JP5652955B2 - Coating composition and coating film forming method - Google Patents

Description

  The present invention relates to a coating composition and a method for forming a coating film, which are excellent in low-temperature curability (100 ° C. or less) and can form a coating film excellent in adhesion, water resistance and conductivity on a plastic substrate such as a bumper. .

For the bumpers, fenders, radiator grills, etc. on the outer panel of automobile bodies, polyolefins that are lightweight and have excellent moldability are used in place of metals, and plastics are used to improve cosmetics and durability. Topcoat is applied.
However, since the surface of polyolefin is nonpolar and its adhesion to the coating film is not sufficient, chlorinated polyolefin (hereinafter abbreviated as CPO) is used in the coating composition in order to improve adhesion to the plastic substrate. In some cases).
In the coating composition, a curing agent is blended for the purpose of improving the solvent resistance of the coating film. In such a coating composition, the chlorinated polyolefin has a low polarity and the curing agent has a high polarity, so the compatibility is insufficient due to the difference in polarity, and the adhesion and water resistance of the formed coating film are reduced. There was a problem.

In order to improve the above problems, acrylic resins and polyester resins produced by random copolymerization as compatible resins with chlorinated polyolefins may be blended into the coating composition. It was insufficient.
For example, a copolymerizable unsaturated monomer (a) selected from methacrylic acid and methacrylic acid ester, and a copolymerizable unsaturated monomer (b) are copolymerized to produce a macromonomer, and then co-polymerized with the macromonomer. A coating composition comprising an acrylic resin obtained by copolymerization reaction with a polymerizable unsaturated monomer (c), a mixture of a chlorinated polyolefin resin, and / or a reaction product is disclosed ( Patent Document 1). However, in the coating composition disclosed in Patent Document 1, the stability of the coating is improved, but the low-temperature curability and adhesion of the formed coating film are insufficient.

  Also disclosed is an aqueous primer composition for plastic molded articles comprising a chlorinated polyolefin (A), a polyurethane dispersion (B), an active methylene block polyisocyanate compound (C), and, if necessary, an acrylic resin (D). (Patent Document 2). However, the composition disclosed in Patent Document 2 also has insufficient low-temperature curability.

  Moreover, the primer composition for coating materials containing the polymer composition (C) obtained by polymerizing the radically polymerizable monomer (A) in the presence of the macromonomer (B) having a polymerizable unsaturated group is disclosed. (Patent Document 3). However, the primer composition for paint disclosed in Patent Document 3 has insufficient low-temperature curability, adhesion, and water resistance.

In addition, it contains (A) a pyrazole block polyisocyanate compound and (B) a hydroxyl group-containing resin having a hydroxyl value of 10 to 250 mgKOH / g and a weight average molecular weight of 1,000 to 200,000. A coating composition is disclosed (Patent Document 4). However, only the coating composition using the pyrazole block polyisocyanate compound described in Patent Document 4 has insufficient adhesion and water resistance.
Further, it is a block copolymer comprising (meth) acrylic acid 4-t-butylcyclohexyl (a) unit and a monomer (b) unit other than the (a) unit, wherein the (a) unit is An acrylic resin containing a polymer block (A) containing 90% by mass or more and a polymer block (B) containing 90% by mass or more of the (b) unit is disclosed (Patent Document 5). However, 4-t-butylcyclohexyl (meth) acrylate described in Patent Document 5 sometimes has a high viscosity at room temperature or lower, and is difficult to handle at the time of production and has a problem in workability.

JP 2002-348526 A JP 2004-307684 A JP-A-2005-97435 JP 2005-225907 A JP 2009-256457 A

An object of the present invention is to provide a coating composition having a low temperature curability (100 ° C. or less) on a plastic substrate such as a bumper and capable of forming a coating film having good adhesion, water resistance and electrical conductivity. It is in. Another object of the present invention is to provide a method for forming a coating film on a plastic substrate using the coating composition.

As a result of intensive studies to solve the above problems, the present inventors have found that a specific acrylic resin (A), a polyolefin resin (B) which may be chlorinated, an active methylene block polyisocyanate compound (C), a conductive material. The present invention was completed by finding that this problem can be solved by using an organic solvent-type coating composition containing a functional filler (D) and a silane coupling agent (E) at a specific blending ratio. The present invention provides the following coating composition and a method for forming a coating film using the coating composition.
That is, the present invention
1. Acrylic resin (A) having the following characteristics, polyolefin tree (B) which may be chlorinated, pyrazole block polyisocyanate compound and / or active methylene block polyisocyanate compound (C), conductive filler (D) and silane coupling A coating composition containing the agent (E) , wherein the component (A) is 10 to 50 parts by mass per 100 parts by mass of the total solid content of the component (A), the component (B), and the component (C). ) Component 20-60 parts by mass, (C) Component 5-30 parts by mass , (D) Component 1-200 parts by mass, and (E) Component 1-20 parts by mass, and an organic solvent type paint. Composition,
Acrylic resin (A): at least one methacrylate (a11) selected from cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, dicyclopentenyl methacrylate, dicyclopentanyl methacrylate, and 2-ethylhexyl methacrylate Is homopolymerized or copolymerized in the presence of 2,4-diphenyl-4-methyl-1-pentene, or copolymerized with methacrylate (a11) and other ethylenically unsaturated monomer (a12). The weight average molecular weight obtained by copolymerizing the hydroxyl-containing ethylenically unsaturated monomer (a2) and the other ethylenically unsaturated monomer (a3) to the macromonomer (a1) obtained in this manner is 3,000 to 100,000. And hydroxyl group 10 to 150 mg KOH / g of resin, and the value of part by weight of methacrylate (a11) / (total part by weight of methacrylate (a11) and other ethylenically unsaturated monomer (a12)) is 0.5 to 1.0. Resin
2. On the surface of the plastic substrate, the coating composition described in 1 is applied, baked if necessary, then a colored base paint is applied, and baked if necessary, and then a clear paint is applied and baked. A method of forming a coating film,
A coated article by the method for forming a coating film according to 3.2 .

  The coating composition of this invention discovered the coating composition which has low temperature curability and can form a coating film with favorable adhesiveness and water resistance on a plastic base material. Furthermore, according to the coating composition using a conductive filler, for example, a carbon nanotube, good conductivity can be imparted to a plastic substrate by blending a small amount of a conductive ferrule. Therefore, conductivity can be imparted to the coating film without adversely affecting the finish and design properties.

  The acrylic resin (A) of the present invention comprises a low-polar structure site obtained by using a macromonomer (a1) using a relatively large amount of methacrylate (a11) having a relatively large number of carbon atoms, a hydroxyl group-containing ethylenically unsaturated monomer ( It has both highly polar structural sites obtained by using a2). By blending the acrylic resin (A) having such characteristics, the affinity for the polyolefin resin (B), which may have a chlorinated low-polar structure portion, is improved, and the high-polar structure portion is pyrazole block poly Since the affinity for the isocyanate compound and / or the active methylene block polyisocyanate compound (C) is improved, adhesion to the material, water resistance and low-temperature curability are improved in the coating film formed by the coating composition. Estimated.

Below, the coating composition and coating-film formation method of this invention are demonstrated in order.

Acrylic resin (A):
The acrylic resin (A) contains at least one methacrylate (a11) selected from cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, dicyclopentenyl methacrylate, dicyclopentanyl methacrylate, and 2-ethylhexyl methacrylate. ) Is homopolymerized or copolymerized in the presence of 2,4-diphenyl-4-methyl-1-pentene, or copolymerized with methacrylate (a11) and other ethylenically unsaturated monomer (a12). And a macromonomer (a1) obtained by copolymerizing a hydroxyl group-containing ethylenically unsaturated monomer (a2) and another ethylenically unsaturated monomer (a3).
The macromonomer (a1) is at least one selected from cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, dicyclopentenyl methacrylate, dicyclopentanyl methacrylate, and 2-ethylhexyl methacrylate as essential components. The methacrylate (a11) is homopolymerized or copolymerized in the presence of 2,4-diphenyl-4-methyl-1-pentene, or, if necessary, the methacrylate (a11) and other ethylenic groups. It is obtained by copolymerizing with a saturated monomer (a12), and the value of part by weight of methacrylate (a11) / (total part by weight of methacrylate (a11) and other ethylenically unsaturated monomer (a12)) is 0.5-1.0 Preferably from 0.8 to 1.0. By being in this range, a coating film having excellent adhesion and water resistance can be obtained.

  The blending amount of 2,4-diphenyl-4-methyl-1-pentene (sometimes abbreviated as “α-methylstyrene dimer”) is that of methacrylate (a11) and other ethylenically unsaturated monomers (a12). In order to obtain a coating film excellent in adhesion and water resistance, it is preferably in the range of 1 to 40% by mass, preferably 2 to 20% by mass, based on the total mass.

  Examples of other ethylenically unsaturated monomers (a12) used as necessary include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, n -Octyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, tridecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, etc. Acrylic acid esters that may contain a ring structure having 1 to 24 carbon atoms; methyl methacrylate, ethyl methacrylate Ring structures having 1 to 24 carbon atoms such as isopropyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, n-octyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, stearyl methacrylate, isostearyl methacrylate Methacrylic acid esters which may contain; aromatic ring-containing vinyl compounds such as styrene, vinyl toluene and α-methylstyrene; vinyl esters such as vinyl propionate and vinyl acetate; acrylonitrile, methacrylonitrile; Acrylamide; glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, vinylcyclohexene monoepoxide, N-glycidyl Epoxy group-containing vinyl compounds such as acrylamide and allyl glycidyl ether; aminoethyl (meth) acrylate, Nt-butylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylamino Ethyl (meth) acrylate, N, N-dipropylaminoethyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl Amino group-containing (meth) acrylates such as (meth) acrylate; N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dipropylaminoethyl (meth) acrylamide , N, N Amino group-containing (meth) acrylamides such as dimethylaminopropyl (meth) acrylamide; 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole, 4- (meth) acryloyloxy-1, UV-absorbing functional groups or UV-stable functional group-containing vinyl compounds such as 2,2,6,6-pentamethylpiperidine; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, A polyhydric alcohol such as glyceryl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, N-hydroxyethyl (meth) acrylamide, polyethylene glycol mono (meth) acrylate, and acrylic acid or methacrylic acid. Hydroxylated vinyl compounds such as nonesterified products and reaction products of these with ε-caprolactone; carboxyls such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, reaction products of hydroxyl group-containing compounds and acid anhydrides Group-containing vinyl compounds; and acid anhydride group-containing vinyl compounds such as maleic anhydride, itaconic anhydride, and hymic anhydride. These can be used alone or in combination of two or more. In this specification, “(meth) acrylate” and “(meth) acrylamide” mean “acrylate or methacrylate” and “acrylamide or methacrylamide”, respectively. Hydroxyl group-containing vinyl compounds and carboxyl group-containing vinyl compounds may be used as necessary for adjustment of compatibility and the like, but if too much, adhesion to the substrate may be lowered. Based on the total mass of (a11) and the other ethylenically unsaturated monomer (a12), 5% by mass or less is preferable, and 3% by mass or less is more preferable.

  Examples of the polymerization method include a method of simply heating to 130 to 250 ° C. and performing thermal polymerization, or a method of adding a radical polymerization initiator and heating to a temperature of 60 to 250 ° C. In the polymerization, an organic solvent can be used as necessary.

  Examples of organic solvents include hydrocarbon solvents such as heptane, cyclohexane, toluene, xylene, octane, mineral spirits; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate Solvents: ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, s-butanol, isobutanol; dioxane, ethylene glycol monoethyl ether, ethylene Ether solvents such as glycol monobutyl ether and propylene glycol monopropyl ether; Swazol 31 manufactured by Cosmo Oil , Mention may be made of Swasol 1000, aromatic petroleum solvents such as Swasol 1500. These organic solvents can be used alone or in combination of two or more. When using an organic solvent, it is normally used in the range which becomes 400 mass% or less based on the total mass of a methacrylate (a11) and another ethylenically unsaturated monomer (a12).

  The radical polymerization initiator is not particularly limited, and examples thereof include ketone peroxides such as cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (t-butyl Peroxyketals such as peroxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate Hydroperoxides such as cumene hydroperoxide and 2,5-dimethylhexane-2,5-dihydroperoxide; di-t-butyl peroxide, di-t-amyl peroxide, bis (1,1- Dimethylbutyl) peroxide, 3-bis (t-butylpa Dialkyl peroxides such as oxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diisopropylbenzene peroxide, t-butylcumyl peroxide; decanoyl peroxide , Diacyl peroxides such as lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide; peroxycarbonates such as bis (t-butylcyclohexyl) peroxydicarbonate; t-butylperoxybenzoate, t Organic peroxide polymerization initiators such as peroxyesters such as butylperoxy-2-ethylhexanoate and 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, and 2,2 '-Azobisisobutyroni Ril, 2,2'-azobis (2-methylbutyronitrile) (also known as: azobismethylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) (also known as azobisdimethylvaleronitrile) Azo polymerization initiators such as 1,1′-azobis (cyclohexane-1-carbonitrile), azocumene 2,2′-azobismethylvaleronitrile, 4,4′-azobis (4-cyanovaleric acid), and the like Mention may be made of redox initiators such as a mixture of t-butyl hydroperoxide and sodium erythorbate.

Although the usage-amount of these radical polymerization initiators is not specifically limited, Usually, 0.1-30 mass% based on the total mass of a methacrylate (a11) and another ethylenically unsaturated monomer (a12). Preferably, it is 0.3-15 mass%.
Although the macromonomer (a1) thus obtained varies depending on the type and amount of the methacrylate (a11) and other ethylenically unsaturated monomers (a12) used, it is 0.3 to 2 on an average per molecule. It has a polymerizable unsaturated bond, preferably 0.5 to 1 polymerizable unsaturated bond. The macromonomer (a1) may have an acid value or a hydroxyl value as necessary for adjusting the compatibility. The acid value and the hydroxyl value are not particularly limited, but if it is too high, the adhesion to the substrate may be lowered. Therefore, the resin acid value is preferably 50 mgKOH / g or less, and the hydroxyl value is 40 mgKOH / g or less. preferable. The macromonomer preferably has a weight average molecular weight of (a1) in the range of 500 to 100,000, particularly 1,000 to 50,000.

Next, the macromonomer (a1) produced as described above is further mixed with a hydroxyl group-containing ethylenically unsaturated monomer (a2) and another ethylenically unsaturated monomer (a3) to conduct a polymerization reaction, thereby obtaining an acrylic resin. (A) can be obtained.
Examples of the hydroxyl group-containing ethylenically unsaturated monomer (a2) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glyceryl (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, Examples thereof include monoesterified products of polyhydric alcohols such as N-hydroxyethyl (meth) acrylamide and polyethylene glycol mono (meth) acrylate and acrylic acid or methacrylic acid, and reaction products of these with ε-caprolactone. These can be used alone or in combination of two or more.

  Other ethylenically unsaturated monomers (a3) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl ( (Meth) acrylate, t-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) Acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth ) Acrylic acid or methacrylic acid esters which may contain a ring structure having 1 to 24 carbon atoms such as acrylate; vinyl compounds containing aromatic rings such as styrene, vinyltoluene and α-methylstyrene; vinyl propionate, vinyl acetate Carboxyl group-containing vinyl compounds such as acrylonitrile, methacrylonitrile; (meth) acrylamide; acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, hydroxyl group-containing compounds and acid anhydride reaction products Class; vinyl compounds containing acid anhydride groups such as maleic anhydride, itaconic anhydride, and hymic anhydride; glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, vinylcyclohexene monoepoxide, N-glycidyl Acrylamide , Epoxy group-containing vinyl compounds such as allyl glycidyl ether; aminoethyl (meth) acrylate, Nt-butylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (Meth) acrylate, N, N-dipropylaminoethyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl ( Amino group-containing (meth) acrylates such as (meth) acrylate; N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dipropylaminoethyl (meth) acrylamide, N, N-dimethylamino Amino group-containing (meth) acrylamides such as propyl (meth) acrylamide; 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole, 4- (meth) acryloyloxy-1,2, Examples include UV-absorbing functional groups such as 2,6,6-pentamethylpiperidine or vinyl compounds containing UV-stable functional groups. These can be used alone or in combination of two or more.

  In addition, as a compounding ratio of the said macromonomer (a1), a hydroxyl-containing ethylenically unsaturated monomer (a2), and another ethylenically unsaturated monomer (a3), (a1) component, (a2) component, and (a3) component (A1) component is 5 to 80 parts by mass, preferably 20 to 50 parts by mass, and (a2) component is 5 to 40 parts by mass, preferably 10 to 30 parts by mass, A range of 0 to 85 parts by mass, preferably 20 to 70 parts by mass of the component a3) is also preferable in order to obtain a coating film excellent in adhesion and water resistance.

  Examples of the polymerization method include a method in which a mixture of the macromonomer (a1), the hydroxyl group-containing ethylenically unsaturated monomer (a2) and the other ethylenically unsaturated monomer (a3) is heated to 130 to 250 ° C. and thermally polymerized, Or the method of adding a radical polymerization initiator and heating to the temperature of 60 to 250 degreeC is mentioned. In the polymerization, an organic solvent can be used as necessary. Examples of organic solvents include hydrocarbon solvents such as heptane, cyclohexane, toluene, xylene, octane, mineral spirits; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate Solvents: ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, s-butanol, isobutanol; dioxane, ethylene glycol monoethyl ether, ethylene Ether solvents such as glycol monobutyl ether and propylene glycol monopropyl ether; Swazol 31 manufactured by Cosmo Oil Aromatic petroleum solvents such as 0, Swazol 1000, Swazol 1500 and the like can be mentioned.

  These organic solvents can be used alone or in combination of two or more. When an organic solvent is used, the range is usually 400% by mass or less based on the total mass of the macromonomer (a1), the hydroxyl group-containing ethylenically unsaturated monomer (a2), and the other ethylenically unsaturated monomer (a3). Used in.

  The radical polymerization initiator is not particularly limited, and examples thereof include ketone peroxides such as cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (t-butyl Peroxyketals such as peroxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate Hydroperoxides such as cumene hydroperoxide and 2,5-dimethylhexane-2,5-dihydroperoxide; di-t-butyl peroxide, di-t-amyl peroxide, bis (1,1- Dimethylbutyl) peroxide, 3-bis (t-butylpa Dialkyl peroxides such as oxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diisopropylbenzene peroxide, t-butylcumyl peroxide; decanoyl peroxide , Diacyl peroxides such as lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide; peroxycarbonates such as bis (t-butylcyclohexyl) peroxydicarbonate; t-butylperoxybenzoate, t Organic peroxide polymerization initiators such as peroxyesters such as butylperoxy-2-ethylhexanoate and 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, and 2,2 ′ -Azobisisobutyronite 2,2′-azobis (2-methylbutyronitrile) (also known as azobismethylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile) (also known as azobisdimethylvaleronitrile), Azo polymerization initiators such as 1,1′-azobis (cyclohexane-1-carbonitrile), azocumene 2,2′-azobismethylvaleronitrile, 4,4′-azobis (4-cyanovaleric acid), and t- Mention may be made of redox initiators such as a mixture of butyl hydroperoxide and sodium erythorbate.

  Although the usage-amount of these radical polymerization initiators is not specifically limited, The total mass of a macromonomer (a1), a hydroxyl-containing ethylenically unsaturated monomer (a2), and another ethylenically unsaturated monomer (a3). Is usually 0.1 to 30% by mass, preferably 0.3 to 15% by mass.

  The acrylic resin (A) thus obtained has a weight average molecular weight of 3,000 to 100,000, preferably 5,000 to 50,000, a hydroxyl value of 10 to 150 mgKOH / g, and a hydroxyl value of 30 to 120 mgKOH / g.

Polyolefin resin (B) which may be chlorinated:
Examples of the polyolefin resin (B) that may be chlorinated in the present invention include polyolefin resin, chlorinated polyolefin resin, etc., and improved adhesion to polyolefin-based materials such as automobile outer plates and exterior parts such as automobile bumpers. Use for. When using chlorinated polyolefin resin, the chlorination rate is 50 mass% or less, Preferably it is 10-45 mass%, More preferably, it is 15-30 mass%. A polyolefin resin and a chlorinated polyolefin resin may be used in combination.

  Examples of the polyolefin resin include one or more polymers selected from ethylene, propylene, butene, and methylbutene, and these olefins and vinyl acetate, butadiene, acrylate esters, methacrylate esters, and maleic anhydride. And radical copolymers with styrene and the like. Moreover, after manufacturing polyolefin resin, the modified polyolefin resin which made the vinyl-type monomer react with a post process may be sufficient, and as a vinyl-type monomer, alkyl (meth) acrylate, hydroxyalkyl (meth) acrylate, glycidyl ( Additives of meth) acrylate, styrene, glycidyl (meth) acrylate and monocarboxylic acid, adducts of maleic anhydride and hydroxyalkyl (meth) acrylate, acrylic acid, methacrylic acid, maleic anhydride, maleic acid and fumaric acid, etc. Is mentioned. When a vinyl monomer is reacted, a known radical generator may be used in combination.

  Examples of the chlorinated polyfin resin include a maleic anhydride-modified chlorinated polyolefin resin obtained by reacting maleic anhydride after producing a chlorinated polyolefin resin or a chlorinated polyolefin resin. By using a maleic anhydride-modified polyolefin resin and / or a chlorinated polyolefin resin, it is possible to improve adhesion to a polyolefin resin molded article and paint stability.

  The polyolefin resin and the chlorinated polyolefin resin may have a functional group such as a hydroxyl group or a carboxyl group in the molecule, and the weight average molecular weight is 1,000 to 300,000, particularly 3,000 to 150,000. The range of is suitable.

The blending ratio of the acrylic resin (A) and the optionally chlorinated polyolefin resin (B) in the present coating composition is 10 to 90% by mass of the acrylic resin (A) based on the total solid content of both components. Preferably, the range of 30 to 80% by mass, and the optionally chlorinated polyolefin (B) is 90 to 10% by mass, preferably 70 to 20% by mass. From the viewpoint of sex.
Compound (C)
The coating composition of the present invention contains a pyrazole block polyisocyanate compound and / or an active methylene block polyisocyanate compound (C).
The compound (C) is specifically obtained by reacting an isocyanate group of a polyisocyanate compound with a pyrazole compound or an active methylene compound. The polyisocyanate compound is a compound having two or more free isocyanate groups in one molecule. For example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate, xylylene diisocyanate (XDI), metaxylylene diisocyanate, tetramethylene Aliphatic, alicyclic, aromatic such as diisocyanate, hexamethylene diisocyanate (HMDI), lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate, dimer acid diisocyanate System polyisocyanate compounds.

  Further, isocyanurate type polyisocyanates, burette type polyisocyanates, uretdione type polyisocyanates, urethane type polyisocyanates, allophanate type polyisocyanates and the like using these polyisocyanate compounds are also included. Examples of the polyhydric alcohol used in the urethane type polyisocyanate include ethylene glycol, propylene glycol, butanediol, hexanediol, trimethylolpropane, glycerin, pentaerythritol, acrylic polyol, polyether polyol, and polyester polyol.

  Examples of the active methylene compound for blocking the isocyanate group of these polyisocyanate compounds include malonic acid diesters and acetoacetic acid esters. Malonic acid diesters include dimethyl malonate, diethyl malonate, diisopropyl malonate, di-n-propyl malonate, di-n-butyl malonate, ethyl n-butyl malonate, methyl n-butyl malonate, and ethyl t malonate. -Butyl, methyl t-butyl malonate, diethyl methyl malonate, dibenzyl malonate, diphenyl malonate, benzyl methyl malonate, ethyl phenyl malonate, t-butyl phenyl malonate, isopropylidene malonate and the like. Examples of the acetoacetate include methyl acetoacetate, ethyl acetoacetate, isopropyl acetoacetate, n-propyl acetoacetate, t-butyl acetoacetate, n-butyl acetoacetate, benzyl acetoacetate and phenyl acetoacetate. One or more of these can be used.

  As a blocking agent, some of these active methylene compounds may be replaced with blocking agents such as alcohols, phenols, acid amides, imidazoles, pyridines, mercaptans, oximes, amines and the like. it can. The active methylene block polyisocyanate compound may be a compound obtained by reacting an active methylene compound with a polyisocyanate compound to form a block, and then reacting with an alcohol to effect transesterification. On the other hand, examples of the pyrazole compound include 3,5-dimethylpyrazole, 3-methylpyrazole, 4-nitro-3,5-dimethylpyrazole and 4-bromo-3,5-dimethylpyrazole. Among these, a preferable blocking agent is 3,5-dimethylpyrazole.

  In addition, as a blocking agent, a part of the pyrazole compound can be substituted with blocking agents such as alcohols, phenols, acid amides, imidazoles, pyridines, mercaptans, oximes, and amines.

  The reaction between the polyisocyanate compound and the active methylene compound is usually performed in the presence of a catalyst. The catalyst used here is preferably a basic compound, for example, a metal alcoholate such as sodium methylate, sodium ethylate, sodium phenolate, potassium methylate, tetraalkylammonium, tetraethylammonium, tetrabutylammonium, etc. Ammonium hydroxide, organic weak acid salts such as acetate, octylate, myristate and benzoate, alkali metal salts of alkylcarboxylic acids such as acetic acid, caproic acid, octylic acid and myristic acid, and the above alkyl Examples thereof include metal salts of carboxylic acids such as tin, zinc and lead, aminosilyl group-containing compounds such as hexamethylene disilazane, and alkali metal hydroxides such as lithium, sodium and potassium. The amount of the catalyst used is suitably 0.01 to 5% by mass, particularly 0.1 to 2% by mass, based on the polyisocyanate compound. After the reaction of the polyisocyanate compound and the active methylene compound, part or all of the used catalyst may be neutralized as necessary. The reaction between the polyisocyanate compound and the active methylene compound or the pyrazole compound can be performed with or without a solvent, and is generally preferably performed at a temperature of 0 to 150 ° C, particularly 30 to 100 ° C.

  The proportion of each component used is 10 for the acrylic resin (A) based on 100 parts by mass of the total solid content of the acrylic resin (A) and the polyolefin resin (B) which may be chlorinated and the compound (C). -50 parts by mass, preferably 20-45 parts by mass, optionally chlorinated polyolefin resin (B) is 20-60 parts by mass, preferably 25-50 parts by mass, and compound (C) is 5-30 parts by mass. The amount is preferably 10 to 25 parts by mass.

  When the amount of the acrylic resin (A) is less than 10 parts by mass, the coating stability is inferior. On the other hand, when it exceeds 50 parts by mass, the coating film becomes hard and the adhesion to the material may be lowered. Further, if the amount of the polyolefin resin (B) which may be chlorinated is less than 20 parts by mass, the adhesion to the material may be lowered, whereas if it exceeds 60 parts by mass, the coating stability may be inferior. is there. Further, when the amount of the compound (C) is less than 5 parts by mass, the low temperature curability may be inferior, and when it exceeds 30 parts by mass, the coating stability may be inferior. Subsequently, a conductive filler (D) and a silane coupling agent (E) can be mix | blended as needed.

Conductive filler (D)
The conductive filler (D) of the coating composition of the present invention is contained as necessary, and by allowing the coating film to have conductivity, it enables electrostatic coating on the coating film. Is.
The conductive filler (D) is not particularly limited as long as it can impart conductivity to the coating film to be formed, and any shape of particles, flakes, and fibers (including whiskers) can be used. can do. Specific examples include conductive carbon such as conductive carbon black, carbon nanotube, carbon nanofiber, and carbon microcoil; metal powder such as silver, nickel, copper, graphite, and aluminum, and further doped with antimony. Tin oxide coated with phosphorus, tin oxide doped with phosphorus, acicular titanium oxide surface coated with tin oxide / antimony, antimony oxide, zinc antimonate, indium tin oxide, carbon and graphite whiskers coated with tin oxide, etc. At least one conductive selected from the group consisting of tin oxide, antimony-doped tin oxide, tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide and nickel oxide on the flake-like mica surface Pigment coated with conductive metal oxide; diacid Such as pigments having conductive containing tin oxide and phosphorus on the particulate titanium surface and the like, which can be used either alone or in combination of two or more. Of these, conductive carbon, particularly carbon nanotubes, can be preferably used.

  Examples of the carbon nanotube include ordinary carbon nanotubes, that is, single-walled carbon nanotubes, multi-walled carbon nanotubes in which several layers are concentrically overlapped, and those in which these are coiled.

  The carbon nanotube will be described in more detail. A cylinder with rounded graphite-like carbon atoms with a thickness of several atomic layers is a single-layer or multiple-nested structure, and is an extremely small substance with an outer diameter on the order of nm. is there.

  As the carbon nanotube, a carbon nanohorn having a shape in which one side of the carbon nanotube is closed, a cup-shaped nanocarbon substance having a hole in the head, and the like can also be used. In addition, fullerene, metal-encapsulated fullerene, onion-like fullerene, carbon nanofiber, vapor grown carbon (VGCF), peapod, carbon nanoparticle, and the like, which are analogs of carbon nanotubes, can also be used.

  Carbon nanotube production methods include catalytic hydrogen reduction of carbon dioxide, arc discharge method, laser evaporation method, CVD method, vapor phase growth method, gas phase flow method, and carbon monoxide reacted at high temperature and pressure with iron catalyst. A HiPco method for growing in a gas phase can be used. The carbon nanotubes obtained by the production method are preferably single-walled carbon nanotubes or multi-walled carbon nanotubes.

As the carbon nanotubes, carbon nanotubes that are highly purified by various purification methods (washing method, centrifugal separation method, filtration method, oxidation method, chromatographic method, etc.) are preferable because various functions can be sufficiently expressed. . Carbon nanotubes are pulverized using a ball-type kneader (ball mill, vibration mill, sand mill, roll mill, etc.), etc., and are then cut short by chemical and physical treatment. Can also be used. As a commercially available product of carbon nanotubes, CNTD-317 (developed product; carbon nanotube concentration of 1.0 wt% manufactured by Gokoku Dye Co., Ltd.) can be mentioned.
When blending such a conductive filler (D), the content thereof is 1 to 200 based on 100 parts by mass of the total solid content of the acrylic resin (A), the polyolefin resin (B) and the compound (C). A part by mass, preferably 2 to 100 parts by mass, more preferably 5 to 80 parts by mass is good in terms of paint stability and conductivity.
In particular, when the carbon nanotube is used, it is 1 to 15 parts by mass, preferably 1 to 15 parts by mass based on the total solid content of 100 parts by mass of the acrylic resin (A), polyolefin resin (B) and compound (C). 10 mass parts, More preferably, 1-7 mass parts is desirable.

Silane coupling agent (E)
Examples of the silane coupling agent (E) include β? (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriexylsilane, γ-aminopropyltrimethoxysilane, γ-aminopropyl Triethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, bis ( Riethoxysilylpropyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane, γ-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (vinylbenzylamine) -β-aminoethyl-γ -Aminopropyltrimethoxysilane and the like,
These 1 type can be used individually or in mixture of 2 or more types. As commercially available products, KBM-402, KBM-403, KBM-502, KBM-503, KBM-603, KBE-903, KBM-603, KBE-602, KBE-603 (all trade names) manufactured by Shin-Etsu Silicone Co., Ltd. ) Etc. can be used.

  The content of the silane coupling agent (E) is 1 to 20 parts by mass, preferably 2 to 20 parts by mass based on 100 parts by mass in total of the solid contents of the acrylic resin (A), the polyolefin resin (B) and the compound (C). 15 parts by mass, more preferably 3 to 10 parts by mass, for example, in a coated article in which polypropylene (bumper) and other materials (nylon, glass fiber reinforced plastic, etc.) are integrated, simultaneously improve the adhesion of both materials It is desirable from the aspect.

  In the coating composition of the present invention, if necessary, a polyester resin, a urethane resin, an acrylic resin other than the acrylic resin (A), a phenol resin, a polyether compound, an epoxy resin, a blocked polyisocyanate compound other than the compound (C), It is also possible to add compounds used in ordinary paints such as curing catalysts, anti-sagging agents, anti-repelling agents, pigments and the like.

  As the curing catalyst, a Lewis acid, an amine compound, or an onium salt can be used. Lewis acids include diacetyltin diacetate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, diacetyltin dioctoate, tin octylate, dibutyltin diacetate and dibutyltin dioctoate, such as organic tin compounds; zinc octylate, Examples include organic zinc compounds such as zinc stearate, zinc oxalate, zinc naphthenate, and zinc 2-ethylhexanoate; organic zirconium compounds such as zirconium tetraacetylacetonate. Examples of amine compounds include triethylenediamine, triethylamine, N, N, N ′, N′-tetramethylpropylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N-methylmorpholine, , 2-dimethylimidazole, 1,5-diaza-bicyclo (4,3,0) nonene-5, 1,8-diazabicyclo (5,4,0) -undecene-7 (hereinafter sometimes abbreviated as DBU) Etc. Examples of the onium salt include DBU phenol salt, DBU octylate, DBU carbonate, tetrabutylammonium chloride, tetrabutylammonium bromide and the like. Of these, Lewis acids are preferred for reasons such as catalytic activity, and organotin compounds are particularly preferred.

Examples of the pigment include titanium oxide, carbon black, chrome lead, ocher, yellow iron oxide, Hansa Yellow, pigment yellow, chrome orange, chrome vermillion, permanent orange, amber, permanent red, brilliant carmine, fast violet, and methyl violet lake. Color pigments such as ultramarine, bitumen, cobalt blue, phthalocyanine blue, pigment green and naphthol green; extender pigments such as barita, tancal and clay; one or two or more of these can be used.
Although it does not specifically limit as a use, For example, primer for plastic parts, such as a car bumper, a coating material, a chipping primer, a metal corrosion prevention coating material etc. are mentioned.
Coating film forming method On the plastic substrate, the coating composition of the present invention obtained above is applied and baked as necessary, and then a colored base coating is applied and baked as necessary. A multilayer coating film can be formed by painting and baking a paint. Although it does not specifically limit as a plastic base material, For example, the various plastic members etc. which are used for the outer plate | board part of motor vehicles, such as a bumper, a spoiler, a grill, and a fender, the outer plate | board part of household appliances, etc. are mentioned.

As a material for the plastic substrate, for example, a polyolefin obtained by polymerizing at least one selected from olefins having 2 to 10 carbon atoms such as ethylene, propylene, butylene, and hexene is particularly preferable, but is not limited thereto. Instead, a material such as polycarbonate, ABS resin, ASA resin, carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), urethane resin, or nylon may be used. Further, these plastic substrates can be appropriately subjected to degreasing treatment, water washing treatment and the like in advance by a method known per se.
In addition, as a coating method of the coating composition of this invention, it can select and use suitably from well-known coating methods, However, Usually, it carries out by an air spray, an airless spray, etc.

Baking and hardening of the coating composition of the present invention can be omitted as long as it does not cause an abnormality such as a mixed layer between coating layers or a coating film, and may be selected from coating methods such as 3C1B, 3C2B, and 3C3B. The coating film thickness is 5 to 30 μm, the base coating film is 10 to 25 μm, and the clear coating film is 20 to 50 μm, and the baking conditions at each stage may be the same or different. Conventionally known drying means can be used, for example, by air blow, infrared heating, far infrared heating, induction heating, dielectric heating, etc., at a temperature of 60 to 110 ° C., preferably 70 to 100 ° C. for 20 to 40 minutes. A multilayer coating film can be formed by heating and curing.
As the coating of the colored base paint and the clear paint, spray coating is generally used. If the coating composition of the present invention contains a conductive filler and can form a conductive film, the colored base paint and the clear paint The coating can use electrostatic coating.

  Further, the base coating film and the clear coating film may each be a multilayer of two or more layers. The colored base paint and clear paint used here may be one-pack type or two-pack type, and may be solvent-based paint or water-based paint. Moreover, there is no restriction | limiting in particular as a resin type used for the coating composition of this invention, For example, a polyester resin, an acrylic resin, an epoxy resin, a polyurethane resin, a polyolefin resin etc. can be used.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In each example, “parts” indicates mass parts, and “%” indicates mass%.

Production Example 1 Acrylic resin no. Example 1 (Example)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2 parts, cyclohexyl methacrylate 28 parts, di-t-amyl peroxide 1.5 parts Was reacted at 155 ° C. under nitrogen gas to give a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 1 was obtained.
Next, 88 parts of toluene, 20.5 parts of hydroxyethyl methacrylate, 51.5 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 85 mgKOH / g, a weight average molecular weight of 10, 000 acrylic resin No. 1 was obtained.

Production Example 2 Acrylic resin no. Example 2 (Example)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2 parts, cyclohexyl methacrylate 25 parts, n-butyl methacrylate 3 parts, di-t- 1.5 parts of amyl peroxide was reacted at 155 ° C. under nitrogen gas to obtain macromonomer No. 2,000 having a weight average molecular weight of 2,000. 2 was obtained.
Next, 88 parts of toluene, 20.5 parts of hydroxyethyl methacrylate, 51.5 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 85 mgKOH / g, a weight average molecular weight of 10, 000 acrylic resin No. 2 was obtained.

Production Example 3 Acrylic resin no. 3 Production Example (Example)
Swazol 1000 (Cosmo Oil, aromatic solvent) 28 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2.7 parts, isobornyl methacrylate 45.5 parts, isobornyl acrylate 2 .5 parts and 2 parts of di-t-amyl peroxide were reacted at 155 ° C. under nitrogen gas to give a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 3 was obtained.
Next, 77 parts of toluene, 12 parts of hydroxyethyl methacrylate, 40 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain an acrylic resin having a hydroxyl value of 49 mgKOH / g and a weight average molecular weight of 10,000. No. 3 was obtained.

Production Example 4 Acrylic resin no. Example 4 (Example)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2.4 parts, isobutyl methacrylate 24 parts, styrene 3 parts, di-t-amyl A macromonomer No. having a weight average molecular weight of 2,000 was reacted with 1.8 parts of peroxide at 150 ° C. under nitrogen gas. 4 was obtained. Next, 88 parts of toluene, 21 parts of hydroxyethyl methacrylate, 47 parts of cyclohexyl methacrylate, 5 parts of 2-ethylhexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas, and the hydroxyl value was 87 mgKOH / g, weight average. Acrylic resin no. 4 was obtained.

Production Example 5 Acrylic resin no. 5 Production Example Swazol 1000 (Cosmo Oil, aromatic solvent) 16 parts 2,4-diphenyl-4-methyl-1-pentene (MSD) 2.4 parts, t-butyl methacrylate 27 parts, t-butyl By reacting 2.2 parts of peroxy-2-ethylhexanoate under nitrogen gas at 130 ° C., macromonomer No. 2,000 having a weight average molecular weight of 2,000 was obtained. 5 was obtained.
Next, 88 parts of toluene, 21 parts of hydroxyethyl methacrylate, 47 parts of isobornyl methacrylate, 5 parts of cyclohexyl acrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 86 mgKOH / g, weight average Acrylic resin no. 5 was obtained.

Production Example 6 Acrylic resin no. 6 Production Example Swazol 1000 (Cosmo Oil, aromatic solvent) 16 parts 2,4-diphenyl-4-methyl-1-pentene (MSD) 1.7 parts, dicyclopentenyl methacrylate 28 parts, di-t -1.3 parts of amyl peroxide were reacted at 155 ° C under nitrogen gas to obtain a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 6 was obtained.
Next, 87 parts of toluene, 15 parts of hydroxyethyl methacrylate, 57 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain an acrylic resin having a hydroxyl value of 62 mgKOH / g and a weight average molecular weight of 10,000. No. 6 was obtained.

Production Example 7 Acrylic resin no. Production Example 7 Swazol 1000 (Cosmo Petroleum, aromatic solvent) 16 parts 2,4-diphenyl-4-methyl-1-pentene (MSD) 1.7 parts, dicyclopentanyl methacrylate 28 parts, di- A macromonomer No. having a weight average molecular weight of 2,000 was reacted with 1.3 parts of t-amyl peroxide at 155 ° C. under nitrogen gas. 7 was obtained.
Next, 87 parts of toluene, 17.5 parts of hydroxyethyl methacrylate, 3 parts of hydroxypropyl acrylate, 46.5 parts of cyclohexyl methacrylate, 5 parts of styrene, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl group. No. 85 mg KOH / g, weight average molecular weight 10,000 acrylic resin No. 7 was obtained.

Production Example 8 Acrylic resin no. 8 Production Examples Swazol 1000 (Cosmo Oil, aromatic solvent) 16 parts 2,4-diphenyl-4-methyl-1-pentene (MSD) 1.7 parts, 2-ethylhexyl methacrylate 27 parts, di-t -Reaction of 1.2 parts of amyl peroxide under nitrogen gas at 155 ° C to give a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 8 was obtained.
Subsequently, 87 parts of toluene, 21 parts of hydroxyethyl methacrylate, 52 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain an acrylic resin having a hydroxyl value of 87 mgKOH / g and a weight average molecular weight of 10,000. No. 8 was obtained.

Production Example 9 Acrylic resin no. 9 Production Examples Swazol 1000 (Cosmo Oil, aromatic solvent) 16 parts 2,4-diphenyl-4-methyl-1-pentene (MSD) 0.28 parts, cyclohexyl methacrylate 28 parts, di-t-amyl 1.5 parts of peroxide were reacted at 155 ° C. under nitrogen gas to obtain a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 9 was obtained.
Subsequently, 86 parts of toluene, 20.5 parts of hydroxyethyl methacrylate, 51.5 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 86 mgKOH / g, a weight average molecular weight of 10, 000 acrylic resin No. 9 was obtained.

Production Example 10 Acrylic resin no. 10 production examples Swazol 1000 (Cosmo Oil, aromatic solvent) 24 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 3.5 parts, isobutyl methacrylate 20 parts, t-butyl methacrylate 20 Part, 3.2 parts of t-butylperoxy-2-ethylhexanoate were reacted at 130 ° C. under nitrogen gas to obtain a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 9 was obtained.
Next, 82 parts of toluene, 25 parts of hydroxyethyl methacrylate, 35 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain an acrylic resin having a hydroxyl value of 100 mgKOH / g and a weight average molecular weight of 10,000. No. 10 was obtained.
Table 1 shows the contents of these production examples 1 to 10.

Comparative Production Example 1 Acrylic resin no. 11 production examples (comparative examples)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2 parts, cyclohexyl methacrylate 5.5 parts, methyl methacrylate 22 parts, t-butyl par 1.9 parts of oxy-2-ethylhexanoate were reacted at 100 ° C. under nitrogen gas to obtain a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 11 was obtained.
Next, 88 parts of toluene, 20.5 parts of hydroxyethyl methacrylate, 52 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 85 mgKOH / g and a weight average molecular weight of 10,000. Acrylic resin no. 11 was obtained.

Comparative Production Example 2 Acrylic resin no. 12 production examples (comparative examples)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2 parts, cyclohexyl methacrylate 11 parts, methyl methacrylate 16.5 parts, t-butyl par 1.9 parts of oxy-2-ethylhexanoate were reacted at 100 ° C. under nitrogen gas to obtain a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 12 was obtained.
Next, 88 parts of toluene, 20.5 parts of hydroxyethyl methacrylate, 52 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain a hydroxyl value of 85 mgKOH / g and a weight average molecular weight of 10,000. Acrylic resin no. 12 was obtained.

Comparative Production Example 3 Acrylic resin no. 13 production examples (comparative examples)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 28 parts, 85 parts of toluene, 80 parts of cyclohexyl methacrylate, 20 parts of hydroxyethyl methacrylate and 4 parts of azobismethylbutyronitrile were reacted at 110 ° C. under nitrogen gas to produce a hydroxyl group. No. 84 mg KOH / g, weight average molecular weight 10,000 acrylic resin No. 13 was obtained.

Comparative Production Example 4 Acrylic resin no. 14 production examples (comparative examples)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 28 parts, 85 parts of toluene, 70 parts of cyclohexyl methacrylate, 30 parts of hydroxyethyl methacrylate and 4 parts of azobismethylbutyronitrile were reacted at 110 ° C. under nitrogen gas to form a hydroxyl group. No. 125 mg KOH / g, weight average molecular weight 10,000 acrylic resin No. 14 was obtained.

Comparative Production Example 5 Acrylic resin no. 15 production examples (comparative examples)
Swazol 1000 (manufactured by Cosmo Oil, aromatic solvent) 16 parts, 2,4-diphenyl-4-methyl-1-pentene (MSD) 2 parts, cyclohexyl methacrylate 28 parts, di-t-amyl peroxide 1.5 parts Was reacted at 155 ° C. under nitrogen gas to give a macromonomer No. 2,000 having a weight average molecular weight of 2,000. 1 was obtained.
Subsequently, 88 parts of toluene, 72 parts of cyclohexyl methacrylate, and 1 part of azobisdimethylvaleronitrile were reacted at 95 ° C. under nitrogen gas to obtain an acrylic resin No. 1 having a hydroxyl value of 0 mg KOH / g and a weight average molecular weight of 10,000. 15 was obtained.
Table 2 shows the contents of the above Comparative Production Examples 1 to 5.

Production Example 11 Curing Agent No. Preparation Example 1 Into a flask, 151 parts of Desmodur N-3300 (manufactured by Sumika Bayer Urethane Co., Ltd., trade name, polyisocyanate isocyanate content 21.6%) was charged, and 76 parts of 3,5-dimethylpyrazole was added while stirring. It added little by little and was made to react at 100-105 degreeC. Thereafter, 47 parts of n-butanol and 50 parts of toluene were added, and it was confirmed that the reaction rate of the isocyanate group was 99% or more. 1 was obtained.

Production Example 12 Curing Agent No. In Example 2 flask, 151 parts of Desmodur N-3300, 60 parts of toluene, and 140 parts of di-n-butyl malonate were added, and 1.4 parts of 28% methanol solution of sodium methoxide was added thereto. The reaction was carried out at 70 ° C. for 8 hours under air flow. Thereafter, 63 parts of n-butanol was added and aged at 70 ° C., and it was confirmed that the reaction rate of isocyanate was 99% or more. 2 was obtained.

Production Example 13 Curing Agent No. Production Example 3 No. 3 in Production Example 11 except that 69 parts of 2-butanone oxime was used instead of 3,5-dimethylpyrazole. 3 was obtained.

Examples, reference examples and comparative examples
Reference Example 1 Paint composition No. 1
50 parts (solid content) of Supercron 892L (Note 1), acrylic resin no. 1 in 30 parts (solid content), curing agent no. 1 in 20 parts (solid content), 20 parts of Vulcan XC72 (Note 3) and 80 parts of JR-806 (Note 5) are mixed and dispersed in a mixed solvent of xylene / toluene = 1/1 (weight ratio). Second / Ford Cup # 4 / coating composition No. adjusted to 20 ° C. 1 was obtained.

Reference Examples 2-10, 12, 13 Examples 11, 14, 15 Coating Composition No. 2-No. 15
A coating composition No. 1 was prepared in the same manner as in Reference Example 1 except that the contents of Tables 3 and 4 were used. 2-No. 15 was obtained.

(Note 1) Supercron 892L: trade name, manufactured by Nippon Paper Chemical Co., Ltd., acid-modified chlorinated polypropylene, chlorination rate 22%, solid content 20%.

(Note 2) Super Clon 851L: trade name, manufactured by Nippon Paper Chemicals, acid-modified chlorinated polypropylene, chlorination rate 22%, solid content 20%.

  (Note 3) Vulcan XC72: trade name, manufactured by Cabot Specialty Chemicals, conductive carbon black.

  (Note 4) CNTD-317: developed product name, product of Mikuni Dye Co., Ltd., carbon nanotube ethyl acetate dispersion, concentration 1.0 wt.

  (Note 5) JR-806: trade name, manufactured by Teika, rutile titanium oxide.

  (Note 6) KBM-402: manufactured by Shin-Etsu Silicone, trade name, silane coupling agent.

(Note 7) Paint stability:
Each coating composition No. 1-No. 23 was examined for the presence or absence of separation, sedimentation, and thickening of the coating composition after storage at 30 ° C. for 30 days.
◎: no separation, sedimentation or thickening
○: At least one of separation, sedimentation, and thickening can be seen, but there is no problem returning to it by hand stirring.
Δ indicates separation, sedimentation, and thickening, and stirring with a motor is required for redispersion for 1 hour or more.

Comparative Examples 1-6 Coating composition No. 16-No. 21
A coating composition No. 1 was prepared in the same manner as in Example 1 except that the contents of Table 5 were used. 16-No. 21 was obtained.

Substrate A
A degreased polypropylene plate (70 × 150 × 3 mm) was used.

Substrate B
A degreased nylon plate (70 × 150 × 3 mm) was used.
Test plate creation
Reference Example 16
The above-mentioned coating composition No. 1 is spray-coated to a film thickness of 10 μm, set at room temperature for 10 seconds, and soflex 420 (trade name, colored base paint, manufactured by Kansai Paint Co., Ltd.) is formed to a film thickness of 15 μm as a colored base paint. Was electrostatically painted.
Next, “Soflex # 500 Clear” (trade name, acrylic urethane organic solvent-type clear paint manufactured by Kansai Paint Co., Ltd.) is applied as a clear paint to a film thickness of 30 μm and left at room temperature for 5 minutes. Then, it was heated at 95 ° C. for 30 minutes to obtain a multilayer coating film. The multilayer coating film was subjected to adhesion and water resistance tests.

Reference Examples 17-25, 27, 28 and Examples 26, 29, 30
Coating composition No. A test plate was obtained in the same manner as in Reference Example 16 except that the coating composition described in Tables 6 and 7 was used instead of 1. Each coating composition and the multilayer coating film were evaluated according to the following test methods.

Comparative Examples 7-12
Coating composition No. A test plate was obtained in the same manner as in Example 16 except that the coating composition shown in Table 8 was used instead of 1. The coating composition and the coating film were evaluated according to the following test methods.

(Note 8) Surface electrical resistance value: Each coating composition is applied, set at room temperature, and after 5 minutes, the surface electrical resistance value of the coating film is measured with an electrical resistance measuring instrument (trade name “MODEL150”, TREK). It was measured.
◎ indicates a surface resistance value of less than 1 MΩ / □ 〇 indicates a surface resistance value of 1 MΩ / □ or more and less than 100 MΩ / □ Δ indicates a surface resistance value of 100 MΩ / □ or more and less than 10000 MΩ / □ 10,000 MΩ / □ or more.

  (Note 9) Adhesiveness: 100 pieces of 2 mm wide goblet cuts made with a cutter so as to reach the base of each multilayer coating film obtained in the preparation of the test plate, and adhesive tape was adhered to the surface, at 20 ° C. The remaining number of the goby eye coatings after the rapid peeling was observed.

◎: remaining number / total number = 100/100, no missing edges ○: remaining number / total number = 100/100, no edges missing Δ: remaining number / total number = 99 to 90 / 100 pieces x: remaining number / total number = 89 or less / 100 pieces.

  (Note 10) Water resistance: In each multi-layer coating film obtained in the preparation of the test plate, after being immersed in warm water at 40 ° C. for 240 hours, cut with a cutter so as to reach the substrate, and make 100 2 mm wide gobangs. The adhesive tape was adhered to the surface, and the remaining number of the goby-eyed coating film was observed after abrupt peeling at 20 ° C.

◎: remaining number / total number = 100/100, no missing edges ○: remaining number / total number = 100/100, no edges missing Δ: remaining number / total number = 99 to 90 / 100 pieces x: remaining number / total number = 89 or less / 100 pieces.

  The present invention can provide a coated article excellent in low-temperature curability, conductivity, adhesion, water resistance, and conductivity with respect to a plastic substrate such as a bumper.

Claims (3)

Acrylic resin (A) having the following characteristics, polyolefin tree (B) which may be chlorinated, pyrazole block polyisocyanate compound and / or active methylene block polyisocyanate compound (C), conductive filler (D) and silane coupling A coating composition containing the agent (E) , wherein the component (A) is 10 to 50 parts by mass per 100 parts by mass of the total solid content of the component (A), the component (B), and the component (C). ) Component 20-60 parts by mass, (C) Component 5-30 parts by mass , (D) Component 1-200 parts by mass, and (E) Component 1-20 parts by mass, and an organic solvent type paint. Composition.
Acrylic resin (A): at least one methacrylate (a11) selected from cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, dicyclopentenyl methacrylate, dicyclopentanyl methacrylate, and 2-ethylhexyl methacrylate Is homopolymerized or copolymerized in the presence of 2,4-diphenyl-4-methyl-1-pentene, or copolymerized with methacrylate (a11) and other ethylenically unsaturated monomer (a12). The weight average molecular weight obtained by copolymerizing the hydroxyl-containing ethylenically unsaturated monomer (a2) and the other ethylenically unsaturated monomer (a3) to the macromonomer (a1) obtained in this manner is 3,000 to 100,000. And hydroxyl group 10 to 150 mg KOH / g of resin, and the value of part by weight of methacrylate (a11) / (total part by weight of methacrylate (a11) and other ethylenically unsaturated monomer (a12)) is 0.5 to 1.0. Resin A coating composition according to claim 1 is applied onto the surface of a plastic substrate, baked as necessary, then a colored base coating is applied, baked as necessary, and then a clear coating is applied. A coating film forming method characterized by baking. The coated article by the coating-film formation method of Claim 2 .