Epoxy-modified photocurable polyacrylate dispersions, methods for their preparation and use

Abstract

The application belongs to the technical field of coatings, and discloses an epoxy-modified photocuring polyacrylate dispersion, a preparation method and application thereof.The preparation raw materials of the epoxy-modified photocuring polyacrylate dispersion include acrylic acid monomers, acrylic ester monomers, an initiator, isocyanate monomers, hydroxyl vinyl ether, a bio-based material, a hydrophilic modifier, an epoxy resin, an acrylamide monomer and a neutralizing agent.The solid content of the epoxy-modified photocuring polyacrylate dispersion is 38-41%.The bio-based content of the epoxy-modified photocuring polyacrylate dispersion is greater than or equal to 15%.The particle size of the epoxy-modified photocuring polyacrylate dispersion is less than 110 nm.The water-based photocuring bio-based coating prepared from the epoxy-modified photocuring polyacrylate dispersion has the characteristics of high flexibility, good chemical resistance, excellent adhesion to various substrates and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coatings, and particularly relates to an epoxy-modified photocurable polyacrylate dispersion, a preparation method and application thereof. BACKGROUND

[0002] Water-based coatings gradually become the mainstream choice in the coating market due to its environmental protection, safety, excellent construction performance and wide applicability. Water-based coatings mainly include water-based single-component coatings, water-based two-component coatings, and water-based photocurable coatings which have rapidly developed in recent years. The film performance of single-component water-based coatings, such as water resistance, chemical resistance and hardness, is greatly different from that of solvent-based coatings, which seriously limits the popularization and application of water-based coatings. The mechanical properties, water resistance and chemical resistance of two-component water-based coatings are close to those of solvent-based coatings, but due to the problem of activation period, they are not suitable for reciprocating mechanical spraying and electrostatic spraying, and their drying speed is slow, which affects the construction efficiency. The film mechanical properties, water resistance and chemical resistance of water-based photocurable coatings are superior to those of solvent-based products. The water-based photocurable coatings are single-component packaging, which can be used immediately after opening the barrel, and do not have an activation period, so they are suitable for various mechanical spraying. After construction, they can be cured by a UV curing machine for 0.5-2 hours and then packed offline. In the future, water-based photocurable coatings will replace two-component water-based coatings and become the first choice for high-end water-based coatings. At present, the main products in the market are free radical photocurable polyurethane dispersions, which are mainly prepared by capping polyurethane prepolymer with hydroxyl-containing acrylic monomers. The capping process limits the molecular weight of the prepolymer, and the double bonds are only at both ends of the polymer. This process feature causes the products on the market to have the problems of poor storage stability and low reactivity. In addition, the film of the free radical photocurable coating has a large shrinkage rate and poor adhesion to many substrates. The above shortcomings greatly limit the popularization and application of water-based photocurable coatings, and therefore need to be developed.

[0003] Therefore, it is urgent to provide a water-based photocurable resin with good adhesion for developing water-based photocurable coatings. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an epoxy-modified photocurable polyacrylate dispersion, a preparation method and application thereof. The present application introduces a cationic photocuring system and an epoxy group into the photocurable water-based resin, which reduces the film shrinkage rate and improves the adhesion of the film to various substrates. The film of the water-based photocurable bio-based coating prepared by the present application has the advantages of high gloss, high transparency, excellent water resistance and chemical resistance, high crosslinking density, high flexibility and excellent adhesion to various substrates.

[0005] The present application also provides an epoxy-modified photocurable polyacrylate dispersion.

[0006] The present application also provides a water-based bio-based photocurable coating.

[0007] The application also provides application of the aqueous bio-based photocuring coating in the field of wood product preparation, automobile manufacturing or metal product corrosion prevention.

[0008] The first aspect of the application provides a preparation method of an epoxy-modified photocuring polyacrylate dispersion, and the preparation method comprises the following steps:

[0009] S1. Mixing acrylic monomers, acrylate monomers, vinyl monomers and initiators to obtain a mixed solution A;

[0010] S2. Mixing and reacting diisocyanate and hydroxy vinyl ether to obtain a prepolymer B containing vinyl and isocyanate groups;

[0011] S3. Mixing and reacting a bio-based material and a hydrophilic modifier to obtain a hydrophilic modified bio-based material C;

[0012] S4. Mixing and reacting an epoxy resin and a hydrophilic modifier to obtain a prepolymer D;

[0013] S5. Mixing a blocked cationic thermal initiator, a cationic photoinitiator and a free radical photoinitiator to form a mixture E;

[0014] S6. Dispersing and reacting the hydrophilic modified bio-based material C, a polymerization inhibitor, an acrylamide monomer, the prepolymer B, the prepolymer D, the mixture E and a neutralizing agent to obtain an epoxy-modified photocuring polyacrylate dispersion;

[0015] The bio-based material is a vegetable oil containing three or more epoxy groups.

[0016] The hydrophilic modifier is a monomer containing one secondary amino group and one sulfonic acid group.

[0017] The epoxy resin is an epoxy resin containing three or more epoxy groups.

[0018] The neutralizing agent is a tertiary amine.

[0019] The hydrophilic modifier in step S3 and step S4 is the same or different.

[0020] The embodiments according to the first aspect of the application have at least the following beneficial effects:

[0021] The present application provides an epoxy-modified photocuring polyacrylate dispersion and a preparation method thereof. The photocuring water-based resin is introduced with a cationic photocuring system and an epoxy group, which reduces the shrinkage of the paint film and improves the adhesion of the paint film on various substrates. The modified epoxy resin and the polyacrylate prepolymer are mixed and then dispersed together. The molecular weight of the modified epoxy resin is smaller than that of the polyacrylate prepolymer, and the viscosity is low, so the viscosity of the polyacrylate prepolymer can be reduced and the dispersion stability can be improved. The proportion of the secondary amine group generated by the reaction of isocyanate group and hydroxyl group and the epoxy group of the epoxy resin is controlled to ensure the storage stability of the dispersion. The closed cationic thermal initiator, the cationic photoinitiator and the free radical photoinitiator are dispersed together with the resin, which can further improve the reaction degree of the photocuring group and thus improve the film resistance. The addition of the closed cationic thermal initiator can provide another curing method for the film curing while ensuring the storage stability. The epoxy resin and the polyacrylate resin are both hydrophilically modified in the present application, which can make the mixture more uniform and thus improve the film performance. If the epoxy resin is not hydrophilically modified, a core-shell structure will be formed, the shell layer is hydrophilic polyacrylate, and the core layer is epoxy resin. The two-phase separation will cause poor film transparency and other poor performance.

[0022] In another aspect, the present application provides a water-based photocuring bio-based coating and a preparation method thereof. The paint film of the water-based photocuring bio-based coating has the advantages of high gloss, high transparency, excellent water resistance and chemical resistance, high crosslinking density, high flexibility, excellent adhesion to various substrates, etc., and can be applied to high-grade wood coating, automobile coating, metal anticorrosion coating and other industrial protective coating.

[0023] In the present application, the groups that can participate in photocuring include vinyl ether double bonds, acryloyloxy double bonds and epoxy groups. The free radical photoinitiator can initiate the polymerization of acryloyloxy double bonds, and the cationic photoinitiator can initiate the polymerization of vinyl ether double bonds and epoxy groups. When both types of photoinitiators are added, the above groups can copolymerize. The polymerization initiated by the free radical photoinitiator has a large shrinkage, obvious oxygen inhibition and poor adhesion to many substrates, while the polymerization initiated by the cationic photoinitiator has a small shrinkage, no oxygen inhibition and excellent adhesion to many substrates, which can fully compensate for the shortcomings of free radical photocuring.

[0024] In addition, conventional water-based photocuring coatings only add photoinitiators during the preparation of the coating, which has the disadvantage that the internal photocuring groups of the latex particles cannot fully react. In the present application, the closed cationic thermal initiator, the cationic photoinitiator and the free radical photoinitiator are dispersed together with the resin. This part of the initiator can make the photocuring groups inside the latex particles react more fully. The initiator added during the preparation of the coating can initiate the polymerization of the photocuring groups at the interface of the latex particles, which can further improve the reaction degree of the photocuring groups and thus improve the film resistance.

[0025] Third, the addition of a blocked cationic thermal initiator can provide another curing method for the paint film while ensuring storage stability. When the water-based photocurable coating is a solid color coating, the ultraviolet light cannot penetrate the paint film, resulting in the bottom layer of the paint film being unable to cure. The paint film with the addition of a blocked cationic thermal initiator can be cured by baking, which can make the bottom layer of the paint film cured. Some wood has a high oil content, such as pine, and the oil will come out of the substrate during baking, causing paint film defects such as blistering. Since such oils contain many double bonds and epoxy groups, the blocked cationic thermal initiator can initiate the curing of the oil during baking, thereby avoiding paint film defects.

[0026] In some embodiments of the present application, the preparation method comprises the following steps:

[0027] S1. Mix 1.5-2.5 parts by mass of acrylic monomer, 20-30 parts by mass of acrylic ester monomer, 5-11 parts by mass of vinyl monomer, and 0.4-0.6 parts by mass of initiator to form a mixed solution A;

[0028] S2. Heat 8-15 parts by mass of diisocyanate to 50-70°C, then drop 5-9 parts by mass of hydroxy vinyl ether, and continue to react for 0.8-1.5 hours to obtain a prepolymer B containing vinyl and isocyanate groups;

[0029] S3. Heat 18-26 parts by mass of bio-based material to 55-75°C, add 5-6 parts by mass of hydrophilic modifier, and react to obtain a hydrophilic modified bio-based material C;

[0030] S4. Mix 10-25 parts by mass of epoxy resin and 10-15 parts by mass of hydrophilic modifier, control the reaction temperature to be 40-45°C, and react to form a prepolymer D;

[0031] S5. Mix 0.3-0.5 parts by mass of blocked cationic thermal initiator, 0.3-0.6 parts by mass of cationic photoinitiator, and 0.3-0.5 parts by mass of free radical photoinitiator to form a mixture E;

[0032] S6. Heat the hydrophilic modified bio-based material C to 130-150°C, then drop the mixed solution A in 3-4 hours, stir and keep warm for 20-40 minutes after dropping, cool to 60-80°C, add 0.01 parts by mass of polymerization inhibitor MEHQ, add 6-10 parts by mass of acrylamide monomer, continue to react for 30-60 minutes, cool to 45-55°C, add the prepolymer B containing vinyl and isocyanate groups, continue to react for 30-40 minutes, add the prepolymer D, stir for 5-10 minutes, then add the mixture E, stir for 3-5 minutes, then add 5-8 parts by mass of neutralizing agent, stir for 3-5 minutes, then add 180-210 parts by mass of deionized water and disperse for 10-20 minutes, filter the product to obtain an epoxy modified photocurable polyacrylate dispersion.

[0033] In some embodiments of the present invention, the preparation method comprises the following steps:

[0034] S1. In parts by mass, 1.5 to 2.5 parts of acrylic acid monomer, 20 to 30 parts of acrylate monomer, 5 to 11 parts of vinyl monomer, and 0.4 to 0.6 parts of initiator are mixed to form a mixed solution A;

[0035] S2. When 8 to 15 parts of diisocyanate are heated to 50 to 70 ° C, 5 to 9 parts of hydroxy vinyl ether are added dropwise at a constant pressure within 15 to 30 minutes, and the reaction is continued for 0.8 to 1.5 hours to obtain a prepolymer containing vinyl and isocyanate groups B;

[0036] S3. In parts by mass, 18 to 26 parts of the bio-based material are heated to 55 to 75 ° C, 5 to 6 parts of a hydrophilic modifier are added, and the reaction is carried out for 30 to 90 minutes to obtain a hydrophilically modified bio-based material C;

[0037] S4. In parts by mass, 10 to 25 parts of an epoxy resin and 10 to 15 parts of a hydrophilic modifier are mixed, the reaction temperature is controlled to 40 to 45 ° C, and the reaction is carried out for 1.5 to 2 hours to form a prepolymer D;

[0038] S5. In parts by mass, 0.3 to 0.5 parts of a blocked cationic thermal initiator, 0.3 to 0.6 parts of a cationic photoinitiator, and 0.3 to 0.5 parts of a free radical photoinitiator are mixed to form a mixture E;

[0039] S6. In parts by mass, when the hydrophilic modified bio-based material C is heated to 130-150°C, the mixed solution A is added dropwise within 3-4 hours. After the addition is completed, the mixture is stirred and kept warm for 20-40 minutes. The temperature is lowered to 60-80°C, 0.01 parts of polymerization inhibitor MEHQ are added, 6-10 parts of acrylamide monomer are added, the reaction is continued for 30-60 minutes, the temperature is lowered to 45-55°C, prepolymer B containing vinyl and isocyanate groups is added, the reaction is continued for 30-40 minutes, prepolymer D is added, and the mixture E is added after stirring for 5-10 minutes. After stirring for 3-5 minutes, 5-8 parts of neutralizer are added. After stirring for 3-5 minutes, 180-210 parts of deionized water are added and dispersed for 10-20 minutes. The material is filtered to obtain an epoxy-modified light-curing polyacrylate dispersion.

[0040] In some embodiments of the present invention, the acrylic acid monomer includes acrylic acid AA or methacrylic acid MAA;

[0041] In some embodiments of the present invention, the acrylate monomer includes an acrylate monomer and a methacrylate monomer.

[0042] In some embodiments of the present application, the methacrylate monomer includes at least one of methyl methacrylate MMA, butyl acrylate BA, isobornyl acrylate IBOA, cyclohexyl methacrylate CHMA, and benzyl methacrylate BZMA.

[0043] In some embodiments of the present application, the vinyl monomer includes at least one of styrene St and vinyl acetate VAc.

[0044] In some embodiments of the present application, the diisocyanate monomer includes at least one of isophorone diisocyanate IPDI, toluene diisocyanate TDI, hexamethylene diisocyanate HDI, diphenylmethane diisocyanate MDI, and 4,4'-dicyclohexylmethane diisocyanate HMDI.

[0045] In some embodiments of the present application, the initiator includes at least one of di-tert-amyl peroxide and di-tert-butyl peroxide.

[0046] In some embodiments of the present application, the hydroxyl vinyl ether includes at least one of 4-hydroxybutyl vinyl ether, triethylene glycol divinyl ether, and cyclohexyl-1,4-dimethanol monovinyl ether.

[0047] In some embodiments of the present application, the epoxy resin includes at least one of tetraglycidyl diaminodimethylene benzene, 4,5-epoxytetrahydrophthalic acid diglycidyl ester, and triglycidyl-p-aminophenol.

[0048] In some embodiments of the present application, the bio-based material includes at least one of Special Epoxy Soybean Oil GreenSoft D, Special Epoxy Soybean Oil GreenSoft H, and Epoxy Linseed Oil 9-5 TM .

[0049] In some embodiments of the present application, the hydrophilic modifier includes at least one of cyclohexylaminoethanesulfonic acid CHES, cyclohexylaminopropanesulfonic acid CAPS, and cyclohexylaminobutanesulfonic acid CABS.

[0050] In some embodiments of the present application, the blocked cationic thermal initiator includes a blocked phosphate cationic thermal initiator.

[0051] In some embodiments of the present application, the blocked cationic thermal initiator includes at least one of Vicbase TC3631, CTI-100, CTI-200, and CTI-300.

[0052] In some embodiments of the present application, the cationic photoinitiator comprises at least one of HRcure-9387, HRcure-9392, HRcure-9388, HRcure-262, HRcure-261, HRcure-6992, HRcure-6976, and Omnirad 250.

[0053] In some embodiments of the present application, the radical photoinitiator comprises at least one of Darocur 1173, Irgacure 2959, Irgacure 500, Lucirin TPO-L, and Irgacure 819-DW.

[0054] In some embodiments of the present application, the acrylamide-based monomer comprises at least one of diacetone acrylamide (DAAM), N-butoxymethyl acrylamide, and hydroxyethyl acrylamide.

[0055] In some embodiments of the present application, the sulfonic acid-based neutralizer comprises at least one of triethylamine (TEA) and N,N-dimethylcyclohexylamine (DMCHA).

[0056] The second aspect of the present application provides an epoxy-modified photocurable polyacrylate dispersion prepared by the preparation method, wherein the epoxy-modified photocurable polyacrylate dispersion has a bio-based content of ≥15%, a pH of 6-7, a particle size of <110 nm, and a solid content of 38-41%.

[0057] The epoxy-modified polyacrylate dispersion has a bio-based content of ≥15%, a pH of 6-7, and a particle size of <110 nm, which can improve the appearance of the dispersion to achieve a semi-transparent effect. The epoxy-modified photocurable polyacrylate dispersion prepared by the preparation method has a large molecular weight, a high bio-based content, good storage stability, a good appearance, high reactivity, good resistance, excellent adhesion to various substrates, and the like. The preparation method has the advantages of simple operation, easy control, and low cost, and can be used to batch prepare the epoxy-modified photocurable polyacrylate dispersion.

[0058] The third aspect of the present application provides a water-based bio-based photocurable coating, and the preparation raw materials comprise the epoxy-modified photocurable polyacrylate dispersion.

[0059] In some embodiments of the present application, the preparation raw materials comprise the following weight fractions by weight parts:

[0060]

[0061] In some embodiments of the present application, the preparation raw materials comprise the following weight fractions by weight parts:

[0062]

[0063] In some embodiments of the present application, the free radical photoinitiator includes at least one of Darocur 1173, Irgacure 2959, Irgacure 500, Lucirin TPO-L, and Irgacure 819-DW.

[0064] In some embodiments of the present application, the cationic photoinitiator includes at least one of HRcure-9387, HRcure-9392, HRcure-9388, HRcure-262, HRcure-261, HRcure-6992, HRcure-6976, and Omnirad 250.

[0065] In some embodiments of the present application, the film forming aid includes at least one of propylene glycol methyl ether PM, propylene glycol n-butyl ether PnB, dipropylene glycol methyl ether, and DPM dipropylene glycol n-butyl ether DPnB.

[0066] In some embodiments of the present application, the dispersant includes at least one of DISPERBYK-191 and DISPERS 755W.

[0067] In some embodiments of the present application, the titanium white powder includes at least one of NTR-606 and Ti-Pure R-902+.

[0068] In some embodiments of the present application, the defoaming agent includes at least one of polyether siloxane copolymer defoaming agent and modified polysiloxane copolymer solution.

[0069] In some embodiments of the present application, the polyether siloxane copolymer defoaming agent includes TEGO-800, TEGO-805, TEGO-815, TEGO-825.

[0070] In some embodiments of the present application, the modified polysiloxane copolymer solution includes at least one of BYK-019 and BYK-020.

[0071] In some embodiments of the present application, the thickening agent includes at least one of nonionic polyurethane associative thickener, hydrophobically modified alkali-swellable associative thickener, alkali-swellable non-associative thickener, and nonionic associative thickener.

[0072] In some embodiments of the present application, the nonionic polyurethane associative thickener includes RM-8W.

[0073] In some embodiments of the present application, the hydrophobically modified alkali-swellable associative thickener comprises TT-935.

[0074] In some embodiments of the present application, the alkali-swellable non-associative thickener comprises ASE-60.

[0075] In some embodiments of the present application, the non-ionic associative thickener comprises at least one of TEGO ViscoPlus 3000, TEGO ViscoPlus 3030, and TEGO ViscoPlus 3060.

[0076] In some embodiments of the present application, the wetting agent comprises at least one of a polyether siloxane copolymer, a non-ionic organic surfactant, and a polyether modified polysiloxane solution.

[0077] In some embodiments of the present application, the polyether siloxane copolymer comprises TEGO-245.

[0078] In some embodiments of the present application, the non-ionic organic surfactant comprises TEGO-500.

[0079] In some embodiments of the present application, the polyether modified polysiloxane solution comprises BYK-346.

[0080] In some embodiments of the present application, the method for preparing the water-based photocurable bio-based coating comprises adding water and a film-forming aid into an epoxy-modified photocurable polyacrylate dispersion, and then sequentially adding a dispersant, titanium white, a photoinitiator, an antifoaming agent, a thickener, and a wetting agent, dispersing for 10-30 minutes, and filtering to obtain the water-based photocurable bio-based coating.

[0081] The paint film of the water-based photocurable bio-based coating obtained by the present application has the advantages of high gloss, high transparency, excellent water and chemical resistance, high crosslinking density, good flexibility, excellent adhesion to various substrates, etc., and can be applied to high-grade wood coating, automobile coating, metal anticorrosive coating, and other industrial protective coating.

[0082] The fourth aspect of the present application provides an application of the water-based bio-based photocurable coating in the field of wood product preparation, automobile manufacturing, or metal product corrosion prevention. DETAILED DESCRIPTION

[0083] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are given for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0084] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0085] The acrylic monomer used in the following examples is Acrylic Acid AA or Methacrylic Acid MAA from Sanmu Company;

[0086] The (meth)acrylate monomer is Methyl Methacrylate MAA, Butyl Acrylate BA, Isobornyl Acrylate IBOA, Cyclohexyl Methacrylate CHMA and / or Benzyl Methacrylate BZMA from Sanmu Company; the vinyl monomer is Styrene St or Vinyl Acetate VAc from Sanmu Company;

[0087] The initiator is Di-t-amyl peroxide DTAP or Di-t-butyl peroxide DTBP from Jinjinle Company;

[0088] The diisocyanate monomer is Isophorone Diisocyanate IPDI, Toluene Diisocyanate TDI, Hexamethylene Diisocyanate HDI, Diphenylmethane Diisocyanate MDI, 4,4'-Dicyclohexylmethane Diisocyanate HMDI from Wanhua Company;

[0089] The hydroxyl vinyl ether is 4-Hydroxybutyl Vinyl Ether HBVE, Triethylene Glycol Divinyl Ether DVE, Cyclohexyl-1,4-Dimethanol Monovinyl Ether;

[0090] The bio-based material is Special Epoxy Soybean Oil GreenSoft D, Special Epoxy Soybean Oil GreenSoft H, Epoxy Linseed Oil from Xingbang High Polymer Materials Co., Ltd. 9-5 TM ;

[0091] The hydrophilic modifier is Cyclohexylaminoethanesulfonic Acid CHES, Cyclohexylaminopropanesulfonic Acid CAPS or Cyclohexylaminobutanesulfonic Acid CABS from Aldrin Company;

[0092] The epoxy resin is Tetraglycidyl Diaminodimethylene Benzene MF-4101, 4,5-Epoxy Tetrahydrophthalic Acid Diglycidyl Ester MF-3286 Triglycidyl-p-Aminophenol MF-3102 from Hubei Zhenzhengfeng New Material Co., Ltd.

[0093] The blocked cationic thermal initiator is CTI-100, CTI-200, CTI-300 from Shenzhen Youyang Company or Vicbase TC3631 from Shenzhen City Kaigi Application Material Co., Ltd.

[0094] The initiation temperature of the blocked cationic thermal initiator is 70-100℃.

[0095] Cationic photoinitiator is HRcure-9387, HRcure-9392, HRcure-9388, HRcure-262, HRcure-261, HRcure-6992, HRcure-6976 of HUARUN Hengtong Company or Omnirad 250 of IGM Company;

[0096] Radical photoinitiator is Darocur 1173, Irgacure 2959, Irgacure 500, Lucirin TPO-L, Irgacure 819-DW of IGM Company;

[0097] Acrylamide monomer is diacetone acrylamide DAAM, N-butoxymethyl acrylamide or hydroxyethyl acrylamide;

[0098] Sulfonic acid neutralizer is triethylamine TEA or N,N-dimethylcyclohexylamine DMCHA of Dow Chemical Company.

[0099] Basic performance test includes: the cationic photocurable bio-based polyurethane dispersion is tested according to GB / T11175-2002 “Synthetic resin emulsion test method”, and the appearance, pH, solid content, viscosity of the emulsion are tested. The average particle size of the dispersion is determined by a nano particle size analyzer (ZS Nano S). The double bond and epoxy group concentration is obtained by theoretical calculation, and the double bond and epoxy group concentration is the ratio of the amount of substance of double bond or epoxy group to the mass of emulsion or coating solid, with the unit of mol / 100g.

[0100] Example 1

[0101] An epoxy-modified photocurable polyacrylate dispersion 1 is prepared by the following steps:

[0102] S1. 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP are uniformly mixed to form a mixed solution A1, which is ready for use;

[0103] S2. 11.1 parts of isophorone diisocyanate IPDI is heated to 50°C, and 6.6 parts of triethylene glycol divinyl ether DVE is added at a constant pressure within 15 minutes, and the reaction is continued for 1 hour to obtain a prepolymer B1 containing vinyl and isocyanate groups, which is ready for use;

[0104] S3. In a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, 25.2 parts of special epoxy soybean oil GreenSoft D was added, stirred and heated, the temperature was raised to 73°C, 5.5 parts of cyclohexylaminopropyl sulfonic acid CAPS was added, and the reaction was carried out for 75 minutes to obtain a hydrophilically modified bio-based material C1, which was ready for use;

[0105] S4. In mass parts, 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropyl sulfonic acid CAPS were mixed uniformly, the reaction temperature was controlled at 40°C, and the reaction was carried out for 1.5 hours to form a prepolymer D1, which was ready for use;

[0106] S5. In mass parts, 0.4 parts of a blocked cationic thermal initiator CTI-100, 0.5 parts of a cationic photoinitiator HRcure-9387 and 0.4 parts of a free radical photoinitiator Darocur 1173 were mixed uniformly to form a mixture E1, which was ready for use;

[0107] S6. In mass parts, the hydrophilically modified bio-based material C1 was added dropwise into the mixed solution A1 at a constant pressure within 4 hours when heated to 150°C, and after the dropwise addition was completed, the mixture was stirred and kept for 30 minutes, then the temperature was lowered to 80°C, 0.01 parts of a polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, and the reaction was continued for 40 minutes, then the temperature was lowered to 50°C, 17.7 parts of B1 was added, and the reaction was continued for 30 minutes, 32.2 parts of D1 was added, 1.3 parts of E1 was added after stirring for 5 minutes, 6.1 parts of triethylamine TEA was added after stirring for 5 minutes, and 201 parts of deionized water was added and dispersed at a high speed for 10 minutes, and then the filtrate was obtained to obtain an epoxy-modified photocurable polyacrylate dispersion 1.

[0108] Example 2

[0109] An epoxy-modified photocurable polyacrylate dispersion 2 was prepared by the following steps:

[0110] S1. In mass parts, 2.2 parts of methacrylic acid MAA, 12.5 parts of methyl methacrylate MMA, 6.3 parts of butyl acrylate BA, 7.5 parts of cyclohexyl methacrylate CHMA, 7.5 parts of styrene St, and 0.5 parts of di-tert-butyl peroxide DTBP were mixed uniformly to form a mixed solution A2, which was ready for use;

[0111] S2. In mass parts, 8.4 parts of hexamethylene diisocyanate HDI was heated to 60°C, and 5.8 parts of 4-hydroxybutyl vinyl ether HBVE was added dropwise at a constant pressure within 25 minutes, and the reaction was continued for 0.8 hours to obtain a prepolymer B2 containing vinyl and isocyanate groups, which was ready for use;

[0112] S3. In a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, 24.2 parts of special epoxy soybean oil GreenSoft H was added, stirred and heated, the temperature was raised to 65°C, 5.2 parts of cyclohexylaminoethanesulfonic acid CHES was added, and the reaction was carried out for 90 minutes to obtain a hydrophilically modified bio-based material C2, which was ready for use;

[0113] S4. In mass parts, 14.9 parts of MF-3286 and 10.4 parts of cyclohexylaminoethanesulfonic acid CHES were uniformly mixed, the reaction temperature was controlled at 45°C, and the reaction was carried out for 2 hours to form a prepolymer D2, which was ready for use;

[0114] S5. In mass parts, 0.4 parts of a blocked cationic thermal initiator CTI-200, 0.6 parts of a cationic photoinitiator HRcure-9388 and 0.3 parts of a free radical photoinitiator Irgacure 2959 were uniformly mixed to form a mixture E2, which was ready for use;

[0115] S6. In mass parts, the hydrophilically modified bio-based material C2 was heated to 140°C and then added dropwise into the mixed solution A2 at a constant pressure within 3.5 hours. After the dropwise addition was completed, the mixture was stirred and kept at temperature for 40 minutes, the temperature was lowered to 70°C, 0.01 parts of a polymerization inhibitor MEHQ was added, 9.0 parts of N-butoxymethyl acrylamide was added, and the reaction was continued for 50 minutes. The temperature was lowered to 45°C, 14.2 parts of B2 was added, and the reaction was continued for 40 minutes. 25.3 parts of D2 was added, 1.3 parts of E2 was added after stirring for 7 minutes, 5.3 parts of N,N-dimethylethanolamine DMEA was added after stirring for 3 minutes, and 181 parts of deionized water was added and dispersed at high speed for 15 minutes. The filtrate was obtained to give an epoxy-modified photocurable polyacrylate dispersion 2.

[0116] Example 3

[0117] An epoxy-modified photocurable polyacrylate dispersion 3 was prepared by the following steps:

[0118] S1. In mass parts, 1.8 parts of acrylic acid AA, 11.3 parts of methyl methacrylate MMA, 7.5 parts of butyl acrylate BA, 6.3 parts of butyl methacrylate BNMA, 8.7 parts of styrene St, and 0.4 parts of di-tert-butyl peroxide DTBP were uniformly mixed to form a mixed solution A3, which was ready for use;

[0119] S2. In mass parts, 13.1 parts of hydrogenated MDI was heated to 70°C, and 8.5 parts of cyclohexyl-1,4-dimethanol monovinyl ether was added dropwise at a constant pressure within 15 minutes. The reaction was continued for 0.8 hours to obtain a prepolymer B3 containing vinyl and isocyanate groups, which was ready for use;

[0120] S3. In mass parts, 18.5 parts of epoxy linseed oil was added to a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, and the mixture was heated to 70°C. 5.2 parts of cyclohexylaminoethanesulfonic acid CHES was added, and the reaction was carried out for 90 minutes to obtain a hydrophilically modified bio-based material C3, which was ready for use; 9-5 TM , stirring and heating, the temperature was raised to 60℃, 5.9 parts of cyclohexylaminobutane sulfonic acid CABS was added, and the reaction was carried out for 90 minutes to obtain a hydrophilic modified bio-based material C3, which was ready for use;

[0121] S4. 13.9 parts of MF-3102 and 11.8 parts of cyclohexylaminobutane sulfonic acid CABS were mixed uniformly in mass fraction, the reaction temperature was controlled at 40℃, and the reaction was carried out for 2 hours to form a prepolymer D3, which was ready for use;

[0122] S5. 0.5 parts of a blocked cationic thermal initiator CTI-300, 0.5 parts of a cationic photoinitiator Omnirad 250 and 0.3 parts of a free radical photoinitiator Irgacure 500 were mixed uniformly in mass fraction to form a mixture E3, which was ready for use;

[0123] S6. The hydrophilic modified bio-based material C3 was heated to 145℃ and then added dropwise into the mixed solution A3 in 4 hours in mass fraction, after the dropwise addition was completed, the mixture was stirred and kept for 35 minutes, the temperature was lowered to 75℃, 0.01 parts of a polymerization inhibitor MEHQ was added, 6.6 parts of hydroxyethyl acrylamide was added, and the reaction was continued for 60 minutes, the temperature was lowered to 55℃, 21.6 parts of B3 was added, and the reaction was continued for 35 minutes, 25.7 parts of D3 was added, 1.3 parts of E3 was added after stirring for 5 minutes, 7.6 parts of N,N-dimethylcyclohexylamine DMCHA was added after stirring for 5 minutes, and 185 parts of deionized water was added and dispersed at high speed for 20 minutes, and then the filtrate was obtained to obtain an epoxy modified photocurable polyacrylate dispersion 3.

[0124] Comparative Example 1

[0125] An epoxy modified photocurable polyacrylate dispersion 4, the difference between the present comparative example and the examples is that the isophorone diisocyanate IPDI and triethylene glycol divinyl ether DVE are added in excess in step S2, which is prepared by the following steps:

[0126] S1. 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobutyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP were mixed uniformly in mass fraction to form a mixed solution A4, which was ready for use;

[0127] S2. 35.0 parts of isophorone diisocyanate IPDI was heated to 50℃, and then 20.8 parts of triethylene glycol divinyl ether DVE was added dropwise at a constant pressure in 15 minutes, and the reaction was continued for 1 hour to obtain a prepolymer B4 containing vinyl and isocyanate groups, which was ready for use;

[0128] S3. In a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, 25.2 parts of special epoxy soybean oil GreenSoft D was added, stirred and heated, the temperature was raised to 73°C, 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS was added, and the reaction was carried out for 75 minutes to obtain a hydrophilic modified bio-based material C4, which was ready for use;

[0129] S4. In mass parts, 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS were mixed uniformly, the reaction temperature was controlled at 40°C, and the reaction was carried out for 1.5 hours to form a prepolymer D4, which was ready for use;

[0130] S5. In mass parts, 0.4 parts of a blocked cationic thermal initiator CTI-100, 0.5 parts of a cationic photoinitiator HRcure-9387 and 0.4 parts of a free radical photoinitiator Darocur 1173 were mixed uniformly to form a mixture E4, which was ready for use;

[0131] S6. In mass parts, the hydrophilic modified bio-based material C4 was heated to 150°C and added dropwise to the mixed solution A4 at a constant pressure within 4 hours. After the dropwise addition was completed, the mixture was stirred and kept at temperature for 30 minutes. The temperature was lowered to 80°C, 0.01 parts of a polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, and the reaction was continued for 40 minutes. The temperature was lowered to 50°C, 55.8 parts of B4 was added, and the reaction was continued for 30 minutes. 32.2 parts of D4 was added, stirred for 5 minutes, 1.3 parts of E4 was added, stirred for 5 minutes, 6.1 parts of triethylamine TEA was added, stirred for 5 minutes, and 258 parts of deionized water was added and dispersed at high speed for 10 minutes. The filtrate was obtained to obtain an epoxy modified photocurable polyacrylate dispersion 4;

[0132] Comparative Example 2

[0133] An epoxy modified photocurable polyacrylate dispersion 5, which is different from Comparative Example 2 and Example 1 in that it does not include a vinyl ether double bond monomer, was prepared by the following steps:

[0134] S1. In mass parts, 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP were mixed uniformly to form a mixed solution A5, which was ready for use;

[0135] S2. In mass parts, 25.2 parts of special epoxy soybean oil GreenSoft D was added to a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, stirred and heated, the temperature was raised to 73°C, 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS was added, and the reaction was carried out for 75 minutes to obtain a hydrophilic modified bio-based material C5, which was ready for use;

[0136] S3. 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS were mixed uniformly in mass fraction, the reaction temperature was controlled at 40°C, and the reaction was carried out for 1.5 hours to form a prepolymer D5, which was reserved;

[0137] S4. 0.4 parts of a blocked cationic thermal initiator CTI-100, 0.5 parts of a cationic photoinitiator HRcure-9387, and 0.4 parts of a free radical photoinitiator Darocur 1173 were mixed uniformly in mass fraction to form a mixture E5, which was reserved;

[0138] S5. The hydrophilic modified bio-based material C5 was heated to 150°C and then added dropwise into the mixed solution A5 at a constant pressure within 4 hours, after the dropwise addition was completed, stirring and heat preservation were carried out for 30 minutes, the temperature was lowered to 80°C, 0.01 parts of a polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, and the reaction was continued for 40 minutes, the temperature was lowered to 50°C, 32.2 parts of D5 was added, 1.3 parts of E5 was added after stirring for 5 minutes, 6.1 parts of triethylamine TEA was added after stirring for 5 minutes, 174 parts of deionized water was added and high-speed dispersed for 10 minutes, and the filtrate was obtained to obtain an epoxy modified photocurable polyacrylate dispersion 5;

[0139] Comparative Example 3

[0140] An epoxy modified photocurable polyacrylate dispersion 6, compared with Comparative Example 3 and Example 1, the proportion of epoxy resin was too high, which was prepared by the following steps:

[0141] S1. 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP were mixed uniformly to form a mixed solution A6, which was reserved;

[0142] S2. 11.1 parts of isophorone diisocyanate IPDI was heated to 50°C, and 6.6 parts of triethylene glycol divinyl ether DVE was added dropwise at a constant pressure within 15 minutes, and the reaction was continued for 1 hour to obtain a prepolymer B6 containing vinyl and isocyanate groups, which was reserved;

[0143] S3. 25.2 parts of special epoxy soybean oil GreenSoft D was added into a four-necked flask equipped with a thermometer, a condenser, and a stirring paddle, and stirred and heated, the temperature was raised to 73°C, 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS was added, and the reaction was carried out for 75 minutes to obtain a hydrophilic modified bio-based material C6, which was reserved;

[0144] S4. Mix 42.2 parts of MF-4101 and 22.1 parts of cyclohexylaminopropanesulfonic acid CAPS in mass fraction, control the reaction temperature at 40°C, and react for 1.5 hours to form a prepolymer D6, which is ready for use;

[0145] S5. Mix 0.4 parts of a blocked cationic thermal initiator CTI-100, 0.5 parts of a cationic photoinitiator HRcure-9387, and 0.4 parts of a free radical photoinitiator Darocur 1173 in mass fraction to form a mixture E6, which is ready for use;

[0146] S6. Add the hydrophilic modified bio-based material C6 dropwise into the mixed solution A6 at a constant pressure within 4 hours when heated to 150°C in mass fraction, stir and keep warm for 30 minutes after the dropwise addition is completed, cool to 80°C, add 0.01 parts of a polymerization inhibitor MEHQ, add 9.7 parts of diacetone acrylamide DAAM, continue to react for 40 minutes, cool to 50°C, add 17.7 parts of B6, continue to react for 30 minutes, add 64.3 parts of D6, add 1.3 parts of E6 after stirring for 5 minutes, add 10.1 parts of triethylamine TEA after stirring for 5 minutes, add 255 parts of deionized water and disperse at a high speed for 10 minutes, and filter the material to obtain an epoxy modified photocurable polyacrylate dispersion 6;

[0147] Comparative Example 4

[0148] An epoxy modified photocurable polyacrylate dispersion 7, in which the photoinitiator and the blocked thermal initiator are not dispersed together with the resin but are only added in the coating preparation stage, is prepared by the following steps:

[0149] S1. Mix 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP in mass fraction to form a mixed solution A7, which is ready for use;

[0150] S2. Add 11.1 parts of isophorone diisocyanate IPDI dropwise into 6.6 parts of triethylene glycol divinyl ether DVE at a constant pressure within 15 minutes when heated to 50°C, and continue to react for 1 hour to obtain a prepolymer B7 containing a vinyl group and an isocyanate group, which is ready for use;

[0151] S3. Add 25.2 parts of a special epoxy soybean oil GreenSoft D into a four-necked flask equipped with a thermometer, a condenser, and a stirring paddle, stir and heat, and raise the temperature to 73°C, then add 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS, and react for 75 minutes to obtain a hydrophilic modified bio-based material C7, which is ready for use;

[0152] S4. 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS were uniformly mixed in mass fraction, the reaction temperature was controlled at 40°C, and the reaction was carried out for 1.5 hours to form a prepolymer D7, which was reserved;

[0153] S5. When the hydrophilic modified bio-based material C7 was heated to 150°C, 4 hours were taken to drop it into the mixed solution A7 at constant pressure, after the dropping was completed, stirring and heat preservation were carried out for 30 minutes, the temperature was lowered to 80°C, 0.01 parts of the polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, the reaction was continued for 40 minutes, the temperature was lowered to 50°C, 17.7 parts of B7 was added, the reaction was continued for 30 minutes, 32.2 parts of D7 was added, 6.1 parts of triethylamine TEA was added after stirring for 5 minutes, 199 parts of deionized water was added after stirring for 5 minutes, high-speed dispersion was carried out for 10 minutes, and the material was filtered out to obtain an epoxy modified photocuring polyacrylate dispersion 7;

[0154] Comparative Example 5

[0155] An epoxy modified photocuring polyacrylate dispersion 8, which was not added with a blocked cationic thermal initiator compared with Comparative Example 5 and Example 1, was prepared by the following steps:

[0156] S1. 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP were uniformly mixed to form a mixed solution A8, which was reserved;

[0157] S2. 11.1 parts of isophorone diisocyanate IPDI was heated to 50°C, 6.6 parts of triethylene glycol divinyl ether DVE was dropped into it at constant pressure within 15 minutes, and the reaction was continued for 1 hour to obtain a prepolymer B8 containing vinyl and isocyanate groups, which was reserved;

[0158] S3. 25.2 parts of special epoxy soybean oil GreenSoft D was added to a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, stirring and heating were carried out, the temperature was raised to 73°C, 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS was added, and the reaction was carried out for 75 minutes to obtain a hydrophilic modified bio-based material C8, which was reserved;

[0159] S4. 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS were uniformly mixed in mass fraction, the reaction temperature was controlled at 40°C, and the reaction was carried out for 1.5 hours to form a prepolymer D8, which was reserved;

[0160] S5. Mix 0.5 parts of cationic photoinitiator HRcure-9387 and 0.4 parts of free radical photoinitiator Darocur 1173 in mass fraction to form a mixture E8, ready for use;

[0161] S6. When the hydrophilic modified bio-based material C8 is heated to 150℃, add it into the mixed solution A8 at a constant pressure within 4 hours in mass fraction, stir and keep warm for 30 minutes after the drop is completed, cool to 80℃, add 0.01 parts of polymerization inhibitor MEHQ, add 9.7 parts of diacetone acrylamide DAAM, continue to react for 40 minutes, cool to 50℃, add 17.7 parts of B8, continue to react for 30 minutes, add 32.2 parts of D8, stir for 5 minutes, then add 0.9 parts of E8, stir for 5 minutes, then add 6.1 parts of triethylamine TEA, stir for 5 minutes, then add 200 parts of deionized water and disperse at high speed for 10 minutes, filter the material to obtain an epoxy modified photocurable polyacrylate dispersion 8.

[0162] Comparative Example 6

[0163] This comparative example prepared an epoxy modified photocurable polyacrylate dispersion. The difference between this comparative example and Example 1 is that the hydroxy acrylate is replaced by hydroxy vinyl ether, and the rest of the conditions are the same as Example 1.

[0164] S1. Mix 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP in mass fraction to form a mixed solution A9, ready for use;

[0165] S2. When 11.1 parts of isophorone diisocyanate IPDI is heated to 50℃, add 6.5 parts of hydroxyethyl methacrylate HEMA at a constant pressure within 15 minutes, continue to react for 1 hour to obtain a prepolymer B9 containing vinyl and isocyanate groups, ready for use;

[0166] S3. In a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, add 25.2 parts of special epoxy soybean oil GreenSoft D, stir and heat, and raise the temperature to 73℃, then add 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS, and react for 75 minutes to obtain a hydrophilic modified bio-based material C9, ready for use;

[0167] S4. Mix 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS in mass fraction, control the reaction temperature at 40℃, and react for 1.5 hours to form a prepolymer D9, ready for use;

[0168] S5. 0.4 parts of blocked cationic thermal initiator CTI-100, 0.5 parts of cationic photoinitiator HRcure-9387 and 0.4 parts of free radical photoinitiator Darocur 1173 were mixed uniformly to form a mixture E9, ready for use;

[0169] S6. The hydrophilically modified bio-based material C9 was heated to 150℃ and added dropwise into the mixture A9 at a constant pressure within 4 hours, after the dropwise addition was completed, the mixture was stirred and kept for 30 minutes, then cooled to 80℃, 0.01 parts of polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, and the reaction was continued for 40 minutes, then cooled to 50℃, 17.7 parts of B1 was added, and the reaction was continued for 30 minutes, 32.2 parts of D9 was added, stirred for 5 minutes, then 1.3 parts of E9 was added, stirred for 5 minutes, then 6.1 parts of triethylamine TEA was added, stirred for 5 minutes, then 201 parts of deionized water was added and dispersed at high speed for 10 minutes, and the product was filtered to obtain an epoxy modified photocurable polyacrylate dispersion 9.

[0170] Comparative Example 7

[0171] This comparative example provides an epoxy modified photocurable polyacrylate dispersion, the difference between the comparative example and Example 1 is that the blocked cationic thermal initiator Vicbase TC3635 with an initiation temperature of 120℃ is used to replace CTI-100, and the other conditions are the same.

[0172] S1. 1.8 parts of acrylic acid AA, 13.8 parts of methyl methacrylate MMA, 5 parts of butyl acrylate BA, 4.3 parts of isobornyl acrylate IBOA, 10.8 parts of styrene St, and 0.6 parts of di-tert-amyl peroxide DTAP were mixed uniformly to form a mixture A10, ready for use;

[0173] S2. 11.1 parts of isophorone diisocyanate IPDI was heated to 50℃, and 6.6 parts of triethylene glycol divinyl ether DVE was added dropwise at a constant pressure within 15 minutes, and the reaction was continued for 1 hour to obtain a prepolymer B10 containing vinyl and isocyanate groups, ready for use;

[0174] S3. 25.2 parts of special epoxy soybean oil GreenSoft D was added to a four-necked flask equipped with a thermometer, a condenser and a stirring paddle, stirred and heated, and the temperature was raised to 73℃, 5.5 parts of cyclohexylaminopropanesulfonic acid CAPS was added, and the reaction was continued for 75 minutes to obtain a hydrophilically modified bio-based material C10, ready for use;

[0175] S4. 21.1 parts of MF-4101 and 11.1 parts of cyclohexylaminopropanesulfonic acid CAPS were mixed uniformly, and the reaction temperature was controlled at 40℃, and the reaction was continued for 1.5 hours to form a prepolymer D10, ready for use;

[0176] S5. 0.4 parts of blocked cationic thermal initiator Vicbase TC3635, 0.5 parts of cationic photoinitiator HRcure-9387 and 0.4 parts of free radical photoinitiator Darocur 1173 were mixed uniformly to form a mixture E10, ready for use;

[0177] S6. The hydrophilic modified bio-based material C10 was heated to 150℃ and added dropwise into the mixed solution A10 at a constant pressure within 4 hours, after the dropwise addition was completed, the solution was stirred and kept for 30 minutes, then cooled to 80℃, 0.01 parts of polymerization inhibitor MEHQ was added, 9.7 parts of diacetone acrylamide DAAM was added, and the reaction was continued for 40 minutes, then cooled to 50℃, 17.7 parts of B10 was added, and the reaction was continued for 30 minutes, 32.2 parts of D10 was added, after stirring for 5 minutes, 1.3 parts of E10 was added, after stirring for 5 minutes, 6.1 parts of triethylamine TEA was added, after stirring for 5 minutes, 201 parts of deionized water was added and dispersed at high speed for 10 minutes, then the product was filtered to obtain an epoxy modified photocurable polyacrylate dispersion 10.

[0178] Test Example 1

[0179] A cationic photocurable bio-based coating was prepared, and the epoxy modified photocurable polyacrylate dispersion was prepared according to the embodiments and comparative examples, and the specific steps were as follows:

[0180] The cationic photocurable bio-based coating was composed of the following components by weight:

[0181]

[0182]

[0183] The preparation method of the cationic photocurable bio-based coating was as follows: the cationic photocurable bio-based polyurethane dispersion was added to a stirred tank, the stirring speed was 700 rpm, water, propylene glycol butyl ether and propylene glycol methyl ether were premixed and added to the stirred tank, DISPERS 755W, Ti-Pure R-902+, Irgacure 2959, Lucirin TPO-L, Omnirad 250, TEGO-825, RM-8W and TEGO-245 were added in sequence, and dispersed for 20 minutes, then the product was filtered to obtain the cationic photocurable bio-based coating.

[0184] After the cationic photocurable bio-based coating was prepared into a paint film and dried at 50℃ for 2 hours, the mercury lamp of the photocuring machine was turned on, and the UVV energy was adjusted to 600 mJ / cm 2 cured, and baked at 100℃ for 2h, and the performance was shown in Table 1.

[0185] The test standards were as follows:

[0186] Coating film appearance: visual inspection;

[0187] Pencil hardness: GB / T 6739-2006;

[0188] Coating film gloss (60°, %): GB / T 9754-2007;

[0189] Water resistance (25°C, 24h): GB / T 4893.1-2020;

[0190] Dry heat resistance (70±2°C, 15h): GB / T 4893.3-2020;

[0191] Ethanol resistance (50%, 1h): GB / T 4893.1-2020;

[0192] Adhesion: GB / T 9286-2021;

[0193] Table 1 Performance parameters of epoxy-modified photocuring polyacrylate dispersions and water-based photocuring bio-based coatings

[0194]

[0195]

[0196]

[0197] As can be seen from the above table, compared with Example 1, the content of secondary amine groups generated by the reaction of IPDI and DVE and the reaction of B3 with the hydroxyl groups of the prepolymer is too high in Comparative Example 1, which reacts with the epoxy groups of MF-4101, resulting in poor dispersion stability; compared with Example 1, the copolymerization of cationic photoinitiated polymerization and free radical initiated polymerization is reduced, and the double bond concentration is reduced, and a large amount of hydroxyl groups remain in Comparative Example 2, so the paint film resistance is poor. Compared with Example 1, the content of epoxy resin is too high in Comparative Example 3, and the epoxy groups will react with the secondary amine groups, resulting in poor dispersion stability. Compared with Example 1, the photoinitiator and the blocked thermal initiator are not dispersed together with the resin, but are only added during the preparation of the paint, so the paint film resistance is poor, the hardness is low, and the adhesion is poor. Compared with Example 1, no blocked cationic thermal initiator is added in Comparative Example 5, so the paint film resistance is poor, the hardness is low, and the adhesion is poor. Compared with Example 1, the hydroxyl vinyl ether monomer is replaced by a hydroxyl acrylate monomer in Comparative Example 6, and the double bond of the hydroxyl acrylate mainly participates in free radical curing, and the cationic curing is weak, so the cationic curing is only performed by the epoxy groups, the copolymerization of cationic curing and free radical curing is reduced, and thus the paint film flexibility, transparency and adhesion and other properties are poor. Compared with Example 1, the initiation temperature of the blocked cationic thermal initiator is 120℃ in Comparative Example 7, and since many wooden substrates are prone to deformation after being baked at a temperature exceeding 100℃, the set baking temperature of 100℃ is lower than the initiation temperature of 120℃, so the initiator has no initiation effect, and thus the paint film performance is similar to that of Example 5 without the blocked cationic thermal initiator. As can be seen from Examples 1, 2 and 3, the preparation method of the epoxy-modified photocurable polyacrylate dispersion disclosed in the application is used to prepare a paint film of the cationic photocurable bio-based coating, which has the advantages of good flexibility, good water and chemical resistance, excellent adhesion to various substrates, and can be applied to high-grade woodenware coatings, automobile coatings, metal anticorrosion coatings and other industrial protective coatings.

[0198] The above embodiments of the application are described in detail, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application. In addition, the embodiments of the application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for preparing an epoxy-modified light-curable polyacrylate dispersion, characterized in that: The preparation method comprises the following steps: S1. In parts by mass, 1.5 to 2.5 parts of acrylic acid monomer, 20 to 30 parts of acrylate monomer, 5 to 11 parts of vinyl monomer, and 0.4 to 0.6 parts of initiator are mixed to form a mixed solution A; S2. In parts by mass, 8 to 15 parts of diisocyanate are heated to 50 to 70 ° C and then added dropwise to 5 to 9 parts of hydroxy vinyl ether, and the reaction is continued for 0.8 to 1.5 hours to obtain a prepolymer containing vinyl and isocyanate groups B; S3. In parts by mass, 18 to 26 parts of the bio-based material are heated to 55 to 75°C, 5 to 6 parts of a hydrophilic modifier are added, and the reaction obtains a hydrophilically modified bio-based material C; S4. In parts by mass, 10 to 25 parts of an epoxy resin and 10 to 15 parts of a hydrophilic modifier are mixed, the reaction temperature is controlled to be 40 to 45 ° C, and the reaction forms a prepolymer D; S5. In parts by mass, 0.3 to 0.5 parts of a blocked cationic thermal initiator, 0.3 to 0.6 parts of a cationic photoinitiator, and 0.3 to 0.5 parts of a free radical photoinitiator are mixed to form a mixture E; S6. When the hydrophilic modified bio-based material C is heated to 130-150°C, the mixed solution A is added dropwise within 3-4 hours. After the addition is complete, the mixture is stirred and kept warm for 20-40 minutes. The mixture is cooled to 60-80°C, 0.01 parts of polymerization inhibitor MEHQ is added, 6-10 parts of acrylamide monomer are added, and the reaction is continued for 30-60 minutes. The mixture is cooled to 45-55°C, and a prepolymer B containing vinyl and isocyanate groups is added. The reaction is continued for 30-40 minutes. The prepolymer D is added, and the mixture E is added after stirring for 5-10 minutes. After stirring for 3-5 minutes, 5-8 parts of a neutralizing agent are added. After stirring for 3-5 minutes, 180-210 parts of deionized water are added and dispersed for 10-20 minutes. The material is filtered to obtain an epoxy-modified light-curable polyacrylate dispersion. Wherein, the bio-based material is a plant oil containing three or more epoxy groups; The hydrophilic modifier is a monomer containing a secondary amino group and a sulfonic acid group; The epoxy resin is an epoxy resin containing three or more epoxy groups; The neutralizing agent is a tertiary amine; The hydrophilic modifiers in step S3 and step S4 are the same or different; The initiation temperature of the blocked cationic thermal initiator is 70-100°C.

2. The preparation method according to claim 1, characterized in that The initiator includes at least one of di-tert-amyl peroxide and di-tert-butyl peroxide.

3. The preparation method according to claim 1, characterized in that The hydroxy vinyl ether includes at least one of 4-hydroxybutyl vinyl ether, triethylene glycol divinyl ether and cyclohexyl-1,4-dimethanol monovinyl ether.

4. The preparation method according to claim 1, characterized in that The epoxy resin includes at least one of tetraglycidyldiaminodimethylenebenzene, diglycidyl 4,5-epoxytetrahydrophthalate, and triglycidyl-p-aminophenol.

5. The preparation method according to claim 1, characterized in that The blocked cationic thermal initiator includes a blocked phosphate cationic thermal initiator.

6. An epoxy-modified light-curable polyacrylate dispersion, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 5.

7. A water-based bio-based light-curing coating, characterized in that: The preparation raw materials include the epoxy-modified light-curing polyacrylate dispersion according to claim 6.

8. The water-based bio-based light-curing coating according to claim 7, characterized in that: The preparation comprises the following raw materials in parts by weight: 50-65 parts of epoxy modified light-curing polyacrylate dispersion; 1-3 parts of free radical photoinitiator; 1-3 parts of cationic photoinitiator; 27-36 parts water; 5-15 parts of titanium dioxide; 2.6~5.2 parts of additives.

9. Use of the waterborne bio-based photocurable coating according to claim 7 or 8 in automobile manufacturing.

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