| 配方類型： |
PAPER |
| 配方說明： |
Alkaline Casein Solution |
| 配方組成： |
Borax/5
It will be noted that trisodium phosphate is not included in these
formulae. This chemical has been used extensively and gives thin
solutions, especially with colors containing satin white. However,
color, foaming tendency, lower paper adhesive strength, and other
difficulties resulted in the elimination of trisodium phosphate from
most coating formulae. Sodium hydroxide can be used, but often is
avoided because of possible excessive alkalinity, with resulting
|
| 配制方法： |
In work at the University of Michigan, it was indicated that increasing amounts of alkali give a better coating bond (higher wax test). Excess alkali certainly is necessary to take care of minor variations in casein acidity and pigment absorption, to give complete casein solution, to obtain proper color flow, and to give thin colors when satin white is used. However, it has been found that the use of excessive amounts of alkali (for example, to obtain higher wax tests) is not always good practice. Difficulties that might be encountered include: printing trouble, foaming trouble, brittleness of the coating, decomposition of the coating color, and darkening of the sheet color. |
|
