UV ink-resistant photosensitive elastomer prepolymer and digital flexible resin plate thereof

Abstract

The invention belongs to the technical field of flexible printing plate materials, and relates to a UV ink-resistant photosensitive elastomer prepolymer and a digital flexible resin plate thereof, liquid epoxy-terminated polybutadiene and liquid hydroxyl-terminated polybutadiene are introduced into the photosensitive elastomer prepolymer, the embossed image-text part of the photosensitive elastomer prepolymer has good wear resistance during UV ink printing, and the UV ink-resistant photosensitive elastomer prepolymer can be applied to the digital flexible resin plate. The embossment image-text surface is improved, and the plate material pressrun of the digital flexible resin plate is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible printing plates, and relates to UV-resistant ink photosensitive elastomer prepolymer and a digital flexible resin plate thereof. Background Art

[0002] Flexographic printing, also known as flexographic printing, is a printing method that uses flexible plates, flexographic inks and special printing equipment. Due to its advantages such as low printing pressure, soft plates, high print durability and good ink transfer performance, it is widely used in printing various materials such as paper, plastic, metal, glass, etc. In flexographic printing technology, the choice of ink is particularly important.

[0003] The mainstream flexographic inks on the market are mainly the following: solvent-based inks, water-based inks, EB inks and UV inks. Solvent-based inks have the characteristics of fast drying speed, good gloss, strong water resistance and bright ink color, and are widely used in non-food packaging fields, such as plastic printing; but the volatilization of its organic solvents is toxic to the environment and human health. Water-based inks are environmentally friendly, non-toxic, harmless, and have strong coloring power. They are mainly used for paper printing; but they have a slow drying speed and poor water resistance, so they need to use external conditions such as hot air to accelerate drying, and are not suitable for film printing. EB inks are environmentally friendly, energy-saving and efficient, and are widely used in the field of high-speed printing. They need to be bombarded by electron beams to induce the polymerization reaction of the resin, so that the ink can be solidified; but there are technical problems. UV inks, with their characteristics of instant drying, good wear resistance, high gloss, safety, reliability and environmental protection, are general-purpose inks suitable for fine product printing and are widely used in the field of high-end printing.

[0004] The biggest advantage of UV ink is its environmental friendliness. Traditional inks contain a large amount of organic solvents, which will evaporate into the atmosphere during the drying process, causing environmental pollution. However, UV inks hardly volatilize organic solvents during the curing process, greatly reducing pollution to the environment. In addition, UV inks do not require the use of water spray devices, reducing the use of water resources and the generation of wastewater. These environmental characteristics of UV inks meet the needs of today's society for green printing. In addition, during the printing process, it is not easy to paste or pile up the plate, the dots are highly clear, the gradation reproducibility is good, the ink color is also bright and ink-saving, which has good advantages in production efficiency, quality and environmental sustainability, promoting the development of industrial greening and providing more choices for packaging processing companies.

[0005] It is foreseeable that the future printing market will pay more attention to environmental protection and high quality, and UV-resistant flexographic resin printing technology can just meet the demand. At present, the selection of UV-resistant digital flexographic resin plates on the market is relatively limited, and there are generally problems such as insufficient printability and poor wear resistance when printing with UV ink. In view of this, it is particularly urgent and important to develop a UV-resistant digital flexographic resin plate with excellent wear resistance. Summary of the invention

[0006] The present invention provides a UV ink resistant photosensitive elastomer prepolymer and a digital flexible resin plate thereof. By introducing relatively active terminal epoxy polybutadiene and terminal hydroxyl polybutadiene into the photosensitive elastomer prepolymer, the crosslinking degree of the photosensitive elastomer is effectively improved. When UV ink printing is performed, the embossed graphic part on the surface of the photosensitive elastomer is not easily corroded by the UV ink, and the highlight dots are not easily worn, so that the plate has good wear resistance.

[0007] In order to achieve the above technical purpose, the technical solution adopted by the present application is: UV-resistant ink photosensitive elastomer prepolymer, including the following substances in parts by weight:

[0008] Thermoplastic elastomer (A) 40-72 parts;

[0009] Liquid epoxy-terminated polybutadiene (B) 1-12 parts;

[0010] 10-32 parts of liquid hydroxyl-terminated polybutadiene (C);

[0011] Photopolymerization initiator or photopolymerization initiation system (D) 0.5-5 parts;

[0012] The structure of the liquid epoxy-terminated polybutadiene (B) is as follows:

[0013] R is a CH2 group; n represents the number of structural units of the group, which is a positive integer; x, y, and z represent the quantitative proportion of each unit structure in the group, and the sum of x, y, and z is equal to 100%;

[0014] The structure of liquid hydroxyl-terminated polybutadiene (C) is as follows:

[0015] Specifically:

[0016]

[0017] x′, y′, z′ represent the quantitative proportion of each unit structure in the group, and the sum of x′, y′, z′ is equal to 100%;

[0018] or

[0019] m represents the number of structural units of the group.

[0020] Furthermore, the molecular weight of the liquid epoxy-terminated polybutadiene (B) is in the range of 1000-9000.

[0021] Furthermore, the molecular weight of the liquid hydroxyl-terminated polybutadiene (C) is in the range of 1000-9000.

[0022] Furthermore, the thermoplastic elastomer (A) is a block-structured polymer, comprising two or more of vinyl monomers, butadiene monomers, isoprene monomers and acrylonitrile monomers in any weight ratio.

[0023] Furthermore, the photopolymerization initiator or the photopolymerization initiation system (D) is at least one of a cleavage-type free radical photoinitiator and a hydrogen abstraction-type free radical photoinitiator.

[0024] Furthermore, the cleavage-type free radical photoinitiator is an aryl alkyl ketone compound, and the hydrogen-abstracting free radical photoinitiator is benzophenone and its derivatives.

[0025] Furthermore, it also includes a functional UV monomer (E), wherein the functional UV monomer (E) contains at least one (meth)acrylate having an unsaturated double bond functional group.

[0026] Furthermore, the functional UV monomer (E) is used in an amount of 6-20 parts by weight.

[0027] Furthermore, it also includes an auxiliary agent (F); the auxiliary agent (F) is a dye, an antioxidant, a flame retardant, a thermal polymerization inhibitor, a light absorber, a release agent or a leveling agent.

[0028] Furthermore, the amount of the auxiliary agent (F) is 1-5 parts by weight.

[0029] Another object of the present application is to provide a digital flexible resin plate, comprising a support layer with an adhesive, and a photosensitive elastomer resin layer, a laser ablation black film layer and a protective film layer sequentially stacked on the support layer, wherein the photosensitive elastomer resin layer contains the aforementioned UV-resistant photosensitive elastomer prepolymer.

[0030] Beneficial Effects

[0031] The advantage of the present invention is that liquid polymer-terminated epoxy-based polybutadiene and liquid-terminated hydroxyl-based polybutadiene are introduced into the flexible resin plate photosensitive elastomer. The combined use of the two effectively improves the degree of chemical crosslinking of the photosensitive elastomer prepolymer, so that the network interweaving structure formed is relatively dense, which can resist the erosion caused by UV ink during the printing process, thereby making the plate have good wear resistance. DETAILED DESCRIPTION

[0032] The present invention is further described in detail based on specific implementations, but the present invention is not limited to the following implementations. Further explanation: technicians in the relevant field can make some non-essential improvements and optimization adjustments based on the content of the present invention.

[0033] Definition: Block-structured polymers are high molecular materials composed of two or more polymer segments with different properties connected by covalent bonds.

[0034] The present invention belongs to the technical field of flexible printing plates, and particularly refers to UV-resistant photosensitive elastomer prepolymers and digital flexible resin plates. By introducing liquid epoxy-terminated polybutadiene and hydroxy-terminated polybutadiene, the prepolymers give the relief image part excellent wear resistance, effectively improve the image surface quality, and improve the plate durability of the digital flexible resin plate.

[0035] The UV-resistant photosensitive elastomer prepolymer is characterized by comprising the following substances in parts by weight:

[0036] Thermoplastic elastomer (A) 40-72 parts;

[0037] Liquid epoxy-terminated polybutadiene (B) 1-12 parts;

[0038] 10-32 parts of liquid hydroxyl-terminated polybutadiene (C);

[0039] Photopolymerization initiator or photopolymerization initiation system (D) 0.5-5 parts.

[0040] The thermoplastic elastomer (A) is a polymer of block structure, and as the main resin of the photosensitive elastomer, it includes vinyl monomer, butadiene monomer, isoprene monomer, acrylonitrile monomer, etc. Specifically, it includes styrene-butadiene-styrene polymer, styrene-butadiene polymer, styrene-isoprene polymer, styrene-isoprene-styrene polymer, styrene-ethylene-butadiene-styrene polymer, styrene-butadiene-isoprene-styrene polymer, acrylonitrile-butadiene polymer, acrylonitrile-isoprene polymer, acrylonitrile-butadiene-styrene polymer, acrylonitrile-isoprene-styrene polymer, etc. Among them, from the viewpoints of the hardness of the UV ink-resistant digital flexible resin plate, the flexibility of the plate, and the overall stability, it is preferred to use known elastomers such as styrene-butadiene-styrene (SBS) polymer, styrene-isoprene-styrene (SIS) polymer, styrene-ethylene-butadiene-styrene (SEBS) polymer. The thermoplastic elastomer (A) styrene-butadiene-styrene (SBS) that can be used in the prepolymer of the present invention can be obtained commercially from SBS 3527 of Huanqiu Rubber Co., Ltd., SBSD1102 of Kraton Co., Ltd., and SBS YH-792E of Sinopec Hunan Petrochemical Co., Ltd.; styrene-isoprene-styrene (SIS) can be obtained from SISD1114, SISD1124, and SISD1119 of Kraton Co., Ltd., SIS YH-1106 of Baling Petrochemical Co., Ltd., and Quintac SIS 3450 of Zeon Co., Ltd. of Japan; styrene-ethylene-butadiene-styrene (SEBS) can be obtained from SEBS YH-511 of Baling Petrochemical Co., Ltd., SEBS 3150 of Taiwan Rubber Co., Ltd. of Taiwan, China, and SEBS1652 of Kraton Co., Ltd. of the United States. These polymers can be used alone or in combination of two or more.

[0041] The liquid epoxy-terminated polybutadiene (B) has the following structure:

[0042] R is a CH2 group; n represents the number of structural units of the group, which is a positive integer; x, V, and z represent the proportion of each unit structure in the group, and the sum of x, V, and z is equal to 100%;

[0043] Among them, the epoxy-terminated polybutadiene in the photosensitive elastomer prepolymer has strong polarity and reactivity, and contains active double bonds in the main chain, which can react with the active groups in the photosensitive elastomer to form strong chemical bonds with it, forming a cross-linked structure, thereby improving the strength and stability of the photosensitive elastomer. This enhanced strength and stability has a significant effect on improving the wear resistance of the plate. The formation of the cross-linked structure makes the surface of the plate more solid and less susceptible to wear and damage by external factors. In some embodiments, the molecular weight range of the liquid epoxy-terminated polybutadiene (B) is 1000-9000. It can be derived from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd.

[0044] The liquid hydroxyl-terminated polybutadiene (C) has the following structure:

[0045] Specifically:

[0046]

[0047] x', y', z' represent the quantitative proportion of each unit structure in the group, and the sum of x', y', z' is equal to 100%;

[0048] or

[0049] m represents the number of structural units of the group

[0050] Among them, the (liquid) terminal hydroxyl polybutadiene in the photosensitive elastomer prepolymer has a relatively long flexible chain segment, which can play a good lubricating role in the material, making the molecular chain easier to move, and can effectively reduce the internal friction of the material. Such a reduction in internal friction enables the plate to more effectively resist wear when subjected to external pressure or friction, thereby extending the service life of the plate. The introduction of terminal hydroxyl polybutadiene can undergo a chemical cross-linking reaction with the active groups in the photosensitive elastomer under the action of a photoinitiator. This reaction not only enhances the strength of the photosensitive elastomer itself, but also further improves the wear resistance of the plate. In some embodiments, the liquid terminal hydroxyl polybutadiene (C) has a molecular weight range of 1000-9000. It can be sourced from Nisso GI Japan Soda Co., Ltd. and HT Evonik Industries AG, Germany.

[0051] In addition, the epoxy-terminated polybutadiene (liquid epoxy-terminated polybutadiene (B)) and hydroxy-terminated polybutadiene (liquid hydroxy-terminated polybutadiene (C)) in the photosensitive elastomer prepolymer have good compatibility. When used together as plasticizers, they can perform a joint plasticizing effect and be inserted into the molecular chains of the main resin of the photosensitive elastomer to increase the distance between molecules, reduce the force between molecules, and increase the flexibility of the photosensitive elastomer. These have a significant positive impact on improving the wear resistance of the plate.

[0052] The photopolymerization initiator or photopolymerization initiation system (D) is at least one of a cleavage-type free radical photoinitiator and a hydrogen abstraction-type free radical photoinitiator.

[0053] Among them, the cleavage-type free radical photoinitiator is an aromatic alkyl ketone compound, including benzoin methyl ether, benzoin ethyl ether, benzoin dimethyl ketal, benzil, 1-hydroxy-cyclohexyl benzophenone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6(trimethylbenzoyl)diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxyphenylphosphine oxide, α-hydroxy ketone derivatives, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone, 2-benzyl-2-dimethylamine-1-(4-morpholinephenyl)-1-butanone, 1-hydroxycyclohexyl phenyl ketone, benzoin methyl ether, α,α'-diethoxyacetophenone, α,α'-dimethylbenzil ketal, methyl benzoylformate, methyl o-benzoylbenzoate, etc.

[0054] The hydrogen abstraction type free radical photoinitiator is benzophenone and its derivatives, including benzophenone, 2,4-diethylthioxanthone, 2-ethylanthraquinone (2-EA), thioxanthone, 4-methylbenzophenone, tetramethyl Michler's ketone, methylethyl Michler's ketone, 1-chloro-4-propoxythioxanthone, etc.

[0055] Based on the consideration of the chemical crosslinking of the photosensitive elastomer and the characteristics of UV ink resistance, the UV ink resistant photosensitive elastomer prepolymer also includes a functional UV monomer (E), and the functional UV monomer (E) contains at least one (meth) acrylate with an unsaturated double bond functional group. The specific UV monomer (E) can be ethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, dipropylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate, trimethylolpropane di ... trimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol tetraacrylate, diallyl phthalate, triallyl cyanate, dibutyl fumarate, diphenyl fumarate, dibutyl maleate, dioctyl maleate, N,N'-hexamethylenebisacrylamide, N,N'-hexamethylenebismethacrylamide, 4-morpholine acrylic acid, 2-N-morpholine methacrylate, isobornyl acrylate, isobornyl methacrylate, etc.

[0056] The UV monomer (E) can be used alone or in combination of two or more in any weight ratio. The amount of the functional UV monomer (E) is 6-20 parts by weight.

[0057] Based on the overall characteristics of the plate, the UV-resistant photosensitive elastomer prepolymer also includes an additive (F); the additive (F) is a dye, an antioxidant, a flame retardant, a thermal polymerization inhibitor, a light absorber, a release agent or a leveling agent. Red 335, Red 395, 346, Solvent Red 52, Red Base 543, Rhodamine Blue, Zhongxing Yellow KRL, Solvent Red 235, Solvent Orange 107, etc.; thermal polymerization inhibitors such as benzoquinone, hydroquinone, pyrogallol, pyrogallol, p-methoxyphenol, phenyl-α-naphthylamine, copper resinate, butylated hydroxytoluene, pyridine, nitrobenzene and dinitrobenzene, etc.; antioxidants such as 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-methylphenol, polymerized trimethyl dihydroquinone, 3,5-di-tert-butyl-4-hydroxybenzylbenzene, 2,2-methylene-bis-(4-methyl-6-tert-butylphenol), etc.; ultraviolet light absorbers such as 2-hydroxy- 4-dodecyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, salicylic acid-2-ethylhexyl ester, salicylic acid p-octylphenyl ester, salicylic acid-4-tert-butylphenyl ester, o-hydroxybenzoic acid phenyl ester, 2-hydroxy-4-n-octyloxybenzophenone, 2,2'-thiobis(4-tert-octylphenoloxy)nickel, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, etc. The auxiliary agent (F) is used in an amount of 1-5 parts by weight.

[0058] Another purpose of the present application is to obtain a digital flexible resin plate. The implementation method of the UV-resistant ink digital flexible resin plate consists of a four-layer structure, which is a support layer with an adhesive, a photosensitive elastic layer, a laser ablation black film layer, and a protective film layer. The four-layer structure is sequentially stacked on the support. The thickness of the support layer is preferably 75-200μm, the thickness of the laser ablation black film layer is preferably 0.5-5μm, and the thickness of the protective film layer is preferably 75-200μm; more preferably, the thickness of the support layer is 100-175μm, the thickness of the laser ablation black film layer is 1-2μm, and the thickness of the protective film layer is 100-175μm.

[0059] The preparation process of the digital flexible resin plate is to mix the photosensitive elastomer prepolymer containing the necessary components (A)-(E) at 90-150°C for 40-120min, preferably at a temperature of 110-130°C and for 60-100min, and pressurize and heat the photosensitive elastomer by a twin-screw extruder to tightly adhere the extruded photosensitive elastomer to the support layer with the adhesive, and at the same time, cover the other side with a protective film layer and a laser ablation black film layer.

[0060] The core technical principle of this application is that during the exposure process of the formed photosensitive elastomer, the active free radicals generated will attack the epoxy group on the terminal epoxy polybutadiene molecular chain. The epoxy group is a relatively active functional group, which is easily attacked by free radicals and undergoes a ring-opening reaction to form a new free radical intermediate. This process generates reactive sites on the terminal epoxy polybutadiene molecular chain. At the same time, the double bonds in its main chain can react with the thermoplastic elastomer polymer to form a cross-linked structure.

[0061] The hydroxyl groups at both ends of the hydroxy-terminated polybutadiene molecular chain in the formed photosensitive elastomer will also participate in the reaction. On the one hand, the hydroxyl groups can react with the active groups in the system; on the other hand, under the action of the active species generated by the photoinitiator, the hydroxyl groups can also undergo esterification reaction with the acrylate double bonds in the active monomer molecules.

[0062] The free radical intermediates generated after the ring opening of the terminal epoxy polybutadiene in the formed photosensitive elastomer, the active sites formed after the terminal hydroxyl polybutadiene participates in the reaction, and the polymer chains generated after the active monomers are polymerized will react with each other. These molecular chains are constantly connected to each other through chemical bonds, gradually forming a three-dimensional network cross-linked structure. For example, the free radicals after the ring opening of the terminal epoxy polybutadiene react with the active sites on the polymer chains after the active groups are polymerized; at the same time, the polymer chains after the active monomers are polymerized can also react with the terminal hydroxyl polybutadiene and the terminal epoxy polybutadiene.

[0063] Example 1

[0064] (1) Photosensitive elastomer prepolymer

[0065] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, Universal Rubber Co., Ltd., 35 parts; styrene-isoprene-styrene SIS YH-1106, China Petrochemical Group Baling Petrochemical Co., Ltd., 5 parts.

[0066] Liquid epoxy-terminated polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 10 parts.

[0067] Liquid hydroxyl-terminated polybutadiene (C) was Nisso GI-1000, Nippon Soda Co., Ltd., 25 parts.

[0068] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 2 parts; and benzophenone, from Jiuri New Materials Co., Ltd., is 1 part.

[0069] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 15 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 5 parts.

[0070] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 0.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 1.5 parts.

[0071] (2) Plate production

[0072] The photosensitive elastomer prepolymer is added into a high-speed mixing extruder in a corresponding proportion, melt-mixed under high temperature and pressure, mixed at 90-150°C for 40-120 minutes, and the photosensitive elastomer polymer is extruded and coated on a support with an adhesive using a twin-screw extruder (), the support is produced by Lucky Group Corporation, and at the same time, a laser ablation black film and a protective film are coated on the photosensitive elastomer, the protective film is produced by Lucky Group Corporation, formed into a sheet through a gap, and cut into a specified size after cooling to produce a digital flexible resin plate.

[0073] Example 2

[0074] (1) Photosensitive elastomer prepolymer

[0075] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, Global Rubber Co., Ltd., 45 parts.

[0076] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 12 parts.

[0077] Liquid hydroxyl-terminated polybutadiene (C) is HT, Evonik Industries AG, Germany, 23 copies.

[0078] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 0.3 parts; and thioxanthone, from Jiuri New Materials Co., Ltd., is 0.2 parts.

[0079] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 12 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 4 parts.

[0080] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 2.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 1.0 part.

[0081] (2) Plate production: Same as in Example 1.

[0082] Example 3

[0083] (1) Photosensitive elastomer prepolymer

[0084] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, Universal Rubber Co., Ltd., 40 parts; styrene-ethylene-butadiene-styrene SEBS1652, Kraton Company, USA, 10 parts.

[0085] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 6 parts.

[0086] Liquid hydroxyl-terminated polybutadiene (C) was Nisso GI-2000, Nippon Soda Co., Ltd., 32 parts.

[0087] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 0.5 part; and benzophenone, from Jiuri New Materials Co., Ltd., is 0.5 part.

[0088] UV monomer (E) was 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 10 parts.

[0089] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 0.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 0.5 parts.

[0090] (2) Plate production: Same as in Example 1.

[0091] Example 4

[0092] (1) Photosensitive elastomer prepolymer

[0093] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-isoprene-styrene SISYH-1106, Baling Petrochemical Company, 40 parts; styrene-ethylene-butadiene-styrene SEBS YH-511, Baling Petrochemical Company, 15 parts.

[0094] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 8 parts.

[0095] Liquid hydroxyl-terminated polybutadiene (C) was Nisso GI-3000, Nippon Soda Co., Ltd., 18 parts.

[0096] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 1.5 parts; and thioxanthone, from Jiuri New Materials Co., Ltd., is 0.5 parts.

[0097] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 9 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 4 parts.

[0098] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 3.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 0.5 parts.

[0099] (2) Plate production: Same as in Example 1.

[0100] Example 5

[0101] (1) Photosensitive elastomer prepolymer

[0102] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-isoprene-styrene SISYH-1106, Baling Petrochemical Company, 60 parts.

[0103] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 5 parts.

[0104] Liquid hydroxyl-terminated polybutadiene (C) is HT, Evonik Industries AG, Germany, 16 copies.

[0105] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 3.0 parts; and benzophenone, from Jiuri New Materials Co., Ltd., is 2.0 parts.

[0106] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 7 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 2 parts.

[0107] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 3.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 1.5 parts.

[0108] (2) Plate production: Same as in Example 1.

[0109] Example 6

[0110] (1) Photosensitive elastomer prepolymer

[0111] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, Global Rubber Co., Ltd., 40 parts; styrene-isoprene-styrene SISD1119, Kraton Company, 20 parts; styrene-ethylene-butadiene-styrene SEBS YH-511, Baling Petrochemical Company, 5 parts.

[0112] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 2.5 parts.

[0113] The liquid hydroxy-terminated polybutadiene (C) was Nisso GI-3000, Nippon Soda Co., Ltd., 10 parts.

[0114] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 1.0 part; and 4-methylbenzophenone, from Jiuri New Materials Co., Ltd., is 0.5 part.

[0115] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 12 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 6 parts.

[0116] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 1.0 part; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 2.0 part.

[0117] (2) Plate production: Same as in Example 1.

[0118] Example 7

[0119] (1) Photosensitive elastomer prepolymer

[0120] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-ethylene-butadiene-styrene SEBS YH-511, Baling Petrochemical Company, 40 parts; styrene-isoprene-styrene SISD1119, Kraton Company, 32 parts.

[0121] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 1.0 part.

[0122] The liquid hydroxy-terminated polybutadiene (C) was Nisso GI-1000, Nippon Soda Co., Ltd., 14.5 parts.

[0123] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 1.0 part; and benzophenone, from Jiuri New Materials Co., Ltd., is 3.0 parts.

[0124] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 2 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 4 parts.

[0125] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 0.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 2.0 parts.

[0126] (2) Plate production: Same as in Example 1.

[0127] Comparative Example 1

[0128] (1) Photosensitive elastomer prepolymer

[0129] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-isoprene-styrene SISD1119, Kraton Company, 55 parts.

[0130] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 12 parts.

[0131] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 2.0 parts; and benzophenone, from Jiuri New Materials Co., Ltd., is 0.5 parts.

[0132] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 20 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 9 parts.

[0133] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 0.5 part; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 1.0 part.

[0134] (2) Plate production

[0135] The photosensitive elastomer prepolymer is added into a high-speed mixing extruder in a corresponding proportion, melt-mixed under high temperature and pressure, mixed at 90-150°C for 40-120 minutes, and the photosensitive elastomer polymer is extruded and coated on a support with an adhesive (100-175 μm) using a twin-screw extruder. The support is produced by Lucky Group Corporation. At the same time, a laser ablation black film and a protective film are coated on the photosensitive elastomer. The protective film is produced by Lucky Group Corporation, formed into a sheet through a gap, and cut into a specified size after cooling to produce a digital flexible resin plate.

[0136] Comparative Example 2

[0137] (1) Photosensitive elastomer prepolymer

[0138] The thermoplastic elastomer (A) in the UV-resistant photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, produced by Global Rubber Co., Ltd., 60 parts.

[0139] Liquid hydroxyl-terminated polybutadiene (C) is HT, Evonik Industries AG, Germany, 20 copies.

[0140] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 1.5 parts; and benzophenone, from Jiuri New Materials Co., Ltd., is 2.0 parts.

[0141] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 7 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 7 parts.

[0142] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 1.5 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 1.0 parts.

[0143] (2) Plate production: Same as control example 1.

[0144] Comparative Example 3

[0145] (1) Photosensitive elastomer prepolymer

[0146] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, produced by Global Rubber Co., Ltd., 45 parts; styrene-isoprene-styrene SISD1119, produced by Kraton, 20 parts.

[0147] Liquid terminated epoxy polybutadiene (B) was from Tianyuan Aerospace Materials (Yingkou) Technology Co., Ltd., 10 parts.

[0148] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 1.0 part; and benzophenone, from Jiuri New Materials Co., Ltd., is 1.0 part.

[0149] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 12 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 7 parts.

[0150] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 2.0 parts; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 2.0 parts.

[0151] (2) Plate production: Same as control example 1.

[0152] Comparative Example 4

[0153] (1) Photosensitive elastomer prepolymer

[0154] The thermoplastic elastomer (A) in the UV-resistant ink photosensitive elastomer prepolymer is styrene-butadiene-styrene SBS3527, Global Rubber Co., Ltd., 35 parts; styrene-isoprene-styrene SISD1119, Kraton Company, 25 parts; styrene-ethylene-butadiene-styrene SEBS YH-511, Baling Petrochemical Company, 10 parts.

[0155] The liquid hydroxy-terminated polybutadiene (C) was Nisso GI-1000, Nippon Soda Co., Ltd., 10 parts.

[0156] The photopolymerization initiator or photopolymerization initiation system (D) is a mixture, wherein 1-hydroxy-cyclohexyl benzophenone (IRGACURE 184), from BASF, is 0.5 part; and benzophenone, from Jiuri New Materials Co., Ltd., is 0.5 part.

[0157] UV monomer (E) is 1,6-hexanediol diacrylate (HDDA), Tianjin Tianjiao Chemical Co., Ltd., 10 parts; tricyclodecane dimethanol diacrylate (DCPDA), Shanghai Yiqing Trading Co., Ltd., 6 parts.

[0158] The auxiliary agent (F) includes a dye and an antioxidant, wherein the dye is Red 335, BASF, 1.0 part; antioxidant is 2,6-di-tert-butyl-p-cresol, Nanjing Huali Mingke Industry and Trade Co., Ltd., 2.0 part.

[0159] (2) Plate production: Same as control example 1.

[0160] The test method of the wear resistance of the digital flexible resin plate of the present invention is as follows:

[0161] Plate making process: Cut A4-sized UV-resistant plates, use the Gulongyan Concept 305ECDLF platemaking machine for back exposure, then remove the protective film on the surface of the plate, use the CRON HDI-900S laser engraving machine to laser engrave the laser-ablated black film layer of the plate, and then continue to use the Gulongyan Concept 305ECDLF platemaking machine to perform positive exposure on the laser-engraved plate, with a main exposure time of 10 minutes.

[0162] Plate development process: The exposed plate is washed with environmentally friendly developer on the Gulongyan Concept 305DW flexographic plate washing machine, developed for 5 minutes, dried at 60°C for 2 hours, and then the surface is cured under ultraviolet light for 5 minutes to obtain the digital flexible resin plate used for printing.

[0163] Plate wear resistance process: Cut the prepared plate into 5cm*5cm samples, soak them in UV ink and varnish for 10h (temperature 20-25℃, humidity 50%), wipe the plate surface clean after taking it out, and use Taber wear tester to test the wear resistance of the solid part of the plate surface, and measure the wear amount (mg / cm 2 ), it should be explained here that the above-mentioned wear amount mainly refers to the mass (mg) reduced by the plate during the wear process on the Taber wear tester and the contact area (cm 2 ) ratio.

[0164] When the plate wear is less than 5.0mg / cm 2When printing, the UV-resistant ink plate has good wear resistance.

[0165] The wear resistance of the digital flexible resin plate is shown in Table 1 below, where abrasion 1 refers to the abrasion measured after the plate is immersed in Brett UV ink for 10 hours (temperature 20-25°C, humidity 50%), and abrasion 2 refers to the abrasion measured after the plate is immersed in Cainuo UV varnish for 10 hours (temperature 20-25°C, humidity 50%).

[0166] Table 1 Comparison of plate wear performance between the embodiment and the control example

[0167]

[0168] It can be seen from Table 1 above that the digital flexible resin plates selected from Examples 1 to 7 produced by the present invention have excellent wear resistance.

Claims

1. UV-resistant photosensitive elastomer prepolymer, characterized in that: The following materials are included in parts by weight: Thermoplastic elastomer (A) 40-72 parts; Liquid epoxy-terminated polybutadiene (B) 1-12 parts; 10-32 parts of liquid hydroxyl-terminated polybutadiene (C); Photopolymerization initiator or photopolymerization initiation system (D) 0.5-5 parts; The structure of the liquid epoxy-terminated polybutadiene (B) is as follows: R is a CH2 group; n represents the number of structural units of the group, which is a positive integer; x, y, and z represent the quantitative proportion of each unit structure in the group, and the sum of x, y, and z is equal to 100%; The structure of liquid hydroxyl-terminated polybutadiene (C) is as follows: Specifically: x', y', z' represent the quantitative proportion of each unit structure in the group, and the sum of x', y', z' is equal to 100%; or m represents the number of structural units of the group.

2. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The molecular weight of the liquid epoxy-terminated polybutadiene (B) is in the range of 1000-9000.

3. The UV-resistant photosensitive elastomer prepolymer according to claim 1, characterized in that: The molecular weight of the liquid hydroxyl-terminated polybutadiene (C) is in the range of 1000-9000.

4. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The thermoplastic elastomer (A) is a block structure polymer, which contains two or more of vinyl monomers, butadiene monomers, isoprene monomers and acrylonitrile monomers in any weight ratio.

5. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The photopolymerization initiator or photopolymerization initiation system (D) is at least one of a cleavage-type free radical photoinitiator and a hydrogen abstraction-type free radical photoinitiator.

6. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1 or 5, characterized in that: The cleavage-type free radical photoinitiator is an aryl alkyl ketone compound, and the hydrogen-abstracting free radical photoinitiator is benzophenone and its derivatives.

7. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The invention also comprises a functional UV monomer (E), wherein the functional UV monomer (E) contains at least one (meth)acrylate having an unsaturated double bond functional group; the amount of the functional UV monomer (E) is 6-20 parts by weight.

8. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The invention also comprises an auxiliary agent (F); the auxiliary agent (F) is a dye, an antioxidant, a flame retardant, a thermal polymerization inhibitor, a light absorber, a release agent or a leveling agent.

9. The UV-resistant ink photosensitive elastomer prepolymer according to claim 1, characterized in that: The amount of the auxiliary agent (F) is 1-5 parts by weight.

10. Digital flexible resin plate, characterized by: It has a support layer with an adhesive, and a photosensitive elastomer resin layer, a laser ablation black film layer and a protective film layer stacked in sequence on the support layer, and the photosensitive elastomer resin layer contains the UV-resistant photosensitive elastomer prepolymer described in any one of claims 1-9.

Images