Recording sheet for ink jet printing
View Patent ↗A recording sheet for ink jet printing is described, which consists of a support having coated onto said support at least two ink-receiving layers, wherein the ink-receiving layer situated next to the support contains nanoporous silicon dioxide with a positively charged surface and at least one binder and the ink-receiving layer situated further away from the support contains nanocrystalline, nanoporous aluminium oxide or aluminium oxide/hydroxide and at least one binder and, optionally, nanoporous silicon dioxide with a positively charged surface.
1. Recording sheet for ink jet printing, having coated onto a support at least two ink-receiving layers, each consisting of binders and at least one nanocrystalline, nanoporous compound, wherein the ink-receiving layer situated next to the support contains nanoporous silicon dioxide with a positively charged surface and the ink-receiving layer situated further away from the support contains nanocrystalline, nanoporous aluminum oxide/hydroxide and an intermediate layer without any binder between the two ink-receiving layers.
2. Recording sheet for ink jet printing according to claim 1 , wherein the nanoporous silicon dioxide with a positively charged surface has an average size of the primary particles of at most 20 nm and the aluminum oxide/hydroxide has an average size of the primary particles between 5 nm and 15 nm.
3. Recording sheet for ink jet printing according to claim 1 , wherein the ink-receiving layer situated further away from the support contains, in addition, silicon dioxide with a positively charged surface.
4. Recording sheet for ink jet printing according to claim 3 , wherein the amount of silicon dioxide with a positively charged surface is from 0.5 percent by weight to 15 percent by weight relative to the total amount of nanocrystalline, nanoporous aluminum oxide/hydroxide and silicon dioxide with a positively charged surface in this layer.
5. Recording sheet for ink jet printing according to claim 1 , wherein said intermediate layer consists of nanocrystalline, nanoporous aluminum oxide/hydroxide, nanoporous silicon dioxide with a positively charged surface or a mixture of these compounds.
6. Recording sheet for ink jet printing according to claim 1 , wherein the nanocrystalline, nanoporous aluminum oxide/hydroxide contains one or more of the elements of the rare earth metal series of the periodic system of the elements with atomic numbers 57 to 71 in an amount of from 0.2 mole percent to 2.5 mole percent relative to Al 2 O 3 .
7. Recording sheet for ink jet printing according to claim 1 , wherein the nanoporous silicon dioxide with a positively charged surface is fumed silicon dioxide, and the surface of it has been modified by a treatment with aluminum chlorohydrate, an aminoorganosilane or the reaction products of at least one aminoorganosilane with a compound of trivalent aluminum.
8. Recording sheet for ink jet printing according to claim 1 , wherein the binder is polyvinyl alcohol.
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.