or synthetic rubber; olefin-based elastomers such as ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, polybutene, chlorinated polyethylene; styrene-butadiene-styrene copolymer, styrene- Examples thereof include styrene elastomers such as isoprene-styrene copolymers and hydrogenated products thereof; polyester elastomers; polyamide elastomers; and various thermoplastic elastomers such as polyurethane elastomers. Moreover, these rubber components or thermoplastic elastomer components may be used alone or in combination of two or more.

  As the above thermoplastic resin, delamination strength of a specific value or more, repulsive force at the time of 50% compression within a specific range, average cell diameter within a specific range, maximum cell diameter below a specific value, Even if it has a fine cell structure and is flexible, it has excellent properties for carrier tape, such as foam breakage prevention when peeling from the carrier tape, and processability and transportability when held on the carrier tape. More preferred are polyesters (polyesters such as the above polyester resins and polyester elastomers), and more preferred are polyester elastomers. That is, the resin foam of the present invention is more preferably a resin foam (polyester elastomer foam) formed from a resin composition containing a polyester elastomer.

  The polyester elastomer is not particularly limited as long as it is a resin having an ester bond site by reaction (polycondensation) between a polyol component and a polycarboxylic acid component. For example, aromatic dicarboxylic acid (divalent aromatic carboxylic acid) Examples thereof include polyester-based thermoplastic resins obtained by condensation polymerization of an acid) and a diol component.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenecarboxylic acid (for example, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, etc.), diphenyl ether dicarboxylic acid, 4,4 Examples include '-biphenyldicarboxylic acid. In addition, aromatic dicarboxylic acid may be used individually or in combination of 2 or more types.

  Examples of the diol component include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol (tetramethylene glycol), 2-methyl-1,3-propanediol, 1,5-pentanediol, 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-pen Diol, 1,9-nonanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,10-decanediol, 2-methyl-1,9-nonanediol Aliphatic diols such as 1,18-octadecanediol and dimer diol; 1,4-cyclohexanediol, 1,3-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexane Cycloaliphatic diols such as dimethanol and 1,2-cyclohexanedimethanol; aromatic diols such as bisphenol A, ethylene oxide adducts of bisphenol A, bisphenol S, ethylene oxide adducts of bisphenol S, xylylene diol, and naphthalene diol; Le, triethylene glycol, tetraethylene glycol, polyethylene glycol, a diol component such as ether glycol and dipropylene glycol. The diol component may be a diol component in a polymer form such as polyether diol or polyester diol. Examples of the polyether diol include polyether diols such as polyethylene glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like, polypropylene glycol, polytetramethylene glycol, and copolyether obtained by copolymerization thereof. Can be mentioned. Moreover, a diol component may be used individually or in combination of 2 or more types.

  Examples of the polyester thermoplastic resin include polyalkylene terephthalate resins such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and polycyclohexane terephthalate. Moreover, the copolymer obtained by copolymerizing 2 or more types of the said polyalkylene terephthalate type-resin is also mentioned. When the polyalkylene terephthalate resin is a copolymer, it may be a copolymer in any form of a random copolymer, a block copolymer, and a graft copolymer.

  Furthermore, examples of the polyester elastomer include a polyester elastomer that is a block copolymer of a hard segment and a soft segment.

  Examples of such a polyester elastomer (polyester elastomer that is a block copolymer of a hard segment and a soft segment) include, for example, (i) the aromatic dicarboxylic acid, and a hydroxyl group and a hydroxyl group among the diol components. A polyester formed by polycondensation with a diol component having 2 to 4 carbon atoms in the main chain in between is a hard segment, and the hydroxyl group and hydroxyl group of the aromatic dicarboxylic acid and the diol component A polyester / polyester type copolymer having a soft segment as a polyester formed by polycondensation with a diol component having 5 or more carbon atoms in the main chain therebetween; (ii) the same as (i) above Polyester as a hard segment and a polyether diol such as the above polyether diol Polyester-polyether type copolymer with tellur as soft segment; (iii) Polyester / polyester type with polyester similar to (i) and (ii) as hard segment and aliphatic polyester as soft segment And the like.

  In particular, when the resin foam of the present invention is a polyester elastomer foam, the polyester elastomer constituting the polyester elastomer is preferably a block copolymer of a hard segment and a soft segment, more preferably the above ( a polyester-polyether type copolymer of ii) (polyester formed by polycondensation of an aromatic dicarboxylic acid and a diol component having 2 to 4 carbon atoms in the main chain between the hydroxyl group and the hydroxyl group) Is a polyester / polyether type copolymer having a hard segment and a polyether as a soft segment.

  More specifically, the polyester / polyether type copolymer of (ii) is a polyester / polyether type block copolymer having polybutylene terephthalate as a hard segment and polyether as a soft segment. Etc.

  The melt flow rate (MFR) at 230 ° C. of the resin constituting the resin foam of the present invention 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, more preferably 1.5 to 3.5 g / 10 min. It is preferable that the melt flow rate (MFR) at 230 ° C. of the resin is 1.5 g / 10 min or more, since the moldability of the resin composition used for forming the resin foam of the present invention is improved. Moreover, it is preferable for the resin to have a melt flow rate (MFR) at 230 ° C. of 4.0 g / 10 min or less because it becomes difficult for the cell diameter to vary after the cell structure is formed, and a uniform cell structure is easily obtained. In the present specification, MFR at 230 ° C. refers to 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) at 230 ° C. of 1.5 to 4.0 g / 10 min. In particular, when the resin foam of the present invention is a polyester elastomer foam, a polyester elastomer (especially a hard segment and a soft segment) having a melt flow rate (MFR) at 230 ° C. of 1.5 to 4.0 g / 10 min. It is preferable to be formed of a resin composition containing a polyester-based elastomer).

  The resin composition forming the resin foam of the present invention preferably contains a foam nucleating agent in addition to the above-mentioned resin. When the resin composition contains a foam nucleating agent, it becomes easy to obtain a resin foam in a good foamed state. In addition, a foam nucleating agent may be used individually or in combination of 2 or more types.

  Although it does not specifically limit as said foaming nucleating agent, An inorganic substance is mentioned preferably. Examples of the inorganic substance include hydroxides such as aluminum hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide; clay (particularly hard clay); talc; silica; zeolite; and alkali such as calcium carbonate and magnesium carbonate. Earth metal carbonates; for example, metal oxides such as zinc oxide, titanium oxide, and alumina; 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 silicate;

  Among these, clay and alkaline earth metal carbonate are preferable, more preferably hard, from the viewpoint of suppressing the generation of coarse cells and easily obtaining a uniform and fine cell structure as the foam nucleating agent. Clay.

  The hard clay is a clay containing almost no coarse particles. In particular, the hard clay is preferably a clay having a 166 mesh screen residue of 0.01% or less, and more preferably a clay having a 166 mesh screen residue of 0.001% or less. The sieve residue (sieving residue) is a ratio (weight basis) to the whole although it remains without passing through the sieve.

  The hard clay includes aluminum oxide and silicon oxide as essential components. The total proportion of aluminum oxide and silicon oxide in the hard clay is preferably 80% by weight or more (for example, 80 to 100% by weight), more preferably 90% by weight with respect to the total amount of the hard clay (100% by weight). This is the above (for example, 90 to 100% by weight). The hard clay may be fired.

  The average particle size (average particle size) of the hard clay is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.2 to 5.0 μm, and still more preferably 0.5 to 1.0 μm. .

  Moreover, it is preferable that the said inorganic substance is surface-treated. That is, the foam nucleating agent is preferably a surface-treated inorganic substance. Although it does not specifically limit as a surface treating agent used for the surface treatment of an inorganic substance, it improves affinity with resin (especially polyester) by giving surface processing treatment, and at the time of foaming, shaping | molding, kneading | mixing, extending | stretching From the point of obtaining the effect that voids do not occur at the time and the cell does not break during foaming, aluminum compounds, silane compounds, titanate compounds, epoxy compounds, isocyanate compounds, higher fatty acids or salts thereof, and phosphorus Acid esters are preferred, and silane compounds (particularly silane coupling agents), higher fatty acids or salts thereof (particularly stearic acid) are more preferred. In addition, the said surface treating agent may be used individually or in combination of 2 or more types.

  That is, it is particularly preferable that the surface treatment in the inorganic material is a silane coupling treatment or a treatment with a higher fatty acid or a salt thereof.

  The aluminum compound is not particularly limited, but an aluminum coupling agent is preferable. Examples of the aluminum coupling agent include acetoalkoxyaluminum diisopropylate, aluminum ethylate, aluminum isopropylate, mono sec-butoxyaluminum diisopropylate, aluminum sec-butyrate, ethyl acetoacetate aluminum diisopropylate, aluminum tris. (Ethyl acetoacetate), aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate), cyclic aluminum oxide isopropylate, cyclic aluminum oxide isostearate and the like.

  The silane compound is not particularly limited, but a silane coupling agent is preferable. Examples of the silane coupling agent include a vinyl group-containing silane coupling agent, a (meth) acryloyl group-containing silane coupling agent, an amino group-containing silane coupling agent, an epoxy group-containing silane coupling agent, Examples include mercapto group-containing silane coupling agents, carboxyl group-containing silane coupling agents, and halogen atom-containing silane coupling agents. Specifically, examples of the silane coupling agent include vinyltrimethoxysilane, vinylethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, vinyl-tris (2 -Methoxy) silane, vinyltriacetoxysilane, 2-methacryloxyethyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxy-propylmethyldimethoxysilane, 3-aminopropyl Trimethoxylane, 3-aminopropyltriethoxysilane, 2-aminoethyltrimethoxysilane, 3- [N- (2-aminoethyl) amino] propyltrimethoxysilane, 3- [N- (2- Minoethyl) amino] propyltriethoxysilane, 2- [N- (2-aminoethyl) amino] ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxy (Cyclohexyl) ethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3- Examples include mercaptopropyltrimethoxysilane, carboxymethyltriethoxysilane, 3-carboxypropyltrimethoxysilane, and 3-carboxypropyltriethoxysilane.

  The titanate compound is not particularly limited, but a titanate coupling agent is preferable. Examples of the titanate coupling agent include isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, isopropyl tridecylbenzenesulfonyl titanate, tetraisopropyl bis (Dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxy Acetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethac Examples include ylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, dicumyl phenyl oxyacetate titanate, and diisostearoyl ethylene titanate.

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

  Although the said isocyanate type compound is not specifically limited, A polyisocyanate type compound and a monoisocyanate type compound are preferable. Examples of the polyisocyanate compounds include aliphatic diisocyanates such as tetramethylene diisocyanate and hexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate and 4,4′-dicyclohexylmethane diisocyanate; diphenylmethane diisocyanate and 2,4-tolylene diene. Aromatic diisocyanates such as isocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, toluylene diisocyanate; free isocyanate groups by reaction of these diisocyanate compounds with polyol compounds The polymer which has is mentioned. Examples of the monoisocyanate compound include phenyl isocyanate and stearyl isocyanate.

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

  The phosphoric acid esters are preferably phosphoric acid partial esters. Examples of the phosphoric acid partial esters include phosphoric acid partial esters in which phosphoric acid (such as orthophosphoric acid) is partially esterified (mono or diesterified) with an alcohol component (such as stearyl alcohol), or the phosphoric acid Examples include salts of partial esters (metal salts such as alkali metals).

  Although it does not specifically limit as a method at the time of surface-treating to the said inorganic substance with a surface treating agent, For example, a dry method, a wet method, an integral blend method etc. are mentioned. The amount of the surface treatment agent when the surface treatment is performed on the inorganic material is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0. 3 to 8 parts by weight.

  Moreover, although the 166 mesh sieve residue of the said inorganic substance is not specifically limited, 0.01% or less is preferable, More preferably, it is 0.001% or less. This is because, when the resin composition is foamed, if coarse particles are present, cell foam breakage is likely to occur. This is because the size of the particles exceeds the thickness of the cell wall.

  Although the average particle diameter (average particle diameter) of the inorganic substance is not particularly limited, it is preferably 0.1 to 10 μm, more preferably 0.2 to 5.0 μm, and still more preferably 0.5 to 1.0 μm. If the average particle size is less than 0.1 μm, it may not function sufficiently as a nucleating agent. On the other hand, if the average particle diameter exceeds 10 μm, it may cause gas loss during foaming of the resin composition, which is not preferable.

  In particular, the above foaming nucleating agent is capable of easily obtaining a fine cell structure by suppressing foam breakage during foaming due to the affinity with the resin and the generation of voids at the interface between the resin and the inorganic substance. A surface-treated inorganic material (particularly surface-treated hard clay) is preferred.

  Although content of the foam nucleating agent in the said resin composition is not specifically limited, 0.1-20 weight% is preferable with respect to the resin composition whole quantity (100 weight%), More preferably, it is 0.3-10. % By weight, more preferably 0.5 to 6% by weight. When the content is 0.1% by weight or more, when the content is 0.1% by weight or more, a site for forming bubbles (bubble formation site) can be sufficiently secured, and fine It is easy to obtain a cell structure, which is preferable. In addition, when the content is 20% by weight or less, it is possible to suppress the viscosity of the resin composition from significantly increasing, and further, it is possible to suppress outgassing at the time of foaming of the resin composition, and it is easy to obtain a uniform cell structure. It is preferable.

  Moreover, it is preferable that the said resin composition contains an epoxy-modified polymer. The epoxy-modified polymer acts as a crosslinking agent. Moreover, it acts as a modifier (resin modifier) that improves the melt tension and strain hardening degree of a resin composition (particularly a resin composition containing a polyester elastomer). For this reason, when the resin composition contains an epoxy-modified polymer, a delamination strength of a predetermined value or more is obtained while obtaining a highly foamed and fine and uniform cell structure. It becomes easy to obtain characteristics (for example, foam breakage inhibiting property at the time of peeling from the carrier tape, adhesiveness to the carrier tape, etc.). In addition, an epoxy modified polymer may be used individually or in combination of 2 or more types.

  The epoxy-modified polymer is not particularly limited, but 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 (especially a polyester elastomer is excellent in melt tension and strain hardening degree). Resin composition), an epoxy-modified acrylic polymer which is a polymer having an epoxy group at the end or side chain of the main chain of the acrylic polymer, or the end or side chain of the main chain of polyethylene. It is preferably at least one polymer selected from epoxy-modified polyethylene, which is a polymer having an epoxy group.

  The weight average molecular weight of the 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, particularly preferably. 20,000-60,000. In addition, when the molecular weight is less than 5,000, the reactivity of the epoxy-modified polymer increases, and high foaming may not be achieved.

  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. It is. When the epoxy equivalent of the epoxy-modified polymer is 3000 g / eq or less, the melt tension and strain hardening degree of a resin composition (particularly a resin composition containing a polyester-based elastomer) can be sufficiently improved. It is preferable because a fine cell structure can be easily obtained due to the delamination strength and high foaming. Moreover, when the epoxy equivalent of the epoxy-modified polymer is 100 g / eq or more, the reactivity of the epoxy-modified polymer increases, the viscosity of the resin composition becomes too high, and the disadvantage that high foaming cannot be suppressed is preferable.

  The viscosity (B-type viscosity, 25 ° C.) of the epoxy-modified polymer is not particularly limited, but is preferably 2000 to 4000 mPa · s, more preferably 2500 to 3200 mPa · s. It is preferable that the viscosity of the epoxy-modified polymer is 2000 mPa · s or more because it is easy to obtain a fine cell structure with high foaming by suppressing the destruction of the cell walls during foaming of the resin composition. On the other hand, when the viscosity is 4000 mPa · s or less, the fluidity of the resin composition is easily obtained, and the resin composition can be efficiently foamed.

  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.

  Although content of the said epoxy modified polymer in the said resin composition is not specifically limited, 0.5-15.0 weight part is preferable with respect to 100 weight part of resin in a resin composition, More preferably, it is 0.00. The amount is 6 to 10.0 parts by weight, more preferably 0.7 to 7.0 parts by weight, and 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 strain hardening degree of the resin composition can be increased, delamination strength exceeding a specific value, high foaming and fine Since it becomes easy to obtain a cell structure, it is preferable. In addition, when the content of the epoxy-modified polymer is 15.0 parts by weight or less, it is possible to suppress a problem that the viscosity of the resin composition becomes too high and cannot be highly foamed, and a highly foamed and fine cell structure is obtained. Since it becomes easy, it is preferable.

  The epoxy-modified polymer can prevent the polyester chain from being broken by hydrolysis (for example, hydrolysis due to moisture absorption of raw materials), thermal decomposition, oxidative decomposition, etc., and rebond the cut polyester chain. Therefore, the melt tension of the resin composition containing the polyester elastomer can be further improved. In addition, since the epoxy-modified polymer has a large number of epoxy groups in one molecule, it is easier to form a branched structure than a conventional epoxy-based crosslinking agent, and the strain hardening degree of a resin composition containing a polyester-based elastomer Can be further improved.

  Moreover, it is preferable that the said resin composition contains a lubricant. When the resin composition contains a lubricant, the moldability of the resin composition is improved, which is preferable. The slipping property is improved, which is preferable because it can be easily extruded in a desired shape from, for example, an extruder. In addition, a lubricant may be used alone or in combination of two or more.

  Although it does not specifically limit as said lubricant, For example, aliphatic carboxylic acid and its derivative (For example, aliphatic carboxylic acid anhydride, alkali metal salt of aliphatic carboxylic acid, alkaline earth metal salt of aliphatic carboxylic acid, etc.) Is mentioned. Examples of the aliphatic carboxylic acid and derivatives thereof include lauric acid and derivatives thereof, stearic acid and derivatives thereof, crotonic acid and derivatives thereof, oleic acid and derivatives thereof, maleic acid and derivatives thereof, glutaric acid and derivatives thereof, behen C3-C30 fatty acid carboxylic acids such as acids and derivatives thereof, montanic acid and derivatives thereof, and derivatives thereof are preferred. Among the fatty acid carboxylic acids having 3 to 30 carbon atoms and derivatives thereof, stearic acid and derivatives thereof, montanic acid and derivatives thereof are included from the viewpoint of dispersibility in the resin composition, solubility, surface appearance improvement effect, and the like. In particular, an alkali metal salt of stearic acid and an alkaline earth metal salt of stearic acid are preferable. Further, among the alkali metal salt of stearic acid and the alkaline earth metal salt of stearic acid, zinc stearate and calcium stearate are more preferable.

  Further, examples of the lubricant include acrylic lubricants. Examples of commercially available acrylic lubricants include acrylic polymer external lubricants (trade name “METABREN L”, manufactured by Mitsubishi Rayon Co., Ltd.).

  In particular, the lubricant is preferably an acrylic lubricant.

  Although content of the said lubricant in the said resin composition is not specifically limited, 0.1-20 weight part is preferable with respect to 100 weight part of resin in a resin composition, More preferably, 0.3-10 weight Parts, more preferably 0.5 to 8 parts by weight. When the content of the lubricant is 0.1 parts by weight or more, the effect obtained by including 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 because the problem that air bubbles cannot be removed when foaming the resin composition and high foaming cannot be achieved can be suppressed.

  The resin composition may contain a crosslinking agent as long as the effects of the present invention are not impaired. The crosslinking agent is not particularly limited. For example, epoxy crosslinking agent, isocyanate crosslinking agent, silanol crosslinking agent, melamine resin crosslinking agent, metal salt crosslinking agent, metal chelate crosslinking agent, amino resin crosslinking agent. Agents and the like. In addition, a crosslinking agent may be used individually or in combination of 2 or more types.

  Further, the resin composition may contain a crystallization accelerator as long as the effects of the present invention are not impaired. Although it does not specifically limit as said crystallization promoter, For example, an olefin resin is mentioned. As such an olefin resin, a resin having a broad molecular weight distribution and having a shoulder on the high molecular weight side, a micro-crosslinked resin (a slightly crosslinked resin), a long-chain branched resin, and the like are preferable. Examples of the olefin 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 another α-olefin (for example, butene- 1, copolymer with pentene-1, hexene-1, 4-methylpentene-1, etc., ethylene and other ethylenically unsaturated monomers (for example, vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid) , Methacrylic acid esters, vinyl alcohol, etc.) and the like. When the olefin resin is a copolymer, it may be a copolymer in any form of a random copolymer or a block copolymer. Moreover, an olefin resin may be used individually or in combination of 2 or more types.

  Further, the resin composition may contain a flame retardant as long as the effects of the present invention are not impaired. This is because the resin foam of the present invention includes a resin and thus has a property of being easily burned, but may be used in applications where it is essential to impart flame retardancy such as electrical or electronic equipment. Although it does not specifically limit as said flame retardant, For example, the powder particle (for example, various powdery flame retardants etc.) which has a flame retardance is mentioned, An inorganic flame retardant is mentioned preferably. The inorganic flame retardant may be, for example, a brominated flame retardant, a chlorine flame retardant, a phosphorus flame retardant, an antimony flame retardant, or the like. It generates a gas component that is harmful to the environment and corrosive to equipment, and phosphorous flame retardants and antimony flame retardants have problems such as toxicity and explosive properties. Inorganic flame retardants (inorganic flame retardants free of halogen compounds and antimony compounds) are preferred. Examples of the non-halogen-nonantimony inorganic flame retardant include aluminum hydroxide, magnesium hydroxide, hydrated metal compounds such as magnesium oxide / nickel oxide hydrate, magnesium oxide / zinc oxide hydrate, and the like. It is done. The hydrated metal oxide may be surface treated. The said flame retardant may be used individually or in combination of 2 or more types.

  Furthermore, the following additives may be contained in the resin composition as necessary within a range not impairing the effects of the present invention. Examples of such additives include crystal nucleating agents, plasticizers, colorants (carbon black, pigments, dyes, etc. for the purpose of black coloring), ultraviolet absorbers, antioxidants, anti-aging agents, reinforcing agents, Examples thereof include an antistatic agent, a surfactant, a tension modifier, a shrinkage inhibitor, a fluidity modifier, a vulcanizing agent, a surface treatment agent, a dispersion aid, and a polyester resin modifier. Moreover, an additive may be used individually or in combination of 2 or more types.

In particular, the resin composition obtains a delamination strength equal to or higher than a specific value, a repulsion force at 50% compression within a specific range, an average cell diameter within a specific range, and a maximum cell diameter below a specific value. Even if it has a fine cell structure and is flexible, it has excellent properties for carrier tape such as foam breakage inhibiting property when peeled from carrier tape and processability and transportability held on carrier tape. From the standpoint, it is preferable to include at least the following (i) to (iv).
(I): A polyester elastomer having a melt flow rate (MFR) at 230 ° C. of 1.5 to 4.0 g / 10 min (preferably a melt flow rate (MFR) at 230 ° C. of 1.5 to 4.0 g / min). A polyester elastomer that is a block copolymer of hard segments and soft segments, more preferably a melt flow rate (MFR) at 230 ° C. of 1.5 to 4.0 g / 10 min, and an aromatic dicarboxylic acid Polyester / polyether having polyester as a hard segment and polyether as a soft segment formed by polycondensation with a diol component having 2 to 4 carbon atoms in the main chain between the hydroxyl group and the hydroxyl group Type copolymer)
(ii): epoxy-modified polymer (iii): lubricant (preferably acrylic lubricant)
(Iv): Foam nucleating agent (preferably a surface-treated inorganic material, more preferably a surface-treated hard clay)

  Although it does not specifically limit as a preparation method of the said resin composition, For example, mixing the said resin, the additive added as needed, etc. are mentioned. Note that heat may be applied during manufacture.

  The melt tension (take-off speed: 2.0 m / min) of the resin composition is not particularly limited, but is preferably 15 to 70 cN, more preferably 13 to 60 cN, still more preferably 15 to 55 cN, and particularly preferably 26 to 50 cN. It is. When the resin composition has a melt tension of less than 10 cN, when the resin composition is foamed, the expansion ratio is low, independent bubbles are not easily formed, and the shape of the formed bubbles is uniform. It becomes difficult. On the other hand, when the melt tension of the resin composition exceeds 70 cN, the fluidity is lowered, and foaming may be adversely affected.

  The melt tension refers to a tension when a molten resin extruded from a specified die at a specified temperature and extrusion speed is drawn into a strand at a specified take-up speed using a specified apparatus. In the present invention, a Capillary Extension Rheometer manufactured by Malvern was used, and the resin extruded at a constant speed of 8.8 mm / min from a capillary having a diameter of 2 mm and a length of 20 mm was taken up at a take-up speed of 2 m / min. The value is the melt tension.

  The melt tension is a value measured at a temperature of 10 ± 2 ° C. from the melting point of the resin of the resin composition to the high temperature side. This is because the resin does not enter a molten state at a temperature lower than the melting point, and on the other hand, at a temperature greatly exceeding the melting point to the high temperature side, the resin becomes completely fluid and the melt tension cannot be measured.

  Although the strain hardening degree (strain rate: 0.1 [1 / s]) of the resin composition is not particularly limited, it has a uniform and dense cell structure and suppresses cell bubble breakage during foaming and is highly foamed. From the point which obtains a foam, 2.0-5.0 are preferable, More preferably, it is 2.5-4.5. The strain hardening degree of the resin composition is a degree of strain hardening at the melting point of the resin of the resin composition. In addition, in the measurement of uniaxial elongational viscosity, the degree of strain hardening deviates from the region (linear region) where uniaxial elongational viscosity gradually increases with increasing strain after the start of measurement, and the region where uniaxial elongational viscosity rises (nonlinear region). Is an index indicating the degree of increase in uniaxial elongational viscosity.

  It is preferable that the resin foam of this invention is formed by foam-molding the said resin composition. The foaming method of the resin composition is not particularly limited, but a foaming method in which the resin composition is impregnated with a high-pressure gas and then depressurized (pressure is released) is preferable. That is, the resin foam of the present invention is preferably formed through a step of reducing the pressure after impregnating the resin composition with a high-pressure gas.

  As said gas, an inert gas is preferable from the point of obtaining a clean resin foam. The inert gas refers to a gas that is inert to the resin composition and can be impregnated. The gas may be used as a mixture.

  In addition, as a foaming method of a resin composition, a physical foaming method (foaming method by a physical method) and a chemical foaming method (foaming method by a chemical method) are also mentioned. In the physical foaming method, there is concern about the flammability and toxicity of substances used as the foaming agent (foaming agent gas) and environmental impacts such as ozone layer destruction, but the foaming method using an inert gas is This is an environmentally friendly method in that no foaming agent is used. In the chemical foaming method, the residue of the foaming gas generated by the foaming agent remains in the foam, so that contamination by corrosive gas and impurities in the gas is a problem, especially for electronic devices where low pollution requirements are high. It may become. However, according to the foaming method using an inert gas, a clean foam free from such impurities can be obtained. Furthermore, it is difficult to form a fine cell structure in both the physical foaming method and the chemical foaming method, and it is particularly difficult to form fine bubbles of 300 μm or less.

  The inert gas is not particularly limited, and examples thereof include carbon dioxide gas (carbon dioxide gas), nitrogen gas, helium, and air. Among these, carbon dioxide gas is preferable because it has a large amount of impregnation and a high impregnation rate.

  Further, from the viewpoint of increasing the impregnation rate into the resin composition, the high-pressure gas is preferably in a supercritical state. In the supercritical state, the solubility of the gas in the resin composition increases and high concentration can be mixed. In addition, when the pressure drops suddenly after impregnation, since it is possible to impregnate at a high concentration as described above, the generation of bubble nuclei increases, and the density of bubbles formed by the growth of the bubble nuclei has a porosity. Even if they are the same, they become larger, so that fine bubbles can be obtained. Carbon dioxide has a critical temperature of 31 ° C. and a critical pressure of 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. In this case, the resin composition is preliminarily formed into an appropriate shape such as a sheet. After forming into an unfoamed resin molded product (unfoamed molded product), a batch method may be used in which the unfoamed resin molded product is impregnated with high-pressure gas and foamed by releasing the pressure, Alternatively, a continuous method may be used in which the resin composition is kneaded together with a high-pressure gas under pressure and molded, and simultaneously the pressure is released and molding and foaming are performed simultaneously.

  About the resin foam of this invention, the case where it manufactures by a batch system is demonstrated. In the batch method, first, an unfoamed resin molded body is produced when producing a resin foam, but the production method of the unfoamed resin molded body is not particularly limited. A method of molding using an extruder such as an extruder or a twin screw extruder; the resin composition is uniformly kneaded using a kneader equipped with blades such as a roller, a cam, a kneader, and a Banbury mold And a method of press molding to a predetermined thickness using a hot plate press; a method of molding a resin composition using an injection molding machine, and the like. Among these methods, it is preferable to select an appropriate method so that an unfoamed resin molded body having a desired shape and thickness can be obtained. In addition, the unfoamed resin molded body may be manufactured by other molding methods besides 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 are selected according to the application. For example, a sheet shape, a roll shape, a prism shape, a plate shape, and the like can be given. Next, the unfoamed resin molded body (molded body made of a resin composition) is placed in a pressure-resistant container (high-pressure container), and a high-pressure gas is injected (introduced). Gas impregnation step for impregnation, decompression step to release air pressure (usually up to atmospheric pressure) when impregnated with a sufficiently high pressure gas, and to generate cell nuclei in the unfoamed resin molded body. And bubbling through a heating step of growing bubble nuclei by heating. Note that bubble nuclei may be grown at room temperature without providing a heating step. After the bubbles are grown in this manner, if necessary, the resin foam is obtained by rapidly cooling with cold water or the like to fix the shape. The high-pressure gas may be introduced continuously or discontinuously. Furthermore, as a heating method for growing bubble nuclei, a known or conventional method such as a water bath, an oil bath, a hot roll, a hot air oven, a far infrared ray, a near infrared ray, or a microwave may be employed.

  That is, the resin foam of the present invention may be formed by impregnating a non-foamed molded article composed of the resin composition with a high-pressure gas and then foaming it through a pressure reducing step. Moreover, after impregnating the unfoamed molding comprised from the said resin composition with a high voltage | pressure gas, it may form by further heating through the process of pressure-reducing.

  On the other hand, as a case of manufacturing in a continuous system, for example, a resin composition is injected (introduced) with high-pressure gas while kneading using an extruder such as a single-screw extruder or a twin-screw extruder, The kneading impregnation process in which the resin composition is sufficiently impregnated into the resin composition, the pressure is released by extruding the resin composition through a die provided at the tip of the extruder (usually up to atmospheric pressure), and molding and foaming simultaneously It may be produced by a molding decompression step to be performed. In some cases (if necessary), a heating step of growing bubbles by heating may be provided. After the bubbles are grown in this manner, if necessary, the resin foam is obtained by rapidly cooling with cold water or the like to fix the shape. 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 may be formed by impregnating a molten resin composition with a high-pressure gas and then foaming it through a pressure reducing process. In addition, the resin foam of the present invention may be formed by impregnating a molten resin composition with a high-pressure gas and then further heating it through a step of reducing the pressure.

  In the gas impregnation step in the batch method and the kneading impregnation step in the continuous method, the mixing amount of the gas is not particularly limited, but is preferably 1 to 10% by weight, more preferably 2%, based on the total amount of the resin composition, for example. ~ 8% by weight.

  In the gas impregnation step in the batch method or the kneading impregnation step in the continuous method, the pressure when impregnating the unfoamed resin molded article or the resin composition with a high-pressure gas is preferably 3 MPa or more (for example, 3 to 100 MPa), More preferably, it is 4 MPa or more (for example, 4 to 100 MPa). When the pressure of the gas is lower than 3 MPa, the bubble growth during foaming is remarkable, the bubble diameter becomes too large, and disadvantages such as, for example, a decrease in the dustproof effect are likely to occur, which is not preferable. This is because, when the pressure is low, the amount of gas impregnation is relatively small compared to when the pressure is high, and the number of bubble nuclei formed is reduced due to a decrease in the bubble nucleus formation rate. This is because the bubble diameter becomes extremely large. Further, in the pressure region lower than 3 MPa, the bubble diameter and the bubble density change greatly only by slightly changing the impregnation pressure, so that it is difficult to control the bubble diameter and the bubble density.

  In addition, in the gas impregnation step in the batch method and the kneading impregnation step in the continuous method, the temperature when impregnating the unfoamed resin molded article or the polyester elastomer composition with the high-pressure gas can be selected within a wide range, but the operability and the like can be selected. When considered, 10 to 350 ° C. is preferable. For example, in a batch system, the impregnation temperature when impregnating a sheet-like unfoamed resin molded body with a high-pressure gas is preferably 40 to 300 ° C, more preferably 100 to 250 ° C. Moreover, in a continuous system, the temperature at the time of inject | pouring and kneading high pressure gas to a resin composition has preferable 150-300 degreeC, More preferably, it is 210-250 degreeC. When carbon dioxide is used as the high-pressure gas, the temperature during impregnation (impregnation temperature) is preferably 32 ° C. or higher (particularly 40 ° C. or higher) in order to maintain a supercritical state.

  In addition, in the said pressure reduction process, although the pressure reduction speed | rate is not specifically limited, In order to obtain a uniform fine bubble, 5-300 MPa / s is preferable. Moreover, the heating temperature in the said heating process is although it does not specifically limit, 40-250 degreeC is preferable, More preferably, it is 60-250 degreeC.

  Moreover, according to the said manufacturing method of a resin foam, since the resin foam of a high expansion ratio can be manufactured, a thick resin foam can be obtained. For example, in the case of producing a resin foam by the above continuous method, in order to maintain the pressure inside the extruder in the kneading impregnation step, the gap of the die attached to the tip of the extruder is as narrow as possible (usually 0.1 to 1.. 0 mm). Therefore, in order to obtain a thick resin foam, the resin composition extruded through a narrow gap must be foamed at a high magnification. Conventionally, a foam that is formed because a high foaming magnification cannot be obtained. Has been limited to a thin thickness (for example, 0.5 to 2.0 mm). On the other hand, according to the method for producing a resin foam produced using a high-pressure gas, it is possible to continuously obtain a resin foam having a final thickness of 0.30 to 5.00 mm. It is.

  Since the delamination strength of the resin foam of the present invention is not less than a specific value, the resin foam has excellent characteristics with respect to the carrier tape. For example, since foam destruction when peeling from the carrier tape can be effectively suppressed or prevented, the resin foam is hardly broken when the resin foam is peeled from the carrier tape.

  The resin foam of the present invention has a uniform and fine cell structure because the average cell diameter is within a specific range, the maximum cell diameter is not more than a specific value, and does not include coarse cells. For this reason, in the foam surface, the contact | adherence area with respect to a carrier tape can be enlarged, and also the strength of the foam surface is excellent. Therefore, since the resin foam of this invention is excellent in the sticking property with respect to a carrier tape, it is excellent in the conveyance property using a carrier tape, and the workability using a carrier tape. For example, it is possible to efficiently perform a series of operations in which the resin foam is processed in a state of being attached to the carrier tape and the processed resin foam is conveyed. Furthermore, since the resin foam of this invention is excellent in the sticking property with respect to a carrier tape, it is excellent in pick-up property. For example, it is possible to easily lift the resin foam by attaching a carrier tape to the resin foam. Also, when the resin foam is bonded to the pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer on one side of the release film, and then the carrier tape is bonded to the resin foam, the carrier tape is lifted to release the release film and the pressure-sensitive adhesive layer. The structure of a carrier tape, a resin foam, and an adhesive layer can be easily obtained.

  The resin foam of the present invention has a repulsive force at 50% compression within a specific range, an average cell diameter within a specific range, and a maximum cell diameter of a specific value or less. Has cell structure and excellent flexibility. For this reason, it is possible to follow a minute clearance.

  In the resin foam of the present invention, the average cell diameter is within a specific range, the maximum cell diameter is not more than a specific value, and does not include a coarse cell. Therefore, dust enters from the coarse cell, and the dustproof property decreases. It is difficult to cause the problem. The resin foam of the present invention is also excellent in dust resistance.

  The resin foam of the present invention is suitably used as a sealing material or dustproof material for electric equipment or electronic equipment. Further, it is suitably used as a shock absorbing material and a shock absorbing material, particularly as a shock absorbing material and a shock absorbing material for electric equipment or electronic equipment.

(Foamed member)
The resin foam of the present invention may be used as a foam member. That is, the said foaming member is a member containing said resin foam of this invention. For example, the foam member may be composed of only the resin foam of the present invention, or may have at least the resin foam and a surface layer.

  Although the shape of the said foaming member is not specifically limited, A sheet form (a film form is included) and a tape form are preferable. The foamed member may be processed so as to have a desired shape, thickness, and the like. For example, various shapes may be processed according to the device, equipment, casing, member, and the like used.

  Although it does not specifically limit as said surface layer, For example, a resin layer (polymer layer) is mentioned preferably from the point which improves the characteristic with respect to a carrier tape, and the point which improves a sealing performance. For example, the foamed member may be formed by laminating a resin layer 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. This is because when the polymer layer is a layer composed of a material different from the resin foam of the present invention, the physical properties of the resin foam may be changed.

  Moreover, when laminating the resin layer as the surface layer on the resin foam, the manufacturing process may be complicated. For example, when laminating a resin layer as a surface layer on a resin foam by applying a resin that forms a resin layer, welding a resin layer, or pasting a resin layer through an adhesive layer, workability and production May adversely affect sex.

  Therefore, the surface layer is more preferably a layer (heat-melted layer) formed by heat-melting treatment on the surface of the resin foam from the viewpoint of improving the properties of the carrier tape and improving the sealing property. preferable. According to the heat-melting treatment, it can be easily made the same as the composition of the resin foam, it is not necessary to consider compatibility with other materials, and it is advantageous in that the change in thickness is small. It is also advantageous in terms of workability.

  Although it does not specifically limit as said heat-melting process, For example, the press process by a hot roll, the laser irradiation process, the contact melting process on the heated roll, a flame | frame process etc. are mentioned.

  In the case of press treatment with a hot roll, the treatment can be suitably performed using a thermal laminator or the like. 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, but is 15 ° C. lower than the softening point or melting point of the resin constituting the resin foam (more preferably 14 ° C. lower than the softening point or melting point of the resin constituting the resin foam). More preferably, it is preferably at least 12 ° C. lower than the softening point or melting point of the resin constituting the resin foam, and more preferably 20 ° C. higher than the softening point or melting point of the resin constituting the resin foam (more preferably Is preferably at most 10 ° C. higher than the softening point or melting point of the resin constituting the resin foam. If the temperature during the heat-melting process is lower than a temperature lower by 15 ° C. than the softening point or melting point of the resin constituting the resin foam, the resin may not melt. On the other hand, if the temperature during the heat-melting treatment is higher than a temperature 20 ° C. higher than the softening point or melting point of the resin constituting the resin foam, the bubble structure may shrink and problems such as wrinkles may occur.

  The treatment time for the heat-melting treatment is preferably 0.1 seconds to 10 seconds, and preferably 0.5 seconds to 7 seconds, although it depends on the treatment temperature. If the time is too short, surface melting does not proceed and surface layer formation may be poor. On the other hand, if the time is too long, the resin foam may shrink and problems such as wrinkles may occur.

  Furthermore, as the surface layer, it is possible to provide a processing mount on the foamed member via an adhesive layer, and it is possible to fix or temporarily fix to an adherend (for example, a housing or a part). From the point to do, an adhesive layer is mentioned preferably.

  The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive (such as a natural rubber-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive), a silicone-based pressure-sensitive adhesive, or a polyester-based pressure-sensitive adhesive Examples thereof include an adhesive, a urethane-based adhesive, a polyamide-based adhesive, an epoxy-based adhesive, a vinyl alkyl ether-based adhesive, and a fluorine-based adhesive. An adhesive may be used individually or in combination of 2 or more types. The pressure-sensitive adhesive may be any form of pressure-sensitive adhesive such as an emulsion-based pressure-sensitive adhesive, a solvent-based pressure-sensitive adhesive, a hot-melt pressure-sensitive adhesive, an oligomer-based pressure-sensitive adhesive, or a solid-type pressure-sensitive adhesive. Among these, as the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of preventing contamination of the adherend. That is, the foam member preferably has an acrylic pressure-sensitive adhesive layer on the resin foam of the present invention.

  Although the thickness of the said adhesive layer is not specifically limited, 2-100 micrometers is preferable, More preferably, it is 10-100 micrometers. The thinner the pressure-sensitive adhesive layer, the higher the effect of preventing the adhesion of dust and dirt at the end, so the thinner the adhesive layer is preferable. The pressure-sensitive adhesive layer may have either a single layer or a laminate.

  The said foaming member WHEREIN: The said adhesive layer may be provided through the other layer (lower layer). Examples of such a lower layer include other pressure-sensitive adhesive layers, intermediate layers, undercoat layers, and base material layers (particularly film layers and nonwoven fabric layers). Furthermore, the pressure-sensitive adhesive layer may be protected by a release film (separator) (for example, release paper, release film, etc.).

  Furthermore, the foamed member has a sealing property and excellent characteristics with respect to the carrier tape, and can be fixed or temporarily fixed. It may have a heat-melt treated layer) and a pressure-sensitive adhesive layer (particularly an acrylic pressure-sensitive adhesive layer). For example, the foam member has the resin layer (particularly a heat-melted treatment layer formed by heat-melting treatment) on one side of a sheet-like resin foam, and an adhesive layer (particularly on the other side). An acrylic pressure-sensitive adhesive layer).

  Since the said foaming member contains the resin foam of said this invention, it is excellent in a softness | flexibility. Moreover, it has the flexibility which can follow a minute clearance. Furthermore, it is excellent in dust resistance.

  Moreover, since the said foaming member contains the resin foam of said this invention, it is excellent in the characteristic with respect to a carrier tape. For example, it is excellent in the sticking property to a carrier tape and the peelability from a carrier tape. Moreover, it is excellent in the conveyance property and workability using a carrier tape.

  Since the foamed member has the characteristics as described above, it is suitably used as a member used when various members or parts are attached (attached) to a predetermined site. In particular, the foamed member is suitably used as a member used when attaching (attaching) a component constituting the electrical or electronic device to a predetermined site in the electrical or electronic device.

  That is, the foam member is suitably used for electric or electronic equipment. That is, the foamed member may be a foamed member for electric or electronic equipment.

  Various members or components that can be attached (mounted) using the foamed member are not particularly limited, and for example, various members or components in electrical or electronic devices are preferably exemplified. Examples of such a member or component for electric or electronic equipment include an image display member (display unit) (particularly a small image display member) mounted on an image display device such as a liquid crystal display, an electroluminescence display, or a plasma display. ), Optical members or optical parts such as cameras and lenses (particularly small cameras and lenses) that are mounted on mobile communication devices such as so-called “mobile phones” and “portable information terminals”.

  As a preferable usage mode of the foamed member of the present invention, for example, around the display unit such as LCD (liquid crystal display) or the display unit and the housing such as LCD (liquid crystal display) for the purpose of dust prevention, light shielding, buffering, etc. And a window portion).

(Foamed member laminate)
The foamed member laminate of the present invention is at least composed of the foamed member (member containing the resin foam of the present invention) and a carrier tape (particularly a carrier tape having an adhesive layer on at least one side of the substrate). And the foamed member is held by a carrier tape.

  Thus, since the said foaming member laminated body has the structure by which the said foaming member was stuck on the adhesive surface of the carrier tape, in the state which made the said foaming member stick on the adhesive surface on a carrier tape, In addition, when the foamed member is used, the foamed member can be easily peeled off from the carrier tape while suppressing or preventing foam breakage.

  Although the carrier tape is not particularly limited, it has at least one pressure-sensitive adhesive layer, and exhibits sufficient adhesive strength (adhesive strength) to hold the foamed member during processing or transportation of the foamed member. On the other hand, when the foamed member is peeled off, it is important that the adhesive force (adhesive force) that can be easily peeled can be exhibited without destroying the surface.

  Therefore, as said carrier tape, the adhesive tape (adhesive tape or sheet | seat) which has the adhesive layer by an adhesive is mentioned. In particular, from the viewpoint of achieving both adhesiveness and releasability with the foamed member, an acrylic pressure-sensitive adhesive (especially an acrylic pressure-sensitive adhesive based on an acrylic polymer having a main monomer component of alkyl (meth) acrylate) as a base polymer) An acrylic pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (acrylic pressure-sensitive adhesive layer) is preferably exemplified. Such a pressure-sensitive adhesive tape is either a pressure-sensitive adhesive tape with a base material in which a pressure-sensitive adhesive layer is formed on at least one surface side of the base material, or a base-less pressure-sensitive adhesive tape having a structure formed only by the pressure-sensitive adhesive layer. Although it may have, it is preferable that it is an adhesive tape with a base material from the point of a handleability or workability | operativity.

  In the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, examples of the pressure-sensitive adhesive other than the acrylic pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives (natural rubber-based pressure-sensitive adhesives, synthetic rubber-based pressure-sensitive adhesives), silicone-based pressure-sensitive adhesives, and polyesters. Adhesives, urethane adhesives, polyamide adhesives, epoxy adhesives, vinyl alkyl ether adhesives, fluorine adhesives, and the like. You may use an adhesive individually or in combination of 2 or more types. The pressure-sensitive adhesive may be any type of pressure-sensitive adhesive such as an emulsion-based pressure-sensitive adhesive, a solvent-based pressure-sensitive adhesive, a hot-melt pressure-sensitive adhesive, an oligomer-based pressure-sensitive adhesive, and a solid-type pressure-sensitive adhesive.

  In addition, the base material in the adhesive tape is not particularly limited, but, for example, a plastic base material such as a plastic film or sheet; a paper base material such as paper; a fiber base material such as cloth, nonwoven fabric, or net; a metal Metal base materials such as foil and metal plates; rubber base materials such as rubber sheets; foams such as foam sheets, and laminates thereof (particularly laminates of plastic base materials and other base materials, An appropriate thin leaf body such as a laminate of plastic films (or sheets) and the like can be mentioned.

  In addition, the thickness of the base material in the adhesive tape as a carrier tape, an adhesive layer, etc. are not specifically limited.

  According to the said foaming member laminated body, after processing a foaming member so that it may become a predetermined shape, a foaming member can be peeled from a carrier tape, and the foaming member which has a predetermined 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 foam destruction, maintains a good cell structure, and is processed into a predetermined shape . Therefore, the foamed member obtained after processing using the foamed member laminate is a sealing material, a dustproof material, a cushioning material, and an impact absorber that are used when various members or parts are attached (attached) to a predetermined site. It is preferably used as a material. In particular, the foamed member can be suitably used even when a small member or component is mounted on a thin product.

(Electric or electronic equipment)
The electric or electronic equipment of the present invention has the foam member (member including the resin foam of the present invention). That is, the electrical or electronic equipment of the present invention has a configuration in which the foamed member is used. In electrical or electronic equipment, the foamed member is used as, for example, a dustproof material, a seal material, a shock absorber, a buffer material, or the like. Such electric or electronic devices have a configuration in which members or parts for electric or electronic devices are attached (attached) to a predetermined site via the foamed member. Specifically, as an electric or electronic device, an image display device such as a liquid crystal display, an electroluminescence display, a plasma display or the like as an optical member or component (particularly, an image in which a small image display member is mounted as an optical member) Display device), a camera or a lens (especially a small camera or lens), or an electric or electronic device (for example, a so-called "portable" Mobile communication devices such as “telephone” and “portable information terminal”). Such electrical or electronic devices may be products that are thinner than before, and the thickness and shape thereof are not particularly limited.

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

Example 1
Block copolymer of polybutylene terephthalate as a hard segment and polyether as a soft segment (trade name “Perprene P-90BD”, manufactured by Toyobo Co., Ltd., 230 ° C. melt flow rate: 3.0 g / 10 min, melting point: 204 ° C.): 100 parts by weight, acrylic lubricant (trade name “Metablene L-1000”, manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, hard clay surface-treated with a silane coupling agent (trade name “ST” -301 ", manufactured by Shiraishi Calcium Co., Ltd .: 1 part by weight, carbon black (trade name" Asahi # 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): 50000, epoxy equivalent: 1200 g / eq, viscosity: 2850 mPa · s): 2 parts by weight were kneaded with a twin-screw kneader at a temperature of 220 ° C., then extruded into strands, cooled with water, cut into pellets, and molded.
The pellets were put into a single screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an atmosphere of 240 ° C. After sufficiently saturating the carbon dioxide gas, it was cooled to a temperature suitable for foaming and extruded from a die to obtain a sheet-like polyester elastomer foam having a thickness of 2.0 mm.

(Example 2)
Using a thermal laminator (apparatus name “MRK-6504”, manufactured by MCK Co., Ltd.) capable of adjusting the roll gap, the polyester elastomer foam produced in Example 1 was gap: 0.95 mm, roll temperature: 190 ° C., Treatment temperature: Surface heat melting treatment was carried out under the condition of 12 m / min to obtain a polyester elastomer foam having a surface layer.

(Example 3)
Block copolymer of polybutylene terephthalate as a hard segment and polyether as a soft segment (trade name “Perprene P-90BD”, manufactured by Toyobo Co., Ltd., 230 ° C. melt flow rate: 3.0 g / 10 min, melting point: 204 ° C.): 100 parts by weight, acrylic lubricant (trade name “METABBRENE L-1000”, manufactured by Mitsubishi Rayon Co., Ltd.): 1 part by weight, hard clay surface-treated with a silane coupling agent (trade name “ST” -301 ", manufactured by Shiraishi Calcium Co., Ltd .: 1 part by weight, carbon black (trade name" Asahi # 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): 50000, epoxy equivalent: 1200 g / eq, viscosity: 2850 mPa · s): 2 parts by weight were kneaded with a twin-screw kneader at a temperature of 220 ° C., then extruded into strands, cooled with water, cut into pellets, and molded.
The pellets were put into a single screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an atmosphere of 240 ° C. After sufficiently saturating the carbon dioxide gas, it was cooled to a temperature suitable for foaming and extruded from a die to obtain a sheet-like polyester elastomer foam having a thickness of 2.0 mm.

(Example 4)
Block copolymer of polybutylene terephthalate as a hard segment and polyether as a soft segment (trade name “Perprene P-90BD”, manufactured by Toyobo Co., Ltd., 230 ° C. melt flow rate: 3.0 g / 10 min, melting point: 204 ° C.): 100 parts by weight, acrylic lubricant (trade name “Metablene L-1000”, manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, hard clay surface-treated with a silane coupling agent (trade name “ST” -301 ", manufactured by Shiraishi Calcium Co., Ltd .: 3 parts by weight, carbon black (trade name" Asahi # 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): 50000, epoxy equivalent: 1200 g / eq, viscosity: 2850 mPa · s): 2 parts by weight were kneaded with a twin-screw kneader at a temperature of 220 ° C., then extruded into strands, cooled with water, cut into pellets, and molded. The pellets were put into a single screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MPa in an atmosphere of 240 ° C. The carbon dioxide gas was sufficiently saturated, cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-like polyester elastomer foam having a thickness of 1.5 mm.

(Comparative Example 1)
Block copolymer of polybutylene terephthalate as a hard segment and polyether as a soft segment (trade name “Hytrel 5577”, manufactured by Toray DuPont Co., Ltd., 230 ° C. melt flow rate: 1.8 g / 10 min, melting point 208 ° C.): 100 parts by weight, acrylic lubricant (trade name “Metablene L-1000”, manufactured by Mitsubishi Rayon Co., Ltd.): 5 parts by weight, polypropylene (trade name “Newstrain SH9000”, manufactured by Nippon Polypro Co., Ltd.): 1 weight Parts, magnesium hydroxide (average particle size: 0.7 μm): 1 part by weight, carbon black (trade name “Asahi # 35”, manufactured by 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, biaxially mixed The machine was kneaded at a temperature of 220 ° C., extruded in strands, was molded and cut into a water-cooled after pellets.
The pellets were put into a single screw extruder, and carbon dioxide gas was injected at a pressure of 17 (13 after injection) MP in an atmosphere of 240 ° C. The carbon dioxide gas was sufficiently saturated, cooled to a temperature suitable for foaming, and then extruded from a die to obtain a sheet-like 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 elastomer (melt flow rate (MFR): 6 g / 10 min): 55 parts by weight, polyethylene: 10 parts by weight, 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 with a twin-screw kneader at a temperature of 200 ° C. After being kneaded, the mixture was extruded into strands, cooled with water, and cut into pellets to obtain pellets.
This pellet was put into a single screw extruder manufactured by Nippon Steel Works, and carbon dioxide gas was injected in a 220 ° C. atmosphere at a pressure of 13 (12 after injection) MP. Carbon dioxide gas was injected at a ratio of 5% by weight with respect to the total amount of pellets. After sufficiently saturating the carbon dioxide gas, 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)
The main component is a commercially available polyurethane having an average cell diameter of 160 μm, a 50% compression rebound stress (50% repulsion load) of 0.7 N / cm ² , and an apparent density of 0.15 g / cm ^3. The foam was used.
This foam was a sheet and had a thickness of 1.0 mm.

(Evaluation)
About the Example and the comparative example, the following measurement or evaluation was performed. The results are shown in Table 1.

(Apparent density)
The foam was punched with a punching blade mold having a width of 20 mm and a length of 20 mm to obtain a sheet-like test piece. The dimensions of the test piece were measured with a caliper. Further, the thickness of the test piece was measured with a 1/100 dial gauge having a measurement terminal diameter (φ) of 20 mm. The volume of the test piece was calculated from these values. Next, the weight of the test piece was measured with an electronic balance. From the volume of the test piece and the weight of the test piece, the apparent density (g / cm ³ ) of the foam was calculated from the following formula.
Apparent density of foam (g / cm ³ ) = (weight of test piece) / (volume of test piece)

(Average cell diameter, maximum cell diameter)
By using a digital microscope (trade name “VHX-500”, manufactured by KEYENCE CORPORATION), an enlarged image of the foam bubble part is captured, and image analysis is performed using the analysis software of the measurement device, whereby the bubble diameter of each cell. (Μm) was determined, and the average cell diameter (μm) and the maximum cell diameter (μm) were determined. The number of bubbles in the captured enlarged image is about 200. The cell diameter is obtained by calculating the equivalent area of the circle by obtaining the area of the cell.

(Delamination strength)
A sheet-like 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 for 24 hours in an atmosphere of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%. The pretreatment conditions conform to JIS Z 0237.
One adhesive surface of an adhesive tape (width: 20 mm, length: 120 mm, trade name “No. 5603”, manufactured by Nitto Denko Corporation, double-coated adhesive tape with substrate, substrate: PET substrate) is attached to a SUS plate (stainless steel). The adhesive tape was fixed on a SUS plate. Next, a test piece was affixed to the other adhesive surface of the adhesive tape fixed on the SUS plate, and pressure-bonded under conditions of a 2 kg roller and one reciprocation.
After crimping, using a tensile tester (device name “TCN-1kNB”, manufactured by Minebea Co., Ltd.), the test piece was peeled off from the adhesive tape under the conditions of a peel angle of 90 ° and a tensile speed of 0.3 m / min. The peel strength (N / 20 mm) at that time was measured. The measured peel strength was defined as the delamination strength.

(Repulsive force at 50% compression (Repulsive load at 50% compression, 50% compression load))
It measured according to the compression hardness measuring method described in JIS K 6767.
The foam was cut into a width of 30 mm and a length of 30 mm to obtain a sheet-like test piece. Next, when the test piece was compressed at a compression rate of 10 mm / min in the thickness direction until the compression rate became 50%, the stress (N) was converted per unit area (1 cm ² ) and the repulsive force ( N / cm ² ).

(Pickup property)
A sheet-like 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 for 24 hours in an atmosphere of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%. The pretreatment conditions conform to JIS Z 0237.
One surface of the test piece was coated with an adhesive tape A (width: 20 mm, length: 120 mm, trade name “No. 5603”, manufactured by Nitto Denko Corporation, double-coated adhesive tape with substrate, substrate: PET substrate). And fixed on a release paper treated with a silicone release agent. Next, a carrier tape (trade name “3164S”, manufactured by Kern) is bonded to the other surface of the test piece so that the test piece and the adhesive layer of the carrier tape are in contact with each other. And allowed to stand for 24 hours to obtain a sample for evaluation.
When the carrier tape of the evaluation sample was lifted by hand, peeling occurred at the interface between the release paper and the adhesive tape A in the evaluation sample, and a laminate of the carrier tape, the test piece, and the adhesive tape A could be obtained. The case was evaluated as “good” (◯). On the other hand, when the carrier tape of the evaluation sample is lifted by hand, peeling occurs at the interface between the test piece and the carrier tape in the evaluation sample, and a laminate of the carrier tape, the test piece, and the adhesive tape cannot be obtained. The case was evaluated as “bad” (×).

(Form destruction prevention)
A sheet-like 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 for 24 hours in an atmosphere of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%. The pretreatment conditions conform to JIS Z 0237.
Adhesive tape A (width: 20 mm, length: 120 mm, trade name “No. 5603”, manufactured by Nitto Denko Corporation, double-sided adhesive tape with substrate, substrate: PET substrate) is applied to one surface of the test piece. The test piece was fixed to a SUS plate (stainless steel plate). After fixing, a carrier tape (trade name “3164S”, manufactured by Kern) is bonded to the test piece on the SUS plate so that the test piece and the adhesive layer are in contact with each other. An evaluation sample was obtained after standing for a period of time.
The carrier tape of the sample for evaluation was quickly peeled by hand, the state of the test piece after peeling was visually observed, and evaluated according to the following evaluation criteria.
Good (O): No surface breakage of the test piece occurs.
Defect (x): Surface breakage of the test piece occurs.

(Reworkability)
A sheet-like 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 for 24 hours in an atmosphere of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%. The pretreatment conditions conform to JIS Z 0237.
Adhesive tape A (width: 10 mm, length: 120 mm, product name “No. 5603”, manufactured by Nitto Denko Corporation, double-sided adhesive tape with substrate, substrate: PET substrate) is applied to one surface of the test piece. The test piece was fixed to a SUS plate (stainless steel plate) by pressure bonding under the conditions of a 2 kg roller and 1 reciprocation.
The foam was peeled off from the foam with the adhesive tape by hand, the peeled state was visually confirmed, and the reworkability was evaluated based on whether or not breakage occurred between the layers of the resin foam.
Good (O): No interlaminar fracture of the foam occurs.
Defect (x): Interlayer fracture of the foam occurs.

(Melting tension)
For measuring the melt tension, a Capillary Extension Rheometer manufactured by Malvern was used, and a resin extruded at a constant speed of 8.8 mm / min from a capillary having a diameter of 2 mm and a length of 20 mm was taken out at a rate of 2 m / min. The tension at the time of take-off was taken as the melt tension.
In addition, the pellet before foam molding was used for the measurement. The temperature at the time of measurement was 10 ± 2 ° C. on the high temperature side from the melting point of the resin.

(Strain hardening degree)
For the measurement, pellets before foam molding were used. The pellet was formed into a sheet having a thickness of 1 mm using a heated hot plate press, and a sheet was obtained. A sample (length: 10 mm, width: 10 mm, thickness: 1 mm) was cut out from the sheet. .
From the above sample, the uniaxial elongation viscosity at a strain rate of 0.1 [1 / s] was measured using a uniaxial elongation viscometer (manufactured by TA Instruments). And the strain hardening degree was calculated | required from the following formula.
Degree of strain hardening = log η max / log η 0.2
(Ηmax indicates the extensional viscosity when the uniaxial extensional viscosity is the highest, and η0.2 indicates the extensional viscosity when the strain ε is 0.2.)
The temperature at the time of measurement was the melting point of the resin.

  In the examples, the delamination strength of the foam is 10 N / 20 mm or more, there is no coarse cell having a cell diameter of 200 μm or more, and the cell structure is uniform, so that it can be picked up by a carrier tape and foam breakage occurs. There was no problem. On the other hand, since the foam of Comparative Example 1 contains coarse cells, the ratio of the cell wall on the surface of the foam is small, the adhesiveness with the carrier tape is weak, and picking up with the carrier tape is difficult. In addition, the foams of Comparative Examples 2 and 3 have a low delamination strength, and thus have a poor foam destruction inhibiting property. For this reason, when the carrier tape was peeled off after applying the carrier tape to the foams of Comparative Examples 2 and 3, foam destruction of the foam occurred.

  The resin foam of the present invention is used for electric or electronic devices (for example, mobile phones, mobile terminals, smartphones, tablet computers (tablet PCs), digital cameras, video cameras, digital video cameras, personal computers, home appliances, etc.). It is done.

Claims (14)

A resin foam formed by foaming a resin composition containing at least a resin and an epoxy-modified polymer;
The resin constituting the resin foam is a thermoplastic resin,
The thermoplastic resin is polyester;
The delamination strength defined below is 10 N / 20 mm or more, the repulsive force at 50% compression is 0.1 to 4.0 N / cm ² , the average cell diameter is 10 to 200 μm, and the maximum cell diameter Is a resin foam characterized by having a thickness of 300 μm or less.
Interlaminar peel strength: A sheet-like resin foam is attached to an adhesive surface of an adhesive tape (trade name “No. 5603”, manufactured by Nitto Denko Corporation) in a 23 ° C. atmosphere, and is crimped under conditions of 2 kg roller and one reciprocation. Then, the peel strength when the resin foam was peeled from the adhesive tape under the conditions of a peel angle of 90 ° and a tensile speed of 0.3 m / min. Further, the resin foam of claim 1, wherein the apparent density of 0.01~0.20g / cm ^3. The resin foam according to claim 1 or 2, wherein the resin foam is formed through a step of reducing pressure after impregnating a resin composition with a high-pressure gas. The resin foam according to claim 3, wherein the gas is an inert gas. The resin foam according to claim 3 or 4, wherein the gas is carbon dioxide. The resin foam according to any one of claims 3 to 5, wherein the high-pressure gas is in a supercritical state. The foam member characterized by including the resin foam of any one of Claims 1-6. The foam member according to claim 7, further comprising a surface layer on the resin foam. The foamed member according to claim 8, wherein the surface layer is a layer formed by heat melting treatment of the surface of the resin foam. The foam member according to claim 8, wherein the surface layer is an adhesive layer. The foamed member according to claim 10, wherein the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer. The foamed member according to any one of claims 7 to 11, which is for electric or electronic equipment. A foamed member laminate, wherein the foamed member according to any one of claims 7 to 12 is held by a carrier tape having an adhesive layer on at least one side of a substrate. An electrical or electronic device comprising the foamed member according to any one of claims 7 to 12.