JP2001031444A - Fabrication of colored glass for illumination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fabrication method for glass bulbs colored in yellow to yellowish red to red in which a silver oxide-containing glass tube is used to suppress the clouding that occurs during the glass bulb fabrication without problem of heat resistance and can be used as general lighting lamps and covers without including harmful substance. SOLUTION: A SiO2-Al2O3-RO-R'2O (R is a divalent metal; R' is a monovalent metal) glass tube including Ag2O and snO2 is heated with the flame of a mixed gas for combustion containing 1.0 volume of the combustion gas and >3.5 volumes of oxygen to a glass bulb, the resultant molded glass bulb is quickly cooled, then the resultant cooled bulb is heat-treated to give the objective colored glass bulb. In molded and cooled glass bulbs, only clouding or coloring parts are heated over 1,000 deg.C to suppress the clouding or the coloring and the glass bulbs of which the clouding or coloring are suppressed may be blow- molded again, and resultant remolded glass bulbs are quickly cooled and then heat-treated to give the objective colored glass bulbs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing glass spheres for use in yellow, yellow-red, or red illumination lamps or covers.

[0002]

2. Description of the Related Art A yellow-yellow-red lamp for general decoration is used.
CdS, CdSe, CrO _ThreePigment or
Some are coated with paint containing mechanical pigments. Also yellow
And yellow-red (orange) car turn signal lamps and
As a cover for fog lamps, use organic paints and colorants.
Containing low melting point lead glass etc. painted on the glass surface,
Glass containing CdS as colorant and CdSe if necessary
Dough glass is used.

[0003] Lamps coated with an organic paint have low adhesion strength and are easily peeled off, and have a problem in heat resistance because the lamp itself rises to a temperature of 200 ° C or more when lit.
Color loss and cracks occur. Further, low-melting-point lead glass and cloth glass containing a paint or a coloring agent containing a pigment such as CdS, CdSe, or CrO ₃ contain harmful substances such as lead, cadmium, selenium, and chromium, and are not environmentally preferable.

[0004] When a glass tube containing silver oxide is heat-formed and then reheated to a temperature region much lower than the heat-forming temperature and heat-treated, the glass grows in a colloidal form with metallic silver, whereby the glass is formed. Coloring from yellow to yellow-red to red is already known.

[0005]

Such a silver oxide-containing glass tube is heated by a burner flame to form glass spheres, and then the formed glass spheres are blow-molded and heat-treated to obtain yellow to yellow-red. It is possible to obtain a red turn signal lamp for automobiles or the like. However, in the prior art, there is a problem that a colored glass ball is locally colored, or fogging or color unevenness occurs in the glass. For this reason, in the subsequent heat treatment step, the entire molded glass sphere is not uniformly colored, and color unevenness appears partially, so that a stable colored glass sphere cannot be obtained and has not been put to practical use.

[0006] Further, the shape of the glass sphere for lighting is various depending on the application, such as a lamp with a base, a wedge base lamp, a fog lamp cover for automobiles, and the like, which processes a part of a glass tube and an outer diameter of a glass tube used. In the case of a glass having a large thickness or a thick wall, color unevenness and fogging appear remarkably on the glass.

The reaction in which silver oxide becomes fine particles of metallic silver is an oxidation-reduction reaction as described below. When silver in the glass is in the ion state of silver oxide, the glass is colorless. When ions such as tin coexist in the glass, silver ions are reduced to metallic silver fine particles by reheating to a temperature range much lower than the melting temperature, and the glass turns yellow to yellow red to red. It is recognized as being colored or cloudy.

[0008]

(Equation 1)

As described above, considering that the cause of clouding or color unevenness of the silver oxide-containing glass is a redox reaction of silver, it is possible to increase the amount of oxygen contained in the flame used for heat-forming a glass tube. In addition, the reduction of silver oxide to metallic silver can be suppressed, the formation of metallic silver due to the heating of the glass tube can be suppressed, and the coloring of glass due to the formation of metallic silver can be controlled, and as a result, color unevenness and cloudiness The inventor has found that it is possible to suppress

A detailed examination of the cause of the above-mentioned color unevenness and fogging shows that the temperature range in which silver oxide is colloidally reduced to metallic silver (hereinafter referred to as "coloring temperature range").
Is about 400-1000 ° C., above which the metallic silver ionizes. The temperature at which the glass tube is processed into glass spheres varies from about 800 to 1300 ° C. depending on the part. The glass sphere is formed by heating the glass tube with a burner, but the glass sphere reaches the above-mentioned color temperature range during heating and cooling, and metallic silver grows, which causes color unevenness in the product. Or cloudiness. In addition, although the temperature of the heated portion is higher than the color development temperature range, the temperature of the peripheral portion of the heated portion also rises to some extent, and the temperature reaches the color development temperature range. Therefore, when processing a glass tube into a glass bulb, it is preferable to avoid the above color development temperature range as much as possible.

[0011]

SUMMARY OF THE INVENTION According to the present invention, there is provided a general lighting lamp which suppresses fogging generated during processing of a glass ball using a glass tube containing silver oxide and has no problem in heat resistance and contains no harmful substances. An object of the present invention is to provide a method for processing yellow to yellow-red to red glass spheres used for a cover.

According to the invention of claim 1, Ag is used as a coloring agent.
_TwoO and SnO_TwoSiO containing_Two−Al_TwoO _Three−RO−R ′_TwoO system (expression
Where R is a divalent metal and R 'is a monovalent metal) glass tube,
Oxygen was set to 3.5 or more by volume ratio with respect to combustion gas 1.0
Heated by the flame of the combustion gas mixture,
The molded glass spheres are quenched,
Heat treatment of the shaped cooling glass spheres
Obtaining a method of processing colored glass spheres
You. That is, according to the first aspect of the present invention, the glass tube is
"Glass ball forming process" for forming into lath spheres and molded glass
"Quenching process" that rapidly cools the ball and obtained by the quenching process
Heating molded quenched glass spheres to obtain desired color tone and chromaticity
"Heat treatment step" for obtaining colored glass spheres.

According to the first aspect of the present invention, in the glass ball forming step, oxygen is added in a volume ratio of 3.
Since the glass tube is heated by the flame of the combustion gas mixture set to 5 or more, the reduction of silver oxide to metallic silver is suppressed, and the formation of metallic silver due to the heating of the glass tube can be suppressed. Can control the coloring of the glass, and thus can suppress color unevenness and fogging.

According to the invention of claim 2, Ag is used as a coloring agent.
_TwoO and SnO_TwoSiO containing_Two−Al_TwoO _Three−RO−R ′_TwoO system (expression
Where R is a divalent metal and R 'is a monovalent metal) glass tube,
Oxygen was set to 3.5 or more by volume ratio with respect to combustion gas 1.0
Heated by the flame of the combustion gas mixture,
The molded glass spheres are quenched,
Clouded or colored part of the
Heated to 1000 ° C or higher to remove cloudiness or color
Blow molded glass spheres with decolorized
The shaped and obtained reshaped glass spheres are quenched and the
Heat treatment of shaped glass spheres to obtain colored glass spheres
And a method for processing colored glass spheres. Claim
According to the second aspect of the present invention, the quenching step and the additional process of the first aspect of the present invention are provided.
A "decolorization process" is added between the heat treatment process,
In the decoloring step, the molding rapidity obtained by the rapid cooling step is obtained.
By heating the cold glass sphere, the glass sphere becomes cloudy
Decolorize and then reshape to obtain reshape glass spheres.
Quench the reshaped glass sphere and add
Glass with desired color tone and chromaticity after heat treatment
Get the ball.

According to the second aspect of the present invention, since only the clouded or colored portion of the molded cooling glass sphere is heated to 1000 ° C. or more, it is possible to ionize the metallic silver which causes clouding or coloration. , Haze or color can be suppressed and decolored. Since the glass bulb is rapidly cooled after the deformation due to the heating, the time for the glass bulb to be in the color development temperature range is short, and clouding or coloring can be effectively eliminated.

According to the invention of claim 3, Ag is used as a coloring agent.
_TwoO and SnO_TwoSiO containing_Two−Al_TwoO _Three−RO−R ′_TwoO system (expression
Where R is a divalent metal and R 'is a monovalent metal) glass tube,
Blow molding into glass spheres and quenching the resulting molded glass spheres
Of the obtained molded cooling glass spheres,
Heated to 1000 ° C or higher to eliminate cloudiness or color
Blow molding of colored, cloudy or color-suppressed glass spheres
And re-molded, quenched the resulting re-formed glass spheres,
Heat treatment of the reshaped cooling glass spheres
Obtaining a method of processing colored glass spheres
You. According to the invention of claim 3, in the glass ball forming step,
The ratio of oxygen to combustion gas 1.0 by volume was 3.5 or more.
Without the use of a flame of the combustion gas mixture
Efficiently suppresses and decolors fogging or coloring by the decoloring process
Can be

If the molded glass sphere is rapidly cooled to 400 ° C. or less, and the reshaped glass sphere is rapidly cooled to 400 ° C. or less, the time required for the glass sphere to be in the color development temperature range (400 to 1000 ° C.) is short, and clouding or coloring occurs. Can be effectively suppressed (claim 4,
5).

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Glass used in the present invention As the glass used in the present invention, any known glass containing silver oxide and tin dioxide or tin oxide can be used. Alkaline alkaline earth silicate glass containing silver and tin dioxide (SiO ₂ -Al ₂ O
₃ -RO-R _'2 O system) can be used. In the above formula, R
Means a divalent metal, and RO is BaO, SrO, Ca
O, MgO and the like can be mentioned. R ′ means a monovalent metal, and examples of R ′ ₂ O include Na ₂ O, K ₂ O, and Li ₂ O.

Glass Ball Forming Step First, the above glass tube is heated and melted to a processing temperature using a flame. The heating temperature varies depending on the composition of the glass, but is usually about 800 to 1300 ° C or more. And
Blow molding is performed by sending compressed air into a glass tube. A known method can be used for blow molding. As described above, a glass tube is heated by a flame. In the prior art, air is mixed with a combustion gas supplied from a combustion gas tank (for example, propane gas), and the combustion gas mixture is converted into a flame. Was to supply. Considering that the atmosphere contains about 20% oxygen by volume, in prior art combustion mixtures,
The combustion gas (for example, propane gas) 1.0 was mixed with the oxygen 3.0 by volume ratio. In the present invention, oxygen in the mixed gas for combustion is used as the combustion gas 1.
It was decided to be 3.5 or more for 0. In the present invention, the combustion gas, air and oxygen gas may be mixed in a mixer and supplied as a mixed gas for combustion to a flame, or the combustion gas and oxygen gas may be mixed in a mixer and mixed for combustion. This may be supplied to the flame as a gas.
Assuming that oxygen and oxygen gas contained in air at about 20% are collectively referred to as "total oxygen amount", in the present invention, the total oxygen amount may be at least 3.5 with respect to 1.0 of the combustion gas. . The greater the total oxygen content, the greater the effect of suppressing fogging.
In the present invention, since the total oxygen content of the combustion gas mixture supplied to the flame is larger than that of the related art, it is possible to suppress metallic silver that can be generated in the glass by heating, and
It is considered that coloration due to metallic silver can be suppressed.

[0020] In the quenching step the quenching step, a glass tube that is formed into a glass bulb having a desired shape is heated to a processing temperature, followed by cooling to 400 ° C. or less. Since the temperature range in which silver changes to a colloidal state and the color is in the range of about 400 to 1000 ° C., it is preferable to lower the temperature to 400 ° C. or lower as soon as possible. Known quenching methods such as cooling air blow and air cooling (natural cooling) can be used.

[0021] In the invention according to the heat treatment step according to claim 1, substantially colorless and transparent glass bulb molded as described above to heat treatment using a batch or continuous furnace, yellow ~ yellow red to red And stable colored glass spheres can be obtained. In the invention according to claim 2, after the color erasing step described later, the heat treatment step is performed. In the heat treatment step, a known method can be used, for example, a method of heating molded glass balls using a belt-type continuous electric furnace or a batch-type electric furnace. As described above, the color development temperature range in which silver oxide is reduced to metallic silver to form a color is about 400 to 1000 ° C, and the heating temperature is preferably 400 to 600 ° C. The higher the processing temperature, the shorter the color development time, but if the heat treatment is performed over 600 ° C for a long time,
This is because the glass sphere may be deformed. It is better to treat as high temperature as possible as long as the glass ball does not deform,
The processing time is short and economical and preferable. The heating time varies depending on the desired color and also varies depending on the glass composition, glass thickness, etc., but the heat treatment temperature is 400 to 600 ° C.
In this case, color development is possible in about 0.5 to 15 hours. If the colored glass of the present invention is used for a cover for a turn signal lamp or a fog lamp with respect to a desired color, the chromaticity defined by the American Automobile Manufacturers Association Standard (SAE) or the Japanese Industrial Standard (JIS) is used as a reference.

The decoloring step According to the first aspect of the invention, it is possible to effectively suppress the fogging of the molded glass sphere. However,
In the case where the glass is thick, for example, fogging cannot be sufficiently suppressed depending on the invention according to the first aspect.
In some cases, a higher quality product is required. In such a case, fogging can be effectively suppressed by applying the decoloring step according to the second aspect of the present invention.
As described above, the invention according to claim 2 is one in which a “decoloring step” is added between the quenching step and the heat treatment step. The decoloring step includes a step of heating the cloudy part, a reshaping step, and a quenching step.

First, if fogging occurs in the molded glass ball, only the fogged portion is heated to 1000 ° C. or higher by a burner flame. At this time, the mixed gas for combustion supplied to the flame preferably has a total oxygen content of 3.5 or more. Heating time is 5-15
Seconds. The fogging state is visible and basically requires time to reduce fogging to a state that takes into account the quality level of the product. As mentioned above, the silver contained in the glass is about
Ions (silver oxide) at 400 to 1000 ° C (coloring temperature range)
The metal silver is considered to be colored or cloudy, and when it exceeds about 1000 ° C., metallic silver is ionized and becomes colorless.
Utilizing such a property of silver, the coloring of the glass can be reduced or eliminated by heating the glass to a temperature exceeding about 1000 ° C. and ionizing the metallic silver in the glass. By rapidly cooling the glass heated above 1000 ° C to 400 ° C or less, the state in which the glass is in the color temperature range is as short as possible, thereby minimizing the formation of metallic silver and reducing the coloring of the glass. Can be minimized.

By the above-mentioned heating, the glass sphere is slightly deformed in the heated portion. Therefore, blow molding is performed again to correct this deformation. The blow pressure at this time is 0.5
Is a ~2.0kg / cm ^2. This blow molding is preferably performed subsequent to the heating from the viewpoint of shortening the time in terms of economy. This blow molding only corrects the deformation of the glass sphere once formed, requires only a short processing time, has small growth of metallic silver particles around the heating portion, and does not show significant coloring. The quenching of the reshaped glass spheres can be performed by a known method such as cooling air blow or air cooling (natural cooling) in the same manner as the above-mentioned quenched glass sphere quenching step.
Cool to below ° C. In this way, by applying the reshaped glass spheres with the coloring suppressed to a minimum to the above-mentioned heat treatment step, colored glass spheres with suppressed color unevenness or fogging can be obtained.

In the second aspect of the present invention,
It consists of a "glass ball forming process", a "quenching process", a "decoloring process" and a "heat treatment process". The flame in the "glass ball forming process" is supplied with oxygen gas in addition to combustion gas and air. However, even when oxygen gas is not supplied to the flame in the "glass ball forming step", by applying to the "decoloring step" and the "heat treatment step",
It is possible to effectively suppress fogging or color unevenness (claim 3).

[0026]

The present invention will be described below with reference to examples and comparative examples.

[Comparative Examples 1 and 2] First, the color unevenness of the glass sphere when the glass sphere was molded using the conventional method was examined. The glass tube used was an alkali-alkaline earth silicate glass PS94A (Ag ₂ O and Sn
O ₂ -containing SiO ₂ —Al ₂ O ₃ —RO—R ₂ O-based glass). This glass tube is heated to 1000-1300 ° C for 15 seconds and blow pressure 1.0k
g / cm ² , S-25 glass sphere (outer diameter 25.0mm, wall thickness 0.40mm)
Was molded. The combustion gas mixture supplied to the flame during this heating is 14.5 propane gas to 14.5 air (volume ratio).
And the total amount of oxygen in the feed gas was C ₃ H ₈ : oxygen = 1.0: 3.0. The obtained glass ball was rapidly cooled to 400 ° C. or lower in 8.5 seconds by a cooling air blow. The glass sphere obtained at this time has color unevenness,
Localized color. The chromaticity of the colorless part and the chromaticity of the colored part can be measured using a color luminance meter TOPCON BM-5 manufactured by Tokyo Optical Machine Co., Ltd.
It measured using. The results are shown in Table 1 (before heat treatment).
Further, this quenched glass ball was subjected to a heat treatment. When the quenched glass balls were heated in an electric furnace at 550 ° C. for 3 hours (Comparative Example 1) and 4 hours (Comparative Example 2), the color of the entire glass ball was exhibited, but the color irregularity was observed. Table 1 shows the chromaticity after the heat treatment.

[0027]

【table 1】

From the above results, when glass spheres were formed by the conventional method in which the total oxygen content of the mixed gas for combustion was 3.0, coloring occurred locally during the formation, and such glass spheres were subjected to heat treatment. In this case, a large chromaticity difference was observed between the colorless portion and the colored portion at the time of molding, which proved to be unsuitable as a product.

[0029]

Embodiments 1 to 3 and Comparative Example 3 Next, an embodiment of the invention according to claim 1 and a conventional technique (comparative example) were performed. Heat the glass tube of the alkali-alkali earth silicate glass PS94A manufactured by Nippon Electric Glass Co., Ltd. to 800-1300 ° C for 15 seconds,
At a blow pressure of 1.0 kg / cm ² , S-25 glass spheres (outer diameter 25.0 mm,
(Wall thickness 0.40 mm). Table 2 shows the composition of the mixed gas for combustion supplied to the flame during this heating. The formed glass ball was rapidly cooled to 400 ° C. or less in 8.5 seconds by a cooling air blow. At this time, the degree of fogging of the obtained glass sphere was visually confirmed. Table 2 shows the results.

[0030]

[Table 2]

In the molding of S-25 glass spheres, the entire glass processing portion is heated and blow-molded using a mold. In Comparative Example 3 (total oxygen amount 3.0), which is a conventional method, the molded glass spheres are used. Was cloudy on the side of the head. On the other hand, Example 2 in which the total oxygen content was set to 4.5 and 7.5 with respect to propane gas 1.0.
In cases 3 and 3, the occurrence of fogging was suppressed. propane gas
In the case of Example 1 in which the total oxygen content was set to 3.5 with respect to 1.0, a useable product was obtained although slight clouding was observed. When these molded cooling glass spheres were heated to 550 ° C. for 3 hours in an electric furnace, the colored glass spheres of Examples 2 and 3 did not show color unevenness or fogging. Although it was cloudy, it was usable as a product. On the other hand, the colored glass spheres of Comparative Example 3 were clouded.

The S-25 glass sphere has a small thickness. Therefore, according to the first aspect of the present invention, the fogging or coloration of the glass can be effectively suppressed as described above. However, when the thickness of the glass is increased, the fogging or coloration of the glass may not be effectively suppressed only by the invention according to claim 1. Further, although Example 1 is used as a product, it is also conceivable to further remove the fogging and obtain a high quality product. In these cases, the invention according to claim 2 can effectively suppress the fogging or coloring of the glass. Next, examples and comparative examples of the invention according to claim 2 will be described.

[0033]

Embodiments 4 and 5 Embodiments 4 and 5 are the second aspect of the present invention. The primary molding step and quenching in Example 4 were performed under the same conditions as in Example 1. As described in Example 1, when the total oxygen content was 3.5, the evaluation of fogging was Δ, indicating that some fogging was observed but usable. In order to eliminate the slight clouding and obtain a better product, a decoloring step according to claim 2 is added. Of the glass spheres formed in the first forming step under the same conditions as in Example 3, only the fogged portion was heated to about 1200 ° C. with a burner flame, and the fog disappeared in 5 seconds. The composition of the combustion gas mixture supplied to the flame at this time was as shown in Table 3. The heated part deformed somewhat. After the cloudiness disappeared, re-molded by blow molding at 1.0 kg / cm ² and then cooled by air blow and air cooling.
Next, the obtained glass spheres were placed in a batch-type electric furnace, and were cooled in Table 3.
At the heating temperature shown in Table 3 and for the heating time shown in Table 3. The glass spheres were uniformly colored throughout and had almost no fogging, and were used as products. The chromaticity of the obtained glass sphere was measured by the color luminance meter, and the degree of fogging was visually recognized. Table 3 shows the results.

[0034]

[Embodiment 6] This embodiment is not included in the invention of claim 1, but is included in the invention of claim 2. In the present example, the same conditions as in Comparative Example 3 were performed until the primary molding step was performed and quenched. That is, heat the PS94A glass tube to 800-1300 ° C for 15 seconds, and blow pressure 1.0kg
In / cm ^2, glass spheres S-25 (outer diameter 25.0 mm, wall thickness 0.40 mm)
The flame used for heating was propane and air only, and the total oxygen content was 3.0. The obtained glass spheres were clouded. When only the fogged portion of the glass sphere was heated to about 1200 ° C. with a burner flame, the fog was reduced to an extent that it could be used as a product in 5 seconds. At this time, the composition of the combustion gas mixture supplied to the flame is:
The results are shown in Table 3. The heated part deformed somewhat. After the fogging was reduced, it was re-formed by blow molding at 1.0 kg / cm ² , and then rapidly cooled to 400 ° C or less by cooling air blowing and air cooling. Next, the obtained glass balls were placed in a batch type electric furnace.
At the heating temperature shown in Table 3 and for the heating time shown in Table 3. The glass spheres were uniformly colored throughout and had almost no fogging, and were used as products. The chromaticity of the obtained glass sphere was measured by the color luminance meter, and the degree of fogging was visually recognized. Table 3 shows the results.

[0035]

[Examples 7 to 15] A glass tube of PS94A was heated at 800 to 1300 ° C for 1 hour.
Heat for 8 seconds, and at a blow pressure of 1.5 kg / cm ² , T-20 (outer diameter 20 mm,
0.80 mm thick). The mixture gas for combustion supplied to the flame at the time of this heating was as shown in Table 3. The obtained glass sphere is blown by cooling air blow in 10.0 seconds,
Rapidly cooled to 400 ° C or less. The glass sphere obtained at this time had fogging on the side of the head. Next, only the portion where fogging occurred was heated to about 1200 ° C. with a burner flame, and the fogging disappeared in 6 seconds. The composition of the combustion gas mixture supplied to the flame at this time was as shown in Table 3. The heated part deformed somewhat. After fogging disappears, after re-molded by blow molding at 1.5 kg / cm ^2, the cooling air blow and air
Next, the obtained glass spheres were placed in a batch-type electric furnace, and were cooled in Table 3.
At the heating temperature shown in Table 3 and for the heating time shown in Table 3. The glass spheres were uniformly colored throughout. Table 3 shows the results.

[0036]

[Examples 16 to 17] A glass tube of PS94A was heated at 800 to 1300 ° C for 3 hours.
After heating for 0 seconds, a cover for fog lamps (outer diameter 24 mm, wall thickness 1.70 mm) was formed at a blow pressure of 2.0 kg / cm ² . The mixture gas for combustion supplied to the flame at the time of this heating was as shown in Table 3. The obtained glass ball was rapidly cooled to 400 ° C. or less in 20.0 seconds by a cooling air blow. The glass sphere obtained at this time had fogging on the side of the head. Next, only the portion where fogging occurred was heated to about 1200 ° C. with a burner flame, and the fog disappeared in 15 seconds. The composition of the combustion gas mixture supplied to the flame at this time was as shown in Table 3. The heated part deformed somewhat. After the cloudiness has disappeared,
After re-molding by blow molding at 2.0 kg / cm ^2, it was quenched to 400 ° C or less by cooling air blow and air cooling.Next, the obtained glass balls were put into a belt type continuous electric furnace,
Heating was performed at the heating temperature shown in Table 3 and the heating time shown in Table 3, and color was formed. The glass spheres were uniformly colored throughout. Table 3 shows the results.

[0037]

[Table 3]

In Table 3, the illuminance ratio is a ratio when the illuminance of a colorless bulb is 1.00. Further, the color tone was expressed by perceived color, and the chromaticity was expressed by x, y coordinates of an XYZ color system measured by a chromaticity meter. As described above, glass spheres which were colored yellow to yellow-red to red, had no haze, or had no haze enough to be used as a product were obtained. As described above, it was possible to eliminate the fogging generated during blow molding from a glass tube by the decoloring step of heating and molding the molded product again. In the decoloring step, the glass spheres will be in the silver color development temperature range by heating, but the colored glass spheres that are the product are glass that has no haze or has only enough haze as a product. A ball was obtained. By performing the quenching, the time from the start of the decoloring step to the obtaining of the colored glass spheres is about 1 / compared to the time required to perform blow molding and heat treatment from the glass tube to obtain the colored glass spheres.
It is considered to be because the growth of the metallic silver particles did not occur.

[0039]

According to the first aspect of the present invention, since the total oxygen content in the combustion gas mixture in the glass ball forming step is set to 3.5 or more, the growth of metallic silver causing glass coloring is suppressed, Accordingly, colored glass spheres substantially free of haze or color unevenness can be obtained. According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, only the cloudy or colored portion of the blow-molded molded glass sphere is 1000 ° C.
Because of the above heating, the metallic silver generated in the molded glass spheres is oxidized to silver ions, so that the fogging or coloring disappears or decreases, so that the colored glass spheres substantially free of haze or color unevenness can get. According to the third aspect of the present invention, only the cloudy or colored portion of the blow-molded molded glass sphere is heated to 1000 ° C. or higher, so that the metallic silver generated in the molded glass sphere is oxidized to silver ions. As a result, the fogging or coloration disappears or decreases, so that colored glass spheres substantially free of fogging or color unevenness are obtained. According to the invention as set forth in claims 4 and 5, since the molded glass spheres or the reshaped glass spheres are rapidly cooled to 400 ° C. or less,
The glass bulb heated to a temperature higher than the coloration temperature range will be rapidly cooled to a temperature lower than the coloration temperature range, so that the growth of metallic silver will be suppressed, and clouding or color unevenness has been suppressed. A colored glass sphere is obtained.

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Claims (7)

[Claims] 1. A Ag ₂ O and SnO ₂ is contained as a coloring agent
SiO ₂ -Al ₂ O ₃ -RO-R ' ₂ O system (where R is a divalent metal and R' is a monovalent metal) glass tube, oxygen is added to combustion gas 1.0 by volume ratio The mixture is heated by a flame of a combustion gas mixture of 3.5 or more, blow-molded into glass spheres, the obtained molded glass spheres are quenched, and the obtained molded cooled glass spheres are subjected to a heat treatment to form colored glass spheres. A method for processing colored glass spheres. Wherein Ag ₂ O and SnO ₂ is contained as a coloring agent
SiO ₂ -Al ₂ O ₃ -RO-R ' ₂ O system (where R is a divalent metal and R' is a monovalent metal) glass tube, oxygen is added to combustion gas 1.0 by volume ratio Heated by a flame of a mixed gas for combustion set to 3.5 or more, blow molded into glass spheres, quenched the obtained molded glass spheres, and obtained only the cloudy or colored portion of the obtained molded cooled glass spheres Is heated to 1000 ° C. or higher to eliminate the clouding or coloration, blow-mold and reshape the clouded or colorless glass spheres, and rapidly cool the obtained reshaped glass spheres. A method for processing colored glass spheres, comprising heating the reshaped cooled glass spheres to obtain colored glass spheres. Wherein Ag ₂ O and SnO ₂ as a coloring agent is contained
A glass tube of SiO ₂ —Al ₂ O ₃ —RO—R ′ ₂ O (where R is a divalent metal and R ′ is a monovalent metal) is blow-molded into glass spheres, and the resulting molding is obtained. The glass ball was quenched, and only the clouded or colored portion of the obtained molded cooled glass ball was heated to 1000 ° C. or higher to eliminate the clouded or colored portion, and the clouded or colored portion was erased. The glass spheres are blow-molded and reshaped, the obtained reshaped glass spheres are quenched, and the obtained reshaped cooled glass spheres are heat-treated to obtain colored glass spheres. Processing method. 4. The method for processing colored glass spheres according to claim 1, wherein said molded glass spheres are rapidly cooled to 400 ° C. or lower. 5. The method for processing colored glass spheres according to claim 2, wherein the reshaped glass spheres are rapidly cooled to 400 ° C. or lower. 6. The heating of only the clouded or colored portion of the molded cooling glass spheres is performed by a flame of a combustion mixed gas in which the volume ratio of oxygen to the combustion gas 1.0 is 3.5 or more. 4. The method for processing a colored glass sphere according to 2 or 3. 7. The combustion gas is propane gas.
The method for processing a colored glass sphere according to claim 1, 2 or 3.