JP2015131911A - Method for manufacturing antistatic sheet and method for manufacturing antistatic molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an antistatic sheet, by which water resistance and solvent resistance of an antistatic coating film can be sufficiently increased while using an amorphous polyester substrate having a low heat-resistant temperature is used as a substrate.SOLUTION: The method for manufacturing an antistatic sheet includes: a surface modification step of subjecting at least one surface of an amorphous polyester substrate to a corona discharge treatment under a condition of a discharge quantity of 30 W min/mor more by using a corona discharge treatment device including a dielectric coated electrode that is a metal rod coated with a dielectric material; and a step of forming an antistatic coating film by applying a conductive polymer dispersion liquid comprising a π-conjugate conductive polymer, a polyanion, a self-crosslinking resin, and a dispersion medium on a surface of the surface-treated amorphous polyester substrate.

Description

  The present invention relates to a method for producing an antistatic sheet for producing an antistatic sheet. Moreover, this invention relates to the manufacturing method of the antistatic molded object which shape | molds an antistatic sheet.

Antistatic sheets are used as protective sheets for protecting electronic component trays and the like. As an antistatic sheet, for example, a sheet obtained by applying a dispersion containing a π-conjugated conductive polymer and a binder to the surface of a resin film substrate to form an antistatic coating film is known. (See, for example, Patent Document 1).
However, the conventional antistatic sheet coated with an aqueous solution comprising a π-conjugated conductive polymer, or a tray molded product obtained by thermoforming the antistatic sheet, is not resistant to water resistance or resistance of the antistatic coating film. There was a problem of poor solvent properties. When using antistatic sheets and tray molded products that are thermoformed, wipe them off with gauze soaked in water or alcohol to remove dirt and particles adhering to the surface. Is made. However, when the water resistance or solvent resistance of the coating film is low, there is a problem that the antistatic coating film peels off during the wiping operation.
Therefore, it has been proposed to form an antistatic coating film using an aqueous solution in which a binder and a crosslinking agent are mixed with a π-conjugated conductive polymer and to bind it to the surface of the plastic substrate with heat (for example, a patent). Reference 2).
However, in an amorphous polyester base material having low heat resistance such as amorphous polyethylene terephthalate, the water resistance and solvent resistance of the coating film may not be sufficiently improved. In the case of using a substrate having low heat resistance, it is necessary to set the drying temperature or heat treatment temperature of the coating film to 70 ° C. or less in consideration of the heat resistance of the substrate. It is necessary to perform heat treatment in a short time. However, when the binder used in combination with the crosslinking agent is heat-treated at 120 ° C. or higher, the crosslinking is instantaneously completed, but the heat treatment at a low temperature of about 70 ° C. for a short time results in insufficient binding. It has been difficult to sufficiently develop the solvent resistance.

Japanese Patent Laid-Open No. 1-225464 JP 2000-79662 A

  The present invention has been made in view of the above circumstances, and the water resistance and the solvent resistance of the antistatic coating film are sufficient even though an amorphous polyester base material having a low heat resistance temperature is used as a base material. It is an object of the present invention to provide a method for producing an antistatic sheet and a method for producing an antistatic molded body, which can be increased to a high level.

The present invention has the following aspects.
[1] Using a corona discharge treatment apparatus including a dielectric-coated electrode in which a metal rod is coated with a dielectric on at least one surface of an amorphous polyester base material, the discharge amount is 30 W · min / m ² or more. Step of surface modification by corona discharge treatment and dispersion of conductive polymer containing π-conjugated conductive polymer, polyanion, self-crosslinkable resin and dispersion medium on the surface of the surface-modified amorphous polyester base material Applying the liquid to form an antistatic coating film, and a method for producing an antistatic sheet.
[2] The method for producing an antistatic sheet according to [1], wherein the dielectric-coated electrode is an electrode in which an aluminum rod is coated with ceramic.
[3] The method for producing an antistatic sheet according to [1] or [2], wherein the self-crosslinking resin includes a polyester resin having an alkali metal salt of an acid group and a glycidyl group-containing acrylic resin.
[4] The polyester resin is a polycondensate of a dicarboxylic acid component and a diglycol component, and the dicarboxylic acid component includes a dicarboxylic acid having a sulfonic acid alkali metal salt type substituent, and the diglycol component is The manufacturing method of the antistatic sheet as described in [3] containing diethylene glycol.
[5] The method for producing an antistatic sheet according to any one of [1] to [4], wherein the amorphous polyester base material has an intrinsic viscosity of 65 cm ³ / g or more.
[6] A method for producing an antistatic molded article, wherein the antistatic sheet produced by the method for producing an antistatic sheet according to any one of [1] to [5] is molded.

  In the method for producing an antistatic sheet and the method for producing an antistatic molded article of the present invention, the water resistance of an antistatic coating film is used despite the use of an amorphous polyester base material having a low heat resistance as a base material. In addition, the solvent resistance can be sufficiently increased.

<Antistatic sheet>
An antistatic sheet produced by the method for producing an antistatic sheet of the present invention comprises an amorphous polyester base material and an antistatic coating film formed on at least one surface of the amorphous polyester base material. Prepare.

(Amorphous polyester base material)
The polyester constituting the amorphous polyester base material is mainly composed of a condensation polymer of a dicarboxylic acid component and a diol component. Examples of the dicarboxylic acid component include at least one of an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid, and examples of the diol component include at least one of an aliphatic diol and an aromatic diol.
Specifically, the polyester may be a polyethylene terephthalate (PET) homopolymer, a PET in which all or part of the terephthalic acid component is replaced with one or more other dicarboxylic acid components, or all of the PET ethylene glycol component or Those in which a part is substituted with one or more other glycol components.
Examples of the dicarboxylic acid component include orthophthalic acid, isophthalic acid, adipic acid, diphenyl carboxylic acid, diphenyl ether carboxylic acid, sebacic acid, naphthalenedicarboxylic acid and the like.
Examples of the glycol component include diethylene glycol, triethylene glycol, hexamethylene glycol, propylene glycol, cyclohexane glycol, neopentyl glycol, butylene glycol, and trimethylene glycol.

The amorphous polyester base material may contain an inorganic lubricant such as silica, talc, calcium carbonate, alumina, silica alumina, titanium oxide, zeolite, polystyrene particles, or an organic lubricant.
From the viewpoint of transparency, it is preferable that the content of the lubricant is small. The preferred lubricant content varies depending on the particle size of the lubricant. The average particle size of the lubricant is preferably 5 μm or less, and more preferably 2 μm or less. When the average particle size of the lubricant is 5 μm or less, the content of the lubricant is preferably 5000 ppm or less, and more preferably 3000 ppm or less.
In addition, the amorphous polyester base material may contain an ultraviolet absorber, a stabilizer, a pigment, other additives, and the like within a range not changing the essential properties of the polymer.

Preferably the intrinsic viscosity of the amorphous polyester is 65cm ³ / g or more, more preferably 65~95cm ³ / g, further preferably 70~90cm ³ / g. When the intrinsic viscosity of the amorphous polyester is equal to or higher than the lower limit, the rigidity and strength of the antistatic sheet and the tray produced from the sheet can be improved, and the drawability of the sheet is improved. On the other hand, if the intrinsic viscosity of the amorphous polyester is not more than the above upper limit value, the extrudability of the sheet will be good.
The intrinsic viscosity is obtained by dissolving 300 mg of a polyester sample in 30 ml of a solvent (mixed solvent of phenol and 1,1,2,2-tetrachloroethane, mass ratio = 1: 1), and dropping the sample using an Ubellose viscometer. It is obtained by measuring time and determining the intrinsic viscosity value.

In order to improve the wettability of the conductive polymer dispersion, the adhesion with the antistatic coating film, the water resistance and the solvent resistance of the antistatic coating film, the amorphous polyester substrate is subjected to surface treatment. It may be given in advance. The surface treatment will be described later.
The surface of the amorphous polyester base material that has been subjected to surface treatment preferably has a wetting index of 38 mN / m or more, and more preferably 38 to 65 mN / m. The wetting index can be measured according to JIS K6768.
If the wetting index is equal to or higher than the lower limit value, the conductive polymer dispersion is applied without being repelled, so that an antistatic coating film is easily formed.

  The thickness (average value) of the amorphous polyester base material is preferably 0.2 to 3 mm, more preferably 0.3 to 2 mm, further preferably 0.4 to 1.5 mm, and the range thereof. Among these, it adjusts suitably according to a use. If the thickness of the amorphous polyester base material is equal to or greater than the lower limit value, the moldability is improved and the rigidity and strength of the molded product are increased. On the other hand, if the thickness is equal to or less than the upper limit value, the cost can be suppressed.

(Antistatic coating)
The antistatic coating film is a film containing a π-conjugated conductive polymer, a polyanion, and a crosslinked resin.

[Π-conjugated conductive polymer]
The π-conjugated conductive polymer can be used as long as the main chain is an organic polymer having a π-conjugated system. Examples include polypyrroles, polythiophenes, polyacetylenes, polyphenylenes, polyphenylene vinylenes, polyanilines, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of easy polymerization and stability in air, polypyrroles, polythiophenes and polyanilines are preferred.
Even if the π-conjugated conductive polymer remains unsubstituted, sufficient conductivity and compatibility with the binder can be obtained, but in order to further improve conductivity and dispersibility or solubility in the binder, It is preferable to introduce a functional group such as a group, a carboxy group, a sulfo group, an alkoxy group, a hydroxy group, or a cyano group into the π-conjugated conductive polymer.

Specific examples of such π-conjugated conductive polymers include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), and poly (3-n-propylpyrrole). ), Poly (3-butylpyrrole), poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4 Dibutylpyrrole), poly (3-carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), Poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly 3-hexyloxypyrrole), poly (3-methyl-4-hexyloxypyrrole), poly (3-methyl-4-hexyloxypyrrole), polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene) , Poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3 -Phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibuty) Ruthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyl) Oxythiophene), poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), Poly (3,4-dimethoxythiophene), poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyl) Oxythiophene), poly (3,4-diheptyloxythiophene), poly (3 4-dioctyloxythiophene), poly (3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylene) Dioxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene), polyaniline, poly (2-methylaniline), poly (3 -Isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid), etc. It is below.
The above π-conjugated conductive polymers may be used alone or in combination of two or more.

  Among π-conjugated conductive polymers, polypyrrole, polythiophene, poly (N-methylpyrrole), poly (3-methylthiophene), poly (3-methoxythiophene), poly (3,4-ethylenedioxythiophene) One or two (co) polymers selected are preferably used from the viewpoints of resistance and reactivity. Furthermore, polypyrrole and poly (3,4-ethylenedioxythiophene) are more preferable because they have higher conductivity and improved heat resistance.

[Polyanion]
The polyanion is a polymer composed only of a structural unit having an anionic group, or a polymer composed of a structural unit having an anionic group and a structural unit having no anionic group.
Examples of the anion group of the _{^{polyanion, -O-SO 3 - X +}} , -SO 3 - X +, -COO - X + (. X + is the hydrogen ion in each of the formulas, represents an alkali metal ion), and the like.
That is, the polyanion is a polymer acid containing at least one of a sulfo group and a carboxy group. Among these, from the viewpoint of doping effects on the π-conjugated conductive _{^{polymer, -SO 3 - X +, -COO}} - X + are preferable.
Moreover, it is preferable that this anion group is arrange | positioned to the principal chain of a polyanion adjacently or at regular intervals.

Among the polyanions, polyisoprenesulfonic acid, a copolymer containing polyisoprenesulfonic acid, a polysulfoethyl methacrylate, a copolymer containing polysulfoethyl methacrylate, poly (4 -Sulfobutyl methacrylate), copolymers containing poly (4-sulfobutyl methacrylate), polymethallyloxybenzenesulfonic acid, copolymers containing polymethallyloxybenzenesulfonic acid, polystyrenesulfonic acid, polystyrenesulfonic acid A copolymer or the like is preferred.
The said polyanion may be used individually by 1 type, and may use 2 or more types together.

  The degree of polymerization of the polyanion is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of solvent solubility and conductivity.

  The content of the polyanion is preferably in the range of 0.1 to 10 mol, and more preferably in the range of 1 to 7 mol, with respect to 1 mol of the π-conjugated conductive polymer. When the polyanion content is less than 0.1 mol, the doping effect on the π-conjugated conductive polymer tends to be weak, and the conductivity may be insufficient. In addition, the dispersibility and solubility in the solvent are lowered, making it difficult to obtain a uniform dispersion. On the other hand, when the polyanion content is more than 10 mol, the content of the π-conjugated conductive polymer is decreased, and it is difficult to obtain sufficient conductivity.

In the polyanion, a part of its anion group is coordinated to the π-conjugated conductive polymer, and the π-conjugated conductive polymer and the polyanion form a complex. When the anion group of the polyanion is coordinated to the π-conjugated conductive polymer, the π-conjugated conductive polymer is doped to develop conductivity. An anionic group that does not coordinate to the π-conjugated conductive polymer of the polyanion serves to solubilize the complex in water.
The total content of the π-conjugated conductive polymer and the polyanion is preferably 0.05 to 5.0% by mass when the entire antistatic coating film is 100% by mass, and 0.5 to 4%. More preferably, it is 0.0 mass%. When the total content of the π-conjugated conductive polymer and the polyanion is less than 0.05% by mass, sufficient conductivity may not be obtained. May not be obtained.

[Crosslinked resin]
The crosslinked resin is a resin obtained by crosslinking a self-crosslinkable resin.
Self-crosslinking is a property capable of crosslinking even in the absence of a crosslinking agent. Self-crosslinking resins have at least one reactive functional group per molecule. Examples of the reactive functional group include a sulfonic acid group, a carboxylic acid group, or an alkali metal salt thereof, an epoxy group, and an oxetane group. These reactive functional groups may be used alone or in combination of two or more.
The crosslinked resin plays a role of binding a complex of a π-conjugated conductive polymer and a polyanion to an amorphous polyester base material.

  In the present invention, since the self-crosslinkable resin has higher water resistance and solvent resistance of the antistatic coating film, the polyester resin having an alkali metal salt of an acid group (hereinafter referred to as “polyester resin (1)”). And a glycidyl group-containing acrylic resin are preferred.

  The polyester resin (1) is a polycondensate of a dicarboxylic acid component and a diglycol component, and is a polyester resin having an alkali metal salt of an acid group (sulfonic acid group, carboxylic acid group, phosphoric acid group, etc.). Since this polyester resin (1) has a large polarity, it is excellent in water dispersibility and can be stably dispersed in water without using an emulsifier or a stabilizer.

Examples of the dicarboxylic acid component include phthalic acid, terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, 2,5-dimethyl terephthalic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and orthophthalic acid. Examples include dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, aliphatic dicarboxylic acid such as dodecanedicarboxylic acid, and alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid. Dicarboxylic acid may be used individually by 1 type, and may use 2 or more types together.
Wherein the dicarboxylic acid component, sulfonate alkali metal salt of the substituent (-SO 3 _- ^{X +,} however, X is an alkali metal ion.) Preferably includes dicarboxylic acid having a.

Sulfonic acid alkali metal salt substituent (-SO 3 _-. ^{X +,} however, X is an alkali metal ion) dicarboxylic acids having the sulfonic acid group in the dicarboxylic acid having a sulfonic acid group in the alkali metal salt Compound.
Examples of the dicarboxylic acid having a sulfonic acid group include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalenic acid-2,7-dicarboxylic acid, and derivatives thereof. Examples of the alkali metal include sodium and potassium.
Sulfonic acid alkali metal salt substituent (-SO 3 _-. ^{X +,} however, X is an alkali metal ion) The dicarboxylic acid having a sodium salt and a derivative of 5-sulfoisophthalic acid are preferred.

In the dicarboxylic acid component, acid alkali metal salt substituent (-SO 3 _-. ^{X +,} however, X is an alkali metal ion) Examples of the dicarboxylic acid component other than the dicarboxylic acids having, aromatic dicarboxylic acids Preferably, terephthalic acid and isophthalic acid are more preferable. The aromatic nucleus of the aromatic dicarboxylic acid has a high affinity with a hydrophobic plastic, high adhesion to an amorphous polyester, and excellent hydrolysis resistance.

  The dicarboxylic acid having a sulfonic acid alkali metal salt type substituent is preferably contained in the total dicarboxylic acid component in an amount of 6 to 20 mol%, more preferably 10 to 18 mol%. If the content ratio of the dicarboxylic acid having a sulfonic acid alkali metal salt type substituent is equal to or higher than the lower limit, the dispersion time of the resin in water of the polyester resin (1) can be shortened and the solvent resistance can be further increased. If it is below the said upper limit, the water resistance of a polyester resin (1) will become higher.

  Examples of the diglycol component that forms the polyester resin (1) include diethylene glycol, aliphatic having 2 to 8 carbon atoms, or alicyclic glycol having 6 to 12 carbon atoms. Specific examples of the aliphatic having 2 to 8 carbon atoms or the alicyclic glycol having 6 to 12 carbon atoms include ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, neopentyl glycol, 1,4- Examples include butanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,6-hexanediol, p-xylylene glycol, and triethylene glycol. These may be used individually by 1 type and may use 2 or more types together.

The diglycol component preferably contains diethylene glycol in order to further improve water resistance and solvent resistance.
When a diglycol component contains diethylene glycol, it is preferable to contain 20-80 mol% of diethylene glycol in all glycol components. Solvent resistance is obtained for alcohol even when the content ratio of diethylene glycol is outside the above range, but for aromatic solvents such as toluene and xylene other than alcohol, diethylene glycol is outside the above range. The solvent resistance may be insufficient.

The polyester resin (1) preferably has a number average molecular weight of 2,000 to 30,000, and more preferably 2,500 to 25,000. The number average molecular weight is a value determined by measurement with gel permeation chromatography and based on standard polystyrene.
If the number average molecular weight of the polyester resin (1) is not less than the above lower limit value, the water resistance and solvent resistance of the polyester resin (1) will be higher, and if it is not more than the above upper limit value, the water of the polyester resin (1) will be increased. Dispersibility becomes higher.

The production method of the polyester resin (1) is not particularly limited. For example, the dicarboxylic acid component and the diglycol component are esterified or transesterified at 130 to 200 ° C, and then at 200 to 250 ° C under reduced pressure conditions. The method of making polycondensation reaction is mentioned. Examples of the reaction catalyst used in the method for producing the polyester resin (1) include metal acetates such as zinc acetate and manganese acetate, metal oxides such as antimony oxide and germanium oxide, and titanium compounds.
The obtained polyester resin (1) may be added to water to form a water dispersion. Since the aqueous dispersion of the polyester resin (1) has a high solid content, it is difficult to obtain a uniform dispersion. Therefore, the polyester solid content is preferably 30% by mass or less.

  The glycidyl group-containing acrylic resin is a homopolymer of a glycidyl group-containing radical polymerizable unsaturated monomer, or a glycidyl group-containing radical polymerizable unsaturated monomer and another radical polymerizable unsaturated monomer copolymerizable with the monomer. It is a copolymer.

Examples of the glycidyl group-containing radical polymerizable unsaturated monomer include glycidyl ethers such as glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. The glycidyl group-containing radical polymerizable unsaturated monomer may be used alone or in combination of two or more.
The content ratio of the glycidyl group-containing radically polymerizable unsaturated monomer is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, based on all monomers.
It is considered that the glycidyl group-containing acrylic resin has a glycidyl group-containing radical polymerizable unsaturated monomer unit, thereby promoting self-crosslinking and improving water resistance and solvent resistance. In particular, the improvement in solvent resistance with respect to ketone solvents such as acetone and methyl ethyl ketone and ester solvents such as ethyl acetate and butyl acetate is remarkable.
Solvent resistance to alcohol can be obtained even when the content of the glycidyl group-containing radical polymerizable unsaturated monomer is less than 10% by mass, but it is resistant to ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate and butyl acetate. Insufficient sex.

Other radical polymerizable unsaturated monomers copolymerizable with glycidyl group-containing radical polymerizable unsaturated monomers include vinyl esters, unsaturated carboxylic acid esters, unsaturated carboxylic acid amides, unsaturated nitriles, unsaturated carboxylic acids, allyls. Examples thereof include compounds, nitrogen-containing vinyl monomers, hydrocarbon vinyl monomers, and vinyl silane compounds. Other radically polymerizable unsaturated monomers may be used alone or in combination of two or more.
As other radically polymerizable unsaturated monomers, it is preferable to use unsaturated carboxylic acid monomers such as acrylic acid and methacrylic acid because the effect of improving solvent resistance is further exhibited by crosslinking with a glycidyl group.
It is preferable that the content rate of an unsaturated carboxylic acid monomer is 5-20 mass% in all the monomers. If the content ratio of the unsaturated carboxylic acid monomer is equal to or higher than the lower limit value, the effect of using the unsaturated carboxylic acid monomer is sufficiently exhibited. It can suppress that property falls.

The method for producing the glycidyl group-containing acrylic resin is not particularly limited, and for example, the glycidyl group-containing acrylic resin can be produced by emulsion polymerization.
In the production of glycidyl group-containing acrylic resin by emulsion polymerization, for example, ion exchange water, a polymerization initiator and a surfactant are charged in a reaction tank, and then ion exchange water and a surfactant are charged in a dropping tank, and monomers are added. Then, after producing an emulsion, the emulsion is subjected to emulsion radical polymerization by dropping the emulsion into a reaction vessel. The reaction temperature is preferably 60 to 100 ° C., and the reaction time is preferably 4 to 10 hours.
As the surfactant used for the emulsion polymerization, one or more of an anionic surfactant, a nonionic reactive surfactant and a non-reactive surfactant can be used.
As a polymerization initiator used for emulsion polymerization, a general radical polymerizable initiator, for example, a water-soluble peroxide such as potassium persulfate, ammonium persulfate, hydrogen peroxide, benzoyl peroxide, t-butyl hydroperoxide, or the like Or an azo compound such as azobisisobutyronitrile.

When the self-crosslinking resin comprises the polyester resin (1) and the glycidyl group-containing acrylic resin, the polyester resin (1) / glycidyl group-containing acrylic resin has a solid mass in order to appropriately self-crosslink. The ratio is preferably 10/90 to 80/20, and more preferably 20/80 to 70/30.
When the polyester resin (1) is 10% by mass or more, that is, the glycidyl group-containing acrylic resin is 90% by mass or less, the adhesion to the amorphous polyester base material and the transparency of the antistatic coating film become higher. When the polyester resin (1) is 80% by mass or less, that is, when the glycidyl group-containing acrylic resin is 20% by mass or more, the water resistance and the solvent resistance become higher.

  The self-crosslinking resin may contain an antifoaming agent, a wetting agent, a surfactant, a thickening agent, a plasticizer, an antioxidant, an ultraviolet absorber, a preservative, and the like as necessary.

  The content of the crosslinked resin in the antistatic coating film is preferably 87.0 to 98.5% by mass, and more preferably 90.0 to 98.0% by mass. If the content of the crosslinked resin is not less than the lower limit, the water resistance and solvent resistance of the antistatic coating film can be further increased, and if it is not more than the upper limit, sufficient antistatic properties can be ensured.

  The thickness (average value) of the antistatic coating film is preferably from 0.01 to 10 μm, more preferably from 0.05 to 7 μm, further preferably from 0.1 to 5 μm, depending on the application. Selected.

The surface resistance value of the antistatic sheet of the present invention is preferably 1 × 10 ⁹ Ω or less, more preferably 1 × 10 ⁴ to 1 × 10 ⁹ Ω, and 1 × 10 ⁵ to 10 ⁸ Ω. More preferably it is. If the surface resistance value of the antistatic sheet is within the above range, even if it is formed into a tray molded product, generation of static electricity can be prevented, and failure and contamination of electronic components to be stored can be prevented.
The surface resistance value is a value measured according to JIS K6911.

The antistatic sheet of the present invention has a total light transmittance of 65% or more, preferably 70% or more. If the light transmittance is 65% or more, when an electronic component or the like is stored in a tray formed by deep drawing an antistatic sheet, the state of the contents can be inspected from the outside of the tray or by a camera.
The total light transmittance is a value measured according to JIS K 7136.

<Method for producing antistatic sheet>
The method for producing an antistatic sheet of the present invention comprises a surface modification step of surface-modifying at least one surface of an amorphous polyester substrate by corona discharge treatment, and a surface of the surface-modified amorphous polyester substrate. And an antistatic coating film forming step of forming an antistatic coating film by applying a conductive polymer dispersion.
Specific examples of the method for producing the antistatic sheet of the present invention include the following methods (a) to (c).
(A) Amorphous polyester is melted with an extruder, discharged from a T die attached to the extruder, and formed into a film to obtain an amorphous polyester substrate (substrate forming step). At least one surface of the amorphous polyester base material is subjected to corona discharge treatment for surface modification (surface modification step). A conductive polymer dispersion is applied to the surface of the surface-modified amorphous polyester base material and dried (antistatic coating film forming step). The antistatic sheet thus obtained is wound on a roll. This method is an inline process in which a series of steps are continuously performed.
(B) Amorphous polyester is melted with an extruder, discharged from a T-die attached to the extruder to form an amorphous polyester base material, and then wound on a roll (base material forming step). . Thereafter, the roll-shaped amorphous polyester base material is fed out, and at least one surface of the fed-out amorphous polyester base material is subjected to corona discharge treatment to perform surface modification (surface modification step). A conductive polymer dispersion is applied to the surface of the surface-modified amorphous polyester base material and dried (antistatic coating film forming step). The antistatic sheet thus obtained is again wound on a roll. This method is an off-line process in which the production of the amorphous polyester substrate and the surface modification are discontinuous.
(C) Amorphous polyester is melted with an extruder, discharged from a T-die attached to the extruder, and formed into a film to obtain an amorphous polyester substrate (substrate forming step). Thereafter, the roll-shaped amorphous polyester base material is fed out, and at least one surface of the fed-out amorphous polyester base material is subjected to corona discharge treatment to be surface-modified, and then wound on a roll (surface reforming step). Thereafter, the roll-modified amorphous polyester base material having a surface modified is fed out, coated with a conductive polymer dispersion, and dried (antistatic coating film forming step). The antistatic sheet thus obtained is again wound on a roll. This method is an off-line process in which surface modification and application of the conductive polymer dispersion are discontinuous.
Among the above (a) to (c), (a) is preferable from the viewpoint of production efficiency.

(Surface modification process)
In the corona discharge treatment in the surface modification step, a corona discharge treatment apparatus including an electrode and a counter electrode roll is used, and an amorphous polyester base material is passed between the electrode and the counter electrode roll, and a high-frequency high voltage therebetween. Is applied. Corona discharge is generated by applying a high frequency high voltage.

In the present invention, the electrode used for the corona discharge treatment is a dielectric coated electrode in which a metal rod is coated with a dielectric.
Examples of the metal rod include an aluminum rod and a stainless steel rod, and examples of the dielectric include ceramic and quartz. Among the dielectric-coated electrodes, the wettability of the conductive polymer dispersion and the water resistance and solvent resistance of the antistatic coating film are higher, and therefore, a dielectric-coated electrode in which an aluminum rod is coated with ceramic is preferable.
The counter electrode roll is a roll on which an amorphous polyester base material is wound, and is a roll installed at an arbitrary interval with respect to the electrode so that the corona discharge treatment is performed stably and uniformly.
As the counter electrode roll, a roll made of metal, such as aluminum or stainless steel, ceramic, silicone rubber, ethylene / propylene / conjugated diene copolymer rubber (EPT rubber), chlorosulfonated polyethylene rubber, etc., or chromium A roll plated with such as is used. Among these, chrome-plated stainless steel rolls and EPT rubber are lined from the standpoint of wear resistance on the roll surface, ease of wiping and cleaning, and prevention of particle contamination and chemical contamination on the surface of the amorphous polyester base material. A metal roll is preferred.
The distance between the electrode and the counter electrode roll is preferably 1 to 5 mm, and more preferably 2 to 3 mm. If the distance between the electrode and the counter electrode roll is equal to or greater than the lower limit value, processing unevenness is unlikely to occur and the coating film is likely to be uniform. If the distance is equal to or less than the upper limit value, the amorphous polyester base material is brought into contact with the electrode. Can prevent scratches.

Discharge amount in the corona discharge treatment is a 30 W · min / ^{m 2} or more, preferably 32～300W · min / ^{m 2,} and more preferably 35～250W · min / ^{m 2.}
When the discharge amount is equal to or higher than the lower limit, the surface of the amorphous polyester substrate can be sufficiently wetted by the conductive polymer dispersion, and the adhesion with the antistatic coating film, the antistatic coating film It is possible to improve the water resistance and solvent resistance. On the other hand, if the discharge amount is less than or equal to the above upper limit value, it is possible to prevent the surface of the amorphous polyester base material from being damaged and the transparency from being lowered. In addition, it is possible to suppress bleed-out of additives and the like on the surface of the amorphous polyester base material, and to improve the adhesion to the antistatic coating film and the water resistance and solvent resistance of the antistatic coating film. Can do.
When the electrode used for corona discharge is a dielectric-coated electrode and the discharge amount is 30 W · min / m ² or more, the water resistance and solvent resistance of the antistatic coating film are further improved.

The corona discharge treatment can be performed in an air atmosphere, a nitrogen gas atmosphere, an oxygen gas atmosphere, a mixed gas atmosphere of nitrogen and oxygen, or the like. Among these, since the production cost is low, it is preferable to carry out in an air atmosphere.
The frequency of discharge in the corona discharge treatment is preferably 5 to 50 kHz, and more preferably 20 to 45 kHz. If a frequency is more than the said lower limit, the uniformity of a corona discharge process will improve and a process nonuniformity can be suppressed. On the other hand, if the frequency is equal to or lower than the upper limit value, stable treatment can be achieved even when corona discharge treatment is performed at a low output.

(Antistatic coating film forming process)
In the antistatic coating film forming step, the conductive polymer dispersion applied to the surface of the surface-modified amorphous polyester base material is a π-conjugated conductive polymer, a polyanion, a self-crosslinking resin, and a dispersion medium. including.

[Dispersion medium]
As the dispersion medium, any one of water, an organic solvent, and a mixed solution of water and an organic solvent can be used.
As the organic solvent, a water-soluble solvent is preferable because the conductive polymer dispersion can be made uniform. Examples of the water-soluble solvent include alcohols such as methanol, ethanol and isopropanol, N-methyl-2-pyrrolidone, N-methylacetamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene Polar solvents such as phosphortriamide, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, phenols such as cresol, phenol, xylenol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1 , 3-butylene glycol, 1,4-butylene glycol, glycerin, diglycerin, D-glucose, D-glucitol, isoprene glycol, butanediol, 1,5-pe Polyhydric aliphatic alcohols such as tandiol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, carbonate compounds such as ethylene carbonate and propylene carbonate, ether compounds such as dioxane and diethyl ether, dialkyl ethers, Chain ethers such as propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, benzonitrile, etc. Nitrile compounds and the like. These solvents may be used alone or as a mixture of two or more.

[Method for preparing conductive polymer dispersion]
The conductive polymer dispersion described above is produced, for example, by preparing an aqueous solution containing a π-conjugated conductive polymer and a polyanion and then adding a self-crosslinking resin and a dispersion medium.

[Coating method]
Examples of the method for applying the conductive polymer dispersion include gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, phantom coater, rod coater, air doctor coater, knife coater. A coating method using a coater such as a blade coater, cast coater or screen coater, a spraying method using a sprayer such as air spray, airless spray or rotor dampening, a dipping method or the like can be applied.

After coating the conductive polymer dispersion, it is preferable to heat and dry.
The drying temperature is preferably 40 to 80 ° C, more preferably 50 to 75 ° C, and further preferably 60 to 75 ° C. If the drying temperature is 40 ° C. or higher, the sheet can be sufficiently dried even if the sheet feeding speed is high, the adhesion between the antistatic coating film and the amorphous polyester substrate, the water resistance of the antistatic coating film, and The solvent resistance can be further increased. On the other hand, if the drying temperature is 80 ° C. or lower, the amorphous polyester base material can be prevented from being softened and the sheet shape can be maintained, and white turbidity due to crystallization of the polyester can be suppressed, and the transparency of the sheet can be prevented from being lowered.
Moreover, it is preferable to cure after drying. When not cured, the antistatic coating film immediately after drying may not exhibit sufficient water resistance and solvent resistance.
As the curing conditions, it is preferable that the antistatic sheet after drying is left indoors at 20 to 50 ° C. for 20 hours or more. If cured under these conditions, the water resistance and solvent resistance of the antistatic coating film can be further increased.

(Function and effect)
As described above, in the method for producing an antistatic sheet of the present invention, a dielectric-coated electrode is used as an electrode used for corona discharge treatment of an amorphous polyester base material, and the corona discharge amount is 30 W · min / m ² or more. To do. In addition, a conductive polymer dispersion containing a π-conjugated conductive polymer, a polyanion, a self-crosslinkable resin, and a dispersion medium is applied to the surface of the surface-modified amorphous polyester base material. Thereby, even if the drying temperature of the conductive polymer dispersion after coating is lowered, an antistatic coating film that is sufficiently bound to the amorphous polyester substrate and sufficiently crosslinked can be formed. Therefore, according to the present invention, even when an amorphous polyester base material is used as the base material, the water resistance and solvent resistance of the antistatic coating film formed on the surface of the base material can be increased.

<Antistatic molding and its production method>
The antistatic molded article of the present invention is produced by molding the antistatic sheet. As an antistatic molded object, the tray molded product which accommodates an electronic component etc. is mentioned, for example.
As the molding method, for example, various thermoforming methods such as a vacuum forming method, a pressure forming method, a plug assist forming method, and a vacuum / pressure forming method can be applied. In these molding methods, it is possible to perform so-called drawing molding in which an antistatic sheet is brought into close contact with a convex or concave mold to form a concave or convex section.
Although it does not restrict | limit especially as molding temperature, 110-160 degreeC is preferable from the point of a moldability.
The surface resistance value of the antistatic molded body in the present invention is preferably 1 × 10 ⁹ Ω or less, similarly to the antistatic sheet of the present invention, and is 1 × 10 ⁴ to 1 × 10 ⁹ Ω. Is more preferable, and 1 × 10 ⁵ to 1 × 10 ⁸ Ω is even more preferable.

(Production Example 1) Preparation of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and 1.14 g of ammonium persulfate oxidizing agent solution previously dissolved in 10 ml of water was stirred at 80 ° C. The solution was added dropwise for 20 minutes and the solution was stirred for 2 hours.
1000 ml and 10,000 ml of ion-exchanged water diluted with 10% by mass of sulfuric acid diluted to 10% by mass were added to the sodium styrenesulfonate-containing solution thus obtained, and about 10,000 ml of the polystyrenesulfonic acid-containing solution was removed using an ultrafiltration method. Then, 10,000 ml of ion-exchanged water was added to the remaining liquid, and about 10,000 ml of solution was removed using an ultrafiltration method. The above ultrafiltration operation was repeated three times.
Furthermore, about 10,000 ml of ion-exchanged water was added to the obtained filtrate, and about 10,000 ml of solution was removed using an ultrafiltration method. This ultrafiltration operation was repeated three times.
The ultrafiltration conditions were as follows (the same applies to other examples).
Molecular weight cut off of ultrafiltration membrane: 30K
Cross flow type Supply liquid flow rate: 3000 ml / min Membrane partial pressure: 0.12 Pa
Water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 2) Preparation of Polystyrenesulfonic Acid Doped Poly (3,4-ethylenedioxythiophene) Aqueous Solution 14.2 g of 3,4-ethylenedioxythiophene and 36.7 g of polystyrenesulfonic acid obtained in Production Example 1 A solution dissolved in 2000 ml of ion-exchanged water was mixed at 20 ° C.
While maintaining the mixed solution thus obtained at 20 ° C. and stirring, 29.64 g of ammonium persulfate dissolved in 200 ml of ion exchange water and 8.0 g of ferric sulfate oxidation catalyst solution were slowly added, The reaction was stirred for 3 hours.
2000 ml of ion-exchanged water was added to the resulting reaction solution, and about 2000 ml of solution was removed using an ultrafiltration method. This operation was repeated three times.
Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water are added to the treatment liquid that has been subjected to the filtration treatment, and about 2000 ml of the treatment liquid is removed using an ultrafiltration method. Ion exchange water was added and about 2000 ml of liquid was removed using ultrafiltration. This operation was repeated three times.
Furthermore, 2000 ml of ion-exchanged water was added to the obtained treatment liquid, and about 2000 ml of the treatment liquid was removed using an ultrafiltration method. This operation was repeated five times to obtain about 1.2% by mass of a blue polystyrenesulfonic acid-doped poly (3,4-ethylenedioxythiophene) (PEDOT-PSS) aqueous solution.

(Production Example 3) Preparation of polyester resin A four-necked flask equipped with a distillation tube, a nitrogen inlet tube, a thermometer, and a stirrer was 854 parts by mass of dimethyl terephthalate, 355 parts by mass of 5-sodium sulfoisophthalic acid, ethylene glycol 186 parts by mass, 742 parts by mass of diethylene glycol, and 1 part by mass of zinc acetate were charged as a reaction catalyst. Thereafter, the temperature in the flask was raised from 130 ° C. to 170 ° C. over 2 hours to cause transesterification, and then 730 parts by mass of isophthalic acid and 1 part by mass of antimony trioxide were added. The temperature was raised over time to carry out the esterification reaction. Subsequently, the temperature was gradually raised and the pressure was reduced, and a polycondensation reaction was finally performed at a reaction temperature of 250 ° C. and a degree of vacuum of 5 mmHg or less for 1 hour. Then, it cooled and added ion-exchange water under normal pressure, and obtained the polyester resin whose non volatile matter is 25 mass%.

(Production Example 4) Preparation of glycidyl group-containing acrylic resin 18 parts by mass of ion-exchanged water in a beaker, Eleminol RS-3000 as a surfactant (manufactured by Sanyo Chemical Industries, Ltd., anionic surfactant, active ingredient 50% by mass) 3 parts by weight were charged. Then, 20 mass parts of glycidyl methacrylate, 13.6 mass parts of methyl methacrylate, and 6.4 mass parts of butyl acrylate were thrown in, stirring the inside of a beaker, and the monomer emulsion was produced.
Next, in a four-necked flask equipped with a condenser, a monomer dropping funnel, a thermometer, and a stirrer, 37.5 parts by mass of ion exchange water, 1 part by mass of a surfactant (Eleminol RS-3000), 0 potassium persulfate .5 parts by mass were charged. Thereafter, the atmosphere in the flask was replaced with nitrogen, followed by heating, and the monomer emulsion was added dropwise at 75 ° C. over 4 hours. The reaction was continued by maintaining the liquid temperature at 75 to 85 ° C. even after the completion of the dropwise addition, and the mixture was cooled 4 hours after the completion of the dropwise addition. After cooling, ion exchange water was further added to obtain a glycidyl group-containing acrylic resin having a nonvolatile content of 25% by mass.

(Production Example 5) Preparation of self-crosslinkable resin The polyester resin obtained in Production Example 3 and the glycidyl group-containing acrylic resin obtained in Production Example 4 were blended at a mass ratio of 50/50, and the nonvolatile content was 25% by mass. A self-crosslinking resin was obtained.

(Production Example 6) Preparation of Conductive Polymer Dispersion The PEDOT-PSS aqueous solution obtained in Production Example 2 and the self-crosslinkable resin obtained in Production Example 5 were blended at a mass ratio of 60/40 to obtain a nonvolatile content of 10 A 7% by mass of a conductive polymer dispersion was obtained.

Production Example 7 Production of Amorphous Polyester Base Material Amorphous polyethylene terephthalate resin pellets having an intrinsic viscosity of 0.82 dl / g were dried at 140 to 180 ° C. for 2 to 3 hours using a hot air dryer. . The dried pellets were supplied to a single screw extruder, melted at a cylinder temperature of 250 to 285 ° C., and the molten resin was discharged from a T die attached to the tip of the single screw extruder. By cooling the molten resin with a chill roll at 20 to 30 ° C., an amorphous polyester base material having a thickness of 0.8 mm and a width of 600 mm was produced and wound up. The obtained amorphous polyester base material had a total light transmittance of 90%.

Example 1
One surface of the amorphous polyester base material obtained in Production Example 7 was subjected to surface treatment by corona discharge treatment at a discharge amount of 40 W · min / m ² using a corona discharge treatment apparatus (manufactured by Kasuga Electric Co., Ltd.). In this example, a dielectric-coated electrode (electrode A) in which an aluminum rod is covered with ceramic is used as an electrode for corona discharge treatment, and a chromium-plated stainless steel roll (roll C) is used as a counter electrode roll facing the electrode. Using.
Next, after cutting the surface-treated amorphous polyester base material into 30 cm square, the surface-treated surface was coated with the conductive polymer dispersion obtained in Production Example 6 using a # 2 bar coater, It dried on 70 degreeC and the conditions for 1 minute using the hot-air oven. Subsequently, the film was cured for one day in a room at 25 ° C., and an antistatic coating film was formed to obtain an antistatic sheet.

(Examples 2-4, Comparative Examples 1-5)
An antistatic sheet was obtained in the same manner as in Example 1 except that the electrode for corona discharge treatment, the counter electrode roll, and the discharge amount were changed as shown in Tables 1 and 2. However, in Comparative Example 5, since the amorphous polyester base material repelled the conductive polymer dispersion, an antistatic coating film could not be formed and an antistatic sheet could not be obtained.
The electrode B for corona discharge treatment in Tables 1 and 2 is a metal electrode made of an aluminum rod, and the counter electrode roll D is a stainless steel roll lined with EPT.

<Evaluation>
The surface tension of the surface-treated surface in the amorphous polyester base material was measured as follows. The measurement results are shown in Tables 1 and 2.
The resulting antistatic sheet was evaluated for surface resistance, total light transmittance, water resistance, alcohol resistance, and vacuum formability as follows. The evaluation results are shown in Tables 1 and 2.

[surface tension]
In accordance with JIS K6768, the surface tension was measured using a wet tension test mixture (manufactured by Wako Pure Chemical Industries, Ltd.).

[Surface resistance value]
The surface resistance value (Ω) of the obtained antistatic sheet was measured according to JIS K6911 using Hiresta manufactured by Mitsubishi Chemical Corporation.

[Total light transmittance]
The total light transmittance (%) of the obtained antistatic sheet was measured according to JIS K7136 by using a Heidometer measuring device (NDH5000) manufactured by Nippon Denshoku Industries Co., Ltd.

[water resistant]
The antistatic coating film of the obtained antistatic sheet was wiped with a gauze soaked in deionized water at a pressing pressure of 10 kPa at a pressure of 10 kPa for 10 reciprocations of 10 mm, and the surface of the portion was dried. The resistance value was measured as described above.
A surface resistance value (Ω) of less than 1 × 10 ¹⁰ was evaluated as ○ (pass), and 1 × 10 ¹⁰ or more was evaluated as × (fail).

[Alcohol resistance]
The antistatic coating film of the obtained antistatic sheet was wiped with a gauze soaked in isopropyl alcohol at a pressing pressure of 10 kPa at a pressure of 10 kPa for 10 reciprocations of 100 mm. After the wiped portion was dried, the surface resistance of that portion was Values were measured as before.
A surface resistance value (Ω) of less than 1 × 10 ¹⁰ was evaluated as ○ (pass), and 1 × 10 ¹⁰ or more was evaluated as × (fail).

[Vacuum formability]
The obtained antistatic sheet was set in a vacuum forming machine with the antistatic coating film side down, and heated while measuring the sheet surface temperature with an upper heater. When the sheet surface temperature reached 120 to 140 ° C., the concave mold was lifted from the lower side and evacuated while being pressed against the sheet, and held for 20 seconds. Then, it cooled at 40 degreeC and took out the obtained molded article.
The shape and dimensions of the vacuum molded product were a circular cylinder with a diameter of the opening of 90 mm and a height of 45 mm, and the molding magnification was 3 times.
With respect to the bottom and side surfaces of the obtained vacuum molded product, the surface resistance value (Ω) of the antistatic coating film side was measured in the same manner as described above. A surface resistance value (Ω) of less than 1 × 10 ¹⁰ was evaluated as ○ (pass), and 1 × 10 ¹⁰ or more was evaluated as × (fail).

In Examples 1 to 4, even though an amorphous polyester base material was used as the base material, the obtained antistatic sheet had high water resistance and alcohol resistance, and was excellent in vacuum formability. .
In Comparative Examples 2 to 4 using an aluminum rod as an electrode for corona discharge treatment, the resulting antistatic sheet had low water resistance.
In Comparative Example 5 in which the discharge amount in the corona discharge treatment was 30 W · min / m ² or less, the wettability of the amorphous polyester base material was low, and an antistatic coating film could not be formed, and thus could not be evaluated.

  Although the present invention has been described above with specific embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above-described embodiments. Further, it is apparent from the scope of the claims that embodiments with such changes or improvements can also be included in the technical scope of the present invention.

Claims (6)

Corona discharge treatment using a corona discharge treatment apparatus having a dielectric coated electrode in which a metal rod is coated with a dielectric on at least one surface of an amorphous polyester base material under a discharge amount of 30 W · min / m ² or more. And surface modification step,
An antistatic coating film is formed by applying a conductive polymer dispersion containing a π-conjugated conductive polymer, polyanion, self-crosslinking resin and dispersion medium to the surface of the surface-modified amorphous polyester base material. Forming, and
A method for producing an antistatic sheet, comprising:   The method for producing an antistatic sheet according to claim 1, wherein the dielectric-coated electrode is an electrode obtained by coating an aluminum rod with ceramic.   The method for producing an antistatic sheet according to claim 1 or 2, wherein the self-crosslinking resin includes a polyester resin having an alkali metal salt of an acid group and a glycidyl group-containing acrylic resin.   The polyester resin is a polycondensate of a dicarboxylic acid component and a diglycol component, the dicarboxylic acid component contains a dicarboxylic acid having a sulfonic acid alkali metal salt type substituent, and the diglycol component contains diethylene glycol. The manufacturing method of the antistatic sheet | seat of Claim 3 containing. The manufacturing method of the antistatic sheet of any one of Claims 1-4 whose intrinsic viscosity of an amorphous polyester base material is 65 cm < ³ > / g or more.   The manufacturing method of the antistatic molded object which shape | molds the antistatic sheet manufactured by the manufacturing method of the antistatic sheet of any one of Claims 1-5.