Method of forming bright metallized film laminate

Abstract

Disclosed is a method for forming a bright metallized laminate. In one aspect, the method includes press polishing a polyvinylidene difluoride-containing film, either before or after the deposition of a discontinuous layer of indium islands, so that the polyvinylidene difluoride-containing film becomes microscopically smooth. In another aspect, the method includes applying a thermoplastic leveling layer to a polyvinylidene difluoride-containing film and thereafter depositing a discontinuous layer of indium islands upon the thermoplastic leveling layer.

Description

[0001] This application is a divisional application of copending U.S. application Ser. No. 09 / 268,085, filed Mar. 12, 1999, which is hereby incorporated herein by reference.[0002] The invention relates to bright film technology. In particular, the invention is a bright metallized film laminate that has superior optical and deformation properties. In a preferred embodiment, the film laminate includes a layer of discontinuous indium islands deposited on a polyvinylidene difluoride-acrylic alloy film. The invention is also an improved method of making bright metallized film laminates.[0003] Metallized polymeric finishes can be used to complement and even replace bright, reflective metal surface treatments, particularly chrome plating. Polymeric structures having metallized finishes are commonly used as substitutes for articles, such as automobile grills, that are expected to have a chrome-plated appearance. Decorative polymeric components, in fact, are becoming standard in the automobi...

AI Technical Summary

Benefits of technology

[0013] Therefore, it is an object of the present invention to provide a bright metallized film laminate having superior optical and deformation properties, and a method of making such film laminates.

[0014] In its broadest form, the invention comprises a metallized formable laminate made of a discontinuous layer of indium islands deposited on a microscopically smooth film formed of an alloy containing polyvinylidene difluoride (PVDF) and an acrylate polymer. In the preferred embodiments the film is the FLUOREX.RTM.-brand fluoropolymer (Rexam, Inc., Matthews, N.C.) in which the polyvinylidene difluoride film includes about 25 percent acrylic component. This indium-FLUOREX.RTM. combination has superior, quantifiable optical and deformation properties as compared to other bright, formable films.

[0015] In another aspect, the invention includes an adhesive layer placed on the surface of the discontinuous indium layer opposite the PVDF-acrylate (or "acrylic") film. A thermoplastic layer is then placed on the adhesive. Such a thermoplastic layer may be comprised of polyvinyl chloride (PVC), thermoplastic olefin (TPO), polycarbonates (PC), or acrylonitrile-butadiene-styrene (ABS) copolymer. The adhesive layer prevents the undesirable formation of indium oxide (In.sub.2O.sub.3), a whitish, unreflective compound. Moreover, when the thermoplastic layer includes polyvinyl chloride, the adhesive layer helps to prevent chloride ion or hydrochloric acid from reacting with the indium layer to form indium trichloride (InCl.sub.3), an unreflective compound.

Problems solved by technology

This necessitates drying time for each application, which lengthens the processing times associated with metallizing three-dimensional articles.

Therefore, depositing metal directly onto an article only after the article has been formed can be disadvantageous.

Such laminates also facilitate customized application, limited only by adhesive effectiveness.

Moreover, using a metallized film laminate reduces chemical compatibility problems that can arise between the metal and the polymeric substrate when metallizing articles in-situ.

Using such metallized film laminates, though convenient, can result in an inferior finish as compared to that obtained by in-situ techniques.

Such formable film laminates have poor flexibility, however, often cracking when the metallized substrates are excessively deformed.

Moreover, such moldable films tend to lose luster over time.

This is particularly pernicious with respect to metallized indium layers, which in the presence of halogen-containing polymers (e.g., polyvinyl chloride, "PVC") can undergo an oxidation-reduction reaction that converts elemental indium to indium trichloride.

Finally, to the extent such moldable films are formed from continuous metallized layers, corrosion problems result.

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