A uv-curable bio-based composition and adhesive films, tapes prepared therefrom

Abstract

This invention relates to the field of adhesive technology, disclosing a UV-curable bio-based composition and the adhesive films and tapes prepared therefrom. The invention provides a UV-curable bio-based composition that can be used to manufacture tapes or films. The tapes or films prepared from the composition of this invention have sufficient initial tack before curing, achieving a positioning function before curing. The composition provided by this invention is derived from bio-based materials and can achieve UV curing to form an organic whole, giving the film good mechanical properties and excellent adhesive performance after UV curing, resulting in a bio-based UV adhesive film that can achieve UV-enhanced adhesion. Simultaneously, the composition provided by this invention contains an intrinsically flame-retardant substance, which is obtained through modification with a bio-based derivative. Therefore, this invention ultimately yields a bio-based UV adhesive film that can achieve UV-enhanced adhesion, exhibiting excellent comprehensive performance in use, balancing good mechanical strength and flame retardancy.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to a UV-curable bio-based composition and the adhesive films and tapes prepared therefrom. Background Technology

[0002] UV-cured tapes can be categorized into UV free radical curing systems, UV cationic curing systems, and UV anionic curing systems. Free radical curing tapes cure too quickly, resulting in poor adhesive strength and unsuitability for bonding to opaque surfaces. UV anionic curing tapes promote anionic polymerization between epoxy or unsaturated groups by releasing alkaline molecules, forming a cross-linked network. However, their curing rate is slow at room temperature, requiring additional heat to achieve the desired mechanical strength. UV cationic curing tapes can be used for bonding to opaque surfaces. Their curing speed is easily adjustable and they cure quickly at room temperature, establishing the mechanical strength required for use. Therefore, they can be applied to the acoustic and optical structural bonding of electronic devices. In electronic devices, flame retardancy is a valuable and important property. However, with increasingly stringent environmental requirements, the application of traditional halogen flame retardants is becoming increasingly restricted. Organophosphorus flame retardants have gained widespread attention due to their high flame retardancy and low toxicity. However, in actual production, adding additional flame retardants to the components can reduce the mechanical properties and thermal stability of the resulting films and tapes. Meanwhile, the adhesive used in tapes is usually derived from petroleum-based substances, but the use of petrochemical raw materials will increase carbon emissions in the atmosphere, leading to an increasingly serious greenhouse effect. Moreover, petroleum resources are finite and unsustainable.

[0003] Therefore, it is of great significance to provide a UV-curable bio-based composition with intrinsic flame-retardant properties and the adhesive films and tapes prepared therefrom. Summary of the Invention

[0004] The purpose of this invention is to provide a UV-curable bio-based composition and the adhesive films and tapes prepared therefrom, in order to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A UV-curable bio-based composition comprising the following components: 100-125 parts by weight of a methacrylic acid polymer, 10-200 parts by weight of a bio-based epoxy resin, 0.5-20 parts by weight of a photoacid generator, and 0.15-10 parts by weight of a photosensitizer.

[0007] Furthermore, the UV-curable bio-based composition comprises the following components: by weight, 100 parts of methacrylic polymer, 20-150 parts of bio-based epoxy resin, 2-10 parts of photoacid generator and 0.3-5 parts of photosensitizer.

[0008] Furthermore, the bio-based epoxy resin is an itaconic acid derivative modified epoxy resin.

[0009] In UV tackifying systems, itaconic acid derivative-modified epoxy resin is mixed with polyacrylic acid resin in a mass ratio of 20-150 parts. If the ratio is less than 20 parts, its flame retardancy will not be adequately demonstrated. Because the UV tackifying system needs to balance initial tack before UV exposure and high modulus and high strength after UV exposure, the ratio of itaconic acid derivative-modified epoxy resin to polyacrylic acid resin must be controlled; that is, the itaconic acid derivative-modified epoxy resin in the system should not exceed 150 parts.

[0010] Furthermore, the itaconic acid derivative-modified epoxy resin is prepared according to the following method:

[0011] Alkyl butadiene and benzoyl peroxide were added to an itaconic acid toluene solution and reacted at 120-125℃ for 5-5.5 h to obtain an itaconic acid derivative. The itaconic acid derivative and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide were added to toluene and reacted at 120-125℃ for 10-10.5 h. The mixture was then filtered, washed, and dried to obtain a phosphorus-containing itaconic acid derivative. The phosphorus-containing itaconic acid derivative, tetrabutylammonium bromide, and sodium hydroxide were added to epichlorohydrin and reacted at 100-105℃ for 3-3.5 h. The mixture was then washed, the solvent was removed, and the mixture was dried to obtain an itaconic acid derivative-modified epoxy resin.

[0012] Furthermore, the alkylbutadiene is any one or more of butadiene, methylbutadiene, and dimethylbutadiene.

[0013] Furthermore, the photoacid-generating agent is any one or more of diaryliodomonium salts, triarylthiomonium salts, and aryl diazonium salts.

[0014] Furthermore, the photosensitizer is any one or more of fused cyclic quinones, azo compounds, organosulfur compounds, and halides.

[0015] Furthermore, the methacrylic acid polymer comprises the following components, by mass parts: 30-60 parts of non-functional methacrylic acid monomers, 25-68 parts of bio-based acrylic monomers, 0-15 parts of methacryloyl monomers containing polar functional groups, 0.5-5 parts of functional methacryloyl monomers, 1.5-10 parts of methacryloyl monomers containing epoxy groups, 0.2 parts of initiator, and 150 parts of ethyl acetate; the epoxy value of the methacrylic acid polymer is 0.01-0.1; and the acid value of the methacrylic acid polymer is 5.6 mgKOH / g-56 mgKOH / g.

[0016] By adjusting the structure of polyacrylic acid resin and adding a certain amount of methacrylamide monomers containing epoxy groups, the distribution of itaconic acid derivative-modified epoxy resin and polyacrylic acid resin in the cured system will be more balanced, exhibiting good flame retardant properties.

[0017] Furthermore, the non-functional methacrylic monomer is any one or more of alkyl methacrylate and aryl methacrylate; the bio-based acrylic monomer is any one or more of bio-based isobornyl methacrylate, bio-based isobornyl acrylate, bio-based tridecyl methacrylate, and bio-based heptadecanyl methacrylate; the methacrylamide monomer containing a polar functional group is a methacrylamide monomer containing any one or more of hydroxyl, morpholino, tetrahydrofuran, and amide groups; and the functional methacrylamide monomer is a methacrylamide monomer containing any one or more of carboxyl and acid anhydride groups.

[0018] Furthermore, the methacrylic polymer is prepared according to the following method:

[0019] Non-functional methacrylic acid monomers, bio-based acrylic acid monomers, methacrylamide monomers containing polar functional groups, and an initiator are mixed to obtain a monomer mixture. One-quarter of the monomer mixture by mass is taken, and half the mass of functional methacrylamide monomers are added. After mixing evenly, the mixture is heated to 60-80℃ under a nitrogen atmosphere and reacted for 2-4 hours to obtain a reaction solution. Two-thirds of the remaining monomer mixture by mass, the remaining half mass of functional methacrylamide monomers, and half the mass of methacrylamide monomers containing epoxy groups are mixed and slowly added dropwise to the above reaction solution. The mixture is reacted at 80-120℃ for 1-3 hours. The remaining monomer mixture is added, and the mixture is reacted at 60-80℃ for 1-3 hours. The remaining half mass of methacrylamide monomers containing epoxy groups is added, and the mixture is reacted at 60-80℃ for 0.5-1 hours and kept at this temperature for 1-2 hours to obtain a methacrylic acid polymer.

[0020] Furthermore, the adhesive film consists of a UV-curable bio-based composition and release films covering both sides thereof.

[0021] Furthermore, the tape is composed, from top to bottom, of a release film, a UV-curable bio-based composition, and a PET base film.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0023] (1) This invention provides a UV-curable composition that can be used to manufacture tapes or films. The composition system of this invention contains an acrylic polymer with a designed structure so that the tapes or films prepared by this invention have sufficient initial tack before curing to achieve the positioning function before curing. Furthermore, the synthesized acrylic polymer needs to contain carboxyl groups, anhydride groups, and epoxy groups, which participate in the reaction together when activated by UV cationic oxidation, so that the resin system has a relatively uniform high crosslinking density; after the reaction, it has high structural strength and good adhesion.

[0024] (2) The introduction of bio-based raw materials makes the preparation of films more green and environmentally friendly, which is of great significance for addressing energy issues and sustainable development.

[0025] (3) The present invention designs and synthesizes a bio-based composition containing phosphorus itaconic acid epoxy structure, which has good compatibility and binding with epoxy modified acrylic resin. The introduction of DOPO into the itaconic acid structure makes the cured film have intrinsic halogen-free flame retardant properties. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The raw materials used in the following embodiments are shown in the table below:

[0028]

[0029] Bio-based epoxy resins are prepared as follows:

[0030] Five parts itaconic acid, four parts butadiene, and 0.1 parts BPO were reacted in 20 parts toluene at 120°C for 5 hours to obtain an itaconic acid derivative. One part of the itaconic acid derivative and two parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide were reacted in 2.5 parts toluene at 120°C for 10 hours, followed by filtration, washing, and drying to obtain a phosphorus-containing itaconic acid derivative. One part of the phosphorus-containing itaconic acid derivative was reacted with 10 parts epichlorohydrin at 100°C for 3 hours under the catalysis of 0.05 parts tetrabutylammonium bromide and 20 parts sodium hydroxide, followed by washing, solvent removal, and drying to obtain a bio-based epoxy resin.

[0031] The preparation of methacrylic acid polymers includes the following six synthetic examples:

[0032] Synthesis Example 1: 15 parts MA, 15 parts BA, 68 parts SARBIO6105, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of the mixture was mixed with 0.25 parts AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was mixed with 0.25 parts AA and 0.75 parts GMA, and the mixture was heated to 80°C and added dropwise for 2 hours. Next, the remaining monomer mixture was added dropwise at 60°C for 2 hours. Finally, 0.75 parts GMA were added dropwise while maintaining the temperature, and the addition was completed in 0.5 hours. The mixture was then kept at this temperature for 1 hour to obtain a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 7300 cp.

[0033] Synthesis Example 2: 30 parts MA, 15 parts BA, 45 parts SARBIO6105, 6 parts 2-HEA, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of this mixture was mixed with 1.25 parts AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was mixed with 1.25 parts AA and 0.75 parts GMA, and the mixture was heated to 80°C and added dropwise for 2 hours. Next, the remaining monomer mixture was added dropwise at 60°C for 2 hours. Finally, 0.75 parts GMA were added dropwise while maintaining the temperature, and the addition was completed in 0.5 hours. The mixture was then kept at this temperature for 1 hour to obtain a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 8900 cp.

[0034] Synthesis Example 3: 50 parts MA, 10 parts BA, 25 parts SARBIO6105, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of this mixture was mixed with 0.25 parts AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was mixed with 0.25 parts AA and 2.25 parts GMA, and the mixture was heated to 80°C and added dropwise for 2 hours. Next, the remaining monomer mixture was added dropwise at 60°C for 2 hours. Finally, 2.25 parts GMA were added dropwise while maintaining the temperature, and the mixture was kept at this temperature for 1 hour. This yielded a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 8100 cp.

[0035] Synthesis Example 4: 30 parts MA, 15 parts BA, 35 parts SARBIO6105, 5 parts ACM, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of the mixture was mixed with 2.5 parts AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was mixed with 2.5 parts AA and 5 parts GMA, and the mixture was heated to 80°C and added dropwise for 2 hours. Next, the remaining monomer mixture was added dropwise at 60°C for 2 hours. Finally, 5 parts GMA were added dropwise while maintaining the temperature, and the mixture was kept at this temperature for 1 hour to obtain a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 9100 cp.

[0036] Synthesis Example 5: 10 parts MA, 20 parts BA, 47 parts SARBIO6105, 15 parts 2-HEA, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of the mixture was mixed with 1 part AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was mixed with 1 part AA and 3 parts GMA, and the mixture was heated to 80°C and reacted dropwise for 2 hours. Next, the remaining monomer mixture was reacted dropwise at 60°C for 2 hours. Finally, 3 parts GMA were added dropwise while maintaining the temperature, and the mixture was kept at this temperature for 1 hour to obtain a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 5400 cp.

[0037] Synthesis Example 6: 30 parts MA, 20 parts BA, 40 parts SARBIO6105, 8 parts ACM, 0.2 parts AIBN, and 150 parts EA were mixed in a glass bottle to obtain a monomer mixture. One-quarter of the mixture was mixed with 1 part AA, nitrogen gas was purged for two minutes to remove oxygen, and the mixture was sealed. The reaction bottle was placed in a polymerization apparatus and polymerized at 60°C for 3 hours. Then, two-thirds of the remaining monomer mixture was added to 1 part AA, the temperature was raised to 80°C, and the mixture was added dropwise for 2 hours. The remaining monomer mixture was then added dropwise at 60°C for 2 hours and kept at that temperature for 1 hour to obtain a solvent-based methacrylic acid polymer with a solid content of 40% and a viscosity of 6200 cp.

[0038] Example 1: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 1, 20 parts of phosphorus-containing itaconic acid epoxy resin, 0.5 parts of triarylhexafluoroantimony thioonium salt, and 0.15 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0039] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0040] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0041] Example 2: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 2, 60 parts of phosphorus-containing itaconic acid epoxy resin, 5 parts of triarylhexafluoroantimony sulfonium salt, and 2 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0042] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0043] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0044] Example 3: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 3, 150 parts of phosphorus-containing itaconic acid epoxy resin, 20 parts of triarylhexafluoroantimony sulfonium salt, and 10 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0045] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0046] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0047] Example 4: 100 parts of the methacrylic polymer (40% solid content) of Synthesis Example 4, 100 parts of phosphorus-containing itaconic acid epoxy resin, 10 parts of triarylhexafluoroantimony sulfonium salt, and 3 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0048] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0049] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0050] Example 5: 100 parts of the methacrylic polymer of Synthesis Example 5 (40% solid content), 80 parts of phosphorus-containing itaconic acid epoxy resin, 1 part of triarylhexafluoroantimony sulfonium salt, and 0.5 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0051] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0052] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0053] Comparative Example 1: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 6, 60 parts of phosphorus-containing itaconic acid epoxy resin, 5 parts of triarylhexafluoroantimony sulfonium salt, and 2 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0054] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0055] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0056] Comparative Example 2: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 2, 10 parts of phosphorus-containing itaconic acid epoxy resin, 0.5 parts of triarylhexafluoroantimony sulfonium salt, and 0.15 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0057] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0058] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0059] Comparative Example 3: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 2, 200 parts of phosphorus-containing itaconic acid epoxy resin, 20 parts of triarylhexafluoroantimony sulfonium salt, and 10 parts of ITX were mixed evenly to obtain a UV-curable bio-based composition.

[0060] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0061] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0062] Comparative Example 4: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 2, 60 parts of EPON 828, 5 parts of triarylhexafluoroantimony sulfonium salt, and 2 parts of ITX were mixed evenly to obtain a UV-curable composition.

[0063] The UV-curable composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0064] The UV-curable composition was coated onto 50-micron PET and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm release film was applied to the surface of the film for subsequent peel force measurement.

[0065] Comparative Example 5: 100 parts of the methacrylic polymer (40% solid content) of Synthetic Example 2, 60 parts of phosphorus-containing itaconic acid epoxy resin, 5 parts of U-CAT 5002, 2 parts of ITX, and 40 parts of PETMP were mixed evenly to obtain a UV-curable bio-based composition.

[0066] A UV-curable bio-based composition is coated onto a release film with a thickness of 10-75 μm and dried at 110°C for 3 min to obtain a dry film thickness of 50 μm. After drying, another release film with a thickness of 30 μm is applied to the surface of the adhesive film to obtain the adhesive film.

[0067] A UV-curable bio-based composition was coated onto a 50-micron PET film and dried at 110°C for 3 minutes to obtain a dry film thickness of 50 μm. After drying, a 30 μm thick release film was applied to the film surface for subsequent peel force measurement.

[0068] Experiment: The products prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were subjected to performance tests, and the data obtained are shown below:

[0069] The initial peel strength of the tape was tested according to ASTM D3330, as follows: Before testing, the stainless steel plate was wiped three times with ethanol. A 1cm piece of single-sided tape with a 50-micron PET backing was cut, the release film was removed, and the tape was applied to a stainless steel plate and rolled twice with a force of 2kg. Before the peel test, the tape was placed in a controlled environment chamber (23℃ / 50% relative humidity) for 30 minutes and tested using an Instron tensile testing machine at a speed of 300mm / min. Each test was repeated three times, and the average value was taken. The unit is N / mm.

[0070] The UV peel strength of the tape was tested according to ASTM D3330, as follows:

[0071] The stainless steel plate was wiped three times with ethanol before testing. Single-sided adhesive tape with 50-micron PET as the backing substrate was cut into 1cm pieces and irradiated with a UV (Fusion D lamp, UVA approximately 1500mJ / cm). 2 Afterward, remove the release film and attach it to a stainless steel plate, applying a force of 3 kg for 10 seconds. Before the peel test, place the adhesive in a controlled environment chamber (23°C / 50% relative humidity) for 24 hours, and test it using an Instron tensile testing machine at a speed of 300 mm / min. Each test is repeated three times, and the average value is taken, in N / mm.

[0072] The pull-out force was tested as follows:

[0073] Before testing, wipe the stainless steel T-shaped fixture (1 inch x 1 inch) three times with ethanol. Cut the adhesive film sample with release film on both sides into 1 inch x 1 inch pieces, peel off one side of the release film, and attach it to a stainless steel T-shaped fixture. Peel off the other side of the release film and irradiate with a UV (Fusion D lamp, UVA approximately 1500 mJ / cm²). 2), attach another stainless steel T-shaped fixture to the other side of the adhesive surface. Place the test sample in a controlled environment chamber (23℃ / 50% relative humidity) for post-curing for about 1 day before testing. Alternatively, place the prepared sample in an 80℃ oven to accelerate curing for 1 hour, remove it from the oven, and cool the test sample to room temperature in a controlled environment chamber (23℃ / 50% relative humidity) before measurement.

[0074] Pull-out force was tested using an Instron tensile tester at a speed of 10.0 mm / min. Each test was repeated three times, and the average value was taken. The unit is MPa.

[0075] The flame retardancy of the film was characterized by the limiting oxygen index (LOI), which was determined using a limiting oxygen index meter according to the ASTM D2863-97 test standard.

[0076] The test results are shown in the table below:

[0077]

[0078]

[0079] Conclusion: The data in the table show that in Comparative Example 1, the acrylic resin was not modified with epoxy groups, resulting in poor compatibility with the phosphorus-containing itaconic acid epoxy, and consequently, poor adhesive strength and flame retardancy of the cured film. In Comparative Example 2, the phosphorus-containing itaconic acid epoxy content was too low, resulting in poor adhesive strength and flame retardancy of the cured film. In Comparative Example 3, the proportion of phosphorus-containing itaconic acid epoxy was too high, resulting in low initial tack of the film before UV exposure, affecting its overall performance. Comparative Example 4 lacks flame retardant properties. Comparative Example 5 used a photoalkali system, which reduced both its adhesive performance and flame retardancy to some extent. Examples 1 to 5 prepared according to the method provided by this invention exhibit good flame retardancy and excellent mechanical properties.

[0080] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A UV-curable bio-based composition, characterized in that: The UV-curable bio-based composition comprises the following components: by weight, 100-125 parts of methacrylic acid polymer, 20-150 parts of bio-based epoxy resin, 0.5-20 parts of photoacid generator and 0.15-10 parts of photosensitizer; The bio-based epoxy resin is an itaconic acid derivative modified epoxy resin, which is prepared by first reacting a butadiene compound with itaconic acid to obtain an itaconic acid derivative; the butadiene compound is any one or more of butadiene, methylbutadiene, and dimethylbutadiene; then 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is grafted onto the itaconic acid derivative to obtain a phosphorus-containing itaconic acid derivative; finally, the phosphorus-containing itaconic acid derivative is reacted with epichlorohydrin to prepare the bio-based epoxy resin. The acid value of the methacrylic acid polymer is 5.6 mg KOH / g - 56 mg KOH / g; The methacrylic acid polymer comprises the following components by weight: 30-60 parts of non-functional methacrylic acid monomers, 25-68 parts of bio-based acrylic monomers, 0-15 parts of methacryloyl monomers containing polar functional groups, 0.5-5 parts of functional methacryloyl monomers, 1.5-10 parts of methacryloyl monomers containing epoxy groups, 0.2 parts of initiator, and 150 parts of ethyl acetate; the epoxy value of the methacrylic acid polymer is 0.01-0.

1. The non-functional methacrylic acid monomers are any one or more of alkyl methacrylates and aryl methacrylates; the bio-based acrylic monomers are any one or more of bio-based isobornyl methacrylate, bio-based isobornyl acrylate, bio-based tridecyl methacrylate, and bio-based heptadecanyl methacrylate; the methacrylamide monomers containing polar functional groups are methacrylamide monomers containing any one or more of hydroxyl, morpholino, tetrahydrofuran, and amide groups; the functional methacrylamide monomers are methacrylamide monomers containing any one or more of carboxyl and acid anhydride groups. The methacrylic acid polymer is prepared according to the following method: Non-functional methacrylic acid monomers, bio-based acrylic acid monomers, methacrylamide monomers containing polar functional groups, and an initiator are mixed to obtain a monomer mixture. One-quarter of the monomer mixture by mass is taken, and half the mass of functional methacrylamide monomers are added. After mixing evenly, the mixture is heated to 60-80℃ under a nitrogen atmosphere and reacted for 2-4 hours to obtain a reaction solution. Two-thirds of the remaining monomer mixture by mass, the remaining half mass of functional methacrylamide monomers, and half the mass of methacrylamide monomers containing epoxy groups are mixed and slowly added dropwise to the above reaction solution. The mixture is reacted at 80-120℃ for 1-3 hours. The remaining monomer mixture is added, and the mixture is reacted at 60-80℃ for 1-3 hours. The remaining half mass of methacrylamide monomers containing epoxy groups is added, and the mixture is reacted at 60-80℃ for 0.5-1 hours and kept at this temperature for 1-2 hours to obtain a methacrylic acid polymer.

2. The UV-curable bio-based composition according to claim 1, characterized in that: The bio-based epoxy resin is prepared according to the following method: (1) Butadiene compound and benzoyl peroxide were added to a toluene solution of itaconic acid and reacted at 120-125℃ for 5-5.5 h to obtain itaconic acid derivative; (2) Add itaconic acid derivative and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to toluene, react at 120-125℃ for 10-10.5h, filter, wash and dry to obtain phosphorus-containing itaconic acid derivative. (3) Add phosphorus-containing itaconic acid derivative, tetrabutylammonium bromide and sodium hydroxide to epichlorohydrin, react at 100-105℃ for 3-3.5h, wash, remove solvent, dry, and obtain bio-based epoxy resin.

3. The UV-curable bio-based composition according to claim 1, characterized in that: The photoacid-generating agent is any one or more of diaryliodomonium salts, triarylthiomonium salts, and aryl diazonium salts; the photosensitizer is any one or more of fused-ring quinones, azo compounds, organosulfur compounds, and halides.

4. The adhesive film prepared from a UV-curable bio-based composition according to any one of claims 1-3, characterized in that: The film consists of a UV-curable bio-based composition and release films covering both sides thereof.

5. The tape prepared from a UV-curable bio-based composition according to any one of claims 1-3, characterized in that: The tape consists of, from top to bottom, a release film, a UV-curable bio-based composition, and a PET base film.

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