JPH0249075A - Antistatic paint composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of imparting excellent antistaticity to an article simply by coating and suitable as an electric field attenuation paint, antistatic paint and secondary electron emission paint by mixing a heteropoly acid to a coating substrate containing a film-forming resin as a vehicle. CONSTITUTION:The objective composition is produced by mixing (A) a coating substrate containing 100 pts.wt. of a film-forming resin as a vehicle with (B) 0.5-100 pts.wt. (preferably 1-50 pts.wt.) of a heteropoly acid [preferably a composite oxyacid of (i) at least one kind of element selected from B, Al, Ga, Si, Ge, Ce, Ti, Zr, Sb, Bi, Rh, Cu, Pt, P, Fe, Co and Ni and (ii) at least one kind of element selected from Mo, W and V].

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an antistatic coating composition for imparting antistatic properties to articles. More specifically, it relates to paint compositions that have an antistatic function, such as electric field relaxation paints, antistatic paints, and secondary electron emission paints, which are made by mixing a specific conductive inorganic material with a paint base material. The materials obtained by applying the coating composition to fibers, films, molded plates, etc. of plastics, rubber, metals, glass, ceramics, etc., can be used as elements related to electronic devices that control charge, current, voltage, resistance value, etc. Industrially useful.

(Prior art) Conventionally, in order to impart antistatic properties to articles, antistatic fillers have been mixed and dispersed in articles, or antistatic fillers have been mixed and dispersed in paint base materials. Techniques for applying paint to articles are well known. Among these, antistatic paints tend to be preferred because they have a degree of flexibility in the objects they can be applied to and the desired antistatic properties can be obtained with a small amount. Examples of vIN fillers include carbon fillers such as carbon black and carbon fiber, gold layer fillers such as metal powder and metal fibers, carbide fillers such as silicon carbide and tungsten carbide, and fillers such as tin oxide and indium oxide. Metal oxide fillers have been used because of their excellent conductivity.

However, these antistatic fillers have non-uniform conductivity due to irregularities in shape and composition, and even when there is no irregularity in shape or composition, they have poor dispersibility in paints. There were problems such as non-uniform conductivity in the paint film and poor stability over time in the paint. Furthermore, there are problems in that it is necessary to add a large amount of antistatic filler in order to obtain the desired antistatic properties, and the color tone of the coating film is also limited.

Furthermore, antistatic paints containing surfactants such as quaternary ammonium salts are also known. However, there are problems in that unless a large amount of surfactant is blended, there is no effect of imparting antistatic properties, the surface of the resulting coating film becomes sticky, and the effect decreases when washed with water.

(Problem to be Solved by the Invention) The present inventors have discovered that when a heteropolyacid is mixed into a paint, uniform antistatic properties can be imparted to the paint film with the addition of a relatively small amount of the heteropolyacid. , which led to the present invention.

(Means and Effects for Solving the Problems) The present invention provides a paint base material containing a film-forming resin as a vehicle, and a heteropolyacid of 0.5 to 100 to 1 weight per 100 parts of the film-forming resin.
The present invention relates to an antistatic coating composition characterized in that it is mixed at a ratio of 100 parts by weight.

The heteropolyacid that can be used in the present invention includes an element (hereinafter referred to as a group A element) that can play a central role in its crystal structure.

), and an element (hereinafter referred to as a B-group element) capable of forming a composite oxy-acid with an oxy-acid of a group A element, such as the heteropolyacids shown in Tables 1 to 3 below.

Table 1 (When the B group element is molybdenum) Table 2 (B
(When the group element is tungsten) Such heteropolyacids are generally obtained in a form with a unique water of crystallization depending on the types and ratios of the constituent group A and B elements, and the manufacturing method. In this case, depending on the drying conditions, it can be obtained with any amount of water of crystallization below the characteristic value.

Table 3 (when there are multiple BFJ elements) It is.

As a method for synthesizing a heteropolyacid, a known method can be employed. For example, phosphotungstic acid, which is a typical heteropolyacid, can be synthesized by reacting phosphate ions and tungstate ions under acidic conditions. As a method for synthesizing other heteropolyacids, for example, the method described in the paper by Sasaki et al., published in Journal of the Japan Society of Synthesis, 127 (1975), can be applied.

The antistatic coating composition of the present invention is obtained by mixing the above-mentioned heteropolyacid with a paint base material using a film-forming resin as a vehicle. : Or heteropolyacid is water, alcohol,
A state in which a heteropolyacid is uniformly dissolved in a solvent containing ethers, ketones, carboxylic acids, esters, etc.;
The state in which it is supported or impregnated on inorganic fine particles such as silicon carbide and heteropolyacid salts, or organic fine particles such as polystyrene, nylon, and poly(meth)acrylate can be freely selected.

In addition, when using a heteropolyacid dissolved in the above-mentioned solvent, there is no problem even if it forms an adduct with the solvent.

In addition, when heteropolyacids are mixed with paint base materials, they may form adducts with film-forming resins, solvents, and various additives contained in the base materials, or may partially form adducts with metal ions or organic basic compounds. may form salts,
There is no particular problem.

As a method for mixing the above-mentioned heteropolyacid into a paint base material, a conventionally known paint preparation method in which pigments and fillers are mixed into a paint base material may be followed. For example, the paint base material and the above-mentioned heteropolyacid powder, solution, or carrier may be put into a mixer such as a paint shaker or a ball mill, or a mixer such as a kneader or roll and mixed together. The order of addition is arbitrary; for example, the heteropolyacid may be mixed with a small amount of a paint base material to form a paste, and this may be diluted with a predetermined amount of a paint base material to obtain the paint composition of the present invention.

The mixing ratio of the heteropolyacid to the coating material is 0.5 to 100 parts by weight based on 100 parts by weight of the film-forming resin as a vehicle.
100 ffiffi parts, preferably in the range of 1 to 50 parts by weight. If this proportion is less than 0.5 parts by weight, the effect of imparting antistatic properties to articles of the resulting coating composition will be insufficient. Further, if the amount exceeds 100 parts by weight, not only the antistatic property imparting effect will not be improved but also the mechanical strength of the coating film obtained by applying the resulting coating composition to an article will decrease.

The film-forming resin used as a vehicle in the antistatic coating composition of the present invention is a vine resin that forms a film when applied to an article, and has conventionally been used as a vehicle by being blended with a paint base material. For example, (meth)acrylic, vinyl, cellulose, epoxy, phenol, melamine, urea, polyester, alkyd, urethane, amino, amide, imide. , silicone-based, rubber-based synthetic resins, and natural resins.

Among these, resins having a hydrophilic functional group in the molecule that interacts with heteropolyacids are preferred. Examples of such functional groups include hydroxyl groups, epoxy groups, carboxyl groups and their metal salts and ammonium salts, carbonylol groups, silanol groups, halogen groups, urethane groups, mercapto groups, amino groups, amide groups, etc. .

In addition, in order to promote film formation of the film-forming resin, various dispersion media such as a solvent for dissolving the resin and water for dispersing the resin may be blended into the paint base material. ,
Generally, the film-forming resin is mixed with the heteropolyacid in the form of an organic solvent solution or an aqueous dispersion.

In the present invention, when mixing a heteropolyacid into a paint base material, carbon fillers such as carbon black and carbon fiber, which have been conventionally used in antistatic paints, and metal fillers such as metal powder and metal fibers are used. , carbide fillers such as silicon carbide and tungsten carbide, metal oxide fillers such as tin oxide and indium oxide, antistatic fillers such as heteropolyacid salt fine particles, and heteropolyacid salts or interfaces that can be dissolved in paint base materials. An activator or the like can also be used in combination.

In order to form an antistatic coating on an article using the antistatic coating composition of the present invention, the coating composition is applied to articles of various shapes such as fibers, films, and molded plates, and then dried if necessary.
Post-processing such as heating and light irradiation is performed. As for the application method,
For example, conventionally known methods such as spraying, dipping, roll coater, knife coater spin coater, and coating can be used.

The material of the article to which the antistatic coating composition of the present invention is applied is not particularly limited, and examples include polyethylene, polypropylene, polystyrene, polyvinyl chloride,
Plastics such as polycarbonate, polymethyl methacrylate, phenolic resin, melamine resin, urea resin, epoxy resin, unsaturated and saturated polyester resin, ABS resin, polyamide resin, polyimide resin; natural rubber, SBR rubber, silicone rubber, polyurethane rubber, etc. Rubbers; Metals such as diferrous metal, aluminum, and stainless steel; Glasses such as soda glass and Pyrex glass; Zirconia;
Examples include ceramics such as titania, alumina, silica, silicon carbide, and silicon nitride.

(Effects of the Invention) The antistatic coating composition of the present invention, which is formed by mixing a heteropolyacid into a paint base material, can be applied to an article even if the amount of the heteropolyacid in the composition is relatively small. It is possible to impart remarkable antistatic properties to articles simply by applying it to the surface.

Furthermore, since the antistatic coating composition of the present invention has excellent uniformity in electrical properties such as conductivity of the obtained coating film, it is suitable as a coating material for creating a υ1m element such as charge, current, voltage, and resistance value. For example, it is also suitable as an electric field relaxation paint, an antistatic paint, a secondary electron emission paint, etc.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples, but the scope of the present invention is not limited in any way by these Examples.

Example 1 Phosphormolybdic acid (+-+3 PMotzO4o・29
30 weight 11 parts of powder of H20) was mixed with Aloron 50 (medium oil based alkyd resin, resin solid content 50%, Nippon Shokubai Chemical Co., Ltd.)
Add to 200 parts a of
The mixture was mixed for a minute to form an antistatic paint.

This antistatic paint was applied to a polyethylene terephthalate film using the doctor blade method, resulting in a coating thickness of 5 μm after drying.
It was applied so that

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 4.

Example 2 Phosphortungstic acid (H3PW1204o・29HzO
) was added to 240 parts by weight of Acryset 270E (acrylic emulsion, resin solid content 42%, manufactured by Nippon Shokubai Chemical Co., Ltd.), and the mixture was mixed with a paint shaker for 30 parts by weight.
The mixture was mixed for 0 minutes to obtain a tA electrical paint. This antistatic coating material was applied to a polyethylene terephthalate film by a doctor blade method so that the coating thickness after drying was 5 μm.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 4.

Example 3 Keimolybdic acid (H4SiMOT204o・30H2
0) was mixed with Aloron 4500 (epoxy modified resin, resin solid content 50%, manufactured by Nippon Shokubai Chemical Co., Ltd.) 2
00 parts by weight and mixed for 30 minutes using a paint shaker to form an antistatic paint. This antistatic paint was applied to a Bakelite molded plate using a bar coater so that the coating thickness after drying was 5 μm.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 4.

Example 4 Silicon tungsten M (H4SiWt204o/30H2
0) powder was added to 70 Ron 76 (acrylic resin,
The mixture was added to 200 parts by weight of resin (solid content 50%, manufactured by Nippon Shokubai Kagaku Kogyo ■) and mixed for 30 minutes using a paint shaker to obtain an antistatic paint. This antistatic paint was applied to a chloroprene rubber sheet using a bar coater until the coating thickness after drying was 5.
It was applied so that it was μ.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 4.

Example 5 In Example 2, phosphotungsten Wl (H3PW
t20 Tochi・29H20) amount 0,1.2.30゜50
An antistatic paint was produced in the same manner except that the amount was changed to 100 parts by weight. These antistatic paints were applied to a polyethylene terephthalate film in the same manner as in Example 2, and the surface resistance values thereof were measured. Table 5 shows the results.

As is clear from the results in Table 5, when the amount of phosphotungstic acid was 0.1 parts by weight, the conductivity of the coating film was insufficient.

Example 6 In Example 2, the antistatic paint was applied onto a polyethylene terephthalate film, and the change in surface resistance value depending on the temperature was measured. The results are shown in Table 6.

Table 6 Example 7 In Example 2, the antistatic paint was applied onto a polyethylene terephthalate film, and the change in surface resistance value due to humidity was measured. The results are shown in Table 7.

Table 7 Example M 8 Phosphormolybdic acid (+3 PMo1204o・29H2
0) was dissolved in 50 parts by weight of ion-converted water, mH of water was dissolved in 333 parts by weight of Acryset 188 Days (acrylic emulsimin, resin solid content 30%, manufactured by Nippon Shokubai Chemical Co., Ltd.). and mixed with a paint shaker for 30 minutes to obtain an antistatic paint. This antistatic coating material was applied to a polyethylene terephthalate film by a doctor blade method so that the coating thickness after drying was 5 μm.

The surface paper F'LlIlI of the obtained coating film was heated to 50% at 20°C.
Table 8 shows the results when measured at RH.

Example 9 Phosphorous tungsten II (To13PW1204o/29)
A solution obtained by dissolving 2 Ojl parts of powder of +20> in 20 parts by weight of methanol was added to 200 multilayer parts of Aloron 453 (acrylic resin, resin solid content 50%, manufactured by Nippon Shokubai Chemical Co., Ltd.), and mixed with a paint shaker. The mixture was mixed for 30 minutes to obtain an antistatic paint. This antistatic coating material was applied to a polyethylene terephthalate film by a doctor blade method so that the coating thickness after drying was 5 μm.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 8.

Example 10 Silicon tungsten Fa (H4S i W1204o・
An aqueous solution obtained by dissolving 0.16 parts of sodium carbonate in 10 parts by weight of ion-exchanged water was slowly added to an aqueous solution obtained by dissolving 10 parts by weight of powder of 30H20) in 30 parts by weight of ion-exchanged water. .

The aqueous solution of partially neutralized silicotungstic acid thus obtained was added to Acryset 262E (acrylic emulsion, resin solid content 37%, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) 270 Juyama 1, and mixed for 30 minutes with a paint shaker.
It was made into an antistatic paint. This fern qualitative paint was applied to a sheet made of black-o-blen rubber using a bar coater so that the coating thickness after drying was 5 μm.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 8.

Example 11 Keitungsten! ! (Ha Si W1204o
・Slowly add an aqueous solution obtained by dissolving 0.22 parts by weight of lithium carbonate in 10 parts by weight of ion-exchanged water to an aqueous solution obtained by dissolving 10 parts by weight of powder of 30H20) in 30 parts by weight of ion-exchanged water. After that, the mixture was heated and concentrated to obtain a white powder of partially neutralized silicotungstic acid.

This powder was added to 200 parts by weight of Aloron 376 (medium oil based alkyd resin, resin solid content 50%, manufactured by Nippon Shokubai Chemical Co., Ltd.) and mixed for 30 minutes in a paint shaker to obtain an antistatic paint. This antistatic paint was applied to a Bakelite molded plate using a bar coater so that the coating thickness after drying was 5 μm.

The surface resistance values of the resulting coating films were measured at 20° C. and 50% RH, and the results are shown in Table 8.

Claims (2)

[Claims] (1) An antistatic method characterized by mixing a heteropolyacid in a paint base material containing a film-forming resin as a vehicle in a ratio ranging from 0.5 to 100 parts by weight per 100 parts by weight of the film-forming resin. paint composition. (2) The antistatic coating composition according to claim 1, wherein the heteropolyacid is a composite oxygen acid of at least one element selected from the following Group A and at least one element selected from the following Group B. thing. (Note) Group A: boron, aluminum, gallium, silicon, germanium, cerium, titanium, zircon, antimony,
Bismuth, rhodium, copper, platinum, phosphorus, iron, cobalt and nickel Group B: molybdenum, tungsten and vanadium