JP2863390B2 - Convergence correction magnetic sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CTV and a CRT-D.
The present invention relates to a convergence correction magnetic sheet for correcting a color shift of an image caused by non-uniformity of a magnetic path of a deflection yoke portion.

[0002]

2. Description of the Related Art Conventionally, magnetic circuit distortion due to non-uniformity of a magnetic path of a deflection yoke portion of a CTV and a general-purpose CRT-D causes disturbance in vertical and horizontal deflection characteristics, and causes color between a central portion and an end portion of an image. It appears as a shift or distortion phenomenon. Conventionally, as a material for correcting such color shift or distortion, a sheet made of a composite material in which a soft vinyl chloride resin and a ferrite powder are combined has been used.

[0003]

In recent years, the temperature inside a device has been increasing as the definition of a CRT-D is increased, the frequency is increased, and the angle of the CTV is increased. As a result, the convergence correction magnetic sheet has been required to have higher heat resistance than before. Specifically, the temperature has increased from the conventional heat resistance of 80 ° C to 100 ° C to 110 ° C to 120 ° C. In order to meet such a requirement for heat resistance, heat resistance of a soft vinyl chloride resin has been insufficient. Therefore, heat-resistant synthetic resins have been conventionally proposed. Specifically, polyamide, polypropylene, polyphenylene sulfide, polymethylpentene and the like have been proposed. However,
When these resins are used, since they are not flexible, it is difficult to mount them on the deflection yoke, and a flexible material is required. The present invention has been made to solve the above-mentioned problems of the prior art, and has two kinds of chlorosulfonated polyethylenes having different chlorine ratios and Mooney viscosities in a compound and a volume resistivity of 10 ⁴ Ω-cm or more. By mixing ferrite powder, metal oxide, flame retardant, and vulcanization accelerator, and processing into a sheet having a thickness of 0.2 to 0.7 mm, it has heat resistance of 110 ° C to 120 ° C, and An object of the present invention is to provide a flexible convergence correction magnetic sheet.

[0004]

According to the present invention, 100 parts by weight of a total of two chlorosulfonated polyethylenes having different chlorine ratios and Mooney viscosities in a compound, and a volume resistivity at room temperature of 10 ⁴ Ω-cm. 900 to 1100 parts of the above ferrite powder, 50 to 100 parts of a metal oxide, a flame retardant, and a vulcanization accelerator are blended, and 0.2 to 0.
By processing into a sheet having a thickness of 7 mm, a convergence correction magnetic sheet having flexibility and a heat-resistant temperature of 120 ° C. is provided.

[0005] Chlorosulfonated polyethylenes are commercially available in which the proportion (% by weight) of chlorine in the compound is 23% to 43%, but the physical properties and processability vary depending on the proportion of chlorine. The desired characteristics of the present invention cannot be exhibited. That is, those having a small amount of chlorine have good heat resistance, but have too low Mooney viscosity and lack workability. Conversely, those with a large amount of chlorine have high Mooney viscosity and good workability, but have poor heat resistance. Therefore, in order to improve heat resistance, a material having a small amount of chlorine is desirable. However, when a material having a small amount of chlorine is rolled into a sheet having a thickness of 0.2 to 0.7 mm, The material inside adheres to the rolling rolls, or the sheet is cut during the rolling, which is not preferable in processing. However, when the chlorosulfonated polyethylene having a low chlorine content and a low Mooney viscosity and the chlorosulfonated polyethylene having a high chlorine content and a high Mooney viscosity are combined according to the present invention, a composition having a good balance between heat resistance and workability can be obtained. I can do it. The percentages (% by weight) of the chlorine content of the two chlorosulfonated polyethylenes having different chlorine contents to be combined are those of 23% to 27% and those of 34 to 38%, and the former has a Mooney viscosity of 3%.
0-45, the latter being 90-105. The blending ratio of the chlorosulfonated polyethylene having a low chlorination rate and the chlorosulfonated polyethylene having a high chlorination rate is 8: 2.
~ 3: 7. If the ratio of the chlorosulfonated polyethylene having a low chlorination ratio is 8 or more, processing into a sheet becomes impossible. When the ratio is 3 or less, the heat resistance is significantly reduced.

[0006] Ferrite powder is necessary for the convergence correction magnetic sheet to secure magnetic characteristics (permeability near 1 KHz). Generally, a magnetic permeability of 8 or more is required, and in order to secure this, it is desirable to mix 900 parts or more with 100 parts of chlorosulfonated polyethylene. If the amount is less than this, it is difficult to secure a magnetic permeability of 8 or more. On the other hand, by increasing the compounding amount of ferrite, a large magnetic permeability can be obtained. However, when 1100 parts or more are added, the rubber elasticity of the chlorosulfonated polyethylene is lost, and the flexibility and strength are lost, and the compound of the compound is lost. Since the elongation disappears, rolling becomes impossible. Therefore, the ferrite content is 90%.
0 to 1100 parts is suitable.

Further, the convergence correction ferrite sheet is required to have a high insulation resistance because it is mounted on a high-pressure portion near the deflection yoke core. Specifically, 10
A volume resistivity of ⁹ Ω-cm or more is required. Although the insulation resistance of the composite material greatly depends on the insulation resistance of the base material, when the filler (ferrite) is mixed 9 to 11 times with respect to the base material as in this patent, the insulation resistance of the filler (ferrite) is reduced. Influence becomes large. Therefore, 10 ⁹ Ω-cm
In order to obtain the above volume resistivity, it is necessary to use ferrite having a high volume resistivity. Specifically, 10 ⁴ Ω
A volume resistivity of −9 cm or more is required, and when a ferrite smaller than this is used, a volume resistivity of 10 ⁹ Ω-cm or more cannot be obtained. Ferrites having a volume resistivity of 10 ⁴ Ω-cm or more include Mn—Mg—Zn ferrites, Ni—Zn ferrites, Cu—Zn ferrites, Cu—Ni—Zn ferrites, and composite ferrites of these ferrites. There is. As a vulcanization system for vulcanizing the chlorosulfonated polyethylene, a combination of a metal oxide and a vulcanization accelerator is preferable in consideration of heat resistance. Metal oxides include magnesium oxide and litharge. Examples of the vulcanization accelerator include DM (dibenzothiazyl disulfide), TT (tetramethylthiuram disulfide), and T
RA (dipentamethylenethiuram tetrasulfide),
There is TET (tetraethylthiuram disulfide).
These can be used in combination of two or more.

[0008]

The convergence-corrected magnetic sheet having flexibility and heat resistance can be obtained because the base material is a flexible rubber called chlorosulfonated polyethylene. or,
By combining two types of chlorosulfonated polyethylenes having different chlorine ratios and Mooney viscosities in the compound, a mixture excellent in processability can be obtained, and a sheet having a thickness of 0.2 to 0.7 mm can be stably produced. It becomes possible. By selecting a material having a volume resistivity of 10 ⁴ Ω-cm or more as a ferrite, a convergence correction magnetic sheet having a volume resistivity of 10 ⁹ Ω-cm or more can be obtained.

[0009]

The present invention will be described in more detail with reference to the following examples. The physical properties in Examples and Comparative Examples were measured by the following methods. Heat resistance test is 120 ° C x 500
Elongation change after heating in a constant temperature bath under the conditions of time: in accordance with JIS K6301. Hardness: Based on JIS K6301. Chlorosulfonated polyethylene has two kinds of chlorine content 25%, Mooney viscosity (ML _{1 + 4} 100 ° C.) 39 and chlorine content 35%, Mooney viscosity (ML _{1 + 4} 100 ° C.) 95: 6: 4.
At a weight ratio of Ferrite has a volume resistivity of 10 ⁷
Mn-Mg-Zn ferrite powder of Ω-cm (average particle diameter 5 μm) was used and blended at a ratio of 1000 parts to 100 parts of chlorosulfonated polyethylene.

A metal oxide, a flame retardant, and a vulcanization accelerator were blended in the following proportions to 100 parts of chlorosulfonated polyethylene. Metal oxide Magnesium oxide 11 parts Lisage 22 parts Vulcanization accelerator DM 1.2 parts TRA 2.2 parts Flame retardant chlorinated paraffin 30 parts This composition was rolled into a 0.4 mm thick sheet with a rolling roll. At 120 ° C.

[0011]

[Table 1] This result has a much smaller rate of change than the comparative example described later.

Comparative Example Vinyl chloride resin (average degree of polymerization: 1300) 14 parts Plasticizer DOP (di-2-ethylenehexyl phthalate) 8 parts Stabilizer TOP (tri-2-ethylhexyl phosphite) 2 parts Flame retardant chlorinated paraffin 130 parts of a Mn-Mg-Zn ferrite powder (average particle size: 5 µm) was added to 5 parts of the resin, and the mixture was heated and kneaded with a Banbury mixer, and then rolled into a sheet having a thickness of 0.4 mm.

[0013]

[Table 2] In the conventional vinyl chloride convergence magnetic sheet, the change in physical properties at 120 ° C. is much larger than that of the embodiment of the present invention.

Continuing from the front page (72) Inventor Toshiki Sasaki 1-1-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Yuichi Ozaki 6-12-8 Ueno, Iwatsuki-shi, Saitama Fujikura Rubber Industries Co., Ltd. (72) Inventor Fumio Akaishi 6-12-8 Ueno, Iwatsuki-shi, Saitama Fujikura Rubber Industry Co., Ltd. Iwatsuki Factory (56) References JP-A-4-290413 (JP, A) JP-A-6 -13002 (JP, A) JP-A-4-288802 (JP, A) JP-A-3-19247 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01J 29/46- 29/86 H01F 1/00-1/44

Claims (4)

(57) [Claims] 1. A ferrite powder having 100 parts by weight in total of (A) two kinds of chlorosulfonated polyethylenes having different chlorine ratios and Mooney viscosities in a compound, and (B) a volume resistivity at room temperature of 10 ⁴ Ω-cm or more. 900-1
100 parts, and (C) 50 to 100 parts of a metal oxide, a flame retardant, and a vulcanization accelerator, and processed into a sheet having a thickness of 0.2 to 0.7 mm, wherein the convergence correction magnetism is provided. Sheet. 2. The convergence correction magnetic sheet according to claim 1, wherein the two chlorosulfonated polyethylenes have a chlorination rate of 23 to 27% and 34 to 38%, respectively. 3. The two chlorosulfonated polyethylenes having Mooney viscosities of 30 to 45 and 90 to 10, respectively.
The convergence correction magnetic sheet according to claim 1, wherein the number is 5. 4. The convergence correction according to claim 2, wherein the blending ratio of the chlorosulfonated polyethylene having a low chlorination rate and the chlorosulfonated polyethylene having a high chlorination rate is 8: 2 to 3: 7. Magnetic sheet.