An eight-functional light-cured resin and a method for preparing the same

Abstract

The application discloses a preparation method of a novel eight-functional photo-curable resin, which comprises the following steps: firstly, selecting oxalyl chloride and malic acid to obtain an intermediate with four terminal carboxyl groups through a certain reaction temperature and reaction time; then, reacting the intermediate with trimethylolpropane to obtain a two-step intermediate with eight terminal hydroxyl groups; and finally, reacting the two-step intermediate with acrylic acid and epoxy resin 828 under certain reaction conditions to obtain a final reaction product. Through a large number of experiments, the best raw material composition and ratio are screened, and a novel eight-functional photo-curable resin with scientific and reasonable component ratio, good stability and excellent comprehensive performance is obtained.

Description

Technical Field

[0001] This invention relates to an oligomer for photosensitive coatings, specifically to an eight-functional photocurable resin and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] UV curing, a material surface treatment technology that emerged in the 1960s, utilizes ultraviolet light to initiate the rapid polymerization and cross-linking of chemically active liquid materials, instantly curing them into solid materials with specific properties. This technology has consistently been characterized by high efficiency, energy saving, and high quality. Common UV-curable resins mainly include: unsaturated polyester acrylates, epoxy acrylates, polyurethane acrylates, polyester acrylates, polyether acrylates, pure acrylate resins, oligomers, and waterborne UV-curable resins. In recent years, with the increasing awareness of energy conservation and environmental protection, the variety and performance of UV-curable coatings have been continuously enhanced, their application fields have been expanded, and their production volume has been increasing. Currently, in addition to applications in traditional industries, UV-curable systems have gradually extended to high-end fields such as optical fibers, printed circuit boards, and electronic component packaging. Market competition has also increased significantly, leading more and more UV-curable coating companies to simplify coating formulations to maximize the quality of the final product. Given this situation, developing a UV-curable resin with good stability and excellent overall performance has become a trend. Summary of the Invention

[0003] Objective of this invention: To address the shortcomings of existing technologies, this invention, through extensive experimental screening, selects terephthaloyl chloride and citric acid and reacts them at specific temperatures and times to obtain an intermediate with six terminal carboxyl groups. This intermediate is then reacted with glycerol to yield a two-step intermediate with twelve terminal hydroxyl groups. Finally, this two-step intermediate is reacted with acrylic acid and trimethylolethane polyglycidyl ether under specific reaction conditions to obtain the final product. This invention can be widely used in various systems requiring high stability and excellent overall performance, overcoming the deficiencies of existing technologies.

[0004] Another object of the present invention is to provide a method for preparing the eight-eight-element light-curable resin and its basic application properties.

[0005] Technical Solution: To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0006] A method for preparing a photosensitive eight-functional photocurable resin includes the following steps:

[0007] (1) First, oxalyl chloride and malic acid were reacted under certain reaction conditions to prepare an intermediate I with four terminal carboxyl groups;

[0008] (2) Then, intermediate I was reacted with trimethylolpropane under certain conditions to obtain a two-step intermediate II with eight terminal hydroxyl groups;

[0009] (3) Intermediate II is reacted with 20-40 parts by weight of acrylic acid and 0.5-3 parts by weight of epoxy resin 828 under certain reaction conditions to obtain an eight-function light-cured resin.

[0010] As a preferred embodiment, the preparation method of the photosensitive eight-functional photocurable resin described above includes the following steps:

[0011] (1) First, select 5-15 parts by mass of oxaloyl chloride and 10-30 parts by mass of malic acid and prepare an intermediate I with four terminal carboxyl groups under certain reaction conditions.

[0012] (2) Then, the intermediate I is reacted with 20-40 parts by mass of trimethylolpropane under certain conditions to obtain a two-step intermediate II with eight terminal hydroxyl groups;

[0013] (3) Intermediate II is reacted with 20-40 parts by weight of acrylic acid and 0.5-3 parts by weight of epoxy resin 828 under certain reaction conditions to obtain an eight-function light-cured resin.

[0014] As a preferred embodiment, the preparation method of the photosensitive octagonal photocurable resin described above, the specific steps of step (1) are as follows: oxalyl chloride is dissolved in 8 parts by mass of toluene, and slowly added dropwise to 8 parts by mass of toluene in which malic acid has been dissolved. While adding dropwise, a micro vacuum of -0.001 to -0.01 MPa is used to remove the acid mist generated by the reaction. The dropwise addition time is 1 to 5 hours. After the dropwise addition is completed, the reaction is continued under vacuum. The reaction temperature is controlled between -10℃ and 10℃. The reaction time is 5 to 8 hours. After the reaction is completed, the temperature is lowered to obtain an intermediate I with four terminal carboxyl groups.

[0015] As a preferred embodiment, the preparation method of the photosensitive octagonal photocurable resin described above, the specific steps of step (2) are as follows: add trimethylolpropane to intermediate I, then add 0-0.5 parts by weight of antioxidant hypophosphite and 0-0.5 parts by weight of catalyst p-toluenesulfonic acid, control the reaction time to 3 to 8 hours, the reaction temperature to 100℃ to 140℃, and when the acid value is lower than 3mgKOH / g, cool down to end the reaction to obtain intermediate II;

[0016] As a preferred embodiment, the preparation method of the photosensitive octagonal photocurable resin described above, the specific steps of step (3) are as follows: add acrylic acid to intermediate II, then add 0-0.5 parts by weight of antioxidant hypophosphite, 0-0.5 parts by weight of polymerization inhibitor hydroquinone and 0-1 parts by weight of catalyst p-toluenesulfonic acid, control the reaction time to 5 to 10 hours, the reaction temperature to 90°C to 130°C, when the acid value is lower than 10 mg KOH / g, cool down to below 80°C and add epoxy resin 828 and 0-1 parts by weight of catalyst triphenylphosphine, control the reaction time to 1-3 hours, the reaction temperature to 90-130°C, after the reaction is completed, turn on the vacuum to -0.1 MPa, desolvent for 1 to 3 hours, and obtain the octagonal photocurable resin.

[0017] The epoxy resin 828 used in this invention is SM828 produced by Jiangsu Sanmu Chemical Co., Ltd., or EPON828 produced by Hexion.

[0018] The key to this approach lies in the need for a strictly controlled vacuum environment during the synthesis of intermediate I. By controlling the vacuum environment, it is possible to prevent the solvent from being removed in large quantities while simultaneously removing the hydrochloric acid mist generated during the forward reaction. With optimal reactant ratios, reaction temperatures, and reaction times, an intermediate I with a defined structure can be obtained. Subsequent reactions can then be successfully synthesized by controlling the optimal reactant ratios, reaction temperatures, and reaction times to synthesize an octagonal photocurable resin containing eight active terminal groups.

[0019] Beneficial Effects: Through extensive experimental screening, this invention selects terephthaloyl chloride and citric acid, and obtains an intermediate I with six terminal carboxyl groups by optimizing the vacuum degree, reaction temperature, and reaction time. Then, intermediate I is reacted with glycerol to obtain a two-step intermediate II with twelve terminal hydroxyl groups. Finally, intermediate II is reacted with acrylic acid and trimethylolethane polyglycidyl ether under specific reaction conditions to obtain the final reaction product. Experimental results show that this invention possesses comprehensive properties such as good stability, low viscosity, fast curing speed, good hardness, and good flexibility, overcoming the shortcomings of existing technologies. Attached Figure Description

[0020] Figure 1 This is a flowchart of the synthesis process of the present invention. Detailed Implementation

[0021] Example 1

[0022] A method for preparing a photosensitive eight-functional photocurable resin includes the following steps:

[0023] (1) 6.9 parts by mass of oxaloyl chloride were dissolved in 8 parts by mass of toluene and slowly added dropwise to 8 parts by mass of toluene containing 14.5 parts by mass of malic acid. During the dropwise addition, a micro-vacuum of -0.008 MPa was used to remove the acid fumes generated during the reaction. The dropwise addition took 3 hours. After the dropwise addition was completed, the reaction continued under vacuum, with the reaction temperature controlled at -10°C, for a reaction time of 7 hours. After the reaction was completed, intermediate I was obtained. The reaction yield was approximately 98%. Intermediate I was then subjected to… 1 H-NMR analysis revealed that the peak area ratio between the chemical shift at 11.0 of the terminal carboxyl group and the chemical shift at 5.16 of the tertiary carbon atom on the malic acid in the structure was approximately 2:1. At the same time, the chemical shift near 2.0, which represents the hydroxyl group, disappeared, indicating that the structure had been successfully synthesized.

[0024]

[0025] (2) The intermediate I product from step (1) was mixed thoroughly with 29.5 parts by weight of trimethylolpropane, and then 0.1 parts by weight of the antioxidant hypophosphite and 0.3 parts by weight of the catalyst p-toluenesulfonic acid were added. The reaction time was controlled at 7 hours and the reaction temperature at 130°C. When the acid value was lower than 3 mg KOH / g, the reaction was stopped by cooling to obtain intermediate II. The reaction yield was approximately 93%. The intermediate II... 1 H-NMR showed that the ratio of the chemical shift peak area around 2.0 on the terminal hydroxyl group to the chemical shift peak area around 5.4 on the hydrogen atom of the tertiary carbon atom in malic acid was approximately 4:1, indicating that intermediate II had been successfully synthesized.

[0026]

[0027] (3) Mix the intermediate II product from step (2) with 30.6 parts by mass of acrylic acid, then add 0.1 parts by mass of antioxidant hypophosphite, 0.1 parts by mass of polymerization inhibitor hydroquinone and 0.4 parts by mass of catalyst p-toluenesulfonic acid. Control the reaction time to 9 hours and the reaction temperature to 120°C. When the acid value is lower than 10 mg KOH / g, cool down to below 80°C and add 1 part by mass of epoxy resin 828 and 0.5 parts by mass of catalyst benzyltriethylammonium chloride. Control the reaction time to 1.5 hours and the reaction temperature to 110°C. After the reaction is completed, turn on the vacuum to -0.1 MPa and desolvate for 2.5 hours to obtain the final product, an eight-element light-cured resin with a reaction yield of about 91%.

[0028]

[0029] Example 2

[0030] A method for preparing a photosensitive eight-functional photocurable resin includes the following steps:

[0031] (1) 5.9 parts by mass of oxaloyl chloride were dissolved in 8 parts by mass of toluene and slowly added dropwise to 8 parts by mass of toluene containing 14.5 parts by mass of malic acid. During the dropwise addition, a micro-vacuum of -0.008 MPa was used to remove the acid mist generated during the reaction. The dropwise addition took 2 hours. After the dropwise addition was completed, the reaction continued under vacuum, with the reaction temperature controlled at -5°C and the reaction time at 6 hours. After the reaction was completed, intermediate I was obtained, with a yield of approximately 62%. The intermediate I... 1 ¹H-NMR analysis showed that the peak area ratio between the chemical shift at the terminal carboxyl group at 11.0 and the chemical shift at 5.16 on the tertiary carbon of the malic acid atom was much less than 2:1. Furthermore, the chemical shift near 2.0, representing the hydroxyl group, did not completely disappear, indicating that intermediate I was not fully synthesized. This suggests that variations in reactant amounts, reaction temperature, and time affected the yield of intermediate I in this step.

[0032] (2) The product of intermediate I from step (1) was mixed evenly with 31 parts by mass of trimethylolpropane, and then 0.1 parts by mass of the antioxidant hypophosphite and 0.3 parts by mass of the catalyst p-toluenesulfonic acid were added. The reaction time was controlled at 6 hours and the reaction temperature at 150°C. When the acid value was lower than 3 mg KOH / g, the reaction was stopped by cooling to obtain intermediate II. The reaction yield was about 46%. Due to the unsuitable reaction temperature for the two-step reaction and the low yield of intermediate I in step (1), the yield of intermediate II was low. 1 H-NMR showed that the ratio of the chemical shift peak area around 2.0 on the terminal hydroxyl group to the chemical shift peak area around 5.4 on the tertiary carbon atom of malic acid was less than 4:1. Based on this, it is inferred that a large number of three-dimensional branched structures were formed in the resin.

[0033] (3) The intermediate II reaction product from step (2) was mixed evenly with 30.1 parts by mass of acrylic acid, and then 0.1 parts by mass of antioxidant hypophosphite, 0.1 parts by mass of polymerization inhibitor hydroquinone, and 0.4 parts by mass of catalyst p-toluenesulfonic acid were added. The reaction time was controlled at 7 hours and the reaction temperature at 130°C. When the acid value was lower than 10 mg KOH / g, the temperature was lowered to below 80°C and 1 part by mass of epoxy resin 828 and 0.5 parts by mass of catalyst benzyltriethylammonium chloride were added. The reaction time was controlled at 1 hour and the reaction temperature at 120°C. After the reaction was completed, a vacuum of -0.1 MPa was turned on and solvent was removed for 2 hours to obtain the final product, an eight-element light-cured resin. Based on the acid value, the yield was roughly estimated to be about 44%.

[0034] Example 3

[0035] A method for preparing a photosensitive eight-functional photocurable resin includes the following steps:

[0036] (1) 6.9 parts by mass of oxaloyl chloride were dissolved in 8 parts by mass of toluene and slowly added dropwise to 8 parts by mass of toluene containing 14.5 parts by mass of malic acid. During the dropwise addition, a micro-vacuum of -0.005 MPa was used to remove the acid fumes generated during the reaction. The dropwise addition took 3 hours. After the dropwise addition was completed, the reaction continued under vacuum, with the reaction temperature controlled at -10°C for 7 hours. After the reaction was completed, intermediate I was obtained. The reaction yield was approximately 83%. Intermediate I was then subjected to… 1 ¹H-NMR analysis revealed that the chemical shift near 2.0, representing the hydroxyl group, did not completely disappear, indicating that some malic acid was not fully attached to the structure, suggesting that the vacuum level in this step has a significant impact on the reaction.

[0037] (2) The intermediate I product synthesized in step (1) was mixed evenly with 29.5 parts by mass of trimethylolpropane, and then 0.1 parts by mass of the antioxidant hypophosphite and 0.3 parts by mass of the catalyst p-toluenesulfonic acid were added. The reaction time was controlled at 7 hours and the reaction temperature was 130℃. When the acid value was lower than 3 mg KOH / g, the reaction was stopped by cooling to obtain intermediate II. The reaction yield was about 76%. Due to the low yield of intermediate I product in step (1), the reaction yield of intermediate II in step (2) was also low.

[0038] (3) The intermediate II reaction product from step (2) was mixed evenly with 30.6 parts by mass of acrylic acid, and then 0.1 parts by mass of antioxidant hypophosphite, 0.1 parts by mass of polymerization inhibitor hydroquinone, and 0.4 parts by mass of catalyst p-toluenesulfonic acid were added. The reaction time was controlled at 9 hours and the reaction temperature at 120°C. When the acid value was lower than 10 mg KOH / g, the temperature was lowered to below 80°C and 1 part by mass of epoxy resin 828 and 0.5 parts by mass of catalyst benzyltriethylammonium chloride were added. The reaction time was controlled at 1.5 hours and the reaction temperature at 110°C. After the reaction was completed, a vacuum of -0.1 MPa was turned on and the solvent was removed for 2.5 hours to obtain the final product, an eight-element light-cured resin, with a yield of about 75%. Due to the low yield of intermediate II product in step (2), the reaction yield of the final product in step (3) was also low.

[0039] Example 4 Performance Test

[0040] The performance of the reaction product containing the photosensitive eight-functional photocurable resin obtained in Example 1 above was measured, and the specific experimental results are shown in Table 1 below.

[0041] Table 1 Performance Test Results

[0042]

[0043] Note: The curing speeds in the table are based on a UV curing machine at 80mW / cm². 2The results were obtained from light intensity curing tests. Hardness and gloss tests were performed in accordance with GB / T13448-2006 standard, while flexibility tests were performed in accordance with GB / T1731 standard.

[0044] The experimental results above show that the eight-eight-element photocurable resin prepared in Example 1 of the present invention has the characteristics of good stability, excellent comprehensive properties such as hardness and flexibility.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a photosensitive eight-functional photocurable resin, characterized in that, Includes the following steps: Step (1): Dissolve oxalyl chloride in 8 parts by mass of toluene, and slowly add it dropwise to 8 parts by mass of toluene in which malic acid has been dissolved. While adding the solution, use a micro vacuum of -0.001 to -0.01 MPa to remove the acid mist generated during the reaction. The addition time is 1 to 5 hours. After the addition is completed, continue the reaction under vacuum, control the reaction temperature between -10℃ and 10℃, and the reaction time is 5 to 8 hours. After the reaction is completed, cool down to obtain an intermediate I with four terminal carboxyl groups. Intermediate I; Step (2): Add trimethylolethane to intermediate I, then add 0.1-0.5 parts by weight of antioxidant hypophosphite and 0.3-0.5 parts by weight of catalyst p-toluenesulfonic acid. Control the reaction time to 3 to 8 hours and the reaction temperature to 100℃ to 140℃. When the acid value is lower than 3mgKOH / g, cool down to end the reaction and obtain intermediate II. Intermediate II; Step (3): Add acrylic acid to intermediate II, then add 0.1-0.5 parts by weight of antioxidant hypophosphite, 0.1-0.5 parts by weight of polymerization inhibitor hydroquinone and 0.4-1 parts by weight of catalyst p-toluenesulfonic acid. Control the reaction time to 5 to 10 hours and the reaction temperature to 90℃ to 130℃. When the acid value is lower than 10mgKOH / g, cool down to below 80℃, add epoxy resin 828 and 0.5-1 parts by weight of catalyst benzyltriethylammonium chloride, control the reaction time to 1-3 hours and the reaction temperature to 90-130℃. After the reaction is completed, turn on the vacuum to -0.1MPa and desolvate for 1 to 3 hours to obtain photosensitive eight-sensory light-curing resin. The reaction formula is as follows: 。 2. The method for preparing a photosensitive eight-functional photocurable resin according to claim 1, characterized in that, Includes the following steps: (1) Dissolve 6.9 parts by mass of oxalyl chloride in 8 parts by mass of toluene and slowly add it dropwise to 8 parts by mass of toluene in which 14.5 parts by mass of malic acid is dissolved. While adding the solution, use a micro vacuum of -0.008 MPa to remove the acid mist generated during the reaction. The addition time is 3 hours. After the addition is completed, continue the reaction under vacuum. Control the reaction temperature at -10℃ and the reaction time is 7 hours. After the reaction is completed, intermediate I is obtained. (2) Mix the intermediate I product from step (1) with 29.5 parts by mass of trimethylolethane, then add 0.1 parts by mass of antioxidant hypophosphite and 0.3 parts by mass of catalyst p-toluenesulfonic acid. Control the reaction time to 7 hours and the reaction temperature to 130°C. When the acid value is lower than 3 mg KOH / g, cool down to end the reaction and obtain intermediate II. (3) Mix intermediate II from step (2) with 30.6 parts by mass of acrylic acid evenly, then add 0.1 parts by mass of antioxidant hypophosphite, 0.1 parts by mass of polymerization inhibitor hydroquinone and 0.4 parts by mass of catalyst p-toluenesulfonic acid. Control the reaction time to 9 hours and the reaction temperature to 120°C. When the acid value is lower than 10 mg KOH / g, cool down to below 80°C, add 1 part by mass of epoxy resin 828 and 0.5 parts by mass of catalyst benzyltriethylammonium chloride, control the reaction time to 1.5 hours and the reaction temperature to 110°C. After the reaction is completed, turn on the vacuum to -0.1 MPa and desolvate for 2.5 hours to obtain photosensitive eight-sensory light-curing resin.

3. The application of the photosensitive octagonal photocurable resin prepared by the method of claim 1 or 2 in the preparation of oligomers for photosensitive coatings.

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