JPS60181172A - Antistatic transparent coating compound - Google Patents

Abstract

PURPOSE:The titled transparent coating compound useful for electronic and electric members, having improved antistatic properties, obtained by blending a hydroxy group-containing copolymer comprising hydroxyl group-containing vinyl monomer, vinyl chloride monomer, etc. with electrically-conductive powder having an electrically-conductive layer of tin oxide and specific particle diameters in a specific ratio. CONSTITUTION:(A) 100pts.wt. hydroxyl group-containing copolymer comprising (i) 2-20mol% hydroxyl group-containing vinyl monomer [e.g., hydroxyethyl (meth)acrylate, etc.], (ii) 80-98mol% vinyl chloride monomer, and (iii) 0-18 mol% another polymerizable monomer (e.g., styrene, etc.) is blended with 100- 350pts.wt. electrically-conductive powder comprising tin oxide as a main component, having <-0.2mum particle diameters, to give the desired coating compound. EFFECT:Forming a film having improved chemical resistance and durability. USE:For containers for semiconductor wafer, clean benches, floor covering materials and wall materials for semiconductor preparation plant, etc.

Description

[Detailed description of the invention] il+ Industrial application field IJ1 from scratch can form a transparent coating for antistatic purposes, specifically a coating film that has excellent antistatic properties and excellent chemical resistance and durability. Regarding M-mei paint.

(2) Conventional technology Containers for semiconductor quefers, clean benches, clean rooms, other electronic/electrical parts, flooring materials for semiconductor manufacturing factories, etc.
Wall materials and the like are often required to have antistatic properties. Conventionally, such members have been coated with a conductive paint containing carbon black to impart conductivity.

However, this method had drawbacks such as the paint film being colored black or a dark color close to black and opaque, and carbon black falling off from the paint film due to surface friction. On the other hand, Japanese Unexamined Patent Publication No. 111357-85866 discloses an antistatic transparent paint containing conductive fine powder containing tin oxide as a main component. This paint has the disadvantage that it is difficult to disperse the conductive fine powder to a high degree, and therefore it is difficult for the paint film obtained by coating the resin member to stably exhibit transparency and antistatic properties over a long period of time. be.

(3) Purpose of the invention The purpose of the present invention is to have excellent antistatic effect! Our objective is to provide paints that can be used for various purposes. Another object of the present invention is to provide a coating material that can form a coating film with excellent chemical resistance and durability.

(4) Structure of the Invention Summary of the Invention Hydroxyl group containing 2 to 20 mol% of hydroxyl group-containing vinyl monomer, 80 to 98 mol% of vinyl chloride monomer, and -0 to 18 mol% of other polymerizable monomers Containing copolymer 1
0.00 part by weight, particle size 0.2 with tin oxide as the main component
The invention relates to a transparent coating for antistatic use, characterized in that it contains 100 to 350 parts by weight of conductive fine powder with a diameter of less than 1 m.

The above-mentioned hydroxyl group-containing copolymer is used as a binder in the coating material of the present invention, and the above-mentioned monomers can be co-polymerized by ordinary polymerization methods such as solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization. Although it is often a polymer, it may also be a copolymer compound.

Specific examples of the hydroxyl group-containing vinyl monomer that is a component of this copolymer include hydroxyethyl (meth)acrylate (this refers to both hydroxyethyl acrylate and hydroxyethyl methacrylate; hereinafter the same 0), hydroxypropyl Hydroxyalkyl (meth)acrylates such as (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyoctyl (meth)acrylate, and the number of repeats of the ether bond moiety is 2 or more.
Examples include polyethylene glycol mono(meth)acrylate having a carbon content of about 9, polypropylene glycol mono(meth)acrylate having a repeating number of ether bonding moieties of about 2 to 6, and vinyl alcohol.

Among these specific examples, hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate are used. If the amount of the hydroxyl group-containing monomer used in the above copolymer is too small, it will not be possible to uniformly disperse the conductive fine powder, making it difficult to obtain a coating film with good transparency and smoothness. If the amount is too large, the chemical resistance of the resulting coating film decreases, so the amount is set at 2 to 20 mol %, and is preferably used in the range of 5 to 15 mol %.

Vinyl chloride, which accounts for most of the hydroxyl group-containing copolymer component, is necessary to form a coating film with excellent chemical resistance, and is 80 to 98 mol%, preferably 85% by mole in the copolymer.
It is used in a range of 95 mol%.

In addition to vinyl chloride and hydroxyl group-containing vinyl monomers, the hydroxyl group-containing copolymer may also contain other vinyl monomers such as styrene, vinyl acetate, esters of acrylic acid or methacrylic acid having hydroxyl groups, and olefins. 0-18
It is good even if used within the mol% range.

The conductive fine powder used in the paint of the present invention contains tin oxide as a sensitizing component or main component, and may contain, for example, a small amount of antimony to further enhance conductivity.
Probably because the particle size is 0.0mm in order to form a transparent coating film.
Less than 27 m, preferably less than t-to, iμm. In order to have good antistatic ability, it is desirable that the surface resistivity is 10"Ω10 or less, and therefore the amount of the conductive fine powder is 100 parts by weight per 100 parts by weight of the hydroxyl group-containing copolymer. The above is necessary, and preferably Fi
It is said to be 120 parts by weight or more. In addition, if the amount of the conductive powder is too large, the dispersion will be poor and a coating film with good transparency and smoothness will not be obtained.
It is used in a range of 50 parts by weight or less, preferably 300 parts by weight or less.

The coating material of the present invention is prepared, for example, by dissolving the copolymer binder in an organic solvent and then mixing the conductive fine powder containing tin oxide as a component. Any solvent is not specified as long as it can dissolve the copolymer binder in the solvent used, and typical examples include methylethylgtone, cyclohexanone, toluene, ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. These may be mixed and used as appropriate. In addition, in order to sufficiently disperse the fine powder in the paint, equipment commonly used for dispersing and blending paint, such as a sand mill,
A ball mill, high speed rotating noodle stirrer, three rolls, etc. may be used. In order to further enhance the dispersion of this fine powder, dispersion aids such as silane coupling agents, titanate coupling agents, surfactants, oleic acid, and lecithin may also be used. Furthermore, in order to increase the durability of the coating film, ultraviolet absorbers, stabilizers, etc. may be used in combination, and various dyes may be used for coloring as long as the transparency of the coating film is not impaired. .

The antistatic III bright paint of the present invention prepared in this way should be applied by a general coating method such as a spray method, roll-to-ter method, 70-coater method, bar code method, doctor grade method, or dipping method. applied to the object.

(5) Effects of the Invention The antistatic transparent coating of the present invention contains a specific proportion of conductive fine powder with a particle size of less than 627 m containing tin oxide as a product of the hydroxyl group-containing copolymer. , altitude M1
It is possible to form a coating film that is clear and has excellent antistatic properties and chemical resistance, and the coating film is easily removed by rubbing the surface or wiping it off, and it does not fall off and has excellent durability. hru.

In other words, antistatic properties and transparency are maintained over a long period of time.
Therefore, it has a wider range of applications than conventional antistatic paints.
For example, it is suitably used for painting clean rooms and the like.

(6) Examples Below is the final E! 4 will be described with reference to a preferred embodiment.

Example 1 Copolymer binder containing 10 mol % of 2-hydroxypropyl acrylate and 90 mol 96 of vinyl chloride (S-LEC E-HA, manufactured by Tsukisui Kagaku Kogyo Co., Ltd.) 100 f,
Transparent conductive fine powder containing methyl ethyl lactone 200 (manufactured by Mitsubishi Metals, T-1, particle size Ql/1 m or less) 200
It was charged into a yt-ball mill.

This was dispersed for 48 hours to prepare a transparent paint.

Thereafter, the above paint was spray-painted onto a transparent hard vinyl chloride resin to obtain a sample for performance evaluation, and the surface smoothness of the paint film was found to be good. The above sample was heated at 20°C.
ASTM D-
Changes in surface resistivity were measured in accordance with 257. Further, transparency (haze value) was measured in accordance with ASTM D-1003.

The results were as shown in Tables 1 and 2.Example 2 In Example 1, Esle9 was used as the copolymer binder.
E-11' A vi- Instead of using S-LEC A
(approximately 8 mol% vinyl alcohol, approximately 90 mol% vinyl chloride, approximately 2 mol% vinyl acetate, manufactured by Tsukimizu Kagaku Kogyo Co., Ltd.)
A paint and a coating film were prepared in the same manner as in Example 1 except for the above, and the performance was evaluated.

Surface smoothness was good. Also, the changes in antistatic properties and transparency before and after immersion in chemicals are shown in Tables 1 and 2.

Comparative Example 1 A paint and coating film were prepared in the same manner as in Example 1 except that a polyester resin (Pylon 200, manufactured by Toyobo) was used instead of the hydroxyl group-containing copolymer as the binder in Example 1. and evaluated the performance. The result is the first
The results were as shown in Table and Table 2.

Comparative Example 2 A paint and a coating film were prepared in the same manner as in Example 1 except that 4502 conductive fine powder (T-1) was used instead of 2002 in Example 1, and the surface of the coating film was rough. Further, the antistatic properties and transparency were as shown in Tables 1 and 2.

(Margin below) Table 1 Table 2 The numbers in the table represent haze values (5II).

The contortion membrane was dissolved.

Claims (1)

[Claims] t Hydroxyl group-containing vinyl monomer 2 to 20 mol%, vinyl chloride monomer 80 to 98 mol%, and other polymerizable monomers 0
Conductive fine powder containing tin oxide as a main component and having a particle size of less than 0.2/1 m is contained at a proportion of 100 to 350 parts by weight to 100 parts by weight of a hydroxyl group-containing copolymer containing ~18 mol%. A transparent antistatic paint that is characterized by the ability to