JPH10312748A - Fixing method for phosphor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently fix phosphors on the side face and bottom face of a cell, efficiently increase luminance, and reduce the quantity of the phosphors used by superposing resin composition layers containing two phosphors having average grain sizes of a specific relation on each other in the cell of a plasma display panel respectively, the exposing, developing, and baking them. SOLUTION: A resin composition layer A containing phosphors having the average grain size of (a) μm is provided in a cell, a resin composition layer B containing phosphors having the average grain size of (b) μm larger than (a) μm is provided on it, and the relation of 1<b/a<=10 is preferably satisfied. A barrier rib substrate fixed with these phosphors has the luminance much higher than the luminance of the laminated layer of two layers B or the layers A, B containing opposite phosphors. A photosensitive resin layer containing no phosphor is preferably provided on the layer B, and the layers A, B contain a base polymer and an ethylene compound containing an ethylene unsaturated compound of total 100 pts.wt. and phosphors of 1-800 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a phosphor in a partition (cell) at the time of manufacturing a phosphor display device such as a plasma display panel (PDP).

[0002]

2. Description of the Related Art Recently, various flat panel display panels have been actively developed. Among them, PDPs have attracted attention. From now on, display screens of laptop personal computers will be used to display various electronic bulletin boards and so-called "wall-mounted". Its use is expanding to TV. A phosphor for display is sealed (fixed) in the cell of the display panel of the PDP, and the phosphor emits color by ultraviolet rays generated by the sealing gas in the cell due to an applied voltage. As a method of fixing such a phosphor, a liquid photoresist in which phosphors of each color are dispersed has been used, but in order to improve the fixing method, the present applicant has replaced such a liquid photoresist with Proposed a dry film resist (photoresist film) containing a phosphor (Japanese Patent Laid-Open No. 6-27)
No. 3925) and a pattern forming method using a laminate of an acrylic resin layer and a phosphor-containing photosensitive resin composition layer in order to improve the fixing efficiency of the phosphor (Japanese Patent Laid-Open No. 9-6933).
No. 9).

[0003]

However, with respect to the photoresist film described in JP-A-6-273925, sufficient study has been made on the filling properties of the phosphor into the partition walls (cells). Regarding the technology disclosed in Japanese Patent Application Laid-Open No. 9-69339 in consideration of this point, the filling amount of the phosphor into the partition can be ensured, but the phosphor is uniformly and efficiently placed on the side wall and the bottom of the partition (cell). There is still room for improvement in terms of fixing and efficiently obtaining luminance. That is, in order to make the phosphor filled in the partition wall (cell) emit light efficiently, it is desired to efficiently fix the phosphor on the side wall surface or the bottom surface of the partition wall (cell) as described above, and to obtain luminance efficiently. Rarely, if such fixation is realized, an economical secondary effect that the amount of phosphor used can be reduced can also be expected.

[0004]

The present inventor has conducted intensive studies in view of the above circumstances, and as a result, when fixing the phosphor in the partition wall (cell) of the plasma display panel, the present inventors have found that the partition wall (cell) does not have to be fixed. The resin composition layer (A) containing a phosphor having an average particle diameter of a (μm) and the resin composition containing a phosphor having an average particle diameter of b (μm) so as to satisfy the following expression (1). After the layer (B) is sequentially provided, exposure, development and baking are performed, so that the phosphor-containing layer (film) can efficiently fix the phosphor on the side walls and the bottom of the partition (cell). The inventors have found that good luminance can be obtained, and have completed the present invention. a <b (1)

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the method of the present invention will be described in detail.

[0006] The present invention phosphor used in body is not particularly limited, the rare earth oxyhalide such as a host, preferably those activated by an activator of the mother, for example, as an ultraviolet excitation type phosphor, Y ₂ O ₃ : Eu, YVO ₄ : Eu, (Y,
Gd) BO ₃ : Eu (more than red), BaAl ₁₂ O ₁₉ : M
n, Zn ₂ SiO ₄ : Mn, LaPO ₄ : Tb (green above), BaMgAl ₁₄ O ₂₃ : Eu, BaMgAl
₁₆ O ₂₇ : Eu (above blue) and the like, and other phosphors include Y ₂ O ₃ S: Eu, γ-Zn ₃ (PO ₄ ) ₂ :
Mn, (ZnCd) S: Ag + In ₂ O ₃ (all red),
ZnS: Cu, Al, ZnS: Au, Cu, Al, (Z
nCd) S: Cu, Al, Zn ₂ SiO ₄ : Mn, As,
Y ₃ Al ₅ O ₁₂ : Ce, Gd ₂ O ₂ S: Tb, Y ₃ Al
₅ O ₁₂ : Tb, ZnO: Zn (green), ZnS: A
g + red pigment, Y ₂ SiO ₃ : Ce (above blue) and the like can also be used.

In the present invention, the phosphor as described above is added to the layer (A).
And the layer (B), and the layers are sequentially laminated in the partition. In the present invention, in particular, the average particle diameter of each phosphor contained in the layer (A) and the layer (B) is specified. The biggest feature is that the relationship is established. That is, the average particle diameter a (μm) of the phosphor contained in the layer (A) and the average particle diameter b (μm) of the phosphor contained in the layer (B) must satisfy the relationship of a <b. . When this relationship is a ≧ b, it is difficult to efficiently obtain the luminance of the phosphor, and the object of the present invention cannot be achieved.

The layer (A) is not particularly limited as long as it is a resin composition layer containing a phosphor. Usually, the phosphor is dispersed in a resin composition comprising a base polymer and an ethylenically unsaturated compound. The layer of the resin composition is used, and the layer (B) is not particularly limited as long as it is a resin composition layer containing a phosphor, like the layer (A).
When the layer (B) is located on the uppermost layer, usually, a layer of a photosensitive resin composition in which a phosphor is dispersed in a photosensitive resin composition comprising a base polymer, an ethylenically unsaturated compound and a photopolymerization initiator. Is used. In the layer (A), a photosensitive resin composition comprising a base polymer, an ethylenically unsaturated compound and a photopolymerization initiator can be used as the resin composition, similarly to the layer (B). As such a base polymer, an acrylic resin, a polyester resin, a polyurethane resin, or the like is used. Among these, (meth) acrylate is a main component, and an ethylenically unsaturated carboxylic acid or another copolymer is used as necessary. Acrylic copolymers obtained by copolymerizing polymerizable monomers are important. An acetoacetyl group-containing acrylic copolymer can also be used.

Here, the (meth) acrylic acid ester includes methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate,
-Ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, and the like. You.

As the ethylenically unsaturated carboxylic acid, monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid are preferably used. In addition, dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, and their anhydrides Products and half esters can also be used. Of these, acrylic acid and methacrylic acid are particularly preferred. It is also preferable that the photosensitive resin composition is of a dilute alkali developing type. When the photosensitive resin composition is of a dilute alkali developing type, the ethylenically unsaturated carboxylic acid is contained in an amount of about 15 to 30% by weight (acid value of 100 to 200 mg KOH / g). Degree) It is necessary to copolymerize. Examples of other copolymerizable monomers include acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, and alkyl vinyl ether.

Further, as the ethylenically unsaturated compound,
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl Glycol di (meta)
Acrylate, 1,6-hexane glycol di (meth)
Acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, 2,2-bis (4 -(Meth) acryloxydiethoxyphenyl) propane, 2,2-bis- (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3-
(Meth) acryloyloxypropyl (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, glycerin triacrylate, glycerin poly Examples include polyfunctional monomers such as glycidyl ether poly (meth) acrylate, and the mixing ratio of the ethylenically unsaturated compound is 10 to 200 parts by weight with respect to 100 parts by weight of the base polymer.
In particular, it is desirable to select from the range of 60 to 150 parts by weight. An insufficient amount of the ethylenically unsaturated compound causes a decrease in the flexibility of the layer (A) and the layer (B), causes poor curing of the layer and delays the development speed, and conversely, an excessive amount of the ethylenically unsaturated compound. Is not preferred because it causes a cold flow and a decrease in the peeling rate of the cured resist in the layer.

An appropriate amount of a monofunctional monomer can be used together with these polyfunctional monomers. Examples of such a monofunctional monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, -Hydroxybutyl (meth) acrylate, 2-
Phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth)
Acrylate, 2- (meth) acryloyloxyethyl acid phosphate, half (meth) acrylate of a phthalic acid derivative, N-methylol (meth) acrylamide and the like can be mentioned.

The photopolymerization initiator includes benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n
-Butyl ether, benzoin phenyl ether, benzyl diphenyl disulfide, benzyl dimethyl ketal, dibenzyl, diacetyl, anthraquinone, naphthoquinone, 3,3'-dimethyl-4-methoxybenzophenone, benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4,4'-diethylaminobenzophenone, pivaloin ethyl ether, 1,1-dichloroacetophenone, pt-butyldichloroacetophenone, hexaarylimidazole dimer, 2,2 ' −
Bis (o-chlorophenyl) 4,5,4 ′, 5′-tetraphenyl), and the like, and such a photopolymerization initiator may have a total amount of 10
It is preferable to mix 0 to 20 parts by weight with respect to 0 parts by weight.

The content of the phosphor in the layers (A) and (B) is preferably 1 to 800 parts by weight, more preferably 10 to 800 parts by weight, based on 100 parts by weight of the total amount of the base polymer and the ethylenically unsaturated compound. The amount is 500 parts by weight, and if the amount of the phosphor is too small, the emission luminance is lowered. On the other hand, if the amount is too large, the surface tackiness of a film to be described later is undesirably reduced. In the present invention, the average particle diameters a and b of the phosphor contained in the layer (A) and the layer (B) are such that a <a
It suffices that the relationship of b is satisfied, but 1 <b /
It is preferable that the relationship a ≦ 10 is satisfied.
If a exceeds 10, it becomes difficult to fix the phosphor, which is not preferable. More preferably, 1.5 <b / a ≦ 3.

[0015] The thickness of the layer _(A) (h _a) is not be indiscriminately also varies depending on the structure of the content and PDP phosphor, it usually is thinner than the partition wall side height (h ₀₎ preferably, even such h _a ([mu] m) and h ₀ (μm) is h _a
/ H ₀ = 1/20 to 15/20,
Particularly preferably _{h a / h 0 = 1 /} 20~10 / 20, according h _a / h ₀ is the phosphor insufficient thickness after firing is less than 1/20, it exceeds 15/20 reversed The space at the time of discharge of the cell is reduced, which is not preferable, and the thickness (h _b ) of the layer (B) also differs depending on the content of the phosphor and the structure of the PDP, and cannot be said unconditionally.
Similar to _a, thinner is more preferable than the partition wall side height (h _0), even according h _b (μm) and h ₀ (μm) is h _b / h ₀
= 1/20 to 15/20, especially h
It is preferable that _b / h ₀ = 1/20 to 10/20,
When the ratio h _b / h ₀ is less than 1/20, it is difficult to sufficiently push the above-mentioned phosphor-containing layer (A) into the partition walls (cells). Not preferred. Further, the layer (A) and the layer (B)
It is highly preferable that such a layer is previously formed into a film or a sheet in view of uniform dispersibility, followability, workability, and the like of the phosphor.

Further, in the above-mentioned layers (A) and (B),
In addition, addition of dyes (coloring and coloring), adhesion promoters, plasticizers, antioxidants, thermal polymerization inhibitors, solvents, surface tension modifiers, stabilizers, chain transfer agents, defoamers, flame retardants, etc. Agents can also be added as appropriate. Further, it is preferable that the layer (A) and the layer (B) are previously formed into a film as described above. Specifically, the photosensitive resin composition containing the above-mentioned phosphor is prepared by mixing a polyester film, a polypropylene film, and a polystyrene film. It is preferable that after coating on a base film surface such as a film, a protective film such as a polyethylene film or a polyvinyl alcohol film is coated on the coated surface to form a laminate, which is then used for fixing the phosphor. The method for fixing the phosphor of the present invention will be specifically described.

(Formation of Layer (A)) Adhesion between a base film (polyester film, polyvinyl alcohol film, nylon film, cellulose film, etc.) of a laminate having the above layer (A) as an intermediate layer and a resin composition layer. By comparing the force and the adhesive strength between the protective film and the resin composition layer, the film having the lower adhesive strength is peeled off, and then the resin composition layer is placed on the PDP substrate on which the partition walls (cells) are formed in advance. The layer (A) is formed by pressing the layer (A) into the partition (cell) using a hot laminator or the like.
(Formation of Layer (B)) The film remaining on the surface of the layer (A) was peeled off, and a laminate having the layer (B) as an intermediate layer was formed thereon using a hot laminator or the like in the same manner as the layer (A). To form a layer (B).

(Exposure) Exposure is performed by bringing a pattern mask into close contact with the layer (B). If necessary, and if the layer (B) has no tackiness, the film on the surface of the layer (B) is peeled off, and then the pattern mask is directly contacted with the layer (B) for exposure. Can also. Exposure is usually performed by ultraviolet irradiation, and the light source at this time is a high-pressure mercury lamp,
Ultra-high pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, chemical lamps and the like are used. After irradiation with ultraviolet rays, heating can be performed as necessary to complete the curing.

(Development) After exposure, the film on the layer (B) is peeled off and developed. Since the layer (B) is a photosensitive resin composition of a rare alkali development type, development after exposure is performed with an alkali 1 such as sodium carbonate or potassium carbonate.
This is performed using a dilute aqueous solution of about 2% by weight. At this time, it is also possible to use a developer such as an organic alkali.

(Firing) The partition (cell) forming substrate after the above treatment is baked at 450 to 550 ° C. to fix the phosphor inside the partition (cell). Thus, according to the method of the present invention,
The phosphor can be fixed in the partition (cell). To form a full-color PDP, the above-mentioned ((A) and (B)) are used using the respective layers (A) and (B) of red, blue, and green. After the formation of the layer (A)) to (development) are repeated, the phosphor of the above three colors (R (red), G (green), and B (blue)) is filled in the cell, and then (firing) is performed. By doing so, it can be manufactured.

As described above, the two layers (A) and (B)
In the present invention, three or more layers (layer (C), layer (D), layer (E),...) Can be further repeated. It is sufficient that the lower layer and the upper layer to be formed satisfy the above-mentioned relationship between the conditions of the layer (A) and the layer (B). That is, when the layer (C) is further laminated on the layer (B), the relationship between the layer (B) and the layer (C) is the relationship between the conditions of the layer (A) and the layer (B) of the present invention. Is satisfied, and the layer (D) is further formed on the layer (C).
Are laminated, the relationship between the layer (C) and the layer (D) is
The relationship between the conditions of the layer (A) and the layer (B) of the present invention may be satisfied, and the layer (C), the layer (D), the layer (E), When three or more layers are laminated with..., Only the uppermost layer may be a photosensitive resin composition layer, and none of the layers below it need be a photosensitive resin composition layer. Further, in the present invention, the layer (C) is a photosensitive resin composition layer containing no phosphor, and is used as a partition (cell).
It is also preferable to sequentially provide the layer (A), the layer (B) and the layer (C) therein. In this case, the layer (B) may be a resin composition layer as described above.

[0022]

The present invention will be specifically described below with reference to examples. In the examples, "parts" means on a weight basis unless otherwise specified. Example 1 A resin composition used for the layer (A) was prepared by mixing 50 parts of the following phosphor, 50 parts of the following base polymer, and 80 parts of the following ethylenically unsaturated compound. Phosphor Y ₂ O ₂ S: Eu (emission wavelength: 642 nm, average particle size: 2.2 ± 0.5
μm) Base polymer methyl methacrylate / n-butyl methacrylate / 2
- copolymer copolymerization proportion is 55/8/15/22 by weight of ethyl hexyl acrylate / methacrylic acid (acid value 143.3, glass transition point 66.3 ° C., a weight average molecular weight 80,000) ethylenically unsaturated Mixture of saturated compound glycerin triacrylate (“OTA-480” manufactured by Daicel UBC) / ethylene oxide-modified phthalic acid acrylate / tremethylolpropane triacrylate in a weight ratio of 1/1/1.

Next, the obtained resin composition was filled in gap 1
Using a 0 mil applicator, coat on a polyester film having a thickness of 20 μm, leave at room temperature for 1 minute and 30 seconds, and in an oven at 60 ° C., 90 ° C. and 110 ° C. for 3 minutes each.
And dried by minutes, to prepare a laminate having the thickness (h _a) 40 [mu] m layer of (A). (However, no protective film is provided.) Further, the above-mentioned phosphor is made of Y ₂ O ₂ S: Eu (emission wavelength;
2 nm, average particle diameter: 5.5 ± 0.5 μm)
Further, a layered product of a layer (B) having a thickness (h _b ) of 30 μm was prepared in the same manner as in the layer (A) except that the following photopolymerization initiator was blended. (However, no protective film is provided) Photopolymerization initiator benzophenone / 4,4′-diethylaminobenzophenone / 2,2-bis (o-chlorophenyl) 4,5
Mixture of 4 ', 5'-tetraphenyl-1,2'-biimidazole in a weight ratio of 8 / 0.15 / 1

Using the obtained laminate of the layer (A) and the layer (B), a phosphor was fixed in the following manner. (Formation of Layer (A) and Layer (B)) PDP substrate (200 mm × 200 mm ×) on which a partition (a stripe pattern having a height (h ₀ ) of 100 μm, a width of 80 μm, and a slit of 150 μm) preheated to 60 ° C. in an oven was formed. 2 mm), and a laminate of the above layer (A) is laminated at a laminating roll temperature of 100.
° C, roll pressure 3 kg / cm ² , lamination speed 1.0 m
After laminating under the conditions of / sec, the polyester film was peeled off, and the layered product of the layer (B) was similarly laminated thereon to form the layer (A) and the layer (B).
_{(H a / h b = 40} /30)

(Exposure and Development) Next, a pattern is placed on the entire surface of the polyester film on the surface of the layer (B) such that the inside of the partition (cell) (other than the upper part of the partition) is exposed, Exposure machine HMW-532D 3
Exposure was performed at 80 mj with a kw ultrahigh pressure mercury lamp. 15 after exposure
After a hold time of 1 minute, development was carried out using a 1% aqueous solution of Na ₂ CO _{3 at} 30 ° C. for 1.5 times the minimum development time.

(Firing) After development, put in a firing furnace for about 5 minutes.
The temperature was raised to 50 ° C. to burn off the resin components in the layers (A) and (B) and at the same time fix the phosphor in the partition (cell).

Example 2 In Example 1, the average particle diameter of the phosphor in the layer (A) was 2.2 μm, and the average particle diameter of the phosphor in the layer (B) was 8 μm.
The same procedure was performed except that the thickness was changed to μm to obtain a partition substrate on which the phosphor was fixed.

[0028] Example 3 In Example 1, the layer thickness of _(A) (h _a) 30μm
And then, the layer (B) is a thickness (h _b) of the 40 [mu] m (h _a /
h _b = 30/40) than is carried out in the same manner to obtain a partition substrate on which phosphors are fixed.

[0029] Example 4 In Example 1, the layer thickness of _(A) (h _a) 20μm
And then, the thickness of the layer (B) and (h _b) and 20μm (h _a / h
_b = _20/20 ), and a layer (C) having a thickness (h _c ) of 30 μm excluding the phosphor from the composition of the layer (B) is further laminated, and the same procedure is performed to obtain a partition substrate on which the phosphor is fixed. Was.

Reference Example The same procedure as in Example 1 was carried out except that the layer (B) was used instead of the layer (A) (two layers of the layer (B) were laminated) to form a partition wall on which the phosphor was fixed. A substrate was obtained.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the phosphors of the layer (A) and the layer (B) were reversed, to obtain a partition substrate on which the phosphor was fixed. The partition board substrate on which the phosphors obtained in the above Examples, Reference Examples and Comparative Examples were fixed was irradiated with an ultraviolet sterilizing lamp (GL10, manufactured by Toshiba Corporation) at 20 ° C., and the relative luminance was visually evaluated. As a result, it was confirmed that the partition board of the comparative example was equivalent to that of the reference example, whereas the partition boards of the examples were much more excellent in luminance than that of the reference example.

[0032]

According to the method for fixing a phosphor of the present invention, two kinds of phosphors having a specific particle diameter relationship are contained (resin composition).
Since the layer is formed so as to be filled in the partition (cell), the phosphor can be efficiently fixed to the side wall and the bottom of the partition (cell), and the luminance can be efficiently obtained.
It is very useful for forming phosphors such as P.

Claims (6)

[Claims] When a phosphor is fixed in a partition wall (cell) of a plasma display panel, the partition wall (cell) has an average particle diameter of a (μ) so as to satisfy the following expression (1).
m) a resin composition layer containing a phosphor (A) and a resin composition layer containing a phosphor having an average particle diameter of b (μm) (B) are sequentially provided, and then exposed and developed. A method for fixing a phosphor, characterized by firing. a <b (1) 2. Average particle diameter a (μm) and average particle diameter b
2. The method according to claim 1, wherein (μm) satisfies the following expression (2). 1 <b / a ≦ 10 (2) 3. The method for fixing a phosphor according to claim 1, wherein a photosensitive resin composition layer (C) containing no phosphor is further provided on the layer (B). 4. The layer (A) contains a base polymer, an ethylenically unsaturated compound and a phosphor, and the content of the phosphor is 1 to 800 with respect to 100 parts by weight of the total amount of the base polymer and the ethylenic compound. The method for fixing a phosphor according to any one of claims 1 to 3, wherein the resin composition layer is a part by weight. 5. The layer (B) contains a base polymer, an ethylenically unsaturated compound and a phosphor, and the content of the phosphor is 1 to 800 with respect to 100 parts by weight of the total amount of the base polymer and the ethylenic compound. The resin composition layer, which is part by weight, or contains a base polymer, an ethylenically unsaturated compound, a photopolymerization initiator, and a phosphor, and the content of the phosphor is 100 parts by weight in total of the base polymer and the ethylenic compound. The method for fixing a phosphor according to any one of claims 1 to 4, wherein the photosensitive resin composition layer is any one of the photosensitive resin composition layers in an amount of 1 to 800 parts by weight. 6. The method according to claim 1, wherein
A method of fixing a phosphor, comprising repeating the process three times to fix phosphors of R (red), G (green), and B (blue).