Search

EP-3917993-B1 - MULTI-COAT POLYMER PHOTONIC CRYSTAL FILMS

EP3917993B1EP 3917993 B1EP3917993 B1EP 3917993B1EP-3917993-B1

Inventors

  • PEARSON, Ryan Michael
  • RYAN, MATTHEW DAVID
  • MIYAKE, Garret

Dates

Publication Date
20260513
Application Date
20200130

Claims (15)

  1. A multilayer coating comprising: a) a first layer of a photonic crystal film comprising a pigment and brush block copolymer (BBCP) of Formula IA or Formula IB: or wherein R x is -(C 2 -C 6 )alkyl-OC(=O)G 1 wherein G 1 comprises polyacrylate, polymethacrylate or polylactic acid; R 3 is -(C 1 -C 8 )alkyl-G 2 -G 3 wherein G 2 is -C(=O)O- or a nitrogen heterocycle and G 3 comprises polystyrene, polyacrylate, polydimethylsiloxane, polyether, polymethacrylate, or polylactic acid; R 1 is unbranched alkyl; R 2 is branched alkyl; J 1 and G are each independently CH 2 or C=O; each J 2 is independently CH 2 or C=O; each Q is independently alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl; a and b are each independently 0 to about 1000; and x and y are each independently 1 to about 1000; wherein blocks a, b, x and y are in any order, the ratio of x:a is 1:0 to about 1:3, and the ratio of y:b is 1:0 to about 1:3; and b) a second layer comprising a topcoat wherein the topcoat is an optical adhesive or ultraviolet curable resin; wherein the first layer and second layer form a multilayer film and the multilayer coating comprises one or more multilayer films.
  2. The multilayer coating of claim 1 wherein the pigment is an acid dye, basic dye, azo dye, acridine dye, rylene dye, sulfur dye, pH indicator, food dye, fluorescent brightener, anthraquinone dye, arylmethane dye, triarylmethane dye, phthalocyanine dye, quinone-imine dye, Azin dye, indophenol dye, oxazin dye, oxazone dye, thiazine dye, thiazole dye, safranin dye, xanthene dye, perylene diimide dye, rhodamine dye, or combination thereof.
  3. The multilayer coating of claim 1 wherein a and b are each independently 1 to about 300; or wherein x and y are each independently 1 to about 300.
  4. The multilayer coating of claim 1 wherein the ratio of x:a is about 1:0.5 to about 1:1; or wherein the ratio of y:b is about 1:0.5 to about 1:1.
  5. The multilayer coating of claim 1 wherein BBCP has a number average molecular weight of about 500 kDa to about 3000 kDa; or wherein the weight percent of BBCP is about 50% to about 99.9% and the weight percent of the pigment is about 0.1% to about 10%.
  6. The multilayer coating of claim 1 wherein the photonic crystal film further comprises a metal oxide, a linear polymer additive, or a combination thereof; or wherein the photonic crystal film further comprises zirconium dioxide nanocrystals.
  7. The multilayer coating of claim 1 wherein the BBCP of Formula I is a BBCP of Formula IC or Formula II: or wherein R 3 and R 4 are each independently H or unbranched or branched -(C 1 -C 6 )alkyl; and m and n are each independently 1 to about 100.
  8. The multilayer coating of claim 7 wherein m and n are each independently 10 to about 50.
  9. A method for reducing haze of a substrate comprising coating a substrate with a multilayer coating wherein the multilayer coating comprises: a) a first layer of a photonic crystal film and a pigment; and b) a second layer comprising a topcoat wherein the topcoat is an optical adhesive or ultraviolet curable resin; wherein the first layer modulates the reflectance, absorbance and transmission profile of the substrate wherein at least 5% more electromagnetic radiation is reflected by the coated substrate than for a corresponding uncoated substrate, and the second layer reduces haze of the reflected electromagnetic radiation by at least 5% compared to the corresponding uncoated substrate.
  10. The method of claim 9 wherein the photonic crystal film has an optical thickness f- ratio of about 0.33 to about 0.67.
  11. The method of claim 9 wherein the reflectance, absorbance and transmission profile of the substrate comprises reflected electromagnetic radiation at wavelengths of about 280 nanometers to about 400 nanometers; or the reflectance, absorbance and transmission profile of the substrate comprises reflected electromagnetic radiation at wavelengths of about 400 nanometers to about 700 nanometers; or the reflectance, absorbance and transmission profile of the substrate comprises reflected electromagnetic radiation at wavelengths of about 700 nanometers to about 1600 nanometers.
  12. A method for forming a multilayer coating comprising: a) combining a solvent, a pigment and a brush block copolymer (BBCP) to form a mixture, wherein BBCP is a BBCP of Formula IC: wherein R x is -(C 2 -C 6 )alkyl-OC(=O)G 1 wherein G 1 comprises polyacrylate, polymethacrylate or polylactic acid; R 3 is -(C 1 -C 8 )alkyl-G 2 -G 3 wherein G 2 is -C(=O)O- or a nitrogen heterocycle, and G 3 comprises polystyrene, polyacrylate, polydimethylsiloxane, polyether, polymethacrylate, or polylactic acid; R 1 is unbranched alkyl; R 2 is branched alkyl; a and b are each independently 0 to about1000; and x and y are each independently 1 to about 1000; wherein the ratio of x:a is 1:0 to about 1:3 and the ratio of y:b is 1:0 to about 1:3; b) applying a first layer of the mixture to a substrate; c) drying the first layer to form a film; and d) applying a second layer comprising a topcoat to the film wherein the topcoat is an optical adhesive or ultraviolet curable resin; wherein the film and second layer form the multilayer coating on the substrate.
  13. The method of claim 12 wherein the pigment is an acid dye, basic dye, azo dye, acridine dye, rylene dye, sulfur dye, pH indicator, food dye, fluorescent brightener, anthraquinone dye, arylmethane dye, triarylmethane dye, phthalocyanine dye, quinone-imine dye, azin dye, indophenol dye, oxazin dye, oxazone dye, thiazine dye, thiazole dye, safranin dye, xanthene dye, perylene diimide dye, rhodamine dye, or a combination thereof; or wherein the mixture comprises the pigment in about 0.1% to about 3% by weight.
  14. The method of claim 12 wherein BBCP has a weight percent of about 2.5% to about 50% in the mixture; or wherein BBCP has a number average molecular weight of about 500 kDa to about 3000 kDa.
  15. The method of claim 12 wherein step a) further comprises adding to the mixture a metal oxide, a linear polymer additive, or a combination thereof; or wherein applying a layer of the mixture to a substrate comprises spray deposition, draw-down coating, slot die coating, screen printing, spray deposition, or paintbrush/roller of the mixture to the substrate.

Description

RELATED APPLICATIONS This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62/799,945 filed February 1, 2019. GOVERNMENT SUPPORT This invention was made with government support under Grant No. DE-AR0000881 and DE-AE0001261 awarded by the Department of Energy. The government has certain rights in the invention. BACKGROUND OF THE INVENTION Photonic crystals (PCs) are highly ordered structures composed of materials of differing dielectric constants with a periodicity similar to the wavelengths of light reflected. PCs have found use in thin film optics, reflective coatings on lenses or mirrors, and waveguides. PCs can be made through top down approaches such as lithography, atomic layer deposition or etching. More recently bottom up approaches have been realized through self-assembly mechanisms using colloidal crystals or block copolymers. While top-down approaches provide precise control over the architecture, bottom up approaches offer the advantage of providing an inexpensive means to achieve similar structures and enable rapid prototyping and deposition on a variety of surfaces. Towards an end use application, the challenge of having a robust and transparent photonic crystal coating accessed through a bottom-up strategy still persists. Through self-assembly, it is common that with or without specialized annealing processes, irregularities and errors in the nanoscale morphology are formed. These irregularities, of a large enough size, can result in the phenomena of light scattering as well as inhomogeneous surface features. The current state of the art is represented by multilayer extruded thin films (US Patent Nos. 6,208,466 and 6,696,142) or layer-by-layer deposited metal oxide nanoparticles or polyelectrolytes (Bioinspir. Biomim. 2013, 8, 045005 and US Patent Application Publication No. 2014/0218792). Dong-Po Song et al. disclose "Thermally Tunable Metallodielectric Photonic Crystals from the Self-Assembly of Brush Block Copolymers and Gold Nanoparticles (Advanced Optical Materials, vol. 3, no.9, pages 1169-1175). These approaches require significant investment in advanced manufacturing instrumentation/infrastructure and techniques, in addition to potential high material costs. The reflective properties inherent to the disclosed material are established in a bottom-up process through the self-assembly of BCPs that occur rapidly under easily accessible conditions, i.e. ambient or slightly elevated temperature, atmospheric pressure, and in the presence of oxygen. The self- assembly process avoids the need for specialized manufacturing techniques such as nano-imprint or electron-beam lithography, and layer-by-layer deposition. The polymeric building blocks, polymeric additives, and non-polymeric additives employed in the coating are inexpensive, and in preferred embodiments can be "commodity" materials, maintaining low material cost. Current approaches for the preparation of reflective materials require significant investment in advanced manufacturing instrumentation and techniques and high material costs. Accordingly, there is a need for alternative compositions that allow for more cost-effective preparation of reflective materials and coatings. SUMMARY The disclosure relates to the discovery that the use of inorganic/organic composite materials composed of brush block copolymers (BBCPs) and either inorganic, organic, or some combination of the two, families of additives can allow for modification of the optical features of photonic crystal materials, such as but not limited to: percent reflection (%R), wavelength (nm) of maximum reflection (λmax), and full width at half maximum (FWHM) of the reflection peaks, and haze (%haze) of the overall material. Accordingly, this disclosure provides a multilayer coating comprising: a) a first layer of a photonic crystal film comprising a pigment and brush block copolymer (BBCP) of Formula IA or Formula IB: or wherein Rx is -(C2-C6)alkyl-OC(=O)G1 wherein G1 comprises polyacrylate, polymethacrylate or polylactic acid;Ry is -(C1-C8)alkyl-G2-G3 wherein G2 is -C(=O)O- or a nitrogen heterocycle and G3 comprises polystyrene, polyacrylate, polydimethylsiloxane, polyether, polymethacrylate, or polylactic acid;R1 is unbranched alkyl;R2 is branched alkyl;J1 and G are each independently CH2 or C=O;each J2 is independently CH2 or C=O;each Q is independently alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl;a and b are each independently 0 to about 1000; andx and y are each independently 1 to about 1000; wherein blocks a, b, x and y are in any order, the ratio of x:a is 1:0 to about 1:3, and the ratio of y:b is 1:0 to about 1:3; andb) a second layer comprising a topcoat wherein the topcoat is an optical adhesive or ultraviolet curable resin; wherein the first layer and second layer form a multilayer film and the multilayer coating comprises one or more multilayer films. This disclosure also provides a method for modulating an e