Low-modulus and high-recovery optical pressure-sensitive adhesive based on polyurethane modified acrylate

Abstract

The invention discloses a preparation method of a low-modulus and high-recovery optical pressure-sensitive adhesive based on polyurethane modified acrylate. The optical pressure-sensitive adhesive comprises the following raw material components in parts by weight: 60-90 parts of alkyl acrylate, 5-20 parts of a polyurethane modified acrylate monomer, 5-20 parts of a functional monomer, 0.01-1 part of a curing agent and 0.01-1 part of a photoinitiator. The optical pressure-sensitive adhesive prepared by the invention has the characteristics of low modulus and high recovery, and can be used as a bonding material between functional layers of a folding screen mobile phone. The optical pressure-sensitive adhesive prepared by the invention has the characteristics of low modulus and high recovery, can absorb stress generated in the bending process of the folding screen mobile phone, prolongs the service life of the folding screen mobile phone, also helps to improve the crease problem of the folding screen mobile phone, and can be widely applied to the field of folding screen mobile phones.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of adhesive materials, in particular to a low modulus and high recovery optical pressure-sensitive adhesive based on polyurethane modified acrylate. BACKGROUND

[0002] With the rapid development of information and electronic industry, advanced display technologies such as foldable, stretchable and curlable have attracted widespread attention and will have great development space in the future. However, the development of these new technologies poses new challenges to optical pressure-sensitive adhesive. Traditional optical pressure-sensitive adhesive cannot meet the use requirements, and there are problems such as debonding, buckling and fracture during bending. Therefore, optical pressure-sensitive adhesive not only needs to have good bonding effect, but also needs to have lower modulus to absorb the stress generated by bending, and high recovery to prevent buckling under repeated bending. Therefore, it is very urgent and important to prepare a low modulus and high recovery optical pressure-sensitive adhesive. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a method for preparing a low modulus and high recovery optical pressure-sensitive adhesive based on polyurethane modified acrylate, in view of the deficiencies in the prior art.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a low modulus and high recovery optical pressure-sensitive adhesive based on polyurethane modified acrylate, comprising the following raw material components by weight: 60-90 parts of alkyl acrylate, 5-20 parts of polyurethane modified acrylate monomer, 5-20 parts of functional monomer, 0.01-1 part of curing agent and 0.01-1 part of photoinitiator.

[0005] Preferably, the alkyl acrylate is one or more of butyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, n-octyl acrylate, decyl acrylate, lauryl acrylate or stearyl acrylate.

[0006] Preferably, the raw materials for preparing the polyurethane modified acrylate monomer include: 1 mol of diisocyanate, 0.9-1.1 mol of dihydric alcohol, 0.9-1.1 mol of acrylate hydroxy ester, catalyst and polymerization inhibitor. The amount of catalyst and polymerization inhibitor is 0-0.1% and 0-0.1%, respectively, based on the total mass of diisocyanate, dihydric alcohol and acrylate hydroxy ester.

[0007] Preferably, the diisocyanate is one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, diphenyl methane diisocyanate and dicyclohexyl methane diisocyanate.

[0008] Preferably, the diol is one or more of polytetrahydrofuran diol, polycaprolactone diol, polyethylene glycol, polypropylene glycol, and polycarbonate diol (all with a molecular weight of 200-1000).

[0009] Preferably, the hydroxy acrylate is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0010] Preferably, the catalyst is one or more of dibutyltin dilaurate, stannous octoate, and dimethyltin diacetate; The polymerization inhibitor is one or more of hydroquinone, p-hydroxyanisole, and p-benzoquinone.

[0011] Preferably, the functional monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and glycidyl methacrylate.

[0012] Preferably, the curing agent is one or more of 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol hexaacrylate. The photoinitiator is one or more of 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl)phosphonate, 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,2-dimethoxy-2-phenylethyl ketone.

[0013] This invention also provides a preparation method for a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate as described above, comprising the following steps: S1. Preparation of polyurethane-modified acrylate monomers: Diisocyanate, catalyst, and polymerization inhibitor are mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. Stirring is then started and nitrogen is introduced for 15-30 minutes. The temperature is raised to 50-60°C, and acrylate hydroxy ester is added to react until the isocyanate content drops to the theoretical value. Diol is added and the temperature is raised to 75-85°C, and the reaction continues until the isocyanate content drops to 0, thus obtaining polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: Alkyl acrylate, polyurethane-modified acrylate monomer, functional monomer, and part of photoinitiator are mixed, then stirred and nitrogen gas is introduced for 15-30 minutes. The reaction is then irradiated with an LED lamp to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: The remaining photoinitiator and curing agent are added to the polyurethane-modified acrylate prepolymer, stirred evenly, and then coated onto a release film. Another release film is then attached to the adhesive surface and cured under ultraviolet light to obtain the low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate.

[0014] The beneficial effects of this invention are: This invention provides a low-modulus, high-resilience optical pressure-sensitive adhesive based on polyurethane-modified acrylate and its method. The optical pressure-sensitive adhesive prepared by this invention has the characteristics of low modulus and high resilience, which can absorb the stress generated during the bending process of foldable screen mobile phones, improve their service life, and also help to improve their crease problem. It can be widely used in the field of foldable screen mobile phones.

[0015] The polyurethane-modified acrylate monomer in the optical pressure-sensitive adhesive formulation of this invention can reduce the modulus of the optical pressure-sensitive adhesive and improve the recovery ratio. This is mainly because the polyurethane molecular chain has a block structure with alternating soft and hard segments. This unique micro-phase separation structure enables it to have good adhesive strength while having a low modulus. In addition, the urethane and other groups in the polyurethane provide more physical crosslinking points, which can give it high elasticity. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0017] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0018] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0019] This invention provides a method for developing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate, comprising the following raw material components by weight: 60-90 parts of alkyl acrylate, 5-20 parts of polyurethane-modified acrylate monomer, 5-20 parts of functional monomer, 0.01-1 parts of curing agent, and 0.01-1 parts of photoinitiator.

[0020] In a preferred embodiment, the alkyl acrylate is one or more of butyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, n-octyl acrylate, decyl acrylate, lauryl acrylate, or octadecyl acrylate.

[0021] In a preferred embodiment, the raw materials for preparing the polyurethane-modified acrylate monomer include: 1 mol of diisocyanate, 0.9-1.1 mol of diol, 0.9-1.1 mol of hydroxy acrylate, a catalyst, and a polymerization inhibitor; The amounts of catalyst and polymerization inhibitor are 0-0.1% and 0-0.1% of the total mass of diisocyanate, diol and hydroxy acrylate, respectively.

[0022] The statement that the amount of catalyst and polymerization inhibitor is 0 indicates that no catalyst or polymerization inhibitor may be added. However, in a more preferred embodiment, the amounts of catalyst and polymerization inhibitor are 0.01-0.1% and 0.01-0.1% of the total mass of diisocyanate, diol and hydroxy acrylate, respectively.

[0023] In a preferred embodiment, the diisocyanate is one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethane diisocyanate.

[0024] In a preferred embodiment, the diol is one or more of polytetrahydrofuran diol, polycaprolactone diol, polyethylene glycol, polypropylene glycol, and polycarbonate diol (all with a molecular weight of 200-1000).

[0025] In a preferred embodiment, the hydroxy acrylate is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0026] In a preferred embodiment, the catalyst is one or more of dibutyltin dilaurate, stannous octoate, and dimethyltin diacetate.

[0027] In a preferred embodiment, the polymerization inhibitor is one or more of hydroquinone, p-hydroxyanisole, and p-benzoquinone.

[0028] In a preferred embodiment, the functional monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and glycidyl methacrylate.

[0029] In a preferred embodiment, the curing agent is one or more of 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol hexaacrylate.

[0030] In a preferred embodiment, the photoinitiator is one or more of 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl)phosphonate, 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,2-dimethoxy-2-phenylethyl ketone.

[0031] This invention also provides a method for developing a low-modulus, high-resilience optical pressure-sensitive adhesive based on polyurethane-modified acrylate, comprising the following steps: S1. Preparation of polyurethane-modified acrylate monomers: 1 mol of diisocyanate, 0-0.1% of catalyst, and 0-0.1% of polymerization inhibitor were mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. The stirring was then turned on and nitrogen was introduced for 15-30 minutes. The temperature was raised to 55°C, and 0.9-1.1 mol of acrylate hydroxy ester was added. The reaction proceeded until the isocyanate content dropped to the theoretical value (determined by the acetone-di-n-butylamine method). 0.9-1.1 mol of diol was added and the temperature was raised to 80°C. The reaction proceeded until the isocyanate content dropped to 0, thus obtaining polyurethane-modified acrylate monomer. The amounts of catalyst and polymerization inhibitor are 0-0.1% and 0-0.1% of the total mass of diisocyanate, diol and hydroxy acrylate, respectively.

[0032] S2. Preparation of polyurethane-modified acrylate prepolymer: Mix 60-90 parts of alkyl acrylate, 5-20 parts of polyurethane-modified acrylate monomer, 5-20 parts of functional monomer, and 0.01-1 parts of photoinitiator, then turn on the stirrer and purge with nitrogen for 15-30 minutes. Use an LED lamp to irradiate the reaction to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: Add 0.01-1 parts photoinitiator and 0.01-1 parts curing agent to the polyurethane modified acrylate prepolymer by weight, stir to mix evenly, then coat it onto the release film, and then attach another release film to the adhesive surface. Cure under ultraviolet light to obtain optical pressure-sensitive adhesive.

[0033] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0034] Example 1 A method for preparing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate includes the following steps: S1. Preparation of polyurethane-modified acrylate monomers: 1 mol of isophorone diisocyanate, 0.05% dibutyltin dilaurate, and 0.05% hydroquinone (the amounts of catalyst and polymerization inhibitor refer to their percentages relative to the total mass of diisocyanate, diol, and hydroxyl acrylate) were mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. The stirring was then turned on and nitrogen was introduced for 20 min. The temperature was raised to 55 °C, and 1 mol of hydroxyethyl acrylate was added. The reaction proceeded until the isocyanate content dropped to half of the initial value (determined by the acetone-di-n-butylamine method). 1.05 mol of polyethylene glycol (molecular weight 400) was added and the temperature was raised to 80 °C. The reaction proceeded until the isocyanate content dropped to 0, yielding polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: 60 parts of 2-ethylhexyl acrylate, 20 parts of lauryl acrylate, 10 parts of polyurethane-modified acrylate monomer, 10 parts of hydroxybutyl acrylate, and 0.1 parts of photoinitiator were mixed. Then, stirring was started and nitrogen was introduced for 20 minutes. The reaction was carried out by irradiating with a 5W LED lamp at a distance of 10 cm from the reactor until the viscosity reached 4500 cps to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: According to weight, add 0.1 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 parts of 1,6-hexanediol diacrylate to the polyurethane modified acrylate prepolymer, stir to mix evenly, then coat it onto a release film, and attach another release film to the adhesive side of the film. At 10000 mJ / cm 2 The optical pressure-sensitive adhesive is cured under ultraviolet light.

[0035] Example 2 A method for preparing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate includes the following steps: S1. Preparation of polyurethane-modified acrylate monomers: 1 mol of isophorone diisocyanate, 0.05% dibutyltin dilaurate, and 0.05% hydroquinone (the amount of catalyst and polymerization inhibitor refers to their percentage of the total mass of diisocyanate, diol, and hydroxy acrylate) were mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. The stirring was then turned on and nitrogen was introduced for 20 min. The temperature was raised to 55°C, and 1 mol of hydroxybutyl acrylate was added. The reaction continued until the isocyanate content dropped to half of the initial value (determined by the acetone-di-n-butylamine method). 1.05 mol of polyethylene glycol (molecular weight 400) was added and the temperature was raised to 80°C. The reaction continued until the isocyanate content dropped to 0, thus obtaining polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: 60 parts of 2-ethylhexyl acrylate, 20 parts of lauryl acrylate, 10 parts of polyurethane-modified acrylate monomer, 10 parts of hydroxybutyl acrylate, and 0.1 parts of photoinitiator were mixed. Then, stirring was started and nitrogen was introduced for 20 minutes. The reaction was carried out by irradiating with a 5W LED lamp at a distance of 10 cm from the reactor until the viscosity reached 4500 cps to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: According to weight, add 0.1 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 parts of 1,6-hexanediol diacrylate to the polyurethane modified acrylate prepolymer, stir to mix evenly, then coat it onto a release film, and attach another release film to the adhesive side of the film. At 10000 mJ / cm 2 The optical pressure-sensitive adhesive is cured under ultraviolet light.

[0036] Example 3 A method for preparing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate includes the following steps: S1. Preparation of polyurethane-modified acrylate monomers: 1 mol of toluene diisocyanate, 0.05% dibutyltin dilaurate, and 0.05% hydroquinone (the amounts of catalyst and polymerization inhibitor refer to their percentages relative to the total mass of diisocyanate, diol, and hydroxyl acrylate) were mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. The stirring was then started and nitrogen was introduced for 20 min. The temperature was raised to 55 °C, and 1 mol of hydroxybutyl acrylate was added. The reaction proceeded until the isocyanate content decreased to half of the initial value (determined by the acetone-di-n-butylamine method). 1.05 mol of polyethylene glycol (molecular weight 400) was added, and the temperature was raised to 80 °C. The reaction proceeded until the isocyanate content decreased to 0, yielding polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: 60 parts of 2-ethylhexyl acrylate, 20 parts of lauryl acrylate, 10 parts of polyurethane-modified acrylate monomer, 10 parts of hydroxybutyl acrylate, and 0.1 parts of photoinitiator were mixed. Then, stirring was started and nitrogen was introduced for 20 minutes. The reaction was carried out by irradiating with a 5W LED lamp at a distance of 10 cm from the reactor until the viscosity reached 4500 cps to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: According to weight, add 0.1 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 parts of 1,6-hexanediol diacrylate to the polyurethane modified acrylate prepolymer, stir to mix evenly, then coat it onto a release film, and attach another release film to the adhesive side of the film. At 10000 mJ / cm 2 The optical pressure-sensitive adhesive is cured under ultraviolet light.

[0037] Example 4 A method for preparing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate includes the following steps: S1. Preparation of polyurethane-modified acrylate monomers: 1 mol of isophorone diisocyanate, 0.05% dibutyltin dilaurate, and 0.05% hydroquinone (the amount of catalyst and polymerization inhibitor refers to their percentage of the total mass of diisocyanate, diol, and hydroxy acrylate) were mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. The stirring was then turned on and nitrogen was introduced for 20 min. The temperature was raised to 55 °C, and 1 mol of hydroxybutyl acrylate was added. The reaction continued until the isocyanate content dropped to half of the initial value (determined by the acetone-di-n-butylamine method). 1.05 mol of polycaprolactone diol (molecular weight 400) was added and the temperature was raised to 80 °C. The reaction continued until the isocyanate content dropped to 0, thus obtaining polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: 60 parts of 2-ethylhexyl acrylate, 20 parts of lauryl acrylate, 10 parts of polyurethane-modified acrylate monomer, 10 parts of hydroxybutyl acrylate, and 0.1 parts of photoinitiator were mixed. Then, stirring was started and nitrogen was introduced for 20 minutes. The reaction was carried out by irradiating with a 5W LED lamp at a distance of 10 cm from the reactor until the viscosity reached 4500 cps to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: According to weight, add 0.1 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 parts of 1,6-hexanediol diacrylate to the polyurethane modified acrylate prepolymer, stir to mix evenly, then coat it onto a release film, and attach another release film to the adhesive side of the film. At 10000 mJ / cm 2 The optical pressure-sensitive adhesive is cured under ultraviolet light.

[0038] Comparative Example 1 A method for preparing an optical pressure-sensitive adhesive includes the following steps: S1. Preparation of acrylate prepolymer: 70 parts of 2-ethylhexyl acrylate, 20 parts of lauryl acrylate, 10 parts of hydroxybutyl acrylate, and 0.1 parts of photoinitiator were mixed, and then stirred and nitrogen gas was introduced for 20 minutes. The reaction was carried out by irradiating with a 5W LED lamp at a distance of 10 cm from the reactor until the viscosity reached 4500 cps to obtain the acrylate prepolymer. S2. Preparation of optical pressure-sensitive adhesive: According to weight, add 0.1 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 parts of 1,6-hexanediol diacrylate to the acrylate prepolymer, stir to mix evenly, then coat it onto a release film, and attach another release film to the adhesive side of the prepolymer. At 10000 mJ / cm 2 The optical pressure-sensitive adhesive is cured under ultraviolet light.

[0039] Performance testing The optical pressure-sensitive adhesives prepared in the examples and comparative examples were subjected to the following performance tests: 1. Rheological test: A circular sample with a thickness of 0.8 mm and a diameter of 8 mm is placed between the probes of the ARES-G2 rheometer and the temperature is scanned from -50 to 100 °C at a heating rate of 3 °C / min. The Tg, storage modulus and loss modulus of the sample are tested.

[0040] 2. Creep Test: A circular sample with a thickness of 0.8 mm and a diameter of 8 mm is placed between the probes of the ARES-G2 rheometer. A shear stress of 10 kPa is applied and held for 600 s. The applied stress is then removed and the sample is allowed to recover for 600 s. The creep performance of the sample is then tested. The maximum deformation and the recovery ratio after 600 s are recorded.

[0041] 3. 180° Peel Strength Test: Remove the release film from one side of the 50µm thick optical pressure-sensitive adhesive from Examples 1-4 and Comparative Example 1, transfer it to a 50µm plasma-treated PET, cut it into samples 30mm long and 25.4mm wide, then remove the release film from the other side of the optical pressure-sensitive adhesive, and use a 2kg rubber roller to laminate the PET film onto the surface of the plasma-treated substrate. After standing for 24 hours in an environment of 23℃ and 50%RH, test its peel strength using a tensile testing machine.

[0042] The test results for each embodiment and comparative example are shown in Table 1: Table 1 The performance test results of Examples 1-4 and Comparative Example 1 show that polyurethane-modified acrylate monomers can reduce the modulus of optical pressure-sensitive adhesives and improve the recovery ratio. This is mainly because the polyurethane molecular chain has a block structure with alternating soft and hard segments. This unique microscopic phase separation structure allows it to have good adhesive strength while possessing low modulus. In addition, urethane and other groups in polyurethane provide more physical crosslinking points, giving it high elasticity.

[0043] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate, characterized in that, It includes the following raw material components by weight: 60-90 parts alkyl acrylate, 5-20 parts polyurethane modified acrylate monomer, 5-20 parts functional monomer, 0.01-1 part curing agent and 0.01-1 part photoinitiator.

2. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 1, characterized in that, The alkyl acrylate is one or more of butyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, n-octyl acrylate, decyl acrylate, lauryl acrylate, or octadecyl acrylate.

3. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 1, characterized in that, The raw materials for preparing the polyurethane-modified acrylate monomer include: 1 mol of diisocyanate, 0.9-1.1 mol of diol, 0.9-1.1 mol of hydroxy acrylate, catalyst, and polymerization inhibitor; The amounts of catalyst and polymerization inhibitor are 0-0.1% and 0-0.1% of the total mass of diisocyanate, diol and hydroxy acrylate, respectively.

4. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 3, characterized in that, The diisocyanate is one or more of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethane diisocyanate.

5. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 3, characterized in that, The diol is one or more of polytetrahydrofuran diol, polycaprolactone diol, polyethylene glycol, polypropylene glycol, and polycarbonate diol (all with a molecular weight of 200-1000).

6. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 3, characterized in that, The hydroxy acrylate is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

7. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 3, characterized in that, The catalyst is one or more of the following: dibutyltin dilaurate, stannous octoate, and dimethyltin diacetate. The polymerization inhibitor is one or more of hydroquinone, p-hydroxyanisole, and p-benzoquinone.

8. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 1, characterized in that, The functional monomer is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and glycidyl methacrylate.

9. The low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate according to claim 1, characterized in that, The curing agent is one or more of 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol hexaacrylate; The photoinitiator is one or more of 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl)phosphonate, 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,2-dimethoxy-2-phenylethyl ketone.

10. A method for preparing a low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Preparation of polyurethane-modified acrylate monomers: Diisocyanate, catalyst, and polymerization inhibitor are mixed in a four-necked flask equipped with a stirrer, condenser, thermometer, and nitrogen tube. Stirring is then started and nitrogen is introduced for 15-30 minutes. The temperature is raised to 50-60°C, and acrylate hydroxy ester is added to react until the isocyanate content drops to the theoretical value. Diol is added and the temperature is raised to 75-85°C, and the reaction continues until the isocyanate content drops to 0, thus obtaining polyurethane-modified acrylate monomer. S2. Preparation of polyurethane-modified acrylate prepolymer: Alkyl acrylate, polyurethane-modified acrylate monomer, functional monomer, and part of photoinitiator are mixed, then stirred and nitrogen gas is introduced for 15-30 minutes. The reaction is then irradiated with an LED lamp to obtain polyurethane-modified acrylate prepolymer. S3. Preparation of optical pressure-sensitive adhesive: The remaining photoinitiator and curing agent are added to the polyurethane-modified acrylate prepolymer, stirred evenly, and then coated onto a release film. Another release film is then attached to the adhesive surface and cured under ultraviolet light to obtain the low-modulus, high-response optical pressure-sensitive adhesive based on polyurethane-modified acrylate.

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