JP2001192432A - Flame-retardant epoxy resin, epoxy resin composition and its cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cured product having sufficient flame retardance and excellent heat resistance, not containing a halogen, an epoxy resin and an epoxy resin composition providing the cured material. SOLUTION: This epoxy resin is represented by formula (1) (Y is a structure of formula (2) ; X is a residue after removal of one or more kinds of hydroxyl groups from a substance selected from a group consisting of a bisphenol, a dihydroxybenzene and a dihydroxynaphthalene; the orders of X-containing repeating unit and Y-containing repeating unit are arbitrary; m and n are each a positive number and shows an average value).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin, a halogen-free epoxy resin, an epoxy resin composition and a cured product thereof.

[0002]

2. Description of the Related Art Epoxy resins can be cured with various curing agents to give cured products having generally excellent mechanical properties, water resistance, chemical resistance, heat resistance, and electrical properties. It is used in a wide range of fields, such as laminates, molding materials, and casting materials. Conventionally, bisphenol A type epoxy resin has been most commonly used as an epoxy resin. However, when used for electronic and electric parts, these parts are required to have safety against fire and thus are flame retardant. Epoxy resin is used. Epoxidized tetrabromobisphenol A is widely known as a flame-retardant epoxy resin.

[0003]

However, it has been pointed out in recent years that epoxidized tetrabromobisphenol A contains bromo and may generate toxic substances when incinerated at the time of disposal. In order to solve such problems, a method of adding a phosphorus compound to a resin composition has been proposed. However, it has been pointed out that generally, addition-type phosphorus compounds do not have reactivity with the epoxy resin composition, and thus, physical properties such as heat resistance of a cured product are reduced.

[0004]

Means for Solving the Problems In view of these circumstances, the present inventors have conducted intensive studies for a flame-retardant epoxy resin that does not contain halogens and does not deteriorate the physical properties of a cured product. The inventors have found that an epoxy resin having a structure satisfies these requirements, and have completed the present invention.

That is, the present invention provides the following equation (1).

[0006]

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(Where Y is the equation (2)

[0008]

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Wherein X represents a residue excluding one or more hydroxyl groups selected from the group consisting of bisphenols, dihydroxybenzenes and dihydroxynaphthalenes. The order of the repeating unit containing X and the repeating unit containing Y is arbitrary. m and n are positive numbers and represent average values. (2) (a)
The epoxy resin composition comprising the epoxy resin (b) curing agent according to the above (1), (3) the epoxy resin composition according to the above (2) containing a curing accelerator, (4) the above (2) Alternatively, the present invention provides a cured product obtained by curing the epoxy resin composition according to (3).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The compound represented by the formula (1) is, for example, a compound represented by the formula (3)

[0011]

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And a bisphenol-type and / or dihydroxybenzene-type and / or dihydroxynaphthalene-type epoxy resin (hereinafter referred to as a raw material epoxy resin). Can be. The compound of the formula (3) can be obtained, for example, by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 1,4-benzoquinone.

Specific examples of the raw material epoxy resin that can be used include bisphenols such as bisphenol A, bisphenol F and bisphenol S, dihydroxybenzene,
One or more selected from glycidyl ethers such as dihydroxybenzenes such as ditertiary butyl dihydroxybenzene and dihydroxynaphthalenes such as dihydroxynaphthalene, and glycidyl ethers of bisphenols are preferable. It should be noted that some glycidyl etherified bisphenols contain 3 per molecule.
Some of them contain more than one phenolic hydroxyl group, but glycidyl etherified bisphenols containing such molecules may be used as a raw material.

In the condensation reaction for obtaining the epoxy resin of the present invention, an organic solvent may be used. As the organic solvent, toluene, methyl isobutyl ketone and the like can be used. When an organic solvent is used, it is used in an amount of usually 10 to 300% by weight, preferably 20 to 2% by weight, based on the total weight of the epoxy resin as the raw material and the compound represented by the formula (3).
00% by weight. The reaction time is usually 20 minutes to 10 hours,
Preferably, it is 30 minutes to 5 hours. The reaction temperature is usually 70
To 200 ° C, preferably 80 to 170 ° C.

In the above condensation reaction, it is also possible to accelerate the reaction rate by using a catalyst. Specific examples of the catalyst that can be used in this case include triphenylphosphine, tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, aqueous sodium hydroxide, aqueous potassium hydroxide, and the like. The amount of these catalysts used is usually 0.01 to 1 equivalent of the epoxy group of the raw material epoxy resin.
It is 10 parts by weight, preferably 0.05 to 5 parts by weight.
Even if phosphorus-containing compounds are used as the catalyst, they have little effect on the physical properties of the cured product because they are used only in small amounts. The same applies to the case where a phosphorus-containing compound is used as a curing catalyst in the later-described epoxy resin composition of the present invention.

The epoxy resin of the present invention usually has a softening point of 50.
The softening point can be controlled by changing the ratio of the number of equivalents of the epoxy group of the raw material epoxy resin to the number of equivalents of the hydroxyl group of the compound represented by the formula (3). The ratio of the number of equivalents of the epoxy group of the raw material epoxy resin to the number of equivalents of the hydroxyl group of the compound represented by the formula (3) is usually 1: 0.95 to 1: 0.05, preferably 1: 0. 9 to 1: 0.1. When the equivalent ratio of the starting epoxy resin and the compound of the formula (3) approaches an equivalent weight, the average molecular weight of the obtained epoxy resin increases and the softening point increases. The thus obtained epoxy resin of the present invention is represented by the formula (1). In addition, in Formula (1), n and m represent the average value in which the repeating unit containing X and Y is included in the molecule, and usually n = 0.1 to 5, preferably 0.2 to 5.
4, m = 0.1 to 5, preferably 0.2 to 4.

Hereinafter, the epoxy resin composition of the present invention will be described. In the epoxy resin composition of the present invention, the epoxy resin of the present invention can be used alone or in combination with another epoxy resin. When used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin is preferably at least 10% by weight, particularly preferably at least 20% by weight.

Specific examples of other epoxy resins that can be used in combination with the epoxy resin of the present invention include novolak epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, biphenyl epoxy resins, and triphenylmethane epoxy resins. These may be used alone or in combination of two or more.

The curing agent used in the epoxy resin composition of the present invention includes, for example, amine compounds, acid anhydride compounds, amide compounds, phenol compounds and the like. Specific examples of the curing agent that can be used include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, phthalic anhydride, and trianhydride. Melitic acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride,
Examples include methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolak, and modified products thereof, imidazole, BF ₃ -amine complex, and guanidine derivative. It is not limited to these. These may be used alone or in combination of two or more.

The amount of the curing agent used in the epoxy resin composition of the present invention is usually 0.7 to 1.2 equivalents per equivalent of the epoxy group of the epoxy resin. When less than 0.7 equivalent per 1 equivalent of epoxy group, or 1.2 equivalents
If it exceeds the equivalent, curing may be incomplete in any case, and good cured physical properties may not be obtained.

When the above curing agent is used, a curing accelerator may be used in combination. Specific examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, and 1,8-diaza. Tertiary amines such as -bicyclo (5,4,0) undecene-7; phosphines such as triphenylphosphine; and metal compounds such as tin octylate. The curing accelerator is usually used in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin as required.

The epoxy resin composition of the present invention may contain an inorganic filler if necessary. Specific examples of the inorganic filler that can be used include silica, alumina, and talc. The inorganic filler is 0 to 10 in the epoxy resin composition of the present invention.
An amount occupying 90% by weight is used. Further, to the epoxy resin composition of the present invention, various compounding agents such as a silane coupling agent, a release agent such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, and a pigment can be added.

The epoxy resin composition of the present invention can be obtained by uniformly mixing the components. The epoxy resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, the epoxy resin of the present invention, a curing agent, and, if necessary, a curing accelerator, an inorganic filler and a compounding agent, if necessary, may be used in an extruder, a kneader, a roller,
The epoxy resin composition is sufficiently mixed until the epoxy resin composition becomes uniform using a tool or the like. The epoxy resin composition is melted and then molded using a casting or transfer molding machine. A cured product can be obtained by heating for 10 to 10 hours.

Further, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like, and is used to prepare glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc. A prepreg obtained by impregnating a base material and heating and semi-drying can be subjected to hot press molding to obtain a cured product. The solvent in this case is usually 10 to 70% by weight, preferably 1% by weight in the mixture of the epoxy resin composition of the present invention and the solvent.
An amount occupying 5 to 70% by weight is used.

[0025]

EXAMPLES The present invention will be described more specifically with reference to the following Examples, in which parts are by weight unless otherwise specified.

Example 1 A liquid bisphenol A type epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 186 g) was purged with nitrogen gas in a flask equipped with a thermometer, a dropping funnel, a cooling tube, and a stirrer. / Eq) 93
And 40.5 parts of the compound represented by the formula (3), and the mixture was heated to 160 ° C. with stirring. Then, 0.25 parts of triphenylphosphine is added, and the mixture is reacted at 160 ° C. for 1 hour to obtain the following formula (4)

[0027]

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(Wherein the repeating unit containing the residue of bisphenol A and the repeating unit containing the residue of formula (3) are arranged in any order. In addition, m = 1.29, n = 1.1
4 (both average values). 133.5 parts of the epoxy resin (A) of the present invention represented by the formula (1) was obtained. The epoxy resin obtained has an epoxy equivalent of 570 g / eq and a softening point of 10
4.3 ° C.

Embodiment 2 As Embodiment 2, the following formula (5) is used instead of the epicoat 828 in Embodiment 1.

[0030]

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The crystalline epoxy resin represented by the formula (YDC-
1312, manufactured by Toto Kasei Co., Ltd., epoxy equivalent 178 g /
eq) The reaction was carried out in the same manner as in Example 1 except for using 89 parts, and the following formula (6)

[0032]

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(In the formula, t-Bu represents a tertiary butyl group, and the repeating unit containing the residue of YDC-1312 and the repeating unit containing the residue of the compound of formula (3) are arranged in any order. M = 1.32, n = 1.1
6 (both averages). ) Was obtained in an amount of 129.5 parts. The epoxy equivalent of the obtained epoxy resin (B) was 510 g / eq, and the softening point was 120.3 ° C.

Examples 3 and 4 Epoxy resins (A) and (B) obtained in Examples 1 and 2
Phenol novolak (softening point 83
, A hydroxyl group equivalent of 106 g / eq) was blended at a composition shown in Table 1 using 2-ethyl-4-methylimidazole (2E4MZ) as a curing accelerator, and then melt-mixed at 100 ° C and heated at 150 ° C. Use a plate press to set the thickness to 0.
A 7 mm cured product was molded and further post-cured at 150 ° C. for 1 hour. Next, this cured product was 127 mm in length and 1 in width.
A test piece was prepared by molding to a size of 2.7 mm, and the glass transition temperature was measured under the V-0 test in UL standard and the following conditions. The results are shown in Table 1. In Table 1, the numerical values in the column of the composition of the compound represent parts.

V-0 test Those which passed the standard are indicated by ○. Glass transition point Thermomechanical analyzer (TMA): TM- manufactured by Vacuum Riko Co., Ltd.
7000 Heating rate: 2 ° C / min

Table 1 Example 3 Example 4 Composition of Formulation Epoxy Resin (A) 100 Epoxy Resin (B) 100 Phenol Novolak 18.6 20.8 2E4MZ 11 1 Physical Properties of Cured Product V-0 Test ○ ○ Glass Transition Point (° C) 131 135

As described above, the cured product of the epoxy resin of the present invention showed sufficient heat resistance and passed the V-0 test without containing halogen.

[0038]

The epoxy resin of the present invention, unlike the flame-retardant epoxy resin generally used in the prior art, shows sufficient flame retardancy and cured physical properties despite containing no halogen. Therefore, the epoxy resin of the present invention is an electric / electronic material,
It is extremely useful for a wide range of applications such as molding materials, casting materials, laminate materials, paints, adhesives, resists, and optical materials.

Claims (4)

[Claims] (1) Formula (1) (Where Y is the formula (2) Wherein X represents a residue excluding one or more hydroxyl groups selected from the group consisting of bisphenols, dihydroxybenzenes and dihydroxynaphthalenes. The order of the repeating unit containing X and the repeating unit containing Y is arbitrary. m and n are positive numbers and represent average values. Epoxy resin represented by). 2. An epoxy resin composition comprising (a) the epoxy resin according to claim 1 and (b) a curing agent. 3. The epoxy resin composition according to claim 2, further comprising a curing accelerator. 4. A cured product obtained by curing the epoxy resin composition according to claim 2 or 3.