EPU glue and preparation method thereof

Abstract

The invention relates to the field of electronic product protective film synthetic materials, in particular to EPU glue and a preparation method thereof. The invention relates to a photoinitiator, which comprises the following components in parts by weight: 20-70 parts of modified aliphatic polyurethane acrylate, 10-30 parts of monomer, 0.5-6 parts of photoinitiator, 0.2-3 parts of assistant and 10-90 parts of diluent. The modified aliphatic polyurethane acrylate is prepared from H6XDI hexahydrom-xylylene diisocyanate, C12-C14 aliphatic carbonate diol, trifunctional aliphatic polyol, isophorone diisocyanate, triisocyanate, toluene diisocynate, a curing agent, an initiator, an initiator, an initiator, a catalyst and a solvent. At least one of diphenylmethane diisocyanate is combined with the monomer and polymerized with the cyclic molecular compound to form a slip network polymer, and a molecular chain of the slip network polymer can move among crosslinking points.

Description

Technical Field

[0001] The present invention relates to the field of electronic product protective film synthetic materials, in particular to an EPU glue and a preparation method thereof. Background Art

[0002] With the rapid development of flexible electronic devices and high-performance film materials, the market demand for glue materials with high flexibility, excellent adhesion, wear resistance, and self-healing functions continues to increase, especially in the fields of foldable screen mobile phones, flexible displays, privacy films, optical coatings, etc., the technical requirements for glue are particularly strict. EPU (polyurethane acrylate) glue has become one of the important materials in these high-end applications due to its excellent mechanical properties, excellent optical transparency and good processability; after testing, the existing EPU glue still has many technical deficiencies:

[0003] 1. After the existing EPU glue forms a film on the release film, it is easy to cause insufficient adhesion of the subsequent anti-peep and self-repair coatings, affecting the performance and durability of the overall film layer.

[0004] 2. Many EPU glue film-forming solutions on the market rely on release films and are not compatible with unused and untreated high-transparency, low-haze PET base films, which limits their scope of application. Summary of the invention

[0005] The purpose of this application is to provide a technical solution to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] An EPU glue comprises the following components in weight ratio:

[0008]

[0009] The modified aliphatic polyurethane acrylate is prepared by polymerizing at least one of H6XDI hexahydro-m-xylylene diisocyanate, C12-C14 aliphatic carbonate diol, trifunctional aliphatic polyol, isophorone diisocyanate, triisocyanate, toluene diisocyanate and diphenylmethane diisocyanate with the monomers and cyclic molecular compounds to form a slip network polymer, and the molecular chain of the polymer can move between crosslinking points.

[0010] Preferably, the cyclic molecular compound is any one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

[0011] Preferably, the monomer is any one or more of the functional monomer THFA tetrahydrofuran acrylate, the bifunctional monomer TPGDA tripropylene glycol diacrylate, and DPGDA dipropylene glycol diacrylate.

[0012] Preferably, the photoinitiator is any one or more of phenyl dibenzoyl oxide, bisdifluorophenyl chloride, and toluene diperoxide.

[0013] Preferably, the auxiliary agent is any one or more of urethane acrylate, mercaptoacetic acid acrylate, epoxy acrylate.

[0014] A method for preparing EPU glue comprises the following steps:

[0015] (1) Add 20-70 parts of modified aliphatic polyurethane acrylate and 10-30 parts of monomer in a light-shielded reaction kettle in order by weight; stir evenly by ultrasonic dispersion, set the speed to 800-1500 rpm, the time to 5-30 min, and the temperature to 25-35° C.;

[0016] (2) After ultrasonic dispersion and stirring, add the following in order by weight: 0.5-6 parts of photoinitiator, 0.2-3 parts of auxiliary agent, 10-90 parts of diluent, stir slowly and evenly, set the speed to 300-500 rpm, the time to 10-20 min, and the temperature to 25-35°C;

[0017] (3) Vacuum degassing by vacuum machine;

[0018] (4) discharging the material to obtain EPU glue;

[0019] (5) The obtained EPU glue is stored in an environment shielded from ultraviolet light.

[0020] In summary, the technical effects and advantages of the present invention are as follows:

[0021] 1. After the EPU glue of the present invention is formed on the release film, the cross-linked structure of the cyclic molecular compound provides self-repairing ability, so that the adhesion of the anti-peeping and self-repairing coatings is excellent, and the performance and durability of the overall film layer are improved; therefore, the EPU glue of the present invention is used in the self-repairing film layer to efficiently and automatically repair fine scratches and maintain a lasting and smooth appearance.

[0022] 2. The EPU glue of this solution can replace the existing release film after film formation, so it is compatible with unused and untreated high-transparency, low-haze PET base film, expanding the application range of EPU glue.

[0023] 3. This solution uses modified aliphatic polyurethane acrylate to achieve high flexibility of EPU glue, making it more suitable for use in bendable and dynamically used scenarios, such as protective films for folding screens and flexible display devices.

[0024] 5. The modified polyurethane acrylate in this solution has good wear resistance, so that the EPU glue can maintain surface integrity for a long time when applied to the protective film, thereby extending the service life of the product.

[0025] 6.EPU glue combined with the monomer and photoinitiator prepared in this solution can achieve rapid curing in a short time, greatly improving production efficiency and reducing process time. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] An EPU glue is made from the following raw materials in parts by weight: 40 parts of modified aliphatic polyurethane acrylate (Covestro H6XDI hexahydro-m-xylylene diisocyanate), 32 parts monomer (Arkema TPGDA tripropylene glycol diacrylate), 4.5 parts of cyclic molecular compound (Wacker Chemie α-cyclodextrin), 42 parts of diluent (Eastman Chemical propylene glycol methyl ether acetate), 2 parts of photoinitiator (IGM Resins 1173 phenyl dibenzoyl oxide), 1.5 parts of auxiliary agent (Evonik Rad 2100 epoxy acrylate).

[0029] Preparation method: In a light-shielded reactor, first add in order by weight: 40 parts of modified aliphatic polyurethane acrylate (Covestro H6XDI hexahydro-m-phenylenediisocyanate), 4.5 parts of cyclic molecular compound (Wacker Chemie α-cyclodextrin). Ultrasonic dispersion and stirring, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. After ultrasonic dispersion, add 32 parts of monomer by weight (Arkema TPGDA tripropylene glycol diacrylate), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30℃. Add 42 parts of diluent (Eastman Chemical Eastman Chemical propylene glycol methyl ether acetate), stir further, keep the speed at 500-800rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30℃. Then add in order by weight: 2 parts of photoinitiator (IGM Resins 1173 phenyl dibenzoyl oxide), 1.5 parts of auxiliary agent (Evonik Rad 2100 epoxy acrylate), keep the temperature at 25-30℃, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the auxiliary agent are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0030] Embodiment 2:

[0031] An EPU glue is made from the following raw materials in parts by weight: 50 parts of modified aliphatic polyurethane acrylate (BASF IPDI isophorone diisocyanate), 33 parts of monomer (Ashland HDDA 1,6-hexanediol diacrylate), 4.8 parts of cyclic molecular compound (Evonik β-cyclodextrin), 41 parts of diluent (Dow Chemical ethyl acetate), 2.5 parts of photoinitiator (IGM Resins 184 1-hydroxycyclohexyl phenyl ketone), 1.2 parts of auxiliary agent (BYK BYK-333 from Germany).

[0032] Preparation method: In a light-shielded reactor, first add in order by weight: 50 parts of modified aliphatic polyurethane acrylate (BASF IPDI isophorone diisocyanate), 4.8 parts of cyclic molecular compounds (Evonik β-cyclodextrin). Ultrasonic dispersion and stirring evenly, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Next, 33 parts of monomer (Ashland HDDA 1,6-hexanediol diacrylate) are added by weight, and stirring is continued for 5-10 minutes, the speed is maintained at 500-800rpm, and the monomer is fully mixed with other components, and the temperature is maintained at 25-30°C. Subsequently, 41 parts of diluent (Dow Chemical Dow Chemical ethyl acetate) are added, and further stirring is carried out, the speed is maintained at 500-800rpm, and the time is set to 5-10 minutes to ensure that the viscosity is reasonably adjusted and the temperature is controlled at 25-30°C. Then, 2.5 parts of photoinitiator (IGM Resins Ai Kemu) are added in sequence by weight. 184 1-hydroxycyclohexyl phenyl ketone), 1.2 parts of auxiliary agent (BYK-333 from BYK Germany), keep the temperature at 25-30℃, stir evenly at a slow speed, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and auxiliary agent are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged.

[0033] Finally, the material is discharged to obtain EPU glue

[0034] Embodiment 3:

[0035] An EPU glue is made from the following raw materials in parts by weight: 46 parts of modified aliphatic polyurethane acrylate (Covestro N3400 triisocyanate), 31 parts of monomer (Sumitomo Chemical PETA pentaacrylate), 4.4 parts of cyclic molecular compound (Mitsubishi Chemical γ-cyclodextrin), 40 parts of diluent (Dow Chemical propylene glycol ethyl ether), 1.8 parts of photoinitiator (IGM Resins 651 phenyl dibenzoyl oxide), 1.3 parts of auxiliary agent (BYK-306 from BYK Germany).

[0036] Preparation method: In a light-shielded reactor, first add in order by weight: 46 parts of modified aliphatic polyurethane acrylate (Covestro N3400 triisocyanate), 4.4 parts of cyclic molecular compounds (Mitsubishi Chemical γ-cyclodextrin). Ultrasonic dispersion and stirring evenly, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Next, 31 parts of monomer (Sumitomo Chemical PETA) are added by weight, and stirring is continued for 5-10 minutes, with the speed maintained at 500-800rpm to ensure that the monomer is fully mixed with other components and the temperature is maintained at 25-30°C. Subsequently, 40 parts of diluent (Dow Chemical Dow Chemical propylene glycol ethyl ether) are added for further stirring, maintaining the speed at 500-800rpm, the time set to 5-10 minutes, ensuring that the viscosity is reasonably adjusted, and the temperature is controlled at 25-30°C. Then, 1.8 parts of photoinitiator (IGM Resins Ai Kemu) are added in sequence by weight. 651), 1.3 parts of additive (BYK-306), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0037] Embodiment 4:

[0038] An EPU glue is made from the following raw materials in parts by weight: 55 parts of modified aliphatic polyurethane acrylate (Wanhua Chemical TDI toluene diisocyanate), 28 parts of monomer (Mitsui Chemicals DPGDA dipropylene glycol diacrylate), 4.7 parts of cyclic molecular compound (Showa Denko α-cyclodextrin), 38 parts of diluent (Mitsubishi Chemical propylene glycol methyl ether), 2 parts of photoinitiator (IGM Resins Ai Kemu 819 bis(difluorophenyl) chloride), 1.4 parts of auxiliary agent (BYK-348 from BYK Germany).

[0039] Preparation method: In a light-shielded reactor, first add in order by weight: 55 parts of modified aliphatic polyurethane acrylate (Wanhua Chemical TDI), 4.7 parts of cyclic molecular compounds (Showa Denko α-cyclodextrin). Ultrasonic dispersion and stirring evenly, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, measure the viscosity by a rotational viscometer to ensure the initial dispersion effect. Next, add 28 parts of monomer (Mitsui Chemicals DPGDA) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30°C. Subsequently, add 38 parts of diluent (Mitsubishi Chemical propylene glycol methyl ether), stir further, keep the speed at 500-800rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and the temperature is controlled at 25-30°C. Then add 2 parts of photoinitiator by weight (IGM Resins Aikemu 819), 1.4 parts of additives (BYK-348 from Germany), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additives are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0040] Embodiment 5:

[0041] An EPU glue is made from the following raw materials in parts by weight: 48 parts of modified aliphatic polyurethane acrylate (Dow Chemical MDI 4,4'-diphenylmethane diisocyanate), 30 parts monomer (Arkema THFA tetrahydrofuran acrylate), 5.0 parts of cyclic molecular compound (Evonik β-cyclodextrin), 41 parts of diluent (Eastman Chemical ethyl acetate), 2 parts of photoinitiator (IGM Resins 184 1-hydroxycyclohexyl phenyl ketone), 1.3 parts of auxiliary agent (BYK BYK-331 from Germany).

[0042] Preparation method: In a light-shielded reaction kettle, first add in order by weight: 48 parts of modified aliphatic polyurethane acrylate (Dow Chemical MDI), 5.0 parts of cyclic molecular compound (Evonik β-cyclodextrin). Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Then, 30 parts of monomer (Arkema) are added by weight. THFA), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30°C. Then, add 41 parts of diluent (Eastman Chemical Eastman Chemical ethyl acetate), further stir, keep the speed at 500-800rpm, set the time for 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C. Then add 2 parts of photoinitiator (IGM Resins Ai Kemu) by weight. 184), 1.3 parts of additive (BYK-331), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing treatment is performed to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0043] Embodiment 6:

[0044] An EPU glue is made from the following raw materials in parts by weight: 44 parts of modified aliphatic polyurethane acrylate (BASF IPDI isophorone diisocyanate), 31 parts of monomer (Sumitomo Chemical TPGDA tripropylene glycol diacrylate), 4.8 parts of cyclic molecular compound (Wacker Chemie γ-cyclodextrin), 41 parts of diluent (Mitsui Chemicals propylene glycol methyl ether), 2 parts of photoinitiator (IGM Resins 1173 phenyl dibenzoyl oxide), 1.2 parts of auxiliary agent (BYK-377 from BYK Germany).

[0045] Preparation method: In a light-shielded reactor, first add in order by weight: 44 parts of modified aliphatic polyurethane acrylate (BASF IPDI), 4.8 parts of cyclic molecular compounds (Wacker Chemie γ-cyclodextrin). Ultrasonic dispersion and stirring evenly, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, measure the viscosity by a rotational viscometer to ensure the initial dispersion effect. Next, add 31 parts of monomer (Sumitomo Chemical TPGDA) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30°C. Subsequently, add 41 parts of diluent (Mitsui Chemicals propylene glycol methyl ether), stir further, keep the speed at 500-800rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and the temperature is controlled at 25-30°C. Then add 2 parts of photoinitiator by weight (IGM Resins 1173), 1.2 parts of additive (BYK-377), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0046] Embodiment 7:

[0047] An EPU glue is made from the following raw materials in parts by weight: 52 parts of modified aliphatic polyurethane acrylate (Wanhua Chemical H6XDI hexahydro-m-xylylene diisocyanate), 33 parts of monomer (Arkema DPGDA dipropylene glycol diacrylate), 5.1 parts of cyclic molecular compound (Showa Denko α-cyclodextrin), 39 parts of diluent (Sumitomo Chemical propylene glycol ethyl ether), 1.7 parts of photoinitiator (IGM Resins Ai Kemu 2959 hydroxycyclohexyl phenyl ketone), 1.3 parts of auxiliary agent (BYK BYK-341 from Germany).

[0048] Preparation method: In a light-shielded reactor, first add 52 parts of modified aliphatic polyurethane acrylate (Wanhua Chemical H6XDI), 5.1 parts of cyclic molecular compound (Showa Denko α-cyclodextrin). Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Then, 33 parts of monomer (Arkema) are added by weight. DPGDA), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30℃. Then, add 39 parts of diluent (Sumitomo Chemical propylene glycol ethyl ether), stir further, keep the speed at 500-800rpm, set the time for 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30℃. Then add 1.7 parts of photoinitiator (IGM Resins Ai Kemu) by weight. 2959), 1.3 parts of additive (BYK-341), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0049] Embodiment 8:

[0050] An EPU glue is made from the following raw materials in parts by weight: 45 parts of modified aliphatic polyurethane acrylate (Covestro N3400 triisocyanate), 34 parts monomer (Ashland THFA tetrahydrofuran acrylate), 5.0 parts of cyclic molecular compound (Wacker Chemie β-cyclodextrin), 43 parts of diluent (Dow Chemical propylene glycol methyl ether acetate), 2.3 parts of photoinitiator (IGM Resins 1173 phenyl dibenzoyl oxide), 1.5 parts of auxiliary agent (BYK-307 from BYK Germany).

[0051] Preparation method: In a light-shielded reactor, first add in order by weight: 45 parts of modified aliphatic polyurethane acrylate (Covestro N3400), 5.0 parts of cyclic molecular compound (Wacker Chemie β-cyclodextrin). Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Then, 34 parts of monomer (Ashland Ashland) are added by weight. THFA), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30°C. Then, add 43 parts of diluent (Dow Chemical Dow Chemical propylene glycol methyl ether acetate), stir further, keep the speed at 500-800rpm, set the time for 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C. Then add 2.3 parts of photoinitiator (IGMResins Aikemu) by weight. 1173), 1.5 parts of additive (BYK-307), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0052] Embodiment 9:

[0053] An EPU glue is made from the following raw materials in parts by weight: 53 parts of modified aliphatic polyurethane acrylate (BASF TDI toluene diisocyanate), 30 parts monomer (Arkema HEMA 2-hydroxyethyl methacrylate), 4.9 parts of cyclic molecular compound (Evonik α-cyclodextrin), 40 parts of diluent (Eastman Chemical ethyl acetate), 1.8 parts of photoinitiator (IGM Resins 819 bis(difluorophenyl) chloride), 1.6 parts of auxiliary agent (BYK-333 from BYK Germany).

[0054] Preparation method: In a light-shielded reactor, first add in order by weight: 53 parts of modified aliphatic polyurethane acrylate (BASF TDI), 4.9 parts of cyclic molecular compound (Evonik α-cyclodextrin). Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. After stirring, the viscosity is measured by a rotational viscometer to ensure the initial dispersion effect. Then, 30 parts of monomer (Arkema) are added by weight. HEMA), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30℃. Then, add 40 parts of diluent (Eastman Chemical Eastman Chemical ethyl acetate), stir further, keep the speed at 500-800rpm, set the time for 5-10 minutes, ensure that the viscosity is properly adjusted, and control the temperature at 25-30℃. Then add 1.8 parts of photoinitiator (IGM Resins Ai Kemu) by weight. 819), 1.6 parts of additives (BYK-333 from Germany), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additives are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0055] Embodiment 10:

[0056] An EPU glue is made of the following raw materials in parts by weight: modified aliphatic polyurethane acrylate 47 (Covestro MDI 4,4'-diphenylmethane diisocyanate), 32 parts of monomer (Sumitomo Chemical PETA pentaacrylate), 4.7 parts of cyclic molecular compound (Mitsui Chemical β-cyclodextrin), 42 parts of diluent (Eastman Chemical propylene glycol methyl ether acetate), 2.2 parts of photoinitiator (IGM Resins 184 1-hydroxycyclohexyl phenyl ketone), 1.3 parts of auxiliary agent (BYK BYK-341 from Germany).

[0057] Preparation method: In a light-shielded reactor, first add in order by weight: 47 parts of modified aliphatic polyurethane acrylate (Covestro MDI), 4.7 parts of cyclic molecular compounds (Mitsui Chemicals β-cyclodextrin). Ultrasonic dispersion and stirring evenly, set the speed to 800-1200rpm, the time to 10-20 minutes, and the temperature to 25-30°C. After stirring, measure the viscosity by a rotational viscometer to ensure the initial dispersion effect. Next, add 32 parts of monomer (Sumitomo Chemical PETA) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the monomer is fully mixed with other components, and keep the temperature at 25-30°C. Subsequently, add 42 parts of diluent (Eastman Chemical Eastman Chemical propylene glycol methyl ether acetate), stir further, keep the speed at 500-800rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and the temperature is controlled at 25-30°C. Then add 2.2 parts of photoinitiator (IGM Resins Ai Kemu) by weight. 184), 1.3 parts of additive (BYK-341), keep the temperature at 25-30°C, stir slowly and evenly, set the speed to 300-500rpm, and the time is 10-20 minutes to ensure that the photoinitiator and the additive are fully mixed with the base material. Vacuum degassing and discharging After completing all the stirring and mixing steps, vacuum degassing is carried out to ensure that the bubbles in the glue are completely discharged. Finally, the EPU glue is obtained by discharging.

[0058] After the above EPU glue is coated and cured into a film, it is cut and pasted on the screen of a folding screen mobile phone, placed in an oven for 72 hours and then taken out for observation. The performance of the mobile phone protective film is shown in Table 1.

[0059] Table 1:

[0060]

[0061] Test standard:

[0062] Shore hardness refers to the international standard ISO7619-1:2010 "Rubber and plastic Shore hardness test method";

[0063] Tensile strength ISO527-1:2012 "Plastics, determination of tensile properties";

[0064] Elongation ISO1184-1983 "Test for tensile properties of plastic films".

[0065] After the EPU glue of the present invention is formed on the release film, the adhesion of the anti-peep and self-repairing coatings is excellent, which improves the performance and durability of the overall film layer. After the EPU glue of the present invention is formed into a film, it can replace the existing release film, so that it is compatible with the unused and untreated high-transparency, low-haze PET base film, and expands the application range of the EPU glue. The present invention adopts modified aliphatic polyurethane acrylate to achieve the high flexibility of the EPU glue, making it more suitable for use in bendable and dynamically used scenarios, such as protective films for folding screens and flexible display devices. The modified polyurethane acrylate in the present invention has good wear resistance, so that the EPU glue can maintain surface integrity for a long time when applied to the protective film, thereby extending the service life of the product. The EPU glue of the present invention, combined with the monomers and photoinitiators prepared in this scheme, can achieve rapid curing in a short time, greatly improve production efficiency, and reduce process time.

[0066] In this scheme, by introducing cyclic molecular compounds, the cyclic molecules can be wrapped or embedded in the main chain or side chain of the modified aliphatic polyurethane acrylate to form a sliding cross-linking structure, which allows the polymer chain to move freely between the cross-linking points. Specifically, cyclodextrin can be used as a molecular sliding bridge to allow the polymer chain segments to slip when subjected to external force, and it is not fixed in a certain position, which helps to effectively disperse local stress under the action of external force and avoid fracture or permanent deformation caused by stress concentration, thereby improving the flexibility and fatigue resistance of the material. Compared with the traditional fixed cross-linking structure, the slip network of this scheme can reorganize the chain segments of the material when it is deformed, so that it can adapt to the ever-changing external force, and is suitable for application scenarios that require repeated bending or stretching. After the stress is eliminated, the slip network can achieve self-repairing function through the rearrangement and recovery of the chain segments, reduce the microscopic damage caused by external forces, and maintain the integrity of the film layer. The slip network structure in this scheme not only improves the mechanical properties of the material, but also improves its wear resistance and ductility, and is suitable for folding screen protective films. The cyclic molecular compound in the present invention provides self-repairing ability, and also enables the EPU glue used in the self-repairing film layer to efficiently and automatically repair fine scratches, and maintain a lasting and smooth appearance.

[0067] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An EPU glue, characterized in that: The composition includes the following weight ratios: The modified aliphatic polyurethane acrylate is prepared by polymerizing at least one of H6XDI hexahydro-m-xylylene diisocyanate, C12-C14 aliphatic carbonate diol, trifunctional aliphatic polyol, isophorone diisocyanate, triisocyanate, toluene diisocyanate and diphenylmethane diisocyanate with the monomers and cyclic molecular compounds to form a slip network polymer, and the molecular chain of the polymer can move between crosslinking points.

2. The method for preparing EPU glue according to claim 1, characterized in that: The cyclic molecular compound is any one of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.

3. The method for preparing EPU glue according to claim 1, characterized in that: The monomer is any one or more of the functional monomer THFA tetrahydrofuran acrylate, the bifunctional monomer TPGDA tripropylene glycol diacrylate, and DPGDA dipropylene glycol diacrylate.

4. The method for preparing EPU glue according to claim 1, characterized in that: The photoinitiator is any one or more of phenyl dibenzoyl oxide, bis difluorophenyl chloride, and toluene diperoxide.

5. The method for preparing EPU glue according to claim 1, characterized in that: The auxiliary agent is composed of any one or more of urethane acrylate, mercaptoacetic acid acrylate, and epoxy acrylate.

6. A method for preparing EPU glue according to claims 1-5, characterized in that: The steps include: (1) Add 20-70 parts of modified aliphatic polyurethane acrylate and 10-30 parts of monomer in a light-shielded reaction kettle in order by weight; stir evenly by ultrasonic dispersion, set the speed to 800-1500 rpm, the time to 5-30 min, and the temperature to 25-35° C.; (2) After ultrasonic dispersion and stirring, add the following in order by weight: 0.5-6 parts of photoinitiator, 0.2-3 parts of auxiliary agent, 10-90 parts of diluent, stir slowly and evenly, set the speed to 300-500 rpm, the time to 10-20 min, and the temperature to 25-35°C; (3) Vacuum degassing by vacuum machine; (4) discharging the material to obtain EPU glue; (5) The obtained EPU glue is stored in an environment shielded from ultraviolet light.

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