CS252021B1 - Sizing compounds for surface sizing of paper, cardboard and cardboard - Google Patents

Abstract

The solution belongs to the field of chemistry. Its essence lies in the fact that the sizing mixtures contain pigments, a dispersant containing polyphosphates and polyacrylates of alkali metals in an amount of 0.1 to 1.6 parts by weight per 100 parts by weight of pigments, binders containing modified starches, cellulose derivatives, casein, proteins, polyvinyl alcohol, or synthetic dispersions in an amount of 43 to 135 parts by weight per 100 parts by weight of pigments. The solution can be used in surface sizing of offset papers, coating substrates and substrates for further surface finishing.

Description

252021

SUMMARY OF THE INVENTION The present invention provides sizing compositions for surface sizing of paper, cardboard and paperboard.

In surface sizing, the properties of the paper are adjusted by applying sizing compositions to the surface of the paper, usually using a sizing press which is part of a paper machine. The surface sizing reduces the tendency of the powder, absorbs the paper material, increases the surface strength and stiffness. U.S. Patent 4,006,112 discloses a sizing agent consisting of a combination of modified starch and polyester.

According to Japanese Patent No. 12 002/75, sapre surface sizing recommends styrene-butyl acrylate copolymer. Me p. U.S. Pat. No. 6,060,677 discloses polyvinyl alcohol, or water-soluble starch in the presence of boric acid, as a suitable blend for surface sintering.

U.S. Pat. No. 2,357,064 discloses surface glazing with copolymers of acrylic or methacrylic acid with alpha olefins.

In all cases, the substances are relatively expensive, which increases the overall cost of paper making.

The above-mentioned drawbacks are solved by the invention, wherein the gelling compositions comprise pigments, a dispersing agent comprising polyphosphates and alkali metal polyacrylates in an amount of 0.1 to 1.6% by weight. parts per 100hmot. parts of pigments and binders, containing modified starches, cellulose derivatives, casein, proteins, polyvinyl alcohol, and bosynthetic dispersions in an amount of 45 to 155 wt. parts per 100 wt. parts of pigments. Although the fillers themselves cannot increase the surface strength, their combination with glue mixtures makes it possible to achieve equal or higher surface strengths than the use of pure sizing compositions.

The solution according to the invention makes it possible to apply sizing compositions with a higher solids content, thereby generating energy savings for drying and increasing the performance of the paper machine from the point of view of functional properties, increasing surface strength, increasing the whiteness and smoothness of the treated papers. Example 1 A suspension is prepared by dispersing 100 kg of kaolin in water containing 0.25 kg of sodium solipolymer of acrylic acid in the presence of 0.1 kg of sodium hydroxide and 0.15 kg of ammonium hydroxide of 40% by weight to disperse the final mixture. The suspension was mixed with 500 kilograms of modified starch solution at 20% by weight and 100 kg of acrylic or polyvinyl acetate dispersion. The mixture is diluted to 20% solids with water. If desired, an antifoam and synthetic glue are added. Example 2 A suspension is prepared by dispersing 60 kg of kaolin and 40 kg of calcium carbonate in water containing 0.30 kg of sodium pyrophosphate as dispersing agent in the presence of 0.10 kg of sodium hydroxide and 0.3 kg of optical brightening agent. to give a final concentration of 68% by weight. 40 kg of 5% w / w cellulose derivative and 90 kg of butadiene styrene dispersion are mixed into the prepared suspension. The mixture is diluted to 26% strength with water. EXAMPLE 3 A suspension is prepared by dispersing 75 kg of kaolin and 25 kg of high white pigment (titanium dioxide, blanc, satin bleach, zinc white, aluminum hydroxide, silicon oxides, synthetic pigments) in water containing 0.20 as a dispersing agent. kg of sodium methacrylic acid polymer and 0.15 kg of pyrophosphate sodium in the presence of 0.15 kg of sodium hydroxide and 5 kg of water-resistant additive, so that the resulting suspension concentration is 61% by weight, and 800 kg of 10% solution is added to the prepared suspension. Example 4 A suspension is prepared by dispersing 60 kg of kaolin, 20 kg of bentonite and 20 kg of talc (talc) in water. The method of Example 1 is the same as in Example 1.

The use of the invention is envisaged where the paper is a starch solution glue or a combination of binders and where the primary aim is to increase the surface strength and reduce the dusting of the paper, namely the production of natural surface-glazed paper, pads and mats for the next surface mouthpiece .

Claims (1)

Sizing mixtures for surface sizing of paper, cardboard and board, characterized in that they contain pigments, further dispersing agents containing alkali metal polyphosphates and polyacrylates in an amount of 0.1 to 1.6% by weight. parts per 100 wt. and the binders comprising modified starches, cellulose derivatives, casein, proteins, polyvinyl alcohol, or synthetic dispersions of 43 to 155 wt. parts per 100hmot. parts of pigments.