Studi pemanfaatan gambir (Uncaria gambir Roxb.) dalam pembuatan cat alami
Abstract
The main component of paints are binder, pigment, solvent and additive. Binder can be made from natural materials and also synthetic or polymeric materials. This study was conducted to observe the effect of weight ratio of casein to calcium oxide and concentration of gambier solution in the preparation of natural paint. The binder used in the manufacture of natural paints was casein mixed with calcium oxide (alkali). When casein was reacted with an alkali then casein will become more soluble in water and has adhesive properties. Use of gambier as dyes in the manufacture of natural paints was expected to increase the added value of gambier. Catechin and tannin as the substances contained in gambier will easily dissolve in water and can give brownish red colour.