JPS63142303A - Mirror made of synthetic resin - Google Patents

Abstract

PURPOSE:To provide such characteristics as resistance to sulfurization, to chemicals, and to sweat, etc. to a mirror by forming at least one metallic protective layer by the vapor deposition process on a reflecting silver layer. CONSTITUTION:At least one metallic layer is formed by the vapor deposition process on the surface of reflecting silver layer. Since the rear side of the reflecting silver layer is covered completely by the metallic protective layer by the vapor deposition process, the protective layer has no air permeability and can be formed to the shape completely equal to the shape of the hyper fine structure of the surface, forming no interstice at all in the boundary between the protective layer and the reflecting silver layer. For example, a reflecting silver layer 3 and a metallic protective layer 4 are formed successively on the rear surface of a transparent synthetic resin plate or film 1. Al, Cu, Au, Pt, Zn, Sn, Ni, etc. may be used as the metal for forming the metallic protective layer 4. By this constitution, satisfactory resistance to sulfurization, chemical resistance, and sweat resistance, are provided to the mirror.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a mirror made of synthetic resin, and more specifically, the invention relates to a mirror made of synthetic resin, and more specifically, a silver reflective layer is formed by vacuum evaporation on a transparent synthetic resin plate or film directly or through an undercoat layer. The present invention relates to a synthetic resin mirror that has excellent properties such as sulfur resistance, chemical resistance, sweat resistance, etc., and can forever retain the luster and color tone inherent in silver.

[Prior art] As a conventional technology, for example, a transparent silicone resin or silicone-acrylic copolymer resin coating film is formed on both the front and back sides of a flat plate of transparent acrylic resin, and a silver reflective layer is formed on the back side by cold sputtering. Synthetic resin mirrors consisting of a synthetic resin backing and protective layer (for example,
No. 9) is known.

However, in conventional methods, the silver in the silver reflective layer is protected by a protective backing layer made of synthetic resin, so it is not sufficient in terms of properties such as sulfidation resistance, chemical resistance, and sweat resistance.
For example, with the silver reflective layer, the backing protective layer itself made of synthetic resin has some air permeability, so over time it may generate silver sulfide due to contact with hydrogen sulfide gas or sulfur compounds in the atmosphere, causing gradual discoloration. It's coming up.

In addition, the surface structure of the silver reflective layer formed by the vacuum evaporation method is an ultrafine structure in atomic units.1 The protective layer made of synthetic resin is either the synthetic resin molecule itself or the surface of the silver reflective layer. It is extremely large compared to the ultra-fine unit size, and the protective layer made of synthetic resin cannot completely follow the surface structure shape of the silver reflective layer, so it takes a long time. As time passes, hydrogen sulfide gas or sulfur compounds in the atmosphere cannot be prevented from entering through the fine gaps at the interface between the silver reflective layer and the backing protective layer made of synthetic resin, and as a result, hydrogen sulfide gas or sulfur compounds in the atmosphere cannot be prevented. When it comes into contact with other materials, silver sulfide is produced and the color gradually changes.

Therefore, a synthetic resin mirror using a silver reflective layer has a fatal problem in that its commercial value is significantly reduced during storage or use.

[Object of the Invention] In view of the above-mentioned conventional problems, the present invention provides an extremely superior synthetic resin mirror that is completely different from conventional synthetic resin mirrors and has properties such as extremely good sulfidation resistance, chemical resistance, and sweat resistance. Our objective is to provide resin mirrors.

[Structure of the Invention 1] That is, the present invention is a synthetic resin mirror, which has a silver reflective layer formed by vacuum evaporation on a transparent synthetic resin plate or film directly or through an undercoat layer. In the mirror, at least one or two or more metal protective layers are provided on the surface of the silver reflective layer by vacuum evaporation. With this configuration, the above-mentioned conventional problems have been completely solved.

[Function and Effect] In the synthetic resin mirror of the present invention, the back surface of the silver reflective layer is completely covered with a metal protective layer formed by vacuum evaporation, so the metal protective layer is similar to the conventional synthetic resin backing protection. It does not have air permeability like a silver reflective layer, and since it is formed using a vacuum evaporation method, it can be formed to completely follow the ultrafine structure shape of the surface of the silver reflective layer. Since even minute gaps do not occur, the silver reflective layer is not exposed to external hydrogen sulfide gas or sulfur compounds during storage or use, and therefore silver sulfide is generated and discoloration occurs. It never happens.

[Example of Embodiment] Next, the synthetic resin mirror of the present invention will be explained in detail based on the drawings.

FIG. 1 is a partially enlarged sectional view showing the basic structure of the synthetic resin mirror of the present invention. 2 to 4 are partially enlarged sectional views showing other embodiments of the synthetic resin mirror of the present invention.

The synthetic resin mirror shown in FIG. 1 has a structure in which a silver reflective layer (3) and a gold-reflective protective layer 4 are sequentially provided on the back surface of a transparent synthetic resin plate or film (1).

The synthetic resin mirror shown in Figure 2 has a structure in which a silver reflective layer (3), a metal protective layer (a), and a resin protective layer (f) are sequentially provided on the back side of a transparent synthetic resin plate or film (1). belongs to.

The synthetic resin mirror shown in Fig. 3 consists of a transparent synthetic resin plate or film (1), an undercoat layer (2), a silver reflective layer (
3) It has a structure in which a metal protective layer (1) and a resin protective layer (2) are sequentially provided.

The synthetic resin mirror shown in Fig. 4 consists of a transparent synthetic resin plate or film (1), an undercoat layer (2), a silver reflective layer (
3), a metal protective layer (a), an 84 fat protective layer (5), an adhesive (0), and a backing material (7) are provided in this order.

As is clear from the drawings, in the synthetic resin mirror of the present invention, the back surface of the silver reflective layer (3) has a dense structure that is not air permeable and is well compatible with the surface structure shape of the silver reflective layer ((g)). It is coated with a metal protective layer (a) with a circular structure.

As the transparent synthetic resin plate or film (1) in the synthetic resin mirror of the present invention, any one used in the manufacture of known synthetic resin mirrors may be used. For example, polyester resin, acrylic resin, polyamide resin, polyamideimide resin, polyethylene resin, polypropylene resin, cellulose acetite resin, polycarbonate resin, polyvinyl chloride resin, resin resin, etc. A film-like material or a plate-like material such as carbon-based resin is used as appropriate. For example, a film-like material of the above-mentioned resins with a thickness of about 4 to 1000 u is used! It is preferable to manufacture a synthetic resin mirror without 3I or cracks because it can be mass-produced continuously.

As the undercoat BI2 in the synthetic resin mirror of the present invention, any of those used in the manufacture of known synthetic resin mirrors can be used. For example, as the undercoat for forming the undercoat layer (2), the base film (1 ), and has good adhesion with the silver reflective layer (3) formed thereon, and it is desirable that the base film is not subject to excessive heat burden, all of which are satisfied. Examples of the adhesive include epoxy-isocyanate resin, melamine-acrylic resin, and silicone-acrylic resin. Undercoat layer (
2) is carried out by applying a primer made of epoxy-isocyanate resin or the like by a conventional coating method such as a roll coating method, a gravure coating method, a reverse coating method, or a spray coating method, followed by drying. The thickness of the undercoat layer (2) is usually 0.
It is selected from the range of 2 to 51 μm, more preferably 0.5 to 4 μm. If the thickness is less than 0.2 μm, it is difficult to completely and uniformly cover the surface of the base film (11), the adhesion effect cannot be sufficiently exerted, and there is no value in forming the undercoat layer (2). If it exceeds this, the undercoat layer (2) will be too thick and it will be difficult to form a uniform undercoat layer, and the drying rate will be slow and the aging rate will be poor.

In the synthetic resin mirror of the present invention, the silver reflective layer (3) is usually 3
It is selected from the range of 0 to 1oon-, preferably from 40 to 60n-. If the thickness of the silver reflective layer (3) is less than 3 on-, the light reflectivity of the silver reflective layer (3) will not be sufficient, and sufficient specular gloss will not be obtained, which is not preferable. On the other hand, even if IQOn* is exceeded, the light reflectivity of the silver reflective layer (3) does not change, so it has no effect on metallic luster and is not preferred from the economic point of view.

The silver reflective layer (1) in the synthetic resin mirror of the present invention includes all silver vapor-deposited thin films formed by conventional metal thin film forming methods such as vacuum deposition, sputtering, and ion blating.

The metal layer in the synthetic resin mirror of the present invention has a thickness of usually 35 nm or more, preferably 50 to 10 fnm (metal layer 1ffi).
If it is less than 1100n, the gas permeation barrier property of the metal protective layer (2) will not be sufficient, and the silver reflective layer (3) will not be able to be sufficiently shielded and protected from hydrogen sulfide gas or sulfur compounds. Even if it exceeds the limit, the gas permeation barrier properties of the metal protective layer (1) will hardly change, so it is not necessary and is not preferred from an economic point of view.

Examples of metals forming such a metal protective layer (1) include aluminum, copper, gold, platinum, zinc, tin, nickel, titanium, chromium, indium, gallium, tantalum, silicon,
Nickel-chromium etc. are used, and gas permeation f! From the viewpoint of durability and economy, aluminum, titanium, chromium,
Nickel-chromium and the like are preferred.

The resin protective layer in the synthetic resin mirror of the present invention has good adhesion with the metal protective layer (2) and has the ability to protect the metal protective layer (2) from damage caused by abrasion and oxidation. It is desirable that 1) be one that does not impose an extra heat burden. Suitable paints include, for example, epoxy-isocyanate resins, melamine-acrylic resins, silicone-acrylic resins, polyester resins, and nitrocellulose resins. The resin protective layer (5) is formed by applying these protective layer paints by a conventional coating method such as a roll coating method, a gravure coating method, a reverse coating method, a spray coating method, etc., and drying. Resin protective layer■
The thickness is usually in the range of 0.2 to 5μ, more preferably 0.
．． It is selected from the range of 5 to 4 μm. If the thickness is less than 0.21, the metal protective layer (a) cannot be completely covered.
The initial purpose could not be achieved, and there was no value in forming the resin protective layer (5).On the other hand, if it exceeded 5 gm, the resin protective layer (5) would be too thick and it would be difficult to form a uniform resin protective layer. This also slows down the drying speed and is inefficient. Furthermore, the coating material for the protective layer forming the resin protective layer (5) may be suitably colored with a colorant in advance.

Adhesives for the synthetic resin mirror of the present invention (for example, emulsion adhesives such as acrylic resins, vinyl acetate resins, vinyl chloride resins, polyethylene resins, and styrene-butadiene resins, either alone or in a blend);
Preferably used are solvent-based adhesives such as ethylene-vinyl acetate resin, chlorinated polypropylene resin, vinyl chloride-vinyl acetate resin, acrylic resin, and acrylic-vinyl chloride-vinyl acetate resin, either alone or in a blend. The adhesive (Q) is formed by applying an adhesive solution or the like for forming the adhesive layer (Q) by a conventional coating method such as a roll coating method, a gravure coating method, a reverse coating method, or a spray coating method.
This is done by drying. The thickness of the adhesive layer is usually in the range of 0.2 to 10 μs, more preferably 0.3 to 5 J.
Selected from the range of jJ. If the thickness is less than 0.2 μm, a sufficient adhesive effect cannot be obtained, while if it exceeds 5 gm, the adhesive layer will be too thick and the drying speed will be slow, resulting in inefficiency. Moreover, the original adhesive strength cannot be obtained, and problems such as residual solvent occur. Furthermore, the adhesive forming the adhesive layer may be appropriately colored with a coloring agent in advance.

The backing material (7) in the synthetic resin mirror of the present invention may be any material used in the manufacture of known synthetic resin mirrors, or the backing material (7) may be the transparent synthetic resin plate or film (1). ) or relatively thick and rigid, materials with sufficient self-retention properties and appropriate rigidity are usually preferably used. For example, polyester resin, polyamide resin, polyamideimide resin, polyethylene resin, polypropylene. Films, sheets or plates of resins such as resins, cellulose acetate resins, polycarbonate resins, polyvinyl chloride resins, and fluorine resins, cellophane paper, glassine paper, high-quality paper, Japanese paper, synthetic paper, cardboard, and paperboard. Thin paper or paperboard, fabrics such as nonwoven fabrics, woven fabrics, and knitted fabrics, films, sheets, or plates made of aluminum, copper, tin, stainless steel, or other metals, glass plates, plywood plates, and the like can be used as appropriate.

Such a backing material (■) often has almost the same purpose as the resin protective layer (5), that is, the function of protecting the metal protective layer (■) from damage caused by wear and oxidation, etc. Therefore, the resin protective layer (5)
It may also be provided directly on the metal protective layer (a) via an adhesive without providing any.

Furthermore, for example, on the back side of the transparent synthetic resin film (1),
A silver reflective layer (metallic protective layer) is cut into a desired size and shape and placed on a predetermined surface of the mold inner wall of one or both of the fixed mold and movable mold of an injection molding machine. A mirror may be integrally molded on the desired surface of the injection molded product by placing the mirror in advance and injection molding the resin.

Next, the present invention will be explained with reference to Examples.

[Example] Example 1 Silver was deposited on the back side of a 50μ thick polyethylene terephthalate film under a vacuum of 5 x 10-'Torr to form a 5On-thick silver reflective layer, and a 5 x 10-' silver reflective layer was formed on the back side of a 50μ thick polyethylene terephthalate film.
- Titanium is deposited under a vacuum of Torr to a thickness of 50 ns.
A homogeneous metal protective layer was formed to obtain a synthetic resin mirror of the present invention.

The resulting synthetic resin mirror had a bright silver color when viewed from the film surface.

Example 2 A polyethylene terephthalate film having a thickness of 50 µl was coated with silver under a vacuum of 5 × 10-' Torr to form a polyethylene terephthalate film having a thickness of 5
A silver reflective layer of 0n■ is formed, and a 5 x 10-' silver reflective layer is formed on it.
Copper was deposited under a vacuum of Torr to form a homogeneous first metal deposited layer with a thickness of 2 Onm, and further on top of that was a layer of 1×10
- Chromium is deposited under a vacuum of Torr to a thickness of SOnm.
A homogeneous second metal vapor deposited layer was formed to obtain a mirror made of synthetic resin.

The resulting synthetic resin mirror had a bright silver color when viewed from the film surface.

Example 3 Silver was deposited on a polyethylene terephthalate film with a thickness of 50 #Lm under a vacuum of 5 x 10-'Torr to a thickness of So.
A silver reflective layer of 50 nm thick is formed, and aluminum is deposited on it under a vacuum of 10 mm to a thickness of 50 nm.
A homogeneous metal vapor deposited layer is formed, and then a two-component curing type acrylic paint is applied on top of it, dried and cured to form a homogeneous resin protective layer with a thickness of 1.5 μl, thereby producing the synthetic resin mirror of the present invention. Obtained.

The resulting synthetic resin mirror had a bright silver color when viewed from the film surface.

Comparative Example 1 Silver was deposited on the back side of a polyethylene terephthalate film with a thickness of 50μ under a vacuum of 5 x 10-' Torr to form a silver reflective layer with a thickness of 5 (inches), and a two-component curable acrylic layer was formed on top of the silver reflective layer. A conventional type synthetic resin mirror was obtained by applying a paint and drying and curing to form a homogeneous resin protective layer with a thickness of 1.5 μm.

The resulting synthetic resin mirror had a silver color when viewed from the film surface.

The synthetic resin mirrors obtained in Examples 1 to 3 and Comparative Examples were evaluated for appearance after a sulfurization test and an artificial sweat test.

The sulfurization test was performed by leaving the sample in an atmosphere with a temperature of 20" C1 old 195% and a hydrogen sulfide concentration of 0.6% for 80 hours. The artificial sweat test was based on JIS L 0848A-
It was carried out in accordance with Act 1.

The outer gJi evaluation was performed by observing the gloss and discoloration on the surface of the polyethylene terephthalate film. Appearance evaluation was performed using the following five-step evaluation method.

Evaluation value 5 Very good 4 Good Good 3 Somewhat good 2 Slightly poor l Bad Good The results are shown in Table 1.

[Effects of the Invention] As is clear from the results of the sulfurization test and the artificial sweat test on the synthetic resin mirrors obtained in Examples 1 to 3 and Comparative Example 1, the synthetic resin mirrors of the present invention have extremely good performance. We have succeeded in providing a synthetic resin mirror with excellent properties such as sulfur resistance, chemical resistance, and sweat resistance.

Table 1

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view showing the basic structure of the synthetic resin mirror of the present invention. 2 to 4 are partially enlarged sectional views showing other embodiments of the synthetic resin mirror of the present invention. (1): Transparent synthetic resin plate or film (2): Undercoat layer (co): #! Reflective layer (4): Metal protective layer (5): Resin protective layer (6): Young agent (7): Back material

Claims (1)

[Scope of Claims] 1. A synthetic resin mirror in which a silver reflective layer is formed by vacuum evaporation directly or via an undercoat layer on the back surface of a transparent synthetic resin plate or film, in which at least one or two layers are formed on the surface of the silver reflective layer. 1. A synthetic resin mirror characterized by being provided with a metal protective layer formed by vacuum evaporation of more than one layer. 2. The synthetic resin mirror according to claim 1, further comprising a resin protective layer provided on the surface of the metal protective layer. 3. The synthetic resin mirror according to claims 1 and 2, wherein a backing material is provided on the metal protective surface or the resin protective layer surface via an adhesive. 4. The synthetic resin mirror according to claims 1, 2 and 3, wherein the metal protective layer has a thickness of 35 nm or more.