US 6,013,370 A · Bright metal flake

Abstract

A rigid and brittle bright metal flake is formed of a central layer of a reflective material supported on both sides by dielectric layers. In a preferred embodiment, the metal layer is aluminum having a thickness of about 100 nm and the dielectrics are either silicon dioxide or magnesium fluoride, each having a thickness of about 100 nm. The result is a very thin three-layered metal flake about 300 nm thick that exhibits a uniaxial compressive strength of about 8 times a corresponding uniaxial tensile strength. As a result, the metal flake is then afforded the benefits of rigidity and brittle fracture during the manufacturing and applicational processes which ultimately provides favorable planar and specular reflectance characteristics in the visible wavelength range.

Claims28

Dependent claims

A flake having substantial rigidity so as to provide high reflectance during use as a pigment, said flake comprising:

a reflector layer having a top surface, a bottom surface, and at least one side surface, and having a thickness in a range of about 40 nm to about 150 nm;
and
a dielectric layer on each of the top and bottom surfaces but not on the at least one side surface, each dielectric layer having a thickness in a range of about 50 nm to about 200 nm the thickness chosen so that the dielectric layers do not substantially affect the color properties of the reflector layer.

Dependencies are inferred from the claim text.

Bright metal flake

Life of this patent

Bright metal flake

Life of this patent

Abstract

Claims28