JP2009190329A - Resin composition for laser carved original printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which is excellent in ink repellent properties and is best-suited for manufacturing an original printing plate and a printing plate, both having an excellent suppressing effect on ink smudge. <P>SOLUTION: The resin composition for a laser carved original printing plate includes a resin (a) which includes a siloxane bond in the main chain, with a number-average molecular weight of not less than 500 to not more than 300,000. Also, the original printing plate and the printing plate which are obtained from the resin composition, are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin composition for a laser engraving printing original plate containing a novel resin, a printing original plate obtainable by curing the resin composition, a method for producing the printing original plate, and the printing original plate subjected to laser engraving. Concerning the printing plate.

In recent years, flexographic printing has been widely used as a method for printing on soft packaging such as paper and film.
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 a printing plate used for this, a photosensitive resin is usually used in many cases, and a liquid resin or a solid resin plate formed into a sheet shape is used. A method has been used in which a photomask is placed on a photosensitive resin, light is irradiated through the mask to cause a crosslinking reaction, and then a non-crosslinked portion is washed away with a developer. In recent years, a thin light absorption layer called a black layer is provided on the surface of a photosensitive resin, and a laser beam is irradiated on the thin light absorption layer to form a mask image directly on the photosensitive resin plate. A so-called flexo CTP (Computer to Plate) technology has been developed to irradiate light through the mask to cause a crosslinking reaction, and then wash away the non-crosslinked portion of the light non-irradiated portion with a developer, thereby improving the efficiency of printing plate production. Adoption is progressing from the effect. However, this technique also has a limited efficiency improvement effect such as the development process remaining, and development of a technique that directly forms a relief image on a printing original plate using a laser and does not require development is required. .

As the method, a method of engraving a printing original plate directly with a laser can be mentioned. As a printing plate material for relief printing represented by flexographic printing, there is a laser engraving plate. There are advantages such as shortening of plate making time and reduction of waste.
Under such circumstances, in Patent Document 1, silicone oil is added to the resin composition for laser engraving printing original plate.
In Patent Document 2, a compound that converts laser light into heat, a polymer compound having film forming ability, a photothermal exchange layer containing a photopolymerization initiator and an ethylenically unsaturated monomer, and a silicone rubber layer are laminated in this order. Further, there is a description of a laser-sensitive dampening-free lithographic printing original plate characterized in that the photothermal conversion layer and the silicone rubber layer are reacted by performing overall exposure with energy rays after the formation of the silicone rubber layer.
JP 2004-160898 A JP 09-146264 A

However, in fact, it is not known that laser-engraved printing plates are sufficiently excellent in ink repellency and sufficiently prevent ink stains on the plate.
The technique disclosed in Patent Document 1 is a technique in which silicone oil is added as a component of a resin composition and does not introduce a siloxane bond into the main chain in the resin. In addition, when the amount of silicone oil added is increased, there is a problem in that separation occurs without being uniformly mixed with other components.
The invention disclosed in Patent Document 2 is a dampening water-free lithographic printing original plate obtained by further laminating a silicone rubber layer on a photothermal conversion layer, which is different from the introduction of a siloxane bond into the main chain in a resin, and printing. There is no description about suppression of ink stains on the plate.
That is, the present invention produces a resin composition containing a novel resin having a specific structure, and further uses this to produce a laser-engravable printing original plate and printing plate that are extremely excellent in suppressing ink stains on the plate. The purpose is to provide.

  As a result of intensive studies on the resin in order to solve the above-mentioned problems, the siloxane bond, which has been difficult to introduce in the past due to phase separation from other components, has been introduced in the main chain in the resin. By using a resin composition excellent in ink repellency containing a novel resin having a compound introduced therein, it is possible to obtain an original plate and printing plate capable of laser engraving having an excellent effect of suppressing ink stains on the plate. The present invention has been completed.

That is, the present invention is as follows.
1. Resin for laser engraving printing original plate containing siloxane bond in main chain, polymerizable unsaturated group, resin (a) having number average molecular weight of 500 or more and 300,000 or less, and photopolymerization initiator (c) Composition.
2. The resin composition for a laser engraving printing original plate as described in 1 above, wherein the resin (a) has a polymerizable unsaturated group.
3. Furthermore, the resin composition for laser engraving printing original plate of the preceding clause 1 or 2 containing a photoinitiator (c).
4). 4. The resin composition for a laser engraving printing original plate as described in any one of 1 to 3 above, wherein the resin composition further contains an organic compound (b) having a polymerizable unsaturated group and a number average molecular weight of less than 1000.
5. 5. The resin composition for a laser engraving printing original plate as described in any one of 1 to 4 above, wherein the number average molecular weight of the repeating unit having a siloxane bond contained in the resin (a) is 1000 or more and 10,000 or less.
6). 6. The resin composition for laser engraving printing original plate as described in any one of 1 to 5 above, wherein the number average molecular weight of the repeating unit having a siloxane bond contained in the resin (a) is 2000 or more and 7000 or less.
7). 7. The resin for laser engraving printing original plate according to any one of 1 to 6 above, wherein the resin (a) is a resin having at least one chemical bond selected from the group consisting of a carbonate bond, a urethane bond, and an ester bond. Composition.
8). 8. The resin composition for a laser engraving printing original plate as described in any one of 4 to 7 above, wherein 20% by mass or more of the total amount of the organic compound (b) is an alicyclic derivative and / or an aromatic derivative.
9. 9. The resin composition for laser engraving printing original plate according to any one of items 3 to 8, wherein the photopolymerization initiator (c) includes a hydrogen abstraction type photopolymerization initiator and / or a decay type photopolymerization initiator.
10. The resin composition for a laser engraving printing original plate as described in any one of 1 to 9 above, which is liquid at 20 ° C.
11. Any one of the preceding items 1 to 10 further containing 1 to 100 parts by mass of inorganic fine particles having a number average particle size of 0.01 μm or more and 10 μm or less with respect to 100 parts by mass of the resin composition for laser engraving printing original plate. The resin composition for a laser engraving printing original plate as described in the item.
12 A step of forming the laser engraving printing precursor resin composition according to any one of items 1 to 11 on a support in a sheet shape or a cylindrical shape, and irradiating the formed resin composition with a high energy active ray and curing A method for producing a laser engraving printing original plate including a caulking step.
13. 12. A laser engraving printing original plate obtainable by curing the resin composition for laser engraving printing original plate according to any one of 1 to 11 above.
14 14. The laser engraving printing original plate according to 13 above, further comprising a support on the non-printing surface side of the laser engraving printing original plate. 15. The laser engraving printing original plate according to 14 above, wherein the support is a hollow cylindrical support. 16. The laser engraving printing original plate according to item 14 or 15, further comprising one or more cushion layers between the laser engraving printing original plate and the support. 17. The laser engraving printing original plate according to 16 above, wherein the cushion layer contains hollow microcapsules.
18. 18. The laser engraving printing original plate according to any one of items 15 to 17, further comprising one or more circumferential length adjusting layers between the laser engraving printing original plate and the hollow cylindrical support.
19. 19. The laser engraving printing original plate according to any one of items 13 to 18, wherein the outermost surface of the laser engraving printing original plate is surface-adjusted by at least one method selected from cutting, grinding, and polishing.
20. 20. A printing plate obtained by laser engraving the printing original plate according to any one of items 13 to 19.

  According to the present invention, a resin composition having excellent ink repellency can be provided. Then, by using this resin composition, it is possible to provide a printing original plate and a printing plate capable of laser engraving, which are extremely excellent in the ink stain suppression effect of the plate.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
[Resin (a)]
The resin (a) needs to contain a siloxane bond in the main chain. A siloxane bond means a molecular structure in which silicon (Si) and oxygen (O) are alternately bonded.
Although the details regarding the mechanism relating to the excellent ink repellency of the resin composition of the present invention are not clear, the siloxane bond that is stably bonded in the resin causes the ink to be more than the siloxane bond added as an additive. The inventor presumes that the ink repellency is improved due to the low affinity for
The principal chain having a siloxane _{bond, R p Q r X s SiO} (4-p-r-s) containing a silicone compound represented by the following average compositional formula (1) / 2 (1)

In formula (1), R is substituted with a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group. An alkyl group having 1 to 30 carbon atoms (carbon number before substitution), an aryl group having 6 to 20 carbon atoms substituted with a halogen atom, an alkoxycarbonyl group having 2 to 30 carbon atoms, a carboxyl group, or a salt thereof. A monovalent group containing, a monovalent group containing a sulfo group or a salt thereof, and one or more hydrocarbon groups selected from the group consisting of a polyoxyalkylene group,
Q and X are each a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group. A substituted alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 20 carbon atoms substituted with a halogen atom, an alkoxycarbonyl group having 2 to 30 carbon atoms, a monovalent group including a carboxyl group or a salt thereof, A monovalent group containing a sulfo group or a salt thereof, and one or more hydrocarbon groups selected from the group consisting of a polyoxyalkylene group,
p, r and s are
0 <p <4,
0 ≦ r <4,
0 ≦ s <4,
And (p + r + s) <4.

In the present embodiment, the resin (a) can be obtained from a compound having a siloxane bond in order to introduce the siloxane bond into the main chain.
Examples of the compound having a siloxane bond for introducing a siloxane bond into the main chain include silicone oil. Silicone oils include low to high viscosity organopolysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, dimethylsiloxane / methylphenylsiloxane copolymer, octamethylcyclotetrasiloxane, decamethylcyclopenta Cyclic siloxanes such as siloxane, dodecamethylcyclohexasiloxane, tetramethyltetrahydrogencyclotetrasiloxane, tetramethyltetraphenylcyclotetrasiloxane, etc., high degree of polymerization of gum-like dimethylpolysiloxane, gum-like dimethylsiloxane / methylphenylsiloxane copolymer Silicone rubber such as coalescence, and cyclic siloxane solution of silicone rubber, trimethylsiloxysilicic acid, trimethylsiloxysilicic acid cyclic siloxa Solution, higher alkoxy-modified silicones such as stearoxysilicone silicone, higher fatty acid-modified silicone.

  Of these, reactive silicone oil is preferred. Examples include monoamine modified silicone oil, diamine modified silicone oil, special amino modified silicone oil, epoxy modified silicone oil, alicyclic epoxy modified silicone oil, carbinol modified silicone oil, mercapto modified silicone oil, carboxyl modified silicone oil, hydrogen modified Silicone oil, amino / polyether modified silicone oil, epoxy / polyether modified silicone oil, epoxy / aralkyl modified silicone oil, reactive silicone oil silicone oil, methacrylic modified silicone oil, polyether modified silicone oil, mercapto modified silicone oil, phenol Modified silicone oil, silanol modified silicone oil, fluorine modified silicone oil, side chain Mino both ends methoxy-modified silicone oil, and diol-modified silicone oil. By using these reactive silicone oils, it is easy to introduce a siloxane bond into the resin (a).

  Of the reactive silicone oils, both-end modified silicone oils are preferred. Examples include both-end amino-modified silicone oil, both-end epoxy-modified silicone oil, both-end alicyclic epoxy-modified silicone oil, both-end carbinol-modified silicone oil, both-end methacryl-modified silicone oil, both-end polyether-modified silicone oil, both Examples include terminal mercapto-modified silicone oil, both-terminal carboxy-modified silicone oil, both-terminal phenol-modified silicone oil, and both-terminal silanol-modified silicone oil. By using these both-end-type silicone oils, it is easy to introduce a siloxane bond to the main chain of the resin (a), and furthermore, since the reactive functional groups are present at both ends, the molecular weight can be easily adjusted. Among these, from the viewpoint of handling properties such as reactivity, odor, and irritation, both terminal carbinol-modified silicone oils are preferable.

Further, the molecular weight of the compound having a siloxane bond for introducing a siloxane bond into the main chain of the resin is preferably 1000 or more and 10,000 or less, more preferably 2000 or more and 7000 or less, and further preferably 3000 or more and 6000 or less. Within this range, the ink repellency due to the siloxane bond in the main chain is sufficiently exhibited, and the fluidity of the silicone compound can be ensured, so that handling is easy.
The resin (a) is a resin having a number average molecular weight of 500 to 300,000, preferably 2,000 to 250,000, more preferably 3,000 to 200,000. When the number average molecular weight is 500 or more, the strength of the printing original plate and the printing plate is improved, so that it tends to withstand repeated use. On the other hand, if it is 300,000 or less, the viscosity at the time of molding of the resin composition does not increase excessively, so that the printing original plate and the printing plate tend to be more easily 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.

  Further, the resin (a) may not necessarily have a polymerizable unsaturated group in the molecule, for example, when cured by electron beam irradiation, but preferably has a polymerizable unsaturated group in the molecule. It is preferable to have 0.3 or more polymerizable unsaturated groups on an average per molecule. When it has an average of 0.3 or more polymerizable unsaturated groups per molecule, it is preferable because the mechanical strength of the printing original plate and the printing plate is improved and the durability tends to be good. In consideration of the mechanical strength of the printing original plate and the printing plate, the number of polymerizable unsaturated groups in the resin (a) is more preferably 0.5 or more, more preferably 0.7 or more per molecule. The number of polymerizable unsaturated groups in the resin (a) is 2.0 per molecule from the viewpoint of improving the mechanical properties of the cured resin and simplifying the process of adding polymerizable unsaturated groups. The following is preferred. Here, the “polymerizable unsaturated group” means a polymerizable functional group involved in radical polymerization reaction or addition polymerization reaction. The position of the polymerizable unsaturated group is preferably directly bonded to the polymer main chain, the end of the polymer side chain, or the polymer main chain or side chain. The average number of polymerizable unsaturated groups contained in one molecule of the resin (a) can be determined by a molecular structure analysis method using a nuclear magnetic resonance spectrum method (NMR method).

Furthermore, the resin (a) preferably has at least one chemical bond selected from the group consisting of a carbonate bond, a urethane bond, and an ester bond in the molecule. When the resin (a) has the chemical bond, the resistance of the printing original plate and the printing plate to an ink cleaning agent containing an ester solvent used in printing or an ink cleaning agent containing a hydrocarbon solvent tends to be improved. Therefore, it is preferable.
The method for producing the resin (a) is not particularly limited as long as it is obtained by reacting a compound having a siloxane bond, and has, for example, a carbonate bond, an ester bond, and a hydroxyl group, an amino group, an epoxy. The above reaction with a compound having a molecular weight of about several thousand having a plurality of reactive groups such as a group, a carboxyl group, an acid anhydride group, a ketone group, a hydrazine residue, an isocyanate group, an isothiocyanate group, a cyclic carbonate group, and an alkoxycarbonyl group After reacting a compound having a plurality of functional groups that can be bonded to the functional group (for example, polyisocyanate having a hydroxyl group, an amino group, etc.), adjusting the molecular weight, converting the molecular end to a binding group, etc. Introducing a polymerizable unsaturated group at the terminal by reacting a functional group capable of reacting with a terminal bondable group with an organic compound having a polymerizable unsaturated group It can be used and a method.

  Examples of the compound having a carbonate bond used in the production of the resin (a) include aliphatic polycarbonates such as 4,6-polyalkylene carbonate diol, 8,9-polyalkylene carbonate diol, and 5,6-polyalkylene carbonate diol. A diol etc. can be mentioned. Moreover, you may use the aliphatic polycarbonate diol which has an aromatic type molecular structure in a molecule | numerator. The terminal hydroxyl group of these compounds is tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tetramethylxylene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, trimethylhexamethylene diisocyanate, p-phenylene diisocyanate, cyclohexene. Diisocyanate compounds such as silylene diisocyanate, lysine diisocyanate, triphenylmethane diisocyanate, triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, naphthalene-1,3,7-triisocyanate, biphenyl-2, Tris such as 4,4'-triisocyanate By condensation reaction of the isocyanate compound, thereby introducing a urethane bond may be high molecular weight. Furthermore, a terminal hydroxyl group or isocyanate group can also be used for introducing a polymerizable unsaturated group.

  Examples of the compound having an ester bond used in the production of the resin (a) include adipic acid, phthalic acid, malonic acid, succinic acid, itaconic acid, oxalic acid, glutaric acid, pimelic acid, speric acid, azelanic acid, and sebacin. Dicarboxylic acid compounds such as acid, fumaric acid, isophthalic acid, terephthalic acid and the like, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1 , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, piconal, cyclopentanediol, cyclohexanediol, etc. Has a hydroxyl group Polyesters obtained a compound with condensation reaction, polyesters such as polycaprolactone and the like. By subjecting the diisocyanate compound to a condensation reaction with the terminal hydroxyl group or carboxyl group of these compounds, a urethane bond can be introduced and the molecular weight can be increased. Furthermore, a terminal hydroxyl group, carboxyl group or isocyanate group can also be used for introducing a polymerizable unsaturated group.

The resin (a) preferably contains a liquid resin having a glass transition temperature of 20 ° C. or lower, and preferably contains a liquid resin having a glass transition temperature of 0 ° C. or lower. Examples of such liquid resins include compounds having a hydrocarbon chain such as polyethylene, polybutadiene, hydrogenated polybutadiene, and polyisoprene, polyester compounds having an ester bond such as adipate and polycaprolactone, compounds having a polycarbonate structure, polydimethyl Examples thereof include a compound having a siloxane skeleton. In particular, unsaturated polyurethanes having a polycarbonate structure are more preferable from the viewpoint of weather resistance. 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. However, it is a term corresponding to an elastomer having the property of recovering its original shape in a short time when external force is removed.
The viscosity of the resin (a) at 20 ° C. is preferably 10 Pa · s to 10 kPa · s, more preferably 30 Pa · s to 7 kPa · s, and further preferably 50 Pa · s to 5 kPa · s. If the viscosity is 10 Pa · s or more, the mechanical strength tends to be good when it is used as a printing original plate. If the viscosity is 10 kPa · s or less, it is easily deformed even at room temperature and mixed with other compositions. It tends to be easy to form.

[Photoinitiator (c)]
The photopolymerization initiator (c) can be selected from those commonly used. For example, radical polymerization exemplified in “Polymer Data Handbook-Fundamentals” edited by the Society of Polymer Science, published in 1986 by Baifukan. , Cationic polymerization, anionic polymerization photopolymerization initiator, and the like can be used. The photopolymerization initiator (c) for inducing a radical polymerization reaction preferably contains a hydrogen abstraction type photopolymerization initiator and / or a decay type photopolymerization initiator.

The hydrogen abstraction type photopolymerization initiator is not particularly limited as long as it is a compound that draws hydrogen from the surrounding medium through an excited triplet state to generate radicals. However, efficient photocuring and light under visible light can be used. From the viewpoint of the stability of the polymerization initiator, it is preferable to use an aromatic ketone.
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. Benzophenones refer to benzophenone and derivatives thereof, and specifically include 3,3 ′, 4,4′-benzophenone tetracarboxylic anhydride, 3,3 ′, 4,4′-tetramethoxybenzophenone, and the like. . Examples of Michler ketones include Michler ketone and derivatives thereof. Xanthenes refer to derivatives substituted with a xantealkyl group, a phenyl group, or a halogen group. The thioxanthone refers to thioxanthone and a thioxanthone derivative substituted with an alkyl group, a phenyl group, or a halogen group, and specific examples include ethylthioxanthone, methylthioxanthone, and chlorothioxanthone. Anthraquinones refer to anthraquinone and anthraquinone derivatives substituted with an alkyl group, a phenyl group, a halogen group, or the like.

  The addition amount of the hydrogen abstraction type photopolymerization initiator is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the resin (a). It is. If the addition amount of the hydrogen abstraction type photopolymerization initiator is within this range, when the photosensitive resin composition is photocured, the curability of the cured product surface can be sufficiently secured and good weather resistance can be obtained. There is a tendency. Moreover, ensuring the curability of the cured product surface is suitable for cutting, grinding or polishing the cured product surface.

  A collapsible photopolymerization initiator is a compound that generates an active radical by generating a cleavage reaction in the molecule after light absorption. 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, compounds described in “Photosensitive polymer” (Kodansha, 1977, page 228), and the like. 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 organic sulfur compounds include aromatic thiols, mono- and disulfides, thiuram sulfides, dithiocarbamates, S-acyl dithiocarbamates, thiosulfonates, sulfoxides, sulfinates, dithiocarbonates, and the like. Examples of diketones include benzyl and methylbenzoyl formate.

The addition amount of the disintegration type photopolymerization initiator is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.3 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the resin (a). is there. When the addition amount is within this range, even when the resin composition is photocured in the air, the curability inside the cured product can be sufficiently secured.
Moreover, the compound which has the site | part which functions as a hydrogen abstraction type photoinitiator and the site | part which functions as a decay type photoinitiator in the same molecule as a photoinitiator (c) can also be used. Examples of such a compound include α-aminoacetophenones, such as 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propan-1-one, a compound represented by the following formula (2) Etc.

The addition 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 preferably 0.1% by mass or more and 10% by mass or less, More preferably, it is 0.3 mass% or more and 3 mass% or less. If the addition amount is within this range, the mechanical properties of the cured product can be sufficiently ensured even when the resin composition is photocured in the air.
In addition, a compound that induces an addition polymerization reaction by absorbing light and generating an acid or a base can also be used as the photopolymerization initiator (c). Examples of such compounds include photocation polymerization initiators such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts. It is preferable that the addition amount of these compounds is 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin (a).

[Resin composition]
The resin composition needs to contain resin (a), and can be used for manufacture of a printing original plate and a printing plate.
The resin composition is not particularly limited, but in addition to the resin (a), one or more selected from the group consisting of a photopolymerization initiator (c), an organic compound (b), and inorganic fine particles depending on applications and purposes. It is preferable to contain.
Furthermore, the resin composition may contain additives such as fluorine-containing monomers, petroleum waxes, monomers having hydrocarbon chains, polymerization inhibitors, ultraviolet absorbers, dyes, lubricants, surfactants, plasticizers, and fragrances. it can.

The resin composition is preferably liquid at 20 ° C. The term “liquid at 20 ° C.” as used herein means a polymer that has the property of being easily flow-variable and solidifying into a deformed shape by cooling. It is a term corresponding to an elastomer having the property of recovering to its original shape in a short time when it is deformed and external force is removed. Due to this property, when the resin composition is formed into a sheet or cylinder in order to obtain a printing original plate, good thickness accuracy and dimensional accuracy can be obtained.
The viscosity at 20 ° C. of the resin composition is preferably 10 Pa · s or more and 10 kPa · s or less at 20 ° C. More preferably, it is 50 Pa · s or more and 5 kPa · s or less. When the viscosity is 10 Pa · s or more, the mechanical strength of the printing plate to be produced is sufficient, and the shape can be easily held and processed even when it is formed into a cylindrical shape. If the viscosity is 10 kPa · s or less, it is easy to be deformed and processed easily without increasing the temperature. It is easy to form into a sheet-like or cylindrical printing plate and the process is simple. In particular, in order to obtain a printing plate with high thickness accuracy, the viscosity is preferably 100 Pa · s or more, more preferably 200 Pa · s so that the resin composition for laser engraving printing original plate does not cause a phenomenon such as sag due to gravity. As described above, more preferably 500 Pa · s or more.

[Organic compound (b)]
The organic compound (b) is an organic compound having a polymerizable unsaturated group and having a number average molecular weight of less than 1000. The number average molecular weight is preferably less than 1000 from the viewpoint of easy dilution with the resin (a), and preferably 100 or more from the viewpoint of handling such as low volatility.
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).
In this Embodiment, content in particular of an organic compound (b) is although it does not restrict | limit, Preferably it is 20 mass parts or more and 300 mass parts or less with respect to 100 mass parts of resin (a), More preferably, it is 50 mass parts or more. It is 250 parts by mass or less. When the content of the organic compound (b) is 20 parts by mass or more, the printing original plate and the printing plate that are cured products of the resin composition tend to have sufficient mechanical strength, and are 300 parts by mass or less. The curing shrinkage of the printing original plate and the printing plate, which are cured products of the resin composition, tends to be reduced.

  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 etc. are mentioned. (Meth) acrylic acid and its derivatives are preferable examples from the viewpoints of the abundance of the kind, price, decomposability upon laser light irradiation, and the like. Examples of the derivatives include alicyclic compounds having a cycloalkyl group, a bicycloalkyl group, a cycloalkene group, a bicycloalkene group, an aromatic compound having a benzyl group, a phenyl group, a phenoxy group, a fluorene group, an alkyl group, and a halogenated group. Examples include compounds having an alkyl group, an alkoxyalkyl group, a hydroxyalkyl group, an aminoalkyl group, a glycidyl group, and ester compounds with polyhydric alcohols such as alkylene glycol, polyoxyalkylene glycol, polyalkylene glycol, and trimethylolpropane. .

  As specific examples of the organic compound (b), the compound having an epoxy group that undergoes addition polymerization reaction includes compounds obtained by reacting various diols and polyols such as triol with epichlorohydrin, and a peracid for an ethylene bond in the molecule. An epoxy compound obtained by reacting 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 diglycidyl Mention may be made of epoxy compounds such as ethers.

The organic compound (b) having a polymerizable unsaturated group can be selected from one or more types depending on the purpose. 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 due to an organic solvent such as alcohol or ester which is a solvent for printing ink. It is preferable.
In order to increase the mechanical strength of the printing original plate obtained from the resin composition, the organic compound (b) preferably contains an alicyclic derivative and / or an aromatic derivative. In this case, the content of the alicyclic derivative and / or aromatic derivative is preferably 20% by mass or more, more preferably 50% by mass or more, based on the total amount of the organic compound (b). 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, which can be selected by utilizing the technical knowledge of known photosensitive resins for printing. it can.
The resin (a) and / or the organic compound (b) is a compound having at least one chemical bond selected from the group consisting of a carbonate bond, an ester bond, and an ether bond in the molecular chain, and / or aliphatic saturation. A compound having a hydrocarbon chain and having a urethane bond and / or a compound having an aliphatic unsaturated hydrocarbon chain and having a urethane bond is preferable because the solvent resistance of the printing plate is improved. Among them, a compound having a carbonate bond, a compound having an aliphatic saturated hydrocarbon chain and a urethane bond, a compound having an aliphatic unsaturated hydrocarbon difference and a urethane bond are ester solvents that are frequently used in solvent inks. Shows particularly high solvent resistance.

[Additive]
In the present embodiment, examples of additives include fluorine-containing monomers, petroleum waxes, monomers having hydrocarbon chains, dyes, pigments, polymerization inhibitors, ultraviolet absorbers, lubricants, surfactants, plasticizers, and fragrances. Is mentioned. From the viewpoint of the ink stain inhibiting effect, it is preferable that the additive contains at least one of a fluorine-containing compound, a compound having a C10 or higher carbon chain and a polymerizable unsaturated group, and a wax.
Although the total addition amount of an additive is not restrict | limited in particular, It is preferable that it is 0.1 to 50 mass parts with respect to 100 mass parts of resin (a).
The fluorine-containing monomer is not particularly limited as long as it is a fluorine-containing monomer having a polymerizable functional group. Examples of the fluorine-containing monomer having a polymerizable functional group include a monomer having a double bond, a triple bond, an epoxy group, an oxetane skeleton, or a ketene acetal skeleton.

  Specifically, tetrafluoroethylene (hereinafter referred to as TFE), hexafluoropropylene (hereinafter referred to as HFP), vinylidene fluoride (hereinafter referred to as VdF), trifluoroethylene, 1,2-difluoroethylene, fluorine. Vinyl fluoride, trifluoropropylene, chlorotrifluoroethylene (hereinafter referred to as CTFE), 3,3,3-trifluoropropene, 2-trifluoromethyl-3,3,3-trifluoro-1-propene, perfluoro Linear or branched aliphatic fluoroolefins such as (butylethylene), perfluoro (methyl vinyl ether) (hereinafter referred to as PMVE), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether) (hereinafter, Perfluoro (PPVE)) Perfluoro (alkenyl vinyl ether) such as perfluoro (1,3-dioxole), perfluoro (butenyl vinyl ether) (hereinafter referred to as BVE), and perfluoro (2,2-dimethyl-1,3). -Dioxole) (hereinafter referred to as PDD), peroxyolefin-containing cyclic perfluoroolefins such as perfluoro- (2-methylene-4-methyl-1,3-dioxolane), (perfluorobutyl) ethyl acrylate, (Perfluorohexyl) ethyl acrylate (hereinafter referred to as FHA), (perfluoroheptyl) methyl acrylate, (perfluorooctyl) ethyl acrylate (hereinafter referred to as FOA) and the like (perfluoroalkyl) ethyl acrylate, (perfluorobutyl) ) Echi (Perfluoroalkyl) ethyl methacrylate such as methacrylate, (perfluorohexyl) ethyl methacrylate (hereinafter referred to as FHMA), (perfluoroheptyl) methyl methacrylate, (perfluorooctyl) ethyl methacrylate (hereinafter referred to as FOMA) , Α-fluorostyrene, β-fluorostyrene, α, β-difluorostyrene, β, β-difluorostyrene, α, β, β-trifluorostyrene, α-trifluoromethylstyrene, 2,4,6-tri ( Trifluoromethyl) styrene, 2,3,4,5,6-pentafluorostyrene, perfluoro (styrene), fluorostyrene such as 2,3,4,5,6-pentafluoro-α-methylstyrene, and the like. It is done. Among these, compounds having a long carbon chain such as perfluorooctyl methacrylate are preferable. These fluorine-containing monomers may have a functional group other than the polymerizable functional group.

Petroleum waxes (paraffins) used in the present embodiment are roughly classified into n-paraffins having a linear hydrocarbon chain, isoparaffins having a branched chain, and cycloparaffins having a cyclic chain. Among these, those having a melting point of 65 ° C. or lower are preferred, and more preferably, the melting point is 60 ° C. or lower. If it is this range, when it adds in a resin composition, it will become the tendency for a wax to become a solid hard.
Examples of the monomer having a hydrocarbon chain used in the present embodiment include vinyl esters of aliphatic or aromatic carboxylic acids such as vinyl decanoate, vinyl stearate, and vinyl palmitate, allyl decanoate, allyl stearate, and palmitic acid. Aliphatic or aromatic allyl esters such as allyl acid, allyl stearate, and alkyl vinyl ethers such as vinyl ethyl ether and / or vinyl polyether.
Examples of coloring methods for improving visibility include the use of dyes and pigments. Specific pigments include "HELIOGEN BLUE D 6700" (trade name, manufactured by BASF), "PALIOGEN RED K". 3580 "(trade name, manufactured by BASF) is preferable.

[Inorganic fine particles]
The inorganic fine particles in the present embodiment preferably have a number average particle size of 0.01 μm or more and 10 μm or less. If the number average particle size is in the above range, stickiness can be reduced in the cutting, grinding, and polishing processes, the surface roughness of the printing original plate is less affected, and patterns can be formed by laser engraving without causing defects in the printed image. is there. In addition, the inorganic fine particles in the present embodiment are preferably porous fine particles or nonporous ultra fine particles.
The porous fine particles in the present embodiment are defined as fine particles having fine pores having a pore volume of 0.1 ml / g or more in the particles, or fine particles having fine voids. By containing the porous fine particles, processing becomes easy when the surface of the printing layer is made to have a desired surface roughness. Examples of the processing include cutting, grinding, and polishing. The stickiness of debris and the like generated during processing when the desired surface roughness is obtained by the porous fine particles is reduced, and it becomes easy to precisely process the surface of the printing layer.

The porous fine particles have a specific surface area of 10 m ² / g to 1500 m ² / g, an average pore diameter of 1 nm to 1000 nm, a pore volume of 0.1 ml / g to 10 ml / g, and an oil absorption of 10 ml / 100 g to 2000 ml. / 100 g or less is preferable. The specific surface area is determined from the adsorption isotherm of nitrogen at −196 ° C. based on the BET equation. A nitrogen adsorption method is used to measure the pore volume and the average pore diameter. The oil absorption was measured according to JIS-K5101. When the specific surface area of the porous fine particles is within the above range, for example, when forming an image portion by engraving a printing original plate with a laser, it is suitable for absorbing the removed decomposition product.
The number average particle diameter of the porous fine particles is preferably 0.01 μm or more and 10 μm or less. More preferably, they are 0.5 micrometer or more and 8 micrometers or less, More preferably, they are 1 micrometer or more and 5 micrometers or less. If the number average particle size is in the above range, stickiness can be reduced in the cutting, grinding, and polishing processes, and there is little effect on the surface roughness of the printing original plate, allowing pattern formation by laser engraving without causing defects in the printed image. It is.
The shape of the porous fine particles is not particularly limited, and spherical, flat, acicular, amorphous, or particles having protrusions on the surface can be used. In particular, from the viewpoint of wear resistance, spherical particles having a sphericity of at least 70% in the range of 0.5 to 1 are preferable.

The sphericity is defined as a finger ring that defines the degree of sphericity of the porous fine particles. The sphericity in the present embodiment, the circle of the maximum value D ₁ which fall entirely within projected figure when the projection of the porous microparticles, the minimum value D ₂ of the ratio of a circle projected figure falls completely (D ₁ / D ₂ ). In the case of a true sphere, the sphericity is 1.0. The sphericity of the porous fine particles 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. The porous fine particles preferably have a sphericity of 0.5 or more, preferably 70% or more, more preferably 90% 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 on the basis of 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, it is also possible to use spherical particles having a uniform pore diameter such as particles having hollow inside particles or silica sponge. Although not particularly limited, for example, porous silica, mesoporous silica, silica-zirconia porous gel, porous alumina, porous glass and the like can be mentioned. In addition, since pore diameters cannot be defined for those having voids of several nm to several hundreds nm between layers such as layered clay compounds, the interval between voids existing between layers is defined as the pore diameter in the present invention. .
Furthermore, the surface of the porous fine particles 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 the particles more hydrophilic or hydrophobic. These porous fine particles can be selected from one type or two or more types.
The nonporous ultrafine particles in the present embodiment are defined as particles having a pore volume of less than 0.1 ml / g. The number average particle diameter of the nonporous ultrafine particles is a number average particle diameter for primary particles, and is preferably 10 nm or more and 500 nm or less. More preferably, it is 10 nm or more and 100 nm or less. Within this range, stickiness can be reduced in the cutting, grinding, and polishing steps, the influence on the surface roughness of the printing original plate is small, and a pattern can be formed by laser engraving without causing defects in the printed image.

[Print master / print plate]
The printing original plate of this Embodiment is demonstrated.
The printing original plate of the present embodiment is not limited as long as it can be obtained by curing the resin composition. The printing original plate is formed by, for example, a method including forming a resin composition containing a resin containing a siloxane bond in the main chain into a sheet shape or a cylindrical shape, and curing the formed resin composition by irradiation with high energy actinic radiation. Some are manufactured.
High energy actinic rays are light with a short wavelength such as ultraviolet rays, electron beams, γ rays, X rays, molecular rays and the like. The light source for curing the printing original plate is not particularly limited. For example, a high pressure mercury lamp, an ultra high pressure mercury lamp, an ultraviolet fluorescent lamp, a germicidal lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, and the like can be given. The light irradiated on the relief printing original plate preferably has a wavelength of 200 nm to 400 nm. Although one type of light source may be used, curing may be improved by using two or more types of light sources having different wavelengths, so that two or more types of light sources may be used.

  There is no restriction | limiting in the method of shape | molding the resin composition of this Embodiment in a sheet form or a cylindrical form, The existing molding method of resin can be used. For example, a method of extruding a resin from a nozzle or a die with a machine such as a pump or an extruder and adjusting the thickness with a blade (casting method); a method of adjusting the thickness by calendaring with a roll can be exemplified. It is also possible to perform 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, the resin composition is formed on an underlay called a back film made of a material such as PET (polyethylene terephthalate) or nickel, but it can also be formed directly on a cylinder of a printing press. In that case, a seamless seamless sleeve can be formed. Sleeve molding / engraving device (equipped with a laser light source for laser engraving in a device in which a liquid resin composition is applied onto a cylindrical support and light is irradiated to crosslink and cure the resin composition) The printing original plate can also be formed using. When such an apparatus is used, the printing plate can be formed by laser engraving immediately after forming the sleeve, so a short time that cannot be considered with a conventional rubber sleeve that required several weeks for the forming process. Time machining can be realized.

[Support]
The support used in the present embodiment is preferably a hollow cylindrical support, and the hollow cylindrical support is preferably made of reinforced plastic. Since the support is a hollow cylindrical shape, the support can be easily attached to and detached from the printing press, and since the support is cylindrical, the resin composition can be applied while rotating around the shaft. More uniform coating becomes possible. Further, since the hollow cylindrical support is made of reinforced plastic, the adhesive force with the adhesive layer can be maintained while maintaining the strength.
In the present embodiment, the reinforced plastic is a fiber reinforced plastic, and the fiber reinforced plastic is selected from an epoxy resin, a polyester resin, a polyimide resin, a polyurethane resin, a polyamide resin, a polyketone resin, a polysulfone resin, and a polyphenylene ether resin. It is preferable to contain at least one resin.

Moreover, the fiber formed from the inorganic compound can also be included. The fiber is not particularly limited, but polyester fiber, polyamide fiber, polyurethane fiber, polyimide fiber, polypropylene fiber, polyethylene fiber, polyacrylonitrile fiber, polyphenylene ether fiber, polyvinyl alcohol fiber, phenol fiber, fluororesin fiber, polyether ether ketone Examples thereof include resins, vinylidene fibers, poly-p-phenylenebisoxazole fibers, polyphenylene sulfide fibers, polyclar fibers, polyketone fibers, and synthetic pulp fibers. Preferred examples of short fibers formed from natural organic compounds include bast fibers, vein fibers, and plant fibers such as cellulose.
Moreover, the fiber formed from the inorganic compound can also be included. Preferred examples include glass, carbon, silicon nitride, boron nitride, silicon carbide, alumina, nickel, titanium, copper, iron, tungsten, and chromium.

[Cushion layer]
The cushion layer is not particularly limited, and any cushion layer having rubber elasticity can be used. Examples thereof include natural rubber materials, synthetic rubber materials such as SBR, SBS, and SIS, soft plastic materials such as silicone rubber, urethane rubber, butyl rubber, fluorine rubber, and polyethylene. Moreover, the sheet-like elastomer formed by photocuring the resin composition can also be used. Among these materials, in particular, a sheet material mainly composed of polyethylene or polyurethane used for printing can be mentioned as a preferable material. It is convenient to use a commercially available cushion tape for flexographic printing. The cushion layer preferably has a thickness of 0.10 mm to 6.00 mm. More preferably, it is 0.20 mm or more and 2.00 mm or less, More preferably, it is 0.30 mm or more and 0.70 mm or less. The specific gravity of the cushion layer is preferably 0.20 g / cm ³ or more and 0.90 g / cm ³ or less. More preferably, it is 0.30 g / cm ³ or more and 0.70 g / cm ³ or less, and further preferably 0.40 g / cm ³ or more and 0.60 g / cm ³ or less. The ASKER-C hardness of the cushion layer is preferably 30 or more and 90 or less.

Moreover, by using an adhesive layer for the adhesive layer, the cushion layer is peeled off from the cylindrical support after the cylindrical cushion is used, and the cylindrical support can be easily used again.
In the present embodiment, the cushion layer preferably further includes fine particles having a number average particle diameter of 0.1 μm or more and 200 μm or less. As such fine particles, inorganic fine particles, organic fine particles, hollow capsule-shaped fine particles and the like can be used. By containing the fine particles, the thixotropy is improved, so that the application of the resin composition for a laser engraving printing original plate to the support tends to be easy.

The number average particle diameter of the fine particles is from 0.1 μm to 200 μm, more preferably from 0.5 μm to 150 μm, and even more preferably from 1.0 μm to 100 μm. Here, the number average particle diameter of the fine particles refers to an average value of the major axis values measured by microscopic observation. Specifically, the magnification is adjusted so that at least about 50 fine particles or bubbles enter the visual field of the microscope, and the major axis of the fine particles or bubbles is measured. Although it is preferable to use a microscope having a length measuring function, the dimensions may be measured based on a photograph taken using a camera.
Here, examples of the inorganic fine particles include silica, alumina, calcium carbonate, zeolite, magnesium hydroxide, zirconium silicate and the like. The average particle size of the inorganic fine particles is preferably 10 nm to 30 μm, more preferably 0.1 μm to 20 μm, and still more preferably 0.5 μm to 10 μm.
As the organic fine particles, fine particles having at least one kind of skeleton selected from a polysiloxane skeleton, a polystyrene skeleton, a poly (meth) acrylate skeleton, a polyurethane skeleton, and a polyacrylonitrile skeleton have mechanical strength and solvent resistance. It is preferable from the viewpoint of balancing. Examples of such organic fine particles include silicone rubber, crosslinked acrylic acid fine particles, crosslinked acrylic acid porous fine particles, and crosslinked polystyrene.

The hollow capsule-shaped fine particles are fine particles having a composite composition of 1 μm to several hundred μm, which have different compositions between the outer shell and the inner core. The method for producing the hollow capsule is roughly divided into an interfacial polymerization method, a coacervation method, an interfacial precipitation method, and a submerged drying method. In principle, the atomized core material is dispersed in a suitable medium and then coated with a film of fine particles. As a conventional method for producing a hollow microcapsule, there is a method of producing a microcapsule enclosing a liquid and evaporating the liquid inside to make it hollow, or a method of producing a similar microcapsule by thermal expansion. .
As the hollow capsule-shaped fine particles, inorganic fine particles may be attached to the surface of the hollow capsule-shaped organic fine particles. Due to the presence of inorganic fine particles on the surface, the solubility in the resin composition for laser engraving printing original plate is lowered, and it can be stably present in the resin composition for laser engraving printing original plate for a long time. The average particle size of the inorganic fine particles present on the surface is preferably 10 nm or more and 30 μm or less, more preferably 0.1 μm or more and 20 μm or less, and further preferably 0.5 μm or more and 10 μm or less. Examples of the material of the inorganic fine particles present on the surface include silica, alumina, calcium carbonate, zeolite, magnesium hydroxide, zirconium silicate and the like.

[Perimeter adjustment layer]
It is preferable that the thickness of the circumferential length adjusting layer of the present invention can be arbitrarily changed according to the repeat length for printing with a printing press. The resin composition that can be used may be a solid resin composition at 20 ° C., but a liquid resin composition is particularly preferable from the viewpoint of arbitrarily changing the thickness of the circumference adjusting layer. . A solvent may be contained in the liquid resin composition, but since a solvent removal step is required, a solventless liquid resin composition is more preferable. When the liquid resin composition is used, a seamless layer having a uniform film thickness can be formed. The preferred viscosity of the liquid resin composition is 10 Pa · s or more and 10 kPa · s or less, more preferably 500 Pa · s or more and 5 kPa · s or less at 20 ° C. In order to form a thick film, dripping may occur due to gravity and the film thickness may change, so the viscosity range as described above is preferable. Further, when the film thickness to be molded is very thin, it is desirable to keep the viscosity low. As a method of reducing the viscosity, a method of adding a solvent can also be used as a simple method.

[Cutting / Grinding / Polishing]
When processing the surface, it is preferable to adjust the surface by at least one method selected from cutting, grinding, and polishing. Although it is possible to process the surface using only the cutting process, it is preferable to perform the polishing process after the cutting process or the grinding process because the surface shape of the printing original plate can be adjusted more precisely.
Processing by cutting the surface of the printing original plate is not particularly limited, and examples thereof include processing with a blade such as a lathe, a drilling machine, a milling machine, a shaper, a planer, and an NC machine tool.
Examples of the processing by grinding the surface of the printing original plate include processing by a grindstone. The material of the grinding wheel used for grinding is not particularly limited, but examples thereof include alumina-based and silicon carbide-based materials. Examples of the material of the grindstone include brown alumina, white alumina, light red alumina, and pulverized alumina in the case of alumina, and black silicon carbide and green silicon carbide in the case of silicon carbide.
Regarding the particle size of the abrasive grains of the grinding wheel used for grinding, a grinding wheel of 8 or more and 5000 or less is preferably used. Examples of the main component of the binder for bonding abrasive grains include feldspar soluble viscosity / flux, bakelite artificial resin, sodium silicate flux, natural / artificial rubber / sulfur, shellac natural resin, metal foil, and the like.

The polishing body used for polishing the surface of the printing original plate is not particularly limited, and examples thereof include polishing films such as polishing paper, wrapping films, and mirror films, and polishing wheels.
As a material for the abrasive on the surface of the abrasive paper or the abrasive film, at least one kind of fine particles selected from metals, ceramics, and carbon compounds is preferable. As an example of the metal fine particles, a relatively hard material such as chromium, titanium, nickel, and iron is preferable. Specific examples of ceramics include alumina, silica, silicon nitride, boron nitride, zirconia, zirconium silicate, silicon carbide, and the like. Examples of the material quality of the alumina abrasive grains include brown alumina, pulverized alumina abrasive, light red alumina abrasive, white alumina abrasive, and artificial emery abrasive. Examples of the material quality of the silicon carbide abrasive grains include a black silicon carbide abrasive and a green silicon carbide abrasive. Examples of the carbon compound include compounds such as diamond and graphite. In particular, artificial diamond is preferable as an abrasive. Other abrasive materials include glass-based abrasives such as glass beads, resin-based abrasives such as nylon, polycarbonate, polyester, and methyl metal acrylate, plant-based abrasives such as walnut shell, apricot seed, and peach seed. Can also be used. Furthermore, it is also possible to use a polishing cloth in combination with the above abrasive.

The average particle diameter of the abrasive is preferably from 0.1 μm to 100 μm. A more preferable particle size is 3 μm or more and 100 μm or less. More preferably, the particle size is 9 μm or more and 30 μm or less. If it is in the range of 100 μm or less, a printing original plate that can be suitably used for printing evaluation can be easily prepared.
In particular, the average particle diameter of the abrasive is preferably 20 μm or less from the viewpoint of improving the ink transfer property to the printing medium and the printing quality by reducing the unevenness of the surface of the obtained printing original plate. On the other hand, from the viewpoint of shortening the time required for surface processing and improving the productivity of the printing original plate, the average particle diameter of the abrasive is preferably 12 μm or less.
As the particle size of the grinding wheel surface, 60 to 3000 is preferably used. The material of the polishing wheel is not particularly limited, and examples thereof include iron, alumina, ceramics, carbon compound, grindstone, wood, brush, felt, cork and the like.
The thickness and material of the support such as abrasive paper or abrasive film are not particularly limited, but the thickness is preferably in the range of 1 μm to 1000 μm. More preferably, they are 10 micrometers or more and 500 micrometers, More preferably, they are 25 micrometers-125 micrometers. If it is in the range of 25 μm or more and 125 μm or less, handling such as winding is easy. The shape of the support is not particularly limited, and examples thereof include rolls, disks, sheets, and belts.

In addition, it is possible to polish the printing original plate surface even with dry polishing without interposing liquid when polishing using the polishing body, but the polishing power, uniformity of the printing original plate surface after polishing, less dust generation, polishing In consideration of the removal of heat generated inside, it is preferable to bring the abrasive into contact with the printing original plate while interposing a liquid. Although it does not specifically limit as a liquid to be used, For example, petroleum, machine oil, an alkaline solution, water etc. are mentioned.
In particular, when water is used as a liquid to be interposed during polishing, the printing original plate is less denatured than when other liquids are used, and the waste liquid can be easily treated.
As another preferable aspect of the surface conditioning of the present invention, fine particles having an average particle diameter of at least about 0.1 μm and not more than 100 μm made of at least one substance selected from metals, ceramics, carbon compounds and the like are made to collide with the printing original plate surface. A method is also mentioned.
The method for causing the fine particles to collide with the printing original plate is not particularly limited, and examples thereof include sand blast, shot blast, air blast, blower blast and the like. The material of the fine particles is not particularly limited. For example, glass particles such as glass beads, resin particles such as nylon, polycarbonate, polyester, and methyl metal acrylate, walnut shell, apricot seed, and peach seed. And plant-based particles.

[Laser engraving]
In laser engraving, an image to be formed is converted into digital data, and a relief image is created on an original by operating a laser device using a computer. Any laser may be used for the laser engraving as long as the original includes a wavelength having absorption. In order to perform engraving at a high speed, a high output is desirable, and a laser having an oscillation wavelength in the infrared or near infrared region such as a carbon dioxide laser, a YAG laser, a semiconductor laser, and a fiber laser is preferable. In addition, an ultraviolet laser having an oscillation wavelength in the ultraviolet region, such as an excimer laser, a YAG laser wavelength-converted to the third or fourth harmonic, a copper vapor laser, and the like, can be ablated to cut bonds between organic molecules, Suitable for fine processing. A laser having a very high peak output such as a femtosecond laser can also be used. The laser may be continuous irradiation or pulse irradiation. In general, a resin has absorption at a wavelength in the vicinity of 10 μm. Therefore, when a carbon dioxide laser having an oscillation wavelength in the vicinity of 10 μm is used, it is not particularly necessary to add a component that helps absorption of the laser beam. However, YAG lasers, semiconductor lasers, and fiber lasers have an oscillation wavelength in the vicinity of 1 μm, but since there are not many organic substances that absorb light in this wavelength region, it is necessary to add dyes and pigments that are components that assist in light absorption. . Examples of such dyes include poly (substituted) phthalocyanine compounds and metal-containing phthalocyanine compounds; cyanine compounds; squarylium dyes; chalcogenopyrroloarylidene dyes; chloronium dyes; metal thiolate dyes; Examples include lysine dyes; bis (aminoaryl) polymethine dyes; merocyanine dyes and quinoid dyes. Examples of pigments include dark inorganic pigments such as carbon black, graphite, copper chromite, chromium oxide, cobalt chrome aluminate, iron oxide, and metal powders such as iron, aluminum, copper, and zinc, and Si, Examples include those doped with Mg, P, Co, Ni, Y, and the like. These dyes and pigments may be used alone, in combination of a plurality, or in any form such as a multilayer structure.

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 under carbon dioxide or nitrogen gas. After engraving, the powdery or liquid substance slightly generated on the relief printing plate surface is irradiated with an aqueous cleaning agent by an appropriate method, for example, a method of washing with water containing a solvent or a surfactant, or a high-pressure spray. You may remove using the method, the method of irradiating a high pressure steam, etc.
After the concave / convex pattern is formed by laser engraving, post-exposure can be performed by irradiating the surface of the printing plate on which the pattern is formed with light having a wavelength of 200 nm to 450 nm. 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 a hydrogen abstraction type photopolymerization initiator is contained in the resin composition to be used. Furthermore, before the post-exposure step, the printing plate surface may be treated with a treatment liquid containing a hydrogen abstraction type photopolymerization initiator and exposed. Moreover, you may expose in the state which immersed the printing plate in the process liquid containing a hydrogen abstraction type photoinitiator. A method known in JP-A-2005-212144 is also preferable.

[Printed version]
The printing plate in the present embodiment is a printing plate obtained by laser engraving a printing pattern on the surface of a printing original plate.
There is no limitation on the form of the printing plate of this embodiment, and it can be used as any printing plate such as a flexographic plate, a resin relief plate, or a blanket used for offset, dry offset, reversal offset or gravure offset. Preferably used.

Hereinafter, the present embodiment will be described in detail with reference to production examples, examples, and comparative examples. In the following, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.
(1) Measurement of viscosity The viscosity of the liquid resin composition was measured at 20 ° C using a B-type viscometer (trademark, B8H type; manufactured by Tokyo Keiki Co., Ltd., Japan). Moreover, the viscosity of resin (a) was measured at 50 degreeC using the same apparatus. The unit is Pa · s.
(2) Measurement of the number average molecular weight of the resin (a) The average molecular weight of the resin (a) was such that the polydispersity (Mw / Mn) obtained by using the GPC method was greater than 1.1. The number average molecular weight Mn obtained in (1) was adopted. Specifically, the number average molecular weight of the resin (a) was obtained by conversion with polystyrene having a known molecular weight using a gel permeation chromatography method (GPC method). Using a high-speed GPC device (trade name, HLC-8020, manufactured by Tosoh Corporation, Japan) and a polystyrene packed column (trademark: TSKgel GMHXL; 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. Further, a resin ultraviolet absorption detector was used as a detector, and light at 254 nm 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 resin (a) is determined by removing unreacted low-molecular components using liquid chromatography. Molecular structure analysis was performed using a nuclear magnetic resonance spectrum method (NMR method, manufactured by Bruker Biospin, trademark Avance 600). For example, “1.7 functionality” means that the average number of polymerizable unsaturated groups present in the molecule is 1.7.
(4) Application of resin composition (A) to support On transparent cylindrical support made of fiber-reinforced plastic having an outer diameter of 230.00 mm, a width of 300 mm, and a thickness of 1 mm, the surface was silicon-treated. A polyester film was pasted. The resin composition was coated on the polyester film with a doctor blade, and a metal halide lamp (trade name “M056-L21” manufactured by Eye Graphics Co., Ltd.) was irradiated with 12000 mJ / cm 2 (UV meter and UV-35−). A cushion material for printing for printability evaluation was obtained by irradiating and curing the amount of energy accumulated using an APR filter. A laser engraving printing original plate was prepared by adjusting with a doctor blade so that the thickness after curing was 1.0 mm.

(5) Laser engraving Laser engraving was performed using a carbon dioxide laser engraving machine (trademark: ZED-mini-1000, UK, manufactured by ZED, USA, coherent, equipped with an output 250 W carbon dioxide laser). Sculpture images were created with 120 Lines per inch. For the halftone dots, patterns of 1%, 3%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, and 100% were created. A fine line formed a pattern having a width of 250 μm. For laser engraving, the presence or absence of viscous liquid residue generated by laser engraving and the sharpness of the line drawing were visually determined. A with little liquid debris and good line drawing sharpness, A with some liquid debris or normal line drawing sharpness, B with some liquid debris and normal line drawing sharpness The sample was evaluated as C, and liquid residue was significantly generated and / or the line drawing was poor in sharpness D.
(6) Engraving quality The relief depth was measured to confirm the quality of the engraved printing original plate. “Relief depth” means a difference in height between a printing portion (relief surface) and a non-printing portion (back surface) of a relief printing plate. If the relief depth is set to be large, the area of the relief surface of the fine halftone dot pattern cannot be secured, and the shape is broken and unclear, so the relief depth is set to 0.5 mm. As confirmation of plate reproducibility, it was observed whether the shape of the dots was conical. “Plate reproducibility” means the accuracy with which a printed image is transferred to a relief printing plate. Further, as a confirmation of the plate reproducibility, it was observed whether the dot shape was conical.

(7) Ink Repellency and Ink Stain Suppression Effect Test Printing evaluation was carried out using a printing plate produced by laser engraving. For printing, a desktop proofing machine (trade name “Flexiprof100” manufactured by KR, UK) is used, and the printing plate is pasted on the plate cylinder using cushion tape (trade mark “3M1820” manufactured by 3M, USA). , Coated paper (trade name “Pearl Coat” manufactured by Oji Paper Co., Ltd., mass 106 g / m ² ) using cyan-colored flexo UV ink (trade name “UV Flexo 500” manufactured by T & K Toka, Japan). ) Printed on a single sheet. It was set to a state where an excessive pressure was applied between the anilox roll and the plate cylinder (from a state where the ink was uniformly transferred to the plate, a state where pressure was applied to an extra 0.08 mm). In addition, the pressure between the plate cylinder and the impression cylinder is set to 0.08 mm from the state where the ink is uniformly transferred to the coated paper, and when the first printing is finished, the anilox roll and the plate cylinder contact each other. The ink supply to the plate cylinder was stopped. While maintaining this state, printing was continued with the second, third,..., And it was visually confirmed how many sheets of ink remained. The printing test was terminated when no ink remained on the coated paper.
As a result of this printing evaluation, a plate having high ink repellency has a good ink detachability to the substrate (coated paper), and therefore the printing test is completed with a smaller number of printed sheets. On the other hand, since a plate having low ink repellency does not have sufficient ink detachability to a printing medium, a larger number of printed sheets is required before the printing test is completed.
In this evaluation, if the number of printed sheets is 15 or less, it is recognized that the ink repellency is sufficient. The number is preferably 10 or less, more preferably 5 or less.
In addition, the remaining ink on the plate surface after printing was observed, and the effect of suppressing ink stains on the plate surface was evaluated. The case where ink stains were hardly observed was evaluated as A, the case where ink stains slightly occurred was evaluated as B, and the case where ink stains were markedly generated was evaluated as C.

[Production Example 1: Preparation of resin (α1)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) was added to 413.72 g and g and tolylene diisocyanate (11.05 g), reacted at 80 ° C. for about 3 hours, then added with 16.24 g of 2-methacryloyloxyisocyanate, and further reacted for about 3 hours. As a result, a resin (α1) having a number average molecular weight of about 8000, in which the terminal is a methacrylic group (the average number of polymerizable unsaturated groups in the molecule is about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 2: Preparation of resin (α2)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) was added with 413.72 g and g and 9.52 g of tolylene diisocyanate, reacted at 80 ° C. for about 3 hours, then added with 8.21 g of 2-methacryloyloxyisocyanate, and further reacted for about 3 hours. Thus, a resin (α2) having a number average molecular weight of about 16000 having a methacrylic group at the end (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 3: Preparation of resin (α3)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) was added to 413.72 g and g and tolylene diisocyanate 11.81 g, and reacted at 80 ° C. for about 3 hours, and then added with 4.13 g of 2-methacryloyloxyisocyanate and further reacted for about 3 hours. Thus, a resin (α3) having a number average molecular weight of about 32,000 having a terminal methacrylic group (an average of about 2.0 polymerizable unsaturated groups per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 4: Preparation of resin (α4)]
“X-22-160AS” (number average molecular weight 935, OH value 120), which is a double-ended carbinol-modified reactive silicone oil manufactured by Shin-Etsu Chemical Co., Ltd., in a 1 L separable flask equipped with a thermometer, a stirrer and a reflux condenser. 0.0) and 57.63 g and tolylene diisocyanate 103.04 g were added and reacted at 80 ° C. for about 3 hours, followed by addition of 8.83 g of 2-methacryloyloxyisocyanate and about 3 hours. By reacting, a resin (α4) having a number average molecular weight of about 24,000 having a terminal methacrylic group (an average of about 2.0 polymerizable unsaturated groups per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 5: Preparation of resin (α5)]
“X-22-160AS” (number average molecular weight 935, OH value 120), which is a double-ended carbinol-modified reactive silicone oil manufactured by Shin-Etsu Chemical Co., Ltd., in a 1 L separable flask equipped with a thermometer, a stirrer and a reflux condenser. 0.0) was added to 579.63 g and g and tolylene diisocyanate 98.15 g, reacted at 80 ° C. for about 3 hours, and then added with 17.53 g of 2-methacryloyloxyisocyanate for about 3 hours. By reacting, a resin (α5) having a number average molecular weight of about 12000 having a methacrylic group at the end (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 6: Preparation of resin (α6)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) was added to 413.72 g and g and tolylene diisocyanate (11.05 g), reacted at 80 ° C. for about 3 hours, then added with 5.49 g of 2-methacryloyloxyisocyanate, and further reacted for about 3 hours. Thus, a resin (α6) having a number average molecular weight of about 24,000 having a methacrylic group at the end (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 7: Preparation of resin (α7)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) (413.72 g) and tolylene diisocyanate (12.58 g) were added and reacted at 80 ° C. for about 3 hours, followed by addition of 2.76 g of 2-methacryloyloxyisocyanate and reaction for about 3 hours. Thus, a resin (α7) having a number average molecular weight of about 48,000, which is terminated with a methacryl group (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 8: Preparation of resin (α8)]
“BY16-004” (number average molecular weight 7000, OH value 15), a 1 L separable flask equipped with a thermometer, a stirrer, and a reflux condenser, which is a double-ended carbinol-modified reactive silicone oil manufactured by Toray Dow Corning. .2) was added with 369.72 g and tolylene diisocyanate 8.04 g and reacted at 80 ° C. for about 3 hours, then 6.51 g of 2-methacryloyloxyisocyanate was added, and further reacted for about 3 hours. Thus, a resin (α8) having a number average molecular weight of about 24,000, which has a methacrylic group at the end (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 9: Preparation of resin (α9)]
A 1-liter separable flask equipped with a thermometer, a stirrer, and a refluxer is “KF-6003” (number average molecular weight 5100, OH value 22.2. 0) was 336.54 g, 165.76 g of the trademark “PCDL T4672” (number average molecular weight 2018, OH value 55.6), which is a polycarbonate diol manufactured by Asahi Kasei Co., Ltd., and 22.0 g of tolylene diisocyanate were added. After reacting for about 3 hours under heating, 6.78 g of 2-methacryloyloxyisocyanate was added, and the reaction was further continued for about 3 hours, and the terminal was a methacrylic group (the number of polymerizable unsaturated groups in the molecule per molecule). A resin (α9) having a number average molecular weight of about 24,000 was prepared (average of about 2.0). This resin contains a siloxane bond in the main chain, is syrupy at 20 ° C., flows when an external force is applied, and does not recover its original shape even when the external force is removed.

[Production Example 10: Preparation of resin (α10)]
A 2 L separable flask equipped with a thermometer, a stirrer, and a refluxer is a polycarbonate diol manufactured by Asahi Kasei Co., Ltd., a trademark “PCDL T4672” (number average molecular weight 2059, OH number 54.5) 1318 g and tolylene diisocyanate 18. After adding 4 g and reacting at 80 ° C. for about 3 hours, 141.0 g of 2-methacryloyloxyisocyanate was added, and the reaction was further continued for about 3 hours. A resin (α10) having a number average molecular weight of about 2500 having an average of about 1.7 saturated groups per molecule) was prepared. 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 11: Preparation of resin (α11)]
Trade name “PCDL T4672” (number average molecular weight 2059, OH number 54.5) 1318.0 g and tolylene diisocyanate which is a polycarbonate diol manufactured by Asahi Kasei Co., Ltd. in a 2 L separable flask equipped with a thermometer, a stirrer, and a reflux condenser. After adding 51.9 g and reacting at 80 ° C. for about 3 hours, adding 90.3 g of 2-methacryloyloxyisocyanate and further reacting for about 3 hours, the terminal is a methacrylic group (intramolecular polymerization). A resin (α11) having a number average molecular weight of about 4000 having an average of about 1.7 unsaturated unsaturated groups per molecule) was prepared. 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 12: Preparation of resin (α12)]
A 2 L separable flask equipped with a thermometer, a stirrer, and a refluxer is a polycarbonate diol manufactured by Asahi Kasei Co., Ltd., trademark “PCDL T4672” (number average molecular weight 2059, OH number 54.5) 1318 g and tolylene diisocyanate 76. After adding 8 g and reacting at 80 ° C. for about 3 hours, 52.6 g of 2-methacryloyloxyisocyanate was added, and further reacted for about 3 hours, and the terminal was a methacrylic group (polymerizable non-polymerizable in the molecule). A resin (α12) having a number average molecular weight of about 7000 having an average of about 1.7 saturated groups per molecule) was prepared. 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 13: Preparation of resin (α13)]
Poly (3-methyl-1,5-pentanediol adipate) diol (number average molecular weight 3032, OH number 37.0) and polyoxyethylene (EO) in a 2 L separable flask equipped with a thermometer, stirrer and reflux ) -Oxypropylene (PO) block copolymerized diol (number average molecular weight 2550, OH number 44.0, EO content 30 wt%) 1000 g each and tolylene diisocyanate 148.6 g were added and heated at 80 ° C. for about 3 hours. After the reaction, 436.0 g of poly (oxypropylene) glycol monomethacrylate (number average molecular weight 380) was added, and the reaction was further continued for about 3 hours, and the terminal was a methacrylic group (the polymerizable unsaturated group in the molecule was A resin (α13) having a number average molecular weight of about 17,000 (average of about 1.7 per molecule) was prepared. 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 14: Preparation of resin (α14)]
Poly (3-methyl-1,5-pentanediol adipate) diol (number average molecular weight 3161, OH value 35.5) 514.30 g manufactured by Kuraray Co., Ltd. in a 2 L separable flask equipped with a thermometer, a stirrer and a reflux condenser. And 24.43 g of tolylene diisocyanate were added and reacted at 80 ° C. for about 3 hours, then 6.96 g of 2-methacryloyloxyisocyanate was added, and the reaction was further continued for about 3 hours. A resin (α14) having a number average molecular weight of about 24,000 (average number of polymerizable unsaturated groups in the molecule of about 2.0 per molecule) was prepared. 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.
Table 1 summarizes the compositions and physical properties of the compounds and resins used in the above production examples.

[Example 1]
As a photopolymerization initiator (c), 0.8 parts by mass of benzophenone (abbreviated as BP), which is a hydrogen abstraction type photopolymerization initiator, is added to 100 parts by mass of the resin (α1) as the resin (a). 3.0 parts by mass of 2,2-dimethoxy-2-phenylacetophenone (abbreviated as DMPAP) as a photopolymerization initiator was added. Further, 0.9 parts by mass of 2,6-di-t-butyl-4-methylphenol (abbreviated as DBMP) and bis (1,2,2,6,6-pentamethyl-4-piperidyl) as other additives 1.5 parts by mass of sebacate (abbreviated as BPPS), and 7.7 parts by mass of “Syrosphere C-1504” manufactured by Fuji Silysia Chemical Ltd. were added (number average particle diameter 4.5 μm, specific surface area 520 m ² / g, average pore diameter 12 nm, pore volume 1.5 ml / g, loss on ignition 2.5 wt%, oil absorption 290 ml / 100 g, sphericity of Cyclosphere C-1504, an added porous spherical silica, is scanned When observed with a scanning electron microscope, almost all particles were 0.9 or more), and a liquid resin composition (A1) was produced at 20 ° C.
The viscosity of the resin composition (A1) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A1) was molded on the support and laser engraved by the above-described method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 2]
A liquid resin composition (A2) was produced at 20 ° C. in the same manner as in Example 1 except that the resin (α2) was used as the resin (a).
The viscosity of the resin composition (A2) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
Molding of the resin composition (A2) on the support and laser engraving were performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 3]
A liquid resin composition (A3) was produced at 20 ° C. in the same manner as in Example 1 except that the resin (α3) was used as the resin (a).
The viscosity of the resin composition (A3) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A3) was molded and laser engraved on the support by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 4]
A liquid resin composition (A4) was produced at 20 ° C. in the same manner as in Example 1 except that the resin (α4) was used as the resin (a).
The viscosity of the resin composition (A4) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
Molding of the resin composition (A4) on the support and laser engraving were performed by the above-described method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 5]
Addition of 33 parts by mass of phenoxyethyl methacrylate (abbreviated as POH) as organic compound (b) to 100 parts by mass of resin (α4) as resin (a), and hydrogen abstraction type photopolymerization as photopolymerization initiator (c) 0.8 parts by mass of benzophenone (abbreviated as BP) as an initiator was added, and 3.0 parts by mass of 2,2-dimethoxy-2-phenylacetophenone (abbreviated as DMPAP) as a decay type photopolymerization initiator was added. . Further, 0.96 parts by mass of 2,6-di-t-butyl-4-methylphenol and 1.5% of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate as other additives The resin composition (A5) which was liquid at 20 ° C. was added by adding 7.7 parts by mass of the trademark “Pyrospher C-1504” manufactured by Fuji Silysia Chemical Co., Ltd. used in Example 1.
The viscosity of the resin composition (A5) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A5) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 15. There was almost no ink remaining on the printing plate.

[Example 6]
A liquid resin composition (A6) was produced at 20 ° C. in the same manner as in Example 5 except that the resin (α5) was used as the resin (a).
The viscosity of the resin composition (A6) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A6) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 15. There was almost no ink remaining on the printing plate.

[Example 7]
A liquid resin composition (A7) was produced at 20 ° C. in the same manner as in Example 5 except that the resin (α6) was used as the resin (a).
The viscosity of the resin composition (A7) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A7) was applied to the support and laser engraving was performed by the method described above. Although the relief depth was 0.5 mm and the dot shape was conical, some liquid engraving residue was generated.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 8]
A liquid resin composition (A8) was produced at 20 ° C. in the same manner as in Example 7 except that Cyrossphere C-1504 of Example 7 was not added.
The viscosity of the resin composition (A8) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A8) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 9]
A liquid resin composition (A9) was produced at 20 ° C. in the same manner as in Example 5 except that the resin (α7) was used as the resin (a).
The viscosity of the resin composition (A9) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A9) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 10]
A liquid resin composition (A10) was produced at 20 ° C. in the same manner as in Example 5 except that the resin (α8) was used as the resin (a).
The viscosity of the resin composition (A10) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A10) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 11]
A liquid resin composition (A11) was produced at 20 ° C. in the same manner as in Example 5 except that the resin (α9) was used as the resin (a).
The viscosity of the resin composition (A11) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A11) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 12. There was almost no ink remaining on the printing plate.

[Example 12]
10 parts by mass of trimethylolpropane trimethacrylate (abbreviated as TMPT) as an organic compound (b) is added to 100 parts by mass of the resin (α6) as the resin (a), and hydrogen is used as the photopolymerization initiator (c). 0.8 parts by mass of benzophenone, which is a pull-out type photopolymerization initiator, was added, and 3.0 parts by mass of 2,2-dimethoxy-2-phenylacetophenone, which was a decay type photopolymerization initiator, was added. Further, 0.96 parts by mass of 2,6-di-t-butyl-4-methylphenol and 1.5% of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate as other additives The resin composition (A12) which was liquid at 20 degreeC was added by adding 7.7 mass parts of the trademark "Pyrospher C-1504" made by Fuji Silysia Chemical Co., Ltd. used in Example 1 in mass parts.
The viscosity of the resin composition (A12) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A12) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 10. There was almost no ink remaining on the printing plate.

[Example 13]
Example 12 except that 4.5 parts by mass of “light ester FM-108” manufactured by Kyoeisha Co., Ltd., which is a fluorine-containing compound, was added to 100 parts by mass of the resin (a) to the resin composition of Example 12. Similarly, a liquid resin composition (A13) was produced at 20 ° C.
The viscosity of the resin composition (A13) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A13) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 5. There was almost no ink remaining on the printing plate.

[Example 14]
In the resin composition of Example 12, “Light Ester S” manufactured by Kyoeisha Co., Ltd., which is a compound having a C10 or higher carbon chain and a polymerizable unsaturated group, was added to 4.5 parts by weight of resin (a). A liquid resin composition (A14) was produced at 20 ° C. in the same manner as in Example 12 except that mass part was further added.
The viscosity of the resin composition (A14) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A14) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 5. There was almost no ink remaining on the printing plate.

[Example 15]
In the same manner as in Example 12, except that 4.5 parts by mass of “paraffin wax 115” manufactured by Nippon Seisaku Co., Ltd. was added to 100 parts by mass of the resin (a) to the resin composition of Example 12, at 20 ° C. A liquid resin composition (A15) was prepared.
The viscosity of the resin composition (A15) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A15) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets in the ink repellency evaluation was 5. There was almost no ink remaining on the printing plate.

[Comparative Example 1]
Benzophenone, which is a hydrogen abstraction type photopolymerization initiator, is added as a photopolymerization initiator (c) by adding 50 parts by mass of phenoxyethyl methacrylate as an organic compound (b) to 100 parts by mass of the resin (α10) as the resin (a). 0.5 parts by mass was added, and 2.0 parts by mass of 2,2-dimethoxy-2-phenylacetophenone, which is a decay type photopolymerization initiator, was added. Further, 0.66 parts by mass of 2,6-di-t-butyl-4-methylphenol and 1.0% of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate as other additives 7.7 parts by mass of a trade mark “Pyrospher C-1504” manufactured by Fuji Silysia Chemical Co., Ltd. used in Example 1 was added to prepare a resin composition that is liquid at 20 ° C. (A16).
The viscosity of the resin composition (A16) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A16) was applied to the support and laser engraving was performed by the above method. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 35 sheets. Significant ink residue was observed on the plate surface.

[Comparative Example 2]
A liquid resin composition (A17) was produced at 20 ° C. in the same manner as in Comparative Example 1 except that the resin (α11) was used as the resin (a).
The viscosity of the resin composition (A17) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A17) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 35 sheets. Significant ink residue was observed on the plate surface.

[Comparative Example 3]
Benzophenone, which is a hydrogen abstraction type photopolymerization initiator, is added as a photopolymerization initiator (c) by adding 50 parts by mass of phenoxyethyl methacrylate as an organic compound (b) to 100 parts by mass of the resin (α12) as the resin (a). 0.8 parts by mass was added, and 3.0 parts by mass of 2,2-dimethoxy-2-phenylacetophenone, which is a decay type photopolymerization initiator, was added. Further, 0.96 parts by mass of 2,6-di-t-butyl-4-methylphenol and 1.5% of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate as other additives Part by mass, manufactured by Shin-Etsu Chemical Co., Ltd., 1.5 parts by mass of methylstyryl-modified silicone oil (trademark “KF-410”), manufactured by Fuji Silysia Chemical Ltd., used in Example 1, trademark “Syrosphere C-1504” Was added at a temperature of 20 ° C. to prepare a liquid resin composition (A18).
The viscosity of the resin composition (A18) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A18) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 30 sheets. Some residual ink was observed on the plate surface.

[Comparative Example 4]
A liquid resin composition (A19) was produced at 20 ° C. in the same manner as in Comparative Example 3 except that the resin (α13) was used as the resin (a).
The viscosity of the resin composition (A19) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A19) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 35 sheets. Significant ink residue was observed on the plate surface.

[Comparative Example 5]
A liquid resin composition (A20) was produced at 20 ° C. in the same manner as in Comparative Example 3 except that the resin (α14) was used as the resin (a).
The viscosity of the resin composition (A20) measured with a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A20) was applied to the support and laser engraving was performed by the method described above. The relief depth was 0.5 mm, and the dot shape was conical.
The number of printed sheets for the ink repellency evaluation was 30 sheets. Significant ink residue was observed on the plate surface.

[Comparative Example 6]
In the same manner as in Comparative Example 3, except that the addition amount of “KF-410” in Comparative Example 3 was 7.7 parts by mass with respect to 100 parts by mass of the resin (a), a resin composition liquid at 20 ° C. ( A21) was prepared.
The viscosity of the resin composition (A21) measured using a B-type viscometer was 3000 Pa · s or less at 20 ° C.
The resin composition (A21) was applied to the support by the above method, but engraving was stopped because silicone oil bleeded out on the surface of the printing original plate after curing.
The compositions and test results of the above Examples and Comparative Examples are summarized in Table 2.
By engraving a printing original plate using a resin (a) having a polymerizable unsaturated group having a main chain having a siloxane bond and having a number average molecular weight of 500 to 300,000, and a photopolymerization initiator (c), an ink is obtained. A printing original plate excellent in the stain suppression effect was obtained.
Further, a resin (a) having a polymerizable unsaturated group having a main chain having a siloxane bond and having a number average molecular weight of 500 to 300,000, an organic compound having a polymerizable unsaturated group having a number average molecular weight of less than 1000 (b ), By engraving the printing original plate using the resin composition for laser engraving printing original plate containing the photopolymerization initiator (c), a printing original plate excellent in ink stain suppression effect was obtained in a short time.
Moreover, the mechanical physical property of the printing original plate improved by including a carbonate bond in resin (a).
Moreover, the ink smear suppression effect was further improved by including a fluorine-containing compound, a compound having a C10 or higher carbon chain and a polymerizable unsaturated group, and a wax.

According to the present invention, a resin containing a siloxane bond in the main chain, and a resin composition containing the resin are capable of producing a printing original plate for obtaining a printing plate having excellent ink repellency and excellent ink smudge suppression effect. . Further, the printing original plate can form a printing plate by directly forming a concave / convex pattern by laser engraving.
In addition, such printing plates are particularly suitable for flexographic printing when using solvent ink and film, which have a relatively fast ink drying speed, and when using water-based ink and paper, where the resin in the ink is relatively easy to accumulate. Suitable, the ink stain on the plate is suppressed, and the printing accuracy is greatly improved.

Claims (20)

  A resin composition for a laser engraving printing original plate containing a resin (a) containing a siloxane bond in the main chain and having a number average molecular weight of 500 or more and 300,000 or less.   The resin composition for a laser engraving printing original plate according to claim 1, wherein the resin (a) has a polymerizable unsaturated group.   Furthermore, the resin composition for laser engraving printing original plates of Claim 1 or 2 containing a photoinitiator (c).   The resin composition for a laser engraving printing original plate according to any one of claims 1 to 3, wherein the resin composition further contains an organic compound (b) having a polymerizable unsaturated group and a number average molecular weight of less than 1000. .   5. The resin composition for laser engraving printing original plate according to claim 1, wherein the number average molecular weight of the repeating unit having a siloxane bond contained in the resin (a) is 1,000 or more and 10,000 or less.   6. The resin composition for laser engraving printing original plate according to claim 1, wherein the number average molecular weight of the repeating unit having a siloxane bond contained in the resin (a) is 2,000 or more and 7,000 or less.   The laser engraving printing original plate according to any one of claims 1 to 6, wherein the resin (a) is a resin having at least one chemical bond selected from the group consisting of a carbonate bond, a urethane bond, and an ester bond. Resin composition.   The resin composition for a laser engraving printing original plate according to any one of claims 4 to 7, wherein 20% by mass or more of the total amount of the organic compound (b) is an alicyclic derivative and / or an aromatic derivative.   The resin composition for laser engraving printing original plate according to any one of claims 3 to 8, wherein the photopolymerization initiator (c) contains a hydrogen abstraction type photopolymerization initiator and / or a decay type photopolymerization initiator.   The resin composition for a laser engraving printing original plate according to any one of claims 1 to 9, which is liquid at 20 ° C.   The inorganic fine particles having a number average particle diameter of 0.01 μm or more and 10 μm or less further include 1 to 100 parts by mass with respect to 100 parts by mass of the resin composition for laser engraving printing original plate. The resin composition for laser engraving printing original plate as described in Item 1.   A step of forming the laser engraving printing precursor resin composition according to any one of claims 1 to 11 on a support in a sheet form or a cylindrical form, and irradiating the formed resin composition with a high energy active ray. A method for producing a laser engraving printing original plate including a curing step.   A leather engraving printing original plate obtainable by curing the resin composition for a laser engraving printing original plate according to any one of claims 1 to 11.   The laser engraving printing original plate according to claim 13, further comprising a support on the non-printing surface side of the laser engraving printing original plate.   The laser engraving printing original plate according to claim 14, wherein the support is a hollow cylindrical support.   The laser engraving printing original plate according to claim 14 or 15, further comprising one or more cushion layers between the laser engraving printing original plate and the support.   The laser engraving printing original plate according to claim 16, wherein the cushion layer includes hollow microcapsules.   The laser engraving printing original plate according to any one of claims 15 to 17, further comprising one or more circumferential length adjusting layers between the laser engraving printing original plate and the hollow cylindrical support.   The laser engraving printing original plate according to any one of claims 13 to 18, wherein the outermost surface of the laser engraving printing original plate is surface-adjusted by at least one method selected from cutting, grinding, and polishing.   A printing plate obtained by laser engraving the printing original plate according to any one of claims 13 to 19.