JP2002282784A - Film forming method and base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a film having excellent forming property and workability even on the surface of a base material surface having a complicated shaped surface in the film forming method using a photosetting type coating material. SOLUTION: The film forming method includes a process performed by applying the photosetting type coating material on the base material, hardening the resultant coating film with the irradiation with light without coating the resultant film and further irradiating with light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a coating film suitably used for repair painting of automobiles and the like, and a substrate having a coating film obtained by the above-described coating film forming method.

[0002]

2. Description of the Related Art When a coating film formed on the surface of an automobile body or parts has a defect due to an accident or the like, a repair coating is applied to the defective portion. In general, the repair coating is performed by polishing the part to be repaired with an abrasive or the like, applying a putty with a spatula or the like, polishing the putty surface to make it smooth, and then performing a surface treatment. , A primer surfacer and a top coat are sequentially applied.

[0003] As the putty, a photocurable paint may be used. In the case of photocurable coatings, curing inhibition occurs in the presence of oxygen. Therefore, when curing the applied coating film by irradiating light, the coating film surface is made of PET in order to prevent curing inhibition due to oxygen on the coating film surface. It is common practice to cover with a film. As a result, oxygen is blocked and a good cured coating film is obtained.

However, when a photocurable paint is applied to a substrate surface having a complicated shape such as a curved surface portion of a vehicle body bumper, it is difficult for the PET film to follow the curved surface portion.
There is a problem in that air is mixed between the film and the coated surface to cause burrows in the coated surface, or to cause irregularities such as unevenness on the surface, thereby deteriorating the smoothness of the surface.

[0005] Japanese Patent Application Laid-Open No. 10-34081 discloses that a photocurable coating material is applied to a substrate surface for the purpose of forming a good coating film even on a substrate surface having a complicated shape, A coating method is disclosed in which a liquid film is formed on a coating film surface using a temporary protective agent, the coating film surface is cured by light irradiation, and then the temporary protective agent is removed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a coating film using a photocurable paint, which has excellent moldability and workability even on a substrate surface having a complicated shape. It is to provide a forming method.

[0007]

According to the present invention, a photocurable paint is applied to a substrate, cured by light irradiation without coating the surface of the obtained coating film, and then coated on the surface of the coating film. A coating film forming method comprising a step of irradiating. The photocurable paint is to be applied to a repaired site on a substrate, and is preferably a putty material.

The photocurable coating material 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 (b) the compound having a proton donating group and (c) at least one ethylenically unsaturated double bond The weight ratio to the compound having the compound is 0.1.
01: 99.99 to 20:80, and the total of (b) the compound having a proton donating group and (c) the compound having at least one ethylenically unsaturated double bond is 1 in total.
The amount of the titanocene derivative (a) is preferably 0.01 to 10 parts by weight based on 00 parts by weight. In the above-mentioned coating film forming method, after that, a top coat can be further applied, and before the above-mentioned top coat is applied, a primer surfacer can be applied. The present invention is also a substrate having a coating film obtained by the above coating film forming method. Hereinafter, the present invention will be described in detail.

In the method for forming a coating film of the present invention, a photocurable coating material is applied to a substrate. The substrate is not particularly limited, and can be advantageously used for products such as metals, plastics, and foams.

The metal product is not particularly limited, and examples thereof include simple metals such as iron, copper, aluminum, tin, and zinc, and alloys containing such simple metals. Specifically, the vehicle body and parts of automobiles such as passenger cars, trucks, motorcycles, and buses are exemplified. It is particularly preferable that the metal product has been subjected to a chemical conversion treatment with a phosphate, a chromate or the like in advance. On the steel sheet thus chemically treated, an electrodeposition coating film can be further formed using a cationic or anion type electrodeposition coating material, but since a laminated coating film having excellent corrosion resistance is provided, A cationic electrodeposition coating composition is preferred.

Examples of the plastic substrate include products such as polypropylene resin, polycarbonate resin, urethane resin, polyester resin, polystyrene resin, ABS resin, vinyl chloride resin, and polyamide resin. For example, spoilers, bumpers, mirror covers, and the like. , Grills, door knobs and other automotive parts. The plastic product is preferably subjected to steam cleaning with trichloroethane or a neutral detergent, and may be further subjected to primer coating for enabling electrostatic coating.

The above-mentioned base material is optionally provided with the above-mentioned chemical conversion film,
In addition to the electrodeposition coating and the primer coating, an intermediate coating and a top coating are usually formed in this order. When the coating film formed on the base material surface has a defect due to an accident or the like, the repaired portion is usually gently sloped by so-called water-sharpening or empty-sharpening using an abrasive such as sandpaper. Polished and cleaned with a degreasing agent. The polishing may be performed to such an extent that an undercoating film such as an intermediate coating film or an electrodeposition coating film of the repaired portion is exposed.

In the present invention, the photocurable paint is applied to the repaired portion on the base material. In this case, the photocurable paint is used as a putty material. The photo-curable paint is not particularly limited as long as it is a UV, visible light and infrared light curable paint, but from the viewpoint of thick film formation and work environment, visible light and / or near-infrared light curable paint is preferable. Preferably, more preferably, it is a visible light curing type. As the photocurable paint, those containing an unsaturated resin, an unsaturated monomer, a filler, a photopolymerization initiator and the like can be used.

Examples of the unsaturated resin include 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. Examples of the unsaturated monomer include styrene,
Examples thereof include vinyl toluene, methyl methacrylate, and diallyl phthalate.

The filler can be arbitrarily selected from known inorganic and organic fillers. Specific examples of the inorganic filler 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, etc. Specific examples include polyethylene powder, plastic balloons, and rubber particles. In the case of visible light curing type,
In order to enable a thicker film to be cured, it is preferable to select one of the above fillers that does not hinder the transmission of visible light.

The photopolymerization initiator may be any one that can be excited by light energy in the UV, visible or infrared region depending on the photocurable coating material to be used. Examples thereof include camphorquinone, benzyl, and 3-ketocoumarin. 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.

The above-mentioned photocurable paint is also disclosed in JP-A-8-60.
04, JP-A-9-137089, JP-A-9-157318, JP-A-9-176517, JP-A-9-241533, JP-A-9-249
JP-A-831, JP-A-9-255707, JP-A-9-302262 and the like can also be used.

In the present invention, (a) a titanocene derivative, (b) a compound having a proton donating group, and (c) a compound having at least one ethylenically unsaturated double bond are used as the photocurable paint. And the weight ratio between (b) and (c) is 0.01: 99.99 to 20:80.
Wherein the amount of the (a) titanocene derivative is 0.01 to 10 parts by weight based on 100 parts by weight of the total of (b) and (c)
Photopolymerizable compositions that are parts by weight are particularly preferred. The photopolymerizable composition, curability, adhesion, coating performance such as water resistance,
And it is excellent in storage stability.

As the (a) titanocene derivative, conventionally known ones can be used. For example, JP
JP-A-9-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-24
9, titanocene derivatives described in JP-A-2-4705. Specific examples include 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 and the like can be mentioned.

The compound (b) having a proton donating group includes hydrochloric acid, sulfuric acid, sulfonic acid, sulfinic acid,
Inorganic acids such as phosphoric acid; acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, bisphenol A type epoxy acrylate Examples thereof include acid anhydride modified compounds, bisphenol A type epoxy (meth) acrylate phosphoric acid modified compounds, and organic acids such as phosphoric acid (meth) acrylates. From the viewpoint of the water resistance of the cured product, those having at least one ethylenically unsaturated double bond in the molecule are preferable, and when the substrate on which the photopolymerizable composition is applied is a metal, it is adhered. From the viewpoint of properties, phosphoric acid (meth) acrylates are preferred.

The compound (c) having at least one ethylenically unsaturated double bond is not particularly limited.
For example, methyl (meth) acrylate, ethyl (meth)
Acrylate, methoxypolyethylene glycol (meth) acrylate, phenyl (meth) acrylate, 2
-(Meth) acrylate compounds such as hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate and (meth) acrylamide; styrene, α-
Styrenes such as methylstyrene; (meth) acrylates of polyhydric alcohol ethylene oxide or propylene oxide adducts; monofunctional glycidyl compounds and (meth)
Reaction products with acrylic acid and the like can be mentioned.

Compounds having two or more ethylenically unsaturated double bonds can also be used. Specifically, an ester of a polyhydroxy compound such as ethylene glycol di (meth) acrylate with (meth) acrylic acid can be used. A (meth) acrylate of an ethylene oxide or propylene oxide adduct of a polyhydric alcohol; a reaction product of a polyepoxy compound such as epichlorohydrin bisphenol type epoxy resin and (meth) acrylic acid; a polyisocyanate compound such as hexamethylene diisocyanate and a hydroxyl group-containing ( Urethane (meth) acrylate obtained from meth) acrylate; urethane (meth) acrylate obtained from the above isocyanate compound, polyester having a hydroxyl group at a terminal and hydroxyl group-containing (meth) acrylate;
Unsaturated polyester resins obtained from ethylenically unsaturated carboxylic acids or anhydrides thereof and polyhydric alcohols; polyester (meth) acrylates obtained from polybasic acids, polyhydric alcohols and (meth) acrylic acid;
These may be used alone or in combination of two or more.

The application of the photocurable paint can be carried out by a conventionally known method such as a spatula or a roller, and the thickness thereof is preferably about 0.1 to 10 mm. It is preferable that the shape of the applied surface is adjusted by a roller or the like, whereby a good finished surface is obtained.

In the present invention, the coating film obtained as described above is subjected to the first light irradiation without coating the surface. By irradiating light without coating the coating surface, curing inhibition due to oxygen in the air occurs, and the coating surface is uncured, but the interior of the coating not in contact with air is cured. Can be.

The light irradiation can be selected from ultraviolet light, visible light, electron beam, X-ray, short-wavelength light, and the like, depending on the type of the photocurable paint used. As the light source, a point light source and a surface light source can also be used. Examples of the light source include a mercury lamp, a laser, a rare gas discharge lamp, a metal halide lamp, a halogen lamp, a fluorescent lamp, a carbon electrode arc lamp, an argon incandescent lamp, an electronic flash lamp, a photographic floodlight lamp, and a light emitting diode. . Also,
Sunlight can also be used as a light source. The irradiation time can be selected depending on the purpose of use, the type and intensity of the lamp, but is about several tens seconds to several minutes.

In the present invention, the surface of the coating film is coated after being cured by the above-mentioned light irradiation, or, if necessary, after further removing the uncured portion with a solvent, and then the second light irradiation is performed. By performing further light irradiation after coating the surface of the coating film, the surface of the coating film that has been uncured by the first light irradiation can be cured. Even when the portion is removed with a solvent, the remaining uncured portion can be cured. Furthermore, by the first light irradiation,
Since the inside of the coating that is not in contact with the air has already been cured, coating the surface of the coating and further irradiating the light will cause deformation such as burrows on the coating surface and unevenness on the surface. It does not occur and is excellent in moldability and workability even on a substrate surface having a complicated shape.

The method for coating the coating film surface is not particularly limited as long as it can effectively block the coating film surface from the air. For example, a method for covering with a PET (polyethylene terephthalate) film; A method of forming a liquid film with a protective agent can be used. In the present invention, a method of covering with a PET film is preferable for simplicity.

The temporary protective agent is preferably capable of forming a substantially non-adhesive film layer at room temperature.
Glass transition temperature of 20 to 80 ° C, preferably 40 to 70
Those using a film-forming resin at a temperature of ° C are more preferable.
Further, those which are soluble in water, a solvent or the like are preferable because they are removed after use. Examples of such a film-forming resin include polyvinyl alcohol, partially saponified vinyl acetate or a mixture thereof, or polyvinyl alcohol.
And a mixture of vinyl acetate and vinyl acetate polymer.

The temporary protective agent may contain additives such as an antifoaming agent, a coating surface conditioner, and an organic solvent, if necessary. A silicone-based surfactant such as ter-modified dimethylpolysiloxane or a copolymer thereof is added to the protective agent solution in an amount of 0.05 to
It is preferable to add about 5% by weight. As a method of forming a liquid film with the temporary protective agent, flow coating and spray coating are suitable.
μm, preferably about 2 to 5 μm.

After the coating film surface is coated as described above, a second light irradiation is performed. In this case, the light irradiation method may be the above-described method. The cured coating formed by light irradiation as described above, after removing the coating on the coating surface, or after removing with water or a solvent, if desired, further,
Surface treatment for polishing and smoothing the cured coating film on the surface can be performed.

Thereafter, a generally gray coating film called a so-called primer surfacer may be formed thereon, and this coating film is usually subjected to surface treatment. The above-mentioned primer surfacer adjusts the skin of the repaired part,
It is used for hiding the undercolor. As the above-mentioned primer / surfacer, conventionally known ones can be used, and a film-forming resin such as an acrylic resin, a polyester resin and an alkyd resin, a crosslinking agent such as a polyisocyanate compound if necessary, and an organic / inorganic coloring Pigments containing a pigment and / or extender may be used. The coating form of the primer / surfacer is not particularly limited, and may be any of an organic solvent type, an aqueous (water-soluble, water-dispersible, emulsion) type and a non-aqueous type. The coating film obtained by the above-mentioned primer / surfacer may be dried at room temperature or may be force-dried. The forced drying is usually performed by heating at 40 to 60 ° C. for about 5 to 30 minutes.

On the coating film obtained by the above-mentioned primer / surfacer, an overcoat is further applied.
As the above-mentioned top coat, the composition of the paint, the kind and amount of the pigment, and the like are selected so as to match with the top coat that is originally formed on the base material and is applied around the repaired portion without any discomfort. The overcoating can be performed using a solid color paint, a metallic base paint, and / or a clear paint. Known solid color paints, metallic base paints, and clear paints can be used.

As described above, the coating film forming method of the present invention comprises:
Even on a substrate surface having a complicated shape, a cured coating film having excellent finishability can be formed with excellent moldability and workability. The substrate on which such a cured coating film is formed is also one of the present invention.

[0034]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example (1) Preparation of photopolymerizable putty composition 30 parts by weight of bisphenol A type epoxy acrylate oligomer (VR-90, manufactured by Showa Polymer Co., Ltd.), methoxydipropylene glycol acrylate (light acrylate DMP-A, manufactured by Kyoeisha Chemical Co., Ltd.) ) 20 parts by weight, 50 parts by weight of talc (NK-64, manufactured by Fuji Talc), bis (cyclopentadienyl) -bis (2,6-difluoro-3)
1 part by weight of-(1-pyru-1-yl) phenyl) titanium (Irgacure 784, manufactured by Ciba Specialty Chemicals) and 1 part by weight of 2-acryloyloxyethyl acid phosphate (light ester PA, manufactured by Kyoeisha Chemical Co., Ltd.) A mixed visible light putty composition was made. (2) Preparation of Coated Plate The above putty was applied to a tin plate with a thickness of 2 mm, and
Light irradiation was performed with a W halogen lamp at a distance of 5 cm for 2 minutes. Thereafter, a PET film was adhered and light irradiation was performed similarly. According to the following, when the surface tackiness was evaluated,
No tackiness was observed on the surface, and the surface was good. Surface tackiness test The surface of the coated plate was pressed with a finger to evaluate the presence or absence of a tacky portion due to curing inhibition.

COMPARATIVE EXAMPLE After irradiating light once in the same manner as in the example, at the time of the second irradiation, a test coated plate irradiated with light without attaching a PET film was obtained. When the surface tackiness was evaluated in the same manner as in the examples, there was considerable surface tackiness.

From the above results, in the example in which the applied visible light putty composition was irradiated with light, a PET film was attached, and the light irradiation was further performed, no tackiness was observed on the surface. On the other hand, light irradiation was performed without attaching a PET film.
In the comparative example performed repeatedly, the surface was in an adhesive state.

[0037]

According to the coating film forming method of the present invention, it is possible to form a cured coating film having excellent moldability and workability and excellent finish even on a substrate surface having a complicated shape.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/04 CEZ C08J 7/04 CEZZ C09D 7/12 C09D 7/12 201/00 201/00 // C08L 101: 00 C08L 101: 00 F term (reference) 4D075 BB42Z CA06 DA27 DB02 DB07 DB31 DC12 DC13 EA21 4F006 AB34 AB42 AB68 AB76 BA00 CA04 EA03 4F100 AC10 AC10H AH10B AK02B AK08B AK25 AK25J AK53 AK53BA10BA00 BA00A00 BA00A00 BA00A00A00 CC00D EG002 EH462 EJ082 EJ522 EJ651 EJ851 EJ91C EJ99 GB32 JB14B JL01 4J038 EA011 HA096 HA366 HA416 JA37 JA39 JA50 JA56 JA57 JC38 KA08 PA17 PB07 PC02

Claims (7)

[Claims] Claims 1. A photocurable coating material is applied to a substrate and cured by light irradiation without coating the surface of the obtained coating film.
A method for forming a coating film, comprising a step of coating the surface of the coating film and further irradiating light. 2. The method for forming a coating film according to claim 1, wherein the photocurable coating material is applied to a portion to be repaired on a substrate. 3. The photo-curable coating material is a putty material.
Or the coating film forming method according to 2. 4. A photocurable coating material comprising: (a) a titanocene derivative; (b) a compound having a proton donating group;
(C) a compound having at least one ethylenically unsaturated double bond, wherein (b) the compound having a proton donating group and (c) at least one ethylenically unsaturated double bond The weight ratio to the compound having the compound is 0.1.
01: 99.99 to 20:80, and the total of (b) the compound having a proton donating group and (c) the compound having at least one ethylenically unsaturated double bond is 1 in total.
The amount of the (a) titanocene derivative per 100 parts by weight is 0.01 to 10 parts by weight.
4. The method for forming a coating film according to 2 or 3. 5. The method for forming a coating film according to claim 1, wherein a top coat is applied thereafter. 6. The method according to claim 1, wherein a primer surfacer is applied before the top coat is applied.
6. The method for forming a coating film according to 4 or 5. 7. A substrate having a coating film obtained by the method for forming a coating film according to claim 1, 2, 3, 4, 5, or 6.