COLOUR CHANGING MEDIA FOR LIGHT EMITTING DISPLAY DEVICES The present invention relates to electroluminescent elements comprising an organic or inorganic electroluminescent material part which emits a blue light and at least one fluorescent material part which absorbs said blue light and emits a fluorescence in a visible light range from bluish green to red light said fluorescent material part exists outside of the electroluminescent material part and comprises a diketopyrrolopyrrole compound.

Organic electroluminescent devices, also known as organic light emitting diode ("OLED") devices, have been known for approximately two decades. All OLEDs work on the same general principles. One or more layers of semi-conducting organic material are sandwiched between two electrodes, an anode and a cathode. An electric current is applied to the device, causing electrons to move into the organic material (s) from the cathode and positive charges, typically referred to as holes, to move into the organic material (s) from the anode.

The positive and negative charges recombine in the electroluminescent medium (i. e. , the emitter layer) and produce photons. The wavelength of the photons, and consequently the color of the emitted light, depends on the electronic properties of the organic materials in which the photons are generated.

Therefore, the color of light emitted from an OLED device may be controlled by the selection of the organic materials in the emitter layer. Specifically, the precise color of emitted light can be controlled by the selection of host materials and dopants in the emitter layer. In addition, color filters and color changing media may be used to alter the color of light emitted from the emitter layer of an OLED.

An OLED display may be monochromatic, that is, each pixel comprising the display emits light of the same color. Alternatively, various pixels of an OLED display may emit different colors. A full-color OLED display is formed from an array of pixels comprising a red, a green and a blue sub-pixel. The sub-pixels in any particular pixel can be activated in various combinations to generate an entire spectrum of colors.

A second approach for making full-color OLED displays employs OLEDs that emit white light combined with color filters that are precisely aligned over each OLED. Certain wavelengths of light are filtered out by the filters, with the result that the various color filters generate red, green and blue light for the sub-pixels. The use of color filters can be inefficient, however, because the filters inevitably absorb some light.

A third approach for making full-color OLED displays is to use a monochromatic OLED array with color changing materials (instead of color filters) aligned on top of the pixels. Color changing materials work by absorbing light of shorter wavelength (e. g., blue light) and then emitting light of longer wavelength by fluorescence or phosphorescence (photoluminescence) (e. g. , red or green light). The use of color changing materials is known in the art (see e. g., US-B-5,126, 214 (Idemitsu Kosan Co. , Ltd. ) and US-B-5,294, 870 (Eastman Kodak Co. )).

All pixels emit the same color and the filter media can be patterned and aligned with each OLED to form the different color sub-pixels. When the relevant layers have high quantum efficiency of photoluminescence and internal losses are minimized, the third approach provides higher efficiency.

Nevertheless, the use of color changing materials also has drawbacks. Most materials used as color changing materials have broad emission photoluminescence spectra that require the use of optical filters for spectral correction, i. e. , to insure that each sub-pixel emits red, green or blue light in a narrow wavelength range. The use of optical filters in addition to the color changing materials may introduce additional loss of intensity of emitted light.

There is clearly a need for a color changing materials for high-resolution, full-color OLED display devices.

Accordingly the present invention relates to an electroluminescent element comprising an organic or inorganic efectrotuminescent material part which emits a bfue fight and at feast one fluorescent material part which absorbs said blue light and emits a fluorescence in a visible light range from bluish green to red light said fluorescent material part exists outside of the electroluminescent material part and comprises a diketopyrrolopyrrole compound.

The diketopyrrolopyrrole compounds are characterized by a high absorption coefficient and a high fluorescence quantum yield.

The diketopyrrolopyrrole is generally a compound of formula

R'and R2 are independently of each other an organic group, and Ar1 and Ar2 are independently of each other an aryl group or an heteroaryl group, which can be substituted.

R'and R2 may be the same or different and are preferably selected from a C-C25alkyl group, which can be substituted by fluorine, chlorine or bromine, an allyl group, which can be substituted one to three times with C1-C4alkyl, a cycloalkyl group, or a cycloalkyl group, which can be condensed one or two times by phenyl which can be substituted one to three times with C1-C4-alkyl, halogen, nitro or cyano, an alkenyl group, a cycloalkenyl group, an alkynyl group, a haloalkyl group, a haloalkenyl group, a haloalkynyl group, a group Y-R32, a silyl group, a siloxanyl group, -X2-X3, A2 or -CR73R74-(CH2)m-A2, wherein R73 and R7 independently from each other stand for hydrogen or C1-C4alkyl, or phenyl which can be substituted one to three times with C1-C4alkyl, Y, R32, X2 and X3 are as defined below, and A2 stands for aryl or heteroaryl, in particular phenyl or 1-or 2-naphthyl which can be substituted one to three times with C1-C8alkyl and/or Ci-Csaikoxy, and m stands for 0,1, 2,3 or 4.

Ar1 and Ar2 can be different, but preferably have the same meaning.

If Ar1 and Ar2 are an aryl group, they are preferably a group of formula

R55, R56, and R57 independently from each other stands for hydrogen, Cq-C25-alkyl, Ci-C25- alkoxy, -Cr61R62-(CH2)m-A1, cyano, halogen,-oR59,-S (O) pR60, -X1-X2-X3, or phenyl, which can be substituted one to three times with C,-C8alkyl or Ci-Csa ! koxy, wherein A'stands for aryl or heteroaryl, in particular phenyl or 1-or 2-naphthyl, which can be substituted one to three times with C1-C8alkyl and/or C1-C8alkoxy, e stands for C2-C2o-heteroaryl, or C6-C24-aryl, R59 stands for C1-C25-alkyl, C5-C12-cycloalkyl, -CR61R62-(CH2)m-Ph, C6-C24-aryl, or a saturated or unsaturated heterocyclic radical comprising five to seven ring atoms, wherein the ring consists of carbon atoms and one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur, R60 stands for C1-C25-alkyl, C5-C12-cycloalkyl, -CR61R62-(CH2) m-Ph, R61 and R62 independently from each other stand for hydrogen, fluorine, chlorine, bromine, cyano or C1-C4alkyl, which can be substituted by fluorine, chlorine or bromine, or phenyl which can be substituted one to three times with Ci-C4alkyl, p stands for 0,1, 2 or 3, m and n stands for 0,1, 2,3 or 4, or Ar1 and Ar2 independently from each other stand for R63 and R64 independently from each other stand for hydrogen, or C6-C24-aryl, in particular phenyl, R65 and R66 independently from each other stands for hydrogen, Ci-C25-alkyl, Ci-C25- alkoxy, -CR61R62-(CH2)m-A1, cyano, halogen, -OR59, -S(O)pR60, -X1-X2-X3, or phenyl, which can be substituted one to three times with C1-C8alkyl or C1-C8alkoxy, R68 and R69 independently from each other stand for hydrogen, Cl-C25-alltyl, C5-cl2- Cycloalkyl, -CR61R62-(CH2)m-A1, C6-C24-aryl, in particularA', or a saturated or unsaturated heterocyclic radical comprising five to seven ring atoms, wherein the ring consists of carbon atoms and one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur, or R68 and R69 together with the nitrogen atom to which they are bonded form a five or six membered heterocyclic ring which can be condensed by one or two optionally

R661 R66 N'-o I I substituted phenyl groups, such as, wherein A', R5, R'O, R6', R62, p and m are as defined above and X', X2 and X3 are as defined below.

Fluorescent diketopyrrolopyrroles (including compositions and polymers) of formula 1, which are suitable for the use as color changing material, are known and are described, for example, in EP-A-0133156, US-A-4, 585,878, EP-A-0353184, EP-A-0787730, W098/25927, US-A-5,919, 944, EP-A-0787731, EP-A-0811625, W098/25927, EP-A-1087005, EP-A- 1087006, W003/002672, W003/022848, PCT/EP03/00650, PCT/EP03/07638, and PCT/EP2004/050403, H. Langhals et al. Liebigs Ann. 1996,679-682 : Abs. (nm) Fluores. (nm) Ar'=Ar'R'=R' [CHOs] [CHOs] phenyl phenyl 464, 484 520, 555 (sh) phenyl 4-methylphenyl 470, 488 521, 549 (sh) phenyl 2, 3-dimethylphenyl 469,492 524, 555 (sh) phenyl 4-t-bu-phenyl 467, 489 519, 553 (sh) phenyl phenyl & 4-t-bu-phenyl 467, 489 521,560 (sh) US-A-5, 354, 869 : Ar1 = Ar2 R1 = R2 Abs. (nm) Fluores. (nm) 2-methoxyphenyl methyl 454 514 2-methoxyphenyl & phenyl methyl 464 518 In a preferred embodiment, the diketopyrrotopyrrote compound is a compound the absoption peak of which is in the range of from about 440 to about 490 nm, especially of from about 450 to about 480 nm, and which shows photoluminescence the peak of which is in the range of from about 510 to about 550 nm, especially from about 520 to about 540 nm, i. e. a blue-to- green color changing material (A) ("blue-to-green CCM").

In said embodiment, the diketopyrrolopyrrole is preferably a compound of formula

R'and R2 are independently of each other a Ci-24-alkyl group, a C224-alkenyl group, Ar7, especially phenyl which can be substituted up to three times with C,-C8alkyl, or a group of formula-CR3°R31-(CH2) m-Ar7 or Y-R32, wherein R30 and R3'independently of each other stand for hydrogen, or C1-C4alkyl, or phenyl which can be substituted up to three times with C1- C4alkyl, Ar7 stands for aryl, C5-C8cycloalkyl, Cs-C8cycloalkenyl or heteroaryl, which can be substituted one to three times with C1-C8alkyl, C1-C8alkoxy, cyano, halogen or phenyl, which can be substituted with Ci-Cgatkyi or Ci-Cgaikoxy one to three times, m stands for 0,1, 2,3 or 4, Y is -C (O)-,-C (O) O-,-C (O) NH-,-SO2NH-or-SO2-and R32 is C1-C18alkyl, Ar7, or aralkyl, or R1 and R2 are independently of each other a group -X2-X3, Ar1 and Ar2 are independently of each other a group of formula

R3, R4 and Rs are independently of each other a hydrogen atom, a C1-C18-alkyl group, a Ci- Dus-alkoxy group, a fluorine atom, a chlorine atom, or a group -X1-X2-X3, wherein X1 is -O-, -S-, -NH-, -CONH-, -COO-, -SO2-NH-, or -SO2-O-, X2 is an alkylene, arylene, aralkylene or cycloalkylene spacer containing optionally one or more groups -O-, -S-, -NR14-, -CO-, -CONH-, -CONR15-, or -COO- as linking bridge, X3 is OH, NH2, -C (R11) =CH2, -OC(O)-C(R12)=CH2, -C(O)-C(R12)=CH2, C5-C7cycloalkenyl,

-OC(O)-N-X4-N-C(O)-O-X5-O-C(O)-C(R12)=CH2; wherein R11 is hydrogen, C1-C4alkyl, or halogen, R12 is hydrogen, C1-C4alkyl, or halogen, R13 is hydrogen, C1-C4alkyl, or C6-C12aryl, R14 and R15 are independently of each other hydrogen, C,-C8alkyl, or C6-C12aryl, and X4 and X5 are independently of each other an alkylen, arylene, aralkylene or cycloalkylene spacer.

Ar1 and Ar2 are preferably the same and selected from the following groups:

R81, R82 and R84 are a hydrogen atom and R83 is a C1-8-alkyl group, a fluorine atom, or a chlorine atom, or R83, R82 and R84 are a hydrogen atom and R81 is a C18-alkoxy group, or R83, R81 and R84 are a hydrogen atom and R82 is a C1-8-alkoxy group, or a C1-8-alkyl group, or R82 and R84 are a chlorine atom and R81 and R83 are a hydrogen atom, and R85 is a Ci-8-alkyl group.

The following compounds are especially preferred: Abs. Flores. Cpd. Ar1 = Ar2 R1 = R2 (nm) (nm) A-1 3-methylphenyl 1-phenylethyl 460 520 A-2 phenyl 1-phenylethyl 464 520 A-3 4-methylphenyl 1-phenylpropyl 462 521 A-4 4-methylphenyl diphenylmethyl 463 521 A-5 4-methylphenyl 1-phenylethyl 464 521 A-6 3-methoxyphenyl 1-phenylethyl 466 522 A-7 phony) 3-chlorobenzyl 466 3-methylphenyl 3-methylbenzyl 470 527 A-9 3-methylphenyl 3, 5-di-t-butylbenzyl 470 527 4-methylphenyl 3,5-di-t-butylbenzyl 471 527 A-11 3-methylphenyl 3, 5-dimethylbenzyl 472 528 A-12 4-methylphenyl 3-methoxybenzyl 475 528 A-13 phenyl 3, 5-di-t-butylbenzyl 470 529 A-14 4-methylphenyl 4-t-butylbenzyl 474 529 A-15 4-methylphenyl 3-methylbenzyl 474 529 A-16 4-methylphenyl 4-phenylbenzyl A-17 4-methylphenyl 2-methylbenzyl 486 529 A-18 phenyl n-hexyl 470 530 A-19 3-methoxyphenyl 3-chlorobenzyl 473 530 A-20 4-methylphenyl 3, 5,-dimethylbenzyl 474 530 A-21 4-ethylphenyl 3-methylbenzyl 474 530 A-22 4-ethylphenyl 3, 5-di-t-butylbenzyl 474 530 A-23 3-methoxyphenyl 3, 5-di-t-butylbenzyl 475 530 A-24 4-methylphenyl 4-methylbenzyl 476 530 A-25 3-methylphenyl allyl 477 530 A-26 4-i-propylphenyl benzyl 478 530 A-27 4-i-propylphenyl 3, 5-di-t-butylbenzyl 471 531 A-28 4-ethylphenyl benzyl 474 531 A-29 4-methylphenyl 2-naphthylmethyl 474 531 A-30 3-methoxyphenyl 3-methylbenzyl 476 531 A-31 4-i-propylphenyl 3, 5-dimethylbenzyl 476 531 A-32 4-t-butylphenyl 3, 5-di-t-butylbenzyl 477 531 A-33 4-ethylphenyl 3, 5-dimethylbenzyl 478 531 A-34 4-methylphenyl 2-phenylbenzyl 479 531 - (CH2) 60C (O) A-35 phenyl C (CH3) =CH2 470 532 A-36 4-t-butylphenyl benzyl 476 532 A-37 4-i-propylphenyl 3-methylbenzyl 476 532 A-38 3-methoxyphenyl 3, 5-dimethylbenzyl 478 532 A-39 3-methoxyphenyl allyl 478 532 A-40 4-t-butylphenyl 3-methylbenzyl 480 532 A-41 phenyl -(CH2)6-OH 470 533 A-42 3-methylphenyl 3-methyl-2-buten-yl 474 533 A-43 4-t-butylphenyl 3,5-dimethylbenzyl 484 533 A-44 4-methylphenyl methyl 485 533 A-45 4-methylphenyl n-butyl 475 534 A-46 3- (4-phenyl) phenyl 3, 5-dimethylbenzyl 477 534 A-47 phenyl methyl 483 534 A-48 4-chlorophenyl 3, 5-di-t-butylbenzyl 476 536 A-49 1-naphthyl ethyl 443 538 A-50 1-naphthyl n-butyl 447 538 A-51 1-naphthyl n-C12H25 447 538 A-52 1-naphthyl n-C18H37 450 543 3- (4-methyl- A-53 phenyl) phenyl ethyl 478 537 A-54 3, 5-di-chlorophenyl 3, 5-dimethylbenzyl 442 532 A-55 2-methoxyphenyl 3, 5-dimethylbenzyl 443 519 A-56 1-naphthyl acetyl 439 524 A-57 1-naphthyl benzoyl 448 531 A-58 1-naphthyl n-hexyl 447 538 A-59 1-naphthyl-(CH2) e-OH 449 539 -(CH2)6OC(O) A-60 1-naphthyl C (CH3) =CH2 449 539 A-61 4-methylphenyl n-hexyl 475 534 A-62 4-methylphenyl-(CH2) 6-OH 475 536 A-63 4-methylphenyl -(CH2)6OC(O) C (CH3) =CH2 475 536 A-64 3-methoxyphenyl I n-hexyl 478 536 A-65 4-t-butylphenyl n-hexyl 480 537 A-66 3-methylphenyl n-hexyl 474 536 and the following compounds are most preferred : Cpd. Ar1 = Ar2 R1 = R2 Abs. Fluores. A-18 phenyl n-hexyl 470 530 A-35 phenyl- (CH2) 60C (O) C (CH3) =CH2 470 532 A-45 4-methylphenyl n-butyl 475 534

The light-emitting compounds I usually exhibit a fluorescence quantum yield ("FQY') in the range of from 1 > FQY # 0. 3 (measured in toluene). Further, in general, the compounds I exhibit a molar absorption coefficient in the range of from 5000 to 100000. The molar absorption coefficient and quantum yield of exemplary compounds of formula I are shown below : Cpd. Abs. ] Fluores. A-1 11748 0.85 A-2 12646 0.69 A-3 19299 0.56 A-4 8751 0.59 A-5 19111 0. 71 A-6 10418 0.67 A-7 20279 0.65 A-8 21046 0.65 A-9 11187 0.80 A-10 15458 0.80 A-11 20396 0. 57 A-12 13949 0.65 A-13 17821 0.50 A-14 23059 0.67 A-15 10307 0.71 A-16 20865 0.65 A-17 20145 0.65 A-19 24548 0. 77 A-20 21670 0. 61 C d. Abs. E Fluores. A-21 21201 0.52 A-22 21563 0.53 A-23 16466 0.75 A-24 22318 0.60 A-25 19210 0.50 A-28 22496 0.55 A-29 19201 0.67 A-30 16909 0.65 A-32 19197 0.61 A-33 22376 0.51 A-34 21483 0.65 A-36 22447 0.53 A-38 19221 0.54 A-39 18685 0.51 A-40 22556 0.55 A-42 16282 0.57 A-43 19545 0. 54 A-48 20945 0.65

The absorbance spectra are measured on a U-3300 spectrophotometer (Hitachi, Ltd. ) and the fluorescence spectra on a F-4500 Fluorescence spectrophotometer (Hitachi, Ltd. ). The measurements are carried out with a solution of toluene containing 0.1-0. 05 % by weight of the DPP compounds.

In a further embodiment, the diketopyrrolopyrrole compound is a compound the absorption of which is in the range of from about 440 to about 500 nm, especiatty in the range of from about 450 to about 490 nm, and which shows photoluminescence the peak of which is in the range of from 530 to 570 nm, especially in the range of from 540 to 570 nm, and is used in combination with a fluorescent compound the absorption peak of which is in the range of from about 530 to about 570 nm and which shows photoluminescence the peak of which is in the range of from about 580 to about 650 nm.

In this embodiment, the diketopyrrolopyrrole is preferably either a compound of formula (I) which shows photoluminescence the peak of which is in the range of from about 530 to about 550 nm or a compound of formula

R12 and R22 are independently of each other a C1-24-alkyl group, a C2-24-alkenyl group, a group of formula -CR30R31-(CH2)m-Ar7 or Y-R32, wherein R30 and R31 independently of each other stand for hydrogen, or C1-C4alkyl, or phenyl which can be substituted up to three times with C1-C4alkyl, Ar7 stands for aryl, C5-C8cycloalkyl, C5-C8cycloalkenyl or heteroaryl, which can be substituted one to three times with C1-C8alkyl, C1-C8alkoxy, cyano, halogen or phenyl, which can be substituted with C1-C8alkyl or Ci-Cgaikoxy one to three times, m stands for 0,1, 2,3 or 4, Y is -C(O)-, -C(O)O-, -C(O)NH-, -SO2NH- or -SO2- and R32 is C1-C18alkyl, Ar7, or aralkyl, or a group of the formula-X2-X3, Ar3 and Ar4 are independently of each other a group of formula

R41, R42, R44, R45, R46, R47 and R48 are independently of each other a hydrogen atom, a Cl- C, 8-alkyl group, a C -C s-alkoxy group, or a group -X1-X2-X3, R43 is a cyano group, a bromine atom, or a phenoxy group which can be substituted one to three times with C1-C8alkyl, or C1-C8alkoxy, or e is a hydrogen atom, or a C1-C8alkyl group, if Ar3 is not identical to Ar4, and 49 is is hydrogen, or a phenyl group which can be substituted one to three times with C1- C8alkyl, or C1-C8alkoxy, wherein S1 is-0-,-S-,-NH-,-COUH-,-COO-,-SO2-NH-, or-SO2-O-, X is an alkylene, arylene, aralkylene or cycloalkylene spacer containing optionally one or more groups -O-, -S-, -NR14-, -CO-, -CONH-, -CONR15-, or -COO- as linking bridges, X3 is OH, NH2,-C (R11) =CH2, -OC (O)-C (R12)=CH2, -C(O)-C(R12) =CH2, C5-C7cycloalkenyl,

-OC (O)-N-X4-N-C(O)-O-X5-O-C(O)-C(R12)=CH2 ; wherein R"is hydrogen, C1-C4alkyl, or halogen,

R12 is hydrogen, C1-C4alkyl, or halogen, R13 is hydrogen, C1-C4alkyl, or C6-C12 aryl, R14 and R'6 are independently of each other hydrogen, C,-C8alkyl, or C6-C12aryl, and X4 and X5 are independently of each other an alkylen, arylen, aralkylene or cycloalkylene spacer.

Ar3 and Ar4 are preferably the same and selected from the following groups:

R86 is a C18-alkyl group and R87 is a bromine atom, or R86 is a cyano group and R87 is a hydrogen atom, R88 is a C1-8-alkoxy group, R89 is a hydrogen atom, or a phenyl group, and R90 a hydrogen atom, or a C1-8-alkyl group.

The following compounds are especially preferred: Cpd. Ar3 = Ar4 R21 = R22 Abs. (nm) Fluores. (nm) B-1 3-cyanophenyl 3, 5-di-t-butylbenzyl 478 540 B-2 2-naphthyl 1-phenylethyl 479 544 B-3 4-biphenyl 1-phenylpropyl 479 544 B-4 phenyl, 4-biphenyl 3, 5-di-t-butylbenzyl 479 544 B-5 4-bromo-3-methylphenyl ethyl 480 546 B-6 4-biphenyl diphenylmethyl 484 546 B-7 4-biphenyl 1-phenylethyl 481 547 B-8 phenyl, 4-biphenyl 3,5-dimethylbenzyl 482 547 4- (4-phenyl)-3- B-9 methylphenyl 3, 5-dimethylbenzyl 485 547 B-10 4-biphenyl 2, 2-dimethylpropyl 478 549 B-11 2-naphthyl 3-phenylbenzyl 487 552 B-12 4-biphenyl 3, 5-di-t-butylbenzyl 490 552 4-biphenyl 3-methyl-2-butenyl 494 B-14 2-naphthyl 3, 5-di-t-butylbenzyl 487 553 B-15 2-naphthyl 3-methoxybenzyl 491 553 B-16 2-naphthyl 4-phenylbenzyl 487 554 B-17 2-naphthyl benzyl 489 554 B-18 2-naphthyl 4-methylbenzyl 490 554 B-19 4-biphenyl 4-cyanobenzyl 486 555 B-20 4-biphenyl 3-phenylbenzyl 490 555 B-21 4-biphenyl 3-chlorobenzyl 491 555 B-22 2-naphthyl 2-methylbenzyl 494 555 B-23 2-naphthyl 3, 5-dimethylbenzyl 490 556 B-24 4-biphenyl 3-methoxybenzyl 491 556 B-25 9-phenanthrenyl benzyl 454 557 B-26 4-biphenyl 4-methylbenzyl 489 557 B-27 4-biphenyl 4-phenylbenzyl 491 557 B-28 4-biphenyl 3,5-dimethylbenzyl 493 557 B-29 4-biphenyl 2-naphthylmethyl 495 557 B-30 6-methoxynaphth-2-yl 3, 5-di-t-butylbenzyl 496 558 B-31 6-methoxynaphth-2-yl 3-methylbenzyl 498 558 B-32 2-naphthyl 2-phenylethyl 488 559 B-33 4-biphenyl 3-pheny-2-propenyl 492 559 B-34 6-methoxynaphth-2-yl 3-phenylbenzyl 496 559 B-35 9-phenanthryl n-butyl 447 561 B-36 4-biphenyl 2-phenylethyl 489 561 B-37 9-phenanthryl allyl 445 562 B-38 4-biphenyl n-butyl ! 492 562 4-phenoxyphenyl 3, 5-dimethylbenzyl B-40 4-biphenyl n-hexyl 490 555 B-41 4-biphenyl -(CH2)6-OH 491 556 B-42 4-biphenyl -(CH2)6OC(O)C(CH3)=CH2 491 557 B-43 4-biphenyl n-C12H25 489 555 Cpd. Ar'= Ar2 R'=R 2 Abs. Fluores. A-52 1-naphthyl n-C18H37 483 551 A-53 3-(4-methylphenyl)phenyl ethyl 478 537 The light-emitting compounds 11 usually exhibit a fluorescence quantum yield ("FQY") in the range of from 1 > FQY ! 0.3 (measured in toluene). Further, in general, the compounds 11 exhibit a molar absorption coefficient in the range of from 5000 to 100000. The molar absorption coefficient and quantum yield of exemplary compounds of formula 11 are shown below : Cpd. Abs. [#] Fluores. B-1 16409 0.57 B-2 17056 0. 55 B-3 26424 0.60 B-6 9305 0. 47 B-7 26317 0.58 B-10 27805 0.60 B-11 10131 073 B-12 17768 0.67 B-13 22798 0.64 B-14 23128 0.56 B-15 25873 0.52 B-16 26489 0.57 B-17 25299 0.46 B-18 21327 0.52 B-19 18942 0. 54 Cpd. Abs.. s Fluores. B-21 26640 0.52 B-22 24063 0.64 B-23 23835 0.46 B-24 25686 0.49 B-26 25663 0.55 B-27 24730 0.66 B-28 27140 0.57 B-29 26091 0.56 B-30 33058 0.54 B-31 33437 0.53 B-32 23471 0.49 B-33 21616 0.72 B-34 31702 0.52 B-36 24090 0.49 B-38 25639 0. 49

The diketopyrrolopyrrole compound of formula 11 or alternatively formula I is used in this case with a fluorescent compound the absorption peak of which is in the range of from about 530 to about 570 nm and which shows photoluminescence the peak of which is in the range of from about 580 to about 650 nm, i. e. a red fluorescent compound. Examples of such compounds are: diketopyrrolopyrrole compounds of formula III described below, cyanine dyes, such as DCM and DCJTB, Rhodamine dyes, such as Rhodamine B and Rhodamine 6G, pyridinium salt dyes, and oxazine dyes. <BR> <BR> <P>In a further embodiment, the diketopyrrolopyrrole compound is a compound the absorption peak of which is in the range of from about 530 to about 570 nm, especially in the range of from about 540 to about 560 nm, and which shows photoluminescence the peak of which is in the range of from about 580 to about 650 nm, especially in the range of from 590 to 630 nm, and is used in combination with a fluorescent compound the absorption peak of which is in the range of from about 440 to about 500 nm and which shows photoluminescence the peak of which is in the range of from about 530 to about 570 nm.

In this embodiment, the diketopyrrolopyrrole is preferably a compound of formula

R23 and e are independently of each other a C1-24-alkyl group, a C224-alkenyl group, a group of formula -CR30R31-(CH2)m-Ar7 or Y-R32, wherein R30 and R31 independently of each other stand for hydrogen, or C1-C4alkyl, or phenyl which can be substituted up to three times with C1-C4alkyl, Ar7 stands for aryl, C5-C8cycloalkyl, C5-C8cycloalkenyl or heteroaryl, which can be substituted one to three times with d-Csatkyt, Cl-Csalkoxy, cyano, halogen or phenyl, which can be substituted with C1-C8alkyl or C1-C8alkoxy one to three times, m stands for 0,1, 2,3 or 4, Y is -C (O)-,-C (O) O-,-C (O) NH-,-SO2NH-or-SO2-and e is C1-C18alkyl, Ar7, or aralkyl, or a group-X2-X3, wherein X2 is an alkylen, arylen, aralkylene or cycloalkylene spacer containing optionally one or more groups -O-, -S-, -NR14-, -CO-, -CONH-, -CONR15-, or-COO-as linking bridge, X3 is OH, NH2, -C (R11) =CH2,-OC (O)-C (R12)=CH2, -C(O)-C(R12)=CH2, C5-C7cycloalkenyl, -OC(O)-N-X4-N-C(O)-O-X5-O-C(O)-C(R12)=CH2 ; wherein R11 is hydrogen, or C,-C4alkyl, or halogen, R12 is hydrogen, C1-C4alkyl, or halogen, R13 is hydrogen, C1-C4alkyl, or C6-C12aryl, R14 and 15 are independently of each other hydrogen, C1-C8alkyl, or C6-C12aryl, ) and X5 are independently of each other an alkylene, arylene, aralkylene or cycloalkylene spacer, Ar5 and Ar6 are independently of each other a group of formula wherein R18 and R19 are independently of each other a C1-C24alkyl group, or a group of formula wherein R29, R30 and R31 are independently of each other hydrogen, C1-C8alkyl, C1-C8alkoxy or a group-NR32R33, wherein R32 and R33 are independently of each other wherein R34 is hydrogen, C1-C8alkyl or C1-C8alkoxy,

R41 is a hydrogen atom, a CI-C, 8-alkyl group, a C1-C18-alkoxy group, or a group -X1-X2-X3, wherein X1 is -O-, -S-, -NH-, -CONH-, -COO-, -SO2-NH-, or -SO2-O-, X2 is an alkylene, arylene, aralkylene or cycloalkylene spacer containing optionally one or more groups-O-,-S-,-NR'4-,-CO-,-CONH-,-CONR'S-, or-COO-as linking bridge, X3 is OH, NH2,-C (R") =CH2,-OC (O)-C (R12)=CH2, -C(O)-C(R12)=CH2, C5-C7cycloalkenyl, -OC (O)-N-X4-N-C(O)-O-X5-O-C(O)-C(R12)=CH2 ; wherein R11 is hydrogen, C1-C4alkyl, or halogen, R12 is hydrogen, C1-C4alkyl, or halogen, R'3 is hydrogen, C1-C4alkyl, or C6-C12aryl, R14 and R15 are independently of each other hydrogen, C1-C8alkyl, or C6-C12aryl, and 6i4 and X6 are independently of each other an alkylene, arylene, aralkylene or cycloalkylene spacer, or R18 and R19 together form a five or six membered ring, in particular compounds of formula III, wherein Ar@ and Ar@ are independently of each other a group of formula Abs. Flores. Cpd. R18 R19 R23 = R24 (nm) (nm) C-1 CH3 CH3 3-bromobenzyl 541 582 C-2 phenyl phenyl methyl 544 590 C-3 phenyl 3, 5-di-t-butylbenzyl methyl 533 591 C-4 phenyl 1-naphthyl methyl 536 591 C-5 phenyl phenyl allyl 540 591 C-6 phenyl phenyl benzyl 541 594 C-7 phenyl phenyl 3-methylbenzyl 542 594 C-8 phenyl phenyl 3, 5-dimethylbenzyl 543 594 C-9 4-methylphenyl 4-methylphenyl n-butyl 533 596 C-10 4-methylphenyl 4-methylphenyl 3, 5-di-t-butylbenzyl 536 596 C-11 Phenyl phenyl 4-fluorobenzyl 542 597 C-12 phenyl phenyl 3-bromobenzyl 543 597 C-13 phenyl phenyl 4-bromobenzyl 544 597 C-14 2-naphthyl 2-naphthyl n-butyl 537 599 C-15 phenyl phenyl 3, 5-dibromobenzyl 542 599 C-16 phenyl 2-naphthyl benzyl 544 599 C-17 phenyl phenyl 2-bromobenzyl 553 600 C-18 phenyl phenyl 3-cyanobenzyl 544 601 C-1 9 phenyl phenyl 4-cyanobenzyl 549 601 C-20 4-methylphenyl 4-methylphenyl benzyl 551 602 C-21 2-naphthyl 2-naphthyl benzyl 547 603 C-22 4-methoxyphenyl 4-methoxyphenyl n-butyl 540 605 C-23 4-biphenyl phenyl methyl 547 606 C-24 phenyl phenyl 3,4-dicyanobenzyl 556 606 C-25 4-methylphenyl 4-methylphenyl 4-cyanobenzyl 557 612 C-26 4-methoxyphenyl 4-methoxyphenyl benzyl 550 613 C-27 4-methoxyphenyl 4-methoxyphenyl n-hexyl 542 606 C-28 4-methoxyphenyl 4-methoxyphenyl -(CH2)6-OH 543 608 C-29 4-methoxyphenyl 4-methoxyphenyl- (CH2) 60C (O) C (CH3) =CH2 543 608 C-30 phenyl phenyl n-hexyl 546 595 C-31 phenyl phenyl-(H2) 6-OH 546 598 C-32 phenyl phenyl- (CH2) 60C (O) C (CH3) =CH2 546 598 C-33 phenyl phenyl n-hexyl 536 598 C-34 4-methylphenyl 4-methylphenyl- (CH2) 6-OH 548 604 C-35 4-methylphenyl 4-methylphenyl- (CH2) 60C (O) C (CH3) =CH2 542 602 C-36 4-methylphenyl 4-methylphenyl n-C12H25 543 598 are especially preferred and the following compounds are most preferred: The light-emitting compounds III usually exhibit a fluorescence quantum yield ("FQY') in the

range of from 1 > FQY ! 0.3 (measured in toluene). Further, in general, the compounds III exhibit a molar absorption coefficient in the range of from 5000 to 100000. The molar absorption coefficient and quantum yield of exemplary compounds of formula III are shown below : Cpd. Abs. [E] Fluores. [(p] C-1 43337 0. 43 C-2 43753 0.45 C-3 47384 0. 48 C-5 45875 0. 43 C-6 47549 0. 47 C-7 53747 0.42 C-8 48576 0.45 C-12 53074 0.49 C-13 51870 0. 44 C-15 36856 0. 47 Cpd. Abs. E Fluores. C-16 49779 0. 71 C-17 46863 0. 40 C-19 45701 0.67 C-20 40286 0.57 C-22 44948 0. 40 C-23 48401 0.44 C-24 19239 0. 59 C-25 33069 0. 46 C-26 48110 0.55

The diketopyrrolopyrrole compound of formula III is used in this case with a fluorescent compound the absorption peak of which is in the range of from about 440 to about 500 nm and which shows photoluminescence the peak of which is in the range of from about 530 to about 570 nm, i. e. a yellow-green fluorescent compound. Edzamples of such compounds are : diketopyrrolopyrrole compounds of formula I or 11 described above, Coumarin dyes, such as Coumarin 5, Coumarin 7, Coumarin 30, Coumarin 153, and naphthalimide dyes, such as solvent yellow 11 and solvent yellow 116.

If a diketopyrrolopyrrole compound of formula III is used with a diketopyrrolopyrrole compound of formula I or II the following combinations are especially preferred: Compound of Formula I Compound of Formula III N-% _on N O/\ \/O 0 0 . O P N N-% _ON N N----- -N O/\ \/O I a N. N I cr/o 'X}

The term"halogen"is generally iodine, fluorine, bromine or chlorine, preferably bromine or chlorine.

In a further embodiment the diketopyrrolopyrrole compound is a compound the absorption of which is in the range of from about 500 to about 530 nm, especially in the range of from about 500 to about 520 nm, and which shows photoiuminescence the peak of which is in the range of from 540 to 600 nm, especially in the range of from 550 from 580 nm, and is used in combination with a fluorescent compound the absorption peak of which is in the range of from about 530 to about 570 nm and which shows photoluminescence the peak of which is in the range of from about 580 to about 650 nm, and optionally with a fluorescent compound the absorption peak of which is in the range of from about 440 to about 500 nm and which shows photoluminescence the peak of which is in the range of from about 530 to about 570 nm.

In this embodiment the diketopyrrolopyrrole is preferably a compound of formula

R9'and R92 are independently of each other a C1-C24alkyl group, a C2-C24alkenyl group, a group of formula -CR30R31-(CH2)m-Ar7 or Y-R32, wherein R30 and R3'independently of each other stand for hydrogen, or C1-C4alkyl, or phenyl which can be substituted up to three times with C,-C4alkyl, Ar7 stands for C6-C24aryl, C5-C8cycloalkyl, C5-C8cycloalkenyl, or heteroaryl, which can be substituted one to three times with C,-C8alkyl, C1-C8alkoxy, cyano, halogen or phenyl, which can be substituted with C1-C8alkyl or d-Csatkoxy one to three times, m stands for 0,1, 2, 3 or 4, Y is-C (O)-,-C (O) O-,-C (O) NH-, -SO2NH- or -SO2-, R32 is C1-C18alkyl, Ar7, or C7-C24aralkyl, or a group of the formula -X2-X3, Ar8 and Ar9 are independently of each other a group of formula

R46 is a C1-C18alkoxy group, R44, R45, R55, R65 and R66 are independently of each other a hydrogen atom, a C1-C18alkyl group, a C1-C18-alkoxy group, or a group -X1-X2-X3, wherein X1 is -O-, -S-, -NH-, -CONH-, -COO-, -SO2-NH-, or -SO2-O-.

X2 is an alkylene, arylene, aralleylene or cycloalkylene spacer containing optionally one or more groups -O-, -S-, -NR14-, -CO-, -CONH-, -CONR15-, or-COO-as linking bridge, X3 is-OH,-NH2,-C (R") =CH2,-OC (O)-C (R 12) =CH2, -C (O)-C (R12)=CH2, C5-C7cycloalkenyl,

- OC(O)-N-X4-N-C(O)-O-X5-O-C(O)-C(R12)=CH2 ; wherein

R11 is hydrogen, C1-C4alkyl, or halogen, R12 is hydrogen, C1-C4alkyl, or halogen, R'3 is hydrogen, C1-C4alkyl, or C6-C12aryl, R14 and R15 are independently of each other hydrogen, C1-C8alkyl, or C6-C12aryl, and X4 and X5 are independently of each other an alkylene, arylene, aralkylene or cycloalkylene spacer.

R93 and R94 are independently of each other a C1-C18alkyl group, Y1 is -O-, -S-, -SO2-, -NR68-, -CHR68-, and ni is1, 2, or 3, especially 1, or 2, wherein R68 is C1- C18-alkyl, or C6-C12aryl.

The following diketopyrrolopyrroles of formula IV are especially preferred:

The light-emitting compounds IV usually exhibit a fluorescence quantum yield ("FQY") in the range of from 1 > FQY : 0. 3 (measured in toluene). Further, in general, the compounds of formula IV exhibit a molar absorption coefficient in the range of from 5000 to 100000. The molar absorption coefficient and quantum yield of exemplary compounds of formula IV are shown below : Abs. Flores. Abs. Flores. Cpd. (nm) (nm) D-1 510 559 39043 0. 51 D-2 513 564 42085 0. 53 D-3 507 569 38540 0. 46 D-4 520 568 43342 0. 43 D-5 510 575 30669 0. 38 D-6 510 578 31283 0. 37 D-7 506 572 30669 0. 41 D-8 511 563 38078 0.48 The diketopyrrolopyrrole compound of formula IV is used in this case with a fluorescent compound the absorption peak of which is in the range of from about 530 to about 570 nm and which shows photoluminescence the peak of which is in the range of from about 580 to about 650 nm, i. e. a red fluorescent compound. Examples of such compounds are: diketopyrrolopyrrole compounds of formula III described above, cyanine dyes, such as DCM and DCJTB, Rhodamine dyes, such as Rhodamine B and Rhodamine 6G, pyridinium salt dyes, and oxazine dyes.

In this case a fluorescent compound can optionally be present, the absorption peak of which is in the range of from about 440 to about 500 nm and which shows photoluminescence the peak of which is in the range of from about 530 to about 570 nm, i. e. a yellow-green fluorescent compound. Examples of such compounds are: diketopyrrolopyrrole compounds of formula I or 11 described above, Coumarin dyes, such as Coumarin 5, Coumarin 7, Coumarin 30, Coumarin 153, and naphthalimide dyes, such as solvent yellow 11 and solvent yellow 116.

C-C4aIkyl group is methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl ; C1-C8alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert- butyl, n-amyl, tert-amyl or hexyl ;

C1-C18alkyl is, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert- butyl, n-amyl, tert-amyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl.

The term"alkylene"means in general linear or branched C1-C18alkylene, wherein examples of preferred linear representatives are for example- (CH2) 4-,- (CH2) 5-,- (CH2) 6-,- (CH2) 7-,- (CH2)8-, -(CH2)9-, -(CH2)10-, -(CH2)11-, -(CH2)12-, -(CH2)13-, -(CH2)14-, -(CH2)15-, -(CH2)16-, - (CH2) 7-, -(CH2)18-, preferably C4-C16alkylene such as- (CH2) 4-,- (CH2) 5-,- (CH2) 6-,- (CH2) 7-,- (CH2)8-, -(CH2)9-, -(CH2)10-, -(CH2)11-, or -(CH2)12-.

The"alkoxy group"in C1-C18alkoxy can be linear or branched and is for example methoxy, ethoxy, n-propoxy, isopropoxy, butyloxy, hexyloxy, decyloxy, dodecyloxy, hexadecyloxy or octadecyloxy, preferably Ci-Cga) koxy such as methoxy, ethoxy, n-propoxy, isopropoxy, butyloxy, hexyloxy, or octyloxy.

C1-C18alkylmercapto is, for example, methylmercapto, ethylmercapto, propylmercapto, butylmercapto, octylmercapto, decylmercapto, hexadecylmercapto or octadecylmercapto.

C1-C18alkylamino is, for example, methylamino, ethylamino, propylamino, hexylamino, decylamino, hexadecylamino or octadecylamino, preferably C1-C6alkylamino such as methylamino, ethylamino, propylamino or hexylamino.

The term"aryl group"is typically C6-C24aryl, such as phenyl, indenyl, azulenyl, naphthyl, biphenyl, as-indacenyl, s-indacenyl, acenaphthylenyl, phenanthryl, fluoranthenyl, triohenlenyl, chrysenyl, naphthacen, picenyl, perylenyl, pentaphenyl, hexacenyl, pyrenyl, or anthracenyl, preferably phenyl, 1-naphthyl, 2-naphthyl, 9-phenanthryl, 2- or 9-fluorenyl, 3-or 4-biphenyl, which may be unsubstituted or substituted. Examples of C6-C12aryl are phenyl, 1-naphthyl, 2-naphthyl, 3-or 4-biphrnyl, which may be unsubstituted or substituted.

The term"aralkyl group"is typically C7-C24aralkyl, such as benzyl, 2-benzyl-2-propyl, P-phenyl-ethyl, a, α-dimethylbenzyl, #-phenyl-butyl, #,#-dimethyl-#-phenyl-butyl, bphenyl-dodecyl, #-phenyl-octadecyl, #-phenyl-eicosyl or ophenyl-docosyl, preferably C7-C1saralkyl such as benzyl, 2-benzyl-2-propyl, (3-phenyl-ethyl, a, a-dimethylbenzyl, <BR> <BR> <BR> #-phenyl-butyl, #,#-dimethyl-#-phenyl-butyl, #-phenyl-dodecyl or #-phenyl-octadecyl, and particularly preferred C7-C12aralkyl such as benzyl, 2-benzyl-2-propyl, ß-phenyl-ethyl, a, a-dimethylbenzyl, phenyl-butyl, or c3, #-dimethyl-#-phenyl-butyl, in which both the

aliphatic hydrocarbon group and aromatic hydrocarbon group may be unsubstituted or substituted.

The term"cycloalkyl group"is typically C5-Cl2CYCloalkyl, such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, preferably cyclopentyl, cyclohexyl, cycloheptyl, or cyclooctyl, which may be unsubstituted or substituted.

The term"cycloalkenyl group"means an unsaturated alicyclic hydrocarbon group containing one or more double bonds, such as cyclopentenyl, cyclopentadienyl, cyclohexenyl and the like, which may be unsubstituted or substituted. The cycloalkyl group, in particular a cyclohexyl group, can be condensed one or two times by phenyl which can be substituted one to three times with C1-C4-alkyl, halogen and cyano. Examples of such condensed cyclohexyl groups are : R51 I R51 RS2>/\l R52 R-t i J '-1 T) s39 539 // in particular R or R, wherein F. 51 52 e si z55 and R56 are independently of each other C1-C8-alkyl, C1-C8-alkoxy, halogen and cyano, in particular hydrogen.

The term dIheteroaryl group"is a ring, wherein nitrogen, oxygen or sulfur are the possible hetero atoms, and is typically an unsaturated heterocyclic radical with five to 18 atoms having at least six conjugated-electrons such as thienyl, benzo [b] thienyl, dibenzo [b, d]thienyl, thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl, isobenzofuranyl, 2H-chromenyl, xanthenyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl, 1 H-pyrrolizinyl, isoindolyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, 3H-indolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl, 4aH-carbazolyl,

carbolinyl, benzotriazolyl, benzoxazolyi, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl or phenoxazinyl, preferably the above-mentioned mono-or bicyclic heterocyclic radicals, which may be unsubstituted or substituted.

The term"alkylene (spacer) "is typically C1-C30alkylene, preferably C1-C16alkylene, and embraces the linear as well as the branched representatives and can be, for example,-CH2- and C2-C30alkylene, such as- (CH2) 2-,-CH (Me)-,- (CH2) 3-,-CH2-CH (Me) -, -C (Me) 2-,- (CH2) 4-,- (CH2) 5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, -(CH2)9-, - (CH2) 10-, -(CH2)11-, -(CH2)12-, -(CH2)13-, -(CH2)14- , -(CH2)15-, -(CH2)16-, -(CH2)17-, -(CH2)18-, -(CH2)19-, -(CH2)20, -(CH2)21-, -(CH2)22-, -(CH2)23-, - (CH2) 24-, -(CH2)25-, -(CH2)26-, -(CH2)27-, -(CH2)28-, -(CH2)29-, -(CH2)30-, preferably -CH2-, - (CHz) 2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, -(CH2)7-, -(CH2)8-, -(CH2)9-, -(CH2)10-, -(CH2)11-, - (CH2) 12-, -(CH2)13-, -(CH2)14-, -(CH2)15-, -(CH2)16-, -(CH2)17-, -(CH2)18-, and also -CH(C2- C30alkylene)-. The"alkylene spacer"can optionally comprise one or more, in particular one or two groups selected from -O-, -S-, -NR114-, -CO-, -CONH-, -CON115-, or-COO-as linking group. C-C30alkylene can, for example, be interrupted several times by-O-,-S-,-NH-or- C (O) NH-, such as- (CH2) 2-0- (CH2)-,- (CH2) 2-0- (CH2) 2-,- (CH2) 2-S- (CH2) 2-,-CH2-CH-CH2-0- (CH2) p-CH3, wherein p is an integer from 1 to 10 ; or -CHX13CH2-(X14)n-OH, wherein X13 is C1- C8alkyl, X14 is an alkylene oxide monomer, preferably ethylene oxide or propylene oxide, or alkylen amino monomer, preferably amino ethylene or amino propylene, and n is an integer from 1 to 10, preferably 1 to 5; or-(CH2) 2-NH-(CH2) 2-or-(CH2) 2-C (O) NH-(CH2) 2-, wherein R'14 and R"5 are independently of each other hydrogen, C-Csalkyl, or C6-C12aryl.

"Arylene (spacer)"is an unsubstituted or substituted carbocylic or heterocyclic arylene group, preferably containing 6 to 14 carbon atoms, typically phenylene, naphthylene, anthracenylene, anthraquinonylene, pyridinylene, quinolinylene, preferably a group wherein X"is a single bond in ortho-, meta-or para-position, or -O-, -S-, -NR114-, -CO-, -CONH-, -CON115-, or-COO-in ortho-, meta-or para-position; para-phenylene and para-phenylenoxy are preferred.

"Aralkylene (spacer) "is an unsubstituted or substituted carbocylic or heterocyclic aralkylene group, preferably containing 6 to 14 carbon atoms, preferably a group wherein X"is a single bond in ortho-, meta-or para-position, or -O-, -S-, -NR114-, -CO-, -CONH-, -CON115-, or-COO-in ortho-, meta-or para-position, and

X12 is alkylen, or a group (\), wherein X12 is alkylen in ortho-, meta-or X12 X11 para-position and X"is a single bond, -O-, -S-, -NR114-, -CO-, -CONH-, -CON115-, or-COO-.

"Cycloalkylene (spacer) "is an unsubstituted or substituted carbocylic or heterocyclic cycloalkylene group, preferably containing 6 to 14 carbon atoms, typically cyclohexylene, preferably a group wherein X"is a single bond in 2-, 3-or 4-position, or -O-, -S-, -NR114-, -CO-, -CONH-, -CON115-, or -COO- in 2-, 3- or 4-position ; 4-cyclohexylene and 4-cyclohexylenoxy are preferred.

The above-mentioned groups can be substituted by a Ci-C8alkyl, a hydroxyl group, a mercapto group, C1-C8alkoxy, C1-C8alkylthio, halogen, halo-C1-C8alkyl, a cyano group, an aldehyde group, a ketone group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group group a siloxanyl group.

The term "carbamoyl group" is typically a C1-18carbamoyl radical, preferably C1-8carbamoyl radical, which may be unsubstituted or substituted, such as, for example, carbamoyl, methylcarbamoyl, sthylcarbamoyl, n-butylcarbamoyl, tert-butylcarbamoyl, dimethylcarbamoyloxy, morpholinocarbamoyl or pyrrolidinocarbamoyl.

The term"silyl group"means a group of formula -SiR72R73R74, wherein RI, R73 and R74 are independently of each other a Ci-Cga) ky) group, in particular a Cl-C4 alkyl group, a C6-C24aryl group or a C7-C12aralkylgroup, such as a trimethylsilyl group. The term"siloxanyl group" means a group of formula -O-SiR72R73R74, wherein R72, R73 and R74 are as defined above, such as a trimethylsiloxanyl group.

The terms"haloalkyl, haloalkenyl and haloalkynyl"mean groups given by partially or wholly substituting the above-mentioned alkyl group, alkenyl group and alkynyl group with halogen, such as trifluoromethyl etc. The"aldehyde group, ketone group, ester group, carbamoyl group and amino group"include those substituted by an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or a heterocyclic group, wherein the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group and the heterocyclic group may be unsubstituted or substituted.

The light emitter for use in the invention is not specifically defined, including, for example, EL (electroluminescent) devices, LEDs (light emitting diodes), VFDs (visual fluorescence displays), PDP (plasma display panels) etc.

The light emitter is preferably an organic or inorganic electroluminescent element, which comprises an organic or inorganic electroluminescent material part which emits blue light.

An example of an inorganic electroluminescent material part which emits blue light, comprises a substrate, a metal, a thick film dielectric which consists of a lead magnesium niobate (PMN) combined with a lead zirconate titanate (PZT) based material, a blue phosphor, such as, for example, SrS: Ce, BaA12S4 : Eu (Leo = 200 cd/m2 with CIE x, y coordinates 0.135 and 0. 105, respectively) or MgxBai-xA) 2S4 : Eu (x = 0 to 1.0), and an indium tin electrode (MgxBai. xAi2S4 : Eu Blue Phosphor on Fire Thick Dielectric Substrates-Dan Cheong et al., December 2002; Self-Aligned Phosphor Patterning Techniques for IEL Displays-D. Seale et al., May 2002; W00070917, W002100978, W002098180, especially WO0223957, which discloses a blue phosphor comprising a composition of the formula M'8Ba1 a M"2 M'''4 : RE, where M'is at least one element selected from the group consisting of magnesium and calcium, M"is at least one element selected from the group consisting of aluminum, gallium and indium, M"'is at least one element selected from the group consisting of sulphur, selenium and tellurium, RE is at least one rare earth element, and 0 < a < 1. ). In case of an inorganic electroluminescent material part comprising in addition to the blue phosphor a green phosphor, for example (Zn, Mg) S: Mn, the diketopyrrolopyrrole compounds of formula III can be applied as green-to-red CCM.

Next the present invention is illustrated in more detail on the basis of an organic electroluminescent material part.

"Bottom electrode,"as used herein, means an electrode that is deposited directly onto the substrate.

"Top electrode,"as used herein, means an electrode that is deposited at the end of the OLED that is distal to the substrate.

"Hole-injection layeras used herein, is a layer into which holes are injected from an anode when a voltage is applied across an OLED.

"Hole-transport layeras used herein, is a layer having high hole mobility and high affinity for holes that is between the anode and the emitter layer. It will be evident to those of skill in the art that the hole-injection layer and the hole-transport layer can be a single layer ("hole-injection/hole-transport layer"), or they can be distinct layers comprising different chemical compounds.

"Electron-injection layeras used herein, is a layer into which electrons are injected from a cathode when a voltage is applied across an OLED.

"Electron-transport layeras used herein, is a layer having high electron mobility and high affinity for electrons that is between the cathode and the emitter layer. It will be evident to those of skill in the art that the electron-injection layer and the electron-transport layer can be a single layer ("electron-injectionlelectron-transpork layer"), or they can be distinct layers comprising different chemical compounds.

"Down-emitting,"as used herein, refers to an OLED in which light is transmitted through the transparent or semi-transparent bottom electrode, which is typically an anode.

"Up-emitting, "as used herein, refers to an OLED in which light is transmitted through the transparent or semi-transparent top electrode, which is typically a cathode.

High energy (i. e., blue) light in full-color OLED display devices may be produced by any source, but is preferably produced by an emissive monochromatic OLED display device, such as the one described below. The monochromatic OLED display device may or may not be pixilated. Preferably the OLED display is pixelated and is of high resolution, for example, with sub-pia ; l sizes less than about 50 . rrr, preferably less than about 25 . m, more preferably less than about 10 µm.

The device comprises a substrate, which can be transparent or opaque (and which may further comprise driving electronics), a patterned bottom electrode, which is a cathode or an anode, a first charge transport layer, which is a hole-transport layer if the bottom electrode is an anode and which is an electron-transport layer if the bottom electrode is a cathode, an emitter layer, a second transport layer, which is a hole-transport layer if the bottom electrode is a cathode and which is an electron-transport layer if the bottom electrode is an anode, a top electrode, which is a cathode if the bottom electrode is an anode and which is an anode if the bottom electrode is a cathode, and which may be patterned (i. e. , in passive matrix

displays) and a protective layer. Each element of the patterned bottom electrode represents one pixel in the matrix. When current is applied to the elements of the patterned bottom electrode, holes are transported through the hole-transport layer and electrons are transported through the electrontransport layer and holes and electrons recombine in the light emitting layer to produce light of the same wavelength, e. g., blue light, at each pixel.

"Patterning,"as used herein, means that the materials are formed into stripes, squares, rectangles, triangles, hexagons, circles, or any other shape known in the art.

Preferably, each individual OLED is rectangular and the color changing materials are patterned in parallel stripes, or rectangular dots. The patterning of color changing materials provides for the formation of discrete red, green and blue sub-pixels, without having the colors mix together.

Electrodes can be patterned by any method known in the art, including, but not limited to lithographic, particularly photolithographic techniques, laser ablation, and masking during deposition.

Each element of the patterned electrode represents one sub-pixel in the matrix. A first patterned color changing material (A) is aligned with a first element of the patterned bottom electrode, so that the first patterned color changing material (A) is directly above a specified element. In a similar fashion, the second patterned color changing material (B) is aligned with a second element of the patterned bottom electrode adjacent to the first element. A third element of the patterned bottom electrode adjacent to the second element is not aligned with a patterned color changing material. When a current is applied between the top electrode and the patterned bottom electrode, holes are transported through the hole-transport layer and electrons are transported through the electron-transport layer and holes and electrons recombine in the emitter layer to produce light of a particular wavelength, e. g., blue light, at each sub-pisel. For a green sub-pizef, when blue light is emitted from the emitter layer at the first element of the patterned electrode, it is absorbed by the first patterned color changing material (A) ("blue-to-green CCM") that is aligned with the first element. The first patterned color changing material (A) then emits green light by fluorescence. For a red sub-pixel, when blue light is emitted from the emitter layer at the second element of the patterned bottom electrode, it is absorbed by the second patterned color changing material (B) ("blue-to-red CCM") that is aligned with the second element. The second patterned color changing material (B) then emits red light by fluorescence. For a blue sub-pixel, when blue light is emitted by the emitter layer at the third element of the patterned bottom electrode, the blue light is transmitted through the various layers substantially without being absorbed. The patterning of the first and second color changing materials are repeated every fourth element, resulting in an array of pixels each comprising a red, a green and a blue sub-pixel.

An embodiment of a down-emitting full-color OLED display device, comprises a first color changing layer comprising a first patterned color changing material (A) deposited on a substrate, a first protective layer covering the first color changing layer formed on a transparent or semi transparent substrate. A second color changing layer comprises a second patterned color changing material (B) adjacent to the first protective layer, a second protective layer covering the second color changing layer, a patterned bottom electrode, which is a cathode or an anode, a first charge transport layer, which is a hole-transport layer if the bottom electrode is an anode and which is an electron-transport layer if the bottom electrode is a cathode, an emitter layer, a second charge transport layer, which is a hole-transport layer if the bottom electrode is a cathode and which is an electron-transport layer if the bottom electrode is an anode, a top electrode, which is a cathode if the bottom electrode is an anode and which is an anode if the bottom electrode is a cathode, and an encapsulation layer.

In this embodiment, for a red sub-pixel, blue light is emitted downward from the emitter layer at the first element of the patterned bottom electrode, and is absorbed by the first patterned color changing material (A) ("blue-to-red CCM") that is aligned with the first element. The first patterned color changing material then emits red light by fluorescence (or phosphorescence). For a green sub-pixel, when blue light is emitted from the emitter layer at the second element of the patterned bottom electrode, it is absorbed by the second patterned color changing material (B) ("blue-to-green CCM") that is aligned with the second element. The second patterned color changing material (B) then emits green light by fluorescence or phosphorescence. For a blue sub-pixel, when blue light is emitted by the emitter layer at the third element of the patterned bottom electrode, the blue light is transmitted through the various layers substantially without being absorbed The patterning of the first and second color changing materials are repeated every fourth element, resulting in an array of pixels each comprising a red, a green and a blue sub-piobel.

OLEDs can be fabricated by any method known in the art. The OLED layers may be formed by evaporation, spin casting, self-assembly or other appropriate flmforming techniques.

Thicknesses of the layers typically range from a few monolayers to about 2,000 Angstroms.

In one embodiment, OLEDs are formed by vapor deposition of each layer. In a preferred embodiment, OLEDs are formed by thermal vacuum vapor deposition.

The OLEDs described above are by way of example, and any type can be used. For example, an OLED may comprise a hole-injection layer adjacent to the anode and at least two hole-transport layers, a first hole-transport layer adjacent to the hole-injection layer and a second hole-transport layer adjacent to the first holetransport layer. The hole-injection layer

and the at least two hole-transport layers may be deposited separately. Alternately, at least two of the layers may be inter-deposited.

An OLED may comprise an electron-injection layer and at least one electrontransport layer, or the OLED can further comprise an additional layer adjacent to the top electrode. In a preferred embodiment, the layer comprises indium tin oxide.

An OLED may comprise a light emitting layer or two light emitting layers, optionally which contain electron-injection layer and/or one electron transport layer, and/or hole-injection layer and one or two hole-transport layers.

The organic EL device usable in the invention is basically so constructed that a light emission layer is sandwiched between a pair of electrodes.

Concretely, it may have any of the following structures: (1) Anode/light emission layer/cathode, (2) Anode/hole injection layer/light emission layer/cathode, (3) Anode/light emission layer/electron injection layer/cathode, (4) Anode/hole injection layer/light emission layer/electron injection layer/cathode.

Organic EL devices emitting blue light and their fabrication are described, for example, in US-B-6,464, 898, column 1Q, line 24 to column 20, line 48. The organic EL device disclosed in Example 1 of US-B-6, 464, 898 having the following structure : ITO anode/4, 4', 4"-tris [N- (3- methylphenyl)-N-phenylamino] triphenylamine (MTDATA; hole-injecting material)/4, 4'-bis [N- (1-naphthyl)-N-phenylamino] biphenyl NPD (hole-injecting material)/4, 4'-bis (2, 2- diphenylvinyl) biphenyl (DPVBi ; light emitting layer)/tris (8-quinolinol) aluminium (Alq ; electron injection layer)/magnesium and silver cathode, is preferred. Other OLED structures will be evident to those skilled in the art.

A substrate may be made from any material known in the art, including glass, silicon, plastic, quartz and sapphire. If the OLED display is formed on a silicon chip, the chip preferably includes drive electronics and one of the sub-pixet electrodes. The top electrode may be common to all sub-pixels.

An anode is typically about 800 A thick and can have one layer comprising a metal having a high work function, a metal oxide and mixtures thereof. Preferably, the anode comprises a material selected from the group consisting of a conducting or semiconducting metal oxide or mixed metal oxide such as indium zinc tin oxide, indium zinc oxide, ruthenium dioxide, molybdenum oxide, nickel oxide or indium tin oxide, a metal having a high work function, such as gold or platinum, and a mixture of a metal oxide and a metal having a high work function. In one embodiment, the anode further comprises a thin layer (approximately thick)

of dielectric material between the anode and the first hole-injection/hole-transport layer.

Examples of such dielectric materials include, but are not limited to, lithium fluoride, cesium fluoride, silicon oxide and silicon dioxide. In another embodiment, the anode comprises a thin layer of an organic conducting material adjacent to the hole injection/hole-transport layer.

Such organic conducting materials include, but are not limited to polyaniline, PEDOT-PSS, and a conducting or semi-conducting organic salt thereof.

A semi-transparent cathode is typically between 70 and 150 A thick. In one embodiment, the cathode comprises a single layer of one or more metals, at least one of which has a low work function. Such metals include, but are not limited to, lithium, aluminum, magnesium, calcium, samarium, cesium and mixtures thereof. Preferably, the low work function metal is mixed with a binder metal, such as silver or indium. In another embodiment, the cathode further comprises a layer of dielectric material adjacent to the electron-injection/electron-transport layer, the dielectric material including, but not limited to, lithium fluoride, cesium fluoride, lithium chloride and cesium chloride. Preferably, the dielectric material is lithium fluoride or cesium fluoride. In preferred embodiments, the cathode comprises either aluminum and lithium fluoride, a mixture of magnesium and silver, a mixture of lithium and aluminum, or calcium followed by aluminum. In yet another embodiment, the cathode comprises magnesium, silver and lithium fluoride.

In one embodiment, the hole-injection/hole-transport layer is about 750 A thick.

Hole-injection/hole-transport layers typically comprise at least one material with good hole mobility. Examples of such materials include, but are not limited to, copper phthalocyanine (CuPc), and aromatic amine compounds such as N, N'-bisnaphthyl)-N, N'-diphenyl-1, 1'-biphenyl-4, 4'-diamine (NPD), bis (N, N'-1-naphthy !-pheny)-amino-bipheny))-biphenyt amine (BPA-DNPB) and bis(carbazol-N-biphenyl)-biphenyl amine (BPA-BCA).

An OLED may further comprise an emitter layer between the electron-injection/electron-transport layer and the hole-injection/hole-transport layer in which electrons from the electron-injection/electron-transport layer and holes from the hole injecting/hole-transport layer recombine. Depending on the composition of the emitter layer, OLEDs emit visible light of different colors. Emitter layers typically comprise at least one host compound, either alone or together with at least one dopant compound, which is a luminophor. Examples of host compounds include, but are not limited to, 2,2', 7, 7'-naphthyl-9, 9'-spirobifluorene (N-SBF), ALQ, IDE-120 and IDE140 (Idemitsu Kosan Co. , Ltd., Tokyo, Japan). Eamples of dopant compounds include, but are not limited to, Coumarin 6, Coumarin 485, Coumarin, 487, Coumarin 490, Coumarin 498, Coumarin 500, Coumarin 503, Coumarin 504, Coumarin 504T, Coumarin 510, Coumarin 515, Coumarin

519, Coumarin 521, Coumarin 521T, Coumarin 522B, Coumarin 523, Coumarin 525, Coumarin 535, Coumarin 540A, Coumarin 545, Coumarin 545T, quinacridone derivatives such as diethyl pentyl quinacridone and dimethyl quinacridone, distyrylamine derivatives, such as IDE-102, IDE-105 (Idemitsu Kosan Co., Ltd. , Tokyo, Japan), rubrene, DCJTB, pyrromethane 546, and mixtures thereof. The structure of DCJTB is shown below : In one embodiment, the emitter layer emits blue light and comprises IDE-102 and IDE-120.

The emitter layer may be between 200-400 A thick.

The electron-injection/electron-transport layer is typically about 350 A thick and comprises a compound such as ALQ, or a suitable oxadiazole derivative. In a preferred embodiment, the electron-injection/electron-transport layer is N-SBF, ALQ, or a mixture of N-SBF and ALQ.

In one embodiment, a blue-emitting OLED for use in color OLED displays comprises an anode comprising indium tin oxide, a hole-injection layer adjacent to the anode comprising CuPc, a hole-transport layer adjacent to the hole-injection layer comprising NPD, an emitter layer adjacent to the hole-transport layer comprising DCJTB, IDE-102 and IDE-120, an electron-transport iayer adjacent to the emitter layer comprising ALQ, and a cathode comprising lithium fluoride and aluminum.

A method for forming patterned color changing materials on or under an OLED display device will now be described. In the first step step, a blue-to-green CCM layer, for example, is deposited on the protective layer of an up-emitting monochromatic OLED display device.

In the case of a down-emitting device the layer would be deposited on the substrate. CCM layers can be deposited by any method known in the art, including spin-coating, meniscus-coating, spray-coating, dip-coating, blade-coating, from solution or suspension or by sublimation in a vacuum.

When a voltage is applied, the monochromatic OLED display emits blue light, which is either transmitted through the protective layers at a blue sub-pixel or is absorbed by the patterned

blue-to-green CCM or by the patterned blue-to-red CCM, which in turn emit green or red light, respectively, to form a green sub-pixel and a red sub-pixel, respectively. Thus, a full-color OLED display device is formed.

In addition, although the method of the present invention has been illustrated for generating red and green sub-pixels, one of skill in the art will recognize that subpixels of any color can be generated simply by altering the color changing materials. For example, only one CCM layer can be used on a monochromatic OLED display device. Alternatively, many CCM layers can be used and the CCM emission colors may vary, e. g., one could have a monochromatic OLED display that emits deep blue light in combination with CCM films patterned as described herein that emit, for example, yellow/green and orange light.

Preferably, the monochromatic OLED display device emits blue light (close to CIE (0.155 ; 0.07)) and there are two CCM layers, one emitting red light (close to CIE (0. 625 ; 0.34)) and the other emitting green light (close to CIE (0.28 ; 0.595)) to form a proper red-green-blue ("RGB") display.

If multiple CCM or filter layers are deposited on a single substrate and sequentially on top of each other, then a protective layer is deposited over each patterned layer. The protective layer preferably comprises inert materials that are transparent and have low or no luminescence. The protective layer is preferably not patterned. Without being bound by any theory, the protective layer absorbs the radiation used in the patterning method and/or prevents ambient oxygen from penetrating to the lower layers in order to prevent the already-patterned underlying layers from being re-exposed.

Suitable materials for the protective layer are preferably able to absorb light used in the methods of the present invention (usually ultraviolet light), are able to block oxygen penetration into the other layers, are transparent to visible light (usually red, green and blue), are non-fluorescent and are easily deposited onto the CCM layers without harming them.

Preferably, such materials are deposited onto the CCM layers by heat or e-beam evaporation or are sputtered (reactive DC or RF). Suitable protective layer materials are known in the art and include, but are not limited ed to, metal oxides such as SiO2, SiN, MgO, and ITO, organic polymers, conjugated polymers, additives such as benzophenones, heat and/or ultraviolet curing epoxy compounds, spin-on-glass materials, siloxane and combinations thereof.

Color changing materials may comprise any material known in the art. For example, CCM layers may comprise compounds including, but not limited to, pure sublimed fluorescent compounds, sublimed host molecules that are doped (co-evaporated) with other materials in order to improve quantum efficiency of photoluminescence, purely organic or organometallic materials, or unconjugated, conjugated or partially conjugated polymers or co-polymers.

If a CCM is a doped layer, the host can be chosen to optimize its absorption of the wavelength of light emitted by the monochromatic OLED display (usually blue light), and the dopant can be chosen to emit the desired wavelength of light (usually red or green light).

Instead of the DPP compounds of formula I known blue-to-green CCM and instead of the DPP compounds of formula I or 11 and III known blue-to-red CCM can be used. The DPP compounds of formula I or 11 and III may be contained in one layer or may be contained in two different layers, i. e. a green fluorescence conversion film may be laminated with another fluorescence conversion film capable of converting green into red.

An example of an alternative blue-to-green CCM is, for example, a coumarin-type coloring matter such as Coumarin 153 (2,3, 5, 6-1 H, 4H-tetrahydro-8-trifluoromethylquinolidino- (9, 9a, 1-gh) coumarin), Coumarin 6, Coumarin 485, Coumarin, 487, Coumarin 490, Coumarin 498, Coumarin 500, Coumarin 503, Coumarin 504, Coumarin 504T, Coumarin 510, Coumarin 515, Coumarin 519, Coumarin 521, Coumarin 521T, Coumarin 522B, Coumarin 523, Coumarin 525, Coumarin 535, Coumarin 540A, Coumarin 545, Coumarin 545T, quinacridone derivatives such as diethyl pentyl quinacridone and dimethyl quinacridone, or the following CCM materials :

An example of an alternative blue-to-red CCM is, for example, distyrylamine derivatives, such as IDE-102, IDE-105 (Idemitsu Kosan Co. , Ltd. , Tokyo, Japan), rubrene, DCJTB, pyrromethane 546, and mixtures thereof, or cyanine-type coloring matters such as 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl)-4H-pyran (DCM), etc.; pyridine-type coloring matters such as 1-ethyl-2- [4- (p-dimethylaminophenyl)-1, 3-butadienyl]-pyridinium perchlorate (Pyridine 1), etc. ; xanthene-type coloring matters such as Rhodamine B, Rhodamine EG, etc.; as well as oxazine-type coloring matters.

Color changing materials can alternatively also comprise pure polymers or polymer blends, fluorescent polymers or fluorescent compounds doped into conjugated or partly conjugated fluorescent or nonfluorescent polymers. A wide range of polymers and copolymers are available as CCMs because different side groups can be attached to a particular backbone.

In addition, co-polymers can be used. Examples of useful polymers in CCMs are known in the art and include, but are not limited to, PPV polymers, thiophene-based polymers, inert polymers with attached) uminophor side groups, ftuorene-based potymers, phenyiene-based polymers, furylene-based polymers, oligomers, oligomer with spiro centers, and combinations and co-polymers thereof. A blue-to red CCM is, for example, a PPV copolymer with cyano-groups attached to the vinyl groups of the polymer backbone or a poly-alkyl-thiophene polymer. A blue-to-green CCM is, for example, a polyfluorene-based copolymer, a PPV polymer with discontinuous conjugation (i. e. , with electrically and optically inert spacer groups) or a PPV polymer with solubilising side groups, such as a di-alkyl PPV.

CCMs that emit red light preferably have an absolute quantum efficiency of photoluminescence that is greater than about 20%, preferably greater than about 30%, and more preferably greater than about 40%. Such efficiencies can be achieved by multi-component color changing materials, wherein the major component (comprising about 70-98% of the material) absorbs blue light efficiently, the minor component (dopant) has high

quantum efficiency of photoluminescence in the desired wavelength range, and there is efficient energy transfer from the major component to the dopant.

If the CCMs are used without binder polymer, the CCM layers are preferably less than about 3 lim thick, more preferably less than about 2 jim thick, and most preferably less than about 1 lim thick. As the thickness of the CCM layers increases, the layers may waveguide or scatter the light they emit, which in turn may lead to loss of brightness and contrast in the displays.

The invention also provides a fluorescence conversion medium which comprises at least a fluorescent diketopyrrolopyrrole compounds and a binder resin and which can absorb light from a light emitter and can emit visible fluorescence.

The fluorescent conversion medium optionally contains a UV absorbent and a light stabilizer in order to improve the light resistance of the fluorescence conversion medium.

In general, the UV absorbent is grouped into salicylate-type ones, benzophenone-type ones, benzotriazole-type ones, cyanoacrylate-type ones, and other types of UV absorbents.

Examples of salicylate-type UV absorbents are phenyl salicylate, p-octylphenyl salicylate, p-t-butylphenyl salicylate, etc. ; and examples of benzophenone-type UV absorbents are 2,2'- dihydroxy-4-methoxybenzophenone, 2, 2'-dihydroxy-4, 4'-dimethoxybenzophenone, 2, 2', 4, 4'- tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2, 4-dihydroxybenzo- phenone, 2-hydroxy-4-octoxybenzophenone, etc. Examples of benzotriazole-type UV absorbents are 2-(2'-hydroxy-3', s'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-<BR> tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-amyl-5'-<BR> isobutyl phenyl)-5-chlorobenzotriazole, 2'-hydroxy-3'-isobutyl-5'-methylphenyl)-5- chlorobenzotriazole, 2-(2'-hydroxy-3'-isobutyl-5'-propylphenyl)-5-chlorobenzotria zole, 2-(2'- hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2- [2'-hydroxy-5'- (1, 1, 3, 3-tetramethylphenyl] benzotriazole, etc. ; and examples of cyanoacrylate-type UV absorbents are ethyl 2-cyano-3, 3-diphenylacrylate, 2-ethylhexyl 2- cyano-3, 3-diphenylacrylate, etc. Other types of UV absorbents include, for example, resorcinol monobenzoate, 2, 4-di-t-butylphenyl 3, 5-di-t-butyl-4-hydroxybenzoate, N- (2-ethylphenyl)-N'- (2-ethoxy-5-t-butylphenyl) oxalic acid diamide, etc.

In addition to the above-mentioned low-molecular compounds serving as a UV absorbent, further employable herein are reactive UV absorbents having a reactive functional group

such as an acrylic group or the like bonded thereto, polycondensate-type UV absorbents, and polymer-type UV absorbents having an UV absorbent moiety bonded to the polymer main chain.

The light stabilizer includes hindered amines and nickel compounds. Hindered amine-type light stabilizers include, for example, bis (2,2, 6, 6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2, 2,6, 6-tetramethylpiperidine polycondensate, poly [6- (1,1, 3, 3-tetramethylbutyl) imino-1,3, 5-triazine-2, 4-diyl] [(2, 2,6, 6-tetramethyl-4- piperidyl) imino] hexamethylene [2,2, 6, 6-tetramethyl-4-piperidyl) imide], tetrakis (2,2, 6,6- tetramethyl-4-piperidyl) 1,2, 3, 4-butane-tetracarboxylate, 2,2, 6, 6-tetramethyl-4-piperidyl benzoate, bis- (1, 2,6, 6-pentamethyl-4-piperidyl) 2- (3, 5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl malonate, bis- (N-methyl-2, 2,6, 6-tetramethyl-4-piperidyl) sebacate, 1, 1'- (1, 2- ethanediyl) bis (3,3, 5, 5-tetramethylpiperazinone), (mixed 2,2, 6, 6-tetramethyl-4- piperidyl/tridecyl) 1,2, 3, 4-butane-tetracarboxylate, (mixed 1,2, 2,6,6-pentamethyl-4- piperidyl/tridecyl) 1, 2, 3, 4-butane-tetracarboxylate, mixed [2, 6X6-tetramethyl4-piperidyl/ ß,ß,ß', ß'-tetramethyl-3,9-[2, 4, 8, 10-tetroxaspiro (5,5) undecane] diethyl] 1, 2, 3, 4-butane- tetracarboxylate, mixed [1, 2,2, 6, 6-pentamethyl-4-piperiayl/, ßß','-tetramethyl-3, 9-[2, ei, 8, 10- tetroxaspiro (5,5) undecane] diethyl 1,2, 3, 4-butane-tetracarboxylate, N, N'-bis (3- aminopropyl) ethylenediamine-2, 4-bis [N-butyl-N- (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) amino]-6- chloro-1, 3,5-triazine condensate, poly [6-N-morpholyl-1, 3,5-triazine-2, 4-diyl][(2, 2,6, 6- tetramethyl-4-piperidyl) imino] hexamethylene [ (2, 2,6, 6-tetramethyl-4-piperidyl) imide], N, N'- bis (2, 2, 6, 6-tetramethyl-piperidyl) hexamethylenediamine/1, 2-dibromoethane condensate, [N- (2, 2, 6, 6-tetramethyl-4-piperidyl)-2-methyl-2- (2, 2,6, 6-tetramethyl4- piperidyl) iminolpropionamide, etc.

Examples of niczel compounds serving as a light stabilizer are nictel bis (octylphenyl) sulfide, [2,2'-thiobis(4-tert-octylphenolato)]-n-butylamine nickel, nickel dibutyldithiocarbamate, nickel complex-3,5-di-tert-butyl-4-hydroxybenzyl phsophate monoethylate, etc.

One or more of these UV absorbents and light stabilizers may be used either singly or as mixture.

According to the present invention the fluorescent diketopyrrolopyrrole compounds and optional components, UV absorbent and light stabilizer, can optionally be held by fine particles as described in US-B-6, 464, 898. The fine particles include fine particles of various polymers (latexes) and fine particles of inorganic compounds.

To produce the fluorescence conversion medium of the invention, the fluorescent diketopyrrolopyrrole compounds optionally along with a UV absorbent and a light stabilizer is combined with a binder resin, and the resulting dispersion is formed into a film, preferably into a thin film, which is then cured.

One or a multiple number of diketopyrrolopyrroles may be contained in a CCM layer. The total amount of the fluorescent diketopyrrolopyrrole compounds is between 0.1 and 20 % by weight, preferably between 0.3 and 10 % by weight, most preferably between 0.5 and 7 % by weight of the total of the fluorescence conversion medium.

In the above formulations, CCM layers are preferably about 100 um to 0. 5 lit thick, more preferably 50 im to 2 um thick, and most preferably 30 jim to 5 im thick.

The binder resin includes oligomer-type or polymer-type melamine resins, phenolic resins, alkyd resins, epoxy resins, polyurethane resins, maleic acid resins, polyamide resins, as well as polymethyl methacrylate, polyacrylates, polycarbonates, polyvinyl alcohols, polyvinyl pyrrolidones, hydroxyethyl celluloses, carboxymethyl celluloses, etc. One or more of these may be employed either singly or as mixture.

For patterning the fluorescence conversion film, photosensitive resins may be used. The photosensitive resins may be any of photopolymerizable polyacrylates or polymethacrylates having reactive vinyl groups, or photocrosslinkable polyvinyl cinnamates, etc. In general, they are combined with a photosensitizer. If desired, thermosetting resins may also be used, and they are not mixed with a photosensitizer. Anyhow, it is desirable that the binder resin for use in the invention is highly transparent to visible light.

The dispersion liquid for forming the fluorescence conversion medium of the invention is prepared by mixing an appropriate solvent, the fluorescent diketopyrrolopyrrole, optionally along with a UV absorbent and a light stabilizer, and a binder resin in such a manner that the viscosity of the resulting mixture is suitable to forming the intended fluorescence conversion film and to patterning the film. Optionally, the mixture is exposed to ultrasonic waves or is further dispersed by the use of a dispersing machine such as a ball mill, a sand mill, a three-roll mill or the like.

The fluorescence conversion medium, especially the fluorescence conversion film of the invention is produced from the fluorescence conversion film-forming dispersion liquid generally prepared in the manner mentioned above. For example, the dispersion liquid is formed into a film having a predetermined thickness through spin coating, roll coating, casting, electrodeposition or the like, then patterned (into plural layers planarly spaced from each other), and thereafter cured. Alternatively, the fluorescence conversion medium may be incorporated into polymer plates to give fluorescence conversion plates.

To pattern it, the fluorescent conversion film containing a photosensitive resin (resist) as the binder resin may be processed through photolithography. Containing any of photosensitive or non-photosensitive resin, the fluorescent coloring matter dispersion liquid may be applied to a suitable substrate through ordinary printing (relief printing, screen printing, offset printing, intaglio printing).

After having been thus formed, the film or the patterned film may be cured by drying or baking it at a temperature falling between room temperature and 250 °C. In that manner, the intended fluorescence conversion film of the invention that contains a fluorescent coloring matter is obtained.

The following examples further describe some preferred embodiments of the invention, but do not limit the scope of the invention. In the examples, all parts are by weight unless otherwise indicated. <BR> <BR> <BR> <BR> <BR> <BR> <P> Examples<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> Eampte'i 0. 02 g of compound A-18 and 2. 0 g of acryl po) ymer (PMMA : Wako Pure Chemicats Industries, Ltd.) are added to 18 g of toluene and dissolved. The solution is then spin coated on a borosilicate glass plate at 1000 rpm. The coated glass plate is dried for 5 minutes at 80°C on a hot plate, giving a uniform and transparent film.

Film property: Abs.: 472 nm, Fluores. : 528 nm Example 2 Example 1 is repeated except using compound A-45 instead of compound A-18.

Film property: Abs.: 475 nm, Fluores. : 532 nm

Example 3 0.007 g of compound A-45,0. 003 g of compound C-9 and 1.0 g of acryl polymer (PMMA: Wako Pure Chemicals Industries, Ltd.) are added to 10 g of toluene and dissolved. The solution is then spin coated on a borosilicate glass plate at 1000 rpm. The coated glass plate is dried for 5 minutes at 80°C on a hot plate, giving a uniform and transparent film.

Film property: Abs.: 475 nm, Flores. : 597 nm Example 4 0.006 g of compound A-45,0. 004 g of compound C-20 and 1.0 g of acryl polymer (PMMA: Wako Pure Chemicals Industries, Ltd. ) are added into 10 g of toluene and dissolved. The solution is then spin coated on a borosilicate glass plate at 1000 rpm. The coated glass plate is dried for 5 minutes at 80°C on a hot plate, giving a uniform and transparent film.

Film property: Abs.: 475 nm, Fluores. : 605 nm Example 5 Example 3 is repeated except using compound B-40 instead of compound A-45.

Film property: Abs.: 487 nm, Fluores. : 598 nm