JPWO2006068060A1 - Method for manufacturing glass article - Google Patents

Abstract

This invention is a manufacturing method of the glass article which melts the batch for melting containing the clarifier adhesion | attachment cullet which made the clarifier adhere to the surface. By bringing the aqueous solution containing the fining agent into contact with the cullet, the fining agent-attached cullet can be produced.

Description

  The present invention relates to a method for manufacturing a glass article, and more particularly, to a method for manufacturing a glass article with little remaining foam.

  For example, silicate glass is widely used as window glass for buildings and automobiles. In recent years, it is also used as a substrate for a display device such as a liquid crystal display device and a substrate for an information recording medium such as a hard disk drive.

  Common to these applications is to take advantage of the homogeneous properties of glass. However, if bubbles remain inside the glass, the homogeneity of characteristics will be impaired. As a result, defects such as a non-recordable area occur in the substrate application of the information recording medium, such as an appearance defect in the window glass application and a display defect in the substrate application of the display device. Therefore, there is a strong demand to reduce bubbles remaining inside the glass to a practically acceptable level at a minimum cost.

  At present, various technologies for reducing bubbles remaining in the glass have been developed and put into practical use. The technology is roughly divided into three.

  The first technique is the use of fining agents. A fining agent is an additive having an effect that when added to a glass batch, when the batch is melted, a glass melt with little or no bubbles is obtained. Bubbles are reduced by the clarifier because of the effect of expelling the gas generated when the raw material melts and vitrifies it from the glass melt, and the process of defoaming and homogenizing the glass melt. This is due to the effect of removing bubbles by growing, floating or absorbing large. Therefore, it is desirable that the fining agent generates gas in a relatively low temperature range where the vitrification reaction starts and in a relatively high temperature range where the glass melt is defoamed and homogenized.

Materials used as fining agents include well-known bow glass for alkali-containing silicate glass, and well-known arsenic oxide and antimony oxide for optical glass, low alkali glass and non-alkali glass, borosilicate glass, low alkali There are fluorides and chlorides that are sometimes used in glass or non-alkali glass. For example, in the borosilicate glass described in Japanese Patent Application Laid-Open No. 04-280833, one or more selected from As ₂ O ₃ , Sb ₂ O ₃ and NaCl as a fining agent is displayed in a weight percentage of 1 or more. It is disclosed that it can be added up to 0.0%.

  The second technique is defoaming of the glass melt. This is a method of reducing bubbles by causing bubbles in the glass melt to float up to the liquid surface by buoyancy and rupturing the bubbles at the liquid surface. The faster the bubble rises, the better the defoaming effect. The ascent rate is governed by Stokes' law and is proportional to the square of the bubble diameter and inversely proportional to the viscosity of the melt.

  As a method for increasing the bubble rising speed, a method of increasing the melting temperature and decreasing the viscosity of the melt is well known. There has also been proposed a method for increasing the diameter of bubbles by reducing the pressure of the glass melt. For example, Japanese Patent Laid-Open No. 02-221129 discloses an apparatus for retaining a glass melt therein and defoaming the glass melt under reduced pressure.

  The third technique is reboil suppression. Reboiling is a phenomenon in which a once clarified glass melt foams again. This occurs because the solubility of the gas component dissolved in the glass melt changes with changes in temperature and the like.

To suppress reboil, operate the melting furnace so that the solubility of the gas component does not change carelessly, lower the dissolved amount of the gas component in the glass melt, and add a reboil inhibitor to the glass melt. , Etc. are taken. For example, in JP-A 06-329421 _{discloses, SiO 2, Al 2 O 3} , MgO when melting high strength glass whose main component, 0.05 to 1% by weight of the halide to inhibit the reboiling In particular, it is disclosed that the addition of NaCl to the batch is preferred. A report published in Advances in fusion and processing of glass, vol. 29, (1993) p. 403-8 by S. Nakajima et al. Was used to clarify a glass melt containing SO ₃ and NaCl. Describes the reboil characteristics under reduced pressure.

  However, the conventional techniques for reducing residual bubbles have the following problems.

  In the case of bow glass known as a fining agent for alkali-containing silicate glass, increasing the amount of addition of bow glass to the glass melt tends to reduce the number of bubbles in the glass melt. However, if the amount added is too large, it may induce reboil and conversely increase the residual bubbles of the manufactured glass article. Therefore, there is an upper limit to the amount of bow glass added. Furthermore, there is a case where the minimum amount of addition of bow glass necessary for reducing the number of bubbles in the glass melt exceeds the upper limit of the amount of addition of bow glass necessary for suppressing reboil. In this case, the effect as a refining agent is insufficient with bow glass alone.

  Further, it has been pointed out that arsenic oxide, which is well known for the above-mentioned low alkali glass and the like, has a large load on the environment in recent years with increasing environmental awareness. Similarly, the well-known antimony oxide should also consider the environmental load. Therefore, the use of these fining agents should be avoided as much as possible.

  In addition, the method of increasing the melting temperature in order to increase the rising speed of bubbles in the melt has a problem that a large amount of energy such as fuel is consumed in order to increase the temperature. Further, when the temperature is raised, for example, the furnace material of the melting furnace is rapidly deteriorated, so that the glass melt is contaminated and the repair cost of the furnace becomes high. In addition, the manufacturing apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 02-221129 has a drawback that the apparatus itself is expensive and the apparatus itself is expensive, and the operation is also expensive. Further, by reducing the pressure, a component that easily volatilizes in the glass melt is selectively volatilized from the melt surface, and the composition of the glass melt is different from that intended.

  In view of these circumstances, an object of the present invention is to provide a method for producing a glass article that has a small load on the environment and can be defoamed and clarified easily at low cost.

  As a result of repeated investigations on the clarification effect by the clarifier, the present inventors have a small amount of clarifier compared to the total amount of the batch, so the clarifier may not be in a place where the effect should be exerted. I made the hypothesis. In addition, the inventors found that the glass melt has more bubbles when the batch made only of cullet is melted than when the batch made of glass raw material other than cullet is melted. It was noticed that this was particularly noticeable when no agent was used.

  At first glance, it is considered that bubbles are increased when a normal glass raw material with fine grains is melted. However, in reality, this is often not the case. Glass raw materials other than cullet usually contain compounds (carbonates and sulfates) that decompose and generate gas when heated. Bubbles gradually grow when outgassing occurs in the glass melt due to decomposition of these compounds. Largely grown bubbles can escape from the glass melt relatively easily because of the high ascent rate. On the other hand, when a batch consisting only of cullet is melted, such a phenomenon cannot be expected, and the air existing between the cullet grains and the gas dissolved in the cullet cannot easily escape from the glass melt.

  Based on these findings, the present inventors have found that if a clarifier is present in the immediate vicinity of the cullet contained in the batch, the clarifier can sufficiently exert its clarification action in the initial stage of melting of the batch. Thought. Based on this idea, an attempt was made to place a fining agent in the vicinity of the cullet, that is, to attach a fining agent to the cullet in advance and to melt a batch containing the cullet with the fining agent attached thereto. As a result, it was found that a glass melt having significantly less bubbles can be obtained as compared with the conventional method in which a fining agent is simply added to a batch, and the present invention has been completed.

  That is, this invention provides the manufacturing method of the glass article which melts the batch for melting containing the clarifier adhesion | attachment cullet which made the clarifier adhere to the surface.

  According to the present invention, a glass article having few defects such as bubbles can be provided easily and with a small environmental load. This is because in the method for producing a glass article of the present invention, the bubble removal at the time of melting can be improved only by melting a melting batch containing a cullet having a fining agent attached to the surface. Therefore, it becomes possible to manufacture a glass article with high foam quality without using a special clarification technique such as decompression or a clarifier having a large environmental load such as arsenic oxide.

  By the way, the above-mentioned report by S. Nakajima et al. Shows that if the silicate glass contains too much fluoride or chloride, the glass melt tends to reboil and the residual bubbles of the glass article tend to increase. is there. However, according to the method of the present invention, since the clarification action of the clarifier can be maximized, the amount of the clarifier used can be kept to the minimum necessary. It is also possible to balance the reduction.

  Examples of the clarifying agent to be attached to the cullet include metal halides whose cations are metal ions and anions are halide ions, or metal sulfates whose anions are sulfate ions. Of the metal halides, metal chlorides are preferred. Examples of metal ions include alkali metal ions and alkaline earth metal ions. In this case, the metal chloride can be an alkali metal chloride or an alkaline earth metal chloride. Specific examples include sodium chloride, potassium chloride, calcium chloride, and magnesium chloride. More preferred is an alkali metal chloride, and even more preferred is sodium chloride. Note that the fining agent need not be a pure substance of sodium chloride. For example, a compound in which the cation is one kind of metal ion selected from potassium, magnesium and calcium and the anion is a chloride ion or a sulfate ion, expressed in mass% with respect to the total amount of the fining agent, is 25 in total. % May be included.

  Moreover, it is preferable that 10-100 mass% of the above-mentioned fining agent adhesion cullets are contained in the batch for melting. When the batch for melting is (a) the whole amount is a clarifier adhering cullet, (b) a clarifier adhering cullet and a normal cullet which is a cullet without adhering a clarifier, (c) a clarifying agent adhering cullet And a glass raw material other than cullet (hereinafter also referred to as “normal glass raw material”), and (e) a case of consisting of a fining agent-attached cullet, a normal cullet, and a normal glass raw material.

That is, the melting batch can further include at least one selected from a normal cullet that is a cullet without a fining agent attached thereto, and a glass raw material other than the cullet (normal glass raw material). In this case, with respect to the total amount of the melting batch, the normal cullet content and the normal glass raw material content are
Normal cullet 0-80% by mass,
Glass raw materials other than cullet (usually glass raw materials) 0-80% by mass,
It can be. Furthermore, the sum of the normal cullet content and the normal glass raw material content can be 10 to 90% by mass.

Moreover, when a clarifier adhering cullet and a normal glass raw material are essential, and the normal cullet is an arbitrary material, the content of each material with respect to the total amount of the melting batch is preferably as follows.
Clarifier adhering cullet 10-80% by mass,
Normal cullet 0-70 mass%,
Normal glass raw material 10-90 mass%,
(Clarifier adhering cullet) + (normal cullet) 10-90% by mass

  The “normal cullet” refers to a cullet which is a glass particle obtained by crushing and pulverizing a glass composition and which does not have a fining agent attached thereto. The “ordinary glass raw material” is obtained by weighing and mixing industrial raw materials and natural minerals used as a raw material for glass so as to have a necessary composition ratio, and is other than cullet. As described above, the “batch for melting” is a clarifier adhering cullet itself, or a mixture of a clarifier adhering cullet and a normal glass raw material and / or an ordinary cullet so as to have a necessary composition ratio. It shall be used for the melting process.

  Moreover, in this invention, the clarifier adhesion cullet preparation process which makes a clarifier adhere to the surface of a cullet can be implemented.

  In the fining agent-attached cullet preparation step, a cullet is prepared in advance, and a sub-step of bringing the cullet into contact with an aqueous solution containing an alkali metal chloride can be performed. In this way, no special production equipment is required, and an alkali metal chloride (for example, sodium chloride) as a fining agent can be attached to the surface of the cullet very easily and inexpensively. Hereinafter, “alkali metal chloride aqueous solution” means “aqueous solution containing alkali metal chloride”.

  Specific methods for bringing the cullet into contact with the alkali metal chloride aqueous solution include a method of immersing the cullet in the alkali metal chloride aqueous solution, a method of mixing the alkali metal chloride aqueous solution and cullet, and the like. After the step of bringing the cullet and the alkali metal chloride aqueous solution into contact with each other, a step of drying the cullet (drying step) may be performed. The cullet may be dried by a method of naturally drying or by a method of introducing the cullet into an appropriate drying furnace. By doing so, the alkali metal chloride can be easily deposited (deposited) on the surface of the cullet.

  Also, the cullet and the aqueous alkali metal chloride solution can be brought into contact with each other by an operation of directly adding the glass melt into the aqueous alkali metal chloride solution. That is, the glass melt is solidified in an aqueous alkali metal chloride solution. The glass produced by quenching the glass melt is immediately crushed into cullet in an alkali metal chloride aqueous solution. If the cullet is pulled up from the alkali metal chloride aqueous solution and dried, or dried together with the alkali metal chloride aqueous solution, a fining agent cullet is obtained. If it does in this way, the process of producing a cullet and the process of contacting alkali metal chloride aqueous solution and cullet can be put together in one process. That is, it is not necessary to carry out a new process for producing a fining agent-attached cullet, and problems such as a decrease in productivity or an increase in cost due to an increase in the number of processes are unlikely to occur.

  Moreover, it is preferable that the density | concentration of the alkali metal chloride contained in the alkali metal chloride aqueous solution used at a fining agent adhesion cullet preparation process is 0.02-26 mass%, and it is further more preferable that it is 1-5 mass%. . By setting the concentration of the alkali metal chloride contained in the alkali metal chloride aqueous solution in such a range, the alkali metal chloride can be sufficiently adhered to the cullet. When alkali metal chloride aqueous solution is directly added to cullet and dried, or when alkali metal chloride is mixed with cullet and dried, almost all of the alkali metal chloride (clarifier) contained in the aqueous solution is cullet. It will adhere to the surface. On the other hand, when the cullet is dipped in the aqueous alkali metal chloride solution and then dried by lifting the cullet from the aqueous alkali metal chloride solution, the alkali metal chloride contained in the aqueous alkali metal chloride solution adhered to the surface of the cullet is removed. It will adhere to the cullet.

  By the way, the refining action of the metal chloride attached to the cullet on the glass melt is mainly caused by chlorine. Therefore, the amount of fining agent to be attached to the cullet can be considered by replacing it with the amount of chlorine. That is, a batch for melting containing a fining agent cullet contains 0.01 to 2.1% by mass (preferably 0.01 to 1% by mass, more preferably 0.01 to 0.3% by mass) of chlorine. It is desirable to do. Even when the production method of the present invention is employed, if the amount of chlorine adhering to the surface of the cullet is insufficient, the effect of reducing residual bubbles may not be sufficiently obtained. On the other hand, if the amount of chlorine is too large, reboil may be generated.

  In addition, it is desirable that the chlorine content of the manufactured glass article is 70% or less with respect to the chlorine content of the melting batch.

  Moreover, the glass article which can employ | adopt the manufacturing method of this invention suitably may be a glass article which consists of a silicate glass composition. Specifically, the silicate glass composition which has the following composition by the mass% display can be illustrated. It should be noted that a component whose lower limit value includes zero is an arbitrary component.

(First composition)
SiO ₂ 65~80%,
Al ₂ O ₃ 0-5%,
Na ₂ O 10-18%,
K ₂ O 0-5%,
MgO 0-10%,
CaO 5-15%,
Other ingredients 0-5%

(Second composition)
SiO ₂ 52~73%,
Al ₂ O ₃ 6-17%,
Li ₂ O 3-8%,
Na ₂ O 7-22%,
K ₂ O 0-3%,
MgO 0.06-4%,
CaO 0.8-8%,
Other ingredients 0-5%

(Third composition)
SiO ₂ 50~70%,
Al ₂ O ₃ 0.5-10%,
ZrO ₂ 0-5%,
TiO ₂ 0-0.1%,
Na ₂ O 1.5-5%,
K ₂ O 5-15%,
MgO 0.1-10%,
CaO 1-15%,
SrO 0-15%,
BaO 0.1-10%,
R ₂ O 6.5-15% where R ₂ O = Na ₂ O + K ₂ O,
MO 10-25%, where MO = MgO + CaO + SrO + BaO,
Other ingredients 0-5%

(Fourth composition)
SiO ₂ 40-70%,
Al ₂ O ₃ 5-20%,
B ₂ O ₃ 5-15%,
MgO 0-5%,
CaO 0-10%,
SrO 0-10%,
BaO 0-30%,
ZnO 0-5%,
Li ₂ O 0-0.5%,
Na ₂ O 0-0.5%,
K ₂ O 0-0.5%,
R ₂ O 0-0.5% where R ₂ O = Li ₂ O + Na ₂ O + K ₂ O,
MO 5-30%, where MO = MgO + CaO + SrO + BaO + ZnO,
Other ingredients 0-5%

  Hereinafter, the present invention will be described with specific examples. Here, sodium chloride is used as a fining agent, but the present invention is not limited to this, and the same effect can be obtained by using other alkali metal chlorides, alkaline earth metal chlorides, or mixtures thereof. Note that you can get

[First embodiment]
The first embodiment shows a method for producing a glass article with improved foam quality by melting a sodium chloride adhering cullet with sodium chloride attached as a fining agent, thereby improving the clarity of the glass melt. is there.

(Normal cullet production process)
Normal cullet having the composition shown in Table 1 was prepared by the following steps. First, batches were prepared using ordinary industrial materials and reagents as starting materials. The batch was put into a platinum crucible and melted in an electric furnace maintained at an atmospheric temperature of 1450 ° C. The melted glass was kept in the electric furnace for 2 hours to achieve a certain degree of fining. The clarified glass melt was poured into a stainless steel bucket containing city water. At this time, the flow of the glass melt was set to about 1 cm in width, the flow of the glass melt was not interrupted, and the poured glass melt was not set in one place. By doing so, the glass melt was rapidly cooled to obtain a granulated cullet that was crushed into small pieces having a particle size of about 8 mm or less. The granulated cullet was dried to obtain a normal cullet.

(Normal cullet composition ratio)

(Sodium chloride adhering cullet production process)
The normal cullet obtained in the above-described steps was brought into contact with a sodium chloride aqueous solution having a predetermined concentration by the method shown in Examples 1 to 11 and Comparative Example 1 in Table 2, and then naturally dried in the atmosphere, and the sodium cullet adhered cullet. Got. The mass of the obtained sodium chloride-attached cullet was measured, the increase in mass from the original cullet 30 g was examined, and the proportion of chlorine contained in the sodium chloride-attached cullet (chlorine concentration in the melting batch) was estimated. In addition, the comparative example 1 of Table 2 is the normal cullet itself which has not implemented the process made to contact sodium chloride aqueous solution.

(Melting process and cooling process)
This sodium chloride adhesion cullet was melted as it was as a batch for melting. Specifically, the sodium chloride adhesion cullet obtained in the above-mentioned process is spread on a platinum boat having an internal dimension of 200 × 10 × 10 (unit: mm), and this boat is inserted into a temperature gradient furnace, The melting batch was melted. This melting batch is melted in a temperature gradient furnace at a maximum temperature of 1420 ° C. and a minimum temperature of 1160 ° C. along the length of the boat. The boat was allowed to stand in a temperature gradient furnace for 2 hours to sufficiently melt the melting batch, and then the boat was taken out from the furnace to rapidly cool and solidify the glass melt. In this way, the melting step and the cooling step were performed, and rod-shaped glass samples (Examples 1 to 11) having different melting temperatures (holding temperatures at the time of the melting step) along the longitudinal direction were obtained. Similarly, a glass sample of Comparative Example 1 was obtained using ordinary cullet itself.

(Examples and comparative examples according to the first example)

(Count of residual bubbles)
This glass sample was observed with a microscope having a magnification of 100 times, and the number of bubbles remaining in the glass at each portion along the longitudinal direction of the sample was counted. The number of remaining bubbles was the number of bubbles contained in a range of ± 5 ° C. centered on a specific temperature at the time of the melting process, that is, a range of ± 5 mm centered on a specific position in the longitudinal direction. The number of residual bubbles obtained in this way can be used as an index for comparing clarity between samples prepared under different conditions, and can also be used as a judgment material for actual production. Note that the temperature gradient of the glass melt in the boat was not constant, and the temperature change was steep on the low temperature side. Specifically, a temperature gradient of about 1 ° C./mm was exhibited at 1320 to 1420 ° C. On the other hand, at a temperature lower than 1320 ° C., the temperature gradient was as large as 1.5 to 1.6 ° C./mm, and the minimum temperature was 1160 ° C.

  Table 2 shows the relationship between the manufacturing method of the sodium chloride-attached cullet, the melting temperature and the number of residual bubbles. A glass sample produced using a batch for melting containing 0.01 to 2.1% by mass of chlorine had a sufficiently small number of residual bubbles and showed good results. As described above, the present example shows that the clarity is improved, and this result shows that a glass article excellent in foam quality can be manufactured even during mass production.

[Second Example]
The second embodiment shows a method for producing a glass article excellent in foam quality by improving the clarity of a glass melt by melting a batch for melting containing sodium chloride adhering cullet and a normal glass raw material. It is.

(Normal cullet production process)
Normal cullet having the composition shown in Table 1 was produced in the same process as in the first example.

(Sodium chloride adhering cullet production process)
The normal cullet obtained in the above-mentioned process was dried after contacting with a sodium chloride aqueous solution by the method shown in Examples 12 to 19 in Table 3 to obtain a sodium chloride-attached cullet. In addition, the comparative example 2 of Table 3 is not implementing the process made to contact sodium chloride aqueous solution.

(Normal glass raw material preparation process)
A normal glass raw material was prepared using ordinary industrial raw materials and reagents as starting materials so as to have the composition shown in Table 1 after heating.

(Batch preparation process for melting)
The batch for melting used for Examples 12-19 was obtained by mixing sodium chloride adhesion cullet and a normal glass raw material in the ratio shown in Table 3.

(Melting process and cooling process, count of residual bubbles)
The melting batch was melted and cooled in the same steps as in the first example, and glass samples of Examples 12 to 19 were obtained. Similarly, a glass sample of Comparative Example 2 was obtained using a mixture of normal cullet and normal glass raw material. Each glass sample was evaluated by the same method as in the first example, and the number of residual bubbles was counted.

  Table 3 shows the relationship between the method for preparing the melting batch, the melting temperature, and the number of residual bubbles. Glass samples (Examples 12 to 19) produced using a melting batch containing 0.01 to 0.3% by mass of chlorine had a sufficiently small number of residual bubbles and showed good results. As described above, the present example shows that the clarity is improved, and this result shows that a glass article excellent in foam quality can be manufactured even during mass production.

  In the second embodiment, sodium chloride adhering cullet and normal glass raw material are mixed to obtain a batch for melting. Of course, normal cullet can be used instead of normal glass raw material or together with normal glass raw material. It is.

(Examples and comparative examples according to the second example)

[Third embodiment]
In the third embodiment, in the operation of a continuous melting furnace for producing glass articles, a clarifier-attached cullet is manufactured from at least a part of the melted glass, and the clarifier-attached cullet is used as at least a part of a melting batch. Shows a method for producing a glass article that improves the clarity of the glass melt and has excellent foam quality.

(Comparative example: Operation without clarifier adhesion cullet)
In the melting furnace, a melting batch prepared so as to have the composition shown in Table 1 is heated from a raw material inlet provided at one end thereof. Burning heavy oil inside the melting furnace, melting the melting batch, and clarifying. The clarified glass melt is continuously taken out from a glass melt outlet provided at the other end of the melting furnace and formed into a glass article.

  At this time, in the vicinity of the furnace wall and bottom of the melting furnace, the temperature tends to be low, so that fining tends to be insufficient. If the glass melt with insufficient clarification flows out from the outlet, defects such as bubbles occur in the glass article. In order to effectively prevent this, a glass melt with insufficient clarification may flow out from the furnace wall or bottom of the melting furnace to another flow path. This operation is called ground sinking. By this operation, only a sufficiently clarified glass melt can be flowed to the take-out port.

  The ground glass is poured into a water tank filled with city water, solidified and crushed, and then dried to form cullet. The cullet is used as part of the melting batch and melted again.

  Further, the glass melt may not be taken out of the melting furnace due to the production plan of the glass article and the convenience of the forming apparatus, but the operation of the melting furnace cannot be stopped just because the glass melt is not taken out. In this case, a large amount of glass melt is left, but the remaining glass melt may be all washed away to produce cullet.

(Example: Operation using a fining agent cullet)
In the operation of the melting furnace described above, the ground glass is poured into a water tank filled with seawater to be solidified and crushed. By drying the crushed glass, a clarifier adhering cullet (sodium chloride adhering cullet) having a non-volatile component of seawater attached to the surface is obtained. The non-volatile component of seawater is a main component of about 80% by mass of sodium chloride, and the remainder is a mixture of potassium, magnesium, calcium chloride or sulfate.

  Using the fining agent cullet as part of the melting batch, the melting furnace is operated in the same manner as in the prior art to obtain a glass melt. As a result of obtaining the above-mentioned clarification effect, the glass melt contains a small number of bubbles. By using this glass melt, a large amount of glass articles having excellent foam quality can be produced.

Claims (17)

  The manufacturing method of the glass article which melts the batch for melting containing the fining agent cullet which made the fining agent adhere to the surface.   The method for producing a glass article according to claim 1, wherein the fining agent is a metal chloride.   The method for producing a glass article according to claim 2, wherein the metal chloride is an alkali metal chloride.   The method for producing a glass article according to claim 3, wherein the alkali metal chloride is sodium chloride.   The manufacturing method of the glass article of Claim 1 in which the said clarifier adhesion | attachment cullet is contained in the said batch for melting 10-100 mass%.   The said batch for melting is a manufacturing method of the glass article of Claim 1 which further contains the normal cullet which is a cullet which has not made the clarifier adhere.   The method for producing a glass article according to claim 1, wherein the melting batch further includes a glass raw material other than cullet. The melting batch further includes at least one selected from a normal cullet that is a cullet without a fining agent attached thereto, and a glass raw material other than the cullet, and the content of the normal cullet and the glass raw material other than the cullet. Rate is,
Normal cullet 0-80% by mass,
Glass raw materials other than cullet 0-80% by mass,
And
The sum of the content of the normal cullet and the content of the glass raw material other than the cullet is 10 to 90% by mass,
The method for producing a glass article according to claim 1. The melting batch is
10-80% by mass of the fining agent cullet,
0 to 70% by mass of normal cullet which is a cullet with no clarifier attached,
10 to 90% by mass of glass raw materials other than cullet,
Including
The sum of the content of the clarifier adhering cullet and the content of the normal cullet is 10 to 90% by mass,
The method for producing a glass article according to claim 1.   The manufacturing method of the glass article of Claim 1 including the clarifier adhesion cullet preparation process which makes the said clarifier adhere to the surface of a cullet.   The said fining agent adhesion cullet preparation process is a manufacturing method of the glass article of Claim 10 including the sub process which makes the said cullet contact the aqueous solution containing the alkali metal chloride as said clarifier.   The said sub process is a process of crushing the glass obtained by adding a glass melt to the aqueous solution containing the said alkali metal chloride and solidifying, and solidifying the glass melt. A method for producing a glass article.   The manufacturing method of the glass article of Claim 11 in which the aqueous solution containing the said alkali metal chloride contains 0.02-26 mass% alkali metal chloride.   The manufacturing method of the glass article of Claim 13 in which the aqueous solution containing the said alkali metal chloride contains 1-5 mass% alkali metal chloride.   The manufacturing method of the glass article of Claim 2 in which the said batch for melting contains 0.01-2.1 mass% chlorine.   The method for producing a glass article according to claim 15, wherein the melting batch contains 0.01 to 0.3 mass% of chlorine. The glass article is expressed in mass%,
SiO ₂ 65~80%,
Al ₂ O ₃ 0-5%,
Na ₂ O 10-18%,
K ₂ O 0-5%,
MgO 0-10%,
CaO 5-15%,
Other ingredients 0-5%,
The manufacturing method of the glass article of Claim 1 which consists of a glass composition containing this.