CA2062278A1 - Electroluminescent device - Google Patents
Electroluminescent deviceInfo
- Publication number
- CA2062278A1 CA2062278A1 CA002062278A CA2062278A CA2062278A1 CA 2062278 A1 CA2062278 A1 CA 2062278A1 CA 002062278 A CA002062278 A CA 002062278A CA 2062278 A CA2062278 A CA 2062278A CA 2062278 A1 CA2062278 A1 CA 2062278A1
- Authority
- CA
- Canada
- Prior art keywords
- cyanoalkylated
- pullulan
- weight
- nitrogen content
- mixture
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000004373 Pullulan Substances 0.000 claims abstract description 65
- 229920001218 Pullulan Polymers 0.000 claims abstract description 65
- 235000019423 pullulan Nutrition 0.000 claims abstract description 65
- 239000011230 binding agent Substances 0.000 claims abstract description 51
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 45
- 229910002113 barium titanate Inorganic materials 0.000 claims abstract description 37
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims abstract description 35
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 44
- 239000000203 mixture Substances 0.000 claims description 43
- 229920000642 polymer Polymers 0.000 claims description 29
- 229910052757 nitrogen Inorganic materials 0.000 claims description 22
- 229910052739 hydrogen Inorganic materials 0.000 claims description 16
- 239000001257 hydrogen Substances 0.000 claims description 16
- 125000001731 2-cyanoethyl group Chemical group [H]C([H])(*)C([H])([H])C#N 0.000 claims description 12
- 125000000217 alkyl group Chemical group 0.000 claims description 11
- 239000003822 epoxy resin Substances 0.000 claims description 11
- 229920000647 polyepoxide Polymers 0.000 claims description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 10
- 150000002431 hydrogen Chemical class 0.000 claims description 9
- 239000004593 Epoxy Substances 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 125000003118 aryl group Chemical group 0.000 claims description 4
- 229910052736 halogen Inorganic materials 0.000 claims description 4
- 150000002367 halogens Chemical class 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 3
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 3
- 229920002959 polymer blend Polymers 0.000 claims description 3
- 125000004966 cyanoalkyl group Chemical group 0.000 claims description 2
- 229920002678 cellulose Polymers 0.000 claims 4
- 239000001913 cellulose Substances 0.000 claims 4
- 239000011347 resin Substances 0.000 abstract description 25
- 229920005989 resin Polymers 0.000 abstract description 25
- 239000002952 polymeric resin Substances 0.000 abstract description 2
- 229920003002 synthetic resin Polymers 0.000 abstract description 2
- 239000002904 solvent Substances 0.000 description 14
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 12
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 11
- -1 cyano-methyl Chemical group 0.000 description 11
- 239000011888 foil Substances 0.000 description 9
- 239000002002 slurry Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 230000005484 gravity Effects 0.000 description 7
- 239000007858 starting material Substances 0.000 description 7
- ARXJGSRGQADJSQ-UHFFFAOYSA-N 1-methoxypropan-2-ol Chemical compound COCC(C)O ARXJGSRGQADJSQ-UHFFFAOYSA-N 0.000 description 6
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 6
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 6
- 239000003960 organic solvent Substances 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- 150000002170 ethers Chemical class 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 239000002985 plastic film Substances 0.000 description 4
- 239000000376 reactant Substances 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 3
- 229910003437 indium oxide Inorganic materials 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 description 3
- 239000005020 polyethylene terephthalate Substances 0.000 description 3
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 3
- 229910001887 tin oxide Inorganic materials 0.000 description 3
- KXJGSNRAQWDDJT-UHFFFAOYSA-N 1-acetyl-5-bromo-2h-indol-3-one Chemical compound BrC1=CC=C2N(C(=O)C)CC(=O)C2=C1 KXJGSNRAQWDDJT-UHFFFAOYSA-N 0.000 description 2
- 229930185605 Bisphenol Natural products 0.000 description 2
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000005083 Zinc sulfide Substances 0.000 description 2
- 239000012190 activator Substances 0.000 description 2
- 239000003849 aromatic solvent Substances 0.000 description 2
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- FDPIMTJIUBPUKL-UHFFFAOYSA-N dimethylacetone Natural products CCC(=O)CC FDPIMTJIUBPUKL-UHFFFAOYSA-N 0.000 description 2
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 2
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 2
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 2
- 125000000740 n-pentyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 2
- 125000004123 n-propyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])* 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 229910052984 zinc sulfide Inorganic materials 0.000 description 2
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 2
- OAYXUHPQHDHDDZ-UHFFFAOYSA-N 2-(2-butoxyethoxy)ethanol Chemical compound CCCCOCCOCCO OAYXUHPQHDHDDZ-UHFFFAOYSA-N 0.000 description 1
- SBASXUCJHJRPEV-UHFFFAOYSA-N 2-(2-methoxyethoxy)ethanol Chemical compound COCCOCCO SBASXUCJHJRPEV-UHFFFAOYSA-N 0.000 description 1
- CUDYYMUUJHLCGZ-UHFFFAOYSA-N 2-(2-methoxypropoxy)propan-1-ol Chemical compound COC(C)COC(C)CO CUDYYMUUJHLCGZ-UHFFFAOYSA-N 0.000 description 1
- WAEVWDZKMBQDEJ-UHFFFAOYSA-N 2-[2-(2-methoxypropoxy)propoxy]propan-1-ol Chemical compound COC(C)COC(C)COC(C)CO WAEVWDZKMBQDEJ-UHFFFAOYSA-N 0.000 description 1
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 description 1
- TVONJMOVBKMLOM-UHFFFAOYSA-N 2-methylidenebutanenitrile Chemical compound CCC(=C)C#N TVONJMOVBKMLOM-UHFFFAOYSA-N 0.000 description 1
- XCKPLVGWGCWOMD-YYEYMFTQSA-N 3-[[(2r,3r,4s,5r,6r)-6-[(2s,3s,4r,5r)-3,4-bis(2-cyanoethoxy)-2,5-bis(2-cyanoethoxymethyl)oxolan-2-yl]oxy-3,4,5-tris(2-cyanoethoxy)oxan-2-yl]methoxy]propanenitrile Chemical compound N#CCCO[C@H]1[C@H](OCCC#N)[C@@H](COCCC#N)O[C@@]1(COCCC#N)O[C@@H]1[C@H](OCCC#N)[C@@H](OCCC#N)[C@H](OCCC#N)[C@@H](COCCC#N)O1 XCKPLVGWGCWOMD-YYEYMFTQSA-N 0.000 description 1
- 244000019459 Cynara cardunculus Species 0.000 description 1
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- NYZGMENMNUBUFC-UHFFFAOYSA-N P.[S-2].[Zn+2] Chemical compound P.[S-2].[Zn+2] NYZGMENMNUBUFC-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 125000004093 cyano group Chemical group *C#N 0.000 description 1
- 238000007278 cyanoethylation reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 1
- XXJWXESWEXIICW-UHFFFAOYSA-N diethylene glycol monoethyl ether Chemical compound CCOCCOCCO XXJWXESWEXIICW-UHFFFAOYSA-N 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000295 emission spectrum Methods 0.000 description 1
- 239000008393 encapsulating agent Substances 0.000 description 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 229910052981 lead sulfide Inorganic materials 0.000 description 1
- 229940056932 lead sulfide Drugs 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229940043265 methyl isobutyl ketone Drugs 0.000 description 1
- 229930014626 natural product Natural products 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 239000003791 organic solvent mixture Substances 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920005596 polymer binder Polymers 0.000 description 1
- 239000002491 polymer binding agent Substances 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 239000012704 polymeric precursor Substances 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000007761 roller coating Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 235000000346 sugar Nutrition 0.000 description 1
- 150000008163 sugars Chemical class 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- FYGDTMLNYKFZSV-BYLHFPJWSA-N β-1,4-galactotrioside Chemical group O[C@@H]1[C@@H](O)[C@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@H](CO)O[C@@H](O[C@@H]2[C@@H](O[C@@H](O)[C@H](O)[C@H]2O)CO)[C@H](O)[C@H]1O FYGDTMLNYKFZSV-BYLHFPJWSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/02—Use of particular materials as binders, particle coatings or suspension media therefor
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
- C08B37/0006—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid
- C08B37/0009—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid alpha-D-Glucans, e.g. polydextrose, alternan, glycogen; (alpha-1,4)(alpha-1,6)-D-Glucans; (alpha-1,3)(alpha-1,4)-D-Glucans, e.g. isolichenan or nigeran; (alpha-1,4)-D-Glucans; (alpha-1,3)-D-Glucans, e.g. pseudonigeran; Derivatives thereof
- C08B37/0018—Pullulan, i.e. (alpha-1,4)(alpha-1,6)-D-glucan; Derivatives thereof
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/12—Light sources with substantially two-dimensional radiating surfaces
- H05B33/20—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/12—Light sources with substantially two-dimensional radiating surfaces
- H05B33/22—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biochemistry (AREA)
- Molecular Biology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- General Health & Medical Sciences (AREA)
- Electroluminescent Light Sources (AREA)
- Luminescent Compositions (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Cyanoalkylated pullulan polymeric resins and their admixtures with other cyanoalkylated resins are useful as dielectric binders in electroluminescent devices. The resins can be used in either the phosphor/binder layer or the barium titanate/binder layer or both. The resultant electrolumines-cent devices have improved brightness.
Cyanoalkylated pullulan polymeric resins and their admixtures with other cyanoalkylated resins are useful as dielectric binders in electroluminescent devices. The resins can be used in either the phosphor/binder layer or the barium titanate/binder layer or both. The resultant electrolumines-cent devices have improved brightness.
Description
IMPROVED ELECTROLUMINESCENT DEVICE
This invention relates to improved electroluminescent devices. More particularly, this invention relates to electroluminescent devices having improved luminescence and lifetimes.
BACKGROUND OF THE INVENTION
Electroluminescent devices are comprised of two electrodes, one of which is transparent, with a phosphor layer therebetween. When a source of electric current is applied to the electrodes, the phosphors become activated and emit visible photons or light. The emission spectrum and wavelength generated by the phosphors is controlled by the activator element in the phosphor. The amount of light emitted by the device is controllable by the amount of current applied.
Generally the more current that is applied, the more intense the light that is emitted, within certain limits.
The phosphors are highly sensitive to moisture and to heat, including the heat they themselves generate during emission. Thus in order to protect the phosphors, it has become the practice to mix them in a solvent-based high dielectric constant binder, such as an organic polymeric matrix, dissolved in a solvent. The polymer encapsulates the phosphor particles and binds them together. The organic solvent is then evaporated. A separate insulating layer of a high dielectric constant material such as barium titanate also acts as . , :
20622~8 protection for the phosphor layer. The barium titanate can also be mixed with a high dielectric constant polymeric binder medium in similar fashion.
The manufacture of these electroluminescent devices has also been improved over the years. The barium titanate/binder and phosphorJbinder layers are deposited separately as thin layers onto flexible electrodes made of metal foils and plastic films coated with a transparent conductive layer respectively.
The layers are assembled and the assembly is laminated together by inserting between plastic sheets as, for example, sheets of polyester or polycarbonate, and these are sealed using heat and pressure to form a final flexible hermetically sealed package.
Leads can be attached to the electrodes either before or after assembly of the device.
lS Several high dielectric constant polymeric binder materials have been suggested as phosphor encapsulants heretofore. In U.S. Patent 3,238,407, Jaffe discloses cyanoethyl cellulose as the polymeric binder material. However, this material diminishes the intensity of emitted light in electroluminescent devices and thus is less than satisfactory.
Takahashi in U.S. Patent 3,389,286 describes the use of cyanoethylated polyvinyl alcohol as a dielectric binder layer;
however, this material partially dissolves the phosphor and also diminishes the light intensity of the electroluminescent devices.
.
; ~:
This invention relates to improved electroluminescent devices. More particularly, this invention relates to electroluminescent devices having improved luminescence and lifetimes.
BACKGROUND OF THE INVENTION
Electroluminescent devices are comprised of two electrodes, one of which is transparent, with a phosphor layer therebetween. When a source of electric current is applied to the electrodes, the phosphors become activated and emit visible photons or light. The emission spectrum and wavelength generated by the phosphors is controlled by the activator element in the phosphor. The amount of light emitted by the device is controllable by the amount of current applied.
Generally the more current that is applied, the more intense the light that is emitted, within certain limits.
The phosphors are highly sensitive to moisture and to heat, including the heat they themselves generate during emission. Thus in order to protect the phosphors, it has become the practice to mix them in a solvent-based high dielectric constant binder, such as an organic polymeric matrix, dissolved in a solvent. The polymer encapsulates the phosphor particles and binds them together. The organic solvent is then evaporated. A separate insulating layer of a high dielectric constant material such as barium titanate also acts as . , :
20622~8 protection for the phosphor layer. The barium titanate can also be mixed with a high dielectric constant polymeric binder medium in similar fashion.
The manufacture of these electroluminescent devices has also been improved over the years. The barium titanate/binder and phosphorJbinder layers are deposited separately as thin layers onto flexible electrodes made of metal foils and plastic films coated with a transparent conductive layer respectively.
The layers are assembled and the assembly is laminated together by inserting between plastic sheets as, for example, sheets of polyester or polycarbonate, and these are sealed using heat and pressure to form a final flexible hermetically sealed package.
Leads can be attached to the electrodes either before or after assembly of the device.
lS Several high dielectric constant polymeric binder materials have been suggested as phosphor encapsulants heretofore. In U.S. Patent 3,238,407, Jaffe discloses cyanoethyl cellulose as the polymeric binder material. However, this material diminishes the intensity of emitted light in electroluminescent devices and thus is less than satisfactory.
Takahashi in U.S. Patent 3,389,286 describes the use of cyanoethylated polyvinyl alcohol as a dielectric binder layer;
however, this material partially dissolves the phosphor and also diminishes the light intensity of the electroluminescent devices.
.
; ~:
2~62278 In U.S. Patent 4,560,902, Kardon describes a thermoplastic epo~y as the polymeric binder layer. This epoxy is prepared by reacting a resin, such as a urethane or epoxy resin, with the reaction product of an epihalohydrin and a bisphenol in certain proportions to form a resin having a molecular weight of about 450-75,000.
The above electroluminescent devices, while satisfactory, like all electroluminescent devices are limited in the amount of light they produce. It would be highly desirable to increase the brightness of the light emitted by these devices without increasing the thickness of the layers or the amount of relatively expensive phosphors required.
SUMMARY OF THE IN~ENTION
We have found that particular cyanoalkylated pullulan polymers, when employed as a high dielectric constant polymeric binder in electroluminescent devices, significantly increases the amount of light emitted by the devices.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is a perspective view of a multilayered electroluminescent device of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Electroluminescent devices comprising a phosphor layer on a transparent electrode and a dielectric layer on a metallic electrode wherein pullulan polymers are present as a binder in one or both layers, have significantly increased brightness or light emission over conventional electroluminescent devices.
These polymers can be employed in conventional coating and lami-nation processes without modification and provide excellent ad-hesion to either or both of the phosphor and dielectric layers.
206~278 The cyanoalkylated pullulan polymer binder materials which may be employed in this invention include the following:
H~O~H H~ O~IH H~ 0 XO~ ~~ 0~ 0-X H OX H X
_ ~CH2 CH20X C~20X
H/l-- 11 H /~0 H H~o H
~/ H \1 1/ H \¦ V H \l LXO~O ~ ~_o_ _ ~
H OX H OX H OX n 15 CH2 CH20X CHzOX
H~ O~H Hk O~H H~O~H
XO~ ~ ~OX
H OX OX H OX
wherein n is an integer of from about 20 to about 4000 and X in each occurrence is hydrogen or cyano lower alkyl as, for example straight or branched chain lower alkyl of 1-5 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, n-pentyl and the like. Preferably, X represents hydrogen, cyano-methyl or cyanoethyl.
The-cyanoalkylated pullulan polymers are known compounds which are described in U.S. Patent No. 4,322,524. They are naturally occurring products in which the recurring malto-triose units are interactive and may be readily cyanoethylated ~" ' .
~0~2278 when reacted with an acrylonitrile in the presence of an alkali catalyst. The degree of cyanoethylation is controllable by the reaction conditions and can reach 90% or higher.
Mixtures of the above cyanoalkylated pullulan polymers with other cyanoalkylated resins such as cyanoalkylatedpolyvinyl alcohol, cyanoalkylcellulose, ~yanoalkylsucrose, other cyanoalkylated sugars and starches, and cyanoalkylhydroxycellulose can also be employed. Certain mixtures of these cyanoalkylated resins with cyanoalkylated pullulan are available from Shin Etsu of Japan under the trademark Cyepl resins. Cyanoethyl pullulan, CR-S, has a nitrogen content of from 11.8-13.0% by weight, a specific gravity of 1.25 and a softening temperature of about 90-110C.
A mixture of cyanoethyl pullulan and cyanoethylcellulose, CR-C, has a nitrogen content of about 11.8-13.0% by weight, a specific gravity of 1.27 and a softening temperature greater than 270C. A mixture of cyanoethyl pullulan and cyanoethylpolyvinyl alcohol, CR-V, has a nitrogen content of about 12.2-13.5% by weiqht, a specific gravity of 1.27 and a softening temperature of about 20-40C. A mixture of cyanoethyl pullulan and cyanoethyl sucrose, CR-U, has a nitrogen content of about 14.4% by weight, a specific gravity of about 1.24 and is a liquid at room temperature. A mixture of cyanoethyl pullulan and cyanoethyl hydroxycellulose, CR-E, has a nitrogen content of about 9.0-10.9% by weight, a specific gravity of about 1.30 and a softening temperature of about 55-65C. The _5_ .
.
~ .
' relative amount of cyanoalkylation can be varied by the reaction conditions.
Cyanoalkylated polymers derived from a urethane or epoxy reacted with the reaction product of a bisphenol such as bisphenol A and an epihalohydrin in known manner are also useful as the cyanoalXylated resins in admixture with cyanoalkylated pullulan polymers. These resins have the formula ¦ X c~oc~2~ c112 X' X' m wherein R and R' can be independently hydrogen, lower alkyl and mononuclear aryl; X and X' are independently hydrogen, lower alkyl, or halogen; R" can be hydrogen or a cyanoloweralkyl, for example straight or branched chain lower alkyl of 1-5 carbon atoms, including methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, n-pentyl and the like; and m is an integer greater than 1. The degree of cyanoalkylation can be varied by varying the amount of the acrylonitrile reactant.
The pullulan polymers and their admixture with other cyanoalkylated resins are made by reaction of the hydroxy-containing precursors of the pullulan polymers with an acrylonitrile in known manner.
Suitable acrylonitrile reactants include acrylonitrile, crotonacrylonitrile, 2,2-dimethylacrylonitrile, 2-methyl-2-. ' ' ' " , ~ .
.: ~
ethylacrylonitrile and the like. The cyanoalkyl groups react with the hydroxyl groups of the polymeric precursors described above.
The amount of acrylonitrile reactant can vary depending upon the degree of cyanoalkylation desired. In order to obtain cyanoalkylation of about 50% of the available hydroxyl groups, about 3-5 moles of acrylonitrile is used per mol of hydroxy units in the starting hydroxy-containing compounds. If an excess of acrylonitrile is employed, it also acts as a solvent for the starting material.
Although the following described process is directed to the preparation of cyanoalkylated pullulan resins, cyanoalkylation of other hydroxy-containing polymers is carried out in similar manner.
The reaction between a pullulan natural product which can vary in molecular weight from about 50,000 to about 2,000,000, and an acrylonitrile occurs either by dissolving the pullulan starting material in an aqueous alkali solution and adding an acrylonitrile in an organic solvent, whereby the reaction proceeds read~ly at room temperature or by dispersing the starting material pullulan in a solution of an acrylonitrile in an organic solvent and adding an a~ueous solution of an alkali and heating to a temperature of about 40-60C. The relative i amounts of the reactants and alkali can be varied to control the amount of cyanoalkylation of the pullulan starting material. For example, when pullulan or other starting material is dissolved in a sodium hydroxide solution, the concentration of starting material can be about 2-20~ by weight in a sodium hydroxide solution of about 2-20% by weight in water. When sodium hydroxide is added to an organic solvent mixture, the hydroxide suitably has a concentration of about 10-50% by weight in water, and from about 1-10% by weight of sodium hydroxide based on the pullulan starting material can be employed. The cyanoalkylated pullulan resin is collected by neutralizing the reaction mixture with acid and diluting with water to precipitate the cyanoalkylated pullulan. The product can be further purified by washing with water, or can be dissolved in a ketone such as acetone and reprecipitated with water. The material is then dried.
The cyanoalkylated pullulan resin is soluble in organic solvents and thus materials such as barium titanate and phosphors can be readily admixed therewith. Suitable cyanoalkylated pullulan polymers have softening points of from about 20-110C, and is preferably about 90C. The nitrogen content can vary from about 4-20 weight % and is preferably about 12 weight %.
The cyanoalkylated pullulan resin can be admixed in various proportions with other cyanoalkylated resins such as those described above.
The cyanoalkylated polymers are soluble in various organic solvents including glycol ethers, alkyl ketones or aromatic solvents. Suitable ethers include glycolalkyl ethers .. . :
: '~` ~
such as propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether and diethylene glycol butyl ether. These ethers are colorless liquids which combine the properties of alcohols, ethers and hydrocarbons. They are miscible with most organic solvents and they are excellent solvents for mixing with the phosphor and barium titanate components of electroluminescent devices.
Suitable alkyl ketones and aromatic solvents which can also be employed as solvents include lower alkyl ketones such as acetone, methyl ethyl ketone, ethyl ketone and methylisobutyl ketone, toluene, xylene and the like.
In making the barium titanate layer, the barium titanate solid is first admixed with a suitable solvent as described above. The amount of barium titanate which is added to the glycol ether or other solvent is preferably about 70-~0% by weight. The barium titanate and the solvent are stirred together to form a homoqeneous slurry. To this slurry is added from 10 to 30 parts of a binder, including a cyanoalkylated polymer resin as described above which can also be in a like solvent. After mixing thoroughly, the barium titanate-binder-solvent slurry is deposited onto a metal foil or other electrode and dried. Suitably a barium titanate/resin binder layer ~hickness when dried is from about 2-6 mils.
.:
_g_ -"' 2~62278 The phosphor is also first admixed with a suitable sol~ent and mixed well. Suitable phosphors are luminescent unde~r the influence of an electric current, as for example zinc sulfide, zinc oxide or zinc sulfide activated with manganese, copper, copper/lead or copper/manganese mixtures. The amount of phosphor added to the solvent can range suitab'y from about 60-95% by weight of the mixture, and is preferably from about 75-85% by weight. ~he light emitted by the electroluminescent cell is at least partially dependent upon the particle size and concentration of phosphor in the cyanoalkylated polymer. The maximum amount of phosphor is added consistent with there being sufficient amount of binder present to encapsulate the phosphor to protect it from moisture. After mixing well, from 5 to 40 parts of a binder is also added to the phosphor slurry. The resultant phosphor slurry is deposited onto a transparent electrode in known manner. A suitable phosphor/binder layer ; thickness when dried is from about 2-6 mils.
The phosphor-containing and barium titanate-containing ; slurries can be deposited onto their respective electrodes by spray coating, roller coating, painting or hot presssing techniques known in the art. The thickness of the deposited layers may be varied to provide optimum light emitting effects.
The electrodes of the present electroluminescent devices ~; include a transparent electrode, which can be of transparent plastic film or sheet such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, ::`
` ~. .
~: :
, , polymethylmethacrylate and the liXe, or of glass. The transparent film or glass is coated with a transparent conductive film, such as an indium-tin oxide film, as is known.
The other electrode is of a conductive metal, such as aluminum, gold, silver, copper, in a variety of thicknesses, from a thick sheet to a thin foil.
The two parts of the electroluminescent cell as described above, i.e., the barium titanate/binder layer on a metal electrode and the phosphor/binder layer on a transparent electrode, are assembled by hot pressing at temperatures in the range of about 150-400F at a pressure of from about S-lO0 psi for a period of about 0.1-2.0 seconds. Electrical leads or connections are made to the electrodes and then connected to a source of electrical current. When an electrical current is passed across the electrodes, the phosphor particles are activated and light is emitted from the cell. In accordance with the invention, at least one of the phosphor layers or barium titanate layers contains a cyanoalkylated pullulan resin or resin mixture as the binder.
The assembled electroluminescent device lO is shown in Fig. 1 wherein a barium titanate/binder layer 14 is deposited onto an aluminum foil 12 and a phosphor/binder layer 16 is deposited onto an indium-tin oxide coated polymer film 18.
Leads 20 complete the device lO.
The electroluminescent devices of the invention, having at least one o~ the phosphor/binder and barium titanate/binder .
.
: ~ -2o6~278 layers containing as a binder a cyanoalkylated pullulan resin or mixture thereof, unexpectedly have high intensity light emission, much higher than that of conventional electroluminescent devices. The presence of the high dielectric constant cyanoethylated pullulan polymers and mixtures in the present devices increases the brightness achievable with these devices. Increased brightness is achieved with the binders of the invention providing pullulan polymer is added to one or more of the layers of the electroluminescent device even when conventional binders, such as epoxy resins, are used as a binder in one of the layers of the electroluminescent device, or as a portion of the binder in either layer. This result was highly unexpected. Further, these resins are able to be used in commercial coating and lamination processes without modification, and provide adequate adhesion to both the phosphor and barium titanate components.
The invention will be further illustrated by the following examples, but the invention is not meant to be limited to the details described therein. In the Examples, parts and percentages are by weight.
,' ' ' ' .
206~27~
Pullulan-Phosphor Modified Lamp A mixture was made from 10.24 grams of a binder comprised of a mixture of cyanoethyl pullulan resin and cyanoethylpolyvinyl alcohol available as Cyepl 02 from Shin Etsu of Japan. This resin as a 20% solution in dimethylformamide had a viscosity of 240-260 centipoises; a nitrogen content of between 12.2 and 13.5: a specific gravity of 1.27 and a softening temperature of 20-40C. The binder was mixed in a 50:50 weight ratio of about one part binder to two parts of solvent. To this mixture was added 43.64 grams of zinc sulfide phosphor containing a copper activator.
The resultant slurry was cast onto a series of polyethylene terephthalate tapes having an indium/tin oxide conductive layer thereon in varying thickness.
A control series of tapes was made using a standard phosphor slurry containing the resin D.E.R. 684-EK40, as described in U.S. Patent 4,560,902 to Xardon. D.E.R.-EK40 is an ultra high molecular weight epoxy resin derived from the reaction of bisphenol A and epichlorohydrin, and is a registered trademark of the Dow Chemical Company, Midland, Michigan.
Both series of tapes were dried and laminated to an aluminum foil having a layer of barium titanate in standard epoxy binder thereon. The layers were passed several times through a heat sealing laminator and brightness measured in foot-lamberts at 120 Volts, 400 Hz. The data are summarized in Table I below:
Film __ Brightness, foot-lamberts Thickness mils Pass 1Pass 2 Pass 3 Pass 4 Pass 5 Control 1.45 7.~ 7.58.5 8.89.6 9.6 10.3 10.1 10.3 10.1 1.60 9.4 9.410.4 10.411.3 11.5 11.9 12.2 12.0 11.0 1.90 9.6 9.710.4 10.511.0 10.5 2.25 8.9 9.69.7 10.0 Example 1 1.65 11.3 12.9 13.1 14.4 15.1 16.~ 16.2 16.2 17.9 17.2 2.00 12.9 11.7 13.9 15.2 15.7 16.9 16.9 17.6 17.9 18.3 2.35 14.4 15.4 16.3 16.5 16.7 16.9 2.75 14.8 14.9 ! 3.10 12.7 13.2 14.2 14.9 14.6 15.2 14.6 13.8 Thus it is apparent that when the resin of the invention was mixed with the phosphor layer alone, the brightness of the electroluminescent cells improved significantly.
Pullulan-Barium Titanate Modified Lamp Barium titanate (18.84 grams) was admixed with the cyanoethyl pullulan/cyanoethylpoly~inyl alcohol binder of Example 1 (31.0fi grams) in 15 grams of a 50:50 blend of acetone and methyl ethyl ketone solvent. The resultant slurry was deposited onto aluminum foil at varying thickness, dried and laminated to a conventional phosphor coating 4 mils thick using an epoxy binder on an indium/tin oxide polyethylene tape.
., .
. ' .
.. ~, : .
.' - . ' ' .
` 2062278 The electroluminescent cells were passed through the laminator three times, and the brightness measured after each pass as in Example 1. The results are tabulated below in Table II.
TABLE II
Layer Brightness. foot-lamberts Thickness, ; mils Pass I Pass 2 Pass 3 2 15.5 16.2 15.9 16.6 18.0 17.2 3 17.4 17.5 19.4 18.8 19.8 18.8 4 19.0 18.7 21.7 20.2 21.8 20.3 18.8 18.0 20.7 19.5 20.8 19.7 6 17.9 17.9 20.0 20.5 20.3 20.8 It is apparent that improved brightness is obtained when the cyanoalkylated pullulan binder of the invention is present in the barium titanate layer alone as well.
; 20 Pullulan-Phos~hor and Pullulan-Barium Titanate Modified Lamp The binder employed in Examples 1 and 2 was used to make both the phosphor layers and the barium titanate layers of electroluminescent cells. In the first group of cells, the layer thickness of the barium titanate layer was varied and the ; 25 phosphor layer was maintained at 4 mils; in the second group of cells, the barium titanate was maintained at 5 mils and the phosphor layer thickness was varied. The cells were passed through a laminating process three times and the brightness measured after each pass as in Example 1. The results are summarized in Table III below.
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.
- . , ~ `
.
,: . . : . . .
2~62~78 TABLE III
Layer Brightness. foot-lamberts Thickness.
Mils Pass l Pass 2 Pass 3 Group l 3 2~.4 30.0 29.4 30.0 30.2 29.3 4 30.0 29.6 33.3 32.8 35.8 34.7 31.0 30.5 32.6 34.0 34.0 35.4 6 30.8 30.6 32.2 32.7 34.8 34.9 Group 2 2 30.7 31.4 34.8 34.5 38.2 37.5 3 34.1 33.4 35.6 35.2 36.1 35.4 4 31.4 32.0 32.1 33.9 35.7 34.1 31.3 31.7 33.0 33.5 34.6 34.4 It is apparent that the brightness of the above electroluminescent cells is far superior to conventional cells, and the brightness is increased when both the barium titanate and phosphor layers use the binder of the invention.
Several electroluminescent cells were made varying the phosphor and barium titanate layers and the laminating conditions. A phosphor layer of Example l was deposited to a thickness of 2.3 mils, and a control standard phosphor layer using epoxy binder was deposited in a thickness of 1.75 mils.
The barium titanate/binder mixture of Example 2 was deposited onto 1.5 mil thick aluminum foil in a thickness of 1.3 mils, and a control barium titanate/conventional epoxy binder was deposited onto aluminum foil in a thickness of 1.3 mils. Cells A were laminated using a standard phosphor/epoxy resin binder ;~ , ' , ' , ' , ~ ' : . ' and the barium titanate/binder mixture of Example 2; thus the pullulan polymer was present in only one layer, the barium titanate layer. Cells B were laminated using pullulan in both the phosphor/binder and barium titanate/binder layers of Examples 1 and 2. The control used the standard epoxy binder containing phosphor and barium titanate layers. The brightness was measured as in Example 1. The results are summarized in Tables IV and V below.
TABLE IV *
Temperature. Briahtness._foot-lamberts F Control Cells A Cells B
200 11.2 22.0 29.7 240 12.5 24.5 26.8 275 12.4 26.8 39.3 Pressure was constant at 60 lbs.
TABLE V **
Pressure. Brightness. foot-lamberts lbs Control Cells A Cells B
9.5 18.9 27.2 11.1 24.3 26.8 27.2 31.9 39.3 ** Temperature was constant at 175F.
Thus the electroluminescent devices containing pullulan had increased brightness over conventional electroluminescent devices containing binders of conventional epoxy resins.
Electroluminescent devices containing pullulan in both the phosphor layer and the dielectric layer had the greatest briqhtness.
., ~ -17-.
" , .:
-:
An electroluminescent cell was made using 87 grams of lead sulfide phosphor admixed with 15 grams of cyanoalkylated pullulan having a nitrogen content of about 12% and a softening temperature in the range 90-110F in dimethylformamide. The resultant solution at 20C had a viscosity of 240-360 centipoises. The specific gravity of the solution was 1.25.
Propylene glycol methyl ether was used as a solvent.
Layers varying in thickness were applied to a transparent indium/tin oxide on polyethylene terephthalate sheet. The mixture was dried in an oven at 120C.
A layer of barium titanate mixed with cyanoethylated pullulan as above (85 grams of barium titanate per 15 grams of pullulan resin) in propylene glycol methyl ether and deposited - on an aluminum foil and dried in an oven at 120C.
The two layers were compressed together at 150 psi ` pressure at 150C, leads attached, and the cell joined to a source o~ 120 volt AC current. The cells were tested as follows:
~'~
, ., ~.
Thickness. mils Power Foot-Lamberts 1.60 120V,400Hz 30.0 140V,600Hz 44.5 1."5 120V,400Hz 29.6 75V,600Hz 22.7 1.35 120V,400Hz 33.0 75V,600Hz 20.9 1.05 120V,400Hz 30.9 75V,600Hz 21.9 0.80 120V,400Hz 23.1 75Y,600Hz 20.5 The above electroluminescent devices all had excellent brightness. Thus the addition of pullulan polymers and polymer mixtures unexpectedly improves the brightness of electroluminescent devices.
This invention has been described by reference to precise embodiments but it will be appreciated by those skilled in the art that this invention is subject to various modifications and to the extent that those modifications would be obvious to one of ordinary skill they are considered as being within the scope of the appended claims.
:: .
The above electroluminescent devices, while satisfactory, like all electroluminescent devices are limited in the amount of light they produce. It would be highly desirable to increase the brightness of the light emitted by these devices without increasing the thickness of the layers or the amount of relatively expensive phosphors required.
SUMMARY OF THE IN~ENTION
We have found that particular cyanoalkylated pullulan polymers, when employed as a high dielectric constant polymeric binder in electroluminescent devices, significantly increases the amount of light emitted by the devices.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is a perspective view of a multilayered electroluminescent device of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Electroluminescent devices comprising a phosphor layer on a transparent electrode and a dielectric layer on a metallic electrode wherein pullulan polymers are present as a binder in one or both layers, have significantly increased brightness or light emission over conventional electroluminescent devices.
These polymers can be employed in conventional coating and lami-nation processes without modification and provide excellent ad-hesion to either or both of the phosphor and dielectric layers.
206~278 The cyanoalkylated pullulan polymer binder materials which may be employed in this invention include the following:
H~O~H H~ O~IH H~ 0 XO~ ~~ 0~ 0-X H OX H X
_ ~CH2 CH20X C~20X
H/l-- 11 H /~0 H H~o H
~/ H \1 1/ H \¦ V H \l LXO~O ~ ~_o_ _ ~
H OX H OX H OX n 15 CH2 CH20X CHzOX
H~ O~H Hk O~H H~O~H
XO~ ~ ~OX
H OX OX H OX
wherein n is an integer of from about 20 to about 4000 and X in each occurrence is hydrogen or cyano lower alkyl as, for example straight or branched chain lower alkyl of 1-5 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, n-pentyl and the like. Preferably, X represents hydrogen, cyano-methyl or cyanoethyl.
The-cyanoalkylated pullulan polymers are known compounds which are described in U.S. Patent No. 4,322,524. They are naturally occurring products in which the recurring malto-triose units are interactive and may be readily cyanoethylated ~" ' .
~0~2278 when reacted with an acrylonitrile in the presence of an alkali catalyst. The degree of cyanoethylation is controllable by the reaction conditions and can reach 90% or higher.
Mixtures of the above cyanoalkylated pullulan polymers with other cyanoalkylated resins such as cyanoalkylatedpolyvinyl alcohol, cyanoalkylcellulose, ~yanoalkylsucrose, other cyanoalkylated sugars and starches, and cyanoalkylhydroxycellulose can also be employed. Certain mixtures of these cyanoalkylated resins with cyanoalkylated pullulan are available from Shin Etsu of Japan under the trademark Cyepl resins. Cyanoethyl pullulan, CR-S, has a nitrogen content of from 11.8-13.0% by weight, a specific gravity of 1.25 and a softening temperature of about 90-110C.
A mixture of cyanoethyl pullulan and cyanoethylcellulose, CR-C, has a nitrogen content of about 11.8-13.0% by weight, a specific gravity of 1.27 and a softening temperature greater than 270C. A mixture of cyanoethyl pullulan and cyanoethylpolyvinyl alcohol, CR-V, has a nitrogen content of about 12.2-13.5% by weiqht, a specific gravity of 1.27 and a softening temperature of about 20-40C. A mixture of cyanoethyl pullulan and cyanoethyl sucrose, CR-U, has a nitrogen content of about 14.4% by weight, a specific gravity of about 1.24 and is a liquid at room temperature. A mixture of cyanoethyl pullulan and cyanoethyl hydroxycellulose, CR-E, has a nitrogen content of about 9.0-10.9% by weight, a specific gravity of about 1.30 and a softening temperature of about 55-65C. The _5_ .
.
~ .
' relative amount of cyanoalkylation can be varied by the reaction conditions.
Cyanoalkylated polymers derived from a urethane or epoxy reacted with the reaction product of a bisphenol such as bisphenol A and an epihalohydrin in known manner are also useful as the cyanoalXylated resins in admixture with cyanoalkylated pullulan polymers. These resins have the formula ¦ X c~oc~2~ c112 X' X' m wherein R and R' can be independently hydrogen, lower alkyl and mononuclear aryl; X and X' are independently hydrogen, lower alkyl, or halogen; R" can be hydrogen or a cyanoloweralkyl, for example straight or branched chain lower alkyl of 1-5 carbon atoms, including methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, n-pentyl and the like; and m is an integer greater than 1. The degree of cyanoalkylation can be varied by varying the amount of the acrylonitrile reactant.
The pullulan polymers and their admixture with other cyanoalkylated resins are made by reaction of the hydroxy-containing precursors of the pullulan polymers with an acrylonitrile in known manner.
Suitable acrylonitrile reactants include acrylonitrile, crotonacrylonitrile, 2,2-dimethylacrylonitrile, 2-methyl-2-. ' ' ' " , ~ .
.: ~
ethylacrylonitrile and the like. The cyanoalkyl groups react with the hydroxyl groups of the polymeric precursors described above.
The amount of acrylonitrile reactant can vary depending upon the degree of cyanoalkylation desired. In order to obtain cyanoalkylation of about 50% of the available hydroxyl groups, about 3-5 moles of acrylonitrile is used per mol of hydroxy units in the starting hydroxy-containing compounds. If an excess of acrylonitrile is employed, it also acts as a solvent for the starting material.
Although the following described process is directed to the preparation of cyanoalkylated pullulan resins, cyanoalkylation of other hydroxy-containing polymers is carried out in similar manner.
The reaction between a pullulan natural product which can vary in molecular weight from about 50,000 to about 2,000,000, and an acrylonitrile occurs either by dissolving the pullulan starting material in an aqueous alkali solution and adding an acrylonitrile in an organic solvent, whereby the reaction proceeds read~ly at room temperature or by dispersing the starting material pullulan in a solution of an acrylonitrile in an organic solvent and adding an a~ueous solution of an alkali and heating to a temperature of about 40-60C. The relative i amounts of the reactants and alkali can be varied to control the amount of cyanoalkylation of the pullulan starting material. For example, when pullulan or other starting material is dissolved in a sodium hydroxide solution, the concentration of starting material can be about 2-20~ by weight in a sodium hydroxide solution of about 2-20% by weight in water. When sodium hydroxide is added to an organic solvent mixture, the hydroxide suitably has a concentration of about 10-50% by weight in water, and from about 1-10% by weight of sodium hydroxide based on the pullulan starting material can be employed. The cyanoalkylated pullulan resin is collected by neutralizing the reaction mixture with acid and diluting with water to precipitate the cyanoalkylated pullulan. The product can be further purified by washing with water, or can be dissolved in a ketone such as acetone and reprecipitated with water. The material is then dried.
The cyanoalkylated pullulan resin is soluble in organic solvents and thus materials such as barium titanate and phosphors can be readily admixed therewith. Suitable cyanoalkylated pullulan polymers have softening points of from about 20-110C, and is preferably about 90C. The nitrogen content can vary from about 4-20 weight % and is preferably about 12 weight %.
The cyanoalkylated pullulan resin can be admixed in various proportions with other cyanoalkylated resins such as those described above.
The cyanoalkylated polymers are soluble in various organic solvents including glycol ethers, alkyl ketones or aromatic solvents. Suitable ethers include glycolalkyl ethers .. . :
: '~` ~
such as propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether and diethylene glycol butyl ether. These ethers are colorless liquids which combine the properties of alcohols, ethers and hydrocarbons. They are miscible with most organic solvents and they are excellent solvents for mixing with the phosphor and barium titanate components of electroluminescent devices.
Suitable alkyl ketones and aromatic solvents which can also be employed as solvents include lower alkyl ketones such as acetone, methyl ethyl ketone, ethyl ketone and methylisobutyl ketone, toluene, xylene and the like.
In making the barium titanate layer, the barium titanate solid is first admixed with a suitable solvent as described above. The amount of barium titanate which is added to the glycol ether or other solvent is preferably about 70-~0% by weight. The barium titanate and the solvent are stirred together to form a homoqeneous slurry. To this slurry is added from 10 to 30 parts of a binder, including a cyanoalkylated polymer resin as described above which can also be in a like solvent. After mixing thoroughly, the barium titanate-binder-solvent slurry is deposited onto a metal foil or other electrode and dried. Suitably a barium titanate/resin binder layer ~hickness when dried is from about 2-6 mils.
.:
_g_ -"' 2~62278 The phosphor is also first admixed with a suitable sol~ent and mixed well. Suitable phosphors are luminescent unde~r the influence of an electric current, as for example zinc sulfide, zinc oxide or zinc sulfide activated with manganese, copper, copper/lead or copper/manganese mixtures. The amount of phosphor added to the solvent can range suitab'y from about 60-95% by weight of the mixture, and is preferably from about 75-85% by weight. ~he light emitted by the electroluminescent cell is at least partially dependent upon the particle size and concentration of phosphor in the cyanoalkylated polymer. The maximum amount of phosphor is added consistent with there being sufficient amount of binder present to encapsulate the phosphor to protect it from moisture. After mixing well, from 5 to 40 parts of a binder is also added to the phosphor slurry. The resultant phosphor slurry is deposited onto a transparent electrode in known manner. A suitable phosphor/binder layer ; thickness when dried is from about 2-6 mils.
The phosphor-containing and barium titanate-containing ; slurries can be deposited onto their respective electrodes by spray coating, roller coating, painting or hot presssing techniques known in the art. The thickness of the deposited layers may be varied to provide optimum light emitting effects.
The electrodes of the present electroluminescent devices ~; include a transparent electrode, which can be of transparent plastic film or sheet such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, ::`
` ~. .
~: :
, , polymethylmethacrylate and the liXe, or of glass. The transparent film or glass is coated with a transparent conductive film, such as an indium-tin oxide film, as is known.
The other electrode is of a conductive metal, such as aluminum, gold, silver, copper, in a variety of thicknesses, from a thick sheet to a thin foil.
The two parts of the electroluminescent cell as described above, i.e., the barium titanate/binder layer on a metal electrode and the phosphor/binder layer on a transparent electrode, are assembled by hot pressing at temperatures in the range of about 150-400F at a pressure of from about S-lO0 psi for a period of about 0.1-2.0 seconds. Electrical leads or connections are made to the electrodes and then connected to a source of electrical current. When an electrical current is passed across the electrodes, the phosphor particles are activated and light is emitted from the cell. In accordance with the invention, at least one of the phosphor layers or barium titanate layers contains a cyanoalkylated pullulan resin or resin mixture as the binder.
The assembled electroluminescent device lO is shown in Fig. 1 wherein a barium titanate/binder layer 14 is deposited onto an aluminum foil 12 and a phosphor/binder layer 16 is deposited onto an indium-tin oxide coated polymer film 18.
Leads 20 complete the device lO.
The electroluminescent devices of the invention, having at least one o~ the phosphor/binder and barium titanate/binder .
.
: ~ -2o6~278 layers containing as a binder a cyanoalkylated pullulan resin or mixture thereof, unexpectedly have high intensity light emission, much higher than that of conventional electroluminescent devices. The presence of the high dielectric constant cyanoethylated pullulan polymers and mixtures in the present devices increases the brightness achievable with these devices. Increased brightness is achieved with the binders of the invention providing pullulan polymer is added to one or more of the layers of the electroluminescent device even when conventional binders, such as epoxy resins, are used as a binder in one of the layers of the electroluminescent device, or as a portion of the binder in either layer. This result was highly unexpected. Further, these resins are able to be used in commercial coating and lamination processes without modification, and provide adequate adhesion to both the phosphor and barium titanate components.
The invention will be further illustrated by the following examples, but the invention is not meant to be limited to the details described therein. In the Examples, parts and percentages are by weight.
,' ' ' ' .
206~27~
Pullulan-Phosphor Modified Lamp A mixture was made from 10.24 grams of a binder comprised of a mixture of cyanoethyl pullulan resin and cyanoethylpolyvinyl alcohol available as Cyepl 02 from Shin Etsu of Japan. This resin as a 20% solution in dimethylformamide had a viscosity of 240-260 centipoises; a nitrogen content of between 12.2 and 13.5: a specific gravity of 1.27 and a softening temperature of 20-40C. The binder was mixed in a 50:50 weight ratio of about one part binder to two parts of solvent. To this mixture was added 43.64 grams of zinc sulfide phosphor containing a copper activator.
The resultant slurry was cast onto a series of polyethylene terephthalate tapes having an indium/tin oxide conductive layer thereon in varying thickness.
A control series of tapes was made using a standard phosphor slurry containing the resin D.E.R. 684-EK40, as described in U.S. Patent 4,560,902 to Xardon. D.E.R.-EK40 is an ultra high molecular weight epoxy resin derived from the reaction of bisphenol A and epichlorohydrin, and is a registered trademark of the Dow Chemical Company, Midland, Michigan.
Both series of tapes were dried and laminated to an aluminum foil having a layer of barium titanate in standard epoxy binder thereon. The layers were passed several times through a heat sealing laminator and brightness measured in foot-lamberts at 120 Volts, 400 Hz. The data are summarized in Table I below:
Film __ Brightness, foot-lamberts Thickness mils Pass 1Pass 2 Pass 3 Pass 4 Pass 5 Control 1.45 7.~ 7.58.5 8.89.6 9.6 10.3 10.1 10.3 10.1 1.60 9.4 9.410.4 10.411.3 11.5 11.9 12.2 12.0 11.0 1.90 9.6 9.710.4 10.511.0 10.5 2.25 8.9 9.69.7 10.0 Example 1 1.65 11.3 12.9 13.1 14.4 15.1 16.~ 16.2 16.2 17.9 17.2 2.00 12.9 11.7 13.9 15.2 15.7 16.9 16.9 17.6 17.9 18.3 2.35 14.4 15.4 16.3 16.5 16.7 16.9 2.75 14.8 14.9 ! 3.10 12.7 13.2 14.2 14.9 14.6 15.2 14.6 13.8 Thus it is apparent that when the resin of the invention was mixed with the phosphor layer alone, the brightness of the electroluminescent cells improved significantly.
Pullulan-Barium Titanate Modified Lamp Barium titanate (18.84 grams) was admixed with the cyanoethyl pullulan/cyanoethylpoly~inyl alcohol binder of Example 1 (31.0fi grams) in 15 grams of a 50:50 blend of acetone and methyl ethyl ketone solvent. The resultant slurry was deposited onto aluminum foil at varying thickness, dried and laminated to a conventional phosphor coating 4 mils thick using an epoxy binder on an indium/tin oxide polyethylene tape.
., .
. ' .
.. ~, : .
.' - . ' ' .
` 2062278 The electroluminescent cells were passed through the laminator three times, and the brightness measured after each pass as in Example 1. The results are tabulated below in Table II.
TABLE II
Layer Brightness. foot-lamberts Thickness, ; mils Pass I Pass 2 Pass 3 2 15.5 16.2 15.9 16.6 18.0 17.2 3 17.4 17.5 19.4 18.8 19.8 18.8 4 19.0 18.7 21.7 20.2 21.8 20.3 18.8 18.0 20.7 19.5 20.8 19.7 6 17.9 17.9 20.0 20.5 20.3 20.8 It is apparent that improved brightness is obtained when the cyanoalkylated pullulan binder of the invention is present in the barium titanate layer alone as well.
; 20 Pullulan-Phos~hor and Pullulan-Barium Titanate Modified Lamp The binder employed in Examples 1 and 2 was used to make both the phosphor layers and the barium titanate layers of electroluminescent cells. In the first group of cells, the layer thickness of the barium titanate layer was varied and the ; 25 phosphor layer was maintained at 4 mils; in the second group of cells, the barium titanate was maintained at 5 mils and the phosphor layer thickness was varied. The cells were passed through a laminating process three times and the brightness measured after each pass as in Example 1. The results are summarized in Table III below.
.
.
- . , ~ `
.
,: . . : . . .
2~62~78 TABLE III
Layer Brightness. foot-lamberts Thickness.
Mils Pass l Pass 2 Pass 3 Group l 3 2~.4 30.0 29.4 30.0 30.2 29.3 4 30.0 29.6 33.3 32.8 35.8 34.7 31.0 30.5 32.6 34.0 34.0 35.4 6 30.8 30.6 32.2 32.7 34.8 34.9 Group 2 2 30.7 31.4 34.8 34.5 38.2 37.5 3 34.1 33.4 35.6 35.2 36.1 35.4 4 31.4 32.0 32.1 33.9 35.7 34.1 31.3 31.7 33.0 33.5 34.6 34.4 It is apparent that the brightness of the above electroluminescent cells is far superior to conventional cells, and the brightness is increased when both the barium titanate and phosphor layers use the binder of the invention.
Several electroluminescent cells were made varying the phosphor and barium titanate layers and the laminating conditions. A phosphor layer of Example l was deposited to a thickness of 2.3 mils, and a control standard phosphor layer using epoxy binder was deposited in a thickness of 1.75 mils.
The barium titanate/binder mixture of Example 2 was deposited onto 1.5 mil thick aluminum foil in a thickness of 1.3 mils, and a control barium titanate/conventional epoxy binder was deposited onto aluminum foil in a thickness of 1.3 mils. Cells A were laminated using a standard phosphor/epoxy resin binder ;~ , ' , ' , ' , ~ ' : . ' and the barium titanate/binder mixture of Example 2; thus the pullulan polymer was present in only one layer, the barium titanate layer. Cells B were laminated using pullulan in both the phosphor/binder and barium titanate/binder layers of Examples 1 and 2. The control used the standard epoxy binder containing phosphor and barium titanate layers. The brightness was measured as in Example 1. The results are summarized in Tables IV and V below.
TABLE IV *
Temperature. Briahtness._foot-lamberts F Control Cells A Cells B
200 11.2 22.0 29.7 240 12.5 24.5 26.8 275 12.4 26.8 39.3 Pressure was constant at 60 lbs.
TABLE V **
Pressure. Brightness. foot-lamberts lbs Control Cells A Cells B
9.5 18.9 27.2 11.1 24.3 26.8 27.2 31.9 39.3 ** Temperature was constant at 175F.
Thus the electroluminescent devices containing pullulan had increased brightness over conventional electroluminescent devices containing binders of conventional epoxy resins.
Electroluminescent devices containing pullulan in both the phosphor layer and the dielectric layer had the greatest briqhtness.
., ~ -17-.
" , .:
-:
An electroluminescent cell was made using 87 grams of lead sulfide phosphor admixed with 15 grams of cyanoalkylated pullulan having a nitrogen content of about 12% and a softening temperature in the range 90-110F in dimethylformamide. The resultant solution at 20C had a viscosity of 240-360 centipoises. The specific gravity of the solution was 1.25.
Propylene glycol methyl ether was used as a solvent.
Layers varying in thickness were applied to a transparent indium/tin oxide on polyethylene terephthalate sheet. The mixture was dried in an oven at 120C.
A layer of barium titanate mixed with cyanoethylated pullulan as above (85 grams of barium titanate per 15 grams of pullulan resin) in propylene glycol methyl ether and deposited - on an aluminum foil and dried in an oven at 120C.
The two layers were compressed together at 150 psi ` pressure at 150C, leads attached, and the cell joined to a source o~ 120 volt AC current. The cells were tested as follows:
~'~
, ., ~.
Thickness. mils Power Foot-Lamberts 1.60 120V,400Hz 30.0 140V,600Hz 44.5 1."5 120V,400Hz 29.6 75V,600Hz 22.7 1.35 120V,400Hz 33.0 75V,600Hz 20.9 1.05 120V,400Hz 30.9 75V,600Hz 21.9 0.80 120V,400Hz 23.1 75Y,600Hz 20.5 The above electroluminescent devices all had excellent brightness. Thus the addition of pullulan polymers and polymer mixtures unexpectedly improves the brightness of electroluminescent devices.
This invention has been described by reference to precise embodiments but it will be appreciated by those skilled in the art that this invention is subject to various modifications and to the extent that those modifications would be obvious to one of ordinary skill they are considered as being within the scope of the appended claims.
:: .
Claims (34)
1. In an electroluminescent device comprised of a phosphor layer and a dielectric layer disposed between two electrodes, one of which is transparent, the improvement which comprises incorporating into at least one of said layers as a binding agent a pullulan selected from among cyanoalkylated pullulan polymers or a mixture of cyanoalkylated polymers.
2. The device according to claim 1 wherein said polymer is a compound of the formula wherein X is hydrogen or cyanoloweralkyl and n is an integer having a value of from about 20-4000.
3. The device according to claim 1 wherein said polymer has a nitrogen content of from about 4-20% by weight.
4. The device according to claim 2 wherein the degree of cyanoalkylation in said polymer is at least about 50%.
5. The device according to claim 1 wherein said cyanoalkylated pullulan is admixed with a cyanoalkylated polymer of the group consisting of cyanoalkylcellulose, cyanoalkylpolyvinyl alcohol, cyanoalkylsucrose, cyanoalkylhydroxy cellulose and cyanoalkylated epoxy resin.
6. The device according to claim 5 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylpolyvinyl alcohol having a nitrogen content of about 12.2-13.5% by weight and a softening temperature of from 20-40°C.
7. The device according to claim 5 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylcellulose having a nitrogen content of about 11.8-13.0% by weight and a softening temperature greater than 270°C.
8. The device according to claim 5 wherein said mixture is a liquid comprised of cyanoalkylated pullulan and cyanoalkylsucrose having a nitrogen content of about 14% by weight.
9. The device according to claim 5 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylhydroxy cellulose having a nitrogen content of about 9.0-10.9% by weight and a softening temperature of about 55-65°C.
10. The device according to claim 5 wherein said mixture comprises cyanoalkylated pullulan and a cyanoalkylated epoxy resin of the formula wherein R and R' are the same or different members selected from the group consisting of hydrogen, lower alkyl and mononuclear aryl; R" is hydrogen or cyanoloweralkyl; X and X' are the same or different members selected from the group consisting of hydrogen, lower alkyl and halogen; and m is an integer greater than 1.
11. The device according to claim 2 wherein said cyanoloweralkyl is cyanoethyl.
12. The device according to claim 1 wherein said pullulan is incorporated into said phosphor layer.
13. The device according to claim 1 wherein said pullulan is incorporated into said dielectric layer.
14. The device according to claim 13 wherein said dielectric layer is barium titanate.
15. The device according to claim 1 wherein said pullulan is incorporated into said phosphor layer and said dielectric layer.
16. An electroluminescent device comprising a transparent electrode having a layer of a phosphor and a cyanoalkylated polymer of pullulan or polymer mixtures thereof thereon, an adjacent layer containing a dielectric and a cyanoalkylated polymer of pullulan or polymer mixtures thereof thereon, and a metal electrode contacting said dielectric layer.
17. The device according to claim 16 wherein said mixture comprises cyanoalkylated pullulan and a cyanoalkylated epoxy resin of the formula wherein R and R' are the same or different members selected from the group consisting of hydrogen, lower alkyl and mononuclear aryl; R" is hydrogen or cyanoloweralkyl; X and X' are the same or different members selected from the group consisting of hydrogen, lower alkyl and halogen; and m is an integer greater than 1.
18. The device according to claim 16 wherein said cyanoalkylated pullulan has a nitrogen content of about 4-20%
by weight and a softening point of from about 20°C.
by weight and a softening point of from about 20°C.
19. The device according to claim 16 wherein said cyanoalkyl is cyanoethyl.
20. The device according to claim 16 wherein said dielectric layer is barium titanate.
21. The device according to claim 16 wherein said cyanoalkylated pullulan is admixed with a cyanoalkylated polymer of the group consisting of cyanoalkylcellulose, cyanoalkylpolyvinyl alcohol, cyanoalkylsucrose, cyanoalkylhydroxy cellulose and cyanoalkylated epoxy resin.
22. The device according to claim 21 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylpolyvinyl alcohol having a nitrogen content of about 12.2-13.5% by weight and a softening temperature of from 20-40°C.
23. The device according to claim 21 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylcellulose having a nitrogen content of about 11.8-13.0% by weight and a softening temperature greater than 270°C.
24. The device according to claim 21 wherein said mixture is a liquid comprised of cyanoalkylated pullulan and cyanoalkylsucrose having a nitrogen content of about 14% by weight.
25. The device according to claim 21 wherein said mixture comprises cyanoalkylated pullulan and cyanoalkylhydroxy cellulose having a nitrogen content of about 9.0-10.9% by weight and a softening temperature of about 55-65°C.
26. A composition useful as a binder in an electroluminexcent device comprising a phosphor/binder layer and a dielectric/binder layer which comprises a cyanoalkylated pullulan polymer or a mixture of cyanoalkylated polymers.
27. A composition according to claim 26 wherein said cyanoalkylated pullulan has the formula wherein X is hydrogen or cyanoloweralkyl and n is an integer having a value of from about 20-4000.
28. A composition according to claim 26 wherein said cyanoalkylated pullulan is admixed with a member selected from the group consisting of cyanoalkylcellulose, cyanoalkylpolyvinyl alcohol, cyanoalkylsucrose, cyanoalkylhydroxycellulose and cyanoalkylated epoxy resin.
29. A composition according to claim 28 wherein said cyanoalkylpolyvinyl alcohol has a nitrogen content of about 12.2-13.5% by weight and a softening temperature of from 20-40°C.
30. A composition according to claim 28 wherein said cyanoalkylcellulose/cyanoalkylpullulan mixture has a nitrogen content of from about 11.8-13.0% by weight and has a softening point over 270°C.
31. A composition according to claim 28 wherein said cyanopolyalkylsucrose/cyanoalkylpullulan mixture is a liquid and has a nitrogen content of about 14% by weight.
32. A composition according to claim 28 wherein said cyanoalkylhydroxycellulose/cyanoalkylpullulan mixture has a nitrogen content of from about 9.0-10.9% by weight and has a softening temperature of about 55-65°C.
33. A composition according to claim 28 wherein the epoxy resin of said cyanoalkylated epoxy/cyanoalkylpullulan mixture has the formula wherein R and R' are the same or different members selected from the group consisting of hydrogen, lower alkyl and mononuclear aryl; R" is hydrogen or cyanoloweralkyl; X and X' are the same or different members selected from the group consisting of hydrogen, lower alkyl and halogen; and m is an integer greater than 1.
34. The composition according to claim 26 wherein said cyanoloweralkyl is cyanoethyl.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US66482491A | 1991-03-05 | 1991-03-05 | |
US664,824 | 1991-03-05 |
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CA2062278A1 true CA2062278A1 (en) | 1992-09-06 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CA002062278A Abandoned CA2062278A1 (en) | 1991-03-05 | 1992-03-04 | Electroluminescent device |
Country Status (8)
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JP (1) | JPH06145656A (en) |
KR (1) | KR920018194A (en) |
CA (1) | CA2062278A1 (en) |
DE (1) | DE4206668A1 (en) |
FR (1) | FR2673802A1 (en) |
GB (1) | GB2257828A (en) |
IT (1) | IT1256536B (en) |
TW (1) | TW199258B (en) |
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JP2001177145A (en) * | 1999-12-21 | 2001-06-29 | Toshiba Electronic Engineering Corp | Semiconductor light emitting device and method of manufacturing the same |
KR20010067851A (en) * | 2001-04-03 | 2001-07-13 | 정동은 | An electro luminescence lamp of the sheet type |
US20060255718A1 (en) * | 2004-08-30 | 2006-11-16 | Fuji Photo Film Co., Ltd. | Dispersion type electroluminescent element |
AT12550U1 (en) * | 2010-08-06 | 2012-07-15 | Robert Dipl Ing Hofer | LIGHT BODY AND METHOD FOR THE PRODUCTION THEREOF |
TWI666968B (en) * | 2016-01-22 | 2019-07-21 | 亨亮光電科技股份有限公司 | Electroluminescent structure and manufacturing method thereof |
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US3213341A (en) * | 1961-11-24 | 1965-10-19 | American Cyanamid Co | Polymers suitable for use in electroluminescent lamps and capacitors |
NL6505557A (en) * | 1964-05-02 | 1965-11-03 | ||
US3342848A (en) * | 1965-02-11 | 1967-09-19 | Gen Electric | N, n'-dialkyl-n, n'-dicyanoalkyl-o-phthalamides |
US4438262A (en) * | 1981-10-06 | 1984-03-20 | Sumitomo Chemical Company, Limited | Highly dielectric polysaccharides |
JPH086087B2 (en) * | 1988-02-09 | 1996-01-24 | 信越化学工業株式会社 | EL device |
JPH02223192A (en) * | 1989-02-23 | 1990-09-05 | Hitachi Maxell Ltd | Dispersion-type el device and its manufacture |
JPH0810631B2 (en) * | 1989-05-23 | 1996-01-31 | 信越化学工業株式会社 | Dielectric composition and dispersed electroluminescent device |
JPH07119406B2 (en) * | 1989-07-04 | 1995-12-20 | 日亜化学工業株式会社 | EL lamp |
-
1992
- 1992-03-03 DE DE4206668A patent/DE4206668A1/en not_active Withdrawn
- 1992-03-04 FR FR9202614A patent/FR2673802A1/en active Pending
- 1992-03-04 TW TW081101658A patent/TW199258B/zh active
- 1992-03-04 GB GB9204705A patent/GB2257828A/en not_active Withdrawn
- 1992-03-04 CA CA002062278A patent/CA2062278A1/en not_active Abandoned
- 1992-03-05 JP JP4083416A patent/JPH06145656A/en active Pending
- 1992-03-05 IT ITTO920183A patent/IT1256536B/en active IP Right Grant
- 1992-03-05 KR KR1019920003629A patent/KR920018194A/en not_active Application Discontinuation
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GB9204705D0 (en) | 1992-04-15 |
FR2673802A1 (en) | 1992-09-11 |
ITTO920183A1 (en) | 1993-09-05 |
IT1256536B (en) | 1995-12-07 |
GB2257828A (en) | 1993-01-20 |
DE4206668A1 (en) | 1992-09-10 |
TW199258B (en) | 1993-02-01 |
ITTO920183A0 (en) | 1992-03-05 |
KR920018194A (en) | 1992-10-21 |
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