JPS594505B2 - Manufacturing method for lighting reflector with excellent heat resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a reflective mirror for lighting, and more specifically, to a reflective mirror for lighting that is a thin film with a metallic luster and excellent heat resistance, in which a metal plating layer is formed on a metal surface by a vacuum evaporation method. This relates to a manufacturing method.

Traditionally, aluminum, copper, chromium,
It is well known that metal plating is carried out by vacuum evaporation using metals such as nickel or alloys thereof. The thickness of the metal plated body produced by this vacuum evaporation method is much thinner than 1 micron, so if the metal plated layer is formed directly on the bare surface of the metal adherend, the appearance will be markedly affected due to scratches on the bare surface, lack of smoothness, etc. Moreover, the adhesion between the bare surface of the adherend and the metal plating layer was extremely poor, resulting in problems such as detachment of the metal plating layer. In order to compensate for these defects, a base coat layer with a thickness of 30 to 50 mm is applied between the bare surface of the adherend and the metal plating layer.
It is generally practiced to interpose a resin film of about micron size and form a metal plating layer on the surface of the resin film. The base coat layer is coated with a resin solution prepared by dissolving melamine-alkyd resin, melamine-acrylic resin, acrylic resin, etc. in an organic solvent, and then heat-treated at 150 to 180°C for about 30 minutes. A method is used to solidify it. However, the method
Because it requires heat treatment at high temperatures for a long time, it requires a huge amount of thermal energy, which poses problems in terms of production efficiency.Furthermore, it is difficult to obtain a thick film because it contains a large amount of organic solvent. This resulted in poor finished appearance of the metal plated body, and was also problematic in terms of resource conservation. In recent years, from the viewpoint of solving the above-mentioned problems, a method has been developed in which a resin liquid having unsaturated groups is coated on the base coat layer and the treatment is carried out in a short time and efficiently using active energy of ionizing radiation or electromagnetic O waves. Although many attempts have been made, there are various problems and most of them have not reached the practical stage. In other words, one of the problems is to take an automobile headlamp reflector as an example.The reflecting surface is made of an aluminum layer made by vacuum evaporation, but one end of the electric circuit cord is removed during the installation process to the automobile body. It is necessary to solder the back of the reflective mirror, but the heat causes a multicolored rainbow pattern, wrinkles, cracks, etc. on the surface of the aluminum plating layer that hits the reflective surface, causing the original shine of the aluminum plating to disappear and causing diffuse reflection. Therefore, the biggest drawback was that it no longer functioned as a reflector for the headlamp. The present invention aims to solve these problems, bring the use of ultraviolet energy to a practical stage, and provide a method for efficiently manufacturing a lighting reflector with excellent heat resistance in a short time. That is, the present invention provides: (i) 50% to 90% by weight of an epoxy-modified acrylic resin and/or a polyester-modified ataryl resin and 50% to 10% by weight of a polymerizable monomer containing a (meth)acryloyl group on the metal surface. %, and (1) 0.05 to 1 part by weight per 100 parts by weight of the resin liquid.
After applying a composition consisting of 5 parts by weight of a photosensitizer, a coating formed by irradiating ultraviolet rays and solidifying the film is used as a base coat layer,
The present invention relates to a method for manufacturing a lighting reflector with excellent heat resistance, which comprises forming an aluminum plating layer on the surface of the base coat layer by vacuum evaporation at a degree of vacuum of 1×10 −5 T0rr or more.

The resin liquid used in the present invention is mainly composed of an epoxy-modified acrylic resin and/or a polyester-modified acrylic resin, a polymerizable monomer containing a (meth)acryloyl group, and a photosensitizer, if necessary. It is a composition consisting of an organic solvent and the like.

As the epoxy modified acrylic resin, UcOat2
Ol [trade name manufactured by Toho Chemical Industry Co., Ltd.]; Deitskulite UE81OO, Deitzclite UE82OO [trade name manufactured by Dainippon Ink and Chemicals (Mai)], etc.; polyester-modified acrylic resins include the patent application published in 1972. In addition to the compounds described in Publication No. 27523, Aronix M8O3O, Aronix M8O6O (trade name, manufactured by Toagosei Chemical Industry Co., Ltd.) and the like may be mentioned.

Further, examples of the electrochemical monomer containing the (meth)acryloyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. as the hydroxyl group-containing monomer. Examples of ether compounds of 1 and alkyl alcohol or cyclic alkyl alcohol include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, tetrahydrofurfuryl acrylate, and esters of (meth)acrylic acid and acrylic alcohol. As a compound, methyl (meth)acrylate, butyl (meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)
Examples include acrylate, trimethylolpropane tri(meth)acrylate, and the like.

The resin liquid of the present invention has an epoxy-modified acrylic resin and/or a polyester-modified acrylic resin as its main component, and is combined with an appropriate polymerizable monomer depending on the difficulty of painting work, the surface condition of the coating film, etc. to adjust the viscosity and properties of the resin liquid. Furthermore, when the coating method requires a low viscosity resin liquid, there is no problem even if an organic solvent is used in combination.

The mixing ratio of the epoxy-modified acrylic resin and/or polyester-modified acrylic resin and the polymerizable monomer containing a (meth)acryloyl group is 50 to 90 bundles of the former?
% and the latter 50 to 10% by weight.

If the polymerizable monomer content is less than 10% by weight, problems will occur in terms of coating workability, and if the polymerizable monomer content exceeds 50% by weight, problems will arise in terms of the surface smoothness of the base coat layer, which is undesirable. .

The aforementioned polymerizable polymers, oligomers, and polymerizable monomers are not limited to the use of a mixture of only one type, but it is also possible to combine two or more types to bring out the characteristics of each. Furthermore, since ultraviolet rays are used as an energy source for solidifying the resin liquid of the present invention, it is necessary to add a photosensitizer.

For example, photosensitizers include benzoin, benzoin methyl ether, benzoin isopropyl ether, benzyl, benzophenone, anthraquinone, naphthoquinone,
Examples include chloranthraquinone, tetramethylthiuram disulfide, diphenyl disulfide, 22-diethoxyacetofconone, benzoin peroxide, azobisisobutyronitrile, 22-azobispropane, etc., and the amount used is The amount is 0.05 to 15 parts by weight, preferably 2 to 5 parts by weight, based on 100 parts by weight of the total content of epoxy-modified acrylic resin and/or polyester-modified acrylic resin and military monomer in the resin liquid. Other additives such as a leveling agent, a polymerization inhibitor, an anti-sagging agent, etc. can be added to the resin liquid of the present invention as necessary.
Talc, calcium carbonate, magnesium carbonate, silica,
It is also possible to mix it with extender pigments such as barium sulfate, coloring pigments, antirust pigments, etc. and use it in the same form as known coating compositions.

The method for manufacturing a metal plating body of the present invention includes a roll coater,
Apply a film to the desired thickness, preferably 30 to 50, on the metal surface by a known method such as spraying, curtain flow coater, or brush coating.
The resin liquid may be applied to a thickness of about microns and then irradiated with ultraviolet rays.

Then, an aluminum plating layer having a thickness of about 200 to 500 Å may be formed on the surface of the solidified base coat layer by vacuum evaporation. As mentioned above, conventional metal plating bodies obtained by using known ionizing radiation or electromagnetic wave active energy irradiation and solidification as a base coat layer have poor heat resistance and have not been put to practical use. However, as a result of investigating the cause of defects such as multicolored rainbow patterns, wrinkles, and cracks, the present inventors found that the cause was a trace amount of polymerizable monomer remaining in the base coat layer film after solidification. I've reached it.

An attempt was made to remove the residual polymerizable monomer by extending the active energy irradiation time, but this had little effect.
The present inventors filed an application for a method of removing residual polymerizable monomers by heat-treating a base coat layer in a pre-process to form a metal plating layer.

After that, as a result of various studies, we found that the same effect can be obtained by maintaining the degree of vacuum during vacuum evaporation at 1 x 10-5T0rr or higher, and then applying heat treatment by applying a metal plating layer using the vacuum evaporation method. We have arrived at the heading Invention.

Conventionally, the vacuum degree of known vacuum evaporation plating is 3 x 10-4
It is generally carried out at a vacuum of about 7×10 −5 T0rr, but this level of vacuum is completely ineffective in removing the residual polymerizable monomer in the base coat layer.

It is estimated that by holding the base coat layer under a high degree of vacuum as in the present invention, there is an effect of suctioning and removing the trace amount of polymerizable monomer remaining in the base coat layer. A metal plating layer applied to the base coat layer is extremely effective in significantly improving the mutual adhesion between the base coat layer and the metal plating layer.

The metal-plated body thus obtained has extremely excellent heat resistance, with no multicolored rainbow patterns, wrinkles, cracks, etc. observed even when heated. Since the metal plating layer of the metal plating body obtained by the method of the present invention is an extremely thin film, for the purpose of protecting the plating layer and preventing surface contamination, a coat of the same type as that used for the base coat described above is applied to the surface of the metal plating layer. or melamine-alkyd resin liquid,
It is also possible to provide a surface protective layer by applying and solidifying thermosetting resin liquids such as acrylic-alkyd resin liquids and acrylic resin liquids, or room temperature curing resin liquids such as polyurethane resin liquids and epoxy resin liquids. . Next, specific effects of the present invention will be explained by giving examples.

"Part" or "%" indicates "part by weight" or "% by weight".
Example 1 A dry film thickness of 50 mm was applied to the surface of a cold-rolled steel sheet after polishing and cleaning the resin liquid.
The coating was spray-painted to a micron thickness, and after setting at room temperature for 10 minutes, it was irradiated with one high-pressure mercury lamp with a lamp input of 80 W/CITL at an irradiation distance of 20 degrees for 60 seconds to obtain a base coat layer.

Next, the surface of the base coat layer is coated with a vacuum degree of 1 using a vacuum evaporation method.
An aluminum plating layer was formed by 500 people under the condition of x10-5T0rr to obtain a metal plating body. Example 2 The resin liquid was spray-coated on the surface of a cold-rolled steel sheet that had been polished and cleaned to a dry film thickness of 50 microns, and then dried in a hot air drying oven for 50 microns.
After setting for 5 minutes at ℃, lamp input 80W/CfL
60 at an irradiation distance of 20CTfL with one high-pressure mercury lamp.
A base coat layer was obtained by irradiating for seconds.

Next, the surface of the base coat layer is coated with a vacuum degree of 3 using a vacuum evaporation method.
A metal plated body was obtained by forming 500 aluminum plating layers under the conditions of X10-6T0rr. Example 3 A dry film thickness of 50 mm was applied to the surface of a cold-rolled steel sheet after polishing and cleaning the resin liquid.
After spray painting to a micron density and setting for 10 minutes at room temperature, the lamp power is 160W/C! Irradiation distance is 20C with one n high pressure mercury lamp! A base coat layer was obtained by irradiating with IL for 30 seconds.

Next, the surface of the base coat layer is coated with a vacuum degree of 5 using a vacuum evaporation method.
An aluminum plating layer was formed by 500 people under the condition of x10-6T0rr to obtain a metal plating body. Example 4 Using the resin solution of Example 1, the surface of a cold-rolled steel plate that had been polished and cleaned was spray-painted to a dry film thickness of 30 microns, and after setting for 10 minutes at room temperature, the lamp input was 160 W/C!
! A base coat layer was obtained by irradiating for 30 seconds using a single L high-pressure mercury lamp at an irradiation distance of 20 degrees.

Next, the surface of the base coat layer is coated with a vacuum degree of 1 using a vacuum evaporation method.
An aluminum plating layer was formed by 300 people under the conditions of x10-6T0rr to obtain a metal plating body. Comparative Example 1 A base coat layer was obtained using a resin liquid having the same composition as in Example 1 and using the same procedure.

Next, the surface of the base coat layer is coated with a vacuum degree of 1 using a vacuum evaporation method.
An aluminum layer of 500λ was formed under the conditions of X10-4T0rr to obtain a metal-plated body. Comparative Example 2 A base coat layer was obtained using a resin liquid having the same composition as in Example 2 and using the same procedure.

Next, the surface of the base coat layer is coated with a vacuum degree of 5 using a vacuum evaporation method.
An aluminum layer having a thickness of 500λ was formed under the conditions of ×10 −5 T0rr to obtain a metal-plated body. Comparative Example 3 A base coat layer was obtained using a resin liquid having the same composition as in Example 3 and using the same procedure.

Next, an aluminum layer of 500 mm was formed on the surface of the base coat layer by vacuum evaporation at a vacuum degree of 7.times.10@-5 T0rr to obtain a metal-plated body. The results of comparative evaluation of the effects using the metal plated bodies obtained in Examples 1 to 4 and Comparative Examples 1 to 3 are as follows.

Test method (1) Appearance; brightness of the surface of the metal plating layer of the metal plating body,
Visually judge whether the smoothness is good or bad.

(2) Heat resistance: The metal plated body was left in a circulating hot air electric furnace at 180°C for 60 minutes, and after a specified period of time, the test piece was taken out of the furnace, allowed to cool naturally, and then the condition of the surface of the metal plated layer was visually judged.

(3) Adhesion: After pressing a cellophane tape with a width of 20 m/m and a length of 30 m/m on the surface of the metal plating layer and forcibly peeling off the cellophane tape, the area of the metal plating layer remaining on the surface of the base coat layer per the area Read.

It is clear from the comparative test results table that the test specimens obtained by the method of the present invention are excellent in appearance, heat resistance, and adhesion. Very useful as a mirror.

Claims (1)

[Claims] 1. On the metal surface, (i) epoxy modified acrylic resin and/or polyester modified acrylic resin 50% to 90% by weight
and (ii) 0.0 parts by weight per 100 parts by weight of the resin liquid.
After applying a composition consisting of 5 to 15 parts by weight of a photosensitizer, the film was solidified by irradiation with ultraviolet rays to form a base coat layer, and then 1 x 10^-^5
A method for manufacturing a lighting reflector with excellent heat resistance, which comprises forming an aluminum plating layer by performing vacuum deposition at a vacuum degree of Torr or higher.