Protective layers produced by UV curing processes

• US 10,495,917 B2
• Filed: 11/16/2016
• Issued: 12/03/2019
• Est. Priority Date: 11/16/2015
• Status: Active Grant

• Current Assignee: Moleculed Ltd.
• Original Assignee: StoreDot Ltd.
• Inventors: Szwarcman, Daniel, Cohen, Elad, Armon, Mor Shmuel, Kuks, Evgenia Liel (Jeny), Schwarz, Rony, Eisurovich, Elena, Aronov, Daniel, Sella, Eran
• Primary Examiner(s): Kosack, Joseph R
• Application Number:
  US15/353,509
• Publication Number:
  US 20170139271A1
• Time in Patent Office: 1,112 Days
• CPC Class Codes: C09B 11/24 Phthaleins containing amino groups ; Phthalanes; Fluoranes; Phthalides; Rhodamine dyes; Phthaleins having heterocyclic aryl rings; Lactone or lactame forms of triarylmethane dyes
• CPC Class Codes: C09B 69/008 Dyes containing a substituent, which contains a silicium atom
• CPC Class Codes: C09B 69/103 containing a diaryl- or triarylmethane dye
• CPC Class Codes: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G03F 7/0007 Filters, e.g. additive colour filters; Components for display devices
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G03F 7/0757 Macromolecular compounds containing Si-O, Si-C or Si-N bonds G03F7/0752 takes precedence
• CPC Class Codes: G03F 7/105 having substances, e.g. indicators, for forming visible images
• CPC Class Codes: H10K 85/611 Charge transfer complexes
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons

Abstract

Color conversion films for a LCD (liquid crystal display) having RGB (red, green, blue) color filters, as well as such displays, formulations, precursors and methods are provided, which improve display performances with respect to color gamut, energy efficiency, materials and costs. The color conversion films absorb backlight illumination and convert the energy to green and/or red emission at high efficiency, specified wavelength ranges and narrow emission peaks. For example, rhodamine-based fluorescent compounds are used in matrices produced by sol gel processes and/or UV (ultraviolet) curing processes which are configured to stabilize the compounds and extend their lifetime—to provide the required emission specifications of the color conversion films. Film integration and display configurations further enhance the display performance with color conversion films utilizing various color conversion elements.

Claims

1. A color conversion film for a LCD (liquid crystal display) having RGB (red, green, blue) color filters, the color conversion film configured to absorb illumination from a backlight source of the LCD and have at least one of a R emission peak and a G emission peak, wherein the color conversion film further comprises a protective coating prepared by a UV curing process;

wherein the conversion film further comprises at least one rhodamine-based fluorescent (RBF) compound selected to absorb illumination from the backlight source of the LCD and have the at least one of a R emission peak and a G emission peak; and

wherein the at least one RBF compound is defined by at least one of Formula 1 and Formula 4;

2. The color conversion film of claim 1, wherein the UV curing process comprises using a mixture in propylene carbonate of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate and triarylsulfonium hexafluoroantimonate salts;

polyether-modified polydimethylsiloxane and 3 -ethyloxetane-3 -methanol.

3. The color conversion film of claim 1, wherein the protective coating is prepared by an acetic anhydride surface treatment and/or a trimethylsilane surface treatment.

4. The color conversion film of claim 1, wherein the color conversion film is produced by at least one of a sol gel process and a UV curing process.

5. An LCD comprising at least one color conversion film of claim 1, wherein the LCD comprises a backlight unit comprising the backlight source and a LCD panel having the RGB color filters, wherein the at least one color conversion film is positioned in the LCD panel and is patterned with respect to a patterning of the RGB color filters to yield a spatial correspondence between film regions with R and G emission peaks and respective R and G color filter.

6. An LCD comprising at least one color conversion film of claim 1, wherein the LCD comprises a backlight unit comprising the backlight source and a LCD panel having the RGB color filters, wherein an intensity of the R and G emission peaks of the at least one color conversion film are adjusted to fine tune a white point of the LCD to be at a center of an expected line of deterioration of the intensity within given LCD specifications.

7. An LCD comprising at least one color conversion film of claim 1, wherein the LCD comprises a backlight unit comprising the backlight source and a LCD panel having the RGB color filters, wherein the RBF compounds in the film are at least partially self-assembled to at least partially provide polarized emission, and wherein the at least one color conversion film replaces at least one polarizer film in the LCD.