# US 11,299,669 B2 · Color conversion film, method for producing same, back-light unit and display apparatus

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- Number: US 11,299,669 B2
- Document ID: US11299669B2
- Status: Granted
- Kind: B2
- Application number: 15/532,017
- Filed: 2016-02-01
- Published: 2017-09-21
- Granted: 2022-04-12
- Earliest claimed: 2015-01-31
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Dong Mok Shin; Sehwan Son; Hoyong Lee; Byeong In Ahn; Du Hyeon Shin; Nari Kim; Ji Ho Kim; Joo Yeon Seo
- Web page: https://patentgrep.com/patent/US11299669B2

## CPC

- C09K 11/025: {non-luminescent particle coatings or suspension media}
- C09K 11/06: containing organic luminescent materials
- G02F 1/133621: {providing coloured light (G02F1/133617, G02F1/133533 take precedence)}
- C09K 2211/1007: Non-condensed systems
- C09K 2211/1011: Condensed systems
- C09K 2211/1055: with other heteroatoms
- G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light}
- G02F 1/133624: {characterised by their spectral emissions}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

The invention described in the present specification relates to a color conversion film including a resin matrix; and an organic fluorescent substance dispersed in the resin matrix, and absorbing blue or green light and emitting light having a wavelength different from the absorbing light, wherein the resin matrix includes a thermoplastic resin, and the color conversion film has a light emission peak with a FWHM of 60 nm or less, quantum efficiency of 80% or greater and an absorption coefficient of 30,000 M−1cm−1 or greater at a maximum absorption wavelength when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution, a method for preparing the same, and a backlight unit including the color conversion film.

## Claims

### Claim 1

A color conversion film comprising:
a resin matrix; and
an organic fluorescent substance dispersed in the resin matrix, and absorbing blue or green light and emitting light having a wavelength different from the absorbing light,
wherein the organic fluorescent substance has the following Chemical Formula 1:
wherein in Chemical Formula 1,
X1 and X2 are a fluorine group or an alkoxy group,
R1 to R4 are the same as or different from each other, and each independently hydrogen, a halogen group, an alkyl group, an alkoxy group, a carboxyl group-substituted alkyl group, —COOR or a —COOR-substituted alkyl group, and herein, R is an alkyl group,
R5 and R6 are the same as or different from each other, and are each independently a cyano group, a nitro group, an alkyl group, a carboxyl group-substituted alkyl group, or —SO3Na, R1 and R5 may be linked to each other to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring, and R4 and R6 may be linked to each other to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring, and
R7 is an alkyl group; or a haloalkyl group,
wherein the resin matrix includes a thermoplastic resin comprising one or more selected from the group consisting of a polymethyl methacrylate (PMMA) resin a styrene-acrylonitrile (SAN)-based resin, and a polyvinyl alcohol (PVA)-based resin and
wherein the color conversion film has a light emission peak with a full width at half maximum (FWHM) of 60 nm or less, quantum efficiency of 80% or greater and an absorption coefficient of 30,000 M−1cm−1 or greater at a maximum absorption wavelength when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution.

### Claim 2 (depends on 1)

The color conversion film of claim 1, wherein the organic fluorescent substance includes one, two or more types of organic fluorescent substances having a maximum light emission peak in a 510 nm to 680 nm range when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution.

### Claim 3 (depends on 1)

A method for preparing the color conversion film of claim 1, the method comprising:
coating a thermoplastic resin solution comprising the thermoplastic resin in which the organic fluorescent substance is dissolved on a substrate; and
drying the thermoplastic resin solution coated on the substrate.

### Claim 4 (depends on 1)

A method for preparing the color conversion film of claim 1, the method comprising extruding the organic fluorescent substance with the thermoplastic resin.

### Claim 5 (depends on 1)

A backlight unit comprising one or more color conversion films according to claim 1.

### Claim 6 (depends on 5)

The backlight unit of claim 5 comprising two or more color conversion films,
wherein at least one color conversion film has a light emission peak with a FWHM of greater than 60 nm when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution, and
wherein at least one of the color conversion films has a maximum light emission wavelength in a 600 nm to 680 nm range when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution, and at least one of the color conversion films has a maximum light emission wavelength in a 515 nm to 555 nm range when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution.

### Claim 7 (depends on 5)

The backlight unit of claim 5 comprising two or more color conversion films,
wherein at least one of the color conversion films has a maximum light emission wavelength in a 600 nm to 680 nm range when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution, and at least one of the color conversion films has a maximum light emission wavelength in a 515 nm to 555 nm range when irradiating light having a light emission peak at 450 nm, a FWHM of 40 nm or less and monomodal light emission intensity distribution.

### Claim 8 (depends on 5)

A display apparatus comprising the backlight unit of claim 5.