Recording sheet for ink jet printing
View Patent ↗A method for the preparation of silicium dioxide dispersions is provided, wherein the surface of the silicium dioxide is modified by a treatment with the reaction products, formed in a separate reaction step, of at least one compound of trivalent aluminum or of tetravalent zirconium or a mixture thereof with at least one aminoorganosilane; and the invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.
1. Recording sheet for ink jet printing having coated onto a support at least one ink-receiving layer consisting of at least one binder and at least one dispersion of surface modified silicium dioxide, wherein the surface of the silicium dioxide consists of the reaction products of at least one compound of trivalent aluminum and/or tetravalent zirconium with at least one aminoorganosilane, wherein the aminoorganosilane is selected from the group consisting of N-(ethyl)-aminoisobutyltrimethoxysilane and N-(cyclohexyl)-aminomethyltriethoxysilane or mixtures thereof;
and wherein
a layer of 1 cm thickness of an aqueous solution, prepared at room temperature, of 0.01 moles of aluminum chlorohydrate, 0.02/k moles of aminoorganosilane or a mixture of aminoorganosilanes, 0.01 moles of hydrochloric acid and 0.02 moles of glyoxal, having a final weight of 200 g, and stored for 24 hours at room temperature, shows an absorption increase of less than 0.05 at a wavelength of 400 nm after storage, wherein k is the number of amino groups of the aminoorganosilane or a mean value of the numbers of amino groups of the individual aminoorganosilanes in the mixture of aminoorganosilanes.
2. Recording sheet for ink jet printing according to claim 1 , wherein the binder is selected from the group consisting of polyvinyl alcohol, gelatin, derivatives of polyvinyl alcohol, polyvinylpyrrolidone or mixtures of these compounds.
3. Recording sheet for ink jet printing according to claim 1 , wherein the recording sheet is hardened with boric acid.
4. Recording sheet for ink jet printing according to claim 1 , wherein the recording sheet contains a plurality of ink-receiving layers.
5. Recording sheet for ink jet printing according to claim 4 , wherein each ink-receiving layer contains a fumed silicium dioxide having a different specific surface area.
6. Recording sheet for ink jet printing according to claim 4 , wherein the silicium dioxide used in the different layers has been differently modified with the reaction products of at least one compound of trivalent aluminum and/or tetravalent zirconium with at least one aminoorganosilane and wherein a layer of 1 cm thickness of an aqueous solution, prepared at room temperature, of 0.01 moles of aluminum chlorohydrate, 0.02/k moles of aminoorganosilane or a mixture of aminoorganosilanes, 0.01 moles of hydrochloric acid and 0.02 moles of glyoxal, having a final weight of 200 g, and stored for 24 hours at room temperature, shows an absorption increase of less than 0.05 at a wavelength of 400 nm after storage, wherein k is the number of amino groups of the aminoorganosilane or a mean value of the numbers of amino groups of the individual aminoorganosilanes in the mixture of aminoorganosilanes.
7. Recording sheet for ink jet printing according to claim 4 , wherein the different ink-receiving layers have a different ratio of binder to silicium dioxide.
8. Recording sheet for ink jet printing according to claim 4 , wherein the different ink-receiving layers are hardened with different amounts of boric acid.
9. Recording sheet for ink jet printing according to claim 1 , wherein the support is selected from the group consisting of coated or uncoated paper, transparent or opaque polyester or polypropylene and fibrous textile materials.
10. Recording sheet for ink jet printing according to claim 1 , wherein the recording sheet is manufactured by extrusion coating, air knife coating, doctor blade coating, cascade coating or curtain coating.
11. Recording sheet for ink jet printing according to claim 1 , wherein the compound of trivalent aluminum is selected from the group consisting of aluminum chloride, aluminum nitrate, aluminum acetate, aluminum formiate, aluminum lactate, aluminum chlorohydrate or mixtures of these compounds.
12. Recording sheet for ink jet printing according to claim 1 , wherein the compound of tetravalent zirconium is zirconyl chloride.
13. Recording sheet for ink jet printing according to claim 1 , wherein the silicium dioxide is fumed silicium dioxide.
14. Recording sheet for ink jet printing according to claim 13 , wherein the fumed silicium dioxide has a specific surface area between 20 m 2 /g and 400 m 2 /g.
15. Recording sheet for ink jet printing according to claim 1 , wherein the amount of the compound of trivalent aluminum and/or tetravalent zirconium is from 0.1 to 20 percent by weight relative to the amount of silicium dioxide.