Abstract
Paper is commonly surface-sized by means of a size press. Surface sizing of paper is primarily done to decrease the porosity of the surface. Starch is the principal surface sizing agent used commercially. This study is concerned with starch-borate complex colloidal solution as sizing agent. The properties, i. e., dry strength, moisture-resistant property, the degree of sizing and resistance to flame, were improved in comparison with starch only. In the case of preparation of colloidal solution, the most suitable amount of borax added to starch is 1.5 mmol/g (starch). Successively by the addition of phosphoric acid to starch-borate complex colloidal solution there has been remarkable progress in the degree of sizing and resistance to flame.
