Glass container and method and apparatus for its manufacture

Abstract

Glass containers (10), containing: a container main body made of glass (12); and a coating film formed on a surface of the main body of the container (12), which is made of tin oxide or titanium oxide, wherein the coating film has a film thickness in the range of 40 nm to 50 nm and a scratch resistance of 8 kg or more, and in a depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, the atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less, where the scratch resistance of the coating film is measured by: Placing a sample A horizontally on a weighing instrument; Touching sample B with sample A; Rubbing sample B in the direction from a body part to an opening part of sample A, while maintaining a condition in which sample B is subjected to an arbitrary load from above; If no scratch appears on the surface of sample A, repeat the rubbing, increasing the pressure by 1 kg; Determine a load that causes a scratch on the surface of sample A.

Description

TECHNICAL AREA

[0001] The invention relates to a glass container having a coating film with excellent scratch resistance and alkali resistance, so that scratching of the glass container can be prevented, as well as a method and a device for manufacturing the same. STATE OF THE ART

[0002] Glass containers can be scratched on the surface, and their appearance can be deteriorated by contact between glass or other objects. Furthermore, scratches can cause chipping or breakage. Glass containers used commercially are often transported in large quantities, which can lead to them colliding and scratching. Repeated use exacerbates these scratches, often resulting in chipping and breakage. Additionally, if a glass container experiences a temperature difference due to dishwasher use, a scratch can become the starting point for breakage, ultimately leading to shattering.

[0003] Therefore, techniques for strengthening glass have been developed to prevent such scratches and increase the strength of glass containers. A typical strengthening technique is chemical strengthening, which involves replacing alkali ions in the glass with other alkali ions to form a pressure-resistant layer on the glass surface. However, since chemical strengthening is a secondary treatment performed on molded and gradually cooled products, it is time-consuming and expensive. Furthermore, the pressure-resistant layer formed on the surface of the glass product by chemical strengthening is thin, so the expected hardness and scratch resistance cannot be achieved, and sufficient scratch resistance is not attained.

[0004] A technique for increasing scratch resistance by forming a coating film of tin oxide or titanium oxide on the glass surface of a glass bottle is already known. In the case of a conventional disposable bottle, a coating film of an oxide such as tin oxide or titanium oxide, approximately 12 nm to 15 nm thick, is formed on the glass surface immediately after the bottle is manufactured and before gradual cooling. Since this coating film alone does not provide sufficient scratch resistance, a polyethylene-based resin coating film is subsequently formed on top of the oxide coating film after gradual cooling to impart scratch resistance. However, bottles treated in this way do not have sufficient alkali resistance, and in particular, the polyethylene-based resin components are immediately dissolved by an alkaline cleaning fluid.Furthermore, if the bottle is repeatedly washed in a dishwasher, the oxide coating film easily detaches, and a rainbow phenomenon and a fading phenomenon also occur.

[0005] Accordingly, a method was proposed by which a glass bottle with an outer surface temperature of 550°C to 700°C and a film-forming starting material containing SnO2 or TiO2 as a major component are brought into contact to form a film containing SnO2 or TiO2 as a major component and having a thickness of 40 nm to 100 nm (PTL 1). Although a glass bottle produced by this method has improved alkali resistance, the alkali resistance remains insufficient after repeated washing in a dishwasher, and the scratch resistance is also inadequate. Furthermore, the glass bottle produced by this method is not suitable for a glass container where aesthetic appearance is paramount, as a rainbow effect is likely to occur with a thick coating film.

[0006] PTL 2 and PTL 3 propose treatment methods for obtaining a glass bottle with excellent alkali resistance and a coating film that is not so thick as to cause a rainbow effect. PTL 2 discloses a glass bottle on which a coating film of tin oxide or titanium oxide with a film thickness of 8 nm to 40 nm is formed, and PTL 3 discloses a glass bottle on which a tin oxide film with a film thickness of 10 nm to 40 nm is formed. Furthermore, PTL 4 discloses glassware on which an oxide coating film with a thickness of 1 nm to 30 nm is formed. With the methods described in PTL 2 to 7 and PTL 3, respectively, the glass bottles are treated in a way that produces a glass bottle with excellent alkali resistance and a coating film that is not so thick as to cause a rainbow effect.However, the techniques disclosed in NPL 1 cannot achieve the hardness and scratch resistance of the coating films required for practical use, so that sufficient scratch resistance as a glass container cannot be achieved and alkali resistance sufficient to withstand repeated washing processes cannot be achieved.

[0007] PTL 5 discloses a method for manufacturing bottles that can uniformly distribute the temperature on the outer surface of a bottle during transport. The bottle is conveyed from a bottle-making machine to a hearth or oven so that coating can be carried out. PTL 5 further discloses an apparatus for carrying out the bottle-making method and a bottle-coating apparatus.

[0008] PTL 6 describes a process for the uniform coloring of glassware such as glass bottles with easy color change. After shaping in the glassware manufacturing process, a glass object is sprayed with a color coating fluid while being held at a temperature of 500 to 650°C before being slowly cooled, resulting in the formation of a colored layer on the surface of the glass object. The coating fluid consists of an organic solvent with dissolved metal compounds, making it possible to form a uniform colored layer on the surface of the high-temperature glass object within a short time.

[0009] Another generic method for sealing a glass container is disclosed in PTL 7. PRINTED PUBLICATIONS PATENT LITERATURE PTL 1: JP H03 - 131 547 A PTL 2: JP 2000-302 483 A PTL 3: JP 2001-146 438 A PTL 4: JP H08 - 133 786 A PTL 5: DE 698 24 357 T2 PTL 6: JP 2008 - 74 477 A PTL 7: US 9 162 780 B2 NON-PATENT LITERATURE

[0010] NPL 1: Z. Farago, “Fuel Combustion”, 11.2015, URL http: / / www.farago.info / job / Verbrennungen / DritteBrenner.htm BRIEF DESCRIPTION OF THE INVENTIONAL PROBLEM

[0011] It is an object of the invention to provide a high-strength glass container in which, as a result of the formation of an oxide coating film that exhibits excellent scratch and alkali resistance and does not produce a rainbow effect, the aesthetic appearance of the glass container is not impaired, fading does not occur even with repeated use in a dishwasher, scratches are prevented, and breakage of the glass container is reduced. A further object of the invention is to provide a method and an apparatus for manufacturing such a glass container. SOLUTION TO THE PROBLEM

[0012] According to a first aspect of the invention, a glass container according to claim 1 is provided. According to a second aspect of the invention, a method for manufacturing a glass container according to claim 6 is specified. Further aspects of the invention are the subject of the dependent claims, the drawings, and the description of exemplary embodiments.

[0013] A glass container according to one embodiment of the invention contains: a container body made of glass; and a coating film formed on a surface of the main container body, made of tin oxide or titanium oxide, wherein the coating film has a film thickness in the range of 40 nm to 50 nm and a scratch resistance of 8 kg or more and in a depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, the atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less.

[0014] The scratch resistance of the coating film is measured by: Placing a sample A horizontally on a weighing instrument; Touching sample B with sample A; Rubbing sample B in the direction from a body part to an opening part of sample A while maintaining a condition in which sample B is subjected to an arbitrary load from above; If no scratch appears on the surface of sample A, repeat the rubbing, increasing the pressure by 1 kg; Determine a load that causes a scratch on the surface of sample A.

[0015] The coating film on the glass container can achieve a surface hardness in the range of 7000 N / mm². 2 up to 8500 N / mm 2 have been determined by an extremely low stress hardness test in accordance with JIS Z 2255:2003.

[0016] The coating film on the glass container can have a surface roughness of 15 nm or less, as measured by an atomic force microscope (AFM).

[0017] In the case of the glass container, the coating film can be formed on at least one outer surface of the main container body.

[0018] The glass container can be a jug, a pitcher, a bowl, a dish, a stemmed glass (glass with a foot), a beer mug or a bottle.

[0019] A method for manufacturing a glass container according to an embodiment of the invention includes: a first step in which a main container body made of glass is formed; a second step in which heat treatment is carried out while the main container body is held at a temperature of 580°C or higher to desorb sodium from a surface area of ​​the main container body; and a third step in which a coating film of tin oxide or titanium oxide with a film thickness in the range of 40 nm to 50 nm is formed on a surface of the main container body.

[0020] In the process for manufacturing a glass container, the temperature of the main container body in the second step can range from 600°C to 770°C.

[0021] In the process for manufacturing a glass container, the heat treatment in the second step can be a flame treatment.

[0022] In the process for manufacturing a glass container, the flame temperature during flame treatment is in the range of 1250°C to 1600°C and the flame contact time is in the range of 0.5 s to 2 s. Furthermore, during flame treatment, the flame temperature can be in the range of 1290°C to 1580°C and the flame contact time can be in the range of 0.8 s to 2 s.

[0023] An example of a device for making a glass container includes: a forming device that forms a container body made of glass; a heating device that heats the main container body formed by the molding device while the main container body is rotated; a coating film forming device that forms a coating film of tin oxide or titanium oxide on a surface of the main container body, which is heat-treated by the heating device; and a device for gradual cooling that gradually cools the glass container on which the coating film has been formed.

[0024] In a device for manufacturing a glass container, the heating device can be a burner.

[0025] In the device for manufacturing a glass container The heating device and the coating film formation device can be provided along a conveyor system; and The conveying device can have a multitude of tables on which the main container body and the glass container can be placed and which are rotatable in a predetermined direction, wherein the multitude of tables are arranged in a loop shape and are continuously movable in a predetermined direction. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0026] According to the invention, it is possible to provide a high-strength glass container in which, as a result of the formation of an oxide coating film that exhibits excellent scratch and alkali resistance and does not produce a rainbow effect, the aesthetic appearance of the glass container is not impaired, fading does not occur even with repeated use in a dishwasher, scratches are prevented, and breakage of the glass container is reduced. According to the invention, it is further possible to provide a method and a device for manufacturing such a glass container. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view that schematically depicts a device for manufacturing a glass container according to one embodiment. Fig.Figure 2 is a cutaway view that schematically represents an example of a glass container according to one embodiment. Fig. Figure 3 is a diagram representing a depth profile according to an embodiment, determined by XPS analysis. Fig. Figure 4 is a diagram that represents a depth profile according to a comparative example determined by XPS analysis. Fig. Figure 5 is a diagram illustrating the relationship between the flame temperature and the flame treatment time of samples according to the examples and comparison examples. Fig. Figure 6 is a diagram showing the relationship between the flame temperature and the flame treatment time of samples according to the comparison examples. Fig. Figure 7 is an electron micrograph of the surface of a coating film according to an example. Fig.Figure 8 is an electron micrograph of the surface of a coating film according to a comparative example. Fig. Figure 9 is an image obtained using an atomic force microscope, according to an example. Fig. Figure 10 is an image obtained through an atomic force microscope, according to an example. Fig. Figure 11 is an image obtained through an atomic force microscope, according to an example. Fig. Figure 12 is an image obtained through an atomic force microscope, according to an example. Fig. Figure 13 is an image obtained through an atomic force microscope according to a comparative example. Fig. Figure 14 is an image obtained through an atomic force microscope according to a comparative example. Fig. Figure 15 illustrates a method for measuring scratch resistance. Fig.Figure 16 is a diagram illustrating the relationship between the film thickness of the coating film and the scratch generation load in relation to scratch resistance. Fig. Figure 17 is a diagram illustrating the relationship between the temperature of the container body and the scratch generation load during the heating step in scratch resistance. DESCRIPTION OF EXECUTION FORMS

[0027] Exemplary embodiments of the invention are described below, but the invention is not limited to these embodiments. 1. Device and method for manufacturing a glass container 1.1. Manufacturing device

[0028] First, a device for manufacturing a glass container according to an embodiment of the invention is described. Fig. Figure 1 schematically shows an example of a manufacturing device 1000 according to an embodiment of the invention.

[0029] How Fig.Figure 1 shows that the manufacturing device 1000 includes a forming device 100 for forming a glass container body 12, a heating device 200 for heating the container body 12, a coating film forming device 300 for forming a film of tin oxide or titanium oxide on the surface of the container body 12, and a cooling device 500 for gradually cooling the glass container 10 on which the coating film has been formed. The heating device 200 and the coating film forming device 300 are arranged along a conveying device 400.

[0030] The forming device 100 has a table 120 rotatably mounted on a holding part 110 and a plurality of molds 130 arranged on the table 120. Above the table 120 are a vertically movable cylinder 140 and a cutting device 150 for cutting the molten glass. By lowering the cylinder 140, the molten glass can be formed in the mold 130.

[0031] The conveyor 400 has a plurality of tables 410 on which the main container body 12 and the glass container 10 can be placed. These tables 410 are arranged adjacent to one another in a loop, and each table 410 is designed to rotate in a predetermined direction. Furthermore, the plurality of tables 410, arranged in a loop, are rotated by a drive device (not shown) in a direction indicated by symbol A (counterclockwise). Fig. 1) continuously moving.

[0032] A transfer device 160 for transferring the container main body 12 from the molding device 100 to the conveying device 400 is provided between the molding device 100 and the conveying device 400. The transfer device 160 has a gripper 162. By moving the gripper 162, it is possible to transfer the container main body 12 while holding it.

[0033] The heating device 200 is positioned so that the main body of the container 12 can be heated on the table 410. In this example, the heating device 200 has a plurality of burners 210 arranged along the direction of heat transfer of the main body of the container 12. Since the main body of the container 12 is rotated by the rotation of the table 410, the flame of the heating device 200 is radiated evenly onto the outer surface of the main body of the container 12.

[0034] The coating film formation device 300 is located adjacent to the heating device 200. The interior of the coating film formation device 300 is maintained at a predetermined temperature and has a device for supplying the starting material gas (not shown). In the coating film formation device 300, the starting gas is supplied in the direction of at least the outer surface of the main body of the container 12.

[0035] The gradual cooling device 500 includes a means for gradual cooling using gas or electric heating (not shown). A first conveyor belt 510 and a second conveyor belt 520 are provided between the conveying device 400 and the gradual cooling device 500. A transfer device 430 for transferring the glass containers 10, on which the coating film has been formed, from the conveying device 400 to the first conveyor belt 510 is provided between the conveying device 400 and the first conveyor belt 510. The transfer device 430 has a gripper 432. By moving the gripper 432, the glass container 10 can be transferred, being held by the gripper. The glass container 10 placed on the first conveyor belt 510 can be moved onto the second conveyor belt 520 by a slide 540. 1.2. Manufacturing process

[0036] In the method for manufacturing a glass container according to one embodiment of the invention, the glass container 10 can be produced using the manufacturing apparatus described above. The manufacturing method according to the present embodiment comprises a first step in which the glass container body 12 is formed, a second step in which heat treatment is carried out while the container body 12 is held at a temperature of 580 °C or higher to desorb sodium from a surface region of the container body 12, and a third step in which a coating film of tin oxide or titanium oxide with a film thickness in the range of 40 nm to 50 nm is formed on the surface of the container body.

[0037] More precisely, in the first step the main container body 12 is formed using the forming device 100. The forming device is not limited to the forming device 100 described above, and a known glass forming machine can be used.

[0038] In the second step, the main body of the container 12 is transferred by the transfer device 160 to the table 410 of the conveying device 400. The movement of the table 410 transfers the main body of the container 12 to the heating device 200. There, the main body of the container 12 is heat-treated while the temperature is maintained at 580 °C or higher, preferably at 600 °C to 770 °C. Furthermore, since the burner is used as the heating device 200 in the present embodiment, flame treatment by oxygen combustion can be employed. By using oxygen combustion in the burner, it is possible to heat the desired surface of the main body of the container 12 to a high temperature in a short time. In this case, the flame temperature is preferably in the range of 1250 °C to 1600 °C, more preferably in the range of 1290 °C to 1580 °C.The contact time between the flame and the main body of the container 12 is preferably in the range of 0.5 s to 2 s, more preferably in the range of 0.8 s to 2 s.

[0039] In the second step, as described above, the temperature of the main container body 12 is maintained within a predetermined range, and the main container body 12 is heated under predetermined conditions by flame treatment. This allows the sodium in the surface area of ​​the glass of the main container body 12 to be desorbed and its concentration to be reduced. As a result, a glass container with excellent alkali resistance and scratch resistance can be produced. The reason for this is explained in detail below.

[0040] In the third step, the main body of the container 12 is transferred by the conveying device 400 into the coating film formation device 300, and a coating film of tin oxide or titanium oxide with a film thickness in the range of 40 nm to 50 nm is formed on the surface of the main body of the container 12. These coating films are formed, for example, by a known hot-end coating process. For example, the following starting materials and the following coating film formation process can be used as a manufacturing method for the coating film.

[0041] The starting materials for the coating film are not subject to any special restrictions, as long as their thermal decomposition and / or hydrolysis can form tin oxide or titanium oxide.

[0042] For example, tin tetrachloride, monobutyltin trichloride, dimethyltin dichloride, or the like can be used as the compound for tin, and titanium tetrachloride and the like can be used as the compound for titanium. Other metal compounds can also be added within the scope of the invention. The coating film formation process is not subject to any particular restrictions as long as a coating film is formed by bringing the starting material gas into contact with the surface of the main body of the container 12, which has been set to a desired temperature range. An example of the coating film formation process can be a chemical vapor deposition process.

[0043] The film formation conditions preferably include a temperature of the starting material gas of 130 °C to 150 °C and a treatment time that depends on the temperature of the starting material gas and the film thickness, but preferably 2 s to 4 s.

[0044] Furthermore, the starting material gas can be supplied depending on the formation area of ​​the coating film. For example, if it is desired to form a coating film on the side surface of the Fig. To form the 2 shown glass container (beer mug), the starting material gas is blown onto the outer surface of the container main body 12, and a gas that does not contain starting material gas is supplied to the interior of the container main body 12. 2. Glass container

[0045] Fig. Figure 2 is a detailed view that schematically depicts the glass container 10 according to the present embodiment. In the Fig.In example 2, the glass container 10 is a beer mug, but the glass container 10 is of course not limited to the beer mug.

[0046] How Fig. As shown in Figure 2, the glass container 10 has a main body 12 made of glass and a coating film 14 formed on the surface of the main body 12. The coating film 14 is made of tin oxide or titanium oxide. The film thickness of the coating film 14 is in the range of 40 nm to 50 nm, and in the depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, the atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less.

[0047] The main body of the container 12 is made of glass and the glass is not subject to any special restrictions and can be soda-lime glass or the like.

[0048] The coating film 14 is described below. The coating film 14 is made of tin oxide or titanium oxide, and its film thickness is in the range of 40 nm to 50 nm. If the film thickness of the coating film 14 is within this range, no rainbow coloration occurs, and the aesthetic appearance of the glass container 10 is not impaired, while adequate alkali resistance and scratch resistance are ensured. The coating film 14 can be formed on the entire surface of the main container body 12, preferably with the exception of the bottom surface, but it can also be formed on a portion of the surface of the main container body 12, in particular at least on the outer surface of the main container body 12.By forming the coating film 14 accordingly, at least on the outer surface of the main container body 12, it is possible to effectively prevent the occurrence of scratches caused by contact between the glass containers 10.

[0049] Furthermore, in the depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis of the glass container 10, the atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less.

[0050] In particular, as in Fig. 3 shown, in the depth profile obtained by carrying out the XPS analysis using the sample from the glass container 10, the atomic percentage (atom %) of profile c of sodium at point X where profile a of tin Sn and profile b of silicon Si intersect is 2% or less, preferably 1% or less.

[0051] Fig.Figure 4 shows the depth profile obtained by performing the XPS analysis on a comparative example. How Fig. Figure 4 shows that in the comparative example, the atomic percentage (atom %) of profile c of sodium at point X, where profile a of tin (Sn) and profile b of silicon (Si) intersect, is greater than 2%. The values ​​shown in the Fig. 3 and Fig. The data illustrated in section 4 will be explained in detail in the following examples.

[0052] By reducing the sodium concentration in the surface area of ​​the glass container 10 below its specific value, it is possible to minimize the adverse effects of sodium salt caused by the reaction of sodium with chlorine or the like as the starting material for the coating film 14. As a result, the coating film 14 is dense, has high strength, and is free of pinhole pores caused by the sodium salt.

[0053] More precisely, as described below, a large number of pinhole pores are formed in the oxide coating film produced by the conventional process. Alkaline cleaning solutions penetrate these pinhole pores, causing erosion and enlargement, and eventually leading to the detachment of the coating film. This results in light scattering and bleaching of the glass surface. It is assumed that the pinhole pores are caused by the reaction of sodium in the glass surface area with chlorine contained in the tin oxide or titanium oxide starting material. This reaction produces sodium chloride crystals, which then detach from the coating film.

[0054] According to the invention, the formation of sodium chloride, which causes pinprick pores, can be reduced because sodium can be removed from the surface area of ​​the glass or its quantity can be greatly reduced. As a result, the glass container 10 according to the invention has the following physical properties. (1) Surface hardness

[0055] The coating film 14 has a surface hardness in the range of 7000 N / mm². 2 up to 8500 N / mm 2 , determined by an extremely low stress hardness test in accordance with JIS Z 2255:2003.

[0056] The measurement conditions for surface hardness are explained in detail in the examples. (2) Surface roughness

[0057] The coating film 14 has a surface roughness of preferably 15 nm or less, measured by an atomic force microscope (AFM). The measurement conditions for the surface roughness are explained in detail in the examples. (3) Scratch resistance

[0058] The coating film 14 has a scratch resistance of preferably 8 kg or more, more preferably 9 kg or more. The measurement conditions for the scratch resistance are explained in detail in the examples. If the scratch resistance is within this range, scratching of the surface of the glass container 10 is less likely, and the scratch resistance is excellent. The scratch resistance is strongly influenced by the surface hardness and surface roughness of the coating film 14, and it is important that the scratch resistance is within the aforementioned range. 3. Examples

[0059] Examples of the invention and comparative examples are described below, whereby the invention is not limited to the examples. 3.1. Heat treatment conditions in the second step of the manufacturing process

[0060] To ensure suitable conditions for heat treatment in the second step according to the manufacturing process of the invention, tests were first carried out regarding the relationship between the temperature of the container main body and the heat treatment conditions. (1) Preparation of the sample

[0061] As a test, a sample was prepared in the following manner using the in Fig. 1 shown in the manufacturing device, 1000 formed glass containers are used.

[0062] A container body (a cylinder for a beer mug) was formed using a forming device 100 and soda-lime glass. Subsequently, heat treatment was carried out using an oxygen flame via a heating device (burner 210) while the container body was held at a predetermined temperature, and sodium was desorbed from the outer surface of the container body. A tin oxide coating film with a film thickness of 40 nm was then formed on the outer surface of the container body using the coating film forming device 300 at a starting material gas temperature of 130 °C and a film formation time of 2 s.

[0063] The samples for Examples 1 to 9 and Comparison Examples 1 to 10 were created by varying the flame temperature, flame treatment time, and the temperature of the main container body. The flame temperature, flame treatment time, and main container body temperature of the samples are shown in Table 1, along with the results regarding the resistance to cleaning in a dishwasher, as described below. Fig. 5 and Fig. Figure 6 also shows the results regarding flame temperature, flame treatment time and resistance to cleaning in a dishwasher.

[0064] Furthermore, samples from Comparison Examples 11 and 12 were prepared as comparison examples without flame treatment. More precisely, in Comparison Example 11, a sample was prepared in the same manner as in Example 1, except that the flame treatment was not performed and the coating film thickness was set to 12.5 nm. In Comparison Example 12, a sample was prepared in the same manner as in Example 1, except that the flame treatment was not performed and the coating film thickness was set to 80 nm. It should be noted that Comparison Example 12 corresponds to the method for producing a coating film described in PTL 1. TABLE 1 Flame temperature (°C) Flame treatment time (s) Container main body temperature (°C) Coating film thickness (nm) Dishwasher resistant Examples 1 1580 1 600 40 ◯ 2 1420 1 600 40 ◯ 3 1390 1 630 40 ◯ 4 1290 1,5 600 40 ◯ 5 1580 0,5 600 40 Δ 6 1300 1 600 40 Δ 7 1290 1 600 40 Δ 8 1390 1 580 40 Δ 9 1460 1 580 40 Δ Comparative examples 1 1420 0,5 600 40 X 2 1390 0,7 600 40 X 3 1390 0,5 600 40 X 4 1300 0,5 600 40 X 5 1290 0,5 600 40 X 6 1350 2 500 40 X 7 1390 1 500 40 X 8 1390 1 550 40 X 9 1420 0,5 550 40 X 10 1460 1 550 40 X 11 - - 580 12,5 X 12 - - 580 80 X (2) Testing procedures

[0065] Alkali resistance and resistance to washing in a dishwasher (resistance to repeated washing in a dishwasher) were investigated by the following methods. a. Alkali resistance

[0066] Each sample was immersed in a 0.1% sodium hydroxide solution at 65 °C for 2 hours, and then the bleaching state of the sample was observed. The evaluation was carried out as follows. Good: no fading was observed. Sufficiently good: slight fading was observed. Deficient: significant fading was detected. b. Resistance to cleaning in the dishwasher

[0067] Each sample was washed 3000 times in a commercial dishwasher, and the condition of the glass containers was observed. The evaluation was carried out as follows. The results are shown in Table 1 and the Fig. 5 and Fig.6 shown. In Table 1 and the Fig. 5 and Fig. 6 denotes “O” “good”, “Δ” “sufficiently good” and “X” “deficient”. Good: no fading was observed. Sufficiently good: slight fading was observed and the transparency of the glass container was slightly reduced. Defective: significant fading or rainbow effect was detected. (3) Test results a. Alkali resistance

[0068] The samples according to examples 1 to 4 all achieved a "good" result and no fading was observed. The samples according to examples 5 to 9 all achieved a "sufficiently good" result and the transparency of the samples was slightly reduced.

[0069] In contrast, the samples in comparison examples 1 to 11 all received a "deficient" rating, and fading was observed. No fading was observed in the sample of comparison example 12 because the coating film was thick. b. Resistance to cleaning in the dishwasher

[0070] As in the Fig. 5 and Fig. As shown in Figure 6 and Table 1, the samples according to Examples 1 to 4 all achieved a "good" result, and no fading was observed even after 3000 wash cycles. The samples according to Examples 5 to 9 all achieved a "sufficiently good" result, and the transparency of the samples was slightly reduced.

[0071] In contrast, the results for comparison examples 1 to 12 were "unsatisfactory," and fading was observed. In particular, a silver-white rainbow effect was observed in comparison example 12. This is because a rainbow effect was initially detected in the sample of comparison example 12 due to the coating film being 80 nm thick. However, repeated cleaning in a dishwasher created pinhole pores in the surface of the coating film, causing an iridescent reflection of light on the surface and further intensifying the silver-white rainbow effect. c. Conditions of flame treatment

[0072] The Fig. 5 and Fig.Section 6 and Table 1 confirm that, during the step of sodium desorption from the surface area of ​​the vessel body, it is desirable that the heat treatment (flame treatment) be carried out by adjusting the temperature of the vessel body, the flame temperature, and the flame treatment time within suitable ranges. Fig. 5 and Fig. Reference symbols marked “e” are results of examples, and reference symbols marked “c” are results of comparison examples.

[0073] In particular, a correlation between the flame temperature and the flame treatment time can be seen from Table 1 and Fig. 5. If the flame temperature is low, it is desirable to increase the flame treatment time, whereas if the flame temperature is high, a reduction in the flame treatment time is desirable. As shown in Table 1 and Fig.As shown in Figure 6, it was further confirmed that if the temperature of the main container body is lower than 580 °C, good resistance when washing in a dishwasher cannot be achieved, even if the flame temperature is increased and the flame treatment time is extended.

[0074] From the foregoing, it has been confirmed that during flame treatment, the temperature of the main body of the container is preferably 580 °C or higher, the flame temperature is preferably in the range of 1250 °C to 1600 °C, and the flame treatment time is preferably approximately in the range of 0.5 s to 2 s, more preferably in the range of 0.8 s to 2 s. In Example 5, the "sufficiently good" result was achieved even when the flame treatment time was short because the flame temperature was high. 3.2. XPS analysis (Example 10, Comparative Example 13)(1) Sample preparation

[0075] The main body of the container (cylinder of a beer mug) was formed using the forming device 100 and soda-lime glass. Then, while the main body was held at 700 °C, it underwent heat treatment with an oxygen flame using the heating device (burner 210) at a flame temperature of 1420 °C and a flame treatment time of 1 s to desorb any sodium present on the outer surface of the main body. Subsequently, a tin oxide coating film with a film thickness of 40 nm was formed on the outer surface of the main body using the coating film forming device 300 at a starting material gas temperature of 140 °C and a film formation time of 2 s. A sample of Example 10 was thus obtained.

[0076] A sample of Comparative Example 13 was obtained in the same manner as in Example 10, except that no flame treatment was carried out. In this case, the temperature of the main container body at the time of coating film formation was 580 °C. The manufacturing conditions of Example 10 and Comparative Example 13 are shown in Table 2. Table 2 Flame temperature (°C) Flame treatment time (s) Container main body temperature (°C) Coating film thickness (nm) Example 10 1420 1 700 40 Comparative example 13 - - 580 40 (2) Analytical methods

[0077] Primarily the central portion of the sample from Example 10 was cut out to prepare a square sample piece with a side length of approximately 10 mm. XPS analysis was performed at random points on this sample piece under the following conditions. The sample from Comparative Example 13 was also subjected to XPS analysis under the following test conditions. The results of Example 10 are presented in Fig. 3 is shown and the results of comparison example 13 are in Fig.4 shown.

[0078] Conditions for XPS analysis: Device: K-alpha, manufactured by Thermo Fisher Scientific Inc. Test conditions: Radiation source: Al monochromator Measuring diameter 400 µm ϕ Transmission energy 150 eV Measured elements: Si, Cl, C, Ca, Sn, O, Na Sputtering conditions: Ar monomer ion gun 2 kV / pitch size 2 m, sputtering rate: 1.89 nm / s (3) Analysis result

[0079] As in Fig. As shown in Figure 3, in the depth profile obtained by performing the XPS analysis using the sample from Example 10, the atomic percentage (atom%) of profile c of sodium at point X, where profile a of tin Sn and profile b of silicon Si intersect, was approximately 0.5%.

[0080] In contrast, as in Fig.4 shown in the comparative example 13, the atomic percentage (Atom%) of profile c of sodium at point X, where profile a of tin Sn and profile b of silicon Si intersect, is about 2.5%.

[0081] From the Fig. 3 and Fig.Figure 4 shows that in the sample of Example 10, almost no sodium is present from the surface of the coating film down to a sputtering depth of approximately 40 nm, and the increase in sodium is gradual even at greater sputtering depths. Given that the coating film thickness was 40 nm, it was confirmed that practically no sodium was present in the coating film 40 of the sample from Example 10. In contrast, in the sample of Comparative Example 13, although almost no sodium was present from the surface of the coating film down to a sputtering depth of approximately 35 nm, the amount of sodium increased abruptly at greater sputtering depths. Given that the coating film thickness was 40 nm, it was therefore confirmed that sodium was present in the region of the coating film 40 near the main body 12 of the sample from Comparative Example 13.

[0082] Based on the above results, it was confirmed that in the examples according to the invention, the sodium concentration in the surface area of ​​the glass of the main container body could be sufficiently reduced by flame treatment. 3.3. Surface examination of the coating (Example 10, Comparative Example 13)

[0083] In the samples from Example 10 and Comparative Example 13, the surface of the coating film was examined using an electron microscope. The results are presented in the Fig. 7 and Fig. Figure 8 is shown. The magnification of the microscopic image was 5000 times.

[0084] As in Fig. As shown in Figure 7, the surface of sample 10 was smooth and no pinhole pores were observed. As in Fig.In contrast to the sample shown in Figure 8, a large number of pinhole pores were observed on the surface of the sample in Comparative Example 13. The above results confirm that the surface of the coating film can be produced smooth and without pinhole pores by desorbing sodium present in the surface area of ​​the main container body through heat treatment. 3.4. Surface hardness of the coating (Examples 10 and 11, comparison examples 11, 12 and 14)(1) Sample

[0085] The surface hardness of samples from Example 10 and Example 11 was measured. For Example 11, a sample was prepared in the same manner as for Example 10, except that the film thickness was changed from 40 nm in Example 10 to 48 nm. For comparison, samples from Comparison Examples 11 and 12 and from Comparison Example 14 were used. For Comparison Example 14, a sample was prepared in the same manner as for Example 10, except that the film thickness was changed from 40 nm in Example 10 to 64 nm. (2) Measurement methods

[0086] The surface hardness of each sample was measured by an extremely low-load hardness test according to JIS Z 2255:2003. For the measurement, a square sample with a side length of approximately 10 mm was prepared by cutting it from near the center of the sample container. An indentation hardness test was performed under the following test conditions, using the area around the apex of the curved surface of the sample as the measuring point.

[0087] Device: ENT-1100a ultra-low impact hardness tester, manufactured by ELIONIX Inc. Test conditions: Test load 0.1 mN Imprint condition: 500 steps / step interval 20 ms Test temperature: 25°C ±1°C (3) Measurement results

[0088] The measurement results are given in Table 3. TABLE 3 Example 10 Example 11 Comparative example 11 Comparative example 12 Comparative example 14 Film thickness CTU 100 120 50 200 160 nm 40 48 12,5 80 64 Hardness (N / mm) 2 ) 7062 8256 6798 8964 8886

[0089] Table 3 confirms that the surface hardness increased with increasing film thickness of the coating film. This measurement result confirms that the surface hardness of the embodiment according to the invention should ideally be in the range of approximately 7000 N / mm². 2 up to 8500 N / mm 2 lies. 3.5. Surface roughness of the coating (Examples 9 and 12, Comparative Example 12)(1) Sample

[0090] The surface roughness of the coating film was measured for the samples from Example 9 and Example 12. For Example 12, a sample was prepared by setting the flame temperature during flame treatment to 1420 °C, the flame treatment time to 2 s, and the temperature of the main container body during flame treatment to 720 °C. The sample from Comparative Example 12 was used for comparison. The preparation conditions of the samples from Example 12 and Comparative Example 12 are shown in Table 4. (2) Measurement methods

[0091] The surface roughness of the coating film was measured using an atomic force microscope (AFM) under the following conditions. For the measurement, a square sample with a side length of approximately 10 mm was prepared by cutting it from near the center of the sample glass container. The surface roughness was measured by scanning the unevenness of a 1 µm or 10 µm area on any side of the sample surface. Device: Nanoscope (AFM probe type), manufactured by Digital Instruments Co., Ltd. Test conditions: Sampling rate 1,001 Hz Grid size: 1 µm or 10 µm (3) Measurement results

[0092] The results of Example 12 are in the Fig. 9 and Fig. The results of example 9 are shown in 10; the results of example 9 are in the Fig. 11 and Fig.12 are shown and the results of comparison example 12 are in the Fig. 13 and Fig. Figure 14 shows that the surface roughness (Rms) of the sample from Example 12 was 13.68 nm and the surface roughness (Rms) of the sample from Example 9 was 14.34 nm. This confirmed that as the temperature of the main container body increased during heat treatment, the surface roughness decreased and the crystals of the coating film became smaller.

[0093] Furthermore, in the sample from comparison example 12, although the crystals of the coating film were small, the surface roughness was 17.49 nm due to the creation of pinhole pores. 3.6. Scratch resistance of the glass container(1) Sample

[0094] The samples of Examples 12 to 15 were produced by adjusting the flame treatment conditions, the temperature of the main vessel body during the heating step, and the coating film thickness as shown in Table 4. The samples of Comparative Examples 11 to 13 and 15 were produced without any flame treatment, adjusting the conditions relating to the temperature of the main vessel body and the coating film thickness according to the specifications in Table 4. Comparative Example 16 is an example in which no film was formed. (2) Measurement methods

[0095] How Fig.As shown in Figure 15, a sample A is placed horizontally on a weighing instrument (automatic weighing instrument) and the weight is reset to 0. A sample B is then brought into contact with sample A and rubbed in the direction from the body part to the opening part of sample A, as indicated by arrow X, while a condition is maintained in which sample B is subjected to an arbitrary load from above, as indicated by arrow Z. If no scratches occurred, the same test was repeated, increasing the compressive force by 1 kg, and the load at which a scratch appeared on the surface of sample A was determined. (3) Measurement results

[0096] The measurement results are shown in Table 4 and the Fig. 16 and Fig. 17 shown. Fig. Figure 16 illustrates the relationship between the film thickness of the coating film and the scratch generation load and Fig.Figure 17 shows the relationship between the temperature of the main container body during heat treatment and the scratch-generating load. In the Fig. 16 and Fig. 17 Reference symbols marked with “e” are results of examples and reference symbols marked with “c” are results of comparison examples. TABLE 4 Flame treatment conditions Container main body temperature (°C) Coating film thickness (nm) Scratch resistance (kg) Flame temperature (°C) Flame treatment time (s) ctu nm Examples 12 1420 2s 720 100 40 11 13 1420 1 s 680 100 40 9 14 1420 1 s 680 120 48 10 15 1420 2s 720 120 48 12 Comparative examples 11 - - 580 50 12,5 3 12 - - 580 200 80 7 13 - - 580 100 40 6 15 - - 580 120 48 7 16 - - 580 0 0 0,5

[0097] As shown in Table 4 and in the Fig. 16 and Fig.As shown in Figure 17, it has been confirmed that the scratch resistance of the samples in Examples 12 to 15 increased with increasing film thickness. This trend is also the same for the comparison examples that were not subjected to flame treatment; however, the results of the samples in Comparison Examples 13 and 15 confirm that these samples did not have sufficient scratch resistance. In the case of Comparison Example 11, where the coating film thickness was too small, the scratch resistance was significantly low, whereas in Comparison Example 12, it was confirmed that sufficient scratch resistance could not be achieved despite a relatively large coating film thickness.

[0098] Furthermore, there is a correlation between the temperature of the main container body during flame treatment and the scratch resistance, as shown in Table 4 and Fig.17 shown. In the samples of examples 12 to 15, it was confirmed that the scratch resistance increases with higher temperature of the main container body. 3.7. Summary

[0099] As described above, according to the examples of the invention, very good results with regard to alkali resistance, smoothness of the coating film surface, surface hardness, surface roughness, and scratch resistance could be achieved by removing sodium from the surface area of ​​the main container body or by reducing the amount of sodium. As a result, the glass container according to the invention has excellent scratch resistance, alkali resistance, resistance to cleaning in a dishwasher and the like, shows no rainbow effect, and has an excellent aesthetic appearance.

[0100] The invention is not limited to the embodiments described above, and various modifications are possible. For example, the invention includes various other configurations that are essentially identical to those described in the embodiments (for example, configurations that have identical functions, methods, and results, or configurations that have identical objectives and effects). The invention further includes various other configurations in which non-essential elements described in the embodiments are replaced by other elements. The invention also includes various other configurations that have the same effects as those described in the embodiments, or various other configurations that are capable of achieving the same objectives as those described in the embodiments.Furthermore, the invention includes various other configurations in which known techniques are added to the configurations described in the embodiments. LIST OF REFERENCE SYMBOLS

[0101] 10: Glass container, 12: Container main body, 14: Coating film, 100: Molding device, 200: Heating device, 210: Burner, 300: Coating film forming device, 400: Conveying device, 410: Table, 500: Curing device

Claims

[1] Glass container (10) containing: a container main body (12) made of glass; and a coating film formed on a surface of the container main body (12) made of tin oxide or titanium oxide, wherein the coating film has a film thickness in the range of 40 nm to 50 nm and a scratch resistance of 8 kg or more, and in a depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, an atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less, where the scratch resistance of the coating film is measured by: Placing a sample A horizontally on a weighing instrument; Touching a sample B with sample A; Rubbing the sample B in the direction from a body part to an opening part of the sample A while maintaining a state in which the sample B is subjected to an arbitrary load from above; if no scratch appears on the surface of sample A, repeat the rubbing, increasing the pressure force by 1 kg; Determine a load at which a scratch occurs on the surface of sample A. [2] Glass container (10) according to claim 1, wherein the coating film has a surface hardness in the range of 7000 N / mm 2 up to 8500 N / mm 2 determined by an extremely low stress hardness test in accordance with JIS Z 2255:2003. [3] The glass container (10) according to claim 1 or 2, wherein the coating film has a surface roughness (RMS) of 15 nm or less as measured by an atomic force microscope (AFM). [4] The glass container (10) according to any one of claims 1 to 3, wherein the coating film is formed on at least one outer surface of the container main body (12). [5] Glass container (10) according to one of claims 1 to 4, wherein the glass container (10) is a jug, a pitcher, a bowl, a bowl, a stemmed glass (glass with a foot), a beer mug or a bottle. [6] A method for producing a glass container (10) comprising: a first step in which a container main body (12) made of glass is formed; a second step in which a heat treatment is carried out while maintaining the container main body (12) at a temperature of 580 °C or higher to desorb sodium in a surface region of the container main body (12), wherein the heat treatment in the second step is a flame treatment in which the flame temperature is in the range of 1250°C to 1600°C and the flame contact time is in the range of 0.5 s to 2 s; and a third step in which a coating film of tin oxide or titanium oxide having a film thickness in the range of 40 nm to 50 nm is formed on a surface of the container main body (12). [7] The method according to claim 6, wherein the temperature of the container main body (12) in the second step is in the range of 600 °C to 770 °C. [8] A method according to claim 6 or 7, wherein in the flame treatment the flame temperature is in the range of 1290°C to 1580°C and the flame contact time is in the range of 0.8 s to 2 s.

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