Bio-based polyurethane acrylic pressure sensitive adhesive and method of making same
By constructing a microphase separation structure for bio-based polyurethane acrylic pressure-sensitive adhesive, the problem of low cohesive energy in bio-based acrylic pressure-sensitive adhesive was solved, achieving high cohesive energy, strong shear strength, and good wettability, thereby improving the bonding strength.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUZHOU HI TECH ELECTRONICS CO LTD
- Filing Date
- 2023-10-26
- Publication Date
- 2026-06-12
AI Technical Summary
Existing bio-based acrylic pressure-sensitive adhesives suffer from low cohesive energy, insufficient wettability of the substrate, and inadequate adhesive strength. Furthermore, modifications to traditional crosslinking agents can lead to a decline in performance.
A bio-based polyurethane acrylic pressure-sensitive adhesive was prepared by reacting acrylate prepolymer with isocyanate, catalyst, and diamine to construct a microphase separation structure with acrylate as soft segments and urethane groups and urea bonds as hard segments, thereby achieving physical crosslinking and replacing traditional chemical crosslinking.
It improves the cohesive energy, shear strength, and surface polarity of the pressure-sensitive adhesive, thereby enhancing the bonding strength and wettability to meet market demands.
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Figure BDA0004515129670000111
Abstract
Description
Technical Field
[0001] This invention relates to the field of bio-based pressure-sensitive adhesive technology, and in particular to a bio-based polyurethane acrylic pressure-sensitive adhesive and its preparation method. Background Technology
[0002] Petroleum, as a mineral resource, can be refined into various hydrocarbons through different refining methods, resulting in a wide variety of products. However, with global oil reserves dwindling, there is a growing emphasis on the development of new materials, and the market is increasingly calling for new products that can replace traditional petroleum-based materials. Acrylic pressure-sensitive adhesives, as a widely used material applicable to all aspects of life, currently only have a few bio-based acrylic pressure-sensitive adhesives available from Toyo Corporation of Japan, and their performance is far inferior to traditional petroleum-based acrylic pressure-sensitive adhesives. Therefore, the market potential of bio-based acrylic pressure-sensitive adhesives is enormous and has high development value.
[0003] With the development of technology, more and more bio-based acrylic monomers are available on the market, such as lauryl acrylate, isobornyl acrylate, and tetrahydrofurfuryl acrylate. However, due to their excessively long side groups, these materials create severe steric hindrance within the chain segments, reducing both the molecular weight and the cohesive energy of the polymer. This results in pressure-sensitive adhesives prepared from these materials having very low cohesive strength, failing to meet market demands. While adding crosslinking agents or using rigid bio-based acrylic monomers can increase cohesive energy, it can also lead to poorer wettability and adhesion strength of the substrate.
[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0005] The purpose of this invention is to provide a bio-based polyurethane acrylic pressure-sensitive adhesive, which has the advantages of good wettability, high cohesive energy, good wettability to the substrate, and high adhesive strength.
[0006] To achieve the above objectives, embodiments of the present invention provide a bio-based polyurethane acrylic pressure-sensitive adhesive, comprising the following raw material components by mass percentage: 70%-80% acrylate prepolymer, 1%-4% isocyanate, 0.1%-0.3% catalyst, 0.5%-1% diamine, and 15%-25% pressure-sensitive adhesive solvent;
[0007] The acrylate prepolymer comprises, by mass parts, the following raw material components: 2-6 parts of hydroxyl-containing acrylic monomer, 55-75 parts of bio-based acrylic monomer, 0.4-1 parts of initiator, and 30-40 parts of modified solvent.
[0008] In one or more embodiments of the present invention, the bio-based acrylic monomer is at least one selected from isoborneol acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate, tridecanol acrylate, isoborneol methacrylate, and lauryl methacrylate; and / or,
[0009] The hydroxyl-containing acrylic monomer is hydroxyethyl acrylate.
[0010] In one or more embodiments of the present invention, the initiator is at least one of azobisisobutyronitrile and dimethyl azobisisobutyrate.
[0011] In one or more embodiments of the present invention, the diamine is at least one of hydrazine hydrate, ethylenediamine, hexamethylenediamine, and isophoronediamine.
[0012] In one or more embodiments of the present invention, the isocyanate is at least one selected from isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.
[0013] In one or more embodiments of the present invention, the catalyst is at least one of bismuth neodecanoate and stannous octoate.
[0014] Embodiments of the present invention provide a method for preparing the bio-based polyurethane acrylic pressure-sensitive adhesive as described above, comprising the following steps:
[0015] Acrylate prepolymer was prepared;
[0016] The acrylate prepolymer is mixed with isocyanate and reacted to obtain an intermediate product;
[0017] The intermediate product was mixed with a diamine and reacted. A solvent was added to obtain a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic acid as the soft segment and urethane and urea groups as the hard segments.
[0018] In one or more embodiments of the present invention, the step of preparing the acrylate prepolymer includes:
[0019] Mix 2-6 parts of hydroxyl-containing acrylic monomer, 30-40 parts of bio-based acrylic monomer, 0.2-0.5 parts of initiator and 30-40 parts of modified solvent, and stir at 75-80℃ for 30-60 minutes.
[0020] Add 25-35 parts of bio-based acrylic acid and 0.2-0.5 parts of initiator dropwise to the above system, with a dropwise addition time of less than 1 hour. After the dropwise addition is complete, stir the entire mixed reaction system at a temperature of 75-85℃ for 1-2 hours.
[0021] In one or more embodiments of the present invention, the step of mixing and reacting the acrylate prepolymer with the isocyanate specifically includes:
[0022] The acrylate prepolymer, isocyanate and catalyst are mixed at 60-70℃ and stirred at 80-85℃ for 2-3 hours.
[0023] In one or more embodiments of the present invention, the step of adding a diamine to the intermediate product includes:
[0024] Add a diamine to the intermediate product and react for 30-60 minutes, then add the pressure-sensitive adhesive solvent.
[0025] Compared with the prior art, the bio-based polyurethane acrylic pressure-sensitive adhesive according to the embodiments of the present invention can improve the cohesive energy of the pressure-sensitive adhesive, increase the shear strength, and also enhance the surface polarity of the adhesive film, thereby improving the adhesive strength of the pressure-sensitive adhesive. Detailed Implementation
[0026] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0027] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0028] According to a preferred embodiment of the present invention, a bio-based polyurethane acrylic pressure-sensitive adhesive comprises, by weight percentage, the following raw material components: 70%-80% acrylate prepolymer, 1%-4% isocyanate, 0.1%-0.3% catalyst, 0.5%-1% diamine, and 15%-25% pressure-sensitive adhesive solvent; wherein, the acrylate prepolymer comprises, by weight, the following raw material components: 2-6 parts hydroxyl-containing acrylic monomer, 55-75 parts bio-based acrylic monomer, 0.4-1 parts initiator, and 30-40 parts modified solvent.
[0029] It is understandable that hydroxyl-containing acrylic monomers, bio-based acrylic monomers, and initiators are used to prepare acrylate prepolymers. By controlling the ratio of isocyanate, diamine, and acrylate prepolymers, a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic as the soft segment and urethane and urea groups as the hard segments can be produced.
[0030] This involves constructing a microphase-separated structure within the bio-based polyurethane acrylic pressure-sensitive adhesive, with acrylate as the soft segments and urethane groups and urea bonds as the hard segments. This physical crosslinking method, replacing the traditional chemical crosslinking method using a curing agent, not only improves the material's cohesive energy and shear strength but also enhances the surface polarity of the adhesive film, thereby increasing the adhesive strength of the pressure-sensitive adhesive.
[0031] Through extensive experimental data, the inventors accidentally discovered that polyurethane possesses a unique microphase separation structure. The urethane groups form hydrogen bonds with each other, creating hard segments, while the polyol segments form soft segments. This structure gives polyurethane extremely high cohesive energy, leading to its widespread application across various industries. Therefore, by modifying bio-based acrylic acid with polyurethane, using physically cross-linked segments as hard segments and bio-based acrylic acid segments as soft segments to construct a structure where hard and soft segments are separated, high-performance bio-based acrylic pressure-sensitive adhesives can be prepared.
[0032] Specifically, the bio-based acrylic monomer is at least one of isoborneol acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate, tridecyl acrylate, isoborneol methacrylate, and lauryl methacrylate.
[0033] Specifically, the hydroxyl-containing acrylic monomer is hydroxyethyl acrylate.
[0034] Specifically, the initiator is at least one of azobisisobutyronitrile and dimethyl azobisisobutyrate.
[0035] Specifically, the diamine is at least one of hydrazine hydrate, ethylenediamine, hexamethylenediamine, and isophorone diamine.
[0036] Specifically, the isocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.
[0037] Specifically, the catalyst is at least one of bismuth neodecanoate and stannous octoate.
[0038] Specifically, both the modified solvent and the pressure-sensitive adhesive solvent are selected from at least one of ethyl acetate, acetone, and butanone.
[0039] Embodiments of the present invention provide a method for preparing a bio-based polyurethane acrylic pressure-sensitive adhesive, which can be used to prepare the above-mentioned bio-based polyurethane acrylic pressure-sensitive adhesive. The preparation method includes the following steps:
[0040] S1. Acrylate prepolymer is prepared.
[0041] Specifically, the steps for preparing acrylate prepolymers can be as follows:
[0042] Mix 2-6 parts of hydroxyl-containing acrylic monomer, 30-40 parts of bio-based acrylic monomer, 0.2-0.5 parts of initiator and 30-40 parts of modified solvent, and stir at 75-80℃ for 30-60 minutes.
[0043] Add 25-35 parts of bio-based acrylic acid and 0.2-0.5 parts of initiator dropwise to the above system, with a dropwise addition time of less than 1 hour. After the dropwise addition is complete, stir the entire mixed reaction system at a temperature of 75-85℃ for 1-2 hours.
[0044] S2. Mix the acrylate prepolymer with isocyanate to react and obtain an intermediate product.
[0045] Specifically, step S2 can be: mixing the acrylate prepolymer, isocyanate and catalyst at 60-70℃, and stirring the mixture at 80-85℃ for 2-3 hours.
[0046] S3. Mix the intermediate product with a diamine and react them. Add a solvent to obtain a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic acid as the soft segment and urethane and urea groups as the hard segments.
[0047] Specifically, step S3 can be: adding a diamine to the intermediate product and reacting for 30-60 minutes, then adding the pressure-sensitive adhesive solvent.
[0048] The preparation method of this invention can effectively construct a microphase-separated structure within the bio-based polyurethane acrylic pressure-sensitive adhesive, with acrylate as the soft segment and urethane groups and urea bonds as the hard segment. This physical crosslinking method, replacing the traditional method of using a curing agent to generate chemical crosslinking, not only improves the cohesive energy and shear strength of the material but also enhances the surface polarity of the adhesive film, thereby increasing the adhesive strength of the pressure-sensitive adhesive.
[0049] The present invention will be specifically described below through embodiments, which are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-described content, which still fall within the scope of protection of the present invention.
[0050] Example 1:
[0051] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 6 parts of hydroxyethyl acrylate, 30 parts of lauryl acrylate, 0.5 parts of azobisisobutyronitrile and 35 parts of modified solvent were placed in a reaction flask and stirred at 80℃ for 30 min. Then, 28 parts of lauryl acrylate and 0.5 parts of azobisisobutyronitrile were added dropwise over 1 h and stirred at 80℃ for 1 h.
[0052] Bio-based polyurethane acrylic pressure-sensitive adhesive: 80 parts of acrylate prepolymer, 2 parts of isophorone diisocyanate and 0.2 parts of bismuth neodecanoate were added at 65°C and stirred for 3 hours. 1 part of hydrazine hydrate was added and the reaction continued for 30 minutes. 16.8 parts of pressure-sensitive adhesive solvent were added to obtain a bio-based acrylic adhesive with acrylate as the soft segment, urethane groups and urea bonds as the hard segments, and an adhesive viscosity of 2176 cps.
[0053] Example 2:
[0054] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 2 parts hydroxyethyl acrylate, 40 parts tetrahydrofurfuryl acrylate, 0.2 parts dimethyl azobisisobutyrate and 40 parts modified solvent were placed in a reaction flask, and the mixture was stirred at 75℃ for 30 min. Then, 20 parts lauryl acrylate and 0.3 parts dimethyl azobisisobutyrate were added dropwise over 1 h, and the mixture was stirred at 80℃ for 1 h to obtain the prepolymer.
[0055] Bio-based polyurethane acrylic pressure-sensitive adhesive: 70 parts of acrylate prepolymer, 4 parts of hexamethylene diisocyanate and 0.3 parts of bismuth neodecanoate were added at 65°C and stirred at 80°C for 3 hours. 0.8 parts of ethylenediamine were added and the reaction continued for 30 minutes. 24.9 parts of pressure-sensitive adhesive solvent were added to obtain a bio-based acrylic adhesive with acrylate as the soft segment, urethane groups and urea bonds as the hard segments, and an adhesive viscosity of 2598 cps.
[0056] Example 3:
[0057] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 4 parts of hydroxyethyl acrylate, 36 parts of tridecanol acrylate, 0.4 parts of dimethyl azobisisobutyrate and 40 parts of modified solvent were placed in a reaction flask. The mixture was stirred at 75°C for 30 min. Then, 20 parts of isobornyl methacrylate and 0.3 parts of dimethyl azobisisobutyrate were added dropwise over 1 h. The mixture was stirred at 80°C for 1 h to obtain the prepolymer.
[0058] Bio-based polyurethane acrylic pressure-sensitive adhesive: 75 parts of acrylate prepolymer, 2 parts of hexamethylene diisocyanate and 0.1 parts of bismuth neodecanoate were added at 65°C and stirred at 80°C for 2 hours. 0.5 parts of hexamethylenediamine were added and the reaction continued for 30 minutes. 22.4 parts of pressure-sensitive adhesive solvent were added to obtain a bio-based acrylic adhesive with acrylate as the soft segment, urethane groups and urea bonds as the hard segments, and an adhesive viscosity of 3892 cps.
[0059] Example 4:
[0060] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 5 parts of hydroxyethyl acrylate, 35 parts of lauryl methacrylate, 0.3 parts of azobisisobutyronitrile and 37 parts of modified solvent were placed in a reaction flask and stirred at 75℃ for 45 min. Then, 27 parts of isobornyl methacrylate and 0.5 parts of azobisisobutyronitrile were added dropwise over 1 h, and stirred at 85℃ for 1 h.
[0061] Bio-based polyurethane acrylic pressure-sensitive adhesive: 76 parts of acrylate prepolymer, 2 parts of isophorone diisocyanate and 0.3 parts of bismuth neodecanoate were added at 65°C and stirred for 3 hours under controlled temperature of 85°C. 1 part of hydrazine hydrate was added and the reaction continued for 30 minutes. 20.7 parts of pressure-sensitive adhesive solvent were added to obtain a bio-based acrylic adhesive with acrylate as the soft segment, urethane groups and urea bonds as the hard segments, and an adhesive viscosity of 2382 cps.
[0062] Example 5:
[0063] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 5 parts of hydroxyethyl acrylate, 35 parts of lauryl methacrylate, 0.3 parts of azobisisobutyronitrile and 37 parts of modified solvent were placed in a reaction flask and stirred at 75℃ for 45 min. Then, 27 parts of isobornyl methacrylate and 0.5 parts of azobisisobutyronitrile were added dropwise over 1 h, and stirred at 85℃ for 1 h.
[0064] Bio-based polyurethane acrylic pressure-sensitive adhesive: 73 parts of acrylate prepolymer, 1 part of isophorone diisocyanate and 0.3 parts of bismuth neodecanoate were added at 65°C and stirred for 3 hours under controlled temperature of 85°C. 0.7 parts of hydrazine hydrate were added and the reaction was continued for 30 minutes. 25 parts of pressure-sensitive adhesive solvent were added to obtain a bio-based acrylic adhesive with acrylate as the soft segment, urethane groups and urea bonds as the hard segments, and an adhesive viscosity of 2480 cps.
[0065] Comparative Example 1:
[0066] Preparation of acrylate prepolymer: Under nitrogen atmosphere, 6 parts of hydroxyethyl acrylate, 30 parts of lauryl acrylate, 0.5 parts of azobisisobutyronitrile and 35 parts of modified solvent were placed in a reaction flask and stirred at 80℃ for 30 min. Then, 28 parts of lauryl acrylate and 0.5 parts of azobisisobutyronitrile were added dropwise over 1 h, and the mixture was stirred at 80℃ for 1 h. After cooling, the acrylate prepolymer was obtained.
[0067] Bio-based polyurethane acrylic pressure-sensitive adhesive: When using it, mix 80 parts of acrylate prepolymer and 2 parts of isophorone diisocyanate evenly and apply it evenly to the substrate. After drying and curing, the bio-based polyurethane acrylic pressure-sensitive adhesive is obtained.
[0068] Comparative Example 2:
[0069] In a nitrogen atmosphere, 2 parts of hydroxyethyl acrylate, 40 parts of tetrahydrofurfuryl acrylate, 0.2 parts of dimethyl azobisisobutyrate, and 40 parts of modified solvent were placed in a reaction flask. The mixture was stirred at 75°C for 30 min. Then, 20 parts of lauryl acrylate and 0.3 parts of dimethyl azobisisobutyrate were added dropwise over 1 h, and the mixture was stirred at 80°C for 1 h to obtain the final product.
[0070] Bio-based polyurethane acrylic pressure-sensitive adhesive: When using it, mix 70 parts of acrylate prepolymer and 4 parts of hexamethylene diisocyanate evenly and apply it evenly to the substrate. After drying and curing, the bio-based polyurethane acrylic pressure-sensitive adhesive is obtained.
[0071] Comparative Example 3:
[0072] In a nitrogen atmosphere, 4 parts of hydroxyethyl acrylate, 36 parts of tridecyl acrylate, 0.4 parts of dimethyl azobisisobutyrate, and 40 parts of modified solvent were placed in a reaction flask. The mixture was stirred at 75°C for 30 min. Then, 20 parts of isobornyl methacrylate and 0.3 parts of dimethyl azobisisobutyrate were added dropwise over 1 h, and the mixture was stirred at 80°C for 1 h to obtain the final product.
[0073] Bio-based polyurethane acrylic pressure-sensitive adhesive: When using it, mix 75 parts of acrylate prepolymer and 2 parts of hexamethylene diisocyanate evenly and apply it evenly to the substrate. After drying and curing, the bio-based polyurethane acrylic pressure-sensitive adhesive is obtained.
[0074] Comparative Example 4:
[0075] In a nitrogen atmosphere, 5 parts of hydroxyethyl acrylate, 35 parts of lauryl methacrylate, 0.3 parts of azobisisobutyronitrile and 37 parts of modified solvent were placed in a reaction flask. The mixture was stirred at 75°C for 45 min. Then, 27 parts of isobornyl methacrylate and 0.5 parts of azobisisobutyronitrile were added dropwise over 1 h, and the mixture was stirred at 85°C for 1 h.
[0076] Bio-based polyurethane acrylic pressure-sensitive adhesive: When using it, mix 76 parts of acrylate prepolymer and 2 parts of isophorone diisocyanate evenly and apply it evenly to the substrate. After drying and curing, the bio-based polyurethane acrylic pressure-sensitive adhesive is obtained.
[0077] The following performance tests were performed on the pressure-sensitive adhesives in Examples 1-5 and Comparative Examples 1-4:
[0078] (1) 180° peel strength test of steel plate: Reference standard: GB / T 2792-2014
[0079] All samples must be placed in an environment of 23℃±2℃ and 50%±5% RH for 24 hours before testing. Take a strip of pressure-sensitive adhesive tape with a width of 25±0.5mm and a length of 300±20mm, remove the backing material, and place the adhesive side down on a clean steel plate with light finger pressure. Then, use a 2kg manual or automatic roller to roll back and forth 3 times at a speed of approximately 5mm / s to ensure close contact between the adhesive side and the test plate surface, without any air bubbles. After the sample is prepared, place it in a steel plate frame and let it stand. Set a timer for 20 minutes, and then perform the peel force test at a test speed of 300mm / min.
[0080] (2) Dynamic shear force performance test:
[0081] Reference standard: GB / T 33332-2016
[0082] All samples must be placed in an environment of 23℃±2℃ and 50%±5% RH for 24 hours before testing. Cut the samples into 12.5mm*12.5mm standard test specimens, and prepare at least 3 standard test specimens for each test item. First, remove the backing material from one side of the strip to be tested, with the adhesive side down, and use a small adhesive roller to attach the strip to one end of a clean SUS test plate (leaving a gap of approximately 30mm at the top). Then remove the backing material from the other end, and attach one end of another SUS test plate to the test strip (again, leaving a certain gap at the top). After attachment, use a manual roller to roll back and forth once at a speed of approximately 5mm / s to ensure that the adhesive side is in close contact with the surface of the test plate, without any air bubbles. After the sample is prepared, place it in the stop rack and let it stand. Set the timer for 20 minutes, and then perform the peel force test. Place the settled tape sample onto the fixture, ensuring that the upper and lower fixtures lock the blank part of the SUS plate. When clamping the sample, ensure that the shear angle is 180°. Click the "Start Test" button on the tensile testing machine according to the test requirements. The test is complete when either of the two SUS plates separates from the sample colloid. Record 3 valid test values for each test material, in MPa.
[0083] (3) Viscosity test (only Examples 1-5 were tested):
[0084] Reference Standard: 2794-2013
[0085] Referring to the Brookfield DV-1 model, select an appropriate rotor and speed to ensure the reading is between 20% and 90% of the maximum range. If the sample exceeds the range and the machine alarms, a new rotor needs to be selected, generally one size larger. Fill the beaker or sample container with the sample to be measured, ensuring no air bubbles are introduced. If necessary, eliminate air bubbles using vacuum or other suitable methods. Screw the selected rotor onto the connecting screw, immerse the rotor in the sample, and rotate the lifting knob to slowly lower the instrument, gradually immersing the rotor into the liquid being tested until the rotor's liquid level mark is level with the liquid surface. After setting the rotor speed, begin the viscosity test. Record the data; once the data in the upper left corner of the display stabilizes, this is the sample viscosity value.
[0086] The test data are shown in the table below:
[0087]
[0088] The bio-based polyurethane acrylic pressure-sensitive adhesive of the present invention has the following beneficial effects:
[0089] 1. Currently, bio-based acrylates exhibit good wettability, but their cohesive energy is too low. While adding crosslinking agents or using hard bio-based acrylic monomers can increase the cohesive energy, it can lead to a decrease in wettability and adhesive strength of the substrate. The bio-based polyurethane acrylic pressure-sensitive adhesive prepared using this technology can simultaneously meet the above-mentioned performance requirements, comprehensively enhancing the application value of bio-based acrylic pressure-sensitive adhesives.
[0090] 2. Compared with other polyurethane modification methods, this method does not require the prior synthesis of isocyanate prepolymers, has a shorter synthesis step, is simple to operate, and is easy to achieve large-scale production.
[0091] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.
Claims
1. A bio-based polyurethane acrylic pressure-sensitive adhesive, characterized in that, The raw material components, by mass percentage, include: 70%-80% acrylate prepolymer, 1%-4% isocyanate, 0.1%-0.3% catalyst, 0.5%-1% diamine, and 15%-25% pressure-sensitive adhesive solvent. The bio-based polyurethane acrylic pressure-sensitive adhesive is a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic acid as the soft segment and urethane and urea groups as the hard segments. The diamine is at least one of hydrazine hydrate, ethylenediamine, hexamethylenediamine, and isophorone diamine. The acrylate prepolymer comprises, by mass parts, the following raw material components: 2-6 parts of hydroxyl-containing acrylic monomer, 55-75 parts of bio-based acrylic monomer, 0.4-1 parts of initiator, and 30-40 parts of modified solvent. The preparation method of the bio-based polyurethane acrylic pressure-sensitive adhesive includes the following steps: Acrylate prepolymer was prepared; The acrylate prepolymer is mixed with isocyanate and reacted to obtain an intermediate product; The intermediate product was mixed with a diamine and reacted. A pressure-sensitive adhesive solvent was added to obtain a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic acid as the soft segment and urethane and urea groups as the hard segments.
2. The bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 1, characterized in that, The bio-based acrylic monomer is at least one selected from isoborneol acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate, and tridecanol acrylate; and / or, The hydroxyl-containing acrylic monomer is hydroxyethyl acrylate.
3. The bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 1, characterized in that, The initiator is at least one of azobisisobutyronitrile and dimethyl azobisisobutyrate.
4. The bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 1, characterized in that, The isocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.
5. The bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 1, characterized in that, The catalyst is at least one of bismuth neodecanoate and stannous octoate.
6. A method for preparing a bio-based polyurethane acrylic pressure-sensitive adhesive as described in any one of claims 1-5, characterized in that, Includes the following steps: Acrylate prepolymer was prepared; The acrylate prepolymer is mixed with isocyanate and reacted to obtain an intermediate product; The intermediate product was mixed with a diamine and reacted. A pressure-sensitive adhesive solvent was added to obtain a bio-based polyurethane acrylic pressure-sensitive adhesive with bio-based acrylic acid as the soft segment and urethane and urea groups as the hard segments.
7. The preparation method of the bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 6, characterized in that, The step of preparing the acrylate prepolymer includes: Mix 2-6 parts of hydroxyl-containing acrylic monomer, 30-40 parts of bio-based acrylic monomer, 0.2-0.5 parts of initiator and 30-40 parts of modified solvent, and stir at 75-80℃ for 30-60 minutes. Add 25-35 parts of bio-based acrylic acid and 0.2-0.5 parts of initiator dropwise to the above system, with a dropwise addition time of less than 1 hour. After the dropwise addition is complete, stir the entire mixed reaction system at a temperature of 75-85℃ for 1-2 hours.
8. The method for preparing the bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 6, characterized in that, The specific steps of mixing and reacting the acrylate prepolymer with the isocyanate include: The acrylate prepolymer, isocyanate and catalyst are mixed at 60-70℃ and stirred at 80-85℃ for 2-3 hours.
9. The preparation method of the bio-based polyurethane acrylic pressure-sensitive adhesive as described in claim 6, characterized in that, The step of mixing and reacting the intermediate product with the diamine and adding the pressure-sensitive adhesive solvent includes: Add a diamine to the intermediate product and react for 30-60 minutes, then add the pressure-sensitive adhesive solvent.