JP3460892B2 - Carbonate-modified epoxy resin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbonate-modified epoxy resin and a method for producing the same. More specifically, the secondary or tertiary hydroxyl terminal of the epoxy resin,
The present invention also relates to a carbonate-modified epoxy resin obtained by ring-opening polymerization of a cyclic carbonate compound at the primary or tertiary hydroxyl group terminal of an epoxy resin modified with a lactone, and a method for producing the same.

[0002]

2. Description of the Related Art Epoxy resins, especially bisphenol A
Glycidyl ether type epoxy resins produced from and epichlorohydrin are available in various varieties ranging from liquid to high molecular weight solid resins and are used for various purposes. Low molecular weight liquids are used as adhesives, FRPs, flooring materials, etc. by using the reactivity of the epoxy groups to cure with polyamines and polyamide resins at room temperature, and heat curing with polybasic acid anhydrides. It is mainly used for electrical applications such as cast products. On the other hand, a polymer having a high molecular weight is a fragile solid resin having a melting point of 60 to 150 ° C.
Since it has a secondary or tertiary hydroxyl group in addition to the terminal epoxy group, it is used in various coating fields utilizing the reaction of the hydroxyl group. For example, epoxy esters esterified with unsaturated fatty acids are used in air-drying paints and baking paints using melamine resin as a cross-linking agent, and are further used in combination with phenol resins for coatings for cans. It is also used as an epoxy-based powder coating material, a cationic electrodeposition coating material, etc. by mixing the block isocyanate with the powder.

Thus, although epoxy resins are used for many purposes, they are hard and brittle and their hydroxyl groups are secondary or tertiary, so that they react with a crosslinking agent that reacts with hydroxyl groups. There are various drawbacks such as poor properties, high temperature required for bake-crosslinking, and poor weather resistance.

[0004]

In order to improve the reactivity of the secondary or tertiary hydroxyl group of the epoxy resin, as described in Japanese Patent Publication No. 62-1607, the secondary or epoxy resin of the epoxy resin is used. By subjecting the tertiary hydroxyl group to ring-opening polymerization of ε-caprolactone, by imparting appropriate flexibility, the secondary or tertiary hydroxyl group having poor reactivity is converted into a primary hydroxyl group, Attempts have been made to improve reactivity. Incidentally, the Japanese Patent Publication No. 62-1607 discloses that Araldite 6097, Araldite 6084,
An epoxy resin having a secondary hydroxyl group such as Araldite 6071 is added to 97-5 parts by weight of ε-caprolactone 3-9.
A technique for producing ε-caprolactone-modified epoxy resin having primary hydroxyl groups by ring-opening addition polymerization of 5 parts by weight at 100 to 200 ° C. in the presence of a titanium compound such as tetrabutyl titanate or a tin halide catalyst. Is disclosed.

The present inventors have conducted extensive studies to improve the above-mentioned drawbacks of epoxy resins, and have found that they are of the second or third grade.
As another attempt to convert the primary hydroxyl group into a primary hydroxyl group, ring-opening polymerization of a specific cyclic carbonate compound to the secondary or tertiary hydroxyl group of the epoxy resin is carried out to improve the reactivity of the hydroxyalkyl carbonate group to the epoxy resin. It has been found that a modified epoxy resin which gives a large primary hydroxyl group or is free from the fear of deterioration in water resistance is obtained. Similarly, by subjecting the primary hydroxyl group of the ε-caprolactone-modified epoxy resin obtained by the method described in JP-B-62-1607 to ring-opening polymerization of the specific cyclic carbonate compound, the flexibility of the epoxy resin is improved. It was found that a modified epoxy resin having a primary hydroxy group having a high reactivity of a hydroxyalkyl carbonate group at the terminal and having further water resistance can be obtained without impairing the property, and completed the present invention. .

[0006]

That is, the present invention is
The present invention relates to a carbonate-modified epoxy resin represented by the following general formula [1].

[0007]

[Chemical 5]

Further, the present invention is characterized in that a lactone-modified epoxy resin represented by the following general formula [2] is subjected to ring-opening polymerization in the presence of a catalyst with a cyclic carbonate compound represented by the following general formula [3]. And a method for producing the modified epoxy resin. Hereinafter, the present invention will be described in detail.

[0009]

[Chemical 6]

[0010]

[Chemical 7]

In the carbonate-modified epoxy resin of the present invention represented by the general formula [1], the halogen atom of R ² of Ph can be exemplified by chlorine atom or bromine atom, and particularly preferably bromine atom. In the formula of Z, R
_{^{a, R b, n 1,}} x 1, R 4, R 5, n 2 and x ₂ are as defined above, preferably 1 to 5 carbon atoms as the alkyl group of R ⁴ and R ^5, especially methyl Groups are preferred.
Note that n ₁ , x ₁ , n ₂ , x ₂ and n are integers, but the measured values are not necessarily integers because they are a mixture of compounds having different values.

The number of x ₁ ring-opening lactone chains constituting Z in the general formula [1] depends on the type of lactone compound used for ring-opening polymerization. For example, when ε-caprolactone is used, both R ^a and R ^b are hydrogen, the ring-opened lactone chain is represented by the following formula (2), and β-methyl-δ-valerolactone and 3-methyl-caprolactone are used. When is used, R ^a and R ^b are each hydrogen or a methyl group and are represented by formula (3) and formula (4), respectively. Similarly, 3,5,5-trimethylcaprolactone and 3,5
The ring-opened lactone chain of 3,5-trimethylcaprolactone is represented by Formula (5) and Formula (6), respectively. Since the lactone may be used alone or in combination of two or more,
In the latter case, two or more kinds of x ₁ ring-opened lactone chains are randomly bonded. A preferred ring-opened lactone chain is one that imparts a primary hydroxyl group to the end of the ring-opened lactone chain, and particularly one derived from ε-caprolactone. x ₁ is an integer of 0 to 100, preferably 0
It is -20, more preferably 0-5, and corresponds to the number of moles of the lactone compound used with respect to 1 mole of the epoxy resin having a secondary or tertiary hydroxyl group. When x ₁ is zero, it indicates a carbonate-modified epoxy resin obtained by ring-opening polymerization of a cyclic carbonate compound in an epoxy resin. x
_{When 1} exceeds 100, the obtained carbonate-modified epoxy resin becomes too soft, which is not preferable.

[0013]

[Chemical 8]

N ₂ constituting Z in the general formula [1] is 0 to
It is an integer of 4 and depends on the cyclic carbonate compound used in the method for producing the carbonate-modified epoxy resin of the present invention. The cyclic carbonate compound is represented by the above general formula [3] and includes ethylene carbonate (n ₂
= 0), propylene carbonate (n ₂ = 1 and R ⁴ and R ⁵ are both hydrogen atoms), 1,4-butanediol carbonate (n ₂ = 2, R ⁴ and R ⁵ are both hydrogen atoms) and neopentyl glycol. Carbonate (n ₂ = 1 and R ⁴
Examples of both R ⁵ and R ⁵ include a methyl group), but those derived from neopentyl glycol carbonate are particularly preferable. Neopentyl glycol carbonate itself can be synthesized in a relatively short step from raw materials that are industrially easily available, and this carbonate compound is stable in a normal state, and in the presence of various catalysts shown below. This is because it is possible to polymerize by a process that can be industrially realized. x ₂ is an integer of 1 to 100, preferably 1 to 20, more preferably 1 to 5, and a cyclic carbonate compound used for 1 mol of an epoxy resin having a secondary or tertiary hydroxyl group. Or the cyclic carbonate compound used per 1 mol of the lactone-modified epoxy resin. One kind of cyclic carbonate compound may be used or two or more kinds thereof may be mixed and used. In the latter case, x ₂ ring-opening carbonate chains form two or more different kinds of random bonded ones. . When x ₂ exceeds 100, the epoxy content in the obtained carbonate-modified epoxy resin becomes small, and the reactivity during curing of the carbonate-modified epoxy resin decreases, which is not preferable. On the other hand, when x ₂ is less than 1, the effect of improving reactivity and the effect of improving water resistance cannot be imparted.

It is essential that n is an integer of 1 or more, but preferably 1 to 100, more preferably 1 to 50.
Is. When n is 100 or more, the viscosity is remarkably increased, and the solubility of the carbonate-modified epoxy resin in a solvent is deteriorated, which is not preferable. Incidentally, n Z's may be the same or different from each other, and in the case of the latter, there are those having different ring-opened lactone chains or ring-opened carbonate chains, and those having different numbers of x ₁ and x _2. I don't mind.

In the general formula [1], the preferred carbonate-modified epoxy resin produced by using the most common raw materials is that R ² and R ³ are hydrogen atoms, R ^a and R ^b are both hydrogen, and R ⁴ and R ⁵ are both methyl groups, and n ₁
Is 5 and n ₂ is 1.

Next, a method for producing the carbonate-modified epoxy resin of the present invention will be described. As a raw material of the carbonate-modified epoxy resin represented by the general formula [1] of the present invention, an epoxy resin having a secondary or tertiary hydroxyl group represented by the above general formula [2] or a primary to tertiary class A lactone-modified epoxy resin having a hydroxyl group is used. The former bisphenol type epoxy resin, which is an epoxy resin having a secondary or tertiary hydroxyl group, is represented by the general formula [2] Z ₁
In the above, x ₁ is 0. This is the reaction of phenol or halogen-substituted phenol such as 2,6-dihalobisphenol with aldehydes or ketones such as formaldehyde, acetaldehyde, acetone, acetophenone, cyclohexanone and epichlorohydrin or β-methylepichlorohydrin. Obtained by reacting.

Examples of the bisphenol type epoxy resin which is an epoxy resin having a secondary or tertiary hydroxyl group include those produced from bisphenol A and epichlorohydrin {formula (7)}, bisphenol A and β-.
Those manufactured from methyl epichlorohydrin {Formula (8)}, which are typically known as "Araldite (trade name)" manufactured by Ciba-Geigy Japan and "Epicoat (trade name)" series manufactured by Shell Chemical . Furthermore, the thing represented by Formula (9) which is a glycidyl ether epoxy resin manufactured from bisphenol F and (beta) -methyl epichlorohydrin is illustrated.

[0019]

[Chemical 9]

In Z ₁ of the general formula [2], x ₁ is 1
In the case of -100, it is a lactone-modified epoxy resin.
The lactone-modified epoxy resin is obtained by a known method described in JP-B-62-1607, and is obtained by ring-opening polymerization of a lactone with an epoxy resin having a secondary or tertiary hydroxyl group. . The ratio of the ring-opening lactone structure in the lactone-modified epoxy resin is x ₁
And x ₁ is an integer from ₁ to 100, as described above,
It is preferably an integer adjusted to 1 to 20, more preferably an integer adjusted to 1 to 5. Incidentally, the description of the Z ₁ in the general formula [2] R ^a, R ^b, for n _1, x ₁ is identical to that described in Z of the general formula [1].
In addition to the epoxy resin having a secondary hydroxyl group used in the present invention, a glycidyl ester epoxy resin obtained from dicarboxylic acid and epichlorohydrin (formula (10)), an alicyclic epoxy resin (formula ( 11)} can also be used.

[0021]

[Chemical 10]

The cyclic carbonate compound to be reacted with each hydroxyl group of the epoxy resin having a secondary or tertiary hydroxyl group or the lactone-modified epoxy resin having a primary to tertiary hydroxyl group is, for example, Japanese Patent Publication No. 56356/1990.
As can be seen in the publication, it can be obtained by heating and reducing the pressure with glycol and dialkyl carbonate in the presence of a basic catalyst to depolymerize the by-produced polymer. Alternatively, it can be synthesized by the reaction of alkylene oxide and carbon dioxide gas. Preferred cyclic carbonate compounds are as described above.

The proportion of the epoxy resin in the cyclic carbonate-modified epoxy resin represented by the general formula [1] of the present invention is adjusted so that x ₂ is an integer of 1 to 100, preferably 1 to 20. To do. The reason is that if the amount exceeds 100 and is too large, the reactivity is not improved due to the decrease in the primary hydroxyl group content.

Ring-opening polymerization of a cyclic carbonate to a hydroxyl group of an epoxy resin having a secondary or tertiary hydroxyl group or a lactone-modified epoxy resin having a primary or tertiary hydroxyl group is carried out at room temperature to 180 ° C., preferably 60 ℃ ~
Perform at 140 ° C. When it is lower than room temperature, the reaction rate is low, and when it is higher than 180 ° C., it is not preferable because it involves side reactions such as decarboxylation from carbonate bond.

A catalyst is preferably used in this reaction. As the catalyst, a strongly acidic ion exchange resin such as Amberlyst 15, hydrogen fluoride, hydrogen chloride, hydrogen bromide, sulfuric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, trifluoroacetic acid. Bronsted acids such as romethanesulfonic acid are mentioned. Further, examples of the Bronsted acid anion onium salt include nitrogen, sulfur, phosphorus or iodo onium salts. Below are some typical examples.

(Quaternary ammonium salt type compound) N, N-dimethyl-N-benzylanilinium antimony hexafluoride, N, N-diethyl-N-benzylanilinium boron tetrafluoride, N, N-diethyl-N-benzylpyridinium hexafluoride Antimony, N, N-diethyl-N-benzylpyridinium trifluoromethanesulfonic acid, N,
N-dimethyl-N- (4-methoxybenzyl) pyridinium antimony hexafluoride, N, N-diethyl-N- (4
-Methoxybenzyl) pyridinium antimony hexafluoride, N, N-diethyl-N- (4-methoxybenzyl)
Toluidinium antimony hexafluoride, N, N-dimethyl-N- (4-methoxybenzyl) toluidinium antimony hexafluoride.

(Sulfonium salt type compound) triphenylsulfonium boron tetrafluoride, triphenylsulfonium antimony hexafluoride, triphenylsulfonium arsenic hexafluoride, ADEKA CP-66 (manufactured by Asahi Denka Co., Ltd.),
ADEKA CP-77 (manufactured by Asahi Denka Co., Ltd.), Tori (4-
Methoxyphenyl) sulfonium arsenic hexafluoride, diphenyl (4-phenylthiophenyl) sulfonium arsenic hexafluoride.

(Phosphonium salt type compound) Ethyltriphenylphosphonium antimony hexafluoride, tetrabutylphosphonium antimony hexafluoride.

(Iodonium salt type compound) diphenyliodonium arsenic hexafluoride, di-4-chlorophenyliodonium arsenic hexafluoride, di-4-chromiumphenyliodonium arsenic hexafluoride, di-p-tolyliodonium arsenic hexafluoride, Phenyl (4-methoxyphenyl) iodonium arsenic hexafluoride.

The anionic components of the onium salts listed above are
For example, acetic acid, propionic acid, octanoic acid, lauric acid,
Onium substituted with aliphatic carboxylic acids such as stearic acid, aromatic carboxylic acids such as benzoic acid, aromatic sulfonic acids such as benzenesulfonic acid, toluenesulfonic acid, dodecylbenzenesulfonic acid, or anionic components such as perchloric acid. Salt may be used.

The catalyst is added in an amount of 1 ppm to 5%, preferably 500, based on the total weight of the epoxy resin or lactone-modified epoxy resin and cyclic carbonate compound.
It is about ppm to 1%. If the addition amount of the catalyst is less than 1 ppm, the polymerization reaction rate is extremely slow and has no practical meaning. On the contrary, if it is more than 5%, side reactions such as decarboxylation occur in a large amount, which is not preferable.

The reaction is carried out without solvent or with aromatic hydrocarbons such as benzene and toluene, esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl isobutyl ketone, halogenated hydrocarbons such as dichloromethane and dichloroethane, tetrahydrofuran, It can be carried out in an inert organic solvent having no active hydrogen such as ethers such as 1,4-dioxane, acetonitrile, nitrobenzene and nitromethane. The use of a solvent is preferable because it has the effect of lowering the viscosity of the reaction crude liquid in the system after completion of the reaction, and the uniformization of the system facilitates temperature control during the reaction. The amount of the inert solvent used is 5 to 5 with respect to the total weight of the epoxy resin or the lactone-modified epoxy resin and the cyclic carbonate compound.
It is 80% by weight, preferably 10 to 50% by weight. If the amount of the solvent used is more than 80% by weight, the polymerization reaction becomes slow, which is not preferable. On the contrary, if the amount of the solvent used is less than 5% by weight, the effect of decreasing the viscosity is small.

The end point of the addition reaction of the cyclic carbonate compound to the hydroxyl group of the epoxy resin having a secondary or tertiary hydroxyl group or the lactone-modified epoxy resin having a primary or tertiary hydroxyl group is traced by gas chromatography or the like. Is usually performed, and the time point when the concentration of the cyclic carbonate compound becomes 1% by weight or less is usually regarded as the end point of the reaction.
Even if a solvent is used, it is not necessary to remove it from the product depending on the application.

The cyclic carbonate-modified epoxy resin obtained by the present invention has improved reactivity and can be used in applications where conventional epoxy resins are used.

[0035]

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

Example 1 A 200 ml four-necked flask equipped with an air inlet tube, a thermometer, a cooling tube, and a stirrer was charged with 70 g of Araldite 6071 (manufactured by Ciba-Geigy) of bisphenol A type epoxy resin and dimethyltri. 30 g of methylene carbonate (also known as neopentyl glycol carbonate), 8.9 g of toluene as a solvent, and 0.1 g of pyridinium p-toluenesulfonic acid as a catalyst were added, and the mixture was reacted for 9 hours under N ₂ atmosphere. When the reaction was traced by gas chromatography, the reaction rate of dimethyltrimethylene carbonate was 47.
%Met. Of ¹ H-NMR analysis of the product obtained (spectrum chart shown in FIG. 1) assignments of characteristic peaks by the (methyl by dimethyl trimethylene carbonate ring-opening) 0.89~1.03ppm; 2.71 ~ 2.
77 ppm; 2.86 to 2.92 ppm (proton derived from epoxy group); 3.29 to 3.33 ppm; 3.35
-3.38 ppm (methylene group adjacent to terminal hydroxyl group by dimethyltrimethylene carbonate ring opening); 5.3
2 to 5.48 ppm (methine proton of epoxy resin due to dimethyltrimethyl carbonate ring opening). Further, GPC analysis of the raw material Araldite 6071 and the dimethyltrimethylene carbonate ring-opening polymer (spectrum chart is shown in FIG. 2. In addition, the broken line peak in the figure shows the raw material Araldite 6071 and the solid line peak shows the product. According to the comparison of the differential molecular weight distribution curve in (1), it was observed that the dimethyltrimethylene carbonate ring-opening polymer was shifted to the high molecular region compared with the molecular weight distribution of Araldite 6071. ^{From the} results of ¹ H-NMR analysis and GPC analysis, it was confirmed that the product had a structure represented by the following formula (12).

[0037]

[Chemical 11]

Example 2 A 200 ml four-necked flask equipped with an air inlet tube, a thermometer, a cooling tube, and a stirrer was placed in a four-necked flask, and the ε-caprolactone modified product [PCL G of Araldite 6071, which is a bisphenol A type epoxy resin, was used.
-105; manufactured by Daicel Chemical Industries, Ltd.] 70 g, dimethyl trimethylene carbonate 30 g, toluene 8.9 g as a solvent, p-toluenesulfonic acid pyridinium salt 0.21 g as a catalyst, and reacted under N ₂ atmosphere for 10 hours. . When the reaction was traced by gas chromatography, the reaction rate of dimethyltrimethylene carbonate was 60%.

[0039]

INDUSTRIAL APPLICABILITY According to the present invention, the secondary or tertiary hydroxyl group having poor reactivity of the epoxy resin can be converted into the primary hydroxyl group having good reactivity by ring-opening polymerization of the cyclic carbonate compound, and water resistance Thus, a carbonate-modified epoxy resin with a small decrease in properties was obtained. Further, by ring-opening polymerization of a cyclic carbonate compound in a lactone-modified epoxy resin having a primary to tertiary hydroxyl group, a primary hydroxyl group having a large reactivity of a hydroxylalkyl carbonate group can be provided, and further weather resistance is obtained. The carbonate-modified epoxy resin provided was obtained.

[Brief description of drawings]

1 is a ¹ H-NM of the product obtained in Example 1.
It is an R spectrum chart.

FIG. 2 is a GPC spectral chart of the product obtained in Example 1.

Front page continuation (72) Inventor Shinya Yamada 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Paint Co., Ltd. (56) Reference JP-A 64-9262 (JP, A) JP-A 2-91169 (JP) , A) JP 60-186524 (JP, A) JP 5-194713 (JP, A) JP 7-196568 (JP, A) JP 62-1607 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 59/14 C09D 163/00

Claims (4)

(57) [Claims] 1. A carbon nanotube represented by the following general formula [1]:
G modified epoxy resin. [Chemical 1] 2. An epoxy resin having a secondary or tertiary hydroxyl group represented by the following general formula [2] or a lactone-modified epoxy resin having a primary or tertiary hydroxyl group is added to the following general formula [3] The method for producing a carbonate-modified epoxy resin according to claim 1, wherein the cyclic carbonate compound represented by the formula (1) is subjected to ring-opening polymerization in the presence of a catalyst. [Chemical 2] [Chemical 3] 3. The method for producing a carbonate-modified epoxy resin according to claim 2, wherein the catalyst is one selected from a Bronsted acid, an onium salt of a Bronsted acid anion, or a strongly acidic cation exchange resin (H type). 4. The method for producing a carbonate-modified epoxy resin according to claim 2, wherein the cyclic carbonate compound represented by the general formula [3] is dimethyltrimethylene carbonate represented by the following formula (1). [Chemical 4]