阅读说明：本技术 一种紫外光固化型绿色聚酯丙烯酸酯树脂、组合物及其制备 (Ultraviolet-curing green polyester acrylate resin, composition and preparation thereof ) 是由 李建波 潘学仪 于 2020-12-09 设计创作，主要内容包括：本发明涉及一种紫外光固化型绿色聚酯丙烯酸酯树脂、组合物及其制备,该聚酯丙烯酸树脂的制备过程具体为：(1)取聚酯单体加入反应釜中,再加入二元醇和辛酸亚锡,在惰性气体保护下反应,得到聚酯二元醇；(2)往聚酯二元醇中加入阻聚剂并分散,随后加入丙烯酸酐或甲基丙烯酸酐,继续在惰性气体下反应,反应结束后除去残余小分子,即得到目的产物。与现有技术相比,本发明的树脂以生物基乳酸等形成主体结构,其组合物作为光固化材料,除了具有固含量高、低气味、不含有机溶剂,可在紫外光辐射下快速固化的特点,还有较好的涂层性能是一种优质的绿色环保型树脂材料,可用于功能型涂料、胶黏剂等的研发和生产应用。(The invention relates to an ultraviolet light curing type green polyester acrylate resin, a composition and a preparation method thereof, wherein the preparation process of the polyester acrylate resin comprises the following steps: (1) adding a polyester monomer into a reaction kettle, adding dihydric alcohol and stannous octoate, and reacting under the protection of inert gas to obtain polyester dihydric alcohol; (2) adding a polymerization inhibitor into the polyester diol, dispersing, then adding acrylic anhydride or methacrylic anhydride, continuing to react under inert gas, and removing residual micromolecules after the reaction is finished to obtain the target product. Compared with the prior art, the resin disclosed by the invention has the main structure formed by bio-based lactic acid and the like, the composition of the resin is used as a photocuring material, and the resin has the characteristics of high solid content, low odor, no organic solvent and capability of being rapidly cured under ultraviolet radiation, and the coating has better coating performance, is a high-quality green environment-friendly resin material, and can be used for research, development, production and application of functional coatings, adhesives and the like.)

1. A preparation method of ultraviolet light curing type green polyester acrylate resin is characterized by comprising the following steps:

(1) adding a polyester monomer into a reaction kettle, adding dihydric alcohol and stannous octoate, and reacting under the protection of inert gas to obtain polyester dihydric alcohol;

(2) adding a polymerization inhibitor into the polyester diol, dispersing, then adding acrylic anhydride or methacrylic anhydride, continuing to react under inert gas, and removing residual micromolecules after the reaction is finished to obtain the target product.

2. The method for preparing the ultraviolet-curable green polyester acrylate resin according to claim 1, wherein in the step (1), the polyester monomer is one or more of L-lactide, D, L-lactide and epsilon-caprolactone;

the dihydric alcohol is one or more of ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol, 1, 4-cyclohexanedimethanol and 1, 4-benzenedimethanol.

3. The preparation method of the ultraviolet-curable green polyester acrylate resin according to claim 1, wherein in the step (1), the mass ratio of the polyester monomer, the diol and the stannous octoate is as follows:

100 parts of polyester monomer, namely 100 parts of,

3-35 parts of dihydric alcohol,

0.0001-0.001 part of stannous octoate.

4. The method for preparing the ultraviolet-curable green polyester acrylate resin according to claim 1, wherein in the step (1), the reaction temperature is 120 ℃ and the reaction time is 6-24 hours.

5. The method for preparing ultraviolet curing type green polyester acrylate resin according to claim 1, wherein in the step (2), the polymerization inhibitor is one or more of p-hydroxyanisole, hydroquinone and 2, 6-di-tert-butyl-4-methylphenol.

6. The method for preparing the ultraviolet-curable green polyester acrylate resin according to claim 1, wherein in the step (2), the mass ratio of the polyester diol, the polymerization inhibitor and the acrylic anhydride or the methacrylic anhydride is as follows:

100 parts of polyester diol, namely 100 parts of polyester diol,

10-65 parts of acrylic anhydride or methacrylic anhydride,

0.2-0.5 part of polymerization inhibitor.

7. The method for preparing an ultraviolet light curing type green polyester acrylate resin according to claim 1, wherein in the step (2), the reaction temperature is 120 ℃ and the reaction time is 3-5 hours.

8. An ultraviolet light curing type green polyester acrylate resin, which is prepared by the preparation method of any one of claims 1 to 7, and is characterized in that the polyester acrylate resin is a polyester acrylate resin containing an end capping of an acrylate structure.

9. An ultraviolet light curing type green polyester acrylate resin composition is characterized by comprising the following components in parts by weight:

100 parts of the polyester acrylate resin according to claim 8;

3-5 parts of a free radical type ultraviolet initiator;

10-30 parts of reactive diluent.

10. The method for preparing the ultraviolet-curing green polyester acrylate resin composition as claimed in claim 9, wherein the polyester acrylate resin is added into a mixing kettle, heated to 40-60 ℃ and kept for 10-20 minutes, then the free radical type ultraviolet initiator and the reactive diluent are added, stirred uniformly, vacuumed to remove bubbles, and then placed into a container for packaging, thus obtaining the target product.

Technical Field

The invention belongs to the technical field of high polymer materials, and relates to ultraviolet-curing type green polyester acrylate resin, a composition and preparation thereof.

Background

The ultraviolet curing technology is a curing technology which realizes the rapid film formation on the surface of a substrate by quickly converting a liquid substance into a solid substance under the irradiation of ultraviolet light. The ultraviolet curing material has excellent macroscopic mechanical property and is widely applied to the fields of coatings, adhesives, microelectronics, dental restoration, biological materials and the like.

The oligomer is an important component of an ultraviolet curing system and determines the curing rate, the curing degree, the crosslinking density, the flexibility, the hardness, the bonding strength, the shrinkage rate and other properties of a cured product. The (methyl) acrylic resin is a kind of oligomer with the largest use amount in the field of photocuring at present, accounts for about 82 percent of the whole photocuring market, and is mainly based on epoxy resin and polyurethane structures. The epoxy acrylate is obtained by esterifying epoxy group of epoxy resin and (methyl) acrylic acid or acrylic acid containing hydroxyl, is a photo-curing oligomer with the largest consumption in the domestic photo-curing industry at present, and has the advantages of good chemical corrosion resistance, strong adhesive force, high hardness, low price and the like. The polyurethane acrylate is prepared by reacting hydroxyl-terminated macromolecules such as dihydric alcohol (or polyhydric alcohol) and diisocyanate to obtain a-NCO-terminated prepolymer, and then reacting the prepolymer with an acrylate monomer.

CN 111875780A of Shenzhen Feiyangxing science and technology Limited discloses a preparation method of polyacid modified epoxy acrylic UV resin, which comprises the steps of reacting dicarboxylic acid with epoxy resin to obtain prepolymer, and reacting the prepolymer with an acrylic-based compound to obtain polyacid modified epoxy acrylic UV resin. The UV resin can be rapidly cured at room temperature, and the cured product has good impact resistance and hardness, and can be widely applied to the fields of furniture paint, 3D printing and the like.

CN 110092885A of Jiangsu Ruipu resin science and technology Limited discloses a preparation method of UV light-cured polyurethane acrylic resin, which comprises the steps of mixing polyester diol, diisocyanate and catalyst, reacting under the stirring condition of 65-75 ℃ until the content of isocyanic acid group is 50% of the initial concentration, adding polymerization inhibitor and hydroxy acrylic ester for reaction until the content of isocyanic acid group is less than 0.05%, and obtaining the UV light-cured polyurethane acrylic resin. The obtained polyurethane acrylic resin has good adhesive force and surface hardness after being cured, and has excellent flexibility and water resistance.

The existing acrylate UV resin is basically derived from the traditional petrochemical resources. The development of green sustainable bio-based materials is receiving increasing attention today with increasing environmental pollution and crude oil shortages. Although the two UV resins described in the above patents have faster curing speed and better coating performance, the raw materials are mainly derived from petroleum-based materials, and the green environmental protection aspect of the product still has great defects.

Polyester acrylate is also an acrylate resin used in a large amount, and has the outstanding advantages of low price, low viscosity and good compatibility with other resins compared with other oligomers. But the curing shrinkage is higher, so that the product has the defects of unstable size, low photocuring rate, poor chemical stability and the like in the shaping process, and the application field of the product is limited. However, the polyester acrylate oligomer grows very rapidly in recent years, has stronger functionality, and is more and more important to be applied in the field of adhesives, such as the introduction of ether bonds on the main chain of the polyester acrylate or the introduction of aromatic rings as side chains to improve the curing rate and the like.

CN 109734885 a of ansqing north chemical science and technology park ltd discloses a preparation method of cationic waterborne polyester acrylate photocuring resin, which comprises the steps of reacting a hydroxyl-containing compound with maleic anhydride, then carrying out a ring-opening reaction with glycidyl methacrylate, carrying out michael addition reaction on active secondary amine and resin, introducing a tertiary amine structure, and ionizing the tertiary amine structure through quaternary ammonium salt reaction to obtain the cationic waterborne polyester acrylate photocuring resin. The prepared resin has a compact cross-linked network, and the mechanical property of the coating after curing is good. The light-cured resin is used in water-based products, water is required to be added into the products as a solvent, so that the solid content of the light-cured resin is low, the surface drying is slow, and meanwhile, the finishing preparation is simple.

Disclosure of Invention

The invention aims to provide ultraviolet-curing type green polyester acrylate resin, a composition and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme:

one of the technical schemes of the invention provides a preparation method of ultraviolet curing type green polyester acrylate resin, which comprises the following steps:

(1) adding a polyester monomer into a reaction kettle, adding dihydric alcohol and stannous octoate, and reacting under the protection of inert gas to obtain polyester dihydric alcohol;

(2) adding a polymerization inhibitor into the polyester diol, dispersing, then adding acrylic anhydride or methacrylic anhydride, continuing to react under inert gas, and removing residual micromolecules after the reaction is finished to obtain the target product.

Further, the number average molecular weight of the polyester diol obtained in the step (1) is 500-2000.

Further, in the step (1), the polyester monomer is one or more of L-lactide, D, L-lactide and epsilon-caprolactone.

Further, in the step (1), the diol is one or more of ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol, 1, 4-cyclohexanedimethanol and 1, 4-benzenedimethanol.

Further, in the step (1), the addition amounts of the polyester monomer, the dihydric alcohol and the stannous octoate are in the following relationship:

100 parts of polyester monomer, namely 100 parts of,

3-35 parts of dihydric alcohol,

0.0001-0.001 part of stannous octoate.

Further, in the step (1), the reaction temperature is 120 ℃, and the reaction time is 6-24 hours.

Further, in the step (2), the polymerization inhibitor is one or more of p-hydroxyanisole, hydroquinone and 2, 6-di-tert-butyl-4-methylphenol.

Further, in the step (2), the addition amounts of the polyester diol, the polymerization inhibitor and the acrylic anhydride or the methacrylic anhydride are as follows:

100 parts of polyester diol, namely 100 parts of polyester diol,

10-65 parts of acid anhydride (namely acrylic anhydride or methacrylic anhydride),

0.2-1 part of polymerization inhibitor.

Further, in the step (2), the reaction temperature is 120 ℃, and the reaction time is 3-5 hours.

The second technical scheme of the invention provides ultraviolet curing type green polyester acrylate resin which is prepared by the preparation method, and is characterized in that the polyester acrylate resin is polyester acrylate resin containing an end capping of an acrylate structure.

One of the technical schemes of the invention provides an ultraviolet curing type green polyester acrylate resin composition, which comprises the following components in percentage by weight: 100 parts of polyester acrylate resin, 3-5 parts of free radical type ultraviolet initiator and 10-30 parts of reactive diluent.

Further, the free radical type ultraviolet light initiator is one or more of 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl acetone, 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-acetone and 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide.

Further, the reactive diluent is one or more of trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate and 1, 6-hexanediol diacrylate.

The invention provides a preparation method of an ultraviolet light curing type green polyester acrylate resin composition, which comprises the steps of firstly adding polyester acrylate resin into a mixing kettle, heating to 40-60 ℃ and keeping for 10-20 minutes, then adding a free radical type ultraviolet light initiator and an active diluent, uniformly stirring, removing bubbles in vacuum, and then putting into a container for packaging to obtain a target product.

The final performance of the photocuring resin is greatly influenced by the polyester monomer, the lactide used in the invention belongs to a bio-based raw material prepared from lactic acid generated by a biological fermentation method, the prepared polylactic acid resin has high strength and high hardness, the prepared polycaprolactone resin has good flexibility and good compatibility, and the prepared polylactic acid-caprolactone copolymer has good flexibility while keeping high strength; the randomly copolymerized polyester may effectively reduce the viscosity of the polylactic acid-based resin. The dihydric alcohol is used as an initiator to initiate the polymerization of the polyester monomer to prepare the polyester acrylate resin containing two terminal hydroxyl groups.

In addition, the reaction conditions also have great influence on the whole reaction process, for example, if the reaction temperature is too low, the reaction time is prolonged, so that the production period is prolonged, and the production efficiency is reduced; too high reaction temperature may lead to increased side reactions and even gelation of the reaction system.

Compared with the prior art, the resin disclosed by the invention has the main structure formed by bio-based lactic acid and the like, the composition of the resin is used as a photocuring material, and the resin has the characteristics of high solid content, low odor, no organic solvent and capability of being rapidly cured under ultraviolet radiation, and the coating has better coating performance, is a high-quality green environment-friendly resin material, and can be used for research, development, production and application of functional coatings, adhesives and the like.

Drawings

FIG. 1 is an IR spectrum of a resin composition of example 1 after curing with a polylactic acid diol, a polylactic acid acrylate and UV light;

FIG. 2 is a nuclear magnetic spectrum of polycaprolactone diol and polycaprolactone methacrylate in example 3;

FIG. 3 is an IR spectrum of a resin composition of example 2 after curing with poly (lactic acid-caprolactone) diol, poly (lactic acid-caprolactone) methacrylate and UV light;

FIG. 4 shows the nuclear magnetic spectra of the polylactic acid-caprolactone diol and the polylactic acid-caprolactone methacrylate in example 2.

Detailed Description

The above-described scheme is further illustrated below with reference to specific examples. It should be understood that these examples are for illustrative purposes and are not intended to limit the scope of the present invention. The conditions used in the examples can be further adjusted according to the conditions of the particular manufacturers, and the conditions not specified are generally the conditions in the routine experiments, and the raw materials not specified are also the conventional commercial products in the art.

The L-lactide, D-lactide and D, L-lactide selected in the following examples were provided by Tonglira biomaterials Inc. of Shanghai, the selected epsilon-caprolactone, ethylene glycol, butylene glycol, neopentyl glycol and hexylene glycol were obtained from Adama reagent Inc., the selected stannous octoate was obtained from Tokyo chemical industries, the selected p-hydroxyanisole, hydroquinone and 2, 6-di-tert-butyl-4-methylphenol were obtained from Tatanke technology Inc. of Shanghai, the selected acrylic anhydride and methacrylic anhydride were obtained from Adama reagent Inc., the selected 1-hydroxy-cyclohexyl-phenyl methanone, 2-hydroxy-2-methyl-1-phenyl acetone, 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1 Acetone and 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide were obtained from Tianjin Jieshi Chemicals, and selected trimethylolpropane triacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate and 1, 6-hexanediol diacrylate were obtained from Yankee Chemicals.

Example 1:

100 parts of L-lactide, namely 100 parts of L-lactide,

22 parts of butanediol, namely adding a solvent into the mixture,

0.001 part of stannous octoate, namely,

weighing L-lactide and butanediol according to the formula of the components, adding the L-lactide and the butanediol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 10 hours at 120 ℃ under the protection of nitrogen to obtain the polylactic acid dihydric alcohol.

100 parts of polylactic acid dihydric alcohol,

0.2 part of hydroquinone, 0.2 part of phenol,

60 parts of acrylic anhydride, namely 60 parts of acrylic anhydride,

adding hydroquinone into the polylactic acid dihydric alcohol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding acrylic anhydride, reacting for 4 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules by reduced pressure distillation after the reaction is finished, thus obtaining the polylactic acid acrylate resin.

100 parts of polylactic acid acrylate resin,

3 parts of 1-hydroxy-cyclohexyl-phenyl ketone,

20 parts of trimethylolpropane triacrylate,

adding the polylactic acid acrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 1-hydroxy-cyclohexyl-phenyl ketone and trimethylolpropane triacrylate after the viscosity is reduced, uniformly stirring, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polylactic acid acrylate resin composition.

And casting the polylactic acid acrylate resin composition into a curing mould, and placing the curing mould into a UV curing machine for curing to obtain a cured sample. After Fourier infrared spectrum test and NMR test, the polylactic acid acrylate resin is successfully prepared, and the composition is completely cured.

Example 2:

weighing epsilon-caprolactone, L-lactide and butanediol according to the formula, adding the epsilon-caprolactone, the L-lactide and the butanediol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 12 hours at 120 ℃ under the protection of nitrogen to obtain the polylactic acid-caprolactone dihydric alcohol.

100 portions of polylactic acid-caprolactone dihydric alcohol

0.4 part of p-hydroxyanisole

Methacrylic anhydride 37 parts

Adding p-hydroxyanisole into polylactic acid-caprolactone dihydric alcohol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding methacrylic anhydride, reacting for 5 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules through reduced pressure distillation after the reaction is finished, thus obtaining the polylactic acid-caprolactone methacrylate resin.

Adding the polylactic acid-caprolactone methacrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 2-hydroxy-2-methyl-1-phenyl acetone, trimethylolpropane triacrylate and tripropylene glycol diacrylate after the viscosity is reduced, uniformly stirring, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polylactic acid-caprolactone methacrylate resin composition.

And (3) casting the polylactic acid-caprolactone methacrylate resin composition into a curing mould, and placing the curing mould into a UV curing machine for curing to obtain a cured sample. After Fourier infrared spectrum test and NMR test, the polylactic acid-caprolactone methacrylate resin is successfully prepared, and the composition is completely cured.

Example 3:

100 parts of epsilon-caprolactone,

7.5 parts of neopentyl glycol,

0.001 part of stannous octoate, namely,

weighing epsilon-caprolactone and neopentyl glycol according to the formula, adding the epsilon-caprolactone and the neopentyl glycol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 8 hours at 120 ℃ under the protection of nitrogen to obtain polycaprolactone diol.

100 parts of polycaprolactone dihydric alcohol by weight,

0.3 part of 2, 6-di-tert-butyl-4-methylphenol,

25 parts of methacrylic anhydride,

and continuously adding 2, 6-di-tert-butyl-4-methylphenol into polycaprolactone diol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding methacrylic anhydride, reacting for 3.5 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules through reduced pressure distillation after the reaction is finished to obtain the polycaprolactone methacrylate resin.

And adding the polycaprolactone methacrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping the temperature for 15 minutes, adding 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-acetone, trimethylolpropane triacrylate and dipropylene glycol diacrylate after the viscosity is reduced, stirring uniformly, standing, removing bubbles in vacuum, adding into a container, and encapsulating to obtain the polycaprolactone methacrylate resin composition.

And casting the polycaprolactone methacrylate resin composition into a curing mold, and placing the curing mold into a UV curing machine for curing to obtain a cured sample. After Fourier infrared spectrum test and NMR test, the polycaprolactone methacrylate resin is successfully prepared, and the composition is completely cured.

Example 4:

100 portions of D-lactide

Ethylene glycol 3.2 parts

0.001 part of stannous octoate

Weighing D-lactide and ethylene glycol according to the formula, adding the D-lactide and the ethylene glycol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 11 hours at 120 ℃ under the protection of nitrogen to obtain polylactic acid dihydric alcohol;

100 portions of polylactic acid dihydric alcohol

0.25 portion of hydroquinone

Acrylic anhydride 15 parts

Adding hydroquinone into the polylactic acid dihydric alcohol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding acrylic anhydride, reacting for 4.5 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules by reduced pressure distillation after the reaction is finished, thus obtaining the polylactic acid acrylate resin.

Adding the polylactic acid acrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, trimethylolpropane triacrylate and 1, 6-hexanediol diacrylate after the viscosity is reduced, stirring uniformly, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polylactic acid acrylate resin composition.

And casting the polylactic acid acrylate resin composition into a curing mould, and placing the curing mould into a UV curing machine for curing to obtain a cured sample. After Fourier infrared spectrum test and NMR test, the polylactic acid acrylate resin is successfully prepared, and the composition is completely cured.

Example 5:

weighing epsilon-caprolactone, L-lactide and butanediol according to the formula, adding the epsilon-caprolactone, the L-lactide and the butanediol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 11 hours at 120 ℃ under the protection of nitrogen to obtain the polylactic acid-caprolactone dihydric alcohol.

100 portions of polylactic acid-caprolactone dihydric alcohol

0.2 part of p-hydroxyanisole

Methacrylic anhydride 36 parts

Continuously adding p-hydroxyanisole into polylactic acid-caprolactone dihydric alcohol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding methacrylic anhydride, reacting for 4 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules through reduced pressure distillation after the reaction is finished, thus obtaining the polylactic acid-caprolactone methacrylate resin.

100 parts of polylactic acid-caprolactone methacrylate resin

3 parts of 1-hydroxy-cyclohexyl-phenyl-methanone

Trimethylolpropane triacrylate 20 parts

Adding the polylactic acid-caprolactone methacrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 1-hydroxy-cyclohexyl-phenyl ketone and trimethylolpropane triacrylate when the viscosity is reduced, uniformly stirring, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polylactic acid-caprolactone methacrylate resin composition.

And (3) casting the polylactic acid-caprolactone methacrylate resin composition into a curing mould, and placing the curing mould into a UV curing machine for curing to obtain a cured sample. After Fourier infrared spectrum test and NMR test, the polylactic acid-caprolactone methacrylate resin is successfully prepared, and the composition is completely cured.

Example 6:

epsilon-caprolactone 100 parts

31 parts of hexanediol

0.001 part of stannous octoate

Taking epsilon-caprolactone and hexanediol according to the formula, adding the epsilon-caprolactone and the hexanediol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 9 hours at 120 ℃ under the protection of nitrogen to obtain polycaprolactone diol.

100 portions of polycaprolactone dihydric alcohol

0.45 part of 2, 6-di-tert-butyl-4-methylphenol

Acrylic anhydride 60 parts

And continuously adding 2, 6-di-tert-butyl-4-methylphenol into polycaprolactone diol according to the above formula direction, pre-dispersing for 10 minutes under stirring, then adding acrylic anhydride, reacting for 5 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules through reduced pressure distillation after the reaction is finished to obtain the polycaprolactone acrylate resin.

And adding polycaprolactone acrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 2-hydroxy-2-methyl-1-phenyl acetone, trimethylolpropane triacrylate and tripropylene glycol diacrylate after the viscosity is reduced, stirring uniformly, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polycaprolactone acrylate resin composition.

And casting the polycaprolactone acrylate resin composition into a curing mold, and placing the curing mold into a UV curing machine for curing to obtain a cured sample. Through Fourier infrared spectrum test and NMR test, the polycaprolactone acrylate resin is successfully prepared, and the composition is completely cured.

Example 7:

taking epsilon-caprolactone, L-lactide and butanediol according to the formula, adding the epsilon-caprolactone, the L-lactide and the butanediol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 11 hours at 120 ℃ under the protection of nitrogen to obtain the lactic acid-polycaprolactone diol.

100 portions of polylactic acid-caprolactone dihydric alcohol

0.5 part of hydroquinone

Methacrylic anhydride 35 parts

And continuously adding hydroquinone into the polylactic acid-caprolactone dihydric alcohol according to the preparation direction, pre-dispersing for 10 minutes under stirring, then adding methacrylic anhydride, reacting for 4 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules by reduced pressure distillation after the reaction is finished to obtain the polylactic acid-caprolactone methacrylate resin.

Adding the polylactic acid-caprolactone methacrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-acetone, trimethylolpropane triacrylate and dipropylene glycol diacrylate after the viscosity is reduced, stirring uniformly, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polylactic acid-caprolactone methacrylate resin composition.

And (3) casting the polylactic acid-caprolactone methacrylate resin composition into a curing mould, and placing the curing mould into a UV curing machine for curing to obtain a cured sample. Fourier infrared spectrum test and NMR test show that the poly soft caprolactone methacrylate resin is successfully prepared, and the composition is completely cured.

Example 8:

epsilon-caprolactone 100 parts

Neopentyl glycol 5.5 parts

0.001 part of stannous octoate

Taking epsilon-caprolactone and neopentyl glycol according to the formula, adding the epsilon-caprolactone and the neopentyl glycol into a reaction kettle with a stirring device, adding stannous octoate, and reacting for 10 hours at 120 ℃ under the protection of nitrogen to obtain polycaprolactone diol;

100 portions of polycaprolactone dihydric alcohol

0.35 part of p-hydroxyanisole

Acrylic anhydride 15 parts

And continuously adding p-hydroxyanisole into polycaprolactone diol according to the above distribution direction, pre-dispersing for 10 minutes under stirring, then adding acrylic anhydride, reacting for 3 hours at 120 ℃ under the protection of nitrogen, and removing residual micromolecules through reduced pressure distillation after the reaction is finished to obtain the polycaprolactone acrylate resin.

And adding the polycaprolactone acrylate resin into a reaction kettle of a stirring device according to the formula, heating to 50 ℃, keeping for 15 minutes, adding 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, trimethylolpropane triacrylate and 1, 6-hexanediol diacrylate after the viscosity of the polycaprolactone acrylate resin is reduced, stirring uniformly, standing, removing bubbles in vacuum, adding into a container, and packaging to obtain the polycaprolactone acrylate resin composition.

And casting the polycaprolactone acrylate resin composition into a curing mold, and placing the curing mold into a UV curing machine for curing to obtain a cured sample. Through Fourier infrared spectrum test and NMR test, the polycaprolactone acrylate resin is successfully prepared, and the composition is completely cured.

Example 9:

compared to example 1, is largely identical except that the L-lactide is replaced by an equal mass of D, L-lactide.

Example 10:

compared to example 1, the majority are the same, except that butanediol is replaced with an equimolar amount of 1, 4-cyclohexanedimethanol, respectively.

Example 11:

compared to example 1, the majority are the same, except that butanediol is replaced with an equimolar amount of 1, 4-benzenedimethanol, respectively.

Comparative example 1:

compared to example 1, the same is for the most part true, except that the acrylic anhydride is changed to an equal mass of maleic anhydride.

Comparative example 2:

compared with example 1, most of them are the same except that the addition of the polymerization inhibitor is omitted.

Performance testing

Molecular weight: the molecular weight of the polyester acrylate resin was determined by Agilent 1260 type liquid chromatograph.

Viscosity: the viscosity of the polyester acrylate resin at a temperature of 25 ℃ was measured using a Brookfield model DV-I rotational viscometer.

The form is as follows: the physical form of the polyester acrylate resin was visually observed at 25 ℃.

Coating adhesion: the cured coatings were tested according to ISO 2409:1992 International Standard, using the Baige method.

Coating pencil hardness: the hardness of the paint film was determined by the pencil method according to GB/T6739-2006.

Coating flexibility: the flexibility of the coating after curing was determined according to GB/T1731-1993.

Coating contact angle: contact angles of the coatings after curing were measured using a Datophysics-OCA 20 measurement.

The cured properties of the polyester acrylate resins obtained in examples 1 to 8 and the compositions thereof were tested, and the results are shown in the following chart and table 1.

Wherein, fig. 1 is an infrared spectrum of the polylactic acid diol, the polylactic acid acrylate and the resin composition after ultraviolet light curing prepared in example 1, wherein, (a) the polylactic acid diol, (b) the polylactic acid acrylate and (c) the resin composition after ultraviolet light curing. The concentration of polylactic acid diol is 3508cm^-1The strong and wide absorption peak of the free OH proves the successful synthesis of the hydroxyl-terminated prepolymer; after the end group esterification modification is carried out on the polylactic acid dihydric alcohol by adopting methacrylic anhydride, the infrared spectrogram of the polylactic acid dihydric alcohol has a plurality of obvious changes compared with the polylactic acid dihydric alcohol: 1630cm^-1An unsaturated C ═ C stretching vibration characteristic peak appears; ② 816cm^-1And 940cm^-1In which unsaturation is present ═ CH₂Bending vibration and stretching vibration absorption peaks ofTherefore, after the modification of the acrylic anhydride, the terminal hydroxyl groups of the polylactic acid dihydric alcohol are successfully replaced by the acrylate groups. After UV curing, the characteristic absorption peaks of the C ═ C double bonds and ═ C — H bonds of the resin diminished and disappeared, indicating that after curing, C ═ C free radical polymerization occurred under the action of the active free radicals, indicating that the curing of the resin was relatively complete.

FIG. 2 is a nuclear magnetic spectrum of polycaprolactone diol and polycaprolactone methacrylate prepared in example 3, wherein (a) is polycaprolactone diol, and (b) is polycaprolactone methacrylate. In a nuclear magnetic spectrum, the polycaprolactone diol has characteristic peaks at chemical shifts of 1.42ppm, 1.67ppm, 2.36ppm and 4.07ppm respectively, and the peaks are methylene CH in a chain segment₂The main chain structure of the prepolymer is verified to be polycaprolactone caused by H in the formula (1); and the peak at 3.62ppm is methylene CH at the position adjacent to the hydroxyl on the end group of polycaprolactone₂Caused by H in (1), and conforms to the structural characteristics of the hydroxyl-terminated polycaprolactone diol. In the nuclear magnetic spectrum of polycaprolactone methacrylate, new characteristic peaks appear at 5.67ppm and 6.22ppm, corresponding to methylene CH directly connected with C ═ C double bond on methacrylate group₂Two protons, the terminal hydroxyl group of polycaprolactone diol was successfully replaced by methacrylate group.

Fig. 3 is an infrared spectrum of the polylactic acid-caprolactone diol, the polylactic acid-caprolactone methacrylate and the resin composition after uv curing prepared in example 2, wherein (a) is the polylactic acid-caprolactone diol, (b) is the polylactic acid-caprolactone acrylate, and (c) is the resin composition after uv curing. 1750cm^-1Where is the stretching vibration peak of C ═ O, 1180cm^-1Is the C-O-C stretching vibration peak at 2950cm^-1Is of the formula-CH₃1455cm^-1And 1359cm^-1Is represented by-CH₃The bending vibration peak of (a) indicates that a polylactic acid segment is present in the copolymer; the spectrum is at 740cm^-1Nearby weak absorption peak is-CH₂The peak of flexural vibration of-evidences the presence of polycaprolactone segments in the copolymer. And the absorption peak of C ═ O is a single peak, it can be confirmed that the synthesized copolymer is a random copolymer. 3500cm^-1The absorption peak of free OH is strong and wide, which proves the successful synthesis of the hydroxyl-terminated polylactic acid-caprolactone diol. Similar to FIG. 1, the infrared spectrum of polylactic acid-caprolactone methacrylate is 816cm^-1And 940cm^-1In which unsaturation is present ═ CH₂Bending vibration and stretching vibration absorption peaks prove that the terminal hydroxyl of the polylactic acid-caprolactone dihydric alcohol is successfully replaced by the acrylate; after UV light curing, the characteristic peaks of the double bonds disappear again, which indicates that the resin has undergone curing reaction.

FIG. 4 shows the nuclear magnetic spectra of polylactic acid-caprolactone diol and polylactic acid-caprolactone methacrylate prepared in example 2, wherein (a) is polylactic acid-caprolactone diol and (b) is polylactic acid-caprolactone acrylate. In the nuclear magnetic spectrum of polylactic acid-caprolactone dihydric alcohol, the chemical shift of 5.14ppm is the proton peak of methine-CH-in the polylactic acid chain segment, and the chemical shift of 1.57ppm is the methyl CH in the polylactic acid chain segment₃A proton peak of (a); chemical shifts 1.38ppm, 1.64ppm, 2.30ppm and 4.05ppm are all methylene CH in polycaprolactone segment₂Indicates that the prepolymer is a copolymer consisting of polylactic acid and polycaprolactone; in addition, two smaller characteristic peaks appear at the chemical shifts of 3.56ppm and 4.21ppm respectively, which correspond to methylene CH at the tail end of polycaprolactone chain adjacent to hydroxyl₂The mesoproton peak and the proton peak in methine CH at the position adjacent to the hydroxyl on the end group of the polylactic acid chain indicate that the polylactic acid and polycaprolactone chain segments in the molecular chain of the prepolymer are randomly arranged at the end group, belong to random copolymers and meet the structural characteristics of the hydroxyl-terminated polylactic acid-caprolactone dihydric alcohol. In the nuclear magnetic spectrum of polylactic acid-caprolactone methacrylate, new characteristic peaks appear at 6.17ppm,5.60ppm and 1.86ppm, which respectively correspond to methylene CH directly connected with C ═ C double bond on methacrylate group₂And methyl CH₃The proton peak in (1) proves that the terminal hydroxyl group of the polylactic acid-caprolactone dihydric alcohol is successfully substituted by the methacrylate group.

TABLE 1

As can be seen from Table 1, the UV-curable green polyester acrylate of the present invention has excellent coating properties. The polylactic acid chain segment can improve the hardness and the adhesive force of the resin coating, and the polycaprolactone chain segment can improve the flexibility of the resin coating; while a decrease in molecular weight results in an increase in coating hardness and a decrease in flexibility. The coating has better flexibility, hardness and adhesive force on the whole. As can be seen in comparative example 1, maleic anhydride increased the viscosity of the resin and failed to cure effectively under uv radiation; as seen from comparative example 2, the storage stability of the resin was deteriorated without adding a polymerization inhibitor, and polymerization occurred earlier during the synthesis or during storage and transportation, thereby causing gelation and being unusable.

In the above embodiments, the raw material formulas can be optionally adjusted within the following mixture ratio ranges as required, that is, can be optionally adjusted to be end values or middle point values of the corresponding ranges:

the embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.