Antistatic masterbatch, antistatic resin composition, and antistatic resin molded article

Abstract

To provide an antistatic masterbatch which, even when a polypropylene resin or a low-density polyethylene resin is used as a diluent resin, takes a short time to develop an effective antistatic effect and can produce a resin composition and a resin molded article excellent in antistatic properties.SOLUTION: An antistatic masterbatch comprising at least one base resin selected from the group consisting of a homopolypropylene resin, an ethylene-propylene random copolymer, and a low-density polyethylene resin, a donor-acceptor type antistatic agent, and a bleed effect agent, wherein the bleed effect agent is at least one selected from the group consisting of a long-chain aliphatic alcohol, a long-chain aliphatic ester, and a surfactant, the content of the antistatic agent is 5 to 25% by mass, the content of the bleed effect agent is 0.5 to 15% by mass, and the amount of the bleed effect agent is 0.1 to 1 part by mass with respect to 1 part by mass of the antistatic agent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antistatic masterbatch, an antistatic resin composition, and an antistatic resin molded article. [Background technology]

[0002] Because resins such as plastics have high electrical insulation properties, molded articles made of resin (resin molded articles) tend to become charged with static electricity, which can easily cause problems such as equipment failure and fire. To avoid such problems, resin compositions containing surfactant-type antistatic agents (Patent Document 1), polymer-type antistatic agents (Patent Document 2), and donor-acceptor-type antistatic agents (Patent Document 3) have been proposed, as well as various molded articles produced using such compositions.

[0003] Surfactant-type antistatic agents are known to exhibit antistatic effects with the addition of small amounts, but the effect is known to deactivate relatively quickly. Furthermore, polymer-type antistatic agents are known to be prone to damaging the physical properties of the resin itself, since they do not exhibit antistatic effects unless kneaded into the resin at high concentrations. In contrast, donor-acceptor-type antistatic agents exhibit semi-permanent antistatic effects with the addition of small amounts, making it possible to manufacture a variety of resin molded products that exhibit good antistatic effects over long periods of time without damaging the physical properties of the resin itself. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-280841 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-256778 [Patent Document 3] Japanese Patent Application Publication No. 2023-32969 Summary of the Invention [Problem to be solved by the invention]

[0005] However, donor-acceptor antistatic agents are unlikely to exhibit effective antistatic effects unless they migrate to the surface of resin compositions or molded resin articles. For this reason, when a masterbatch containing a high concentration of donor-acceptor antistatic agent is diluted with a diluent resin to produce a resin composition or molded article, it can take a considerable amount of time for the antistatic effect to appear, depending on the type of resin. Specifically, it was found that when polypropylene resin or low-density polyethylene resin is used, it takes a long time for the antistatic effect to appear.

[0006] The present invention has been made in view of the problems associated with the conventional techniques, and an object of the present invention is to provide an antistatic masterbatch which, even when a polypropylene resin or a low-density polyethylene resin is used as a diluent resin, can produce an effective antistatic effect in a short time and which can produce a resin composition or a resin molded article having excellent antistatic properties.

[0007] Another object of the present invention is to provide an antistatic resin composition and an antistatic resin molded article which are obtained by using the above-mentioned antistatic masterbatch and which exhibit an effective antistatic effect in a short time and have excellent antistatic properties. [Means for solving the problem]

[0008] That is, according to the present invention, there is provided the following antistatic masterbatch. [1] An antistatic masterbatch comprising at least one base resin selected from the group consisting of homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin, a donor-acceptor type antistatic agent, and a bleed effect agent, wherein the bleed effect agent is at least one selected from the group consisting of long-chain aliphatic alcohols, long-chain aliphatic esters, and surfactants, the content of the antistatic agent is 5 to 25 mass%, the content of the bleed effect agent is 0.5 to 15 mass%, and the amount of the bleed effect agent per 1 mass part of the antistatic agent is 0.1 to 1 mass part. [2] The antistatic masterbatch according to [1], wherein the antistatic agent contains a compound represented by the following general formula (1):

[0009] TIFF2026023692000001.tif58170 (in the general formula (1), R1 and R2 each independently represent R7COOCH2- or HOCH2-, and at least one of them is R7COOCH2-; R3 and R4 each independently represent CH3-, C2H5-, HOCH2-, HOC2H4-, or HOCH2CH(CH3)-; R5 represents -C2H4- or -C3H6-; and R6 and R7 each independently represent an alkyl group having 11 to 21 carbon atoms).

[0010] [3] The antistatic masterbatch according to [1] or [2], wherein the bleeding effect agent is at least one selected from the group consisting of stearyl alcohol, glycerin fatty acid ester, and alcohol ethoxylate.

[0011] According to the present invention, there is also provided the following antistatic resin composition. [4] An antistatic resin composition comprising the antistatic masterbatch according to any one of [1] to [3] above and at least one diluent resin selected from the group consisting of homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin. [5] The surface resistivity (10 a1 and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. a2The antistatic resin composition according to item [4] above, wherein a 99% charge decay time α1 (seconds) of the antistatic resin composition containing 0.75% by mass of the antistatic agent and a multiplier a2 of the electrical resistance (Ω / sq) satisfy the relationship of the following formula (A1), and a 99% charge decay time α1 (seconds) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent satisfy the relationship of the following formula (A2). 0.6≦a2-a1≦3 (A1) 80≦α2-α1≦118 (A2) [6] The surface resistivity (10 b1 and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. b2 The antistatic resin composition according to item [4] above, wherein a 99% charge decay time β1 (seconds) of the antistatic resin composition containing 0.75% by mass of the antistatic agent and a multiplier b2 of the charge decay time β1 (seconds) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent satisfy the relationship of formula (B2) below: 0.3≦b2-b1≦1 (B1) 6≦β2-β1≦12 (B2) [7] The surface resistivity (10 c1 and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. c2The antistatic resin composition according to item [4] above, wherein a 99% charge decay time γ1 (seconds) of the antistatic resin composition containing 0.75% by mass of the antistatic agent and a multiplier c2 of the electric charge (Ω / sq) satisfy the relationship of the following formula (C1), and a 99% charge decay time γ2 (seconds) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent satisfy the relationship of the following formula (C2). 0.2≦c2-c1≦0.9 (C1) 5≦γ2-γ1≦10 (C2)

[0012] Furthermore, according to the present invention, there is provided the following antistatic resin molding. [8] An antistatic resin molded article which is a molded article of the antistatic resin composition according to any one of [4] to [7] above. [9] The antistatic resin molding according to [8], which is an automobile part, a building material part, a machine part, an electric or electronic part, a furniture or home appliance part, a container, a packaging material, or a film. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide an antistatic masterbatch which can produce a resin composition or a resin molded article having excellent antistatic properties in a short time even when a polypropylene resin or a low-density polyethylene resin is used as a diluent resin.

[0014] Furthermore, according to the present invention, it is possible to provide an antistatic resin composition and an antistatic resin molded article which are obtained by using the above-mentioned antistatic masterbatch and which exhibit an effective antistatic effect in a short time and have excellent antistatic properties. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Antistatic masterbatch> Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. One embodiment of the antistatic masterbatch of the present invention contains at least one base resin selected from the group consisting of homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin, a donor-acceptor type antistatic agent, and a bleed effect agent. Hereinafter, the antistatic masterbatch of this embodiment (hereinafter also simply referred to as "masterbatch") will be described in detail.

[0016] (base resin) The masterbatch of this embodiment contains at least one base resin selected from the group consisting of a homopolypropylene resin, an ethylene-propylene random copolymer, and a low-density polyethylene resin.

[0017] From the viewpoint of manufacturing such as kneading, the content of the base resin in the masterbatch is preferably 60 to 94.5 mass %, more preferably 70 to 90 mass %, based on the total mass of the masterbatch.

[0018] [Polypropylene resin] As the polypropylene resin, from the viewpoints of antistatic properties, processability, moldability, etc., homopolypropylene resins such as crystalline homopolypropylene, and ethylene-propylene random copolymers can be used.

[0019] Polypropylene resins can be classified according to their ethylene content. For example, a polypropylene resin having an ethylene content of 0 to 0.1% by mass is a crystalline homopolypropylene. A polypropylene resin having an ethylene content of more than 0.1% by mass and not more than 5% by mass is an ethylene-propylene random copolymer. The ethylene content of a polypropylene resin can be determined by infrared spectroscopy and 13 It can be measured by C-NMR measurement.

[0020] The MFR (melt flow rate) of the polypropylene resin, measured in accordance with the ISO 1133 test method (230°C, 21.2N), is preferably 0.1 g / 10 min to 80 g / 10 min, and preferably 0.4 g / 10 min to 60 g / 10 min. If the MFR of the polypropylene resin is less than 0.1 g / 10 min, the viscosity may be high, which may slightly reduce the dispersibility of antistatic agents and various additives. On the other hand, if the MFR of the polypropylene resin is more than 80 g / 10 min, the viscosity may be low, which may slightly reduce the dispersibility of antistatic agents and various additives. These polypropylene resins are commercially available from, for example, Japan Polypropylene Corporation, SunAllomer Corporation, and Prime Polymer Corporation.

[0021] [Low-density polyethylene resin] The density of low-density polyethylene resin is usually 0.91 to 0.94 g / cm 3 The low-density polyethylene resin may be either a metallocene-based linear low-density polyethylene or a high-pressure low-density polyethylene.

[0022] The density of metallocene-based linear low-density polyethylene is 0.91 to 0.94 g / cm 3 Preferably, the metallocene linear low-density polyethylene has an MFR of 2 to 16 g / 10 min. Examples of commercially available metallocene linear low-density polyethylene include Sumikathene E (manufactured by Sumitomo Chemical Co., Ltd.), Harmolex (manufactured by Japan Polyethylene Corporation), and Elite (manufactured by The Dow Chemical Company).

[0023] The density of high-pressure low-density polyethylene is 0.91 to 0.925 g / cm 3 Preferably, the MFR of the high-pressure low-density polyethylene is 1 to 10 g / 10 min. Examples of commercially available high-pressure low-density polyethylene include Novatec LD (manufactured by Japan Polyethylene Co., Ltd.), Suntec LD (manufactured by Asahi Kasei Corporation), Sumikathene (manufactured by Sumitomo Chemical Co., Ltd.), and Petrothene (manufactured by Tosoh Corporation).

[0024] (antistatic agent) Donor-acceptor antistatic agents are high-molecular-weight antistatic agents that contain a donor moiety, a basic organic nitrogen compound that eliminates negative charges, and an acceptor moiety, a semi-polar organic boron compound, that eliminates positive charges. When donor-acceptor antistatic agents are used, the charge generated by charge transfer transition is neutralized simultaneously with the generation of charge, resulting in an antistatic effect. On the other hand, low-molecular-weight antistatic agents typically bleed out onto the surface of resin compositions and molded products, reducing surface resistivity, but their effectiveness tends to be shortened due to being scraped off from the surface by friction.

[0025] Donor-acceptor type high molecular weight antistatic agents are less likely to bleed out onto the surface of resin compositions and molded articles, and their presence near the surface provides an antistatic effect. Therefore, the use of donor-acceptor type high molecular weight antistatic agents can reduce the surface resistivity of the resulting resin compositions and molded articles, and also has advantages in terms of charge decay rate, compared to the use of low molecular weight antistatic agents. Furthermore, the use of donor-acceptor type high molecular weight antistatic agents maintains the antistatic effect for a longer period of time and, due to their resistance to bleed-out, can better maintain the surface condition of resin compositions and molded articles. Other antistatic agents include ionic liquids. However, because ionic liquids are liquid at room temperature, their use as antistatic agents reduces moldability and the impact strength of the resulting resin compositions and molded articles. Furthermore, ionic liquids can solidify at certain temperatures, which can reduce the weather resistance of the resulting resin compositions and molded articles, limiting their applications.

[0026] The donor-acceptor type antistatic agent preferably contains a compound represented by the following formula (1): Furthermore, the donor-acceptor type antistatic agent is more preferably a compound represented by the following formula (1):

[0027] TIFF2026023692000002.tif58170 (in the general formula (1), R1 and R2 each independently represent R7COOCH2- or HOCH2-, and at least one of them is R7COOCH2-; R3 and R4 each independently represent CH3-, C2H5-, HOCH2-, HOC2H4-, or HOCH2CH(CH3)-; R5 represents -C2H4- or -C3H6-; and R6 and R7 each independently represent an alkyl group having 11 to 21 carbon atoms).

[0028] In general formula (1), it is preferable that both R1 and R2 are R7COOCH2-. It is preferable that R3 and R4 each independently represent CH3- or C2H5-, and more preferably both represent CH3-. Furthermore, it is preferable that R5 is -C3H6-. The number of carbon atoms in the alkyl groups represented by R6 and R7 each independently is preferably 12 to 20, and more preferably 14 to 18.

[0029] The content of the donor-acceptor antistatic agent in the masterbatch is 5 to 25 mass% based on the total mass of the masterbatch, and preferably 10 to 20 mass%. If the content of the antistatic agent is less than 5 mass%, the amount of antistatic agent present near the surface of the resulting resin composition or molded article will be insufficient, resulting in insufficient antistatic effect. On the other hand, if the content of the antistatic agent is more than 25 mass%, the excess antistatic agent will tend to bleed out onto the surface of the resin composition or molded article, making it difficult to form the masterbatch.

[0030] (bleed effect agent) The bleeding effect agent is a component that has high affinity with the antistatic agent dispersed in the base resin, but has low compatibility with the base resin. By using a bleeding curing agent with such properties, the antistatic agent can be migrated to the vicinity of the surface of the resin composition or molded article obtained without excessive bleeding out onto the surface of the resin composition or molded article, while maintaining the surface of the resin composition or molded article in good condition.

[0031] In the masterbatch of this embodiment, the respective contents of the antistatic agent and the bleed effect agent and their quantitative ratio were appropriately set in consideration of the crystallinity and polarity of the polypropylene resin and the low-density polyethylene resin. The bleed effect agent works both in a system in which the antistatic agent is relatively well dispersed in the resin and in a system in which the antistatic agent is difficult to disperse in the resin and tends to aggregate. The effect of the bleed curing agent is thought to be related to the polarity, crystallinity, and density of the resin. As mentioned above, it is effective when homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin are used as base resins or diluents. For example, it was confirmed that the bleed effect agent is effective when homopolypropylene resin and ethylene-propylene random copolymer, which are polar resins with different crystallinity, are used. Furthermore, it was confirmed that the bleed effect agent is effective only when low-density polyethylene resin is used with low-density polyethylene resin and high-density polyethylene resin, which are non-polar resins with different crystallinity.

[0032] The bleeding effect agent is at least one selected from the group consisting of long-chain aliphatic alcohols, long-chain aliphatic esters, and surfactants. The long-chain aliphatic alcohol preferably has 12 or more carbon atoms. Among these, stearyl alcohol, which has 18 carbon atoms, is preferred.

[0033] Examples of surfactants include nonionic surfactants, anionic surfactants, and cationic surfactants. Examples of nonionic surfactants include long-chain fatty acid esters, ethanolamines, and polyoxyethylene alkyl ethers. Examples of anionic surfactants include alkyl sulfonates. Examples of cationic surfactants include quaternary ammonium salts. Among these, it is preferable to use long-chain fatty acid esters and ethanolamines as surfactants.

[0034] Examples of long-chain fatty acid esters include glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, polyoxysorbitan fatty acid esters, etc. Among these, it is preferable to use glycerin fatty acid esters.

[0035] The content of the bleed effect agent in the masterbatch is 0.5 to 15 mass% and preferably 1 to 10 mass% based on the total mass of the masterbatch. If the content of the bleed effect agent is less than 0.5 mass%, the effect of migrating the antistatic agent to the surface of the molded article is reduced, resulting in insufficient antistatic effect. On the other hand, if the content of the bleed effect agent is more than 15 mass%, the effect of migrating the antistatic agent to the surface of the molded article is excessive, and excess antistatic agent is likely to bleed out onto the surface of the resin composition or the molded article.

[0036] In the masterbatch, the amount of the bleed effect agent per 1 part by mass of the antistatic agent is 0.1 to 1 part by mass, preferably 0.15 to 0.5 parts by mass. If the amount of the bleed effect agent per 1 part by mass of the antistatic agent is less than 0.1 part by mass, the antistatic agent will not migrate easily to the surface of the resin composition or molded article, making it impossible to shorten the time until the antistatic effect is achieved. On the other hand, if the amount of the bleed effect agent per 1 part by mass of the antistatic agent is more than 1 part by mass, the antistatic agent and the bleed effect agent will easily bleed out onto the surface of the resin composition or molded article.

[0037] (Other ingredients) The masterbatch may further contain other components in addition to the above-mentioned components, as necessary, such as a flame retardant aid, a filler for improving various properties such as mechanical properties, and other additives.

[0038] Examples of the flame retardant aid include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide. Examples of the filler include silica, talc, clay, mica, titanium oxide, glass beads, glass flakes, glass fiber, calcium carbonate, barium carbonate, calcium sulfate, barium sulfate, calcium silicate, potassium titanate, aluminum borate, magnesium borate, and carbon fiber. Examples of other additives include plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, curing agents, curing accelerators, antistatic agents, conductivity-imparting agents, mold release agents, lubricants, dyes, and pigments.

[0039] (Method of manufacturing antistatic masterbatch) The masterbatch of this embodiment can be produced by mixing and melt-kneading a base resin, a donor-acceptor antistatic agent, a bleed effect agent, and other components used as needed. Specific examples of melt-kneading methods include pre-mixing the components using various mixers such as a high-speed mixer, followed by melt-kneading using a kneading device such as a Banbury mixer, a roll, a plastograph, a single-screw extruder, a twin-screw extruder, or a kneader. From the standpoint of production efficiency, melt-kneading using an extruder is preferred, and melt-kneading using a twin-screw extruder is even more preferred. The components are melt-kneaded using an extruder, and the resulting kneaded mixture can be extruded into strands and then processed into pellets, flakes, or other shapes.

[0040] The temperature during melt-kneading may be, for example, 150 to 280°C, and can be appropriately set depending on the type of base resin used. When a polypropylene resin is used as the base resin, the temperature during melt-kneading is preferably 180 to 270°C, more preferably 190 to 230°C. When a low-density polyethylene resin is used as the base resin, the temperature during melt-kneading is preferably 160 to 250°C, more preferably 170 to 210°C. Since the masterbatch of this embodiment uses a donor-acceptor type antistatic agent, it is resistant to thermal decomposition even when melt-kneaded under such high-temperature conditions, and the generation of unpleasant odors can be avoided.

[0041] <Antistatic resin composition> The antistatic resin composition of this embodiment (hereinafter also referred to simply as "resin composition") contains the above-mentioned antistatic masterbatch and at least one diluent resin selected from the group consisting of homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin. By preparing a resin composition containing the diluent resin to which antistatic properties are to be imparted and the masterbatch, the dispersibility of the antistatic agent is improved and poor appearance can be prevented compared to when the components are kneaded without using the masterbatch.

[0042] The resin composition of this embodiment can be obtained by melt-kneading the components in the same manner as the masterbatch described above. The kneading apparatus that can be used and the temperature during melt-kneading are the same as those used in producing the masterbatch described above.

[0043] The resin composition is preferably in the form of pellets or flakes. Molded articles (antistatic molded articles) having a desired shape can be produced by molding the resin composition using various molding methods, such as extrusion molding, injection molding, calendar molding, film molding, sheet molding, blow molding, injection blow molding, inflation molding, and foam molding. In particular, the resin composition of this embodiment is suitable as a material for producing resin molded articles having a portion with a thickness of 100 μm or more.

[0044] (diluted resin) The diluent resin is a thermoplastic resin similar to the base resin used in the masterbatch. That is, the diluent resin is at least one thermoplastic resin selected from the group consisting of homopolypropylene resin, ethylene-propylene random copolymer, and low-density polyethylene resin. The diluent resin is preferably the same type of thermoplastic resin as the base resin used in the masterbatch because it has good compatibility with the masterbatch. The content of the masterbatch in the resin composition is preferably 1 to 20 mass %, more preferably 1 to 10 mass %, based on the total amount of the resin composition.

[0045] The content of the thermoplastic resin in the resin composition (the total content of the base resin and the diluted resin) is preferably 92% by mass or more and 99.945% by mass or less, based on the total mass of the resin composition. From the viewpoint of imparting antistatic properties to the diluted resin, the content of the antistatic agent in the resin composition is preferably 0.05% by mass or more and 5% by mass or less, based on the total mass of the resin composition, and more preferably 0.05% by mass or more and 2.5% by mass or less. The content of the bleed effect agent in the resin composition is preferably 0.005% by mass or more and 3% by mass or less, and more preferably 0.005% by mass or more and 1.5% by mass or less, based on the total mass of the resin composition.

[0046] (Surface resistivity) By using the masterbatch described above, antistatic properties can be easily imparted to the diluted resin, and the resin composition of this embodiment exhibiting the desired antistatic properties can be obtained. Specifically, when the base resin and the diluted resin are both homopolypropylene resins, the surface resistivity (10 a1 The surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the resin composition except that it does not contain a bleeding effect agent is a2 and a multiplier a2 of Ω / sq preferably satisfy the relationship of the following formula (A1). 0.6≦a2-a1≦3 (A1)

[0047] In addition, when the base resin and the diluent resin are both ethylene-propylene random copolymers, the surface resistivity (10 b1 The surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the resin composition except that it does not contain a bleeding effect agent is b2 and a multiplier b2 of Ω / sq preferably satisfy the relationship of the following formula (B1). 0.3≦b2-b1≦1 (B1)

[0048] Furthermore, when the base resin and the diluent resin are both low-density polyethylene resins, the surface resistivity (10 c1 The surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the resin composition except that it does not contain a bleeding effect agent is c2 and a multiplier c2 of Ω / sq preferably satisfy the relationship of the following formula (C1). 0.2≦c2-c1≦0.9 (C1)

[0049] (charge decay time) By using the masterbatch described above, the resin composition of this embodiment can be obtained with a short charge decay time and a reduced time until the antistatic effect is exhibited. Specifically, when the base resin and the diluent resin are both homopolypropylene resins, the 99% charge decay time α1 (seconds) of a resin composition containing 0.75 mass% of antistatic agent and the 99% charge decay time α2 (seconds) of a control resin composition having the same composition as the resin composition except that it does not contain a bleed effect agent preferably satisfy the relationship of the following formula (A2): 80≦α2-α1≦118 (A2)

[0050] Furthermore, when the base resin and the diluent resin are both ethylene-propylene random copolymers, the 99% charge decay time β1 (seconds) of a resin composition containing 0.75 mass% of an antistatic agent and the 99% charge decay time β2 (seconds) of a control resin composition having the same composition as the resin composition except that it does not contain a bleed effect agent preferably satisfy the relationship of the following formula (B2): 6≦β2-β1≦12 (B2)

[0051] Furthermore, when the base resin and the diluent resin are both low-density polyethylene resins, the 99% charge decay time γ1 (seconds) of a resin composition containing 0.75 mass% of an antistatic agent and the 99% charge decay time γ2 (seconds) of a control resin composition having the same composition as the resin composition except that it does not contain a bleed effect agent preferably satisfy the relationship of the following formula (C2): 5≦γ2-γ1≦10 (C2)

[0052] The resin composition of the present embodiment is useful as a resin material for producing various resin molded bodies (articles) that are excellent in design and charge decay, because components such as antistatic agents and bleeding effect agents are less likely to bleed out and the resin composition maintains a good, non-sticky surface condition.

[0053] (Anti-static resin molding) The antistatic resin molded article of this embodiment (hereinafter also referred to simply as "resin molded article" or "molded article") is a molded article of the above-described antistatic resin composition. Therefore, even though the resin molded article of this embodiment uses polypropylene resin or low-density polyethylene resin as a diluent resin, it has a short charge decay time, shortens the time until an effective antistatic effect is exhibited, and has excellent antistatic properties. Furthermore, because it contains a donor-acceptor type antistatic agent, it exhibits excellent antistatic effects over a long period of time. Therefore, the resin molded article of this embodiment is useful as automobile parts, building materials, machine parts, electrical and electronic parts, furniture and home appliance parts, containers, packaging materials, films, and the like. [Example]

[0054] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified.

[0055] <Preparing ingredients> The following materials were prepared:

[0056] (polypropylene resin) h-PP: Homopolypropylene resin, product name "Novatec PP-MA3", manufactured by Japan Polyethylene Co., Ltd., MFR 11g / 10min r-PP: Ethylene-propylene random copolymer, product name "Prime Polypro F219DA", manufactured by Prime Polymer Co., Ltd., MFR 8g / 10min

[0057] (Polyethylene resin) LDPE: Low-density polyethylene resin, product name "Suntech LD F2270", manufactured by Asahi Kasei Chemicals Corporation, density 0.92 g / cm 3 , MFR7g / 10min HDPE: High-density polyethylene resin, product name "Hi-Zex 5305E", manufactured by Prime Polymer Co., Ltd., density 0.95 g / cm 3 , MFR 0.79g / 10min

[0058] (antistatic agent) A donor-acceptor type antistatic agent (BN type charge transfer antistatic agent) represented by the following formula (2):

[0059] TIFF2026023692000003.tif59170

[0060] (bleed effect agent) A-1: Stearyl alcohol: Product name "Kalcol 8098", manufactured by Kao Chemical Co., Ltd. A-2: Glycerin fatty acid ester A: Product name "Dasper K200", manufactured by Miyoshi Oil & Fat Co., Ltd. A-3: Glycerin fatty acid ester B: Product name "Electrostripper TS-5", manufactured by Kao Chemical Co., Ltd.

[0061] <Masterbatch manufacturing> Example 1 A mixture was obtained by mixing 80 parts of h-PP, 15 parts of an antistatic agent, and 5 parts of a bleeding effect agent A-1. The mixture was melt-kneaded at 170 to 210°C for 3 minutes using a lab mixer (product name "R60H type", manufactured by Toyo Seiki Seisakusho, Ltd.) to obtain a masterbatch.

[0062] (Examples 2 to 10, Comparative Examples 1 to 9, Reference Examples 1 to 4) A masterbatch was obtained in the same manner as in Example 1, except that the types and amounts (units: parts) of each component shown in Tables 1-1 and 1-2 were used. In Comparative Example 7, the strands became liquid, and a masterbatch could not be obtained.

[0063] <Production of Resin Composition and Molded Article (Test Piece)> The masterbatch was mixed with the same type of base resin as used in the masterbatch so that the antistatic agent concentration was 0.75%, and then the mixture was melt-kneaded at 180-240°C using a single-screw extruder (product name "IPE-30", manufactured by CTE Corporation) to obtain a homogeneous resin composition.The resulting resin composition was injection-molded using an injection molding machine (product name "SANJECT3601", manufactured by Yamashiro Seiki Mfg. Co., Ltd.) at a cylinder temperature of 190-215°C and a mold temperature of 40°C to obtain injection-molded test pieces (45mm x 60mm x 2mm).

[0064] <Evaluation> (surface resistivity measurement) The surface resistivity of the obtained test piece was measured using a surface resistance meter (Worksurface Tester ST-4, manufactured by Simco Japan) under the conditions of an applied voltage of 100 V and a measurement time of 30 seconds. n The multiplier (n) of Ω / sq is shown in Tables 1-1 and 1-2. 13.5 Any value greater than "10 Ω / sq" is 13.5 Ω / sq", so "10 13.5"Ω / sq" was set as the upper limit of the surface resistivity. In addition, to confirm the effect obtained by using the bleeding effect agent, the values ​​of "a2-a1", "b2-b1", and "c2-c1" were calculated for the resin compositions obtained in Examples 1 to 3, 9, and 10. The results are shown in Table 2.

[0065] (Measurement of charge decay time) The resulting test specimens were conditioned for 24 hours (temperature 23±2°C, humidity 50±2% RH). A charge decay meter (product name "STATIC HONESTMETER H-0110," manufactured by Shishido Corporation) was used to apply a voltage of -10 kV for 30 seconds, after which the charge was measured at 120 seconds. After the voltage application was completed, the time required for the charge to decay to 1% or less of the applied voltage of -10 kV (99% charge decay) (99% charge decay time) was measured. Since all values ​​exceeding "120 seconds" were recorded as "120 seconds" with this charge decay meter, "120 seconds" was set as the upper limit for the 99% charge decay time. Furthermore, to confirm the effects of using a bleeding effect agent, the values ​​of "α2-α1," "β2-β1," and "γ2-γ1" were calculated for the resin compositions obtained in Examples 1 to 3, 9, and 10. The results are shown in Table 2.

[0066] (Bleed-out prevention) The prepared test pieces were observed and evaluated for bleed-out inhibition according to the following evaluation criteria, and the results are shown in Tables 1-1 and 1-2. ○: No poor appearance or stickiness was observed. △: Poor appearance and stickiness were observed in some areas. ×: Poor appearance and stickiness were observed throughout.

[0067] TIFF2026023692000004.tif126170

[0068] TIFF2026023692000005.tif103170

[0069] TIFF2026023692000006.tif86170

[0070] (Application example: film production) Using a 20 mm single-screw extruder equipped with a T-die, the resin composition obtained in Example 1 was extrusion molded at a processing temperature of 170 to 210°C to produce a film (test piece) with a thickness of approximately 50 μm. The film produced had properties equivalent to those of the test piece obtained by injection molding. [Industrial Applicability]

[0071] The antistatic masterbatch of the present invention is useful as a material for producing resin compositions and various molded articles having excellent antistatic properties.

Claims

1. The present invention relates to a coating composition comprising at least one base resin selected from the group consisting of a homopolypropylene resin, an ethylene-propylene random copolymer, and a low-density polyethylene resin, a donor-acceptor type antistatic agent, and a bleeding effect agent, the bleeding effect agent is at least one selected from the group consisting of a long-chain aliphatic alcohol, a long-chain aliphatic ester, and a surfactant; The content of the antistatic agent is 5 to 25% by mass, the content of the bleeding effect agent is 0.5 to 15% by mass, The antistatic masterbatch, wherein the amount of the bleeding effect agent relative to 1 part by mass of the antistatic agent is 0.1 to 1 part by mass.

2. 2. The antistatic masterbatch according to claim 1, wherein the antistatic agent comprises a compound represented by the following general formula (1): (In the general formula (1), R １ and R ２ are each independently R ７ COOCH ２ - or HOCH ２ - and at least one is R ７ COOCH ２ - and R ３ and R ４ are each independently CH ３ -, C ２ H ５ -, HOCH ２ -, HOC ２ H ４ - or HOCH ２ CH (CH ３ )-, R ５ is -C ２ H ４ -or-C ３ H ６ - indicates R ６ and R ７ each independently represents an alkyl group having 11 to 21 carbon atoms.

3. 2. The antistatic masterbatch according to claim 1, wherein the bleeding effect agent is at least one selected from the group consisting of stearyl alcohol, glycerin fatty acid ester, and alcohol ethoxylate.

4. The antistatic masterbatch according to any one of claims 1 to 3, and at least one diluent resin selected from the group consisting of a homopolypropylene resin, an ethylene-propylene random copolymer, and a low-density polyethylene resin.

5. the base resin and the diluent resin are both homopolypropylene resins, The surface resistivity (10 ａ１ and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ａ２ and a multiplier a2 of the constant Ω / sq satisfy the relationship of the following formula (A1), The 99% charge decay time α of the antistatic resin composition having an antistatic agent content of 0.75% by mass １ (seconds), and the 99% charge decay time α of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ２ The antistatic resin composition according to claim 4, wherein (seconds) satisfies the following formula (A2): 0.6≦a2-a1≦3...(A1) 80≦α ２ -α １ ≦118 ・・・(A2)

6. the base resin and the diluent resin are both ethylene-propylene random copolymers, The surface resistivity (10 ｂ１ and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ｂ２ and a multiplier b2 of the constant Ω / sq satisfy the relationship of the following formula (B1), The 99% charge decay time β of the antistatic resin composition having an antistatic agent content of 0.75% by mass １ (seconds), and the 99% charge decay time β of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ２ The antistatic resin composition according to claim 4, wherein (seconds) satisfies the following formula (B2): 0.3≦b2-b1≦1...(B1) 6≦β ２ -β １ ≦12 ・・・(B2)

7. the base resin and the diluent resin are both low-density polyethylene resins, The surface resistivity (10 ｃ１ and the surface resistivity (10 Ω / sq) of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ｃ２ and a multiplier c2 of the constant Ω / sq satisfy the relationship of the following formula (C1), The 99% charge decay time γ of the antistatic resin composition having an antistatic agent content of 0.75% by mass １ (seconds), and the 99% charge decay time γ of a control resin composition having the same composition as the antistatic resin composition except that it does not contain the bleeding effect agent. ２ The antistatic resin composition according to claim 4, wherein (seconds) satisfies the following formula (C2): 0.2≦c2-c1≦0.9...(C1) 5≦γ ２ -c １ ≦10 ・・・(C2)

8. An antistatic resin molded article which is a molded article of the antistatic resin composition according to claim 4.

9. 9. The antistatic resin molding according to claim 8, which is an automobile part, a building material part, a machine part, an electric or electronic part, a furniture or home appliance part, a container, a packaging material, or a film.

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