JPH0143193Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for coating a thin plate-like substrate with a coating liquid using a roll, that is, a roll coater.

[Conventional technology and its issues]

As is well known, a coating device called a roll coater, along with spin coating devices, spray devices, and dipping devices, is used to coat metal films on the surfaces of semiconductors and other substrates, such as glass substrates used in the manufacture of thermal heads. It is used to apply a photoresist solution to the surface of a substrate on which it has been vapor-deposited, in order to create a pattern.

For example, as shown in FIGS. 1 and 2, such a roll coater includes a coating roll 2 that is connected to an appropriate drive device (not shown) and rotatably supported, and a coating roll 2 that is in contact with the coating roll 2. Doctor rolls 3 arranged in parallel so that they can be separated freely
A necessary coating liquid is supplied to the coating roll 2 and the back-up roll 4 which are arranged opposite to each other at a predetermined distance in the axial direction thereof, and to the recess formed between the coating roll 2 and the doctor roll 3. The nozzle 5 and these rolls 2,
It consists of a drain butt 6 provided below the third and fourth groups.

In such a roll coater, the substrate 1 is disposed between the coating roll 2 and the backup roll 4.
By adjusting the contact pressure between the doctor roll 3 and the coating roll 2 or the distance between the back-up roll 4 and the coating roll 2, the coating liquid is applied to the substrate 1 to a desired thickness. It is being applied. At this time, the excess coating liquid falls into the drain vat 6 through the grooves 9 carved on the circumferential surface of both ends of the coating roll 2, and then through the grooves 9' carved on the circumferential surface of both ends of the back-up roll 4. However, when the coating liquid passes through the drain pipe 7 and is used for waste disposal or circulation, when it falls into the drain butt 6 from the grooves 9' at both ends of the back-up roll 4, the coating liquid flows in the drain butt 6 as shown by reference numeral 8. , and the fine mist generated at that time sometimes adhered to the back surface of the substrate 1. Even when the amount of liquid from the liquid supply nozzle 5 is adjusted in accordance with the number of substrates 1 to be processed in order to reduce the adhesion of such fine mist, the number of substrates 1 to be processed is not always constant but fluctuates. Therefore, it was not possible to completely eliminate the dropping of the coating solution.

Furthermore, as the surface processing of the substrate 1 has become finer in recent years, it has become necessary to make the coating liquid applied to the surface of the substrate 1 thinner and more uniform. The contact pressure between or the pressing force of the back-up roll 4 that presses the substrate 1 against the coating roll 2 increases, and as a result, the contact pressure between the substrate 1 and these rolls 2, 4 increases.
Thousands of volts of static electricity is generated between them, causing thread-like coating liquid to fall from the backup roll 4 and a fine mist of coating liquid (hereinafter referred to as
A problem has arisen in that the mist (referred to as mist, etc.) is attracted to the substrate 1, and this mist, etc. adheres to the back surface of the substrate 1.

In particular, at the moment when a substrate 1 made of glass or the like passes between a rubber coating roll 2 and a back-up roll 4 and is fed out while being pressurized, there is an actual Well then
It was found that static electricity of 6000V or more was generated and that most mist etc. adhered to the end of the substrate 1 being sent out.

In addition, in recent years, the width of the substrate 1 has become wider than before, and when an existing roll coater is used, both ends of the substrate 1 are close to the grooves 9 and 9' at both ends of each roll 2 and 4. The distance between the filamentous coating liquid 8' falling from the grooves 9 and 9' of grooves 2 and 4 and the substrate 1 has become shorter, and the problem of mist adhering to the back surface of the substrate 1 due to static electricity has become impossible to ignore.

Therefore, as a measure to remove static electricity, it is possible to use conductive rubber for the rolls, but since solvents are used, there are problems in terms of corrosion resistance and processability, and such measures cannot be adopted. It was hot.

In addition, as a method for removing static electricity, it is known to apply a high voltage to a needle-shaped electrode to cause corona discharge to generate ions, and then remove static electricity by blowing ionized air. Since a solvent with a low flash point is used, such a method could not be adopted.

[Means to solve the problem]

Therefore, the present invention was devised to completely solve these problems, and its main points are a back-up roll that is rotatably attached to the machine frame, and a A coating roll that is rotatably disposed in and that transfers and supplies a coating liquid onto a substrate that is sandwiched and conveyed between the back-up roll and the coating roll that is in contact with and is in contact with the coating roll. In a roll coater equipped with a doctor for storing a coating liquid, a surplus liquid flow downward groove is carved on the circumferential surface near both ends of at least one of the coating roll or the back-up roll, and the surplus liquid flow downward groove is provided with an upper end thereof. There is a roll coater for substrates in which a surplus liquid flowing member is vertically installed, and the members are loosely fitted and come into sliding contact with each other to the extent that rotation of these rolls is not hindered.

〔Example〕

Hereinafter, the structure of the present invention will be described in detail based on embodiments shown in the accompanying drawings. FIGS. 3 and 4 show a first embodiment of the present invention, and parts common to those of the conventional example shown in FIGS. 1 and 2 are designated by the same reference numerals, and their explanations will be omitted.

In the first embodiment, the surplus liquid flow grooves 9' are fitted loosely into the surplus liquid flow grooves 9' cut on the circumferential surface near both ends of the back-up roll 4, and come into sliding contact with each other to the extent that rotation of the back-up roll 4 is not hindered. A member 10 is installed upright on the drain butt 6. This surplus liquid flowing down member 10 is made of a conductive material,
It is grounded. In addition, the surplus liquid flowing down member 10
In order to reduce the friction between the surplus liquid flowing down groove 9' of the back-up roll 4,
0 may be made of a non-conductive material such as plastic. In this case, if the drain butt 6 is made of metal and grounded, charging can be prevented since the coating liquid is conductive. . In addition, the fourth
Reference numeral 12 in the figure indicates a feed roll.

Since the first embodiment has the above-described configuration, even if the coating liquid is supplied from the nozzle 5 and the surplus coating liquid falls from the surplus liquid flow grooves 9 at both ends of the coating roll 2, the coating can be carried out smoothly. The liquid passes through the excess liquid flow groove 9' of the backup roll 4, passes through the excess liquid flow member 10, and flows down to the drain butt 6. Therefore, unlike the conventional example, there is no drop of the thread-like coating liquid 8 or generation of mist, and since these rolls 2 and 4 are grounded, static electricity does not build up on both rolls, and the substrate No mist etc. will adhere to 1.

Next, what is shown in FIGS. 5 and 6 is a second embodiment of the present invention, in which a surplus liquid flow member 10 is installed in a surplus liquid flow groove 9 carved on the circumferential surface of both ends of the coating roll 2. It is equipped with.

In this embodiment, the length of the back-up roll 4 in the axial direction is longer than the dimension of the width direction of the substrate 1 (direction perpendicular to the substrate conveyance direction), and the coating roll 2 is engraved near both ends of the coating roll 2. Since the length is shorter than the length between the surplus liquid flow grooves 9, the surface of the backup roll 4 will not be contaminated by excess liquid.

7 and 8 show a third embodiment of the present invention, and in this embodiment, the upper end of the excess liquid flowing down member 10 is loosely fitted into the excess liquid flowing down groove 9 of the coating roll 2. , the coating roll 2 is in sliding contact with the coating roll 2 to such an extent that it does not interfere with its rotation, and a part of the excess liquid flowing down member 10 is loosely fitted into the excess liquid flowing down groove 9' of the back-up roll 4, so that the rotation of the back-up roll 4 is not hindered. Although the structure is slightly more complicated than the first and second embodiments, it has the effect of almost completely eliminating the inconvenience of mist etc. adhering to the substrate 1. has.

In the conventional example, a glass substrate (for example,
300 x 300 mm) is inserted between the coating roll 2 and the back-up roll 4 and the coating liquid is applied, the voltage of the static electricity charged on the back-up roll 4 will be -1000 V before passing through the glass substrate, but After several glass substrates pass through, it becomes charged to -5000V, and as a result, a considerable amount of coating liquid adheres to the back-up roll 4 in dots, staining the back surface of the glass substrates, making it unusable. It was becoming.

However, according to the present invention, it was confirmed that almost no coating liquid adhered to the back-up roll 4, and no stains were formed on the back surface of the substrate.

[Effect of idea]

According to the present invention, by simply bringing the surplus liquid flow down member into sliding contact with the surplus liquid flow groove of the roll of the roll coater to the extent that rotation of the roll is not hindered, charging of the roll can be prevented, and the surplus liquid can be Since the coating liquid flows down through the excess liquid flowing down member, generation of mist or thread-like coating liquid can be prevented.

Since the roll is not charged with static electricity, dust in the air does not adhere to it, and furthermore, dust can be prevented from being transferred to the surface of the substrate.

Since it is simply a member for flowing down surplus liquid, it has a simple structure, can be easily installed in existing equipment, and is not affected by the material of the coating liquid.

Since there are a pair of members for flowing down excess liquid, electrostatic conductivity is more completely achieved.

[Brief explanation of drawings]

FIG. 1 is a side view of the conventional example, FIG. 2 is a perspective view of FIG. 1, and FIG. 3 is a front view of the first embodiment of the present invention.
4 is a sectional view taken from X to X in FIG. 3, FIG. 5 is a front view of the second embodiment of the present invention, and FIG. 6 is a sectional view taken from Y to X in FIG.
FIG. 7 is a front view of the third embodiment of the present invention, and FIG. 8 is a Z--Z sectional view of FIG. 7. 1...Substrate, 2...Coating roll, 4...
... Backup roll, 10... Surplus liquid flow down member.

Claims (1)

[Scope of Claim for Utility Model Registration] A back-up roll rotatably attached to a machine frame, and a back-up roll that is rotatably disposed above the back-up roll and that is held and conveyed between the back-up roll and the back-up roll. A roll coater comprising a coating roll that transfers and supplies a coating liquid onto a substrate, and a doctor that contacts the coating roll and stores the coating liquid between the coating roll and the coating roll. A surplus liquid flow groove is carved on the circumferential surface near both ends of at least one of the rolls, and the upper end of the groove is loosely fitted into the surplus liquid flow groove, and slides into contact with the roll to the extent that rotation of these rolls is not hindered. Roll coater for substrates with parts placed upright.