Saturating grade paper
AssigneePPG Industries, Inc.
InventorRoger A. Crawford
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Abstract
Described is a titanium dioxide-containing resin saturable paper sheet in which from about 5 to about 40 weight percent of the titanium dioxide filler is replaced with amorphous precipitated silica having an essentially neutral to slightly alkaline, e.g., 6.5 to 8.5, pH and a medium agglomerate particle size of less than 30 micrometers, e.g., 3 to 10 micrometers. The BET surface area of the silica may vary from about 25 to about 200 m.sup.2 /g, e.g., 50 to 100 m.sup.2 /g. Also described are decorative laminates in which the core of the laminate contains at least one of such saturable paper sheets.
Claims22
A resin saturable paper sheet containing titanium dioxide as the principal filler and from about 5 to about 40 weight percent, basis the titanium dioxide, of amorphous precipitated silica having a BET surface area of between about 25 and 200 square meters per gram, a pH of between about 6 and 9.5 and a median agglomerate particle size of less than about 30 micrometers, said silica containing less than about 1 weight percent of calcium (calculated as calcium oxide).
A resin saturable paper sheet of bleached kraft paper, said paper sheet containing rutile titanium dioxide as the principal filler and from about 10 to about 25 weight percent, basis the titantium dioxide, of amorphous precipitated silica having a BET surface area of between about 50 and 90 square meters per gram, a pH in the range of between about 6.5 and 8.5 and a median agglomerate particle size of between 3 and 10 micrometers, said silica containing less than about 1 weight percent of calcium (calculated as calcium oxide).
In a decorative laminate comprising a core of a least one sheet of titanium dioxide-filled saturable paper sheet that has been impregnated with a synthetic laminating resin composition, the improvement wherein the saturable paper sheet contains from about 5 to about 40 weight percent, basis the titanium dioxide, of amorphous precipitated silica having a BET surface area of between about 25 and 200 square meters per gram, a pH of between 6 and 9.5, and a median agglomerate particle size of less than 30 micrometers, said silica containing less than about 1 weight percent of calcium (calculated as calcium oxide).
Dependencies are inferred from the claim text.