JP2023000658A - Dihydroxy compound, epoxy resin, production method thereof, and epoxy resin composition and cured product that are based thereon - Google Patents

Abstract

To provide a dihydroxy compound and an epoxy resin thereof that are capable of forming a cured product meeting requirements for high heat resistance and high thermal conductance and also having excellent incombustibility and the like, and that are useful in applications such as lamination, molding, casting and bonding.SOLUTION: The invention provides: a dihydroxy compound represented by the general formula (1) in the figure, where n represents a number from 0 to 1; and an epoxy resin obtained by reacting the dihydroxy compound with epichlorohydrin.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an epoxy resin that provides a cured product having excellent heat resistance, moisture resistance, etc., as well as excellent thermal conductivity, a dihydroxy compound that is a precursor thereof, an epoxy resin composition using the same, and a cured product thereof. It is suitably used as an insulating material in the electrical and electronic field such as printed wiring boards and semiconductor encapsulation.

In recent years, the development of higher-performance base resins has been demanded, especially with advances in the field of advanced materials. For example, epoxy resins, which are used to protect elements such as power devices, are required to have improved thermal conductivity in addition to heat resistance in order to cope with a large amount of heat emitted by the elements.

However, none of the conventionally known epoxy resins has been known to fully satisfy these requirements. For example, Patent Documents 1 to 3 propose a liquid crystalline epoxy resin having a rigid mesogenic group and an epoxy resin composition using the same, but the heat resistance and high thermal conductivity were not sufficient. . Patent Documents 2 and 4 and Non-Patent Document 1 describe epoxy resins and compositions having an azomethine group based on a benzene skeleton, but still have problems with heat resistance and high thermal conductivity.

JP-A-11-323162 Japanese Patent Application Laid-Open No. 2004-331811 JP-A-9-118673 JP-A-8-73564

M. Ochi, H. Takashima, Polymer 42, 2379 (2001)

Therefore, the object of the present invention is to meet the recent demands for high thermal conductivity and high heat resistance, to obtain a cured product excellent in flame retardancy, etc., and to use it for lamination, molding, casting, adhesion, etc. The purpose of the present invention is to provide an epoxy resin useful for , a dihydroxy compound which is a precursor thereof, a method for producing the same, an epoxy resin composition using the same, and a cured product thereof.

（但し、ｎは０～１の数を示す。） That is, the present invention is a novel dihydroxy compound represented by the following general formula (1).

(However, n indicates a number from 0 to 1.)

（但し、ｎは０～１の数を示し、ｍは０～５０の数を示す。） The present invention also provides a novel epoxy resin represented by the following general formula (2).

(However, n indicates a number from 0 to 1, and m indicates a number from 0 to 50.)

Further, the present invention is a method for producing a novel epoxy resin represented by the above general formula (2), characterized by reacting a dihydroxy compound represented by the above general formula (1) with epichlorohydrin.

Furthermore, the present invention provides an epoxy resin composition obtained by blending the above epoxy resin as an essential component of the epoxy resin component, and a cured product obtained by curing this epoxy resin composition.

The cured product obtained by curing the epoxy resin composition containing the epoxy resin of the present invention satisfies the requirements of high thermal conductivity and high heat resistance, and has excellent performance such as flame retardancy. It can be suitably used for applications such as casting and adhesion.

1 shows an H-NMR spectrum of epoxy resin A obtained in Example 2. FIG. 4 shows an IR spectrum of epoxy resin A obtained in Example 2. FIG.

ここで、ｎは０から１の数を表すが、好ましくは、０または１であり、特に好ましくは０である。 The present invention will be described in detail below.
The dihydroxy compound of the present invention is represented by the above general formula (1).

Here, n represents a number from 0 to 1, preferably 0 or 1, particularly preferably 0.

The dihydroxy compound of the present invention preferably has a hydroxyl equivalent of 90 to 300 g/eq, more preferably 100 to 250 g/eq.
In the naphthalene ring and benzene ring, the positional relationship between the azomethine group (-CH=N-) and the hydroxyl group (OH) is not limited, but in the naphthalene ring, the azomethine group is preferably 2 , is in 6th place. In the benzene ring, the azomethine group is preferably present at p-position relative to the hydroxyl group. It is desirable that the structures at the 2,6-positions of the naphthalene ring and the p-positions of the benzene ring account for 50 mol % or more.

The dihydroxy compound of the present invention is not particularly limited, but preferably can be synthesized by reacting hydroxynaphthaldehydes with aminophenols or diaminobenzenes.
Hydroxynaphthaldehydes and aminophenols or diaminobenzenes are desirably used in approximately equimolar amounts of aldehyde groups and amino groups. 1.2 mol, and 1.8 to 2.2 mol of hydroxynaphthaldehyde per 1 mol of diaminobenzenes.

Here, the hydroxynaphthaldehydes include 1-hydroxy-2-naphthaldehyde, 4-hydroxy-1-naphthaldehyde, 5-hydroxy-1-naphthaldehyde, 5-hydroxy-2-naphthaldehyde, 8-hydroxy- Examples include 2-naphthaldehyde, 2-hydroxy-1-naphthaldehyde, 3-hydroxy-2-naphthaldehyde, 6-hydroxy-2-naphthaldehyde and 7-hydroxy-2-naphthaldehyde. Examples of aminophenols include 2-aminophenol, 3-aminophenol and 4-aminophenol, and examples of diaminobenzenes include 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4- Mention may be made of diaminobenzene. These hydroxynaphthaldehydes, aminophenols and diaminobenzenes may be used alone or in combination of two or more.

本発明のエポキシ樹脂は、上述した式（１）で表されるジヒドロキシ化合物の二つの水酸基がグリシジルエーテル基となっており、それらのグリシジル基がさらにジヒドロキシ化合物の水酸基と反応した重合物であってもよい。 The epoxy resin of the present invention is an epoxy resin having an azomethine group represented by the above formula (2) and a naphthalene structure.

The epoxy resin of the present invention is a polymer obtained by reacting two hydroxyl groups of the dihydroxy compound represented by the above formula (1) with glycidyl ether groups, and further reacting these glycidyl groups with the hydroxyl groups of the dihydroxy compound. good too.

Here, n is the same as in formula (1). Also, m is the number of repetitions and represents a number from 0 to 50. In the case of a mixture of a plurality of compounds with different repeating numbers, the average value of m (Σm/Σnumber of molecules) is in the range of 0-50. The preferred value of m or its average value varies depending on the application. For example, for applications of semiconductor encapsulating materials that require a high filler filling rate, low viscosity is desirable, and the value of m or its average value is 0 to 5, preferably 0.1 to 2.0. More preferably, those having m of 0 are contained in 50 wt% or more, and the average value of m is from 0.1 to 1.0. Ordinary epoxy resins are often obtained by a sequential reaction in which a compound with m=0 is formed, which is then polymerized to form a compound with m=1. Epoxy resins can be used advantageously. These low molecular weight epoxy resins are optionally crystallized and used as solids at ambient temperature. In addition, high-molecular-weight epoxy resins are preferably used for applications such as printed wiring boards.

The method for producing the epoxy resin of the present invention is not particularly limited, but it can be produced by reacting the dihydroxy compound represented by the above formula (1) with epichlorohydrin. This reaction can be carried out in the same manner as a normal epoxidation reaction.

For example, after dissolving the dihydroxy compound represented by the above general formula (1) in excess epichlorohydrin, in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, the temperature is 50 to 150° C., preferably A method of reacting at a temperature in the range of 60 to 120° C. for 1 to 10 hours can be mentioned. In this case, the alkali metal hydroxide is used in an amount of 0.8 to 2 mol, preferably 0.9 to 1.2 mol, per 1 mol of hydroxyl group in the dihydroxy compound. Also, epichlorohydrin is used in an excess amount relative to the hydroxyl groups in the dihydroxy compound, usually in the range of 1.5 to 15 mol, preferably 2 to 8 mol, per 1 mol of the hydroxyl group in the dihydroxy compound. Moreover, a quaternary ammonium salt or the like can be added during the reaction. Quaternary ammonium salts include, for example, tetramethylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride and the like, and the amount added is preferably in the range of 0.1 to 2.0 wt% with respect to the dihydroxy compound. . If the amount is less than this, the effect of adding the quaternary ammonium salt is small, and if it is more than this, the generation of hardly hydrolyzable chlorine increases, making it difficult to achieve high purity. Furthermore, polar solvents such as dimethylsulfoxide and diglyme may be used, and the amount added is preferably in the range of 10 to 200 wt% with respect to the dihydroxy compound. If the amount is less than this, the effect of addition is small, and if it is more than this, the volumetric efficiency is lowered, which is economically unfavorable. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene or methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and the solvent is distilled off to obtain the desired epoxy. resin can be obtained.

The epoxy resin composition of the present invention comprises an epoxy resin and a curing agent, and contains an epoxy resin represented by the general formula (2) as an essential component of the epoxy resin component. The mixing ratio of the epoxy resin and the curing agent is preferably, for example, in the range of 0.5 to 1.5 in terms of equivalent ratio between the epoxy group and the functional group in the curing agent.

When the epoxy resin represented by the general formula (2) is used as an essential component, any curing agent generally known as a curing agent for epoxy resins can be used. Examples include dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines, and the like. Specific examples of polyhydric phenols include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, resorcinol, naphthalenediol, and the like. Dihydric phenols, or tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolak, o-cresol novolak, naphthol novolak, polyvinylphenol, etc. Representative trihydric or higher phenols, further phenols, naphthols or bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcin, naphthalene diols and other divalent phenols such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and polyhydric phenolic compounds synthesized with condensing agents such as p-xylylene glycol. Phthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhimic anhydride, nadic anhydride, trimellitic anhydride and the like. As amines, aromatic amines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylsulfone, m-phenylenediamine and p-xylylenediamine, Aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine and triethylenetetramine can be used, and the polyvalent hydroxy compound represented by the general formula (1) of the present invention can also be used. One or a mixture of two or more of these curing agents can be used in the resin composition of the present invention. When the polyhydric hydroxy compound represented by the general formula (1) of the present invention is used as a curing agent, the compounding amount thereof is preferably in the range of 5 to 100 wt%, more preferably 50 to 100 wt% of the total curing agent. is in the range.

For the epoxy resin composition of the present invention, all ordinary epoxy resins having two or more epoxy groups in the molecule can be used in addition to the epoxy resin represented by the general formula (2). For example, bisphenol A, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, dihydric phenols such as resorcin, or tris-(4-hydroxyphenyl)methane , 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolak, o-cresol novolak, and other trihydric or higher phenols, or halogenated bisphenols, such as tetrabromobisphenol A There are glycidyl etherified products, polyfunctional epoxy resins represented by the above general formula (1), and the like. These epoxy resins can be used singly or in combination of two or more. In this case, the compounding amount of the epoxy resin of the present invention is preferably in the range of 5 to 100 wt%, more preferably in the range of 50 to 100 wt%, based on the total epoxy resin.

In the epoxy resin composition of the present invention, oligomers or polymer compounds such as polyesters, polyamides, polyimides, polyethers, polyurethanes, petroleum resins, indene cumarone resins, and phenoxy resins may be appropriately blended, or inorganic fillers may be added. Additives such as agents, pigments, flame retardants, thixotropic agents, coupling agents, fluidity improvers and the like may be added. Examples of inorganic fillers include spherical or crushed fused silica, silica powder such as crystalline silica, alumina powder, glass powder, mica, talc, calcium carbonate, alumina, hydrated alumina, and the like. Examples thereof include organic or inorganic extender pigments and scaly pigments. Examples of the thixotropic agent include silicon-based, castor oil-based, aliphatic amide wax, polyethylene oxide wax, organic bentonite-based, and the like.
Further, conventionally known curing accelerators can be used as necessary. Examples include amines, imidazoles, organic phosphines, Lewis acids and the like. The amount added is usually in the range of preferably 0.2 to 5 parts by weight, more preferably 0.5 to 2.0 parts by weight, per 100 parts by weight of the epoxy resin.
Further, if necessary, the resin composition of the present invention may contain a releasing agent such as carnauba wax or OP wax, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a coloring agent such as carbon black, Flame retardants such as antimony oxide, stress reducing agents such as silicone oil, and lubricants such as calcium stearate can be used.

The cured product of the present invention can be obtained by molding the epoxy resin composition by methods such as casting, compression molding and transfer molding. The temperature during molding is usually in the range of 120-220°C.

The present invention will be specifically described below based on examples and comparative examples.
Example 1
(Production of dihydroxy compound A)
A four-necked separable flask was charged with 16.2 g of 4-aminophenol, 24.6 g of 6-hydroxy-2-naphthaldehyde and 57 g of ethanol and dissolved. After 0.03 g of zinc chloride was added thereto, the temperature was raised to 70° C. After reacting for 4 hours, the mixture was cooled to room temperature and the precipitate was collected by filtration. This was washed twice with 0.5 L of water and then dried to obtain 35.1 g of a yellow crystalline product (dihydroxy compound A). The obtained dihydroxy compound A had a melting point of 217.7° C. and a hydroxyl equivalent of 108 g/eq. Met. Purity by GPC measurement was 99.6%.
Here, the melting point was measured using a DSC7020 differential scanning calorimeter manufactured by Hitachi High-Tech Science, and the endothermic peak temperature obtained at a heating rate of 10° C./min was taken as the melting point. Hydroxyl equivalents were determined by potentiometric titration with potassium hydroxide in acetyl chloride solution. GPC measurement was carried out using an apparatus: HLC-8320 (manufactured by Tosoh Corporation) and columns: TSKgel SuperHZ2500 x 2 and TSKgel SuperHZ2000 x 2 (both manufactured by Tosoh Corporation), solvent: tetrahydrofuran, flow rate: 0.5. 35 ml/min, temperature: 40° C., detector: RI. The infrared absorption spectrum was measured by the KBr tablet method using an FT/IR-6100 type infrared absorption spectrometer manufactured by JASCO Corporation. The ¹ H-NMR measurement was performed using a JNM-LA400 type measurement apparatus manufactured by JEOL.

Example 2
(Synthesis of epoxy resin A)
15 g of the dihydroxy compound A obtained in Example 1 was dissolved in 160 g of epichlorohydrin and 40 g of N-methylpyrrolidone, and under reduced pressure (about 100 mmHg), 9.3 g of a 48.8% aqueous sodium hydroxide solution was added dropwise at 60° C. over 4 hours. did. During this time, the generated water was removed from the system by azeotroping with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition was completed, the reaction was further continued for 1 hour. After cooling to room temperature and distilling off epichlorohydrin under reduced pressure, it was added dropwise to 4 L of distilled water. The precipitate was filtered and washed with water to obtain 20.8 g of yellowish brown crystalline epoxy resin (epoxy resin A). The obtained epoxy resin A had a melting point of 123.0° C. and an epoxy equivalent of 188 g/eq. , hydrolyzable chlorine was 260 ppm. The H-NMR spectrum of epoxy resin A is shown in FIG. 1, and the infrared absorption spectrum is shown in FIG. Tetrahydrofuran (THF-d8) was used as a solvent for H-NMR measurement.
Here, the epoxy equivalent was measured by performing potentiometric titration with perchloric acid in an acetic acid solution of tetraethylammonium bromide. Hydrolyzable chlorine was obtained by dissolving 0.5 g of a resin sample in 30 ml of 1,4-dioxane, boiling under reflux for 30 minutes in 5 ml of a 1N-KOH/methanol solution, and performing potentiometric titration with a silver nitrate solution. rice field.

Comparative example 1
(Synthesis of dihydroxy compound B)
Using 22.7 g of 4-aminophenol and 24.4 g of 4-hydroxybenzaldehyde, the reaction was carried out in the same manner as in Example 1 to obtain 40.2 g of a yellow crystalline product (dihydroxy compound B). The obtained dihydroxy compound B had a melting point of 217.4° C. and a hydroxyl equivalent of 88 g/eq. Met. Purity by GPC measurement was 99.6%.

Comparative Example 2 (synthesis of epoxy resin B)
Using 15 g of the dihydroxy compound B obtained in Comparative Example 1, the reaction was carried out in the same manner as in Example 2 to obtain 21.6 g of a yellowish brown crystalline epoxy resin (epoxy resin B). The obtained epoxy resin B had a melting point of 129.2° C. and an epoxy equivalent of 163 g/eq. , hydrolyzable chlorine was 320 ppm.

Examples 3, 4 and Comparative Examples 3-5
Epoxy resin A synthesized in Example 2, epoxy resin B synthesized in Comparative Example 2, biphenyl epoxy resin (epoxy resin C: YX-4000H manufactured by Mitsubishi Chemical, epoxy equivalent 193, melting point 105° C.), 4,4′ - Dihydroxydiphenyl ether (curing agent A), phenol novolac (curing agent B; BRG-557 manufactured by Aica Kogyo Co., Ltd., hydroxyl equivalent 104, softening point 83 ° C., melt viscosity at 150 ° C. 0.3 Pa s) to accelerate curing Using triphenylphosphine as an agent, a resin composition having the composition shown in Table 1 was prepared.
After molding (150° C., 5 minutes) using this, post-curing (175° C., 4 hours) was performed to obtain test pieces, which were subjected to various physical property tests. The test method is as follows. Table 1 shows the results.

[evaluation]
(1) Thermal conductivity Measured by the unsteady hot wire method using a NETZSCH LFA447 thermal conductivity meter.
(2) Linear expansion coefficient and glass transition temperature Measured at a heating rate of 10°C/min using a TMA7100 type thermomechanical measurement device manufactured by Hitachi High-Tech Science.
(3) Remaining coal rate Using a TG/DTA7300 type thermogravimetric analyzer manufactured by Hitachi High-Tech Science, the residual coal rate was determined at 700°C under a nitrogen stream at a heating rate of 10°C/min.
(4) Water Absorption A disk having a diameter of 50 mm and a thickness of 3 mm was molded, and after post-curing, it was subjected to moisture absorption for 100 hours under the conditions of 85° C. and 85% relative humidity, and the weight change rate was obtained.
(5) Flame Retardancy UL94 test was performed using a cured product test piece filled with 83 wt % of spherical silica, and the total burning time of five test pieces was evaluated.

Claims (5)

the following general formula (1),

(However, n represents a number from 0 to 1.). the following general formula (2),

(However, n represents a number from 0 to 1 and m represents a number from 0 to 50.). 3. The method for producing an epoxy resin according to claim 2, wherein the dihydroxy compound according to claim 1 and epichlorohydrin are reacted. An epoxy resin composition comprising an epoxy resin and a curing agent, wherein the epoxy resin composition according to claim 2 is blended. A cured product obtained by curing the epoxy resin composition according to claim 4 .

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