JPH08324146A - Indirect lithographic printing original plate - Google Patents

Abstract

PURPOSE: To obtain a printed matter of high quality level without scumming at the time of printing by incorporating zinc oxide and binder resin having specific betaine structure in a molecule in an image receiving layer in the lithographic printing original plate formed with the image receiving layer on a support. CONSTITUTION: The indirect lithographic printing original plate comprises a support and an image receiving layer to be used for an indirect lithographic printing of once forming an image at a place on a drum, transferring it to the original plate and then developing the image, wherein the receiving layer contains zinc oxide and 0.05 to 20wt.% of binder resin having betaine structure represented by a formula (R<1> , R<2> are each 1-5C alkyl group which may contain a hydrogen atom or hydroxyl group, n1 , n2 are respectively an integer of 1 to 5, and X is SO3 or COO) in a molecule. Plastic is preferably used for the support, and the receiving layer further contains pigment particles each having a mean particle size of 1 to 20μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indirect type lithographic printing plate precursor, and more particularly to an indirect type lithographic printing plate precursor capable of obtaining a high-quality printed matter having no background stain during printing.

[0002]

2. Description of the Related Art Conventionally, in a plate making process in the printing field, a direct plate for directly forming an image image required for printing on an original plate, and an image image once formed on a drum or the like and then used as an original plate. There are two types of indirect plates that transfer and develop. Due to recent advances in desk top publishing (DTP) systems and the spread of plate making systems using computers, these direct type plate making systems and indirect type plate making systems have come to be often used. Especially, it is often used in the field of light printing.

Indirect type lithographic printing is a method of printing using a lithographic printing plate precursor which is usually composed of a support and an image receiving layer as shown in FIG. The support of this original plate is generally paper or a plastic film, and the image receiving layer is a resin layer in which zinc oxide is used as a pigment and dispersed in a resin binder. An image of toner or oil-based ink is formed on this original plate using a normal copying machine, laser printer, thermal transfer printer, etc., and this image portion is used as the lipophilic ink portion (ink receiving layer), and the presence of the toner or oil-based ink The offset printing plate is obtained by hydrophilizing the non-existing portion with an etching solution containing potassium cyanide. This is used for printing using an offset printing machine.

Japanese Unexamined Patent Publication No. 5-116473 discloses the use of a solvent-soluble resin such as an acrylic resin as the binder resin. However, when a solvent-soluble resin is used as the binder resin, since the resin is hydrophobic, ink stains are likely to occur on the non-image area (the area where the toner is not bound) of the image receiving layer. Therefore, there is a drawback that the printed matter is liable to be stained.

Further, although paper is basically used as a support, the paper is liable to be damaged, and dimensional stability and printing durability are deteriorated by swelling with dampening water or ink solvent during printing. . In order to overcome such drawbacks, it is useful to use a plastic film as a support as disclosed in, for example, JP-A-6-191174, but conversely, the adhesion between the support and the image receiving layer. Since it deteriorates the property, scratches are likely to occur during handling during the print preparation process, and as a result,
There is a problem that printing stains are conspicuous and printing durability is deteriorated, and the effect of using a plastic film cannot be exhibited.

Further, JP-A-6-72058 discloses the use of a water-soluble resin such as polyvinyl alcohol or a water-dispersible resin such as an acrylic resin emulsion as the binder resin. In this case, it is unavoidable that the durability of the image receiving layer is swelled by the fountain solution or the ink solvent during printing and the printing durability is lowered due to the reduction of mechanical strength. Further, when a water-dispersible resin such as an emulsion resin is used, although the above-mentioned drawbacks are few, improvement in wettability and adhesiveness with a plastic support is necessary in order to improve printing durability. It has been.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and its object is to:
An object of the present invention is to provide an indirect type lithographic printing plate precursor which has a binder resin having improved adhesiveness to a plastic support and can obtain a high-quality printed matter free from background stain during printing.

[0008]

The present invention relates to a lithographic printing plate precursor comprising an image-receiving layer formed on a support, the image-receiving layer having zinc oxide and a compound represented by the general formula:

[Chemical 4] (In the formula, R ¹ and R ² are the same or different and are an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a hydroxyl group; n ₁ and n ₂ are integers of 1 to 5; and X Is SO ₃
Or COO; The present invention provides a lithographic printing plate precursor characterized by comprising a binder resin having a betaine structure represented by (4).

A. Pigment Used in Image Receiving Layer The image receiving layer contains zinc oxide as a pigment and a binder resin as essential components, and further contains various additives as required. The pigment dispersed in the image receiving layer is mainly zinc oxide. Zinc oxide is classified into a dry method and a wet method (activated zinc white) depending on the manufacturing method. The wet method generally has a particle size of 0.
It is as small as 1 μm or less, and 0.2 to 0.5 μm for the dry method. Further, as disclosed in JP-B-53-23797, JP-A-62-11860, JP-B-3-2298, etc., a zinc oxide powder produced by a wet method or a dry method is compressed under high pressure. After that, crushed, calcined, and classified zinc oxide having an average particle size of 1 to 20 μm and a relatively large particle size may be used if necessary. This is marketed as "Zinc flower for ceramic industry". Furthermore, a tetrapot-shaped zinc oxide whisker obtained by the production method disclosed in JP-A-3-150299 may also be used if necessary.

In the present invention, any one of them or a mixture of two or more may be used. In the present invention, the content of zinc oxide based on the total weight of the image receiving layer is preferably 75% by weight to 85% by weight. When the content of zinc oxide is less than 75% by weight, the amount of zinc oxide exposed on the surface of the image receiving layer decreases, so that the entire plate surface is not sufficiently and uniformly hydrophilized even if etching treatment is performed. However, it is not preferable because scumming is likely to occur during printing. On the contrary, if it exceeds 85% by weight, the amount of the binder resin compounded becomes too small, and it becomes difficult to sufficiently bind the pigment, which is not preferable.

B. Binder Resin Used in Image Receiving Layer In the present invention, the binder resin used in the image receiving layer has a general formula:

Embedded image (In the formula, R ¹ and R ² are the same or different and are an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a hydroxyl group; n ₁ and n ₂ are integers of 1 to 5; and X Is SO ₃
Or COO; ) Is a resin having a betaine structure and a number average molecular weight of 1,000 to 100,000. As a preferred method of synthesizing the binder resin having the betaine structure, (i) using a polymerizable monomer having a betaine structure, an oligomeric or polymeric resin is obtained by radical copolymerization with another ethylenically unsaturated polymerizable monomer. There are two possible methods: (ii) a method using a compound having a betaine structure as a starting material to perform esterification by a polycondensation reaction to obtain an oligomeric or polymeric resin.

First, in the method (i), the polymerizable monomer having a betaine structure is represented by the general formula

[Chemical 6] (In the formula, R ¹ and R ² are the same or different and are an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a hydroxyl group; n ₁ , n ₂ and n ₃ are integers of 1 to 5; And X is S
O ₃ or COO; R ³ represents a hydrogen atom or a methyl group; Y represents a bonding group having an ester or amide structure; ) A radically polymerizable monomer having a betaine structure represented by the following formulas, and examples thereof include JP-A Nos. 53-72091 and 53-12389.
There are monomers disclosed in No. 9, No. 53-125996, No. 55-47651, No. 55-47652 and the like. Particularly preferred among them are, for example: N, N-dimethyl-N-methacryloxyethyl-N- (3-sulfopropyl) -ammonium-betaine; N, N-dimethyl-N-methacrylamidopropyl-N- (3-sulfopropyl) -ammonium-betaine; N, N-dimethyl-N-methacryloxyethyl-N- (2-carboxyethyl) -ammonium-betaine; N, N-dimethyl-N-methacrylamidopropyl-N- (2-carboxyethyl) -ammonium-betaine; 1- (3-sulfopropyl) -2-vinyl-pyridinium-betaine;

[Chemical 7] Etc., some of which are commercially available from Raschig AG, Germany.

Other ethylenically unsaturated monomers copolymerizable with the above-mentioned betaine structure-containing polymerizable monomer include:
(I) Carboxyl group-containing monomer; for example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc., (II) Hydroxyl group-containing monomer; for example, 2-hydroxylethyl acrylate, hydroxypropyl acrylate, 2 -Hydroxyl ethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, allyl alcohol, methallyl alcohol, etc. (II
I) Nitrogen-containing alkyl acrylate or methacrylate;
For example, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc., (IV) polymerizable amide; for example, acrylic acid amide, methacrylic acid amide, N-methylol acrylamide, diacetone acrylamide, etc.
(V) Polymerizable nitrile; for example, acrylonitrile, methacrylonitrile, etc., (VI) Alkyl acrylate or methacrylate; For example, methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-butyl methacrylate, isopropyl methacrylate, (VII) Isocyanate group-containing monomer such as 2-ethylhexyl acrylate; for example, (meth) acrylic isocyanate, isocyanate ethyl methacrylate and the like.

In the polymerization reaction, a suitable solvent (for example,
Isopropanol, methoxypropanol, ethylene glycol monoethyl ether, butanol, xylene,
(Toluene, cyclohexanone, etc.), and further peroxides such as cumene hydroperoxide, di-t-butyl peroxide, benzoyl peroxide; or azobisisobutyrotolyl, 2,2'-azobis (2-methylbutyro) A solution polymerization reaction is carried out using an azo radical polymerization initiator such as nitrile).

When a water-dispersible resin (emulsion) is obtained, radical polymerization in the oil droplets of the mixed monomer is carried out in water in the presence of a suitable emulsifier. At that time, as the radical polymerization initiator, a water-soluble one such as potassium persulfate is suitable.

It is desirable that the composition of the synthesized binder resin contains 0.05 to 20% by weight, preferably 0.1 to 10% by weight, of the above-mentioned polymerizable monomer having a betaine structure, based on the total weight of the monomers. When the amount is less than 0.05% by weight, the effect shown in the present invention, that is, sufficient adhesiveness between the image receiving layer and the support cannot be obtained, and the printing durability is insufficient. Also,
As a result of lack of hydrophilicity of the image receiving layer at the time of desensitizing treatment before printing and insufficient effect of preventing ink stains on non-image areas during printing, background stains easily occur on the printed matter during printing. Also, 20
If the amount exceeds 5% by weight, if the degree of hydrophilicity of the image-receiving layer becomes excessive, water swelling of the plate is caused, and the dimensional stability and printing durability of the image during printing deteriorate.

In the method (ii) for synthesizing the binder resin, examples of the modified resin to be synthesized include modified alkyd resin, modified polyester resin, modified epoxy resin, modified acrylic resin, modified melamine resin, modified polyether resin and the like. As an example of the synthetic method (ii), preparation of modified alkyd resin and modified polyester resin is described in, for example, Japanese Patent Application No.
It may be carried out according to the method disclosed in Japanese Patent No. 10865 and Japanese Patent Application No. 55-56048. That is, the alkyd resin and the polyester resin are characterized by forming a continuous ester chain by using a polybasic acid and a polyhydric alcohol as essential components, but a part of the polyhydric alcohol component is represented by the formula: (In the formula, R ⁴ is an alkyl group having at least one hydroxyl group and having 1 to 5 carbon atoms; R ¹ and R ² are the same or different, and each of which may have a hydrogen atom or a hydroxyl group;
An alkyl group of 5; n ₁ is an integer of ₁ to 5; X is SO ₃ or COO; ) A compound represented by the formula: By substituting with N, N-dihydroxyethyltaurine represented by the above, the alkyd resin or polyester resin having the above betaine structure can be synthesized by an ordinary polycondensation reaction. Further, in the composition of the binder resin obtained by the synthetic method (ii), the polyhydric alcohol component having the betaine structure with respect to all components, as in (i), 0.05
It is desirable that the content is -20% by weight, preferably 0.1-10% by weight.

In the present invention, the binder resin content relative to the total weight of the image receiving layer is 10 to 10 in order to complement the content of the above-mentioned zinc oxide or pigment particles other than zinc oxide described below.
It is preferably 25% by weight. When the content of the binder resin is less than 10% by weight, the mechanical strength of the image receiving layer is reduced due to a lack of the binder component of the pigment containing zinc oxide as a main component, so that scratches may occur during handling in the printing process. It easily sticks, and the printing stains and printing durability deteriorate. On the other hand, when the content exceeds 25% by weight, zinc oxide becomes insufficient and the desensitizing treatment before printing becomes insufficient, so that the background stain on the printing becomes remarkable.

The suitable molecular weight range of the solvent-soluble resin is 1,000 to 100,000 (number average molecular weight). When the number average molecular weight is less than 1,000, the strength of the film (image receiving layer) is lowered and the printing durability is significantly impaired. On the contrary, if the number average molecular weight exceeds 100,000, the viscosity becomes very high,
There arises a problem that the workability at the time of coating and the leveling property of the obtained coating film are deteriorated. However, since the dispersion resin such as an emulsion has a low viscosity of the varnish, the upper and lower limits of the appropriate molecular weight may be higher, and the appropriate range is 50,000 to 500,000 in terms of number average molecular weight.

C. Additives Used in Image Receiving Layer In addition to the above-mentioned main components, the image receiving layer may optionally contain a slight amount of various additives such as an antistatic agent, a plasticizer or a pigment.

As the pigment, other than zinc oxide, inorganic pigments such as calcium carbonate, alumina, silica sand, clay, silica gel, precipitated barium, calcium sulfate, magnesium hydroxide, etc .; three-dimensional crosslinkable resin called microgel Particles; or organic pigments such as perylene, quinacridone, phthalocyanine, quinone or azo pigments. In particular, when a plastic film is used as the support, the surface of the image receiving layer is matted by adding a small amount (in the range of 1 to 5% by weight) of the above-mentioned inorganic or organic pigment particles having an average particle size of 1 to 20 μm. By (roughening), for example, JP-A-63-166590 and 63-31290.
As disclosed in the known art disclosed in Japanese Patent Publication No. 6-96353- and Japanese Patent Publication No. 6-96354, toner fog on a non-image area is not printed when a toner image is printed from a laser printer. It is important to prevent printing and eliminate print background stains in order to improve print quality. At that time, if the content of the pigment particles with respect to the total weight of the image forming layer is less than 1% by weight, matting is insufficient, toner fog on non-image areas cannot be eliminated, and more than 5% by weight. As a result, matting becomes excessive, the amount of toner adhered to the image area is insufficient, and a poor state in which only a poor toner image is formed is caused.

D. Preparation of image-receiving layer and proper coating amount The preparation of the printing plate of the present invention is carried out by adding the above-mentioned pigment, binder resin, water or solvent, additives such as antistatic agent to paint shaker, ball mill, sand mill, attritor, etc. By using a known coating method such as a bar coater, a doctor blade, a roll coater or a gravure coater, the image-receiving layer coating material dispersed by a known dispersing means is coated on a support described below and dried. To do. The proper coating amount of the image receiving layer per unit area in the printing plate of the present invention is in the range of 3 to 30 g / m ^{2 in} dry weight. If the coating amount is less than 3 g / m ² , the image-receiving layer becomes too thin, so that it is not sufficiently and uniformly hydrophilized even by the etching treatment, and scumming occurs. In addition, scumming easily occurs due to abrasion during printing. On the contrary, the coating amount is
If it exceeds g / m ² , the volume resistance of the image-receiving layer cannot be ignored, and toner or ink fog (scattering to the non-image area) tends to occur during image formation, which is unsuitable.

E. When the image-receiving layer is developed, the plate material thermally binds or thermally transfers toner and ink, but since it is heated at about 120 to 160 ° C for several seconds, the substrate has some thermal dimensional stability. It is necessary to have Therefore, as the material of the support, paper may be used, but a plastic film whose strength does not decrease due to water absorption by an etching solution or fountain solution during printing, for example, polyolefin (for example, polyethylene,
Polypropylene) or polyester is suitable,
In particular, a polyester film represented by polyethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexanedimethylene terephthalate, or the like is preferable.

Further, an antistatic support as disclosed in Japanese Patent Application No. 6-98473, in which a polymeric antistatic agent and a plastic are melt-kneaded and formed into a sheet, is more preferable.

As a more preferable plastic support,
An example of the resin material further includes inorganic pigment particles, and the surface of the film is roughened to have particle projections. For example, JP-A-4-93348 and JP-A-5-214122.
No. 5-331300, No. 4-323229, and the like. When the surface matted film is used, not only the adhesiveness to the image receiving layer is excellent due to the increase in the surface area, the effect of the present invention is increased, but also in the plate feeding when the plate is output from the laser printer, the feed roller is used. Friction coefficient with
The effect of preventing printing defects due to slippage is also expected. The support thickness is preferably in the range of 40 to 300 μm. In the above-mentioned development processing step when the support thickness is less than 40 μm,
When binding toner or transferring ink inside the printer,
It is recognized that the film may become unusable as a printing plate due to wrinkles due to thermal deformation. On the other hand, if the thickness of the support exceeds 300 μm, it becomes difficult to mount it on the plate cylinder of a light printing machine, which impairs printing.

F. Surface Treatment of Support Film A subbing layer (intermediate layer) may be provided between the support and the zinc oxide resin dispersion layer (image receiving layer) in order to improve the adhesiveness between the two. What constitutes the undercoat layer is mainly an adhesive, but various cationic, anionic, nonionic or amphoteric antistatic agents may be further added. As a specific example, saponified polyvinyl alcohol / isobutylene-maleic anhydride copolymer (Patent Document 1
5-318678), urethane resin (JP-A-5-64990), aromatic polyester resin / antistatic agent (JP-A-5-3)
The composition disclosed in the prior art such as JP 20391) may be used. In addition to providing an undercoat layer on the support film,
The adhesion may be improved by subjecting the film surface to plasma treatment.

G. Etching (hydrophilizing) the printing surface of the plate before printing After printing the image with toner or ink,
It is necessary to previously perform desensitizing (hydrophilizing) treatment on the non-image area of the plate material. An etching solution containing a ferrocyanide is usually used, and as a specific example, U.S. Pat. No. 3,672,88 is used.
5, 3,661,598, JP-A-5-338371, JP-A-53
-49506, 53-49507, 57-19969, 53-631
No. 01, No. 52-134501, Japanese Patent Publication No. 60-12958-, JP Sho
The one disclosed in Japanese Patent Publication No. 52-126302- is cited. Further, there is a non-cyan type etching solution mainly composed of an organic acid such as phytic acid, which can be used in the same manner as the cyan type etching solution. Specific examples include the compositions disclosed in US Pat. No. 4,734,132. The etching solution may contain a lower alcohol such as isopropyl alcohol in order to reduce the surface tension of water and enhance the wettability to the plate. The etching treatment is performed by impregnating an absorbent with an etching solution and rubbing the image receiving surface of the plate several times.

[0028]

According to the present invention, by containing the above betaine structure in the binder resin molecule constituting the image receiving layer of the lithographic printing plate precursor, the adhesiveness between the support and the image receiving layer is remarkably improved. Therefore, it is effective in preventing scratches during handling in the printing process, and printing stains based on the scratches can be eliminated. Also, printing durability is improved. Also,
Since the wettability of the plate surface non-printing area can be improved during the desensitizing treatment before printing or the supply of dampening water during printing, ink stains on the non-printing area during printing can be prevented and the background of the printed matter can be prevented. Can remove dirt.

[0029]

EXAMPLES The present invention will be described in more detail by way of examples.
The present invention is not limited to these examples. In the examples, "parts" or "%" are based on weight unless otherwise specified.

Production Example 1 (Binder Resin Production Example 1) A four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser was charged with 60 parts of methoxypropanol and 10 parts of methanol and heated to 60 ° C. Then, as a polymerizable monomer, a mixture of 20 parts of styrene, 71 parts of ethyl acrylate and 8 parts of 2-hydroxyethyl methacrylate, N, N-dimethyl-N-methacryloxyethyl-N- (3-sulfopropyl)
-Ammonium-betaine (manufactured by Raschig, Germany) 1 part methanol solution 10 parts, and radical polymerization initiator V-65 (Wako Pure Chemicals 2,2'-azobis- (2,4-dimethylvaleronitrile) )) 20 parts of 2 parts methoxypropanol solution was added dropwise from separate dropping funnels over 3 hours, and then heating and stirring was continued for 3 hours in a nitrogen stream. The obtained polymer solution had a solid content concentration of 50% by weight, or the number average molecular weight of the resin by GPC was 10,000.

Production Example 2 (Production Example 2 of Binder Resin) 70 parts of deionized water was charged into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, and heated to 80 ° C. As the polymerizable monomer, 20 parts of styrene, 70 parts of ethyl acrylate, 5 parts of 2-hydroxyethyl methacrylate, and 1- (3-sulfopropyl) -2-vinyl-pyridinium-betaine (manufactured by Raschig, Germany) Take 5 parts in a beaker, emulsify and disperse this monomer solution in 50 parts of an aqueous solution containing 1 part of sodium dodecyl sulfate with a homogenizer, and 10 parts of an aqueous solution containing 1 part of ammonium persulfate over 3 hours from separate dropping funnels. After the dropping, heating and stirring was continued for 2 hours in a nitrogen stream. The synthetic emulsion resin has a solid content of 40% by weight and an average particle size.
245 nm, and the number average molecular weight of the resin by GPC is 28
It was 0,000.

Production Example 3 (Binder Resin Production Example 3) A four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a decanter and a reflux condenser was used, and 5 parts of N, N-dihydroxyethyltaurine and phthalic anhydride were used. 23 parts, azelaic acid 15 parts,
33 parts neopentyl glycol and Epolite M-1230
24 parts (manufactured by Kyoeisha Chemical Co., Ltd.) were charged, melted at 150 to 230 ° C., and then polycondensed for 3 hours. that time,
In the presence of a small amount of xylene in the reaction system, water produced by dehydration due to polyesterification by azeotrope is removed from the system (decanter).
It was supposed to be distilled off. The obtained polymer solution had a solid content concentration of 98% by weight, and the number average molecular weight of the resin measured by GPC was
It was 3,000.

Production Example 4 (Production Example 4 of Binder Resin) 60 parts of methoxypropanol and 20 parts of methanol were charged into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen introducing tube and a reflux condenser, and heated to 65 ° C. After that, a mixture of 20 parts of styrene as a polymerizable monomer, 72 parts of ethyl acrylate and 8 parts of 2-hydroxyethyl methacrylate, and a radical polymerization initiator V-65 (2,2'-azobis- (2,4, manufactured by Wako Pure Chemical Industries, Ltd. -
20 parts of a methoxypropanol solution of 2 parts of dimethylvaleronitrile) was added dropwise from a separate dropping funnel over 3 hours, and then the mixture was further heated and stirred in a nitrogen stream for 3 hours. The obtained polymer solution had a solid content concentration of 50% by weight, or the number average molecular weight of the resin by GPC was 10,000.

Preparation Example 5 (Preparation Example 5 of Binder Resin) 70 parts of deionized water was charged into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen introducing tube and a reflux condenser, and after heating to 80 ° C., As a polymerizable monomer, 23 parts of styrene, 72 parts of ethyl acrylate, and 5 parts of 2-hydroxyethyl methacrylate were placed in a beaker, and this monomer solution was emulsified and dispersed in 50 parts of an aqueous solution containing 1 part of sodium dodecyl sulfate by a homogenizer. After 10 parts of an aqueous solution containing 1 part of ammonium sulfate was added dropwise from separate dropping funnels over 3 hours, the mixture was further heated and stirred in a nitrogen stream for 2 hours. The synthetic emulsion resin has a solid content of 40% by weight,
The average particle size was 250 nm, and the number average molecular weight of the resin by GPC was 300,000.

Production Example 6 (Production Example 6 of binder resin) 26 parts of phthalic anhydride, 15 parts of azelaic acid and neopentyl were placed in a four-necked flask equipped with a stirrer, a thermometer, a nitrogen introducing tube, a decanter and a reflux condenser. Charged 38 parts of glycol and 24 parts of Epolite M-1230 (Kyoeisha Chemical Co., Ltd.), 150-230
After melting at 0 ° C., polycondensation reaction was carried out for 3 hours. At that time, in the presence of a small amount of xylene in the reaction system, water produced by dehydration due to polyesterification by azeotropic distillation was distilled out of the system (decanter). The obtained polymer solution had a solid content concentration of 98% by weight, and the number average molecular weight of the resin by GPC was 3,000.

(Example 1) Surface matt polyethylene terephthalate film Melinex 377 (manufactured by ICI, USA, thickness 7)
Plasma treatment was performed on one surface (5 μm), and then a coating material having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). < Paint 1 for forming the image receiving layer> 80 parts by weight of zinc oxide (SAZEX # 2000 manufactured by Sakai Chemical Industry Co., Ltd.) 40 parts by weight of the binder resin solution of Production Example 1 0.2 parts by weight of maleic anhydride x 40 parts by weight of ethylene glycol 40 parts by weight of ethylene glycol monoethyl ether The above formulation and an appropriate amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output on the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with a C etchant (Cyan-based etchant manufactured by Iwasaki Tsushinki Co., Ltd.), and then attached to a small offset printing machine "AB Dick 360" manufactured by AB Dick in the United States, using a commercially available light-off ink. Printed on fine paper. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

[Table 1]

(Example 2) Surface-matted polyethylene terephthalate film Teijin U4 (manufactured by Teijin, thickness 100)
(μm) on one side by plasma treatment, a coating composition having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). <Image acceptance layer forming coating 2> zinc oxide (Sakai Chemical Co. SAZEX # 2000) 80 parts by weight Preparation Example 2 of the binder resin 50 parts by weight of isopropyl alcohol 9.8 parts by weight of water 6.0 parts by weight antistatic agent (San'nopuro made Nopukosutatto 092 ) 0.2 parts by weight or more of the compound and an appropriate amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output to the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Next, this plate was desensitized with 4-1080 (cyan-based etching solution manufactured by ABDick in the United States), and then mounted on a small offset printing machine "AB Dick 360" manufactured by ABDick in the United States to use a commercially available light-off ink for fine quality. Printed on paper. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

Example 3 Surface-matted polyethylene terephthalate film Melinex 377 (manufactured by ICI, USA, thickness 7)
Plasma treatment was performed on one surface (5 μm), and then a coating material having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). < Paint 3 for forming the image receiving layer> 80 parts by weight of zinc oxide (SAZEX # 2000 manufactured by Sakai Chemical Co., Ltd.) 20 parts by weight of the binder resin solution of Production Example 3 0.2 parts by weight of maleic anhydride x 50 parts by weight of ethylene glycol 50 parts by weight of ethylene glycol monoethyl ether The above formulation and an appropriate amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output on the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with a C etchant (Cyan-based etchant manufactured by Iwasaki Tsushinki Co., Ltd.), and then attached to a small offset printing machine "AB Dick 360" manufactured by AB Dick in the United States, using a commercially available light-off ink. Printed on fine paper. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

(Example 4) Surface-matted polyethylene terephthalate film Teijin U22 (manufactured by Teijin, thickness 100)
A coating composition having the following composition was applied to one side (easy-adhesion treated side) of 10 μm) using a bar coater so as to have a dry weight of 10 g / m ² and dried (100 ° C., 10 minutes). <Coating 4 for Image-receiving layer formed> zinc oxide (Sakai Chemical Co. SAZEX # 2000) 72 parts by weight of ceramic for zinc white (white water Chemical Co., Ltd., average particle size 5.2 .mu.m) 8 parts by weight of silica particles (manufactured by Tokuyama Ekuserika 8, average Particle size 8 μm) 2 parts by weight Binder resin solution of Production Example 36 parts by weight Maleic anhydride 0.2 parts by weight Xylene 40 parts by weight Ethylene glycol monoethyl ether 40 parts by weight The above composition and appropriate amount of glass beads are put into a glass sample tube. The mixture was charged and dispersed with a paint shaker for 2 hours to obtain a predetermined paint. A toner image was output to the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with PP Clean H (a cyan-based etching solution manufactured by Nikken Chemical Laboratory) and
It was attached to a small offset printing machine “AB Dick 360” manufactured by Dick and printed on high-quality paper using a commercially available light-off ink.
Table 1 shows ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter.
It was shown to.

Comparative Example 1 Surface matt polyethylene terephthalate film Melinex 377 (manufactured by ICI, USA, thickness 7)
Plasma treatment was performed on one surface (5 μm), and then a coating material having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). <Images receiving layer coating 5> zinc oxide (Sakai Chemical Co. SAZEX # 2000) 0.2 parts by weight of 80 parts by weight Production Example 4 Binder resin solution 40 parts by weight maleic anhydride xylene 40 parts by weight of ethylene glycol monoethyl ether 40 weight The above components and a suitable amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output to the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with C etchant (cyan-based etchant manufactured by Iwasaki Tsushinki Co., Ltd.), and then ABDick in the United States.
It was attached to a small offset printing machine "AB Dick 360" manufactured by the same company and printed on high-quality paper using a commercially available light-off ink. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

(Comparative Example 2) Surface-matted polyethylene terephthalate film Teijin U4 (manufactured by Teijin, thickness 100)
(μm) on one side by plasma treatment, a coating composition having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). <Image acceptance layer forming coating 6> zinc oxide (Sakai Chemical Co. SAZEX # 2000) 80 parts by weight Preparation Example 5 of binder resin 50 parts by weight of isopropyl alcohol 9.8 parts by weight of water 6.0 parts by weight antistatic agent (San'nopuro made Nopukosutatto 092 ) 0.2 parts by weight or more of the compound and an appropriate amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output to the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Next, this plate was desensitized with 4-1080 (cyan-based etching solution manufactured by ABDick in the United States), and then mounted on a small offset printing machine "AB Dick 360" manufactured by ABDick in the United States to use a commercially available light-off ink for fine quality. Printed on paper. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

(Comparative Example 3) Surface matt polyethylene terephthalate film Melinex 377 (manufactured by ICI, USA, thickness 7)
Plasma treatment was performed on one surface (5 μm), and then a coating material having the following composition was applied using a bar coater to a dry weight of 10 g / m ² , and dried (100 ° C., 10 minutes). < Paint 7 for forming image receiving layer> 80 parts by weight of zinc oxide (SAZEX # 2000 manufactured by Sakai Chemical Industry Co., Ltd.) 20 parts by weight of the binder resin solution of Production Example 6 0.2 parts by weight of maleic anhydride x 50 parts by weight of ethylene glycol 50 parts by weight of ethylene glycol monoethyl ether The above formulation and an appropriate amount of glass beads were charged into a glass sample tube and dispersed for 2 hours with a paint shaker to obtain a predetermined paint. A toner image was output on the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with a C etchant (Cyan-based etchant manufactured by Iwasaki Tsushinki Co., Ltd.), and then attached to a small offset printing machine "AB Dick 360" manufactured by AB Dick in the United States, using a commercially available light-off ink. Printed on fine paper. Ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter are shown in Table 1.

(Comparative Example 4) Surface-matted polyethylene terephthalate film Teijin U22 (manufactured by Teijin, thickness 100)
A coating composition having the following composition was applied to one side (easy-adhesion treated side) of 10 μm) using a bar coater so as to have a dry weight of 10 g / m ² and dried (100 ° C., 10 minutes). <Images receiving layer coating 8> zinc oxide (Sakai Chemical Co. SAZEX # 2000) 72 parts by weight of ceramic for zinc white (white water Chemical Co., Ltd., average particle size 5.2 .mu.m) 8 parts by weight of silica particles (manufactured by Tokuyama Ekuserika 8, average Particle size 8 μm) 2 parts by weight Binder resin solution of Preparation Example 36 36 parts by weight Maleic anhydride 0.2 parts by weight Xylene 40 parts by weight Ethylene glycol monoethyl ether 40 parts by weight The above composition and appropriate amount of glass beads are put into a glass sample tube. The mixture was charged and dispersed with a paint shaker for 2 hours to obtain a predetermined paint. A toner image was output to the lithographic printing original plate obtained by the above method using a laser printer (“Unity 1200XJ” manufactured by US Laser Master). Then, this plate was desensitized with PP Clean H (a cyan-based etching solution manufactured by Nikken Chemical Laboratory) and
It was attached to a small offset printing machine “AB Dick 360” manufactured by Dick and printed on high-quality paper using a commercially available light-off ink.
Table 1 shows ink stains (background stains) and print resistance (evaluated by abrasion of 5% halftone dots of 110 lines / inch) in non-image areas of the printed matter.
It was shown to.

[Brief description of drawings]

FIG. 1 is a process diagram schematically showing an indirect printing method.

Claims (7)

[Claims] 1. A lithographic printing plate precursor comprising an image-receiving layer formed on a support, the image-receiving layer having zinc oxide and a molecule of the general formula: (In the formula, R ¹ and R ² are the same or different and are an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a hydroxyl group; n ₁ and n ₂ are integers of 1 to 5; and X Is SO ₃
Or COO; ) A lithographic printing plate precursor containing a binder resin having a betaine structure represented by 2. The binder resin contains a component having a betaine structure represented by the general formulas (I) and / or (II) in an amount of 0.05 to 20% by weight. The lithographic printing plate precursor described in 1. 3. The binder resin has the general formula: (In the formula, R ¹ and R ² are the same or different and are an alkyl group having 1 to 5 carbon atoms which may have a hydrogen atom or a hydroxyl group; n ₁ , n ₂ and n ₃ are integers of 1 to 5; And X is S
O ₃ or COO; R ³ represents a hydrogen atom or a methyl group; Y represents a bonding group having an ester or amide structure; ) Is a radically polymerizable monomer having a betaine structure,
It is characterized by being a dissolution type acrylic resin having a number average molecular weight of 1,000 to 100,000 or a dispersion type acrylic resin (acrylic emulsion resin) having a number average molecular weight of 50,000 to 500,000, which is radically copolymerized in the range of 0.05 to 20% by weight. The lithographic printing plate precursor as described in Item 1. 4. The binder resin has the general formula: (In the formula, R ⁴ is an alkyl group having at least one hydroxyl group and having 1 to 5 carbon atoms; R ¹ and R ² are the same or different, and each of which may have a hydrogen atom or a hydroxyl group;
N is an integer of ¹ to 5; X is SO ₃ or COO; The alcohol component having a betaine structure represented by) is a soluble polyester resin having a number average molecular weight of 1,000 to 100,000, which is obtained by polycondensation in an amount of 0.05 to 20% by weight. Original plate for lithographic printing described. 5. A lithographic printing plate precursor, wherein the support is a plastic film. 6. The image receiving layer further has an average particle size of 1 to 20.
A lithographic printing plate precursor containing micrometer pigment particles. 7. A lithographic printing method carried out by using an offset printing machine by desensitizing the lithographic printing plate precursor according to claim 1.