JPH08119955A - Epoxy-based reactive diluent - Google Patents

Abstract

PURPOSE: To obtain an epoxy-based reactive diluent, useful for various coatings, coating agents and adhesives and having high compatibility, diluting properties, a low vapor pressure and low toxicity within a wide temperature range. CONSTITUTION: This compound of the formula [(n) is an integer of 1-10], e.g. 2-ethylhexyl diglycol glycidyl ether, is obtained by adding caustic soda, etc., to an alcohol and epichlorohydrin in the presence a phase-transfer catalyst (a quaternary ammonium salt, a tetravalent phosphonium salt, etc.). Furthermore, 10-30 pts.wt. compound of the formula as a diluent can be mixed with 70-90 pts.wt. general-purpose epoxy resin such as a bisphenol A type epoxy resin and a curing agent such as an aliphatic polyamine in an amount equal to the epoxy equiv. can be blended and utilized for an adhesive, a sealing medium, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an epoxy-based reactive diluent (2-ethylhexyl n-glycol glycidyl ethers) useful for various paints, coating agents and adhesives.

[0002]

2. Description of the Related Art Alkyl glycidyl ethers have hitherto been widely used as reactive diluents for various paints, coating agents and epoxy resins for adhesives. The diluent used for these applications must be compatible with the resin, highly dilutable, have low toxicity and low vapor pressure, and should not cause deterioration in quality. For example, in the case of butyl glycidyl ether, the dilution effect is excellent, but there is a problem in terms of toxicity.
In the case of higher alcohols, there are C12 and C14 glycidyl ethers. In this case, although improvement in toxicity is recognized, there is a problem such as deterioration of low temperature dilution characteristics such as crystallization at low temperature.

[0003]

As described above, there is a demand for the development of an epoxy reactive diluent which is as low in toxicity as possible while maintaining high compatibility and dilutability in a wide temperature range. To reduce the toxicity, there is a method of increasing the molecular weight, but since compatibility and dilutability tend to decrease, it is necessary to introduce a polyoxy chain. Therefore, when ethylene oxide is added to a lower alcohol to increase the molecular weight while maintaining compatibility, there is a drawback that the water resistance is decreased. Also,
When a polyoxy chain having a long alkyl chain (polypropylene oxide, polybutylene oxide, etc.) is introduced, the dilutability may decrease. Therefore, there is a demand for development of an epoxy-based reactive diluent that solves the above problems without impairing its usefulness as a diluent.

The present invention was devised in view of the current state of the art, and its object is a novel epoxy system having high compatibility, dilutability, low vapor pressure and low toxicity in a wide temperature range. Providing a reactive diluent.

[0005]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above objects, 2-ethylhexyl n-glycol glycidyl ether has high compatibility and dilutability with various resins in a wide temperature range. The present invention has been completed on the finding that it exhibits (normal temperature and low temperature).

That is, the present invention is an epoxy compound represented by the following formula (1).

Embedded image In the formula, n represents an integer of 1 to 10.

The novel epoxy compound of the present invention solves the problem of toxicity in lower alcohol type glycidyl ether, and also improves the low temperature dilutability in higher alcohol type glycidyl ether. In particular,
Among the epoxy compounds of the above formula (1), 2-ethylhexyl diglycol glycidyl ether represented by n = 2 is most preferable. If n, which represents the number of glycol components, is too large, problems occur in water resistance and dilutability, which is not preferable.

The quality required of the diluent for the epoxy resin differs depending on the application. For general use such as paint applications, cost is a major issue. When used for electronic materials, strict quality control such as purity and chlorine content is required. As described above, the epoxy-based reactive diluent of the present invention also needs to be selected and studied by selecting a synthesis method according to the purpose and application.

Generally, the epoxy compounds of the present invention are
It can be produced by a method in which epichlorohydrin is added dropwise to an alcohol in the presence of a Lewis acid and then the ring is closed with caustic soda. In this method, since 1 mol or more of the adduct is easily formed in the epichlorohydrin addition step, the total chlorine amount becomes a high value even if the hydrolyzable chlorine can be reduced.

When a highly pure product of the epoxy compound of the present invention is required, caustic soda is added to alcohol and epichlorohydrin in the presence of a phase transfer catalyst (generally, various quaternary ammonium salts and tetravalent phosphonium salts). There is a method of adding and synthesizing. Further, when a high-purity product is required, the desired quality can be obtained by once synthesizing the high-purity product by the above method and then distilling and purifying the product.

The epoxy compound of the present invention can be used as an epoxy resin diluent in epoxy resin adhesives, paints, coating agents, sealants and the like. For example,
When the compound of the present invention is used as a diluent for an epoxy resin, 70 to 90 parts of a general-purpose epoxy resin is mixed with 10 to 30 parts of the compound of the present invention, and a curing agent of the same amount as the epoxy equivalent is added thereto. It can be cured under curing conditions depending on the type of curing agent. Examples of the general-purpose epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol or phenol / novolak type epoxy resin, and the curing agent includes amine curing agent and acid anhydride curing agent. Is mentioned. Examples of amine-based curing agents include aliphatic polyamines, aromatic polyamines and polyamide polyamines, and examples of acid anhydride-based curing agents include phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride and tetrahydrophthalic anhydride. Acid and methyl tetrahydrophthalic anhydride and the like. In addition, the curing condition when the amine curing agent is used is usually from room temperature to medium to high temperature for several hours to several days, and when the acid anhydride curing agent is used, it is from 100 to 150 ° C. for several hours to several ten. It's time.

[0012]

EXAMPLES The present invention will be described with reference to the following examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by weight".

[Synthesis Example 1] 2 parts of tin tetrachloride pentahydrate was added to 100 parts of 2-ethylhexyl diglycol to give 75 parts.
Epichlorohydrin 67 at ~ 80 ° C for about 1.5 hours
Parts were dropped. After the dropping, the mixture was aged in the same temperature range for about 2.5 hours, 46 parts of toluene was added, and 24 parts of caustic soda was gradually added at 35 to 40 ° C. over about 1.5 hours. After the addition, the mixture was aged in the same temperature range for about 5 hours. Next, 46 parts of water was added to the system, the mixture was left standing with stirring, only the upper layer was taken out, and neutralized to pH = 5 to 6 with acetic acid. After neutralization, water 2
It was washed twice with 3 parts of water, concentrated and filtered to obtain the desired product (yield 98%).

The object is mainly a composition of 60% of 2-ethylhexyldiglycol glycidyl ether in which n = 2 among the compounds of the formula (1) and 27% of the compound of the following formula (2). It was confirmed that there is.

Embedded image In the formula, n represents an integer of 1 to 10.

[Synthesis Example 2] 100 parts of 2-ethylhexyl diglycol and 109 parts of epichlorohydrin were added in the presence of 0.9 parts of a phase transfer catalyst (triethylbenzylammonium chloride), and the mixture was added at 60 to 65 ° C. for about 1.0 hour. 28 parts of caustic soda was added, and after the addition, it was aged in the same temperature range for about 2 hours. After completion of the aging, 92 parts of water was added and the mixture was allowed to stand with stirring, then only the upper layer was taken out and neutralized to pH = 5 to 6 with acetic acid. After neutralization, the product was washed twice with 27 parts of water, concentrated and filtered to obtain the desired product (yield 86%).

It was confirmed that this target product was a 95% pure product of 2-ethylhexyldiglycol glycidyl ether of n = 2 among the compounds represented by the formula (1).

[Synthesis Example 3] The target substance obtained in Synthesis Example 2 is distilled to give a boiling point of 138 to 142 ° C./1.5 mmH.
g product (82% yield) was obtained. It was confirmed that the target product was 99.5% pure 2-ethylhexyldiglycol glycidyl ether of n = 2 among the compounds represented by the formula (1).

Example 1 In a kettle dish, the compounds obtained in Synthesis Examples 1 to 3, butyl glycidyl ether, and Epolite M-1230 (C12,
13 alkyl glycidyl ether, Kyoeisha Chemical Co., Ltd.
2 g each) were accurately weighed, left for 1 hour in a blast dryer adjusted to 105 ° C., then precisely weighed, and the weight loss rate of each reactive diluent was calculated from the values before and after this. .
The results are shown in Table 1.

[0019]

Example 2 In a 100 ml glass bottle, Epicoat 827 (bisphenol A diglycidyl ether, manufactured by Yuka Shell Co., Ltd.)
And the compounds obtained in Synthesis Examples 1 to 3, butyl glycidyl ether, or Epolite M-1230 were mixed at the weight ratios shown in Table 2, and the mixture was allowed to stand in a thermostat at 25 ° C. for 2 hours, and then a B-type viscometer. Each viscosity was measured at. The results are shown in Table 2.

[0021]

Example 3 Each sample prepared in Example 2 was allowed to stand in a refrigerator at -10 ° C for 5 hours, and then its appearance was observed. The transparent liquid is represented by O and the colorless solid is represented by X. Table 3 shows the results.

[0023]

As can be seen from the results of weight loss on heating at 105 ° C. in Table 1, regarding vapor pressure characteristics, butyl glycidyl ether was almost evaporated by heating,
2-Ethylhexyl diglycol glycidyl ether (Synthesis Examples 1 to 3) evaporated only a few% equivalent to Epolite M-1230. In addition, Epicoat 82 at room temperature
The diluting effect of 2-ethylhexyl diglycol glycidyl ether (Synthesis Examples 1 to 3) on No. 7 (bisphenol A diglycidyl ether, manufactured by Yuka Shell Co., Ltd.) was Epolite M-1230, as can be seen from the results in Table 2. Although equivalent, at the low temperature, from the solubility results in Table 3, Epolite M-1230 was crystallized, whereas
Similar to butyl glycidyl ether, no crystallization was observed.

From the results of the above examples, as shown in Table 4, the novel epoxy compound of the present invention represented by the formula (1) has all the vapor pressure characteristics, the dilution effect at room temperature and the low temperature solubility. It has been found to be excellent and useful as an epoxy reactive diluent.

[0026] The vapor pressure characteristic is based on the measurement result of the heating loss at 105 ° C. In the table, “⊚” represents considerably excellent, “∘” represents excellent, and “x” represents inferior.

[0027]

Since the epoxy compound of the present invention is excellent in compatibility with resin, dilutability (normal temperature and low temperature), low toxicity and vapor pressure characteristics, it is extremely useful as a reactive diluent for epoxy resin and has a purpose. It is possible to easily synthesize a product having a quality suitable for the intended use. Further, the epoxy compound of the present invention is also useful as an intermediate raw material for various resin monomers.

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[Procedure amendment]

[Submission date] November 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

[0026]

Claims (1)

[Claims] 1. An epoxy compound represented by the following formula (1). Embedded image In the formula, n represents an integer of 1 to 10.