JPH0420927B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a composition in which an alicyclic epoxy resin is blended with an inorganic filler. The present invention relates to an alicyclic epoxy resin formulation characterized in that by adding an alkali metal compound, the phenomenon of thickening during formulation is suppressed and the storage stability of the formulation is improved.

[Prior art]

Thermosetting compositions of alicyclic epoxy resins have excellent thermal stability and weather resistance, as well as electrical properties such as dielectric properties, volume resistivity, and dielectric breakdown strength, as well as bending strength, compressive strength, impact strength, etc. Because of its excellent mechanical properties, it is widely used as an insulating material for various electrical and electronic components by methods such as potting, casting, dip coating, and dripping.

Further, the reason why the alicyclic epoxy resin is used in the above method is that the alicyclic epoxy resin is characterized by its low viscosity at room temperature.

[Problem that the invention seeks to solve]

However, alicyclic epoxy resins have higher cationic polymerizability than other epoxy resins, such as Epibis type epoxy resins and cresol novolak type epoxy resins, so they undergo cationic polymerization when heated and mixed with inorganic fillers. progresses partially,
The viscosity increases with heating and mixing time, and may even solidify.

This phenomenon seems to occur frequently when fused silica powder is used as the inorganic filler. It is thought that the slight amount of →Si-OH remaining in the fused silica powder acts as a catalyst for ring-opening of the epoxy group, so that cationic polymerization progresses during heating and mixing, and the mixture thickens over time.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of extensive studies to suppress and prevent the phenomenon of thickening over time when blending such an alicyclic epoxy resin and an inorganic filler by heating and mixing. That is, the present invention comprises (A) 100 parts by weight of an alicyclic epoxy resin, (B) 100 to 500 parts by weight of an inorganic filler, and (C) at least one alkali metal selected from phosphoric acid, sulfonic acid, or an organic acid other than sulfonic acid. An alicyclic epoxy resin compound characterized by comprising 5 to 100 ppm of a compound (calculated as alkali metal atoms based on the alicyclic epoxy resin), which can significantly increase the amount of the compound when heated and mixed according to the above formulation. It has the effect of suppressing viscous phenomena.

Here, the alicyclic epoxy resin as component (A) in the present invention refers to a cyclohexene-based epoxy resin obtained by epoxidizing a cyclohexene derivative obtained by the Diels-Alder reaction of butadiene with peracetic acid or the like. , 4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-
Cyclopentadiene-based compounds obtained by epoxidizing epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 1-epoxyethyl-3,4-epoxycyclohexane, and derivatives of cyclopentadiene and dicyclopentadiene with peracetic acid, etc. These include dicyclopentadiene oxide, 2,3-epoxy-cyclopentyl ether, limonene dioxide, dipentene dioxide, and the like.

Further, in the present invention, it is also possible to appropriately add a bisphenol type epoxy resin as necessary.

Here, a typical bisphenol type epoxy resin is one obtained by reacting epichlorohydrin with bisphenol A or bisphenol F.
Glycidyl type epoxy resin having more than 3 epoxy groups, dimethyl glycidyl ether type epoxy resin obtained by reaction of methyl epichlorohydrin and bisphenol A or bisphenol F, or alkylene oxide adduct of bisphenol A and epichlorohydrin or methyl These include epoxy resins obtained from epichlorohydrin.

Inorganic fillers as component (B) include, for example, silica, alumina, metal oxides such as iron oxide, zinc oxide, and magnesium oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and iron hydroxide; iron powder; Metal powder such as alumina powder; other examples include asbestos powder, glass powder, calcium carbonate, magnesium carbonate, sodium sulfate, diatomaceous earth, and the like.
(Chopped strands and glass fiber mats with a fiber length of 3 to 25 mm are excluded.) The particle size is 0.1 to 100 μ. Preferably particle size is 30μ
The following are good. Moreover, among these, silica, ie, fused silica, is preferable.

The alkali metal compounds of component (C) include ascorbic acid, aspartic acid, adenosine-5'-phosphate, glycerophosphoric acid, succinic acid, allylsulfonic acid, alginic acid, guanosine-5'-phosphate, benzoic acid, and uridine-5'-phosphoric acid. 5'-phosphoric acid, trictansulfonic acid, oleic acid, carbamyl phosphoric acid, citric acid, glycolic acid, gluconic acid, glutamic acid,
Creatinine phosphate, acetic acid, salicylic acid, cyclohexane sulfamic acid, cyclohexyl sulfamic acid, di-P-tolyl phosphoric acid, dihydroxytartaric acid, dihydroxypropyl phosphoric acid, tartaric acid,
Oxalic acid, stearic acid, sorbic acid, thymolphthalein-phosphoric acid, thymidine-5'-phosphoric acid, tripolyphosphoric acid, phosphoric acid, phosphotungstic acid, phosphomolybdic acid, riboflavin-5'-phosphoric acid, lauric acid , monochloroacetic acid, metaphosphoric acid, maleic acid, mercaptoacetic acid, hexametaphosphoric acid, pyrophosphoric acid, pyruvic acid, butyric acid, hydroxybutyric acid, naphthol phosphate, phenyl phosphoric acid, phenolsulfonic acid, diphosphoric acid, naphthylacetic acid, naphthyl It is a sodium, potassium or lithium salt of phosphoric acid such as phosphoric acid, sulfonic acid or an organic acid other than sulfonic acid. Among these, sodium, potassium or lithium salts containing phosphorus are preferred.

Particularly preferred are alkali metal salts of tripolyphosphoric acid, in which at least one of sodium, potassium, and lithium is present as the alkali metal, and higher alcohols having 5 to 10 carbon atoms, such as octyl The most preferred is one in which one or more alcohols are bonded.

The amount of component (C), phosphoric acid, sulfonic acid, or an alkali metal compound of an organic acid other than sulfonic acid, is 5 to 100 ppm in terms of alkali metal atoms based on the alicyclic epoxy resin.

It is possible to add 100 ppm or more of an alkali metal compound of phosphoric acid, sulfonic acid, or an organic acid other than sulfonic acid to the alicyclic epoxy resin in terms of alkali metal atoms. This is not preferable because the thickening phenomenon occurs again during blending and kneading. Furthermore, when used in the field of resin sealing materials, the influence of impurities becomes apparent, which is undesirable.

Moreover, when the content is 5 ppm or less, no effect of sufficiently suppressing the thickening phenomenon is observed.

The mixing and kneading temperature of these materials is preferably within the range of room temperature to 100°C.

The alicyclic epoxy resin composition thus obtained can be further blended with a curing agent to form a thermosetting epoxy resin composition. The appropriate amount of the acid anhydride used as a curing agent for these epoxy resins is 0.5 to 1.2 equivalents, preferably 0.7 to 1.0 equivalents, based on the epoxy resin.

Such acid anhydrides include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, succinic anhydride,
Examples include itaconic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, clodicic anhydride, and the like. These can be used alone or in combination of two or more.

Further, if only blending these acid anhydrides with the epoxy resin would require a long time for curing and molding, an accelerator may be used as necessary.

Such accelerators include diethylamine, triethylamine, benzyldimethylamine, triethanolamine, pyridine, piperidine, 1.8-
Examples include diazabicycloethylamine, _BF3 -n-hexylamine, 2-methyl-imidazole, 2-ethyl-4-methylimidazole, tin octylate, and the like.

Furthermore, it is also possible to add flame retardants such as Sb ₂ O ₃ , bromine compounds, cresyl phosphate and the like to such formulations, if necessary.

〔Effect of the invention〕

In this way, 5 to 100 pm of an alkali metal compound of phosphoric acid, sulfonic acid, or an organic acid other than sulfonic acid is added to the alicyclic epoxy resin in terms of alkali metal atoms. The mixture of inorganic filler and inorganic filler showed no phenomenon of thickening over time during compounding and kneading, and
It also has good storage stability.

Next, the present invention will be specifically explained using examples.

Example 1 As an alicyclic epoxy resin, fused silica (Tatsumori Kogyo's "Fuse Rex RD-
8) was added, 5 ppm of Na compound of phosphoric acid ester (tripolyphosphoric acid ester bound with octyl alcohol) was added to the alicyclic epoxy resin in terms of Na, and the mixture was heated at 80°C for 3 hours. Kneaded. The kneading time and viscosity were as shown below.

Kneading time After 1Hr After 2Hr After 3Hr Viscosity (CPSat80℃) 2800 6100 10000 Compared to Comparative Example 1, with this degree of viscosity change,
There are almost no problems in use.

Example 2 The same alicyclic epoxy and inorganic filler as in Example 1 were used, the same formulation was used, 10 ppm of Na compound of phosphate ester was added, and the mixture was heated at 80°C.
The mixture was heated and mixed for 3 hours.

Kneading time After 1Hr After 2Hr After 3Hr Viscosity (CPS at 80℃) 2000 2000 2000 This product was left at 40℃ for 1 month and then the viscosity at 80℃ was measured, and it was found to be 2100cps, which showed almost no change. .

Example 3 The same alicyclic epoxy and inorganic filler as in Example 1 were used, the same formulation was used, 100 ppm of Na compound of phosphate ester was added, and the mixture was heated at 80°C.
The mixture was heated and mixed for 3 hours.

Kneading time After 1Hr After 2Hr Viscosity after 3Hr (CPSat80℃) 1200 2000 2300 Comparative example 1 The same alicyclic epoxy and inorganic filler as in Example 1 were used, the same formulation was used, and the Na compound of the phosphate ester was replaced with Na. Add 1ppm in terms of conversion and heat at 80℃
The mixture was heated and mixed for 3 hours.

Kneading time After 1 hour After 2 hours After 3 hours Viscosity (CPS at 80°C) 22000 78000 600000 A severe thickening phenomenon was observed. This was difficult to later combine with curing agents.

Comparative Example 2 As an alicyclic epoxy resin, based on 100 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,
Silica (Tatsumori Kogyo Co., Ltd. “Heezrex RD-8”)
By adding 240 parts by weight of phosphoric acid ester, the Na compound of the phosphoric acid ester was converted to 200 ppm based on the alicyclic epoxy resin.
and kneaded at 80°C for 3 hours. The kneading time and viscosity were as shown below.

Kneading time After 1Hr After 2Hr After 3Hr Viscosity (CPSat80℃) 1600 2100 2200 Almost no increase in viscosity was observed during kneading, but the pot life was short when blended with acid anhydride (hexahydrophthalic anhydride), making it difficult to use. was difficult.

Example 4 Alicyclic epoxy resin and inorganic filler Example 1
The same product was used, the same formulation was used, 50 ppm of sodium stearic acid was added, and 3
The mixture was heated and mixed for an hour.

Kneading time After 1 hour After 2 hours After 3 hours Viscosity 2300 3300 5700 (cps at 80℃) After this product was left at 40℃ for one month, the viscosity at 80℃ was measured, and it was 2500cps, showing almost no change. It was acknowledged that there was no.

Example 5 Alicyclic epoxy resin and inorganic filler in Example 1
The same compound is used, the same formulation is used, and the potassium compound of phosphate ester is converted into potassium.
100 ppm was added and mixed while heating at 80°C for 3 hours.

Kneading time After 1 hour After 2 hours After 3 hours Viscosity 1300 2100 2400 (cps at 80℃) Example 6 Alicyclic epoxy resin and inorganic filler were mixed in Example 1
The same product was used, the same formulation was used, and 50 ppm of Na salt of octane sulfonic acid was added in terms of Na.
The mixture was heated and mixed at ℃ for 3 hours.

Kneading time After 1 hour After 2 hours After 3 hours Viscosity 2400 3500 6300 (cps at 80°C).

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of alicyclic epoxy resin (B) 100 to 500 parts by weight of inorganic filler (C) At least one type of organic acid selected from phosphoric acid, sulfonic acid, or an organic acid other than sulfonic acid An epoxy resin formulation comprising 5 to 100 ppm of an alkali metal compound (calculated as alkali metal atoms based on the epoxy resin).