JPS6236050B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an epoxy resin composition that has excellent mold releasability and imprintability and is free from mold stains, and its feature is that the silicone compound is uniformly dispersed in the resin component or fixed by reacting with the resin component. . 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 process of molding thermosetting resins, is good mold release properties 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 causes mold fogging and mold staining by being baked into the mold due to thermal history, that is, releasing. A good mold and less mold contamination are mutually exclusive.
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, so a molding material with good marking properties is desired. This imprinting property is also a characteristic that is a prerequisite to the 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 (1) an epoxy resin composition prepared by adding a heated and melted mixture of a phenol novolac and a silicone compound to an epoxy resin. (2) Phenol novolacs and silicone compounds are heated and melted in the presence of one or more selected from tertiary amines and derivatives thereof, organic phofin compounds, organic aluminum compounds, titanium compounds, or acids. This is an epoxy resin composition obtained by adding the mixture to an epoxy resin. 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, silicone compounds refer to organosilanes and organopolysiloxanes in general, such as (i) general formula (R ¹ )mSi(OR ² )n R ¹ : alkyl group, vinylated alkyl group, or epoxidized alkyl group (e.g. ,−
CH ₃ , −C ₂ H ₅ ,

【formula】

[Formula], etc.) R ² :-H, alkyl group (-CH ₃ , -C ₂ H ₅ , etc.) However, m+m=4 (m, n≧1) Organosilane (ii) in one molecule Refers to organopolysiloxane compounds that have at least one ^OR2 group or epoxy group. Furthermore, examples of reaction catalysts include tertiary amines and their derivatives, trimethylamine, triethylamine,
2, 3, 4, 6, 7, 8, 9, 10 - octahydro-pyramid (1,2-a) azepine, etc. and quaternary ammonium salts thereof Organic phosphine compounds (a) First, second, second 3 Phosphines: Octylphosphine, Butylphenylphosphine,
Tricyclohexylphosphine, triphenylphosphine, etc. (b) Petaine-type adducts of organic tertiary phosphine and compounds having a π bond: maleic anhydride-triphenylphosphine adduct, thioisocyanate-triphenylphosphine adduct, Diazodiphenylmethane-triphenylphosphine adduct, etc. (c) Organic phosphonium salt [ ₃ PCH ₂ )Cl, [ ₃ PEt] I,
[ ₃ PEt] Bretc Organoaluminum compound (a) Al (OR) ₃ R: H, alkyl group, aryl group, aryl group-containing hydrocarbon group, aluminum isopropoxide, aluminum n
-ptoxide, aluminum tert-poxide, aluminum pec-butylate, aluminum benzoate, etc. (b) Aluminum β-diketone complex (aluminum chelate) Aluminum acetylacetonate, aluminum trifluoroacetylacetonate, aluminum pentafluoroacetylacetonate, etc. Titanium compounds Butyl Examples include titanate, titanium white, etc., acids, para-toluenesulfonic acid, etc. The present invention is a material obtained by heating and melting mixing a phenol novolac and a silicone compound in the absence or presence of a catalyst (hereinafter referred to as a mold release resin), that is, a silicone compound with excellent mold release properties. Ingredients (phenol novolacs)
A releasable resin is obtained by uniformly dispersing it in a mold or reacting it with a resin component, and an epoxy resin composition using this releasable resin has excellent mold releasability, imprintability, and mold stain resistance. This is what I discovered. By uniformly dispersing or fixing a silicone compound with excellent mold release properties in 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, it has become possible to create an epoxy resin composition that has excellent mold releasability, imprintability, and mold stain resistance. The present invention uses an 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, the molecular weight, the usage ratio in the epoxy resin composition, etc. depending on the purpose. Especially for epoxy resin low-pressure encapsulation molding materials, the silicone compound/phenol novolak ratio is Si/OH.
It is desirable that the base molar ratio is 1/10 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 Phenol novolac B: 〃 200 Phenol novolac C: 〃 700 Silicone: Methyltriethoxysilane Silicone: Silicone varnish intermediate (OCH ₃
Type) Silicone: Silicone resin (OH type) Catalyst α: Triphenylphosphine catalyst β: Aluminum acetylacetonato catalyst γ: 2, 3, 4, 6, 7, 8, 9, 10, -octahydropyramide (1, 2-a) Basic manufacturing method of acepine Orthocresol 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 novolac used in the basic manufacturing method is 600. Application example: By combining phenol novolac A, B, and C with silicone and catalysts α, β, and γ, and heating and melting and mixing, several types of mold release can be achieved. We prototyped a synthetic 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】

[Table] ●Mold releasability: Molded with a releasability evaluation mold (mold without knock pins) and judged by the number of molds removed. ●Mold contamination: Determined by the number of molding shots until mold fogging or mold release failure occurs. ● Stampability: After stamping the molded product, apply cellophane tape. Judgment is based on the number of molded products whose stamps are removed when the cellophane tape is removed. ●Crack resistance: A molded product with a large insert inserted is subjected to a temperature cycle test (high and low temperatures), and judged by the number of cycles until a crack occurs in the molded product. ●Moisture resistance: Judging by the time it takes for a molded product with a moisture-sensitive element inserted into a pressurized humidifier to sense humidity.

Claims (1)

[Claims] 1. The Si/OH group molar ratio is 1/10 to 10/10,
An epoxy resin composition comprising 0.5 to 5% by weight of a heated and melted mixture of a phenol novolac and a silicone compound having a molecular weight of 250 to 600, based on the total composition. 2 Si/OH group molar ratio is 1/10 to 10/10,
Phenol novolacs having a molecular weight of 250 to 600 and a silicone compound in the presence of one or more selected from tertiary amines or derivatives thereof, organic phosphine compounds, organic aluminum compounds, titanium compounds, or acids. An epoxy resin composition comprising 0.5 to 5% by weight of the mixture heated and melted in the total composition.