Resin composition, molded article, and usage of said article

Abstract

This resin composition contains a thermoplastic resin (A) and a fatty acid ester (B). The contained amount of the fatty acid ester (B) is 10 to 90 parts by mass per 100 parts by mass of the thermoplastic resin (A). The thermoplastic resin (A) contains at least one selected from the group consisting of an ethylene-vinyl acetate copolymer (A1) and an olefin-based elastomer (A2). In addition, the melting point of the main component of the thermoplastic resin (A) is 55°C or higher.

Description

Resin composition, molded article, and its use

[0001] This invention relates to resin compositions, molded articles, and their applications.

[0002] Conventionally, there is a concept of adding a phase transition material with a large heat capacity to resin, which makes it difficult for the temperature to change even in the high temperatures of midsummer or the low temperatures of midwinter, and makes it difficult to feel hot or cold when touched. This is due to the mechanism by which energy is expended during the phase transition (solid → liquid, liquid → solid), and by maintaining the temperature at the phase transition temperature for a certain period of time, it is possible to slow down the rise or fall of temperature. Examples based on this concept include sheets that give a cooling sensation and materials that suppress the temperature rise of steering wheels and instrument panels in cars that become hot in the summer.

[0003] Patent Document 1 discloses a resin composition containing the above-mentioned phase transition material, comprising a thermoplastic resin having a crystalline heat of fusion amount (ΔHm) of 100 J / g or less, and a heat-storing microcapsule, wherein the crystalline heat of fusion amount (ΔHm) is 50 J / g or more, and is a heat-storing resin composition.

[0004] Japanese Patent Publication No. 2019-116570

[0005] In inventions such as those described in Patent Document 1, microcapsules are easily destroyed by physical or thermal stimuli. As a result, the capsules may break during molding, causing the phase transition material inside to leak out and leading to bleed-out. In particular, if the molecular weight of the phase transition material is low, bleed-out is more likely to occur, and the decrease in heat retention is likely to be significant.

[0006] The present invention aims to provide a resin composition that can be easily manufactured by granulation or batch kneading, exhibits excellent moldability by pressing, allows for temperature control, and has excellent bleed resistance.

[0007] The inventors of the present invention conducted diligent research to solve the above problems. As a result, they found that the above problems can be solved by a resin composition containing a specific thermoplastic resin and a fatty acid ester in specific amounts, and thus completed the present invention. Examples of embodiments of the present invention are shown below.

[0008] [1] A resin composition comprising 100 parts by mass of a thermoplastic resin (A) and 10 to 90 parts by mass of a fatty acid ester (B), wherein the thermoplastic resin (A) comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer (A1) and olefin-based elastomer (A2), and the melting point of the main component of the thermoplastic resin (A) is 55°C or higher.

[0009] [2] The resin composition according to item [1], wherein the thermoplastic resin (A) comprises the ethylene vinyl acetate copolymer (A1), and the fatty acid ester (B) comprises a fatty acid ester (B1) having a heat of fusion of crystals (ΔHm) of 225 J / g or less.

[0010] [3] The resin composition according to item [2], wherein the fatty acid ester (B1) comprises methyl stearate.

[0011] [4] The resin composition according to any one of items [1] to [3], wherein the thermoplastic resin (A) further comprises 2 to 30% by mass of a propylene polymer (A3) (with the total thermoplastic resin (A) being 100% by mass).

[0012] [5] The resin composition according to any one of items [1] to [4], wherein the thermoplastic resin (A) further comprises 1 to 10% by mass of a modified propylene polymer (A4) (the total amount of the thermoplastic resin (A) is 100% by mass).

[0013] [6] The resin composition according to item [5], wherein the melt flow rate of the modified propylene polymer (A4) (according to ASTM D1238, 230°C, 2.16 kg load) is 25 g / 10 min or more.

[0014] [7] The resin composition according to item [5] or [6], wherein the modified propylene polymer (A4) comprises a modified product obtained by modifying an unsaturated carboxylic acid or a derivative thereof, and the degree of modification is 0.1% by mass to 5.0% by mass.

[0015] [8] The resin composition according to any one of items [1], [4] to [7], wherein the thermoplastic resin (A) comprises the olefin-based elastomer (A2), and the fatty acid ester (B) comprises a fatty acid ester (B2) having a heat of fusion of crystals (ΔHm) of more than 225 J / g.

[0016] [9] The resin composition according to item [8], wherein the fatty acid ester (B2) comprises at least one selected from the group consisting of stearyl stearate, myristyl myristate, and cetyl myristate.

[0017]

[10] The resin composition according to any one of items [1] to [9], wherein the value of the Hansen distance parameter in the olefin elastomer (A2) that is derived from the intermolecular dispersion force is less than 17.2.

[0018]

[11] The resin composition according to any one of items [1] to

[10] , further comprising a porous inorganic compound (C) in an amount greater than 0 parts by mass and less than 1.5 parts by mass.

[0019]

[12] A molded article made from the resin composition described in any one of items [1] to

[11] .

[13] A building material made from the resin composition described in any one of items [1] to

[11] .

[14] A pillow filler made from the resin composition described in any one of items [1] to

[11] .

[0020] The resin composition of the present invention can be easily manufactured by granulation or batch kneading, exhibits excellent moldability by pressing, allows for temperature control, and has excellent bleed resistance.

[0021] The present invention will now be described in detail. [Resin Composition] The resin composition according to the present invention (hereinafter also referred to as "this composition") comprises 100 parts by mass of a thermoplastic resin (A) and 10 to 90 parts by mass of a fatty acid ester (B), wherein the thermoplastic resin (A) comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer (A1) and olefin-based elastomer (A2), and the melting point of the main component of the thermoplastic resin (A) is 55°C or higher.

[0022] A first embodiment of the composition (hereinafter also referred to as "the first composition") comprises the ethylene vinyl acetate copolymer (A1) as the thermoplastic resin (A), and a fatty acid ester (B1) having a heat of fusion of crystals (ΔHm) of 225 J / g or less as the fatty acid ester (B).

[0023] Furthermore, a second embodiment of the composition (hereinafter also referred to as "the second composition") includes the olefin-based elastomer (A2) as the thermoplastic resin (A), and also includes a fatty acid ester (B2) having a heat of fusion (ΔHm) of more than 225 J / g.

[0024] <Thermoplastic resin (A)> The thermoplastic resin (A) used in the present invention comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer (A1) and olefin-based elastomer (A2), and the melting point of the main component of the thermoplastic resin (A) is 55°C or higher.

[0025] The melting point of the main component of the thermoplastic resin (A) is preferably 60 to 150°C, more preferably 65 to 120°C. Having the melting point within this range results in excellent dimensional stability of the composition. Here, the main component of the thermoplastic resin (A) in this invention refers to the component with the highest proportion in the thermoplastic resin (A).

[0026] <<Ethylene-vinyl acetate copolymer (A1)>> The ethylene-vinyl acetate copolymer (A1) used in the present invention is not particularly limited, but from the viewpoint of odor and heat resistance, the vinyl acetate content (hereinafter also referred to as "VA content") is preferably 10% by mass or more, more preferably 10 to 40% by mass, and even more preferably 15 to 35% by mass.

[0027] Furthermore, the ethylene-vinyl acetate copolymer (A1) has a melt flow rate (MFR) measured in accordance with JIS K7210:1999 at 190°C and a 2.16 kg load, preferably 20 g / 10 min or less, more preferably 0.1 to 18 g / 10 min, and even more preferably 0.5 to 16 g / 10 min. When the MFR of component (A1) is within this range, the moldability of the composition is excellent.

[0028] ≪Olefin-based elastomer (A2)≫ The olefin-based elastomer (A2) used in the present invention is not particularly limited, but examples include copolymers of ethylene and α-olefins having 3 to 20 carbon atoms; copolymers of ethylene and α-olefins having 3 to 20 carbon atoms and cyclic olefins; ethylene-based copolymers using various vinyl compounds such as styrene, vinyl acetate, (meth)acrylic acid, and (meth)acrylic acid esters as comonomers; copolymers of propylene and α-olefins having 4 to 20 carbon atoms; and copolymers of propylene and α-olefins having 4 to 20 carbon atoms and cyclic olefins.

[0029] Another example of an olefin-based elastomer (A2) is a copolymer of at least one selected from the group consisting of polyethylene and polypropylene and at least one selected from the group consisting of polybutadiene, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, polyisobutylene, and α-olefin. The copolymerization can be either block copolymerization or graft copolymerization, but in the case of a copolymer consisting of one selected from the group consisting of polyethylene and polypropylene and an α-olefin, the copolymerization can be random copolymerization.

[0030] Further examples of olefin-based elastomers (A2) include blends of at least one selected from the group consisting of polyethylene and polypropylene, and at least one selected from the group consisting of ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-butene copolymer, and hydrogenated styrene-butadiene. The ethylene-propylene copolymer, ethylene-propylene-diene copolymer, and ethylene-butene copolymer may be partially or completely crosslinked.

[0031] As the olefin-based elastomer (A2), a propylene-based elastomer mainly composed of propylene is preferred. The propylene-based elastomer preferably contains 50 mol% or more, more preferably 52 to 95 mol%, and even more preferably 55 to 90 mol%, of structural units derived from propylene, from the viewpoint of affinity with fatty acid esters.

[0032] The melt flow rate (MFR) of the olefin-based elastomer (A2) measured at 190°C under a 2.16 kg load in accordance with JIS K7210:1999 is preferably 20 g / 10 min or less, more preferably 0.1 to 15 g / 10 min, and still more preferably 0.2 to 10 g / 10 min. When the MFR of the component (A2) is within the above range, the resulting composition will have excellent moldability.

[0033] The olefin-based elastomer (A2) has a heat of crystal fusion ΔHm of preferably 50 J / g or less, more preferably 0.1 to 40 J / g, and still more preferably 1 to 30 J / g. When the heat of crystal fusion ΔHm falls within such a range, the fatty acid ester is less prone to bleed out.

[0034] In the olefin-based elastomer (A2), the value derived from intermolecular dispersion force of the Hansen distance parameter is preferably less than 17.2, more preferably 1 to 17.1, and still more preferably 5 to 17.0. When the value falls within such a range, the affinity with the fatty acid ester is increased, making bleed-out less likely to occur.

[0035] Here, the Hansen distance parameter refers to the solubility parameter (SP value: δ) introduced by Hildebrand, which is divided into three components: a dispersion term δ Ｄ , a polar term δ Ｐ , and a hydrogen bonding term δ Ｈ , expressed in a three-dimensional space. It is a parameter that takes into account the polarity of a substance, and the relationship represented by the following formula holds. δ[(cal / cm ３ ) ０．５ = (δ Ｄ ２ + δ Ｐ ２ + δ Ｈ ２ ) ０．５

[0036] The above-mentioned dispersion term δ Ｄ , the polar term δ Ｐ , and the hydrogen bonding term δ Ｈhave been obtained in large numbers by Hansen and subsequent researchers (see, for example, VII-698 to 711 of *Polymer Handbook* (4th edition)). In addition, Hansen solubility parameters for many solvents and resins have been investigated (see, for example, *Industrial Solvents Handbook* by Wesley L. Archer). They can also be obtained using the software *Hansen Solubility Parameters in Practice* (HSPiP).

[0037] The thermoplastic resin (A) may contain thermoplastic resins other than the above-mentioned ethylene-vinyl acetate copolymer (A1) and olefin-based elastomer (A2). Examples of such other thermoplastic resins include olefin-based resins (excluding olefin-based elastomers (A2)), styrene-based resins, acrylic resins, polyester-based resins, polyvinyl chloride-based resins, polyamide-based resins, polycarbonate-based resins, polylactic acid-based resins, polyimide-based resins, polysulfone-based resins, aromatic polyketone-based resins, and resins obtained by modifying these. These resins may be used alone or in combination of two or more, and commercially available products may be used. Among these, olefin-based resins and resins obtained by modifying olefin-based resins are preferred, and propylene-based polymers (A3) and modified propylene-based polymers (A4) are more preferred.

[0038] <<Propylene-based Polymer (A3)>> There is no particular limitation on the propylene-based polymer (A3). For example, it may be a propylene homopolymer, a random copolymer of propylene and an α-olefin, or a block polypropylene (block PP). Among these, propylene homopolymer is preferred.

[0039] The propylene-based polymer (A3) is preferably a resin containing 50% by mass or more of structural units derived from propylene, based on all structural units. Further, the propylene-based polymer (A3) may be a composition containing two or more types of propylene-based polymers.

[0040] Examples of α-olefins in propylene-α-olefin random copolymers include ethylene and α-olefins having 4 to 20 carbon atoms. Specifically, examples of α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradodecene, 1-hexadodecene, 1-octadodecene, 1-eicosene, 4-methyl-1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, diethyl-1-butene, and trimethyl-1-butene. Examples include 3-methyl-1-pentene, ethyl-1-pentene, propyl-1-pentene, dimethyl-1-pentene, methylethyl-1-pentene, diethyl-1-hexene, trimethyl-1-pentene, 3-methyl-1-hexene, dimethyl-1-hexene, 3,5,5-trimethyl-1-hexene, methylethyl-1-heptene, trimethyl-1-heptene, ethyl-1-octene, and methyl-1-nonene.

[0041] One type of α-olefin having 4 to 20 carbon atoms may be used, or two or more types may be used in combination. As the α-olefin in the propylene-α-olefin random copolymer, ethylene and / or α-olefins having 4 to 12 carbon atoms are preferred.

[0042] The propylene homopolymer and the propylene-α-olefin random copolymer may be synthetic or commercially available products.

[0043] The propylene polymer (A3) has a melt flow rate (MFR) measured in accordance with JIS K7210:1999 at 190°C and a 2.16 kg load, preferably between 0.1 and 15 g / 10 min, and more preferably between 0.5 and 10 g / 10 min. The MFR of the propylene polymer (A3) being within this range results in excellent moldability of the composition.

[0044] The propylene polymer (A3) has a crystalline heat of fusion (ΔHm) measured using a differential scanning calorimeter, preferably 55 J / g or more, more preferably 60 to 100 J / g, and even more preferably 65 to 90 J / g. When the crystalline heat of fusion is within this range, bleed-out can be suppressed while improving the handling properties when the composition is molded.

[0045] When the thermoplastic resin (A) contains a propylene polymer (A3), its content is preferably 2 to 30% by mass, more preferably 3 to 28% by mass, and even more preferably 4 to 25% by mass, based on 100% by mass of the total thermoplastic resin (A). By having the propylene polymer (A3) content within the above range, bleed-out can be suppressed while improving the handling properties when the composition is molded.

[0046] <Modified propylene polymer (A4)> The modified propylene polymer (A4) preferably includes a modified product modified with an unsaturated carboxylic acid or its derivative.

[0047] The density of the modified propylene polymer (A4) is preferably 850 to 930 kg / m³. 3 More preferably 855-920 kg / m 3 More preferably 860 to 910 kg / m 3 That is the case.

[0048] The modified propylene polymer (A4) has a melt flow rate (MFR) measured in accordance with ASTM D1238 at 230°C and a 2.16 kg load, preferably 25 to 1000 g / 10 min, more preferably 30 to 500 g / 10 min, and even more preferably 40 to 200 g / 10 min. Having the MFR of the modified propylene polymer (A4) within this range results in excellent moldability of the composition.

[0049] Examples of propylene polymers before modification include those similar to those exemplified in the aforementioned propylene polymer (A3), and may also be compositions of two or more propylene polymers. When the propylene polymer before modification is a copolymer, it is usually a random copolymer.

[0050] Examples of the aforementioned unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.

[0051] Examples of the aforementioned derivatives include acid anhydrides such as maleic anhydride, endic acid anhydride (cis-5-norbornene-endo-2,3-dicarboxylic acid anhydride), itaconic anhydride, and citraconic anhydride; esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, monomethyl itaconic acid, and diethyl itaconic acid; amides such as acrylamide, methacrylamide, monoamide maleate, diamide maleate, N-monoethyl maleate, N-N-diethyl maleate, N-monobutylamide maleate, N-N-dibutylamide maleate, monoamide fumarate, diamide fumarate, N-monobutylamide fumarate, and N-N-dibutylamide fumarate; Examples include imides such as maleimide, N-butylmaleimide, and N-phenylmaleimide; and metal salts such as sodium acrylate, sodium methacrylate, potassium acrylate, and potassium methacrylate.

[0052] Among these unsaturated carboxylic acids and their derivatives, maleic acid and maleic anhydride are preferred, with maleic anhydride being more preferred. The modified propylene polymer (A4) may be used alone or in combination of two or more types.

[0053] Modification of propylene polymers with unsaturated carboxylic acids or their derivatives can be carried out by conventionally known methods. For example, a modified propylene polymer (A4) can be obtained by graft polymerization of an unmodified propylene polymer with an unsaturated carboxylic acid or its derivative (e.g., maleic acid or its anhydride) in the presence of a radical initiator.

[0054] Examples of radical initiators include organic peroxides, azo compounds, and metal hydrides. The radical initiator may be used directly mixed with the propylene polymer before modification, the unsaturated carboxylic acid or its derivative, and other optional components, or it may be dissolved in a small amount of organic solvent before use. This organic solvent is not particularly limited as long as it is capable of dissolving the radical initiator.

[0055] The degree of modification of the modified propylene polymer (A4) derived from the unsaturated carboxylic acid is preferably 0.1 to 5.0% by mass, more preferably 0.3 to 4.0% by mass. Having the degree of modification within this range suppresses bleed-out.

[0056] When the thermoplastic resin (A) contains a modified propylene polymer (A4), its content is preferably 1 to 10% by mass, more preferably 1.2 to 9% by mass, and even more preferably 1.5 to 8% by mass, based on 100% by mass of the entire thermoplastic resin (A). By having the content of the modified propylene polymer (A4) within the above range, bleed-out can be suppressed.

[0057] The polymer containing the thermoplastic resin (A) described above used in the present invention may also contain biomass-derived monomers (e.g., propylene, ethylene, and α-olefins) as monomers constituting the polymer. The monomers constituting the polymer may consist only of biomass-derived monomers, or may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers are monomers made from any renewable natural raw materials and their residues, including fungi, yeasts, algae, and bacteria, which are plant-derived or animal-derived, and which contain carbon 14 10 C isotopes -12 It contains a certain proportion, and the biomass carbon concentration (pMC) measured according to ASTM D 6866 is approximately 100 pMC. Biomass-derived monomers are obtained by conventionally known methods.

[0058] It is preferable from the viewpoint of reducing environmental impact (mainly greenhouse gas reduction) that the polymer used in the present invention contains biomass-derived monomers. If the polymer production conditions such as polymerization catalyst, polymerization process, and polymerization temperature are equivalent, even if the raw material monomer contains biomass-derived monomers, 14 10 C isotopes -12 ~10 -14 Aside from the small proportions it contains, its molecular structure is equivalent to that of polymers composed of fossil fuel-derived monomers. Therefore, its performance is considered to be the same.

[0059] The polymer used in the present invention may contain chemically recycled monomers (e.g., propylene, ethylene, and α-olefins). The monomers constituting the polymer may consist solely of chemically recycled monomers, or they may include chemically recycled monomers, fossil fuel-derived monomers, and / or biomass-derived monomers.

[0060] Chemically recycled monomers are obtained by conventionally known methods. It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the polymer used in the present invention contains chemically recycled monomers. Chemically recycled monomers are monomers obtained by depolymerizing polymers such as waste plastics, returning them to monomer units such as ethylene through depolymerization, thermal decomposition, etc., and monomers produced using said monomers as raw materials. Therefore, even if chemically recycled monomers are included as raw material monomers for the polymer used in the present invention, the molecular structure is equivalent to that of a polymer made from fossil fuel-derived monomers, provided that the polymer production conditions such as polymerization catalyst, polymerization process, and polymerization temperature are the same. Consequently, the performance is also considered to be unchanged.

[0061] <Fatty Acid Ester (B)> The fatty acid ester (B) used in the present invention is a compound used as a phase transition material, and examples include methyl stearate, butyl stearate, dodecyl stearate, stearyl stearate, isocetyl stearate, isotridecyl stearate, myristyl myristate, cetyl myristate, isocetyl myristate, octyldodecyl myristate, isocetyl isostearate, cetyl 2-ethylhexanoate, ethylhexyl palmitate, methyl palmitate, hexadecyl palmitate, and docosyl docosanoate.

[0062] The fatty acid ester (B1) used in the first composition has a heat of fusion (ΔHm) of 225 J / g or less, preferably 150 to 220 J / g, and more preferably 180 to 215 J / g. Examples of such fatty acid esters (B1) include methyl stearate, butyl stearate, dodecyl stearate, and methyl palmitate. Among these, methyl stearate is preferred from the viewpoint of suppressing bleed-out.

[0063] The fatty acid ester (B2) used in the second composition has a heat of fusion (ΔHm) of more than 225 J / g, preferably 226 to 300 J / g, and more preferably 227 to 280 J / g. Examples of such fatty acid esters (B2) include stearyl stearate, myristyl myristate, cetyl myristate, hexadecyl palmitate, and docosyl docosanate. Among these, stearyl stearate, myristyl myristate, and cetyl myristate are preferred from the viewpoint of suppressing bleed-out.

[0064] The fatty acid ester (B) can be selected as appropriate depending on the desired phase transition temperature (warming temperature), and may be used alone or in combination of two or more compounds.

[0065] <Porous inorganic compound (C)> This composition may also contain a porous inorganic compound (C) as a coating agent to suppress stickiness of the pellets.

[0066] The porous inorganic compound (C) is not particularly limited, but from the viewpoint of suppressing stickiness, examples include silica and alumina. These may be used individually or in combination of two or more. Among the above, silica is preferred, and hydrophobic silica is more preferred.

[0067] <Composition> In this composition, the content of each component is such that, per 100 parts by mass of thermoplastic resin (A), the content of fatty acid ester (B) is 10 to 90 parts by mass, preferably 20 to 80 parts by mass, and more preferably 30 to 75 parts by mass. By having the fatty acid ester (B) content within the above range, when the molded article is formed, the fatty acid ester (B) does not leak out of the resin (bleed out), a sufficient phase transition effect can be obtained, and a molded article with excellent brittleness resistance and lightweight properties can be obtained.

[0068] If the composition contains a porous inorganic compound (C), its content is preferably more than 0 parts by mass and less than 1.5 parts by mass, more preferably 0.05 to 1.4 parts by mass, and even more preferably 0.1 to 1.2 parts by mass, per 100 parts by mass of thermoplastic resin (A). By having the content of the porous inorganic compound (C) within the above range, the stickiness of the resulting pellets can be suppressed.

[0069] <Optional Components> In addition to components (A) to (C) described above, this composition may contain additives such as slip agents, nucleating agents, fillers, antioxidants, weather stabilizers, colorants (including thermochromic materials), foaming agents, pigments, dyes, antistatic agents, and flame retardants, to the extent that they do not impair the effects of the present invention.

[0070] <Method for Producing the Composition> The method for producing the composition comprises the step of kneading a thermoplastic resin (A), a fatty acid ester (B), and optionally a porous inorganic compound (C) and other optional components at a temperature of 150°C or higher, preferably 152°C to 300°C, and more preferably 154°C to 260°C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes.

[0071] Mixing equipment can include mixing rolls, intensive mixers (e.g., Banbury mixers, kneaders), and single-screw or twin-screw extruders, but closed-type equipment is preferred.

[0072] [Molded Article] The molded article of the present invention consists of the composition described above. Various known methods can be used as the molding method. Specifically, these include extrusion molding, press molding, injection molding, calendering, and hollow molding. Furthermore, the molded article obtained by the molding method, such as a sheet, can be subjected to secondary processing by thermoforming or laminated with other materials to form a molded article. In addition, it can be formed into a granular molded article such as a bead or a cylindrical molded article.

[0073] The applications of the molded articles of the present invention are not particularly limited, but are suitable for a variety of known applications, such as automotive parts, civil engineering and construction materials, electrical and electronic components, household goods, hygiene products, films and sheets, and foams. In particular, they are useful as materials for steering wheels and instrument panels that become hot inside cars in the summer, as well as for interior wall materials, bathtub materials, wearable materials, apparel materials, shoes, various cooling materials, cooling containers, heat-insulating materials, filling materials for cooling neck pillows, filling materials for pillows, and heat-insulating containers.

[0074] The present invention will be described in more detail below based on examples, but the present invention is not limited in any way to these examples.

[0075] [Melting Point and Heat of Melting] The melting point and heat of fusion ΔHm of the resins used in the examples and comparative examples were measured using a differential scanning calorimeter ("DSC700X" manufactured by Hitachi High-Tech Science Corporation) as follows: Approximately 5 mg of resin was sealed in a measuring aluminum pan and heated from room temperature to 230°C at a rate of 10°C / min. It was held at 230°C for 5 minutes to completely melt the resin, and then cooled to -70°C at a rate of 10°C / min. After holding at -70°C for 5 minutes, it was heated a second time to 230°C at a rate of 10°C / min. The peak of the melting point during the second heating was taken as the melting point, and the amount of heat at that time (heat of fusion ΔHm) was measured.

[0076] [Materials] The components of the resin compositions produced in the examples and comparative examples are as follows: <Thermoplastic resin> ・A1-1: "EV260" manufactured by Mitsui Dow Polychemical Co., Ltd. (ethylene vinyl acetate copolymer, MFR (compliant with JIS K7210:1999, 190℃, 2.16 kg load): 6 g / 10 min, VA content: 28 mass%, melting point: 71℃, heat of fusion ΔHm: 47 J / g, value derived from intermolecular dispersion force of Hansen distance parameter: 18.5) ・A2-1: "vistamax 6102" manufactured by Exxonmobil (propylene ethylene copolymer, MFR (JIS K7210:1999) A2-2: Ethylene-butene copolymer, MFR (JIS K7210:1999 compliant, 190°C, 2.16 kg load): 1.4 g / 10 min, ethylene content: 16 mass%, melting point: 104°C, heat of fusion ΔHm: 3.0 J / g, value derived from intermolecular dispersion force of Hansen distance parameter: 16.9) ・A2-2: Ethylene-butene copolymer, MFR (JIS K7210:1999 compliant, 190°C, 2.16 kg load): 1.4 g / 10 min, ethylene content: 83 mass%, melting point: 51°C, heat of fusion ΔHm: 35 J / g, value derived from intermolecular dispersion force of Hansen distance parameter: 17.5) ・A2-3: Ethylene-propylene copolymer, MFR (JIS A3-1: Prime Polymer Co., Ltd. "F327" (propylene polymer, MFR (JIS K7210:1999 compliant, 190°C, 2.16 kg load): 1.4 g / 10 min, ethylene content: 65 mass%, melting point: 33°C, heat of fusion ΔHm: 22 J / g, value derived from intermolecular dispersion force of Hansen distance parameter: 17.2) ・A3-1: Prime Polymer Co., Ltd. "F327" (propylene polymer, MFR (JIS K7210:1999 compliant, 190°C, 2.16 kg load): 4 g / 10 min, melting point: 138°C, heat of fusion ΔHm: 76 J / g, value derived from intermolecular dispersion force of Hansen distance parameter: 16.8) ・A4-1: Modified isotactic homopolypropylene (MFR (ASTM Compliant with D1238, 230°C, 2.16 kg load): 100 g / 10 min, density: 0.90 g / cm³ ３ (Amount of maleic anhydride graft: 3.0% by mass, value of Hansen distance parameter derived from intermolecular dispersion forces: 16.8)

[0077] <Fatty Acid Esters> ・B1-1: "TOENOL #2018-65" manufactured by Toei Chemical Co., Ltd. (Methyl stearate, melting point: 30°C, heat of fusion ΔHm: 206 J / g) ・B2-1: "Unistar M-9676" manufactured by NOF Corporation (Stearyl stearate, melting point: 54°C, heat of fusion ΔHm: 234 J / g) ・B2-2: "Excepearl MY-M" manufactured by Kao Corporation (Myristyl myristate, melting point: 45°C, heat of fusion ΔHm: 229 J / g) ・B2-3: "Sperm Acetate" manufactured by NOF Corporation (Cetyl myristate, melting point: 50°C, heat of fusion ΔHm: 241 J / g)

[0078] [Examples 1-14 and Comparative Examples 1-10] Thermoplastic resin and fatty acid ester in the amounts (parts by mass) shown in Tables 1 and 2 were kneaded for 5 minutes at a temperature of 150°C and a torque rotation speed of 30 rpm using a Laboplast Mill (Toyo Seiki Seisakusho Co., Ltd. "80C100"). After kneading, the kneaded material (composition) was quickly collected. The obtained composition was finely cut with scissors to a size of approximately 0.5 cm × 0.5 cm × 0.5 cm. The heat retention properties of the obtained composition were evaluated as described later. The results are shown in Tables 1 and 2.

[0079] Next, the obtained cut material was hot-pressed at a pressure of 10 MPa for 5 minutes using a compression molding machine (NSF-37, manufactured by Shinto Metal Industries Co., Ltd.) set to 150°C. The material was then quickly transferred to another compression molding machine (NSF-37, manufactured by Shinto Metal Industries Co., Ltd.) set to 20°C and cooled at a pressure of 10 MPa for 5 minutes to obtain a 4.5 cm square, 1 mm thick press sheet sample. The prepared press sheet sample was then subjected to a bleed-out evaluation, as described later. The results are shown in Tables 1 and 2.

[0080] <Heat Retention Evaluation> Measurements were performed using a differential scanning calorimeter (DSC700X, manufactured by Hitachi High-Tech Science Co., Ltd.) following the procedure below. First, approximately 5 mg of the obtained composition was sealed in an aluminum pan for measurement and cooled from room temperature to -50°C at a rate of 3°C / min, and held at -50°C for 5 minutes. Then, it was heated to 150°C at a rate of 3°C / min. From the melting peak obtained during the measurement, information on the enthalpy of melting ΔH (J / g) was obtained. Based on the obtained value of ΔH, the following criteria were used for evaluation: ○: Greater than 50 J / g △: 25 to 50 J / g ×: Less than 25 J / g

[0081] <Bleed-out> The press sheet samples obtained above were sandwiched between 5 cm square pieces of absorbent paper and heated at the melting point of the fatty acid ester + 10°C for 24 hours. Samples with ester adhesion to the absorbent paper were rated "0", while samples with no adhesion were left to stand at 23°C for one week, and the bleed-out was evaluated on a scale of 1 to 5. A higher number indicates less bleed-out. 1: Ester bleed-out is visible across the entire surface of the sample (ester is white). 2: Ester bleed-out is visible on 3 / 4 of the sample surface. 3: Ester bleed-out is visible on 1 / 2 of the sample surface. 4: No ester bleed-out is visible on the sample surface, but it feels slippery to the touch. 5: No ester bleed-out is visible on the sample surface, and it does not feel slippery to the touch.

[0082]

[0083]

Claims

1. A resin composition comprising 100 parts by mass of a thermoplastic resin (A) and 10 to 90 parts by mass of a fatty acid ester (B), wherein the thermoplastic resin (A) comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer (A1) and olefin-based elastomer (A2), and the melting point of the main component of the thermoplastic resin (A) is 55°C or higher.

2. The resin composition according to claim 1, wherein the thermoplastic resin (A) comprises the ethylene vinyl acetate copolymer (A1), and the fatty acid ester (B) comprises a fatty acid ester (B1) having a heat of fusion (ΔHm) of 225 J / g or less.

3. The resin composition according to claim 2, wherein the fatty acid ester (B1) comprises methyl stearate.

4. The resin composition according to claim 1, wherein the thermoplastic resin (A) further comprises 2 to 30% by mass of a propylene polymer (A3) (with the total thermoplastic resin (A) being 100% by mass).

5. The resin composition according to claim 1, wherein the thermoplastic resin (A) further comprises 1 to 10% by mass of a modified propylene polymer (A4) (the total amount of the thermoplastic resin (A) is 100% by mass).

6. The resin composition according to claim 5, wherein the melt flow rate of the modified propylene polymer (A4) (according to ASTM D1238, 230°C, 2.16 kg load) is 25 g / 10 min or more.

7. The resin composition according to claim 5, wherein the modified propylene polymer (A4) comprises a modified product obtained by modifying an unsaturated carboxylic acid or a derivative thereof, and the degree of modification is 0.1% by mass to 5.0% by mass.

8. The resin composition according to claim 1, wherein the thermoplastic resin (A) comprises the olefin-based elastomer (A2), and the fatty acid ester (B) comprises a fatty acid ester (B2) having a heat of fusion (ΔHm) of more than 225 J / g.

9. The resin composition according to claim 8, wherein the fatty acid ester (B2) comprises at least one selected from the group consisting of stearyl stearate, myristyl myristate, and cetyl myristate.

10. The resin composition according to claim 1, wherein the value of the Hansen distance parameter in the olefin-based elastomer (A2) that is derived from the intermolecular dispersion force is less than 17.

2.

11. The resin composition according to claim 1, further comprising a porous inorganic compound (C) in an amount greater than 0 parts by mass and less than 1.5 parts by mass.

12. A molded article comprising the resin composition according to any one of claims 1 to 11.

13. Building materials comprising the resin composition according to any one of claims 1 to 11.

14. A pillow filler comprising the resin composition described in any one of claims 1 to 11.

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