JP2885894B2 - Phosphor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface-treated phosphor used for a color cathode ray tube, and more particularly, to a phosphor used for forming a phosphor film by a slurry coating method.

(Prior Art) In general, when a fluorescent film is formed on a cathode ray tube, a phosphor is dispersed in an aqueous solution containing polyvinyl alcohol (PVA), a chromate (for example, ammonium bichromate) and a surfactant, and the photosensitive material is dispersed. The resin slurry is applied to a glass panel. Next, ultraviolet rays are irradiated through a shadow mask to cure the PVA in the irradiated portion, and then the uncured portion of the fluorescent film is removed by development to form a desired stripe or dot layer. This operation is repeated three times to form green, blue, and red fluorescent films. If a part of the predetermined pattern is lost or the particle layer is dropped during the formation of the fluorescent film, the fluorescent film is defective. Thus, the adhesive strength of the fluorescent film is a very important issue in terms of both performance and productivity. For this reason, many surface treatment methods for improving the adhesive strength by attaching silicon oxide, zinc hydroxide, or the like to the phosphor surface have been studied. (Special Publication 61-
(Refer to Japanese Patent No. 46512) (Problem to be Solved by the Invention) However, recently, with the development of a high-definition tube, the demand for reducing the pattern diameter has increased, and the quality required for the fluorescent film has been increasingly sophisticated. In fact, an adhesive force corresponding to the above is not obtained.

An object of the present invention is to solve the above-mentioned problems and to provide a phosphor having an excellent adhesion and capable of efficiently forming a high-definition pattern.

(Means for Solving the Problems) The present invention has a wavelength of 300 to 450 nm, which is suitable for absorbing light from a high-pressure mercury lamp as a light source for exposing a photosensitive resin for forming a fluorescent film and exposing the photosensitive resin. An organic compound having a maximum absorption wavelength between the phosphor particles, wherein the organic compound has a molecular absorption coefficient at the maximum absorption wavelength of 3000 l / molcm or more as the organic compound. It is preferred to use The above organic compound is
It is effective in absorbing the light of the high-pressure mercury lamp for exposure as much as possible, increasing the degree of curing of the photosensitive resin, and increasing the adhesive strength of the phosphor. As the organic compound, for example, one or more compounds selected from a salicylic acid ester type, a benzophenone type, a benzotriazole type, a cyanoacrylate type, a nickel complex salt type, and a diazo type can be used. Sumithorp 100 (Sumitomo Chemical:
Effective absorption wavelength 280-340 nm) and Uvinul D-50 (manufactured by BASF:
Maximum absorption wavelength 340nm, effective absorption wavelength 280-340nm), Tinuvin 234 of benzotriazole type (GEIGY: maximum absorption wavelength)
346nm) and Tinuvin 328 (GEIGY: maximum absorption wavelength 346n)
m), nickel complex salt type Cyasorb UV-1084 (made by ACC: effective absorption wavelength 270 to 330 nm), salicylic acid ester type OPS (E
astman: effective absorption wavelength 290 to 330 nm, Uvinul N35 based on cyanoacrylate (BASF: effective absorption wavelength 270 to 350 n)
m), diazo-based Diamonds Yellow 5R-E (Mitsubishi Kasei: maximum absorption wavelength 387 nm) and the like.

If the amount of the organic compound adhered is too large, it interferes with the phosphor sieve. Therefore, the amount is usually 12% by weight or less, preferably 0.01 to 5% by weight, particularly preferably 0.1 to 5% by weight based on the phosphor.
05 to 1% by weight.

The phosphor of the present invention can be generally applied to a phosphor used for a color cathode ray tube, for example, a zinc sulfide-based phosphor, a europium-activated yttrium oxide phosphor, an oolopium-activated yttrium oxysulfide phosphor, and the like.

(Operation) When exposing a coating film made of a photosensitive resin slurry in which a phosphor is suspended, light from an exposure light source passes through a shadow mask and reaches the coating film. As shown in Fig. 2, it has a trapezoidal shape, the central part is called a true shadow part, and the peripheral part is called a penumbra part. The exposure amount of the penumbra part gradually decreases toward the outside, and the photosensitivity increases in proportion to the exposure amount. The degree of cure of the resin, ie, the adhesive strength, also decreases. Therefore, in the present invention, by adhering the organic compound to the surface of the phosphor particles, the light of the high-pressure mercury lamp as the exposure light source, in particular, the light in the penumbra portion, which has a relatively small amount of light compared to the shadow portion, is emitted. While absorbing as much as possible,
The hardening of the photosensitive resin in the shadow area was promoted, and as a result, the adhesion of the phosphor was enhanced, so that the edge of the pattern could be finished finely.

In order to evaluate the adhesive strength, the thickness of the fluorescent film is made constant, the pattern is cut while changing the amount of exposure, and the minimum pattern diameter is measured. That is, the pattern diameter at the minimum exposure amount at which a pattern can be formed is called an adhesive force, and the smaller the value is, the stronger the adhesive force is evaluated as shown in FIG.

 Hereinafter, examples of the present invention will be described.

(Example 1) When the chemical composition is 2- [hydroxy-3,5-bis (α,
α'-dimethylbenzyl) phenyl] -2H-benzotriazole, Tinuvin 234 (manufactured by Ciba Geigy) 0.3 g
Was dissolved in 40 g of acetone, and this acetone solution and 120 g of a blue light-emitting phosphor without pigment (referred to as phosphor A) were stirred and mixed at room temperature for 60 minutes. Thereafter, substantially all of the acetone was evaporated by heating and passed through a 500-mesh sieve to obtain a phosphor to which the organic compound was attached (referred to as phosphor B, the attachment amount was 0.25% by weight). Almost no unsieved product remained on the sieve. Using this phosphor B, a phosphor film was formed on a cathode ray tube, and the adhesive strength was evaluated. The results are shown in Table 1.

(Example 2) A phosphor to which the above organic compound is attached in the same manner as in Example 1 using a blue light-emitting phosphor with a blue pigment (referred to as phosphor C) instead of phosphor A in Example 1 ( Phosphor D) was manufactured, and the adhesion was evaluated. Table 1 shows the results.

(Example 3) 10 g of Tinuvin 234 (manufactured by Ciba-Geigy) in acetone at 50 ° C
This acetone solution and 100 g of the phosphor A used in Example 1 were stirred and mixed at 50 ° C. for 60 minutes. Thereafter, substantially all of the acetone is evaporated by heating to 50
Phosphor which adheres the above organic compound by passing through a 0-mesh sieve (referred to as phosphor E, adhesion amount is 9% by weight)
I got On the sieve, 3 g of the phosphor having poor sieve properties remained. Using this phosphor E, a phosphor film was formed on a cathode ray tube, and the adhesive strength was evaluated. The results are shown in Table 1. It should be noted that the density and uniformity of this fluorescent film were slightly lower than those of the other examples.

(Comparative Examples 1 and 2) Using phosphors A and C to which the organic compound was not attached,
The adhesive strength was evaluated. Table 1 shows the results.

(Comparative Example 3) Benzoiophenone-based Uvinul was added to an aqueous solution containing polyvinyl alcohol, ammonium bichromate, and a surfactant.
0.25 g of MS40 (manufactured by BASF) is added to 100 g of the phosphor,
Mixed. The adhesive strength was evaluated using a slurry in which phosphor A was dispersed in this aqueous solution. Table 1 shows the results, but the effect of improving the adhesive strength was not observed even when the organic compound was added to the slurry.

(Effects of the Invention) The present invention, by adopting the above configuration, can increase the adhesive force without disturbing the phosphor sieve, and can efficiently form a finer pattern. It greatly contributes to the production of high definition tubes.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the exposure amount and the pattern diameter, and FIG. 2 is an explanatory diagram of the exposure amount distribution.

Continuing on the front page (72) Inventor Shusaku Kakita 1060 Narita, Odawara City, Kanagawa Prefecture Inside Kasei Optonics Co., Ltd. (72) Inventor Shigeki Shimizu 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Chemical Research Institute (56) References JP-A-57-105947 (JP, A) (58) Fields investigated (Int. . ^6, DB name) C09K 11/00 - 11/89

Claims (2)

(57) [Claims] 1. An organic material having a maximum absorption wavelength between 300 and 450 nm, which absorbs light from a high-pressure mercury lamp, which is a light source for exposing a photosensitive resin for forming a fluorescent film, and is suitable for exposing the photosensitive resin. A phosphor, wherein the compound is attached to phosphor particle surfaces. 2. The phosphor according to claim 1, wherein the organic compound has a molecular extinction coefficient of 3000 l / mol · cm or more at the maximum absorption wavelength.