Abstract: Disclosed is a process for producing a polymer of an unsaturated carboxylic acid or a derivative thereof, the process comprising polymerizing an unsaturated carboxylic acid or a derivative thereof in a water-soluble organic solvent-water mixture in the presence of at least one polymerization catalyst selected from the group consisting of a metal compound of the formulaL.sub.p.M.X.sub.q ( 1)wherein M is Ti, Zr, Hf or V, L is cyclopentazienyl, indenyl, fluorenyl or a derivative of these, X is halo, H, lower alkyl, lower alkoxyl, aryloxy, phenyl or benzyl, p and q each represents an integer including 0 and p+q is equal to the valence of M, and a metal compound of the formulaR.M.Y.sub.r ( 2)wherein M is defined above, R is a group formed by bonding, via a lower alkylene or di(lower alkyl)silylene group, two groups being cyclopentadienyl, indenyl, fluorenyl or a derivative of these, Y is halo, H, lower alkyl, lower alkoxyl, aryloxy, phenyl or benzyl, r is equal to the valence number of M minus 2.
Type:
Grant
Filed:
April 26, 1995
Date of Patent:
May 6, 1997
Assignees:
Sumitomo Chemical Co., Ltd., Nichia Chemical Industries Ltd.
Abstract: A light-emitting gallium nitride-based compound semiconductor device of a double-heterostructure. The double-heterostructure includes a light-emitting layer formed of a low-resistivity In.sub.x Ga.sub.1-x N (0<x<1) compound semiconductor doped with p-type and/or n-type impurity. A first clad layer is joined to one surface of the light-emitting layer and formed of an n-type gallium nitride-based compound semiconductor having a composition different from the light-emitting layer. A second clad layer is joined to another surface of the light-emitting layer and formed of a low-resistivity, p-type gallium nitride-based compound semiconductor having a composition different from the light-emitting layer.
Abstract: A gallium nitride-based III-V Group compound semiconductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.
Type:
Grant
Filed:
April 28, 1994
Date of Patent:
October 8, 1996
Assignee:
Nichia Chemical Industries, Ltd.
Inventors:
Shuji Nakamura, Takao Yamada, Masayuki Senoh, Motokazu Yamada, Kanji Bando
Abstract: A method for manufacturing a III-V Group compound or a II-VI Group compound semiconductor element by VPE, comprising the step of annealing a grown compound at 400.degree. C. or higher, or irradiating electron beam the grown compound at 600.degree. C. or higher.
Abstract: An IR-to-visible converter for a solid-state image converting device including a photoconductive layer and an electroluminescent layer is sensitive to 1.5 .mu.m region IR rays and can convert such IR rays with high efficiency into visible light perceivable even in a well-lighted room. The IR-to-visible converter is characterized by using an IR to visible upconversion phosphors layer which has emission peaks in the sensitive wavelength region of the photoconductor layer, the IR to visible upconversion phosphors layer being optically combined with photoconductive layer.
Type:
Grant
Filed:
May 3, 1994
Date of Patent:
August 1, 1995
Assignee:
Nichia Chemical Industries, Ltd.
Inventors:
Masuyuki Ebitani, Toshifumi Tominaga, Akihito Kishi
Abstract: Electrolytes are attached to fluorescent particle surfaces to prevent open spots in cathode-ray tube coatings dried at high temperatures. Electrolytes that are sulfates, nitrates, or chlorides of alkali or alkaline-earth metals are added to a liquid suspension of fluorescent particles which have passed through a cleaning step. Electrolytes are added to the suspension to make the conductivity of the clear top liquid greater than 30 .mu..OMEGA..sup.-1 cm.sup.-1. The fluorescent particle preparation process is finished with a final dehydration and drying step.
Abstract: A method of depositing a gallium nitride-based III-V Group compound semiconductor crystal layer over a substrate by a metalorganic chemical vapor deposition technique. A reaction gas is supplied to a surface of a heated substrate in a direction parallel or oblique to the substrate. The gallium nitride-based III-V Group compound semiconductor crystal layer is grown on the heated substrate, while introducing a pressing gas substantially in a vertical direction toward the substrate to press the reaction gas against the entire surface of the substrate, under atmospheric pressure or a higher pressure.
Abstract: Long decay phosphors are disclosed that are comprised of rare-earth activated divalent, boron-substituted aluminates. In particular, the long decay phosphors are comprised ofMO.a(Al.sub.1-b B.sub.b).sub.2 O.sub.3 :cR,wherein0.5.ltoreq.a.ltoreq.10.0,0.0001.ltoreq.b.ltoreq.0.5 and0.0001.ltoreq.c.ltoreq.0.2,MO represents at least one divalent metal oxide selected from the group consisting of MgO, CaO, SrO and ZnO and R represents Eu and at least one additional rare earth element. Preferably, R represents Eu and at least one additional rare earth element selected from the group consisting of Pt, Nd, Dy and Tm.
Type:
Grant
Filed:
January 10, 1994
Date of Patent:
December 27, 1994
Assignee:
Nichia Chemical Industries, Ltd.
Inventors:
Martin R. Royce, Hiroto Tamaki, Yoshinori Murazaki
Abstract: A red-emitting phosphor represented by a general formula (Y.sub.1-x-y Cr.sub.x Gd.sub.y).sub.3 (Al.sub.1-z Ga.sub.z).sub.5 O.sub.12 with the provide that 0.0005.ltoreq.x.ltoreq.0.05, O.ltoreq.y.ltoreq.1, O.ltoreq.z.ltoreq.1, providing red- and infrared emitting luminescence, using alone or in a mixture with other phosphors in a cathode ray tube, having a constant main emission peak even if excited by a high current density, having a satisfactory luminescence efficiency, and causing less brightness saturation in proportion as a current density increases.
Abstract: A cathode-ray tube phosphor is manufactured by coating, on the surfaces of phosphor particles, a mixture of a metal alginate containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one type of a water-soluble binder selected from the group consisting of gum arabic, gelatin, polymethacrylamide, and polyvinyl alcohol.
Type:
Grant
Filed:
December 17, 1992
Date of Patent:
August 9, 1994
Assignee:
Nichia Chemical Industries, Ltd.
Inventors:
Miyuki Sumitomo, Ichiro Takeoka, Shoichi Bando
Abstract: Phosphors capable of emitting substantially white luminescent were represented by the following general formulae, (I), (II) and (III).(Y.sub.1-X-Y-Z Lu.sub.X Tb.sub.Y Sm.sub.Z).sub.2 O.sub.2 S (I)0<X.ltoreq.5.times.10.sup.-21.times.10.sup.-3 .ltoreq.Y.ltoreq.t.times.10.sup.-30.ltoreq.Z.ltoreq.5.times.10.sup.-2(Y.sub.1-a-b-c Yb.sub.a Tb.sub.b Sm.sub.c).sub.2 O.sub.2 S (II)wherein:0<a.ltoreq.5.times.10.sup.-41.times.10.sup.-3 .ltoreq.b.ltoreq.5.times.10.sup.-30.ltoreq.c.ltoreq.5.times.10.sup.-2(Y.sub.1-d-e-f Ce.sub.d Tb.sub.e Sm.sub.f).sub.2 O.sub.2 S (III)wherein 0<d.ltoreq.1.times.10.sup.-4 .times.10.sup.-3 .ltoreq.e.ltoreq.5.times.10.sup.-30.ltoreq.f.ltoreq.5.times.10.sup.
Abstract: A method for manufacturing a III-V Group compound or a II-VI Group compound semiconductor element by VPE, comprising the step of annealing a grown compound at 400.degree. C. or higher, or irradiating electron beam the grown compound at 600.degree. C. or higher.