KR100898294B1 - Paste composition for plasma display panel - Google Patents

Abstract

The present invention relates to a paste composition for a plasma display panel, wherein the paste composition comprises inorganic particles; A binder whose terminal is substituted with an acidic group or a basic group; And solvents.

Since the paste composition for plasma display panel of the present invention exhibits high dispersibility even without a separate dispersant, the phosphor may be used in a larger amount when applied to the phosphor composition, thereby increasing the luminous efficiency of the plasma display panel. Can be. In addition, even when applied to the formation of the dielectric layer, barrier ribs or electrodes can increase the content of solids, it is possible to obtain the desired physical properties more effectively.

PDP, Dispersant, Acid, Base, Binder, Phosphor

Description

Paste composition for plasma display panel {PASTE COMPOSITION FOR PLASMA DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste composition for plasma display panels and to a paste composition for plasma display panels with excellent dispersibility.

In general, a plasma display panel (PDP) is a display device that realizes an image by using visible light generated by vacuum ultraviolet (VUV) radiation emitted from a plasma formed by gas discharge to excite a phosphor layer. The plasma display panel has a high resolution and large screen configuration, and has been spotlighted as a next generation thin display device.

A plasma display panel generally used at present is a reflective AC drive plasma display panel, and in the case of a bottom plate structure, a phosphor layer is formed on a partition wall.

The phosphor layer is prepared using a phosphor paste composition prepared by mixing a phosphor and a binder in a solvent. However, when only phosphors and binders are used, there is a problem in that it is difficult to implement characteristics after the process is applied due to poor phosphor dispersibility.

In order to solve such a problem, a dispersant is additionally used, but in this case, the process of preparing the paste composition has a problem in that the process of adding the dispersant is additionally performed. In addition, the dispersant and the binder may not act on the surface of the powder due to the complexing through interaction, which may adversely affect the dispersibility of the paste.

An object of the present invention is to provide a paste composition for plasma display panel that can improve dispersibility.

However, the technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems will be clearly understood by those skilled in the art from the following description.

One embodiment of the present invention for achieving the above object is an inorganic particle; A binder substituted with an acidic group or a basic group; And it provides a paste composition for a plasma display panel containing a solvent.

As the paste composition of the present invention uses a binder substituted with an acidic group or a basic group, a high dispersing effect can be obtained without using a separate dispersant. In addition, by using a binder in which both the acidic group and the basic group are substituted, the inorganic particles can be dispersed in both acidic and basic properties, and the effect can be further increased.

Other specific details of embodiments of the present invention are included in the following detailed description.

As the paste composition for plasma display panel of the present invention exhibits high dispersibility even without a separate dispersant, when applied to a phosphor composition, the phosphor can be used in a larger amount, thereby increasing the luminous efficiency of the plasma display panel. You can. In addition, even when applied to the formation of the dielectric layer, barrier ribs or electrodes can increase the content of solids, it is possible to obtain the desired physical properties more effectively.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

One embodiment of the present invention relates to a paste composition for a plasma display panel. The paste composition for plasma display panel of the present invention contains a binder and a solvent in which inorganic particles, acidic groups or basic groups are substituted.

In the present invention, the binder is substituted with an acidic group or a basic group, and all of them include an acidic group or a basic group regardless of whether the terminal of the binder is substituted with an acidic group or a basic group, or an acidic group or a basic group is bonded to the main chain. It can be used preferably. As such, the acidic group or the basic group is combined with the basic or acidic group of the inorganic particles to be used, thereby making it possible to evenly disperse in the solvent.

In other words, it is possible to obtain an optimum dispersion state by selecting an appropriate binder depending on the acidity or basicity of the surface of the inorganic particles to be used. In more detail, it is preferable to use a binder substituted with a basic group if the surface of the inorganic particle to be used has a strong acidity, and a binder substituted with an acidic group if the surface of the inorganic particle has a strong basicity.

In this case, the degree of substitution of the binder substituted with an acidic group or a basic group is preferably 1 to 20%. At this time, if the substitution degree is less than 1%, the binder is difficult to bond to the surface of the inorganic particles, and if it exceeds 20%, it is possible to impart a viscosity to the paste composition, delay the sedimentation of the inorganic particles, or maintain the strength of the molded film. It is not preferable because it is difficult to perform the natural functions of the binder.

The acid group is preferably selected from the group consisting of carboxylic acid groups, phosphoric acid groups, sulfonic acid groups and the like, and the basic group is preferably selected from the group consisting of amine groups and the like.

Examples of the binder of the present invention include cellulose, acrylate, butyral or alcohol.

Specific examples of the cellulose binder include methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy methyl cellulose, hydroxy ethyl cellulose, hydroxy propyl cellulose, hydroxy ethyl propyl cellulose, or mixtures thereof. Specific examples of the acrylate binder include poly methyl methacrylate, poly isopropyl methacrylate, poly isobutyl methacrylate, or methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, Hexylmethacrylate, 2-ethyl hexyl methacrylate, benzyl methacrylate, dimethyl amino ethyl methacrylate, hydroxyethyl methacrylate, hydroxy propyl methacrylate, hydroxy butyl methacrylate, phenoxy 2 Hydroxy propyl methacrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethyl hexyl acrylate, benzyl acrylate, dimethyl amino ethyl acrylic Late, hide When there may be mentioned a copolymer, or a mixture of acrylic monomers such as ethyl acrylate, hydroxy propyl acrylate, hydroxy butyl acrylate, phenoxy 2-hydroxy propyl acrylate, glycidyl acrylate.

Polyvinyl butyral etc. are mentioned as said butyral-type binder.

Examples of the alcohol binder include polyvinyl alcohol and the like.

The content of the binder substituted with an acidic group or a basic group of the present invention is preferably 0.01 to 0.2 parts by weight, more preferably 0.1 to 0.15 parts by weight relative to the inorganic particles. If the content of the binder is less than 0.01 part by weight, the content of the binder in the composition is too small, there is a problem that the rheological properties inherent in the phosphor composition is not expressed, it is not preferable, if exceeding 0.2 parts by weight, using a substituted binder It is not preferable because the dispersing effect is not obtained.

The acid value substituted with an acidic group in the binder of the present invention is preferably 1 to 200 mgKOH / g, more preferably 1 to 100 mgKOH / g. The acid value represents the number of mg of KOH consumed to neutralize the binder of the present invention. Since the binder substituted with an acidic group is substituted with an acidic group, basicity is 0 mg / KOH.

In addition, the binder substituted with a basic group in the binder of the present invention preferably has a basicity of 1 to 200 mgKOH / g, more preferably 1 to 100 mgKOH / g. Since the binder in which the basic group is substituted is that in which the basic group is substituted, the acid value is 0 mg / KOH.

If the binder of this invention has the said acid value and basicity, since the adsorption | suction of an inorganic particle surface and a binder arises easily, it is preferable.

Alcohol, ether, ester, or a mixture thereof may be used as the solvent. The alcohol may be ethanol, butyl carbitol, texanol, dihydroterpineol, terpineol, or a mixture thereof. More preferably, butyl carbitol BC, butyl carbitol acetate (BCA), terpineol or a mixture thereof may be used.

The paste composition of the present invention may be usefully used to form the phosphor layer, and may be used in all fields to which the paste composition of the plasma display panel is applied, such as barrier ribs, dielectrics, or electrode formation.

Therefore, the inorganic particles may be variously changed according to the field to be applied, and representative examples thereof include a phosphor, a dielectric, or a conductor.

The content of the inorganic particles is preferably 5 to 50% by volume. If the content of the inorganic particles is less than 5% by volume, the main effect of using the inorganic particles (for example, the luminous efficiency when the inorganic particles are phosphors) is not preferred, and if the content exceeds 50% by volume, the viscosity is too high. Not preferred.

The phosphor may be a red phosphor, a green phosphor or a blue phosphor, and the red phosphor may be (Y, Gd) BO ₃ : Eu, Y (P, V) O ₄ : Eu, (Y, Gd) ₂ O ₃ : Eu or Y ₂ O ₃ : Eu. The green phosphor includes Zn ₂ SiO ₄ : Mn, YBO ₃ : Tb, (Zn, A) ₂ SiO ₄ : Mn (A is an alkali metal) or a mixture thereof, and the phosphor and BaAl ₁₂ O ₁₉ : Mn , (Ba, Sr, Mg) O.αAl ₂ O ₃ : Mn (α is 1 to 23), MgAl _x O _y : Mn (x is 1 to 10, y is 1 to 30), LaMgAl _x O _y : Tb At least one selected from the group consisting of Mn (x is 1 to 14, y is 8 to 47), and ReBO ₃ : Tb (Re is at least one rare earth element selected from Sc, Y, La, Ce, and Gd) It is also possible to use a mixture of phosphors. When the mixture is used in this way, the green phosphor selected from the group consisting of Zn ₂ SiO ₄ : Mn, YBO ₃ : Tb, (Zn, A) ₂ SiO ₄ : Mn (A is an alkali metal) and mixtures thereof is 10 to 10. Preference is given to using in amounts of 10 to 70% by weight.

In addition, as the blue phosphor, BaMgAl ₁₀ O ₁₇ : Eu, CaMgSi ₂ O ₆ : Eu, CaWO ₄ : Pb, Y ₂ SiO ₅ : Eu, or a combination thereof may be used.

As the dielectric, any one generally used to form a dielectric layer of a plasma display panel may be used, and representative examples thereof may include lead oxide-based or non-lead oxide-based low melting point amorphous glass.

As the lead oxide or non-lead oxide low melting point amorphous glass, PbO, ZnO, B ₂ O ₃ , Al ₂ O ₃ , SiO ₂ , SnO, P ₂ O ₅ , Sb ₂ O ₅ , BaO, TiO ₂ and Bi ₂ O _At least one selected from the group consisting of ₅ is preferable, and lead oxide-boron oxide-silicon oxide-based (PbO-B ₂ O ₃ -SiO ₂ ), lead oxide-zinc oxide-boron oxide-silicon oxide-aluminum oxide-based (PbO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ ), zinc oxide-boron oxide-silicon oxide (ZnO-B ₂ O ₃ -SiO ₂ ), zinc oxide-boron oxide-silicon oxide-aluminum oxide (ZnO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ ), Lead Oxide-Zinc Oxide-Boron Oxide-Silicon Oxide (PbO-ZnO-B ₂ O ₃ -SiO 2), Lead Oxide-Zinc Oxide-Boron Oxide -Silicon oxide-aluminum oxide (PbO-ZnO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ ), bismuth oxide-boron oxide-silicon oxide (Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ ), Bismuth oxide-Boron oxide-Silicon oxide-Aluminum oxide type (Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ ), Bismuth oxide-Zinc oxide-Boron oxide-Silicon oxide type (Bi ₂ O _3- ZnO-B ₂ O ₃ -SiO ₂ ), bismuth oxide-zinc oxide-boron oxide-silicon oxide-aluminum oxide type (Bi ₂ O ₃ -ZnO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ ), zinc oxide-silicon oxide type At least one selected from the group consisting of (ZnO-SiO ₂ ) and bismuth oxide-silicon oxide system (Bi ₂ O ₃ -SiO ₂ ) is preferable.

The phosphor composition may further include other additives to improve flow characteristics, process characteristics, and the like. As the additive, for example, various additives such as a photosensitizer, a dispersant, a silicone-based antifoaming agent, a leveling agent, a plasticizer, an antioxidant, etc. may be used alone or in combination, all of which are commonly used in the art. Available to those with knowledge of

The following presents specific embodiments of the present invention. However, the examples described below are merely for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

(Example 1)

BaMgAl ₁₀ O ₁₇ : A mixed solvent of terpineol / butyl carbitol acetate using an ethyl cellulose (ie, carboxylated ethyl cellulose) binder in which an Eu blue phosphor and a carboxyl group are substituted at the end. 3 volume ratios) to prepare a blue phosphor paste composition. The degree of substitution of the carboxylated ethyl cellulose was 1.92%, an acid value of 9.6 mgKOH / g, and a basicity of 0 mgKOH / g. At this time, the ratio of the amount of carboxylated ethyl cellulose to the amount of phosphor used (the amount of carboxylated ethyl cellulose / phosphor) was 0.01 weight ratio. In addition, the total solid content of the phosphor and the binder was 49% by weight, wherein the content of the phosphor was about 48.5% by weight and the content of the binder was about 0.5% by weight. In addition, the solid volume fraction of the phosphor was 20% by volume.

The phosphor paste composition was applied to a discharge cell and then fired to form a blue phosphor layer, thereby manufacturing a plasma display panel in a conventional manner.

(Example 2)

It carried out similarly to Example 1 except having changed the usage-amount ratio (usage of carboxylated ethyl cellulose / fluorescent substance) of carboxylated ethyl cellulose to 0.03 weight ratio.

(Example 3)

It carried out similarly to Example 1 except having changed the usage-amount ratio (usage of carboxylated ethyl cellulose / fluorescent substance) of carboxylated ethyl cellulose with respect to fluorescent substance usage to 0.05 weight ratio.

(Example 4)

It carried out similarly to Example 1 except having changed the usage-amount ratio (usage of carboxylated ethyl cellulose / fluorescent substance) of the carboxylated ethyl cellulose with respect to fluorescent substance usage to 0.1 weight ratio.

(Example 5)

It carried out similarly to Example 1 except having changed the usage-amount ratio (usage of carboxylated ethyl cellulose / fluorescent substance) of carboxylated ethyl cellulose to 0.15 weight ratio.

(Example 6)

It carried out similarly to Example 1 except having changed the usage-amount ratio (usage of carboxylated ethyl cellulose / fluorescent substance) of carboxylated ethyl cellulose with respect to fluorescent substance usage to 0.2 weight ratio.

(Example 7)

The same procedure as in Example 2 was carried out except that the solid content of the phosphor was changed to 30% by volume.

(Example 8)

The same process as in Example 2 was carried out except that the solid content of the phosphor was changed to 37.5% by volume.

(Example 9)

The same procedure as in Example 2 was carried out except that the solid content of the phosphor was changed to 45% by volume.

(Example 10)

The same process as in Example 2 was carried out except that the solid content of the phosphor was changed to 47.5% by volume.

(Example 11)

A plasma display panel was manufactured in the same manner as in Example 1, except that (Y, Gd) BO ₃ : Eu, Y (P, V) O ₄ : Eu green phosphors were used.

(Example 12)

A plasma display panel was manufactured in the same manner as in Example 1, except that Zn ₂ SiO ₄ : Mn and YBO ₃ : Tb red phosphors were used.

(Comparative Example 1)

Except for using the ethyl cellulose binder terminal is not substituted with a carboxyl group was carried out in the same manner as in Example 1.

(Comparative Example 2)

The same procedure as in Example 2 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 3)

The same procedure as in Example 3 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 4)

The same procedure as in Example 4 was carried out except that the ethyl cellulose binder was not substituted at the terminal with a carboxyl group.

(Comparative Example 5)

The same procedure as in Example 5 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 6)

The same procedure as in Example 6 was carried out except that the ethyl cellulose binder was not substituted at the terminal with a carboxyl group.

(Comparative Example 7)

The same procedure as in Example 7 was carried out except that the ethyl cellulose binder was not substituted at the terminal with a carboxyl group.

(Comparative Example 8)

The same procedure as in Example 8 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 9)

The same procedure as in Example 9 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 10)

The same procedure as in Example 10 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 11)

The same procedure as in Example 11 was carried out except that an ethyl cellulose binder in which the terminal was not substituted with a carboxyl group was used.

(Comparative Example 12)

The same procedure as in Example 12 was carried out except that the ethyl cellulose binder was not substituted at the terminal with a carboxyl group.

* Evaluation of phosphor acid / base properties

The acid / base characteristics of the surface of the blue phosphor used in Example 1 were evaluated. In the evaluation method, the blue phosphor used in Example 1 was added to 0.01 M NaNO ₃ solution in an amount of 1% by weight, and then aged for 12 hours to prepare a suspension. Thereafter, the electrophoretic characteristics of the surface of the phosphor were evaluated while adjusting the hydrogen ion concentration of the suspension, and the isoelectric point was confirmed at pH 9.8, and the results are shown in FIG. 1. In addition, the acid value and basicity which existed on the surface of fluorescent substance powder were measured using the nonaqueous potential titration method (inset of FIG. 1). At this time, the acid value (mg / KOH / g) was 0.069, the basicity (mg / KOH / g) was 0.156. Therefore, it was confirmed that the blue phosphor surface had basic characteristics overall.

* Substitution degree evaluation

In order to determine the degree of substitution of the carboxyl group of the binder used in Example 1, IR was measured, and the results are shown in FIG. 2. In addition, IR results of ethyl cellulose, in which the carboxyl group of Comparative Example 1 is not substituted, are also shown in FIG. 2 for comparison. As shown in Figure 2, the binder used in Example 1, unlike the Comparative Example 1, it can be seen that the C = O peak appeared that the terminal was substituted with a carboxyl group. In addition, the degree of substitution was measured and the results are shown in Table 1 below.

Ethyl Cellulose (Comparative Example 1) Carboxyl Substituted Ethyl Cellulose (Example 1) Number average molecular weight (g / mol) 10,500 10,500 Acid value (mgKOH / g) 1.104 9.577 % Substitution of COOH in OH 0 1.92

* Dispersion effect measurement

An experiment was conducted to determine the dispersion effect of the carboxylic acid group-substituted ethyl cellulose used in Examples 1 to 6.

Dispersion effect experiments were evaluated by measuring the relative viscosity of the paste compositions prepared according to Examples 1-6 and Comparative Examples 1-6. The results are shown in FIG. In Fig. 3, a1, a2, a3, a4, a5 and a6 denoted by ○ indicate Examples 1, 2, 3, 4, 5 and 6, and b1, b2, b3, b4, b5 and b6 denoted by ■ are compared. Examples 1, 2, 3, 4, 5 and 6 are shown. As shown in FIG. 3, it was found that the viscosity value decreased as the amount of the binder used on the phosphor (y-axis: represented by EC / Phosphor) increased, that is, as the polymer concentration increased. In addition, in all the concentration ranges tested, the paste containing the carboxylic acid-substituted ethyl cellulose had a lower viscosity than the conventional paste containing the ethyl cellulose. As a result, it can be seen that the carboxylated ethyl cellulose of Examples 1 to 6 can exhibit excellent dispersion efficiency compared to the general ethyl cellulose used in Comparative Examples 1 to 6.

Relative viscosity evaluation

In order to determine the relative viscosity of the paste according to the increase in the solid content, the relative viscosities of Examples 2 and 7 to 10 and Comparative Examples 2 and 7 to 10 were evaluated. The results are shown in FIG. In FIG. 4, a7, a8, a9, a10, a10 and a11 denoted Examples 2, 7, 8, 9 and 10, and b7, b8, b9, b10 and b11 denoted by ■ are Comparative Examples 2, 7, 8 , 9 and 10. As shown in FIG. 4, in Examples 2 and 7 to 10 using carboxylated ethyl cellulose, the relative viscosity was relatively low compared to Comparative Examples 2 and 7 to 10 using ethyl cellulose. According to this result, it can be predicted that in the case of carboxylated ethyl cellulose, a larger amount of phosphor can be included in the paste slurry of the same viscosity, and thus, it is possible to increase the luminous efficiency.

The present invention is not limited to the above embodiments, but may be manufactured in various forms, and a person skilled in the art to which the present invention pertains has another specific form without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is a graph showing the measurement of the acid / base properties of the surface of the blue phosphor used in Example 1 of the present invention.

2 is an IR measurement graph of the binder used in Example 1 and Comparative Example 1 of the present invention.

Figure 3 is a graph showing the relative viscosity measured according to the binder concentration of the paste composition prepared according to Examples 1 to 6 and Comparative Examples 1 to 6 of the present invention.

Figure 4 is a graph showing the relative viscosity measured with increasing solids content of the paste composition prepared according to Examples 7 to 11 and Comparative Examples 7 to 11 of the present invention.

Claims (10)

Inorganic particles 5 to 50% by volume; A binder substituted with an acidic group or a basic group; And menstruum Plasma display panel paste composition comprising a. The method of claim 1, Wherein the acidic group is selected from the group consisting of a carboxylic acid group, a phosphoric acid group and a sulfonic acid group. The method of claim 1, Paste composition for a plasma display panel, wherein the basic group is an amine group. The method of claim 1, The binder substituted with an acidic group or a basic group has a substitution degree of 1 to 20%. The method of claim 1, The binder substituted with the acidic group is a plasma display panel paste composition having an acid value of 1 to 200mgKOH / g. The method of claim 1, The binder substituted with the basic group is a plasma display panel paste composition having a basicity of 1 to 200mgKOH / g. The method of claim 1, The binder is selected from the group consisting of cellulose, acrylate, butyral, alcohol, and combinations thereof. The method of claim 1, The binder content is a plasma display panel paste composition is 0.01 to 0.2 parts by weight based on 100 parts by weight of the inorganic particles. delete The method of claim 1, The inorganic particles are selected from the group consisting of phosphors, dielectrics and conductors paste composition for a plasma display panel.

Images