To provide a chemical agent for papermaking improving yield and productivity in the papermaking process of paper and paperboard without impairing formation of paper; and a method for papermaking using the chemical agent.
In the papermaking method, addition and mixing of the chemical agent for papermaking is performed such that a part of main papermaking raw material flow having passed the last screen is made as a bypass flow, in the papermaking raw material before papermaking; the bypass flow is further divided in two or three; these branch flows are mixed with chemical agents for papermaking by one or two mixing means; and the mixture is returned to the main papermaking raw material flow. The chemical agent for papermaking adaptable to the papermaking method is a water-in-oil type emulsion of water-soluble cationic or ampholytic polymer. obtained by emulsion polymerization of a vinylic monomer or a mixture thereof, whose viscosity in 0.2% aqueous solution is 300 mPa s or lower.
HIRATA KAZUYUKI
HAYASHIDA TAKEKAZU
| JPS557826A | 1980-01-21 | |||
| JP2005511869A | 2005-04-28 | |||
| JPH06157669A | 1994-06-07 | |||
| JPH0841114A | 1996-02-13 | |||
| JP2002145956A | 2002-05-22 |