Lactic Acid → Hydroxyacetic acid--2-hydroxypropanoic acid (1/1)

温度

175 °C

To 160 g of 85% aqueous lactic acid solution and 38 g of glycolic acid was added 17.4 g of acid clay and the mixture was heated in a nitrogen atmosphere for 6 hours while increasing the temperature and degree of pressure reduction stepwise in a manner such that the inside temperature and pressure were initially 105° C. and 350 mmHg, respectively, and finally 150° C. and 30 mmHg, respectively and while removing the water distilled. Thereafter, the inside pressure was reduced to 3 mmHg and heating was conducted for 36 hours while maintaining the inside temperature at 175° C. The reaction mixture was cooled to room temperature, 400 ml of methylene chloride was added, the resulting mixture was stirred for dissolution of the polymerization product, the acid clay was then filtered off, and the filtrate was concentrated to dryness to give a white lactic acid-glycolic acid copolymer.

1. temperaturethe mixture was heated in a nitrogen atmosphere for 6 hours
2. temperaturewhile increasing the temperature and degree of pressure reduction stepwise in a manner such that the inside temperature and pressure
3. customwere initially 105° C.
4. custom350 mmHg, respectively, and finally 150° C. and 30 mmHg, respectively and while removing the water
5. distillationdistilled
6. temperatureheating
7. temperatureThe reaction mixture was cooled to room temperature
8. addition400 ml of methylene chloride was added
9. filtrationthe acid clay was then filtered off
10. concentrationthe filtrate was concentrated to dryness

ORDレコード

ord-3b11394790b14008ba1480e97c46e2da

出典データセット

uspto-grants-1989_07

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US04849228