Alkali-soluble alicyclic copolyether resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to alkali-soluble alicyclic copolyether resin as well as a preparation method and application thereof. According to the alkali-soluble alicyclic copolyether resin provided by the invention, firstly, 3, 4-epoxy cyclohexyl methacrylate and tetrahydrofuran are used for preparing an alicyclic copolyether intermediate, and then the alicyclic copolyether intermediate and 3-mercaptopropionic acid are subjected to ultraviolet light click reaction to prepare the alkali-soluble alicyclic copolyether. The alkali-soluble alicyclic copolyether resin prepared through ring-opening polymerization not only retains the own ring structure of 3, 4-epoxy cyclohexyl methacrylate and improves the rigidity of the resin, but also has a tetrahydrofuran flexible chain segment, and the alkali-soluble alicyclic copolyether resin is endowed with alkali developing activity by adopting an ultraviolet light click reaction. The preparation process does not need high temperature and high pressure, the process is simple and convenient, reaction conditions are mild, and the method is suitable for large-scale production and high in practical application value.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and specifically relates to an alkali-soluble alicyclic copolyether resin and a preparation method and application thereof. Background Art

[0002] With the continuous development of optoelectronic technology, display technology and the electronics manufacturing industry, photosensitive resins are increasingly used in the fields of optical display, electronic components, flexible displays and integrated circuit manufacturing. As a key material in processes such as photolithography, image transfer and protective coating, photosensitive resins are required to have good flexibility, thermal stability and UV curing properties. However, existing photosensitive resins often have trade-offs between these properties and are difficult to fully meet high performance requirements. Although existing resins can meet the requirements of a certain performance, they often compromise in other aspects, especially in the balance between thermal stability, flexibility and photocuring performance, and there are still technical bottlenecks.

[0003] Although alicyclic epoxy monomers have excellent thermal stability and photocuring properties, and can improve the curing effect and heat resistance of traditional resins, how to improve the overall performance of the resin on this basis, especially to maintain good mechanical properties (such as the balance between flexibility and rigidity), is still a technical problem. Especially in modern electronic manufacturing, the requirements for the flexibility and thermal stability of resins are getting higher and higher. How to break through the limitations of existing materials and develop resins that have both excellent curing properties and high mechanical properties has become the focus of current research.

[0004] As an ideal resin material, polyether resin has been widely used in many fields due to its low viscosity, good flexibility, low cost and other advantages. However, the thermal stability and photocuring performance of traditional polyether resins often cannot meet higher application requirements. Therefore, the development of polyether resins with improved molecular structures can expand their application potential in the modern electronics industry while meeting multiple performance requirements. Summary of the invention

[0005] The object of the present invention is to provide an alkali-soluble polyurethane acrylate resin and a preparation method and application thereof, so as to solve at least one of the above-mentioned technical problems.

[0006] According to one aspect of the present invention, there is provided an alkali-soluble polyurethane acrylate resin, the structural formula of which is as follows:

[0007]

[0008] Wherein, a, b, and c represent mass fractions respectively, and satisfy a+b+c=1, 0.23≤a≤0.27, 0.365≤b≤0.385, and 0.365≤c≤0.385.

[0009] According to another aspect of the present invention, there is provided a method for preparing the above-mentioned alkali-soluble polyurethane acrylate resin, comprising the following steps:

[0010] S1. Evenly mix the solvent, polyol, tetrahydrofuran and catalyst, add 3,4-epoxycyclohexyl methacrylate dropwise at 0-5°C, then heat to 15-25°C, react for 4-6h, add water to terminate the reaction, and then remove the solvent to obtain an alicyclic copolyether intermediate;

[0011] S2. Evenly mix the alicyclic copolyether intermediate prepared in S1 with 3-mercaptopropionic acid, an organic solvent and a photoinitiator, react under ultraviolet light for 10-30 minutes, and then remove the solvent to obtain an alkali-soluble alicyclic copolyether.

[0012] The preparation method of the alkali-soluble polyurethane acrylate resin provided by the present invention comprises the following steps: firstly preparing an alicyclic copolyether intermediate with 3,4-epoxycyclohexyl methacrylate and tetrahydrofuran, and then subjecting the alicyclic copolyether intermediate to an ultraviolet click reaction with 3-mercaptopropionic acid to prepare an alkali-soluble alicyclic copolyether. Specifically, the catalyst boron trifluoride ethyl ether generates protons with a polyol initiator to initiate the ring-opening cationic polymerization of the epoxy groups of tetrahydrofuran and 3,4-epoxycyclohexyl methacrylate to generate an alicyclic copolyether intermediate; then, 3-mercaptopropionic acid and a photoinitiator generate thiol free radicals under the action of ultraviolet light, attacking the unsaturated carbon-carbon double bonds in the alicyclic copolyether intermediate for grafting, and obtaining a thiol-ene product, i.e., an alkali-soluble alicyclic copolyether.

[0013] In some embodiments, the alicyclic copolyether intermediate in step S1 has the following structural formula:

[0014]

[0015] Wherein, a and b represent mass fractions respectively, and satisfy a+b=1, 0.24≤a≤0.26, 0.74≤b≤0.76.

[0016] In some embodiments, the molar ratio of 3,4-epoxycyclohexyl methacrylate to tetrahydrofuran in step S1 is (2-5):1.

[0017] In some embodiments, the solvent in step S1 is one or more of acetone, dichloromethane, butanone, and toluene, and the amount used is 1-3 times the total mass of 3,4-epoxycyclohexyl methacrylate and tetrahydrofuran.

[0018] In some embodiments, the catalyst in step S1 is boron trifluoride ethyl ether, and the amount used is 0.5-3 wt % of the total mass of 3,4-epoxycyclohexyl methacrylate and tetrahydrofuran.

[0019] In some embodiments, the polyol in step S1 is one or more of ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolpropane and trimethylolethane, and the amount thereof is 0.5-2 wt % of the total mass of 3,4-epoxycyclohexyl methacrylate and tetrahydrofuran.

[0020] In some embodiments, the molar ratio of the double bonds in the alicyclic copolyether intermediate to the thiol groups of 3-mercaptopropionic acid in step S2 is 1:(0.4-0.6).

[0021] In some embodiments, the organic solvent in step S2 is at least one of acetone, dichloromethane, butanone, and toluene, and its amount is 1-3 times the total mass of the alicyclic copolyether intermediate and 3-mercaptopropionic acid. Preferably, the organic solvent in step S2 is dichloromethane.

[0022] In some embodiments, the photoinitiator in step S2 can be any cleavage-type free radical photoinitiator, such as: any one or more of photoinitiator BDK (the main component is benzoin diethyl ether), photoinitiator 651 (the main component is dimethylbenzil ketal), photoinitiator 184 (the main component is 1-hydroxy-cyclohexyl benzophenone), TPO (the main component is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide), and the amount used is 0.5-2wt% of the total mass of the alicyclic copolyether intermediate and 3-mercaptopropionic acid.

[0023] In some embodiments, the irradiation power of the ultraviolet light in step S2 is 300-500 W, and the wavelength is 260-400 nm. Preferably, the irradiation power of the ultraviolet light is 350-450 W, and the wavelength is 365 nm.

[0024] According to another aspect of the present invention, the use of the above-mentioned alkali-soluble polyurethane acrylate resin in the preparation of a photosensitive dry film is provided. Specifically, the alkali-soluble polyurethane acrylate resin of the present invention is mixed with a reactive diluent, a photoinitiator, and a pigment to prepare a photosensitive dry film, which can obtain an image with good comprehensive performance and high resolution, and can have a good application prospect in the application fields of optical display, electronic manufacturing, UV encapsulation and coating protection of flat panel and flexible display devices.

[0025] Compared with the prior art, the beneficial effects of the present invention include:

[0026] (1) The alkali-soluble alicyclic copolyether resin prepared by ring-opening polymerization of the present invention not only retains the cyclic structure of 3,4-epoxycyclohexyl methacrylate itself, improves the rigidity of the resin, but also has a tetrahydrofuran flexible segment, and the present invention adopts ultraviolet light click reaction to give the resin alkali developing activity. The preparation process does not require high temperature and high pressure, the process is simple, and the reaction conditions are mild.

[0027] (2) The alkali-soluble alicyclic copolyether resin of the present invention has a moderate molecular weight, with a number average molecular weight of about 1900 g / mol, which effectively improves the development resolution, and has good flexibility and moderate acidity, which meets the application requirements of photosensitive resins.

[0028] (3) The process flow of the present invention is simple, suitable for large-scale production, and has high practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The schematic diagram is a synthetic route of the alkali-soluble alicyclic copolyether resin of the present invention.

[0030] Figure 2 This is the infrared spectrum of Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto. The raw materials and reagents involved in the following examples can be obtained from commercial channels. The schematic diagram of the synthetic route can be found in Figure 1 .

[0032] Example 1

[0033] The preparation method of the alkali-soluble alicyclic copolyether resin of this embodiment comprises the following steps:

[0034] (1) Add 0.62g 1,4-butanediol, 0.31g boron trifluoride etherate, 7.21g tetrahydrofuran, and 123.76g dichloromethane to a 500mL three-necked flask, stir, and cool. When the temperature is about 0°C, begin to drop 54.67g 3,4-epoxycyclohexyl methacrylate. After the dropwise addition is complete, raise the temperature to 20°C, continue the reaction for 5h, and then add 20mL pure water to the system to terminate the reaction. Add 100mL of dichloromethane, stir, separate the liquids, and evaporate the solvent to obtain the alicyclic copolyether intermediate. Figure 2 As shown in the infrared spectrum, the original 3,4-epoxycyclohexyl methacrylate has a 904 cm -1 The peak of the epoxy group disappears after the reaction, and the peak at 1725 cm-1 of 3,4-epoxycyclohexyl methacrylate -1 The C=O characteristic peak at 1635cm-1 and the C=C characteristic peak at 1635cm-1 indicate that the intermediate has been successfully synthesized.

[0035] (2) In a 500 mL three-necked flask, 55.07 g of alicyclic copolyether intermediate, 12.74 g of 3-mercaptopropionic acid, 0.71 g of photoinitiator BDK and 141.98 g of dichloromethane were added, and the mixture was reacted under 300 W, 365 nm ultraviolet light for 20 min, and then the dichloromethane was removed by rotary evaporation to obtain an alkali-soluble alicyclic copolyether. The infrared spectrum showed that at 3492 cm-1 The stretching vibration absorption peaks unique to hydroxyl groups appeared on the left and right, and 1635cm -1 The double bond peak at 240 is weakened, and mercaptopropionic acid has been successfully grafted to C=C of the intermediate. It can be seen that the functional group of the designed product of the present invention appears in the spectrum.

[0036] Example 2

[0037] The preparation method of the alkali-soluble alicyclic copolyether resin of this embodiment comprises the following steps:

[0038] (1) 0.62 g of 1,4-butanediol, 0.62 g of boron trifluoride etherate, 7.21 g of tetrahydrofuran, and 123.76 g of dichloromethane were added to a 500 mL three-necked flask, and the mixture was stirred and cooled. When the temperature was about 0° C., 54.67 g of 3,4-epoxycyclohexyl methacrylate was added dropwise. After the addition was completed, the temperature was raised to 20° C. and the reaction was continued for 5 h. 20 mL of pure water was added to the system to terminate the reaction. The liquids were separated and the solvent was evaporated to obtain an alicyclic copolyether intermediate.

[0039] (2) In a 500 mL three-necked flask, 55.07 g of the alicyclic copolyether intermediate, 12.74 g of 3-mercaptopropionic acid, 0.71 g of the photoinitiator BDK and 141.98 g of dichloromethane were added, and the mixture was reacted under 300 W, 365 nm ultraviolet light for 20 min, and then the dichloromethane was removed by rotary evaporation to obtain an alkali-soluble alicyclic copolyether.

[0040] Example 3

[0041] The preparation method of the alkali-soluble alicyclic copolyether resin of this embodiment comprises the following steps:

[0042] (1) 0.62 g of 1,4-butanediol, 0.93 g of boron trifluoride etherate, 7.21 g of tetrahydrofuran, and 123.76 g of dichloromethane were added to a 500 mL three-necked flask, and the mixture was stirred and cooled. When the temperature was about 0° C., 54.67 g of 3,4-epoxycyclohexyl methacrylate was added dropwise. After the addition was completed, the temperature was raised to 20° C. and the reaction was continued for 5 h. 20 mL of pure water was added to the system to terminate the reaction. The liquids were separated and the solvent was evaporated to obtain an alicyclic copolyether intermediate.

[0043] (2) In a 500 mL three-necked flask, 55.07 g of the alicyclic copolyether intermediate, 12.74 g of 3-mercaptopropionic acid, 0.71 g of the photoinitiator BDK and 141.98 g of dichloromethane were added, and the mixture was reacted under 300 W, 365 nm ultraviolet light for 20 min, and then the dichloromethane was removed by rotary evaporation to obtain an alkali-soluble alicyclic copolyether.

[0044] Example 4

[0045] The preparation method of the alkali-soluble alicyclic copolyether resin of this embodiment comprises the following steps:

[0046] (1) 0.62 g of 1,4-butanediol, 0.93 g of boron trifluoride etherate, 7.21 g of tetrahydrofuran, and 123.76 g of dichloromethane were added to a 500 mL three-necked flask, and the mixture was stirred and cooled. When the temperature was about 0° C., 54.67 g of 3,4-epoxycyclohexyl methacrylate was added dropwise. After the addition was completed, the temperature was raised to 20° C. and the reaction was continued for 5 h. 20 mL of pure water was added to the system to terminate the reaction. The liquids were separated and the solvent was evaporated to obtain an alicyclic copolyether intermediate.

[0047] (2) In a 500 mL three-necked flask, 55.07 g of the alicyclic copolyether intermediate, 15.92 g of 3-mercaptopropionic acid, 0.71 g of the photoinitiator BDK and 141.98 g of dichloromethane were added, and the mixture was reacted under 300 W, 365 nm ultraviolet light for 20 min, and then the dichloromethane was removed by rotary evaporation to obtain an alkali-soluble alicyclic copolyether.

[0048] Example 5

[0049] The preparation method of the alkali-soluble alicyclic copolyether resin of this embodiment comprises the following steps:

[0050] (1) 0.62 g of 1,4-butanediol, 0.93 g of boron trifluoride etherate, 7.21 g of tetrahydrofuran, and 123.76 g of dichloromethane were added to a 500 mL three-necked flask, and the mixture was stirred and cooled. When the temperature was about 0° C., 54.67 g of 3,4-epoxycyclohexyl methacrylate was added dropwise. After the addition was completed, the temperature was raised to 20° C. and the reaction was continued for 5 h. 20 mL of pure water was added to the system to terminate the reaction. The liquids were separated and the solvent was evaporated to obtain an alicyclic copolyether intermediate.

[0051] (2) In a 500 mL three-necked flask, 55.07 g of an alicyclic copolyether intermediate, 19.11 g of 3-mercaptopropionic acid, 0.71 g of a photoinitiator BDK and 141.98 g of dichloromethane were added, and the mixture was reacted under 300 W, 365 nm ultraviolet light for 20 min, and then the dichloromethane was removed by rotary evaporation to obtain an alkali-soluble alicyclic copolyether resin.

[0052] Next, the performance of the alkali-soluble alicyclic copolyether resins prepared in Examples 1-5 was tested.

[0053] First, the molecular weight of the alkali-soluble alicyclic copolyether resins prepared in Examples 1-5 was measured using a Waterse 2695 gel chromatograph. The test results are shown in Table 1.

[0054] Table 1 Molecular weight of alkali-soluble alicyclic copolyether resins prepared in Examples 1-5

[0055] sample Mn M Polydispersity Example 1 1173 1755 1.69 Example 2 1270 1853 1.73 Example 3 1361 1922 1.68 Example 4 1304 1955 1.85 Example 5 1373 1890 1.61

[0056] Then, the photosensitive dry film made of the alkali-soluble alicyclic copolyether resin prepared in Examples 1-5 was subjected to performance testing, and the testing method was as follows:

[0057] (1) Photosensitivity: The materials of the embodiments in Table 2 were mixed evenly and coated on the copper-clad laminate using a coating machine. The laminate was baked at 75° C. for 20 minutes. A 21-level light gradient ruler was placed on the film layer. The film layer was exposed and developed using an exposure machine with an LED light source. The time when 7 grids remained on the film layer was used as the standard.

[0058] (2) Minimum line spacing and line width: Tested in accordance with the method of GB / T 29846-2013 Photo-imaging electroplating resists for printed circuit boards.

[0059] (3) Etching resistance evaluation: The etching resistance is tested according to the method of GB / T 29846-2013 Photo-imaging Electroplating Resist for Printed Circuit Boards. After etching, the pattern is visually intact, the line edge is neat, and there is no wrinkling, shedding or dog-tooth shape. The evaluation is excellent. The wrinkling without shedding is good, and shedding is poor.

[0060] (4) Hardness evaluation: The hardness of the dry film prepared in the application example was measured according to GB / T1730-93.

[0061] (5) Flexibility evaluation: Flexibility: After lamination, exposure, and development, the prepared dry film was folded 20 times from different angles to observe whether the dry film cracked. The number of cracks was counted. The larger the value, the better the flexibility of the dry film.

[0062] Table 2 Components of application examples

[0063]

[0064] Among them, the weight of each component in Table 2 is calculated according to the solid content, and the solvent component is not included in the overall content of the composition (the mass percentage of the solvent is calculated with the solvent as the numerator and the composition as the denominator). The photoinitiator used is diphenyl (2,4,6-triformyl) phosphine oxide (photoinitiator TPO), the active diluent is bisphenol A dimethacrylate, the defoamer is a silane copolymer defoamer, and the leveling agent is polyacrylate. The test results of various indicators are shown in Table 3.

[0065] Table 3 Performance test results of alkali-soluble alicyclic copolyether resins of Examples 1-5

[0066]

[0067] It can be seen from the data in Table 3 that the alkali-soluble alicyclic copolyether resin of the present invention has excellent properties such as photosensitivity, etching resistance, hardness, and flexibility, and meets the application requirements of photosensitive dry films.

[0068] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An alkali-soluble polyurethane acrylate resin, characterized in that: Its structural formula is as follows: Wherein, a, b, and c represent mass fractions respectively, and satisfy a+b+c=1, 0.23≤a≤0.27, 0.365≤b≤0.385, and 0.365≤c≤0.

385.

2. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 1, characterized in that: The steps include: S1. Mix a solvent, a polyol, tetrahydrofuran and a catalyst, add 3,4-epoxycyclohexyl methacrylate dropwise at 0-5°C, then heat to 15-25°C, react for 4-6 hours, add water to terminate the reaction, and then remove the solvent to obtain an alicyclic copolyether intermediate; S2. Mix the alicyclic copolyether intermediate prepared in S1 with 3-mercaptopropionic acid, an organic solvent and a photoinitiator, react under ultraviolet light for 10-30 minutes, and then remove the solvent to obtain an alkali-soluble alicyclic copolyether.

3. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2, characterized in that: The molar ratio of the 3,4-epoxycyclohexyl methacrylate to the tetrahydrofuran in step S1 is (2-5):

1.

4. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2 or 3, characterized in that: The solvent in step S1 is one or more of acetone, dichloromethane, butanone, and toluene, and its usage is 1-3 times of the total mass of the 3,4-epoxycyclohexyl methacrylate and the tetrahydrofuran.

5. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2 or 3, characterized in that: In step S1, the catalyst is boron trifluoride ethyl ether, and the amount used is 0.5-3wt% of the total mass of the 3,4-epoxycyclohexyl methacrylate and the tetrahydrofuran.

6. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2 or 3, characterized in that: The polyol in step S1 is one or more of ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolpropane and trimethylolethane, and its usage is 0.5-2wt% of the total mass of the 3,4-epoxycyclohexyl methacrylate and the tetrahydrofuran.

7. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2 or 3, characterized in that: The structural formula of the alicyclic copolyether intermediate in step S1 is as follows: Wherein, a and b represent mass fractions respectively, and satisfy a+b=1, 0.24≤a≤0.26, 0.74≤b≤0.

76.

8. The method for preparing an alkali-soluble polyurethane acrylate resin according to claim 2, characterized in that: The molar ratio of the double bonds in the alicyclic copolyether intermediate to the thiol groups of the 3-mercaptopropionic acid in step S2 is 1:(0.4-0.6).

9. The method for preparing the alkali-soluble polyurethane acrylate resin according to claim 2 or 7, characterized in that: The organic solvent in step S2 is at least one of acetone, dichloromethane, butanone, and toluene, and its usage is 1-3 times of the total mass of the alicyclic copolyether intermediate and the 3-mercaptopropionic acid; the photoinitiator in step S2 can be any cleavage-type free radical photoinitiator, and its usage is 0.5-2wt% of the total mass of the alicyclic copolyether intermediate and the 3-mercaptopropionic acid.

10. Use of the alkali-soluble polyurethane acrylate resin according to claim 1 in preparing a photosensitive dry film.

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