CN102236254B - radiation sensitive composition - Google Patents

Abstract

The invention provides a radiation-sensitive composition, which comprises modified film-forming resin, copolymerization macromolecules, an acid generator, a radiation-absorbing dye and the like. The composition is coated on a proper substrate, and an image can be obtained after baking, exposure and development. The image has good hardness, abrasion resistance, adhesion and printing resistance, and can increase the development latitude.

Description

radiation sensitive composition

technical field

The present invention relates to a radiation-sensitive composition for lithographic printing plates. the

Background technique

The characteristic of lithography is that the inked image area (image area) and the non-inked non-image area on the lithography are on the same plane. Wherein, the image area is lipophilic and hydrophobic, and the non-image area is hydrophilic and oleophobic. The operation method of lithographic printing is to use the immiscible characteristics of oil (oily substance or ink) and water to first apply water to the printing plate, so that the non-image area forms a hydrophilic and oleophobic water film, and then ink the printing plate , so that the ink is partially attached to the image area, and under the action of printing pressure, the graphics on the printing plate are transferred to the surface of paper or other substrates through the rubber cylinder. Typically the ink is transferred to a blanket known as an intermediate material, and then the ink is transferred to the surface of the material on which the image is to be reproduced, such as paper, cloth, plastic or metal. the

The manufacturing method of the pre-coated photosensitive lithographic printing plate (Pre-Sensitized Plate, PS plate) is roughly that the surface of an aluminum plate is first electrolyzed or ground to form a plurality of grains required for printing, and then the photosensitive A radiation-sensitive or heat-sensitive composition is coated on the grains of the aluminum plate to form a radiation-sensitive coating, and the radiation-sensitive coating is baked and cured. Then, through a negative film with a predetermined image and text, the image and text on the negative film are transferred to the radiation-sensitive coating by exposure and development, so as to make a printing plate for printing the image and text on the document . the

In recent years, digitization technology that uses computers to process and output image information has been widely used, and various corresponding new image output methods have been put into practical use. In lithographic printing, if the production of the negative can be omitted, the digital pattern of the computer is directly transferred to the radiation-sensitive coating through the exposure and development process to make a printing plate for printing images and text on the document, making the plate-making operation easier. It is greatly simplified, which can greatly increase the printing rate and reduce the cost. This technology is called Computer To Plate (CTP), and how to obtain a printing plate suitable for this technology has become an important issue. the

After exposure of the radiation-sensitive composition coated on the surface of an aluminum plate used for lithography, its exposed portion becomes alkali-soluble, thereby removing it during the development process. This type of plate is called a positive photosensitive plate; otherwise, the exposed part will harden (curing) and become alkali-insoluble, and it is called a negative photosensitive plate. In both cases, the remaining image area is ink-absorbent or lipophilic, while the non-image area is water-absorbent or hydrophilic. The positive or negative working of the photosensitive plate depends on the radiation sensitive composition coated on the surface of the aluminum plate. the

The above-mentioned radiation-sensitive composition is mainly composed of the following materials: radiation-absorbing dye (sensitizer or thermal agent), acid generator, phenolic resin (film-forming agent), copolymerized polymer, solvent, and other additives . the

Prior art, such as U.S. Patent No. 6,063,544 discloses a coating coated with a mixture of phenolic resin (novolac) or cresol-formaldehyde resin (cresol-formaldehyde) or polyhydroxystyrene resin (poly(hydroxystyrene)) and infrared absorbing dye Positive photosensitive plate. In addition, U.S. Patent Nos. 5,372,907, 5,372,915, 5,340,699, and 5,491,046 are coated with a mixture of novolac type phenolic resin, cresol type phenolic resin, infrared absorbing dyes or pigments, and latent Bronstedacid. When these plates are exposed to infrared radiation, the latent protic acid decomposes to form a species that promotes the crosslinking of different types of phenolic resins (such as novolac and cresol), hardening the mixture in the exposed areas. Further heating of the exposed printing plate further hardens the exposed coating making it insoluble in an alkaline developer, however the unexposed areas remain soluble in the developer. U.S. Patent No. 5,919,601 discloses a radiation-sensitive composition composed of a binder resin (binder resin), a crosslinking agent, a thermal-activated acid generator (thermal-activated acid generator) and an infrared absorber. After the composition is exposed to infrared rays , the acid generator decomposes to release an acid, and the acid causes a crosslinking reaction of the binder resin by the crosslinking agent. the

The common disadvantage of the above-mentioned technologies is that after the printing plate is developed, the displayed image area often lacks integrity and cannot be used for long-term effective printing, so that the definition and printing quality of the printed image produced are poor. the

However, under the premise that printers are constantly required to improve plate-making efficiency and printing quality to enhance industrial competitiveness, the sensitivity of radiation-sensitive coatings on printing plates is required to be faster, that is, the energy required for exposure is lower. or a shorter exposure time. In addition, the exposed part needs to be more easily washed off by the developer during development, and the unexposed part needs to be more resistant to immersion and scouring of the developer, that is, the temperature, concentration, and soaking and scouring time of the developer during development, etc. Conditions are more forgiving. At the same time, good resolution, inking properties, and abrasion resistance of the finished radiation sensitive coating must also be maintained. In addition, the adhesion between the radiation-sensitive coating and the aluminum plate needs to be better. the

Many patents put forward different views and methods to solve the different requirements of the printing industry, such as U.S. Patent No. 7,425,402 and No. 7,455,949 for the phenolic resin or copolymerized polymer in the radiation-sensitive coating formulation, the phenolic monomeric unit (phenolic monomeric) in its structure unit), the imide or thioimide functional group is bonded to the carbon atom on the phenol group, which can improve the chemical resistance of the radiation-sensitive coating. resistance). U.S. Patent No. 7,458,320 is aimed at phenolic resins or copolymerized polymers in radiation-sensitive coating formulations. The phenolic monomer units in the structure are modified, and the imide functional group is bonded to the hydrogen atom or phenolic group on the phenolic group. The hydrogen atom of the hydroxyl group on the base can improve the chemical resistance and development latitude of the radiation-sensitive coating. U.S. Patent No. 7,563,556 describes the modification of phenolic monomer units. The structure is shown in (A). The radiation-sensitive coating prepared by this structure can obtain a cleaner pattern during the development process, and less residue remains in the pattern. . the

Structural formula (A)

Wherein, R is H, D ₁ or D ₂ ; R ₁ is H or C1-C2 alkyl; n is 1, 2 or 3; R ₂ is H or C1-C6 alkyl or alkoxy.

As mentioned above, most of the patents describe how to improve the characteristics of the radiation-sensitive coating on the printing plate after exposure and development, and seldom describe the latitude of the development process of the radiation-sensitive coating. Therefore, the present invention mainly tries to find other methods that can improve the development method for process tolerance. the

US Patent Nos. 5,770,750, 6,166,151 and 6,291,077 describe methods for modifying phenolic resins, and the modified phenolic resins are used in the coating industry. In this modification method, the phenolic resin reacts with a lactone structure, as shown in the following reaction formula (B). the

Reaction (B)

Contents of the invention

The object of the present invention is to provide a radiation-sensitive composition, which can be coated on a suitable substrate, such as a printing plate, and after baking, exposure and development, an image can be obtained, and the image has good hardness, Abrasion resistance, adhesion, printing capacity, and can increase the development tolerance value, which can greatly improve product yield and quality. the

In order to achieve the above object, the present invention provides a radiation-sensitive composition, which contains a film-forming resin modified by the reaction of the general formula (I) phenolic resin and the general formula (II) lactone structure. The radiation-sensitive composition is applied on a substrate to form an image layer, which can effectively improve the developing latitude without affecting the hardness, abrasion resistance and adhesion of the radiation-sensitive coating. the

General formula (I)

Wherein Q can be H, C1-C2 alkyl; D can be H, OH, C1-C8 alkyl, cycloalkyl, alkoxy or phenyl, p=1, 2 or 3, n≥1. the

General formula (II)

Where x=an integer of 0-17, R ₃ , R ₄ , and R ₅ can be H, C1-C20 alkyl, cycloalkyl, alkoxy or phenyl, respectively.

The radiation-sensitive composition of the present invention may further comprise a radiation-absorbing dye, a copolymerized polymer, a solvent, a surfactant, a colorant, a wetting agent, an acid generator, or a combination thereof. the

The effect that the radiation-sensitive composition of the present invention produces is as follows: the present invention has used the composition of the film-forming resin that contains phenolic resin or polyhydroxy (methyl) styrene resin and lactone structural reaction modification for the first time, will contain this film-forming resin The composition is coated on a suitable substrate, and after baking, exposure and development, an image can be obtained. The image has good hardness, wear resistance, adhesion, printing durability, and can increase the development tolerance value. Can greatly improve product yield and quality. This is because when the phenolic resin reacts with the lactone structure, because of the different chain lengths from the hydroxyl group on the phenolic resin to the main chain, it should have different effects in the development process and alkaline developer, which will increase the development latitude . the

Detailed ways

The invention provides a radiation-sensitive composition, which can form an image layer on a substrate, and the composition can be used as a coating of positive and negative photosensitive plates. Composition of the present invention is the film-forming resin that contains general formula (I) phenolic resin and general formula (II) lactone structure reaction modification, and its structure is as follows:

General formula (I)

Wherein Q can be H, C1-C2 alkyl; D can be H, OH, C1-C8 alkyl, cycloalkyl, alkoxy or phenyl; p=1, 2 or 3; and

General formula (II)

Where x=an integer of 0-17; R ₃ , R ₄ , and R ₅ can be H, C1-C20 alkyl, cycloalkyl, alkoxy or phenyl, respectively.

The structure of the film-forming resin modified by the reaction of phenolic resin and lactone is as follows:

Wherein, Q can be H, C1～C2 alkyl; D can be H, OH, C1～C8 alkyl, cycloalkyl, alkoxy or phenyl; p=0, 1, 2 or 3; r is an integer from 1 to 4, and p+r=4; x=an integer from 0 to 17; R ₃ , R ₄ , and R ₅ can be H, C1-C20 alkyl, cycloalkyl, alkoxy or phenyl.

Where E can be H, CH ₃ ; s is an integer of 1 to 5; t is an integer, and s+t=5; x=an integer of 0 to 17; R ₃ , R ₄ , and R ₅ can be H and C1 respectively ~C20 alkyl, cycloalkyl, alkoxy or phenyl.

The radiation-sensitive composition can be composed of 30-95% by weight of film-forming resin (film-forming agent), the film-forming resin is modified by reaction with phenolic resin and lactone, 4-65% by weight of copolymerized polymer, 0.1-45% by weight % of radiation absorbing dye, 0.1-15% by weight of acid generator. The compositions claimed in the present invention may also comprise solvents and additives. the

The present invention also provides a method for producing an image. The method includes: (1) coating an imaging layer on a substrate, and the imaging layer is a film-forming resin modified by a reaction between a phenolic resin and a lactone, and a copolymerized polymer. , radiation-absorbing dyes, and acid generators. This imaging layer can also comprise solvent and additive; (II) make this imaging layer dry properly; (III) make the imaging area of this imaging layer be exposed to the energy source that can emit fully, for example can be wavelength at 320nm～750nm UV/ a Vis beam or an IR beam with a wavelength of 750 nm to 1350 nm; and (IV) contacting the imaging area with a developing solution to remove the exposed portion from the substrate. the

The phenolic resin suitable for the present invention can be phenol, o-cresol, m-cresol, p-cresol, 2-naphthol, phenol derivatives or a mixture of two or more of the above with formaldehyde, acetaldehyde, other Aldehyde condensation reaction products such as aliphatic or aromatic aldehydes. The phenolic resin preferably has a weight average molecular weight in the range of 300-400,000. the

The lactones suitable for the present invention may be propiolactone, butyrolactone, valerolactone, caprolactone and their lactone derivatives. the

The copolymerization macromolecule that is applicable to the present invention, its monomer can be (meth) acrylic acid monomer, as methyl methacrylate (MMA), methacrylic acid (MAA), (meth) acrylate lauryl, (methacrylic acid) base) isostearyl acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc., styrene and its derivatives, such as α-methylstyrene, 4-hydroxystyrene, 4-hydroxymethylstyrene, halogen-containing (methyl)styrene, etc., maleic anhydride, propylene Nitrile (acrylonitrile AN) and nitrogen-substituted maleimide monomer (N-substituted maleimide monomer, wherein nitrogen-substituted maleimide monomer can be N-phenylmaleimide (N-phenylmaleimide PMI), p-hydroxyphenylmaleimide (4-hydroxyphenylmaleimide), N-2,3 dimethylphenylmaleimide (N-(2,3-dimethylphenyl)Maleimide, etc., the above-mentioned Monomers are synthesized according to different compositions and ratios, and are applied to photosensitive coatings. 

The radiation-absorbing dyes suitable for the present invention generally include photosensitive dyes and thermosensitive dyes. Photosensitizing dyes are mainly esterified condensates of 1,2-naphthoquinonediazo-4-sulfonic acid chloride or 1,2-naphthoquinonediazo-5-sulfonic acid chloride and polyhydroxy compounds. Thermosensitive dyes are mainly dyes with an absorption wavelength of 700-900nm, such as cyanine dyes, polymethine dyes, naphthoquinone dyes, phthalocyanine dyes, anthracene dyes, and polymethine dyes. Anthraquinone dyes or indoaniline metal complex dyes are the main ones. the

Acid generators suitable for use in the present invention are those which generate protic acids when exposed to heat or light energy in the infrared region of the spectrum. The generated protonic acid can photodecompose the polymer in the exposed area of the positive photosensitive material. Such materials, ie, compounds that generate protic acids by thermochemistry, are disclosed, for example, in US Patent No. 5,466,557, which is hereby incorporated by reference. Particularly useful compounds are halogenated compounds such as halogenated triazines (or S-triazine derivatives), halogenated 2-pyrones, halogenated oxazoles, halogenated oxadiazoles and halogenated thiazoles. These compounds generally have polyhalomethyl groups such as trihalomethyl groups that can generate desirable hydrohalic acids when they are heated by infrared radiation. The most commonly available acid generators may be selected from various trichloromethyltriazines, which may advantageously be selected from, but not limited to, tris-trichloromethyltriazines, di-trimethylphenyl Triazines, bis-trichloromethyl o- or p-methoxyphenyl triazines, bis-trichloromethyl(3,5-dimethoxy)phenyl triazines, di- Trichloromethylnaphthyl triazine, bis-trichloromethyl 5-methoxynaphthyl triazine, bis-trichloromethyl styryl triazine, bis-trichloromethyl styrene Triazine and bis-trichloromethyl (4-methoxy) styryl triazine, etc. the

The solvent used in the present invention can be selected from, for example, alcohols, esters, ketones, ethers, amides, aromatics and mixtures thereof. Especially 1-methoxy-2-ethanol, 1-methoxy-2-propanol, ethyl glycol acetate, ethyl acetate, acetone, methyl ethyl ketone, diisobutyl ketone, methyl iso Butyl ketone, cyclohexanone, toluene, xylene, n-propanol, isopropanol, tetrahydrofuran, butyrolactone, methyl lactate, dimethylamide and mixtures thereof. the

The additives used in the present invention can be additives such as surfactants, colorants and wetting agents. The use of the coloring agent is mainly for the purpose of easily distinguishing the image after the printing plate is developed. The coloring agent suitable for the present invention can be an oil-soluble dye or a basic dye. Such as Crystal Violet, Malachite Green, Victoria Blue, Methylene Blue, Ethyl Violet, Oil Blue 603/613, Rodin Ming B (Rhodamine B) and other one or their mixture. the

The present invention is described in more detail below by several embodiments:

<Example 1> film-forming resin modification

With 40 grams of phenolic resin-Rezicure5200 (high-purity m-cresol phenolic resin, produced by SpecialChem), 12 grams of phenolic resin- SD-1508 (bisphenol-based phenolic resin, produced by Hexion), 10.0 grams of caprolactone and 200 grams of xylene were placed in a 500ml four-necked reaction flask, and the four-necked flask was respectively connected with stirring blades, a thermometer, nitrogen and reflux Tube, heat up to 120°C until the phenolic resin is completely dissolved, add 2 grams of stannous octoate (T-9 catalyst) (0.1%), then add 2 grams of sulfuric acid (0.1%), heat up to 130°C and keep warm for reaction. After the reaction is completed, the xylene is drained to obtain the modified film-forming resin (product number N-1).

<Example 2> film-forming resin modification

Roughly the same as the modification method of Example 1, the difference is that 8.0 grams of caprolactone is used, and the product number of this modified film-forming resin is N-2. the

<Example 3> film-forming resin modification

Roughly the same as the modification method of Example 1, the difference is that 6.0 grams of caprolactone is used, and the product number of this modified film-forming resin is N-3. the

<Example 4> film-forming resin modification

Roughly the same as the modification method of Example 1, the difference is that 7.5 grams of butyrolactone is used, and the product number of this modified film-forming resin is N-4. the

<Example 5> film-forming resin modification

Roughly the same as the modification method of Example 1, the difference is that 6.0 grams of butyrolactone is used, and the product number of this modified film-forming resin is N-5. the

<Example 6> film-forming resin modification

Roughly the same as the modification method of Example 1, the difference is that 4.5 grams of butyrolactone is used, and the product number of this modified film-forming resin is N-6. the

<Example 7> copolymerization polymer synthesis

35 grams of N-phenylmaleimide (PMI), 30 grams of methyl methacrylate (MMA), 35 grams of acrylonitrile (AN), 1 gram of initiator (azobisisobutyronitrile (AIBN)) and 200 grams of solvent (dimethylformamide, DMF) were placed in a 500ml four-necked reaction flask, and the four-necked flask was respectively connected with a stirring blade, a thermometer, nitrogen and a reflux tube, and the temperature was controlled at 70°C for 24 hours. After the reaction was completed, , lower the temperature and pour the reaction solution into 6kg of water, the copolymerized polymer will be precipitated in the water, filter and dry to obtain the copolymerized polymer (sample code P-1). Other copolymerized polymers with different compositions can also be obtained by the above method. the

<Example 8> Preparation of heat-sensitive radiation-sensitive composition and CTP printing plate

20 grams of phenolic resin-Rezicure5200, 6 grams of phenolic resin- SD-1508, 9.0 grams of copolymerized polymer (sample code P-1), 0.8 grams of radiation-absorbing dye-cyanine dye IR dye23b[PCAS] (the dye that will react under the IR wavelength, produced by PCAS company) , 0.24 gram of bis-trichloromethyl (4-methoxy) styryl triazine, 0.5 gram of colorant-Victoria blue, 0.5 gram of colorant-crystal violet lactone, 6 ml of solvent-ethyl acetate Esters, and 104 grams of solvent-ethyl glycol acetate, were stirred until completely dissolved to obtain the heat-sensitive radiation-sensitive composition of this embodiment.

In addition, prepare a piece of aluminum plate that has undergone hydrophilic treatment, and coat the above-mentioned heat-sensitive radiation-sensitive composition on the aluminum plate with a film thickness of 1.8g/m ² . After drying at 100°C for 4 minutes, and then After aging at 50°C for 24 hours, a positive heat-sensitive CTP printing plate can be obtained.

<Example 9> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

SD-1508，以26克改性成膜树脂(N-1)取代。  Roughly the same as the positive thermal CTP printing plate of Example 8, the difference is that 20 grams of phenolic resin-Rezicure5200 and 6 grams of phenolic resin-

SD-1508, replaced with 26 grams of modified film-forming resin (N-1).

<Example 10> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

It is roughly the same as the positive heat-sensitive CTP printing plate of Example 9, except that the modified film-forming resin whose sample number is N-2 is used. the

<Example 11> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

It is roughly the same as the positive heat-sensitive CTP printing plate of Example 9, except that the modified film-forming resin whose sample number is N-3 is used. the

<Example 12> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

It is roughly the same as the positive thermosensitive CTP printing plate of Example 9, except that the modified film-forming resin whose sample number is N-4 is used. the

<Example 13> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

It is roughly the same as the positive heat-sensitive CTP printing plate of Example 9, except that the modified film-forming resin whose sample number is N-5 is used. the

<Example 14> preparation of thermosensitive radiation-sensitive composition and CTP printing plate

It is roughly the same as the positive heat-sensitive CTP printing plate of Example 9, except that the modified film-forming resin whose sample number is N-6 is used. the

The positive heat-sensitive CTP printing plates prepared in the above-mentioned Examples 8 to 14 were tested for exposure and development. The developing solution of developing test is Kodak premium (produced by Kodak Company), the temperature of developing solution is 23 ℃, developing time is 30 seconds, iCPlate2[X-rite] printing plate measuring instrument (produced by X-Rite Company) carries out 50% Dot rendering test. The results are summarized in Table 1 below. the

Table 1

No./Energy Value (mJ/cm ² ) 146 155 165 176 188 203 220 Example 8 52.5 52.0 51.3 50.4 49.5 49.1 48.0 Example 9 52.1 51.5 49.8 50.4 49.4 48.6 47.9 Example 10 52.3 51.2 51.4 49.9 49.2 48.0 47.5 Example 11 52.1 51.5 51.1 49.5 49.4 49.8 47.9 Example 12 52.8 51.5 49.8 49.5 49.2 49.8 47.5 Example 13 52.1 51.2 51.4 49.9 50.1 48.6 47.5 Example 14 53.0 52.5 51.1 49.5 50.1 48.0 48.5

Measure the thinning difference (i.e. the ratio of reduction before and after the photosensitive layer) of Example 8 to Example 14 with X-rite 528 chromaticity analysis instrument (produced by X-Rite Company), and drop to the bottom of the plate with alcohol without color change As a benchmark, measure the corresponding clear point (clean point). Usually the photosensitive layer contains pigments, such as blue pigments. If the photosensitive layer remains on the substrate, alcohol can dissolve the pigment in the photosensitive layer, that is, measure the substrate through alcohol Whether there is any unsensitized photosensitive layer remaining on the surface. In addition, because finger contact is the main cause of peeling off or scratches on the printed contact surface, the surface scratch test of the product is carried out by the hardness test, and the surface hardness of the product is judged by the standard pencil hardness. Use 3M#610 adhesive tape, stick the tape on the print, press it firmly, no air will remain in the joint between the tape and the print, after pasting, let it stand for one minute, tear off the tape after one minute, if the print If it is in a complete state, then proceed to OK, and if the print has been torn off, proceed to NG. Using a friction-resistant machine, the wet test method is rubbed back and forth 100 times to observe whether the surface is worn or not. There are three grades, namely poor, normal and good. Finally, under accelerated abrasion printing conditions, the substrates were tested for yield of images of commercially acceptable quality. The results are summarized in Table 2 below. the

Table 2

serial number Thinning difference (%) clarification point Hardness (H) then wear resistance Durability Example 8 0.11 146mJ/cm ² 4H NG Difference 45000 Example 9 0.13 146mJ/cm ² ≥4H OK good 120000 Example 10 0.12 146mJ/cm ² ≥4H OK good 110000 Example 11 0.13 146mJ/cm ² ≥4H OK good 130000 Example 12 0.12 146mJ/cm ² ≥4H OK good 110000 Example 13 0.12 146mJ/cm ² ≥4H OK good 120000 Example 14 0.12 146mJ/cm ² ≥4H OK good 110000

The developing solution used in the development test is Kodak premium, the temperature of the developing solution is 23°C, and the developing time is 45 seconds. The iCPlate2[X-rite] measuring instrument conducts a 50% dot rendering test and measures it with an X-rite 528 chromaticity analysis instrument The difference in thinning from Example 8 to Example 14, and the corresponding clarification points were measured based on the fact that there was no color change when the alcohol was dripped onto the bottom of the plate. The results are summarized in Table 3 below. the

table 3

No./Energy Value (mJ/cm ² ) clarification point 130 146 155 165 176 188 203 Thinning difference value (%) Example 8 130 46.2 45.7 45.0 44.2 43.5 42.8 42.1 0.32 Example 9 130 49.8 48.7 48.1 47.3 46.2 45.6 45.1 0.21 Example 10 130 50.2 49.5 48.9 48.2 47.4 46.9 45.9 0.19 Example 11 130 50.7 50.1 49.7 48.5 48.0 47.4 47.0 0.19 Example 12 130 49.9 49.4 48.7 47.8 47.2 46.6 46.3 0.20 Example 13 130 50.0 49.1 48.5 48.0 47.6 47.3 46.9 0.19 Example 14 130 49.7 48.7 48.3 47.6 47.2 46.6 46.1 0.18

The developing solution used in the development test is Kodak premium, the temperature of the developing solution is 25°C, and the developing time is 30 seconds. The iCPlate2[X-rite] measuring instrument conducts a 50% dot image test and measures it with an X-rite 528 chromaticity analysis instrument The difference in thinning from Example 8 to Example 14, and based on the fact that there is no color change when the alcohol drips onto the bottom of the plate, is used to measure the corresponding clearing point. The results are summarized in Table 4 below. the

Table 4

No./Energy Value (mJ/cm ² ) clarification point 130 146 155 165 176 188 203 Thinning difference (%) Example 8 130 46.0 45.3 45.1 44.5 43.4 42.8 42.3 0.35 Example 9 130 49.5 48.3 48.4 47.1 46.0 45.7 45.2 0.22 Example 10 130 49.9 49.3 48.8 48.3 47.3 46.5 45.4 0.18 Example 11 130 50.5 50.2 49.6 48.6 48.1 47.4 47.1 0.19 Example 12 130 50.1 49.7 48.8 47.7 47.1 46.8 46.2 0.21 Example 13 130 50.2 49.6 48.4 48.1 47.5 47.0 46.4 0.20 Example 14 130 49.6 48.5 48.2 47.9 47.3 46.9 46.3 0.17

From the above data, it can be found that the positive-type heat-sensitive CTP printing plate introduced with modified film-forming resin of the present invention has high sensitivity and good alkali resistance. After prolonging the developing time or increasing the developing temperature, there is little difference in the performance of 50% dots, which shows that it can effectively improve Development latitude. Therefore, the introduction of modified film-forming resin can increase the sensitivity, hardness, adhesion, wear resistance and printing durability of the printing plate, and the product yield and quality can be improved through this method. the

Claims (4)

1. A radiation-sensitive composition, which is applied on a substrate to form an image layer, is characterized in that: the composition is a film-forming resin containing general formula (I) phenolic resin and general formula (II) lactone structure reaction modification , whose structure is as follows: General formula (I)

Wherein Q is H, C1-C2 alkyl; D is H, OH, C1-C8 alkyl, cycloalkyl, alkoxy or phenyl; p=1, 2 or 3; and General formula (II)

Wherein x=an integer of 0-17; R ₃ , R ₄ , and R ₅ are H, C1-C20 alkyl, cycloalkyl, alkoxy or phenyl, respectively. 2. radiation-sensitive composition as claimed in claim 1, this film-forming resin is the resin after the reaction modification of phenolic resin and lactone, and its structure is as follows:

Wherein, Q is H, C1～C2 alkyl; D is H, OH, C1～C8 alkyl, cycloalkyl, alkoxy or phenyl; p=0, 1, 2 or 3; r is 1 An integer of ∼4, and p+r=4; x=an integer of 0∼17; R ₃ , R ₄ , and R ₅ are H, C1∼C20 alkyl, cycloalkyl, alkoxy or phenyl, respectively. 3. The radiation-sensitive composition of claim 1, further comprising a radiation-absorbing dye, a copolymeric polymer, a solvent, a surfactant, a colorant, a wetting agent, an acid generator, or a combination thereof. 4. The radiation-sensitive composition of claim 1, wherein the substrate is a printing plate.