JP2006248191A - Method for producing sheet-like or cylindrical printing base material of resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming fine patterns using a low output laser light source, in a method for producing a printing plate of resin having recessed patterns on the surface using a laser engraving method. <P>SOLUTION: In the method for producing a sheet-like or cylindrical printing base material of resin, a printing original plate of resin comprises a photosensitive resin cured substance having light transmission properties in an ultraviolet ray region, the laser light source used in the laser engraving method is a pulsed oscillation ultraviolet ray laser having a peak output per pulse of 1 J to 20 kJ, wherein the beam diameter of the laser beams output from the pulsed oscillation ultraviolet ray laser is condensed into 0.4 μm to 15 μm, allowing the fine recessed patterns having a width of 0.4 μm or more and less than 20 μm and a depth of 1 μm or more and less than 100 μm to be formed on the surface of the printing original plate of resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to the creation of relief images for flexographic printing plates or dry offset printing by laser engraving, the formation of patterns for surface processing such as embossing, the formation of relief images for printing such as tiles, the conductors of electronic components, semiconductors, insulators, and pattern formation , Pattern formation of functional materials such as antireflection films for optical parts, color filters, (near) infrared cut filters, and alignment films, underlayers, and light emitting layers in the production of display elements such as liquid crystal displays or organic electroluminescence displays Laser engraving printing plate suitable for coating, pattern formation of electron transport layer, sealing material layer, sheet-like or cylindrical resin printing substrate having fine pattern on the surface used when forming a conductor circuit board It is related with the manufacturing method.

  Flexographic printing used for packaging materials such as cardboard, paper containers, paper bags, flexible packaging films, wallpaper materials, decorative materials such as decorative boards, and label printing has increased its specific gravity among various printing methods. For the production of the printing plate used for this, a photosensitive resin is usually used, and a liquid resin or a solid resin plate formed into a sheet shape is used, a photomask is placed on the photosensitive resin, and the mask is used. A method of irradiating light through the substrate to cause a crosslinking reaction and then washing off the non-crosslinked portion with a developer has been used. In recent years, a thin light-absorbing layer called a black layer has been provided on the surface of the photosensitive resin so that finer patterns can be formed, and a mask image is formed directly on the photosensitive resin plate by irradiating it with near infrared laser light. A so-called flexo CTP (Computer to Plate) technique has also been developed in which light is irradiated through the mask to cause a crosslinking reaction, and then the non-crosslinked portion of the light non-irradiated portion is washed away with a developer. However, although this technique uses a near-infrared laser as a laser light source to narrow the laser beam diameter to about 10 μm, it uses a conventional photoengraving technique such as exposure and development, so the pattern size that can be formed is from 20 μm. 30 μm was the limit.

  As another method, Patent Document 1 (Japanese Patent No. 2846954) discloses a laser engraving in which a concave pattern is formed by directly irradiating a resin plate surface with a laser beam and removing the resin irradiated with the beam. However, since the laser light source currently used is a carbon dioxide laser, it is not possible to form a high-definition pattern. This is because it is difficult to narrow the laser beam diameter to 20 μm or less because the oscillation wavelength of the carbon dioxide laser is about 10 μm. Moreover, in this patent document 1, the fundamental wave (wavelength: 1.06 micrometer) of the YAG laser which is a near-infrared laser to the photosensitive resin hardened material which mixed and photocured carbon black for formation of a higher definition pattern. ) To form a pattern. Certainly, it is possible to reduce the laser beam diameter by making the oscillation wavelength of the laser used for engraving shorter, but some ingenuity is necessary to enable engraving using this near-infrared laser. is there. Since general organic compounds do not have strong light absorption in the near infrared region, a dye or pigment having strong light absorption characteristics in this wavelength region is mixed so as to absorb the light of the near infrared laser. Also in patent document 1, the black pigment called carbon black is mixed for near-infrared absorption. However, near-infrared absorbing materials such as such black pigments generally exhibit strong light absorption characteristics even in the ultraviolet region, and in particular, a photosensitive resin cured product that has been photocured with ultraviolet rays is used as a laser. When used for engraving, it has a serious problem of extremely reducing the curability of the photocured product.

  Therefore, in the photosensitive resin system to which the near-infrared absorbing material is added, it has been extremely difficult to achieve both ensuring of laser engraving property and ensuring of mechanical properties. It has been a very difficult problem to obtain a cured photosensitive resin that can be engraved using both near-infrared lasers and infrared lasers and that can ensure mechanical properties. Further, the output of the laser used in the example of Patent Document 1 was extremely large. The average output of the pulsed near-infrared YAG laser described in the examples is 5 W as the smallest example, and a laser with a large average output was used. In addition, there is no description of the pulse width, oscillation frequency, etc., and there is no description of a laser having an oscillation wavelength in the ultraviolet region, but these conditions are extremely important when laser engraving a cured photosensitive resin. is there.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-148329) describes a method of engraving a fine pattern using an ultraviolet laser after engraving the surface of a silicone rubber roll for embossing with an infrared laser. When the silicone rubber is processed using an infrared laser, it is necessary to inject a great amount of energy because the thermal decomposability of silicone is extremely low. Therefore, it is presumed that a laser having an oscillation wavelength in the ultraviolet region, particularly a fourth harmonic of a YAG laser having a wavelength of 266 nm or an excimer laser having a wavelength of 193 nm has been selected as a preferable laser light source for the purpose of breaking the silicone bond. However, when using a laser beam in a short wavelength region of less than 300 nm with a narrowed beam diameter, an expensive material such as quartz is used as a material for a condensing lens or the like so that the laser beam of that wavelength can be transmitted. There was a need to do. Also, there was a problem in ensuring the stability of the laser.

  Rubber materials such as silicone rubber are extremely low in light transmittance of laser light because inorganic fine particles such as carbon black, silica, talc, and calcium carbonate are mixed for the purpose of improving mechanical strength. Therefore, the laser beam having the oscillation wavelength in the ultraviolet region can enter only to the very vicinity of the surface of the rubber material to be engraved, so when engraving in the depth direction, use a laser beam with strong output, It was necessary to sculpt over time. In addition, when using a high-power laser beam, it is difficult to reduce the beam diameter to a sufficiently small size, and even in the concave pattern of the engraved rubber material, the edge becomes unclear or concave due to the melting phenomenon. The width of the pattern has increased, and there have been significant problems with pattern formation.

  In general, the cured photosensitive resin has a large light absorption characteristic at a wavelength of less than 300 nm, and the light transmittance in this wavelength region is significantly reduced. Therefore, when engraving using a pulsed ultraviolet laser, the depth of the cured photosensitive resin that can be engraved with one pulse becomes shallow, and the width of the engraved pattern becomes thick due to the influence of heat in the lateral direction. There is a trend.

  As described in Non-Patent Document 1 (Practical Laser Processing Application Handbook, Optronics, published in 2000), in the manufacture of multilayer printed circuit boards, through holes and via holes for making electrical connections between layers are formed. In the processing, the third harmonic (oscillation wavelength: 355 nm) of a YAG laser is used to remove the glass fiber reinforced thermosetting epoxy resin. As a specific example, there is a description that a laser having a high average output is used. This is because glass fibers that are extremely difficult to remove and epoxy resin that is also difficult to remove are required to be completely removed, and the average output of the laser to be used is required to be high.

Therefore, the surface of the resin printing original plate containing the photosensitive resin cured product layer whose light transmittance is controlled in a portion having a thickness of at least 100 μm from the surface is narrowed down to a small beam diameter of a pulsed ultraviolet laser having a weak average output. There is no laser engraving technique that engraves under conditions and enables the formation of a fine pattern on the surface of a resin printing original plate.
Japanese Patent No. 2846954 JP 2004-148329 A Optronics Editorial Department, "Practical Laser Processing Application Handbook", 1st edition, Optronics, August 28, 2000, pages 135-138

  The present invention forms a fine pattern using a low-power laser light source in a method for producing a resin printing plate having a concave pattern on its surface using a laser engraving method in which a concave pattern is formed by irradiating a laser beam. It aims to provide a method.

  The present inventors have intensively studied, and in the method for producing a sheet-like or cylindrical resin-made printing substrate having a concavo-convex pattern on the surface, a portion irradiated with laser light by irradiating the surface of the resin-made printing original plate Including a laser engraving process in which a concave pattern is formed by removing the resin, and the resin printing original plate is made of a cured photosensitive resin having light transmittance in the ultraviolet region, and is used in the laser engraving process The laser light source is a pulsed ultraviolet laser having an average output of 0.01 W or more and less than 5 W, and an energy amount per pulse of 10 J or more and 50 kJ or less, and the beam diameter of the laser beam output from the pulsed ultraviolet laser is determined. Condensed to 0.4 to 15 μm, width is 0.4 to 20 μm, depth is 1 to 100 μm A fine concave pattern can be formed on the surface of the resin printing original plate, and further, the light transmittance of the photosensitive resin cured product prepared by separately photocuring by setting the thickness to 100 μm is determined by the laser engraving process. It has been found that the above-mentioned problems can be solved by a method for producing a sheet-like or cylindrical resin-made printed substrate characterized in that the oscillation wavelength of the pulsed ultraviolet laser used is 0.1% to 60%. The invention has been completed. Also, in an image that contains both fine and rough patterns, the composition of the cured photosensitive resin can be changed by engraving the fine pattern with a pulsed ultraviolet laser and engraving the coarse pattern with an infrared laser. I found that laser engraving is possible.

The present invention is as follows.
1. The method for producing a sheet-like or cylindrical resin-made printing substrate having a concavo-convex pattern on the surface is formed by irradiating the surface of the resin printing original plate with a laser beam and removing the resin in the portion irradiated with the laser beam. A laser engraving process in which a pattern is formed, the resin printing original plate is made of a cured photosensitive resin having light transmittance in the ultraviolet region, and the laser light source used in the laser engraving process has an average output of 0. 01W or more and less than 5W, a pulsed ultraviolet laser having an energy amount per pulse of 10J or more and 50kJ or less, and condensing the beam diameter of the laser beam output from the pulsed ultraviolet laser to 0.4 to 15 μm And a fine concave pattern with a width of 0.4 μm or more and less than 20 μm and a depth of 1 μm or more and less than 100 μm made of resin. The light transmittance of the cured photosensitive resin that can be formed on the surface of the original plate and is separately photocured by setting the thickness to 100 μm is the oscillation wavelength of the pulsed ultraviolet laser used in the laser engraving process. The method for producing a sheet-like or cylindrical resin-made printing substrate, characterized in that it is 0.1% or more and 60% or less.

2. The laser engraving step further includes a step of laser engraving the surface of the resin printing original plate using a continuous oscillation or pulse oscillation infrared laser, and the beam diameter of the laser beam output from the infrared laser is 15 μm or more and less than 100 μm 1. Condensed light, large width exceeding 15 μm, and a rough concave pattern having a depth of 100 μm or more can be formed. The manufacturing method of the sheet-like or cylindrical resin-made printing base materials as described in 1 above.
3. The oscillation wavelength of a pulsed ultraviolet laser is 300 nm or more and 400 nm or less, and the oscillation wavelength of a continuous or pulsed infrared laser is 5 μm or more and 20 μm or less. Or 2. The manufacturing method of the sheet-like or cylindrical resin-made printing base materials as described in 1 above.
4). 1. The number of beams of a pulsed ultraviolet laser and the number of beams of an infrared laser are at least one. To 3. The manufacturing method of the sheet-like or cylindrical resin-made printing base material in any one of.

5. In the laser engraving process, with the sheet-shaped printing original wrapped around the cylinder surface and fixed, or with the cylindrical printing original mounted on the cylinder, the long axis of the cylinder is fixed and rotated in the circumferential direction, 1. It includes a step of laser engraving by running in the long axis direction of a cylinder or scanning in the long axis direction of the cylinder using a galvano mirror. To 4. The manufacturing method of the sheet-like or cylindrical resin-made printing base material in any one of.
6). In the method of forming a concavo-convex pattern on the surface of a printing plate precursor made of resin by scanning the laser beam in the long axis direction of the cylinder using a galvanometer mirror while fixing the long axis of the cylinder and rotating it in the circumferential direction, the cylinder is rotated once. Then, after engraving the pattern for one round according to the image data divided in the long axis direction of the cylinder, the galvanometer mirror is moved in the long axis direction of the cylinder, or the cylinder is moved in the long axis direction. 4. It is possible to carry out laser engraving of a pattern corresponding to all image data by repeatedly performing the above-described series of steps. The manufacturing method of the sheet-like or cylindrical resin-made printing base materials as described in 1 above.
7). 1. The pulse width of a pulsed ultraviolet laser irradiated on the surface of a resin printing original plate is 1 femtosecond or more and 200 nanoseconds or less, and the repetition frequency is 10 Hz or more and 500 MH or less. To 6. The manufacturing method of the sheet-like or cylindrical resin-made printing base material in any one of.

8). 1. Pulsed ultraviolet laser light is the third harmonic of an end-pump semiconductor laser pumped solid state laser. To 7. The manufacturing method of the sheet-like or cylindrical resin-made printing base materials as described in 1 above.
9. The cured photosensitive resin is formed by photocuring a liquid photosensitive resin at 20 ° C., and the cured photosensitive resin has at least one bond selected from a carbonate bond and an ester bond. And having at least one type of bond selected from a urethane bond, a urea bond and an amide bond. To 8. The method for producing a sheet-like or cylindrical resin-made printing substrate according to any one of items 1 to 8.
10. The depth of the cured photosensitive resin engraved with one pulse of a pulsed ultraviolet laser is 0.05 μm or more and 10 μm or less. To 9. The method for producing a sheet-like or cylindrical resin-made printing substrate according to any one of 1 to 9.

11. The laser engraving apparatus has a pulsed ultraviolet laser, a galvano mirror for scanning the laser beam in the longitudinal direction of the cylinder, a condensing lens for condensing the laser beam, an optical shutter or a mechanical shutter, and the cylinder A mechanism for holding the long axis, a mechanism for rotating the held cylinder in the circumferential direction, and a mechanism for moving the galvano mirror in the long axis direction of the cylinder or a mechanism for moving the cylinder in the long axis direction. Laser engraving device for fine processing.
12 10. The laser engraving apparatus further includes a continuous wave infrared laser and an optical shutter, or a pulsed infrared laser and an optical shutter or a mechanical shutter, and further includes a condensing lens for condensing the laser beam. Laser engraving device for microfabrication described in 1.

  According to the present invention, in a method of manufacturing a resin printing plate having a concave pattern on its surface using a laser engraving method that forms a concave pattern by irradiating a laser beam, a fine pattern is formed using a low average output laser light source. A method of forming can be provided.

Hereinafter, preferred embodiments of the present invention will be described in more detail.
The laser engraving method used in the present invention is a pattern forming method in which a concave pattern is formed by irradiating the surface of a resin printing original plate with a laser beam and removing the portion of the resin irradiated with the laser beam. The resin printing original plate on which the pattern is formed is composed of a cured photosensitive resin formed by irradiating the photosensitive resin composition with light, and the cured photosensitive resin is a laser oscillation used in laser engraving. It has light transmittance at the wavelength.
The light transmittance of the cured photosensitive resin of the present invention is evaluated by the light transmittance at the oscillation wavelength of a laser used for engraving a cured photosensitive resin having a thickness of 100 μm. The light transmittance of the cured photosensitive resin of the present invention is 0.1% or more and 60% or less. Preferably, they are 1% or more and 50% or less, More preferably, they are 5% or more and 40% or less. When the light transmittance is in the range of 0.1% or more and 60% or less, laser engraving in the depth direction is sufficiently deep, and a low average output laser can be used as a light source.

The laser used in the present invention is a pulsed ultraviolet laser having an oscillation wavelength in the ultraviolet region. The ultraviolet region is defined as a region having a wavelength of 400 nm or less. Although it does not specifically limit as an ultraviolet laser, The 3rd harmonic of the semiconductor laser excitation solid state laser or a lamp excitation solid state laser, the 4th harmonic or the 5th harmonic, xenon fluoride, krypton fluoride, argon fluoride, excimer laser using a gas F _2, etc., dye lasers solid laser excitation, can be mentioned Raman laser of a solid-state laser excitation. In particular, a semiconductor laser-excited solid laser is preferable because of its oscillation stability and ease of handling. Specific examples of solid state lasers include alexandrite laser, titanium sapphire laser, Cr: LiSAF laser, F-Center laser, Co: MgF ₂ laser, ruby laser, glass laser, Nd: YAG laser, Nd: YLF laser, Nd: YVO. ₄ laser, Er: glass laser, Ho: YAG laser, Ho: YSGG laser, Tm: YAG laser, Er: YAG laser, and the like. In the case of a semiconductor laser excitation solid-state laser, there are two types of excitation methods, a side pump method and an end pump method, but the end pump method is more preferable in order to obtain an excellent beam shape.

Further, a laser having an oscillation wavelength in a wavelength region of 300 nm to 400 nm is more preferable because it is not necessary to use an expensive material such as quartz for a lens used when condensing the laser beam.
The laser used in the present invention is a pulsed ultraviolet laser, and the repetition frequency is preferably 10 Hz to 500 MHz. A more preferable range is 1 kHz or more and 200 MHz or less, and further preferably 10 kHz or more and 100 MH or less. When the oscillation frequency is in the range of 10 Hz to 500 MHz, it is possible to perform engraving by scanning with a laser beam at high speed, so that the time required for the engraving process can be shortened.

  The pulse width of the pulsed ultraviolet laser used in the present invention is preferably 1 femtosecond or more and 200 nanoseconds or less. A more preferable range is 10 femtoseconds or more and 100 nanoseconds or less, and further preferably 10 femtoseconds or more and 30 nanoseconds or less. If the pulse width is 1 femtosecond or more and 200 nanoseconds or less, a high peak output can be obtained even if the average output of the laser is small. Since the object can be easily engraved and has the effect of suppressing the influence of heat, the resulting pattern has an excellent shape. As a method for obtaining femtosecond and picosecond pulses, it is preferable to use a mode lock technique. As a method for obtaining a short pulse with a large peak output, a laser having a Q switch is preferable.

  The average output of the pulsed ultraviolet laser of the present invention is 0.01 W or more and less than 5 W. Preferably they are 0.05W or more and 2W or less, More preferably, they are 0.05W or more and 1W or less, More preferably, they are 0.1W or more and 0.5W or less. If the average output is 0.01 W or more and less than 5 W, the cured photosensitive resin can be easily laser engraved, and the edge shape of the resulting pattern becomes clear. In addition, a concave pattern having a width substantially equal to the laser beam diameter can be obtained without being affected by heat and without being excessively melted or removed.

  The amount of energy per pulse of the pulse oscillation ultraviolet laser is preferably 10 J or more and 50 kJ or less. A more preferable range is 20 J or more and 30 kJ or less, and further preferably 100 J or more and 10 kJ or less. If the energy amount per pulse is 10 J or more and 50 kJ or less, the photosensitive resin cured product can be easily laser engraved, and the edge shape of the resulting pattern becomes clear. In addition, a concave pattern having a width substantially equal to the laser beam diameter can be obtained without being affected by heat and without being excessively melted or removed. The energy amount per pulse is defined as a value obtained by dividing the average output by the repetition frequency and further dividing by the pulse width (time width of one pulse). The larger this value is, the larger the amount of energy per pulse is, which means that the head output is large.

  In the present invention, the diameter of the laser beam output from the pulsed ultraviolet laser is condensed to 0.4 μm or more and less than 15 μm, and the condensed beam is irradiated onto the surface of the resin printing original plate made of the photosensitive resin cured product. Thus, a fine concave pattern having a width of 0.4 μm or more and less than 20 μm and a depth of 1 μm or more and less than 100 μm is formed. The depth of the cured photosensitive resin engraved with one pulse of a pulsed ultraviolet laser is preferably 0.05 μm or more and 10 μm or less. If the depth of the cured photosensitive resin engraved with one pulse is in the range of 0.05 μm or more and 10 μm or less, a concave pattern having the same size as the diameter of the laser beam can be formed. Further, by using a pulse oscillation ultraviolet laser having a high repetition frequency, it is possible to engrave the same place deeply with a plurality of pulses. In order to condense the laser beam, it is preferable to use a condensing lens. In particular, when a laser beam is scanned with a galvano mirror to a relatively wide width or region in a single-axis or bi-axial direction, a large fθ lens is preferably used. In the case of a laser having an oscillation wavelength of 300 nm or more and 400 nm or less, it is not necessary to change the material of the fθ lens to be used to a hard and expensive material such as quartz, so that the lens surface can be easily polished and can be obtained at low cost. There are also advantages. In the present invention, since the material to be irradiated with the laser beam is a cured photosensitive resin, it is possible to form a concave pattern having a width substantially equal to the diameter of the irradiated beam by using a laser having a low average output. .

Since the laser beam of the pulsed ultraviolet laser used in the present invention is focused on an extremely small spot, the laser beam before focusing is preferably single mode oscillation, that is, TEM ₀₀ mode oscillation. Furthermore, it is preferable that the M ² value, which is an index representing the quality of the laser transverse mode, is 1 or more and 2 or less. A more preferable range is 1 or more and 1.5 or less. The resin printing original plate used in the present invention comprises a photosensitive resin cured product, which is formed by photocuring a liquid photosensitive resin composition at 20 ° C. It preferably has at least one type of bond selected from a bond and an ester bond, and has at least one type of bond selected from a urethane bond, a urea bond, and an amide bond. When the photosensitive resin cured product has these bonds, a printing substrate having good laser engraving properties, mechanical properties, and solvent resistance can be obtained. The photosensitive resin composition preferably includes a resin (a) which is a polymer compound, an organic compound (b) having a polymerizable unsaturated group in the molecule, and a photopolymerization initiator.

  The resin (a) is preferably a compound having a number average molecular weight of 1000 or more and 300,000 or less. A more preferable range of the number average molecular weight of the resin (a) is 2000 or more and 100,000 or less, and a more preferable range is 5000 or more and 50,000 or less. If the number average molecular weight of the resin (a) is 1000 or more, the printing original plate produced by crosslinking later maintains strength, and the relief image produced from this original plate is strong, and when used as a printing plate, it can be used repeatedly. I can bear it. Further, if the number average molecular weight of the resin (a) is 300,000 or less, the viscosity at the time of molding of the photosensitive resin composition does not increase excessively, and a sheet-shaped or cylindrical laser engraving printing original plate is prepared. Can be produced. The number average molecular weight referred to here is a value measured by gel permeation chromatography, calibrated with polystyrene having a known molecular weight, and converted.

  The resin (a) may be a compound having a polymerizable unsaturated group in the molecule. The definition of “polymerizable unsaturated group” in the present invention is a polymerizable unsaturated group involved in a radical or addition polymerization reaction. Preferable examples of the polymerizable unsaturated group involved in the radical polymerization reaction include a vinyl group, an acetylene group, an acrylic group, and a methacryl group. Preferred examples of the polymerizable unsaturated group involved in the addition polymerization reaction include cinnamoyl group, thiol group, azide group, epoxy group that undergoes ring-opening addition reaction, oxetane group, cyclic ester group, dioxirane group, spiroorthocarbonate group, spiro An ortho ester group, a bicyclo ortho ester group, a cyclic imino ether group and the like can be mentioned. A particularly preferred resin (a) is a polymer having an average of 0.7 or more polymerizable unsaturated groups per molecule. An amount exceeding 1 is more preferred. If the average is 0.7 or more per molecule, the printing original plate obtained from the resin composition is excellent in mechanical strength, and the relief shape is difficult to collapse during laser engraving. Furthermore, its durability is also good, and it can withstand repeated use. In the resin (a), the position of the polymerizable unsaturated group is preferably directly bonded to the end of the polymer main chain, the end of the polymer side chain, the polymer main chain, or the side chain. The average number of polymerizable unsaturated groups contained in one molecule of the resin (a) can be obtained by a molecular structure analysis method using a nuclear magnetic resonance spectrum method (NMR method).

  As the resin (a), a compound having a polymerizable unsaturated group in the molecular main chain, molecular terminal or side chain may be used. In particular, as a method for introducing a polymerizable unsaturated group at the molecular terminal, a hydroxyl group, an amino group, an epoxy group, a carboxyl group, an acid anhydride group, a ketone group, a hydrazine residue, an isocyanate group, an isothiocyanate group, a cyclic carbonate group, an alkoxy group A molecular weight obtained by reacting a binder having a plurality of groups capable of binding to the reactive group having a molecular weight of about several thousand having a plurality of reactive groups such as a carbonyl group (for example, polyisocyanate in the case of a hydroxyl group or an amino group). After adjusting the amount and converting to a terminal binding group, a polymerizable unsaturated group is introduced at the terminal by reacting with a terminal reactive group and an organic compound having a polymerizable unsaturated group. A method such as a method is preferred.

  The resin (a) used is preferably a resin that is easily liquefied or easily decomposed during laser engraving. Examples of resins that are easily decomposed include styrene, α-methylstyrene, α-methoxystyrene, acrylic esters, methacrylic esters, ester compounds, ether compounds, nitro compounds, and carbonates as monomer units that are easily decomposed in the molecular chain. Preferably, compounds, carbamoyl compounds, hemiacetal ester compounds, oxyethylene compounds, aliphatic cyclic compounds, and the like are included. Especially polyethers such as polyethylene glycol, polypropylene glycol, polytetraethylene glycol, aliphatic polycarbonates, aliphatic carbamates, polymethyl methacrylate, polystyrene, nitrocellulose, polyoxyethylene, polynorbornene, polycyclohexadiene hydrogenated product Alternatively, a polymer having a molecular structure such as a dendrimer having many branched structures is a representative example of those that are easily decomposed. A polymer containing a large number of oxygen atoms in the molecular chain is preferred from the viewpoint of degradability. Among these, a compound having a carbonate group, a carbamate group, and a methacryl group in the polymer main chain is preferable because of its high thermal decomposability. For example, polyesters and polyurethanes synthesized from (poly) carbonate diol or (poly) carbonate dicarboxylic acid as raw materials, polyamides synthesized from (poly) carbonate diamine as raw materials, and the like can be cited as examples of polymers having good thermal decomposability. . These polymer main chains and side chains may contain a polymerizable unsaturated group. In particular, when a reactive functional group such as a hydroxyl group, an amino group, or a carboxyl group is present at the terminal, it is easy to introduce a polymerizable unsaturated group at the terminal of the main chain. In particular, a compound having at least one type of bond selected from carbonate bond and ester bond in the molecule and at least one type of bond selected from urethane bond, urea bond and amide bond is preferable. By using these compounds, it is possible to obtain a cured photosensitive resin having high laser engraving properties and mechanical properties.

  Examples of the resin (a) include compounds having a polymerizable unsaturated group in the molecular main chain or side chain, such as polydienes such as polybutadiene and polyisoprene. In addition, a polymer compound having a polymerizable unsaturated group introduced into the molecule by a chemical reaction such as a substitution reaction, elimination reaction, condensation reaction, or addition reaction using a polymer compound having no polymerizable unsaturated group as a starting material. It can also be mentioned. Examples of polymer compounds having no polymerizable unsaturated groups include polyolefins such as polyethylene and polypropylene, polyhaloolefins such as polyvinyl chloride and polyvinylidene chloride, polystyrene, polyacrylonitrile, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, poly In addition to CC chain polymers such as acrylic acid, poly (meth) acrylic esters, poly (meth) acrylamide, and polyvinyl ether, polyethers such as polyphenylene ether, polythioethers such as polyphenylene thioether, and polyesters such as polyethylene terephthalate , Polycarbonate, polyacetal, polyurethane, polyamide, polyurea, polyimide, polydialkylsiloxane and other polymer compounds, or the main chain of these polymer compounds It may be mentioned a polymer compound having a hetero atom, a random copolymer synthesized from a plurality of types of monomer components, a block copolymer. Furthermore, it is possible to use a mixture of a plurality of polymer compounds having a polymerizable unsaturated group introduced in the molecule.

  In particular, when a flexible relief image is required as in flexographic printing plate applications, the resin (a) is preferably a liquid resin having a glass transition temperature of 20 ° C. or lower, and a liquid resin having a glass transition temperature of 0 ° C. or lower. It is more preferable to use Examples of such a liquid resin include hydrocarbons such as polyethylene, polybutadiene, hydrogenated polybutadiene, polyisoprene, and hydrogenated poisoprene, polyesters such as adipate and polycaprolactone, and polymers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Synthesized by using ethers, aliphatic polycarbonates, silicones such as polydimethylsiloxane, polymers of (meth) acrylic acid and / or derivatives thereof, and mixtures and copolymers thereof. The compound which has can be used. The content is preferably 30 wt% or more based on the entire resin (a). In particular, unsaturated polyurethanes having a polycarbonate structure are preferred from the viewpoint of weather resistance.

  The liquid resin here means a polymer that has the property of being easily deformed by flow and solidified into a deformed shape by cooling. When an external force is applied, the liquid resin is instantly deformed according to the external force. When the external force is removed, the term corresponds to an elastomer having a property of restoring the original shape in a short time. When the resin (a) is a liquid resin at 20 ° C., the photosensitive resin composition is also liquid at 20 ° C. The photosensitive resin composition of the present invention capable of obtaining good thickness accuracy and dimensional accuracy when the relief image forming original plate obtained from this is formed into a sheet or cylinder, preferably has a viscosity at 20 ° C. It is 10 Pa · s or more and 10 kPa · s or less. More preferably, it is 50 Pa · s or more and 5 kPa · s or less. If the viscosity is 10 Pa · s or more, the mechanical strength of the produced printing original plate is sufficient, and the shape can be easily maintained and processed even when it is formed into a cylindrical printing original plate. If the viscosity is 10 kPa · s or less, it is easily deformed even at room temperature and easy to process. It is easy to form into a sheet or cylindrical printing original, and the process is simple. In particular, in order to obtain a cylindrical printing original plate with high plate thickness accuracy, when the liquid photosensitive resin layer is formed on the cylindrical support, the photosensitive resin composition does not cause a phenomenon such as liquid dripping due to gravity. Thus, the viscosity is preferably 100 Pa · s or more, more preferably 200 Pa · s or more, and still more preferably 500 Pa · s or more. Moreover, when the photosensitive resin composition used by this invention is a liquid especially in 20 degreeC, it is preferable to have thixotropic property. In particular, when the photosensitive resin composition layer is formed on a cylindrical support, a predetermined thickness can be maintained without causing dripping due to gravity.

  The organic compound (b) is a compound having a polymerizable unsaturated group having a number average molecular weight of less than 1000. The number average molecular weight is preferably 1000 or less because of easy dilution with the resin (a). The definition of a polymerizable unsaturated group is a polymerizable unsaturated group that participates in a radical or addition polymerization reaction as described in the section of the resin (a). Preferable examples of the polymerizable unsaturated group involved in the radical polymerization reaction include a vinyl group, an acetylene group, an acrylic group, and a methacryl group. Preferred examples of the polymerizable unsaturated group involved in the addition polymerization reaction include cinnamoyl group, thiol group, azide group, epoxy group that undergoes ring-opening addition reaction, oxetane group, cyclic ester group, dioxirane group, spiroorthocarbonate group, spiro An ortho ester group, a bicyclo ortho ester group, a cyclic imino ether group and the like can be mentioned.

  Specific examples of the organic compound (b) include radical reactive compounds such as olefins such as ethylene, propylene, styrene and divinylbenzene, acetylenes, (meth) acrylic acid and derivatives thereof, haloolefins, acrylonitrile and the like. Saturated nitriles, (meth) acrylamide and derivatives thereof, aryl compounds such as aryl alcohol and aryl isocyanate, unsaturated dicarboxylic acids such as maleic anhydride, maleic acid and fumaric acid and derivatives thereof, vinyl acetates, N-vinylpyrrolidone, N-vinyl carbazole and the like can be mentioned, and (meth) acrylic acid and derivatives thereof are preferable examples from the viewpoints of the abundance of the types, price, decomposability upon laser light irradiation, and the like. Examples of the derivatives of the compounds include compounds having an alicyclic skeleton such as cycloalkyl-, bicycloalkyl-, cycloalkene-, and bicycloalkene-, and aromatic skeletons such as benzyl-, phenyl-, phenoxy-, and fluorene-. A compound having an alkyl group, a halogenated alkyl group, an alkoxyalkyl group, a hydroxyalkyl group, an aminoalkyl group, a compound having a glycidyl group, an alkylene glycol, a polyoxyalkylene glycol, a polyalkylene glycol- or a polyvalent such as trimethylolpropane Examples thereof include ester compounds with alcohols, compounds having a polysiloxane structure such as polydimethylsiloxane and polydiethylsiloxane. Moreover, you may be a heteroaromatic compound containing elements, such as nitrogen and sulfur.

  In addition, compounds having an epoxy group that undergoes an addition polymerization reaction include compounds obtained by reacting various diols and polyols such as triol with epichlorohydrin, epoxy compounds obtained by reacting peroxy acids with ethylene bonds in the molecule, and the like. Can be mentioned. Specifically, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene Glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A diglycidyl ether, hydrogenated bisphenol A Diglycidyl ether, bisphenol A Diglycidyl ether, polytetramethylene glycol diglycidyl ether, poly (propylene glycol adipate) diol diglycidyl ether, poly (ethylene glycol adipate) diol diglycidyl ether, poly (caprolactone) diol di of compounds with addition of lenoxide or propylene oxide Examples thereof include epoxy compounds such as glycidyl ether and epoxy-modified silicone oil (trade name “HF-105” manufactured by Shin-Etsu Chemical Co., Ltd.).

In this invention, the organic compound (b) which has these polymerizable unsaturated groups can select the 1 type (s) or 2 or more types according to the objective. For example, when used as a printing plate, it has at least one long-chain aliphatic, alicyclic or aromatic derivative as an organic compound used to suppress swelling with respect to an organic solvent such as alcohol or ester which is a solvent for printing ink. Is preferred.
In order to increase the mechanical strength of the printing original plate obtained from the resin composition used in the present invention, the organic compound (b) preferably has at least one alicyclic or aromatic derivative. It is preferably 20 wt% or more of the total amount of the organic compound (b), more preferably 50 wt% or more. The aromatic derivative may be an aromatic compound having an element such as nitrogen or sulfur.

In order to increase the rebound resilience of the printing plate, for example, a methacrylic monomer as described in JP-A-7-239548 can be used, or it can be selected using the technical knowledge of known photosensitive resins for printing.
Hydrogen atom in which resin (a) or organic compound (b) is directly bonded to a sulfur atom such as thiol, a compound having a hydrogen atom that is in the α position with respect to an oxygen atom or nitrogen atom present in the molecular chain It is preferable to contain at least 20 wt% or more of the compound having a weight of the total amount of the photosensitive resin composition. More preferably, it is 40 wt% or more. Examples of the atomic group derived from the oxygen atom include alcohols, ethers, esters, and carbonates, and examples of the atomic group derived from the nitrogen atom include urethane, urea, and amide.

  The photosensitive resin composition of the present invention is crosslinked by irradiation with light or an electron beam to develop physical properties as a printing plate, and a photopolymerization initiator can be added at that time. The photopolymerization initiator can be selected from commonly used ones. For example, radical polymerization, cationic polymerization, and anion polymerization illustrated in “Polymer Data Handbook-Fundamentals” edited by the Society of Polymer Sciences, published in 1986 by Fufukan. An agent can be used. In addition, crosslinking by photopolymerization using a photopolymerization initiator is useful as a method for producing a printing original plate with good productivity while maintaining the storage stability of the resin composition of the present invention, and is used in that case. Known initiators can also be used. As a photopolymerization initiator for inducing a radical polymerization reaction, a hydrogen abstraction type photopolymerization initiator (d) and a decay type photopolymerization initiator (e) are used as particularly effective photopolymerization initiators.

  Although it does not specifically limit as a hydrogen abstraction type photoinitiator (d), It is preferable to use an aromatic ketone. Aromatic ketone is efficiently converted into an excited triplet state by photoexcitation, and a chemical reaction mechanism has been proposed in which this excited triplet state generates a radical by extracting hydrogen from the surrounding medium. The generated radical is considered to be involved in the photocrosslinking reaction. Any compound can be used as the hydrogen abstraction type photopolymerization initiator (d) used in the present invention as long as it is a compound that generates radicals by extracting hydrogen from the surrounding medium through an excited triplet state. Examples of aromatic ketones include benzophenones, Michler ketones, xanthenes, thioxanthones, and anthraquinones, and it is preferable to use at least one compound selected from these groups. Benzophenones refer to benzophenone or derivatives thereof, and specifically include 3,3 ', 4,4'-benzophenone tetracarboxylic acid anhydride, 3,3', 4,4'-tetramethoxybenzophenone, and the like. Michler ketones refer to Michler ketone and its derivatives.

  Xanthenes refer to derivatives substituted with xanthene and an alkyl group, phenyl group, or halogen group. Thioxanthones refer to thioxanthone and derivatives substituted with an alkyl group, a phenyl group, and a halogen group, and examples thereof include ethylthioxanthone, methylthioxanthone, and chlorothioxanthone. Anthraquinones are anthraquinone and derivatives substituted with alkyl groups, phenyl groups, halogen groups, and the like. The addition amount of the hydrogen abstraction type photopolymerization initiator (d) is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.5 wt% or more and 5 wt% or less of the total amount of the photosensitive resin composition. When the addition amount is within this range, when the liquid photosensitive resin composition is photocured in the air, the curability of the surface of the cured product can be sufficiently secured, and the weatherability can be secured.

  The decay-type photopolymerization initiator (e) refers to a compound that generates an active radical by generating a cleavage reaction in the molecule after light absorption, and is not particularly limited. Specific examples include benzoin alkyl ethers, 2,2-dialkoxy-2-phenylacetophenones, acetophenones, acyloxime esters, azo compounds, organic sulfur compounds, diketones, and the like. It is preferable to use at least one compound selected from the group consisting of: Examples of benzoin alkyl ethers include benzoin isopropyl ether, benzoin isobutyl ether, and compounds described in “Photosensitive polymer” (Kodansha, 1977, page 228). Examples of 2,2-dialkoxy-2-phenylacetophenones include 2,2-dimethoxy-2-phenylacetophenone and 2,2-diethoxy-2-phenylacetophenone. Examples of acetophenones include acetophenone, trichloroacetophenone, 1-hydroxycyclohexylphenylacetophenone, 2,2-diethoxyacetophenone, and the like. Examples of acyl oxime esters include 1-phenyl-1,2-propanedione-2- (o-benzoyl) oxime.

  Examples of the azo compound include azobisisobutyronitrile, diazonium compound, and tetrazene compound. Examples of the organic sulfur compound include aromatic thiol, mono- and disulfide, thiuram sulfide, dithiocarbamate, S-acyl dithiocarbamate, thiosulfonate, sulfoxide, sulfinate, and dithiocarbonate. Examples of diketones include benzyl and methylbenzoyl formate. The addition amount of the collapsible photopolymerization initiator (e) is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.3 wt% or more and 3 wt% or less of the total amount of the photosensitive resin composition. If the addition amount is within this range, when the photosensitive resin composition is photocured in the air, the curability inside the cured product can be sufficiently secured.

  A compound having a site functioning as a hydrogen abstraction type photopolymerization initiator and a site functioning as a decay type photopolymerization initiator in the same molecule can also be used as the photopolymerization initiator. There may be mentioned α-aminoacetophenones. Examples thereof include 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propan-1-one and compounds represented by the following general formula (1).

(1)


(In the formula, each R ₁ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X represents an alkylene group having 1 to 10 carbon atoms.)
The amount of the compound having a site functioning as a hydrogen abstraction type photopolymerization initiator and a site functioning as a decay type photopolymerization initiator in the same molecule is 0.1 wt% or more and 10 wt% of the total amount of the photosensitive resin composition. The following is preferable, and more preferably 0.3 wt% or more and 3 wt% or less. When the addition amount is within this range, the mechanical properties of the cured product can be sufficiently ensured even when the photosensitive resin composition is photocured in the atmosphere.

A photopolymerization initiator that induces an addition polymerization reaction by absorbing light and generating an acid can also be used. For example, photocationic polymerization initiators such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, or polymerization initiators that absorb light and generate bases. The addition amount of these photopolymerization initiators is preferably in the range of 0.1 wt% to 10 wt% of the total amount of the photosensitive resin composition.
It is preferable to add an inorganic porous material (f) to the photosensitive resin composition. The inorganic porous material (f) is an inorganic particle having fine pores or fine voids in the particle, and is added to absorb and remove viscous liquid residue generated in a large amount in laser engraving. It is an agent and has an effect of preventing tackiness of the plate surface. The inorganic porous material of the present invention is added for the purpose of removing viscous liquid waste, and the number average particle size, specific surface area, average pore size, pore volume, and loss on ignition greatly affect its performance. To do.

  The inorganic porous body (f) preferably has a number average particle diameter of 0.1 to 100 μm. When the number average particle size is used, the engraving apparatus is less likely to be polluted when the original plate obtained from the resin composition used in the present invention is engraved with a laser. ) And the organic compound (b), the viscosity is not extremely increased and the entrainment of bubbles can be suppressed. In addition, when laser engraving is performed, the relief image is hardly damaged, and the fineness of the printed matter can be ensured. A more preferable range of the average particle diameter is 0.5 to 20 μm, and a further preferable range is 3 to 10 μm. The average particle size of the inorganic porous material is a value measured using a laser scattering type particle size distribution measuring device.

The range of the specific surface area of the inorganic porous body (f) is preferably 10 m ² / g or more and 1500 m ² / g or less. A more preferable range is 100 m ² / g or more and 800 m ² / g or less. When the specific surface area is 10 m ² / g or more, removal of the liquid residue during laser engraving is sufficient, and when the specific surface area is 1500 m ² / g or less, an increase in the viscosity of the photosensitive resin composition is suppressed, and thixotropic properties are obtained. Can be suppressed. The specific surface area is determined from the nitrogen adsorption isotherm at −196 ° C. based on the BET equation.

  The average pore diameter of the inorganic porous material (f) greatly affects the amount of liquid residue absorbed during laser engraving. A preferable range of the average pore diameter is 1 nm to 1000 nm, more preferably 2 nm to 200 nm, and still more preferably 2 nm to 50 nm. If the average pore diameter is 1 nm or more, the absorbability of liquid debris generated during laser engraving can be ensured, and if it is 1000 nm or less, the specific surface area of the particles is large and the amount of liquid debris absorbed can be sufficiently ensured. When the average pore diameter is less than 1 nm, the reason why the amount of absorbed liquid debris is small is not clear, but because liquid debris is viscous, it is estimated that it is difficult to enter the micropores and the amount of absorption is small. is doing.

The average pore diameter is a value measured using a nitrogen adsorption method. Those having an average pore diameter of 2 to 50 nm are particularly called mesopores, and the ability of porous particles having mesopores to absorb liquid waste is extremely high. The pore size distribution is obtained from an adsorption isotherm of nitrogen at −196 ° C.
The pore volume of the inorganic porous material (f) is preferably 0.1 ml / g or more and 10 ml / g or less, more preferably 0.2 ml / g or more and 5 ml / g or less. When the pore volume is 0.1 ml / g or more, the amount of viscous liquid residue absorbed is sufficient, and when the pore volume is 10 ml / g or less, the mechanical strength of the particles can be ensured. A nitrogen adsorption method is used to measure the pore volume. The pore volume is determined from an adsorption isotherm of nitrogen at −196 ° C.

There is an oil absorption amount as an index for evaluating the liquid residue adsorption amount. This is defined by the amount of oil absorbed by 100 g of the inorganic porous body. A preferred range of the oil absorption amount of the inorganic porous material used in the present invention is 10 ml / 100 g or more and 2000 ml / 100 g or less, and a more preferred range is 50 ml / 100 g or more and 1000 ml / 100 g or less. If the oil absorption is 10 ml / 100 g or more, removal of the liquid residue generated during laser engraving is sufficient, and if it is 2000 ml / 100 g or less, the mechanical strength of the inorganic porous body can be sufficiently secured. The oil absorption can be measured according to JIS-K5101.
The inorganic porous body (f) preferably retains its porosity without being deformed or melted by irradiation with laser light in the infrared wavelength region. The loss on ignition when treated at 950 ° C. for 2 hours is preferably 15 wt% or less, more preferably 10 wt% or less.

The particle shape of the inorganic porous material of the present invention is not particularly limited, and spherical, flat, needle-like, amorphous, or particles having protrusions on the surface can be used. In particular, spherical particles are preferable from the viewpoint of wear resistance. It is also possible to use particles having hollow inside particles, spherical granules having a uniform pore diameter such as silica sponge, and the like. Although it does not specifically limit, For example, porous silica, mesoporous silica, silica-zirconia porous gel, porous alumina, porous glass, etc. can be mentioned. Moreover, since the pore diameter cannot be defined for a layer having a gap of several to 100 nm such as a layered clay compound, in the present invention, the gap between the layers is defined as the pore diameter.
Furthermore, organic pigments such as pigments and dyes that absorb light of the wavelength of the laser beam can be incorporated into these pores or voids.

Sphericality is defined as an index that defines spherical particles. The sphericity used in the present invention is the ratio (D ₁ / D) of the maximum value D ₁ of the circle that completely enters the projection figure when the particle is projected to the minimum value D ₂ of the circle that completely enters the projection figure. ₂ ). In the case of a true sphere, the sphericity is 1.0. The sphericity of the preferable spherical particles used in the present invention is preferably 0.5 or more and 1.0 or less, more preferably 0.7 or more and 1.0 or less. If it is 0.5 or more, the wear resistance as a printing plate is good. The sphericity of 1.0 is an upper limit value of sphericity. As the spherical particles, it is desirable that 70% or more, more preferably 90% or more of the particles have a sphericity of 0.5 or more. As a method of measuring the sphericity, a method of measuring based on a photograph taken using a scanning electron microscope can be used. At that time, it is preferable to take a picture at a magnification at which at least 100 particles enter the monitor screen. The D ₁ and D ₂ are measured based on a photograph, but it is preferable to process the photograph using a digitizing device such as a scanner and then process the data using image analysis software.

Moreover, the surface of the inorganic porous body can be coated with a silane coupling agent, a titanium coupling agent, or other organic compounds, and subjected to a surface modification treatment to make particles more hydrophilic or hydrophobic.
The inorganic porous material (f) can be selected from one or more types, and by adding the inorganic porous material (f), the generation of liquid residue during laser engraving and the prevention of tacking of the relief printing plate, etc. Improvements are made effectively.
The ratio of the resin (a), the organic compound (b), and the inorganic porous body (f) in the photosensitive resin composition used in the present invention is usually the organic compound (b) relative to 100 parts by weight of the resin (a). ) Is preferably 5 to 200 parts by weight, more preferably 20 to 100 parts by weight. The inorganic porous material (f) is preferably 1 to 100 parts by weight, and more preferably 2 to 50 parts by weight. A more preferable range is 2 to 20 parts by weight.

When the ratio of the organic compound (b) is smaller than the above range, it tends to cause inconveniences such as difficulty in balancing the hardness and tensile strength / elongation of the printing plate to be obtained, and when it is larger than the above range, cross-linking curing is performed. There is a tendency for the shrinkage during the process to increase and the thickness accuracy to deteriorate.
When the amount of the inorganic porous material (f) is smaller than the above range, depending on the types of the resin (a) and the organic compound (b), the generation of engraving liquid debris can be suppressed when laser engraving is performed. The effect may not be sufficiently exhibited, and if it is larger than the above range, the printing plate tends to be brittle. Further, the transparency may be impaired, and particularly when used as a flexographic plate, the hardness may become too high. When a photosensitive resin composition is cured using light, particularly ultraviolet rays, to prepare a laser engraving printing original plate, light transmittance affects the curing reaction. Therefore, it is effective to use a material having a refractive index close to that of the photosensitive resin composition.

  As a method of mixing the inorganic porous material in the photosensitive resin composition, a method of directly adding the inorganic porous material (f) in a state where the thermoplastic resin is heated and fluidized, or photopolymerization with the thermoplastic resin. Any method may be used in which the inorganic porous material (f) is added to the kneaded organic organic compound (b) first.

In addition, a polymerization inhibitor, an ultraviolet absorber, a dye, a pigment, a lubricant, a surfactant, a plasticizer, a fragrance and the like can be added to the resin composition used in the present invention according to the purpose and purpose.
In the printing original plate capable of laser engraving used in the present invention, the polymerizable unsaturated groups of the organic compound (b) react with each other, or the polymerizable unsaturated group of the resin (a) reacts with the polymerizable unsaturated group of the organic compound (b). As a result, a three-dimensional crosslinked structure is formed and insolubilized in a commonly used ester-based, ketone-based, aromatic-based, ether-based, alcohol-based or halogen-based solvent. This reaction occurs between the organic compounds (b), between the resins (a), or between the resin (a) and the organic compound (b), and the polymerizable unsaturated group is consumed. In addition, when the photopolymerization initiator is used for crosslinking and curing, the photopolymerization initiator is decomposed by light. Therefore, the cross-linked cured product is extracted with a solvent, and mass-separated by GC-MS (gas chromatography). Analysis method), LC-MS method (method for mass spectrometry of those separated by liquid chromatography), GPC-MS method (method for separation and mass spectrometry by gel permeation chromatography), LC-NMR method (liquid chromatography) By analyzing using the method of analyzing the product separated in (1) by nuclear magnetic resonance spectrum, unreacted photopolymerization initiator and decomposition products can be identified. Furthermore, by using the GPC-MS method, LC-MS method, and GPC-NMR method, the unreacted polymer, the unreacted organic compound (b), and the polymerizable unsaturated group in the solvent extract are reacted. The resulting relatively low molecular weight product can also be identified from analysis of the solvent extract.

  For the high molecular weight component insoluble in the solvent in which the three-dimensional cross-linked structure is formed, by using the pyrolysis GC-MS method, the site formed by the reaction of the polymerizable unsaturated group is formed as a component constituting the high molecular weight body. It is possible to verify whether it exists. For example, it can be estimated from the mass spectrometry spectrum pattern that there is a site where a polymerizable unsaturated group such as a methacrylate group, an acrylate group, or a vinyl group has reacted. The pyrolysis GC-MS method is a method in which a sample is thermally decomposed and a generated gas component is separated by gas chromatography and then mass spectrometry is performed. The decomposition product derived from the photopolymerization initiator and the unreacted photopolymerization initiator are detected together with the unreacted polymerizable unsaturated group or the site obtained by the reaction of the polymerizable unsaturated group in the crosslinked cured product. Then, it can be concluded that the photosensitive resin composition was obtained by photocrosslinking and curing.

  Further, the amount of the inorganic porous fine particles present in the crosslinked cured product can be obtained by heating the crosslinked cured product in the air to burn off the organic component and measuring the weight of the residue. In addition, the presence of inorganic porous fine particles in the residue is due to morphological observation with a field emission type high resolution scanning electron microscope, particle size distribution with a laser scattering type particle size distribution measuring device, and nitrogen adsorption method. It can be identified from the measurement of pore volume, pore diameter distribution and specific surface area.

  An existing resin molding method can be used as a method for molding the resin composition used in the present invention into a sheet or cylinder. For example, a casting method, a method of extruding a resin from a nozzle or a die with a machine such as a pump or an extruder, adjusting the thickness with a blade, and adjusting the thickness by calendering with a roll can be exemplified. In that case, it is also possible to perform the molding while heating within a range that does not deteriorate the performance of the resin. Moreover, you may perform a rolling process, a grinding process, etc. as needed. Usually, it is often formed on a sheet-like support made of a material such as PET or nickel, but it may be formed directly on a cylinder of a printing press. Further, a cylindrical support made of fiber reinforced plastic (FRP), plastic, or metal can also be used. The cylindrical support can be hollow with a constant thickness for weight reduction. The role of the sheet-like support or the cylindrical support is to ensure the dimensional stability of the printing original plate.

  Therefore, it is necessary to select one having high dimensional stability. When evaluated using the linear thermal expansion coefficient, the upper limit value of a preferable material is 100 ppm / ° C. or less, more preferably 70 ppm / ° C. or less. Specific examples of materials include polyester resin, polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, polybismaleimide resin, polysulfone resin, polycarbonate resin, polyphenylene ether resin, polyphenylene thioether resin, polyethersulfone resin, all Examples thereof include liquid crystal resins composed of aromatic polyester resins, wholly aromatic polyamide resins, and epoxy resins. Further, these resins can be laminated and used.

  For example, a sheet or the like in which layers of polyethylene terephthalate having a thickness of 50 μm are laminated on both surfaces of a 4.5 μm thick wholly aromatic polyamide film may be used. In addition, a porous sheet, for example, a cloth formed by knitting fibers, a nonwoven fabric, or a film in which pores are formed can be used as a sheet-like support or a cylindrical support. When a porous sheet or a porous cylinder is used as a sheet-like support or a cylindrical support, the photosensitive resin cured product layer and the sheet form are obtained by photocuring after impregnating the photosensitive resin composition into the holes. Since the support or the cylindrical support is integrated, high adhesiveness can be obtained. The fibers forming the cloth or nonwoven fabric include glass fibers, alumina fibers, carbon fibers, alumina / silica fibers, boron fibers, high silicon fibers, potassium titanate fibers, inorganic fibers such as sapphire fibers, natural materials such as cotton and hemp Examples thereof include semi-synthetic fibers such as fibers, rayon and acetate, and synthetic fibers such as nylon, polyester, acrylic, vinylon, polyvinyl chloride, polyolefin, polyurethane, polyimide, and aramid. Further, cellulose produced by bacteria is a highly crystalline nanofiber, and is a material capable of producing a thin nonwoven fabric with high dimensional stability.

  In addition, as a method of reducing the linear thermal expansion coefficient of a sheet-like support or cylindrical support, a method of adding a filler, a method of impregnating or coating a resin on a mesh cloth such as wholly aromatic polyamide, or a glass cloth And so on. As the filler, generally used organic fine particles, inorganic fine particles such as metal oxide or metal, organic / inorganic composite fine particles, and the like can be used. In addition, porous fine particles, fine particles having cavities inside, microcapsule particles, and layered compound particles in which a low molecular compound intercalates can be used. In particular, metal oxide fine particles such as alumina, silica, titanium oxide, and zeolite, latex fine particles made of polystyrene / polybutadiene copolymer, natural product-based organic fine particles such as highly crystalline cellulose, and the like are useful.

  By performing physical and chemical treatment on the surface of the sheet-like support or cylindrical support used in the present invention, the adhesiveness with the photosensitive resin composition layer or the adhesive layer can be improved. Examples of the physical treatment method include a sand blast method, a wet blast method for injecting a liquid containing fine particles, a corona discharge treatment method, a plasma treatment method, an ultraviolet ray or vacuum ultraviolet ray irradiation method, and the like. The chemical treatment method includes a strong acid / strong alkali treatment method, an oxidant treatment method, a coupling agent treatment method, and the like.

  The molded photosensitive resin composition layer is crosslinked by light irradiation to form a printing original plate. Further, it can be crosslinked by light irradiation while molding. Examples of the light source used for curing include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a germicidal lamp, a carbon arc lamp, a xenon lamp, and a metal halide lamp. The light applied to the photosensitive resin composition layer preferably has a wavelength of 200 nm to 300 nm. In particular, many hydrogen abstraction type photopolymerization initiators (d) have strong light absorption in this wavelength region. Therefore, when they have light with a wavelength of 200 nm to 300 nm, the curability of the surface of the cured photosensitive resin layer is sufficient. Can be secured. Although the light source used for curing may be one type, the curability of the resin may be improved by curing using two or more types of light sources having different wavelengths, so two or more types of light sources may be used. There is no problem.

The thickness of the original plate used for laser engraving may be arbitrarily set according to the purpose of use, but is generally in the range of 0.1 to 7 mm when used as a printing plate. In some cases, a plurality of materials having different compositions may be stacked.
In the present invention, a cushion layer made of an elastomer can be formed below the layer to be laser engraved. In general, since the thickness of the layer to be laser engraved is 0.1 to several mm, the other lower layers may be made of materials having different compositions. The cushion layer is preferably an elastomer layer having a Shore A hardness of 20 to 70 degrees. When the Shore A hardness is 20 degrees or more, the printing quality can be ensured because the film is appropriately deformed. Moreover, if it is 70 degrees or less, it can play the role as a cushion layer. A more preferable range of Shore A hardness is 30 to 60 degrees.

The cushion layer is not particularly limited, and any cushion layer may be used as long as it has rubber elasticity, such as a thermoplastic elastomer, a photocurable elastomer, and a thermosetting elastomer. It may be a porous elastomer layer having nanometer-level micropores. In particular, from the viewpoint of processability to a sheet-like or cylindrical printing plate, it is convenient and preferable to use a liquid photosensitive resin composition that is cured by light and to use a material that becomes elastomer after curing.
Specific examples of the thermoplastic elastomer used for the cushion layer include SBS (polystyrene-polybutadiene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene), SEBS (polystyrene-polyethylene / polybutylene-polystyrene), which are styrenic thermoplastic elastomers, and the like. Olefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, ester-based thermoplastic elastomer, amide-based thermoplastic elastomer, silicon-based thermoplastic elastomer, fluorine-based thermoplastic elastomer, and the like.

Examples of the photocurable elastomer include those obtained by mixing a photopolymerizable monomer, a plasticizer, a photopolymerization initiator, and the like with the thermoplastic elastomer, and a liquid composition obtained by mixing a photopolymerizable monomer, a photopolymerization initiator, etc. with a plastomer resin. Can be mentioned. Unlike the design concept of the photosensitive resin composition, in which the function of forming a fine pattern is an important factor, there is no need to form a fine pattern using light, and a certain degree of mechanical strength can be achieved by curing by full exposure. Since it is sufficient to ensure the strength, the degree of freedom in selecting the material is extremely high.
Moreover, non-sulfur cross-linked rubbers such as sulfur cross-linked rubber, organic peroxide, phenol resin initial condensate, quinone dioxime, metal oxide, and thiourea can also be used.

Furthermore, it is also possible to use a three-dimensionally crosslinked elastomer obtained by using a curing agent that reacts with a telechelic liquid rubber.
In the case of multilayering, the position of the back film is below the cushion layer, that is, at the bottom of the printing original plate, or between the laser-engravable photosensitive resin layer and the cushion layer, that is, at the central portion of the printing original plate, Any position is acceptable.
Further, by forming a modified layer on the surface of the laser engraving printing plate, it is possible to reduce the tack of the printing plate surface and improve the ink wettability. Examples of the modified layer include a film treated with a compound that reacts with a surface hydroxyl group such as a silane coupling agent or a titanium coupling agent, or a polymer film containing porous inorganic particles.

  A widely used silane coupling agent is a compound having in its molecule a functional group highly reactive with the surface hydroxyl group of the substrate. Examples of such a functional group include a trimethoxysilyl group and a triethoxysilyl group. Group, trichlorosilyl group, diethoxysilyl group, dimethoxysilyl group, dimonochlorosilyl group, monoethoxysilyl group, monomethoxysilyl group, monochlorosilyl group. Further, at least one of these functional groups exists in the molecule, and is immobilized on the surface of the base material by reacting with the surface hydroxyl group of the base material. Further, the compound constituting the silane coupling agent of the present invention is selected from acryloyl group, methacryloyl group, active hydrogen-containing amino group, epoxy group, vinyl group, perfluoroalkyl group, and mercapto group as reactive functional groups in the molecule. Those having at least one functional group or those having a long-chain alkyl group can be used.

  Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetraoctyl bis (di-tridecyl phosphite) titanate, Tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (octylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyl Dimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacryl titanate Over DOO, isopropyl tri (dioctyl sulfate) titanate, isopropyl tricumylphenyl titanate, tetraisopropyl bis (dioctyl phosphite) may include compounds such as titanates.

When the coupling agent molecule immobilized on the surface has a polymerizable reactive group in particular, it is possible to obtain a stronger coating by irradiating light, heat, or an electron beam and crosslinking after immobilization on the surface. .
The above coupling agent can be prepared by diluting with a water-alcohol or acetic acid water-alcohol mixture as necessary. The concentration of the coupling agent in the treatment liquid is preferably 0.05 to 10.0% by weight.
The coupling agent treatment method in the present invention will be described. The treatment liquid containing the coupling agent is applied to the printing original plate or the surface of the printing plate after laser engraving. The method for applying the coupling agent treatment liquid is not particularly limited, and for example, a dipping method, a spray method, a roll coating method, a brush coating method, or the like can be applied. Further, the coating treatment temperature and the coating treatment time are not particularly limited, but are preferably 5 to 60 ° C., and the treatment time is preferably 0.1 to 60 seconds. Furthermore, it is preferable to dry the treatment liquid layer on the surface of the resin plate under heating, and the heating temperature is preferably 50 to 150 ° C.
Before treating the printing plate surface with a coupling agent, a method of irradiating light in a vacuum ultraviolet region with a wavelength of 200 nm or less such as a xenon excimer lamp, or by exposing it to a high energy atmosphere such as plasma, a hydroxyl group on the printing plate surface. And the coupling agent can be immobilized at a high density.

In laser engraving, a relief image is created on an original by operating a laser device using a computer as an image to be formed as digital data.
In the present invention, a fine pattern is formed using a pulsed ultraviolet laser. When a coarser pattern exists in the same printing plate, engraving can be performed using an infrared laser having an oscillation wavelength of 5 μm or more and 20 μm or less so that engraving processing is performed in a short time. A particularly preferred infrared laser is a carbon dioxide laser. The oscillation mode of the carbon dioxide laser may be continuous oscillation or pulse oscillation. Further, it is possible to collect a laser beam diameter output from an infrared laser to 15 μm or more and less than 100 μm, and to form a rough concave pattern having a width exceeding 15 μm and a depth of 100 μm or more.

  In the present invention, when both a pulsed ultraviolet laser and an infrared laser are used, the cured photosensitive resin to be engraved has light absorption characteristics in the ultraviolet region and the infrared region, and therefore can be engraved using the same material. . The number of beams of the pulsed ultraviolet laser and the number of beams of the infrared laser are each preferably at least one. Engraving speed can be greatly improved by using a plurality of laser beams. Engraving with a pulse oscillation ultraviolet laser and engraving with an infrared laser may be performed simultaneously or separately. From the viewpoint of shortening the time required for engraving, it is preferable to carry out simultaneously. However, this is not the case when the laser beam scanning method is different in the laser engraving apparatus. For example, a pulse oscillation ultraviolet laser scans using a galvanometer mirror, whereas an infrared laser engraves without using a galvanometer mirror.

  In the laser engraving process of the present invention, in a state where the sheet-shaped printing original plate is wound around and fixed to the cylinder surface, or the cylindrical printing original plate is mounted on the cylinder, the long axis of the cylinder is fixed and rotated in the circumferential direction. It is preferable to irradiate light. As a method for irradiating the laser beam, a method in which a laser beam is run in the major axis direction of the cylinder while rotating the cylinder, or a method of scanning in the major axis direction of the cylinder using a galvano mirror is preferable. The engraving apparatus used for laser engraving is preferably an apparatus of a type that is equipped with a cylinder and engraves while rotating. This is a preferable method particularly when a cylindrical printing plate is produced.

  Since the pulsed ultraviolet laser used in the present invention has a high oscillation frequency, a scanning method using a galvanometer mirror is preferable in the laser beam scanning method. When scanning the laser beam in the long axis direction of the cylinder using a galvano mirror, after rotating the cylinder once and engraving the pattern for one round in accordance with the image data divided in the long axis direction of the cylinder, Laser engraving a pattern corresponding to all image data by repeatedly performing the series of steps including moving the galvanometer mirror in the long axis direction of the cylinder or moving the cylinder in the long axis direction Is possible.

  The laser engraving apparatus used in the present invention has a pulsed ultraviolet laser, a galvanometer mirror for scanning the laser beam in the long axis direction of the cylinder, a condensing lens for condensing the laser beam, an optical shutter or a mechanical shutter. And a mechanism for holding the long axis of the cylinder, a mechanism for rotating the held cylinder in the circumferential direction, and a mechanism for moving the galvano mirror in the long axis direction of the cylinder or a mechanism for moving the cylinder in the long axis direction. An apparatus is preferred. Further, the laser engraving apparatus has a continuous wave infrared laser and an optical shutter, or a pulsed infrared laser and an optical shutter or a mechanical shutter, a condensing lens for condensing the laser beam, and the laser beam in the longitudinal direction of the cylinder It is preferable that the apparatus has a mechanism for moving the cylinder or a mechanism for moving the cylinder in the longitudinal direction.

  The galvanometer mirror is an optical component for scanning a laser beam in a single axis direction or a biaxial direction under computer control, and is also called a galvano scanner. There are a moving coil type and a moving magnet type depending on the driving method of the mirror, and they can be used properly depending on the oscillation frequency, scanning accuracy, and scanning area of the laser used. As the optical shutter, an acousto-optic modulator (AO modulator) is preferably used.

  Laser engraving is carried out in an oxygen-containing gas, generally in the presence of air or an air stream, but can also be carried out in the presence of carbon dioxide or nitrogen gas. When gas generated during laser engraving or fine powdery residue rises, blowing air or inert gas onto the engraving portion is effective for removal. After engraving is finished, the powdery or liquid substance slightly generated on the relief printing plate surface is washed with an appropriate method such as water containing a solvent or a surfactant, or a water-based cleaning agent is irradiated by a high-pressure spray or the like. Alternatively, it may be removed using a method of irradiating high-pressure steam.

  In the present invention, after engraving to form a fine concave pattern by irradiating laser light, following the step of removing powdery or viscous liquid residue remaining on the plate surface, the surface of the printing plate on which the pattern is formed has a wavelength of 200 nm to Post-exposure by irradiating with 450 nm light can also be performed. This is an effective method for removing tack on the surface. The post-exposure may be performed in any environment such as air, inert gas atmosphere, and water. This is particularly effective when the photosensitive resin composition used contains a hydrogen abstraction type photopolymerization initiator. Furthermore, before the post-exposure step, the printing plate surface may be exposed to a treatment liquid containing a hydrogen abstraction type photopolymerization initiator. Moreover, you may expose in the state which immersed the printing plate in the process liquid containing a hydrogen abstraction type photoinitiator.

  The printing original plate of the present invention is a relief image for a printing plate, a stamp / stamp, a design roll for embossing, a relief image for patterning an insulator, a resistor, and a conductor paste used for creating an electronic component, and a reflection of an optical component. Pattern formation of functional materials such as prevention films, color filters, (near) infrared absorption filters, alignment films, underlayers, light-emitting layers, electron transport layers, sealing in the manufacture of display elements such as liquid crystal displays or organic electroluminescence displays It can be applied and used for various applications such as coating film / pattern formation of agent layers, relief images for mold materials of ceramic products, relief images for displays such as advertisements and display boards, and prototypes / mother molds of various molded products.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not restrict | limited by these.
(1) Viscosity The viscosity of the photosensitive resin composition was measured at 20 ° C. using a B type viscometer (B8H type; manufactured by Tokyo Keiki Co., Ltd., Japan).
(2) Measurement of number average molecular weight The number average molecular weight of the resin (a) was determined by conversion with polystyrene having a known molecular weight using a gel permeation chromatography method (GPC method). Using a high-speed GPC device (HLC-8020 manufactured by Tosoh Corporation, Japan) and a polystyrene-filled column (trademark: TSKgelGMMHXL; manufactured by Tosoh Corporation, Japan), the measurement was performed with tetrahydrofuran (THF). The column temperature was set to 40 ° C. As a sample to be injected into the GPC apparatus, a THF solution having a resin concentration of 1 wt% was prepared, and the injection amount was 10 μl. As the detector, for the resin (a), an ultraviolet absorption detector was used, and 254 nm light was used as monitor light.
(3) Measurement of the number of polymerizable unsaturated groups The average number of polymerizable unsaturated groups present in the molecule of the synthesized resin (a) was obtained by removing unreacted low-molecular components using liquid chromatography. Thereafter, molecular structure analysis was performed using a nuclear magnetic resonance spectrum method (NMR method).

(Production Example 1)
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is a polycarbonate diol manufactured by Asahi Kasei Corporation. After adding 30.83 g and reacting at 80 ° C. for about 3 hours, 14.83 g of 2-methacryloyloxyisocyanate was added, and further reacted for about 3 hours, and the terminal was a methacrylic group (intramolecular polymerization). A resin (A) having a number average molecular weight of about 10,000 having an average of about 2 unsaturated unsaturated groups per molecule) was produced. This resin was in the shape of a syrup at 20 ° C., flowed when an external force was applied, and did not recover its original shape even when the external force was removed.

(Production Example 2)
To a 1 L separable flask equipped with a thermometer, a stirrer, and a reflux condenser, 500 g of polytetramethylene glycol (number average molecular weight 1830, OH number 61.3) manufactured by Asahi Kasei Co., Ltd. and 52.40 g of tolylene diisocyanate were added and heated to 60 ° C. After reacting for about 3 hours under temperature, 6.2 g of 2-hydroxypropyl methacrylate and 7.9 g of polypropylene glycol monomethacrylate (Mn400) were added and reacted for another 2 hours, and then 20 g of ethanol was added for another 2 hours. Reacted. A resin (A) having a number average molecular weight of about 20000 having a terminal methacrylic group (an average of 0.5 polymerizable unsaturated groups per molecule) was produced. This resin was in the shape of a syrup at 20 ° C., flowed when an external force was applied, and did not recover its original shape even when the external force was removed.

Example 1
65 parts by weight of resin (a) as resin (a), 33 parts by weight of phenoxyethyl acrylate as organic compound (b), 1 part by weight of methylstyryl-modified silicone oil (trade name “KF-410” manufactured by Shin-Etsu Chemical Co., Ltd.), light A photosensitive resin composition (U) is prepared by mixing 0.6 parts by weight of 2,2-dimethoxy-2-phenylacetophenone as a polymerization initiator and 1 part by weight of 2,6-di-t-butylacetophenone as a polymerization inhibitor. did. The viscosity at 20 ° C. of the photosensitive resin composition (c) was 1600 Pa · s.
The produced photosensitive resin composition (c) is molded into a 0.5 mm-thick sheet on a PET film, covered with a 15 μm-thick PET cover film, and emitted from a high-pressure mercury lamp. Was irradiated from the surface where the photosensitive resin layer was exposed in air | atmosphere, and the cushion layer was obtained. The amount of energy irradiated was 4000 mJ / cm ² (value obtained by integrating the illuminance measured with a UV-35-APR filter (trademark, manufactured by Oak Manufacturing Co., Ltd.) over time).

The Shore A hardness of the cured photosensitive resin obtained by photocuring the photosensitive resin composition (c) was 40 degrees. When measuring the Shore A hardness, the PET cover film on the surface peeled off.
Moreover, 25 parts by weight of phenoxyethyl methacrylate, 19 parts by weight of polypropylene glycol monomethacrylate, 5 parts by weight of trityrolpropane triacrylate, inorganic porous material as a polymerizable monomer with respect to 100 parts by weight of the resin (ii) obtained in Production Example 2 Trademark “Pyrospher C-1504” (hereinafter abbreviated as C-1504, number average particle diameter 4.5 μm, specific surface area 520 m ² / g, average, which is a porous fine powder silica manufactured by Fuji Silysia Chemical Ltd. Pore diameter 12 nm, pore volume 1.5 ml / g, ignition loss 2.5 wt%, oil absorption 290 ml / 100 g) 5 parts by weight, 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator 0.6 parts by weight And 1 part by weight of benzophenone, 0.56-fold of 2,6-di-t-butylacetophenone as other additive A liquid photosensitive resin composition (D) was prepared at 20 ° C. by adding an amount, and used for forming a laser engraving printing plate layer. The viscosity of the liquid photosensitive resin composition (D) at 20 ° C. was 1200 Pa · s. The resulting photosensitive resin composition (D) is molded into a sheet having a thickness of 1.7 mm on a PET film, and a PET cover film having a thickness of 15 μm is coated thereon, and light emitted from a high-pressure mercury lamp. Was irradiated from the surface where the photosensitive resin layer was exposed in the atmosphere to form a laser engraving printing original plate layer. The amount of energy irradiated was 4000 mJ / cm ² (value obtained by integrating the illuminance measured with a UV-35-APR filter (trademark, manufactured by Oak Manufacturing Co., Ltd.) over time). The sheet-form printing original plate in which the laser engraving layer is laminated on the cushion layer by peeling off the PET film attached to both surfaces of the obtained laser engraving printing original layer layer and pasting it on the cushion layer via a double-sided adhesive tape Formed.

The fine pattern laser engraving uses the third harmonic of Nd: YVO ₄ laser (trade name “BL8S-355Q” manufactured by SpectraPhysics Co., Ltd.), which is an end-pumped semiconductor laser-pumped Q-switched solid-state laser, and has a beam diameter of 8 μm. Condensed with a lens. The laser oscillation frequency was 25 kHz, the pulse width was 12 nanoseconds, the average output was 0.1 W, and the energy amount per pulse was 333 J. A laser beam was fixed, a sample to be engraved (sheet-shaped printing original plate) was fixed, and an XY stage was moved to form a plurality of orthogonal line-shaped concave patterns. The M ² value indicating the quality of the beam was less than 1.3. The area where the line-shaped concave pattern is formed is 50 mm × 50 mm. In this area, 30 line-shaped concave patterns having a width of 8 μm and a length of 40 mm are engraved at equal intervals, and the width is 8 μm perpendicular to these line-shaped concave patterns. Thirty lines of 40 mm long line-shaped concave patterns were engraved at equal intervals. The XY stage driven by the stepping motor was moved at a speed of 5 mm / second. The depth of the obtained line-shaped concave pattern was 20 μm. Since the depth of 20 μm was engraved with 80 pulses, the engraving depth per pulse was 0.25 μm.

Further, a sheet-shaped printing plate having a fine concave pattern formed on the surface as described above is wound on a cylinder, and a carbon dioxide laser engraving machine (trademark: ZED-mini-1000, UK, manufactured by ZED, USA, Coherent, Inc.) A rough pattern was formed using a carbon dioxide laser with an output of 250 W. A groove pattern tapered to 70 ° having a width of 5 mm and a depth of 300 μm was formed outside a 50 mm × 50 mm region where the fine concave pattern was formed on the surface.
Further, separately, a photosensitive resin composition (D) is formed into a sheet of 100 μm thickness on a PET film, and a PET cover film of 15 μm thickness is coated thereon, and light emitted from a high pressure mercury lamp. Was irradiated from the surface where the photosensitive resin layer was exposed in the atmosphere to obtain a sample for measuring light transmittance. The amount of energy irradiated was 2000 mJ / cm ² (value obtained by integrating the illuminance measured with a UV-35-APR filter (trademark, manufactured by Oak Manufacturing Co., Ltd.) over time). Using an ultraviolet / visible / near-infrared spectrophotometer (trade name “V-570” manufactured by JASCO Corporation), it was 34% at 355 nm (laser oscillation wavelength used for fine pattern formation).

  The sheet-like printing plate on which the concave pattern is formed as described above is printed on a glass substrate using a precision printing machine with flexographic printing specifications (trademark “JSC-m4050-M” manufactured by JEOL Ltd.). It was. A white line corresponding to the concave pattern could be printed under an appropriate printing pressure.

(Example 2)
In the same manner as in Example 1, a sheet-form printing original plate was produced. The fine pattern laser engraving uses a third harmonic of an Nd: YVO ₄ laser (Spectra Physics Co., Ltd., trademark “Vangard UV350 mW”), which is an end-pumped semiconductor laser excitation mode-locked solid-state laser, with a beam diameter of 8 μm. The light was condensed with an fθ lens. The laser oscillation frequency was 80 MHz, the pulse width was 12 picoseconds, the average output was 0.35 W, and the energy amount per pulse was 365 J. The sample was fixed, and a concave pattern was formed by scanning the laser beam in the XY directions using a galvanometer mirror. The M ² value indicating the quality of the beam was less than 1.3. A line-shaped concave pattern was formed with the same design as in Example 1. The depth of the obtained concave pattern was 25 μm. The engraving depth per pulse was 0.3 μm.

(Example 3)
A photosensitive resin composition (e) was prepared by adding 2500 ppm of a phthalocyanine dye whose central metal is vanadium to the photosensitive resin composition (e) used in Example 1, and a laser engraving layer was formed. A sheet-shaped printing plate was produced in the same manner as in Example 1 except that the photosensitive resin composition (e) was used and the thickness was 0.15 mm. The light transmittance at 355 nm of a 100 μm-thick cured photosensitive resin using the photosensitive resin composition (e) was 1%.
The dimensions of the concave pattern formed using the pulsed ultraviolet laser were 12 μm in width and 10 μm in depth.

(Comparative Example 1)
A sheet-like printing plate having a concave pattern was prepared in the same manner as in Example 1 except that a pulsed solid-state laser (trade name “Thor-355-15W-LP” manufactured by Coherent Co., Ltd.) was used as the laser light source. The laser oscillation frequency was 50 Hz, the pulse width was 130 nanoseconds, and the average output was 15 W. The laser beam diameter was condensed to 8 μm with a lens. The width of the obtained concave pattern was 30 μm.

(Comparative Example 2)
Laser engraving was carried out under the same engraving conditions using the same pulsed ultraviolet laser as in Example 1 using a 1 mm thick silicone rubber sheet containing silica. Although linear traces were seen, the depth was less than 1 μm. The silicone rubber used was not a cured photosensitive resin.
When the used silicone rubber was sliced to a thickness of 100 μm and the light transmittance at 355 nm was measured, the light transmittance was less than 0.1%.

  The present invention relates to the creation of relief images for flexographic printing plates or dry offset printing by laser engraving, the formation of patterns for surface processing such as embossing, the formation of relief images for printing such as tiles, the conductors of electronic components, semiconductors, insulators, and pattern formation , Pattern formation of functional materials such as antireflection films for optical parts, color filters, (near) infrared cut filters, and alignment films, underlayers, and light emitting layers in the production of display elements such as liquid crystal displays or organic electroluminescence displays , Laser engraving printing plate suitable for coating / pattern formation of electron transport layer, sealing material layer, sheet-like or cylindrical resin-made printing substrate having fine pattern on the surface used when forming a conductor circuit board It is optimal as a manufacturing method.

Claims (12)

  The method for producing a sheet-like or cylindrical resin-made printing substrate having a concavo-convex pattern on the surface is formed by irradiating the surface of the resin printing original plate with a laser beam and removing the resin in the portion irradiated with the laser beam. A laser engraving process in which a pattern is formed, and a portion having a thickness of at least 100 μm from the surface of the resin printing original plate is made of a cured photosensitive resin having light transmittance in the ultraviolet region, and in the laser engraving process The laser light source used is a pulsed ultraviolet laser having an average output of 0.01 W or more and less than 5 W and an energy amount per pulse of 10 J or more and 50 kJ or less, and the laser beam emitted from the pulsed ultraviolet laser Condensed to a diameter of 0.4 μm to less than 15 μm, a width of 0.4 μm to less than 20 μm, and a depth of 1 μm or less A fine concave pattern of less than 100 μm can be formed on the surface of the resin printing original plate, and the light transmittance of the cured photosensitive resin prepared by separately photocuring with a thickness of 100 μm is determined by laser engraving. A method for producing a sheet-like or cylindrical resin-made printed substrate, wherein the oscillation wavelength of a pulsed ultraviolet laser used in the process is 0.1% or more and 60% or less.   The laser engraving step further includes a step of laser engraving the surface of the resin printing original plate using a continuous oscillation or pulse oscillation infrared laser, and the beam diameter of the laser beam output from the infrared laser is 15 μm or more and less than 100 μm 2. The method for producing a sheet-like or cylindrical resin-made printed substrate according to claim 1, characterized in that a rough concave pattern which is condensed and has a width exceeding 15 μm and a depth of 100 μm or more can be formed.   The sheet according to claim 1 or 2, wherein the oscillation wavelength of the pulsed ultraviolet laser is 300 nm or more and 400 nm or less, and the oscillation wavelength of the continuous wave or pulsed infrared laser is 5 µm or more and 20 µm or less. Of manufacturing a cylindrical or cylindrical resin-made printing substrate.   The number of beams of a pulsed ultraviolet laser and the number of beams of an infrared laser are each at least one, and the sheet-like or cylindrical resin-made printing substrate according to any one of claims 1 to 3 Production method.   In the laser engraving process, with the sheet-shaped printing original wrapped around the cylinder surface and fixed, or with the cylindrical printing original mounted on the cylinder, the long axis of the cylinder is fixed and rotated in the circumferential direction, 5. The method according to claim 1, further comprising a step of laser engraving by running in the long axis direction of the cylinder or scanning in the long axis direction of the cylinder using a galvano mirror. The manufacturing method of the sheet-like or cylindrical resin-made printing base material of description.   In the method of forming a concavo-convex pattern on the surface of a printing plate precursor made of resin by scanning the laser beam in the long axis direction of the cylinder using a galvanometer mirror while fixing the long axis of the cylinder and rotating it in the circumferential direction, the cylinder is rotated once. Then, after engraving the pattern for one round according to the image data divided in the long axis direction of the cylinder, the galvanometer mirror is moved in the long axis direction of the cylinder, or the cylinder is moved in the long axis direction. The method for producing a sheet-like or cylindrical resin-made printing substrate according to claim 5, wherein a pattern corresponding to all image data can be laser-engraved by repeating the series of steps. .   7. The pulse width of a pulse oscillation ultraviolet laser irradiated on the surface of a resin printing original plate is 1 femtosecond or more and 200 nanoseconds or less, and a repetition frequency is 10 Hz or more and 500 MH or less. A method for producing a sheet-like or cylindrical resin-made printing substrate according to claim 1.   8. The production of a sheet-like or cylindrical resin-made printing substrate according to claim 1, wherein the pulsed ultraviolet laser beam is a third harmonic of an end-pump type semiconductor laser-excited solid-state laser. Method.   The cured photosensitive resin is formed by photocuring a liquid photosensitive resin at 20 ° C., and the cured photosensitive resin has at least one bond selected from a carbonate bond and an ester bond. And a method for producing a sheet-like or cylindrical resin-made printed substrate according to any one of claims 1 to 8, which has at least one kind of bond selected from a urethane bond, a urea bond, and an amide bond. .   The sheet or cylindrical shape according to any one of claims 1 to 9, wherein the depth of the cured photosensitive resin engraved with one pulse of a pulsed ultraviolet laser is 0.05 µm or more and 10 µm or less. Manufacturing method of resin-made printing substrate.   The laser engraving apparatus has a pulsed ultraviolet laser, a galvano mirror for scanning the laser beam in the longitudinal direction of the cylinder, a condensing lens for condensing the laser beam, an optical shutter or a mechanical shutter, and the cylinder A mechanism for holding the long axis, a mechanism for rotating the held cylinder in the circumferential direction, and a mechanism for moving the galvano mirror in the long axis direction of the cylinder or a mechanism for moving the cylinder in the long axis direction. Laser engraving device for fine processing.   The laser engraving apparatus further includes a continuous wave infrared laser and an optical shutter, or a pulsed infrared laser and an optical shutter or a mechanical shutter, and further includes a condensing lens for condensing the laser beam. Laser engraving device for microfabrication described in 1.