JP2014214046A - Glass plate having light-shielding layer and method for producing glass plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass plate excellent in concealability, and having a light-shielding layer hardly discolored.SOLUTION: A glass plate comprises: a glass substrate 1; and a light-shielding layer 2 provided on a surface of the glass substrate 1 and including an inorganic pigment and glass. The light-shielding layer 2 has average film thickness of 3-8 μm. The light-shielding layer 2 has surface roughness Ra of 0.3 μm or less. The glass comprises glass powder. The glass powder has an average particle diameter of 1.0 μm or less.

Description

  The present invention relates to a glass plate having a light shielding layer and a method for producing the glass plate, which can be used for a window glass for a combustion apparatus.

  A glass substrate made of crystallized glass is used as a window glass of a heating device such as a stove or a fireplace that burns firewood, gas, coal, oil, or the like. For example, the window glass for the combustion apparatus is fixed to the metal frame of the main body of the combustion apparatus via a gasket or an adhesive, and the surface of the glass substrate is shielded from light so as to conceal the metal frame or gasket of the stove, for example. A layer is provided. For example, Patent Documents 1 and 2 disclose a method of forming a layer containing an inorganic pigment and glass powder on the surface of a transparent crystallized glass plate.

JP 2007-39294 A JP 2010-96390 A

  Since Patent Document 1 aims to form a relatively dense decorative layer on the glass surface, there is a problem that cracks are likely to occur in the decorative layer when the combustion apparatus is used for a long period of time. Moreover, since it is inferior in light-shielding property, even if the said method is employ | adopted, a gasket and an adhesive agent cannot fully be concealed.

  On the other hand, according to the method proposed in Patent Document 2, since the amount of the inorganic pigment contained in the light shielding layer is relatively large, it is porous and hardly generates cracks due to heat. However, there is a problem that the appearance is inferior due to insufficient light shielding properties.

  In addition, the light shielding layer may be discolored by soot or water vapor generated by combustion.

  An object of the present invention is to provide a glass plate having a light-shielding layer that is excellent in concealment and hardly discolors.

  The glass plate having the light shielding layer of the present invention comprises a glass substrate and a light shielding layer containing an inorganic pigment and glass, which is provided on the surface of the glass substrate, the glass is made of glass powder, and the average particle diameter of the glass powder is It is 1.0 μm or less, the average film thickness of the light shielding layer is 3 to 8 μm, and the surface roughness Ra of the light shielding layer is 0.3 μm or less.

  The content of the inorganic pigment in the light shielding layer is preferably 40 to 80% by mass, and the content of glass is preferably 20 to 60% by mass.

  In general, the light shielding layer can be obtained by firing a film containing an inorganic pigment powder and a glass powder. In this case, the average particle diameter of the inorganic pigment powder is preferably 0.8 μm or less.

  The glass plate having the light shielding layer of the present invention can be used as a window glass for a combustion apparatus.

  The manufacturing method of the glass plate of this invention is a manufacturing method of the glass plate provided with the glass substrate and the light shielding layer containing the inorganic pigment and glass provided on the surface of the said glass substrate, and an average particle diameter is 1. The method includes a step of placing a mixture of glass powder of 0 μm or less and an inorganic pigment powder on the glass substrate, and a step of baking the glass substrate on which the mixture is disposed to form a light shielding layer.

  The average thickness of the light shielding layer is preferably 3 to 8 μm, and the surface roughness Ra of the light shielding layer is preferably 0.3 μm or less.

  According to the present invention, it is possible to improve the concealment property of the light shielding layer and to prevent discoloration.

It is typical sectional drawing which shows the glass plate which has the light shielding layer of one Embodiment of this invention. It is a typical perspective view which shows an example of the window glass for combustion apparatuses. It is a typical fragmentary sectional view which shows an example of the window glass for combustion apparatuses.

  Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In the drawings for describing the following embodiments, members having substantially the same function are referred to by the same reference numerals.

  FIG. 1 is a schematic cross-sectional view showing a glass plate having a light shielding layer according to an embodiment of the present invention. As shown in FIG. 1, the light shielding layer 2 is provided on the surface of the glass substrate 1 of the glass plate 10 which has a light shielding layer. In this embodiment, the average film thickness of the light shielding layer 2 is 3 to 8 μm, preferably 4 to 5 μm. If the average film thickness of the light shielding layer 2 is too small, high concealing properties may not be obtained. Moreover, when the average film thickness of the light shielding layer 2 is too large, a crack may be easily generated. The average film thickness of the light shielding layer 2 is obtained by, for example, expanding the surface shape of the boundary between the light shielding layer 2 and the glass substrate 1 using a surface roughness measuring machine Surf Test SJ-400 (surface roughness measuring instrument) manufactured by Mitutoyo Corporation. It is possible to measure from the difference in height between the surface of the light shielding layer 2 and the surface of the glass substrate 1.

  In the present embodiment, the surface roughness Ra of the surface 2a of the light shielding layer 2 is 0.3 μm or less, preferably 0.15 μm or less. When the surface roughness Ra of the surface 2a of the light shielding layer 2 is larger than 0.3 μm, when soot, water vapor or the like adheres to minute irregularities on the surface, the soot, water vapor or the like is difficult to peel off from the glass plate 10, and these The light shielding layer 2 changes color due to accumulation over a long period of time. The lower limit value of the surface roughness Ra of the surface 2a of the light shielding layer 2 is not particularly limited, but is generally 0.05 μm or more. The surface roughness Ra can be measured in accordance with Japanese Industrial Standard (JIS) 0601-1976, and is measured by, for example, a surface roughness measuring machine Surf Test SJ-400 (surface roughness measuring instrument) manufactured by Mitutoyo Corporation. be able to. In FIG. 1, the unevenness of the surface 2 a of the light shielding layer 2 is illustrated with emphasis, and does not show actual unevenness.

The light shielding layer 2 contains an inorganic pigment and glass. This glass is made of glass powder, and the average particle diameter (D ₅₀ ) of the glass powder is preferably 1.0 μm or less, and more preferably 0.7 μm or less.

  When the particle diameter of the glass powder increases, the filling rate of the glass powder in the light shielding layer 2 decreases, and the gap volume between the glass powders increases. This gap is filled with inorganic pigment powder, but since the gap volume is large, the content of the inorganic pigment powder per unit volume of the gap is reduced, which is considered to reduce the light shielding property. . Further, when the surface roughness Ra is increased and soot, water vapor or the like adheres to minute irregularities on the surface, the soot, water vapor or the like is difficult to peel off from the glass plate 10, and the accumulation of the light shielding layer 2 due to the accumulation over a long period of time. Discolor.

  The content of the inorganic pigment in the light shielding layer 2 is preferably 40 to 80% by mass, and the glass content is preferably 20 to 60% by mass. In particular, the content of the inorganic pigment is 40 to 50% by mass, and the glass content is preferably 50 to 60% by mass. When the content of the inorganic pigment is too small, the content of the inorganic pigment is insufficient, so that the concealability may be lowered. When the amount of the inorganic pigment contained in the light shielding layer 2 is too small, the light shielding layer 2 May not be porous and may not absorb shrinkage and expansion when heating and cooling are repeated, and cracks may easily occur. When there is too much content of an inorganic pigment, adhesiveness with the glass plate 10 will be bad, and it may become easy to peel.

The average particle diameter _{(D 50)} of the inorganic pigment powder is preferably at 0.8μm or less, and more preferably in the range of 0.2 to 0.5 [mu] m. If the average particle diameter of the inorganic pigment powder is too large, it becomes difficult for the inorganic pigment powder to enter the gaps between the glass powders, and the concealability may be reduced.

The average particle diameter (D ₅₀ ) of the inorganic pigment powder and the glass powder can be measured by, for example, a laser diffraction particle size distribution measuring device.

Although inorganic pigment powder is not specifically limited, For example, oxide black pigments, such as Cr-Fe-Co-Ni type, Cu-Cr type, Cu-Cr-Fe type, Cu-Cr-Mn type; Oxide white pigments such as TiO ₂ , ZrO ₂ , and ZrSiO ₄ ; Co—Al—Zn, Co—Al—Si, Co—Al—Ti, and other oxide blue pigments; Co—Al—Cr, Co -Ni-Ti-Zn-based oxide green pigments; Ti-Fe-Zn-based, Fe-Zn-based, Fe-Ni-Cr-based, oxide-brown-based pigments such as Zn-Fe-Cr-Al-based; etc. Is mentioned. Among these, a Cr—Fe—Co—Ni black pigment is particularly preferably used because it hardly deteriorates or discolors even when heat-treated at a high temperature.

  The glass powder is not particularly limited. For example, borosilicate glass, silicate glass containing at least one of an alkali metal component and an alkaline earth metal component, phosphate containing zinc and aluminum. System glass and the like.

  A film containing an inorganic pigment and glass can be formed by preparing a paste containing inorganic pigment powder, glass powder, an organic binder, a solvent, and the like and applying this paste onto the glass substrate 1. As a coating method, various printing methods such as a screen printing method and an ink jet method can be used. The average film thickness of the light shielding layer 2 can be adjusted as appropriate by adjusting the thickness of the paste film formed by printing.

  The firing temperature when firing the film containing the inorganic pigment powder and the glass powder is, for example, preferably 700 ° C. or higher, and more preferably 800 ° C. or higher. By baking at a temperature of 700 ° C. or higher, the glass powder is softened and easily flows. For this reason, the smoothness of the surface 2a of the light shielding layer 2 can be improved, and the light shielding layer 2 having a surface roughness Ra of 0.3 μm or less can be easily obtained. However, if the firing temperature is too high, the glass powder is devitrified, and the color tone of the light shielding layer 2 may be different from the desired color tone. Further, the glass powder may be excessively softened, and as a result, the gap between the glass powders may be narrowed. Therefore, the light shielding layer 2 is unlikely to be porous and absorbs shrinkage and expansion when heating and cooling are repeated. It may not be possible and cracks are likely to occur.

  Therefore, the firing temperature is preferably 900 ° C. or lower, and more preferably 850 ° C. or lower.

As described above, the glass plate having the light shielding layer of the present embodiment can be used as a window glass for a combustion apparatus. In these applications, heating and cooling are generally repeated. For this reason, it is preferable that the glass substrate 1 is what has the outstanding heat resistance and a low thermal expansion coefficient. Specifically, the softening temperature of the glass substrate 1 is preferably 700 ° C. or higher, and more preferably 750 ° C. or higher. The average linear thermal expansion coefficient at 30 ° C. to 750 ° C. of glass substrate 1 is preferably in the range of ^{-10 × 10 -7 / ℃ ~ +} 30 × 10 -7 / ℃, -10 × 10 -7 It is more preferable to be within the range of / ° C. to + 20 × 10 ⁻⁷ / ° C. Moreover, it is preferable that the glass substrate 1 has high rigidity and scratch resistance. Therefore, the glass substrate 1 is preferably crystallized glass having a low thermal expansion coefficient. Specific examples of the crystallized glass having a low thermal expansion coefficient include, for example, Neoceram N-0 manufactured by Nippon Electric Glass Co., Ltd.

  FIG. 2 is a schematic perspective view showing an example of a window glass for a combustion apparatus in which a glass plate having a light shielding layer of the present invention can be used. As shown in FIG. 2, in the window glass 20 for a combustion apparatus, a light shielding layer 2 is formed on the peripheral edge of one surface of the glass substrate 1. A portion surrounded by the light shielding layer 2 is a window portion 1 a of the glass substrate 1. By providing the light shielding layer 2, as shown in FIG. 3, the gasket 3 can be concealed so that it cannot be seen from the outside. The gasket 3 is used to fix the combustion apparatus window glass 20 to the frame of the combustion apparatus main body. Further, when an adhesive is used to fix the combustion apparatus window glass 20, the adhesive can be concealed by the light shielding layer 2. According to the present invention, the surface roughness Ra of the surface 2a of the light shielding layer 2 is 0.3 μm or less, and the average particle diameter of the glass powder is 1.0 μm or less, thereby improving the concealability of the light shielding layer 2. Further, it is possible to more reliably conceal the gasket 3 or the adhesive provided inside the light shielding layer 2.

  In addition, the glass plate of this invention can be manufactured as follows.

  First, the inorganic pigment powder and the glass powder are mixed so as to be in the above range, and are formed into a paste or a sheet using a thermoplastic resin, a solvent or the like. Thereafter, it can be obtained by placing it on the glass substrate 1 and baking at the above temperature.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to the following examples.

Example 1
After pulverizing the B ₂ O ₃ —SiO ₂ glass material using a ball mill and a jet mill, air classification was performed to obtain a glass powder having an average particle diameter (D ₅₀ ) of 0.7 μm.

Next, this glass powder and Cr—Fe—Co—Ni based inorganic pigment powder are mixed at a mass ratio of 50:50, and this mixture is mixed with ethyl cellulose as a resin binder and terpineol and butyl carbitol as a solvent. A paste was prepared by kneading with acetate. The average particle size (D ₅₀ ) of the Cr—Fe—Co—Ni inorganic pigment powder was 0.4 μm. Next, the paste is printed on a glass plate (transparent low expansion crystallized glass plate (N-0) manufactured by Nippon Electric Glass Co., Ltd.) using a screen printing method, and then fired at 830 ° C. to form a light shielding layer. did. The average film thickness of the light shielding layer was 4.0 μm, and the surface roughness Ra was 0.09 μm.

(Example 2)
A light shielding layer was formed in the same manner as in Example 1 except that glass powder and Cr—Fe—Co—Ni based inorganic pigment powder were kneaded so as to have a mass ratio of 30:70. The thickness of the light shielding layer was 4.5 μm, and the surface roughness Ra was 0.15 μm.

Example 3
A light shielding layer was formed in the same manner as in Example 1 except that glass powder having an average particle diameter (D ₅₀ ) of 1.0 μm was used. The thickness of the light shielding layer was 4.5 μm, and the surface roughness Ra was 0.25 μm.

(Comparative Example 1)
A light shielding layer was formed in the same manner as in Example 1 except that glass powder having an average particle diameter (D ₅₀ ) of 1.4 μm was used. The thickness of the light shielding layer was 5.0 μm, and the surface roughness Ra was 0.37 μm.

(Comparative Example 2)
A light shielding layer was formed in the same manner as in Example 1 except that glass powder having an average particle diameter (D ₅₀ ) of 3.8 μm was used. The thickness of the light shielding layer was 5.0 μm, and the surface roughness Ra was 0.58 μm.

(Comparative Example 3)
A light shielding layer was formed in the same manner as in Comparative Example 2 except that glass powder and Cr—Fe—Co—Ni inorganic pigment powder were kneaded so as to have a mass ratio of 30:70. The thickness of the light shielding layer was 5.0 μm, and the surface roughness Ra was 0.66 μm.

(Comparative Example 4)
When the light shielding layer was formed in the same manner as in Comparative Example 2 except that the thickness of the light shielding layer was 8.5 μm, cracks occurred on the entire surface of the light shielding layer.

  The concealability and discoloration of the samples prepared in each of Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated. Comparative Example 4 was not evaluated thereafter.

  The evaluation of concealment is the visibility of light when the distance from the light source is changed to 10 cm, 30 cm, and 50 cm using a C-DSLS lamp house 6V20W halogen lamp (Nikon Corporation) at 3V setting as the light source. Visually confirmed, ◎: transmission of light cannot be confirmed, ○: transmission of light can be confirmed slightly, but there is no practical problem, △: shape of light source cannot be confirmed, but transmission of light can be confirmed, ×: light source The evaluation was made in four stages: light clearly transmitted so that the shape could be confirmed.

  Evaluation of the discoloration was carried out by applying water containing 5% by mass of soot to the surface of the light shielding layer with a brush, standing the glass plate vertically and leaving it at 50 ° C. for one month, and then on the side opposite to the light shielding layer (glass Visual observation was performed from the surface side), and evaluation was made in two stages: ◯: no discoloration was observed, ×: discoloration was observed.

  Table 1 shows the results of the examples and Table 2 shows the results of the comparative examples.

  In Examples 1 to 3, the evaluation of the shielding property was such that light transmission could not be confirmed at any distance from the light source, or light transmission to the extent that there was no practical problem was observed. It was excellent. Further, no discoloration was observed in the discoloration evaluation. On the other hand, in Comparative Examples 1-3, it was inferior to shielding, and discoloration was seen also about discoloration evaluation.

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 1a ... Window part 2 of glass substrate ... Light shielding layer 2a ... Surface 3 of light shielding layer ... Gasket 10 ... Glass plate 20 which has a light shielding layer ... Window glass for combustion apparatus

Claims (5)

A glass substrate and a light-shielding layer comprising an inorganic pigment and glass provided on the surface of the glass substrate;
The glass is made of glass powder, the average particle diameter of the glass powder is 1.0 μm or less,
The glass plate which has a light shielding layer whose average film thickness of the said light shielding layer is 3-8 micrometers, and whose surface roughness Ra of the said light shielding layer is 0.3 micrometer or less.   2. The glass plate having a light shielding layer according to claim 1, wherein the content of the inorganic pigment in the light shielding layer is 40 to 80 mass% and the content of the glass is 20 to 60 mass%.   A glass plate having a light shielding layer according to claim 1, which is a window glass for a combustion apparatus. A method for producing a glass plate comprising a glass substrate and a light shielding layer containing an inorganic pigment and glass provided on the surface of the glass substrate,
Placing a mixture of glass powder having an average particle size of 1.0 μm or less and inorganic pigment powder on the glass substrate;
And baking the glass substrate on which the mixture is disposed to form a light shielding layer.   The method for producing a glass plate according to claim 4, wherein an average film thickness of the light shielding layer is 3 to 8 μm, and a surface roughness Ra of the light shielding layer is 0.3 μm or less.

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