JP2000226439A - Flame-retarded epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition showing excellent flame retardancy and electrical reliability in spite of containing no substance adding a load to the environment by compounding an epoxy resin with a triazine-ring- containing phenolic curing agent with an inorganic filler, an inorganic ion exchanger, and a cure accelerator. SOLUTION: The epoxy resin used is desirably a bisphenol epoxy resin or cresol novolak epoxy resin. The epoxy resin content is as high as about 20-50 wt.% based on the composition. The triazine-ring-containing phenolic curing agent used is desirably a phenolic novolak resin having at least two phenoitc hydroxyl groups in the molecule, having triazine rings in the molecular structure, and represented by the formula. The inorganic ion exchanger used is desirably an anion exchanger. The composition is obtained by compounding 100 pts.wt. epoxy resin with about 35 to 80 pts.wt. triazine-ring-containing phenolic curing agent, about 60-300 pts.wt. inorganic filler, about 60-300 pts.wt. inorganic exchanger, and about 0.3-4 pts.wt. cure accelerator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant epoxy resin composition particularly useful for electrical insulation and containing no halogen or antimony.

[0002]

2. Description of the Related Art For the purpose of an epoxy resin composition used for insulating coating of capacitors and coils, it is important not only to maintain insulation properties but also to impart flame retardancy.

[0003] Therefore, conventionally, a halogen compound is added, an epoxy resin having a halogen atom in a molecule and an antimony compound are used in combination, or a phosphorus compound is used as a flame retardant.

While these compounds exhibit good flame retardancy, they emit harmful gases such as harmful hydrogen halides during combustion. In addition, the use of halogen-based flame retardants suspected of generating dioxins and antimony compounds that have been pointed out as having carcinogenic potential tends to be suppressed. In response to such a tendency, various alternative flame retardants have been studied.

However, for example, when a metal hydrate is used, it must be added in a large amount in order to exhibit sufficient flame retardancy, and there is a problem in the curability of the resin and the strength of the cured product. In addition, conventional nitrogen-containing flame-retardant systems have electrical reliability when mounted as electronic components (especially moisture-resistant electrical characteristics).
And it cannot withstand practical demands for sealing electronic components.

[0006]

SUMMARY OF THE INVENTION The present invention provides a flame-retardant epoxy resin composition which does not contain any environmentally harmful substances such as halogen compounds, phosphorus compounds and antimony compounds and has excellent flame retardancy and electrical reliability. The purpose is to do.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object and found that epoxy resin,
The present inventors have found that an epoxy resin composition containing a triazine ring-containing phenolic curing agent, an inorganic filler, an inorganic ion exchanger, and a curing accelerator has excellent flame retardancy, electrical insulation properties, and moisture resistance reliability. Completed the invention.

That is, the present invention provides an epoxy resin composition and an electronic component as described below.

1. (A) an epoxy resin, (B) a triazine ring-containing phenolic curing agent, (C) an inorganic filler,
An epoxy resin composition comprising (D) an inorganic ion exchanger and (E) a curing accelerator.

[0010] 2. Item 2. An electronic component coated with the epoxy resin composition according to Item 1.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin composition of the present invention comprises:
It contains (A) an epoxy resin, (B) a triazine ring-containing phenol-based curing agent, (C) an inorganic filler, (D) an inorganic ion exchanger, and (E) a curing accelerator as essential components. Other components (for example, a surface modifier, a coupling agent, a flowing agent, a pigment, a carnauba wax, a laser mark coloring agent, a flame retardant auxiliary, etc.) are contained within a range not inconsistent with the object of the present invention. Can be.

(A) Epoxy resin As the epoxy resin, it is preferable to use an epoxy resin having two or more epoxy groups in one molecule. Examples of such an epoxy resin include a bisphenol-type epoxy resin, a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, and a triphenolmethane-type epoxy resin. Preferred epoxy resins are bisphenol type epoxy resin, cresol novolak type epoxy resin and the like. As the epoxy resin, one type may be used alone, or two or more types may be used in combination. It is preferable that the type and ratio of the epoxy resin are appropriately adjusted and used depending on the intended use of the epoxy resin composition. For example, when a high glass transition temperature is required for the cured product, it is preferable to increase the proportion of the cresol novolac epoxy resin.

The content of the epoxy resin in the epoxy resin composition is about 20 to 50% by weight, preferably 30 to 40% by weight.
% By weight.

(B) Curing agent As the curing agent, a triazine ring-containing phenolic curing agent is used as an essential curing agent. The triazine ring-containing phenolic curing agent is useful for imparting flame retardancy to the epoxy resin composition. The triazine ring-containing phenolic curing agent has two or more phenolic hydroxyl groups in one molecule, and preferably has an average hydroxyl equivalent of 100 to 350, and more preferably 110 to 250.

Examples of such a triazine ring-containing phenolic curing agent include, for example, those of the formula

[0016]

Embedded image

A phenol novolak resin having two or more phenolic hydroxyl groups in one molecule and having a triazine ring in the molecular structure is preferable.

[0018] The triazine ring-containing phenolic curing agent is
For example, it can be obtained by reacting melamine, phenol and formaldehyde. In addition, the amount of nitrogen may be adjusted using benzoguanamine.

The amount of the triazine ring-containing phenolic curing agent used is from 35 to 8 per 100 parts by weight of the epoxy resin.
It can be about 0 parts by weight, preferably about 45 to 60 parts by weight.

As the curing agent, a curing agent having a phenolic hydroxyl group such as a phenol novolak resin, bisphenol A and bisphenol F may be used together with the above-mentioned triazine ring-containing phenol curing agent. Further, an acid anhydride-based curing agent may be used in combination. Known acid anhydride-based curing agents such as trimellitic anhydride and pyromellitic anhydride can be widely used.

The mixing ratio of the curing agent to the epoxy resin is as follows.
Approximately 1.2, more preferably approximately 0.8 to 1.0. That is, the ratio of the number of functional groups in the entire curing agent to the number of epoxy groups in the entire epoxy resin (the number of functional groups / the number of epoxy groups) is about 0.7 to 1.2, and further 0.8 to 1.0.
It is preferable that the blending amount is set so as to fall within the range of the degree. When the amount is within this range, the ability in physical strength and electrical properties can be maximized.

(C) Inorganic filler As the inorganic filler, any known inorganic filler can be used. Examples of the inorganic filler include fused silica powder, spherical fused silica powder, crystalline silica powder, magnesia hydrate, alumina hydrate, talc, calcium carbonate and the like.

Considering the flame retardancy, metal oxide hydrates such as magnesia hydrate and alumina hydrate are preferred. On the other hand, in fields where solder cracking properties and heat cycle properties are regarded as important, other inorganic fillers can be used.
Various inorganic fillers can be used in combination depending on the use of the epoxy resin composition.

The amount of the inorganic filler used is 10
The amount can be about 60 to 300 parts by weight, preferably about 100 to 220 parts by weight, based on 0 parts by weight.

In a preferred embodiment, the content of the inorganic filler in the epoxy resin composition is about 30 to 70% by weight, preferably 40 to 60, from the viewpoint of fluidity and melt viscosity.
% By weight. When it is below this range, the water absorption tends to be large and the physical properties tend to be inferior. On the other hand, when it exceeds this range, the fluidity tends to be poor, adversely affecting the moldability and causing poor appearance.

(D) Inorganic ion exchanger The epoxy resin composition of the present invention contains an inorganic ion exchanger as a moisture resistance improver.

An inorganic ion exchanger is a compound having -O
It is an inorganic ion-exchange substance having an H group, and examples thereof include an inorganic anion exchanger, an inorganic cation exchanger, and an inorganic zwitterion exchanger. These inorganic ion exchangers are composed of, for example, a polyvalent metal acid, a salt thereof, and a polyvalent metal hydrate.

The inorganic ion exchanger preferably has a total ion exchange capacity of 1 to 10 meq / g, more preferably 3 to 7 meq / g.

To determine the ion exchange capacity, for example,
In the case of chlorine ion exchange capacity, the inorganic ion exchanger 1
g of 0.1N-HCl / 0.1N-NaCl mixed solution 5
After adding to 0 ml and shaking and stirring for 24 hours, it can be determined by measuring the chloride ion concentration and pH in the solution. Further, for example, when obtaining the exchange capacity of sodium ions, 0.5 g of the inorganic ion exchanger is added to 0.1 N-NaOH /
After adding to 50 ml of a 0.1N-NaCl mixed solution and stirring for 24 hours, it can be determined by measuring the sodium ion concentration and pH in the liquid.

Examples of the inorganic ion exchanger include anion exchangers such as aluminum, zirconium and magnesium-aluminum; cation exchangers such as zirconium and titanium; and both ion exchangers such as calcium. However, the use of an anion exchanger is preferred. Among the anion exchangers, the use of a magnesium-aluminum system is most effective.

The amount of the inorganic ion exchanger used can be about 0.01 to 5 parts by weight, preferably about 0.5 to 3 parts by weight, based on 100 parts by weight of the epoxy resin. If the ratio is less than the above range, it tends to be difficult to prevent the deterioration of the electric characteristics at the time of moisture resistance. On the other hand, if it exceeds this range, the physical properties of the cured product tend to decrease.

(E) Curing accelerator As the curing accelerator, for example, a widely used known curing accelerator such as imidazole, modified imidazole, tertiary amine, triphenylphosphine, diazabicycloundecene and the like can be used. The seeds may be used alone, or two or more kinds may be used in combination. Preferred curing accelerators are
Imidazole, modified imidazole, and triphenylphosphine.

The amount of the curing accelerator used is 10
The amount can be about 0.3 to 4 parts by weight, preferably about 1.5 to 3 parts by weight, based on 0 parts by weight.

The epoxy resin composition of the present invention may contain, if necessary, auxiliary components such as a surface modifier, a coupling agent, a flow agent, a pigment, a carnauba wax, a laser mark coloring agent, and a flame retardant auxiliary. May be added.

The epoxy resin composition of the present invention can be produced by a general production method using a general production facility. For example, it can be manufactured only by performing vacuum defoaming after mixing with a roll or mixing with a mixer such as a planetary mixer. Even when the epoxy resin composition of the present invention is manufactured as a powder coating, it can be manufactured by a general manufacturing method. For example, the respective components may be mixed and stirred by a mixer or the like, and may be melt-mixed and stirred by an extrusion melt-kneading stirrer or the like.

The epoxy resin composition of the present invention is excellent in flame retardancy as compared with conventional flame-retardant epoxy resin compositions without containing a halogen-based flame retardant, a phosphorus-based flame retardant, an antimony-based flame retardant and the like. It has excellent electrical insulation properties and moisture resistance reliability.

The epoxy resin composition of the present invention is suitable for applications such as a semiconductor encapsulant and an insulating material for electronic parts, particularly when used as a powder coating. The epoxy resin composition of the present invention is, for example, a flame-retardant composition for insulation sealing particularly suitable as a paint used for painting ceramic capacitors, film capacitors, resistance networks, coils and the like.

In order to coat an electronic part with the epoxy resin composition of the present invention, for example, the electronic part is coated with 100 to 12 parts.
After preheating to about 0 ° C. and coating the powder epoxy resin composition on the powder using a fluid dipping method powder coating machine,
What is necessary is just to carry out main hardening at about 50 degreeC.

[0039]

The present invention will be described more specifically with reference to the following examples.

Examples 1 to 6 A mixture having the composition (parts by weight) shown in Table 1 was mixed and stirred by a mixer, melt-mixed and stirred by an extrusion melt-kneading stirrer, and the obtained mixture was cooled and solidified, and then cooled by a pulverizer. It was pulverized and subjected to a classification treatment to obtain an epoxy resin composition.

The epoxy resin and the curing agent have an equivalent weight of 1:
The ratio was unified so as to be 1, and the blending amount of the inorganic filler (hydrated alumina, fused silica) was equal to the total amount of the epoxy resin and the curing agent.

The details of each component are as follows.

Bisphenol A type epoxy resin (A): manufactured by Yuka Shell Epoxy Co., Ltd., epicoat 1
002 Epoxy resin other than (A) (cresol novolak type epoxy resin): manufactured by Yuka Shell Epoxy Co., Ltd., epicoat 180S65. Triazine ring-containing phenolic resin (B): manufactured by Dainippon Ink Co., Ltd., trade name: KA-7055. Average hydroxyl equivalent 220 • Phenolic resin other than (B) (phenol novolak type resin): TD-2131 manufactured by Dainippon Ink Co., Ltd. Acid anhydride curing agent (benzophenone tetradicarboxylic anhydride): manufactured by Alco, Inc. BTDA-Hydrated alumina: manufactured by Showa Denko KK, trade name H-31-Fused silica: manufactured by Tatsumori, trade name RD-8-Curing accelerator (triphenylphosphine): manufactured by C-I Kasei Corporation, trade name: PP- 360-Inorganic ion exchanger: IX-7, manufactured by Toagosei Co., Ltd.
00, Cl ^- Total exchange capacity 4.3 meq / g-Silane coupling agent: manufactured by Chisso Corp., trade name: SILAACE S-510-Surface modifier: manufactured by Kyoei Chemical Co., trade name: Miki Leveling M
K-conc ・ Carbon black: manufactured by Mitsubishi Chemical Corporation, trade name MA-10
0.

Various properties of these epoxy resin compositions were evaluated as follows. Table 1 shows the results.

Flame retardancy test A test piece having a thickness of 1.0 mm was prepared by curing the UL-94 resin composition, and the flame retardancy of the cured product was determined under the test conditions specified in the UL-94 flame retardancy standard. Was tested. V-0 indicates that the flame retardant level has been cleared, and HB indicates that the flame retardant level has not been cleared.

Moisture resistance test The film capacitor element was put into a circulation type thermostatic bath manufactured by Tabai Espec Co., set at 100 ° C., and was preheated for 60 minutes. Coating was performed using a powder coating machine. The coating thickness of the resin composition was set to 0.6 to 0.8 mm on one side. This painted film capacitor is placed in the above-mentioned constant temperature bath for 1 hour.
The main curing was performed at 20 ° C./90 minutes. The obtained film capacitor was left in a constant temperature and humidity chamber of 85 ° C./85% RH, and the dielectric loss tangent of the capacitor after 1500 hours was measured. The smaller this value, the better the insulating material for electronic components.

Comparative Examples 1 to 5 A mixture having the composition (parts by weight) shown in Table 2 was treated in the same manner as in Examples 1 to 6, to obtain an epoxy resin composition. Various properties of these epoxy resin compositions were evaluated in the same manner as in Examples 1 to 6. Table 2 shows the results.

The compositions of Comparative Examples 4 and 5 contain environmentally harmful substances (phosphorus, halogenated compounds, antimony trioxide, etc.), as is apparent from the components.

[0049]

[Table 1]

[0050]

[Table 2]

As is clear from Tables 1 and 2, the epoxy resin composition of the present invention exhibited excellent flame retardancy and moisture resistance.

[0052]

The epoxy resin composition of the present invention can be compared with conventional flame-retardant epoxy resin compositions without containing environmentally hazardous substances such as halogen-based flame retardants, phosphorus-based flame retardants and antimony-based flame retardants. In addition, it exhibits excellent flame retardancy, and has excellent electrical insulation properties and moisture resistance reliability.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Ueno 3-5-1 Doumachi, Takatsuki City, Osaka Prefecture Inside (72) Inventor Kenichi Ueno 3-5-1 Doumachi, Takatsuki City, Osaka Sanyure Jin F term in the company (reference) 4J002 CD051 CD061 CD071 DE077 DE098 DE147 DE188 DE237 DJ017 DJ047 EN009 EU099 EU119 EU186 EW019 FD017 FD146 FD159 GQ01 4J036 AA01 AD01 AF06 DC45 FA01 FA05 JA07

Claims (2)

[Claims] 1. An epoxy resin, (B) a phenolic curing agent containing a triazine ring, (C) an inorganic filler, and (D) an epoxy resin.
An epoxy resin composition comprising an inorganic ion exchanger and (E) a curing accelerator. 2. An electronic component coated with the epoxy resin composition according to claim 1.