JPH0433504B2 - - Google Patents

Description

[Detailed Description of the Invention] [Prior Art] Cracking paints conventionally used for building materials, etc. are made by coating a material 11 with a heat-drying undercoat paint, curing this coating film 12, and then applying a cracking paint. By painting and heating, cracks were formed in the coating film 13 made of the cracking paint. However, in this method, a cracking paint that has an affinity for the cured undercoat film is applied to form a paint film, and cracks are forcibly formed in this paint film. The membrane is required to be relatively soft, and as a result, many wrinkles 15 remain within the groove 14 of the crack.
When viewed up close, the appearance is not very good, and this type of coating could not be applied to everyday items such as cosmetic containers. Furthermore, as a result of the crack formation, a coating film 12 of the undercoat appears on the surface of the groove 14, but as mentioned above, conventional undercoat paints have a soft coating and are relatively easily scratched. Usually, a thick clear coat is applied after the crack is formed to improve scratch resistance and appearance.

[Object of the present invention]

The object of the present invention is to eliminate the drawbacks of the prior art as described above, and to form a painted surface that is completely free of wrinkles and has an extremely high design quality, as shown in FIG.

[Summary of the invention]

In the present invention, as an undercoat for a cracking paint, a photo-curable paint that causes almost no thermal reaction, such as an ultraviolet-curable paint containing methyl methacrylate as a main component, is applied to a coated object 1 to form a coating film 2,
While this is still in its uncured state, a cracking paint is applied, which, in contrast to an undercoat, dries quickly under heat and has a very high shrinkage rate, causing the paint itself to crack when heated. For example, by heating the coating film 3 made of a cracking paint for about 5 to 10 minutes at about 40 to 60°C to form cracks 4, it becomes extremely decorative, as if the film were cracked on water. After forming a highly cracked pattern and applying a photo-curing paint on top of this as necessary, the photo-curing paint film is finally irradiated with light energy to cure the photo-curing paint.

Although it is a two-step process, it is also possible to perform the irradiation with light energy after the cracking coating film has been formed, then apply the photocurable paint again, and then irradiate the light energy again to cure the top coat paint.

Generally, the thickness of the undercoat film is about 5 to 40μ, especially 10
~20μ is preferable, and the thickness of the cracking coating is approximately 5 to 30μ, with thinner coatings producing fine cracks and thicker coatings producing larger cracks.

[Undercoat paint of the present invention]

The undercoat paint of the present invention is a light-curable paint that does not substantially undergo curing due to heat and can maintain a state in which the paint film can move freely no matter how much it is heated. Lines etc. are used.

The main components of the undercoating paint of the present invention usually consist of oligomers, monomers, and sensitizers. Examples of preferred combinations of these oligomers and monomers include acrylic resin oligomers and acrylic monomers, acrylic resin oligomers and acrylic monomers, and acrylic oils and acrylic monomers. Monomer, acrylated alkyd resin and acrylic monomer, polyester acrylate and acrylic monomer,
There are polyether acrylate and acrylic monomer, acrylated epoxy resin and acrylic monomer, acrylated polyurethane and acrylic monomer, acrylated spiran resin and acrylic monomer, etc. Acrylic monomers include acrylic acid, methacrylic acid, and ethacrylic acid. Acids or esters thereof are typical. Further, as the sensitizer, suitable ones can be selected singly or in combination from conventionally known photosensitizers depending on the heating conditions of the post-process, the nature of the light energy used, etc. However, typical examples include carbonyl compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetophenone, 2,2-diethoxyacetophenone, benzophenone, p,
p'-bismethylaminophenone, thioxanthone, 2-chlorothioxanthone, diacetyl, benzyl, α-haloketone, 2-chloroanthraquinone, etc.; organic peroxides such as benzoyl peroxide, di-t-butyl peroxide, etc.; azo compounds For example, azobisisobutyronitrile, 2,2'-azobispropane, m,m'-azoxystyrene, etc.; halides, such as carbon tetrabromide, α-bromonaphthalene, 1-chloromethylnaphthalene, etc.; sulfur compounds, Examples include diphenyl disulfide, dibenzyl disulfide, dibenzothiazoyl disulfide, and tetramethylthiuram disulfide.

In addition, reactive diluents that are conventionally used in these photocurable coatings as diluents and crosslinking agents for oligomers or resins can also be used. Representative examples include 2-ethylhexyl acrylate, cyclohexyl acrylate, butoxyethyl acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol. Examples include triacrylate, dianol 2,2-diacrylate, polyester diacrylate, unsaturated polyester resin, and vinyl ester resin.

It goes without saying that the photocurable coating material of the present invention may contain various conventional additives, such as stabilizers, ultraviolet absorbers, solvents, leveling agents, etc., as needed.

[Cracking paint of the present invention]

The cracking paint of the present invention has the property that it can be coated with the above-mentioned photocurable undercoat paint while it is still in a wet state, and the paint film quickly shrinks and hardens when heated at a relatively low temperature. It is a paint that has the property of forming cracks.

Typical examples include nitrocellulose as the main component and crack-forming aid as the resin component.
Examples include paints containing stearate and the like.
Specific examples of stearates include calcium stearate, lead stearate, zinc stearate, and the like.

[Coated object of the present invention]

The object to be coated according to the present invention is completely arbitrary and is not limited in any way, and examples include plastics, metals, ceramics, wood, etc., but in particular, the cracking coating according to the present invention has an extremely beautiful finish. Therefore, cosmetic tools, cosmetic containers, etc. are suitable objects to be coated.

[Painting line of the present invention]

An example of the painting line of the present invention is shown in FIG.

In the product mounting device 21, the object to be coated is attached to a conveyor belt moving at a speed of 7 to 10 m/min, and delivered to the coating booth 22. Front part of painting booth 2
3, spray painting with a light-curing paint and spray painting with a cracking paint on the latter part 24, then move to the setting zone 25, where the temperature is heated to about 40 to 60°C using a far-infrared lamp installed here. Heat for 5 to 10 minutes. Here, a crack pattern is formed. next
Irradiation zone 2 with four 80w/cm high-pressure mercury lamps
6, the photocurable paint completes curing, and is cooled to room temperature in a cooling zone 27.

[Effects of the present invention]

In the present invention, by selecting a photocurable paint as the undercoat paint as described above, cracking of the topcoat film is not caused at all.
It's like a membrane cracking on top of water.
Forms a wonderful pattern with no wrinkles. Moreover, it is not necessary to have a soft coating film as the undercoat paint, and for example, a paint containing methyl methacrylate or methyl ethacrylate as a main component can be used, so the cured film is very hard. Therefore, even if the undercoat film comes to the surface due to crack formation, this paint film is strong, so
Furthermore, there is an advantage that top-coating is not an essential requirement.

Since a photocurable paint that forms a hard film is used as the undercoat, the overall strength of the film is increased, and production efficiency is also improved.

Example A cosmetic tool (compact) made of ABS resin with aluminum vacuum-deposited on it was coated with an ultraviolet cross-linking curable paint known as Diabeam (product name: Diabeam) manufactured by Mitsubishi Rayon Co., Ltd. benzophenone, ultraviolet absorber,
(consists of thinner, leveling agent, etc.)
was spray-painted, and then immediately spray-painted cracking paint while still wet.

Cratsking paint is manufactured by Musashi Paint Co., Ltd. and is known under the trade name Nitron.
Thin viscosity with 80 to 100 parts of thinner to 100 parts
The temperature adjusted to 14 to 20 seconds (IHS.NK-2/20°C) was used.

Approximately 60% after spray painting with Kratzking paint
℃ for about 5 minutes to evaporate the solvent in the ultraviolet cross-linking curable paint and form cracks, and finally,
The ultraviolet cross-linking curable paint was completely cured by irradiation with a high-pressure mercury lamp or the like. This resulted in a clean compact with no wrinkles and a cracked pattern.

[Brief explanation of drawings]

Figure 1 is a sectional view of the coated product of the present invention, Figures 2 and 3 are
The figure is a sectional view of a coated product according to the conventional method, and FIG. 4 is a flow sheet showing an example of the coating line of the present invention. 1...Object to be coated, 2...Coating film of light-curing paint as undercoat, 3...Coating film of cracking paint as topcoat, 4...
Cracking groove, 11... Conventional coated object, 12... Conventional undercoat paint film, 13... Top coat cracking paint film, 14... Cracking groove, 15... Wrinkles generated in the crack groove part, 16... Clear overcoat layer, 21... Product attachment device, 22...
Painting booth, 23... Parts sprayed with undercoat paint, 24... Parts sprayed with top coat paint, 25
...Setting zone, 26...Irradiation zone, 27
...cooling zone.

Claims (1)

[Scope of Claims] 1. A light-curing paint that does not harden by heating is applied as an undercoat to the object to be coated, and while this is still uncured, a heat-fast-drying cracking paint is applied, and this is heated to A cracking coating method characterized by forming cracks in a coating film made of cracking paint, and then irradiating light energy to harden the coating film made of photocurable paint. 2 The object to be coated is coated with a light-curing paint that does not harden by heating, and while this is still uncured, a heat-fast-drying cracking paint is applied, and this is heated to form a coating film made of the cracking paint. A cracking coating method characterized by forming cracks, then coating the cracks with a photocurable paint, and then irradiating light energy to harden the coating film of the photocurable paint. 3 The object to be coated is coated with an undercoat of a light-curing paint that does not harden by heating, and while this is still uncured, a heat-fast-drying cracking paint is applied, and this is heated to form a coating film made of the cracking paint. A crack is formed, the undercoat film is cured by irradiating it with light energy, then a photocurable paint is further applied on top of the crack, and the film of the photocurable paint is cured by irradiating this with light energy. A cracking painting method characterized by: