AQUEOUS COMPOSITIONS AND THEIR APPLICATION IN PAPER AND CARTON MAKING Russian patent published in 2009 - IPC C01B33/20 D21H17/66 

FIELD: chemistry; textiles; paper.

SUBSTANCE: preparation method of polysilicate containing aqueous composition representing homogeneous liquid at 25°C, includes stages as follows: I) preparation of aqueous liquid containing silicate, II) reducing pH of the liquid to 2-10.5, III) ensured polymerisation time to actual completion resulted in making product containing gelled substance, IV) processing gelled substance with sufficient shearing to produce homogeneous liquid. Aqueous composition is prepared by the presented method. Aqueous composition contains polysilicate. This composition represents homogeneous liquid at 25°C. The composition develops viscosity at least 200 mPa·s when evaluated at concentration 2 wt % and at 25°C with using Brookfield viscosimeter at 20 rpm with shaft №2, with polysilicate of specific surface area not exceeding 2000 m²/g and S-value below 5%. Paper or carton making process includes preparation of cellulose suspension, with aqueous composition added, water drainage from suspension thus shaping wet paper web thereafter dried. Paper or carton making process includes preparation of cellulose suspension, added with mineral filler and exposed to drainage and containment system procedure, followed with water drainage from suspension thus shaping wet paper web thereafter dried. Mineral filler is aqueous composition. Before drainage and containment system is enabled, the suspension is exposed to at least, one shearing. This system implies adding aqueous composition to cellulose suspension, while shearing stage is specified from stirring, clarification and pumping.

EFFECT: improved quality of paper and carton.

46 cl, 16 tbl, 6 ex, 2 dwg