JPS5978268A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. excellent in electrical characteristics, flame retardance and safety, and well suited for preparation of flyback transformers, by incorporating acid anhydrides, reaction accelerators, and hydrated aluminum powder and red phosphorus in a particular wt. ratio with epoxy resins. CONSTITUTION:Acid anhydrides (e.g., methyltetrahydrophthalic anhydride) as curing agents and reaction accelerators (e.g., 2-ethyl-4-methylimidazole) are mixed with epoxy resins. Furthermore, hydrated aluminum powder and red phosphorus, as flame retardants and fillers, are incorporated with the mixture so that the amts. of hydrated alumina powder and red phosphorus to be blended with 100pts.wt. epoxy resin are within limits enclosed with lines connecting points A, B, C, D, E, F, G, an H slown in the table in order, yielding the intended epoxy resin compsn. Flyback transformers subjected to insulation treatment with said compsn. do not generate harmful gases on burning.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition used when manufacturing a flyback transformer by insulating a flybank transformer for a television receiver. .

It is well known that safety requirements for electronic components are becoming stronger and stronger these days.In particular, fly bank transformers (hereinafter referred to as FBT) for television receivers are
Once upon a time, when color television began to become popular in the United States,
Since there have been many fire accidents thought to be caused by damage to FBTs, strict regulations have been put in place regarding the flame retardancy of FBTs and the insulating materials used therefor. Specifically, F
B T insulating materials must have a flammability of q4V-0 or higher according to UL Standard 94, and the FBT itself must pass a combustion test based on Attached Table 82 (94) of the Peeping Equipment Control Act. No.

As the resin for impregnation, insulation coating, and coating formation for FBT, heat-curable liquid epoxy resin compositions with excellent electrical properties and adhesive properties are used. However, since epoxy resin itself is a polymer material with a skeleton of carbon atoms, oxygen atoms, and hydrogen atoms, it is essentially a flammable substance.
(m) Method of blending agents such as chlorinated paraffin, hexabromobenzene, perchloropentacyclodecane, decabrom diphenyl ether, etc. Using halogenated epoxy resins such as tetrabromo bisphenol A diglyndyl ether, dibromo cresyl glycidyl ether, etc. There are also methods using the above methods in combination with antimony trioxide. However, epoxy resin compositions made flame-retardant by these methods have the disadvantage that, when burned, they generate a large amount of harmful gas containing hydrogen halide as a main component, and emit a large amount of black smoke. Furthermore, since most halogen flame retardants and antimony trioxide are harmful to the human body, strict precautions must be taken when manufacturing, using, or disposing of these epoxy resin compositions. equipment is required. On the other hand, in terms of properties, halogen-based flame retardants or halogenated epoxy resins are expensive, and when used in large amounts they reduce tracking and arc resistance, There are problems such as the electrodes becoming more easily corroded by the released carbon dioxide.

The purpose of the present invention is to be able to safely perform FBT insulation treatment without generating toxic gas when burning FBT, without corroding magnet wires or electrodes, and having a long pot life with excellent dielectric and electrical properties. It has good workability and
An object of the present invention is to provide an epoxy resin composition that does not cause problems when disposing of FBT.

In order to achieve the above object, the inventor conducted various studies on epoxy resin compositions and, as a result, added hydrated alumina powder and red phosphorus powder to the epoxy resin, and further added an acid anhydride curing agent 9 reaction accelerator. It became clear that things were good.

That is, in the present invention, in an epoxy varnish consisting of 100 parts by weight of an epoxy resin, an acid anhydride, and a reaction accelerator, the mixing amounts of hydrated alumina powder and red phosphorus powder with respect to 100 parts by weight of the epoxy resin are set at points A, B, and B in FIG. C, D・E, I”, G
, the viscosity of 25'C in the composition range surrounded by H is 2 to 7
The FBT obtained thereby is characterized by having a composition with zero voids, and (1) does not generate toxic gas even when FBT is burned.

(2) Magnet wires and electrodes will not corrode.

(3) FiF3T insulation can be safely performed.

(4) Workability is good because the pot life is long.

(5) Epoxy varnish has excellent dielectric properties and generates little heat due to dielectric loss of epoxy varnish during FBT operation, and has stable high voltage output characteristics.

(6) No problems will occur when disposing of FBT (0 It has the above advantages.

Next, we will explain the material used in the present invention: epoxy (
Considering the efficiency of insulation treatment work, δ1 fat should be liquid at 25°C, and even if hydrated alumina powder and red phosphorus powder are mixed as a hardening agent, the cured product will show good electrical properties. As such, acid anhydride compounds are good. Amine-based compounds are recommended as reaction accelerators (・ Hydrated alumina powder and red phosphorus powder are suitable for resin filling.Specifically, 100 parts by weight of epoxy resin and 1 part acid anhydride reaction accelerator) are used. The mixing ratio of hydrated alumina powder and red phosphorus powder to 100 parts by weight of epoxy resin in the epoxy varnish is determined at points A, B, C, D, E, and
An epoxy resin composition having a composition within the curved range of F.G.HVr is preferred. This is because if an FBT is insulated with an epoxy resin composition having a composition outside this range, the completed FBT will have insufficient flammability.
This is because the FBT coil is not sufficiently impregnated with the 1-oxy resin composition, making it impossible to provide void-free insulation, which may result in the FBT being destroyed by partial discharge.

Note that the viscosity of the epoxy resin composition within the above composition range at 25°C is 2 to 7 o voids. If the viscosity is less than 2 voids, the flame retardancy of the finished I"BT will be insufficient, and if it is greater than 7o voids, an I"BT with poor impregnation will be produced, both of which are unfavorable.

Next, the present invention will be explained in detail with reference to Examples. FIG. 1 shows an example of a cross-sectional view of an FBT. In other words, FBT is
The primary bobbin 5, the secondary bobbin 5, the primary coil 6 and the secondary coil 4 are assembled into the case 2, and after the high voltage lead wire 7 is completely pulled out from the secondary coil 4, the resin composition 1 for impregnation and coating formation is poured. It can be manufactured by shaping.

Epoxy resin compositions having the compositions shown in the composition columns of Examples 1 to 11 of Table 1 were applied upward to the coil portion of the FBT shown in Figure 1 at a flow rate of 2° to 30°C, a degree of vacuum of 2
Vacuum injection at ~4 HliHg at 60°C/4 h
The epoxy cast FBT was obtained by heating and curing at +105°C/7 hours. Epoxy cast FBT obtained in this way
A flame retardancy test was conducted based on the Electrical Parts Control Law by applying the oxidizing flame 9 of a gas burner 8 to the lower part of the case 2 as shown in Figure 2.
As shown in the characteristics and flame retardance column of FBT No. 1, all passed the test. The amount of smoke generated during combustion is shown in Table 2, Examples 1 to 11.
As shown in the F''BT characteristics and the amount of smoke generated during combustion, both were small.

Next, the epoxy cast FBT was cut as shown in Figure 1, and the impregnation of the epoxy resin and the presence or absence of voids in the coil were observed.
As shown in Table 2, Examples 1 to 110 FBT had good properties, impregnability, and presence/absence of voids in the coil.

Furthermore, an epoxy resin composition having the composition shown in the composition column of Examples 1 to 11 in Table 1 was prepared at 60° (:/4h+105°).
C/7h and examined for flammability, tracking resistance, and arc resistance. As shown in the properties column of the resin composition in Table 2, the flame retardancy was V-o, and the tracking resistance was Both are 600v or more, arc resistance 120-180
This was also good.

In addition, we investigated the dielectric properties of resin plates for 2-meter-thick doors produced by curing epoxy resin compositions having the compositions shown in the composition column of Example 1.2 in Table 1 under the conditions listed above. As shown in Example 1.2 in Table 6, good values were shown both at high temperatures and when absorbing moisture. Although not shown in Table 6, Examples 5 to 11 also showed good values as in Example 1.2. Although it was operated under temperature and humidity conditions, it maintained good characteristics for a long time.

Although not described in the examples, it is also possible to incorporate various additives into the epoxy resin composition of the present invention, such as antifoaming agents, voltage stabilizers, colorants, surfactants, etc. It is. In addition to the FBT method shown in Figure 1, there are also interlayer insulated ones with plastic films and diodes.

It can also be applied to FBTs that are miniaturized and multipurpose by connecting resistors, capacitors, etc. inside, use molds without using cases, and dip coat FBTs.

Comparative Example First, FBT cast with an epoxy resin composition having the composition shown in the composition column of Comparative Examples 1 and 5.6 in Table 4 has a small content of red phosphorus powder and hydrated alumina powder, so it is shown in Table 2. Comparative Examples 1 and 5. (Characteristics of FBT of S.

As shown in the flame retardance column, the flame resistance of FBT is less than 1 minute, and it does not pass the Electrical Appliance and Material Control Law. Table 5 Comparative Examples 2 and 3
．． T, F13'I', which is cast with a more fragile epoxy resin shown in the composition column of No. 4, has a large amount of hydrated alumina powder and red phosphorus powder, so it has no flame retardancy. 2
Although the FBT characteristics of Comparative Example 1.5.6 in the table show sufficient characteristics as shown in the flame retardance column, the resin composition has poor fluidity.
Because air entrainment occurs during injection and it is difficult for air to escape, the characteristics and impregnability of FBT of Comparative Example 2.3.4 in Table 2.

As shown in the table showing the presence or absence of voids in the coil, voids remain in the coil, making it impossible to obtain a long-life FBT. The epoxy resin composition shown in the composition column of Comparative Example 9 in Table 4 is the same as the composition of Example 4 in Table 1 ((The epoxy resin composition shown in IW), in which the hydrated alumina is replaced with silica powder. However, as shown in the characteristic flame retardance column of Comparative Example 9 FBT in Table 2, the FBT cast with this material had insufficient flame retardancy.

Furthermore, the epoxy resin composition shown in the composition column of Comparative Example 10 in Table 4 is a composition made flame retardant by the conventional method, that is, by blending a halogen thread flame retardant and antimony trioxide, but the epoxy resin composition shown in Table 2, FBT As shown in the combustible smoke generation column, a large amount of black smoke and toxic gas are generated when burned.
Also, compared to the epoxy resin compositions shown in the composition columns of Examples 1 to 4 in Table 1, which were cured at 60°C/4 hours + 105°C/7 hours, there were drawbacks such as inferior tracking resistance and arc resistance. This was not practical. Furthermore, the epoxy resin compositions shown in the composition column of Comparative Examples 7 and 8 in Table 4 are examples in which an amine compound is used as a curing agent, but as shown in Comparative Examples 7 and 8 in Table 6, The dielectric properties at the time of moisture absorption are poor, as shown in Table 2 Comparative Example 7.8 Characteristics of FBT, impregnability, presence of voids in the coil.
The impregnating properties were poor and 4ζ ids were generated within the II″B T′ coil.

As mentioned above in the margin below, according to the present invention, during FBT combustion,
It is possible to efficiently manufacture a long-life FBT that does not generate harmful gases, does not cause damage to magnet wires or electrodes, has excellent electrical performance, and does not cause problems when disposing of the FBT.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of FBT, Figure 2 is a diagram showing the FBT flame retardant test method based on the Electrical Appliance and Material Control Act, Separate Law No. 82 (94), and Figure 3 is a cross-sectional view of FBT. This figure shows the relationship between the amount of red phosphorous powder hydrated alumina blended into the epoxy resin composition for coating formation and FBT characteristics. 1...Resin composition for impregnation and coating formation Figure 1/Figure 3 (Amount to be added to Evo'' + Shizesu month/θO weight @fP)
Continuing from page 1 0 Inventor: 292 Yoshida-cho, Totsuka-ku, Yokohama City, Hitachi, Ltd. Production Technology Laboratory 0 Inventor: Tokio Isogu, 292 Yoshida-cho, Totsuka-ku, Yokohama City, Hitachi, Ltd. Production Written amendment of procedures within the Institute of Technology (method) Indication of the case Patent application No. 1158 (1982) Meeting+11
1. Correct the content as in the human correction.

Claims (1)

[Scope of Claims] In the epoxy varnish consisting of 100 parts by weight of epoxy resin, an acid anhydride, and a reaction accelerator, the amount of hydrated alumina powder and red phosphorus powder mixed with respect to 100 parts by weight of epoxy resin is the following points A, B, and C. , D, g, F, G, and H. However, points A, B, C, D, E, F, G, and H indicate the following composition: Hydrated alumina powder (parts by weight) Red phosphorus powder (parts by weight) A 72 50
B 85 20C
10310 D 220
4E 198
20F 178
Self 1G 154
40H11246