JPH1060057A - Resin composition and antistatic coating film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, excellent in adhesion, etc., to various substances and capable of forming an antistatic coating film by copolymerizing a cation-modified copolymer with a free-radically polymerizable monomer. SOLUTION: This resin composition is obtained by carrying out the copolymerization of a mixture of (A) 3-90wt.% cation-modified polymer comprising 70-99mol% ethylenic structural unit represented by the formula (CH2 -CH2 ), 0-15mol% acrylate structural unit represented by the formula (CH2 -CHCOOR<1> ) (R<1> is a 1-4C alkyl) and 1-15mol% acrylamide structural unit represented by the formula (R<2> is a 2-8C alkylene; R<3> to R<5> are each independently a 1-12C alkyl, etc.; X is a halogen, CH3 OSO3 , etc.) with (B) 10-97wt.% free-radically polymerizable monomer (e.g. an acrylic ester or an aromatic vinyl monomer) in an environment for generating free radicals and copolymerizing the free- radically polymerizable monomer B. Furthermore, a monomer having hydroxyl group in the molecule in the component B is preferably used as an essential component in order to maintain the transparency of a cured coating film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic interpenetrating resin composition and an antistatic coating film using the same.

[0002]

2. Description of the Related Art Plastics are excellent in light weight, moldability, and appearance, so that they can be formed in the form of molded articles, films and sheets, housings of home appliances and office equipment, automobile parts, various packaging materials, and the like.
Widely used for sundries and other items, but the drawback is that the high electrical resistance of the material itself causes the static electricity generated by friction and peeling to accumulate without leaking. Electronic devices and the like have a problem of malfunction due to discharge.

[0003] It is conventionally known to use an antistatic agent to cope with such an electrostatic disturbance. That is, an antistatic agent composed of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like is kneaded into a plastic (internal addition) or applied to a plastic surface (external application). Is commonly done.

In the case of internal addition, although the durability of the antistatic effect is relatively good, it is necessary to add it to the entire plastic material, so that the amount of addition increases and causes an increase in cost. In the case of external coating, since it is applied only to the surface, the cost increase factor is relatively small, but it is regarded as a problem in terms of durability. That is, when the surface is rubbed or washed with water, the antistatic agent easily falls off and loses its effectiveness.

[0005]

In order to solve this problem, the present inventors disclosed in Japanese Patent Application Laid-Open No. 198309/1992 an aqueous composition of a polyacrylamide copolymer containing a quaternary ammonium salt group on the surface of plastic. We have developed a method to apply the coating on the surface and have proposed a coating with abrasion resistance and durability.
However, even with this method, there is still a need for improvement in situations requiring further durability, for example, in terms of friction durability under wet conditions and durability against water washing at high temperatures.
There is also room for improvement in terms of adhesion to a substrate such as a polyethylene terephthalate film.

On the other hand, another means for obtaining an antistatic coating film is disclosed in, for example, JP-A-2-120370 and JP-A-3-1370.
As disclosed in Japanese Patent No. 26769, there is known a method in which a conductive salt such as perchloric acid or thiocyanate is contained in a free radical polymerizable monomer and irradiated with radiation to obtain an antistatic cured coating film. Have been. However, in this method, the material used for conductivity is low in molecular weight and essentially water-soluble, so that it is at an unsatisfactory level in terms of water resistance. Similarly,
A similar method using a quaternary ammonium salt type surfactant, for example, triethyl alkyl ether ammonium sulfate as a conductive agent has been proposed in Japanese Patent Application Laid-Open No. Sho 60-221414, but it is a water-soluble low molecular weight compound. It has the same disadvantages as above.

It has also been proposed to use a polymer compound containing a quaternary ammonium base as a conductive agent for an active radiation-cured coating film, for example, as disclosed in JP-A-57-9852.
No. 8 discloses a water-soluble cationic resin obtained by pendant addition of a quaternary ammonium salt to polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide or a polyacrylate resin or a modified product thereof. JP-A-59-53540 discloses a water-soluble acrylic conductive resin having a cationic quaternary ammonium functional group, and JP-A-4-1247 discloses a styrene-chloromethylstyrene copolymer trimethylamine 4. The use of grades has been proposed in each case. The method of using a high molecular compound as a conductive agent of such an active radiation-cured coating film has certainly improved water resistance as compared with the method of using the low molecular compound as a conductive agent, At present, there is no answer to the requirements for friction durability under conditions and durability against high temperature sewage washing.

[0008]

Means for Solving the Problems The present invention has been made as a result of intensive studies to solve such conventional problems. That is, the present invention provides a formula

[0009]

Embedded image

[0010] 70-99 mol% of ethylene structural units represented by the formula:

[0011]

Embedded image

Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms, and 0 to 15 mol% of an acrylate structural unit represented by the formula:

[0013]

Embedded image

(Wherein R ² is an alkylene group having 2 to 8 carbon atoms; R ³ , R ⁴ and R ⁵ are each independently an alkylene group having 1 to 12 carbon atoms)
X is a halogen atom, an alkyl group having 7 to 12 carbon atoms, an arylalkyl having 7 to 12 carbon atoms or an alicyclic alkyl having 6 to 12 carbon atoms;
CH ₃ OSO ₃ , C ₂ H ₅ OSO ₃ , R ⁶ SO ₃ , where R ⁶ is R ³ , R
⁴ , the same as the meaning of R ⁵ ), 3 to 90% by weight of a cation-modified copolymer (A) composed of 1 to 15 mol% of an acrylamide structural unit, and a free-radically polymerizable monomer (B) 1
0 to 97% by weight, or the free radical polymerizable monomer (B) has a hydroxyl group in the molecule.
A resin composition obtained by polymerizing a mixture containing 7% by weight as an essential component in a free radical-generating environment with the free-radical polymerizable monomer, and an antistatic coating film using the same. To provide.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[Component A] The cation-modified copolymer used as the component A of the present invention has the formula

[0016]

Embedded image

70 to 99 mol% of an ethylene structural unit represented by the formula:

[0018]

Embedded image

Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms, wherein 0 to 15 mol% of an acrylate structural unit represented by the formula:

[0020]

Embedded image

(Wherein, R ² is an alkylene group having 2 to 8 carbon atoms; R ³ , R ⁴ , and R ⁵ are each independently an alkylene group having 1 to 12 carbon atoms)
X is a halogen atom, an alkyl group having 7 to 12 carbon atoms, an arylalkyl having 7 to 12 carbon atoms or an alicyclic alkyl having 6 to 12 carbon atoms;
CH ₃ OSO ₃ , C ₂ H ₅ OSO ₃ , R ⁶ SO ₃ , where R ⁶ is R ³ , R
⁴ is acrylamide copolymer having a weight average molecular weight 1,000 to 50,000 which is irregularly arranged in a line shape having acrylamide structural units 15 mole% represented by the same) the meaning of R ^5. The copolymer used in the present invention is a small amount of other structural units as long as the effects of the present invention are not impaired,
For example, acrylic acid, methacrylic acid, acrylonitrile,
There is no problem even if structural units such as glycidyl methacrylate and styrene are contained.

The weight average molecular weight referred to in the present specification is defined as gel permeation chromatography (GPC).
Means the monodisperse weight average molecular weight in terms of polystyrene measured in the above. The ethylene structural unit (A) represented by the formula (1)
When -1) is less than 70 mol%, the durability of the coating film at the time of high-temperature washing is deteriorated, and when it exceeds 99 mol%, the antistatic effect is poor. The preferred range is 80-97 mol%.

Further, the structural unit of the acrylate structural unit (A-2) represented by the formula (2) is not necessarily essential in the present invention, but the presence thereof makes the miscibility with the component (B) good so that it is transparent. It is preferable because a cured film can be easily obtained, but if it exceeds 15 mol%, it is not preferable because the coating film becomes sticky. The preferred range is 1 to 10 mol%.

When the acrylamide structural unit (A-3) represented by the formula (3) is less than 1 mol%, the antistatic property is insufficient, and when it exceeds 15 mol%, the high temperature water resistance of the coating film is low. Getting worse. A preferred range is 2 to 10 mol%. When R ¹ in the formula (2) exceeds 4 carbon atoms, the coating film becomes too soft and causes stickiness. Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-
A butyl group and a t-butyl group can be exemplified. Preferred are methyl and ethyl groups.

Examples of R ² in the formula (3) include an ethylene group, a propylene group, a hexamethylene group and a neopentylene group. Ethylene and propylene groups are preferred from the viewpoint of ease of production and economy. Further, R in the formula (3)
Examples of the alkyl group having 1 to 12 carbon atoms of ³ , R ⁴ and R ⁵ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group and an n-
Examples thereof include a butyl group, a sec-butyl group, an n-octyl group, and an n-lauryl group. Preferred are methyl and ethyl groups. Examples of the arylalkyl group having 7 to 12 carbon atoms include a benzyl group and a 4-methylbenzyl group.

Examples of the alicyclic alkyl group having 6 to 12 carbon atoms include a cyclohexyl group and a methylcyclohexyl group. X in the formula (3) is a halogen atom such as Cl, Br and I, an alkyl sulfate such as CH ₃ OSO ₃ and C ₂ H ₅ OSO ₃ , methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid and dodecane. Examples thereof include sulfonic acid, p-toluenesulfonic acid, and meta-xylenesulfonic acid. Preferred from the viewpoint of antistatic performance is Cl, CH ₃ SO ₃ ,
C ₂ H ₅ SO ₃ , methanesulfonic acid, ethanesulfonic acid, and paratoluenesulfonic acid.

When the weight average molecular weight is less than 1,000, the strength of the cured coating film is insufficient. If it exceeds 50,000, the viscosity of the blend with the component (B) becomes too high, and coating becomes difficult. Preferably, the weight average molecular weight is 3000 to
30,000. The content of the cation-modified copolymer (A) component is 3 to 90% by weight, preferably 5 to 60% by weight. If it is less than 3%, the antistatic property is poor. If it exceeds 90%, the water resistance tends to be insufficient, and the transparency and the adhesion to the substrate tend to be poor.

The free-radically polymerizable monomer used in the component (B) of the present invention is a monomer having at least one carbon-carbon double bond in the molecule, and may be an acrylate ester, a methacrylate ester, Aromatic vinyl monomers, acrylamide derivatives, and heterocyclic vinyl monomers are used. In the present invention, the transparency of the cured coating film obtained by using at least one of the monomers (B-1) having a hydroxyl group in the molecule among these free-radical polymerizable monomers is maintained. It is desirable from the viewpoint of doing.

Examples of the free radical polymerizable monomer (B-1) include hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, mono (meth) acrylate of polyoxyethylene (Mn <20,000) glycol, and glycerin. Mono or di (meth) acrylate, trimethylolpropane mono or di (meth) acrylate, pentaerythritol mono or di or tri (meth) acrylate, dipentaerythritol mono or di or tri or penta (meth) acrylate, bis ( (Hydroxyethyl) bisphenol A mono (meth)
Partial (meth) acrylates of polyhydric alcohols such as acrylate and bis (hydroxyethyl) resorcinol mono (meth) acrylate; aromatic monomers such as ethoxylate of parahydroxystyrene; and acrylamide derivatives such as methylolacrylamide. Can be

In the present invention, among the component (B-1), a free radical polymerizable monomer having only one carbon-carbon double bond in the molecule, such as hydroxyethyl (meth) acrylate, is used. When it is selected as the component (B-1), the cured coating film tends to have poor water resistance. For the purpose of maintaining this, two or more carbon-carbon double bonds are added to the molecule in addition to the component B-1. Having a free radical polymerizable monomer (B-
It is desirable to use 2) in combination.

Examples of the free radical polymerizable monomer (B-2) include poly (oxyalkylene) (ethylene, propylene, butylene; Mn <20,000) glycol di (meth) acrylate, glycerin tri (meth) acrylate, and tri (meth) acrylate. Methylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bis (hydroxyethyl) bisphenol A di (meth) acrylate, bis (hydroxyethyl) resorcinol di (meth) acrylate, 1 (Meth) acrylates of polyhydric alcohols such as 1,4 tetramethylene glycol di (meth) acrylate and 1,6 hexanediol di (meth) acrylate; aromatic vinyl monomers such as divinylbenzene; Acrylamide derivatives such as bis-acrylamide.

In the present invention, in addition to the free-radically polymerizable monomer (B-1) and / or (B-2), the viscosity of the paint is reduced to facilitate application, or the cured coating film is hardened. Other free-radical polymerizable monomers (B-3) can be used for the purpose of adjusting the hardness. Examples of the free radical polymerizable monomer (B-3) include methyl (meth) acrylate and ethyl (meth)
Acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, ethylhexyl (meth)
(Meth) acrylates such as acrylate, benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate; and aromatic vinyls such as styrene, α-methylstyrene, and paramethylvinylbenzene Monomers, acrylamide derivatives such as acrylamide, dimethylacrylamide, diethylacrylamide, dimethylaminoethylacrylamide, dimethylaminopropylacrylamide, isopropylacrylamide, and acroylmorpholine; and complex compounds such as N-vinylpyrrolidone, N-vinyloxazoline, and vinylpyridine Cyclic vinyl monomers.

In the present invention, the transparency of the coating film is maintained,
From the viewpoint of maintaining water resistance, the components (B-1) and (B-2) are essential. The preferred ratio is (B-
1) / (B-2) = 95-20 / 5-80 (weight ratio),
More preferably, it is 90-50 / 10-50 (weight ratio). If the component (B-1) is 95 or more, water resistance can no longer be maintained, and if it is less than 20, the transparency of the coating film tends to decrease. (B-3) is appropriately used as needed, and the ratio is ((B-1) + (B-2)) / (B-3) = 1.
00-20 / 0-80 (weight ratio). If the component (B-3) exceeds 80, it will be difficult to maintain water resistance.

The content of the component B composed of (B-1) + (B-2) + (B-3) is 10 to 97% by weight, preferably 40 to 95% by weight. If it is less than 10% by weight, the water resistance is insufficient, and the transparency and the adhesion to the substrate are also at an insufficient level. On the other hand, if it exceeds 97%, the antistatic property is insufficient. The present invention is practiced in a free radical generating environment. When high-energy radiation such as electron beam or γ-ray is used as a means for generating free radicals, the presence of the polymerization initiator (C) component is not always necessary. In the case where the polymerization initiator (C-1) is used and the ultraviolet polymerization is started, it is necessary to add the photopolymerization initiator (C-2).

Examples of the thermal polymerization initiator (C-1) include organic peroxides such as methyl ethyl ketone peroxide, diisopropylbenzene hydroperoxide, dicumyl peroxide, tertiary butyl peroxy acetate, and benzoyl peroxide. , 2'-Azobis (2-
Methylbutyronitrile), 1,1'-azobis (1-cyclohexanecarbonitrile), azobisisobutyronitrile, 4,4'-azobis (4-cyanopentanoic acid)
And other azo compounds.

Examples of photopolymerization initiation (C-2) include:
Benzoin such as benzoin, benzoin isopropyl ether and benzoin isobutyl ether or alkyl ethers thereof, benzophenone, Michler's ketone, 4
Benzophenones such as benzoylbenzyltrimethylammonium chloride, 2,2-dimethoxy-2-
Acetophenones such as phenylacetophenone, 2,2-dichloro-4′-phenoxyacetophenone, diethylthioxanthone, diisopropylthioxanthone,
And thioxanthones such as 2- (carbomethoxy) thioxanthone and 2- (3-sulfopropoxy) thioxanthone.

In order to enhance the efficacy of (C-2), n-
A sensitizer such as butylamine, triethylamine, triethanolamine, methyldiethanolamine, and ethyldiethanolamine can coexist. (C-
The added amount of the components 1) and (C-2) is 0.5 to 7% by weight, preferably 1 to 5% by weight, based on the total amount of the components A and B. If it is less than 0.5%, curing will be insufficient and a coating film with sufficiently improved water resistance cannot be obtained. If it exceeds 7%, the improvement of water resistance is no longer seen, and it is uneconomical.

The mixture consisting of the components (A), (B) and / or (C) can be applied as it is, but if necessary, diluted with an inert solvent until it has a suitable viscosity. After the solvent is evaporated, the composition can be cured. Examples of such a solvent include lower alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol and isobutanol, aromatic hydrocarbon solvents such as benzene, toluene and xylene, methyl cellosolve, and ethyl cellosolve. ,
Cellulsolves such as butyl cellosolve and aprotic polar solvents such as dimethylformamide, dimethylsulfoxide and γ-butyrolactone can be used. Of these,
Alcohols, aromatic hydrocarbon solvents and mixtures thereof are preferred.

Although there is a limitation from the viewpoint that the drying speed as a pretreatment before curing is low, water is used in place of the above-mentioned solvents, and the emulsifier is emulsified using a uniform or dispersed or, if necessary, an emulsifier. Or after converting the component (A) into an aqueous composition by a method according to JP-A-4-198309,
Alternatively, the composition of the present invention can be applied by blending the component (C).

When the solvent or water is used, the total concentration of the components (A), (B) and (C) is 5 to 60% by weight, preferably 10 to 50% by weight. The composition of the present invention is polyethylene terephthalate, polypropylene,
Used for transparent or translucent plastic films, sheets and molded products based on polyethylene, polystyrene, polymethyl methacrylate, polycarbonate, polyvinyl chloride, ethylene-vinyl acetate copolymer, etc., packaging materials for various materials, IC It is suitable for use as transport containers, display windows for home appliances, covers for various meters, and windows for clean rooms. Not limited to the above transparent material, for example, A
Of course, it can also be applied to opaque base materials such as the housing of household appliances made of BS resin and HIPS resin, wood furniture and flooring, flooring made of polyvinyl chloride, and paper products such as information recording paper. Yes, the advantages of durability of the present invention can be utilized.

The composition of the present invention is applied to the above-mentioned various substrates according to the shape of the object to be coated such as roll coating, bar coating, air knife coating, spin coating, screen printing, spraying, dipping, etc. Can be appropriately selected from the above methods for coating. When a solvent or water is used for preparing the composition, a pretreatment for drying is performed after coating. In order to carry out the composition of the present invention, a curing step is essential. As such a curing means, a known method can be used, and curing is performed by the action of an electron beam, heat, or ultraviolet light. That is, in the case of using an electron beam, the object to be coated with the composition comprising the components (A) and (B) of the present invention is cured by placing it under electron beam irradiation with an intensity of 1 to 6 megarads.

In the case of using the action of heat, (A) of the present invention,
Coating of the composition comprising (B) and (C-1) with 6
Curing is performed by maintaining the temperature at 0 to 150 ° C, preferably 80 to 120 ° C. Incidentally, in the drying step when a solvent or water is used for the preparation of the composition, the drying and the curing step can be performed simultaneously. In the case of using the action of ultraviolet rays, (A), (B), (C-
The coating is carried out by placing an object to be coated with the composition comprising 2) under irradiation of a high-pressure mercury lamp.

Among these curing means, curing by an electron beam or ultraviolet rays is particularly preferable from the viewpoint of simplicity of operation, and curing by ultraviolet rays is particularly preferable from the viewpoint of simplicity of the apparatus.

[0044]

【Example】

Example 1 Cation-modified copolymer (AA-1) shown in Table 1 20
Part, free radical polymerizable monomer (B-1-1) shown in Table 2
60 parts, (B-2-1) 20 parts, benzyldimethyl ketal 4 parts, methanol 60 parts, toluene 120
The parts were mixed while heating at 60 ° C. and uniformly dissolved to obtain a composition of the present invention. A dried biaxially stretched polyethylene terephthalate film having a thickness of 50 μm has a thickness of 2.
The coating was uniformly applied to a thickness of 5 μm, dried, and then irradiated with ultraviolet rays by a metal halide lamp at an intensity of 500 mJ / cm 2. The following test was performed on the obtained coating film. Table 6 shows the results. [Surface specific resistance] The surface specific resistance was measured using an Ultra High Resistance Meter R8340 manufactured by Advantest Co., Ltd. under the same conditions after controlling the humidity at 20 ° C. and 65% RH for 24 hours. [Substrate Adhesion] A cellophane tape was stuck to the coating film, and the state of the coating film when peeled off with a strong force was observed.

The coating film remains completely without damage → ○ Part of the coating film is peeled → △ The coating film is completely peeled → × [Light transmittance] Haze computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. Was used to measure the total light transmittance and haze. [Wet friction durability] The coating film was observed for damage after rubbing 80 times with gauze immersed in water.

No damage → ○ Damaged → × After observation, the surface resistivity was measured after humidity control at 20 ° C. and 65% for 24 hours. [Warm water resistance] The film was held for 30 minutes in warm water of 80 ° C with gentle stirring, pulled up and dried, and the surface condition of the coating film was observed.

No change → ○ Rough surface → △ Coating eluted or dropped → × For coating remaining, further at 20 ° C., 65
After conditioning for 24 hours at% RH, the surface resistivity was measured in the same manner as described above.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

[Table 4]

Examples 2 to 5 and Comparative Examples 1 to 4 In the same manner as in Example 1, the cation-modified copolymers shown in Table 1 and the free radical monomers shown in Tables 2 to 4 and, if necessary, a solvent or water Was used to obtain the composition shown in Table 5. This composition was applied and dried in the same manner as in Example 1, and then a cured coating film was obtained using the same ultraviolet ray source or a 2 Mrad electron beam source as in Example 1 as the active radiation source.

The coating film was evaluated in the same manner as in Example 1, and the results are shown in Table 6.

[0054]

[Table 5]

In Example 5, first, emulsification was performed using AA-1 and a predetermined amount of water at 110 ° C. for 15 minutes in accordance with the method of JP-A-4-198309 to obtain an aqueous composition having a solid content of 10% by weight. . Next, a predetermined amount of the B and C components and water, and polyoxyethylene (n = 10) nonylphenol as an emulsifier were used in an amount of 4 parts and emulsified with a homomixer for 5 minutes to obtain an emulsion state, followed by application. In Comparative Example 3,
A having a solid concentration of 10% by weight prepared in the previous step of Example 5
The aqueous composition of A-1 was applied as it was.

[0056]

[Table 6]

Example 6 A coating composition was obtained by using 4 parts of dicumyl peroxide in place of benzyldimethyl ketal in the composition of Example 1 and dried on a 2 mm-thick polycarbonate plate using a bar coater. Is applied to a thickness of 3 μm.
It was left in an oven at 10 ° C. for 10 minutes and dried and cured at the same time to obtain a cured coating film. The coating film was tested in the same manner as in Example 1. As a result, the surface resistivity was 4 × 10 ⁸ Ω / □, the substrate adhesion was ○, the total light transmittance was 89.9%, and the wet friction was 80 times and Even after the hot water resistance test, the surface state did not change and the surface specific resistance values were maintained at 5 × 10 ⁸ Ω / □ and 2 × 10 ⁹ Ω / □, respectively.

[0058]

Industrial Applicability A specific cation-modified copolymer comprising an ethylene structural unit, a quaternary ammonium cation group-containing acrylamide structural unit and an acrylate structural unit, a hydroxyl group-containing free radical polymerizable monomer and a polyfunctional free radical An antistatic coating obtained by coating a composition composed of a polymerizable monomer with a free radical polymerization initiator, if necessary, on a plastic substrate, and then curing the composition with heat, ultraviolet light, or an electron beam. The film is excellent in transparency, adhesion to various substrates and durability, particularly water resistance.

Claims (3)

[Claims] 1. The formula: 70 to 99 mol% of an ethylene structural unit represented by the formula: (Wherein R ¹ represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the following formula: (Wherein R ² is an alkylene group having 2 to 8 carbon atoms; R ³ , R
⁴ and R ⁵ are each independently an alkyl group having 1 to 12 carbon atoms, arylalkyl having 7 to 12 carbon atoms or 6 carbon atoms.
X is a halogen atom, CH ₃ OSO ₃ ,
Acrylamide structural units 1 to 15 represented by C ₂ H ₅ OSO ₃ and R ⁶ SO ₃ , wherein R ⁶ is the same as R ³ , R ⁴ and R ^5.
A mixture consisting of 3 to 90% by weight of a cation-modified copolymer (A) consisting of 3% by mole and 10 to 97% by weight of a free-radical polymerizable monomer (B) is prepared under the free radical-generating environment. A resin composition obtained by polymerizing a monomer. 2. The method according to claim 1, wherein the free radical polymerizable monomer (B) contains a free radical polymerizable monomer having a hydroxyl group in a molecule as an essential component. Resin composition. 3. An antistatic coating comprising the resin composition according to claim 1, which is obtained on the surface of a substrate.