Paper laminates comprising tungsten treated titanium dioxide having improved photostability

Abstract

This disclosure relates to a resin-impregnated, opaque, cellulose pulp-based sheet comprising an inorganic particle, wherein the inorganic particle comprises at least about 0.002% of tungsten, based on the total weight of the inorganic particle, and has a photostability ratio (PSR) of at least about 2, as measured by the Ag+ photoreduction rate, and color as depicted by an L* of at least about 97.0, and b* of less than about 4. The disclosure also relates to paper laminates prepared from these resin-impregnated, opaque, cellulose pulp-based sheets.

Description

BACKGROUND OF THE DISCLOSURE[0001]1. Field of the Disclosure[0002]The present disclosure relates to resin-impregnated, opaque, cellulose pulp-based sheet and paper laminates, and more particularly to resin-impregnated, opaque, cellulose pulp-based sheet and paper laminates prepared therefrom comprising tungsten.[0003]2. Background of the Disclosure[0004]Paper laminates are in general well-known in the art, being suitable for a variety of uses including table and desk tops, countertops, wall panels, floor surfacing, tableware and the like. Paper laminates have such a wide variety of uses because they can be made to be extremely durable, and can be also made to resemble (both in appearance and texture) a wide variety of construction materials, including wood, stone, marble and tile, and can be decorated to carry images and colors.[0005]Typically, the paper laminates are made from papers by impregnating the papers with resins of various kinds, assembling several layers of one or more t...

AI Technical Summary

Benefits of technology

[0016]In a first aspect, the disclosure provides a resin-impregnated, opaque, cellulose pulp-based sheet comprising inorganic particles, typically inorganic metal oxide or mixed metal oxide particles, more typically titanium dioxide (TiO2) particles, comprising at least about 0.002% of tungsten, more typically at least about 0.004% of tungsten, and still more typically at least about 0.01% of tungsten, and most typically at least about 0.05% of tungsten, based on the total weight of the inorganic particles, wherein the inorganic particles, have a photostability ratio (PSR) of at least about 2, more typically at least about 4, and still more typically at least 10, as measured by the Ag+ photoreduction rate, and color as depicted by an L* of at least about 97.0, more typically at least about 98, and most typically at least about 99.0, and b* of less than about 4, and more typically less than about 3. Typically the inorganic particles, more typically inorganic metal oxide or mixed metal oxide particles, and most typically titanium dioxide particles, comprising tungsten may further comprise alumina in the amount of about 0.06 to about 5% of alumina, more typically about 0.2% to about 4% of alumina, still more typically about 0.5% to about 3% of alumina, and most typically about 0.8% to about 2%, based on the total weight of the inorganic particles.

[0017]In a second aspect, the disclosure provides a paper laminate comp...

Problems solved by technology

However, the process and materials to be added to improve properties of the titanium dioxide particles may be hazardous.

This is difficult to do with pyrogenically prepared metal oxide particles since the properties of the pyrogenically produced metal oxides change upon contact with a liquid medium.

Images