JP2006199818A - One-pack liquid epoxy resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-pack liquid epoxy resin composition curable at ≤120°C in a relay produced by using PBT as a part of the constituent part, and having excellent adhesiveness to PBT and metal terminals under a hot and humid environment and improved adhesiveness to metal terminals at a high temperature in a solder reflow treatment. <P>SOLUTION: The one-pack epoxy resin composition contains (A) an epoxy resin and latent curing agents comprising (B) dicyandiamide, (C) 12-aminododecanoic acid and (D) a latent curing agent except for dicyandiamide and 12-aminododecanoic acid, as essential components. The amount of the component (B) is 0.5-15 pts.wt. based on 100 pts.wt. of the epoxy resin and the sum of the components (B) and (C) is 1-30 pts.wt. based on 100 pts.wt. of the epoxy resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 components or electrical components, particularly relays, have been steadily increasing in production with the development of the electronics industry, and are used in a wide variety of 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 penetration, solvent cleaning of parts, and airtightness after solder reflow treatment, etc., and the number of completely hermetically sealed relays made of resin and the like has increased. 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 drawback that the curing temperature must be increased. Therefore, recently, there has been a shift to a one-component 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.

Moreover, about using 12-aminododecanoic acid as a latent curing agent for one-pack type epoxy resins, when an aminocarboxylic acid having a specific structure containing 12-aminododecanoic acid is used as a latent curing agent for epoxy resins. It is described that pot life and gelation time are improved (Patent Document 1). However, in this method, the gelation temperature is as high as 150 to 160 ° C., and it is a condition for use in small-sized electronic parts or electrical parts, which is the object of the present invention, more specifically, for airtight sealing or insulating sealing of relays. If the curing temperature is 120 ° C. or lower, sufficient performance cannot be obtained. Furthermore, by using 12-aminododecanoic acid and other latent curing agents as essential components, it can be cured at a temperature of 120 ° C. or lower, and PBT or LCP and even under a high temperature and high humidity environment (85 ° C. and 85% RH) It is described that a cured product having excellent adhesion to a metal terminal can be obtained (Patent Document 2). However, the adhesiveness to the metal terminal at high temperature (200 to 300 ° C.) in the solder reflow process was not sufficient.

JP-A-57-98522

JP 2004-67963 A

The present invention is a relay in which PBT is a part of a constituent member, can be cured at a temperature of 120 ° C. or less, has excellent adhesion between PBT and a metal terminal in a high temperature and high humidity environment, and further solder reflow. It is an object of the present invention to provide a one-component liquid epoxy resin composition that is improved in adhesion to a metal terminal under high temperature during processing.

As a result of intensive studies to solve the above problems, the present inventors have found that (B) dicyandiamide and (C) 12-aminododecanoic acid and (D) dicyandiamide and 12- A latent curing agent other than aminododecanoic acid is contained 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) are used in total, and cured at a temperature of 120 ° C. or lower 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. Possible to cure with excellent adhesion between PBT and metal terminal under high temperature and humidity environment, and improved adhesion to metal terminal under high temperature in solder reflow process It found that to obtain, 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 compound conventionally used in a one-pack type epoxy resin composition, preferably an epoxy resin composition for relay sealing. Can do. 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.

The amount of (B) dicyandiamide and (C) 12-aminododecanoic acid used in the present invention varies depending on the amount of the latent curing agent other than (D) dicyandiamide and 12-aminododecanoic acid used in combination, but the weight of epoxy resin is 100 weight. Part (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 parts by weight, respectively. Part to 15 parts by weight.

The latent curing agent other than (D) dicyandiamide and 12-aminododecanoic acid in the present invention is not particularly limited as long as it does not hinder the performance after curing. For example, a tertiary amine compound, an imidazole compound, Examples include imidazole adduct compounds, amine adduct compounds, and modified aliphatic polyamine compounds. 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.

The latent curing agent other than (D) dicyandiamide and 12-aminododecanoic acid in the present invention may be contained at least one kind, and the amount used thereof is the type of latent curing agent, 12-aminododecanoic acid or dicyandiamide. The amount 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 in order to improve stirring and mixing efficiency. Further, cooling may be performed as necessary in order to remove frictional heat generation, reaction heat generation, and the like. 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, has excellent adhesion between the PBT and the metal terminal in a high-temperature and high-humidity environment, and further, solder reflow treatment The hardened | cured material improved about the adhesiveness to the metal terminal in the high temperature in is obtained.
(Example)

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

100 parts by weight of epoxy resin, 10 parts by weight of dicyandiamide, 5 parts by weight of 12-aminododecanoic acid, 10 parts by weight of curing agent A, and 1 part by weight of Aerosil 200 are mixed and then kneaded using a mixing roll to form a one-pack type epoxy resin composition A product was prepared. The obtained one-pack type epoxy resin composition was applied to copper (1.6 × 25 × 100 mm) and PBT (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 PBT-PBT adhesion immediately after creation and after exposure for 10 minutes in a 250 ° C hot air circulating thermostat or for 500 hours in an 85 ° C 85% RH constant temperature and humidity bath 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.
Steel-steel adhesion (MPa):
×: Less than 10, ○: 10 or more PBT-PBT and LCP-LCP adhesive strength (MPa):
×: Less than 1, ○: 1-3, ◎: 3 or more

(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 Table 1.

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）

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)

Curing agent A: Epoxy resin adduct curing agent of dimethylamine

Aerosil 200 (Made by Aerosil Japan)

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) 12-aminododecanoic acid and (D) dicyandiamide and 12- A latent curing agent other than aminododecanoic acid is contained 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 ( A one-component epoxy resin composition characterized in that the total amount of B) and (C) used is 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.