WO2007077680A1

WO2007077680A1 - Glass composition

Info

Publication number: WO2007077680A1
Application number: PCT/JP2006/322578
Authority: WO
Inventors: Jie Fu
Original assignee: Ohara Inc.
Priority date: 2005-12-28
Filing date: 2006-11-13
Publication date: 2007-07-12
Also published as: JPWO2007077680A1

Abstract

A radiation shielding glass free from lead component and containing rare earth oxides in large amounts that exhibits shielding capability comparable to that of lead glass and has high surface hardness, being extremely high in the transparency in visible region. There is provided a glass composition comprising more than 5% to 35%, by mass% on oxide basis, of the sum of Al2O3 and/or Ga2O3 and/or In2O3 and exhibiting a lead equivalent to 150 kV X-rays of 0.03 mmPb/mm or greater. The glass density can be increased by incorporating 20 to 90% of Ln2O3 (wherein Ln is at least one member selected from the group consisting of Y, La, Gd, Dy, Yb and Lu). Thus, there can be obtained a glass composition that has high radiation shielding capability and high surface hardness, being highly transparent in visible region.

Description

Specification

Glass composition

Technical field

[0001] The present invention relates to a glass composition, and more particularly, to a glass composition containing a large amount of a rare earth oxide.

Background art

[0002] In facilities that handle radiation such as X-rays and γ-rays, radiation shielding glass is used to facilitate work and to protect people engaged in work from radiation. Such glass is required to have high transparency in the visible range and excellent shielding ability (absorption ability) against radiation. Since the shielding ability is proportional to the mass absorption coefficient and density of glass, lead glass has been used for a long time.

However, since the lead component is a harmful substance, radiation shielding glass containing a large amount of the lead component needs to take measures for environmental measures when it is manufactured, processed, and disposed of. Had the problem of becoming higher. In addition, radiation shielding glass containing a large amount of lead components generates “scratches” on the glass surface after the surface has been cleaned in order to remove dirt on the glass surface. It has also become a problem that the performance is significantly reduced.

[0004] Further, since the surface hardness is low, the glass may be cracked due to scratches that are easily scratched on the surface in processing steps such as polishing and cutting.

[0005] Accordingly, radiation shielding glass containing no lead component has been developed. Patent Document 1 listed below is a SiO—BaO glass having essentially no lead component and having a density of 3 . 01

2

A radiation shielding glass of gZcm ³ or more is disclosed. Patent Document 2 below essentially contains no lead component, contains SiO and Al 2 O, and is suitable for lOOkV X-rays.

2 2 3

A radiation shielding glass having a lead equivalent of 0.03 mmPb / mm or more is disclosed. Patent Document 1: Japanese Patent Laid-Open No. 6-127973

Patent Document 2: Japanese Patent Laid-Open No. 2003-315489

Disclosure of the invention Problems to be solved by the invention

[0006] However, the radiation shielding glasses of Patent Documents 1 and 2 are limited to places where radiation with low energy is mainly handled because the shielding ability is much lower than that of lead glass.

[0007] The present invention has been made in view of the problems as described above, and has high radiation shielding in a glass system that does not contain a lead component and contains a large amount of rare earth oxides. Provided is a glass composition having performance.

Means for solving the problem

[0008] As a result of intensive studies to solve the above problems, the present inventor has found that Al O and

2 3 Z or G a O and / or In O, rare earth oxide Ln O (Ln is Y, La, Gd, Dy, Yb,

2 3 2 3 2 3

One or more selected from the group consisting of Lu. It has been found that a glass composition containing a large amount of) exhibits excellent radiation shielding ability similar to that of lead glass, and has a higher surface hardness and transparency than lead glass, and has led to the completion of the present invention. . More specifically, the present invention provides the following.

[0009] (1) The mass percentage of the oxide, and the combination of Al 2 O and Ga 2 O and O

2 3 Z

2 3 Z or In

2 3 Glass composition containing more than 5% and 35% weighing, and lead equivalent to 150kV X-ray is 0.03mmPb / mm or more.

[0010] According to this aspect, Al 2 O and

2 3 Z or Ga O and

2 3% of total amount of Z or In O is 5%

twenty three

By making it contain exceeding V, a glass composition with high surface strength can be easily provided. In addition, since the lead equivalent to 150 kV X-rays is 0.03 mmPb / mm or more, it can be suitably used even when handling high-energy radiation. Also, the total amount of Al 2 O and Z or Ga 2 O and Z or In 2 O exceeds 5%.

2 3 2 3 2 3

The rare earth oxide LnO (Ln is selected from the group consisting of Y, La, Gd, Dy, Yb, Lu)

twenty three

Indicates one or more. ) Can be contained in a larger amount, and the density of the glass can be increased.

[0011] (2) Ln O (Ln is the group consisting of Y, La, Gd, Dy, Yb, Lu)

twenty three

One or more selected from the above. ) In an amount of 20 to 85%.

[0012] The shielding ability of high-tech energy such as X-rays may be proportional to the density. Are known. According to the glass composition of the present invention, LnO (Ln is Y, La, Gd, Dy, Yb,

twenty three

One or more selected from the group consisting of Lu. )), The glass density can be increased, so that a high radiation shielding ability can be easily obtained.

[0013] (3)% by mass based on oxide, SiO and / or B 2 O and

2 Z 2 3 Z or GeO and

2 Total amount of Z or PO is 5 to 70%, ZnO is 0 to 25%, RO is 0 to 10% (R is Ba, Sr, C

twenty five

1 or more selected from the group consisting of a and Mg. ), Rn O 0-10% (Rn is Li, Na

2

One or more selected from the group consisting of, K, Cs. ), The total amount of Sb O and As O

2 3 2 3

The glass composition according to (1) or (2), which contains each component in the range of 0 to 5%.

[0014] According to this embodiment, SiO and

2 Z or B O and

2 3 Z or GeO and

2 Z or P O

2

ZnO, RO (R represents at least one selected from the group consisting of Ba, Sr, Ca, Mg), Rn

Five

0 (Rn represents one or more selected from the group consisting of Li, Na, K, and Cs).

2

Therefore, the glass composition is excellent in meltability of glass, stable against devitrification and having high surface strength, and can easily be produced.

[0015] (4) Containing 0 to 10% Ce 2 O in terms of mass% based on oxide (1) to (3)

twenty three

The glass composition as described.

[0016] According to this aspect, Ce 2 O is a component that contributes to improving the radiation shielding ability,

twenty three

In addition, it is a component having an effect of preventing coloring due to irradiation of radiation. Therefore, a glass composition having transparency in glass can be easily provided even when used for a long period of time.

[0017] (5) Containing 0 to 15% of TiO in mass% based on acid oxide, (1) to (4)

2

The glass composition as described.

[0018] According to this aspect, TiO is a component having an effect of improving the surface hardness of glass.

2

Thus, a glass composition having a high glass surface hardness can be easily provided.

[0019] (6) Mass% based on oxide, one or two of ZrO, SnO, NbO, TaO, WO

2 2 2 5 2 5 3

The glass composition according to any one of (1) to (5), containing a total of 0 to 30% of seeds or more.

[0020] According to this aspect, since the above components are effective in improving the radiation shielding ability and the surface hardness of the glass, the glass composition containing the above components is suitable as a radiation shielding glass. Used for.

[0021] (7) The glass composition according to any one of (1) to (6), wherein the density is 3.2 gZcm ³ or more.

[0022] According to this aspect, since the density is 3.2 gZcm ³ or more, it is easy to obtain a high radiation shielding ability.

[0023] (8) In the glass composition having a thickness of 10 mm, the transmittance at a wavelength of 400 nm is 0% or more, and the transmittance at a wavelength of 550 nm is 80% or more. Glass composition.

[0024] According to this aspect, since the transmittance power at a wavelength of 400 nm is 0% or more and the transmittance at a wavelength of 550 nm is 80% or more, X-rays, γ-rays, etc. have high transparency in the visible region. It is possible to easily provide a glass composition that allows easy observation of the inside of a facility or the like when used as a shield for facilities that handle radiation.

[0025] (9) The glass composition according to any one of (1) to (8), having a Knoop hardness of 500 NZmm ² or more.

[0026] According to this aspect, since the Knoop hardness (HK) is 500 NZmm ² or more, it is possible to easily provide a glass composition having high mechanical strength that hardly damages the glass surface.

[0027] (10) A radiation shielding glass which is the glass composition according to any one of (1) to (9).

[0028] According to this aspect, the glass composition has an excellent radiation shielding ability with a lead equivalent to 150 kV X-rays of 0.03 mmPbZmm or more, and has high transparency in the visible range and excellent transparency. Since the surface hardness is also high, it is more suitable as a radiation shielding glass.

The invention's effect

[0029] The glass composition of the present invention comprises, as glass components, Al 2 O and

2 3 Z or Ga O and

Since the total amount of 2 3 Z or In O exceeds 5%, the surface strength of the glass increases.

twenty three

Rare earth oxide Ln O (Ln is one selected from the group consisting of Y, La, Gd, Dy, Yb, Lu)

twenty three

The above is shown. )) In a larger amount, it is possible to easily increase the density of the glass and increase the lead equivalent, and even if it does not contain a lead component, it is comparable to a glass containing a lead component. It is possible to provide a glass composition having a radiation shielding ability.

Brief Description of Drawings FIG. 1 is a diagram showing a spectral transmittance curve in the glass composition of Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

[0031] Next, specific embodiments of the glass composition of the present invention will be described.

[0032] [Glass component]

The composition range of each component which comprises the glass composition of this invention is described below. In the present specification, unless otherwise specified, the content of each component is described in mass% (also referred to as wt%). In the specification of the present application, all the glass compositions represented by mass% are represented by mass% on the basis of oxides. Here, the “oxide standard” means that the oxide, nitrate, etc. used as a raw material of the glass component of the present invention are all decomposed and changed into oxides when melted, and the mass of the generated oxides. This is a composition in which each component contained in the glass is described with the total of 100% by mass.

[0033] <Essential and optional ingredients>

The components of Al O and Z or Ga O and Z or In O are responsible for the meltability and stability of the glass.

2 3 2 3 2 3

This is effective in improving the hardness of the glass and also in improving the hardness of the glass surface. Al O

2 3 and Z or Ga O and

2 3 By adding Z or In O component, more Ln O component

It is possible to incorporate 2 3 2 3 minutes into the glass, and as a result, the density of the glass is improved and the radiation shielding ability tends to be higher. In order to obtain the above effects, the total amount needs to exceed 5%, but if it exceeds 35%, the stability of the glass is likely to be greatly impaired. Accordingly, the preferable range of the total content is 5% as a lower limit, and the upper limit is 35%, more preferably 30%, and most preferably 25%. Of these components, the Al O component is particularly effective.

twenty three

Large, so it is preferable to contain more than 5%.

[0034] Ln O component (Ln represents one or more selected from the group consisting of Y, La, Gd, Dy, Yb, Lu)

twenty three

The ) Is a component useful for achieving the object of the present invention because it increases the density of the glass and imparts a high radiation shielding ability to the glass. However, it contains excessive Ln O component

twenty three

Then, if the stability of the glass is easily impaired and too small, it becomes difficult to satisfy the object of the present invention. Therefore, the lower limit of the amount of LnO is 20%, more preferably 26%, and most preferably 35%.

twenty three

The upper limit is preferably 85%, more preferably 80%, and most preferably 75%. Of the L n O components, especially Gd O and Lu O components are more effective, so either or It is preferable to include both.

[0035] The components of SiO and Z or B 2 O and Z or GeO and Z or PO are glass

2 2 3 2 2 5

It is a useful oxide for forming highly transparent glass with devitrification. However, if the content is too high, the radiation shielding ability of the glass tends to decrease, and if it is too low, the stability of the glass decreases. easy. Therefore, the lower limit of the total amount is 5%, more preferably 8%, and the upper limit is preferably 70%, more preferably 65%.

[0036] The components of SiO and B 2 O are glass-forming oxides, which are small enough to easily obtain a stable glass.

2 2 3

It is preferable that at least one of them is included. In order to obtain a stable glass, the lower limit of the total content of these components is preferably 5%, more preferably 8%, and most preferably 10%. Also, if the content of these components is too large, the radiation shielding ability tends to decrease. Therefore, in order to obtain a high radiation shielding ability, the upper limit of the content is preferably set to 70%, preferably 60%. Most preferred is 55%.

[0037] The components of SiO and B 2 O can achieve the object of the present invention even when introduced alone into glass.

2 2 3

However, the simultaneous use improves the meltability, stability and chemical durability of the glass.

[0038] Since the GeO component functions in the same manner as the SiO component, a part or all of the SiO component is removed.

2 2 2

Since the power that can be replaced is expensive, the upper limit is preferably 30% or less, more preferably 20% or less, and most preferably 15% or less.

[0039] Since the P 2 O component functions in the same manner as the SiO or B 2 O component, SiO or B 2 O

It is possible to replace some or all of the components of 2 5 2 2 3 2 2 3. However, if the amount is too large, the glass phase separation tendency becomes strong. Therefore, it is most preferable to set the upper limit value to 20%, preferably 10%, and more preferably 5%.

[0040] The ZnO component is an effective component for improving the meltability, stability, and chemical durability of the glass. However, if the amount is too large, devitrification is likely to occur and the radiation shielding ability is also reduced. Easy to do. Therefore, it is most preferable to set the upper limit to 25%, preferably 15%, and more preferably 10%.

[0041] RO component (R represents one or more selected from the group consisting of Ba, Sr, Ca, Mg) is a component that is effective in improving the melting and stability of glass. Too much and glass It is easy to reduce the stability. Therefore, the upper limit of the total amount is preferably 10%, more preferably 8%, and most preferably 5%. Of the RO components, the BaO component and the SrO component are particularly important because they are effective in improving the radiation shielding ability, which is the object of the present invention, in addition to the above effects.

[0042] The BaO component is effective in improving the meltability, stability and radiation shielding ability of the glass, but if the amount is too large, the stability of the glass tends to be lowered. Therefore, it is most preferable to set the upper limit value to 10%, preferably 8%, and more preferably 5%.

[0043] The SrO component is effective in improving the meltability, stability and radiation shielding ability of the glass, but if the amount is too large, the stability of the glass will be lowered. Therefore, it is most preferable to set the upper limit value to 10%, preferably 8%, and more preferably 5%.

[0044] The CaO component is an effective component for improving the meltability of the glass. However, if the amount is too large, devitrification is likely to occur, and the radiation shielding ability tends to be lowered. Therefore, it is most preferable to set the upper limit to 5%, preferably 3%, and more preferably 1%.

[0045] The MgO component is an effective component for improving the meltability of the glass. If the amount is too large, devitrification tends to occur, and the radiation shielding ability tends to decrease. Accordingly, it is most preferable to set the upper limit value to 5%, preferably 3%, and more preferably 1%.

[0046] The Rn O component (Rn represents one or more selected from the group consisting of Li, Na, K, and Cs.)

2

This component is effective in improving the meltability and stability of the lath and is also effective in preventing coloring due to irradiation. However, if the amount is too large, the stability of the glass tends to deteriorate.

The radiation shielding ability is also likely to be greatly reduced. Therefore, it is most preferable to set the upper limit of the total amount to 10%, preferably 5%, more preferably 3%. Rn O

Combining two or more of 2 minutes can produce a great effect by preventing coloring caused by irradiation.

[0047] The Li O component is a component that improves the meltability of the glass, but if the amount is too large, devitrification

2

Is likely to occur, and the radiation shielding ability is likely to be reduced. Therefore, it is most preferable to set the upper limit value to 10%, preferably 5%, more preferably 3%.

[0048] The Na 2 O component is a component that improves the meltability of the glass. Permeability is likely to occur, and the radiation shielding ability is likely to decrease. Therefore, the upper limit is 10%, and 5% is more preferable, and 3% is most preferable.

[0049] The K 2 O component is a component that improves the meltability of the glass.

2

Is likely to occur, and the radiation shielding ability is likely to be reduced. Therefore, it is most preferable to set the upper limit value to 10%, more preferably 8%, and more preferably 5%.

[0050] The Cs O component improves the meltability of the glass and contributes to the improvement of radiation shielding ability.

2

However, if the amount is too large, devitrification tends to occur. Therefore, it is most preferable to set the upper limit value to 10%, preferably 8%, and more preferably 5%.

[0051] The components of Sb 2 O and As 2 O can be optionally added for glass melting defoaming

2 3 2 3

It is an ingredient. The total amount of Sb 2 O and As 2 O is sufficiently effective at 5% or less. Also,

2 3 2 3

As O component does not take environmental measures when manufacturing, processing and disposing of glass

twenty three

It is necessary to Therefore, it is preferable to set the upper limit to 5% with the total amount of SbO and AsO.

2 3 2 3

It is most preferable to set it to 3%, more preferably 1%.

[0052] The Ce O component is a component that has an effect of preventing coloring due to irradiation of radiation. Optional

twenty three

Although it is a component that can be added, if the amount is too large, the absorption edge of the glass shifts to the longer wavelength side, which may lead to a decrease in transparency in the visible region. Therefore, the upper limit is preferably 10% or less, more preferably 3% or less, and most preferably 1% or less.

[0053] The TiO component is a component effective in improving the stability of the glass and the hardness of the surface. Any

2

Power that is a component that can be added to the glass If the amount is too large, the stability of the glass tends to be low. Therefore, 15% or less is preferable, 10% or less is more preferable, and 5% or less is more preferable.

[0054] The ZrO component is a component effective in improving the radiation shielding ability and the surface hardness of the glass.

2

The Although it is a component that can be optionally added, if the amount is too large, the stability of the glass is easily lowered. Therefore, it is most preferable to set the upper limit to 20%, preferably 15%, more preferably 10%.

[0055] The SnO component is an optional component effective in improving the radiation shielding ability.

2

If the amount is too large, the stability of the glass tends to be lowered. Therefore, the upper limit should be 15%. The preferred value is 10%, and the most preferred value is 5%.

[0056] The Nb 2 O component is a component that is effective in improving the radiation shielding ability. Add arbitrarily

twenty five

However, if the amount is too large, the stability of the glass tends to decrease, so 20% or less is preferred and 15% or less is more preferred and 10% or less is more preferred. Most preferably.

[0057] The Ta O component is a component that is effective in improving the radiation shielding ability. Add arbitrarily

twenty five

However, if the amount is too large, the stability of the glass tends to be lowered. Therefore, it is most preferable to set the upper limit value to 20%, preferably 15%, and more preferably 10%.

[0058] The WO component is a component that is effective in improving the radiation shielding ability. Add arbitrarily

Three

However, if the amount is too large, the stability of the glass tends to decrease, so 25% or less is preferred and 20% or less is more preferred and 15% or less. Most preferably.

[0059] In order to further improve the stability of the glass, ZrO, SnO, NbO, TaO, WO

It is preferable to set the upper limit of the total amount of one or more of 2 2 2 5 2 5 3 to 30%, preferably 20%, and most preferably 10%. Furthermore, of these ingredients, ZrO and

2

Since the WO component is more effective in improving chemical durability, either force or both

Three

It is preferable to contain them simultaneously.

[0060] <About ingredients that should not be included>

Other components can be added as needed within the range without impairing the properties of the glass composition of the present invention. However, glass is colored even when transition metal components such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo other than Ti are contained alone or in combination in small amounts. Causes absorption at specific wavelengths in the visible range. Therefore, it is preferable that the glass composition of the present invention does not contain substantially. “Substantially free” as used herein means that it is not contained artificially unless it is mixed as an impurity.

[0061] The components of Pb, Th, Cd, Tl, and Os have tended to be refrained from being used as harmful chemical substances in recent years. Until then, environmental measures are required. Therefore, if the environmental impact is important, Qualitatively preferred.

[0062] Further, the glass composition of the present invention can have a density of 3.2 gZcm ³ or more.

. A more preferable density range is 3.3 gZcm ³ or more.

[0063] The glass composition of the present invention is a glass composition having a thickness of 10 mm that is highly transparent in the visible region! /, And has a transmittance of 0% or more at 400 nm and a transmittance of 80% or less at 550 nm. Above.

In addition, the glass composition of the present invention has a Knoop hardness (HK) of 500 NZmm ² or more, more preferably 550 NZmm ² , and most preferably 600 NZmm ² .

In the present invention, the radiation shielding ability is represented by lead equivalent. The lead equivalent is expressed by the thickness of the lead plate with the same X-ray shielding ability. The larger this value, the better the radiation shielding ability. Regarding the glass composition of the present invention, the lead equivalent for 150 kV X-rays was determined by converting the lead equivalent measured by a method according to JIS4501 to a thickness of 1 mm. The lead equivalent of the glass composition of the present invention is preferably 0.03 mmPb / mm or more, more preferably 0.05 mmPb / mm or more.

[0066] Thus, the glass composition of the present invention has a lead equivalent to 150 kV of X-rays of 0.03 mm PbZmm or more, and is highly transparent in the visible region at a thickness of 10 mm at 400 nm. With a transmittance of 0% or more, a transmittance at 550 nm of 80% or more, and a Knoop hardness of 500 NZmm ² or more, it is suitable as a radiation shielding glass with high radiation shielding ability and excellent transparency. And

[0067] [Production method]

The glass composition of the present invention is not particularly limited as long as it is a method for producing ordinary glass, but can be produced, for example, by the following method. Weigh out a predetermined amount of each starting material (oxide, carbonate, nitrate, phosphate, sulfate, fluoride salt, etc.) and mix uniformly. The mixed raw materials are put into a quartz crucible, alumina crucible, platinum crucible, platinum alloy crucible or iridium crucible and melted at 1100-1550 ° C for 1-10 hours in a melting furnace. Then, after stirring and homogenizing, the temperature is lowered to an appropriate temperature and placed in a mold or the like to produce glass.

Example

[0068] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. It is not limited to the following examples.

[0069] <Examples 1 to 14>

The starting materials are weighed with the compositions of Examples 1 to 14 shown in Tables 1 and 2 (unit: wt%), mixed uniformly, and then placed in a platinum crucible and melted at 1300-1500 ° C for 2-4 hours. Then, it was poured into a mold and glass was produced.

[0070] <Comparative Example 1>

As a comparative example, a lead-containing glass used as a radiation shielding glass was produced.

[0071] A batch was prepared so as to have the composition of Comparative Example 1 shown in Table 2. First, a cullet was prepared by melting at 1300 ° C for 1 hour and 20 minutes using a quartz crucible. Thereafter, the cullet was put in a platinum crucible and melted at 1320 ° C for 2 hours and 30 minutes, and then poured into a mold to produce glass.

[0072] Tables 1 and 2 show the density, transparency, Knoop hardness, and lead equivalent of Examples 1 to 14 and Comparative Example 1.

The density was measured by the Archimedes method. The transmittance was measured according to the Japan Optical Glass Industry Association Standard JOGIS02. In the present invention, the transmittance is shown not the coloring degree. Specifically, a spectral transmittance of 200 to 800 nm was measured for a face-parallel polished product having a thickness of 10 ± 0.1 mm according to JISZ8722. The transmittance T at wavelengths of 400 nm and 550 nm was determined and used as an index representing the transparency of the present invention. Knoop hardness (HK) was measured in accordance with JOGIS09 standard of Japan Optical Glass Industry Association. The lead equivalent was measured at a tube voltage of 150 kV according to JISZ4501.

[0073] [Table 1]

Actual §Example

1 2 3 4 5 6 7 8

Si0 ₂ 13.7 10.8 13.1 13.4 14,5 17.2 4.3 13.6

B ₂ 0 ₃ 15.8 16.1 6.5 6.7 16.8 20.0 8.2 15.8

Ge0 ₂ one - - - - - 0.5 -. 2O ₅ - - - A - A 3.4 one

PbO 1-1-1-

Al ₂ 0 ₃ 15.4 12.0 12.7 13.0 16.4 19.5 ― 11.5

Ga ₂ 0 ₃ ― ― ― ― ― 12.8 ―

Single ZnO ― ― ― ― ― 0.61

BaO 1 7.0 ― ― ― ― ― ―

SrO One 1.0 ― ― ― One ― ―

K ₂ 0 One ― ― One ― ― 1.7

Na ₂ 0 One ― ― ― ― ― ― 0.7

Li ₂ 0 ― ― One ― ― One One ―

Ti0 ₂ ― ― 1 ― 1 ― 0,3

Zr0 ₂ 1---1 1 1 0.3

Y ₂ 0 ₃ One ― One ― ― 43.2 5.4 ― and a ₂ 0 ₃ 5.0 One ― 20.8 52.4 ― 7.7 One

Gd ₂ 0 ₃ 55.0 53.0 67.7 46.2 ― ― 34.4 54.4 and u ₂ 0 ₃ Same ― ― ― 18.9 ―

W0 ₃ ― ― ― ― ― ― ― 0.4

Nb ₂ 0 ₅ ― ― ― ― ― ― One 0.6

Ta ₂ 0 ₅ ― ― ― ― ― One 0.6

Ce ₂ 0 ₃ ― ― ― ― One ― One 0.2

Sb ₂ 0 ₃ 0.1 One ― ― One ― ―

As ₂ 0 ₃ ― 0.1 ― ― ― One ― ― Density

4.21 4.46 5.09 4.90 3.86 3.38 5.80 4.22

(g / cm ³ )

Knoop hardness

660 610 690 680 630 660 700 670

(N / mm ² )

87/82 86/79 82/68 85/74 87/82 85/79 82/65 86/80 Lead equivalent

0.17 0.19 0.22 0.21 0.12 0.05 0.25 0.17

(mmPb / mm)

*

Indicates transmittance at a wavelength of 550 nm / transmittance at a wavelength of 400 nm. 2] Actual example Comparison example

9 10 11 12 13 14 1

Si0 ₂ 17.0 20.5 11.8 10.0 10.0 10.2 35.4

B ₂ 0 ₃ 7.4 7.9 8.2 11.6 12.1 12.2 ―

Ge0 ₂ ― ― —— ― ― — —

P ₂ O ₅ One ― ― One ― ― ―

PbO ― ― ― ― ― ― 58.0

Al ₂ 0 ₃ 14.4 11.6 10.7 6.8 5.3 5.5 ―

Ga ₂ 0 ₃ ― ― ― One ― ― ―

ZnO ― ― 1.6 4.3 4.8 4.4 ―

BaO ― ― ― ― ― ― ― BaO

SrO ― One ― ― ― One ―

K ₂ 0 ― ― ― ― One 0.1 1.8

Na ₂ 0 One ― One ― ― 0.3 1.8

Li ₂ 0 ― ― ― ― ― 0.2 ―

Ti0 ₂ ― One ― ― ― One 3.1

Zr0 ₂ 1.8 4.7 4.0 2.5 2.9 1.7 ―

Y ₂ 0 ₃ One One ― One One One One

La ₂ 0 ₃ ― ― 12.8 13.0 13.0 13.2

Gd ₂ 0 ₃ 59.0 54.9 47.5 43.5 43.6 44.1 One

U ₂ 0 ₃ 1 ― ― ― ― ― wo ₃ ― ― 3.0 7.7 7.7 7.8 1

Nb ₂ 0 ₅ One ― One ― ― ― ―

Ta ₂ 0 ₅ One ― ― One ― ― ―

Ce ₂ 0 ₃ ― One ― ― ― ― ―

Sb ₂ 0 ₃ 0.4 0.4 0.4 0.6 0.6 0.3 ―

As ₂ 0 ₃ ― ― ― ― ― ― ― Density

4.60 4.45 4.97 5.00 5.05 5.04 4.33

(g / cm ³ )

Knoop hardness

670 670 670 670 680 670 390

(N / mm ² )

T / Τ9ΐ) _400πΓΙ1 85/80 85/80 85/76 85/66 85/66 85/68 85/50

Lead equivalent

0.19 0.18 0.21 0.22 0.23 0.23 0.20

*

Indicates transmittance at a wavelength of 550 nm / transmittance at a wavelength of 400 nm. FIG. 1 shows the spectral transmittance curve of the glass composition of Example 1. The horizontal axis represents wavelength (nm) and the vertical axis represents spectral transmittance (%). These transmittances include reflection loss. As shown in FIG. 1, it can be seen that the glass composition of the present invention has extremely high transparency over the entire visible range. Moreover, as seen in Tables 1 and 2, the glass composition of the present invention has a greater transparency than existing lead glass. [0076] According to Tables 1 and 2, it can be seen that the surface hardness (Knoop hardness) of the glass composition of the present invention is 1.5 times higher than that of lead glass.

[0077] According to Tables 1 and 2, the glass composition of the present invention has a high lead equivalent and has a radiation shielding ability equivalent to or higher than that of lead glass.

Claims

The scope of the claims

[1]% by mass based on oxide, Al 2 O and

2 3 Z or Ga O and

2 3 Total amount of Z or In O

Glass and composites containing more than 5% and 35% of 2 3 and lead equivalent to 150kV X-ray is 0.03mmPbZmm or more.

[2] Oxide-based mass%, Ln O (Ln is selected from the group consisting of Y, La, Gd, Dy, Yb, Lu)

twenty three

Indicates one or more selected. 2) The glass composition according to claim 1, comprising 20 to 85%.

[3]% by mass on oxide basis, SiO and Z or B 2 O and eO and

2 3 Z or G

2 2 The total amount of Z or PO is 5 to 70%, ZnO is 0 to 25%, RO is 0 to 10% (R is Ba, Sr, Ca,

twenty five

One or more selected from the group consisting of Mg. ), Rn O 0-10% (Rn is Li, Na, K

2

, One or more selected from the group consisting of Cs. ), The total amount of Sb O and As O is 0 ~

2 3 2 3

The glass composition according to claim 1 or 2, comprising each component in a range of 5%.

[4] The content according to any one of claims 1 to 3, wherein CeO is contained in an amount of 0% by mass based on oxide.

twenty three

Glass composition.

[5] The composition according to any one of claims 1 to 4, wherein 0 to 15% of TiO is contained by mass% based on the oxide.

2

Glass composition.

[6]% by mass based on oxide, one or more of ZrO, SnO, NbO, TaO, WO

2 2 2 5 2 5 3

The glass composition according to any one of claims 1 to 5, which contains a total of 0 to 30% of the above.

7. The glass composition according to any one of claims 1 to 6, wherein the density is 3.2 gZcm ³ or more.

[8] In the glass composition having a thickness of 10 mm, the transmittance force at a wavelength of 400 nm is 0.

The glass composition according to any one of claims 1 to 7, wherein the transmittance at a wavelength of 550 nm is 80% or more.

[9] The glass composition according to any one of claims 1 to 81 /, wherein the Knoop hardness is 500 NZmm ² or more.

[10] A radiation shielding glass which is the glass composition according to any one of claims 1 to 9.