阅读说明：本技术 一种uv固化高光涂料及其制备方法 (UV-cured high-gloss coating and preparation method thereof ) 是由 郑少琴 徐宁 谢进标 谢铠烨 于 2021-01-28 设计创作，主要内容包括：一种UV固化高光涂料,其特征在于由下述重量配比的原料制成：异氰酸酯20-60%,扩链树脂5-25%,交联树脂5-20%,活性聚硅氧烷5-15%,扩链剂0.5-5%,交联剂0.1-0.5%,催化剂0.02-0.2%,羟基丙烯酸酯1-10%,多官能丙烯酸酯单体10-30%,光引发剂0.5-5%,流平剂0.5-1%,消泡剂0.1－0.2%,抗静电剂0.2-2%,偶联剂0.5-2%。本发明还提供上述UV固化高光涂料的一种制备方法。本发明的UV固化高光涂料用于复合转移工艺生产高光纸,纸张表面光泽度高,耐热性好,耐折性好,涂层与纸张附着力好,与模压膜有良好的剥离性,生产成本低,符合节能环保和安全卫生要求。(The UV-curing high-gloss coating is characterized by being prepared from the following raw materials in parts by weight: 20-60% of isocyanate, 5-25% of chain extension resin, 5-20% of cross-linking resin, 5-15% of active polysiloxane, 0.5-5% of chain extender, 0.1-0.5% of cross-linking agent, 0.02-0.2% of catalyst, 1-10% of hydroxyl acrylate, 10-30% of multifunctional acrylate monomer, 0.5-5% of photoinitiator, 0.5-1% of flatting agent, 0.1-0.2% of defoaming agent, 0.2-2% of antistatic agent and 0.5-2% of coupling agent. The invention also provides a preparation method of the UV-cured high-gloss coating. The UV-cured high-gloss coating is used for producing high-gloss paper by a composite transfer process, has high surface gloss of the paper, good heat resistance, good folding resistance, good adhesion of a coating and the paper, good stripping property with a molded film and low production cost, and meets the requirements of energy conservation, environmental protection, safety and sanitation.)

1. The UV-curing high-gloss coating is characterized by being prepared from the following raw materials in parts by weight: 20-60% of isocyanate, 5-25% of chain extension resin, 5-20% of cross-linking resin, 5-15% of active polysiloxane, 0.5-5% of chain extender, 0.1-0.5% of cross-linking agent, 0.02-0.2% of catalyst, 1-10% of hydroxyl acrylate, 10-30% of multifunctional acrylate monomer, 0.5-5% of photoinitiator, 0.5-1% of flatting agent, 0.1-0.2% of defoaming agent, 0.2-2% of antistatic agent and 0.5-2% of coupling agent.

2. The UV-curable high gloss coating of claim 1, wherein: the isocyanate is one or more of isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate and HDI trimer.

3. The UV-curable high gloss coating of claim 1, wherein: the chain extension resin is polyether diamine, polyether diol, polyester diol or polyaspartic acid ester.

4. The UV-curable high gloss coating of claim 1, wherein: the crosslinking resin is a polyether polyol having a molecular weight of 200-1000.

5. The UV-curable high gloss coating of claim 1, wherein: the active polysiloxane is aminopropyl terminated polydimethylsiloxane or alcohol hydroxyl terminated dimethyl siloxane, and the molecular weight of the active polysiloxane is 500-4000.

6. The UV-curable high gloss coating of claim 1, wherein: the chain extender is 1, 4-butanediol, neopentyl glycol, diethylene glycol, bisphenol A, isophorone diamine, ethylene diamine or phenylenediamine.

7. The UV-curable high gloss coating of claim 1, wherein: the cross-linking agent is glycerol, pentaerythritol or trimethylolpropane.

8. The UV-curable high gloss coating of claim 1, wherein: the catalyst is dibutyltin dilaurate, stannous octoate, potassium isooctanoate or bismuth catalyst;

the hydroxy acrylic ester is hydroxyethyl acrylate or hydroxyethyl methacrylate;

the multifunctional acrylate monomer is tripropylene glycol diacrylate, trimethylolpropane triacrylate or dipentaerythritol pentaacrylate;

the photoinitiator is a free radical photoinitiator or a cationic photoinitiator; the free radical photoinitiator is diphenylethanedione, dibenzoyl or benzophenone;

the leveling agent is polyether siloxane copolymer;

the defoaming agent is a polyether defoaming agent;

the antistatic agent is a cationic antistatic agent, an anionic antistatic agent, a nonionic antistatic agent or a high molecular antistatic agent;

the coupling agent is a silane coupling agent KH 560.

9. The method for preparing the UV-curable high-gloss paint according to claim 1, comprising the steps of:

(1) the following raw materials are prepared by weight: 20-60% of isocyanate, 5-25% of chain extension resin, 5-20% of cross-linking resin, 5-15% of active polysiloxane, 0.5-5% of chain extender, 0.1-0.5% of cross-linking agent, 0.02-0.2% of catalyst, 1-10% of hydroxyl acrylate, 10-30% of multifunctional acrylate monomer, 0.5-5% of photoinitiator, 0.5-1% of flatting agent, 0.1-0.2% of defoaming agent, 0.2-2% of antistatic agent and 0.5-2% of coupling agent;

(2) respectively adding the chain-extending resin and the cross-linking resin into a water removal reaction kettle with a stirrer and a vacuum water removal system to remove water contained in the chain-extending resin and the cross-linking resin;

(3) adding the chain-extended resin with water removed into a polymerization reaction kettle, dropwise adding isocyanate while stirring, heating to 70-85 ℃, and reacting for 0.5-2 hours; then adding the dehydrated crosslinking resin, and reacting for 1-4 hours at 70-85 ℃;

(4) regulating the temperature in the polymerization reaction kettle to 55-70 ℃, adding active polysiloxane, and reacting for 0.5-3 hours at 65-70 ℃;

(5) regulating the temperature in the polymerization reaction kettle to 55-70 ℃, adding hydroxyl acrylate and a catalyst, heating to 70-80 ℃, and reacting for 0.5-3 hours;

(6) regulating the temperature in a polymerization reaction kettle to 55-70 ℃, adding a chain extender and a cross-linking agent, heating to 70-80 ℃, and reacting for 1-4 hours;

(7) and (3) adjusting the temperature in the polymerization reaction kettle to 50-70 ℃, adding a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a leveling agent, a defoaming agent and a coupling agent, and stirring for 20-60 minutes to obtain the UV-cured high-gloss coating.

10. The method for preparing the UV-curable high-gloss paint according to claim 9, wherein: in the step (2), the chain-extending resin and the cross-linking resin are respectively added into a water removal reaction kettle with a stirrer and a vacuum water removal system, and then heated to 100-130 ℃ under the condition of stirring, and water is pumped for 1-3 hours under the vacuum degree of-0.01 MPa to-0.02 MPa, so as to remove the water contained therein.

Technical Field

The invention relates to a coating composition, in particular to a UV-cured high-gloss coating and a preparation method thereof.

Background

The aircraft glass cardboard is also called as cast-coated paper, and the traditional processing method is that the base paper coated with the coating is stuck and pressed on the surface of a heated chrome-plated drying cylinder with high polishing and mirror luster, and then the processed paper is dried and stripped. Because the paper surface is smooth and bright like glass, the paper is also called as glass paperboard and is commonly called as high gloss paper. The high-gloss paper as a high-end packaging material is widely applied to the external packaging of high-end products such as cosmetics, medicines, health products, high-grade cigarettes and wines, and has very large market demand potential.

At present, the high-gloss paper produced at home and abroad has the traditional cast coating process and the composite transfer process.

The traditional cast coating process has the defects of relatively complex process, large equipment investment, high control precision requirement, thick coating, low production line speed, high production cost and the like, and the produced high-gloss paper has certain defects of glossiness, folding resistance, adhesive force, printing and gold stamping performance.

The composite transfer process is a new process for producing highlight paper, which is developed in recent years in China, and comprises the steps of coating highlight paint on paper, then compounding the paper with a film with a smooth surface (such as a PET film, an OPP film and the like), stripping a recovered film after curing, and utilizing the smooth surface of the film to mold a coating so as to enable the surface of the paper to be smooth and bright to form the highlight paper. The process has the advantages of simple equipment, easy operation, thin coating and high production speed. The high gloss paint used for the composite transfer process in the current market is mainly water-based acrylic, and high gloss paper produced by the high gloss paint has low glossiness, insufficient folding resistance, poor heat resistance, long production line and high cost.

Disclosure of Invention

The invention aims to solve the technical problem of providing a UV-cured high-gloss coating and a preparation method thereof, the UV-cured high-gloss coating is used for producing high-gloss paper by a composite transfer process, the surface gloss of the paper is high, the heat resistance is good, the folding resistance is good, the adhesion between a coating and the paper is good, the stripping performance with a molded film is good, the production cost is low, and the requirements of energy conservation, environmental protection, safety and sanitation are met. The technical scheme is as follows:

the UV-curing high-gloss coating is characterized by being prepared from the following raw materials in parts by weight: 20-60% of isocyanate, 5-25% of chain extension resin, 5-20% of cross-linking resin, 5-15% of active polysiloxane, 0.5-5% of chain extender, 0.1-0.5% of cross-linking agent, 0.02-0.2% of catalyst, 1-10% of hydroxyl acrylate, 10-30% of multifunctional acrylate monomer, 0.5-5% of photoinitiator, 0.5-1% of flatting agent, 0.1-0.2% of defoaming agent, 0.2-2% of antistatic agent and 0.5-2% of coupling agent.

The isocyanate is used as a hard segment part of the high-gloss coating, and endows the transfer adhesive with the properties of strength, temperature resistance and the like. The isocyanate generally adopts non-yellowing isocyanate which does not turn yellow under the irradiation of ultraviolet light, and is favorable for preventing the high-gloss paint from turning yellow under the irradiation of ultraviolet light. In a preferred embodiment, the isocyanate is one or more of isophorone diisocyanate (IPDI), 4' -dicyclohexylmethane diisocyanate (HMDI), toluene diisocyanate, Hexamethylene Diisocyanate (HDI), and HDI trimer. More preferably, the isocyanate is 4,4' -dicyclohexylmethane diisocyanate (HMDI), and the HMDI can reduce the reaction speed of polyurethane and ensure the molecular weight consistency and regularity of the prepolymer.

The chain-extended resin is used as a soft segment component of the high-gloss coating, so that the high-gloss coating is endowed with flexibility. Preferably, the chain extension resin may be a polyether diamine (e.g., polyoxyethylene ether diamine, polyoxypropylene ether diamine having a molecular weight of 200-. The polyether is selected from DDL-400, DDL-1000, DDL-220, etc. of German Federal, and the polyester diol is selected from PE-3010, PE-3020, PE-3030, etc. having a gorgeon group. More preferably, the chain-extended resin is a polyether diamine having a molecular weight of 2000.

The cross-linked resin is used as a cross-linked soft segment component, so that the soft segment content and cross-linking points can be increased, and the strength, hardness and glossiness of the high-gloss coating are improved. Preferably, the crosslinking resin is a polyether polyol having a molecular weight of 200-1000, such as a polyether polyol having glycerol, pentaerythritol, sorbitol or sucrose as an initiator (e.g., Monocarb's designations YNW-6205, YNW-305, YNW-380, etc.). More preferably, the crosslinking resin is a sorbitol polyether polyol having a molecular weight of 400 and a functionality of 3.5.

The active polysiloxane endows the film strippability of the high-gloss paint with high heat resistance, and reduces damage to a coating and a molded film caused by static electricity during stripping. Preferably, the reactive polysiloxane is aminopropyl terminated polydimethylsiloxane or alcoholic hydroxyl terminated dimethylsiloxane, the molecular weight of which is 500-4000. More preferably, the above-mentioned reactive polysiloxane is an α, ω -dihydroxyhydrocarbyl polysiloxane having a molecular weight of 1000.

The chain extender is used for increasing the molecular weight and the hard segment content of the polymer, and low molecular weight dihydric alcohol or diamine is generally adopted. Preferably, the chain extender is 1, 4-butanediol, neopentyl glycol, diethylene glycol, bisphenol A, isophorone diamine, ethylene diamine or phenylene diamine. More preferably, the chain extender is a diol or neopentyl glycol.

The crosslinking agent is used for improving the molecular weight and the hard segment content of the polymer. The crosslinking agent is usually a small-molecule polyol. Preferably, the crosslinking agent is glycerol, pentaerythritol or trimethylolpropane. More preferably, the crosslinking agent is trimethylolpropane.

The catalyst is used for catalyzing the reaction of isocyanate, chain-extending resin, cross-linking resin, active polysiloxane and hydroxyl acrylate. Preferably, the catalyst is dibutyltin dilaurate, stannous octoate, potassium isooctanoate or bismuth-based catalyst. More preferably, the catalyst is stannous octoate.

The hydroxyl acrylate is bridging resin of polyurethane and acrylate, and the end hydroxyl reacts with NCO of polyurethane prepolymer to be grafted into unsaturated resin. Preferably, the hydroxy acrylate is hydroxyethyl acrylate or hydroxyethyl methacrylate. More preferably, the hydroxy acrylate is hydroxyethyl methacrylate.

The multifunctional acrylate monomer is an active diluent, so that the viscosity of a high-gloss coating system is reduced, the construction performance is improved, and the UV curing performance is endowed; and provides cross-linked double bonds to impart strength and wear resistance to the product. The above multifunctional acrylate monomer may be a difunctional, trifunctional or tetrafunctional acrylate, and a trifunctional acrylate is preferred. Preferably, the multifunctional acrylate monomer is tripropylene glycol diacrylate, trimethylolpropane triacrylate or dipentaerythritol pentaacrylate.

The photoinitiator is a UV photoinitiator, and the coating after coating construction is crosslinked and cured under the action of the initiator and UV light to form good product performance. The photoinitiator may be a radical photoinitiator (e.g., diphenylethyldione, dibenzoyl, benzophenone, etc.) or a cationic photoinitiator. Preferably, the photoinitiator is benzophenone.

Preferably, the leveling agent is a polyether siloxane copolymer, such as TEGO Glide 410.

Preferably, the defoamer is a polyether defoamer, such as TEGO Foamex 805 defoamer, Digao.

The antistatic agent is used for reducing static generated when a mould pressing film is stripped after a product is coated and cured, and the product quality and the production safety are improved. The antistatic agent may be a cationic antistatic agent, an anionic antistatic agent, a nonionic antistatic agent or a polymeric antistatic agent. Preferably, the antistatic agent is a polyurethane polymer antistatic agent (JL-WT).

The coupling agent can improve the adhesive force between the coating and paper and improve the printing adaptability of the coating. Preferably, the coupling agent is a silane coupling agent KH 560.

The invention adopts a multi-step method to synthesize polyurethane, and adds a multifunctional acrylate monomer to adjust the viscosity. Firstly, chain extension resin and cross-linked resin are dewatered at a certain temperature and vacuum degree, then isocyanate reacts with the chain extension resin, the cross-linked resin, active polysiloxane, hydroxyl acrylate, a micromolecule chain extender and a cross-linking agent respectively, after the reaction is finished, cooling is carried out, then a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a flatting agent, a defoaming agent and a coupling agent are added, after uniform mixing, a product can be obtained and discharged, and the product is sealed and stored in a dark place.

The invention also provides a preparation method of the UV-cured high-gloss paint, which is characterized by comprising the following steps:

(1) the following raw materials are prepared by weight: 20-60% of isocyanate, 5-25% of chain extension resin, 5-20% of cross-linking resin, 5-15% of active polysiloxane, 0.5-5% of chain extender, 0.1-0.5% of cross-linking agent, 0.02-0.2% of catalyst, 1-10% of hydroxyl acrylate, 10-30% of multifunctional acrylate monomer, 0.5-5% of photoinitiator, 0.5-1% of flatting agent, 0.1-0.2% of defoaming agent, 0.2-2% of antistatic agent and 0.5-2% of coupling agent;

(2) respectively adding the chain-extending resin and the cross-linking resin into a water removal reaction kettle with a stirrer and a vacuum water removal system to remove water contained in the chain-extending resin and the cross-linking resin;

(3) adding the chain-extended resin with water removed into a polymerization reaction kettle, dropwise adding isocyanate while stirring, heating to 70-85 ℃, and reacting for 0.5-2 hours; then adding the dehydrated crosslinking resin, and reacting for 1-4 hours at 70-85 ℃;

(4) regulating the temperature in the polymerization reaction kettle to 55-70 ℃, adding active polysiloxane, and reacting for 0.5-3 hours at 65-70 ℃;

(5) regulating the temperature in the polymerization reaction kettle to 55-70 ℃, adding hydroxyl acrylate and a catalyst, heating to 70-80 ℃, and reacting for 0.5-3 hours;

(6) regulating the temperature in a polymerization reaction kettle to 55-70 ℃, adding a chain extender and a cross-linking agent, heating to 70-80 ℃, and reacting for 1-4 hours;

(7) and (3) adjusting the temperature in the polymerization reaction kettle to 50-70 ℃, adding a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a leveling agent, a defoaming agent and a coupling agent, and stirring for 20-60 minutes to obtain the UV-cured high-gloss coating.

Preferably, in the step (2), the chain-extended resin and the crosslinked resin are respectively added into a water removal reaction kettle with a stirrer and a vacuum water removal system, and then heated to 100-130 ℃ under the condition of stirring, and water is pumped for 1-3 hours under the vacuum degree of-0.01 MPa to-0.02 MPa, so as to remove the water contained therein.

And (7) filtering and discharging the UV-cured high-gloss coating obtained in the step (7), and sealing, shading and storing.

The high-gloss coating synthesized by the invention utilizes the advantages of the flexibility of polyurethane, the weather resistance of acrylate and the like, and the product has the advantages of high brightness, strong adhesive force, folding resistance, temperature resistance, wear resistance, abrasion resistance, small unit coating amount, low cost, safety, environmental protection, aging resistance, no toxicity, no harm and the like.

The UV-cured highlight coating is non-toxic and harmless, has small environmental pollution and meets the environmental protection requirement; after the high-gloss paper is manufactured and is subsequently processed (such as printing, gold stamping and the like), the high-gloss paper has the advantages of embossing resistance, solvent resistance, water resistance, folding resistance, explosion resistance, strong adhesive force, good flatness and leveling property and the like, no organic volatile matters are separated out after UV irradiation, and the high-gloss paper is low in cost, non-toxic, harmless and tasteless, is an ideal environment-friendly high-gloss packaging material, is suitable for packaging any solid matters, and better meets the requirements of the industries such as national tobacco, food, medicine and the like.

Detailed Description

Example 1

In this embodiment, the preparation method of the UV-curable high-gloss coating includes the following steps:

(1) the following raw materials are prepared by weight: 36% of isocyanate (4, 4' -dicyclohexylmethane diisocyanate), 15% of chain extending resin (polyaspartic acid ester (trade name: Qixiang Q420) with molecular weight 560), 10% of crosslinking resin (polyether polyol (trade name: Norway YNW-8343) with sucrose with molecular weight 595 as initiator), 10% of active polysiloxane (alpha, omega-dihydroxy alkyl polysiloxane with molecular weight 1000), 2% of chain extender (neopentyl glycol), 0.3% of crosslinking agent (trimethylolpropane), 0.1% of catalyst (stannous octoate), 3% of hydroxyl acrylate (hydroxyethyl acrylate 15 kg), 20% of multifunctional acrylate monomer (trimethylolpropane triacrylate), 2% of photoinitiator (benzophenone), 0.6% of leveling agent (polyether siloxane copolymer, TEGO Glide 410 with digao), defoaming agent 0.2% (both polyether type defoaming agent and TEGO Foamex 805 with digao), antistatic agent 0.2% (both polyurethane polymer antistatic agents) and coupling agent 0.6% (both silane coupling agent KH 560);

(2) adding the chain-extended resin and the cross-linked resin into a water removal reaction kettle with a stirrer and a vacuum water removal system respectively, and removing water contained in the resin (after adding the chain-extended resin and the cross-linked resin into the water removal reaction kettle with the stirrer and the vacuum water removal system respectively, heating to 120 ℃ under the stirring condition, pumping water for 2 hours under the vacuum degree of-0.01 MPa, and removing the water contained in the resin);

(3) adding the chain-extended resin with water removed into a polymerization reaction kettle, dropwise adding isocyanate while stirring, heating to 70-85 ℃, and reacting for 1 hour; then adding the dehydrated crosslinking resin, and reacting for 2 hours at 70-85 ℃;

(4) adjusting the temperature in the polymerization reaction kettle to 65 ℃, adding active polysiloxane, and reacting for 1 hour at 65-70 ℃;

(5) regulating the temperature in a polymerization reaction kettle to 65 ℃, adding hydroxyl acrylate and a catalyst, heating to 70-80 ℃, and reacting for 1 hour;

(6) regulating the temperature in a polymerization reaction kettle to 65 ℃, adding a chain extender and a cross-linking agent, heating to 70-80 ℃, and reacting for 2 hours;

(7) and (3) adjusting the temperature in the polymerization reaction kettle to 60 ℃, adding a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a leveling agent, a defoaming agent and a coupling agent, and stirring for 30 minutes to obtain the UV-cured high-gloss coating.

And (7) filtering and discharging the UV-cured high-gloss coating obtained in the step (7), and sealing, shading and storing.

Example 2

In this embodiment, the preparation method of the UV-curable high-gloss coating includes the following steps:

(1) the following raw materials are prepared by weight: 55% of isocyanate (both toluene diisocyanate), 5% of chain extension resin (both polyoxyethylene ether diol (trade name: onowei YNW-220) with molecular weight of 2000), 15% of crosslinking resin (both polyoxypropylene ether triol (trade name: dchan DMN-500) with molecular weight of 500), 6% of active polysiloxane (both aminopropyl terminated polydimethylsiloxane with molecular weight of 1000), 3% of chain extender (both bisphenol a), 0.1% of crosslinking agent (both trimethylolpropane), 0.2% of catalyst (both stannous octoate), 2% of hydroxyl acrylate (both hydroxyethyl methacrylate), 10% of polyfunctional acrylate monomer (both trimethylolpropane triacrylate), 0.6% of photoinitiator (both diphenylethanedione), 1% of leveling agent (both polyether siloxane copolymer and digao Glide 410), 0.1% of defoaming agent (all polyether defoaming agent, high TEGO Foamex 805 defoaming agent), 1% of antistatic agent (all polyurethane high molecular antistatic agent) and 1% of coupling agent (all silane coupling agent KH 560);

(2) adding the chain-extended resin and the cross-linked resin into a water removal reaction kettle with a stirrer and a vacuum water removal system respectively, and removing water contained in the resin (after adding the chain-extended resin and the cross-linked resin into the water removal reaction kettle with the stirrer and the vacuum water removal system respectively, heating to 100 ℃ under the stirring condition, pumping water for 1.5 hours under the vacuum degree of-0.02 MPa, and removing the water contained in the resin);

(3) adding the chain-extended resin with water removed into a polymerization reaction kettle, dropwise adding isocyanate while stirring, heating to 70-85 ℃, and reacting for 2 hours; then adding the dehydrated crosslinking resin, and reacting for 3 hours at 70-85 ℃;

(4) regulating the temperature in the polymerization reaction kettle to 60 ℃, adding active polysiloxane, and reacting for 1.5 hours at 65-70 ℃;

(5) regulating the temperature in the polymerization reaction kettle to 60 ℃, adding hydroxyl acrylate and a catalyst, heating to 70-80 ℃, and reacting for 1.5 hours;

(6) regulating the temperature in a polymerization reaction kettle to 60 ℃, adding a chain extender and a cross-linking agent, heating to 70-80 ℃, and reacting for 3 hours;

(7) and (3) adjusting the temperature in the polymerization reaction kettle to 55 ℃, adding a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a leveling agent, a defoaming agent and a coupling agent, and stirring for 50 minutes to obtain the UV-cured high-gloss coating.

And (7) filtering and discharging the UV-cured high-gloss coating obtained in the step (7), and sealing, shading and storing.

Example 3

In this embodiment, the preparation method of the UV-curable high-gloss coating includes the following steps:

(1) the following raw materials are prepared by weight: 21% of isocyanate (all hexamethylene diisocyanate tripolymer), 20% of chain-extended resin (all polyoxyethylene ether diamine with the molecular weight of 430 (trade name: Delphin Federal ZD 140)), 5% of cross-linked resin (all sorbitol polyether polyol with the molecular weight of 400 and the functionality of 3.5), 5% of active polysiloxane (all alpha, omega-dihydroxy alkyl polysiloxane with the molecular weight of 1000), 4% of chain extender (all 1, 4-butanediol), 0.5% of cross-linking agent (all trimethylolpropane), 0.05% of catalyst (all dibutyltin dilaurate), 10% of hydroxyl acrylate (all hydroxyethyl acrylate), 25% of multifunctional acrylate monomer (all tripropylene glycol diacrylate), 5% of photoinitiator (all dibenzoyl), 0.8% of flatting agent (all polyether siloxane copolymer, Digao TEGO Glide 410), 0.15% of defoaming agent (all polyether defoaming agent, high TEGO Foamex 805 defoaming agent), 2% of antistatic agent (all polyurethane high molecular antistatic agent) and 1.5% of coupling agent (all silane coupling agent KH 560);

(2) adding the chain-extended resin and the cross-linked resin into a water removal reaction kettle with a stirrer and a vacuum water removal system respectively, and removing water contained in the resin (after adding the chain-extended resin and the cross-linked resin into the water removal reaction kettle with the stirrer and the vacuum water removal system respectively, heating to 120 ℃ under the stirring condition, pumping water for 1.5 hours under the vacuum degree of-0.01 MPa, and removing the water contained in the resin);

(3) adding the chain-extended resin with water removed into a polymerization reaction kettle, dropwise adding isocyanate while stirring, heating to 70-85 ℃, and reacting for 1 hour; then adding the dehydrated crosslinking resin, and reacting for 2 hours at 70-85 ℃;

(4) adjusting the temperature in the polymerization reaction kettle to 65 ℃, adding active polysiloxane, and reacting for 1 hour at 65-70 ℃;

(5) regulating the temperature in a polymerization reaction kettle to 65 ℃, adding hydroxyl acrylate and a catalyst, heating to 70-80 ℃, and reacting for 1 hour;

(6) regulating the temperature in a polymerization reaction kettle to 65 ℃, adding a chain extender and a cross-linking agent, heating to 70-80 ℃, and reacting for 2 hours;

(7) and (3) adjusting the temperature in the polymerization reaction kettle to 60 ℃, adding a multifunctional acrylate monomer, a photoinitiator, an antistatic agent, a leveling agent, a defoaming agent and a coupling agent, and stirring for 45 minutes to obtain the UV-cured high-gloss coating.

And (7) filtering and discharging the UV-cured high-gloss coating obtained in the step (7), and sealing, shading and storing.

The UV-curable high gloss coatings of examples 1 to 3 and the high gloss coating products of the existing market were uniformly coated on cardboard, respectively, and combined with an OPP film, and the resulting composite was exposed to light for 10 seconds under a high-pressure UV mercury lamp with a power of 1000W, and the OPP film was peeled off and recovered. The test indexes of examples 1 to 3 and the existing market products are shown in the following table. As can be seen from the table, the surface gloss, adhesion, folding resistance, heat resistance and printing adaptability of the high gloss coating prepared by the invention are superior to those of the market products.