The invention relates to a titanium dioxide particle with high opacity and UV-greying resistance comprising two silica coats and at least one alumina coat, to a method for the obtaining the same, and to the use of said particle in a method for obtaining a decorative paper laminate or a décor foil. The present invention further pertains a decorative paper laminate or a décor foil containing said coated titanium dioxide particle.

The invention relates to a titanium dioxide particle with high opacity and UV-greying resistance comprising two silica coats and at least one alumina coat, to a method for the obtaining the same, and to the use of said particle in a method for obtaining a decorative paper laminate or a décor foil. The present invention further pertains a decorative paper laminate or a décor foil containing said coated titanium dioxide particle.

According to the invention, in producing coloured cardboard, carbon dioxide is injected and dissolved in a mixture of pulp and at least a sulphur dye, while the mixture is pumped with a delivery pressure higher than 200 kPa out of a first pulp reservoir (11) towards a second pulp reservoir (12), and in such manner that the mixture is acidified by the carbon dioxide to become an acidified coloured pulp mixture (14) with a pH-value between 6.5 and 7.0. The acidified coloured pulp is injected under high pressure out of a pulp duct structure (7) into the second pulp reservoir (12) at a distance of at least 2 meter below a level (15) of the acidified coloured pulp mixture (14) in the second pulp reservoir (12). Accordingly, the invention provides a high-quality colouring of cardboard, wherein environmental problems are prevented.

According to the invention, in producing coloured cardboard, carbon dioxide is injected and dissolved in a mixture of pulp and at least a sulphur dye, while the mixture is pumped with a delivery pressure higher than 200 kPa out of a first pulp reservoir (11) towards a second pulp reservoir (12), and in such manner that the mixture is acidified by the carbon dioxide to become an acidified coloured pulp mixture (14) with a pH-value between 6.5 and 7.0. The acidified coloured pulp is injected under high pressure out of a pulp duct structure (7) into the second pulp reservoir (12) at a distance of at least 2 meter below a level (15) of the acidified coloured pulp mixture (14) in the second pulp reservoir (12). Accordingly, the invention provides a high-quality colouring of cardboard, wherein environmental problems are prevented.

A method for obtaining a fibrous preparation for manufacturing a paper having significant water repellency and opacity in the dry or wet state. Fibres are suspended in water; calcium salts are added to the fibres; a source of carbonate salts in the form of an aqueous solution are added and the resulting mixture is stirred for a time sufficient to allow calcium carbonate particles to be precipitated. A solution of fatty acid salts heated to a temperature which corresponds to the micellisation temperature of said fatty acid salts is added and takes into account the critical micellar concentration of the fatty acid salts. The mixture is stirred thus obtained for a time sufficient to allow the fatty acids to be absorbed at the surface of the calcium carbonate particles and to obtain the desired fibrous preparation.

A method for obtaining a fibrous preparation for manufacturing a paper having significant water repellency and opacity in the dry or wet state. Fibres are suspended in water; calcium salts are added to the fibres; a source of carbonate salts in the form of an aqueous solution are added and the resulting mixture is stirred for a time sufficient to allow calcium carbonate particles to be precipitated. A solution of fatty acid salts heated to a temperature which corresponds to the micellisation temperature of said fatty acid salts is added and takes into account the critical micellar concentration of the fatty acid salts. The mixture is stirred thus obtained for a time sufficient to allow the fatty acids to be absorbed at the surface of the calcium carbonate particles and to obtain the desired fibrous preparation.

A fiber is provided as a substrate for a functional nanostructure (coated fiber), composed of (a) a fiber substrate; (b) a reactive dye conjugating moiety covalently bound to the fiber substrate; (c) a bonding agent covalently bound to the reactive dye conjugating moiety; and (d) the functional nanostructure bound to the bonding agent. A method of making the coated fiber is also provided, involving the following steps in any order: covalently binding the reactive dye conjugating moiety to the fiber; covalently binding a bonding agent to the reactive dye conjugating moiety; and binding the functional nanostructure to the bonding agent. The nanostructures are tenaciously attached to the fibers, resisting very rough treatments, and can be made using inexpensive and widely available reactive dyes under non-stringent synthesis conditions.

Paper products can be made from cellulose derived from corn husks. A method of making paper products may include obtaining corn husks, extracting cellulose fiber pulp from the corn husks, forming a paper sheet from the extracted cellulose fiber pulp, adding a chitosan acetic acid solution having a concentration of at least 5 wt. % chitosan to the paper sheet, forming the paper product from the paper sheet, and coating the paper product with a paraffin wax.

Paper products can be made from cellulose derived from corn husks. A method of making paper products may include obtaining corn husks, extracting cellulose fiber pulp from the corn husks, forming a paper sheet from the extracted cellulose fiber pulp, adding a chitosan acetic acid solution having a concentration of at least 5 wt. % chitosan to the paper sheet, forming the paper product from the paper sheet, and coating the paper product with a paraffin wax.

The instant invention relates to liquid sizing compositions comprising shading dyestfuffs, derivatives of diaminostilbene, binders, protective polymers, and optionally divalent metal salts which can be used for the optical brightening of substrates, including substrates suitable for high quality ink jet printing.