EA037710B1 - Soda lime glass sheet - Google Patents

Abstract

The purpose of the invention is to provide a glass that has a grey color closer to an achromatic color, and that at the same time has a high heat-insulating performance and visible light transmittance. The present invention relates to a soda lime glass sheet wherein a total sulfur content as SO3 is 0.001-0.2%; a total iron content as Fe2O3 is 0.15-0.4%; a total tin content as SnO2 is 0.02-1%; a mass proportion, in the total iron as Fe2O3, for divalent iron as Fe2O3 is 45-70%; a visible light transmittance Tv_A is at least 70%; a solar heat gain coefficient Tts is not more than 63.7%; and a c*> is not more than 4 with reference to the L*a*b* color space.

Description

Technology area

The invention relates to soda-lime thick-sheet glass and, in particular, to soda-lime thick-sheet glass having a high heat-insulating property.

State of the art

As the window panes of vehicles such as automobiles, it is necessary to use soda-lime thick-plate glass having a high thermal insulation property (soda-lime thick plate glass hereinafter may be referred to simply as glass). When glass has a low thermal insulation property, the temperature inside vehicles receiving solar radiation rises. The rise in temperature not only makes passengers uncomfortable, but also increases the load on the cooling system, leading to a deterioration in fuel consumption.

Total Solar Transmittance (Tts), determined according to ISO-13837: 2008 Method A, is a measure of the thermal insulation properties of glass. Low Tts means low solar energy transmittance, i.e. high heat-insulating property. The coefficient (Te) of direct sunlight transmission, defined in ISO-13837A: 2008, is a measure that is related to Tts, and they have such a relationship that Tts decreases as Te decreases.

Vehicle window panes need high visible light transmission in terms of visibility and safety. In the road vehicle law safety standards, the front windshields of a car are required to have a visible light transmittance of 70% or more. Visible light transmittance (Tv_A) defined in JIS R3106: 1998 is a measure of visible light transmittance.

Patent Literature 1 describes heat absorbing plate glass having a Te of 50% or less as a converted value for 4 mm thick plate glass. The Tv_A of heat absorbing heavy plate is more than 65% as the converted value for 4 mm thick plate.

List of links

Patent literature.

Patent Literature 1: WO 2015/170759 A1.

Disclosure of invention

Technical problem.

In glass, iron is present as ferrous iron or as ferric iron. Ferrous iron has an absorption peak near 1100 nm and ferric iron has an absorption peak near 400 nm. In order to reduce the Tts and increase the thermal insulation property while maintaining high visible light transmission of the glass, it is believed that the ferrous content that allows light to pass through the visible light and allows the light to be absorbed in the infrared should be increased. In order to achieve this, it is believed that the proportion of ferrous iron relative to total iron (redox ratio) is increased. However, an increase in the redox ratio leads to such an unfavorable result that an amber-yellow color is obtained in the glass when the sulfur (S) contained as the brightening component is reduced. The addition of tin (Sn) can be effective to avoid the formation of an amber yellow color. However, Sn is expensive and as the added amount is increased, the volatility of Sn in the production line increases. Therefore, the amount of added Sn is limited. In addition, an unacceptable amount of Sn can adversely affect the redox ratio of the iron. Thus, the respective components have respective advantages and limitations and influence each other. Therefore, it was difficult to find the optimal balance of these components.

In addition, iron can provide the Tts decreasing action as described above, but acts as a coloring agent. As a result, conventional glass with high thermal insulation was tinted green or blue. However, staining is not always desirable, as is the case for vehicle window panes.

The present invention aims to provide a soda-lime thick-plate glass having a high thermal insulation property and a high transmission of visible light and at the same time having a gray color close to an achromatic color.

Solution to the problem.

The present invention contains the following aspects.

[1] Soda lime glass plate having a total sulfur content in terms of SO ₃ 0.001-0.2% by weight based on oxides;

the total iron content in terms of Fe ₂ O ₃ 0.15-0.4% in wt.% based on oxides;

the total content of tin in terms of SnO ₂ from 0.02-1% in wt.% based on oxides;

mass fraction of ferrous iron in terms of Fe2O3 in total iron in terms of Fe2O3 4570%;

visible light transmittance Tv_A defined in JIS R3106: 1998, 70% or more as a converted value for 3.85 mm thick plate glass;

- 1 037710 total solar transmittance Tts, determined according to ISO-13837: 2008 Method A, 63.7% or less as a converted value for 3.85 mm thick plate glass; and c * in the L * a * b * color space defined in JIS Z8781-4: 2013, 4 or less, as the converted value for 3.85 mm thick plate glass.

[2] Soda lime glass plate according to the above [1] having a Se content of 5-20 parts per million (ppm) by weight.

[3] Soda lime glass plate according to [1] or [2] above, having a total cobalt content in terms of CoO of 0-15 ppm by weight based on oxides.

[4] Soda lime glass plate according to any of the above [1] to [3], wherein the parameter H, determined as follows, satisfies 140 <H <350.

H = {491x [Fe ²⁺ ] + 54.8x [Fe ³⁺ ] -17.2x [SnO ₂ ] -45, 2x [CeO ₂ ] + 130x [SO ₃ ] 0.39Ox [CoO] + 0.608x [ Se] -3.95} x [Thickness] where [Fe ²⁺ ] is the Fe ²⁺ content in terms of Fe2O3 in wt%, [Fe ³⁺ ] is the content of Fe ³⁺ in terms of Fe2O ₃ in wt .%, [SnO ₂ ] is the total tin content in terms of SnO ₂ in wt%, [CeO ₂ ] is the total cerium content in terms of CeO ₂ in wt%, [SO3] is the total sulfur in expressed as SO3 in wt%, [CoO] is the total cobalt content in terms of CeO in ppm w / w, [Se] is the total selenium in ppm w / w and [Thickness] is the thickness thick glass in mm.

[5] Soda lime glass plate according to any of the above [1] to [4], wherein the parameter Σ defined as follows satisfies Σ <25,

where [CoO] is the total cobalt content in terms of CoO in ppm by weight and [MgO] is the MgO content in wt%.

[6] Soda lime glass plate according to any of the above [1] to [5] having an ultraviolet transmittance Tuv defined in ISO-9050: 2003 of 35% or less as a converted value for thick plate glass with a thickness of 3.84 mm.

[7] Soda lime glass plate according to any one of the above [1] to [6], having a total cerium content in terms of CeO _{2 of} 0.1-2.0 wt% based on oxides.

[8] Soda lime glass plate according to any of the above [1] to [7], having a total titanium content in terms of TiO _{2 of} 0.001-0.8 wt% based on oxides.

[9] Soda lime glass plate according to any of the above [1] - [8], containing in wt.% Based on oxides:

SiO2: 65-78%;

AW 0-5%;

CaO: 5-12%;

MgO: 0-10%;

Na ₂ O: 5-18%; and

K ₂ O: 0-5%.

[10] Soda lime glass plate according to any of the above [1] to [9], having a coordinate in L * a * b * color space, as defined in JIS Z8781-4: 2013, which satisfies the following relationships as a converted value for thick sheet glass with a thickness of 3.85 mm,

-4 <a * <1, and

-1 <b * <4.

[11] Soda lime glass plate according to any of the above [1] to [10], having:

the conventional background color purity Pe defined in JIS Z8701: 1999, 2.5% or less, as the converted value for 3.85 mm thick plate glass; and the dominant transmitted light wavelength Dw defined in JIS Z8701: 1999, 485 nm-565 nm, as a converted value for 3.85 mm thick plate glass.

[12] Soda lime glass plate according to any of the above [1] to [11], having a direct sunlight transmittance Te, defined in ISO-13837A: 2008, 66% or less, as a converted value for thick plate glass with a thickness of 3, 85 mm.

Benefits of the invention

According to embodiments of the invention, a soda lime glass plate having high thermal insulation property and high visible light transmittance and having a gray color can be provided, thereby preventing an amber yellow color while preventing bubbles by the action of a clarifying agent.

Description of Embodiments

The terms used in the present description are described. Unless otherwise indicated, the definitions of the terms proposed below apply throughout this specification and claims.

- 2 037710

An expression (value) - (value) indicating a numerical range means that the first value and the second value are included as the lower limit and the upper limit, respectively.

The total iron content is indicated by the amount of Fe2O ₃ . All of the iron present in the glass is not always present as ferric iron (Fe ³⁺ ), while ferrous iron (Fe2 ⁺ ) is also present. Mass fraction (percentage) of ferrous iron in terms of Fe2O ₃ in total iron in terms of Fe2O ₃ is called Fe-Redox (Fe-redox).

Fe-redox is calculated using the following formula:

Fe-redox (%) = (0.048bhatz ₄₀ nm-0.0175) / [Fe ₂ O ₃ ]

In the formula a, _1140nm is the absorption coefficient (unit: cm ^-1 ) at a wavelength of 1140nm and [Fe ₂ O ₃ ] is the total iron content (unit: wt%) calculated as Fe ₂ O ₃ .

Likewise, total sulfur, total cobalt, total tin, total cerium, and total titanium are indicated by SO3, CoO, SnO ₂ , CeO _2, and TiO _2, respectively.

The visible light transmittance Tv_A is the visible light transmittance determined by measuring the transmittance with a spectrophotometer in accordance with JIS R3106: 1998. The pre-calculated weighing functions use the values of the standard light source A and at a spatial viewing angle of 2 °. In the present specification, the visible light transmittance is indicated by the converted value for a 3.85 mm thick sheet.

A converted value for a 3.85 mm thick plate used herein means a value obtained by measuring the refractive index of a thick plate of glass whose transmittance has been measured and converting the value of a thick glass sheet (visible light transmittance Tv_A) to a value in terms of the thickness of the thick sheet 3.85 mm, based on the reflectivity of the plate glass, calculated from the refractive index using the Cauchy formula, taking into account multiple reflections.

Total solar transmittance Tts is specified in ISO-13837: 2008 Method A. In this specification, total solar transmittance Tts is indicated as a converted value for a 3.85 mm thick plate.

The direct transmission Te of sunlight is specified in ISO-13837A: 2008. In the present specification, direct sunlight transmission is indicated as a converted value for a 3.85 mm thick plate.

Ultraviolet transmittance Tuv is the ultraviolet transmittance determined by measuring the transmittance with a spectrophotometer in accordance with ISO-9050: 2003. In the present description, the UV transmission is indicated by the converted value for a thick plate with a thickness of 3.85 mm.

Skin damage factor (SDF) is one measure of the cut-off ultraviolet spectrum and is specified in ISO-9050: 2003. As used herein, SDF is indicated as a converted value for a 3.85 mm thick plate.

L * a * b * color space based on the standard specified in JIS Z8781-4: 2013 (using D65 standard light source and 2 ° spatial angle of view). The X, Y and Z coordinates (XYZ color system) are determined from the transmission spectrum of the glass sample and can be converted to the a * b * coordinate. c * is obtained from the following formula:

c * = {(a *) ² + (b *) ² } ^1/2

The limit value decreases with decreasing c *. Those. the glass turns gray. In the present specification, c * is a converted value for a 3.85 mm thick plate.

Pe is the conditional background clarity determined in accordance with JIS Z8701: 1999. In the present description, the conditional background color purity is indicated by the converted value for a thick sheet with a thickness of 3.85 mm.

The dominant transmitted light wavelength Dw is the dominant transmitted light wavelength determined in accordance with JIS Z8701: 1999. In the present description, the dominant wavelength is indicated by the converted value for a thick plate with a thickness of 3.85 mm.

Soda lime glass means glass containing SiO ₂ as the main component, and additionally containing Na 2 O and CaO, as is usually understood by those skilled in the art. Each component and property of a soda lime glass according to an embodiment of the present invention is described below.

The soda lime glass plate according to an embodiment of the present invention contains iron (Fe). Iron has the ability to reduce Tts and Tv_A and also acts as a blue, green or yellow coloring agent. Vehicle window panes need to have a low Tts, but it is not desirable for Tv_A to decrease or coloration to occur. Therefore, it was usually difficult to find the optimal range of Fe content, taking into account the balance with other components and other factors.

In the soda lime glass plate according to an embodiment of the present invention, the total iron content (hereinafter referred to simply as Fe ₂ O ₃ ) in terms of Fe ₂ O ₃ is

- 3 037710

0.15-0.4% by weight based on oxides. When Fe2O ₃ content is 0.15% or more, Tts can be sufficiently reduced. Fe2O ₃ content is preferably 0.2% or more, more preferably 0.22% or more, and still more preferably 0.24% or more. On the other hand, when the Fe ₂ O ₃ content is 0.4% or less, the Tv_A can be increased sufficiently. The content of Fe ₂ O ₃ is preferably 0.37% or less, more preferably 0.35% or less, even more preferably 0.32% or less, even more preferably 0.3% or less, particularly preferably 0.28% or less and most preferably 0.25% or less.

Fe redox affects Tts as described above and is also associated with an amber yellow color. Usually it was difficult to determine the optimal Fe-redox considering the balance with the amount of Fe ₂ O ₃ , the amount of SO3 described below, and other elements.

Fe-redox in soda lime glass plate according to an embodiment of the present invention is 45-70%. When the Fe-redox is 45% or more, the Tts can be sufficiently reduced. Fe-redox is preferably 47% or more, more preferably 49% or more, even more preferably 51% or more, even more preferably 53% or more, particularly preferably 55% or more, and most preferably 57% or more. On the other hand, when the Fe-redox is 70% or less, the glass melting step is not complicated and it is difficult to obtain an amber-yellow color by sulfur reduction. Fe-redox is preferably 67% or less, more preferably 64% or less, even more preferably 63% or less, particularly preferably 61% or less. Those skilled in the art will understand that Fe-redox can be controlled, for example, by adjusting the amounts of reducing agent or oxidizing agent added.

The soda lime glass plate according to an embodiment of the present invention contains sulfur (S). Sulfur is mainly obtained from a salt lump (Na ₂ SO ₄ ) used as a clarifier.

In the soda lime glass plate according to an embodiment of the present invention, the total sulfur (hereinafter simply referred to as SO3) content in terms of SO3 is 0.0010.2% by weight based on oxides. When the SO3 content is 0.001% or more, the brightening effect during glass melting is improved and bubble formation is reduced. The SO3 content is preferably 0.003% or more, more preferably 0.01% or more, and even more preferably 0.02% or more. When the SO ₃ content is 0.2% or less, amber-yellow coloration is sufficiently prevented. The SO ₃ content is preferably 0.1% or less, more preferably 0.05% or less, and even more preferably 0.03% or more.

Soda lime glass according to an embodiment of the present invention contains a tin (Sn) component for the purpose of preventing amber staining and refining. Sn acts as an oxidizing agent and therefore helps to correct Fe-redox. In the soda lime glass plate according to an embodiment of the present invention, the total tin (hereinafter referred to as SnO ₂ ) content in terms of SnO ₂ is 0.02-1% by weight based on oxides. When the SnO2 content is 0.02% or more, amber-yellow color is prevented and the brightening property is satisfactory. The content of SnO ₂ is preferably 0.1% or more, more preferably 0.15 or more, even more preferably 0.2% or more, and particularly preferably 0.3% or more. When the SnO ₂ content is 1% or less, the cost of the raw material can be reduced and the evaporation in the production line can be reduced. The SnO ₂ content is preferably 0.7% or less, more preferably 0.5 or less, even more preferably 0.45% or less, and particularly preferably 0.4% or less.

Soda lime glass plate according to an embodiment of the present invention may contain selenium (Se). Se is a red coloring component and is a Pe-reducing component. Along with this, Se has the ability to reduce c * in soda lime glass plate according to the embodiment,

In soda lime glass according to an embodiment of the present invention, the Se content is preferably 5 ppm or more by mass (0.0005 or more in mass%), more preferably 6 ppm or more, even more preferably 7 h ./million or more, more preferably 8 ppm or more, and particularly preferably 10 ppm or more. Excessive addition of Se leads to the possibility of decreasing Tv_A, described below, and is not preferable from a cost point of view. The Se content is preferably 20 ppm or less, more preferably 17 ppm or less, even more preferably 15 ppm or less, and particularly preferably 14 ppm or less.

The soda lime glass plate according to an embodiment of the invention may contain cobalt (Co) in addition to selenium. Co is a blue coloring component, and has the ability to reduce c * and Pe together with Se. It has been found that adjusting the added amounts of Se and Co over an extremely narrow range in combination with Fe ₂ O _{3 is} particularly beneficial in reducing c * while maintaining high thermal insulation property and visible light transmission.

In a soda lime glass plate according to an embodiment of the present invention, when Co is added, the content of total cobalt (hereinafter simply referred to as CoO) in terms of

- 4037710 on CoO is preferably 2 ppm or more by weight based on oxides (0.0002% or more in weight%), more preferably 3 ppm or more and even more preferably 4 ppm or more. When CoO is added excessively, there is a possibility that the Tv is reduced, and the glass may turn blue. The CoO content is preferably 15 ppm or less, more preferably 10 ppm or less, even more preferably 8 ppm or less, even more preferably 6 ppm or less, and particularly preferably 5 ppm or less.

Soda lime glass plate according to an embodiment of the present invention may contain cerium (Ce). Cerium provides the effect of reducing the transmission of ultraviolet radiation.

In soda lime glass according to an embodiment of the present invention, the content of total cerium (hereinafter simply referred to as CeO ₂ ) in terms of CeO ₂ is preferably 0.1% or more, more preferably 0.15% or more, even more preferably 0.25 % or more, and particularly preferably 0.3% or more in mass% based on oxides. Ce is expensive and when the amount is too large, visible light transmission is reduced. Therefore, the CeO ₂ content is preferably 2.0% or less, more preferably 1.0% or less, even more preferably 0.5% or less, and particularly preferably 0.4% or less.

The soda lime glass plate according to an embodiment of the present invention may contain titanium (Ti). Ti provides an ultraviolet absorption effect similar to cerium, but the absorption rate of ultraviolet rays is lower than that of cerium, and Ti is inexpensive compared to cerium.

In soda lime glass according to an embodiment of the present invention, the content of total titanium (hereinafter referred to simply as TiO2) in terms of CeO2 is preferably 0.001% or more, more preferably 0.002% or more, and even more preferably 0.01% or more by weight .% based on oxides. Ti not only absorbs ultraviolet rays but also visible light. Therefore, its content is preferably 0.8% or less, more preferably 0.1% or less, still more preferably 0.05% or less, and particularly preferably 0.02% or less.

The soda lime glass plate according to an embodiment of the present invention may further comprise coloring component (s) such as MnO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , NiO and Er ₂ O ₃ in addition to the above components, but may or may not contain coloring components. The soda lime glass plate according to an embodiment of the present invention is substantially free of MnO ₂ , MnO, Cr ₂ O ₃ , V ₂ O ₅ , NiO, and Er ₂ O ₃ (unless they are contained as unavoidable impurities). In the present description, the term essentially does not mean that the total content of MnO ₂ and MnO is 0.0015 wt% or less (preferably 0.0005 wt% or less), the content of Cr ₂ O ₃ and NiO is 0.0015 wt % or less (preferably 0.001% or less) and more preferably 0.0005% or less), respectively, the content of V2O5 is 0.01 mass% or less (preferably 0.005% or less and more preferably 0.003% or less), and the Er ₂ O ₃ content is 0.008 mass% or less (preferably 0.005% or less, and more preferably 0.003% or less).

The soda lime glass plate according to an embodiment of the present invention preferably contains, in wt%, based on oxides:

SiO ₂ : 65-78%;

Al ₂ O ₃ : 0-5%;

CaO: 5-12%;

MgO: 0-10%;

Na2O: 5-18%; and

K2O: 0-5%.

SiO2 is the main component of soda lime glass.

When the SiO2 content is 65% or more, the weather resistance is improved, which is preferable. The SiO ₂ content is preferably 67% or more, more preferably 68% or more, even more preferably 69% or more, and particularly preferably 70% or more. When the SiO ₂ content is 78% or less, devitrification, which is preferable, is difficult to perform. The SiO ₂ content is preferably 77% or less, more preferably 76% or less, even more preferably 75% or less, particularly preferably 74% or less, and most preferably 72% or less.

Al2O3 is a weatherproofing component.

The Al2O3 content is 0% or more. When Al2O3 is contained, the weather resistance is improved. The Al2O3 content is preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.3% or more, particularly preferably 0.4% or more, and most preferably 0.5% or more. When the Al2O3 content is 5% or less, fusibility is improved, which is preferable. The Al2O3 content is preferably 4% or less, more preferably 3.5% or less, more preferably 2% or less, particularly preferably 1.3% or less, and most preferably 1% or less.

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CaO is a component that helps to melt glass raw materials and improve weatherability.

When the CaO content is 5% or more, fusibility and weatherability are improved, which is preferable. The CaO content is preferably 6% or more, more preferably 7% or more, even more preferably 8% or more, particularly preferably 8.5% or more, and most preferably 9% or more. When the CaO content is 12% or less, devitrification, which is desirable, is difficult to perform. The CaO content is preferably 11.5% or less, and more preferably 11% or less.

MgO is a component that helps to melt glass raw materials and improve weatherability.

The MgO content is 0 or more. When MgO is contained, fusibility and weatherability are improved. The MgO content is preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.3% or more, and particularly preferably 0.5% or more. When the MgO content is preferably 10% or less, devitrification, which is desired, is difficult to perform. The MgO content is preferably 8% or less, more preferably 6% or less, even more preferably 4% or less, particularly preferably 2% or less, and most preferably 1% or less.

Na ₂ O is a component that helps to melt glass raw materials.

When the Na ₂ O content is 5% or more, fusibility is improved, which is desirable. The Na ₂ O content is preferably 8% or more, more preferably 11% or more, even more preferably 13% or more, and particularly preferably 13.5% or more. When the Na ₂ O content is 18% or less, the weatherability is improved, which is preferable. The Na2O content is preferably 16% or less, more preferably 15 or less, even more preferably 14% or less, and particularly preferably 13.8% or less.

K2O is a melting component for glass raw materials.

The K ₂ O content is 0% or more. When K ₂ O is contained, fusibility is improved. The content of K2O is preferably 0.05% or more, more preferably 0.1% or more, and even more preferably 0.15% or more. When the K2O content is 5% or less, the weather resistance is improved, which is preferable. The content of K ₂ O is preferably 3% or less, more preferably 2% or less, even more preferably 1.5% or less, particularly preferably 1% or less, and particularly preferably 0.5% or less.

The visible light transmittance Tv_A of the soda lime glass according to an embodiment of the present invention is 70% or more as a converted value for 3.85 mm thick plate glass. Preferably, Tv_A is 71% or more, more preferably 72% or more, as a converted value for 3.85 mm thick plate glass.

The soda lime glass according to the embodiment has a total solar transmittance Tts of 63.7% or less as a converted value for thick plate glass with a thickness of 3.85 mm, and therefore has a high thermal insulation property. The Tts is preferably 63.5 or less, more preferably 63.0 or less, even more preferably 62.0% or less, and particularly preferably 61.0% or less.

The direct sunlight transmission Te of soda lime glass according to an embodiment of the present invention is preferably 66% or less, more preferably 60% or less, even more preferably 55% or less, even more preferably 52% or less, and particularly preferably 50% or less. as converted value for 3.85 mm thick plate glass.

Vehicle windshields play the role of protecting human bodies and devices in vehicles from ultraviolet rays. The ultraviolet transmittance Tuv of the soda lime plate glass according to an embodiment of the present invention is preferably 35% or less, more preferably 33% or less, even more preferably 32% or less, and particularly preferably 31% or less, as a converted value for 3.85 mm thick plate glass. ...

The skin damage factor (SDF) of the soda lime glass according to an embodiment of the present invention is preferably 10% or less. SDF is more preferably 9% or less, even more preferably 8% or less, and particularly preferably 7% or less.

Soda lime glass according to an embodiment of the present invention has a c * in L * a * b * color space of 4 or less as a converted value for 3.85 mm thick plate glass. Therefore, soda lime glass is gray with reduced stains in blue, green and amber yellow. The glass easily looks gray because c * is small. c * is preferably 3.8 or less, more preferably 3.6 or less, and particularly preferably 3.5 or less.

a * is preferably -4-1, as the converted value for heavy plate glass

- 6 037710 3.85 mm thick. a * may be 3.9 or more and may be -3.8 or more. In addition, a * may be 0 or less, may be -1 or less, and may be -2 or less.

b * is preferably -1-4, as the converted value for 3.85 mm thick plate glass. b * may be -0.5 or more, and may be 0 or more, In addition, b * may be 3 or less, may be 2.5 or less, and may be 2 or less.

It is particularly preferable that a * is between -4-1 and b * is between -1-4, as the converted value for thick plate glass with a thickness of 3.85 mm.

The nominal color purity Pe of the soda lime heavy plate according to an embodiment of the present invention is preferably 2.5% or less as a converted value for 3.84 mm thick plate glass. Pe is more preferably 2.0% or less, even more preferably 1.7% or less, and particularly preferably 1.5 or less.

The dominant wavelength Dw of light transmitted by the soda lime glass according to an embodiment of the present invention is preferably 485 nm565 nm as a converted value for 3.85 mm thick plate glass. The Dw is more preferably 490 nm or more, even more preferably 495 nm or more, and particularly preferably 500 nm or more. In addition, the Dw is more preferably 550 nm or less, even more preferably 530 nm or less, and particularly preferably 510 nm.

In an embodiment of the present invention, in order to obtain a thick glass having a desired gray color, the parameter determined by n = Tv_Axc * is preferably 350 or less. Even in the case where c * is large, it is easy for thick glass to look gray because Tv_A is small. This is due to the subjectivity of the person. P is more preferably 330 or less, more preferably 310 or less, and particularly preferably 300 or less.

It is easy for heavy-plate glass to look gray because the area is small. This is due to the subjectivity of the person. The reason for this is that the area around the thick glass is easy to see because the area of the thick glass is small and both the surrounding area and the glass are visible, and as a result, it is difficult to recognize the color of the glass. The major surface area of the glass plate is preferably 4 m ² or less. When the area of the glass plate is 4 m ² or less, the plate glass still looks gray. The area of the glass is more preferably 3 m ² or less, even more preferably 2.5 m ² or less, and particularly preferably 2 m ² or less.

In an embodiment of the present inventions, in order to obtain a thick plate glass having the desired visible light transmittance, total solar transmittance, ultraviolet transmittance, gray color, and lightening property in a good balance, it is preferable to adjust the parameter H determined as follows to satisfy requirement 140 <H <350.

H = {491x [Fe ²⁺ ] + 54.8x [Fe ³⁺ ] -17.2x [SnO ₂ ] -4 5, 2x [CeO ₂ ] + 130x [SO ₃ ] 0.390x [CoO] + 0.608x [ Se] -3.95} x [Thickness]

In the above formula, [Fe ²⁺ ] is the Fe ²⁺ content based on Fe2O3 in wt%, [Fe ³⁺ ] is the Fe ³⁺ content based on Fe2O ₃ in wt%, [SnO ₂ ] is the total tin content in terms of SnO ₂ in wt%, [CeO ₂ ] is the total content of cerium in terms of CeO ₂ in wt%, [SO3] is the total sulfur content in terms of SO3 in wt%, [ CoO] is the total cobalt content in terms of CoO in ppm by weight, [Se] is the total selenium in ppm by weight and [Thickness] is the thickness of the plate glass in mm.

The parameter H is preferably 150 or more, more preferably 160 or more, and particularly preferably 170 or more. The parameter H is more preferably 330 or less, even more preferably 320 or less, and particularly preferably 310 or less.

In an embodiment of the present invention, in order to obtain a thick glass having a small c * and a desired gray color, it is preferable to adjust the parameter Σ determined as follows to satisfy the requirement Σ <25.

Σ = [CoO] + 6.4x [MgO]

In the above formula, [CoO] represents the total cobalt content in terms of CoO in ppm by mass, and [MgO] represents the MgO content in mass%.

The parameter Σ is more preferably 24 or less, more preferably 20 or less, particularly preferably 18 or less, and most preferably 16 or less.

The soda lime glass plate according to an embodiment of the present invention can be produced by conventional methods known to those skilled in the art. For example, soda lime glass thick can be produced by preparing glass raw materials so as to have the above-described final composition, melt

- 7,037710 pouring these raw materials at 1400-1550 ° C in a melting furnace to produce molten glass, as well as molding molten glass.

Examples of

An embodiment of the invention is specifically described below with reference to examples, but the present invention is not to be construed as limited to these examples.

Cases 1-30 and 38-51 are examples, and cases 31-37 and 52 are comparative examples. Cases 31, 32 33 correspond to Cases 2, 4, and 6 described in Patent Literature 1, respectively.

The raw materials were placed in a platinum crucible so as to have the corresponding glass compositions shown in table. 1-4 below, and melted at 1550 ° C. for 2 hours. Each thus obtained melt was poured onto a graphite plate and gradually cooled, thereby producing a thick soda lime glass sheet. Both sides of the thick plate were polished to obtain a plate glass having a thickness of 3.85 mm.

Omitting in the tables means that the component is essentially not contained.

Table 1

Case th one Case th 2 Case th 3 Case th four Case th five Case th 6 Case th 7 Case th eight Case th nine Happening 10 Happening eleven Happening 12 Happening 13 Happening fourteen Happening fifteen SiO ₂ (wt.%) 69.7 69.6 69.6 69.6 69.5 69.5 69.4 69.5 69.5 6 1.5 69.4 69.5 69.5 69.5 69.5 A1 ₂ O ₃ (wt%) 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3 , five 3 , five , five 3.5 3.4 3.5 3.5 MDO (wt%) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0 , 3 0 , 3 , 3 0.3 0.3 0.3 0.3 CaO (wt%) 9.6 9.6 9.6 9.6 9.6 9.6 9.6 9.6 nine , 6 nine , 6 , 6 9.6 9.6 9.6 9, 6 Na ₂ O (wt%) 14.6 14.6 14.7 14.6 14.6 14.6 14.6 14.7 one 4.7 B 1.7 14.8 14.7 14.7 14.7 14.7 K ₂ O (wt%) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 one , five one , five , five 1.5 1.5 1.5 1.5 Fe ₂ O ₃ (wt.%) 0.253 0.252 0.226 0.225 0.224 , 226 0 , 245 0 244 0245 0, 244 0, 244 0 , 245 0.244 0.245 0.245 Tyu ₂ (wt%) 0.002 0.001 0.002 0.001 0 , 002 0 , 001 0 001 0, 001 0, 001 0, 001 0 , 001 0 0.002 0.001 SnO ₂ (wt%) 0.19 0.19 0.19 0, 19 0.34 0.35 035 0 , 33 0 34 0 33 0 , 35 ), 34 0.34 0.34 0.35 СеО ₂ (wt.%) 0.42 0.42 0.44 0.44 0.44 0.44 0.44 0 , 34 0 , 34 0 34 0 , 34 ), 34 0.34 0.30 0.30 SO ₃ (wt%) 0.020 0.021 0.019 0.020 0.022 , 022 0 , 021 0 017 0, 001 about, 001 0, 010 0 , 001 0.002 0.001 0.001 CoO (ppm by 8.6 7.1 5.5 6, 0 7.1 7.0 6, 6 5.0 five , 6 6 , 2 , h 5.6 5.9 6.2 6, 3 mass) Se (ppm by 8.3 6, 0 8.6 10.1 10.9 10.5 11.2 13.4 one 4.2 one. 3.6 13.6 -4.7 14.7 13.4 12.7 mass) Fe-redox (%) Tv_A (JIS 48.8 58.3 60.6 59.9 60.8 60.0 51.2 6 1.5 6 1.1 6 1.8 6 0.7 31.1 59.4 59.6 58.2 72.8 71.1 72.5 70.9 73.0 72.8 71, eight 71, five 70 0 70, 3 70, four 70.4 70.4 70.0 70.1 R3106: 1998) (%) Those (ISO- 52.7 48.9 50.6 49.9 51.2 51,: 48, nine 48, eight 48 one 48, four 48, four 48.3 48.7 48.4 48.8 13837A: 2008) (%) Tts (ISO- 13837: 2008, 63.5 60.8 62.0 61.5 62.4 62.4 60, eight 60, 7 60 2 60, four 60, four 60.3 60,7 60.4 60,7 Method A) (%) Tuv (ISO-9050- 32.1 31.2 31.1 30.0 31.6 31.5 31, 2 32, eight 32 one 32, 6 32, 3 32.5 32.4 32.2 31.9 2003) (%) SDF (ISO- 7.5 7.3 7.2 7.0 7.4 7.3 7.2 7, 7, five 7, 6 7.5 7.6 7.6 7.5 7.4 9050: 2003) (%) L * (D65) 85.8 84.9 85.5 84.7 85.9 85, 85, 2 85, one 84 four 84, 6 84, 6 84.6 84.6 84.4 84.5 a * (D65) -3.3 -3.7 -3.8 -3.4 -3.6 -3.6 -four, 0 -z, nine -z, 3 -z, 2 -z, five -3.4 -3.1 -3.3 -3.2 b * (D65) 0.3 0.7 1.1 2.0 -0.2 -0.1 0.3 about, 7 about, 2 about, one 0,4 0.0 0.3 0,4 0,4 c * (D65) 3.4 3.8 3.9 3.9 3.6 3.6 4.0 h, nine h, 3 h, 2 3.5 3.4 3.1 3.3 3.2 Dw (nm) 498 501 506 537 495 495 497 501 497 496 498 495 498 498 499 Pe (%) 1.6 1.5 1,2 1,3 2.1 2.0 2.0 one, five one, 7 one, 7 1Λ 1.9 1.5 1.5 1.4 Parameter H 176 213 195 195 188 186 216 240 231 232 232 232 224 229 221 Parameter Σ 10.6 9.1 7.5 8.0 9, 1 9.0 8.6 6, 7 7, four 7, nine 7.1 7.4 7,7 8.2 8.2 Parameter Π 245 267 284 276 264 259 287 280 231 228 245 236 219 230 223

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table 2

Case 16 Case th 17 Case th eighteen Case th nineteen Case th twenty Case th 21 Case th 22 Case th 23 Case th 24 Case 25 Case 26 Case th 27 Case th 28 Case th 29 Case 30 SiO ₂ (wt.%) 69.5 69.5 69.4 69.5 69.5 69.5 69.4 69.4 69.5 69.6 70.6 72.8 70.8 69.7 69.6 A1 ₂ O ₃ (wt%) 3.5 3.4 3.4 3.4 3.4 3.5 3.5 3.5 3.5 3.5 1.9 0.6 2.0 3.4 3.5 MDO (wt%) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.8 1.8 0.9 0.6 0.3 CaO (wt%) 9.6 9.6 9.6 9.6 9.6 9.6 9.6 9.6 9.6 9.6 9,7 10.1 10.5 9.2 9.6 Na ₂ O (wt%) 14.7 14.7 14.7 14.7 14.7 14.6 14.7 14.7 14.7 14.7 13.6 13.6 13.4 14.8 14.7 K ₂ O (wt%) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 0.1 1.5 1.5 1.5 Fe ₂ O ₃ (wt.%) 0.247 0.245 0.238 0.208 0.209 0.246 0.226 0.208 0.246 0.245 0.273 0.273 0.313 0.227 0.2 T1O ₂ (wt%) 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.002 0.002 0.001 0.001 0.05 SnO ₂ (wt.%) 0.34 0.34 0.35 0.35 0.35 0.34 0.35 0.35 0.36 0.34 0.20 0.20 0.19 0.19 0.25 СеО ₂ (wt.%) 0.30 0.30 0.39 0.39 0.39 0.33 0.42 0.43 0.33 0.31 0.45 0.47 0.41 0.38 0.1 SO ₃ (wt%) 0.001 0.019 0.020 0.021 0.022 0.020 0.022 0.020 0.021 0.001 0.022 0.020 0.001 0.018 0.002 CoO (ppm by weight) 3.8 9.9 8.8 7.9 8.9 5.9 8.6 14.0 6, 9 3.5 0,4 4.2 4.4 8.8 12.0 Se (ppm by weight) 14.0 12.7 11.1 10.6 12.9 12.7 13.8 13.3 11.4 13.2 7,7 8.3 6.3 8.7 5.2 Fe-redox (%) 59.3 60.4 59.8 59.1 59.7 61.1 63.7 64.0 59.5 58.5 49.1 46.3 48.4 59.9 60 Tv_A (JIS R3106: 1998) (%) 70.8 70.0 71.1 73.3 72.3 71.0 71.1 71.0 71.1 71.0 71.5 71.5 70.8 71.2 71.4 Those (ISO13837A: 2008) (%) 48.6 48.2 49.4 53.0 52.1 48.3 49.4 50.8 48.8 49.0 51.0 52.1 49.2 51.5 51.4 Tts (ISO13837: 2008 Method A) (%) 60.6 60.3 61.1 63.7 63.1 60.4 61.1 62.2 60,7 60.9 62.3 63.1 61.0 62.6 61.8 Tuv (ISO-90502003) (%) 32.2 32.3 31.2 32.3 31.4 32.3 31.3 31.5 32.5 32.0 29.1 29.5 29.9 31.7 36, 8 SDF (ISO9050: 2003) (%) 7.5 7.5 7.3 7.5 7.3 7.5 7.3 7.3 7.6 7.5 6, 8 6, 9 7.0 7.4 8.6 L * (D65) 84.8 84.4 84.9 86, 1 85.5 84.8 84.9 84.9 84.9 84.9 85.0 85.1 84.8 85.0 85.1 a * (D65) -3.3 -3.8 -3.8 -3.4 -3.3 -4.0 -3.6 -3.5 -4.0 -3.2 -2.9 -2.7 -3.4 -3.1 -2.3 b * (D65) 0.7 0.0 -0.3 -0.8 0.0 0.5 0,4 -0.2 -0.2 0.8 2,3 1.7 0.7 0.3 1.1 c * (D65) 3.4 3.8 3.8 3.5 3.3 4.0 3.7 3.5 4.0 3.3 3.7 3.2 3.5 3.1 2.5 Dw (nm) 503 496 494 492 496 499 499 495 495 504 551 542 502 498 522 Re (%) 1,3 2.1 2,3 2.6 1.8 1.8 1.7 2.1 2,3 1,2 1.9 1,3 1,3 1.5 0.7 Parameter H 235 235 206 167 175 240 208 175 229 227 204 184 230 198 190 Parameter Σ 5.7 11.8 10.8 9.9 10.9 7.8 10.5 15.9 8.7 5.4 12.0 15.8 10.2 12.7 13.9 Parameter P 239 267 269 255 238 283 260 250 284 235 263 229 245 223 179

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Table 3

Case 31 Case 32 Case 33 Case 34 Case 35 Case 36 Case 37 SiO ₂ (wt.%) 71.0 70, 9 70.6 70.5 72.1 72.5 73.3-73.9 A1 ₂ O ₃ (wt%) 3.3 3.3 3.3 3.2 0.2 0, 13 0.12-0.16 MDO (wt%) 0, 1 0.1 0.1 oh, 1 3.8 3.8 3.6-3.8 CaO (wt%) 9, 0 9.1 9.5 9.4 8.8 8.8 8.5-8.8 Na ₂ O (wt%) 14.5 14.5 14.4 14.6 13, 6 13.8 13.2-13.6 K ₂ O (wt%) 1.5 1.5 1.5 1.5 0.1 0.031-0.03 four Fe ₂ O ₃ (wt.%) 0.36 0.36 0.35 0.39 0.366 0.65 0.46 TiO ₂ (wt%) 0.021 0.1 ZnO ₂ (wt.%) 0.21 0.21 0.21 0.2 СеО ₂ (wt.%) 0.3 SO ₃ (wt%) 0.003 0, 003 0.016 0.02 0.079 CoO (ppm by weight) 2 2 nine 25 0 twenty twenty Ze (ppm by weight) 6 3 3 nine five 3.5 five Fe-redox (%) 56 59 61 64 50.3 thirty (47.9) Tv_A (JIS R3106: 1998) (%) 70.4 73.2 71.6 58.1 72.5 66.4 65, 1 Those (ISO-13837A: 2008) (%) 45.4 46.4 45.5 32.3 49.5 45.6 42.9 Tts (130-13837: 2008, Method A) (%) 58.2 59, 0 58.3 48.7 61.2 58.4 56.4 Tuv (ISO-9050-2003) (%) 42.3 47 48 37.5 38.3 30.8 28.3 SDF (130-9050: 2003) (%) 10.4 11, 6 11.9 9, 1 11, 1 7.4 6, 7 L * (D65) 84.5 85, 9 85.3 81.5 85.5 82.6 82 a * (D65) -3, 8 -5.1 -5.2 -5.2 -4.3 -5.7 -5.6 b * (D65) 1,2 -1.7 -2.9 -1.7 0.6 -1.6 -2.6 c * (D65) 4.1 5.4 5.9 5.5 4.4 5.9 6, 1 Dw (nm) 508 490 489 490 500 492 489 Pe (%) 1,2 4.3 5.3 4.8 1.8 4.5 5.5 Parameter H 398 409 405 483 411 449 400 Parameter Σ 2.6 2.6 9.6 25.6 24.3 44.3 43, 0 Parameter Π 289 395 422 320 319 392 397

Table 4

Case 38 Case 39 Case 40 Case 4 1 Case 42 Case 43 Case 44 Case 45 Case 46 Case 47 Case 48 Case 49 Case 50 Case 51 Case 52 SiO ₂ (wt.%) 71.0 72.7 70.9 70, 8 73.1 71.2 71.1 71.1 71.0 71.0 71.1 71.3 71.1 70.5 70.9 A1 ₂ O ₃ (wt%) 2.0 1.0 2.0 2.2 1.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 1.0 MDO (wt%) 0.7 0.1 0.8 1.8 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0,4 0,4 CaO (wt%) 10.6 10.7 10.5 9.3 10.7 10.6 10.7 10.7 10.7 10.7 10.6 10.6 10.6 10.6 10.6 Na ₂ O (wt%) 13.6 14.4 15.2 14, 1 14.3 14.7 14.7 14.7 14.7 14.8 14.7 14.6 14.7 14.0 14.0 K ₂ O (wt%) 1.5 0.2 0.0 0.8 0.2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1.4 1.4 Fe ₂ O ₃ (wt.%) 0.240 0.290 0.240 0.240 0.290 0.270 0.300 0.300 0.297 0.272 0.274 0.273 0.274 0.220 0.200 T1O ₂ (wt%) 0.010 0.010 0.010 0.010 0.010 0.002 0.002 0.001 0.001 0.001 0.001 0.001 0.001 0.010 0.010 SnO ₂ (wt.%) 0.33 0.36 0.08 0.34 0.19 0.19 0.19 0.19 0.19 0.18 0.19 0.19 0.19 0.400 0.800 СеО ₂ (wt.%) 0.27 0.16 0.26 0.33 0.00 0.42 0.40 0.40 0.49 0.50 0.45 0.50 0.50 0.450 0.700 SO ₃ (wt%) 0.001 0.049 0.015 0.001 0.050 0.014 0.019 0.020 0.023 0.017 0.018 0.013 0.016 0.03 0.01 CoO (ppm by weight) 0.0 3.9 2.0 5.3 4.3 3.8 3.6 3.4 3.0 2.4 3.3 3.1 4.1 5.0 6, 0 Ze (ppm by weight) 14.0 6, 6 5.3 12.1 6, 6 7.6 6, 8 6, 1 6, 8 7.8 7.0 7.2 7.0 5.0 16, 0 Fe-redox (%) 54.0 50.9 47.1 67.0 61.2 65.9 58.7 60.1 56.3 61.3 64.1 66, 0 64.9 54.5 85.0

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Tv_A (JIS R3106: 1998) (%) 73.0 73.5 73,7 71.8 72.8 71.7 71.4 71.8 71.6 71.4 72.0 71.7 72.0 73.6 67.9 Those (ISO13837A: 2008) (%) 50.2 51.3 52.8 50.3 51.8 49.0 49.4 49.2 49.4 49.6 49.7 49.0 49.5 50.1 42.5 Tts (ISO13837: 2008 Method A) (%) 61.7 62.5 63.6 61.8 62.8 60.9 61.1 61.0 61.1 61.3 61.4 60.8 61.2 61.6 56, 1 Tuv (ISO-90502003) (%) 33.6 35.0 33,7 33.5 46.4 29.6 29.5 29.7 28.1 28.0 29.4 28.4 28.8 28.0 27.0 SDF (ISO9050: 2003) (%) 7.8 8.3 7.8 7.8 11.7 6, 9 6, 9 7.0 6, 6 6, 6 6, 9 6, 7 6, 8 6, 6 6, 4 L * (D65) 85.8 86, 0 86, 1 85.3 88.7 85.1 85.0 85.2 85.1 85.0 85.3 85.1 85.3 89.0 86.5 a * (D65) -3.2 -3.9 -3.7 -3.8 -2.7 -3.5 -3.1 -3.4 -3.1 -3.0 -3.3 -3.4 -3.2 -2.7 -3.9 b * (D65) 1.1 0.0 0.6 -0.2 0,4 1.1 1.1 0.6 1.4 1.9 1,3 1.5 0.8 -0.2 -3.3 c * (D65) 3.4 3.9 3.8 3.8 2.7 3.7 3.3 3.5 3.4 3.6 3.5 3.7 3.3 2.7 5.1 Dw (nm) 511 496 500 495 503 509 512 501 519 540 515 518 504 508 489 Re (%) 1.0 2.1 1.5 2,3 1,2 1.1 0.9 1.4 0.9 1,3 1.0 1.0 1.1 0.9 4.0 Parameter H 196 241 178 220 336 244 252 258 226 218 237 234 230 147 135 Parameter Σ 4.5 4.3 7.1 16, 8 4.9 4.2 4.0 3.8 3.4 2.8 3.7 3.5 4.5 7.6 8.6 Parameter P 248 287 280 271 197 263 235 250 242 256 252 268 241 199 344

The X-ray intensity of each component on the surface of the plate glass obtained above was measured using an X-ray fluorescence spectrometer (XRF, X-ray fluorescence) (ZSX100e manufactured by Rigaku Corporation), quantitatively analyzed, and the above compositions were confirmed. In addition, the transmittance was measured at each 1 nm using a spectrophotometer (Lambda 950 manufactured by Perkin Elmer) and Fe-redox was determined from the transmittance at 1150 nm. The amount of divalent iron, determined from the transmittance at a wavelength of 1150 nm is converted into a mass Fe2O ₃ as described above and used to calculate the Fe-redox. In addition, the optical properties shown in the tables were obtained.

From table. 1 it has been found that soda-lime thick-sheet glasses in cases 1-30 and 38-51 retain high transmittance in the presence of a high thermal insulation property, i.e. total solar transmittance Tts of 63.7% or less, and reaches the gray color represented by c * with a value of 4 or less.

On the other hand, soda lime glass plates in cases 31-37 and 52 meet the criteria for high thermal insulation, but the c * value exceeds 4 and the desired achromatic color is not achieved. In addition, the transmission of visible light (cases 34, 36, 37 and 52), the scattering property of ultraviolet radiation (cases 31-35 and the property of lightening (cases 36 and 37) are insufficient, while the balance of desirable properties is not obtained, as in the window glasses of transport funds.

Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications or changes can be made without departing from the spirit and scope of the present invention. This application is based on Japanese Patent Application No. 2016-206717, filed October 21, 2016, and Japanese Patent Application No. 2017-096950, filed May 16, 2017, the contents of which are incorporated herein by reference.

Industrial applicability

The soda-lime glass of the invention has a high thermal insulation property, visible light transmission and gray color. Consequently, soda lime glass is useful as window panes for vehicles, especially automobiles, and can be used for other applications that require these properties.

Claims (13)

CLAIM 1. Soda-lime thick-plate glass containing, in wt.% Based on oxides: SiO2: 65-78%; CaO: 5-12%; and Na2O: 5-18%, and at the same time having a total sulfur content in terms of SO ₃ 0.001-0.2% in wt.% Based on oxides; - 11 037710 total iron content in terms of Fe2O ₃ 0.15-0.4% in wt.% Based on oxides; the total content of tin in terms of SnO2 0.02-1% in wt.% based on oxides; the mass fraction of ferrous iron in terms of Fe ₂ O ₃ in the total iron in terms of Fe ₂ O ₃ 45-70%; Se content 5-20 ppm by weight; the total content of cerium in terms of CeO ₂ 0.1-2.0% in wt.% based on oxides; visible light transmittance Tv_A defined in JIS R3106: 1998, 70% or more as a converted value for 3.85 mm thick plate glass; total solar transmittance, Tts, determined according to ISO-13837: 2008 Method A, 63.7% or less, as a converted value for 3.85 mm thick plate glass; ultraviolet transmittance Tuv, defined in ISO-9050: 2003, 35% or less, as a converted value for 3.85 mm thick plate glass; and c * in the L * a * b * color space defined in JIS Z8781-4: 2013, 4 or less, as the converted value for 3.85 mm thick plate glass. 2. Soda-lime thick-plate glass according to claim 1, additionally containing in wt.% Based on oxides: Al ₂ O ₃ : up to 5%. 3. Soda-lime thick-plate glass according to claim 1 or 2, additionally containing in wt.% Based on oxides: MgO: up to 10%. 4. Soda-lime thick-plate glass according to any one of claims 1 to 3, additionally containing in wt.% Based on oxides: K2O: up to 5%. 5. Soda lime glass plate according to any one of claims 1 to 4, additionally containing cobalt, wherein the total cobalt content in terms of CoO is up to 15 ppm by weight based on oxides. 6. Soda lime glass plate according to claim 5, in which the parameter H, determined in the following manner, satisfies the relationship 140 <H <350, H = {491x [Fe ²⁺ ] + 54.8x [Fe ³⁺ ] -17.2x [SnO ₂ ] -45.2x [CeO ₂ ] + 130x [SO ₃ ] -0.390x [CoO] + 0.608x [ Se] -3.95} x [Thickness] where [Fe ²⁺ ] is the Fe ²⁺ content in terms of Fe2O3 in wt%, [Fe ³⁺ ] is the content of Fe ³⁺ in terms of Fe2O ₃ in wt .%, [SnO ₂ ] is the total tin content in terms of SnO ₂ in wt%, [CeO ₂ ] is the total cerium content in terms of CeO ₂ in weight%, [SO3] is the total sulfur in expressed as SO3 in wt%, [CoO] is the total cobalt content in terms of CoO in ppm by weight, [Se] is the total selenium in ppm by weight and [Thickness] is the thickness thick glass in mm. 7. Soda lime glass plate according to claim 5 or 6, in which the parameter Σ, defined as follows, satisfies the relationship Σ <25, Σ = [CoO] + 6.4x [MgO] where [CoO] is the total cobalt content in terms of CoO in ppm by weight and [MgO] is the MgO content in wt%. 8. Soda-lime thick-plate glass according to any one of claims 1 to 7, having a total titanium content in terms of TiO ₂ 0.001-0.8% by weight based on oxides. 9. Soda lime glass plate according to any one of claims 1 to 8, having a coordinate in L * a * b * color space defined in JIS Z8781-4: 2013, which satisfies the following relationships as a converted value for thick plate glass 3 , 85 mm, -4 <a * <1 and -1 <b * <4. 10. Soda-lime plate glass according to any one of claims 1 to 9, having a conditional background color purity Pe, defined in JIS Z8701: 1999, 2.5% or less, as a converted value for thick plate glass with a thickness of 3.85 mm; and the dominant transmitted light wavelength Dw defined in JIS Z8701: 1999, 485-565 nm, as a converted value for 3.85 mm thick plate glass. 11. Soda lime glass plate according to any one of claims 1 to 10, having a direct sunlight transmittance Te, defined in ISO-13837A: 2008, 66% or less, as a converted value for plate glass with a thickness of 3.85 mm. 12. Soda lime glass plate according to any one of claims 5-11, having a total cobalt content in terms of CoO 4-15 ppm by weight based on oxides. 13. Soda-lime thick-plate glass according to any one of claims 1-12, having a mass fraction of ferrous iron in terms of Fe2O3 in total iron in terms of Fe2O3 57-70%.