JP7533038B2 - Molded body, thermoplastic resin composition and liquid masterbatch composition used therein - Google Patents

Description

The present invention relates to a molded body, and a thermoplastic resin composition and a liquid masterbatch composition used to form the molded body.

Plastic molded products are easy to process and are therefore used in a wide range of fields, including electrical and electronic equipment parts, automotive parts, medical parts, and food containers.

However, because ordinary plastics are insulating, they easily become electrostatically charged, which can attract dirt and dust, marring the product's appearance. In addition, when the molded product is a film or sheet, electrically charged films can cause electric shocks, which can lead to explosions in the presence of flammable gases or dust.

To solve these problems, the resin that makes up the molded body is treated to prevent static electricity. The most common antistatic treatment method is to add an antistatic agent to the resin. Such antistatic agents include coating types that are applied to the surface of the molded body, and kneading types that are added when the resin is processed and molded. However, coating types have problems in that they are not very durable, and because a large amount of organic matter is applied to the surface, anything that comes into contact with the surface will become contaminated.

For this reason, techniques have been proposed for imparting antistatic properties by kneading in, for example, a resin composition containing 0.05 to 10% by mass of a sulfonate-type surfactant relative to a polylactic acid-based resin composition (Patent Document 1), or a polyester-based resin composition containing a specific sulfonate metal salt and a specific polyoxyalkylene compound in a specific ratio (Patent Document 2), using a masterbatch composition in which an antistatic agent is kneaded into the resin.

Examples of such masterbatch compositions include powdered dry colors, solid masterbatch compositions that are granular colorant compositions, and liquid masterbatch compositions. There is an increasing trend to select and use liquid masterbatch compositions, as they produce less unevenness in molded products and can provide functionality with only a small amount added.

However, when such liquid masterbatch compositions are used as the base resin for molded bodies using resins such as polyester resins and polycarbonate resins that require high temperatures during molding, the resin in the masterbatch is degraded by the double heat history during masterbatch production and molding, causing a decrease in melt viscosity (IV decrease), which can easily lead to molding defects such as drawdown. Similarly, the deterioration of the antistatic agent is accelerated, causing yellowing and a decrease in transparency, but in order to obtain sufficient antistatic performance, it becomes necessary to mix a large amount of antistatic agent. In addition, depending on the type of liquid resin and antistatic agent used, there is also the problem that hydrolysis of the base resin is accelerated due to moisture derived from the materials, resulting in insufficient film strength.

JP 2004-263158 A JP 2018-193424 A

Therefore, the problem to be solved by the present invention is to provide a molded body that has excellent antistatic properties, excellent transparency, and high film strength. In addition, the problem to be solved by the present invention is to provide a liquid master batch composition for forming the molded body that has little IV reduction.

As a result of intensive research conducted by the present inventors to solve the above problems, the present inventors have found that the above problems can be solved by a molded body formed from a thermoplastic resin composition containing a thermoplastic resin and a liquid masterbatch composition, the liquid masterbatch containing a liquid resin (A) and an antistatic agent (B), the liquid resin (A) being at least one selected from the group consisting of fatty acid polyester resin, polyalkylene glycol resin, polyether ester resin, and acetyl tributyl citrate, each having a viscosity at 25°C of less than 8,000 mPa·s and a water solubility of 45 mg/mL or less, the antistatic agent (B) having a DSC melting point of 60°C or more and less than 240°C, and the thermoplastic resin being at least one selected from the group consisting of polyester resin, polycarbonate resin, polyamide resin, cycloolefin copolymer resin, and fluororesin.

The present invention has the effect of minimizing the decrease in melt viscosity (IV decrease) compared to the case of using a conventional liquid masterbatch. Furthermore, the obtained molded body can suppress thermal deterioration during production, and can exhibit high film strength in addition to excellent antistatic properties and high transparency.

The liquid masterbatch composition, the thermoplastic resin composition, and the molded article of the present invention will be described in detail below, but the present invention is not limited thereto.
A masterbatch is a resin composition in which a high concentration of additives is dispersed in resin. It is mixed with a base resin at a specified ratio when forming a molded body, and has the role of imparting functionality to the plastic molded body.
In the present invention, the liquid masterbatch composition refers to a masterbatch that is liquid at 25°C.
Unless otherwise noted, the various components appearing in this specification may be used independently as a single type or as a combination of two or more types.

Liquid Masterbatch Composition
The liquid masterbatch composition of the present invention contains a liquid resin (A) having a viscosity of 8,000 mPa·s or less at 25° C., and an antistatic agent (B) having a DSC melting point of 60° C. or more and less than 240° C. In this case, “liquid” refers to being in a liquid state at 25° C.
By mixing such a liquid master batch composition with a thermoplastic resin described below, a molded article having excellent antistatic properties, transparency, and film strength can be formed.

<Liquid Resin (A)>
The liquid resin (A) of the present invention plays the role of a dispersion medium for dispersing the antistatic agent (B), and in addition, it has the effect of causing the antistatic agent to bleed onto the surface of the molded article, thereby promoting the manifestation of the antistatic effect.
The liquid resin (A) is at least one selected from the group consisting of fatty acid polyester resins, polyalkylene glycol resins, polyether ester resins, and acetyl tributyl citrate, which have a viscosity at 25°C of less than 8,000 mPa·s and a water solubility of 45 mg/mL or less.

As the liquid resin (A), fatty acid polyester resin, polyalkylene glycol resin, polyether ester resin, and acetyl tributyl citrate are preferred because they have high heat resistance even when the base resin requires a high molding temperature, such as polyethylene terephthalate (PET) or polycarbonate, and because they are made into the liquid master batch of the present invention and have excellent antistatic properties.

[Fatty acid polyester resin]
It is a polyester resin obtained by reacting an aliphatic polycarboxylic acid with a polyhydric alcohol.

The aliphatic polycarboxylic acid constituting the fatty acid polyester resin is not particularly limited as long as it is an aliphatic carboxylic acid having two or more carboxyl groups, and examples thereof include aliphatic polycarboxylic acids such as succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, tricarballylic acid, 1,3,6-hexanetricarboxylic acid, and 1,3,5-hexanetricarboxylic acid.

The polyhydric alcohol constituting the fatty acid polyester resin is not particularly limited as long as it is an alcohol having two or more hydroxyl groups, and examples thereof include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2 -Aliphatic glycols such as n-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-octadecanediol, and polyalkylene glycols such as diethylene glycol and dipropylene glycol, etc.

Specific examples of fatty acid polyester resins include Adekasizer PN-170 (manufactured by ADEKA Corporation, viscosity at 25°C 800 mPa·s, adipic acid polyester resin), Adekasizer P-200 (manufactured by ADEKA Corporation, viscosity at 25°C 2,600 mPa·s, adipic acid polyester resin), and Adekasizer PN-250 (manufactured by ADEKA Corporation, viscosity at 25°C 4,500 mPa·s, adipic acid polyester resin).

[Polyalkylene glycol resin]
Polyalkylene glycol resins are generally composed of alkylene glycols having a repeating unit with 1 to 6 carbon atoms, but from the viewpoints of compatibility, water absorption, and film strength, polyalkylene glycol resins having a repeating unit with 3 or more carbon atoms are preferred.

Specific examples of polyalkylene glycol resins include polytrimethylene glycol and polypropylene glycol, both of which have 3 carbon atoms in the repeating unit, and polytetramethylene glycol and polybutylene glycol, both of which have 4 carbon atoms in the repeating unit. Among these, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol, which have 3 or more carbon atoms in the repeating unit, are preferred because of their relatively low water absorption and low water solubility. Polypropylene glycol is particularly preferred because it has good compatibility with the base resin and can be used to form an excellent molded product.

[Polyetherester resin]
The polyether ester resin is obtained by esterifying the above-mentioned aliphatic polycarboxylic acid and the above-mentioned alkylene glycol.

Specific examples of polyether ester resins include Adeka Cizer RS-107 (manufactured by ADEKA Corporation, viscosity at 25°C 20 mPa·s, adipic acid ether ester resin), Adeka Cizer RS-700 (manufactured by ADEKA Corporation, viscosity at 25°C 30 mPa·s, polyether ester resin), etc.

The liquid resin (A) of the present invention is at least one selected from the group consisting of the fatty acid polyester resin, polyalkylene glycol resin, polyether ester resin, and acetyl tributyl citrate, and further has a viscosity of 8,000 mPa·s or less at 25°C and a water solubility of 45 mg/mL or less in the liquid resin (A).

The viscosity at 25° C. is more preferably 10 to 5,000 mPa·s, and even more preferably 100 to 3,000 mPa·s. A viscosity within the above range is preferred from the standpoint of antistatic properties.
In addition, it is preferable in that it is easy to prepare a liquid masterbatch composition having higher transparency and less IV reduction.
In this specification, the viscosity is a value measured at 25° C. using a B-type viscometer in accordance with JIS K7117-1:1999.

The solubility of water in the liquid resin (A) is preferably 45 mg/mL or less, more preferably 30 mg/mL or less, and particularly preferably 20 mg/mL or less. The solubility within the above range is preferable in terms of film strength. The solubility of water is preferably as close to 0 mg/mL as possible.
The solubility of water can be controlled by the structure and molecular weight of the liquid resin.
In this specification, the solubility of water refers to the amount of water that is saturated and dissolved in a solvent among the mutual solubility of the solvent and water, and is the water content in 1 mL of a solution in which water is saturated and dissolved in the solvent.
Specifically, purified water is added in 0.5 g (500 mg) increments to 100 mL of liquid resin in an atmosphere at room temperature of 23°C and humidity of 65%, and the total amount added can be determined as the amount at which separation of the liquid, loss of transparency, or cloudiness occurs.

Specific examples of fatty acid polyester resins include Adeka Cizer RS-107 (viscosity 20 mPa·s, water solubility 5 mg/mL or less), polyalkylene glycol resins include Uniol D-1200 (viscosity 200 mPa·s, water solubility 10 mg/mL), and acetyl tributyl citrates include Adeka Cizer PN-6810 (viscosity 43 mPa·s, water solubility 5 mg/mL or less).

The liquid resin (A) preferably has a number average molecular weight (Mn) of 100 to 3000, more preferably 200 to 2000, even more preferably 500 to 1500, and particularly preferably 1000 to 1500. An Mn of 100 or more is preferred in terms of suitability for film production, transparency, and film strength, while an Mn of 3000 or less is preferred in terms of dispersibility and antistatic properties.

The content of liquid resin (A) is preferably 50% by mass or more, more preferably 60 to 90% by mass, and even more preferably 70 to 80% by mass, out of 100% by mass of the liquid masterbatch composition. By being within this range, fluidity can be maintained during the stirring and dispersion steps during production, and the composition is excellent in terms of suitability for masterbatch production and dispersibility, and is also preferable in terms of the transparency of the molded body and film strength.

<Antistatic Agent (B)>
The antistatic agent (B) used in the present invention has a DSC melting point of 60° C. or more and less than 240° C., and preferably 140° C. or more and less than 200° C. By having a melting point within the above range, thermal deterioration during production can be suppressed, suitability for film production using the liquid master batch is improved, and the obtained molded article has good antistatic properties, transparency, and film strength.
In this specification, the DSC melting point refers to the melting peak temperature in differential scanning calorimetry (DSC).

The antistatic agent (B) is preferably present in the range of 10 to 40% by mass, more preferably 20 to 30% by mass, based on 100% by mass of the liquid masterbatch composition. A content of 10% by mass or more is preferred in terms of antistatic properties, and a content of 40% by mass or less is preferred in terms of suitability for film production and transparency.

The antistatic agent in the present invention is not limited, and may be a polymeric antistatic agent having a molecular weight of several thousand to several tens of thousands, or a surfactant-type antistatic agent having a molecular weight of several hundred to several thousand, as long as the DSC melting point is within the above range. Among these, surfactant-type antistatic agents are preferred because of their excellent antistatic properties and transparency, and anionic antistatic agents are particularly preferred because they provide high antistatic properties.

[Polymer-type antistatic agent]
Examples of the polymer-type antistatic agent that can be used include known polymer-type antistatic agents, such as block copolymers of a hydrophobic block and a hydrophilic block, in which the hydrophobic block and the hydrophilic block are bonded together via an ester bond, an ether bond, an amide bond, an imide bond, a urethane bond, a urea bond, or the like.

The hydrophobic block may be, for example, a polyolefin block, and examples of the polyolefin block include blocks made of polyethylene, polypropylene, and ethylene-propylene copolymer. Here, the polyolefin block may be fluorine-modified. The hydrophobic block may be, for example, a hydrophobic amine, hydrophobic ester, hydrophobic amide, hydrophobic imide, or hydrophobic ester amide having a hydrophobic group such as an alkylene group or an aromatic group, as long as it is hydrophobic. The hydrophobic block may also have a hydrophobic side chain such as an alkyl group.

Examples of hydrophilic blocks include polyether blocks, polyether-containing hydrophilic polymer blocks, cationic polymer blocks, and anionic polymer blocks. The polyether blocks are typically polyether diols, such as polyethylene glycol, polypropylene glycol, and copolymers of ethylene glycol and propylene glycol. The polyether-containing hydrophilic polymer blocks have polyether segments, such as polyether diamines, polyether ester amides, polyether amide imides, polyether esters, polyether amides, and ether urethanes. The polyether blocks and polyether segments may be linear or branched. Examples of cationic polymer blocks include cationic polymer blocks in which a quaternary ammonium salt structure or a phosphonium salt structure that counterions a superacid anion such as BF4-, PF6-, BF3Cl-, or PF5Cl- is separated by a nonionic molecular chain. In addition, the anionic polymer block may be a polymer block in which an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid having a sulfonyl group, in which only the sulfonyl group is a salt, is copolymerized with a diol or a polyether.

[Surfactant-type antistatic agent]
Examples of surfactant-type antistatic agents include anionic surfactants, nonionic surfactants, and cationic surfactants, with anionic antistatic agents being particularly preferred since they provide high antistatic properties.

Examples of anionic surfactants include carboxylates such as alkali metal salts of higher fatty acids; sulfates such as higher alcohol sulfates and higher alkyl ether sulfates; sulfonates such as alkylbenzene sulfonates, alkyl sulfonates and paraffin sulfonates; and phosphates such as higher alcohol phosphates.

Nonionic surfactants include polyethylene glycol-type nonionic surfactants such as higher alcohol ethylene oxide adducts, fatty acid ethylene oxide adducts, higher alkylamine ethylene oxide adducts, and polypropylene glycol ethylene oxide adducts; and polyhydric alcohol-type nonionic surfactants such as polyethylene oxide, fatty acid esters of glycerin, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol or sorbitan, alkyl ethers of polyhydric alcohols, and fatty amides of alkanolamines.

Examples of cationic surfactants include quaternary ammonium salts such as alkyltrimethylammonium salts, etc. Examples of amphoteric surfactants include amino acid type amphoteric surfactants such as higher alkylaminopropionate salts, betaine type amphoteric surfactants such as higher alkyldimethylbetaine and higher alkyldihydroxyethylbetaine, etc.
These can be used alone or in combination of two or more.

Because the present invention is a liquid masterbatch, migration of the antistatic agent to the surface vicinity is promoted, enabling high antistatic properties to be achieved.

The liquid master batch composition of the present invention may contain antistatic agents other than the antistatic agent (B), metal soaps of alkali metals, alkaline earth metals or zinc, hydrotalcite, flame retardants such as halogen-based, phosphorus-based or metal oxides, lubricants such as ethylene bis alkyl amide, antioxidants, ultraviolet absorbers, fillers, colorants, antiblocking agents, etc., within the scope of not impairing the effects of the present invention.

<Method for producing liquid masterbatch composition>
The method for producing the liquid masterbatch composition in the present invention is not particularly limited, and for example, the liquid resin (A), the antistatic agent (B), and further various additives as necessary are added, mixed in a Henschel mixer, a tumbler, a disperser, or the like, and dispersed using a Silverson mixer (manufactured by Silverson Corporation), to obtain the liquid masterbatch composition. In addition to the above, any other dispersing device such as a kneader, a roll mill, a ball mill, or a sand mill can be used. It is preferable to use a Silverson mixer or a roll mill because they are easy to mold and have excellent dispersibility.

In addition, the particle size of the liquid masterbatch composition is preferably less than 100 μm, more preferably less than 80 μm, and particularly preferably less than 50 μm, because this can suppress the generation of lumps and gels caused by coarse particles and can provide uniform antistatic performance on the film.

Molded body
The molded article is formed from a thermoplastic resin composition containing the liquid masterbatch composition of the present invention and a thermoplastic resin.
Examples of molded articles include sheets and films having a thickness of several tens to several hundreds of microns obtained by extrusion molding, and containers and bottles having a thickness of several hundreds of microns or more obtained by injection molding or blow molding.
In particular, since it has excellent transparency and can exhibit high antistatic properties, it is particularly effective in sheet or film-like molded articles.

The thermoplastic resin composition may be in the form of, for example, pellets, powder, granules, beads, or the like for forming a molded product, with the pellet form being preferred.
The thermoplastic resin composition can be pelletized by a general method such as extrusion molding with an extruder followed by cutting with a pelletizer, and the pelletized molded product can be pulverized to obtain a powder or granular molded product. Similarly, the extrusion molding can be followed by cutting with an underwater cutter or the like to obtain a bead-shaped molded product.

The liquid masterbatch composition can also be melt-kneaded with a thermoplastic resin to produce a thermoplastic resin composition, which can then be molded as is.

In this way, the molding method for obtaining a molded product by molding a thermoplastic resin composition containing a liquid masterbatch composition can be injection molding used for molding caps, etc., or extrusion molding or blow molding used for molding containers and bottles, etc., and is not particularly limited. However, since high antistatic properties and transparency are required, sheet or film shapes obtained by T-die molding or inflation molding are preferred.

The molded body of the present invention is suppressed from thermal degradation during production, so even when molding is performed at high temperatures such as 280°C or higher, the loss of transparency can be suppressed, and it is possible to achieve excellent antistatic properties and high film strength.

"Thermoplastic resin composition"
The thermoplastic resin composition is a resin composition for forming a molded article, which contains the liquid masterbatch composition of the present invention and a thermoplastic resin.
The content of the liquid master batch composition relative to 100 parts by mass of the thermoplastic resin is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, in terms of film production suitability and transparency. More preferred.

The content of the antistatic agent (B) is preferably 0.05 to 0.50 parts by mass, and more preferably 0.10 to 0.35 parts by mass, per 100 parts by mass of the thermoplastic resin. A content within the above range is preferable in terms of suitability for film production and transparency.

<Thermoplastic resin>
The thermoplastic resin of the present invention is a base resin to be mixed with the liquid masterbatch composition when forming a molded body, and is at least one selected from the group consisting of polyester resin, polycarbonate resin, polyamide resin, cycloolefin copolymer (COC) resin, and fluororesin, except for liquid resins having a viscosity of 8,000 mPa s or less at 25°C.
In the present invention, when a resin that requires a high temperature during molding, such as these thermoplastic resins, is used as the main resin of the molded body, by using it together with the liquid masterbatch of the present invention, the compatibility between them becomes good, and it is possible to satisfy all of high antistatic properties, transparency, and excellent film strength.

As a preferred combination of the liquid resin (A) and the thermoplastic resin, when the liquid resin (A) is a polyalkylene glycol resin, the thermoplastic resin is preferably a polyester resin or a polyamide resin from the viewpoint of suitability for film production, and is particularly preferably a polyester resin.
These combinations are preferable in that the liquid resin (A) is easily impregnated into the thermoplastic resin (D) and there is little contamination around the molding machine.

[Polyester resin]
The polyester resin can be obtained by polymerizing a carboxylic acid component (a compound having a carboxyl group) and a hydroxyl component (a compound having a hydroxyl group).

Carboxylic acid components constituting polyester resins include benzoic acid, p-tert-butylbenzoic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, itaconic acid, tetrachlorophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, trimellitic anhydride, methylcyclohexene tricarboxylic anhydride, pyromellitic anhydride, and ε-caprolactone.

Hydroxyl group components constituting polyester resins include diols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 3-methylpentanediol, and 1,4-cyclohexanedimethanol, as well as polyfunctional alcohols having three or more hydroxyl groups such as glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, and dipentaerythritol.

[Polyamide resin]
The polyamide resin can be obtained, for example, by reacting the above-mentioned carboxylic acid component with a compound having two or more amino groups. For example, the polyamide resin can be obtained by subjecting the carboxylic acid component to a dehydration condensation reaction with a compound (Am) having two or more amino groups.

Compounds (Am) having two or more amino groups may be any known compound, such as aliphatic polyamines such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and triethylenetetramine; aliphatic polyamines including alicyclic polyamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; aromatic polyamines such as phenylenediamine and xylylenediamine; and diamino alcohols such as 1,3-diamino-2-propanol, 1,4-diamino-2-butanol, 1-amino-3-(aminomethyl)-3,5,5-trimethylcyclohexane-1-ol, 4-(2-aminoethyl)-4,7,10-triazadecan-2-ol, and 3-(2-hydroxypropyl)-o-xylene-α,α'-diamine.

[Polycarbonate resin]
Polycarbonate resins can be easily produced by reacting an aromatic dihydroxy compound with a carbonate precursor such as phosgene or a carbonate diester, etc. The reaction can be carried out by a known reaction method, for example, an interfacial method when phosgene is used, or a transesterification method in which the reaction is carried out in a molten state when a carbonate diester is used.

Examples of the aromatic dihydroxy compounds include bis(hydroxyaryl)alkanes such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; Examples of the bis(hydroxyaryl)cycloalkanes include bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, and other dihydroxydiaryl ethers; 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, and other dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, and other dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, and other dihydroxydiaryl sulfones. These may be used alone or in combination of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, and 4,4'-dihydroxydiphenyls may be used in combination. In addition, branched aromatic polycarbonate resins that use polyfunctional compounds such as phloroglucinone in combination can also be used.

Examples of carbonate precursors to be reacted with the aromatic dihydroxy compound include phosgene, diaryl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

The viscosity average molecular weight of the polycarbonate resin is preferably 15,000 to 30,000, and more preferably 16,000 to 27,000. Note that the viscosity average molecular weight in this specification is a value converted from the solution viscosity measured at a temperature of 25°C using methylene chloride as a solvent.

Specific examples of polycarbonate resins include Iupilon H-4000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 16,000), Iupilon S-3000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 23,000), and Iupilon E-2000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 27,000).

[Cycloolefin copolymer (COC) resin]
The COC resin is an amorphous thermoplastic polymer having an alicyclic structure in the main chain and/or side chain. Examples of the type of alicyclic structure include norbornene polymer, monocyclic cyclic olefin polymer, cyclic conjugated diene polymer, vinyl alicyclic hydrocarbon polymer, and hydrogenated products thereof. Among them, norbornene polymer is preferably used because of its excellent moldability and transparency. Examples of monomers having a norbornene structure include bicyclo[2.2.1]hept-2-ene (common name: norbornene), tricyclo[4.3.0.12,5]deca-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.12,5]deca-3-ene (common name: methanotetrahydrofluorene), tetracyclo[4.4.0.12,5.17,10]dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (e.g., those having a substituent on the ring). Examples of the substituent include an alkyl group, an alkylene group, and a polar group.

Specific examples of COC resins include JSR ARTON F4520 (norbornene copolymer, manufactured by JSR Corporation).

[Fluororesin]
Fluorine resins can be obtained by copolymerization of fluorine-containing monomers. Examples of fluorine-containing monomers include fluorine-containing ethylenically unsaturated compounds such as vinyl fluoride, tetrafluoroethylene, trifluorochloroethylene, hexafluoropropylene, hexafluoroisobutylene, perfluoroacrylic acid, perfluoromethacrylic acid, and fluoroalkyl esters of acrylic acid or methacrylic acid, and fluorine-free ethylenically unsaturated compounds such as cyclohexyl vinyl ether and hydroxyethyl vinyl ether. Monomers copolymerized with the fluorine-containing monomers may also be fluorine-free diene compounds such as butadiene, isoprene, and chloroprene. Examples of fluorine resins include polyvinylidene fluoride resin (PVDF resin), which is a homopolymer of vinylidene fluoride, polytetrafluoroethylene resin (PTFE resin), which is a homopolymer of tetrafluoroethylene, and ethylene-tetrafluoroethylene copolymer (ETFE resin), which is a copolymer of ethylene and tetrafluoroethylene.

Specific examples of fluororesins include KF Polymer W#1100 (manufactured by Kureha Corporation, PVDF resin), Fluon PTFE CD123E (manufactured by Asahi Glass Co., Ltd., PTFE resin), and Fluon ETFE C-55AP (manufactured by Asahi Glass Co., Ltd., ETFE resin).

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, parts and percentages represent parts by mass and percentages by mass, respectively, unless otherwise specified.

<Viscosity>
The viscosity is a value measured at 25° C. using a B-type viscometer in accordance with JIS K7117-1:1999.

<DSC melting point>
The DSC melting point is the melting peak temperature in differential scanning calorimetry (DSC), and was measured under the following conditions.
Device name: Seiko Instruments Inc. DSC6200 Heating rate: 10°C/min

<Water solubility>
The solubility of water was determined by adding purified water in 0.5 g (500 mg) increments to 100 mL of liquid resin at room temperature of 23°C and humidity of 65%, and calculating the total amount added when separation of the liquid, a decrease in transparency, or cloudiness occurred at a liquid temperature of 23°C.

<Particle size>
The particle size is a value measured at 25° C. using a grindometer in accordance with JIS K5600-2-5.

<Number average molecular weight>
The number average molecular weight is the number average molecular weight converted into the molecular weight of standard polystyrene, and is measured using a high performance liquid chromatography (manufactured by Tosoh Corporation, "HLC-8320GPC") using two columns: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2 × 106, theoretical plate number: 16,000 plates/column, packing material: styrene-divinylbenzene copolymer, packing particle size: 4 μm) in series.

<Viscosity average molecular weight>
The viscosity average molecular weight is a value calculated from the solution viscosity measured at 25° C. using methylene chloride as a solvent.

The materials used are listed below.
<Liquid resin>
(A1): Uniol D-1200 (manufactured by NOF Corporation, polyalkylene glycol resin, polypropylene glycol resin, number average molecular weight 1200, viscosity 200 mPa·s, water solubility 10 mg/mL)
(A2): Uniol D-400 (NOF Corporation, polyalkylene glycol resin, polypropylene glycol resin, number average molecular weight 400, viscosity 100 mPa·s, water solubility 25 mg/mL)
(A3): Adeka Cizer RS-107 (manufactured by ADEKA Corporation, ether ester resin, adipic acid ether ester resin, number average molecular weight 430, viscosity 20 mPa·s, water solubility 5 mg/mL or less)
(A4): Adeka Cizer PN-6810 (manufactured by ADEKA Corporation, acetyl tributyl citrate, number average molecular weight 190, viscosity 43 mPa·s, water solubility 5 mg/mL or less)
(A5): Adeka Cizer PN-250 (manufactured by ADEKA Corporation, fatty acid polyester resin, adipic acid polyester resin, number average molecular weight 2100, viscosity 4,500 mPa·s, water solubility 5 mg/mL or less)
(A'1): Adeka Cizer PN-350 (manufactured by ADEKA Corporation, fatty acid polyester resin, adipic acid polyester resin, number average molecular weight 4500, viscosity 10,000 mPa·s, water solubility 5 mg/mL or less)
(A'2): PEG-400 (manufactured by Sanyo Chemical Industries, Ltd., polyalkylene glycol resin, polyethylene glycol resin, number average molecular weight 400, viscosity 90 mPa·s, water solubility 50 mg/mL)

<Antistatic Agent>
(B1): Denon V-57S (manufactured by Marubishi Chemical Co., Ltd., anionic surfactant, sodium alkanesulfonate, DSC melting point: 191° C.)
(B2): Electrostripper PC-3 (Kao Corporation, anionic surfactant, sodium alkanesulfonate, DSC melting point: 166° C.)
(B3): Electrostripper TS-5 (manufactured by Kao Corporation, nonionic surfactant, glycerin monostearate, DSC melting point: 70° C.)
(B4): PELLECTRON AS (manufactured by Sanyo Chemical Industries, Ltd., polymeric antistatic agent, polyamide-polyether copolymer, DSC melting point: 195° C.)
(B'1): Electrostripper TS-11B (manufactured by Kao Corporation, nonionic surfactant, DSC melting point: 44°C)

<Thermoplastic resin>
(D1): Polyester MA-2101M (polyester resin, manufactured by Unitika, viscosity average molecular weight 20,000)
(D2): Iupilon S-3000 (polycarbonate resin, manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 23,000)
(D3): Amilan CM3001-N (polyamide resin, manufactured by Toray, viscosity average molecular weight 50,000)
(D'1): ACRYPET VH (polymethyl methacrylate resin, manufactured by Mitsubishi Chemical Corporation, viscosity average molecular weight 50,000)

[Example 1]
70 parts by mass of the liquid resin (A1) and 30 parts by mass of the antistatic agent (B1) were mixed and dispersed in a Silverson mixer (manufactured by Silverson) to obtain a liquid masterbatch composition.
Next, 1 part by mass of the obtained liquid master batch composition and 100 parts by mass of thermoplastic resin (D1) were mixed and molded into a film at 280° C. using a T-die molding machine to obtain a single-layer film having a thickness of 100 μm.

[Examples 2 to 14, Comparative Examples 2 to 4]
A liquid master batch composition and a molded body were obtained in the same manner as in Example 1, except that the raw materials and the blending amounts (parts by mass) shown in Table 1 were used.

[Comparative Example 1]
Although 70 parts by weight of the liquid resin (A'1) and 30 parts by weight of the antistatic agent (B) were mixed and dispersed in a Silverson mixer (manufactured by Silverson Corporation), the particle size of the obtained liquid masterbatch composition was 100 μm or more, and it was not possible to obtain a liquid masterbatch composition with practical dispersibility.

<Evaluation of Liquid Masterbatch Composition>
The manufacturability of the resulting liquid masterbatch compositions was evaluated according to the following methods and criteria. The results are shown in Tables 1 and 2.

(Dispersibility Evaluation)
The particle size of the obtained liquid masterbatch composition was measured and evaluated according to the following criteria.
◯: Particle size is less than 50 μm, good △: Particle size is 50 μm or more and less than 100 μm, usable ×: Particle size is 100 μm or more, unusable

<Film evaluation>
The obtained films were evaluated for intrinsic viscosity (suitability for film production), haze (transparency), surface resistance (antistatic properties), static friction coefficient, and dynamic friction coefficient (antiblocking properties) according to the following methods and criteria. The results are shown in Tables 3 to 5.

(Film manufacturing suitability evaluation)
The intrinsic viscosity (IV) of the obtained film was measured using SS-600-L2 manufactured by Shibayama Scientific Manufacturing Co., Ltd., and the film was evaluated according to the following criteria based on the retention rate when the blended thermoplastic resin (D) was taken as 100%.
[Evaluation Criteria]
A: The IV retention rate is 95% or more, which is good.
Δ: The IV retention rate is 90% or more and less than 95%, and thus practical.
×: IV retention rate is less than 90%, unacceptable.

(Transparency Assessment)
The prepared film was allowed to stand for 24 hours in an atmosphere of 23° C. and 65% RH, and the haze (%) was measured using a HazeGuard Plus manufactured by Gardner Co., and evaluated according to the following criteria.
[Evaluation Criteria]
◯: Less than 20%, good.
Δ: 20% or more and less than 25%, practically usable.
×: 25% or more, not acceptable.

(Antistatic property evaluation)
The prepared film was allowed to stand for 24 hours in an atmosphere of 23° C. and 65% RH, and the surface resistance was measured using an R8340 High Resistance Meter manufactured by ADVANTEST Corporation, and evaluation was performed according to the following criteria.
[Evaluation Criteria]
◯: Less than 1.0×10 ¹¹ Ω/□, good.
Δ: 1.0×10 ¹¹ Ω/□ or more and less than 1.0×10 ¹³ Ω/□, and practically usable.
×: 1.0×10 ¹³ Ω/□ or more, unacceptable.

(Film strength evaluation)
The prepared film was cut to a width of 10 mm and a length of 160 mm, and was pulled in the length direction at a speed of 300 mm/min using a tensile tester (manufactured by Toyo Seiki Co., Ltd.) to measure the breaking strength of the film. The measurement was performed in accordance with JIS K7127:1999, and the film was evaluated according to the following criteria.
[Evaluation Criteria]
◯: The breaking strength is 40 MPa or more, which is good.
Δ: The breaking strength is 30 MPa or more and less than 40 MPa, and practically usable.
×: The breaking strength is less than 30 MPa, and is unacceptable.

As shown in Tables 1 and 2, the molded body of the present invention contains a specific liquid resin and a specific antistatic agent (B) in the liquid master batch used, and is liquid, so it exhibits excellent antistatic properties even with a small amount added. It was also confirmed that the obtained molded body has high film strength in addition to excellent antistatic properties and high transparency.

Claims (4)

A molded article formed from a thermoplastic resin composition containing a thermoplastic resin and a liquid masterbatch composition,
The liquid masterbatch composition comprises a liquid resin (A) or acetyl tributyl citrate and an antistatic agent (B);
The liquid resin (A) is at least one selected from the group consisting of fatty acid polyester resins, polyalkylene glycol resins, and polyether ester resins, each of which has a viscosity at 25°C of less than 5,000 mPa s and a water solubility of 30 mg/mL or less;
The antistatic agent (B) has a DSC melting point of 60° C. or more and less than 240° C.,
The molded article, wherein the thermoplastic resin is at least one selected from the group consisting of a polyester resin, a polycarbonate resin, and a polyamide resin . The molded body according to claim 1, wherein the thermoplastic resin composition contains 0.1 to 10 parts by mass of the liquid masterbatch composition per 100 parts by mass of the thermoplastic resin. A thermoplastic resin composition for forming the molded body according to claim 1 or 2. A liquid masterbatch composition for forming the molded article according to claim 1 or 2.