JPH0674407B2 - Antistatic composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antistatic composition.

[Conventional technology]

With the development of the electronic industry in recent years, semiconductor devices have been rapidly advanced and made plastic.However, various problems such as the destruction of semiconductor devices due to electrostatic electrification have also been highlighted more and more. Antistatic agents are on the market.

Among these antistatic agents, as the coating type antistatic agent, those using a surfactant, or a conductive coating material containing carbon particles or metal particles are generally used. A technique has been proposed in which a polymer is introduced into a polymer to obtain an emulsion paint (Japanese Patent Publication No. 57-
22041 publication). On the other hand, the applicant of the present application also proposed a conductive film-forming emulsion excellent in durability as such an antistatic material (JP-A-59-219304).

[Problems to be solved by the invention]

However, these antistatic agents and low-resistance treatment agents are
There are drawbacks such as lack of durability and formation of black or opaque paint film.

That is, the surfactant forms a conductive monomolecular film by its coating, but volatilizes during long-term use, is easily desorbed by friction, and is further released by water or solvents,
It has the drawback that its conductivity decreases or disappears. Further, the conductive paint is a composite in which carbon-based particles or metal-based particles are mixed in a polymer, and has relatively durability, but lacks transparency, and not only cannot perform a see-through function, It has drawbacks such as impairing the appearance of the material to be coated and being unable to print. Furthermore, in the above-mentioned conventional technique, the obtained coating film (film) is improved in transparency and it is recognized that the durability is also improved as compared with the above-mentioned conventional technique, but it is still insufficient and it is difficult to put to practical use. is there.

Further, although the emulsion previously proposed by the applicant of the present application forms a durable transparent conductive film, the coating film hardness is rather low, and the scratch resistance may be poor.

The present invention has been made against the background of the above-mentioned conventional technical problems, and has excellent conductivity, transparency, durability, and high hardness,
It is an object of the present invention to provide an antistatic composition capable of forming a transparent conductive film having scratch resistance.

[Means for solving problems]

The present invention relates to (a) trimethylammonium chloride component-based copolymer (hereinafter also referred to as "(a) copolymer") and (b) active energy ray-curable resin urethane acrylates (hereinafter "(b) active"). The present invention provides an antistatic composition containing an energy ray-curable resin as a main component.

The antistatic composition of the present invention achieves the above object by containing (a) a specific copolymer and (b) an active energy ray-curable resin.

Hereinafter, the present invention will be described in detail according to constituent features.

(A) Copolymer (a) The copolymer is obtained by copolymerizing (a) an ionic electrolyte monomer having an ethylenically unsaturated group and (b) a monomer having an ethylenically unsaturated group.

The (a) ionic electrolyte monomer having an ethylenically unsaturated group that constitutes the copolymer of the present invention is any monomer as long as it has both an anionic or cationic electrolyte group and an ethylenically unsaturated group. But you can use it.
Typical examples thereof include methacryloyloxyethyltrimethylammonium chloride, 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride and the like, and all of the ethylenically unsaturated monomers having a quaternary ammonium group are used. However, a cationic electrolyte monomer having both a cationic electrolyte group and an ethylenically unsaturated group in terms of conductivity is preferably used, and particularly, a quaternary ammonium group-containing salt such as methacryloyloxyethyltrimethylammonium. Chloride and 2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride are preferably used.

The (a) ionic electrolyte monomer having an ethylenically unsaturated group may be used alone or in a combination of 2
It is also possible to use two or more species together.

(A) The ratio of the ionic electrolyte monomer having an ethylenically unsaturated group to all monomers is 10 to 50% by weight, preferably 20 to 40% by weight (however, (a) + (b) = 100% by weight, The same shall apply hereinafter), and if the amount is less than 10% by weight, the desired conductivity cannot be fully exhibited, while if the amount exceeds 50% by weight, the conductivity will reach equilibrium and the conductivity will be further improved. In some cases, the ratio of (a) the ionic electrolyte monomer having an ethylenically unsaturated group is too large, and the resulting copolymer may not have a sufficiently large molecular weight.

The ratio of the (a) ionic electrolyte monomer having an ethylenically unsaturated group in the composition of the present invention is usually 5 to 18% by weight, preferably 7 to 15% by weight. If it is less than wt%, the antistatic performance of the resulting composition is not sufficient, while if it exceeds 18 wt%, the proportion of (b) active energy ray-curable resin decreases, and a coating film formed from the composition of the present invention. The hardness and scratch resistance may decrease.

Examples of the (b) monomer having an ethylenically unsaturated group include vinyl acetate, styrene, alkyl acrylate, alkyl methacrylate, ethylene, propylene,
Vinyl chloride, acrylonitrile, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, (meth) acrylic acid, itaconic acid, citraconic acid,
Fumaric acid, maleic acid, N-methylol (meth) acrylamide, alkoxymethyl (meth) acrylamide,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, dimethylamino-2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide and the like can be mentioned.

The monomer (b) having an ethylenically unsaturated group is
They may be used alone or in combination of two or more.

Further, the proportion of the monomer (b) having an ethylenically unsaturated group in all monomers is 50 to 90% by weight, preferably
60-80% by weight.

The (a) copolymer used in the composition of the present invention is
It can be easily produced by radical emulsion polymerization of the mixture of the monomers (a) and (b) in an aqueous medium or radical polymerization in an organic solvent, and particularly radical polymerization in an organic solvent. preferable.

Preferred organic solvents used at this time include alcohols such as methanol, ethanol, i-propyl alcohol, n-propyl alcohol, and i-butyl alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether. Although polyhydric alcohol derivatives such as acetate and ethylene glycol monobutyl ether can be used, aromatic hydrocarbons such as toluene, xylene and ethylbenzene can be used in these organic solvents; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; It is also possible to use a mixed solvent in which esters such as isobutyl acetate, ethyl acetate and butyl acetate are mixed.

As the initiator in the copolymerization reaction, for example, organic peroxides such as benzoyl peroxide, cumene hydroperoxide, lauroyl peroxide, and paramenthane hydroperoxide, and azo radical initiators such as azobisisobutyrinitrile are used. It The amount of the radical initiator used is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of all the monomers. Further, in this radical copolymerization, a molecular weight modifier such as dialkylxanthogen disulfide or t-dodecyl mercaptan can be used. (A)
The monomers (b) to (b) and the radical initiator may all be added at the start of the polymerization, or may be added separately after the start of the polymerization, and the polymerization system may be a batch system or a continuous system.

The copolymerization is usually carried out in a nitrogen atmosphere with oxygen removed, and the polymerization temperature is 50 to 100 ° C. and the polymerization time is about 5 to 10 hours.

After the completion of the copolymerization reaction, the obtained polymerization solution may be directly mixed with the active energy ray-curable resin (b) to be described later to form the composition of the present invention, or it may be put into a non-solvent and precipitated. After the copolymer is recovered, for example, the obtained copolymer and (b) the active energy curable substance described below may be mixed with an organic solvent, if necessary.

(B) Active energy ray-curable resin An active energy ray-curable resin is a polymer that is crosslinked and cured by irradiation with active energy rays such as ultraviolet rays, electron beams, and deep ultraviolet rays (hereinafter referred to as "photosensitive polymer"). Known resins such as

Here, as the photosensitive polymer, a polyurethane synthesized from polyethylene glycol and 2,4-tolylene diisocyanate is reacted with 2-hydroxyethyl methacrylate or N-methylol acrylamide,
Urethane acrylates such as those obtained by urethane-forming hydroxyethyl phthalyl methacrylate with xylene isocyanate; and the like.

These photosensitive polymers may include reactive diluents such as 2-ethylhexyl acrylate, 1,6-hexanediol diacrylate, and trimethylolpropane triacrylate, and diethoxyacetophenone, isobutyl benzoin ether, and benzol dimethyl as needed. A photopolymerization initiator such as ketal or benzophenone may be blended.

These photosensitive polymers may be used alone,
Further, two or more kinds can be used in combination.

In the composition of the present invention, the ratio of (a) copolymer and (b) active energy ray-curable resin is 1: 1 by weight of solid content.
1 to 1: 3, preferably 1: 1.5 to 1: 2.5, (a) if the amount of the copolymer is too small, the conductivity of the obtained composition decreases, while if it is too large, the composition obtained is used. When a coating film is formed, the hardness decreases and the scratch resistance becomes poor.

The composition of the present invention uses the above-mentioned (a) copolymer and (b) active energy curable resin in an organic solvent, for example, an organic solvent used as the polymerization solvent, and usually has a solid content concentration of 10 To 90% by weight, preferably 30 to 50% by weight.

An organic polar solvent may be added to the organic solvent in order to improve the adhesion to the material to be coated. This organic polar solvent is an organic solvent having polarity in the molecule,
For example, picoline, monoethanolamine, diethanolamine, morpholine, dimethylformamide, dimethylacetamide, hexamethylphosphortriamide, N-
Nitrogen-containing compounds such as methylpyrrolidone; sulfur compounds such as sulfolane and dimethyl sulfoxide.

These organic polar solvents may be used alone,
Alternatively, two or more kinds can be used in combination. In particular, dimethylformamide (DMF) and / or dimethylsulfoxide (DMSO) are preferable as the organic polar solvent.

Generally, plastics that require coating with an antistatic composition include polyvinyl chloride, polycarbonate, polymethylmethacrylate, polyethylene terephthalate, and the like.As solvents that corrode these plastics, ketones, aromatics, etc. There are many group hydrocarbons, cellosolves, etc., but even if these organic solvents are used, the adhesion to the material to be coated of the antistatic composition obtained may not be improved. The addition of the solvent makes it possible to improve the adhesion.

The addition amount of the organic polar solvent is usually 1 to 40 parts by weight, preferably 5 to 30 parts by weight, and less than 1 part by weight of the organic polar solvent with respect to 100 parts by weight of the composition (solid content conversion). If the amount of polar solvent used is too small, the adhesion of the resulting film to the coated material will be poor, while if it exceeds 40 parts by weight, the adhesion will improve, but the antistatic property originally possessed by the composition , Durability may deteriorate.

In addition, the composition of the present invention comprises the above-mentioned (a) copolymer and (b)
The main component is an active energy ray-curable resin, but in addition to this, a usual resin for paints, a preservative, a pigment, a plasticizer, and a surfactant may be blended in appropriate amounts.

The antistatic composition of the present invention has excellent antistatic properties, durability, transparency, and adhesiveness, and has high hardness and excellent scratch resistance, and therefore, for example, electrostatic charge for coating plastic sheets and plastic molded products. It can be effectively used for applications such as inhibitors and paints.

[Action]

The antistatic composition of the present invention is one in which the (a) copolymer imparts conductivity and (b) imparts hardness and scratch resistance to a coating film from which an active energy ray-curable resin is obtained. ,
This makes it possible to form a coating film having good conductivity, hardness, and scratch resistance.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to the examples below. In the examples, parts and% are based on weight unless otherwise specified.

Reference Example 1 A polymerization tank equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen inlet tube was charged with 405 parts of methyl cellosolve and 194 parts of methanol.
Parts, methacryloyloxyethyltrimethylammonium chloride 80 parts, styrene 60 parts, methyl methacrylate 30 parts, butyl acrylate 20 parts, acrylic acid 10 parts and benzoyl peroxide 1 part, and stirring and heating while introducing nitrogen, A polymerization reaction was carried out at 5 ° C for 5 hours. The solid content concentration of the obtained antistatic copolymer solution A was 25% by weight, and the viscosity was 150 cps / 25 ° C.

Examples 1 to 3 and Comparative Examples 1 to 3 In the antistatic copolymer solution A obtained above, urethane acrylate (manufactured by Dainippon Ink and Chemicals, Inc., UV curable paint, Unidick 17-824, A solid content concentration of 75%) was mixed at a solid content ratio (weight ratio) shown in Table 1 to obtain a composition having ultraviolet curability and antistatic property.

Each of the above compositions was coated on a polyester film having a thickness of 100 μm using a bar coater # 10, pre-dried at 60 ° C. for 5 minutes, and then using a concentrating ultraviolet irradiation device (80 W / cm high pressure mercury lamp). It was irradiated with ultraviolet rays for 30 seconds (the distance from the sample was 15 cm). The results of the obtained coating film are shown in Table 2.

In addition, in Table 2, each evaluation item is as follows.

Transparency: It was visually compared with a 100 μm-thick polyester film as a base material.

Surface resistance: Tokyo Denshi Co., Ltd., Stack (STACK) T
It was measured using R-3. The surface resistance was measured by leaving it in an airtight container whose humidity was adjusted for 1 hour or more, and then measuring it under the same conditions (25 ° C., 50% RH).

Pencil hardness: Measured according to JIS K-5400 standard.

Adhesion: According to cross-cut cellophane tape peeling test.

The evaluation of transparency and adhesion was based on ◯: good, Δ: somewhat poor, and ×: poor.

As is clear from the results shown in Table 2, the conductive film formed from the composition of the present invention is excellent in transparency, hardness, adhesion and durability.

〔The invention's effect〕

The coating film formed from the antistatic composition of the present invention,
Since it consists of a copolymer (trimethylammonium chloride component-based copolymer) in which a conductivity-imparting substance is copolymerized in the molecular chain of the polymer and urethane acrylates which is an active energy ray-curable resin, it has an active energy such as ultraviolet rays. When irradiated with rays, it cures quickly and efficiently, forming a strong conductive polymer film, and forming a coating film excellent in transparency, hardness, scratch resistance, adhesion, and durability, It is particularly useful as an antistatic paint.

Claims (1)

[Claims] 1. An antistatic composition comprising (a) a trimethylammonium chloride component-based copolymer and (b) a urethane acrylate, which is an active energy ray-curable resin, as main components.