JPH0232114A - Flame-retardant epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition for electric or electronic material, etc., providing a composition having excellent high-temperature dimensional stability and heat-resistance and resistant to the separation of components by reducing the content of polymer produced during the production or storage of a specific monoglycidyl ether. CONSTITUTION:The objective composition is produced by compounding (A) an epoxy resin having >=2 epoxy groups in one molecule, (B) a brominated alkylphenyl monoglycidyl ether of formula (R is 3-4C alkyl; n is 1-3) and (C) a curing agent. Preferably, the content of the polymer of the component B produced during the production and storage of the component B is decreased to <=1.0% based on the component B by distilling the component B at 140-250 deg.C under 0.1-150Torr.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flame-retardant epoxy resin composition.

(Prior art) Epoxy resins exhibit excellent adhesive properties, chemical resistance, electrical and mechanical properties, and moldability, and are therefore used in a wide range of applications such as adhesives, paints, and electrical/electronic insulating materials. There is.

Recently, with the miniaturization and higher performance of electronic device parts, importance has been placed on heat resistance, moisture resistance, flame retardance, etc., and similar requirements are being placed on the epoxy resin compositions used in these electrical products. It came out.

Traditionally, flame-retardant resins include additive-type ones that add flame retardants to the resin, so-called reactive-type flame retardants that react with flame-retardant components, and resins that are themselves flame-retardant resins. Are known.

Examples of additive-type flame retardants include flame-retardant organic halides (tetrabromobisphenol A, hexabromobenzene, etc.), inorganic compounds (antimony trioxide, aluminum hydroxide, etc.), and phosphoric acid esters. has been used.

However, when these additive flame retardants are added to resins, there are drawbacks such as a decrease in heat resistance and a decrease in mechanical properties.

Tetrabromobisphenol A glycidyl ether, dibromocresol glycidyl ether, etc. have been used as reactive flame retardants, but these are not satisfactory in terms of mechanical properties, decreases in heat resistance, and decreases in processability. There wasn't.

Flame-retardant epoxy resins include epoxy resins based on halogenated bisphenol A and epichlorohydrin condensate, and brominated phenol novolac epoxy resins, which provide excellent flame-retardant cured products with heat resistance, but solid or Other epoxy resin hardeners, because they are semi-solid
When mixing with a filler, it is necessary to lower the viscosity by heating or by using a solvent or the like.

In addition, epoxy resin compositions generally use an epoxy resin having two or more epoxy groups in one molecule as a base resin, and blend a bromine-based phosphorus-based organic flame retardant and an inorganic flame retardant singly or simultaneously. Moreover, acid anhydride,
Curing agent DBtJ for amines, phenol novolacs, etc.
, crystalline silica, fused silica, glass fiber,
This is because thermosetting products are created by adding fillers such as mica or impregnating sheets or cloth such as paper, glass cloth, or polyester cloth without adding fillers and applying heat and pressure to the bond. A major problem has been controlling the balance of compatibility, wettability, etc. of compounded materials and preventing material separation.

[Problem to be solved by the invention]

The present inventors investigated methods for eliminating various drawbacks of epoxy resin compositions using conventionally known flame retardants.
We have discovered a new flame-retardant epoxy resin composition found in No. 4). However, the present inventors conducted intensive studies with the aim of improving the material separation properties of the composition containing brominated alkylphenyl monoglycidyl ether in the above composition. It has also been found that the material separation property of the epoxy resin composition can be improved by reducing the proportion of the polymer produced during storage in the flame-retardant epoxy resin composition.

In other words, the present inventors believe that when the corresponding epoxy resin composition is thermally cured, the striped pattern caused by material separation that occurs in the cured product is caused by the compatibility, wettability, etc. of the flame retardant to be blended with other materials. Considering this, we compared the compatibility with various solvents and found that brominated phenol monoglycidyl ether flame retardants, which cause material separation, have poor compatibility with methanol and become cloudy when mixed. became.

Regarding the cause of this, we conducted a rough comparison using gel permeation chromatography (abbreviated as GPC), and it became clear that several percent of polymers derived from brominated alkylphenyl monoglycidyl ether were present in those that caused waste material separation. It was confirmed that material separation does not occur when the amount of this polymer is 1% or less based on the brominated alkylphenyl monoglycidyl ether.

(Means for Solving the Problems) The gist of the present invention is to use an epoxy resin having two or more epoxy groups in one molecule and a general formula (I) (wherein R is an alkyl group having 3 to 4 carbon atoms, (n is an integer of 1 to 3) A composition containing a brominated alkylphenyl monoglycidyl ether represented by the formula (n is an integer of 1 to 3) and a curing agent, in which a polymer of compound CI) generated during the manufacturing process and storage of compound CI). The present invention provides a flame-retardant epoxy resin composition characterized in that the content of the compound (I) is 1.0% or less based on compound (I), thereby achieving the intended purpose.

[For production]

The brominated alkylphenyl monoglycidyl ether used in the present invention is represented by the general formula (I) (wherein R is an alkyl group having 3 to 4 carbon atoms, and n is an integer of 1 to 3). In the manufacturing process or storage, the amount of polymer produced is limited to 1% or less based on compound (I).

As a method for reducing the amount of polymer produced during the production and storage of compound (CI) to 1% or less based on compound (I),
1) at 140°C to 250°C, 0, ITOrr to 150
TOrr, preferably 160°C to 180°C, 1
It may be purified by distillation (single irradiation, thin film irradiation, etc.) at Torr to 20 Torr.

Also, by selecting the reaction and washing conditions for compound (I), it is possible to reduce the amount of polymer to 1% or less.

Specifically, the brominated alkylphenyl monoglycidyl ether used in the present invention was previously disclosed by the present inventors in Japanese Patent Application No. 58-206293 (Japanese Patent Publication No. 60-38387).
and Japanese Patent Application No. 59-8538ρ (Japanese Unexamined Patent Application No. 60-2284)
Examples include dibromo-1-butylphenylglycidyl ether, dibromo-isopropylphenylglycidyl ether, tribromo-isopropylphenylglycidyl ether, and dibromo-n-butylphenylglycidyl ether developed in No. 69). These can also be used as isomer mixtures of brominated alkylphenyl glycidyl ethers, or as compositions in which the above-mentioned brominated alkylphenyl glycidyl ethers are suitably blended as two-component or more multi-component systems.

The blending ratio of this brominated alkylphenyl glycidyl ether to the epoxy resin is conveniently 5 to 40% (by weight).

On the other hand, the epoxy resin used in the present invention contains 2
Examples include polyhydric phenols such as bisphenol A1 catechol, novolak-type polyhydric phenols such as phenol or cresol, and aliphatic polyhydric carboxylic acid glycidyl ether.

Further, the curing agent used in curing the composition of the present invention is an amine-based curing agent that is already known as a known curing agent, such as ethylamine, triethanolamine, dicyandiamide,
Diaminodiphenylmethane, trifluoride monoethylamine, etc., as imidazole type, ethylmethylimidazole, phenylimidazole, other 1,8-diaza-bicyclo(5,4,0)undecene-7, acid anhydride: Examples include phthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, and trimethic anhydride.

In order to further improve the heat resistance of the composition of the present invention, other flame retardant additives such as antimony trioxide, aluminum hydroxide, tris(2,3-bromopropyl) phosphate, etc. may be blended to obtain a synergistic effect. I can do it.

In addition, this composition may contain fillers, colorants, etc., such as alumina, calcium carbonate, quartz glass powder, fused silicon powder, etc., or may contain no filler,
It is also possible to impregnate base materials such as glass cloth and paper.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Table 1 shows the compounded materials other than the flame retardant used in each Example and Comparative Example.

In addition, the formulations and test results in Examples 1 to 7 and Comparative Examples 1 to 5 are shown in Table 2.

In Examples 1 to 7 and Comparative Examples 1 to 5, the base resin (Epicoat 828) and the epoxy resin including the flame retardant and the curing agent were mixed in a stoichiometric ratio of approximately 1:1, and the filler and mold release agent were mixed. Blending was carried out with the bromine content in the resin portion other than that being approximately 10%. The curing conditions were 105° C. for 150 minutes and prepared as follows. The methods for evaluating material separation and alcohol compatibility are shown below.

Preparation method of cured product Each sample was taken into a 200-volume polypropylene despot cup at the blending ratio shown in Table 2 (filler was added last), and thoroughly stirred using a stirring bar. This is placed in a vacuum dryer whose humidity is adjusted to 50 to 60°C, and degassed under vacuum at 70 to 7 eCIIIHg for about 30 minutes.

Next, a glass test tube coated with a mold release agent in advance <lj! Outer diameter 1
A defoamed sample of 8#x length 160ar) is collected for about 8 minutes and left in a blow dryer kept at 75°C for 20 minutes. Immediately lower the internal temperature to 105
℃ and leave it for 150 minutes to harden (from 75℃
(including the time to raise the temperature to 105°C).

The striped pattern generated on the surface of the cured product was visually observed and evaluated.

Alcohol compatibility test method: Pour 10 d of methanol into a sample tube and drop 3 g of the sample flame retardant into it for about 30 seconds lW! Shake vigorously.

The degree of cloudiness was visually evaluated 30 seconds after the end of shaking.

1) Preparation of polymer, preparation of flame retardant sample To prepare the polymer, 5% NaOH aqueous solution was added to each of the three flame retardants used in Examples 1 to 7 at a ratio of 20:1, and reacted at 100°C for 8 hours. The gel permutation chromagram (GPC) of the reaction product was measured. A GPC chart of the reactant containing the polymer is shown in FIG. GP the polymer
The flame retardant concentration of each polymer was adjusted based on the pure content based on the C chart area.

2) According to VL-95 standard.

(Effects of the Invention) According to the present invention, the composition not only has high heat resistance, dimensional stability, and thermal shock resistance, but also has improved wettability, compatibility, etc. of the constituent components in the cured product, making it difficult to separate the materials. From the Examples and Comparative Examples shown above, it is believed that the epoxy resin composition according to the present invention has little material separation and can be widely applied to electrical and electronic materials.

[Brief explanation of the drawing]

Figure 1 shows a GPC chart of the polymer with peaks 1, 2.
3 is a peak corresponding to the polymer of compound [■] (peak 4).

Claims (2)

[Claims] (1) Epoxy resins with two or more epoxy groups in one molecule and general formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [I] (In the formula, R is an alkyl group with 3 to 4 carbon atoms, n is an integer from 1 to 3) A composition containing a brominated alkylphenyl monoglycidyl ether and a curing agent, in which a compound [I] generated during the manufacturing process and storage of the compound [I]
A flame-retardant epoxy resin composition characterized in that the content of the polymer is 1.0% or less based on the compound [I]. (2) Brominated alkylphenyl monoglycidyl ether represented by general formula [I] at 140-250°C, 0.1
Compound [I] produced during the manufacturing process and storage of compound [I] by distillation purification at ~150 Torr
] content of polymer is 1.0% with respect to compound [I]
The method for producing the composition according to claim 1, which is as follows.