JP3360422B2 - Liquid transfer performance measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for precisely measuring the liquid sending performance of a liquid sending device.
For example, as in a device for feeding a coating liquid for forming a coating film of an organic photoconductor material by spiral coating on the surface of a cylindrical substrate such as an electrophotographic photosensitive drum, liquid feeding performance is required. This is for precisely measuring the liquid sending performance of the liquid device.

[0002]

2. Description of the Related Art Conventionally, the accuracy of a liquid feeding device has been measured by receiving a liquid sent out for a certain period of time into a container and measuring its mass. At that time, it was a large error whether the last one drop of the liquid entering the container entered the container or remained on the liquid sending device side. In order to reduce this error, it is sufficient to lengthen the liquid sending time and increase the measured mass, but among the changing components of the liquid sending speed, a component with a short cycle cannot be measured. In addition, the rise at the start of liquid transfer,
It is very difficult to measure the response characteristics such as falling at the time of stoppage, and a film such as an electrophotographic photosensitive drum having an organic photoconductor film, in which the shape of the end of the film is problematic, is formed by spiral coating. Even in the case where the state of liquid ejection at the start and stop of liquid supply becomes a problem, such as in the case of coating and forming, there is no measurement method, so there was no other way but to evaluate with the actually formed coating film. .

[0003]

As described above, there has been no method for accurately measuring the liquid sending accuracy, response characteristics, and the like of the liquid sending apparatus, but the present inventors have invented the following methods.

[0004]

That is, the cylindrical substrate is rotated about its axis, and the nozzles are relatively moved while discharging the liquid sent from the liquid sending device whose performance is to be measured. The coating film is spirally applied so that the coating film is not substantially connected to the surface of the substrate every rotation by moving the coating film in the axial direction of the substrate, and after drying the coating film, the cross-sectional area of the coating film is reduced. This is a method of measuring the liquid sending performance of the liquid sending device by measuring.

In this method, since the liquid continuously supplied from the liquid supply device is applied to the surface of the substrate in a streak shape, the relationship between the relative speed and position between the substrate and the liquid discharge nozzle is accurately grasped. If so, it is possible to accurately know the time after the start of the liquid feeding at each position of the streak-like coating film, and to measure the cross-sectional area of the streak-like coating film at that position, it is possible to convert to a liquid sending flow rate. .
Since the streak-like coating is formed continuously, if the interval between the measurement positions of the cross-sectional area is reduced, a continuous change in the delivery flow rate can be measured, and a transient response characteristic can be measured.

In the present invention, a cylindrical substrate is used as a substrate on which a coating for measurement is performed. However, even in the case of a film-shaped substrate or a plate-shaped substrate, the substrate and the liquid discharge nozzle are moved by relatively moving the substrate. Measurement of liquid performance is possible. However, in order to accurately measure the response characteristics, the relative speed between the substrate and the liquid discharge nozzle must be increased, and the relative speed can be easily increased by rotating the cylindrical substrate.

For example, a cylindrical substrate having an outer diameter of 80 mm
By rotating at 0 rpm (peripheral speed 838 mm / s) and setting the cross-sectional area measurement position interval to 12 ° (8.4 mm) in the circumferential direction of the substrate, the delivery flow rate can be measured at 0.01 second intervals. In order to increase the relative speed of the plate-shaped substrate with respect to the liquid discharge nozzle in this manner, a very large-scale apparatus is required. This speed is possible with an endless belt-shaped substrate, but a cylindrical device is simpler in terms of equipment.

When measuring the liquid sending performance by the method according to the present invention, it is desirable that the same liquid as the liquid actually sent out by the liquid sending device be sent out at the same flow rate and with the same pressure loss. It may be performed under model conditions. The rotation speed of the cylindrical substrate must be increased to a certain degree because the coating will sag if the coating is too thick, and if it is too fast, the effect of centrifugal force will appear or the coating will be blurred.
An appropriate rotation speed must be selected.

When the viscosity of the liquid is low or the flow rate of the liquid is large, an appropriate rotation speed may not be obtained. However, the liquid discharge nozzle is devised to form two or more striped coatings simultaneously. Suitable conditions can be obtained by a method such as enlarging the width of the streak-like coating film. The cross-sectional area of the streak-like coating film can be measured by various film thickness measuring devices, surface roughness measuring devices, and the like.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a cylindrical substrate, an outer diameter of 80 mm and a thickness of 1
mm, a 340 mm length aluminum alloy substrate, and the liquid used is a CTL (charge transfer layer) of an electrophotographic photosensitive member.
A coating liquid for forming was used, and a plunger type dispenser for spiral coating was used as a liquid sending device. 2 cylindrical substrates
While rotating the liquid discharge nozzle at 40 rpm and moving the liquid discharge nozzle at 15 mm / s, a signal indicated by a broken line in FIG. 2 is sent to the dispenser, the liquid is discharged from the liquid discharge nozzle, and spiral coating is performed on the surface of the cylindrical substrate. Was. After drying, the cross-sectional shape of the coating film was measured with a surface roughness shape measuring device Surfcom 550A manufactured by Tokyo Seimitsu Co., Ltd. FIG. 1 shows a part of the result. The cross-sectional area was obtained from the measurement result of the cross-sectional shape, and the result converted to the flow rate is shown in the plot of FIG.

Comparative Example Using the same dispenser as in the example, a method of receiving the liquid to be sent out for a certain period of time in a container and measuring the mass thereof was used to measure the rising characteristics of the dispenser. In order to obtain the data, the mass of the liquid to be sent in less than one second must be measured, and the sampling of the sent liquid is difficult,
Could not measure.

[0012]

As described above in detail, according to the measuring method of the present invention, as shown in FIG. 2 of the embodiment, the accuracy and response characteristics of the liquid sending device can be accurately measured. When the discharge state at the start of liquid supply and at the time of stoppage becomes a problem, such as when forming a film whose end portion is questionable by spiral coating like an electrophotographic photosensitive drum having a conductive film, In the past, it was very time-consuming to evaluate the liquid sending device with the coating film actually formed.
ADVANTAGE OF THE INVENTION By this invention, it became comparatively easy and it became possible to perform the precise performance evaluation of a liquid sending apparatus.

[Brief description of the drawings]

FIG. 1 is a cross-sectional shape of a coating film obtained in Example 1.

FIG. 2 shows a result obtained by converting the cross-sectional area of FIG. 2 into a flow rate.

Claims (1)

(57) [Claims] 1. Rotating a cylindrical substrate about its axis,
By moving the nozzle relatively in the axial direction of the base while discharging the liquid sent from the liquid sending device, which is a performance measurement target, from the liquid discharge nozzle, the coating film for each rotation is formed on the surface of the base. A method of measuring the liquid-feeding performance of a liquid-feeding device by spirally applying a coating so as not to be substantially connected, drying the coating film, and measuring a cross-sectional area of the coating film.