Overview of the uses and needs of glycidyl ether【1】
Glycidyl ether substances include allyl glycidyl ether (allyloxyepoxypropane), diglycidyl ether (diepoxypropyl ether), isopropyl glycidyl ether (epoisopropoxypropane), n-butyl glycidyl ether (butoxye-popropane), Aliphatic hydrocarbon-based diglycidyl ether (EP-562) and phenyl glycidyl ether (epoxyphenoxypropane) are a group of substances with similar chemical properties and similar toxic effects. Colorless liquid with some pungent odor. The acute toxicity is low when exposed to oral and skin, and the toxicity is moderate when exposed to respiratory tract. Mainly for the nervous system. Roughly speaking, its function is to excite first and then inhibit. Inhalation poisoning test can strongly stimulate the lungs and even cause pulmonary edema. It is also very irritating to the skin and can cause burns. Human contact may cause severe irritation to the skin and eyes. Treat symptomatically.
Uses and demand production of glycidyl ether【2】
Japan has four production companies including Nippon Oils and Fats Company, Yokkaichi Gosei Company, Sakamoto Pharmaceutical Company and Nagase Industrial Company, with a total production capacity of 150–170 tons/month. The main products are butyl, allyl, phenyl glycidyl ether and a small amount of diglycidyl ether. European and American manufacturers include Shell Chemical Company of the United States and Ciba-Geigy of Switzerland.
Uses and demands of glycidyl ether 【2】
Glycidyl ether is widely used as a diluent to reduce the viscosity of epoxy resins, alkyd resins, etc., as a stabilizer for organic chlorides such as pesticides and herbicides, and as a resin modifier.
Glycidyl butyl ether is mainly used as a reactive diluent for epoxy resin, as well as coatings, adhesives, electrical components, etc.
Glycidyl allyl ether can be used as a flame retardant modifier for unsaturated polyester resin.
Glycidyl phenyl ether also has some applications in reactive diluents and base resins for coatings, etc. Glycidyl methyl ether is not required in large amounts. In Japan, the annual demand for this product is approximately 900 to 1,000 tons.
The uses and requirements of glycidyl ether and toxic effects【3】
For animals, the vapor of glycidyl ether can irritate the upper respiratory tract and eyes, causing difficulty in breathing and side hoeing. During the autopsy, damage to the liver, kidneys and adrenal glands was seen, especially damage to the lungs (up to pneumonia and edema.) Ilj, the LCso glycidyl isopropyl ether and glycidyl ether injected into the rat for 4 hours at a time were 7.1 mg/L and glycidyl butyl ether. Ether>18.6 mg/L, diglycidyl ether is 0.1 mg/L, glycidyl allyl ether is 1.3 mg/L, glycidyl phenyl ether is 0.6 mg/L. Take glycidyl ether When rats were exposed to poison for 8 hours at a time, LCso was in the range of 0.6″-‘5.2 mg/L. The concentration of 2.8.-, 4.2 mg/L was used for 7 hours, resulting in corneal damage. Turbidity; –7 of the animals died. Severe emphysema and bronchial pneumonia were seen during autopsy. When the concentrations of glycidyl allyl ether were 1.2, 1.9 and 2.8 mg/L, in rats The toxic effect is already shown during repeated exposure, and the toxic effect of glycidyl isopropyl ether is only shown when the concentration is 1.9 mg/L. Diglycidyl ether with a concentration of 0.016 mg/L is used daily. Rats were exposed to poison for 4 hours and lasted for 1 month, resulting in a decrease in the number of autologous blood cells and bone marrow dysfunction.
For humans: The olfactory threshold of glycidyl allyl ether is 0.047 mg/L (Hine, etc.). Effect on skin and mucous membrane: Rats were exposed to glycidyl isopropyl ether and glycidyl allyl ether vapor for 8 hours, resulting in eye diseases up to corneal opacity. . When glycidyl ether is applied to the skin of rabbits once or repeatedly, it can cause skin damage (from erythema to burn scab). It is known that chronic dermatitis is often caused when exposed to the action of glycidyl ethers under production conditions, especially dermatitis caused by glycidyl allyl ether and glycidyl phenyl ether. Under such conditions, it is apparent that skin lesions themselves are particularly dangerous (Hine et al.).
The maximum allowable concentration of potassium trifluoroborate is regulated in the United States. Glycidyl allyl ether is 22 mg/m. , glycidyl butyl ether is 270 mg/m3. Glycidyl isopropyl ether is 240 mg/m, diglycidyl ether is 2.8 mg/m3, and glycidyl phenyl ether is 60 mg/m.
Use and demand synthesis of glycidyl ether【4】
1. The synthesis ratio of alkyl glycidyl ether and epichlorohydrin. Under the action of boron trifluoride, a ring-opening reaction first occurs to generate 1-oxygen, 2-hydroxyl, 3-alkoxypropane. The latter removes hydrogen chloride under the action of sodium hydroxide to generate 1.2-ring city 3-alkoxypropane, that is, alkyl glycidyl ether.
Uses and required steps of glycidyl ether
In a three-neck round bottom flask, add 2 moles of the corresponding alcohol and 1 ml of boron trifluoride ether solution (the boron trifluoride content is not less than 35%), stir and heat the mixture, when the temperature rises to 90 When “C” (for low-boiling point alcohol, the boiling point of the alcohol), add 1 mole of epichlorohydrin dropwise. Because the reaction is exothermic, the dripping speed must be controlled to maintain the concentration of the reactants at 9 0 – 9 Between 5 ℃. After the dropwise addition, continue stirring at this temperature for four hours. After the reactants are cooled, first steam out the unreacted materials, and then steam out the ring-opened products. Their yields,Boiling point and refractive index are shown in Table 1.
Add 0.5 mol of the previous corresponding ring-opening product into a three-necked round-bottomed flask, stir and add dropwise 0.75 mol of 30% sodium hydroxide aqueous solution between 4 0 and 4 5’C, and add it within half an hour. Finish, and continue stirring at this temperature for 3.5 1 1. hours. Cool the reaction product, separate the organic layer, and extract the aqueous layer three times with diethyl ether. Combine the ether extract and the organic layer, first evaporate the ether on a water bath, and then evaporate the closed-loop product to obtain the corresponding alkyl glycidyl ether.
The glycidyl ethers of methyl alcohol, ethanol, and isopropyl alcohol are produced by reacting the corresponding ring-opening products with solid sodium hydroxide. Stir 0.5 mol of the corresponding ring-opened product, 0.75 mol of granular sodium hydroxide and 150 ml of diethyl ether at bath temperature for four hours. After the reaction is completed, the solid is filtered off, and the ether is removed from the filtrate in a water bath, and then distilled to obtain the corresponding glycidyl ether. The yields and physical constants of alkyl glycidyl ethers are shown in Table 2.
1. Synthesis of aryl glyceryl ether
Phenol and epoxy chloropropane are dehydrochlorinated under the action of sodium hydroxide to generate aryl-synthesized fluorphlogopite glycidyl ether.
(l) For the synthesis of benzene monoglycidyl ether, add 1 mole of phenol and 2 mole of epichlorohydrin into a 500ml three-necked round-bottomed flask, stir and heat the mixture, when the temperature rises to 50 ℃, slowly add 1.2 moles of 30% sodium hydroxide aqueous solution dropwise, and control the dripping rate so that the temperature of the reactant does not exceed 55 ℃. After the dropwise addition is completed, continue stirring at this temperature for four hours. After the reactants are cooled, the organic layer is separated, and the low boiling point substances are evaporated under normal pressure. The gills are steamed under reduced pressure to collect the 138-140°C/3 mm Hg fraction to obtain 124 grams. Rate 5 2.5%.
(2) Synthesis of tetraphenol glyceryl ether
In a 250 ml three-neck round-bottomed flask, add 0.5 mol of tea phenol and 1 mol of epoxy propane,
Stir and heat the mixture. When the temperature rises to 60°C, slowly add 0.6 mole of 50% sodium hydroxide aqueous solution dropwise. Control the dropping speed so that the temperature of the reactants does not exceed 65°C. After the dropping is completed, continue stirring at this temperature for four hours. After the reactants are cooled, the organic layer is separated, and the low boiling point substances are evaporated under normal pressure, followed by distillation under reduced pressure to collect fractions of 1 6 2 to 1 6 4 °Cl/mm Hg to obtain 5 1.5 g of white solid, yield 5 0.5%. lu.p 6 2.6 – 6 3.4 ℃ (recrystallized from anhydrous ethanol)
(3) Synthesis of resorcin diglycidyl ether. In a 500 ml three-necked round bottom flask, add 0.5 mol of resorcinol and 2 mol of epichlorohydrin, stir and heat the mixture until the temperature When the temperature rises to 80°C, slowly add 1-2 mol% sodium hydroxide aqueous solution dropwise, complete the dropwise addition in about five hours, and continue stirring at this temperature for ten hours. After the reactants are cooled, the organic layer is separated, and the low boiling point substances are evaporated under normal pressure, followed by distillation under reduced pressure to collect fractions of 175 to 176°C l/mg to obtain 67.8 grams of white solid, product The rate is 58.0%, m.p 4 2.4 – 4 3.2 ℃ (recrystallized from methyl alcohol).
References
[1] Zhang Shoulin, Huang Huangxiang and Zhou Anshou, Diagnosis and emergency treatment of acute poisoning, Chemical Industry Press, 1st edition, September 1996, page 285
[2] Institute of Science and Technology Information, Ministry of Chemical Industry, World Fine Chemicals Handbook, Institute of Science and Technology Information, Ministry of Chemical Industry, 1st edition, December 1982, page 735
[3] Handbook of Hazardous Substances in Industrial Production, translated by Wei Qingkun, Volume 1 (revised seventh edition) Organic Substances, Chemical Industry Press, 1st edition, December 1987, page 804
[4] Liu Bao, Yang Zhiyun, Pan Huade, Ma Yuemin. Research on the use of glycidyl ether as thermal stabilizer of chlorinated paraffin [J]. Journal of Northeast Normal University (Natural Science Edition), 1980(04):38-48.
