PEARLESCENT PIGMENTS HAVING A SECONDARY COATING COMPRISING -SILANES AND METHOD FOR THE PRODUCTION THEREOF

• Main Authors: SCHMIDT, ULRICH, KAUPP, GUENTER
• Format: Patent
• Language: English; French; German
• Published: 02.04.2008
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; CORRECTING FLUIDS; DYES; FILLING PASTES; HUMAN NECESSITIES; HYGIENE; INKS; MEDICAL OR VETERINARY SCIENCE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; POLISHES; PREPARATION OF CARBON BLACK; SPECIFIC USE OF COSMETICS OR SIMILAR TOILETPREPARATIONS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; USE OF MATERIALS THEREFOR; WOODSTAINS

Pigment (A) with a nacreous luster comprises (i) a platelet-shaped substrate (B), containing a metal oxide (MO) with refractive index over 1.8 and (ii) two protective layers (PL). Pigment (A) with a nacreous luster comprises (i) a platelet-shaped substrate (B), containing a metal oxide (MO) with refractive index over 1.8 and (ii) two protective layers (PL). The first PL (PL1) comprises one or more of cerium oxide, hydrated Ce oxide and Ce hydroxide and PL2 is essentially, particularly entirely, of silica, and optionally between PL1 and PL2 there is an additional layer of metal oxide, different from PL1 or 2. PL2 is provided with an organic post-coating (PC) that includes at least one alpha -silane of formula (I), bonded through at least one O atom to PL2. -O (4-n-m)-Si(R 1>) m(CH 2Y) n(I) m : 0-2; n : 1-3 with n + m = 1-3; each R 1>H, Si-C bound 1-20C hydrocarbyl or 1-15C hydrocarbyloxy, optionally having one or more, non-adjacent, CH 2replaced by O, CO, COO, OCO, OCOO, S or NR x>and one or more non-adjacent methine replaced by -N=, -N=N- or -P=; R x>H or 1-15C linear, branched and/or cyclic hydrocarbyl or aryl; Y : functional group that is reactive with a binder system. An independent claim is included for a method for preparing (A).