Refinish coating system and repairing method for automotive resin glazing

摘要

Disclosed is a method for repairing a damaged area of a silicone hard-coat layer on an automotive resin glazing substrate by applying an intermediate coating composition (I) to the damaged area and applying a topcoat coating composition (II) to the intermediate coating composition. The intermediate coating composition (I) contains (A) a reactive siloxane compound and (B) silica. The topcoat coating composition (II) contains (C) an alkoxysilane having a UV-absorbing functional group, (D) a multifunctional alkoxysilane, (E) a reactive siloxane compound, (F) colloidal silica, and (G) phosphoric acid. The method forms a coating having the same appearance and physical properties as the underlying silicone hard-coat layer.

主权项

1. A method for repairing a damaged area of a silicone hard-coat layer on an automotive resin glazing substrate, comprising:
(I) applying an intermediate coating composition to the damaged area, thereby burying irregularities in the damaged area; (II) applying a topcoat coating composition to the intermediate coating composition; and (III) curing both coating compositions,
wherein the intermediate coating composition comprises:
(A) 100 parts by weight of a reactive siloxane compound,(B) 1-50 parts by weight of silica, andhas a viscosity of 1,000 to 200,000 mPa·s, andwherein the topcoat coating composition comprises:
(C) 1-25 parts by weight of an alkoxysilane having a UV-absorbing functional group,(D) 20-70 parts by weight of a multifunctional alkoxysilane,(E) 20-70 parts by weight of a reactive siloxane compound,(F) 1-50 parts by weight of colloidal silica, and(G) 0.5-20 parts by weight of phosphoric acid,
per 100 parts by weight of components (C) to (G) combined.