JPS5918767A - Aqueous coating material composition of fluorescent substance - Google Patents

Abstract

PURPOSE:The titled composition, consisting of a water-soluble binder, a fluorescent substance, B2O3, etc., Sr(NO3)2, etc. and a low-melting water-resistance glass powder, capable of preventing the formation of pinholes due to the falling off of the fluorescent substance, and having improved adhesive strength to glass tubes for fluorescent lamps. CONSTITUTION:A composition obtained by adding (B) a fluorescent substance, (C) B2O3 and/or H3BO3, (D) Sr(NO3)2 and/or Ba(NO3)2 and (E) a low-melting water-resistant glass powder in adequate amounts to (A) a water-soluble binder, e.g. polyethylene oxide. One of the components of each (C), (D) and (E) is used in 0.05-5.0wt%, 0.05-2.0wt%, and 0.1-10wt% respectively, basing on the amt. of the fluorescent substance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in phosphor aqueous coating compositions, and in particular,
This invention relates to improving the adhesion strength of a phosphor film to a glass tube.

Conventionally, when applying a phosphor film to the inner surface of a glass tube for a fluorescent lamp, for example, the phosphor and low melting point glass powder are mixed in a solution dissolved in butyl nitrocellulose trh, which is a binder, and the phosphor film is mixed with τ glass. Coating on the inner surface of the tube, drying, and firing process? Over time, a fluorescent film was formed. If such a coating composition does not contain gold as an adhesive such as a low-melting point glass powder, the fluorescent film will not adhere firmly to the glass tube, and only peeling will result. especially,
In the case of current fluorescent lamps, the fluorescent light RL tends to peel off during the process of forming the glass tube into a metal shape.

The use of organic solvents such as butyl acetate in such coating compositions is not preferable from the viewpoints of flammability, toxicity to the human body, and economic efficiency.

However, when a water-soluble binder solution is used, the above-mentioned low-melting point glass powder dissolves or decomposes in water, which adversely affects lamp characteristics when used in a fluorescent lamp. As a low melting point glass powder, one from Tanemaki has been proposed, but for example, CaO-Bao, which is commonly used in KJli.
-B2O3-based glass powder decomposes in water and cannot be used.

The present inventors have discovered a glass with a new composition that hardly decomposes or dissolves in water, and furthermore, contains Sr (NO3).
A phosphor aqueous coating composition comprising at least one of z and B a (NOa) 2 was developed.

However, when the aqueous binder is polyethylene oxide, the phosphor +
1-'f- may peel off at a diameter of 1 nvn or less (hereinafter referred to as a pinhole), which impairs the appearance of the fluorescent lamp. The cause of this is not clear, but it tends to occur when it is mixed with a phosphor having a small particle size, such as a Mn-activated zinc silicate phosphor or a calcium halophosphate phosphor.

In addition, this phenomenon is likely to occur even when using a calcium halophosphate phosphor having a relatively small specific gravity. For this reason, countermeasures have been desired.

Therefore, an object of the present invention is to provide a phosphor water-based coating composition that can prevent pinholes from occurring due to phosphor falling off.

Therefore, the phosphor aqueous coating composition of the present invention contains a phosphor, at least one of B203 and HsBOs, 5
at least one of r(NO3)z and Ba(NOx)i
The water-soluble binder solution contains appropriate amounts of both the powder and the low-melting-point water-resistant glass powder.

IJ203 or 113 BO3'l: The reason for using the phosphor in the aqueous paint is to dissolve m11 in the baking process and improve the adhesion strength of the phosphor film to the glass tube.

As a result, it was confirmed that the number of pinholes generated was extremely reduced, and that there was no shadow of 2 mi on the lamp luminous flux.

The present invention will be explained in detail below.

Polyethylene oxide 0.8% dissolved IL 160c
Water-resistant glass powder with a low melting point (composition of glass powder Laz
(J3:MgO:Li2O:Bz03=l O: 37
: 3:50 mol% L: 4g was added, and after pulverizing with a ball mill, [1203, phosphor, for example, Mn-activated zinc silicate phosphor? 100 g and S
(NOs) 2 was added in the amount listed in Table 1, and further mixed for 30 minutes in a ball mill to form a phosphor paint. Manufacture. In addition, the amount added is % of the size of the lid that is inserted into the phosphor.
It is.

This paint'kJ! Coat the inner surface of a 30cm glass tube for fluorescent lamps, and blow heated air at about 60 to 70r into the entire glass to completely evaporate the moisture to form a phosphor. ! l-form.

After that, annular fluorescent lamps are manufactured using normal manufacturing methods. The number of pinholes formed after the lamp was completed is shown in Table 1.

As shown in Table 1, the number of pinholes tr'i B2
It can be seen that the addition of U3 caused a significant decrease, indicating a remarkable effect.

It was confirmed that similar effects could be obtained by using IsEOsk (instead of IJ20a) and by using Ba (NO312'x in place of 5r (NOsb).

In addition, 4i1f and 1-sparing studies revealed that B2O3 and 1 (at least 14T4 of 3Dos is 0.05-5.0% by weight relative to the phosphor, SrCNOs)
2 and IJ"(NO3)2 is the same o, os = 2% by weight, and the low melting point water-resistant glass powder is the same <0.1 to 10% by weight to form pinholes. It has been confirmed that this can be significantly reduced compared to conventional methods.

As described above, according to the present invention, the phosphor water-based paint composition in which the occurrence of pinholes is suppressed in the corners =439-

Claims (1)

[Scope of Claims] (1) A water-soluble binder, a phosphor, and at least 1 at and 5r (NO
A phosphor water-based coating composition comprising at least one of a) 2 and Ha(NOa)z and a low melting point water-resistant glass powder. 2. The phosphor water-based coating composition according to item 1, wherein the water-bathable binder is polyethylene oxide.