JP2017124960A - Ultraviolet ray absorption glass sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet ray absorption glass sheet having high ultraviolet ray absorption performance, capable of being used for a rear glass or a side glass for vehicles.SOLUTION: There is provided an ultraviolet ray absorption glass sheet containing a coloring component in a composition of a soda lime silicate glass and having ultraviolet transmissivity calculated by a method according to ISO9050:2003 at sheet thickness of 2.6 mm of less than 2.0%, where the coloring component contains all iron oxide in terms of FeOof 1.3 to 1.8 mass%, FeO of 0.25 to 0.70 mass%, TiOof 0.01 to 1.0 mass%, CeOof 1.0 to 2.5 mass%, CaO of 100 to 300 ppm, chromium oxide in terms of CrOof 1 to 50 ppm, Se of 0 to 50 ppm and manganese oxide in terms of MnOof 0 to 3000 ppm and having all iron oxide+TiO+CeOin terms of FeOof 3.4 mass% to 5.0 mass%.SELECTED DRAWING: None

Description

  The present invention relates to an ultraviolet-absorbing glass plate used for rear glass, side glass and the like for vehicles, particularly for automobiles.

A privacy glass plate, which is a dark gray glass plate, is used for a rear glass and a side glass of an automobile with low visibility from the outside of the vehicle. The privacy glass plate includes soda lime silicate glass (generally defined by ISO 16293-1: 2008), Fe ₂ O ₃ , Se, CoO, NiO, A float glass plate containing a coloring component such as Cr ₂ O ₃ is used (for example, Patent Documents 1 to 3).

  Conventionally, a glass plate having a thickness of about 4 mm has been used as the privacy glass plate as described above. However, in recent years, attempts have been made to reduce the weight of vehicles, and as one of the attempts, studies have been made to reduce the thickness of the glass plate used. Various transmittances of glass plates increase as the plate thickness decreases. Conventionally, glass having the ability to absorb ultraviolet rays has been developed. However, when the thickness of the glass plate is reduced, there is a problem that the transmittance of ultraviolet rays increases and the ultraviolet absorbing performance is impaired. Therefore, there is a demand for a glass having higher ultraviolet absorption performance than before. For example, Patent Document 4 proposes privacy glass (for example, 2% or less with a thickness of 2.5 mm) having higher ultraviolet absorption performance.

JP-A-10-182183 JP 11-217234 A JP 2011-251882 A International Publication No. 2015/0888026

As described above, in recent years, there has been a demand for a privacy glass plate for a vehicle with improved ultraviolet absorption performance. In order to improve the UV absorption performance and the light absorption performance of each wavelength, it may be possible to increase the iron oxide content. However, if the iron oxide content increases, the iron component absorbs the heat of combustion when the glass melts. However, since the temperature rise in the melting furnace is hindered, there is a potential problem that the manufacturing cost increases. Therefore, for example, in Patent Document 4, the ultraviolet absorption performance is improved by increasing the content of TiO ₂ which is a coloring component.

However, in a glass composition in which iron oxide and TiO ₂ coexist, when the content of TiO ₂ is increased, the visible light transmittance may be unintentionally lowered significantly. This is thought to be due to the strong absorption of iron in the trivalent visible region, but it is unclear what effect TiO ₂ has on iron oxide. As described above, the privacy glass having a low visible light transmittance is preferred, but on the other hand, if there is no appropriate transmittance, a safety problem may occur.

For the purpose of improving the ultraviolet absorption performance, it is generally known that CeO ₂ is contained in addition to TiO ₂ . However, as a result of investigations by the present inventors, when the content of CeO ₂ is increased in a composition system not containing TiO ₂ , the ultraviolet transmittance calculated by a method based on ISO 9050: 2003 is reduced to a specific amount or less. I found it difficult.

  Accordingly, an object of the present invention is to obtain a UV-absorbing glass plate having high UV-absorbing performance that can be used for a vehicle rear glass and side glass even with a thinner thickness than conventional ones.

It was found that when the total content of iron oxide, TiO ₂ , and CeO ₂ was increased, the ultraviolet transmittance at a plate thickness of 2.6 mm could be made less than 2.0%. Moreover, by containing CeO ₂ in a certain amount with a composition in which TiO ₂ is suppressed to 1.0% by mass or less, it is possible to achieve both the high ultraviolet transmittance and the visible light transmittance of 10 to 35%. It turns out that it can be used without any problem as a privacy glass for automobiles.

In addition, in the process of the above study, it has been newly found that the tendency of yellowing the transmitted color increases as the ultraviolet transmittance decreases. In general, it is known that when the content of iron oxide or TiO ₂ increases, the transmitted color exhibits a yellowish color, but the ultraviolet transmittance at a thickness of 2.6 mm is less than 2.0%. Then, there was no simple correlation with the content of iron oxide or TiO ₂ , and even when the content of the component was about the same, there was a phenomenon that there was a strong yellow color and a weak one. Further examination of the above phenomenon revealed that yellowing tends to be suppressed by increasing the proportion of FeO in the iron oxide.

That is, this invention contains a coloring component in the composition of soda-lime silicate glass, and the ultraviolet transmittance calculated by a method based on ISO 9050: 2003 at a plate thickness of 2.6 mm is less than 2.0%. In the ultraviolet absorbing glass plate, the coloring components are 1.3 to 1.8% by mass of total iron oxide converted to Fe ₂ O ₃ , 0.25 to 0.70% by mass of FeO, and 0.02 of TiO ₂ . 01 to 1.0 wt%, the CeO ₂ 1.0 to 2.5 wt%, 100 to 300 ppm of CoO, 1 to 50 ppm chromium oxide in terms of _Cr 2 _{O 3,} the Se 0 to 50 ppm, and MnO _It contains 0 to 3000 ppm of manganese oxide converted to ₂ , and the total iron oxide + TiO ₂ + CeO ₂ converted to Fe ₂ O ₃ is 3.4% by mass or more and 5.0% by mass or less. With features That is a UV-absorbing glass plate.

  The ultraviolet-absorbing glass plate of the present invention has an ultraviolet transmittance of less than 2.0% calculated by a method based on ISO 9050: 2003 at a plate thickness of 2.6 mm, and in accordance with JIS Z 8722: 2009 at the same plate thickness. The spectral transmittance of the specimen is obtained, and the visible light transmittance in terms of percentage of the stimulation value Y with respect to the standard light A is 10% or more.

Here, CeO ₂ is an expensive raw material, and there is a problem that the manufacturing cost increases when used in large quantities. As a result of intensive studies by the present inventors, it has been found that desired optical characteristics can be obtained even if the amount is less than 1.0% by mass.

That is, the present invention includes an ultraviolet ray containing a coloring component in the composition of soda-lime silicate glass and having an ultraviolet transmittance of less than 2.0% calculated by a method based on ISO 9050: 2003 at a plate thickness of 2.6 mm. in absorbing glass plate, the coloring component, the total iron oxide in terms of _Fe 2 _{O 3} 1.3 to 1.8 wt%, the FeO from .25 to 0.70 wt%, the TiO ₂ 0.60 1.0 wt%, 0 to 50 ppm of CeO ₂ 0.8 to 1.5 wt%, 100 to 300 ppm of CoO, 1 to 50 ppm chromium oxide in terms of _Cr 2 _{O 3,} the Se, and MnO ₂ 1 to 4000 ppm of manganese oxide converted to, and the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 3.4 mass% or more and 4.0 mass% or less. Features It is a UV-absorbing glass plate.

  As described above, according to the present invention, it is possible to obtain a UV-absorbing glass plate having high UV-absorbing performance, which can be used for vehicle rear glass and side glass. Further, according to the present invention, it is possible to obtain a UV-absorbing glass plate that suppresses the yellowness of the transmitted color.

1st invention contains a coloring component in the composition of soda-lime silicate glass, and the ultraviolet-ray transmittance computed by the method based on ISO9050: 2003 in plate | board thickness 2.6mm is less than 2.0% In the ultraviolet absorbing glass plate, the coloring components are 1.3 to 1.8% by mass of total iron oxide converted to Fe ₂ O ₃ , 0.25 to 0.70% by mass of FeO, and 0.02 of TiO ₂ . 01 to 1.0 wt%, the CeO ₂ 1.0 to 2.5 wt%, 100 to 300 ppm of CoO, 1 to 50 ppm chromium oxide in terms of _Cr 2 _{O 3,} the Se 0 to 50 ppm, and MnO _It contains 0 to 3000 ppm of manganese oxide converted to ₂ , and the total iron oxide + TiO ₂ + CeO ₂ converted to Fe ₂ O ₃ is 3.4% by mass or more and 5.0% by mass or less. Purple characterized It is a line-absorbing glass plate.

Moreover, 2nd invention contains a coloring component in the composition of soda-lime silicate glass, and the ultraviolet-ray transmittance computed by the method based on ISO9050: 2003 in plate | board thickness 2.6mm is less than 2.0% In the ultraviolet absorbing glass plate, the coloring components are 1.3 to 1.8% by mass of total iron oxide converted to Fe ₂ O ₃ , 0.25 to 0.70% by mass of FeO, and TiO ₂ . 0.60 to 1.0 wt%, the CeO ₂ 0.8 to 1.5 wt%, 100 to 300 ppm of CoO, 1 to 50 ppm chromium oxide in terms of _Cr 2 _{O 3,} the Se 0 to 50 ppm, 1 to 4000 ppm of manganese oxide converted to MnO ₂ , and the total iron oxide + TiO ₂ + CeO ₂ converted to Fe ₂ O ₃ is 3.4 mass% or more and 4.0 mass% or less. It is characterized by being That is a UV-absorbing glass plate.

  In the present specification, the “present invention” refers to the first invention and the second invention, and “first invention” and “second invention” only when there is a need to distinguish between them. It shall be described.

1: Optical properties The values of various optical properties vary depending on the thickness of the glass plate. For example, the values of various transmittances such as ultraviolet transmittance become lower as the thickness of the glass plate increases. Accordingly, in the present specification, various optical characteristics when the thickness of the glass plate (hereinafter sometimes referred to as “plate thickness”) is 2.6 mm are used. Moreover, the said optical characteristic was computed by the method based on each specification from the value measured using spectrophotometer U-4100 (made by Hitachi, Ltd.).

(UV transmittance)
In this specification, the ultraviolet transmittance calculated by a method based on ISO 9050: 2003 is used as the ultraviolet transmittance. In the present invention, the ultraviolet transmittance is less than 2.0%, preferably 1.7% or less, more preferably 1.5% or less.

(Solar radiation transmittance)
In this specification, the solar radiation transmittance computed by the method based on JISR3106: 1998 is used as solar radiation transmittance. Although the solar radiation transmittance is not particularly limited, it is preferable to lower the solar radiation transmittance because the rate of solar heat entering the vehicle decreases and the cooling efficiency can be improved. For example, it may be 30% or less, preferably 25% or less. Moreover, it is possible to make it less than 22% by making content of FeO into a specific range.

(Visible light transmittance)
In this specification, the spectral transmittance of the specimen is obtained according to JIS Z 8722: 2009, the value representing the stimulation value Y with respect to the standard light A as a percentage is defined as the visible light transmittance, and in the present invention, the lower limit is set to 10 % Or more. Moreover, it is good also as 15% or more preferably. The visible light transmittance is not particularly limited as long as the visibility from the outside of the vehicle is low, but may be, for example, 35% or less, preferably 30% or less.

(Transparent color)
In the present specification, as the transparent color of the glass plate, JIS Z 8781-4: use than 2013, the CIE ^L * ^a * ^{b *} chromaticity coordinates diagram calculated by standard illuminant _{D 65} 2 degree observer ^a *, and ^{b *} It was. The above chromaticity coordinates indicate that the greater a * is negative, the more green, the more positive, the red, the more b ^* is negative, the blue, and the greater positive, the yellow. In general, in the above chromaticity coordinates, when the absolute values of a ^* and b ^* approach 20, respectively, each color is strongly exhibited. As the absolute value approaches 0, the turbid color (gray) ). In the study by the present inventors, when the suppression of yellowishness is insufficient, b ^* may have a value of about 16 or more, but according to a preferred embodiment of the present invention, b ^* is less than 13. It became possible to do. In the present invention, a ^* is between -13 and 0, and the whole tends to exhibit a gray color.

(Stimulus purity)
In this specification, the excitation purity, JIS Z 8701: By 1999, with a value calculated by the standard illuminant _{D 65} 2 degree observer. If the stimulus purity is too high, the yellow color becomes strong, and the appearance quality may not be preferable. Preferably, it may be less than 30, more preferably less than 20.

2: Soda lime silicate glass Hereinafter, the soda lime silicate glass of the present invention will be described. Soda lime silicate glass is by weight, SiO ₂ 65-75, Na ₂ O 10-20, K ₂ O 0-3, CaO 5-15, MgO 0-5, and Al _2. It contains 0 to 3, O ₃ .

SiO ₂ is a main component for forming a glass skeleton, and is preferably contained in an amount of 65 to 75% by mass. If it is less than 65% by mass, the surface is likely to be burned and the weather resistance may be lowered. Moreover, when it exceeds 75 mass%, it will become difficult to perform processes, such as a heat strengthening after forming a glass plate, and also it may become difficult to fuse | melt a raw material.

Na ₂ O is a component that promotes melting of the raw material, and is preferably contained in an amount of 10 to 20% by mass. If it is less than 10% by mass, melting of the raw material becomes difficult and devitrification tends to occur. Moreover, when it exceeds 20 mass%, a weather resistance may fall.

K ₂ O is a component that promotes melting of the raw material and is preferably contained in an amount of 0 to 3% by mass. If it exceeds 3% by mass, the weather resistance may deteriorate.

  CaO is a component that promotes melting of the raw material and improves the weather resistance, and is preferably contained in an amount of 5 to 15% by mass. If it is less than 5% by mass, melting of the raw material tends to be difficult, and if it exceeds 15% by mass, devitrification tends to occur in the glass.

  MgO is a component that promotes melting of raw materials and improves weather resistance, and is preferably contained in an amount of 0 to 5 mass%. When MgO exceeds 5 mass%, it may be difficult to perform treatment such as heat strengthening after the glass plate is formed.

Al ₂ O ₃ is a component that improves weather resistance, and is preferably contained in an amount of 0 to 3% by mass. If it exceeds 3% by mass, devitrification is likely to occur in the glass.

3: Coloring component The present invention is a glass in which a coloring component is contained in the soda lime silicate glass. The coloring component will be described below.

(Essential ingredients)
Iron oxide is an essential component, and is a main component that improves ultraviolet absorption performance and infrared absorption performance. The iron oxide is in a state in which divalent and trivalent are mixed in the glass, and the ratio varies depending on the reduced state of the glass. Therefore, the content of iron oxide is expressed in terms of Fe ₂ O ₃ . In the present invention, the iron oxide in terms of _Fe 2 _{O 3} contains 1.3 to 1.8 wt%. If it is less than 1.3% by mass, the UV absorption performance tends to be insufficient. On the other hand, if it exceeds 1.8% by mass, the combustion heat of the burner or the like is easily absorbed by the glass substrate surface in the melting furnace, resulting in a decrease in production efficiency. There are things to do. Preferably, the lower limit may be 1.35% by mass or more, more preferably 1.40% by mass or more. Further, the upper limit is preferably 1.75% by mass or less, more preferably 1.70% by mass or less.

In the present invention, a part of the iron oxide is reduced to FeO, and the yellow color of the transmitted color is suppressed. In general, FeO is known as a component that improves infrared absorption performance and lowers solar radiation transmittance. When the amount of total iron oxide is the same, when the content of FeO increases, the content of trivalent Fe ₂ O ₃ that exhibits ultraviolet absorption performance decreases, so the content of FeO is not more than a predetermined amount. There is a need to. Therefore, in the present invention, the content is within the range of 0.25 to 0.70 mass%. Further, the lower limit is preferably 0.28% by mass or more, more preferably 0.30% by mass or more. The upper limit value is preferably 0.68% by mass or less, more preferably 0.65% by mass or less.

As described above, FeO is included in the composition by reducing a part of the iron oxide. The reduction ratio (Fe ²⁺ / (Fe ³⁺ + Fe ²⁺ )), which is the ratio of reducing iron oxide, is not particularly limited as long as suitable physical property values can be obtained. .About 20 to 0.50.

TiO ₂ is an essential component that improves ultraviolet absorption performance. If only iron oxide and CeO ₂ without TiO ₂ are used, the ultraviolet absorption performance tends to be insufficient. On the other hand, if the content of TiO ₂ is increased in the state where TiO ₂ and iron oxide coexist as described above. The visible light transmittance may be unintentionally lowered. Therefore, in 1st invention, it shall contain 0.01-1.0 mass%. Further, the lower limit is preferably 0.10% by mass or more, more preferably 0.45 or more. Further, TiO ₂ tends to act as a reducing agent in the composition system of the present invention, and it is considered that coexistence with CeO ₂ acting as an oxidizing agent suppresses excessive oxidation of the glass. Incidentally, TiO ₂ is present in the form of ^{Ti 3+} and ^{Ti 4+} in glass, in the present specification using a value obtained by converting the total volume of TiO _2.

In the second invention, it is intended to include TiO ₂ from .60 to 1.0 wt%. The second invention is a composition in which the content of CeO ₂ used as an ultraviolet absorbing component is reduced as much as possible. Preferably, the lower limit may be 0.70% by mass or more.

CeO ₂ is an essential component for improving the ultraviolet absorption performance, and the first invention contains 1.0 to 2.5% by mass. If the lower limit is less than 1.0% by mass, the intended ultraviolet absorption performance tends to be unachievable, and if it exceeds 2.5% by mass, the action as an oxidizing agent on the glass becomes strong, and the desired FeO It can be difficult to get. Further, the upper limit value is preferably 2.0% by mass or less. Although CeO ₂ exists in the form of Ce ³⁺ and Ce ^{4+ in} the glass, a value obtained by converting the total amount to CeO ₂ was used in this specification.

In the second invention, containing CeO ₂ 0.8 to 1.5 wt%. At this time, it is possible to achieve desired optical characteristics by setting the content of TiO ₂ to 0.6 mass% or more and containing 1 to 4000 ppm of manganese oxide. The In the second invention, since it is possible to reduce the content of CeO _2, it is possible to reduce the manufacturing cost.

The above iron _oxide, TiO 2, CeO ₂ is a component for improving the ultraviolet absorption performance, 3 the content of the component (iron oxide amount converted into _F 2 _{O 3)} the sum of 3.4 wt% By setting it as the above, it becomes possible to make the ultraviolet-ray transmittance in thickness 2.6mm less than 2.0%. Moreover, it is good also as 3.5 mass% or more preferably. From the viewpoint of ultraviolet transmittance, it is not necessary to specifically limit the upper limit value, but if the total value is too large, efficient production may be difficult, and the visible light transmittance becomes excessively low. Therefore, the upper limit is set to 5.0% by mass or less in the first invention, and the upper limit is set to 4.0% by mass or less in the second invention.

  CoO is an essential component that lowers the visible light transmittance and adds blue to the transmitted color, and is contained in an amount of 100 to 300 ppm. Preferably it is good also as 130-290 ppm.

Chromium oxide is an essential component that lowers the ultraviolet transmittance and the visible light transmittance and adjusts the transmitted color, and adds 1 ppm or more in terms of Cr ₂ O ₃ . In addition, if it is contained excessively, the visible light transmittance is unnecessarily low, and there is a problem that the safety is lowered and the problem that the transmitted color is yellowish. 50 ppm. Incidentally, the chromium oxide is present in the form of Cr ³⁺ and Cr ⁶⁺ is in the glass, in the present specification using a value obtained by converting a total volume of Cr ₂ O _3.

(Optional component)
Se is an optional component that lowers the ultraviolet transmittance, visible light transmittance, and solar radiation transmittance. Also, it has a function of adjusting the transmission color, and in the composition system of the present invention, as the Se content is increased, a ^* tends to approach 0, and the glass color can be made closer to gray. Become. Since Se is a component that easily volatilizes, it is difficult to keep it in the glass, so in the present invention, the upper limit is set to 50 ppm or less. Moreover, since it is not an essential component, the lower limit may be 0 ppm, but it is preferable to contain it from the viewpoint of the above effects. If the lower limit is 1 ppm or more, a ^* is preferably −10 or more, and 10 ppm or more because a ^* can be −8 or more. Further, the upper limit value is preferably 40 ppm or less.

Manganese oxide is an optional component that helps maintain highly volatile Se during glass melting and adjusts the transmitted color. In the first invention, manganese oxide may be contained at 3000 ppm or less. Further, since manganese oxide has a plurality of oxidation states mixed in glass, a value obtained by converting the total amount into MnO ₂ is used in this specification. Moreover, in 2nd invention, it is desirable to contain 1-4000 ppm of manganese oxides as an essential component which assists in improving ultraviolet absorption performance. The lower limit is preferably 1000 ppm or more, more preferably 2000 ppm or more.

In addition to the above, the coloring component is 1.0% by mass in total of arbitrary components such as V ₂ O ₅ , MoO ₃ , CuO, SO ₃ , and SnO _{2 for} the purpose of adjusting the transmission color and the reduction state of the glass. Hereinafter, it may be contained within a range of preferably 0.5% by mass or less. Note that the SO _3, is derived from the sodium sulfate added as a clarifying agent in the manufacturing process of the glass, it may be included in small amounts in the composition.

  Moreover, since NiO brings about the formation of nickel sulfide in the glass, its inclusion is not desirable. Nickel sulfide can hardly be visually confirmed and does not harm the glass under normal conditions, but the thermal expansion coefficient is large, so the stress balance may be lost due to its volume expansion during thermal strengthening, and the glass may break. . However, since it is also a component that adjusts the transmission color of the glass, it may be contained as an optional component at 50 ppm or less.

4: First Embodiment Hereinafter, a first embodiment of the present invention will be described. In the present embodiment, the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is set to 3.4 mass% or more and less than 4.0 mass%, whereby the ultraviolet transmittance at a thickness of 2.6 mm is set to 2. It becomes possible to make it less than 0%. Further, in the composition system within the above range, by a 0.25 to 0.70 wt% the proportion of ^{FeO, CIE L * a * b} * in chromaticity coordinates diagram of the transmitted light ^{b *} was less than 13, It becomes possible to suppress yellowness of transmitted light.

In the present embodiment, the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 3.4 mass% or more and less than 4.0 mass%, and FeO is 0.40 to 0.70 mass. By setting it as%, the solar radiation transmittance when the thickness is 2.6 mm calculated by a method based on JIS R3106: 1998 can be made less than 22%.

5: Second Embodiment Hereinafter, a second embodiment of the present invention will be described. In this embodiment, the total iron oxide + TiO ₂ + CeO ₂ converted to 0.4 to 1.0% by mass of TiO ₂ and Fe ₂ O ₃ is 4.0% by mass or more and 5.0% by mass or less, TiO _2. / FeO is 0.60 or more and less than 2.35.

In this embodiment, even if the FeO content is simply increased, there are cases where the reduction in yellowness is insufficient, and when further investigation is performed, the balance between the TiO ₂ content and the FeO content is observed. Thus, it was found that the b ^* of transmitted light in the CIE L ^* a ^* b ^* chromaticity coordinate diagram can be made less than 13 to reduce yellowness.

Further, in the present embodiment, the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 4.0 mass% or more and 5.0 mass% or less, and TiO ₂ / FeO is 0.60 or more, By setting it to 2.20 or less, it is possible to make the solar radiation transmittance at a thickness of 2.6 mm calculated by a method based on JIS R3106: 1998 less than 22%.

6: Manufacturing method of ultraviolet-absorbing glass plate The present invention can be manufactured using a float process. The float method is a method generally used when manufacturing a glass plate. In this method, a raw material batch, or a raw material batch and a glass cullet are first put into a melting furnace that melts the raw material to form molten glass, and then the molten glass is poured onto molten tin to form a plate, and then molded. In this method, the glass plate is cooled to obtain the glass plate. Moreover, you may adjust the reduction | restoration state of glass by adding the reducing agent etc. which are not contained in a composition at the time of a fusion | melting.

  The glass plate obtained as described above is cut and processed into a desired shape. When using for vehicles, after cutting, heating may be performed and strengthening processing may be performed. As a heat-strengthening treatment, the air-cooling strengthening treatment is generally well known, and the method of performing the air-cooling strengthening treatment is, for example, heating the glass to near the glass transition temperature while carrying the glass plate with a carrying roll. After the temperature of the glass plate rises to a desired temperature, the glass plate is tempered by blowing air from the cooling nozzle. At this time, the wind blown is preferably 5 to 30 kPa, more preferably 7 to 20 kPa. In the glass plate of the present invention, preferably, when the temperature of the glass plate is 550 to 670 ° C., more preferably 580 to 670 ° C., wind cooling is started by blowing air from the cooling nozzle to the plate glass.

  Examples and Comparative Examples of the present invention are shown below.

As the glass raw material, silica glass, aluminum oxide, sodium carbonate, potassium carbonate, calcium carbonate and magnesium oxide are used as the raw material of the glass mother composition, and ferric oxide, titanium oxide, cerium oxide, oxidation are used as the colorant raw material. Cobalt, chromium oxide, sodium selenite, and manganese dioxide were used. Further, sodium sulfate was used as a clarifying agent, and a carbon-based reducing agent (specifically, carbon powder) was used as a reducing agent. The mother component of the glass mother composition is mass%, SiO ₂ 72.0, Na ₂ O 13.0, K ₂ O 1.0, CaO 8.5, MgO 3.5, and Al _2. The raw material is adjusted so that O ₃ becomes 2.0, and a colorant, a refining agent, and a reducing agent are added to the glass raw material so as to be within a predetermined range and mixed to obtain a glass raw material. . This raw material was heated and melted at 1560 ° C. in an electric furnace. Next, after maintaining the molten state at 1460 ° C. for 6 hours, the temperature was lowered to 1400 ° C. in 1 hour and held for 1 hour to obtain a clear glass melt.

  The obtained glass melt was poured onto a graphite mold and then slowly cooled to room temperature in another electric furnace to obtain a glass block. Next, this glass block was optically polished until it became a plate having a thickness of 2.6 mm, and a sample for measuring glass component composition having a size of 50 mm × 50 mm and various optical characteristics was obtained.

The obtained glass composition analysis of each sample was performed for Fe, Ti, Ce, Co, Cr, Se, and Mn, respectively, using a fluorescent X-ray analyzer. The components take multiple oxidation states in the glass, in terms as given oxidation state described in the specification, the composition ratio is _{Fe 2 O 3, TiO 2,} CeO 2, CoO, Cr 2 O 3, Se And using MnO ₂ . Further, the content of FeO was determined from the transmittance at an infrared wavelength of about 1100 nm, and the reduction rate of iron (Fe ²⁺ / (Fe ³⁺ + Fe ²⁺ )) was determined from the total amount of iron oxide and the content of FeO.

In addition to the above components, some optional components (for example, NiO, SO _3, etc.) were contained within a range that does not greatly affect the optical properties of the sample. These are components included in various adjustment materials added when manufacturing unintentional mixing from materials or glass. For example, NiO was not added as a raw material at this time, but it was mixed as an impurity from a raw material batch or glass cullet and contained in each sample in a proportion of less than 10 ppm. Further, SO ₃ is derived from sodium sulfate added as a clarifying agent, and was contained in each sample in an amount of about 0.1% by mass.

  The optical characteristics were calculated from values measured using a spectrophotometer U-4100 (manufactured by Hitachi, Ltd.) by a method in accordance with ISO 9050: 2003 for ultraviolet transmittance and JIS R 3106: 1998 for solar radiation transmittance. Further, as described above, the visible light transmittance was obtained by obtaining the spectral transmittance obtained according to JIS Z 8722: 2009, and using the value of the stimulation value Y with respect to the standard light A as a percentage.

Further, as the transparent color, JIS Z 8781-4: from 2013, the CIE ^L * ^a * ^{b *} chromaticity coordinates diagram calculated by standard illuminant _{D 65} 2 degree observer ^a *, was determined ^{b *.} Further, the excitation purity and dominant wavelength, JIS Z 8701: By 1999, with a value calculated by the standard illuminant _{D 65} 2 degree observer.

Tables 1 to 3 show the glass composition and optical properties of the obtained samples. In the table, Fe ₂ O ₃ (total iron) represents the total amount of iron oxide, and FeO represents the content of divalent iron oxide.

From Tables 1 and 2, it was found that in each of the examples of the present invention, the ultraviolet transmittance with a plate thickness of 2.6 mm was less than 2.0%, and the visible light transmittance was 10% or more. In addition, the ultraviolet transmittance is in the range of 0.4 to 1.5%, the visible light transmittance is 16.8 to 33.4%, and has high ultraviolet absorption performance and moderate visibility as privacy glass. there were. Moreover, the dominant wavelength of the glass of the Example falls within the range of 505 to 580 nm, and it has been found that the value of b ^* and stimulation purity tend to increase as the dominant wavelength becomes longer. Moreover, the value of a ^* is in the range of -11.37 to -1.40, and in particular Examples 1 to 9, 11, 12, 14 to 17, 19 to 21, 23, and 24 containing Se at 10 ppm or more are , A ^* was −8 or more, and a gray color closer to a neutral color was exhibited.

Examples 1 to 14 are glass compositions in which Fe ₂ O ₃ (total iron) + TiO ₂ + CeO ₂ is in the range of 3.4% by mass or more and less than 4.0% by mass. In all of the above examples, b ^* was less than 13 and the excitation purity was less than 18, and both high ultraviolet absorption performance and excellent appearance quality were achieved. Moreover, Examples 5-14 whose content of FeO is 0.40 mass% or more had solar radiation transmittance of less than 22%, and also had high heat-shielding performance.

Examples 1, ₂ , 4, 6-8, 10, 12-14 are compositions in which the CeO ₂ content falls within the range of 0.93-1.40 mass%. From the above examples, it was found that even when the content of CeO ₂ was reduced from 1.0% by mass, desired optical characteristics could be achieved.

Examples 15 to 24 are glass compositions in which Fe ₂ O ₃ (total iron) + TiO ₂ + CeO ₂ is in the range of 4.0% by mass to 5.0% by mass. In Examples 23 and 24, although the transmitted color was gray, the color tone was slightly strong in yellow. In Examples 15 to 24, when the content of FeO was increased, b ^* tended to decrease, but there was no simple correlation, and it was found that yellowness can be suppressed by the balance of the content of TiO ₂ and FeO. Specifically, Examples 15 to 22 in which TiO ₂ / FeO is less than 2.35 showed b ^* of less than 13. _In Examples 15 to 19 TiO 2 / FeO is 2.20 or less, the solar radiation transmittance was combines and high heat-shielding performance less than 22%.

From Table 3, all of Comparative Examples 1 to 6 had an ultraviolet transmittance of 2.0 or more. Although the comparative examples 7 and 8 have low ultraviolet transmittance, TiO ₂ exceeds 1% by mass and CeO ₂ is not included, so that the composition system is different from that of the present invention. Further, Comparative Examples 7 and 8 had higher stimulation purity than the Examples, and in particular, Comparative Example 7 had a b ^* of about 20 and a strong yellowish transmission color.

In Comparative Example 2, _Fe 2 _{O 3} (total _{iron) +} TiO 2 + CeO ₂ is 3.69 wt%, despite containing CeO ₂ 2.28 wt%, out of range TiO ₂ is of the present invention Therefore, the ultraviolet transmittance was 2.0% or more. That is, it has been found that it is difficult to make the ultraviolet transmittance less than 2.0% by mass only by containing CeO ₂ . Further, if a large amount of CeO ₂ is used, the above optical characteristics may be achieved. However, if a large amount of expensive CeO ₂ is used, the cost increases, which is not preferable for production.

In Comparative Examples 1 and _{3 to 6,} Fe ₂ O ₃ (total iron) + TiO ₂ + CeO ₂ is less than 3.40% by mass, and the ultraviolet transmittance is as high as 2.0% or more. became. In particular, in Comparative Examples 3 to 6, the content of each component of the glass falls within the range of claim 1, but the total value of the above three components is out of the range. Therefore, it was found that the ultraviolet transmittance can be reduced to less than 2.0% by setting Fe ₂ O ₃ (total iron) + TiO ₂ + CeO ₂ to 3.40% by mass or more.

Claims (8)

In the ultraviolet absorbing glass plate containing a coloring component in the composition of soda lime silicate glass and having an ultraviolet transmittance of less than 2.0% calculated by a method based on ISO 9050: 2003 at a plate thickness of 2.6 mm, The coloring component is
1.3-1.8% by mass of total iron oxide converted to Fe ₂ O ₃ ,
0.25 to 0.70% by mass of FeO,
0.01 to 1.0% by mass of TiO ₂
CeO ₂ is 1.0 to 2.5% by mass,
100-300 ppm of CoO,
1 to 50 ppm of chromium oxide converted to Cr ₂ O ₃ ,
It contains 0 to 3000 ppm of manganese oxide converted to 0 to 50 ppm Se and MnO ₂ ,
The ultraviolet-absorbing glass plate, wherein the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 3.4% by mass or more and 5.0% by mass or less. In the ultraviolet absorbing glass plate containing a coloring component in the composition of soda lime silicate glass and having an ultraviolet transmittance of less than 2.0% calculated by a method based on ISO 9050: 2003 at a plate thickness of 2.6 mm, The coloring component is
1.3-1.8% by mass of total iron oxide converted to Fe ₂ O ₃ ,
0.25 to 0.70% by mass of FeO,
0.60 to 1.0% by mass of TiO ₂
CeO ₂ 0.8-1.5% by mass,
100-300 ppm of CoO,
1 to 50 ppm of chromium oxide converted to Cr ₂ O ₃ ,
It contains 1 to 4000 ppm of manganese oxide converted to Se of 0 to 50 ppm and MnO ₂ ,
An ultraviolet-absorbing glass plate, wherein the total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 3.4% by mass or more and 4.0% by mass or less. The total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 3.4% by mass or more and less than 4.0% by mass,
The ultraviolet-absorbing glass plate according to claim 1 or 2, wherein b ^* of transmitted light in the CIE L ^* a ^* b ^* chromaticity coordinate diagram is less than 13 at a plate thickness of 2.6 mm. FeO is 0.40 to 0.70 mass%,
The ultraviolet-absorbing glass plate according to claim 3, wherein the solar radiation transmittance calculated by a method according to JIS R 3106: 1998 is less than 22% at a plate thickness of 2.6 mm. The TiO ₂ is 0.4 to 1.0% by mass,
Total iron oxide converted to Fe ₂ O ₃ + TiO ₂ + CeO ₂ is 4.0 mass% or more, 5.0 mass% or less,
TiO ₂ / FeO is 0.60 or more and less than 2.35,
The ultraviolet-absorbing glass plate according to claim 1, wherein b ^* of transmitted light in the CIE L ^* a ^* b ^* chromaticity coordinate diagram is less than 13 at a plate thickness of 2.6 mm. The TiO ₂ / FeO is 0.60 or more and 2.20 or less,
6. The ultraviolet absorbing glass plate according to claim 5, wherein the solar radiation transmittance calculated by a method according to JIS R 3106: 1998 is less than 22% at a plate thickness of 2.6 mm. The soda lime silicate glass is in mass%,
SiO ₂ and 65 to 75,
10-20 Na ₂ O,
K ₂ O from 0 to 3,
CaO 5-15,
MgO 0-5, and _Al 2 _{O 3} 0-3, ultraviolet absorbing glass plate according to any one of claims 1 to 6, characterized in that those containing. A method for producing an ultraviolet-absorbing glass plate, comprising producing the ultraviolet-absorbing glass plate according to any one of claims 1 to 7 using a float process.