JPH10152545A - Method for producing phosphorus atom-containing epoxy resin, flame-retardant epoxy resin composition and electric laminate - Google Patents

Abstract

(57) [Problem] To provide a flame-retardant epoxy resin composition and an electric laminate excellent in heat resistance and flame retardancy. SOLUTION: A phosphorus atom-containing epoxy resin obtained by reacting a bisphenol A type epoxy resin with monobutyl phosphate in the presence of a compound having a functional group reactive with an epoxy group such as diethanolamine is used as a main component. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a phosphorus atom-containing epoxy resin, a flame-retardant epoxy resin composition, and an electric laminate. That is, excellent flame retardancy and heat resistance,
A method for easily producing a phosphorus atom-containing epoxy resin, a flame-retardant epoxy resin composition useful for various uses such as a sealing material, a laminate, and a paint because of its excellent flame retardancy and heat resistance of a cured product, and The present invention relates to an electric laminate having good laminate properties and capable of non-halogenation.

[0002]

2. Description of the Related Art Epoxy resins have been widely used mainly for electric and electronic material parts because of their excellent adhesion and electrical properties (insulating properties).

[0003] These electric and electronic material parts are required to have high flame retardancy as typified by a glass epoxy laminate and an IC sealing material, but a halogenated epoxy resin is usually used. For example, in a glass epoxy laminate, as a flame-retardant FR-4 grade, an epoxy resin generally substituted with bromine as a main raw material component, and an epoxy resin obtained by mixing various epoxy resins with the epoxy resin, and a curing agent for the epoxy resin. Agents are used.

However, in recent years, toxicity of organic halogen substances represented by dioxin has become a serious problem, and halogen dissociation at high temperature in IC packages has a bad influence on long-term electrical reliability. There is a strong need for flame retardants or other flame retardant formulations that reduce the amount or use other compounds that can replace halogens.

[0005] As an alternative to such a flame retardant prescription using a halogen, for example, a method of adding a flame retardant such as a phosphorus compound is known, and JP-A-63-3016 discloses a phosphate ester. And the use of a reaction product of brominated epoxy resin.

[0006]

However, in the method of adding a phosphorus compound as a flame retardant, the flame retardant effect is good, but the crosslinking density is lowered and the heat resistance is extremely lowered due to the plasticizing effect of the phosphorus compound. And was inferior in basic characteristics such as inviting.

On the other hand, the technique of using a reaction product of a phosphoric ester and a brominated epoxy resin as a main component described in Japanese Patent Application Laid-Open No. 63-3016 discloses a technique for increasing the molecular weight of a polymer to induce side reactions such as polymerization of the epoxy resin. It is difficult to obtain a stable and easy compound, and the obtained cured product has poor strength and heat resistance.

The problem to be solved by the present invention is to produce a phosphorus atom-containing epoxy resin having excellent flame retardancy without deteriorating the basic properties of the epoxy resin cured product such as heat resistance. An object of the present invention is to provide a flame-retardant epoxy resin composition having excellent flame retardancy and an electric laminate.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present invention can react with epoxy resin when reacting (A) epoxy resin with (B) phosphoric acid and phosphate ester. (C) having a functional group
By using together, it is possible to arbitrarily adjust the stable epoxy equivalent by suppressing the side reaction, and by using itself as the main agent of the epoxy resin composition, excellent flame retardant effect without deteriorating the cured product characteristics Have been found, and can be replaced with the conventional halogen-based flame retardant formulation, and the present invention has been completed.

That is, the present invention provides an epoxy resin (A)
A method for producing a phosphorus atom-containing epoxy resin, which comprises reacting phosphoric acid or a phosphoric acid ester (B) with a compound (C) having a functional group reactive with an epoxy group, and an epoxy equivalent of 150 to 1000 g / eq. A phosphorus-containing epoxy resin having a phosphorus atom-containing epoxy resin and a curing agent as essential components, a phosphorus-containing epoxy resin having an epoxy equivalent of 150 to 1000 g / eq, a curing agent, and an organic compound. The present invention relates to an electric laminate obtained by press-molding a plurality of prepregs containing a varnish containing a solvent as an essential component.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The production method of the present invention comprises reacting the above components (A), (B) and (C). Normally, the epoxy resin (A) and the phosphoric acid or the phosphoric acid ester (B) start the reaction rapidly at room temperature without a catalyst simply by mixing. This is presumably because phosphoric acid has high reactivity and self-polymerization of epoxy groups is induced. There is a method in which the reaction is carried out in a solvent, but self-polymerization of the epoxy inevitably occurs and it is difficult to control the reaction. In the present invention, in the reaction between the component (A) and the component (B), by using a compound (C) having a functional group that reacts with an epoxy group, self-polymerization of the epoxy resin can be suppressed, and the compound can be stably formed. It is characterized in that a phosphorus atom-containing epoxy resin can be produced.

The epoxy resin (A) used in the production method of the present invention is not particularly limited.
A halogen atom-free epoxy resin is preferred as a flame-retardant formulation that replaces the halogen-based flame-retardant formulation.

Here, the halogen-free epoxy resin means that the raw material before reacting with epichlorohydrin contains no halogen or is not modified with a halogenated compound. That is, since an epoxy resin is usually synthesized by reacting epichlorohydrin, a very small amount of chlorine remains in the synthesized epoxy resin. Therefore, such a small amount of chlorine may be mixed into the halogen-free epoxy resin in the present invention. In this case, it is naturally preferable to reduce such impurity chlorine components.

As such an epoxy resin (A),
For example, n-butyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, P.I. Monofunctional epoxy resins such as Sec-butylphenyl glycidyl ether, glycidyl methacrylate, and vinylcyclohexene monoepoxide;

Bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, tetramethyl bisphenol A type epoxy resin and bisphenol S type epoxy resin;

Resorcinol diglycidyl ether, 1
-6 diglycidyl ether of dihydroxynaphthalene,
Other bifunctional epoxy resins such as dimethyl bisphenol C diglycidyl ether,

1,6-diglycidyloxynaphthalene type epoxy resin, 1- (2,7-diglycidyloxynaphthyl) -1- (2-glycidyloxynaphthyl) methane, 1,1-bis (2,7-di Naphthalene epoxy resins such as glycidyloxynaphthyl) methane and 1,1-bis (2,7-diglycidyloxynaphthyl) -1-phenyl-methane;

Phenol novolak epoxy resin, orthocresol novolak epoxy resin, bisphenol A novolak epoxy resin, bisphenol AD
Novolak type epoxy resin such as novolak resin,

Cycloaliphatic epoxy resins such as epoxy resins having a cyclohexene oxide group, epoxy resins having a tricyclodecene oxide group, epoxy resins having a cyclopentene oxide group, and epoxidized dicyclopentadiene;

Glycidyl ester type epoxy resins such as diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl p-oxybenzoic acid, glycidyl dimer acid and triglycidyl ester;

Glycidylamine type epoxy such as diglycidylaniline, tetraglycidylaminodiphenylmethane, triglycidyl p-aminophenol, triglycidyl-p-aminophenol, tetraglycidylmethaxylylenediamine, diglycidyltoluidine, tetraglycidylbisaminomethylcyclohexane, etc. resin,

Hydantoin type epoxy resins such as diglycidylhydantoin and glycidylglycidoxyalkylhydantoin; heterocyclic epoxy resins such as triallyl isocyanurate and triglycidyl isocyanurate;

Phloroglysinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerin triglycidyl ether, 2- [4-
(2,3-epoxypropoxy) phenyl] -2- [4
-[1,1-bis [4- (2,3-epoxypropoxy) phenyl] ethyl] phenyl] propane, 1,3-
Bis [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1- [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1-methylethyl] phenyl] Trifunctional epoxy resins such as ethyl] phenoxy] -2-propanol,

Tetrahydroxyphenylethanetetraglycidyl ether, tetraglycidylbenzophenone,
Examples thereof include tetrafunctional epoxy resins such as bisresorcinol tetraglycidyl ether and tetraglycidoxybiphenyl.

The use of these epoxy resins (A) is not limited to one type, and two or more types can be used in combination.

Of these, amine type epoxy resins are particularly preferred in that flame retardancy is easily obtained due to a synergistic effect with phosphorus, and bisphenol type resins are preferable in terms of a good balance between heat resistance and impregnation. Epoxy resins are preferred. Among the bisphenol type epoxy resins, bisphenol A type epoxy resin and bisphenol F type epoxy resin are particularly preferable.

The epoxy resin (A) described in detail above has an epoxy equivalent of 10 from the viewpoint that the epoxy equivalent of the phosphorus atom-containing epoxy resin finally obtained can be within an appropriate range described later.
It is preferably from 0 to 500 g / eq.

The phosphoric acid or phosphoric ester (B) is not particularly limited as long as it has a hydroxyl group capable of reacting with an epoxy group.
As with the epoxy resin (A), those containing no halogen atom are preferable. For example, phosphoric acid, hypophosphorous acid, phosphorous acid, hypophosphoric acid, pyrophosphoric acid, orthophosphoric acid, sodium phosphate, sodium phosphite, Sodium pyrophosphate, sodium acid pyrophosphate, sodium acid metaphosphate, methyl acid phosphate, isopropyl acid phosphate, ethyl acid phosphate, butyl acid phosphate,
Butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate,
Ethylene glycol acid phosphate, dibutyl phosphate, diisodecyl phosphate, diisostearyl phosphate, monobutyl phosphate, butyl pyrophosphate, 2-ethylhexyl acid phosphate, di-2-ethylhexyl phosphate, isodecyl acid phosphate, monoisodecyl phosphate, mono-2 -Ethylhexyl 2-ethylhexylphosphonate, mono (2-acryloyloxyethyl) acid phosphate, mono (2-methacryloyloxyethyl) acid phosphate, 2-methacryloyloxyethyl acid phosphate, (2-hydroxyethyl) methacrylate acid phosphate, dibenzyl phosphate Octylphosphinic acid, ethylphosphonic acid, phenylphosphine Phosphate, 2-aminoethyl phosphonic acid, other monoalkyl phosphates, dialkyl phosphates, aromatic phosphates, hydroxy - ethane - diphosphonic acids, nitrilo - tris - methylene -
Phosphonic acids, pentaerythritol diphosphate,
Examples include various phosphoric acid polycondensates.

Of these, monoalkyl phosphates are particularly excellent in solvent solubility and good in workability.
Higher molecular weight of the finally obtained epoxy resin can be suppressed, and strength and flexibility are improved, which is preferable.

Next, the compound (C) having a functional group capable of reacting with the epoxy resin is not particularly limited, and examples thereof include aliphatic amines, aromatic amines and polyamines having an amino group in the structure. , Modified amines, polyamide resins, polyamide adducts, dicyandiamide and its derivatives, organic acid hydrazide, diaminomaleonitrile, derivatives thereof with melamine, amine imides, various amines such as amino resins, acid anhydrides, and organic acids having a carboxyl group , Polysulfide resins, mercaptans,
Polymercaptans, imidazoles, protonic acids,
Examples include phenolic resins, phenols, novolak resins such as substituted phenols, polyvinylphenols, alcohols, alkanolamines, and the like.

In the present invention, the epoxy resin (A)
And a phosphoric acid or a phosphoric acid ester (B), and a compound (C) having a functional group reactive with an epoxy group, whereby the epoxy resin does not have a high molecular weight and has excellent cured product performance. A phosphorus atom-containing epoxy resin can be obtained. Specifically, the epoxy equivalent of the target epoxy resin is 150 to 1000 g / eq. The phosphorus-containing epoxy resin thus obtained is an epoxy resin used as an essential component in the composition and the electric laminate of the present invention. The target epoxy equivalent is particularly preferably 150 to 800 from the viewpoint of heat resistance and impregnation.

The reaction method of the epoxy resin (A), phosphoric acid or phosphoric ester (B), and the compound (C) having a functional group reactive with the epoxy group is as follows. When three-dimensional cross-linking occurs, there is a possibility of gelling due to high molecular weight. Therefore, it is preferable to appropriately select the amount of the compound (C) to be used.

Therefore, the reaction ratio of each epoxy resin (A), phosphoric acid or phosphoric ester (B), and compound (C) having a functional group reactive with an epoxy group can be accurately determined depending on the average number of functional groups. (A)
The range in which the hydroxyl group and the ester group in (B) are 0.1 to 0.8 equivalent and the functional group in the component (C) is 0.01 to 0.5 equivalent to 1 equivalent of the epoxy group in the component. Is mentioned. In the sense of preventing the gelation, the hydroxyl group and the ester group in the component (B) are 0.1 to 0.7 equivalent, and the functional group in the component (C) is 1 equivalent to 1 equivalent of the epoxy group in the component (A). Is more preferably in the range of 0.01 to 0.3 equivalent.

The reaction conditions are not particularly limited as long as a necessary and sufficient grafting ratio can be obtained and gelation does not occur. The reaction may be carried out at a temperature of ° C.

Although the reaction may proceed without a catalyst,
A catalyst can be used. Examples of usable catalysts include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, tertiary amines such as triethylamine and benzyldimethylamine, quaternary ammonium salts such as tetramethylammonium chloride, imidazole compounds and the like. Is mentioned.

In the production method of the present invention, the reaction may be carried out in the presence of an organic solvent, if necessary. The use of an organic solvent is a useful method in controlling the reaction. However, alcohol-based solvents may react with the epoxy resin in some cases, so it is necessary to pay attention to this point.
The solvent that can be used is not particularly limited, for example,
Examples include acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropyl alcohol, n-butanol, methoxypropanol, methyl cellosolve, ethyl carbitol, ethyl acetate, xylene, toluene, cyclohexanol, and N, N-dimethylformamide.

The phosphorus atom-containing epoxy resin thus obtained has a phosphorus content of 1 to 10% from the viewpoint of flame retardancy.
It is preferred that

Next, the flame-retardant epoxy resin composition of the present invention contains a phosphorus atom-containing epoxy resin composition having an epoxy equivalent of 150 to 1000 g / eq and a curing agent as essential components, and was obtained by the above-mentioned production method. The phosphorus atom-containing epoxy resin can be used as a main ingredient as it is.

Here, as described above, the phosphorus atom-containing epoxy resin used is preferably obtained by the production method of the present invention, and is therefore preferably a halogen atom-free epoxy resin.

Next, as the curing agent used here,
There is no particular limitation, and any of the general curing agents for epoxy resins can be used.For example, latent amine curing agents such as dicyandiamide, imidazole, BF3-amine complex, and guanidine derivatives, metaphenylenediamine, diamino Aromatic amines such as diphenylmethane and diaminodiphenyl sulfone, and other curing agents containing a nitrogen atom such as cyclophosphazene oligomers,

A compound having a phenol and a triazine ring, or a mixture or condensate of a phenol, a triazine ring and an aldehyde,

In addition, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, polyamide resin, maleic anhydride, phthalic anhydride,
Acid anhydride-based curing agents such as hexahydrophthalic anhydride and pyromellitic anhydride can be used. These curing agents may be used alone or in combination of two or more.

Among these, an effect agent containing a nitrogen atom, and a mixture or a condensate of a phenol, a triazine ring and an aldehyde are particularly preferred in that the inevitable effect is synergistically improved.

As the curing accelerator, any known and commonly used curing accelerators can be used. Examples thereof include tertiary amines such as benzyldimethylamine, imidazole, metal salts of organic acids, Lewis acids, and amine complex salts. Not only one kind but also two or more kinds can be used in combination.

In the flame-retardant epoxy resin composition of the present invention, a solvent may be further used in combination, and there is no particular limitation, and various ones can be used as needed. 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. These solvents may be used as a mixture of two or more solvents as appropriate. It is also possible to use.

In the epoxy resin composition of the present invention, various additives, flame retardants, fillers, and the like can be appropriately compounded as needed.

Although the flame-retardant epoxy resin composition of the present invention is extremely useful for an electrodeposition laminate, it can be used in various applications such as an adhesive, a casting, and a paint by combining with a curing agent. That is, the epoxy resin composition of the present invention,
Non-halogen flame-retardant cured product can be obtained without lowering heat resistance, so it is suitable for applications such as sealing, lamination and coating, especially for glass epoxy laminates and IC encapsulants. It is suitable for paint applications such as resist. It is an object to provide an epoxy resin composition for coating.

Among the above-mentioned uses, particularly when used for an electric laminate, the electric laminate of the present invention can be obtained because of its excellent heat resistance.

That is, the electric laminate of the present invention is obtained by press-molding a plurality of prepregs containing a varnish containing an epoxy resin having an epoxy equivalent of 150 to 1000 g / eq, a phosphorus atom-containing epoxy resin, a curing agent and an organic solvent as essential components. It is characterized by being obtained.

Here, as the phosphorus atom-containing epoxy resin, the curing agent and the organic solvent, any of those exemplified as the epoxy resin composition of the present invention can be used. Therefore, the phosphorus atom-containing epoxy resin is preferably a halogen atom-free epoxy resin.

The method for producing a laminate from a varnish containing a phosphorus atom-containing epoxy resin, a curing agent and an organic solvent as essential components is not particularly limited, and it can be produced by a known and commonly used method. Such a substrate is impregnated with the epoxy resin composition of the present invention at a ratio of 30 to 70% by weight to obtain a prepreg, and then 1 to 10 prepregs are heated and pressed to obtain a prepreg.

[0052]

EXAMPLES Next, the present invention will be described specifically with reference examples, examples and comparative examples. In the examples, “parts” and “%” are all based on weight unless otherwise specified.

Example 1 100 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 188, 13 parts of monobutyl phosphate and 2 parts of diethanolamine were dissolved in 50 parts of MEK solution, and
The reaction was carried out at 5 ° C. for 5 hours to obtain a target resin having a P content of 2% and an epoxy equivalent of 400. Hereinafter, this is referred to as resin (A-1)
Abbreviated.

Example 2 100 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 188, 20 parts of monobutyl phosphate and 2 parts of a phenol novolak resin were dissolved in 50 parts of an MEK solution, and reacted at 80 ° C. for 5 hours. A target resin having a P content of 3% and an epoxy equivalent of 720 was obtained. Hereinafter, this is abbreviated as resin (A-2).

Synthesis Example 1 To 94 parts of phenol, 29 parts of 41.5% formalin and 0.47 parts of triethylamine were added and reacted at 80 ° C. for 3 hours. After adding 19 parts of melamine and further reacting for 1 hour, the temperature was raised to 120 ° C. while removing water under normal pressure, and the reaction was continued for 2 hours while maintaining the temperature. The temperature was raised to 180 ° C over 2 hours while removing water under normal pressure,
Then, unreacted phenol was removed under reduced pressure to obtain a phenol resin composition having a softening point of 136 ° C. Hereinafter, this is abbreviated as (D-1).

Examples 3 and 4 Resins (A-1) to (A-1) obtained in Examples 1 and 2
(A-2) is separately dissolved in methyl ethyl ketone, and then a curing agent dicyandiamide and a curing accelerator 2 previously dissolved in methyl cellosolve and dimethylformamide.
Ethyl 4-methylimidazole was added and the non-volatile content (N
A mixed solution of 55% was prepared. At this time, the amount of the curing agent is set to be a ratio of 0.5 equivalent to the epoxy group in the polyfunctional epoxy resin, and the amount of the curing accelerator is set so that the gel time of the prepreg becomes 120 seconds at 170 ° C. I made it.

Thereafter, using each mixed solution,
Glass cloth WE-18K-104-BZ2 as a base material
[Nittobo Co., Ltd.] was impregnated and dried at 160 ° C. for 3 minutes to prepare a prepreg having a resin content of 40%. Next, 9 sheets of the obtained prepregs were superposed, and the pressure was 3.9 MN / m.
2. The laminate was prepared by curing at a heating temperature of 170 ° C. and a heating time of 120 minutes.

For each of the obtained laminates, flame retardancy,
Each physical property such as Tg (glass transition temperature), peel strength and bending strength was tested. Table 1 shows the results. In addition, each test followed the following method. [Flame retardancy] Compliant with UL standard [Tg (glass transition temperature)] Measured by DMA method. Heating speed 3 ° C / min [Peel strength] Based on JIS-K6481.

Example 5 The resin (A-1) obtained in Example 1 was dissolved in methyl ethyl ketone, and then the curing agent phenol novolak resin (softening point: 80 ° C.) and (D-1) were obtained in Synthesis Example 3 The obtained curing agent and curing accelerator 2ethyl 4-methylimidazole were added to prepare a mixed solution having a nonvolatile content (NV) of 55%. At this time, the amount of the curing agent was set such that the phenolic hydroxyl group was 1.0 equivalent to the epoxy group in the polyfunctional epoxy resin, and the amount of the curing accelerator was 120 seconds at a gel time of the prepreg of 170 ° C. It became the ratio which becomes. Hereinafter, a laminate was prepared and evaluated in the same manner as in Examples 1 and 2. Table 1 shows the results.

[0060]

[Table 1] *: EPICLON 1050: BPA type epoxy resin *: EPICLON 3050: BPA type epoxy resin

Comparative Example 1 360 parts of a tetrabromobisphenol A type epoxy resin having an epoxy equivalent of 360 and a bromine content of 48%, 40 parts of monobutyl phosphate and 160 parts of toluene were mixed.
The mixture was reacted at 0 degree for 3 hours to obtain a resin having a P content of 1.5% and an epoxy equivalent of 1500. Hereinafter, this is referred to as (a-1).

Comparative Examples 2 and 3 EPICLON 1050 and EPICLON 7050 were separately 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 dimethyl formamide were added thereto. A mixed solution having a (NV) of 55% was prepared. At this time, the amount of the curing agent is set so as to be 0.5 equivalent to the epoxy group in the polyfunctional epoxy resin, and the amount of the curing accelerator is such that the gel time of the prepreg becomes 120 seconds at 170 ° C. I made it.

Hereinafter, a laminate was prepared and evaluated in the same manner as in Examples 1 and 2. Table 2 shows the results.

Comparative Example 4 A varnish was prepared and adjusted in the same manner as in Comparative Example 2 except that 80 parts of EPICLON 1050 and 20 parts of tricresyl phosphate (P content: 8%) were mixed.

Hereinafter, a laminate was prepared and evaluated in the same manner as in Examples 1 and 2. Table 2 shows the results.

Comparative Example 5 A varnish was prepared in the same manner as in Comparative Examples 2 and 3, except that the resin (a-1) synthesized in Comparative Example 1 was used.

Hereinafter, a laminate was prepared and evaluated in the same manner as in Examples 1 and 2. Table 2 shows the results.

[0068]

[Table 2]

[0069]

According to the present invention, a flame-retardant epoxy resin having excellent flame retardancy without deteriorating the basic properties of an epoxy resin cured product such as heat resistance, an epoxy resin composition containing the epoxy resin and An electrical laminate can be provided.

Claims (17)

[Claims] 1. A phosphorus atom-containing compound, comprising reacting an epoxy resin (A), phosphoric acid or a phosphoric ester (B), and a compound (C) having a functional group reactive with an epoxy group. Production method of epoxy resin. 2. The method according to claim 1, wherein the epoxy resin (A) is a halogen-free epoxy resin. 3. An epoxy resin (A), phosphoric acid or phosphoric ester (B), and a compound (C) having a functional group reactive with an epoxy group having an epoxy equivalent of 150
The method according to claim 1 or 2, wherein the reaction is carried out so as to be 1000 g / eq. 4. An epoxy resin (A) having an epoxy equivalent of 1
The method according to claim 3, wherein the amount is from 00 to 500 g / eq. 5. The reaction ratio of an epoxy resin (A), phosphoric acid or a phosphoric ester (B), and a compound (C) having a functional group reactive with an epoxy group is such that the epoxy group in the (A) The hydroxyl group and the ester group in (B) are in the range of 0.1 to 0.8 equivalent, and the functional group in (C) is in the range of 0.01 to 0.5 equivalent to 1 equivalent. 5. The production method according to any one of 4. 6. An epoxy resin (A), phosphoric acid or a phosphoric ester (B), and a compound (C) having a functional group reactive with an epoxy group at a reaction temperature of 0 to 150.
The method according to any one of claims 1 to 5, wherein the reaction is performed at a temperature of 0C in the presence of an organic solvent. 7. The method according to claim 1, wherein the compound (C) having a functional group reactive with an epoxy group is an alkanolamine. 8. An epoxy equivalent of 150 to 1000 g / eq.
A flame-retardant epoxy resin composition comprising, as essential components, a phosphorus atom-containing epoxy resin and a curing agent. 9. The composition according to claim 8, wherein the phosphorus atom-containing epoxy resin is a halogen atom-free epoxy resin. 10. An epoxy resin containing a phosphorus atom, comprising: an epoxy resin (A) and a phosphoric acid or a phosphoric ester (B).
The composition according to claim 8 or 9, which is obtained by reacting a compound (C) having a functional group having reactivity with an epoxy group. 11. The composition according to claim 8, wherein the curing agent contains a nitrogen atom. 12. The composition according to claim 8, wherein the curing agent is a mixture or condensate of formaldehyde with a compound having a phenol and a triazine ring. 13. An epoxy equivalent of 150 to 1000 g / e.
An electric laminate obtained by pressure-molding a plurality of prepregs containing a varnish containing, as essential components, a q-phosphorus atom-containing epoxy resin, a curing agent and an organic solvent. 14. The electric laminate according to claim 13, wherein the phosphorus atom-containing epoxy resin is a halogen atom-free epoxy resin. 15. An epoxy resin containing a phosphorus atom, comprising: an epoxy resin (A) and a phosphoric acid or a phosphoric ester (B).
The electric laminate according to claim 13 or 14, which is obtained by reacting a compound (C) having a functional group having reactivity with an epoxy group. 16. The electric laminate according to claim 13, wherein the curing agent contains a nitrogen atom. 17. The electric laminate according to claim 13, wherein the curing agent is a mixture or a condensate of phenols, a compound having a triazine ring and formaldehyde.