JP2001019470A - Glass with dark gray color - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass with a dark gray color having relatively low transmittance for visible rays, keeping proper transparency and privacy protection property, having proper shielding property against UV rays and sun rays, easily fused as a glass, and suitable for a vehicle such as an automobile, window glass of a transportation instrument, window glass for building, or the like. SOLUTION: The glass has the basic composition of soda lime silica glass and contains as coloring components, by wt.%, 0.3 to 0.8 of Fe2O3 (all iron), 0.06 to 0.18 of FeO, 0.0050 to <0.0140 of CoO, 0.0030 to 0.0200 of Cr2O3, and 0.0005 to 0.0025 of Se with 0.2 to 0.3 ratio of divalent iron ion to the all iron ions (Fe2+/Fe2++Fe3+)). The glass has such optical characteristics as 35 to 55 % transmittance for visible rays, 35 to 60% transmittance for sun rays and <=25% transmittance for UV rays for a 3.5-mm thick glass sheet, satisfying (transmittance for visible rays) <=(transmittance for sun rays), the main wavelength ranging from 480 to 580 nm for a D-light source, and <=4% excitation purity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gray color having a relatively low visible light transmittance and a uniform color tone, having both a solar absorption performance and an ultraviolet absorption performance, and having an appropriate transparency and privacy. , Architectural glazing and automobiles,
The present invention relates to a dark gray glass useful as a window glass for transportation equipment such as ships and aircraft.

[0002]

2. Description of the Related Art In recent years, various dark-colored glasses having a low visible light transmittance such as a dark green color or a dark bronze color have been proposed. It focuses on the gentle dark gray color.

[0003] Known examples of dark gray (gray) glass, for example, in Kokoku 6-49593 discloses includes _{Fe 2 O 3, Se, CoO} , the Cr ₂ O ₃ as a coloring agent, glass thickness 5.56m
A neutral gray low transmission glass composition having a visible light transmission of less than 20% at m. The known example has a high Se and Cr ₂ O ₃ content and a visible light transmittance of 5.56 mm (0.219 in).
It is as low as 20% or less, and cannot be satisfied in cases where transparency is desired.

For example, Japanese Patent Application Laid-Open No. 2-64038 discloses that
A dark, light gray, nickel-free glass composition is described, which contains Fe ₂ O ₃ , Se, and CoO as colorants, but still has a glass thickness of 5.56 mm and a visible light transmittance of 20% or less. Low.

Further, for example, Japanese Patent Publication No. Hei 6-503300 discloses that
Although the glass contains Fe ₂ O ₃ , CoO, Se, and Cr ₂ O ₃ (the above two are optional components) as coloring components, the solar transmittance is lower than the visible light transmittance. The glass whose absorption in the infrared region (heat ray) is increased particularly by lowering the solar radiation transmittance. However, in this case, heat is hardly transmitted to the lower layer of the glass layer when the glass is melted, and there is a problem in homogenization and fining.

JP-A-6-247740 filed by the present applicant
In the publication, Fe ₂ O ₃ , CoO, Se, and Cr
A deep gray glass containing ₂ O ₃ , TiO ₂ , and NiO (the above three are optional components) is disclosed. In the known example, CoO is 1
It is necessary that the content be 40 ppm or more, but within the above range, the optical characteristics as in the present invention, particularly the visible light transmittance, cannot be obtained.

According to the present invention, the color tone is not biased, and it is a dark gray color which is gentle visually, and has a visible light transmittance of about 30 to 50% (3.5 mm thickness) while maintaining a moderate privacy. It is an object of the present invention to provide a dark gray color glass which has transparency and higher solar radiation transmittance than visible light transmittance, and thus has heat ray transmittance and is easy to melt.

[0008]

According to the present invention, a soda-lime-silica glass is used as a base composition, and a coloring component is represented by wt%.
Fe ₂ O ₃ (total iron) 0.3-0.8, FeO 0.06-0.18, CoO 0.0050
~ <0.0140, Cr ₂ O ₃ 0.0030-0.0200, Se 0.0005-0.002
5 range and the ratio of divalent iron ion to total iron ions ^{(Fe 2+ / (Fe 2+ +} Fe 3+)) has a component composition comprising a range of 0.2 to 0.3, the visible in the glass plate thickness 3.5mm Light transmittance is 3
5-55%, solar transmittance 35-60%, UV transmittance 25%
A dark gray color glass characterized by having visible light transmittance ≦ solar transmittance, the dominant wavelength according to the D light source being 480 to 580 nm, and having an excitation purity of 4% or less. is there. In the CoO, 0.0050 to <0.
The indication of 0140 (wt%) indicates that the content is 0.0050 wt% or more and less than 0.0140 wt%.

[0009]

Soda-lime-silica based glass in the Detailed Description of the Invention The present _{invention, SiO 2 68 ~73wt%, Al} 2 O 3 0~3wt%, MgO
0~5wt%, CaO 5~12wt%, Na 2 O 10~15wt%, K 2 O
It is in the range of about 0 to 3% by weight, which is about the same level as that of ordinary soda-lime-silica glass, and is excellent in terms of glass meltability, moldability, mass productivity, water resistance and weather resistance of glass products. .

In the present invention, desired optical characteristics are obtained by equilibrating the respective coloring components in the glass in the following ranges.

[0011] Fe ₂ O ₃ (total iron) is a main component for appropriately reducing the transmittance of ultraviolet rays, visible light, and solar radiation by trivalent and divalent Fe ions. Range. If the content is less than 0.3 wt%, the above-mentioned effect cannot be sufficiently exerted.
%, The visible light transmittance is too low, and the transparency is impaired. Preferably, it is in the range of 0.4 to 0.7 wt%.

The content of FeO is in the range of 0.06 to 0.18 wt%. Although it is closely related to other coloring components, if it is less than 0.06% by weight, the absorption in the infrared region becomes weak. If it exceeds 0.18 wt%, relatively Fe ₂ O
₃ (trivalent iron) is reduced, and the ultraviolet absorption performance is reduced. When the upper limit of FeO exceeds 0.18 wt%, the absorption of infrared rays (heat rays) improves,
In the melting method in which the glass layer is melted, homogenized, and clarified by a flame from above in a normal glass kiln, heat is difficult to be transmitted to the lower layer of the glass layer, and homogeneity, clarity is easily damaged, or productivity is easily reduced. The problem is solved by controlling the content to 0.18 wt%. FeO is more preferably in the range of 0.08 to 0.16 wt%.

The ratio of ferrous ions in iron ions: Fe ²⁺ /
(Fe ²⁺ + Fe ³⁺ ) is to be 0.2 to 0.3, and in connection with the above, if outside the above range, the absorption in the infrared or ultraviolet region is weakened, and the color tone becomes yellowish or bluish,
It is difficult to obtain a desired dark gray color.

CoO absorbs light having a wavelength of 550 to 650 nm, and when CoO is used alone, the glass is colored blue. However, together with the above-mentioned Fe ₂ O ₃ , the glass contains 0.0050 wt% or more and less than 0.0140 wt%. By coexisting, the transmittance curve is flattened, and the color tone is gray without bias. If it is less than 0.0050 wt%, its effect is small, and if it is 0.0140 wt% or more, it becomes bluish, or if other coloring components are adjusted to obtain a gray color, it becomes difficult to obtain the expected visible light transmittance. Preferably 0.
0080 to 0.0120 wt%.

Cr ₂ O ₃ absorbs light at wavelengths of around 450 nm and around 650 nm, and further stabilizes the gray color by coexisting with Fe ₂ O ₃ and CoO. It is contained in the glass in the range of 0.0030 to 0.0200 wt%. 0.0030wt
% Or less than 0.0200 wt%, the effect is small, and it is difficult to obtain a desired gray color.

Se mainly absorbs light at a wavelength of 490 nm, but coexists with the above-mentioned Fe ₂ O ₃ , CoO, and Cr ₂ O _3, and has a content of 0.0005 to 0.002.
A desired gray color tone is obtained by containing 5 wt%, and if the content is out of the above range, the color tone becomes reddish or bluish and it is difficult to obtain a desired color tone. More preferably, it is in the range of 0.0010 to 0.0020 wt%.

As a fining agent, a sulfate such as Na ₂ S
O ₄ , the sulfur content to be introduced in the form of CaSO ₄ (SO ₃ ) also acts as an oxidizing agent, and is designed and introduced in order to set the ratio of ferrous ions to the appropriate range, that is, 0.10 to 0.20. Alternatively, the oxygen concentration in the atmosphere may be designed, and these are design items as appropriate.

[0018] In addition, a small amount of impurity component may be mixed from raw materials used such as MnO, ZnO, TiO ₂ , CeO ₂ or cullet. However, there is no problem if the total amount of these is 0.1 wt% or less.

Further, as measured by illuminant D _65, a main wavelength region obtained by way of a 480～580Nm, if the range can be obtained dark gray colored glass of almost expected color tone. Of course, the stimulus purity is also very important in obtaining a gray color, and it is preferable that the stimulus purity be 4% or less.

The UV transmittance at a standard plate thickness of 3.5 mm is 2
By setting the content to 5% or less, the effect on the human body and the fading of the coloring material can be suppressed as much as possible.

The visible light transmittance at a plate thickness of 3.5 mm is 3
If it exceeds 55%, it is difficult to obtain good privacy, and if it is less than 35%, the transparency is impaired. However, 35% or more is required for clear visual recognition through the rear window.

Further, the solar radiation transmittance at a plate thickness of 3.5 mm is 35
Up to 60%, and the solar radiation transmittance is higher than the visible light transmittance. By reducing the solar radiation transmittance to 60% or less, the solar radiation infrared rays are cut off as much as possible, for example, the cooling load in summer is effectively reduced. it can. Further, although it is related to the FeO content, the solar radiation transmittance is 35% or more and higher than the visible light transmittance, that is, by suppressing absorption in the infrared region (heat ray), it is possible to increase the normal upward temperature during glass melting. In the heating and melting method of the glass layer by the flame from the glass, the heating to the lower layer of the glass layer and the soaking are facilitated.

Incidentally, the visible light transmittance and the solar transmittance are JI
S R3106, UV transmittance measured according to ISO / DIS-9050,
The dominant wavelength and stimulus purity are measured with a D light source based on JIS Z8722 and displayed according to JIS Z8701.

[0024]

Embodiments of the present invention will be described below. Basic composition of SiO ₂ 72 wt%, Al ₂ O ₃ 2 wt%, MgO 4 wt
_{%, CaO 8wt%, Na 2} O 13wt%, K 2 O 1wt%, a total of 100wt
%, And mixed and adjusted using silica sand, feldspar, soda ash, dolomite, and limestone as raw materials. A desired amount of Fe ₂ O ₃ (FeO), CoO, C
Bengala, cobalt oxide, chromium oxide, selenium, and nickel oxide were added and mixed to contain r ₂ O ₃ , NiO, and Se. Glauberite as a fining agent and an oxidizing agent was introduced as Na ₂ SO _{4 in an} amount of 1% by weight or less based on 100% by weight of the oxide glass.
A small amount of carbon or slag coexisted to assist the decomposition of sodium sulfate.

The raw materials are blended in a desired ratio, and the blended raw materials are put into a crucible, which is provided with a resistance heating body on the ceiling and side walls of the furnace, and set in an electric furnace heated and maintained at about 1450 ° C. Melt and vitrify for about 3 to 4 hours, hold at about 1400 to 1430 ° C. for about 1.5 to 2 hours for homogenization and clarification, then pour out into a mold to form a glass block, cut out into a plate shape, and grind and polish. And each measurement sample.

For these samples, the content (% by weight) of the coloring / color tone adjusting component composition was analyzed by a gravimetric method, and the visible light transmittance (%) and the ultraviolet light transmittance (%) as optical characteristics (at 3.5 mm thickness) were obtained. %), the solar transmittance (%), and dominant wavelength (nm: at illuminant D _65), an excitation purity (%: at illuminant D ₆₅₎ was determined. They are measured and calculated using a U4000 type spectrophotometer (manufactured by Hitachi, Ltd.) in accordance with the standard.

Furthermore, the melt homogeneity was observed with the naked eye, and the samples were classified into those having good homogeneity (A), those having poor homogeneity, and those having fine bubbles remaining (B).

As shown in Tables 1 to 4, in the glass of this embodiment, the coloring and color tone adjusting components are contained within a desired range, and the visible light transmittance, ultraviolet light transmittance, solar light transmittance, main wavelength, stimulus purity, etc. Optical properties are within the expected range, have relatively low visible light transmittance, maintain appropriate transparency and privacy, moderately shield ultraviolet rays and solar radiation, and easily melt glass. And dark gray glass suitable for vehicles such as automobiles, windowpanes for transportation equipment, windowpanes for construction, and the like.

On the other hand, in Comparative Examples 1 and 2, the Cr ₂ O ₃ content was low, the solar transmittance (ie, the heat ray transmittance) was lower than the visible light transmittance, and the melt homogeneity belonged to rank A. , Slightly inferior to the examples. Comparative Example 3 also has a lower solar transmittance than the visible light transmittance. Comparative Example 4 has a high content of Fe ₂ O ₃ and FeO, has a different coloring component system, has a different optical characteristic, exhibits a dark green color, and has clearly inferior melt homogeneity as compared with the examples.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

According to the glass of the present invention, the optical characteristics such as visible light transmittance, ultraviolet light transmittance, solar light transmittance, dominant wavelength, and stimulus purity are within the expected range, and the relatively low visible light transmittance. It has a suitable level of transparency and privacy, shields ultraviolet rays and solar radiation appropriately, and is easy to melt glass, and is suitable for vehicles such as automobiles, windowpanes for transportation equipment and windowpanes for construction. A suitable dark gray glass can be obtained.

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Claims (1)

[Claims] 1. A soda-lime-silica-based glass having a basic composition of 0.3 to 0.8 Fe ₂ O ₃ (total iron) in a weight% as a coloring component.
FeO 0.06-0.18, CoO 0.0050- <0.0140, Cr ₂ O ₃ 0.0030
~ 0.0200, Se 0.0005 ~ 0.0025, and the ratio of ferrous ions to total iron ions (Fe ²⁺ / (Fe ²⁺ + Fe ³⁺ ))
It has a component composition comprised between 0.2 and 0.3, and has a glass plate thickness of 3.
35-55% visible light transmittance at 5mm, 35% solar radiation transmittance
~ 60%, UV transmittance 25% or less, provided visible light transmittance ≤
It is the solar transmittance, and the dominant wavelength by the D light source is 480
A dark gray glass having an optical characteristic of 〜580 nm and an excitation purity of 4% or less.