JPH0997729A - Flyback transformer and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To shorten the curing time of a flyback transformer (FBT). SOLUTION: (a) A mixture of 72 to 82 parts by weight of an epoxy compound represented by the chemical formula (Formula 1) and a brominated glycidyl ether derivative (bromine content: 40 to 60% by weight) 18 to 2
100 parts by weight of an epoxy mixture consisting of 8 parts by weight,
(B) 5 to 30 parts by weight of antimony trioxide powder, 40 to 100 parts by weight of hydrated alumina powder, and 30 to 30 parts of silica powder.
100 parts by weight, (c) an alicyclic acid anhydride represented by the following chemical formula (Formula 2), and (d) an imidazole compound represented by the following general formula (Formula 4) 0.2 to 2.5 parts by weight And a liquid epoxy resin precursor composition. Embedded image

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer (hereinafter abbreviated as FBT) obtained by insulation treatment using a liquid epoxy resin composition for casting having a fast curing rate, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, an FBT used in a television receiver or a display has a primary coil 2 wound around a first plastic bobbin 1 and a secondary coil bobbin 3 laminated on the primary coil 2. Wound secondary coil 4, 1
The structure is such that one or more high-voltage diodes 5 and a focus block 6 composed of a high-voltage resistor (however, a high-voltage capacitor may be included) are insulated by a casting resin 7 and housed in a case 8.

[0003] Of the constituent parts of the FBT,
For example, the coefficient of thermal expansion is completely different between the material of the bobbins 1 and 3 and the material of the coils 2 and 4. As described above, since the FBT is composed of components having different thermal expansion coefficients, it is important that the cast resin cured product 7 does not cause cracks and peeling during the heat cycle, and the electrical characteristics and flame retardancy And various properties such as moisture resistance are required.

Further, the FBT, which is a high-voltage component, is further miniaturized and has higher performance, which increases the temperature rise during use. Therefore, from the viewpoint of withstand voltage life, the FBT is a cured resin for casting. Is required to have heat resistance, and in general,
Glass transition temperature of 110 ° C or higher (hereinafter abbreviated as Tg)
Is said to have.

Further, from the viewpoint of coil insulation, the casting resin precursor composition before insulation treatment (before curing) needs to be sufficiently impregnated between the coils, and therefore the casting resin precursor composition before curing is required. Is required to have a high impregnation property.

In order to meet these requirements, a liquid resin precursor composition having well-balanced properties described above has been used as a liquid epichlorohydrin-bisphenol A.
-Type epoxy resin (epoxy compound), alicyclic acid anhydride methyltetrahydrophthalic anhydride (curing agent), and imidazole compound 1-cyanoethyl-2-ethyl-
A liquid epoxy resin precursor composition containing 4-methylimidazole (curing accelerator) or the like as a component is used as an FBT casting resin.

Further, as a technique for improving the performance of such a liquid epoxy resin precursor composition, Japanese Patent Publication No.
In 31282, it is described that the resin impregnation property between the coils is improved by performing an insulation treatment using an epoxy resin precursor composition containing hydrated alumina having a specific particle size. Further, Japanese Patent Laid-Open No. 1-150309 describes that electrical characteristics can be improved by performing insulation treatment using an epoxy resin precursor composition containing a stabilized red phosphorus flame retardant.

[0008]

This epoxy resin precursor composition is cured by two steps, a primary curing step (pre-curing step) and a secondary curing step (post-curing step), and the total curing time thereof is Was usually 5 hours or more.

In recent years, from the viewpoint of energy saving, it has become necessary to shorten the epoxy resin curing time by reviewing the FBT manufacturing process so as to rationalize the insulating treatment process using the epoxy resin. Generally, the curing time of the thermosetting resin becomes shorter when the curing temperature is higher. However, in the production of FBT, the plastic bobbin is deformed, and therefore the curing temperature must be 115 ° C. or lower.
Therefore, while keeping the secondary curing temperature at 105 to 115 ° C., the total curing time including the primary curing time can be reduced to the conventional (5
It is desired to shorten the time to 40-80% (2-4 hours).

Therefore, the present invention provides the following (1) to (4).
It is an object of the present invention to provide a liquid epoxy resin precursor composition satisfying the above conditions, an FBT including a cured product of the composition as an insulating agent, and a method for producing the same. (1) The liquid epoxy resin precursor composition before curing is sufficiently impregnated between the coils. (2) Even if the secondary curing temperature is 105 to 115 ° C., it is sufficiently cured in a total curing time of 2 to 4 hours. (3) The Tg of the cured product is 110 ° C. or higher. (4) 100 ° C / 2 hours and -50 ° C with respect to FBT
Even if the heat cycle test of 2 hours is performed for 50 cycles or more, the FBT containing the cured epoxy resin does not crack, and the cured epoxy resin does not peel off from other FBT components, resulting in performance as an FBT. Fully satisfied.

[0011]

In order to achieve the above object, in the present invention, as a liquid resin precursor composition for FBT insulation treatment, (a) epichlorohydrin-bisphenol A type represented by the following chemical formula (Formula 1) is used. 100 parts by weight of an epoxy mixture consisting of 72 to 82 parts by weight of an epoxy compound and 18 to 28 parts by weight of a mixture of brominated phenyl monoglycidyl ether and brominated cresyl monoglycidyl ether (bromine content: 40 to 60% by weight);

[0012]

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(Where n = 0-2, epoxy equivalent = 1
85-195. (B) 5 to 30 parts by weight of antimony trioxide powder, 40 to 100 parts by weight of hydrated alumina powder, and 30 to 100 parts by weight of silica powder, and (c) an alicyclic acid represented by the following chemical formula (Formula 2). Anhydrous,

[0014]

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(D) 0.2 to 2.5 parts by weight of an imidazole compound represented by the following general formula (Formula 3)

[0016]

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(Here, one of R ¹ and R ² is a methyl group and the other is hydrogen.) A liquid epoxy resin precursor composition is provided. In addition, (a) is an epoxy resin, (b) is a filler, (c) is a curing agent, and (d) is a curing accelerator. The amount of the alicyclic acid anhydride of (c) is
With respect to 1 epoxy equivalent of the epoxy mixture of (a), 0.
7 to 1.2 acid anhydride equivalent.

The liquid epoxy resin precursor composition comprises 0.1 to 10 parts by weight of a silane coupling agent having an epoxy group (eg, γ-glycidoxypropyltrimethoxysilane), based on 100 parts by weight of the epoxy mixture. Is preferably further included.

Further, the present invention provides an FBT comprising an epoxy resin cured product obtained by curing the above liquid epoxy resin precursor composition as an insulating material.

Further, in the present invention, the liquid epoxy resin precursor composition described above is poured into a case, and the temperature is 65 to 85 ° C.
After maintaining the temperature of 1.0 to 1.7 hours (primary curing step), the temperature is raised to 105 ° C. in 0.4 to 0.8 hours,
Provided is a method for producing an FBT, which comprises a curing step of holding at a temperature of ~ 115 ° C for 0.6 to 1.5 hours (secondary curing step). The case for casting may be used as it is as the case 8 (shown in FIG. 1) of the FBT. It may be removed after the curing step, and the contents such as the coil may be stored in a new case together with the cured resin. You may do it. According to the present invention, the total curing time is the sum of the primary curing time, the temperature rising time and the secondary curing time, so that according to the present invention, it is 2 to 4 hours.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin precursor composition of the present invention contains a specific alicyclic acid anhydride curing agent which gives a cured product of a heat resistant resin and a specific rapid curing type curing accelerator (imidazole compound). The composition described above has a short curing time and a high Tg of the cured product, and thus is particularly suitable for the production of FBT.

By subjecting the above liquid epoxy resin precursor composition for casting to an insulating treatment under the curing conditions according to the present invention, the curing conditions of the secondary curing step are set at temperatures of 105 to 115.
Since the temperature and the total curing time can be set to 2 to 4 hours, the FBT can be manufactured in a shorter time than before.

Further, the epoxy resin precursor composition of the present invention has a high impregnating property and is sufficiently impregnated between the coils, and the epoxy resin cured product obtained by curing has a Tg of 110 ° C. or higher. In addition, the FBT insulation treated with this resin
Shows no cracks in the cured epoxy resin even after a heat cycle test of 100 ° C./2 hours and −50 ° C./2 hours for 50 cycles or more, and the cured epoxy resin is separated from other FBT components. FBT does not occur, and sufficiently satisfies other necessary initial characteristics (electrical characteristics, various characteristics such as flame resistance and moisture resistance) and life characteristics, and is high performance.

(A) Epoxy Mixture The epoxy mixture contained in the epoxy resin precursor composition of the present invention comprises 72 to 82 parts by weight of an epichlorohydrin-bisphenol A type epoxy compound represented by the following chemical formula (Formula 1) and a bromine compound. Mixture (bromine content: 40-60
% By weight) 18 to 28 parts by weight.

[0025]

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(Here, n = 0 to 2, epoxy equivalent = 1
85-195. ) The mixture of bromine compounds is a mixture of brominated phenyl monoglycidyl ether and brominated cresyl monoglycidyl ether, the bromine content of which is 40 to 60% by weight).
It is. The blending amount of the bromine compound mixture is preferably 18 to 28 parts by weight when the total amount of the epoxy mixture is 100 parts by weight. If the amount of the bromine compound mixture is less than 18 parts by weight, not only the flame retardancy of the resin cured product is insufficient but also the viscosity of the liquid resin precursor composition is high, so that the coil impregnation property is deteriorated.
If the amount is more than the amount by weight, the heat cycle resistance of the cured resin decreases, and the performance of FBT is not satisfied.

(B) Filler The compounding amount of the antimony trioxide powder is 10% by weight of the epoxy mixture.
5 to 30 parts by weight is preferable to 0 parts by weight. If the amount of the antimony trioxide powder is less than 5 parts by weight, the flame retardancy of the resin cured product is insufficient, and if it is more than 30 parts by weight, the viscosity of the liquid resin precursor composition is high and the coil impregnability is reduced. Then
Both do not satisfy the performance of FBT.

The amount of the hydrated alumina powder blended is preferably 40 to 100 parts by weight with respect to 100 parts by weight of the epoxy mixture. When the amount of hydrated alumina powder is less than 40 parts by weight, the flame retardancy of the resin cured product is insufficient, and when it is more than 100 parts by weight, the viscosity of the liquid resin precursor composition is high and the coil impregnability is reduced. However, both do not satisfy the performance of FBT.

The blending amount of silica powder is the epoxy mixture 1
30 to 100 parts by weight is preferable to 00 parts by weight. When the amount of silica powder is less than 30 parts by weight, the thermal conductivity at the time of curing the liquid resin precursor composition is lowered, so that the heat resistance of the cured resin product becomes insufficient. Since the resin precursor composition has a high viscosity, the coil impregnation property is deteriorated, and the performance of FBT is not satisfied.

(C) Curing Agent In the present invention, as a curing agent for epoxy resin, the following chemical formula is used.
The alicyclic acid anhydride of the curing agent represented by (Chemical Formula 2) is used. This curing agent is an essential component for chemically reacting the liquid resin precursor composition to convert it into a resin cured product and exhibiting the performance of FBT.

[0031]

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In place of the acid anhydride represented by the above chemical formula (Chemical formula 2) or by mixing with the compound represented by the chemical formula (Chemical formula 2), an alicyclic ring represented by the following general formula (Chemical formula 4) The formula acid anhydride may be used.

[0033]

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The amount of the curing agent is such that the compounding ratio of 0.7 to 1.2 acid anhydride equivalent to 1 epoxy equivalent of the epoxy mixture is good, and it is represented by the compound represented by (Chemical formula 2) and the formula (Chemical formula 4). When mixed with other compounds, the total amount of them should be in this compounding ratio. When the amount of the curing agent is less than 0.7 equivalent, the curing reactivity of the liquid resin precursor composition is low, so that the Tg of the resin cured product is low, and when the mixing ratio of the curing agent is more than 1.2 equivalents, the unreacted amount is not high. Due to the plasticizing effect of the reaction curing agent, the Tg of the cured resin becomes low, and neither of them satisfies the performance of FBT.

(D) Curing accelerator The imidazole compound represented by the following general formula (Formula 3) is a component necessary for promoting the curing reaction of the epoxy resin.

[0036]

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The compounding amount of this curing accelerator is preferably 0.2 to 2.5 parts by weight with respect to 100 parts by weight of the epoxy mixture. When the amount of the curing accelerator is less than 0.2 parts by weight, the curing reactivity of the liquid resin precursor composition is low, so that the Tg of the resin cured product is low, and when it is more than 2.5 parts by weight, the unreacted curing agent plasticizes. Due to the effect, the Tg of the resin cured product becomes low, and both do not satisfy the performance of FBT.

(E) Adhesion Promoter It is desirable to incorporate a silane coupling agent having an epoxy group as an adhesion promoter into the liquid epoxy resin precursor composition of the present invention. The silane coupling agent does not have to be blended with the liquid resin precursor composition, but in particular, an epoxy resin, a filler (antimony trioxide,
Hydrated alumina, silica) and FBT components (bobbins,
In order to further promote the adhesion of the coil, the diode, etc., it is effective to mix them. As the silane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane can be used.

In order to improve the adhesion promoting effect, the amount of the silane coupling agent is preferably 0.1 parts by weight or more per 100 parts by weight of the epoxy mixture, and more than 10 parts by weight does not change the effect. . That is, 0.1 part of the silane coupling agent is added to 100 parts by weight of the epoxy mixture.
When blended at 10 parts by weight, epoxy resin, filler and F
The adhesion of BT components is further promoted, and the performance of FBT is further improved.

(F) Curing Conditions The above liquid epoxy resin precursor composition has the following conditions i to
When cured in iii, the secondary curing temperature is 105-115 ° C.
In that case, the total curing time can be set to 2 to 4 hours, which is preferable from the viewpoint of shortening the curing time. The epoxy resin cured product obtained by curing this composition under these conditions has a Tg of 110 ° C. or higher, which sufficiently satisfies the FBT performance.

I. Primary curing condition: Hold at a temperature of 65 to 85 ° C. for 1.0 to 1.7 hours ii. Temperature rising time from primary curing temperature to secondary curing temperature: 0.
4-0.8 hours iii. Secondary curing condition: 0.6-at a temperature of 105-115 ° C.
Hold for 1.5 hours When the primary curing temperature is lower than 65 ° C, the liquid resin precursor composition is not sufficiently impregnated. Therefore, the primary curing time is 1.
The area not impregnated with the resin remains even after 7 hours or more. Further, if the primary curing temperature is higher than 85 ° C., the curing reaction will be too fast, so even if the primary curing time is set to 1.0 hours, peeling and cracking will occur and the FBT performance will not be satisfied.

If the secondary curing temperature is lower than 105 ° C., the Tg of the cured epoxy resin does not rise to 110 ° C. even if the primary curing time is 1.5 hours or longer, and if it is higher than 115 ° C., 0.6. The plastic bobbin is deformed even by curing for a long time, and the heat cycle resistance of the cured epoxy resin becomes insufficient, so that the performance of the FBT is not satisfied.

When the temperature rising time from the primary curing temperature to the secondary curing temperature is shorter than 0.4 hours, the heat cycle resistance of the cured epoxy resin product becomes insufficient and the performance of FBT is not satisfied, so that 0.8 The performance of the FBT does not change even if it is longer than the time.

[0044]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition,
In each of the examples and comparative examples, each component of the epoxy resin precursor composition is abbreviated. The abbreviations have the following meanings.

EPX represents an epichlorohydrin-bisphenol A type epoxy resin represented by the following chemical formula (Formula 1). However, n is an integer of 0 to 2 and the epoxy equivalent is 190.

[0046]

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Me-THPA represents a curing agent, methyltetrahydrophthalic anhydride, represented by the following chemical formula (Formula 2). Me-THPA is an alicyclic acid anhydride as a curing agent.
In this embodiment, "HN-220" manufactured by Hitachi Chemical Co., Ltd.
0 ”was used.

[0048]

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1M2EZ represents 1-methyl-2-ethylimidazole represented by the following chemical formula (Formula 5). Also,
2E4MZ represents 2-ethyl-4-methylimidazole represented by the following chemical formula (Formula 6). Both 1M2EZ and 2E4MZ are imidazole compounds as curing accelerators. In this example, a commercial product manufactured by Shikoku Chemicals Co., Ltd. was used.

[0050]

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[0051]

[Chemical 6]

EB-200B refers to a mixture of brominated phenyl monoglycidyl ether and brominated cresyl monoglycidyl ether. In this example, a commercially available product "EB-200B" manufactured by Manac Co., which has a mixture of dibromophenyl monoglycidyl ether and dibromocresyl monoglycidyl ether as a main component, has a bromine content of 51% and an epoxy equivalent of 326, was used.

X-CN represents 1-cyanoethyl-2-ethyl-4-methylimidazole, which is an imidazole curing accelerator for comparative examples.

SbO is a filler antimony trioxide Sb.
₂ O ₃ is shown. In this example, as antimony trioxide,
A powder having an average particle size of 0.5 μm was used. Also, AlOH
Indicates a hydrated alumina powder as a filler. In this embodiment,
The hydrated alumina powder used had an average particle size of 8 μm. SiO indicates silica powder SiO ₂ as a filler. In this example, silica powder having an average particle size of 13.4 μm was used.

KBM403 represents a silane coupling agent, γ-glycidoxypropyltrimethoxysilane.
In this embodiment, a commercial product “KBM40 manufactured by Shin-Etsu Chemical Co., Ltd.
3 "was used.

<Example 1> a. Preparation of Liquid Epoxy Resin Precursor Composition EPX 72 parts by weight, EB-200B 28 parts by weight, S
bO 10 parts by weight, AlOH 60 parts by weight, SiO70
Parts by weight, Me-THPA 69.6 parts by weight, 1M2E
Z 1.0 part by weight was mixed to obtain a liquid epoxy resin precursor composition.

B. Manufacturing of FBT As shown in FIG. 1, inside, a primary coil 2 dividedly wound on a first plastic bobbin 1, a secondary coil 4 laminatedly wound on a second plastic bobbin 3, and at least one high voltage Focus block 6 consisting of diode 5 and high-voltage resistor (however, it may include high-voltage capacitor)
A liquid epoxy resin precursor composition was vacuum-injected at 1.3 to 2.6 kPa into a case 8 including the above components, and the liquid epoxy resin precursor composition was injected at 75 ° C. for 1.5 hours.
After holding (primary curing) for a period of time, the temperature was raised from 75 ° C. to 110 ° C. over 0.5 hour, and held at 110 ° C. for 1 hour (secondary curing) to obtain an FBT insulation-treated product.

C. Method of Characterizing FBT The characteristics of the epoxy resin cured product and the FBT insulation-treated by resin curing were evaluated as follows.

(1) Glass transition temperature Tg of cured resin
(° C): Measured by a differential scanning calorimeter (DSC). 11
A resin cured product having a Tg of 0 ° C. or higher is “good”, 110
Those having a Tg of less than ° C were designated as "poor".

(2) Heat cycle resistance of FBT: 100 ° C./about FBT having good initial operation characteristics after insulation treatment
After 60 heat cycles of 2 hours and −50 ° C./2 hours were performed, the operating characteristics of the FBT were examined and the “pass / fail” of practicality was determined.

(3) Impregnation of FBT coil: FBT after insulation treatment was cut and polished, and the presence or absence of internal voids was confirmed by microscopic observation (about 80 times). The absence of voids was defined as “good”, and the presence of voids was defined as “poor”.

(4) Flame retardancy: The cured resin product was evaluated according to UL standards using test pieces of 127 mm × 12.7 mm × 1.6 mm. The insulated FBT was evaluated according to the Electrical Appliance and Material Control Law. Flame retardancy of cured resin is UL9
When the flame retardancy of the FBT was equivalent to 4V-0 and the flame retardancy of the FBT was equivalent to passing the Electrical Appliance and Material Control Law, it was rated as "O", and otherwise it was rated as "X".

(5) Electrical characteristics of cured resin: According to JIS standard K6911, relative dielectric constant (ε) and dielectric loss tangent (tan δ) at a predetermined temperature of 10 kHz, DC500V1
The volume resistivity (ρv) after each minute was determined. At 25 ° C,
ε ≦ 3.9, tan δ (%) ≦ 1.2, ρv (Ω · cm) ≧ 1
X 10 ¹⁵ is satisfied, and ε ≦ 4 even at 100 ° C.
1, tan δ (%) ≦ 1.6, ρv (Ω · cm) ≧ 1 × 10
^When both ¹³ were satisfied, the electrical properties of the resin cured product were good, and "○" was given, and otherwise, it was bad and "x".

(6) Moisture resistance of cured resin: 60 ° C, 95%
Using a test piece left in the RH atmosphere for 1000 hours, J
According to IS standard K6911, ε and tan δ at 10 kHz and water absorption at 25 ° C. were obtained, respectively. ε
When both ≦ 5.0, tan δ (%) ≦ 4.0, and water absorption rate (%) ≦ 1.0 are satisfied, the resin cured product has good moisture resistance and is “○”. And

(7) Adhesiveness of cured resin: Polybutylene terephthalate (PBT), which is one of bobbins and case materials, is selected, and a PBT plate having a size of 12 mm × 12 mm × 3 mm is bonded to an area of 1 cm. ^It is sandwiched between ^two aluminum rods, and a liquid epoxy resin precursor composition is adhered to an adhesive layer of about 50 μm between the aluminum rods and the PBT plate, which is heat-cured under the above conditions to obtain an adhesive sample. It was determined by a tensile test between the bars. After the tensile test, the fracture surface was observed, and it was confirmed that the cured resin and the PBT plate were peeled off from each other in all the samples.

(8) Performance of FBT: By satisfying the initial characteristics and the life characteristics required by the FBT, the performance is sufficiently satisfied without abnormality such as dielectric breakdown during the operation test, and ""○", otherwise "x".

D. Evaluation Results As shown in Table 1, the resin cured product and FBT of this example showed good results.

<Examples 2 and 3> In the same manner as in Example 1,
FBT was manufactured and evaluated. However, the liquid epoxy resin precursor compositions having the compositions shown in Table 1 were used. Examples 2-3 are E in the epoxy compound.
Although the blending ratio of B-200B was different from that in Example 1, as shown in Table 1, the same good results as in Example 1 were obtained.

[0069]

[Table 1]

<Examples 4 to 5> In the same manner as in Example 2,
FBT was manufactured and evaluated. However, in Example 4, the minimum amount of three kinds of fillers was used, and in Example 5, the maximum amount of three kinds of fillers was used. In Examples 4 to 5 as well, as shown in Table 1, the same good results as in Example 2 were obtained.

<Examples 6 to 7> In Examples 6 to 7, FBT was produced and evaluated in the same manner as in Example 2 except that the compounding ratio (equivalent ratio) of the acid anhydride curing agent was different. By the way
As shown in Table 2, good results similar to those of Example 2 were obtained.

[0072]

[Table 2]

<Examples 8 to 10> In the same manner as in Example 2, FBT was manufactured and evaluated. However, Examples 8 to 1
In No. 0, the liquid epoxy resin precursor composition used was the composition of Example 2 to which the silane coupling agent KBM403 was further added at the compounding ratio shown in Table 2. Good results were obtained also in Examples 8 to 10.

<Examples 11 to 12> The mixing ratio of the accelerator 1M2EZ contained in the liquid epoxy resin precursor composition was as follows.
FBT was produced and evaluated in the same manner as in Example 2 except that as shown in Table 3, good results were obtained at any mixing ratio, as shown in Table 3.

[0075]

[Table 3]

<Examples 13 to 15> Example 2 was repeated except that 2E4MZ was used in place of 1M2EZ as the accelerator contained in the liquid epoxy resin precursor composition and the mixing ratio was as shown in Table 3. When FBT was manufactured and evaluated in the same manner as in, good results were obtained in all Examples as shown in Table 3.

Examples 16 to 35 In Examples 16 to 35, the same epoxy resin precursor composition as in Example 2 was used, except that the compound and / or the amount of the curing accelerator was different, and the curing conditions were changed. FB in the same manner as in Example 2 except that
T was produced. As shown in Tables 4 to 8, good results similar to those in Example 2 were obtained in all Examples.

In each of Examples 16 to 19, FBT was produced and evaluated in the same manner as in Example 1 except that the liquid epoxy resin precursor composition having the composition shown in Table 4 was used. However, the curing of the epoxy resin is maintained at 65 ° C for 1.0 hour (primary curing).
After that, the temperature was raised from 65 ° C. to 105 ° C. over 0.4 hours and held at 105 ° C. for 0.6 hours (secondary curing). Resin and FB obtained in each example
Table 4 shows the T evaluation results.

[0079]

[Table 4]

Also in Examples 20 to 23, FBT was produced and evaluated in the same manner as in Example 2 using the liquid epoxy resin precursor composition having the composition shown in Table 5. However, the epoxy resin is cured by maintaining it at 85 ° C. for 1.7 hours (primary curing), then increasing the temperature from 85 ° C. to 115 ° C. over 0.8 hours, and maintaining it at 115 ° C. for 1.5 hours (secondary curing). Curing). Resin and FB obtained in each example
Table 5 shows the T evaluation results.

[0081]

[Table 5]

Also in Examples 24 to 27, the liquid epoxy resin precursor composition having the composition shown in Table 6 was used, and in the same manner as in Example 2, FBT was produced and evaluated. However, the epoxy resin is cured by holding it at 65 ° C. for 1.0 hour (primary curing), then raising it from 65 ° C. to 115 ° C. over 0.4 hours, and holding it at 115 ° C. for 0.6 hour (secondary curing). Curing). Resin and FB obtained in each example
Table 6 shows the T evaluation results.

[0083]

[Table 6]

In Examples 28 to 31, FBT was produced and evaluated in the same manner as in Example 2, using the liquid epoxy resin precursor composition having the composition shown in Table 7. However, the epoxy resin is cured by holding it at 85 ° C for 1.0 hour (primary curing), then raising it from 85 ° C to 105 ° C over 0.4 hours, and holding it at 105 ° C for 0.6 hours (secondary curing). Curing). Resin and FB obtained in each example
Table 7 shows the T evaluation results.

[0085]

[Table 7]

In Examples 32 to 35, the liquid epoxy resin precursor compositions having the compositions shown in Table 8 were used and FBT was produced and evaluated in the same manner as in Example 2. However, the epoxy resin is cured by holding it at 65 ° C. for 1.0 hour (primary curing), then raising it from 65 ° C. to 110 ° C. over 0.8 hours, and holding it at 110 ° C. for 0.6 hour (secondary curing). Curing). Resin and FB obtained in each example
Table 8 shows the T evaluation results.

[0087]

[Table 8]

<Comparative Examples 1 to 18> In the same manner as in Example 1, FBT was manufactured and evaluated. However, each of the liquid epoxy resin precursor compositions having the compositions shown in Tables 9 to 13 was used, and after being held (primary curing) at 75 ° C for 1.5 hours, the temperature was changed from 75 ° C to 110 ° C for 0.5 hours. Then, the temperature is raised and held at 110 ° C. for 1.0 hour (secondary curing),
The epoxy resin was cured. In each comparative example, Table 9
As shown in ~ 12, it was not possible to obtain an FBT with sufficient performance.

[0089]

[Table 9]

[0090]

[Table 10]

[0091]

[Table 11]

[0092]

[Table 12]

In Comparative Examples 1 and 2, the blending ratio of EB-200B in the epoxy compound is out of the range of the present invention. Further, in Comparative Examples 3 to 10, the blending ratio of any one of the three kinds of fillers is out of the range of the present invention. In Comparative Examples 11 and 12, the compounding ratio (equivalent ratio) of the acid anhydride curing agent to the epoxy compound is out of the range of the present invention.

In Comparative Examples 13 to 18, the compounding ratio of the curing accelerator to the epoxy compound is out of the range of the present invention. However, in Comparative Examples 13 and 14, the accelerator is 1M2EZ, and in Comparative Examples 15 and 16, the accelerator is 2M.
E4MZ, Comparative Examples 17 and 18 have 1M accelerator
2EZ containing the silane coupling agent KBM403.

<Comparative Examples 19 to 32> Comparative Examples 19 to 32
Is a comparative example in which the same liquid epoxy resin precursor composition as in Example 2 was used and the curing conditions of the resin precursor composition were outside the scope of the present invention. However, Comparative Examples 20, 22, 24,
In 26, 28, 30, and 32, 2E4MZ was used instead of 1M2EZ as the curing accelerator.

The curing conditions in each comparative example are as follows. In Comparative Examples 19 to 20, after holding at 60 ° C. for 1.5 hours (primary curing), the temperature was changed from 60 ° C. to 100 ° C. by 0.5.
The temperature was raised over time and the temperature was maintained at 100 ° C. for 1.0 hour (secondary curing) to cure the epoxy resin.

In Comparative Examples 21 to 22, after holding (primary curing) at 90 ° C. for 1.5 hours, 90 ° C. to 12
The temperature was raised to 0 ° C. over 0.5 hours, and the temperature was maintained at 120 ° C. for 1.0 hour (secondary curing) to cure the epoxy resin. In Comparative Examples 19 to 22, as shown in Table 13, it was not possible to obtain an FBT with sufficient performance.

[0098]

[Table 13]

In Comparative Examples 23 to 24, after holding at 60 ° C. for 1.5 hours (primary curing), the temperature was raised from 60 ° C. to 120 ° C. over 0.5 hours and kept at 120 ° C. for 1.0 hour ( Secondary curing) and curing the epoxy resin,
As shown in Table 14, it was not possible to obtain an FBT with sufficient performance.

[0100]

[Table 14]

In Comparative Examples 25 to 26, after holding (primary curing) at 90 ° C. for 1.5 hours, 90 ° C. to 10
The temperature was raised to 0 ° C. over 0.5 hours, and the temperature was maintained at 100 ° C. for 1.0 hour (secondary curing) to cure the epoxy resin. In Comparative Examples 27 to 28, after holding at 60 ° C. for 1.0 hour (primary curing), the temperature was raised from 60 ° C. to 120 ° C. over 0.8 hours and kept at 120 ° C. for 1.5 hours (secondary curing). )do it,
The epoxy resin was cured. In each of Comparative Examples 25 to 28, as shown in Table 15, FBT having sufficient performance
Couldn't get

[0102]

[Table 15]

In Comparative Examples 29 to 30, after holding at 75 ° C. for 1.5 hours (primary curing), the temperature was raised from 75 ° C. to 120 ° C. over 0.5 hours and held at 120 ° C. for 1.0 hour ( Secondary curing) was performed to cure the epoxy resin. Also,
In Comparative Examples 31 to 32, after holding at 60 ° C. for 1.5 hours (primary curing), the temperature was raised from 60 ° C. to 115 ° C. over 0.8 hours and held at 115 ° C. for 1.0 hour (secondary curing). ) And cured the epoxy resin. In all of Comparative Examples 29 to 32, as shown in Table 16, F of sufficient performance was obtained.
I couldn't get a BT.

[0104]

[Table 16]

<Comparative Examples 33-40> Comparative Examples 33-40
Is X-CN instead of 1M2EZ as a curing accelerator.
FBT was prepared and evaluated in the same manner as in Example 2 except that was used. Under any of the curing conditions of Comparative Examples 33 to 40, as shown in Tables 17 to 18, it was not possible to obtain an FBT with sufficient performance.

In Comparative Examples 33 to 34, after holding at 65 ° C. for 1.0 hour (primary curing), the temperature was raised from 65 ° C. to 105 ° C. over 0.4 hours and held at 105 ° C. for 0.6 hour ( Secondary curing) was performed to cure the epoxy resin. Also,
In Comparative Examples 35 to 36, after holding at 85 ° C. for 1.7 hours (primary curing), the temperature was raised from 85 ° C. to 115 ° C. over 0.8 hours and kept at 115 ° C. for 1.5 hours (secondary curing). ) And cured the epoxy resin. Table 18 shows the evaluation results of the resins and FBTs obtained in Comparative Examples 33 to 36.

[0107]

[Table 17]

In Comparative Examples 37 to 38, after holding at 65 ° C. for 1.0 hour (primary curing), the temperature was raised from 65 ° C. to 115 ° C. over 0.4 hours and kept at 115 ° C. for 0.6 hour ( Secondary curing) was performed to cure the epoxy resin. In Comparative Examples 39 to 40, holding at 65 ° C. for 1.0 hour (primary curing)
After that, the temperature was raised from 65 ° C. to 110 ° C. over 0.8 hours and maintained at 110 ° C. for 0.6 hours (secondary curing) to cure the epoxy resin. Table 18 shows the evaluation results of the resins and FBTs obtained in Comparative Examples 39 to 40.

[0109]

[Table 18]

<Evaluation of Examples and Comparative Examples> As described above, the resin compositions, curing conditions and characteristics of Examples 1 to 35 (shown in Tables 1 to 8) and Comparative Examples 1 to 40. Comparing the resin compositions, curing conditions and properties (shown in Tables 9 to 18), it is clear that the liquid epoxy resin precursor compositions of Examples 1 to 35 and their cured products are FBT casting resins. Both the properties required for the precursor composition and its cured product are satisfied, and the produced FBT has satisfactory performance. On the other hand, the liquid epoxy resin precursor compositions of Comparative Examples 1 to 40 and / or their cured products were FBT.
Since the properties required for the casting resin precursor composition and / or its cured product cannot be satisfied in a well-balanced manner, the performance of the produced FBT was also unsatisfactory.

[0111]

As described above, according to the present invention,
By using a specific heat-resistant and fast-curing type liquid epoxy resin precursor composition to insulate the FBT under a specific curing condition, the resin precursor composition is sufficiently impregnated between the coils, and the secondary (after) ) The epoxy resin can be sufficiently cured at a curing temperature of 105 to 115 ° C. and a total curing time of 2 to 4 hours. The Tg of the obtained cured epoxy resin is 11
The temperature of the FBT is 0 ° C or higher, and the insulation-treated FBT has excellent heat cycle resistance, and other necessary initial characteristics (electrical characteristics,
It also has high performance, satisfying various characteristics such as flame retardancy and moisture resistance) and life characteristics.

Therefore, according to the present invention, an FBT having sufficient performance can be provided at 40 to 80% (2 to 4 hours) of the conventional (5 hours).
Since it can be manufactured with the curing time of 1, the FBT manufacturing process can be rationalized, and the energy saving of the FBT manufacturing used for the television receiver and the display can be realized, which is of great industrial value.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a flyback transformer.

[Explanation of symbols]

1 ... Primary bobbin, 2 ... Primary coil, 3 ... Secondary bobbin, 4
... secondary coil, 5 ... high voltage diode, 6 ... focus block (including high voltage resistance), 7 ... cast epoxy resin precursor composition (or cured product), 8 ... case.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08K 3/36 NKX C08K 3/36 NKX 5/15 5/15 C08L 63/02 NLA C08L 63/02 NLA H01F 41/00 H01F 41/00 C (72) Inventor Ryoichi Sudo No. 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Production Engineering Laboratory, Hitachi, Ltd. (72) Mitsuo Otsu Mashiro, Mizusawa-shi, Iwate Prefecture Kitano No. 1 in Hitachi Media Electronics Co., Ltd. (72) Inventor Etsuo Tsurumi Masaki, Mizusawa City, Iwate Prefecture No. 1 Kitano in Hitachi Media Electronics Co., Ltd. (72) Inventor Masahiro Suzuki 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Factory

Claims (6)

[Claims] 1. A flyback transformer having an insulating material inside, wherein the insulating material comprises: (a) 72 to 82 parts by weight of epichlorohydrin-bisphenol A type epoxy compound represented by the following chemical formula (Formula 1) and brominated phenyl. 100 parts by weight of an epoxy mixture consisting of 18 to 28 parts by weight of a mixture of monoglycidyl ether and brominated cresyl monoglycidyl ether (bromine content: 40 to 60% by weight); (Where n = 0-2, epoxy equivalent = 185-195
It is. (B) 5 to 30 parts by weight of antimony trioxide powder, 40 to 100 parts by weight of hydrated alumina powder, and 30 to 30 parts of silica powder.
100 parts by weight, (c) an alicyclic acid anhydride represented by the following chemical formula (Formula 2), and (D) 0.2 to 2.5 parts by weight of an imidazole compound represented by the following general formula (Formula 3) (Here, one of R ¹ and R ² is a methyl group,
The other is hydrogen. ), And the amount of the alicyclic acid anhydride of (c) is 0.7 to 1.2 acid anhydride equivalent to 1 epoxy equivalent of the epoxy mixture of (a). Liquid epoxy resin precursor composition A flyback transformer, which is an insulating material obtained by curing an object. 2. The liquid epoxy resin precursor composition according to claim 1, further comprising 0.1 to 10 parts by weight of a silane coupling agent having an epoxy group, based on 100 parts by weight of the epoxy mixture. Flyback transformer. 3. A method for manufacturing a flyback transformer, which comprises a step of injecting a liquid epoxy resin precursor composition into a case and a step of curing the liquid epoxy resin precursor composition. The composition is (a) a mixture of 72 to 82 parts by weight of an epichlorohydrin-bisphenol A type epoxy compound represented by the following chemical formula (Formula 1) and a brominated phenyl monoglycidyl ether and a brominated cresyl monoglycidyl ether (bromine content: 40 to 60% by weight) 18 to 28 parts by weight of an epoxy mixture of 100 parts by weight; (Where n = 0-2, epoxy equivalent = 185-195
It is. (B) 5 to 30 parts by weight of antimony trioxide powder, 40 to 100 parts by weight of hydrated alumina powder, and 30 to 30 parts of silica powder.
100 parts by weight, (c) an alicyclic acid anhydride represented by the following chemical formula (Formula 2), and (D) 0.2 to 2.5 parts by weight of an imidazole compound represented by the following general formula (Formula 3) (Here, one of R ¹ and R ² is a methyl group,
The other is hydrogen. The amount of the alicyclic acid anhydride of the above (c) is 0.7 to 1.2 acid anhydride equivalent to 1 epoxy equivalent of the epoxy mixture of the above (a), and the above liquid epoxy The step of curing the resin precursor composition includes a primary curing step of maintaining the temperature of 65 to 85 ° C. for 1.0 to 1.7 hours and a temperature of the secondary curing temperature of 0.4 to 0.8 hours. A flyback transformer comprising a temperature raising step and a secondary curing step of maintaining the secondary curing temperature for 0.6 to 1.5 hours, wherein the secondary curing temperature is 105 to 115 ° C. Manufacturing method. 4. The liquid epoxy resin precursor composition according to claim 3, further comprising 0.1 to 10 parts by weight of a silane coupling agent having an epoxy group, based on 100 parts by weight of the epoxy mixture. And a method of manufacturing a flyback transformer. 5. An epichlorohydrin / bisphenol A type epoxy compound 72 represented by the following chemical formula (Formula 1):
To 82 parts by weight and 18 to 28 parts by weight of a mixture of brominated phenyl monoglycidyl ether and brominated cresyl monoglycidyl ether (bromine content: 40 to 60% by weight), 100 parts by weight of an epoxy mixture, ] (Where n = 0-2, epoxy equivalent = 185-195
It is. (B) 5 to 30 parts by weight of antimony trioxide powder, 40 to 100 parts by weight of hydrated alumina powder, and 30 to 30 parts of silica powder.
100 parts by weight, (c) an alicyclic acid anhydride represented by the following chemical formula (Formula 2), and (D) 0.2 to 2.5 parts by weight of an imidazole compound represented by the following general formula (Formula 3) (Here, one of R ¹ and R ² is a methyl group,
The other is hydrogen. ), And the amount of the alicyclic acid anhydride of (c) is 0.7 to 1.2 acid anhydride equivalent to 1 epoxy equivalent of the epoxy mixture of (a). Epoxy resin precursor composition. 6. The liquid epoxy resin precursor composition according to claim 5, further comprising 0.1 to 10 parts by weight of a silane coupling agent having an epoxy group with respect to 100 parts by weight of the epoxy mixture.