JPH0741705A - Production of antistatic transparent sheet - Google Patents

Abstract

PURPOSE:To improve the conductivity, scratch resistance, hardness, and tranparency of a transparent sheet by forming first and second conductive coating layers on one side of the sheet. CONSTITUTION:A first photocurable conductive coating compsn. is obtd. by compounding 100 pts.wt. (meth)acrylate compd. having at least two (meth) acryloyl groups in the molecule, 100-500 pts.wt. conductive powder which comprises tin oxide contg. Sb and having an average particle size 0.01-0.4mum comprises BaSO4 coated with tin oxide and having an average particle size of 0.1-2mum. and a photopolymn. initiator. A second photocurable conductive coating compsn. is prepd. by compounding 100 pts.wt. the (meth)acrylate compd., 0.5-5 pts.wt. acicular conductive powder having a length of 3-30mum and an aspect ratio of 3-150, and the initiator. The objective sheet is obtd. by applying the first coating compsn. to one side of a transparent sheet, irradiating the side with an active ray to cure the compsn. to form a first conductive layer with a thickness of 0.5-3mum, applying the second coating compsn. onto the first conductive layer, and irradiating with the actinic ray to form a second conductive layer with a thickness of 0.4-5mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to conductivity, scuff resistance,
The present invention relates to a method for producing an antistatic transparent sheet having excellent hardness and transparency.

[0002]

2. Description of the Related Art Conductive synthetic resin moldings are used for their properties such as semiconductor wafer storage containers, electronic / electrical members, floor materials and wall materials in semiconductor manufacturing factories. Conventionally, in order to impart conductivity to a synthetic resin molded body, the synthetic resin molded body is coated with a coating material containing carbon powder or metal powder, or carbon powder, carbon fiber, metal fiber or the like is kneaded into the synthetic resin. It is being molded in.

However, in these conventional methods, the coating film obtained and the synthetic resin molded product itself are colored, so that they are opaque and the contents cannot be seen through. There was a problem that I could not.
Further, the coating film and the synthetic resin molded product obtained by the above method have a problem that they are easily attacked by an organic solvent and have poor chemical resistance.

JP-A-60-60166 discloses a coating material comprising a conductive powder containing tin oxide as a main component and a photocurable coating binder containing a (meth) acryl oligomer having a (meth) acryloyl group as a main component. Is disclosed.
This paint forms a coating film having excellent conductivity, transparency and scuff resistance. However, when it is immersed in an organic solvent, there is a problem that the transparency is lowered and the chemical resistance is poor.

Further, Japanese Patent Application Laid-Open No. 62-170330 discloses a conductive plate in which coating films containing conductive fine powder containing tin oxide as a main component are laminated. However, when it is attempted to improve the conductivity of the resulting coating film, the scratch resistance of the coating film is reduced, and when it is attempted to improve the scratch resistance of the resulting coating film, the conductivity of the resulting coating film is reduced. The coating film having excellent conductivity and scuff resistance could not be obtained.

[0006]

An object of the present invention is to easily produce an antistatic transparent sheet which is electrically conductive and is excellent in transparency (total light transmittance), abrasion resistance, hardness and chemical resistance. To provide a possible method.

[0007]

The photocurable conductive coating material (A) used in the first step of the present invention comprises a (meth) acrylate compound, a conductive powder (a) or a conductive powder (b), and a light. It consists of a polymerization initiator.

The above-mentioned (meth) acrylate compound is a (meth) acrylate compound having two or more (meth) acryloyl groups in the molecule. Examples of such a (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di. (Meta)
Acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, nonapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 2,2-bis Bifunctional (meth) acrylate such as [4-((meth) acryloxydiethoxy) phenyl] propane, or pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, isocyanuric Tris ((meth) acryloxyethyl) acid trifunctional (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) ac Rate, 4 or more functional (meth) acrylates such as dipentaerythritol hexa (meth) acrylate.

Further, as a (meth) acrylate compound other than the above, an acrylic urethane oligomer having two or more (meth) acryloyl groups at the terminal of the molecule and having a urethane bond in the molecule can also be obtained as the first-layer conductive material. The coating film is excellent in abrasion resistance and suitable. Such an acrylic urethane oligomer is prepared, for example, by reacting a compound having two or more isocyanate groups in one molecule with a (meth) acrylate compound having active hydrogen.

Examples of the compound having two or more isocyanate groups in one molecule include m-phenylene diisocyanate, p-phenylene diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate and toluene-2. , 5-diisocyanate, toluene-3,5-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4 ′ -Diisocyanate-3,3'-dimethylbiphenyl, 4,4'-diisocyanate-3,3'-
Dimethylbiphenylmethane and the like can be mentioned.

Examples of the active hydrogen-containing (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, glycerin di (meth) acrylate and 1,6-bis (3-). Examples thereof include acryloxy-2-hydroxypropyl) -hexyl ether, pentaerythritol tri (meth) acrylate, (meth) acrylic acid and the like. The (meth) acrylate compounds may be used alone or in combination.

When a (meth) acrylate compound having one (meth) acryloyl group in the molecule is added,
The obtained first-layer conductive coating film is suitable because it imparts flexibility and toughness.

As the conductive powder, a conductive powder (a) made of tin oxide powder containing antimony, or
A conductive powder (b) made of barium sulfate coated with tin oxide containing antimony is used. When the average particle diameter of the conductive powder (a) is larger than 0.4 μm,
The conductive powder (a) scatters visible light, and the transparency (total light transmittance) of the obtained conductive coating film for the first layer is lowered.
When it is less than 0.01 μm, the conductivity of the obtained first-layer conductive coating film is lowered, the conductive powder (a) of the photocurable conductive coating material (A) is easily settled, and the coating material is gelled. Since it becomes easy, it is limited to 0.01 μm to 0.4 μm.

When the content of antimony is small, the conductivity of the first-layer conductive coating film obtained is low, and when it is large, the transparency (total light transmittance) of the first-layer conductive coating film obtained is low. Therefore, 0.1 to 20% by weight is preferable. Such a conductive powder (a) is available from Mitsubishi Materials Corporation under the trade name T-.
Sold for 1.

The average particle size of the conductive powder (b) is 0.1 μm.
When it is smaller than m, the transparency (total light transmittance) of the obtained first-layer conductive coating film decreases, and when it is larger than 2 μm, the smoothness of the surface of the first-layer conductive coating film decreases. It is limited to 0.1 μm to 2 μm. Such an electrically conductive powder (b) is sold by Mitsui Kinzoku Co., Ltd. under the trade name Pastran Type-IV.

The amount of the conductive powder added is limited to 100 to 500 parts by weight with respect to 100 parts by weight of the (meth) acrylate compound. When the amount is less than 100 parts by weight, the conductivity of the obtained first-layer conductive coating film decreases, and when it is more than 500 parts by weight, the transparency (total light transmittance) and the mechanical properties of the obtained first-layer conductive coating film Strength decreases.

The photopolymerization initiator is not particularly limited as long as it has a property of initiating the photopolymerization of the (meth) acrylate compound with an actinic ray such as an ultraviolet ray. For example, sodium dimethyldithiocarbamate, diphenyl monosulfide, dibenzothiazoyl monosulfide and sulfides; thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-
Thioxanthone derivatives such as diethylthioxanthone; azo compounds such as hydrazone and azobisisobutyronitrile; diazo compounds such as benzenediazonium salts; benzoin, benzoin methyl ether, benzoin ethyl ether, benzophenone, dimethylaminobenzophenone, Michler's ketone, benzylanthraquinone, t -Butylanthraquinone, 2-methylanthraquinone, 2-
Ethyl anthraquinone, 2-amino anthraquinone, 2
An aromatic carbonyl compound such as chloroanthraquinone;
Dialkylaminobenzoic acid esters such as methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate, butyl p-dimethylaminobenzoate and isopropyl p-diethylaminobenzoate; benzoyl peroxide, di-t-butyl peroxide, Peroxides such as dicumyl peroxide and cumene hydroperoxide; acridine derivatives such as 9-phenylacridine, 9-p-methoxyphenylacridine, 9-acetylaminoacridine and benzacridine; 9,10-dimethylbenzphenazine, 9 -Methylbenzphenazine, 10
-Phenazine derivatives such as methoxybenzphenazine;
^6,4,, 4 ^,, - trimethoxy-2,3-quinoxaline derivatives such as diphenyl quinoxaline; 2,4,5 triphenyl imidazolyl dimers, 2-nitrofluorene,
2,4,6-triphenylpyrylium tetrafluoride boron salt, 2,4,6-tris (trichloromethyl) -1,
3,5-triazine, 3,3, -carbonylbiscoumarin ^, thiomichler ketone and the like can be mentioned.

When the amount of the photopolymerization initiator added is small, the photopolymerization does not proceed completely, and the hardness and scuff resistance of the obtained first layer conductive coating film are lowered, and when the amount is large, the first layer obtained. Since the weather resistance of the conductive coating film decreases, it is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylate compound.

The photocurable conductive paint (A) used in the present invention comprises the above-mentioned (meth) acrylate compound, the conductive powder (a) or the conductive powder (b) and a photopolymerization initiator, but it is necessary. Accordingly, within a range that does not impair the physical properties, an organic solvent, a dispersant, a sensitizer, an ultraviolet absorber, a thermal polymerization inhibitor,
Antioxidants, surface modifiers, defoamers and the like may be added.

The above-mentioned organic solvent is added for adjusting the paint viscosity of the photocurable conductive paint (A). However, for those having a low boiling point, the organic solvent evaporates during coating and the paint viscosity changes. However, it becomes difficult to adjust the film thickness, and for those having a high boiling point, the drying step requires time.

Therefore, the organic solvent has a boiling point of 70 to 160 ° C.
Are preferred. Those containing oxygen due to the affinity with the conductive powder are particularly preferable.

Examples of the above organic solvent include cyclohexanone, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), diethylene glycol dimethyl ether, butyl acetate, isopropyl acetone, methyl ethyl ketone, anisole, etc. Or may be used in combination.

When the amount of the organic solvent added is small, the transparency (total light transmittance) of the first-layer conductive coating film obtained is lowered,
Also, if there is a large amount, the viscosity of the paint becomes low and the coatability deteriorates,
Since problems such as formation of only the first-layer conductive coating film thinner than the film thickness to be obtained occur, 200 to 2000 parts by weight is preferable with respect to 100 parts by weight of the (meth) acrylate compound.

The dispersant is added to improve the dispersibility of the conductive powder. Examples of the dispersant include oleic acid, acetic acid, (meth) acrylic acid, p-styrene sulfonic acid and the like. Organic acids, polyvinyl butyral, polyvinyl acetals such as polyacetoacetal (acetalized by condensation reaction of polyvinyl alcohol and acetaldehyde), copolymers of methyl methacrylate and 2-hydroxyethyl methacrylate, vinyl chloride and vinyl acetate Polymer compounds such as copolymers with and the like can be mentioned. The sensitizer is added to improve the sensitivity of the photopolymerization initiator. Examples of the sensitizer include dimethylaminoacetophenone, Michler's ketone, ethyl 2-dimethylaminobenzoate and p-dimethylaminobenzoate. Ethyl acid and the like can be mentioned.

The method for producing the photocurable conductive paint (A) is as follows:
Any method may be adopted, for example, the (meth) acrylate compound, the conductive powder and the photopolymerization initiator,
It is prepared by supplying to an attritor, a high-speed rotary stirring device, a dissolver, etc., and mixing and dispersing. When the dispersion time is long, the adhesion between the first-layer conductive coating film and the second-layer conductive coating film decreases, and when the dispersion time is short, the dispersibility of the conductive powder decreases, and the first-layer conductive coating film also decreases. Transparency of the conductive coating obtained by laminating the second layer conductive coating on top (total light transmittance)
Is decreased, so that 1 to 8 hours is preferable.

The transparent sheet used in the present invention also includes plates and films. Examples of the transparent sheet include a synthetic resin sheet made of polyvinyl chloride, polycarbonate, polymethacrylate, acrylic resin, ABS resin, etc., a synthetic resin plate, and a synthetic resin film. Further, it may be an inorganic substance such as glass.

In the first step of the present invention, the above-mentioned photocurable conductive coating material (A) is applied to one surface of the transparent sheet, and then irradiated with actinic rays to be cured to form a first layer conductive coating film. This is a step of obtaining a laminated body.

The method for applying the photocurable conductive coating material (A) on one surface of the transparent sheet is not particularly limited, and a general application method is used. For example, spray method, roll coater method, bar coat method, doctor blade method,
Examples include dipping method. After applying the photocurable conductive paint (A) on one surface of the transparent sheet, if an organic solvent is added, it is dried with hot air, infrared rays, etc., and then irradiated with actinic rays using a high pressure mercury lamp or a metal halide lamp. And cured to form a first-layer conductive coating film.

When the thickness of the first-layer conductive coating film is thin, the conductivity and scuff resistance of the first-layer conductive coating film obtained are lowered,
Further, if it is thick, the transparency (total light transmittance) of the obtained conductive coating film for the first layer is lowered, so 0.5 to 3 μm is preferable.
When the irradiation amount of actinic rays is small, the curing of the first-layer conductive coating film becomes insufficient, and the abrasion resistance, hardness and adhesion to the transparent sheet of the obtained first-layer conductive coating film decrease, and And the first-layer conductive coating film is colored, and the adhesion between the first-layer conductive coating film and the second-layer conductive coating film is deteriorated, so that the integrated exposure amount is 100 to 2000 mJ / cm ^2. It is preferable to irradiate active light so that

The photocurable conductive coating material (B) used in the second step of the present invention comprises a (meth) acrylate compound, a needle-shaped conductive powder (c) and a photopolymerization initiator. As the (meth) acrylate compound and the photopolymerization initiator, the same ones as those used in the photocurable conductive paint (A) are used.

The needle-shaped conductive powder (c) is not particularly limited as long as it is a needle-shaped conductive powder having an average length of 3 to 30 μm and an aspect ratio of 3 to 150. For example, needle-shaped potassium titanate coated with tin oxide containing antimony and its reducing compound, needle-shaped titanium oxide coated with tin oxide containing antimony, needle-shaped potassium titanate There are reducing compounds, needle-like carbon fibers and the like.

The average length of the conductive powder (c) is 3 to 3.
Limited to 0 μm. If it is longer than 30 μm, the dispersibility of the conductive powder (c) is lowered, and the transparency (total light transmittance) of the obtained conductive coating film is lowered, and if it is shorter than 3 μm, the conductive coating film obtained is obtained. Conductivity is reduced. The conductive powder (c) has an Akpest ratio limited to 3 to 150. When it is larger than 150, the dispersibility of the conductive powder (c) is lowered, and the transparency (total light transmittance) of the obtained conductive coating film is lowered, and when it is smaller than 3, the conductivity of the obtained conductive coating film is reduced. Sex decreases.

The conductive powder (c) is added in an amount of 0.5 with respect to 100 parts by weight of the (meth) acrylate compound.
Limited to ~ 5 parts by weight. If it is more than 5 parts by weight, the transparency (total light transmittance) of the obtained conductive coating film is lowered, and
If the amount is less than 5 parts by weight, the electroconductivity of the electroconductive coating film obtained will decrease.

The photocurable conductive paint (B) comprises the above-mentioned (meth) acrylate compound, the conductive powder (c) and a photopolymerization initiator. Similar to the curable conductive paint (A), an organic solvent, a dispersant, a sensitizer, an ultraviolet absorber, a thermal polymerization inhibitor, an antioxidant, a surface modifier, a defoaming agent, etc. may be added. .

The photocurable conductive paint (B) is prepared in the same manner as the photocurable conductive paint (A). The longer the dispersion time is, the longer the needle-shaped conductive powder (c) is broken, and the lower the conductivity of the resulting conductive coating film is. In the second step of the present invention, the photo-curable conductive coating material (B) is applied on the first-layer conductive coating film, followed by irradiating with actinic rays to cure the second-layer coating on the first-layer conductive coating film. It is a step of obtaining an antistatic transparent sheet in which a layer conductive coating film is laminated.

As the method of applying the photocurable conductive coating material (B) and irradiating it with an actinic ray to cure it, the same method as in the first step is used. If the cumulative exposure dose of actinic rays is too small, curing will be insufficient, and the abrasion resistance and hardness of the resulting second-layer conductive coating film will be reduced.
² or more is preferable. When the thickness of the second-layer conductive coating film is thick, transparency (total light transmittance) and conductivity are reduced, and when it is thin, abrasion resistance and chemical resistance are reduced, and therefore 0.4 to 5 μm.
Is preferred.

[0037]

EXAMPLES Examples of the present invention will be described below. (Example 1) 50 parts by weight of pentaerythritol tetraacrylate, 50 parts by weight of urethane acrylate (trade name: UA-306T, manufactured by Kyoeisha Oil and Fat Co., Ltd.), tin oxide powder containing antimony and having an average particle diameter of 0.02 μm. Powder (Mitsubishi material company trade name T-1) 35
0 parts by weight, degree of acetalization with butyraldehyde 64
%, Ratio of residual hydroxyl groups to all hydroxyl groups 35%, ratio of acetyl groups to all hydroxyl groups 1%, average degree of polymerization 1700
30 parts by weight of polyvinyl butyral, thioxanthone 2
Parts by weight, 2 parts by weight of dimethylaminoacetophenone, 0.1 parts by weight of hydroquinone and 500 parts by weight of ethyl cellosolve were supplied to an attritor and dispersed for 6 hours to obtain a photocurable conductive coating material (A).

The photocurable conductive coating material (A) obtained above
Was applied to one surface of a 3 mm-thick acrylic resin plate so that the thickness of the dried first-layer conductive coating film would be 1.0 μm, and was dried with hot air at 50 ° C. for 10 minutes. Then, using a high-pressure mercury lamp, the total exposure of actinic rays is 1000 m.
Irradiate with actinic rays so that it becomes J / cm ² , cure,
A laminated body was obtained.

Next, 50 parts by weight of trimethylolpropane triacrylate, 50 parts by weight of urethane acrylate (trade name: UA-306T, manufactured by Kyoeisha Oil and Fat Co., Ltd.), and an average length of 1 coated with tin oxide containing antimony.
2 parts by weight of needle-shaped titanium oxide (trade name: Dentol WK-200 manufactured by Otsuka Chemical Co., Ltd.) of 5 μm and aspect ratio of 50, 1 part by weight of benzophenone, 2 parts by weight of dimethylaminoacetophenone, and 200 parts by weight of ethyl cellosolve were supplied to the dissolver. Dispersion was carried out for 30 minutes to obtain a photocurable conductive paint (B).

The photocurable conductive coating composition (B) thus obtained was applied onto the first-layer conductive coating film so that the thickness of the dried second-layer conductive coating film would be 1.5 μm. In the same manner as in the case of the photocurable conductive coating (A), drying and irradiating with actinic rays,
After curing, an antistatic transparent sheet having a conductive coating film was obtained.

The transparency, conductivity, scuff resistance and chemical resistance of the obtained laminate and antistatic transparent sheet were measured by the following methods, and the results are shown in Tables 1 and 2. (Transparency) ASTM-D100 for total light transmittance and haze value
It measured according to 3. (Conductivity) Specific surface resistivity was measured according to ASTM-D257. (Scratch resistance) A haze value and a surface specific resistance value were measured after a Taber abrasion test (using a CS-10 abrasion wheel, 100 cycles under a load of 500 g) according to ASTM-1044. (Chemical resistance) The haze value was measured after immersion in methanol, acetone, and a 30 wt% sodium hydroxide aqueous solution for 24 hours.

(Example 2) 250 parts by weight of dipentaerythritol hexaacrylate 100 parts by weight of tin oxide powder containing antimony, a conductive powder (trade name T-1 manufactured by Mitsubishi Materials) having an average particle size of 0.02 μm. Parts by weight, degree of acetalization with acetaldehyde 68%, ratio of residual hydroxyl groups to all hydroxyl groups 31%, ratio of acetyl groups to all hydroxyl groups 1%, average degree of polymerization 2400 polyacetoacetal (polycondensed alcohol and acetaldehyde 15 parts by weight of an acetalized product, 1 part by weight of thioxanthone, 3 parts by weight of ethyl 2-dimethylaminobenzoate, 0.1 part by weight of hydroquinone, and 500 parts by weight of cyclohexanone were supplied to an attritor, and
After time-dispersing, a photocurable conductive coating material (A) was obtained.

Using the obtained photocurable conductive coating material (A), a laminate was obtained in the same manner as in Example 1. Next, 50 parts by weight of trimethylolpropane triacrylate and urethane acrylate (trade name UA-30 manufactured by Kyoeisha Yushi Co., Ltd.)
6T) 50 parts by weight, coated with tin oxide containing antimony, average length 15 μm, aspect ratio 5
0 parts of needle-shaped potassium titanate reducing compound (trade name: Dentor BK-200 manufactured by Otsuka Chemical Co., Ltd.) of 0, 1 part by weight of benzophenone, 2 parts by weight of dimethylaminoacetophenone, and 200 parts by weight of cyclohexanone were supplied to the dissolver, and 30 It was dispersed for a minute to obtain a photocurable conductive coating material (B).

An antistatic transparent sheet was obtained in the same manner as in Example 1 by using the obtained photocurable conductive coating material (B). The transparency, conductivity, scratch resistance, and chemical resistance of the obtained antistatic transparent sheet were measured by the same methods as in Example 1, and the results are shown in Tables 1 and 2.

(Comparative Example 1) A laminate was obtained in the same manner as in Example 1 except that the photocurable conductive coating material (A) obtained in Example 1 was used. Next, 50 parts by weight of trimethylol propane triacrylate, 50 parts by weight of urethane acrylate (trade name UA-306T manufactured by Kyoeisha Yushi Co., Ltd.), and tin oxide powder containing antimony, having an average particle diameter of 0.02 μm.
m conductive powder (trade name T-1 manufactured by Mitsubishi Materials Corp.)
2 parts by weight, 1 part by weight of benzophenone, 2 parts by weight of dimethylaminoacetophenone, and 200 parts by weight of ethyl cellosolve were supplied to an attritor and dispersed for 12 hours to obtain a photocurable conductive coating material (B).

An antistatic transparent sheet was obtained in the same manner as in Example 1 except that the obtained photocurable conductive coating material (B) was used. The transparency, conductivity, scratch resistance, and chemical resistance of the obtained antistatic transparent sheet were measured by the same methods as in Example 1, and the results are shown in Tables 1 and 2.

Example 3 100 parts by weight of dipentaerythritol hexaacrylate, 0.2 part by weight of hydroquinone, 4 parts by weight of 2,4-diethylthioxanthone, 4 parts by weight of ethyl p-dimethylaminobenzoate and 780 parts by weight of ethyl cellosolve. And added it to the attritor. Then, with stirring, 300 parts by weight of a conductive powder (Pastlan Type-IV, trade name, manufactured by Mitsui Kinzoku Co., Ltd.) made of barium sulfate having an average particle size of 0.2 μm, which is further coated with tin oxide containing antimony. And ratio of residual hydroxyl groups to all hydroxyl groups 35%, average degree of polymerization 240
0 polyacetoacetal was supplied and dispersed for 10 hours,
A photocurable conductive coating material (A) was obtained.

The photocurable conductive coating composition (A) thus obtained was applied except that the first layer conductive coating film had a thickness of 4 μm.
A laminate was obtained in the same manner as in Example 1. Next, the photocurable conductive coating material (B) used in Example 1 was applied on the first layer conductive coating film so that the film thickness of the second layer conductive coating film was 4.5 μm. An antistatic transparent sheet was obtained in the same manner as in Example 1 except for the above. The transparency, conductivity, scuff resistance and chemical resistance of the obtained laminate and antistatic transparent sheet were measured by the same methods as in Example 1, and the results are shown in Tables 3 and 4.

Example 4 100 parts by weight of pentaerythritol triacrylate, 0.2 part by weight of hydroquinone,
4 parts by weight of 2,4-diethylthioxanthone and 4 parts by weight of ethyl p-dimethylaminobenzoate were added to cyclohexanone 1
It was added to 400 parts by weight and supplied to an attritor. Then, while stirring, 400 parts by weight of a conductive powder (Pastran Type-IV, trade name, manufactured by Mitsui Kinzoku Co., Ltd.) made of barium sulfate having an average particle size of 0.2 μm, which is further coated with tin oxide containing antimony. And ratio of residual hydroxyl groups to all hydroxyl groups 35%, average degree of polymerization 240
0 polyacetoacetal was supplied and dispersed for 10 hours,
A photocurable conductive coating material (A) was obtained.

A laminate was obtained in the same manner as in Example 3 by using the obtained photocurable conductive coating material (A). Next, an antistatic transparent sheet was obtained in the same manner as in Example 3 using the photocurable conductive coating material (B) used in Example 2. The transparency, conductivity, scratch resistance, and chemical resistance of the obtained antistatic transparent sheet were measured by the same methods as in Example 1, and the results are shown in Tables 3 and 4.

(Comparative Example 2) A laminate was obtained in the same manner as in Example 3 except that the photocurable conductive coating material (A) obtained in Example 3 was used. Next, 50 parts by weight of trimethylol propane triacrylate, 50 parts by weight of urethane acrylate (trade name UA-306T manufactured by Kyoeisha Yushi Co., Ltd.), and tin oxide powder containing antimony, having an average particle diameter of 0.02 μm.
m conductive powder (trade name T-1 manufactured by Mitsubishi Materials Corp.)
2 parts by weight, 1 part by weight of benzophenone, 2 parts by weight of dimethylaminoacetophenone, and 200 parts by weight of ethyl cellosolve were supplied to an attritor and dispersed for 12 hours to obtain a photocurable conductive coating material (B).

An antistatic transparent sheet was obtained in the same manner as in Example 3 except that the obtained photocurable conductive coating material (B) was used. The transparency, conductivity, scratch resistance, and chemical resistance of the obtained antistatic transparent sheet were measured by the same methods as in Example 1, and the results are shown in Tables 3 and 4.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

The structure of the method for producing an antistatic transparent sheet of the present invention is as described above, and the obtained antistatic transparent sheet has conductivity, transparency (total light transmittance) and abrasion resistance. Since it has excellent properties and chemical resistance, it can be suitably used for applications such as equipment covers in clean rooms where high antistatic properties, abrasion resistance and chemical resistance are required.

Claims (1)

[Claims] 1. A transparent sheet having one surface coated with a photocurable conductive coating material (A) and then irradiated with actinic rays to be cured to obtain a laminate having a first layer conductive coating film formed thereon. After applying the step and the photocurable conductive coating material (B) on the first layer conductive coating film,
A method for producing an antistatic transparent sheet, which comprises the second step of obtaining an antistatic transparent sheet by irradiating an actinic ray and curing the same to obtain a second layer conductive coating film laminated on the first layer conductive coating film. Then, the photocurable conductive coating material (A) is composed of 100 parts by weight of a (meth) acrylate compound having two or more (meth) acryloyl groups in the molecule, a tin oxide powder containing antimony, and an average particle diameter. The average particle size of the conductive powder (a) is 0.01 to 0.4 μm, or barium sulfate coated with tin oxide containing antimony has an average particle size of 0.
A photocurable conductive coating material (B) comprising 100 to 500 parts by weight of a conductive powder (b) of 1 to 2 μm and a photopolymerization initiator.
Is 100 parts by weight of a (meth) acrylate compound having two or more (meth) acryloyl groups in the molecule and a length of 3 to
A process for producing an antistatic transparent sheet, which comprises 30 to 5 parts by weight of a needle-shaped conductive powder (c) having an aspect ratio of 3 to 150 (c) and a photopolymerization initiator.