Photosensitive resin composition and ductility regulation and control method of cured film of photosensitive resin composition

Abstract

The invention discloses a photosensitive resin composition and a ductility control method of a cured film thereof, the photosensitive resin composition comprises a photosensitive resin system and an elastic modifier, the elastic modifier is phthalate, and the mass ratio of the photosensitive resin system to the elastic modifier is (70-97): (3-30). During regulation and control, the elastic modifier is added into a photosensitive resin system at the temperature of 10-25 DEG C, and accurate regulation and control of the elastic modulus of a photosensitive resin composition cured film within the range of 2-13 GPa are achieved. The technical problems that existing photosensitive resin is single in ductility and difficult to adapt to different scene requirements are solved, and a prepared photosensitive resin composition cured film has excellent bonding strength, weather resistance and controllable ductility and can be widely applied to multiple fields such as electronic component packaging, optical device bonding and building sealing.

Description

Technical Field

[0001] This invention relates to the field of photosensitive resin technology, and more specifically to a photosensitive resin composition and a method for controlling the extensibility of its cured film. Background Technology

[0002] Photosensitive resins (UV-curable adhesives), as a class of functional materials that cure rapidly through polymerization reactions initiated by ultraviolet light, have been widely used in numerous fields such as electronics manufacturing, medical devices, automotive assembly, and building materials due to their outstanding advantages, including fast curing speed, excellent bonding strength, and convenient application. In the electronics field, photosensitive resins are used in processes such as electronic component encapsulation and circuit board coating, requiring resistance to vibration and impact during equipment operation to prevent cracking of the encapsulation layer and subsequent component failure. In the medical field, when used for bonding and sealing medical devices, photosensitive resins not only need good flexibility to accommodate the deformation requirements of the devices but also need to meet biocompatibility standards to ensure clinical safety. In the construction and automotive fields, structural component bonding scenarios require photosensitive resins to possess high hardness and structural stability to maintain the overall mechanical properties and service life of the assembly.

[0003] However, the control of the extensibility of photosensitive resins in existing technologies faces many bottlenecks. Currently, the extensibility of photosensitive resins is mainly determined by the molecular structure and cross-linking characteristics of the prepolymer (base resin). Products are typically prepared using a single type of prepolymer, resulting in a limited range of extensibility adjustment, usually only covering a specific interval and failing to meet the diverse needs of different scenarios. To expand the extensibility range, existing technologies often employ two improvement methods: First, adjusting extensibility by adding large amounts of polymer modifiers. However, this method significantly damages the cross-linking network structure of the photosensitive resin, leading to a substantial decrease in adhesive strength, poor aging resistance and weather resistance, and abnormal system viscosity, affecting application flowability. Second, adjusting extensibility by changing the type of prepolymer. However, as the core component of the resin system, changing the type of prepolymer requires re-optimizing the proportions of all supporting components such as reactive diluents, photoinitiators, and additives. This not only results in long R&D cycles and low production efficiency but also significantly increases production costs, making large-scale application difficult.

[0004] Therefore, there is an urgent need to develop a method for controlling the extensibility of photosensitive resin compositions and their cured films that has a stable formulation system, is easy to operate, and can achieve precise control of extensibility over a wide range without significantly affecting core properties such as adhesive strength, aging resistance, and workability. Summary of the Invention

[0005] The purpose of this invention is to overcome the technical defects of existing photosensitive resins, such as limited extensibility, difficulty in control, and easy performance imbalance after control. This invention provides a method for controlling the extensibility of a photosensitive resin composition and its cured film, enabling precise adjustment of the elastic modulus of the cured film of the photosensitive resin composition within the range of 2-13 GPa, while ensuring that the photosensitive resin composition has excellent workability and that its cured film maintains excellent adhesion strength and aging resistance.

[0006] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0007] The first aspect of this invention provides a photosensitive resin composition comprising a photosensitive resin system and an elastic modifier; wherein the photosensitive resin system comprises, by weight, the following components: 50-60 parts of base resin, 20-30 parts of reactive diluent, 3-6 parts of photoinitiator, 10-20 parts of solvent, and 1-5 parts of additives; the base resin is selected from one or more of epoxy acrylate, polyurethane acrylate, and polyester acrylate; the elastic modifier is phthalate; and the mass ratio of the photosensitive resin system to the elastic modifier is (70-97):(3-30).

[0008] Furthermore, the phthalate is selected from one or more of dibutyl phthalate, dioctyl phthalate and butyl benzyl phthalate, preferably dibutyl phthalate.

[0009] Further, the reactive diluent is trimethylolpropane triacrylate (TMPTA) and / or dipropylene glycol diacrylate (DPGDA). The reactive diluent functions to adjust the viscosity of the photosensitive resin composition and participates in the UV curing reaction to form a cross-linked network.

[0010] Further, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone (photoinitiator 1173) and / or phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819).

[0011] Furthermore, the solvent can be ethyl acetate, acetone, etc.

[0012] Furthermore, the additives include leveling agents and antioxidants. The leveling agent reduces the surface tension of the adhesive layer, preventing defects such as pinholes and orange peel after curing, and ensuring the smoothness of the optical surface. The antioxidant inhibits the oxidative degradation of the adhesive layer under high temperature or long-term light exposure, improving weather resistance.

[0013] Furthermore, the mass ratio of the leveling agent to the antioxidant is 1:(0.8-1.2).

[0014] Furthermore, the leveling agent may be polyether-modified polydimethylsiloxane, and the antioxidant may be antioxidant 1010.

[0015] The second aspect of the present invention provides the application of the photosensitive resin composition described in the first aspect in the encapsulation of electronic components, the bonding of optical devices, or the sealing of buildings.

[0016] A third aspect of the present invention provides a method for controlling the stretchability of a photosensitive resin composition cured film, comprising the following steps:

[0017] (1) An elastic modifier is added to the photosensitive resin system at 10-25 °C, and the photosensitive resin composition described in the first aspect is obtained after ultrasonic treatment.

[0018] (2) The photosensitive resin composition is cured by ultraviolet light irradiation to obtain a photosensitive resin composition cured film, and the elastic modulus of the photosensitive resin composition cured film is calibrated by adjusting the curing parameters; the curing parameters include: curing energy of 400-800 mJ / cm 2 The curing temperature is 15-25 ℃; the curing time is 30-60 s.

[0019] Further, in step (1), ultrasonic treatment is performed at a frequency of 45-60 kHz for 30-60 min.

[0020] Further, in step (2), the photosensitive resin composition is spin-coated and cured by ultraviolet light to obtain a photosensitive resin composition cured film.

[0021] Further, in step (2), the hardness of the photosensitive resin composition cured film is tested, and the hardness of the photosensitive resin composition cured film is 0.1-0.4 GPa.

[0022] Further, in step (2), the elastic modulus of the photosensitive resin composition cured film is tested, and the elastic modulus of the photosensitive resin composition cured film is 2-13 GPa.

[0023] With increasing addition of elastic modifier, the elastic modulus of the photosensitive resin composition cured film shows a trend of first increasing and then decreasing: when the addition of elastic modifier is 3-7 wt%, the elastic modulus of the photosensitive resin composition cured film is 7-13 GPa; when the addition of elastic modifier is 7-30 wt%, the elastic modulus of the photosensitive resin composition cured film is 2-7 GPa.

[0024] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0025] 1. This invention has a wide range of control over the extensibility of the photosensitive resin composition cured film, and can achieve precise adjustment of hardness from 0.1 to 0.4 GPa and elastic modulus from 2 to 13 GPa, fully covering the diversified performance requirements from high elastic modulus to high hardness, and can flexibly adapt to different application scenarios.

[0026] 2. The control process of this invention is precise, simple and efficient. The target performance can be achieved by simply adjusting the amount of elastic modifier added, without the need to make significant changes to the formula system. It is easy to operate and has high production efficiency.

[0027] 3. This invention can ensure that the cured film maintains excellent adhesion strength and aging resistance while precisely controlling the extensibility of the photosensitive resin composition. The uncured photosensitive resin composition also has good application fluidity, effectively solving the technical problem in the prior art where extensibility adjustment and core performance are mutually restrictive and prone to imbalance.

[0028] 4. The photosensitive resin composition provided by this invention, after being cured into a film on the surface of various commonly used substrates such as plastics, metals, and glass, has both excellent ductility and adhesion. It can be widely used in many fields such as electronic component packaging, medical device bonding, flexible material composites, optical device bonding, and building sealing. It has a wide range of applicable scenarios and is extremely practical. Attached Figure Description

[0029] Figure 1 This is a photograph of the photosensitive resin composition used in Example 1.

[0030] Figure 2 This is a fluorescence microscope image of the photosensitive resin composition cured film obtained in Example 1 after bending.

[0031] Figure 3 This is a fluorescence microscope image of the cured film of the photosensitive resin composition obtained in Example 2 after bending.

[0032] Figure 4 The images shown are actual photos of the photosensitive resin compositions in Examples 2-4; where (a) is Example 3, (b) is Example 4, and (c) is Example 2.

[0033] Figure 5 The image shows a fluorescence microscope image of the cured film of the photosensitive resin composition obtained in Comparative Example 1 after bending.

[0034] Figure 6 The images show the photosensitive resin system of Comparative Example 1, and the photosensitive resin compositions obtained in Comparative Example 3 and Comparative Example 4, from left to right: Comparative Example 1, Comparative Example 3, and Comparative Example 4.

[0035] Figure 7The images show the physical images of the photosensitive resin compositions obtained in Comparative Examples 5-7; where (a) is Comparative Example 5, (b) is Comparative Example 6, and (c) is Comparative Example 7. Detailed Implementation

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0038] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0039] Example 1

[0040] A method for controlling the extensibility of a photosensitive resin composition and its cured film includes the following steps:

[0041] (1) The photosensitive resin system and dibutyl phthalate were mixed evenly at a mass ratio of 9:1 at 20 °C, and then ultrasonically treated at a frequency of 53 kHz for 30 min to obtain a photosensitive resin composition (dibutyl phthalate accounts for 10% of the mass of the photosensitive resin composition). The actual picture is shown below. Figure 1 As shown. The photosensitive resin system comprises the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether-modified polydimethylsiloxane, and 0.5 parts antioxidant 1010.

[0042] (2) After spin-coating the photosensitive resin composition, the photosensitive resin composition is cured by ultraviolet light irradiation to obtain a cured film of photosensitive resin composition with a thickness of 5 µm; wherein, the spin-coating speed is 2000 r / s, and the curing energy of ultraviolet light is 500-800 mJ / cm 2 The curing time is 40 seconds and the curing temperature is 20 ℃.

[0043] The photosensitive resin composition cured film was subjected to a 180° bending test, and its morphology after bending was observed under a fluorescence microscope. The results are as follows. Figure 2 As shown.

[0044] Example 2

[0045] A method for controlling the extensibility of a photosensitive resin composition and its cured film includes the following steps:

[0046] (1) The photosensitive resin system and dibutyl phthalate were mixed evenly at a mass ratio of 7:3 at 20 °C, and then ultrasonically treated at a frequency of 53 kHz for 30 min to obtain a photosensitive resin composition (dibutyl phthalate accounts for 30% of the mass of the photosensitive resin composition). The photosensitive resin system includes the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether modified polydimethylsiloxane, and 0.5 parts antioxidant 1010.

[0047] (2) After spin-coating the photosensitive resin composition, the photosensitive resin composition is cured by ultraviolet light irradiation to obtain a cured film of photosensitive resin composition with a thickness of 5 µm; wherein, the spin-coating speed is 2000 r / s, and the curing energy of ultraviolet light is 500-800 mJ / cm 2 The curing time is 40 seconds and the curing temperature is 20 ℃.

[0048] The photosensitive resin composition cured film was subjected to a 180° bending test, and its morphology after bending was observed under a fluorescence microscope. The results are as follows. Figure 3 As shown.

[0049] Example 3

[0050] A method for controlling the extensibility of a photosensitive resin composition and its cured film includes the following steps:

[0051] (1) The photosensitive resin system and dibutyl phthalate were mixed evenly at a mass ratio of 97:3 at 20 °C, and then ultrasonically treated at a frequency of 53 kHz for 30 min to obtain a photosensitive resin composition (dibutyl phthalate accounts for 3% of the mass of the photosensitive resin composition). The photosensitive resin system includes the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether modified polydimethylsiloxane, and 0.5 parts antioxidant 1010.

[0052] (2) After spin-coating the photosensitive resin composition, the photosensitive resin composition is cured by ultraviolet light irradiation to obtain a cured film of photosensitive resin composition with a thickness of 5 µm; wherein, the spin-coating speed is 2000 r / s, and the curing energy of ultraviolet light is 500-800 mJ / cm 2 The curing time is 40 seconds and the curing temperature is 20 ℃.

[0053] Example 4

[0054] A method for controlling the extensibility of a photosensitive resin composition and its cured film includes the following steps:

[0055] (1) The photosensitive resin system and dibutyl phthalate were mixed evenly at a mass ratio of 93:7 at 20 °C, and then ultrasonically treated at a frequency of 53 kHz for 30 min to obtain a photosensitive resin composition (dibutyl phthalate accounts for 7% of the mass of the photosensitive resin composition). The photosensitive resin system includes the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether modified polydimethylsiloxane, and 0.5 parts antioxidant 1010.

[0056] (2) After spin-coating the photosensitive resin composition, the photosensitive resin composition is cured by ultraviolet light irradiation to obtain a cured film of photosensitive resin composition with a thickness of 5 µm; wherein, the spin-coating speed is 2000 r / s, and the curing energy of ultraviolet light is 500-800 mJ / cm 2 The curing time is 40 seconds and the curing temperature is 20 ℃.

[0057] The actual images of the photosensitive resin compositions in Examples 2-4 are shown below. Figure 4 As shown.

[0058] Comparative Example 1

[0059] A photosensitive resin system comprises the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether-modified polydimethylsiloxane, and 0.5 parts antioxidant 1010.

[0060] After spin-coating the photosensitive resin system, it was cured by ultraviolet light irradiation to obtain a cured photosensitive resin film with a thickness of 5 µm. The spin-coating speed was 2000 r / s, and the UV curing energy was 500-800 mJ / cm². 2 The curing time was 40 seconds, and the curing temperature was 20 °C. The cured film of the photosensitive resin system was subjected to a 180° bend test, and its morphology after bending was observed under a fluorescence microscope. The results are as follows: Figure 5 As shown.

[0061] Comparative Example 2

[0062] A photosensitive resin composition comprising a photosensitive resin system and polyvinylidene fluoride (PVDF); wherein the photosensitive resin system comprises the following components by weight: 55 parts epoxy acrylate, 25 parts TMPTA, 15 parts ethyl acetate, 4 parts photoinitiator 1173, 0.5 parts polyether-modified polydimethylsiloxane, and 0.5 parts antioxidant 1010; the mass ratio of the photosensitive resin system to PVDF is 95:5.

[0063] Five parts of PVDF were added to a 95-part photosensitive resin system at 20 ℃, and the mixture was ultrasonically treated at a frequency of 53 kHz for 30 min to obtain a photosensitive resin composition. Subsequently, the photosensitive resin composition was placed in a cool, dark place and allowed to stand for 72 h. It was observed that PVDF was not compatible with the photosensitive resin system.

[0064] Comparative Example 3

[0065] Weigh 100 mg PVDF and mix with 2 mL N,N-dimethylformamide (DMF), place in a brown glass bottle, and let stand in a cool place for 24 h until the PVDF is completely dissolved; take 200 μL of the PVDF / DMF solution and mix thoroughly with an appropriate amount of the photosensitive resin system of Comparative Example 1 to prepare a photosensitive resin mixture with a PVDF mass concentration of 1%; place the photosensitive resin mixture in an ultrasonic instrument and sonicate at 20 ℃ and 53 kHz for 30 min to obtain the photosensitive resin composition.

[0066] Comparative Example 4

[0067] Weigh 100 mg of PVDF and mix it with 2 mL of DMF. Place the mixture in a brown glass bottle and let it stand in a cool place for 24 h until the PVDF is completely dissolved. Take 400 μL of the PVDF / DMF solution and mix it thoroughly with an appropriate amount of the photosensitive resin system of Comparative Example 1 to prepare a photosensitive resin mixture with a PVDF mass concentration of 2%. Place the photosensitive resin mixture in an ultrasonic instrument and sonicate it at 20 ℃ and 53 kHz for 30 min to obtain the photosensitive resin composition.

[0068] Physical images of the photosensitive resin system of Comparative Example 1, and the photosensitive resin compositions obtained in Comparative Example 3 and Comparative Example 4 are shown below. Figure 6 As shown in the figure, it is clear from observation that PVDF in both Comparative Example 3 and Comparative Example 4 did not achieve good dissolution, and the overall dispersion compatibility was poor.

[0069] Comparative Example 5

[0070] The photosensitive resin system of Comparative Example 1 was mixed with polyvinylpyrrolidone (PVP) at a mass ratio of 99:1 at 20 °C, and then ultrasonicated at a frequency of 53 kHz for 60 min to obtain the photosensitive resin composition.

[0071] Comparative Example 6

[0072] The photosensitive resin system of Comparative Example 1 was mixed with PVP at a mass ratio of 97:3 at 20 °C, and then ultrasonicated at a frequency of 53 kHz for 60 min to obtain the photosensitive resin composition.

[0073] Comparative Example 7

[0074] The photosensitive resin system of Comparative Example 1 was mixed with PVP at a mass ratio of 95:5 at 20 °C, and then ultrasonicated at a frequency of 53 kHz for 60 min to obtain the photosensitive resin composition.

[0075] Physical images of the photosensitive resin compositions obtained in Comparative Examples 5-7 are shown below. Figure 7 As shown, the dissolution effect of PVP is poor.

[0076] Test Example 1

[0077] The photosensitive resin compositions in Examples 2-4 and the photosensitive resin system in Comparative Example 1 were spin-coated and cured by ultraviolet light irradiation to obtain a cured film of the photosensitive resin composition or system with a thickness of 1 mm. The spin-coating speed was 200 r / s, and the curing energy of the ultraviolet light was 500-800 mJ / cm². 2 The curing time is 40 seconds and the curing temperature is 20 ℃.

[0078] Mechanical properties were tested on the photosensitive resin compositions cured films obtained in Examples 2-4 and the photosensitive resin system cured film obtained in Comparative Example 1. A nanoindenter with a Glass indenter was used, with an indentation rate of 0.5 nm / s and a loading depth of 800 nm to measure the hardness and elastic modulus of the cured films. The test results are shown in Tables 1-4.

[0079] Table 1. Mechanical property test data of the photosensitive resin composition cured film obtained in Example 2

[0080]

[0081] Table 2. Mechanical property test data of the photosensitive resin composition cured film obtained in Example 3

[0082]

[0083] Table 3. Mechanical property test data of the photosensitive resin composition cured film obtained in Example 4

[0084]

[0085] Table 4. Test data of mechanical properties of the photosensitive resin system cured film obtained in Comparative Example 1

[0086]

[0087] As shown in Tables 1-4, the test results of each sample were repeated multiple times, and the data repeatability was good, which can objectively reflect the mechanical properties of the cured film. Among them, the photosensitive resin system cured film of Comparative Example 1 without elastic modifier exhibited high hardness and poor modulus adaptability. Its average Vickers hardness was about 36.4 HV, the average hardness was about 0.385 GPa, and the average elastic modulus was about 6.77 GPa. The single and hard characteristics of this cured film cannot meet the application requirements of photosensitive resin for adjustable flexibility and modulus in different application scenarios.

[0088] After modification with an elastic modifier, the Vickers hardness and hardness of the photosensitive resin compositions cured films obtained in Examples 2-4 showed a significant decreasing trend compared to Comparative Example 1, with the hardness stabilizing in the range of 0.093-0.180 GPa, fully demonstrating that the flexibility of the cured films was greatly improved after modification. At the same time, the elastic modulus of the photosensitive resin compositions cured films obtained in Examples 2-4 was precisely controlled in a differentiated manner. The average elastic modulus of the photosensitive resin compositions cured films obtained in Example 2 was about 2.89 GPa, the average elastic modulus of the photosensitive resin compositions cured films obtained in Example 4 was about 7.54 GPa, and the average elastic modulus of the photosensitive resin compositions cured films obtained in Example 3 reached 12.17 GPa.

[0089] In summary, by adding an elastic modifier to the photosensitive resin system, this invention enables precise control of the hardness and elastic modulus of the cured film of the photosensitive resin composition. This effectively solves the technical problem that existing photosensitive resins have limited mechanical properties and are difficult to adapt to different application scenarios. Based on the performance requirements of different scenarios such as electronic component packaging, optical device bonding, and building sealing, photosensitive resin cured products that meet the usage requirements can be specifically controlled.

[0090] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art should understand that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A photosensitive resin composition, characterized in that, The system comprises a photosensitive resin system and an elastic modifier; wherein the photosensitive resin system comprises, by weight, the following components: 50-60 parts of base resin, 20-30 parts of reactive diluent, 3-6 parts of photoinitiator, 10-20 parts of solvent, and 1-5 parts of additives; the base resin is selected from one or more of epoxy acrylate, polyurethane acrylate, and polyester acrylate; the elastic modifier is phthalate; and the mass ratio of the photosensitive resin system to the elastic modifier is (70-97):(3-30).

2. The photosensitive resin composition according to claim 1, characterized in that, The phthalate is selected from one or more of dibutyl phthalate, dioctyl phthalate, and butyl benzyl phthalate.

3. The photosensitive resin composition according to claim 1, characterized in that, The active diluent is trimethylolpropane triacrylate and / or dipropylene glycol diacrylate.

4. The photosensitive resin composition according to claim 1, characterized in that, The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone and / or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

5. The photosensitive resin composition according to claim 1, characterized in that, The additives include leveling agents and antioxidants; the mass ratio of the leveling agent to the antioxidant is 1:(0.8-1.2).

6. The use of a photosensitive resin composition according to any one of claims 1-5 in the encapsulation of electronic components, the bonding of optical devices, or the sealing of buildings.

7. A method for controlling the stretchability of a photosensitive resin composition cured film, characterized in that, Includes the following steps: (1) An elastic modifier is added to the photosensitive resin system at 10-25 °C, and the photosensitive resin composition according to any one of claims 1-5 is obtained after ultrasonic treatment. (2) The photosensitive resin composition is cured by ultraviolet light to obtain a photosensitive resin composition cured film, and the elastic modulus of the photosensitive resin composition cured film is calibrated by adjusting the curing parameters; The curing parameters include: curing energy of 400-800 mJ / cm². 2 ; The curing temperature is 15-25 ℃; the curing time is 30-60 s.

8. The method for controlling extensibility according to claim 7, characterized in that, In step (1), ultrasonic treatment is performed at a frequency of 45-60 kHz for 30-60 min.

9. The method for controlling extensibility according to claim 7, characterized in that, In step (2), the hardness of the cured film of the photosensitive resin composition is 0.1-0.4 GPa.

10. The method for controlling extensibility according to claim 7 or 9, characterized in that, In step (2), the elastic modulus of the cured film of the photosensitive resin composition is 2-13 GPa.

Images