JPH07254380A - Insulation coating material and cathode-ray tube using same - Google Patents

Abstract

PURPOSE:To provide a high electric insulation property and realize solvent reproduction by mixing a polysiloxane resin having a condensation reaction group with alkoxy silane and oxime silane each expressed by a predetermined formula. CONSTITUTION:Alkoxy silane and oxime silane each having characteristics as a cross-linking agent are mixed, thus enhancing solvent reproduction of an insulative coating material of an insulative coating film 6 while enhancing an electric insulating property. Namely, alkoxy silane, oxime silane, amino silane, acyloxy silane or the like is used as a cross-linking agent of a polysiloxane resin. In this case, the polysiloxane resin has a condensation reaction radical; alkoxy silane is expressed by a formula: RmSix4-m (wherein R represents a univalent hydrocarbon group; and X, an alkoxyl group); and oxime silane is expressed by a formula: RnSiZ4-n (wherein R represents a univalent hydrocarbon group; and Z, an oxime group). These materials are mixed for use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating coating film formed around the acceleration electrode terminal portion (anode cap) on the outer wall of a funnel bulb in a cathode ray tube.

[0002]

2. Description of the Related Art Generally, a high voltage is applied to an anode cap during operation of a cathode ray tube, so an insulating coating film is formed on the outer wall surface of the valve around the anode cap to protect it from creeping discharge. is doing.

Therefore, the insulating coating film is required to satisfy the following conditions (1) to (5).

(1) It has high electrical insulation. (2) It has a long-term non-peeling property. (3) The coating film part should be colored, such as red or orange, so that the danger of the high voltage part can be identified. (4) The coating film should be fixed relatively quickly, and after the fixing, it should not spread or be contaminated on the parts other than the applied part. (5) The coating film once formed can be wiped off with a specific solvent (hereinafter, this characteristic is referred to as solvent regeneration).

Conventionally, as an insulating coating film around the anode cap of a cathode ray tube, a silicone resin as disclosed in Japanese Patent Publication No. 53-20828 is widely used. However, recently, due to increase in applied voltage,
Further electrical insulation is required.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cathode ray tube having a high electric insulating property and an insulating coating film capable of solvent regeneration formed on the periphery of the anode cap.

[0007]

In order to achieve such an object, the present invention comprises the following means.

[Means 1. ] An insulating coating material in which at least the following materials (A) to (C) are mixed.

(A) Polysiloxane resin having a condensation-reactive group.

Examples of such a material include a methylpolysiloxane resin having a silanol group or a condensation reactive group such as an alkoxy group or an oxime group bonded to a silicon atom, a phenylpolysiloxane resin, and the like.
Methylphenyl polysiloxane resin, methyl vinyl polysiloxane resin and the like are used. The amount of condensation-reactive groups contained in such a polysiloxane resin is usually 0.1 to 5% by weight.

(B) General formula RmSiX4-m (R is a monovalent hydrocarbon group and X is an alkoxy group.
m is an integer of 1 or 2. ) Alkoxysilane.

Examples of such materials include methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane and phenyl. Triethoxysilane, diphenyldiethoxysilane, etc. are used.

The blending amount of this component is usually 100 to 200 with respect to 100 parts by weight of the polysiloxane resin as the component (A).
It is in the range of parts by weight, preferably in the range of 10 to 100 parts by weight.

(C) General formula RnSiZ4-n (R is a monovalent hydrocarbon group and Z is an oxime group.
Is an integer of 1 or 2. ) Consisting of oxime silane.

As such a material, methyl-tris (methylethylketoxime) silane, dimethyl-bis (methylethylketoxime) silane, phenyl-tris (methylethylketoxime) silane, vinyl-tris (methylethylketoxime) silane, diphenyl-bis (methylethylketoxime) silane, etc. are used. .

The blending amount of this component is usually 100 to 200 with respect to 100 parts by weight of the polysiloxane resin as the component (A).
It is in the range of parts by weight, preferably in the range of 10 to 100 parts by weight.

In addition to this, a curing accelerator and a solvent required as a coating material are mixed, and the curing accelerator in this case is, for example, diethylenetriamine,
Triethylenetetramine, tetraethylenepentamine,
Dibutyltin dioctoate, dibutyltin diacetate,
Dibutyltin dilaurate, tin naphthonate, tin octoate, lead octoate, iron octoate, zinc octoate, tetrabutyl orthotitanate, tetraisopropyl orthotitanate, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetate) and the like are used. Such a curing accelerator accelerates the hydrolysis of the above-mentioned silane compound, thereby promoting the curing of the coating film.

As the solvent, for example, hexane,
Heptane, toluene, xylene, etc. are used. As such a solvent, a volatile solvent which is inert to the above-mentioned materials and has good compatibility with each material is selected.

[Means 2. ] The above-mentioned means 1. In, the mixing ratio of alkoxysilane and oxime silane is 1:10.
Insulating coating material mixed in the range of 10 to 10: 1.

[Means 3. ] As an insulating coating film formed around the acceleration electrode terminal portion on the outer wall of the funnel portion valve, the above means 1. Alternatively, the means 2. A cathode ray tube using the insulating coating material of.

[0021]

It has been confirmed that the insulating coating material thus constructed improves solvent regeneration while improving electrical insulation by mixing alkoxysilane and oxime silane, which have properties as a cross-linking agent. Was done.

That is, as the cross-linking agent for the polysiloxane resin, alkoxysilane, oxime silane, aminosilane or acyloxysilane is used alone. Among them, alkoxysilane or oxime silane is curable and has no bad odor. It is often used.

Alkoxysilane is the most excellent in terms of electric insulation, but it has some drawbacks in curability and the formed coating film is difficult to regenerate with a solvent.

Further, when the composition or the components are adjusted so that the solvent can be regenerated, there is a problem that the electric insulation is deteriorated.

On the other hand, oxime silane is good in terms of curability and can be regenerated with a solvent, but has a problem that its electrical insulating property is slightly inferior.

Therefore, it has been found that the use of alkoxysilane and oxime silane as the cross-linking agent enables solvent regeneration while maintaining high electric insulation.

[0027]

1 is a side view showing an embodiment of a cathode ray tube in which an insulating coating film according to the present invention is formed around an anode cap. 2 is a sectional view taken along line II-II in FIG.

In each figure, 1 is a cathode ray tube comprising a face portion 2, a funnel portion 3 and a neck portion 4.
Reference numeral 5 is an anode cap arranged in the funnel portion 3. 6 is an insulating coating film. Reference numeral 7 is an exterior graphite coating film formed on the outer wall of the funnel portion 3, and reference numeral 8 is glass constituting a cathode ray tube.

Here, the insulating coating film 6 is formed by applying an insulating coating material having a composition described in detail later and drying it.

Next, specific examples of the composition of the insulating coating material used for such a cathode ray tube will be described. Here, all the parts referred to in the respective examples are parts by weight.

The present inventor, in the process of reaching the present invention,
It has been found that an effective means is to use an alkoxysilane as a cross-linking agent and to use a coating liquid having a higher ratio of methyl to an alkyl group in order to improve electric insulation. However, as a side effect, there has been a problem that the curing reaction proceeds and the solvent cannot be regenerated. If the solvent cannot be regenerated, there is a drawback in that mass productivity is extremely deteriorated because it becomes difficult to re-paint again due to the convenience of the manufacturing process, and sometimes all the cathode lines must be discarded.

Therefore, in order to show that the insulating coating films shown in the examples are effective, some comparative examples are also listed at the same time.

Example 1. Methyl polysiloxane resin: 30 parts Methyltrimethoxysilane: 10 parts Methyl-tris (methylethylketoxime) silane: 10 parts Dibutyltin diacetate: 0.5 parts Normal hexane: 50 parts Red coloring material: 0.5 Here, as the methylpolysiloxane resin, a xylene solution containing 50% by weight of methylpolysiloxane resin having a silanol group content of 0.5% by weight (trade name SR2400 manufactured by Toray Dow Corning Silicone Co., Ltd.) is used. I was there.

As the red coloring material, Arsol Red "B" (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) was used.

Then, after stirring and mixing the above components for about 30 minutes in a closed container in which moisture in the air is shut off, spray coating is applied to the anode cap 5 portion of the cathode ray tube and left at room temperature for 24 hours to obtain an insulating coating. The film 6 was formed.

Comparative Example 1. Methyl polysiloxane resin (same as that of Example 1): 30 parts Methyltrimethoxysilane: 20 parts Dibutyltin diacetate: 0.5 parts Normal hexane: 50 parts Red coloring material: 0.5 parts Example 1. The components described above were applied to the cathode ray tube in the same manner as in.

Comparative Example 2. Methyl polysiloxane resin (same as that of Example 1) 30 parts Methyl-tris (methylethylketoxime) silane 20 parts Dibutyltin diacetate 0.5 parts Normal hexane 50 parts Red coloring material 0. 5 parts Example 1. The components described above were applied to the cathode ray tube in the same manner as in.

Example 2. Methylphenylpolysiloxane resin ・ ・ ・ 30 parts Methyltrimethoxysilane ・ ・ ・ 10 parts Methyl-tris (methylethylketoxime) silane ・ ・ ・ 10 parts Dibutyltin diacetate ・ ・ ・ 0.5 parts Normal hexane ・ ・ ・ 50 parts Red coloring material ・ ・ ・ 0. 5 parts Here, as the methylphenylpolysiloxane resin, a xylene solution containing 50% by weight of methylphenylpolysiloxane resin having a silanol group content of 1.0% by weight (trade name SH805, manufactured by Toray Dow Corning Silicone Co., Ltd.) is used. ) Was used.

Then, in Example 1. The above components were applied to a cathode ray tube in the same manner as in.

Comparative Example 3. Methylphenyl polysiloxane resin (same as that of Example 2) ...... 30 parts Methyltrimethoxysilane ...... 20 parts Dibutyltin diacetate ...... 0.5 parts Normal hexane ...... 50 parts Red coloring material ...... 0.5 Part and Example 1. The above components were applied to a cathode ray tube in the same manner as in.

Comparative Example 4. Methylphenylpolysiloxane resin (same as that of Example 2) ...... 30 parts Methyl-tris (methylethylketoxime) silane ...... 20 parts Dibutyltin diacetate ...... 10 parts Normal hexane ...... 50 parts Red coloring material ...... 0.5 Part and Example 1. The above components were applied to a cathode ray tube in the same manner as in.

Comparative Example (Conventional Example) 5. Methylphenyl polysiloxane resin (the same as in Example 2) ...... 30 parts Methyltrimethoxysilane ...... 10 parts Normal propyl orthosilicate ...... 10 parts Dibutyltin diacetate ...... 0.5 parts Normal hexane ...... 50 parts Red coloring material: 0.5 part Then, in the same manner as in Example 1, the above components were applied to a cathode ray tube.

FIG. 3 shows the results of a test of the electric insulation property and the solvent reproducibility of the cathode ray tube having the insulating coating film formed as described above. The electrical insulation property was evaluated by leaving a wet cloth on the insulating coating film for 24 hours, applying a voltage of 35 kv to the anode cap of the cathode ray tube, and measuring the induced voltage around the anode cap at that time. .
The solvent regeneration was evaluated by whether or not the coating film could be removed by wiping the cloth with acetone one month after the coating film was formed.

In the case of methylpolysiloxane resin, Comparative Example 1 using an alkoxysilane as a cross-linking agent had good electrical insulation, but was unable to regenerate the solvent. Comparative Example 2 using oxime silane as the cross-linking agent was able to regenerate the solvent, but had poor electrical insulation.

On the other hand, the electric insulation of Example 1 was almost the same as that of Comparative Example 1, and the solvent regeneration was also possible. In the case of the methylphenylpolysiloxane resin shown in Example 2, the same effect as that of the methylpolysiloxane resin could be confirmed.

In addition, FIG. 4 shows the results of examining the state of electrical insulation and solvent regeneration in the composition of Example 1 while changing the mixing ratio of alkoxysilane and oxime silane. The effect was confirmed in the compounding ratio of the alkoxysilane and the oxime silane in the range of 1:10 to 10: 1. Among them, the mixing ratio of 1: 2 to 2: 1 was suitable.

As is clear from the insulating coating materials according to the above examples, by mixing the alkoxysilane and the oxime silane as the cross-linking agent, the solvent regeneration can be improved while the electric insulation is improved. Was confirmed.

Therefore, by using an alkoxysilane and an oxime silane as a cross-linking agent, it is possible to regenerate the solvent while maintaining high electric insulation.

By using such an insulating coating material as an insulating coating film for a cathode ray tube, the mass productivity is excellent.

In the present embodiment, the insulating coating material is applied to the cathode ray tube, but the present invention is not limited to this cathode ray tube, and is applied to those which retain high insulation and require solvent regeneration. It goes without saying that you can do it.

[0051]

As is apparent from the above description,
According to the insulating coating material of the present invention, it is possible to obtain a material excellent in solvent regeneration even though it has high electric insulation.

Further, according to the cathode ray tube of the present invention, in the insulating coating film formed around the acceleration electrode terminal portion on the outer wall of the funnel portion valve, the insulating property is improved and the solvent can be easily regenerated. Like

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a cathode ray tube according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an explanatory view showing an effect of the cathode ray tube according to the present invention.

FIG. 4 is an explanatory diagram showing an effect of the cathode ray tube according to the present invention.

[Explanation of symbols]

 1 Cathode ray tube 5 Anode cap 6 Insulating coating

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimasa Ishigaki, 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd. (72) Inventor Yasuhiko Uehara 3300, Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Division ( 72) Inventor Shigemi Hirasawa 3300, Hayano, Mobara-shi, Chiba Electronic device division, Hitachi, Ltd. (72) Instructor Shoji Akamatsu 2-2 Chikigan coast, Ichihara, Chiba Toray Dow Corning Silicone Co., Ltd.

Claims (3)

[Claims] 1. An insulating coating material containing at least the following materials (A) to (C): (A) Polysiloxane resin having a condensation-reactive group. (B) An alkoxysilane having the general formula RmSiX4-m (R is a monovalent hydrocarbon group and X is an alkoxy group, where m is an integer of 1 or 2.). (C) General formula RnSiZ4-n (R is a monovalent hydrocarbon group, Z is an oxime group, where n is 1 or 2
Is an integer. ) Consisting of oxime silane. 2. The insulating coating material according to claim 1, wherein the alkoxysilane and the oxime silane are mixed in a mixing ratio of 1:10 to 10: 1. 3. A cathode ray tube, wherein the insulating coating material according to claim 1 or 2 is used as an insulating coating film formed around the acceleration electrode terminal portion on the outer wall of the funnel portion valve.