JPS62524A - Curable unsaturated alkyd and its production - Google Patents

Abstract

PURPOSE:To obtain an unsaturated alkyd resin excellent in workability, water resistance and chemical resistance, by reacting an epoxy resin with a specified amount of cresol and esterifying the hydroxyl groups of this product with an alpha,beta-unsaturated polybasic acid. CONSTITUTION:An epoxy resin of formula I is reacted with cresol in an amount sufficient to eliminate the epoxy groups of this epoxy resin to form a reaction product of formula II. The hydroxyl groups of this reaction product are esterified with an alpha,beta-unsaturated polybasic acid or its anhydride to obtain the purpose unsaturated alkyd of formula III. In the formulae, R1 and R2 are each H or methyl, n is 0-2 and m is 2-20. Because said unsaturated alkyd has methylphenoxymethylene groups as side chains, it is bulky and is low in a content of double bonds per unit MW, which will advantageously affect the boiling water resistance and heat distortion temperature of the resin.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a radically curable unsaturated alkylar r having a novel structure useful for various uses such as paints, adhesives, molding materials, and FRP, and a method for producing the same. .

[Conventional technology]

Currently, unsaturated polyester resins and vinyl ester resins are widely used as u/nocal curing resins that can be cured at room temperature.

However, as the uses of resins become more diverse, the performance required of the resins becomes more detailed and sophisticated, and it is often felt that existing resins are insufficient to meet these requirements. For example, in the case of gel coat, which is commonly used as a coloring and surface protection layer for FRP, there is a movement toward increasing the level of water resistance, alkali resistance, and corrosion resistance against specific chemicals without increasing costs.

Vinyl ester resin has excellent water and chemical resistance, so it is natural that it could be used in this way, and in fact, its boiling resistance itself is extremely good, so it is commonly used as a dull coat. . However, there is a need for further improvements in the workability required for Dullcoat, such as suitability for graying, thixotropy, and no color separation, and in response to these expectations, efforts for improvement continue. However, the desired results have not been achieved at this stage.

On the other hand, as for unsaturated polyester resin, -[CH] of bisphenol type polyester represented by the following formula.

Styrene M liquid is popular for its good workability and has become the mainstream of Dullcoat for bathtubs. However, it has the drawback that its hot water resistance is inferior to that of vinyl ester resins, and it does not meet high demands.

[Problem that the invention seeks to solve]

As a result of intensive research aimed at improving the various drawbacks of these existing resins, the present inventors discovered that an unsaturated alkyd with a new structure represented by the following general formula was found to be at least as good as these existing resins in terms of water resistance and chemical resistance. The present inventors have discovered that they have the same or better properties and are also superior in workability, and have completed the present invention.

[Failure to solve the problem]

That is, the present invention provides a curable inorganic compound represented by the general formula % (where R and R2Fi each represent hydrogen or a methyl group, n is 0 to 2, and m is an integer of 2 to 20). is to provide saturated alkyd.

Furthermore, in the present invention, an epoxy resin represented by the general formula %) is reacted with cresol in an amount such that the epoxy groups in the epoxy resin disappear to generate a reaction product [■] (hereinafter referred to as the blank). After that, the hydroxyl group in the reaction product (1) is
-Providing a method for producing a curable unsaturated alkyd represented by the general formula %, characterized by esterification with a β-unsaturated polybasic acid or anhydride thereof [provided that R1*R2e n and m are the same as above].

[Effect]

The unsaturated alkyd of the present invention has a novel structure represented by the above general formula, and has a methylphenooxymethylene group in the side chain, so it is bulky and has fewer double bonds per molecular weight. It is estimated that this has a favorable effect on the boiling resistance and heat distortion temperature of the resin. In addition, since the main chain of the unsaturated alkyd of the present invention is composed of repeating units in which bisphenol diglycidyl ether and α-β unsaturated polybasic acid are ester bonded, it can be used as a styrene bath liquid like bisphenol type polyester. It is thought that it will have excellent workability when used. The number of repeating units is 2 to 20 (equivalent to about 10,000 to 10,000 in terms of molecular weight), and if the number of repeating units is smaller than 2, the curing properties of the resin will be poor; if the number is larger than 20, it will be difficult to carry out the present invention. Become.

The unsaturated alkyd according to the present invention can be used in paints, adhesives, It can be used for various purposes such as molding materials and FRP.

The method for synthesizing the unsaturated alkyd of the present invention is to react V sol with a bisphenol diglycidyl ether type epoxy resin, and then convert the hydroxyl group in the reaction product [■] into an α-β unsaturated polybasic acid or its An example is a method of esterification with an anhydride. The flow is shown below using a typical example.

(The following is a blank space) Box 1. The epoxy resin used in the present invention is of the phenyl glycidyl ether type, commonly referred to as the so-called bisphenol type.

For example, the type shown by the following general formula synthesized from bisphenol A and epichlorohydrin (white space below). do not have to.

Furthermore, a methylene-bisphenylglycyl ether type epoxy resin commonly referred to as a bisphenol F type epoxy resin can also be used.

Examples of the cresol to be reacted with the epoxy resin include ortho-cresol, meta-cresol, and m-cresol.

In the present invention, mixtures of these can also be suitably used.

The reaction ratio of epoxy resin and Kunzol is 0.5 or less, 1 equivalent of phenolic hydroxyl group per 1 equivalent of epoxy group.
An equivalent amount or more is appropriate.

If the amount is less than 0.5 equivalent, it is not preferable because it tends to be calcified during esterification with an unsaturated polybasic acid or its acid anhydride.

During the reaction, tertiary amines that are generally used as curing accelerators for epoxy resins, such as benzyldimethylamine, tris(dimethylamino)phenol, or quaternary amines, are used.
The use of grade ammonium salts and the like is an obvious advantage in terms of promoting the reaction.

Examples of the α-β unsaturated polybasic acid or its acid anhydride used in the present invention include maleic anhydride, maleic acid, and fumaric acid. At that time, it can also be modified with a small amount of saturated polybasic acid.

Esterification is carried out in the usual manner, i.e. in an inert gas stream at 1,80
It is carried out at a temperature of about 220°C.

The unsaturated alkyds obtained by esterification are styrene, vinyltoluene, and sialyl phthalate.

It can be dissolved in copolymerizable monomers such as diallyltenphthalate, methacrylic acid esters, etc., and provided for various uses.

At this time, in order to prevent gluing, a small amount of commonly used polymerization inhibitors such as polyhydric phenols and quinones (
0.01-0.5 phr) must be added.

It goes without saying that fillers, reinforcing materials, colorants, mold release agents, polymers, etc. can be used in combination, depending on the needs of the application.

〔Example〕

Next, examples will be shown below to help understand the present invention. In the examples, parts indicate parts by weight.

Example 1 In an IL Seno-e rubble flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube, as an epoxy resin,
370g of Epicote 827 from Yuka Shell Co., Ltd., 195g of para-cresol (ratio of epoxy group to phenolic hydroxyl group is 1:Q, 9), and 1.5g of benzyldimethylamine are charged and heated. Since it generates heat, it was cooled to prevent it from rising above 160°C.

When the reaction was then carried out at 150 to 160° C. for 5 hours, infrared analysis showed that the free epoxy groups had completely disappeared (see Figure 1).

Next, add 110 g of fumaric acid and add 200 g of fumaric acid to
When heated to 10°C for 6 hours, the acid value became 19.6, so 0.13p of hydroquinone was added and poured into a metal vat to solidify. An unsaturated alkyd (4) of a yellowish brown color and a melting point of about 110-115°C was obtained. Figure 2 shows the infrared absorption spectrum. The average molecular weight was approximately 3200.

Grind 100 parts of unsaturated alkyd (A), add 100 parts of styrene to it, and heat and stir at 60-70°C to obtain unsaturated polyester resin (), which has a donor color number of 2-3 and a viscosity of 9.6 poise. Obtained with.

A system in which 100 parts of unsaturated polyester resin CB), 2 parts of methyl ethyl ketone mother oxide, and 2 parts of cobalt naphthenate were added was heated in 49 minutes, and the maximum temperature reached 139° C. while gently generating heat.

The heat distortion temperature of the cast product was 108°C.

As a result of a continuous boiling test performed on a casting plate with a thickness of 5α×5 cm p and a thickness of 3 m, no abnormality in appearance was observed even after 2000 hours of boiling, indicating excellent water resistance.

Further, in a continuous boiling test using a 10% caustic soda aqueous solution, no abnormality was observed for up to 500 hours, and similarly, extremely good alkali resistance was exhibited.

Example 2 In a 1t cenosolable flask equipped with a stirrer, a fractionating condenser 1, a gas inlet pipe, and a thermometer, a bisphenol F type epoxy resin, Epicoat 807 manufactured by Yuka Shell Co., Ltd.
, 173 g of metacresol (ratio of epoxy group to phenolic hydroxyl group is 1:0.8), and 1.5 g of trimethylbenzyl ammonium chloride, and when heated, heat begins to heat rapidly after the temperature exceeds 110°C, so cool it. The temperature was kept below 160°C. 150-160
When kept at ℃ for 5 hours, free epoxy groups completely disappeared as a result of infrared analysis.

Next, add 98 g of maleic anhydride and heat at 200-215°C.
After 6 hours of esterification in an inert gas stream, the acid value was 11.
4, 0.1 g of hydroquinone was added, poured into a metal vat, and solidified.

Unsaturated alkyd (yellow brown, melting point approximately 105-110℃)
C) was obtained. The average molecular weight was about 4,500.

The unsaturated polyester resin obtained by crushing 100 parts of unsaturated alkyd (C) and dissolving it in 110 parts of p-methylstyrene while heating at 60 to 70°C has a Hazen color number of 500 and a viscosity of 9.5. It was Poise.

0) 100 parts of unsaturated polyester resin, 2 parts of methyl ethyl ketone oxide, and naphthenic acid co/? route 1
The system containing 0.2 parts of trimethylaniline slowly generates heat after gluing in about 40 minutes at room temperature, and the maximum exothermic temperature is 1 part.
The temperature reached 49°C.

The heat distortion temperature of the cast product was 104°C.

[Brief explanation of drawings]

FIG. 1 shows the infrared spectrum of the reaction product of the epoxy resin obtained in Example 1 and Gurafresol. FIG. 2 shows an infrared spectrum of the unsaturated alkyd of the present invention obtained by reacting the above reaction product with fumaric acid.

Claims (1)

[Claims] (1) Curable unsaturated alkyd substantially represented by the following general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, R_1 and R_2 each represent hydrogen or a methyl group, and n is 0 to 2. , m is an integer from 2 to 20]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼The epoxy resin represented by is reacted with cresol in an amount that eliminates the epoxy groups in the epoxy resin, and the reaction product [I] ▲There are mathematical formulas, chemical formulas, tables, etc. After producing ▼, the hydroxyl group in the reaction product [I] is esterified with an α-β unsaturated polybasic acid or its anhydride, the general formula ▲ mathematical formula, chemical formula, table, etc. There is a method for producing a curable unsaturated alkyd represented by ▼ (where R_1, R_2, n and m are the same as above).