JP2007039543A - One part liquid epoxy resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an one part liquid epoxy resin composition, in a relay using PBT or LCP as a part of components, that is capable of curing at a temperature of ≤120°C, exercises superior adhesion between PBT or LCP and a metal terminal even in an environment of high temperature and high humidity, and moreover has improved adhesion to the metal terminal at a high temperature upon reflow soldering. <P>SOLUTION: This one part liquid epoxy resin composition comprises (A) an epoxy resin and, as latent curing agents, (B) dicyandiamide, (C) a dihydrazide compound and (D) an latent curing agent other than the dicyandiamide and the dihydrazide compound as essential components, wherein an amount of (B) is from 0.5 to 15 pts.wt. and the total amount of (B) and (C) is from 1 to 30 pts.wt. based on the epoxy resin of 100 pts.wt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a small electronic component or an electrical component, and more particularly to a one-pack type epoxy resin composition for hermetic sealing or insulation sealing of a relay.

Small electronic parts or electrical parts, especially relays, have been steadily increasing in production volume with the development of the electronics industry, and are used in various fields such as communication equipment, OA equipment, home appliances, and vending machines. In particular, the number of relays mounted on printed wiring boards is increasing. Its necessary characteristics include prevention of solder flux intrusion, the ability to wash components with solvent, and the ability to maintain airtightness after solder reflow processing, and there are an increasing number of completely hermetic sealed relays made of resin, etc. As a result, the reliability requirements are becoming stricter.

As described above, as the airtightness of the relay is strongly required, an excellent sealing material is required. Conventionally, as a sealing resin for such a purpose, an epoxy resin is used. It was used. The epoxy resin composition includes a so-called two-pack type epoxy resin composition in which a curing agent such as polyamidoamine or acid anhydride and an epoxy resin are mixed immediately before use, and dicyandiamide or the like as a latent curing agent in advance. There is a so-called one-pack type epoxy resin composition that is mixed with a resin composition.

In general, the disadvantages of the two-pack type epoxy resin composition include poor curing due to measurement errors at the time of blending and short pot life after blending. Moreover, when polyamidoamine, aliphatic amine, or the like is used as the curing agent, the heat resistance of the cured product is low, and airtight defects after passing through the solder bath after sealing often occur. Similarly, when an acid anhydride is used, there is a disadvantage that the curing temperature must be increased. Therefore, recently, there is a shift to a one-pack type epoxy resin composition with low material loss and high productivity. On the other hand, for such a one-pack type epoxy resin composition, durability in a high-temperature and high-humidity environment is also required due to diversification of the use environment of the relay, and an improvement in the performance of the sealant is required. . Since the constituent members of the relay are mainly plastic materials other than terminal materials, coils, magnets, etc., a curing temperature of 120 ° C. or less is desired. As a latent curing agent for a one-pack type epoxy resin composition, dicyandiamide, which is mainly used, is a compound having a high melting point, and unreacted substances may remain under the above-mentioned curing conditions, and the resulting cured product has heat resistance. Property and moisture resistance were not sufficient.

The inventors of the present invention have previously described that a resin composition containing 12-aminododecanoic acid and other latent curing agents as essential components can be cured at a temperature of 120 ° C. or less, and is a high-temperature and high-humidity environment (85 ° C. 85% It was found that a cured product having excellent adhesion with PBT or LCP and a metal terminal can be obtained even under (RH) (Patent Document 1). However, even when the resin composition is used, it cannot be said that the adhesion to a metal terminal at a high temperature (200 to 300 ° C.) in the solder reflow process is sufficient.

JP 2004-67963 A

The present invention is a relay having PBT or LCP as a part of a component, can be cured at a temperature of 120 ° C. or less, and has excellent adhesion between PBT or LCP and a metal terminal in a high temperature and high humidity environment. Furthermore, the present invention provides a one-component liquid epoxy resin composition that is improved in adhesion to a metal terminal at a high temperature in a solder reflow process.

As a result of intensive studies to solve the above problems, the present inventors have found (A) epoxy resin and latent curing agent as (B) dicyandiamide and (C) dihydrazide compound and (D) potential other than dicyandiamide and dihydrazide compound. A curing agent as an essential component, and the amount of (B) used is 0.5 to 15 parts by weight with respect to 100 parts by weight of the epoxy resin, and (B) and (C). Can be cured at a temperature of 120 ° C. or less by using a one-pack type epoxy resin composition that is 1 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin in total, and a high temperature and high humidity environment Excellent adhesion between PBT or LCP and metal terminal below, and further to PBT or LCP and metal terminal under high temperature in solder reflow processing It found that a cured product with improved for adhesion can be obtained, thereby completing the present invention.

The (A) epoxy resin used in the present invention is not particularly limited as long as it is an epoxy resin used in a one-pack type epoxy resin composition, but an epoxy resin used in an epoxy resin composition for relay sealing is preferable. . Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, dicyclo Examples thereof include a pentadiene type epoxy resin and a phenol novolac type epoxy resin, and these epoxy resins may be used alone or in combination. These epoxy resins may be liquid or solid at normal temperature, but are preferably liquid at normal temperature.

Examples of the (C) dihydrazide compound used in the present invention include carbohydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, Dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4'-bisbenzenedihydrazide, 1,4-naphthoic acid dihydrazide, and the like. Among these, succinic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide , Dihydrazide suberic acid, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide are preferred.

The amount of (B) dicyandiamide and (C) dihydrazide compound used in the present invention varies depending on the amount of the latent curing agent other than (D) dicyandiamide and dihydrazide compound to be used in combination, but with respect to 100 parts by weight of the epoxy resin, B) is 0.5 to 15 parts by weight, and (B) and (C) in total are 1 to 30 parts by weight, preferably 0.5 to 15 parts by weight, respectively. is there.

The latent curing agent other than (D) dicyandiamide and dihydrazide compound in the present invention is not particularly limited as long as it does not inhibit the performance after curing. For example, a tertiary amine compound, an imidazole compound, an imidazole adduct system Examples thereof include compounds, amine adduct compounds, modified aliphatic polyamine compounds, and preferably imidazole adduct compounds, amine adduct compounds, and modified aliphatic polyamine compounds are used. Examples of the tertiary amine compound include tris (dialkylaminoalkyl) phenol compounds represented by benzyldimethylamine and 2,4,6-tris (dimethylaminomethyl) phenol. Examples of the imidazole compound include 2-phenylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Examples of imidazole adduct compounds include Amicure PN-23 and Amicure PN-R manufactured by Ajinomoto Techno Fine Co., and examples of amine adduct compounds include Amicure MY-24 and Amicure MY- manufactured by Ajinomoto Techno Fine Co., Ltd. R and adduct compounds disclosed in JP-A-57-100127, and the modified aliphatic polyamine compound includes, for example, Fuji Cure FXE-1000 manufactured by Fuji Kasei Kogyo Co., Ltd.

(D) In the present invention, at least one latent curing agent other than dicyandiamide and dihydrazide compound may be contained, and the amount used varies depending on the type of latent curing agent and the amount of dihydrazide compound or dicyandiamide used. However, it is usually 0.5 to 30 parts by weight, preferably 3 to 20 parts by weight, based on 100 parts by weight of the epoxy resin.

The one-pack type liquid epoxy resin composition of the present invention can be blended with an inorganic filler, a coupling agent, a colorant and the like as required. Examples of the inorganic filler include calcium carbonate, barium sulfate, fused silica, crystalline silica, glass filler, aluminum hydroxide, magnesium hydroxide, and alumina. Examples of the coupling agent include 3-glycidoxypropyl. Examples include trimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane, and examples of the colorant include carbon black and titanium oxide.

In the preparation method of the one-pack type epoxy resin composition of the present invention, a general stirring and mixing apparatus and mixing conditions are applied in the same manner as the preparation method of a normal epoxy resin composition. Examples of the apparatus used include a mixing roll, a dissolver, a planetary mixer, a kneader, and an extruder. As mixing conditions, epoxy resin or the like may be dissolved and / or reduced in viscosity, and heated to improve stirring and mixing efficiency. Moreover, in order to remove frictional heat generation, reaction heat generation, etc., you may cool as needed. The time for stirring and mixing may be determined if necessary, and is not particularly limited.

By using the one-pack type epoxy resin composition of the present invention, it can be cured at a temperature of 120 ° C. or less, and has excellent adhesion between PBT or LCP and a metal terminal in a high-temperature and high-humidity environment. A cured product having improved adhesion to PBT or LCP and a metal terminal at a high temperature in the reflow process is obtained.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

After mixing 100 parts by weight of epoxy resin, 1 part by weight of dicyandiamide, 1 part by weight of adipic acid dihydrazide (ADH) as a dihydrazide compound, 10 parts by weight of curing agent A, and 1 part by weight of Aerosil 200, the mixture is kneaded using a mixing roll. Type epoxy resin composition was prepared. The obtained one-pack type epoxy resin composition was applied to copper (1.6 × 25 × 100 mm) and LCP (2 × 25 × 100 mm) as adherends and cured at 100 ° C. for 60 minutes to prepare a test piece. did. Copper-copper adhesive strength and LCP-LCP adhesion immediately after creation and after exposure for 10 minutes in a 270 ° C hot air circulating thermostatic chamber or for 500 hours in an 85 ° C 85% RH constant temperature and humidity chamber The force was measured in accordance with the method for measuring tensile shear bond strength in JIS K6850, and the results were determined according to the criteria shown below.
Copper-copper adhesion (MPa):
×: Less than 10, ○: 10 or more LCP-LCP adhesive strength (MPa):
×: Less than 1.0, ○: 1.0 to 2.0, ◎: More than 2.0

(Examples 2-5 and Comparative Examples 1-2)
Tables 1 and 2 show the results of physical property tests and determinations on the epoxy resin compositions prepared in the same manner as in Example 1 at the ratios shown in Tables 1 and 2.

Ｄ．Ｅ．Ｒ．３３１Ｊ：ビスフェノールＡ型エポキシ樹脂
（ダウ・ケミカルジャパン社製）
ＡＤＨ ：アジピン酸ジヒドラジド
硬化剤Ａ ：ジメチルアミンのエポキシ樹脂アダクト硬化剤
アエロジル ２００ （日本アエロジル社製）

D. E. R. 331J: Bisphenol A type epoxy resin (manufactured by Dow Chemical Japan)
ADH: adipic acid dihydrazide curing agent A: dimethylamine epoxy resin adduct curing agent Aerosil 200 (Nippon Aerosil Co., Ltd.)

Claims (3)

An epoxy resin composition for hermetically sealing or insulatingly sealing small electronic components or electrical components, wherein (A) epoxy resin, (B) dicyandiamide, (C) dihydrazide compound, and (D) dicyandiamide and dihydrazide compound A curing curing agent as an essential component, and the amount of (B) used is 0.5 to 15 parts by weight with respect to 100 parts by weight of the epoxy resin, and (B) and (C). The one-pack type epoxy resin composition characterized by being used in a total amount of 1 to 30 parts by weight per 100 parts by weight of the epoxy resin. The one-component epoxy resin composition according to claim 1, wherein (D) is at least one selected from the group consisting of imidazole adduct compounds, amine adduct compounds, and modified aliphatic polyamine compounds. The one-pack type epoxy resin composition according to claim 1, wherein the small electronic component or the electric component is a relay.