METHOD FOR PREPARING LARCH NEUTRAL RESIN Russian patent published in 2003 - IPC

FIELD: wood working industry. SUBSTANCE: invention relates to methods for preparing products from natural vegetable raw, in part, larch galipot and can be used in wood chemical, perfume-cosmetic, optical, petroleum chemical and other branches of industry. Method for preparing larch neutral resin involves galipot dissolving in an organic solvent, the prepared solution is purified from litter and water, saponified with 5-10% solution of sodium or potassium hydroxide and mass is separated for aqueous and organic layers. An aqueous layer is extracted with solvent in the ratio 1:1 and then extract is combined with organic layer. Turpentine purified from sulfur-containing compounds or that is better α-pinene are used as solvent. Dissolving is carried out at temperature 85-90 C in the ratio galipot : solvent = from 1:1.8 to 1:2.5. The end product is prepared by solvent distillation off from organic layer that presents the solution of neutral heavily boiling sesquiterpenoids and diterpenoids at temperature 120-130 C using acute steam as addition agent under reduced pressure 40-60 kPa. Method ensures to obtain larch neutral resin with beforehand chemical composition and reduce consumptions for its preparing. EFFECT: improved preparing method. 1 tbl, 4 ex