EP1591503A1

Silicone coating compositions and coated articles

Abstract

A silicone coating composition comprising (A) a silicone resin resulting from (co)hydrolytic condensation of an alkoxysilane or a partial hydrolytic condensate thereof, (B) an aromatic-free compound for curing the silicone resin, and (C) a solvent remains stable during shelf storage. It is applied and heat cured to a plastic substrate to form a protective coat having a high hardness, mar resistance, adhesion toughness and crack resistance.

Term

Term ended

Projected expiry passed 21 April 2025, 1.4 years ago.

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10 claims: 4 independent, 6 dependent

  1. 1
    A silicone coating composition comprising (A) silicone resin obtained or obtainable by (co)hydrolytic condensation of at least one member selected from an alkoxysilane and a partial hydrolytic condensate thereof, the alkoxysilane having the general formula:(R 1 ) m (R 2 ) n Si(OR 3 ) 4-m-n wherein R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group, R 3 is an alkyl group of 1 to 3 carbon atoms, m and n are each independently 0 or 1, and m+n is 0, 1 or 2, (B) aromatic group-free compound for curing the silicone resin (A), the compound having the general formula:         [(R 4 )(R 5 )(R 6 )(R 7 )M] + ·X - wherein R 4 , R 5 , R 6 and R 7 are each independently an alkyl group of 1 to 18 carbon atoms which may be substituted with halogen, each of R 4 , R 5 , R 6 and R 7 has a Taft-Dubois steric substituent constant Es, the total of constants Es of R 4 , R 5 , R 6 and R 7 is up to -0.5, M is an ammonium or phosphonium cation, and X - is a halide anion, hydroxide anion or carboxylate anion of 1 to 4 carbon atoms, and (C) a solvent.
  2. 5
    The silicone coating composition of any one of claims 1 to 4, further comprising at least one metal oxide in microparticulate form.
  3. 6
    The silicone coating composition of any one of claims 1 to 5, further comprising at least one UV absorber.
  4. 7
    A coated article comprising    a substrate and    a cured coat of the silicone coating composition of any one of claims 1 to 6 overlying at least one surface of the substrate directly or via at least one layer of different type.
  5. 9
    A coating method comprising forming a coating on a substrate by applying and curing a composition according to any one of claims 1 to 6 on the substrate.
  6. 10
    A method comprising the preparation of a composition according to any one of claims 1 to 6 by combining the mentioned ingredients thereof, optionally including said (co)hydrolysis.