JPS60151249A - Composition for enamel film - Google Patents

Abstract

PURPOSE:To obtain a fluorescent enamel film having superior durability, water resistance, wear resistance, fouling resistance, light resistance, heat resistance and satisfactory afterflow characteristics by using glass having a low softening point and a specified composition when a film is composed of light accumulating ZnS, CaS or CdS and glass for enamel. CONSTITUTION:This composition for an enamel film contains 20-50wt% one or more among ZnS, CaS and CdS as inorg. crystalline phosphors each having a light accumulating property and 47-76wt% glass for enamel. This glass for enamel contains, by weight, 31-39% SiO2, 13-21% B2O3, 14-22% Na2O, 1-5% K2O, 13-20% ZnO, 2-10% F2 and <=5% one kind of oxide or 2-9% in total of two or more kinds of oxides selected among Al2O3, ZrO2 and TiO2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is useful for signs at night and in dark places, signs for railroad crossings and station passages, emergency exit signs, taillights for automobiles and other devices. The present invention relates to an enamel coating composition that is used by applying it to parts. It is still used as a luminescent enamel coating that is used for shadowless lighting that applies ultraviolet rays to ceilings and walls, and for display items such as advertisements.
durability.

i (Abrasion resistance, water resistance, stain resistance 2) It has excellent heat resistance, and has good afterglow characteristics of sweet fluorescent light, making it possible to display fluorescent light in the dark.

Structures of conventional examples and their problems Conventional fluorescent materials include fluorescent dyes such as rhodamino and eosin, and fluorescent pigments such as rhodamino tungstate, as organic substances. Dammar, chlorinated rubber, vinyl chloride resin, ivy acrylic acid resin,
A 41-film phosphor using alkyd resin face etc. is used.

These (are organic films, so they are susceptible to wear and contamination, and -
There was also the problem that the 1st tail Nanato was also inferior.

On the other hand, ZnS and CaS are used as inorganic phosphors.

There are fluorophores that do not exhibit afterglow of recrystallized types such as CdS, Bt, and Cu. The most commonly used of these is Z
This is an nS phosphor, and when it is made of ZnS as a matrix 7, added with Cu, Ag, etc. as an activator, mixed with a flux 1-, and fired, a phosphor with a remarkable afterglow is obtained. ZnS phosphors are cheap, harmless, and stable to hydrogen sulfide, but
It has problems such as poor durability, darkening when exposed to light, and deterioration/stiffness due to the influence of oxygen and moisture in the air.

In general use, ZnS is added to a resin and molded and used as a fluorescent plastic, or an organic resin is used as a vehicle and applied as a paint to signs and dials.

However, 7. This method is also used as a treatment coating, so
It is susceptible to wear and contamination (the problem is that the area around the ZnS is coated with resin, or that it passes through oxygen and moisture, causing deterioration).

Unfortunately, these organic coatings have poor heat resistance, and will almost always decompose or burn at temperatures above 300 degrees Celsius.

Therefore, there were several possible methods of using ceramic or glass as a vehicle for the ZnS phosphor, as described below.

(1) ZnS phosphors exhibit weak light emission due to the influence of impurities, and are particularly susceptible to the effects of Fe, Co, Ni, and the like.

(2) In ceramics and enamels that are fired and sintered at high temperatures of 800° C. or higher, the crystallinity of ZnS decreases/stiffens, reacts with the alkali components in the glass, and emit light becomes weak.

(3) There is PB glass with a low softening point, but it weakens the luminescence of ZnS and is a hygienic problem as a harmful substance.Other low softening point glasses also have a lot of alkaline components, so Reacts with Z, n S and the luminescence becomes weak or dark.

Furthermore, if you try to construct a enamel phosphor coating,
There are also problems with the softening point of glass, coefficient of thermal expansion, reactivity with ZnS, chemical properties of the coating, surface condition, toxicity, etc., and a porous coating 1t11 composition that satisfies these issues has not been obtained.

OBJECTS OF THE INVENTION The object of the present invention is to provide a fluorescent enamel coating composition that is excellent in durability, water resistance, abrasion resistance, 1lIi-1 staining, 1llIl luminosity, and 1lliI heat resistance, and has good afterglow properties. .

Structure of the Invention The present invention provides that at least one kind selected from the group consisting of ZnS, CaS, and CdS is added to the enamel coating as an inorganic crystal phosphor having a luminescent property in an amount of 20 to 50% by weight of the total amount of the enamel coating. (hereinafter simply expressed as ``part''), containing 47 to 76% of the total amount of Poro coating,
A low softening point glass having a specific composition C is used as the glass for the bowleau.

Description of examples Fluorescence refers to luminescence caused by light stimulation.

Luminescence that disappears as soon as the applied light is removed is called fluorescence, and when the emission continues it is called afterglow, and such substances are called phosphorescent substances.

Inorganic phosphors are mainly composed of oxides, sulfides, guates, phosphates, tungstates, etc. of Ca, Ba, Mg, Zn, Cd, etc., and 1 to 0.1% ( 7) Mn,A
Add activators such as g, Cu, Sb, and Pb, and
It is made by firing at ~1300C for several hours.

The phosphors used in the present invention (ZnS, CaS and Cd
It is a crystalline phosphor of S. As the source of fluorescence, electrons or holes are captured in traps, absorbing light energy, stored in the phosphor, and thermally released. Since it is emitted and emits light upon recombination, it is an image-coupled afterglow, and is particularly characterized by a long afterglow duration.

As an example, a method for manufacturing a ZnS phosphor will be described. 10 moles of Cu was added as a filler to 1 mole of ZnS, and 0.1 mole of KCl was added as a flux, heated to 1200°C in a quartz cup and held for 1 hour. 6. When Cu is used as an activator, the color is green, and Ag is 'i! I
', P)) shows paleogreen, Mn i4 orange luminescence.

A complete summary of the Zn5-Cu phosphor made in this way
'Jy * X is 0.21 in the color display of u, C, 1, E
-0.29゜y is in the range of 0.54 to 0.66, it shows green-yellow green, and the wavelength peak (ql: 61o-54o
In the nm range, the particle diameter is ξ4 (average 25 μ
It's). In order to increase the durability of this item, S i
02 is coated on the surface and it is 5.

Erasing is required as enamel frit. It is necessary to have a thermal expansion coefficient of 1A, fluidity, and softening point, and good adhesion when forming an enamel film, as well as good chemical, human, and surface conditions. In particular, the important factors required are:
The firing temperature is sometimes low, and it is usually
Since the luminescence of ZnS decreases significantly when fired at 20 to 860°C, it is first required that the glass has a low softening point.

Therefore, in the present invention, glass with a low softening point is used. .

The typical compositions of these glasses will be described.

The glass shown in Table 1 is lead-free borosilicate glass that is made of dust and fired at temperatures below 690°C, is transparent, does not oxidize the sulfide that is the fluorescent substance, and coats the surface with glass. Since it forms a protective film, it has excellent fluorescent afterglow properties.

In this glass composition, S102 is an essential component that forms the skeleton of glass, but in order to lower the softening point, it is necessary to reduce the amount of 8102. If SiC2 is less than 31,
As the solubility of the frit in hot water increases, the free alkali component increases and reacts with the ZnS of the phosphor, resulting in blackening. When the S value exceeds 102 or 39 inches, the softening point becomes high and cannot be fired at a temperature below 720°C, so the ZnS turns black due to thermal oxidation and the afterglow properties deteriorate. From these points 3
102 is suitably in the range of 31 to 39%.

The B2O3 component plays an important role in melting the glass, and is also important in improving the gloss and adhesion to the base metal after enamel firing. When B2O3 exceeds the 21st factor, the tendency to melt into hot water increases and ρ7 becomes difficult. Moreover, if it is less than 13, the gloss of the enamel film and the afterglow properties of the phosphor will deteriorate, making it unsuitable for H4. From these points, a suitable range for B2O3 is 13 to 21 inches.

The F2 component is an essential component to maintain the optimum acidity of glass6, and the alkaline component is Na2O.

There are K O and L i20, but by neutralizing them in glass and reducing free alkali components, Z
It works to improve the afterglow characteristics of nS.

If F2 is less than 2 coefficients, the effect of neutralizing alkaline components is poor [7], and if it exceeds 10 coefficients, bubbles will form on the enamel surface.
IHL appearance will be poor. From these points, a suitable range for F2 is between 2 and 10.

Na O, K O, L 120 have alkaline components,
2 2 It is a component that has a strong melting effect and lowers the softening point of glass, and is effective in the order of L120>Na2O>L20. However, when the alkali component increases, the solubility in hot water increases, and when the free alkali component increases, it reacts with the phosphor ZnS, resulting in blackening and deterioration of afterglow properties. From these, 14 to 22% of Na 20 and 1 to 5% of L20 are suitable, and 4% or less of LL 20 may be included.

Zn○ has the property of acting as a melting agent and improving the water resistance and chemical durability of the frit.
If it is less than 13, the solubility of the frit in hot water is large and unfavorable. When it exceeds 20%, the coefficient of thermal expansion increases,
This is not preferable as it tends to cause cracks on the enamel surface.

From these points, Zn◯ is preferably in the range of 13 to 20%.

81203 as an intermediate oxide component. TlO2, Z r
O2 is effective in improving the water resistance and acid resistance of the frit, and if it is not added, it increases the softening point by 1 and also reduces the gloss of the enamel. If the total amount of these intermediate oxides (Ae203 + TiO2 + Zr○2) is less than 2%, the water resistance will be low, and if it exceeds 9%, the softening point will rise, and 7%.
Cannot be fired at temperatures below 20°C. From these (Ae203+
For Ti○2+Zr02), the 2nd to 9th sections are H4. Mo
Regarding Os, H4 is recommended to have a ratio of 2 or less to improve adhesion.

The glass shown in Table 1 B is a lead-free borosilicate glass that has a firing temperature of 720°C or lower, is transparent, has low reactivity with the phosphor ZnS, and has an excellent residual l, showing the characteristics.

The SiO2 content of this (11%) is 32-45%, and if it is less than 32%, the hot water solubility of the frit will be too high, and if it exceeds 45%, the softening point will be too high, so it is not suitable. No. This glass is 1.L compared to the glass in A.
Since it contains a large amount of i2O, CaO, and BaO, the content of 5102 is high. From these points, 3102 is 32
~46 inches is preferred.

If the B2O3 component is not as high as 7, the acidic component will decrease and the free alkali component will increase, which is not preferable since ZnS is likely to be oxidized. If the size exceeds 20, dissolution in hot water w1: The helmet will become large, which is not preferable, and B203i-
, j near-20 range is suitable. The F2 component is an essential component for maintaining optimal acidity in the glass, and neutralizes the alkaline components Na2O and 20° Li2O in the glass to reduce the amount of free alkali components. F
If F2 is less than 2%, the effect of neutralizing the alkaline component is poor, and if it exceeds 9, bubbles are likely to be generated on the surface of the porous material. Therefore, the preferable range d for F2 is 2 to 9.

Na 20. 20. L 120 is an alkaline component and has a strong melting effect, and the order of the effect is '3, L i20:>Na 20) F20. 2. If the alkaline content increases, the solubility in hot water will increase, and the free alkaline content will also increase, which is undesirable as it will react with ZnS and reduce the afterglow properties. . From these, Na 20 is 14 to 22%, and 20
Preferably, it is 0.4% to 5%, and Ll20 is 0.3% to 2%.

CaO and BaO are alkaline earth metal oxides.
It has the effect of improving the fluidity of glass without increasing the weight of the glass, and the appropriate range for H4 is 1.5-16% for CaO and 1.6-15% for BaO.

ZnO has the effect of improving the water resistance and gloss of the frit, and may be contained in an amount of 5 or less.

ZrO2 and At203 have the effect of improving the chemical durability of glass, and Zr02 is 0.5 to 4.6%;
At203 has a desirable IE range of 0.5 to 6 ratios.

The above-mentioned glasses A and BI'i can be fired at temperatures below 720°C, and as they do not require high-temperature firing, oxidation of the phosphor can be suppressed, and can be used as a fluorescent porcelain coating. Afterglow special 1. Excellent. Furthermore, since the acidic and alkali components in the glass are neutralized and there is little free alkali component, it does not react with the phosphor and darken, and has good afterglow properties.

Pr, Table 1 glass C low softening point glass based on sulfuric acid, glass thickness is 8
This is glass for iron porcelain fired at 30°C.

Next, the phosphor having luminous properties, the glass and mill additives shown in Table 1 are mixed at a blending ratio of t> shown in Table 2,
The material was put into a ball mill and milled while adjusting the particle size so that the size of the rainbow 1-shaped material was 2 to 61.

Thickness of steel plate (SPP) for base drilling and enameling. , 6 mm was pickled in a 10% H2SO4 solution to form Ni5O4.
Electroless Ninogalumenogi was carried out in a 15F//- aqueous solution of 7H20 to produce a sample with a pickling wave meter of 300 mf/dm" and a nickel adhesion amount of 7 rq/dt71".

The milled/post-milled slip was spray applied to the substrate. The film thickness was adjusted to 200tiK after firing.

The firing temperature is 690℃ for glass A and 700℃ for glass B and C.
The glass was fired at 830°C for 5 minutes. Table 2 shows the surface condition, gloss, adhesion, and
Shows afterglow characteristics.

Below margin Table 1 Table 2 (Part 1) Table 2 (Part 2) The evaluation method for the enamel film is as follows.

The appearance of the enamel surface was visually observed, and if no citron skin, pinholes, or cracks were observed, they were marked with an ○ mark, and when they were observed, they were marked with an X mark.

Gloss is measured by shining light onto the test plate at an incident angle of 45° and a reflection angle of 45°, and the mark ○ indicates a reflectance of 8o.
-1-1 Δ mark indicates 80 to 601 × mark indicates 60 or less.

The adhesion of the enamel is evaluated using the adhesion tester of the American Enamel Association (PEI).If the value is 90% or more, it is marked with an ○, if it is between 70 and 90, it is marked with a Δ, and if it is 70 or less, it is marked with a Δ. Items are marked with an X.

The afterglow properties of the coating are stimulated with ultraviolet rays, and after the light is removed, the afterglow remains for 6 minutes or more.
The time of 6 minutes is indicated by Δ, and the time of 2 minutes or less is indicated by X.

In addition, those that can be used in the comprehensive evaluation of these results are marked with ○.
Those with some defects are indicated with a Δ mark, and those that are unusable are indicated with an X mark.

From the above results, the types of phosphor and nitrate f- and the content of each component can be considered as follows.

(1) Fluorescent material As a phosphor with a long afterglow time, it is mainly a recombinant type of ZnS activated with Cu and has excellent stability.In addition, Aq, Pb.

Those activated with Mn or the like are also effective when changing the luminescent color. 3 moles of ZnS and 2 moles of CdS, activated with A(J), CaS, etc. also rang as enamel phosphors with luminous properties.

As a result of changing the content rate in the total weight of the enamel coating of one firefly, as shown in Table 2, when the content rate is less than 20%, the afterglow properties are poor, and when it is 53% or more, the appearance as an enamel coating, Not only the gloss but also the adhesion deteriorates, which is not desirable. From these results, the content of phosphor is 20~
50% is appropriate.9° (2) Glass The types of glass are shown in Table 1, and A and B are glasses for transparent enamel with a low softening point and are lead-free and non-toxic glasses. C is lead-based glass with a low softening point, and D is ordinary glass for iron enamel.

As shown in Table 2, when the phosphor content is 32,
Glasses A and B have good enamel appearance and afterglow characteristics, or glass C (d has pinholes in appearance, ZnS darkens, and afterglow 141' is poor. 1,
The glass in D is fired at a high temperature of 820°C, so it is ZnS.
The afterglow characteristic of ← is significantly lower than that.

Glass A and B are better than this.

If the content of amada glass exceeds 76%, the afterglow will decrease.44
% or less, the ZnS cannot be coated in a soft manner, and the darkening and afterglow properties are also low, and the surface state of the enamel also becomes pinhole-like, resulting in poor adhesion. From these points, it is appropriate for the glass content to range from 47 to 76.

Next, the mill composition shown in Example 6 was milled using a ball mill to prepare a slip.

As a base material, 50 cm long, 26 nn wide, and 0.4 plate thick steel for enamel was pre-treated with sulfuric acid and N1
is attached by electroless plating, and the pickling loss is 300 my/d+
++' and a Ni adhesion amount rq/d m' were prepared. This was coated with the above-mentioned slip to a film thickness of 250 lt, dried, and baked at 690° C. for 6 minutes to produce a fluorescent plate. By using this board as a ceiling and wall and irradiating it with a black light that emits ultraviolet light, we were able to create bright, shadowless lighting. Since the ceiling and walls are made of enamel, they are resistant to wear and contamination, and can be easily cleaned if they get dirty. In addition, since the firing temperature is below the A1 transformation point, thermal distortion is small and 0.
Since it can be enamel-processed on a thin plate such as 4mm, it has features such as eaves eaves and shape.

Effects of the Invention As described in ``2'', the enamel coating composition of the present invention is a luminescent phosphor and can be fired as an enamel below the A1 transformation point of iron, so it has effects such as lightening and energy saving. Due to the low firing temperature, it has excellent afterglow properties, and the phosphor is covered with glass, making it highly durable, extremely abrasion resistant, stain resistant, heat resistant, and light resistant. ,
It has excellent durability and is water-based, and can be used outdoors and at night as a fluorescent sign.

Claims (2)

[Claims] (1) ZnS as an inorganic crystal phosphor with luminous properties
. An enamel coating composition containing 20 to 60% by weight of at least one selected from the group consisting of CaS and CdS and 47 to 76% by weight of enameled glass, wherein the enamel glass contains 31% by weight of Si02. ~39 Section, B2
O3 at 13-21%, Na 20 at 14-22%, K
2O 1-5%, Zn○ 13-20%, F2 2-5%
contains Al2O3, Z r 02 and T
1. An enamel coating composition comprising 5% or less of one type of intermediate oxide selected from the group consisting of 102, and a total amount in the range of 2 to 9%. (2) ZnS as an inorganic crystal phosphor with luminous properties
. An enamel coating composition containing 20 to 50% by weight of at least one selected from the group consisting of CaS and CdS and 47 to 76% by weight of enameled glass, wherein the enameled glass has a weight ratio of 8102 to 32 to 45%. %, B2O3
7220, F2 2-9, Na 20 14
-22%, K2O 0.4-6%, L 120 0.3
-2%, CaO 1.5-15%, BaO 1.6-1
6%, ZnO 5% or less, ZrO2 0.6-4.5%
, an enamel coating composition containing 0.5 to 6% of Aβ203.