Optical films with microstructured low refractive index nanovoided layers and methods therefor

Patent metadata

Field	Value
Publication number	US-2016368019-A1
Application number	US-201615256316-A
Country	US
Kind code	A1
Filing date	Sep 2, 2016
Priority date	Jan 13, 2010
Publication date	Dec 22, 2016
Grant date	—

Abstract

A microstructured article includes a nanovoided layer having opposing first and second major surfaces, the first major surface being microstructured to form prisms, lenses, or other features. The nanovoided layer includes a polymeric binder and a plurality of interconnected voids, and optionally a plurality of nanoparticles. A second layer, which may include a viscoelastic layer or a polymeric resin layer, is disposed on the first or second major surface. A related method includes disposing a coating solution onto a substrate. The coating solution includes a polymerizable material, a solvent, and optional nanoparticles. The method includes polymerizing the polymerizable material while the coating solution is in contact with a microreplication tool to form a microstructured layer. The method also includes removing solvent from the microstructured layer to form a nanovoided microstructured article.

First claim

1 - 21 . (canceled)

22 : A method, comprising:
disposing a coating solution onto a substrate, the coating solution comprising a polymerizable material and a solvent; polymerizing the polymerizable material while the coating solution is in contact with a microreplication tool to form a microstructured layer; and removing solvent from the microstructured layer to form a nanovoided microstructured article.

23 - 24 . (canceled)

25 : The method of claim 22 , wherein the polymerizable material comprises a multifunctional acrylate and a polyurethane oligomer.

26 : The method of claim 22 , wherein the substrate is a light transmissive film, wherein the coating solution further comprises a photoinitiator, and wherein the polymerizing includes transmitting light through the substrate while the coating solution is in contact with the microreplication tool.

27 - 30 . (canceled)

31 : The method of claim 1 , wherein the nanovoided microstructured article has a microstructured surface characterized by a structure height of at least 15 micrometers and an aspect ratio greater than 0.3, and wherein the coating solution has a wt % solids in a range from 45 to 70%.

32 - 39 . (canceled)

Assignees

• 3M Innovative Properties Co

Inventors

• Wolk Martin B
• Kolb William Blake
• Free Michael Benton
• Sherman Audrey A
• Wheatley John A
• Thompson David S
• Stay Matthew S
• Hao Encai

Classifications

• G02B5/0268

  characterized by the fabrication or manufacturing method · CPC title

• B29D11/00865

  Applying coatings; tinting; colouring (printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055) · CPC title

• B05D3/007 Primary

  After-treatment · CPC title

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title

• B05D3/067

  Curing or cross-linking the coating · CPC title