KR20120120821A - Photo-sensitive composition for non-development negative thermal CTP printing - Google Patents

Abstract

PURPOSE: A non-development negative thermal CTP printing photo-sensitive composition is provided to converse operational costs by manufacturing a printing plate without an electrolytic polishing process and an anodizing process. CONSTITUTION: A non-development negative thermal CTP printing photo-sensitive composition includes a lipophilic resin, a hydrophilic resin, and a hydrophilic/lipophilic conversion resin. The hydrophilic/lipophilic conversion resin is converted from hydrophilicity to lipophilicity by light energy. The composition further includes an infrared ray absorption dye. The infrared ray absorption dye absorbs light energy to generate heat. The heat converts the hydrophilic/lipophilic conversion resin. The composition further includes a plate wear resistance enhancing resin. The plate wear resistance enhancing resin is a compound which blocking 3-15% pre-isocyanate with one or more compounds of phenol, ethyl acetoacetate, e-caprolactam, and methyl ethyl ketoxime.

Description

Photo-sensitive composition for non-development negative thermal CTP printing

The present invention relates to a photosensitive composition for developing negative thermal CTP printing, and more particularly, to a photosensitive composition for developing negative thermal CTP printing, which does not require a developing step of a non-wire portion and has excellent print resistance to condensed matter.

Thermal CTP, which is widely used in recent years, is a method of making a printing plate without a film by working with data unlike a PS, and has a merit of reducing time and cost of outputting a film by eliminating the process of forming an image using the film. In addition, it is possible to prevent defects that may occur when the film is formed on the PS plate and exposed, that is, the loss of dots from the baking process, image damage due to film damage, and foreign matter such as dust.

However, similar to PS, thermal CTP, which has such advantages, is developed with alkaline aqueous solution to distinguish fire and non-fired parts. In the process of developing alkaline solution, defects in dots may occur depending on fatigue, temperature, and development speed of alkaline aqueous solution. Alkaline aqueous solution used and water washed with water cause environmental problems as waste liquid, and waste water treatment facilities and costs are additionally required to treat the waste liquid. In order to solve this problem, in developing thermal CTP, a method of developing with rubber solution or water instead of alkaline aqueous solution has been mentioned in the patents of EP 1342568, PCT / EP 2005/052298, PCT / EP 2006/068303 and 10-2009-0050353. have. However, in order to use the patented method, exposure energy of about 2 to 3 times higher than that of the existing thermal CTP printing plate is required, which makes it difficult to use the existing thermal CTP setter. In addition, because the development with a rubber solution or water is small, but some waste fluid is generated, a separate development equipment is required for this, and defects in dots may occur during the development process.

In addition, in order to solve the above-mentioned problem, a method of developing an ordinary printing process by attaching an exposed printing plate to a printing machine without developing it is disclosed in PCT / EP 2006/068498, US 5,922,512, 6,723,495. Examining this method in detail, as the printing plate attached to the printing machine starts printing, the photosensitive composition layer of the non-firing portion is swollen by condensate supplied to the plate, and the swollen photosensitive composition layer is transferred to the printing blanket roller by the adhesion of ink. It is developed while being removed. However, in the above method, waste of printing paper may occur until normal printing according to adhesion of condensate and ink. In addition, there may still be a loss of dots due to development, a higher exposure energy than that used in the existing thermal CTP, and there is a limit to use in a clear room by using a photoinitiator or a diazo compound.

The present invention provides a photosensitive composition for printing negative thermal CTP printing to solve the above problems.

In order to solve the above problems, the present invention is a phenomenon-free negative thermal CTP photosensitive composition, the composition comprises a lipophilic resin, a hydrophilic resin and a hydrophilic / lipophilic conversion resin, wherein the hydrophilic / lipophilic conversion resin is irradiated It provides a non-developing negative thermal CTP photosensitive composition, characterized in that the conversion from hydrophilic to lipophilic by the light energy.

In one embodiment of the present invention, the composition further comprises an infrared absorbing dye, the infrared absorbing dye absorbs the irradiated light energy, generates heat, and the hydrophilic / lipophilic conversion resin according to the generated heat in the hydrophilic Converted to lipophilic.

In one embodiment of the present invention the composition further comprises an anti-friction improving reactive resin, wherein the anti-friction improving reactive resin is composed of toluene diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate and isophorone diisocyanate 3-15% free obtained by reacting one or two or more compounds selected from the group with one or two or more compounds selected from the group consisting of 2) ethylene glycol, propylene glycol, trimetholpropane and pentaerythritol Isocyanate is a compound obtained by blocking one or two or more compounds selected from the group consisting of phenol, ethyl acetoacetate, e-caprolactam, and methyl ethyl ketoxime.

In one embodiment of the present invention the composition further comprises one or more additives which may be selected from the group consisting of colorants, antifoams, leveling agents, slip agents, curing agents, adhesion promoters, wherein the composition of the composition A blend-free negative thermal CTP photosensitive composition characterized by following the following formula.

0.24 ≤ α ≤ 0.38

0.10 ≤ β ≤ 0.26

0.05 ≤ γ ≤ 0.15

0.03 ≤ δ ≤ 0.07

Wherein α = A / (A + B), β = C / (A + B), γ = D / (A + B + C), δ = E / (A + B + C), where A : Mass of lipophilic resin, B: mass of hydrophilic resin and hydrophilic / lipophilic conversion resin, C: mass resistance of reactive resin, D: mass of infrared absorbing dye, E: mass of additive)

In one embodiment of the present invention, the lipophilic resin is bisphenol A epoxy, bisphenol F epoxy, cycloaliphatic epoxy, novolak phenol type epoxy, novolak cresol type epoxy, cresol formaldehyde novolak, cresol phenol formaldehyde novo It consists of one or two or more monomers or polymer resins selected from the group consisting of locks, the weight average molecular weight of the selected resin is 500 to 600 for the monomer, 6,000 to 20,000 for the polymer resin, the acid value is 50 mg KOH / g or less

In one embodiment of the present invention, the hydrophilic resin is composed of one or two or more polymer resins selected from the group consisting of polyacrylic acid, polymethacrylic acid, methylvinyl ether maleic acid including carboxylic acid groups, and the weight average of the selected resin. It has a molecular weight of 200,000 to 1,500,000 and an acid value of 500 mg KOH / g or more.

In one embodiment of the present invention, the hydrophilic / lipophilic conversion resin is composed of one or two polymer resins selected from the group consisting of styrene-maleic anhydride and methylvinyl ether maleanhydride including anhydride group, , The weight average molecular weight of the selected resin is 200,000 ~ 1,500,000, the acid value is 500 mg KOH / g or more.

The present invention is also a printing method using the above-described negative thermal CTP photosensitive composition, the method for hydrophilic treatment of an aluminum support It provides a printing method using a no-defect negative thermal CTP photosensitive composition, characterized in that it does not include an electropolishing / anodization process.

The photosensitive composition for developing a negative thermal CTP printing according to the present invention is a plate making of a flat printing plate in which the developing process of the non-wire portion is completely omitted, and no developing waste solution is generated and there is no loss of dots that may occur in the developing process. In addition, electrolytic polishing and anodization processes can be omitted in the production of printed discs, which is economical in the process, and existing thermal CTP setters can be used as they are, and since they do not use photoinitiators or diazo compounds, they are free from restrictions that need to be used in clean rooms . Furthermore, there is an advantage that it is eco-friendly because the waste alkali solution discharged from the development process is not generated.

1 is a reaction scheme showing conversion of a hydrophilic resin according to the present invention to a lipophilic resin by laser (heat) exposure.
FIG. 2 is a view illustrating a mechanism in which a hydrophilic / lipophilic conversion resin is converted to a lipophilic resin by laser (heat) exposure and water or condensate absorption during non-exposure according to the present invention.
3 is a scheme of block isocyanate synthesis in accordance with one embodiment of the present invention.
4 is a diagram showing the mechanism by which blocked isocyanates according to the invention react under certain conditions.
5 is a step diagram illustrating a conventional printing process.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention can be implemented in various different forms, and is not limited to the embodiments described. In order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals in the drawings denote the same members.

Throughout the specification, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated.

The present invention uses a hydrophilic resin, a lipophilic resin and a hydrophilic / lipophilic conversion resin at the same time in order to solve the above problems. Herein, the hydrophilic / lipophilic conversion resin is a resin which is converted from hydrophilic to lipophilic resin by a heat applying means such as a laser, and the present invention uses a hydrophilic / lipophilic conversion resin together with a hydrophilic resin and a lipophilic resin in laser irradiation. The hydrophilic / lipophilic properties of the entire resin depended on the properties of the hydrophilic / lipophilic conversion resin. Thereby, although hydrophilic or lipophilic resins are present, the hydrophilic or lipophilic properties of the entire printing composition have been determined depending on whether or not the hydrophilic / lipophilic conversion resin is converted.

As used herein, the term lipophilic or hydrophilic is a relative expression, but a lipophilic resin should not contain a small amount or a carboxylic acid group that is a hydrophilic functional group in the resin, and means a resin having an acid value of 50 mg KOH / g or less. do. Thus, the lipophilic resin is selected from the group consisting of bisphenol A epoxy, bisphenol F epoxy, cycloaliphatic epoxy, novolak phenol type epoxy, novolac cresol type epoxy, cresol formaldehyde novolak, cresol phenol formaldehyde novolak It consists of a species or 2 or more types of monomers or polymer resins, and when the weight average molecular weight of the selected resin is a monomer, it is preferably 500 to 600, and in the case of a polymer resin, it is preferably 6,000 to 20,000.

In contrast, a hydrophilic resin means a resin containing at least one carboxylic acid group and having an acid value of at least 500 mg KOH / g. Such hydrophilic resins include polyacrylic acid, polymethacrylic acid and methylvinyl ether maleic acid resins.

1 is a reaction equation showing the conversion of a hydrophilic resin to a lipophilic resin by laser (heat) exposure according to the present invention, Figure 1 is to maintain a sufficient hydrophilicity in the non-fired portion, lipophilic by a catalyst or a curing agent in the fired portion Explain the mechanism that translates to.

Referring to FIG. 1, when only hydrophilic resins are used, a lot of energy is consumed in order to convert the hydrophilic resins into lipophilic. Therefore, a catalyst or a curing agent or the like caused a problem that must be accompanied.

In particular, the present inventors have found that hydrophilic resins containing carboxylic acid groups have excellent hydrophilic properties, but have disadvantageous disadvantages in terms of resistance to scratching and ink sensitivity, and to improve them, hydrophilic / lipophilic conversions including anhydride groups. Resin was used. In one embodiment of the present invention, the hydrophilic / lipophilic conversion resin should have an anhydride group which can be converted into a carboxylic acid group relatively easily with water, and the acid value should be 500 mg KOH / g or more. Such hydrophilic / lipophilic conversion resins include styrene-maleic anhydride and methylvinyl ether maleane-hydride resins. The hydrophilic and hydrophilic / lipophilic conversion resins according to the present invention are selected from the group consisting of the aforementioned resins. It is preferable that the weight average molecular weight of the resin selected from the species or two or more kinds of polymer resins is 200,000 to 1,500,000. The hydrophilic / lipophilic conversion resin maintains hydrophilicity when not exposed to heat by a laser or the like, but converts to lipophilic when exposed to heat. This is due to the property that the anhydride is converted to the carboxylic acid by the reaction with water, but converted to a hydrophobic functional group by the reduction reaction as a predetermined amount of heat is applied.

FIG. 2 is a view illustrating a mechanism in which a hydrophilic / lipophilic conversion resin is converted to a lipophilic resin by laser (heat) exposure and water or condensate absorption during non-exposure according to the present invention.

MEANS TO SOLVE THE PROBLEM This inventor follows the following formula for the relative content ratio of the mass of a hydrophilic resin, a hydrophilic / lipophilic conversion resin, and the mass of a lipophilic resin.

0.24 ≤ α ≤ 0.38

Where α = A / (A + B), where A is the lipophilic resin mass and B is the hydrophilic resin and the hydrophilic / lipophilic conversion resin mass

If the lipophilic resin mass exceeds the above-mentioned numerical range, problems such as non-linearity summing and the like occur. If the lipophilic resin mass is below the above-mentioned numerical range, the problem of inferior ink sensitivity of the main line portion occurs.

The photosensitive composition according to the present invention includes an anti-friction-improving reactive resin in addition to the above-mentioned resins, and the anti-friction-improving reactive resin comprises 1) toluene diisocyanate, hexamethylene diisocyanate, methylenediphenyl diisocyanate and isophorone diisocyanate. About 3 to 15% obtained by reacting one or two or more compounds selected from the group and 2) one or two or more compounds selected from the group consisting of ethylene glycol, propylene glycol, trimethol propane and pentaerythritol It is preferable that the preisocyanate is a substance in which isocyanate is blocked with a blocking agent, which is one or two or more compounds selected from the group consisting of phenol, ethyl acetoacetate, e-caprolactam, and methethyl ketoxime. Here, the pre-isocyanate is an isocyanate having the same reactivity, and the main purpose is to react with the carboxyl group or the epoxy group of the photosensitive liquid, as shown in FIG. At this time, when the isocyanate is less than 3%, the above effect is insignificant, and when the amount of the preisocyanate is 15% or more, the lipophilic portion of the caustic portion may be further improved, but the lipophilic quality of the non-caustic portion may also increase, thereby causing a scumming phenomenon. Where% is the percentage of preisocyanate functional group (NCO) weight relative to the total polymer weight.

3 is a scheme of block isocyanate synthesis in accordance with one embodiment of the present invention.

Referring to FIG. 3, a resin containing a pre-isocyanate group at both ends is reacted with a blocking agent such as phenol, ethyl acetoacetate, e-caprolactam, and metelethyl ketoxime to react a reactive isocyanate group (-NHCOO-R '). It can be seen that it is blocked. This suppresses the reactivity of the pre-isocyanate at room temperature, ensures the storage stability of the photosensitive composition, and also makes the reactivity at a specific temperature, leading to the improvement of the anti-friction resistance of the non-activated portion and the lipophilic portion of the active substance through the reaction. .

4 is a diagram showing the mechanism by which blocked isocyanates according to the invention react under certain conditions.

4, the blocking agent (R'-OH) is separated from the block isocyanate at a specific temperature, and then reacted with the separated preisocyanate and the carboxyl group of the hydrophilic resin, the epoxy group of the lipophilic resin, the curing agent reactor, and the like. At this time, the fire wire portion is added to the lipophilic, the non-fire line portion is improved in abrasion resistance.

In one embodiment of the present invention, the blending amount of the anti-friction improving reactive resin follows the following formula.

0.10 ≤ β ≤ 0.26

Β = C / (A + B) in the above formula, where A is a lipophilic resin mass, B is a hydrophilic resin and a hydrophilic / lipophilic conversion resin mass, and C is an anti-friction improving reactive resin mass.

If β exceeds the numerical range, problems such as scumming and the like occur in the non-wire portion, and if it is less than the numerical range, it is difficult to expect improvement in the breaking force.

The non-developed negative thermal CTP printed disc photosensitive composition according to the present invention absorbs infrared rays in the wavelength range of 700 to 1,200 nm in the irradiated laser beam to generate an exothermic phenomenon, and thus uses the hydrophilic / lipophilic conversion resin used. Infrared absorption dye which converts from hydrophilic to lipophilic, raises the crosslinking density of a lipophilic resin, and raises the lipophilic property of a caustic part. Therefore, the infrared absorbing dye according to the present invention is preferably a pigment or a dye having light absorption in the infrared region of 700 ~ 1,200nm, Indole-based, Cyanine-based, Phthalocyanine-based dyes do. Commercially available infrared absorbing dyes include IR-140, IR-746, IR-768 perchlorate, IR-755 chloride, IR-780 iodide, IR-780 perchlorate, IR-783, IR- from Sigma-Aldrich. 786 perchlorate, IR-786, IR-792 perchlorate, IR-797 chloride, IR-797 perchlorate, IR-806, IR-813 chloride, IR-813 perchlorate, IR-820 and FEW S0094, ADS 830AT, 830WS and PCAS IR-22B and IR-23B.

The compounding ratio of the said infrared absorbing dye follows the following formula.

0.05 ≤ γ ≤ 0.15

(Wherein γ = D / (A + B + C), A: lipophilic resin mass, B: hydrophilic resin and hydrophilic / lipophilic conversion resin mass, C: anti-friction improvement reactive resin mass, D: infrared absorption Dye amount)

If the infrared absorbing dye is less than the above numerical range, it is difficult to expect the lipophilic of the caustic portion due to the conversion of sufficient hydrophilic / lipophilic conversion resin, and if it exceeds the above numerical range, it is more advantageous for the lipophilic of the caustic portion, but infrared absorption Given that dyes are very expensive, it is difficult to secure economic feasibility.

The sensitizing composition according to the present invention may include an additive which may be selected from one or more of a colorant, an antifoaming agent, a leveling agent, a slipping agent, a curing agent, an adhesion promoter, and the like, and the amount thereof is usually 5 to 10 relative to the stock solution. The weight% is suitable, and preferably the compounding ratio should be determined according to the following formula.

0.03 ≤ δ ≤ 0.07

(Wherein δ = E / (A + B + C), A: lipophilic resin mass, B: hydrophilic resin and hydrophilic / lipophilic conversion resin mass, C: anti-friction improvement reactive resin mass, E: additive mass being)

Hereinafter, the present invention will be described in more detail with reference to Examples and drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the scope of the present invention is not limited thereto.

Example

The test-free negative thermal CTP printed disc fabrication and test procedure for confirming the performance of the photosensitive composition according to the present invention are as follows.

First, an aluminum disc having a purity of 99.5% and a thickness of 0.3 mm was alkali degreased and then prepared by applying / drying the photosensitive composition of Table 1 below. The fabricated printed disc was used to form a line image using Creo's Trendsetter 800 (thermal CTP setter).

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Suzy Lipophilic resin 26 17 26 35 9 52 9 Hydrophilic resins and
Hydrophilic / lipophilic conversion resin 52 52 43 52 52 17 60 Improved Immunity
Reactive resin 9 18 18 0 26 18 18 Infrared absorbing dye 9 9 9 9 9 9 9 additive 4 4 4 4 4 4 4 combination
parameter alpha 0.33 0.25 0.38 0.40 0.15 0.75 0.13 β 0.12 0.26 0.26 0.00 0.43 0.26 0.26 γ 0.10 0.10 0.10 0.10 0.10 0.10 0.10 δ 0.05 0.05 0.05 0.05 0.05 0.05 0.05

Experimental Example

An aqueous solution in which 10% by weight of isopropanol was mixed as a condensate was used as a condensate on the printed plate on which the image was formed, and the ink sensitivity of the wire part and the non-firing part scum phenomenon were confirmed. The measurement of the printing resistance of the photosensitive layer attached to the printing plate is immersed in the condensate at 20 ° C., then about 500g of additional rods covered with pure cotton are placed on the immersed printing plate and rubbed 15 times. The measurement was repeated in units of 10 minutes to record the time at which the photosensitive layer began to peel off and the results are shown in [Table 2].

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Caustic ink sensitivity ◎ ◎ ◎ ◎ △ ◎ △ Non-fireline Summing ◎ ◎ ○ ◎ ○ X ◎ Strength 60 minutes 120 minutes 140 minutes 10 minutes 40 minutes 100 minutes 20 minutes

◎: Good, ○: Normal, △: Less than, X: Bad

Referring to the results of Table 2, when using the photosensitive composition according to the present invention, it can be seen that all the improvement effect occurs in the line portion ink sensitivity, non-line portion scum improvement, the printing resistance.

The production process of the existing printing plate is produced through a 19 step process as shown in FIG. However, the printing plate including the photosensitive composition according to the present invention does not require the developing process of the non-wire portion because the photosensitive layer has an adhesive force and hydrophilicity suitable for printing, thereby increasing the uniform surface and surface area, and thus maintainability and non-sensitization treatment. The electrolytic polishing process for enhancing the adhesion between the photoresist and the aluminum support by enhancing the effect, and the anodizing process for improving the strength of the support and making the hydrophilic layer by making the aluminum oxide film after polishing can be reduced or omitted. Accordingly, the printing plate production process of the present invention can reduce the entire printing process to 10 steps by omitting the process included in the dotted line block in FIG. Therefore, compared with the existing production process, the production equipment cost and electricity consumption can be reduced by more than 50%, and the production speed can also be more than doubled compared with the existing production process. In addition, the electropolishing and anodization processes can be reduced or omitted, eliminating the need for expensive, high-purity aluminum that is easy to polish. In other words, it is also possible to apply synthetic resin plates or other metallic materials. This indicates that the cost reduction effect is significant compared with the prior art.

In particular, the demand for cheap, stable, and environmentally friendly printing discs is steadily increasing due to the high price of printing discs in the global printing market. In accordance with the present invention, waste liquid does not occur due to the omission of the developing process. It is eco-friendly and requires no facilities and costs for waste treatment, and can use existing thermal CTP setter equipment as it is, and can produce inexpensive printing discs.

Claims (8)

A no-degradation negative thermal CTP photosensitive composition, wherein the composition is
A lipophilic resin, a hydrophilic resin and a hydrophilic / lipophilic conversion resin, wherein the hydrophilic / lipophilic conversion resin is characterized by a light-free negative thermal CTP photosensitive, characterized in that the conversion from hydrophilic to lipophilic by irradiated light energy. Composition. The method of claim 1,
The composition further includes an infrared absorbing dye, wherein the infrared absorbing dye absorbs the irradiated light energy and generates heat, and the hydrophilic / lipophilic conversion resin is converted from hydrophilic to lipophilic according to the generated heat. No-development negative thermal CTP photosensitive composition. The method of claim 2,
The composition further comprises an anti-friction improving reactive resin, wherein the anti-friction improving reactive resin is one or two selected from the group consisting of toluene diisocyanate, hexamethylene diisocyanate, methylenediphenyl diisocyanate and isophorone diisocyanate 2 to 15% of the preisocyanate obtained by reacting at least one compound with 2 or more compounds selected from the group consisting of 2) ethylene glycol, propylene glycol, trimethol propane and pentaerythritol; and phenol and ethyl acetoacetate. , N-negative thermal CTP photosensitive composition, characterized in that the compound blocked by one or two or more compounds selected from the group consisting of e-caprolactam and methyl ethyl ketoxim. The method of claim 3, wherein
The composition further comprises one or more additives that may be selected from the group consisting of colorants, antifoams, leveling agents, slip agents, curing agents, adhesion promoters, wherein the blending ratio of the composition is according to the following formula: A non-developing negative thermal CTP photosensitive composition.
0.24 ≤ α ≤ 0.38
0.10 ≤ β ≤ 0.26
0.05 ≤ γ ≤ 0.15
0.03 ≤ δ ≤ 0.07
Wherein α = A / (A + B), β = C / (A + B), γ = D / (A + B + C), δ = E / (A + B + C), where A : Mass of lipophilic resin, B: mass of hydrophilic resin and hydrophilic / lipophilic conversion resin, C: mass resistance of reactive resin, D: mass of infrared absorbing dye, E: mass of additive) The method according to any one of claims 1 to 4,
The lipophilic resin is selected from the group consisting of bisphenol A epoxy, bisphenol F epoxy, cycloaliphatic epoxy, novolak phenol type epoxy, novolak cresol type epoxy, cresol formaldehyde novolak, cresol phenol formaldehyde novolak It consists of a species or two or more monomers or polymer resins, the weight average molecular weight of the selected resin is 500 to 600 when the monomer, 6,000 to 20,000 when the polymer resin, the acid value is 50 mg KOH / g or less No development negative thermal CTP photosensitive composition. The method according to any one of claims 1 to 4,
The hydrophilic resin is composed of one or two or more polymer resins selected from the group consisting of polyacrylic acid, polymethacrylic acid, methylvinyl ether maleic acid including a carboxylic acid group, the weight average molecular weight of the selected resin is 200,000 ~ 1,500,000, An undeveloped negative thermal CTP photosensitive composition, characterized by an acid value of at least 500 mg KOH / g. The method according to any one of claims 1 to 4,
The hydrophilic / lipophilic conversion resin is composed of one or two polymer resins selected from the group consisting of styrene-maleic anhydride and methyl vinyl ether maleanhydride including anhydride group, and the weight average molecular weight of the selected resin. The non-developing negative thermal CTP photosensitive composition, which is 200,000 to 1,500,000 and has an acid value of 500 mg KOH / g or more. The printing method using the no-defect negative thermal CTP photosensitive composition according to any one of claims 1 to 4, wherein the method is for hydrophilic treatment of an aluminum support. A printing method using a non-developing negative thermal CTP photosensitive composition, characterized in that it does not include an electropolishing / anodic oxidation process.

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