JP2002282754A - Reverse roll coat apparatus and coating method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reverse roll coat apparatus and its coating method, by which a functional thin film or the like such as an infrared absorptive or reflective film or a color film for the purpose of light shielding or decoration is film-formed by coating the upper surface of a plate like body such as a building glass or a vehicle glass non-absorptive to a coating liquid without causing film defects due to the liquid pool at the edge part of the plate like body. SOLUTION: The reverse roll coat apparatus for forming a coating film by coating the upper surface of the plate like body passed just under a applicator roll with the applicator roll rotating in a direction reverse to the transportation direction of the plate like body has a structure that the plate like body is inclined to be elevated in the advance direction when the rear end of the plate like body reaches just under the rotary axial center of the applicator roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating roll which rotates a sheet in a direction reverse to the direction of conveyance while conveying the plate in a horizontal direction with respect to the conveyance roll.
The present invention relates to a reverse roll coater which is a device for applying a coating liquid on an upper surface side of a plate-like body with an applicator roll to form a coating, and a method for applying the reverse roll coater. In particular, the present invention relates to a reverse roll coating apparatus for applying a coating liquid on an upper surface of a non-absorbing plate-like body such as a glass substrate that does not absorb the coating liquid to form a coating without unevenness in film thickness, and a coating method therefor.

[0002]

2. Description of the Related Art A reverse roll coater is generally called a reverse roll coater. For example, as described in "Introduction to Coating Apparatus and Operation Technology" (written by Yuji Harazaki, published by Sogo Gijutsu Center), pp. 75-89. 1 mP on the surface of a plate-like body such as a glass substrate or a plastic film
It is a device that forms a coating by applying a coating liquid in a wide viscosity range from low viscosity of about a · s to high viscosity of about 1 Pa · s. It has good controllability to the desired film thickness, high coating speed, and high productivity. It has the characteristic that the property is good.

[0003] A reverse roll coater is used, for example, on an architectural window glass or a vehicle window glass, etc., for a functional thin film such as an infrared absorbing or reflecting film and an ultraviolet absorbing film, or a colored film for light shielding or decoration. Etc. can be used when forming a film.

FIG. 5 is a schematic side view of an example of a conventional reverse roll coater. As shown in FIG. 5, the plate-like body G placed horizontally is applied to the plate-like body G by an applicator roll 1 provided above the transport roll 4 and the backup roll 2 and rotating in a direction opposite to the transport direction. After a coating solution is applied on the upper surface to form a coating film, the coating solution is usually dried or fired to form a coating film. Specifically, the coating liquid is applied to an applicator roll 1 having a surface made of a rubber elastic body, and is pressed against the applicator roll 1 and rotated to knead the coating liquid to form a metal metal ring for obtaining a predetermined film thickness. After being dropped from the supply pipe 6 or the like, which is a coating liquid supply means, between the roll 3 and the roll 3, the coating liquid is extended on the surface of the applicator roll 1, and
Is moved and applied to the upper surface of the plate-like body G being transported from the surface of the plate-shaped body G.

[0005] The backup roll 2 is disposed immediately below the applicator roll 1 in order to increase the accuracy of controlling the thickness of the film formed on the surface of the plate-shaped body. It is manufactured and arranged with high positional accuracy.

[0006] Also, usually referred to as a doctor blade 7,
The applicator roll 1 is provided with a plate 7 for smoothly spreading the coating liquid on the surface of the applicator roll 1 and eliminating the trace of the surface of the applicator roll 1 due to the intrusion of the plate G.

[0007]

However, when a coating film is formed on the upper surface of a non-absorbable plate-like material, for example, a glass substrate, which does not absorb the coating liquid, by using the above-mentioned reverse roll coating device, the film is conveyed. There is a problem that a film defect occurs due to an increase in the film thickness of the film at the rear end portion of the glass substrate in the direction.

FIG. 2 is a plan view of a glass substrate having a film defect. The film defect 8 usually reaches about 5 mm from the rear end of the glass substrate G, and reaches about 10 mm depending on the application conditions, and is visually conspicuous with cracks and cloudiness. When it was required that the film was not uneven up to the periphery, the product could not be shipped due to poor appearance.

Therefore, in order to ship the product, a coating liquid is applied to a glass substrate G larger than the product size in advance to form a film, and then the glass substrate G is reduced to a predetermined size except for a film defect portion. It had been cut. Accordingly, a loss of the glass substrate G is caused, and a cutting step is added, so that the product is expensive.

FIG. 3 is an explanatory view of the mechanism by which a film defect occurs at the rear edge of the glass substrate. FIG. 3A is an explanatory diagram at the time of coating, and FIG. 3B is an explanatory diagram after coating.

The mechanism of the occurrence of film defects is shown in FIG.
As shown in the figure, in the reverse roll coater, the application roll, that is, the applicator roll 1
Is rotated in the direction opposite to the transport direction, so that a liquid pool 9 is formed in a gap on the upper surface of the glass substrate G, and the liquid pool 9 is formed.
However, the film remains at the rear edge of the glass substrate G as it is, and the thickness of the rear edge of the glass substrate G is increased, resulting in the thick film portion 10 shown in FIG. 3B and the film shown in FIG. Defect 8 results.

[0012]

As a result of intensive studies to solve the above problems, the present inventors have found that a rotatable transport roll for transporting a plate-like body in a horizontal direction and a rotatable transport roll for rotating the plate in a direction opposite to the transport direction. An applicator roll, a rotatable backup roll provided below the applicator roll, and a rotatable metalling roll in contact with the applicator roll. The applicator roll applies a coating liquid to the upper surface of the plate-shaped body to form a film. Using a reverse roll coating device, when applying the coating liquid to the upper surface of a non-absorbable plate-like body such as a glass substrate, when the rear end of the plate-like body reaches just below the applicator roll, preferably a plate After the rear end of the body enters below the applicator roll, just before it reaches just below the center of rotation of the applicator roll,
By providing a transport roll that can be moved up and down, in other words, vertically movable, and by lifting and transporting the leading end side of the plate-like body, a film defect due to a liquid pool of the coating liquid generated at the trailing edge of the plate-like body No longer occurs.

If the timing of lifting the front end of the plate is too early, it is difficult to control the thickness of the coating film on the rear edge, and the rear end of the plate passes just below the center of the rotation axis of the applicator roll. Lifting does not eliminate film defects.

The present invention relates to a rotatable transport roll for transporting a plate-like body in a horizontal direction, an applicator roll rotating in a direction opposite to the transport direction, a rotatable backup roll provided directly below the applicator roll, and an applicator. A reverse roll coating apparatus comprising a rotatable metalling roll in contact with a roll, and applying a coating liquid to an upper surface of a plate by an applicator roll to form a coating, wherein a rear end of the conveyed plate is an applicator roll. A reverse roll coating apparatus characterized by having a mechanism for inclining the plate-like body so as to become higher in the traveling direction when passing just below the sheet.

Further, the present invention is the reverse roll coater as described above, wherein the mechanism is a transport roll capable of moving up and down in a vertical direction.

Further, the present invention provides that the plate-like body is inclined so as to become higher in the traveling direction only when the rear end of the plate-like body to be conveyed passes immediately below the center of the rotation axis of the applicator roll. A coating method using the above-described reverse roll coating apparatus.

Further, the present invention relates to a method for producing a liquid containing an alcohol as a main solvent, having a viscosity of 0.001 Pa · s or more and 0.005 Pa · s or more.
The above-mentioned coating method, wherein in the application of the coating liquid of s or less, an inclination angle of the plate-like body when the plate-like body is inclined so as to become higher in the traveling direction is 4 degrees or more.

FIG. 4 is an explanatory view when a rear end portion of a non-absorbable plate is applied using the reverse roll coating apparatus and the coating method of the present invention.

By using the reverse roll coater and the method for coating the same according to the present invention, a non-absorbable plate such as a glass substrate which does not absorb a coating liquid at the time of coating is generated when a conventional reverse roll coater is used. The reason why the liquid pool of the coating liquid generated at the rear edge of the body G disappears is that when the rear end of the plate-shaped body G reaches directly below the applicator roll 1 in the reverse coating apparatus of the present invention, FIG. As shown in the figure, by lifting and transporting the front end of the plate-shaped body G so that the plate-shaped body G becomes higher in the traveling direction, the rear end edge of the plate-shaped body G is brought to the outer peripheral surface of the backup roll 2. This is because the liquid pool at the rear edge of the plate-like body G moves quickly to the surface of the applicator roll 1 because the liquid pool is separated from the applicator roll 1 while being lowered while being transported along. If the inclination angle is small, the above effect is not sufficiently exerted, and film unevenness occurs at the rear end of the plate-like body G due to liquid pool.

As a result of intensive studies by the present inventors, using the reverse roll coater of the present invention, the viscosity, 0.001 Pa · s or more and 0.001 Pa · s
In the case of applying a coating liquid of 5 Pa · s or less, if the inclination angle of the plate-shaped body G when the plate-shaped body G is tilted so as to increase in the traveling direction is less than 4 degrees with respect to the horizontal, Since a liquid pool is formed at the rear end of the body G, the inclination angle is 4 degrees with respect to the horizontal.
It turned out that it was necessary to be at least a degree.

In order to prevent the flow of the coating liquid on the upper surface of the non-absorbable plate-like body G after coating and to ensure the uniformity of the thickness of the coating film, the rear end of the plate-like body G at the time of coating is required. When is separated from the applicator roll 1, it is preferable to immediately lower the tip side of the plate-shaped body G to a normal transfer level, to transfer the plate-shaped body G horizontally, and to tilt the plate-shaped body G while transferring it. The mechanism moves up and down, that is, the transport roll 5 that can move vertically.
It is preferred that

[0022]

FIG. 1 is a schematic view of a main part of an example of a reverse roll coating apparatus according to the present invention as viewed from a side.

The reverse roll coater of the present invention comprises a rotatable transport roll 4 for transporting the plate G in the horizontal direction.
And an applicator roll 1 rotating in a direction opposite to the transport direction, a rotatable backup roll 2 provided directly below the applicator roll 1, and an applicator roll 1.
, And at least one or more transport rolls 5 that can move up and down in the vertical direction.

The coating liquid is supplied from a supply pipe 6 or the like between an applicator roll 1 rotating in a direction opposite to the direction of transport of the plate-like body and a metal metering roll 3 rotating in contact with the applicator roll 1. Supplied by the equipment,
After being spread on the surface of the applicator roll 1, it is moved and applied from the surface of the applicator roll 1 to the upper surface of the plate-shaped body G. The plate G is coated with the coating liquid by the applicator roll 1 while being conveyed in the horizontal direction by the conveyance roll 4. When the rear end of the plate G passes directly below the center of the rotation axis of the applicator roll 1. Only the tip is lifted by the transport roll 5 that can move up and down in the vertical direction.

The vertically movable transport roll 5 moves up and down while maintaining a horizontal state, and changes the angle in the transport direction of the substrate and the horizontal direction in order to smoothly transport the plate-shaped body G. Needless to say, it is preferable that there is no

The peripheral speeds of the applicator roll 1 and the metering roll 3 do not necessarily have to match.

The means for supplying the coating liquid to the reverse roll coater of the present invention is not particularly limited, and a supply nozzle 6, a dispenser for spraying the coating liquid by air pressure, or the like can be used.

Further, in the reverse roll coating apparatus of the present invention, it is preferable to attach a doctor blade 7 to the applicator roll 1 for eliminating film unevenness due to the entry of the plate-like body.

According to the reverse roll coating apparatus and the coating method of the present invention, the plate G for forming a coating is preferably a non-absorbable plate, and is not limited to a glass substrate, but may be a plastic plate, a plastic film, Examples include a metal plate and a ceramic plate.

The coating liquid to be coated by the reverse roll coating apparatus and the coating method of the present invention is a functional thin film such as an infrared absorbing or reflecting film, an ultraviolet absorbing film, and an antifouling film utilizing the photocatalytic activity of titanium oxide fine particles. Or a coating solution for forming a colored film or the like for the purpose of shading, decoration, or the like.In the preparation of these coating solutions, alcohols, which are compounds in which a hydrogen atom of a hydrocarbon is substituted with a hydroxyl group as an organic solvent, For example, using ethanol, isopropanol, 1-methoxy-2 propanol and the like,
Adjusting the viscosity to a range of 0.001 Pa · s or more and 0.005 Pa · s or less can provide a plate-like body G with a film having no thickness unevenness.
It is preferable because it can be obtained on the surface of.

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples.

[0032]

First, the components of the reverse roll coater of the present invention used in Example 1 and Comparative Examples 1 and 2 will be described.

FIG. 1 is a schematic side view of a main part of an example of the reverse roll coating apparatus of the present invention used in Example 1 and Comparative Examples 1 and 2.

The applicator roll 1 has a diameter of 165 mm
A material obtained by bonding an EPDM rubber, which is an ethylene-propylene-diene copolymer having a thickness of 15 mm, to an iron roll having a diameter of 135 mm was used. The hardness of EPDM rubber is
The Shore hardness was 45 as measured with a Shore durometer A.

As the metalling roll 3, a 162 mm diameter chrome-plated iron roll having an embossed roll surface was used. The embossing was a # 180 lattice type, and the working depth was 45 μm.

The backup roll 2 immediately below the applicator roll 1 was a 140 mm diameter iron roll having a diameter of 114 mm with EPDM rubber having a thickness of 13 mm adhered thereto. The hardness of the EPDM rubber was 70 measured with a Shore durometer A.

The doctor blade 7 was made of steel and had a thickness of 0.5 mm, and was attached to the applicator roll 1.

The transport rolls 4 and 5 have a diameter of 100 mm
A vulcanized rubber having a thickness of 10 mm is attached to an iron roll having a diameter of 80 mm, and a pitch of 200 m is provided before and after the backup roll 2, that is, upstream and downstream.
m, the same peripheral speed as the backup roll 2,
That is, it was driven at the transport speed. Note that the transport roll 5 800 mm downstream from the backup roll 2 uses an air cylinder (not shown) to move the glass substrate G by 60 mm in a direction perpendicular to the transport plane when the rear end of the glass substrate G passes directly below the center of the rotation axis of the applicator roll 1. Then, the plate was raised so that the inclination angle of the plate with respect to the horizontal was 4.3 degrees, and then adjusted to return to the original position after 2 seconds. Example 1 An end face having a chamfered plate thickness of 5 mm and a size of 500 mm × 1000 m
A titania-based photocatalyst film for imparting hydrophilicity and antifouling property was applied and formed on the upper surface of a float glass substrate G (soda lime silicate glass) using the reverse roll coater of the present invention.

First, the glass substrate G was polished with a suspension of cerium oxide and water using a rotary brush, and then the cerium oxide was washed off with a rotary brush and then dried with an air knife. As the coating solution applied to the glass substrate G, an antifouling film forming coating solution for coating the surface of the glass substrate G with an antifouling film by the photocatalytic activity of the titanium oxide fine particles was used. More specifically, a coating liquid is applied to the surface of the glass substrate G, and then heat-cured to form a film for forming an antifouling film. The weight ratio of the oxide component is ZrO ₂ : SiO ₂ : TiO.
ZrO ₂ as a ZrO ₂ source so that ₂ = 3: 4: 4
Cl ₂ and CS which is a silicone reagent as a source of SiO ₂
G-DI-060 (trade name, manufactured by Chisso Corporation);
ST-K01 as TiO ₂ fine particle source and SiO ₂ source
(Trade name, manufactured by Ishihara Techno Co., Ltd.) was dissolved in a mixed solvent of ethanol and 1-methoxy-2-propanol, and the coating for forming an antifouling film was adjusted to a solid concentration of 2% by weight. The viscosity of the adjusted coating solution for forming an antifouling film was measured and found to be 0.003 Pa · S.

Then, the coating solution for forming an antifouling film was applied to the glass substrate G using the reverse roll coater of the present invention.
The conditions for application to the coating are room temperature 25 ° C., humidity 50 to 6
In an environment of 0% RH, the substrate transfer speed of the glass substrate G is set to 50
mm / sec, that is, the peripheral speeds of the transport roll and the backup roll are set to 50 mm / sec, and when the rear end of the glass substrate passes through the center of the rotation axis of the applicator roll 1, the inclination angle of the glass substrate G is changed to the backup roll 2.
After raising the transport roll 5 downstream by 800 mm from the above by 60 mm (4.3 degrees in angle), the transport roll 5 was lowered to the original position and transported 2 seconds later.

The peripheral speed of the applicator roll 1 and the metalling roll 3 is set to 100 mm / sec, and the gap between the applicator roll 1 and the glass substrate G is set to be 0.1 mm.
It was set to 2 mm.

Using the reverse roll coating apparatus of the present invention, the conveying direction is set to the long side direction of the glass substrate G, and under the above-mentioned application conditions, the coating solution for forming an antifouling film is applied to the glass substrate G on one side of the glass substrate G. After coating and coating, heating temperature, 200 ℃
For 10 minutes. When the appearance was visually evaluated, no film unevenness occurred at the rear edge of the glass substrate G, and the appearance was good. Next, the film thickness of the antifouling film after heating at 450 ° C. for 20 minutes to obtain a glass with an antifouling film is 70 n.
m. Comparative Example 1 Using the same reverse roll coater as that used in Example 1, except that only the vertical movement of the transport roll 5 800 mm downstream from the backup roll 2 was not performed, that is, except that the glass substrate G was not tilted,
The coating liquid was applied to one side of the glass substrate G under the same coating conditions using the glass substrate G and the coating liquid having the same size as in Example 1, that is, by a coating method using a conventional reverse roll coating apparatus. After the coating and drying, the appearance was visually evaluated. As a result, cloudy film unevenness was observed at the rear edge of the glass substrate G. Comparative Example 2 Using the same reverse roll coater as that used in Example 1, the rear end of the glass substrate G was applied to the applicator roll 1
When passing immediately below the center of the rotation axis, the 50 mm applicator roll 1 and the backup roll 2
The glass substrate G having the same size as that of the first embodiment except that the conveying roll 5 on the downstream side by 50 mm is raised by 50 mm, the inclination angle of the glass substrate G is set to 3.6 degrees, and the glass substrate G is lowered to the original position after 2 seconds. The coating liquid was applied to one side of the glass substrate G under the same coating conditions using the coating liquid. After the coating and drying, the appearance was visually evaluated. As a result, although slightly smaller than that of Comparative Example 1, film unevenness with cloudiness was observed at the rear edge of the glass substrate G.

[0043]

By using the reverse roll coating apparatus and the coating method of the present invention, the coating liquid is applied to the upper surface of a plate-like body which does not absorb the coating liquid such as a glass substrate by the conventional reverse roll coating apparatus. Occurred when coating,
No film defect occurs at the rear edge of the plate-like body.

Therefore, when the appearance of the outer peripheral edge of the plate-like body is required when it is shipped as a product, a process is performed in which after coating and forming on a substrate having a size larger than the product size, the film-forming defect is cut off to obtain a product. Thus, a glass with a thin film having a good appearance can be provided.

The glass with a thin film that can be provided is a glass with a functional thin film such as an infrared absorbing or reflecting film, an ultraviolet absorbing film, and an antifouling film utilizing the photocatalytic activity of titanium oxide fine particles, or for the purpose of shading and decoration. Glass with a colored film and the like, which can be used for architectural window glass, vehicle window glass, mirrors and the like.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of an example of a reverse roll coating apparatus of the present invention as viewed from a side.

FIG. 2 is a plan view of a glass substrate having a film defect.

FIG. 3 is an explanatory view of a mechanism in which a film defect occurs at a rear edge portion of a glass substrate. (A) It is explanatory drawing at the time of application. (B) It is explanatory drawing after application.

FIG. 4 is an explanatory diagram when a rear end portion of a non-absorbable plate is applied using the reverse roll coating apparatus and the application method of the present invention.

FIG. 5 is a schematic view of an example of a conventional reverse roll coating apparatus as viewed from a side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Applicator roll 2 Backup roll 3 Metering roll 4, 5 Transport roll 6 Liquid supply nozzle 7 Doctor blade

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 3/00 B05D 3/00 D 3/12 3/12 Z 7/00 7/00 P (72) Invention Person Seiji Yamazaki 1510 Oguchi-cho, Matsusaka-shi, Mie F-term in Glass Research Laboratories Central Glass Co., Ltd. EB52 4F040 AA02 AA33 AB04 AC01 BA12 BA18 BA35 CB29 CB33 DA14 4F042 AA02 BA08 CB05 DD07 DD09 DD17 DD20 DD41 DF19 DF28 DF34

Claims (4)

[Claims] 1. A rotatable transport roll for transporting a plate-like body in a horizontal direction, an applicator roll rotating in a direction opposite to the transport direction, a rotatable backup roll and an applicator roll provided immediately below the applicator roll. A reverse roll coating apparatus comprising a rotatable metalling roll to be in contact with, and applying a coating liquid to an upper surface of a plate-shaped body by an applicator roll to form a coating, wherein a rear end of the conveyed plate-shaped body is directly below the applicator roll. A reverse roll coater, which has a mechanism for inclining the plate-like body so as to become higher in the traveling direction when passing through. 2. The reverse roll coating apparatus according to claim 2, wherein the mechanism is a transport roll that can move up and down in a vertical direction. 3. The plate-like body is inclined so as to be higher in the traveling direction only when the rear end of the plate-like body to be conveyed passes immediately below the center of the rotation axis of the applicator roll. An application method using the reverse roll coater according to claim 1 or 2. 4. A viscosity of 0.1 as a main solvent containing an alcohol.
In the application of the coating liquid of 001 Pa · s or more and 0.005 Pa · s or less, the inclination angle of the plate-like body when the plate-like body is inclined so as to become higher in the traveling direction is 4 degrees or more. The coating method according to claim 3, wherein