US 2015/0306629 A1 · METHOD OF MAKING POLYESTER FILM WITH A REDUCED IRIDESCENT PRIMER LAYER

Abstract

This invention relates to a highly optically clear, composite film having a predominantly thermoplastic polyester base layer and a primer layer of a polyester and polyurethane blend composition. The base layer preferably has an A/B/C layered structure with a substantially particle-free core layer B of polyester and outer layers A and C of polyester containing nonpolyester, organic and/or inorganic particles. The primer layer is preferably applied to the base layer from solution that is organic solvent-free and is crosslinked using a carbodiimide crosslinking agent. The primer layer and base layer composite can be laminated with a protective layer of primarily acrylic polymer for a solar control film. Various layers of the composite and solar control films can contain effective amounts of functional additives, such as UV light blockers. Polyurethane in the primer, especially in combination with crosslinking by the carbodiimide, provides the acrylic coated polyester base solar control film with notably reduced iridescence and durable adhesion between polyester and acrylic layers in moist and warm service conditions.

Claims7

Dependent claims

-9. (canceled)

A method of making an optically clear reduced iridescent composite film comprising the steps of

(A) providing a dispersion comprising inversely synthesized aliphatic polyurethane particles of size in the range of about 1-100 nm and polyester binder particles of a polyester resin having a softening point lower than 100° C. dispersed in a predominantly aqueous medium comprising carbodiimide crosslinking agent dissolved in water,
(B) providing a base layer comprising a core layer of polyester film of thickness in the range of about 1-500 μm and comprising about 0.1 to 2 wt % of a UV light absorber composition,
(C) depositing a wet coating of the dispersion onto one side of the base layer,
(D) heating the base layer and wet coating effectively to (i) soften the polyester binder, (ii) evaporate substantially all volatile components of the predominantly aqueous medium, and (iii), and activate the crosslinking agent, thereby creating an optically clear film of iridescence-reducing solidified primer layer in contact with the one side of the base layer,
in which the wet coating on the base layer is present in an amount effective to produce a thickness of the solidified primer layer in the range of about 0.03-0.15 μm.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

14/795,276Filed 9 Jul 2015

Priority

25 Dec 2011

Published

29 Oct 2015

Term ends

Not estimatedThe source records don’t support an estimate.

Classification34 codes

C08J 7/043
Coating: improving the adhesiveness of the coatings per se, e.g. forming primers
B05D 5/061
To obtain multicolour or other optical effects: special surface effect
B05D 7/536
Base coat plus clear coat type: each layer being cured, at least partially, separately
B32B 27/08
As the main or only constituent of a layer, which is next to another layer of the same or of a different material: of synthetic resin

Method of making polyester film with a reduced iridescent primer layer

Life of this patent

Method of making polyester film with a reduced iridescent primer layer

Life of this patent

Abstract

Claims7