JPS5871917A - Low-viscosity epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain titled composition of high curing rate, with small irritating effect to man, capable of providing high-performance cured products, comprising a liquid epoxy resin and a specific alkyl glycidyl ether. CONSTITUTION:The objective composition comprising (A) a liquid epoxy resin such as 2,2-bis(4-hydroxyphenyl)-propane diglycidyl ether and (B) a >=8C alkyl glycidyl ether such as 2-ethylhexyl glycidyl ether. The weight ratio (A)/(B)= 60/40-90/10. Furthermore, said composition is characterized by containing 0.4-2.0wt% of halogen capable of being eliminated by hydrolysis.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-viscosity epoxy resin composition that has low irritation to the human body, high curing speed, and excellent performance of the cured product.

Epoxy resins are widely used in many fields such as painting, adhesion, casting, lining, and lamination, but depending on the application, they can be used to improve flowability, defoaming properties, impregnation of cloth, and filling. It may be necessary to lower the viscosity of the epoxy resin for the purpose of increasing the amount of additive added. Conventionally, for this purpose, a method has been used to lower the viscosity by adding a diluent. Diluents include reactive diluents that have an epoxy group and react with the hardening agent, and non-reactive diluents that do not have an epoxy group and do not react with the hardener.
Reactive diluents are more widely used because non-reactive diluents have low affinity with the cured product and tend to cause phase separation, resulting in poor performance of the cured product.

As reactive diluents, alkyl glycidyl ethers,
There are many glycidyl ethers such as phenyl glycidyl ether and allyl glycidyl ether, olefin oxides, styrene oxide, glycidyl amines, and carboxylic acid glycidyl esters, among which n-butyl glycidyl ether has an excellent diluting effect and is therefore suitable for epoxy resins. It has been used the most since it requires only a small amount to be added, has a high curing speed, and has excellent performance of the cured product.

However, rope tyl glycidyl ether has strong irritating properties, and there is a high risk of causing irritation to the skin and mucous membranes of workers. Although this problem has been pointed out for some time, it has not been addressed, and since there is no alternative to n-butyl glycidyl ether, ropetyl glycidyl ether is currently being used out of necessity.

The inventors have found that using n-butyl glycidyl ether as a diluent for epoxy resin is less irritating to the human body than using n-butyl glycidyl ether as a diluent for epoxy resin, and that the curing speed and performance of the cured product are better than when using n-butyl glycidyl ether as a diluent for epoxy resin. The present invention was achieved by studying a low viscosity epoxy resin composition that is equivalent to the case where the epoxy resin composition was used.

The present invention is as follows.

(A) Liquid epoxy resin (B) Alkyl glycidyl ether in which the argyl group has 8 or more carbon atoms A mixture of the above (A) and (13), wherein (A) and (
The weight ratio with B)/(+3) is 60/4o to 90/
The present invention is a low-viscosity epoxy resin composition characterized in that the content of halogen, which can be removed by hydrolysis, is in the range of 0.4 to 2.0% by weight. (Hereinafter, % by weight is simply referred to as "article.") The liquid epoxy resin (A) used in the present invention may have two or more epoxy groups in one molecule and be liquid at room temperature. Preferred epoxy resins include, for example! tld:
, 2, 2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, and other diglycidyl ethers produced by the reaction of epihalohydrin and diphenylolalkane. Representative ld, 2.2-
It is digrindyl ether of bis(4-hydroxyphenyl)propane (commonly known as bisphenol A).

In addition, polyglycidyl ethers of aliphatic polyhydroxy compounds, polyglycidyl esters of polyhydric carboxylic acids, polyglycidyl esters of polymers of unsaturated fatty acids, etc. can also be used.

Examples of the alkyl glycidyl ether (B) in which the alkyl group has 8 or more carbon atoms include alkyl glycidyl ethers such as octyl, 2-ethylhexyl, nonyl, tecyl, undecyl, dotecyl, tridenyl, and tetradecyl, and mixtures thereof.

The skin irritation of the above-mentioned alkyl glycidyl ethers whose alkyl group has 8 or more carbon atoms is weak, equivalent to bisphenol A liquid epoxy resin, and classified as C1as in the 8PI classification.
Belongs to s2. On the other hand, n-butyl glycidyl ether has strong skin irritation and belongs to C1ass 4 in the 8PI classification. Therefore, if an alkyl glycidyl ether having an alkyl group having 8 or more carbon atoms is used as a diluent, the irritation to the human body can be significantly improved.

U-' 8PI (5ociety of
the Plastics Industry
ry) standards for skin irritation.

C1ass t Virtually non-irritating Qlass 2
Weakly irritating C1ass 3 Moderately irritating C1ass 4
Strongly irritating C1ass 5 Significantly irritating 5- Class 6 Moths/suspected to occur in animals When the number of carbon atoms in an alkyl group becomes extremely large, the dilution effect decreases. The number of carbon atoms is preferably 14 or less.

The weight ratio (A)/(B) of (A) and (B) needs to be from 60/4o to 90/1o. If it is less than 60/4o, the performance as an epoxy resin will not be satisfied, and if it is less than 90/1o.
If it is larger, the viscosity will not be lowered sufficiently and there is no point in using (B).

A halogen that can be eliminated by hydrolysis is, for example, when a compound having a hydroxyl group and shrimp lohydrin are reacted to introduce an epoxy group, as shown in the following formula (1).
The reaction proceeds in accordance with formula (2), but the reaction of formula (2) is not completed and the halogen remains in the form of formula (1).
Detach as in 2). Hereinafter, this halogen will be referred to as hydrolyzable I-logen. Since epichlorohydrin is generally used as the epihalohydrin, chlorogen is often chlorine.

0 0HX OHX OX
:Halogenohydrolyzable...The amount of halogen can be controlled by the amount of alkali added during the reaction of formula (2).
iJ Noh.

The following method is exemplified as a method for measuring the amount of hydrolyzed i3J'-nologen.

(1) Place samples 6 to 8 in a 300 rnl Erlenmeyer flask.
Weigh t accurately, toluene 15d1 ethanol k 1,000
50di of a solution of potassium hydroxide 6I dissolved in ml
Add, heat and stir with a condenser attached.

(2) Heat under reflux for 10 minutes and cool to room temperature.

(3) Using phenolphthalein as an indicator, 1.

Titrate with normal aqueous hydrochloric acid solution.

(4) Calculate the amount of hydrolyzable rogens according to the following formula.

Amount of hydrolyzable halogen (%) - W: Weight of sample (t) f: Strength of 14° normal hydrochloric acid aqueous solution Q: 1 in blank test. Titration amount of normal hydrochloric acid aqueous solution (m
l) s:Z. Titration amount (ml) of normal hydrochloric acid aqueous solution M: Atomic weight of halogen If the amount of hydrolyzable halogen is less than 0.4%, the curing speed is low and unsuitable for practical use, and if it is more than 2.0%, the performance of the cured product is poor. is still inappropriate for practical use. A composition comprising an epoxy resin and an alkyl glycidyl ether whose alkyl group has 8 or more carbon atoms only has a low irritating property and a low curing rate when the amount of hydrolyzable halogen is in the range of 0.4% to 2.0%. Moreover, the performance of the cured product is equivalent to that of a conventional epoxy resin composition diluted with n-butyl glycidyl ether. This was not clear until now.

Hydrolyzability: rogens may be contained in large amounts on the epoxy resin side, or may be contained in large amounts on the alkyl glycidyl ether side, and hydrolyzable epoxy resins with different amounts of rogens may be used together. In short, the final composition can be hydrolysed...the amount of rogene is between 0.4% and 2.0%.
That's fine.

The composition of the present invention can be cured in exactly the same manner as conventional diluent-added low-viscosity epoxy resins, and additives such as fillers and colorants can be used in exactly the same manner. , paint, adhesive, casting.

It can be used in a wide range of applications such as lining, lamination, and impregnation while ensuring worker safety.

Hereinafter, it will be explained in detail using examples. In the examples, parts represent parts by weight.

Example 1 Evolai) M 800 (2-ethylhexyl glycidyl ether manufactured by Kyoeisha Yushi. 12 oo per epoxy, viscosity 4
cps, hydrolyzable chlorine amount 0.4%) 15
and 9-A, Ba331 (bisphenol digrindyl ether manufactured by Asahi Kasei Corporation. Epoxy equivalent: 189. Viscosity II: 14,
000cps, hydrolyzable chlorine amount 0.05%) 3
Bisphenol A diglycidyl ether containing 2 parts and 1.6 parts of hydrolyzable chlorine (epoxy equivalent weight 209.9 parts).
53 parts (viscosity 17,500 cps) were mixed uniformly to give an epoxy equivalent of 201. A composition with a viscosity of 850 cps and a hydrolyzable chlorine content of 0.9 was obtained. To this, add 17 parts of gysylylenediamine as a curing agent (an amount corresponding to one epoxy group and one active hydrogen of the amine.Hereinafter, the amount of curing agent added is the same), take the 507, and let it cool to room temperature. When the time to gelation was measured, it was 82 minutes.

Example 2 20 parts of Eboni) A-6 (2-ethylhexyl glycidyl ether manufactured by Nitto Kasei. Epoxy equivalent = 250. Viscosity 5 cps, hydrolyzable chlorine amount 0.4%) and hydrolyzable chlorine amount 1.6%. 80 parts of bisphenol A diglycidyl ether containing epoxy equivalent of 219. Viscosity 72
A composition with a hydrolyzable chlorine content of -10 to 1.4% was obtained. 16 parts of xylylene diamine was added to this, and the gelation time was measured in the same manner as in Example 1 and found to be 65 minutes.

Example 3 Broctor and Gear/Pull Epoxide NO.

7 (Mixture of n-octyl glycidyl ether and n-decyl glycidyl ether manufactured by Glocter & Gamble Co., Ltd. Epoxy equivalent: 291. Viscosity: 10 cps.

Hydrolyzable chlorine amount 0.1%) 20 parts and λER331
and 60 parts of bisphenol A diglycidyl ether containing 1.6% of hydrolyzable chlorine were uniformly mixed to obtain an epoxy equivalent of 221. Viscosity 900 cps.

A composition having a hydrolyzable chlorine amount of 1.0% was obtained. 15 parts of xylylene diamine was added to this, and the gelation time was measured in the same manner as in Example 1 and found to be 86 minutes.

Example 4 Broctor and Gear/Pull Epoxide N098 (
A mixture of n-dodecyl glycidyl ether and n-tetradecyl glycidyl ether manufactured by Procter & Gamble. Epoxy equivalent: 299. 20 parts of bisphenol A diglycidyl ether (epoxy equivalent: 214, viscosity: 17,900 cps) containing 33,140 parts of AER and 1.7% of hydrolyzable chlorine were mixed. and epoxy equivalent weight 221. Viscosity 750 cps, hydrolyzable chlorine amount 0
．． A 7% composition was obtained. Add 1 xylylene diamine to this
When 5 parts were added and the gelation time was measured in the same manner as in Example 1, 1
It was 05 minutes.

Comparative Example 1 In Example 1, 20 parts of Evolai) M 800,
AFiR331 is 80 parts, and the amount of hydrolyzable chlorine is 0.
．． It was set at 1%. The gelation time of this composition was 150 minutes;
It became significantly longer than Example 1.

Comparative Example 2 In Example 3, Broctor & Gear/Pull Epoxide No. 7 was used as 20 parts, AB 331 was used as 80 parts, and the amount of hydrolyzable chlorine was set as 0.06%. The gel time for this composition was 160 minutes, which was significantly longer than in Example 3.

Comparative Example 3 10 parts of Epiol B (n-butyl glycidyl ether manufactured by NOF Corporation, epoxy equivalent: 142. Viscosity: 2 Cll5 + hydrolyzable chlorine amount: 0.4%) and 90 parts of 18331 were mixed, and epoxy equivalent: 187. A composition with a viscosity of 910 cps and a hydrolyzable chlorine i of 0.08% was obtained. 18 parts of xylyle/diamine were added to this, and the gel time was measured in the same manner as in Example 1 and found to be 90 minutes.

Example 5 Examples 1, 2, 3, 4. Table 1 shows the performance of the cured products obtained by curing the compositions of Comparative Examples 1 and 3 at room temperature for 7 days using triethylenetetramine as a curing agent.

The compositions of Examples 1 to 4 have almost the same performance as the product of Comparative Example 3 using n-butyl glycidyl ether. In contrast to the composition of Comparative Example 1, which has a small amount of hydrolyzable chlorine, the compositions of Examples 1 to 4 have excellent adhesive strength.

(Applicant 1...Poor color) 13- Table 1 Comparative example of performance of cured product 4 Eponits) A-620 parts and amount of hydrolyzable chlorine 3.
Bisphenol A diglycidyl ether 80 containing 0% i
The components were uniformly mixed to obtain a composition containing 2.5% of hydrolyzable chlorine. When the performance of the cured product was measured in the same manner as in Example 5, it was found that the tensile strength 2 bending strength was about 4 compared to the composition of Comparative Example 3, indicating that the performance was degraded.

As described above, the present invention uses as a diluent an alkyl glycidyl ether having an alkyl group having 8 or more carbon atoms, which has low 14-irritability to the human body, and uses a hydrolyzable chlorine needle with a concentration of 0.4 to 2. By controlling the viscosity within the range of 0, it is possible to provide a low-viscosity epoxy resin composition that has a high curing speed, excellent performance of the cured product, and low irritation to the human body.

Patent applicant: Asahi Kasei Industries, Ltd. 15- 145-

Claims (1)

[Scope of Claims] (A) Liquid epoxy resin (B) Alkyl glycidyl ether whose alkyl group has 8 or more carbon atoms A mixture of the above (&) and (B),
)/(B) is in the range of 60/4o to 90/1o, and the content of halogen that can be eliminated by hydrolysis is in the range of 0.4 to 2.0% by weight. A low viscosity epoxy resin composition characterized by