Antistatic polyolefin resin composition

Abstract

To provide a polyolefin resin composition excellent in antistatic properties and production stability.SOLUTION: The ingredient (C) is at least one selected from the group consisting of polyoxyalkylene alkylamines having an average number of moles of (C1) alkylene oxides added of 3 or more, (C2) polyoxyalkylene alkyl ethers, and (C3) polyalkylene glycols. A content of the component (B) is 0.3 to 10.0% by mass, a content of the component (C) is 0.01 to 0.5% by mass, and a mass ratio of the content of the component (B) to the content of the component (C) [(B) / (C)] is 70 / 30 to 99 / 1.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyolefin resin composition having excellent antistatic properties. [Background technology]

[0002] Conventionally, polyolefin resins are hydrophobic and therefore highly electrostatically charged. Therefore, static electricity causes problems during the production and use of polyolefin resin films, such as hygiene issues due to the adhesion of dust and dirt caused by static electricity, and problems such as poor appearance. To solve these problems, antistatic agents are generally used in polyolefin resins. Methods for using antistatic agents are broadly divided into two: applying the agent to the surface of the polyolefin resin and kneading the agent into the resin. However, the former method requires more steps in the production of resin molded products and has problems with the durability of the antistatic effect, so the latter method is industrially mainstream.

[0003] Prior art examples of antistatic agents that are kneaded into polyolefin resins include an antistatic resin composition (Patent Document 1) obtained by blending a polypropylene resin with a glycerin fatty acid ester having a specific ester content and a mixture of an alkyldiethanolamine and a fatty acid monoester of alkyldiethanolamine; a polyolefin resin composition containing a diglycerin fatty acid ester and an alkyldiethanolamide, wherein the glycerin fatty acid ester content in the composition is 100 ppm or less (Patent Document 2); and an antistatic agent for thermoplastic resins, which contains a glycerin fatty acid ester and a polyglycerin fatty acid ester as essential components and also contains a (poly)oxyethylene sorbitan fatty acid ester and / or an aliphatic amine ethylene oxide adduct, wherein the hydroxyl value and saponification value of the antistatic agent are in a specific ratio (Patent Document 3). However, these knead-in type antistatic agents have the problem of insufficient antistatic properties, and there is a demand for antistatic agents with higher performance.

[0004] To address this issue, an antistatic agent containing at least one of monoglycerin fatty acid ester, diglycerin fatty acid ester, and triglycerin fatty acid ester, and a hypophosphite has been disclosed (Patent Document 4). However, the hypophosphite causes eye discharge, which hinders long-term production.

[0005] In addition, several examples have been disclosed in which alkyl sulfonates and nonionic surfactants are used in combination with polyolefin resins (Patent Documents 5 to 9), but it has only been confirmed that these provide minimal antistatic properties. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-7854 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-303272 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-209613 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-110731 [Patent Document 5] Japanese Patent Application Publication No. 2018-193512 [Patent Document 6] Japanese Patent Application Laid-Open No. 2003-236910 [Patent Document 7] Japanese Patent Application Publication No. 6-15791 [Patent Document 8] Japanese Patent Application Laid-Open No. 2009-142997 [Patent Document 9] Japanese Patent Application Laid-Open No. 2006-297761 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a polyolefin resin composition having high antistatic properties. [Means for solving the problem]

[0008] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by combining an organic metal sulfonate with a specific nonionic surfactant in specific amounts and ratios. Based on this finding, the present inventors have conducted further research and have completed the present invention.

[0009] That is, the present invention comprises the following (1) and (2). (1) A polyolefin resin composition containing (A) a polyolefin resin, (B) an organic sulfonic acid metal salt, and (C) a nonionic surfactant, the component (C) is at least one selected from the group consisting of (C1) polyoxyalkylene alkylamines having an average addition mole number of alkylene oxide of 3 or more, (C2) polyoxyalkylene alkyl ethers, and (C3) polyalkylene glycols; The content of component (B) is 0.3 to 10.0 mass %, The content of component (C) is 0.01 to 0.5% by mass, The mass ratio of the contents of the (B) component and the (C) component [(B) / (C)] is 70 / 30 to 99 / 1. Polyolefin resin composition. (2) The surface specific electrical resistance of a molded product obtained by molding a polyolefin resin composition is 10 11 The polyolefin resin composition according to (1) above, wherein the viscosity is less than (Ω / □). [Effects of the Invention]

[0010] The polyolefin resin composition of the present invention has high antistatic properties. DETAILED DESCRIPTION OF THE INVENTION

[0011] [(A) Polyolefin resin] The polyolefin resin composition of the present invention contains a polyolefin resin as component (A). Examples of component (A) include homopolymers of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and 4-methyl-1-pentene; copolymers of the above α-olefins; copolymers of α-olefins and other monomers copolymerizable with the above α-olefins; and mixtures thereof. Examples of the above monomers copolymerizable with the α-olefins include vinyl acetate, maleic acid, vinyl alcohol, methacrylic acid, methyl methacrylate, and ethyl methacrylate.

[0012] Specific examples of component (A) include polyethylene resin and polypropylene resin (PP). Examples of polyethylene resin include linear low-density polyethylene resin (LLDPE), low-density polyethylene resin (LDPE), and high-density polyethylene resin (HDPE). Examples of polypropylene resin (PP) include homo-PP (h-PP), block PP (b-PP), and random PP (r-PP).

[0013] [(B) Metal organic sulfonate] The polyolefin resin composition of the present invention contains an organic sulfonic acid metal salt as component (B). Examples of component (B) include alkyl sulfonic acid metal salts such as sodium decyl sulfonate, sodium dodecyl sulfonate, lithium tetradecyl sulfonate, and potassium hexadecyl sulfonate, and alkyl benzene sulfonate metal salts such as sodium decyl sulfonate, sodium dodecyl sulfonate, lithium tetradecyl sulfonate, and potassium hexadecyl sulfonate. These components (B) may be used alone or in any combination of two or more, with those having 8 to 20 carbon atoms (preferably 12 to 18 carbon atoms) being preferred.

[0014] Examples of the component (B) that can be used in the present invention include commercially available TB-160 (trade name: sodium alkylsulfonate; manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), Sigma-Aldrich (trade name: sodium dodecylbenzenesulfonate; manufactured by Sigma-Aldrich), and Anstex HT-100 (trade name: sodium alkylsulfonate; manufactured by Toho Chemical Industry Co., Ltd.).

[0015] The content of component (B) in the polyolefin resin composition of the present invention is 0.3 to 10.0 mass%, more preferably 0.5 to 5.0 mass%, and even more preferably 0.8 to 4.0 mass%. If the content of component (B) is less than 0.3 mass%, the antistatic properties may be insufficient, which is undesirable, while if the content of component (B) exceeds 10.0 mass%, the processability of the polyolefin resin composition may deteriorate, causing large irregularities on the surface of the molded article, which may significantly impair the appearance, which is undesirable.

[0016] [(C) Nonionic surfactant] The polypropylene resin composition of the present invention contains, as component (C), one or more members selected from the group consisting of (C1) polyoxyalkylene alkylamines having an average addition mole number of alkylene oxide of 3 or more, (C2) polyoxyalkylene alkyl ethers, and (C3) polyalkylene glycols, in order to enhance antistatic properties that cannot be achieved by component (B) alone.

[0017] The polyoxyalkylene alkylamine (C1) used in the present invention, having an average number of added moles of alkylene oxide of 3 or more, includes a compound represented by the following general formula (1).

[0018] [ka]

[0019] In general formula (1), R 1 is an alkyl group, and A 1 O and A 2O represents an alkylene oxide group having 2 to 6 carbon atoms, and m and n represent A 1 O and A 2 The average number of moles of O added is 1 or more. The number of carbon atoms in the alkyl group is preferably 8 to 22, more preferably 12 to 22, and even more preferably 14 to 18. m+n (i.e., the average number of moles of alkylene oxide added to polyoxyalkylene alkylamine) is 3 or more, preferably 3 to 20, and more preferably 4 to 10. A 1 O and A 2 Specifically, O is, for example, EO (ethylene oxide group), PO (propylene oxide group), or BO (butylene oxide group), with EO and PO being preferred, and EO being more preferred.

[0020] (C1) Examples of polyoxyalkylene alkylamines having an average number of added moles of alkylene oxide of 3 or more include commercially produced and sold Liponol C / 15 (trade name: polyoxyethylene coconut alkylamine; average number of added moles of EO: 5; manufactured by Lion Specialty Chemicals), Liponol T / 15 (trade name: polyoxyethylene alkyl (C14-C18) amine; average number of added moles of EO: 5; manufactured by Lion Specialty Chemicals), and Liponol O / 15 (trade name: polyoxyethylene coconut alkylamine; average number of added moles of EO: 5; manufactured by Lion Specialty Chemicals), and these can be used in the present invention.

[0021] The polyoxyalkylene alkyl ether (C2) used in the present invention includes a compound represented by the following general formula (2).

[0022] [ka]

[0023] In general formula (2), R 1 is an alkyl group, and A 1 O represents an alkylene oxide group having 2 to 6 carbon atoms, and n represents A 1The number of carbon atoms in the alkyl group is preferably 4 to 22, more preferably 6 to 22, and still more preferably 8 to 18. n is preferably 1 to 50, and more preferably 2 to 20. A 1 Specifically, O is, for example, EO (ethylene oxide group), PO (propylene oxide group), or BO (butylene oxide group), with EO and PO being preferred, and EO being more preferred.

[0024] Examples of (C2) polyoxyalkylene alkyl ethers that can be used in the present invention include commercially produced and sold PEGNOL ST-7 (trade name: polyoxyethylene alkyl (C12-C14) ether; average number of moles of EO added: 7; manufactured by Toho Chemical Industry Co., Ltd.) and BRAWNON SR-705 (trade name: polyoxyethylene stearyl ether; average number of moles of EO added: 5; manufactured by Aoki Oil & Fat Industries Co., Ltd.).

[0025] The polyalkylene glycol (C3) used in the present invention includes polypropylene glycol polymerized with propylene oxide structural units, polyethylene glycol polymerized with ethylene oxide structural units, polybutylene glycol polymerized with butylene oxide structural units, and copolymers thereof, among which polyethylene glycol is preferred from the viewpoint of cost. The molecular weight of the polyalkylene glycol (C3) is not particularly limited, and the number average molecular weight (Mn) may be, for example, 100 to 20,000, 200 to 10,000, or 300 to 9,000.

[0026] Examples of (C3) polyalkylene glycols that are commercially manufactured and sold include PEG-300 (trade name: polyethylene glycol; number-average molecular weight: 300; Toho Chemical Industry Co., Ltd.), PEG-6000(C) (trade name: polyethylene glycol; number-average molecular weight: 8600; Toho Chemical Industry Co., Ltd.), and Alcox R-150 (trade name: Meisei Chemical Industry Co., Ltd.), and these can be used in the present invention.

[0027] The content of component (C) in the polyolefin resin composition of the present invention is 0.01 to 0.5 mass%, preferably 0.05 to 0.5 mass%, and more preferably 0.08 to 0.4 mass%. If the content of component (C) is less than 0.01 mass%, the antistatic properties may not be exhibited stably, which is undesirable, while if the content of component (C) exceeds 0.5 mass%, the antistatic properties may be inhibited, which is undesirable.

[0028] The mass ratio of the contents of the (B) component to the (C) component in the polyolefin resin composition of the present invention [(B) / (C)] is 70 / 30 to 99 / 1, preferably 70 / 30 to 97 / 3, and more preferably 85 / 15 to 95 / 5. If the proportion of the (B) component is higher than the above range, it is not preferable because the antistatic properties may not be uniform, and if the proportion of the (B) component is lower than the above range, it is not preferable because the antistatic properties may be insufficient.

[0029] The polypropylene resin composition of the present invention may contain various additives used in this field within the scope of not impairing the effects of the present invention. Examples of such additives include a foaming agent, a heat stabilizer, an antioxidant, a filler, a colorant, an anti-fogging agent, a neutralizing agent, a weather resistance agent, an ultraviolet absorber, a flame retardant, an anti-blocking agent, and an impact resistance improver.

[0030] In producing the polyolefin resin composition of the present invention, a masterbatch containing a high concentration of component (B) and / or component (C) in component (A) may be prepared in advance. The content of component (B) and / or component (C) in the masterbatch is not particularly limited, but is preferably 1 to 50 mass %, more preferably 5 to 20 mass %. The masterbatch form is preferred because it improves workability when producing the polyolefin resin composition.

[0031] The method for producing the masterbatch is not particularly limited as long as the component (A) and the component (B) and / or the component (C) are uniformly mixed. For example, the masterbatch can be produced by melt-kneading the raw materials while heating them using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, or the like.

[0032] The polypropylene resin composition of the present invention can be obtained by heating and kneading the components (A) to (C) (including the masterbatch) using a known kneader.

[0033] Examples of kneading machines that can be used include single-screw extruders, twin-screw extruders, Banbury mixers, kneaders, etc. Among these, twin-screw extruders are preferred in terms of productivity, kneading power, etc.

[0034] The heating temperature during kneading may be within a range that does not cause excessive deterioration of component (A) or the other components added, and specifically, for example, is in the range of 120 to 230° C. The heating and kneading time varies depending on the kneader used, heating conditions, etc., but, for example, when a twin-screw extruder is used as the kneader, the time is preferably 30 seconds to 10 minutes, more preferably 1 to 5 minutes.

[0035] The polyolefin resin composition of the present invention can be used as a molded product (including a sheet or a film) of any shape by a known molding method such as extrusion molding, injection molding, press molding, vacuum molding, or foam molding. The composition may also be kneaded in an extruder or the like before molding.

[0036] In the polyolefin resin composition of the present invention, a molded article obtained by molding the resin composition has a surface specific electrical resistance of 10 or more when measured under the condition of an applied voltage of 500 V using a Super Insulation Meter SM-8220 (manufactured by Toa DKK Co., Ltd.). 11 It is preferable that the resistance is less than (Ω / □).

[0037] Examples of uses for the molded articles include packaging materials, stationery, containers, plastic cardboard, clear cases, blister packs, automobile interior parts, and home appliances.

[0038] The present invention will be described below with reference to examples, which are merely illustrative of the present invention and are not intended to limit the present invention. [Example]

[0039] <Masterbatch production> (1) Raw materials [(A) Polyolefin resin] A-1: Polyethylene resin (product name: Novatec LD LD400; LDPE; manufactured by Japan Polyethylene Corporation) A-2: Polypropylene resin (product name: Prime Polypro J105G; homo PP; manufactured by Prime Polymer Co., Ltd.)

[0040] [(B) Metal organic sulfonate] B-1: Sodium alkylsulfonate (trade name: TB-160; manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) B-2: Sodium dodecylbenzenesulfonate (Sigma-Aldrich)

[0041] [(C) Nonionic surfactant] C1-1: Polyoxyethylene palm alkylamine (trade name: Liponol C / 15; average EO addition mole number: 5; manufactured by Lion Specialty Chemicals) C1-2: Polyoxyethylene alkyl (C14 to C18) amine (trade name: Liponol T / 15; average EO addition mole number: 5; manufactured by Lion Specialty Chemicals) C2-1: Polyoxyethylene alkyl (C12-C14) ether (trade name: Pegnol ST-7; average EO addition mole number: 7; manufactured by Toho Chemical Industry Co., Ltd.) C3-1: Polyethylene glycol (trade name: PEG300; number average molecular weight 300; Toho Chemical Industry Co., Ltd.) C3-2: Polyethylene glycol (trade name: PEG6000(C); number average molecular weight: 8600; Toho Chemical Industry Co., Ltd.)

[0042] [(D) Other surfactants] D-1: Stearyldiethanolamine (trade name: Anstex SA-20; average EO addition mole number: 2; manufactured by Toho Chemical Industry Co., Ltd.)

[0043] (2) Masterbatch compounding Table 1 shows the formulations of masterbatches 1 to 10 prepared using the above raw materials.

[0044] [Table 1]

[0045] (3) Masterbatch manufacturing method Five times the amount of the raw materials listed in Table 1 was melt-kneaded using a twin-screw extruder (model: KZW15TW-45MG-NH(-700); manufactured by Technovel Co., Ltd.) under conditions of a barrel temperature of 200°C, a head temperature of 200°C, a screw rotation speed of 500 rpm, and an extrusion rate of 3.0 kg / hr. The strand-shaped extruded material was cut using a pelletizer to obtain pellet-shaped masterbatches 1 to 10.

[0046] <Production of polyolefin resin composition and molded article thereof> (1) Raw materials [(A) Polyolefin resin] A-1: Polyethylene resin (product name: Novatec LD LD400; LDPE; manufactured by Japan Polyethylene Corporation) A-2: Polypropylene resin (product name: Prime Polypro J105G; homo PP; manufactured by Prime Polymer Co., Ltd.)

[0047] [Other ingredients] Masterbatch 1 to 10

[0048] (2) Blending of polyolefin resin composition Tables 2 to 4 show the formulations of the polyolefin resin compositions (Examples 1 to 16 and Comparative Examples 1 to 6) prepared using the above raw materials.

[0049] [Table 2]

[0050] [Table 3]

[0051] [Table 4]

[0052] (3) Preparation of polyolefin resin composition Five times the amount of raw materials listed in Tables 2 to 4 were melt-kneaded using a twin-screw extruder (model: KZW15TW-45MG-NH(-700); manufactured by Technovel Co., Ltd.) under conditions of a barrel temperature of 200°C, a head temperature of 200°C, a screw rotation speed of 300 rpm, and an extrusion rate of 3.0 kg / hr. The extruded strands were cut using a pelletizer to produce pellet-shaped polyolefin resin compositions (Examples 1 to 16 and Comparative Examples 1 to 6). The compositions of the resulting polyolefin resin compositions and the mass ratios of the contents of components (B) and (C) [(B) / (C)] are shown in Tables 5 to 7.

[0053] [Table 5]

[0054] [Table 6]

[0055] [Table 7]

[0056] (4) Preparation of polyolefin resin composition molded articles In order to evaluate the obtained polyolefin resin compositions (Examples 1 to 16 and Comparative Examples 1 to 6), they were extruded at 180°C using a single-screw extruder-T die (model: Labo Plastomill 3S150; manufactured by Toyo Seiki Seisakusho, Ltd.) to produce 300 μm thick sheet-shaped polyolefin resin composition molded products (Prototypes 1 to 22).

[0057] <Evaluation of antistatic effect> The antistatic effect of the polyolefin resin composition molded articles (Prototypes 1 to 22) was evaluated by measuring the surface specific electrical resistivity (Ω / □) of the sheet surface the day after production. The measurement was carried out according to the following method, and the measured results were symbolized according to the following evaluation criteria. The results are shown in Table 8.

[0058] [Surface specific electrical resistance measurement conditions] Testing machine: Super Insulation Meter SM-8220 (manufactured by Toa DKK) Applied voltage: 500V Application time: 1 minute Temperature: 20℃ Humidity: 65%

[0059] [Evaluation criteria] Surface specific electrical resistance (Ω / □) is 10 10 Less than: ◎ Surface specific electrical resistance (Ω / □) is 10 10 Over 10 11 Less than:○ Surface specific electrical resistance (Ω / □) is 10 11 Over 10 12 Less than: △ Surface specific electrical resistance (Ω / □) is 10 12 Above: ×

[0060] [Table 8]

[0061] As is clear from the results shown in Table 8, the polyolefin resin composition molded articles (prototypes 1 to 16) obtained using the polyolefin resin compositions of the present invention (examples 1 to 16) had superior antistatic properties compared to the polyolefin resin composition molded articles (prototypes 17 to 22) obtained using the polyolefin resin compositions of the comparative examples (comparison examples 1 to 8).

Claims

1. A polyolefin resin composition containing (A) a polyolefin resin, (B) an organic sulfonic acid metal salt, and (C) a nonionic surfactant, the component (C) is at least one member selected from the group consisting of (C1) polyoxyalkylene alkylamines having an average addition mole number of alkylene oxide of 3 or more, (C2) polyoxyalkylene alkyl ethers, and (C3) polyalkylene glycols; The content of the (B) component is 0.3 to 10.0 mass %, The content of component (C) is 0.01 to 0.5% by mass, the mass ratio of the contents of the component (B) and the component (C) [(B) / (C)] is 70 / 30 to 99 / 1; Polyolefin resin composition.

2. The surface specific electrical resistance of the molded product obtained by molding the polyolefin resin composition is 10 １１ The polyolefin resin composition according to claim 1, wherein the modulus of elasticity is less than (Ω / □).

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