US2210087A - Process for synthesizing luminescent material - Google Patents
Process for synthesizing luminescent material Download PDFInfo
- Publication number
- US2210087A US2210087A US707866A US70786634A US2210087A US 2210087 A US2210087 A US 2210087A US 707866 A US707866 A US 707866A US 70786634 A US70786634 A US 70786634A US 2210087 A US2210087 A US 2210087A
- Authority
- US
- United States
- Prior art keywords
- manganese
- zinc
- dioxide
- solution
- luminescent material
- 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.)
- Expired - Lifetime
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- 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
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/66—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing germanium, tin or lead
-
- 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
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/59—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing silicon
Definitions
- My invention relates to an improved process for synthesizing luminescent willemite which is particularly adapted for making the fluorescent screens in cathode ray tubes for television reception.
- the material should decay in brilliancy at a very rapid rate, and at least at the rate of one-thirtieth of a second from extreme brilliance to darkness or go black.
- the material should have an invariant spectral distribution. It should resist burning" by high-speed electrons. It should have high secondary-emission efficiency.
- the material should be capable of application to the wall structure of the tube to obtain a uniform and strong screen for observation on the side opposite that which is scanned by the cathode ray. It should begin to fluoresce at a relatively low voltage. It
- luminescent is the emission of light which persists after a time duration of 10- seconds following the excitation of the luminescent materials and in this connection, the theory has postulated that ejected electrons from the material wander in the interstices among the atoms before returning or being recaptured by the atom. Upon its recapture the change in energy between 50 the two levels or electron orbits is indicated by the presence of radiation.
- semi-colon indicates that the phosphor ZnaSi04 is activated by the metal Mn. That is to say that the semi-colon merely indicates that a small amount of the elements following the semig0 colon acts as anactivator and is held in physical bolnd with the material'which precedes thesemico on.
- a solution of a metallic salt such as zinc nitrate
- a metallic salt such as zinc nitrate
- minute particles of a. dioxide such as silicon dioxide are added, sometimes in colloidal solution.
- the metal is then precipitated in the form of an insoluble metal compound to cause some of the metal compound to adhere to the individual particles of the dioxide in the form of a layer or coating about the particles as nuclei or cores to form a homogeneous mixture of the dioxide and the compound.
- the resulting mixture is then washed and dried, and is finally heated to decomposethe insoluble metal compound so that there only remains the homogeneous mixture, each particle of which is substano tially the same and-comprises the metal and the dioxide.
- homogeneous should be qualified as being macroscopically homogenous. That is in any single particle of the mixture the respective constitucuts thereof bear the same relation to each other as the quantity and relative positions in any other particles. Strictly speaking the material is neither heterogeneous nor homogeneous.
- My invention resides in the improved process of the character hereinafter described andclaimed.
- Figure 1 is a '-pictorialillus.- tration of the action whichit is understood takes place in-tlie course of carrying out my improved
- Fig. 2 is an elevational, sectional view, illustrative of one step in a modification of my improved of zinc.
- a satisfactory batch of the luminescent material was obtained by using 45.6 grams of zinc and 0.23 gram of manganese.
- the manganese was used to the extent of being 0.006 gram-mole with respect to one gram-mole zinc.
- the solution was obtained by using 1.5 moles of pure, concentrated nitric acid and 200 cubic centimeters of distilled water. This formed 220 to 230 grams of nitrates of zinc and manganese, in solution.
- any other suitable metals such as magnesium, calcium, beryllium, or any other suitable metal in the first three groups of the periodic system and to use, especially, the alkaline-earth metals in group 2 of this system.
- Second step Finely divided, purified silicon dioxide (silica) is added.
- the particles of silicon dioxide are very small, preferably less than 100 microns in diameter. These particles may be obtained, for example, by grinding in a ball mill, or the like, and then passing the material through a 400 mesh screen. It is proposed to add the silicon dioxide in about 0.45 to 0.6 gram-molecular ratio to the zinc, and touse about a 5% to excess of the silicon dioxide. In the particular operation referred to, the silicon dioxide was added in about a 0.5 gram-molecular ratio to the zinc. The combination is mixed well.
- germanium dioxide instead of the silicon dioxide.
- the minute silicon dioxide particles serve as nuclei about which the zinc and manganese carbonates agglomerate. That is, it is understood that each silicon dioxide particle serves as a core to which there adheres at least one layer or coating of precipitated carbonates of zinc and manganese. This is represented at the left, in Fig. 1
- the dried material is then heated in a refractory crucible at a temperature from 900 degrees to 1400 degrees centigrade and for a period from 5 to 150 minutes, depending upon the amount of the material and the characteristics of the heating furnace, as will be well understood.
- the zinc and manganese are precipitated as sulphides, it is proposed to carry out this heating in an atmosphere containing oxygen. This decomposes the sulphides and removes the sulphur as sulphur dioxide.
- CO2 is driven 011 during the final heating step, it might very naturally be inferred that the resulting compound would be a mixture of zinc and manganese silicates. Such is apparently not the case, since the final material seems to be a zinc orthosilicate wherein manganese is entrained as an activator.
- the formula, ZnzSiOgMn therefore,
- germanium dioxide is used instead of silicon dioxide
- the final result is to obtain a luminescent material known as zinc orthogermanate (ZmGeOuMn).
- ZmGeOuMn zinc orthogermanate
- any one of the other elements in group IV of the periodic table may be used in place of silicon or germanium.
- theefliciency of secondary emission may be increased by adding a small amount of a suitable substance, such as barium, strontium, caesium, cerium, thorium, rubidium, etc.
- a suitable substance such as barium, strontium, caesium, cerium, thorium, rubidium, etc.
- Such a substance can also be added after the carbonates have been formed, such as after the decantation of the last washing water in the fourth step.
- the dioxide may be placed into the nitrate solution of the first step in the form of a piece [0 of the dioxide, as represented in Fig. 2.
- This piece may be in the form of a relatively thin fiat sheet or an irregular piece.
- the precipitating action causes the zinc and manganese carbonates, for example, to be precipitated over the submerged surface of the dioxide material as a layer or coating i 2.
- a cross section of the material would then appear as shown at the left in Fig. 3, with the silicon or germanium dioxide in the center and the outer coating of zinc carbonate and manganese carbonate.
- the sheet or piece of the dioxide material, with the coating of zinc and manganese carbonates is then removed from the nitrate solution and washed and dried, corresponding to the fourth step above.
- Heat is then applied, corresponding to the fifth step above, which causes decomposition of the zinc and manganese carbonates to the oxides of these metals, and penetration in some fashion into the dioxide material to bring about the transition as pictorially illustrated in Fig. 3.
- the result is that there will be a substantial layer of the willemite (ZnzSiOgMn) over a core of the-uncombined dioxide material. The willemite is then scraped off for use.
- the flat screen may be made to form the large end wall of a cathode ray tube, with the screen surface on the inside, facing the electron gun.
- steps in the process of making manganese activated luminescent material which comprise forming salts of zinc and a small amount of manganese in solution, adding to the solution minute particles of silica, precipitating the zinc and manganese out of the solution as insoluble salts to cause crystallization of the insoluble salts about the individual particles of silica, washing and then drying the resulting mass, and heating the dried mass to decompose the insoluble metallic salts to oxides of the metals and to chemically combine the zinc oxide with the silicon with man-' ganese entrained as an activator.
- the process of making luminescent material which comprises obtaining a solution of salts of zinc and manganese, the manganese being used to the extent of from 0.0001 gram-mole to 0.01 gram-mole with respect to one gram-mole of zinc, addition to the solution of minute particles of a dioxide of an element in the fourth group of the periodic. system, precipitation of insoluble salts of the zinc and manganese into adherence with the individual particles of the dioxide, decomposition by heat of the said insoluble salts of zinc and manganese into oxides of these metals and further heating the resultant mass to form with the dioxide macroscopically homogeneous luminescent material.
- the process of making manganese activated luminescent material which comprises formin a solution of a salt of a metal chosen from the first three groups of the periodic system anda small amount of a salt of manganese, adding to the solution minute particles of a dioxide of an element in the fourth group of the periodic system, precipitating the manganese and the metal inthe form of insoluble compounds to cause the same to adhere to the individual particles of the dioxide in the form of a coating about said particles as cores, said insoluble compounds being capable of decomposition by heat into an oxide of manganese and an oxide of the metal, washing and then drying such mixture, heating said mixture to decompose the insoluble compounds into an oxide of manganese and an oxide of the metal, and further heating the resultant mass to chemically combine theoxide of the metal with the dioxide and to entrain the manganese as an activator.
- the process of making a manganese activated luminescent material which comprises the steps of precipitating from a solution a salt of a metal from the first three groups of the periodic system onto the surface of a dioxide of an element in the fourth group of the periodic system and a small amount of a salt of manganese, and then decomposing by heat the precipitated salts into an oxide 'of manganese and an oxide of metal, and heating said oxides to form with the dioxide a macroscopically homogeneous luminescent material activated by manganese.
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- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US707866A US2210087A (en) | 1934-01-23 | 1934-01-23 | Process for synthesizing luminescent material |
DER92411D DE685503C (de) | 1934-01-23 | 1935-01-23 | Herstellung lumineszierender Stoffe |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US707866A US2210087A (en) | 1934-01-23 | 1934-01-23 | Process for synthesizing luminescent material |
Publications (1)
Publication Number | Publication Date |
---|---|
US2210087A true US2210087A (en) | 1940-08-06 |
Family
ID=24843472
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US707866A Expired - Lifetime US2210087A (en) | 1934-01-23 | 1934-01-23 | Process for synthesizing luminescent material |
Country Status (2)
Country | Link |
---|---|
US (1) | US2210087A (de) |
DE (1) | DE685503C (de) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2973322A (en) * | 1955-11-17 | 1961-02-28 | British Thomson Houston Co Ltd | Luminescent materials |
US2984627A (en) * | 1957-12-03 | 1961-05-16 | Du Pont | Infrared-sensitive metal-activated zinc silicate phosphors and their preparation |
US3286754A (en) * | 1964-09-11 | 1966-11-22 | Veeder Root Inc | Self-locking set screw |
US3541019A (en) * | 1968-03-15 | 1970-11-17 | Grace W R & Co | Method of preparing a zinc silicate phosphor |
US4331706A (en) * | 1977-12-12 | 1982-05-25 | The Sherwin-Williams Company | Composite zinc oxide coating on an inert pigment core product and process |
US4892757A (en) * | 1988-12-22 | 1990-01-09 | Gte Products Corporation | Method for a producing manganese activated zinc silicate phosphor |
US4925703A (en) * | 1988-12-22 | 1990-05-15 | Gte Products Corporation | Firing and milling method for producing a manganese activated zinc silicate phosphor |
US4950948A (en) * | 1988-11-07 | 1990-08-21 | Gte Laboratories Incorporated | Manganese activated zinc silicate phosphor |
US4956202A (en) * | 1988-12-22 | 1990-09-11 | Gte Products Corporation | Firing and milling method for producing a manganese activated zinc silicate phosphor |
DE4008409A1 (de) * | 1990-03-16 | 1991-09-19 | Licentia Gmbh | Verfahren zur steigerung der helligkeit eines mit mangan aktivierten silikatleuchtstoffes |
US5188763A (en) * | 1986-08-29 | 1993-02-23 | Gte Products Corporation | Method for preparing zinc orthosilicate phosphor |
US5196234A (en) * | 1986-08-29 | 1993-03-23 | Gte Products Corporation | Method for preparing zinc orthosilicate phosphor particle |
US5611961A (en) * | 1994-09-14 | 1997-03-18 | Osram Sylvania Inc. | Method of preparing manganese activated zinc orthosilicate phosphor |
US20150337199A1 (en) * | 2012-10-31 | 2015-11-26 | Ocean's King Lighting Science & Technology Co., Ltd | Germanate luminescent material and preparation method therefor |
-
1934
- 1934-01-23 US US707866A patent/US2210087A/en not_active Expired - Lifetime
-
1935
- 1935-01-23 DE DER92411D patent/DE685503C/de not_active Expired
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2973322A (en) * | 1955-11-17 | 1961-02-28 | British Thomson Houston Co Ltd | Luminescent materials |
US2984627A (en) * | 1957-12-03 | 1961-05-16 | Du Pont | Infrared-sensitive metal-activated zinc silicate phosphors and their preparation |
US3286754A (en) * | 1964-09-11 | 1966-11-22 | Veeder Root Inc | Self-locking set screw |
US3541019A (en) * | 1968-03-15 | 1970-11-17 | Grace W R & Co | Method of preparing a zinc silicate phosphor |
US4331706A (en) * | 1977-12-12 | 1982-05-25 | The Sherwin-Williams Company | Composite zinc oxide coating on an inert pigment core product and process |
US5188763A (en) * | 1986-08-29 | 1993-02-23 | Gte Products Corporation | Method for preparing zinc orthosilicate phosphor |
US5196234A (en) * | 1986-08-29 | 1993-03-23 | Gte Products Corporation | Method for preparing zinc orthosilicate phosphor particle |
US4950948A (en) * | 1988-11-07 | 1990-08-21 | Gte Laboratories Incorporated | Manganese activated zinc silicate phosphor |
US4925703A (en) * | 1988-12-22 | 1990-05-15 | Gte Products Corporation | Firing and milling method for producing a manganese activated zinc silicate phosphor |
US4956202A (en) * | 1988-12-22 | 1990-09-11 | Gte Products Corporation | Firing and milling method for producing a manganese activated zinc silicate phosphor |
US4892757A (en) * | 1988-12-22 | 1990-01-09 | Gte Products Corporation | Method for a producing manganese activated zinc silicate phosphor |
DE4008409A1 (de) * | 1990-03-16 | 1991-09-19 | Licentia Gmbh | Verfahren zur steigerung der helligkeit eines mit mangan aktivierten silikatleuchtstoffes |
US5611961A (en) * | 1994-09-14 | 1997-03-18 | Osram Sylvania Inc. | Method of preparing manganese activated zinc orthosilicate phosphor |
US20150337199A1 (en) * | 2012-10-31 | 2015-11-26 | Ocean's King Lighting Science & Technology Co., Ltd | Germanate luminescent material and preparation method therefor |
US9650568B2 (en) * | 2012-10-31 | 2017-05-16 | Ocean's King Lighting Science & Technology Co., Ltd. | Germanate luminescent material and preparation method therefor |
Also Published As
Publication number | Publication date |
---|---|
DE685503C (de) | 1939-12-19 |
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