JPS5898328A - Production of epoxy resin - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin excellent in flame resistance, flexibility, softness, adhesiveness, etc., by adding a carboxylic acid to a bromine-containing epoxy resin prepared from tetrabromobisphenol A and epichlorohydrin. CONSTITUTION:Tetrabromobisphenol A or a mixture of tetrabromobisphenol A and bisphenol A is reacted with epichlorohydrin to prepare a bromine-containing epoxy resin, bromine content about 16-51wt%. Then, about 0.1-0.8g eq. of a saturated or unsaturated carboxylic acid represented by the formula, wherein R is a 7-20C alkyl or alkenyl and n is 1-8, is added to 1g eq. of the above- produced epoxy resin to obtain the purpose epoxy resin. As examples of the carboxylic acid of the formula, there can be mentioned heptanoic acid, sebacic acid, linoleic acid and palmitic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel epoxy resin characterized by adding carboxylic acids to a bromine-containing epoxy resin.

Conventionally, epoxy resins have been widely used in paints, electricity, civil engineering, architecture, and adhesive applications due to their excellent mechanical, chemical, and electrical properties.

When special flame retardancy is required in these applications, bromine-containing epoxy resins are used.

In addition, when flexibility, pliability, and high adhesion are required,
A so-called flexible epoxy resin is used. Flexible epoxy resins are mainly epoxy resins with long chain sulfuric acid-carbon bonds, such as polyglycidyl ethers obtained from polyhydric alcohols such as polyethylene glycol, polypropylene glycol, and trimethylolpropane, and epichlorohydrin, lyluic acid, and Glycidyl esters obtained from higher fatty acids such as dimers and dimers,
Glycidyl ester obtained from dicarboxylic acid obtained by modifying butadiene-acrylonitrile copolymer with carboxylic acid,
Further, there are galuponic acid-modified epoxy resins obtained by adding the above carboxylic acids and epoxy resins.

For applications that require flame retardancy, flexibility, softness, and high adhesion at the same time, it is possible to use these brominated epoxy resins in combination with flexible winter poxy resins. The preparation of curing agents and curing agents is complicated, and improvements in this respect have been desired for a long time.

As a result of intensive studies to solve these problems, the present inventors found that a bromine-containing epoxy resin modified with carboxylic acid is flame retardant, flexible, pliable, and highly adhesive. This discovery led to the present invention.

The present invention provides a bromine-containing epoxy resin obtained from tetrabromohisphenol or a mixture thereof and bisphenol A and epichlorohydrin with the general formula % (%) (wherein is an alkyl group having 7 to 20 carbon atoms, or an alkyl group having 7 to 20 carbon atoms). A method for producing an epoxy resin is provided, which is characterized by adding a saturated or unsaturated carboxylic acid represented by a group (n represents 1 to 8).

The bromine-containing epoxy resin used in the method of the present invention is
It is obtained by reacting tetrabromobisphenol A or a mixture of tetrabromohisphenol and bisphenol A with epichlorohydrin in a conventional manner, and has a bromine content of 16 to 61%.

Examples of the saturated or unsaturated carboxylic acids used in the method of the present invention include heptanoic acid, capric acid, lauric acid, palmitic acid, stearic acid, rillic acid, oleic acid, and sebacic acid. These carboxylic acid modifications can be used alone or in a combination of two or more steps, and in the case of unsaturated carboxylic acids, their dimers, trimers, etc. can be used. In the method of the present invention, among these carboxylic acids, sluic acid, its dimer and/or its trimer are preferably used. These carboxylic acids are used in an amount of 0.1 to 0.8 gram equivalent, preferably 0.8 to 0.6 gram equivalent, per 1 gram equivalent of the bromine-containing epoxy resin.

When the amount of carboxylic acids is less than 0.1 gram equivalent, although flame retardancy can be obtained, it is difficult to obtain flexibility;
On the other hand, if the amount exceeds 0.068 grams, flame retardancy and malleability can be obtained, but compatibility with other epoxy resins is poor, and reactivity and water resistance are also reduced, which is not preferable.

Conventionally known methods can be used to add carboxylic acids to the bromine-containing epoxy resin. For example, without a catalyst or in the presence of a catalyst such as imidazoles, tertiary amines, or quaternary ammonium salts, or in a solvent such as ketones such as methyl ethyl ketone, dioxane, dimethylformamide, etc. at 80°C to 200°C for 1 to 5 hours. The addition reaction is completed. In this case, the end point of the addition reaction is determined by the acid value of the starting carboxylic acids.

The new epoxy resin obtained in this way has properties that combine flame retardancy and removability, and is very useful industrially.7 Is the epoxy resin according to the present invention used alone? Alternatively, it can be used in combination with known epoxy resins, and plasticizers, fillers, pigments, solvents, and noodle fuels such as antimony trioxide and phosphorus compounds can be used as long as the curability and physical properties of the cured product are not adversely affected. It can be used in casting, casting, lamination, adhesion, paint, flooring, etc., using additives such as additives depending on the purpose.

Example 1 Heptane'Wk180f (1 gram equivalent) and Sumiepoxy E8B-840 (tetrabromohisphenol humanoid epoxy resin, epoxy equivalent 850 P/eQ-2 Sumitomo Chemical Co., Ltd. product) 106ON (8 gram equivalent) were mixed with 2-ethyl- 4
The reaction was carried out at 150° C. for 6 hours in the presence of 20 ppm of heptanoic acid using -methylimidazole as a catalyst to obtain 1120P, a yellow solid resin. This is called resin.

Example 2 Sebacic acid 101i (1 gram equivalent) and Sumiepoxy E8B-840105Of (8 gram equivalent) were reacted in the same manner as in Example 1 to obtain a yellow solid resin 10801i.
got '. This will be referred to as resin B.

Example 8 Sebacic acid 101? (1 gram equivalent) and Sumiepoxy EBB-840750F (2,1
(gram equivalent) to form a yellow solid resin 770? I got it. This will be referred to as resin C.

Example 4 In the same manner as in Example 1, dimer acid 290F (1 gram equivalent), which is a dimer of riluic acid, and Sumiepoxy E8B-
8401050F (8 gram equivalents) was reacted to obtain yellow solid resin 1280P. This is used as resin.

The analytical values of the resin M~D thus obtained are summarized in the St table.

Table 1 Epoxy equivalent: Hydrochloric acid-dioxane method (Epoxy Technology Association Technical Report No. 4 reference) Bromine content: Elemental analysis value Acid value Niblastic Materials Course Volume 10, Page 62 (Nikkan Kogyo) Reference Infrared characteristic absorption : JASCO Corporation ■ Application example 1 using infrared spectrophotometer needle Resin M~D obtained in Examples 1 to 4 and Sumiepoxy E8B-600 (bromine content 18%, epoxy equivalent 490F/6, Sumitomo Chemical) as a comparative example A varnish having the composition shown in Table 2 was prepared using

II2 Each varnish shown in Table 2 was applied to a cold compressed steel plate to a thickness of 50μ (wet form, [11)t, 160°C/60
After hardening by baking for a minute, the physical properties of the coating film were measured, and the results shown in Table 8 were obtained.

Application Example 2 Using Resin D obtained in Examples 1 to 4 and Sumiepoxy E8A-011 (bisphenol-type epoxy resin, epoxy equivalent 480 f/6q, Sumitomo Chemical Co., Ltd.) as a comparative example, 1 [shown in Table 4] was used. Created a composition varnish. Each of these varnishes was impregnated into a plain-woven glass cloth (Kanebo Stevens Co., Ltd. product [8-1600), and after drying in the night air, it was treated at 80° C. for 20 minutes to obtain a prepreg. Six sheets of the thus obtained prepreg were stacked at 160°C and under a pressure of 100#
/ Press lamination was carried out in Country 2 for 80 minutes to obtain a laminate with a thickness of approximately 1 wt. The physical properties of this laminate were measured in accordance with JI80-6484. The results are also shown in Table 4.

Claims (1)

[Scope of Claims] An epoxy resin containing tetrabromobisphenol or a mixture thereof with bisphenol A and epichlorohydrin having the general formula %) (wherein R is an alkyl or alkenyl group having 7 to 20 carbon atoms) , n represents 1 to 8).