Optical article with gradient photochromism

Patent metadata

Field	Value
Publication number	US-2016231594-A1
Application number	US-201415023086-A
Country	US
Kind code	A1
Filing date	Sep 19, 2014
Priority date	Sep 20, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

The present invention is drawn to an optical article comprising: (a) a photochromic substrate comprising at least one photochromic dye, and (b) an interference coating having a specific gradient thickness providing for a gradient reflectance. It also pertains to a process for making such an optical article.

First claim

1 . An optical article comprising:
(a) a photochromic substrate having two opposite sides and comprising at least one photochromic dye, wherein said photochromic substrate has a first surface portion and a second surface portion which are located on opposite ends of the same side of said photochromic substrate, (b) an interference coating having a gradient thickness, such that its thickness decreases from a highest thickness region located on said first surface portion to a lowest thickness region located on said second surface portion, wherein the difference between the mean reflectance factor of the highest thickness portion and the mean reflectance factor of the lowest thickness portion, in the wavelength range of from 330 to 380 nm, ranges from 15 to 80%.

2 . The optical article according to claim 1 , wherein the lowest thickness ranges from 80% to 90% of the highest thickness.

3 . The optical article according to claim 1 , which is an ophthalmic lens.

4 . The optical article according to claim 1 , wherein the photochromic substrate is based on polycarbonate, or on a (co)polymer of diethyleneglycol bis(allylcarbonate) or on (meth)acrylic copolymers having a refractive index between 1.54 and 1.58.

5 . The optical article according to claim 1 , wherein the interference coating comprises from 4 to 8 layers, comprising at least two layers with a low refractive index and at least two layers with a high refractive index which are arranged alternately.

6 . The optical article according to claim 1 , wherein the optical article further includes at least one coating selected from: a primer, an anti-abrasion coating, an antistatic layer, an anti-fog topcoat and an anti-fouling topcoat.

7 . The optical article according to claim 1 , wherein the interference coating has throughout its surface a mean reflectance factor, in the wavelength range of from 400 to 700 nm, which is less than 3% and preferably less than 2%.

8 . The optical article according to claim 1 , wherein the thickness of the antireflection coating varies, preferably monotonously, from the highest thickness region to the lowest thickness region, along an axis which is vertical in normal conditions of use of the optical article.

9 . A process for manufacturing an optical article, comprising the successive steps of:
providing a photochromic substrate comprising at least one photochromic dye, placing said substrate in a vacuum deposition chamber equipped with an evaporation device fed with a source material, wherein said evaporation device produces vapor from said source material and orient vapor towards the substrate on which vapor condenses, interposing a mask between said evaporation device and said substrate, on the travel of said vapor, wherein the mask intercepts non uniformly a fraction of vapour to create a gradient thickness of the vapor condensed on said substrate, operating said vacuum deposition chamber until the required gradient thickness is reached.

10 . Spectacles comprising at least one ophthalmic lens comprising:
(a) a photochromic substrate having two opposite sides and comprising at least one photochromic dye, wherein said photochromic substrate has a first surface portion and a second surface portion which are located on opposite ends of the same side of said photochromic substrate, (b) an interference coating having a gradient thickness, such that its thickness decreases from a highest thickness region located on said first surface portion to a lowest thickness region located on said second surface portion, wherein the difference between the mean reflectance factor of the highest thickness portion and the mean reflectance factor of the lowest thickness portion, in the wavelength range of from 330 to 380 nm, ranges from 15 to 80%.

Assignees

• Essilor Int

Inventors

• Ang Ker Chin Dave
• Pelayo Andrew
• De Ayguavives Francisco

Classifications

• G02B5/23

  Photochromic filters · CPC title

• G02B1/111

  using layers comprising organic materials · CPC title

• G02B5/28

  Interference filters · CPC title

• C23C14/24

  Vacuum evaporation · CPC title

• G02C7/102 Primary

  Photochromic filters · CPC title