JPS58120536A - Glass for panel of cathode ray tube - Google Patents

Abstract

PURPOSE:To provide titled glass which is difficult to be colored by irradiation of X-rays and electron rays by making the same consist of specific compsns. of SiO2, Al2O3, Li2O, Na2O, K2O, MgO, CaO, SrO, BaO, ZrO2, TiO2, Sb2O3, CeO2 and ZnO. CONSTITUTION:Raw materials of respective components consisting of 55-65% (by weight, hereinafter the same) SiO2, 0-4% Al2O3, 0.2-4% Li2O, 3-7% Na2O, 6-11% K2O, 0-4% MgO, 0-4% CaO, 6-12% SrO, 7.6-16% BaO, 0-1.9% ZrO2, 0.2-2% TiO2, 0-2% Sb2O3, 0.1-1% CeO2 and 0-1% ZnO are melted whereby the glass which has 670-710 deg.C softening point, 490-520 deg.C slow cooling point, 450-490 deg.C strain point, 95-105X10<-7> deg.C<-1> (0-300 deg.C) coefft. of thermal expansion and >=26.5cm<-1> X-ray absorptivity at 0.6Angstrom wavelength and is useful as a panel for color television tubes is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dark ray tube panel glass that is resistant to discoloration due to irradiation with X-rays and/or electron beams.

The panel glass for lt&ray tubes used in color televisions, flying spot tubes, projection tubes, etc.
It is necessary to sufficiently absorb the X iM generated in the pipe, so SrO, Bad, ZrO2 with high X & absorption ability
Karasu containing the following ingredients is used.

On the other hand, when exposed to X-rays for a long time, glass generally undergoes a coloring phenomenon called browning, resulting in a brown color and a decrease in transmittance. Browning caused by X-rays gradually recovers when irradiation is stopped, and almost completely recovers when heat is applied. However, browning due to the 1' rays also occurs at the same time, and the mechanism of browning due to this is different.Although the blue layer is about 10 μm from the surface, no fading occurs at all.
One object of the present invention is to provide a flannel crow having high resistance to the Browning effect caused by

The crow of the present invention has the following composition in terms of weight.

8102 55~65% All○l θ~4 Li x OO,2~' 4 NazO3~? 206~11 Mg0 O~4 Cao O~4 Sro6~12 BaO7,6~16 ZrOzO~3 T1020.2~2 Sb20B' O~2 CoOx '0.1~l ZnOO~1 S102 is a glass network former guess, 5
When it is less than 5%, the glass tends to devitrify and become unstable, and when it is more than 65%, the viscosity of the glass becomes too high, making melt molding difficult.

Al 20a is mainly used to improve the weather resistance of glass.
Contains up to 4%.

MgO and OaO are each contained up to 4% mainly to adjust the viscosity curve of the glass.

LizO, Nago, and 110 are contained as flux. L120 is contained at least 0.2% to improve the meltability of the glass, but if it exceeds 4%, the glass tends to devitrify. Preferably it is 0.5 to 1.5 inches.

NazO adjusts the viscosity of glass together with 20, improving melting, fining, and formability, and also increases the coefficient of thermal expansion of glass by 9.
In order to adjust the temperature to 5 to 105

K2O has the same effect as Nano, but Na20 is also more advantageous for browning with electron beams and contains at least 6% sb.

When it exceeds 11%, electrical characteristics deteriorate.

It is important to obtain a stable glass as a network modifier for 5rOi glass, and has high X-ray absorption ability, and contains 6 or more, but if it exceeds 12
This is not preferable because 5rSiOa crystals tend to precipitate and the liquidus temperature exceeds the molding temperature. Practically 8-10
A range of 1 is preferable.

BaO is also contained at 7.6% or more to improve the network modifier and L absorption performance of the glass, but if it exceeds 16%, the glass becomes unstable and
8101 crystals tend to precipitate. More preferably 7
．． It should be 6-12%.

Up to 3 Zr0ffi is contained in order to improve the X# absorption performance of the glass and to improve the weather resistance of the glass. However, when the temperature exceeds 3 degrees, the glass tends to devitrify. Preferably 0.5 to 2 inches.

0eC1 does not have much effect on preventing coloration from electron beams, but it has an excellent effect on preventing coloration from X-rays and ultraviolet rays.
It is necessary to add at least 0.1 h. Preferably 0.1
~0.5%. However, if it exceeds 1%, it is not economical and the glass will be colored, so it is not preferable.

5bzos is preferred as a glass fining agent and has a concentration of 0.5bzos.
It is recommended to add 2-0.7%. These also have the effect of preventing coloring due to electron beams. However, if it exceeds 1 inch, it is not preferable because the glass tends to be colored by electron beams, ultraviolet rays, and X-rays.

Since ZnO increases the X1w absorption coefficient of glass, 1
It can contain up to

TiO+ is 0 to prevent the glass from being colored by electron beams.
．． It is contained in a range of 2 to 2%.

In addition to the various components described above, Nip is used to reduce the transmittance of the glass or adjust the coloring.

Coloring components such as Coo, Fe2O's, MnO, and Cr2bs can be added in an amount of about 0.5 or less each according to a conventional method. However, the inclusion of PbO, AB20B, and B120s, which have an adverse effect on electron beam browning, should be avoided as much as possible.

Glass having the composition as described above is useful as a color television tube panel, but in this case, it is preferable to select a composition range and set the physical properties in the following range.

Softening point: 670-710°C, more preferably 690-7
05℃ Annealing point: 490-520℃, more preferably 500-5
20℃ strain point = 450~490℃, more preferably 460~
490°C Coefficient of thermal expansion = 95-105X10°C, preferably 7-1 98-100XIO°C (0-300°C) Within the above range, operations such as molding, sealing, and welding with metal can be easily performed. . Also, the X-ray absorption rate is at least 26.5Crn-1 at 0.6X wavelength, more preferably 28Crn-1.
rn or more.

In order to provide the above physical properties, a highly preferable composition is as follows: 1t (10
,5~2.5 Li20 0.5~1.5Na20
5-7 to 20 6-9BaO7,6-
12 Sr0 8 ~10Mg0
0.1~lCaO0,5~2 ZrOz O,5~20eOz
O,1~0.5Sb20g
0.2~07rtOz
,, 0.3-1 Examples Glass plates 1 and 2 of the present invention shown in the table were melted at 1450° C. by putting raw materials of each component into a platinum crucible according to the target composition. In order to obtain a homogeneous glass, the glass was stirred for 30 minutes with a stirring bar, and after defoaming, it was poured into a mold to prepare a test piece.

0,6 K wavelength teo'xlfg absorption coefficient (p
), thermal expansion coefficient (α) from 0 to 300°C, softening point, annealing point, and strain point are shown in the lower part of the table. A10 glass is currently commercially available glass for color television tube panels, and is shown for comparison.

A I A Z A 10 F 200 P 202 5000Sj
02 61.2 61.8
61.1AlzOa 2
．． 0 2.0 2. OBa○
8.0 8.0
5.7(aO1,81,81,8 Mg0O,40,40,4SrO9,5
9,59,7 ZrOz 1.1
1.1 2.5NazO6,06,08,l K2OB,0 7.0 7. ILi
zOO,81,2- TiOzO,40,40,
4SbzOa O,30,30
,3CeO20,50,50,2F --0,7tt
(cm-”) 28.5 28,4 2
8.8α (xlo/℃) 98,2 96,
9 98.2 Softening point (°C) 686 6°76 6
90 Annealing point ('C) 509 505 514 Strain
Point (℃) 469 466 474
X-ray Browning experiment The Xf# of each sample glass (AI, 2.10) and the spectral transmittance before irradiation were first measured, then the glass was irradiated with X-rays, and the glass was measured 2 minutes after irradiation and 24 hours later. The spectral transmittance was measured to examine the degree of coloration caused by irradiation.

A fluorescent Xk device was used as the X-ray irradiation source, and irradiation was performed from a chrome tube at 30 KV and 20 mA for 9 minutes.

The ratio of the spectral transmittance at each wavelength 2 minutes and 24 hours after irradiation to the spectral transmittance of the glass before irradiation (degree of recovery of the transmission bath) is shown in the table below.

The electron beam Browning experiment used KMX (electron micro probe mail analyzer) as the Doji brass irradiation source at 25KV.
The At-deposited sample glass was irradiated with a deuteron beam at a current density of 2.4×10 μA/d for 30 minutes with an O applied voltage. No coloration was observed in the samples of Notifications 1 and 2. On the other hand, light brown coloring was observed in the sample A10.

Proceedings [7-rE-I 1982 toV, >+1 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Patent Application for Indication of Case 1982-. 3260 No. 2, Name of the invention: Glass for cathode ray tube panels 3, Relationship with the amended and confusing case Patent applicant address: 2-1-2, Marunouchi, Chiyoda-ku, Tokyo Name
(o('+4) Asahi Glass Co., Ltd. 4, agent 5, voluntary amendment of the date of the amendment order, supplement + I ', supplement iE content 1, special code 1: request = 1 (supplement the range i'H as shown in the attached sheet.

2, N) Akira, ill+, Hai, page 3, line 14, "3" is corrected to rl, 9J.

(:') Details 1! ) “3” on page 5, lines 15 and 16
' to Q, 9J to Supplement I to 11mi)... (nil) for 1ri, IJF page 5, line 17, '2' to Q, 9
Correct to J.

(4) Correct "2" in the 8th line of the 8th page of the specification to ``rl, 9''.

Hereinafter, appended claims (1) Indicated by weight%, essentially 5 in 2
55-65% Al2O30-4 Li70 0.2-4 Na20. 3-7, C) 6~I+ Mgo O~4 CaOO~ 4 Sr0 6-12 BaO7,6-16 Z r O20~L, , 9 Ti07 0,2~2 sb, o, ' o~2 Ce07 0 Glass for cathode ray tube panels 5, which has ZnOO~ 1 and is not easily colored by X-ray and electron beam irradiation;

Claims (1)

[Claims] (1) In weight%, essentially the following composition SiO2
55-65 Al2O30-4 LizOO,2-4 Na20 3-7 20 6-11 Mg0, O-4 CaOO-4 Sr06-1.2BaO7,6-
16 Zr02 0 ~ 3 TiOz 0.2 ~ 281) 2011
0 to 20e020.1 to I Z n, o O to 1, and is resistant to coloring by X-ray and electron beam irradiation. Glass for cathode ray tube panels.