Resin composition, molded article, and method for producing resin composition

Abstract

To provide: a resin composition that contains a recycled resin and is excellent in dynamical properties; a molded article; and a method for producing the resin composition.SOLUTION: The resin composition includes a synthetic resin and a nucleus agent; and the synthetic resin includes a recycled resin.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition, a molded article, and a method for producing a resin composition, and more particularly to a resin composition which contains recycled resin and has excellent mechanical properties, a molded article, and a method for producing a resin composition. [Background technology]

[0002] In recent years, with the rise in environmental awareness, there has been a demand for material recycling of plastics. As a technology relating to material recycling, for example, Patent Document 1 below discloses a resin composition containing a virgin resin and a recycled resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2024-137636 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the resin composition proposed in the above Patent Document 1 has room for further improvement in terms of mechanical properties.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a resin composition which contains recycled resin and has excellent mechanical properties, a molded article made from the resin composition, and a method for producing the resin composition. [Means for solving the problem]

[0006] As a result of intensive research into solving the above problems, the present inventors discovered that the above problems could be solved by using a nucleating agent as an additive, and thus completed the present invention.

[0007] That is, the present invention is a resin composition comprising a synthetic resin and a nucleating agent, wherein the synthetic resin comprises a recycled resin.

[0008] The present invention also relates to a molded article obtained by molding the above-mentioned resin composition.

[0009] Furthermore, the present invention is a method for producing a resin composition, comprising a blending step of blending a synthetic resin and a nucleating agent, wherein the synthetic resin contains a recycled resin. Effect of the Invention

[0010] According to the present invention, it is possible to provide a resin composition which contains recycled resin and has excellent mechanical properties, a molded article made from the resin composition, and a method for producing the resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail.

[0012] <Resin composition> The resin composition of the present embodiment includes a synthetic resin and a nucleating agent. Here, the synthetic resin includes a recycled resin.

[0013] The resin composition of the present embodiment contains recycled resin and has excellent mechanical properties.

[0014] The synthetic resin may be a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin include crystalline resins such as polyolefin resins, polyamide resins, polyester resins, polyacetal resins, polylactic acid, and polyphenylene sulfide, polycarbonate resins, styrene resins, acrylic resins, urethane resins, halogen-containing resins, petroleum resins, coumarone resins, polyvinyl alcohol, polyvinyl acetate, and polyphenylene oxide, and non-crystalline resins and thermoplastic elastomers. Examples of the thermosetting resin include phenol resins, urea resins, melamine resins, epoxy resins, unsaturated polyester resins, alkyd resins, and synthetic rubber. The synthetic resin may be contained alone or in combination of two or more types. The synthetic resin may be a copolymer or a polymer alloy.

[0015] The synthetic resin is preferably a thermoplastic resin, more preferably a crystalline resin, and further preferably a polyolefin resin.

[0016] Examples of polyolefin resins include polyethylene resins such as low density polyethylene, linear low density polyethylene, high density polyethylene, crosslinked polyethylene, and ultra-high molecular weight polyethylene, polypropylene (PP) resins such as homopolypropylene, random copolymer polypropylene, block copolymer polypropylene, impact copolymer polypropylene, high impact copolymer polypropylene, and maleic anhydride modified polypropylene, α-olefin polymers such as polybutene-1, cycloolefin polymer, poly-3-methyl-1-butene, poly-3-methyl-1-pentene, and poly-4-methyl-1-pentene, and α-olefin copolymers such as ethylene-methyl methacrylate copolymer and ethylene-vinyl acetate copolymer. From the viewpoint of making the resin composition excellent in heat resistance, the polyolefin resin preferably contains at least one selected from the group consisting of polyethylene resins and polypropylene resins, and more preferably contains a polypropylene resin. The molecular weight, degree of polymerization, density, softening point, proportion of insoluble matter in a solvent, degree of stereoregularity, presence or absence of catalyst residue, types and blending ratios of raw monomers, type of catalyst used in polymerization (e.g., Ziegler catalyst, metallocene catalyst, etc.), etc. of the polyolefin resin are not particularly limited and are selected appropriately.

[0017] In the resin composition of the present embodiment, the synthetic resin may contain an elastomer. In this case, the resin composition has excellent impact resistance. Here, examples of the elastomer include synthetic rubbers such as isoprene rubber, butadiene rubber, acrylonitrile-butadiene copolymer rubber, styrene-butadiene copolymer rubber, fluororubber, and silicone rubber, and thermoplastic elastomers such as polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. Among these, thermoplastic elastomers are preferred from the viewpoint of improving the processability of the resin composition and reducing the weight of molded products obtained by molding the resin composition. Furthermore, among the thermoplastic elastomers, polyolefin-based thermoplastic elastomers are particularly preferred. In the resin composition of the present embodiment, when the synthetic resin contains an elastomer, the content of the elastomer can be, for example, 5 to 50% by mass of the entire synthetic resin, preferably 10 to 30% by mass, and more preferably 15 to 25% by mass.

[0018] As described above, in the resin composition of the present embodiment, the synthetic resin includes a recycled resin.

[0019] The recycled resin is a resin obtained by crushing a molded product of a synthetic resin for the purpose of reuse. Examples of the recycled resin include post-consumer recycled (PCR) resin, post-industrial recycled (PIR) resin, and in-process crushed recycled (regrind) resin. In the resin composition of the present embodiment, the recycled resin preferably includes at least one selected from the group consisting of PCR high-density polyethylene resin, PIR high-density polyethylene resin, regrind high-density polyethylene resin, PCR linear low-density polyethylene resin, PIR linear low-density polyethylene resin, regrind linear low-density polyethylene resin, PCR low-density polyethylene resin, PIR low-density polyethylene resin, regrind low-density polyethylene resin, PCR polypropylene resin, PIR polypropylene resin, and regrind polypropylene resin, more preferably includes at least one selected from the group consisting of PCR high-density polyethylene resin, PIR high-density polyethylene resin, regrind high-density polyethylene resin, PCR polypropylene resin, PIR polypropylene resin, and regrind polypropylene resin, and even more preferably includes at least one selected from the group consisting of PCR high-density polyethylene resin, PIR high-density polyethylene resin, PCR polypropylene resin, and PIR polypropylene resin.

[0020] In the resin composition of the present embodiment, the content of the recycled resin can be, for example, 5% by mass or more of the total synthetic resins, and is preferably 5 to 100% by mass, more preferably 10 to 90% by mass, and even more preferably 20 to 80% by mass of the total synthetic resins.

[0021] As described above, the resin composition of the present embodiment contains a nucleating agent. Examples of the nucleating agent include compounds known to promote the crystallization of synthetic resins. Specific examples of the nucleating agent include sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, lithium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, dihydroxyaluminum 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, and hydroxyaluminum. Metal salts of aromatic phosphates such as bis[2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate], metal salts of carboxylic acids such as sodium benzoate, aluminum 4-tert-butylbenzoate, sodium adipate, disodium bicyclo[2.2.1]heptane-2,3-dicarboxylate, and calcium cyclohexane-1,2-dicarboxylate, dibenzylidene sorbitol, bis(methylbenzylidene)sorbitol, bis(3,4-dimethylbenzylidene)sorbitol, and bis(p-ethylbenzyl) sorbitol. and polyol derivatives such as N,N',N"-tris[2-methylcyclohexyl]-1,2,3-propanetricarboxamide, N,N',N"-tricyclohexyl-1,3,5-benzenetricarboxamide, N,N'-dicyclohexylnaphthalenedicarboxamide, and 1,3,5-tri(dimethylisopropylamino)benzene. From the viewpoint of improving the mechanical properties of the resin composition of this embodiment, the nucleating agent preferably contains an aromatic phosphate metal salt, more preferably contains at least one selected from the group consisting of sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate and lithium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, and even more preferably contains sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate.

[0022] In the resin composition of the present embodiment, the content of the nucleating agent can be, for example, 0.001 to 10 parts by mass relative to 100 parts by mass of the synthetic resin. From the viewpoint of improving the mechanical properties of the resin composition and sufficiently suppressing the occurrence of blooming and migration of the nucleating agent, the content of the nucleating agent is preferably 0.005 to 5 parts by mass, more preferably 0.01 to 3 parts by mass, even more preferably 0.02 to 1 part by mass, and even more preferably 0.05 to 0.5 parts by mass relative to 100 parts by mass of the synthetic resin.

[0023] The resin composition of the present embodiment may further contain additives such as phenol-based antioxidants, phosphorus-based antioxidants, thioether-based antioxidants, hindered amine compounds, ultraviolet absorbers, fatty acid metal salts, lubricants, hydrotalcites, flame retardants, flame retardant assistants, fillers, antistatic agents, antifogging agents, fluorescent brighteners, pigments, dyes, etc. (hereinafter referred to as "other additives"). The content of the other additives in the resin composition of the present embodiment may be within a range that does not impair the effects of the resin composition of the present embodiment. <Method of producing resin composition>

[0024] The method for producing a resin composition according to the present embodiment includes a blending step of blending a synthetic resin and a nucleating agent. Here, the synthetic resin includes a recycled resin.

[0025] According to the method for producing a resin composition of the present embodiment, a resin composition containing recycled resin and having excellent mechanical properties can be produced.

[0026] The method of mixing each component in the compounding step is not particularly limited, and examples thereof include a method of premixing the synthetic resin, the nucleating agent, and, if necessary, the other additives using various mixers such as a tumbler mixer or an FM mixer, and then melt-kneading using a Banbury mixer, a roll mill, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, or the like. Here, the temperature of melt-kneading can be, for example, 200°C to 300°C. In addition, the resin composition may be produced by not premixing each component, or by premixing only a portion of the components, feeding the mixture to an extruder using a feeder, and melt-kneading the mixture. Furthermore, a master batch may be produced by premixing a portion of the components and feeding the mixture to an extruder to melt-knead the mixture, and then the master batch may be mixed with other components and melt-kneaded to produce a resin composition.

[0027] <Molded products> The molded article of the present embodiment is obtained by molding the above-mentioned resin composition.

[0028] The molded article of this embodiment contains recycled resin and has excellent mechanical properties.

[0029] The method for molding the resin composition is not particularly limited, and examples thereof include extrusion molding, calendar molding, injection molding, roll molding, compression molding, blow molding, and rotational molding.

[0030] Specific examples of the molded article of the present embodiment include optical parts, machine parts, electric and electronic parts, automobile parts, resin glass, and building materials. More specific examples include office and office equipment such as printers, personal computers, word processors, keyboards, PDAs (personal digital assistants), telephones, copiers, facsimiles, ECRs (electronic cash registers), calculators, electronic organizers, cards, holders, and stationery; home appliances such as washing machines, refrigerators, vacuum cleaners, microwave ovens, lighting equipment, game consoles, and irons; AV equipment such as TVs, VTRs, video cameras, radio cassette players, tape recorders, minidisks, CD players, speakers, and liquid crystal displays; electrical and electronic parts and communication equipment such as connectors, relays, capacitors, switches, printed circuit boards, coil bobbins, semiconductor encapsulation materials, LED encapsulation materials, electric wires, cables, transformers, deflection yokes, distribution boards, and clocks; optical disks, CD disks, DVD disks, and other electrical and electronic parts and communication equipment. Examples of the materials used in automobiles, vehicles, ships, aircraft, buildings, housing and construction materials, civil engineering materials, clothing, curtains, sheets, plywood, synthetic fiber boards, rugs, entrance mats, sheets, buckets, hoses, containers, glasses, bags, cases, goggles, skis, rackets, tents, musical instruments and other daily necessities and sporting goods include:

[0031] Further embodiments of the present invention include, for example: [1] A synthetic resin and a nucleating agent are included, Synthetic resins include recycled resins, Resin composition. [2] The resin composition according to [1], wherein the synthetic resin is a polyolefin-based resin. [3] The resin composition according to [1] or [2], wherein the content of the recycled resin is 5% by mass or more of the total synthetic resins. [4] A molded article obtained by molding the resin composition according to any one of [1] to [3]. [5] The method includes a blending step of blending a synthetic resin and a nucleating agent, Synthetic resins include recycled resins, A method for producing a resin composition. [6] The method for producing a resin composition according to [5], wherein the synthetic resin is a polyolefin-based resin. [7] The method for producing a resin composition according to [5] or [6], wherein the content of the recycled resin is 5 mass% or more of the total synthetic resins. EXAMPLES

[0032] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0033] The synthetic resins and nucleating agents used in this example are as follows: [Synthetic resin] Recycled resin-1: PCR polypropylene resin, manufactured by Interzero, product name "Recythen PP" Recycled resin-2: PIR polypropylene resin, manufactured by Takaroku Shoji Co., Ltd., crushed automobile bumpers Recycled resin-3: PCR polypropylene resin, manufactured by Takaroku Shoji Co., Ltd., product name "PP-MER-BK" Recycled resin-4: PCR polypropylene resin, manufactured by Ishizuka Chemical Industry Co., Ltd., product name "PP R black" Recycled resin-5: PCR high-density polyethylene resin, manufactured by Ishizuka Chemical Industry Co., Ltd., product name "PE Hard R Black AP" Virgin resin-1: Virgin polypropylene resin, manufactured by Japan Polypropylene Corporation, product name "Novatec PP MA3" [Nucleating agent] Nucleating agent-1: ADEKA Corporation, product name "ADEKA STAB NA-11" Nucleating agent-2: ADEKA Corporation, product name "ADEKA STAB NA-27" Nucleating agent-3: ADEKA Corporation, product name "ADEKA STAB NA-25" Nucleating agent-4: ADEKA Corporation, product name "ADEKA STAB NA-18" Nucleating agent-5: ADEKA Corporation, product name "ADEKA STAB NA-902" Nucleating agent-6: ADEKA Corporation, product name "ADEKA STAB NA-901" Nucleating agent-7: ADEKA Corporation, product name "ADEKA STAB NA-960" Nucleating agent-8: ADEKA Corporation, product name "ADEKA STAB NA-908" Nucleating agent-9: ADEKA Corporation, product name "ADEKA STAB NA-908HT" Nucleating agent-10: ADEKA Corporation, product name "ADEKA STAB NA-912" Nucleating agent-11: ADEKA Corporation, product name "ADEKA STAB NA-71" Nucleating agent-12: ADEKA Corporation, product name "ADEKA STAB NA-21"

[0034] (Examples 1 to 1200) The synthetic resins and nucleating agents shown in Tables 1 to 120 were mixed in the amounts shown in Tables 1 to 120, 0.05 parts by mass of a phenol-based antioxidant (tetrakis[methylene-3-(3',5'-tert-butyl-4'-hydroxyphenyl)propionate]methane), and 0.1 parts by mass of a phosphorus-based antioxidant (tris(2,4-di-tert-butylphenyl)phosphite), and then mixed for 1 minute at a rotation speed of 1000 rpm using an FM mixer (FM200 manufactured by Mitsui Mining Co., Ltd.). The resulting mixture was melt-kneaded using a twin-screw extruder (TEX-28V manufactured by Japan Steel Works, Ltd.) under processing conditions of a resin temperature of 230°C and a screw speed of 150 rpm, and then granulated to obtain a pellet-shaped resin composition. In Tables 1 to 120, the unit of the amount is parts by mass.

[0035] <Characteristics evaluation> The resin compositions of Examples 1 to 1200 were dried at 80°C for 8 hours, and then injection molded using an injection molding machine (EC-220 manufactured by Toshiba Machine Co., Ltd.) under conditions of a resin temperature of 230°C and a mold temperature of 40°C to prepare bending test pieces of 80mm x 10mm x 4mm. The test pieces were left to stand in a thermostatic chamber at a temperature of 23°C and a humidity of 50% for 48 hours, and then removed from the thermostatic chamber, and the bending modulus (MPa) of the test pieces was measured using a bending tester (AG-IS manufactured by Shimadzu Corporation) in accordance with ISO178. Here, as a control sample, a bending test piece was prepared under the same conditions as for each of the examples, except that no nucleating agent was blended, and the bending modulus (MPa) was measured under the same conditions. As a result, it was revealed that the resin compositions of Examples 1 to 1200 had a larger bending modulus value than the respective control samples, and had excellent mechanical properties. Therefore, in Tables 1 to 120, the mechanical properties are also marked with "O."

[0036] [Table 1]

[0037] [Table 2]

[0038] [Table 3]

[0039] [Table 4]

[0040] [Table 5]

[0041] [Table 6]

[0042]

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[0054]

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[0055]

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[0056]

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[0057]

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[0059]

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[0060]

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[0062]

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[0064]

Table 29

[0065]

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[0066]

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[0070]

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[0090]

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[0114]

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[0115]

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[0119]

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[0120]

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[0121]

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[0122]

Table 87

[0123]

Table 88

[0124]

Table 89

[0125]

Table 90

[0126]

Table 91

[0127]

Table 92

[0128]

Table 93

[0129]

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[0130]

Table 95

[0131]

Table 96

[0132]

Table 97

[0133]

Table 98

[0134]

Table 99

[0135]

Table 100

[0136]

Table 101

[0137]

Table 102

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Table 103

[0139]

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[0140]

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[0144]

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[0145]

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[0148]

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[0149]

Table 114

[0150]

Table 115

[0151]

Table 116

[0152]

Table 117

[0153]

Table 118

[0154]

Table 119

[0155]

Table 120

[0156] From the above, it was confirmed that the resin composition of the present invention contains recycled resin and has excellent mechanical properties.

Claims

1. A synthetic resin and a nucleating agent are included, The synthetic resin includes recycled resin. Resin composition.

2. The resin composition according to claim 1 , wherein the synthetic resin is a polyolefin resin.

3. The resin composition according to claim 1 , wherein the content of the recycled resin is 5% by mass or more of the total synthetic resin.

4. A molded article obtained by molding the resin composition according to any one of claims 1 to 3.

5. The method includes a blending step of blending a synthetic resin and a nucleating agent, The synthetic resin includes recycled resin. A method for producing a resin composition.

6. The method for producing a resin composition according to claim 5 , wherein the synthetic resin is a polyolefin-based resin.

7. The method for producing a resin composition according to claim 5 , wherein the content of the recycled resin is 5% by mass or more of the total synthetic resins.

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