JPS61285220A - Curable unsaturated alkyd and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a coating compound, etc., having water resistance, chemical resistance, and good workability, by reacting a specific epoxy resin with a specific amount of phenol and esterifying the hydroxyl group of the reaction product with an alpha,beta-unsaturated polybasic acid (anhydride). CONSTITUTION:An epoxy resin shown by the formula I is reacted with phenol in an amount (0.5-1 equivalent based on the epoxy group of phenolic hydroxyl group) to eliminate the epoxy group in the epoxy resin preferably in the presence of a curing promoter (e.g., benzyldimethylamine, etc.). Then, the hydroxyl group in the reaction product is esterified with an alpha,beta-unsaturated polybasic acid (anhydride) (e.g., fumaric acid, etc.) in an inert flow at 180-220 deg.C, to give the aimed compound shown by the formula II (n is 2-20). Addition of a small amount of a polymerization inhibitor such as hydroquinone, etc., to the compound is required to prevent gelatinization.

Description

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

[Conventional technology]

Currently, unsaturated polyester resins and vinyl ester resins are widely used as radical-curable resins that can be cured at room temperature.

However, as the uses of resins have become more diverse, the performance required of resins has become more detailed and sophisticated, and existing resins often feel insufficient to meet these requirements. For example, in the case of Dullcoat, which is commonly used as a coloring and surface protection layer for FRP, there is a movement to improve water resistance, alkali resistance, and corrosion resistance to specific chemicals without increasing costs. Since it has extremely excellent water and chemical resistance, it is natural that it can be used in this manner, and in fact, its boiling resistance itself is extremely good, so it is generally used as a gel coat. However, there is a need for further improvements in the workability required for gel coats, such as suitability for graying, thixotropy, and no color separation, and in line with these expectations, efforts for improvement continue. However, the desired results have not been achieved at this stage.

On the other hand, regarding unsaturated polyester resins, bisphenol type polyester (-OH5 styrene solution represented by the following formula) is popular for its good workability and forms the mainstream of gel coats for bathtubs. However, its heat resistance It is inferior to water-gloss vinyl ester resin, and has defects that will occur if it does not meet high-level requirements.

[Problems to be Solved by the Invention] As a result of intensive research to improve the various drawbacks of these existing resins, the present inventors have discovered that an unsaturated alkyd with a new structure represented by the general formula below is water resistant and resistant. The present inventors have discovered that this resin has chemical properties that are at least equivalent to or better than these existing resins, and that it is also superior in terms of workability, leading to the completion of the present invention.

[Means for solving problems]

That is, the present invention provides a curable unsaturated alkyd represented by the general formula % (where n is an integer from 2 to 20).

Furthermore, the present invention provides a reaction product (1) by reacting the niboxy resin represented by the general formula with an amount of phenol that eliminates the epoxy group of the epoxy resin Ml, and then producing the reaction product CI). The hydroxyl group in α
- To provide a method for producing a curable unsaturated alkyd represented by the general formula, characterized by esterification with a β-unsaturated polybasic acid or its anhydride [where n is an integer of 2 to 20] ].

[Effect]

The unsaturated alkyd of the present invention has a novel structure represented by the above general formula, has a phenoxymethylene group in the side chain, is bulky, and has a small number of double bonds per molecular weight. Therefore, it is estimated that it has a favorable influence 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 dissolved in styrene solution like bisphenol type polyester. It is thought that this product will have excellent workability when used as a tool. The repeating unit is between 2 and 20 (equivalent to about 10 to 10,000 in terms of molecular weight); if the repeating unit is smaller than 2, the curing properties of the resin will be poor; becomes difficult.

The unsaturated alkyd according to the present invention is a polymerizable monomer (hereinafter abbreviated as "mo" or "zuma") that can be copolymerized with the unsaturated bond in the molecule.
By dissolving it in water and curing it in the presence of a radical catalyst, it can be used for various purposes such as coatings, adhesives, molding materials, and FRP.

A method for synthesizing the unsaturated alkyd of the present invention is to further esterify the hydroxyl group produced by reacting a desired epoxy resin with 7 enol with an α-β unsaturated polybasic acid or its acid anhydride. It will be done.

An epoxy resin suitable for the present invention is one having the following structure and sold by Yuka Shell Co., Ltd. under the trade name YX-4000.

CH50H.

The ratio of epoxy group to phenolic hydroxyl group is 1 equivalent of phenolic hydroxyl group per 1 equivalent of epoxy group or less: 0.5
An equivalent amount or more is appropriate.

If the amount is 0.5 equivalent or less, tertiary amines generally used as curing accelerators for epoxy resins, such as benzyldimethylamine, tris(dimethylamino ) The use of phenol or quaternary ammonium salts is extremely effective in promoting the reaction.

Examples of α-β unsaturated polybasic acids or their acid anhydrides include maleic anhydride, maleic acid, and fumaric acid. It can also be modified with saturated polybasic acids.

Esterification is carried out in the usual manner, i.e. in an inert gas stream from 180 to
It is carried out at a temperature of 220°C. The unsaturated alkyd obtained by esterification can be dissolved in copolymerizable monomers such as styrene, pyrutoluene, diallyl phthalate, diallyl terephthalate, and methacrylic acid esters, and can be used for various purposes. At this time, in order to prevent dulling, a small amount of commonly used polymerization inhibitors such as polyhydric phenols and quinones I (o, o i ~
0.5 phr) must be added.

It goes without saying that fillers, reinforcing materials, coloring agents, mold release agents, /Rimmer-7, etc. can be used in combination, depending on the needs of the application.

Next, examples will be shown below to help understand the present invention.

EXAMPLE In a 117-paraple flask equipped with a stirrer, a fractional distillation condenser, a thermometer, and a gas inlet tube, YX-4000 380? , phenol x
s9y (0.g equivalent of hydroxyl group per equivalent of epoxy group), 1.5 g of benzyldimethylamine were added, and 11
Raising the temperature to around 0°C will prevent rapid damage.

After reacting at 150 to 160° C. for 5 hours, infrared analysis confirmed that the absorption of epoxy groups completely disappeared.

Next, 110y- of fumaric acid was charged and 19y-
Esterification was accelerated at 0 to 210°C, stopped at an acid value of 11.4, and hydroquinone was 0.1? In addition, it was poured into a metal vat and cooled.

The obtained unsaturated alkyd (A) had a melting point of about 120°C and a dark reddish brown color.

100 parts of unsaturated alkyd (A) having a molecular weight of approximately 5000° was ground and dissolved in 100 parts of styrene while heating at 70 to 80°C.

The obtained unsaturated I-lyester resin CB) had a viscosity of 5.8 poise and a Gardner color number of 5 to 6.

A mixture of 100 parts of unsaturated polyester (B), 2 parts of methyl ethyl ketone, 2 parts of cobalt naphthenate, and 2 parts of cobalt naphthenate became dull in 20 minutes and slowly generated heat, reaching a maximum exothermic temperature of 157°C.

The heat distortion temperature of the cast product was 121°C.

A continuous boiling test was carried out on a 5cnL x 5crIL1 casting plate with a thickness of 3m, and no abnormality in appearance was observed even after 2000 hours of boiling, demonstrating 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.

[Brief explanation of drawings]

FIG. 1 shows the infrared spectrum μ of the reaction product of the epoxy resin and phenol obtained in Example 1. 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) A curable unsaturated alkyd substantially represented by the following general formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [However, n is an integer from 2 to 20]. 2) The epoxy resin represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ is reacted with phenol in an amount that eliminates the epoxy groups in the epoxy resin, and the reaction product [I] ▲Mathematical formula, chemical formula, The general formula ▲ is characterized in that after producing ▼, the hydroxyl group in the reaction product [I] is esterified with an α-β unsaturated polybasic acid or its anhydride, There are chemical formulas, tables, etc. ▼ Manufacturing method of curable unsaturated alkyd [
However, n is an integer from 2 to 20].