Preparation method of ultraviolet light and heat dual-curing pressure-sensitive adhesive

Abstract

The invention discloses a preparation method of an ultraviolet light and heat dual-curing pressure-sensitive adhesive, and relates to the technical field of phase change materials, the method combines the advantages of ultraviolet light curing and heat curing, and realizes efficient curing of the pressure-sensitive adhesive by optimizing a raw material formula and a curing process. Specifically, key components such as dimer acid modified epoxy resin and inorganic filler (such as silica powder) are introduced, so that the adhesion property, the electrical insulation property and the thermal conductivity of the pressure-sensitive adhesive are remarkably improved. Compared with the prior art, the pressure-sensitive adhesive prepared by the invention has the characteristics of high curing efficiency, strong adhesive power, excellent electrical insulating property, excellent thermal conductivity and the like, is particularly suitable for the fields of high-performance PET pressure-sensitive adhesive tapes and the like, and meets the requirements of high performance and multi-functionalization of the pressure-sensitive adhesive.

Description

Technical Field

[0001] The present invention relates to the technical field of phase change materials, and specifically to a preparation method of an ultraviolet-light and heat dual-curing pressure-sensitive adhesive. Background Art

[0002] As an important adhesive material, pressure-sensitive adhesives are widely used in many fields such as electronics, automobiles, and medical treatment. However, traditional pressure-sensitive adhesive technologies have many limitations and are difficult to meet the growing high-performance requirements.

[0003] On the one hand, the curing efficiency of traditional pressure-sensitive adhesives is low, and the curing process takes a long time, which is not conducive to large-scale continuous production. On the other hand, there are also deficiencies in the adhesion performance, electrical insulation, and thermal conductivity of traditional pressure-sensitive adhesives. For example, some pressure-sensitive adhesives have large internal stresses after curing, which easily leads to peeling between the adhesive layer and the substrate, affecting the bonding effect; at the same time, the electrical insulation and thermal conductivity of traditional pressure-sensitive adhesives are also difficult to meet the requirements of some special application scenarios.

[0004] At present, a single curing method (such as only using ultraviolet light curing or thermal curing) has been difficult to meet the preparation requirements of high-performance pressure-sensitive adhesives. Although ultraviolet light curing has the advantages of fast curing speed and high efficiency, its curing effect may be limited in some heat-sensitive materials or scenarios that require deep curing. And the thermal curing method may have problems such as slow curing speed and high energy consumption.

[0005] In view of the above problems, the present invention aims to provide a new preparation method of an ultraviolet-light and heat dual-curing pressure-sensitive adhesive. By combining the advantages of ultraviolet light curing and thermal curing, the present invention aims to achieve efficient curing of the pressure-sensitive adhesive while improving the adhesion performance, electrical insulation, and thermal conductivity of the pressure-sensitive adhesive. Specifically, the present invention optimizes the raw material formula, introduces key components such as dimer acid-modified epoxy resin and inorganic fillers (such as silica powder), and adopts an ultraviolet-light and heat dual-curing process, aiming to prepare a pressure-sensitive adhesive with high adhesion, excellent electrical insulation, and thermal conductivity to meet the requirements of high-performance PET pressure-sensitive tapes and other fields. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a preparation method of an ultraviolet-light and heat dual-curing pressure-sensitive adhesive, which solves the problems mentioned in the above background art.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions: A preparation method of an ultraviolet-light and heat dual-curing pressure-sensitive adhesive, including the following steps:

[0008] S1. Put polyacrylate, part of toluene, and ethyl acetate into a four-necked reaction flask, and set the external temperature to 82°C;

[0009] S2. When the temperature of the material in the bottle rises to 79 °C, the BPO solution dissolved in the remaining toluene is evenly dropped into the reaction bottle within 2 hours;

[0010] S3. Keep the temperature for reaction for 2 hours;

[0011] S4. Put the dimer acid-modified epoxy resin and polyether polyol into the reaction bottle and stir rapidly for 30 minutes;

[0012] S5. Slowly add the inorganic filler to the reaction bottle in batches;

[0013] S6. After stirring and dispersing for 60 minutes, add the cationic photoinitiator and coat and use it under yellow light;

[0014] S7. Carry out UV radiation on the coated tape, with a radiation dose of 250 mJ / cm², using a 365 nm LED lamp, and the finished ultraviolet and thermal dual-curing pressure-sensitive adhesive can be obtained.

[0015] Furthermore, the weight percentage content of each component of the raw materials of the ultraviolet and thermal dual-curing pressure-sensitive adhesive is: polyacrylate 20 - 40%, toluene 10 - 40%, ethyl acetate 0 - 30%, dimer acid-modified epoxy resin 30 - 80%, polyether polyol 0 - 15%, inorganic filler 5 - 30%, cationic photoinitiator 0 - 5%.

[0016] Furthermore, the monomer composition weight of the polyacrylate is: butyl acrylate 20 - 60%, methyl acrylate 20 - 60%, isooctyl acrylate 0 - 20%, acrylic acid 0 - 10%, 2-hydroxyethyl acrylate 0 - 4%, allyl glycidyl ether 0.5 - 10%.

[0017] Furthermore, the epoxy value of the dimer acid-modified epoxy resin is 0.1 - 0.4%.

[0018] Furthermore, the inorganic filler is silica powder with a particle size of 5000 - 10000 mesh.

[0019] Furthermore, the cationic photoinitiator is an iodonium salt photoinitiator.

[0020] Furthermore, the prepared ultraviolet and thermal dual-curing pressure-sensitive adhesive is applied to PET pressure-sensitive tape.

[0021] The present invention provides a preparation method of an ultraviolet and thermal dual-curing pressure-sensitive adhesive. Compared with the prior art, it has the following beneficial effects:

[0022] 1. The dimer acid-modified epoxy resin has excellent cohesive strength and good compatibility with the polyacrylate resin, improving the shear resistance and insulation performance of the adhesive.

[0023] 2. Use inorganic filler (silica powder) as the filler to reduce the curing internal stress, improve the adhesion between the adhesive layer and the PET substrate, and enhance the overall thermal conductivity and electrical insulation of the material.

[0024] 3. Allyl glycidyl ether monomer.

[0025] 4. Polyacrylate gives the adhesive layer a relatively high initial adhesion, thus improving the wettability of the adherend surface and at the same time reducing the internal stress caused by the curing of the adhesive layer; the glycidyl ether group in the polyacrylate structure participates in the UV cationic curing to improve the cohesive force of the adhesive layer. Detailed implementation manners

[0026] Next, the technical solutions of the present invention will be described in detail through specific examples. However, it should be clearly stated that these examples are for illustrative purposes only and are not construed as limiting the scope of the present invention.

[0027] Example 1

[0028] The weight percentage content of each component of the raw materials of the ultraviolet and thermal dual-curing pressure-sensitive adhesive is as follows:

[0029] Polyacrylate: 20%

[0030] Toluene: 30%

[0031] Ethyl acetate: 10%

[0032] Dimer acid-modified epoxy resin (epoxy equivalent, 650 g / mol): 26%

[0033] Inorganic filler (silica powder): 10%

[0034] Polyether polyol: 3%

[0035] Cationic photoinitiator: 1%

[0036] Among them, the weight percentage of the monomer composition of the polyacrylate is as follows:

[0037] Butyl acrylate: 42%

[0038] Methyl acrylate: 45%

[0039] Isooctyl acrylate: 5%

[0040] Acrylic acid: 3%

[0041] 2-Hydroxyethyl acrylate: 2%

[0042] Allyl glycidyl ether: 3%

[0043] The epoxy value of bisphenol A epoxy resin is 0.1 - 1.0%

[0044] Inorganic filler: silica powder, particle size of 8000 mesh.

[0045] The cationic photoinitiator is: iodonium salt photoinitiator

[0046] The preparation method of the above pressure-sensitive adhesive includes the following steps:

[0047] S1. Put isooctyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, acrylic acid, allyl glycidyl ether, part of toluene, and ethyl acetate into a four-necked reaction flask, and set the external temperature to 82 °C;

[0048] S2. When the temperature of the materials in the flask rises to 79 °C, slowly drop the BPO solution dissolved in the remaining toluene into the reaction flask evenly within 2 hours;

[0049] S3. Keep the temperature for reaction for 2 hours;

[0050] S4. Put the modified epoxy resin and polyether polyol into the reaction flask and stir rapidly for 30 minutes;

[0051] S5. Slowly add the inorganic filler (silica powder) into the reaction flask in batches;

[0052] S6. After stirring and dispersing for 60 minutes, coat and use it under yellow light. The PET substrate (0.05 mm thick, corona-treated), the dry adhesive thickness is 0.03 mm;

[0053] S7. Carry out UV radiation on the coated tape: the radiation dose is 250 mJ / cm², and use a 365 nm LED lamp to obtain the finished product of the ultraviolet and thermal dual-curing pressure-sensitive adhesive, and this ultraviolet and thermal dual-curing pressure-sensitive adhesive is applied to the PET pressure-sensitive tape.

[0054] Example 2

[0055] The weight percentage content of each component of the ultraviolet and thermal dual-curing pressure-sensitive adhesive raw material is as follows:

[0056] Polyacrylate: 15%

[0057] Toluene: 30%

[0058] Ethyl acetate: 10%

[0059] Dimer acid modified epoxy resin (epoxy equivalent: 650 g / mol): 31%

[0060] Inorganic filler (silica powder): 10%

[0061] Polyether polyol: 3%

[0062] Cationic photoinitiator: 1%

[0063] Among them, the monomer composition weights of polyacrylate are respectively:

[0064] Butyl acrylate: 25%

[0065] Methyl acrylate, 67%

[0066] 2-Ethylhexyl acrylate: 0%

[0067] Acrylic acid: 3%

[0068] 2-Hydroxyethyl acrylate: 2%

[0069] Allyl glycidyl ether: 3%

[0070] The epoxy value of bisphenol A epoxy resin is 0.1 - 1.0%

[0071] Inorganic filler: silica powder, particle size of 8000 mesh.

[0072] The cationic photoinitiator is: iodonium salt photoinitiator

[0073] The preparation method of the above pressure-sensitive tape includes the following steps:

[0074] S1. Put 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, acrylic acid, allyl glycidyl ether, part of toluene, and ethyl acetate into a four-necked reaction flask, and set the external temperature to 82°C;

[0075] S2. When the temperature of the materials in the flask rises to 79°C, drop the BPO solution dissolved in the remaining toluene into the reaction flask evenly within 2 hours;

[0076] S3. Keep the temperature for reaction for 2 hours;

[0077] S4. Put the modified epoxy resin and polyether polyol into the reaction flask and stir rapidly for 30 minutes;

[0078] S5. Slowly add the inorganic filler (silica powder) into the reaction flask in batches;

[0079] S6. After stirring and dispersing for 60 minutes, apply it under yellow light. The PET substrate (0.05 mm thick, corona-treated), and the dry adhesive thickness is 0.03 mm;

[0080] S7. Carry out UV radiation on the coated tape: the radiation dose is 250 mJ / cm², and use a 365 nm LED lamp to obtain the finished product of the ultraviolet and thermal dual-curing pressure-sensitive adhesive, and this ultraviolet and thermal dual-curing pressure-sensitive adhesive is applied to the PET pressure-sensitive tape.

[0081] Example 3

[0082] The weight percentage content of each component of the ultraviolet and thermal dual-curing pressure-sensitive adhesive raw material is:

[0083] Polyacrylate: 15%

[0084] Toluene: 30%

[0085] Ethyl acetate: 10%

[0086] Dimer acid modified epoxy resin (epoxy equivalent, 650 g / mol): 31%

[0087] Inorganic filler (silica powder): 10%

[0088] Polyether polyol: 3%

[0089] Cationic photoinitiator: 1%

[0090] Among them, the monomer composition weights of the polyacrylate are respectively:

[0091] Butyl acrylate: 25%

[0092] Methyl acrylate, 67%

[0093] Isooctyl acrylate: 0%

[0094] Acrylic acid: 3%

[0095] 2-Hydroxyethyl acrylate: 2%

[0096] Allyl glycidyl ether: 3%

[0097] The epoxy value of bisphenol A epoxy resin is 0.1 - 1.0%

[0098] Inorganic filler: silica powder, particle size of 8000 mesh.

[0099] The cationic photoinitiator is: iodonium salt photoinitiator

[0100] The preparation method of the above pressure-sensitive adhesive tape includes the following steps:

[0101] S1. Put isooctyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, acrylic acid, allyl glycidyl ether, part of toluene, and ethyl acetate into a four-necked reaction flask, and set the external temperature to 82 °C;

[0102] S2. When the temperature of the materials in the flask rises to 79 °C, uniformly drop the BPO solution dissolved in the remaining toluene into the reaction flask within 2 hours;

[0103] S3. Keep the temperature for reaction for 2 hours;

[0104] S4. Put the modified epoxy resin and polyether polyol into the reaction flask and stir rapidly for 30 minutes;

[0105] S5. Slowly add the inorganic filler (silica powder) into the reaction flask in batches;

[0106] S6. After stirring and dispersing for 60 minutes, it is used for coating under yellow light. The PET substrate (0.05 mm thick, corona-treated), the dry adhesive thickness is 0.03 mm;

[0107] S7. The coated tape is subjected to UV radiation: the radiation dose is 250 mJ / cm², and an LED lamp with a wavelength of 365 nm is used to obtain the finished product of the ultraviolet and thermal dual-curing pressure-sensitive adhesive. This ultraviolet and thermal dual-curing pressure-sensitive adhesive is applied to the PET pressure-sensitive tape.

[0108] The finished products of the above three examples are tested for various performance indicators according to the corresponding experimental standards. The test results are shown in the following table:

[0109]

[0110] Through the above experiments, it can be found that by adjusting the proportion of acrylate monomers and the weight percentage of epoxy resin, the peeling strength and shear resistance of the tape can be adjusted.

Claims

1. Preparation method of ultraviolet and thermal dual-curing pressure-sensitive adhesive, characterized in that, It includes the following steps: S1. Put polyacrylate, partial toluene and ethyl acetate into a four-neck reaction flask, and set the external temperature to 82 °C; S2. When the temperature of the materials in the flask rises to 79 °C, slowly drop the BPO solution dissolved in the remaining toluene into the reaction flask evenly within 2 hours; S3. Keep the temperature for reaction for 2 hours; S4. Put the dimer acid-modified epoxy resin and polyether polyol into the reaction flask and stir rapidly for 30 minutes; S5. Slowly add the inorganic filler into the reaction flask in batches; S6. After stirring and dispersing for 60 minutes, add the cationic photoinitiator and coat it under yellow light for use; S7. Carry out UV radiation on the coated tape, with a radiation dose of 250 mJ / cm², and use an LED lamp with a wavelength of 365 nm to obtain the finished product of the ultraviolet and thermal dual-curing pressure-sensitive adhesive.

2. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to claim 1, wherein The weight percentage content of each component of the raw materials of the ultraviolet and thermal dual-curing pressure-sensitive adhesive is as follows: polyacrylate 20-40%, toluene 10-40%, ethyl acetate 0-30%, dimer acid-modified epoxy resin 30-80%, polyether polyol 0-15%, inorganic filler 5-30%, cationic photoinitiator 0-5%.

3. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to claim 1 or 2, characterized in that, The monomer composition weight of the polyacrylate is 20-60% butyl acrylate, 20-60% methyl acrylate, 0-20% isooctyl acrylate, 0-10% acrylic acid, 0-4% hydroxyethyl acrylate, 0.5-10% allyl glycidyl ether.

4. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to claim 1 or 2, characterized in that, The epoxy value of the dimer acid-modified epoxy resin is 0.1-0.4%.

5. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to claim 1 or 2, characterized in that, The inorganic filler is silicon micropowder with a particle size of 5000-10000 mesh.

6. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to claim 1 or 2, characterized in that The cationic photoinitiator is an iodonium salt photoinitiator.

7. The preparation method of the ultraviolet and thermal dual-curing pressure-sensitive adhesive according to any one of claims 1-6, characterized in that The prepared ultraviolet and thermal dual-curing pressure-sensitive adhesive is applied to PET pressure-sensitive tape.

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