JPS6317852B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a resin obtained from a novel polyglycidyl ether. The epoxy resin obtained from the polyglycidyl ether of the present invention is a heat-resistant thermosetting resin, and has excellent heat resistance and water absorption with a glass transition temperature of 230°C or higher, preferably 250°C or higher, particularly preferably 280°C or higher. is small, and can be used as a highly heat-resistant composite material when, for example, high modulus fibers (carbon fiber, aramid fiber, etc.) are used as a reinforcing material. Prior art Methods for producing heat-resistant epoxy resin include (1)
Curing tetraglycidyl methylene dianiline and diaminodiphenylsulfone, (2) Curing polyglycidyl ether of phenol novolak with diaminodiphenylsulfone, (3) Using dicyandiamide as a curing agent in place of the above diaminodiphenylsulfone. Such methods are well known. However, the materials obtained by these methods also have drawbacks such as insufficient heat resistance and high water absorption. It is also known to condense β-naphthol and formalin, react it with epichlorohydrin to obtain a polyglycidyl ether having a naphthalene skeleton, and then cure the polyglycidyl ether with a conventionally known curing agent. However, the naphthalene skeleton-containing polyglycidyl ether obtained starting from this β-naphthol can only be a dimer due to the reactivity of β-naphthol, and therefore becomes a diglycidyl ether. And although this diglycidyl ether has a low degree of polymerization, its own melting point is
It has a high temperature of 170°C or higher, has poor solubility in solvents, and is difficult to handle. Furthermore, even if it is cured using a curing agent, a resin with good heat resistance cannot be obtained. Purpose of the Invention The purpose of the present invention is to create a composite material made by curing polyglycidyl ether, which provides an epoxy resin with excellent heat resistance and low water absorption, using a curing agent and reinforcing it with high elastic fibers (carbon fiber, aramid fiber, etc.). The object of the present invention is to provide a composite material that has excellent heat resistance and moist heat resistance when formed. Structure of the Invention The present invention provides (1) a polyglycidyl ether represented by the following formula (). [However, G is

[Formula] or

[Formula] is represented, and R ₁ represents a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. However, if R ₁ represents an aromatic hydrocarbon group that may be substituted with a halogen atom,
The hydrogen atom in R ₁ may be substituted with a group -OG. n is an integer of 1 or more when R ₁ does not have a substituent of -OG, and is an integer of 0 or 1 or more when R ₁ has a substituent of -OG. ] It is an epoxy resin obtained by curing. In the novel polygalicidyl ether according to the present invention, α-naphthol is the main phenol component. A small proportion of phenol relative to α-naphthol,
Cresol, xylenol, hydroxybenzene or its lower alkyl substituted products, β-naphthol, and other phenols used in the production of conventionally known phenol novolaks can be used as copolymerization components, but preferably only α-naphthol is the phenol. It is an ingredient. In the novel polyglycidyl ether according to the present invention, the main aldehyde component has the following formula () R ₂ -CHO () [However, R ₂ is as defined above. ] It is expressed as . Specific examples of _R2 include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and octyl, chloromethyl, cyclohexyl,
Methylcyclohexyl, phenyl, tolyl, dimethylphenyl, ethylphenyl, hydroxyphenyl, chlorphenyl, bromphenyl, methoxyphenyl, and naphthyl are preferred.
Examples of R ₂ are aromatic hydrocarbon groups optionally substituted with lower alkyl groups such as methyl, ethyl, and propyl, and hydroxyl groups such as phenyl, tolyl, and hydroxyphenyl; among these, R ₂ is a methyl group,
A hydroxyphenyl group is particularly preferred, and more preferably R ₂ is hydroxyphenyl. The novel polyglycidyl ether of the present invention is produced according to the conventional method for producing polyglycidyl ether of phenol novolac, but since phenol and α-naphthol have different reactivities, it is preferable to use α-naphthol instead of the method via resol. A novolac-type naphthol resin containing a naphthol component in the molecule is produced by directly reacting the aldehyde represented by the above formula () under an acidic catalyst, and this resin is reacted with epichlorohydrin or β-methylepichlorohydrin to produce a polyglycidyl ether. It is better to use this method. Here, the ratio of aldehyde to α-naphthol is adjusted depending on the degree of polymerization of the target resin, but is usually 0.5 to 1 mole of α-naphthol.
A range of mol or more and 1.5 mol or less is often used. In addition, specific examples of acidic catalysts include nitric acid, sulfuric acid,
Protic acids such as hydrochloric acid, phosphoric acid, methanesulfonic acid, and toluenesulfonic acid; Lewis acids such as boric trifluoride, boron trifluoride ether complex, aluminum chloride, tin chloride, zinc chloride, iron chloride, and titanium chloride; An acid etc. can be used. Among these, it is preferable to use protonic acids, and hydrochloric acid, sulfuric acid, methanesulfonic acid, toluenesulfonic acid, etc. are particularly preferably used. The amount of these catalysts to be used is selected to be 0.001 to 0.05 moles relative to the raw material α-naphthol. In the present invention, α-naphthol as a phenol component and the above formula () as an aldehyde component
The reaction of the aldehyde represented by the formula in the presence of an acidic catalyst is usually carried out at a temperature of 80 to 250°C. Further, this reaction temperature is carried out at a temperature of 80 to 150° C. in the initial stage, and the reaction temperature is further increased as necessary. Moreover, the reaction time can be selected within the range of 1 hour to 10 hours. When the above reaction of the present invention is carried out without a solvent, it is desirable to raise the temperature because the melting point of the novolak naphthol resin increases as the degree of polymerization increases. In the above reaction, aromatic hydrocarbons such as toluene, chlorobenzene, dichlorobenzene, nitrobenzene, and diphenyl ether, and ethers such as dimethyl ether such as ethylene glycol and diethylene glycol can be used as solvents. Thus, the following formula () [However, R ₂ and n in the formula are the same as defined above. ] A novolak type naphthol resin represented by the following is obtained. Next, the polyglycidyl ether according to the present invention can be obtained by reacting the novolac type naphthol resin synthesized by the above method with epirochlorohydrin or β-methylepichlorohydrin. This reaction can be carried out in accordance with the conventionally known method for obtaining polyglycidyl ether from novolak type phenolic resin and epichlorohydrin or β-methylepichlorohydrin. This reaction is carried out by (1) adding a solid or concentrated aqueous solution of an alkali metal hydroxide such as caustic soda or caustic potash to a mixture of novolak-type naphthol resin and excess epichlorohydrin, and reacting at a temperature between 60 and 120°C. (2) Novolac-type naphthol resin and excess epichlorohydrin or β-methylepichlorohydrin with tetramethylammonium chloride,
Add a catalytic amount of quaternary ammonium salt such as tetraethylammonium bromide or trimethylbenzylammonium chloride and heat at 70 to 150°C.
A solid or concentrated aqueous solution of an alkali metal hydroxide such as caustic soda or caustic potash is added to the polyhalohydrin ether obtained by the reaction.
This is a method of ring-closing polyhalohydrin ether by reacting at a temperature between 60 and 120°C to form the desired polyglycidyl ether. In the above method, the amount of epichlorohydrin or β-methylepichlorohydrin to be used is 5 to 20 times the mole when method (1) is used, preferably 10 to 15 times the mole when method (2) is used, based on the hydroxyl group in the novolak naphthol. When using methods (1) and (2), it is in the range of 5 to 20 times the mole, preferably 5 to 15 times the mole, and the amount of alkali metal hydroxide such as caustic soda and caustic potash is in the novolac type naphthol as well as in methods (1) and (2). The molar range is 0.8 to 1.2 times the hydroxyl group of (2)
When using the method described above, the quaternary ammonium salt is used in an amount of 0.001 to 0.02 moles relative to the hydroxyl group in the novolak naphthol. Further, this reaction is carried out for a period of 1 hour to 10 hours. As mentioned above, the polyglycidyl ether obtained by the reaction of the present invention contains water-soluble inorganic substances such as alkali metal halides in addition to unreacted epichlorohydrin or β-methylepichlorohydrin. After epichlorohydrin or β-methylepichlorohydrin is removed by distillation, water-soluble inorganic substances can be removed by extraction with water, filtration, or other methods to obtain a polyglycidyl ether suitable for producing an epoxy resin. Thus, the following equation () [However, in the formula, G, R ₁ and n are the same as defined above. ] A polyglycidyl ether represented by the following is obtained. The polyglycidyl ether obtained here is further mixed with an aqueous solution of an alkali metal hydroxide such as caustic soda or caustic potash at a temperature of 60 to 100°C, for example.
By heating the polyglycidyl ether for 1 to 20 hours, the halogen content in the polyglycidyl ether can be reduced. In this case, the polyglycidyl ether is preferably dissolved in an organic solvent such as methyl butyl ketone, benzene, or toluene. The novel polyglycidyl ether according to the present invention is synthesized from a novolak-type naphthol resin represented by the above formula (). In formula (), n is R ₂
Depends on the type. The novolak-type naphthol resin used in the present invention contains two or more naphthalene nuclei and three aromatic nuclei having hydroxyl groups.
It has more than one. Here, the number of aromatic nuclei having hydroxyl groups is preferably in the range of 3 to 10, and particularly the number of aromatic nuclei having hydroxyl groups is selected in the range of 4 to 7. Therefore, in the above formula (), n is 1 to 8, preferably 2 to 5 when R ₂ is a hydrocarbon group having 10 or less carbon atoms that is not substituted with -OH.
and when R ₂ is a hydrocarbon group substituted with -OH and having 10 or less carbon atoms, the range is 0 to 4. If n is small, the heat resistance of the resulting epoxy resin will be poor, and if n is too large, the reaction yield of polyglycidyl ether from novolak naphthol resin will tend to be poor, and the viscosity of the polyglycidyl ether when melted will be low. This is not preferable because it deteriorates the moldability after finishing. The polyglycidyl ether according to the present invention has 3 or more glycidyl groups, preferably 3 to 3 glycidyl groups in the molecule.
It has in the range of 10, especially in the range of 4 to 7. The polyglycidyl ether according to the present invention has a melting point in the range of 50 to 150°C, and also has excellent solubility in solvents, as will be seen in the following explanation. The new polyglycidyl ether according to the present invention can be cured with a conventionally known epoxy curing agent ("Epoxy Resin" edited by Hiroshi Kakiuchi (Shokodo), 1972).
(Published September 30, 2015, pp. 109-149). These include amines,
Examples include acid anhydrides, polyamide resins, polysulfide resins, boron trifluoride amine complexes, novolak resins, and dicineandiamide. Specifically, aliphatic amines such as diethylenetriamine, triethylenetetramine, 1,3-diaminocyclohexane, isophoronediamine, m-xylylenediamine; metaphenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl Methane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,4-tolylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, Aromatic amines such as aniline-formalin resins; monoepoxy compounds (ethylene oxide, phenyl glycidyl ether, butyl glycidyl ether, etc.), polyepoxy compounds (diglycidyl ether of bisphenol A, resorcinol) with the above aliphatic amines or aromatic amines; diglycidyl ether, etc.) or adducts with acrylonitrile, etc.; phthalic anhydride, hexahydrophthalic anhydride, nadzic anhydride, methyl nadzic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, trimellitic anhydride acid anhydrides such as glycerin tristris trimellitate and ethylene glycol bis trimellitate; dimer acids and polyamide resins such as diethylenetetramine and triethylenetetramine; polysphide resins with mercaptan groups at both ends; aniline, N-methylaniline, benzyl These include complexes of amines such as amines and ethylamine and boron trifluoride; low molecular weight novolak resins obtained from phenolic cresol and formalin; and dicyamidiamide. As mentioned above, the raw material polyglycidyl ether of the present invention can be cured with conventionally known curing agents for epoxy resins, but particularly excellent effects are exhibited when it is cured with aromatic polyamines and/or dicyandiamide. Among these, 4,4'-diaminodiphenyl sulfone and dicyandiamide are particularly preferably used. The epoxy resin of the present invention is obtained by curing the polyglycidyl ether together with the epoxy curing agent as described above. Here, the amount of aminos, polyamide resin, polysulfide resin, boron trifluoride amine complex, novolak resin, etc. used is determined by the amount of active hydrogen in these curing agents relative to the amount of epoxy groups contained in the polyglycidyl ether. The amount of acid anhydride used is 0.5 to 1.0 mol based on the amount of epoxy groups contained in the polyglycidyl ether, so that the amount is 0.5 to 1.5 mol, preferably 0.8 to 1.2 mol. Double the amount, preferably
The amount of dicyamidiamide used is 1/20 to 1/3 times the amount of epoxy contained in the polyglycidyl ether, preferably 1/10 to 1/4 times the amount by mole, so that the amount is 0.6 to 0.9 times the amount by mole. It is twice as many moles. A small proportion of a curing accelerator can be used in the curing reaction, if necessary. Examples of the curing accelerator include tertiary amines such as toluethylamine, tributylamine, and dimethylbenzylamine, phenols such as phenol, cresol, butylphenol, nonylphenol, chlorophenol, resorcinol, and polyvinylphenol; imidazole, and 2-
Examples include imidazoles such as ethyl-4-methylimidazole; or salts thereof such as acetates. The polyglycidyl ether of the present invention can be cured as it is by adding the curing agent and a curing accelerator if necessary, but ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, and diethyl ketone; alcohols such as methyl cellosolve and ethyl cellosolve; Cyclic ethers such as dioxane and tetrahydrofuran; dimethylformamide,
Amides such as dimethylacetamide and N-methylpyrrolidone; benzene, toluene, xylene,
It is also possible to uniformly disperse or dissolve the curing agent and, if necessary, the curing accelerator, by dissolving it in aromatic hydrocarbons such as cumene, etc., and then removing the solvent and curing. The curing reaction of polyglycidyl ether in the present invention proceeds even at 60°C or higher, but preferably at 100°C or higher.
It can be carried out by heating to a temperature between ℃ or higher and 250℃. Curing time is usually 0.5 to 5 hours. Further, the heat resistance of the cured product obtained here is improved by curing preferably at a temperature of 150° C. or higher. Effect The epoxy resin of the present invention, which is cured with the above-mentioned aromatic polyamine, dicyandiamide, acid anhydride, etc., has a glass transition temperature of 230°C or higher,
Preferably 250°C or higher, more preferably 270°C or higher, particularly preferably 280°C or higher, particularly preferably
Water absorption rate at 280℃ or higher and in water at 100℃ is less than 0.4,
It is preferably 0.35% or less, particularly preferably 0.3% or less, and exhibits excellent water resistance. According to research conducted by the present inventors, the water absorption rate of epoxy resin obtained by using phenol instead of α-naphthol is 0.4% or more, whereas the epoxy resin of the present invention has not only heat resistance but also It is clear that it also has excellent water resistance. Since the resin obtained from the polyglycidyl ether of the present invention has such characteristics, it can provide an excellent highly heat-resistant composite material, especially when high elastic fibers (carbon fiber, aramid fiber, etc.) are used as a reinforcing material. It is something. Next, the present invention will be described with reference to Examples. In the examples, "parts" represent "parts by weight." Reference Example 1 144 parts of α-naphthol and 82 parts of p-oxybenzaldehyde were heated and melted at 130°C, and 36 parts of
0.2 parts of % hydrochloric acid and 0.3 parts of p-toluenesulfonic acid were added and reacted by heating at 100°C for 1 hour, then at 190°C to 200°C for 8 hours. At this time, water produced as a result of the reaction was distilled out of the reaction system. The reaction product obtained here was taken out from the reactor, pulverized, washed with hot water, and then dried. The obtained novolac-type naphthol resin was 207 parts, had a melting point of 300°C or higher, and had a molecular weight of 535, determined by the freezing point depression method after dissolving in dioxane (containing an average of 2.6 naphthol components and an average of 1.6 p-hydroxybenzaldehyde components in the molecule). , and contained 4.2 hydroxyl groups in the molecule).
The infrared absorption spectrum of this novolak naphthol resin is shown in FIG. Next, 1,440 parts of epichlorohydrin and 2.4 parts of trimethylbenzylammonium chloride were added to 200 parts of this novolak-type naphthol resin to make 110~
The mixture was heated at 120°C for 3 hours, and then 135 parts of a 50% aqueous solution of caustic soda was added over 2 hours while heating to 80°C under reduced pressure. During this time, water was removed from the system by azeotropy between water and shrimp chlorohydrin. Next, a caustic soda aqueous solution was added, and the reaction was continued by heating at the same temperature for another 2 hours while removing water from the system. After the reaction is complete, epichlorohydrin is distilled off under reduced pressure, extracted with methyl isophthyl ketone, washed with water to remove caustic soda and sodium chloride, and washed with aqueous phosphoric acid until the methyl isobutyl ketone solution becomes neutral. After washing with water, methyl isobutyl ketone was finally removed under reduced pressure to obtain 250 parts of the desired polyglycidyl ether. The polyglycidyl ether obtained here has a melting point of
The epoxy equivalent determined by the hydrochloric acid dioxane method at 110° C. was 240 (g/equivalent), and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 800.
Further, the infrared absorption spectrum of polyglycidyl ether is shown in FIG. Reference example 2 α-naphthol 144 parts, benzaldehyde 84.8 parts
After heating to 100℃, add 36%
Add 0.4 parts of hydrochloric acid and 0.3 parts of p-toluenesulfonic acid.
9 while continuing to heat up to 180℃ at 100℃ for 1 hour.
Allowed time to react. During this time, water produced in the reaction was distilled out of the system. The reaction product obtained here was taken out from the reactor, washed with hot water, and then dried. The obtained novolac type resin was 210 parts and had a melting point of 240.
The molecular weight determined by the freezing point depression method after dissolving in dioxane at 100°C was 705 (the molecule contains 3.4 hydroxyl groups along with a naphthol component). The infrared absorption spectrum of this novolak naphthol resin is shown in FIG. Reference Example 1 1650 parts of epichlorohydrin and 2 parts of trimethylbenzylammonium chloride were added to 200 parts of the novolac type naphthol resin obtained here.
After carrying out an addition reaction in the same manner as above, 84 parts of a 50% aqueous solution of caustic soda was added over 2 hours. Reference example 1 after this
After reacting in the same manner as above, epichlorohydrin was removed, the reaction product was extracted with methyl isobutyl ketone, washed with water, and finally methyl isobutyl ketone was removed under reduced pressure to obtain 220 parts of the desired polyglycidyl ether. Ta. The polyglycidyl ether obtained here has a melting point of
The epoxy equivalent determined by the hydrochloric acid dioxane method at 150° C. was 275 (g/equivalent), and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 900.
Further, the infrared absorption spectrum of polyglycidyl ether is shown in FIG. Reference example 3 144 parts of α-naphthol and 90% acetaldehyde
Mix 44 parts, add 0.3 part of 36% hydrochloric acid, mix at room temperature, gradually raise the temperature, and react at 100°C for 12 hours.
Then, the temperature was raised to 140°C and the reaction was continued for an additional 6 hours. The reaction product was taken out from the reactor, pulverized, washed with water and dried to obtain 156 parts of a novolac type naphthol resin. The melting point was 120°C, and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 650 (the molecule contains 4 hydroxyl groups along with a naphthol component). The infrared absorption spectrum of this resin is shown in FIG. 120 parts of the novolac type naphthol resin obtained here was dissolved in 1100 parts of epichlorohydrin, and
68 parts of 50% caustic soda was added over 2 hours while heating to .degree. During this time, water was azeotroped with epichlorohydrin and removed from the system. After the addition of caustic soda, the reaction was continued for 2 hours while water under reduced pressure was azeotropically removed from the system. After that, excess epichlorohydrin was distilled off under reduced pressure, toluene and water were added to the residue, and the polyglycidyl ether was dissolved in the toluene side. Inorganic substances including sodium chloride were dissolved in the water side and extracted and removed. A toluene solution of was obtained, and then toluene was removed again under reduced pressure to obtain 130 parts of the desired polyglycidyl ether. The polyglycidyl ether obtained here has a melting point of 110
The epoxy equivalent determined by the hydrochloric acid dioxane method at °C is
240 (g/equivalent), and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 890.
Further, the infrared absorption spectrum of polyglycidyl ether is shown in FIG. Reference example 4 α-naphthol 144 parts, salicylaldehyde 90
Add 0.3 parts of benzenesulfonic acid to the mixture of
The reaction was carried out for 12 hours while heating at 180-200°C. The reaction was carried out while removing the water produced from the system.
Next, this reaction mixture was dissolved in methyl isobutyl ketone, washed with water to remove the catalyst, methyl isobutyl ketone was removed under reduced pressure with an aspirator, and then the temperature was gradually increased from 100°C to 250°C under reduced pressure to 0.1 mmHg. During this time, unreacted α-naphthol and salicylaldehyde were distilled off. Thus, 155 parts of novolac type naphthol resin were obtained. The melting point is 260℃, and the molecular weight determined by the freezing point depression method after dissolving in dioxane is 700 (the molecule contains 3.2 naphthol components and 2.2 salicylaldehyde components, and 5.4 hydroxyl groups).
). Next, Reference Example 1 was prepared, except that 1100 parts of epichlorohydrin, 1.8 parts of trimethylbenzylammonium chloride, and 104 parts of a 50% caustic soda aqueous solution were used for 150 parts of this novolac type naphthol resin.
In the same manner as above, 165 parts of the desired polyglycidyl ether was obtained. The polyglycidyl ether obtained here has a melting point of
Epoxy equivalent determined by hydrochloric acid dioxane method at 140℃
300 (g/equivalent), and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 1000. Examples 1 to 4, Comparative Example 1 20 parts each of the polyglycidyl ethers of Reference Examples 1 to 4 were dissolved in 30 parts of acetone, and 4,4'-diaminodiphenylsulfone was combined with the 4,4'-epoxy group contained in the polyglycidyl ether. '-Diamino diphenyl sulfone was added in an equimolar amount of active hydrogen atoms to make a homogeneous solution, and after evaporating the acetone at 80°C, it was molded using a press molding machine under a pressure of 10 kg/cm ² for 200 min using a conventional method. A curing reaction was performed at ℃ for 1 hour to obtain a molded piece having a thickness of 3 mm, a width of 6 mm, and a length of 120 mm. This molded piece
After curing at 220°C for 4 hours, the temperature was raised using DMA (DuPont model 1090) at a rate of 10°C per minute to determine the glass transition temperature. On the other hand, this resin was boiled in water at 100°C for 10 days and its water absorption rate was determined. For comparison, 6.2 parts of 4,4'-diaminodiphenyl sulfone and 30 parts of acene were added to 17.5 parts of diglycidyl ether of bisphenol A (epoxy equivalent: 175 (g/equivalent)), and the same procedure as in Examples 1 to 4 was carried out. The glass transition temperature and water absorption of the resulting resin were determined. The following results are shown in Table 1. The cured product of the polyglycidyl ether of the present invention has good heat resistance and low water absorption.

[Table] Examples 5 to 6 The performance of the resins obtained by curing the polyglycidyl ethers obtained in Reference Examples 1 to 2 using dicyandiamide as a curing agent instead of diaminodiphenylsulfone is shown. Dissolve the specified amount of polyglycidyl ether and 2 parts of dicyandiamide in 70 parts of methyl cellosolve,
After distilling off the methyl cellosolve under reduced pressure at ℃, it was transferred to a press molding machine and press-molded for 60 minutes at 200℃ under a pressure of 10 kg/cm ³ to a thickness of 3 mm, width of 6 mm, and length.
A molded piece of 120 mm was obtained. The resin obtained here was heated at 200℃.
After curing for 24 hours, the glass transition temperature and water absorption were determined. The results are shown in Table 2.

[Table] Reference Example 5 1680 parts of methyl epichlorohydrin was added to 200 parts of the novolac-type naphthol resin made from α-naphthol and p-oxybenzaldehyde obtained in Reference Example 1.
Trimethylbenzylammonium chloride
2.5 parts were added and heated at 110-120°C for 3 hours, and then 135 parts of a 50% aqueous solution of caustic soda was added over 2 hours while heating to 80°C under reduced pressure. During this time, water was removed from the system by azeotropy between water and methylepichlorohydrin. The temperature was maintained for an additional 2 hours, and water was removed from the system. After the reaction is complete, methyl epichlorohydrin is distilled off under reduced pressure, extracted with methyl isobutyl ketone, washed with water to remove caustic soda and sodium chloride, washed with an aqueous phosphoric acid solution, and then washed with water until the methyl isobutyl ketone solution becomes neutral. Finally, methyl isobutyl ketone was removed under reduced pressure to obtain 258 parts of the desired polyglycidyl ether. The polyglycidyl ether obtained here has a melting point of
The epoxy equivalent determined by the hydrochloric acid dioxane method at 98℃ is
255 (g/equivalent), and the molecular weight determined by the freezing point depression method after dissolving in dioxane was 860. Example 7 20 parts of the polyglycidyl ether of Reference Example 5 was dissolved in 30 parts of acetone, and 4.9 parts of 4,4'-diaminodiphenyl sulfone (epoxy group contained in the polyglycidyl ether and 4,4'-diaminodiphenyl) was dissolved in 30 parts of acetone. A homogeneous solution was obtained by adding sulfone (an amount equivalent to an equimolar amount of active hydrogen atoms), the acetone was evaporated at 80°C, and the mixture was cured in a conventional manner using a press molding machine to obtain a molded resin. The glass transition temperature (DMA method) of this cured product was 280°C, and the water absorption after immersion in boiling water at 100°C for 10 days was 3.2%. That is, it was confirmed that the cured product of polyglycidyl ether according to the present invention has good heat resistance and low water absorption. Reference Example 6 144 parts of α-naphthol and 94 parts of p-chlorobenzaldehyde were heated and melted at 130°C, and 36%
0.2 parts of hydrochloric acid and 0.3 parts of p-toluenesulfonic acid were added, and heating and post-treatment were carried out in the same manner as in Reference Example 1 to obtain 218 parts of novolak-type naphthol resin. The melting point of the obtained novolac type naphthol resin is
The molecular weight determined by the freezing point depression method after dissolving in dioxane at 300 DEG C. was 580 (the molecule contains an average of 2.65 naphthol components and an average of 1.65 p-chlorobenzaldehyde components). Next, this novolac type naphthol resin 200
1,340 parts of epichlorohydrin and 2.5 parts of trimethylbenzylammonium chloride were added to the mixture, and the mixture was heated under reduced pressure in the same manner as in Reference Example 1 to carry out a glycidylation reaction. The polyglycidyl ether thus obtained had a melting point of 145°C and was determined by the hydrochloric acid dioxane method. The epoxy equivalent was 350 (g/equivalent), and the molecular weight determined by the coagulation descent method after dissolving in dioxane was 760. Example 8 20 parts of the polyglycidyl ether obtained in Reference Example 6 was dissolved in 30 parts of acetone, 3.5 parts of 4,4'-diaminodiphenylsulfone was added to make a homogeneous solution, and after evaporating the acetone, the mixture was dissolved in a conventional manner. A cured resin was obtained by press molding. The glass transition temperature (DMA method) of this cured resin is
After being immersed in boiling water at 290℃ and 100℃ for 10 days, the water absorption rate was 2.6%, demonstrating good heat resistance and water resistance.

[Brief explanation of the drawing]

1 to 6 are infrared absorption spectra of novolak-type naphthol and polyglycidyl ether obtained in Examples.

Claims (1)

[Claims] 1. Polyglycidyl ether represented by the following formula () [However, G represents [Formula] or [Formula], and R ₁ represents a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. However, when R ₁ represents an aromatic hydrocarbon group which may be substituted with a halogen atom, the hydrogen atom in R ₁ may be further substituted with a group -OG. n represents an integer of 1 to 8 when R ₁ does not have a -OG substituent,
When R ₁ has a substituent -OG, 0 or 1 to
Represents an integer of 4. ] The following formula (') is obtained by curing with an epoxy curing agent containing active hydrogen. [However, G′ is at least partially expressed by the following formula Alternatively, it represents a group represented by the formula, the rest being the same as G, and Z is an epoxy curing agent residue having active hydrogen. R ₁ ′ is R ₁
or, when R ₁ has a -OG substituent, a part thereof is converted to -OG'.
n is as defined above. ] It mainly consists of bonding units represented by
Epoxy cured resin that is less than 0.4.