JPH04337314A - New epoxy resin, resin composition and cured material thereof - Google Patents

Abstract

PURPOSE:To obtain the title new resin suitable for sealing electronic parts, having low reduction in melt viscosity, excellent workability, providing a cured material with a low content of hydrolyzing chlorine, high heat resistance and low water absorption properties by epoxidizing a naphthol polymer containing no methylene chain. CONSTITUTION:A naphthol resin (e.g. 1-naphthol polymer) shown by formula I (R is H, 1-4C alkyl, aryl or halogen; n is 0-10) having excellent thermal stability is reacted with an epihalohydrin compound (e.g. epichlorohydrin) shown by formula II (X is halogen) in a nitrogen atmosphere in the presence of a basic compound (e.g. sodium hydroxide) at 60 deg.C, formed water and water in an aqueous solution of sodium hydroxide are continuously removed out of the reaction system by azeotropy and the reaction product is extracted with a solvent such as methyl isobutyl ketone to give a new epoxy resin based on a naphthol shown by formula III free from methylene chain.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to epoxy resins, resin compositions, and cured products thereof useful as materials for sealing or laminating electronic components.

0002

BACKGROUND OF THE INVENTION Conventionally, resin compositions containing epoxy resins, phenol novolac resins, and curing accelerators as main components have been widely used in the field of sealants for electrical and electronic components, particularly ICs. Among these, cresol novolac type epoxy resins are widely and generally used, especially as materials for electrical and electronic parts such as sealants, because of their well-balanced properties such as heat resistance of the cured products.

0003

[Problems to be Solved by the Invention] However, conventional novolak-type epoxy resins have problems with the high density of recent ICs.
It is no longer possible to cope with the increase in the amount of filler due to higher integration in terms of melt viscosity and the like. Therefore, it is desired to develop a high-purity epoxy resin that provides a cured product with well-balanced physical properties while maintaining heat resistance, has a low melt viscosity, and is excellent in workability.

0004

[Means for Solving the Problems] As a result of intensive studies aimed at solving the above problems, the present inventors have developed naphthols with good thermal stability that do not have methylene chains directly bonded between the carbons of the naphthalene nucleus. The present invention was completed based on the discovery that an epoxy resin with good thermal stability that can achieve the above objectives can be obtained by epoxidizing a polymer.

That is, the present invention provides formula (1) [1]

000
6]

[Case 2]

(In the formula, R is a hydrogen atom, a carbon number of 1 to 4
represents an alkyl group, aryl group or halogen atom, and n
takes a value of 0 to 10, preferably a value of 0 to 4. ) Epoxy resin represented by

(2) An epoxy resin composition containing an epoxy resin represented by formula [1] of (1) above, a curing agent, and a curing accelerator;

(3) A cured product of the epoxy resin composition of (2) above.

The present invention will be explained in detail below. The epoxy resin of the present invention can be manufactured as follows. That is, formula [2]

[0011]

[C3]

(In the formula, R is a hydrogen atom, a carbon number of 1 to 4
represents an alkyl group, aryl group or halogen atom, and n
takes a value from 0 to 10. ) and a naphthol resin with good thermal stability represented by the formula [3]

[0014]

[C4]

The epoxy resin represented by the formula [1] can be easily obtained by reacting the epihalohydrin compound represented by the formula (wherein, X represents a halogen atom) in the presence of a basic compound. Specifically, the resin represented by the formula [2] includes 1-naphthol polymer, 2-naphthol polymer, 2-methyl-1-naphthol polymer, 4-bromo-1-naphthol polymer, and 2-bromo-1-naphthol polymer.
Examples include 1-naphthol polymer and 4-phenyl-1-naphthol polymer, and 1-naphthol polymer and 2-naphthol polymer are particularly preferred, but the polymer is not particularly limited thereto.

In the above formula [3], examples of the halogen atom represented by X include Cl, Br, I, etc.
Specifically, the compounds include epichlorohydrin,
Examples include epibromohydrin and epiiodohydrin, and mixtures thereof can also be used, but epichlorohydrin is preferably used industrially. The reaction between the resin represented by formula [2] and the epihalohydrin compound can be carried out by a known method.

For example, a thermally stable resin represented by formula [2] and an epihalohydrin compound in an excess molar amount relative to its hydroxyl equivalent are mixed with tetramethylammonium chloride, tetramethylammonium bromide, triethylammonium chloride, etc. The reaction is carried out in the presence of a quaternary ammonium salt or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. If a quaternary ammonium salt is used, the reaction will stop at the stage of the ring-opening addition reaction. Next, the above-mentioned alkali metal hydroxide is added to carry out a ring-closing reaction.

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 usage ratio of the epihalohydrin compound is usually 1 to 1 equivalent of hydroxyl group of the resin represented by formula [2].
50 moles, preferably in the range of 3 to 15 moles. In addition, at this time, in order to carry out the reaction smoothly, alcohols such as methanol, or acetone, or aprotic polar solvents such as dimethyl sulfoxide, dimethyl sulfone, and dimethyl formamide can be used, and dimethyl sulfoxide is particularly preferred. is preferable.

The amount of alkali metal hydroxide used is determined by the formula [2
] Usually 0.8 to 1 per hydroxyl equivalent of the resin
1.5 mol, preferably in the range of 0.9 to 1.3 mol, and when using a quaternary ammonium salt, the amount used is based on 1 hydroxyl equivalent of the resin represented by formula [2]. Usually 0.001 to 1.0 mol, preferably 0.005 to 0.0 mol.
It is in the range of 5 moles. The reaction temperature is usually 30-150℃,
Preferably it is 50-120°C. Furthermore, the reaction can be allowed to proceed while removing water produced in the reaction from the reaction system. After the reaction is completed, the by-produced salt is removed by washing with water, filtration, etc. to obtain a thermally stable epoxy resin represented by the formula [1].

Various curing agents can be used in the epoxy resin composition of the present invention and are not particularly limited. For example, polyamine curing agents such as aliphatic polyamine, aromatic polyamine, and polyamide polyamine, acid anhydride curing agents such as hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride, and phenolic curing agents such as phenol novolac and cresol novolak. , the above formula [
2], Lewis acids such as boron trifluoride or their salts, dicyandiamide, and the like. The amount of curing agent is determined based on the amount of epoxy groups of the epoxy resin in the resin composition.
It is preferably 0.5 to 1.5 equivalents, particularly 0.5 to 1.5 equivalents.
6 to 1.2 equivalents are preferred.

Specific examples of the curing accelerator include imidazole compounds such as 2-methylimidazole and 2-ethylimidazole, tertiary amine compounds such as 2-(dimethylaminomethyl)phenol, and phosphine compounds such as triphenylphosphine. etc., and is not particularly limited. The curing accelerator is preferably blended in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin in the resin composition.

Furthermore, known additives may be added to the resin composition of the present invention, if necessary. Examples include inorganic fillers such as silica, alumina, talc, and glass fiber, surface treatment agents for fillers such as silane coupling agents, mold release agents, and pigments.

The resin composition of the present invention can be obtained by uniformly mixing each component. The resin composition of the present invention is usually precured at a temperature of 130 to 170°C, and further cured at a temperature of 150 to 170°C.
By post-curing at a temperature of 200° C. for 2 to 8 hours, a sufficient curing reaction proceeds and the cured product of the present invention is obtained. The cured product thus obtained has excellent physical properties such as high heat resistance and low water absorption.

Therefore, the epoxy resin and epoxy resin composition of the present invention can be used in a wide range of fields where high heat resistance, low water absorption, etc. are required. Specifically, it is useful as a compounding component of all electrical and electronic materials such as insulating materials, laminates, and sealing materials. Moreover, it can be used in fields such as molding materials and composite materials. Furthermore, since the epoxy resin and epoxy resin composition of the present invention have a low melt viscosity, conventional techniques such as transfer molding can be used, and workability is also good.

[0025]

[Examples] The present invention will be explained in more detail with reference to Examples below. Example 1. In a reactor equipped with a thermometer, a stirring device, a dropping funnel, and a water separation device, resin A (in the above formula [2], R is a hydrogen atom, the hydroxyl group is at the 2-position, and n = 0.5,
Average molecular weight 390, hydroxyl equivalent (g/eq) 180) 1
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 aqueous sodium hydroxide solution were continuously removed from the reaction system by azeotropy 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.

[0026] After recovering excess unreacted epichlorohydrin under reduced pressure, 100% of methyl isobutyl ketone was recovered.
ml was added and washed with water until the aqueous layer became neutral. Methyl isobutyl ketone was removed from the organic layer under reduced pressure, and then 400 g of methyl isobutyl ketone was added again and redissolved. To the obtained methyl isobutyl ketone solution, 20 g of a 20% aqueous sodium hydroxide solution was added and reacted at a reaction temperature of 70° C. for 2 hours.

After the reaction was completed, the aqueous layer was washed with water until it became neutral, and methyl isobutyl ketone was removed from the oil layer under reduced pressure to obtain 228 g of a pale yellow solid (AE-1). The product (AE
-1) has an ICI viscosity of 1.3 poise and a softening temperature of 74.
The epoxy equivalent (g/eq) was 250 at 2°C. Moreover, the amount of hydrolyzable chlorine was 216 ppm.

The product thus obtained (AE-1
) is an epoxy resin in which n=0.5, R=H, and the glycidyloxy group is bonded at the 2-position in formula [1].

Example 2. 180 g of the resin A, 460 g of epichlorohydrin, and 115 g of dimethyl sulfoxide were charged into a reactor equipped with a thermometer, a stirring device, and a dropping funnel, and the reactor was purged with nitrogen. Then, 40 g of sodium hydroxide was gradually added in a water bath at 30°C. 3 while being careful of fever
The reaction was carried out at 0°C for 5 hours, at 50°C for 2 hours, and further at 70°C for 1 hour. Then, water was added to wash the mixture until the aqueous layer became neutral. Thereafter, epichlorohydrin and dimethyl sulfoxide were removed from the oil layer under reduced pressure.

Next, 400 g of methyl isobutyl ketone was added and redissolved. 20 g of a 20% aqueous sodium hydroxide solution was added to the obtained methyl isobutyl ketone solution, and the mixture was reacted at a reaction temperature of 70° C. for 2 hours. After the reaction was completed, the aqueous layer was washed with water until it became neutral, and methyl isobutyl ketone was removed from the oil layer under reduced pressure to obtain 230 g of a pale yellow solid (AE-2). The product (AE-2), which is an epoxy resin represented by the formula [1] of the present invention, has an ICI viscosity of 1.8 poise, a softening temperature of 75.0°C, and an epoxy equivalent (g/eq) of 249.
Met. Moreover, the amount of hydrolyzable chlorine was 210 ppm.

The resin A used in the above examples is as follows. Resin A: 2-naphthol polymer manufactured by Harima Kasei Co., Ltd. Average molecular weight 390 Hydroxyl group equivalent 180 (g/eq) Softening temperature
104.0 (℃) ICI viscosity 4.8 poise Softening temperature: JIS K2425K ring and ball method ICI viscosity: Cone plate type; 150℃

[0032] Also,
The amount of hydrolyzable chlorine was measured by the following method. (Amount of hydrolyzable chlorine) Accurately weigh 0.5 g of the sample (epoxy resin) into a 100 ml flask with a stopper, dioxane 30
Dissolve in milliliter. After dissolution, 5 ml of 1N-KOH ethanol solution was added, and the mixture was boiled and refluxed for 30 minutes. Thereafter, this solution was completely transferred to a 200 ml beaker, 100 ml of an 80% acetone aqueous solution was added, and then 2 ml of concentrated nitric acid was added, stirred, and quantified by potentiometric titration.

Application Examples 1-2. Products (AE-1) to (AE-2) obtained in Examples 1 to 2 as epoxy resins
), a commercially available phenol novolak resin (PNH-1) as a curing agent, triphenylphosphine (TPP) as a curing accelerator, and a composition containing these in the proportions shown in Table 1 was prepared. Roll kneaded for 15 minutes at ~80°C. After cooling, it is crushed, made into tablets, and then molded using a transfer molding machine at 160°C.
The sample was precured for 2 hours at 180° C., and postcured for 8 hours at 180° C. to obtain a cured product (test piece). The glass transition temperature (Tg) and water absorption rate of this cured product were measured. Table 1 shows the evaluation results of the cured product.

Application Comparative Examples 1-2. Bisphenol type epoxy resin (
Epomic R-301) or cresol novolak type epoxy resin (EOCN-3300) was used as a curing agent for commercially available phenol novolac resin (PN(H-1)).
)) with triphenylphosphine (T
PP) was blended, and the cured products were evaluated in the same manner as in Application Examples 1 and 2. The evaluation results are shown in Table 1.

The conditions for measuring physical properties are shown below. Glass transition temperature (Tg): DMA Rheolograph-Solid L-1
(Toyo Seiki Co., Ltd.) Temperature increase rate 2℃/min

Frequency 10Hz
Water absorption rate: Test piece diameter 50

(Cured product) Thickness: 3 discs
Conditions 24 hours in water at 100℃
Weight gain after boiling

(weight%)

0
[036] The commercially available resins blended are as follows. PN (H-1): (manufactured by Nippon Kayaku Co., Ltd.) Phenol novolac resin
Hydroxyl group equivalent (g/e
q) 106
Softening temperature
85℃ Epomic R-301: (manufactured by Mitsui Petrochemical Epoxy Co., Ltd.)
Bisphenol A type epoxy resin
Epoxy equivalent (g/eq) 470
Softening temperature 6
8℃ EOCN-3300: (manufactured by Nippon Kayaku Co., Ltd.) Cresol novolac epoxy
resin
Epoxy equivalent (g/eq) 187
Softening temperature
42.0℃

[0037]
Table 1
Application example Application comparison example

1 2 1
2
Product (AE-1) 250
Epoxy resin product (AE-2)
249
epomic
235
EOCN-3300

187 Hardening agent P
N(H-1) 106 106
53 106 Curing accelerator
TPP 2.5 2.
5 2.4 1.9 Glass transition temperature (℃) 181 18
2 170 172 Water absorption rate
(%) 0.9
0.9 1.9 1.2

003
8]

Effects of the Invention The resin of the present invention is a high purity epoxy resin (with a small amount of hydrolyzable chlorine) that has low viscosity, excellent workability, and good thermal stability. Further, the cured product obtained using the resin composition of the present invention has a high glass transition temperature, which is an index of heat resistance, and has a low water absorption rate. Therefore, the resin and resin composition of the present invention can fully meet the recent demands for high reliability, high purity, high heat resistance, low water absorption, etc., and can be used in a wide range of fields and concretely by utilizing this performance. is extremely useful as a sealing material, molding material, or laminating material for electronic components.

Claims (3)

[Claims] Claim 1: Formula [1] [Formula 1] (wherein, R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group, or a halogen atom, and n represents 0 to 10
takes the value of ) Epoxy resin. 2. An epoxy resin composition comprising the epoxy resin of claim 1, a curing agent, and a curing accelerator. 3. A cured product of the epoxy resin composition according to claim 2.