Abstract: An aqueous dispersed solution of a substituted succinic anhydride which comprises an aqueous soluble copolymer (A) having 50 percent or more by mol of (meth)acrylamide (a) 1 percent or more by mol of N,N-dialkylamino.alkyl(meth)acrylamide (b) as monomer ingredients, aqueous soluble copolymer (B) having 50 percent or more by mol of (meth)acrylamide (a), 1 percent or more by mol of N,N-dialkylamino.alkyl(metho)acrylamide (b) and 49 percent or less by mol of other copolymer monomer (c) as monomer ingredients, or both of the dqueous soluble copolymer (A) and the aqueous soluble copolymer (B), and a process for producing an aqueous dispersed solution of a substituted succinic anhydride prepared by dispersing the aqueous soluble copolymer (A) or the aqueous soluble copolymer (B) or a mixture (C) of 99 to 99.9 percent by weight of the substituted succinic anhydride (d) and 10 to 0.

Abstract: A process for making paper using a substituted succinic anhydride as a sizing agent which has the steps of preparing pulp slurry containing (a) an aqueous dispersion of a substituted succinic anhydride in which a cationic tapioca starch containing at least 0.3 percent by weight of basic nitrogen is added and mixed, and (b) a colloidal silica, and forming a paper sheet to improve the retentions of a fine fiber and a filler in the pulp slurry in the sheet forming step and to largely suppress the operation of decreasing the sizing performance of the substituted succinic anhydride with the colloidal silica (b) added as the retention aid, thereby preparing sheet paper having excellent sizing effect. Thus, the process for making paper can not only remarkably reduce the sizing cost but can also efficiently utilize the fine fiber and the filler in the pulp slurry.

Abstract: A composition for a sizing agent comprising (a) 70-99.9 wt.% of a substituted alkyl succinic anhydride or a substituted alkenyl succinic anhydride or a mixture of these succinic anhydrides, and (b) 0.1-30 wt.% of phosphates of polyoxyethylene alkyl ether esters or phosphates of polyoxyethylene alkyl aryl ether esters of a mixture of these phosphate esters and a process for using the composition by dispersing the composition, adding the produced aqueous dispersion to pulse alurry of paper making material, and making the paper. This composition for the sizing agent has excellent storage stability and underwater self-emulsion, and accordingly exhibits an excellent sizing effect and provides paper having an excellent sizing effect.

Abstract: A composition for a sizing agent comprising (a) 70-99.9 wt. % of a substituted alkyl succinic anhydride or a substituted alkenyl succinic anhydride or a mixture of these succinic anhydrides, and (b) 0.1-30 wt. % of phosphates of polyoxyethylene alkyl ether esters or phosphates of polyoxyethylene alkyl aryl ether esters of a mixture of these phosphate esters and a process for using the composition by dispersing the composition, adding the produced aqueous dispersion to pulse slurry of paper making material, and making the paper. This composition for the sizing agent has excellent storage stability and underwater self-emulsion, and accordingly exhibits excellent sizing effect and provides paper having an excellent sizing effect.

Abstract: An improved sizing is feasible by adding into a papermaking pulp slurry an aqueous dispersion prepared by mixing an aqueous solution of an ampholytic acrylamide polymer having both cationic and anionic groups with a liquid substituted succinic anhydride or with an anhydrous liquid mixture of a liquid substituted succinic anhydride and an oil-in-water type surfactant. Such a paper sizing process is very useful for making plasterboard base paper of multilayered structure composed of at least one surface layer having a high hot water resistance and at least one back layer having a good adhesiveness to plaster slush.

Abstract: A cellulose treating agent obtained by dispersing an alkyl ketene dimer in water in the presence of a dispersing agent comprising a reaction product of a polyalkylenepolyamine and a mixture of carboxylic acids containing at least 20% by weight of aliphatic monohydroxymonocarboxylic acids having 9 to 32 carbon atoms or a product obtained by reacting epihalohydrin with said reaction product. This cellulose treating agent existing as a very stable cationic aqueous dispersion of the alkyl ketene dimer is highly effective to impart a water repellency to cellulose fibers and can be used as a well-improved reactive sizing agent for papermaking.

Abstract: A neutral sizing agent of emulsion type to be added to paper pulp for facilitating the disaggregation and recovery of waste paper in making paper including paper board, said sizing agent being produced, for example, by dispersing in an aqueous emulsifying dispersion medium a polymerizable hydrophobic monomer such as styrene or 2-ethylhexyl methacrylate by using as an emulsifying dispersing agent a copolymer having units of one or more monomers given by the formula ##STR1## or ##STR2## wherein R is H or CH.sub.3,X is a halogen atom,A is a (C.sub.2 -C.sub.6) alkylene group, andY is an anion,and a monomer given by the formula ##STR3## wherein R.sup.1, R.sup.2 are H or CH.sub.3, and then subjecting the resultant dispersion to a radical emulsion polymerization.