KR100737182B1 - Antistatic coating composition - Google Patents

Abstract

Provided is an antistatic coating composition for forming a coating film having good adhesion, water resistance, electrical conductivity and transparency to a plastic substrate.

To prepare this, a water-soluble compound and a self-emulsifying polyester resin aqueous dispersion which are liquid at room temperature with an electrically conductive polymer, an amide group or a hydroxyl group consisting of poly (3,4-disubstituted thiophene) and poly anions are prepared. Formulate at a specific rate. Such a composition forms a coating film having good adhesion and excellent transparency, electrical conductivity, solvent resistance and especially water resistance. By mix | blending a specific amount of the alkoxysilane which has an epoxy group, the water resistance and solvent resistance of the coating film obtained further improve.

Composition for antistatic coating, electroconductive polymer, water soluble compound, self-emulsifying polyester resin water dispersion, adhesiveness, transparency, electrical conductivity, solvent resistance, water resistance

Description

Antistatic coating composition

The present invention relates to a composition for antistatic coating, which is one-liquid in water, which forms a coating film excellent in adhesion, transparency, electrical conductivity, solvent resistance and water resistance to a plastic substrate. Such a coating film is used for the surface protection film of optical components, such as various displays, such as a carrier tape, a cover tape, a tray, a word processor, a computer, a television, and a polarizing plate for electronic material packaging.

Plastics are widely used in various industrial fields because they are light, easy to mold, and do not easily corrode. However, it is also true that plastics are easy to charge and therefore their use is limited. Therefore, in order to prevent the charge, a method of kneading a surfactant, carbon black, an inorganic oxide filler, a metal powder or a π conjugated electroconductive polymer, or the like into a plastic or using these materials to process a plastic surface has been attempted. .

Examples of the π-conjugated electroconductive polymers used for antistatics include polyacetylene, poly (paraphenylene), polyaniline, polypyrrole, and polythiophene. Since most of them are difficult to dissolve in the solvent used for forming the coating film, it is difficult to form a uniform coating film easily. Therefore, these polymers are chemically modified to improve solubility (see Japanese Patent Application Laid-Open No. 7-292081) and to make a dispersion of fine particles (Japanese Patent Application Laid-Open No. 1-313521). The research which forms a uniform coating film by the method of etc. is performed.

In addition, an electrically conductive polymer consisting of poly (3,4-dialkoxythiophene) and poly anion is obtained by oxidative polymerization of 3,4-dialkoxythiophene in the presence of a poly anion. ) 1-313521], it has been noted that it has high electrical conductivity, high chemical stability and high transparency of the coating film during film formation.

However, when a coating liquid containing such an electrically conductive polymer is applied to a plastic substrate, it is very difficult to obtain a coating film which satisfies all the performances of adhesion, transparency, water resistance, solvent resistance and electrical conductivity to the substrate at the same time.

In particular, since the coating liquid containing the electroconductive polymer composed of poly (3,4-dialkoxythiophene) and polyanion contains high hydrophilic polyanion in its components, it is obtained when the binder resin is added and applied to the substrate. The water resistance of the coated film is very bad.

Therefore, in order to improve the water resistance of the coating film, a method of crosslinking the binder resin with crosslinking agents such as melamine, polycarbodiimide, polyoxazolidine, polyepoxy and polyisocyanate, and UV or EB curing as binder resin A method of forming a film by UV or EB irradiation using a resin has been attempted.

However, when a crosslinking agent is added to a coating liquid containing an electrically conductive polymer made of poly (3,4-diaalkoxythiophene) and a poly anion, there is a problem such as poor storage stability of the coating liquid and short pot life. Moreover, when drying and hardening temperature and time are not enough when forming a film | membrane, there also exists a problem that the water resistance of a coating film does not improve.

In addition, even when a UV curable resin or an EB curable resin is added as a binder resin to a coating liquid containing a poly (3,4-dialkoxythiophene) and a polyanion, as in the case of adding a crosslinking agent, There are problems such as poor storage stability and shortened port life. In addition, UV or EB irradiation equipment is required for curing the resin, which leads to an increase in manufacturing cost, which is not preferable.

Japanese Unexamined Patent Application Publication No. 6-295016 discloses such a composition for improving the above-mentioned problems of the antistatic coating liquid composition using an electrically conductive polymer composed of poly (3,4-dialkoxythiophene) and a poly anion. By containing a self-emulsifying polyester resin water dispersion containing a crosslinking agent in the present invention, it is described that an antistatic coating liquid composition having good adhesion to a PET substrate and exhibiting sufficient surface resistivity even after stretching of the substrate is obtained. However, the content of 5-sulfoisophthalic acid for improving water dispersibility in the dicarboxylic acid component of such a self-emulsifying polyester resin is high as 6 to 10 mol% and cannot be expected to impart water resistance to the coating film.

In addition, JP-A-6-73271 discloses an epoxy group for the purpose of improving the adhesion between an electrically conductive polymer layer composed of poly (3,4-diaalkoxythiophene) and a poly anion and a layer adjacent thereto. Although the alkoxysilane compound which has is used, it cannot expect to provide water resistance to a coating film.

Thus, the coating liquid is one liquid and can be formed only by drying for a short time at a relatively low temperature, and the resulting coating film is antistatic having excellent adhesion, transparency, electrical conductivity, solvent resistance and especially water resistance to the substrate, particularly the plastic substrate. Coating compositions are desired.

The present invention aims to solve the above-described problems, and its object is to provide a liquid solution in water, which forms a coating film having good adhesion to a substrate, particularly a plastic substrate, and having excellent transparency, electrical conductivity, solvent resistance and especially water resistance. It is to provide a composition for antistatic coating. In addition, in order to enable industrial coatings such as roll coating, spray coating and dipping, it is possible to provide a composition for an antistatic coating having good homogeneity and being able to form a film under relatively low temperature and short drying conditions and one liquid in an aqueous solution. The purpose.

The inventors of the present invention have conducted various studies to solve the above problems, and as a result, it is possible to form a coating film having a good adhesion to a substrate, particularly a plastic substrate, and having an excellent transparency, electrical conductivity, solvent resistance, and particularly water resistance. The composition for preventing coatings was found to complete the present invention.

That is, the present invention

An electrically conductive polymer (a) comprising a polythiophene and a polyanion in cation form consisting of a repeating structural unit of formula (1),

A water-soluble compound (b) which is a liquid at room temperature, having an amide bond or a hydroxyl group in the molecule, and

In the composition for water-based antistatic coating containing a self-emulsifying polyester resin water dispersion (c),

Water-soluble compound (b) is contained in the range of 40 to 6000 parts by weight based on 100 parts by weight of the electrically conductive polymer (a),

Self-emulsifying polyester resin water dispersion (c) is formed from aromatic dicarboxylic acid and diol,

4.0-6.0 mol% of 5-sulfoisophthalic acids are contained in the said aromatic dicarboxylic acid,

The self-emulsifying polyester resin aqueous dispersion (c) relates to a composition for waterborne antistatic coating, which is contained in a range of 20 to 5000 parts by weight as a solid with respect to 100 parts by weight of the electrically conductive polymer (a).                     

In Formula 1 above,

R ¹ and R ² independently of one another are hydrogen or a C _1-4 alkyl group or together form a C _1-4 alkylene group which may be optionally substituted.

In a more preferred embodiment, the composition for water-based antistatic coating of the present invention comprises an alkoxysilane compound (d) having an epoxy group in addition to components (a) to (c) with respect to 100 parts by weight of the electrically conductive polymer (a). It contains in the range of 20-300 weight part.

Embodiment of the invention

In the composition of the present invention, an electrically conductive polymer comprising a polythiophene (hereinafter referred to as poly (3,4-disubstituted thiophene)) and a polyanion in the form of a cation consisting of a repeating structural unit represented by the following formula (a) Is contained. In other words, such an electrically conductive polymer is a complex compound of poly (3,4-disubstituted thiophene) and poly anion.

Formula 1

Polyester constituting the electrically conductive polymer (a) R ¹ and R ² of (3,4-disubstituted thiophene) independently are hydrogen or C _1-4 alkyl group, as well as, optionally C _1-4 which may be substituted with To form an alkylene group. Suitably, 1,2-ethylene group, 1,3-propylene group, which may be substituted with an alkyl substituted methylene group, a C _1-12 alkyl group or a phenyl group. Representative examples of C _1-12 alkylene groups which may have a substituent, formed by R ¹ and R ² bonding together are 1,2-alkylene groups such as 1,2-cyclohexylene and 2,3- Butylene, etc.). These 1,2-alkylene groups are derived from 1,2-dibromoalkanes obtained by brominating α-olefins such as ethene, propene, hexene, octene, decene, dodecene and styrene. As the substituent of the C _1-12 alkylene group formed by bonding R ¹ and R ² together, methylene, 1,2-ethylene and 1,3-propylene groups, particularly 1,2-ethylene groups, are suitable.

Examples of the polyanion constituting the electrically conductive polymer (a) include polymeric carboxylic acids (e.g., polyacrylic acid, polymethacrylic acid, polymaleic acid, etc.), polymeric sulfonic acid (e.g., polystyrenesulfonic acid, polyvinylsulfonic acid, etc.). Etc. can be mentioned. In addition, these carboxylic acids and sulfonic acids may be copolymers of vinylcarboxylic acids and vinylsulfonic acids with other polymerizable monomers such as acrylates and styrene. As the poly anion, polystyrene sulfonic acid is particularly suitable.

The number average molecular weight Mn of these polyanions is preferably in the range of 1,000 to 2,000,000, more preferably in the range of 2,000 to 500,000.                     

In the composition of the present invention, a water-soluble compound (b) which is liquid at room temperature having an amide bond or a hydroxyl group in the molecule is used.

As a water-soluble compound (b1) which is a liquid at room temperature having an amide bond in a molecule, pyrrolidone-based compounds (e.g., N-methyl-2-pyrrolidone, 2-pyrrolidone, N-vinyl-2-pyrrolidone), Amide group containing compounds (for example, N-methylformamide, N, N-dimethylformamide, gamma -butyrolactone, etc.) can be mentioned.

Among these, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methylformamide, and N, N-dimethylformamide are preferable. These amide compounds can be used independently and can be used in combination of 2 or more.

As a water-soluble compound (b2) which is liquid at room temperature which has a hydroxyl group in a molecule | numerator, a polyhydric alcohol is mentioned as a preferable example. For example, glycerol, 1,3-butanediol, ethylene glycol, diethylene glycol monoethyl ether, etc. are mentioned. These can be used independently and can be used in combination of 2 or more.

In this invention, such a water-soluble compound (b) is contained in 40-6000 weight part with respect to 100 weight part of electroconductive polymers (a). When the water-soluble compound (b) is less than 40 parts by weight, the surface resistivity hardly decreases. On the other hand, when the water-soluble compound (b) exceeds 6000 parts by weight, not only the surface resistivity once lowered rises again, but also the haze value rises sharply, clouding of the coating film becomes severe, and transparency decreases.

In addition, with respect to 100 weight part of electroconductive polymers, it means with respect to 100 weight part of solid content of an electrically conductive polymer.                     

The composition of this invention contains the self-emulsifying polyester resin water dispersion (c). It is preferable that the self-emulsifying polyester resin (c) used for this invention is formed from dicarboxylic acid and diol. For example, 5-sulfoisophthalic acid alkali salts, aromatic dicarboxylic acids (e.g. terephthalic acid, isophthalic acid, phthalic acid, etc.) and diols (e.g. ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol , Neopentyl glycol, cyclohexane dimethanol, etc.) as a raw material to produce a polymerization reaction.

The dicarboxylic acid forming the self-emulsifying polyester resin may be composed of one type of dicarboxylic acid, may be used by mixing two or more types of dicarboxylic acids, or may be used in combination of three or more types. In this invention, it is most preferable that it consists of terephthalic acid, isophthalic acid, and 5-sulfoisophthalic acid, and it is especially preferable that 5-sulfoisophthalic acid is contained in dicarboxylic acid component. The coating composition containing 4.0-6.Omol% of 5-sulfoisophthalic acid has excellent water resistance. If 5-sulfoisophthalic acid is less than 4.0 mol%, the water dispersibility of resin will worsen, and if 5-sulfoisophthalic acid exceeds 6.Omol%, the water resistance of a coating film will fall.

Moreover, when aliphatic dicarboxylic acid (for example, adipic acid, succinic acid, sebacic acid, dodecane diacid, etc.) is used as a dicarboxylic acid component, there exists a tendency for the water resistance of a coating film to fall.

The self-emulsifying polyester resin water dispersion (c) is produced according to the method described in, for example, Japanese Patent Publication No. 47-40837 and provided for use. Moreover, a commercial item is also used. As a suitable material which can be obtained easily, the trade name Kapsen ES-210 etc. of Teikoku Chemical Co., Ltd. is mentioned.                     

The self-emulsifying polyester resin water dispersion (c) is added in an amount ranging from 20 to 500 parts by weight based on 100 parts by weight of the electrically conductive polymer (a) as a solid content. Preferably it is the range of 50-1500 weight part. If the addition amount of the self-emulsifying polyester resin water dispersion (c) is less than 20 parts by weight, the surface resistivity can be kept low, but no adhesion to the plastic substrate is obtained. On the other hand, when it exceeds 5000 weight part, surface resistivity becomes high.

It is also preferable to add an alkoxysilane compound (d) having an epoxy group to the antistatic coating composition of the present invention. That is, it is preferable to add the alkoxysilane compound (d) which has an epoxy group to the composition of an electroconductive polymer (a), a water-soluble compound (b), and a self-emulsifying polyester resin aqueous dispersion (c).

By adding the alkoxysilane compound (d) which has an epoxy group, the water resistance of the formed coating film improves. It has been found for the first time that an alkoxysilane compound having an epoxy group, which has conventionally been used as an adhesive such as glass fiber, improves water resistance in adhesion with plastics.

As the alkoxysilane compound (d) having an epoxy group, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane etc. are mentioned.

The addition amount of the alkoxysilane compound (d) having an epoxy group is preferably in the range of 20 to 300 parts by weight based on 100 parts by weight of the electrically conductive polymer (a). More preferably, it is the range of 40-100 weight part. If the amount is less than 20 parts by weight, the water resistance is insufficient, and even if it exceeds 300 parts by weight, the water resistance of the coating film is rather lowered.

The antistatic coating composition of the present invention comprises an electrically conductive polymer (a), a water-soluble compound (b), a self-emulsifying polyester resin aqueous dispersion (c), and, if necessary, an alkoxysilane compound (d) having an epoxy group. Obtained by mixing.

The coating film formed by the composition of the present invention can adjust the surface resistivity according to its thickness. In particular, when a thin coating film is desired, it is preferable to reduce the solid content, and for this purpose, it is preferable to dilute the composition of the present invention with a dispersion medium. As a dispersion medium to be used, water, methanol, ethanol, 2-propanol, n-propyl alcohol, isobutanol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, acetonitrile, tetrahydrofran, dioxane, mixed solvents thereof and the like Can be mentioned.

In addition, a small amount of surfactant may be added to the coating composition of the present invention for the purpose of improving the wettability to the substrate. Preferred surfactants include nonionic surfactants (e.g. polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers, sorbitan fatty acid esters, fatty acid alkylamides, etc.) and fluorinated surfactants (e.g. fluoroalkylcarboxylic acids, perfluoroalkyls). Benzene sulfonic acid, perfluoroalkyl quaternary ammonium, perfluoroalkyl polyoxyethylene ethanol and the like).

Examples of the base material for coating the antistatic coating composition of the present invention include plastic sheets, films, and nonwoven fabrics. Examples of the plastic include polyester, polystyrene, polyimide, polyamide, polysulfone, polycarbonate polyvinyl chloride, polyethylene, polypropylene, blends and copolymers thereof, phenol resins, epoxy resins, ABS resins, and the like.

Suitable coating methods are gravure coating, roll coating, bar coating, spray coating and dipping and the like.

As the drying and curing conditions of the coating film, conditions suitable for the respective coating methods are selected. When using a roll coating method, it is preferable to carry out at 60-120 degreeC and 5 to 60 second generally used by those skilled in the art.

The surface resistivity, adhesiveness, and water resistance of the coating film formed even when dried and cured above 120 ° C. are almost unchanged from those when dried and cured below 120 ° C., and therefore, even when dried and cured above 120 ° C., the coating film is advantageous in terms of performance. Not. On the other hand, when drying and curing exceeding 120 ° C., there is a problem in that the cost of forming the film is increased and the operational risk due to high temperature heating is increased. There is also a substrate that is deformed by heat.

If the drying and curing time is less than 5 seconds, the drying is insufficient, and even if dried and cured for more than 60 seconds, the surface resistivity, adhesiveness and water resistance of the formed film are almost unchanged from when drying and curing at 60 seconds or less. Even if it dries and hardens more than 60 second, it is not advantageous in terms of the performance of a coating film. On the other hand, drying and curing for more than 60 seconds increases the cost of film formation.

The coating film thus obtained is excellent in antistatic property and improves water resistance and adhesion between the coating film and the substrate. In particular, the coating film formed from the composition which mix | blended the alkoxysilane compound (d) which has an epoxy group is excellent in water resistance.

Example

Although an Example is given to the following and this invention is demonstrated, this invention is not limited to this Example.

1. Material used

In this embodiment, the following materials are used.

(a) an electrically conductive polymer

A water dispersion of polymer (Baytron P, manufactured by Bayer AG) consisting of 0.5% by weight of poly (3,4-ethylenedioxythiophene) and 0.8% by weight of polystyrenesulfonic acid (molecular weight Mn = 150,000) is used. .

(b) a water-soluble compound that is liquid at room temperature with an amide bond in the molecule

N-methylpyrrolidone

(c) Self-emulsifying polyester resin water dispersion

The dispersion of the composition (c) -1 to (c) -6 of Table 1 is manufactured. This self-emulsifying polyester resin water dispersion is prepared and used so that the solid content is 25%.                     

Self-emulsifying polyester resin Dicarboxylic acid component (mol%) Diol component (mol%) Terephthalic acid Isophthalic acid 5-sulfo isophthalic acid Adipic acid Ethylene glycol 1,4-butanediol (c) -1 60 35 5 0 70 30 (c) -2 60 35 5 0 100 0 (c) -3 60 33 7 0 70 30 (c) -4 60 30 10 0 70 30 (c) -5 40 25 5 30 30 70 (c) -6 60 37 3 0 70 30

(d) Alkoxysilane Compounds Having Epoxy Groups

3-glycidoxypropyltrimethoxysilane is used.

Etc:

Pluscoat RY-2 (manufactured by Koogaku, Fluorine-based surfactant) is used as the surfactant.

2. Application and drying method

Application and drying of the composition of the present invention or the comparative example to the plastic substrate are carried out as follows. That is, a PET film (Lumirror T type, manufactured by Toray) is used as a plastic substrate, and the coating composition is coated with a wire bar and blow-dried at 90 ° C. for 1 minute to obtain a coating film. In addition, Examples 1 to 3, 6 to 8 and Comparative Examples 1, 2, 8 to 10 were coated with a wire bar (wet 9.14 μm) of No. 4, and Examples 4, 5 and Comparative Examples 3 to 7 were No. Coating with .5 wire bar (Wet 11.43 μm).

3. Evaluation of coating

3.1 The surface resistivity is measured using a Hirester UP (MCP-HT 450, Mitsubishi Chemical Co., Ltd.) according to JIS K6911.

3.2 Water resistance is achieved by soaking the Cresia hand towel (soft type), wiping the coating 10 times by hand, and then observing the appearance of the coating. When the coating film has almost fallen off, it is determined that X, △ when the wound is outstanding, ○ when the wound is slightly observed, and ◎ when the wound is completely absent.

3.3 Solvent resistance is tested for water resistance using methanol instead of water.

3.4 Total light transmittance and haze value are measured using haze computer HGM 2B (manufactured by Sugashi Kenki Co., Ltd.) according to JIS K7150.

3.5 Adhesion to the base material of the coating film shall be carried out in accordance with the JIS eye peel test of JIS K5400.

In the examples, the electrically conductive polymer (a) is a component (a), the water-soluble compound (b) is a component (b), and the self-emulsifying polyester water dispersion (c) is a component (c) and an alkoxy having an epoxy group. The silane compound (d) may be referred to as component (d).

The compositions of the compositions of Examples 1 to 8 and Comparative Examples 1 to 10 are shown in Table 2. In Table 2, the numbers of components (a) to (d) represent g, and the electrically conductive polymer of component (a) uses a concentration of 1.3% by weight as a solid content concentration.                     

Component (a) (g) Component (b) (g) Component (c) (g)                                              Component (d) (g) Plus coat RY-2 (g) Demineralized Water (g) 2-propanol Comparative Example 1 35.0 0.0 (c) -1 6.0 0.0 0.7 58.3 0.0 Example 1 35.0 0.2 (c) -1 6.0 0.0 0.7 58.1 0.0 Example 2 35.0 2.0 (c) -1 6.0 0.0 0.7 56.3 0.0 Example 3 35.0 20.0 (c) -1 6.0 0.0 0.7 38.3 0.0 Comparative Example 2 35.0 40.0 (c) -1 6.0 0.0 0.7 18.3 0.0 Example 4 13.3 1.3 (c) -1 6.7 0.0 0.5 48.2 30.0 Example 5 13.3 1.3 (c) -2 6.7 0.0 0.5 48.2 30.0 Comparative Example 3 13.3 1.3 (c) -3 6.7 0.0 0.5 48.2 30.0 Comparative Example 4 13.3 1.3 (c) -4 6.7 0.0 0.5 48.2 30.0 Comparative Example 5 13.3 1.3 (c) -5 6.7 0.0 0.5 48.2 30.0 Comparative Example 6 13.3 1.3 (c) -1 0.1 0.0 0.5 54.8 30.0 Comparative Example 7 13.3 1.3 (c) -1 35.0 0.0 0.5 19.9 30.0 Comparative Example 8 36.5 1.0 (c) -1 5.7 0.0 0.3 31.5 25.0 Example 6 36.5 1.0 (c) -1 5.7 0.2 0.3 31.4 25.0 Example 7 36.5 1.0 (c) -1 5.7 0.3 0.3 31.2 25.0 Example 8 36.5 1.0 (c) -1 5.7 0.6 0.3 30.9 25.0 Comparative Example 9 36.5 1.0 (c) -1 5.7 1.9 0.3 29.6 25.0 Comparative Example 10 36.5 1.0 (c) -1 0.0 0.3 0.3 36.9 25.0

Examples 1 to 3 and Comparative Examples 1 and 2

The coating compositions of Examples 1-3 and Tables 1 and 2 of Table 2 were apply | coated to a plastic film by the above-mentioned method, and a coating film is evaluated. The results are shown in Table 3.

Surface resistivity (Ω /?) Total light transmittance (%) Haze value (%) Adhesion Comparative Example 1 2.4 × 10 ⁷ 88.9 2.8 100/100 Example 1 6.9 × 10 ⁶ 88.6 2.5 100/100 Example 2 2.6 × 10 ⁴ 88.9 1.9 100/100 Example 3 4.1 × 10 ⁴ 88.9 6.0 100/100 Comparative Example 2 8.2 × 10 ⁴ 89.0 8.6 100/100

Examples 1 to 3 in which component (b) is about 44 to 4400 parts by weight based on 100 parts by weight of component (a) have a low haze value and a low surface resistivity. In contrast, Comparative Example 1 does not contain component (b), so the surface resistivity is high. In the comparative example 2, since a component (b) exceeds 6000 weight part with respect to 100 weight part of components (a), haze value becomes high and transparency falls.

Examples 4, 5 and Comparative Examples 3-7

Examples 4 and 5 and Comparative Examples 3 to 5 examine the effects of the dicarboxylic acid of the self-emulsifying polyester resin of component (c). Example 4 and Comparative Examples 6 and 7 examine the addition amount of the component (c). Among the compositions shown in Table 2, the coating compositions of Examples 4, 5 and Comparative Examples 3-7 were applied to a plastic substrate and then dried at 90 ° C. for 1 minute. The results are shown in Table 4.

Self-emulsifying polyester resin Surface resistivity (Ω /?) Total light transmittance (%) Haze value (%) Adhesion Water resistance Solvent resistance Example 4 (c) -1 1.6 × 10 ⁵ 88.8 2.0 100/100 ○ △ Example 5 (c) -2 5.4 × 10 ⁵ 88.9 1.9 100/100 ○ ○ Comparative Example 3 (c) -3 5.2 × 10 ⁵ 89.0 1.9 100/100 △ Ｘ Comparative Example 4 (c) -4 1.8 × 10 ⁶ 89.4 2.1 100/100 Ｘ Ｘ Comparative Example 5 (c) -5 1.0 × 10 ⁵ 89.5 2.3 100/100 Ｘ Ｘ Comparative Example 6 (c) -1 4.7 × 10 ⁴ 88.7 2.1 45/100 Ｘ Ｘ Comparative Example 7 (c) -1 2.7 × 10 ¹⁰ 88.9 2.3 100/100 ○ △

In Examples 4 and 5, the dicarboxylic acid component of the self-emulsifying polyester resin (c) together formed terephthalic acid, isophthalic acid and 5-sulfoisophthalic acid, and contained 5 mol% of 5-sulfoisophthalic acid, thereby forming a film. Is excellent in water resistance. Example 5 is excellent in solvent resistance because the diol component in component (c) is ethylene glycol alone.

On the other hand, Comparative Examples 3 and 4 are amounts in which the dicarboxylic acid component of the self-emulsifying polyester resin (c) together contains terephthalic acid, isophthalic acid and 5-sulfoisophthalic acid, but more than 6 mol% of 5-sulfoisophthalic acid. Since it contains, the water resistance and solvent resistance of the coating film in which the film was formed are inferior. In addition, Comparative Example 5 contains 5% of 5-sulfoisophthalic acid as the dicarboxylic acid component, but contains adipic acid, which is an aliphatic dicarboxylic acid, as the dicarboxylic acid component, so that the water resistance and solvent resistance of the coating film formed with the film are poor.

In addition, since the polyester resin dispersion of Table (c) -6 of Table 1 has poor water dispersion stability, it cannot provide it to a coating composition. It is thought that this is because the 5-sulfoisophthalic acid component in the dicarboxylic acid component of a polyester resin is less than 4 mol%.

In addition, since the coating composition of Example 4 contains component (c) in an amount of about 970 parts by weight based on 100 parts by weight of component (a), the resulting coating film has good adhesion to the substrate, has low surface resistivity and excellent water resistance. have. On the other hand, since the coating composition of Comparative Example 6 contains only about 14 parts by weight of component (c) with respect to 100 parts by weight of component (a), the obtained coating film has a low surface resistivity but has poor adhesion to the substrate, Badness is also bad. On the other hand, since the coating composition of Comparative Example 7 contains about 5060 parts by weight of component (c) with respect to 100 parts by weight of component (a), the obtained coating film has good adhesion to the substrate and excellent water resistance, but the surface resistivity is greatly improved. Increases. From these results, it is preferable that component (c) is contained in the range of 20 to 5000 parts by weight based on 100 parts by weight of component (a) from the viewpoint of providing adhesion to the substrate, low surface resistivity and high water resistance of the coating film. appear.

Examples 6-8 and Comparative Examples 8-10

These Examples 6-8 and Comparative Examples 8-9 examine the addition effect of the alkoxysilane which has an epoxy group of component (d). Comparative Example 10 examines the water resistance and the solvent resistance of a coating film in which a film is formed in the coating composition in which component (d) is added and component (c) is removed. Among the compositions shown in Table 2, the coating compositions of Examples 6-8 and Comparative Examples 8-10 were applied to a plastic substrate and then dried at 90 ° C. for 1 minute. The results are shown in Table 5.

Surface resistivity (Ω /?) Total light transmittance (%) Haze value (%) Adhesion Water resistance Solvent resistance Comparative Example 8 4.0 × 10 ⁴ 88.8 2.0 100/100 Ｘ Ｘ Example 6 3.5 × 10 ⁴ 88.9 2.0 100/100 ○ △ Example 7 5.2 × 10 ⁴ 89.0 2.0 100/100 ◎ △ Example 8 5.9 × 10 ⁴ 89.1 2.0 100/100 ○ △ Comparative Example 9 7.5 × 10 ⁴ 89.2 2.1 100/100 Ｘ Ｘ Comparative Example 10 2.8 × 10 ⁴ 88.3 2.2 100/100 Ｘ Ｘ

The results in Table 5 show that the addition of component (d) improves the water resistance and solvent resistance of the coating film, but when the addition amount exceeds a certain amount, the water resistance and solvent resistance of the coating film are lowered. Component (d) was found to be added at about 60 parts by weight to 100 parts by weight of component (a) in terms of imparting water resistance and solvent resistance.

In addition, from the results of Comparative Example 10, even if component (d) was added, it was found that if the component (c) was not added, the adhesion to the substrate of the coating film on which the film was formed was obtained, but water resistance and solvent resistance were not obtained.

In addition, the adhesiveness with respect to the base material of a coating film is favorable as 100/100 (checker eye peeling test) in the Example and comparative example other than the comparative example 6.

According to the present invention, there is provided a composition for antistatic coating, which is a one-liquid type in water, which forms a coating film having good adhesion to a plastic substrate and having excellent transparency, electrical conductivity, solvent resistance and especially water resistance. The coating composition of the present invention is an electrically conductive polymer (a) containing a polythiophene and a polyanion in cation form composed of specific repeating structural units, a water-soluble compound that is a liquid at room temperature having an amide bond or a hydroxyl group in a molecule thereof. By mixing (b) and the self-emulsifying polyester resin water dispersion (c) in a specific ratio, a coating film having good adhesion and excellent transparency, electrical conductivity, solvent resistance and especially water resistance is formed. When mix | blending the alkoxysilane (d) which has an epoxy group, the water resistance and solvent resistance of the coating film obtained further improve.

Claims (2)

An electrically conductive polymer (a) comprising a polythiophene and a polyanion in cation form consisting of a repeating structural unit of formula (1), A water-soluble compound (b) which is a liquid at room temperature, having an amide bond or a hydroxyl group in the molecule, and In the composition for water-based antistatic coating containing a self-emulsifying polyester resin water dispersion (c), Water-soluble compound (b) is contained in the range of 40 to 6000 parts by weight based on 100 parts by weight of the electrically conductive polymer (a), Self-emulsifying polyester resin water dispersion (c) is formed from aromatic dicarboxylic acid and diol, 4.0-6.0 mol% of 5-sulfoisophthalic acids are contained in the said aromatic dicarboxylic acid, The composition for water based antistatic coating in which the self-emulsifying polyester resin aqueous dispersion (c) is contained in 20 to 5000 weight part as solid content with respect to 100 weight part of electroconductive polymers (a). Formula 1

In Formula 1 above, R ¹ and R ² independently of one another are hydrogen or a C _1-4 alkyl group or together form a C _1-4 alkylene group which may be optionally substituted. The aqueous antistatic coating composition according to claim 1, further comprising an alkoxysilane compound (d) having an epoxy group in the range of 20 to 300 parts by weight based on 100 parts by weight of the electrically conductive polymer (a).