Composition, foamed molding, and masterbatch

Abstract

To provide a composition capable of reducing generation of deposit in the production of a foamed molding employing thermally expandable microspheres and a thermoplastic elastomer.SOLUTION: There is provided a composition comprising the following components (A) to (C): component (A) thermally expandable microspheres; component (B) at least one selected from an olefin-based polymer (b1) having an acid group, a viscosity of 3000 mPa s or less at 200°C as measured at a shear rate of 10(1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms; and component (C) a matrix component comprising a thermoplastic elastomer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition, a foamed molded article, and a masterbatch. [Background technology]

[0002] Conventionally, when foamed molded articles are produced by extrusion molding, injection molding, or the like, foaming components such as heat-expandable microspheres (also called heat-expandable microcapsules) and various chemical foaming agents are mixed with a resin component serving as a base material for molding. However, the foaming components used here tend to scatter, and even when mixed with the base material, the resin pellets and the foaming components tend to separate during feeding into a molding machine. Therefore, a method is being carried out in which a foaming component is kneaded with a base material or a base resin that can be kneaded with the base material, and a foam molding masterbatch is formed into a desired shape to produce a foam molded article.

[0003] For example, Patent Document 1 proposes a technology for a masterbatch containing thermally expandable microcapsules, a carrier resin, and a lubricant, in which the carrier resin contains 30 to 55% by weight of an olefin component. As a specific example, it discloses a masterbatch using an ethylene-vinyl acetate copolymer, which makes it possible to produce foamed molded articles that have excellent surface smoothness and little color unevenness while achieving high heat resistance and expansion ratio. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2014-070102 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when foam molding is performed using the masterbatch described in Patent Document 1 and a thermoplastic elastomer as the base resin, deposits called "smears" (seepage gunk), such as the base resin and expanded heat-expandable microspheres, form and accumulate near the die nozzle opening. Furthermore, if foam molding is performed continuously for a long period of time, the gunk may break off and become mixed into the molded product or adhere to the surface of the molded product, thereby degrading the physical properties and appearance of the molded product. Furthermore, the gunk must be removed at regular intervals, which reduces production efficiency.

[0006] Therefore, an object of the present invention is to provide a composition that can reduce the occurrence of resin deposits when a foamed molded article is produced using heat-expandable microspheres and a thermoplastic elastomer. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a composition containing a specific component, and have arrived at the present invention. That is, the present invention includes the following aspects.

[0008] <1> A composition comprising the following components (A) to (C): Component (A): Thermally expandable microspheres Component (B): At least one selected from an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms. Component (C): A matrix component containing a thermoplastic elastomer <2> The acid value of the polymer (b1) is 3 mgKOH / g or more. <1> The composition described in <3> the acidic group is at least one selected from a carboxyl group and a carboxylic anhydride group; <1> or <2> The composition described in <4> The polymer (b1) is at least one selected from a copolymer with maleic acid (anhydride) and a modified product of maleic acid (anhydride). <1> ~ <3> The composition according to any one of the preceding claims. <5> The polymer (b1) has an α-olefin structural unit having 3 to 80 carbon atoms. <1> ~ <4> The composition according to any one of the preceding claims. <6> the component (A) is heat-expandable microspheres having a shell containing a polymer and a blowing agent encapsulated in the shell and vaporized by heating, the polymer being a polymer of a polymerizable component containing at least one monomer selected from the group consisting of a nitrile monomer and a carboxyl group-containing monomer; <1> ~ <5> The composition according to any one of the preceding claims. <7> The content of the component (A) is 0.1 to 15 parts by weight relative to 100 parts by weight of the component (C), and the content of the component (B) is 0.01 to 5 parts by weight relative to 100 parts by weight of the component (C). <1> ~ <6> The composition according to any one of the above. <8> <1> ~ <7> 2. A foamed molded article obtained by molding the composition according to any one of the preceding items. <9> A masterbatch comprising the following components (A), (B) and (D): Component (A): Thermally expandable microspheres Component (B): At least one selected from an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms. Component (D): A base resin having a melting point lower than the expansion initiation temperature of component (A). [Effects of the Invention]

[0009] The composition of the present invention can reduce the occurrence of resin deposits during the production of foamed molded articles. The foamed molded article of the present invention has excellent appearance and is lightweight. The masterbatch of the present invention can reduce the occurrence of resin deposits during the production of foamed molded articles. DETAILED DESCRIPTION OF THE INVENTION

[0010] The composition of the present invention contains the following components (A) to (C). Component (A): Thermally expandable microspheres Component (B): At least one selected from an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms. Component (C): A matrix component containing a thermoplastic elastomer Each component will be described in detail below.

[0011] [Component (A)] The heat-expandable microspheres of component (A) exhibit heat expandability (the ability of the entire microspheres to expand upon heating) as a whole. The heat-expandable microspheres contain a polymer-containing shell and a blowing agent encapsulated in the shell and vaporized upon heating. Preferably, the heat-expandable microspheres have a core-shell structure consisting of a thermoplastic resin-containing shell and a core essentially containing a blowing agent. The polymer forming the outer shell of heat-expandable microspheres is preferably obtained by polymerizing a polymerizable component. The polymerizable component includes a monomer component and may include a crosslinking agent. The monomer component refers to a monomer having one polymerizable carbon-carbon double bond and capable of addition polymerization. The crosslinking agent refers to a monomer having at least two polymerizable carbon-carbon double bonds and capable of introducing a crosslinked structure into a thermoplastic resin.

[0012] The monomer component is not particularly limited, and examples thereof include nitrile monomers such as acrylonitrile, methacrylonitrile, fumaronitrile, and maleonitrile; vinyl halide monomers such as vinyl chloride; vinylidene halide monomers such as vinylidene chloride; vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl butyrate; unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, and cinnamic acid, and maleic acid, itaconic acid, fumaric acid, and citraconic acid. Carboxyl group-containing monomers such as unsaturated dicarboxylic acids such as maleic acid and chloromaleic acid, anhydrides of unsaturated dicarboxylic acids, and unsaturated dicarboxylic acid monoesters such as monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monomethyl itaconate, monoethyl itaconate, and monobutyl itaconate; methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate (meth)acrylic acid ester-based monomers such as acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate; (meth)acrylamide-based monomers such as acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide; maleimide-based monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; styrene-based monomers such as styrene and α-methylstyrene; ethylenically unsaturated monoolefin-based monomers such as ethylene, propylene, and isobutylene; vinyl ether-based monomers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl ketone-based monomers such as vinyl methyl ketone; N-vinyl-based monomers such as N-vinylcarbazole and N-vinylpyrrolidone; and vinyl naphthalene salts. The carboxyl group-containing monomer may have some or all of its carboxyl groups neutralized during or after polymerization.The above-mentioned monomer components may be used alone or in combination of two or more. Acrylic acid and methacrylic acid are sometimes collectively referred to as (meth)acrylic acid, and acrylate and methacrylate are sometimes collectively referred to as (meth)acrylate. Furthermore, (meth)acrylate means acrylate or methacrylate, and (meth)acrylic means acrylic or methacrylic.

[0013] The polymerizable component is not particularly limited, but it is preferable that the monomer component contains at least one selected from nitrile monomers and carboxyl group-containing monomers, as this improves heat resistance. When the polymerizable component contains at least one monomer selected from the group consisting of nitrile monomers and carboxyl group-containing monomers, the weight ratio of the at least one monomer selected from the group consisting of nitrile monomers and carboxyl group-containing monomers in the polymerizable component is not particularly limited, but is preferably 25 to 100% by weight, more preferably 30 to 99.9% by weight, even more preferably 40 to 95% by weight, particularly preferably 45 to 90% by weight, and most preferably 50 to 85% by weight. A weight ratio of 25% by weight or more tends to improve the expandability of heat-expandable microspheres. When the polymerizable component contains a nitrile monomer or a carboxyl group-containing monomer as a monomer component, the weight ratio of the nitrile monomer or the carboxyl group-containing monomer in the polymerizable component is preferably within the above-mentioned numerical range.

[0014] The nitrile monomer preferably contains at least one selected from acrylonitrile and methacrylonitrile, as this improves heat resistance and solvent resistance. The weight proportion of acrylonitrile in the nitrile monomers is not particularly limited, but is preferably 0 to 90% by weight, more preferably 10 to 80% by weight, still more preferably 20 to 70% by weight, and particularly preferably 30 to 65% by weight. The weight proportion of methacrylonitrile in the nitrile monomers is not particularly limited, but is preferably 10 to 100% by weight, more preferably 20 to 90% by weight, still more preferably 30 to 80% by weight, and particularly preferably 35 to 70% by weight.

[0015] When the polymerizable component contains a nitrile monomer and a carboxyl group-containing monomer as monomer components, the weight ratio of the carboxyl group-containing monomer to the total of the nitrile monomer and the carboxyl group-containing monomer is not particularly limited, but is preferably 10 to 70 wt%, more preferably 15 to 60 wt%, even more preferably 20 to 55 wt%, and particularly preferably 25 to 50 wt%. When this weight ratio is 10 wt% or more, heat resistance tends to be improved. When this weight ratio is 70 wt% or less, the gas barrier properties of the outer shell tend to be improved.

[0016] When the polymerizable component contains a carboxyl group-containing monomer as a monomer component, the polymerizable component may further contain a monomer having a group reactive with a carboxyl group as a monomer component, which is preferable in that the heat resistance of the resulting heat-expandable microspheres is improved.

[0017] The group that reacts with a carboxyl group is not particularly limited, but examples thereof include a methylol group, a hydroxyl group, an amino group, an epoxy group, and an isocyanate group. Furthermore, the monomer having a group reactive with a carboxyl group is not particularly limited, and examples thereof include N-methylol(meth)acrylamide, N,N-dimethylaminoethyl(meth)acrylate, N,N-dimethylaminopropyl(meth)acrylate, vinyl glycidyl ether, propenyl glycidyl ether, glycidyl(meth)acrylate, glycerin mono(meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, and p-hydroxystyrene, and one or more of these may be used in combination.

[0018] The content of the monomer having a group reactive with a carboxyl group is not particularly limited, but is preferably 0.1 to 50 parts by weight, more preferably 0.3 to 40 parts by weight, even more preferably 0.5 to 30 parts by weight, and particularly preferably 1 to 20 parts by weight, relative to 100 parts by weight of the content of the carboxyl group-containing monomer. When the content is 0.1 part by weight or more, heat resistance tends to be improved. When the content is 50 parts by weight or less, expandability tends to be improved.

[0019] It is preferable that the polymerizable component contains vinylidene chloride as a monomer component, since this improves the gas barrier properties of the outer shell. The polymerizable component preferably contains, as a monomer component, at least one selected from the group consisting of a (meth)acrylic acid ester monomer not containing a group reactive with a carboxyl group and a styrene monomer not containing a group reactive with a carboxyl group, since this facilitates control of the thermal expansion properties of the heat-expandable microspheres. It is preferable that the polymerizable component contains, as a monomer component, a (meth)acrylamide-based monomer that does not contain a group that reacts with a carboxyl group, in terms of improving heat resistance. The weight proportion of at least one selected from vinylidene chloride, a (meth)acrylic acid ester monomer not containing a group reactive with a carboxyl group, a (meth)acrylamide monomer not containing a group reactive with a carboxyl group, and a styrene monomer not containing a group reactive with a carboxyl group in the polymerizable component is not particularly limited, but is preferably 70% by weight or less, more preferably 60% by weight or less, even more preferably 50% by weight or less, and particularly preferably 40% by weight or less.

[0020] As described above, the polymerizable component may contain a crosslinking agent. By using a crosslinking agent for polymerization, a decrease in the retention rate (encapsulation retention rate) of the contained blowing agent during thermal expansion is suppressed, and thermal expansion can be performed effectively. The crosslinking agent is not particularly limited, and examples thereof include aromatic divinyl compounds such as divinylbenzene; allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, PEG#200 di(meth)acrylate, PEG#600 di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 2-butyl-2-ethyl-1,3-propanediol diacrylate, and these may be used alone or in combination of two or more.

[0021] The polymerizable component does not need to contain a crosslinking agent, and the weight ratio of the crosslinking agent in the polymerizable component is not particularly limited, but is preferably 0 to 5 wt %, more preferably 0.05 to 2 wt %, even more preferably 0.1 to 1 wt %, and particularly preferably 0.2 to 0.9 wt %.

[0022] The blowing agent contained in the heat-expandable microspheres is not particularly limited as long as it is a substance that vaporizes when heated. Examples of blowing agents include hydrocarbons having 3 to 13 carbon atoms, such as propane, (iso)butane, (iso)pentane, (iso)hexane, (iso)heptane, (iso)octane, (iso)nonane, (iso)decane, (iso)undecane, (iso)dodecane, and (iso)tridecane; hydrocarbons having more than 13 but not more than 20 carbon atoms, such as (iso)hexadecane and (iso)eicosane; hydrocarbons such as pseudocumene, petroleum ether, and petroleum fractions having an initial boiling point of 150 to 260°C and / or a distillation range of 70 to 360°C, such as normal paraffin and isoparaffin; halides of these hydrocarbons; fluorine-containing compounds such as hydrofluoroethers; tetraalkylsilanes; and compounds that thermally decompose to generate gas when heated. These blowing agents may be used alone or in combination. The foaming agent may be linear, branched, or alicyclic, and is preferably aliphatic.

[0023] The blowing agent is a substance that vaporizes when heated, and preferably contains a substance having a boiling point lower than the softening point of the shell, which generates sufficient vapor pressure for expansion at the expansion temperature of the heat-expandable microspheres and improves the expansion ratio. Among the above blowing agents, hydrocarbons with 8 or fewer carbon atoms are preferred.

[0024] The foaming agent may also contain a substance having a boiling point higher than the softening point of the shell. When a substance having a boiling point higher than the softening point of the shell is encapsulated as a foaming agent, the weight ratio of the substance having a boiling point higher than the softening point of the shell in the foaming agent is not particularly limited, but is preferably 95% by weight or less, more preferably 80% by weight or less, even more preferably 70% by weight or less, particularly preferably 65% ​​by weight or less, particularly more preferably 50% by weight or less, and most preferably 30% by weight or less. When the weight ratio is 95% by weight or less, the expansion ratio tends to be improved.

[0025] The content of the blowing agent is defined as the percentage of the weight of the blowing agent encapsulated in the heat-expandable microspheres relative to the weight of the heat-expandable microspheres. The content of the blowing agent is not particularly limited, but is preferably 1 to 50%, more preferably 5 to 40% by weight, and even more preferably 10 to 30% by weight. When the weight percentage is within the above range, the expandability and heat resistance of the heat-expandable microspheres tend to be improved.

[0026] The average particle size of the heat-expandable microspheres is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 50 μm, even more preferably 5 to 40 μm, and particularly preferably 10 to 30 μm. When the average particle size is 1 μm or more, the expansion performance tends to be improved. When the average particle size is 100 μm or less, the appearance of the resulting foamed molded article tends to be good. The average particle size of the heat-expandable microspheres is measured by the method described in the Examples.

[0027] The expansion initiation temperature (Ts) of the heat-expandable microspheres is not particularly limited, but is preferably 120 to 200° C., more preferably 120 to 190° C., even more preferably 130 to 180° C., and particularly preferably 140 to 170° C. When the expansion initiation temperature is within the above range, foamed molded articles with a high expansion ratio tend to be stably produced. The maximum expansion temperature (Tmax) of the heat-expandable microspheres is not particularly limited, but is preferably 170 to 250° C., more preferably 180 to 230° C., and even more preferably 190 to 220° C. When the maximum expansion temperature is within the above range, expanded molded articles with a high expansion ratio tend to be stably produced. The expansion initiation temperature and maximum expansion temperature of the heat-expandable microspheres are measured by the methods described in the Examples.

[0028] A typical method for producing component (A) includes a step of polymerizing the polymerizable component in an aqueous dispersion medium containing the oily mixture containing the polymerizable component and the blowing agent as described above. The polymerizable component is preferably polymerized in the presence of a polymerization initiator.

[0029] [Component (B)] Component (B) is at least one selected from an olefin polymer (b1) (hereinafter sometimes referred to as polymer (b1)) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) (hereinafter sometimes referred to as fatty acid (b2)) having 20 or more carbon atoms. Component (B) has a structure of polar and non-polar parts, which allows for the adjustment of the compatibility between component (A) and component (C), which will be described later. Furthermore, the properties of the polymer (b1) and the fatty acid (b2) prevent the composition from losing its melting properties. This is thought to reduce the occurrence of scum during the production of foamed molded articles.

[0030] (Olefin polymer (b1)) The polymer (b1) has an acidic group. The acidic group is not particularly limited, but examples thereof include a carboxyl group, a carboxylic acid anhydride group, a sulfonic acid group, a phosphoric acid group, etc., and one or more of these groups may be present. The acidic group is not particularly limited, but at least one selected from a carboxyl group and a carboxylic acid anhydride group is preferred in terms of improving the compatibility between component (A) and component (C).

[0031] Furthermore, the polymer (b1) contains the largest number of structural units derived from an olefin monomer (hereinafter, sometimes referred to as olefin structural units). The weight ratio of the olefin structural unit in the polymer (b1) is not particularly limited, but is preferably 60% by weight or more, more preferably 65% ​​by weight or more, and even more preferably 70% by weight or more. When the weight ratio is 60% by weight or more, the melting properties of the composition tend to be easily controlled. Examples of olefin monomers include ethylene, propylene, and butylene.

[0032] The polymer (b1) is not particularly limited, but preferably has an α-olefin structural unit having 3 to 80 carbon atoms in its molecule, since this makes it easier to control the melting properties of the composition and further reduces the occurrence of gum. The number of carbon atoms is more preferably 3 to 70, and even more preferably 3 to 60.

[0033] The weight proportion of the α-olefin structural unit having 3 to 80 carbon atoms in the polymer (b1) is not particularly limited, but is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more. When the weight proportion is 50% by weight or more, the melting properties of the composition tend to be easily controlled.

[0034] The polymer (b1) is preferably at least one selected from a copolymer with a monomer having an acidic group and a modified product with a monomer having an acidic group, in terms of achieving the effects of the present invention. The monomer having an acidic group is not particularly limited, but examples thereof include unsaturated carboxylic acid monomers, unsaturated sulfonic acid monomers, and unsaturated phosphoric acid monomers, and one or more of these may be used in combination. The carboxylic acid monomer is not particularly limited, and examples thereof include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, methylmaleic acid, and methylfumaric acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, glutaconic acid, and norbornane-5-ene-2,3-dicarboxylic acid; and anhydrides of unsaturated dicarboxylic acids such as maleic anhydride, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride. The sulfonic acid monomer is not particularly limited, but examples thereof include Nt-butylacrylamidosulfonic acid. The phosphoric acid monomer is not particularly limited, but examples thereof include vinylphosphonic acid. The monomer having an acidic group is not particularly limited, but is preferably at least one selected from maleic anhydride and maleic acid in order to achieve the effects of the present invention. Furthermore, the polymer (b1) is not particularly limited, but is preferably at least one selected from a copolymer with maleic acid (anhydride) and a modified maleic acid (anhydride) in order to achieve the effects of the present invention. In the present invention, maleic acid (anhydride) refers to maleic acid or maleic anhydride.

[0035] The weight ratio of the structural units derived from the monomer having an acidic group in the copolymer with the monomer having an acidic group is not particularly limited, but is preferably 15 to 40% by weight, more preferably 20 to 35% by weight, and even more preferably 20 to 30% by weight. When the weight ratio is 15% by weight or more, the occurrence of eye gunk tends to be further reduced. When the weight ratio is 40% by weight or less, the melting properties of the composition tend to be easily controlled.

[0036] The copolymer with a monomer having an acidic group may have structural units other than the olefin structural unit and the structural unit derived from the monomer having an acidic group. The monomer that forms the other structural unit by polymerization reaction is not particularly limited, and examples thereof include (meth)acrylic acid ester monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and glycidyl (meth)acrylate; ethylene; propylene; alicyclic olefin monomers such as cyclohexene, vinylcyclohexane, and norbornene; diene monomers such as butadiene, isoprene, hexadiene, cyclopentadiene, dicyclopentadiene, and divinylbenzene; aromatic vinyl monomers such as styrene; and nitrile monomers such as acrylonitrile and methacrylonitrile.

[0037] The melting point of the polymer (b1) is 50°C or higher. If the melting point is lower than 50°C, the melting properties of the composition will be poor, making it difficult to reduce the occurrence of gunk. The melting point is preferably 50 to 160°C, more preferably 55 to 140°C, even more preferably 60 to 130°C, and particularly preferably 70 to 120°C.

[0038] The viscosity of polymer (b1) measured at a shear rate of 10 (1 / s) at a temperature of 200°C is 3000 mPa·s or less. If the viscosity exceeds 3000 mPa·s, the melting properties of the composition will be reduced, making it difficult to reduce the occurrence of gunk. The viscosity is preferably 10 to 2000 mPa·s, more preferably 15 to 1500 mPa·s, and even more preferably 20 to 1000 mPa·s. The viscosity of polymer (b1) measured at a shear rate of 10 (1 / s) at a temperature of 200°C is measured by the method described in the Examples.

[0039] The acid value of the polymer (b1) is not particularly limited, but is preferably 3 mgKOH / g or more. When the acid value is 3 mgKOH / g or more, the occurrence of gum tends to be further reduced. The acid value is more preferably 3 to 2500 mgKOH / g, even more preferably 5 to 1000 mgKOH / g, particularly preferably 10 to 500 mgKOH / g, and most preferably 20 to 200 mgKOH / g.

[0040] The weight-average molecular weight of the polymer (b1) is not particularly limited, but is preferably 1,000 to 200,000, more preferably 3,000 to 150,000, even more preferably 5,000 to 100,000, and particularly preferably 8,000 to 50,000. When the weight-average molecular weight is 1,000 or more, the heat resistance of the polymer (b1) is improved. When the weight-average molecular weight is 200,000 or less, the dispersibility of the polymer (b1) in the foam molded article tends to be improved. The weight-average molecular weight of polymer (b1) can be calculated using gel permeation chromatography (GPC). Specifically, when a solvent in which the compound is soluble, such as hexafluoroisopropanol, is used as the mobile phase and polymethyl methacrylate (PMMA) or polystyrene with known molecular weights is used as the standard substance, and when hexafluoroisopropanol is used as the column solvent, for example, Shodex GPC HFIP-806M or Shodex GPC HFIP-LG manufactured by Shimadzu GLC Co., Ltd. is used and a differential refractometer is used as the detector, the mass-average molecular weight can be measured.

[0041] (Fatty acids with 20 or more carbon atoms (b2)) The fatty acid (b2) has 20 or more carbon atoms, preferably 20 to 30 carbon atoms, more preferably 20 to 28 carbon atoms, even more preferably 20 to 26 carbon atoms, and particularly preferably 20 to 24 carbon atoms. The fatty acid (b2) is not particularly limited as long as it has 20 or more carbon atoms, and examples thereof include arachidic acid, mead acid, arachidonic acid, behenic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, and melissic acid. The fatty acid (b2) is not particularly limited, but is preferably a saturated fatty acid in that it exhibits the effects of the present invention.

[0042] [Component (C)] Component (C) is a matrix component containing a thermoplastic elastomer. Component (C) (matrix component) is a component that forms a foamed molded article. By including a thermoplastic elastomer in component (C), it is possible to obtain a lightweight foamed molded article with a wide range of processability. The component (C) does not include the polymer (b1).

[0043] Examples of the thermoplastic elastomer include olefin elastomers, styrene elastomers, polyurethane elastomers, polyamide elastomers, and polyester elastomers, and one or more of these may be used in combination. Examples of the olefin-based elastomer include a mixture of a polymer consisting of a hard segment and a polymer consisting of a soft segment, and a copolymer of a polymer consisting of a hard segment and a polymer consisting of a soft segment. In olefin-based elastomers, examples of hard segments include segments made of polypropylene. Examples of soft segments include segments made of polyethylene or copolymers of ethylene with a small amount of a diene component (e.g., ethylene-propylene copolymer (EPM), ethylene-propylene-diene copolymer (EPDM), and EPDM partially crosslinked by adding an organic peroxide). Polymer mixtures and copolymers serving as olefin-based elastomers may also be graft-modified with unsaturated hydroxy monomers and their derivatives, unsaturated carboxylic acid monomers and their derivatives, etc.

[0044] When the styrene-based elastomer is a block copolymer, the hard segment may be, for example, a segment made of polystyrene. Furthermore, the soft segment may be, for example, a segment made of polybutadiene, hydrogenated polybutadiene, polyisoprene, or hydrogenated polyisoprene. Examples of such styrene-based elastomers include block copolymers such as styrene-butadiene-styrene (SBS) copolymer, styrene-isoprene-styrene (SIS) copolymer, styrene-ethylene-butylene-styrene (SEBS) copolymer, styrene-ethylene-propylene-styrene (SEPS) copolymer, and styrene-butadiene-butylene-styrene (SBBS) copolymer.

[0045] When the polyester-based elastomer is a block copolymer, a lightweight foamed molded article tends to be obtained, and when the polyester-based elastomer is a polyether ester elastomer, the flexibility of the resulting foamed molded article tends to be improved. When the polyester elastomer is a block copolymer, it is preferably a block copolymer composed of a hard segment made of polybutylene terephthalate and a soft segment made of poly(polyoxyethylene) terephthalate. Here, the hard segment is a crystalline phase and contributes to high mechanical strength, heat distortion resistance, and good processability. On the other hand, the soft segment is an amorphous phase and contributes to flexibility, high impact absorption, and low-temperature properties. The content of the soft segment, which is poly(polyoxyethylene) terephthalate, in the polyester elastomer is not particularly limited, but is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, and even more preferably 15 to 85% by weight. The thermoplastic elastomer is not particularly limited, but is preferably at least one selected from olefin-based elastomers and styrene-based elastomers in order to more effectively achieve the effects of the present invention.

[0046] The melting point or softening point of component (C) is not particularly limited, but is preferably 100 to 200° C., more preferably 110 to 180° C., and even more preferably 120 to 160° C. When the melting point or softening point of component (C) is within the above range, a foamed molded article tends to be obtained stably.

[0047] The A hardness of component (C) is not particularly limited, but is preferably 5 to 98, more preferably 10 to 90, even more preferably 15 to 80, and most preferably 20 to 70. When the A hardness is within the above range, foamed molded articles tend to be obtained stably. The hardness of component (C) can be measured, for example, by a Type A durometer hardness test in accordance with JIS K6253 in an atmosphere of about 23°C.

[0048] The tensile strength of component (C) is not particularly limited, but is preferably 1 to 30 MPa, more preferably 1.5 to 30 MPa, and even more preferably 2 to 30 MPa. When the tensile strength is within the above range, foamed molded articles tend to be obtained stably. The tensile strength of component (C) can be measured, for example, by a method in accordance with JIS K6251.

[0049] The weight percentage of the thermoplastic elastomer in component (C) is not particularly limited, but is preferably 30 to 100% by weight, more preferably 50 to 100% by weight, even more preferably 60 to 100% by weight, and particularly preferably 70 to 100% by weight. A weight percentage of 30% or more allows sufficient expansion of the heat-expandable microspheres, tending to produce lightweight foamed molded articles. Component (C) may be a thermoplastic elastomer.

[0050] Component (C) may contain a substance other than a thermoplastic elastomer. The substance other than a thermoplastic elastomer is not particularly limited, but examples thereof include, but are not limited to, polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ionomer resins such as ethylene-based ionomers, urethane-based ionomers, styrene-based ionomers, and fluorine-based ionomers; polyolefin resins such as low-density polyethylene, high-density polyethylene, polypropylene, polybutene, polyisobutylene, ethylene-vinyl alcohol copolymers, ethylene-vinyl acetate copolymers, ethylene-methyl (meth)acrylate copolymers, ethylene-ethyl (meth)acrylate copolymers, ethylene-butyl (meth)acrylate copolymers, and polyterpenes; poly Examples of suitable resins include styrene-based resins such as styrene, styrene-acrylonitrile copolymer, and styrene-butadiene-acrylonitrile copolymer; polyacetal; polymethyl methacrylate; cellulose acetate; polycarbonate; polyester-based resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide-based resins such as nylon 6 and nylon 66; thermoplastic polyurethane; tetrafluoroethylene; polyacetal; polyphenylene sulfide; and bioplastics such as polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), and starch resin, and one or more of these may be used in combination.

[0051] [Composition and method for producing the composition] The composition of the present invention contains the components (A) to (C) as described above. The content of component (A) in the composition of the present invention is not particularly limited, but is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 10 parts by weight, even more preferably 1 to 8 parts by weight, and particularly preferably 1.5 to 6 parts by weight, per 100 parts by weight of component (C). A content of 0.1 part by weight or more tends to produce a lightweight foamed molded article. A content of 15 parts by weight or less tends to reduce the decrease in mechanical strength of the resulting foamed molded article.

[0052] The content of component (B) in the composition of the present invention is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.04 to 3 parts by weight, even more preferably 0.07 to 2 parts by weight, and particularly preferably 0.1 to 1.5 parts by weight, per 100 parts by weight of component (C). When the content is 0.01 part by weight or more, the occurrence of eye gunk tends to be reduced. When the content is 5 parts by weight or less, the appearance of the resulting foamed molded article tends to be improved.

[0053] The composition of the present invention may contain other components in addition to components (A) to (C), such as chemical foaming agents, stabilizers, modifiers, and fillers. The chemical foaming agent is not particularly limited, but examples include inorganic chemical foaming agents such as ammonium carbonate, sodium bicarbonate, and anhydrous sodium nitrate; and organic chemical foaming agents such as dinitrosopentamethylenetetramine, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, benzenesulfonylhydrazide, p,p'-oxybis(benzenesulfonylhydrazide), and azodicarboxamide. These chemical foaming agents may also be used in combination with foaming assistants such as urea-based, organic acid-based, and metal salt-based. These chemical foaming agents and foaming assistants may be used alone or in combination.

[0054] The stabilizer is not particularly limited, and examples thereof include phenolic stabilizers such as pentaerythrityl-tetrakis-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], phosphorus-based stabilizers such as tris(mononylphenyl)phosphite and tris(2,4-di-t-butylphenyl)phosphite, and sulfur-based stabilizers such as dilauroyl dipropionate, and the like, and one or more of these may be used in combination.

[0055] The modifier is not particularly limited, but examples thereof include sodium, calcium, magnesium, and the like salts of fatty acids such as lauric acid, palmitic acid, oleic acid, and stearic acid, and one or more of these may be used in combination. The modifier is any agent other than component (B).

[0056] Examples of the filler include inorganic fillers and organic fillers. The inorganic filler is not particularly limited, and examples thereof include glass fibers (including those coated with metal), carbon fibers (including those coated with metal), potassium titanate, silicon carbide, silicon nitride, ceramic fibers, metal fibers, aramid fibers, barium sulfate, calcium sulfate, calcium silicate, calcium carbonate, magnesium carbonate, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, magnesium hydroxide, aluminum hydroxide, mica, talc, kaolin, pyrophyllite, bentonite, sericite, zeolite, wollastonite, alumina, clay, ferrite, graphite, gypsum, glass beads, glass balloons, and quartz. The organic filler is not particularly limited, but examples thereof include vegetable fibers such as cellulose, kenaf, and bran; animal fibers such as wool and silk; synthetic fibers such as aramid fibers, phenolic fibers, polyester fibers, acrylic fibers, polyolefin fibers such as polyethylene and polypropylene, polyvinyl alcohol fibers, polyvinyl chloride fibers, and fluororesin fibers; regenerated fibers such as rayon; semi-synthetic fibers such as cellulose acetate; wood flour; soybean pulp; rice husks; monosaccharides; polysaccharides such as starch; etc. These fillers may be used alone or in combination of two or more.

[0057] Examples of methods for producing the composition of the present invention include mixing using mixing equipment such as a kneader, roll, mixing roll, mixer, single-screw extruder, twin-screw extruder, multi-screw extruder, etc. When heating is performed during production of the composition of the present invention, it is preferable to produce the composition at a temperature lower than the expansion starting temperature of component (A), preferably at least 5°C lower, more preferably at least 10°C lower.

[0058] The composition of the present invention may be prepared by mixing a masterbatch containing the above components (A) and (B) with the above component (C).

[0059] (Masterbatch) The masterbatch that can be used to prepare the composition of the present invention contains the above-mentioned components (A) and (B) and the following component (D). Use of the masterbatch enables components (A), (B), and (C) to be mixed efficiently during molding. Component (D): A base resin having a melting point equal to or lower than the expansion initiation temperature of the heat-expandable microspheres (component (A)). The component (D) does not include the polymer (b1).

[0060] The melting point of component (D) is not particularly limited as long as it is equal to or lower than the expansion onset temperature of heat-expandable microspheres (component (A)). However, it is preferably at least 5°C lower than the expansion onset temperature of component (A), more preferably at least 10°C lower than the expansion onset temperature of component (A), and even more preferably at least 20°C lower than the expansion onset temperature of component (A). The melting point of component (D) is not particularly limited, but is preferably 50 to 180°C, more preferably 55 to 160°C, even more preferably 60 to 140°C, and particularly preferably 65 to 120°C. When the melting point is 50°C or higher, the composition tends to be able to be stably supplied during the production of foamed molded articles. When the melting point is 180°C or lower, excessive thermal history of component (A) during the production of foamed molded articles can be suppressed, and lightweight foamed molded articles tend to be obtained.

[0061] The melt flow rate (hereinafter sometimes simply referred to as MFR) of component (D) is not particularly limited, but is preferably 0.5 to 2200 g / 10 min, more preferably 1 to 1500 g / 10 min, 5 to 1000 g / 10 min, particularly preferably 7 to 500 g / 10 min, and most preferably 10 to 250 g / 10 min. When the MFR is within the above range, the handleability and expandability of the masterbatch tend to be improved. The MFR of component (D) is a value measured using a capillary rheometer in accordance with JIS K7210 under conditions of a measurement temperature of 190°C and a load of 2.16 kg.

[0062] Component (D) is not particularly limited, and examples thereof include olefin resins such as polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-(meth)acrylate copolymer, polypropylene, polyolefin, styrene-butadiene copolymer, styrene-isoprene copolymer, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin); polyvinyl chloride (PVC); acrylic resin; thermoplastic polyurethane; and polystyrene resin, and these may be used alone or in combination of two or more.

[0063] If component (D) is an olefin-based resin, it is preferable in terms of achieving the effects of the present invention. In addition, the content of the olefin component in the olefin resin is not particularly limited, but is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 30% by weight or more, and particularly preferably 50% by weight or more. When the content is 5% by weight or more, dispersibility in component (C) tends to be improved.

[0064] The weight percentage of component (A) in the masterbatch is not particularly limited, but is preferably 30 to 80% by weight, more preferably 40 to 70% by weight, and even more preferably 50 to 65% by weight. When the weight percentage is 30% by weight or more, the masterbatch can be produced stably and handleability tends to be improved. When the weight percentage is 80% by weight or less, the dispersibility of component (A) tends to be improved.

[0065] The weight percentage of component (B) in the masterbatch is not particularly limited, but is preferably 0.5 to 30% by weight, more preferably 1 to 20% by weight, even more preferably 3 to 15% by weight, and particularly preferably 5 to 15% by weight. If the weight percentage is 0.5% by weight or more, the generation of sludge tends to be reduced. If the weight percentage is 30% by weight or less, the handleability of the masterbatch tends to be improved. In addition to the above components (A), (B), and (D), the masterbatch may also contain the above component (C), a chemical foaming agent, a stabilizer, a modifier, a filler, and the like.

[0066] The cross-sectional shape of the masterbatch when cut perpendicular to its length direction is determined appropriately depending on the use of the masterbatch, and examples thereof include a circle, an ellipse, a polygon, a star, a hollow circle, etc. The length of the masterbatch is determined appropriately depending on the application, etc., but is preferably 1 to 10 mm, more preferably 1.5 to 5 mm, and even more preferably 2 to 4 mm. The length of the major axis of the cross section perpendicular to the length direction of the masterbatch is determined appropriately depending on the application, but is preferably 0.5 to 5 mm, more preferably 1 to 4 mm, and even more preferably 2 to 3.5 mm.

[0067] The specific gravity of the masterbatch is not particularly limited, but is preferably 0.60 to 1.5, more preferably 0.65 to 1.3, and even more preferably 0.7 to 1.2. When the specific gravity is within the above range, the expandability of component (A) is maintained, and a lightweight foamed molded article tends to be obtained. The specific gravity of the masterbatch is measured by the method described in the Examples.

[0068] The expansion ratio of the masterbatch is not particularly limited, but is preferably 5 to 120 times, more preferably 10 to 100 times, and even more preferably 15 to 75 times. When the expansion ratio is 5 times or more, a lightweight foamed molded article tends to be obtained. When the expansion ratio is 120 times or less, the appearance of the obtained foamed molded article tends to be improved.

[0069] The method for producing the masterbatch may be any method in which the above components (A), (B), and (D) are mixed with, as necessary, components other than components (A), (B), and (D), and a method in which these are uniformly dispersed is preferred. The method for producing the masterbatch includes, for example, a production method including a preliminary kneading step shown in (1) below and a pelletizing step shown in (2) below.

[0070] (1) A pre-kneading step in which component (D) is melt-kneaded in advance using a kneading machine such as a roll, kneader, pressure kneader, or Banbury mixer, and then components (A) and (B) and, if necessary, components other than components (A), (B), and (D) are added to the melt-kneaded mixture to prepare a pre-kneaded mixture. (2) Next, the resulting pre-kneaded mixture is fed into an extruder such as a single-screw extruder, twin-screw extruder, or multi-screw extruder, and the molten mixture is extruded to a desired diameter, followed by pelletization using a hot-cut pelletizer.

[0071] The masterbatch must be produced at a temperature lower than the expansion onset temperature of component (A), otherwise the heat-expandable microspheres will expand. To prevent the heat-expandable microspheres from expanding, the masterbatch is usually produced at a temperature that is preferably at least 5°C lower, more preferably at least 10°C lower, than the expansion onset temperature. When a masterbatch is used in producing the composition of the present invention, the above-mentioned mixing equipment may be used.

[0072] [Foam molded article] The foamed molded article of the present invention is obtained by molding the above-mentioned composition, and may be obtained by molding a composition that is a mixture of the above-mentioned masterbatch containing components (A), (B), and (D) and component (C). The method for producing the foamed molded article is not particularly limited, but examples include a method including a step of molding the above composition at a temperature close to the maximum expansion temperature of component (A) contained therein. The molding method is not particularly limited, but is preferably extrusion molding such as irregular molding. In addition to extrusion molding, other methods include injection molding, calendar molding, inflation molding, blow molding, kneading molding, compression molding, vacuum molding, and thermoforming.

[0073] The expansion ratio of the foamed molded article of the present invention is not particularly limited, but is preferably 1.2 to 3 times, more preferably 1.3 to 2.7 times. If the expansion ratio is 3 times or less, the decrease in strength of the obtained foamed molded article tends to be suppressed.

[0074] The average pore size inside the foamed molded article of the present invention is not particularly limited, but is preferably 20 to 300 μm, more preferably 30 to 200 μm, and even more preferably 40 to 150 μm. When the pore size is 20 μm or more, the foamed molded article tends to be lightweight. When the pore size is 300 μm or more, the foamed molded article tends to have a good appearance. [Example]

[0075] Examples of the heat-expandable microspheres of the present invention will now be described in detail. The present invention is not limited to these examples. In the following examples and comparative examples, "%" means "% by weight" and "parts" means "parts by weight" unless otherwise specified. Furthermore, in the following, heat-expandable microspheres will be referred to simply as "microspheres," the viscosity of component (B) (polymer (b1)) at 200°C measured at a shear rate of 10 (1 / s) will be referred to simply as "viscosity," the base resin will be referred to as "resin," and the matrix component will be referred to as "matrix."

[0076] [Measurement of average particle size and particle size distribution of heat-expandable microspheres] The average particle size and particle size distribution were measured using a laser diffraction scattering particle size distribution analyzer (MT3000II) manufactured by Microtrack Bell Co., Ltd. The D50 value determined by volume-based measurement was used as the average particle size.

[0077] [Expansion starting temperature (Ts) and maximum expansion temperature (Tmax) of heat-expandable microspheres] A DMA (DMA Q800, manufactured by TA Instruments) was used as the measurement device. 0.5 mg of microspheres was placed in an aluminum cup with a diameter of 6.0 mm and a depth of 4.8 mm, and an aluminum lid (diameter 5.6 mm, thickness 0.1 mm) was placed on top of the microsphere layer to prepare a sample. The sample height was measured while a force of 0.01 N was applied from above using a pressure probe. The sample was heated from 20°C to 350°C at a heating rate of 10°C / min while a force of 0.01 N was applied using the pressure probe, and the displacement of the pressure probe in the vertical direction was measured. The temperature at which displacement in the forward direction began was defined as the expansion onset temperature (Ts), and the temperature at which the maximum displacement occurred was defined as the maximum expansion temperature (Tmax).

[0078] [Viscosity of polymer (b1) measured at a shear rate of 10 (1 / s) at a temperature of 200°C] A rheometer (HAAKE MARS 40, manufactured by ThermoFisher Scientific) was used as the measuring device. The heating plate in the device was set to 200°C, and polymer (b1) was placed between a parallel plate (diameter 25 mm) arranged parallel to the heating plate and melted, with a gap between the plates of 0.5 mm. Thereafter, the viscosity of polymer (b1) was measured at a shear rate of 10 (1 / s) and a temperature of 200°C.

[0079] [Measurement of specific gravity of foam molded product] Measurements were performed using a Shimadzu top-pan electronic analytical balance (AX200, manufactured by Shimadzu Corporation) in solid specific gravity measurement mode (immersion method).

[0080] [Measurement of specific gravity of masterbatch] The specific gravity of the masterbatch was measured using the following measurement method. The specific gravity was measured by the immersion method (Archimedes method) using isopropyl alcohol in an atmosphere with an ambient temperature of 25°C and a relative humidity of 50%. Specifically, a 100 mL volumetric flask was emptied and dried, and the weight of the volumetric flask (WB1) was then measured. The weighed volumetric flask was then filled with isopropyl alcohol exactly up to the meniscus, and the weight of the volumetric flask filled with 100 mL of isopropyl alcohol (WB2) was then measured. The 100 mL volumetric flask was also emptied and dried, and the weight of the volumetric flask (WS1) was then measured. Approximately 50 mL of the masterbatch was then filled into the weighed volumetric flask, and the weight of the volumetric flask filled with the masterbatch (WS2) was then measured. The volumetric flask filled with the masterbatch was then filled with isopropyl alcohol exactly up to the meniscus, taking care not to trap air bubbles, and the weight (WS3) was then measured. The obtained WB1, WB2, WS1, WS2, and WS3 were then introduced into the following formula to calculate the specific gravity (d) of the masterbatch. d={(WS2-WS1)×(WB2-WB1) / 100} / {(WB2-WB1)-(WS3-WS2)}

[0081] [Measurement and evaluation of eye mucus amount] The composition was extruded using a Labo Plastomill (ME-25, single-screw extruder manufactured by Toyo Seiki Co., Ltd.) and a strand die (nozzle diameter 3.0 mm) as a mold to obtain a foamed molded article. The raw material composition was charged into the extruder and extrusion from the strand die was started 5 minutes later, and the extrusion was continued for 30 minutes. Under the above molding conditions, the weight of the resin deposited near the discharge port of the strand die was measured, and the measured weight of the resin was evaluated based on the following index, with a score of ◯ or higher being considered a pass. ◎: The amount of eye mucus was 25 mg or less, which was good. ○: The amount of eye mucus is more than 25 mg and less than 50 mg, which is somewhat good. ×: The amount of eye mucus exceeded 50 mg, and the result was poor.

[0082] <Production Example A1> An aqueous dispersion medium was prepared by adding 60 parts of sodium chloride, 21 parts of colloidal silica containing 20% ​​active ingredient, 0.4 parts of polyvinylpyrrolidone, and 0.2 parts of ethylenediaminetetraacetic acid tetrasodium salt to 230 parts of ion-exchanged water and adjusting the pH to 3.0. Separately, 46 parts of acrylonitrile, 13 parts of methacrylonitrile, 36 parts of methacrylic acid, 2 parts of styrene, 3 parts of methacrylamide, 0.4 parts of 1,9-nonanediol diacrylate, 2 parts of di(2-ethylhexyl)peroxydicarbonate (P-OPP), 15 parts of isopentane, and 15 parts of isooctane were mixed to prepare an oily mixture. The aqueous dispersion medium and the oil mixture were mixed, and the resulting mixture was dispersed in a Clearmix (M Technic Co., Ltd.) at 10,000 rpm for 1 minute to prepare a suspension. The suspension was transferred to a 1.5-liter pressure reactor and purged with nitrogen. The initial reaction pressure was adjusted to 0.3 MPa, and the mixture was stirred at 100 rpm while undergoing polymerization at 60°C for 15 hours. After polymerization, the product was filtered and dried to obtain microspheres 1. The physical properties of the resulting heat-expandable microspheres are shown in Table 1.

[0083] <Manufacturing Examples A2 and A3> Heat-expandable microspheres were obtained in the same manner as in Production Example A1, except for changing the reaction conditions as shown in Table 1. The physical properties of the obtained heat-expandable microspheres are shown in Table 1. The abbreviations in Table 1 have the following meanings: GMA: Glycidyl methacrylate 4EG-A:PEG200#diacrylate 1,9ND-A: 1,9-nonanediol diacrylate

[0084] [Table 1]

[0085] <Manufacturing example B1> Forty parts of the microspheres 1 obtained in Production Example A1, 45 parts of Resin D-1 (ethylene-vinyl acetate copolymer, Ultrathene 720 manufactured by Tosoh Corporation, specific gravity 0.95, melting point 67°C), and 15 parts of Copolymer B-1 (a copolymer having maleic anhydride structural units and multiple α-olefin structural units with carbon atoms of 28 to 58, melting point 72°C, acid value 103 mgKOH / g) were mixed and kneaded in a pressure kneader at 80°C for 1 minute. The kneaded mixture was extruded at 70°C and shaped into pellets to obtain masterbatch (MB1). The physical properties of the resulting masterbatch are shown in Table 2.

[0086] <Manufacturing example B2~26> Each masterbatch was obtained in the same manner as in Production Example B1, except that the compounding conditions and production conditions for the masterbatch in Production Example B1 were changed to those shown in Tables 2 to 4. The physical properties of the obtained masterbatches are shown in Tables 2 to 4. The abbreviations in Tables 2 to 7 have the following meanings. B1-1: A copolymer containing maleic anhydride structural units and multiple α-olefin structural units with carbon atoms of 28 to 58. The content of maleic anhydride structural units in the copolymer is 21% by weight, the melting point is 72°C, the acid value is 103 mgKOH / g, and the viscosity is 26 mPa·s. B1-2: Maleic anhydride modified polypropylene, melting point 136°C, acid value 3.5 mg KOH / g, viscosity 60 mPa·s B1-3: Maleic anhydride modified polypropylene, melting point 135°C, acid value 52 mg KOH / g, viscosity 1300 mPa·s B1-4: Maleic anhydride modified polypropylene, melting point 142°C, acid value 39 mg KOH / g, viscosity 2600 mPa·s B2-1: Behenic acid b-1: stearic acid b-2: Polyethylene wax, melting point 130°C, acid value 0mgKOH / g b-3: Maleic anhydride modified polypropylene, melting point 124°C, acid value 19 mg KOH / g, viscosity 3500 mPa·s D-1: Ethylene-vinyl acetate copolymer, Ultrathene 720 manufactured by Tosoh Corporation, specific gravity 0.95, melting point 67°C D-2: Ethylene-methyl methacrylate copolymer, manufactured by Sumitomo Chemical Co., Ltd., Acryft WK402, specific gravity 0.94, melting point 79°C

[0087] [Table 2]

[0088] [Table 3]

[0089] [Table 4]

[0090] Example 1 Five parts of the masterbatch MB1 obtained in Production Example B1 were mixed with 95 parts of Matrix C-1 (olefin-based elastomer, Milastomer® 8032BS manufactured by Mitsui Chemicals, Inc., specific gravity 0.89, hardness A 79, tensile strength 6.8 MPa) to obtain a composition. The resulting composition was extrusion-molded using the extruder and strand die described in the "Measurement and Evaluation of Residue Amount" section above to obtain a strand-shaped foamed molded article. The physical properties of the resulting foamed molded article are shown in Table 4. The molding conditions were as follows: the temperature (molding temperature) of the cylinder and strand die of the extruder was set to 210°C, and the screw rotation speed was set to 25 rpm. The residence time of the composition in the molding machine was 3.5 minutes.

[0091] <Examples 2 to 19 and Comparative Examples 1 to 9> Except for changing the production conditions for the foam molded article of Example 1 to those shown in Tables 4 and 5, foam molded articles were obtained in the same manner as in Example 1. The physical properties of the obtained foam molded articles are shown in Tables 4 and 5. The abbreviations in Tables 4 and 5 have the following meanings. C-1: Olefin elastomer, manufactured by Mitsui Chemicals, Inc., Milastomer (registered trademark) 8032BS, specific gravity 0.89, A hardness 79, tensile strength 6.8 MPa C-2: Styrene-based elastomer, Aronkasei Co., Ltd. AR-SC-30, specific gravity 0.89, A hardness 23, tensile strength 3.7 MPa

[0092] [Table 5]

[0093] [Table 6]

[0094] [Table 7]

[0095] As can be seen from Tables 5 to 7, a composition comprising heat-expandable microspheres (component (A)), at least one selected from the group consisting of an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms (component (B)), and a matrix component (component (C)) containing a thermoplastic elastomer can reduce the occurrence of eye gunk. On the other hand, it is clear that the composition not containing component (B) was unable to reduce the occurrence of eye gunk. [Industrial Applicability]

[0096] The composition of the present invention can be used for foam molding such as injection molding, extrusion molding, and press molding, and can be used to produce foam molded articles that are excellent in sealing properties, sound insulation properties, heat insulation properties, heat insulation properties, sound absorption properties, appearance, etc.

Claims

1. A composition comprising the following components (A) to (C): Component (A): thermally expandable microspheres Component (B): At least one selected from an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms. Component (C): A matrix component containing a thermoplastic elastomer

2. The composition according to claim 1, wherein the acid value of the polymer (b1) is 3 mg KOH / g or more.

3. The composition according to claim 1 or 2, wherein the acidic group is at least one selected from a carboxyl group and a carboxylic anhydride group.

4. The composition according to claim 1 or 2, wherein the polymer (b1) is at least one selected from the group consisting of a copolymer with maleic acid (anhydride) and a modified product of maleic acid (anhydride).

5. The composition according to claim 1 or 2, wherein the polymer (b1) has an α-olefin structural unit having 3 to 80 carbon atoms.

6. 3. The composition according to claim 1, wherein the component (A) is heat-expandable microspheres comprising an outer shell containing a polymer and a blowing agent encapsulated in the outer shell and vaporized by heating, and the polymer is a polymer of a polymerizable component containing at least one monomer selected from the group consisting of a nitrile monomer and a carboxyl group-containing monomer.

7. The composition according to claim 1 or 2, wherein the content of the component (A) is 0.1 to 15 parts by weight per 100 parts by weight of the component (C), and the content of the component (B) is 0.01 to 5 parts by weight per 100 parts by weight of the component (C).

8. A foamed molded article obtained by molding the composition according to claim 1 or 2.

9. A masterbatch comprising the following components (A), (B) and (D): Component (A): thermally expandable microspheres Component (B): At least one selected from an olefin polymer (b1) having an acidic group, a viscosity of 3000 mPa·s or less at 200°C measured at a shear rate of 10 (1 / s), and a melting point of 50°C or higher, and a fatty acid (b2) having 20 or more carbon atoms. Component (D): A base resin having a melting point lower than the expansion initiation temperature of component (A).

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