| 摘要 |
A paper size is produced by reacting rosin first with 1-12% of formaldehyde, then with 3-13% of a C14- 26 fatty acid, and partially or completely neutralizing the product with aqueous alkali solution. The rosin may be gum, wood or tall oil rosin. Formaldehyde may be added to tall oil (rosin and fatty acid) and the temperature raised to effect reaction of the rosin first with the formaldehyde and then with the fatty acid. The formaldehyde may be in the form of paraformaldehyde. It may be reacted at 100-200 DEG C. for 1/8 -4 hrs. at atmospheric or autogenous pressure in the presence of an acid catalyst. The acid may be sulphuric, hydrochloric, phosphoric, acetic, or p-toluene sulphonic acid or acid clay. 0.05-0.5% of acid may be employed. The fatty acid may be tall oil fatty acid, commercial stearic acid, or a fatty acid derived from lard, tallow, or linseed, cotton-seed or safflower seed oil. It may be reacted at 150-240 DEG C. for 1/2 -24 hrs. The alkali may be sodium or potassium hydroxide or sodium carbonate. Neutralization may be 70-95% complete. The modified rosin may be reacted with 1/20 -1 mol. of a fortifying agent before neutralization or may be blended with 20-50% of a neutralized fortified unmodified rosin after neutralization. The fortifying agent may be acrylic, maleic, fumaric, itaconic or citraconic acid. A completely neutralized product may be spray dried. 0.25-5% of the size may be incorporated in paper. |
