Process and apparatus for a nanovoided article

• US 8,808,811 B2
• Filed: 03/26/2010
• Issued: 08/19/2014
• Est. Priority Date: 04/15/2009
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Kolb, William Blake, Hao, Encai, Kolb, Brant U., Phillips, David L.
• Primary Examiner(s): LIGHTFOOT, ELENA TSOY
• Application Number:
  US13/262,933
• Publication Number:
  US 20120027945A1
• Time in Patent Office: 1,607 Days
• Field of Search: 427/508, 427/245, 427/510
• US Class Current: 427/508
• CPC Class Codes: C08J 2201/05 Elimination by evaporation or heat degradation of a liquid phase
• CPC Class Codes: C08J 2333/06 of esters containing only carbon, hydrogen, and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: F26B 13/10 Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials heating processes F26B3/00

Abstract

A process and apparatus for producing a nanovoided article, a nanovoided coating, and a low refractive index coating is described. The process includes providing a first solution of a polymerizable material in a solvent; at least partially polymerizing the polymerizable material to form a composition that includes an insoluble polymer matrix and a second solution, wherein the insoluble polymer matrix includes a plurality of nanovoids that are filled with the second solution; and removing a major portion of the solvent from the second solution. An apparatus for the process is also described, and includes a webline, a coating section, a partial polymerization section, and a solvent removal section.

Claims

1. A process for producing a nanovoided coating, comprising:

coating a first solution comprising a polymerizable material in a solvent onto a substrate;

at least partially polymerizing the polymerizable material using ultraviolet (UV) radiation produced by at least one light emitting diode (LED) to form an insoluble polymer matrix bicontinuous with a plurality of nanovoids and a second solution, the plurality of nanovoids being filled with the second solution; and

removing a major portion of the solvent from the second solution,

wherein the first solution further comprises nanoparticles, at least some of the nanoparticles becoming bound to the insoluble polymer matrix during the polymerizing step, and a weight ratio of polymerizable material to the nanoparticles is greater than about 30;

70.

2. The process of claim 1, wherein the nanoparticles comprise surface modified nanoparticles.

3. The process of claim 2, wherein the surface modified nanoparticles comprise reactive nanoparticles, non-reactive nanoparticles, or combinations thereof.

4. The process of claim 3, wherein a substantial portion of the reactive nanoparticles form a chemical bond with the insoluble polymer matrix.