JP2005153908A - Lamination package of lithographic printing form - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package of a number of thermal positive type lithographic printing forms, which prevents a film omission on an image part and a spotty film residue on a non-image part, which are caused by the transportation of the package. <P>SOLUTION: The lithographic printing form is composed of a support, a recording underlayer containing a resin that is insoluble in water but soluble in an alkaline aqueous solution, and a recording upper layer, which contains a resin insoluble in water but soluble in an alkaline aqueous solution, and a development inhibitor and becomes more soluble in an alkaline aqueous solution when exposed. The underlayer and the upper layer are overlaid upon the support sequentially, and at least either of the underlayer and upper layer contains a infrared absorbent. At least 200 sheets of the lithographic printing forms are laminated to form a lamination bundle, which is bound into a package, which is then fixed to a carrier member as a lamination package of the lithographic printing form. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminated package of lithographic printing plate precursors. Specifically, the present invention relates to a laminated package of a thermal positive planographic printing plate precursor.

A lithographic printing plate precursor such as a photosensitive printing plate or a heat-sensitive printing plate is usually laminated and packed into a bundle of lithographic printing plate precursors of a predetermined number of forms in various forms depending on the size and type of the lithographic printing plate precursor. Are being transported. For example, in the case of a small number of sheets, a slip sheet is put for each original plate and packed in a cardboard case in units of 20 to 50 original plates. Further, in the case of a large number of sheets, a stacked bundle in which a large number of planographic printing plate precursors are stacked is stacked and fixed on a transport member (carrier member) and packed. A bolt, a belt, a shrink film, or the like is used as a means for fixing the laminated bundle of the planographic printing plate precursor to the carrier member. (For example, see Patent Documents 1 to 4.)
However, for a computer-to-plate (CTP) system, in the case of a thermal positive type lithographic printing plate precursor using an infrared laser, which has recently been popularized, plate making (exposure) after transporting in the above-described packing form , Development), a film with a circular shape with a diameter of 1 mm or less (white spots) is generated in the image area, or a pot-like residual film is formed in the non-image area when developed with low energy exposure. There was a problem that it was easy to.
JP-A-3-73946 JP 2000-118533 A JP 2001-146283 A JP 2002-145316 A

  An object of the present invention is to solve the above-mentioned problems, and to provide a laminated package of a thermal positive type lithographic printing plate precursor that does not cause film loss in an image area and non-image-like residual film due to transportation. is there.

As a result of extensive research, the present inventors used a thermal positive planographic printing plate precursor having an image recording layer having a specific configuration, and bundled a stack of a large number (200 or more) of this planographic printing plate precursor. The present inventors have found that the above object can be achieved by a stacked package packaged and stacked and fixed on a carrier member, and the present invention has been completed.
That is, the present invention is as follows.
The support contains a recording layer lower layer containing a resin that is water-insoluble and soluble in an alkaline aqueous solution, a resin that is water-insoluble and soluble in an alkaline aqueous solution, and a development inhibitor, and is dissolved in the alkaline aqueous solution by exposure. A recording layer upper layer having increased properties in this order, and at least one lithographic printing plate precursor containing an infrared absorber is laminated on at least one of the upper and lower recording layers to form a laminated bundle, and the laminated bundle is bound A laminated package of lithographic printing plate precursors obtained by packing and fixing the bound package on a carrier member.

  The working mechanism of the above-described invention in which the above object has been achieved is not clear, but when a package body in which a large number of lithographic printing plate precursors are stacked and packed is fixed on a carrier member, it is localized due to vertical vibration during transportation. This is considered to be attributable to the fact that the lithographic printing plate precursor having a multi-layered recording layer is more difficult to form a residual film because the developability is improved.

  According to the present invention, it is possible to provide a multi-layer package of thermal positive type lithographic printing plate precursors that does not cause image portion film loss and non-image portion pot-like residual film due to transportation.

〔Packing method〕
The laminated package of the present invention is obtained by fixing a package of a laminated body (laminated bundle) obtained by laminating 200 or more lithographic printing plate precursors alternately with or without interleaving paper on a carrier member. Examples of fixing methods include fixing with bolts, fixing with a belt, fixing with a shrink film film, and the like. The laminated body may be stacked sideways with respect to the carrier member as shown in FIG. 3, or may be stacked vertically as shown in FIG. Regarding these packing methods, for example, JP-A-3-73946, JP-A-2000-118533, JP-A-2002-145316, and JP-A-2001-146283 can be referred to. The effect of the present invention can be exhibited if the number of lithographic printing plate precursors is 200 or more. In the present invention, the number of lithographic printing plate precursors stacked is not particularly limited as long as it is 200 or more, but is preferably less than 4,000 from the viewpoint of transportability. More preferably, it is in the range of 200 to 3,000, and particularly preferably in the range of 250 to 2,000.
Hereinafter, the packaging method of the laminated package of the present invention will be described in detail with specific examples.

[Specific examples of packing methods]
(First embodiment)
First, based on FIG. 1, the laminated package of the lithographic printing plate precursor according to the first embodiment of the present invention will be described. In the package 10 shown in FIG. 1, a thick plate-like stacking member 12 is arranged at the lower end, and a predetermined number of planographic printing plate precursors 14 are laminated on the stacking member 12 in the thickness direction. A stacked bundle (hereinafter also simply referred to as “bundle”) 16 of the lithographic printing plate precursors that have been made is stacked. A slip sheet may be inserted on the lithographic printing plate precursor.

  The stacking member 12 has a cross-sectional shape along the surface direction substantially the same as the surface shape of the planographic printing plate precursor 14. In addition, the stacking member 12 is configured, for example, by laminating a plurality of cardboards along the thickness direction and bonding the cardboards with an adhesive or the like. At this time, the plurality of cardboards constituting the stacking member 12 are stacked such that the wave directions are perpendicular to each other between adjacent cardboards along the thickness direction. Thereby, the stacking member 12 is prevented from being weakened by a bending stress in a specific direction.

The type of cardboard used as the material for the stacking member 12 is appropriately selected according to the following conditions. First, the corrugated cardboard flutes are preferably BA flute, AB flute, A flute, B flute and C flute. Further, when the grades of the front liner and the back liner of the corrugated cardboard are listed in a preferable order, they are AA class, A class, B class, and C class, and the basis weight of the front liner and the back liner is 160 (g / m ² ) or more. 440 (g / m ² ) or less is preferable. In addition, the types of corrugated shin are listed in the preferred order: reinforced medium shin, A grade, B grade, and C grade. The basis weight of the shin is 100 (g / m ² ) or more and 280 (g / m ^2). The following are preferred.

The stacking member 12 can be made of a honeycomb structure material or cardboard instead of the corrugated cardboard. When the honeycomb structure material is used, the front liner, the back liner, and the middle tint similar to the corrugated cardboard described above are used. It is preferable that when using cardboard, the basis weight is preferably 200 (g / m ² ) or more and 2000 (g / m ² ) or less. Furthermore, such a stacking member 12 may be configured by laminating plate materials made of wood, resin, or the like, or may be integrally formed using wood, resin, or the like as a material.

  The bundle 16 stacked on the stacking member 12 includes about 200 to 4000 planographic printing plate precursors 14 and has a weight of several tens to several hundred kg. Two bundle bands 18 made of resin or the like are wound around the bundle 16 and the stacking member 12 so as to be in a tension state and bound. Thereby, the relative movement (shift) between the planographic printing plate precursors 14 constituting the bundle 16 and the movement of the bundle 16 relative to the stacking member 12 are restricted. For this reason, the stacking member 12 needs to have sufficient strength so that deformation such as compression does not occur even when it receives the weight of the bundle 16 and the tension from the binding band 18.

  Next, a method for packaging the package 10 loaded on the carrier pallet 24 of the present embodiment will be described. When the packaging body 10 is stacked in a flat state on the top plate 28 of the carrier pallet 24, first, as shown in FIG. 2A, the belt-shaped interior paper 34 is brought into close contact with the outer surface of the packaging body 10. Wrap. The interior paper 34 is cut so that the dimension along the short direction is longer than the thickness of the package 10 and the dimension along the longitudinal direction is longer than the outer peripheral length of the package 10. The interior paper 34 wound around the outer surface of the package 10 is formed into a tubular shape as a whole by affixing a tape 36A such as an adhesive tape at the joint. (See FIG. 2 (B).)

Next, the lower end portion of the interior paper 34 is bonded to the outer surface of the stacking member 12 by the tape 36B over the entire circumference. Thereafter, the upper end portion of the interior paper 34 is folded inward along the upper edge portion of the packaging body 10, and the seam of the interior paper 34 on the packaging body 10 is formed by the tape 36C as shown in FIG. It is pasted together. As a result, the package 10 on the stacking member 12 is packaged by the interior paper 34, and is made moisture-proof and light-shielded by the interior paper 34. In addition, as the interior paper 34 which has light-shielding property and moisture-proof property, the aluminum kraft paper which bonded 6 micrometer aluminum foil to the kraft paper of basic weight 85g / m < ² > with 13 micrometer low density polyethylene is applicable, for example.

  As shown in FIG. 3, the package 10 packaged with the interior paper 34 as described above is wound with a plurality of fixing bands 38 inserted through the insertion holes 32 of the carrier pallet 24 around the upper surface portion. The circumference of the band 38 is drawn until sufficient tension is generated. Thereby, the package 10 is fixed on the carrier pallet 24 by the tension of the fixing band 38. As shown in FIG. 4, even when the sheet pallet 20 is disposed on the lower side of the stacking member 12 in the package 10, the sandwiched portion 22 of the sheet pallet 20 is on the side end surfaces of the stacking member 12 and the bundle 16. It is in a state of being folded upward so as to be in close contact, and after being wrapped by the interior paper 34, it is fixed to the carrier pallet 24 by a fixing band 38.

  In addition, a concave portion is provided on one of the stacking member 12 and the carrier pallet 24 in the packaging body 10, and a convex portion that is inserted into the concave portion when the packaging body 10 is stacked on the carrier pallet 24 is provided on the other side. Thus, the movement of the package 10 on the carrier pallet 24 may be reliably prevented. Further, after the outer side of the package 10 packaged with the interior paper 34 is further covered with an exterior material such as cardboard, the package 10 may be fixed to the carrier pallet 24 by the fixing band 38.

  Next, the effect | action by the packing method in this embodiment is demonstrated. That is, according to the packing method of the lithographic printing plate precursor according to the present embodiment, the binding band 18 is wound around the outer surface of the bundle 16 on the stacking member 12 to restrain the relative movement between the lithographic printing plate precursor 14 and the binding band. The bundle 16 is bound to the stacking member 12 by 18 to make the bundle 16 and the stacking member 12 into the package 10, and then the package 10 is loaded on the carrier pallet 24 and fixed by the fixing band 38. Since the lithographic printing plate precursor 14 constituting the plate 16 can be directly restrained by the binding band 18 and the bundle 16 can be directly bound and fixed to the stacking member 12, an impact from the outside acts on the package 10 during transportation. Even when the package 10 is tilted, the displacement between the planographic printing plate precursors 14 in the package 10, the vertical vibration, and the displacement of the bundle 16 with respect to the stacking member 12 are effective. To be prevented.

  Further, since the bundle 16 on the stacking member 12 is loaded on the carrier pallet 24 in a state of being restrained by the binding band 18, it is not necessary to use an exterior material such as cardboard, a back plate, a contact plate, or the like as in the prior art. In addition, since the deviation between the planographic printing plate precursors 14 on the carrier pallet 24 can be surely prevented, the packaging material and work related to the packaging and packaging for the bundle 16 loaded on the carrier pallet 24 can be simplified. Furthermore, in this embodiment, the package 10 is fixed to the carrier pallet 24 by a plurality of fixing bands 38. However, the packing 10 and the carrier pallet 24 can be formed by a simpler method than the fixed band 38, for example, shrink film packaging. Even if the packaging body 10 is fixed to the carrier pallet 24 by a method such as packaging the packaging body 10 or pasting the packaging body 10 with a tape member such as a gum tape, the deviation between the planographic printing plate precursors 14 during transportation And breakage of the bundle 16 can be prevented.

(Second Embodiment)
FIG. 5 shows another embodiment of the laminated package of the present invention. In the packaging method of the present embodiment, the planographic printing plate precursor 14 is laminated on the stacking member 12 to form a bundle 16, and the bundle 16 and the stacking member 12 are bundled from the binding band 18 to form the package 10. The process is the same as the packaging method in the first embodiment, and the subsequent processes are different from the packaging method in the first embodiment. A slip sheet may be inserted on the lithographic printing plate precursor.

  That is, in the packaging method in the present embodiment, as shown in FIG. 5, the packaging body 10 is stacked in a vertically stacked state on the skid 40 that is a carrier member. Here, the skid 40 is provided with a pallet portion 42 having a substantially rectangular plate shape at a lower end portion thereof, and a plurality of insertion holes 44 penetrate the pallet portion 42 in a side surface portion of the pallet portion 42. It has been drilled. Each insertion hole 44 is an insertion portion for a fork or the like during transportation by a forklift or a handlift.

  An inclined plate 46 is disposed on the pallet portion 42 in the skid 40. The inclined plate 46 has a wedge shape such that the thickness decreases from one end to the other end side along the longitudinal direction of the pallet portion 42. Thereby, the upper surface of the inclined plate 46 becomes an inclined surface inclined downward from one end to the other end side. The skid 40 has a flat plate-like back plate 48 standing on the pallet portion 42 so as to be in contact with the other end of the inclined plate 46. The back plate 48 is inclined 5 to 30 ° (preferably 10 to 15 °) with respect to the vertical direction.

  The package 10 is placed on the inclined plate 46 of the skid 40, and one surface along the thickness direction is abutted against the back plate 48. In this state, a corner contact member 50 having an L-shaped cross section is applied to both corner portions at the upper end portion of the package body 10, and the package body 10 is inclined through the pair of corner contact members 50. The belt is tightened by a tightening belt 52 connected to 46. Thereby, the package 10 is fixed on the skid 40. Further, a fall prevention belt 54 connected to the back plate 48 is wound around both side end surfaces of the package 10 and the surface opposite to the back plate 48. Thereby, the packing for the bundle 16 stacked in a vertically stacked state on the skid 40 is completed.

  Also by the packing method in the second embodiment described above, the same operation and effect as the packing method in the first embodiment can be obtained, and further compared with the first embodiment, the planographic printing plate precursor 14 When the size is large, there is an advantage that the floor space for storing the lithographic printing plate precursor 14 in the bundle 16 can be suppressed.

  In the present invention, the carrier member for loading and fixing the laminated bundle of lithographic printing plate precursors is not particularly limited, and for example, those suitable for use in forklifts and handlifts used during normal transportation can be used. Specific examples include wooden pallets and metal pallets such as iron.

Next, the planographic printing plate precursor used in the package of the present invention will be described in detail.
[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the present invention comprises, on a support, a recording layer lower layer containing a resin that is water-insoluble and soluble in an alkaline aqueous solution, a resin that is water-insoluble and soluble in an alkaline aqueous solution, and a development inhibitor. And an upper layer of the recording layer whose solubility in an alkaline aqueous solution increases by exposure in this order, and an infrared absorber is contained in at least one of the lower layer and the upper layer of the recording layer. (In the following, a resin that is insoluble in water and soluble in an alkaline aqueous solution may be simply referred to as an alkali-soluble resin.)
Thermal positive lithographic printing plate precursors having such a multilayered recording layer are described, for example, in JP-A Nos. 11-218914, 2002-229213, and 2002-251003. .
Hereinafter, the elements constituting the planographic printing plate precursor according to the invention will be described in detail.

[Configuration of recording layer lower layer]
The recording layer lower layer (hereinafter sometimes referred to simply as the lower layer) of the lithographic printing plate precursor used in the present invention must be a water-insoluble resin that is soluble in an alkaline aqueous solution. Further, in the lower layer component according to the present invention, an infrared absorber and other additives can be used as necessary. Examples of other additives include development accelerators, surfactants, printout / coloring agents, plasticizers, and WAX agents. The details of the type and content of the infrared absorber and other additives are the same as those described as components of the upper layer described later. From the viewpoint of improving the pot-like residual film generated by low-energy exposure of the non-image area, the dissolution rate in the lower layer developer is preferably greater than 30 nm / sec.

(Resin that is water-insoluble and soluble in alkaline aqueous solution)
The water-insoluble resin that can be used in the lower layer in the present invention and is soluble in an alkaline aqueous solution is not particularly limited as long as it has a property of dissolving when contacted with an alkaline developer, but the main chain in the polymer and It is preferably a homopolymer containing an acidic group in the side chain, a copolymer thereof, or a mixture thereof.
As an alkali-soluble resin having such an acidic group, in particular, any functional group of (1) phenolic hydroxyl group, (2) sulfonamide group, (3) active imide group, or (4) carboxyl group is a molecule. Examples thereof include a polymer compound contained therein. Examples of the polymer include acrylic, novolac, polyurethane, polyurea, polyamide, and polyester.
Examples of the polymer compound include the following, but the present invention is not limited thereto.

  (1) Examples of the polymer compound having a phenolic hydroxyl group include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p Any of-or m- / p-mixing may be used. Examples include novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins. In addition to this, a polymer compound having a phenolic hydroxyl group in the side chain is preferably used as the polymer compound having a phenolic hydroxyl group. As a polymer compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular compound having at least one phenolic hydroxyl group and at least one polymerizable unsaturated bond is homopolymerized, or other polymerization is performed on the monomer. And a high molecular compound obtained by copolymerizing a functional monomer.

  Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenolic hydroxyl group. Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N- (3- Hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) methacrylamide, o-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, o-hydroxyphenyl methacrylate, m-hydroxyphenyl methacrylate, p-hydroxy Phenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl) Preferable are til acrylate, 2- (4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate, 2- (4-hydroxyphenyl) ethyl methacrylate, etc. Can be used. Such resins having a phenolic hydroxyl group may be used in combination of two or more. Furthermore, as described in US Pat. No. 4,123,279, phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, These copolymers may be used in combination.

(2) Examples of the alkali-soluble resin having a sulfonamide group include polymer compounds obtained by homopolymerizing a polymerizable monomer having a sulfonamide group or copolymerizing the monomer with another polymerizable monomer. The polymerizable monomer having a sulfonamide group includes one or more sulfonamide groups —NH—SO ₂ — in which at least one hydrogen atom is bonded on a nitrogen atom and one or more polymerizable unsaturated bonds in one molecule. And a polymerizable monomer comprising a low molecular weight compound. Among these, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group, and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group is preferable.

(3) The alkali-soluble resin having an active imide group is a homopolymerization of a polymerizable monomer composed of a low molecular compound having at least one unsaturated bond polymerizable with an active imide group in one molecule, or other than this monomer. And a polymer compound obtained by copolymerizing the polymerizable monomer.
As such a compound, specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.

  (4) As the alkali-soluble resin having a carboxyl group, for example, a polymerizable monomer composed of a low molecular compound having at least one carboxyl group and polymerizable unsaturated group in the molecule is homopolymerized or other than the monomer. And a polymer compound obtained by copolymerizing the polymerizable monomer. Specific examples of the polymerizable monomer having a carboxyl group include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and itaconic acid. Also, monoesters of hydroxyl groups of acrylates or methacrylates having hydroxyl groups in the side chains (for example, 2-hydroxyethylethyl acrylate or methacrylate) and dibasic acids (for example, succinic acid, glutaric acid, phthalic acid, etc.) The unsaturated carboxylic acid which is is also preferable.

  The alkali-soluble resin according to the present invention may be a polymer compound obtained by polymerizing two or more of the polymerizable monomers having a phenolic hydroxyl group, a sulfonamide group, an active imide group or a carboxyl group. The copolymerization ratio of the above polymerizable monomers and the combination of the polymerizable monomers are not limited, but the polymerizable monomer having a sulfonamide group and / or the active imide group is particularly polymerizable in the polymerizable monomer having a phenolic hydroxyl group. When the monomers are copolymerized, the blending polymerization ratio of these components is preferably in the range of 50:50 to 5:95, particularly preferably in the range of 40:60 to 10:90.

Furthermore, as the alkali-soluble resin according to the present invention, in addition to one or two or more polymerizable monomers selected from polymerizable monomers having the phenolic hydroxyl group, sulfonamide group, active imide group or carboxyl group, A polymer compound obtained by copolymerizing another polymerizable monomer is preferable. As a copolymerization ratio in this case, it is preferable that the monomer which provides alkali solubility is contained 10 mol% or more, and what contains 20 mol% or more is more preferable.
Examples of other polymerizable monomers that can be used here include the compounds listed in the following (m1) to (m11), but the present invention is not limited thereto.

(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide and Np-cyanophenylmethacrylamide.

(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.

When the alkali-soluble resin according to the present invention is a homopolymer or copolymer of a polymerizable monomer having the phenolic hydroxyl group, sulfonamide group, active imide group or carboxyl group, the weight average molecular weight is 2,000 or more, several Those having an average molecular weight of 500 or more are preferred. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10. .
When the alkali-soluble resin according to the present invention is a phenol formaldehyde resin or a cresol aldehyde resin, the weight average molecular weight is 500 to 20,000, and the number average molecular weight is preferably 200 to 10,000. .

  In the present invention, two or more kinds of alkali-soluble resins having different dissolution rates in an alkaline aqueous solution may be mixed and used, and the mixing ratio in that case is arbitrary.

  The content of the alkali-soluble resin relative to the total solid content of the lower layer according to the present invention is used in an addition amount of 50 to 98% by mass. Within this range, good sensitivity and durability of the recording layer can be obtained.

[Configuration of the upper recording layer]
The recording layer upper layer according to the present invention (hereinafter sometimes referred to simply as the upper layer) contains an alkali-soluble resin and a development inhibitor, and is characterized in that the solubility in an alkaline aqueous solution increases upon exposure. Hereinafter, each component of the upper layer according to the present invention will be described.

(Alkali-soluble resin)
The alkali-soluble resin usable in the upper layer in the present invention is not limited as long as it is an alkali-soluble resin described in the lower layer. However, strong hydrogen bonding occurs in the unexposed area, and some hydrogen bonds are easily formed in the exposed area. From the viewpoint of being released, the resin having a phenolic hydroxyl group is more preferable, and among the resins having a phenolic hydroxyl group, a novolak resin is particularly preferable.
Further, in the upper layer of the present invention, two or more kinds of alkali-soluble resins having different dissolution rates with respect to the alkaline aqueous solution may be mixed and used, and the mixing ratio in that case is arbitrary. In addition, the alkali-soluble resin suitable for mixing with the resin having a phenolic hydroxyl group is preferably an acrylic resin, more preferably a sulfoamide group or the like because of its low compatibility with a resin having a phenolic hydroxyl group. An acrylic resin having a carboxyl group.

  Content of alkali-soluble resin with respect to the total solid content of the upper layer which concerns on this invention is used by the addition amount of 50-98 mass% collectively. Within this range, good sensitivity and durability of the recording layer can be obtained.

(Development inhibitor)
The upper layer according to the present invention contains a development inhibitor for the purpose of enhancing its inhibition (dissolution inhibiting ability).
The development inhibitor according to the present invention forms an interaction with the alkali-soluble resin, substantially lowers the solubility of the alkali-soluble resin in a developer in an unexposed area, and The interaction is not particularly limited as long as it can weaken the interaction and become soluble in the developer, but quaternary ammonium salts, polyethylene glycol compounds and the like are particularly preferably used. Among infrared absorbers and image colorants described later, there are compounds that function as a development inhibitor, and these are also preferred.

The quaternary ammonium salt is not particularly limited, and examples thereof include tetraalkylammonium salt, trialkylarylammonium salt, dialkyldiarylammonium salt, alkyltriarylammonium salt, tetraarylammonium salt, cyclic ammonium salt, and bicyclic ammonium salt. It is done.
Specifically, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide, tetraoctylammonium bromide, tetralaurylammonium bromide, tetraphenylammonium bromide, tetranaphthylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide , Tetrastearyl ammonium bromide, lauryl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, behenyl trimethyl ammonium bromide, lauryl triethyl ammonium bromide, phenyl trimethyl ammonium bromide, 3-trifluoromethylphenyl trimethyl ammonium bromide, benzyl trimethyl ammonium bromide De, dibenzyl dimethyl ammonium bromide, distearyl dimethyl ammonium bromide, tristearyl methyl ammonium bromide, benzyl triethyl ammonium bromide, hydroxyphenyl trimethyl ammonium bromide, N- methyl pyridinium bromide, and the like. In particular, quaternary ammonium salts described in JP2003-107688A and JP2003-167332A are preferable.

  The addition amount of the quaternary ammonium salt is preferably 0.1 to 50% by mass, and more preferably 1 to 30% by mass with respect to the total solid content of the upper layer. Within this range, a good development suppressing effect can be obtained without adversely affecting the film forming property of the alkali-soluble resin.

Moreover, it does not specifically limit as a polyethyleneglycol type compound, The thing of the structure represented by following General formula (1) is mentioned.
^{R 1 - {- O- (R} 3 -O-) m-R 2} n (1)
In the general formula (1), R ¹ represents a polyhydric alcohol residue or a polyhydric phenol residue, R ² represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms which may have a substituent, An alkenyl group, an alkynyl group, an alkylyl group, an aryl group or an aryloyl group is represented. R ³ represents an alkylene residue which may have a substituent, m represents an integer of 10 or more on average, and n represents an integer of 1 to 4.

  Examples of the polyethylene glycol compound represented by the general formula (1) include polyethylene glycols, polypropylene glycols, polyethylene glycol alkyl ethers, polypropylene glycol alkyl ethers, polyethylene glycol aryl ethers, polypropylene glycol aryl ethers, Polyethylene glycol alkyl aryl ethers, polypropylene glycol alkyl aryl ethers, polyethylene glycol glycerol esters, polypropylene glycol glycerol esters, polyethylene sorbitol esters, polypropylene glycol sorbitol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyethylene glycol Lumpur ethylenediamines, polypropylene glycolated ethylenediamines, polyethylene glycolated diethylenetriamine, and polypropylene glycol diethylenetriamines.

  Further specific examples include polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 10000, polyethylene glycol 20000, polyethylene glycol 5000, polyethylene glycol 100000, polyethylene glycol 200000, polyethylene glycol 500000, polypropylene glycol 1500, polypropylene glycol. 3000, polypropylene glycol 4000, polyethylene glycol methyl ether, polyethylene glycol ethyl ether, polyethylene glycol phenyl ether, polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol diphenyl ether Ter, polyethylene glycol lauryl ether, polyethylene glycol dilauryl ether, polyethylene glycol nonyl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol distearyl ether, polyethylene glycol behenyl ether, polyethylene glycol dibehenyl ether, polypropylene glycol methyl ether, Polypropylene glycol ethyl ether, polypropylene glycol phenyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diethyl ether, polypropylene glycol diphenyl ether, polypropylene glycol lauryl ether, polypropylene glycol dilauryl ether , Polypropylene glycol nonyl ether, polyethylene glycol acetyl ester, polyethylene glycol diacetyl ester, polyethylene glycol benzoic acid ester, polyethylene glycol lauryl ester, polyethylene glycol dilauryl ester, polyethylene glycol nonyl acid ester, polyethylene glycol cetyl acid ester, polyethylene glycol stearoyl ester, Polyethylene glycol distearoyl ester, polyethylene glycol behenate ester, polyethylene glycol dibehenate ester, polypropylene glycol acetyl ester, polypropylene glycol diacetyl ester, polypropylene glycol benzoate ester, polypropylene glycol dibenzoate ester Polypropylene glycol laurate, polypropylene glycol dilaurate, polypropylene glycol nonyl ester, polyethylene glycol glycerol ether, polypropylene glycol glycerol ether, polyethylene glycol sorbitol ether, polypropylene glycol sorbitol ether, polyethylene glycolated ethylenediamine, polypropylene glycolated ethylenediamine Polyethylene glycolated diethylenetriamine, polypropylene glycolated diethylenetriamine, and polyethylene glycolated pentamethylenehexamine.

  The addition amount of the polyethylene glycol compound is preferably 0.1 to 50% by mass, and more preferably 1 to 30% by mass with respect to the total solid content of the upper layer.

In addition, when such measures are taken to increase the inhibition (dissolution suppression ability), the sensitivity decreases. In this case, it is effective to add a lactone compound to the upper layer to suppress the sensitivity decrease. is there. The lactone compound reacts with the lactone compound when the developer penetrates into the exposed area, that is, the recording layer in the area where the inhibition is released. It is considered that the sensitivity is improved by promoting the dissolution of the recording layer in the partial area. In the unexposed area, this lactone compound forms an interaction with a polar group in the alkali-soluble resin, for example, a hydroxyl group in the novolak resin, and is stable in the film together with a bulky structure having a ring. Therefore, even when an alkaline developer is contacted with the surface of the unexposed area, the rapid opening of the lactone ring during the development process is suppressed, so that the development resistance of the region is reduced. Absent.
This interaction is released more easily by the exposure or heating than the inhibitory action by the dissolution inhibitor, so that the ring-opening reaction of the lactone compound in the exposed part is performed rapidly.
Although it does not specifically limit as such a lactone compound, As a specific example, the compound as described in Paragraph Nos. [0023]-[0024] of Unexamined-Japanese-Patent No. 2002-351066 is mentioned.

The addition amount of the lactone compound is preferably 0.1 to 50% by mass, and more preferably 1 to 30% by mass with respect to the total solid content of the upper layer.
Any one lactone compound may be used in the present invention, or two or more lactone compounds may be used in combination.

  In addition, a substance that is thermally decomposable and substantially reduces the solubility of the alkali-soluble resin, such as an onium salt, an o-quinonediazide compound, an aromatic sulfone compound, and an aromatic sulfonic acid ester compound. Is preferably used from the viewpoint of improving the inhibition of the image portion in the developer.

  Examples of the onium salt used in the present invention include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and the like. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Balet al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055, 4,069,056, and JP-A-3-140140. Ammonium salts described in the specification, D.I. C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056,

  J. et al. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, US Pat. Nos. 5,041,358, 4,491,628, JP-A-2-150848 and JP-A-2-296514. Iodonium salts, J.M. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. , 14, 279 (1985),

  J. et al. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patents 370,693, 233,567, 297,443, 297,442, U.S. Pat. Nos. 4,933,377, 3,902,114 No. 4,491,628, No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626, No. 3,604 The sulfonium salt described in No. 580 and No. 3,604,581,

J. et al. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988).
Of these onium salts, a diazonium salt is particularly preferable. Particularly suitable diazonium salts include those described in JP-A-5-158230.

  The counter ion of the onium salt includes tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfone Examples include acid, 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid, and paratoluenesulfonic acid. Of these, particularly preferred are alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid.

Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and compounds having various structures can be used. That is, o-quinonediazide assists the solubility of the upper layer by both the effect of losing the inhibition as a development inhibitor due to thermal decomposition and the change of o-quinonediazide itself into an alkali-soluble substance.
Examples of such o-quinonediazide compounds include J. Org. Although the compounds described in pages 339-352 of “Light-sensitive systems” by John Coley (John Wiley & Sons. Inc.) can be used, especially o-quinonediazides reacted with various aromatic polyhydroxy compounds or aromatic amino compounds. The sulfonic acid esters or sulfonic acid amides are preferred. Further, benzoquinone (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2-diazidesulfonic acid chloride or naphthoquinone- (1,2) -diazide-5 described in US Pat. Nos. 3,046,120 and 3,188,210. Esters of sulfonic acid chloride and phenol-formaldehyde resin are also preferably used.

  Further, an ester of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin Similarly, the esters are also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication Nos. 41-11222, 45-9610, 49-17474, U.S. Pat. Nos. 2,797,213, 3,454,400, 3,544,323, 3,573,917, 3,674,495, 3,785,825, British Patents 1,227,602, 1,251,345, 1,267, No. 005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

The addition amount of the o-quinonediazide compound is preferably in the range of 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 30% by mass with respect to the total solid content of the upper layer. These compounds can be used alone, but may be used as a mixture of several kinds.
Moreover, you may include the alkali-soluble resin by which at least one part of Unexamined-Japanese-Patent No. 11-288089 was esterified.

Further, for the purpose of enhancing the inhibition of the scratch on the surface as well as the inhibition of the recording layer surface, the perfluoroalkyl having 3 to 20 carbon atoms in the molecule as described in JP-A-2000-187318. It is preferable to use a polymer having a polymerization component of a (meth) acrylate monomer having 2 or 3 groups.
As addition amount, 0.1-10 mass% is preferable with respect to upper layer total solid, More preferably, it is 0.5-5 mass%.

(Infrared absorber)
In the lithographic printing plate precursor according to the invention, it is necessary to add an infrared absorber to at least one of the lower layer and the upper layer of the recording layer. Such an infrared absorber is not particularly limited as long as it is a dye that absorbs infrared light and generates heat, and various dyes known as infrared absorbers can be used.

  As the infrared absorber according to the present invention, commercially available dyes and publicly known dyes described in literature (for example, “Dye Handbook” edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. In the present invention, among these dyes, those that absorb infrared light or near infrared light are particularly preferred because they are suitable for use in lasers that emit infrared light or near infrared light.

  Examples of such dyes that absorb infrared light or near infrared light include those disclosed in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-2001-133969, and the like. Cyanine dyes described in JP-A-58-173696, methine dyes described in JP-A-58-181590, JP-A-58-194595, etc., JP-A-58-112793 Naphthoquinone dyes described in JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. And squarylium dyes described in JP-A No. 58-112792, and cyanine dyes described in British Patent No. 434,875.

Further, near-infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used as dyes, and substituted arylbenzoates described in US Pat. No. 3,881,924 are also preferred. (Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645, JP-A-58-181051, 58-220143, 59-41363, 59-84248, 59 -84249, 59-146063, 59-146061, pyrium compounds, cyanine dyes described in JP-A-59-216146, U.S. Pat. No. 4,283,475. The pentamethine thiopyrylium salt described in Japanese Patent Publication No. 5-13514, the Japanese Patent Publication No. 5-19702, and the like The goods, Eporin Co. Epolight III-178, Epolight III-130, Epolight III-125 and the like are particularly preferably used.
Another particularly preferable example of the dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

These infrared absorbers are preferably added to the upper layer of the recording layer or in the vicinity thereof from the viewpoint of sensitivity. In particular, when a substance having a dissolution inhibiting ability such as a cyanine dye is added together with the alkali-soluble resin, at the same time as increasing the sensitivity, the unexposed area can be made resistant to alkali. These infrared absorbers may be added to the lower layer or both the upper and lower layers. By adding it to the lower layer, it is possible to further increase the sensitivity. When an infrared absorber is added to both the upper layer and the lower layer, the same compound may be used, or different compounds may be used.
These infrared absorbers may be added to the same layer as the recording layer, or another layer may be provided and added thereto. In the case of a separate layer, it is desirable to add it to a layer adjacent to the recording layer.
Furthermore, when the infrared absorber is a compound having dissolution inhibiting ability, the infrared absorber can be used not only as a photothermal conversion function but also as the development inhibitor by being contained in the same layer as the alkali-soluble resin. It is preferable because it functions.

  As addition amount of an infrared absorber, when adding to an upper layer, 0.01-30 mass% is preferable with respect to upper layer total solid, More preferably, it is 0.1-20 mass%, Most preferably, it is 1.0-10. % By mass.

  Moreover, when adding to a lower layer, 0-20 mass% is preferable with respect to a lower layer total solid, More preferably, it is 0-10 mass%, Most preferably, it is 0-5 mass%. When an infrared absorber is added to the lower layer, the solubility of the lower layer is reduced when an infrared absorber having dissolution inhibiting ability is used. On the other hand, the infrared absorber generates heat during infrared laser exposure, and the lower layer is soluble by heat. Since improvement can be expected, the compound to be added and the addition amount should be selected in consideration of these balances. In the region of 0.2 to 0.3 μm in the vicinity of the support, it is difficult to obtain the effect of improving the solubility due to heat, for example, the heat generated during exposure diffuses to the support. In some cases, the decrease in sensitivity may cause a decrease in sensitivity. Therefore, it is preferable to make the addition amount such that the dissolution rate in the lower layer developer (25 ° C. to 30 ° C.) exceeds 30 nm / sec even within the range of the addition amount shown above.

(Other additives)
In forming the lower layer and the upper layer of the recording layer, various additives can be added as necessary, in addition to the above essential components, as long as the effects of the present invention are not impaired. The additives listed below may be added only to the lower layer, may be added only to the upper layer, or may be added to both layers.

<Development accelerator>
For the purpose of improving sensitivity, acid anhydrides, phenols, and organic acids may be added to the upper layer and / or the lower layer, which are recording layers according to the present invention.
As the acid anhydrides, cyclic acid anhydrides are preferable. Specific examples of the cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride described in US Pat. No. 4,115,128. Acid, 3,6-endooxy-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of the acyclic acid anhydride include acetic anhydride.

  Examples of phenols include bisphenol A, 2,2′-bishydroxyphenylsulfone, 4,4′-bishydroxyphenylsulfone, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2 , 3,4-Trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ′, 4 ″ -trihydroxytriphenylmethane, 4,4 ′, 3 ″, 4 ″ -tetrahydroxy-3,5,3 ′, 5 Examples include '-tetramethyltriphenylmethane.

Examples of organic acids include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphoric esters and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid , P-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like.
The proportion of the acid anhydride, phenols and organic acids in the total solid content of the lower or upper layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0. 1 to 10% by mass.

<Surfactant>
In order to improve the coating property and to expand the stability of the processing with respect to the developing conditions, the upper layer and / or the lower layer, which are the recording layers according to the present invention, are disclosed in JP-A-62-251740 and JP-A-3-3. Nonionic surfactants as described in Japanese Patent No. 208514, amphoteric surfactants as described in Japanese Patent Application Laid-Open Nos. 59-121044 and 4-13149, and described in EP950517 Siloxane compounds such as those described in JP-A-62-2170950, JP-A-11-288093, and JP-A-2003-57820 can be added. it can.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like. Specific examples of amphoteric activators include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N-betaine. Type (for example, trade name “Amorgen K” manufactured by Daiichi Kogyo Co., Ltd.).

As the siloxane compound, a block copolymer of dimethylsiloxane and polyalkylene oxide is preferable. Specific examples include DBE-224, DBE-621, DBE-712, DBP-732, DBP-534, manufactured by Chisso Corporation. And polyalkylene oxide-modified silicones such as Tego Glide 100 manufactured by Tego, Germany.
The proportion of the nonionic surfactant and amphoteric surfactant in the total solid content of the lower layer or upper layer is preferably 0.01 to 15% by mass, more preferably 0.1 to 5.0% by mass, and still more preferably. 0.5 to 2.0 mass%.

<Bake-out agent / colorant>
To the upper layer and / or the lower layer, which is the recording layer according to the present invention, a print-out agent for obtaining a visible image immediately after heating by exposure, or a dye or pigment as an image colorant can be added.
A representative example of the printing-out agent is a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halides and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, No. -36223, 54-74728, 60-3626, 61-143748, 61-151644 and 63-58440, and trihalomethyl compounds and salt-forming organic dyes Can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear printout images.

As the image colorant, other dyes can be used in addition to the aforementioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (above Orient Chemical Industry) Co., Ltd.), Victoria Pure Blue, Crystal Violet Lactone, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. it can. The dyes described in JP-A-62-293247 are particularly preferred.
These dyes can be added in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content of the lower layer or upper layer.

<Plasticizer>
A plasticizer may be added to the upper layer and / or the lower layer, which is the recording layer according to the present invention, in order to impart flexibility and the like of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.
These plasticizers can be added in a proportion of 0.5 to 10% by mass, preferably 1.0 to 5% by mass, based on the total solid content of the lower layer or upper layer.

<WAX agent>
In the upper layer according to the present invention, for the purpose of imparting resistance to scratches, a compound that reduces the static friction coefficient of the surface can be added. Specifically, as described in US Pat. No. 6,117,913, Japanese Patent Application Laid-Open No. 2003-149799, Japanese Patent Application Laid-Open No. 2003-302750, or Japanese Patent Application No. 2002-165854, A compound having an ester of a long-chain alkyl carboxylic acid can be exemplified.
The addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass in the upper layer.

[Formation of recording layer]
The recording layer lower layer and the upper layer in the lithographic printing plate precursor according to the invention can be usually formed by dissolving the above components in a solvent and coating them on a suitable support.
Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited. These solvents are used alone or in combination.

In principle, the lower layer and the upper layer are preferably formed by separating two layers. As a method for forming the two layers separately, for example, a method using a difference in solvent solubility between a component contained in the lower layer and a component contained in the upper layer, or after applying the upper layer, a solvent is rapidly used. For example, a method of drying and removing.
Hereinafter, although these methods are explained in full detail, the method of apply | coating two layers separately is not limited to these.

As a method of utilizing the difference in solvent solubility between the component contained in the lower layer and the component contained in the upper layer, a solvent system in which any of the components contained in the lower layer is insoluble is used when the upper layer coating solution is applied. Is. Thereby, even if it carries out 2 layer application | coating, it becomes possible to isolate | separate each layer clearly and to make a coating film.
For example, as the lower layer component, a component insoluble in a solvent such as methyl ethyl ketone or 1-methoxy-2-propanol that dissolves the alkali-soluble resin that is the upper layer component is selected, and the lower layer is applied using a solvent system that dissolves the lower layer component. -It is possible to form two layers by drying and then dissolving the upper layer component mainly composed of alkali-soluble resin with methyl ethyl ketone, 1-methoxy-2-propanol, etc., and applying and drying.

  Next, after applying the second layer (upper layer), as a method of drying the solvent very quickly, a method of blowing high-pressure air from a slit nozzle installed substantially perpendicular to the running direction of the web, heating with steam, etc. Examples thereof include a method in which heat energy is applied as conduction heat from the lower surface of the web from a roll (heating roll) supplied inside, or a combination of these methods.

  Moreover, in order to provide a new function, the upper layer and the lower layer may be partially miscible in a range where the effects of the present invention are sufficiently exhibited. Such a method can be achieved by adjusting the degree of any of the above methods using the difference in solvent solubility and the method of drying the solvent very quickly after coating the second layer.

The concentration of the above-described components (total solid content including additives) in the lower layer / upper layer coating solution to be coated on the support is preferably 1 to 50% by mass.
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
In particular, in order to prevent damage to the lower layer when the upper layer is applied, the upper layer application method is preferably a non-contact type. Further, although it is a contact type, it is possible to use bar coater coating as a method generally used for solvent-based coating, but it is desirable to perform coating by forward rotation in order to prevent damage to the lower layer.

The coating amount after drying of the lower layer component applied on the support of the lithographic printing plate precursor according to the invention is preferably in the range of 0.5 to 4.0 g / m ² , more preferably 0.6. It is in the range of ˜2.5 g / m ² . Within this range, good sensitivity, image formability, and printing durability can be obtained.
The coating amount after drying of the upper layer component is preferably in the range of 0.05 to 1.0 g / m ^2, more preferably in the range of 0.10~0.50g / m ^2. Within this range, good developability and image formability with no residual color or white spots are obtained.
The coating amount after drying of the combined lower and upper, preferably in the range of 0.5 to 4.0 g / m ^2, more preferably in the range of 0.7 to 2.5 g / m ^2. Within this range, good sensitivity, image formability, and printing durability can be obtained.

[Support]
The support used in the lithographic printing plate precursor according to the present invention is not particularly limited as long as it is a dimensionally stable plate having the required strength and durability. For example, paper, plastic (for example, , Polyethylene, polypropylene, polystyrene, etc., laminated paper, metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper on which a metal as described above is laminated or vapor-deposited, or a plastic film.

  Among them, in the present invention, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. Content of the different element in an alloy is 10 mass% or less.

Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements.
Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 mm.

Such an aluminum plate can be subjected to surface treatment such as roughening treatment or anodizing treatment as necessary. Hereinafter, such a surface treatment will be briefly described.
Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as described in JP-A-54-63902, a method in which both are combined can also be used.
The aluminum plate roughened as described above is subjected to an alkali etching treatment and neutralization treatment as necessary, and then subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface as desired. As an electrolyte used for anodizing treatment of an aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used and cannot be specified. However, in general, the concentration of the electrolyte is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm. ^{2. A} voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable. If the amount of the anodized film is 1.0 g / m ² or more, the printing durability is sufficient, the non-image part of the lithographic printing plate is hardly scratched, and the ink is attached to the scratched part during printing. It is preferable because “dirt” is less likely to occur. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary.

  The hydrophilization treatment used in the present invention is described in U.S. Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There is an alkali metal silicate method (for example, an aqueous solution of sodium silicate). In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, potassium fluoride zirconate described in Japanese Patent Publication No. 36-22063 and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272 are disclosed. A method of treatment with polyvinylphosphonic acid as described is used.

[Undercoat layer]
In the lithographic printing plate precursor according to the invention, an undercoat layer can be provided between the support and the recording layer as necessary. Various organic compounds are used as the primer layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, optionally substituted phenylphosphoric acid, naphthylphosphonic acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and hydrochloric acid of triethanolamine Hydroxy such as salt -Alanine, and hydrochlorides of amines having a group may be used in combination of two or more.

  The undercoat layer preferably contains a compound having an onium group. The compounds having an onium group are described in detail in JP-A Nos. 2000-10292 and 2000-108538. In addition, a compound selected from the group of polymer compounds having a structural unit represented by poly (p-vinylbenzoic acid) in the molecule can also be used. Specific examples of these polymer compounds include a copolymer of p-vinylbenzoic acid and vinylbenzyltriethylammonium salt, a copolymer of p-vinylbenzoic acid and vinylbenzyltrimethylammonium chloride, and the like. .

This organic undercoat layer can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. In this method, an aluminum plate is immersed in a solution obtained by dissolving the organic compound in an organic solvent or a mixed solvent thereof to adsorb the compound, and then washed with water and dried to provide an organic undercoat layer. . In the former method, the solution having a concentration of 0.005 to 10% by mass of the organic compound can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with basic substances such as ammonia, triethylamine, potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid.
The coating amount of the organic undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² . If it is within this range, sufficient printing durability can be obtained.
The lithographic printing plate precursor produced as described above is imagewise exposed and then developed.

[Back coat layer]
A back coat layer is provided on the back side of the support of the planographic printing plate precursor according to the present invention, if necessary. Such a back coat layer comprises a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. A coating layer is preferably used. Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide obtained therefrom is particularly preferable because of its excellent developer resistance.

[Exposure and development processing]
As the actinic ray light source used for image exposure of the lithographic printing plate precursor according to the present invention, a light source having an emission wavelength in the near infrared region to the infrared region is preferable, and a solid-state laser or semiconductor emitting infrared light having a wavelength of 700 to 1200 nm A laser is particularly preferred.

The exposed lithographic printing plate of the present invention is subjected to development treatment and post-treatment with a finisher, a protective gum or the like to form a printing plate. For these processes, a known processing apparatus such as an automatic processor can be used.
The processing agent used in the development processing and post-processing of the lithographic printing plate of the present invention can be appropriately selected from known processing agents.

  A suitable developer is a developer having a pH in the range of 9.0 to 14.0, preferably in the range of 12.0 to 13.5. As the developer, a conventionally known alkaline aqueous solution can be used. Among the above alkaline aqueous solutions, as a particularly suitable developer, an alkali silicate as a base, or a so-called “silicate developer” well known in the art containing an alkali silicate by mixing a silicon compound with a base. An aqueous solution having a pH of 12 or higher, a non-reducing sugar (an organic compound having a buffering action) and a base, which do not contain an alkali silicate, as described in JP-A-8-305039 and JP-A-11-109637 So-called “non-silicate developer” containing

  As the “silicate developer”, an aqueous solution of an alkali metal silicate as described in JP-A No. 54-62004 and JP-B No. 57-7427 is preferably used.

  As the “non-silicate developer”, those described in the above-mentioned publications are preferable. When the developer is used to develop a lithographic printing plate precursor, the surface of the recording layer is not deteriorated, and the recording layer The inking property can be maintained in a better state.

In addition to the above, as a developer used in the present invention, the molar ratio of SiO ₂ / M ₂ O (M represents an alkali metal) described in JP-A-6-282079 is 0.5 to 2.0. Preferred examples include a developer containing an alkali metal silicate and a water-soluble ethylene oxide addition compound obtained by adding 5 mol or more of ethylene oxide to a sugar alcohol having 4 or more hydroxyl groups.

  When the lithographic printing plate according to the present invention is subjected to a burning treatment, it is preferably carried out by a conventionally known method using a burning surface conditioning liquid and using a burning processor or the like.

  The lithographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

  EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.

[Synthesis Example 1]
Under a nitrogen stream, 29.8 g of P-cyanophenylmethacrylamide, 4.2 g of acrylonitrile, 8.0 g of methyl methacrylate, and 6.9 g of methacrylic acid were added to 146.7 g of 2-methoxyethanol, heated to 70 ° C., α, α'-Azobisisobutyronitrile (0.25 g) was added and a polymerization reaction was carried out for 8 hours. Thus, a 2-methoxyethanol solution of the specific alkali-soluble resin (1) according to the present invention described in Table 1 below was obtained. The nonvolatile content of this solution was 24.8% by mass. The obtained mixture was poured into 2 liters of water while stirring the water, and the mixture was stirred for 30 minutes, and then the precipitate was removed by filtration and dried to obtain 48.0 g of a white solid. It was. When the weight average molecular weight (polystyrene standard) of this alkali-soluble resin (1) was measured by gel permeation chromatography, it was 60,000.

(Production of support)
<Aluminum plate>
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.025 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: Containing 0.03% by mass, the balance is prepared using Al and an inevitable impurity aluminum alloy, and after performing the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by a DC casting method. Produced. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. The obtained aluminum had an average crystal grain size with a minor axis of 50 μm and a major axis of 300 μm. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.

<Surface treatment>
In the surface treatment, the following various treatments (a) to (k) were continuously performed. In addition, after each process and water washing, the liquid draining was performed with the nip roller.
(A) Mechanical surface roughening treatment While supplying a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water as a polishing slurry liquid to the surface of the aluminum plate, mechanical roughening is performed by a rotating nylon brush. Surface treatment was performed. The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6-10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.

(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. An electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode, using a trapezoidal rectangular wave alternating current with a time TP of 0.8 msec until the current value reached a peak and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type. The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(E) Alkaline etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.50 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.

(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used in the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in the nitric acid aqueous solution.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. An electrochemical surface roughening treatment was performed using a trapezoidal trapezoidal wave alternating current with a time TP of 0.8 msec until the current value reached a peak from zero, a duty ratio of 1: 1, and a trapezoidal trapezoidal wave alternating current. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.

(H) Alkaline etching treatment An aluminum plate was subjected to an etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was dissolved at 0.10 g / m ² . Removes the smut component mainly composed of aluminum hydroxide generated when electrochemical surface roughening treatment was performed using alternating current in the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.

(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(J) Anodizing treatment Anodizing device of two-stage feeding electrolytic treatment method (first and second electrolytic section length 6 m each, first and second feeding section length 3 m each, first and second feeding electrode section length 2.4 m each) Anodizing was performed using this. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 20 ° C. Then, water washing by spraying was performed. The final oxide film amount was 2.7 g / m ² .

(K) Alkali metal silicate treatment Alkali metal silicate is obtained by immersing the aluminum support obtained by anodizing treatment in a treatment tank of 1 mass% sodium silicate No. 3 solution at a temperature of 30 ° C. for 10 seconds. Salt treatment (silicate treatment) was performed. Thereafter, washing with water using well water was performed to obtain a support subjected to a surface silicate hydrophilization treatment.

〔undercoat〕
On the aluminum support after the alkali metal silicate treatment obtained as described above, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film. The coating amount of the coating film after drying was 15 mg / m ² .

<Undercoat liquid composition>
・ The following compound A 0.3g
・ Methanol 100g
・ Water 1g

[Preparation of lithographic printing plate precursor (1) Multilayer recording layer]
The lower layer coating solution 1 having the following composition was applied to the obtained web-like support having the undercoat layer with a bar coater so that the coating amount was 0.85 g / m ² , and then dried at 160 ° C. for 44 seconds, immediately. It cooled until the temperature of the support body became 35 degreeC with the cold wind of 17-20 degreeC. Thereafter, the upper layer coating solution 1 having the following composition was applied to a bar coater so that the coating amount was 0.22 g / m ² , dried at 148 ° C. for 25 seconds, and further slowly cooled with air at 20 to 26 ° C. for transportation. A lithographic printing plate precursor for use in the test was prepared.

<Lower layer coating solution 1>
-Alkali-soluble resin 2.133 g obtained in Synthesis Example 1
・ Cyanine dye A (the following structure) 0.134 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-methoxy-4-diazodiphenylamine hexafluorophosphate 0.032 g
・ The ethyl violet counter ion is changed to 6-hydroxynaphthalenesulfonate 0.0781 g
・ Polymer 1 (the following structure) 0.035g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g
・ Γ-butyrolactone 13.18g

<Upper layer coating solution 1>
・ M, p-cresol novolak 0.3479g
(M / p ratio = 6/4, weight average molecular weight 4500,
Contains 0.8% by mass of unreacted cresol)
-Polymer 3 (the following structure MEK 30% solution) 0.1403g
・ Cyanine dye A (the above structure) 0.0192 g
・ Polymer 1 (the above structure) 0.015 g
-Polymer 2 (the following structure) 0.00328g
・ Quaternary ammonium salt (the following structure) 0.0043g
・ Surfactant (polyoxyethylene sorbite fatty acid ester HLB8.5, GO-4 manufactured by Nikko Chemicals Co., Ltd.) 0.008 g
・ Methyl ethyl ketone 6.79g
・ 1-methoxy-2-propanol 13.07 g

[Preparation of lithographic printing plate precursor (2) Single-layer recording layer]
On the support having the undercoat layer obtained above, a recording layer (single layer) coating solution 1 having the following composition was applied and dried to form a recording layer having a coating amount of 1.8 g / m ^2. A comparative lithographic printing plate precursor for use in the transportation test was obtained.

<Recording layer (single layer) coating solution 1>
・ Novolak resin 1.5g
(M / p-cresol (6/4), weight average molecular weight 7,000,
Unreacted cresol 0.5% by mass)
・ Cyanine dye A (the above structure) 0.1 g
・ Phthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
・ The counter ion of ethyl violet is 6-hydroxy-β-naphthalenesulfonate
0.02g
・ Fluorine polymer 0.015g
(Megafuck F-176 (solid content 20%),
Dainippon Ink & Chemicals, Inc.)
・ Fluoropolymer 0.035g
(Megafuck MCF-312 (solid content 30%),
Dainippon Ink & Chemicals, Inc.)
・ Lauryl stearate 0.03g
・ Γ-Butyrolactone 8.5g
・ 3.5 g of 1-methoxy-2-propanol

[Examples 1 to 4 and Comparative Examples 1 to 8]
The multi-layer type and single-layer type lithographic printing plate precursors were packed under the packing conditions of (1) presence or absence of interleaving paper, (2) packing method, and (3) stacking number of sheets shown in Table 1. These packed products (stacked package) were loaded on a truck and made two round trips between Osaka and Tokyo. The lithographic printing plate precursor having such a transportation history was evaluated as follows.
The lithographic printing plate precursor was exposed with a trend setter 3244F (manufactured by Creo) under the conditions of a beam intensity of 5.5 W, a drum rotation speed of 150 rpm, and a resolution of 2400 dpi. The exposure image included a solid image. The exposed lithographic printing plate precursor thus obtained was developed by Fuji Photo Film Co., Ltd. with developer DT-2 (1: 8), gum solution FG-1 (1: 1), and self-supporting machine LP-940HII. The developer was developed under the conditions of a developer conductivity of 43 ms / cm, a solution temperature of 30 ° C., and a development time of 12 seconds. The obtained lithographic printing plate was visually observed for film loss in the solid image portion (missing white spots) and pot-like residual film in the non-image portion. The results are shown in Table 1.

  As is apparent from the above results, the recording layer multilayer type lithographic printing plate precursor according to the present invention laminated and packaged eliminates white spots in the image area and residual film in the non-image area. On the other hand, in the comparative example not satisfying the configuration and / or packing form of the planographic printing plate precursor of the present invention, satisfactory results were not obtained.

It is a perspective view which shows the package body of the laminated bundle of the lithographic printing plate which concerns on the 1st Embodiment of this invention. It is a perspective view which shows each laminated packing body, interior paper, and carrier pallet which concern on the 1st Embodiment of this invention. It is a perspective view which shows the lamination | stacking bundle | flux of the lithographic printing plate packed by the packing method which concerns on the 1st Embodiment of this invention by the flat stacking state. The structure at the time of adding a sheet | seat pallet to the package body of the laminated bundle of the lithographic printing plate which concerns on the 1st Embodiment of this invention is shown. It is a perspective view which shows the lamination | stacking bundle | flux of the lithographic printing plate packed by the packing method which concerns on the 2nd Embodiment of this invention in the vertically stacked state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Packing body 12 Stacking member 13 Contact ball 14 Planographic printing plate 16 Product bundle (lithographic printing plate bundle)
17 Interleaf paper 18 Binding band (binding member)
19 Bolt 20 Sheet pallet 22 Nipped part 24 Carrier pallet (carrier member)
26 Bottom plate 28 Top plate 30 Connecting member 32 Fork insertion portion 34 Interior paper 35 Exterior cardboard boxes 36A, 36B, 36C Exterior tape 38 Fixed band 40 Skid (carrier member)
42 Pallet portion 44 Fork insertion portion 46 Inclined plate 48 Back plate 50 Square contact member 52 Tightening belt 54 Fall prevention belt

Claims (1)

  The support contains a recording layer lower layer containing a resin that is water-insoluble and soluble in an alkaline aqueous solution, a resin that is water-insoluble and soluble in an alkaline aqueous solution, and a development inhibitor, and is dissolved in the alkaline aqueous solution by exposure. A recording layer upper layer having increased properties in this order, and at least one lithographic printing plate precursor containing an infrared absorber is laminated on at least one of the upper and lower recording layers to form a laminated bundle, and the laminated bundle is bound A laminated package of lithographic printing plate precursors obtained by packing and fixing the bound package on a carrier member.

Images