JPH044217A - Novolak epoxy resin of phenols and cured product thereof - Google Patents

Abstract

PURPOSE:To obtain a novolak epoxy resin of phenols, having a specific structural formula, curable to provide cured products excellent in heat resistance with low water absorptivity and suitable as insulating materials, etc. CONSTITUTION:A novolak epoxy resin of phenols is obtained by reacting a novolak resin of phenols, expressed by formula I (n is 0-30) and having <=20wt.% content of phenylphenolic novolak resin (n is 0) with an epihalogen compound expressed by formula II (X is halogen) in the presence of a basic compound (e.g. tetramethylammonium chloride). The aforementioned resin has a structural formula expressed by formula III (n is preferably 2-15) with <=20wt.%, preferably <=15wt.% content of the phenylphenolic novolak epoxy resin (n is 0).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a useful cured product from a phenolic novolac epoxy.

[Conventional technology]

In general, epoxy resins have excellent adhesive properties, chemical resistance, electrical properties, mechanical properties, and heat resistance, so they are widely used in adhesives, paints, electrical insulation materials, and various composite materials.However, in recent years, the conditions of use have gradually changed. As conditions become increasingly harsh, compositions with higher heat resistance and lower water absorption are desired.

In particular, with the recent development of electronic components, epoxy resins are often used as sealants for ICs, and among them, cresol novolac epoxy resins are used as epoxy resins that provide cured products with excellent heat resistance and water absorption. It is used.

[Problem to be solved by the invention]

However, even if the epoxy resin of cresol novolak is cured using phenol novolak as a curing agent, the heat resistance is still very satisfactory.
It is insufficient in terms of water absorption.

In other words, the problem of water absorption is caused by the phenomenon that in surface mounting of recent electrical circuits, under the harsh conditions of immersing the cured product in a non-contamination bath, the cured product breaks down due to the rapid expansion of the absorbed water. It will bring about.

Therefore, although heat resistance is also an issue, achieving low water absorption without impairing heat resistance is the biggest challenge for sealant manufacturers in recent years.

[Means to solve the problem]

In order to solve these problems, the inventors of the present invention have made extensive studies and have developed a haluphenol novolac epoxy resin obtained by converting phenylphenol into a novolac and epoxidizing a novolac resin with a reduced amount of low molecular weight compounds. The present inventors have discovered that the cured product can achieve low water absorption without impairing heat resistance, and have completed the present invention.

That is, the present invention provides general formula [I] (formula [I), in which the average value of n is 0 to 30. ), the content of phenylphenol novolac epoxy resin with n = 0 is 20i4i, and the average value of n of the phenylphenol novolac epoxy resin represented by -Funazo [I] above. is from 0 to 30, preferably from 2 to 20, more preferably from 2 to 15.

The phenolic novolac epoxy resin of the present invention has a cured product that is very advantageous in terms of water absorption, especially compared to a cured product obtained using a cresol novolac epoxy resin. give something.

n in the phenolic novolak epoxy resin of the present invention
= The component of Q is 20% by weight or less, but preferably 15% by weight.
% by weight or less.

The presence of low molecular weight substances in an amount exceeding 20% by weight results in a decrease in heat resistance.

(In the formula [■], the average value of n is 0 to 30.) In the phenylphenol novolak resin, n
= Phenylphenol novolak resin with a content of 20% or less of the phenylphenol novolak resin of Q, - Funagura I (wherein X represents a halogen atom), a shrimp halogen compound represented by the presence of a basic compound It can be easily obtained by the reaction described below.

Examples of the phenylphenol component in the general formula [■] include orthophenylphenol, paraphenylphenol, and metaphenylphenol, but orthophenylphenol is preferably used for the purpose of reducing the low molecular weight of the present invention.

Specific examples of the chemical compound include epichlorohydrin, epichlorohydrin, and ebiodohydrin, and mixtures of these can also be used, but epichlorohydrin is preferably used industrially.

The reaction between the phenolic novolac and the shrimp halogen compound represented by the general formula [Dish] can be carried out by a known method.

That is, a phenolic novolac and a shrimp halogen compound in an excess molar amount relative to the hydroxyl equivalent of the phenolic novolac are combined with a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, triethylammonium chloride, or sodium hydroxide. The reaction is carried out in the presence of an alkali metal hydroxide such as potassium hydroxide, or if a quaternary ammonium salt is used, the reaction stops at the ring-closing addition reaction stage, so the alkali metal hydroxide is then added. Perform a ring-closing reaction.

In addition, when the alkali metal hydroxide is added from the beginning and the reaction is carried out, the ring-opening addition reaction and the ring-closing reaction are carried out at once.

The proportion of the shrimp halogen compound to be used is preferably in the range of 1 to 50 mol, more preferably 3 to 15 mol, per liter of hydroxyl group equivalent of the phenolic novolak.

The amount of the alkali metal hydroxide used is preferably in the range of 08 to 1.5 mol, more preferably 09 to 1.3 mol, per 1 of the hydroxyl equivalent of the phenolic novolak, and a quaternary ammonium salt is used. In this case, the amount used is preferably 0 per 1 hydroxyl equivalent of the phenolic novolac.
．． The range is 0.001-1 mol, more preferably 0.005-0.05 mol.

The reaction temperature is preferably 30 to 130°C, more preferably 40 to 120°C.

Furthermore, the reaction can be allowed to proceed while removing water produced in the reaction from the reaction system.

After the completion of the reaction, the salt produced as a by-product is removed by washing with water, filtration, etc., and the excess shrimp halogen compound is distilled off to obtain an epoxy resin.

The phenolic novolak used in the above reaction can be produced as follows.

Namely, phenylphenols and formaldehyde are dehydrated and condensed by a known method in the presence of an acid catalyst, and further,
In order to remove low-molecular weight substances, the phenylphenol novolak resin represented by -Funakura [■] is extracted with 20% or less of phenylphenol resin, where n=0, by extraction with hot water or the like. Resin is obtained.

The epoxy resin of the present invention can be used alone or in combination with other epoxy compounds, for example, phenolic novolac type epoxy resins such as bisphenol type epoxy resins and cresol novolanoqueous resins, to produce aliphatic polyamines as well as ordinary epoxy resins. , polyamine curing agents such as aromatic polyamines and polyamide polyamines, acid anhydride curing agents such as hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride, phenolic curing agents such as phenol novolak and cresol novolak, trifluoride, etc. It can be hardened using a Lewis acid such as boron or a salt thereof, a hardening agent such as dicyandiamide, or the like. The amount of curing agent used at this time is preferably 0.5 to 1.5 equivalents, more preferably 0.8 to 1.2 equivalents per equivalent of epoxy group. be.

Further, if necessary, a curing accelerator such as imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, triphenylphosphine and salts thereof, etc. is preferably added in an amount of 05 to 3% by weight based on the epoxy resin. Furthermore, various compounding agents such as inorganic or organic fillers can be added.

The composition thus formulated is usually precured at a temperature of 150 to 180°C for a period of 30 to 3 Q Q sec,
Furthermore, sufficient curing reaction proceeds by post-curing at a temperature of 150-180° C. for 2-8 hours. The cured product thus obtained has low water absorption while maintaining heat resistance.

The epoxy resin of the present invention can be used in a wide range of fields where heat resistance and low water absorption are required, including insulating materials, laminate sealing materials,
It can be used in fields such as molding materials and composite materials.

〔Example〕 The present invention will be explained below with reference to Examples.

Synthesis Example 1゜In a glass container equipped with a thermometer and a stirrer, 70 g (1 mol) of orthophenylphenol and 2 paraformaldehyde were added.
4 g (0.8 mol) and 15 Qml of hydrene were charged and stirred at a bath temperature of 80° C. under a nitrogen atmosphere.

p-) #1 g of ensulfonic acid was gradually added while being careful not to generate heat.

After the addition, the reaction was continued for 10 hours while keeping the bath temperature at 80°C, and then the reaction was completed.

Thereafter, 300 rnl of toluene was added, and the mixture was washed with water to return to neutrality.

The organic layer was concentrated under reduced pressure to obtain 175 g of product. Further, the obtained product was washed five times with 500 cc of hot water. During this washing, the product was stirred to disperse it as much as possible, and the hot water was removed using decanethisilane.

The softening temperature (J
IS K2425 ring and ball method) is the hydroxyl equivalent (g
/mol) was 180.

Synthesis Example 2 A product (Bl) was obtained in the same manner as in Synthesis Example 1 except that the amount of paraformaldehyde (17) was changed to 18 g (0.6 mol).

The softening temperature of the product (B1) is 93°C and the hydroxyl equivalent is 17
It was 8.

Synthesis Example 3 A product (CI) was obtained in the same manner as in Synthesis Example 1 except that paraphenylphenol was used instead of ortho phenylphenol.

The softening temperature of the product (C1) is 103°C and the hydroxyl equivalent is 1
It was 78.

Comparative Synthesis Example In Synthesis Example 1, the product (DI) was obtained without performing the extraction operation with hot water.

The softening temperature of the product (Dl) is 90'C and the hydroxyl equivalent is 1
It was 78.

Products obtained in Synthesis Examples 1 to 3 and Comparative Synthesis Examples (AI)
, (B1), (C1), and (DI), the content of the component where n = Q in the phenylphenol novolac resin represented by -Fleet CI [] was as follows.

n=Q component product content 1% by weight) ”0 average 1 (AI)
13 4.2 (Bl)
18 3.5 (C1)
18 3.7 (DI)
25 3.1 The analysis conditions are as follows.

GPC device: Takasugi Seisakusho (Column: TSK-G-3000XL (1 piece) + TS
K-G-2000XL (2 bottles) Solvent: Tetrahydrofuran 1ml/min Detection:
UVC 254 nm) Example 1 The product (AI) 1 obtained in Synthesis Example 1 was placed in 11 reactors equipped with a thermometer, a stirring device, a dropping funnel, and a product water separation device.
After charging 80 g and 460 g of epichlorohydrin and purging with nitrogen, 85 g of a 48% aqueous sodium hydroxide solution was added dropwise over 5 hours. During the dropwise addition, the produced water and the water in the sodium hydroxide aqueous solution were continuously removed from the reaction system by azeotroping with epichlorohydrin under conditions of a reaction temperature of 60°C and a pressure of 100 to 150 mmHg, and epichlorohydrin was returned to the system. .

Then, after recovering excess unreacted epichlorohydrin under reduced pressure, 500 m/addition of methyl isobutyl ketone was added.
It was washed with 0 m/ml of water until the aqueous phase became neutral.

The methylinobutylketone phase was concentrated under reduced pressure to obtain 220 g of pale yellow solid (A).

The formation dynamics were a softening temperature (JIS K2425) of 72°C and an epoxy equivalent (g/mol) of 260. In addition, when the generation motive force was analyzed by GPC in the same manner as in the synthesis example, n = O
The composition amount of the low molecular weight substance was 13% by weight.

Example 2゜Product (Bl) obtained in Synthesis Example 2 instead of product (AI)
218 g of product Q3) was obtained in the same manner as in Example 1 except that 178 g was used. Product 03) has a softening temperature of 70°C, an epoxy equivalent of 261, and n according to GPC analysis.
= The composition amount of the low molecular weight substance of Q was 18% by weight.

Example 3 Product (CI) obtained in Synthesis Example 3 instead of product (AI)
215 g of product (C) was obtained in the same manner as in Example 1 except that 178 g was used. Product (C) had a softening temperature of 78° C., an epoxy equivalent of 270°, and a composition of low molecular weight substances with n=Q as determined by GPC analysis of 18% by weight.

Product CDI obtained in the comparative synthesis example instead of the comparative example product (Al))
The same procedure as in Example 1 was carried out except that 178 g was used to obtain 216 g of product (2). Product ■) has a softening temperature of 70℃
The epoxy equivalent is 260° as determined by GPC analysis: n = Q
The composition amount of the low molecular weight substance was 25% by weight.

Application Examples 1 to 3 Phenol novolac (manufactured by Nippon Kayaku ■, softening temperature 85°C, hydroxyl equivalent (g/
Products (A), (B), and (C1) mainly composed of the phenolic novolak epoxy compound obtained in Example 1.2.3 were blended with mol ) 105, and 2-methylimidazole was used as a catalyst. It was heated and cured.

Product (A) obtained in Example 1.2.3 as a comparative example
In place of (C), the product obtained in the comparative synthesis example) and the following commercially available 0-cresol novolac type epoxy resin were used at the blending ratios (parts by weight) shown in Table 1 to heat cure.

EOCN 1020: manufactured by Nippon Kayaku ■, epoxy equivalent (g/mol) 202, softening temperature 67°C The measurement sample was a composition with the blending amount shown in Table 1 at 70°C.
After roll kneading for 15 minutes at ~80°C, cooling, crushing and tableting, and further molding with a transfer molding machine,
Created by post-curing.

Post-cue conditions Temperature: 180°C Time 2 The glass transition temperature (Tg), heat distortion temperature (HDT), and water absorption rate of the cured product for 8 hours or more were measured, and the results are shown in Table 1.

The measurement conditions for glass transition temperature, heat distortion temperature, and water absorption are as follows.

Glass transition temperature thermomechanical measuring device (TMA); Vacuum Riko TM-7000 Heating rate: 2°C/min Heat deformation temperature JIS K7207 Water absorption Test piece Diameter 5Qmm Thickness 3mm Disc condition 50°C in water at 10.0°C Water absorption rate (weight %) according to weight increase after boiling for a time Has low water absorption.

Therefore, it has industrial value mainly as a material for electronic parts such as a sealant.

Claims (2)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula [I], the average value of n is 0 to 30.) In the phenylphenol novolak epoxy resin, A phenolic novolac epoxy resin characterized in that the content of the phenylphenol novolac epoxy resin in which n=0 is 20% by weight or less. (2) A cured product of the phenolic novolak epoxy resin according to claim 1.