UV moisture dual-curing adhesive and preparation process thereof

Abstract

The application discloses a UV moisture dual-curing adhesive and a preparation process thereof, and relates to the technical field of adhesives.The raw materials of the UV moisture dual-curing adhesive comprise the following components in terms of weight fractions: 60-70 parts of polyurethane acrylate, 3-5 parts of tetrahydrofuran acrylate, 5-7 parts of 1,6-glycol diacrylate, 15-20 parts of N,N-dimethyl acrylamide, 4-7 parts of isocyanatoethyl methacrylate, 6-8 parts of hexamethylene diisocyanate trimer, 4-6 parts of modified silicon dioxide, 1-2 parts of a photoinitiator, 0.1-0.5 parts of a defoaming agent, and 0.1-0.2 parts of a leveling agent.The UV moisture dual-curing adhesive prepared by the application has excellent bonding strength, improved water vapor barrier property, and can meet the application in a high-temperature and high-humidity environment.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to a UV moisture dual-curing adhesive and its preparation process. Background Technology

[0002] Adhesives are an important class of polymer materials, widely used in electronic packaging, automotive manufacturing, medical devices, and many other fields. Common curing methods for adhesives include thermosetting, UV curing, and moisture curing. Among these, thermosetting produces adhesive layers with good high-temperature resistance and high strength, but requires heating equipment, has a long curing time, and is cumbersome to operate. UV curing can achieve rapid curing, but due to the excessively fast curing, the curing stress is poor, the adhesive layer has poor flexibility, and is prone to cracking, affecting adhesion. Moisture curing, while simple to operate and low in cost, has a very long curing time.

[0003] Currently, novel dual-curing modes, compared to traditional single-curing adhesives, can meet more complex application needs and have become a research hotspot in recent years. Among them, UV-moisture dual-curing adhesives possess a unique synergistic curing mechanism; they simultaneously introduce double bonds for UV curing and molecules for moisture curing, first treating with UV light and then curing with moisture in air, balancing curing speed and adhesive performance, thus overcoming the problems of incomplete curing in the shaded area and oxygen inhibition in traditional UV curing processes. However, existing UV-moisture dual-curing adhesives have some drawbacks, such as poor moisture or high-temperature resistance; the adhesive is prone to debonding when exposed to moisture or high temperatures, leading to a decrease in adhesion strength. Some studies introduce hydrophobic materials to improve water resistance, but this presents dispersibility problems, resulting in a decrease in the adhesive's own adhesive properties; therefore, a balance needs to be struck between these properties.

[0004] In summary, solving the above problems and preparing a UV-curing adhesive that simultaneously satisfies the requirements of good adhesion and low water vapor permeability is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide a UV moisture dual-curing adhesive and its preparation process to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A UV moisture-curing dual-curing adhesive, wherein the raw materials of the UV moisture-curing dual-curing adhesive include the following components by weight: 60-70 parts polyurethane acrylate, 3-5 parts tetrahydrofuran acrylate, 5-7 parts 1,6-ethylene glycol diacrylate, 15-20 parts N,N-dimethylacrylamide, 4-7 parts isocyanate methacrylate, 6-8 parts hexamethylene diisocyanate trimer, 4-6 parts modified silica, 1-2 parts photoinitiator, 0.1-0.5 parts defoamer, and 0.1-0.2 parts leveling agent.

[0008] More preferably, the polyurethane acrylate includes fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 3.5~4:1~1.5.

[0009] A more optimized method for preparing the fluorinated polyurethane acrylate is as follows: Under a nitrogen atmosphere, a dehydrated polyester diol and pentaerythritol dimethacrylate are mixed evenly, and isophorone diisocyanate is added at 50-55°C; the mixture is stirred at 75-90°C for 1-2 hours; 1,4-butanediol and hexafluoropentanediol are added at 40-50°C, and the mixture is stirred for 0.5-1 hour; hydroxyethyl acrylate, 3-tetrahydrofuran methanol, and hydroquinone are added; the mixture is stirred and reacted at 75-90°C for 3-4 hours to obtain the fluorinated polyurethane acrylate.

[0010] More preferably, the raw materials for the fluorinated polyurethane acrylate include the following components by weight: 150-200 parts polyester diol, 15-20 parts pentaerythritol dimethacrylate, 3-5 parts 1,4-butanediol, 5-7 parts hexafluoropentanediol, 65-75 parts isophorone diisocyanate, 7-11 parts hydroxyethyl acrylate, 3-4 parts 3-tetrahydrofuran methanol, and 0.2-0.3 parts hydroquinone;

[0011] The average molecular weight of the polyester diol is 2000-3000; it includes one or two of polybutylene adipate diol and polyhexyl adipate diol.

[0012] A more optimized method for preparing the silicone-containing polyurethane acrylate is as follows: Under a nitrogen atmosphere, dihydroxyl-terminated polydimethylsiloxane, polyester diol, and pentaerythritol dimethacrylate are mixed evenly; isophorone diisocyanate is added at 50-55°C, and the mixture is stirred at 75-90°C for 30-40 minutes; 3-(trimethylsilyl)-1,2-propanediol is added at 40-50°C, and the mixture is stirred for 0.5-1 hour; 2-[1-(hydroxymethyl)ethyl]zoline and hydroxyethyl acrylate are added, and the mixture is stirred for another 3-4 hours to obtain the silicone-containing polyurethane acrylate.

[0013] More preferably, the raw materials of the silicone-containing polyurethane acrylate include the following components: by weight, 70-85 parts of dihydroxy-terminated polydimethylsiloxane, 10-15 parts of polyester diol, 10-15 parts of pentaerythritol dimethacrylate, 3-5 parts of 3-(trimethylsilyl)-1,2-propanediol, 3-5 parts of 2-[1-(hydroxymethyl)ethyl]zoline, 3-5 parts of hydroxyethyl acrylate, and 30-40 parts of isophorone diisocyanate.

[0014] Ideally, the average molecular weight of the dihydroxy-terminated polydimethylsiloxane is 1000.

[0015] A more optimized method for preparing the modified silica is as follows: S1.1: Disperse nano-silica in an 80-85 wt% aqueous ethanol solution, add an aminosilane coupling agent, stir at 60-70°C for 4-8 hours, filter and dry to obtain aminated silica; S1.2: Add the aminated silica to N-methylpyrrolidone, add an organotin catalyst; under a nitrogen atmosphere, add pentaerythritol dimethacrylate, 1,4-butanediol, isophorone diisocyanate and hexafluoropentanediol, stir and react at 75-90°C for 10-12 hours, wash and dry to obtain modified silica.

[0016] More optimally, the mass ratio of the nano-silica to the aminosilane coupling agent is 1:0.2~0.4; the raw material of the modified silica includes the following components by weight: 10 parts of aminated silica, 2~3 parts of pentaerythritol dimethacrylate, 10~12 parts of isophorone diisocyanate, 3~5 parts of 1,4-butanediol, 2~3 parts of hexafluoropentanediol, 0.1~0.5 parts of organotin catalyst, and 100 parts of N-methylpyrrolidone.

[0017] In a more optimized manner, under a nitrogen atmosphere, polyurethane acrylate, tetrahydrofuran acrylate, 1,6-ethylene glycol diacrylate, N,N-dimethylacrylamide, isocyanate methacrylate, and hexamethylene diisocyanate are stirred at 40-50°C at 400-800 rpm for 20-30 min; then modified silica, photoinitiator, defoamer, and leveling agent are added sequentially, and the mixture is stirred at 800-1000 rpm for 30-40 min. The nitrogen atmosphere is then depressurized to obtain a UV-moisture dual-curing adhesive.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: a polyurethane acrylate body is formed by using a specific ratio of fluorinated polyurethane acrylate and silicone polyurethane acrylate, forming a double cross-linked UV moisture double curing; and modified silica is introduced to effectively improve cohesion and enhance adhesion; thus, the UV moisture double curing adhesive has excellent bonding strength and improved water vapor barrier properties, enabling it to meet its application in high temperature and high humidity environments.

[0019] The fluorinated polyurethane acrylate is prepared by reacting polyester diol, pentaerythritol dimethacrylate, and polyisocyanate to obtain the basic chain segment, and then introducing 1,4-butanediol and hexafluoropentanediol for chain extension, and hydroxyethyl acrylate and 3-tetrahydrofuran methanol for end capping. Compared with directly introducing hydrophobic materials, this application effectively improves hydrophobicity and water vapor resistance through the alkyl segment of polyester diol and the fluorinated segment of hexafluoropentanediol. At the same time, 3-tetrahydrofuran can improve the similarity with the diluent and promote dispersion. Moreover, this unique heterocyclic structure can improve thermal stability and synergistically improve high temperature resistance with the fluorinated segment.

[0020] The silicone-containing polyurethane acrylate is prepared based on dihydroxyl-terminated polydimethylsiloxane, with 3-(trimethylsilyl)-1,2-propanediol introduced as a chain extender and 2-[1-(hydroxymethyl)ethyl]zoline as a capping agent. The polyester diol and pentaerythritol dimethacrylate, which exhibit similar compatibility with fluorinated polyurethane acrylate, effectively improve the interfacial properties of the two substances. Simultaneously, the good hydrophobicity and flexibility of the contained silicon segments effectively improve the adhesive's resistance to moisture and high temperature / humidity. Furthermore, the introduced 2-[1-(hydroxymethyl)ethyl]zoline, with its specific group, reacts with the carboxyl groups generated by hydrolysis when the polyester segments in the adhesive break, forming a stable product. This prevents the chain propagation of the hydrolysis reaction, improves polymer compatibility, and increases the adhesive's strength and resistance to high temperature and humidity. It is important to note that the molecular weight of dihydroxyl-terminated polydimethylsiloxane needs to be limited. Introducing excessively high molecular weights can lead to segregation, affecting interfacial properties and thus reducing adhesive performance.

[0021] Compared to a single polyurethane acrylate, using a blend of fluorinated and silicone polyurethane acrylates can create a "rigid-flexible" interpenetrating network, resulting in a synergistic effect of "fluorine chain surface protection, silicone chain buffering and toughening, and double cross-linking interlocking," while also considering bond strength, durability, and resistance to high temperatures and humidity. However, the ratio of the two needs to be limited; too much silicone polyurethane acrylate can negatively impact overall adhesion.

[0022] To further improve cohesion and enhance the adhesive's bonding properties, this application adds modified nano-silica. This modified silica can uniformly disperse stress, reducing localized stress concentration and thus preventing adhesive layer cracking or delamination. However, since it is not easily dispersed in the adhesive, the solution uses aminated silica for modification, followed by secondary modification with segments similar to polyurethane acrylates. This effectively promotes its dispersibility in the adhesive and allows it to crosslink in a dual network, forming stress dispersion and effectively improving the overall performance of the adhesive. Detailed Implementation

[0023] 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.

[0024] It should be noted that the following quantities are by weight. There are no special restrictions on the manufacturers of any of the raw materials involved in this invention. Exemplary examples include: polybutylene adipate diol with an average molecular weight of 2000; pentaerythritol dimethacrylate (CAS No.: 26846-58-2); isophorone diisocyanate (CAS No.: 4098-71-9); 1,4-butanediol (CAS No.: 110-63-4); hexafluoropentanediol (CAS No.: 376-90-9); hydroxyethyl acrylate (CAS No.: 818-61-1); 3-tetrahydrofuran methanol (CAS No.: 15833-61-1); hydroquinone (CAS No.: 123-31-9); dihydroxy-terminated polydimethylsiloxane with an average molecular weight of 1000; and 3-(trimethylsilyl)-1,2-propanediol (C60-60-9). AS No.: 119235-89-1; CAS No.: 13670-31-0 for 2-[1-(hydroxymethyl)ethyl]zoline; Nano silica, particle size 20~100nm; CAS No.: 919-30-2 for 3-aminopropyltriethoxysilane; CAS No.: 77-58-7 for organotin catalyst, dibutyltin dilaurate; CAS No.: 2399-48-6 for tetrahydrofuran acrylate; CAS No.: 2680-03-7 for N,N-dimethylacrylamide; CAS No.: 2274-11-5 for 1,6-ethylene glycol diacrylate; CAS No.: 30674-80-7 for isocyanate methacrylate; Hexamethylene diisocyanate trimer, NCO content 19.6±3%, provided by Guangzhou Haoyi New Material Technology Co., Ltd.

[0025] In the following embodiments, all of the above-mentioned and other raw materials used but not mentioned are commercially available.

[0026] In the following embodiments and comparative examples, the polyester diol is polybutylene adipate diol; the defoamer is EFKA-2022 defoamer; and the leveling agent is EFKA-3777 leveling agent.

[0027] Example 1: Preparation of UV moisture dual-curing adhesive:

[0028] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0029] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0030] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0031] Step 4: Preparation of Adhesive: 65 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 4:1), 4 parts of tetrahydrofuran acrylate, 6 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 5 parts of isocyanate methacrylate, and 7 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 5 parts of modified silica, 1 part of photoinitiator, 0.3 parts of defoamer, and 0.1 parts of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0032] Example 2: Preparation of UV moisture dual-curing adhesive:

[0033] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0034] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0035] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0036] Step 4: Adhesive preparation: 60 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 3.5:1.5), 3 parts of tetrahydrofuran acrylate, 5 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 4 parts of isocyanate methacrylate, and 6 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 4 parts of modified silica, 1 part of photoinitiator, 0.1 part of defoamer, and 0.1 part of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0037] Example 3: Preparation of UV moisture dual-curing adhesive:

[0038] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0039] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0040] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0041] Step 4: Preparation of Adhesive: 70 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 4:1), 5 parts of tetrahydrofuran acrylate, 7 parts of 1,6-ethylene glycol diacrylate, 20 parts of N,N-dimethylacrylamide, 7 parts of isocyanate methacrylate, and 8 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 6 parts of modified silica, 2 parts of photoinitiator, 0.5 parts of defoamer, and 0.2 parts of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0042] Comparative Example 1: Based on Example 1, a single fluorinated polyurethane acrylate was added to the polyurethane acrylate, while the rest of the process remained unchanged, as follows:

[0043] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0044] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0045] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0046] Step 4: Preparation of adhesive: 65 parts of polyurethane acrylate (fluorinated polyurethane acrylate), 4 parts of tetrahydrofuran acrylate, 6 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 5 parts of isocyanate methacrylate, and 7 parts of hexamethylene diisocyanate trimer are stirred at 600 rpm for 25 min at 45 °C. Then, 5 parts of modified silica, 1 part of photoinitiator, 0.3 parts of defoamer, and 0.1 parts of leveling agent are added sequentially, and the mixture is stirred at 800 rpm for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0047] Comparative Example 2: Based on Example 1, the content of silicone-containing polyurethane acrylate was increased, while the rest of the process remained unchanged, as follows:

[0048] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0049] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0050] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0051] Step 4: Preparation of Adhesive: 65 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 4:3), 4 parts of tetrahydrofuran acrylate, 6 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 5 parts of isocyanate methacrylate, and 7 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 5 parts of modified silica, 1 part of photoinitiator, 0.3 parts of defoamer, and 0.1 parts of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0052] Comparative Example 3: Based on Example 1, the molecular weight of the dihydroxyl-terminated polydimethylsiloxane was increased to 2000 during the preparation of the silicone-containing polyurethane acrylate, while the rest of the process remained unchanged, as follows:

[0053] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0054] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane (molecular weight 2000), 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0055] Step 3: Preparation of modified silica: S1.1: Disperse nano-silica in an 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane at a mass ratio of 1:0.3 to nano-silica, stir at 65℃ for 6h, filter and dry to obtain aminated silica; S1.2: Add 10 parts of aminated silica to 100 parts of N-methylpyrrolidone, add 0.3 parts of organotin catalyst; under a nitrogen atmosphere, add 3 parts of pentaerythritol dimethacrylate, 4 parts of 1,4-butanediol, 44 parts of isophorone diisocyanate, and 2 parts of hexafluoropentanediol, stir and react at 80℃ for 12h, wash and dry to obtain modified silica;

[0056] Step 4: Preparation of Adhesive: 65 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 4:1), 4 parts of tetrahydrofuran acrylate, 6 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 5 parts of isocyanate methacrylate, and 7 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 5 parts of modified silica, 1 part of photoinitiator, 0.3 parts of defoamer, and 0.1 parts of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0057] Comparative Example 4: Based on Example 1, only 3-aminopropyltriethoxysilane was used for nano-silica, while the rest of the process remained unchanged, as follows:

[0058] Step 1: Preparation of fluorinated polyurethane acrylate: Under a nitrogen atmosphere, 175 parts of dehydrated polyester diol and 15 parts of pentaerythritol dimethacrylate were mixed evenly, and 70 parts of isophorone diisocyanate were added at 55°C; the mixture was stirred at 80°C for 1.5 h; 4 parts of 1,4-butanediol and 6 parts of hexafluoropentanediol were added at 45°C, and the mixture was stirred for 0.5 h; 9 parts of hydroxyethyl acrylate, 3 parts of 3-tetrahydrofuran methanol, and 0.2 parts of hydroquinone were added; the mixture was stirred and reacted at 75~90°C for 3.5 h to obtain fluorinated polyurethane acrylate.

[0059] Step 2: Preparation of silicone-containing polyurethane acrylate: Under a nitrogen atmosphere, 80 parts of dehydrated dihydroxy-terminated polydimethylsiloxane, 15 parts of polyester diol, and 10 parts of pentaerythritol dimethacrylate were mixed evenly. 35 parts of isophorone diisocyanate were added at 55°C, and the mixture was stirred at 80°C for 30 minutes. 7 parts of 3-(trimethylsilyl)-1,2-propanediol were added at 45°C, and the mixture was stirred for 0.5 hours. 4 parts of 2-[1-(hydroxymethyl)ethyl]zoline and 4 parts of hydroxyethyl acrylate were added, and the mixture was stirred for another 3 hours to obtain silicone-containing polyurethane acrylate.

[0060] Step 3: Preparation of modified silica: S1.1: Disperse nano silica in 80wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane with a mass ratio of 1:0.3 to nano silica, stir at 65℃ for 6h, filter, wash, and dry to obtain modified silica;

[0061] Step 4: Preparation of Adhesive: 65 parts of polyurethane acrylate (fluorinated polyurethane acrylate and silicone polyurethane acrylate in a mass ratio of 4:1), 4 parts of tetrahydrofuran acrylate, 6 parts of 1,6-ethylene glycol diacrylate, 15 parts of N,N-dimethylacrylamide, 5 parts of isocyanate methacrylate, and 7 parts of hexamethylene diisocyanate trimer are stirred at 600 r / min for 25 min at 45 °C. Then, 5 parts of modified silica, 1 part of photoinitiator, 0.3 parts of defoamer, and 0.1 parts of leveling agent are added sequentially, and the mixture is stirred at 800 r / min for 30 min. Nitrogen gas is then released to obtain a UV moisture-curing adhesive.

[0062] Performance testing: The UV moisture dual-curing adhesives prepared in each embodiment and comparative example were coated and tested. The curing process was as follows: irradiation treatment under a high-pressure mercury lamp with a power of 1000W for 40s, followed by moisture curing in a constant humidity and temperature chamber at a temperature of 25℃ and a relative humidity of 50% for 7d; (1) The samples were treated according to the standard method of GB / T2790, with glass as the rigid material and polyimide film as the flexible material, and the adhesive coating thickness was 0.5mm. The peel strength A was tested; (2) The corresponding samples were placed in an environment with a temperature of 85℃ and a relative humidity of 85% for 500h, and the peel strength B was tested again after removal; and the relevant decrease was calculated. The data are shown in Table 1:

[0063]

[0064] Conclusion: The data in the table above show that the UV moisture dual-curing adhesive prepared by this invention has excellent bonding strength and improved water vapor barrier properties, which can meet its application requirements in high temperature and high humidity environments. However, in Comparative Example 1, the addition of fluorinated polyurethane acrylate alone to the polyurethane acrylate fails to form a "rigid-flexible" interpenetrating network, resulting in decreased adhesion and significant performance degradation under high temperature and high humidity conditions. In Comparative Example 2, the increased content of silicone-containing polyurethane acrylate leads to excessive content and decreased adhesion. In Comparative Example 3, the molecular weight of dihydroxyl-terminated polydimethylsiloxane was increased to 2000, resulting in segregation in the sample, affecting interfacial properties and decreasing adhesiveness. In Comparative Example 4, only 3-aminopropyltriethoxysilane was used for nano-silica, which improved the dispersibility in the adhesive to some extent, but the interfacial properties were generally poor, leading to decreased performance.

[0065] 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-moisture dual-cure adhesive, characterized by: The raw materials of the UV moisture dual-curing adhesive include the following components: 60-70 parts of polyurethane acrylate, 3-5 parts of tetrahydrofuran acrylate, 5-7 parts of 1,6-ethylene glycol diacrylate, 15-20 parts of N,N-dimethyl acrylamide, 4-7 parts of isocyanatoethyl methacrylate, 6-8 parts of hexamethylene diisocyanate trimer, 4-6 parts of modified silica, 1-2 parts of photoinitiator, 0.1-0.5 parts of defoaming agent, and 0.1-0.2 parts of leveling agent; The polyurethane acrylate includes fluorine-containing polyurethane acrylate and silicon-containing polyurethane acrylate in a mass ratio of 3.5-4:1-1.

5. The preparation method of the fluorine-containing polyurethane acrylate is as follows: under a nitrogen atmosphere, after water removal, the polyester diol, pentaerythritol dimethacrylate are uniformly mixed, isophorone diisocyanate is added at 50-55 DEG C, stirring is carried out at 75-90 DEG C for 1-2 hours, 1,4-butanediol and hexafluoropentanediol are added at 40-50 DEG C, stirring is carried out for 0.5-1 hour, hydroxyethyl acrylate, 3-tetrahydrofurfuryl alcohol and hydroquinone are added, stirring is continued at 75-90 DEG C for 3-4 hours, and the fluorine-containing polyurethane acrylate is obtained. The preparation method of the silicon-containing polyurethane acrylate is as follows: under a nitrogen atmosphere, after water removal, the dihydroxyl-terminated polydimethylsiloxane, polyester diol and pentaerythritol dimethacrylate are uniformly mixed, isophorone diisocyanate is added at 50-55 DEG C, stirring is carried out at 75-90 DEG C for 30-40 minutes, 3-(trimethylsilyl)-1,2-propanediol is added at 40-50 DEG C, stirring is carried out for 0.5-1 hour, 2-[1-(hydroxymethyl)ethyl]oxazoline and hydroxyethyl acrylate are added, and stirring is continued for 3-4 hours, and the silicon-containing polyurethane acrylate is obtained. The average molecular weight of the dihydroxyl-terminated polydimethylsiloxane is 1000. The preparation method of the modified silica is as follows: S1.1: nanosilica is dispersed in 80-85 wt% ethanol aqueous solution, amino silane coupling agent is added, stirring is carried out at 60-70 DEG C for 4-8 hours, filtration and drying are carried out, and the aminosilica is obtained; S1.2: the aminosilica is added to N-methyl pyrrolidone, and organotin catalyst is added; under a nitrogen atmosphere, pentaerythritol dimethacrylate, 1,4-butanediol, isophorone diisocyanate and hexafluoropentanediol are added, stirring is carried out at 75-90 DEG C for 10-12 hours, and washing and drying are carried out, and the modified silica is obtained.

2. The UV-moisture dual cure adhesive according to claim 1, characterized in that: The raw materials of the fluorine-containing polyurethane acrylate include the following components: 150-200 parts of polyester diol, 15-20 parts of pentaerythritol dimethacrylate, 3-5 parts of 1,4-butanediol, 5-7 parts of hexafluoropentanediol, 65-75 parts of isophorone diisocyanate, 7-11 parts of hydroxyethyl acrylate, 3-4 parts of 3-tetrahydrofurfuryl alcohol and 0.2-0.3 parts of hydroquinone. The average molecular weight of the polyester diol is 2000-3000; and the polyester diol includes one or both of polybutylene adipate diol and polyhexylene adipate diol.

3. The UV-moisture dual cure adhesive according to claim 1, wherein: The raw materials of the silicon-containing polyurethane acrylate include the following components: 70-85 parts by weight of a dihydroxyl-terminated polydimethylsiloxane, 10-15 parts by weight of a polyester diol, 10-15 parts by weight of pentaerythritol dimethacrylate, 3-5 parts by weight of 3-(trimethylsilyl)-1,2-propanediol, 3-5 parts by weight of 2-[1-(hydroxymethyl)ethyl]oxazoline, 3-5 parts by weight of hydroxyethyl acrylate, and 30-40 parts by weight of isophorone diisocyanate.

4. The UV-moisture dual cure adhesive according to claim 1, wherein: The mass ratio of the nanosilica and the amino silane coupling agent is 1:0.2-0.4; and the raw materials of the modified silica include the following components: 10 parts by weight of aminosilica, 2-3 parts by weight of pentaerythritol dimethacrylate, 10-12 parts by weight of isophorone diisocyanate, 3-5 parts by weight of 1,4-butanediol, 2-3 parts by weight of hexafluoropentanediol, 0.1-0.5 parts by weight of an organic tin catalyst, and 100 parts by weight of N-methylpyrrolidone.

5. The preparation process of the UV-moisture dual-curing adhesive according to any one of claims 1-4, characterized in that: The method includes the following steps: The polyurethane acrylate, tetrahydrofurfuryl acrylate, 1,6-hexanediol diacrylate, N,N-dimethyl acrylamide, isocyanatoethyl methacrylate, and hexamethylene diisocyanate are stirred at 400-800 r / min at 40-50°C for 20-30 min under a nitrogen atmosphere; the modified silica, the photoinitiator, the defoaming agent, and the leveling agent are sequentially added, and stirred at 800-1000 r / min for 30-40 min; nitrogen is released, and a UV moisture dual-curing adhesive is obtained.

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