KR100364242B1 - Antistatic transparent black coating composition, producing method thereof, and coating method of glass surface using thereof - Google Patents

Abstract

The present invention relates to a coating composition used for coating a CRT (Cathod Ray Tube) glass surface, and more particularly to a coating composition used for coating a glass surface of CRT (Cathod Ray Tube) The present invention relates to an antistatic coloring coating composition, a method for producing the same, and a coating method of a glass surface using the composition. The coating composition of the present invention is excellent in properties such as weather resistance, adhesion, hardness and the like, There is an advantage in that a good appearance is provided and the production cost is low.

Description

TECHNICAL FIELD [0001] The present invention relates to an antistatic coloring coating composition, an antistatic coloring coating composition, a method for producing the same, and a coating method for coating a glass surface using the antistatic coloring coating composition,

TECHNICAL FIELD The present invention relates to an antistatic colored coating composition used for coating a CRT (Cathod Ray Tube) glass of a television, a production method thereof, and a coating method of a glass surface using the same, and more particularly to an aqueous solution of polyethylene dioxythiophene, The present invention relates to an antistatic colored coating composition comprising an alcohol and an amide based mixed solvent, an alkoxysilane, a water-soluble polymer, a sulfonic acid monomer dopant, and a water-dispersible carbon black, a production method thereof and a coating method using the glass surface.

An antistatic colored coating agent is used in the flat cathode ray tube outer glass of a color TV to improve the contrast and prevent electrostatic shock. Representative examples of the coating solution developed for this purpose include a coating solution in which carbon powder is dispersed in antimonitoxide sol and silica sol solution (U.S. Patent No. 5,681,885), a conductive polymer and a silacarazole solution in which carbon powder is dispersed Lt; / RTI > However, the stability of the dispersed carbon powder is not sufficient in such coating liquids, so that the carbon powder is gelled and the carbon particles are not sufficiently made into fine particles, resulting in poor appearance of radial patterns such as combs in the coating layer. Further, since an organic polymer is used as a dispersing agent, the hardness of the coating film is lowered and scratches easily occur. The surface resistivity of the coating film is about 10 ¹⁰ -10 ¹¹ Ω / □ and the antistatic property is insufficient. In addition, since the ultrasonic dispersion method is mostly used for the production of the coating liquid, the productivity of the coating liquid is low.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an antistatic colored coating composition which is excellent in physical properties such as hardness and surface resistance of a coating film and high in productivity, solves the problems of the coating solution for CRT.

It is still another object of the present invention to provide a method for producing the antistatic colored coating composition and a method for coating the glass surface using the same.

That is, one aspect of the present invention provides an antistatic colored coating composition comprising an aqueous solution of polyethylene dioxythiophene, an alcohol and an amide based mixed solvent, an alkoxysilane, a water-soluble polymer, a sulfonic acid monomer dopant, and a water-dispersible carbon black will be.

Another aspect of the present invention relates to a method of making the above antistatic colored coating composition comprising: (a) introducing an aqueous solution of polyethylene dioxythiophene into a reactor to start stirring; (b) continuously adding an alcohol and an amide-based mixed solvent, an alkoxysilane, a sulfonic acid monomer dopant, and a water-soluble polymer sequentially while stirring, and then stirring for 6 hours or more; (c) adding water-dispersible carbon black again and stirring for 2 hours or more.

Another aspect of the present invention is characterized in that the composition is coated on the glass surface at a speed of 80 to 150 rpm over a period of 80 to 150 seconds by a spin method and then thermally fired at 150 to 200 DEG C for 30 minutes to 1 hour To a method of coating a glass surface.

Hereinafter, the present invention will be described in more detail.

A preferred antistatic colored coating composition of the present invention comprises

A polyethylene dioxythiophene aqueous solution having a solid content of 0.6 to 3.0% by weight

6 to 26% by weight;

64 to 90% by weight of an alcohol and amide-based mixed solvent;

3 to 10% by weight of alkoxysilane;

0.005 to 0.1% by weight of a water-soluble polymer;

0.005 to 0.05% by weight of a sulfonic acid monomer dopant; And

0.05 to 0.40% by weight of water-dispersible carbon black

.

As the conductive polymer compound in the antistatic colored coating composition of the present invention, an aqueous solution of polyethylene dioxythiophene is used.

Polyaniline, polypyrrol, and polythiophene are widely used as the conductive polymer compound. These polymer compounds have been attracting attention for a long time as a synthetic metal because they are easy to polymerize and have excellent electrical conductivity and have been proposed to be applicable to various conductive materials such as an electromagnetic wave material, an electrode of a secondary battery, and a transparent electrode. However, these are only a few examples of successful commercialization since they are difficult to process and the safety of heat, air, and ultraviolet light is very poor.

Recently, polyethylenedioxythiophene as described in U.S. Patent Nos. 5,035,926 and 5,391,472 has been attracting attention as a conductive material by solving the problems of the conventional conductive polymer. Since polyethylene dioxythiophene has characteristics such as excellent solubility, excellent atmospheric air, heat and ultraviolet rays stability compared to other conductive polymers such as polyaniline type, polypyrrole type and polythiophene type, It can be applied to the formation of a conductive coating film at an exposed site. In addition, since polyethylene dioxythiophene is doped with a polymeric acid (polystyrenesulfonic acid), it can be prepared as an aqueous solution. Since the aqueous solution of the polymer is easily mixed with an alcohol solvent, it exhibits excellent solvent processing characteristics rarely as a conductive polymer.

The polyethylene dioxythiophene can be used as a conductive coating agent such as an electromagnetic shielding material and an antistatic agent applied to a substrate such as a CRT glass surface or a transparent plastic surface (panel, film).

The amount of the aqueous solution of polyethylene dioxythiophene (solid content: 0.6 to 3.0% by weight) in the antistatic colored coating composition of the present invention is preferably 6 to 26% by weight. More preferably, an aqueous solution of polyethylene dioxythiophene having a solid content of 1.2 to 1.5% by weight is used. When the content of the aqueous solution of polyethylene dioxythiophene is less than 6% by weight, the surface resistance is 10 ¹⁰ Ω / □ or more, which is more than the commercial level target of 10 ⁸ to 10 ¹⁰ Ω / □ and the antistatic property is insufficient. In the above case, the surface resistance is about 10 ⁸ Ω / □ and the antistatic property is good, but the viscosity of the composition is high and a uniform coating film can not be produced.

In the composition of the present invention, an alcohol and amide mixed solvent is used in order to improve the conductivity of the coating film and maintain excellent dispersibility and film uniformity. The use of a mixture of two solvents improves the conductivity of the coating film to improve antistatic properties and also improves the dispersibility of the carbon black, thereby eliminating appearance defects due to combs on the coating film.

As the alcoholic solvent, at least one selected from the group consisting of methanol, ethanols, propanol and isopropanol can be used.

Examples of the amide solvent include formaldehyde, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, At least one selected from the group consisting of

The amount of the alcohol and amide-based mixed solvent is suitably from 64% by weight to 90% by weight. In detail, the mixing ratio of the solvent is preferably from 94 to 99% by weight of the alcohol solvent and from 1 to 6% by weight of the amide solvent, and more preferably, the content of methanol in the total solvent mixture is at least 50% by weight.

In the composition of the present invention, a water-soluble polymer is used as a dispersant for assisting dispersion of polyethylene dioxythiophene. Polyethylene dioxythiophene is dispersed in the conductive polymer itself by doping with polystyrenesulfonic acid (-SO ₃ H, -SO ₃ ^- Na) serving as a dispersing agent, but when the amount of the aqueous solution of polyethylene dioxythiophene is less than 10% , The water-soluble or alcohol-soluble polymer is used as a dispersant and a resin binder since the dispersibility and adhesion to the substrate surface are not sufficient.

The water-soluble polymer used as a dispersing agent in the composition of the present invention may be selected from the group consisting of polymethacrylic acid, polyacrylic acid, polyvinyl alcohol, polyvinylbutyral, methylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, polyvinyl acetate One species is selected.

The water-soluble polymer is preferably added in the form of an alcohol solution or an aqueous solution. The amount of the water-soluble polymer to be used is suitably 0.005 to 0.1% by weight based on the solids content. When the solid content is less than 0.005% by weight, the effect of improving the adhesion with the substrate is not sufficient and the dispersibility is impaired. When the content is more than 0.1% by weight, the viscosity of the composition increases, which hinders uniform coating film formation and causes poor appearance.

In the composition of the present invention, a sulfonic acid monomer dopant is used as a conductive auxiliary agent. Polyethylene dioxythiophene is a sulfonic acid monomer dopant which is used as a conductive additive because its conductivity is very low due to silica sol which is a binder in the coating film state. The sulfonic acid monomer dopant is further doped to the polyethylene dioxythiophene molecule to increase the conductivity of the coating film.

Examples of the sulfonic acid monomer dopant include sulfonic acids such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, 1,5-anthraquinone disulfonic acid, 2,6-anthraquinone disulfonic acid, anthraquinone sulfonic acid, Sulfonic acid, and the like. In the case of the acid form, it is used as it is, and when it exists in the form of sodium (Na) salt, it is used in the acid form by using nitric acid aqueous solution of pH 2.

The sulfonic acid monomer dopant is preferably added in the form of an aqueous solution in terms of dispersibility. The addition amount is suitably from 0.005 to 0.05% by weight based on the solid content. If the solid content is less than 0.005 wt%, the desired conductivity increase effect is not exhibited in the present invention. If the solid content is more than 0.05 wt%, the dispersibility becomes poor and the conductivity is lowered, which is not preferable.

In the composition of the present invention, the alkoxysilane is used for enhancing the adhesion to the outer surface glass of the cathode ray tube and imparting hardness of the coating film when the composition is coated. The alkoxysilane may be one selected from the group consisting of tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane and methyltriethoxysilane, and the water contained in the aqueous solution of polyethylene dioxythiophene (R-SiO ₂ -SiO ₂ -) is formed by hydrolysis reaction and condensation reaction with the addition of water or a further added water to form silica sol (-SiO ₂ -SiO ₂ -) and alkyl silica sol (R-SiO ₂ -SiO ₂ -). The silica sol forms a polysilicate crystal upon thermal curing coating, thereby enhancing the adhesion between the coating film and the outer surface glass of the cathode ray tube and increasing the hardness of the film.

In the composition of the present invention, the amount of the alkoxysilane is preferably 3 wt% to 10 wt%. When the amount of alkoxysilane is less than 3% by weight, hardness of 5H or more can not be attained. When the amount of alkoxysilane is more than 10% by weight, the hardness becomes very excellent, but the amount of polysilicate which adversely affects the conductivity is relatively increased. It is impossible to achieve a surface resistance of about 10 ⁸ to 10 ¹⁰ Ω / m ² required by the present invention.

In the composition of the present invention, water-dispersible carbon black is used as a coloring agent. In the present invention, a water-dispersible carbon surface-modified by covalent bonding with a sulfonate or carboxylate is used. In this case, a stable dispersion state is maintained in water or an alcohol solvent without adding organic substances such as surfactants, dispersants, and polymers used for maintaining stable dispersibility of carbon. When such a carbon black is used to form a coating film, excellent film hardness and high optical density can be obtained, and there is an advantage that black color is hardly eluted on the film surface. The sulfonate and carboxylate present in the carbon powder can also act as a doping agent in the polyethylene dioxythiophene, thereby improving the film conductivity and improving the antistatic property. In addition, due to the stable dispersibility in water or an alcohol solvent, the use of a high content of carbon also has the effect of preventing appearance defects caused by combs of the coating film frequently occurring.

In the present invention, the water-dispersible carbon is preferably used in an amount of 0.05 to 0.40% by weight based on the solid content. If it is used in an amount of less than 0.05% by weight, the desired minimum permeability of 80% or less can not be achieved in the present invention. If it exceeds 0.40% by weight, the permeability is extremely improved to not more than 40%, but the content of carbon solids is too large, It is bad because of badness.

Hereinafter, a method for producing the antistatic colored coating composition of the present invention will be described.

First, an aqueous solution of polyethylene dioxythiophene was added to the reactor to start stirring. While the stirring was continued, an alcohol and amide mixed solvent, alkoxysilane, sulfonic acid monomer dopant and water-soluble polymer were sequentially added and stirred for 6 hours or longer to obtain polyethylene dioxy Lt; / RTI > and a sol-gel solution are prepared.

Next, water-dispersible carbon black is added to the resulting polyethylene dioxythiophene and silica sol solution, and the mixture is stirred for 2 hours or more to prepare an antistatic colored coating composition of the present invention.

When the order of addition of the constituent materials in the above-described production is changed or the production method is different, the desired effect in the present invention can not be sufficiently exhibited.

Hereinafter, a method of coating the glass surface with the antistatic colored coating composition of the present invention will be described.

First, the glass surface is polished with cellum oxide, washed with ethanol and dried.

Next, the antistatic colored coating composition of the present invention is coated on a glass surface by a spin method and dried. The coating may be carried out at a speed of 80 to 150 rpm over 80 to 150 seconds.

Finally, heat curing is performed at 150 to 200 DEG C for 30 minutes to 1 hour to form a hard film.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are merely illustrative of the present invention and are not intended to limit the scope of the appended claims.

Examples 1 to 8 and Comparative Examples 1 to 8

An aqueous solution of polyethylene dioxythiophene was added to a glass container having a size of 1 L and an alcohol and an amide-based solvent, an alkoxysilane, a sulfonic acid monomer dopant and a water-soluble polymer were sequentially added at a mixing ratio shown in Tables 1 and 2, And stirred at room temperature for about 8 hours. Next, a water-dispersible carbon black aqueous solution was added to the composition and stirred for about 4 hours to complete the coating composition.

Using the above composition, specimens were prepared in the following manner. First, the glass was thoroughly cleaned with acid, and the dried glass was preheated at 35 DEG C and then coated on the glass surface by spin coating at 120 rpm for 120 seconds. The specimens were baked in an oven at 180 ° C for 30 minutes.

Polyethylene dioxythiophene Alcohol and amide-based mixed solvents Sulfonic acid monomer dopant Water-soluble polymer Alkoxysilane Water-dispersed carbon black Example 1 PEDT (1.3%, aq.) = 8% MeOH / NMP = 74% / 4% p-TSA (1%, aq.) = 1% HPC (1%, MeOH) = 1% TEOS = 5% CB200 (5%, aq.) = 7% Example 2 PEDT (1.3%, aq.) = 12% MeOH / NMAA = 70% / 3% p-TSA (1%, aq.) = 2% MC (1%, aq.) = 3% TEOS = 6% CB200 (5%, aq.) = 6% Example 3 PEDT (1.3%, aq.) = 18% MeOH / EtOH / NMP = 54% / 10% / 3% MSA (1%, aq.) = 1% MC (1%, aq.) = 1% TEOS = 8% CB300 (5%, aq.) = 5% Example 4 PEDT (1.3%, aq.) = 23% MeOH / EtOH / NMP = 47% / 10% / 3% MSA (1%, aq.) = 1% PAA (1%, aq.) = 1% TEOS = 8% CB300 (5%, aq.) = 7% Example 5 PEDT (1.3%, aq.) = 22% MeOH / IPA / DMF = 58% / 5% / 3% NBSA (1%, aq.) = 1% HEC (1%, MeOH) = 1% TEOS = 8% CB200 (5%, aq.) = 2% Example 6 PEDT (1.3%, aq.) = 8% MeOH / NMP = 72% / 6% 4-HBSA (1%, aq) = 2% PMAA (1%, aq.) = 2% TEOS = 3% CB200 (5%, aq.) = 7% Example 7 PEDT (1.3%, aq.) = 24% MeOH / NMAA = 63% / 3.6% p-TSA (1%, aq.) = 0.7% PVB (1%, MeOH) = 0.7% mTEOS = 6% CB200 (5%, aq.) = 2% Example 8 PEDT (1.3%, aq.) = 10% MeOH / NMP = 74% / 3% p-TSA (1%, aq.) = 4% HPC (1%, MeOH) = 3% TEOS = 4% CB200 (5%, aq.) = 2%

Polyethylene dioxythiophene Alcohol and amide-based mixed solvents Sulfonic acid monomer dopant Water-soluble polymer Alkoxysilane Water-dispersed carbon black Comparative Example 1 PEDT (1.3%, aq.) = 4% MeOH / NMP = 80% / 2% p-TSA (1%, aq.) = 4% HPC (1%, MeOH) = 2% TEOS = 4% CB200 (5%, aq.) = 4% Comparative Example 2 PEDT (1.3%, aq.) = 30% MeOH / EtOH / NMP = 40% / 10% / 6% p-TSA (1%, aq.) = 1% HPC (1%, MeOH) = 1% TEOS = 8% CB200 (5%, aq.) = 4% Comparative Example 3 PEDT (1.3%, aq.) = 8% MeOH / NMP = 79% / 2.9% p-TSA (1%, aq.) = 0.1% HPC (1%, MeOH) = 2% TEOS = 4% CB300 (5%, aq.) = 4% Comparative Example 4 PEDT (1.3%, aq.) = 8% MeOH / NMP = 67% / 4% p-TSA (1%, aq.) = 7% HPC (1%, MeOH) = 2% TEOS = 6% CB300 (5%, aq.) = 6% Comparative Example 5 PEDT (1.3%, aq.) = 10% MeOH / NMP = 76% / 2% p-TSA (1%, aq.) = 2% HPC (1%, MeOH) = 2% TEOS = 2% CB300 (5%, aq.) = 6% Comparative Example 6 PEDT (1.3%, aq.) = 12% MeOH / NMP = 60% / 5% p-TSA (1%, aq.) = 2% HPC (1%, MeOH) = 2% TEOS = 12% CB200 (5%, aq.) = 7% Comparative Example 7 PEDT (1.3%, aq.) = 22% MeOH / NMP = 65% / 4.5% p-TSA (1%, aq.) = 1% HPC (1%, MeOH) = 1% TEOS = 6% CB200 (5%, aq.) = 0.5% Comparative Example 8 PEDT (1.3%, aq.) = 12% MeOH / NMP = 62% / 5% p-TSA (1%, aq.) = 3% HPC (1%, MeOH) = 3% TEOS = 5% CB300 (5%, aq.) = 10%

* PEDT (polyethylene dioxythiophene); Baytron PH 4071 from Bayer

* MeOH, EtOH, NMP (N-methylpyrrolidone), DMF (N, N-dimethylformamide), NMAA (N-methylacetamide); Aldrich

* p-TSA (p-toluenesulfonic acid), MSA (methylsulfonic acid), NBSA (nitrobenzenesulfonic acid), 4-HBSA (4-hydroxybenzenesulfonic acid); Aldrich

* HPC (hydroxypropyl cellulose), MC (methyl cellulose), PAA (polyacrylic acid), PMAA (polymethacrylic acid), PVB (polyvinyl butyral), HEC (hydroxyethyl cellulose); Aldrich

* TEOS (tetraethoxysilane), mTEOS (methyltriethoxysilane); Aldrich

* CB200 (sulfonate carbon black), CB300 (carboxylate carbon black); Cabot Corp

Resistance (Ω / □) Transmittance (T%) Hardness (H) Membrane appearance Example 1 8x10 ⁹ 46 6 Good Example 2 6x10 ⁹ 50 6 Good Example 3 6x10 ⁸ 51 7 Good Example 4 4x10 ⁸ 42 7 Good Example 5 4x10 ⁸ 70 5 Good Example 6 4x10 ⁹ 65 4 Good Example 7 7 x ^{10 8} 68 6 Good Example 8 8x10 ⁹ 72 5 Good Comparative Example 1 4x10 ¹¹ 65 5 Good Comparative Example 2 2x10 ⁸ 45 4 Bad Comparative Example 3 2x10 ¹¹ 60 4 Good Comparative Example 4 4x10 ¹⁰ 55 5 Bad Comparative Example 5 8x10 ⁸ 56 2 Good Comparative Example 6 8x10 ¹¹ 48 8 Good Comparative Example 7 4x10 ⁸ 85 6 Good Comparative Example 8 2x10 ⁹ 42 5 Bad

Surface resistance; Evaluated by Ultrehigh resistance (Advantest)

* Transmittance; Evaluated by ASTM D1003 method

* Pencil hardness; Evaluated by ASTM D3502 (pencil hardness tester, toyoseki) method

* Membrane appearance; Evaluated by visual observation

The antistatic colored coating composition of the present invention is excellent in physical properties such as weather resistance, adhesion, and hardness, and has a good appearance when coated on the outer glass of a CRT, and has a low production cost.

Claims (9)

A polyethylene dioxythiophene aqueous solution having a solid content of 0.6 to 3.0% by weight 6 to 26% by weight; 64 to 90% by weight of an alcohol and amide-based mixed solvent; 3 to 10% by weight of alkoxysilane; 0.005 to 0.1% by weight of a water-soluble polymer; 0.005 to 0.05% by weight of a sulfonic acid monomer dopant; And And 0.05 to 0.40% by weight of water-dispersible carbon black. delete The antistatic colored coating composition according to claim 1, wherein the solid content of the aqueous solution of polyethylene dioxythiophene is 1.2 to 1.5% by weight. The antistatic coloring coating composition according to claim 1, wherein the added alkoxysilane reacts with water to undergo hydrolysis and condensation to form a silica sol. The method according to claim 1, wherein the alcohol-based solvent is at least one selected from the group consisting of methanol, ethanol, propanol, and isopropanol, The amide-based solvent may be selected from the group consisting of formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, Money, and more than one kind selected from the crowd consisting of money, The alkoxysilane is one kind selected from the group consisting of tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane, The sulfonic acid monomer dopant may be at least one member selected from the group consisting of p-toluenesulfonic acid, dodecylbenzenesulfonic acid, 1,5-anthraquinone disulfonic acid, 2,6-anthraquinone disulfonic acid, anthraquinone sulfonic acid, 4-hydroxybenzenesulfonic acid, , And one kind selected from the group consisting of The water-soluble polymer is one kind selected from the group consisting of polymethacrylic acid, polyacrylic acid, polyvinyl alcohol, polyvinyl butylal, methylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, polyvinyl acetate, Wherein the water-dispersible carbon black is a water-dispersible carbon surface-modified with a sulfonate or a carboxylate. The antistatic coloring coating composition according to claim 1, wherein the mixed solvent comprises 94 to 99% by weight of an alcohol solvent and 1 to 6% by weight of an amide solvent. The antistatic colored coating composition according to claim 6, wherein the content of methanol is 50% by weight or more based on the total weight of the mixed solvent. (a) introducing an aqueous solution of polyethylene dioxythiophene into a reactor to start stirring; (b) continuously adding an alcohol and an amide-based mixed solvent, an alkoxysilane, a sulfonic acid monomer dopant, and a water-soluble polymer sequentially while stirring, and then stirring for 6 hours or more; (c) further adding water-dispersible carbon black and stirring the mixture for 2 hours or more. Characterized in that the composition of claim 1 is applied to the glass surface at a rate of 80 to 150 rpm over a period of 80 to 150 seconds by the spin method and then thermally fired at a temperature of 150 to 200 DEG C for 30 minutes to 1 hour. Way.