Isocyanate modified UV-curable epoxidized soybean oil acrylate and preparation method thereof

Abstract

The preparation method comprises the following steps: (1) adding diisocyanate, hydroxyalkyl acrylate, a catalyst and a polymerization inhibitor into a reaction container, stirring and heating to 60-90 DEG C, and reacting for 3-5 hours to obtain an intermediate product; and (2) putting the epoxidized soybean oil acrylate, a catalyst and a polymerization inhibitor into another reaction container, heating to 55-60 DEG C, gradually dropwise adding the intermediate product, reacting at 60-80 DEG C until the NCO% is less than 0.5%, adding absolute ethyl alcohol, reacting for 30 minutes, and cooling to obtain the UV-curable epoxidized soybean oil acrylate. The synthesized isocyanate modified UV-curable epoxidized soybean oil acrylate has the advantages of high crosslinking density, good flexibility, high hardness, good impact resistance, good chemical resistance and the like of a cured film, and can be applied to the fields of 3D printing, woodware coatings and the like.

Description

Technical Field

[0001] The invention relates to the field of preparation of ultraviolet-cured epoxidized oil acrylate coatings, and in particular to isocyanate-modified UV-curable epoxy soybean oil acrylate and a preparation method thereof. Background Art

[0002] UV-curable plant oil-based coating systems have become a research hotspot in the field of green coating materials due to their biodegradability and low-energy processing characteristics. Epoxidized oils themselves contain long flexible chains but lack a rigid structure, resulting in plant oil-based acrylates having the advantages of low viscosity and high flexibility, but their hardness and thermal stability are inferior to those of petroleum-based epoxy resins. Therefore, there is an urgent need to prepare high-performance UV-curable epoxidized oil acrylates, by increasing their vinyl functionality, thereby improving the performance of their cured coatings and expanding their application areas. The modification of existing epoxidized soybean oil acrylates still faces technical difficulties such as low hardness and poor toughness of the UV-cured coatings.

[0003] By introducing polyurethane resin, the impact toughness of the cured coating can be improved. For example, Chinese invention patent CN117003989A discloses a method for preparing epoxy soybean oil-based acrylate-polyurethane UV light-curing resin. The first step is to react epoxy soybean oil and acrylate at 100-130°C. After the acid value remains unchanged, the temperature is lowered to 50-80°C. Diisocyanate is added and the reaction is continued until the NCO infrared peak disappears or the NCO value is less than 0.2%, thereby obtaining a prepolymer. (2) Two acid anhydride curing agents are respectively subjected to esterification reaction with hydroxyl acrylate. The reaction is stopped when the acid anhydride infrared peak disappears. The reaction products obtained by the esterification reaction of the two acid anhydride curing agents are named mixture 1 and mixture 2 respectively. (3) Mixture 1 and mixture 2 are added to the prepolymer and cross-linked at 20-40°C for 20-60 minutes to finally obtain epoxy soybean oil-based acrylate-polyurethane UV light-curing resin. The amount of diisocyanate added here is small and is only used as a cross-linking agent to react with the hydroxyl group of epoxy soybean oil acrylate to increase the molecular weight and branched structure of the epoxy soybean oil acrylate, while also increasing the viscosity of the resin. Chinese invention patent CN118184951A discloses a method for preparing a polyurethane-modified epoxy acrylate resin, which comprises the following three steps: (1) a first addition reaction of a first hydroxy acrylate and an acid anhydride in 1,6-hexanediol diacrylate to obtain a product I containing a carboxyl group; (2) a second addition reaction of an epoxy resin and the product I containing a carboxyl group to make the epoxy group excessive relative to the carboxyl group. When the acid value in the system is ≤3 mgKOH / g, the reaction is stopped to obtain a product II containing an epoxy group; (3) a polymerization reaction of a diisocyanate, dimethylolbutyric acid, and a second hydroxy acrylate. When the -NCO group content in the system is 0, the reaction is stopped to obtain a product III having a polyurethane chain segment; (4) mixing the product II and the product III and heating them. When the acid value in the system is ≤3 mgKOH / g, the reaction is stopped to obtain the polyurethane-modified epoxy acrylate resin. The above-mentioned polyurethane chain segment is introduced into the structure, further improving the toughness of the epoxy resin and enhancing the adhesion and toughness of the resin. Here, the diisocyanate reacts with dihydroxybutyric acid and a second hydroxy acrylate to prepare a UV-curable polyurethane, and the UV-curable epoxy acrylate is modified by blending. However, the reaction process is complex, the preparation cost is high, and the product performance improvement is limited. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the present invention aims to provide a method for preparing an isocyanate-modified UV-curable epoxy soybean oil acrylate, wherein an isocyanate-hydroxyl addition reaction is carried out between an isocyanate and a hydroxyalkyl acrylate to obtain a reaction intermediate containing a vinyl group and an isocyanate group. The isocyanate group of the reaction intermediate reacts with the hydroxyl group on the epoxy soybean oil acrylate molecular chain to introduce vinyl and carbamate groups into the molecular chain of the epoxy soybean oil acrylate, thereby increasing the concentration of UV-curable vinyl groups in the epoxy soybean oil acrylate and facilitating an increase in the chemical crosslinking density. Furthermore, the introduction of carbamate bonds increases the density of physical crosslinks, such as hydrogen bonds, in the cured film, thereby improving the impact toughness of the coating film.

[0005] Another object of the present invention is to provide isocyanate-modified UV-curable epoxy soybean oil acrylate prepared by the above preparation method.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate comprises the following steps:

[0008] (1) Add diisocyanate, hydroxyalkyl acrylate, catalyst and polymerization inhibitor into a reaction vessel, stir and heat to 60-90°C, and react for 3-5 hours to obtain an intermediate product;

[0009] (2) Epoxidized soybean oil acrylate, catalyst and polymerization inhibitor are placed in another reaction vessel, heated to 55-60° C., and then the intermediate product is gradually added dropwise. The reaction is carried out at 60-80° C. until the NCO% is less than 0.5%. Anhydrous ethanol is added and reacted for 30 minutes. After cooling, UV-curable epoxy soybean oil acrylate is obtained.

[0010] Preferably, the molar ratio of the diisocyanate, hydroxyalkyl acrylate and epoxy soybean oil acrylate is 1:1:1-4.

[0011] Preferably, in step (1), the amount of the catalyst used is 0.05-0.2% of the mass fraction of the diisocyanate, and the amount of the polymerization inhibitor used is 0.05-0.25% of the mass fraction of the hydroxyalkyl acrylate.

[0012] Preferably, in step (2), the amount of the catalyst used is 0.10-0.25% of the mass fraction of the intermediate product, and the amount of the polymerization inhibitor used is 0.10-0.25% of the mass fraction of the intermediate product.

[0013] Preferably, the diisocyanate is one of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and diphenylmethane diisocyanate.

[0014] Preferably, the hydroxyalkyl acrylate is one of pentaerythritol triacrylate, glycerol dimethacrylate and hydroxyethyl acrylate.

[0015] Preferably, the catalyst is at least one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and bismuth isooctanoate.

[0016] Preferably, the polymerization inhibitor is at least one of p-hydroxyanisole, p-benzoquinone, methylhydroquinone, hydroquinone, and 2,5-dimethylhydroquinone.

[0017] The present invention also provides an isocyanate-modified UV-curable epoxy soybean oil acrylate, which is prepared by the preparation method of the isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0018] The present invention also provides a coating comprising 65-87 parts of the isocyanate-modified UV-curable epoxy soybean oil acrylate, 10-30 parts of a reactive diluent and 3-5 parts of a photoinitiator.

[0019] Preferably, the reactive diluent is one or a mixture of two of tripropylene glycol diacrylate (TPGDA), trimethylolpropane triacrylate (TMPTA), polyethylene glycol diacrylate (PEGDA), and triethylene glycol diacrylate (TEGDA).

[0020] The photoinitiator is at least one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), and 1-hydroxycyclohexyl phenyl ketone (184).

[0021] The principle of the present invention is:

[0022] The present invention uses isocyanate and hydroxyalkyl acrylate to carry out an isocyanate-hydroxyl addition reaction to obtain a reaction intermediate containing vinyl groups and isocyanate groups. Subsequently, the isocyanate groups of the reaction intermediate react with the hydroxyl groups on the molecular chain of epoxy soybean oil acrylate to introduce vinyl groups and carbamate groups into the molecular chain of epoxy soybean oil acrylate, thereby increasing the concentration of UV-curable vinyl groups in the epoxy soybean oil acrylate and facilitating the improvement of chemical crosslinking density. In addition, the introduction of carbamate bonds increases the density of physical crosslinking, such as hydrogen bonds, of the cured film, thereby improving the impact toughness of the coating film.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] (1) The present invention efficiently introduces polymerizable double bonds into the molecular chain through the synergistic reaction of hydroxyalkyl acrylate and isocyanate. This molecular design significantly increases the crosslinking network density of the cured film, resulting in water resistance and chemical resistance. Simultaneously, the introduction of urethane bonds, through hydrogen bonding, improves the toughness and impact resistance of the cured film.

[0025] (2) The resin prepared by the present invention is prepared by a two-step process of isocyanate, hydroxyalkyl acrylate, and epoxy soybean oil acrylate. The process has the characteristics of mild reaction conditions (normal temperature and pressure), simple operation, and no need for complicated post-processing. In addition, the raw materials are easily available and the cost is controllable, and it has good potential for industrial scale-up.

[0026] (3) The present invention does not require the addition of organic solvents during the synthesis process, effectively avoiding the emission of volatile organic compounds (VOCs). The resulting resin has suitable viscosity characteristics and can be directly used in subsequent formulation processing, meeting the current development requirements of green chemical industry.

[0027] (4) The resin system prepared by the present invention is suitable for a variety of coating application scenarios, including but not limited to 3D printing, plastic coatings, and ink systems. The cured coating exhibits excellent comprehensive properties: high cross-linking density brings excellent surface hardness (pencil hardness ≥ F) and water resistance, while maintaining good flexibility and impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the infrared spectrum of the isocyanate-modified UV-curable epoxy soybean oil acrylate in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

[0030] In the comparative example of each embodiment, the modified epoxy soybean oil acrylate of the present invention is replaced with the homemade standard epoxy soybean oil acrylate as the oligomer component of the UV-curable coating, and the other components and proportions are the same as those of the embodiment.

[0031] In the following examples, the properties of UV-curable resins and light-curable coatings were tested according to the following methods: the viscosity of the resin was measured using an NDJ-8 rotational viscometer in accordance with GB / T 21059-2007; the gel fraction of the coating was measured according to ASTM D2765; the hardness of the coating was measured according to GB / T 6739-2006; the adhesion of the coating was measured according to GB / T 9286-1998; the water resistance of the coating was measured by a room temperature immersion method in accordance with GB / T 5209-1985; the alcohol resistance of the coating was measured according to GB / T 1763-79; the acid / alkali resistance of the coating was measured according to GB / T 9274-2009; the impact resistance of the coating was measured using a QCJ paint film impactor in accordance with GB / T 1732-1993; and the flexibility of the coating was measured using a QTY-10A paint film bending tester in accordance with GB / T 1731-1993.

[0032] Example 1

[0033] The composition by weight of the raw material formula of the isocyanate-modified UV-curable epoxy soybean oil acrylate resin of this embodiment is shown in Table 1:

[0034]

[0035]

[0036] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0037] The first step of the reaction: first add dicyclohexylmethane diisocyanate, dimethacrylate glycerol, catalyst dibutyltin dilaurate and polymerization inhibitor p-hydroxyanisole in the above proportion into a four-necked flask, stir at a uniform speed, slowly heat to 90 ° C, keep warm for 4 hours, cool, discharge and set aside to obtain an intermediate product.

[0038] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and p-hydroxyanisole composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 80°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%. 1 ml of anhydrous ethanol is added and the reaction is carried out for half an hour to obtain isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0039] Preparation of UV curing coatings:

[0040] The configuration composition of UV curing coatings in parts by mass is shown in Table 2 below:

[0041]

[0042] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 3.

[0043] Table 3:

[0044]

[0045] As can be seen from Table 3, the isocyanate-modified UV-curable epoxy soybean oil acrylate resin obtained in the present invention significantly improves the hardness, adhesion, and impact resistance of the cured coating compared to the unmodified epoxy soybean oil acrylate, while also exhibiting excellent chemical resistance. Compared to Patent 117003989A, the present invention exhibits significant advantages in resin viscosity, coating hardness, and impact resistance. Patent 1 utilizes diisocyanate solely as a crosslinking agent, with a low addition level (less than 5%), which fails to increase the vinyl functionality of the resin or the hydrogen bond density of the cured coating, resulting in a less pronounced polyurethane modification effect. Compared to Patent 118184951A, the resin prepared in the present invention achieves a cured coating with a hardness of H, an impact resistance of 50 kg / cm, and an adhesion of Class 0, surpassing Patent 2. This is primarily due to the inclusion of a large amount of carbamate in the epoxy soybean oil acrylate, which enhances the coating's impact resistance by increasing hydrogen bonding within the polymer molecules. In addition, this patent uses bio-based materials, and the hardness of its cured coating is comparable to that of comparative patent 2.

[0046] Figure 1 This is the infrared spectrum of the isocyanate-modified UV-curable epoxy soybean oil acrylate in Example 1, where 3300 cm-1 and 1545 cm-1 are characteristic peaks of the urethane bond, indicating that the polyurethane bond has been chemically connected to the molecular chain of the epoxy soybean oil acrylate, and the isocyanate-modified AESO has been successfully prepared.

[0047] Example 2

[0048] The isocyanate-modified UV-curable epoxy soybean oil acrylate resin of this embodiment has a raw material formula and a composition in mass percentage as shown in Table 4:

[0049]

[0050] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0051] The first step of the reaction is to add the above proportion of isophorone diisocyanate, hydroxyethyl acrylate, catalyst stannous octoate and inhibitor p-benzoquinone into a four-necked flask, stir at a uniform speed, slowly heat to 90 ° C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0052] The second step reaction: the above-mentioned epoxy soybean oil acrylate, stannous octoate, and p-benzoquinone are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 90°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%. 1 ml of anhydrous ethanol is added and the temperature is kept at 90°C for 30 minutes to obtain isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0053] Preparation of UV curing coatings:

[0054] The configuration composition of UV curing coatings in parts by mass is shown in Table 5 below:

[0055]

[0056] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 6.

[0057] Table 6:

[0058]

[0059] Example 3

[0060] The isocyanate-modified UV-curable epoxy soybean oil acrylate of this embodiment has a raw material formula with a mass percentage composition as shown in Table 7:

[0061]

[0062] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0063] The first step reaction: first add the above proportion of toluene diisocyanate, pentaerythritol triacrylate, catalyst bismuth isooctanoate and polymerization inhibitor 2,5-dimethylhydroquinone into a four-necked flask, stir at a uniform speed, slowly heat to 60°C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0064] The second step reaction: the above-mentioned epoxy soybean oil acrylate, bismuth isooctanoate, 2,5-dimethylhydroquinone are added into a four-necked flask equipped with a mechanical stirrer, a thermometer and a condenser, and the intermediate product obtained in the first step reaction is slowly added into the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0065] Preparation of UV curing coatings:

[0066] The configuration composition of UV curing coatings in parts by mass is shown in Table 8 below:

[0067]

[0068] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 9.

[0069] Table 9:

[0070]

[0071]

[0072] Example 4

[0073] The isocyanate-modified UV-curable epoxy soybean oil acrylate of this embodiment has a raw material formula with a mass percentage composition as shown in Table 10:

[0074]

[0075] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0076] The first step of the reaction: first add the above proportion of toluene diisocyanate, hydroxyethyl acrylate, catalyst dibutyltin diacetate and polymerization inhibitor hydroquinone into a four-necked flask, stir at a uniform speed, slowly heat to 60 ° C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0077] The second step reaction: the epoxy soybean oil acrylate, dibutyltin diacetate, and hydroquinone composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0078] Preparation of UV curing coatings:

[0079] The configuration composition of UV curing coatings in parts by mass is shown in Table 11 below:

[0080]

[0081]

[0082] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 12.

[0083] Table 12:

[0084]

[0085] Example 5

[0086] The isocyanate-modified UV-curable epoxy soybean oil acrylate resin of this embodiment has a raw material formula with a mass percentage composition as shown in Table 13:

[0087]

[0088]

[0089] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0090] The first step of the reaction: first add the above proportion of toluene diisocyanate, glycerol dimethacrylate, catalyst dibutyltin dilaurate and inhibitor methylhydroquinone into a four-necked flask, stir at a uniform speed, slowly heat to 60 ° C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0091] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and methylhydroquinone composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0092] Preparation of UV curing coatings:

[0093] The configuration composition of UV curing coatings in parts by mass is shown in Table 14 below:

[0094]

[0095] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 15.

[0096] Table 15:

[0097]

[0098]

[0099] Example 6

[0100] The isocyanate-modified UV-curable epoxy soybean oil acrylate of this embodiment has a raw material formula with a mass percentage composition as shown in Table 16:

[0101]

[0102] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0103] The first step of the reaction is to add the above proportion of isophorone diisocyanate, glycerol dimethacrylate, catalyst dibutyltin dilaurate and polymerization inhibitor p-hydroxyanisole into a four-necked flask, stir at a uniform speed, slowly heat to 60 ° C, keep warm for 4 hours, cool, discharge and set aside to obtain an intermediate product.

[0104] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and p-hydroxyanisole composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0105] Preparation of coating:

[0106] The configuration composition of UV curing coatings in parts by mass is shown in Table 17 below:

[0107]

[0108] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 18.

[0109] Table 18:

[0110]

[0111] Example 7

[0112] The isocyanate-modified UV-curable epoxy soybean oil acrylate of this embodiment has a raw material formula with a mass percentage composition as shown in Table 19:

[0113]

[0114]

[0115] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0116] The first step reaction: first add the above proportion of isophorone diisocyanate, pentaerythritol triacrylate, catalyst dibutyltin dilaurate and inhibitor p-hydroxyanisole into a four-necked flask, stir at a uniform speed, slowly heat to 60°C, keep warm for 4 hours, cool, discharge and set aside to obtain an intermediate product.

[0117] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and p-hydroxyanisole composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0118] Preparation of UV curing coatings:

[0119] The configuration composition of UV curing coatings in parts by mass is shown in Table 20 below:

[0120]

[0121] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 21.

[0122] Table 21:

[0123]

[0124]

[0125] Example 8

[0126] The isocyanate-modified UV-curable epoxy soybean oil acrylate resin of this embodiment has a raw material formula with a mass percentage composition as shown in Table 22:

[0127]

[0128] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0129] The first step of the reaction: first, add the above proportion of 4,4'-dicyclohexylmethane diisocyanate, hydroxyethyl acrylate, catalyst dibutyltin dilaurate and polymerization inhibitor p-hydroxyanisole into a four-necked flask, stir at a uniform speed, slowly heat to 60 ° C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0130] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and p-hydroxyanisole composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0131] Preparation of UV curing coatings:

[0132] The configuration composition of UV curing coatings in parts by mass is shown in Table 23:

[0133]

[0134] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 24.

[0135] Table 24:

[0136]

[0137] Example 9

[0138] The isocyanate-modified UV-curable epoxy soybean oil acrylate resin of this embodiment has a raw material formula with a mass percentage composition as shown in Table 25:

[0139]

[0140] Preparation process of isocyanate-modified UV-curable epoxy soybean oil acrylate in this embodiment:

[0141] The first step of the reaction is to add the above proportion of 4,4'-dicyclohexylmethane diisocyanate, pentaerythritol triacrylate, catalyst dibutyltin dilaurate and polymerization inhibitor p-hydroxyanisole into a four-necked flask, stir at a uniform speed, slowly heat to 60 ° C, keep warm for 4 hours, cool down, discharge and set aside to obtain an intermediate product.

[0142] The second step reaction: the epoxy soybean oil acrylate, dibutyltin dilaurate, and p-hydroxyanisole composed above are added to a four-necked flask equipped with a mechanical stirrer, a thermometer, and a condenser. The intermediate product obtained in the first step reaction is slowly added to the flask. The temperature is maintained at 60°C and the reaction is carried out for 4 hours until the NCO% is lower than 0.5%, thereby obtaining isocyanate-modified UV-curable epoxy soybean oil acrylate.

[0143] Preparation of UV curing coatings:

[0144] The configuration composition of UV curing coatings in parts by mass is shown in Table 26:

[0145]

[0146] Add the components of the above formula to the mixing container and disperse them by stirring at a low speed of 600r / min for 10-15 minutes. After the coating system is completely defoamed, use a four-sided wet film preparation device to coat the surface of wood, glass and tinplate substrates, and control the wet film thickness to 25±2μm. Then place the coating film under the output power of 600mW / cm 2 The cured coating was cured in a UV curing device with a wavelength of 365 nm. The performance of the cured coating was tested and compared with the test results of Comparative Example 1 (unmodified epoxy soybean oil acrylate coating AESO). Specific performance data are shown in Table 27.

[0147] Table 27:

[0148]

[0149] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate, characterized in that: The following steps are involved: (1) Add diisocyanate, hydroxyalkyl acrylate, catalyst and polymerization inhibitor into a reaction vessel, stir and heat to 60-90°C, and react for 3-5 hours to obtain an intermediate product; (2) Epoxidized soybean oil acrylate, catalyst and polymerization inhibitor are placed in another reaction vessel, heated to 55-60° C., and then the intermediate product is gradually added dropwise. The reaction is carried out at 60-80° C. until the NCO% is less than 0.5%. Anhydrous ethanol is added and reacted for 30 minutes. After cooling, UV-curable epoxy soybean oil acrylate is obtained.

2. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, wherein: The molar ratio of the diisocyanate, hydroxyalkyl acrylate and epoxy soybean oil acrylate is 1:1:1-4.

3. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, characterized in that: In step (1), the amount of the catalyst used is 0.05-0.2% of the mass fraction of the diisocyanate, and the amount of the polymerization inhibitor used is 0.05-0.25% of the mass fraction of the hydroxyalkyl acrylate.

4. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, wherein: In step (2), the amount of the catalyst used is 0.10-0.25% of the mass fraction of the intermediate product, and the amount of the polymerization inhibitor used is 0.10-0.25% of the mass fraction of the intermediate product.

5. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, characterized in that: The diisocyanate is one of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and diphenylmethane diisocyanate.

6. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, characterized in that: The hydroxyalkyl acrylate is one of pentaerythritol triacrylate, glycerol dimethacrylate and hydroxyethyl acrylate.

7. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, characterized in that: The catalyst is at least one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and bismuth isooctanoate.

8. The method for preparing isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 1, characterized in that: The polymerization inhibitor is at least one of p-hydroxyanisole, p-benzoquinone, methylhydroquinone, hydroquinone, and 2,5-dimethylhydroquinone.

9. Isocyanate modified UV curable epoxy soybean oil acrylate, characterized in that: The acrylate is prepared by the preparation method of the isocyanate-modified UV-curable epoxy soybean oil acrylate according to any one of claims 1 to 8.

10. A coating, characterized in that: The invention comprises 65-87 parts of the isocyanate-modified UV-curable epoxy soybean oil acrylate according to claim 9, 10-30 parts of a reactive diluent and 3-5 parts of a photoinitiator.

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