Abstract
(1) Introduction.
(2) Problems on the Chemical Constitution of Lignin. By means of hydrogeniolysis.Y. Hachihama and S. Jyodai concluded in 1943-1944 that there were to be three kinds of lignin building stone (I), (II) and (III). (I) is only concerned to the consti-
(I)
(II)
(III) tution of soft wood lignin. Hard wood lignin shall be constructed from building stone of type (I) and (II). Grass lignin shall be constructed from all these types. In 1944, S.Jyodai obtained a dimer of the building stone from Ezomatsu by means of hydrogenolysis which was named Hydrolignin. The constitution of this Hydrolignin, in which two moles of lignin building stone combined in their side chains each other, was discussed. (3) Problems of Pulping. Sulfite pulping of heart wood of pines was discussed. The diffi culty of these sulfite pulping was conquered by adding a small quantity of cationoid reagent such as formalin. (4) Problems of Derivatives of Lignin. (5) Problems of Utilization of Lignin. (6) Conclusion.
