JPH0250129B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for curing polyepoxy resin. The polyepoxy resin cured by the method of the present invention has a remarkable effect of preventing migration of gold, silver, copper, etc. constituting wiring circuits. board and organic,
It is considered to be particularly useful in the field of manufacturing coating materials for inorganic substrates. (Prior art) Epoxy resin has excellent heat resistance, electrical insulation, and adhesive properties, so it has traditionally been widely used as a sealing material, insulating material, and substrate matrix material, especially in the fields of electronic components and printed circuit boards. I've been However, epoxy resin has a low ability to prevent migration, a phenomenon in which the metal constituting the wiring or electrode on the insulating material migrates on the insulating material due to the action of potential difference in a high humidity environment, resulting in poor insulation. Alternatively, problems such as short circuits may occur. (Problems to be Solved by the Invention) As the miniaturization and density of components and the miniaturization of wiring circuits progress, prevention of migration, in particular, has been increasingly required within the industry. Various commercially available resins aimed at preventing migration have flaws such as harsh curing conditions, large curing shrinkage, and low adhesion, and are not necessarily in a satisfactory state. . Furthermore, although the glass frit used in ceramic substrates has an excellent anti-migration effect, it is expensive and has drawbacks such as a high baking temperature. (Means for Solving the Problems) In view of the above circumstances, the present inventors have conducted intensive research and found that 2-phenyl-4-methyl-5, which is represented by the following formula, is an essential component of polyepoxy resin.
-Benzylimidazole (hereinafter abbreviated as 2P4M5BZ)

The present invention was completed based on the discovery that by adding the following formula, a cured product having high heat resistance, insulation properties, and adhesion properties and excellent anti-migration properties can be produced. 2P4M5BZ contains 1 mole of 2-phenyl-4-methylmidazole and more than the same mole of benzyl chloride.
It is synthesized by heating at 300 to 320°C for several hours. In that case, a small amount of potassium iodide may be added to the reaction system in order to promote the reaction. When 2P4M5BZ is used as a curing agent for polyepoxy resin, the cured product has excellent boiling absorption rate and electrical properties, and has migration prevention effects. The polyepoxy resin in the present invention contains an average of one or more epoxy groups per molecule, and this group is located at the terminal position of the molecule.

[Formula] may be used, or there may be an intervention in the middle of the molecule. exist

It may also be constructed in the form [Formula]. The polyepoxy compound may be aliphatic, cycloaliphatic, aromatic, or heterocyclic and may contain non-interfering substitutions such as hydroxyl, alkyl, alkoxy, ester, acetal, or ether groups. It may be substituted with a group. Typical polyepoxy resins suitable for the practice of the present invention include polyglycidyl ethers of polyhydric phenols, such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, other epoxidized phenolic novolac resins, alicyclic These include epoxy resins and their brominated epoxy resins. Added to polyepoxy resin
The amount of 2P4M5BZ is preferably 3 to 5 parts by weight per 100 parts by weight of the polyepoxy resin. The curing conditions for the polyepoxy resin may need to be changed somewhat depending on the amount of resin and curing agent added, but it is usually best to heat the resin at a temperature of 100 to 150° C. for a maximum of 8 hours. Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. Examples 1 and 2 7 and 10 parts by weight of 2P4M5BZ and 3 parts by weight of a viscosity modifier (product name: Erosil # 300, (manufactured by Nippon Aerosil) and mixed in a three-roll mill.
After defoaming, it was poured between two glass plates prepared to have a thickness of 3 mm, and cured at 100℃ for 4 hours and 150℃ for 4 hours, and the glass transition temperature, boiling absorption rate, and electrical properties of the cured product were determined. When measured, the boiling absorption rate and electrical properties were found to be very excellent. The test results are shown in Table 1.

【table】

[Table] Examples 3 to 4 100 to 15 parts by weight of 2P4M5BZ and 5 as essential components to 100 parts by weight of polyepoxy resin (trade name: Epicoat #828, manufactured by Yuka Ciel Epoxy)
Parts by weight of viscosity modifier (trade name: Erosil #300,
(manufactured by Nippon Aerosil) and mixed in a three-roll mill to prepare various polyepoxy resin formulations, and the gel time of each formulation at a temperature of 150℃ and heating at a temperature of 150℃ for 15 minutes. A migration resistance test of the cured coating film was conducted. The results of these tests are shown in Table 2, and the formulation containing 2P4M5BZ showed migration resistance for more than 1500 hours, while the formulation that did not contain 2P4M5BZ showed migration resistance for only 48 hours or less. Ta.

【table】

Claims (1)

[Claims] 1. A polyepoxy resin characterized in that 2-phenyl-4-methyl-5-benzylimidazole represented by the following formula is added to a polyepoxy resin and heated. Curing method.