JP2003266910A - Rotary screen process printing method and printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary screen process printing method which can always perform stable printing by obtaining a good printing film without unevenness by controlling the occurrence of cobwebbing associated with ink splitting occurring in a cylindrical screen plate and the split part of a base material and an apparatus for the method. <P>SOLUTION: In the screen process printing method which has the cylindrical screen plate and a squeegee installed inside the screen plate, rotates the screen plate continuously, and prints ink just in front of the squeegee on a base material for printing contacting the screen plate through a cylindrical screen plate hole by the lack of the squeegee, the ink having a storage modulus of elasticity G' and a loss modulus of elasticity G" in a range in which the storage modulus of elasticity G' (dyne/cm<SP>2</SP>), when an x-axis is made a measured frequency (rad/s), and a y-axis is made the storage modulus of elasticity G', is made y=2x or below in the measured frequency of 1-100 rad/s, and the loss modulus of elasticity G" is shown by y=31.934x<SP>0.8359</SP>or below in the measured frequency of 1-100 rad/s is used for printing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sensitive ribbon, a sublimation type ink ribbon, a battery, a condenser, a scratch card and the like, and ink is passed through a screen plate by a squeegee to a printing substrate such as paper, film and metal foil. The present invention relates to a rotary screen printing method and a rotary screen printing apparatus for printing a solid pattern design.

[0002]

2. Description of the Related Art In the production of heat sensitive ribbons, sublimation type ink ribbons, batteries, condensers, etc., a squeegee (3) is provided inside the rotary screen plate (1) so that the squeegee (3) is provided between the opposing backup rolls (4). When the screen printing as shown in FIG. 1 for printing on the substrate (5) to be printed is used, a rotary screen plate (1) having the same pattern opening as the solid image pattern to be printed as shown in FIG. With the squeegee (3) in which the ink in the plate is pressed against the screen plate (1), the ink immediately before the squeegee is adhered to the printed substrate (5) such as paper or film which is in contact with the screen plate through the screen plate, Since a solid printed pattern is formed and the printed film that is printed is a functional film that exerts its function, extremely high flatness of the coating film is required. Speaking in cm, below is desired 1.0μm.

Usually, for example, printing inks used for thermal recording ribbons, sublimation type ink ribbons and the like have high liquid viscosities of 2000 to 20000 mPa.multidot.s. Remained, and the flatness of the printed film surface was significantly reduced. Although the mechanism of occurrence of threading at the splitting portion is not clear, in threading, some of the ink droplets that have passed through the ink passage holes of the rotary screen plate aggregate to form a thread. Alternatively, it is considered that bubble formation and thread formation due to bubble generation and growth due to variation in the internal pressure of the ink in the width direction of the rotary screen plate due to a decrease in the internal pressure of the ink immediately before the division due to the division of the ink. As a result, it is considered that the print film surface waviness is generated due to the trace of the yarn pulling, but it is not yet clear.

For this reason, empirically, the management of humidity in the printing environment, the addition of a conductive material in order to improve the electric conductivity of the ink, and the addition of various compounds to the ink each time have been dealt with.

However, particularly in the case of thermal recording ribbons, sublimation type ink ribbons, batteries and the like, the printed film itself has a function, and it is practically difficult to cope with the additives due to the limited performance of the printed film. Further, in functional film formation, an organic solvent is often used as a solvent, and particularly when a low boiling point solvent is used, the solvent is likely to evaporate due to the low boiling point solvent and the solid content concentration of the ink changes remarkably and is stable for a long time. It is difficult to maintain a very high coating flatness.

[0006]

SUMMARY OF THE INVENTION Therefore, in view of the above problems, an object of the present invention is to suppress the occurrence of stringing due to ink splitting occurring at the splitting portion of a cylindrical screen plate and a substrate, and to provide a printing film. An object of the present invention is to provide a rotary screen printing method and apparatus capable of always performing stable printing by obtaining a good printed film without surface irregularities.

[0007]

[Means for Solving the Problems] Further, the above problems are
(1) “A cylindrical screen plate and a squeegee installed inside the cylindrical screen plate are provided, and the ink immediately before the squeegee is formed into a cylindrical shape by continuously rotating the cylindrical screen plate and scratching the squeegee. In a screen printing method in which ink is printed on a substrate to be printed that is in contact with the cylindrical screen plate through a screen plate hole, a storage elastic modulus G ′ (dyn / cm ² ) of the printing ink is measured at a frequency (rad / s) measured along the x axis. ), And the storage modulus G'on the y-axis,
At the measurement frequency of 1 to 100 rad / s, y = 2x or less, and similarly, the loss elastic modulus G ″ is measured at frequencies of 1 to 10
A rotary screen printing method characterized by printing using an ink having a storage elastic modulus G ′ and a loss elastic modulus G ″ within a range of y = 31.934 × ^0.8359 or less at 0 rad / s ”, (2) In the printing method for continuous printing for a long time by the rotary screen printing method,
The rotary screen printing method according to item (1), wherein the solid content concentration of the ink supplied into the cylindrical screen plate is printed while being diluted with an ink solvent so as to maintain the ink solid content concentration at the start of printing. (3) "Rotary according to the above (1) or (2), characterized in that the openings at both ends of the cylindrical screen plate are covered, and printing is performed in a generally sealed state inside the plate. Screen printing method ”, (4)“ In the rotary screen printing method, printing is performed while spraying a gas containing an ink main solvent from a fluid discharge slit toward a separation portion between a cylindrical screen plate and a substrate to be printed. The rotary screen printing method according to (1) above,
(5) The rotary screen printing method according to the item (4), wherein the discharge pressure of the discharge gas is 200 mmAq or less.

Another object of the present invention is to provide (6) the "cylindrical screen plate and the squeegee installed inside the cylindrical screen plate, which is continuously rotated by the squeegee of (6) according to the present invention. In the screen printing method, in which the ink immediately before the squeegee is printed on the substrate to be printed that is in contact with the cylindrical screen plate through the cylindrical screen plate hole by holding the ink, so that the cylindrical screen plate is kept in a generally sealed state. A rotary screen printing apparatus comprising a lid member for closing the openings at both ends ", (7)" Cylindrical screen plate and a squeegee installed inside the cylindrical screen plate. The ink immediately before the squeegee is passed through the cylindrical screen plate hole by rotating the screen plate continuously and scratching the squeegee. A screen printing method for printing ink on a substrate to be printed in contact with a cylindrical screen plate, characterized by comprising a gas discharge device containing an ink main solvent toward a separation portion between the cylindrical screen plate and the substrate to be printed. And a rotary screen printing device ".

The operation of the present invention will be specifically described below with reference to the drawings. (1) of the present invention uses the rotary screen printing apparatus shown in FIG. 1 to print a film having a function of a solid rectangular pattern as shown in FIG. When (dyn / cm ² ) is the measurement frequency (rad / s) on the x-axis and the storage elastic modulus on the y-axis, y = 2x at the measurement frequency of 1 to 100 rad / s.
The loss modulus G ″ shown below is also y = 31.934x at measurement frequencies of 1 to 100 rad / s.
^By printing with an ink having a storage elastic modulus G ′ and a loss elastic modulus G ″ within the range shown by ^0.8359 or less, a thread generated at the split portion between the cylindrical screen plate and the substrate to be printed during printing. The unevenness of the coating surface due to the pulling phenomenon can be suppressed, and a coating surface with high flatness can be obtained.

Although the mechanism of the storage elastic modulus G'of the printing ink and the flatness of the coated surface is not clearly understood, the storage elastic modulus G'of the printing ink is higher in the range of y = 2x. If it comes off, the elastic component of the printing ink will increase, and the thread generated by the stringing phenomenon of the printing ink at the splitting part will be hard to break because it will be thicker as if it were a spring, compared to the case where the elastic component is small. Therefore, it is considered that a long thread is easily formed at the split portion, and a trace of threading is likely to remain on the coated surface.

When the loss modulus G ″ is the measurement frequency on the x-axis and the loss modulus on the y-axis, the measurement frequency is 1 to 100 rad.
/ S is printed by using an ink having a loss elastic modulus G ″ within the range of y = 31.934 × ^0.8359 or less at the time of printing, which occurs at the split portion between the cylindrical screen plate and the substrate to be printed. It becomes possible to obtain a coating surface with high flatness due to the leveling effect on the coating surface against the coating surface unevenness caused by the stringing phenomenon.

The mechanism of loss elastic modulus G "of printing ink and goodness of flatness of the coating surface is not clearly understood, but loss elastic modulus G" is higher in the range shown by y = 31.934 ^{× 0.8359.} If it goes out of the range, the viscous component of the printing ink will increase, and the leveling effect will not be obtained for the unevenness of the coating surface that occurs as a trace of the stringing phenomenon of the printing ink at the split portion, and the unevenness of the coating surface after printing growing.

It is desirable that the loss modulus G ″ of the printing ink is low, but if it is too low, the printing speed and the rotation speed of the cylindrical screen plate can be obtained although the leveling effect for unevenness of the coated surface after printing can be obtained. Depending on the printing condition, the printing ink inside the cylindrical screen plate easily leaks through the plate holes during printing, and the liquid that leaks out of the cylindrical screen plate easily causes stains on the pattern non-printing area. Will be needed.

(2) of the present invention uses the printing ink and dilutes it with an ink solvent so that the solid content concentration of the ink supplied into the cylindrical screen plate is maintained at the ink solid content concentration at the start of printing. By printing while performing, high flatness of the coated surface can be obtained after printing. When performing continuous printing for a long time by the printing method, in order to obtain a high flatness of the coating surface after printing in the long-term continuous printing, the ink in the cylindrical screen plate during printing is a major factor that hinders the flatness. There is a change in storage elastic modulus and loss elastic modulus as the solid concentration increases. Therefore, by keeping the solid content concentration of the ink in the cylindrical screen plate during printing substantially constant, a coated surface with high flatness can be obtained.

The solvent used for dilution may be any solvent as long as the solid content concentration of the printing ink in the plate can be kept substantially constant, but the printed printing film mainly used in the present invention exerts its function. In the field of functional film deposition,
It is desirable to use the solvent used in the material composition of the printing ink. Regarding the method of diluting the printing ink, it suffices that the solid content concentration of the printing ink in the plate is kept substantially constant, and during printing, it may be diluted at regular intervals or continuously. About does not matter.

According to (3) of the present invention, the openings at both ends of the cylindrical screen plate are covered, and printing is performed in a generally sealed state inside the plate, so that the flatness of the coated surface is greatly deteriorated during continuous printing for a long time. It becomes a factor. It is possible to suppress an increase in the ink solid content concentration of the in-plate printing ink, and it is possible to obtain a coated surface with high flatness. The lid member used to close the openings at both ends of the cylindrical screen plate is not particularly limited in terms of its material and shape, but when solvent-based solvent ink is used for printing, a highly conductive material is desirable from the standpoint of static electricity countermeasures. It is particularly desirable to use a metal lid member.

In the case of (4) of the present invention, when printing is performed using the printing ink, a gas containing an ink main solvent is blown from the fluid discharge slit toward the split portion of the cylindrical screen plate and the substrate to be printed. By printing while applying, it becomes possible to obtain a coated surface with high flatness. By blowing the gas containing the main solvent of the ink toward the split part between the cylindrical screen plate and the substrate to be printed, the gas does not pull the thread of the stringing phenomenon that occurs at the split part and cuts the thread. Thus, since a partial gas flow of the blown gas acts as if to smooth the coating surface, it is possible to obtain a coating surface having high flatness.

The gas containing the main solvent of the ink sprayed onto the split portion is, for example, a gas containing the main solvent of the ink is sprayed onto the split portion when an ink composed of a solvent that evaporates very quickly is used for printing. Therefore, after the ink in the plate holes is extruded by the squeegee, it is possible to suppress the drying of the ink remaining in the plate holes, but when printing continuously for a long time, the film thickness level decreases with the passage of printing and pinholes are generated. Suppression becomes possible.

According to (5) of the present invention, when printing is carried out using the printing ink, a gas is sprayed from a gas discharge slit containing an ink solvent toward the split portion of the cylindrical screen plate and the substrate to be printed. On the other hand, by setting the discharge pressure of the discharge gas at the time of printing to 200 mmaq or less, it becomes possible to obtain a coated surface with high flatness. If the discharge pressure of the gas containing the ink solvent is set to 200 mmaq or more, the sprayed gas causes the cylindrical plate to vibrate, which causes roughening of the coating surface due to plate vibration, and obtains a highly flat coating surface. Becomes difficult.

(6) of the present invention is a printing apparatus provided with a lid member so as to close the openings at both ends so as to keep the inside of the cylindrical screen plate generally sealed when printing is performed using the printing ink. By printing, as described in the explanation of the function (3) of the present invention, it becomes possible to obtain a coated surface having high flatness.

(7) of the present invention, in the case of printing using the printing ink, printing provided with a gas discharge device containing an ink main solvent toward the split portion between the cylindrical screen plate and the substrate to be printed. By performing printing with the apparatus, it becomes possible to obtain a coated surface with high flatness, as described in the explanation of the function (4) of the present invention.

[0022]

EXAMPLES In order to further clarify the effect of the present invention, examples will be given. [Embodiment 1] FIG. 5 shows a diagram of the apparatus used in Embodiment 1.
Printing was performed under the following conditions. -Printing ink storage elastic modulus G ': measurement frequency 1 to 100
In rad / s, y = 0.4934 × ^1.2368 printing ink / loss elastic modulus of printing ink G ″: measurement frequency 1 to 100
In rad / s, y = 13.131x ^0.8924 printing ink division unit spraying the fluid represented by: the ink solvent in which alcohol containing solvent gas air dividing unit fluids spraying pressure: 100MmAq-cylindrical screen plate Outer diameter: 203 mm-Cylindrical screen plate thickness: 100 μm-Cylindrical screen plate mesh size: 135 mesh-Printing pattern: 25 mm x 204 mm solid rectangular pattern-Substrate: Polyester film thickness 50 μm-Substrate printing tension: 6 kg / 300 mm width-Backup roll outer diameter: 110 mm-Backup roll material: Steel-Printed dry film thickness: 5 μm-Printing speed: 10 m / min * The storage elastic modulus and loss elastic modulus were measured by RFS2 manufactured by Rheometrics.

[Example 2] Storage modulus G'of printing ink: Measurement frequency 1 to 100
In rad / s, y = 5.409 × ^0.7961 printing ink / loss modulus G ″ of printing ink: measurement frequency 1 to 100
In rad / s, printing was performed in the same manner as in Example 1 except that the printing ink ^represented by y = 41.951 × ^0.7967 was used.

[Embodiment 3] ・ Splitting fluid spray pressure: 220 mmAq Printing was performed in the same manner as in Example 1 except for the above.

Next, as the flatness of the coated surface of Examples 1 to 3, the maximum undulation Wcm of the filtered wave was measured, and the results are summarized in Table 1.

[0026]

[Table 1] * Maximum wave swell Wcm is sur manufactured by Tokyo Seimitsu Co., Ltd.
It was measured by fcom 580A.

[0027]

As is apparent from the detailed and specific description, the printing method according to claims 1 to 5 and the printing device according to claims 6 and 7 of the present invention allow storage elastic modulus and loss elasticity of printing ink. By using the printing ink whose ratio is in the range described in the claims, it becomes possible to obtain a printed film having a highly flat coated surface.

[Brief description of drawings]

FIG. 1 is a side sectional view showing rotary screen printing of the present invention.

FIG. 2 is a diagram showing an example of printing by rotary screen printing according to the present invention.

FIG. 3 is a side sectional view showing claim 6 of the present invention.

FIG. 4 is a side sectional view showing claim 7 of the present invention.

FIG. 5 is a printing apparatus used in the first embodiment of the present invention.

[Explanation of symbols]

1 Rotary screen version 2 shafts 3 squeegee 4 backup roll 5 base materials 6 printed designs 7 Cylindrical both end opening lid member 8 Gas spray nozzle containing ink main solvent

Continued front page    F-term (reference) 2C035 AA11 RA07 RA24 RA41                 2H113 AA01 AA05 BA12 BC02 EA04                       EA23

Claims (7)

[Claims] 1. A cylindrical screen plate and a squeegee installed inside the cylindrical screen plate. The cylindrical screen plate is continuously rotated to cover the ink immediately before the squeegee by scratching the squeegee. In a screen printing method in which ink is printed on a substrate to be printed that is in contact with the cylindrical screen plate through a screen plate hole, the storage elastic modulus G ′ (dyn / cm ² ) of the printing ink is measured at a frequency (rad / rad) measured along the x axis. s) and y is the storage elastic modulus G ′, y = 2 at a measurement frequency of 1 to 100 rad / s.
x or less, and similarly, the loss elastic modulus G ″ is the measurement frequency 1
At 100 rad / s, y = 31.934 ^{× 0.8359}
A rotary screen printing method characterized by printing using an ink having a storage elastic modulus G ′ and a loss elastic modulus G ″ within the ranges shown below. 2. In the printing method of continuously printing for a long time by the rotary screen printing method, an ink solvent is used so that the solid content concentration of the ink supplied into the cylindrical screen plate is maintained at the start of printing. The rotary screen printing method according to claim 1, wherein the printing is performed while performing dilution. 3. The rotary screen printing method according to claim 1 or 2, wherein the openings at both ends of the cylindrical screen printing plate are covered, and printing is performed in a substantially sealed state inside the printing plate. 4. In the rotary screen printing method, printing is performed while spraying a gas containing an ink main solvent from a fluid discharge slit toward a separation portion between a cylindrical screen plate and a substrate to be printed. Item 2. The rotary screen printing method according to Item 1. 5. The discharge pressure of the discharge gas is 200 mmAq.
The rotary screen printing method according to claim 4, wherein: 6. A cylindrical screen plate and a squeegee installed inside the cylindrical screen plate. The cylindrical screen plate is continuously rotated to cover the ink immediately before the squeegee by scratching the squeegee. A screen printing apparatus that prints ink on a substrate to be printed that is in contact with the cylindrical screen plate through a cylindrical screen plate hole, and a lid member that closes the openings at both ends so as to keep the cylindrical screen plate in a generally sealed state. A rotary screen printing device characterized by being provided. 7. A cylindrical screen plate and a squeegee installed inside the cylindrical screen plate. The cylindrical screen plate is continuously rotated to cover the ink immediately before the squeegee by scratching the squeegee. A screen printing apparatus for printing ink on a substrate to be printed which is in contact with the cylindrical screen plate through a hole in the screen plate, and a gas containing an ink main solvent toward a separation portion between the cylindrical screen plate and the substrate to be printed. A rotary screen printing device comprising a discharge device.