JPH03199221A - Polyphenols and curing agent for epoxy resin, comprising same polyphenols as main component - Google Patents

Abstract

PURPOSE:To obtain a polyphenol providing a cured material of epoxy resin having excellent heat resistance by blending an epoxy resin with the polyphenol as a curing agent by condensing a phenol with a phenolic hydroxyl group- containing carbonyl compound and polycarbonyl compound. CONSTITUTION:A phenol (e.g. phenol or resorcinol) is condensed with a carbonyl compound prepared by blending a phenolic hydroxyl group-containing carbonyl compound (e.g. salicylaldehyde) and a polycarbonyl compound (e.g. glyoxal) in a ratio of preferably (0.9:1.5)-(0.5:0.5) (molar ratio) to give a polyphenol suitable as a curing agent for casting or molding epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to polyphenols obtained by condensing phenols with a multi-mi carbonyl compound.

Furthermore, for casting, acid molding, lamination, paint, adhesive, etc.
Epoxy resin used in a wide range of applications & I! Concerning hardening agents used in sacraments.

(Prior Art) Epoxy resins have excellent adhesive properties, processability, solvent resistance, etc., and are used in a wide range of applications.

However, with remarkable technological progress in recent years, higher performance, particularly heat resistance, is required in each application field.

In addition to improving the epoxy resin itself, methods for improving the heat resistance of epoxy resins include changing the curing agent.

Examples of curing agents for epoxy resins include amine compounds, acid anhydrides, and phenol compounds.

Generally, when amine compounds are used, they have poor water resistance and also have toxicity problems.

In addition, acid anhydride cures slowly, and the cured product has poor water resistance.
It has the disadvantage of poor adhesion.

As a substitute for these, phenol novolaks, which have well-balanced heat resistance and water resistance, are used, particularly in the field of molding materials.

However, with the recent progress in semiconductor technology, phenol novolak-based curing agents are increasingly used in applications where heat resistance is insufficient.

For example, currently O-
The mainstream is to cure glycidyl ether of cresol novolak with phenol novolac, but recently there has been an increasing demand for high heat resistance due to higher integration of ICs or surface mounting, which requires immersion in solder baths. ing.

Regarding curing agents for epoxy resins aiming at high heat resistance, for example, JP-A No. 58-198526 discloses tris(hydroxyphenyl)methane, and JP-A No. 63-228
Publication No. 24 discloses the reduction of phenols and salicylaldehyde.

<Problems to be Solved by the Invention> - When the heat resistance of the cured epoxy resin is improved in g, the moisture resistance tends to decrease.

Although the material disclosed in the above-mentioned Japanese Patent Application Laid-open No. 198526/1983 is intended to improve heat resistance, it is still not sufficient and has low temperature resistance.

The material disclosed in JP-A-63-22824 is also desired to have further improved heat resistance and moisture resistance.

An object of the present invention is to provide a curing agent that allows an epoxy resin composition to have well-balanced properties, with both high heat resistance and moisture resistance.

<Means for Solving the Problems> The present invention is a polyphenol obtained by co-condensation of a phenol, an aromatic carbonyl compound having a phenolic hydroxyl group, and a polycarbonyl compound.

Furthermore, it is a curing agent for epoxy resin containing the polyphenols as a main component.

The phenols used in the present invention are compounds having at least one phenolic hydroxyl group in an aromatic ring.

Specific examples include unsubstituted phenols such as phenol, resorcinol, and hydroquinone; mono-monotype phenols such as cresol, ethylphenol, n-propylphenol, i-propylphenol, t-butylphenol, octylphenol, nonylphenol, and phenylphenol. ; Disubstituted phenols such as xylenol, methylpropylphenol, methylbutylphenol, methylhexylphenol, dipropylphenol, dibutylphenol; Trisubstituted phenols represented by nitrimethylphenol; Naphthols such as naphthol, methylnaphthol; biphenol, bisphenol -A,
Examples include bisphenols such as bisphenol-F.

Furthermore, for the purpose of imparting flame retardancy to the above phenols,
Furthermore, those into which halogens are introduced, such as chloro group and bromine group, are also included.

These phenols may be used alone or in combination of two or more.

The aromatic carbonyl compound having a phenolic hydroxyl group of the present invention is a compound having at least one phenolic hydroxyl group and at least one carbonyl group such as an aldehyde ketone in the molecule, and has moisture resistance and flame retardancy. This also applies to those in which the Hensen ring is substituted with an alkoxy group, an alkyl group, a halogen, etc. in order to provide the following.

Specific examples include salicylaldehyde, 0-hydroxybenzaldehyde, hydroxybenzaldehydes such as vanillin and invanillin, and hydroxyacetophenone.

The aromatic carbonyl compound having a phenolic hydroxyl group may be used alone or in combination of two or more.

The polycarbonyl compound used in the present invention is an organic compound having a plurality of carbonyl groups in the molecule.

Specific examples include dialdehydes such as glyoxal, glutaraldehyde, and phthalaldehyde.

The polycarbonyl compound may be used alone or in combination of two or more.

The ratio of the aromatic carbonyl compound having a phenolic hydroxyl group to the polycarbonyl compound is 0.95:0 in molar ratio.
．． 05~o, t:o, q, preferably 0.91.1
~0.5=0.5.

Although the moisture resistance of the cured epoxo resin improves as the ratio of the polycarbonyl compound increases, the heat resistance tends to decrease, so it should be adjusted appropriately depending on the intended use.

Further, the co-condensation reaction between phenols and the above-mentioned carbonyl compounds can be carried out by a well-known method for novolak synthesis.

In other words, known acidic catalysts, such as inorganic acids such as hydrochloric acid and sulfuric acid,
In the presence of organic acids such as toluenesulfonic acid, zinc acetate, etc.
This is done by heating and mixing.

Regarding the ratio of phenols and carbonyl compounds, phenols are used in excess.

Even within this range, increasing the ratio of carbonyl compounds increases the average molecular weight and increases the heat resistance of the cured epoxy resin, but the viscosity of the epoxy resin Mi acid product before curing also increases, so it is difficult to use. Select as appropriate.

As the epoxy resin using the polyphenols of the present invention as a curing agent, known epoxy resins are applicable.

For example, bisphenol A1 bisphenol F1 bisphenol AD, brominated bisphenol A, resorcinol,
Glycidyl ethers of diphenols such as hydroquinone; phenol novolank, talesol novolank, resorcinnopolasoc, trihydroxyphenylmethane,
Glycidyl ethers such as trihydroxyphenylpropane, tetrahydroxyphenylethane, polyvinylphenol, polyisopropenylphenol; glycidyl ethers of polyhydric phenols obtained by condensation reaction of phenols and aromatic carbonyl compounds; diaminodiphenylmethane, aminophenol, etc. Glycidylamines; alicyclic epoxy resins such as vinyl cyclohexene dioxide, alicyloxygepoxy acecool, alisilicyl dieboxycarboxylate, etc.; heterocyclic epoxy resins such as hydantoin type epoxy resins, triglycidyl isocyanurate, etc. .

The amount of the polyphenol curing agent used in the present invention is such that the amount of phenolic hydroxyl group is 0.2 to 1.5 equivalents to glycidyl group.

Furthermore, the composition of the curing agent and epoxy resin of the present invention includes:
Other curing agents, fillers, curing accelerators, mold release agents, if necessary.
Known additives such as flame retardants and surface treatment agents can be added.

Transfer molding, compression molding, injection molding, etc. can be used to resin-seal electronic components such as semiconductors using the composition of the curing agent and epoxy resin of the present invention, and especially when the resin composition is in a liquid state, Conventionally known molding methods such as casting, dipping, and dromping are applied.

In addition, in order to use the resin composition for laminates, the resin m-acid is uniformly melted using a medium (such as methyl ethyl ketone, toluene, or ethylene glycol monomethyl ether), and glass fibers or organic fibers are impregnated with this. This may be dried by heating to form a prepreg, which may then be press-molded.

<Effects of the Invention> The polyphenols of the present invention are useful as curing agents for epoxy resins.

By using the polyphenols of the present invention as a curing agent, it has higher heat resistance, moisture resistance, and
A cured molded product with well-balanced moldability etc. can be obtained.

In addition, if the polyphenols are converted into glycidyl ether using a well-known technique, an epoxy resin having high heat resistance and moisture resistance can be obtained.

(Example> The present invention will be explained below with reference to Examples.

Here, the evaluation items and methods for the cured molded product used are as follows.

- Glass transition temperature (Tg): Measured using a thermomechanical analyzer (TMAIO type manufactured by Seiko Electronics Co., Ltd.).

・Water absorption rate (pressure kunker test) Two test pieces with a size of 20 w x 25 m* x 2 mm were taken out from the cured nibless molded product and placed in a high-pressure steam environment tester (PC-3053 manufactured by Tade Seisakusho). Put it in the room at 121℃,
The weight increase of the test piece was measured at 2 atmospheres over 20 hours and expressed as a percentage.

Note that this water absorption rate is an index of moisture resistance.

Reference Examples 1 to 7, Comparative Reference Examples 1 to 2 Table 1 was placed in a reactor equipped with a thermometer, stirrer, and condenser.
phenols, an aromatic carbonyl compound having a phenolic hydroxyl group, and a polycarbonyl compound in the amounts described in , and p-)luenesulfonic acid (-) as a catalyst.
After adding 1 g of water salt) and precondensing at 50°C for 2 hours, GPC (
10%
Neutralized with aqueous caustic soda solution.

Subsequently, after washing with water five times, unreacted monomers were distilled off by vapor distillation to obtain the desired polyphenols.

Examples 1 to 7, Comparative Examples 1 to 3 As an epoxy resin, glycidyl ether of polyphenol obtained by condensation of phenols and hydroxyhenzaldehyde (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumi Epoxy ESX-221, epoxy equivalent: 210 )210g,
Various polyhydric phenols shown in Table 2 as a curing agent and 3.2 g of triphenylphosphine as a curing accelerator were blended, heated and kneaded with rolls, and then bottom-pressed at 175° C. for 5 minutes.

Further, post-curing was performed for 5 hours in an oven at 180° C. to obtain a cured molded product.

The glass transition temperature and water absorption rate of this cured molded product were measured.

The results are shown in Table 2.

Claims (2)

[Claims] (1) Polyphenols obtained by co-condensation of phenols, aromatic carbonyl compounds containing phenolic hydroxyl groups, and polycarbonyl compounds. (2) A curing agent for epoxy resin containing the polyphenols according to claim (1) as a main component.