KAOLIN PIGMENTS, THEIR PREPARATION AND USE

• Main Authors: GOLLEY, CHRISTOPHER R. L, HUSBAND, JOHN CLAUDE, BROWN, HARRY VINCENT JR, PANFIL, DANIEL JOHN
• Format: Patent
• Language: English; French
• Published: 12.10.2000
• Edition: 7
• Subjects: ADHESIVES; ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; DYES; IMPREGNATING OR COATING OF PAPER; INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OFSOLID INORGANIC COMPOUNDS; INORGANIC CHEMISTRY; LIME, MAGNESIA; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; POLISHES; PREPARATION OF CARBON BLACK; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; REFRACTORIES; SLAG; TEXTILES; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES; TREATMENT OF NATURAL STONE

A pigment product suitable for use in a coating composition to provide a glo ss coating on paper, the pigment product comprising a processed particulate kaolin produced from a naturally platy kaolin clay having a particle size distribution such that about 50 % to 60 % by weight of the particles have an esd less than 2 .mu.m and less than 25 % by weight of the particles have an esd less than 0.25 .mu.m and a shape factor of at least 15. This platy clay can be blended with b-fraction clay component. In processing, the crude kaol in is ground to a shape factor greater than 50 to produce even greater "platy" clay. The pigment product has a particle size distribution such that at leas t 80 % by weight of the particles have an esd less than 2 .mu.m and greater th an 12 % and less than 35 % by weight of the particles have an esd less than 0.2 5 .mu.m and whose surface area is greater than 12 m2/g when measured by the BE T method.