JP2003275676A - Repair method and substrate for automotive coatings - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an automobile repair painting method capable of reducing costs and shortening the repair painting process and the working time by omitting the painting process of a repair undercoat paint (primer surfacer). provide. SOLUTION: A step (1) of applying a putty material, a step (2) of applying a repair base paint, a step (3) of polishing the coating film formed in the above step (2), and the repair base paint A method for repairing automotive coatings, comprising the step of applying (4), wherein the repair base paint is a quick-drying coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing an automobile coating film and a substrate.

[0002]

2. Description of the Related Art An automobile body, parts, and the like are usually coated with an electrodeposition coating having a high rust-preventive property, an intermediate coating formed on the electrodeposition coating, and A multi-layer coating film formed of an overcoat coating film formed on the intermediate coating film is formed.

When the automobile coating film thus formed has a defect due to an accident or the like, repair coating is applied to the defective portion. This repair coating is generally done by polishing the defective part of the automobile coating film with an abrasive, etc., and then the undercoat paint for repair (primer / surfacer), the base paint for repair, and if necessary repair It has been done by sequentially applying clear paints for use.

In this repair coating, usually, after applying a base coating for repair (primer / surfacer), the applied coating is dried, the surface of the coating film formed after drying is polished, and the surface after polishing is further polished. After the degreasing process was performed, the repair base paint was applied.

However, in this conventional repair coating, the time for performing the steps of coating, drying, polishing, and degreasing the above-mentioned undercoat paint for repair (primer / surfacer) is 30 to 50% of the total process time spent for the repair coating. However, the time required for repair painting was inevitably long. Further, an undercoat paint for repair (primer / surfacer) and materials for drying and polishing are additionally required, which is a problem in terms of cost.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned present situation, the present invention is an undercoat paint for repair (primer / surfacer).
It is an object of the present invention to provide an automobile repair painting method that can reduce the cost and shorten the repair painting process and working time by omitting the painting process of (1).

[0007]

According to the present invention, a step (1) of applying a putty material, a step (2) of applying a repair base paint, and a step of polishing the coating film formed by the above step (2). A method for repairing an automobile coating film, comprising the step (3) and the step (4) of applying the repairing base coating material, wherein the repairing base coating material is a quick-drying coating material. It is a repair method.

It is preferable that the method for repairing an automobile coating film further comprises a step (5) of applying a clear coating material for repair. The putty material is preferably a photocurable coating material.

The above photocurable coating composition comprises (a) a titanocene derivative, (b) a compound having a proton donating group, and
(C) a compound having at least one ethylenically unsaturated double bond, wherein the compound (b) has a proton donating group and (c) at least one ethylenically unsaturated double bond. Mass ratio with the compound
0.01: 99.99 to 20:80, and the above (b)
The amount of the (a) titanocene derivative is 0.01 to 10 parts by mass with respect to 100 parts by mass in total of the compound having a proton donating group and the compound (c) having at least one ethylenically unsaturated double bond. It is preferable that there is one.

The present invention is also a base material having a coating film obtained by the above-mentioned automobile coating film repairing method. Hereinafter, the present invention will be described in detail.

The method for repairing an automobile coating film of the present invention comprises a step (1) of applying a putty material, a step (2) of applying a base coating for repair, and a step of polishing the coating film formed by the step (2). It comprises the step (3) and the step (4) of applying the repair base paint.

In the method of repairing an automobile coating film of the present invention,
Before performing the step (1), the repair target portion of the coating film formed on the substrate is usually polished. The base material is not particularly limited, and includes, for example, metal, plastic,
It can be advantageously used for products such as foams. Of these, metal products that can be subjected to cationic electrodeposition coating are particularly preferably used.

The metal product is not particularly limited, and examples thereof include simple metals such as iron, copper, aluminum, tin and zinc, and alloys containing these simple metals.
For example, the bodies and parts of automobiles such as passenger cars, trucks, motorcycles and buses can be mentioned. It is particularly preferable that the metal product is previously subjected to chemical conversion treatment with a phosphate, a chromate or the like. On the steel sheet thus treated by chemical conversion, it is possible to further form an electrodeposition coating film by using a cation type or anion type electrodeposition coating, but since it gives a laminated coating film excellent in corrosion resistance, A cationic electrodeposition coating composition is preferred.

The plastic substrate is not particularly limited, and examples thereof include polypropylene resin, polycarbonate resin, urethane resin, polyester resin, polystyrene resin, ABS resin, vinyl chloride resin, polyamide resin and the like. , Spoilers, bumpers, mirror covers, grilles, door knobs, and other automobile parts. The above plastic product is preferably one that has been subjected to vapor cleaning with trichloroethane or cleaning with a neutral detergent, and may also be one that has been subjected to primer coating to enable electrostatic coating.

If necessary, a chemical conversion film, an electrodeposition coating film and a primer coating film are applied to the above-mentioned substrate, and then an intermediate coating film and a top coating film are usually formed in this order. The intermediate coating film is formed in order to conceal the base, to secure the surface smoothness after the top coating (improve the appearance), and to impart physical properties such as impact resistance and chipping resistance to the coating film. . The intermediate coating film is not particularly limited, but usually contains an organic or inorganic pigment, a pigment such as an extender pigment, a film-forming resin and a curing agent.

The above-mentioned top coating film comprises a base coating film and, if necessary, a clear coating film. The base coating film may be a metallic base coating film containing a bright pigment such as an aluminum pigment or a mica pigment,
A solid color coating film containing general coloring pigments instead of these bright pigments may be used. The method for forming these top coat films is not particularly limited, and examples thereof include spray coating and electrostatic coating.

The portion of the coating film to be repaired is usually polished with an abrasive such as sandpaper by so-called water polishing or air polishing with a gentle gradient. The polishing may be performed to such an extent that the undercoat coating film such as the intermediate coating film or the electrodeposition coating film of the repair target portion is exposed.

The step (1) is a step of applying a putty material to the polished portion obtained by the polishing. The step (1) can be performed by applying a putty material with a spatula or the like. After the application, the putty material is usually left to stand at room temperature for about 30 minutes to cure the applied putty material.
The surface of the putty is subjected to a chamfering treatment to make the surface smooth by so-called water polishing or air polishing using an abrasive such as sandpaper. By performing these, it is possible to fill the holes in the polished portion and to make the coated surface smooth.

The putty material is not particularly limited, and, for example, a conventional extender pigment and a putty prepared by kneading pigments with an appropriate color developing agent can be used. From the viewpoint of shortening the working time, the photocurable material is used. It is preferably a paint.

The photocurable coating material is not particularly limited as long as it is a UV, visible light and infrared light curable type.
From the viewpoint of thick film formation and working environment, visible light and / or near infrared light curing type is preferable, and visible light curing type is more preferable. As the above-mentioned photocurable coating material, one containing an unsaturated resin, an unsaturated monomer, a filler, a photopolymerization initiator or the like can be used.

The unsaturated resin is not particularly limited,
For example, a resin obtained by introducing a (meth) acrylate group, an allyl group or the like into a polyester resin, an epoxy acrylate resin, an acrylic resin, a urethane resin, an alkyd resin or the like can be mentioned. The unsaturated monomer is not particularly limited, and examples thereof include styrene, vinyltoluene, methyl methacrylate, diallyl phthalate and the like.

The above-mentioned filler can be arbitrarily selected from known inorganic / organic fillers. The inorganic filler is not particularly limited, and examples thereof include talc, dolomite, clay, kaolin, mica, mica, silica, aluminum silicate, calcium silicate, magnesium silicate, magnesium carbonate, barium sulfate, calcium oxide, magnesium oxide, titanium oxide. , Diatomaceous earth, metal powder, metal fiber, glass fiber, glass balloon and the like,
The organic filler is not particularly limited, and examples thereof include polyethylene powder, plastic balloons, rubber particles and the like. Further, in the case of a visible light curable type, it is preferable to use one of the above-mentioned fillers that does not interfere with the transmission of visible light in order to make it possible to cure a thicker film.

The above-mentioned photopolymerization initiator may be one that is excited by light energy in the UV, visible light or infrared light region, depending on the photocurable coating used. Examples thereof include camphorquinone, benzyl, 3-ketocoumarin, and the like, and examples of the near-infrared photopolymerization initiator include a combination of a complex of a cationic dye such as a cyanine dye and a boron-based sensitizer. be able to.

The above photo-curable coating composition is also disclosed in Japanese Patent Laid-Open No. 8-60.
No. 044, No. 9-137089, No. 9-157318, No. 9-176517, No. 9-241533, and No. 9-249.
It is also possible to use the coating compositions described in JP-A-831, JP-A-9-255707, JP-A-9-302262 and the like.

In the present invention, as the photocurable coating material, (a) a titanocene derivative, (b) a compound having a proton donating group, and (c) a compound having at least one ethylenically unsaturated double bond It is preferable that the photopolymerizable composition comprises The photopolymerizable composition is excellent in coating performance such as curability, adhesiveness and water resistance, and storage stability. In particular, when such a photopolymerizable composition is used as a photocurable coating, the drying time after coating can be shortened as compared with the case of using a normal putty. That is, when using a normal putty, while the drying time after coating takes several tens of minutes, when using the photopolymerizable composition, light irradiation of several tens of seconds to several minutes. Since it can be dried by the above, the working time of the step (1) can be significantly shortened.

As the (a) titanocene derivative, all known titanocene compounds can be used. For example, JP-A-59-152396 and JP-A-61-1.
Examples thereof include titanocene derivatives described in JP-A-51197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. As a specific example, bis (cyclopentadienyl) -di-chloro-
Titanium, bis (cyclopentadienyl) -di-phenyl-titanium, bis (cyclopentadienyl) -bis (2,3,4,5,6 pentafluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,6
Difluorophenyl) titanium, bis (methylcyclopentadienyl) -bis (2,3,4,5,6 pentafluorophenyl) titanium, bis (methylcyclopentadienyl) -bis (2,6difluorophenyl) titanium, Bis (cyclopentadienyl) -bis [2,6
-Difluoro-3- (2- (1-pyrr-1-yl) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3-((1-pyr-
1-yl) methyl) phenyl] titanium, bis (methylcyclopentadienyl) -bis [2,6-difluoro-3-((1-pyr-1-yl) methyl) phenyl] titanium, bis (cyclopentadi) (Enyl) -bis [2,
6-difluoro-3-((2,5-dimethyl-1-pyr-1-yl) methyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3
-((3-Trimethylsilyl-2,5-dimethyl-1-
Pyr-1-yl) methyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3-((2,5-bis (morpholinomethyl) -1-pyr-1-yl) Methyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-4-((2,5-dimethyl-1-pyr-1-yl) methyl) phenyl] titanium, bis (cyclopenta) Dienyl) -bis [2,6-difluoro-3-methyl-4-
(2- (1-Pyr-1-yl) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6
-Difluoro-3- (1-methyl-2- (1-pill-1
-Yl) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3-
(6- (9-carbazol-9-yl) hexyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (3- (4,5,6,7-
Tetrahydro-2-methyl-1-indol-1-yl)
Propyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3-((acetylamino) methyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro -3
-(2- (propionylamino) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,2
6-difluoro-3- (4- (bivaloylamino) butyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (2,2
-Dimethylpentanoylamino) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,2
6-difluoro-3- (3- (benzoylamino) propyl) phenyl] titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (N-
Allylmethylsulfonylamino) ethyl) phenyl] titanium, bis (cyclopentadienyl) -bis (2,2
6-difluoro-3- (1-pyr-1-yl) phenyl) titanium and the like can be mentioned. These may be used alone or in combination of two or more.

Examples of the compound (b) having a proton-donating group include so-called protic acids,
For example, an inorganic acid and an organic acid can be mentioned. The inorganic acid is not particularly limited, for example, hydrochloric acid, sulfuric acid,
Examples thereof include sulfonic acid, sulfinic acid, phosphoric acid, polyphosphoric acid, metaphosphoric acid, nitrous acid, nitric acid and boric acid.

Examples of the organic acid include those having at least one ethylenically unsaturated double bond in the molecule and those not having it. The compound having at least one ethylenically unsaturated double bond in the molecule is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and 2- (meth) acryloyl. Oxyethyl succinic acid,
2- (meth) acryloyloxyethyl phthalic acid, an acid anhydride modified compound of bisphenol A type epoxy acrylate, a phosphoric acid modified compound of bisphenol A type epoxy (meth) acrylate, phosphoric acid (meth) acrylates and the like can be mentioned. . Here, specific examples of the phosphoric acid (meth) acrylates include, for example, [CH _{2
= CRCOOCH 2 CH 2 [OCO (} CH 2) 6]
_a O] _b PO (OH) _{3 -b} , [CH ₂ = CRCOOC
H ₂ CH ₂ [OCH ₂ CH (CH ₃ )] _c O] _d PO
(OH) _3-b (R represents a hydrogen atom or a methyl group, a
And d represent 0 to 2, and b and c represent 1 or 2. )
Can be mentioned.

There is no particular limitation as to what does not have an ethylenically unsaturated double bond in the molecule, and examples thereof include acetic acid, butyric acid, oxalic acid, citric acid, lauric acid, stearic acid, malonic acid, adipic acid and tartaric acid. , Benzoic acid, salicylic acid, phthalic acid, monoethyl phosphate, monophenyl phosphate, diethyl phosphate, mono-2-ethylhexyl phosphate,
Examples thereof include di (2-ethylhexyl) phosphate, benzenesulfonic acid, dodecylbenzenesulfonic acid, toluenesulfonic acid and sulfobenzoic acid. Further, the compound having a proton-donating group may form a high molecular weight compound.

From the viewpoint of water resistance of the cured product, the compound (b) having a proton donating group preferably further has at least one ethylenically unsaturated double bond in the molecule, and When the substrate on which the photopolymerizable composition is applied is a metal, phosphoric acid (meth) acrylates are preferable in terms of adhesion. These may be used alone or in combination of two or more.

The compound (c) having at least one ethylenically unsaturated double bond is not particularly limited, and examples thereof include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and isobutyl. (Meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, phenyl (meth) acrylate, Phenoxyethyl (meth) acrylate,
Isobornyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, adamantyl (meth) acrylate, acryloylmorpholine, styrene, α-methylstyrene, t-butylstyrene, parachlorostyrene,
Vinylnaphthalene, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate,
Hydroxybutyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide,
Examples thereof include N-vinylformamide, N-vinylpyrrolidone; (meth) acrylate of ethylene oxide or propylene oxide adduct of polyhydric alcohol; reaction product of monofunctional glycidyl compound and (meth) acrylic acid.

A compound having two or more ethylenically unsaturated double bonds can also be used, and examples thereof include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate and tetraethylene glycol di (meth). ) Acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane Diol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate,
Dipentaerythritol poly (meth) acrylate,
Esters of polyhydroxy compounds such as 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane and (meth) acrylic acid; (meth) acrylates of ethylene oxide or propylene oxide adducts of polyhydric alcohols; Reaction products of poly (epoxy) compounds such as methylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, epichlorohydrin bisphenol type epoxy resin and (meth) acrylic acid; hexamethylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, 4,4 '
A urethane (meth) acrylate obtained from a polyisocyanate compound such as methylenebis (phenylisocyanate) and a hydroxyl group-containing (meth) acrylate; a urethane (meth) acrylate obtained from the above isocyanate compound, a polyester having a hydroxyl group at the terminal and a hydroxyl group-containing (meth) acrylate ) Acrylate; unsaturated polyester resin obtained from ethylenically unsaturated carboxylic acid or its anhydride and polyhydric alcohol; polybasic acid, polyhydric alcohol and (meth)
Examples thereof include polyester (meth) acrylate obtained from acrylic acid. These may be used alone,
You may use 2 or more types together.

In the method of repairing an automobile coating film of the present invention,
The putty material in the above step (1) is (a) a titanocene derivative, (b) a compound having a proton donating group, and
In the case of a photocurable coating composition comprising (c) a compound having at least one ethylenically unsaturated double bond, (b) the compound having a proton donating group and (c) the ethylenically unsaturated double bond The mass ratio of the compound having at least one bond is 0.01: 99.99 to 20:80, and the compound (b) having a proton donating group and the compound (c) ethylenically unsaturated double bond are used. The amount of the above-mentioned (a) titanocene derivative with respect to a total of 100 parts by mass with the compound having at least one is preferably 0.01 to 10 parts by mass. Outside these ranges, sufficient photocurability may not be obtained. When the compound (b) having a proton donating group further has at least one ethylenically unsaturated double bond, the compound (c) may not be included. This is because the compound (b) satisfies the requirement of the compound (c) that it has at least one ethylenically unsaturated double bond.

The photocurable coating material of the present invention comprises (a) a titanocene derivative, (b) a compound having a proton donating group, and (c) a compound having at least one ethylenically unsaturated double bond. When it is one, it may further contain a filler (d).

As the above-mentioned (d) filler, for example, the above-mentioned filler can be used. When the above (d) filler is contained, at least one (b) compound having a proton donating group and (c) an ethylenically unsaturated double bond are included.
The amount of the (d) filler is preferably 0.01 to 10 parts by mass, and (b) the compound having a proton donating group and (c) ethylene, with respect to 1 part by mass in total with the compound having one. The amount of the (a) titanocene derivative is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass in total of the compound having at least one unsaturated unsaturated double bond and the (d) filler. If the content of the filler is too small, sagging of the coating film and thinning of the meat may occur, which is not preferable. Also,
If it is too large, the viscosity of the curable coating material increases and the coating workability deteriorates, which is not preferable. Further, if it is out of the above range, sufficient photocurability may not be obtained.

The above-mentioned photocurable coating material may be further used, if necessary.
Coumarin dyes that can be used in combination with polymer binders, thermal polymerization inhibitors, water, organic solvents, pigments, dyes, titanocene derivatives,
A sensitizer such as a xanthene dye, a merocyanine dye, a benzopyran dye, or a radical generator may be included.

The photo-curable coating composition can be applied by a conventionally known method such as a spatula or a roller, and its film thickness is preferably about 0.1 to 10 mm. The coated surface is preferably shaped by a roller or the like so that a good finished surface can be obtained.

In the present invention, the coating film obtained by applying the above-mentioned photocurable coating material does not cover the surface thereof,
It can be cured by irradiation with light. By performing light irradiation without coating the coating film surface, there is no need to cover with a PET film or to form a liquid film with a temporary protective agent described in JP-A-10-34081, which simplifies the repair process. be able to. Even on a base material surface having a complicated shape such as a curved surface portion of a vehicle body bumper, deformation such as burrows and irregularities due to covering with a film does not occur.

The above-mentioned light irradiation can be appropriately selected from ultraviolet rays, visible rays, electron beams, X-rays, short-wavelength light, etc., depending on the type of photo-curable coating used. A point light source or a surface light source can also be used as the light source. Examples of the light source include a mercury lamp, a laser, a rare gas discharge lamp,
Examples thereof include metal halide lamps, halogen lamps, fluorescent lamps, carbon electrode arc lamps, argon incandescent lamps, electronic flash lamps, photographic floodlights, and light emitting diodes. Also, sunlight can be used as a light source. The irradiation time of the light irradiation can be appropriately selected depending on the purpose of use, the type and intensity of the lamp, but usually,
It takes several tens of seconds to several minutes.

In the present invention, the uncured portion can be removed with a solvent after curing by the above light irradiation. At the time of light irradiation, since the coating film surface is not covered, curing inhibition by oxygen in the air occurs, the coating film surface is in an uncured state, but by removing it with a solvent, simply and A coated surface having excellent smoothness can be obtained.

The above-mentioned solvent is not particularly limited as long as it can dissolve and remove the uncured portion and does not attack the cured coating film, and examples thereof include aromatic hydrocarbon solvents and aliphatic carbonized solvents. Examples thereof include organic solvents usually used for solvent-based paints such as hydrogen-based solvents, ester-based solvents and ketone-based solvents. In the present invention, since the repair coating can be shortened by the evaporation of the solvent, toluene, xylene,
Solvents having a high volatilization rate such as ethyl acetate, butyl acetate and methyl butyl ketone are preferred. Further, it may be a commercially available product, and examples thereof include degreasing agents such as “nax silicon off” manufactured by Nippon Paint Co., Ltd .; “nax admira thinner” and “nax superior thinner” or diluted thinners for paints. Diluted thinners for paints such as "nax admira thinner" and "nax superior thinner" are preferable in that the residue can be removed smoothly without leaving residue.

As a method for removing the above, cloth, sponge,
Examples of the method include a method in which paper or the like is soaked with the solvent and then wiped; a method in which the solvent is sprayed to remove the solvent. If desired, the coating film formed as described above may be subjected to a chamfering treatment for polishing the surface of the cured coating film to make it smooth.

The step (2) is a step of applying the repair base paint to the surface of the putty material formed in the step (1), and the repair base paint is a quick-drying paint. Conventionally, a two-component urethane resin paint having a low drying property has been mainly used as a repair paint, but the repair base paint of the present invention has a low drying property.
Since it is a quick-drying paint that has better drying properties than liquid-type urethane resin paints, the work time for repair painting can be greatly reduced. Further, the coating workability is good in that uneven coating is small, and as a result, a coating film having a good appearance can be formed.

Further, the method for repairing an automobile coating film of the present invention is as follows:
Since the quick-drying paint is used as the repair base paint in the step (2), it can be easily polished in the subsequent step (3), which shortens the working time. be able to. That is, when a base material for repairing having a low drying property, for example, a normal two-component urethane resin coating having a low drying property described above is used, it is difficult to polish it after coating,
If a quick-drying paint, for example, a one-pack type repair base paint described later is used, the working time can be shortened.

In the present invention, the quick-drying paint means that the repair base paint has a drying time at the same temperature as compared with the commonly used low-drying two-component urethane resin paint. Is short. In addition, as the repair base paint in the present invention, as long as it has a better drying property than the two-component urethane resin paint having a low drying property,
Both a one-pack type paint and a two-pack type paint can be used.

The repair base paint is not particularly limited as long as it has a better drying property than the two-component urethane resin paint having a low drying property, but a one-component paint is preferred. The two-component urethane resin coating with low drying property
It takes time and effort to mix the curing agent before painting, and the workability is not good, and the coating material mixed with the curing agent needs to be coated within a limited time, which also has a problem in storage. However, the repair base paint in the present invention is 1
A liquid type coating is preferable because it does not have such a problem.

In the above repair base paint, the one-pack type paint is, for example, a lacquer type paint containing cellulose acetate butyrate or nitrocellulose and an acrylic resin, a polyester resin, an epoxy resin or a melamine resin. I can list things.

Among the above-mentioned lacquer-type repair base paints, cellulose acetate butyrate and nitrocellulose are preferred from the viewpoint of excellent adhesion to a coating film (hereinafter referred to as an old coating film) already formed before repairing. Those containing an acrylic resin as an essential component are preferable.

The above-mentioned cellulose acetate butyrate is not particularly limited, and those usually used for paints can be used. However, the butyryl group content is 3
It is preferably 8% or more and has a viscosity of 0.01 second or more. When the butyryl group content is less than 38% or the viscosity is less than 0.01 seconds, the adhesion of the coating film formed by the repair base paint to the old coating film may not be sufficient. The viscosity here is ASTM D817
And the value measured according to D1343.

Examples of commercially available products of the above cellulose acetate butyrate include CAB-551-0.01 (viscosity = 0.01 seconds, butyryl group content = 53%), CAB.
-551-0.2 (viscosity = 0.20 seconds, butyryl group content = 52%), CAB-531-1 (viscosity = 1.90)
Sec, butyryl group content = 50%), CAB-500-5
(Viscosity = 5.00 seconds, butyryl group content = 51%), C
AB-553-0.4 (viscosity = 0.30 seconds, butyryl group content = 46%), CAB-381-0.1 (viscosity =
0.10 seconds, butyryl group content = 38%), CAB-3
81-0.5 (viscosity = 0.50 seconds, butyryl group content =
38%), CAB-381-2 (viscosity = 2.00 seconds, butyryl group content = 38%), CAB-381-2BP.
(Viscosity = 2.20 seconds, butyryl group content = 35.5
%), CAB-381-20 (viscosity = 20.00 seconds, butyryl group content = 37%), CAB-381-20BP
(Viscosity = 16.00 seconds, butyryl group content = 35.5
%), CAB-321-0.1 (viscosity = 0.10 seconds, butyryl group content = 31.2%), CAB-171-15.
S (viscosity = 15.00 seconds, butyryl group content = 17%)
(All are trade names, manufactured by Eastman Chemical Japan Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The above-mentioned nitrocellulose is not particularly limited, and known ones conventionally used in the paint field can be used. However, those having a viscosity of 1 second or more, particularly 2 to 60 seconds are preferable. If the viscosity of the nitrocellulose is less than 1 second, the adhesion of the coating film formed by the repair base paint to the old coating film may be insufficient. When the viscosity exceeds 60 seconds, the viscosity of the repair base paint becomes too high, which may deteriorate the workability of coating. In addition, the viscosity here means the value measured by JIS-K-6703.

Commercial products of the above nitrocellulose include
For example, HIG1 / 16 (viscosity = 1.0 to 1.5 seconds: measured at solid content 25.0%), HIG1 / 8 (viscosity = 2.
0-2.9 seconds: measured at a solid content of 25.0%), HIG1
/ 4 (viscosity = 3.0 to 6.0 seconds: measured at a solid content of 25.0%), HIG1 / 2 (viscosity = 3.0 to 4.9 seconds: measured at a solid content of 20.0%) , HIG1 (viscosity = 6.0-
8.0 seconds: measured at a solid content of 20.0%), HIG2 (viscosity = 1.5 to 2.5 seconds: measured at a solid content of 12.2%),
HIG7 (viscosity = 6.0 to 7.9 seconds: solid content 12.2%)
HIG20 (viscosity = 16.0 to 24.0)
Second: measured at solid content 12.2%), HIG60 (viscosity =
52.0 to 67.0 seconds: measured at a solid content of 12.2%)
(All are trade names, manufactured by Asahi Kasei Kogyo Co., Ltd.) and the like. These may be used alone or in combination of two or more.

The above-mentioned acrylic resin is a well-known styrene-based monomer, (meth) acrylic acid ester-based monomer, hydroxyl group-containing monomer, carboxyl group-containing monomer and other monomers, which are well known using an azo-based or peroxide-based polymerization initiator. It is obtained by polymerizing by a method. These may be used alone or in combination of two or more.

Examples of the styrene-based monomer include styrene, α-methylstyrene, vinyl ketone, t
-Butylstyrene, parachlorostyrene, vinylnaphthalene and the like can be mentioned.

Examples of the (meth) acrylic acid ester-based monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, phenyl acrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl methacrylate, t-butyl cyclohexyl acrylate,
Examples thereof include t-butylcyclohexyl methacrylate, dicyclopentadienyl acrylate, dicyclopentadienyl methacrylate, dihydrodicyclopentadienyl acrylate, dihydrodicyclopentadienyl methacrylate and the like.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and 4
-Hydroxybutyl acrylate and the like can be mentioned.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid,
Examples thereof include isocrotonic acid and acrylic acid dimer. Examples of the other monomer include, for example, a polymerizable amide (for example, acrylamide, methacrylamide,
N-methylolmethacrylamide, N-methoxymethylacrylamide, etc.), polymerizable nitriles (eg, acrylonitrile, methacrylonitrile, etc.), vinyl halides (eg, vinyl chloride, vinyl bromide, vinyl fluoride, etc.), α-olefins ( For example, ethylene, propylene, etc.), vinyl ester (eg, vinyl acetate, vinyl propionate, etc.), diene (eg, butadiene, isoprene, etc.) and the like can be mentioned.

Examples of the azo-based polymerization initiator include azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) and 2,2'-azobis (2,4-dimethylvalero). Nitrile) and the like. Examples of the peroxide-based polymerization initiator include benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide and t-butyl perbenzoate.

The weight average molecular weight of the acrylic resin is
It is preferably 50,000 or more, and 50,000 to 1
It is more preferably 00000. If it is less than 50,000, the water resistance of the resulting coating film may be reduced, and if it is more than 100,000, the viscosity of the coating becomes high,
Painting workability may be reduced.

The glass transition temperature of the acrylic resin is
The temperature is preferably room temperature or lower, and more preferably 25 ° C. or lower. If it exceeds 25 ° C, the adhesion of the coating film may be insufficient. The glass transition temperature here means a value obtained by a weighted average from the glass transition point and the compounding ratio peculiar to the monomers used for producing the acrylic resin.

It is preferable that the acrylic resin is compatible with the above-mentioned cellulose acetate butyrate and nitrocellulose. If the compatibility is poor, the stability of the coating composition may be reduced, and as a result, the coating may be deteriorated or the coating film may be glossed or the like to deteriorate the appearance of the coating film.

When the above repair base paint contains cellulose acetate butyrate, nitrocellulose, and acrylic resin as essential components, in addition to these essential components, pigment, organic solvent-based resin, It may contain various additives, solvents and the like.

As the pigment, those commonly used in the paint field can be used. Examples thereof include aluminum paste, pearl mica powder, graphite, micaceous iron oxide, phthalocyanine flakes, carbon black,
Aluminum pigments such as titanium white and phthalocyanine blue, color pigments and the like can be mentioned.

Examples of the organic solvent resin include alkyd resin, polyester resin, epoxy resin, melamine resin,
Examples thereof include silyl group-containing resin, cellulose acetate butyrate modified acrylic resin, nitrocellulose modified acrylic resin and the like. However, it is preferable to use such an organic solvent-based resin that has compatibility with the above-mentioned cellulose acetate butyrate, nitrocellulose, and acrylic resin. When an incompatible organic solvent-based resin is used, the stability of the coating decreases, and as a result,
As a result, there is a risk that lumps will be generated or that the coating film will be glossy and the appearance of the coating film will be impaired.

Examples of the above various additives include a surface conditioner, an ultraviolet absorber, an aluminum pigment settling inhibitor, a rheology control agent and the like. Further, as the solvent, toluene, xylene, ethyl acetate, butyl acetate,
Examples thereof include those normally used for paints such as methyl isobutyl ketone and butyl alcohol.
The above-mentioned pigment, organic solvent-based resin, various additives, solvent and the like may be used alone or in combination of two or more kinds.

In the repair base paint containing the above-mentioned cellulose acetate butyrate, nitrocellulose and acrylic resin as essential components, the content of cellulose acetate butyrate is 5 in terms of resin solid content.
The content of nitrocellulose is preferably 2.5% by mass or more, and the content of the nitrocellulose is preferably 2.5% by mass or more in terms of resin solid content. If each is less than the above lower limit, the coating film is likely to be cracked, and re-repairability by the coating film may be insufficient.

The total amount of the cellulose acetate butyrate and the nitrocellulose is 5 in terms of resin solid content.
It is preferably 5% by mass or less. If it exceeds 55% by mass, the viscosity of the coating composition becomes high and the coating workability may deteriorate. In addition, the adhesion and water resistance of the coating film decrease,
As a result, peeling of the coating film is likely to occur, and blisters are likely to occur in the coating film.

The content of the acrylic resin is preferably 25% by mass or more in terms of resin solid content, and is 25 to 25%.
It is more preferably 75% by mass. If it is less than 25% by mass, the adhesion of the coating film formed may be reduced. In addition, mass% in "resin solid content conversion" here
Means the mass% converted based on the total solid content of all resin components contained in the repair base paint. The contents of components other than the above-mentioned essential components can be appropriately set within a range that does not impair the performance of the repair base paint.

The above-mentioned repair base paint may be prepared by appropriately adjusting the repair paint primary color, or may be a commercially available product, and the latter may be, for example, "Nippon Paint Co., Ltd." Nax Admira "series and the like.

The method for applying the repair base paint can be appropriately selected depending on the depth and area of the repair target portion to be removed, and is not particularly limited, but, for example, a hand spray (air spray) is used. it can. The hand-blown spray is usually applied from a position 10 to 30 cm away from the object to be coated, and the solvent is easily volatilized during coating, and is suitable for local coating. Is preferably hand sprayed.

It is preferable that the repair base paint is applied three to four times. The repeated coating is performed without curing the coating film obtained by each coating. When the above-mentioned repair base paint is overcoated as described above, the dry film thickness of the coating film obtained by one coating is 3 to
It is preferably 12 μm. If the dry film thickness of the base coating film for repair by one-time coating is less than 3 μm, the film thickness may be too thin and film breakage may occur or the number of times of application may be increased. It is difficult to obtain a good appearance.
If it exceeds 12 μm, a difference in film thickness is likely to occur due to overcoating, the smoothness of the coating film surface is poor, and cracks and pinholes are likely to occur in the drying step.

In the method for repairing an automobile coating film according to the present invention, after the step (2), drying is usually performed. The above drying is
Usually, it can be carried out at room temperature to 80 ° C. for a lower limit of 60 seconds and an upper limit of 20 minutes. If it is less than the lower limit, curing may be insufficient and the physical properties of the coating film may be poor. Wasteful. The drying method is not particularly limited as long as it can be maintained at the above temperature, and for example, a method using hot air, infrared rays, or near infrared rays is used.

The dry film thickness of the repair base paint is usually 10 to 35 μm, though it depends on the depth of removing the repair target portion and the underlayer concealing property. If the upper limit is exceeded, the sharpness may be reduced, or defects such as unevenness and flow during coating may occur.If the lower limit is not reached, the unevenness of the base cannot be hidden,
Film breakage may occur.

The step (3) is a step of polishing the coating film formed in the step (2). By performing this polishing step, it is possible to eliminate the unevenness of the coating film formed in the above step (2) and improve the coating adhesion and the finished appearance after repair.

The method of polishing in the step (3) is not particularly limited as long as it is a method capable of eliminating irregularities on the surface of the coating film. For example, so-called water polishing or It can be done by sky polishing.

In the method for repairing an automobile coating film of the present invention, the above steps (2) and (3) are carried out before carrying out the step (4), while in the normal repair coating, the step (4) is carried out. )
Before carrying out, the process of painting, drying, polishing, and degreasing undercoat paint for repair (primer / surfacer) is performed.
Therefore, according to the method for repairing an automobile coating film of the present invention, the working time in the repair coating can be significantly shortened.

That is, in the above-mentioned normal repair coating, the coating time of the undercoat paint for repair (primer / surfacer) is about 2 to 10 minutes, and the drying time is 40 to 70 ° C.
The polishing time is about 30 to 60 minutes, the polishing time is about 2 to 10 minutes, and the degreasing time is about 1 to 2 minutes. In the method for repairing an automobile coating film of the present invention, the step (2) includes 2 to 10 minutes. About a minute, after the step (2), the drying time, if necessary, is 2 to
Since it takes about 3 minutes and about 2 to 10 minutes in the step (3), the method for repairing an automobile coating film according to the present invention can significantly reduce the working time as compared with a normal repair coating. ,
This allows more efficient repair painting.

In addition, in the normal repair coating, it is necessary to prepare not only the base paint for repair but also the undercoat paint for repair (primer surfacer). However, in the repair method of the automobile coating film of the present invention, the undercoat for repair is used. Material cost reduction because it is a method that can be repaired by applying the same base paint for repair in steps (2) and (4) without applying any paint (primer / surfacer) You can

The step (4) is a step in which the surface of the coating film is polished in the step (3) and then the repair base paint is applied. The repair base paint used in the step (4) is the same as that used in the step (2). By using the same paint, the cost spent for repair painting can be reduced. The method of applying the repair base paint in the step (4) can be performed in the same manner as the method of applying in the step (2).

In the method of repairing an automobile coating film according to the present invention, after the step (4), drying is usually performed. The drying after the step (4) can be performed in the same manner as the drying performed after the step (2) described above.

The dry film thickness of the coating film formed by the coating in the above step (4) is usually 20 to 35 μm, though it depends on the depth of removing the repair target portion and the underlayer concealing property. If it exceeds the upper limit, the sharpness of the image may be deteriorated, and defects such as unevenness and flow may occur at the time of coating, and if it is less than the lower limit, the unevenness of the underlayer cannot be hidden and film breakage may occur.

In the method for repairing an automobile coating film of the present invention, after carrying out the steps (1), (2), (3) and (4), a step (5) of applying a clear coating for repair is further carried out. It is preferable to do it.

The clear coating composition for repair contains a coating film-forming resin as a binder and, if necessary, a curing agent. The coating film-forming resin of the above-mentioned clear coating for repair is not particularly limited, and examples thereof generally include acrylic resin, polyester resin, alkyd resin, fluorine resin and the like. The curing agent is not particularly limited, and examples thereof include polyisocyanate compounds.

The method for applying the clear coating for repair can be performed in the same manner as the method for applying the base coating for repair. The dry film thickness of the above-mentioned clear coating for repair depends on the depth of removing the repair target portion and the undercoat hiding property, but is usually 20.
Is about 35 μm. If it exceeds the upper limit, the sharpness of the image may be deteriorated, and defects such as unevenness and flow may occur at the time of coating, and if it is less than the lower limit, the unevenness of the underlayer cannot be hidden and film breakage may occur.

When the clear coating for repair is applied after the base coating for repair in the step (4) is applied, it is forcibly dried by heating at 40 to 70 ° C. for about 30 to 60 minutes before coating. May be carried out, and a cured coating film having a high degree of crosslinking can be obtained by carrying out this step within an allowable time in terms of cost.

As described above, the method for repairing an automobile coating film of the present invention can form a coating film excellent in smoothness, easily and even on a substrate surface having a complicated shape. A substrate having such a coating film is also one aspect of the present invention.

In the method for repairing an automobile coating film of the present invention, the coating film formed by the step (1) of applying a putty material, the step (2) of applying a base coating material for repair, and the step (2) above is polished. A method for repairing an automobile coating film, comprising the step (3) and the step (4) of applying the repair base paint, wherein the repair base paint is a one-pack type paint This is a method in which the working time of painting is greatly shortened compared with the conventional method. Further, when the putty material is a photo-curable coating, the putty material can be dried by irradiation with light for a short time, so that the working time can be further shortened. Furthermore, the cost of repair painting can be reduced because repair painting can be performed efficiently without the need for specially prepared undercoating paint (primer / surfacer) required for normal repair painting. It is a method that also has an effect. Therefore, the method for repairing an automobile coating film of the present invention can be suitably used in the field of automobile repair coating.

[0088]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In the examples, "parts" means "parts by mass" unless otherwise specified.

Production Example 1 Production of Photocurable Paint 100 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (trade name "Aronix M360", manufactured by Toagosei Co., Ltd.), bis (cyclopentadienyl)
-Bis (2,6-difluoro-3- (1-pyr-1-yl) phenyl) titanium (trade name "IRGACURE 78
4 ", manufactured by Ciba Specialty Chemicals) and 2-mass acryloyloxyethyl acid phosphate (trade name" light ester PA ", manufactured by Kyoeisha Chemical Co., Ltd.)
1 part by mass was mixed to prepare a photocurable coating material.

Example 1 A damaged part of an automobile door part (silver) was appropriately sanded, and the obtained coated plate was repair-painted by the following repair-painting process. [Repair coating step] (1) Application of putty material A commercially available putty was applied to the obtained coated plate with a spatula and left at room temperature after application for 30 minutes to cure the putty. (2) Application of repair base paint On the surface of the putty obtained, nax Admira 002 Crystal Silver (one-component acrylic resin paint made by Nippon Paint Co., Ltd.)
A repair base paint prepared by mixing 100 parts by mass with 100 parts by mass of nax Admira 500 standard thinner (the above-mentioned nax Admira dedicated thinner) is dried by air spray so that the putty part of the test plate after polishing is hidden. A film thickness of about 15 μm was applied and dried with warm air at 60 ° C. for 2 minutes. (3) Polishing Repair The surface of the coating film formed by applying the base paint was sanded with sandpaper # 800. (4) Application of repair base paint On the surface of the coating film after polishing, the above-prepared repair base paint is air sprayed onto a test plate after polishing to give a dry film thickness of 5 to 5.
It was applied to have a thickness of 15 μm. (5) Application of clear paint 100 parts by mass of nax Multi 2100HG clear (two-component isocyanate curing acrylic resin clear paint manufactured by Nippon Paint Co., Ltd.), nax Multi 200 hardener (isocyanate prepolymer solution manufactured by Nippon Paint Co., Ltd.) 50
Parts by mass and nax Multi 500 standard urethane thinner (thinner for synthetic resin coating; aromatic hydrocarbon: ester solvent: ketone solvent = 65:20:15) 60
Mix parts by weight and dilute the paint to a dry film thickness of 30-5.
It was applied by air spray so as to have a thickness of 0 μm. Immediately (within 5 to 6 seconds) after coating this test plate, put it in a hot air circulation type dryer (manufactured by Tabai Co.) adjusted to 80 ° C. for 1
It was dried for 0 minutes.

Example 2 Repair coating was carried out in the same manner as in Example 1 except that (1) the putty material was applied in the repair coating step as follows. (Application of Putty Material) The photocurable coating material obtained in Production Example 1 was applied to the obtained coated plate with a spatula, and light was irradiated from a distance of 5 cm with a 200 W halogen lamp for 2 minutes. After irradiation, "n
The surface adhesive part was wiped off with a cloth soaked with "ax Admira 500 thinner".

Comparative Example 1 A repair coating process was performed as follows. [Repair coating process] (1) Application of putty material The same procedure as in Example 1 was carried out. (2) Undercoat paint for repair (flyer / surfacer)
On the surface of the putty obtained, 100 parts by mass of nax urethane prassaf high seal (isocyanate-curing acrylic resin paint manufactured by Nippon Paint Co., Ltd.), 25 parts by mass of nax urethane prassaf high seal hardener (isocyanate prepolymer solution manufactured by Nippon Paint Co., Ltd.), A base paint for repair prepared by mixing 30 parts by mass of Nax Multi 500 standard urethane thinner (manufactured by Nippon Paint Co., Ltd.) was applied by air spray to a test plate after polishing so as to have a dry film thickness of 25 μm, and 60 ° C. And dried for 30 minutes. (3) Polishing Repair The surface of the coating film formed by applying the base paint was sanded with sandpaper # 800. (4) The coating film surface after degreasing and polishing was degreased by using 50 parts by mass of Nax Silicon Off (manufactured by Nippon Paint Co., Ltd.). (5) Application of repair base paint The same procedure as in Example 1 was carried out. (6) Application of clear paint The same procedure as in Example 1 was carried out.

The working time of the repair coating in Examples 1 and 2 was 81 minutes and 53 minutes, respectively, and the working time of Comparative Example 1 was 109 minutes. As a result, the repair coating of Example 1 and Example 2 requires a short working time,
It was a method that could be efficiently repaired. Also,
Since it is a method that does not use an undercoating paint for repair (primer surfacer), it has been clarified that it is an advantageous method in terms of cost.

[0094]

The method for repairing an automobile coating film according to the present invention has the above-mentioned constitution, and therefore, an undercoat paint for repair (primer
By omitting the coating process of the (surfacer), the cost can be reduced, and the repair coating process and working time can be shortened. Therefore, the method for repairing an automobile coating film can be suitably used for repairing an automobile.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D075 AE03 BB42Z BB95Z DA06                       DA23 DB01 DB02 DB05 DB06                       DB07 DB31 DB36 DB38 DB48                       DB50 DB53 DB55 DC12 DC13                       EA07 EA14 EA21 EA43 EB01                       EB22 EB35 EB38 EB56                 4J038 FA041 FA091 FA111 FA131                       FA151 HA096 HA326 HA366                       HA376 HA416 HA476 JA35                       JC38 KA04 PA17 PB03 PB07                       PB12 PC02 PC08

Claims (5)

[Claims] 1. A step (1) of applying a putty material, a step (2) of applying a repair base paint, a step (3) of polishing the coating film formed by the step (2), and the repair base. A method of repairing an automobile coating film, which comprises the step (4) of applying a coating material, wherein the base paint for repairing is a quick-drying paint. 2. The method for repairing an automobile coating film according to claim 1, further comprising the step (5) of applying a clear coating material for repair. 3. The method for repairing an automobile coating film according to claim 1, wherein the putty material is a photocurable coating material. 4. The photocurable coating composition comprising (a) a titanocene derivative, (b) a compound having a proton donating group, and (c) a compound having at least one ethylenically unsaturated double bond. The mass ratio of the compound (b) having a proton donating group to the compound (c) having at least one ethylenically unsaturated double bond is 0.01: 99.99 to 20:80. And the amount of the (a) titanocene derivative relative to 100 parts by mass in total of the (b) compound having a proton donating group and the (c) compound having at least one ethylenically unsaturated double bond is 0. The method for repairing an automobile coating film according to claim 3, wherein the amount is 0.01 to 10 parts by mass. 5. A base material having a coating film obtained by the method for repairing an automobile coating film according to claim 1, 2, 3 or 4.