Date of Award
Bachelor of Science
Paper Science and Engineering
Dr. Ellsworth H. Shriver
The prime function of a paper coating insolubiliser is to reduce the water solubility or sensitivity of the pigment binders used in the coating composition. The degree and amount of water solubility will depend on the type and amount of binder used (1). This is important in many applications of coated paper or paper board. Tags, instruction manuals, poster board and wall paper all require varying degrees of resistance to water.
Coating insolubilities can be broken into two main categories: waterproof and water resistance. Waterproof refers to products that have been rendered impervious to water by hydrophobic materials such as wax.
Water resistance refers to coatings that slow the rate of or amount of liquid penetration. Most coated paper and paperboard is printed with water base inks so coatings must be somewhat porous to receive ink. However, the critical factor is how much the coating binder becomes solubilized and particles loosened.
There are a three main methods to obtain water resistance in a paper coating. The first is method utilizes the incorporation of highly water-repellent materials such as waxes of metallic soaps. The second is incorporating binders of low water sensitivity into the coating composition. The last method and the method that I will be studying involves the formation of insolubility through cross-linking reactions of coatings with an added metal salt, amino group, or aldehyde (2).
Brigham, Scott, "Coating Insolubilization: A Comparison of AZC and KZC" (1996). Paper Engineering Senior Theses. 11.