JP3346505B2 - Manufacturing method of mirror surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a mirror body.

[0002]

2. Description of the Related Art Mirrors formed by applying a pigment to one surface of glass are widely used, but there is a problem that glass is easily broken. A mirror polished on the surface of a metal, for example, stainless steel, is hard to break, but when used for a long period of time, rust or fogging is likely to occur, and the polishing cost for finishing the metal surface to a mirror surface is high.

[0003] Paints containing aluminum powder have been used for metallic finishing of automobiles, but not for the manufacture of mirrors. JP 3-95275 relates to compositions for reflective automotive coatings. This publication describes a method of increasing the reflectance of a surface coated with paint, but this publication discloses a method in which paint is applied to one surface of a transparent body and light incident on a surface not coated with paint is applied. No mention is made of a mirror forming a mirror surface.

[0004]

Conventional methods for manufacturing a mirror-like body include a method of plating a metal (such as Cr) and a method of vacuum-depositing Al. These methods require large-scale and expensive equipment. .

An object of the present invention is to provide a method for manufacturing a mirror body by a simple coating, in which glass can be used as a material for forming a mirror surface and a plastic resin or the like can be used.

[0006]

According to the present invention, the thickness of aluminum is 0.1 to 2.0 μm and the diameter is 0.5 to 20 μm.
1 to 5% by weight of an aluminum pigment containing 80% or more of flaky aluminum having a size of 0 μm;
90% to 97% by weight of a solvent mixture obtained by mixing a low boiling solvent having a boiling point of 70 to 100 ° C, a medium boiling solvent having a boiling point of 100 to 150 ° C, and a high boiling solvent having a boiling point of 150 ° C or more.
Containing, if necessary, a paint further containing an additive for raising the orientation of the flaky aluminum, after applying to one side of a transparent material, a baking step of holding at a temperature of 50 to 100 ° C. for 10 to 30 minutes; and And a post-curing step of holding the coating at room temperature for 10 hours or more to form a mirror surface with respect to light incident on a surface of the transparent material on which the paint is not applied. According to the knowledge of the present inventors, a rosin acid ester is effective as an additive for increasing the orientation of flaky aluminum, and it is preferable to contain 0.5% of the rosin acid ester.

The aluminum pigment used in the present invention contains at least 80% of flaky aluminum having a thickness of 0.1 to 2.0 μm and a diameter of 0.5 to 200 μm as aluminum. As this aluminum pigment, for example, SPAL-18, a trade name of Parker Corporation, can be used.

In the present invention, the aluminum pigment is used in an amount of 1 to 5
Use by weight%. If it is less than 1%, the reflectance of the obtained mirror surface is insufficient. It is sufficient to contain 5% of the aluminum pigment, and if it is contained more than that, there is no further improvement in the reflectance of the mirror surface.

The coating composition of the present invention contains 2 to 5% by weight of a binder.
contains. As the binder, for example, one or a mixture of two or more selected from acrylic resin binders can be used. When the amount of the binder is less than 2% by weight, the adhesion of the coating film forming the mirror body becomes insufficient. However, the content of the binder of 5% is sufficient, and if it is contained more than that, there is no particular effect.

The solvent mix of the present invention has a boiling point of 70 to 1
Use a low boiling point solvent of 00 ° C. Acetone / ethyl acetate /
Since methyl ethyl ketone and the like have a boiling point of 70 to 100 ° C., one or more of these can be used as the low boiling point solvent of the present invention. In the present invention, the boiling point is 10
Using 0 to 150 ° C. boiling point solvent in the but, butyl acetate, butyl alcohol, etc. boiling point of 100 to 150 ° C., can be used as a mid-boiling solvent one or more of this like. In the present invention, a high-boiling solvent having a boiling point of 150 ° C. or higher is used, but butyl cellosolve / diacetone alcohol or the like has a boiling point of 150 ° C. or higher, and one or more of these can be used as a high-boiling solvent. .

In the present invention, a low-boiling solvent, a medium-boiling solvent, and a high-boiling solvent are mixed to form a solvent mix. : 1: 1 is preferred. As will be described later, in the present invention, a mirror surface is formed by orienting each of the flaky aluminum in parallel with the painted surface, but if the sum of the blending ratio of the low boiling solvent and the medium boiling solvent is less than 50%, the flaky aluminum is formed. Orientation is insufficient, and the reflectance when a mirror surface is formed becomes insufficient.

When the mixing ratio of the medium boiling solvent and the high boiling solvent is 80
%, It is not preferable because the time of a baking step and a post-curing step described later is unnecessarily extended. According to the findings of the present inventors, in order to ensure a sufficient reflectance,
Drying is promoted in order to prevent evaporation of the solvent due to its affinity with the vehicle and suppression of diffusion due to high viscosity, so as to prevent evaporation from becoming very slow and remaining in the coating film. The coating thickness of the product forming the mirror surface is preferably 3 to 10 μm.

In the present invention, a low-boiling solvent, a medium-boiling solvent and a high-boiling solvent are mixed to form a solvent mix.
A paint is formed by mixing about 97 parts by weight with the aluminum pigment and the binder. This paint is applied to one surface of a transparent material such as glass or a plastic resin plate. This application can be performed by, for example, spraying.

After spray coating, a baking step of maintaining the temperature at 50 to 100 ° C. for 10 to 30 minutes and a post-curing step of maintaining the temperature at room temperature for 10 hours or more are sequentially performed to form a mirror body.

FIG. 1 is an explanatory diagram of an example of transition of the properties of a coating film in the heat treatment of the present invention. In the example of FIG. 1, about 90% of the solvent evaporates in the printing step, and the luminance reaches 45% or more. In the post-cure step, the upper limit of the burn-in step time is sufficient for 30 minutes because the luminance is further increased. In the post-curing step, the evaporation of the solvent further proceeds, and the luminance becomes 50% or more after 24 hours, for example. The method of measuring the luminance indicates a value obtained by measuring the regular reflectance with a mirror reflectometer (TD-1100AD, manufactured by Tokyo Denshoku Co., Ltd.) in FIG.

[0016]

FIG. 2 is an explanatory view of an example of the distribution of flaky aluminum according to the present invention, wherein A is the time when the spray coating is completed, B is the time when the baking step is completed, and C is the time when the post-curing step is completed.
As shown in FIG. 2 (A), immediately after the paint is applied by spraying, the flaky aluminum 3 is not aligned and oriented. In the baking step in FIG. 2 (B), due to the high temperature, the medium-boiling solvent and the high-boiling solvent also begin to evaporate, and the flaky aluminum is aligned.
Brightness is improved. Also, by curing the binder,
(Transparent material) adheres to the scale aluminum.

In FIG. 2 (C), as the post-curing step proceeds, the high boiling point solvent also completely evaporates, the alignment of the flaky aluminum is completed, and the base material and the flaky aluminum further adhere to each other to increase the brightness. In addition, the thermal expansion during the baking process returns to its original state at this stage, and the base material and the coating film become denser, further increasing the brightness. At this stage, the flaky aluminum layer forms a reflective surface with respect to the incident light 4 on the surface of the transparent material 1 on which the paint 2 is not applied, and a specular body having a luminance of 50% or more is obtained.

[0018]

According to the present invention, glass can be used, and a mirror-like body can be easily manufactured by using another flexible transparent body (such as plastic resin) which is hardly damaged. The mirror according to the present invention is hardly rusted and hardly fogged.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a heat treatment of the present invention.

FIG. 2 is an explanatory diagram of the distribution of flaky aluminum of the present invention.

FIG. 3 is an explanatory diagram of a luminance measuring device.

[Explanation of symbols]

1: transparent material (substrate), 2: coating film, 3: flaky aluminum, 4: incident light.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Issei Abe 123 Minamigotani, Yashio-shi, Saitama Nagashima Specialty Coatings Co., Ltd. Saitama Factory (72) Inventor Masazumi Yamaguchi 2-12-6 Nihonbashi, Chuo-ku, Tokyo, Japan (56) References JP-A-3-95275 (JP, A) JP-A-54-106541 (JP, A) JP-A-57-81201 (JP, A) JP-A-2-78546 ( JP, A) JP-A-5-93166 (JP, A) JP-A-59-223758 (JP, A) JP-A-61-209280 (JP, A) JP-A-56-172805 (JP, U) (58) ) Field surveyed (Int.Cl. ⁷ , DB name) C09D 1/00-10/00 C09D 101/00-201/10 B29D 9/00 B32B 1/00-35/00 A47G 1/00-1/24 C08J 7/04-7/06

Claims (3)

(57) [Claims] 1. The thickness of aluminum is 0.1 to 2.0.
1 to 5% by weight of an aluminum pigment containing 80% or more of flaky aluminum having a diameter of 0.5 to 200 μm and a binder of 2 to 5% by weight, and a boiling point of 70 to 10
The 0 ℃ low boiling point solvent and a boiling point that Yusuke contains a solvent mix 90 to 97% by weight boiling point solvent and a boiling point mixed solvent having a high boiling point of more than 0.99 ° C. in a 100 to 150 ° C. paint, one side of the transparent material After applying to a temperature of 10 to 3
A mirror surface formed by sequentially performing a baking step of holding for 0 minutes and a post-curing step of holding for 10 hours or more at room temperature to form a mirror surface with respect to light incident on a surface of the transparent material where the paint is not applied. How to make the body. 2. The coating composition according to claim 1 , further comprising :
Coating containing rosin acid ester as an additive
The mirror-like body according to claim 1, wherein
Production method. In at 3. one or more low-boiling solvent is selected from acetone, ethyl acetate, methyl ethyl ketone, one or more mid-boiling solvent is selected et or butyl acetate, butyl alcohol, high boiling The solvent is one or more selected from butyl cellosolve diacetone alcohol, and a low-boiling solvent in a solvent mix: a medium-boiling solvent:
3. The method according to claim 1 , wherein the compounding ratio of the high boiling point solvent is 1 to 2: 1: 1 by weight.