CN113717364A

CN113717364A - 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group

Info

Publication number: CN113717364A
Application number: CN202110899072.4A
Authority: CN
Inventors: 许钧强; 康伦国; 姚东生
Original assignee: Shaoguan Union Chemical Co Ltd; Union Foshan Chemical Co Ltd
Current assignee: Shaoguan Union Chemical Co Ltd; Union Foshan Chemical Co Ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2021-11-30

Abstract

The invention relates to 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group and a preparation method thereof, wherein neopentyl glycol is taken as a core, a dendritic structure is taken as a shell, and the dendritic LED resin contains a plurality of functional active groups, thioxanthone photoinitiating groups and branched chain cluster alkane groups; the method is characterized in that: 1) energy migration and intermolecular reaction in a polymer chain are easier, and the self-initiation efficiency is high; 2) the space between the photoactive group and the main chain is shortened, and the photosensitivity is improved; 3) excellent system compatibility; 4) high solid low viscosity, pigment load bearing and storage stability; 5) the defects caused by a micromolecular photoinitiator are overcome; the dendritic LED resin prepared by the invention has excellent flexibility, adhesive force, chemical resistance, heat resistance, aging resistance, oil resistance, wear resistance, pollution resistance, impact strength and odorless coating, and is used for LED color floor coatings, LED wood coatings, LED alloy coatings, LED circuit board ink and LED plastic coatings.

Description

3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group

Technical Field

The invention relates to a modified self-initiated UV resin, in particular to a 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating groups and a preparation method thereof, belonging to the technical field of synthetic resins.

Background

In recent years, environmental friendly coatings, including high solids and solventless coatings, waterborne coatings, powder coatings and photocurable coatings, have rapidly developed. The photocuring technology has the advantages of rapid curing, high production efficiency, room temperature operation, low energy consumption, low VOC, environmental protection, high quality, economy, suitability for various base materials and the like, and is widely applied to various industries such as printing, packaging, advertising, building materials, decoration, electronics, communication, computers, shops, automobiles, aviation, aerospace, instruments and meters, sports, sanitation and the like.

The dendritic polymer is an important highly branched polymer and has a unique structure, for example, nano micropores in the interior of a unique molecule can chelate ions, adsorb small molecules or serve as catalytic active points of small molecule reaction; the low-melting viscosity is difficult to crystallize and is free from winding, so that the solubility is greatly improved; compared with linear molecules with the same molecular mass, the modified polymer has the characteristics of low viscosity, a plurality of terminal groups capable of being modified and the like, and the unique structure and characteristics have close relation in the application field.

The dendritic polymer has low melting viscosity and a plurality of modifiable end groups, so that the dendritic polymer has wide application prospect in the field of coatings. For example, the (methyl) acrylic acid hyperbranched polymer which can be rapidly cured under the irradiation of ultraviolet light has low viscosity of a coating system consisting of the (methyl) acrylic acid hyperbranched polymer, a polyfunctional monomer for dilution can be added in no need or a small amount, and the cured film has excellent mechanical properties and is an environment-friendly material. Dendrimers have become a focus of research in recent years.

At present, a UV system mainly comprises oligomer UV resin, an active diluent and a photoinitiator, the used initiator is mostly organic micromolecules, the yellowing resistance and the migration resistance are poor, the initiator has certain amount and is mostly organic micromolecules, the yellowing resistance and the migration resistance are poor, the initiator has certain toxicity, harmful photodecomposition products (such as benzaldehyde) can be generated, the adverse effects can be generated on the environment and the human health, the application of an ultraviolet curing technology in the fields of printing ink, food packaging and the like is restricted, and therefore the ultraviolet curing oligomer with the self-initiation function is more and more valued. Therefore, in the formula of the UV coating, the ink and the adhesive using the oligomer with the self-initiation function, the photoinitiator can not be added, so that the problems of odor, yellowing, environmental protection, difficult mixing, precipitation, migration, high price and the like caused by adding the photoinitiator are avoided.

The oligomer products with photoinitiation function on the market are Drewrad series products developed by the American Islands company, the first type is that multifunctional acrylate and beta ketoester (such as ethyl acetoacetate, allyl acetoacetate and 2-ethyl acetoacetate) are subjected to Michael addition reaction, carbon on an active methylene in the beta ketoester forms a new covalent bond with terminal carbon of a carbon-carbon double bond of the acrylate, and carbonyl in the beta ketoester is connected with a completely substituted carbon atom, so that the bond is unstable to ultraviolet light, and after the ultraviolet light is absorbed, the bond is easily broken to generate acetyl free radical and another macromolecular free radical, and the oligomer products have the self-initiation function. The second type is to use a small molecule photoinitiator (benzoin, 1173, 184, 2959) containing hydroxyl to react with an oligomer with isocyanate groups, and the photoinitiator is grafted into the oligomer to form an oligomer with produced UV coating and photoinitiating groups.

Oligomer products with photoinitiating functionality developed by Bomar corporation, USA, incorporate macromolecular photoinitiators into oligomer molecules. In 2006 the U.S. Food and Drug Administration (FDA) approved UV coatings and inks produced with macrophotoinitiators for use in food and drug packaging printing, expanding the field of application of UV inks and coatings.

Chinese patent CN107602851A discloses an aqueous self-initiated visible light unsaturated polyester amide urea resin and a preparation method thereof, which comprises the steps of mixing dibasic acid, dihydric alcohol and urea, heating and reacting at 160-210 ℃ for 200-600 min under the protection of nitrogen, distilling to remove water, adding pentaerythritol triallyl ether, heating and reacting at 160-210 ℃ for 60-120 min, adding cinnamic acid, heating and reacting at 160-210 ℃ for 60-120 min, and cooling to obtain the product; the unsaturated polyester amide urea resin disclosed by the invention not only has self-initiation property, but also has water solubility and visible light curing, and is applied to preparation of a water-based self-initiation visible light curing coating.

Zhangpengfei, Yangbeiping, etc. synthesized a hyperbranched UV self-initiating polymer, prepared by n (diethanolamine): carrying out Michael addition reaction on N (methyl methacrylate) ═ 1:1.05 to prepare N, N-dihydroxyethyl-3-aminomethyl methyl propionate (MMB); synthesizing a2 nd-generation hydroxyl-terminated hyperbranched polymer (PM-2) by a quasi-one-step method by taking pentaerythritol as a core and MMB as a branched monomer; toluene-2, 4-diisooxolate respectively reacts with methacrylic acid-beta-hydroxyethyl and D1173 to prepare a functional monomer TDI-HEMA containing double bonds and a functional monomer TDI-1173 containing photoinitiating groups, PM-2 is subjected to end group modification reaction through the two monomers to obtain a hyperbranched UV self-initiated polymer (PM-UV), and finally various PM-UV are prepared by adjusting the quantity ratio of the double bonds to the photoinitiating groups in the PM-UV.

The Thioxanthone (TX) photoinitiator is a hydrogen abstraction type free radical photoinitiator, has strong absorption between 370 and 385nm, has a wavelength close to that emitted by UV-LED light of 355 to 410nm, has high photoinitiation efficiency, and has long ultraviolet absorption without being influenced by color, so the thioxanthone initiator is suitable for a pigment-containing system. Currently commercially available are 2-Chlorothianthrone (CTX), 2-Isopropylthioxanthone (ITX), 2-Hydroxythioxanthone (HTX), 2, 4-dimethylthioxanthone (RTX) and 2, 4-Diethylthioxanthone (DETX), but the TX photoinitiators are poorly soluble in both oligomers and reactive diluents.

Disclosure of Invention

The invention provides 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group and a preparation method thereof.

The dendritic polymer is a macromolecule with a three-dimensional structure, has determined molecular weight and size, the molecular weight distribution presents monodispersity, the molecular structure is symmetrical, and the periphery of the molecule has a plurality of functional groups, so the dendritic polymer has special physical and chemical properties. Compared with the traditional linear coating resin, the dendritic polymer has the characteristics of spherical three-dimensional structure, a large number of end groups, no chain entanglement in molecules and among molecules and the like, can provide excellent performances of low viscosity, high reactivity, high adhesive force with a base material and the like for the coating, can be quickly cured to form a film under the irradiation of ultraviolet light, and can obtain good intermiscibility when being mixed with other polyfunctional group monomers.

The invention adopts neopentyl glycol as a core and a monomer containing bis-hydroxymethyl carboxylic acid as a branched structural unit, and synthesizes the 3 rd generation dendritic polymer containing 16 terminal hydroxyl groups, and the terminal hydroxyl groups of the dendritic polymer have small volume, relatively easy peripheral molecular motion and strong hydrogen bond action, so the glass transition temperature (Tg) of the dendritic polymer is higher, thereby improving the crosslinking density, the heat resistance, the wear resistance and the impact strength.

The invention introduces thioxanthone macromolecule photoinitiating group into the molecular chain of the dendritic polymer, and has the following characteristics: 1) energy migration and intermolecular reaction in a polymer chain become easier, and the initiator has high initiating activity under the illumination of UV-LED lamp light; 2) the distance between the photoactive group and the main chain is changed, so that the photosensitivity is improved; 3) the solubility and the compatibility with a system are improved; 4) the migration of the photoinitiated groups is limited, and the yellowing and the aging of the coating are prevented; 5) the fragments after photocleavage are still connected on the polymer chain, so that the smell and toxicity of the system can be reduced.

The thioxanthone photoinitiator group is linked through the polyurethane, and meanwhile, the polyurethane can improve the flexibility, adhesive force, chemical resistance, ageing resistance, oil resistance, wear resistance and tensile strength of the resin.

The tertiary carbonic acid glycidyl ester contains a branched chain-shaped alkane structure, and the extended branched chain of the tertiary carbonic acid glycidyl ester has strong steric hindrance effect on carbonyl so as to provide hydrolytic stability; excellent acid resistance, alkali resistance, polar solvent resistance and outdoor aging resistance; improve pigment wetting and gloss; the viscosity of the high-solid LED resin is effectively reduced; excellent compatibility and solubility in aromatic solvents.

According to the invention, the hyperbranched polyester is modified by the tertiary carboxylic acid glycidyl ester, and the bulk alkane structure is suspended and distributed on the branch chain, so that the hydrophobicity, the pigment wettability, the aging resistance, the solvent compatibility and the high solid low viscosity of the resin can be effectively provided.

The 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group has a Boltom type dendritic hyperbranched three-dimensional structure, contains 1-4 functional active groups, 1-4 thioxanthone photoinitiating groups and 1-4 branched chain group alkane groups, and has a molecular structural formula shown as the following formula:

wherein R in the formula is

R₁Is H or CH₃；(R₂+R₃) Is an alkyl group having 6 to 8 carbon atoms.

The preparation mechanism of the 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group is shown in the following reaction formula (taking DMPA as an example):

the invention provides a preparation method of 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating groups, which comprises the following preparation steps in parts by mass:

a) and preparing 3 rd generation dendritic polymer HPB-3 by a quasi-one-step method: adding neopentyl glycol and a monomer containing the bis-hydroxymethyl carboxylic acid into a four-neck flask provided with a stirrer, a thermometer, an addition funnel and a reflux water separator according to the molar ratio of 1:2, then adding dimethylbenzene and a catalyst p-toluenesulfonic acid, heating to 105-150 ℃ under the protection of nitrogen, carrying out reflux reaction for 1-2 h, when the detected acid value is lower than 25mgKOH/g, adding a monomer containing bis-hydroxymethyl carboxylic acid, a catalyst p-toluenesulfonic acid and a proper amount of xylene according to the amount of 1 time and 2 times respectively, reflux reaction is carried out for 1-2 h at 105-150 ℃, when the detected acid value is lower than 25mgKOH/g, monomer containing bis-hydroxymethyl carboxylic acid, catalyst p-toluenesulfonic acid and proper amount of xylene are respectively added according to the amount of 1 time and 4 times of the detected acid value, reflux reaction is carried out for 2h at 105-150 ℃, heating to 150-170 ℃ for continuous reaction, and stopping the reaction until the detected acid value is lower than 20 mgKOH/g; evaporating xylene under reduced pressure, cooling, adding acetone, dissolving completely, adding toluene, stirring, standing to precipitate, vacuum filtering, and vacuum drying at 50 deg.C to obtain purified 3 rd generation dendritic polymer HPB-3;

b) preparing an isocyanate-acrylic acid functional monomer DI-HEA: adding diisocyanate and dibutyltin dilaurate into a four-neck flask provided with a reflux condenser tube, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropwise adding a mixture consisting of a hydroxyl-containing acrylic monomer, hydroquinone and acetone at 30-45 ℃, heating to 45-50 ℃ after dropwise adding, continuing to react for 2-4 h, sampling and detecting the NCO value of the system every 30min, stopping the reaction when the detected NCO value is half of the initial value, and cooling to 40 ℃ to obtain an isocyanate-acrylic acid functional monomer DI-HEA;

c) preparation of 2- (2-hydroxy-) ethoxythioxanthone HETX: adding 98% concentrated sulfuric acid into a reaction bottle provided with a stirring device, a thermometer and a feeding device, cooling to-5-0 ℃ by using an ice salt bath, adding 2, 2' -dithiodibenzoic acid, adding ethylene glycol phenyl ether in batches under stirring, controlling to react for 5-6 h at 0-5 ℃, adding frozen deionized water with the volume of 5-6 times of the concentrated sulfuric acid, stirring for 20min, standing, performing suction filtration, adding deionized water into a filter cake, boiling and refluxing for 2h, cooling, standing, performing suction filtration, washing with water, drying to obtain a crude product, recrystallizing the crude product by using a 1, 4-dioxane-water mixed solvent, stirring, standing, performing suction filtration, and drying to obtain HETX;

d) preparing a thioxanthone photoinitiating group functional monomer DI-HETX: adding diisocyanate and dibutyltin dilaurate into a four-neck flask provided with a reflux condenser tube, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropwise adding an acetone solution of HETX at 40-45 ℃, heating to 50-60 ℃ after dropwise adding, continuously reacting for 2-4 h, sampling and detecting an NCO value of a system every 30min, and stopping reaction when the detected NCO value is half of an initial value to obtain a thioxanthone photoinitiation group functional monomer DI-HETX;

e) and preparing a dendritic prepolymer HPB-HEA containing active functional groups: adding acetone into HPB-3 in the step a), heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding the mixed solution of DI-HEA and hydroquinone in the step b), adding dibutyltin dilaurate after dropwise adding, continuously reacting for 2-4 h at 60-70 ℃, then sampling every 30min to detect the NCO value of the system, and stopping the reaction when the NCO reaction is complete to obtain HPB-HEA dendritic prepolymer;

f) and preparing a dendritic prepolymer HPB-HEA-HETX containing active functional groups and photoinitiating groups: stirring the prepolymer in the step e), heating to 70-90 ℃, slowly dropwise adding a mixed solution of DI-HETX and hydroquinone in the step d) while stirring, then adding dibutyltin dilaurate, carrying out heat preservation reaction for 2-4 h, then sampling and detecting an NCO value of a system every 30min, stopping the reaction when the NCO reaction is complete, and carrying out reduced pressure distillation to remove acetone to obtain a dendritic prepolymer HPB-HEA-HETX;

g) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring the prepolymer in the step f), heating to 85-95 ℃, adding glycidyl versatate, then adding hydroquinone, performing heat preservation reaction for 2-4 h, sampling every 30min, detecting the epoxy value of the system, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group.

Wherein the monomer containing the bis-hydroxymethyl carboxylic acid is one of 2, 2-dimethylolpropionic acid and 2, 2-dimethylolbutyric acid.

The diisocyanate is at least one of toluene diisocyanate TDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI and diphenylmethane diisocyanate MDI; the hydroxyl-containing acrylic monomer is at least one of acrylic acid-beta-hydroxyethyl ester, methacrylic acid-alpha-hydroxyethyl ester and methacrylic acid-beta-hydroxyethyl ester.

The glycidyl versatate is at least one of glycidyl neononanoate, glycidyl neodecanoate or glycidyl neoundecanoate.

In the step a), the 1 st input amount is 2:1 of the molar ratio of the monomer containing the bis-hydroxymethyl carboxylic acid to the neopentyl glycol; feeding neopentyl glycol containing 4 times of mole ratio of bis (hydroxymethyl) carboxylic acid monomer at the 2 nd time; feeding neopentyl glycol containing 8 times of the molar ratio of the bis (hydroxymethyl) carboxylic acid monomer at the 3 rd time; the addition amount of the catalyst p-toluenesulfonic acid is 0.4-0.8% of the amount of the monomer containing the bis-hydroxymethyl carboxylic acid.

In the step b), the molar ratio of the diisocyanate to the hydroxyl-containing acrylic monomer is 1: 1; the addition amount of the dibutyltin dilaurate is 0.05-0.1% of the amount of diisocyanate; the addition amount of the hydroquinone is 0.1-0.2% of the amount of the hydroxyl-containing acrylic monomer.

In the step c), the molar ratio of the 2, 2' -dithiodibenzoic acid to the ethylene glycol phenyl ether is 1: 3; the mass ratio of the concentrated sulfuric acid to the 2, 2' -dithiodibenzoic acid is 5: 1; the volume ratio of the 1, 4-dioxane to water is 4: 1.

In step d), the molar ratio of the diisocyanate to the HETX is 1: 1; the addition amount of the dibutyltin dilaurate is 0.04-0.1% of the amount of diisocyanate.

In the step e), the molar ratio of the DI-HEA to the HPB-3 is 1-4: 1; the addition amount of the hydroquinone is 0.05-0.2% of the amount of the DI-HEA; the addition amount of the dibutyltin dilaurate is 0.02-0.08% of the amount of the DI-HEA.

In the step f), the molar ratio of the DI-HETX to the HPB-3 is 1-4: 1; the addition amount of the hydroquinone is 0.05-0.2% of the amount of the DI-HETX; the addition amount of the dibutyltin dilaurate is 0.02-0.08% of the amount of the DI-HETX.

In the step g), the molar ratio of the tertiary carbonic acid glycidyl ester to the HPB-3 is 1-4: 1; the addition amount of the hydroquinone is 0.05-0.2% of the amount of the tertiary carbonic acid glycidyl ester.

The 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group contains 1-4 functional active groups, 1-4 thioxanthone photoinitiating groups and 1-4 clustered branched alkane groups; the material has a 3 rd generation dendritic hyperbranched three-dimensional structure, 1) the energy migration and intermolecular reaction in a polymer chain are easier, and the material has high self-initiation efficiency under the illumination of UV-LED light; 2) the space between the photoactive group and the main chain is shortened, and the photosensitivity is improved; 3) excellent system compatibility; 4) high solid low viscosity, pigment load bearing and storage stability; 5) the defects caused by a micromolecular photoinitiator are overcome; the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group prepared by the invention has excellent flexibility, adhesive force, chemical resistance, heat resistance, aging resistance, oil resistance, wear resistance, pollution resistance, impact strength and odorless coating, and is widely used for LED color floor coatings, LED wood coatings, LED alloy coatings, LED circuit board ink and LED plastic coatings.

Detailed Description

The preparation of the thioxanthone photoinitiating group modified generation 3 dendritic LED resin of the present invention is further described in conjunction with the following examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention.

Example 1:

the generation 3 dendrimer HPB-3p was prepared as follows: adding 15.6 parts of neopentyl glycol, 40.6 parts of 2, 2-dimethylolpropionic acid, 12.5 parts of xylene and 0.2 part of catalyst p-toluenesulfonic acid into a four-neck flask provided with a stirrer, a thermometer, a feeding funnel and a reflux water separator, heating to 140-150 ℃ under the protection of nitrogen for reflux reaction for 1-2 h, respectively adding 80.4 parts of 2, 2-dimethylolpropionic acid, 0.4 part of p-toluenesulfonic acid and 16.0 parts of xylene when the detected acid value is lower than 25mgKOH/g, reflux reaction for 1-2 h at 140-150 ℃, respectively adding 160.8 parts of 2, 2-dimethylolpropionic acid, 0.8 part of p-toluenesulfonic acid and 32.0 parts of xylene when the detected acid value is lower than 25mgKOH/g, heating to 170 ℃ for reflux reaction for 2h at 140-150 ℃, and continuing the reaction until the detected acid value is lower than 20 mgKOH/g; and (3) evaporating xylene under reduced pressure, cooling, adding 60.0 parts of acetone, completely dissolving, adding 100.0 parts of toluene, stirring, standing to separate out a precipitate, performing suction filtration, and performing vacuum drying at 50 ℃ to obtain the purified 3 rd generation dendritic polymer HPB-3 p.

Example 2:

preparation of generation 3 dendrimer HPB-3 b: adding 15.6 parts of neopentyl glycol, 44.4 parts of 2, 2-dimethylolbutyric acid (DMBA), 13.0 parts of xylene and 0.25 part of catalyst p-toluenesulfonic acid into a four-neck flask provided with a stirrer, a thermometer, a feeding funnel and a reflux water separator, heating to 105-120 ℃ under the protection of nitrogen for reflux reaction for 1-2 h, respectively adding 88.8 parts of 2, 2-dimethylolbutyric acid, 0.5 part of p-toluenesulfonic acid and 20.0 parts of xylene when the detected acid value is lower than 25mgKOH/g, reflux reaction for 1-2 h at 105-120 ℃, respectively adding 177.6 parts of 2, 2-dimethylolbutyric acid, 0.75 parts of p-toluenesulfonic acid and 35.0 parts of xylene when the detected acid value is lower than 25mgKOH/g, heating to 150 ℃ for reflux reaction after 2 mgh at 105-120 ℃, and continuing the reaction until the detected acid value is lower than 20 mgKOH/g; and (3) evaporating xylene under reduced pressure, cooling, adding 60.0 parts of acetone, completely dissolving, adding 100.0 parts of toluene, stirring, standing to separate out a precipitate, performing suction filtration, and performing vacuum drying at 50 ℃ to obtain the purified 3 rd generation dendritic polymer HPB-3 b.

Example 3:

preparing isocyanate-acrylic acid functional monomer TDI-HEA: adding 87.0 parts of TDI-80 and 0.05 part of DBTDL into a four-neck flask provided with a reflux condenser tube, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropwise adding a mixture consisting of 58.0 parts of acrylic acid-beta-hydroxyethyl, 0.1 part of hydroquinone and 40.0 parts of acetone at 30-45 ℃, heating to 45-50 ℃ after dropwise adding, continuing to react for 4 hours, then sampling and detecting the NCO value of the system every 30 minutes, stopping the reaction when the detected NCO value is half of the initial value, and cooling to 40 ℃ to obtain the isocyanate-acrylic acid functional monomer TDI-HEA.

Example 4:

preparing isocyanate-acrylic acid functional monomer IPDI-HEMA: adding 44.5 parts of IPDI and 0.03 part of DBTDL into a four-neck flask provided with a reflux condenser, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropwise adding a mixture consisting of 26.2 parts of beta-hydroxyethyl methacrylate, 0.03 part of hydroquinone and 20.0 parts of acetone at the temperature of 30-45 ℃, heating to 45-50 ℃ to continue reacting for 3 hours after dropwise adding is finished, then sampling every 30 minutes to detect the NCO value of the system, stopping the reaction when the detected NCO value is half of the initial value, and cooling to 40 ℃ to prepare the IPDI-HEMA serving as the isocyanate-acrylic acid functional monomer.

Example 5:

preparation of 2- (2-hydroxy-) ethoxythioxanthone (HETX): adding 415mL of 98% concentrated sulfuric acid into a reaction bottle provided with a stirring device, a thermometer and a feeding device, cooling to-5-0 ℃ by using an ice salt bath, adding 153.0 parts of 2, 2' -dithiodibenzoic acid, adding 207.0 parts of ethylene glycol phenyl ether in batches under stirring, controlling the temperature to be 0-5 ℃ for reaction for 6 hours, adding 2500mL of frozen deionized water, stirring for 20 minutes, standing, performing suction filtration, adding 200mL of deionized water into a filter cake, boiling and refluxing for 2 hours, cooling, standing, performing suction filtration, washing with water, drying to obtain a crude product, recrystallizing the crude product by using 200mL of 1, 4-dioxane-water mixed solvent (volume ratio of 4:1), stirring, standing, performing suction filtration, and drying to obtain HETX.

Example 6:

preparing a thioxanthone photoinitiation group functional monomer TDI-HETX: adding 52.2 parts of TDI-80 and 0.03 part of DBTDL into a four-neck flask provided with a reflux condenser tube, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropping 82.0 parts of HETX and 25.0 parts of acetone solution at 40-45 ℃, heating to 50-60 ℃ after dropping, continuing to react for 4 hours, sampling and detecting the NCO value of the system every 30 minutes, and stopping the reaction when the detected NCO value is half of the initial value to obtain the thioxanthone photoinitiation group functional monomer TDI-HETX.

Example 7:

preparing a thioxanthone photoinitiating group functional monomer IPDI-HETX: adding 44.5 parts of IPDI and 0.03 part of DBTDL into a four-neck flask provided with a reflux condenser tube, a thermometer, a dropping funnel and a stirrer, stirring and heating, slowly dropping 54.6 parts of HETX and 20.0 parts of acetone solution at 40-45 ℃, after dropping, heating to 50-60 ℃, continuing to react for 3.5h, then sampling and detecting the NCO value of the system every 30min, and stopping the reaction when the detected NCO value is half of the initial value to obtain the thioxanthone photoinitiation group functional monomer IPDI-HETX.

Example 8:

the preparation method of the 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group comprises the following steps:

1) and preparing a dendritic prepolymer HPB-HEA containing active functional groups: adding 0.15mol of HPB-3p in example 1 into acetone, heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding a mixed solution of TDI-HEA (0.3mol and 0.6mol respectively) and hydroquinone in example 3, adding dibutyltin dilaurate after dropwise adding, continuing to react for 2-4 h at 60-70 ℃, sampling and detecting the NCO value of the system every 30min, and stopping reaction when the NCO reaction is complete to obtain HPB-HEA dendritic prepolymers A2 and A4;

2) and preparing a dendritic prepolymer HPB-HEA-HETX containing active functional groups and photoinitiating groups: stirring and heating the prepolymer A2 in the step 1) to 70-90 ℃, slowly dropwise adding a mixed solution of TDI-HETX (0.15mol and 0.3mol respectively) and hydroquinone in example 6 while stirring, then adding dibutyltin dilaurate, carrying out heat preservation reaction for 2-4 h, sampling every 30min to detect the NCO value of the system, stopping the reaction when the NCO reaction is complete, carrying out reduced pressure distillation to remove acetone, and obtaining the dendritic prepolymer HPB-HEA-HETX containing the active functional group-photoinitiating group: a2-1[ n (TDI-HEA)/n (TDI-HETX) ═ 2:1], a2-2[ n (TDI-HEA)/n (TDI-HETX) ═ 2:2 ];

the following dendritic prepolymer HPB-HEA-HETX was prepared as described above:

A4-1[n(TDI-HEA)/n(TDI-HETX)＝4:1]、A4-2[n(TDI-HEA)/n(TDI-HETX)＝4:2]；

3) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring and heating prepolymer A2-1 in the step 2) to 85-95 ℃, adding neodecanoic acid glycidyl ester E10P (0.15mol and 0.3mol respectively), adding hydroquinone, carrying out heat preservation reaction for 2-3 h, sampling every 30min, detecting the epoxy value of the system, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group:

A2-1-1[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝2:1:1]、

A2-1-2[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝2:1:2]；

preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group according to the method:

A2-2-1[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝2:2:1]、

A2-2-2[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝2:2:2]；

A4-1-1[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝4:1:1]、

A4-1-2[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝4:1:2]；

A4-2-1[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝4:2:1]、

A4-2-2[n(TDI-HEA)/n(TDI-HETX)/n(E10P)＝4:2:2]。

example 9:

1) and preparing a dendritic prepolymer HPB-HEMA containing active functional groups: adding acetone into HPB-3B (0.15mol) in the embodiment 2, heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding a mixed solution of IPDI-HEMA (0.45mol and 0.6mol respectively) and hydroquinone in the embodiment 4, adding dibutyltin dilaurate after dropwise adding, continuously reacting for 2-4 h at 60-70 ℃, then sampling and detecting the NCO value of the system every 30min, and stopping the reaction when the NCO reaction is complete to obtain HPB-HEMA dendritic prepolymers B3 and B4;

2) preparing a dendritic prepolymer HPB-HEMA-HETX containing active functional groups and photoinitiating groups: stirring and heating the prepolymer B3 or B4 in the step 1) to 70-90 ℃, slowly dropwise adding the mixed solution of IPDI-HETX (0.45mol) and hydroquinone in the example 7 under stirring, then adding dibutyltin dilaurate, carrying out heat preservation reaction for 2-4 h, sampling every 30min to detect the NCO value of the system, stopping the reaction when the NCO reaction is complete, carrying out reduced pressure distillation to remove acetone, and obtaining the dendritic prepolymer HPB-HEMA-HETX containing the active functional group-photoinitiating group: b3-3[ n (IPDI-HEMA)/n (IPDI-HEMA) ═ 3:3] or B4-3[ n (IPDI-HEMA)/n (IPDI-HEMA) ═ 4:3 ];

3) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring and heating prepolymer B3-3 or B4-3 in the step 2) to 85-95 ℃, adding neodecanoic acid glycidyl ester E10P (0.45mol), adding hydroquinone, performing heat preservation reaction for 2-3 h, sampling the epoxy value of a detection system every 30min, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group:

b3-3-3[ n (IPDI-HEMA)/n (IPDI-HETX)/n (E10P) ═ 3:3:3] or

B4-3-3[n(IPDI-HEMA)/n(IPDI-HETX)/n(E10P)＝4:3:3]。

Example 10:

1) and preparing a dendritic prepolymer HPB-HEA containing active functional groups: adding acetone into HPB-b (0.15mol) in the embodiment 2, heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding a mixed solution of TDI-HEA (0.3mol or 0.6mol) and hydroquinone in the embodiment 3, adding dibutyltin dilaurate after dropwise adding is finished, continuously reacting for 2-4 h at 60-70 ℃, sampling every 30min to detect the NCO value of the system, and stopping the reaction when the NCO reaction is complete to obtain HPB-HEA dendritic prepolymer C2 or C4;

2) and preparing a dendritic prepolymer HPB-HEA-HETX containing active functional groups and photoinitiating groups: stirring and heating the prepolymer C3 or C4 in the step 1) to 70-90 ℃, slowly dropwise adding the mixed solution of IPDI-HETX (0.6mol) and hydroquinone in the example 7 under stirring, then adding dibutyltin dilaurate, carrying out heat preservation reaction for 2-4 h, then sampling every 30min to detect the NCO value of the system, stopping the reaction when the NCO reaction is complete, carrying out reduced pressure distillation to remove acetone, and obtaining the dendritic prepolymer HPB-HEA-HETX containing the active functional group-photoinitiating group: c2-4[ n (TDI-HEA)/n (TPDI-heax) ═ 2:4 or C4-4[ n (TDI-HEA)/n (TPDI-heax) ═ 4: 4;

3) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring and heating prepolymer C2-4 or C4-4 in the step 2) to 85-95 ℃, adding neodecanoic acid glycidyl ester E10P (0.8mol), adding hydroquinone, performing heat preservation reaction for 2-3 h, sampling the epoxy value of a detection system every 30min, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group:

c2-4-4[ n (TDI-HEA)/n (IPDI-HETX)/n (E10P) ═ 2:4:4] or

C4-4-4[n(TDI-HEA)/n(IPDI-HETX)/n(E10P)＝4:4:4]。

Example 11:

1) and preparing a dendritic prepolymer HPB-HEMA containing active functional groups: adding 0.15mol of HPB-p in example 1 into acetone, heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding a mixed solution of IPDI-HEMA (0.3mol or 0.45mol) and hydroquinone in example 4, adding dibutyltin dilaurate after dropwise adding, continuing to react for 2-4 h at 60-70 ℃, sampling every 30min to detect the NCO value of the system, and stopping the reaction when the NCO reaction is complete to obtain HPB-HEMA dendritic prepolymer D2 or D3;

2) preparing a dendritic prepolymer HPB-HEMA-HETX containing active functional groups and photoinitiating groups: stirring and heating the prepolymer D2 or D3 in the step 1) to 70-90 ℃, slowly dropwise adding the mixed solution of IPDI-HETX (0.15mol) and hydroquinone in the example 6 under stirring, then adding dibutyltin dilaurate, carrying out heat preservation reaction for 2-4 h, sampling every 30min to detect the NCO value of the system, stopping the reaction when the NCO reaction is complete, carrying out reduced pressure distillation to remove acetone, and obtaining the dendritic prepolymer HPB-HEMA-HETX containing the active functional group-photoinitiating group: d2-1[ n (IPDI-HEMA)/n (IPDI-HEMA) ═ 2:1 or D3-1[ n (IPDI-HEMA)/n (IPDI-HEMA) ═ 3: 1;

3) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring and heating prepolymer D2-1 or D3-1 in the step 2) to 85-95 ℃, adding neononanoic acid glycidyl ester E9G (0.3mol), adding hydroquinone, carrying out heat preservation reaction for 2-3 h, sampling every 30min, detecting the epoxy value of the system, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating groups:

d2-1-2[ n (IPDI-HEMA)/n (IPDI-HETX)/n (E9G) ═ 2:1:2] or

D3-1-2[n(IPDI-HEMA)/n(IPDI-HETX)/n(E9G)＝3:1:2]。

Comparative example 1 of thioxanthone photoinitiating group-modified generation 3 dendritic LED resin prepared in the example of the present invention, commercial polyurethane acrylate self-initiating UV resin drewrrad 1010 (graft 2959, addition ITX), comparative example 2 of sapis hyperbranched UV resin BDT-1006 [ addition photoinitiator: 2959. ITX, 2- (N, N-diethylamino) ethanol ] were formulated into UV-LED overprint varnishes and tested according to the relevant standards, with the properties shown in Table 1:

table 1: UV-LED finishing paint performance

According to appendix A in the DB44/2129-2018 standard: the judgment method of coating odor is to carry out odor test on the performance of the coating film, and the result is as follows: the coating prepared by the embodiment of the invention has no odor; the coating prepared in comparative example 1 had a slight odor; the coating obtained in comparative example 2 had a clear odor.

Although the present invention has been described in detail and with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A preparation method of 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group is characterized by comprising the following steps: the preparation method comprises the following steps of:

e) and preparing a dendritic prepolymer HPB-HEA containing active functional groups: adding acetone into HPB-2 in the step a), heating to 60 ℃, stirring and dissolving uniformly, slowly dropwise adding a mixed solution of DI-HEA and hydroquinone in the step b), adding dibutyltin dilaurate after dropwise adding, continuously reacting for 2-4 h at 60-70 ℃, then sampling and detecting an NCO value of a system every 30min, and stopping reaction when NCO is completely reacted to obtain an HPB-HEA dendritic prepolymer;

g) preparing 3 rd generation dendritic LED resin modified by thioxanthone photoinitiating group: stirring the prepolymer in the step f), heating to 85-95 ℃, adding glycidyl versatate, then adding hydroquinone, performing heat preservation reaction for 2-4 h, sampling every 30min, detecting the epoxy value of the system, stopping the reaction when the detected epoxy value reaches a theoretical value, cooling to below 40 ℃, filtering and packaging to obtain the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group;

wherein, in the step a), the 1 st input amount is the molar ratio of the monomer containing the bis-hydroxymethyl carboxylic acid to the neopentyl glycol of 2: 1; feeding neopentyl glycol containing 4 times of mole ratio of bis (hydroxymethyl) carboxylic acid monomer at the 2 nd time; feeding neopentyl glycol containing 8 times of the molar ratio of the bis (hydroxymethyl) carboxylic acid monomer at the 3 rd time; the addition amount of the catalyst p-toluenesulfonic acid is 0.4-0.8% of the amount of the monomer containing the bis-hydroxymethyl carboxylic acid;

in step b), the molar ratio of the diisocyanate to the hydroxyl-containing acrylic monomer is 1: 1; the addition amount of the dibutyltin dilaurate is 0.05-0.1% of the amount of diisocyanate; the addition amount of the hydroquinone is 0.1-0.2% of the amount of the hydroxyl-containing acrylic monomer;

in step c), the molar ratio of the 2, 2' -dithiodibenzoic acid to the ethylene glycol phenyl ether is 1: 3; the mass ratio of the concentrated sulfuric acid to the 2, 2' -dithiodibenzoic acid is 5: 1; the volume ratio of the 1, 4-dioxane to water is 4: 1;

in step d), the molar ratio of the diisocyanate to the HETX is 1: 1; the addition amount of the dibutyltin dilaurate is 0.04-0.1% of the amount of diisocyanate;

in the step e), the molar ratio of the DI-HEA to the HPB-3 is 1-4: 1; the addition amount of the hydroquinone is 0.05-0.2% of the amount of the DI-HEA; the addition amount of the dibutyltin dilaurate is 0.02-0.08% of the amount of DI-HEA;

in the step f), the molar ratio of the DI-HETX to the HPB-3 is 1-4: 1; the addition amount of the hydroquinone is 0.05-0.2% of the amount of the DI-HETX; the addition amount of the dibutyltin dilaurate is 0.02-0.08% of the amount of DI-HETX;

2. The method of claim 1, wherein: the 3 rd generation dendritic LED resin modified by the thioxanthone photoinitiating group takes neopentyl glycol as a core, a dendritic three-dimensional structure as a shell, contains 1-4 functional active groups, 1-4 thioxanthone photoinitiating groups and 1-4 branched chain group alkane groups, and has a molecular structural formula shown as the following formula:

wherein R in the formula is

R₁Is H or CH₃；(R₂+R₃) Is an alkyl group having 6 to 8 carbon atoms.

3. The method of claim 1, wherein: the monomer containing the bis-hydroxymethyl carboxylic acid is one of 2, 2-dimethylolpropionic acid and 2, 2-dimethylolbutyric acid.

4. The method of claim 1, wherein: the diisocyanate is at least one of toluene diisocyanate TDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI and diphenylmethane diisocyanate MDI.

5. The method of claim 1, wherein: the hydroxyl-containing acrylic monomer is at least one of acrylic acid-beta-hydroxyethyl ester, methacrylic acid-alpha-hydroxyethyl ester and methacrylic acid-beta-hydroxyethyl ester.

6. The method of claim 1, wherein: the glycidyl versatate is at least one of glycidyl neononanoate, glycidyl neodecanoate and glycidyl neoundecanoate.