Resin composition and molded article containing same

Abstract

The present invention addresses the problem of providing a resin composition which, despite containing an inorganic powder that contains manganese and iron, has high elongation and tensile strength and excellent processability. This resin composition, which solves the problem, contains a thermoplastic resin that includes a polyolefin-based resin, an inorganic powder and a metal deactivation agent. The content of the inorganic powder is 50 mass% to 90 mass% inclusive, the amount of elemental manganese in the inorganic powder is 0.001 mass% to 0.500 mass% inclusive, the amount of elemental iron in the inorganic powder is 0.01 mass% to 1.00 mass% inclusive, and the content of the metal deactivation agent is 0.2 mass% to 1.0 mass% inclusive.

Description

Resin composition and molded article containing the same

[0001] The present invention relates to a resin composition and a molded article containing the same.

[0002] Conventionally, a resin composition in which an inorganic powder such as calcium carbonate powder is highly filled in a thermoplastic resin has been known (for example, Patent Document 1). Such a resin composition has advantages of a small amount of thermal shrinkage and excellent impact resistance. In recent years, taking advantage of the characteristics of the resin composition, further expansion to a wider range of applications has been studied.

[0003] Japanese Patent Application Laid-Open No. 2023-77472

[0004] Generally, when processing a resin composition, stretching treatment and various molding treatments are performed according to its use. Therefore, excellent processability is required for the resin composition. Here, in recent years, due to efforts towards the environment, waste containing calcium such as steel slag and carbide slag, or calcium extracted from the waste, is reacted with carbon dioxide that causes the greenhouse effect to prepare an inorganic powder (calcium carbonate). When the present inventors conducted studies, it was revealed that when an inorganic powder using such slag as a raw material, particularly an inorganic powder containing iron or manganese, is used in the resin composition, the processability of the resulting resin composition, particularly elongation and tensile strength, tends to be low.

[0005] The present invention has been made in view of the above problems of the prior art. Specifically, an object is to provide a resin composition having high elongation and tensile strength and excellent processability, and a molded article containing the same, despite containing an inorganic powder containing manganese or iron.

[0006] The present inventors have found that by combining a thermoplastic resin, an inorganic powder containing a certain amount of manganese element and iron element, and a metal deactivator, the elongation and tensile strength of the resin composition are significantly improved and its processability is enhanced, and thus completed the present invention.

[0007] One aspect of the present invention provides the following resin composition. [1] A resin composition comprising a thermoplastic resin containing a polyolefin-based resin, an inorganic powder, and a metal deactivator, wherein the content of the inorganic powder is 50% by mass to 90% by mass, the amount of elemental manganese in the inorganic powder is 0.001% by mass to 0.500% by mass, the amount of elemental iron in the inorganic powder is 0.01% by mass to 1.00% by mass, and the content of the metal deactivator is 0.2% by mass to 1.0% by mass. [2] The resin composition according to [1], wherein the thermoplastic resin comprises a polypropylene-based resin and / or a polyethylene-based resin. [3] The resin composition according to [1] or [2], wherein the inorganic powder is calcium carbonate powder. [4] The resin composition according to [3], wherein the calcium carbonate powder is calcium carbonate powder made from steel slag and / or carbide slag. [5] The resin composition according to [3] or [4], wherein the calcium carbonate powder has an average particle size of 0.7 μm or more and 10.0 μm or less as measured by an air permeability method in accordance with JIS M-8511. [6] The metal deactivator is selected from the group consisting of melamine, 3-salicylamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine, N,N'-diphenyloxamide, N-salicyl-N'-salicylhydrazine, N,N'-bis(salicyl)hydrazine, N,N'-bis(3,5-di-tert-butyl-4- The resin composition according to any one of [1] to [5], which contains one or more compounds selected from the group consisting of N,N'-bis(salicyloyl)propionyl hydrazine, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N,N'-bis(salicyloyl)oxylyl dihydrazide, and N,N'-bis(salicyloyl)thiopropionyl dihydrazide.[7] The resin composition according to [6], wherein the metal deactivator comprises one or more compounds selected from the group consisting of melamine, 3-salicylamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, and 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine. [8] The resin composition according to [7], wherein the metal deactivator is melamine.

[0008] One aspect of the present invention provides the following molded article: [9] A molded article comprising the resin composition according to any one of [1] to [8] above.

[0009] According to the present invention, there are provided a resin composition which has high elongation and tensile strength and excellent processability despite containing inorganic powders including manganese and iron, and a molded article containing the same.

[0010] Hereinafter, one embodiment of the present invention will be described in detail. However, the present invention is not limited to this embodiment. In addition, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower limit and upper limit.

[0011] 1. Resin Composition The resin composition of this embodiment contains a thermoplastic resin containing a polyolefin resin, an inorganic powder, and a metal deactivator. The amount of manganese element in the inorganic powder is 0.001% by mass or more and 0.500% by mass or less, and the amount of iron element is 0.01% by mass or more and 1.00% by mass or less. As described above, when the inorganic powder contains manganese element or iron element, there is a problem that the processability of the resin composition tends to be poor. In contrast, when the resin composition contains a certain amount of metal deactivator along with the inorganic powder and thermoplastic resin, the elongation and tensile strength of the resin composition are significantly improved, and the processability is very good, as demonstrated in the examples described below. Below, each component in the resin composition and the method for producing the resin composition are described.

[0012] (Thermoplastic resin) The thermoplastic resin may contain a polyolefin-based resin, and may contain only a polyolefin-based resin, or may contain a polyolefin-based resin and other resins. However, it is preferable that the thermoplastic resin contains a polyolefin-based resin as a main component. More specifically, the amount of polyolefin-based resin in the thermoplastic resin is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. The thermoplastic resin may contain only one type of polyolefin-based resin, or may contain two or more types.

[0013] Polyolefin resins are resins whose main component is an olefin-derived structural unit, and the amount of the olefin-derived structural unit relative to all structural units constituting the polyolefin resin is 50% by mass or more. The polyolefin resin may be a homopolymer of one type of olefin, a copolymer of two or more types of olefin, or a copolymer of one or more types of olefin and one or more other monomers (monomers other than olefins). The amount of the olefin-derived structural unit in the polyolefin resin is preferably 75% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0014] Examples of the olefin include ethylene and α-olefins having 3 to 10 carbon atoms, and specific examples thereof include ethylene, propylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 4-methylpentene-1, 3-methyl-1-hexene, and 1-octene. The polyolefin resin may contain only one type of structural unit derived from these, or may contain two or more types.

[0015] The other monomers are not particularly limited as long as they do not impair the objectives and effects of this embodiment. Examples of other monomers include diene monomers such as 1,4-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, dicyclopentadiene (DCPD), ethylidenenorbornene (ENB), norbornadiene, and 5-vinyl-2-norbornene; acid (or acid anhydride)-modified olefins such as maleic anhydride-modified olefins; and (meth)acrylates such as methyl (meth)acrylate. The polyolefin resin may contain only one type of structural unit derived from these monomers, or may contain two or more types.

[0016] The polyolefin resin is preferably a polypropylene resin and / or a polyethylene resin. The polypropylene resin and the polyethylene resin may be virgin resin, recycled resin, or a mixture thereof.

[0017] In this specification, the term "polypropylene resin" refers to a resin containing 50% by mass or more of structural units derived from propylene, and includes propylene homopolymers and copolymers of propylene with other monomers (propylene copolymers). Propylene homopolymers include isotactic, syndiotactic, atactic, hemiisotactic, and linear or branched polypropylenes exhibiting various stereoregularities. The stereoregularity of propylene is １３ The propylene copolymer can be identified by C-NMR or the like. The propylene copolymer may be a random copolymer or a block copolymer. The propylene copolymer may be a binary copolymer of propylene and another monomer, or a multi-component copolymer of propylene and two or more other monomers. Examples of preferred copolymerization components (other monomers) include ethylene, α-olefins having 4 or more carbon atoms, tetrafluoroethylene, vinyl acetate, etc. In this embodiment, the polypropylene-based resin is preferably a propylene homopolymer or a propylene copolymer containing less than 5 mass% of structural units derived from other monomers.

[0018] Meanwhile, in this specification, the term "polyethylene-based resin" refers to a resin containing 50% by mass or more of structural units derived from ethylene, and includes ethylene homopolymers and copolymers of ethylene and other monomers (ethylene copolymers). Examples of ethylene homopolymers include high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene, and linear low-density polyethylene (LLDPE). The ethylene copolymer may be a binary copolymer of ethylene and other monomers, or a multi-component copolymer of ethylene and two or more other monomers. Examples of preferred copolymerization components (other monomers) include vinyl acetate and α-olefins having 3 or more carbon atoms. In this embodiment, the polyethylene-based resin is preferably an ethylene homopolymer or an ethylene copolymer containing less than 5% by mass of structural units derived from other monomers.

[0019] Furthermore, as described above, the thermoplastic resin may further contain a resin other than the polyolefin-based resin. Examples of the resin other than the polyolefin-based resin include thermoplastic resins such as poly(meth)acrylic acid (ester), polyvinyl acetate, polyacrylonitrile, polystyrene, ABS resin, polycarbonate, polyamide, polyvinyl alcohol, petroleum hydrocarbon resin, and coumarone-indene resin; and elastomers such as styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-butadiene-ethylene copolymer, styrene-isoprene-ethylene copolymer, acrylonitrile-butadiene copolymer, and fluorine-based elastomer.

[0020] The content of the thermoplastic resin in the resin composition is preferably 10% by mass or more and 49.8% by mass or less, more preferably 15% by mass or more and 45% by mass or less, and even more preferably 18% by mass or more and 43% by mass or less. The mass ratio of the amount of the thermoplastic resin to the inorganic powder (described below) is preferably in the range of 50:50 to 10:90, more preferably 45:55 to 15:85. When the amount of the thermoplastic resin is within this range, the resin composition not only has a small amount of thermal shrinkage and good impact resistance, but also tends to have even better processability.

[0021] (Inorganic Powder) The inorganic powder is a powder made of an inorganic substance, and the amount of manganese element is 0.001% by mass to 0.500% by mass, and the amount of iron element is 0.01% by mass to 1.00% by mass. The amount of manganese element and the amount of iron element in the inorganic powder can be determined using an ICP emission spectrometer or the like. Note that the manganese and iron may be contained in the inorganic powder as simple substances, or may be contained as compounds with other elements, such as oxides, sulfides, nitrides, and sulfides.

[0022] The type of inorganic substance is selected depending on the intended use of the resin composition. Examples of inorganic substances include carbonates, sulfates, silicates, phosphates, borates, oxides, and hydrates of calcium, magnesium, aluminum, titanium, zinc, silicon, barium, molybdenum, sodium, and potassium. Examples of inorganic substances also include inorganic carbon compounds. Specific examples of inorganic substances include calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay (e.g., talc, kaolin, etc.), aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, sodium sulfate, potassium titanate, bentonite, wollastonite, dolomite, and graphite. These may be synthetic or derived from natural minerals. The inorganic powder may contain only one or more of these substances.

[0023] The shape of the inorganic powder is not particularly limited, and may be any of particles, flakes, granules, fibers, etc. In the case of particles, they may be spherical as obtained by a general synthesis method, or irregularly shaped as obtained by pulverizing collected natural minerals.

[0024] Preferred examples of inorganic powders include calcium carbonate, magnesium carbonate, dolomite, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, and magnesium hydroxide powder, and calcium carbonate powder is particularly preferred. Calcium carbonate may be prepared by a synthetic method, so-called light calcium carbonate. On the other hand, calcium carbonate such as limestone may also be used. ３ The calcium carbonate may be so-called heavy calcium carbonate, which is obtained by mechanically crushing and classifying a natural raw material containing the above as a main component. Furthermore, light calcium carbonate and heavy calcium carbonate may be combined.

[0025] In this embodiment, the calcium carbonate powder is preferably a powder made from concrete sludge, steel slag, carbide slag, waste concrete, coal ash, biomass ash, incineration ash, waste gypsum, alkaline wastewater, etc., and more preferably a powder made from steel slag and / or carbide slag. Calcium carbonate powders made from these raw materials often contain the aforementioned amounts of manganese and iron.

[0026] Here, the inorganic powder may be surface-modified or may not be surface-modified. From the viewpoint of dispersibility of the inorganic powder, surface-modified is preferable. Examples of surface modification methods for inorganic powders include physical modification methods using plasma treatment, etc., and chemical modification methods using coupling agents, surfactants, etc. Examples of coupling agents that can be used in chemical modification methods include silane coupling agents and titanium coupling agents. Any of anionic, cationic, nonionic, and amphoteric surfactants can be used as surfactants, and examples thereof include higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid salts.

[0027] The average particle size of the inorganic powder is not particularly limited and can be appropriately selected depending on the shape and thickness of the molded article, but is preferably 0.7 μm to 10.0 μm, more preferably 0.7 μm to 6.0 μm, and even more preferably 1.0 μm to 4.0 μm. The average particle size of the inorganic powder in this specification refers to a value calculated from the results of measuring the specific surface area using an air permeability method in accordance with JIS M-8511. An example of a measuring instrument is the SS-100 specific surface area measuring device manufactured by Shimadzu Corporation. If the average particle size of the inorganic powder is 10.0 μm or less, the inorganic powder will be less likely to fall off from molded articles obtained from the resin composition. It is preferable that the inorganic powder does not contain particles with a particle size of 45 μm or more in its particle size distribution. On the other hand, if the average particle size is 0.7 μm or more, the viscosity when kneaded with the thermoplastic resin will tend to fall within the desired range.

[0028] The amount of inorganic powder in the resin composition of this embodiment may be from 50% by mass to 90% by mass, more preferably from 55 parts by mass to 85 parts by mass, and even more preferably from 57 parts by mass to 82 parts by mass, relative to the total amount of the resin composition. As described above, the mass ratio of the thermoplastic resin to the inorganic powder is preferably in the range of 50:50 to 10:90. When the amount of inorganic powder is within this range, not only is the amount of thermal shrinkage of the resin composition small and the impact resistance good, but the processability is also likely to be further improved.

[0029] (Metal Deactivator) The metal deactivator may be any compound that interacts with the manganese and iron elements contained in the inorganic powder and can deactivate them. Specific examples of the metal deactivator include melamine, 3-salicylamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine, N,N'-diphenyloxamide, N-salicyl-N'-salicylhydrazine, N,N'-bis(salicyl)hydrazine, and N,N'-biphenyloxamide. Examples of suitable metal deactivators include bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N,N'-bis(salicyloyl)oxylyl dihydrazide, and N,N'-bis(salicyloyl)thiopropionyl dihydrazide. The resin composition may contain only one type of metal deactivator, or may contain two or more types.

[0030] Among the above, melamine, 3-salicylamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, and 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine are preferred, with melamine being particularly preferred. When the metal deactivator is melamine, the elongation and tensile strength of the resin composition tend to be significantly increased, as shown in the examples below. This is thought to be because melamine not only deactivates the manganese and iron elements in the inorganic powder, but also because melamine (the metal deactivator) interacts with the thermoplastic resin and the inorganic powder.

[0031] The amount of metal deactivator in the resin composition of this embodiment may be 0.2% by mass or more and 1.0% by mass or less, more preferably 0.2 parts by mass or more and 0.8 parts by mass or less, and even more preferably 0.3 parts by mass or more and 0.6 parts by mass or less, relative to the total amount of the resin composition. When the amount of metal deactivator is 0.2% by mass or more, the effect of adding the metal deactivator is easily obtained. On the other hand, if the amount of metal deactivator is excessively large, the elongation and tensile strength of the resin composition tend to decrease, but when the amount is 1.0% by mass or less, good elongation and tensile strength are easily obtained.

[0032] (Other Components) The resin composition may further contain components other than those described above, provided that the purpose and effect of the present embodiment are not impaired. Examples of the other components include lubricants, plasticizers, colorants, antioxidants, flame retardants, foaming agents, and flow adjusters.

[0033] Examples of lubricants include fatty acid-based lubricants such as stearic acid, hydroxystearic acid, complex stearic acid, and oleic acid; fatty alcohol-based lubricants; aliphatic amide-based lubricants such as stearamide, oxystearamide, oleylamide, erucylamide, ricinoleamide, behenamide, methylolamide, methylenebisstearamide, methylenebisstearobenamide, bisamic acids of higher fatty acids, and complex amides; aliphatic ester-based lubricants such as n-butyl stearate, methyl hydroxystearate, polyhydric alcohol fatty acid esters, saturated fatty acid esters, and ester waxes; and fatty acid metal soap-based lubricants such as zinc stearate and magnesium stearate.

[0034] Examples of plasticizers include triethyl citrate, acetyl triethyl citrate, dibutyl phthalate, diaryl phthalate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, di(2-ethylhexyl) phthalate, di-2-methoxyethyl phthalate, dibutyl tartrate, o-benzoyl benzoate ester, diacetin, epoxidized soybean oil, etc. The resin composition may contain these alone or two or more kinds.

[0035] The coloring material may be any of known organic pigments, inorganic pigments, or dyes. Specific examples of coloring materials include organic pigments such as azo-based, anthraquinone-based, phthalocyanine-based, quinacridone-based, isoindolinone-based, dioxazine-based, perinone-based, quinophthalone-based, and perylene-based pigments; and inorganic pigments such as ultramarine, titanium yellow, and chromium oxide. The resin composition may contain these pigments alone or in combination.

[0036] Examples of antioxidants include phosphorus-based antioxidants, phenol-based antioxidants, and pentaerythritol-based antioxidants. The resin composition may contain these antioxidants alone or in combination. Phosphorus-based antioxidant stabilizers, more specifically, phosphorus-based antioxidant stabilizers such as phosphite esters and phosphate esters, are preferably used. Examples of phosphite esters include triesters, diesters, and monoesters of phosphorous acid, such as triphenyl phosphite, trisnonylphenyl phosphite, and tris(2,4-di-t-butylphenyl) phosphite.

[0037] Examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris(nonylphenyl)phosphate, 2-ethylphenyldiphenyl phosphate, and the like.

[0038] Examples of the phenolic antioxidant include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-t-butyl-6-(3′-t-butyl-5′-methyl-2′-hydroxybenzyl)-4-methylphenylacrylate, 2,6-di-t-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester, and tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane.

[0039] The flame retardant is not particularly limited, but may be, for example, a halogen-based flame retardant, or a non-phosphorus-based halogen-based flame retardant such as a phosphorus-based flame retardant or a metal hydrate. The resin composition may contain one or more of these.

[0040] Examples of halogen-based flame retardants include halogenated bisphenol compounds such as halogenated bisphenylalkanes, halogenated bisphenylethers, halogenated bisphenylthioethers, and halogenated bisphenylsulfones, and bisphenol-bis(alkyl ether) compounds such as brominated bisphenol A, brominated bisphenol S, chlorinated bisphenol A, and chlorinated bisphenol S. Examples of phosphorus-based flame retardants include aluminum tris(diethylphosphinate), bisphenol A bis(diphenyl phosphate), triarylisopropyl phosphate, cresyl di-2,6-xylenyl phosphate, and aromatic condensed phosphate esters. Examples of metal hydrates include aluminum trihydrate, magnesium dihydroxide, and combinations thereof.

[0041] The flame retardant may be combined with a flame retardant synergist. Examples of the flame retardant synergist include antimony oxides such as antimony trioxide and antimony pentoxide, and other known flame retardant synergists.

[0042] The foaming agent is not particularly limited as long as it is a compound that can generate bubbles when mixed with or injected under pressure into a composition that is in a molten state in a melt kneader. Examples of foaming agents include those that change phase from solid to gas to generate bubbles, those that change phase from liquid to gas to generate bubbles, and gas itself.

[0043] Examples of blowing agents include aliphatic hydrocarbons such as propane, butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclobutane, cyclopentane, and cyclohexane; halogenated hydrocarbons such as chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, dichloromethane, dichlorofluoromethane, dichlorodifluoromethane, chloromethane, chloroethane, dichlorotrifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, tetrachlorodifluoroethane, and perfluorocyclobutane; inorganic gases such as carbon dioxide, nitrogen, and air; and water.

[0044] The foaming agent may contain an active ingredient of the foaming agent together with a carrier resin. Examples of the carrier resin include crystalline olefin resins such as crystalline propylene. Examples of the active ingredient include bicarbonates. Among these, bicarbonates are preferred. A foaming agent concentrate containing a crystalline polypropylene resin as the carrier resin and bicarbonates as the thermal decomposition type foaming agent is preferred.

[0045] Known flow modifiers can also be used. Examples of flow modifiers include peroxides such as dialkyl peroxides, for example, 1,4-bis[(t-butylperoxy)isopropyl]benzene. Depending on the type of thermoplastic resin used, these peroxides can also function as crosslinking agents. In particular, when the thermoplastic resin (polyolefin resin) contains structural units derived from a diene, the diene may be crosslinked by the peroxide.

[0046] Examples of antistatic agents include fatty acid diethanolamides such as lauryl diethanolamide and stearyl diethanolamide; and hydroxyl group-containing compounds such as alcoholamine compounds. Alcoholamines, such as monoethanolamine, diethanolamine, and triethanolamine, are particularly preferred. Two or more types of antistatic agents can also be used in combination. These antistatic agents may be supported on calcium silicate, calcium carbonate, or the like. The number of carbon atoms in the acyl group of the fatty acid diethanolamide is preferably 8 to 22 inclusive, as this provides sufficient antistatic effect.

[0047] (Shape of Resin Composition) The shape of the resin composition of this embodiment is not particularly limited, and can be any shape, such as particulate, pellet, or block. When the resin composition is in pellet form, the shape of the pellet is not particularly limited, and may be any shape, such as cylindrical, spherical, or oval sphere. The size is also not particularly limited, and is selected appropriately depending on the shape. For example, in the case of spherical pellets, the diameter may be 1 to 10 mm. In the case of oval sphere pellets, the major axis may be about 1 to 10 mm, and the aspect ratio may be about 0.1 to 1.0. In the case of cylindrical pellets, the diameter may be about 1 to 10 mm, and the height may be about 1 to 10 mm.

[0048] (Method for producing resin composition) The method for producing the resin composition is not particularly limited. Any method may be used as long as it can sufficiently mix the above-mentioned thermoplastic resin, inorganic powder, metal deactivator, and other components as necessary, and the resin composition can be prepared, for example, by melt kneading. In this case, all components may be mixed and then melt kneaded, or only some of the components may be melt kneaded first and the remaining components may be kneaded later. The device for performing melt kneading is not particularly limited, and a general extruder, kneader, Banbury mixer, etc. can be used. In particular, from the viewpoint of obtaining a resin composition with a uniform composition, kneading with a twin-screw kneader is preferred.

[0049] 2. Molded Article This embodiment also provides a molded article made from the resin composition described above. The molding method for the resin composition described above is not particularly limited and may be appropriately selected depending on the intended use. The resin composition described above has excellent processability and tensile strength, so it can be molded into a desired shape by any method.

[0050] Examples of methods for processing the resin composition include inflation molding, extrusion molding, injection molding, foam injection molding, injection compression molding, blow molding, press molding, calendar molding, vacuum molding, etc. The shape and use of molded products obtained from the resin composition are not particularly limited, and examples include films, sheets, containers (food containers, etc.), daily necessities, automobile parts, electrical and electronic parts, various consumables, etc.

[0051] The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

[0052] [Materials] The following components were used in each of the examples and comparative examples.

[0053] (Inorganic powder) GCC (calcium bicarbonate powder (surface untreated) manufactured by Bihoku Funka Kogyo Co., Ltd., average particle size: 2.2 μm, Mn content: <0.001% by mass, Fe content: 0.005% by mass) CCU1 (calcium carbonate powder made from steel slag, average particle size: 3.5 μm, Mn content: 0.1% by mass, Fe content: 0.5% by mass) CCU2 (calcium carbonate powder made from carbide slag, average particle size: 4.0 μm, Mn content: 0.005% by mass, Fe content: 0.1% by mass)

[0054] (Thermoplastic resin) PP1 (homopolypropylene, manufactured by Prime Polymer, E111G) PP2 (recycled polypropylene)

[0055] (Metal deactivators) CDA-1 (3-(N-salicyloyl)amino-1,2,4-triazole, manufactured by ADEKA Corporation, Adeka Stab CDA-1) CDA-6S (N'1,N'12-bis(2-hydroxybenzoyl)dodecane dihydrazide, manufactured by ADEKA Corporation, Adeka Stab CDA-6S) CDA-10 (N,N'-bis(salicyl)hydrazine, manufactured by ADEKA Corporation, Adeka Stab CDA-10) ZS-27 (melamine, manufactured by ADEKA Corporation, Adeka Stab ZS-27) ZS-90 (manufactured by ADEKA Corporation, Adeka Stab ZS-90) ZS-91 (manufactured by ADEKA Corporation, Adeka Stab ZS-91) MD1024 (N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, manufactured by BASF, Irganox MD1024)

[0056] (Others) Lubricant (stearic acid, manufactured by Kao Corporation) Antistatic agent (lithium salt, manufactured by Marubishi Yuka Kogyo Co., Ltd.) Antioxidant 1 (phenol-based antioxidant, manufactured by ADEKA Corporation) Antioxidant 2 (phosphite-based antioxidant, manufactured by ADEKA Corporation)

[0057] [Production of Resin Compositions and Molded Articles of Reference Examples 1 and 2, Comparative Examples 1 and 2, and Examples 1 to 13] Calcium carbonate powder, thermoplastic resin, metal deactivator, and other components were fed into a Parker HK-25D co-rotating twin-screw kneading extruder (φ25 mm, L / D=41) in the composition ratios shown in Table 1 and strand-extruded at a cylinder temperature of 230°C. The extruded pellets were then cooled and cut into pellets. The pellets were fed into a Toyo Seiki Seisaku-sho T-die extrusion molding machine (φ20 mm, L / D=25) and extruded at 240°C to obtain sheets. Sheets were produced with a draw ratio of 1x (unstretched), 2x, 3x, and 4x in the take-up direction. The stretching conditions were a casting temperature of 70°C and a stretching temperature of 100°C.

[0058] [Production of Resin Compositions and Molded Articles of Examples 14 to 19] The pellets produced in Examples 8 to 13 were used as masterbatches, and 80 parts by mass of these pellets were mixed with 20 parts by mass of a thermoplastic resin (PP1). The mixture was placed in a T-die extrusion molding machine (φ20 mm, L / D=25) manufactured by Toyo Seiki Seisaku-sho, and extruded at 240°C to obtain a sheet. Sheets were produced with a draw ratio of 1x (no stretching), 2x, 3x, and 4x in the take-up direction. The stretching conditions were a casting temperature of 70°C and a stretching temperature of 100°C.

[0059] [Evaluation] The elongation, tensile properties, stretchability, and tensile properties of stretched sheets of the sheets produced from each of the above-mentioned resin compositions were evaluated by the following methods.

[0060] Measurement of Elongation and Tensile Strength: Dumbbell-shaped test pieces were prepared from the sheets stretched at 1x (unstretched) in the above Examples, Comparative Examples, and Reference Examples in accordance with JIS K7161-2:2014. The elongation at break and tensile strength of the test pieces were measured in accordance with JIS K7161-2:2014 under conditions of 23°C and 50% RH using an Autograph AG-100kNXplus (manufactured by Shimadzu Corporation). The test speed was 50 mm / min. The results are shown in Tables 1 and 2.

[0061] Stretchability Based on the appearance of the stretched sheets produced in the above Examples, Comparative Examples, and Reference Examples, the stretchability of each resin composition was evaluated according to the following criteria. △ and above are in the range where there are no problems in practical use. The results are shown in Tables 1 and 2. ○: No unevenness in stretching, and variations in thickness and density are within 5% △: No unevenness in stretching, and variations in thickness and density are within 10% ×: Unevenness in stretching, or film breakage during stretching, or variations in thickness and density exceed 10%

[0062] Measurement of elongation and tensile strength of stretched sheets: Dumbbell-shaped test pieces were prepared from the sheets stretched 3 times in the above Examples, Comparative Examples, and Reference Examples in accordance with JIS K7161-2:2014. The elongation and tensile strength were measured in the same manner as above. The results are shown in Tables 1 and 2.

[0063]

[0064]

[0065] [Discussion] As shown in Tables 1 and 2 above, when the inorganic powder contained manganese and iron elements but no metal deactivator (Comparative Examples 1 and 2), the elongation and tensile properties were lower than when the inorganic powder contained almost no manganese or iron elements (Reference Examples 1 and 2).

[0066] In contrast, by adding 0.01% by mass or more and 1.00% by mass or less of a metal deactivator to the total amount of the resin composition, the elongation and tensile properties of the resin composition were significantly improved (Examples 1 to 19). In particular, when ZS-27 (melamine) was added as a metal deactivator, the resin composition had even better processability than when the inorganic powder contained almost no manganese or iron elements (Reference Examples 1 and 2) (e.g., Examples 4, 10 to 13, and 16 to 19).

[0067] This application claims priority from Japanese Patent Application No. 2023-217944, filed December 25, 2023, the entire contents of which are incorporated herein by reference.

[0068] The resin composition of the present invention provides a resin composition having high elongation and tensile strength and excellent processability, despite the inclusion of inorganic powders containing manganese and iron, and a molded article containing the resin composition. Therefore, inorganic powders made from steel slag, carbide slag, etc. can be used, and the resin composition is useful in the production of various industrial products.

Claims

1. A resin composition comprising a thermoplastic resin containing a polyolefin resin, an inorganic powder, and a metal deactivator, wherein the content of the inorganic powder is 50% by mass or more and 90% by mass or less, the amount of manganese element in the inorganic powder is 0.001% by mass or more and 0.500% by mass or less, and the amount of iron element in the inorganic powder is 0.01% by mass or more and 1.00% by mass or less, and the content of the metal deactivator is 0.2% by mass or more and 1.0% by mass or less.

2. The resin composition according to claim 1, wherein the thermoplastic resin contains a polypropylene resin and / or a polyethylene resin.

3. The resin composition according to claim 1, wherein the inorganic powder is calcium carbonate powder.

4. The resin composition according to claim 3, wherein the calcium carbonate powder is calcium carbonate powder made from steel slag and / or carbide slag as raw materials.

5. The resin composition according to claim 4, wherein the average particle diameter of the calcium carbonate powder measured by the air permeability method according to JIS M-8511 is 0.7 μm or more and 10.0 μm or less.

6. The resin composition according to claim 1, wherein the metal deactivator contains one or more compounds selected from the group consisting of melamine, 3-salicyloamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecanedihydrazide, 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine, N,N'-diphenyloxamide, N-salicyloyl-N'-salicyloylhydrazine, N,N'-bis(salicyloyl)hydrazine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, bis(benzylidene)oxalyldihydrazide, oxanilide, isophthaloyldihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyldihydrazide, N,N'-bis(salicyloyl)oxalyldihydrazide, and N,N'-bis(salicyloyl)thiopropionyl dihydrazide.

7. The resin composition according to claim 6, wherein the metal deactivator contains one or more compounds selected from the group consisting of melamine, 3-salicyloylamino-1,2,4-triazole, N'1,N'12-bis(2-hydroxybenzoyl)dodecanedihydrazide, and 1,2-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]hydrazine.

8. The resin composition according to claim 7, wherein the metal deactivator is melamine.

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

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