JP3264797B2 - Structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure joined or filled with an acrylic conductive curable composition, the surface of which is electrodeposited or electrostatically coated.

[0002]

2. Description of the Related Art When designing a product excellent in design, such as an automobile or an electric device, it is necessary to keep its appearance good. For example, a structure composed of a large number of panel components, such as an automobile body, has a spoiled appearance as it is because joints between panels are scattered on the body surface. For that purpose, it is necessary to devise an integrated structure. As a method devised in such a manner, a method has been put to practical use in which a joint portion is recessed from the body surface, both steel plates are welded at the recessed portion, and then the recess is filled with metal solder.

However, in this method, since the metal solder has a high fluidity in a molten state and a high specific gravity,
At the time of filling, it drips down by its own weight, which may result in a deepening of the bombs or provision of a drip-stopping portion in the bombs. Further, when the excess solder is polished, there is a problem that the solder powder is scattered in the air and the working environment is contaminated. In particular, since solder contains lead, chronic poisoning may occur due to suction of abrasive powder for a long period of time, and a new treatment method that does not use solder has been desired.

It is also common to use a welding method. However, since the welding method is performed at a very high temperature of 1000 ° C. or more, heat distortion occurs at a joint portion, which causes stress concentration. Was. In addition, welding has disadvantages such as the need for skilled personnel, the need for a large amount of power, the difficulty in joining different metals, and the inability to join with non-metal mixed materials.

Further, after the conventional soldering or welding treatment,
Electrodeposition coating has been performed to prevent corrosion, and electrostatic coating has been performed to improve appearance. In these paints,
In many cases, heating is performed using an oven for baking and drying of the coating film, so that the joining portion and the sealing portion have to be subjected to heat history.

[0006] On the other hand, the bonding method almost solves the above-mentioned problem of soldering or welding, and further has the advantages of increasing the durability by dispersing the stress applied to the joint and reducing vibration. The joining and sealing of different materials with the curable resin composition have been gradually performed. Examples of the adhesive include an epoxy resin adhesive, a urethane resin adhesive, and an acrylic resin adhesive.

[0007]

However, these adhesives have the following problems, and a structure in which the surfaces of the adherend and the curable resin composition are uniformly electrodeposited or electrostatically coated is used. Could not be obtained. Examples of the epoxy resin-based adhesive include a one-component adhesive obtained by mixing an epoxy resin-based adhesive as a main component and dicyandiamide as a curing agent, and a two-component adhesive using amine or polyamide as a curing agent. However, the one-component epoxy resin-based adhesive requires a curing time of about 30 minutes at a temperature of about 150 ° C. to 180 ° C., and has a problem that it is difficult to cope with it on a production line. With two-part epoxy resin adhesives, in order to prevent poor curing, complete mixing with a constant mixing ratio with the curing agent is required, and there are problems such as troublesome production management and difficulties. Was.

[0008] The urethane resin-based adhesive is a moisture-curable one-part urethane resin-based adhesive, and a two-part urethane resin-based adhesive containing one liquid containing an isocyanate and the other liquid containing a polyol. There is. However, the one-pack type has problems such as spending several days for curing, and the two-pack type requires quantitative blending and thorough mixing as well as the two-pack type epoxy resin adhesive, and also prevents foaming. There were problems such as the necessity of bonding in an environment where humidity was controlled. Furthermore, the urethane resin-based adhesive has problems such as poor adhesion to the metal oil surface.

As an acrylic resin-based adhesive having a (meth) acryloyl group, a two-component adhesive called a so-called second-generation acrylic adhesive (SGA) is used. However, because it contains a large amount of low-boiling components, it has a strong odor and the heat resistance of the cured product is not sufficient. And other problems.

Commonly used adhesives and fillers for filling air gaps between joints to improve airtightness and watertightness include epoxy resins listed in JP-A-49-83116. Since most are insulators, an electrodeposition paint for preventing corrosion cannot be formed, and there has been a problem that corrosion proceeds from the boundary between the resin and the steel sheet. In addition, since the electrodeposition coating is not applied, even if the intermediate coating and the top coating are performed several times, the surface paintability differs at the boundary between the resin composition and the steel sheet and on the resin composition, and the same paintability is obtained. In addition, there were problems such as the necessity of using a primer or the like in order to obtain the above.

Further, there is a resin composition obtained by imparting conductivity to a pre-cured resin composition only by using a conductive filler as a generally used adhesive or filler. No electroconductive coating was obtained, and no electrodeposition coating for corrosion resistance was obtained. For this reason, at present, it is used only in parts that do not require relatively good appearance such as weld bonding.

In order to solve such problems, the present invention provides a structure characterized by facilitating the steps of coating, curing and polishing, and performing electrodeposition coating or electrostatic coating after polishing. It is. It is another object of the present invention to provide a structure in which the surface of a joint or a filling portion and the surface of a panel component are uniformly finished.

[0013]

That is, the present invention relates to a structure joined or filled with an acrylic conductive curable resin composition in which the cured product has a volume resistivity of 1.0 × 10 ⁶ Ω · cm or less. Wherein the surfaces of the structure and the conductive curable resin composition are subjected to electrodeposition coating or electrostatic coating. Further, the present invention provides a cured product of the acrylic conductive curable resin composition having a tensile elongation at break of 10 to 10.
The structure has a tensile modulus of 70% and a tensile modulus of 1 to 150 kg / mm ² .

That is, according to the present invention, the cured product has a volume resistivity of 1.0 × 10 3 as a filler in a groove of a joint of a panel part such as an automobile body, an electric device and a housing or an adhesive at a joint.
It is characterized in that an acrylic conductive curable resin composition having a resistivity of ⁶ Ω · cm or less is used. By using this acrylic conductive curable resin composition, a structure that can be subjected to electrodeposition coating or electrostatic coating can be obtained.

Acrylic conductive curable used in the present invention
A resin composition is defined as having one (meth) acryloyl group in one molecule.
And the volume resistivity of the cured body is 1.0 ×
10 ⁶Ω · cm or less. Acrylic conductive hard
Curable resin composition is conductive to acrylic curable resin composition
It is obtained by blending a filler.

The acrylic component used in the acrylic conductive curable resin composition of the present invention refers to an acrylic compound selected from (meth) acrylic acid and esters thereof. The acrylic component may be any material as long as it has radical polymerizability, and examples thereof are as follows.

A monomer represented by the general formula AOR ₁ (I). Here, A is a (meth) acryloyl group, CH ₂ CHCHCOOCH ₂ —CH (OH) CH ₂ − or CH ₂ CC (CH ₃ ) COOCH ₂
-CH (OH) CH _2- , wherein R ₁ is hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, a benzyl group, a phenyl group, a tetrahydrofurfuryl group, a glycidyl group, a dicyclopentanyl group or ( Represents a (meth) acryloyl group.

Specific examples of such a monomer include:
(Meth) acrylic acid, methyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate,
Examples thereof include dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, glycerol (meth) acrylate, and glycerol di (meth) acrylate.

The general formula AO- (R_TwoO)_p-R₁ (II) A monomer represented by the formula: Where A and R₁Is one of the above
A and R of the general formula (I)₁Is the same as R _TwoIs -C_TwoH
_Four-, -C_ThreeH₆-, -CH_TwoCH (CH_Three)-, -C_FourH₈-, -C_FiveH_Ten-Or -C₆H
₁₂And p represents an integer of 1 to 25.

Specific examples of such a monomer include 2
-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, phenoxydiethylene glycol (Meth) acrylate, tripropylene glycol di (meth) acrylate and 1,6-hexanediol (meth) acrylate are exemplified.

General formula

Embedded image A monomer represented by Wherein, A is the same as A in the general formula (I), R ₂ are the same respectively as R ₂ in the general formula (II). R ₃ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and q represents an integer of 0 to 8.

Specific examples of such monomers include 2,2
2-bis (4-methacryloxyphenyl) propane, 2,2-bis (4-methacryloxyethoxyphenyl) propane,
2-bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxypropoxyphenyl)
And propane and 2,2-bis (4-methacryloxytetraethoxyphenyl) propane.

(Meth) allylic acid esters of polyhydric alcohols which are not included in the above and the above monomers. Specific examples of such a monomer include trimethylolpropane triacrylate, neopentyl glycol di (meth)
Acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth)
Acrylate and the like.

A urethane prepolymer having a (meth) acryloyloxy group. Specifically, such a monomer is obtained by reacting a (meth) acrylate having a hydroxyl group with an organic polyisocyanate and a polyhydric alcohol. Here, specific examples of the (meth) acrylate having a hydroxyl group include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. As specific examples of the organic polyisocyanate,
Examples include toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Specific examples of the polyhydric alcohol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol polyester polyol.

The above-mentioned and the monomers 1
Species or a combination of two or more species can be used, but it is preferable that at least one of the constituting monomers is a urethane prepolymer having a (meth) acryloyloxy group.

The (meth) acrylate monomer and (meth) acrylic oligomer used in the present invention include:
From the viewpoint of preventing odor and foaming during curing, the (meth) acrylate monomer and the (meth) acrylic oligomer preferably have a boiling point of 100 ° C or higher, more preferably 150 ° C or higher. If the boiling point is less than 100 ° C., foaming or odor may occur during heat curing.

Other components include compounds having an allyl group such as diallyl maleate, diallyl phthalate, triallyl isocyanurate and allyl glycidyl ether, unsaturated acids such as maleic acid, maleic anhydride and itaconic acid, styrene and divinyl. Radical polymerizable monomers such as benzene, α-methylstyrene, vinylpyrrolidone, vinylcaprolactam, and vinyl ether may be used to the extent that the object of the present invention is not impaired.

In the present invention, a conductive filler is added to the acrylic curable resin composition for imparting electrodeposition coating property. The acrylic conductive curable resin composition thus obtained has a cured product having a volume resistivity of 1.0.
× 10 ⁶ Ω · cm or less, preferably 1.0 ×
More preferably, it is 10 ⁵ Ω · cm or less.

The volume resistivity of the cured product is 1.0 × 10 ⁶ Ω
Cm or less, the cured body can be subjected to electrodeposition coating without treatment, and there is no occurrence of surface steps due to poor electrodeposition coating, etc., and as described in JP-A-48-81224. A major feature is that there is no need to perform a rust-proof treatment such as a zinc phosphate-based chemical conversion treatment. When the volume resistivity of the cured product exceeds 1.0 × 10 ⁶ Ω · cm, the surface of the acrylic conductive curable resin composition cannot be electrodeposited or electrostatically coated, It is not preferable because the surface and the surface of the panel component cannot be uniformly finished.

As the material of the conductive filler, zinc,
Various metals such as iron, copper, cobalt, aluminum, nickel and palladium, metal oxides such as ruthenium oxide, bismuth oxide and iridium oxide, sintered composites of metal oxide-iron oxide, α-Fe ₂ O ₃ , Known materials such as Bon Black are exemplified. These powders, flakes or short fibers can be used.

Considering corrosion resistance and cost, carbon black is preferable among the conductive fillers. Examples of the carbon black include acetylene black, furnace black, lamp black, channel black, graphite, and the like, and one or more of these can be used in combination. Among these, acetylene black and furnace black are preferred, and acetylene black, Denka Black and furnace black, Ketjen Black are more preferred.

The amount of the conductive filler used is 2 to 25 parts by weight based on 100 parts by weight of the acrylic curable resin composition in consideration of the conductivity and workability of the acrylic conductive curable resin composition. Parts by weight, and more preferably 3 to 20 parts by weight. If it is less than 2 parts by weight, it is difficult to obtain electrical conductivity, and if it exceeds 25 parts by weight, the viscosity becomes too high, which may impair workability.

In the present invention, in order to shorten the curing time, the acrylic conductive curable resin composition may contain a thermal polymerization initiator. Examples of the thermal polymerization initiator include organic peroxides.

Specific examples of the organic peroxide include (1)
Ketone peroxides include methyl ethyl ketone peroxide, cyclohexanone peroxide,
3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, and the like. (2) Examples of peroxyketals include 1,1-bis (tertiary butyl peroxide). Oxy) -3,3,5-trimethylcyclohexane, 1,
1-bis (tert-butylperoxy) cyclohexane, 2,2-bis (tert-butylperoxy)
Octane, normal butyl-4,4-bis (tert-butylperoxy) valerate and 2,2-bis (tert-butylperoxy) butane;
(3) Hydroperoxides include tertiary butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, 2,5
-Dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl hydroperoxide; and (4) dialkyl peroxides such as ditertiary butyl peroxide and tertiary Butylcumyl peroxide, dicumyl peroxide, α, α′-bis (tert-butylperoxy-meta-isopropyl) benzene, 2,5
-Dimethyl-2,5-di (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3; and (5) diacyl peroxides As acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, laurinoyl peroxide, 3,3,5-trimethylhexanoyl peroxide, succinic acid peroxide, benzoyl peroxide, 2, 4-dichlorobenzoyl peroxide, meta-toluoyl peroxide, and the like. (6) Examples of peroxydicarbonates include diisopropyl peroxydicarbonate, di-2-ethylhexylperoxydicarbonate, and dinormalp. Pill peroxydicarbonate,
Bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethylperoxydicarbonate, dimethoxyisopropylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate and diallyl per Oxydicarbonate; and (7) peroxyesters such as tertiary butyl peroxyacetate, tertiary butyl peroxyisobutyrate, tertiary butyl peroxypivalate, and tertiary butyl peroxyneodeca. Noate, cumyl peroxy neodecanoate, tertiary butyl peroxy-
2-ethylhexanoate, tert-butylperoxy-3,3,5-trimethylhexanoate, tert-butylperoxylaurate, tert-butylperoxybenzoate, ditertiary-butylperoxyisophthalate, 2,5 -Dimethyl-2,5-di (benzoylperoxy) hexane, tertiary butyl peroxymaleic acid, tertiary butyl peroxyisopropyl carbonate, cumyl peroxy octoate, tertiary hexyl peroxy neodecanoate, tertiary Hexyl peroxypivalate, tertiary butyl peroxy neohexanoate, tertiary hexyl peroxy neo hexanoate, cumyl peroxy neo hexanoate, and the like, and ( ) Other organic peroxides,
Acetylcyclohexylsulfonyl peroxide, tertiary butyl peroxyallyl carbonate and the like can be mentioned.

Specific examples of thermal polymerization initiators other than organic peroxides include (1) azobisisobutyronitrile and 2,2'-azobis (4-
Methoxy-2,4-dimethylvaleronitrile), 1,
1′-azobis (cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) azo]
Formamide and 2-phenylazo-4-methoxy-
2,4-dimethylvaleronitrile and the like,
(2) Azoamidine compounds include 2,2′-azobis (2-methylpropionamidine) dihydrochloride, and (3) cyclic azoamidine compounds include 2,2′-azobis [2 -(2-imidazolin-2-yl) propane] and the like,
(4) As the azoamide compound, 2,2′-azobis {2-methyl-normal- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}
And 2,2'-azobis {2-methyl-normal-
[1,1-bis (hydroxymethyl) ethyl] propionamide}, and (5) alkylazo compounds include 2,2′-azobis (2,4,4-
Trimethylpentane) and the like. One or more of these polymerization initiators can be used.

The amount of the thermal polymerization initiator used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic curable resin composition. If it is less than 0.1 part by weight, the curing will be slow,
If the amount exceeds 10 parts by weight, the curing speed and the like will not be improved, but the heat resistance may be lowered.

In the present invention, in consideration of the stability and the curing time of the acrylic conductive curable resin composition, the thermal polymerization initiator has a decomposition temperature of 80.degree.
Those at 60 ° C. are preferred. If the decomposition temperature is lower than 80 ° C., the stability may decrease. If the decomposition temperature exceeds 160 ° C., the curing time may be prolonged. Specifically, peroxy ketals, peroxy esters and hydroperoxides are preferred, and 1,1 of peroxy ketals are preferred.
-Bis (tert-butylperoxy) -3,3,5
Trimethylcyclohexane, tertiary butyl peroxybenzoates of peroxyesters and cumene hydroperoxide of hydroperoxides are more preferred.

In the acrylic conductive curable resin composition of the present invention, an inorganic filler other than the conductive filler can be used as long as the characteristics of the present invention are not impaired. By using the inorganic filler, the tensile elongation at break and the tensile modulus of the acrylic conductive curable resin composition can be made appropriate.
The amount of the inorganic filler used is the amount of the acrylic curable resin composition 1
The amount is preferably 10 to 150 parts by weight with respect to 00 parts by weight.
Examples of the inorganic filler other than the conductive filler used in the present invention include silica powder such as crystalline silica powder, fused silica powder, spherical silica powder and fumed silica, silica sand, wollastonite, clay, bentonite, mica, and nickel. Slag,
Examples include aluminum hydroxide, silicon carbide powder including spherical particles, silicon nitride powder, boron nitride powder, talc powder, calcium carbonate powder, glass beads, and shirasu balloon.

An organic filler can be used in combination with the inorganic filler as long as the object of the present invention is not impaired. Examples of the organic filler include polyethylene powder, urethane resin powder, (meth) acrylic resin powder, silicone resin powder, fluororesin powder, phenol resin powder, and recycled rubber powder.
Further, various glass fibers, carbon fibers, various aramid fibers, and fibrous materials such as nylon fibers may be used in combination for the purpose of improving the strength and heat resistance.

The cured product of the acrylic conductive curable resin composition of the present invention preferably has a tensile elongation at break of 10 to 70% and a tensile modulus of elasticity of 1 to 150 kg / mm ² ,
Tensile elongation at break is 15-50% and tensile modulus is 10
More preferably, it is 120 kg / mm ² . If the tensile elongation at break is less than 10%, the resin composition cannot follow the distortion of the steel sheet due to vibration or the like, which may cause a crack or a crack. If it exceeds 70%, the resin composition is too soft and may be melted by frictional heat during polishing. If the tensile modulus is less than 1 kg / mm ² , the resin composition may be melted at the time of polishing.
If it exceeds mm ² , the resin composition may not be able to cope with small continuous strains caused by vibrations or the like, and there is a possibility that cracks or cracks may occur.

The viscosity of the acrylic conductive curable resin composition of the present invention before curing is from 50,000 to 1,000,000 cp from the viewpoint of workability.
It is preferably s. If the viscosity is less than 50,000 cps, there is a possibility that the liquid will sag and the workability will deteriorate. If the viscosity exceeds 1,000,000 cps, it may not be possible to apply with a simple coating machine such as a snake pump, grease pump, gear pump, plunger and extruder.
In addition, air may be mixed during coating or filling in the coating machine, which may cause a problem.

In the conventional method using solder, there is a problem in that the solder has a relatively high fluidity in a molten state and has a large specific gravity, causing liquid dripping, and the shape of the groove of the recess cannot be freely set. . In contrast, the resin composition of the present invention has, in the above-mentioned viscosity range, tackiness, low fluidity, and low specific gravity, so that it does not sag in the application step, and the structure of the groove of the hollow is also reduced. There is no restriction. Also, when the thermal polymerization initiator and the polymerization accelerator are not used together in the resin composition, the resin composition does not cure unless heated, so that even if an error occurs during application, it has a feature that it can be easily redone. .

The material of the adherend used in the structure of the present invention is not particularly limited as long as it can withstand heating at 150 ° C., and examples thereof include resin, metal, and mortar concrete. When the adherend is made of a conductive material, the effect can be expected to be further improved, and it is more preferable when the adherend is made of metal, and most preferably steel.

The structure of the present invention can be obtained by applying an acrylic conductive curable resin composition to an adherend by an appropriate means, for example, coating or spraying, and then curing the composition. In particular, in the production of housings such as automobile bodies and electric trains, since it is performed by a conveyor system, when using the curable resin composition of the present invention, it is extremely important to shorten the curing time. It becomes. Since the acrylic conductive curable resin composition of the present invention has a highly reactive (meth) acryloyl group and its reaction mode is a radical polymerization reaction, the epoxy resin-based adhesive or the one-pack type urethane resin-based The curing speed is much faster than adhesives. Even if any method such as near-infrared heater, far-infrared heater, high-frequency heating, electromagnetic induction heating or ultrasonic heating is used, curing is completed within one minute at a temperature raised to 150 ° C. Have.

Since the acrylic conductive curable resin composition of the present invention does not have an equimolar reaction unlike the epoxy resin adhesive and the urethane resin adhesive, there is no need for quantitative mixing or complete mixing. Therefore, the acrylic conductive curable resin composition of the present invention has a feature that quality control is easy. Further, the acrylic conductive curable resin composition of the present invention itself has a feature that it has excellent oil surface adhesiveness. Further, the acrylic conductive curable resin composition of the present invention is easier to polish than metal solder, and the polishing powder of the acrylic conductive curable resin composition is extremely low in toxicity compared to solder polishing powder. Therefore, the working environment can be significantly improved.

[0046]

EXAMPLES The present invention will be specifically described below with reference to examples. The surface of a 1.6 mm thick cold-rolled (SPCC) oil-surface steel plate test piece was wiped off with a rag.

Reference Example 1 An example of a method for synthesizing a urethane prepolymer having a (meth) acryloyl group is shown below. 26.1 parts by weight of isophorone diisocyanate as a polyisocyanate and 0.005 parts by weight of dibutyltin dilaurate as a catalyst are placed in a reaction vessel.
Stirring was carried out while maintaining the reaction temperature at 50 ° C., and 60.3 parts by weight of polybutylene glycol having an average molecular weight of 1,000 was gradually added as a polyol to carry out the reaction. Further, 13.6 parts by weight of 2-hydroxyethyl methacrylate as a (meth) acrylate having a hydroxyl group was gradually added to the reaction solution while stirring and maintaining the temperature of the reaction solution at 70 ° C. to carry out a reaction. The isocyanate group in this reaction solution was analyzed using an infrared absorption spectrum, and the reaction was continued until absorption of the isocyanate group disappeared.

The urethane prepolymer and other (meth) acrylates thus obtained were used for producing an acrylic conductive curable resin composition described later. The molecular weight of the urethane prepolymer was determined by using a GPC system (SC-8010 manufactured by Tosoh Corporation) or the like and creating a calibration curve with commercially available standard polystyrene to obtain a weight average molecular weight (M
w).

(Example 1) A cold-rolled steel sheet was cut and pressed, and spot-welded to form a depression in the cold-rolled steel sheet. A test piece was used. Acrylic conductive curable resin compositions to be filled in the depressions of the test pieces were prepared according to the compositions shown in Tables 1 to 7. Note that 1,1-bis (t-butylperoxy) cyclohexane was used as a thermal polymerization initiator, and Ketjen Black was used as a conductive filler.

After the acrylic conductive curable resin composition was filled in a recess of a test piece as shown in FIG. 2, an oven (trade name "PH-20" manufactured by Tabai Espec Co.) at 150.degree.
0 ") for 1 minute to cure. After cooling to room temperature, the structure of the title test sample was obtained. The following evaluation tests were performed on the obtained structure and the cured product of the acrylic conductive curable resin composition, and the results are shown in Tables 1 to 7 including the overall evaluation. With regard to the overall evaluation, very good ones were evaluated as good, excellent ones were evaluated as poor, and bad ones were evaluated as poor.

[0051] <Test Method> 1. Volume resistivity of acrylic conductive curable resin composition
Acrylic conductive curable resin composition prepared as a sample for measuring the ratio was prepared according to JIS K-6911 with a diameter of 10
It was cured to 0 mm and 2 mm thick. Thereafter, a digital ultra-high resistance / micro ammeter (R8340 type) and a resistance chamber (R127) manufactured by Advantest Co., Ltd.
02A), and the volume resistivity of the cured product was measured at an applied voltage of 100 V.

[0052] 2. Electrodeposition test The structure of the test sample obtained in Example 1 was subjected to a degreasing treatment with an alkaline solution (pH 11 to 13) and a chemical conversion treatment with a phosphoric acid solution (pH 3) as a pretreatment step, followed by washing with water. Thereafter, a test piece that had been applied with a DC voltage of 200 V and a current of 20 A was immersed in an emulsion composed of an amine-added epoxy resin and a block-added isocyanate curing agent as an electrodeposition paint for about 30 minutes to perform electrodeposition.
Thereafter, baking was performed in a hot air dryer at 180 ° C. for 30 minutes. The electrodeposition paintability was visually evaluated, and the case where the electrodeposition paint was coated on the cured product in the same manner as the steel sheet was evaluated as "O", and the case where the electrodeposition paint was not coated or where the coating was clearly thinner than the steel sheet surface was evaluated as "X".

[0053] 3. Acrylic conductive curable resin composition
Tensile breaking elongation and tensile elastic modulus Tensile breaking elongation and tensile elastic modulus were measured based on JIS K-7113. However, the acrylic conductive curable resin composition of the measurement sample was cured at 150 ° C. for 10 minutes to produce a thermosetting resin plate, and was machined from the thermosetting resin plate to form a 1 mm-thick 1 mm. The shape was the shape of a No. test piece. The test speed was speed C (5 mm / mm ± 20%).

[0054] 4. Workability / Abrasiveness Test of Structure The structure of the test sample obtained in Example 1 was finished and polished with a disk sander, and the degree of polishing of the cured body of the acrylic conductive curable resin composition was observed. The case where the polishing condition of the cured product was good was evaluated as ○, the case where the cured product was slightly abraded was Δ, and the case where the cured product was melted due to frictional heat and was excessively removed was evaluated as x. In addition, when the acrylic conductive curable resin composition applied to the vertical surface before curing was dripped by its own weight, it was evaluated as x.

[0055] 5. As a sample for a fatigue test of a structure, a bench fatigue test was performed on a structure obtained by removing an excessive portion after heat curing. FIG.
Is a schematic view when the structure is set on a bench fatigue tester (model EHF-EB01, manufactured by Shimadzu Corporation). The structure is fixed to a support, and a load is periodically applied by a vibrating rod. I have. The test is performed in the direction perpendicular to the plane of the test piece.
The test was performed by applying a displacement of 100 kg at a rate of 20 Hz per minute. Regarding the evaluation, the number of vibrations until cracks or cracks were visually measured with the upper limit of 100,000 times, and when there was no abnormality up to 100,000 times, ○: When there was no abnormality after 10,000 times, The case where cracks and the like occurred before reaching 10,000 times was evaluated as x.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

[0060]

[Table 5]

[0061]

[Table 6]

[0062]

[Table 7]

[0063]

According to the present invention, a cured product using the acrylic conductive curable resin composition of the present invention can provide a structure which can be subjected to electrodeposition coating or electrostatic coating. The cured body according to the present invention has a feature that the surface of the joint and the filling portion and the surface of the panel component can be uniformly finished because the surface of the structure can be smoothed by cutting and polishing the joint and the joint. INDUSTRIAL APPLICABILITY The present invention can exert a greater effect when used as a filler in a joint groove of a panel part such as an automobile body, an electric device, and a housing or an adhesive at a joint.

[Brief description of the drawings]

FIG. 1 is a plan view and a sectional view of a test piece used for a test sample.

FIG. 2 is a plan view and a cross-sectional view of a structure in which the test sample of FIG. 1 is filled with an acrylic conductive curable resin composition.

FIG. 3 is a plan view schematically showing a bench fatigue tester.

[Explanation of symbols]

 1, steel plate piece 3 acrylic conductive curable resin composition 4 support 5, 6 vibrating bar

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C25D 13/12 B05D 1/04 B05D 1/36 B05D 7/14 B62D 65/00

Claims (3)

(57) [Claims] 1. A cured product having a volume resistivity of 1.0 × 10
A structure joined or filled with an acrylic conductive curable composition of ⁶ Ωcm or less, and the surfaces of the structure and the curable composition are electrodeposited or electrostatically coated. The structure characterized by the above. 2. The cured product of the acrylic conductive curable composition has a tensile elongation at break of 10 to 70% and a tensile modulus of 1 to 70.
The structure according to claim 1, wherein the weight is 150 kg / mm ² . 3. An acrylic conductive curable resin composition wherein the conductive filler is carbon black.
Or the structure of claim 2.