JP2009107850A - Method for producing glass article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a glass article containing NiO, wherein formation of NiS can be suppressed. <P>SOLUTION: The method for producing the glass article includes mixing a nickel oxide-containing glass melt and/or a compression molded product of the glass melt batch as a nickel oxide source with a glass batch containing a sulfur compound and then melting the resulting mixture. The glass melt is preferably adjusted to be a composition comprising, in mass%, 60-80% of SiO<SB>2</SB>, 0-5% of Al<SB>2</SB>O<SB>3</SB>, 0-10% of MgO, 0-15% of CaO, 5-15% of MgO+CaO, 10-18% of Na<SB>2</SB>O, 0-5% of K<SB>2</SB>O, 10-20% of Na<SB>2</SB>O+K<SB>2</SB>O, and 1-15% of NiO. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a glass article, and particularly to a method for manufacturing a glass article containing nickel oxide. In particular, in a method of manufacturing a glass plate formed into a plate shape by a float method or a roll-out method, a manufacturing method that can achieve three things: improvement of glass bubble quality, control of oxidation-reduction conditions, and reduction of NiS generation About.

  Usually, soda lime silica glass is produced by weighing and mixing predetermined raw materials and adding cullet to a melting furnace. The charged raw material is heated from room temperature and heated to a maximum of about 1500 to 1600 ° C. in a melting furnace to be melted and vitrified.

  When producing soda lime silica glass, a sulfate compound (calcium sulfate, sodium sulfate, etc.), which is a sulfur compound, is added to the glass batch in order to promote melting and fining. In particular, sodium sulfate (hereinafter referred to as mirabilite) is generally added. The melting point of mirabilite is 884 ° C., and when this temperature is exceeded, the mirabilite is considered to be in a liquid phase and promote the vitrification reaction.

  In addition, the sulfur compound contained in the glass batch is mainly the above-described sulfate compound. In addition to this, blast furnace slag containing sulfur called calumite (registered trademark) is also cited as a sulfur compound contained in the glass batch.

Furthermore, mirabilite is considered to react with a carbon-based reducing agent (for example, carbon or the like) added together in the glass batch to produce sodium sulfide (Na ₂ S).

Na ₂ S described above reacts with silica (SiO ₂ ) to promote melting of the silica and formation of a glass network, and thus is considered to be an important substance for promoting the vitrification reaction. Sulfide ion (S ²⁻ ) is very unstable in the air, and it is very difficult to directly observe Na ₂ S.

The exact numerical value of the S ²⁻ formation temperature range is not clear and varies depending on the components of the glass batch, but is considered to be in the vicinity of the temperature range of approximately 800 to 1200 ° C.

  Nickel oxide (NiO) has long been used as a yellowish brown to dark purple coloring material in glass compositions. In recent years, it has also been used as a coloring component of glass having a relatively low visible light transmittance, which is used for automobile rear window glass. The NiO component contained in such a low visible light transmittance glass is contained from several tens of ppm to more than 1000 ppm.

By the way, S ²⁻ described above easily reacts to form nickel sulfide (NiS) when nickel oxide (NiO) is present.

In addition to the case where it is used as a coloring raw material, there is a possibility that nickel may be mixed in industrially produced glass articles. For example, metallic nickel is widely used as alloys such as stainless steel and welding rods, and small pieces of these nickel alloys are often mixed into industrial glass raw materials and cullet and may be put into a kiln. It is. Although the melting reaction of the nickel alloy in the kiln is not clear, it is believed that the nickel in the alloy also combines with S ²⁻ described above to form NiS.

Although the NiS generation temperature range is not clear, it is considered to be 800 ° C. or more from the above-mentioned S ²⁻ generation temperature range, and the industrial nickel sulfide generation temperature is about 1000 ° C., so the temperature is 800 to 1200 ° C. Presumed to be in range.

  Further, when the temperature becomes higher than 1300 ° C., NiS once generated is considered to disappear again by melting or diffusing in the glass. It is estimated that the melting rate and the diffusion rate are higher at higher temperatures.

  Now, heat strengthened glass is used as one of safety glasses for automobiles. Thermally tempered windowpanes can break spontaneously, very rarely without the application of particularly large external forces. The heat strengthened glass has a compressive stress layer on the surface and an internal tensile stress layer. In the case where minute foreign matter, particularly nickel sulfide (NiS) is present in this tensile stress layer, the NiS undergoes a transition from the α phase to the β phase with the passage of time. It is known to break glass.

  For this reason, in order not to generate NiS, various glass manufacturing methods are examined.

  Japanese Patent Application Laid-Open No. 49-118711 discloses a glass raw material composition characterized in that a part of the raw material composition component at the time of production of the plate glass is replaced with nitrate and soda ash and does not contain carbon. ing.

  US Pat. No. 5,725,628 discloses a glass characterized by adding a manganese compound at least 1.4 times the nickel content in order to remove nickel sulfide in the production process of soda-lime glass. A manufacturing method is disclosed.

  JP-A-7-144922 discloses a method for producing soda-lime glass, which essentially includes molybdenum, arsenic, antimony, bismuth, copper, silver, potassium dichromate and chromite iron, and combinations thereof. Disclosed is a method for producing glass, characterized in that at least 0.010% by weight of a substance selected from the group consisting of:

  In Japanese Patent Application Laid-Open No. 9-169537, the applicant of the present invention has disclosed a nickel-based compound contained in a glass material and / or a glass that has been melt-formed due to a nickel-based compound mixed in the melting process of the glass material. A method for producing soda-lime-based glass is disclosed in which nickel sulfide produced in the above is suppressed by adding a small amount of a component such as a zinc compound, metal salt or metal oxide to the glass raw material.

  On the other hand, various glass manufacturing methods used as a raw material by adding a glass raw material batch obtained by selectively combining frit glass or a part of batch components and solidifying them are also disclosed.

  Japanese Patent Laid-Open No. 6-1633 discloses that the reduction rate in glass is within a specific range by using a combination of high reduction rate and / or relatively high reduction rate frit glass, specified mirabilite and specified carbon as appropriate. A method of producing infrared ultraviolet absorbing glass by controlling to enter is disclosed.

JP-A-11-116270 discloses a UV-absorbing colorless and transparent soda-lime-silica type, characterized in that a colored frit containing V ₂ O ₅ and a colored frit containing Se are added and stirred and then molded. A method for manufacturing a glass bottle is disclosed.

JP-T-2005-519015 discloses a melting efficiency by selectively combining specific components of a glass batch composition to reduce the gross segregation of the batch components in the glass melt and further control the thermal reaction path. A method of improving is disclosed.
Japanese Patent Laid-Open No. 49-118711 U.S. Pat. No. 5,725,628 JP-A-7-144922 JP 9-169537 A JP-A-6-1633 JP-A-11-116270 JP-T-2005-519015

  Since the glass manufacturing method disclosed in Japanese Patent Application Laid-Open No. 49-118711 has reduced the mirabilite having a glass refining action, bubbles in the glass cannot be completely removed. Moreover, since the carbon which adjusts the redox state of glass is not included, optical characteristics cannot be adjusted. For this reason, for example, it was not possible to obtain the foam quality and optical characteristics required for automobile window glass.

  U.S. Pat. No. 5,725,628 contains a large amount of a manganese compound that acts as a strong oxidant, so that the redox condition of the glass is oxidation, and the optical properties cannot be adjusted. For this reason, for example, the optical characteristic required for the window glass for automobiles could not be obtained.

  The glass manufacturing method disclosed in Japanese Patent Application Laid-Open No. 7-144922 is not based on the premise that the glass batch contains NiO, and is a countermeasure for NiS that is introduced to the glass material only slightly as a contamination. Met. For this reason, for example, it could not be used for NiS countermeasures for glass compositions containing NiO.

  Japanese Patent Application Laid-Open No. 9-169537 also requires the addition of a zinc compound that acts as an oxidizing agent, so that the redox of the glass is caused by oxidation, making it difficult to adjust the optical properties. For this reason, for example, it has been difficult to obtain the quality and optical characteristics necessary for window glass for automobiles.

  Japanese Laid-Open Patent Publication No. 6-1633 discloses a method for adjusting the glass reduction rate by using a combination of high reduction rate frit glass, glass raw material batch of sodium sulfate and carbon. However, there is no disclosure or suggestion regarding the presence or absence of the effect of preventing NiS formation.

Japanese Patent Application Laid-Open No. 11-116270 discloses a method for obtaining the optical characteristics of an ultraviolet-absorbing colorless and transparent soda-lime silica glass by adding glass frit containing V ₂ O ₅ and Se, respectively. However, the composition of the glass frit uses a low melting point glass such as borosilicate, and the effect of preventing the formation of NiS was not obtained.

  JP-T-2005-519015 discloses melting efficiency by selectively fritting, pelletizing, or pre-reacting a specific batch component to reduce gross segregation of the batch component and further controlling the thermal reaction path. A method for improving the above is disclosed. However, there is no disclosure or suggestion about the presence or absence of the effect of preventing NiS generation.

  By the way, the carbon-based reducing agent described above has an important function for determining the redox state of glass. As an index representing the redox state of glass, it is common to use the ratio of divalent iron to the total iron oxide in the glass (FeO ratio). A reducing agent such as carbon serves to increase the FeO ratio. On the other hand, sulfate compounds and nitrate compounds have a function of lowering the FeO ratio.

  Divalent iron in glass absorbs infrared rays well. In window glass for automobiles, high heat ray absorption performance is obtained by utilizing absorption by this divalent iron. In this case, it is necessary to obtain a desired FeO ratio while maintaining the homogeneity and foam quality of the glass as a product.

  On the other hand, NiS produced in glass is deeply related to the redox state of glass. Qualitatively, it is known that NiS is difficult to produce if the glass is in an oxidized state and is easy to produce if it is in a reduced state. In terms of the above-mentioned FeO ratio, NiS is more easily generated if an attempt is made to obtain a high FeO ratio in order to obtain high heat ray absorption performance.

  Therefore, in order to obtain desired optical characteristics, a technique for suppressing the formation of NiS while requiring a particularly high FeO ratio is required.

  In view of these circumstances, an object of the present invention is to provide a method for producing a glass article that can reduce the production of NiS as much as possible in a glass article containing NiO. Furthermore, it aims at provision of the manufacturing method of the glass article which can reduce the production | generation of NiS as much as possible, without being influenced by the bubble quality and redox state of glass.

The present inventors consider that inhibiting NiO and S ²⁻ in the temperature range near 800 to 1200 ° C. in the process of melting glass is very important for reducing the number of NiS. It was.

Therefore, the idea was to surround the NiO with a glass melt not containing S ²⁻ . In order to realize this, the following method was devised.
(1) Use a glass melt containing NiO. (2) Use a batch compression-molded product containing NiO.

(1) Glass melt containing NiO The first of the specific solutions according to the present invention is a method of preparing a glass melt containing NiO in advance and using it. This glass melt raw material does not contain sulfate. The glass melt is preferably used in the form of a frit.

The composition of the glass melt preferably has the same or higher temperature of log η = 4 than that of the final glass article. When the temperature of log η = 4 is low, the glass melt containing NiO diffuses rapidly around the specific temperature range. For this reason, it is not sufficient to surround the periphery of NiO with a glass component made of an oxide not containing S ²⁻ . For example, when the final glass composition is soda lime silica glass, it is preferable to use a glass having a log η = 4 temperature of about 1000 ° C. or higher.

(SiO ₂ )
Moreover, this glass melt needs to be finally mixed with other raw materials to form a homogeneous glass composition. Therefore, if the viscosity is too high compared to the final glass composition, it may be difficult to mix with other raw materials, resulting in problems such as color spots. For this reason, this glass melt preferably contains 60 to 80% of SiO ₂ component, and more preferably 65 to 80%.

(NiO)
In the manufacturing method of the present invention, only this glass melt supplies NiO to the final glass article. The content of NiO in the final glass article is expressed by the product of the content of NiO in the glass melt and the proportion of the glass melt used. The proportion of the glass melt having a composition different from that of the final glass article is preferably smaller from the viewpoint of obtaining homogeneous glass.

  On the other hand, as the NiO content in the glass melt increases, the number of NiS produced in the final glass article tends to increase. For this reason, the NiO content in the glass melt is preferably 15% or less, and more preferably 6% or less.

(Shape, particle size)
The glass melt may be used after being formed into various shapes such as a spherical shape, a cylindrical shape, a flat plate shape, a flake shape, a cubic shape, and a thread shape. In particular, it is preferably molded into a shape having a relatively small specific surface area such as a spherical shape, a cylindrical shape, or a cubic shape. The glass melt is preferably used in as large a shape as possible within a range that does not impair the homogeneity of the final glass composition.

When the shape of the glass melt is approximately particulate, when converted into a sphere, it is preferably molded so that the average particle size is at least 1.5 mm, and the average particle size is at least 5 mm. It is more preferable. The particle size is the particle diameter.
When the shape of the glass melt is approximately flaky, it is preferable to mold the glass melt so that its thickness is at least 0.5 mm. In the case of a flaky shape, the average particle size is preferably at least 10 mm.

In this glass melt, the ratio (S / V) of the surface area S (mm ² ) to the volume V (mm ³ ) is preferably 4 mm ⁻¹ or less. For example, when the glass melt is a sphere, S / V = 4 mm ⁻¹ at a diameter of 1.5 mm, S / V = 3 (mm ⁻¹ ) at a diameter of 2 mm, and S / V = at a diameter of 6 mm. 1 mm ⁻¹ . Therefore, when the glass melt has a spherical shape, the diameter should be 1.5 mm or more in order to make S / V 4 mm ⁻¹ or less.

(2) Compression molded product containing NiO The second specific solution according to the present invention is a method of preparing a compression molded product obtained by previously compressing and molding a batch of glass melt containing NiO and using this. . This compression molded product does not contain sulfate. In addition, compression-molding the raw material of a glass batch may be called briquetting.

  The glass composition when the compression molded product is melted may be basically the same as that of the glass melt containing NiO described above.

Further, the compression molded product needs to be finally mixed with other raw materials to form a homogeneous glass composition in the same manner as the glass melt described above. For this reason, if the viscosity when the compression molded product is melted is too high compared to the final glass composition, it may be difficult to mix with other raw materials, resulting in problems such as color spots. Therefore, the compression molded product preferably contains 60 to 80% of SiO ₂ component, and more preferably 65 to 80%.

(shape)
The compression molded product may be molded into various shapes such as a spherical shape, a cylindrical shape, a flat plate shape, a flake shape, a cubic shape, and a thread shape. In particular, it is preferably molded into a shape having a relatively small specific surface area such as a spherical shape, a cylindrical shape, or a cubic shape.

In this compression molded product, the ratio (S / V) of the surface area S (mm ² ) to the volume V (mm ³ ) is preferably 1 mm ⁻¹ or less when the compression molded product is a sphere. Therefore, the diameter when the compression molded product is a sphere is preferably 6 mm or more.

  In addition, in order to make a compression molding product into a sphere, it is necessary to compress by a hydrostatic pressure, and this is not common. When producing a compression-molded product, the easiest method is to press and mold in a uniaxial direction. In that case, a cylindrical shape, a plate shape, a thin piece shape, a rectangular parallelepiped shape, etc., where the pressing surface is a parallel plane, or a flat shape where the pressing surface is a curved surface by using a device such as a tableting machine and a mold Is generally.

(composition)
It is preferable that the compression-molded product does not include a raw material that quickly decomposes such as a nitrate compound or a hydroxide, or a raw material that forms a liquid phase at a high temperature such as a sulfate compound. It is preferable to use a raw material mainly composed of an oxide and a carbonate compound for the compression molded product. For example, in soda lime silica-based glass, it is preferable to use at least one selected from a raw material group consisting of silica sand, dolomite, limestone, and soda ash.

  About the NiO content rate in a compression molding, it is the same as that of the glass melt mentioned above.

  The compression molded product may contain a coloring component other than NiO in the batch, and more preferably contains iron oxide. By including iron oxide in the compression-molded product, it is presumed that a higher NiS suppression effect can be obtained by the action of its own oxidizing power or the affinity between Fe and S. When iron oxide is contained in the compression molded product, 2% or more is preferable.

(Composition of glass article)
In the method for producing a glass article of the present invention, the composition of the glass article to be produced is preferably soda lime silica glass containing NiO as a coloring component. As a specific basic glass composition, expressed in mass%,
SiO ₂ 65~80%,
Al ₂ O ₃ 0-5%,
MgO 0-10%,
CaO 5-15%,
MgO + CaO 5-15%,
Na ₂ O 10-18%,
K ₂ O 0-5%,
Na ₂ O + K ₂ O 10-20%,
B ₂ O ₃ 0-5%
The composition containing Ni may be exemplified, and it is preferable that 0.03 to 2.0% of NiO as a coloring component is contained.

Furthermore, this glass article may contain coloring components other than NiO in order to adjust optical characteristics such as color tone, and the type thereof is not particularly limited. In addition to iron oxide, TiO ₂ , CeO ₂ , CoO, Se, or the like may be included.

As the content of the coloring component, in addition to NiO,
Exceeding T-Fe ₂ O ₃ 0 to 1.4%,
(T-Fe ₂ O ₃ is total iron oxide converted to Fe ₂ O ₃ )
Over TiO ₂ 0 to 1%,
CeO _{2 over} 0 to 2%,
Over CoO 0 to 0.03%,
Over Se 0 to 0.003%,
The case where at least 1 sort of is included can be shown.

In addition to NiO, as a coloring component,
T-Fe ₂ O ₃ 0.1-1.4%
(T-Fe ₂ O ₃ is total iron oxide converted to Fe ₂ O ₃ ),
The ratio of FeO to T-Fe ₂ O ₃ is in the range of 0.15 to 0.5;
TiO ₂ 0-1%,
CeO ₂ 0-2%,
CoO 0.01-0.03%,
Se 0-0.003%,
It is preferable that When such a colored component is used, a glass article having excellent absorption of ultraviolet rays and infrared rays and having a relatively small visible light transmittance can be obtained.

  When the glass article manufactured by the manufacturing method of the present invention contains iron oxide, the FeO ratio is preferably in the range of 20 to 30%, more preferably 21 to 27%.

  As described above, in the production method of the present invention, a glass melt or a compression molded product of the batch is mixed with a glass batch containing a sulfur compound to melt the glass. Further, the glass melt and the compression molded product of the batch may be simultaneously mixed into the glass batch to melt the glass.

  According to the glass manufacturing method of the present invention, it is possible to provide a glass article in which the generation of NiS is reduced as much as possible.

Moreover, in the NiS countermeasure in the conventional manufacturing method of glass, the ratio which adds the clarifying agent and reducing agent containing a sulfur compound was restrict | limited. However, according to the glass manufacturing method of the present invention, the ratio of the refining agent containing a sulfur compound such as mirabilite is not limited for NiS countermeasures. Furthermore, the ratio of the reducing agent added is not limited. Therefore, it becomes possible to adjust the ratio of the refining agent and reducing agent added to control the redox state of the glass independently of the NiS countermeasure.
As a result, it is possible to easily design the optical characteristics of the glass by maintaining the bubble quality of the glass while controlling the redox state while reducing the generation of NiS as much as possible.

  Hereinafter, the glass article of the present invention will be described in detail.

(1) Production of glass melt A glass melt was produced according to the following procedure. Silica sand, dolomite, limestone and soda ash were used as raw materials for the basic glass component, and nickel oxide was used as the coloring component raw material. The above raw materials were mixed at a predetermined ratio to prepare a batch.

  The prepared batch was melted by holding for 4 hours in an electric furnace set at 1450 to 1550 ° C. using a platinum crucible. Thereafter, glass melts having a desired shape and size, such as the above-described various shapes, for example, flake shape and spherical shape (marble), were obtained from the glass melt.

(2) Manufacture of compression molding The batch compression molding was produced according to the following procedures. Silica sand, dolomite, limestone and soda ash were used as raw materials, and nickel oxide and iron oxide were appropriately used as coloring component raw materials. The above-mentioned raw materials are mixed at a predetermined ratio, an appropriate amount is put into a predetermined mold, and pressed with a press machine for about 4 to 20 [× 10 ⁴ N] ( ^{4 to} 20 t) for 20 seconds to be molded into a desired shape. did. For the mold, a vinyl chloride pipe cut into a shape of φ25 mm × 3 mm thickness and φ16 mm × 5 mm thickness was sandwiched between iron dies of φ70 mm × 10 mm thickness.

(Manufacture of glass plates)
As an example of a glass article, a glass plate was produced according to the following procedure. Silica sand, dolomite, limestone, soda ash, mirabilite, and potassium carbonate were used as raw materials for basic glass components. As coloring components, nickel oxide, ferric oxide, titanium oxide, cerium oxide, cobalt oxide and metal selenium were used, and a carbon-based reducing agent was further used. The glass melt or batch compression molded product was used as the nickel oxide raw material. The above-mentioned raw materials were mixed at a predetermined ratio to prepare a glass batch.

The FeO ratio in each example was controlled by a carbon-based reducing agent (carbon powder or the like).
Moreover, the glass batch using the powdered nickel oxide raw material was also prepared, the glass plate was produced, and it was set as the comparative example.

  The prepared batch was kept in an electric furnace set at 1450 ° C. for 4 hours using a platinum crucible, and melted and clarified. Thereafter, the glass melt was poured out on the iron plate outside the furnace so as to have a thickness of about 6 mm, and cooled and solidified to obtain a glass body. The glass body was subsequently subjected to a slow cooling operation. The slow cooling operation was performed by holding the glass body in another electric furnace set at 650 ° C. for 30 minutes, and then turning off the electric furnace and cooling to room temperature.

The glass body subjected to this slow cooling operation was observed with an optical microscope (magnification: 10 to 100 times), and the number of NiS present in the glass body was measured.
The glass body after observation was cut, ground, and optically polished by applying a normal glass processing technique, and was a substantially rectangular parallelepiped having a side of about 50 mm and a thickness of 3.1 mm, and the main planes on both sides were optically polished. A glass plate was produced.

(Basic glass composition)
The basic glass composition of the produced glass is shown in Table 1. The basic glass compositions A and B have substantially the same glass composition excluding the colored components, and the content of each component differs depending on the content of the colored components. The content of each component is a quantitative analysis value using a general-purpose analysis method suitable for the component, such as an X-ray fluorescence analysis method, a chemical analysis method, or a flame analysis method. In addition, all the content rate in a table | surface is the mass% display, and the sum total is not 100% by the rounding error of an analysis result.

The basic glass compositions A and B have different coloring components, the same content of NiO and CoO, and the content of Fe ₂ O ₃ is greatly different. Furthermore, the basic glass composition A contains CeO ₂ and the basic glass composition B contains Se.

(1) Example using glass melt containing NiO Examples F1 to F23 are examples in which a glass article was manufactured using a glass melt containing nickel oxide as a nickel oxide source. The composition of the glass melt used in each example is shown in Tables 2 to 4.

  Example F1-F4 shown in Table 2 changes the content rate of NiO in a glass melt. The ratio of the glass melt was adjusted so that the NiO content in the final glass article was the basic glass composition B in Table 1. Table 2 shows the number of NiS per 100 g of glass articles and the FeO ratio.

The FeO ratio of Examples F1 to F4 was 17.5 to 18.9%. As will be described later, a comparative example R14 having substantially the same FeO ratio (18.7%) as in Examples F1 to F4 was produced using nickel oxide powder as a nickel source. The number of NiS in R14 was about 42/100 g.
Compared to this, the number of NiS in Examples F1 to F4 was about 18 to about 33 pieces / 100 g, which was smaller than that of R14.
Of these, Examples F1 to F3 are glass articles prepared using a glass melt containing 1 to 7% of NiO, and Examples using a glass melt containing 12% of NiO in the glass. Fewer than F4.

In Examples F5 to F12 shown in Table 3, the content of NiO in the glass melt was kept constant at 6%, and the content of Na ₂ O and the content of CaO were changed together with the content of SiO _2. It is a thing. The ratio of the glass melt was adjusted so that the NiO content in the final glass article was A in Table 1. Table 3 shows the number of NiS per 100 g of glass article.

The FeO ratio of Examples F5 to F12 was 20 to 23%. As will be described later, the number of NiS in Comparative Example R10 having substantially the same FeO ratio (23%) as in Examples F5 to F12 was about 19/100 g.
Compared to this, the number of NiS in Examples F5 to F12 was about 2 to about 16 pieces / 100 g, which was smaller than that of R10.

Of these, Examples F5, F7, F11, and F12 are examples in which the SiO ₂ in the glass melt is within the range of 70 to 80%, while F6 and F8 to F10 are the SiO 2 in the glass melt. ₂ is 50% or 60%. Comparing the two, Examples F5, F7, F11, and F12 were able to reduce the number of NiS in the glass article.

  Examples F13 to F16 and Examples F17 to F23 shown in Table 4 are obtained by changing the average particle size of the glass melt with the same glass composition of the glass melt. The ratio of the glass melt was adjusted so that the NiO content in the final glass article was the basic glass composition A shown in Table 1. Table 4 shows the number of NiS per 100 g of glass article and the average particle size of the glass melt.

  The FeO ratio of Examples F13 to F16 and Examples F17 to F23 was 20 to 23%. Compared with about 19 pieces / 100 g which is the number of NiS in Comparative Example R10 having the same FeO ratio as these, the number of NiS in Examples F13 to F16 and Examples F17 to F23 is about 0.4 to about 13 pieces / 100 g, and about 0.4 to about 10 pieces / 100 g, which was less than that of R10.

  The glass articles of Examples F14, F16 to F17, and F20 to F23 are glass articles having a preferable average particle diameter of 1.5 mm or more. Compared with the glass article produced using the glass melt whose average particle diameter is less than 1.5 mm, the number of NiS in the glass article could be reduced.

FIG. 1 shows the relationship between the average particle diameter of the glass melt and the number of NiS per 100 g. As is clear from FIG. 1, it can be seen that the number of NiS suddenly decreases when the average particle size is increased. The same tendency was shown when the content of SiO ₂ in the glass melt was 70% or 80%.

(2) Examples using batch compression-molded product containing NiO Examples B1 to B11 are examples in which a glass article was produced using a batch compression-molded product containing nickel oxide as a nickel oxide source. . Tables 5 and 6 show the composition of the compression molded product used in each example.

  This compression molded product is essentially a compressed and solidified batch of quartz sand, dolomite, limestone, soda ash and nickel oxide.

  Of the examples shown in Table 5, Examples B1 to B3 do not include an iron source in the compression molded product. The ratio of the compression molded product was adjusted so that the NiO content in the final glass article was the basic glass composition A shown in Table 1. Table 5 shows the number of NiS per 100 g of glass articles and the FeO ratio.

  Compared to the NiS number of about 19/100 g in Comparative Example R10 described above, the NiS numbers in Examples B1 and B2 are about 8/100 g and about 9/100 g, which are smaller than those of R10. I was able to.

  In Example B3, 5% by mass of cerium oxide was included in the compression-molded product, and the number of NiS in the glass article produced using the compression-molded product of B3 can be made smaller than B1 and B2. did it.

  Of the examples shown in Table 5, Examples B4 to B8 include iron oxide as an iron source in the compression molded product. The number of NiS of the glass articles produced using the compression molded products of B4 to B8 could be further reduced than B1 and B2. Moreover, the tendency for the number of NiS to reduce was seen, so that the iron oxide contained in a compression molding increases.

  FIG. 2 shows the relationship between the FeO ratio and the number of NiS per 100 g of glass article in an example using a compression molded product and a comparative example described later. As is clear from FIG. 2, in this example and the comparative example, there was a large difference in the rate of increase in the number of NiS with respect to the increase in the FeO ratio, that is, the slope of the approximate line. That is, in the comparative example, when the FeO ratio is increased, the number of NiS is also greatly increased, but in comparison with this, it was found that the rate of increase is small.

In the compression molded products of Examples B9 to B11 shown in Table 6, the ratio (S / V) of the surface area S (mm ² ) to the volume V (mm ³ ) is 1.2 and 0.8, respectively. It is molded into The compression molded product molded to have a diameter of φ25 mm × 2 mm was S / V = 1.2, and the thickness of φ16 mm × 4 mm was S / V = 0.8. Table 6 shows the number of NiS per 100 g of the glass article, the FeO ratio, and the S / V value.

In any of B9 to B11, the number of NiS was smaller when S / V = 0.8 than when S / V = 1.2.
In addition, B10 is a nickel oxide content in the compression-molded product that is twice that of B9, and the number of NiS decreased from B9.

(Comparative example)
The glass articles of Comparative Examples R1 to R11 are examples in which glass articles were prepared using a powdered nickel oxide raw material as a nickel oxide source. In Comparative Examples R1 to R11, the FeO ratio is changed by the carbon powder, and the others are the same. Tables 7 and 8 show the compositions of the glass melts used in the comparative examples.

Comparative Examples R1 to R11 shown in Table 7 are for the basic glass composition A, and Comparative Examples R12 to R15 shown in Table 8 are for the basic glass composition B.
The number of NiS found in the glass articles of each comparative example greatly increased in proportion to the FeO ratio of the glass articles. FIG. 3 shows the case of the basic glass composition A, and FIG. 4 shows the case of the basic glass composition B. In the case of the basic glass composition B, the rate of increase in the number of NiS due to the increase in the FeO ratio is larger than in the case of the basic glass composition A.

  From the results of the above examples, the glass melt containing nickel oxide and the compression molded product of the glass melt batch are mixed and melted in the glass batch to reduce the production of NiS in the obtained glass article. It became clear that we could do it. It was also confirmed that the formation of NiS was suppressed when a frit containing nickel oxide and a compression molded product were included at the same time.

  In the above examples and comparative examples, the composition of the glass article to be manufactured was only one, but the present invention is applicable if the target glass article is a soda lime silica glass composition containing NiO. A method for producing a possible glass article.

  The glass manufacturing method according to the present invention can reduce NiS in a glass article containing a NiO composition. The present invention can be suitably used particularly for the production of a glass plate formed into a plate shape by a float method or a roll-out method.

  Furthermore, the glass manufacturing method according to the present invention does not limit the ratio of the refining agent containing sulfur compounds such as mirabilite and the ratio of the reducing agent added for NiS countermeasures. Therefore, the ratio of the refining agent or reducing agent that controls the redox state of the glass can be adjusted independently of the NiS countermeasure. Therefore, NiS can be reduced without affecting the bubble quality and redox state of glass in a glass article containing FeO in a predetermined range and containing a NiO composition. Thus, the manufactured glass plate can be utilized suitably as a base plate for heat strengthening.

It is a graph which shows the relationship between the particle size of a glass melt, and the number of NiS per 100g of glass articles. It is a graph which shows the relationship between the FeO ratio of a glass article, and the number of NiS per 100g when a compression molding is used for a nickel source. It is a graph which shows the relationship between the FeO ratio of a glass article, and the number of NiS per 100g in the case of the basic glass composition A when powdered nickel oxide is used as a nickel source. It is a graph which shows the relationship between the FeO ratio of a glass article, and the number of NiS per 100g in the case of the basic glass composition B when powdered nickel oxide is used as a nickel source.

Claims (12)

  A method for producing a glass article, comprising mixing a glass batch containing a sulfur compound with a glass melt containing nickel oxide as a nickel oxide source or / and a compression-molded product of the glass melt batch. The glass melt is expressed in mass%,
SiO ₂ 60~80%,
Al ₂ O ₃ 0-5%,
MgO 0-10%,
CaO 0-15%,
MgO + CaO 5-15%,
Na ₂ O 10-18%,
K ₂ O 0-5%,
Na ₂ O + K ₂ O 10-20%,
NiO 1-15%
The manufacturing method of the glass article of Claim 1 adjusted so that it might become a composition containing this.   The method for producing a glass article according to claim 1 or 2, wherein the glass melt is made into particles and the average particle size is at least 1.5 mm.   The method for producing a glass article according to claim 1 or 2, wherein the glass melt is made into a flake, the thickness is at least 0.5 mm, and the average particle size is at least 10 mm.   The manufacturing method of the glass article of Claim 2 which expressed the content rate of the said NiO in the said glass melt by mass%, and was 1-7%. Wherein the content of the SiO ₂ in the glass melt, expressed in mass%, manufacturing method of a glass article according to claim 2 which is a 65% to 80%.   The method for producing a glass article according to claim 1 or 2, wherein the compression-molded product is obtained by compressing and solidifying a batch composed substantially of silica sand, dolomite, limestone, soda ash and nickel oxide.   The manufacturing method of the glass article of any one of Claims 1, 2, or 7 in which the said compression molding contains 5 to 15% of nickel oxide by mass%. The compression molded product, expressed in wt%, further, the total iron content which terms of Fe ₂ O _3, a manufacturing method of a glass article according to claim 1 or 2 containing from 0.05 to 40%.   The method for producing a glass article according to claim 9, wherein the total iron content is expressed in mass% and includes 1 to 10%. In the manufacturing method of the glass article of any one of Claims 1-10,
The basic composition of the glass article is expressed in mass%,
SiO ₂ 65~80%,
Al ₂ O ₃ 0-5%,
MgO 0-10%,
CaO 5-15%,
MgO + CaO 5-15%,
Na ₂ O 10-18%,
K ₂ O 0-5%,
Na ₂ O + K ₂ O 10-20%,
B ₂ O ₃ 0-5%
Including
A method for producing a glass article having a glass composition containing at least 0.03 to 2.0% of NiO as a coloring component. A glass article manufactured by the method for manufacturing a glass article according to claim 11,
As a coloring component,
Exceeding T-Fe ₂ O ₃ 0 to 1.4%,
(T-Fe ₂ O ₃ is total iron oxide converted to Fe ₂ O ₃ )
Over TiO ₂ 0 to 1%,
CeO _{2 over} 0 to 2%,
Over CoO 0 to 0.03%,
Over Se 0 to 0.003%,
Glass articles containing at least one of them.

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