JPH0749017B2 - Improved mirror - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved mirror having particularly excellent acid resistance, alkali resistance and ammonia resistance, as well as excellent workability such as cutting and chamfering.

[0002]

2. Description of the Related Art Conventionally, in a mirror formed by plating a silver mirror surface film on the back surface of a glass substrate, in order to prevent discoloration or peeling of the silver mirror surface film due to water vapor, various corrosion resistant gases, various chemicals or the like, or mechanical damage, It has been practiced to form a copper protective film on a silver mirror surface film, and then apply an alkyd resin paint containing Komeitan, Benji, lead cyanamide, calcium carbonate, etc., to form a backing paint film. .

However, the mirrors coated with a backing coating as described above have their respective effects, but sufficiently satisfactory performance can be obtained even in a bad environment existing under all conditions of use of the mirrors. There wasn't.

From the above points, the inventors of the present invention have further improved corrosion resistance,
In order to improve durability, we tried to use an epoxy resin paint as a backing coating film. Epoxy resin itself is generally excellent in corrosion resistance and durability for the backing coating film using epoxy resin paint, and also has high adhesiveness with a metal protective film such as copper, which is sufficiently higher than conventional mirrors. Although good durability and durability are obtained, another problem has been found in the processing of the mirror.

That is, when using a mirror, when cutting a large plate size mirror shipped from a factory into a predetermined size,
Or when chamfering the cut end surface of the mirror cut into a predetermined shape, the cut portion, or the backing coating film of the chamfered portion,
Or the silver mirror surface film, or these peel off at the same time,
A problem has been found that corrosion resistance and durability are reduced. Alternatively, it has also been found that when a large-sized mirror is cut into a predetermined size, the separation is poor and the cutting workability is reduced.

On the other hand, in order to improve the above processability, a coating using an epoxy ester resin obtained by esterifying an epoxy resin with a fatty acid as a vehicle is used as a backing coating film. Although the workability is improved, there is a problem that the corrosion resistance of the epoxy resin, particularly the acid resistance, alkali resistance and ammonia resistance is extremely lowered.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of a mirror having a backing coating film using various conventional paints, and the epoxy resin coating film originally has corrosion resistance, An object of the present invention is to provide an improved mirror that maintains durability and adhesiveness, prevents peeling of the backing coating film of the mirror or the silver mirror surface film at the time of cutting or chamfering, and has good separability after cutting the mirror. To do.

[0008]

That is, the present invention provides a mirror in which a silver mirror surface film, a metal protective film and a backing coating film are sequentially formed on a glass substrate, wherein the backing coating film is a dibasic acid. Of the bisphenol type epoxy ester resin esterified with one or more of the above, and the vehicle (B) and the pigment (P) in a weight ratio of P
/B=0.5 to 4.2, an improved mirror which is a coating film formed from a coating composition, and further an improved mirror wherein the dibasic acid is an aliphatic dibasic acid.

The present invention will be described in detail below. First, the present invention will be described with reference to the drawings. FIG. 1 shows a specific example of a mirror according to the present invention, in which 1 is a glass substrate, 2 is a silver mirror surface film formed on the glass substrate, and 3 is a silver mirror surface film. The metal protective film 2 formed on the silver mirror surface to enhance the chemical durability of 2 protects the silver mirror surface film and the metal protective film, and is formed on the metal protective film to further improve the corrosion resistance and durability. The backing coating which was made is shown.

In the above-mentioned mirror, as the silver mirror surface film,
A film formed by depositing a film on the surface of a glass substrate by an electroless plating method is usually used, but it is not necessarily limited to this, and it is formed by a vacuum deposition method, a sputtering method, or various other film forming methods. The formed silver film can also be used as a mirror surface film. The silver mirror surface film has an appropriate film thickness of 0.5 to ² g / m ² so that the reflectance required for a mirror can be sufficiently obtained and a silver mirror surface film having excellent durability can be obtained.

Further, the metal protective film is formed as a protective film for enhancing the chemical durability of the silver mirror surface film, which is likely to be chemically deteriorated, and has good adhesion to the silver mirror surface film and high chemical stability. A metal, more preferably a metal that can be easily formed by a film forming method similar to the silver mirror surface film, for example, an electroless plating method is selected. A typical metal protective film is a copper protective film, and other metal protective films such as copper alloy, nickel, nickel alloy, tin and tin alloy can also be used.

The metal protective film may be a single layer or two or more layers in which different kinds of metals are combined. It is appropriate that the metal protective film has a thickness of about 0.1 to 1 g / m ² so that a sufficient effect of improving chemical durability can be obtained and the adhesiveness with the silver mirror surface film is not impaired. is there.

A typical method for producing a mirror having a silver mirror surface film and a metal protective film is to prepare a glass plate having a smooth surface and no surface defects, thoroughly wash the glass plate, and then remove the silver mirror surface film. The surface on which is formed is activated, and an electroless plating method is applied to the surface, for example, a silver plating solution that deposits silver by a so-called silver mirror reaction is sprayed to form a silver mirror surface film, and then the electroless plating method is performed on the silver mirror film. Cu, Ni, Sn
Examples of the method include spraying a metal plating solution for depositing a metal such as the above or an alloy thereof to form a metal protective film, followed by washing and drying, but it can also be manufactured by various other methods.

In the present invention, in order to enhance the corrosion resistance and mechanical durability of the silver mirror surface film and the metal protective film on the above metal protective film, the following coating materials are applied and cured to form a backing coating film. To be done.

The coating composition used for the backing coating film of the present invention contains a vehicle whose main component is a bisphenol type epoxy ester resin esterified with one or more dibasic acids. The composition has a vehicle (B) and a pigment (P) in a weight ratio of P / B = 0.5 to 4.2.

Examples of the dibasic acid include isophthalic acid, terephthalic acid, orthophthalic acid, 2,6-diphthalenedicarboxylic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, hexahydroterephthalic acid, Methyl hexahydrophthalic acid, maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid,
Examples thereof include adipic acid, azelaic acid, sebacic acid, dimer acid and the like, and these are used alone or as a mixture of two or more kinds.

In the present invention, the use of an aliphatic dibasic acid is preferred, and adipic acid is most preferred.

The bisphenol type epoxy resin has, for example, an epoxy equivalent of 850 to 5000,
Epicron 40 having a number average molecular weight of 1400 to 6000
50, Epicron 4055, Epicron 7050, Epicron 9055 [trade name of Dainippon Ink and Chemicals, Inc.], Epicoat 1004, Epicoat 1007, Epicoat 1009, Epicoat 1010 [trade name of Yuka Shell Epoxy Co., Ltd.] and the like are preferably used. It These can be used alone or as a mixture of two or more.

The bisphenol type epoxy ester resin used for the backing coating film of the present invention is preferably prepared by mixing 1 to 20 parts by weight of a dibasic acid with 100 parts by weight of the bisphenol type epoxy resin to prepare a catalyst. After adding the required amount, 120 ~ 200 ℃, preferably 130 ~ 180 ℃
Can be obtained by heating in the presence or absence of a solvent.

Further, the coating composition used in the present invention includes talc, barium sulfate, mica, calcium carbonate,
Extending pigments such as barite powder; coloring pigments such as titanium oxide, zinc oxide, rouge, yellow lead, chromium oxide, iron oxide, ultramarine blue, phthalocyanine blue, carbon black and iron black; calcium leadate, basic lead chromate, Lead, cyanamide lead,
Use pigments that are usually used in paints, such as lead white and lead sulfate, and other rust preventive pigments.

In the coating composition of the present invention, the bisphenol type epoxy ester resin (B) as a vehicle and the pigment (P) are in a weight ratio of P / B =
It is necessary to fall within the range of 0.5 to 4.2. P / B
If less than 0.5, blisters are likely to occur in the coating film in the water resistance test, and the heat resistance also decreases. Also, P /
When B exceeds 4.2, the acid resistance of the coating film is reduced and rust is easily generated, which is not preferable.

In the present invention, in order to further improve the salt spray resistance and the acid resistance of the coating film, it is preferable to contain 5% by weight or more of the rust preventive pigment in the total solid content of the coating film.

Further, the vehicle of the coating composition of the present invention includes polyester resin, alkyd resin, acrylic resin,
One type or two or more types of styrene resin, vinyl resin, ketone resin, rosin, polyvinyl butyral resin, epoxy resin other than the above can be used in combination. Particularly preferred is a resin selected from alkyd resins, vinyl resins, styrene resins, ketone resins, rosins, or petroleum resins.

These resins are used in a proportion of 1 to 50 parts by weight with respect to 100 parts by weight of the bisphenol type epoxy ester resin. By adding these resins, it is possible to improve workability and the like during processing of the mirror.

If these resins are used in an amount of more than 50 parts by weight with respect to 100 parts by weight of the bisphenol type epoxy ester resin, it becomes difficult to achieve the object of the present invention, which is not preferable.

In the present invention, when calculating the P / B, the vehicle (B) is the total of the bisphenol type epoxy ester resin and other resins.

The coating composition used for the backing coating film of the present invention is a composition in which the above-mentioned bisphenol type epoxy ester resin and a pigment are combined to sufficiently achieve the object of the present invention. If necessary, an amino resin, a polyisocyanate, a blocked isocyanate, a polyamide resin or the like which is generally used for paints can be added as a curing agent component. By using a curing agent together, the chemical resistance of the backing coating film can be improved.

These hardener components are added in a proportion of 1 to 20 parts by weight with respect to 100 parts by weight of the bisphenol type epoxy ester resin or a mixture of the bisphenol type epoxy ester resin and the other resin, as a mixture of one kind or two or more kinds. To be done. When the amount added exceeds 20 parts by weight, it becomes difficult to achieve the object of the present invention, which is not preferable.

Also, as a matter of course, when calculating P / B in the present invention, the curing agent component is also included in the vehicle.

Further, in the coating composition used in the present invention, reinforcing agents such as glass fiber, glass flakes, mica, asbestos and synthetic silica, other thickeners, rust preventives, suspending agents, accelerating agents may be added, if necessary. Additives and the like that are generally used in paints can be added.

Further, as a matter of course, in order to dissolve or disperse the resin, an aromatic hydrocarbon type, an aliphatic hydrocarbon type, an ester type, an ether type, a ketone type,
A known solvent such as an alcohol-based solvent can be used in a necessary amount.

The coating composition thus obtained is applied to the back surface of the mirror by a method such as a brush, roller, spray or flow coater so that the dry film thickness is about 30 to 100 μm. Then, it is heated and dried at room temperature or at about 250 ° C. or lower to finish.

The backing coating film of the present invention prevents the silver mirror surface film, the backing coating film, or these from peeling off simultaneously at the time of cutting or chamfering, or has a good separability at the time of cutting. , Its adhesive strength is 5-13kg / c
m ² range, elongation rate 0.05 to 0.5%, stress 1.
0 to 2.5 kg / mm ² , elastic modulus is 500 to 1000 k
The optimum range is g / mm ² . Next, examples of the present invention will be described.

[0034]

【Example】

 [Synthesis of epoxy ester resin]

[Synthesis Example 1] Epichron 4050 was placed in a reaction vessel equipped with a heating device, a stirrer, a thermometer and a water separator.
[Dainippon Ink and Chemicals, Inc. product name: epoxy equivalent 900 to 1000] 950 parts by weight, succinic acid 50 parts by weight, and xylene 430 parts by weight were charged and heated in the presence of an inert gas.

Stirring was started when the raw materials were melted and stirring became possible, 25 parts by weight of 2-methylimidazole was added, and the temperature was raised to 140 ° C. The reaction was continued at the same temperature for 5 hours, and when the acid value reached 5, the reaction was terminated and cooled. After cooling, 800 parts by weight of propylene glycol monomethyl ether was added to give a bisphenol type epoxy ester resin solution (EE- having a nonvolatile content of 45% by weight and a viscosity of W).
1) was obtained.

[Synthesis Examples 2 to 7] Using the raw materials shown in Table 1, a bisphenol type epoxy ester resin solution (EE-2 to
EE-7) was obtained.

[0038]

[Table 1]

In Table 1, Epicoat 1007 is a trade name manufactured by Yuka Shell Epoxy Co., Ltd., and has an epoxy equivalent of 1750 to 2100. Further, in Table 1, Epiclon 9055 is a trade name of Dainippon Ink and Chemicals, Inc., and has an epoxy equivalent of 2400 to 3100.

Example A silver plating solution of a solution containing silver nitrate for depositing silver by a silver mirror reaction and a reducing solution for reducing silver was prepared on a sufficiently washed glass substrate (size: 72 mm × 36 mm × 5 mm). After spraying to form a silver mirror surface film having a thickness of 1 g / m ² and washing the film surface with water, a copper plating solution of a solution containing copper sulfate for depositing copper by an electroless plating method and a reducing solution for reducing copper is applied. Spray, 0.30
A metal protective film made of copper having a thickness of g / m ² was formed, then washed with water and dried.

Coating compositions of various formulations shown in Tables 2 and 3 (numerical values in the table indicate parts by weight) on the copper protective film of the glass plate on which the silver mirror film and the copper protective film were formed (implementation) Each of Examples 1 to 9 and Comparative Examples 1 and 2) was applied by a flow coater method so as to have a dry film thickness of 30 μm, and baked at a glass plate temperature of 80 ° C. for 5 minutes to form a dry film of 35 μm. Various test pieces were obtained by baking at a glass plate temperature of 135 ° C. for 5 minutes. The results of various performance tests performed on these various test pieces are shown in Tables 4 and 5.

[0042]

[Table 2]

[0043]

[Table 3]

In Tables 2 and 3, as the epoxy resin, Epicoat ^# 1001 [trade name, manufactured by Yuka Shell Epoxy Co., Ltd .: epoxy equivalent 450 to 500] is used, and as the alkyd resin, Arachid 5301X-50.
[Arakawa Chemical Co., Ltd. product name: Middle oil alkyd resin:
Nonvolatile content 50 wt%] was used for each. Also, Table 2
In Table 3, as the polyamide resin, Sunmide ^# 270 [trade name of Sanwa Chemical Industry Co., Ltd .: amine value 158: nonvolatile content 70% by weight], and as the melamine resin: Melan ^# 2000 [Hitachi Chemical Co., Ltd. Product name: n-Butanol modified melamine resin: Nonvolatile 5
0 wt%] was used for each.

[0045]

[Table 4]

[0046]

[Table 5]

In Tables 4 and 5, those not specifically mentioned in the table indicate passing or failing under the conditions defined in the following test methods. The performance test methods in Tables 4 and 5 are as follows.

[1. Cross-cut test] JIS K 5400
6.15, and the judgment is 10 points. [2. Immersion in warm water] When immersed in pure water at 60 ° C for 240 hours and taken out, no abnormality is observed on the silver surface. [3. Steam test] When exposed to steam at 60 ° C for 240 hours and taken out, no abnormality is observed on the silver surface.

[4. Hydrogen sulfide gas test] Exposure to 20 ° C. for 48 hours in a desiccator saturated with hydrogen sulfide gas,
When taking it out, do not find any abnormality on the silver surface. [5. Hydrochloric acid immersion] 2 in 1.5 wt% hydrochloric acid (first-grade reagent) water
No abnormality should be observed on the silver surface when immersed in 0 ° C for 72 hours and taken out. However, the four sides of the test piece were sealed.

[6. Immersion in caustic soda] 4 wt%, caustic soda (first grade reagent) was immersed in water at 20 ° C. for 96 hours and taken out, and no abnormality was observed on the silver surface. [7. Ammonia water immersion] Ammonia water (reagent first grade) 5
Mixture of 0 parts by weight and 50 parts by weight of pure water at 20 ° C and 96
No abnormality should be observed on the silver surface after immersion for a period of time and removal.

[8. Formalin Solution Immersion] No abnormality is observed on the silver surface when immersed in formalin (reagent grade 1) at 20 ° C. for 312 hours and taken out. [9. Immersion of bleach] When the product is soaked in "Kitchen Bright", a product of Lion Corp., at 20 ° C for 96 hours, no abnormality is observed on the silver surface. However, the four sides of the test piece were sealed.

[10. Immersion in Detergent] No abnormality is observed on the silver surface when immersed in "Sunpol" (Patent No. 1249719) manufactured by Sunpol Co., Ltd. at 20 ° C for 48 hours and taken out. However, the four sides of the test piece were sealed. [11. Salt Spray Test] No abnormality is observed on the silver surface when a salt spray test according to JIS Z 2371 is performed for 360 hours.

[12. Accelerated weathering test] JIS K 540
No abnormalities were observed on the silver surface when the accelerated weathering test according to 0.6.17 was carried out for 240 hours, and the coating film had wrinkles, blisters, cracks,
There is no peeling and the degree of chalking is small. [13. Cut-off test] 24 ″ × 18 ″ with cross cutting machine
(Thickness 5mm) When dividing a test piece into 12 ″ × 9 ″ into 4 pieces, after inserting the cutting line, place the nail lifting branch under the cutting line, fold the pressing plate from above, raise the nail lifting branch as it is, and lift it away. Is 30m
m or less was passed.

[14. Chamfering test] After heating at 120 ° C. for 1 hour, chamfering is performed at a back chamfering width of 3 mm and a speed of 25 mm / min to determine whether or not the edge portion is peeled. [No peeling at all: Pass (◎), Very partial peeling: Pass (○), Very peeling: Fail (x)] [15. Boiling water immersion] Immerse in pure water 100 ° C for 18 hours and take out When you do, do not find any abnormality on the silver surface.

[0055]

The mirror according to the present invention has good adhesion to a metal protective film, and also has water vapor resistance, water resistance, ammonia resistance,
Excellent chemical durability such as alkali resistance, acid resistance, formalin resistance, hydrogen sulfide resistance, etc., as well as adhesive strength, breaking strength,
It has a backing coating film with excellent mechanical properties such as impact resistance, and since the epoxy resin is esterified with a dibasic acid, the coating film has appropriate flexibility, elasticity, and stretchability. Since the releasability is imparted, the hardness of the backing coating film, the extreme adhesion with the metal protective film, the residual stress, the coefficient of thermal expansion, etc. are adjusted, so when cutting the mirror or when chamfering, the cut part, Alternatively, the backing coating film of the chamfered portion, the metal protective film, or the silver mirror surface film does not peel off, the separability after cutting the mirror is good, and the mechanical damage is small.

As described above, according to the present invention, a mirror having excellent corrosion resistance, durability and workability can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a mirror according to a specific example of the present invention.

[Explanation of symbols]

 1 glass substrate 2 silver mirror surface film 3 metal protective film 4 backing coating film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takanari Suzuki 8-15 Asahi-cho, Nishinasuno-machi, Nasu-gun, Tochigi Prefecture Fuji Heim 103 No. 103 (72) Inventor Takeshi Ito 35-5 Takayanagi, Nishinasuno-cho, Nasu-gun, Tochigi Prefecture

Claims (5)

[Claims] 1. A silver mirror surface film, a metal protective film, and
In a mirror in which a backing coating film is sequentially formed, the backing coating film contains a vehicle whose main component is a bisphenol type epoxy ester resin esterified with one or more dibasic acids, and An improved mirror which is a coating formed from a coating composition in which vehicle (B) and pigment (P) are in a weight ratio of P / B = 0.5-4.2. 2. The improved mirror of claim 1 wherein said dibasic acid is an aliphatic dibasic acid. 3. The improved mirror of claim 2 wherein said aliphatic dibasic acid is adipic acid. 4. The vehicle is a bisphenol type epoxy.
100 parts by weight of a solid content of cis- ester resin or 100 parts by weight of a solid content of bisphenol type epoxy ester resin, and one or more resins selected from the group consisting of alkyd resin, vinyl resin, styrene resin, ketone resin, rosin, and petroleum resin. An improved mirror according to any one of claims 1 to 3 comprising 1 to 50 parts by weight of solids. Wherein said vehicle, with respect to 100 parts by weight of the mixture solids in the bisphenol epoxy ester resin solids 100 parts by weight or Bisufe <br/> Nord epoxy ester resins and other resins, amino resins, The solid content of at least one curing agent selected from the group consisting of polyisocyanate, blocked isocyanate, and polyamide is 1-2.
The improved mirror of any one of claims 1 to 4 containing 0 parts by weight. [Necessity of proof] Required