JP2023149454A - Waterless offset original plate manufacturing method and manufacturing apparatus - Google Patents

Abstract

To provide a manufacturing method of a waterless offset original plate of a columnar substrate in which a peelable film has the high coatability with respect to a substrate while using a material of an easy-to-peel film for the peelable film for substrate reproduction, which can perform stable printing and can manufacture a high-quality original plate that has the adhesion of a functional film necessary for printing.SOLUTION: A manufacturing method includes: a first application step of spraying a peelable film material from a first applicator provided on the lower side of a columnar substrate to a peripheral surface of the columnar substrate while rotating a shaft of the columnar substrate as the central shaft by using the peelable film material with a specific physical property and applying the liquid peelable film material while making it adhere to the surface of the columnar substrate; a first solidification step of shrinking the peelable film material applied onto the columnar substrate and forming a peelable film on the columnar substrate by performing dry-solidification of the peelable film material applied in such a state that the columnar substrate is rotated subsequently to the first application step; and a second application step of discharging a silicone film material from a second applicator and applying the silicone film material to the surface of the peelable film.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method and apparatus for manufacturing a waterless offset original plate.

Waterless offset printing is a lithographic printing technology characterized by using a silicone material with ink repellency instead of the dampening water used to repel oil-based ink in normal offset printing. In this waterless offset printing, it is common to use a plate material such as aluminum on which a silicone film is formed on the surface of the original plate (Patent Document 1).

Specifically, the silicone material is continuously applied to a long continuous plate, and then the plate is cut into individual lengths depending on the size of the required original plate. After a printing pattern is processed on the original plate to form a printing plate, the printing plate is wound around a cylindrical base material called a plate cylinder and used in a printing machine.

However, in this case, there is a problem in that the edge of the printing plate forms a seam in the circumferential direction on the cylindrical base material, and printing is not possible in the vicinity of this seam. To address this problem, Patent Document 2 proposes an original plate in which the offset original plate is changed from the conventional plate shape to a seamless columnar shape. Furthermore, Patent Document 2 discloses that a resist pattern applied to the matte rough surface of a cylindrical plate base material is subjected to treatments such as ultrasonic cleaning treatment and chemical cleaning treatment, so that the resist pattern is removed from the surface of the cylindrical plate base material. It is disclosed that a printing plate is recycled by removing the pattern portion.

Further, in waterless offset printing, Patent Document 3 proposes a method of coating the surface of a cylindrical plate base material with a silicone resin layer to form a seamless pattern without any seams.

Japanese Patent Application Publication No. 05-094008 International Publication No. 2017/104327 Domestic publication No. 2017/077825

When the shape of the base material of the original plate changes from a conventional plate shape to a cylindrical shape, there are steps in the manufacturing process in which it is difficult to use conventional methods. One of them is the process of forming a necessary functional film on a base material. For example, when using cylindrical base materials, different outer diameters are used depending on the size of the original plate, but when storing and transporting them, they can be stacked like plate-like base materials to make them compact. Since this is not possible, the original plate may be manufactured at a printing shop or printing manufacturer.

If the original plate is manufactured at a printing shop or printing manufacturer, the original plate will be manufactured only in the required number at that location, and the same cylindrical base material will be reused repeatedly due to the storage space and transportation load. is preferable. Reusing this cylindrical base material requires a recycling process in which the functional film formed on the surface of the cylindrical base material is removed after being used as a printing plate, and the functional film is formed again. The silicone material used as the functional film of the waterless offset original plate tends to adhere to the cylindrical substrate and is difficult to remove until it is completely gone. Therefore, a recycling method has been considered in which a release film that can be easily peeled off is provided on a cylindrical base material, a silicone film is formed on the release film, and when the base material is recycled, the release film is peeled off together with the silicone film. However, the release film formed on the surface of the cylindrical substrate needs to have good adhesion to the cylindrical substrate in order to prevent the plate surface from peeling off during printing. Strong adhesion to the cylindrical base material is required in the circumferential direction.

In other words, the release film provided for recycling the cylindrical base material has the contradictory function of not only being easily peelable during the recycling process, but also firmly adhering to the cylindrical base material and not peeling off during the printing process. It is necessary to balance both. However, in the production of waterless offset master plates, coating a liquid release film material on the surface of a cylindrical base material to form a release film also achieves both easy peelability and high adhesion to the cylindrical base material. It was not considered to do so.

That is, the problem to be solved by the present invention is to manufacture a seamless waterless offset original plate with no seams on the surface of a cylindrical base material, while making the cylindrical base material easy to peel from and recyclable. The purpose of this invention is to maintain a high degree of adhesion to a base material and perform stable printing during printing, and an object thereof is to provide a manufacturing method and a manufacturing apparatus for this purpose.

In order to solve the above problems, the present invention provides a method and apparatus for manufacturing a waterless offset original plate having the following configuration.
(1) A first coating step of applying a liquid release film material to the surface of the columnar base material, and a first coating step of drying and solidifying the release film material to form a release film on the surface of the columnar base material. A method for producing a waterless offset original plate, comprising a solidifying step, a second coating step of applying a silicone film material to the surface of the release film, and a second solidifying step of drying and solidifying the silicone film material, The release film material has standard release properties after drying and solidification, such that when the film thickness is 100 μm or less, the product of the release film tensile strength [N/mm ² ] and the coating film thickness [mm] is Using a release film material with an adhesive force exceeding [N/mm], the first application step is performed while rotating the axis of the cylindrical base material as a central axis, with respect to the circumferential direction of the cylindrical base material. Spraying the release film material from a first applicator provided below the cylindrical base material, and applying the liquid release film material while adhering it to the surface of the cylindrical base material,
The first solidifying step is subsequent to the first coating step, and is performed by drying and solidifying the release film material applied while rotating the cylindrical base material, so that the release film material coated on the cylindrical base material is This is a step of shrinking the film material to form the release film on the cylindrical base material, and the second application step is a step of discharging the silicone film material from a second applicator and applying it onto the surface of the release film. This is a step of applying the silicone film material, and is a method for producing a waterless offset original plate, in which a laminate including at least the release film and the silicone film is formed on the surface of a cylindrical base material.

(2) The first application step is performed by reciprocating the first applicator in the axial direction of the cylindrical base material while rotating the cylindrical base material. The method for producing a waterless offset original plate according to (1), characterized in that a coating film is formed by spraying the release film material onto the peripheral surface of the original plate.
(3) The method for producing a waterless offset original plate according to (1) or (2), wherein the liquid release film material has a viscosity of 0.01 to 1 Poise.
(4) The method for producing a waterless offset original plate according to (1) to (3), wherein the second coating step is started while the cylindrical base material is rotated during the first solidification step. It is.
(5) The first solidification step and the second solidification step are performed using wind generated by rotation of the cylindrical base material or air blown from an air nozzle to the coating surface on the cylindrical base material. The method for producing a waterless offset original plate according to any one of (1) to (4) is performed by:
(6) Using a photocurable resin as the release film material, and after applying the release film material, irradiating with light while rotating the base material to solidify the release film material, (1) to (4) A method for producing a waterless offset original plate according to any one of the above.

(7) a first coating means having a fountain nozzle as a first coating nozzle for applying a first coating material to the circumferential surface of the columnar substrate; a second coating means having a second coating nozzle for applying the material; a rotational drive means for rotating the columnar base material about the axis of the cylinder; and a peripheral surface of the columnar base material. a solidifying means by air blowing from an air nozzle or light irradiation to solidify the coating film applied to the surface, a measuring device for measuring the film thickness value of the coating film, the first and second coating means, and the solidifying means. It has at least a controller for switching,
The first and second coating means are provided with moving means for moving the first coating nozzle and the second coating nozzle in the direction of the rotation axis of the cylindrical base material, and the rotational drive means further includes The coating material is applied by moving the first and second coating nozzles by the moving means while the cylindrical base material is rotated, and the second coating means is configured to apply the coating material based on the measured value of the measuring device. In this waterless offset master manufacturing apparatus, the coating process by the second coating means is started after the solidification means is stopped.

According to the present invention, when manufacturing a seamless waterless offset original plate with no seams on the surface of a cylindrical base material, the release film material applied to the surface of the cylindrical base material is shrunk, and the release film material is peeled onto the cylindrical base material. The laminate structure in which a film is formed and then a silicone film is formed on the surface of the release layer allows the release layer to be easily peeled off from the cylindrical base material, and maintains a high degree of adhesion to the base material during printing and is stable. printing.

As a result, by using these manufacturing methods and manufacturing apparatuses that are compatible with cylindrical shaped base materials, it becomes possible to efficiently manufacture a waterless offset master having an easily peelable film with high quality.

1 is a schematic perspective view showing an embodiment of a manufacturing apparatus according to the present invention. FIG. 1 is a schematic front view showing an embodiment of a manufacturing apparatus according to the present invention. FIG. 3 is a schematic side view showing a first application step and a first solidification step. It is a side surface schematic diagram which shows the 2nd application process and the 2nd solidification process. FIG. 2 is a schematic front view of the configuration of an apparatus for drying and solidifying a coating film. It is a schematic perspective view which shows the formation process of a laminated body.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The present invention will be understood from the following description and drawings, but the embodiments of the present invention are not limited thereto.

The method for producing a waterless offset original plate of the present invention includes a first coating step of applying a liquid release film material to the surface of a cylindrical base material, a drying and solidifying step of the release film material, and a step of applying a silicone film material. The method includes a second coating step and a step of drying and solidifying the silicone film material, and a laminate including at least the release film and the silicone film is formed on the surface of the cylindrical base material. The release film material of the present invention has a standard release property after drying and solidification in which, when the film thickness is 100 μm or less, the product of the tensile strength of the release film [N/mm ² ] and the film thickness [mm] is An easily peelable material exceeding the adhesive force [N/mm] of the film is used, and the first application step is performed on the peripheral surface of the cylindrical base material while rotating about the axis of the cylindrical base material as a central axis. On the other hand, this is a step in which the release film material is sprayed up from a first applicator provided below the cylindrical base material, and the liquid release film material is applied while adhering to the surface of the cylindrical base material. Then, the first solidifying step is performed following the first coating step, and by drying and solidifying the release film material applied while rotating the cylindrical base material, the first solidifying step is performed on the cylindrical base material. The applied release film material is contracted to form the release film on the cylindrical base material. Thereafter, the second coating step is a step of discharging the silicone film material from a second applicator and applying the silicone film material to the surface of the release film. The release film material refers to a release material that becomes a release film, the silicone film material refers to a silicone material that forms a silicone film, and a laminate of a release film and a silicone film is sometimes called a functional film.

In the present invention, the second application method of applying the silicone material is not limited, but in the following description of the embodiments, the second application step will be described using a method similar to the first application step. That is, this is a step in which a coating liquid is sprayed up from a second applicator provided below the cylindrical base material, and the coating liquid is applied while adhering to the surface of the cylindrical base material in an amount greater than the above-mentioned amount.

In the present invention, the silicone material used as the functional film of the waterless offset original plate easily adheres to the cylindrical base material and is difficult to peel off. By placing it between the two, it can be easily peeled off. When the cylindrical base material is recycled, the release film is peeled off along with the silicone film. On the other hand, the release film formed on the surface of the cylindrical base material also requires strong adhesion to the cylindrical base material in order to prevent the plate surface from peeling off during printing.

Here, the standard release properties required for the release film material of the present invention are as follows. Note that the "standard release characteristics" in the present invention is an index representing the release film material based on the characteristics of a release layer formed thinly on a base material by coating or the like with a release material. Here, a release film material that has good releasability, that is, easy releasability, can easily peel off the release film formed on the base material without causing the release film to break when it is peeled off from the base material. This is possible and is related to the tensile strength of the release film itself and the adhesive strength between the base material and the release film. The standard release characteristic of the release material used in the waterless offset original plate of the present invention is that the tensile strength [N] of the release film is greater than the adhesion strength [N] between the base material and the release film.

Here, the tensile strength is the material strength of the release film material in a film state: T [N/mm ² ], and can be measured by a tensile tester specified in JIS B 7721 (2018), From the cross-sectional area [mm ² ] of the width W [mm] and the film thickness t [mm], it is expressed as T/(W·t). Adhesive strength: P [N/m] can be measured by the method of measuring adhesive strength by 90 degree peeling described in JIS Z 0237 (2009), and is expressed as P/W from the width W [mm]. be done. When the thickness of the release film, that is, the film thickness t, is 100 μm or less, it is necessary that the material is an easily peelable film material whose standard release property is T·W·t exceeding P·W. The details of the standard release characteristics and the characteristics of the release film obtained by the manufacturing method of the present invention will be described later.

First, the configuration of an apparatus according to the manufacturing method of the present invention will be explained with reference to the drawings.

<Configuration of manufacturing equipment>
FIG. 1 is a schematic configuration diagram showing an example of an apparatus 100 for manufacturing a waterless offset master plate. FIG. 2 is a front view showing in detail the coating process that is part of the manufacturing apparatus 100 in FIG. 1, and FIGS. 4 is a side view showing the first coating step and the first solidifying step, and FIG. 4 is a side view showing the second coating step and the second solidifying step. Further, FIG. 5 is a front view showing a drying and solidifying process, which is also a part of the manufacturing apparatus 100 of FIG. 1.

In the first coating process of applying a liquid release film material, FIG. It has at least a coating and recovery unit 122a, and the release film material is coated on the surface of the cylindrical base material. The manufacturing apparatus 100 shown in FIG. 1 rotates the cylindrical base material 111 to be coated around the axis, and a first coating nozzle 121a that discharges the coating material is arranged in the axial direction of the cylindrical base material 111. The coating material F is applied to the outer peripheral surface of the base material while being overlapped by moving the coating material F in a reciprocating manner in the moving direction P. Thereafter, while rotating the cylindrical base material 111 around its axis, the coating material F is dried and solidified by injecting airflow from the airflow solidifying means 141 toward the coating material F on the outer peripheral surface of the base material.

1 includes at least a second coating nozzle 121b and a second coating and recovery unit 122b as a second coating process for applying a silicone film material, and in FIG. 1, the second coating process is performed. Waiting away from the cylindrical substrate in order to Although not shown in FIG. 1, after the first coating step and the first solidification step, the silicone material is coated onto the release film by the second coating nozzle 121b and the second coating and recovery unit 122b. , a silicone film is formed through a second solidification step, and a waterless offset printing original plate is manufactured.

Although the manufacturing apparatus 100 in FIG. 1 shows one airflow solidification means 141 used in the first solidification step and the second solidification step, a plurality of airflow solidification means are provided and each of the solidification means is independently operated. It may be subjected to drying and solidification. In FIG. 1, the airflow solidification means 141 is a slit-type nozzle having a slit-like airflow outlet in the axial direction of the cylindrical base material, but other nozzle shapes may be used.

When the airflow solidifying means 141 injects airflow onto the coating surface of the surrounding surface of the base material, the cylindrical base material is rotated so that the airflow is sprayed over the entire surface of the coating film. is preferred. As a result, in addition to promoting the drying of the coating film by the air flow generated on the surface of the substrate due to the rotation of the substrate, it is also possible to suppress liquid flow in the coating film due to the influence of gravity.

In this solidification process, the film thickness value of the paint film is measured by the film thickness sensor 151 shown in FIGS. 3 and 4, and the measured value is taken into the sensor controller 152 to detect the amount of the paint film attached. In addition to controlling the end timing of the first coating step and the start timing of the first solidifying step, the drying and solidifying state of the coating film may be monitored by measuring the change state of the coating film after the first coating step is completed.

For example, the measured value taken into the sensor controller 152 is also transmitted to the interlocking operation controller 150, and when the amount of coating film deposited in the first coating process reaches a state where it can be transferred to the next process, the first solidifying process, , according to a command from the interlocking operation controller 150, a transition is made to the first solidification step. Then, when the dry and solidified state of the coating film reaches a state where it can be transferred to the next step, the second coating step, the step is transferred to the second coating step in response to a command from the interlocking operation controller 150. In the second coating step, the silicone functional layer is coated on the surface of the release film while moving the second coating nozzle 121b in the axial direction of the cylindrical base material 111, as shown in FIG. By injecting airflow from the airflow solidification means 141 shown in FIG. 4 and drying and solidifying the coating film, a laminate in which a plurality of functional films are laminated on a cylindrical base material can be formed.

The manufacturing apparatus 100 of the present invention also includes a rotation drive means for rotating the cylindrical base material 111 shown in FIG. 1, and a movement means for moving the coating means shown in FIG. 2 in the longitudinal direction of the base material (Y direction in the figure). The device may also include a film thickness detection unit including a film thickness sensor 151 and a sensor controller 152 shown in FIGS. 3 and 4. The first and second coating nozzles and coating heads, the airflow solidifying means 141, and the like, the respective moving means and rotating means, and the film thickness detection section may be linked.

Figures 6(a) to 6(d) show each process and its interlocking. Figure 6(a) shows droplet-shaped release film material applied in layers on the surface of a cylindrical base material by reciprocating movement. FIG. 6(b) shows a first solidifying step of drying and solidifying the release film material to form a release film on the surface of the cylindrical base material. 6(c) shows an example of the second coating step of applying the silicone film material to the surface of the release film, and FIG. 6(d) shows an example of the second solidifying step of drying and solidifying the silicone film material. An example is shown. In FIGS. 6A to 6D, each step may be controlled by the interlocking operation controller 150 and the steps may be operated in sequence.

Hereinafter, each means of the apparatus and the formation of the coating film will be explained in detail.
<Rotation drive means>
The rotation drive means shown in FIG. 2 is connected to left and right rotation center shafts 112 and 113 that rotatably support the cylindrical base material 111, support stands 114 and 115 that support the rotation center shafts, and the rotation support shaft, It includes an actuator 116 that rotationally drives the cylindrical base material 111, and a rotation speed controller 117 that controls the actuator and controls the rotation speed of the cylindrical base material 111. The rotation driving means can rotate the cylindrical base material 111 at an arbitrary number of revolutions, and the number of revolutions of the cylindrical base material 111 is set to a number of revolutions suitable for coating or drying and solidifying. be able to. It is preferable that the rotation driving means is controlled independently of the means for reciprocating or linearly moving the first coating nozzle 121a and the second coating nozzle 121b, that is, the arrow (symbol P) in FIG. 1.

<Application means and its transportation means>
The coating means shown in FIG. 3 is the coating means used in the first coating step, and includes a first coating nozzle 121a that sprays the coating material of liquid release film material from the discharge hole and adheres it to the substrate, and a first coating nozzle 121a that supplies the coating material. In addition, it includes a first coating and recovery unit 122a that collects coating material that has fallen without adhering to the substrate, a first liquid pump 123a, and a first coating material tank 124a that stores the coating material. The coating liquid passes from the first coating material tank 124a through a flow path (not shown) in the first coating and recovery unit 122a, and is delivered to the first coating nozzle 121a located at the tip of the first coating and recovery unit 122a. The coating material Fa can be continuously discharged from the discharge hole at an arbitrary discharge amount. Here, the method of supplying the coating material Fa to the first coating nozzle 121a is not particularly limited as long as the coating material Fa can be continuously discharged from the coating nozzle, and a metering pump is used as the first liquid feeding pump 123a. In addition to the method, although not shown, a pressure feeding method may be used in which the first coating material tank 124 is pressurized and the discharge flow rate is controlled by adjusting the pressurized pressure.

Further, FIG. 4 shows a coating means for another second coating nozzle 121b used in the second coating process, but this is also similar to FIG. It includes a recovery unit 122b, a second liquid feeding pump 123b, and a second coating material tank 124b that stores coating material. The coating material Fb can be continuously discharged at an arbitrary discharge amount from the discharge hole of the second coating nozzle 121b located at the tip of the second coating and recovery unit 122b. The method for supplying these coating materials is not limited to the method as in the application means shown in FIG. A different method may be used.

The moving means for each coating means shown in FIGS. 2, 3, and 4 includes stages 131a and 131b that support a first coating and recovery unit 122a and a second coating and recovery unit 122b, and a slider 132 on which the stages move. , includes an actuator 133 that drives the slider, and a controller 134 that controls the actuator, and moves the first coating head 121a and the second coating head 121b at an arbitrary speed in the axial direction of the cylindrical base material 111. can be done. Here, in the first coating process of applying the release film material, the stage 131 has an adjustment mechanism that adjusts the distance between the coating nozzle 121a in the first coating and recovery unit 122a and the cylindrical base material 111. You can.

Further, although it is preferable that the moving means for the first coating nozzle 121a shown in FIG. 3 and the moving means for the second coating nozzle 121b shown in FIG. 4 can be moved and controlled independently, they may share the same moving means. Good too. In the coating operation, the application nozzle 121 is reciprocated by these moving means while the substrate is rotated by the rotation driving means, so that the coating is continuously applied from the coating nozzle 121 to the circumferential surface of the cylindrical substrate. A coating film is formed on the circumferential surface by adhering the coating material to the entire circumferential surface of the substrate while ejecting the material and adhering it to the circumferential surface of the substrate.

Further, the controller 134 shown in FIG. 2 inputs into the application means a determiner that is linked to the movement means of the application means and determines the return position of the reciprocating movement, and position information of the movement means, and executes a predetermined scan. A controller may be used that stores a program to do this. If you want to change the film thickness by using this interlocking motion controller 150, for example, by reducing the thickness of the coating film at a specific location such as the end of a cylindrical base material, you can change the return position of the reciprocating movement, etc. Each parameter related to coating film formation may be controlled based on the set position information of the moving means.

<Solidifying means for drying and solidifying the coating film>
FIG. 3 is a schematic diagram of a cylindrical base material viewed from the side. In FIG. 3, an airflow solidification means 141 having a discharge port for discharging a slit-shaped airflow in the axial direction of the cylindrical base material is used. As shown in FIG. 3, the drying and solidifying means preferably maintains a constant gap in the radial direction from the circumferential surface of the cylindrical base material.

Further, the airflow solidification means 141 includes an airflow injection pressure controller 142 that controls the pressure of gas to be supplied, and a compressed gas supply source 143 that supplies compressed gas to the pressure controller. Airflow can be continuously jetted towards the outer circumferential surface. At this time, as the gas used for the air flow, in addition to dry air, an inert gas such as nitrogen may be used.

Furthermore, although the solidifying means 141 using airflow is shown in FIG. 3, the solidifying means is not limited to this. For example, there is a method of solidifying with a light irradiator. However, the solidification method of the present invention involves high-temperature heating or jetting of hot air used for removing solvents and curing resins, because the solidification method involves an increase in the temperature of the base material and takes time to return to room temperature. Undesirable.

<Film thickness detection section>
The film thickness detection section includes a film thickness sensor 151 and a sensor controller 152 shown in FIGS. 3 and 4. The film thickness sensor 151 is installed toward the circumferential surface position of the cylindrical base material 111, and measures the film thickness of the coating film and imports the measured value into the sensor controller 152, thereby controlling the coating during the coating process. The film thickness value and the drying and solidification state of the coating film during the solidification process can be monitored. At this time, the film thickness value measured by the film thickness sensor is preferably one that measures the front and back surfaces of the paint film to measure the film thickness value, but it also measures the surface height of the base material and the paint film, and The film thickness value may be calculated from the change. At this time, the film thickness value detected by the film thickness sensor 151 and the control device 152 is the average film thickness on the circumferential surface of the cylindrical base material 111, which is the average of a plurality of measured values measured while the cylindrical base material 111 is rotating. However, the value is not limited thereto, and the measurement may be performed only at a specific position on the circumferential surface, and the measured value at that location may be used as the film thickness value.

Further, in the present invention, a confocal laser sensor is used as the film thickness sensor 151, but the present invention is not limited to this, as long as it is a sensor capable of measuring film thickness values in a coating state.

<About coating and forming release film material>
A coating film is formed on a cylindrical base material using the manufacturing apparatus 100 having the above configuration. A method for applying the release film material will be explained. In the coating material filling step, the coating material Fa, which is a release film material that has been sufficiently defoamed, is put into the first coating material tank 124a shown in FIG. The coating material Fa is filled by feeding the liquid into the first coating nozzle 121a and the piping connecting the component parts. In the coating operation process, after fixing the cylindrical base material 111 to the rotation support shafts 112 and 113 shown in FIG. Perform rotation. At this time, the first coating nozzle 121a that discharges the coating material Fa is in a standby state at the axial end of the cylindrical base material 111. Next, the first liquid feeding pump 123a is operated, and the coating material Fa is ejected from the first coating nozzle 121a via the first coating and recovery unit 122a. At this time, by spraying the coating material Fa from below the rotating cylindrical base material 111, a part of the sprayed coating material Fa adheres to the lower surface of the cylindrical base material 111, but the remaining coating material It falls due to gravity and is collected by the coating and collection unit 122a. Then, by moving the coating nozzle 121 and the coating and recovery unit 122 in the axial direction of the cylindrical base material 111, the coating material F adheres to the circumferential surface of the base material to form a coating film. During this coating operation, the amount of movement of the coating nozzle 121 during one rotation of the cylindrical base material 111 is made smaller than the width of the coating film to be adhered, so that the coating films overlap at the edges and form a planar shape. It becomes a coating film.

The coating material F used in this coating operation is preferably one that can control the amount of adhesion to the cylindrical base material 111 to a small extent, has a low coating liquid viscosity, and is diluted with a large amount of solvent, i.e. has a low solid content concentration. The lower the better. The preferred application range for coating is to use a coating material whose viscosity is adjusted to 0.01P to 1P, more preferably 0.03P to 0.5P. That is, in the first coating step of the present invention, the viscosity of the coating liquid of the release film material discharged from the first applicator can be in the range of 0.01P to 1P. More preferably, the viscosity of the coating liquid for the release film material is 0.03P to 0.5P. The unit P of the viscosity of the coating liquid is Poise.

In addition, in order to stably spray the coating material Fa from the discharge hole of the first coating nozzle 121a, the discharge hole of the coating nozzle 121a is preferably large, and the diameter of the discharge hole is 0.1 mm or more. It is preferable to use On the other hand, if the discharge hole of the application nozzle 121a is made too large, the discharge flow rate required for spraying will increase, making it difficult to control a small amount of deposited amount, so the diameter of the discharge hole is preferably 1 mm or less.
<About drying and solidification of release film and silicone film>
First, FIG. 5 shows the configuration of an apparatus for drying and solidifying a coating film. FIG. 5(a) shows a drying and solidifying means using an air flow solidifying means 141, and FIG. 5(b) shows a configuration in which a coating film is solidified using a light irradiator 151, which will be described later. FIGS. 5A and 5B are representative illustrations of the first coating step. The coating film in the following description is a coating film coated with a release film material.

First, the drying and solidifying process will be explained in the configuration shown in FIG. 5(a). After the coating film is applied onto the base material by the application means, drying of the paint film is promoted by spraying airflow from the airflow spraying means toward the circumferential surface of the cylindrical base material while rotating the base material. to dry and solidify the coating film.

In this drying and solidifying process, in order to shorten the processing time, it is effective to raise the temperature of the air stream by about 10 to 30°C from room temperature, but if the temperature of the cylindrical base material rises excessively after drying and solidifying, Since thermal distortion occurs in the cylindrical base material, which affects the accuracy of pattern formation in the next step, it is preferable to process at room temperature without raising the temperature of the air flow.

Next, FIG. 6 shows an example of a method for forming a laminate of a release film and a silicone film. Each process is performed in the order of the first coating process (a), the first solidifying process (b), the second coating process (c), and the second solidifying process (d), and each process is performed until the coating is completed. After that, a stream of air is sprayed over the entire coating to accelerate drying and solidification. Furthermore, the second application process can be started while the cylindrical base material is being rotated during the first solidification process. This is preferable from the viewpoint of further improving adhesion by applying the silicone layer and drying the laminate together before the surface of the release film is completely solidified.

At this time, in each step (a) to (d), the cylindrical base material is rotated, but the rotation speed does not have to be the same. For example, if coating is performed at a rotational speed of 500 rpm and then drying and solidifying is performed at a speed reduced to 25 rpm, leveling of the coating material is likely to occur on the coating surface before solidification, resulting in a high-quality coating film without coating streaks. can do.

Furthermore, as a different means of drying and solidifying, there is also a method of using a photocurable resin that can be easily solidified at room temperature as the coating film material. In this case, if a photocurable resin that does not use a diluting solvent is used, there is no need to use an air jet means. On the other hand, since a light irradiator is required to solidify the resin, a light irradiator 161 and a controller 162 for controlling the irradiation time are installed in the apparatus as shown in FIG. It is preferable to solidify the top coating film on the base material by irradiating it with light.

<About the release film>
In order to reuse the cylindrical base material used for waterless offset masters, after the desired printing is completed, the coating film formed on the cylindrical base material is removed, and a new master plate is reused on the base material. By forming a coating film, the cylindrical base material can be reused.

In offset printing, the resist film on the base material is removed by washing and dissolving it with a chemical solution, but when the silicone material used in waterless lithography is removed from the cylindrical base material by the same method, the silicone material becomes circular. The silicone material adheres to the surface of the columnar substrate, and once it has adhered, it remains thinly on the surface of the columnar substrate, so when the columnar substrate is reused, the surface condition changes and the quality of the original plate deteriorates. Resulting in.

Therefore, as a means to remove the silicone material, a peeling coating film (release film) is formed on the surface of the cylindrical base material under the silicone layer, and the release film is removed from the cylindrical base material together with the silicone layer. By peeling off into a film, the columnar base material can be stably initialized.

The function required of a release film is that it can be easily peeled off from a cylindrical base material, and for this purpose, it is preferable to use a release film material that has film characteristics that satisfy the following formula (1). A release material having this property is determined to have easy release properties, and a release material having such release properties is referred to as an easy release film material.

When peeling a release film from a base material, the forces applied to the film are the tensile force [N] that tries to peel off the film and the adhesion force [N] that tries to keep the film on the base material, and the tensile force [N] ] is greater than the adhesion force [N], the film can be peeled off from the substrate.

When this relational expression is transformed into the balance of forces per unit width [1/mm], it becomes the following equation (1).
Tensile strength (N/mm ² ) x coating thickness (mm) > adhesive strength (N/mm) ... Formula (1)
The tensile strength [N/mm ² ] on the left is the value obtained by dividing the maximum tensile force [N] that can be generated without the film breaking by the cross-sectional area [mm ² ] of the film, and the coating thickness [mm] By multiplying by , the tensile force [N] per unit width [1/mm] is obtained. Further, the adhesive force [N/mm] in the right term is the adhesion force [N] per unit width [1/mm].

In this formula (1), tensile strength x coating film thickness is the film strength that can withstand peeling in the film state when removing the peeling film, and the peeling film will break if the force is less than this film strength. The membrane shape can be maintained without any damage. Furthermore, the adhesive force in the right column is the resistance force that occurs when the release film is peeled off from the base material, and if the film is pulled up with a force greater than this force, the film can be peeled off from the base material. In other words, with a material that satisfies formula (1), the release film can be continuously peeled off from the substrate while maintaining the film shape, whereas under conditions that do not satisfy formula (1), the release film cannot be peeled off. At this time, the release film is torn, and it takes a lot of effort to remove all the release film on the base material. In this way, whether or not a release film has easy peelability can be determined not only by checking whether the material of the film satisfies formula (1), but also by checking how the release film peels off from the base material. You can get a general idea about it.

Here, each item of equation (1) will be explained. The tensile strength in the left column is the material strength when the release film material is in a film state, and can be measured using a tensile tester specified in JIS B 7721 (2018). The tensile strength of the release film is preferably 20 N/mm ² or more in order to hold the functional film as an original, and more preferably 40 N/mm ² or more in consideration of stability. Also in the left column, the coating film thickness is the film thickness when dried and solidified as a peelable film.The thicker the film, the better the strength of the film, but as the film thickness increases, Since drying and solidification require time and material costs are high, an appropriate film thickness is required. The thickness of this peeling film is preferably 100 μm or less, and more preferably 50 μm or less in order to dry and solidify in a short time.

Next, the adhesive strength in the right column is based on the adhesive strength measurement method by 90 degree peeling described in JIS Z 0237 (2009), assuming that the base material has the same surface roughness as the surface finish of the cylindrical base material. Measure. Here, regarding the surface condition of the cylindrical base material in the present disclosure, aluminum was used as the base material (A5052), and the average roughness of the finished surface was Ra1.6.

In addition, according to the relationship of formula (1), the smaller the adhesive force of the release film, the greater the tendency for easy peelability. decreases. Therefore, it is better to have a large adhesive force within the conditions that satisfy formula (1), but when considering the ease with which it can be peeled off manually with fingers, the adhesive force value should be 0.50 N/mm or less. It is preferable, and more preferably 0.10 N/mm or less.

Further, the force with which the release film adheres to the cylindrical base material is improved not only by the adhesive force with the base material in equation (1) but also by the force with which the release film tightens the cylindrical base material. Therefore, if you want to use a release film material that is easier to peel off and still maintain adhesion to the base material, use the shrinkage properties of the release film to shrink the release film on a cylindrical base material. There is also a method of increasing the holding power of the columnar base material.

<About the production of waterless offset master plates>
When manufacturing a waterless offset original plate using the coating method and manufacturing apparatus of the present invention using a cylindrical substrate, after forming a release film on the surface of the substrate in the first coating step and the first solidification step. , a second coating step and a second solidification step form a silicone layer in the form of the release film.

To describe in detail, first, in the first coating step, a coating film is formed on the cylindrical base material in an amount equal to the amount of the release film material calculated from the film thickness after drying and solidification while the cylindrical base material is being rotated. During this application, the amount of coating liquid is sprayed from the first coating nozzle in an amount greater than the amount of material required to form a coating film, and a part of it is attached to the cylindrical base material, so that the flow rate necessary for spraying is It can be applied with a small amount of adhesion while ensuring the same. If the amount of coating can be controlled to a small amount, it becomes possible to form a thin layer by the time the desired film thickness is reached, and by increasing the amount of layered coating, it is difficult to leave traces of spiral coating. A high-quality coating surface can be formed. For example, if the rotation of the cylindrical substrate is stopped midway through, the coating material will flow due to the influence of gravity, resulting in an uneven coating. It is preferable to carry out the rotation while maintaining the rotational state.

Next, in the first coating process, when the coating thickness of the peeling film reaches the set thickness as measured by the film thickness sensor, the first coating process is finished to prevent the shape of the liquid film from collapsing. It is preferable to perform the first solidification step while maintaining the rotational state of the cylindrical base material. In the first solidification step, drying is accelerated by blowing air at room temperature onto the surface of the coating film, and at the same time, the liquid film shrinks and solidifies, so that the release film is solidified so as to grip the cylindrical base material. At this time, the means for solidifying the liquid film may be air blowing or light irradiation using a photocuring resin as the release film material. Resin curing by light irradiation not only has the advantage of suppressing the rise in temperature of the base material, but also has the advantage that the solidification process can be completed in a short time.

Next, the first solidification step is ended by determining the dry state based on the measured value of the film thickness sensor, and then the second application step of applying the silicone film material is started. The transition from the first solidification step to the second coating step may be performed after the release film has completely solidified in the first solidification step, but the transition from the first solidification step to the second coating step may be performed before the release film surface is completely solidified. By doing so, it is expected that not only the manufacturing time of the original plate can be shortened, but also the adhesion between the release film and the silicone layer can be further improved. Further, at this time, the drying and solidification of the release film is completed by additional drying in the second solidification step. After the second coating step is completed, a second solidifying step is performed to produce a waterless offset original plate having a release film and a silicone layer on a cylindrical base material.

In the waterless offset original plate manufactured in this way, the release film part can be formed as a uniform coating film on the circumferential surface of the cylindrical base material, so it is difficult for the release film to peel off during printing, and the film has a long lifespan. Highly sexual.

Furthermore, when reusing the cylindrical base material, since the peeling film is made of an easily peelable material, it is necessary to scratch the functional film with a cutter or the like on a part of the film surface to create a starting point for peeling. This makes it possible to easily peel off the release film along with the silicone layer from the cylindrical base material by hand.
Further, in the present disclosure, a two-layer structure of a release film and a silicone layer has been described for the functional film of the waterless offset original plate, but in addition to these two layers, for example, a printing pattern may be formed between the release layer and the silicone layer. A heat-sensitive layer may be provided for this purpose, and a protective film that can be easily peeled off may also be provided on the outside of the silicone layer. At this time, in the same way as forming a silicone layer on the release film, by increasing the number of coating material coating nozzles, coating means, and coating nozzle moving means according to the number of coating films, the second coating step and The laminated film may be formed by a method similar to the second solidification step.

Hereinafter, specific embodiments of the present invention will be illustrated by Examples. Note that the embodiments of the present invention are not limited to these in any way.

For Examples 1 and 2 and Comparative Example 1, evaluation samples of original plates were prepared under each condition, and then the durability evaluation of the functional film assuming printing and the releasability of the release film assuming substrate recycling were performed. An evaluation was conducted.

For durability evaluation, a rubber roller imitating a blanket during offset printing was pressed against the outer circumferential surface of the original plate, and it was rotated for long periods of time for 50 and 100 hours, and the functional film was in close contact with the cylindrical base material. I checked to see if I could hold it. The evaluation targets were lifting or peeling of the release film from the base material, and peeling of the silicone film from the release film, and the conditions were visually confirmed. The evaluation criteria is "Good: ○" if the functional film did not change its state even after the set durability time (50 hours, 100 hours), and if defects such as peeling or tearing were observed in the functional film. "Poor: x", and those in which lifting occurred in the functional film as a sign of failure, although not reaching x, were evaluated as "slightly poor: △".

Peelability evaluation assumes that the release film will be removed from the base material manually, by making a cut at the end of the functional film on the cylindrical base material and peeling it off in the circumferential direction from there. The laminate of the release film and silicone film was peeled off. Peelability was evaluated as "Good: 〇" if the laminate could be easily peeled off without tearing, and "Poor:" if the laminate was torn into three or more parts and was difficult to peel off. In addition, those that could be peeled off but were not easy because the laminate was torn off in two or less places were rated as "slightly poor: △".

<Example 1>
A laminate of a release film and a silicone film was formed on a cylindrical base material in accordance with the procedure shown in FIG. 6 using a manufacturing apparatus having the same configuration as shown in FIGS. 1 to 4. If a cylindrical base material with an outer diameter of 185 mm and an axial length of 300 mm is used, and a uniformly flat coating film is formed on the circumferential surface of the cylindrical base material in the first coating process, the film thickness after drying and solidification is The stacking amount of the coating film was set to be 50 μm, and the release film was coated in layers using a fountain-type coating nozzle with an outlet diameter of 0.08 mm while the base material was rotating at 50 rpm. In the next first solidification step, the rotation speed of the base material was lowered to 25 rpm, and a slit-type air nozzle was used to apply airflow at a discharge flow rate of 90 m/sec for 10 minutes, while the rotation speed of the base material was maintained at 25 rpm. Continue spraying to dry and solidify the coating. In the second coating process, the rotational speed of the substrate was increased to 500 rpm again, the film thickness was set to 10 μm after drying, and a fountain-type coating nozzle with an outlet diameter of Φ0.5 mm was used. The silicone film material was layered and applied in a spiral manner. In the second solidification step, the rotation speed of the substrate was reduced to 25 rpm, and using the same slit-type air nozzle as used for drying the release film, airflow was applied at a discharge flow rate of 90 m/sec for 10 minutes to the rotation speed of the substrate. The spraying was continued at 25 rpm to dry and solidify the coating film.

Table 1 shows the confirmation results of the durability of the functional film and the releasability of the release film. In the durability check, in Examples 1 to 3, no problems occurred with lifting or peeling of the release film or peeling of the silicone film even after 100 hours.

Further, as the release film material, a diluted solution containing polyurethane as a raw material and N,N-dimethylformamide as a main solvent component and having a solid content concentration of 5 wt% was used. The liquid viscosity of the diluent material was 10 cP, the adhesive force in the film state after drying and solidification was 0.10 N/mm, and the tensile strength was 40 N/mm ² and the film thickness was 50 μm, making it easy to peel.

<Example 2>
A manufacturing apparatus having the configuration shown in FIGS. 1 to 4 plus the light irradiator shown in FIG. 5(b) in the first solidification step is used, and a photocurable coating material is used as the release film material. Then, a release film and a silicone film were formed on the cylindrical base material. In the first coating process, a cylindrical base material with an outer diameter of 185 mm and an axial length of 300 mm was used, and when a uniform and flat coating film was formed on the circumferential surface of the cylindrical base material, the film thickness after solidification was 50 μm. The amount of coating film was set so that the peeling film was applied in a spiral manner using a fountain-type coating nozzle with an outlet diameter of 0.2 mm while the substrate was rotating at 500 rpm. Next, in the first solidification step, the rotation speed of the base material was reduced to 25 rpm, and the base material was irradiated with light for 5 minutes using a light irradiator with an irradiation amount of 300 mW/cm ² while maintaining the rotation speed of the base material at 25 rpm. This was continued to solidify the coating film. Next, in the second coating process, the rotation speed of the substrate was increased to 500 rpm again, the amount of liquid sent by the liquid pump was adjusted so that the film thickness after drying and solidification was 10 μm, and the fountain with an outlet diameter of Φ0.5 mm was used. The silicone material was applied in a spiral manner using a method application nozzle. Next, in the second solidification step, the rotation speed of the base material was lowered to 25 rpm, and a slit-type air nozzle was used to apply airflow at a discharge flow rate of 90 m/sec for 10 minutes, while the rotation speed of the base material was maintained at 25 rpm. The spraying was continued to dry and solidify the coating film, and original plates for the base release layer and upper silicone film were prepared.

The release film material uses a photocurable resin made from polyurethane, and when the material solidifies, the film shrinkage rate is 10%, the liquid viscosity is 50 cP, the adhesive strength in the film state is 0.08 N/mm, and the tensile strength is The peelability was 40N/mm ² and the film thickness was 50 μm.
<Comparative example 1>
In Example 1, the coating means in the first coating step was changed to droplet spraying, and the release film material was coated in a spiral shape so that the film thickness was 50 μm. At that time, the axial movement in the spiral coating was completed only once, and laminated coating was not performed. Further, after the first solidification step, the peeling film was dried and solidified and the silicone layer was formed in the same manner as in Example 1.

The durability of the functional film and the releasability of the release film were confirmed using waterless offset master plates produced under the conditions of Examples 1 to 3 and Comparative Example 1. The results are shown below. Durability was confirmed by setting each original plate in a testing machine that can hold it in rotation, and pressing a rubber roller against the plate surface with a load of 10 kg while holding the rotation speed at 200 rpm, and visually checking the condition of the plate surface after 50 and 100 hours. . In Examples 1 to 3, there were no problems with lifting or peeling of the release film or peeling of the silicone film even after 100 hours. On the other hand, in Comparative Example 1, although no peeling occurred in the silicone film, cracking occurred in a part of the release film over time, and the release film was torn and peeled off from the base material before 100 hours had passed.

To check the releasability, a cut was made in the original functional film using a cutter to partially break the release film, and the functional film was pulled from that point with a finger to confirm whether the release film could be easily peeled off. The results of confirming the durability of the functional film and the removability of the release film are shown. When confirming the peelability, the peeling film could be peeled off by hand under any conditions, but in Comparative Example 1, the film was easy to break during peeling.

100: Waterless offset original plate manufacturing device 110: Rotation drive means 111: Cylindrical base materials 112, 113: Rotation center shafts 114, 115: Support stand 116: Actuator 117: Rotation speed controller 121a: First coating nozzle 121b : Second coating nozzle 122a: First coating and recovery unit 122b: Second coating and recovery unit 123a: First liquid feeding pump 123b: Second liquid feeding pump 124a: First coating material tank 125b: Second Coating material tank 131a: Stage 131b of the first applicator: Stage 132 of the second applicator: Slider 133: Actuator 134: Controller 141 for controlling movement of the application means: Solidifying means by air flow 142: Air jet Pressure controller 143: Compressed gas supply source 150: Interlocking operation controller 151: Film thickness sensor 152: Sensor controller 160: Light irradiator 161: Controller that controls irradiation time F: Coating material Fa: First coating step Coating material Fb: Coating material in the second coating process R: Rotation direction P: Reciprocating direction

Claims (7)

A first coating step of applying a liquid release film material to the surface of the columnar base material, and a first solidification step of drying and solidifying the release film material to form a release film on the surface of the columnar base material. and a second coating step of applying a silicone film material to the surface of the release film, and a second solidification step of drying and solidifying the silicone film material,
The release film material has standard release properties after drying and solidification, such that when the film thickness is 100 μm or less, the product of the release film tensile strength [N/mm ² ] and the coating film thickness [mm] is Using a release film material that exceeds the adhesive strength [N/mm],
In the first application step, a first applicator provided below the cylindrical base material is applied to the circumferential surface of the cylindrical base material while rotating the cylindrical base material about the axis of the cylindrical base material as a central axis. a step of spraying up the release film material and applying the liquid release film material to the surface of the cylindrical base material while adhering it;
The first solidifying step is subsequent to the first coating step, and is performed by drying and solidifying the release film material applied while rotating the cylindrical base material, so that the release film material coated on the cylindrical base material is a step of shrinking the film material to form the peeling film on the cylindrical base material,
The second coating step is a step of discharging the silicone film material from a second applicator and applying the silicone film material to the surface of the release film,
A method for producing a waterless offset original plate, wherein a laminate including at least the release film and a silicone film is formed on the surface of a cylindrical base material. The first coating step reciprocates the first applicator in the axial direction of the cylindrical base material while rotating the cylindrical base material, thereby coating the circumferential surface of the cylindrical base material. 2. The method for producing a waterless offset original plate according to claim 1, wherein the release film material is spouted up to form a coating film. The method for producing a waterless offset original plate according to claim 1 or 2, wherein the liquid release film material has a viscosity of 0.01 to 1 Poise. The method for producing a waterless offset original plate according to any one of claims 1 to 3, wherein the second coating process is started while the cylindrical base material is being rotated during the first solidification process. The first solidifying step and the second solidifying step are performed by using wind generated by rotation of the cylindrical base material or by blowing air from an air nozzle to the coating surface on the cylindrical base material. The method for producing a waterless offset original plate according to any one of claims 1 to 4. Any one of claims 1 to 4, wherein a photocurable resin is used as the release film material, and after application of the release film material, the base material is irradiated with light while being rotated to solidify the release film material. A method for producing a waterless offset master plate. a first coating means having a fountain-type first coating nozzle provided below the columnar base material for applying a first coating material to the circumferential surface of the columnar base material; a second application means having a second application nozzle for applying a second coating material to the peripheral surface;
a rotational drive means for rotating the cylindrical base material about the axis of the cylinder;
Solidifying means for solidifying the coating film applied to the peripheral surface of the cylindrical base material by blowing air from an air nozzle or irradiating light;
It has at least a measuring device for measuring the film thickness value of the coating film, and a controller for switching between the first and second coating means and the solidifying means,
The first and second coating means are provided with moving means for moving the first coating nozzle and the second coating nozzle in the direction of the rotation axis of the cylindrical base material, and the rotational drive means further includes The coating material is applied by moving the first and second coating nozzles with the moving means while the cylindrical base material is rotated, and
The second coating device is a waterless offset master manufacturing apparatus, wherein the second coating device starts a coating process by the second coating device after stopping the solidifying device based on the measurement value of the measuring device.

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