JPH0675191B2 - Cylindrical printing plate manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a seamless (seamless) tubular printing plate for flexographic printing and other purposes.

2. Description of the Related Art The following method is conventionally known as a method for producing a relief printing plate, particularly a seamless resin plate such as a flexographic printing plate, using a photosensitive resin.

(I) A method in which a photosensitive resin layer is formed on a cylindrical support member by external coating, and then this layer is subjected to relief exposure. For example, on a steel cylinder a given thickness (e.g. about 1.
A method in which a cured polymer layer having a thickness of 5 mm) is attached with an adhesive, an uncured photosensitive resin layer is applied and formed thereon to a predetermined thickness (for example, about 1.0 mm), and then this layer is subjected to relief exposure.

(Ii) A method in which a photosensitive resin sheet is wrapped around a tubular support member, seams are joined together by heating and pressing, and then this sheet is subjected to relief exposure. For example, wrap an unexposed photosensitive resin sheet exactly along the outer diameter of a cylinder, wrap a shrink film from above, and then soften the sheet by depressurizing and heating to homogenize the joined part A method in which the surface is smoothed by a calendering device, and then this sheet is subjected to relief exposure.

(Iii) A method in which a liquid photosensitive resin liquid is filled into the gap between the outer tube and the inner tube of the double tube to solidify it, and then the solidified layer is subjected to relief exposure.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above method (i), since a seam is formed when the cured photosensitive resin sheet is attached onto the cylinder, an uncured photosensitive resin layer is formed by coating on it. Sometimes the film thickness is likely to be uneven at the seam, and in order to apply the uncured photosensitive resin layer to a predetermined thickness, the coating operation and the drying operation must be performed many times. In this case, there are problems that the process operation becomes extremely complicated and that the coating thickness is difficult to be uniform.

In addition, in the method (ii), it is difficult for even a skilled person to wind the unexposed photosensitive resin sheet around the cylinder so that both ends are accurately aligned, and heating is performed to homogenize the joint. As a result, the quality of the unexposed sheet may be impaired, and further, since the bonded portion is not strictly homogenous, there is a possibility that a problem may occur when a fine continuous image is obtained.

Further, the method (iii) requires a high degree of dimensional accuracy in forming the double tube in order to make the film thickness uniform, and has a serious drawback that air bubbles easily enter the resulting cylindrical photosensitive resin sheet. There is.

The methods (i), (ii), and (iii) all involve two steps, that is, the step of forming a photosensitive layer and the step of exposing, so that there is a problem that the manufacturing process of the printing plate becomes complicated. It was

In view of such a situation, the present invention has been made to find an industrially advantageous method for manufacturing a seamless cylindrical printing plate having a uniform film thickness.

Means for Solving the Problems The method for producing a tubular printing plate of the present invention, in producing a seamless tubular printing plate, supplies a photosensitive resin liquid to the inside of a tubular body having actinic ray transmission. , The photosensitive resin liquid is uniformly attached to the inner surface of the cylindrical body by centrifugal force by rotating the cylindrical body at a high speed to form a layer of the photosensitive resin liquid, and the actinic ray is irradiated from the inside of the cylindrical body so that the photosensitive resin liquid The layer of the resin solution is back-exposed from the inside, and the layer of the photosensitive resin solution is relief-exposed from the outside by irradiating an actinic ray from the outside of the cylinder through the image carrier. The above object was achieved by finding such a specific method.

In the present invention, since the obtained tubular printing plate is reinforced from the inside, the following measures (a) or (b) can be taken.

(A) After back-exposing the layer of the photosensitive resin liquid from the inside by irradiating actinic rays from the inside of the cylinder, the support forming resin liquid is further supplied to the inside of the cylinder, and this cylinder is rotated at high speed. Then, the support-forming resin liquid is uniformly attached to the inner surface of the cylinder by centrifugal force to form a layer of the support-forming resin liquid, and then this layer is cured.

(B) The layer of the photosensitive resin liquid is back-exposed from the inside by irradiating the actinic ray from the inside of the cylinder, and then a cylindrical support having an outer diameter capable of contacting the exposed layer is inserted.

Hereinafter, the method for manufacturing the tubular printing plate of the present invention will be described in detail.

As the photosensitive resin liquid in the present invention, the following types are used.

(A) Photopolymerization composition system consisting of photopolymerizable monomer and polymer Examples of the system belonging to this system include, for example, a type in which a monofunctional monomer is photopolymerized in a polymer matrix, and a polyfunctional monomer is a polymer matrix. Photopolymerization type or a type in which a monofunctional monomer is added thereto, a type in which a monofunctional monomer is photopolymerized in a prepolymer, and a polyfunctional monomer and a monofunctional monomer are photopolymerized in a prepolymer Examples include a type, a type composed of a prepolymer and a polymer, and the like.

Examples of the photopolymerizable monomer include acrylic acid esters of polyhydric alcohols, urethane type acrylic acid esters, unsaturated esters of polyhydric carboxylic acids, unsaturated acid amides, acetylenically unsaturated group-containing monomers, glycidyl group-containing monomers and the like. As the polymer, various polymers or prepolymers including epoxy resin, polyester, polyurethane, polyether, polyamide, polyacrylic acid or maleic acid copolymer, silicone resin, cellulosic resin, and synthetic rubber polymer. Is exemplified.

(B) System consisting of photosensitive compound and polymer As a system belonging to this system, those using dichromate as a photosensitive compound, those using an aromatic diazo compound, those using an aromatic azide compound, organic Examples thereof include those using a halogen compound and those resulting from crosslinking an unsaturated polymer with a photopolymerization initiator.

(C) System composed of a polymer having a photosensitive group As a compound belonging to this system, a polymer having a cinnamoyl group, a polymer having a diazo group, a polymer having an azide group and the like can be mentioned.

Then, in the present invention, a tubular printing plate is produced using such a photosensitive resin liquid as follows.

That is, a cylinder having actinic ray transparency is arranged so that its center line is in a substantially horizontal direction, the photosensitive resin liquid is poured into the cylinder by an appropriate supply tool while rotating the cylinder at a low speed, and then Rotate the cylinder at high speed. Due to this high speed rotation, the photosensitive resin liquid adhering to the inner surface of the cylinder is diffused to the inner surface of the cylinder by a centrifugal force, and a layer having a uniform film thickness is formed without containing bubbles. A coating layer for facilitating peeling may be formed in advance on the inner surface of the cylinder.

Here, the actinic rays refer to ultraviolet rays, X-rays, electron beams and the like. Further, as the material of the cylindrical body having an actinic ray transparency,
In addition to various inorganic glasses, organic glasses made of polymethylmethacrylate, polystyrene, polyolefin, polyvinyl chloride, etc. are used.

If the system is moved to a depressurized condition while the cylinder is rotating, the possibility of bubbles entering the photosensitive resin layer to be formed is further reduced.

When a uniform layer of photosensitive resin liquid is formed on the inner surface of the cylinder,
The layer of the photosensitive resin liquid is back-exposed from the inside by irradiating the actinic ray from the inside of the cylinder. Prior to the back exposure, masking exposure may be performed by irradiating the inside of the cylindrical body with an actinic ray through a masking film to form a relief supporting base. Simultaneously with or before and after the back exposure, the layer of the photosensitive resin liquid is subjected to relief exposure from the outside by irradiating an actinic ray from the outside of the cylinder through an image carrier (negative or positive film).

Here, as the light source when the actinic rays are ultraviolet rays, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, a black light and the like are used.

After finishing the above-mentioned back exposure and relief exposure,
Remove the photosensitive resin liquid exposure layer from the inner surface of the cylinder, then wash out the unexposed area by spraying a washout solution, etc., and further dry and post-exposure as necessary to obtain the desired seamless cylinder shape. A printing plate can be obtained.

If the cylinder has a slight taper, by controlling the viscosity of the photosensitive resin liquid and the rotation speed of the cylinder, a cylindrical printing plate or a film having a slight taper instead of a right cylinder can be obtained. Since it is possible to obtain a tubular printing plate that gradually becomes thicker from one end to the other end, it is possible to easily attach and detach the cylinder to and from the cylinder during use.

Then, in the present invention, after the back exposure of the layer of the photosensitive resin liquid from the inside by irradiating the actinic ray from the inside of the cylindrical body (if the back exposure is finished, before or after the relief exposure, (A) In addition, (a) Further, the support forming resin liquid is supplied to the inside of the cylinder, the cylinder is rotated at a high speed, and the support forming resin liquid is evenly attached to the inner surface of the cylinder by centrifugal force. Forming a layer of the support-forming resin liquid,
Then, this layer may be cured, or (b) a cylindrical support having an outer diameter capable of contacting the back exposure layer may be inserted inside the cylindrical body. This is because the tubular printing plate thus obtained is reinforced from the inside.

In the case of (b), it is also possible to reinforce the tubular support by inserting the resin into the tubular support and further solidifying the resin liquid while uniformly diffusing the resin by centrifugal force.

As the tubular support in (b) above, a tubular seamless fabric obtained by bag-weaving, a tubular metal net, a tubular metal plated net, a tubular plastic net, a tubular fiber A knitted fabric is exemplified.

The seamless cylindrical printing plate obtained by the method of the present invention is useful as a resin plate for letterpress printing, particularly as a resin plate for flexographic printing, and in addition, a resin plate for rotary screen printing, a resin plate for intaglio, and a lithographic plate. It can be used for resin plates and other purposes.

Action The photosensitive resin liquid supplied to the inside of the cylinder is diffused to the inner surface of the cylinder by the centrifugal force when the cylinder is rotated at a high speed, and a layer having a uniform film thickness containing no bubbles is formed.

Then, while rotating the cylinder, the layer of the photosensitive resin liquid is back-exposed from the inside by irradiating the actinic ray from the inside of the cylinder, and the actinic ray is irradiated from the outside of the cylinder through the image carrier. The layer of the photosensitive resin liquid is subjected to relief exposure from the outside.

After the exposure is completed, the resin in the unexposed portion is appropriately recovered, and the unexposed portion is washed to obtain a completely cylindrical seamless printing plate in the circumferential direction.

EXAMPLES Next, the present invention will be further described with reference to Examples.

Example 1 FIG. 1 is a partially cutaway front view showing an example of an apparatus used for carrying out the method of the present invention, and FIG. 2 is a left side view thereof.
FIG. 3 is a side view of a main part.

Reference numeral (1) is a glass cylinder, which is arranged so that its center line is horizontal, and its side surface on the base end side is closed by a side plate (2). The tubular body (1) is configured to be rotatable at a low speed and a high speed around a rotation shaft (3) attached to the outside of the side plate (2). (C) is a negative or positive film as an image carrier provided in close contact with the outer periphery of the cylindrical body (1).

(4) is a weir provided inside the free end side of the tubular body (1). Although illustration is omitted, a lid having a central opening may be detachably provided instead of or together with the weir (4).

Reference numeral (5) is a box body that covers the entire tubular body (1), and a door (6) is provided on the free end side of the tubular body (1), and a window (7) made of a glass plate is provided on the door (6). ) Is attached. (8) is a handle for opening and closing the door (6), and (9) is a hinge.

(10) is a chemical lamp as an example of an actinic ray irradiation source provided in large numbers inside the box (5).

In FIGS. 1 and 2, (11) is a base, (12) is a motor for rotating the rotary shaft (3), (13) is a pulley attached to the drive shaft of the motor (12), and (14). Is a pulley attached to the rotary shaft (3), and (15) is a belt connecting these pulleys (13) and (14). (16) is an operation panel, (17) is a switch, (18) is a vacuum gauge,
(19) is a speed tachometer, and (20) is temperature control. (21) is a temperature sensor provided in the cylindrical body (3).

Reference numeral (22) indicated by a chain line is a supply tool for supplying the photosensitive resin liquid to the inside of the cylindrical body (1).
2) After extraction, a high pressure mercury lamp (10 ') as an example of an actinic ray irradiation source is inserted and installed at this position.

FIGS. 4 to 5 show an example of a supply tool for supplying the photosensitive resin liquid into the inside of the cylindrical body (1) in the apparatus shown in FIGS. 1 to 3, and FIG. FIG. 5 is a sectional view in the width direction, FIG. 5 is a partial sectional view in the length direction, and (22) is a long “ton” -shaped supply tool (A) is a photosensitive resin liquid.

Using the above-mentioned apparatus, a cylindrical photosensitive resin structure was manufactured as follows.

Open the door (6) of the box (5) and insert the supply tool (22) containing the photosensitive resin liquid (A) into the back of the cylinder (1) as indicated by the alternate long and short dash line in FIG. Insert it all the way, operate the motor (12), rotate the cylinder (1) at a low speed of 100 rpm, gently invert the supply tool (22), pour the photosensitive resin liquid (A), and then supply the supply tool (22 ) Was pulled out and a high pressure mercury lamp (10 ') was inserted in this position. The cylindrical body (1) was rotated at a high speed of 1,000 rpm, and the photosensitive resin liquid (A) was uniformly attached to the inner surface of the cylindrical body (1) by centrifugal force. In this state, the cylinder (1)
While continuing high-speed rotation of the vacuum gauge (1
7) is operated to put the inside of the box (5) and the cylinder (1) under reduced pressure conditions, and then the relief exposure by irradiation of the chemical lamp (10) and the back exposure by irradiation of the high pressure mercury lamp (10 ') are performed. went. The exposure time was longer in the back exposure.

After the exposure was completed, the cured tubular structure was peeled from the tubular body (1) and pulled out, and a washout solution was sprayed onto the outer peripheral surface to wash away the uncured portion, and then water was sprayed to rinse it. After drying, the cylindrical structure was set on a rotating body, and the outer peripheral surface thereof was irradiated with ultraviolet rays for post-exposure. As a result, a cylindrical printing plate having a thickness of 7.0 mm was obtained.

Embodiment 2 FIG. 6 is a partially cutaway front view showing another example of the apparatus used for carrying out the method of the present invention, and FIG. 7 is a left side view thereof.

(1) is a glass cylinder, which is arranged so that its center line is horizontal, and is supported by supporting rolls (23) at the upper one place and the lower two places near both ends of the outer periphery thereof. ing. (C) is a negative or positive film as an image carrier provided in close contact with the outer periphery of the cylindrical body (1). A driven gear (24) is provided on the outer circumference of the base end side extension of the tubular body (1). It should be noted that both ends of the inner circumference of the tubular body (1) are formed in different steps so as to form a weir (4).

The drive gear (25) is attached to the box body (5) so as to rotate together with the drive shaft (26) below the base end side extending portion of the tubular body (1). The driven gear (24) meshes with the drive gear (25).

In the figures, the meanings of other symbols are the same as those in FIGS.

FIGS. 8 to 9 show an example of a supplying tool for supplying the photosensitive resin liquid into the inside of the cylindrical body (1) in the apparatus shown in FIGS. 6 to 7, and this supplying tool is It has a C-shaped cross section. FIG. 8 is a cross-sectional view in the width direction, FIG. 9 is a partial cross-sectional view in the length direction, (22) is a long “ton” -shaped supply tool, and (A) is a photosensitive resin liquid.

A tubular printing plate was produced as follows using the above apparatus.

The supply tool (22) containing the photosensitive resin liquid (A) is attached to the cylindrical body (1).
Through which the photosensitive resin liquid (A) is placed while gently rotating the cylinder (1) at a low speed of 60 rpm to rotate the supply tool (22) to set the photosensitivity. The resin liquid (A) was poured, then the supply tool (22) was pulled out, and the high pressure mercury lamp (10 ') was inserted at this position.

Next, when the cylindrical body (1) was rotated at high speed at 600 rpm, the photosensitive resin liquid (A) was uniformly attached to the inner surface of the cylindrical body (1) by centrifugal force. While continuing the high speed rotation of the cylindrical body (1), first, back exposure was performed by irradiation with a high pressure mercury lamp (10 '), and then relief exposure was performed by irradiation with a chemical lamp (10).

After the exposure is completed, the high pressure mercury lamp (10 ') is pulled out, the rotation of the tubular body (1) is once stopped, and a tubular seamless fabric (manufactured by bag-weaving as an example of the tubular support (27).
The outer peripheral surface of which is coated with an adhesive and which has an outer diameter capable of contacting the layer formed above) is fitted so as to fit snugly with the resin layer formed on the inner surface of the cylindrical body (1),
An infrared lamp was inserted into the part where the high pressure mercury lamp (10 ') was pulled out, and then the cylinder (1) was restarted to rotate and the adhesive was solidified by irradiation of the infrared lamp.

After the solidification of the adhesive was completed, the rotation of the tubular body (1) was stopped, and the tubular structure was peeled from the tubular body (1) and pulled out,
A photosensitive resin cured layer (B) was laminated on the outer peripheral surface of the cylindrical support (27) to obtain a cylindrical structure as shown in the sectional view of FIG. 10. Was sprayed on to wash away the uncured portion, followed by spraying with water to rinse. After drying, set the tubular structure on the rotating body,
The outer peripheral surface was irradiated with ultraviolet rays for post-exposure. As a result, a cylindrical printing plate having a thickness of 6.0 mm was obtained.

Example 3 After the exposure was completed in Example 2, the high-pressure mercury lamp (10 ') was pulled out, and a supply tool (22) containing a polyurethane resin solution as an example of the support-forming resin solution was inserted and inverted, and then the supply tool. (22) is pulled out, and then the cylindrical body (1) is rotated at high speed to uniformly attach the polyurethane resin liquid to the inner surface by a centrifugal force to form a layer, and an infrared lamp is inserted to irradiate the layer to form a layer. Cured.

After the completion of curing, the rotation of the tubular body (1) was stopped, and the tubular structure was peeled off from the tubular body (1) and pulled out. As a result, the photosensitive resin cured layer (on the outer peripheral surface of the tubular support (27) ( B) laminated
Since a cylindrical structure having a cross-sectional view shown in FIG. 10 was obtained, a washout solution was sprayed onto the outer peripheral surface to wash away the uncured portion, and then water was sprayed to rinse it. After drying, the cylindrical structure was set on a rotating body, and the outer peripheral surface thereof was irradiated with ultraviolet rays for post-exposure. As a result, a cylindrical printing plate having a thickness of 5.0 mm was obtained.

EFFECTS OF THE INVENTION According to the method of the present invention, the photosensitive resin liquid is supplied to the inside of the cylindrical body, and the cylindrical body is rotated at a high speed to uniformly attach the photosensitive resin liquid to the inner surface of the cylindrical body by centrifugal force, and the rotation state thereof. Since the back exposure and the relief exposure are performed in (1), it is possible to easily and collectively obtain a seamless cylindrical printing plate that is completely homogeneous in the circumferential direction.

Moreover, since it is possible to obtain thin to thick ones in any thickness in one step, a conventional method of applying a photosensitive resin liquid in multiple layers, a method of joining end portions by winding, or Compared with the method of filling a liquid photosensitive resin liquid in the gap between the outer tube and the inner tube of the double tube, the production is significantly easier. Therefore, in addition to being excellent in productivity, the uniformity of the film thickness is also extremely excellent.

Further, since the photosensitive resin layer is cured by exposure while rotating the cylinder at a high speed, there is an advantage that no bubbles remain in the obtained cylindrical printing plate.

Therefore, the present invention largely contributes to the field of using a cylindrical printing plate, particularly the field of using a flexographic printing plate.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an example of an apparatus used for carrying out the method of the present invention, and FIG. 2 is a left side view thereof.
FIG. 3 is a side view of a main part. FIGS. 4 to 5 show an example of a supply tool for supplying the photosensitive resin liquid into the inside of the cylindrical body (1) in the apparatus shown in FIGS. 1 to 3, and FIG. A sectional view in the width direction and FIG. 5 are partial sectional views in the length direction. FIG. 6 is a partially cutaway front view showing another example of the apparatus used for carrying out the method of the present invention, and FIG. 7 is a left side view thereof. 8 to 9 show an example of a supply tool for supplying the photosensitive resin liquid into the inside of the cylindrical body (1) in the apparatus shown in FIGS. 6 to 7, and FIG. A sectional view in the width direction and FIG. 9 are partial sectional views in the length direction. FIG. 10 is a cross-sectional view of the tubular structures obtained in Example 2 and Example 3. (1) …… Cylinder, (2) …… Side plate, (3) …… Rotary axis,
(4) ... weir, (5) ... box, (6) ... door, (7)
…… Window, (8) …… Handle, (9) …… Hinge, (10),
(10 ′) …… Actinic ray irradiation source, (11) …… Base, (12)
...... Motor, (13), (14) …… Pulley, (15)…
… Belt, (16) …… Operation panel, (17) …… Switch, (18) …… Vacuum gauge, (19) …… Speed tachometer, (20) …… Temperature control, (21) …… Temperature sensor , (22) …… Supplier, (23) …… Support roll, (2
4) …… Drive gear, (25) …… Drive gear, (26) …… Drive shaft, (27) …… Cylindrical support, (A) …… Photosensitive resin liquid, (B) …… Photosensitive Resin cured layer, (C) ... Image carrier

Claims (3)

[Claims] 1. When manufacturing a seamless cylindrical printing plate, a photosensitive resin liquid is supplied into a cylinder having an actinic ray transmitting property, and the cylinder is rotated at a high speed to be photosensitive by a centrifugal force. The resin liquid is evenly deposited on the inner surface of the cylinder to form a layer of the photosensitive resin liquid, and the photosensitive resin liquid layer is back-exposed from the inside by irradiating actinic rays from the inside of the cylinder, and A process for producing a cylindrical printing plate, which comprises exposing a layer of a photosensitive resin liquid from the outside by irradiating an actinic ray from the outside through an image carrier. 2. A layer of a photosensitive resin liquid is back-exposed from the inside by irradiating an actinic ray from the inside of the cylinder, and then a resin solution for forming a support is further supplied into the inside of the cylinder, The invention is characterized in that a support-forming resin liquid is uniformly attached to an inner surface of a cylinder by high-speed rotation and centrifugal force to form a layer of the support-forming resin liquid, and then the layer is cured. The method for producing a tubular printing plate according to item 1. 3. A layer of a photosensitive resin liquid is back-exposed from the inside by irradiating an actinic ray from the inside of the cylinder, and then a cylindrical support having an outer diameter capable of contacting the exposed layer is inserted. The method for manufacturing a tubular printing plate according to claim 1.