The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1991
Filed:
Feb. 16, 1990
Naotaka Watababe, Tokyo, JP;
Takao Arai, Yokohama, JP;
Hitoshi Fujiyoshi, Yokohama, JP;
Masako Shirota, Yokohama, JP;
Mitsui-Cyanamid, Ltd., Tokyo, JP;
Abstract
A method of preparing a paper having a reinforced strength wherein a polymer latex is added to a paper stock in an amount of from 2.5 to 30% by weight. The polymer latex is prepared by neutralizing a seed polymer with an acid or a salt or by quaternizing it with a quaternizing agent. The surfaces of the emulsion grains are provided with a large number of cationic groups. The seed polymer is formed by adding a monomer represented by the following formula (I) or a mixture of the monomer (I) and copolymerizable ethylenic unsaturated monomer(s) (II) to a seed latex of a carboxyl-modified synthetic rubber latex or synthetic resin emulsion and polymerizing them: ##STR1## R.sub.1 represents H or CH.sub.3 ; R.sub.2 represents an alkylene group having from 2 to 5 carbon atoms;