JPH09311443A - Binder polymer for producing ink repellent planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a binder polymer having both crosslinkability and ink repellency and easy to produce. SOLUTION: Addition polymerizable unsatd. groups are introduced into a polymer of a monomer having at least one of carboxyl and sulfonic acid groups by the reaction of carboxyl or sulfonic acid groups in the polymer with an isocyanato compd. having an addition polymerizable unsatd. group and part of the remaining carboxyl or sulfonic acid groups are converted into an alkali metallic salt or an alkaline earth metallic salt to obtain the objective binder polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinkable ink-repellent binder polymer used in a dry processable planographic material. Here, the dry process refers to a process in which a printing plate can be manufactured by a plate-making process which does not require a washing step after image exposure.

[0002]

2. Description of the Related Art A plate material used for lithographic printing has several constitutions and a plate-making method corresponding thereto. The method most often used is a method in which a lipophilic photoresist film is provided on an anodized aluminum substrate and the photoresist film forming the non-image area is washed off after image exposure to form a printing plate. In addition, a planographic material using a silver salt is a system in which after development, development is performed to elute the silver salt in the unexposed area to form a non-image area. Further, there is a waterless planographic material in which a silicone rubber layer is provided on a lipophilic layer, which is a method of washing and removing the silicone rubber layer of the image forming portion after exposure or decomposing and removing the silicone rubber layer of the image portion during laser exposure.

All of the above-mentioned plate materials of the plate making system mentioned above require some kind of development and inevitably generate waste. Development control work was indispensable in order to minimize the fluctuation in image forming quality due to the need for development. Further, in recent years, regulations on industrial waste have become more and more strict, and in any of the above methods, industrial waste treatment is indispensable, which is a factor of increasing plate making costs.

In order to solve these problems, it is necessary to have a plate-making principle capable of producing a lithographic plate without removing any components of the plate-like material in the image / non-image forming step and a plate-like material structure for realizing the same. The point lies in the crosslinkable ink-repellent binder polymer. Conventionally, some ink-repellent binder polymers are known (for example, JP-A-53).
-21602, JP-A-6-258837,
JP-A-7-253671 and JP-A-7-00184.
No. 9, etc.), which are non-crosslinkable and have insufficient printing durability for use in ordinary lithographic printing and / or ink repellency, particularly ink repellency for low viscosity inks such as lithographic printing inks for newspapers. There was a problem of lack of sex. There is also a problem that it is not easy to introduce a crosslinkable group, particularly an addition-polymerizable unsaturated group.

[0005]

An object of the present invention is to provide a lithographic plate which is easy to produce a polymer and has excellent cross-linking property and excellent ink repellency even for a low viscosity ink such as a lithographic printing ink, especially a newspaper ink. It is intended to provide a binder polymer for a material and a planographic material using the binder polymer.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have found that addition-polymerizable by reacting a polymer consisting of a monomer containing at least either a carboxyl group or a sulfonic acid group with an addition-polymerizable unsaturated group-containing isocyanato compound. The inventors have found that the above-mentioned problems can be solved by introducing an unsaturated group and chlorinating a part of the remaining carboxyl group and sulfonic acid group with an alkali metal salt or an alkaline earth metal, and arrived at the present invention.

That is, the present invention is as follows. (1) Addition-polymerizable unsaturated group by reaction of a carboxyl group or a sulfonic acid group in a polymer composed of a monomer containing at least either a carboxyl group or a sulfonic acid group with an addition-polymerizable unsaturated group-containing isocyanato compound And a part of the remaining carboxyl group and sulfonic acid group are converted to an alkali metal salt or an alkaline earth metal salt to provide a crosslinkable binder polymer for lithographic production. (2) Number average molecular weight is 1.5 × 10 ³ to 30 × 10 ^4.
The binder polymer for lithographic printing plate production according to 1 above. (3) The rate of introduction of the addition-polymerizable unsaturated group is 5 to 20 mol% with respect to 100 mol of the polymer chain-constituting monomer.
Binder polymer for lithographic production. (4) Alkali metal salt of carboxylic acid group or sulfonic acid group or alkaline earth metal has a salinization ratio of 40 equivalents or more based on 100 total equivalents of carboxyl group or sulfonic acid group in the polymer before introduction of the addition-polymerizable unsaturated group, 95 The binder polymer for producing a lithographic plate according to the above 1, which is at most equivalent. (5) The binder polymer for lithographic plate production as described in 1 above, wherein the carboxyl group-containing monomer is at least one of acrylic acid, methacrylic acid, and itaconic acid. (6) The binder polymer for lithographic plate production as described in 1 above, wherein the sulfonic acid group-containing monomer is at least one of sulfoethyl acrylate, sulfoethyl methacrylate, acrylamidomethylpropane sulfonic acid, and methacrylamide amidopropane sulfonic acid. (7) The above-mentioned 1 in which the addition-polymerizable unsaturated group-containing isocyanato compound is at least one of 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate.
Binder polymer for lithographic production. (8) A planographic material for a dry process, which uses the binder polymer for producing a planographic plate as described in 1 above.

Hereinafter, the present invention will be described in detail. The binder polymer of the present invention is at least a carboxyl group, a carboxyl group or a sulfonic acid group in a polymer synthesized from a monomer containing any of a sulfonic acid group, and by reaction with an addition polymerizable unsaturated group-containing isocyanato compound. Addition-polymerizable unsaturated groups are introduced.

As the carboxyl group- and sulfonic acid group-containing monomers that can be used for producing the binder polymer of the present invention, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, sulfoethyl acrylate and sulfoethyl. Examples thereof include methacrylate and vinyl sulfonic acid. Among these, acrylic acid, methacrylic acid, itaconic acid, sulfoethyl acrylate, and sulfoethyl methacrylate are preferable from the viewpoint of polymerizability, handleability, and ink repellency. One or several of these monomers are selected and polymerized.

Polymerization is carried out by dissolving or dispersing the above monomers in water, an organic solvent or a mixed solvent of water and an organic solvent,
It can be easily carried out by carrying out radical polymerization using an ordinary radical polymerization initiator. The solvent is not particularly limited as long as it is selected in consideration of separation of the produced polymer and cost. However, in the case of using water or a proton-based organic solvent, it is necessary to remove the solvent and change to an aprotic solvent after the completion of the polymerization reaction. Therefore, it is preferable to use an aprotic organic solvent from the beginning to save the trouble of removing the solvent if it does not interfere with the polymerization reaction.

As the radical polymerization initiator, known initiators such as azo type initiators, peroxide type initiators and redox type initiators may be used. The selection may be made in consideration of the reaction temperature, solvent, desired average molecular weight, residual initiator post-treatment, and the like. Usually, azo initiators such as azobisisobutyronitrile and azobisvaleronitrile, and peroxide initiators such as benzoyl peroxide are used. The addition concentration is determined in consideration of the desired average molecular weight of the polymer and the initiation efficiency of the radical polymerization initiator. At the time of addition reaction to be carried out after using excessively,
It is important to add an appropriate amount so that it does not substantially remain. If the amount of residual initiator cannot be ignored after the polymerization reaction,
It is heated to deactivate it or subjected to an operation of isolating and purifying the polymer once obtained.

The end point of the polymerization is monitored by using GPC and is set to a time point when the desired average molecular weight is reached, and when the end point is reached, the reaction is cooled and the next addition reaction step is started. (Hereinafter, the polymer before the addition reaction step is abbreviated as a primary polymer.) The addition-polymerizable unsaturated group-containing isocyanato compound used in the subsequent addition reaction is 2-isocyanatoethyl acrylate or 2-isocyanatoethyl methacrylate. , Acrylic isocyanato, methacryl isocyanato, and the like. 2-Isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate are preferred from the viewpoint of handling the isocyanato compound.

The reaction between the obtained primary polymer and the addition-polymerizable unsaturated group-containing isocyanate compound is carried out after controlling the water content in the reactor. This is because the presence of reactive by-products with the isocyanate compound cannot be ignored if the water content is high,
In addition, the addition rate with the primary polymer cannot be controlled. To remove water in the reaction vessel, repeat the reduced pressure dehydration operation,
Control to several thousand ppm. The water content may be measured by a known method, but the Karl Fischer method is simple.

Since the isocyanato compound generates a large amount of heat when added all at once, it is put in a dropping funnel together with the dehydrated solvent and added within a range of several tens of minutes, and the reaction vessel is gradually heated to several tens of degrees Celsius until the end of the reaction. React with stirring. Usually, the reaction is carried out in the range of 50 to 90 ° C. Although the reaction proceeds sufficiently without a catalyst, it is preferable to use a urethanation catalyst in combination when the reaction is carried out at a low temperature or when the reaction is a carboxyl group at a position where steric hindrance is likely. Examples of usable catalysts include ordinary urethanization catalysts such as dibutyltin dilaurate. The end point of the reaction may be the end point when the characteristic absorption of the isocyanato group is substantially no longer observed by infrared spectrophotometry, or when the peak of the isocyanato compound is substantially no longer detectable by the gas chromatography method. In order to prevent gelation during the reaction, a thermal polymerization inhibitor is preferably added in an amount of 0.1 to 5% by weight of the whole system. A known polymerization inhibitor may be used as the inhibitor, and there is no particular limitation. 2,4-di-t-butyl-
Examples thereof include p-cresol, p-methoxyphenol, hydroquinone and the like.

The addition-polymerizable unsaturated group is introduced into the primary polymer by the reaction of a carboxyl group or a sulfonic acid group and an isocyanato group. The introduction rate is within the range of 3 to 30 mol% of the polymer chain-constituting monomer. preferable. When it is less than 3 mol%, the printing durability is deteriorated, and when it exceeds 30 mol%, the addition-polymerizable unsaturated group is wasted because it does not effectively participate in the cross-linking reaction, and when cross-linked, it becomes too hard and rather brittle. And the ink repellency is lowered. The range of 5 to 20 mol% is more preferable because various performances are balanced and there is no waste. The introduction ratio of the addition-polymerizable unsaturated group may be determined by any of an acid value before and after the reaction and an NMR method.

In order to stabilize the ink repellency of the binder polymer of the present invention, a part of the carboxyl group or sulfonic acid group in the binder polymer is neutralized with an alkali metal or an alkaline earth metal to form a salt. This chlorination rate is preferably 30 equivalents or more and 97 equivalents or less, when the total equivalents of the carboxyl group and the sulfonic acid group in the primary polymer are 100 equivalents. If it is less than 30 equivalents, the ink repellency may not be stable, which is not preferable. If it exceeds 97 equivalents, the water resistance of the plate becomes poor. More preferably,
When the amount is 40 equivalents or more and 95 equivalents or less, ink repellency and water resistance are easily balanced.

The number average molecular weight of the binder polymer of the present invention is such that it is easy to use when polymer treatment or coating composition is adopted,
1.5 × 10 ³ to 30 × 10 in terms of printing durability when used as a plate
A range of ⁴ is preferred. More preferably, it is 5 × 10 ³ or more.
The range of 20 × 10 ⁴ is easier to use. Here, the number average molecular weight is a reduced molecular weight obtained by the GPC method, and the details of the measuring method will be described in Examples. Usually, this measurement is carried out on the polymer before treatment with an alkali metal or alkaline earth metal salt.

A small amount of monomers containing neither a carboxyl group nor a sulfonic acid group can be used as a constituent monomer of the binder polymer of the present invention, but the addition of the addition-polymerizable unsaturated group of the present invention does not affect the ink repellency. Limited to those that do not interfere with. A lithographic material for a dry process can be produced by using the binder polymer obtained in the present invention. As the support, a sheet of steel, aluminum, plastic, paper or the like provided with an anchor layer if necessary is used. The anchor layer can be provided by applying an acrylic, urethane, cellulose, or polyallylamine adhesive. The anchor layer may be provided when necessary such as imparting printing durability. It is provided by coating a light-sensitive or heat-sensitive layer on a support. The components constituting the light-sensitive or heat-sensitive layer are composed of the binder polymer of the present invention, an image forming component and other necessary components. When the image forming component is microencapsulated, it is possible to prevent scumming caused by direct distribution of the image forming component on the plate surface in the non-image area, and further in a system where the binder polymer and the image forming component react with each other. However, they are isolated from each other except in the area where an image is formed, which is preferable in terms of storage stability of the plate. The microencapsulation of the image forming component can be carried out by a known technique such as an interfacial polymerization method, an in-situ method, a room temperature solid substance pulverization method in a liquid substance capable of reacting with a core substance, and the like. The core substance may be selected depending on the purpose, such as a lipophilic substance itself or a substance that reacts with the functional group of the ink-repellent carrier of the binder polymer. Further, a photopolymerization initiator, a sensitizer, and a photothermal conversion agent are added depending on the image forming means. These may be inside or outside the microcapsules. Recently, lithographic printing in the near-infrared laser printing mode has attracted attention, and even in that case, when it is used as heat, a known photothermal conversion agent such as cyanine or polymethine is used. Specific examples thereof are described in JP-A-7-001849.

The lithographic material for dry process thus produced is printed according to the image exposure method, for example, printing with an ultraviolet light mode laser, visible light mode laser, near infrared light mode laser, or thermal mode printing with a thermal head. An image is formed by an image forming method by digital image recording such as the above, or an image forming method by analog image recording through an image carrier such as a positive film, a negative film, etc. Printing plates can be produced without the need. Recently, a direct system for recording a digital image without using the film has been attracting attention.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is further described below with reference to examples.
This will be described specifically. In the text, parts are heavy unless noted
It is a quantity part. The primary polymer and binder polymer
-Based GPC method for number average molecular weight measurement is performed as follows.
Was. Equipment: TRI-ROTAR VI, manufactured by JASCO
Ram: SB-804HQ 1 piece, Guard column: SB-
G 1 bottle, eluent: NaNO _Three50 mM aqueous solution, column
Temperature: 30 ° C, flow rate: 0.5 ml / min, detector: R
I, calibration curve preparation standard substance: PEG-PEO.

[0021]

Example 1 Acrylic acid 216 in a separable flask
Parts and 1,920 parts of toluene and azobisisobutyronitrile (hereinafter abbreviated as AIBN) while stirring at room temperature.
2.46 parts were gradually added dropwise. Then, it heated up at 60 degreeC and stirred for 3 hours. The produced and precipitated polymer was filtered, washed with about 2 liters of toluene, and dried at 80 ° C. Then, the polymer was transferred to a separable flask containing water and dissolved. Acetonitrile was added dropwise to the solution to re-separate and wash the polymer. The filtered polymer was dried to a constant weight to obtain 204 parts of primary polymer (number average molecular weight by GPC method: 6 × 10 ⁴ ).

Next, N, N- in a separable flask is used.
Dimethylformamide (hereinafter abbreviated as DMF) was charged with 27.3 parts of the primary polymer. Dehydration under reduced pressure is performed to measure the water content in the solution by the Karl Fischer method, and 1800 pp
When m was reached, 9.3 parts of 2-isocyanatoethylmethacrylate and 2,6-di-t-butyl-p-cresol (BHT) dissolved in dry DMF in a dry air stream.
0.1 part and was added over 30 minutes while stirring the inside of the flask from the dropping funnel. After the addition was completed, the temperature was gradually raised to 6
When the mixture was stirred at 0 ° C. for 1 hour, the characteristic absorption of the isocyanato group could not be detected by infrared spectroscopy. Cool the contents,
The polymer was isolated and dried in acetonitrile, dissolved in methanol again, and then isolated and purified in acetonitrile to obtain an addition polymerizable unsaturated group-containing binder polymer (addition polymerizable unsaturated group introduction ratio by NMR method: 5. 3 mol%). This polymer was dissolved in water and carboxylic acid was neutralized with a calculated amount of caustic soda in an amount of 80 equivalent% to produce a binder polymer (BP1) of the present invention (number average molecular weight before sodium chloride: 6.5 × 10 ⁴ ). .

[0023]

Example 2 In the same manner as in Example 1, the number average molecular weight is 12 ×.
10 ⁴ polyacrylic acid primary polymer was obtained. To 28.5 parts of the primary polymer, 8.1 parts of 2-isocyanatoethyl acrylate was added and reacted. The polymer obtained was isolated, and the introduction rate of the addition-polymerizable unsaturated group was measured by the NMR method. This polymer was dissolved in water, partially neutralized with caustic soda, and sodium chloride was added to 70 equivalent% of the carboxylic acid to prepare a binder polymer (BP2) of the present invention (number average molecular weight before sodium chloride: 14 × 10 ⁴ ).

[0024]

[Example 3] 300 parts of acetone in a separable flask,
21 parts of sulfoethyl methacrylate, 1 acrylic acid
AIBN 0.52 dissolved in acetone was added while 5.8 parts was charged and heated at 45 ° C. in a nitrogen stream and stirred.
Parts were added dropwise over about 30 minutes. After stirring for 6 hours, the polymer formed was filtered and washed with acetone several times, and it was confirmed that the radical polymerization initiator and the monomer were almost not left. The polymer was vacuum dried to obtain a primary polymer (number average molecular weight by GPC method: 16.4 × 1).
0 ⁴ . The monomer composition ratio in the polymer obtained from the elemental analysis was 33/67 in the above order, which generally corresponded to the charged molar ratio. ) Next, 10.8 parts of the primary polymer was added to toluene 133
Parts and 0.012 parts of BHT were weighed into a separable flask already charged and stirred in a dry air stream with stirring 9
The temperature was raised to 0 ° C. 1.6 parts of 2-isocyanatoethyl methacrylate and 0.03 part of dibutyl tin dilaurate were gradually dripped there. After stirring for about 9 hours, the reaction proceeded until the characteristic absorption of the isocyanato group in infrared spectroscopy was almost negligible. The dispersed polymer was filtered, washed with acetone several times, and dried in vacuum (the introduction ratio of the addition-polymerizable unsaturated group measured by the NMR method was 5.6 mol%).
The obtained polymer was dissolved in water, and 60 equivalent% of the carboxyl group and the sulfonic acid group were partially neutralized with caustic potash to produce the binder polymer (BP3) of the present invention (number average molecular weight before potassium chloride: 17. 3 × 10 ⁴ ).

[0025]

Comparative Example 1 A binder polymer (BP4) was produced in the same manner as in Example 1 except that sodium carboxylation of the carboxyl group in the binder polymer was not performed.

[0026]

Comparative Example 2 2-hydroxyethyl acrylate 52.
2 parts, acrylamide 35.5 parts, acrylic acid 3.6
Part, dodecyl mercaptan 0.9 part, and water / isopropyl alcohol (1/1 weight ratio) 100 parts mixed solution were heated to 70 ° C. in a reactor. AIBN (1 part) was added thereto, and the mixture was reacted for 5 hours. Subsequently, 7.2 parts of glycidyl methacrylate, 0.5 part of t-butyl hydroquinone, and 1 part of benzyltrimethylammonium chloride were added, and 1 part was added.
The reaction was carried out at 30 ° C for 6 hours. Then, acetone was added to precipitate and wash the polymer to produce a binder polymer (BP5) (number average molecular weight: 1.5 × 10 ⁴ , introduction rate of methacrylic group measured by NMR was 4 mol%).

[0027]

Examples 4 to 6 and Comparative Examples 3 to 4 Examples 1 to 3 were prepared by applying an anchoring agent having the following composition to an aluminum plate having a thickness of 0.2 mm, which was electrolytically polished after degreasing, and dried and cured. 10 parts of the binder polymer produced in Comparative Examples 1-2, radical polymerization initiator; (2-acryloyloxyethyl) (4
-Benzoylbenzyl) dimethyl ammonium bromide
A dope solution consisting of 2 parts and 80 parts of water was applied with a bar coater, dried, and then exposed to ultraviolet light in a nitrogen atmosphere (exposure amount: 7 J /
cm ² ), and a plate having only a non-image area was prepared (thickness of coating layer: 3 μm). Anchor composition: 10 parts of polyallylamine (PAA-10C, 10 wt% aqueous solution manufactured by Nitto Boseki),
Polyethylene glycol diglycidyl ether (n =
9) 0.8 parts, 8 parts acetone.

These plates were sequentially mounted in an offset printing machine, and printing was carried out using off-wheel ink for newspaper (manufactured by Nihon Shimbun Ink) as ink and Don Etch (manufactured by Nihon Shimbun Ink) as dampening water. The results are shown in Table 1. In Table 1, the reflection density of paper is based on Dainippon Screen Mfg. Co., Ltd.
Made by a reflection densitometer DM400, thickness measurement is Mit
Made by utoyo, thickness measuring device Degimatic Ind
I went with icator. In the non-image plate made of the binder polymer of the present invention, ink stains were not detected by visual inspection, and after printing 30,000 copies, the plate was washed and dried, and changes in plate thickness before and after printing were hardly detected. On the other hand, in the plates of Comparative Examples 3 and 4, ink stains were observed from the middle.

[0029]

Example 7 On the support used in Example 4, a photosensitive solution having the following composition was applied with a blade coater, dried at 40 ° C. and photocured with an ultraviolet lamp to prepare an offset master plate. Then, the original plate was mounted on a plate making apparatus equipped with a laser diode having an emission center at 830 nm, and a test chart was printed. Thereafter, the image was mounted on the offset printing machine described in Example 4 as it was without any development or washing out operation, and printing was carried out in the same manner as in Example 4. After printing up to about 30,000 copies, ink stains on non-image areas were not observed, and good printed matter was obtained. Photosensitive solution composition 5 parts of binder polymer of Example 1 100 parts of 3,3'-dimethylbiphenyl-4,4'-diisocyanate and photothermal conversion dye kayasor
b CY-10 (trade name, manufactured by Nippon Kayaku Co., Ltd.) is dissolved and mixed in a solvent at a ratio of 2 parts, and then the dried solid is partially saponified P
Capsules made by crushing VA, water, ethanol with alumina balls 5 parts-PEG (Mn = 1000) 0.5 parts-Radical polymerization initiator 0.1 part used in Example 4-Water 11 parts-Ethanol 5 copies

[0030]

[Table 1]

[0031]

INDUSTRIAL APPLICABILITY The binder polymer of the present invention has excellent ink repellency and exhibits non-image performance comparable to that of an anodized aluminum support which is usually used as a non-image area in lithographic printing. Particularly, it exhibits good ink repellency against low-viscosity ink such as newspaper offset ink. In addition, since the polymer contains an acid amide group, it exhibits excellent wear resistance. In addition, it is easy to quantitatively introduce the addition-polymerizable unsaturated group and is excellent in practicality. By using the binder polymer of the present invention, a direct lithographic material which does not require any washing out and developing steps can be obtained, fluctuations in the image forming step can be suppressed to a minimum, and the quality of printed images can be easily controlled. It also contributes greatly to the environmental improvement brought about by the platemaking industry without the generation of industrial waste liquid.

Claims (8)

[Claims] 1. A reaction between a carboxyl group or a sulfonic acid group in a polymer composed of a monomer containing at least either a carboxyl group or a sulfonic acid group, and an addition polymerizable unsaturated group-containing isocyanato compound. A binder polymer for lithographic production, having a cross-linking property, in which a saturated group is introduced and a part of the remaining carboxyl group and sulfonic acid group is chlorinated with an alkali metal salt or an alkaline earth metal. 2. The number average molecular weight is 1.5 × 10 ³ to 30 ×.
The binder polymer for producing a lithographic plate according to claim 1, which is 10 ⁴ . 3. The binder polymer for producing a lithographic plate according to claim 1, wherein the introduction ratio of the addition-polymerizable unsaturated group is 3 to 30 mol% with respect to 100 mol of the polymer chain-constituting monomer. 4. An alkali metal salt of a carboxyl group or a sulfonic acid group or an alkaline earth metal having a chlorination ratio of a carboxyl group and // in a polymer before the addition-polymerizable unsaturated group is introduced.
The binder polymer for lithographic plate production according to claim 1, which is 30 equivalents or more and 97 equivalents or less based on 100 equivalents of all sulfonic acid groups. 5. The binder polymer for producing a lithographic plate according to claim 1, wherein the carboxyl group-containing monomer is at least one selected from acrylic acid, methacrylic acid and itaconic acid. 6. The sulfonic acid group-containing monomer is sulfoethyl acrylate, sulfoethyl methacrylate,
The binder polymer for producing a lithographic plate according to claim 1, which is at least one kind of acrylamidomethylpropanesulfonic acid and methacrylamidemethylpropanesulfonic acid. 7. The binder polymer for producing a lithographic plate according to claim 1, wherein the addition-polymerizable unsaturated group-containing isocyanato compound is at least one of 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate. 8. A lithographic plate material for dry process, which comprises the binder polymer for lithographic plate manufacturing according to claim 1.