JPS636081A - Silicate phosphor - Google Patents

Abstract

PURPOSE:To improve a silicate phosphor contg. an Mn activator with respect to the initial degradation of luminance, afterglow, etc., by incorporating a trivalent element of boron and a pentavalent element selected from among As, Sb, and Bi in particular molar proportions. CONSTITUTION:Zinc oxide, silicon dioxide, manganese oxide, boron oxide, and an oxide of at least one pentavalent element selected from among arsenic, antimony, and bismuth are separately weighed in predetermined amts. and mixed together. The mixture is baked to prepare a intended silicate phosphor. The phosphor contains manganese as an activator, boron as a trivalent element and at least one member selected from among As, Sb, and Bi as a pentavalent element. The boron content is 2X10<-4>-2X10<-2>g-atom/mol or less, and the boron to pentavalent element molar ratio is 1.5 or more.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a silicate phosphor containing manganese as an activator, and more specifically, it relates to a silicate phosphor containing manganese as an activator, and more specifically, a silicate phosphor containing manganese as an activator. It relates to a silicate phosphor in which initial deterioration of brightness and afterglow is improved by containing the phosphor within a range of the ratio.

[Prior Art] In recent years, it has been desired to use high-resolution cathode ray tubes for computer terminal display devices, display devices for aircraft control systems, etc. that display minute characters and graphics.

The phosphor film of such a high-resolution cathode ray tube must be composed of a phosphor with long afterglow properties. This is because if the fluorescent film is composed of a short afterglow phosphor, the scanning speed of the fluorescent film is slow, causing flickering on the screen.

In general, the phosphor constituting such a phosphor film has an afterglow time (in this specification, the time required for the luminescence intensity to decrease to 10% of the excitation level after excitation is stopped, that is, "10% afterglow time"). The length of the short afterglow phosphor that constitutes the phosphor film of a normal cathode ray tube must be about ten to several tens of times longer.

However, as such long afterglow green-emitting zinc silicate phosphors, manganese and arsenic activated zinc silicate phosphors (
P39 phosphor) and manganese-activated zinc silicate phosphor (Pi phosphor) are known, and P39 phosphor in particular has high brightness and is used in large quantities.

However, as they have been used for various purposes, many drawbacks have been discovered in terms of brightness, afterglow, deterioration, coating properties, etc., and improvements in these areas have become strongly desired. For example, Japanese Patent Publication No. 57-48594, Japanese Patent Publication No. 58-151
No. 322 1% According to public publications such as No. 59-184281
Various compositions have been proposed.

However, display tubes made using silicate phosphors containing manganese as an activator display the same pattern on the tube surface for several to several tens of hours after manufacture, making it difficult to adjust the IJ nearness. Initial adjustments are made.

In the case of a phosphor film using a conventional silicate phosphor, as shown above, the afterglow in the area that is irradiated with the stain beam is shorter than that in the area that is not irradiated (initial afterglow deterioration), and the brightness is reduced. There were drawbacks such as a decrease in brightness (initial brightness deterioration). This makes the initial adjustment of the display tube complicated, requiring many cathode ray tubes to be knee-song for a long time, and subsequent deterioration is difficult to predict. Due to these reasons, it is difficult to set up each circuit of the product, and the initial adjustment is difficult. Turns may remain on the screen due to brightness deterioration, and flickering may occur due to partial afterglow deterioration.

There were various problems.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a silicate phosphor containing manganese as an activator, which significantly improves initial afterglow deterioration and initial brightness deterioration under excitation with an electron beam or the like.

In order to achieve the above object, the present inventors conducted various studies on silicate phosphors and found that a specific trivalent element and a specific trivalent element were found in silicate phosphors containing manganese as an activator. When the pentavalent element is contained in a specific molar ratio,
After discovering that the above-mentioned deterioration can be significantly improved, the present invention was devised. In addition.

In the above-mentioned Japanese Patent Publication No. 57-48594, the above-mentioned trivalent and 5-valent
Although a P39 phosphor containing equimolar amounts of valence elements has been disclosed, the present inventors have found that the above problem can be solved by using a different quantitative ratio.

The silicate phosphor of the present invention is a silicate phosphor containing manganese as an activator and containing trivalent and pentavalent elements.
The trivalent element is boron, the pentavalent element is at least one of arsenic, antimony, and bismuth, and the content of the trivalent element is 2 x 10"3 to 2 x 10 gram atom 1 mole, The content of pentavalent elements must be 3×10 gram atoms or less than 1 mole.

Further, the content kamol ratio of the trivalent and pentavalent elements (trivalent element to 15valent element) is 1.5 or more.

The most typical type of silicate phosphor containing manganese as an activator is a manganese-activated zinc silicate-based phosphor, but there are also manganese-activated magnesium silicate-based phosphors, for example. , divalent metal cation silicate phosphors such as manganese and lead activated calcium silicate phosphors.

Hereinafter, the present invention will be explained in detail based on the most typical method for producing a manganese-activated zinc silicate-based phosphor.

First, the raw material for the phosphor is 1) Zinc oxide (ZnO) or a zinc compound that can be easily converted to ZnO at high temperatures, such as carbonate, sulfurate, or ii)
Silicon dioxide (5tO2), ethyl silicate, silicic acid, and other silicon compounds that can be easily converted to StO Manganese compounds that can be converted to manganese oxides ■) Boron oxides or boron compounds that can easily be converted to boron oxides at high temperatures ■) Arsenic t Antimony and bismuth oxides or metals, herogonides, etc. Arsenic, antimony and bismuth or compounds thereof which can be easily converted into oxides of arsenic, antimony and bismuth are used.

The above-mentioned phosphor raw materials are weighed out and then thoroughly mixed to obtain a phosphor raw material mixture. Mixing is done using a ball mill.

It may be carried out in a dry manner using a mixer mill, a mortar, etc., or it may be carried out in a mixed manner using water, alcohol, weak acid, etc. as a medium in a single stroke state. The luminance of the resulting phosphor,
For the purpose of improving powder properties etc., a fluxing agent may be further added and mixed into the phosphor raw material mixture.

In addition, when iv) and v) of the above raw materials are fired at high temperature,
Since that part tends to volatilize, it is added in small amounts depending on the firing temperature and time.

Next, the above-mentioned phosphor raw material mixture is filled into a heat-resistant container such as an aluminum quartz container and fired. Firing is carried out at 1000°C to 1350°C in air (oxidizing atmosphere), in a neutral atmosphere such as a nitrogen gas atmosphere or argon gas atmosphere, or in a reducing atmosphere such as a nitrogen gas atmosphere containing a small amount of hydrogen gas or a carbon atmosphere. , preferably from 1200°C
This is carried out once or several times (3 to 4 times) at a temperature of 1300°C.

Further, even better results can be obtained if the base material of the phosphor is pre-sintered at 500 DEG C. to 1300 DEG C. and the grain size of the base material is grown.

The firing time varies depending on the amount of the phosphor raw material mixture filled in the heat-resistant container, the firing temperature employed, etc., but in general, 0.5 to 6 hours is appropriate in the above firing temperature range, and 1 to 6 hours.
4 hours is preferred. After firing, the fired product obtained is subjected to various operations generally employed in the field of phosphor manufacturing, such as crushing, washing (this may be done with water, weak mineral acids, weak alkalis, weak organic acids, etc.), drying, and sieving. After processing, the phosphor of the present invention can be obtained.

The thus obtained phosphor of the present invention and the conventional zinc silicate phosphor (P39) were each applied uniformly onto a glass plate by a sedimentation coating method to form a phosphor film, and then a fluorescent film was formed on the tube. Display tubes were manufactured according to the manufacturing method, and the emission intensity deterioration characteristics due to continuous excitation of the fluorescent surface were measured using each display tube. The results are shown in FIG. .

According to the figure, it is clear that the zinc silicate phosphor of the present invention has significantly better luminous intensity deterioration characteristics than conventional products.

Next, Table 1 shows the results of measuring afterglow deterioration characteristics.
It is clear that the zinc silicate phosphor of the present invention has better afterglow deterioration characteristics than conventional products.

Table 1 and Figure 2 show the relationship between initial afterglow deterioration characteristics and boron content. Figure 3 shows the relationship between the arsenic content and molar ratio (trivalent element and 15-valent element), 1/10 afterglow time, and afterglow deterioration characteristics when the contents of boron and antimony are kept constant. Something to show.

Figure 4 shows that when the boron content is constant, antimony,
Arsenic content and solubility ratio (trivalent element and 15valent element)
This shows the relationship between 1/10 afterglow time and afterglow deterioration characteristics.

According to the above graph, the boron content is 2X10”-4 ~
2 x 10 grams atom 1 mole, pentavalent element is 3 x 1
It is appropriate that the molar ratio of boron and the content of pentavalent elements (trivalent elements and 15-valent elements) be 1.5 or more. It is appropriate that the upper limit is 500 when the pentavalent element is only arsenic, and 50 when the pentavalent element is at least one of antimony and bismuth.

In the following, the examples will be explained, and the test methods used therein will be described.

Measuring method using a demakutuple device: (() Preparation of test piece: Apply the phosphor to be inspected to a 2.5 x 35 m test piece by a sedimentation method to form a fluorescent film.

(b) Electron beam irradiation The above test piece was set in a demountable electron beam stimulator (manufactured by our company), and the acceleration voltage was 20 kV and the current density was 1 μ.
A1512, raster size 1×1α, and electron beam irradiation for 20 minutes.

(c) Luminance measurement During the above electron beam irradiation, the luminance was measured at 1 minute intervals using a luminance meter.

b) Afterglow measurement Measure the 1710 afterglow time under the following conditions before and after electron beam irradiation.

Acceleration voltage 15 kV % Pulse width 102.4 mm, 7'
Excite with a non-polarized and defocused beam with a unity of 50%. The current density was 0.5 μA/cm”.

Example 1 Zinc oxide Zn0 370 1 to silicon oxide 5102150 Ii manganese carbonate
MnC0,” 0.5 B20 2.5 to antimony oxide 5b2031.OII 0.5 to the above raw material
mol/l B2O3 aqueous solution 25-1o, os mol/l At 20. Add 5 parts of aqueous solution and 1.5 parts of pure water, perform wet gall milling, then dry and pulverize this material. and fired in nitrogen atmosphere at 1300°C for 4 hours. This fired product was crushed, washed and dried, and the composition formula was Zn2SiO4:MnO,008AI0.00fH
, BO, 005, and SbO, 002 of the present invention were obtained. This phosphor contains the trivalent element boron, 0.005 gram atom/(ZtL2SiO4 1 mol), and the pentavalent elements arsenic and antimony, 0.0021 gram atom/(Zt+2SL041 mol). , the molar ratio of the content (trivalent element and 15-valent element) is 2.387
be.

This phosphor was used as a phosphor film, and the luminescence intensity maintenance rate was measured after performing the above-mentioned intensity deterioration test.

The luminescence intensity maintenance rate was 99%. Also, ZnS104 manufactured by the same method: ! 'In0.008. AaO,
The emission intensity maintenance rate of the o01 fluorophore is 94%, which is impressive.

Further, the phosphor film of the phosphor of the present invention did not suffer from afterglow deterioration.

Example 2 Zinc oxide Zn0 390 Silicon oxide 810□ 150 I Manganese carbonate Mn
CO3-0,5H201,5,9 Boron trioxide B20
30.5 # Arsenic trioxide Ag2O3o, o 511 The above raw materials were sufficiently pulverized and mixed in a dry type Ga-lumil, filled with alumina, fired in air at 1250'C for 14 hours, and then the composition formula was prepared in the same manner as in Example 1. is””o4’”0.005
．． 0.0001. A phosphor of the present invention of BO,006 was obtained.

The molar ratio of this phosphor (trivalent element and 15-valent element) is 60
The luminescence intensity maintenance rate was 99%, and there was no afterglow deterioration.

Example 3 Zinc oxide ZnO370j' Silicon dioxide 5102 150 1 Manganese carbonate MnC0,' 0.5 H2O5jl Antimony trioxide 5b20! L O
, 51 After adding an appropriate amount of pure water to the above raw materials and mixing thoroughly to form a paste, a 0.5 mol/l B2O3 aqueous solution 5 and a 0.05 mol/l As2O5 aqueous solution 5 were added and further mixed. Thereafter, firing, cleaning, etc. were performed in the same manner as in Example 1, and the composition formula was Zn25tO4:Mn, ). 5
゜Ago,. . . 1. B.O. . 2. Sbo,. . A phosphor of the present invention was obtained.

The molar ratio of this phosphor (trivalent element to 15 valent element) is approximately 1
．． 8, the emission intensity maintenance rate was 98%, and there was no afterglow deterioration.

Example 4 Zinc oxide Zn0 390 and silicon oxide SiO□ 150.9 manganese carbonate
MnCO3・0.5H202,5E Borax
NIL2B407・l0H202, Og arsenic trioxide
AJ203 o, o 51 antimony trioxide 5b20. 0.5N The above raw materials were thoroughly mixed in a dry gold mill, filled into an alumina crucible, and fired in air at 1250°C for 4 hours.The composition formula was 2 4 0.008.
O, [+001. A phosphor of the present invention Za S10:MnAs of BO,004,SbO,001 was obtained. The molar ratio of this phosphor (trivalent element and 15-valent element) is approximately 5.5, and the emission intensity maintenance rate is 9.
8%, and there was no afterglow deterioration. Note that a trace amount of Na was detected in the matrix of this phosphor.

Example 5 Zinc oxide ZnO370, silicon oxide sto□ 150 g manganese carbonate MIICo, 0.5H202,5,9 boron trioxide B2030.5,! ? Arsenic trioxide A
s2O3o, o 51 antimony trioxide 5b20.
1. 9 Barium iodide BaI2
2.5 11 Thoroughly grind and mix the above raw materials in a dry gall mill.

Aluminum Naruto? After firing in air at 1250° C. for 4 hours, a phosphor having the composition formula % brightness was obtained in the same manner as in Example 1. The molar ratio of this phosphor (trivalent element 1
(pentavalent element) is approximately 2.9, and the emission intensity maintenance rate is 99.
%, and there was no afterglow deterioration. In addition, 0.1% by weight of B& was detected in the matrix of this phosphor.

〔Effect of the invention〕

According to the above-described first aspect of the present invention, in a silicate phosphor containing manganese as an activator, a specific trivalent element and a pentavalent element are contained in a specific quantitative ratio range, so that brightness and afterglow are improved. The initial deterioration of can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the luminescence intensity deterioration characteristics comparing the zinc silicate phosphor of the present invention and the conventional one, and Fig. 2 shows the initial afterglow deterioration characteristics of the zinc silicate phosphor and the boron content and mole. A graph showing the relationship between the ratio (trivalent element and 15-valent element), Figure 3 shows the relationship between boron and antimony when the content of boron and antimony is constant.
Arsenic content and molar ratio (trivalent element and 15valent element)
Figure 4 is a graph showing the relationship between 1/1° afterglow time and afterglow deterioration characteristics. 10 is a graph showing the relationship between elements), 1/10 afterglow time, and afterglow deterioration characteristics. Representative Patent Attorney Johei Yamashita Procedural Amendment July 30, 1986 Commissioner of the Japan Patent Office Kuro 1) Akio Tono1, Indication of Case Patent Application No. 148035/19812, Name of Invention Silicate Phosphor 3, Relationship with the case of the person making the amendment Patent applicant name: Kasei Optonics Co., Ltd. 4, agent address: Mori Building, 40 Toranomon, 5-13-1 Toranomon, Minato-ku, Tokyo Power of attorney, specification and drawings 6, contents of the amendment ( 1) Supplement the power of attorney as shown in the attached sheet. Procedural amendment September 25, 1988 Commissioner of the Patent Office Black 1) Akio Yu 1, Indication of the case Japanese Patent Application No. 148035/1988 2, Name of the invention silicate phosphor 3, Person making the amendment Relationship to the case Patent applicant name: Kasei Optonics Co., Ltd. 4, agent address: 40 Toranomon, Mori Building, 5-13-1 Toranomon, Minato-ku, Tokyo;
Simplification of Drawings 6, Contents of Corrections 11) The scope of claims stated on pages 1 to 3 of the specification will be corrected as shown in the attached sheet. (21 Ibid. 1, page 4, line 1, ``It is necessary to be composed of a phosphor.'', and the following sentence, up to ``It is for this reason.'' 13) On page 4, lines 7 and 8 of the same number, correct the phrase ``the time required for the temperature to drop to 10-, that is, the rtos afterglow time'' to drop to rl/10. The amount of time required to do this, i.e. r 1/10 afterglow time.'' (4) Delete "Because the brightness is high" in the 16th line of the 4th page of the same number. (5) "Mixed method" on page 8, line 18 of the same number is corrected to "wet method." (6) In the 5th line from the bottom of the 11th page of the same book, after "Indicates.", insert "Figure 5 shows the relationship between relative brightness and boron content." (7) Correct "antimony dioxide" in line 10 of page 13 of 1IllF to "antimony dioxide". (8) In the same book, page 13, line 12, “As2O3J is
A1. Corrected to "O6". (r ZnS to4 on page 11114, line 6 of 91:
MnO,008. AsO,0OIJ to rZn,5in4:Mn0.00
8. Corrected to AsO, 0O01J. IjG Same book, page 14, second line from the bottom r Zn5iO
Correct 4J to rZn5iO4J. αυ Same, 1#E15 member 13th row 13r Mn0.0
5 J t”rMno, correct to 015. +13 The following sentence ( Example 6) is additionally inserted. "Example 6 Zinc oxide ZnO370,9 Silicon dioxide Sin, 150 N manganese carbonate MnC0,"O5H,02,511 Boron trifluoride"203 o, 5g Antimony dioxide 5b2031 #The above raw materials were mixed by optical pulverization in a dry ball mill. , fill the alumina crucible, 1
After firing in air at 250°C for 4 hours, the same *K as in Example 1 was applied. ma: Formula is Zn25iOa: MnO, 008, Bo,
006, Sb0.002 &'' invention phosphor was obtained. The molar ratio of this phosphor (3 gft of elements with 15 valence elements) was 3, the luminescence intensity maintenance rate was 99 or better, and there was no deterioration of the residual element. 03 In the 8th line of page 18 of the same 1, the phrase ``This is a graph showing the relationship.'' was replaced with ``The graph showing the relationship.'' .” is corrected. α4 Add Figure 5 of the drawing as attached. At the same time, Figures 1 to 4 are corrected as shown in the appendix.Claim (1) In a silicate phosphor containing manganese as an activator and containing a trivalent element and an element of 51ff:
The 311ffi element is boron, the pentavalent element is arsenic,
At least one of antimony and bismuth,
The content of the trivalent element is 2 X 10-3 to 2 X 1
0-” gram atom 1 mole, the content of the pentavalent element is 3
X 10""" Gram atom 1 mole or less is 6, and the molar ratio of the content of the above trivalent and 51i!Ii elements (elements on the 751 side of the trivalent element) is 1.5 or more (21) The silicate phosphor according to claim 1, characterized in that the arsenic content; @The content of trivalent elements is I x 10-3
The silicate phosphor according to claim 1 or 2, characterized in that the content is in the range of 1 to 10-3 gram atoms per mole: (4) The molar ratio of the content (trivalent 15-valent element)
is 1.8 or more. The silicate phosphor according to any one of claims 1 to 3, wherein: (5) the pentavalent element consists only of arsenic; The silicate phosphor according to any one of claims 1 to 4, wherein the molar ratio of the content (trivalent element and 15-valent element) is 5 or more: 16) The arsenic content is I x 10-3 to 8
X 10-' gram atom 1 mole of silicic acid according to any one of claims 2 to 5, characterized in that: 10~3X
The silicate phosphor according to any one of claims 1 to 6, characterized in that the silicate phosphor has a luminescence in the range of 10 −2 gram atoms per mole: (8) The activation amount of the manganese is 2× 10~l×10
A characteristic f characterized in that it is in the range of 1 mole of gram atoms.
Range of f product calculation silicate phosphor according to item 7:

Claims (9)

[Claims] (1) In a silicate phosphor containing manganese as an activator and containing a trivalent element and a pentavalent element, the trivalent element is boron, and the pentavalent element is arsenic, antimony, and bismuth. and the content of the trivalent element is 2 x 10^-^4 to 2 x 10^-^2 gram atoms/mol, and the content of the pentavalent element is 3 x 10^- ^3 gram atom/mol or less, and a silicate characterized in that the molar ratio of the content of the trivalent and pentavalent elements (trivalent element/pentavalent element) is 1.5 or more. Fluorescent material: (2) Claim 1, characterized in that the silicon content is 1×10^-^3 gram atoms/mol or less.
Silicate phosphor described in section: (3) The content of the trivalent element is 1×10^-^3~1
A silicate phosphor according to claim 1 or 2, characterized in that the silicate phosphor is in the range of x10^-^2 gram atoms/mole: (4) Molar ratio of the above content (trivalent element/pentavalent element)
The silicate phosphor according to any one of claims 1 to 3, characterized in that 1.8 or more: (5) Claim 1, wherein the pentavalent element is only arsenic, and the molar ratio of the content (trivalent element/pentavalent element) is 5 or more. or Section 4. The silicate phosphor according to any one of: (6) The arsenic content is 1 x 10^-^4 to 8 x 10
A silicate phosphor according to any one of claims 2 to 5, characterized in that the phosphor is in the range of ^-^4 gram atoms/mole: (7) The activation amount of the manganese is 1×10^-^3~3×
A silicate phosphor according to any one of claims 1 to 6, characterized in that the phosphor is in the range of 10^-^2 gram atoms/mole: (8) The activation amount of the manganese is 2×10^-^3 to 1×
A silicate phosphor according to claim 7, characterized in that it is in the range of 10^-^2 gram atoms/mole: (9) The pentavalent element is arsenic, and the arsenic and boron contents are each 1 x 10^-^4 to 1 x 10^-
^3 gram atoms/mol and 3 x 10^-^3~1.2 x
A silicate phosphor according to any one of claims 1 to 4, characterized in that it is in the range of 10^-^2 gram atoms/mole: