JP5116024B2 - Manufacturing method of glass products with improved impact resistance - Google Patents

Description

  The present invention relates to a method for increasing the impact resistance of glass products such as glass bottles and glass tableware.

In glass, cracks called cones or blues occur due to local stress due to impact. In particular, a thick part is likely to crack. In the case of glass bottles, the mouth is mainly applicable. Since the bottle mouth is a place where consumers can directly touch, cracks are especially disliked and countermeasures are required.
On the other hand, wind cooling strengthening is known as a method for improving the strength against local stress. Patent Document 1 below discloses a tempered safety glass having a scratch-resistant and porous SiO ₂ antireflection layer and a method for producing the same. This glass is one in which a commonly used glass is coated with a colloidal dispersion solution, dried, heated to a temperature of at least 630 ° C. to remove organic components, and subsequently quenched for strengthening. Adhesion is improved by the porous SiO ₂ antireflective layer, while increasing the transmittance of visible light or other electromagnetic waves while simultaneously blocking and reducing unwanted reflections. In addition, it is strengthened by rapid cooling. This glass is used, for example, as a solar concentrator and a solar cell coating, an automobile windshield, a glass window of a building, and the like.
Japanese translation of PCT publication No. 2002-543028

  In the tempering method described in Patent Document 1 above, it is necessary to heat the glass to a high temperature of 630 ° C. in order to remove the organic components of the colloidal dispersion, and it is necessary to rapidly cool the glass for strengthening. In manufacturing a glass product, special equipment for that purpose is required, and the equipment cost and energy cost are high.

  The present invention is to develop a method that can be easily carried out on a conventional production line for glass bottles and glass tableware, has low energy costs, and can increase the impact resistance of glass products to a practically sufficient level. It was made.

(Claim 1)
The present invention, on the glass surface of the glass product is coated alkaline silica (SiO ₂₎ aqueous solution as a coating liquid, have a step of forming a silica film by drying, silica (SiO ₂₎ concentration of the coating liquid It is a method for producing a glass product with improved impact resistance , characterized by being 0.2 to 2.5 wt% .
The silica film formed on the glass surface increases the impact resistance, and the glass breakage rate when local stress is generated by the impact can be reduced.
The alkaline silica aqueous solution is prepared by melting a commercially available fine powdery silica, insoluble silicate, or silicon-containing glass in an alkali and dissolving it in water or an aqueous alkali solution. Alternatively, a commercially available silica or water-soluble silicate is dissolved in water or an alkaline aqueous solution. The alkali solution is not particularly limited as long as it can dissolve silica, such as sodium hydroxide solution and potassium hydroxide solution.
When the silica concentration of the coating solution is less than 0.2 wt%, the silica film becomes thin and the impact resistance effect becomes insufficient, and when it exceeds 2.5 wt%, the silica film is whitened and looks bad.
Drying after applying the coating solution may be natural drying or forced drying, but natural drying is usually sufficient.
The silica film is not necessarily formed on the entire surface of the glass product, and may be formed on a desired portion.

(Claim 2)
Moreover, this invention is a manufacturing method of the said Claim 1, The average temperature of the glass surface of the to-be-coated part when apply | coating the said coating liquid is a manufacturing method of the glass product which improved the impact resistance which is 60-150 degreeC. is there.
As for the average temperature of the glass surface of the to-be-coated part when apply | coating a coating liquid, 60-150 degreeC is preferable. If the temperature exceeds 150 ° C., the effect of reducing the breakage rate when local stress is generated by impact becomes low, and this is presumed to be due to damage to the glass itself due to thermal shock.

(Claim 3)
According to the present invention, in the manufacturing method according to claim 1, the manufacture of glass products average temperature of the glass surface of the coated part is enhanced impact resistance is 100 to 1 2 0 ° C. at the time of applying the coating liquid Is the method.
As for the average temperature of the glass surface of the to-be-coated part when apply | coating a coating liquid, 100-120 degreeC becomes more preferable. If it is less than 100 ° C., the silica film will not be dense and the moisture resistance will be insufficient. By making it in this range, the effect of reducing the breakage rate when local stress is generated due to moisture resistance and impact becomes extremely high.

(Claim 4 )
Moreover, the present invention provides the manufacturing method according to any one of claims 1 to 3 , wherein the glass product is a glass bottle or glass tableware, and the coating liquid is applied to the outlet of the slow cooling furnace in the glass bottle or glass tableware manufacturing line. A method for producing a glass product, which is carried out when the surface temperature of the coated portion of a glass bottle or glass tableware is within a predetermined range on the downstream side.
By applying the coating while the glass bottle or glass tableware is still hot at the downstream side of the slow-cooling furnace outlet in the glass bottle or glass tableware production line, it is not necessary to heat the glass and energy costs are unnecessary. Further, since there is usually cold end coating (coating of polyethylene or the like) equipment on the downstream side of the slow cooling furnace outlet, coating can be performed using this equipment, and equipment costs are also unnecessary.

According to the production method of the present invention, a dense silica film is formed on the surface of a glass product. This silica film can improve the impact resistance and reduce the glass breakage rate when local stress is generated by the impact.
Further, since the glass surface temperature when applying the coating liquid is relatively low, the energy cost may be low.
When the coating liquid is applied downstream of the outlet of the slow cooling furnace of a production line such as a glass bottle, energy costs and equipment costs are not required.

It is explanatory drawing of an impact test apparatus. It is explanatory drawing of the test result of Example 1. FIG. It is explanatory drawing of the test result of Example 2. FIG. It is explanatory drawing of an impact test apparatus. It is explanatory drawing of the test result of Example 3. FIG. It is explanatory drawing of the test result of Example 4. FIG. It is explanatory drawing of the test result of Example 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample 2 units 3 Prop 4 Cushion material 5 Steel ball 6 Pin 7 Arm 8 Weight 9 Arm 10 Jig 11 Sample

(Comparison with other coating solutions)
The substrate (soda lime glass plate having a thickness of about 4 mm) was heated by being left in an electric oven having an internal temperature of 125 ° C. for 1 hour or longer. The heated substrate was placed on a lokuro, rotated, and a coating solution was applied using a hand spray gun. The details of this coating process are as follows.
・ Rotation speed of Lokuro: 1 rotation / second ・ Hand spray gun: Iwata W71
・ Flow rate: 5 ml / min ・ Application time: 4 seconds ・ Drying: 100 ° C. for 20 minutes

The Example which performed said coating process and Comparative Examples 1-3 were prepared.
Example: Fine powdery silica (SiO ₂ ) was dissolved in a sodium hydroxide solution to prepare a stock solution of pH 11 containing 25 wt% silica. This stock solution was diluted 100 times with distilled water to obtain a coating solution. The coating solution had a silica concentration of 0.25 wt%, and was coated by the method described in the previous paragraph to form a silica film on the substrate surface.
Comparative example 1
An untreated base material that was not subjected to the coating treatment of the previous paragraph was designated as Comparative Example 1.
Comparative Example 1-2
As the coating liquid, a surfactant having a solid content concentration of 0.4% was used, and the coating treatment was performed by the method described in the previous paragraph.
Comparative Example 1-3
A polyethylene agent having a solid content concentration of 0.4% was used as the coating liquid, and the coating treatment was performed by the method described in the previous paragraph.

The impact test was done with respect to the above Examples and Comparative Examples 1 to 1-3 to evaluate the damage rate against the impact.
FIG. 1 is an explanatory diagram of an impact test apparatus. A stand in which a column 3 is erected on a table 2 is prepared, a cushion material 4 (rubber plate) is laid on the table 2, and a sample 1 is placed thereon. On the sample 1, a pin 6 having a steel ball 5 (φ3 mm) fixed to the tip is supported by an arm 7 protruding from the column 3 so as to be movable up and down. Above the pin 6, a weight (weight 134 g) 8 is supported by an arm 9. The support of the weight 8 is released, the weight 8 is freely dropped, and it is made to collide with the pin 6 to apply an impact to the sample 1 to determine whether or not a crack (cone) has occurred in the sample 1. The falling height h of the weight 8 was 10 mm.

Five samples of each of Examples and Comparative Examples 1 to 1-3 were prepared, and an impact test was performed at 20 locations on each glass plate. Therefore, the total number of tests n is 5 × 20 = 100 for the examples and the comparative examples.
The resulting damage rate is shown in Table 1. In Table 1, “minimum value” and “maximum value” are the minimum value and the maximum value of the damage rate obtained for each glass plate, and “average” is the failure rate of the entire five glass plates. Moreover, the result of Table 1 is represented on a graph and shown in FIG.

  The surfactants and polyethylenes of Comparative Examples 1-2 and 1-3 are coatings that have been applied to the glass bottle barrel at the cold end to impart lubricity. However, there is no effect on local stress that is applied with the impact fixed vertically. Rather, due to thermal shock during coating, the breakage rate is higher than that of Comparative Example 1 that was not treated. As compared with any of the comparative examples, the example has a remarkably small breakage rate, and the effect of improving the impact resistance is proved.

(Influence of silica solution concentration)
The substrate (a soda-lime glass plate having a thickness of about 4 mm) was heated in an electric oven having an internal temperature of 125 ° C. for 1 hour or longer. The heated substrate was placed on a lokuro, rotated, and a coating solution was applied using a hand spray gun. The details of this coating process are as follows.
・ Rotation speed of Lokuro: 1 rotation / second ・ Hand spray gun: Iwata W71
・ Flow rate: 5 ml / min ・ Application time: 4 seconds ・ Drying: 80 ° C. for 3 minutes

Three kinds of coating solutions having different concentrations were coated by the method described in the previous paragraph, and five kinds of three examples were prepared.
Example 2-1: The stock solution was diluted 10 times with distilled water and used (SiO ₂ concentration 2.5 wt%, PH 10.8).
Example 2-2: The stock solution was diluted 50 times with distilled water (SiO ₂ concentration 0.5 wt%, PH 10.5)
Example 2-3: The stock solution is diluted 100 times with distilled water (SiO ₂ concentration 0.25 wt%, PH 10.2)
Five of each of these three types of examples were prepared, and an impact test was performed using the impact test apparatus shown in FIG. The results are shown in Table 2. In Table 2, Comparative Example 1 is an untreated substrate that does not perform the treatment of the previous paragraph at all. “Minimum value” and “maximum value” are the minimum value and the maximum value of the damage rate obtained for each glass plate, and the average is the failure rate of the entire five glass plates. Moreover, the result of Table 2 is represented on a graph and shown as FIG.

  There was no damage when the silica concentration was 2.5 wt%. Even at a silica concentration of 0.25 wt%, the breakage rate was only 2%, showing an 80% breakage reduction effect compared to untreated glass (breakage rate 10%). Thereby, the failure rate reduction effect at a silica concentration of 0.25 to 2.5 wt% was demonstrated.

(Evaluation of bottle temperature in glass bottles)
The substrate (glass bottle) was heated by being left in an electric oven at a certain temperature for 1 hour or longer. The warmed substrate was sprayed with the coating solution using an experimental coating apparatus. The details of this coating process are as follows.
-Spray nozzle: Needle spray gun-Flow rate: 50 ml / min-Electric oven temperature: Four levels of 90, 110, 130, and 150 ° C.
-Coating solution: The stock solution is diluted 100 times with distilled water (SiO ₂ concentration 0.25 wt%)

The following five types of examples were prepared for each of the differences in heating temperature.
Example 3-1: heating temperature 90 ° C.
Example 3-2: heating temperature 110 ° C.
Example 3-3: heating temperature 130 ° C.
Example 3-4: Heating temperature 150 ° C.

An impact test was performed on the above Examples 3-1 to 3-4, and a breakage rate against the impact was evaluated.
FIG. 4 is an explanatory diagram of the impact test apparatus. A stand having a column 3 upright on a table 2 is prepared, a jig 10 is placed on the table 2, and a sample 11 is placed thereon. Thereby, the sample 11 is set in a state inclined by 45 °. A pin 6 having a steel ball 5 (φ3 mm) fixed to the tip is supported on the mouth (threaded portion) of the sample 11 and supported by an arm 7 protruding from the support column 3 so as to be movable up and down. Above the pin 6, a weight (weight 134 g) 8 is supported by an arm 9. The support of the weight 8 is released, the weight 8 is freely dropped, and it is made to collide with the pin 6 to apply an impact to the mouth portion (screw portion) of the sample 11, and it is determined whether or not a crack (cone) has occurred at that time. The falling height h of the weight 8 was 10 mm.

An impact test was conducted at 16 points on each one glass bottle of 5 examples. Therefore, the total number of tests n is 5 × 16 = 80.
The resulting damage rate is shown in Table 3. In Table 3, “minimum value” and “maximum value” are the minimum value and the maximum value of the breakage rate obtained for each glass bottle, and the average is the breakage rate of the entire five glass bottles. Moreover, the result of Table 3 is represented on a graph and shown as FIG.

  Compared to Comparative Example 1 described above, it is recognized that there is an effect of reducing the breakage rate at a heating temperature of 90 to 150 ° C. In particular, the damage rate reduction effect at 110 ° C. (Example 3-2) is excellent. Therefore, the coating liquid is most preferably applied to the glass surface having an average temperature of 100 to 120 ° C.

(Evaluation of bottle temperature in glass bottle production line)
The glass bottle formed in the glass bottle production line was coated on the downstream side (cold end) of the outlet of the slow cooling furnace. The average surface temperature of the bottle during coating was two levels of 110 ° C. and 60 ° C. The details of this coating process are as follows.
Spray nozzle: needle spray gun flow rate: 50 ml / min coating solution was diluted 100-fold the stock solution with distilled water, was used in SiO ₂ concentration of 0.25 wt%.
The coated glass bottles were stored at two levels of room temperature for 2 weeks (indoor storage) and at a temperature of 70 ° C. and a humidity of 90% for 3 hours (high temperature and humidity storage) to obtain the following examples. Further, as Comparative Example 4, a glass bottle that was not subjected to coating treatment was prepared.
Example 4-1: Coating temperature 110 ° C., room temperature storage Example 4-2: Coating temperature 110 ° C., temperature 70 ° C. Humidity 90% storage Example 4-3: Coating temperature 60 ° C., room temperature storage Example 4-4: Coating temperature 60 ° C., temperature 70 ° C., humidity 90% storage Comparative example 4: No coating (no treatment)

For each example and comparative example 4, 20 bottles were prepared, and an impact test was performed on each bottle at 16 locations using the impact test apparatus shown in FIG. Therefore, the total number of tests n is 20 × 16 = 320 for each example and comparative example.
The results are shown in Table 4. In Table 4, "Minimum value" and "Maximum value" are the minimum value and maximum value of the breakage rate obtained for each glass bottle, and "Average" is the breakage rate of the entire 20 glass bottles. Moreover, the result of Table 4 is represented on a graph and shown as FIG.

  In Example 4-4 (coating temperature 60 ° C., temperature 70 ° C., humidity 90% storage), the breakage rate is large and it can be seen that there is a problem with moisture resistance. Therefore, the glass surface average temperature during coating is preferably 90 ° C. or higher, more preferably 100 to 120 ° C.

(Evaluation of coating flow rate in glass bottle production line)
The glass bottle formed in the glass bottle production line was coated on the downstream side (cold end) of the outlet of the slow cooling furnace. The glass bottle surface average temperature at the time of coating was set to 110 ° C., and the flow rate of the coating liquid was measured at the following three levels. The details of this coating process are as follows.
Spray nozzle: needle spray gun flow rate: 30,50,70Ml / min coating solution was diluted 100-fold the stock solution with distilled water, was used in SiO ₂ concentration of 0.25 wt%.
-Example 5-1: Flow rate 30 ml / min-Example 5-2: Flow rate 50 ml / min-Example 5-3: Flow rate 70 ml / min-Comparative example 5: No coating (no treatment)

For each of the examples and comparative examples, 20 bottles were prepared, and an impact test was performed on each bottle at 16 locations using the impact test apparatus shown in FIG. Therefore, the total number of tests n is 20 × 16 = 320 for each example and comparative example.
The results are shown in Table 5. In Table 5, “Minimum value” and “Maximum value” are the minimum value and maximum value of the damage rate obtained for each glass bottle, and “Average” is the failure rate of the entire 20 glass bottles. Moreover, the result of Table 5 is represented on a graph and shown as FIG.

  There was little change in the damage rate due to the flow rate of the coating liquid. Accordingly, the flow rate may be an amount that does not cause the coating liquid to adhere to the glass surface evenly and does not cause dripping, that is, a flow rate that is the same as that of a coating process that is normally performed, and there is no need to provide any particular limitation.

  In addition to glass bottles and glass tableware, the present invention can also be used as a method for producing flat glass.

Claims (4)

The glass surface of the glass product, coated alkaline silica (SiO ₂₎ aqueous solution as a coating liquid, have a step of forming a silica film by drying, 0.2 silica (SiO ₂₎ concentration of the coating liquid A method for producing a glass product with improved impact resistance , characterized by being 2.5 wt% . The manufacturing method of Claim 1 WHEREIN: The manufacturing method of the glass product which improved the impact resistance whose average temperature of the glass surface of the to-be-coated part when apply | coating the said coating liquid is 60-150 degreeC. The manufacturing method of Claim 1 WHEREIN: The manufacturing method of the glass product which improved the impact resistance whose average temperature of the glass surface of the to-be-coated part when apply | coating the said coating liquid is 100-120 degreeC. The manufacturing method according to any one of claims 1 to 3 , wherein the glass product is a glass bottle or glass tableware, and the coating liquid is applied downstream of the outlet of the slow cooling furnace in the glass bottle or glass tableware production line. Or the manufacturing method of the glass product which improved impact resistance characterized by performing when the surface temperature of the to-be-coated part of glass tableware exists in a predetermined range.

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