High-temperature-resistant and high-humidity-resistant flexible ultraviolet curing adhesive as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of adhesive synthesis, and relates to a light-cured adhesive, in particular to a high-temperature-resistant and high-humidity-resistant flexible ultraviolet light-cured adhesive as well as a preparation method and application thereof. The adhesive is prepared by taking a self-made polyurethane acrylate oligomer, trifunctional polyurethane acrylate, a monomer composition and a photoinitiator as main raw materials. The invention relates to a UV (ultraviolet) photoinitiator, which is prepared from the following raw materials in parts by weight: 30 to 45 parts of self-made polyurethane acrylate oligomer, 1 to 5 parts of trifunctional polyurethane acrylate, 45 to 65 parts of monomer composition and 1.5 to 5 parts of photoinitiator, wherein the monomer composition comprises the following components in parts by weight: 30-40 parts of a monomer without containing water-absorbing / polar groups, 10-20 parts of a monomer containing tetrahydrofuran and 5-15 parts of a monomer containing a soft long chain. The water absorption rate of the adhesive ranges from 0.01% to 0.3%, the bonding peel strength is 8 kN / m or above, after high-temperature and high-humidity verification, the bonding peel strength can still be kept at 7.6 kN / m or above, and the bonding peel strength retention rate is 95% or above.

Description

Technical Field

[0001] This invention belongs to the field of adhesive synthesis technology, and relates to a light-curing adhesive, particularly a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive and its preparation method and application. Background Technology

[0002] Medical devices transported across continents often encounter harsh environments such as high temperature and humidity or large temperature fluctuations. When traversing tropical waters, the interior of containers frequently experiences a combination of temperatures exceeding 40°C and humidity reaching 95%. During trans-latitude transport between the Northern and Southern Hemispheres, drastic temperature fluctuations ranging from -10°C to 45°C are common. Medical devices (such as anesthesia catheters, infusion tubing, and breathing lines) are continuously subjected to humid heat, which weakens the bond strength of adhesive joints and increases the risk of leakage. Implantable medical devices (such as endotracheal tubes and orthopedic implant components) need to operate stably for extended periods in the physiological environment of the human body at a constant temperature of 37°C, rich in moisture and electrolytes. Adhesives used for bonding may delaminate or hydrolyze, weakening the bond strength. Therefore, developing high-temperature and high-humidity resistant adhesives is crucial to solving these problems.

[0003] Thermoplastic polyurethane (TPU) is a commonly used material in medical devices due to its excellent elasticity, toughness, and biocompatibility. However, its low surface energy makes it difficult to bond, limiting its use. Furthermore, medical devices often require operation in high-temperature and high-humidity environments, and TPU is prone to heat deformation at high temperatures. Adhesives used to bond TPU often lack flexibility, leading to peeling and bond failure. Therefore, the bonding problems of TPU are particularly prominent.

[0004] Patent document CN114874743B discloses a high-adhesion UV-curable polyurethane adhesive and its preparation method. While this method improves the adhesive strength and hydrolysis resistance to some extent through optimized selection of polyurethane acrylate raw materials, the high proportion of easily hydrolyzed groups such as ether and ester bonds in its molecular chain means that the adhesive's performance may be affected under relatively harsh high-temperature and high-humidity environments. After a certain period of aging, the adhesive strength may decrease significantly, limiting its applicability in environments requiring high resistance to damp heat and long-term exposure to high temperatures and humidity. Furthermore, the substrates it bonds to are polyimide films and glass. These two materials have higher surface energy than thermoplastic polyurethane and are less prone to deformation, posing a significant risk when used for bonding thermoplastic polyurethane materials.

[0005] Patent document CN112143442B discloses a water-resistant and high-temperature-resistant mixed acrylate flexible ultraviolet light curing adhesive and its preparation method. The adhesive uses self-made cationic radical mixed light curing acrylate resin and other components to achieve excellent adhesion to plastics and flexibility of the cured adhesive. The adhesive is used to bond ABS test pieces and PC material small test blocks, and the shear strength is tested. The substrate does not deform obviously, and the surface energy is higher than that of thermoplastic polyurethane material. At the same time, due to the high activity of the residual small molecule monomers in the system at high temperature, migration is easy to occur, which leads to cracking of the adhesive, and then the adhesion decreases, affecting the normal use and service life of the product.

[0006] In summary, it is urgent to develop a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive for thermoplastic polyurethane materials. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive and its application. The adhesive has excellent high-temperature and high-humidity resistance and is suitable for bonding thermoplastic polyurethane materials. The present application also provides a preparation method of the adhesive, which is simple and easy to implement and can be mass-produced industrially.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application provides a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive, which comprises the following raw materials: 30-45 parts of polyurethane acrylate oligomer, 1-5 parts of trifunctional polyurethane acrylate, 45-65 parts of monomer composition, and 1.5-5 parts of photoinitiator; the monomer composition comprises 30-40 parts of water-absorbing / polar group-free monomer, 10-20 parts of tetrahydrofuran-containing monomer, and 5-15 parts of soft long-chain monomer; the raw materials are by weight.

[0009] Further, the polyurethane acrylate oligomer is prepared by using polyester polyol and benzene ring-containing diisocyanate as polymerization raw materials, low molecular weight polyethylene glycol as a chain extender, alkoxyphenol as a stabilizer, hydroxy ester as an active diluent, and dibutyltin dilaurate as a catalyst under solvent conditions through heating reaction; the molar ratio of the polyester polyol to the benzene ring-containing diisocyanate is 1:2-2.3, the molar ratio of the low molecular weight polyethylene glycol to the benzene ring-containing diisocyanate is 1:9.5-10, the molar ratio of the hydroxy ester to the polyester polyol is 1:1-1.3, and the addition amount of the dibutyltin dilaurate and the alkoxyphenol is 0.01wt%-0.03wt% of the total system.

[0010] Further, the preparation process of the polyurethane acrylate oligomer is as follows: the benzene ring containing diisocyanate, dibutyltin dilaurate and solvent are added into a reaction container in proportion, heated to 40±2℃, the low molecular weight polyethylene glycol is added for chain extension, heated to 60±2℃ and reacted for 2±0.5 hours; then the polyester polyol is added, heated to 70±2℃ and reacted for 2±0.5 hours; finally, heated to 80±2℃, the alkoxyphenol and hydroxy ester are added, and reacted for 3±1.5 hours.

[0011] Further, the polyester polyol comprises a polycaprolactone diol, the polycaprolactone diol is prepared by using ε-caprolactone and diethylene glycol (DEG) or triethylene glycol (TEG) as raw materials in a molar ratio of 3.8~4.1:1, using stannous octoate as a catalyst, controlling the reaction temperature at 130~180℃, and reacting for 5h under the condition of nitrogen purging, and then removing the volatile components by vacuum to obtain the polycaprolactone diol; the molar ratio of the stannous octoate to the diethylene glycol (DEG) or triethylene glycol (TEG) is 0.18~0.22:1.

[0012] Further, the ε-caprolactone is used after pretreatment, and the pretreatment condition is as follows: vacuum dehydration at 85±1℃ for 30~40 minutes.

[0013] Further, the benzene ring containing diisocyanate comprises toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI); the polyol comprises triethylene glycol (TEG), the alkoxyphenol comprises p-hydroxyanisole (MEHQ), the hydroxy ester comprises hydroxyethyl acrylate (HEA), and the solvent comprises ethyl acetate.

[0014] Further, the trifunctional polyurethane acrylate is preferably HM-5077 of Jiangxi Kunlong New Material Co., Ltd.; and the photoinitiator comprises any one or more of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester, and 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide.

[0015] Further, the non-water-absorbing / polar group-containing monomer includes any one or more of isobornyl acrylate (IBOA), isobornyl methacrylate (IBOMA), dicyclopentenyl acrylate (DCPA), 3,3,5-trimethylcyclohexyl acrylate (TBCHA), and dicyclopentane methacrylate (HDCPMA); the tetrahydrofuran-containing monomer includes tetrahydrofurfuryl acrylate (THFA) and / or tetrahydrofurfuryl methacrylate (THFMA); and the soft long-chain-containing monomer includes any one or more of isodecyl acrylate (ISODA), isodecyl methacrylate (IDMA), ethoxyethoxyethyl acrylate (EOEOEA), lauryl acrylate (LA), lauryl methacrylate (LMA), and stearyl acrylate (SA).

[0016] Further, the high-temperature and high-humidity-resistant flexible ultraviolet light-cured adhesive has a Shore hardness of 83A to 95A after curing, a water absorption of 0.01% to 0.3%, and an elongation at break of more than 241%.

[0017] The application further provides a preparation method of the high-temperature and high-humidity-resistant flexible ultraviolet light-cured adhesive. S1, under the condition of a stirring speed of 200-300 rpm, the stirring time is controlled to be 10-20 min, the non-water-absorbing / polar group-containing monomer, the soft long-chain-containing monomer, and the tetrahydrofuran-containing monomer are uniformly mixed in proportion to obtain a monomer composition; S2, under the condition of a stirring speed of 300-500 rpm, the stirring time is controlled to be 30-60 min, the polyurethane acrylate oligomer, the trifunctional polyurethane acrylate, and the monomer composition in S1 are uniformly mixed in proportion to obtain a base glue; S3, the photoinitiator is added to the base glue in S2 in proportion, and is uniformly mixed under the condition of a stirring speed of 200-400 rpm and a stirring time of 30-40 min; the system is left to stand or vacuumized to remove bubbles in the system, thereby preparing the high-temperature and high-humidity-resistant flexible ultraviolet light-cured adhesive; the vacuum degree of the vacuumization is-0.05 to-0.1 MPa, and the vacuum time is 20-90 min.

[0018] The application further provides an application of the high-temperature and high-humidity-resistant flexible ultraviolet light-cured adhesive in bonding of medical instrument products.

[0019] Further, the material of the medical instrument product includes a thermoplastic polyurethane material; the peel strength of the thermoplastic polyurethane material after bonding is more than 8 kN / m, the bonding peel strength can still be maintained to be more than 7.6 kN / m after high-temperature and high-humidity verification, and the bonding peel strength retention rate is more than 95%.

[0020] Further, the medical instrument product includes a tracheal tube, a catheter, a negative pressure sealing drainage device, or the like.

[0021] The beneficial effects of the present application are: 1. The high-temperature and high-humidity resistant flexible ultraviolet light-cured adhesive provided by the present application can be applied to the bonding of thermoplastic polyurethane materials with low surface energy and good flexibility, and can meet the use requirements in high-temperature and high-humidity environments. Specifically, the adhesive bonding peel strength with thermoplastic polyurethane materials is above 8kN / m, and after high-temperature and high-humidity verification, the adhesive bonding peel strength can still be maintained above 7.6kN / m, and the adhesive bonding peel strength retention rate is above 95%.

[0022] 2. The high-temperature and high-humidity resistant flexible ultraviolet light-cured adhesive provided by the present application contains a self-prepared polyurethane acrylate oligomer in the raw materials, the oligomer is polymerized from soft long-chain polyester polyol and diisocyanate containing benzene ring, has low surface tension, and can fully infiltrate the surface of thermoplastic polyurethane materials; the monomer containing tetrahydrofuran group is used, which can produce micro-etching and micro-dissolution effect on the surface of thermoplastic polyurethane, enhance the mutual penetration between the adhesive and the substrate interface, and thus ensure the bonding performance of thermoplastic polyurethane materials.

[0023] 3. The high-temperature and high-humidity resistant flexible ultraviolet light-cured adhesive provided by the present application contains a self-prepared polyurethane acrylate oligomer in the raw materials, the oligomer is polymerized from soft long-chain polyester polyol and diisocyanate containing benzene ring, soft long-chain polyol is the soft segment, has good flexibility, and is not easy to produce interface separation when applied to the bonding of thermoplastic polyurethane materials due to different degrees of deformation; diisocyanate containing benzene ring is the hard segment, and the substance containing benzene ring in the molecular chain segment can improve the high-temperature resistance of the adhesive.

[0024] The use of trifunctional polyurethane acrylate increases the crosslinking point and improves the crosslinking density, which can make the whole molecular network structure more compact and solid, thereby improving the high-humidity resistance of the adhesive. The monomers such as isobornyl acrylate (IBOA), isobornyl methacrylate (IBOMA), and dicyclopentenyl acrylate (DCPA) do not contain water-absorbing / polar groups, are cycloalkane acrylates with excellent water resistance, and can ensure the performance of the adhesive in high-humidity state.

[0025] 4. The high-temperature and high-humidity resistant flexible ultraviolet light-cured adhesive provided by the present application realizes the high-strength bonding of thermoplastic polyurethane materials in high-temperature and high-humidity environments through the molecular structure design of the self-prepared polyurethane acrylate oligomer, the introduction of trifunctional polyurethane acrylate, and the functional optimization of the monomer composition, and the synergistic effect of the three aspects.

[0026] 5. The method for preparing the high-temperature and high-humidity resistant flexible ultraviolet light cured adhesive provided by the application is simple and easy to implement, and can be used for large-scale industrial production.

[0027] 6. The high-temperature and high-humidity resistant flexible ultraviolet light cured adhesive provided by the application can be well applied in the bonding of medical device products, especially the bonding of products such as tracheal tubes, indwelling needles or negative pressure sealing drainage devices made of thermoplastic polyurethane. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings described in the following embodiments are only some embodiments of the application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0029] ATTACHMENT Figure 1 The reaction equation for preparing the self-made polyurethane acrylate oligomer in the high-temperature and high-humidity resistant flexible ultraviolet light cured adhesive provided by the application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be clearly and completely described below. The embodiments mentioned are implemented on the premise of the technical solutions of the application, and a detailed implementation process is given, but it needs to be declared that the protection scope of the application is not limited to the following embodiments.

[0031] The following embodiments are directed to the technical solutions of the application, and detailed embodiment processes are listed. In the following experimental examples, the experimental methods are conventional methods unless otherwise specified; and the materials, reagents and the like are commercially available unless otherwise specified.

[0032] Embodiment 1 A high-temperature and high-humidity resistant flexible ultraviolet light cured adhesive is prepared by the following steps: (1) Preparation of self-made polyurethane acrylate oligomer (reaction equation as shown in Figure 1 The following steps are taken: 4.57 g (40 mmol) of ε-caprolactone is weighed and added to a polymerization reactor, the temperature is raised to 85°C, and the ε-caprolactone is vacuum-dried for 30 min by starting a vacuum pump; 1.06 g (10 mmol) of diethylene glycol (DEG) and 0.44 g (2 mmol) of catalyst stannous octoate are added, the reaction temperature is 180°C, and the reaction is carried out for 5 h under nitrogen blowing, and then the volatile components are removed by vacuum extraction to obtain a polycaprolactone diol.

[0033] In a four-necked glass flask equipped with mechanical stirring, thermometer, condenser and constant pressure dropping funnel, add toluene diisocyanate (TDI, 6.97 g, 40 mmol), dibutyltin dilaurate (DBTDL, 0.018 g, 0.03 mmol) and ethyl acetate (20 g), heat to 40 °C. Add 0.60 g (4 mmol) of triethylene glycol (TEG) chain extender, heat to 60 °C for 2 h, then add 50 g (20 mmol) of polycaprolactone diol, heat to 70 °C for 2 h, and finally, heat to 80 °C, add p-hydroxyanisole (MEHQ, 0.009 g, 0.07 mmol) and hydroxyethyl acrylate (HEA, 2.32 g, 20 mmol), and react for 3 h to obtain a self-made polyurethane acrylate oligomer.

[0034] (2) Preparation of the ultraviolet light curing adhesive: Step A: Mix 35 parts of isobornyl acrylate (IBOA), 10 parts of isodecyl acrylate (ISODA) and 20 parts of tetrahydrofurfuryl acrylate (THFA) to obtain a monomer composition by stirring at a speed of 300 rpm for 20 min; then mix the monomer composition with 30 parts of the self-made polyurethane acrylate oligomer in step (1) and 1 part of trifunctional polyurethane acrylate HM-5077 by stirring at a speed of 500 rpm for 60 min to obtain a base glue.

[0035] Step B: Add 4 parts of photoinitiator 1-hydroxycyclohexyl phenyl ketone to the base glue prepared in step A, and mix and stir uniformly at a speed of 200 rpm for 40 min; vacuumize at a vacuum degree of (-0.1) MPa for 90 min to remove bubbles in the system, to obtain a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0036] Example 2 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive is prepared by the following steps: Step (1) is the same as in Example 1, except that "toluene diisocyanate (TDI, 6.97 g, 40 mmol)" is changed to "diphenylmethane diisocyanate (MDI, 10.01 g, 40 mmol)".

[0037] (2) Preparation of the ultraviolet light curing adhesive: Step A: 35 parts of isobornyl acrylate (IBOA), 10 parts of isodecyl acrylate (ISODA) and 18 parts of tetrahydrofurfuryl acrylate (THFA) were mixed, and stirred at a stirring speed of 300 rpm for 20 min to obtain a monomer composition; 30 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred at a stirring speed of 500 rpm for 60 min to obtain a base glue.

[0038] Step B: 4 parts of a photoinitiator 1-hydroxycyclohexyl phenyl ketone was added to the base glue prepared in step A, and stirred at a stirring speed of 200 rpm for 40 min; the system was vacuumed at a vacuum degree of (-0.1) Mpa for 90 min to remove the bubbles in the system, thereby obtaining a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0039] Example 3 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) was the same as that in Example 1.

[0040] (2) Preparation of the ultraviolet light curing adhesive: Step A: 35 parts of isobornyl acrylate (IBOA), 10 parts of isodecyl acrylate (ISODA) and 18 parts of tetrahydrofurfuryl acrylate (THFA) were mixed, and stirred at a stirring speed of 300 rpm for 20 min to obtain a monomer composition; 30 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred at a stirring speed of 500 rpm for 60 min to obtain a base glue.

[0041] Step B: 4 parts of a photoinitiator 1-hydroxycyclohexyl phenyl ketone was added to the base glue prepared in step A, and stirred at a stirring speed of 200 rpm for 40 min; the system was vacuumed at a vacuum degree of (-0.1) Mpa for 90 min to remove the bubbles in the system, thereby obtaining a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0042] Example 4 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) was the same as that in Example 1, except that the “reaction temperature 180℃” was changed to “reaction temperature 170℃”.

[0043] (2) Preparation of the ultraviolet light curing adhesive: Step A: 35 parts of isobornyl methacrylate (IBOMA), 5 parts of isodecyl methacrylate (IDMA) and 14 parts of tetrahydrofurfuryl acrylate (THFA) were mixed, and stirred at a stirring speed of 250 rpm for 15 min to obtain a monomer composition; 40 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred at a stirring speed of 400 rpm for 50 min to obtain a base glue.

[0044] Step B: 3 parts of a photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide was added to the base glue prepared in step A, and stirred at a stirring speed of 300 rpm for 30 min; the system was vacuumed at a vacuum degree of (-0.08) Mpa for 60 min to remove bubbles, thereby obtaining a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0045] Example 5 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Steps (1) and (2) were the same as those in Example 4, except that "toluene diisocyanate (TDI, 6.97 g, 40 mmol)" was changed to "diphenyl methane diisocyanate (MDI, 10.01 g, 40 mmol)".

[0046] Example 6 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) was the same as that in Example 5.

[0047] (2) Preparation of the ultraviolet light curing adhesive: Step A: 40 parts of isobornyl methacrylate (IBOMA), 5 parts of isodecyl methacrylate (IDMA) and 10 parts of tetrahydrofurfuryl acrylate (THFA) were mixed, and stirred at a stirring speed of 250 rpm for 15 min to obtain a monomer composition; 40 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred at a stirring speed of 400 rpm for 50 min to obtain a base glue.

[0048] Step B: 2 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide was added into the base glue prepared in step A, mixed and stirred uniformly at a stirring speed of 300 rpm for 30 min; vacuum was applied at a vacuum degree of (-0.08) Mpa for 60 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant ultraviolet light curable adhesive.

[0049] Example 7 A high-temperature and high-humidity resistant flexible ultraviolet light curable adhesive was prepared by the following steps: Step (1) was the same as that in Example 4.

[0050] (2) Preparation of the ultraviolet light curable adhesive: Step A: 40 parts of isobornyl methacrylate (IBOMA), 5 parts of isodecyl methacrylate (IDMA) and 10 parts of tetrahydrofurfuryl acrylate (THFA) were mixed and stirred uniformly at a stirring speed of 250 rpm for 15 min, thereby obtaining a monomer composition; 40 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 and the monomer composition were mixed in proportion, and stirred uniformly at a stirring speed of 400 rpm for 50 min, thereby obtaining a base glue.

[0051] Step B: 2 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide was added into the base glue prepared in step A, mixed and stirred uniformly at a stirring speed of 300 rpm for 30 min; vacuum was applied at a vacuum degree of (-0.08) Mpa for 60 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant flexible ultraviolet light curable adhesive.

[0052] Example 8 A high-temperature and high-humidity resistant flexible ultraviolet light curable adhesive was prepared by the following steps: Step (1) was the same as that in Example 4.

[0053] (2) Preparation of the ultraviolet light curable adhesive: Step A: 30 parts of isobornyl methacrylate (IBOMA), 15 parts of isodecyl methacrylate (IDMA) and 10 parts of tetrahydrofurfuryl acrylate (THFA) were mixed and stirred uniformly at a stirring speed of 250 rpm for 15 min, thereby obtaining a monomer composition; 40 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 and the monomer composition were mixed in proportion, and stirred uniformly at a stirring speed of 400 rpm for 50 min, thereby obtaining a base glue.

[0054] Step B: 2 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide was added to the base glue prepared in step A, mixed and stirred uniformly at a stirring speed of 300 rpm for 30 min; vacuum was applied at a vacuum degree of (-0.08) Mpa for 60 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0055] Example 9 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) was the same as that in Example 4.

[0056] (2) Preparation of the ultraviolet light curing adhesive: Step A: 30 parts of isobornyl methacrylate (IBOMA), 5 parts of isodecyl methacrylate (IDMA) and 20 parts of tetrahydrofurfuryl acrylate (THFA) were mixed and stirred uniformly at a stirring speed of 250 rpm for 15 min, thereby obtaining a monomer composition; 40 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred uniformly at a stirring speed of 400 rpm for 50 min, thereby obtaining a base glue.

[0057] Step B: 2 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide was added to the base glue prepared in step A, mixed and stirred uniformly at a stirring speed of 300 rpm for 30 min; vacuum was applied at a vacuum degree of (-0.08) Mpa for 60 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive.

[0058] Example 10 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) and step (2) were the same as those in Example 4, except that the “reaction temperature 180℃” was changed to “reaction temperature 150℃”.

[0059] Example 11 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) and step (2) were the same as those in Example 10, except that the “toluene diisocyanate (TDI, 6.97 g, 40 mmol)” was changed to “diphenylmethane diisocyanate (MDI, 10.01 g, 40 mmol)”.

[0060] Example 12 A high-temperature and high-humidity resistant flexible ultraviolet light curing adhesive was prepared by the following steps: Step (1) is the same as Example 10.

[0061] (2) Preparation of the UV-curable adhesive: Step A: 30 parts of 3,3,5-trimethylcyclohexyl acrylate (TBCHA), 10.5 parts of ethoxyethoxyethyl acrylate (EOEOEA) and 10 parts of tetrahydrofurfuryl methacrylate (THFMA) were mixed, and stirred uniformly at a stirring speed of 200 rpm for 10 min. Then 45 parts of the self-made polyurethane acrylate oligomer in step (1), 3 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred uniformly at a stirring speed of 300 rpm for 40 min to obtain the base glue.

[0062] Step B: 1.5 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide was added to the base glue prepared in step A, and stirred uniformly at a stirring speed of 200 rpm for 30 min. Then the system was vacuumed at a vacuum degree of (-0.07) Mpa for 40 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant flexible UV-curable adhesive.

[0063] Example 13 A high-temperature and high-humidity resistant flexible UV-curable adhesive was prepared by the following steps: Step (1) is the same as Example 11.

[0064] (2) Preparation of the UV-curable adhesive: Step A: 30 parts of 3,3,5-trimethylcyclohexyl acrylate (TBCHA), 12 parts of ethoxyethoxyethyl acrylate (EOEOEA) and 10 parts of tetrahydrofurfuryl methacrylate (THFMA) were mixed, and stirred uniformly at a stirring speed of 200 rpm for 10 min. Then 45 parts of the self-made polyurethane acrylate oligomer in step (1), 1.5 parts of trifunctional polyurethane acrylate HM-5077 were mixed with the monomer composition in proportion, and stirred uniformly at a stirring speed of 300 rpm for 40 min to obtain the base glue.

[0065] Step B: 1.5 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide was added to the base glue prepared in step A, and stirred uniformly at a stirring speed of 200 rpm for 30 min. Then the system was vacuumed at a vacuum degree of (-0.07) Mpa for 40 min to remove the bubbles in the system, thereby preparing a high-temperature and high-humidity resistant flexible UV-curable adhesive.

[0066] Example 14 A kind of high temperature and high humidity resistant flexible UV-curable adhesive is prepared by the following steps: Steps (1) and (2) are the same as Example 12, except that the "reaction temperature 180℃" is changed to "reaction temperature 130℃".

[0067] Example 15 A kind of high temperature and high humidity resistant flexible UV-curable adhesive is prepared by the following steps: Steps (1) and (2) are the same as Example 13, except that the "reaction temperature 180℃" is changed to "reaction temperature 130℃".

[0068] Example 16 A kind of high temperature and high humidity resistant flexible UV-curable adhesive is prepared by the following steps: Step (1) is the same as Example 14.

[0069] Step (2) preparation of UV-curable adhesive: Step A: 30 parts of dicyclopentane methyl methacrylate (HDCPMA), 7 parts of lauryl methacrylate (LMA) and 12 parts of tetrahydrofurfuryl methacrylate (THFMA) are mixed, stirred at a stirring speed of 200 rpm for 15 min to obtain a monomer composition; then 45 parts of the self-made polyurethane acrylate oligomer in step (1), 1 part of trifunctional polyurethane acrylate HM-5077 are mixed with the monomer composition in proportion, stirred at a stirring speed of 300 rpm for 30 min to obtain a base glue.

[0070] Step B: 5 parts of photoinitiator 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide are added to the base glue prepared in step A, mixed and stirred at a stirring speed of 200 rpm for 30 min; vacuum is applied at a vacuum degree of (-0.05) Mpa for 20 min to remove bubbles in the system, to obtain a high temperature and high humidity resistant flexible UV-curable adhesive.

[0071] Comparative Example 1 A kind of adhesive is prepared by the following steps: Steps (1) and (2) are the same as Example 4, except that the "self-made polyurethane acrylate oligomer" in step (2) is changed to "DR-U379 (purchased polyurethane acrylate oligomer)".

[0072] Comparative Example 2 A kind of adhesive is prepared by the following steps: Steps (1) and (2) are the same as Example 4, except that the "self-made polyurethane acrylate oligomer" in step (2) is changed to "HM-2528 (purchased polyurethane acrylate oligomer)".

[0073] Examples The properties of the adhesives prepared in Examples 1-16 and Comparative Examples 1-2 of the present application are as follows: Water absorption: The water absorption test was carried out according to GB / T 1034-2008 "Plastics - Determination of water absorption".

[0074] The sample was placed in a 50.0°C ± 2.0°C oven for at least 24 h, then cooled to room temperature in a desiccator, and each sample was weighed to the nearest 0.1 mg (mass ml). This step was repeated until the mass of the sample varied within ± 0.1 mg. The sample was placed in a container with distilled water, and the water temperature was controlled at 23.0°C ± 1.0°C or 23.0°C ± 2.0°C according to the relevant standard. If there was no relevant standard, the tolerance was ± 1.0°C.

[0075] After soaking for 24 h ± 1 h, the sample was removed, and all water on the surface of the sample was quickly wiped off with a clean dry cloth or filter paper. Each sample was weighed again to the nearest 0.1 mg (mass m2). The weighing should be completed within 1 min after the sample was removed from the water. The water absorption mass fraction of each sample relative to the initial mass was calculated using the following formula: Hardness: The sample cured according to the light curing conditions selected in the experiment was tested for hardness according to GB / T 2411-2008 "Plastics and ebonite - Determination of indentation hardness by durometer (Shore hardness)". The durometer used was Shore A, and the applied load was 5.00 kg ± 0.01 kg for 1 s.

[0076] Tensile strength and elongation at break: The sample cured according to the light curing conditions selected in the experiment was tested for tensile strength and elongation at break according to the test conditions specified in GB / T 1040.2-2006 "Determination of tensile properties of plastics - Part 2: Moulded and extruded plastics". The sample was 80 mm x 10 mm x 2 mm; the test speed (empty load) was 50 mm / min ± 5 mm / min; and the gauge length was 40 mm.

[0077] Peeling strength: The peeling strength test was carried out according to GB / T 2791-1995 "Adhesives - T-peel strength test method - Flexible material to flexible material". A TPU sample piece with a size of 200 mm x 100 mm was bonded to form an enlarged sample, and then the sample was cut from the enlarged sample piece, with a size of 25 mm x 170 mm.

[0078] Firstly, the adhesive tape is pasted, then the two 200*100mm TPU samples are pasted with alcohol, one of which is placed on the flat plate with the pasting surface upwards, fixed with the adhesive tape, and the UV glue is poured on the sample, which is evenly dispersed with the tool, and after 5min natural leveling, the other TPU sample is gently covered from one side to prevent bubbles, and the TPU sample is fixed with the adhesive tape to prevent sliding. After waiting for 5min natural leveling, place it under the surface light source for curing, the curing time is 60s, and the curing power is 100%. After curing, the sample is cut from the expanded sample, marked, and the average thickness of the adhesive layer of the sample is about 0.5mm.

[0079] Then, after adjusting at 80.0℃±1.0℃ and 80±10 RH% for 720h, the peel strength is tested.

[0080] The performance test results are shown in Table 1.

[0081] Table 1 Performance test results of adhesive samples Examples Hardness (A / S) Elongation at break (%) Tensile strength (Mpa) Water absorption (%) Peel strength (kN / m) Peel strength after double 80 (kN / m) Example 1 85 399.87 4.92 0.20 8.51 8.25 Example 2 89 394.82 5.71 0.13 8.33 8.01 Example 3 93 266.06 7.92 0.04 8.20 7.79 Example 4 90 388.25 5.93 0.15 12.86 12.47 Example 5 93 335.37 6.77 0.13 12.21 11.84 Example 6 91 376.77 5.99 0.08 9.84 9.45 Example 7 90 374.51 5.44 0.05 9.90 9.50 Example 8 83 385.48 4.39 0.09 9.12 8.67 Example 9 95 257.76 8.05 0.25 9.97 9.47 Example 10 92 278.40 6.44 0.17 11.98 11.74 Example 11 94 271.88 7.71 0.13 10.30 9.89 Example 12 89 282.84 6.26 0.17 9.95 9.66 Example 13 86 297.20 5.08 0.21 9.07 8.80 Example 14 94 241.17 7.11 0.19 8.06 7.73 Example 15 95 244.09 7.24 0.23 8.21 8.04 Example 16 91 251.69 6.42 0.25 8.66 8.31 Comparative Example 1 85 383.66 5.08 0.90 4.42 2.23 Comparative Example 2 96 224.59 8.15 0.58 6.72 4.97 According to the analysis of the test results in Table 1, the high-temperature and high-humidity resistant flexible ultraviolet curing adhesive provided by the application has high bonding strength and good high-temperature and high-humidity resistance. Specifically, the adhesive provided by the application has the following advantages: The hardness of the adhesive of Examples 1-16 after curing is between 83A and 95A, the water absorption rate is between 0.01% and 0.3%, and the elongation at break is more than 241%. The peel strength of the thermoplastic polyurethane sample is more than 8kN / m, and after the double eighty high-temperature and high-humidity verification, the peel strength can still maintain more than 7.6kN / m, and the peel strength retention rate is more than 95%.

[0082] The peel strength of the adhesive of Comparative Examples 1 and 2 for bonding thermoplastic polyurethane is only 4.42kN / m and 6.72kN / m, and due to the high water absorption rate of 0.90% and 0.58%, the peel strength decreases significantly after the double eighty treatment, and the peel strength retention rate is 51% and 74% respectively.

[0083] The comparison of the above data proves that the light-curing adhesive prepared from the self-made polyurethane acrylate oligomer has better bonding and high temperature and high humidity resistance to the thermoplastic polyurethane than the light-curing adhesive prepared from the purchased polyurethane acrylate oligomer. This is because, first, the self-made polyurethane acrylate oligomer is polymerized from polyethylene glycol with long alkane chain and high molecular weight and diisocyanate, and has lower surface tension and can fully infiltrate the surface of the thermoplastic polyurethane material; second, the polyethylene glycol with high molecular weight has a flexible long chain and is not easy to generate internal stress at the interface during the deformation of the thermoplastic polyurethane; at the same time, the acrylate monomer containing a tetrahydrofuran group is used, which can produce micro-etching and micro-dissolution on the surface of the thermoplastic polyurethane, thereby improving the adhesion of the adhesive layer to the bonded material; finally, the polyethylene glycol with long alkane chain and high molecular weight and the diisocyanate containing a benzene ring, in cooperation with the monomer not containing water-absorbing / polar groups, give the adhesive good humidity resistance and high temperature resistance.

[0084] The above description of disclosed embodiments enables one skilled in the art to make or use the application. Numerous modifications to these embodiments will be apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-temperature and high-humidity resistant flexible UV-curable adhesive, characterized in that, The raw materials include: 30-45 parts of polyurethane acrylate oligomer, 1-5 parts of trifunctional polyurethane acrylate, 45-65 parts of monomer composition, and 1.5-5 parts of photoinitiator; the monomer composition includes 30-40 parts of monomer without water-absorbing / polar groups, 10-20 parts of monomer containing tetrahydrofuran, and 5-15 parts of monomer containing soft long-chain monomer; the raw materials are in parts by weight.

2. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 1, characterized in that, The polyurethane acrylate oligomer is prepared by heating under solvent conditions using polyester polyol and benzene ring-containing diisocyanate as polymerization raw materials, polyethylene glycol as chain extender, alkoxyphenol as stabilizer, hydroxy ester as reactive diluent, and dibutyltin dilaurate as catalyst. The molar ratio of polyester polyol to benzene ring-containing diisocyanate is 1:2~2.3, the molar ratio of polyethylene glycol to benzene ring-containing diisocyanate is 1:9.5~10, the molar ratio of hydroxy ester to polyester polyol is 1:1~1.3, and the addition amount of dibutyltin dilaurate and alkoxyphenol is 0.01wt%~0.03wt% of the total system mass.

3. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 2, characterized in that, The preparation process of the polyurethane acrylate oligomer is as follows: diisocyanate containing benzene ring, dibutyltin dilaurate and solvent are added to a reaction vessel in proportion, the temperature is raised to 40±2℃, oligoethylene glycol is added for chain extension, the temperature is raised to 60±2℃ and reacted for 2±0.5 hours; then polyester polyol is added, the temperature is raised to 70±2℃ and reacted for 2±0.5 hours; finally, the temperature is raised to 80±2℃, alkoxyphenol and hydroxy ester are added, and the reaction is carried out for 3±1.5 hours to obtain the product.

4. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 2, characterized in that, The polyester polyol includes polycaprolactone diol, which is prepared by reacting ε-caprolactone and diethylene glycol or triethylene glycol in a molar ratio of 3.8 to 4.1:1, using stannous octoate as a catalyst, controlling the reaction temperature at 130 to 180°C, reacting for 5 hours under nitrogen purging conditions, and then removing volatile components under vacuum; the molar ratio of stannous octoate to diethylene glycol or triethylene glycol is 0.18 to 0.22:

1.

5. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 2, characterized in that, The benzene ring-containing diisocyanate includes toluene diisocyanate and / or diphenylmethane diisocyanate; the oligoethylene glycol includes triethylene glycol; the alkoxyphenol includes p-hydroxyanisole; the hydroxy ester includes hydroxyethyl acrylate; and the solvent includes ethyl acetate.

6. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 1, characterized in that, The photoinitiator includes any one or more of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

7. The high-temperature and high-humidity resistant flexible UV-curable adhesive as described in claim 1, characterized in that, The monomers free of hygroscopic / polar groups include any one or more of isoborneol acrylate, isoborneol methacrylate, dicyclopentenyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, and dicyclopentyl methacrylate; the monomers containing tetrahydrofuran include tetrahydrofurfuryl acrylate and / or tetrahydrofurfuryl methacrylate; the monomers containing soft long chains include any one or more of isodecyl acrylate, isodecyl methacrylate, ethoxyethoxyethyl acrylate, laurate acrylate, laurate methacrylate, and stearate acrylate.

8. A method for preparing the high-temperature and high-humidity resistant flexible UV-curable adhesive according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1, the monomer composition is obtained by mixing the monomer without water-absorbing / polar groups, the monomer containing soft long chains and the monomer containing tetrahydrofuran in a certain proportion; S2, the polyurethane acrylate oligomer, the trifunctional polyurethane acrylate and the monomer composition in S1 are mixed in proportion to obtain the base adhesive. S3, add the photoinitiator to the base adhesive described in S2 in proportion and mix well; remove air bubbles in the system by standing or vacuuming to prepare a high-temperature and high-humidity resistant flexible UV-curable adhesive.

9. The application of the high-temperature and high-humidity resistant flexible UV-curable adhesive according to any one of claims 1 to 7 in the bonding of medical device products.

10. The application of the high-temperature and high-humidity resistant flexible UV-curable adhesive as described in any one of claims 1 to 7, as described in claim 9, in the bonding of medical device products, characterized in that, The medical device products are made of thermoplastic polyurethane.

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