JPH05335127A - Bonded magnet and electron beam adjusting device using the same - Google Patents

Abstract

PURPOSE:To provide a bonded magnet capable of low magnetic force- magnetization in the least and even dispersion of magnetized amount having the excellent fire resistance as well as the electron beam adjusting device using the bonded magnet for the raw material of an adjusting magnet. CONSTITUTION:Within the bonded magnet comprising magnetic particles, inorganic filler and fire resistant resin compound, the content of magnetic particles as a functional raw material is restricted to the low level of 10-40wt% while that of one kind or multiple kinds of the compounds selected from iron oxide, Al2O3, SiO2, CaCO3 as for the inorganic filler to be added for enhancing the incombustibility and rigidity is specified as 30-60wt%. Accordingly, the flux density (G) will not be affected by the fluctuation in the charge voltage (V).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bond magnet having a small variation in the amount of magnetization with respect to a low magnetic force and excellent in flame retardancy, and a color picture tube or a CRT display picture tube using the bond magnet. The present invention relates to an electron beam adjusting device mounted on a neck portion.

[0002]

2. Description of the Related Art Three electron beams emitted from an in-line integrated electron gun sealed at the neck of a cathode ray tube are designed to concentrate at one point of the fluorescent surface coated on the front surface of the cathode ray tube. The electron beam is deflected by the deflection yoke in order to collide the electron beam with the entire fluorescent surface.
The electron beams of the book are made to collide with the corresponding fluorescent picture elements. However, in reality, three electron beams are not concentrated at one point on the fluorescent surface due to variations in manufacturing of the electron gun and the deviation between the electron gun and the tube axis, and the electron beams corresponding to the respective electron beams. There is a case where the correspondence with the photo-picture element is broken and the beams collide with each other, and as a result, the convergence characteristic and the purity characteristic may be deteriorated.

In order to correct these variations, FIG.
A so-called electron beam adjusting device A having a pair of a two-pole magnet 1 for purity adjustment, a four-pole magnet 2 for convergence adjustment and a six-pole magnet 3 for convergence adjustment is mounted on the cathode ray tube neck B as shown in FIG. Then, the deviation amount is corrected.

However, in such an electron beam adjusting apparatus, the arrangement of the three electron beams is forcibly corrected during the adjustment of the convergence adjusting quadrupole magnet, so that the arrangement of the electron beams is twisted. is there. When such three twisted electron beams are deflected in the horizontal direction of the screen by the deflection yoke, a phenomenon called beam rotation in which both side beams of the electron gun are separated at both ends in the horizontal direction of the screen occurs. In order to correct this beam rotation, as shown in FIG. 4, separately from the convergence adjustment quadrupole magnet 2, a second
The pair of 4-pole magnets 4 are provided at the rear position of the deflection yoke part.

[0005]

By the way, the beam rotation correction effect is obtained between the convergence adjustment 4-pole magnet 2 which is the first 4-pole magnet and the beam rotation correction 4-pole magnet 4 which is the second 4-pole magnet. It is almost proportional to the distance L and the amount of magnetization of both quadrupole magnets. If the amount of magnetization is large, there is a drawback that it will react sensitively to slight impacts and slight changes in environmental conditions, and the convergence after adjustment will shift. Therefore, the separation distance should be increased as much as possible, and the beam rotation correction 4
The magnetizing amount of the polar magnet 4 is reduced.

Also in the conventional electron beam adjusting apparatus, a two-pole magnet for purity adjustment, a four-pole magnet for convergence adjustment, and a six-pole magnet for convergence adjustment.
When the action of the pole magnet is observed in detail, it can be seen that the beam movement amount by the two pole magnet is several times that of the four and six pole magnets. Since the amount of beam movement is proportional to the magnetizing amount of the magnet, it is sufficient and preferable that the magnetizing amount of the 4- and 6-pole magnets is lower than the magnetizing amount of the 2-pole magnet. It can be seen that it is.

However, the materials of the respective magnets used in the conventional electron beam adjusting apparatus are all formed by the bond magnet having the composition corresponding to the two-pole magnet which is required to have a high magnetic force. Fifty
All the magnets were formed with a composition having a content as high as -80% by weight.

However, in such a bond magnet having a high magnetic powder content, when there is a variation in the magnetizing voltage, the variation is likely to be reflected as a variation in the magnetizing amount, and the magnetizing amount can be controlled to a low level. It is difficult, and there is a problem that misconvergence is likely to occur due to variations in magnetization. And such misconvergence becomes a fatal defect for a picture tube in which high definition is particularly required.

In order to make up for these drawbacks, it is conceivable to adjust the magnetic powder content to a low content of about 10 to 40% by weight. As a result, the flame retardancy is inferior. Since the magnet for electron beam adjustment is adjacent to the high voltage part, it is indispensable to satisfy the flame resistance according to the UL standard. However, when the resin content increases, the flame resistance decreases and the UL standard is reduced. Therefore, the UL standard cannot be satisfied simply by suppressing the magnetic powder content.

That is, when the blending amount of the resin is increased, the flame retardancy of the blending is remarkably lowered. Especially, when a thin-walled molded product of about 1.0 mm corresponding to the thickness of the adjusting magnet is prepared with this bond magnet, The product has a higher ignition amount than the compounded product having a high magnetic powder content, and this molded product was used to test for the presence or absence of ignition of cotton due to dropping substances during combustion, which is a test on the UL standard. In this case, the possibility of ignition of cotton is extremely large and dangerous, and the rank in the UL standard is poor.

In addition to the flame retardance, such a bonded magnet has a large amount of resin, which causes a large shrinkage rate after molding, and a conventional mold for producing a high content compounded product. There is also a problem that can not be used.

The present invention has improved the above-mentioned drawbacks of the prior art, provided a bond magnet which is capable of uniformly magnetizing with a low magnetic force with little variation in the amount of magnetization, and is excellent in flame retardance. An object of the present invention is to provide an electron beam adjusting device used as a material for an adjusting magnet.

[0013]

The first object of the present invention is to provide a bond magnet having a low magnetic powder content and a flame-retardant measure, instead of a conventional bond magnet having a high magnetic powder content. It is intended to provide a bond magnet capable of preventing ignition of cotton due to dripping during burning, which is a "flammability test" in UL standard even if the magnetization is low, and which has little variation in magnetization. The composition is composed of magnetic powder, an inorganic filler, and a flame-retardant resin composition, and the content of the magnetic powder, which is a functional material, is set to a low content of 10 to 40% by weight to improve incombustibility and rigidity. The content of one or more kinds selected from iron oxide (FeO), alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcium carbonate (CaCO ₃ ) as an inorganic filler to be added for the purpose of 30 to 60 weight It is characterized in that without a.

In a second aspect of the present invention, in the bond magnet having the above-mentioned structure, ferrite magnetic powder is used as the magnetic powder, iron oxide (FeO) is used as the inorganic filler, and 100 parts by weight of the resin binder as the flame-retardant resin composition and halogen. 30 to 60 parts by weight of an organic flame retardant containing 15 to 30 parts by weight of antimony trioxide and 5 to 15 parts by weight of zinc borate.

A third aspect of the present invention is characterized in that the magnetic powder of the bond magnet is replaced with ferrite magnetic powder and alnico metallic magnetic powder is used.

A fourth aspect of the present invention is an electron beam adjusting apparatus using the bond magnet as a material for an adjusting magnet.

A fifth aspect of the present invention is an electron beam adjusting apparatus characterized by using the above-mentioned bond magnet as a material for a quadrupole magnet for beam rotation correction.

A sixth aspect of the present invention is an electron beam adjusting device for a color cathode ray tube, which comprises a pair of two convergence adjusting four-pole magnets, a convergence adjusting six-pole magnet and a purity adjusting two-pole magnet. 4 pole magnet for adjustment and /
Alternatively, in the electron beam adjusting device, the bond magnet is used as a material for the 6-pole magnet for convergence adjustment.

[0019]

EXAMPLES Next, details of the present invention will be described based on examples. The present invention comprises magnetic powder, an inorganic filler, and a flame-retardant resin composition, and the content of the magnetic powder, which is a functional material, is as low as 10 to 40% by weight to improve the nonflammability and rigidity. The content of the inorganic filler to be added for the purpose is 30 to 60.
It is said to be weight%.

As the magnetic powder, for example, ferrite magnetic powder or metallic magnetic powder can be used. As the metallic magnetic powder, AL-
NI-CO (Alnico) metal type, SM-CO type, FE-
CR-CO type magnetic powder and the like can be mentioned. Among them, the temperature coefficient,
The alnico metal-based magnetic powder is particularly preferable in terms of economy.

As the inorganic filler, iron oxide (FeO),
One or more selected from alumina (Al ₂ O ₃ ), silica (SiO ₂ ) and calcium carbonate (CaCO ₃ ) can be used.

As the flame-retardant resin composition, 30 to 60 parts by weight of an organic flame retardant containing halogen, 15 to 30 parts by weight of antimony trioxide, and 5 to 15 parts by weight of zinc borate are used per 100 parts by weight of a resin binder. A composition of parts can be used. The compounding ratio of the organic flame retardant is set to 30 to 60 parts by weight because when the amount is less than 30 parts by weight, the flame retardant effect is lost.
If it is more than 60 parts by weight, the flame resistance is satisfactory, but the bending strength of the magnet molded product becomes weak and becomes brittle. Further, since the flame retardant is generally more expensive than other resins, it is preferable to use the flame retardant in a necessary minimum amount.

As the resin binder of the flame-retardant resin composition used in the present invention, polyamide, polyolefin, polyphenylene sulfide and the like are preferable from the viewpoint of heat resistance and moldability. As the halogen-containing organic flame retardant, brominated polystyrene or the like is suitable. When the composition of the flame-retardant resin composition is out of the above range, it becomes difficult to obtain sufficient flame retardancy.

Magnetic powder and iron oxide or Al ₂ O ₃ , Si
The compounding ratio of O ₂ , CaCO ₃ and the flame-retardant resin composition needs to be within the above range. When the amount of magnetic powder and iron oxide exceeds the above range, moldability and toughness become insufficient, while when the amount decreases, the amount of resin compounded increases. Therefore, in the “flammability test” in UL standard, cotton caused by dripping during burning There is a risk of fire, and the rank of UL standard deteriorates, which is not preferable.

The above magnetic powder and iron oxide or Al
₂ O ₃ , SiO ₂ , CaCO ₃ and the flame-retardant resin composition are
The magnetic powder resin composition is obtained by mixing in the above proportions, kneading by heating, and pelletizing. If necessary, the magnetic powder may be surface-treated with a known silane coupling agent or the like before being mixed with the flame-retardant resin composition. The obtained magnetic powder resin composition is molded into a ring shape by a known molding method such as injection molding, and then the ring molded body is magnetized to a predetermined number of poles to form an adjusting magnet used in an electron beam adjusting apparatus. Become.

When the bond magnet of the present invention is used as an adjusting magnet of an electron beam adjusting device, its structure is different depending on the characteristics of each cathode ray tube, but in the electron beam adjusting device for a color cathode ray tube, it has two poles, four poles and six poles. In which the bond magnet of the present invention is used as the convergence purity adjusting magnet, or in the case of an electron beam adjusting apparatus having a 4-pole or 6-pole convergence magnet and a 2-pole purity magnet, 4-pole, 6-pole
An example is one in which the bond magnet of the present invention is used as the polar convergence magnet.

In the case of an electron beam adjusting device for a CRT display, in addition to the conventional electron beam adjusting device,
An example is one in which the bond magnet of the present invention is used as the quadrupole magnet for beam rotation correction.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but this does not limit the present invention in any way. Example 1 and Comparative Example 1 A quadrupole magnet for beam rotation was prepared using a low ferrite content bond compound set to 25% by weight of ferrite magnetic powder and 35% by weight of iron oxide. Further, Comparative Example 1 was a quadrupole magnet for beam rotation, which was produced using a high ferrite content bond compound containing 60% by weight of ferrite magnetic powder and containing no iron oxide.

Both Example 1 and Comparative Example 1 had a shape as shown in FIG. 1 (outer diameter 45 mm, inner diameter 33.5 mm, thickness 1.0 m).
m), and 1 mmφ for the magnet molded product
Using a magnetizing yoke having an iron core with a width of 8 mm and a capacitor power source having a capacity of 500 μF, which was wound 8 turns, the magnetization was performed while changing the charging voltage, and the change in the magnetic flux density with respect to the change in the charging voltage was measured. The results are shown in Figure 2.

FIG. 2 shows the relationship between the magnetic flux density and the magnetizing voltage dependence, and the values at 7.5 mm from the center of the magnet are plotted based on the measured values. The point marked "standard" on the vertical axis indicates the magnetic flux density required for each magnet, which is 1.5 G in the example shown in the figure. As is clear from the graph, in Comparative Example 1 in which the compound with a high ferrite content is used, the change in the magnetic flux density with respect to the change in the charging voltage in the low magnetic flux density region is extremely rapid. It can be seen that it is difficult to magnetize at a low level value like a 4-pole magnet. On the other hand, in Example 1 using the low ferrite content compound,
It can be seen that the change in the magnetic flux density with respect to the change in the charging voltage in the required magnetization region is extremely stable, and the predetermined magnetization can be performed in an extremely stable state.

Examples 2 to 10 and Comparative Examples 2 to 9 This example containing an inorganic filler while changing the magnetic powder content within the low content range of 10 to 40% by weight, and the inorganic filling. The comparative examples containing no wood were compared. For comparison, the composition of the iron oxide flame-retardant resin composition and the magnetic powder and iron oxide or A
A magnetic powder resin composition in which the mixing ratio of 1 ₂ O ₃ , SiO ₂ , CaC0 ₃ and the flame-retardant resin composition is changed as shown in Table 1 (however, for 100 parts by weight of polyamide resin, a hexamethylene bis stabilizer is used). 2 parts by weight was added, and 2% by weight of silane coupling agent was added to the magnetic powder), and a strip-shaped test piece with a thickness of 5 inches x 0.5 inches x 1.0 mm was formed by an injection molding machine. It was manufactured and subjected to a flame retardant test according to the vertical combustion test method of UL-94. The results are shown in Table 1.

[0032]

[Table 1]

As shown in Table 1, the magnet moldings of Comparative Examples 2 to 7 which did not contain the inorganic filler had cotton ignition due to the dripping material, and only UL94V-2 was evaluated in the UL standard. , 30-60 inorganic filler
The magnet moldings of Examples 2 to 10 containing wt.
There is no cotton ignition due to drips, and it is UL standard.
It is evaluated as 94V-0, and it is understood that it has extremely excellent flame retardancy. Further, as shown in Comparative Example 8, even when iron oxide is blended, if the blending ratio is 30% by weight or less, cotton ignited by the dropped product, and the effect of blending iron oxide does not appear. Further, when the mixing ratio of iron oxide is 60% by weight or more, it is not possible to mold a thin-walled molded product having a thickness of 1 mm, and as a result, the content of magnetic powder decreases, resulting in too low a magnetic force. .

[0034]

Industrial Applicability The bond magnet of the present invention has a low content of magnetic powder of 10 to 40% by weight, and iron oxide, Al ₂ O ₃ , SiO ₂ and CaC as inorganic fillers.
The content of one or more kinds selected from O ₃ is 30 to 6
By setting the content to 0% by weight and making the rest a flame-retardant resin composition, even when magnetized with a low magnetic force, it is possible to uniformly magnetize with little variation in the amount of magnetism, and also excellent in flame retardancy. It is now possible to provide bond magnets. In addition, a bond magnet having such characteristics is suitable as a material for a beam rotation correction magnet or a convergence adjustment magnet. By using the adjustment magnet created with the bond magnet, convergence adjustment and beam rotation correction can be easily performed. Further, it is possible to obtain an electron beam adjusting device having excellent flame retardancy.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the shape of a magnet molded body used in Example 1 and Comparative Example 1.

FIG. 2 is a graph showing the dependence of the magnetic flux density on the magnetizing voltage when the magnet moldings of Example 1 and Comparative Example 1 were magnetized.

FIG. 3 is an explanatory diagram showing an example of an electron beam adjustment device.

FIG. 4 is an explanatory view showing another example of the electron beam adjusting apparatus.

[Explanation of symbols]

 A Electron beam adjustment device B Cathode ray tube neck 1 Purity adjustment 2-pole magnet 2 Convergence adjustment 4-pole magnet 3 Convergence adjustment 6-pole magnet 4 Beam rotation correction 4-pole magnet

Claims (6)

[Claims] 1. A magnetic powder comprising an inorganic filler and a flame-retardant resin composition, wherein the content of the magnetic powder as a functional material is 10 to 40.
Iron oxide as an inorganic filler to be added for the purpose of improving the nonflammability and the rigidity, with a low content of weight%.
A bond magnet characterized in that the content of one or more selected from Al ₂ O ₃ , SiO ₂ , and CaCO ₃ is 30 to 60% by weight. 2. The composition of the bond magnet comprises 10 to 40% by weight of ferrite magnetic powder, 30 to 60% by weight of iron oxide, and a resin composition occupying the balance, wherein the flame-retardant resin composition is 100 parts by weight of a resin binder. , 30 to 60 parts by weight of an organic flame retardant containing halogen, antimony trioxide 15 to 3
The bond magnet according to claim 1, comprising 0 part by weight and 5 to 15 parts by weight of zinc borate. 3. The composition of the bond magnet comprises alnico metallic magnetic powder 10 to 40% by weight, iron oxide 30 to 60% by weight,
A flame-retardant resin composition occupying the balance, the resin composition comprising 100 parts by weight of a resin binder, 30 to 60 parts by weight of an organic flame retardant containing halogen, and antimony trioxide 15.
The bond magnet according to claim 1, which comprises -30 parts by weight and 5-15 parts by weight of zinc borate. 4. An electron beam adjusting device using the bond magnet according to claim 1, 2, or 3 as a material for an adjusting magnet. 5. An electron beam adjusting apparatus using the bond magnet according to claim 1, 2 or 3 as a material for a quadrupole magnet for beam rotation correction. 6. An electron beam adjusting device for a color cathode ray tube, comprising a four-pole convergence adjusting magnet with two poles, a six-pole magnet adjusting convergence and a two-pole magnet adjusting purity, and a four-pole magnet for convergence adjustment. And / or as a material for a 6-pole magnet for convergence adjustment,
An electron beam adjusting device using the bond magnet according to 2 or 3.