JPH0377211B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to an epoxy resin composition that has excellent mold releasability and imprinting properties and is free from mold stains, and its feature is that a silicone compound having an epoxy group is reacted with a resin component and fixed. There it is. Recently, the field of electrical and electronic equipment has made remarkable progress, and the use of plastic parts in particular has become commonplace. If these plastic parts are molded products,
Molded products are obtained by hardening (thermosetting) or cooling (thermoplastic) phenolic resin, epoxy resin, etc. in a mold by compression molding, transfer molding, or injection molding. What is required in this molding process, particularly in the molding process of thermosetting resins, is good mold releasability and no staining of the mold. Generally, during mold release, the release agent oozes out from the molded product and forms a release agent film between the molded product and the mold, which eliminates the adhesive force between the mold and the molded product and makes it easier for both to release. can leave. Therefore, the amount of mold release agent that migrates and orients to the mold increases in proportion to the number of molding shots, and this is subjected to thermal history and seizes on the mold, resulting in mold fogging and mold staining. That is, good mold release and little mold staining are contradictory to each other. In addition, for IC parts, etc., molded products are marked (stamped) to distinguish between good and bad products. At this time, if the mold release agent forms a film on the surface of the molded product, problems such as poor ink adhesion and easy peeling of the mark may occur. For this reason, molding and assembling manufacturers are dealing with this by incorporating a degreasing process using a solvent or the like into the post-molding process. However, if the mold release agent deteriorates due to oxidation or the like, degreasing becomes incomplete and marking properties deteriorate, so a molding material with good marking properties is desired. This imprinting property is also a property that is contradictory to mold releasability. Therefore, a molding material with good mold releasability and imprinting properties and less mold staining has not become a reality. The present invention provides an epoxy resin composition that has good mold releasability and stamping properties and is free from mold stains. The gist of the present invention is to combine a phenol novolac and an organopolysiloxane having at least one epoxy group, if necessary, in a tertiary amine or its derivative, an organic phosphine compound, or an organic aluminum compound. This is an epoxy resin composition prepared by adding a random copolymer obtained by heating and melting to an epoxy resin in the presence of one or more selected from the following. Phenol novolacs here refer to all those containing a phenolic hydroxyl group or its derivatives in the novolac skeleton, and are not only single-component novolacs of phenols (phenols, alkylphenols, resorcinols, etc.), but also any phenolic novolacs. It also includes co-condensed (multi-component) novolacs formed by combinations of phenols and other resins. Furthermore, the organopolysiloxane having at least one epoxy group refers to all organopolysiloxanes having one or more epoxy group in the molecule, and is exemplified in, for example, JP-A-50-39345. An epoxy-functional polysiloxane polymer obtained by reacting with a cyclic organopolysiloxane, or as exemplified in JP-A-52-24258. etc. Furthermore, examples of reaction catalysts include tertiary amines and their derivatives, trimethylamine, triethylamine, 2,
3, 4, 6, 7, 8, 9, 10 - octahydropyramide (1, 2-a) azepine, etc. and quaternary ammonium salts thereof Organic phosphine compounds (a) Primary, secondary, and tertiary phosphine : Octylphosphine, butylphenylphosphine, tricyclohexylphosphine, triphenylphosphine, etc. (b) Petaine type adduct of organic tertiary phosphine and a compound having a π bond: maleic anhydride-triphenylphosphine adduct , thioisocyanate-triphenylphosphine adduct, diazodiphenylmethane-triphenylphosphine adduct, etc. (c) Organic phosphonium salt [∫ ₃ PCH ₂ ∫] CI, [∫ ₃ PEt] I,
[∫ ₃ PEt] Br etc. Organoaluminium compound substance (a) Al (OR) ₃ R: Hydrogen, alkyl group, aryl group, aryl group-containing hydrocarbon, (Example) Aluminum isopropoxide, aluminum n-poxide, aluminum tert
-ptoxide, aluminum pec-butyrate, aluminum benzoate, etc. (b) β-diketone complex of aluminum (aluminum chelate) Aluminum acetylacetonate, aluminum trifluoroacetylacetonate, aluminum pentafluoroacetylacetonate, etc. can be mentioned. The present invention relates to a random copolymer (hereinafter referred to as a mold release resin) obtained by heating and melt-mixing a phenol novolac with an organopolysilohexane having at least one epoxy group in the presence of a catalyst. A mold release resin is obtained by reacting a silicone compound with excellent mold release properties with a resin component (phenol novolacs), and an epoxy resin composition using this mold release resin has excellent mold release properties, marking properties, and mold stain resistance. It was discovered that it has the following characteristics. By fixing a silicone compound with excellent mold release properties to phenol novolacs that can react with various substances, a mold release resin that is effective in mold release and does not easily elute to the outside of the resin can be obtained. By using this method, it has become possible to create an epoxy resin composition with excellent mold releasability, imprintability, and mold stain resistance. The present invention uses a modified epoxy resin curing agent and a general-purpose silicone compound to provide a completely new epoxy resin composition that is highly versatile, industrially applicable, and has good mold releasability. Incidentally, as the ratio of silicone compound/phenol novolak in the mold release resin increases, the mold release effect increases, but the reactivity of the phenol novolak decreases. Moreover, the higher the ratio of the mold-releasing resin used, the better the mold-releasing property of the epoxy resin composition becomes. Furthermore, the molecular weight of the mold release resin changes as compression molding → transfer molding → injection molding.
It is desirable to lower the molecular weight as the process changes from high-pressure molding to low-pressure molding. The characteristics can be maximized by selecting the mixing ratio of the silicone compound/phenol novolak and the molecular weight used in the epoxy resin composition depending on the purpose. Especially for epoxy resin low-pressure encapsulation molding materials, the silicone compound/phenol novolak ratio is Si/OH.
It is preferable that the base molar ratio is 1 to 10 to 10/10, the usage ratio in the molding material is 0.5 to 5% by weight, and the molecular weight of the phenol novolak is 250 to 600. In a range other than the above, disadvantages such as poor moldability may occur. Further, by using the mold release resin according to the present invention, features such as lower internal stress of molded products and improved moisture resistance can be obtained. This is due to the structure and water repellency of silicone. Examples will be explained below. Moreover, the raw materials of the mold release resin used in the examples are as follows. Phenol novolac A: Number average molecular weight 450 (OH
Equivalent weight 102) Phenol novolak B: Number average molecular weight 200 (OH
Equivalent weight 100) Phenol novolak C: Number average molecular weight 700 (OH
Equivalent weight 104) Silicone gamma glycidoxypropyl group-containing organopolysilohexane (molecular weight 8798,
Si content 32.1% by weight, epoxy equivalent 880) Silicone gamma glycidoxypropyl group-containing organopolysilohexane (molecular weight 15088,
Si content 37.3% by weight, epoxy equivalent 7544) Silicone β-(3,4-epoxycyclohexyl)ethyl group-containing organopolysiloxane (molecular weight 4442, Si content 32.1% by weight, epoxy equivalent 2221) Catalyst α: triphenylphosphine Catalyst β: Aluminum acetylacetonate Catalyst γ: 2, 3, 4, 6, 7, 8, 9, 10, -
Octahydropyramide (1, 2-a) Azepine Basic manufacturing method Octocresol novolak type epoxy resin 20
part, phenol novolac part a, mold release resin b
1 part, 70 parts of crystalline silica, 0.2 parts of silica modifier, and d part of carnauba wax, and heated with a heated roll at 90℃ for 5 minutes.
Knead for a minute. (Note) The number average molecular weight of the phenol novolak used in the basic manufacturing method is 600. Applicability: By combining phenol novolak A, B, and C with silicone and catalysts α, β, and γ and heating and melting and mixing them, several types of mold release can be achieved. We made a prototype of resin. This resin was converted into a material using a basic manufacturing method to obtain various epoxy resin molding materials. These materials were molded using a transfer molding machine and their mold release properties and mold staining properties were evaluated. In addition, the stampability was evaluated using the molded product. The results are shown in the attached table, and the phenol novolac/silicone heat-melted mixture of the present invention using the mold release resin not only has excellent mold release properties and mold staining, but also has excellent stamping properties. 【table】

Claims (1)

[Claims] 1 Si/OH group molar ratio is 1/10 to 10/10,
A random copolymer obtained by heating and melting a phenol novolak having a molecular weight of 250 to 600 and an organopolysilohexane having at least one epoxy group is added in an amount of 0.5 to 5% by weight based on the entire composition. An epoxy resin composition consisting of.