Coating compositions based on fluorine-containing inorganic polycondensates, their production and their use
AssigneeInstitut für Neue Materialien gemeinnützige GmbH
InventorsHelmut Schmidt, Reiner Kasemann, Stefan Bruck
Life of this patent
Estimating the term…
Abstract
A coating composition is disclosed based on polycondensates of hydrolyzable compounds in particular of Si, Al, Ti and/or Zr, whereas at least part of the non-hydrolyzable groups linked to these elements contain in average 2 to 30 fluorine atoms linked to aliphatic carbon atoms. A process for producing such coating compositions is also disclosed. The corresponding cured (transparent) coatings are characterized in particular by a very good adherence to various types of substrates, in particular glass, besides an antiadhesive effect with respect to many different materials.
Claims30
A coating composition comprising a polycondensate of one or more hydrolyzable compounds of at least one element M selected from the group consisting of elements of groups IIIA to VA and groups IIB to IVB of the Periodic Table of Elements having hydrolyzable groups A, at least a portion of said hydrolyzable compounds also having non-hydrolyzable carbon-containing groups B, wherein the total molar ratio of groups A to groups B in said hydrolyzable compounds is from 10:1 to 1:2, and wherein 0.1 to 500 mol. % of said groups B are groups B' which on the average contain 5 to 30 fluorine atoms bonded to one or more aliphatic carbon atoms, where said carbon atoms are separated from said element M by at least two atoms.
A process for preparing a coating composition comprising a polycondensate of one or more hydrolyzable compounds of at least one element M selected from the group consisting of elements of groups IIIA to VA and groups IIB to IVB of the Periodic Table of Elements having hydrolyzable groups A, at least a portion of said hydrolyzable compounds also having non-hydrolyzable carbon-containing groups B, wherein the total molar ratio of groups A to groups B in said hydrolyzable compounds is from 10:1 to 1:2. and wherein 0.1 to 5 mol. % of said groups B are groups B' which on the average contain 5 to 30 fluorine atoms bonded to one or more aliphatic carbon atoms, wherein said carbon atoms are separated from said element M by at least two atoms, wherein said hydrolyzable compounds contain a total possible number of M--OH groups when said hydrolyzable compounds are hydrolyzed with water, comprising the steps of:
- (1) hydrolyzing and precondensing said hydrolyzable compounds containing said hydrolyzable groups B and not containing said groups B' by adding water to said hydrolyzable compounds containing groups B to form a precondensate composition;
- (2) adding said hydrolyzable compounds containing said groups B' to said precondensate composition;
- and
- (3) condensing and hydrolyzing said hydrolyzable compounds containing said groups B' and said precondensate composition by adding water thereto to form said coating composition;
- wherein said adding step is conducted when said condensate composition has a water content not more than 5% by weight based on the total weight of said precondensate composition, and when not more than 50% of said total possible M--OH groups are present in said precondensate composition.
Dependencies are inferred from the claim text.