JPS6138732B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for producing a quinazolone ring-containing epoxy resin. The epoxy resin obtained by the present invention can be cured using a curing agent having a group reactive with epoxy groups, and is suitable for use in applications such as casting, lamination, and painting, and is particularly excellent. It has the characteristics of maintaining high heat resistance, mechanical and electrical properties. Generally, epoxy resins obtained by condensation of polyhydric phenols such as bisphenol A and epihalogenhydrins such as epichlorohydrin are cured to have functional groups that react with epoxy groups such as amino groups, carboxyl groups, and carboxylic acid anhydrides. It is widely practiced in the art to obtain a resinous product (cured product) by mixing the epoxy group with a resin and reacting the epoxy group with these functional groups. However, although these cured products have excellent electrical properties, dimensional stability, chemical resistance, etc., they cannot necessarily be said to have sufficient heat resistance. The epoxy resin obtained by the present invention has excellent thermal stability, and despite the introduction of an aromatic heterocycle, it is compatible with commonly known curing agents and can be easily formed into curable compositions. The feature is that it obtains the following. In general, the introduction of aromatic heterocycles into polymers causes a significant decrease in reactivity due to higher melting points, less solubility, etc., and has been considered unsuitable for the production of epoxy compounds. However, as a result of extensive studies, the present inventors have discovered a method for obtaining an aromatic heterocycle-containing epoxy resin by introducing a quinazolone ring-containing derivative, and have completed the present invention. That is, the present invention provides the general formula (In the formula, the OH group represents one substituted at the o, m, or p position, and R represents a divalent organic group such as an alkylene group, arylene group, or aralkylene group.) The quinazolone obtained by the method of the present invention is characterized by reacting a bisphenol compound having two quinazolone rings therein with an epoxy compound having at least two or more epoxy groups in one molecule. The ring-containing epoxy resin is well compatible with curing agents such as amino groups, carboxyl groups, and carboxylic acid anhydrides, and has particularly excellent heat resistance when mixed and cured. In general, derivatives containing imide rings and other aromatic heterocycles are poorly soluble, and conventionally it has been difficult to introduce aromatic heterocycles into epoxy resins. Phenol is highly reactive with epoxy compounds and has excellent compatibility with epoxy compounds, and the production method of the present invention can produce phenols with excellent heat resistance.
A quinazolone ring-containing epoxy resin can be easily obtained. The quinazolone ring-containing bisphenol compound represented by the general formula used in the present invention is obtained by reacting, for example, anthranilic acid with malonic acid chloride or terephthalic acid chloride, and then
Bisoxazinone represented by the following general formula that can be easily obtained by dehydration ring closure. (In the formula, R is an alkylene group such as -CH ₂ -, -C ₂ H ₄ -, -C ₃ H ₆ -,

【formula】

【formula】

【formula】

【formula】

A divalent organic group selected from arylene groups such as [formula] and aralkylene groups is used as a starting material, and 1 mole of this and p-aminophenol (the same applies to o-form and m-form) are used as starting materials. 2 moles of aminophenol such as m
-Cresol, N-methyl 2-pyrrolidone, N・N
-120 with organic solvents such as dimethylacetamide
It can be easily obtained by heating at ~220°C for 3 to 10 hours. Note that when a dehydrating agent such as phosphorus pentoxide is used as a reaction catalyst, the reaction can be completed quickly without side reactions. The epoxy compound used in the present invention is
Cyclic epoxy group in the molecule,

【formula】 Or linear epoxy group

It has at least two formulas. That is, a compound containing a 1,2-epoxy group inside,
Contains epoxidized diolefins, dienes, cyclic dienes, diolefinic unsaturated carboxylic acid esters, and is commercially available as a commercially available product.
221, CY-201, CY-206, CY-269 (all Chitsuso product names) Araldite CY-179, CY-178,
These are known as -182, -185, and -175 (all product names of Ciba Corporation). In addition, compounds having a chain epoxide group include polyglycidyl ether, polyglycidyl ester, etc., and the commercially available product of the former is Epicoat.
There are 828 (product name of Ciel Corporation) DER431 and DER-438 (product name of Dow Corporation), and the latter's product names include Araldite CY-183 (product name of Ciba Corporation) and Epicote.
190, 191 (Ciel product name), Rexam X
-100 (trade name of Bayer Co., Ltd.), Epiclon 400 (trade name of Dainippon Ink Chemical Co., Ltd.), etc., but many more are known. In the present invention, the target quinazolone ring-containing epoxy resin is produced by reacting any one or more of the epoxy compounds with any one or more quinazolone ring-containing bisphenols represented by the general formula above. be able to. Here, the number of epoxy groups in the epoxy compound is 2 to 2 to the number of hydroxyl groups in the quinazolone ring-containing bisphenol.
Good results can be obtained by selecting the number within the range of 30 (preferably within the range of 4 to 20) and carrying out the reaction. If the reaction is carried out when the number of epoxy groups in the epoxy compound is less than 2 compared to the number of hydroxyl groups in the quinazolone ring-containing bisphenol, the viscosity of the reaction system will increase too much, and the compatibility will also decrease, resulting in a significant decrease in workability. In some cases, gelation may occur during the reaction. On the other hand, if the reaction is carried out at a temperature of 30 or more, the compatibility is improved, but the heat resistance of the obtained quinazolone ring-containing epoxy resin is not significantly improved and is not suitable. The reaction can advantageously be carried out by heating the formulation at a temperature between 80 and 240°C, more preferably at a temperature between 130 and 200°C. The reaction proceeds satisfactorily without a catalyst, but in order to start the reaction more easily, a small amount of aliphatic tertiary amine that does not contain active hydrogen, or a small amount of potassium carbonate, sodium carbonate, etc. may be added. Even if these are used, the effects of the present invention will not be diminished in the slightest. In addition, an appropriate amount of N・N-dimethylacetamide,
It is also possible to use organic polar solvents such as N-methyl 2-pyrrolidone as reaction medium. The quinazolone ring-containing epoxy resin obtained by the above procedure is well compatible with commonly known curing agents, and the cured product has good electrical properties, dimensional stability,
It has excellent chemical resistance, improved heat resistance, and improved mechanical properties, and can be widely used as a material that particularly requires excellent heat resistance, mechanical and electrical properties. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Bisquinazolone phenol 244g (1.0
Epicote 828 with hydroxyl equivalent) and epoxy equivalent of 190
760g (4.0 epoxy equivalent) were mixed and reacted at 180°C for 1 hour. The reaction product was a solid resin at room temperature, and maintained fluidity when heated to 60-70°C. Its epoxy equivalent weight was 360. By analyzing the infrared absorption spectrum, 1660 cm ^-1 ,
Absorption based on the quinazolone ring was observed around 1590 cm ^-1 , and it was also confirmed that the absorption of phenolic hydroxyl groups around 3200 cm ^-1 was significantly reduced. This confirmed the formation of quinazolone epoxy resin. Example 2 Bisquinazolone phenol 24.4 (0.1
(hydroxyl group equivalent) and 360 g (2.0 epoxy equivalent) of DER-438, a novolak type epoxy resin with an epoxy equivalent of 180, were mixed and reacted at 180°C for 1 hour. The reaction product was a liquid resin at room temperature and had an epoxy equivalent weight of 210. Generation of quinazolone epoxy resin was confirmed in the same manner as in Example 1 by infrared absorption spectrum analysis. Example 3 Pisquinazolone phenol 275g (1.0
CY-182, 640 with hydroxyl equivalent) and epoxy equivalent of 160
g (4.0 epoxy equivalent) and reacted at 180°C for 1 hour. The reaction product is a solid resin at room temperature.
Fluidity was maintained by heating at 60-80°C. The epoxy equivalent weight of this resin was 310. Generation of quinazolone epoxy resin was confirmed in the same manner as in Example 1 by infrared absorption spectrum analysis. Example 4 32.1g of bisquinazolone phenol represented by
(0.1 hydroxyl equivalent) and Epicote 828 with an epoxy equivalent of 180, 360 g (2.0 epoxy equivalent) were mixed,
Heated at 180°C for 1 hour. The reaction product was liquid at room temperature and had an epoxy equivalent weight of 220. Generation of quinazolone epoxy resin was confirmed by infrared absorption spectrum analysis in the same manner as in Example 1. Examples 5 to 8 150 g (0.9 acid anhydride equivalent) of methyltetrahydrophthalic anhydride (MTHA) was added to 1 epoxy equivalent of the quinazolone epoxy resin obtained in Examples 1 to 4, and further added as a curing accelerator. After adding 0.5 parts by weight of benzylmethylamine (BDMA) and mixing uniformly, the mixture was cured by heating at 150°C for 8 hours and then at 200°C for 8 hours to obtain a cured product. The resulting cured resin was measured for heat loss (heating rate (10° C./min) in Tg air. The results are listed in Table 1.

【table】

Claims (1)

[Claims] 1. General formula (In the formula, the OH group represents one substituted at any of the o-, m-, and p-positions, and R represents a divalent organic group.) Two quinazolone rings in one molecule represented by A method for producing a quinazolone ring-containing epoxy resin, which comprises reacting a bisphenol compound having the following with an epoxy compound having at least two epoxy groups in one molecule. 2. The method for producing a quinazolone ring-containing epoxy resin according to claim 1, characterized in that the reaction is carried out so that the number of epoxy groups in the epoxy compound is within the range of 2 to 30 with respect to the number of hydroxyl groups in the bisphenol compound. .