JP2007246295A - Method and apparatus for manufacturing glass plate with functional thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass plate with a functional thin film, wherein an efficient drying process is realized. <P>SOLUTION: The method for manufacturing the glass plate with a functional thin film includes a coating process for forming a liquid film on the surface of a glass plate by coating the surface of the glass plate with a liquid functional coating agent and a heating process for firing the liquid film by heating the glass plate having the liquid film formed thereon. Further, the method has a drying process for drying the coated liquid functional coating agent between the coating process and the heating process. The drying process includes a vacuum drying process and an air-blast drying process following the vacuum drying process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a glass plate with a functional thin film and a manufacturing apparatus for efficiently forming a liquid functional coating agent on the surface of the glass plate.

  In recent years, a glass plate with a functional thin film having a heat insulating function or the like is being used in the field of automotive glass. As a method of forming this type of functional thin film on a glass plate, there are a method of spraying a thin film forming liquid, a dip coating method, a spin coating method, a roll coating method and the like. However, in these methods, when a thin film is formed on the surface of a large glass plate such as a decorative window glass for a building or a window glass of an automobile, the amount of the chemical solution for forming the thin film is small. Due to the mechanism, a large amount of chemical solution is required and a chemical solution fee is required.

  Furthermore, vacuum deposition, electron beam method, CVD method (chemical vapor deposition method), plasma CVD method, plasma jet spraying method, sputtering method, etc. attach a thin film with a uniform film thickness to the glass plate surface in vacuum. For example, when manufacturing a liquid crystal display, a metal thin film such as a Cr light-shielding film or an ITO conductive film is formed on the surface of the glass substrate using a sputtering method. However, in these methods, when a thin film is formed on the surface of a large glass plate such as a decorative window glass for a building or a window glass of an automobile, the film must be formed in a vacuum, and is formed by a vacuum apparatus. The equipment is large and expensive.

  There is a screen printing method as a method that does not require a large amount of chemical solution to form a thin film on the surface of a large glass plate and does not use an expensive vacuum film forming apparatus. Screen printing requires a high-viscosity chemical. To increase the viscosity of the chemical, high molecular weight organic substances are usually used. However, if a large amount of high molecular weight organic substances is used, a thin film formed on the glass plate surface. Affects chemical resistance and wear resistance.

  Further, there is a flexographic printing method as a method capable of forming a thin film on the surface of a large glass plate with high productivity, that is, at a high speed and controlling the film thickness of the thin film with high accuracy and good reproducibility. However, in the flexographic printing method, unevenness is likely to occur due to direct contact with the plate.

Therefore, as a method of forming this type of functional thin film,
Conventionally, in a manufacturing process of a color filter of a liquid crystal display, as a coating method for forming a coating film by coating a coating liquid on the surface of a glass substrate, a coating liquid discharging die head having a slit-shaped discharge port has been used. With the coating liquid discharged from the outlet in the form of a curtain, the surface of the glass substrate is moved relative to the glass substrate in a direction perpendicular to the slit direction of the discharge port to apply the coating liquid over the entire surface of the glass substrate. There is known a slit coating method for applying a coating (for example, see Patent Document 1). This is advantageous in that the slit coating method can form a uniform thin film even on a relatively large glass plate, and the problem in the spin coating method that the coating agent is scattered around is eliminated. This is because there is an advantage.

Further, as an application method for performing the two-layer coating, an application method in which the first-layer coating agent is heated and cooled prior to the application of the second-layer coating agent is known (for example, Patent Document 2). 3).
Japanese Patent Application Laid-Open No. 2002-153795 Japanese Patent Laid-Open No. 9-176527 Japanese Patent Laid-Open No. 8-41441

  However, the slit coating method is a method of coating while discharging the coating agent through the slit, so that the coating agent is easily fixed to the slit and does not hinder the coating, There is a restriction that materials that are difficult to dry must be used. For this reason, when the slit coating method is adopted, it is necessary to lengthen the drying time in the vacuum drying process subsequent to the coating process, or another heating and cooling process is required subsequent to the vacuum drying process, and the tact time is reduced. There arises a problem that deterioration and an increase in equipment cost are caused. On the other hand, if the drying time in the vacuum drying step is insufficient, there is a problem that the film quality is uneven when the glass plate is heated in the next step, or insufficient drying when performing two-layer coating. As a result, the problem arises that the solvent of the coating agent remaining without being removed reacts with another coating agent applied in the next step.

  Then, an object of this invention is to provide the manufacturing method and manufacturing apparatus of a glass plate with a functional thin film which can be applied also to the structure which uses a slit coat method, and can implement | achieve the efficient drying process.

In order to solve the above object, the first invention is to apply a liquid functional coating agent on the surface of a glass plate to form a liquid film on the surface of the glass plate, and to the glass plate on which the liquid film is formed. And a heating step of firing the liquid film, and a method for producing a glass plate with a functional thin film,
Between the application step and the heating step, the step of drying the applied liquid functional coating agent,
The drying process includes a vacuum drying process and a blow drying process subsequent to the vacuum drying process.

  According to a second invention, in the method for producing a glass plate with a functional thin film according to the first invention, a plurality of glass plates that have undergone the vacuum drying step are blown and dried simultaneously in the blow drying step. .

A third invention is characterized in that, in the method for producing a glass sheet with a functional thin film according to the first or second invention, a material that satisfies the following conditions is used as the functional coating agent.
[Conditions] In an atmosphere of a temperature of 21 ° C. and a humidity of 30%, the time taken to drop 0.05 g on the glass plate and fix it is 7 minutes or more.

  4th invention is a manufacturing method of the glass plate with a functional thin film which concerns on any one of 1st-3rd invention, The said application | coating process is a glass plate, discharging a functional coating agent from a slit on the surface of a glass plate. On the other hand, it is implemented by a slit coat method in which the position of the slit is moved.

  According to a fifth invention, in the method for producing a glass sheet with a functional thin film according to the fourth invention, a material having a viscosity of 0.1 to 10 centipoise is used as the functional coating agent.

  6th invention is the manufacturing method of the glass plate with a functional thin film which concerns on any 1st-5th invention, 2nd which apply | coats a 2nd functional coating agent between the said drying process and the said heating process. It has an application | coating process and the 2nd drying process which dries the apply | coated 2nd functional coating agent, It is characterized by the above-mentioned.

  7th invention is a manufacturing method of the glass plate with a functional thin film which concerns on any one of 1st-6th invention, The said ventilation drying process is performed by the breeze with a wind speed of 0.1-1.0 mm / sec. And

The eighth invention is a coating apparatus for applying a functional functional coating agent on the surface of a glass plate and forming a liquid film on the surface of the glass plate;
A drying device for drying the liquid functional coating agent applied by the coating device;
A heating device that heats the glass plate from which the functional coating agent has been dried by the drying device, and bakes the liquid film,
The drying apparatus includes a vacuum drying apparatus and a blow drying apparatus that blows and drys the functional coating agent vacuum-dried by the vacuum drying apparatus.

  According to 1st invention, the functional coating agent apply | coated on the surface of the glass plate by the application | coating process can be efficiently dried by performing vacuum drying and subsequent ventilation drying.

  According to 2nd invention, the deterioration of the tact time by addition of a ventilation drying process can be prevented by carrying out air drying of the glass plate vacuum-dried several sheets simultaneously.

  According to the third invention, a material that is difficult to dry can be used as the functional coating agent by introducing the efficient air drying process according to the first invention or the like.

  According to the fourth invention, the coating by the slit coat method can be performed by introducing the efficient blow drying process according to the first invention or the like.

  According to the fifth invention, a homogeneous liquid film can be easily generated on the surface of the glass plate by using a viscous material suitable for coating by the slit coating method.

  According to the sixth invention, sufficient drying can be realized by introducing the efficient blow drying process according to the first invention or the like, so even if two-layer coating is performed, the first The reaction between the coating agent and the second coating agent can be prevented.

  According to the seventh invention, the air drying process can be carried out under appropriate air blowing conditions, and it is possible to achieve both efficient drying and prevention of deterioration of film quality due to strong wind.

  According to the eighth invention, similarly to the first invention, the functional coating agent applied on the surface of the glass plate in the coating process can be efficiently dried by performing vacuum drying and subsequent blow drying. it can.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, with reference to FIG.1 and FIG.2, the main manufacturing processes (and apparatus used therewith) relevant to the manufacturing method of the glass plate with a functional thin film concerning this invention are demonstrated.

  FIG. 1 is a view showing each device installed on a production line for a glass sheet with a functional thin film according to the present invention along the flow of the production process. FIG. 2 is a diagram showing a configuration of a thin film on a glass plate formed by the manufacturing process of FIG. In the following description, the manufacturing process of glass for automobiles will be described as an example, and the functional thin film formed on the glass plate is assumed to be a thin film having a heat insulating function. That is, below, the manufacturing process of the glass for motor vehicles provided with the functional thin film which absorbs a heat ray is demonstrated to an example.

  1, a flat glass plate having a predetermined size (for example, 1000 mm × 1200 mm) is conveyed, lifted by a loader 100, and conveyed to a predetermined position of the head coater 200. The detailed configuration of the head coaters 200 and 500 will be described later. The process from the loader 100 (head coater 200) to the heating device 700 described later is executed in a clean room in order to prevent dust and the like from entering each liquid film formed on the surface of the glass plate. .

  The head coater 200 forms a liquid film on the surface of the glass plate for forming a first-layer coating F1 (see FIG. 2) by a slit coating method described later. This liquid film is fired in a later step to be described later, and becomes a first layer film that imparts a heat insulating function to the glass plate. The first layer coating may be formed using transparent conductive oxide fine particles that exhibit infrared shielding properties. The transparent conductive oxide fine particles are preferably fine particles comprising at least one selected from the group consisting of indium oxide, tin oxide, and zinc oxide. From the viewpoint of infrared shielding properties, fine particles made of a material in which tin oxide is mixed with indium oxide (hereinafter referred to as ITO) are preferable. When the ratio of the tin oxide and indium oxide mixture of ITO is expressed by the number of tin atoms to the number of indium atoms (Sn / In), it is necessary that Sn / In = 2 to 20, particularly Sn / In = 3 to 10 preferable.

  Suitable ITO fine particles used here have a c light source in the xy chromaticity coordinates, a powder color in a 2 ° field of view having an x value of 0.3 or more and a y value of 0.33 or more. Such ITO fine particles themselves do not have infrared shielding properties, but reduction occurs in the film in a subsequent baking step, and carriers are generated to form a film having infrared shielding properties. Such ITO fine particles can be prepared only by firing a precursor powder obtained by a coprecipitation method or the like in the air or in a normal inert gas such as nitrogen.

  The ITO fine particles are required to have an average primary particle diameter of 100 nm or less from the viewpoint of transparency. It is particularly preferable to use ITO fine particles having a crystallite diameter calculated from powder X-ray diffraction analysis of 15 to 50 nm. If the crystallite size is smaller than this, high infrared shielding properties cannot be expressed even after reduction in the film, and transparency may be lowered with fine particles having a crystallite size larger than this. It is.

  The aggregated state of ITO fine particles in the coating after firing reflects the aggregated state in the composition. To maintain the transparency and radio wave transmission of the coating, the ITO fine particles are highly dispersed in the composition. Need to be. The dispersion state is preferably 500 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less as the number average aggregate particle diameter. As the dispersion medium, various solvents such as polar solvents such as water and alcohol, and nonpolar solvents such as toluene and xylene can be appropriately used. As a method for dispersing, a known method can be used, and a media mill such as ultrasonic irradiation, a homogenizer, a ball mill, a bead mill, a sand mill, and a paint shaker, or a high-pressure impact mill such as a jet mill or a nanomizer can be used.

A composition for coating (for first layer coating) by adding a component (hereinafter referred to as a siloxane matrix material) that can be converted into a silicon oxide matrix having a siloxane bond by heating to a dispersion in which ITO fine particles are dispersed in a solvent as described above. Liquid coating agent). A siloxane matrix material is a compound that can form a hard, transparent silicon oxide matrix by forming a siloxane bond (Si-O-Si) by heating to form a three-dimensional network. Specifically, it is an alkoxy used in the sol-gel method. Examples include hydrolysis of silanes and alkoxysilanes, condensates of alkoxysilanes, and water glass. Of these, alkoxysilanes are preferably used. Examples of the alkoxysilanes include alkoxysilanes represented by the general formula (CH ₃ ) _a Si (OR) _4-a (R is a methyl group or an ethyl group, and a is an integer). Tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and a mixture thereof, a hydrolyzate of the mixture, or a polycondensate of the mixture One or more types selected from are preferred.

In order to provide the first layer coating with an effective infrared shielding property, a certain amount of thickness is required. Therefore, considering the balance between the thickness and the hardness of the coating, the mixture, the hydrolysis, or the polycondensate having an average composition formula 1 or more kinds selected from the group consisting of is represented by _{(CH 3) m Si (oR} ) 4-m (m = 0.2~0.95) is more preferable. Here, m represents the abundance ratio of CH ₃ groups adjacent to Si atoms and Si atoms. When m is less than 0.2, the film tends to crack when the film is thickened, and exceeds 0.95. Then, not only is it difficult to form a film having sufficient hardness, but the CH ₃ group is difficult to be removed during the heat treatment described later, and the film may be colored. Further, Ti, Sn, Zr, Al, B, P, Nb, Ta, or other elements that can be glass forming or modifying components or compounds thereof may be included.

  The abundance ratio between the ITO fine particles and the siloxane matrix material in the composition is [ITO fine particles] / [silicon oxide] = 1/2 or more in terms of mass ratio in terms of oxide. Preferably it is 1/1 or more. This is because if the ITO fine particles are less than 1/2 in mass ratio with respect to the siloxane matrix material, the infrared shielding property is insufficient.

The vacuum dryer 300 includes a chamber for performing vacuum drying, and the glass plates coated with the liquid film by the head coater 200 as described above are accommodated one by one in the chamber. When the glass plate is accommodated in the chamber, the pressure in the chamber is reduced, and the solvent contained in the liquid film applied by the head coater 200 is removed. Thereby, the coating agent of the 1st layer adheres in a layer form on the surface of a glass plate. This vacuum drying step is performed on a single glass plate over a predetermined vacuum drying time, for example, under a reduced pressure condition of −1.33 × 10 ² [Pa]. The predetermined vacuum drying time is determined according to the tact time. Therefore, it is desirable that the vacuum drying time is short from the viewpoint of shortening the tact time. In this example, it is 10 minutes.

  The blast drying apparatus 400 performs blast drying by supplying fine wind to the glass plate that has undergone the vacuum drying process by the vacuum dryer 300. A detailed configuration of the blower drying apparatus 400 will be described later.

  This blow drying process is preferably a first-in first-out (FIFO) batch process. For example, the blower drying apparatus 400 stores a plurality of glass plates that are sequentially supplied from the vacuum dryer 300 every 10 minutes, performs simultaneous blown drying, and blown and dried, for example, 20 minutes for one glass plate. Later, it may be paid out to a subsequent process. In this case, the vacuum drying time is 10 minutes + the blast drying time is 20 minutes = the total drying time is 30 minutes, and a drying process sufficient to completely remove the solvent contained in the liquid film is realized for one glass plate. be able to. Also in this case, the blower drying process is a first-in first-out batch process, and the glass plate that has been subjected to the 20 minute blown drying process can be dispensed from the blower drying apparatus 400 every 10 minutes to the subsequent process. The addition of the process does not hinder the shortening of the tact time.

  The head coater 500 forms a liquid film on the surface of the glass plate that has been subjected to the above-described air-drying process, for forming a second-layer coating F2 (see FIG. 2) by a slit coating method described later. This liquid film is baked in a later step, which will be described later, to become an upper layer film F2 that imparts abrasion resistance to the glass plate or the first layer film. The upper layer film is formed by applying, for example, a composition containing a polysilazane compound as a liquid coating agent for the upper layer film on the lower layer film of the glass plate that has been blown and dried as described above.

  The upper film has a function as an oxygen barrier film that prevents oxygen from being supplied to the transparent conductive oxide fine particles in the lower layer during the subsequent heat treatment to prevent the transparent conductive oxide fine particles from being oxidized. Polysilazane is a general term for resin compounds having Si-NR-Si (R is a hydrogen or hydrocarbon group) silazane bond, and the Si-NH bond is decomposed by heating or reaction with moisture to form a Si-O-Si network. Is a material that forms

  A perhydropolysilazane having the general formula R = H can form a hard upper layer film. The upper layer film formed from this polysilazane has a relatively high oxygen barrier property and is very suitable as an oxygen barrier layer material used in this step. In the composition for forming the upper layer film, a curing catalyst, a solvent, and an activator are added, and the amount of the polysilazane compound in the composition for forming the upper layer film is desirably 20% or less by mass ratio with respect to the entire composition. . Further, a small amount of impurities such as other metal sources which are not necessary for film formation may be contained.

  It is very important that the film thickness of the upper layer film is 0.02 to 0.2 μm as the film thickness after the heat treatment. Although the optimum film thickness varies depending on the components of the undercoat film, if the film thickness is less than 0.02 μm, the oxygen barrier property is insufficient, and the ITO in the undercoat is oxidized during the heat treatment, and the infrared shielding property is maintained. If the film thickness is increased to more than 0.2 μm, decomposition components generated from the lower layer coating during heat treatment, such as organic components generated from the alkoxysilane compound, are difficult to escape, and the coating may be colored or cracked. May occur.

  The vacuum dryer 600 includes a chamber for performing vacuum drying, and the glass plates coated with the liquid film by the head coater 500 as described above are accommodated one by one in the chamber. When the glass plate is accommodated in the chamber, the pressure in the chamber is reduced, and the solvent contained in the liquid film applied by the head coater 500 is removed. Thereby, the coating agent of the second layer is fixed in a layer form on the layer formed by the coating agent of the first layer. Similarly, the vacuum drying time in this vacuum drying process is determined according to the flow of the entire manufacturing process.

  The heating device 700 is made of, for example, an IR heater, and heat-drys the glass plate that has been subjected to the vacuum drying process by the vacuum dryer 600. Thereby, the solvent contained in the liquid film applied by the head coater 500 is completely removed. Since the glass plate that has been subjected to the heat drying process by the heating device 700 is completely dried, it becomes difficult for dust or the like to adhere to the liquid film, so that it can be taken out of the clean room.

  The pre-baking furnace 800 pre-fires the two-layer liquid film formed on the surface of the glass plate as described above. Thereby, the base plate of the glass plate with a heat insulation function thin film is completed. In addition, the base plate of the glass plate with the heat insulating function thin film is processed into a finished product of the glass plate with the heat insulating function thin film having a desired configuration (shape, etc.) through a cutting / chamfering process, a heating / bending molding process, and the like. The In addition, the two-layer liquid film preliminarily fired as described above is completely fired by the heating step before bending. The base plate of the glass plate with a heat insulating function thin film may be processed into, for example, a laminated glass and used as a front windshield of an automobile, or may be processed into a tempered glass and used as a side glass or a rear glass of an automobile. .

  Next, an example of the above-described head coaters 200 and 500 will be described with reference to FIGS. Since the configurations of the head coaters 200 and 500 may be substantially the same, the configuration of the head coater 200 will be described as a representative.

  3 is a cross-sectional view showing a schematic configuration of the head coater 200, FIG. 4 is a top view of the head coater 200 of FIG. 3, and FIG. 5 shows a lower surface (slit 230) of the die head 220 of the head coater 200. FIG. 6 is a diagram schematically showing an application mode by a slit coat method realized by the head coater 200. FIG.

  The head coater 200 includes a die head 220 for discharging a liquid coating agent onto the glass plate G. The die head 220 has a substantially rectangular parallelepiped shape having a length corresponding to the short side of the glass plate G, for example. The glass plate G is disposed on a table below the die head 220 so that the longitudinal direction of the die head 220 (the Y direction in FIGS. 3 and 4) corresponds to the short side direction. On the lower surface of the die head 220, a slit 230 is formed along the longitudinal direction as shown in FIG. The width of the slit 230 (the width in the X direction) is, for example, about 40 microns. The length of the slit 230 in the longitudinal direction (Y direction) is formed slightly shorter than the short side of the glass plate G, for example. A supply pipe 240 communicating with a liquid coating agent supply source (not shown) is connected to the side surface of the die head 220. The die head 220 is configured such that a liquid coating agent is introduced through the supply pipe 240 and the liquid coating agent is discharged from the slit 230 in a curtain shape. The die head 220 is configured to be movable up and down by, for example, an actuator, and is configured to be movable in the X-axis direction (direction perpendicular to the longitudinal direction of the slit 230) along the rail 250 by, for example, an electric motor. ing.

  During operation, the die head 220 moves in the long side direction (X direction in FIGS. 3 and 4) of the glass plate G in a state where the liquid coating agent is discharged in a curtain form from the slit 230, as shown in FIG. Go. In this way, the liquid coating agent is applied to the entire surface of the glass plate G with a uniform predetermined film thickness. The operation of the head coater 200 as described above is controlled by a control device (not shown).

  According to such a slit coating method, a uniform thin film can be formed relatively easily even on a large glass plate G. Also, for example, as in the spin coating method, a coating agent is scattered around and wasted. Maintenance is easy.

  Here, the liquid coating agent used in the slit coating method as described above has an appropriate range of viscosity capable of realizing a curtain-like discharge mode from the film thickness slit 230 (and thus a coating mode with a uniform film thickness). Is desirable. For this reason, the liquid coating agent is preferably a material having a viscosity of 0.1 to 10 centipoise, more preferably a material having a viscosity of 0.8 to 7.0 centipoise.

In addition, the liquid coating agent used in the slit coating method as described above is difficult to dry so that the liquid coating agent does not easily stick to and clog the slit 230 having a small width (for example, a width of about 40 microns). It is desirable to have For this reason, the liquid coating agent is preferably a material that hardly satisfies the following conditions.
[Conditions] In an atmosphere of a temperature of 21 ° C. and a humidity of 30%, the time taken to drop 0.05 g on the glass plate and fix it is 7 minutes or more.

  The above-mentioned liquid coating agent for the first layer coating has been confirmed by the inventors of the present application to satisfy this condition, and has a property that is difficult to dry as a liquid coating agent used in the slit coating method. Yes.

  On the other hand, the above-mentioned liquid coating agent for the upper layer film has been confirmed to satisfy this condition by the inventor of the present application, but has a higher adhesiveness than the liquid coating agent for the first layer film, and therefore clogged the slit. It is easy to induce. For this reason, in the head coater 500, the liquid coating agent for the upper layer coating may be prevented from adhering to the tip of the slit by spraying a solvent, for example, once every 5 minutes.

  By the way, when such a liquid coating agent that is difficult to dry (especially the liquid coating agent for the first layer film) is used, as shown in the section “Problems to be solved by the invention” above, the application process is followed. In the vacuum drying process, it is necessary to lengthen the drying time, or another heating and cooling process is required subsequent to the vacuum drying process, which causes problems such as deterioration in tact time and increase in equipment cost. On the other hand, if the drying time in the vacuum drying process is insufficient, the problem that the solvent of the first layer coating agent remaining without being removed reacts with the second layer coating agent applied in the next step. Will occur.

  On the other hand, according to the present embodiment, as described above, since the blow drying process is performed after the vacuum drying process, the tact time is prevented from being deteriorated as compared with the configuration in which the vacuum drying process is simply lengthened. Compared with a configuration in which separate heating and cooling steps are introduced before the coating agent for the second layer is applied (see, for example, JP-A-9-176527 and JP-A-8-41441). Thus, it is possible to save a large equipment investment for introducing a heating and cooling device and a long waiting time required for heating and cooling the glass plate G. That is, according to the present embodiment, even when a liquid coating agent that is difficult to dry used in the slit coating method is applied, the air drying process is performed subsequent to the vacuum drying process, so that the tact time is deteriorated and the equipment is improved. Necessary drying can be efficiently realized without increasing the cost. Therefore, according to this example, even when a highly reactive material is used as the second layer coating agent as described above, the reaction with the solvent remaining in the first layer coating agent is ensured. Sufficient drying that can be prevented can be achieved efficiently.

  Next, with reference to FIG.7 and FIG.8, one Example of the ventilation drying apparatus 400 suitable for implement | achieving this useful ventilation drying process is described. FIG. 7 is a front view showing a main configuration of the blower drying apparatus 400, and FIG. 8 is a perspective view showing the blower drying chamber 410 in a state where a plurality of glass plates G are accommodated.

  As shown in FIG. 7, the blower drying apparatus 400 includes a drying chamber 410 that houses a plurality of (seven in the illustrated example) glass plates G and a blower 420. As shown in FIG. 8, the drying chamber 410 is formed inside a box-shaped shell box 412, and the shell box 412 has one side surface (the front surface in FIG. 7) for carrying in / out the glass plate G. Is open for. Glass plates G that have undergone a vacuum drying process by the vacuum dryer 300 are sequentially carried into the drying chamber 410 through the opening, for example, by a robot arm. The glass plate G that has been subjected to the blow drying process after a predetermined blow drying time is subjected to the next process (in the above example, the second layer coating process by the head coater 500) from the drying chamber 410 through the opening through the robot arm. ).

  The shell box 412 has a support portion 414 that supports the edge of the glass plate G at every predetermined interval so that the plurality of glass plates G are stacked at a predetermined interval. This predetermined interval may be determined from the viewpoint of workability of carrying in / out the glass sheet G by the robot arm and from the viewpoint of securing an appropriate air flow between the plurality of glass sheets G.

  The shell box 412 is disposed adjacent to the blower 420 so as to efficiently take in the fine wind supplied from the blower 420. A set of side surfaces 412a and 412b of the shell box 412 facing the blower 420 is formed from a member having air permeability. For example, as shown in FIG. 7, a ventilation portion 430 having an air filter function is provided on the side surface 412 a facing the blower 420 in order to introduce the fine wind supplied from the blower 420 into the drying chamber 410. The air filter is preferable because the HEPA filter can remove fine particles with high performance. Although not shown, the other side surface 412b facing the side surface 412a is provided with a similar ventilation portion (however, the air filter function may not be provided) in order to discharge the fine wind introduced into the drying chamber 410. . Accordingly, as shown in FIG. 7, the breeze supplied from the blower 420 is introduced into the drying chamber 410 through the ventilation portion 430 and passes through the space between the plurality of laminated glass plates G to the opposite side. It flows out of the drying chamber 410 through the ventilation part. Due to the flow of the fine wind, the solvent remaining in the coating agent without being completely removed by vacuum drying is completely evaporated and discharged out of the drying chamber 410.

  The present invention is not limited to the above-described configuration in which ventilation is performed from the side surface side of the shell box 412. Instead of or in addition to this configuration, an air filter is provided on the surface facing the loading / unloading opening. You may provide the ventilation part provided with the function. In that case, the fine wind supplied from the blower 420 is introduced into the drying chamber 410 through the ventilation portion, and flows out of the drying chamber 410 through the opening on the opposite side.

  The blower 420 may have any configuration as long as it can supply a breeze, and may be a normal blower such as a fan. The blower 420 preferably generates a breeze with a wind speed of 0.1 to 1.0 mm / sec in the drying chamber 410, and more preferably a breeze with a wind speed of 0.2 to 0.6 mm / sec in the drying chamber 410. Generate. As a result, it is possible to achieve both efficient drying and prevention of liquid film unevenness due to strong wind.

  In addition, the air drying time required for one glass plate is set to a time sufficient for the solvent remaining in the coating agent to be completely removed without being completely removed by vacuum drying. Since the time depends on the wind speed in the drying chamber 410 and the vacuum drying time by the vacuum dryer 300, the time may be adapted to a test or the like.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiments, the method relates to a method of manufacturing a glass plate with a functional thin film formed by two-layer coating, but the present invention is also applicable to the case of forming a functional thin film by one-layer coating. It is.

  As described above, the present invention is not limited to the manufacture of automobile window glass, but can also be applied to the manufacture of window glass for other vehicles, aircraft, ships, buildings, and the like. In addition, the blow drying process according to the present invention is suitable for a drying process after a coating process using an inorganic material coating agent that is difficult to dry, but for a glass substrate for manufacturing a liquid crystal display or a plasma display, for manufacturing a semiconductor integrated circuit. In the drying process after the coating process, various coating liquids are applied to form a coating film such as a photoresist film, an insulating film, or a conductive film on the surface of a substrate such as a silicon wafer or a plastic substrate for manufacturing an optical filter. Is also applicable. Moreover, although the ventilation drying process by this invention is suitable with respect to the drying process after the application | coating process by a slit coat method as mentioned above, it can also be used for the drying process after the application | coating process by a spin coat method.

It is a figure which shows the flow of the glass plate manufacturing process which concerns on the manufacturing method of the glass plate with a functional thin film by this invention. It is a figure which shows the structure of a thin film on the glass plate formed by the manufacturing process of FIG. 2 is a cross-sectional view showing a schematic configuration of a head coater 200. FIG. 2 is a top view of the head coater 200. FIG. 2 is a perspective view showing a lower surface of a die head 220 of the head coater 200. FIG. It is a figure which shows typically the application | coating aspect by the slit coat method implement | achieved by the head coater. It is a front view which shows the main structures of the ventilation drying apparatus. It is a perspective view which shows the ventilation drying chamber 410 of the state in which the several glass plate G was accommodated.

Explanation of symbols

200 Head coater 220 Die head 230 Slit 300 Vacuum dryer 400 Blower dryer 410 Blower dryer 420 Blower 500 Head coater 600 Vacuum dryer 700 Heating device 800 Temporary baking furnace

Claims (8)

A coating step of applying a liquid functional coating agent on the surface of the glass plate to form a liquid film on the surface of the glass plate; a heating step of heating the glass plate on which the liquid film has been formed and firing the liquid film; A method for producing a glass sheet with a functional thin film, comprising:
Between the application step and the heating step, the step of drying the applied liquid functional coating agent,
The drying process includes a vacuum drying process and a blow drying process subsequent to the vacuum drying process.   The manufacturing method of the glass plate with a functional thin film of Claim 1 with which the glass plate which passed through the said vacuum-drying process is air-dried simultaneously in the said ventilation drying process. The manufacturing method of the glass plate with a functional thin film of Claim 1 or 2 with which the material which satisfy | fills the following conditions is used as said functional coating agent.
[Conditions] In an atmosphere of a temperature of 21 ° C. and a humidity of 30%, the time taken to drop 0.05 g on the glass plate and fix it is 7 minutes or more.   The said application | coating process is implemented by the slit coat method which moves the position of a slit with respect to a glass plate, discharging a functional coating agent from a slit on the surface of a glass plate. Manufacturing method of glass plate with functional thin film.   The method for producing a glass sheet with a functional thin film according to claim 4, wherein a material having a viscosity of 0.1 to 10 centipoise is used as the functional coating agent.   The method includes a second application step of applying a second functional coating agent between the drying step and the heating step, and a second drying step of drying the applied second functional coating agent. The manufacturing method of the glass plate with a functional thin film in any one of 1-5.   The said ventilation drying process is a manufacturing method of the glass plate with a functional thin film in any one of Claims 1-6 performed by the fine wind with a wind speed of 0.1-1.0 mm / sec. A coating device that applies a functional functional coating agent to the surface of the glass plate and forms a liquid film on the surface of the glass plate;
A drying device for drying the liquid functional coating agent applied by the coating device;
A heating device that heats the glass plate from which the functional coating agent has been dried by the drying device, and bakes the liquid film,
The drying apparatus includes: a vacuum drying apparatus; and a blower drying apparatus that blows and drys the functional coating agent vacuum-dried by the vacuum drying apparatus.

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