JP2004160716A - Printing plate material and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing plate material, using a plastic film support, which shows outstanding printability, especially superb performance such as resistance to plate wear, flaw resistance, recovery properties to stain or dimensional stability during printing. <P>SOLUTION: This printing plate material has a plastic support whose average film thickness is within the range of 110 to 500 μm; at least a single imaging function layer containing a water-soluble resin in one side of the support, the thickness distribution of which is not more than 10%; and at least a single hydrophilic layer between the support and the imaging function layer. <P>COPYRIGHT: (C)2004,JPO

Description

【０１９１】
【化１】

【０１９２】

《プラズマ処理条件》
バッチ式の大気圧プラズマ処理装置（イーシー化学（株）製、ＡＰ−Ｉ−Ｈ−３４０）を用いて、高周波出力が４．５ｋＷ、周波数が５ｋＨｚ、処理時間が５秒及びガス条件としてアルゴン、窒素及び水素の体積比をそれぞれ９０％及び５％で、プラズマ処理を行った。
【０１９３】
１．２５ｍ幅にスリットした後の支持体に対し、張力０．００８ｋｇ／ｍｍ^２で１８０℃、３０秒間、低張力熱処理を実施した。
【０１９４】
《印刷版材料１０１〜１０５の作製》
親水性層を塗設する直前に、下引き済み支持体に対し、１３０℃で３０秒間熱処理を加えて乾燥させ、防湿シートでカバーをして空気中の湿度が入らないようにした。支持体試料の一部をサンプリングして水分率測定をしたところ、ＰＥＴ１は１．２％、ＰＥＴ２は０．２％、ＰＥＮ３は０．２％であった。カバーをしたものについてはシートを除去後、すぐに塗布を行った。
【０１９５】
表１に示す親水性層１用塗布液（調製方法は下記に示す）、表２に示す親水性層２用塗布液（調製方法は下記に示す）、および表３に示す画像形成機能層塗布液１と画像形成機能層塗布液２を用いて各下引き済み支持体の各々のＡ面上にワイヤーバーを用いて塗布した。
【０１９６】
試料１０１は、表４に示す下引き済み支持体上に画像形成機能層塗布液１を、ワイヤーバーを用いて乾燥付量が０．６ｇ／ｍ^２になるように塗布して５０℃で３分間乾燥したのちに、親水性層１、親水性層２の順番でワーヤーバーを用いてそれぞれ、乾燥付き量が２．７ｇ／ｍ^２、０．７ｇ／ｍ^２になるように塗布し、１２０℃で３分間乾燥した。
【０１９７】
試料１０２〜１０５は、表４に示す下引き済み支持体上に親水性層１、親水性層２の順番でワーヤーバーを用いてそれぞれ乾燥付き量が、２．７ｇ／ｍ^２、０．７ｇ／ｍ^２になるように塗布し、１２０℃で３分間乾燥したのちに６０℃で２４時間の加熱処理を施した。その後、表３に示す画像形成機能層塗布液を、ワイヤーバーを用いて乾燥付量が０．６ｇ／ｍ^２になるように塗布して５０℃で３分間乾燥したのちに、５０℃で７２時間のシーズニング処理を施した。
【０１９８】
〈親水性層１用塗布液の調製〉
表１に記載の各素材を、ホモジナイザを用いて十分に攪拌混合した後、表１に記載の組成で混合、濾過して親水性層１用塗布液を調製した。
【０１９９】
なお、各素材の詳細は、以下の通りであり、表中の数値は質量部を表す。
【０２００】
【表１】

【０２０１】
〈親水性層２用塗布液の調製〉
表２に記載の各素材を、ホモジナイザを用いて十分に攪拌混合した後、表２に記載の組成で混合、濾過して親水性層２用塗布液を調製した。
【０２０２】
【表２】

【０２０３】
〈画像形成機能層塗布液の調製〉
【０２０４】
【表３】

【０２０５】
《印刷版材料１０１〜１０５の評価》
（ａ）赤外線レーザ方式による画像形成
上記で作成した印刷版材料１０１〜１０５の試料を、保存性の代用条件として５０℃、８０％ＲＨのサーモ条件で３日間保管した。その試料を露光ドラムに巻付け固定した。露光には、波長８３０ｎｍ、スポット径約１８μｍのレーザビームを用い、露光エネルギを３００ｍＪ／ｃｍ^２とした条件で、２４００ｄｐｉ（ｄｐｉとは、２．５４ｃｍ当たりのドット数を表す。）、１７５線で画像を形成し、印刷版試料１０１〜１０５を各々作製した。
【０２０６】
（ｂ）上記で画像形成した印刷版試料１０１〜１０５について、下記の印刷方法により、印刷版としての諸特性を評価した。
【０２０７】
《印刷方法》
印刷装置として、三菱重工業社製のＤＡＩＹＡ１Ｆ−１を用いて、コート紙と、湿し水としてアストロマーク３（日研化学研究所製）の２質量％溶液、インクとして、東洋インク社製のトーヨーキングハイエコー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で行い、特別な機上現像操作は行わなかった。印刷後に版面を観察したところ、本発明に係る材料の非画像部は除去されていた。
【０２０８】
《インク着肉性の評価》
１０００枚印刷後に、インクの供給を止めて水のみ５分間供給した。その後インクの供給を再開しインクを着肉させて何枚目に正常なインク濃度を有する印刷物が得られるかを評価した。枚数が少ないほどインク着肉性が優れている。
【０２０９】
《スクラッチ汚れ耐性評価》
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。なお、表中の記号は下記の評価結果を示している。
【０２１０】
◎：１５０ｇ以上
○：１００ｇ以上１５０ｇ未満
△：５０ｇ以上１００ｇ未満
×：５０ｇ未満
《寸法安定性の評価》
印刷前に版面に５０μｍ幅のキズを２カ所５０ｃｍ離してつけた。１００枚印刷後の印刷紙面と３０００枚印刷後の印刷紙面で２カ所のキズの距離がどのくらい変化したか測定した。寸法変化（μｍ）が少ないほど優れている。
【０２１１】
《耐刷性の評価》
３％網点画像の点が半分以上欠落する印刷枚数を求めた（印刷は５万枚まで行った）。印刷枚数の多いほど優れている。
【０２１２】
以上により得られた結果を表４に示す。
【０２１３】
【表４】

【０２１４】
表４から、比較の試料と比べて、本発明の印刷版試料は、インク着肉性、スクラッチ汚れ耐性、寸法性が良好であり、且つ、耐刷性にも優れていることが明らかである。
【０２１５】
実施例２
《印刷版材料２０１の作製》
実施例１で作製した印刷版材料１０４と同様にして画像形成機能層を塗布したのち、さらに画像形成機能層の上に下記オーバーコート層をワイヤーバーを用いて乾燥付量が０．４ｇ／ｍ^２となるように塗布し、５０℃で３分間乾燥した。そして更に、画像形成機能層の反対側に下記バック層をワイヤーバーを用いて、乾燥付き量が１．５ｇ／ｍ^２になるよう塗布し、５０℃で２０分間乾燥して、印刷版材料２０１を作製した。さらに５０℃で２４時間のシーズニング処理を施し、その後２３℃相対湿度２０％で２４時間調湿した。
【０２１６】

またバック層の表面の表面粗さを測定したところ、Ｒａ値で０．９μｍであった。
【０２１７】
実施例１と同様にして評価を行った。なお実施例２での耐刷性の評価は、ベタ部にかすれが出る印刷枚数を求めた（印刷は５万枚まで行った）。
【０２１８】
以上により得られた結果を表５に示す。
【０２１９】
【表５】

【０２２０】
表５から、オーバーコート層を設けた本発明の印刷版材料２０１は、インク着肉性、スクラッチ汚れ耐性が良好であり、寸法変化、かつ耐刷性に優れている（ベタ部にかすれがでにくい）ことが明らかである。
【０２２１】
実施例３
実施例１における１０４の印刷版を同様に露光し、露光後の現像を、下記の各タイミングで現像インクを用いて行い、画像形成の状態をルーペを用いて評価した。結果を表６に示す。このように、露光終了後になんらかの乾燥過程を設けることで、画像強度が安定することがわかる。
【０２２２】
【表６】

【０２２３】
【発明の効果】
ＣＴＰに用いられる簡便なプロセスレス印刷版において、耐刷性や汚し回復性、傷の耐性や印刷時の寸法安定性等の印刷性能が本発明の技術により改良できた。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printing plate material using a plastic film support, capable of forming an image by heat, having excellent printing durability, and having high dimensional stability, and a printing method using the printing plate material.
[0002]
[Prior art]
In recent years, with the digitization of print data, CTPs that are inexpensive, easy to handle, and have the same printability as PS plates have been demanded. In particular, in recent years, expectations for a so-called processless printing plate which does not require a developer treatment with a special chemical have been increasing.
[0003]
As a configuration of the processless printing plate, it is possible to use the same aluminum grain as the PS plate. However, from the viewpoint of the flexibility of the layer configuration and cost reduction, various types of process having a coated hydrophilic layer are considered. Less printing plates have been proposed.
[0004]
One of the most prominent image forming methods for processless printing plates is infrared laser recording. Broadly speaking, there are three types of recording methods: ablation type, thermal fusion image layer on-machine development type, and thermal fusion transfer type, which will be described later. Exists.
[0005]
Infrared laser recording makes it possible to record a high-resolution image in a short time, but has a problem that the price of an exposure system is high.
[0006]
Examples of the ablation type include those described in Patent Documents 1 to 5 below. These are, for example, those having a hydrophilic layer and a lipophilic layer on a support, and laminating any of them as a surface layer. If the surface layer is a hydrophilic layer, an image portion can be formed by exposing the lipophilic layer by exposing the hydrophilic layer to an image and exposing the lipophilic layer by ablating the hydrophilic layer. However, since contamination of the inside of the exposure apparatus due to the scattered matter of the ablated surface layer becomes a problem, a water-soluble protective layer is further provided on the hydrophilic layer to prevent the ablated surface layer from scattering and the protective layer on the printing machine. At the same time, a method of removing the ablated surface layer has been proposed.
[0007]
The heat-fused image layer is an on-machine development type in which an image forming layer containing thermoplastic fine particles is used on a support. There is known a so-called processless printing plate technology in which printing can be performed by applying an ink and a fountain solution on a printing press to remove unnecessary portions without performing chemical treatment of a liquid or the like (Patent Documents 6 to 6). 7)).
[0008]
In addition, as a hot-melt transfer type, for example, using a hot-transfer ribbon such as Manroland's DICOweb, a hot-melt material is image-likely applied to a metal sleeve having a reusable hydrophilic surface instead of aluminum grain. After the transfer, there is a method of fixing the image by heating.
[0009]
On the other hand, the printing plate support used to be a metal plate such as aluminum, but recently the printing plate technology using a plastic film support has become known as it is convenient for handling and carrying the printing plate. Became. Techniques described in Patent Documents 8 and 9 are also known as on-press development types.
[0010]
However, the printing plate using the plastic film support as described above has a printability, especially a printing durability, and a non-image portion which is stain-recovery suitable for recovering normally when a non-image portion is stained for some reason. In addition, there has been a problem that the resistance to scratches and the dimensional stability during printing are poor.
[0011]
[Patent Document 1]
JP-T 8-507727 (Claims, Examples)
[0012]
[Patent Document 2]
JP-A-6-186750 (Claims, Examples)
[0013]
[Patent Document 3]
JP-A-6-199064 (Claims, Examples)
[0014]
[Patent Document 4]
JP-A-7-314934 (Claims, Examples)
[0015]
[Patent Document 5]
JP-A-10-244773 (Claims, Examples)
[0016]
[Patent Document 6]
Japanese Patent Application Laid-Open No. 9-12387 (Claims, Examples)
[0017]
[Patent Document 7]
JP-A-9-123388 (Claims, Examples)
[0018]
[Patent Document 8]
JP-A-2002-79772 (Claims, Examples)
[0019]
[Patent Document 9]
JP-A-2002-79773 (Claims, Examples)
[0020]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a printing plate material using a plastic film support having excellent printability, particularly performance such as printing durability and soil recovery, and scratch resistance and dimensional stability during printing. It is in.
[0021]
[Means for Solving the Problems]
The object of the present invention is achieved by the means under the above object.
[0022]
1. Image formation of at least one layer containing a water-soluble resin on one surface of a plastic film support having an average thickness of the support in the range of 110 μm to 500 μm and a thickness distribution of the support of 10% or less. A printing plate material comprising a functional layer and at least one hydrophilic layer between the support and the image forming functional layer.
[0023]
2. 2. The printing plate material as described in 1 above, wherein at least one of the hydrophilic layers has a porous structure.
[0024]
3. 3. The printing plate material as described in 1 or 2, wherein the image forming functional layer is a layer capable of forming an image by heat, and one of the layers on the support contains a light-to-heat conversion material.
[0025]
4. 4. The printing plate material according to any one of the above items 1 to 3, wherein at least a part of the water-soluble resin is cross-linked with a cross-linking agent capable of thermally cross-linking.
[0026]
5. The printing plate material as described in any one of the above items 1 to 4, wherein the image forming functional layer contains heat fusible fine particles or heat fusible fine particles.
[0027]
6. The printing plate material according to any one of the above items 1 to 5, wherein at least one surface of the support has at least one layer containing a polyvinylidene chloride resin.
[0028]
7. The printing plate material as described in any one of the above items 1 to 6, wherein the moisture content of the support is 0.5% by mass or less.
[0029]
8. 8. The printing plate material as described in any one of 1 to 7, wherein the support has at least one constituent layer on the side opposite to the image forming functional layer.
[0030]
9. A printing method, comprising: after forming an image on the printing plate material according to any one of 1 to 8 above using a thermal head or a thermal laser, removing a non-image portion of the image forming functional layer on a printing press. .
[0031]
10. After forming an image of the printing plate material according to any one of 1 to 8 using a thermal head or a thermal laser, in a printing method for performing printing, after image formation, the printing plate material surface on a printing press. A printing method, comprising a step of drying the surface of a printing plate material until the surface of the printing plate material contacts the water supply roller or the ink supply roller.
[0032]
Hereinafter, the present invention will be described.
《Plastic film support》
The plastic film support according to the printing plate material of the present invention will be described.
[0033]
(Materials constituting the support)
As a constituent material of the plastic film support according to the present invention, a plastic film is preferable, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polycarbonate, polysulfone, polyphenylene oxide, and cellulose esters.
[0034]
The support according to the present invention has an elastic modulus at 120 ° C. (E120) of 100 kg / mm from the viewpoint of imparting the above-described handling suitability to the printing plate material of the present invention.²~ 600kg / mm²And more preferably 120 kg / mm²~ 500kg / mm²It is. Specifically, polyethylene naphthalate (E120 = 410 kg / mm²), Polyethylene terephthalate (E120 = 150 kg / mm)²), Polybutylene phthalate (E120 = 160 kg / mm)²), Polycarbonate (E120 = 170 kg / mm²), Syndiotactic polystyrene (E120 = 220 kg / mm²), Polyetherimide (E120 = 190 kg / mm)²), Polyarylate (E120 = 170 kg / mm)²), Polysulfone (E120 = 180 kg / mm)²), Polyether sulfone (E120 = 170 kg / mm)²) And the like. These may be used alone, or may be used by laminating or mixing. Among them, particularly preferred plastic films include polyethylene naphthalate and polyethylene terephthalate.
[0035]
Here, the elastic modulus is obtained by using a tensile tester to find the slope of the stress with respect to the strain amount in a region where the strain indicated by the marked line of the sample conforming to JIS C2318 and the corresponding stress have a linear relationship. It is a thing. This is a value called a Young's modulus, and in the present invention, the Young's modulus is defined as an elastic modulus.
[0036]
Further, the support according to the present invention, in order for the printing plate material of the present invention to exhibit the effects described in the present invention, from the viewpoint of improving the handling suitability when installing the printing plate material in a printing press, the average film thickness. Is in the range of 110 μm to 500 μm, and the thickness distribution is preferably 10% or less.
[0037]
As described above, the average thickness of the support is preferably in the range of 110 μm to 500 μm, more preferably in the range of 120 μm to 400 μm, and particularly preferably in the range of 125 μm to 300 μm.
[0038]
The thickness distribution (the value obtained by dividing the difference between the maximum value and the minimum value of the thickness by the average thickness and expressed as a percentage) of the support according to the present invention is preferably 10% or less as described above, and more preferably 8% or less. %, Particularly preferably 6% or less.
[0039]
Here, the method of measuring the thickness distribution of the support is as follows. A support cut out into a square having a side of 60 cm is drawn in a grid pattern at intervals of 10 cm in length and width, and the thickness of these 36 points is measured, and the average value and the maximum value are measured. Find the value and minimum value.
[0040]
(Method of manufacturing support)
In order to adjust the average film thickness and the thickness distribution of the support according to the present invention to the above ranges, there is a method of adjusting the film forming conditions appropriately, or adjusting the film with a smooth roller while reheating after film formation. In the present invention, it is preferable to be manufactured by the film forming process described below.
[0041]
As a means for forming a film of the support, a thermoplastic resin is melted at a temperature between melting point (Tm) and Tm + 50 ° C., filtered with a sintering filter or the like, extruded from a T-die, and then glass transition temperature (Tg) −50. An unstretched sheet is formed on a casting drum controlled at a temperature of from C to Tg. At this time, it is preferable to use an electrostatic application method or the like to make the thickness distribution fall within the above range.
[0042]
The unstretched sheet is longitudinally stretched 2 to 4 times between Tg and Tg + 50 ° C. Further, as another method for adjusting the thickness distribution to the above range, it is preferable to perform longitudinal stretching in multiple stages. At this time, it is preferable to adjust the temperature of the second-stage stretching higher than that of the first-stage stretching in the range of 1 ° C to 30 ° C, and more preferably, to adjust the temperature in the range of 2 ° C to 15 ° C.
[0043]
The magnification in the first-stage stretching is preferably 0.25 to 0.7 times, more preferably 0.3 to 0.5 times the magnification in the second-stage stretching. Then, after holding for 5 seconds to 60 seconds, more preferably for 10 seconds to 40 seconds in the temperature range of Tg-30 ° C. to Tg, it is increased 2.5 to 5 times between Tg and Tg + 50 ° C. in the lateral direction. Stretching is preferred.
[0044]
Thereafter, heat fixing is performed at (Tm-50 ° C.) to (Tm-5 ° C.) for 5 seconds to 120 seconds while being held by the chuck. At this time, it is also preferable to reduce the chuck interval by 0% to 10% in the width direction (thermal relaxation). After cooling, a method of attaching a knurling of 10 μm to 100 μm to the end (also referred to as providing a knurling height), winding, and obtaining a multiaxially stretched film is preferable.
[0045]
(Easy adhesion treatment to support, application of undercoat layer)
In the support according to the present invention, in order to improve the adhesiveness with the coating layer, it is preferable to apply an easy adhesion treatment or an undercoating layer to the coating surface. Examples of the easy adhesion treatment include a corona discharge treatment, a flame treatment, a plasma treatment, and an ultraviolet irradiation treatment.
For example, a layer containing gelatin or latex may be provided on a support as an undercoat layer.
Is preferred. Also, JP-A-7-20596
[0031]
Described in
Conductive polymer containing layer and JP-A-7-20596
~
It is preferable to provide a conductive layer such as the metal oxide-containing layer described in the above. The conductive layer may be coated on any side as long as it is on the plastic film support, but is preferably coated on the side opposite to the image forming functional layer with respect to the support. By providing this conductive layer, the chargeability is improved, the adhesion of dust and the like is reduced, and the occurrence of white spot failure during printing is greatly reduced.
[0046]
Further, as the support according to the present invention, a plastic film support is used, and a plastic film and a material such as a metal plate (for example, iron, stainless steel, aluminum, etc.) or paper coated with polyethylene (also referred to as a composite base material). ) Can be used as appropriate. These composite base materials may be bonded before forming a coating layer, may be bonded after forming a coating layer, or may be bonded immediately before being attached to a printing machine.
[0047]
(Fine particles)
Further, it is preferable to add fine particles of 0.01 μm to 10 μm to the above-mentioned support in an amount of 1 ppm to 1000 ppm for improving the handling property.
[0048]
Here, the fine particles may be either an organic substance or an inorganic substance. For example, as inorganic substances, silica described in Swiss Patent No. 330,158, etc., glass powder described in French Patent No. 1,296,995, etc., British Patent No. 1,173,181 Alkaline earth metals or carbonates such as cadmium, zinc, and the like described in publications and the like can be used. Examples of the organic substance include starch described in U.S. Pat. No. 2,322,037, starch derivatives described in Belgian Patent No. 625,451 and British Patent No. 981,198, and the like. No. 44-3643, polyvinyl alcohol described in Swiss Patent No. 330,158, etc., polystyrene or polymethacrylate described in US Pat. No. 3,079,257, polyacrylonitrile described in US Pat. Organic fine particles such as polycarbonate described in Japanese Patent No. 3,022,169 can be used. The shape of the fine particles may be either regular or irregular.
[0049]
(Polyvinylidene chloride resin)
In one embodiment for obtaining the effects described in the present invention, the printing plate material of the present invention is characterized in that the support is a plastic film as described above, and one surface of the support having an image forming functional layer. However, there is an embodiment having at least one layer containing a polyvinylidene chloride resin.
[0050]
As the polyvinylidene chloride resin according to the present invention, it is preferable to use a copolymer, and the amount of the polymerization component of the vinylidene chloride monomer in the repeating units of the copolymer is 70 to 99.9% by mass. Preferably, it is more preferably 85 to 99% by mass, and particularly preferably 90 to 99% by mass.
[0051]
The copolymerization components other than the vinylidene chloride monomer in the copolymer include methacrylic acid, acrylic acid, itaconic acid, citraconic acid and esters thereof, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, Glycidyl methacrylate, 2-hydroxyethyl methacrylate, vinyl acetate, acrylamide, styrene and the like can be mentioned.
[0052]
The weight average molecular weight of these copolymers is preferably in the range of 5,000 to 100,000, more preferably 8,000 to 80,000, and particularly preferably 10,000 to 45,000. Here, the weight average molecular weight can be measured by a commercially available GPC (gel permeation chromatography) device.
[0053]
The arrangement of the monomer units of these copolymers is not limited, and may be any of random, block, and the like.
[0054]
When the polyvinylidene chloride resin is an aqueous dispersion, it may be a latex of polymer particles having a uniform structure or a latex of so-called core-shell structure polymer particles having different compositions in a core portion and a shell portion. Specific examples of the vinylidene chloride copolymer include the following. However, the numerical value indicating the copolymerization ratio is a mass ratio, and Mw indicates a weight average molecular weight.
[0055]
(A) Latex of vinylidene chloride: methyl acrylate: acrylic acid (90: 9: 1) (Mw = 42000)
(B) Latex of vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (87: 4: 4: 4: 1) (Mw = 40000)
(C) Latex of vinylidene chloride: methyl methacrylate: glycidyl methacrylate: methacrylic acid (90: 6: 2: 2) (Mw = 38000)
(D) Latex of vinylidene chloride: ethyl methacrylate: 2-hydroxyethyl methacrylate: acrylic acid (90: 8: 1.5: 0.5) (Mw = 44000)
(E) Core-shell type latex (core 90% by mass, shell 10% by mass)
Core: vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (93: 3: 3: 0.9: 0.1)
Shell part: vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (88: 3: 3: 3: 3) (Mw = 38000)
(F) Core-shell type latex (core 70% by mass, shell 30% by mass)
Core: vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (92.5: 3: 3: 1: 0.5)
Shell part: vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (90: 3: 3: 1: 3) (Mw = 20,000)
(Polyvinylidene chloride containing layer)
The polyvinylidene chloride resin according to the present invention may be any of an undercoat layer, a hydrophilic layer described later, an image forming function layer, and other layers as long as the image forming function layer is coated on the support. , But is preferably contained in an undercoat layer. The undercoat layer may be a single layer or a plurality of layers. The thickness of these layers is preferably provided on at least one side of the support with a thickness in the range of 0.5 to 10 μm, and more preferably, on both sides of the support, layers having a thickness of 0.8 to 5 μm each. It is particularly preferable that both sides have a thickness of 1.0 to 3 μm.
[0056]
(Moisture content of support)
In the present invention, the moisture content of the support is D 'represented by the following formula.
D ′ (% by mass) = (w ′ / W ′) × 100
In the formula, W 'is the mass of the support which is in a moisture-conditioning equilibrium under an atmosphere of 25 ° C. and 60% RH, w' is the moisture content of the support which is in a humidity-conditioning equilibrium under an atmosphere of 25 ° C. and 60% RH Represents
[0057]
The moisture content of the support is preferably 0.5% by mass or less, more preferably 0.01 to 0.5% by mass, and particularly preferably 0.01 to 0.3% by mass.
Means for controlling the moisture content of the support to 0.5% by mass or less include (1) heat-treating the support at 100 ° C. or higher immediately before applying the coating solution for the image forming functional layer and other layers; And (3) controlling the relative humidity in the step of applying the coating liquid for the image forming functional layer and other layers, and (3) heat treating the support at 100 ° C. or higher before applying the coating liquid for the image forming functional layer and other layers. Then, cover and store with a moisture-proof sheet, and apply immediately after opening. These may be performed in combination of two or more.
[0058]
《Image forming functional layer》
The following materials can be contained in the image forming functional layer according to the present invention.
[0059]
(Water-soluble resin)
The feature of the present invention is that the image forming functional layer contains a water-soluble resin.
[0060]
Such a water-soluble resin is selected from hydrophilic natural polymers and synthetic polymers. Specific examples of the water-soluble resin preferably used in the present invention include, as natural polymers, gum arabic, water-soluble soybean polysaccharide, cellulose derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.), and denaturation thereof. For synthetic polymers such as solid, white dextrin, pullulan, enzymatically decomposed etherified dextrin, polyvinyl alcohol (preferably having a degree of saponification of 70 mol% or more), polyacrylic acid, an alkali metal salt or an amine salt thereof, and polyacrylic acid. Polymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine salt, vinyl alcohol / acrylic acid copolymer and its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxy Ethyl acrylate, polyvinyl Rupyrrolidone, its copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, its alkali metal salt or amine salt, poly-2 -Acrylamide-2-methyl-1-propanesulfonic acid copolymer, an alkali metal salt or an amine salt thereof. Also, depending on the purpose, two or more of these can be used in combination. However, the invention is not limited to these examples.
[0061]
(Crosslinking agent)
In the present invention, in order to prevent damage during printing and improve image strength, the image forming functional layer preferably contains a crosslinking agent capable of thermally crosslinking the water-soluble resin in addition to the water-soluble resin.
[0062]
Examples of the crosslinking agent capable of thermally crosslinking the water-soluble resin include polyfunctional compounds having crosslinking properties, such as epoxy compounds, polyamine compounds, isocyanate compounds, carbodiimide compounds, silane compounds, titanate compounds, aldehyde compounds, and polyvalent metal salts. And hydrazine.
[0063]
Specific examples of epoxy compounds include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, and bisphenol. Or a polycondensation product of a hydrogenated product thereof and epihalohydrin. Of the above, the water-soluble epoxy compound can also be used as a water-soluble resin. As the crosslinking agent in this case, the compounds described on pages 352 to 376 of the crosslinking agent handbook (Taiseisha, October 20, 1981, first edition, first edition) can be preferably used.
[0064]
Specific examples of the polyamine compound include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, propylenediamine, polyethyleneimine, and polyamidoamine.
[0065]
Specific examples of the isocyanate compound include tolylene diisocyanate, diphenyl methane isocyanate, liquid diphenyl methane diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, cyclohexanephenylene diisocyanate, isopropylbenzene-2,4-diisocyanate and the like. And aliphatic alicyclic diisocyanates such as cyclohexyl diisocyanate and isophorone diisocyanate, and addition products of polypropylene glycol / tolylene diisocyanate.
[0066]
Examples of the silane compound include methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-amino Propyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, dimethyldimethoxysilane Dimethyldiethoxysilane, diphenyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, vinyltris (methylethylketoxime) silane, methyltris (methylethylketoxime) silane, Sulfonyl triacetoxysilane, and the like.
[0067]
Examples of the titanate compound include tetraethyl orthosilicate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl triactanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl (dioctyl phosphate) titanate, and isopropyl tricumyl phenyl titanate. Isopropyl tri (N-aminoethylaminoethyl) titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, isopropyl triinstearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl phosphate) titanate, tetraisopropyl bis ( (Octylphosphite) titanate, tetraoctylbis (ditridisylphosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecylphosphite) titanate, bis (dioctylpyrophosphate) oxyacetate titanate And bis (dioctylpyrophosphate) oxyacetate titanate.
[0068]
Examples of the aldehyde compound include formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, glyoxal, glutaraldehyde, terephthalaldehyde, and the like.
[0069]
Examples of the polyvalent metal salt compound include water-soluble salts of metals such as zinc, calcium, magnesium, barium, strontium, cobalt, manganese, and nickel.
[0070]
Among the above-mentioned crosslinking agents, epoxy compounds, isocyanate compounds, carbodiimide compounds, silane compounds, aldehyde compounds, and polyvalent metal salt compounds are particularly preferably used.
[0071]
These crosslinking agents can be used alone or in combination of two or more. Among these crosslinking agents, a particularly preferred crosslinking agent is a water-soluble crosslinking agent, but a water-insoluble one can be used by dispersing it in water with a dispersant.
[0072]
Particularly preferred combinations of a water-soluble resin and a crosslinking agent include a carboxylic acid-containing water-soluble resin / carbodiimide compound, a carboxylic acid-containing water-soluble resin / epoxy compound, a hydroxyl group-containing resin / dialdehyde, and a hydroxyl group-containing resin / isocyanate compound. . A suitable addition amount of the crosslinking agent is 1 to 20% by mass of the water-soluble resin.
[0073]
Further, the image forming functional layer according to the present invention preferably contains heat fusible and / or heat fusible fine particles.
[0074]
(Heat-meltable fine particles)
The heat-meltable fine particles used in the present invention are fine particles formed of a material which is particularly low in viscosity when melted and is generally classified as a wax, among thermoplastic materials. The physical properties are preferably a softening point of 40 ° C. to 120 ° C. and a melting point of 60 ° C. to 150 ° C., and more preferably a softening point of 40 ° C. to 100 ° C. and a melting point of 60 ° C. to 120 ° C. If the melting point is lower than 60 ° C., the storage stability is a problem, and if the melting point is higher than 150 ° C., the ink deposition sensitivity decreases.
[0075]
Examples of usable materials include paraffin, polyolefin, polyethylene wax, microcrystalline wax, and fatty acid wax. These have a molecular weight of about 800 to 10,000, and these waxes may be oxidized to facilitate emulsification, and polar groups such as a hydroxyl group, an ester group, a carboxyl group, an aldehyde group, and a peroxide group may be introduced. Furthermore, in order to lower the softening point or to improve workability, these waxes include, for example, stearoamide, linolenamide, laurylamide, myristeramide, hardened bovine fatty acid amide, palmitoamide, oleic acid amide, rice sugar fatty acid amide, It is also possible to add coconut fatty acid amide or a methylolated product of these fatty acid amides, methylene bissteraloamide, ethylene bissteraloamide and the like. Further, a cumarone-indene resin, a rosin-modified phenol resin, a terpene-modified phenol resin, a xylene resin, a ketone resin, an acrylic resin, an ionomer, and a copolymer of these resins can also be used.
[0076]
Among these, it is preferable to contain any of polyethylene, microcrystalline, fatty acid ester, and fatty acid. These materials have relatively low melting points and low melt viscosities, so that high-sensitivity image formation can be performed. Further, since these materials have lubricity, damage when a shear force is applied to the surface of the printing plate material is reduced, and resistance to printing stains due to scratches and the like is improved.
[0077]
The heat-fusible fine particles are preferably dispersible in water, and the average particle size is preferably 0.01 to 10 μm, more preferably 0.05 to 3 μm. When the average particle diameter is smaller than 0.01 μm, when the coating liquid of the layer containing the heat-fusible fine particles is applied on a hydrophilic layer having a porous structure described later, the heat-fusible fine particles , Or into the gaps of fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause background contamination. When the average particle diameter of the heat-meltable fine particles is larger than 10 μm, the resolution is reduced.
[0078]
Further, the composition of the heat-fusible fine particles may be changed continuously between the inside and the surface layer, or may be covered with a different material. As a coating method, a known microcapsule forming method, a sol-gel method, or the like can be used.
[0079]
The content of the heat-fusible fine particles in the constituent layer is preferably from 1 to 90% by mass, more preferably from 5 to 80% by mass of the whole layer.
[0080]
(Heat-fusible fine particles)
Examples of the heat-fusible fine particles according to 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 polymer fine particles. The temperature is preferably lower than the decomposition temperature of the polymer fine particles. Further, the weight average molecular weight (Mw) of the high molecular polymer is preferably in the range of 10,000 to 1,000,000.
[0081]
Specific examples of the polymer constituting the polymer particles include, for example, polypropylene, polybutadiene, polyisoprene, diene (co) polymers such as 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) acrylates such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate-vinyl propionate copolymer, vinyl acetate-ethylene copolymer Vinyls such as 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.
[0082]
The polymer particles may be composed of a polymer polymerized by any known method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a gas phase polymerization method. As a method of forming fine particles of a polymer polymerized by a solution polymerization method or a gas phase polymerization method, a method of spraying a solution in an organic solvent of a high molecular polymer in an inert gas, drying and forming fine particles, A method in which a 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. Further, the heat-fusible fine particles and the heat-fusible fine particles may be used in any method as a dispersant or a stabilizer during polymerization or micronization, if necessary, for example, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyethylene. A surfactant such as glycol or a water-soluble resin such as polyvinyl alcohol may be used. Further, triethylamine, triethanolamine and the like may be contained.
[0083]
Further, the thermoplastic fine particles are preferably dispersible in water, and the average particle size 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, and when the coating liquid of the layer containing the heat-fusible fine particles is applied on a porous hydrophilic layer described later, the heat-fusible fine particles are coated on the hydrophilic layer. , Or into the gaps of fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause background contamination. When the average particle diameter of the heat-fusible fine particles is larger than 10 μm, the resolution is reduced.
[0084]
Further, the composition of the thermoplastic fine particles may be such that the composition of the inside and the surface layer is continuously changed, or may be covered with a different material. As a coating method, a known microcapsule forming method, a sol-gel method, or the like can be used.
[0085]
The content of the thermoplastic fine particles in the constituent layer is preferably from 1 to 90% by mass of the entire layer, more preferably from 5 to 80% by mass.
[0086]
It is also a preferred embodiment that the image forming functional layer according to the present invention contains a light-to-heat conversion material described later.
[0087]
The dry coating weight of the image forming functional layer is preferably 0.10 to 1.50 g / m.², More preferably 0.15 to 1.00 g / m²It is.
[0088]
<Hydrophilic layer>
The printing plate material of the present invention has a configuration having an image forming functional layer and having at least one hydrophilic layer between the support and the image forming functional layer. The hydrophilic layer provided between the support and the image forming functional layer will be described. The hydrophilic layer is defined as a layer having low affinity for ink and high affinity for water when the printing plate material of the present invention is used as a printing plate.
[0089]
As described in claim 2, in the printing plate material of the present invention, it is preferable that at least one of the hydrophilic layers provided on the support has a porous structure. In order to form the hydrophilic layer having the porous structure, the following materials for forming a hydrophilic matrix are preferably used.
[0090]
(Metal oxide)
As a material forming the hydrophilic matrix, a metal oxide is preferable. The metal oxide preferably contains metal oxide fine particles, and 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 in the range of 3 to 100 nm, and several kinds of metal oxide particles having different average particle diameters are used. Substance fine particles can also be used in combination. Further, the surface of the particles may be subjected to a surface treatment.
[0091]
The metal oxide fine particles can be used as a binder by utilizing the film forming property. Compared to the use of an organic binder, the decrease in hydrophilicity is less, so that it is suitable for use in a hydrophilic layer.
[0092]
(Colloidal silica)
Among them, colloidal silica can be particularly preferably used. Colloidal silica has the advantage of high film-forming properties even under relatively low-temperature drying conditions, and can provide good strength. The colloidal silica preferably includes a necklace-shaped colloidal silica described below, and fine-particle colloidal silica having an average particle size of 20 nm or less. Further, the colloidal silica preferably exhibits alkalinity as a colloid solution.
[0093]
Necklace-shaped colloidal silica is a general term for an aqueous dispersion of spherical silica having a primary particle diameter of the order of nm, and a spherical colloidal silica having a primary particle diameter of 10 to 50 nm is bonded to a length of 50 to 400 nm. Pearl necklace-shaped "colloidal silica.
[0094]
The pearl necklace shape (that is, pearl necklace shape) means that an image in which colloidal silica silica particles are connected and connected has a shape like a pearl necklace.
[0095]
The bonding 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 and bonded. Specific examples of the necklace-shaped colloidal silica include the “Snowtex-PS” series manufactured by Nissan Chemical Industries, and the product name is “Snowtex-PS-S (the average particle diameter of "About 110 nm)", "Snowtex-PS-M (average particle diameter in a connected state is about 120 nm)" and "Snowtex-PS-L (average particle diameter in a connected state is about 170 nm)". The corresponding acidic products are "Snowtex-PS-SO", "Snowtex-PS-MO" and "Snowtex-PS-LO".
[0096]
By adding necklace-shaped colloidal silica, the strength can be maintained while ensuring the porosity of the layer, and it can be preferably used as a porous material for the hydrophilic layer matrix. Among these, the use of alkaline “Snowtex PS-S”, “Snowtex PS-M”, and “Snowtex PS-L” improves the strength of the hydrophilic layer and increases the number of printed sheets. However, the occurrence of background dirt is suppressed, which is particularly preferable.
[0097]
It is known that colloidal silica has a stronger bonding force as the particle diameter is smaller. In the present invention, it is preferable to use colloidal silica having an average particle diameter of 20 nm or less, more preferably 3 to 15 nm. Things.
[0098]
As described above, among the colloidal silicas, alkaline ones are particularly preferable because they have a high effect of suppressing the occurrence of background fouling. Examples of the alkaline colloidal silica having an average particle diameter in this range include “Snowtex-20 (particle diameter 10 to 20 nm)” and “Snowtex-30 (particle diameter 10 to 20 nm)” manufactured by Nissan Chemical Industries, Ltd. "Snowtex-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 to 6 nm) ".
[0099]
The colloidal silica having an average particle size of 20 nm or less is particularly preferable because it can further improve the strength while maintaining the porosity of the layer to be formed by being used in combination with the necklace-shaped colloidal silica described above.
[0100]
The ratio of colloidal silica / necklace-shaped colloidal silica having an average particle size of 20 nm or less is preferably in the range of 95/5 to 5/95, more preferably 70/30 to 20/80, and more preferably 60/40. The range of 30 to 70/70 is more preferable.
[0101]
(Porous metal oxide particles)
In the present invention, porous metal oxide particles having a particle size of less than 1 μm can be contained as a porous material having a hydrophilic layer matrix structure. As the porous metal oxide particles, porous silica, porous aluminosilicate particles, or zeolite particles described below can be preferably used.
[0102]
(Porous silica, porous silica, porous aluminosilicate particles)
The porous silica particles are generally produced by a wet method or a dry method. In the wet method, a gel obtained by neutralizing an aqueous silicate solution can be dried and pulverized, or can be obtained by pulverizing a precipitate deposited by neutralization. In the dry method, it is obtained by burning silicon tetrachloride together with hydrogen and oxygen to precipitate silica. The porosity and particle size of these particles can be controlled by adjusting the production conditions. As the porous silica particles, those obtained from a gel obtained by a wet method are particularly preferable.
[0103]
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 a hydrolysis method using aluminum alkoxide and silicon alkoxide as main components. The particles can be synthesized in a ratio of alumina to silica of 1: 4 to 4: 1. Further, those produced as composite particles of three or more components by adding an alkoxide of another metal during the production can also be used in the present invention. The porosity and particle size of these composite particles can also be controlled by adjusting the production conditions.
[0104]
The porosity of the particles is preferably 0.5 ml / g or more in pore volume, more preferably 0.8 ml / g or more, and further preferably 1.0 to 2.5 ml / g. preferable. The pore volume is closely related to the water retention of the coating film, and the larger the pore volume, the better the water retention, the less the stain during printing, and the larger the water volume latitude. When the particle size is large, the particles themselves become very brittle, and the durability of the coating film is reduced. Conversely, if the pore volume is less than 0.5 ml / g, the printing performance may be slightly insufficient.
[0105]
(Method of measuring pore volume)
Here, it is assumed that the above pore volume is measured using Autosorb-1 (manufactured by Cantachrome Co., Ltd.) and that the voids of the powder are filled with nitrogen by nitrogen adsorption measurement using a constant volume method. Is calculated from the nitrogen adsorption amount at a relative pressure of 0.998.
[0106]
(Zeolite particles)
Zeolite is a crystalline aluminosilicate and is a porous body having pores of a regular three-dimensional network structure having a pore diameter of 0.3 nm to 1 nm. The general formula combining natural and synthetic zeolites is as follows:
[0107]
(M₁, (M₂)_0.5)_m(Al_mSi_nO₂)_{(M + n)}・ XH₂O
Where M₁, M₂Is an exchangeable cation and M₁Is Li⁺, Na⁺, K⁺, Tl⁺, Me₄N⁺(TMA), Et₄N⁺(TEA), Pr₄N⁺(TPA), C₇H_FifteenN²⁺, C₈H₁₆N⁺And M₂Is Ca²⁺, Mg²⁺, Ba²⁺, Sr²⁺, C₈H₁₈N₂ ²⁺And so on. 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 included, and thus the higher the polarity and, therefore, the higher the hydrophilicity. The preferred Al / Si ratio is 0.4 to 1.0, more preferably 0.8 to 1.0. x represents an integer.
[0108]
The zeolite particles used in the present invention are preferably synthetic zeolites having a stable Al / Si ratio and a relatively sharp particle size distribution. For example, zeolite A: Na₁₂(Al₁₂Si₁₂O₄₈) ・ 27H₂O: Al / Si ratio 1.0, zeolite X: Na₈₆(Al₈₆Si₁₀₆O₃₈₄) ・ 264H₂O: Al / Si ratio 0.811, zeolite Y: Na₅₆(Al₅₆Si₁₃₆O₃₈₄) ・ 250H₂O; an Al / Si ratio of 0.412;
[0109]
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 also greatly improved, and it is difficult to stain during printing, and the water flow latitude is widened. In addition, stains on fingerprint traces are greatly reduced. When the Al / Si ratio is less than 0.4, the hydrophilicity is insufficient, and the effect of improving the performance is reduced.
[0110]
In addition, the hydrophilic layer matrix structure constituting the hydrophilic layer can contain layered clay mineral particles. Examples of the layered mineral particles include clay minerals such as kaolinite, halloysite, talc, smectite (montmorillonite, beidellite, hectorite, savonite, etc.), vermiculite, mica (mica), chlorite, hydrotalcite, and layered polysilicic acid. Salts (kanemite, macatite, aialite, magadiite, kenyaite, etc.) and the like. In particular, 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 preferred charge density is 0.25 or more, more preferably 0.6 or more. Examples of the layered mineral having such a charge density include smectite (charge density of 0.25 to 0.6; negative charge), vermiculite (charge density of 0.6 to 0.9; negative charge), and the like. In particular, synthetic fluorine mica is preferable because it can be obtained in a stable quality such as a particle size. Further, among synthetic fluorine mica, swellable ones are preferable, and those that are free swelling are more preferable.
[0111]
Further, the above layered mineral intercalation compounds (eg, pillared crystals), those subjected to ion exchange treatment, and those subjected to surface treatment (silane coupling treatment, complexing treatment with organic binder, etc.) are also used. can do.
[0112]
As for the size of the tabular layered mineral particles, the average particle size (the maximum length of the particles) is less than 1 μm when contained in the layer (including the case of passing through the swelling step and the dispersion peeling step). The aspect ratio is preferably 50 or more. When the particle size is in the above range, continuity and flexibility in the planar direction, which are characteristics of the thin layered particles, are imparted to the coating film, and a crack is unlikely to be formed, and a tough coating film in a dry state can be obtained. Further, in a coating liquid containing a large amount of particles, sedimentation of the particles can be suppressed by the thickening effect of the layered clay mineral. If the particle size is larger than the above range, the coating film may be uneven and the strength may be locally reduced. When the aspect ratio is less than the above range, the number of tabular grains with respect to the added amount is small, the viscosity is insufficient, and the effect of suppressing the sedimentation of the grains is reduced.
[0113]
The content of the layered mineral particles is preferably from 0.1 to 30% by mass of the entire layer, more preferably from 1 to 10% by mass. In particular, swellable synthetic fluorine mica and smectite are preferable because the effect can be seen even in a small amount. The layered mineral particles may be added as a powder to the coating solution. However, in order to obtain a good degree of dispersion by a simple liquid preparation method (which does not require a dispersing step such as media dispersion), the layered mineral particles are used alone. After preparing a gel swollen in water with the above, it is preferable to add the gel to a coating solution.
[0114]
A silicate aqueous solution can also be used as another additive material in the hydrophilic layer matrix constituting the hydrophilic layer. Alkali metal silicates such as Na silicate, K silicate and Li silicate are preferred,₂/ M₂It is preferable to select the O ratio so that the pH of the entire coating solution when the silicate is added does not exceed 13, in order to prevent the dissolution of the inorganic particles.
[0115]
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 the inorganic polymer or the organic-inorganic hybrid polymer by the sol-gel method is described, for example, in “Application of the Sol-Gel Method” (written by Mio Sakuhana / published by Agne Shofusha) or described in this document. Known methods described in the cited documents can be used.
[0116]
Further, in the present invention, a water-soluble resin may be contained. Examples of the water-soluble resin include polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, styrene-butadiene copolymer, and conjugated diene-based polymer latex of methyl methacrylate-butadiene copolymer. And a resin such as an acrylic polymer latex, a vinyl polymer latex, polyacrylamide, and polyvinylpyrrolidone. As the water-soluble resin used in the present invention, it is preferable to use a polysaccharide.
[0117]
As the polysaccharide, starches, celluloses, polyuronic acid, pullulan and the like can be used, and particularly, cellulose derivatives such as methylcellulose salts, carboxymethylcellulose salts, and hydroxyethylcellulose salts are preferable, and sodium salts and ammonium salts of carboxymethylcellulose are preferable. More preferred. This is because the effect of forming the surface shape of the hydrophilic layer in a favorable state can be obtained by including the polysaccharide in the hydrophilic layer.
[0118]
It is preferable that the surface of the hydrophilic layer has an uneven structure with a pitch of 0.1 to 20 μm like the aluminum grain of the PS plate, and the unevenness improves the water retention and the retention of the image area. 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 aqueous solution are added to the coating solution for the hydrophilic layer. When the hydrophilic layer is applied and dried by forming a phase separation when the hydrophilic layer is applied, a structure having better printability can be obtained, which is preferable.
[0119]
The form of the concavo-convex structure (such as pitch and surface roughness) depends on the type and amount of alkaline colloidal silica, the type and amount of water-soluble polysaccharide, the type and amount of other additives, the solid content concentration of the coating solution, and the wetness. It can be appropriately controlled by the film thickness, drying conditions and the like.
[0120]
In the present invention, the water-soluble resin added to the hydrophilic matrix structure preferably exists at least partially in a water-soluble state while being soluble in water. This is because, even when a water-soluble material is cross-linked by a cross-linking agent or the like and becomes insoluble in water, its hydrophilicity is reduced and printability may be deteriorated. Further, a cationic resin may be further contained. Examples of the cationic resin include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine or derivatives thereof, tertiary amino groups and quaternary ammonium groups. Acrylic resin, diacrylamine and the like. The cationic resin may be added in the form of fine particles, for example, a cationic microgel described in JP-A-6-161101.
[0121]
Further, the coating liquid used for coating the hydrophilic layer according to the present invention can contain a water-soluble surfactant for the purpose of improving coatability, etc., such as a Si-based or F-based surfactant. Although a surfactant can be used, it is particularly preferable to use a surfactant containing a Si element, since there is no fear of causing printing stains. The content of the surfactant is preferably from 0.01 to 3% by mass, more preferably from 0.03 to 1% by mass of the entire hydrophilic layer (solid content as a coating solution).
[0122]
Further, the hydrophilic layer may contain a phosphate. In the present invention, since the coating solution for the hydrophilic layer is preferably alkaline, it is preferable to add phosphate as trisodium phosphate or disodium hydrogenphosphate. By adding the phosphate, an effect of improving the mesh opening at the time of printing can be obtained. The amount of the phosphate added is preferably 0.1 to 5% by mass, more preferably 0.5 to 2% by mass, as an effective amount excluding the hydrate.
[0123]
Further, a light-to-heat conversion material described below can be contained. In the case of a particulate material, the light-to-heat conversion material preferably has a particle size of less than 1 μm.
[0124]
(Inorganic particles having a particle size of 1 μm or more or particles coated with an inorganic material)
As the inorganic particles that can be used in the present invention, for example, known metal oxide particles such as silica, alumina, titania, and zirconia can be used, but in order to suppress sedimentation in the coating solution, a porous material is used. It is preferable to use fine metal oxide particles. As the porous metal oxide particles, the aforementioned porous silica particles and porous aluminosilicate particles can be preferably used.
[0125]
Examples of the particles coated with an inorganic material include particles in which organic particles such as polymethyl methacrylate and polystyrene are used as a core material and coated with inorganic particles having a smaller particle size than the core material particles. The particle size of the inorganic particles is preferably about 1/10 to 1/100 of the core material particles. As the inorganic particles, similarly, known metal oxide particles such as silica, alumina, titania, and zirconia can be used. As the coating method, various known methods can be used.However, the core material particles and the coating material particles collide with each other at high speed in the air such as a hybridizer to dig the coating material particles into the surface of the core material particles. A dry coating method of fixing and coating can be preferably used.
[0126]
Further, particles obtained by plating a core material of organic particles with metal 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.
[0127]
The particle size is preferably from 1 to 10 μm, more preferably from 1.5 to 8 μm, and particularly preferably from 2 to 6 μm.
[0128]
In the present invention, the amount of particles having a particle size of 1 μm or more is preferably 1 to 50% by mass, more preferably 5 to 40% by mass of the entire hydrophilic layer. For the entire hydrophilic layer, a low content ratio of a carbon-containing material such as an organic resin or carbon black is preferable for improving hydrophilicity, and the total of these materials is preferably less than 9% by mass. And more preferably less than 5% by mass.
[0129]
<< Hydrophilic overcoat layer >>
In the present invention, it is preferable to have a hydrophilic overcoat layer on the image forming functional layer in order to prevent damage during handling. The hydrophilic overcoat layer may be a layer immediately above the image forming function layer, or an intermediate layer may be provided between the image forming function layer and the hydrophilic overcoat layer. Preferably, the hydrophilic overcoat layer is removable on a printing press.
[0130]
In the present invention, the hydrophilic overcoat layer preferably contains a water-soluble resin or a water-swellable resin obtained by partially cross-linking the water-soluble resin. As the water-soluble resin, those contained in the image forming functional layer are used.
[0131]
In the present invention, the hydrophilic overcoat layer can contain a light-to-heat conversion material described below.
[0132]
In addition, in order to prevent the printing plate of the present invention from being damaged when the printing plate of the present invention is mounted on a laser recording apparatus or a printing machine, it is preferable in the present invention that the overcoat layer contains a matting agent having an average particle size of 1 μm or more and less than 20 μm.
[0133]
Preferred examples of the matting agent include inorganic fine particles having a new Mohs hardness of 5 or more and organic matting agents. Examples of the inorganic fine particles having a new Mohs hardness of 5 or more include metal oxide particles (silica, alumina, titania, zirconia, iron oxide, chromium oxide, and the like), metal carbide particles (silicon carbide, and the like), boron nitride particles, and diamond particles. No. Examples of the organic matting agent include starch described in U.S. Pat. No. 2,322,037, starch derivatives described in BE 625,451 and GB 981,198, etc., and JP-B-44-3643. Etc., polystyrene or polymethacrylate described in CH330,158, etc., polyacrylonitrile described in US Pat. No. 3,079,257, US Pat. No. 3,022,169. Examples thereof include polycarbonates described in the specification and the like.
[0134]
The added amount of these matting agents is 1 m²It is preferably 0.1 g or more and less than 10 g.
[0135]
In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of aqueous solution application for the purpose of ensuring uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearate, polyoxyethylene nonyl phenyl ether, polyoxyethylene dodecyl ether, and the like. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by mass, and more preferably 1 to 3% by mass.
[0136]
In the present invention, the dry coating amount of the overcoat layer is 0.05 to 1.5 g / m²Is more preferable, and a more preferable range is 0.1 to 0.7 g / m.²It is. Within this range, good stain prevention, scratch prevention, fingerprint mark adhesion prevention, and ablation scum generation can be achieved without impairing the removability of the overcoat layer on the printing press.
[0137]
《Light-to-heat conversion material》
The image forming functional layer, the hydrophilic layer, the hydrophilic overcoat layer, and other layers provided in the invention preferably contain a photothermal conversion material.
[0138]
As the light-to-heat conversion material, an infrared absorbing dye or pigment can be added.
(Infrared absorbing dye)
Organic compounds such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, and anthraquinone dyes, which are common infrared absorbing dyes, phthalocyanine, naphthalocyanine And azo-based, thioamide-based, dithiol-based and indoaniline-based 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, and 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-3-42281 Compounds described in JP-A-3-97589, JP-A-3-103476, JP-A-7-43851, JP-A-7-102179, JP-A-2001-117201 and the like can be mentioned. These can be used alone or in combination of two or more.
[0139]
Examples of the pigment include carbon, graphite, metal, and metal oxide. It is particularly preferable to use furnace black or acetylene black as carbon. The particle size (d50) is preferably 100 nm or less, more preferably 50 nm or less.
[0140]
As 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.
[0141]
Any metal can be used as long as it is fine particles having a particle size of 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 sphere, a piece, and a needle. In particular, colloidal metal fine particles (Ag, Au, etc.) are preferable.
[0142]
As the metal oxide, a material exhibiting black in the visible light region, or a material having conductivity or a semiconductor itself can be used. Materials exhibiting black in the visible light range include black iron oxide (Fe₃O₄) And black composite metal oxides containing two or more metals described above. The metal oxide is a black composite metal oxide composed of oxides of two or more metals. 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 are obtained by the methods disclosed in JP-A-8-27393, JP-A-9-25126, JP-A-9-237570, JP-A-9-241529, JP-A-10-231441 and the like. Can be manufactured. The composite metal oxide that can be 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 a treatment disclosed in JP-A-8-27393 in order to reduce the elution of hexavalent chromium. These composite metal oxides have good coloring with respect to the amount added, that is, good light-to-heat conversion efficiency. These composite metal oxides preferably have an average primary particle diameter of 1 μm or less, and more preferably 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 light-to-heat conversion ability with respect to the addition amount becomes better, and when the average primary particle diameter is in the range of 0.01 to 0.5 μm, the light-to-heat conversion ability with respect to the addition amount is improved. It will be better. However, the light-to-heat conversion ability with respect to the added amount is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Therefore, it is preferable that these composite metal oxide particles are dispersed by a known method before being added to the coating solution for the layer to prepare a dispersion (paste). If the average primary particle diameter is less than 0.01, dispersion becomes difficult, which is not preferable. For dispersion, a dispersant can be used as appropriate. The amount of the dispersant added is preferably 0.01 to 5% by mass, more preferably 0.1 to 2% by mass, based on the composite metal oxide particles. The type of the dispersant is not particularly limited, but it is preferable to use a Si-based surfactant containing a Si element.
[0143]
Examples of the material having conductivity or being a semiconductor include, for example, SnO doped with Sb.₂(ATO), In with Sn added₂O₃(ITO), TiO2, TiO₂(Titanium oxynitride, generally titanium black) or the like. In addition, a core material (BaSO₄, TiO₂, 9Al₂O₃・ 2B₂O, K₂O ・ nTiO₂Etc.) can also be used. Their particle size is 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less.
[0144]
A particularly preferred embodiment of the photothermal conversion material is that the infrared absorbing dye and the metal oxide are black composite metal oxides composed of oxides of two or more metals.
[0145]
The addition amount of these light-to-heat conversion materials is 0.1 to 50% by mass, preferably 1 to 30% by mass, and more preferably 3 to 25% by mass with respect to each layer.
[0146]
《Visibility enhancement》
Generally, in the printing industry, there is a work of plate inspection for checking whether an image is correctly formed before printing a printing plate on which an image is formed on a printing material. In order to perform plate inspection, it is preferable that the image formed before printing has good performance on the plate surface, that is, good visibility. Since the printing plate material of the present invention is a processless printing plate material that can be printed without development processing, it is preferable that the optical density of an exposed portion or an unexposed portion be changed by light or heat by exposure.
[0147]
As a method preferably used in the present invention, a method containing a cyanine-based infrared-absorbing dye whose optical density changes upon exposure, a method using a photoacid generator and a compound which changes its color by an acid, and color formation such as a leuco dye There is a method of using a combination of an agent and a developer.
[0148]
In the present invention, the photoacid generator means a compound that generates a Lewis acid or a Bronsted acid upon exposure.
[0149]
Specific examples of the photoacid generator include a diazo compound, an orthoquinonediazide compound, a polyhalogen compound, and an onium salt compound. Further, compounds in which these structures are incorporated in a polymer can also be used.
[0150]
Examples of the diazo compound include diazonium salts disclosed in U.S. Pat. Nos. 2,063,631 and 2,667,415 and organic compounds containing a reactive carbonyl group such as aldol and acetal. A diphenylamine-p-diazonium salt, which is a reaction product with a binder, and a formaldehyde condensation product, and these water-soluble diazonium salt compounds were prepared by the method disclosed in JP-A-54-98613.^4-, PF^6-And halogenated Lewis acid salts, allyldiazonium salt compounds, etc. substituted with an anion component or the like.
[0151]
The orthoquinone diazide compound is a compound having at least one orthoquinone diazide group in one molecule, such as 1,2-naphthoquinone-2-diazide-5-sulfonic acid-ethyl ester, 1,2-naphthoquinone-2-diazide-5. -Sulfonic acid-isobutyl ester, 1,2-naphthoquinone-2-diazido-5-sulfonic acid-phenyl ester, 1,2-naphthoquinone-2-diazide-5-sulfonic acid-α-naphthyl ester, 1,2-naphthoquinone -2-diazido-5-sulfonic acid-benzyl ester, 1,2-naphthoquinone-2-diazido-4-sulfonic acid-phenyl ester, 1,2-naphthoquinone-2-diazide-4-sulfonic acid-ethylamide, 1, 2-Naphthoquinone-2-diazide-4-sulfonic acid-fe Ruamido and the like.
[0152]
As the polyhalogen compound, acetophenone containing polyhalogen, for example, tribromoacetophenone, trichloroacetophenone, o-nitro-tribromoacetophenone, p-nitro-tribromoacetophenone, m-nitro-tribromoacetophenone, m-bromo-tribromo Acetophenone, p-bromo-tribromoacetophenone and the like; and sulfoxides containing polyhalogen, such as bis (tribromomethyl) sulfoxide, dibromomethyl-tribromomethylsulfoxide, tribromomethyl-phenylsulfoxide and the like. Also, sulfones containing polyhalogens, for example, bis (tribromomethyl) sulfone, trichloromethyl-phenylsulfone, tribromomethyl-phenylsulfone, trichloromethyl Other polyhalogen-containing pyrone compounds, triazine compounds, oxadiazole compounds such as ru-p-chlorophenylsulfone, tribromomethyl-p-nitrophenylsulfone 2-trichloromethylbenzothiazolesulfone, 2,4-dichlorophenyl-trichloromethylsulfone, etc. And the like.
[0153]
Onium salt compounds and other photoacid generators include S.I. P. Papas, et al. , Polym. Photochem. , 5, 1, pp. 104-115 (1984), and Ph. Introduced in Coloring Materials, 66 (2), pp. 104-115 (1993).₂I⁺/ SbF^6-A photoacid generator represented by a diallyliodonium salt compound such as, a triallylsulfonium salt compound, a triallyl selenonium salt compound, a dialkylphenacylsulfonium salt compound, a dialkyl-4-phenacylsulfonium salt compound, α -Hydroxymethylbenzoin sulfonate, N-hydroxyiminosulfonate, α-sulfonyloxy ketone, β-sulfonyloxy ketone, iron-arene complex compound (benzene-cyclopentadienyl-iron (II) hexafluorophospho Phosphate, etc.), o-nitrobenzylsilyl ether compound, benzoin tosylate, tri (nitrobenzyl) phosphate and the like.
[0154]
Other examples include ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, organic halogen compounds, o-nitrobenzyl derivatives, iminosulfonates and disulfone compounds.
[0155]
More specifically, for example, compounds represented by the formulas T-1 to T-15 described in Chemical formulas 7 to 9 of JP-A-9-244226 can be exemplified.
[0156]
Among these, more preferred are s-triazine compounds having two or more trihalomethyl groups, and particularly preferred is tris (trichloromethyl) -s-triazine. The content of these photoacid generators is 0.01 to 40% by mass, and preferably 0.1 to 30% by mass, based on the total solid content of the printing plate material.
[0157]
In the present invention, as the compound that changes color by an acid, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used. .
[0158]
Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanil yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.), Oil Blue # 603 (Orient Chemical Co., Ltd.) Oil Pink # 312 (manufactured by Orient Chemical Industry), Oil Red 5B (manufactured by Orient Chemical Industry), Oil Scarlet # 308 (manufactured by Orient Chemical Industry), Il Red OG (Orient Chemical Co., Ltd.), Oil Red RR (Orient Chemical Co., Ltd.), Oil Green # 502 (Orient Chemical Co., Ltd.), Spiron Red BEH Special (Hodogaya Chemical Co., Ltd.), m-cresol purple, cresol red , Rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylaminophenyliminonaphthoquinone, 2-carbostarylamino-4-p-dihydrooxyethyl Amino-phenylimino naphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone and the like. It is.
[0159]
In addition, an organic dye such as an arylamine can be used as a compound that develops a color with an acid. Arylamines suitable for this purpose include not only simple arylamines such as primary and secondary aromatic amines, but also so-called leuco dyes, examples of which include the following.
[0160]
Diphenylamine, dibenzylaniline, triphenylamine, diethylaniline, diphenyl-p-phenylenediamine, p-toluidine, 4,4'-biphenyldiamine, o-chloroaniline, o-bromoaniline, 4-chloro-o-phenylenediamine , O-bromo-N, N-dimethylaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, aniline, 2,5-dichloroaniline, N-methyldiphenylamine, o-toluidine, p, p'- Tetramethyldiaminodiphenylmethane, N, N-dimethyl-p-phenylenediamine, 1,2-dianilinoethylene, p, p ′, p ″ hexamethyltriaminotriphenylmethane (leuco crystal violet), p, p′-tetra Methyldiamino Riphenylmethane, p, p'-tetramethyldiaminodiphenylmethylimine, p, p ', p "-triamino-o-methyltriphenylmethane, p, p', p" -triaminotriphenylcarbinol, p, p p'-tetramethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p "-triaminophenylmethane, p, p', p" -hexapropyltriaminotriphenylmethane and the like.
[0161]
In the present invention, as the color developer, any acidic substance used as an electron acceptor in the thermosensitive recording medium can be used.For example, acidic clay clay kaolin, inorganic acids such as zeolite, aromatic carboxylic acids, anhydrides thereof, or the like. Metal salts, organic sulfonic acids, other organic acids, phenolic compounds, methylolates of the phenolic compounds, organic developers such as salts or complexes of the phenolic compounds, and the like, among which phenolic compounds Preference is given to methylolates and salts of phenolic compounds (hereinafter also including complex salts, unless otherwise specified).
[0162]
Among these developers, specific examples of organic developers include phenol, 4-phenylphenol, 4-hydroxyacetophenone, 2,2'-dihydroxydiphenyl, and 2,2'-methylenebis (4-chlorophenol). 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-isopropylidenediphenol (also known as bisphenol A), 4,4'-isopropylidenebis (2-chlorophenol), 4,4'-isopropylidenebis (2-methylphenol), 4,4'ethylenebis (2-methylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), 1,1- Bis (4-hydroxyphenyl) -cyclohexane, 2,2'-bis (4-hydroxyphenyl) -n-heptane, 4,4'- Phenolic compounds such as clohexylidenebis (2-isopropylphenol) and 4,4'-sulfonyldiphenol, methylolated products of the phenolic compounds, salts of the phenolic compounds salicylic acid anilide, novolak phenolic resins, Benzyl hydroxybenzoate and the like.
[0163]
In the present invention, a leuco dye such as a triphenylmethanelactone type can be used as the color former used together with the color developer.
[0164]
Such leuco dyes include, for example, crystal violet lactone, 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) aminofluoran, malachite green lactone, 3,3-bis (1-ethyl-2-methyldol-3-yl) phthalide, 3-diethylamino-6-methyl -7-anilinofluoran, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) fluoran, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilino Fluorane, 3-piperidino-6-methyl-7-anilinofluoran and the like.
[0165]
The color former and the color developer are usually used in a range in which the weight ratio of the color developer / the color former is 0.1 / 1 to 5/1, and especially, the weight ratio is 0.5 / 1 to 3 /. A range of 1 is preferable.
[0166]
<< Constituent layer on the opposite side of image forming functional layer >>
In the present invention, it is preferable that the support has at least one constituent layer on the side of the support opposite to the image forming functional layer in order to prevent a change in physical properties during the handling. Preferred constituent layers are an undercoat layer, a hydrophilic binder-containing layer and a hydrophobic binder-containing layer, and the binder-containing layer may be provided on the undercoat layer.
[0167]
As the undercoat layer, the above-described undercoat layer of the support is preferable.
The hydrophilic binder is not particularly limited as long as it is hydrophilic, but polyvinyl alcohol (PVA), which is a resin having a hydroxyl group as a hydrophilic structural unit, cellulose resin (methyl cellulose (MC), ethyl cellulose (EC), Hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), etc.), chitins and starch; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE), which are resins having an ether bond. Polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP), which are resins having an amide group or an amide bond. Also, polyacrylates having a carboxyl group as a dissociable group, maleic acid resins, alginates and gelatins; polystyrene sulfonates having a sulfone group; amino groups, imino groups, tertiary amines and quaternary ammonium salts. Polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPAm), polyvinylpyridine and gelatins.
[0168]
The hydrophobic binder is not particularly limited as long as it is hydrophobic as the binder. For example, polymers derived from α, β-ethylenically unsaturated compounds, such as polyvinyl chloride, post-chlorinated polyvinyl chloride, and vinyl chloride Made from copolymers of vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, made of polyvinyl alcohol as a starting material, only part of the vinyl alcohol units react with aldehydes repeatedly. Polyvinyl acetals, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylates, polymethacrylates, polystyrene and polyethylene or mixtures thereof.
[0169]
Further, the hydrophobic binder may be one obtained from an aqueous dispersion resin (polymer latex) described in paragraphs 0033 to 0038 of JP-A-2002-258469, as long as the finished printing plate material surface is hydrophobic. .
[0170]
In addition, in order to prevent color misregistration in color printing due to misregistration of the printing plate during printing during printing, and to prevent color misregistration due to misregistration of the printing plate during printing, the average particle size of the outermost surface layer of the constituent layers is set in the present invention. It is preferable to include a matting agent having a diameter of 1 μm or more and less than 20 μm.
[0171]
Preferred examples of the matting agent include inorganic fine particles having a new Mohs hardness of 5 or more and organic matting agents. Examples of the inorganic fine particles having a new Mohs hardness of 5 or more include metal oxide particles (silica, alumina, titania, zirconia, iron oxide, chromium oxide, and the like), metal carbide particles (silicon carbide, and the like), boron nitride particles, and diamond particles. No. Examples of the organic matting agent include starch described in US Pat. No. 2,322,037, starch derivatives described in BEP 625,451 and GBP 981,198, etc., and JP-B-44-3643. Polyvinyl alcohol, polystyrene or polymethacrylate described in CHP 330,158, etc., polyacrylonitrile described in US Pat. No. 3,079,257, etc., and polycarbonate described in US Pat. No. 3,022,169, etc. can give.
[0172]
The added amount of these matting agents is 1 m²It is preferably 0.1 g or more and less than 10 g.
[0173]
In the present invention, the surface roughness of the surface on the opposite side of the image forming layer is adjusted to a Ra value of 0.1 μm or more and less than 2 μm by adjusting the particle size of the matting agent, the amount added and the amount of the binder. It is preferable that If the thickness is less than 0.1 μm, there is a concern that there is a problem in the transportability of the printing plate material due to a high friction coefficient or the like, or a problem may occur in attaching the printing plate material to a printing machine. On the other hand, a rough surface of 2 μm or more may damage the coating layer formed on the opposite surface when the printing plate material is wound around a roll during manufacturing or other reasons. There is also a concern that the printing plate material surface partially protrudes due to pushing up from the side, and printing pressure concentrates on that portion, resulting in poor printing durability.
[0174]
Further, the laser recording device or the processless printing machine has a sensor for controlling the transport of the printing plate inside the device, and in order to perform these controls without delay, in the present invention, in the constituent layers, Preferably contains a dye and a pigment. As the coloring matter and the pigment, the infrared absorbing coloring matter and the pigment used in the above-mentioned light-to-heat conversion material are preferably used. Further, the constituent layer may contain a known surfactant.
[0175]
"exposure"
The present invention also provides a printing method including a step of forming an image on a printing plate material using a thermal head or a thermal laser, and then removing a non-image portion of the image forming layer on a printing machine.
[0176]
Since the image formation of the printing plate material of the present invention can be performed by heat, it is possible to form an image by a thermal head used in a thermal printer, but it is particularly preferable to perform image formation by exposure with a thermal laser. .
[0177]
Regarding the exposure according to the present invention, more specifically, scanning exposure using a laser that emits light in the infrared and / or near-infrared region, that is, emits light in a wavelength range of 700 to 1500 nm is preferable. Although a gas laser may be used as the laser, it is particularly preferable to use a semiconductor laser that emits light in the near infrared region.
[0178]
As an apparatus suitable for the scanning exposure of the present invention, any apparatus can be used as long as it can form an image on the surface of a printing plate material in response to an image signal from a computer using the semiconductor laser. Good.
[0179]
In general,
(1) a method in which the printing plate material held by the plate-shaped holding mechanism is subjected to two-dimensional scanning using one or a plurality of laser beams to expose the entire printing plate material,
(2) On the printing plate material held along the cylindrical surface inside the fixed cylindrical holding mechanism, using one or a plurality of laser beams from inside the cylinder, the circumferential direction of the cylinder (main scanning direction) ), While moving in the direction perpendicular to the circumferential direction (sub-scanning direction) while scanning, the entire surface of the printing plate material is exposed,
(3) A printing plate material held on the surface of a cylindrical drum that rotates around an axis as a rotating body is rotated in the circumferential direction (main scanning direction) by rotating the drum using one or more laser beams from outside the cylinder. ), While moving in a direction perpendicular to the circumferential direction (sub-scanning direction), and exposing the entire surface of the printing plate material.
[0180]
In the present invention, the scanning exposure method (3) is particularly preferable, and the exposure method (3) is particularly used in an apparatus that performs exposure on a printing apparatus.
[0181]
The printing plate material on which an image has been formed in this way can be printed without performing a developing process. The printing plate material after image formation is directly attached to the plate cylinder of the printing press, or the printing plate material is attached to the plate cylinder of the printing press to form an image, and the water supply roller and / or ink is supplied while rotating the plate cylinder. The non-image portion of the image forming layer can be removed by bringing the roller into contact with the printing plate material.
[0182]
The step of removing the non-image portion of the image forming layer in the printing plate material of the present invention can be performed in a normal printing sequence using a PS plate, so that there is no need to extend the working time by so-called on-press development processing. Therefore, it is effective for cost reduction.
[0183]
Furthermore, in the printing method of the present invention, it is preferable that the printing method further includes a step of drying the surface of the printing plate material after the image is formed and before the surface of the printing plate material and the water supply roller or the ink supply roller are in contact with each other on the printing press. . In the printing method of the present invention, it is considered that the image intensity gradually increases immediately after image formation. In a general external drum method using a thermal laser (the method (3) described above), it generally takes about 3 minutes from the start to the end of exposure, so that the image intensity differs between the exposure start part and the end part at the end of exposure. There are concerns. By providing the drying step, the difference in image intensity can be reduced to a level that does not cause any problem.
[0184]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
[0185]
Example 1
<< Preparation of support >>
Preparation of polyester film
(Polyethylene terephthalate 1; PET1)
Using terephthalic acid and ethylene glycol, PET having an IV (intrinsic viscosity) of 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.) was obtained according to a conventional method. This is pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, quenched on a cooling drum at 50 ° C., and heat-fixed so that the average film thickness becomes 190 μm. A stretched film was produced. This was longitudinally stretched at a stretching temperature of 1.0 times at 102 ° C. in the former stretching and at a stretching temperature of 4.1 times at 110 ° C. in the latter stretching. Then, it was transversely stretched 6 times at 120 ° C. with a tenter. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends, and after cooling to 40 ° C., winding was performed at 8.5 kg / m. The width (film formation width) of the PET film thus obtained was 2.5 m.
[0186]
(Polyethylene terephthalate 2; PET2)
Using terephthalic acid and ethylene glycol, PET having an IV (intrinsic viscosity) of 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.) was obtained according to a conventional method. This is pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, quenched on a cooling drum at 50 ° C., and heat-fixed so that the average film thickness becomes 190 μm. A stretched film was produced. This was longitudinally stretched at a stretching temperature of 1.3 times at 102 ° C. in the former stretching and 2.6 times at 110 ° C. in the latter stretching. Then, it was horizontally stretched 4.5 times at 120 ° C. with a tenter. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends, and after cooling to 40 ° C., winding was performed at 4.8 kg / m. The width (film formation width) of the PET film thus obtained was 2.5 m.
[0187]
(Polyethylene-2,6-naphthalate; PEN3)
PEN having an IV (intrinsic viscosity) = 0.55 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.) using methyl 2,6-naphthalenedicarboxylate and ethylene glycol according to a conventional method. Was. This was pelletized, dried at 150 ° C. for 4 hours, melted at 310 ° C., extruded from a T-die, and rapidly cooled on a cooling drum at 80 ° C. to produce an unstretched film. This was longitudinally stretched by 1.2 times at 132 ° C. in the first stage stretching and 2.7 times by 140 ° C. in the second stage stretching. Then, the film was transversely stretched 4.0 times at 145 ° C. with a tenter. After that, it was heat-set at 250 ° C. for 20 seconds and relaxed 4% in the horizontal direction at the same temperature. After slitting the chuck portion of the tenter, knurling was performed on both ends, and after cooling to 40 ° C., winding was performed at 4.8 kg / m. The width (film forming width) of the PEN film thus obtained was 2.5 m. The average film thickness (μm) of PEN3 was 190 μm.
[0188]
《Preparation of undercoated support》
8 W / m on both sides of each of the film supports of PET1, 2 and PEN3 obtained above.²And a corona discharge treatment for one minute, and then, as shown in Table 4, apply the following undercoating coating solution a-1 or a-2 on one surface so as to have a dry film thickness of 0.8 μm. The undercoating coating solution b was applied and dried at 180 ° C. for 4 minutes (undercoating surface A). Further, the following conductive layer and intermediate layer were sequentially coated on the opposite surface and dried at 180 ° C. for 4 minutes, and the following undercoating coating solution c-1 or c-2 was coated on these layers with a dry film thickness of 0.8 μm. And dried at 180 ° C. for 4 minutes (undercoating surface B). After application, the surface electric resistance at 25 ° C. and 25% RH is 10⁹Ω. When the surface roughness of the surface on the side of the undercoating surface B was measured, the Ra value was 0.8 μm. In addition, about each layer coating liquid, the composition was shown by the applied amount after application.
[0189]
Next, the surface of each undercoat layer was subjected to plasma processing under the following plasma processing conditions.
[0190]

[0191]
Embedded image

[0192]

《Plasma treatment conditions》
Using a batch type atmospheric pressure plasma processing apparatus (AP-I-H-340, manufactured by EC Chemical Co., Ltd.), high-frequency output was 4.5 kW, frequency was 5 kHz, processing time was 5 seconds, and argon was used as a gas condition. Plasma treatment was performed with nitrogen and hydrogen at a volume ratio of 90% and 5%, respectively.
[0193]
A tension of 0.008 kg / mm with respect to the support after slitting to 1.25 m width.²At 180 ° C. for 30 seconds.
[0194]
<< Preparation of printing plate materials 101-105 >>
Immediately before applying the hydrophilic layer, the undercoated support was dried by applying a heat treatment at 130 ° C. for 30 seconds, and was covered with a moisture-proof sheet to prevent moisture in the air from entering. When a part of the support sample was sampled and the water content was measured, PET1 was 1.2%, PET2 was 0.2%, and PEN3 was 0.2%. With respect to those covered, the sheet was removed and immediately applied.
[0195]
Coating solution for hydrophilic layer 1 shown in Table 1 (preparation method is shown below), coating solution for hydrophilic layer 2 shown in Table 2 (preparation method is shown below), and image forming functional layer coating shown in Table 3 The solution 1 and the coating solution 2 for the image forming functional layer were coated on the surface A of each of the subbed supports using a wire bar.
[0196]
Sample 101 was prepared by coating the image forming functional layer coating solution 1 on the undercoated support shown in Table 4 with a wire bar at a dry weight of 0.6 g / m 2.²After drying at 50 ° C. for 3 minutes, the hydrophilic layer 1 and the hydrophilic layer 2 were each dried in an order of 2.7 g / m using a wire bar in the order of hydrophilic layer 1 and hydrophilic layer 2.²0.7g / m²And dried at 120 ° C. for 3 minutes.
[0197]
Samples 102 to 105 each had a drying amount of 2.7 g / m2 using a wire bar on the undercoated support shown in Table 4 in the order of hydrophilic layer 1 and hydrophilic layer 2.²0.7g / m²After drying at 120 ° C. for 3 minutes, a heat treatment was performed at 60 ° C. for 24 hours. Thereafter, the coating amount of the image forming functional layer shown in Table 3 was dried using a wire bar at a coating weight of 0.6 g / m 2.²After drying at 50 ° C. for 3 minutes, a seasoning treatment was performed at 50 ° C. for 72 hours.
[0198]
<Preparation of coating liquid for hydrophilic layer 1>
Each material shown in Table 1 was sufficiently stirred and mixed using a homogenizer, and then mixed with the composition shown in Table 1 and filtered to prepare a coating solution for the hydrophilic layer 1.
[0199]
The details of each material are as follows, and the numerical values in the table represent parts by mass.
[0200]
[Table 1]

[0201]
<Preparation of coating liquid for hydrophilic layer 2>
Each material shown in Table 2 was sufficiently stirred and mixed using a homogenizer, and then mixed with the composition shown in Table 2 and filtered to prepare a coating solution for the hydrophilic layer 2.
[0202]
[Table 2]

[0203]
<Preparation of coating solution for image forming functional layer>
[0204]
[Table 3]

[0205]
<< Evaluation of printing plate materials 101-105 >>
(A) Image formation by infrared laser method
The samples of the printing plate materials 101 to 105 prepared as described above were stored for 3 days under thermo-conditions of 50 ° C. and 80% RH as substitute conditions for preservation. The sample was wound around an exposure drum and fixed. For the exposure, a laser beam having a wavelength of 830 nm and a spot diameter of about 18 μm was used, and the exposure energy was 300 mJ / cm.²The image was formed with 175 lines at 2400 dpi (dpi represents the number of dots per 2.54 cm), and printing plate samples 101 to 105 were produced.
[0206]
(B) The printing plate samples 101 to 105 on which the images were formed were evaluated for various properties as printing plates by the following printing method.
[0207]
《Printing method》
As a printing device, DAIYA1F-1 manufactured by Mitsubishi Heavy Industries, Ltd. was used. A coated paper, a 2% by mass solution of Astromark 3 (manufactured by Niken Kagaku Kenkyusho) as dampening solution, and Toyo manufactured by Toyo Ink Co., Ltd. as ink were used. Printing was performed using King Hi Echo M Beni. The printing start sequence was a PS plate printing sequence, and no special on-press development operation was performed. When the plate surface was observed after printing, the non-image portion of the material according to the present invention was removed.
[0208]
<< Evaluation of ink inking property >>
After printing 1000 sheets, the supply of ink was stopped and only water was supplied for 5 minutes. Thereafter, the supply of the ink was restarted, and the ink was deposited to evaluate the number of printed sheets having a normal ink density. The smaller the number of sheets, the better the ink inking property.
[0209]
<< Scratch dirt resistance evaluation >>
Before printing, use a HEIDON tester to change the load on the non-image area of the printing plate material sample to make scratch marks, and to determine which load has not become dirty at the time of the 100th printing from the start of printing. evaluated. A 0.3 mmφ sapphire needle was used as a stylus. The symbols in the table indicate the following evaluation results.
[0210]
◎: 150 g or more
：: 100 g or more and less than 150 g
Δ: 50 g or more and less than 100 g
×: less than 50 g
《Evaluation of dimensional stability》
Before printing, scratches having a width of 50 μm were made at two places 50 cm apart from the plate surface. It was measured how much the distance between the two flaws changed between the printing paper after printing 100 sheets and the printing paper after printing 3000 sheets. The smaller the dimensional change (μm), the better.
[0211]
《Evaluation of printing durability》
The number of printed sheets in which half or more of the 3% halftone dot image is missing was obtained (printing was performed up to 50,000 sheets). The higher the number of prints, the better.
[0212]
Table 4 shows the results obtained as described above.
[0213]
[Table 4]

[0214]
From Table 4, it is clear that the printing plate sample of the present invention has better ink inking properties, scratch stain resistance, dimensional properties, and excellent printing durability compared to the comparative samples. .
[0215]
Example 2
<< Preparation of printing plate material 201 >>
After the image forming functional layer was applied in the same manner as the printing plate material 104 prepared in Example 1, the following overcoat layer was further dried on the image forming functional layer using a wire bar at a dry weight of 0.4 g / m.²And dried at 50 ° C. for 3 minutes. Further, on the opposite side of the image forming functional layer, the following back layer was dried with a wire bar to a drying amount of 1.5 g / m 2.²And dried at 50 ° C. for 20 minutes to produce a printing plate material 201. Further, a seasoning treatment was performed at 50 ° C. for 24 hours, and then the humidity was controlled at 23 ° C. and a relative humidity of 20% for 24 hours.
[0216]

When the surface roughness of the surface of the back layer was measured, the Ra value was 0.9 μm.
[0219]
Evaluation was performed in the same manner as in Example 1. In the evaluation of the printing durability in Example 2, the number of printed sheets on which the solid portion was blurred was obtained (printing was performed up to 50,000 sheets).
[0218]
Table 5 shows the results obtained as described above.
[0219]
[Table 5]

[0220]
From Table 5, it can be seen that the printing plate material 201 of the present invention provided with the overcoat layer has good ink inking property and scratch stain resistance, excellent dimensional change, and excellent printing durability (so that the solid portion has no blurring). Clearly).
[0221]
Example 3
The printing plate 104 in Example 1 was similarly exposed, and development after exposure was performed using the developing ink at each of the following timings, and the state of image formation was evaluated using a loupe. Table 6 shows the results. Thus, it can be seen that the image intensity is stabilized by providing some drying process after the exposure.
[0222]
[Table 6]

[0223]
【The invention's effect】
In a simple processless printing plate used for CTP, printing performance such as printing durability, stain recovery, scratch resistance, and dimensional stability during printing could be improved by the technology of the present invention.

Claims (10)

Image formation of at least one layer containing a water-soluble resin on one surface of a plastic film support having an average thickness of the support in the range of 110 μm to 500 μm and a thickness distribution of the support of 10% or less. A printing plate material comprising a functional layer and at least one hydrophilic layer between the support and the image forming functional layer. The printing plate material according to claim 1, wherein at least one of the hydrophilic layers has a porous structure. The printing plate material according to claim 1, wherein the image forming functional layer is a layer capable of forming an image by heat, and one of the layers on the support contains a photothermal conversion material. . The printing plate material according to any one of claims 1 to 3, wherein at least a part of the water-soluble resin is crosslinked with a crosslinking agent capable of thermally crosslinking. The printing plate material according to any one of claims 1 to 4, wherein the image forming functional layer contains heat fusible fine particles or heat fusible fine particles. The printing plate material according to any one of claims 1 to 5, wherein at least one surface of the support has at least one layer containing a polyvinylidene chloride resin. The printing plate material according to any one of claims 1 to 6, wherein the moisture content of the support is 0.5% by mass or less. The printing plate material according to any one of claims 1 to 7, wherein the support has at least one constituent layer on the side opposite to the image forming functional layer. A printing method comprising: after forming an image on the printing plate material according to claim 1 using a thermal head or a thermal laser, removing a non-image portion of the image forming functional layer on a printing press. Method. 9. A printing method for performing printing after forming an image of the printing plate material according to any one of claims 1 to 8 using a thermal head or a thermal laser, wherein the printing plate material surface on a printing machine after image formation. A step of drying the surface of the printing plate material until the surface of the printing plate material contacts the water supply roller or the ink supply roller.