JPH05214068A - Phosphorus-containing epoxy resin and its production - Google Patents

Abstract

PURPOSE:To obtain the title resin excellent in burning resistance, heat resistance, etc., and capable of suppressing the formation of noxious gases in case of fire by reacting diphenylphosphinylhydroquinone with an epihalohydrin. CONSTITUTION:Diphenylphosphine oxide of formula I is reacted with 1,4- benzoquinone to produce diphenylphosphinylhydroquinone of formula II. The obtained product is reacted with an epihalohydrin (e.g. epichlorohydrin) to obtain the title resin of formula III (wherein R1 and R2 are each H lower alkyl or halogen; and n is 0-7). The above product may be reacted with diphenylphosphinylhydroquinone diglycidyl ether to obtain the title resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a phosphorus-containing epoxy resin and a method for producing the same. More specifically, the present invention relates to a novel phosphorus-containing epoxy compound capable of forming an epoxy resin cured product having a high degree of flame retardancy and excellent heat resistance, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, halogen-containing epoxy compounds such as diglycidyl ether of tetrabromobisphenol A and polyglycidyl ether of brominated phenol novolac have been used as flame-retardant epoxy resins. However, these flame-retardant epoxy resins have low electrical insulation properties, heat resistance, and strength, and it is difficult to maintain the original excellent properties of the epoxy resin, and moreover, there is a possibility that a toxic gas is generated during a fire.

On the other hand, as phosphorus-based flame retardants so far,
Phosphate ester compounds are widely used, but when such a phosphorus-based flame retardant is added to an epoxy resin, there has been a problem that the water resistance, heat resistance, etc. of the epoxy resin deteriorate.

As the phosphorus-containing epoxy compound, an aromatic compound in which a phosphorus atom is incorporated in a skeletal chain (Japanese Patent Application Laid-Open No. 61-134395)
JP-A-62-223215) and aliphatic ether compounds (JP-A-62-223215). However, an epoxy compound having a phosphorus atom in the side chain represented by the general formula (I) described later is not known.

The present inventors have synthesized a large number of phosphorus-containing epoxy compounds in order to achieve the above-mentioned object, and have diligently studied their usefulness. As a result, they have found that a specific epoxy compound having a phosphorus atom in the side chain maintains or improves the original properties of the epoxy resin, imparts flame retardancy, and suppresses toxic gas.

[0006]

It is an object of the present invention to solve the problems associated with the prior art as described above, and it is excellent in flame resistance and heat resistance without impairing the inherent properties of epoxy resin, and in addition to fire. It is an object of the present invention to provide a phosphorus-containing epoxy resin that can suppress the generation of toxic gas at times and a method for producing the same.

[0007]

SUMMARY OF THE INVENTION The phosphorus-containing epoxy resin according to the present invention is
The following general formula (I)

[0008]

[Chemical 2]

(In the formula, n is an integer of 0 to 20. R
₁ and R ₂ are hydrogen, a lower alkyl group or halogen. ) Is indicated by.

The first method for producing a phosphorus-containing epoxy resin according to the present invention is characterized by reacting diphenylphosphinyl hydroquinone with epihalohydrin.

The second method for producing a phosphorus-containing epoxy resin according to the present invention is characterized by reacting diphenylphosphinyl hydroquinone diglycidyl ether with diphenylphosphinyl hydroquinone.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The phosphorus-containing epoxy resin according to the present invention will be specifically described below. The phosphorus-containing epoxy resin according to the present invention is represented by the following formula [I].

[0013]

[Chemical 3]

(In the formula, n is an integer of 0 to 7. R ₁ and R ₂ are hydrogen, a lower alkyl group or halogen.) R ₁ and R ₂ may be the same, and May be different.

However, when R ₁ and R ₂ are lower alkyl groups or halogen, R ₂ is substituted in the meta position when R ₁ is in the meta position, and R ₂ is also substituted in the para position when R ₁ is in the para position. Specific examples of the lower alkyl group include a methyl group, an ethyl group, an n-propyl group and an isopropyl group.

The halogen includes fluorine, chlorine, bromine, iodine and the like. n is 0 to 0 as described above.
20 but preferably 0 to 5, particularly preferably 0 to
It is about 3.

Such a phosphorus-containing epoxy resin has excellent properties inherent in the epoxy resin and is excellent in flame resistance or heat resistance. When the substituents (R ₁ and R ₂ ) are not halogen, it is possible to suppress the generation of toxic gas during a fire.

Next, the method for producing the phosphorus-containing epoxy resin of the present invention will be specifically described. The diphenylphosphinyl hydroquinone represented by the general formula (III) used as a raw material for producing the phosphorus-containing epoxy resin according to the present invention is (Zh.Obshch.Khim.), 42 (11), No. 2415-2.
It can be obtained by reacting diphenylphosphine oxide represented by the general formula (II) with 1,4-benzoquinone by the method described on page 418 (1972).

[0019]

[Chemical 4]

The general formula (I) according to the present invention (where n = 0 to 0)
The phosphorus-containing epoxy resin represented by 7) can be produced by reacting the diphenylphosphinyl hydroquinone represented by the formula (III) obtained above with epihalohydrin.

[0021]

[Chemical 5]

(In the formula, Ph represents a phenyl group) Such a reaction between diphenylphosphinylhydroquinone and epihalohydrin causes an addition reaction and a dehalogenation hydrogen reaction at once in the presence of an alkali.

As the epihalohydrin, specifically,
Epichlorohydrin, epibromhydrin, epiiodohydrin and the like are used, but epichlorohydrin is industrially preferable.

The molecular weight of the resulting epoxy resin is determined by the amount of epihalohydrin used and the reaction conditions. Reactions such as those described above often result in compounds where n = 0-7.

Specific examples of the alkali include sodium hydroxide, potassium hydroxide, calcium hydroxide and potassium carbonate, but sodium hydroxide and potassium hydroxide are usually used.

The amount of alkali is usually 0.8 to 2.0 mol, preferably 1.0 to 1.7 mol, based on 1 equivalent of the phenolic hydroxyl group of diphenylphosphinylhydroquinone represented by the formula (III). Used in.

The reaction temperature is 40 to 130 ° C., preferably 8
It is 0 to 120 ° C. The reaction time is 30 minutes to 3 hours, preferably 90 to 120 minutes. After completion of the reaction, the salt produced as a by-product is removed by filtration or the like, and the excess epihalohydrin is distilled off, or it is dissolved in a suitable solvent and washed with water to remove the salt and the excess alkali. can get.

Further, the phosphorus-containing epoxy resin represented by the general formula (I) (n = 0 in the formula) has the following formula (III):
Diphenylphosphinyl hydroquinone represented by the so-called Williamson method to diallyl ether,
It can be produced by direct epoxidation or by allowing hypochlorous acid to act, and then ring-closing with an alkali to give a diglycidyl ether.

[0029]

[Chemical 6]

In the general formula (I) (wherein Ph represents a phenyl group), the epoxy resin in which n is 2 or more is:
General formula (I) obtained as described above (where n = 0)
It can be produced by reacting the epoxy resin represented by the formula with diphenylphosphinyl hydroquinone represented by the formula (III).

[0031]

[Chemical 7]

(In the formula, Ph represents a phenyl group) In this reaction, the molecular weight of the obtained epoxy resin is changed by changing the molar ratio of the reaction raw materials.

This reaction is an exothermic reaction and both components
When the mixture is melt-mixed at 60 to 230 ° C., preferably 190 to 200 ° C. and the molten mixture is maintained at this temperature, the polyaddition reaction proceeds.

Such a reaction proceeds smoothly without using an inorganic alkali compound such as sodium hydroxide and sodium carbonate, an ammonium compound, a catalyst such as imidazole and triphenylphosphine. Therefore, the catalyst does not remain in the obtained epoxy resin, and the deterioration of physical properties can be avoided.

The end point of the reaction is determined to be stable by measuring the epoxy equivalent of the obtained epoxy resin over time, but the reaction time is generally about 3 to 4 hours. Incidentally, in the conventionally known method for producing an epoxy resin, particularly in the method for producing an epoxy resin by the two-step method, it is indispensable to use a catalyst such as the above-mentioned inorganic alkali compound, ammonium compound, imidazole, triphenylphosphine, and the like. Since it is difficult to remove the catalyst of (3), there is a problem that it remains in the obtained epoxy resin.

The epoxy resin according to the present invention as described above can be cured with a curing agent in the same manner as the conventionally known epoxy resin. As the curing agent, amine compounds, acid anhydrides, phenolic novolacs and derivatives thereof can be used without particular limitation.

Although the curing conditions differ depending on the type of curing agent, the curing temperature is usually from room temperature to 200 ° C., and the curing time is from several minutes to several tens hours. The epoxy resin according to the present invention can be used by blending a filler, a pigment, a plasticizer, a diluent, an extender, a flexibility-imparting agent, another flame resistance-imparting agent and the like.

Such an epoxy resin can be effectively used in fields where flame resistance and flame retardancy are required, such as insulating materials, laminated plates, sealing materials, molding materials and composite materials.

[0039]

EFFECT OF THE INVENTION The epoxy resin according to the present invention has excellent flame resistance and heat resistance without deteriorating the inherent properties of the epoxy resin, and can suppress the generation of toxic gas during a fire.

In addition, since a catalyst such as triphenylphosphine does not have to be used in the production of this epoxy resin, these catalysts are not mixed in the resin and the original characteristics of the epoxy resin are not deteriorated.

Therefore, the epoxy resin using the compound of the present invention can be effectively used in the fields where flame retardancy is required, such as insulating materials, laminated plates, sealing materials, molding materials, and composite materials.

[0042]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0043]

Example 1 Production of Epoxy Resin of General Formula (I) (where n = 0) A reaction vessel equipped with a thermometer, a stirrer and a dropping funnel was charged with 217 g of diphenylphosphinylhydroquinone and 1300 g of epichlorohydrin, After purging with nitrogen, it was heated to 105 ° C. Then, 175 g of 48% aqueous sodium hydroxide solution was added dropwise over 90 minutes.
During that time, the reaction temperature was maintained at 100 to 110 ° C., and the mixture was further stirred at the same temperature for 30 minutes.

After the reaction was completed, the furnace liquid obtained by filtration was concentrated to obtain a light yellow and transparent semi-solid epoxy resin. This was dissolved in 1500 ml of benzene, washed with water, distilled off benzene, and recrystallized from butanol.
White crystals were obtained.

This product had a yield of 204 g and a melting point of 143.0.
The epoxy equivalent was 219 g / eq. The white crystals obtained were analyzed by infrared absorption spectrum, NMR spectrum and elemental analysis, and the following results were obtained.

That is, the infrared absorption spectrum was as shown in FIG. Further, in the NMR spectrum, the ratio of absorption of hydrogen atoms based on the benzene ring was 13:10 (theoretical value 13:10).

The result of elemental analysis was as follows: carbon 68.5%
(Theoretical value 68.2%), hydrogen 5.4% (theoretical value 5.5)
%) And phosphorus 7.6% (theoretical value 7.3%). From these results, the obtained white crystals are diphenylphosphinyl hydroquinone diglycidyl ether (corresponding to the epoxy resin with n = 0 in the general formula (I)).
Was confirmed.

From the results of liquid chromatography analysis, it was confirmed that the white crystals contained diphenylphosphinylhydroquinone diglycidyl ether in a purity of 99.7% or more.

[0049]

Example 2 Production of Epoxy Resin of General Formula (I) (where n = 2) A four-necked flask equipped with a stirrer, a cooling pipe, a nitrogen gas introducing device and a thermometer was obtained in Example 1. Further, 760 g of diphenylphosphinyl hydroquinone diglycidyl ether (epoxy equivalent 219 g / eq) and 279 g of diphenylphosphinyl hydroquinone were charged and heated to 200 ° C. while flowing nitrogen gas to obtain a transparent molten state. The reaction was carried out for 4 hours while maintaining this temperature.

The obtained solid epoxy resin has an epoxy equivalent of 804 g / eq, and n = 2 in the general formula (I).
Was an epoxy resin.

[0051]

Examples 3 to 5 Production of Epoxy Resin Cured Product The phosphorus-containing epoxy resin obtained in Example 1 was added in an amount as shown in Table 1 to an epoxy resin which was a diglycidyl ether of bisphenol A (Epicoat 828: oil. CHEMICAL SHELL Co., Ltd.), and heated and cured using DDM (4,4′-diaminodiphenylmethane) as a curing agent,
An epoxy resin cured product was produced. Curing at 140 ℃ 2
For 2 hours at 200 ° C. Example 6
Then, curing was performed at 140 ° C. for 2 hours.

The obtained epoxy resin cured product was measured for flame resistance by JIS K-6911 (1979) heat resistance A method. The results are shown in Table 1. Note that Table 1 also shows the phosphorus / bromine content (%) in the cured epoxy resin.

[0053]

Example 6 The phosphorus-containing epoxy compound obtained in Example 2 was added to BGE (1,2) as a diluent in an amount as shown in Table 1.
4-Butanediol diglycidyl ether) was added and an epoxy resin cured product was produced in the same manner as in Example 3.

With respect to the obtained epoxy resin cured product, the flame resistance was measured in the same manner as in Example 3. The results are shown in Table 1.

[0055]

[Comparative Examples 1 and 2] Tetrabrom bisphenol A type epoxy resin (YDB-400, Toto Kasei Co., Ltd.) was added to a commercially available bisphenol A type epoxy resin (Epicoat 828) in an amount as shown in Table 1 as a flame retardant. )) Or a non-reactive triphenylphosphine oxide was mixed and DDM was used as a curing agent in the same manner as in Example 3 to produce a cured epoxy resin.

The heat resistance of the obtained cured epoxy resin was measured in the same manner as in Example 3. The results are shown in Table 1.

[0057]

Comparative Example 3 An epoxy resin cured product was produced in the same manner as in Example 3 without adding a flame retardant to a commercially available bisphenol A type epoxy resin (Epicoat 828).

The heat resistance of the obtained epoxy resin cured product was measured in the same manner as in Example 3. The results are shown in Table 1.

[0059]

[Table 1]

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum of an epoxy resin according to the present invention (represented by general formula (I), where n = 0).

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[Procedure amendment]

[Submission date] September 2, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

It is an object of the present invention to solve the problems associated with the prior art as described above, and it is excellent in flame resistance and heat resistance without impairing the inherent properties of epoxy resin, and in addition to fire. and its object is to provide a possible phosphorus-containing epoxy resin and a manufacturing method thereof, as is to occasionally reduce the occurrence of toxic gases.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

(In the formula, n is an integer of 0 to 7. R ₁
And R ₂ is hydrogen, a lower alkyl group or halogen. ) Is indicated by.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The halogen includes fluorine, chlorine, bromine, iodine and the like. n is 0 to 0 as described above.
7 , preferably 0-5, particularly preferably 0-3
It is a degree.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Next, the method for producing the phosphorus-containing epoxy resin of the present invention will be specifically described. The diphenylphosphinylhydroquinone represented by the general formula (III) used as a raw material for producing the phosphorus-containing epoxy resin according to the present invention is ( 2 h.Obshch.Khim.), 42 (11), No. 2415-2.
It can be obtained by reacting diphenylphosphine oxide represented by the general formula (II) with 1,4-benzoquinone by the method described on page 418 (1972).

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

[0044] After completion of the reaction, was concentrated filtration liquid obtained was filtered to give a clear semi-solid epoxy resin as a pale yellow. This was dissolved in 1500 ml of benzene, washed with water, distilled off benzene, and recrystallized from butanol.
White crystals were obtained.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0059

[Correction method] Change

[Correction content]

[0059]

[Table 1]

[Procedure amendment]

[Submission date] September 4, 1991

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Next, the method for producing the phosphorus-containing epoxy resin of the present invention will be specifically described. The diphenylphosphinylhydroquinone represented by the general formula (III) used as a raw material when producing the phosphorus-containing epoxy resin according to the present invention is ( Z h. Obshch. Khim.), 42 (11), No. 2415-2.
It can be obtained by reacting diphenylphosphine oxide represented by the general formula (II) with 1,4-benzoquinone by the method described on page 418 (1972).

Claims (3)

[Claims] 1. A general formula: (In the formula, n is an integer of 0 to 7. Also, R ₁ and R ₂
Is hydrogen, a lower alkyl group or halogen. ) Phosphorus-containing epoxy resin represented by. 2. A method for producing a phosphorus-containing epoxy resin, which comprises reacting diphenylphosphinyl hydroquinone with epihalohydrin. 3. A method for producing a phosphorus-containing epoxy resin, which comprises reacting diphenylphosphinyl hydroquinone diglycidyl ether with diphenylphosphinyl hydroquinone.