CN115612223A - Hybrid polymer of polyvinyl alcohol derivative and polyacrylic resin and chemical-resistant thermosensitive plate - Google Patents

Abstract

The invention provides a hybrid polymer of a polyvinyl alcohol derivative and polyacrylic resin and a chemical-resistant thermosensitive plate, wherein the polyvinyl alcohol derivative is a product obtained by urethane reaction of polyvinyl alcohol and isocyanate acrylate; the molecular structural unit of the polyacrylic resin at least contains a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: an alkali-soluble group-containing acrylic copolymer unit; the hybrid polymer of the polyvinyl alcohol derivative and the polyacrylic resin has excellent chemical resistance, the chemical-resistant thermosensitive plate contains the hybrid polymer, and the imaging layer has excellent chemical resistance, so the imaging quality and the pressrun of the thermosensitive plate are obviously improved.

Description

Hybrid polymer of polyvinyl alcohol derivative and polyacrylic resin and chemical-resistant thermosensitive plate

Technical Field

The invention belongs to the technical field of lithographic printing, and particularly relates to a hybrid polymer of a polyvinyl alcohol derivative and polyacrylic resin and a chemical-resistant thermosensitive plate.

Background

Computer To Plate (CTP) was first developed in the 80 th 20 th century, and CTP technology is now widely used in modern printing fields, and common CTP plates are classified into photosensitive CTP plates (photosensitive plates for short) and thermosensitive CTP plates (thermosensitive plates for short) according to an imaging laser source.

The heat-sensitive plate is an offset plate which adopts infrared laser to image. Thermal plates are used in a wide variety of applications due to their bright room operation and high imaging quality. The positive thermosensitive plate making technology is the most mature, stable and effective plate making technology at present. With the stricter environmental requirements of various countries, the UV ink does not contain volatile solvents, so that the UV ink is widely applied in the printing field in order to reduce the atmospheric environmental pollution. However, since the UV ink contains a UV-curable monomer, it erodes the image layer of the conventional thermal plate during printing, and the image layer is swollen or partially dissolved, causing dot gain blur and a sharp drop in printing durability. Therefore, the key point of the development of the current thermosensitive plate is to improve the chemical resistance and the printing resistance of the plate material.

One of the most important methods for improving the chemical properties of the heat-sensitive plate is the development of a heat-sensitive layer composition and a functional resin of the plate material. Ismann kodak, CN101321632A, discloses that the chemical resistance of a plate material is improved by introducing a phosphoric acid side group or an adamantane side group into a polymer; aceka in WO 2004035686) discloses that a polymer containing N-pyrazole groups increases the chemical resistance of the printing plate; fuji film CN201380011228.4 discloses a method for improving chemical resistance and printing resistance of a printing plate by adding a polyvinyl acetal resin to the printing plate.

Disclosure of Invention

In order to solve the problems, the invention provides a hybrid polymer of a polyvinyl alcohol derivative and polyacrylic resin and a chemical-resistant thermosensitive plate, wherein the hybrid polymer of the polyvinyl alcohol derivative and the polyacrylic resin has excellent chemical resistance, the chemical-resistant thermosensitive plate contains the hybrid polymer, and an imaging layer has excellent chemical resistance, so that the imaging quality and the printing resistance of the thermosensitive plate are obviously improved.

The object of the invention is achieved in the following way: a hybrid polymer of polyvinyl alcohol derivative and polyacrylic resin, the polyvinyl alcohol derivative is the product obtained by urethane reaction of polyvinyl alcohol and isocyanate acrylate; the molecular structural unit of the polyacrylic resin contains at least a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: an alkali-soluble group-containing acrylic copolymer unit; the hybridization mode of the polyvinyl alcohol derivative and the polyacrylic resin is as follows: firstly, polyacrylic resin is synthesized, and polyvinyl alcohol derivatives are added in the later reaction stage of polyacrylic resin synthesis for hybridization to obtain a hybrid polymer of the polyvinyl alcohol derivatives and the polyacrylic resin. Namely, firstly, polyacrylic resin is synthesized, and in the later stage of the reaction for synthesizing polyacrylic resin, polyvinyl alcohol derivatives are added to continue double bond polymerization reaction when the reaction is not ended, which is similar to the block reaction of high molecules.

Meanwhile, according to the characteristics of the hybrid polymer, a supermolecule hydrogen bond association mechanism thermosensitive plate is designed and developed, the plate material contains the hybrid polymer, particularly the thermosensitive plate simultaneously contains a special sensitizer, and the thermosensitive plate has excellent chemical resistance.

First, a hybrid polymer of a polyvinyl alcohol derivative and a polyacrylic acid resin is described:

a hybrid polymer of a polyvinyl alcohol derivative and a polyacrylic resin: the polyvinyl alcohol derivative is a product obtained by urethane reaction of polyvinyl alcohol and isocyanate acrylate; the polyacrylic resin contains molecular structural units at least comprising a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: an alkali-soluble group-containing acrylic copolymer unit; the hybridization mode of the polyvinyl alcohol derivative and the polyacrylic resin is as follows: firstly, polyacrylic resin is synthesized, and the polyvinyl alcohol derivative is hybridized in the synthesis process to form a hybrid polymer.

Wherein, the polyvinyl alcohol derivative is a product obtained by the amino esterification reaction of hydroxyl in polyvinyl alcohol and isocyanate in isocyanate acrylate. At present, isocyanate acrylate is a brand new functional monomer in the world, and the basic structure of the isocyanate acrylate is as follows:

R ¹ is a hydrogen atom or a methyl group, R ² Is an ester group, an aryl group, a covalent bond or the like, and r is an integer of 1 to 3.

The isocyanate-acrylate copolymer contains isocyanate groups and double bonds, and only two isocyanate-acrylate (AOI, CAS: 13641-96-8) and isocyanate-methacrylate (MOI, CAS: 30674-80-7) are successfully developed and industrialized in the world at present.

The polyacrylic acid resin is described next. The polyacrylic resin contains molecular structural units at least comprising a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: an acrylic copolymer unit containing an alkali-soluble group. The polyacrylic resin preferably used in the present invention is a copolymer unit a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: a ternary radical copolymer of acrylic acid or methacrylic acid. Wherein: in the polyacrylic resin, the weight proportion of the monomer a p-hydroxystyrene is 10-70%, the weight proportion of the monomer b acrylamide is 10-70%, and the weight proportion of the monomer c acrylic acid or methacrylic acid is 10-30%.

One of polyacrylic resin copolymerization components: p-hydroxystyrene, which contains a rigid benzene ring structure and can provide chemical resistance, wherein a hydrogen bond at a meta position on the benzene ring and a hydrogen bond at a para-hydroxyl group and alkali-soluble resin jointly form supermolecular hydrogen bond association; releasing phenolic hydroxyl after the association is released under the action of laser heat, and developing the phenolic hydroxyl by alkali to realize imaging; meanwhile, the resin contains the same phenolic hydroxyl structure as the alkali-soluble resin, so that the compatibility of the two resins is improved, the intermolecular hydrogen bond association is facilitated, and the solvent resistance of the printing plate is improved.

One of the copolymerization components of the polyacrylic resin: acrylamide or methacrylamide is a strong polar monomer, can endow the high polymer resin with excellent chemical resistance, can improve the chemical corrosion resistance of the thermosensitive layer, and can improve the printing resistance of the printing plate.

One of copolymerization components of polyacrylic resin: acrylic acid or methacrylic acid. The alkali-soluble group provides image imaging for the plate material during alkali development, and common acrylic monomers of the alkali-soluble group comprise acrylic monomers containing carboxyl, sulfonic acid group, phosphoric acid group, amino, phenolic hydroxyl and the like. The alkali-soluble group is preferably carboxyl, and the carboxylic acid acrylic acid monomer has the advantage of high cost performance.

The hybridization mode of the polyvinyl alcohol derivative and the polyacrylic resin is as follows: firstly, the terpolymer is synthesized, and the polyvinyl alcohol derivative is hybridized in the synthesis process to form the hybrid polymer.

A chemical-resistant thermosensitive plate comprising a hydrophilic support and a thermosensitive layer, wherein the thermosensitive layer contains a hybrid polymer of a phenolic resin, a polyvinyl alcohol derivative and a polyacrylic resin.

Wherein the thermosensitive layer further contains a sensitizer.

Wherein the thermosensitive layer further contains an infrared absorbing dye and a background dye.

The heat-sensitive layer comprises, by weight, 40-80% of phenolic resin, 10-50% of hybrid polymer of polyvinyl alcohol derivative and polyacrylic resin, 1-10% of sensitizer, 1-5% of infrared absorption dye and 1-5% of background dye.

The phenolic resin is at least one of m-cresol phenolic resin, m-cresol-p-cresol phenolic resin, phenol-p-cresol phenolic resin, o-cresol-p-cresol phenolic resin, phenol-m-cresol-p-cresol phenolic resin and polyurethane modified linear phenolic resin; the phenolic resin is m-cresol phenolic resin (Mw is 4000-8000, mw/Mn is 4-8), m-cresol-p-cresol phenolic resin (the molar ratio of m-cresol to p-cresol is 3: 2 to 4: 1, mw is 4000-10000, and Mw/Mn is 4-12), phenol-p-cresol phenolic resin (the molar ratio of phenol to p-cresol is 5: 5 to 3: 7, mw is 4000-6000, and Mw/Mn is 4-6), o-cresol-p-cresol phenolic resin, phenol-o-cresol-p-cresol phenolic resin (the molar ratio of phenol, o-cresol, and p-cresol is 2: 1: 7, mw is 6000-9000, and Mw/Mn is 6-9), phenol-m-cresol-p-cresol phenolic resin (the molar ratio of phenol, m-cresol, and p-cresol is 1: 6: 4, mw is 7000-10000, and Mw/Mn is 7-10), and polyurethane modified linear phenolic resin (Mw is 12000-8000, mw/Mn is 5000-1358, mw/Mn is 1-30%, and Mw/Mn is preferably 1-40.1-30% of the total weight of the polyethylene modified linear phenolic resin.

The infrared absorption dye is a cyanine dye with an absorption peak between 750 and 850 nm.

The background dye is any one of oil-soluble blue, alkaline brilliant blue, victoria pure blue, phthalocyanine blue, malachite green, dark green, phthalocyanine green, crystal violet, methyl violet, ethyl violet, dimethyl yellow and fluorescent yellow.

In order to improve the imaging performance of the thermosensitive plate, the thermosensitive layer contains a sensitizer. The good sensitizer has the functions of hydrogen bond association, laser thermal decomposition development imaging and solvent resistance. The sensitizer is 5-ethyl-5-phenyl-1-methyl-2,4,6- (1H, 3H, 5H) -pyrimidinetrione (abbreviated as phenobarbital). The phenolic resin containing aromatic ring structure has good compatibility with phenolic resin and hybrid resin with aromatic ring structure, avoids the transfer of small molecules, and improves the chemical resistance of the thermosensitive plate.

The infrared absorbing dye component in the thermosensitive layer is detailed below: the infrared absorption dye mainly plays a role in converting laser infrared light into heat energy more effectively, and thermosensitive imaging is realized. The infrared absorbing dye has a maximum absorption wavelength in the range of 750 to 1100nm and is selected from the group consisting of carbon black, azo dyes, triarylamine dyes, indolium dyes, oxonol dyes, cyanine dyes, merocyanine dyes, indocyanine dyes, phthalocyanine dyes, polythiophene dyes, pyrazoline azo dyes, oxazine dyes, naphthoquinone dyes, anthraquinone dyes, quinoneimine dyes, methine dyes, porphyrin dyes, and the like. The invention is preferably cyanine dye with the wavelength of 750-850nm, and the infrared absorption dye accounts for 1-5% of the total solid of the heat-sensitive layer composition.

The background dye in the thermosensitive layer is detailed below: the background dye plays a role in coloring the image layer, so that the image density of the heat-sensitive plate after plate making is increased, and the heat-sensitive plate after plate making is convenient to carry out visual inspection or image analysis and measurement equipment is used for measuring the performance of the plate material. The background dye is any one of oil soluble blue, basic brilliant blue, victoria pure blue, phthalocyanine blue, malachite green, dark green, phthalocyanine green, crystal violet, methyl violet, ethyl violet, dimethyl yellow and fluorescent yellow, and accounts for 1-5% of the total solid of the thermosensitive layer composition.

Finally, the hydrophilic support of the thermal plate of the invention is detailed: the thermosensitive plate composition of the invention is required to be coated on a thermosensitive plate hydrophilic carrier, and the thermosensitive plate carrier comprises a metal plate base such as a copper plate base, an aluminum plate base and the like. The hydrophilic carrier selected by the invention is an aluminum plate base which is subjected to electrolytic roughening, anodic oxidation and hole sealing treatment, the average roughness of the central line is 0.3-0.6um, and the hydrophilic carrier is prepared by electrolytic roughening. The aluminum plate base is more than 99 percent of aluminum, 0.1 to 0.5 percent of iron, 0.03 to 0.3 percent of silicon, 0.003 to 0.03 percent of copper and 0.01 to 0.l percent of titanium. The electrolytic roughening electrolyte may be an aqueous solution of an acid, base or salt. Firstly, the aluminum plate is put into 1% -30% aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate and the like, and is chemically corroded at the temperature of 20-80 ℃ for 5-250 seconds. Then neutralizing in 10% -30% nitric acid or sulfuric acid at 20-70 deg.C to remove gray matter. Electrolyzing at 10-60 deg.C with square wave, table wave or sine wave with positive and negative interaction at current density of 5-100A/dm2 in electrolyte of nitric acid or hydrochloric acid for 10-300 s. Then, anodic oxidation treatment is performed. The anodic oxidation is usually carried out by sulfuric acid method, using sulfuric acid with concentration of 5-30%, current density of 1-15A/dm2, oxidation temperature of 20-60 deg.C, oxidation time of 5-250 s to form 1-10g/m2 oxide film, and finally sealing with sodium silicate aqueous solution.

The thermosensitive layer of the present invention may be produced by adding other necessary additives such as solvents, surfactants, etc. The solvent is mainly used for preparing the thermosensitive layer into a coating liquid, and comprises the following components: alcohols, ketones, esters, ethers, amides, aromatic solvents, ethylene dichloride, tetrahydrofuran, and the like, the solvents may be used in pure form or in the form of a mixture; the surfactant can be selected from nonionic surfactant, amphoteric surfactant, silicon-containing surfactant, fluorine-containing surfactant, etc., such as betaine, glyceryl stearate, sorbitan, polysiloxane, and polyfluoroalkyl ether.

The heat-sensitive layer of the present invention is typically applied by techniques known in the art such as knife coating, bar coating, roll coating, press coating, and the like.

Relative to the prior art, the copolymerization components of the hybrid polymers of the invention: p-hydroxystyrene, which contains a rigid benzene ring structure and can provide chemical resistance, wherein a hydrogen bond at a meta position on the benzene ring and a hydrogen bond at a para-hydroxyl group and phenolic resin jointly form supermolecular hydrogen bond association; acrylamide can endow high molecular resin with excellent chemical resistance, acrylic monomers contain alkali-soluble groups to provide good alkali development imaging performance, a hybrid polymer contains a urethane bond which has an anti-wear effect, and the urethane bond contains a strong polar hydrogen bond which can form supermolecular hydrogen bond association with phenolic hydroxyl in the alkali-soluble resin; the copolymer component also contains diphenyl at the tail end of a side chain, and has good rigidity and chemical resistance.

In the chemical-resistant thermosensitive plate, the hybrid polymer and phenolic resin molecules can form association with hydrogen bonds, the hydrogen and phenolic hydroxyl groups on benzene rings in the solvent-resistant resin and phenolic resin molecules both contain hydrogen bonds, and the molecules are associated by the hydrogen bonds to form an alkali dissolution resistant structure, so that the association effect is more complete in laser pyrolysis removal under the existence of a sensitizer, the special sensitizer contains an aromatic ring structure, and the special sensitizer has good compatibility with the phenolic resin and the hybrid resin which also have the aromatic ring structure, thereby avoiding the transfer of small molecules and improving the chemical resistance of the thermosensitive plate.

Detailed Description

The following are examples of the synthesis of the present invention, but the present invention is not limited to the following examples. The following synthetic examples are intended to illustrate the invention further and are not to be construed as limiting the scope of the invention, which is intended to be covered by the claims and that insubstantial modifications and adaptations of those skilled in the art may be made in view of the above disclosure.

Raw materials and their codes, acquisition company: p-hydroxystyrene (PHS): hubei Jusheng science and technology; acrylonitrile (AN): chemical reagents for Tianjin Feng boat; isocyanate ethyl Acrylate (AOI) and isocyanate ethyl Methacrylate (MOI): showa electric corporation; polyvinyl alcohol PVA550, PVA500 from Korea, azobisisobutyronitrile (AIBN): tianjin Fuchen chemical reagent; dibutyltin dilaurate: tianjin chemical reagent II; dimethylsulfoxide DMSO and Dimethylformamide (DMF): chemical of Shanghai Lincarbon.

The basic synthesis method is as follows:

firstly synthesizing an intermediate polyvinyl alcohol derivative for later use:

synthesis of polyvinyl alcohol derivative M1: adding 100g of PVA550, 20g of isocyanate ethyl Acrylate (AOI), 1g of dibutyltin dilaurate and 400g of dimethyl sulfoxide into a500 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, and stirring at 70 ℃ for reacting for 3 hours to finish the reaction, wherein the intermediate M1 is reserved;

synthesis of polyvinyl alcohol derivative M2: adding 100g of PVA500, 20g of isocyanate ethyl Methacrylate (MOI), 1g of dibutyltin dilaurate and 400g of dimethyl sulfoxide into a500 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, and reacting at 70 ℃ for 3 hours to finish the reaction, wherein an intermediate M2 is reserved;

hybrid polymer P1:

70g of P-hydroxystyrene, 20g of acrylamide, 10g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, added with 10g of M1, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried at 45 ℃ in vacuum to obtain the hybrid polymer P1.

Hybrid polymer P2:

70g of P-hydroxystyrene, 20g of acrylamide, 10g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted for 8 hours at 70 ℃, added with 20g of M1, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried in vacuum at 45 ℃ to obtain the hybrid polymer P2.

Hybrid polymer P3:

60g of P-hydroxystyrene, 30g of acrylamide, 10g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, added with 10g of M2, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried at 45 ℃ in vacuum to obtain the hybrid polymer P3.

Hybrid polymer P4:

50g of P-hydroxystyrene, 40g of acrylamide, 10g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, 30g of M2 is added, the reaction is continued for 30 minutes, the temperature is reduced, the reaction stock solution is dropped into deionized water to be separated out, washed and filtered, and vacuum drying is carried out at 45 ℃ to obtain the hybrid polymer P4.

Hybrid polymer P5:

40g of P-hydroxystyrene, 40g of acrylamide, 20g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted for 8 hours at 70 ℃, added with 10g of M1, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried in vacuum at 45 ℃ to obtain the hybrid polymer P5.

Hybrid polymer P6:

30g of P-hydroxystyrene, 50g of acrylamide, 20g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, 50g of M1 is added, the reaction is continued for 30 minutes, the temperature is reduced, the reaction stock solution is dropped into deionized water to be separated out, washed and filtered, and vacuum dried at 45 ℃ to obtain the hybrid polymer P6.

Hybrid polymer P7:

20g of P-hydroxystyrene, 60g of acrylamide, 20g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, 70g of M1 is added, the reaction is continued for 30 minutes, the temperature is reduced, the reaction stock solution is dropped into deionized water to be separated out, washed and filtered, and vacuum dried at 45 ℃ to obtain the hybrid polymer P7.

Hybrid polymer P8:

10g of P-hydroxystyrene, 70g of methacrylamide, 20g of acrylic acid, 1g of azobisisobutyronitrile and 777700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, the mixture is uniformly stirred, the mixture reacts at 70 ℃ for 8 hours, 100g of M1 is added, the reaction is continued for 30 minutes, the reaction is finished by cooling, a reaction stock solution is dropped into deionized water to be separated out, and the resin P8 is obtained by washing and filtering and vacuum drying at 45 ℃.

Chemical-resistant resin P9:

10g of P-hydroxystyrene, 60g of acrylamide, 30g of acrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, 40g of M2 is added, the reaction is continued for 30 minutes, the temperature is reduced, the reaction stock solution is dropped into deionized water to be separated out, washed and filtered, and vacuum drying is carried out at 45 ℃ to obtain the hybrid polymer P9.

Hybrid polymer lipid P10:

70g of P-hydroxystyrene, 10g of acrylamide, 20g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, added with 10g of M2, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried at 45 ℃ in vacuum to obtain the hybrid polymer P10.

Hybrid polymer P11:

40g of P-hydroxystyrene, 30g of methacrylamide, 30g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted for 8 hours at 70 ℃, 80g of M2 is added, the reaction is continued for 30 minutes, the temperature reduction is finished, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and vacuum dried at 45 ℃ to obtain the hybrid polymer P11.

Hybrid polymer P12:

30g of P-hydroxystyrene, 40g of acrylamide, 30g of methacrylic acid, 1g of azobisisobutyronitrile and 700g of dimethylformamide are added into a 1000 ml four-neck flask with a temperature control heating device, a mechanical stirring device, a condensation reflux device and a nitrogen protection device, uniformly stirred, reacted at 70 ℃ for 8 hours, added with 100g of M2, continuously reacted for 30 minutes, cooled to finish the reaction, the reaction stock solution is dripped into deionized water to be separated out, washed and filtered, and dried in vacuum at 45 ℃ to obtain the hybrid polymer P12.

Example 1

Preparing a substrate: a1050-rolled aluminum plate having a purity of 99.5% and a thickness of 0.3mm was immersed in a 5% aqueous solution of sodium hydroxide at 70 ℃ for 20 seconds, washed with running water, and immediately neutralized with A1% aqueous solution of nitric acid. Then, the resultant was subjected to electrolytic roughening with a sine wave alternating current at 40 ℃ for 16 seconds at a current density of 50A/dm2 in a 1% hydrochloric acid aqueous solution, followed by neutralization with a 5% sodium hydroxide aqueous solution at 40 ℃ for 10 seconds, and washing with water. Finally, the anode was oxidized at a current density of 15A/dm2 for 20 seconds at 30 ℃ with a 20% aqueous solution of sulfuric acid, and washed with water. The plate base obtained by sealing treatment with a 5% aqueous solution of sodium silicate at 80 ℃ for 18 seconds, washing with water and drying had an average thickness of 0.5 μm on the center line and an oxide film weight of 3.0g/dm2.

Coating a heat-sensitive layer: the coating liquid of the heat-sensitive layer below is extruded and coated on the plate base subjected to hydrophilization treatment, and then dried at 100 ℃ for 60 seconds to obtain the dry weight of the coating of 1.5 g/square meter. The heat-sensitive layer comprises the following components in parts by weight:

hybrid polymer: p1 resin 40g

Phenolic resin: BTB225 resin 40g

Sensitizer: phenobarbital 10g

Infrared absorbing dye ADS830 g

Background dye: methyl Violet 5g

Adding 700g of propylene glycol methyl ether and 0.5g of surfactant (BYK 306) into the thermosensitive layer component to prepare thermosensitive layer coating liquid, wherein the sensitizer is 5-ethyl-5-phenyl-1-methyl-2,4,6- (1H, 3H, 5H) -pyrimidinetrione, which is called phenobarbital for short; the infrared absorbing dye ADS830 has the structure: 2- (2- { 2-chloro-3- [2- (1,1,3-trimethyl-2,3-dihydro-1H-benzo [ e ] indol-2-ylidene) ethylidene ] -1-cyclohexenyl } -1-vinyl) -1,1,3-trimethyl-1H-benzo [ e ] indolium 4-methyl-1-benzenesulfonate, available from American Dye source in.

Method for testing a thermal plate:

1. chemical resistance detection method: the plate samples were immersed in a solution of isopropanol and water (mass ratio 1:1) at 23 ℃ for 30 minutes, rinsed with deionized water, and the plate coating loss was determined, with the test results shown in table 3.

2. And (3) testing the sensitivity: on a SCREEN8600E plate making machine, using a self-contained test strip, an imaging and screening 175lpi, outputting the resolution of 2400dpi, the drum speed (rpm) of 800, the initial value of the exposure intensity of 40 percent, the stepping interval of the exposure intensity of 2 percent and the number of the exposure strips of 20; scanning plate making with different laser energy is carried out on a sample plate by using a Wangchang developing machine, lekehua light developing solution TPD-83, the developing temperature is 25 ℃, the developing speed is 25 seconds (100 cm/min), the conductivity of the developing solution is controlled to be 89-91 ms/cm, the dynamic supplement of the developing solution is 120ml/m < 2 >, and then the exposure laser quantity determined by the following method is the sensitivity. The 50% open mesh values at different exposure energies were measured with X-rite densitometer IC-Plate2 until a value was found in which 50% of the open mesh area in the ladder bar was in the range of 49.5% to 50.4%, which is the sensitivity of the Plate, and the test results are shown in Table 3.

3. Detecting the development tolerance: on an SCREEN8600E plate making machine, exposure is carried out according to the exposure amount which is 1.1 times of the obtained sensitivity value, a self-contained test strip is used for carrying out scanning plate making on a sample, and the sample is developed and processed at different developing time, so that the difference between the highest value and the lowest value of the developing time of the plate material can meet the use requirement (no blank is left, the density OD value is less than 0.29, the coating does not reduce the film in the field, the density loss is less than or equal to 4 percent, and the dot reduction is 2-99 percent) is the development tolerance of the plate material, and the test result is shown in a table 3.

4. And (3) measuring the printing resistance: the plate samples were printed normally on a machine (northern four-color quarto high-speed rotary press), and the press resistance was examined, the test results are shown in table 3.

The components of the thermosensitive layers in examples 2 to 9 are shown in Table 1 below, and other preparation methods and methods for testing thermosensitive plates are the same as in example 1, and the test results are shown in Table 3.

Table 1:

wherein the phenolic resin BTB225 resin is from Wihaitian chemical industry Co., ltd, the poly-p-hydroxystyrene PVPH80 is from Lekea Huaguang printing technology Co., ltd, and the infrared absorption dye LC-01 is from Honywell.

Comparative examples 1-3 components of heat-sensitive layers general heat-sensitive plates comparative examples 1-3 were prepared and tested in the same manner as in example 1, as in the following table 2, and the test results are shown in table 3.

Table 2:

wherein the phenolic resin BTB225 resin is from Wihaitian chemical industry Co., ltd, the poly-p-hydroxystyrene PVPH80 is from Lekea Huaguano printing technology Co., ltd, the infrared absorption dye LC-01 is from Honywell, and the solvent retarder NINS is from Wihaitian chemical industry Co., ltd.

TABLE 3

The detection application results in table 3 show that compared with the first generation thermosensitive plate with the dissolution-inhibiting and dissolution-promoting mechanism, the second generation thermosensitive plate with the supramolecular hydrogen bond association mechanism has the following advantages that the hybrid polymer contained in the second generation thermosensitive plate with the supramolecular hydrogen bond association mechanism has excellent chemical resistance, imaging capability and printing resistance: the special sensitizer contains an aromatic ring structure, has good compatibility with phenolic resin and hybrid resin which also have the aromatic ring structure, avoids the transfer of small molecules, and has excellent chemical resistance.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. A hybrid polymer of a polyvinyl alcohol derivative and a polyacrylic resin, characterized in that: the polyvinyl alcohol derivative is a product obtained by urethane reaction of polyvinyl alcohol and isocyanate acrylate; the polyacrylic resin molecular structural unit at least contains a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: an alkali-soluble group-containing acrylic copolymer unit; the hybridization mode of the polyvinyl alcohol derivative and the polyacrylic resin is as follows: firstly, polyacrylic resin is synthesized, and polyvinyl alcohol derivatives are added in the later reaction stage of polyacrylic resin synthesis for hybridization to obtain a hybrid polymer of the polyvinyl alcohol derivatives and the polyacrylic resin.

2. Hybrid polymer of a polyvinyl alcohol derivative and a polyacrylic acid resin according to claim 1, characterized in that: the isocyanate acrylate is isocyanate ethyl acrylate or isocyanate ethyl methacrylate.

3. Hybrid polymer of polyvinyl alcohol derivatives and polyacrylic resins according to claim 1, characterized in that: the polyacrylic resin is a copolymer unit a: p-hydroxystyrene, b: acrylamide or methacrylamide and c: a ternary free radical copolymer of acrylic acid or methacrylic acid; wherein: in the polyacrylic resin, the weight proportion of the p-hydroxystyrene monomer b is 10-70%, the weight proportion of the acrylamide monomer b is 10-70%, and the weight proportion of the acrylic acid or methacrylic acid monomer c is 10-30%.

4. Use of a hybrid polymer according to any of claims 1 to 3 in a heat-sensitive plate.

5. A chemical-resistant thermal plate, characterized by: the thermosensitive plate comprises a hydrophilic carrier and a thermosensitive layer, wherein the thermosensitive layer contains a hybrid polymer of a polyvinyl alcohol derivative and a polyacrylic acid resin, a phenolic resin, and the hybrid polymer of the polyvinyl alcohol derivative and the polyacrylic acid resin is the hybrid polymer of any one of claims 1 to 3.

6. The chemical-resistant thermal plate according to claim 5, characterized in that: wherein the thermosensitive layer further contains a sensitizer; the thermosensitive layer also contains an infrared absorbing dye and a background dye.

7. The chemical-resistant thermal plate according to claim 6, characterized in that: the thermosensitive layer comprises, by weight, 40-80% of phenolic resin, 10-50% of hybrid polymer of polyvinyl alcohol derivative and polyacrylic resin, 1-10% of sensitizer, 1-5% of infrared absorption dye and 1-5% of background dye.

8. The chemical-resistant thermal plate according to claim 6, characterized in that: the phenolic resin is at least one of m-cresol phenolic resin, m-cresol-p-cresol phenolic resin, phenol-p-cresol phenolic resin, o-cresol-p-cresol phenolic resin, phenol-m-cresol-p-cresol phenolic resin and polyurethane modified linear phenolic resin;

the infrared absorption dye is a cyanine dye with an absorption peak of 750-850 nm;

the background dye is any one of oil-soluble blue, alkaline brilliant blue, victoria pure blue, phthalocyanine blue, malachite green, dark green, phthalocyanine green, crystal violet, methyl violet, ethyl violet, dimethyl yellow and fluorescent yellow.

9. The chemical-resistant thermal plate according to claim 6, characterized in that: the sensitizer is 5-ethyl-5-phenyl-1-methyl-2,4,6- (1H, 3H, 5H) -pyrimidinetrione.

10. The chemical-resistant thermal plate according to claim 5, characterized in that: the hydrophilic carrier is an aluminum plate base which is subjected to electrolytic coarsening and anodic oxidation and is subjected to hole sealing treatment.