CN1603956A - Imaging composition for heat-sensitive CTP plates, acid-generating source used in the composition and preparation thereof - Google Patents

Abstract

This invention provides a high sensitivity image forming composition used in heat sensitive CTP plate and its acid generating source preparation method. The said composition comprises the following countered by weight: 1 to 20 percent of heat acid generating source; 50 to90 percent of filming resin; 1 to 20 percent of cross linker; 1 to 10 percent of light to heat translation substance; 0.2 to 2 percent of color dye; and 10 to 30 percent of solvent, wherein the said weight percent values are based on the composition total mass.

Description

Imaging composition for heat-sensitive CTP plates, acid-generating source used in the composition and preparation thereof

technical field

The invention belongs to the technical field of synthesis, preparation and application of optical information recording materials. More specifically, the present invention relates to a photosensitive composition sensitive to ultraviolet light and infrared light for printing lithography, an acid-generating source for the composition and its preparation, a method for obtaining different types of CTP printing plates with the above composition, and The resulting CTP plate.

technical background

In the 1990s, Kodak took the lead in inventing thermal digital plate-making plates, referred to as thermal CTP plates (US 5340699, US 5491046, US 5466557). This kind of plate uses phenol resin as film-forming resin, uses methylol phenol resin (resol) as crosslinking agent, uses iodonium salt or trichloromethyl triazine as photoacid source, and uses benzindole A cyanine dye (which can absorb 830nm near-infrared light) is used as a photothermal conversion substance, and a colored background dye is added to form an imaging composition for a negative heat-crosslinking thermosensitive CTP plate. When the infrared laser (830nm) is controlled by the computer to perform imaging scanning exposure on the plate, the scanning part of the infrared absorbing dye absorbs the 830nm infrared light and converts it into heat energy, causing the temperature of the scanned part to rise above the threshold temperature, resulting in photoacid production The thermal source decomposes to produce acid to form a latent image; then, preheat the plate between 110-130°C to fully cross-link and cure the latent image, and then enter the developer for development, and the unscanned and cured part is After washing away, a negative thermal crosslinking thermal CTP printing plate is obtained. This can be said to be the most original background technology of hundreds of thermal CTP invention patents since 1995. However, there is a preheating process before developing in this technology, which not only requires expensive preheating and cooling equipment, but also prolongs the process and reduces the plate making speed. Afterwards, people put forward the scheme of thermal CTP plate making without preheating, and dozens of patent applications were filed by KPG Company, Agfa Company, Fujifilm Company, Mitsubishi Chemical Company, etc. The feature of this technology is that it omits the preheating process in the plate-making process of the thermally cross-linked heat-sensitive CTP plate of the negative image, and obtains the positive image printing plate. Some of these technologies complete imaging plate-making based on physical changes, while others complete imaging plate-making based on chemical changes. Based on the imaging process of physical changes, the composition of the imaging composition is simple, and the stability of the plate is good. However, the dissolution contrast in the developer before and after thermal scanning is small, and the imaging quality is not high. Although the imaging method based on chemical changes has overcome the disadvantages of the imaging method based on physical changes, it is currently being widely used. However, this printing plate is different from the preheated negative printing plate in terms of resolution, dot reduction and printing durability. Compared with cross-linked plates, there is still a certain gap (Yu Shangxian, Yang Jinrui: thermal CTP technology and thermal imaging materials, "Printing Today", No.9, 2002).

At the Drupa Printing Exhibition in 2000, Japan's Mitsubishi Chemical Company exhibited a negative image without preheating thermal crosslinking thermal CTP plates. Afterwards, some patents were published in the world. Generally, resins capable of acid-initiated polymerization or free-radical-initiated polymerization are selected as film-forming resins, and photoacid-generating sources and thermal initiators, as well as infrared absorbing dyes are added as photothermal conversion substances. to form an imaging composition. When the infrared light scans, the photothermal conversion substance absorbs the light and converts into heat, and the heat causes the acid generation source or the thermal initiator to decompose, generating protons or free radicals, which in turn causes cationic polymerization or free radical polymerization, and polymerizes the scanned part Cures to an imaged area that is insoluble in the developer. However, some of these plates have problems in storage stability, some are difficult to develop in dilute alkaline water to obtain clear images, and some have low printing durability after imaging. Therefore, so far, the industrialization and commercialization of this plate material have not performed well.

Contents of the invention

In view of the aforementioned technical background, the inventors of the present invention are based on the fact that 2,1,4-diazonaphthoquinone sulfonate compounds are prone to sulfonate decomposition to produce sulfonic acid after ultraviolet light exposure (G.Buhr, H.Lenz and S. Scheler, Image Reversal Resists for g-line Exposure: Chemistry and Lithography, J. Photopolym. Sci. Technol., 1989, 2(3): 417-428) and the high-sensitivity negative image heat exchange that Mitsubishi Chemical Corporation once applied for The patent (Mitsubishi Chemical Co., Ltd., JP-11-119428, 11-24248, etc., photosensitive composition and photosensitive lithographic printing plate) of the combined thermosensitive CTP plate uses a new type of photoacid source in the photosensitive composition wherein Photothermal acid generation source is replaced, and industrialized phenolic resin is used as film-forming resin to adjust the composition ratio of photosensitive composition, and to cooperate with different plate-making processes, such as the method of first using near-ultraviolet light for full exposure, and then performing infrared laser scanning , to obtain different types of CTP printing plates, which have very good application prospects as negative thermal cross-linking thermal CTP plates and negative thermal cross-linking thermal CTP plates without preheating. Compared with the invention of the high-sensitivity heat-sensitive CTP plate material of Mitsubishi Chemical Corporation (Japanese Patent Laid-Open Ping-11-119428), it has more outstanding advantages. Based on this, the present invention has been accomplished.

The object of the present invention is to provide a novel imaging composition for thermosensitive CTP plates, which comprises film-forming resin, acid-generating source, crosslinking agent, light-to-heat conversion substance, colored background dye and solvent, which can be obtained by using the composition High-sensitivity, good-resolution, high-running negative heat-crosslinking thermal CTP plates, negative heat-crosslinking thermal CTP plates without preheating, and positive heat-sensitive CTP plates without preheating .

Another object of the present invention is to provide a novel acid-generating source compound used in the above-mentioned imaging composition for thermosensitive CTP plates and a preparation method thereof.

Another object of the present invention is to provide a method for preparing a CTP plate from the imaging composition for a CTP plate of the present invention.

Another object of the present invention is to provide a CTP plate made from the imaging composition for CTP plate of the present invention.

Therefore, the present invention provides a kind of imaging composition for novel thermosensitive CTP plate material on the one hand, comprises following component:

1) 1-20% by weight of photothermal acid generating source;

2) 50-90% by weight of film-forming resin;

3) 1-20% by weight of crosslinking agent;

4) 1-10% by weight of light-to-heat conversion substances;

5) 0.2-2% by weight of colored background dye; and

6) The solid content of the composition is 10-30% by weight of solvent, wherein the weight percentage is based on the total solid mass of the composition.

Another aspect of the present invention provides a novel acid-generating source compound represented by the following general formula:

General formula 1 General formula 2 General formula 3

或 ，R₁为H或C₁-C₄烷基，n为2-5，2n＝m+p，m≥p，且p不等于0。where R is

or , R ₁ is H or C ₁ -C ₄ alkyl, n is 2-5, 2n=m+p, m≥p, and p is not equal to 0.

Another aspect of the present invention provides a preparation method for the above-mentioned novel acid-generating source compound, comprising combining 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride with substances selected from N-hydroxyimides, polyhydroxy The phenolic compound reacts with the esterification or grafting matrix of novolac resin with a weight average molecular weight of 2000-4000 and isolates the obtained product.

Another aspect of the present invention provides a method for preparing a CTP plate from the above-mentioned imaging composition for a thermosensitive CTP plate and the CTP plate obtained therefrom.

Detailed description of the invention

The acid-generating source compound used in the imaging composition for heat-sensitive CTP plates of the present invention is a novel acid-generating source compound shown in the following general formula:

General formula 1 General formula 2 General formula 3

，R₁为H或C₁-C₄烷基，n为2-5，2n＝m+p，m≥p，且p不等于0。where R is or

, R ₁ is H or C ₁ -C ₄ alkyl, n is 2-5, 2n=m+p, m≥p, and p is not equal to 0.

The key technology of the present invention lies in the design, synthesis and application of the novel photothermal acid generator and its application in the photosensitive composition. Of course, conventional photoacid generators such as the photoacid generator 3,5-bistrichloromethyl-1-p-methoxystyryl triazine compound used in the patent of Mitsubishi Chemical Corporation and the diphenyliodonium salt used by Kodak Undoubtedly, the acid source can be used as the photoacid generator in the imaging composition of the present invention to partially replace the novel photothermal acid generator. These conventional photoacid generators are generally used in an amount ranging from 1 to 10% by weight based on the total solid mass of the imaging composition. However, only using the photoacid generation source common to these heat-sensitive CTP plates can only obtain a negative heat-crosslinking heat-sensitive CTP plate with preheating, and it is difficult to obtain a positive or negative heat-sensitive CTP plate without preheating . The innovation of the present invention is: firstly, based on 2,1,4-diazonaphthoquinone sulfonate after ultraviolet light irradiation, the diazonaphthoquinone group decomposes and isomerizes, and after becoming an indenic acid structure, the sulfonate The ester group of the ester is also easy to decompose to produce sulfonic acid, which has been reported in the past. Our valuable idea is that the sulfonic acid ester that becomes indenic acid structure should be more easily decomposed to generate sulfonic acid than 2,1,5-diazonaphthoquinone sulfonic acid ester under the action of heat. Second, we affirm that this photothermal acid-generating source can undergo a process of changing from a solvent-repellent to a solubilizer before and after the action of light and heat, and has a very large dissolution contrast in the developer, which is very conducive to the formation of a positive image. Thermal CTP plates without preheating. Thirdly, we borrowed from the structure of phthalimide and naphthalimide, which is easy to undergo a certain alkali-water insolubilization process with phenolic resin under the action of heat, and introduced this structure into sulfonate, It forms a composite cross-linking curing system with hexamethoxymethyl melamine. Therefore, this sulfonic acid ester is used not only as an acid-generating source, but also as a solvent-repellent/solvent-promoting agent, and as an auxiliary cross-linking curing agent, and successfully obtained a negative-image non-preheating thermal cross-linking thermal CTP plate. Finally, we also found that the corresponding p-toluenesulfonate had similar properties.

The above-mentioned novel acid-generating source compound can be obtained by including 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride and selected from N-hydroxy imides, polyhydric phenolic compounds and weight average molecular weight of 2000 -4000 novolak resin esterification or grafting precursor reaction and separation of the resulting product prepared.

There are many esterification precursors required in 2,1,4-diazonaphthoquinone sulfonate or p-toluenesulfonate esters. As mentioned above, there are three types of esterification precursors used in the present invention: ①N-hydroxyacyl Amines such as N-hydroxyphthalimide, N-hydroxynaphthalimide, N-hydroxytetrahydrophthalimide, N-hydroxynorbornenedicarboximide , N-hydroxysuccinimide, etc. Considering its solvent properties, ease of reaction, and imaging properties, N-hydroxyphthalimide is recommended. ② Polyhydric phenolic compounds obtained by condensation or addition of resorcinol, such as condensation products of resorcinol and acetone, condensation products of resorcinol and cyclohexanone, resorcinol and benzil acid Condensation products, adducts of resorcinol and rosin, adducts of resorcinol and tung oil or tung acid, and urushiol, etc. When these polyhydric phenolic derivatives are esterified with 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride, it is not necessary to be 100% esterified like the first class of substances, only ≥50% of the phenolic hydroxyl ester can be converted. ③ Novolac resins with a weight average molecular weight of 2000-4000, such as m-cresol-formaldehyde resin, o-cresol-formaldehyde resin, phenol-m-cresol-formaldehyde resin, phenol-p-cresol-formaldehyde resin, etc., these matrix resins The esterification rate of the phenolic hydroxyl group can be between 20-50%. From the perspective of the solvent performance and imaging performance of the synthesized esterified product, it is preferred to use the condensation product of N-hydroxyphthalimide, resorcinol and acetone or cyclohexanone, and some low molecular weight novolac resin. The procedure for synthesizing the photothermal acid generation source of the present invention by reacting the first to third types of esterification precursors above with 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride can refer to the applicant's September 3, 2003 The Chinese patent application Shen Qing 03156178.0 filed on 12th, the entire disclosure content of this application is hereby cited as a reference. For example, the above-mentioned first to third types of esterified precursors can be mixed with 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride in one or more solvents selected from acetone, dioxane, and DMF In the process, triethylamine is used as a neutralizing agent or a catalyst in equimolar or slightly excess amounts of 2,1,4-diazonaphthoquinonesulfonyl chloride or p-toluenesulfonyl chloride, and the catalyst is added dropwise between 0-40°C, thereby Synthesizing 2,1,4-diazonaphthoquinone sulfonate or p-toluene sulfonate, the mole amount of the esterification reagent is 50-100% of the total mole number of phenolic hydroxyl groups in the graft matrix. The separation and purification method is to inject the reaction liquid into distilled water more than 10 times, precipitate the reaction product, filter, wash with water repeatedly, and dry the product at 45-50°C. It should be emphasized that when synthesizing 2,1,4-diazonaphthoquinonesulfonyloxyphthalimide, DMF or a composite solvent containing DMF must be used for the reaction. 2,1,4-diazonaphthoquinone sulfonyloxyphthalimide (PAG-1) represented by general formula 1, 2,1,4-diazonaphthoquinone sulfonic acid represented by general formula 2 Ester (PAG-2) and 2,1,4-diazonaphthoquinone sulfonate (PAG-3) represented by general formula 3 are three kinds of acid generating sources recommended for use in the present invention.

PAG-1(PH-NAS-4) PAG-2(RA-NAS-4) PAG-3(BTB-NAS-4)

R ₁ is H or C ₁ -C ₄ alkyl, n is 2-5, 2n=m+p, m≥p, and p is not equal to 0.

where R is

In the imaging composition of the present invention, the total content of the above-mentioned photothermal acid generator and optional conventional photoacid generator is 1-20% by weight, preferably 2-10% by weight, based on the total solid mass of the composition.

为5000-20000的聚对羟基苯乙烯、聚邻羟基苯乙烯或它们的改性产物。还有重均分子量 为3000-8000， 在3-10之间的苯酚-甲醛树脂、间甲酚-甲醛树脂、邻甲酚-甲醛树脂、苯酚-间甲酚-甲醛树脂、苯酚-邻甲酚-甲醛树脂、苯酚-对甲酚-甲醛树脂、苯酚-叔丁基酚-甲醛树脂、苯酚-间甲酚-对甲酚-甲醛树脂、间甲酚-对甲酚-甲醛树脂和间甲酚-叔丁基酚-甲醛树脂等。它们在成像组成物中的含量一般为组合物固体总质量的50-90％重量，优选为60-80％重量。若用量太大，则成像组合物的阻溶能力弱，对碱显影液的抵抗能力差，显影过程中留膜率低，不仅影响图象分辨率和网点再现性，也会降低所涂印版的耐印率。反之，用量太少，交联剂和其他阻溶组分的用量必然增加，虽然感度有可能提高(对阴图版)，但是它的显影能力下降，易于产生留底、残脏现象，也会降低图象的分辨率和网点再现性。对于阳图无预热CTP版材而言，成膜线型酚树脂最好在主链中或侧链上含有一定量的酸解活性醚键。对于阴图热敏CTP版而言，应选用碱溶性高且分子量较大的线型酚树脂。The film-forming resin in the imaging composition of the present invention generally selects novolac resin, such as weight average molecular weight

5000-20000 poly-p-hydroxystyrene, poly-ortho-hydroxystyrene or their modified products. weight average molecular weight for 3000-8000, Between 3-10 phenol-formaldehyde resin, m-cresol-formaldehyde resin, o-cresol-formaldehyde resin, phenol-m-cresol-formaldehyde resin, phenol-o-cresol-formaldehyde resin, phenol-p-cresol- Formaldehyde resin, phenol-tert-butylphenol-formaldehyde resin, phenol-m-cresol-p-cresol-formaldehyde resin, m-cresol-p-cresol-formaldehyde resin and m-cresol-tert-butylphenol-formaldehyde resin, etc. Their content in the imaging composition is generally 50-90% by weight of the total solid mass of the composition, preferably 60-80% by weight. If the amount is too large, the imaging composition will have weak solvent resistance, poor resistance to alkaline developer, and low film retention rate during development, which will not only affect image resolution and dot reproducibility, but also reduce the coated printing plate. The printing run rate. Conversely, if the amount is too small, the amount of cross-linking agent and other solvent-resistant components will inevitably increase. Although the sensitivity may be improved (for negative plates), its developing ability will decrease, and it will easily cause bottoming and residual dirt. Image resolution and dot reproducibility. For positive CTP plates without preheating, the film-forming novolac resin preferably contains a certain amount of acidolysis active ether bonds in the main chain or on the side chain. For negative thermal CTP plates, novolac resins with high alkali solubility and high molecular weight should be selected.

There are many options for the cross-linking agent in the imaging composition of the present invention, for example, methylolated novolac resin, methylolated poly-p-hydroxystyrene, methylolated polyphenol compound can be used. It may also be methylolated melamine, methoxymethylated novolac resin, methoxymethylated polypara-hydroxystyrene, methoxymethylated polyphenol compound, methoxymethylated melamine, and the like. Due to the strong polarity of methylolated phenolic resins or polyphenolic compounds, methylolated melamine, their resistance to alkaline solutions is poor, and their thermal stability in imaging compositions is not very good; in addition , methoxymethylated phenolic resin and polyphenolic compound, the cross-linking reaction activity that takes place under the action of acid is relatively low, and imaging speed is insufficient, so the present invention recommends the use of hexamethoxymethylmelamine whose methoxylation ratio is as high as possible, The etherification rate of its methoxylation is preferably about 95%.

The cross-linking agent should be used in the imaging composition in an amount of 1-20% by weight, preferably 5-15% by weight, based on the total solid mass of the composition. As an imaging composition for a positive thermal CTP plate without preheating, the amount of crosslinking agent should be below 5%, and as an imaging composition for negative thermal crosslinking thermal CTP plate, the amount of crosslinking agent should be 5-15%. %. If the amount is too large, it will be difficult to develop, easy to cause residual dirt, and affect the resolution of the printing plate. If the dosage is too small, the cross-linking and curing will be insufficient, which will not only reduce the sensitivity, but also affect the printing durability of the printing plate.

The synthesis method of the hexamethoxymethyl melamine with high etherification rate used in the present invention can refer to the synthesis method of polyalkoxymethyl melamine in the amino resin of traditional paints and coatings. Only need to increase the consumption of methyl alcohol here, so that obtain the hexamethoxymethyl melamine that etherification rate is more than 90%.

The light-to-heat conversion substance in the imaging composition of the present invention is a commonly used infrared absorbing dye, which can be the benzoindole series cyanine dye, step cyanine dye and various λ _max =825- Infrared absorbing dye at 840nm (in imaging systems). In order to use conventional solvents for PS plates, PS-101 or PS-102 of Nippon Kayaku Co., Ltd. can be used; in order to reduce the cost of plates, NK-2014 or NK-2268 commercialized by Japan Linyuan Co., Ltd. can also be used, and similar products from other companies. They are generally used in an amount of 1-10% by weight, preferably 4-8% by weight, of the total solid mass of the composition in the heat-sensitive composition. If the dosage is too small, the thermal sensitivity is low, and the image quality is poor; if the dosage is too large, since the infrared absorbing dye is an alkali-insoluble substance, it will be difficult to develop, and the cost of the plate will be greatly increased.

The colored background dyes in the imaging composition of the present invention can be selected from various background dyes of traditional PS plates and thermosensitive CTP plates. Such as oil soluble blue, basic brilliant blue, Victoria pure blue, indigo, methyl violet, crystal violet, malachite green. In addition, some auxiliary dyes can also be added, such as Sudan black, methyl orange, eosin, dimethyl yellow, fluorescent yellow, etc. The amount of the background dye added in the photosensitive composition is generally 0.2-2% by weight, preferably 0.5-1.5% by weight, based on the total mass of the solid. The amount of auxiliary dye added is 20-80% of the main background dye.

The solvent in the imaging composition of the present invention can be selected traditional PS plate or CTP plate imaging composition solvent, such as cyclohexanone, methyl ethyl ketone, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, γ-butyrolactone, ethyl lactate, acetic acid Butyl ester, dioxane, tetrahydrofuran, trichloroethylene, chloroform, dichloromethane, etc. They can be used alone or in combination of two or more. When using general-purpose infrared absorbing dyes, the main solvent should be cyclohexanone or methyl ethyl ketone, and other solvents can be used as auxiliary solvents. When using Nippon Kayaku’s PS-101 or PS-102, the main solvent should be ethylene glycol monoethyl ether or propylene glycol monoethyl ether, and ketone solvents, ester solvents or organic chlorides can be used as auxiliary solvents. The amount of solvent used in the imaging composition depends on the viscosity and solid content of the prepared thermal imaging liquid. Generally, the solid content of the imaging liquid is 10-30%, so the content of the solvent in the imaging liquid should be 70-90%. The amount of auxiliary solvent added is generally 10-15% of the main solvent.

The present invention also provides a set of methods for obtaining different types of heat-sensitive CTP printing plates by using the aforementioned imaging composition in conjunction with different plate-making processes, which include: (1) preparing a negative thermal crosslinking type (usually referring to preheating, the same below) The method for heat-sensitive CTP printing plate, comprises using thermal imaging composition of the present invention to be coated on the aluminum plate base that has been processed and goes out heat-sensitive CTP original plate, passes through the Quansheng 3244 heat-sensitive CTP plate making of Creo Company (Canada Ottawa) Machine for infrared laser scanning, then preheat at 120-130°C for about 1 minute, and develop in a lithographic developing machine equipped with an alkaline developer. The thermal CTP platesetter that can be selected in this process method can also be a platesetter with an infrared laser output of 830nm provided by any other manufacturer. (2) A method for preparing a negative image without preheating heat-crosslinking heat-sensitive CTP printing plate, including coating a heat-sensitive CTP original plate with the aforementioned imaging composition, and then first fully exposing it with a near-ultraviolet light source with an output wavelength of 320-450nm , the exposure amount is controlled at 150-250mJ/cm ² , and then infrared laser scanning is carried out by the thermal plate-making machine, and it is directly developed in the above-mentioned developing machine without preheating process. The biggest feature of this method is that the heat-sensitive CTP negative printing plate is produced by using the quick and easy near-ultraviolet pre-exposure instead of the preheating and cooling process in method (1). (3) The method for preparing a positive-working heat-sensitive CTP printing plate without preheating includes using the imaging composition of the present invention (wherein the acid-generating source is selected from the photothermal acid-generating source of general formula 3 and selects the upper limit consumption, and the cross-linking agent selects The lower limit dosage and the film-forming novolac resin with high acidolysis activity should be used as much as possible) to coat the heat-sensitive CTP original plate. After infrared laser scanning by the heat-sensitive plate-making machine, it will directly enter the developing solution that is weaker than the aforementioned developing solution for development. .

In addition, polyphenol compounds with high crosslinking activity represented by the following formulas 4-6 can be added to the CTP imaging composition with or without preheating for negative thermal crosslinking. Under the action of acid, these compounds can increase the crosslinking rate and efficiency of hexamethoxymethylmelamine, thereby improving the sensitivity of the thermal imaging composition. Another main function of these polyphenolic compounds is to increase the developing speed and imaging contrast of the film layer of the imaging composition, and to avoid residue residue. Wherein formula 4 is resorcinol acetone (RA condensate produced by Tiancheng Chemical Company, Weihai Economic and Technological Development Zone, Shandong); The BZR condensate produced); formula 6 is a rosin resorcinol adduct (RR adduct produced by Tiancheng Chemical Company, Weihai Economic and Technological Development Zone, Shandong). In addition, there are tung oil resorcinol adducts (TOR adducts), tung acid resorcinol adducts (TAR adducts) and resorcinol condensation products produced by Tiancheng Chemical Company in Weihai Economic and Technological Development Zone, Shandong Province. Cyclohexanone (RCH condensate), etc.

Resorcinol acetone (RA condensate)                                                        

(4)

            

     Rosin resorcinol adduct (RR adduct)

(6)

In order to improve the sensitivity of the thermally cross-linked CTP plate without preheating in the negative image, a small amount of azide compound can also be added to the imaging composition of the present invention. These azide compounds can be azidopyrene, azidobenzoic acid, azidobenzaldehyde, azidochalcone, bisazide stilbene and its sulfonate, bisazide benzylcyclohexanone, bisazide benzyl Condensates of methylenecyclohexanone, azidobenzaldehyde and polyvinyl alcohol, etc. Wherein the 2,6-bis-azidobenzylidene cyclohexanone (BAC-H of Japan Toyo Synthetic Industry Co., Ltd.) shown in the following formula 7 and formula 8 and 2,6-bis-azidobenzylidene methylcyclohexanone (Japan BAC-M) of Toyo Gosei Kogyo Co., Ltd. is a compound having high photothermal decomposition efficiency and high crosslinking activity, and thus is preferably used in the present invention. In particular, they can be used in conjunction with the aforementioned active phenolic compounds to obtain a satisfactory color (orange-red) crosslinking effect.

2,6-Bisazidobenzylidenecyclohexanone

(7) (8)

Example

The present invention will be described in detail below with reference to examples.

The following preparation examples 1-3 illustrate the key components of the present invention-the synthesis method of the novel photoacid generating source shown in the general formula 1, the general formula 2 and the general formula 3.

Preparation Example 1

The method for synthesizing 2,1,4-diazonaphthoquinone sulfonyloxyphthalimide ester with N-hydroxyphthalimide and 2,1,4-diazonaphthoquinone sulfonyl chloride

Get 8.15g (0.05mol) of N-hydroxyphthalimide, 13.4g (0.05mol) of 2,1,4-diazonaphthoquinonesulfonyl chloride, add 50ml N,N-dimethylformamide and 60ml Acetone, stirred to dissolve. Raise the temperature of the system to 30°C, drop a drop of 5% dilute sulfuric acid into the system, and then slowly add 5% tris Ethylamine, when the pH value of the system is about 7, pour the reaction solution into distilled water 10 times its volume, and precipitate the product. After soaking for several hours, filter it with suction, and then dry it at about 40°C to obtain a yellow powder solid , and the yield was 84%.

Preparation Example 2

Method for synthesizing 2,1,4-diazonaphthoquinone sulfonate by condensate of resorcinol and acetone and 2,1,4-diazonaphthoquinone sulfonyl chloride

Get 15g resorcinol acetone (0.05mol) produced by Tiancheng Chemical Company, Weihai Economic and Technological Development Zone, Shandong, 26.8g (0.1mol) 2,1,4-diazonaphthoquinone sulfonyl chloride, be dissolved in 300ml acetone, stir dissolve. The temperature of the system was raised to 35°C, and 58.3 g of 10% Na ₂ CO ₃ aqueous solution (equivalent to 0.055 mol) was added dropwise through the dropping funnel within 1 hour. After the dropwise addition, keep the reaction at 35-40°C for 1 hour, then pour the reaction liquid into 10 times the amount of distilled water, adjust the pH value to 6.5 with dilute HCl, precipitate the product, filter, and rinse with distilled water for 3 times , and dried at 40-50°C to obtain a yellow powder solid product with a yield of 91%.

Preparation Example 3

Synthesis of 2,1,4-diazonaphthoquinone sulfonate from novolak resin and 2,1,4-diazonaphthoquinone sulfonyl chloride

Take 15 g of novolac resin BTB-24 (Tiancheng Chemical Company, Chenghai Economic and Technological Development Zone, Shandong), 10 g of 2,1,4-diazonaphthoquinone sulfonyl chloride, add 130 ml of acetone, and stir to dissolve. Raise the temperature of the system to 35°C, drop a drop of 5% dilute sulfuric acid into the system, and then slowly add 5% triethylamine in excess of 2,1,4-diazonaphthoquinonesulfonyl chloride in 30 minutes, When the pH value of the system is about 7, pour the reaction solution into distilled water 10 times its volume, soak for several hours, filter it with suction, and dry it at about 40°C to obtain a yellow powder solid. The yield was 98%.

The following examples are used to illustrate the preparation of the imaging composition of the present invention, wherein embodiment 1-6 is the embodiment of negative image thermal crosslinking type thermosensitive CTP plate imaging liquid, and embodiment 7-12 is negative image without preheating heat Examples of cross-linked CTP plate imaging fluid, and examples 13-16 are positive image thermal CTP without preheating

Examples of plate imaging solutions.

Example 1

Take the BTB-26 m-cresol-formaldehyde resin produced by Tiancheng Chemical Company in Weihai Economic and Technological Development Zone, Shandong $(\stackrel{\‾}{m_w}=4000,\stackrel{\‾}{m_{\mathrm{no}}}=1100)$ 70g, 4g of PAG-1 obtained in preparation example 3, 3,5-bistrichloromethyl-1-p-methoxystyryl triazine (S-triazine produced by Institute of Applied Chemistry, Beijing Normal University) 5g, 15g of hexamethoxymethylated melamine (more than 95% methoxylation percentage) produced by Beijing Normal University Institute of Applied Chemistry, 5g of infrared absorbing dye NK-2014 produced by Japan Linyuan Company, Victoria Pure Blue produced by Japan Hodogaya Chemical Company BOH 1g, cyclohexanone 900g.

First, dissolve the infrared absorbing dye NK-2014 in cyclohexanone, then add the triazine compound, after it is completely dissolved, then add the phenolic resin and other components, and heat to 30-40°C to dissolve it completely if necessary. Then filter elements with 10 μm, 5 μm, and 0.5 μm pore sizes were used for three-stage filtration to obtain thermal CTP-sensitive thermal imaging liquid TCL-1.

Example 2

Take the poly(p-hydroxystyrene) VP-8000 produced by Japan Soda Co., Ltd. $({\stackrel{\‾}{m}}_w=8000,\stackrel{\‾}{m_w}/\stackrel{\‾}{m_{\mathrm{no}}}=1.12)$ 70g, RA condensate 4g produced by Tiancheng Chemical Company, Chenghai Economic and Technological Development Zone, Shandong, 1-p-methoxynaphthyl-3,5-bistrichloromethyl triazine (S-triazine produced by Experimental Chemical Plant of Beijing Normal University) 4g, PAG-1 1g of the gained PAG-1 of Preparation Example 1, Japan Mitsui Amino Resin Company Cymel-300 (methoxyl etherification rate ≥ 95%) 12.5g, NK-2014 infrared absorbing dye 7.5g of Example 1, Example 1 Victoria pure blue 0.5g, dimethyl yellow (Beijing Chemical Reagent Factory) 0.5g, cyclohexanone 900g, with the dissolution, preparation and filtration method of embodiment 1, obtain thermosensitive CTP thermal imaging liquid TCL-2.

Example 3

Get 65g of m-cresol-formaldehyde resin (softening point 110-115°C) produced by Liaoning Benxi Institute of Light Industry, prepare PAG-24g obtained in Example 2, 3,5-bistrichloromethyl-1- P-methoxystyryl triazine 5g, BTC-101 (hexamethoxymethylated melamine) 12.5g and RCH condensate 5g produced by Tiancheng Chemical Company, Weihai Economic and Technological Development Zone, Shandong, S 0094 infrared absorption of German FEW CHEMICALS company Dye 7.5g, Basic Brilliant Blue (Beijing Chemical Reagent Factory) 0.5g, the dimethyl yellow 0.5g of embodiment 2, cyclohexanone 900g, obtain thermosensitive CTP thermosensitive with the dissolving of embodiment 1, preparation and filtration method Imaging fluid TCL-3.

Example 4

Get BTB-26 phenolic resin (Shandong Weihai Economic and Technological Development Zone Tiancheng Chemical Company, softening point 110-115 ℃) 70g, prepare the PAG-3 4g of embodiment 3 gained, the 3 of embodiment 1, the 5-two trichloromethyl -1-p-methoxy styryl triazine 5g, BTC-101 12.5g of embodiment 3, S 0094 infrared absorbing dye 7.5g of embodiment 3, basic brilliant blue 1g of embodiment 3, cyclohexanone 900g , using the dissolution, preparation and filtration methods of Example 1 to obtain thermosensitive CTP thermal imaging fluid TCL-4.

Example 5

Get Shandong Weihai Economic and Technological Development Zone Tiancheng Chemical Company to produce BTB-134 phenolic resin (terpolymer) 70g, PAG-2 5g of preparation embodiment 2 gained, tribromomethyl phenyl sulfone (Chiba University, Japan provides) 4g , Beijing Normal University Institute of Applied Chemistry produced 1,1,2,2-methoxymethylated compound of tetraphenol ethane (four methoxymethyl groups per molecule) 15g, Nippon Kayaku Corporation produced PS- 101 (i.e. CY10) infrared absorbing dye 5g, oil soluble blue (Beijing Chemical Reagent Factory) 1g, ethylene glycol monoethyl ether 800g, cyclohexanone 100g, obtain thermosensitive CTP thermosensitive with the dissolving of embodiment 1, preparation and filtration method Imaging fluid TCL-5.

Example 6

Get Shandong Weihai Economic and Technological Development Zone Tiancheng Chemical Company to produce phenolic resin BTB-22 (B) 70g and BZR condensate 4g, p-phenoxydichloroacetophenone 3g that Chiba University of Japan provides, prepare the PAG obtained in Example 2 -22g, Shandong Weihai Economic and Technological Development Zone Tiancheng Chemical Company produces methoxymethylated phenolic resin BTB-4215g, Nippon Kayaku Corporation produces PS-102 infrared absorbing dye 5g, the oil soluble blue 1g of embodiment 5, the 1g of embodiment 3 1 g of Basic Brilliant Blue, 800 g of ethylene glycol monoethyl ether, and 100 g of cyclohexanone were used in the dissolution, preparation and filtration methods of Example 1 to obtain the thermosensitive CTP thermal imaging liquid TCL-6.

Example 7

Get the BTB-26 phenolic resin 70g of embodiment 4, the PAG-15g of preparation embodiment 1 gained, the BTC-101 12.5g of embodiment 3 and RCH condensate 4g, the S 0094 infrared absorption dye 7.5g of embodiment 3, implement Victoria pure blue BOH 1g of example 1, cyclohexanone 900g, obtain thermosensitive CTP sensitive thermographic liquid TCL-7 with the dissolving of embodiment 1, preparation and filtering method.

Example 8

Get the BTB-26 phenolic resin 40g of embodiment 4, prepare the used BTB-24 phenolic resin 30g in the embodiment 3, the RA condensate 5g that Shandong Weihai Economic and Technological Development Zone Tiancheng chemical company produces, the PAG-2 of preparation embodiment 2 gained 5g, the BTC-101 10g of embodiment 3, the BAC-M 2.5g of Japan Toyo Synthetic Industry Co., Ltd., the S 0094 infrared absorption dye 6.5g of embodiment 3, the Victoria pure blue BOH 0.75g of embodiment 1, crystal violet 0.25g , 900g of cyclohexanone, the method of dissolving, preparing and filtering in Example 1 was used to obtain thermosensitive CTP thermal imaging fluid TCL-8.

Example 9

Get the polyp-hydroxystyrene VP-8000 70g of embodiment 2, Shandong Chenghai Economic and Technological Development Zone Tiancheng Chemical Company produces tung oil resorcinol resin TOR adduct 5g, prepares the PAG-1 5g of embodiment 1 gained, embodiment 3 BTB-101 8.5g, BAC-H 4g produced by Japan Toyo Synthetic Industry Co., Ltd., NK-2014 infrared absorbing dye 6g of embodiment 1, basic brilliant blue 1g of embodiment 3, dimethyl yellow of embodiment 2 0.5g, 900g of cyclohexanone, using the dissolving, preparing and filtering method of Example 1 to obtain thermosensitive CTP thermal imaging liquid TCL-9.

Example 10

Get the BTB-26 resin 70g of embodiment 1, RR adduct 5g, the PAG-1 5g of preparation embodiment 1 gained, the Cymel-300 10g of embodiment 2, the BAC-H 3g of embodiment 9, the PAG-1 of embodiment 1 NK-2014 infrared absorbing dye 6g, the oil-soluble blue 0.5g of embodiment 5, the dimethyl yellow 0.25g of embodiment 2, crystal violet 0.25g, cyclohexanone 900g, with the dissolution of embodiment 1, preparation and filtration method The thermosensitive CTP thermal imaging fluid TCL-10 was obtained.

Example 11

Get the BTB-22 (B) phenolic resin 30g of embodiment 6, the BTB-26 phenolic resin 40g of embodiment 4, RA condensate 5g, the PAG-3 5g of preparation embodiment 3 gained, 1-methoxyphenyl-3 , 5-bis-trichloromethyl triazine (Beijing Normal University Experimental Chemical Plant) 1.5g, the BTC-101 10g of embodiment 3, the NK-2268 infrared absorption dye 7.5g of Japanese forest source company, the alkaline of embodiment 3 Brilliant blue 0.5g, dimethyl yellow 0.5g of Example 2, cyclohexanone 900g, using the dissolution, preparation and filtration methods of Example 1 to obtain thermosensitive CTP thermal imaging liquid TCL-11.

Example 12

Get the BTB-134 phenolic resin 50g of embodiment 5, the BTB-22 (B) phenolic resin 20g of embodiment 6, BZR condensate 5g, the PAG-1 5g of preparation embodiment 1 gained, the BTC-101 9g of embodiment 3 , the BAC-M 5g of embodiment 8, the NK-2014 infrared absorbing dye 5g of embodiment 1, the Victoria pure blue BOH 1g of embodiment 1, cyclohexanone 900g, obtain heat with the dissolution of embodiment 1, preparation and filtration method Sensitive CTP thermal imaging fluid TCL-12.

Example 13

Get the novolac resin BTB-31 7g of main chain or end group high etherification rate produced by Tiancheng Chemical Company in Weihai Economic and Technological Development Zone, Shandong Province, prepare 0.7g of PAG-3 gained in Example 3, and prepare PAG obtained in Example 1 -1 0.5g, 3,5-bistrichloromethyl-1-p-methoxystyryl triazine 0.5g of Example 1, Cymel-300 0.5g of Example 2, NK-2014 infrared of Example 2 Absorption dye 0.7g, Victoria Pure Blue BOH 0.1g of Example 1, and cyclohexanone 90g were used for dissolving, preparing and filtering in Example 1 to obtain thermosensitive CTP thermal imaging liquid TCL-13.

Example 14

Get the BTB-32 phenolic resin 8g that Shandong Weihai Economic and Technological Development Zone Tiancheng chemical company produces, the PAG-2 0.7g of preparation embodiment 2 gained, the 1-p-methoxynaphthyl-3 of embodiment 2, 5-two trichloro Methyl triazine 0.2g, BTC-101 0.5g of embodiment 3, PS-101 infrared absorption dye 0.5g of embodiment 5, Victoria pure blue BOH 0.1g of embodiment 1, ethylene glycol monoethyl ether 80g, cyclohexane Ketone 10g, using the dissolution, preparation and filtration methods of Example 1 to obtain thermosensitive CTP thermal imaging fluid TCI-14.

Example 15

Get the BTB-32 8g of embodiment 14, prepare the PAG-3 1g of embodiment 3 gained, the 3 of embodiment 1, 5-bistrichloromethyl-1-p-methoxystyryl triazine 0.1g, embodiment 3 BTC-101 0.3g, PS-102 infrared absorption dye 0.5g of embodiment 6, basic brilliant blue 0.1g of embodiment 3, ethylene glycol monoethyl ether 90g, with the dissolution, preparation and filtration method of embodiment 1 The thermosensitive CTP thermal imaging fluid TCL-15 was obtained.

Example 16

Get the BTB-32 8g of embodiment 14, the VRR solution-resisting solubilizer (rosin-resorcinol resin with protecting group) 0.3g that Shandong Chenghai Economic and Technological Development Zone Tiancheng Chemical Company produces, the BTC-101 of embodiment 3 0.2g, 0.5g of PAG-1 obtained in Preparation Example 1, 1-p-methoxynaphthyl-3,5-bistrichloromethyl triazine 0.4g of Example 2, NK-2268 infrared absorption of Example 11 0.5 g of dye, 0.1 g of oil soluble blue of Example 5, and 90 g of cyclohexanone were used for dissolving, preparing and filtering in Example 1 to obtain thermosensitive CTP thermal imaging liquid TCL-16.

As a comparative example, a reference example and two examples in the patent (Japanese Patent Laid-Open No. 11-119428) applied by Mitsubishi Chemical Corporation were selected as Comparative Example 1, Comparative Example 2 and Comparative Example 3.

Comparative example 1

Take the condensation resin of phenol-m-cresol-p-cresol (molar ratio is 5:3:2) and formaldehyde $(\stackrel{\‾}{m_w}=7500,\stackrel{\‾}{m_{\mathrm{no}}}=900)$ 50g, phenol-formaldehyde novolac resin $(\stackrel{\‾}{m_w}=6100,\stackrel{\‾}{m_{\mathrm{no}}}=900)$ 50g, Cymel-300 20g of Example 2, 5g of cy10 infrared absorbing dye produced by Nippon Kayaku Corporation, 5g of 3,5-bistrichloromethyl-1-methoxystyryl triazine of Example 1, 5g of Example 1 Victoria pure blue BOH 1g, cyclohexanone 1000g, obtain thermosensitive CTP thermographic liquid TCL-1 (comparison) with the dissolving of embodiment 1, preparation and filtering method.

Comparative example 2

On the basis of the ingredients of Comparative Example 1, add wherein 20% of the hydroxyl group is esterified with pyrogallol acetone resin by 2,1,5-diazonaphthoquinone sulfonyl chloride $(\stackrel{\‾}{m_w}=2500)$ 10 g, using the dissolution, preparation and filtration methods of Example 1 to obtain thermosensitive CTP thermal imaging liquid TCL-2 (comparison).

Comparative example 3

On the basis of the ingredients of Comparative Example 1, 20 g of the resin described in Comparative Example 2 was added, and the thermosensitive CTP thermal imaging liquid TCL-3 (comparison) was obtained by the dissolution, preparation and filtration methods of Example 1.

Performance Testing

The thermosensitive imaging liquid of embodiment 1-16 and comparative example 1-3 is coated on the PS plate aluminum base that has been treated in advance and satisfies the following conditions with centrifugal coater:

Aluminum base size: 1030mm×800mm

Aluminum base thickness: 0.28-0.30mm

Grain specification: Ra＝0.5-0.6μm

Rh＝0.3-0.35μm

Anodized film weight: 3-3.5g/m ²

Control the rotational speed of the centrifugal coater so that the coating amount (in terms of solid content) on the aluminum plate base is 1.8-2.2g/m ² , and after preliminary drying on the centrifugal coater, transfer to 100°C blast Dry in a dryer for 3 minutes to obtain heat-sensitive CTP originals TPS-1 to TPS-16 and TPS-1 (comparison) to TPS-3 (comparison), among which TPS-1 to TPS-6 and TPS-1 (comparison) are evaluated The comparison results are listed in Table 1, wherein TPS-7 to TPS-12 and TPS-2 (comparison) evaluation and comparison results are listed in Table 2, and TPS-13 to TPS-16 and TPS-3 (comparison) evaluation and comparison results Listed in Table 3.

Table 1 Evaluation and comparison results of negative thermal crosslinking thermal CTP plates Plate serial number Coating weight (g/m ² ) Solvent residual rate (%) Thermal sensitivity (mJ/cm ² ) Resolution (dpi) Dot reproducibility (%) Durability (10,000 prints) TPS-1 2.10 4.2 150 ≥200 1-98 ≥12 TPS-2 2.01 4.8 100 ≥250 1-98 ≥15 TPS-3 1.95 4.4 125 ≥250 1-98 ≥12 TPS-4 2.05 4.0 125 ≥250 1-99 ≥10 TPS-5 2.15 3.94 160 ≥200 2-99 ≥10 TPS-6 2.06 3.2 200 ≥200 2-98 7.5 TPS-1 (comparison) 2.20 4.9 400 200 2-98 7

Table 2 Evaluation and comparison results of negative image without preheating heat cross-linking thermal CTP plate Plate serial number Coating weight (g/m ² ) Solvent residual rate (%) Thermal sensitivity (mJ/cm ² ) Resolution (dpi) Dot reproducibility (%) Developer dilution ratio TPS-7 2.15 4.8 200 200 2-98 1:5 TPS-8 2.06 4.4 160 200 1-98 1:5 TPS-9 2.01 4.0 175 250 1-98 15 TPS-10 2.05 4.2 175 200 1-98 1.5 TPS-11 2.10 3.9 175 200 2-98 1:5 TPS-12 1.90 3.4 150 250 1-98 1:6 TPS-2 (comparison) 2.20 4.8 unable to image 1:6

Table 3 The evaluation and comparison results of the thermal CTP plate without preheating in the positive image Plate serial number Coating weight (g/m ² ) Solvent residual rate (%) Thermal sensitivity (mJ/cm ² ) Resolution (dpi) Dot reproducibility (%) Developer dilution ratio Durability (10,000 prints) TPS-13 1.96 3.9 175 200 2-98 1:3 ≥7.5 TPS-14 1.90 3.6 200 200 2-98 1:4 TPS-15 1.92 3.2 200 200 2-98 1:4 TPS-16 1.95 3.8 175 200 2-98 1:5 >7 TPS-3 (comparison) 2.18 4.9 >200 200 2-97 1:5

The thermal sensitivity is measured by a thermal CTP plate-making testing machine provided by Creo Company. There are two methods for resolution measurement: one is to simulate the measurement by using the PS plate with signal strips combined with near-ultraviolet light source exposure; the other is to directly measure on the Quansheng 3244 thermal platesetter with the specified software. The developer is KPG commercial negative thermal CTP developer (Thermo 830 negative developer (with preheating)) and positive thermal CTP developer (Horsell Premium Positive Developer).

Conclusion: By properly adjusting the basic composition of the present invention, under different plate-making process conditions, negative heat-crosslinking heat-sensitive CTP plates with high sensitivity, good resolution, and high printing durability, and negative-image non-pre-prepared plates were obtained. Thermal cross-linking thermal CTP plates and positive working thermal CTP plates without preheating.

Claims (14)

1. An imaging composition for thermosensitive CTP plates, comprising the following components: 1) 1-20% by weight, preferably 2-10% by weight of photothermal acid generating source; 2) 50-90% by weight, preferably 60-80% by weight of film-forming resin; 3) 1-20% by weight, preferably 5-15% by weight of crosslinking agent; 4) 1-10% by weight, preferably 4-8% by weight of light-to-heat conversion substances; 5) 0.2-2% by weight, preferably 0.5-1.5% by weight, of a colored background dye; and 6) making the solid content of the composition 10-30% by weight of solvent, Wherein the weight percentage is based on the total solid mass of the composition. 2. The imaging composition according to claim 1, wherein the photothermal acid generating source is a compound represented by the following general formula:   

     

General formula 1 General formula 2 General formula 3 where R is

or

R ₁ is H or C ₁ -C ₄ alkyl, n is 2-5, 2n=m+p, m≥p, and p is not equal to 0. 3. The imaging composition according to claim 2, wherein the photothermal acid generating source further comprises triazine compounds, such as 1-p-methoxystyryl-3,5-bistrichloromethyl triazine, 1-methoxy Phenyl-3,5-bistrichloromethyltriazine, or diphenyliodonium salt or other conventional sources of photoacid generation are used in an amount of 1-10% by weight based on the total solid mass of the composition. 4. The imaging composition according to claim 1, wherein the cross-linking agent is selected from one or more of methoxymethylated melamine, methoxymethylated phenol resin or methoxymethylated polyphenol compound. 5. The imaging composition according to claim 1, wherein the film-forming resin is a novolac resin selected from the group consisting of polypara-hydroxystyrene, poly-ortho-hydroxystyrene, or their weight-average molecular weight _Mw of 5000-20000 Modified product; weight average molecular weight M _w is 3000-8000, M _w / M _n is 3-10 phenol-formaldehyde resin, m-cresol-formaldehyde resin, o-cresol-formaldehyde resin, phenol-m-cresol- Formaldehyde resin, phenol-o-cresol-formaldehyde resin, phenol-p-cresol-formaldehyde resin, phenol-tert-butylphenol-formaldehyde resin, phenol-m-cresol-p-cresol-formaldehyde resin, m-cresol-p-cresol Phenol-formaldehyde resin and m-cresol-tert-butylphenol-formaldehyde resin, etc. 6. The imaging composition according to claim 1, wherein the light-to-heat conversion material is one or more selected from the following: benzindole series cyanine dyes, step cyanine dyes and various phenolic resin imaging compositions Infrared absorbing dye for λ _max = 825-840 nm. 7. The imaging composition according to claim 1, wherein the colored background dye is one or more selected from the group consisting of oil soluble blue, basic brilliant blue, Victoria pure blue, indigo, methyl violet, crystal violet, peacock Stone Green, Sudan Black, Methyl Orange, Eosin, Dimethyl Yellow, Fluorescent Yellow. 8. The imaging composition according to claim 1, wherein the solvent is selected from the group consisting of cyclohexanone, methyl ethyl ketone, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, gamma-butyrolactone, ethyl lactate, butyl acetate, dioxane Ring, tetrahydrofuran, trichloroethylene, chloroform, dichloromethane, their consumption accounts for 70-90% in the total mass of imaging liquid. 9. The photothermal acid generation source shown in the following general formula 1, general formula 2 and general formula 3:  

      General formula 1 General formula 2 General formula 3 where R is

or R ₁ is H or C ₁ -C ₄ alkyl, n is 2-5, 2n=m+p, m≥p, and p is not equal to 0. 10. A method for preparing a photothermal acid generating source as claimed in claim 9, comprising 2,1,4-diazonaphthoquinone sulfonyl chloride or p-toluenesulfonyl chloride and selected from N-hydroxyl imides , polyhydric phenolic compound and novolac resin with a weight average molecular weight of 2000-4000 for esterification or grafting precursor reaction and separating the obtained product. 11. A method for preparing a negative heat-crosslinking type heat-sensitive CTP printing plate, comprising applying the imaging composition according to claim 1 to a heat-sensitive CTP original plate on the treated aluminum plate base, by heat-sensitive CTP The plate-making machine performs infrared laser scanning, then preheats at 120-130°C for about 1 minute, and then develops in a lithographic developing machine equipped with an alkaline developer. 12. A method for preparing a negative image without preheating heat-crosslinking type thermal CTP printing plate, comprising coating a thermal CTP original plate with the imaging composition described in claim 1, and then first using an output wavelength of 320-450nm The near-ultraviolet light source is fully exposed, and the exposure amount is controlled at 150-250mJ/cm ² , and then infrared laser scanning is carried out by a thermal platemaking machine, and it is directly developed in a lithographic developing machine equipped with an alkaline developer without a preheating process. 13. A method for preparing a positive-working heat-sensitive CTP printing plate without preheating, comprising coating a heat-sensitive CTP original plate with the imaging composition according to claim 1, and directly entering the Development is carried out in a weak alkaline water developing solution, wherein the acid-generating source is selected from the photothermal acid-generating source of general formula 3 described in claim 2 and the upper limit dosage described in claim 1 is selected, and the cross-linking agent is selected from claim 1 Described lower limit dosage and selects the film-forming novolac resin with high acidolysis activity for use. 14. A thermosensitive CTP printing plate prepared by the method of any one of claims 11-13.