JP2001302686A - New organophosphorus compound, method of producing the same, and epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new organophosphorus compound, and to provide an epoxy resin composition capable of exhibiting excellent flame resistance, without deteriorating heat resistance of a cured product which is obtained by using the compound as a non-halogen-based curing agent and flame retardant for an epoxy resin. SOLUTION: This new organophosphorus compound is expressed by the formula (1) (R1 and R2 are each H or a 1-9C alkyl; and Ar is a benzene ring, a naphthalene ring or an anthracene ring, of which the all have three or more hydroxyl groups) or by the formula (3) (any one among R3, and R5 to R8 is hydroxyl, and the others are each H or a 1-9C alkyl). The epoxy resin composition contains the organophosphorus compound and the epoxy resin as essential ingredients.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel organophosphorus compound useful as a flame retardant and a curing agent for an epoxy resin, and an epoxy resin composition particularly effective as a varnish for electric laminates.

[0002]

2. Description of the Related Art Organophosphorus compounds have recently been widely used as flame retardants for thermoplastic resins and thermosetting resins. In particular, they have high flame retardancy in electrical and electronic material parts such as glass epoxy laminates and IC encapsulants. (UL: V-0) is required,
From the viewpoint of environmental problems, a technique to replace the flame retardant prescription with a halogen is required, and various techniques for using a phosphate ester compound as an organic phosphorus compound as an additive flame retardant have been studied. However, when a phosphate ester-based compound is used as an additive-based flame retardant, hydrolysis and bleed-out to the resin surface are liable to occur, and there is a problem that the characteristics of a molded product are deteriorated. Therefore, for example, Japanese Patent Application Laid-Open
Japanese Patent Publication No. 11662 discloses a technique in which a bisphenol-type epoxy resin is modified with a specific phosphorus compound to improve the heat resistance and the like of a molded article.
No. 8 discloses a technique in which an epoxy resin containing 20% by weight or more of a novolak epoxy resin is reacted with an organic phosphorus compound.

[0003]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No.
In the technology described in JP-A-16662 and JP-A-11-279258, since the phosphorus compound is used as a modifying component of the epoxy resin as the main component, there is a limitation on the phosphorus content contained in the composition, As a non-halogen flame retardant formulation, it does not exhibit sufficient flame retardant effect,
Further, when the amount of modification of the phosphorus compound is increased to enhance the flame retardant effect, the epoxy equivalent is increased, and the heat resistance of the cured product is significantly reduced.

An object of the present invention is to provide an epoxy resin composition which exhibits excellent flame retardancy without lowering the heat resistance of the cured product as a flame retardant prescription for a non-halogen epoxy resin cured product. And a novel phosphorus compound used for the same.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a phosphorus compound having a specific structure having a phenolic hydroxyl group having three or more functional groups in the molecular structure is used as a curing agent for an epoxy resin. As a result, the present inventors have found that the heat resistance and the flame-retardant effect of a cured product can be achieved by using the compound, and the present invention has been completed.

[0006]

DETAILED DESCRIPTION OF THE INVENTION That is, the present invention relates to the following general formula 1

[0007]

Embedded image (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
The alkyl group 9 and Ar each represent a benzene ring, a naphthalene ring or an anthracene ring having three or more hydroxyl groups. ), An epoxy resin (A) represented by the following general formula 1

[0008]

Embedded image (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
The alkyl group 9 and Ar each represent a benzene ring, a naphthalene ring or an anthracene ring having three or more hydroxyl groups. The present invention relates to an epoxy resin composition comprising the novel organic phosphorus compound (B) represented by the formula (1) as an essential component.

The novel phosphorus compound of the present invention has the following general formula 1

Embedded image (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
The alkyl group 9 and Ar each represent a benzene ring, a naphthalene ring or an anthracene ring having three or more hydroxyl groups. In the present invention, when used as a curing agent for an epoxy resin, an excellent flame retardant effect and heat resistance of a cured product can be exhibited. Among those having such a structure, in particular, further improvement of the flame retardant effect can be realized, and in varnish applications for electric laminates, the crystallinity of the curing agent itself can be reduced, and the practicality is enhanced. , The following general formula 2:

Embedded image (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
Any three of the 9 alkyl groups and R3 to R9 are hydroxyl groups, and the others represent a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, respectively. )) Are preferred. Further, from the viewpoint of excellent heat resistance and flame retardant effect and easy production thereof, the following general formula 3

Embedded image (In the formula, one of R3, R5, R6, R7, and R8 is a hydroxyl group, and the other is a hydrogen atom or a group having 1 to 1 carbon atoms.
9 represents an alkyl group. )) Are preferred.

The method for producing the novel phosphorus compound is not particularly limited.

Embedded image And a method of reacting a compound represented by the following formula with a hydroquinone, naphthoquinone, anthraquinone or the like optionally substituted with a hydroxyl group.

In the case of a novel phosphorus compound using naphthoquinone as a raw material, which has remarkably good flame retardancy, as a finally obtained novel phosphorus compound, the following method is mentioned as a specific production method.

That is, an organic solvent and a phosphorus compound represented by the general formula 4 are charged into a reactor having a stirrer, a reflux condenser, a thermometer, and a raw material inlet, and the temperature is maintained at room temperature to 100 ° C., preferably 40 to 80 ° C. Dissolve the phosphorus compound. After dissolution, general formula 5

Embedded image (In the formula, one of R3, R5, R6, R7, and R8 is a hydroxyl group, and the other is a hydrogen atom or a group having 1 to 1 carbon atoms.
9 represents an alkyl group. ) Is added little by little over 1 to 5 hours,
After the addition, the reaction is completed at 100 to 130 ° C for 1 to 5 hours.

Here, as the compound represented by the general formula 4, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is preferable.
Are 2-hydroxy-1,4 naphthoquinone, 5-hydroxy-1,4-naphthoquinone, 2
-Hydroxy-3-methyl-1,4-naphthoquinone, 5
-Hydroxy-2-methyl-1,4-naphthoquinone and the like, among which 2-hydroxy-1,4-naphthoquinone and 5-hydroxy-1,4-naphthoquinone are preferable.

Next, the composition of the present invention uses the above-mentioned novel phosphorus compound as a curing agent for an epoxy resin, that is, a composition containing an epoxy resin (A) and the above-mentioned novel phosphorus compound (B) as essential components. It is. In particular, when the compound represented by the above general formula 3 is used as the novel phosphorus compound (B), it is excellent in electric laminates without causing crystallization of the curing agent when varnished with an organic solvent. It is preferable because a fuel effect can be exhibited.

The epoxy resin (A) used here is not particularly limited, but specific examples thereof include novolak type epoxy resins such as phenol novolak type epoxy resin and cresol novolak type epoxy resin, and bisphenol A type. Bisphenol type epoxy resins such as epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, tetramethyl bisphenol A type epoxy resin, bisphenol S type epoxy resin, resorcinol diglycidyl ether, diglycidyl ether of 1,6-dihydroxynaphthalene Bifunctional epoxy resin such as dimethyl bisphenol C diglycidyl ether, 1,6-diglycidyloxynaphthalene type epoxy resin, 1- (2,7-diglycidyloxynaphthyl) -1- ( Naphthalene-based epoxies such as -glycidyloxynaphthyl) methane, 1,1-bis (2,7-diglycidyloxynaphthyl) methane, 1,1-bis (2,7-diglycidyloxynaphthyl) -1-phenyl-methane Resin, glycidyl ester type epoxy resins such as diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl p-oxybenzoic acid and glycidyl dimer, diglycidyl aniline, diglycidyl toluidine, etc. And glycidylamine-type epoxy resins, diglycidylhydantoins, and hydantoin-type epoxy resins such as glycidylglycidoxyalkylhydantoin.

The use of these epoxy resins (A) is not limited to one type, and two or more types can be used in combination. Along with each of the epoxy resins (A), some of the following compounds, namely, n-butyl glycidyl ether, allyl glycidyl ether, 2-
Ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, P.I. Monofunctional epoxy compounds such as Sec-butylphenyl glycidyl ether, glycidyl methacrylate, vinylcyclohexene monoepoxide, etc. may be used.

Of these, novolak type epoxy resins and naphthalene type epoxy resins are preferred from the viewpoint of good heat resistance particularly for electric laminates.

Further, in these epoxy resins (A), from the viewpoint of adhesion and heat resistance in electric laminates,
The epoxy equivalent is preferably in the range of 100 to 500 g / eq.

Next, as a component of the composition of the present invention,
In addition to the novel phosphorus compound (B), other epoxy resin curing agents may be used in combination. For example, latent amine curing agents such as dicyandiamide, imidazole, BF3-amine complex and guanidine derivatives, metaphenylenediamine Aromatic amines such as diaminodiphenylmethane, diaminodiphenylsulfone, cyclophosphazene oligomers, compounds having phenols and triazine rings, or compounds containing nitrogen atoms such as mixtures or condensates of phenols and triazine rings and aldehydes, phenol novolaks Resin, cresol novolak resin, bisphenol A novolak resin, polyamide resin, maleic anhydride, phthalic anhydride, hexahydrophthalic anhydride,
An acid anhydride curing agent such as pyromellitic anhydride may be used. These curing agents may be used alone or in combination of two or more.

Among these, a curing agent containing a nitrogen atom typified by dicyandiamide, a mixture or a condensate of phenols, a triazine ring and an aldehyde is particularly preferred in that the adhesion and the inevitable effect are synergistically improved. preferable.

In the present invention, a curing accelerator can be used in combination, and examples thereof include tertiary amines such as benzyldimethylamine, imidazole, metal salts of organic acids, Lewis acids, and amine complex salts. These can be used alone or in combination of two or more.

The composition of the present invention can be used in an electric laminate to prepare a varnish for an electric laminate by using an organic solvent (C) as an essential component in addition to the above-mentioned components. Can be. Here, the organic solvent that can be used is not particularly limited, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropyl alcohol, n-butanol, methoxypropanol, methyl cellosolve, ethyl carbitol, Ethyl acetate, xylene, toluene, cyclohexanol, N, N-dimethylformamide and the like can be mentioned, and these solvents can be used as a mixed solvent of two or more as appropriate.

The amount of the organic solvent to be used is not particularly limited, but particularly for an electric laminate, in the range of 20 to 80% by weight in terms of solid content from the viewpoint of impregnation into glass cloth. Preferably, there is.

The epoxy resin composition of the present invention may further contain various additives, flame retardants, fillers, and the like, if necessary.

Although the epoxy resin composition of the present invention is extremely useful for electric laminates, it can be used in various applications such as adhesives, castings and paints by combining with a curing agent.

The method for producing a laminate from the above-described epoxy resin composition of the present invention is not particularly limited, and it can be produced by a known and commonly used method. A method of impregnating the resin composition at a ratio of a resin amount of 30 to 70% by weight to form a prepreg, and then heating and pressing 1 to 10 of the prepregs to obtain a prepreg is used.

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

[Production of New Phosphorus Compound] Example 1 To 100 parts of ethylene glycol monoethyl ether, 9
54 parts (0.25 mol) of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are added and completely dissolved at 70 ° C. 2-hydroxy-1,4
-42 parts (0.24 mol) of naphthoquinone was added little by little over 2 hours, and after the addition, the mixture was held at 120 ° C for 5 hours to complete the reaction. Thereafter, ethylene glycol monoethyl ether was recovered under reduced pressure to remove the solvent to obtain a crystal,
Further, the product was washed with methanol and dried under reduced pressure to obtain a white crystalline powder product. The yield was 92%. As a result of electrolytic desorption mass spectrometry of this product, it was confirmed that the molecular weight of the product was 390. Table 1 shows the elemental analysis values of the product.
As shown in FIG.

Example 2 9,10-Dihydro-9-oxa-oxide was added to 100 parts of toluene.
10-phosphaphenanthrene-10-oxide 43
(0.20 mol) and completely dissolved at 70 ° C.
33 parts of 2-hydroxy-1,4-naphthoquinone (0.1
9 mol) in small portions over 2 hours.
C. for 5 hours to complete the reaction. Thereafter, when the reaction solution was cooled, a crystalline product was precipitated. The product was recovered by suction filtration, washed with methanol, and dried under reduced pressure to obtain a white crystalline powder product. The yield was 86%. The product was subjected to electrolytic desorption mass spectrometry.
It was confirmed that the molecular weight of the product was 390, and the elemental analysis values were as shown in Table 1.

[0029]

[Table 1]

FIG. 1 shows the infrared absorption spectrum (KBr tablet method) of the compound obtained in Example 1.

[Synthesis of Comparative Phosphorus Compound Modified Epoxy Resin] Comparative Example 1 9,10-dihydro-9-oxa-
10-phosphaphenanthrene-10-oxide 54
Then, the mixture was heated to 70 ° C. with stirring and completely dissolved, and then a phenol novolak type epoxy resin having an epoxy equivalent of 188 (EPICLON N-77).
0: 267 parts of Dainippon Ink and Chemicals, Inc. was added and dissolved, and then 36 parts of 1,4, naphthoquinone (0.
23 mol) was added in small portions over 2 hours. After completion of the addition, the mixture was kept at 125 ° C. for 2 hours, cooled to 50 ° C., added with 0.06 part of triphenylphosphine, and added at 160 ° C.
After reacting for an hour, xylene was removed from the solvent to obtain a target resin having a phosphorus content of 2.0% by weight and an epoxy equivalent of 380. Hereinafter, this is abbreviated as resin (P-1).

[Evaluation in Electric Laminate Application] Example 3 The novel organic phosphorus compound obtained in Example 1 was previously charged with methyl cellosolve and dimethylformamide in an amount of 1.0 equivalent to the epoxy group of the epoxy resin as the main component. And a phenol novolak type epoxy resin having an epoxy equivalent of 188 (EPICLON N-770-70M,
144 parts of Dainippon Ink and Chemicals, Inc.) and a curing accelerator, 2 ethyl 4-methyl imidazole, were added to prepare a mixed solution (varnish) having a nonvolatile content (NV) of 60%.
Further, the amount of the curing accelerator is such that the gel time of the prepreg is 170.
The temperature was set at a rate of 120 seconds at 120C. Thereafter, using this mixed solution, glass cloth WEA 7628 as a base material was used.
H258N (manufactured by Nittobo Co., Ltd.) at 160 ° C.
And dried to obtain a prepreg having a resin content of 40%. Next, eight sheets of the obtained prepregs were superposed, and a pressure of 3.
It was cured under the conditions of 9 MN / m 2, a heating temperature of 170 ° C. and a heating time of 120 minutes to produce a laminate. The peel strength, delamination strength, flame retardancy, T
g (glass transition temperature), PCT water absorption, and solder resistance were tested. Table 2 shows the results. In addition, each test followed the following method. [Peel strength] Based on JIS-K6481. [Interlayer peel strength] Based on JIS-K6481. [Flame retardancy] Compliant with UL standard [Tg (glass transition temperature)] Measured by DMA method. Heating rate 3 ° C / min [Water absorption: 1 in PCT (pressure cooker test)]
Weight change before and after treatment at 21 ° C / 100% humidity (wt
%) As a water absorption ratio] [Solder resistance;
The sample was immersed in a solder bath at 0 ° C. for 30 seconds and the change in the state was observed.] Judgment criteria: ：: no change in appearance;
×: Swelling occurred

Example 4 Example 3 was repeated except that a cresol novolak type epoxy resin having an epoxy equivalent of 216 (EPICLON N-690-75M: manufactured by Dainippon Ink and Chemicals, Inc.) was used.
A varnish and a laminate were prepared in the same manner as in the above, and evaluated.
Table 2 shows the results.

Example 5 A naphthalene type epoxy resin having an epoxy equivalent of 156 (E
A varnish and a laminate were prepared and evaluated in the same manner as in Examples 3 and 4, except that PICLON HP-4032-70M: manufactured by Dainippon Ink and Chemicals, Inc. was used. Table 2 shows the results.

Example 6 An aminotriazine novolak resin containing the novel organophosphorus compound obtained in Example 1 in an amount of 0.5 equivalent to the epoxy group of the epoxy resin as a main component and a nitrogen content of 13% having a phenol skeleton and a triazine skeleton. (Phenolite KA-705
4, Dainippon Ink and Chemicals, Inc.) is dissolved in methyl cellosolve and dimethylformamide in advance so as to be 0.5 equivalent to the epoxy group of the epoxy resin of the base resin, and a phenol novolak type epoxy resin having an epoxy equivalent of 188 is used. (EPICLON N-770-70M,
A varnish and a laminate were prepared and evaluated in the same manner as in Examples 3 and 4, except that 144 parts of Dainippon Ink and Chemicals, Inc. were used. Table 2 shows the results.

Comparative Example 2 The resin (P-1) obtained in Comparative Example 1 was dissolved in methyl ethyl ketone, and then a curing agent dicyandiamide and a curing accelerator 2 ethyl 4-methyl imidazole previously dissolved in methyl cellosolve and dimethylformamide. And a mixed solution (varnish) with a non-volatile content (NV) of 55%
Was prepared. At this time, the amount of the curing agent is set so that the active hydrogen equivalent becomes 0.5 equivalent to the epoxy group in the epoxy resin, and the amount of the curing accelerator is set to 120 seconds at a gel time of the prepreg of 170 ° C. To a certain percentage. Thereafter, a laminate was prepared and evaluated in the same manner as in Example 3. Table 2 shows the results.

[0037]

[Table 2]

[0038]

According to the present invention, as a flame-retardant prescription of a non-halogen epoxy resin cured product, an epoxy resin composition exhibiting excellent flame retardancy without lowering the heat resistance of the cured product, and A novel phosphorus compound used for this can be provided. The composition of the present invention is particularly useful as a varnish for an electric laminate, and when the compound represented by the general formula 3 is used as a curing agent, crystallization of the curing agent in the varnish can be favorably suppressed.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the compound obtained in Example 1.

Claims (9)

[Claims] [Claim 1] The following general formula 1 (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
The alkyl group 9 and Ar each represent a benzene ring, a naphthalene ring or an anthracene ring having three or more hydroxyl groups. The novel organic phosphorus compound represented by). 2. The following general formula 2: (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
9 alkyl groups and any three of R3 to R9 are hydroxyl groups, and the others represent a hydrogen atom or an alkyl group having 1 to 1 carbon atoms, respectively. The novel organic phosphorus compound represented by). 3. The following general formula 3: (In the formula, one of R3, R5, R6, R7, and R8 is a hydroxyl group, and the other is a hydrogen atom or a group having 1 to 1 carbon atoms.
9 represents an alkyl group. The novel organic phosphorus compound represented by). 4. An epoxy resin (A) and the following general formula 1 (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
The alkyl group 9 and Ar each represent a benzene ring, a naphthalene ring or an anthracene ring having three or more hydroxyl groups. An epoxy resin composition comprising the novel organic phosphorus compound (B) represented by the formula (1) as an essential component. 5. An epoxy resin (A) and the following general formula 2: (Wherein, R1 and R2 represent a hydrogen atom or a carbon atom having 1 to 1
9 alkyl groups and any three of R3 to R9 represent a hydroxyl group, and the others represent a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, respectively. The organic phosphorus compound (B) represented by
An epoxy resin composition characterized by comprising as an essential component. 6. The composition according to claim 4, wherein the epoxy resin (A) is a novolak epoxy resin or a naphthalene epoxy resin. 7. An epoxy resin (A) having an epoxy equivalent of 1
7. The composition according to claim 4, wherein the amount is from 00 to 500 g / eq.
A composition as described. 8. The method according to claim 4, further comprising an organic solvent (C) in addition to the components (A) and (B).
A composition according to any one of the preceding claims. 9. The composition according to claim 8, wherein the proportion of the organic solvent (C) used is from 20 to 80% by weight of the solid content.