JP4306257B2 - Printing plate material and printing method - Google Patents

Description

【０１４２】
〈基材２〉
水系塗布液用の下引き層が形成された厚さ１７５μｍのＰＥＴフィルム（ＨＳ７４、帝人社製）を用いた。
【０１４３】
〈基材３〉
厚さ０．２４ｍｍのアルミニウム板（材質１０５０、調質Ｈ１６）を、５０℃の１質量％水酸化ナトリウム水溶液中に浸漬し、溶解量が２ｇ／ｍ²になるように溶解処理を行い、水洗した後、２５℃の０．１質量％塩酸水溶液中に３０秒間浸漬し、中和処理した後、水洗した。
【０１４４】
次いで、このアルミニウム板を塩酸１０ｇ／Ｌ、アルミを０．５ｇ／Ｌ含有する電解液により、正弦波の交流を用いて、ピーク電流密度が５０Ａ／ｄｍ²の条件で電解粗面化処理を行った。この際の電極と試料表面との距離は１０ｍｍとした。電解粗面化処理は１２回に分割して行い、一回の処理電気量（陽極時）を３０Ｃ／ｄｍ²とし、合計で３６０Ｃ／ｄｍ²の処理電気量（陽極時）とした。また、各回の粗面化処理の間に５秒間の休止時間を設けた。
【０１４５】
電解粗面化後は、５０℃に保たれた１質量％水酸化ナトリウム水溶液中に浸漬して、粗面化された面のスマットを含めた溶解量が２ｇ／ｍ²になるようにエッチングし、水洗し、次いで２５℃に保たれた１０％硫酸水溶液中に１０秒間浸漬し、中和処理した後、水洗した。次いで、２０％硫酸水溶液中で、２０Ｖの定電圧条件で電気量が１５０Ｃ／ｄｍ²となるように陽極酸化処理を行い、更に水洗した。
【０１４６】
次いで、水洗後の表面水をスクイーズした後、７０℃に保たれた１質量％の３号ケイ酸ソーダ水溶液に３０秒間浸漬し、水洗を行った後に８０℃で５分間乾燥し、基材３を得た。基材３のＲａは４００ｎｍであった（ＷＹＫＯ社製ＲＳＴ Ｐｌｕｓを使用し、４０倍で測定した）。
【０１４７】
《層Ａの塗布液の作製》
表１、２に示す組成の素材を十分に撹拌、混合した後、濾過して層Ａ−１〜５（層Ａ−３は比較）の塗布液を作製した。
【０１４８】
【表１】

【０１４９】
【表２】

【０１５０】
《親水性である層Ｂの塗布液の作製》
表３、４に示す組成の素材をホモジナイザを用いて十分に撹拌、混合した後、濾過して親水性である層Ｂ−１〜４（層Ｂ−３は比較）の塗布液を作製した。
【０１５１】
【表３】

【０１５２】
【表４】

【０１５３】
〔印刷版材料の作製〕
表５に示した基材と塗布液との組み合わせで、層Ａ、層Ｂの各塗布液をワイヤーバーで表に示した乾燥付量となるように塗布して、本発明及び比較の印刷版材料を作製した。また、作製した印刷版材料がポジタイプ（露光した部分が非画像部となる）であるか、ネガタイプ（露光した部分が画像部となる）であるかも表５に記した。層Ａ、層Ｂの乾燥条件は５５℃、３分間で行い、層Ｂを塗布形成した後に、４０℃、７２時間のエイジングを行った。
【０１５４】
《画像形成》
画像形成は赤外線レーザー露光により行った。露光には波長８３０ｎｍ、スポット径約１８μｍのレーザービームを用い、レーザービームの焦点を印刷版材料表面に合わせて、露光エネルギーを３００ｍＪ／ｃｍ²として、２４００ｄｐｉ（ｄｐｉとは１インチ、即ち２．５４ｃｍあたりのドット数を表す）、１７５線で画像を形成した。評価用の画像として、未露光部、ベタ露光画像と１〜９９％の網点露光画像を用いた。
【０１５５】
《印刷方法》
〈印刷方法１〉
印刷機：三菱重工業（株）製ＤＡＩＹＡ１Ｆ−１の版胴に印刷版材料を取り付け、コート紙、湿し水（アストロマーク３（日研化学研究所製））２質量％、インク（東洋インキ社製ＴＫハイユニティーＭ紅）を使用して印刷を行った。印刷開始のシークエンスはＰＳ版の印刷シークエンス（版胴を回転させた後、水供給ロールを版面に接触させて３回転させ、次いでインク供給ロールを版面に接触させた時点で、紙が圧胴に供給されて胴が入って印刷が開始される）で行い、特別な機上現像操作は行わなかった。
【０１５６】
〈印刷方法２〉
印刷開始のシークエンスとして、版胴を回転させた後、インク供給ロールを版面に接触させて３回転させ、次いで水供給ロールを版面に接触させて２回転させた時点で、紙が圧胴に供給されて胴が入って印刷が開始されるというシークエンスを用いた以外は、印刷方法１と同様にして印刷を行った。
【０１５７】
〈刷り出し性、地汚れ〉
刷り出し時、良好なＳ／Ｎ（非画像部に地汚れがなく、且つ画像部網点画像が良好に再現され、ベタ濃度が適正範囲となっている）を有した印刷物が得られるまでの印刷枚数を評価した。結果を表５に示した。なお、表中の記号は下記の評価結果を示している。また、刷り出し１００枚時点での非画像部の地汚れの有無も同時に評価した。結果を表５に示した。これらの評価を印刷方法１と印刷方法２とで行った。
【０１５８】
◎：２０枚未満
○：２０枚以上５０枚未満
△：５０枚以上１００枚未満
×：１００枚以上
〈スクラッチ汚れ耐性〉
露光済の印刷版材料サンプルの非画像部に、印刷前にＨＥＩＤＯＮ試験機を用いて荷重を変化させてスクラッチ跡をつけておき、印刷開始から１００枚目の時点でどの荷重までが汚れとなっていないかを評価した。触針には０．３ｍｍφのサファイア針を用いた。結果を表５に示した。なお、表中の記号は下記の評価結果を示している。
【０１５９】
◎：１５０ｇ以上
○：１００ｇ以上、１５０ｇ未満
△：５０ｇ以上１００ｇ未満
×：５０ｇ未満
【０１６０】
【表５】

【０１６１】
表５から、参考例の印刷版材料は良好な刷り出し性を有し、スクラッチ汚れ耐性も高く、且つ非画像部の地汚れもないことがわかる。
【０１６２】
実施例２
《親油性である層Ｂの塗布液の作製》
表６に示す組成の素材を十分に撹拌、混合した後、濾過して層Ｂ−５〜８の塗布液を作製した。
【０１６３】
【表６】

【０１６４】
〔印刷版材料の作製〕
表７に示した基材と塗布液を組み合わせ、各層をワイヤーバーで表に示した乾燥付量となるように塗布して、本発明及び比較の印刷版材料を作製した。印刷版材料のタイプはすべてネガタイプである。各層の乾燥条件は５５℃、３分間で行い、全層塗布形成した段階で４０℃、７２時間のエイジングを行った。
【０１６５】
《画像形成》
画像形成は赤外線レーザー露光により行った。露光には波長８３０ｎｍ、スポット径約１８μｍのレーザービームを用い、レーザービームの焦点を印刷版材料表面に合わせて、露光エネルギーを３５０ｍＪ／ｃｍ²とした条件で、２４００ｄｐｉ、１７５線で画像を形成した。評価用の画像として、ベタ露光画像と１〜９９％の網点露光画像を用いた。
【０１６６】
《印刷方法》
実施例１と同様にして行った。
【０１６７】
〈刷り出し性，地汚れ〉
実施例１と同様にして行った。結果を表７に示した。
【０１６８】
〈スクラッチ汚れ耐性〉
実施例１と同様にして行った。結果を表７に示した。
【０１６９】
〈耐刷性〉
印刷を２万枚まで行って、３％網点画像に欠けが生じるか、もしくはベタ画像部にかすれが生じた時点での印刷枚数を求めた。結果を表７に示した。
【０１７０】
【表７】

【０１７１】
表７からわかるように、本発明の印刷版材料はアルミニウム板を基材として用いた場合であっても良好な性能が得られることがわかる。
【０１７２】
【発明の効果】
本発明により、汎用サーマルプロセスレスプレートとして十分な刷り出し性、スクラッチ汚れ耐性、非画像部の地汚れ及び耐刷性とを有した印刷版材料の提供及び該印刷版材料を用いた印刷方法の提供を可能とした。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing plate material and a printing method, and more particularly to a printing plate material capable of forming an image by a computer-to-plate (CTP) method and a printing method of a printing plate material having an image formed by a CTP method.
[0002]
[Prior art]
With the digitization of print data, there is a need for CTPs that are inexpensive, easy to handle, and have the same printability as PS plates. In particular, in recent years, a development process using a special chemical agent is unnecessary, and it can be applied to a printing machine having a direct imaging (DI) function, and is a general-purpose type thermal processless plate having the same usability as a PS plate. Expectations are growing.
[0003]
As a thermal processless plate for DI, for example, Thermo Lite manufactured by Agfa Co., Ltd. is mentioned, but it requires on-machine development operation, and printing performance when printing is started with the same printing press sequence as the PS plate Is insufficient. In addition, scratch resistance of the printing plate (scratched parts become printing stains) is low, and sufficient consideration is required for handling. Furthermore, it cannot be said that the printing durability is sufficient.
[0004]
On the other hand, a general-purpose thermal processless plate requires a printability that can be printed without changing the printing conditions of the PS plate (of course, without requiring on-machine development operations). In addition, it is scratch stain resistance and printing durability in handling within the range of common sense.
[0005]
A laser having a wavelength of near infrared to infrared is mainly used for image formation of a thermal processless plate. Thermal processless plates capable of image formation by this method are roughly classified into an ablation type described later and a thermal fusion image layer on-machine development type.
[0006]
Examples of the ablation type are described in JP-A-8-507727, JP-A-6-186750, JP-A-6-199064, JP-A-7-314934, JP-A-10-58636, and JP-A-10-244773. The thing that is.
[0007]
In these, for example, a hydrophilic layer and a lipophilic layer are laminated on a base material with either layer as a surface layer. If the surface layer is a hydrophilic layer, it is possible to form an image portion by exposing it like an image, ablating the hydrophilic layer and removing it like an image to expose the lipophilic layer. However, since contamination inside the exposure apparatus due to the scattered material on the ablated surface layer becomes a problem, a further water-soluble protective layer is provided on the hydrophilic layer to prevent the ablated surface layer from being scattered and together with the protective layer on the printing press. A method for removing the ablated surface layer has also been proposed.
[0008]
In the case of the ablation type, it shows a relatively good performance with respect to scratch stain resistance, but the improvement in printing durability is related to increasing the strength of the surface layer. Since the resolution is lowered, it is very difficult to improve the printing durability while balancing these.
[0009]
On the other hand, as the development type on the heat fusion image layer machine, as disclosed in Japanese Patent No. 2938397, the thermoplastic fine particles and the water-soluble binder are added to the image forming layer on the hydrophilic layer or the aluminum grain. What was used is mentioned. The above-mentioned Thermo Lite manufactured by Agfa is a thermal processless plate of this type.
[0010]
In order to improve the printability with this type, a method of increasing the ratio of the water-soluble binder in the image forming layer can be considered, but the water-soluble binder is increased to a ratio that improves the printability. If it does, it will result in inhibiting the heat-fusibility of a thermoplastic microparticle, and coexistence with image formation is very difficult.
[0011]
Further, in order to improve scratch stain resistance, it is necessary to prevent collapse of the thermoplastic fine particles due to pressure and deterioration of on-press developability due to pressure bonding. The method of increasing the ratio of the agent or the method of increasing the Tg of the thermoplastic fine particles to make the particles harder also inhibits image formation, which is also very compatible with image formation, that is, printing durability. Have difficulty.
[0012]
On the other hand, JP-A-2002-19318 improves handling by providing an overcoat layer of water-soluble celluloses on an image forming layer having hydrophobized precursor fine particles such as thermoplastic fine particles. A printing plate material has been proposed (see, for example, Patent Document 1). However, with such a configuration, although handling is improved, ink deposition on the image area at the time of printing is delayed, while on-machine developability of the unexposed area is also deteriorated, resulting in an increase in paper loss. become. Further, since the overcoat layer does not contribute to the improvement of the strength of the image area, it cannot be expected to improve the printing durability.
[0013]
In addition, a printing plate material in which the overcoat layer is a water-swellable resin in which a water-soluble resin is partially cross-linked has been presented (see, for example, Patent Documents 2 and 3). The point that printing durability is not sufficient remains as a problem.
[0014]
As described above, with the conventional technology, it has been very difficult to impart sufficient printability, scratch stain resistance, and printing durability to the thermal processless plate.
[0015]
[Patent Document 1]
JP 2002-19318 A
[0016]
[Patent Document 2]
JP 2002-86948 A
[0017]
[Patent Document 3]
JP 2002-86949 A
[0018]
[Problems to be solved by the invention]
An object of the present invention is to provide a printing plate material having sufficient printability as a general-purpose thermal processless plate, scratch stain resistance, non-image area background stain and printing durability, and using the printing plate material. Provided a printing method.
[0019]
[Means for Solving the Problems]
The above object of the present invention has been achieved by the following constitution.
[0020]
  1) In a printing plate material having a layer A and a layer B in order on a base material and containing a photothermal conversion material in any of the layers provided on the base material, the layer A is heated by infrared laser exposure. Layer that improves mechanical strength, layer BWaterInsoluble and does not swellLipophiliclayerThe surface of the base material or the surface of the layer formed adjacent to the base material side of layer A is hydrophilic.A printing plate material characterized by
[0021]
  2) Layer B isInk fillabilityThe printing plate material as described in 1) above, wherein
[0022]
  3) Layer B isMade of thermosetting resin or thermoplastic resin1) characterized in thatOr 2)The printing plate material described in 1.
[0023]
4) The weight of layer B is 0.1 g / m²Or more, 2.0 g / m²The printing plate material according to any one of 1) to 3) above, which is the following.
[0024]
5) The printing plate material according to any one of 1) to 4) above, wherein the layer A contains thermoplastic fine particles.
[0025]
6) The printing plate material according to any one of 1) to 4) above, wherein the layer A contains a crosslinking agent.
[0026]
7) After exposing the printing plate material according to any one of 1) to 6) above with an infrared laser, a printing operation is performed on the printing machine using dampening water and / or ink to thereby expose an unexposed portion. A printing method comprising removing the layer B and the layer A.
[0027]
8) The printing method as described in 7) above, wherein the ink supply roller contacts the printing plate surface before the water supply roller in the printing operation.
[0028]
9) The printing method as described in 7) or 8) above, wherein the infrared laser exposure is performed on a printing machine.
[0029]
In the printing plate material which has the layer A and the layer B in order on the base material and contains the photothermal conversion material in any of the layers provided on the base material, the layer A is generated by infrared laser exposure. The printing plate material is a layer in which mechanical strength is improved by heat, and the layer B is a layer which is substantially insoluble in water and does not swell.
[0030]
The unexposed portion of layer A is adjusted to a mechanical strength that can be broken by the force received when it comes into contact with the ink roller, water roller, and blanket on the printing press. That is, it is a layer that can be developed on the machine. Layer A may contain a structure whose mechanical strength is lowered by a high-boiling solvent contained in water or ink, for example, a water-soluble or water-swellable material, or a material that dissolves in the high-boiling solvent. . The exposed portion of the layer A is improved in mechanical strength by heat generated by exposure, and the on-press developability is lowered, or more preferably, the mechanical strength is improved so as not to be developed on-press. Examples of the mechanism for improving the strength of layer A by heat include the following two points, but are not limited thereto.
[0031]
(1) The layer A contains thermoplastic fine particles, and the thermoplastic fine particles are fused to each other by heat, or the thermoplastic fine particles and other constituent materials are fused to improve the strength.
[0032]
(2) Layer A contains an unreacted cross-linking agent, and the cross-linking reaction between the cross-linking agent and other constituent materials proceeds by heat, or the self-cross-linking reaction between the cross-linking agents proceeds to improve the strength.
[0033]
The thermoplastic fine particles that can be used in the present invention include the following heat-fusible fine particles or heat-fusible fine particles. In addition, fine particles obtained by compatibilizing or dispersing a photothermal conversion dye described later in a thermoplastic fine particle can be preferably used.
[0034]
The heat-meltable fine particles used in the present invention are fine particles formed of a material that has a low viscosity when melted, and is generally classified as a wax, among thermoplastic materials. The physical properties are preferably a softening point of 40 ° C or higher and 120 ° C or lower, a melting point of 60 ° C or higher and 150 ° C or lower, and a softening point of 40 ° C or higher and 100 ° C or lower, a melting point of 60 ° C or higher and 120 ° C or lower. preferable. When the melting point is less than 60 ° C., storage stability is a problem, and when the melting point is higher than 300 ° C., ink deposition sensitivity is lowered.
[0035]
Usable materials include paraffin, polyolefin, polyethylene wax, microcrystalline wax, fatty acid wax and the like. These have a molecular weight of about 800 to 10,000. In order to facilitate emulsification, these waxes can be oxidized to introduce polar groups such as hydroxyl groups, ester groups, carboxyl groups, aldehyde groups, and peroxide groups. Furthermore, in order to lower the softening point and improve the workability, these waxes are stearamide, linolenamide, laurylamide, myristamide, hardened beef fatty acid amide, palmitoamide, oleic acid amide, rice sugar fatty acid amide, coconut fatty acid. It is also possible to add amides or methylolated products of these fatty acid amides, methylene bisstellaramide, ethylene bisstellaramide and the like. Coumarone-indene resin, rosin-modified phenol resin, terpene-modified phenol resin, xylene resin, ketone resin, acrylic resin, ionomer, and copolymers of these resins can also be used.
[0036]
Among these, it is preferable to contain any of polyethylene, microcrystalline, fatty acid ester, and fatty acid. Since these materials have a relatively low melting point and a low melt viscosity, high-sensitivity image formation can be performed. Further, since these materials have lubricity, damage when a shearing force is applied to the surface of the printing plate material is reduced, and resistance to printing stains due to scratches or the like is improved.
[0037]
The heat-meltable fine particles are preferably dispersible in water, and the average particle diameter is preferably 0.01 to 10 μm, more preferably 0.1 to 3 μm. When the average particle size is smaller than 0.01 μm, when the coating liquid for the layer containing the heat-meltable fine particles is applied onto the porous hydrophilic layer described later, the heat-meltable fine particles are not removed from the pores of the hydrophilic layer. It becomes easy to enter inside or into the gaps between fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause scumming. When the average particle size of the heat-meltable fine particles is larger than 10 μm, the resolution is lowered.
[0038]
Further, the composition of the heat-meltable fine particles may be continuously changed between the inside and the surface layer, or may be coated with a different material. As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used.
[0039]
As content of the heat-meltable fine particle in a layer, 5-90 mass% of the whole layer is preferable, and 10-70 mass% is still more preferable.
[0040]
Examples of the heat-fusible fine particles of the present invention include thermoplastic hydrophobic polymer fine particles, and there is no specific upper limit for the softening temperature of the thermoplastic hydrophobic high-molecular polymer particles, but the temperature is high. It is preferably lower than the decomposition temperature of the coalesced fine particles. The weight average molecular weight (Mw) of the polymer is preferably in the range of 10,000 to 1,000,000.
[0041]
Specific examples of the polymer constituting the polymer particles include, for example, diene (co) polymers such as polypropylene, polybutadiene, polyisoprene, and ethylene-butadiene copolymer, styrene-butadiene copolymer, Synthetic rubbers such as methyl methacrylate-butadiene copolymer, acrylonitrile-butadiene copolymer, polymethyl methacrylate, methyl methacrylate- (2-ethylhexyl acrylate) copolymer, methyl methacrylate-methacrylic acid copolymer, methyl acrylate- ( N-methylolacrylamide) copolymer, (meth) acrylic acid ester such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate-vinyl propionate copolymer, vinyl acetate-ethylene copolymer Vinyl etc. of polymers Ester (co) polymer, vinyl acetate - (2-ethylhexyl acrylate) copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene and copolymers thereof. Of these, (meth) acrylic acid esters, (meth) acrylic acid (co) polymers, vinyl ester (co) polymers, polystyrene, and synthetic rubbers are preferably used. Moreover, the hydrophobic polymer particle which contains more than 0.1 mass% of nitrogen described in Unexamined-Japanese-Patent No. 2002-251005 can also be used preferably.
[0042]
The polymer polymer fine particles may be composed of a polymer polymer polymerized by any known method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method or a gas phase polymerization method. As a method for micronizing a polymer polymer polymerized by a solution polymerization method or a gas phase polymerization method, a method of atomizing a solution in an organic solvent of the polymer polymer into an inert gas and drying to form a microparticle, Examples include a method in which a high molecular polymer is dissolved in an organic solvent immiscible with water, this solution is dispersed in water or an aqueous medium, and the organic solvent is distilled off to form fine particles. In any of the methods, when necessary for polymerization or micronization, as a dispersant or stabilizer, a surfactant such as sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyethylene glycol, or the like, or a water-soluble property such as polyvinyl alcohol. A resin may be used.
[0043]
As the crosslinking agent used in the present invention, a known polyfunctional compound can be used. Examples thereof include polyepoxy compounds, polyamine compounds, polyisocyanate compounds (including isocyanates having a protective group, so-called blocked isocyanates), polyalkoxysilyl compounds, titanate compounds, aldehyde compounds, and polyvalent metal salt compounds. In addition, carbodiimide compounds described in JP-A-7-330849, JP-A-9-309871, JP-A-10-316930, and JP-A-2000-7642 can also be preferably used.
[0044]
Since the mechanical strength of the layer A is required to be on-machine developable as the mechanical strength of the unexposed area, it is preferable that the crosslinking agent as described above is present in the layer unreacted, and only the exposed area. Is preferably crosslinked by heat. For this purpose, it is preferable that the layer A contains a precursor of a reaction accelerator that promotes a crosslinking reaction by exposure.
[0045]
The precursor of the reaction accelerator is converted to a reaction accelerator upon heating, and a reaction accelerator is formed. Suitable precursors for reaction accelerators are, for example, precursors that release acid upon heating. Examples of these precursors include sulfonium compounds disclosed in British Patent No. 612,065, European Patent No. 615,233, and US Pat. No. 5,326,677, particularly benzylsulfonium. Compounds, inorganic nitrates disclosed in EP 462,763, WO 81/1755, US Pat. No. 4,370,401 (for example, Mg (NO_Three)₂・ 6H₂O, ammonium nitrate), organic nitrates (eg, guanidinium nitrate, pyridinium nitrate), compounds that release sulfonic acids disclosed in US Pat. No. 5,312,721 (eg, 3-sulfolenes, 2,5 -Dihydrothio-thiophene-1,1-dioxides), thermally decomposable compounds disclosed in British Patent 1,204,495, amines disclosed in US Pat. No. 3,669,747 Co-crystallizable adducts with volatile organic acids, aralkyl cyanoforms disclosed in US Pat. No. 3,166,583, EP 159,725 and West German Patent 351,576 Thermoacid disclosed in US Pat. No. 5,278,031, a squaric acid generator compound disclosed in US Pat. No. 5,278,031, US Pat. 5,225,314 Pat, Research Disclosure No. of same 5,227,277 Pat and 11 May 1973 11511 is an acid generating compound disclosed in 11511.
[0046]
Further, as another embodiment, there can be mentioned an embodiment in which the crosslinking agent is encapsulated in microcapsules capable of releasing the inclusions by heat, and the microcapsules are dispersed in the layer A. Specifically, a microcapsule as described in JP-A-2002-86948 can be used.
[0047]
Other materials that can be contained in the layer A are as follows.
[0048]
Layer A can contain a binder that maintains the coating state within a range that does not impair on-press developability. As the binder, the following inorganic, organic, and organic-inorganic hybrid binders can be used.
[0049]
As the inorganic binder, a metal oxide colloid can be used. Examples of metal oxide colloids include colloidal silica, alumina sol, titania sol, and other metal oxide sols. The form of the metal oxide colloid may be spherical, needle-like, feather-like, or any other form. As an average particle diameter, it is preferable that it is 3-200 nm, and it is more preferable that it is 20-200 nm. Several kinds of metal oxide colloids having different average particle diameters can be used in combination. The surface treatment may be performed on the surface of the colloidal particles.
[0050]
Moreover, a silicate can also be used as an inorganic binder. The silicate is preferably an alkali metal silicate such as Na silicate, silicate K, or Li silicate, and Na in the silicate is used.₂O (or K₂O, Li₂The content of O) is preferably 0.03 to 10% by mass, more preferably 0.05 to 5% by mass, based on the solid content.
[0051]
In addition, an inorganic polymer or an organic-inorganic hybrid polymer using a metal alkoxide by a so-called sol-gel method can be preferably used. The formation of an inorganic polymer or an organic-inorganic hybrid polymer by the sol-gel method is described in, for example, “Application of the sol-gel method” (Sakuo Sakuo / Agne Jofusha) or in this book Known methods described in the cited documents can be used.
[0052]
As the organic binder, a water-soluble resin or a water-dispersible resin can be used. Examples of water-soluble resins or water-dispersible resins include oligosaccharides, polysaccharides (starch, celluloses, polyuronic acid, pullulan, etc.), polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, styrene- Examples thereof include butadiene copolymer, methyl methacrylate-butadiene copolymer conjugated diene polymer latex, acrylic polymer latex, vinyl polymer latex, polyacrylamide, and polyvinylpyrrolidone.
[0053]
In addition, an acid (phosphoric acid, acetic acid, etc.) or an alkali (sodium hydroxide, sodium phosphate, etc.) may be added to the layer A as a pH adjuster of the coating solution, which is known for the purpose of improving coating properties. A surfactant (preferably Si-based, F-based, or acetylene glycol-based) or an antifoaming agent may be added. Moreover, the photothermal conversion raw material mentioned later can also be added.
[0054]
Since the layer B constituting the printing plate material of the present invention is a layer that is substantially insoluble in water and does not swell, the force applied to the layer B, for example, the tack (peeling) force due to contact with the ink roller Is added to the layer A as it is, and the unexposed part is peeled off from both the layer B and the layer A and transferred into the ink on the ink roller, that is, developed on the machine, and sequentially fills the image portion of the printing plate. Will shift to printing paper.
[0055]
Here, for example, when the layer B is water-soluble or water-swellable, the tack force due to contact with the ink roller is hardly transmitted to the layer A, and as a result, the on-press development of the layer A is delayed. Become.
[0056]
However, if the mechanical strength of the layer B itself is too high, even if the mechanical strength of the layer A is low, the on-press developability deteriorates or the resolution decreases, so the layer B may be a thin layer. preferable. The amount of layer B applied is 0.1 g / m²Or more, 2.0 g / m²Or less, preferably 0.2 g / m²1.0 g / m²The following is more preferable. Specific materials used for the layer B will be described later.
[0057]
As a base material, the well-known material used as a board | substrate of a printing plate can be used. For example, a metal plate, a plastic film, paper treated with a polyolefin, a composite base material obtained by appropriately bonding the above materials, and the like can be given. The thickness of the base material is not particularly limited as long as it can be attached to a printing press, but a thickness of 50 to 500 μm is generally easy to handle.
[0058]
Examples of the metal plate include iron, stainless steel, and aluminum. Aluminum or an aluminum alloy (hereinafter referred to as an aluminum plate) is particularly preferable from the relationship between specific gravity and rigidity. The aluminum plate is usually used after degreasing with an alkali, an acid, a solvent or the like in order to remove oil used during rolling and winding existing on the surface of the aluminum plate. As the degreasing treatment, degreasing with an alkaline aqueous solution is particularly preferable. Moreover, in order to improve adhesiveness with a coating layer, it is preferable to perform an easily bonding process and undercoat layer application | coating to an application surface. For example, a method of dipping in a liquid containing a coupling agent such as a silicate or a silane coupling agent, or applying a liquid and then sufficiently drying may be mentioned. Anodizing treatment is also considered as a kind of easy adhesion treatment and can be used. Moreover, it can also use combining an anodizing process and the said immersion or application | coating process.
[0059]
In addition, an aluminum plate roughened by a known method and a base material combined with the above easy-adhesion treatment can also be used, and the surface is roughened by a known method and anodized, and if necessary. It is also possible to use a so-called aluminum grain having a surface treatment as a base material.
[0060]
Examples of the plastic film include polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polycarbonate, polysulfone, polyphenylene oxide, and cellulose esters. In particular, polyethylene terephthalate and polyethylene naphthalate are preferable. These plastic films are preferably subjected to easy adhesion treatment or undercoat layer coating on the coated surface in order to improve adhesion with the coated layer. Examples of the easy adhesion treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment. Examples of the undercoat layer include a layer containing gelatin or latex. A substrate having a roughened surface of a plastic film can also be used.
[0061]
In addition, as the composite base material, the above materials are used by appropriately bonding them, but they may be bonded before forming the coating layer, or may be bonded after forming the coating layer, immediately before being attached to the printing press. You may stick together.
[0062]
The printing plate material of the present invention contains a photothermal conversion material in any layer formed on a substrate.
[0063]
As the photothermal conversion material, photothermal conversion dyes and photothermal conversion pigments described later can be used. However, since the unexposed portion of the layer A is developed on the machine, the photothermal conversion material is a material that is less colored to visible light. It is preferable that it is a light-colored light-to-heat conversion dye.
[0064]
When the layer A contains a photothermal conversion pigment as a photothermal conversion material, the content thereof is 1 to 30% by mass of the entire layer A, and more preferably 2 to 20% by mass. When layer A contains a photothermal conversion dye as a photothermal conversion material, the content is 0.1 to 20% by mass of the entire layer A, and more preferably 0.5 to 10% by mass.
[0065]
A photothermal conversion pigment and a photothermal conversion dye can also be used in combination. The following can be used as the photothermal conversion dye.
[0066]
General infrared absorbing dyes such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes, organic compounds such as phthalocyanine dyes and naphthalocyanine dyes , Azo, thioamide, dithiol, and indoaniline organometallic complexes. Specifically, JP-A-63-139191, JP-A-64-33547, JP-A-1-160683, JP-A-1-280750, JP-A-1-293342, JP-A-2-2074, JP-A-3-26593, JP-A-3-30991, JP-A-3-34891, JP-A-3-36093, JP-A-3-36094, JP-A-3-36095, JP-A-3-42281, JP-A-3-97589, and JP-A-3-103476 And the compounds described in the above. These can be used alone or in combination of two or more. Moreover, it describes in each gazette of Unexamined-Japanese-Patent No. 11-240270, 11-26562, Unexamined-Japanese-Patent No. 2000-309174, 2002-49147, 2001-162965, 2002-144750, 2001-219667. These compounds can also be preferably used.
[0067]
In the present invention, the photothermal conversion dye itself may be discolored by exposure, and the hue of the image forming layer may be changed to express the distinction between the exposed portion and the unexposed portion, that is, expose visible image quality. The dye preferably has a function of fading due to heat or being discolored by acid or base. Examples of such a photothermal conversion dye include compounds described in JP-A No. 11-240270, but any compound may be used as long as it exhibits the above functions.
[0068]
Preferred examples of the photothermal conversion pigment include carbon, graphite, metal, metal oxide and the like.
[0069]
As carbon, it is particularly preferable to use furnace black or acetylene black. The particle size (d50) is preferably 100 nm or less, and more preferably 50 nm or less.
[0070]
As the graphite, fine particles having a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less can be used.
[0071]
As the metal, any metal can be used as long as the particle diameter is 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less. The shape may be any shape such as a spherical shape, a piece shape, or a needle shape. In particular, colloidal metal fine particles (Ag, Au, etc.) are preferable.
[0072]
As the metal oxide, a material that is black in the visible light region, or a material that has conductivity or is a semiconductor can be used. As the former, black iron oxide (Fe_ThreeO_FourAnd black composite metal oxides containing two or more of the aforementioned metals. Examples of the latter include SnO doped with Sb.₂(ATO), In with Sn added₂O_Three(ITO), TiO₂TiO₂And TiO (titanium oxynitride, generally titanium black) reduced. These metal oxides can also be used as a core material (BaSO_FourTiO₂, 9Al₂O_Three・ 2B₂O, K₂O · nTiO₂Etc.) can also be used. These particle sizes are 0.5 μm or less, preferably 100 nm or less, and more preferably 50 nm or less.
[0073]
Among these photothermal conversion materials, black composite metal oxides containing two or more metals are more preferable materials. Specifically, it is a composite metal oxide composed of two or more metals selected from Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, and Ba. These can be produced by the methods disclosed in JP-A-8-27393, 9-25126, 9-237570, 9-241529, and 10-231441.
[0074]
The composite metal oxide used in the present invention is particularly preferably a Cu-Cr-Mn-based or Cu-Fe-Mn-based composite metal oxide. In the case of a Cu—Cr—Mn system, it is preferable to perform the treatment disclosed in JP-A-8-27393 in order to reduce elution of hexavalent chromium. These composite metal oxides are colored with respect to the amount added, that is, have good photothermal conversion efficiency.
[0075]
These composite metal oxides preferably have an average primary particle diameter of 1 μm or less, and more preferably have an average primary particle diameter in the range of 0.01 to 0.5 μm. When the average primary particle diameter is 1 μm or less, the photothermal conversion ability with respect to the addition amount becomes better, and when the average primary particle diameter is within the range of 0.01 to 0.5 μm, the photothermal conversion ability with respect to the addition amount is obtained. Better. However, the photothermal conversion ability with respect to the addition amount is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better.
[0076]
Therefore, it is preferable to disperse these composite metal oxide particles by a known method before adding them to the layer coating solution to prepare a dispersion (paste). An average primary particle size of less than 0.01 is not preferable because dispersion becomes difficult. A dispersing agent can be appropriately used for the dispersion. The addition amount of the dispersant is preferably 0.01 to 5% by mass, and more preferably 0.1 to 2% by mass with respect to the composite metal oxide particles.
[0077]
There are two types of embodiments of the printing plate material of the present invention.
In the first embodiment, the layer B is hydrophilic, and the surface of the layer formed adjacent to the substrate surface or the substrate side of the layer A is lipophilic.
[0078]
As the base material having an oleophilic surface in this embodiment, the above-mentioned plastic film base material can be preferably used. In particular, an undercoat layer that has ink inking properties and improves the adhesiveness of the layer A is provided. It is preferable to use a plastic substrate.
[0079]
The hydrophilic layer B is preferably configured as follows, but is not limited to this as long as it is a hydrophilic layer.
[0080]
As a material for forming the hydrophilic layer matrix, a metal oxide is preferable. The metal oxide preferably contains metal oxide fine particles. Examples thereof include colloidal silica, alumina sol, titania sol, and other metal oxide sols. The form of the metal oxide fine particles may be spherical, needle-like, feather-like, or any other form. The average particle diameter is preferably 3 to 100 nm, and several kinds of metal oxide fine particles having different average particle diameters can be used in combination. Further, the surface of the particles may be subjected to a surface treatment. The metal oxide fine particles can be used as a binder by utilizing the film forming property. The decrease in hydrophilicity is less than when an organic binder is used, and it is suitable for use in a hydrophilic layer.
[0081]
Among the above, colloidal silica can be preferably used in the present invention. Colloidal silica has the advantage of high film-forming properties even under relatively low temperature drying conditions, and can provide good strength.
[0082]
The colloidal silica preferably includes necklace-like colloidal silica, which will be described later, and fine particle colloidal silica having an average particle size of 20 nm or less, and the colloidal silica preferably exhibits alkalinity as a colloidal solution.
[0083]
Necklace-shaped colloidal silica is a generic term for an aqueous dispersion of spherical silica whose primary particle diameter is on the order of nm, and spherical colloidal silica whose primary particle diameter is 10 to 50 nm is bonded to a length of 50 to 400 nm. Means “pearl necklace-shaped” colloidal silica. The pearl necklace shape (that is, the pearl necklace shape) means that the image in a state in which the silica particles of colloidal silica are connected and connected has a shape like a pearl necklace. The bond between the silica particles constituting the necklace-shaped colloidal silica is presumed to be —Si—O—Si— in which —SiOH groups present on the surface of the silica particles are dehydrated. Specific examples of the colloidal silica in the form of necklace include “Snowtex-PS” series manufactured by Nissan Chemical Industries, Ltd.
[0084]
Product names include “Snowtex-PS-S (average particle size in the connected state is about 110 nm)”, “Snowtex-PS-M (average particle size in the connected state is about 120 nm)” and “Snowtex- PS-L (the average particle size in the connected state is about 170 nm) ", and acidic products corresponding to these are" Snowtex-PS-SO "," Snowtex-PS-MO "and “Snowtex-PS-LO”.
[0085]
By adding necklace-like colloidal silica, it becomes possible to maintain the strength while ensuring the porosity of the layer, and it can be preferably used as a porous material for the hydrophilic layer matrix. Among these, when using “Snowtex PS-S”, “Snowtex PS-M” and “Snowtex PS-L” which are alkaline, the strength of the hydrophilic layer is improved and even when the number of printed sheets is large. Generation | occurrence | production of background dirt is suppressed and it is especially preferable.
[0086]
In addition, it is known that the colloidal silica has a stronger binding force as the particle diameter is smaller, and it is preferable to use colloidal silica having an average particle diameter of 20 nm or less in the present invention, more preferably 3 to 15 nm. preferable. In addition, as described above, alkaline colloidal silica is particularly preferably used because it is highly effective in suppressing the occurrence of soiling.
[0087]
Examples of alkaline colloidal silica having an average particle diameter within this range include “Snowtex-20 (particle diameter 10-20 nm)”, “Snowtex-30 (particle diameter 10-20 nm)”, “Snow” manufactured by Nissan Chemical Co., Ltd. "Tex-40 (particle size 10-20 nm)", "Snowtex-N (particle size 10-20 nm)", "Snowtex-S (particle size 8-11 nm)", "Snowtex-XS (particle size 4- 6 nm) ".
[0088]
Colloidal silica having an average particle size of 20 nm or less is particularly preferable because it can be further improved in strength while maintaining the porous property of the layer when used in combination with the aforementioned necklace-shaped colloidal silica.
[0089]
The ratio of colloidal silica / necklace-like colloidal silica having an average particle diameter of 20 nm or less is preferably 95/5 to 5/95, more preferably 70/30 to 20/80, and still more preferably 60/40 to 30/70.
[0090]
As a porous material for the hydrophilic layer matrix, porous metal oxide particles having a particle size of less than 1 μm can be contained. As the porous metal oxide particles, porous silica particles, porous aluminosilicate particles or zeolite particles described later can be preferably used.
[0091]
The porous silica particles are generally produced by a wet method or a dry method. In the wet method, it can be obtained by drying and pulverizing a gel obtained by neutralizing an aqueous silicate solution, or by pulverizing a precipitate deposited after neutralization. In the dry method, silicon tetrachloride is burned together with hydrogen and oxygen to obtain silica. These particles can be controlled in porosity and particle size by adjusting the production conditions. As the porous silica particles, those obtained from a wet gel are particularly preferable.
[0092]
The porous aluminosilicate particles are produced, for example, by the method described in JP-A-10-71764. That is, it is an amorphous composite particle synthesized by hydrolysis using aluminum alkoxide and silicon alkoxide as main components. The ratio of alumina to silica in the particles can be synthesized in the range of 1: 4 to 4: 1. Moreover, what was manufactured as composite particle | grains of 3 or more components by adding the alkoxide of another metal at the time of manufacture can be used for this invention. These composite particles can also control the porosity and particle size by adjusting the production conditions.
[0093]
The porosity of the particles is preferably 0.5 ml / g or more in terms of pore volume, more preferably 0.8 ml / g or more, and 1.0 to 2.5 ml / g or less. Further preferred. The pore volume is closely related to the water retention of the coating film. The larger the pore volume, the better the water retention, the less likely to get stained during printing, and the greater the water volume latitude, but greater than 2.5 ml / g. When it becomes, since particle | grains will become very brittle, durability of a coating film will fall. When the pore volume is less than 0.5 ml / g, the printing performance may be slightly insufficient.
[0094]
Zeolite particles are crystalline aluminosilicates and are porous bodies having regular three-dimensional network voids with pore diameters of 0.3 to 1 nm. The general formula combining natural and synthetic zeolite is expressed as follows:
[0095]
(M₁, M₂1/2)_m(Al_mSi_nO_{2 (m + n)}XH₂O
Where M₁, M₂Is an exchangeable cation, and M₁Li⁺, Na⁺, K⁺, Tl⁺, Me_FourN⁺(TMA), Et_FourN⁺(TEA), Pr_FourN⁺(TPA), C₇H₁₅N₂ ⁺, C₈H₁₆N⁺Etc., M₂Is Ca²⁺, Mg²⁺, Ba²⁺, Sr²⁺, C₈H₁₈N₂ ²⁺Etc. Further, n ≧ m, and the value of m / n, that is, the Al / Si ratio is 1 or less. The higher the Al / Si ratio, the greater the amount of exchangeable cations, and thus the higher the polarity and therefore the higher the hydrophilicity. A preferable Al / Si ratio is 0.4 to 1.0, and more preferably 0.8 to 1.0. x represents an integer.
[0096]
As the zeolite particles used in the present invention, a synthetic zeolite having a stable Al / Si ratio and a relatively sharp particle size distribution is preferable. For example, zeolite A: Na₁₂(Al₁₂Si₁₂O₄₈27H₂O: Al / Si ratio 1.0, zeolite X: Na₈₆(Al₈₆Si₁₀₆O₃₈₄) ・ 264H₂O: Al / Si ratio 0.811, zeolite Y: Na₅₆(Al₅₆Si₁₃₆O₃₈₄) ・ 250H₂O; Al / Si ratio 0.412 and the like.
[0097]
By containing highly hydrophilic porous particles having an Al / Si ratio of 0.4 to 1.0, the hydrophilicity of the hydrophilic layer itself is greatly improved, it is difficult to get dirty during printing, and the water latitude is widened. Also, fingerprint marks are greatly improved. When the Al / Si ratio is less than 0.4, the hydrophilicity is insufficient, and the effect of improving the performance becomes small.
[0098]
Further, the hydrophilic layer matrix of the printing plate material of the present invention can contain layered clay mineral particles. Examples of the layered clay mineral particles include kaolinite, halloysite, talc, smectite (montmorillonite, beidellite, hectorite, sabonite, etc.), vermiculite, mica (mica), chlorite, and hydrotalcite, layered polysilicate. (Kanemite, macatite, ialite, magadiaite, Kenyaite, etc.). Among them, it is considered that the higher the charge density of the unit layer (unit layer), the higher the polarity and the higher the hydrophilicity. The charge density is preferably 0.25 or more, more preferably 0.6 or more. Examples of the layered clay mineral having such a charge density include smectite (charge density 0.25 to 0.6; negative charge), vermiculite (charge density 0.6 to 0.9; negative charge) and the like. In particular, synthetic fluoromica is preferable because it can be obtained with stable quality such as particle size. Among the synthetic fluorine mica, those that are swellable are preferable, and those that are free swell are more preferable.
[0099]
In addition, the layered clay mineral intercalation compound (pillar crystal, etc.), the one subjected to ion exchange treatment, the one subjected to surface treatment (silane coupling treatment, compounding treatment with organic binder, etc.) Can be used.
[0100]
As the size of the plate-like layered clay mineral particles, the average particle size (maximum particle length) is less than 1 μm in the state of being contained in the layer (including the case where the swelling step and the dispersion peeling step are performed), The average aspect ratio is preferably 50 or more. When the particle size is in the above range, the continuity and flexibility in the planar direction, which are the characteristics of the thin layered particles, are imparted to the coating film, and it is difficult for cracks to occur, and a tough coating film can be obtained in a dry state. Moreover, in the coating liquid containing many particulate matters, sedimentation of particulate matter can be suppressed by the thickening effect of the layered clay mineral. When the particle diameter is larger than the above range, the coating film may be non-uniform, and the strength may be locally reduced. Further, when the aspect ratio is not more than the above range, the number of tabular grains with respect to the addition amount is reduced, the viscosity is insufficient, and the effect of suppressing the sedimentation of the particulate matter is reduced.
[0101]
The content of the layered clay mineral particles is preferably 0.1 to 30% by mass, and more preferably 1 to 10% by mass of the entire layer. In particular, swellable synthetic fluorinated mica and smectite are preferable because they can be effective even when added in a small amount. The layered clay mineral particles may be added to the coating solution in powder form, but in order to obtain a good degree of dispersion even with a simple preparation method (no need for a dispersion step such as media dispersion), the layered clay mineral particles are added. It is preferable to prepare the gel swollen alone in water and then add it to the coating solution.
[0102]
A silicate aqueous solution can also be used as another additive material in the hydrophilic layer matrix. Alkali metal silicates such as silicate Na, silicate K, and silicate Li are preferred, and their SiO₂/ M₂The O ratio is preferably selected so that the pH of the entire coating solution when the silicate is added does not exceed 13 in order to prevent dissolution of the inorganic particles.
[0103]
Further, an inorganic polymer or an organic-inorganic hybrid polymer using a metal alkoxide by a so-called sol-gel method can also be used. The formation of an inorganic polymer or an organic-inorganic hybrid polymer by the sol-gel method is described in, for example, “Application of the sol-gel method” (Sakuo Sakuo / Agne Jofusha) or in this book Known methods described in the cited documents can be used.
[0104]
Moreover, you may contain water-soluble resin or water-dispersible resin. Examples of water-soluble resins and water-dispersible resins include polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, styrene-butadiene copolymers, and conjugated diene systems of methyl methacrylate-butadiene copolymers. Resins such as polymer latex, acrylic polymer latex, vinyl polymer latex, polyacrylamide, and polyvinyl pyrrolidone can be mentioned. In the present invention, it is preferable to use a polysaccharide as the water-soluble resin.
[0105]
As polysaccharides, starches, celluloses, polyuronic acids, pullulans and the like can be used, but cellulose derivatives such as methyl cellulose salts, carboxymethyl cellulose salts, hydroxyethyl cellulose salts are particularly preferable, and sodium salts and ammonium salts of carboxymethyl cellulose are preferable. More preferred.
[0106]
This is because the effect of forming the surface shape of the hydrophilic layer in a preferable state can be obtained by including the polysaccharide in the hydrophilic layer.
[0107]
The surface of the hydrophilic layer preferably has a concavo-convex structure with a pitch of 0.1 to 20 μm like the aluminum grain of the PS plate, and this concavo-convex improves water retention and image area retention.
[0108]
Such a concavo-convex structure can be formed by adding an appropriate amount of a filler having an appropriate particle size to the hydrophilic layer matrix. However, the above-mentioned alkaline colloidal silica and the above-mentioned water-soluble solution are added to the hydrophilic layer coating solution. In order to obtain a structure having better printability, it is preferable to include a hydrophilic polysaccharide and form a phase separation when the hydrophilic layer is applied and dried.
[0109]
The shape of the concavo-convex structure (such as pitch and surface roughness) is the type and amount of alkaline colloidal silica, the type and amount of water-soluble polysaccharides, the type and amount of other additives, the solid content concentration of the coating solution, and the wet film. The thickness and drying conditions can be appropriately controlled.
[0110]
The water-soluble resin added to the hydrophilic matrix in the present invention is preferably present in a state where at least a part thereof is water-soluble and can be eluted in water. This is because even if it is a water-soluble material, when it is cross-linked by a cross-linking agent or the like and becomes insoluble in water, its hydrophilicity is lowered and printability may be deteriorated.
[0111]
Further, the resin may further contain a cationic resin. Examples of the cationic resin include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine or derivatives thereof, and acrylic having a tertiary amino group or a quaternary ammonium group. Examples thereof include resins and diacrylamine. The cationic resin may be added in the form of fine particles. Examples thereof include a cationic microgel described in JP-A-6-161101.
[0112]
Further, the hydrophilic layer coating solution may contain a water-soluble surfactant for the purpose of improving the coating property. A surfactant such as Si-based, F-based, or acetylene glycol-based surfactant can be used, but it is particularly preferable to use a surfactant containing Si element because there is no fear of causing printing stains. The content of the surfactant is preferably 0.01 to 3% by mass, more preferably 0.03 to 1% by mass, based on the entire hydrophilic layer (solid content as the coating solution).
[0113]
In addition, the hydrophilic layer can contain a phosphate. In the present invention, since the hydrophilic layer coating solution is preferably alkaline, the phosphate is preferably added as trisodium phosphate or disodium hydrogen phosphate. By adding phosphate, the effect of improving the mesh opening at the time of printing can be obtained. The addition amount of phosphate is preferably 0.1 to 5% by mass, and more preferably 0.5 to 2% by mass as an effective amount excluding hydrate.
[0114]
Furthermore, the fatty acid amide fine particles described above can be contained as a lubricant, and the scratch resistance of the hydrophilic layer can be improved.
[0115]
Moreover, a photothermal conversion raw material can also be contained. As the photothermal conversion material, in the case of a particulate material, the particle size is preferably less than 1 μm.
[0116]
In order to appropriately control the surface shape, the hydrophilic layer can contain particles coated with an inorganic or inorganic material having a particle size of 1 μm or more. As the inorganic particles, known metal oxide particles such as silica, alumina, titania and zirconia can be used. However, in order to suppress sedimentation in the coating solution, it is preferable to use porous metal oxide particles.
[0117]
As the porous metal oxide particles, the aforementioned porous silica particles and porous aluminosilicate particles can be preferably used.
[0118]
Examples of the particles coated with an inorganic material include particles obtained by coating an organic particle core material such as PMMA or polystyrene with inorganic particles having a smaller particle diameter than the core material particle. The particle size of the inorganic particles is preferably about 1/10 to 1/100 of the core particles. As the inorganic particles, known metal oxide particles such as silica, alumina, titania, zirconia, etc. can be used. As the coating method, various known methods can be used, but the core material particles and the coating material particles are collided at high speed in the air such as a hybridizer to cause the coating material particles to bite into the surface of the core material particles. It is preferable to use a dry coating method of fixing and coating.
[0119]
Moreover, the particle | grains which carried out the metal plating of the core material of an organic particle can also be used. Examples of such particles include “Micropearl AU” manufactured by Sekisui Chemical Co., Ltd., in which resin particles are plated with gold.
[0120]
The particle size is 1 μm or more, preferably 1 to 10 μm, more preferably 1.5 to 8 μm, still more preferably 2 to 6 μm. When the particle diameter exceeds 10 μm, there is a concern that the resolution of image formation is reduced and the blanket stain is deteriorated. The amount of particles having a particle size of 1 μm or more is appropriately adjusted so as to satisfy the surface morphology parameters of the present invention, but is preferably 1 to 50% by mass of the entire hydrophilic layer, and 5 to 40% by mass. % Is more preferable.
[0121]
The hydrophilic layer as a whole preferably has a low content ratio of materials containing carbon such as organic resin and carbon black in order to improve hydrophilicity, and the total of these materials is preferably less than 9% by mass. More preferably, it is less than 5 mass%.
[0122]
In the second embodiment, the layer B is lipophilic, and the surface of the layer formed adjacent to the substrate surface or the substrate side of the layer A is hydrophilic.
[0123]
As the base material in this embodiment, the above-mentioned roughened and anodized aluminum base material, a base material in which the above-mentioned hydrophilic layer is formed on a plastic film base material, and the like can be preferably used.
[0124]
Any material may be used for the layer B as the oleophilic layer as long as it has ink fillability. For example, a known thermosetting resin or thermoplastic resin can be used.
[0125]
Specific examples of the thermosetting resin include urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin, urethane resin and the like. Specific examples of thermoplastic resins include ethylene polymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, vinyl chloride resins, cellulose resins, rosin resins, polyvinyl resins. Resins such as alcohol resins, polyvinyl acetal resins, ionomer resins, petroleum resins; elastomers such as natural rubber, styrene butadiene rubber, isoprene rubber, chloroprene rubber, diene copolymer; ester gum, rosin maleic resin, rosin Examples thereof include rosin derivatives such as phenol resin and hydrogenated rosin; and polymer compounds such as phenol resin, terpene resin, cyclopentadiene resin, and aromatic hydrocarbon resin.
[0126]
These materials can be dissolved in a solvent and applied to form a layer B. In the present invention, the layer B is preferably formed by coating from a water-based paint, and an emulsion of these resins is formed into a film. A formed layer is preferable. Particularly preferred materials include acrylic resin emulsions and urethane resin emulsions.
[0127]
The layer B preferably has high strength and has physical properties that are easily removed by on-press development. This means that it is preferable that the layer itself has the property of breaking before it is distracted too much. For this reason, it can bridge | crosslink using a crosslinking agent, or can combine with an inorganic raw material and can provide a hard and brittle property.
[0128]
In both cases of the first and second aspects, the layer B can also contain the above-described photothermal conversion material. Since the unexposed portion of the layer B is developed on-press, it is preferable to use a light-heat conversion material that is less colored with visible light, and it is particularly preferable to use a light-color light-to-heat conversion dye.
[0129]
When layer B contains a photothermal conversion pigment as the photothermal conversion material, the content is 1 to 30% by mass of the entire layer B, and more preferably 2 to 20% by mass. When layer B contains a photothermal conversion dye as a photothermal conversion material, the content is 0.1 to 20% by mass of the entire layer B, and more preferably 0.5 to 10% by mass. A photothermal conversion pigment and a photothermal conversion dye can also be used in combination.
[0130]
However, it is preferable that the infrared absorption amount by the layer B is set to be smaller than the total infrared absorption amount of the layer containing the photothermal conversion material present on the substrate side than the layer B. This is because the strength is improved only on the surface layer side of the layer A, the strength improvement of the base material side portion of the layer A is insufficient, and the exposed portion is also developed on the machine, or the printing durability is lowered. This is to prevent becoming.
[0131]
In the present invention, the printing plate material according to any one of claims 1 to 6 is further exposed to an infrared laser, and then printed on a printing machine using dampening water or ink, or dampening water and ink. In this printing method, the layer B and the layer A in the unexposed area are removed by performing the above.
[0132]
In the printing plate material of the present invention, the surface layer B is a layer that is substantially insoluble in water and does not swell, and the on-press development uses the peeling force in the ink tack by contacting the ink roller. Therefore, the on-press development and printing can be performed even when using a sequence in which the ink supply roller comes in contact with the plate surface of the printing plate material before the water supply roller. It can be performed.
[0133]
At this time, the paper may be fed simultaneously with the ink supply roller contact, the cylinder may be inserted, and printing may be started, or the plate cylinder may be rotated 1 to several tens times while the ink supply roller is kept in contact, and the paper is fed. You may insert the cylinder and start printing. The water supply roller is brought into contact with the plate surface at any timing during which the plate cylinder rotates several tens of times after the ink supply roller contacts. At this time, the initial water supply amount may be increased with respect to the water supply amount in the steady printing state.
[0134]
For removing the layer on the printing press as described above, US Pat. Nos. 6,095,048, 6,140,392, JP-A 2000-7971, and 2001-26735 are used. The single fluid ink or emulsion ink described in Japanese Patent Publication No. 2002-20669 can be used without supplying dampening water. The infrared exposure can be performed on a printing machine.
[0135]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
[0136]
Example 1
<Production of base material>
<Base material 1>
An undercoat layer was formed on one side of a 175 μm-thick PET film by the following procedure to obtain a substrate 1.
[0137]
1) First undercoat layer
After the corona discharge treatment was applied to the coated surface of the PET film, a coating solution having the following composition was coated with a wire bar so that the film thickness after drying was 0.4 μm in an atmosphere of 20 ° C. and a relative humidity of 55%. . Thereafter, drying was performed at 140 ° C. for 2 minutes.
[0138]
(First undercoat layer composition)
Acrylic latex particles: n-butyl acrylate / t-butyl acrylate / styrene / hydroxyethyl methacrylate = 28/22/25/25
36.9g
Surfactant (A) 0.36g
Hardener (a) 0.98g
Distilled water was added to make 1000 ml, and a coating solution was obtained.
[0139]
2) Second undercoat layer
After the surface of the film having the first undercoat layer formed thereon is subjected to a corona discharge treatment, a coating solution having the following composition is dried by an air knife method in an atmosphere of 35 ° C. and a relative humidity of 22% so that the film thickness after drying is 0. It was applied so as to be 1 μm. Thereafter, drying was performed at 140 ° C. for 2 minutes.
[0140]
(Second undercoat layer composition)
9.6 g of gelatin
Surfactant (A) 0.4g
Hardener (b) 0.1g
Distilled water was added to make 1000 ml, and a coating solution was obtained.
[0141]
[Chemical 1]

[0142]
<Substrate 2>
A PET film (HS74, manufactured by Teijin Limited) having a thickness of 175 μm on which an undercoat layer for an aqueous coating solution was formed was used.
[0143]
<Base material 3>
An aluminum plate (material 1050, tempered H16) having a thickness of 0.24 mm was immersed in a 1% by mass sodium hydroxide aqueous solution at 50 ° C., and the dissolution amount was 2 g / m.²The solution was subjected to dissolution treatment, washed with water, then immersed in a 0.1% by mass hydrochloric acid aqueous solution at 25 ° C. for 30 seconds, neutralized, and then washed with water.
[0144]
Subsequently, the peak current density is 50 A / dm using an alternating current of a sine wave with an electrolytic solution containing hydrochloric acid 10 g / L and aluminum 0.5 g / L.²The electrolytic surface roughening treatment was performed under the following conditions. The distance between the electrode and the sample surface at this time was 10 mm. The electrolytic surface roughening treatment is performed in 12 steps, and the amount of electricity for treatment (at the time of anode) is 30 C / dm.²And 360 C / dm in total²The amount of electricity to be treated (at the time of anode). In addition, a rest period of 5 seconds was provided between each surface roughening treatment.
[0145]
After electrolytic roughening, the amount of dissolution including the smut of the roughened surface is 2 g / m by dipping in a 1% by weight aqueous sodium hydroxide solution maintained at 50 ° C.²Etching was performed, and the sample was washed with water, then immersed in a 10% aqueous sulfuric acid solution maintained at 25 ° C. for 10 seconds, neutralized, and then washed with water. Next, in a 20% sulfuric acid aqueous solution, the amount of electricity is 150 C / dm2 at a constant voltage of 20 V.²Then, anodization was performed, and further washing with water was performed.
[0146]
Next, after squeezing the surface water after washing with water, it was immersed in a 1% by mass of No. 3 sodium silicate aqueous solution maintained at 70 ° C. for 30 seconds, washed with water, dried at 80 ° C. for 5 minutes, and then the substrate 3 Got. Ra of the substrate 3 was 400 nm (measured at 40 times using RST Plus manufactured by WYKO).
[0147]
<< Preparation of coating solution for layer A >>
The raw materials having the compositions shown in Tables 1 and 2 were sufficiently stirred and mixed, and then filtered to prepare coating solutions of layers A-1 to A-5 (comparing layer A-3).
[0148]
[Table 1]

[0149]
[Table 2]

[0150]
<< Preparation of coating liquid for layer B that is hydrophilic >>
The raw materials having the compositions shown in Tables 3 and 4 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare hydrophilic coating layers B-1 to B-4 (comparing layer B-3).
[0151]
[Table 3]

[0152]
[Table 4]

[0153]
[Preparation of printing plate materials]
In the combination of the base material and the coating solution shown in Table 5, each coating solution of Layer A and Layer B is applied with a wire bar so as to have the dry weight shown in the table, and the present invention and the comparative printing plate The material was made. Table 5 also indicates whether the produced printing plate material is of a positive type (exposed portion becomes a non-image portion) or negative type (exposed portion becomes an image portion). Layer A and layer B were dried at 55 ° C. for 3 minutes, and after layer B was formed by coating, aging was performed at 40 ° C. for 72 hours.
[0154]
<Image formation>
Image formation was performed by infrared laser exposure. For the exposure, a laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm is used. The laser beam is focused on the surface of the printing plate material, and the exposure energy is 300 mJ / cm.²As an example, an image was formed with 175 lines at 2400 dpi (dpi represents the number of dots per inch, that is, 2.54 cm). As an image for evaluation, an unexposed portion, a solid exposure image, and a 1 to 99% halftone dot exposure image were used.
[0155]
<Printing method>
<Printing method 1>
Printing machine: A printing plate material is attached to a plate cylinder of DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd., coated paper, dampening water (ASTROMARK 3 (manufactured by Nikken Chemical Laboratories)), 2% by mass, ink (Toyo Ink Co., Ltd.) Printing was carried out using TK High Unity M Red). The sequence for starting printing is the printing sequence of the PS plate (after rotating the plate cylinder, the water supply roll is brought into contact with the plate surface for 3 rotations, and then the ink supply roll is brought into contact with the plate surface. Was supplied and the cylinder entered and printing started), and no special on-press development operation was performed.
[0156]
<Printing method 2>
As a sequence for starting printing, after the plate cylinder is rotated, the ink supply roll is brought into contact with the plate surface for 3 rotations, and then the water supply roll is brought into contact with the plate surface for 2 rotations so that the paper is supplied to the impression cylinder. Then, printing was performed in the same manner as in printing method 1 except that the sequence that the cylinder entered and printing was started was used.
[0157]
<Printability, background stain>
Until printed matter having a good S / N (no smudge in the non-image area, a well-reproduced halftone image in the image area, and a solid density within an appropriate range) is obtained at the time of printing. The number of printed sheets was evaluated. The results are shown in Table 5. In addition, the symbol in a table | surface has shown the following evaluation result. In addition, the presence / absence of background smudges at the time of printing 100 sheets was also evaluated at the same time. The results are shown in Table 5. These evaluations were performed by printing method 1 and printing method 2.
[0158]
A: Less than 20 sheets
○: 20 or more and less than 50
Δ: 50 or more and less than 100
×: 100 or more
<Scratch dirt resistance>
Before printing, the non-image area of the exposed printing plate material sample is marked with scratches by changing the load using a HEIDON tester. Evaluated whether or not. A 0.3 mmφ sapphire needle was used as the stylus. The results are shown in Table 5. In addition, the symbol in a table | surface has shown the following evaluation result.
[0159]
A: 150 g or more
○: 100 g or more and less than 150 g
Δ: 50 g or more and less than 100 g
X: Less than 50 g
[0160]
[Table 5]

[0161]
  From Table 5,Reference exampleIt can be seen that this printing plate material has good printability, high scratch stain resistance, and no non-image area background stains.
[0162]
Example 2
<< Preparation of Lipophilic Layer B Coating Liquid >>
The raw materials having the compositions shown in Table 6 were sufficiently stirred and mixed, and then filtered to prepare coating solutions for layers B-5 to 8.
[0163]
[Table 6]

[0164]
[Preparation of printing plate materials]
The base material shown in Table 7 and the coating solution were combined, and each layer was applied with a wire bar so as to have the dry weight shown in the table, thereby producing the present invention and a comparative printing plate material. All types of printing plate materials are negative. The drying conditions for each layer were 55 ° C. for 3 minutes, and aging was performed at 40 ° C. for 72 hours when all layers were applied and formed.
[0165]
<Image formation>
Image formation was performed by infrared laser exposure. For the exposure, a laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm is used. The laser beam is focused on the surface of the printing plate material, and the exposure energy is 350 mJ / cm.²Images were formed with 2400 dpi and 175 lines under the conditions described above. As an image for evaluation, a solid exposure image and a 1 to 99% halftone dot exposure image were used.
[0166]
<Printing method>
The same operation as in Example 1 was performed.
[0167]
<Printability, background stain>
The same operation as in Example 1 was performed. The results are shown in Table 7.
[0168]
<Scratch dirt resistance>
The same operation as in Example 1 was performed. The results are shown in Table 7.
[0169]
<Press life>
Printing was performed up to 20,000 sheets, and the number of prints at the time when the 3% halftone dot image was chipped or the solid image portion was blurred was determined. The results are shown in Table 7.
[0170]
[Table 7]

[0171]
As can be seen from Table 7, it can be seen that the printing plate material of the present invention can provide good performance even when an aluminum plate is used as a base material.
[0172]
【The invention's effect】
According to the present invention, a printing plate material having sufficient printability, scratch stain resistance, non-image area background stain and printing durability as a general-purpose thermal processless plate, and a printing method using the printing plate material are provided. It was possible to provide.

Claims (9)

In a printing plate material having a layer A and a layer B in order on a base material and containing a photothermal conversion material in any layer provided on the base material, the layer A is mechanically generated by heat generated by infrared laser exposure. It is a layer that improves the strength, the layer B is an oleophilic layer that is insoluble in water and does not swell, and the surface of the layer formed adjacent to the substrate side or the substrate side of the layer A is hydrophilic. A printing plate material characterized by being. The printing plate material according to claim 1, wherein the layer B is ink depositable . The printing plate material of claim 1 or 2 the layer B and said Rukoto such a thermosetting resin or a thermoplastic resin. The printing plate material according to any one of claims 1 to 3, wherein an amount of the layer B is 0.1 g / m ² or more and 2.0 g / m ² or less.   The printing plate material according to any one of claims 1 to 4, wherein the layer A contains thermoplastic fine particles.   The printing plate material according to any one of claims 1 to 4, wherein the layer A contains a crosslinking agent.   After exposing the printing plate material according to any one of claims 1 to 6 with an infrared laser, a printing operation is performed using a dampening water and / or ink on a printing machine, whereby the layer B in an unexposed area is formed. And a printing method, wherein the layer A is removed.   The printing method according to claim 7, wherein the ink supply roller contacts the surface of the printing plate before the water supply roller in the printing operation.   9. The printing method according to claim 7, wherein the infrared laser exposure is performed on a printing machine.