JPS5929108B2 - Manufacturing method of metal plated body - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a metal plated body.

More specifically, the present invention relates to a method of obtaining a high-brightness metal plated body by forming a metal plating layer on a metal surface by vacuum evaporation or sputtering. A method is already known in which metals such as aluminum, copper, chromium, nickel, or alloys thereof are used on the surface of a metal molded product, and metal plating is performed by vacuum evaporation, sputtering, or the like.

However, according to such conventional methods, a metal plating layer is formed directly on the surface of the metal adherend, but since the thickness of the metal plating layer is extremely thin, less than 1 micron, the surface may be scratched or lack smoothness. As a result, the appearance was extremely poor, and the adhesion between the bare surface of the adherend and the metal plating layer was extremely poor, resulting in the metal plating layer often coming off. Therefore, in order to compensate for these defects, it is common to interpose a resin film with a thickness of about 30 to 50 microns as a base coat layer between the bare surface of the adherend and the metal plating layer, and form a metal plating layer on the surface of the resin film. It has been adopted. For the base coat layer, a resin liquid prepared by dissolving melamine alkyd resin, melamine-acrylic resin, acrylic resin, etc. in an organic solvent is used as a raw material, and these are spray-painted and
The layer was solidified by heat treatment at 0 to 180° C. for about 30 minutes. However, such a method requires heat treatment at high temperature for a long time, which requires a huge amount of thermal energy, and is not preferred from the viewpoint of production efficiency.

Furthermore, since it contains a large amount of organic solvent, it is difficult to obtain a sufficient film thickness, which results in poor finished appearance of the metal plated body, and in addition, there is a lot of waste from the perspective of resource conservation. In recent years, from the viewpoint of solving the above-mentioned problems, many attempts have been made to apply a resin liquid of a polymer compound having unsaturated groups and to efficiently treat it in a short time using ionizing radiation or electromagnetic wave energy. ing.

However, due to various difficulties, this method has hardly reached the stage of practical use. One of the problems will be described using the headlamp reflector of an automobile as an example.

First of all, the reflecting surface of this type of reflecting mirror usually consists of an aluminum plating layer formed by vacuum evaporation. In the process of attaching the reflector to the vehicle body, it is necessary to solder one end of an electric circuit cord to the back surface of the reflector, or to perform waterproofing and sealing with an adhesive. In this case, it is of course inevitable that the product will be heated locally or in its entirety. As a result, a multicolored rainbow pattern or wrinkles appear on the surface of the aluminum plating layer, which is the reflective surface, and the original shine of the aluminum plating disappears.
In other words, it causes diffuse reflection, which makes it unable to function as a headlamp reflector. The present inventor has previously proposed a method for manufacturing metal-plated bodies that solves these problems, brings the use of ionizing radiation or electromagnetic wave energy to a practical stage, and has high production efficiency with short processing times.

(Patent application No. 53-33498 and Patent application No. 53-35883
) However, the biggest problem in the manufacturing process of automobile headlamp reflectors as mentioned above, for example, is that the hub is polished seven to eight times to remove press scratches on the bare surface and increase the brightness of the plating layer. This is the current situation, and as the demand for high-brightness plated products increases in the future, it will be necessary to increase the number of times the hub process is performed. In order to reduce the number of work steps in the hub polishing process, it is sufficient to form a base coat layer with a thickness necessary to fill the press scratches, but in order to fill the scratches on the bare surface, it is necessary to Although it depends, a thickness of approximately 80 to 100 microns is required.

Therefore, in order to obtain the required film thickness by overcoating the resin clear, it is necessary to apply it quite a number of times.Especially with the current high-temperature baking type resin clear mentioned above, each time requires high energy and a long time, which reduces production efficiency. Not only is this undesirable from the point of view of overbaking, but overbaking also causes thermal deterioration of the lower layer film and decreases the mutual adhesion between the layers. The present invention aims to solve the above-mentioned problems and provide a method of manufacturing a metal-plated body with high production efficiency, which can be performed in a short time and omit the hub polishing step.

That is, the present invention provides (a) on a metal surface, (b) a pigment selected from talc, silica, barium sulfate, and calcium carbonate;
) An ultraviolet curable resin liquid containing a photosensitizer and having as a basic component a polymerizable polymer and/or a polymerizable oligomer containing a phosphorous element in the molecule, or (Ii) a polymerizable polymer and/or a polymerizable oligomer. A step of forming a primer coat layer by applying a mixture of a polymerizable monomer containing a phosphorus element and a phosphorus element in the molecule as basic components and an ultraviolet curable resin liquid containing a photosensitizer; b) On the uncured primer coat layer, apply an ultraviolet curable composition consisting of a resin liquid containing no pigment and having at least one unsaturated group in the molecule, and a photosensitizer (however, an ultraviolet curable composition containing a photosensitizer) is applied on the uncured primer coat layer. (excluding those) to form a base coat layer, and then irradiating ultraviolet rays to simultaneously solidify the primer coat layer and the base coat layer, and (c) heat-treating the base coat layer, and then curing the base coat layer surface The present invention relates to a method for producing a metal-plated body, which comprises a step of forming a metal-plated layer by vacuum evaporation or sputtering.

The present invention will be explained in more detail below. The resin liquid used in the primer coat of the present invention has (i) a polymerizable polymer and/or a polymerizable oligomer having a phosphorus element as a basic component, and optionally a polymerizable monomer having a phosphorus element, etc. An ultraviolet curable composition formed by mixing a polymerizable monomer, an organic solvent, other photosensitizers, etc., or (4)
Ultraviolet rays whose basic components are a polymerizable polymer and/or a polymerizable oligomer and a polymerizable monomer containing a phosphorus element, mixed with other polymerizable monomers, organic solvents, other photosensitizers, etc. as necessary. It is a curable composition, where polymerizable means that it has at least one unsaturated group in its molecule.

The composition (4) is most preferred in view of adhesion to active metal surfaces such as chromate-treated bare surfaces and galvanized base surfaces.

When the above-mentioned (1) polymerizable polymer and/or polymerizable oligomer containing phosphorus element is used as a basic component, 50% by weight or less of the phosphorus element-containing polymerizable monomer and/or as necessary in the entire resin liquid composition. Or other polymerizable monomers can be contained.

However, when a polymerizable monomer containing 7 phosphorus elements is used in combination, the monomer is in a range of 1 to 30% by weight in the total composition of the resin liquid.
In addition, the above (Ii) polymerizable polymer and/or polymerizable oligomer 1 (a) and a polymerizable monomer b containing the phosphorus element
When using as the basic component, the ratio of both is (a)/(b)
-99/1 to 70/30 (wt%), preferably 95/
5 to 80/20 (wt%), and if necessary, add polymerizable monomers other than the group to ) can be added within a range of 50% by weight or less.

More specifically, the polymerizable polymer and/or
Or oligomer is a polymer and/or oligomer having at least one or more unsaturated group in the molecule, such as unsaturated polyester resin, unsaturated acrylic resin,
Examples include polyester-modified acrylic resins, epoxy-modified acrylic resins, urethane-modified acrylic resins, alkyd-modified acrylic resins, unsaturated group-containing polyolefin resins, and drying oils.

As an unsaturated polyester resin, Rigorak 2460
u (Showa Kobunshi), Polylite CH-303 (Dainippon Ink), and as unsaturated acrylic resin, Diabeam K-
8303 (Mitsubishi Rayon), polyester modified acrylic resins include Aronix M8O3O, Aronix M
8O6O (Toagosei Chemical Industry Co., Ltd.), etc. In addition, as the epoxy-modified acrylic resin, monomers having UcOat unsaturated groups, such as (a) monomers containing (meth)acryloyl groups, (c) monomers containing aromatic vinyl groups, or (c) aliphatic vinyl groups are used. Containing monomer.

Among the above (a), further hydroxyl group-containing monomers include 2
-Hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. Examples of ether compounds of the hydroxyl group-containing monomer and alkyl alcohol or cyclic alkyl alcohol include methoxyethyl (meth)arylate, ethoxyethyl (meth)acrylate, and tetrahydrofurfuryl acrylate. Furthermore, ester compounds of (meth)acrylic acid and alkyl alcohol include methyl (meth)acrylate, butyl (meth)acrylate, neopentyl glycol di(meth)acrylate, 1-6 hexanediol di(
These include meth)acrylate, trimethylolproban tri(meth)arylate, etc. In addition, examples of the aromatic vinyl group-containing monomer (b) include styrene, vinyltoluene, etc., and vinyl acetate, vinylidene chloride, etc. are used as the aliphatic vinyl group-containing monomer (c), respectively. .
Particularly preferred among the above polymerizable monomers are ether compounds of the hydroxyl group-containing monomer and alkyl alcohol in the group (a), and the hydroxyl group-containing monomer (
It is an ester compound of meth)acrylic acid and alkyl alcohol.

In the present invention, by using a resin liquid containing phosphorus as the primer coat, the adhesion of the primer coat to the metal surface can be significantly improved, and as a result, physical and chemical properties such as corrosion resistance can be improved. It can be done.

The primer coat layer of the present invention uses a pigment selected from talc, silica, barium sulfate and calcium carbonate. The pigment is preferable because it does not inhibit the curing of the primer coat layer with ultraviolet rays and has the effect of imparting thixotropy to the mixture with the resin liquid.

Of course, these pigments may be used as a mixture of two or more.

The mixing ratio of the resin liquid and pigment is determined depending on the amount of oil absorption of the pigment (
Although not particularly limited as it varies depending on the bulk specific gravity, the ratio is preferably 5 to 200 parts by weight of the pigment per 100 parts by weight of the resin liquid.

In order to obtain the mixture of the resin liquid and pigment, they are mixed using a known dispersing machine such as a roll mill, a disk mill, a sand mill, a ball mill, etc.

On the other hand, the resin liquid having at least one unsaturated group in the molecule used in the base coat layer of the present invention has a polymerizable polymer and/or a polymerizable oligomer as a basic component, and if necessary, An ultraviolet curable composition formed by mixing a polymerizable monomer, an organic solvent, and other photosensitizers (however,
(excluding thermosetting materials).

The polymerizable polymer and/or polymerizable oligomer used herein refers to a polymer and/or oligomer having at least one unsaturated group in the molecule used to obtain the primer coat layer. All are usable. Particularly preferably, epoxy-modified acrylic resin and/or
Or polyester modified acrylic resin. Furthermore, as the polymerizable monomer used as an optional component, all of the other polymerizable monomers (a), (b), and (c) used to obtain the primer coat layer can be used. be. Particularly preferred are ether compounds of hydroxyl group-containing monomers in group (a) and alkyl alcohols, and ester compounds of (meth)acrylic acid and alkyl alcohols.

In the base coat layer of the present invention, as mentioned above, an epoxy-modified acrylic resin or a polyester-modified acrylic resin is used as the polymerizable polymer and/or oligomer, and a polymerizable monomer containing a (meth)acryloyl group is used as the polymerizable monomer. Preferably, a resin solution containing 10 to 50 parts by weight of the polymerizable monomer to 90 to 50 parts by weight of the polymerizable polymer and/or oligomer is preferable from the viewpoint of the smoothness of the base coat layer surface, coating properties, etc. Most preferred is a mixture of

These above-mentioned polymerizable polymers and/or oligomers,
The polymerizable monomer is not limited to only one type, but it is also possible to use two or more types in combination to bring out the characteristics of each.

The "resin liquid" used in the primer coat layer and the base coat layer of the present invention has a polymerizable polymer and/or oligomer as a basic component, and the polymerization may be carried out as appropriate depending on the difficulty of the coating work, the surface condition of the coating film, etc. It is made by adjusting the viscosity and properties of the resin liquid by combining it with a synthetic monomer. In particular, when a low viscosity resin liquid is required, an organic solvent is also used. Furthermore, in the present invention, since ultraviolet rays are used as an energy source for solidifying the resin liquid, it is necessary to add a photosensitizer to the resin liquid.

Examples of the photosensitizer include benzoin, benzoin methyl ether, benzoin isopropyl ether, benzyl, benzophenone, anthraquinone, naphthoquinone, chloranthraquinone, tetramethylthiuram disulfide,
Examples include diphenyl disulfide, 2,2-diethoxyacetophenone, benzoin peroxide, azobisisobutyronitrile, 2,2'-azobisproban, etc., and the amount used is determined based on the polymerizable polymer and 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 amount of oligomer and polymerizable monomer.

Other additives such as a leveling agent, a polymerization inhibitor, and an anti-sagging agent may be added to the resin liquid of the present invention as necessary.

In the method for producing a metal plated body of the present invention, the mixture of the resin liquid and pigment is first coated as a primer coat layer on the metal surface by a known method such as a roll coater, a spray curtain flow coater, or a brush coater to obtain a desired film thickness. , preferably 6
Apply to a thickness of about 0 to 80 microns.

A base coat layer can be applied immediately after coating, but for leveling of the primer coat layer, or especially for primer coat layers containing organic solvents,
It is preferable to leave it at room temperature for an appropriate period of time or to forcibly heat it. Next, the pigment-free resin liquid is applied to the surface of the uncured primer coat layer in the same manner as described above to a desired thickness, preferably about 20 to 30 microns, and then the primer is irradiated with the ultraviolet rays described above. The coat layer and base coat layer are solidified.

One of the features of the present invention is the heat treatment after solidification by irradiation with ultraviolet rays, that is, the treatment method before the step of forming a metal plating layer, which will be described later. To emphasize, this heat treatment significantly improves the heat resistance of the metal plating layer, making it possible to prevent the occurrence of multicolored rainbow patterns, wrinkles, etc. as described above. The heat resistance of the metal-plated body obtained by the conventional method, that is, the process without the heat treatment characteristic of the present invention, was extremely poor.

This is also the main reason why it has not been practical to use a base coat layer that has been solidified by irradiation with ionizing radiation and/or electromagnetic wave active energy. To explain further, the present inventor conducted various studies on the causes of defects in conventional methods, and as a result, discovered that the cause was a trace amount of polymerizable monomer remaining in the coating film after solidification. . Therefore, an attempt was made to extend the irradiation time of ultraviolet rays as a method for removing the residual monomer, but no favorable results were obtained. Therefore, they diligently tried various methods and arrived at the unexpectedly simple processing method of the present invention. The heat treatment of the present invention consists of treatment at a temperature of 60 to 200'C for about 1 to 15 minutes. Regarding the relationship between heating temperature and time, when the temperature is low, a long time is required, and when the temperature is high, a short time is sufficient. Therefore, although there is no intention to uniformly limit the time and temperature, low-temperature and short-time heat treatment is desirable from the viewpoint of saving thermal energy and production efficiency.

Furthermore, without being bound by theory, it is believed that this heat treatment mainly involves the dissipation of residual monomers as described above, and also includes partial polymerization and further prevention of moisture absorption in the coating film after heat treatment.

Furthermore, considering this, it is understood that it is preferable to carry out the process immediately before vacuum evaporation or sputtering. The equipment heat source for the heat treatment may be a commonly known method.

For example, any of an infrared lamp, kerosene, heavy oil, combustion gas such as Provan gas or Tofu gas, or an electric heater may be used. This heat treatment significantly improves the heat resistance of the metal plated body and also significantly improves the adhesion between the bare metal surface and the base coat layer. In the method of the present invention, a metal plating layer with a thickness of about 1 micron or less made of metals such as aluminum, chromium, nickel, copper, and alloys thereof is then formed on the surface of the base coat layer by a vacuum evaporation method or a sputtering method. do.

The thus obtained product, a metal plating body, has excellent heat resistance, and does not exhibit multicolored rainbow patterns, wrinkles, cracks, etc. even when heated. In addition, since the metal plating layer of the metal plating body obtained by the present invention is an extremely thin film, the same material as used in the present invention is applied to the surface of the metal plating layer for the purpose of protecting the plating layer and preventing surface contamination. Apply a resin liquid and solidify it by irradiating it with active energy using commonly used ionizing radiation and/or electromagnetic waves as an energy source, or use melamine-alkyd resin, acrylic-alkyd resin, acrylic resin, etc. It is also possible to form a final product by coating and solidifying a room temperature curing resin liquid such as a thermosetting resin liquid, polyurethane resin, or epoxy resin. Next, the present invention and its specific effects will be explained by giving examples.

However, "part" or "%" indicates "part by weight" or "% by weight."

Example 1 An automobile headlamp was prepared by applying chromate treatment to the above primer coat layer composition A-1, which had been viscously adjusted with a mixed solvent of equal amounts of xylol trimethyl isobutyl ketone (foad cup 1+4 measured viscosity for 40 seconds) and omitted hub polishing. The surface of the reflector material was spray coated to a dry film thickness of 60 microns, and set at 50° C. for 20 minutes to scatter the solvent to obtain a primer coat layer.

Next, on the primer coat layer, resin liquid B-1 for base coat layer whose viscosity was adjusted with the mixed solvent (Food Cup≠4 measured viscosity 40 seconds) was spray-coated to a dry film thickness of 20 microns, and the mixture was coated for 10 minutes at room temperature. After setting for a minute, irradiation was performed for 60 seconds at an irradiation distance of 20 CfTL using one high-pressure mercury lamp with a lamp input of 160 W/mine.

Next, after heat treatment was performed for 15"C x 5 minutes in a hot air drying oven, vacuum evaporation was performed at a vacuum degree of 1 x 10 -4 T0rr to obtain a 500 aluminum metal film.

Example 2 The viscosity of the composition A-2 for a primer coat layer was adjusted in the same manner as in Example 1, and after spray painting on the surface of the same material, it was set for 30 minutes at room temperature to obtain a primer coat layer.

Next, the viscosity of the resin liquid B-2 for the base coat layer was adjusted in the same manner, and spray coating was applied. After setting in a hot air drying oven at 50°C for 5 minutes, irradiation was performed with one high-pressure mercury lamp with a lamp input of 160 W/(V7!). Irradiation was performed for 60 seconds at a distance of 20 cm.

Next, a heat treatment was performed in a hot air drying oven at 100° C. for 10 minutes, and then vacuum deposition was immediately performed at a vacuum degree of 1 to 4 T0rr to obtain a 500 aluminum metal film.

Example 3 [Composition A-3 for primer coat layer] The composition A-3 for primer coat layer was applied and set in the same manner as in Example 1 to the surface of the same material as in Example 1 to obtain a primer coat layer. Ta.

Next, base coat layer resin liquid B-3 was applied and solidified in the same manner as in Example 1, and then dried at 80°C x 1 in a hot air drying oven.
Heat treatment for 5 minutes and immediately reduce vacuum to 1×10-4T0
A 500A aluminum metal film was obtained by vacuum evaporation using RR. Example 4 The viscosity of the primer code layer composition A-4 was adjusted in the same manner as in Example 1, and after spray painting on the surface of the same material to a dry film thickness of 60 microns, it was set at room temperature for 30 minutes to form the primer coat layer. I got it.

Next, the viscosity of the resin liquid B-4 for the base coat layer was adjusted in the same manner, and the dry film thickness was sprayed to 20 microns, and after setting in a hot air drying oven for 5 minutes, the lamp input was 16.
0W/(Irradiation distance 20 with one V7l high pressure mercury lamp)
C:T! It was irradiated with L for 60 seconds.

Next, a heat treatment was performed at 100° C. for 10 minutes in a hot air drying oven, and then vacuum deposition was immediately performed at a vacuum degree of 1 to 4 T0rr to obtain a 500A aluminum metal film. Example 5 The viscosity of the primer coat layer composition A-5 was adjusted in the same manner as in Example 1, and after spray painting on the surface of the same material to a dry film thickness of 60 microns, it was set at 50° C. for 20 minutes and treated with a solvent. was scattered to obtain a primer coat layer.

Next, the viscosity of the resin liquid B-5 for the primer coat layer was adjusted in the same manner, and the dry film thickness was sprayed to 20 microns. After setting for 10 minutes at room temperature, the lamp input was 160 W/
Irradiation distance of 20? with one CTn high pressure mercury lamp? So 60
Irradiated for seconds.

Next, a heat treatment was performed at 150° C. for 5 minutes in a hot air drying oven, and immediately vacuum deposition was performed at a vacuum degree of 1 to 4 T0rr to obtain a 500-layer aluminum-earth metal film. Comparative Example 1 The composition A-6 for a primer coat layer was applied to the surface of the same material as in Example 1 in the same manner as in Example 1 to obtain a primer coat layer.

Next, resin liquid B-1 for base coat layer was applied and solidified in the same manner as in Example 1, and then heat treatment and aluminum vacuum evaporation were performed.

Comparative Example 2 A composition obtained by removing the fine powder silica from the primer coat layer composition A-2 and changing xylene to 10 parts and methyl isobutyl ketone to 10 parts was applied in the same manner as in Example 2 to form a primer coat layer. I got it.

Next, base coat layer resin liquid B-2 was applied and solidified in the same manner as in Example 1, followed by heat treatment and aluminum vapor deposition.

Comparative Example 3 A composition in which silica and talc were removed from the primer coat layer composition A-3, xylol was changed to 10 parts, and methyl isobutyl ketone was changed to 10 parts, and the base coat layer resin liquid B-3 was used. Then, in the same manner as in Example 3, coating, heat treatment after solidification, and vacuum vapor deposition of aluminum were performed.

Comparative Example 4 The composition A-7 for a primer coat layer was applied and set on the surface of the same material as in Example 1 in the same manner as in Example 1 to obtain a primer coat layer.

Next, base coat layer resin liquid B-7 was applied, solidified, and heat treated in the same manner as in Example 1, and then aluminum vapor deposition was performed in the same manner. Comparative Example 5 The composition A-1 for a primer coat layer and the resin liquid B-1 for a base coat layer were applied onto the surface of the same material as in Example 1 and solidified in the same manner as in Example 1.

Aluminum was then vacuum-deposited without heat treatment.

Comparative Example 6 The composition A-2 for a primer coat layer and the resin liquid B-2 for a base coat layer were applied onto the surface of the same material as in Example 1 and solidified in the same manner as in Example 2.

Aluminum was then vacuum-deposited without heat treatment.

Comparative Example 7 The composition A-3 for a primer coat layer and the resin liquid B-3 for a base coat layer were applied onto the same material surface as in Example 1 and solidified in the same manner as in Example 3.

Claims (1)

[Scope of Claims] 1(a) A pigment selected from talc, silica, barium sulfate, and calcium carbonate on the metal surface; (b)
(i) Polymerizable polymer containing phosphorus element in the molecule and/or
or (ii) a polymerizable resin liquid containing a polymerizable oligomer as a basic component and a photosensitizer; A step of applying a mixture of a monomer as a basic component and an ultraviolet curable resin liquid containing a photosensitizer to form a primer coat layer, (b) applying a mixture containing no pigment on the uncured primer coat layer; After applying an ultraviolet curable composition (excluding thermosetting compositions) consisting of a resin liquid having at least one unsaturated group in the molecule and a photosensitizer to form a base coat layer, (c) heating the base coat layer and then forming a metal plating layer on the surface of the base coat layer by vacuum evaporation or sputtering; A method for manufacturing a metal plated body consisting of. 2 At least 1 in the molecules used in the base coat layer
The resin liquid having at least 50 to 90% by weight of a polymer and/or oligomer of an epoxy-modified acrylic resin and/or a polyester-modified acrylic resin and 50 to 1% by weight of a polymerizable monomer containing a (meth)acryloyl group
The method for producing a metal plated body according to claim 1, wherein the metal plated body is a mixture with 0% by weight. 3. The method of manufacturing a metal plated body according to claim 1, wherein the heat treatment is performed at 60 to 200°C for 1 to 15 minutes. 4. The method of manufacturing a metal plated body according to claim 1, wherein the metal plating is aluminum or an alloy thereof.