USOO9023240B2 (12) United States Patent (10) Patent No.: US 9,023,240 B2 Fujinaga et al. (45) Date of Patent: *May 5, 2015 (54) SILICON NITRIDE POWDER FOR 11/7761; C09K11/7774; C09K11/7792; SILICONNITRIDE PHOSPHOR, CAALSIN, C01P 2004/03: C01P 2004/61; C01P 2004/06; PHOSPHORUSING SAME, SRSIN C01P 2006/80; C01P 2002/54; C01P 2004/52; PHOSPHORUSING SAME, (SR, CA)ALSIN, C01P 2006/12: C04B 35/584: CO4B PHOSPHORUSING SAME, LASIN 2235/3878; C04B 2235/5409; C04B PHOSPHORUSING SAME, AND METHODS 223.5/5436; C04B 2235/723; H01L 23/15; FOR PRODUCING THE PHOSPHORS H01L 23/3731; H01L 33/504; C01B 21/0602; C01B 21/068; Y02B 20/181 (75) Inventors: Masataka Fujinaga, Yamaguchi (JP); USPC ....... 252/301.4 F, 301.4 R, 301.6 F; 428/325, Takayuki Ueda, Yamaguchi (JP); 428/402, 698,704 Takuma Sakai, Yamaguchi (JP); See application file for complete search history. Shinsuke Jida, Yamaguchi (JP) (56) References Cited (73) Assignee: UBE Industries, Ltd. (JP) U.S. PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 6,682,663 B2 1/2004 Botty et al. 8, 147,715 B2 * 4/2012 Hirosaki ................. 252/301.4 F U.S.C. 154(b) by 0 days. 2002/0164475 A1* 11/2002 Imamura et al. ... 428/325 2005/0094381 A1* 5/2005 Imamura et al. .............. 361/750 This patent is Subject to a terminal dis 2006/0033083 A1 2/2006 Sakane et al. ........... 252/301.4F claimer. 2009/0134775 A1* 5, 2009 Watanabe et al. ............. 313,503 2009, O250663 A1* 10, 2009 Oshio .................... 252/3014 R (21) Appl. No.: 13/813,596 2010.0085728 A1* 4/2010 Seto et al. ....................... 362/84 2011/O121234 A1* 5, 2011 Hirosaki .... 252/301.4 F (22) PCT Filed: Jul. 29, 2011 2011/0272187 A1* 1 1/2011 Kaga et al. .................... 174,260 2012/0305958 A1* 12/2012 Seibel et al. .................... 257/98 (86). PCT No.: PCT/UP2011/067467 FOREIGN PATENT DOCUMENTS S371 (c)(1), (2), (4) Date: Feb. 25, 2013 CN 1839.192 A 9, 2006 CN 10.1090953. A 12/2007 (87) PCT Pub. No.: WO2012/017949 (Continued) PCT Pub. Date: Feb. 9, 2012 OTHER PUBLICATIONS (65) Prior Publication Data Hoppe, H.A., et al. “Luminescence in EU2+-doped Ba2Si3N8: fluo US 2013/O140490 A1 Jun. 6, 2013 rescence, thermoluminescence, and upconversion'. Journal of Phys ics and Chemistry of Solids, 2000, vol. 61, pp. 2001-2006. (30) Foreign Application Priority Data Van Krevel, J.W.H., "On new rare-earth doped M. Si–Al-O N materials Luminescence properties and oxidation resistance'. TU Aug. 4, 2010 (JP) ................................. 2010-175724 Eindhoven, 2000, ISBN 90-386-2711-4, pp. 29-40. Aug. 30, 2010 (JP) ................................. 2010-1921.92 Hirosaki, Naoto et al., “Synthesis and Crystal Structure of Red Nitride Phosphor, CaAlSiN3:Eu2+”. The 65th Meeting of The Japan Aug. 30, 2010 (JP) ................................. 2010-192209 Society of Applied Physics, Lecture notes, 2004, p. 1283. Aug. 30, 2010 (JP) ................................. 2010-192252 English translation of the International Preliminary Report on Pat entability which issued in connection with corresponding Interna (51) Int. Cl. tional Application No. PCT/JP2011/067467. C09K II/08 (2006.01) C09K II/77 (2006.01) COIB 2/068 (2006.01) Primary Examiner — Carol M Koslow COIB 2/06 (2006.01) Assistant Examiner — Lynne Edmondson (52) U.S. Cl. (74) Attorney, Agent, or Firm — Clark Hill PLC CPC ......... COIB 21/068 (2013.01); Y10T 428/2982 (2015.01); COIB 21/0602 (2013.01); COIP (57) ABSTRACT 2002/54 (2013.01); COIP 2004/03 (2013.01); COIP 2004/61 (2013.01); COIP 2006/12 Provided are a crystalline silicon nitride powder for a silic (2013.01); COIP 2006/80 (2013.01); C09K onitride phosphors, which is used as a starting material for II/0883 (2013.01); C09K II/7734 (2013.01); producing a siliconitride phosphor containing a silicon ele C09K II/7774 (2013.01); C09K II/7792 ment and a nitrogen element but no oxygen element as a (2013.01); COIP 2004/62 (2013.01) constitutent element, an oxygen content of the silicon nitride (58) Field of Classification Search phosphor being 0.2-0.8 wt %; a CaAlSiN. phosphor, an CPC ............. C09K11/083; C09K11/0883; C09K Sr-SisNs phosphor, an (Sr, Ca)AlSiN phosphor and an 1 1/643; C09K11/7703: C09K11/7706; LaSiN phosphor, each using the silicon nitride powder; C09K11/7715; C09K11/7718; C09K and a method for producing the phosphors. 11/7721; C09K11/7728; C09K11/7734; C09K11/7746; C09K11/7749; C09K 6 Claims, 1 Drawing Sheet US 9,023,240 B2 Page 2 (56) References Cited JP 2003-112977 4/2003 JP 3837588 1, 2006 JP 2007-291352 11, 2007 FOREIGN PATENT DOCUMENTS JP 2008-088362 4/2008 JP 2009-218422 9, 2009 CN 1.01171321 A 4/2008 JP 2010-070773 4/2010 CN 1.01434839. A 5, 2009 WO 2006/080535 8, 2006 JP 09-040406 2, 1997 WO WO 2007066733 A1 * 6, 2007 JP 2000-208815 T 2000 JP 2002-097005 4/2002 * cited by examiner U.S. Patent May 5, 2015 US 9,023,240 B2 FG. US 9,023,240 B2 1. 2 SILICON NITRIDE POWDER FOR various values) as a mother skeleton, or Patent Literature 3, SILICONNITRIDE PHOSPHOR, CAALSIN, i.e., a phosphor having M.Si.N.:Eu (M-Ca,Sr, Ba, Zn; Z–2/ PHOSPHORUSING SAME, SRSIN, 3x+4/3y) as a mother skeleton is known. However, with exci PHOSPHORUSING SAME, (SR, CA)ALSIN, tation by blue-color visible light, the red light emission inten PHOSPHORUSING SAME, LASIN sity remains insufficient. PHOSPHORUSING SAME, AND METHODS Recently, a white-light emitting diode having near ultra FOR PRODUCING THE PHOSPHORS violet to blue-light emitting diode as an excitation source is actively studied. Thus, a phosphor emitting strong yellow RELATED/PRIORITY APPLICATION light in response to Such excitation wavelength is waited for. 10 As a yellow-color luminescent material, YAl30:Ce has This application is a National Phase filing regarding inter been conventionally used. However, as disclosed in Patent national Application No. PCR/JP2011/067467, filed on Jul. Literature 4, LaSiN is also known. 29, 2011, which relies upon Japanese Application No. Accordingly, those nitride phosphors can be used for a JP2010-175724, filed on Aug. 4, 2010, Japanese Patent vacuum fluorescent display (VFD), a field emission display Application No. 2010-192252, filed on Aug. 30, 2010, Japa 15 (FED), a plasma display panel (PDP), a cathode ray tube nese Patent Application No. 2010-192209, filed on Aug. 30. (CRT), a white-light emitting diode (LED), or the like, and 2010, and Japanese Patent Application No. 2010492192, filed their use as a phosphor having low luminance degradation is on Aug. 30, 2010, for priority. expected. TECHNICAL FIELD CITATION LIST The present invention relates to a silicon nitride powder for Patent Literatures a siliconitride phosphor having higher fluorescent intensity which is used for a display, a back light of liquid crystal, a Patent Literature 1: JP 2000-208815 A fluorescent lamp, a white-light emitting diode, or the like, a 25 Patent Literature 2: JP 3837588 B1 CaAlSiN. phosphor, a Sr. SiN. phosphor, a (Sr, Ca)AlSiN Patent Literature 3: U.S. Pat. No. 6,682,663 phosphor, and a LaSiN phosphor, each using the silicon Patent Literature 4: JP 2010-70773 A nitride powder, and methods for producing the phosphors. Non-Patent Literatures BACKGROUND ART 30 Non-Patent Literature 1: Journal of Physics and Chemistry of Recently, in response to realized application of a blue-light Solids, Vol. 61 (2000) pages 2001 to 2006 emitting diode, a white-light emitting diode having this diode Non-Patent Literature 2: The 65th Meeting of The Japan as a light source is actively studied. Since the white-light Society of Applied Physics, Lecture notes, page 1283. emitting diode is lightweight, does not use mercury, and has 35 Non-Patent Literature 3: “On new rare-earth doped M-Si long lifetime, a rapidly rising demand is expected for it in Al-O N materials”, written by J. W. H. van Krevel, TU future. In general, as a white-light emitting diode, those Eindhoven 2000, ISBN 90-386-2711-4 obtained by coating paste of a mixture containing YAG (YA10:Ce) powder activated by cerium and epoxy resin SUMMARY OF INVENTION on a blue-light emitting device are used (Patent Literature 1). 40 However, as the fluorescent color of YAG:Ce is present Technical Problem near x=0.41, y=0.56 of CIE color coordinates, when admixed with excitation light with blue color of 460 nm, the color is Since the fluorescent intensity of those nitride phosphors is controlled on a line which connects the color coordinates of not sufficient yet, development of a phosphor having higher the blue-light emitting diode and the color coordinates of 45 luminance is in need. In this regard, an object of the present YAG, and as a result, white color mixed with greenish blue invention is to provide a silicon nitride powder for siliconi color is obtained instead of white color. For such reasons, a tride phosphor having high luminance, which can be used for problem arises in that only white color with insufficient red a vacuum fluorescent display (VFD), a field emission display color can be achieved. To deal with such poor color problem, (FED), a plasma display panel (PDP), a cathode ray tube YAG:Ce phosphor powder is admixed with a separate phos 50 (CRT), a light emitting diode (LED), or the like, a CaAlSiN phor powder exhibiting red color for color control. phosphor, a Sr-SisNs phosphor, a (Sr, Ca)AlSiN.