Resin composition, compact, wire covering material, solar battery sealant, solar battery laminate sheet, foam molding body and footwear

Abstract

To provide a resin composition that, while having performance balance between basic physical property and resin compound physical property of same level with a resin composition produced using only a resin obtained from conventional fossil fuel, has improved environmental consideration.SOLUTION: A resin composition that contains (A) a carbohydrate polymer containing starch and a plasticizer and (B) an ethylene / unsaturated ester copolymer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a molded article, an electric wire covering material, a solar cell encapsulant, a laminated sheet for solar cells, a foam molded article, and footwear. [Background technology]

[0002] Ethylene-unsaturated ester copolymers such as ethylene-vinyl acetate copolymers and ethylene-ethyl acrylate copolymers are used in a variety of applications due to their excellent transparency, flexibility, weather resistance, impact resistance, low-temperature properties, filler loading, etc. Patent documents relating to resins containing such ethylene-unsaturated ester copolymers include Patent Documents 1 to 3.

[0003] Patent Document 1 describes an adhesive resin composition comprising: (A) 39 to 84.9% by weight of an ethylene-vinyl acetate copolymer consisting of 93 to 97% by weight of ethylene residue units and 3 to 7% by weight of vinyl acetate residue units and having a melt mass-flow rate of 8 to 30 g / 10 min as measured according to JIS K6924-1; (B) 5 to 20% by weight of an ethylene-vinyl acetate copolymer consisting of 80 to 90% by weight of ethylene residue units and 10 to 20% by weight of vinyl acetate residue units; (C) 5 to 20% by weight of low-density polyethylene; (D) 5 to 20% by weight of a tackifier resin; and (E) 0.1 to 1% by weight of an antistatic agent (E). The adhesive resin composition is described as having excellent short-time heat sealing properties, heat sealing strength stability, and heat sealing time dependency, and further, an easily peelable film obtained by forming an adhesive layer made of this adhesive resin composition on a support, when adhered to, for example, a paper container, does not cause fuzzing on the paper container upon peeling, and also has excellent properties of maintaining the initial peelability even when stored in a high-temperature environment after adhesion.

[0004] Patent Document 2 describes a cover tape for electronic component carriers, which has an adhesive layer that is heat-sealed to a plastic carrier tape having pockets for storing electronic components, and which is characterized in that the adhesive layer is formed from a composition whose main components are an ethylene-α-olefin copolymer or at least one of the α-olefin copolymers and an ethylene-vinyl acetate copolymer. It describes that this cover tape for electronic component carriers can be heat-sealed to the plastic carrier tape with sufficient adhesive strength and can be peeled off smoothly, regardless of whether the plastic carrier tape has been subjected to a release treatment or whether an antistatic agent or conductive particles have been added to the adhesive, thereby enabling electronic components to be transported safely and then picked up without jumping travel during the mounting process.

[0005] Patent Document 3 describes a heat-meltable composition containing an ethylene-vinyl acetate copolymer (A), an olefin-based polymer (B), a wax (C), and a tackifier resin (D), the heat-meltable composition containing 2 to 25 mass% of an ethylene-vinyl acetate copolymer (A) having an MFR of 100 to 2700 (g / 10 min) measured at a load of 21.18 N and 190°C, 10 to 40 mass% of an olefin-based polymer (B) having an MFR of 0.5 to 60 (g / 10 min) measured at a load of 21.18 N and 190°C, 35 to 65 mass% of a wax (C) having a melting point of 40 to 65°C, and 3 to 25 mass% of a tackifier resin (D) having a softening point of 100 to 160°C. The document states that the hot-melt composition has been able to provide a hot-melt composition that has appropriate sealing performance and opening strength for sealing a food container filled with contents, can be easily peeled off when the container is opened, does not allow the contents to adhere when the container is opened, does not leave any of the hot-melt composition on the flange of the container when the container is opened, and has impact resistance that prevents the contents from scattering when the container is transported or dropped. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-25047 [Patent Document 2] Japanese Patent Application Publication No. 10-17015 [Patent Document 3] Japanese Patent Application Publication No. 2018-150444 Summary of the Invention [Problem to be solved by the invention]

[0007] Resins containing ethylene-unsaturated ester copolymers are generally derived from fossil fuels, but petroleum, a fossil fuel, is in danger of becoming depleted and emits large amounts of carbon dioxide during the manufacturing process and disposal of the product, raising concerns about its impact on global warming.

[0008] The present invention has been made in consideration of the above circumstances, and provides a resin composition that has improved environmental friendliness while maintaining a performance balance of basic physical properties and resin compound physical properties equivalent to those of resin compositions produced using only conventional resins obtained from fossil fuels. [Means for solving the problem]

[0009] The present inventors have found that by using a resin composition containing a carbohydrate-based polymer (A) containing starch and a plasticizer, and an ethylene-unsaturated ester copolymer (B), it is possible to obtain a resin composition that has improved environmental friendliness while maintaining a performance balance of basic physical properties and resin compound physical properties equivalent to those of resin compositions produced using only conventional raw materials derived from fossil fuels.

[0010] The present invention provides the following resin composition, molded article, electric wire covering material, solar cell encapsulant, laminated sheet for solar cells, foam molded article, and footwear.

[0011] [1] A resin composition comprising a carbohydrate-based polymer (A) containing starch and a plasticizer, and an ethylene-unsaturated ester copolymer (B). [2] The resin composition according to [1] above, wherein the plasticizer contains glycerin. [3] The resin composition according to [1] or [2], wherein the content of the carbohydrate-based polymer (A) in the resin composition is 1% by mass or more and 99% by mass or less, when the total resin components of the resin composition are taken as 100% by mass. [4] The resin composition according to any one of the above [1] to [3], wherein the ethylene-unsaturated ester copolymer (B) comprises an ethylene-vinyl acetate copolymer. [5] The resin composition according to any one of the above [1] to [4], wherein the content of structural units derived from unsaturated ester in the ethylene-unsaturated ester copolymer (B) is 4% by mass or more and 46% by mass or less, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass. [6] The resin composition according to any one of the above [1] to [5], wherein the ethylene-unsaturated ester copolymer (B) contains a petroleum-derived raw material. [7] The resin composition according to any one of [1] to [6] above, wherein the content of the ethylene-unsaturated ester copolymer (B) in the resin composition is 1% by mass or more and 99% by mass or less, when the total resin components of the resin composition are taken as 100% by mass. [8] The resin composition according to any one of the above [1] to [7], wherein the melt mass flow rate (MFR) measured in accordance with JIS K 7210:1999 at 190°C under a load of 2160 g is 0.1 g / 10 min or more and 50 g / 10 min or less. [9] A molded article obtained by molding the resin composition according to any one of the above [1] to [8].

[10] A wire covering material comprising the resin composition according to any one of the above [1] to [8] or the molded article according to the above [9].

[11] A solar cell encapsulant comprising the resin composition according to any one of the above [1] to [8] or the molded article according to the above [9].

[12] A laminated sheet for solar cells, comprising the resin composition according to any one of the above [1] to [8].

[13] A foamed molded article obtained by heating and foaming the resin composition according to any one of the above [1] to [8].

[14] Footwear comprising the foamed molded article described in

[13] above. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a resin composition that has improved environmental friendliness while maintaining a performance balance of basic physical properties and resin compound physical properties equivalent to those of conventional resin compositions produced using only fossil fuel-derived resins. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification, "A to B" indicating a range of values means A or more and B or less unless otherwise specified.

[0014] 1.Resin composition The resin composition of this embodiment contains a carbohydrate-based polymer (A) containing starch and a plasticizer, and an ethylene-unsaturated ester copolymer (B).

[0015] According to the resin composition of this embodiment, by using a resin composition containing a carbohydrate-based polymer (A) containing starch and a plasticizer, and an ethylene-unsaturated ester copolymer (B), it is possible to provide a resin composition that has improved environmental friendliness while maintaining a performance balance of basic physical properties and resin compound physical properties equivalent to those of resin compositions produced using only conventional raw materials derived from fossil fuels.

[0016] <Carbohydrate-based polymer (A)> The carbohydrate-based polymer (A) of this embodiment contains starch and a plasticizer, which improves the environmental friendliness of the resin composition of this embodiment.

[0017] From the viewpoint of environmental friendliness, the starch of this embodiment preferably includes one or more types selected from the group consisting of raw starch and modified starch.

[0018] The raw starch of this embodiment preferably includes starch obtained from one or more species selected from the group consisting of corn, potato, tapioca, sweet potato, wheat, cassava, sago, sorghum, rice, beans, arrowroot, bracken, lotus, and water chestnut.

[0019] The processed starch of this embodiment preferably includes starches obtained from one or more species selected from the group consisting of physically modified starches (e.g., pregelatinized starch, fractionated amylose, moist heat-treated starch, etc.), enzyme-modified starches (e.g., hydrolyzed dextrin, enzymatically decomposed dextrin, amylose, etc.), chemically decomposed modified starches (e.g., acid-treated starch, hypochlorite-oxidized starch, dialdehyde starch, etc.), and chemically modified starch derivatives (e.g., esterified starch, etherified starch, cationized starch, cross-linked starch, etc.).

[0020] The esterified starch of this embodiment preferably includes one or more starches selected from the group consisting of acetate-esterified starch, succinate-esterified starch, nitrate-esterified starch, phosphate-esterified starch, urea-phosphate-esterified starch, xanthate-esterified starch, and acetoacetate-esterified starch.

[0021] The etherified starch of this embodiment preferably includes one or more starches selected from the group consisting of allyl etherified starch, methyl etherified starch, carboxymethyl etherified starch, hydroxyethyl etherified starch, and hydroxypropyl etherified starch.

[0022] The crosslinked starch of this embodiment preferably includes one or more starches selected from the group consisting of formaldehyde-crosslinked starch, epichlorohydrin-crosslinked starch, phosphate-crosslinked starch, and acrolein-crosslinked starch.

[0023] The pregelatinized starch of this embodiment is a starch in which raw starch having a crystalline structure (β structure) is subjected to a temperature environment of approximately 70°C or higher in the presence of an appropriate amount of moisture, resulting in the breakdown of the β structure and conversion to an amorphous structure (α structure). This process of raw starch being heated in the presence of moisture and then converted from a β structure to an α structure is called "gelatinization." Compared to the β structure, α structure starch is preferred because it has significantly better dispersibility in thermoplastic resins. When pregelatinized starch is left at low temperatures while still containing moisture, it may revert to its original β structure, a crystalline state (known as "retrogradation"). It is known that the α structure can be maintained by quickly removing moisture from the amorphous state of pregelatinized starch. Specifically, dehydrated α structure starch can be obtained by heating the starch in the presence of moisture to gelatinize it, and then reducing the pressure in a vacuum device.

[0024] From the viewpoint of the performance balance of basic physical properties, resin compound physical properties, and environmental friendliness, the content of starch in the carbohydrate-based polymer (A) of this embodiment is preferably 10% by mass or more and 99% by mass or less, more preferably 20% by mass or more and 97% by mass or less, even more preferably 30% by mass or more and 95% by mass or less, even more preferably 40% by mass or more and 93% by mass or less, even more preferably 50% by mass or more and 90% by mass or less, even more preferably 60% by mass or more and 85% by mass or less, and even more preferably 70% by mass or more and 80% by mass or less, when the entire carbohydrate-based polymer (A) is taken as 100% by mass.

[0025] From the viewpoint of the balance of basic physical properties and resin compound physical properties, the plasticizer of the present embodiment preferably contains one or more plasticizers selected from the group consisting of glycerin and glycerin fatty acid esters, and more preferably contains glycerin from the viewpoint of environmental friendliness.

[0026] The glycerin fatty acid ester of the present embodiment may be any of a monoester, a diester, and a triester, and preferably includes one or more selected from the group consisting of acetate monoglyceride, lactate monoglyceride, citrate monoglyceride, diacetyltartaric acid monoglyceride, glycerin diacetomonolaurate, succinate monoglyceride, polyglycerin condensed linosyl acid ester, and glycerin diacetomonolaurate.

[0027] From the viewpoint of the performance balance between basic physical properties, resin compound physical properties, and environmental friendliness, the content of the plasticizer in the carbohydrate-based polymer (A) of this embodiment is preferably 1% by mass or more and 90% by mass or less, more preferably 3% by mass or more and 80% by mass or less, even more preferably 5% by mass or more and 70% by mass or less, even more preferably 7% by mass or more and 60% by mass or less, even more preferably 10% by mass or more and 50% by mass or less, even more preferably 15% by mass or more and 40% by mass or less, and even more preferably 20% by mass or more and 30% by mass or less, when the entire carbohydrate-based polymer (A) is taken as 100% by mass.

[0028] From the viewpoint of the balance of basic physical properties, resin compound physical properties, and environmental friendliness, the content of the carbohydrate polymer (A) in the resin composition of this embodiment, when the entire resin component of the resin composition is taken as 100 mass%, is preferably 1 mass% or more and 99 mass% or less, more preferably 1 mass% or more and 75 mass% or less, even more preferably 3 mass% or more and 70 mass% or less, even more preferably 3 mass% or more and 60 mass% or less, even more preferably 3 mass% or more and 50 mass% or less, even more preferably 3 mass% or more and 40 mass% or less, even more preferably 5 mass% or more and 30 mass% or less, even more preferably 5 mass% or more and 25 mass% or less, even more preferably 7 mass% or more and 25 mass% or less, even more preferably 9 mass% or more and 23 mass% or less, and even more preferably 10 mass% or more and 20 mass% or less.

[0029] From the viewpoint of improving environmental friendliness, the biomass degree of the carbohydrate-based polymer (A) of this embodiment, measured in accordance with ASTM D6866, is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 99% by mass or more. There is no upper limit to the biomass degree, but it is, for example, 100% by mass or less.

[0030] <Ethylene-unsaturated ester copolymer (B)> The ethylene-unsaturated ester copolymer (B) of this embodiment is a copolymer of ethylene and at least one unsaturated ester. The ethylene-unsaturated ester copolymer (B) of the present embodiment may be in the form of a block copolymer, a random copolymer, or a graft copolymer. From the viewpoint of productivity, however, it preferably includes a binary random copolymer, a tertiary random copolymer, a graft copolymer of a binary random copolymer, or a graft copolymer of a tertiary random copolymer, and more preferably includes a binary random copolymer or a tertiary random copolymer. Furthermore, from the viewpoint of further improving basic physical properties such as mechanical strength and processability, the ethylene-unsaturated ester copolymer (B) preferably contains one or two selected from an ethylene-vinyl ester copolymer and an ethylene-unsaturated carboxylic acid ester copolymer, and more preferably contains an ethylene-vinyl ester copolymer. The ethylene-unsaturated ester copolymer (B) may contain a polymerizable monomer other than ethylene and unsaturated ester, for example, an α-olefin such as propylene, butene, or hexene.

[0031] The ethylene-vinyl ester copolymer of the present embodiment preferably contains one or more copolymers selected from ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, and ethylene-vinyl stearate copolymer, from the viewpoint of further improving basic physical properties such as mechanical strength and processability, and more preferably contains ethylene-vinyl acetate copolymer, from the viewpoint of further improving basic physical properties such as mechanical strength and processability.

[0032] The ethylene-unsaturated carboxylic acid ester copolymer of this embodiment is a copolymer of ethylene and at least one unsaturated carboxylic acid ester. Specifically, it can be a copolymer made of ethylene and an unsaturated carboxylic acid alkyl ester.

[0033] From the viewpoint of further improving basic physical properties such as mechanical strength and processability, the unsaturated carboxylic acid in the unsaturated carboxylic acid ester of the present embodiment preferably includes one or more unsaturated carboxylic acids selected from the group consisting of acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate, and monoethyl maleate. Among these, the unsaturated carboxylic acid preferably includes one or more selected from the group consisting of acrylic acid and methacrylic acid, from the viewpoint of further improving the productivity and sanitation of the ethylene-unsaturated ester copolymer (B).

[0034] From the viewpoint of further improving basic physical properties such as mechanical strength and processability, the alkyl moiety in the unsaturated carboxylic acid alkyl ester of this embodiment preferably contains an alkyl group having 1 to 12 carbon atoms, and more preferably contains one or more alkyl groups selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, 2-ethylhexyl, and isooctyl groups. Among these, from the viewpoint of further improving basic physical properties such as mechanical strength and processability, the alkyl moiety preferably contains one or more alkyl groups selected from the group consisting of methyl and ethyl groups, and more preferably contains a methyl group.

[0035] The unsaturated carboxylic acid ester of this embodiment preferably contains a (meth)acrylic acid alkyl ester from the viewpoint of further improving basic physical properties such as mechanical strength and processability. From the viewpoint of further improving basic physical properties such as mechanical strength and processability, the (meth)acrylic acid alkyl ester of this embodiment preferably contains one or more selected from methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dimethyl maleate, and diethyl maleate, more preferably one or two or more selected from methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, isobutyl (meth)acrylate, and n-butyl (meth)acrylate, even more preferably one or two or more selected from methyl (meth)acrylate and ethyl (meth)acrylate, and even more preferably methyl (meth)acrylate.

[0036] From the viewpoint of further improving basic physical properties such as mechanical strength, processability, and productivity, the content of structural units derived from ethylene in the ethylene-unsaturated ester copolymer (B) of the present embodiment is preferably from 54 to 96% by mass, more preferably from 57 to 93% by mass, even more preferably from 60 to 90% by mass, even more preferably from 63 to 88% by mass, and even more preferably from 66 to 85% by mass, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass.

[0037] The content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (B) of the present embodiment, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass, is preferably 4% by mass or more, more preferably 7% by mass or more, even more preferably 10% by mass or more, even more preferably 12% by mass or more, and still more preferably 15% by mass or more, from the viewpoint of further improving basic physical properties such as processability and mechanical strength; and is preferably 46% by mass or less, more preferably 43% by mass or less, even more preferably 40% by mass or less, even more preferably 37% by mass or less, and still more preferably 34% by mass or less, from the viewpoint of further improving basic physical properties such as processability and mechanical strength. That is, the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (B) of the present embodiment, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass, is preferably from 4 to 46% by mass, more preferably from 7 to 43% by mass, even more preferably from 10 to 40% by mass, even more preferably from 12 to 37% by mass, and still more preferably from 15 to 34% by mass, from the viewpoint of further improving basic physical properties such as flexibility, mechanical strength, and processability.

[0038] When the ethylene-unsaturated ester copolymer (B) is an ethylene-vinyl acetate copolymer, the content of constituent units derived from vinyl acetate can be determined in accordance with JIS K7192:1999 by heating the ethylene-vinyl acetate copolymer in an electric furnace to 500°C or higher to decompose it, and then subjecting the resulting acetic acid derived from vinyl acetate to neutralization titration.

[0039] Furthermore, from the viewpoint of further improving basic physical properties such as mechanical strength, processability, and productivity, the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (B) of this embodiment is, when the entire resin component of the resin composition of this embodiment is taken as 100 mass%, preferably 1 mass% or more, more preferably 3 mass% or more, even more preferably 5 mass% or more, even more preferably 8 mass% or more, even more preferably 10 mass% or more, and even more preferably 12 mass% or more; and from the viewpoint of further improving basic physical properties such as processability and mechanical strength, it is preferably 50 mass% or less, more preferably 45 mass% or less, even more preferably 40 mass% or less, even more preferably 35 mass% or less, and even more preferably 30 mass% or less. That is, from the viewpoint of further improving basic physical properties such as mechanical strength, processability, and productivity, the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (B) of this embodiment is preferably from 1 to 50% by mass, more preferably from 3 to 50% by mass, even more preferably from 5 to 45% by mass, even more preferably from 8 to 40% by mass, even more preferably from 10 to 35% by mass, and even more preferably from 12 to 30% by mass, when the entire resin components of the resin composition of this embodiment are taken as 100% by mass.

[0040] In the resin composition of this embodiment, the content of structural units derived from unsaturated esters when the entire resin components of the resin composition are taken as 100% by mass is calculated by multiplying the content (% by mass) of structural units derived from unsaturated esters when the ethylene-unsaturated ester copolymer (B) is taken as 100% by mass by the content (% by mass) of ethylene-unsaturated ester copolymer (B) when the entire resin components of the resin composition are taken as 100% by mass, and dividing the product by 100.

[0041] From the viewpoint of a balance of basic physical properties, resin compound physical properties, and environmental friendliness, the content of the ethylene-unsaturated ester copolymer (B) in the resin composition of this embodiment, when the total resin components of the resin composition is taken as 100 mass%, is preferably from 1 to 99 mass%, more preferably from 25 to 99 mass%, even more preferably from 30 to 97 mass%, even more preferably from 40 to 97 mass%, even more preferably from 50 to 97 mass%, even more preferably from 60 to 97 mass%, even more preferably from 70 to 95 mass%, even more preferably from 75 to 95 mass%, even more preferably from 75 to 93 mass%, even more preferably from 77 to 91 mass%, and even more preferably from 80 to 90 mass%.

[0042] From the viewpoint of further improving the physical properties of the resin compound, the melt mass flow rate (MFR) of the ethylene-unsaturated ester copolymer (B) of the present embodiment, measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g, is preferably 0.01 g / 10 min or more and 300 g / 10 min or less, more preferably 0.01 g / 10 min or more and 250 g / 10 min or less, even more preferably 0.1 g / 10 min or more and 200 g / 10 min or less, even more preferably 0.1 g / 10 min or more and 150 g / 10 min or less, even more preferably 1.0 g / 10 min or more and 100 g / 10 min or less, even more preferably 1.0 g / 10 min or more and 50 g / 10 min or less, and even more preferably 2.0 g / 10 min or more and 30 g / 10 min or less.

[0043] The ethylene-unsaturated ester copolymer (B) of this embodiment preferably contains a petroleum-derived raw material from the viewpoint of further improving basic physical properties such as mechanical strength, processability, and productivity.

[0044] From the viewpoint of further improving basic physical properties such as mechanical strength, processability, and productivity, the content of petroleum-derived raw materials in the ethylene-unsaturated ester copolymer (B) of the present embodiment is preferably 50% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, even more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, and even more preferably 90% by mass or more and 100% by mass or less, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass.

[0045] The method for producing the ethylene-unsaturated ester copolymer (B) of this embodiment is not particularly limited, and it can be produced by a known method. For example, it can be obtained by radical copolymerization of the polymerization components under high temperature and high pressure. Furthermore, commercially available ethylene-unsaturated ester copolymers (B) of this embodiment may be used.

[0046] <Other ingredients> The resin composition of this embodiment may contain various additives within the scope of the present invention, such as one or more additives selected from the group consisting of inorganic fillers such as silica and talc, antioxidants, weather stabilizers, wavelength conversion agents, antistatic agents, antifogging agents, antiblocking agents, slip agents, and pigments. Furthermore, the resin composition according to this embodiment may also contain resins other than the carbohydrate polymer (A) and the ethylene-unsaturated ester copolymer (B) within the scope of the present invention.

[0047] The resin composition of this embodiment can be prepared by, for example, simultaneously or continuously mixing the carbohydrate polymer (A), the ethylene-unsaturated ester copolymer (B), and any additives, and the mixing order is not limited. As a preparation method, melt mixing using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, various kneaders, etc. is preferred. If necessary, it can be made into pellets.

[0048] <Physical properties of resin composition> The melt mass flow rate (MFR) of the resin composition of the present embodiment, measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g, is preferably 0.1 g / 10 min or more and 50 g / 10 min or less, more preferably 0.1 g / 10 min or more and 45 g / 10 min or less, even more preferably 0.5 g / 10 min or more and 40 g / 10 min or less, even more preferably 0.5 g / 10 min or more and 35 g / 10 min or less, even more preferably 1.0 g / 10 min or more and 30 g / 10 min or less, even more preferably 1.0 g / 10 min or more and 25 g / 10 min or less, and even more preferably 1.2 g / 10 min or more and 20 g / 10 min or less, from the viewpoint of further improving basic physical properties such as moldability and processability.

[0049] The density of the resin composition of this embodiment, measured in accordance with JIS K 7112:1999, is preferably 910 kg / m from the viewpoint of further improving basic physical properties such as mechanical strength. 3 More preferably, 920 kg / m 3 More preferably, 930 kg / m 3 More preferably, 940 kg / m 3 More preferably, 950 kg / m 3 More preferably, 960 kg / m 3 From the viewpoint of further improving the balance of basic physical properties such as mechanical strength and processability, it is preferable that the 3 or less, more preferably 1150 kg / m 3 or less, more preferably 1100 kg / m 3 or less, more preferably 1050 kg / m 3 The following is the result. That is, the density of the resin composition of the present embodiment, as measured in accordance with JIS K 7112:1999, is preferably 910 kg / m from the viewpoint of further improving the balance of basic physical properties such as mechanical strength and processability. 3 More than 1200kg / m 3 Less than or equal to 920 kg / m 3 More than 1200kg / m 3 or less, more preferably 930 kg / m 3More than 1150kg / m 3 or less, more preferably 940 kg / m 3 More than 1150kg / m 3 or less, more preferably 950 kg / m 3 More than 1100kg / m 3 or less, more preferably 960 kg / m 3 More than 1050kg / m 3 The following is the result.

[0050] The stress at break of the resin composition of the present embodiment, measured in accordance with JIS K 7161-1:2014, is preferably 5 MPa or more, more preferably 8 MPa or more, even more preferably 10 MPa or more, and even more preferably 12 MPa or more, from the viewpoint of further improving basic physical properties such as mechanical strength. In the resin composition of the present embodiment, there is no upper limit to the stress at break measured in accordance with JIS K 7161-1:2014, but it may be, for example, 50 MPa or less, 45 MPa or less, 40 MPa or less, 35 MPa or less, 30 MPa or less, or 25 MPa or less. That is, from the viewpoint of further improving basic physical properties such as mechanical strength, the stress at break of the resin composition of this embodiment, measured in accordance with JIS K 7161-1:2014, is preferably 5 MPa or more and 50 MPa or less, more preferably 8 MPa or more and 50 MPa or less, even more preferably 10 MPa or more and 50 MPa or less, even more preferably 12 MPa or more and 50 MPa or less, even more preferably 12 MPa or more and 45 MPa or less, even more preferably 12 MPa or more and 40 MPa or less, even more preferably 12 MPa or more and 35 MPa or less, even more preferably 12 MPa or more and 30 MPa or less, and even more preferably 12 MPa or more and 25 MPa or less.

[0051] The elongation at break of the resin composition of this embodiment, measured in accordance with JIS K 7161-2:2014, is preferably 450% or more, more preferably 500% or more, even more preferably 550% or more, even more preferably 600% or more, and even more preferably 650% or more, from the viewpoint of further improving basic physical properties such as flexibility, and is preferably 1000% or less, more preferably 950% or less, even more preferably 900% or less, and even more preferably 850% or less, from the viewpoint of further improving basic physical properties such as mechanical strength and heat resistance. That is, from the viewpoint of further improving basic physical properties such as flexibility, mechanical strength, and heat resistance, the elongation at break of the resin composition of this embodiment, measured in accordance with JIS K 7161-2:2014, is preferably 450% or more and 1000% or less, more preferably 500% or more and 1000% or less, even more preferably 550% or more and 950% or less, even more preferably 600% or more and 900% or less, and even more preferably 650% or more and 850% or less.

[0052] The stress at break (based on JIS K 7161-1:2014) and elongation at break (based on JIS K 7161-2:2014) of the resin composition according to this embodiment are measured using a tensile tester. A press sheet of the resin composition according to this embodiment is cut into a dumbbell-shaped test piece according to the JIS standard, and the test piece is pulled under the conditions of a chuck distance of 90 mm, a pulling speed of 50 mm / min, 23°C, and a relative humidity of 50%RH. The elongation at break represents the elongation of the test piece just before break between the designated gauge points in the tensile test. The stress at break is the value obtained by dividing the tensile force at the break point in the tensile test by the initial cross-sectional area of the test piece.

[0053] The Shore A hardness of the resin composition of the present embodiment, measured in accordance with JIS K 7215:1986, is preferably 50 or more, more preferably 55 or more, even more preferably 60 or more, even more preferably 65 or more, and even more preferably 70 or more, from the viewpoint of further improving basic physical properties such as moldability and heat resistance, and is preferably 120 or less, more preferably 110 or less, and even more preferably 100 or less, from the viewpoint of further improving basic physical properties such as moldability and flexibility. That is, from the viewpoint of further improving basic physical properties such as moldability and heat resistance, the Shore A hardness of the resin composition of the present embodiment, measured in accordance with JIS K 7215:1986, is preferably 50 or more and 120 or less, more preferably 55 or more and 120 or less, even more preferably 60 or more and 110 or less, even more preferably 65 or more and 110 or less, and even more preferably 70 or more and 100 or less. The Shore A hardness is measured in accordance with JIS K 7215:1986 using a type D durometer at 23°C for a pressed sheet of the resin composition of the present embodiment.

[0054] The Vicat softening point of the resin composition of this embodiment, measured under a load of 10 N in accordance with JIS K 7206:2016, is preferably 30°C or higher and 100°C or lower, more preferably 30°C or higher and 90°C or lower, even more preferably 32°C or higher and 80°C or lower, and even more preferably 34°C or higher and 70°C or lower, from the viewpoint of further improving the balance of basic physical properties such as heat resistance, flexibility, and processability and handleability.

[0055] The Vicat softening point is measured as follows. Using a press sheet of the resin composition of this embodiment, a thermal deformation tester was used in accordance with JIS K 7206:2016. A needle indenter was placed at the center of the top of the press sheet so that it was in contact with the press sheet. A load of 10 N was applied while the temperature of the heat transfer medium, silicone oil, was increased from 20°C at a rate of 50°C / h, and the temperature of the heat transfer medium was measured when the needle indenter penetrated 1 mm from the surface of the press sheet.

[0056] The melting point of the resin composition of this embodiment, measured using a differential scanning calorimeter (DSC) in accordance with JIS K 7121:2012, is preferably 40°C or higher and 140°C or lower, more preferably 45°C or higher and 130°C or lower, even more preferably 50°C or higher and 120°C or lower, even more preferably 55°C or higher and 110°C or lower, and even more preferably 60°C or higher and 100°C or lower, from the viewpoint of further improving the performance balance between basic physical properties such as heat resistance and flexibility and the physical properties of the resin compound.

[0057] The press sheet of the resin composition of this embodiment used for the above physical properties is produced as follows. The resin composition of this embodiment was heated at 160°C for 5 minutes, during which time it was degassed 5 times, and then heated at 160°C for 5 minutes under a pressure of 9.8 MPa (100 kg / cm 2 ) conditions, then press-molded at 20°C for 5 minutes under 14.7 MPa (150 kg / cm 2 ) and press molded under the conditions to produce a 3 mm thick press sheet.

[0058] 2. Molded body The molded article of the present embodiment can be obtained by molding the resin composition of the present embodiment. The molding method is not limited, and known molding methods such as extrusion molding, injection molding, compression molding, and blow molding can be used, and the molded article can be obtained by molding into various shapes such as a sheet shape, a film shape, a plate shape, and other three-dimensional shapes. The molded article of the present embodiment may be made solely of the resin composition of the present embodiment, or may be made of the resin composition of the present embodiment and other components. The molded article of this embodiment may be a part or the whole of a member.

[0059] Furthermore, the surface of the molded article of this embodiment may be subjected to a flame treatment, a corona treatment, a plasma treatment, a hard coat treatment with an inorganic or organic compound, an antistatic treatment, an antireflection treatment, an electromagnetic shielding treatment, etc., within the scope of not impairing the effects of the present invention. These treatments can be performed on the surface of the molded article by vapor deposition, sputtering, dipping, thermal transfer, etc.

[0060] The molded article of the present embodiment is not particularly limited, and can be used in a wide range of fields, such as optical materials, electronic components, various mechanical components, foams, sheets, films, pipes, tubes, toys, and daily necessities.

[0061] 3.Wire sheathing material The wire covering material of the present embodiment includes the resin composition of the present embodiment or the molded article of the present embodiment. The wire covering material of the present embodiment is a material for protecting the surface of an electric wire, which is a conductor. A power cable generally has a layer structure of, from the inside out, a conductor / inner semiconductive layer / insulating layer / outer semiconductive layer / shielding layer / sheath, and the wire coating material refers to the inner semiconductive layer / insulating layer / outer semiconductive layer / shielding layer / sheath portion on the outside of the conductor. The resin composition of the present embodiment may be used in any of these layers, but is preferably used in one or two layers selected from the group consisting of the insulating layer and the semiconductive layer because of its excellent melt physical properties.

[0062] The wire covering material may contain a filler, a flame retardant, etc., from the viewpoint of further improving the balance of performance among insulation, flame retardancy, and heat dissipation. The wire covering material of the present embodiment may also contain components contained in conventionally known wire covering materials. In addition, the wire coating material may be directly coated on the outer periphery of the conductor, or other intermediate members, such as a shield conductor or other insulators, may be interposed between the conductor and the wire coating material.

[0063] The material and diameter of the conductor are not particularly limited and can be determined appropriately depending on the application. The thickness of the wire coating is also not particularly limited and can be determined appropriately taking into account the conductor diameter, etc.

[0064] The wire coating material can be produced by melt-kneading the resin composition according to the present embodiment using a conventionally known kneader such as a Banbury mixer, a pressure kneader, or a roll, and then extruding the resin composition onto the outer periphery of a conductor using a conventionally known extrusion molding machine.

[0065] 4. Solar cell encapsulant The solar cell encapsulant of this embodiment includes the resin composition of this embodiment or the molded article of this embodiment.

[0066] The thickness of the solar cell encapsulant of this embodiment is preferably 0.1 mm or more and 10 mm or less, more preferably 0.2 mm or more and 5 mm or less, and even more preferably 0.3 mm or more and 2 mm or less. When the thickness of the laminated glass interlayer is at least the above lower limit, the mechanical strength of the laminated glass interlayer can be further improved. When the thickness of the laminated glass interlayer is at most the above upper limit, the optical properties and interlayer adhesion of the resulting laminated glass can be further improved.

[0067] The method for producing the solar cell encapsulant of this embodiment is not particularly limited, and any conventionally known production method can be used. The solar cell encapsulant of this embodiment can be produced by, for example, press molding, extrusion molding, T-die molding, injection molding, compression molding, cast molding, calendar molding, inflation molding, or the like.

[0068] 5.Laminated sheets for solar cells The laminated sheet for a solar cell of this embodiment contains the resin composition of this embodiment. The solar cell laminate sheet is a solar cell in which an encapsulant and a back sheet for protecting a solar cell element from the outside air are integrated. The resin composition of the present embodiment has an excellent balance of basic physical properties, melt physical properties, and resin compound physical properties, and therefore can be used as an adhesive layer between the encapsulant and the back sheet in the solar cell laminate sheet of the present embodiment. The thickness of the laminated sheet for a solar cell is not limited as long as the encapsulant can exhibit its performance as an encapsulant.

[0069] As the solar cell element, various types of solar cell elements can be used, such as silicon-based elements such as single crystal silicon, polycrystalline silicon, and amorphous silicon, and III-V and II-VI group compound semiconductor elements such as gallium-arsenide, copper-indium-selenium, and cadmium-tellurium.

[0070] 6. Foam molding The foam molded article of this embodiment is obtained by heating and foaming the resin composition of this embodiment. When the resin composition of the present embodiment is used for a foam molded article, the resin composition may contain a chemical foaming agent, a foaming assistant, and the like, as needed. The foamed molded article of the present embodiment uses the resin composition of the present embodiment, and therefore has an excellent balance of basic physical properties, melt physical properties, and resin compound physical properties, and is widely used in applications such as heat insulation materials, sound absorbing materials, shoe soles, buoys, automobile parts, and miscellaneous goods.

[0071] When the resin composition of this embodiment is used for a foamed molded article, the resin composition can be melt-kneaded, and then, if necessary, pelletized, and molded into a shape suitable for the intended product, for example, into a sheet using a T-die, roll, etc. The molding temperature for the resin composition varies depending on the composition of the resin composition and the molding method, but it is generally best to select a temperature suitable for the molding method within the temperature range of 100 to 200°C.

[0072] To form a foamed molded article from the molded article obtained in this manner, foaming can be carried out using a press, furnace, foaming bath, etc. When electron beam crosslinking is carried out, the molded article can be irradiated with electron beams before foaming to effect crosslinking. Foaming conditions vary depending on the types of chemical foaming agent, foaming assistant, etc., but it is generally best to select a temperature in the range of 150 to 250°C that suits the foaming method. The expansion ratio when foaming from the molded body is, for example, 2.1 times or more, and from the viewpoint of further improving cushioning properties, preferably 3.1 times or more, and from the viewpoint of further improving lightness, preferably 10 times or less, more preferably 8 times or less.

[0073] 7. Footwear The footwear of this embodiment is made of the foam molded article of this embodiment. The foam molded article of this embodiment is used as a counter member that constitutes the heel portion of the footwear of this embodiment. Examples of footwear include sports shoes, leather shoes, chemical shoes, sandals, etc.

[0074] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0075] The present embodiment will be described in detail below with reference to examples, etc. However, the present embodiment is not limited to the descriptions of these examples.

[0076] [material] The following components were used. The content of structural units derived from vinyl acetate was measured by titration in accordance with JIS K 7192:1999. The melt flow rate (MFR) was measured at 190°C under a load of 2160 g in accordance with JIS K 7210:1999. The density was measured in accordance with JIS K 7112:1999. The biomass content was measured in accordance with ASTM D6866.

[0077] <Carbohydrate-based polymer (A)> Carbohydrate polymer 1 = thermoplastic starch (product name: SKT 10R476 SANKYO GOLDEN STARCH, manufactured by Sankyo Chemical Co., Ltd., starch content: 75% by mass, glycerin content: 25% by mass, biomass content: 100% by mass)

[0078] <Ethylene-unsaturated ester copolymer (B)> Ethylene-vinyl acetate copolymer 1 = Content of ethylene-derived structural units: 67% by mass, Content of vinyl acetate-derived structural units: 33% by mass, MFR (190°C, 2160g load): 14g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 2 = Content of structural units derived from ethylene: 72% by mass, Content of structural units derived from vinyl acetate: 28% by mass, MFR (190°C, 2160g load): 6g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 3 = Content of ethylene-derived structural units: 75% by mass, Content of vinyl acetate-derived structural units: 25% by mass, MFR (190°C, 2160g load): 2g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 4 = Content of ethylene-derived structural units: 80% by mass, Content of vinyl acetate-derived structural units: 20% by mass, MFR (190°C, 2160g load): 20g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 5 = Content of ethylene-derived structural units: 81% by mass, Content of vinyl acetate-derived structural units: 19% by mass, MFR (190°C, 2160g load): 2.5g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 6 = Content of ethylene-derived structural units: 84% by mass, Content of vinyl acetate-derived structural units: 16% by mass, MFR (190°C, 2160g load): 2.7g / 10min, Biomass content: 0% by mass Ethylene-vinyl acetate copolymer 7 = Content of ethylene-derived structural units: 86% by mass, Content of vinyl acetate-derived structural units: 14% by mass, MFR (190°C, 2160g load): 3.5g / 10min, Biomass content: 0% by mass

[0079] [Examples 1 to 6 and Comparative Examples 1 to 3] <Preparation of Resin Composition (P)> The materials were premixed in the blending ratios (unit: mass%) shown in Table 1, fed into a twin-screw extruder with a screw diameter of 30 mm, melt-kneaded under the following extrusion conditions or melt-kneading conditions, and granulated to prepare pellets of resin composition (P).

[0080] The extrusion conditions and melt-kneading conditions in the twin-screw extruder are as follows. Screw effective length L / D: 35 ·Extruder setting temperature (℃): C1 (110℃), C2 (160℃), C3 (180℃), C4 (180℃), C5 (180℃), H (180℃), D (180℃) Screw rotation speed: 200 rpm Screen mesh: 60 / 60 Output: 15kg / h

[0081] [Content of structural units derived from vinyl acetate in resin composition (P)] The content (mass%) of structural units derived from vinyl acetate in the resin composition (P) obtained in each example was calculated from the content of structural units derived from vinyl acetate in the ethylene-unsaturated ester copolymer (B) used as a raw material and the content of the ethylene-unsaturated ester copolymer (B) when the entire resin composition (P) was taken as 100 mass%.

[0082] [MFR of resin composition (P)] The MFR (g / 10 min) of the resin composition (P) obtained in each example was measured in accordance with JIS K 7210:1999 under conditions of 190° C. and a load of 2160 g.

[0083] [Density of resin composition (P)] The density (kg / m) of the resin composition (P) obtained in each example 3 ) was measured in accordance with JIS K 7112:1999.

[0084] <Press sheet production> The resin composition (P) obtained in each example was heated at 160°C for 5 minutes, during which time it was degassed 5 times, and then heated at 160°C for 5 minutes under 9.8 MPa (100 kg / cm 2 ) conditions, then press-molded at 20°C for 5 minutes under 14.7 MPa (150 kg / cm 2 ) and press-molded into a 3 mm thick press sheet.

[0085] The obtained press sheets were evaluated for stress at break, elongation at break, Shore A hardness, Vicat softening point and melting point according to the following methods.

[0086] [Stress at break and elongation at break] The stress at break (based on JIS K 7161-1:2014) and elongation at break (based on JIS K 7161-2:2014) of the pressed sheets obtained in each example were measured using a tensile tester. Dumbbell-shaped test specimens were cut from the pressed sheets in accordance with the above JIS standard and subjected to tension measurements under conditions of 90 mm chuck distance, 50 mm / min tension speed, 23°C, and 50% RH. The elongation at break represents the elongation of the test specimen between the designated gauge points immediately before breakage in the tensile test. The stress at break is the tensile force at the break point during the tensile test divided by the initial cross-sectional area of the test specimen.

[0087] [Shore A hardness] The Shore A hardness of the pressed sheet obtained in each example was measured in accordance with JIS K 7215: 1986. The pressed sheet was cut into a test piece measuring 100 mm in length, 20 mm in width, and 3 mm in thickness, and the measurement was carried out using a Type A durometer at 23°C.

[0088] [Vicat softening point] The Vicat softening point (°C) of the pressed sheet obtained in each example was measured in accordance with JIS K 7206: 2016. Using a thermal deformation testing device, a needle indenter was placed at the center of the top of the pressed sheet so that it was in contact with the pressed sheet. While applying a load of 10 N, the temperature of the heat transfer medium, silicone oil, was increased from 20°C at a rate of 50°C / h, and the temperature of the heat transfer medium was measured when the needle indenter penetrated 1 mm from the surface of the pressed sheet.

[0089] [Melting point] The melting point (°C) of the pellets of the resin composition (P) obtained in each example was measured using a differential scanning calorimeter (DSC) in accordance with JIS K 7121:2012.

[0090] [Table 1]

[0091] As is clear from Table 1, although the resin compositions (P) of Examples 1 and 2 contained biomass-derived raw materials, the MFR, density, stress at break, elongation at break, Shore A hardness, Vicat softening point, and melting point were all the same in terms of the content of structural units derived from vinyl acetate, and were equivalent to those of the resin composition (P) (Comparative Example 1) that used only fossil fuel-derived raw materials. The same was true in the comparison between Examples 3 and 4 and Comparative Example 2, and in the comparison between Examples 5 and 6 and Comparative Example 3.

Claims

1. A resin composition comprising: (A) a carbohydrate-based polymer containing starch and a plasticizer; and (B) an ethylene-unsaturated ester copolymer.

2. The resin composition of claim 1 , wherein the plasticizer comprises glycerin.

3. 3. The resin composition according to claim 1, wherein the content of the carbohydrate-based polymer (A) in the resin composition is 1% by mass or more and 99% by mass or less, when the total resin components of the resin composition are 100% by mass.

4. The resin composition according to any one of claims 1 to 3, wherein the ethylene-unsaturated ester copolymer (B) comprises an ethylene-vinyl acetate copolymer.

5. The resin composition according to any one of claims 1 to 4, wherein the content of structural units derived from unsaturated ester in the ethylene-unsaturated ester copolymer (B) is 4% by mass or more and 46% by mass or less, when the entire ethylene-unsaturated ester copolymer (B) is taken as 100% by mass.

6. The resin composition according to any one of claims 1 to 5, wherein the ethylene-unsaturated ester copolymer (B) contains a petroleum-derived raw material.

7. The resin composition according to any one of claims 1 to 6, wherein the content of the ethylene-unsaturated ester copolymer (B) in the resin composition is 1% by mass or more and 99% by mass or less, when the total resin components of the resin composition are taken as 100% by mass.

8. The resin composition according to any one of claims 1 to 7, wherein the melt mass flow rate (MFR) measured in accordance with JIS K 7210:1999 under conditions of 190 ° C. and a load of 2160 g is 0.1 g / 10 min or more and 50 g / 10 min or less.

9. A molded article obtained by molding the resin composition according to any one of claims 1 to 8.

10. A wire covering material comprising the resin composition according to any one of claims 1 to 8 or the molded article according to claim 9.

11. A solar cell encapsulant comprising the resin composition according to any one of claims 1 to 8 or the molded article according to claim 9.

12. A laminated sheet for solar cells comprising the resin composition according to any one of claims 1 to 8.

13. A foamed molded article obtained by heating and foaming the resin composition according to any one of claims 1 to 8.

14. Footwear comprising the foamed molded article according to claim 13.

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