Bio-based ultraviolet curing adhesive as well as preparation and use methods thereof
The UV-curable adhesive, prepared by optimizing bio-based raw materials, solves the problem of performance degradation of bio-based adhesives after contact with human secretions, achieving high strength and resistance to chemical corrosion, and is suitable for wearable electronic devices.
Patent Information
- Application Number
- CN202511237779.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2025-10-31
AI Technical Summary
Existing bio-based UV-curable adhesives tend to swell or lose strength after contact with human secretions, making it difficult to meet the requirements for high-performance bonding and resistance to chemical corrosion.
Bio-based polyurethane prepolymers were prepared by reacting bio-based diols with isocyanates, and bio-based UV-curable adhesives were prepared by optimizing the reaction with bio-based end-capping agents and diluents, thereby introducing lactic acid groups to improve chemical resistance.
The prepared bio-based UV-curable adhesive has excellent mechanical properties, adhesive properties and resistance to oleic acid corrosion, making it suitable for wearable electronic devices and providing a high-performance green adhesive solution.
Smart Images
Figure CN120865831A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of adhesive technology, and relates to ultraviolet light curable adhesives, specifically to a bio-based ultraviolet light curable adhesive and its preparation and application methods. Background Technology
[0002] With the rapid development of wearable devices, electronic products, and medical devices, the demand for high-performance adhesives is increasing. UV-curable adhesives are widely used in electronic product positioning and bonding, medical devices, and aerospace due to their convenience and efficiency. However, traditional UV-curable adhesives mostly use petroleum-based raw materials, relying on non-renewable resources and posing environmental pollution problems. Furthermore, wearable devices frequently come into contact with human secretions during use, such as sweat and sebum containing highly corrosive oleic acid. While sweat, mainly composed of inorganic small molecules, has an unstable bond with adhesive molecules and a relatively small impact on the adhesive, traditional adhesives are more susceptible to corrosion from oleic acid in sebum, leading to decreased bonding and mechanical properties, affecting device reliability and lifespan. Therefore, improving resistance to oleic acid and other chemicals is an important research direction in the field of wearable device adhesives.
[0003] In recent years, bio-based materials have attracted much attention due to their renewability and environmental friendliness, becoming a rapidly growing emerging industry. Using bio-based raw materials to replace petroleum-based raw materials in the preparation of UV-curable adhesives can significantly reduce carbon footprint, meeting the requirements of green development. However, existing bio-based adhesives still have shortcomings in mechanical properties, adhesive properties, and chemical resistance, especially after contact with human secretions, where they are prone to swelling or strength reduction, making it difficult to meet practical application needs. Therefore, developing a high-bio-based UV-curable adhesive with excellent mechanical properties, adhesive properties, and chemical resistance is of great significance for promoting the development of green adhesives. Summary of the Invention
[0004] This invention addresses the problems of existing UV-curable adhesives, such as reliance on petroleum-based raw materials, poor chemical resistance, and significant decrease in tensile and adhesive strength after corrosion. It provides a bio-based UV-curable adhesive and its preparation and application methods.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] A method for preparing a bio-based ultraviolet-curable adhesive, the method comprising the following steps:
[0007] Step 1: Weigh 40-70 parts of bio-based diol according to the weight ratio, dehydrate it under vacuum at 90-120 ℃ for 2-3 hours, cool it down to 30-60 ℃, add 20-40 parts of isocyanate, and react at 60-90 ℃ for 2-4 hours to obtain bio-based polyurethane prepolymer.
[0008] Step 2: Cool the bio-based polyurethane prepolymer obtained in Step 1 to 30~60 ℃, add 20~40 parts of bio-based end-capping agent and 0.01~0.05 parts of polymerization inhibitor, and react at 60~90 ℃ for 3~5 h to obtain bio-based polyurethane acrylate oligomer.
[0009] Step 3: Mix the bio-based polyurethane acrylate oligomer obtained in Step 2 with 20-50 parts of bio-based diluent and 1-5 parts of photoinitiator to obtain a bio-based UV-curable adhesive.
[0010] Further, in step one, the bio-based diol is one or more of bio-based polytrimethylene ether glycol, bio-based polylactic acid glycol, and bio-based castor oil glycol, with a molecular weight of 500-2500 and a functionality of 2.
[0011] Further, in step one, the isocyanate is one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and dicyclohexylmethane diisocyanate (HMDI), with a functionality of 2.
[0012] Furthermore, in step two, the bio-based capping agent is a bio-based dilactic acid-derived hydroxyl acrylate.
[0013] Furthermore, the bio-based dilactic acid-derived hydroxy acrylate is one or more combinations of PLA AA100, PLA AA120, and PLA AM100. Its structural formula is as follows:
[0014] Furthermore, in step two, the polymerization inhibitor is one or more combinations of phenothiazine, p-hydroxyanisole, hydroquinone, and 2-tert-butylhydroquinone.
[0015] Further, in step three, the bio-based diluent is one or a combination of bio-based isobornyl methacrylate (IBOMA), bio-based tetrahydrofurfuryl methacrylate (THFA), bio-based isobornyl acrylate (IBOA), bio-based isodecyl methacrylate (IDMA), PLA AA100, PLA AA120, and PLA AM100.
[0016] Further, in step three, the photoinitiator is one or more combinations of methyl benzoylformate, hydroxycyclohexanephenyl ketone, and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.
[0017] A bio-based ultraviolet-curable adhesive prepared by the above preparation method.
[0018] A method for using the bio-based ultraviolet-curable adhesive prepared by the above preparation method, wherein the method comprises: irradiating with an ultraviolet light source of 200~500 nm for 5~60 s to initiate curing.
[0019] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention optimizes the formulation of bio-based raw materials, replacing petroleum-based diols with bio-based diols in the reaction with isocyanates to obtain bio-based polyurethane prepolymers, and further replacing petroleum-based end-capping agents with bio-based end-capping agents to obtain bio-based polyurethane acrylate oligomers. Based on this, a bio-based UV-curable adhesive is prepared by compounding with bio-based diluents and photoinitiators. This invention uses multi-dimensional bio-based raw materials such as bio-based diols, bio-based end-capping agents, and bio-based diluents, and obtains a bio-based UV-curable adhesive with excellent mechanical properties, adhesive properties, and oleic acid corrosion resistance through the optimization and combination of various bio-based components. Specifically, the bio-based end-capping agent introduces lactic acid groups with excellent chemical resistance into the adhesive structure, effectively improving the oleic acid resistance of the UV-curable adhesive. The UV-curable adhesive of this invention is a green and environmentally friendly adhesive with advantages such as high strength and good chemical resistance, providing a high-performance green bonding solution for wearable electronic devices. Attached Figure Description
[0020] Figure 1 The images show the infrared spectra of the bio-based polyurethane prepolymer and the bio-based polyurethane acrylate oligomer in Example 1. Detailed Implementation
[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0022] Example 1:
[0023] Preparation of bio-based polyurethane prepolymer: 50.4 g of SK Bio-based polytrimethylene ether glycol (POG3-1000, Mw=1000) was weighed and added to a reaction flask. The mixture was dehydrated under vacuum at 120 °C for 2.0 h, then cooled to 45 °C. 22.5 g of isophorone diisocyanate was added, and the reaction was carried out at 70 °C for 2.0 h to obtain the bio-based polyurethane prepolymer. The infrared spectrum of the obtained bio-based polyurethane prepolymer is shown below. Figure 1 As shown, at 3340 cm -1 The absorption peak at 1724 cm⁻¹ is the NH stretching vibration peak of the amino group. -1The absorption peak at this point is a characteristic peak of C=O stretching vibration, proving the successful synthesis of the polyurethane structure;
[0024] Preparation of bio-based polyurethane acrylate oligomers: The obtained bio-based polyurethane prepolymer was cooled to 45 °C, and 29.3 g of a bio-based end-capping agent (PLA AM100) and 30.7 mg of a polymerization inhibitor phenothiazine were added. The mixture was then reacted at 70 °C for 4.0 h to obtain the bio-based polyurethane acrylate oligomers. The infrared spectrum of the obtained bio-based polyurethane acrylate oligomers is shown below. Figure 1 As shown, 1643 cm -1 With 818 cm -1 The absorption peak at 2264 cm⁻¹ is attributed to the C=C stretching vibration, indicating the successful introduction of the C=C structure of the acrylate, and... -1 The absence of a -NCO stretching vibration absorption peak indicates that the isocyanate groups in the bio-based polyurethane prepolymer have reacted completely.
[0025] Preparation of bio-based UV-curable adhesive: The prepared bio-based polyurethane acrylate oligomer was mixed evenly with 46.0 g of bio-based isoborneol methacrylate (diluent) and 4.09 g of methyl benzoylformate (photoinitiator). The curing conditions were irradiation with a 325 nm UV light source for 20 s.
[0026] Example 2:
[0027] Preparation of bio-based polyurethane prepolymer: 60.5 g of SK's bio-based polylactic acid glycol (Mw=1000) was weighed and added to a reaction flask, and dehydrated under vacuum at 110 °C for 3.0 h. The temperature was then lowered to 40 °C, 27.0 g of isophorone diisocyanate was added, and the reaction was carried out at 70 °C for 2.0 h to obtain the bio-based polyurethane prepolymer.
[0028] Preparation of bio-based polyurethane acrylate oligomers: The obtained bio-based polyurethane prepolymer was cooled to 40 °C, and 34.2 g of bio-based end-capping agent (PLA AA120) and 41.4 mg of polymerization inhibitor p-hydroxyanisole were added. The mixture was then reacted at 80 °C for 3.0 h to obtain bio-based polyurethane acrylate oligomers.
[0029] Preparation of bio-based UV-curable adhesive: The prepared bio-based polyurethane acrylate oligomer was mixed with 31.6 g of bio-based isobornyl methacrylate (diluent) and 4.75 g of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator) and cured under the following conditions: irradiation with a 365 nm UV light source for 15 s.
[0030] Example 3:
[0031] Preparation of bio-based polyurethane prepolymer: 50.4 g of SK's bio-based polytrimethylene ether glycol (POG3-1000, Mw=1000) was weighed and added to a reaction flask. The mixture was dehydrated under vacuum at 115 °C for 2.5 h, cooled to 45 °C, and 19.1 g of isophorone diisocyanate and 2.6 g of toluene diisocyanate were added. The mixture was then reacted at 75 °C for 2.0 h to obtain the bio-based polyurethane prepolymer.
[0032] Preparation of bio-based polyurethane acrylate oligomers: The obtained bio-based polyurethane prepolymer was cooled to 45 °C, and 29.3 g of bio-based end-capping agent (PLA AM100) and 30.4 mg of polymerization inhibitor hydroquinone were added. The mixture was then reacted at 75 °C for 3.5 h to obtain bio-based polyurethane acrylate oligomers.
[0033] Preparation of bio-based UV-curable adhesive: The prepared bio-based polyurethane acrylate oligomer was mixed with 22.8 g of bio-based isoborneol methacrylate (diluent) and 22.8 g of bio-based isoborneol acrylate (diluent) and 4.56 g of hydroxycyclohexane phenyl ketone (photoinitiator) and cured under the following conditions: irradiation with a 365 nm UV light source for 20 s.
[0034] Example 4:
[0035] Preparation of bio-based polyurethane prepolymer: 60.5 g of SK's bio-based polytrimethylene ether glycol (POG3-1000, Mw=1000) was weighed and added to a reaction flask. The mixture was dehydrated under vacuum at 120 °C for 2.0 h, cooled to 40 °C, and 22.9 g of isophorone diisocyanate and 3.1 g of toluene diisocyanate were added. The mixture was then reacted at 75 °C for 2.0 h to obtain the bio-based polyurethane prepolymer.
[0036] Preparation of bio-based polyurethane acrylate oligomers: The obtained bio-based polyurethane prepolymer was cooled to 40 °C, and 35.2 g of bio-based end-capping agent (PLA AM100) and 43.8 mg of polymerization inhibitor p-hydroxyanisole were added. The mixture was then reacted at 70 °C for 4.0 h to obtain bio-based polyurethane acrylate oligomers.
[0037] Preparation of bio-based UV-curable adhesive: The prepared bio-based polyurethane acrylate oligomer was mixed evenly with 13.4 g of bio-based isoborneol methacrylate (diluent), 13.4 g of bio-based isoborneol acrylate (diluent), 27.4 g of PLA AA120 (diluent), and 3.65 g of methyl benzoate (photoinitiator). The curing conditions were irradiation with a 325 nm UV light source for 25 s.
[0038] Comparative example:
[0039] Preparation of petroleum-based polyurethane prepolymer: 50.4 g of SK's petroleum-based diol polytetramethylene ether glycol (PTMG-1000, Mw=1000) was weighed and added to a reaction flask. The mixture was dehydrated under vacuum at 120 °C for 2.0 h, cooled to 45 °C, and 22.5 g of isophorone diisocyanate was added. The mixture was reacted at 70 °C for 2.0 h to obtain the petroleum-based polyurethane prepolymer.
[0040] Preparation of petroleum-based polyurethane acrylate oligomers: The obtained petroleum-based polyurethane prepolymer was cooled to 45 °C, and 11.8 g of petroleum-based end-capping agent hydroxyethyl acrylate and 24.5 mg of polymerization inhibitor phenothiazine were added. The mixture was then reacted at 75 °C for 3.0 h.
[0041] Preparation of petroleum-based UV-curable adhesive: The obtained petroleum-based polyurethane acrylate oligomer was mixed with 22.0 g of isobornyl methacrylate (diluent) and 3.30 g of hydroxycyclohexane phenyl ketone (photoinitiator) and cured under the following conditions: irradiation with a 365 nm UV light source for 15 s.
[0042] Tensile strength was determined according to GB / T 1040-2008 "Determination of Tensile Properties of Plastics". After etching the sample in oleic acid for 24 hours, the sample was removed, residual chemicals were wiped off, and the sample was left in air for 3 hours before testing its tensile strength after oleic acid etching. Tensile shear strength was determined according to GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives". The sample was immersed in oleic acid and placed in a humidity and temperature chamber at 85°C for 24 hours. After removing the sample and wiping off residual chemicals, its tensile shear strength after oleic acid etching was tested. The oleic acid absorption rate was determined by immersing a 2 mm × 2 mm square adhesive film in oleic acid for 24 hours, removing it, wiping off residual oleic acid, and leaving it in air for 3 hours before testing.
[0043] Table 1. Performance comparison of UV-curable adhesives in the examples and comparative examples
[0044]
[0045] As shown in Table 1, the tensile strength and tensile shear strength of the bio-based UV-curable adhesives in Examples 1-4 of this invention are higher than those of the petroleum-based adhesives, while their oleic acid absorption rates are significantly lower. Furthermore, the tensile strength and retention rate after oleic acid corrosion, as well as the tensile shear strength after oleic acid corrosion, are all higher than those of the petroleum-based adhesives, indicating that they possess excellent mechanical properties, adhesive properties, and resistance to oleic acid corrosion. The superior performance of the bio-based UV-curable adhesives of this invention stems from the optimized and combined use of various bio-based components. The use of bio-based dimer lactic acid-derived hydroxyl acrylate end-capping agents introduces lactic acid groups with excellent chemical resistance into the adhesive structure, effectively improving its resistance to oleic acid corrosion. Moreover, this invention utilizes multi-dimensional bio-based raw materials such as bio-based diols, bio-based end-capping agents, and bio-based diluents, resulting in an adhesive with a high bio-based content. Therefore, the bio-based UV-curable adhesives of this invention have advantages such as being environmentally friendly, having high strength, and good chemical resistance, providing a high-performance green bonding solution for wearable electronic devices.
[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing a bio-based ultraviolet-curable adhesive, characterized in that: The method includes the following steps: Step 1: Weigh 40-70 parts of bio-based diol according to the weight ratio, dehydrate it under vacuum at 90-120 ℃ for 2-3 h, cool it down to 30-60 ℃, add 20-40 parts of isocyanate, and react at 60-90 ℃ for 2-4 h to obtain bio-based polyurethane prepolymer. Step 2: Cool the bio-based polyurethane prepolymer obtained in Step 1 to 30~60 ℃, add 20~40 parts of bio-based end-capping agent and 0.01~0.05 parts of polymerization inhibitor, and react at 60~90 ℃ for 3~5 h to obtain bio-based polyurethane acrylate oligomer. Step 3: Mix the bio-based polyurethane acrylate oligomer obtained in Step 2 with 20-50 parts of bio-based diluent and 1-5 parts of photoinitiator to obtain a bio-based UV-curable adhesive.
2. The preparation method according to claim 1, characterized in that: In step one, the bio-based diol is one or more of bio-based polytrimethylene ether glycol, bio-based polylactic acid glycol, and bio-based castor oil glycol, with a molecular weight of 500-2500 and a functionality of 2.
3. The preparation method according to claim 1, characterized in that: In step one, the isocyanate is one or more of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and dicyclohexylmethane diisocyanate, with a functionality of 2.
4. The preparation method according to claim 1, characterized in that: In step two, the bio-based capping agent is a bio-based dimer lactic acid-derived hydroxy acrylate.
5. The preparation method according to claim 4, characterized in that: The bio-based dilactic acid-derived hydroxy acrylate is one or more of PLA AA100, PLA AA120, and PLA AM100.
6. The preparation method according to claim 1, characterized in that: In step two, the polymerization inhibitor is one or a combination of phenothiazine, p-hydroxyanisole, hydroquinone, and 2-tert-butylhydroquinone.
7. The preparation method according to claim 1, characterized in that: In step three, the bio-based diluent is one or a combination of bio-based isobornyl methacrylate, bio-based tetrahydrofurfuryl methacrylate, bio-based isobornyl acrylate, bio-based isodecyl methacrylate, PLA AA100, PLA AA120, and PLA AM100.
8. The preparation method according to claim 1, characterized in that: In step three, the photoinitiator is one or more combinations of methyl benzoylformate, hydroxycyclohexanephenyl ketone, and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide.
9. A bio-based ultraviolet-curable adhesive prepared by the preparation method according to any one of claims 1 to 8.
10. A method of using a bio-based UV-curable adhesive prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The method is as follows: irradiation is performed using a 200~500 nm ultraviolet light source for 5~60 s to initiate curing.