JPH1099765A - Adjustment method of recovered cating liquid, adjusting device of recovered coating liquid and coating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the change with time of physical properties of a recovered coating liq. and improve a reusing property by recovering a used coating liq. to mix with a previously prepared coating liq. and moreover controlling a concn. or viscosity of the mixed coating liq. in a prescribed value. SOLUTION: The coating liq. used at a coating machine 1 is collected to a tray 2 for recovering the coating liq., and the coating liq. is recovered from here to a mixing tank 5 provided with an agitator 4 by a piping 3, etc., and mixed with the coating liq. previously prepared in the mixing tank 5. A part of the mixed coating liq. 6 is circulated so that it may be returned to the mixing tank 5 via a flow passage 7 from the mixing tank 5. In the flow passage 7, the coating liq. 6 flows into a circulating pump on the way, then passes through a filter to remove a fine foreign matter in the coating liq. 6, then enters in a temp. correcting process viscometer 10 and viscosity is measured. Then a correcting liq. 11 low in viscosity is supplied to the mixing tank 5 till the viscosity reaches the prescribed value when the measured viscosity is larger than a prescribed value and stopped the supply at the point at which the viscosity reaches the prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a recovered coating liquid for a coating liquid such as a coating liquid for producing a color filter, an apparatus for adjusting the recovered coating liquid, and a coating machine.

[0002]

2. Description of the Related Art When a fine pattern such as a color filter for a liquid crystal cell is formed by a thin film technique using a colored coating solution, the colored coating solution has conventionally been applied by a spin coating method. This method can uniformly control the coating film thickness as required, but has the disadvantage that the coating liquid usage is poor because most of the coating liquid is scattered and cannot be recovered and reused.
On the other hand, application by a roll coating method, a bar coating method, and a lip coating method has also been performed, but these methods can increase the utilization rate of the coating liquid, but the coating liquid is applied during the coating operation. There was a drawback that the physical properties, particularly the concentration, changed with time due to evaporation of the solvent. As described above, when considering the reuse of the recovered coating solution, it is generally necessary to deal with a change with time of the physical properties such as the concentration and the viscosity of the recovered coating solution.

[0003]

SUMMARY OF THE INVENTION The invention according to claims 1 and 2 provides a method for adjusting a recovered coating liquid to improve the reusability of the coating liquid by adjusting the time-dependent changes in the physical properties of the recovered coating liquid. It is. The invention according to claims 3 to 5 provides an apparatus for adjusting a recovered coating liquid for realizing the above method.

[0004]

According to the present invention, a used coating solution is collected and mixed with a previously prepared coating solution.
Further, the present invention relates to a method for adjusting a recovered coating liquid, which comprises adjusting the concentration or viscosity of the mixed coating liquid to a predetermined value. The present invention also provides a method of adjusting the concentration or viscosity of the mixed coating liquid, in which the concentration or the viscosity of the mixed coating liquid is adjusted by circulating a part of the mixed coating liquid, and the concentration or viscosity of the coating liquid in the circulation path. The present invention relates to a method for adjusting a recovered coating liquid, which is performed by measuring the above-mentioned correction liquid and mixing the correction liquid with the above-mentioned mixed coating liquid so that the concentration or viscosity becomes a predetermined value. The present invention also provides a mechanism for collecting the coating liquid used in the mixing tank (5), a flow path (7) for circulating the coating liquid in the mixing tank (5), and a flow path (7). The viscosity indicated by the viscometer (10) in the mixing pump (8) and the process viscometer (10) in the mixing tank (5) is set to a predetermined value in conjunction with the temperature compensating process viscometer (10). The present invention relates to an apparatus for adjusting a recovered coating liquid provided with a mechanism for supplying a correction liquid.

[0005] The present invention also relates to an apparatus for adjusting a recovered coating liquid, which further comprises a filter (9) in a flow path (7). The present invention further provides:
A coating machine comprising the apparatus for adjusting a recovered coating liquid according to claim 3 or 4.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a system diagram showing an example of a coating machine provided with a recovery coating liquid adjusting device according to the present invention. In FIG. 1, a coating liquid used in a coating machine 1 is collected in a coating liquid collecting tray 2, and is collected by a pipe 3 or the like into a mixing tank 5 provided with a stirrer 4. It is mixed with a previously prepared coating liquid. A mechanism in which the coating liquid used in the coating machine 1 is collected in a coating liquid collecting tray 2 and collected in a mixing tank 5 by a pipe 3 or the like from the coating liquid collecting tray 2 collects the used coating liquid in the mixing tank 5. Is an example of a mechanism for this.

Although the stirrer 4 is appropriately provided, it is preferable that the stirrer 4 constantly stirs the coating liquid 6 in the mixing tank 5. This is because the coating liquid prepared in advance in the mixing tank 5 and the recovered coating liquid whose concentration, viscosity, etc. are changed from the mechanism for recovering the coating liquid, and the correction liquid added for adjustment can be quickly changed. This is for uniform mixing.

A part of the coating liquid 6 is circulated from the mixing tank 5 to return to the mixing tank 5 via the flow path 7. In the flow path 7, the coating liquid 6 flows into a circulation pump 8 in the middle thereof, and then passes through a filter 9, where fine foreign substances in the coating liquid are removed. And the viscosity is measured. Here, the installation of the filter 9 is a preferable embodiment. The flow path 7 is formed by a pipe such as a pipe.

When the viscosity measured here is different from a predetermined value, the process viscometer 10 determines whether the viscosity is lower than the viscosity of the coating liquid to be supplied to the place where the coating liquid is to be used, such as the coating machine 1 or the like. A mechanism for supplying a high-viscosity correction liquid to the mixing tank 5 to have a predetermined viscosity is interlocked. That is, when the viscosity measured by the process viscometer 10 is larger than a predetermined value, the correction liquid having the low viscosity is supplied to the mixing tank 5 until the viscosity reaches the predetermined value, and when the correction liquid reaches the predetermined value, the supply is stopped. You. Such a correction fluid is
Only the solvent of the coating liquid may be used, and the composition other than the solvent is the same as the composition of the coating liquid to be supplied to the place where the coating liquid is to be used, such as the coating machine 1, and has a small or large overall concentration. When only a certain component is particularly consumed or dissipated in a place where the coating liquid is to be used, such as the coating machine 1, only the component may have a higher concentration.
In this way, by controlling the viscosity in the circulation channel,
The concentration or viscosity of the coating liquid can be controlled. Also,
As the process viscometer 10, a temperature correction type process viscometer is preferable. Further, a concentration measuring device or the like may be provided instead of the process viscometer.

A specific example of a mechanism for supplying the correction liquid to the mixing tank 5 is a storage tank 12 for the correction liquid 11 and a drip valve 13 for directly controlling the supply of the correction liquid 11 from the storage tank 12 to the mixing tank 5. And piping 14.

The process viscometer 10 and the drip valve 13 are linked so that the drip valve 13 is opened and closed by a control signal issued from a control system for comparing the values related to the viscosity detected by the process viscometer 10. I do. Specifically, the measured value of the process viscometer 10 is transmitted to the control device 15, where a magnitude comparison with a predetermined value is performed. When the measured value is larger or smaller than the predetermined value, the valve is transmitted from the control device to the valve. Open signal is dripping valve 1
3, the dropping valve 13 is opened, the correction liquid 11 in the storage tank 12 is introduced into the mixing tank 5, and when the measured value in the process viscometer 10 reaches a predetermined value, the dropping valve 13 is opened. It is closed, and the introduction of the correction liquid 11 into the mixing tank 5 is stopped. The control device 15 controls the process viscometer 1
0 is provided with a temperature sensor 16. Control device 1
5 is a converter for converting measured values of temperature and viscosity (for example, voltage value) sent from the process viscometer 10 into values for comparison, and comparing a value generated by the converter with a predetermined value. Alternatively, a controller for generating a signal for opening and closing the drip valve 13 may be provided. During this time, the value of the viscosity generated by the converter is a value obtained by correcting the temperature of the coating liquid 6 to, for example, 25 ° C. The control device may be one computer. The opening and closing of the drip valve 12 is performed, for example, by repeating the state of opening for 30 seconds and then closing for 5 minutes. During this time, if the viscosity of the coating liquid 6 reaches a required value, this operation is stopped and closed. Be left alone.

The mixing tank 5 may further be provided with a liquid level gauge 17. Further, it is preferable that the mixing tank 5 and the temperature-correcting process viscometer 10 include a temperature control device (cooling device, heating device, or heating / cooling device) so that the coating liquid has a predetermined temperature. The mixing tank 5 further includes a valve 18 and a supply pump 19 for supplying a coating liquid such as the coating machine 1 to a place where the coating liquid is to be used in order to reuse the coating liquid.
It is preferable that a pipe 20 appropriately provided is installed.

[0013]

According to the above construction, the concentration or viscosity of the coating liquid recovered from the coating machine or the like is measured by a measuring instrument such as a temperature correction type process viscometer and a correction liquid supply mechanism interlocked with the measuring instrument. Alternatively, the concentration or viscosity of the coating liquid can be constantly maintained at a required value by opening the valve for dropping the correction liquid intermittently or continuously with respect to the change in viscosity, thereby enabling the use of the correction liquid. The used coating solution can be collected and reused without being replaced, and as a result, the usage rate of the coating solution is greatly improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is practiced by using an apparatus shown in FIG. 1 (a temperature-correcting process viscometer is used as the process viscometer 10) and using a coating liquid composed of a photosensitive liquid for producing a color filter as a coating liquid. Here is an example of the case. Liquid amount in the mixing tank 5: 2400 ml Circulating amount of the coating liquid in the flow path 7: 1000 ml / min Supply amount of the coating liquid to the coating machine 1: 180 ml / min Coating liquid from the coating machine 1 to the mixing tank 5 Recovery amount: 179 ml / min Initial viscosity of the coating liquid in the mixing tank 5: 25.0 mPa · s (25 ° C.
Correction value) Viscosity of correction liquid (same composition as the above coating liquid except concentration): 20
As a result, the viscosity of the recovered coating liquid from the coating machine 1 to the mixing tank 5 was 25.05 mPa · s (corrected at 25 ° C.).

The collected coating liquid is continuously collected in the mixing tank 5,
When the correction liquid was not introduced, the viscosity of the coating liquid in the mixing tank 5 increased to 25.2 mPa · s (25 ° C. correction value) after one hour.
However, when the viscosity detected by the temperature correction type process viscometer reaches 25.1 mPa · s (correction value at 25 ° C.), the correction liquid is introduced into the 10 ml mixed layer in 30 seconds, and then stopped for 5 minutes. The state is repeated, and the viscosity detected by the temperature correction type process viscometer indicates that the viscosity of the coating liquid in the mixing tank 5 is 25.0 mPa · s.
(25 ° C correction value), when the introduction of the correction liquid was completely stopped, the viscosity of the coating liquid was always 25.0 mPa · s.
(25 ° C. correction value) and 25.1 mPa · s (25 ° C. correction value).

[0016]

According to the method for adjusting the recovered coating liquid according to claims 1 and 2, the physical properties of the coating liquid can be easily adjusted to be constant, and the utilization rate of the coating liquid can be remarkably improved.
The above effects can be achieved with good workability and operability by the recovery coating liquid adjusting device according to claims 3 and 4. With the coating machine in claim 5, it is possible to form a coating film having a uniform thickness on the base material while improving the utilization rate of the coating liquid.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example of a coating machine provided with a recovery coating liquid adjusting device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coating machine 2 Coating liquid collection tray 3 Pipe 4 Stirrer 5 Mixing tank 6 Coating liquid 7 Flow path 8 Circulation pump 9 Filter 10 Temperature correction type process viscometer 11 Correction liquid 12 Storage tank 13 Drop valve 14 Pipe 15 Control device 16 Temperature sensor 17 Level gauge 18 Valve 19 Coating liquid supply pump 20 Piping

Claims (5)

[Claims] 1. A collection method comprising: collecting a used coating solution and mixing it with a previously prepared coating solution; and adjusting the concentration or viscosity of the mixed coating solution to a predetermined value. How to adjust the coating liquid. 2. The concentration or viscosity of the mixed coating liquid is adjusted by circulating a part of the mixed coating liquid and measuring the concentration or viscosity of the coating liquid in a circulation path. The method for adjusting a recovered coating liquid according to claim 1, wherein the method is performed by mixing a correction liquid with the mixed coating liquid so as to obtain a value. 3. A mechanism for collecting the coating liquid used in the mixing tank (5), a channel (7) for circulating the coating liquid in the mixing tank (5), and a In the provided circulation pump (8), process viscometer (10), and mixing tank (5), the viscosity indicated by the viscometer (10) becomes a predetermined value in conjunction with the temperature-correcting process viscometer (10). For adjusting the recovered coating liquid provided with a mechanism for supplying the correction liquid. 4. The apparatus for adjusting a recovered coating liquid according to claim 3, wherein a filter (9) is further provided in the flow path (7). 5. A coating machine comprising the apparatus for adjusting a recovered coating liquid according to claim 3 or 4.