JPH0532764A - Epoxy resin composition and production of epoxy resin - Google Patents

Abstract

PURPOSE:To produce an epoxy resin having excellent adhesivity and useful for coatings, laminates, adhesives. etc., by reacting a condensed multi-cyclic aromatic compound having epoxy groups with a compound having phenolic hydroxy groups. CONSTITUTION:(A) A condensed maul ti-cyclic aromatic compound having two or more epoxy groups and e.g. obtained by the reaction of a dihydronaphthalene with an epihalohydrin is reacted with (B) a compound having two or more phenolic hydroxyl groups such as bisphenol A or tetrabromobisphenol A, if necessary, in the presence of a catalyst to produce an epoxy resin. The epoxy resin is compounded with a curing agent such as dicyandiamide to provide an epoxy resin composition. 100 pts.wt. of the component A is preferably reacted with 40-70 pts.wt. of the component B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition useful for paints, laminates, adhesives, etc. and a method for producing an epoxy resin.

[0002]

2. Description of the Related Art Bisphenol A type epoxy resins or bisphenol F type epoxy resins have hitherto been used in paints, laminates, adhesives and the like because of their low epoxy equivalents and poor adhesion and toughness of cured products. A so-called polymer epoxy resin in which a resin is polymerized to some extent with a chain extender such as bisphenol A, bisphenol F, or tetrabromobisphenol A is generally used.

However, this polymer epoxy resin has a drawback that it is superior in adhesiveness to liquid resin but inferior in heat resistance, and in order to improve this point, for example, "new epoxy resin" (edited by Hiroshi Kakiuchi, (Published in May, 1985) discloses a technique for increasing crosslink density by blending a polyfunctional epoxy resin and a novolac epoxy resin with a polymer epoxy resin.

[0004]

However, although the technology described in the above "new epoxy resin" (edited by Hiroshi Kakiuchi, published in May 1985) can improve the heat resistance of the epoxy resin, this time There was a problem of poor adhesion.

The problem to be solved by the present invention is that the adhesiveness is excellent while maintaining the conventional heat resistance, and coating materials, laminates,
It is to provide an epoxy resin useful as an adhesive or the like.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted diligent research in order to obtain a polymer epoxy resin having excellent heat resistance and adhesiveness in view of the actual situation in the above-mentioned prior art. It has been found that these problems can be solved by using a polymer epoxy resin having a structure in which a compound having at least two phenolic hydroxyl groups is reacted with a condensed polycyclic aromatic compound having a number of these, and the present invention is completed. Came to.

That is, the present invention provides an epoxy resin composition containing an epoxy resin and a curing agent as essential components, wherein the epoxy resin is at least a condensed polycyclic aromatic compound having at least two epoxy groups and a phenolic hydroxyl group. An epoxy resin composition characterized by using a polymer epoxy resin obtained by reacting a compound having two epoxy compounds, and a condensed polycyclic aromatic compound having at least two epoxy groups, and at least two phenolic hydroxyl groups. The present invention relates to a method for producing a high molecular weight epoxy resin, which comprises reacting an individual compound.

The polymer epoxy resin used in the present invention is obtained by reacting a condensed polycyclic aromatic compound having at least two epoxy groups with a compound chain having at least two phenolic hydroxyl groups. The softening point is preferably 70 to 120 ° C. When the softening point is within this range, excellent fluidity can be obtained because the viscosity of the epoxy resin can be suppressed low, and excellent processability after the epoxy resin is used as an epoxy resin can be obtained. In order to realize this softening point, the molecular weight of the polymer epoxy resin of the present invention is preferably 500 to 2000, and particularly preferably 500 to 1500.

The condensed polycyclic aromatic compound in the condensed polycyclic aromatic compound having at least two epoxy groups used in the present invention may have a substituent and share a π electron cloud. It refers to a compound formed from a plurality of benzene rings, and examples thereof include compounds having a naphthalene skeleton, anthracene skeleton, and pyrene skeleton, but having an naphthalene skeleton from the viewpoint of obtaining an appropriate softening point when used as an epoxy resin composition. Compounds are particularly preferred.

The fused polycyclic aromatic compound having at least two epoxy groups used in the present invention is not particularly limited, and any known and commonly used one can be used, but the epoxy equivalent is 100 to 250. Things are preferable,
For example, a so-called naphthalene-based compound in which two or more epoxy groups are introduced into the above-mentioned compound having a naphthalene skeleton is mentioned, and more specifically, 1,5-diglycidyl naphthalene, 1,6-diglycidyl naphthalene, 1,7. -Diglycidylnaphthalene, 1,8-diglycidylnaphthalene,
2,5-diglycidylnaphthalene, 2,6-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, 2,
8-diglycidylnaphthalene and the like can be mentioned. Among them, 1,6-diglycidylnaphthalene is particularly preferable in that suitable flowability can be obtained when the epoxy resin of the present invention is used.

The method for producing the condensed polycyclic aromatic compound having at least two epoxy groups is not limited, and examples thereof include a method of reacting dihydroxynaphthalene with epihalohydrin.

The compound having at least two phenolic hydroxyl groups used in the present invention is used as a chain extender, and any known compound can be used. For example, dihydric phenols such as resorcin, catechol and hydroquinone, and bisphenol A. , Bisphenol F, bisphenol S, tetrabromobisphenol A, bisphenol AD, and other bisphenol-based compounds, biphenol-based compounds, dihydroxynaphthalene, and the like, but bisphenol-based compounds are preferred, and the effect of the present invention is particularly remarkable. Bisphenol A and tetrabromobisphenol A are preferred.

The production method of the present invention is characterized by reacting a condensed polycyclic aromatic compound having at least two epoxy groups with a compound having at least two phenolic hydroxyl groups as a chain extender. Although the conditions and the like are not limited, for example, the following methods can be mentioned.

The above raw materials may be reacted at 100 to 200 ° C. for 1 to 10 hours in the presence of a catalyst, if necessary, with a condensed polycyclic aromatic compound having at least two epoxy groups and a chain extender. For the purpose of adjusting the melt viscosity and the like, a bisphenol A type, a bisphenol F type, a tetrabromobisphenol A type, a novolac type epoxy are optionally used together with a condensed polycyclic aromatic compound having at least two epoxy groups as an epoxy resin component. Other epoxy resins such as resins can be used together.

Examples of the catalyst that can be used in this case include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, tertiary amines such as triethylamine and benzyldimethylamine, and quaternary ammonium such as tetramethylammonium chloride. Examples thereof include salts and imidazole compounds.

When carrying out the reaction, an organic solvent may be used if necessary. Examples of the organic solvent include toluene, xylene, Solvesso and the like. The reaction ratio of the condensed polycyclic aromatic compound having at least two epoxy groups and the chain extender is not particularly limited,
The molar ratio of the condensed polycyclic aromatic compound having at least two epoxy groups to the chain extender is 100/5 to 100/9.
With respect to the reaction ratio of 5, a reaction ratio of 100/40 to 100/70 is preferable from the viewpoint of obtaining an appropriate molecular weight and softening point.

As the curing agent used in the epoxy resin composition of the present invention, any of known and commonly used compounds can be used. Among them, typical examples include dicyandiamide, imidazole, BF3 -amine complex, guanidine derivative and the like. Latent curing agents, phenols, various novolak resins derived from substituted phenols and bisphenols and modified products thereof, aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, polyamide resins and modified products thereof, Examples thereof include acid anhydride type curing agents such as maleic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and pyromellitic dianhydride. These curing agents may be used alone or in combination of two or more. As the curing agent, it is preferable to use one for room temperature curing and one for heat curing depending on the application.

The amount of these curing agents used is not particularly limited, but it is obtained by mixing the curing agent in a ratio of 2 to 70 parts by weight with respect to 100 parts by weight of the solid content of the epoxy resin. However, it should be noted that such a mixing ratio largely changes depending on the type of the curing agent used, and thus the optimum conditions are appropriately determined.

When each of the compounds listed above is used as a curing agent, a curing accelerator can be used appropriately. As the curing accelerator, any conventionally known one can be used, and examples thereof include tertiary amine, imidazole, organic acid metal salt, Lewis acid, amine complex salt, and the like, and these are not only single but also two or more kinds. It can be used together.

If necessary, other components such as a filler, a fiber, a coupling agent, a flame retardant, a release agent, and a foaming agent can be added to the epoxy resin composition of the present invention.
Examples of the filler at this time include polyethylene powder, polypropylene powder, quartz, silica, silicates, calcium carbonate, magnesium carbonate, gypsum, bentonite, fluorite,
Titanium dioxide, carbon black, graphite, iron oxide, aluminum powder, iron powder, talc, mica, kaolin clay, etc., as the fiber, for example, cellulose fiber, glass fiber, carbon fiber, aramid fiber, etc., as the coupling agent. For example, silane coupling agents, titanium coupling agents, etc., flame retardants such as brominated bisphenol A, antimony trioxide, phosphorus compounds, etc., release agents such as stearates, silicones, waxes, etc. However, examples of the foaming agent include freon, dichloroethane,
Butane, pentane, dinitropentamethylenetetramine, paratoluenesulfonyl hydrazide, or
Examples include expandable thermoplastic resin particles in which freon, dichloroethane, butane, pentane and the like are filled in the shell of a vinyl chloride-vinylidene chloride copolymer or a styrene- (meth) acrylic acid ester copolymer.

The epoxy resin composition of the present invention can be used in various applications such as paints, laminates, adhesives, casting, etc., if necessary in combination with a curing agent. For example, for powder coating, it is preferable because it has good gap filling properties and excellent adhesion, and for laminates, epoxy resin of this structure has extremely high heat resistance and adhesion to copper foil and interlayers. It is preferable because it is excellent.

[0022]

EXAMPLES Next, the present invention will be specifically described with reference to Reference Examples, Examples and Comparative Examples. In the examples, all parts and% are by weight unless otherwise specified.

Reference Example 1 1,6 diglycidyl naphthalene type epoxy resin EPIC
LON HP-4032 [Dainippon Ink and Chemicals, Inc.]
Manufactured by Epoxy Equivalent 150] and 35 parts of bisphenol A are added and heated to 120 ° C. and stirred, and further 2
Add 0.01 parts of methyl imidazole and 150 ° C
At room temperature for 4 hours to obtain a solid epoxy resin of interest having an epoxy equivalent of 480, a number average molecular weight of 920 and a softening point of 100 ° C. Hereinafter, this is abbreviated as resin (A-1).

Reference Example 2 60 parts of EPICLON HP-4032, bisphenol A type epoxy resin EPICLON 850 (manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 188) 10
Example 1 except that 30 parts of bisphenol A and 30 parts of bisphenol A were used
And epoxy equivalent 540, number average molecular weight 95
A solid epoxy resin having a softening point of 0 and a softening point of 100 ° C. was obtained. Hereinafter, this is abbreviated as resin (A-2).

Reference Example 3 Epoxy equivalent 360 and bromine content 20 in the same manner as in Reference Example 1 except that 66 parts of EPICLON HP-4032 and 34 parts of tetrabromobisphenol A were used.
%, A number average molecular weight of 600 and a softening point of 78.degree. Hereafter, the resin (A
-3) is abbreviated.

Reference Example 4 56 parts of EPICLON HP-4032, bisphenol A novolac type epoxy resin EPICLON N
-865 (manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 205, softening point 70 ° C.) 10 parts, except that tetrabrom bisphenol A 34 parts was used, epoxy equivalent 350, and A solid epoxy resin having a bromine content of 20%, a number average molecular weight of 750 and a softening point of 85 ° C. was obtained. Hereinafter, this is abbreviated as resin (A-4).

Examples 1 and 2 and Comparative Examples 1 to 3 The predetermined resins shown in Table 1 were mixed in a predetermined composition ratio, and then melt-kneaded with a co-kneader manufactured by Bus Co., which was then crushed and passed through a 50-mesh wire mesh. Minute powder coating was prepared. Applying these various powder coatings by electrostatic spray,
After curing at 0 ° C. for 20 minutes, the physical properties were measured. The results are shown in Table 1. The physical properties shown in Table 1 were measured as follows. (Cross-cut adhesion test) It was performed in accordance with JIS C-D202.

[0028]

[Table 1]

Note 1) EPICLON 4050 manufactured by Dainippon Ink and Chemicals, Inc., bisphenol A type epoxy resin, epoxy equivalent 940, softening point 100 ° C Note 2) EPICLON N-673 manufactured by Dainippon Ink and Chemicals, Inc., Cresol Novolac type epoxy resin, epoxy equivalent 210, softening point 80 ° C. Examples 3 to 4 and Comparative Examples 4 to 5 Predetermined resins shown in Table 2 are individually dissolved with methyl ethyl ketone, and then dicyandiamide previously dissolved in methyl cellosolve. (Curing agent) and 2-ethyl-4-methylimidazole (curing accelerator) were added to prepare a mixed solution having a nonvolatile content (hereinafter abbreviated as NV) of 55%. At this time, the amount of the curing agent is set to be 0.5 equivalent to the epoxy group in the epoxy resin, and the amount of the curing accelerator is such that the gel time of the prepreg is 170 ° C.
It was set to 120 seconds. Then, using each mixed solution, the glass cloth WE-18 which is the base material
K-127-RB84 (manufactured by Nitto Boseki Co., Ltd.) was impregnated and dried at 160 ° C. for 3 minutes to prepare a prepreg having a resin content of 40%. Next, nine obtained prepregs were superposed and cured under the conditions of a pressure of 40 kg / cm @ 2, a heating temperature of 170.degree. The results are shown in Table 2. The physical properties shown in Table 2 were measured as follows. (Copper foil peeling strength) Measured in accordance with JIS C-6481. (Soldering resistance) A test piece subjected to a pressure cooker test at 120 ° C for 4 hours was floated on molten solder at 260 ° C, and the appearance of the test piece, particularly the presence or absence of "blister" was evaluated by visual judgment.

[0030] ◎ ... No abnormalities ○: Almost no abnormality, slight "blister" ×… "Blistering" occurred

[0031]

[Table 2]

Note 3) EPICLON 1120 manufactured by Dainippon Ink and Chemicals, Inc., Low-Br type epoxy resin, epoxy equivalent 480, bromine content 20%

[0033]

The cured product obtained from the polymer epoxy resin and the epoxy resin composition of the present invention is characterized by excellent heat resistance and adhesiveness.

Therefore, the epoxy resin composition of the present invention is extremely useful for various applications such as paints, laminates, adhesives and casting.

Claims (9)

[Claims] 1. An epoxy resin composition comprising an epoxy resin and a curing agent as essential components, wherein the epoxy resin has a condensed polycyclic aromatic compound having at least two epoxy groups and at least two phenolic hydroxyl groups. An epoxy resin composition comprising a polymer epoxy resin obtained by reacting with a chain extender. 2. The softening point of the polymer epoxy resin is 70-1.
The composition according to claim 1, which is at 20 ° C. 3. The composition according to claim 1, wherein a polymer epoxy resin obtained by reacting 40 to 70 parts of a chain extender with 100 parts by weight of an aromatic compound having at least two epoxy groups is used. 4. The composition according to claim 1, 2 or 3, wherein the condensed polycyclic aromatic compound having at least two epoxy groups is diglycidylnaphthalene. 5. The composition according to claim 1, wherein the chain extender having at least two phenolic hydroxyl groups is a bisphenol compound. 6. A method for producing a polymer epoxy resin, which comprises reacting a condensed polycyclic aromatic compound having at least two epoxy groups with a compound having at least two phenolic hydroxyl groups. 7. The production method according to claim 6, wherein 40 to 70 parts by weight of a compound having at least two phenolic hydroxyl groups is reacted with 100 parts by weight of a condensed polycyclic aromatic compound having at least two epoxy groups. 8. The method according to claim 6, wherein the condensed polycyclic aromatic compound having at least two epoxy groups is diglycidylnaphthalene. 9. The method according to claim 6, 7 or 8, wherein the chain extender is a bisphenol compound.