Process for the preparation and use of branched cycloaliphatic special modified acrylate resins

Abstract

The application discloses a preparation method and application of branched alicyclic special modified acrylate resin, and the preparation method comprises the following steps: S1. branched alicyclic epoxy compounds, acrylic compounds, a first catalyst, a polymerization inhibitor and a solvent are mixed, reaction is carried out by increasing temperature, the acid value of the reaction system is monitored, the acid value of the reaction system is less than 2 mg KOH / g, a Lewis acid is added, purification is carried out, and a mixed branched alicyclic modified special acrylate is obtained; S2. the mixed branched alicyclic modified special acrylate is mixed with a diacid anhydride, a second catalyst, a polymerization inhibitor and a solvent, reaction is carried out by increasing temperature, and branched alicyclic special modified acrylate resin is obtained; the functional group molar ratio of the branched alicyclic epoxy compounds to the acrylic compounds is 1:0.8-0.9; the branched alicyclic special modified acrylate resin prepared by the preparation method can be applied to alkali developing PCB solder mask ink, and is expected to be applied in 5G materials.

Description

Technical Field

[0001] This invention belongs to the field of photosensitive polymer materials, and particularly relates to the preparation method and application of branched alicyclic modified acrylate resins. Background Technology

[0002] Photocurable phenolic epoxy acrylate resin is the main resin in traditional solder resist inks. Currently, this main resin can only meet the needs of traditional applications such as 3G or 4G communication technologies. Due to its shortcomings such as poor high-temperature resistance, poor resistance to tin melting, and poor acid resistance, and its dielectric constant Dk≈3.8, it is difficult to meet the requirements of PCB solder resist inks, conformal coatings, and adhesives in the rapidly developing 5G communication technology.

[0003] Alicyclic epoxy resins, due to the direct attachment of epoxy groups to the alicyclic rings, can form a compact and rigid molecular structure, and do not contain benzene rings. Therefore, compared to phenolic epoxy resins, they have good thermal stability, good weather resistance, and excellent electrical insulation. For example, a typical alicyclic epoxy resin, Daicel branched alicyclic epoxy compound EHPE 3150, has a dielectric constant Dk≈3.5, which is lower than that of phenolic epoxy resins. It is the resin used by Taiyo Ink, a Japanese company. Therefore, in order to solve the shortcomings of traditional solder resist ink base resins, such as poor high temperature resistance, poor resistance to tin melting, and poor acid resistance, Japanese patent JP02120308 modified the branched alicyclic epoxy compound EHPE 3150 resin with acrylate bonds and then reacted it with acid anhydride. However, the reaction time between the branched alicyclic epoxy compound EHPE 3150 resin and acrylate is long, and due to steric hindrance, it is difficult for alicyclic epoxy to react completely with acrylic acid, that is, the final acid value is too high, and there are problems with subsequent storage stability. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a method for preparing a branched alicyclic modified acrylate resin. The branched alicyclic modified acrylate resin obtained by the method of this invention contains carboxyl groups in its molecular structure and has a high degree of branching. This branching structure gives the branched alicyclic modified acrylate resin high functionality, resulting in good UV curing speed, high reactivity, high crosslinking, water resistance, acid resistance, heat resistance, and good resistance to tin melting. The carboxyl group structure in the molecular structure of the branched alicyclic modified acrylate resin makes it applicable to alkaline-developable PCB solder resist inks, and it is expected to be used in 5G materials.

[0005] The purpose of this invention is to provide a method for preparing a branched alicyclic modified acrylate resin, comprising the following steps:

[0006] S1. A branched alicyclic epoxy compound, an acrylic compound, a first catalyst, a polymerization inhibitor, and a solvent are mixed and heated to react. The acid value of the reaction system is monitored. If the acid value of the reaction system is less than 2 mg KOH / g, Lewis acid is added and the mixture is purified to obtain a mixed branched alicyclic modified special acrylate.

[0007] S2. The mixed branched alicyclic modified special acrylate is mixed with dianhydride, a second catalyst, a polymerization inhibitor, and a solvent, and the mixture is heated to react, thereby obtaining a branched alicyclic modified special acrylate resin.

[0008] The functional group molar ratio of the branched alicyclic epoxy compound to the acrylic acid compound is 1:0.8~0.9;

[0009] The structure of the branched alicyclic epoxy compound is shown in formula (Ⅰ):

[0010]

[0011] Equation (Ⅰ)

[0012] Where n is 10~15.

[0013] In S1, branched alicyclic epoxy compounds, acrylic compounds, a first catalyst, a polymerization inhibitor, and a solvent are mixed and heated to react. The acid value of the reaction system is monitored. Once the acid value of the reaction system is less than 2 mg KOH / g, the three structures of acrylates in the reaction system are shown below:

[0014] , , After the epoxy groups of branched alicyclic epoxy compounds react with the carboxyl groups of acrylic compounds to achieve an acid value of less than 2 mg KOH / g, Lewis acid catalyzes the reaction between the epoxy groups and hydroxyl groups in the molecular structures of the three types of acrylates. Otherwise, the residual epoxy groups will further react with the hydroxyl and carboxyl groups present in the system during storage, leading to gelation and affecting the storage stability of the product in the later stages; at the same time, it can further improve the crosslinking density of the resin.

[0015] In some embodiments of the present invention, in S1, the epoxy equivalent of the branched alicyclic epoxy compound is 170~200.

[0016] In some embodiments of the present invention, in S1, the structure of the acrylic compound is as shown in formula (II):

[0017]

[0018] Formula (II)

[0019] Where R is H or methyl.

[0020] In some embodiments of the present invention, in S1, the first catalyst includes at least one of triphenylphosphine, tetrabutylammonium bromide, chromium acetate, and antimony trifluoride.

[0021] In some embodiments of the present invention, in S1, the first catalyst includes at least one of triphenylphosphine and tetrabutylammonium bromide.

[0022] In some embodiments of the present invention, in S1, the polymerization inhibitor includes at least one of p-hydroxyanisole, hydroquinone, and phenothiazine.

[0023] In some embodiments of the present invention, in S1, the solvent includes at least one of ethylene glycol butyl ether acetate and butyl acetate.

[0024] In some embodiments of the present invention, in S1, the Lewis acid includes one of boron trifluoride ether, tin tetrachloride, scandium trifluoromethanesulfonate, and ytterbium trifluoromethanesulfonate.

[0025] In some embodiments of the present invention, in S1, the amount of the first catalyst is 3000~8000 ppm of the total mass of the reaction substrate; the reaction substrate is a branched alicyclic epoxy compound and an acrylic compound.

[0026] In some embodiments of the present invention, in S1, the amount of the polymerization inhibitor is 800-1500 ppm of the total mass of the reaction substrate, and the reaction substrate is a branched alicyclic epoxy compound and an acrylic compound.

[0027] In some embodiments of the present invention, in S1, the amount of Lewis acid used is 800-1500 ppm of the total mass of the reaction substrate, and the reaction substrate is a branched alicyclic epoxy compound and an acrylic compound.

[0028] In some embodiments of the present invention, in S1, the temperature of the heating reaction is 90~110°C and the time is 6~12 hours.

[0029] In some embodiments of the present invention, in S2, the dianhydride includes at least one of phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and maleic anhydride.

[0030] In some embodiments of the present invention, in S2, the second catalyst includes at least one of triphenylphosphine, tetrabutylammonium bromide, and dibutyltin oxide.

[0031] In some embodiments of the present invention, in S2, the polymerization inhibitor includes at least one of p-hydroxyanisole, hydroquinone, and phenothiazine.

[0032] In some embodiments of the present invention, in S2, the functional group molar ratio of the mixed branched alicyclic modified special acrylate to the dianhydride is 1:0.5~0.6.

[0033] In some embodiments of the present invention, in S2, the amount of the second catalyst is 1000-2000 ppm of the total mass of the reaction substrate, wherein the reaction substrate is a mixed branched alicyclic modified special acrylate and dianhydride.

[0034] In some embodiments of the present invention, in S2, the amount of the polymerization inhibitor is 800-1500 ppm of the total mass of the reaction substrate, and the reaction substrate is a mixed branched alicyclic modified special acrylate and dianhydride.

[0035] In some embodiments of the present invention, in S2, the temperature of the heating reaction is 90~110°C and the time is 4~6 hours.

[0036] Another objective of this invention is to provide the application of the branched alicyclic modified acrylate resin prepared by the method of preparation of the aforementioned branched alicyclic modified acrylate resin in the preparation of PCB circuit board inks.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] (1) The branched alicyclic modified acrylate resin prepared by the method of the present invention has high TG, low shrinkage, excellent heat resistance and transparency after UV curing. At the same time, the branched alicyclic modified acrylate resin contains acrylate bonds in its molecular structure, which allows it to undergo photoradical polymerization, giving the cured coating higher hardness. In the preparation of PCB ink, the carboxyl groups in the molecular structure of the branched alicyclic modified acrylate resin can undergo thermal polymerization with another epoxy component, further improving the hardness and heat resistance of the cured coating.

[0039] (2) In the preparation of branched alicyclic special modified acrylate resin, the acrylic compound containing carboxyl groups reacts with the branched alicyclic epoxy compound containing epoxy groups. The reaction efficiency is high, and the branched alicyclic special modified acrylate resin with carboxyl groups in the molecular structure has good storage stability.

[0040] (3) Compared with Japanese Patent JP02120308, the molar ratio of the functional groups of branched alicyclic epoxy compound EHPE 3150 and acrylic acid in Japanese Patent JP02120308 is basically 1:1. Moreover, after the reaction between branched alicyclic epoxy compound EHPE 3150 and acrylic acid, no Lewis acid is added to catalyze the reaction between the unreacted epoxy groups and hydroxyl groups. That is, the residual excess epoxy functional groups cannot react with the hydroxyl groups of the generated hydroxyl-containing compound, i.e., no further cross-linking structure is formed. In this technology, the branched alicyclic epoxy compound EHPE The molar ratio of the functional groups of 3150 and acrylic acid is 1:0.80~0.90. The epoxy groups in the branched alicyclic epoxy compounds of the reaction substrate do not react completely. The molecular structure of the mixed ester compounds formed by the reaction of branched alicyclic epoxy compounds and acrylic compounds contains hydroxyl and epoxy groups. The hydroxyl and epoxy groups react under Lewis acid catalysis, increasing the degree of resin crosslinking. At the same time, the excess epoxy groups can increase the effective collision between carboxyl groups and epoxy groups, thereby shortening the reaction time. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0042] The branched alicyclic epoxy compound EHPE 3150 in the examples has an epoxy equivalent of 170~20, i.e., its structure is as shown in formula (Ⅰ):

[0043]

[0044] Equation (Ⅰ)

[0045] Where n is 10~15.

[0046] Example 1

[0047] This embodiment provides a branched alicyclic modified acrylate resin M1, the specific process of which is as follows:

[0048] In a 1.500ml straight four-necked flask, add 128g of ethylene glycol butyl ether acetate solvent and 92.5g of branched alicyclic epoxy compound EHPE 3150 (0.51mol of epoxy groups). Slowly heat to 80℃ to dissolve the branched alicyclic epoxy compound EHPE. After 3150 is completely dissolved, acrylic acid (31.68g, carboxyl group 0.44mol), triphenylphosphine catalyst (0.50g), and phenothiazine (0.10g) polymerization inhibitor are added. The mixture is slowly heated to 90℃, with slight exothermic reaction. After the system stops exothermic, the reaction solution is slowly heated to 105℃±2℃ and kept at this temperature for 4 hours. The acid value is measured when the acid value is less than 2mgKOH / g of the sample. If the acid value is not reached, the reaction continues for 2-4 hours until the acid value meets the standard. Boron trifluoride ether catalyst (0.1g) is added to catalyze the reaction of the remaining epoxy and hydroxyl groups. After the epoxy equivalent (determination standard: GB / T4612-2008) blank is obtained, that is, after the epoxy groups have completely reacted, sodium carbonate or potassium carbonate is added to neutralize the acid. The formed sodium salt and other inorganic substances are removed by filtration to obtain mixed branched alicyclic modified special acrylate.

[0049] S2. The mixed branched alicyclic modified special acrylate (80.35g, 0.33mol hydroxyl groups) and phthalic anhydride (0.30mol) obtained in step S1 were mixed, and triphenylphosphine catalyst (0.20g) was added. The mixture was stirred and slowly heated to 90℃±2℃ and then kept at that temperature for 4 hours. The acid value was measured, and then measured every hour thereafter. After the acid value remained constant, the reaction yielded a carboxyl-containing branched alicyclic modified special acrylate resin M1 with an acid value of 80mgKOH / g (test standard: GB / T 6743-2008), a viscosity of 4000cps at 25℃ (test standard: GB / T 2794-2013), and a solid content of 60% (baked at 110℃).

[0050] Example 2

[0051] This embodiment provides a branched alicyclic modified acrylate resin M2, the specific process of which is as follows:

[0052] In a 1.500ml straight four-necked flask, add 128g of ethylene glycol butyl ether acetate solvent and 92.5g of branched alicyclic epoxy compound EHPE 3150 (0.51mol of epoxy groups). Slowly heat to 80℃ to dissolve the branched alicyclic epoxy compound EHPE. After the 3150 solution is completely dissolved, acrylic acid (31.68g, carboxyl group 0.44mol), triphenylphosphine catalyst (0.50g), and phenothiazine (0.10g) polymerization inhibitor are added. The mixture is slowly heated to 90℃ with slight exothermic reaction. After the system stops exothermic, the reaction solution is slowly heated to 105℃±2℃ and kept at this temperature for 4 hours. The acid value is measured when the acid value is less than 2mgKOH / g of sample. If the acid value is not reached, the reaction continues for 2-4 hours until the acid value meets the standard. Boron trifluoride ether catalyst (0.1g) is added to catalyze the reaction of the remaining epoxy and hydroxyl groups. After the epoxy equivalent (determination standard: GB / T4612-2008) blank is obtained, that is, after the epoxy groups have completely reacted, the acid is neutralized with sodium carbonate / potassium carbonate. The formed sodium salt and other inorganic substances are removed by filtration to obtain mixed branched alicyclic modified special acrylate.

[0053] S2. The mixed branched alicyclic modified special acrylate (80.35g, 0.33mol hydroxyl groups) and succinic anhydride (0.30mol) obtained in step S1 were mixed, and triphenylphosphine catalyst (0.20g) was added. The mixture was slowly heated to 90℃±2℃ and then kept at that temperature for 4 hours. The acid value was measured, and then measured every hour. After the acid value remained constant, the reaction yielded a carboxyl-containing branched alicyclic modified special acrylate resin M2 with an acid value of 85mgKOH / g (test standard: GB / T 6743-2008), a viscosity of 3400cps at 25℃ (test standard: GB / T 2794-2013), and a solid content of 58% (baked at 110℃).

[0054] Example 3

[0055] This embodiment provides a branched alicyclic modified acrylate resin M3, the specific process of which is as follows:

[0056] In a 1.500ml straight four-necked flask, add 128g of ethylene glycol butyl ether acetate solvent and 92.5g of branched alicyclic epoxy compound EHPE 3150 (0.51mol of epoxy groups). Slowly heat to 80℃ to dissolve the branched alicyclic epoxy compound EHPE. After 3150 is completely dissolved, methacrylic acid (37.88g, carboxyl group 0.44mol), triphenylphosphine catalyst (0.50g), and phenothiazine (0.10g) polymerization inhibitor are added. The mixture is slowly heated to 90℃ with slight exothermic reaction. After the system stops exothermic, the reaction solution is slowly heated to 105℃±2℃ and kept at this temperature for 4 hours. The acid value is measured when the acid value is less than 2mgKOH / g of sample. If the acid value is not reached, the reaction continues for 2-4 hours until the acid value meets the standard. Boron trifluoride ether catalyst (0.1g) is added to catalyze the reaction of the remaining epoxy and hydroxyl groups. After the epoxy equivalent (determination standard: GB / T4612-2008) blank is obtained, that is, after the epoxy groups have completely reacted, the acid is neutralized with sodium carbonate / potassium carbonate. The formed sodium salt and other inorganic substances are removed by filtration to obtain mixed branched alicyclic modified special acrylate.

[0057] S2. The mixed branched alicyclic modified special acrylate (84.36 g, 0.33 mol hydroxyl groups) and hexahydrophthalic anhydride (0.30 mol) obtained in step S1 were mixed, and triphenylphosphine catalyst (0.20 g) was added. The mixture was slowly heated to 90℃±2℃ and then kept at that temperature for 4 hours. The acid value was measured, and then measured every hour thereafter. After the acid value remained constant, the reaction yielded a carboxyl-containing branched alicyclic modified special acrylate resin M3 with an acid value of 80 mg KOH / g (test standard: GB / T 6743-2008), a viscosity of 3900 cps at 25℃ (test standard: GB / T 2794-2013), and a solid content of 61% (baked at 110℃).

[0058] Example 4

[0059] This embodiment provides a branched alicyclic modified acrylate resin M4, the specific process of which is as follows:

[0060] In a 500ml straight four-necked flask, add 128g of ethylene glycol butyl ether acetate solvent and 92.5g of branched alicyclic epoxy compound EHPE 3150 (0.51mol of epoxy groups). Slowly heat to 80℃ to dissolve the branched alicyclic epoxy compound EHPE. After 3150 is completely dissolved, methacrylic acid (37.88g, carboxyl group 0.44mol), triphenylphosphine catalyst (0.50g), and phenothiazine (0.10g) polymerization inhibitor are added. The mixture is slowly heated to 90℃ with slight exothermic reaction. After the system stops exothermic, the reaction solution is slowly heated to 105℃±2℃ and kept at this temperature for 4 hours. The acid value is measured when the acid value is less than 2mgKOH / g of sample. If the acid value is not reached, the reaction continues for 2-4 hours until the acid value meets the standard. Boron trifluoride ether catalyst (0.1g) is added to catalyze the reaction of the remaining epoxy and hydroxyl groups. After the epoxy equivalent (determination standard: GB / T4612-2008) blank is obtained, that is, after the epoxy groups have completely reacted, the acid is neutralized with sodium carbonate / potassium carbonate. The formed sodium salt and other inorganic substances are removed by filtration to obtain mixed branched alicyclic modified special acrylate.

[0061] S2. The mixed alicyclic modified special acrylate (84.36 g, 0.33 mol hydroxyl groups) and maleic anhydride (0.30 mol) prepared in step S1 were subjected to a hydroxyl-to-anhydride reaction. Triphenylphosphine catalyst (0.20 g) was added, and the temperature was slowly raised to 90℃±2℃ and held for 4 hours. The acid value was measured, and then measured every hour. After the acid value remained constant, the reaction yielded a carboxyl-containing branched alicyclic special modified acrylate resin M4 with an acid value of 85 mg KOH / g (test standard: GB / T 6743-2008), a viscosity of 3300 cps at 25℃ (test standard: GB / T 2794-2013), and a solid content of 59% (baked at 110℃).

[0062] Comparative Example 1

[0063] This comparative example provides an alicyclic modified acrylate resin M5, and the specific process is as follows:

[0064] In a 1.500ml straight four-necked flask, add 128g of ethylene glycol butyl ether acetate solvent and 92.5g of branched alicyclic epoxy compound EHPE 3150 (0.51mol of epoxy groups). Slowly heat to 80℃ to dissolve the branched alicyclic epoxy compound EHPE 3150. After it is completely dissolved, add 36.72g of acrylic acid (0.51mol of carboxyl groups), 0.52g of triphenylphosphine catalyst, and 0.10g of phenothiazine polymerization inhibitor. Slowly raise the temperature to 90℃. There is slight exothermic reaction. After the system stops exothermic, slowly raise the temperature of the reaction solution to 105℃±2℃ and hold for 4 hours. Then take a sample to measure the acid value. Hold the reaction for 30 hours. The acid value is 5mgKOH / g. This step of the reaction is completed, and the alicyclic modified special acrylate compound is obtained.

[0065] S2. The alicyclic modified special acrylate compound (83.61 g, 0.33 mol hydroxyl group) obtained in step S1 and phthalic anhydride (45.23 g, 0.30 mol) were mixed, and triphenylphosphine catalyst (0.20 g) was added. The mixture was slowly heated to 90℃±2 and then kept at that temperature for 20 hours. The reaction yielded a carboxyl-containing alicyclic special modified acrylate resin M5 with a viscosity of 4500 cps at 25℃ (test standard: GB / T 2794-2013) and a solid content of 62% (baked at 110℃).

[0066] Comparative Example 2

[0067] This comparative example provides a branched alicyclic modified acrylic resin M6, the specific process of which is as follows:

[0068] The only difference from Comparative Example 1 is that the amount of acrylic acid added was replaced from 0.51 mol to 0.44 mol; the reaction time in step S1 was 6 hours, the acid value was 1.68 mg KOH / g, and after the reaction was completed, alicyclic special modified acrylic resin M6 was obtained, with a viscosity of 3500 cps at 25℃ (test standard: GB / T 2794-2013) and a solid content of 55% (baked at 110℃).

[0069] Performance testing:

[0070] Resins M1 to M6 from Examples 1-4 and Comparative Examples 1-2 were placed in sealed iron cans and aged at 80°C for 7 days. The viscosity of the products before and after aging was compared. The viscosity change was no more than 10%, which means that the product aging performance was qualified and the product was stable. The test results are shown in Table 1.

[0071] Table 1. Performance tests of resins M1 to M6.

[0072]

[0073] As shown in Table 1, the branched alicyclic modified acrylate resins M1-M4 in Examples 1-4 maintained essentially unchanged viscosity and were stable after aging in an iron can at 80°C for 7 days. In contrast, the alicyclic modified acrylate resins M5 and M6 in Comparative Examples 1-2 gelled after aging in an iron can for 7 days. This phenomenon indicates that the process used in this invention patent has a significant effect on preparing stable carboxyl-containing branched alicyclic modified acrylate resins and can effectively achieve industrial-scale production. In addition, the reaction time of step S1 in this invention patent is about 6 hours because the feed ratio of branched alicyclic epoxy compound EHPE 3150 to acrylic acid functional group is 1 mol: 0.9 mol, with an excess of epoxy groups. The carboxyl groups can be quickly consumed by the epoxy groups. However, when the feed ratio of branched alicyclic epoxy compound EHPE 3150 to acrylic acid functional group is 1 mol: 1 mol, it is difficult for the carboxyl groups to be completely consumed by the epoxy groups. Therefore, the method of using an excess of epoxy groups in branched alicyclic epoxy compound EHPE 3150 in this invention patent can effectively accelerate the reaction efficiency of the first step.

[0074] Example 5

[0075] This embodiment provides a coating, the specific process of which is as follows:

[0076] 80g of branched alicyclic modified acrylate resin M1, 20g of 1,6-hexanediol diacrylate HDDA, and 3g of photoinitiator 1173 were mixed thoroughly and coated onto a PC board using a 12μm wire rod. The board was then cured by irradiation with a medium-pressure mercury lamp for 10 seconds at a light intensity of 200 mJ·cm². -2 Once the coating has fully cured, the coating is obtained.

[0077] Examples 6-8, Comparative Example 3

[0078] The branched alicyclic modified acrylate resin M1 in Example 5 was replaced with branched alicyclic modified acrylate resins M2 to M4 to obtain the coatings of Examples 6 to 8; the resin M1 was replaced with branched alicyclic modified acrylate resin M5 to obtain the coating of Comparative Example 3.

[0079] Acid resistance testing of branched alicyclic modified acrylate resins M1~M4 in UV-cured formulations: The acid resistance of the resins was determined by immersion method, in which the cured coated plates were completely immersed in 0.05mol / L sulfuric acid solution at 20℃ for 30 minutes. The coating was observed for any loss of gloss, discoloration, blistering, spots, or peeling. If none of these occurred, the coating was considered intact and marked OK. If any changes such as loss of gloss, discoloration, blistering, spots, or peeling were observed, the coating was considered damaged and marked NG. In other words, OK indicates good acid resistance, meaning the resin has good acid resistance. Simultaneously, the gloss change before and after immersion was measured using a WGG60-E4 single-angle 60-degree gloss meter (Quanzhou Keshijia Optoelectronic Instrument Research Institute). Gloss testing was conducted according to ASTM-D 523. Adhesion testing before and after immersion was performed using the cross-cut adhesion test method, according to GB / T9286 and ISO 2409 standards. Take an appropriate amount of the light-cured coating and use differential scanning calorimetry (DSC) to test the glass transition temperature Tg of the cured polymer (GB / T 19466.2-2004).

[0080] Table 2. Coating performance test results of Examples 5-8 and Comparative Example 3.

[0081]

[0082] Table 2 shows that the photocurable coatings prepared from branched alicyclic modified acrylate resins M1-M4 remained intact after immersion in sulfuric acid solution at 20°C; and the gloss and adhesion properties did not change before and after immersion, indicating that the synthesized branched alicyclic modified acrylate resins M1-M4 have good acid resistance. The glass transition temperature (Tg) of the branched photocurable coatings prepared from branched alicyclic modified acrylate resins M1-M4 is more than 10°C higher than that of the polymer coatings prepared from resin M5 (epoxy:carboxyl = 1:1 in the first step, which cannot undergo crosslinking reaction). This indicates that the use of excess epoxy for further self-polymerization in this invention further increases the crosslinking density and hardness of the resin, which can further improve the relevant properties when applied to PCB solder resist inks.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.

Claims

1. A method for preparing a branched alicyclic modified acrylate resin, characterized in that, Includes the following steps: S1. A branched alicyclic epoxy compound, an acrylic compound, a first catalyst, a polymerization inhibitor, and a solvent are mixed and heated to react. The acid value of the reaction system is monitored. If the acid value of the reaction system is less than 2 mg KOH / g, Lewis acid is added and the mixture is purified to obtain a mixed branched alicyclic modified special acrylate. S2. The mixed branched alicyclic modified special acrylate is mixed with dianhydride, a second catalyst, a polymerization inhibitor, and a solvent, and the mixture is heated to react, thereby obtaining a branched alicyclic modified special acrylate resin. The functional group molar ratio of the branched alicyclic epoxy compound to the acrylic acid compound is 1:0.8~0.9; The structure of the branched alicyclic epoxy compound is shown in formula (Ⅰ): Equation (Ⅰ) Where n is 10~15; The structure of the acrylic compound is shown in formula (II): Formula (II) Where R is H or methyl.

2. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S1, the epoxy equivalent of the branched alicyclic epoxy compound is 170~200.

3. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S1, the first catalyst includes at least one of triphenylphosphine, tetrabutylammonium bromide, chromium acetate, and antimony trifluoride; The polymerization inhibitor includes at least one of p-hydroxyanisole, hydroquinone, and phenothiazine. The solvent includes at least one of ethylene glycol butyl ether acetate and butyl acetate; The Lewis acid includes one of boron trifluoride ether, tin tetrachloride, scandium trifluoromethanesulfonate, and ytterbium trifluoromethanesulfonate.

4. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S1, the amount of the first catalyst is 3000~8000 ppm of the total mass of the reaction substrate; The amount of the polymerization inhibitor is 800-1500 ppm of the total mass of the reaction substrate; The amount of Lewis acid used is 800-1500 ppm of the total mass of the reaction substrate.

5. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S1, the temperature of the heating reaction is 90~110℃ and the time is 6~12 hours.

6. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S2, the dianhydride includes at least one of phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and maleic anhydride; The second catalyst includes at least one of triphenylphosphine, tetrabutylammonium bromide, and dibutyltin oxide; The polymerization inhibitor includes at least one of p-hydroxyanisole, hydroquinone, and phenothiazine.

7. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S2, the functional group molar ratio of the mixed branched alicyclic modified special acrylate to the dianhydride is 1:0.5~0.

6.

8. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S2, the amount of the second catalyst is 1000~2000 ppm of the total mass of the reaction substrate; The amount of the polymerization inhibitor is 800-1500 ppm of the total mass of the reaction substrate.

9. The method for preparing the branched alicyclic special modified acrylate resin as described in claim 1, characterized in that, In S2, the temperature of the heating reaction is 90~110℃ and the time is 4~6 hours.

10. The application of the branched alicyclic special modified acrylate resin prepared by the method of any one of claims 1 to 9 in the preparation of PCB circuit board inks.

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