| 摘要 |
FIELD: varnish-and-paint. SUBSTANCE: red anthocyanidin dye is prepared from conifer (silver fir or larch) bark. For that, bark is ground, extracted with nonpolar solvent, and boiled for 3.5-4 h in ethyl alcohol containing 2-5% hydrochloric acid in presence of 4-6% pyruvic acid. EFFECT: increased heat and light resistance. 2 ex |
