OPTICALLY BRIGHTENED LATEXES Russian patent published in 2023 - IPC D21H21/30 D21H17/37 D21H19/56 C09D157/00 

FIELD: chemical industry.

SUBSTANCE: present invention relates to a group of inventions: a method for producing an aqueous composition, an aqueous composition for optical brightening of a cellulose substrate, the use of an aqueous composition, a coating composition, a method for optically brightening a cellulose substrate, and a cellulose substrate. The method for obtaining an aqueous composition includes emulsion polymerization of at least one ethylenically unsaturated monomer in the presence of at least one water-soluble diaminostilbene-disulfone optical brightener of formula (1):

This method includes the steps: a) preparing an aqueous solution containing or consisting of at least one water-soluble diaminostilbene-disulfone optical brightener of formula (1) and optionally at least one dispersing agent; b) preparing a homogeneous pre-dispersion, the pre-dispersion containing or consisting of at least one ethylenically unsaturated monomer, water and at least one dispersing agent; c) preparing an aqueous solution containing or consisting of a water-soluble azo compound of formula (2) and/or formula (3); d) adding the pre-dispersion obtained in step (b) and the aqueous solution obtained in step (c) simultaneously to the aqueous solution obtained in step (a). The aqueous composition is used to optically brighten a cellulose substrate. The coating composition contains this aqueous composition. A method for optically brightening a cellulose substrate includes: applying a given aqueous composition or coating composition to a cellulose substrate and drying the cellulose substrate. A cellulose substrate treated with a given aqueous or coating composition.

EFFECT: development of water-based latex binders that are easily produced in the form of an emulsion, resistant to washout, capable of providing a higher threshold of whiteness without the use of carriers, toxicologically safe and economical to use.

17 cl, 2 tbl, 7 ex