DE4212170A1 - White light emitting fluorescent material - does not contain environmentally hazardous cadmium@ and has a higher brightness than current materials - Google Patents

Abstract

The white light emitting fluorescent material consists of a yellow light emitting material with at least one of the following cpds.: (Ca1-xMgx)S:Mn and (Ca1-xMgx)S:Mn,Sc, contg. not more than 500 ppm Sc in its matrix, with x between 0 and 0.05 and a blue light emitting material. The blue emitting material is at least one of the cpds.: ZnS:Ag, ZnS:Ag,Cl, ZnS:Ag,Ga and ZnS:Ga,Cl. with the Ga-content in the last 2 cpds. not more than 100 ppm. The mixture pref. consists for between 30 and 70% of the yellow emitting cpd., the rest blue emitting material. Also claimed is the white light emitting fluorescent material consisting of a mixt. of the above cpds. and additionally a green light emitting fluorescent material consisting of ZnS:Cu,Cl pref. with the mixing ratios: yellow:blue:green = (30-70):(10-40):(10-50) in wt.%. In the above fluorescent mixt. the max. content of Sc in the yellow emitting material is pref. 300 ppm relative to its matrix, and the amt. of Ga in the blue emitting cpds. is pref. not more than 100 ppm. Also claimed is the use of InBO3:Tb, Zn2SiO4:Mn and/or ZnSi04:Mn,As as a green emitting fluorescent material. In this case the mixing ratios of yellow:blue:green are (30-780):(15-40):(15-30) wt.%. The Sc content pref. is not more than 300 ppm of its matrix and of Ga not more than 100 ppm of its matrix. USE/ADVANTAGE - The mixtures are free of the environmentally hazardous Cd which is used in conventional material and have a higher light emission level. The mixtures also cover a larger range of shades of white light. The material is used in the mfr. of monochrome cathode ray tube

Description

The present invention relates to a white light emitting phosphor, in particular a white light emitting phosphor by mixing yellow Light emitting phosphor and blue light emit the phosphor may also have a green light emitting phosphor is produced.

One currently for a monochromatic cathode ray Tube used, white light-emitting phosphor is a mixture of blue light emitting phosphor and yellow light-emitting phosphor in the right one Quantitative ratios. The white hue of white light emitting phosphor is determined by the mixing ratio of the determined two components, the mixing ratio each can be regulated as required.  

As sources that emit white light Phosphor using a mixed phosphor U.S. Patent Nos. 38 91 886 and 46 94 217 can be specified. U.S. Patent No. 3,891,886 describes one white light-emitting mixture that consists essentially of a blue light emitting silver activated zinc sul fid fluorescent [ZnS: Ag] and a yellow light-emitting copper and aluminum activated zinc cadmium sulfide light fabric [(Zn, Cd) S: Cu, Al]. In this case, however the long-term use of a cathode ray tube that the ZnS system phosphor used as blue phosphor, too a decrease in fluorescent luminance. Furthermore, the CdS system phosphor has the disadvantage that it has Um pollution is not very desirable.

US Pat. No. 4,694,217 describes a white light-emitting phosphor which essentially consists of a blue phosphor having the composition formula (M _1-x Tb _x ) ₂O₂S (where M is one of the compounds Y and / or Gd and the X- Range 0 <X0.01) and at least one phosphor that does not contain Cd. Other phosphors are a second green or yellow phosphor, which is one of the compounds ZnS: Au, Al and / or Zn ₂ SiO ₄ : Mn, and a third red phosphor, which is one of the compounds Y₂O₂: Eu, InBO₃: Eu and / or Zn₃ (PO₄) ₂: Mn is. This white light-emitting phosphor, which consists of the blue and the green or yellow phosphor, has a sufficient degree of luminance, but produces a white color with a green tinge.

The one to correct such a color deviation bene red fluorescent diminished because of its own clot luminance the luminance of the white light fluorescent.

The object of the invention is to emit white light To provide phosphors that have high luminance and no pollution related problems point, and the a white color of any tone  Selection of the phosphors to be mixed in the corresponding Can generate quantities.

According to an embodiment of the present Invention before a white light emitting phosphor seen the yellow light-emitting phosphor and has a blue light emitting phosphor, wherein the yellow light emitting phosphor is one of the links

(Ca _1-x Mg _x ) S: Mn (0 x 0.05)

and or

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05)

is, and the blue light emitting Phosphor one of the compounds ZnS: Ag, ZnS: Ag, Ga, ZnS: Ag, Cl and / or ZnS: Ag, Ga, Cl.

The preferred mixing ratio of the yellow light emitting fluorescent and blue light the phosphor is between 30 and 70 wt .-% and zwi 70 and 30 wt .-%.

The preferred amount of activator Sc added yellow light-emitting phosphor

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.5)

is not greater than 500 ppm based on the weight of the matrix (Ca _1-x Mg _x ) S, and the amount of activator Ga in the blue light-emitting phosphor ZnS: Ag, Ga or ZnS: Ag, Ga, Cl is not greater than 100 ppm, based on the weight of the matrix ZnS.

As another embodiment, the present Invention also a white light-emitting phosphor available that emits a yellow light, one emitting blue light and emitting a green light renden fluorescent, the yellow light emit fluorescent at least one of the compounds

(Ca _1-x Mg _x ) S: Mn (0 <x <0.05)

and or

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05)

the blue light-emitting phosphor is at least one of the compounds ZnS: Ag, ZnS: Ag, Ga, ZnS: Ag, Cl and / or ZnS: Ag, Ga, Cl is, and the green light emitting Phosphor ZnS: Cu, Cl is.

The preferred mixing ratio of the yellow light emitting phosphor, the blue light emitting Phosphor and the green light emitting phosphor  is between 30 and 70% by weight, between 10 and 40% by weight and between 10 and 50% by weight.

The preferred amount of the yellow light emitting Fluorescent

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05)

added activator Sc is not greater than 300 ppm, based on the weight of the matrix (Ca _1-x Mg _x ) S, and the amount of activator Ga in the blue light-emitting phosphor ZnS: Ag, Ga or ZnS: Ag, Ga, Cl is not greater than 100 ppm based on the weight of the ZnS matrix.

As a third embodiment, the present Er finding a white light-emitting phosphor Of a yellow light-emitting phosphor, a blue light-emitting phosphor and a green Nes light-emitting phosphor, the yellow light-emitting phosphor at least one of the links

(Ca _1-x Mg _x ) S: Mn (0 x 0.05)

and or

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05)

is the blue light emitting Phosphor at least one of the compounds ZnS: Ag, ZnS: Ag, Ga, Zns: Ag, Cl and / or ZnS: Ag, Ga, Cl, and the green light emitting phosphor at least one of the Compounds InBO₃: Tb, Zn₂SiO₄: Mn and / or Zn₂SiO₄: Mn, As is.

The preferred mixing ratio of the yellow light emitting phosphor, the blue light emitting Fluorescent, and the green light-emitting light Substance is between 30 and 70% by weight, between 15 and 40 % By weight and between 15 and 30% by weight.

The preferred amount of activator Sc added yellow light-emitting phosphor

(Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05)

is not greater than 300 ppm based on the weight of the matrix (Ca _1-x Mg _x ) S, and the amount of activator Ga in the blue light-emitting phosphor ZnS: Ag, Ga or ZnS: Ag, Ga, Cl is not greater than 100 ppm based on the weight of the matrix ZnS.

A brief description of the drawings follows:

. Figure 1 is a CIE chromaticity diagram showing the white light-emitting phosphors 1-17 of the present invention are prepared according to Examples;

Figure 2 is a CIE chromaticity diagram of the white light emitting phosphors made in accordance with Examples 18-26 of the present invention; and

Figure 3 is a CIE chromaticity diagram of the white light emitting phosphors made according to Examples 27-35 of the present invention.

The present invention will now be illustrated by the examples explained in more detail.

example 1

CaS: Mn, Sc as a yellow light-emitting phosphor, in which the added amounts of activators Mn and Sc 100 ppm or 10 ppm based on the matrix were GaS, and ZnS: Ag as a blue light-emitting phosphor, in which the amount of activator Ag added based on 10 ppm the matrix was ZnS, were obtained in a known manner poses. CaS: Mn, Sc and ZnSI: Ag were compared in a weight ratio of 30:70 to a white light emitting Fluorescent mixed.

Examples 2-5

The same phosphors as in Example 1, CaS: Mn, Sc and ZnS: Ag were in the weight ratios 40:60 (at game 2), 50:50 (example 3), 60:40 (example 4) and 70:30 (Example 5) to a white light-emitting phosphor mixed.

Example 6

CaS: Mn as a yellow light-emitting phosphor 100 ppm Mn activator, and ZnS: Ag, Ga as blue light emit animal phosphor with 10 ppm Ag activator and 10 ppm Ga  Activators were made in a known manner. CaS: Mn and ZnS: Ag, Ga were added in a weight ratio of 30:70 mixed with a white light-emitting phosphor.

Examples 7-10

The same phosphors as in Example 6, CaS: Mn and ZnS: Ag, Ga were in the weight ratios 40:60 (bei game 7), 50:50 (example 8), 60:40 (example 9) and 70:30 (Example 10) to a white light-emitting light mixed fabric.

Example 11

(Ca _0.95 Mg _0.05 ) S: Mn, Sc as a yellow light-emitting phosphor with 3000 ppm Mn activator and 500 ppm Sc activator, and ZnS: Ag, Ga, Cl as a blue light-emitting phosphor and 200 ppm Ag Activator and 100 ppm Ga activator were produced in a known manner. (Ca _0.95 Mg _0.05 ) S: Mn, Sc and ZnS: Ag, Ga, Cl were mixed in a weight ratio of 30:70 to form a white light-emitting phosphor.

Examples 12-15

The same phosphors as in Example 11, (Ca _0.95 Mg _0.05 ) S: Mn, Sc and ZnS: Ag, Ga, Cl, were in the weight ratio 40:60 (Example 12), 50:50 (Example 13 ), 60:40 (Example 14) and 70:30 (Example 15) to a white light-emitting phosphor.

Example 16

(Ca _0.98 Mg _0.02 ) S: Mn, Sc as a yellow light-emitting phosphor with 1000 ppm Mn activator and 100 ppm Sc activator, and ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 130 ppm Ag Activator and 30 ppm Ga activator were made in a known manner. (Ca _0.98 Mg _0.02 S: Mn, Sc and ZnS: Ag, Ga, Cl were mixed in a weight ratio of 60:40 to form a white light-emitting phosphor.

Example 17

(Ca _0.97 Mg _0.03 ) S: Mn, Sc as a yellow light-emitting phosphor with 2000 ppm Mn activator and 50 ppm Sc activator, and ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 50 ppm Ag activator and 20 ppm Ga activator was produced in a known manner. (Ca _0.97 Mg _0.03 ) S: Mn, Sc and ZnS: Ag, Ga, Cl were mixed in a weight ratio of 55:45 to form a white light-emitting phosphor.

Then the relative luminance of the white light-emitting phosphor was examined according to Examples 1-17. The results are shown in the following Table 1 in comparison with the mixture consisting of InBO ₃ , InBO ₃ : Eu and ZnS: Ag, the white light-emitting mixture (standard, luminance 100%). Furthermore, the CIE chromaticity coordinates of the white light-emitting phosphors according to Examples 1-17 were examined. The results are shown in Table 1 and Fig. 1.

Table 1

According to Table 1, the relative luminance of the The phosphors of the present invention are 13 to 20% higher than the luminance of the standard phosphor. Furthermore were the CIE chromaticity coordinates of the phosphors before lying invention less than that of the standard lamp fabric.

Example 18

CaS: Mn as a yellow light-emitting phosphor, ZnS: Ag, Cl as a blue light emitting phosphor and ZnS: Cu, Cl as a green light-emitting phosphor made in a known manner.

CaS: Mn, ZnS: Ag, Cl and ZnS: Cu, Cl were compared in weight ratio of 60:20:20 to a white light emitting Fluorescent mixed.

Example 19

CaS: Mn, Sc as a yellow light-emitting phosphor with 300 ppm Sc activator, ZnS: Ag, Ga, Cl as blue light emit animal phosphor with 100 ppm Ga activator, and ZnS: Cu, Cl as a green light emitting phosphor made a known way. CaS: Mn, Sc, ZnS: Ag, Ga, Cl and ZnS: Cu, Cl were added in a weight ratio of 70:20:10 mixed with a white light-emitting phosphor.

Examples 20-24

The same phosphors as in Example 19 CaS: Mn, Sc, ZnS: AG, Ga, Cl and ZnS: Ca, Cl were compared in a weight ratio ratio of 60:20:20 (example 20), 50:20:30 (example 21), 40:20:40 (example 22), 30:20:50 (example 23) and 60:10:30 (Example 24) to a white light-emitting light mixed fabric.  

Example 25

(Ca _0.95 Mg _0.05 ) S: Mn, Sc as a yellow light-emitting phosphor with 30 ppm Sc activator, ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 20 ppm Ga activator and ZnS: Cu, Cl as green light emitting phosphor was manufactured in a known manner. (Ca _0.95 Mg _0.05 ) S: Mn, Sc, ZnS: Ag, Ga, Cl and ZnS: Cu, Cl were mixed in a weight ratio of 50:30:20 to form a white light-emitting phosphor.

Example 26

The same phosphors as in Example 25, (Ca _0.95 MG _0.05 ) S: Mn, Sc, ZnS: Ag, Ga, Cl and ZnS: Cu, Cl were mixed in a weight ratio of 50:40:10 mixed white light-emitting phosphor.

Then the relative luminance of the white light-emitting phosphor was examined according to Examples 18-26. The results are shown in Table 2 below in comparison with the white light-emitting mixture of InBO ₃ : Tb, InBO ₃ : Eu and ZnS: Ag as standard (luminance 100%). Furthermore, the CIE chromaticity coordinates of the white light-emitting phosphors according to Examples 18-26 were investigated. The results are shown in Table 2 and Fig. 2.

Table 2

According to Table 2, the relative luminance of the Phosphors of the present invention are 27-37% higher than that of the standard fluorescent.

Example 27

CaS: Mn as a yellow light-emitting phosphor 1500 ppm Mn activator, ZnS: Ag as a blue light emitting Phosphor with 130 ppm Ag activator and InBO₃: Tb as green Light emitting phosphor with 700 ppm Tb activator were made in a known manner.

CaS: Mn, ZnS: Ag and InBO₃: Tb were in one weight ratio of 50: 20: 30 to a white light emitting Fluorescent mixed.

Example 28

The same CaS: Mn and ZnS: Ag as in Example 27, and Zn ₂ SiO ₄ : Mn instead of InBO ₃ : Tb in Example 27 as a green light-emitting phosphor were used in a weight ratio of 50:20:30 to a white light emitting phosphor mixed.

Example 29

CaS: Mn, Sc as a yellow light-emitting phosphor with 1000 ppm Mn activator and 100 ppm Sc activator, ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 50 ppm Ag activator and 20 ppm Ga activator, and InBO ₃ : Tb and Zn ₂ SiO ₄ : Mn, As as two green light-emitting phosphors were produced in a known manner. CaS: Mn, Sc, ZnS: Ag, Ga, Cl, ZnBO ₃ : Tb and Zn ₂ SiO ₄ : Mn, As were mixed in a weight ratio of 50: 20: 20: 10 to a white light emitting the phosphor.

Example 30

(Ca _0.95 Mg _0.05 ) S: Mn, Sc as a yellow light-emitting phosphor with 3000 ppm Mn activator and 300 ppm Sc activator, ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 200 ppm Ag activator and 100 ppm Ga activator, and InBO ₃ : Tb with 1500 ppm Tb activator and Zn ₂ SiO ₄ : Mn, As as two green light-emitting phosphors were produced in a known manner. (Ca _0.95 Mg _0.05 ) S: Mn, Sc, ZnS: Ag, Ga, Cl, In-BO ₃ : Tb and Zn ₂ SiO ₄ : Mn, As were in a weight ratio of 40:30:20: 10 mixed to a white light-emitting phosphor.

Example 31

(Ca _0.98 Mg _0.02 ) S: Mn, Sc as a yellow light-emitting phosphor with 2000 ppm Mn activator and 30 ppm Sc activator, ZnS: Ag, Ga, Cl as a blue light-emitting phosphor with 50 ppm Ag activator and 10 ppm Ga activator, and InBO ₃ Tb with 3000 ppm Tb activator and Zn ₂ SiO ₄ : Mn, As as two green light emitting phosphors were prepared in a known manner. (Ca _0.98 Mg _0.02 ) S: Mn, Sc, ZnS: Ag, Ga, Cl, In-BO ₃ : Tb and Zn ₂ SiO ₄ : Mn, As were in a weight ratio of 30:40:10: 20 mixed into a white light-emitting phosphor.

Examples 32-35

The same phosphors as in Example 31, (Ca _0.98 Mg _0.02 ) S: Mn, Sc, ZnS: Ag, Ga, Cl, InBO ₃ : Tb and Zn ₂ SiO ₄ : Mn, As were 50 in weight ratios : 30: 10: 10 (example 32), 60: 25: 10: 5 (example 33), 70: 15: 10: 5 (example 34) and 60: 20: 5: 15 (example 35) too white light emitting phosphors mixed.

Then the relative luminance of the white light-emitting phosphor was examined according to Examples 27-35. The results are shown in Table 3 below in comparison with the white light-emitting mixture of InBO ₃ : Tb, InBO ₃ : Eu and ZnS: Ag as standard (luminance 100%). Furthermore, the CIE chromaticity coordinates of the white light-emitting phosphors according to Examples 27-35 were examined. The results are shown in Table 3 and Fig. 3.

Table 3

According to Table 3, the relative luminance of the Phosphors according to the present invention between 13 and 20% higher than that of the standard phosphor.

Fig. 1, 2 and 3 are CIA Chromatizitätsdiagramme the white light-emitting phosphors are shown the playing 1-17, 18-26, or 27-35 invention.

Referring to FIGS. 1 through 3, the white light emit animal forming phosphors of the present invention exhibit a wide range of the CIE chromaticity coordinate, based on the white color dot (W). A white color with any tint can be made available by selecting and mixing the respective phosphors.

As explained above, the white light emit the phosphors of the present invention Luminance and white tones over a wide range and they do not cause pollution.

Claims (12)

1. White light-emitting phosphor which contains a yellow light-emitting phosphor and a blue light-emitting phosphor, the yellow light-emitting phosphor comprising at least one of the compounds (Ca _1-x Mg _x ) S: Mn (0 x 0.05 ) and (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05) and the blue light-emitting phosphor at least one of the compounds ZnS: Ag, ZnS: Ag, Ga, ZnS: Ag, Cl and / or ZnS: Ag, Ga, Cl are. 2. White light-emitting phosphor according to claim 1, wherein the mixing ratio of the yellow light emits fluorescent and blue light emitting Phosphor between 30 and 70 wt .-% and between 70 and 30 wt .-% is. 3. The white light-emitting phosphor according to claim 2, wherein the amount of the activator Sc added to the yellow light-emitting phosphor (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05) is not more than 500 ppm by weight the matrix is (Ca _1-x Mg _x ) S. 4. White light-emitting phosphor according to claim 2, the phosphor emitting the blue light ZnS: Ag, Ga or ZnS: Ag, Ga, Cl added amount of the asset tors Ga not greater than 100 ppm based on the weight of the Matrix ZnS is. 5. White light-emitting phosphor which contains a yellow light-emitting phosphor, a blue light-emitting phosphor and a green light-emitting phosphor, the yellow light-emitting phosphor comprising at least one of the compounds (Ca _1-x Mg _x ) S: Mn (0 x 0.05) and / or (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05), the blue light-emitting phosphor is at least one of the compounds ZnS: Ag, ZnS: Ag, Ga , ZnS: Ag, Cl and / or ZnS: Ag, Ga, Cl, and the green light-emitting phosphor ZnS: Cu, Cl. 6. White light-emitting phosphor according to claim 5, wherein the mixing ratio of the yellow light emitted fluorescent, the blue light emitting light fabric and the green light-emitting phosphor between between 30 and 70% by weight, between 10 and 40% by weight and between is 10 and 50 wt .-%. 7. The white light-emitting phosphor according to claim 6, wherein the amount of the activator Sc added to the yellow light-emitting phosphor (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05) is not greater than 300 ppm, based on is the weight of the matrix (Ca _1-x Mg _x ) S,. 8. White light-emitting phosphor according to claim 6, the amount of the blue light emitting Phosphor ZnS: Ag, Ga or ZnS: Ag, Ga, Cl amount added of the activator Ga is not greater than 100 ppm, based on that Weight of the matrix ZnS, is. 9. A white light-emitting phosphor which contains a yellow light-emitting phosphor, a blue light-emitting phosphor and a green light-emitting phosphor, the yellow light-emitting phosphor comprising at least one of the compounds (Ca _1-x Mg _x ) S: Mn (0 x 0.05) and / or (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05) the blue light-emitting phosphor at least one of the compounds ZnS: Ag, ZnS: Ag, Ga, ZnS : Ag, Cl and / or ZnS: Ag, Ga, Cl and the green light-emitting phosphor are at least one of the compounds InBO ₃ : Tb, Zn ₂ SiO ₄ : Mn and / or Zn ₂ SiO ₄ : Mn, As. 10. White light emitting phosphor according to An Proverb 9, the mixing ratio of the yellow light emitting phosphor, the blue light emitting Phosphor and the yellow light-emitting phosphor between 30 and 70% by weight, between 15 and 40% by weight and is between 15 and 30% by weight. 11. White light-emitting phosphor according to claim 10, wherein the amount of activator Sc added to the yellow light-emitting phosphor (Ca _1-x Mg _x ) S: Mn, Sc (0 x 0.05) is not greater than 300 ppm, based on the weight of the matrix (Ca _1-x Mg _x ) S. 12. White light emitting phosphor according to An Proverb 10, the light emitting the blue light substance ZnS: Ag, Ga or ZnS: Ag, Ga, Cl added amount of Activators Ga not larger than 100 ppm, based on the Ge important of the matrix ZnS, is.