JPH0613002A - Sheet for magnetic field correction of deflection yoke - Google Patents

Abstract

PURPOSE:To exhibit the highly heat resistant life and good flexibility, and to effectively achieve the magnetic field correction effect by dispersively adding specific wt.% of soft ferrite powder together with a softening reformation agent to chlorosulfonated polyethylene containing specific percentage of chlorine. CONSTITUTION:A sheet body 6 is molded out of a composition, for which 70-85wt.% of soft ferrite powder such as magnesium ferrite is dispersively added to chlorosulfonated polyethylene containing chlorine of less than 30wt.% as indicated by a formula, together with a softening reformation agent of 5-30 parts relative to 100 parts of the main agent. The composition has the highly heat resistant life, and is very flexible and can be easily deformed. Even when it is used for a deflection yoke of the type for which a coil 5 is embedded between protruded walls 2, the sheet 6 for magnetic field correction is pushed into contact with the surface of the coil 5 situated on the bottom part of a groove part 4, to effectively achieve the magnetic field correction effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet body used for correcting a magnetic field of a deflection yoke, and more specifically, it has excellent heat resistance and excellent flexibility, and is attached to a winding surface. Suitable for use in deflection yokes that require extreme bending or deformation of the sheet body.For example, a large number of raised walls for heat dissipation are arranged side by side on an insulating frame, and windings are provided between these raised walls. The present invention relates to a magnetic field correction sheet suitable for use in a buried type deflection yoke.

[0002]

2. Description of the Related Art A deflection yoke mounted on a cathode ray tube used for a television, a CRT display or the like uses a magnetic field correcting sheet for the purpose of finely adjusting the magnetic field. 4 and 5 show this state. In the deflection yoke A configured by arranging the winding b on the inner and outer surfaces of a trumpet-shaped synthetic resin insulating frame a having a flat curved inner surface, the winding b
The sheet body 1 is attached to the surface of the sheet. The sheet body 1 is a magnetic material-containing resin sheet obtained by molding a composition in which soft ferrite powder is dispersed and mixed in a synthetic resin, and the sheet body 1 extends along the surface of the winding b by the adhesive applied to the back surface. It has been pasted.

Since such a sheet body 1 is adhered to the surface of the winding b arranged on the curved inner surface of the deflection yoke A,
Need flexibility. In order to meet such demands,
Conventionally, magnetic field correction sheets using vinyl chloride as a binder have been widely used. However, in recent years, the heat generation amount of the deflection yoke tends to increase as the size of the TV receiver increases and the definition thereof becomes high. To cope with such a tendency, the magnetic field correction sheet is also required to have a high heat resistance life. Is starting to appear. For example, a material capable of exhibiting a heat-resistant life of 100,000 hours or more under a temperature environment of 110 ° C. or more, or 40,000 hours or more under a temperature environment of 120 ° C. is required. Vinyl chloride has poor heat resistance, and when it is exposed to a high temperature environment for a long time, highly toxic chlorine gas is generated, and as a result of the progress of dechlorination, the quality deteriorates and cracks occur or the insulation property is deteriorated. Because there is a problem that decreases
It cannot be used as a binder for such applications.

On the other hand, high heat resistant resins such as polymethylpentene, nylon, polyethylene terephthalate, epoxy resin and polyphenylene sulfide are known as binders having a high heat resistance life, but these are poor in flexibility and are curved inner surfaces of the deflection yoke. Not suitable for sticking to. Therefore, it is possible for the present inventor to add a small amount of a softening agent to these high heat resistant resins or to mix them with other resins in order to exert some flexibility while using these high heat resistant resins as a binder. It has already been proposed and has achieved certain results with respect to the deflection yoke having the above-mentioned shape.

[0005]

Recently, the size and the quality of TV receivers have been further increased, and the deflection yoke tends to be higher in temperature. In response to this, a new type of deflection yoke has been developed. Is being done. As shown in FIG. 6, this type of deflection yoke uses a trumpet-shaped insulating frame 3 made of synthetic resin in which a large number of fin-shaped raised walls 2, 2 ... As shown in FIG. 7, the groove portion 4 formed between the raised walls 2 and 2 in the insulating frame 3 made of synthetic resin.
This is a configuration in which the winding 5 is disposed on the. The heat generated by the winding 5 is radiated through the raised wall 2.

Adhesion of the magnetic field correction sheet to the winding 5 in the deflection yoke of this type is shown in FIGS.
When it is carried out in the groove along the longitudinal direction of the groove as shown in Fig. 9, although it can be directly attached to the surface of the winding 5, for example, as shown in Figs. In the case of sticking across the sheet, a gap d is formed between the sheet body 1 and the winding wire 5, so that there is a problem that the magnetic field correction effect cannot be effectively exhibited. The conventional sheet body 1 in which a softening agent or the like is added to the high heat resistant resin so as to have flexibility has flexibility (deformability) to such an extent that it can be attached to a flat curved inner surface, but between the raised walls. It is not flexible to the extent that it can be positioned deep inside the groove 4, and if it is forced into between the raised walls 2 and 2, for example, a crack will occur at the portion indicated by K in the figure, and it will be used as a magnetic field correction sheet. Is impossible.

The present invention has been made in view of the above situation, and has a high heat resistance life and is extremely excellent in flexibility, and is used for a deflection yoke of a type in which a winding is embedded between raised walls. Even in such a case, it is possible to position the sheet body deeply in the groove portion between the raised walls to bring the sheet body into contact with the winding surface, and to provide a magnetic field correction sheet that can effectively exert the magnetic field correction effect.

[0008]

As a result of intensive studies, the inventors of the present invention have used chlorosulphonated polyethylene having a chlorine content of less than 30% by weight as a binder, and the soft ferrite powder 70 is added to the chlorosulphonated polyethylene. It has been found that the above problems can be solved by preparing a magnetic field correction sheet with a composition in which about 85 wt% is dispersed and blended with a softening modifier. The mechanical and thermal properties of the magnetic field correction sheet prepared by using the above composition have a breaking strength at room temperature of 40 Kgf / cm ² or less, a breaking elongation of 100% or more, and 110 It has been found that it is more preferable to have a heat resistance life of 100,000 hours or more under a temperature environment of ° C or 40,000 hours or more under a temperature environment of 120 ° C.

[0009]

The sheet body is used by adhering the sheet body so that the sheet body directly contacts the winding surface provided in the groove between the raised walls of the insulating frame. The sheet body arranged transversely between the raised walls is pushed into the groove portion with a fingertip or an appropriate jig,
The sheet body is positioned on the winding surface by bringing the adhesive on the lower surface of the sheet body into contact with the winding surface. Since this sheet body has a small breaking strength, it is extremely flexible and easily deformable, and can be easily pushed into the groove portion between the raised walls. Moreover, since the deformation is plastic deformation, the shape after the deformation is maintained and the magnetic field correction effect is exerted for a long period of time. Since the elongation at break is large, cracks will not occur even if the above pushing operation is performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows an embodiment of the magnetic field correcting sheet of the present invention, and FIG. 2 shows a state in which the magnetic field correcting sheet of the embodiment is attached to the surface of the winding wire provided on the inner surface of the deflection yoke. The magnetic field correction sheet is a sheet body 6 made of resin containing a magnetic material.
It has a structure in which the pressure-sensitive adhesive layer 6a is laminated on the back surface of. Although the illustrated example shows a single sheet body, a large number of sheet bodies 6 are normally supplied on a large-sized release paper in a state in which they are arranged vertically and horizontally through a groove portion for breaking.

The sheet body 6 is formed by a composition in which 70 to 85% by weight of soft ferrite powder is dispersed and blended together with a softening modifier in chlorosulfonated polyethylene having a chlorine content of less than 30% by weight. As the soft ferrite, known soft ferrites such as magnesium ferrite, nickel zinc ferrite and manganese zinc ferrite can be used. If the content of the soft ferrite powder is less than 70% by weight, the required magnetic properties cannot be obtained, and if it exceeds 85% by weight, it becomes difficult to mold or becomes brittle due to lack of flexibility. The blending amount of the powder is set in the range of 70 to 85% by weight based on the whole. As the softening modifier, conventionally known ones can be used, and the addition amount thereof is preferably 5 to 30 parts based on 100 parts of chlorosulfonated polyethylene.

Chlorosulfonated polyethylene is a special synthetic rubber obtained by chlorinating and chlorosulfoning polyethylene using chlorine and sulfurous acid gas.
It has the structural formula shown by.

[Chemical 1] As the chlorosulfonated polyethylene currently on the market, JIS. Breaking strength according to "Plastic tensile test method" of K7113 is 120 to 350 Kgf / cm
There are many grades in the range of about ² and the elongation at break of about 300 to 500%, but in this example, TOSO-CSM TS-320 (manufactured by Tosoh Corporation) having a chlorine content of 25% by weight was used. . This chlorosulphonated polyethylene has a breaking strength of 272 Kgf / cm ² and 48
It has a breaking elongation of 0%, and by using this grade of chlorosulphonated polyethylene, the properties after blending with soft ferrite powder have a breaking strength at room temperature of 40 Kgf / cm ² or less and a breaking elongation. Is 100
%, And a heat-resistant life of 100,000 hours or more under a temperature environment of 110 ° C. or 40,000 hours or more under a temperature environment of 120 ° C. can be exhibited.

The breaking strength is set to 40 Kgf / cm ² or less because if it exceeds 40 Kgf / cm ² , the flexibility of the sheet becomes insufficient and it becomes difficult to push the sheet body 6 into the groove portion 4 between the raised walls. This is because even if it is pushed in, it is restored to its original shape by the rubber elastic force, so that the positioning state in the groove 4 cannot be maintained. Further, the breaking elongation is set to 100% or more because at least 50% or more breaking elongation is required in order to deform the sheet body 6 in a wavy shape along the raised wall 2 and the groove portion 4. It is based on the judgment that a breaking elongation of 100% or more is required in order to quickly respond to the above.

Further, the heat resistant life of 100,000 hours or more in the temperature environment of 110 ° C. or 40,000 hours or more in the temperature environment of 120 ° C. is realized because this value is large TV or high definition TV,
Alternatively, it is a standard value required for a magnetic field correction sheet used for a high heat generation deflection yoke for a CRT display or the like, no crack is generated even when exposed to such a temperature environment, and insulation (volume resistivity) This is because it is required that there is no decrease of 10 ⁷ Ω · cm or more). A magnetic field correction sheet prepared by molding a composition in which 70 to 85% by weight of soft ferrite powder is dispersed and blended together with a softening modifier in chlorosulfonated polyethylene having a chlorine content of less than 30% by weight is at room temperature. In addition to having sufficient heat resistance, it also has self-extinguishing property, and since the chlorine content is less than 30%, the dechlorination phenomenon when exposed to a high temperature environment is also slight. Therefore, there are few problems of toxicity, there is no problem of quality deterioration due to the dechlorination phenomenon, and there is no crack or deterioration of insulating property, and the function as a magnetic field correction sheet can be exerted for a long time.

Details of the state in which the magnetic field correcting sheet of the present invention is attached to the deflection yoke are shown in FIG. The sheet body 6 may be attached along the longitudinal direction (depth direction in the drawing) of the groove portion 4, but the attaching position and the attaching direction of the sheet body 6 are not determined, and the free position is determined according to the magnetic field correction content. It is necessary to attach to the raised walls 2, 2 as shown in the figure.
It is very often pasted in a state of crossing.
Since the magnetic field correction sheet of the present invention is excellent in flexibility and elongation, it can be freely deformed along the raised wall 2 as shown in the figure, and therefore the sheet body 6 can be formed by using a fingertip or an appropriate jig. It is possible to bring the pressure-sensitive adhesive layer on the lower surface of the sheet body into contact with the surface of the winding 5 by pushing the sheet into the groove 4 between the raised walls 2 and 2, and the sheet body 6 can be positioned on the surface of the winding 5. . Moreover, since the breaking strength of the sheet body is small and the rubber elastic force is suppressed, the shape after deformation is maintained. Further, since the breaking elongation is large, cracks do not occur in the portion indicated by K in the figure where stress is likely to concentrate. The sheet for magnetic field correction is also excellent in heat resistance and does not cause insulation deterioration even when exposed to a high temperature environment for a long period of time.

[0016]

In the magnetic field correcting sheet of the deflection yoke of the present invention, 70 to 85% by weight of soft ferrite powder is dispersed and blended with a softening modifier in chlorosulfonated polyethylene having a chlorine content of less than 30% by weight. Since it is prepared using the composition, it is possible to obtain a magnetic field correction sheet which is extremely soft and easy to stretch. Therefore, it can be applied to a deflection yoke of a type in which a winding is disposed in the groove between the raised walls, and the sheet body is deformed along the raised wall to bring the sheet body into contact with the winding surface. The magnetic field correction effect can be effectively exerted. Since the magnetic field correction sheet has an excellent heat-resistant life, it does not cause cracks or deteriorate the insulating property even when it is exposed to a high temperature environment for a long time.

[Brief description of drawings]

FIG. 1 is a perspective view showing one embodiment of a magnetic field correction sheet of the present invention.

FIG. 2 is a schematic perspective view of essential parts showing a state in which the magnetic field correcting sheet of the embodiment is stuck in a groove between raised walls on the inner surface of the deflection yoke in a pressed state.

FIG. 3 is a schematic cross-sectional view of a main part showing a state in which a magnetic field correction sheet is stuck in a groove between raised walls on an inner surface of a deflection yoke in a pressed state.

FIG. 4 is a perspective view showing an appearance of a conventional deflection yoke and a state in which a magnetic field correction sheet is attached to the inner surface of the deflection yoke.

FIG. 5 is a front view showing a state in which a magnetic field correction sheet is attached to the inner surface of a conventional deflection yoke.

FIG. 6 is a simplified front view showing the appearance of an insulating frame having a raised wall for heat dissipation.

FIG. 7 is a perspective view of a main part showing a heat dissipation protruding wall of the deflection yoke and a winding disposed between the protruding walls.

FIG. 8 shows a state in which a conventional magnetic field correction sheet is attached to the surface of the winding wire provided in the groove portion between the raised walls of the deflection yoke along the longitudinal direction of the groove portion. Illustration,
(B) is a cross-sectional explanatory view of the main part

9A and 9B show a state in which a conventional magnetic field correction sheet is transversely attached between the raised walls of the deflection yoke, FIG. 9A is a plan view of a main part, and FIG. 9B is a cross-sectional view of a main part.

[Explanation of symbols]

 A deflection yoke a synthetic resin insulation frame b winding 1 sheet body 2 raised wall 3 synthetic resin insulation frame 4 groove 5 winding 6 sheet body 6a adhesive layer

Claims (2)

[Claims] 1. Chlorosulfonated polyethylene having a chlorine content of less than 30% by weight and soft ferrite powder 70.
A magnetic field correction sheet for a deflection yoke, which is produced by using a composition in which about 85 wt% is dispersed and blended with a softening modifier. 2. The breaking strength at room temperature is 40 kgf /
cm ² or less, breaking elongation of 100% or more, and 1
More than 100,000 hours or 120 ° C in a temperature environment of 10 ° C
2. The magnetic field correcting sheet for a deflection yoke according to claim 1, wherein the sheet has a heat-resistant life of 40,000 hours or more under the above temperature environment.