| 摘要 |
1,258,530. Paper. ARAKAWA RINSAN KAGAKU KOGYO K.K. 23 Dec., 1969 [27 Dec., 1968], No. 62559/69. Headings D2A and D2B. Paper is surface-sized by applying an aqueous dispersion of a saponified modified rosin to the surface of paper made from a slurry containing aluminium sulphate, and then drying. The modified rosin is an adduct of rosin and an alpha-beta-unsaturated aliphatic polybasic acid or its anhydride partially esterified with an aliphatic polyhydric alcohol, so that the product has an acid value of 90-200 and a softening point of 90-180‹C and contains free hydroxyl groups equivalent to not more than 50% of those in the polyhydric alcohol used. The rosin may first be reacted with the acid, and the adduct then esterified, or the acid may be first partially esterified and then reacted with the rosin. Acids referred to are maleic, fumaric, citraconic and itaconic; alcohols are glycerine, pentaerythritol, ethylene glycol, its dimer and polymer, neopentylglycol, trimethylolethane and trimethylolpropane. The rosin used may be gum rosin, wood rosin, tall-oil rosin or a rosin derivative having an ethylenic double bond in the molecule, e.g. a partly polymerized or partly hydrogenerated rosin. The modified rosin is saponified with an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, monoethanolamine, diethanolamine or triethanolamine. It may be applied by tubsizing, press-sizing or calender-sizing, and may be applied in combination with starch or wax emulsion. The specification also describes by way of comparison sizing compositions comprising (I) a similar esterified adduct of higher acid value, (II) one of higher freehydroxyl content, (III) a plain rosin soap, (IV) a saponified rosin-maleic acid adduct (not esterified), and (V) a petroleum rosin modified by addition of maleic anhydride, then mixed with gum rosin and saponified. In one example (4), comparison composition IV and aluminium sulphate are added to a pulp slurry, and weakly sized paper made from the slurry; after drying this is sized in a press with three compositions of the invention and the five comparison compositions. In another example (5), a sizing composition of the invention is mixed with corn starch, and applied similarly. |
