Efficient environment-friendly adhesive for automobile air conditioner pipe as well as preparation method and application of efficient environment-friendly adhesive

Abstract

The invention discloses an efficient environment-friendly adhesive for an automobile air conditioner pipe as well as a preparation method and application of the efficient environment-friendly adhesive, and relates to the technical field of adhesives. The invention relates to an efficient environment-friendly adhesive, which is prepared from the following components in parts by weight: 10 to 20 parts of flexible polyurethane prepolymer, 15 to 30 parts of bisphenol A epoxy acrylate, 4 to 6 parts of silane coupling agent, 0.3 to 0.5 part of catalyst and 10 to 15 parts of filler, and the composite polyol comprises a CO2-based polycarbonate polyol with the molecular weight of 2000 to 3000. The polyurethane adhesive prepared according to the formula not only has higher curing speed, but also has higher and balanced comprehensive performance. When the adhesive is applied to production and preparation of the automobile air conditioner pipe, not only can the bonding requirement be met, but also the curing time of the adhesive can be shortened, and the production process of the automobile air conditioner pipe can be simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesives, in particular to a high-efficiency environment-friendly adhesive for automobile air conditioner pipes and a preparation method and application thereof. BACKGROUND

[0002] The automobile air conditioner pipe is one of the indispensable components in the modern automobile air conditioner system, which is used to connect the components of the automobile air conditioner system and realize the circulation of the refrigerant. At present, in order to prevent the leakage of the refrigerant in the automobile air conditioner pipe from causing frequent replenishment or damage to the automobile air conditioner system, most manufacturers will add a resin barrier layer inside the automobile air conditioner pipe. The resin barrier layer and the outer rubber sleeve are bonded to each other, so that even if the outer rubber sleeve of the automobile air conditioner pipe is damaged or perforated, the refrigerant inside the automobile air conditioner pipe is not easy to leak out.

[0003] However, the adhesion problem between the resin barrier layer and the rubber sleeve has become a bottleneck restricting the development of the industry in the production and preparation process of the automobile air conditioner pipe. Although there are many adhesives on the market that can effectively meet the bonding requirements between the resin barrier layer and the rubber sleeve, most of the adhesives still have the problems of complex coating process, long curing time, high preparation cost, etc., which have obvious limitations, so that the production process of the automobile air conditioner pipe is long and the production cost is high, especially in large-scale industrial production, it is difficult to produce efficiency and economy. In addition, the adhesives on the market may also have environmental pollution risks, which are difficult to meet the requirements of green and environmentally friendly production process in modern industrial production.

[0004] Therefore, under the background of increasing environmental pressure at the present stage, on the premise of meeting the bonding requirements between the resin barrier layer and the rubber sleeve, it is of great market value significance for the automobile industry to develop an adhesive with simple coating process, high curing efficiency, economy and environmental protection, and to simplify the production process of the automobile air conditioner pipe and reduce the production cost of the automobile air conditioner pipe. SUMMARY

[0005] In order to improve the bonding performance of the adhesive for the automobile air conditioner pipe, meet the bonding requirements of the automobile air conditioner pipe, improve the curing efficiency of the adhesive, and simplify the production process of the automobile air conditioner pipe, the present application provides a high-efficiency environment-friendly adhesive for automobile air conditioner pipes and a preparation method and application thereof.

[0006] In the first aspect, the high-efficiency environment-friendly adhesive provided by the present application adopts the following technical scheme: A high-efficiency environment-friendly adhesive comprises the following raw materials by mass: flexible polyurethane prepolymer: 10-20 parts; bisphenol A epoxy acrylate: 15-30 parts; silane coupling agent: 4-6 parts; Catalyst: 0.1-0.5 parts; Filler: 12-18 parts; The flexible polyurethane prepolymer is prepared by pre-polymerization of a mixture of an excess of aliphatic isocyanate and a composite polyol, wherein the composite polyol comprises a CO2-based polycarbonate polyol, and the CO2-based polycarbonate polyol has a molecular weight of 2000-3000.

[0007] By adopting the above technical solution, the polyurethane adhesive prepared has not only a faster curing speed, but also higher peeling strength and mechanical properties, and has good comprehensive performance and balance. When the polyurethane adhesive prepared by the above scheme is applied to the production of automobile air conditioning pipes, it not only meets the bonding requirements of automobile air conditioning pipes, but also shortens the coating and curing time due to the high curing efficiency, thereby simplifying the production process of automobile air conditioning pipes.

[0008] Optionally, the composite polyol further comprises a low-viscosity vegetable oil-based polyol, and the vegetable oil-based polyol comprises at least one of castor oil-based polyol, cashew nut shell oil-based polyol, or soybean oil-based polyol.

[0009] By adopting the above technical solution, different vegetable oil-based polyols are introduced, which can adjust the different properties of the polyurethane adhesive according to the use scene requirements of the polyurethane adhesive, so that the polyurethane adhesive has high versatility. Moreover, the vegetable oil-based polyol contains long-chain vegetable oil-based segments, which can effectively adjust the dispersion degree of the polyurethane hard segment, and is beneficial to balancing the flexibility and tensile strength of the polyurethane adhesive, and the comprehensive performance is better.

[0010] Optionally, the composite polyol is a mixture of polypropylene carbonate diol, cashew nut shell oil-based polyol, and soybean oil-based polyol, and the hydroxyl molar ratio of the polypropylene carbonate diol, the cashew nut shell oil-based polyol, and the soybean oil-based polyol is 4:(1-1.5):(0.5-1).

[0011] By adopting the above technical solution, a polyurethane adhesive with high comprehensive performance can be prepared, which not only has high curing efficiency, but also maintains high levels of peeling strength and mechanical properties.

[0012] Optionally, a photoinitiator is further included, and the addition amount of the photoinitiator is 3%-5% of the addition amount of the epoxy acrylate resin.

[0013] By adopting the above technical solution, the bisphenol A epoxy acrylate in the system is conducive to further improving the curing speed of the polyurethane adhesive, and thus when the polyurethane adhesive is applied to the production of automobile air conditioning pipes, the curing and bonding time can be effectively shortened, and the production process of the automobile air conditioning pipes can be simplified.

[0014] Optionally, the silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, and the mixing mass ratio of the γ-aminopropyltriethoxysilane to the γ-mercaptopropyltrimethoxysilane is (3-4):1.

[0015] By adopting the above technical solution, it is not only beneficial to improve the curing efficiency of the polyurethane adhesive, but also beneficial to improve the bonding strength of the polyurethane adhesive at the resin-rubber interface, making the polyurethane adhesive suitable for the production and preparation of automobile air-conditioning pipes.

[0016] Optionally, the catalyst is one of stannous octoate or dibutyltin dilaurate.

[0017] By adopting the above technical solution, the flexible polyurethane prepolymer and bisphenol A epoxy acrylate can be effectively promoted to react and cure at room temperature, which is beneficial to improving the curing efficiency of the polyurethane adhesive.

[0018] Optionally, the filler is talc, or a mixture of talc and at least one of nano-silicon dioxide and ultrafine mica powder.

[0019] By adopting the above technical solution, talc powder not only appropriately adjusts the viscosity of the polyurethane adhesive but also enhances its mechanical properties, resulting in excellent bond strength after curing. Furthermore, the addition of at least one of nanomaterials, such as nanosilica or ultrafine mica powder, in combination with talc powder can further enhance the mechanical properties of the polyurethane adhesive while maintaining the same filler dosage. This not only helps control the raw material cost of the polyurethane adhesive but also improves its overall performance.

[0020] Optionally, the filler is a mixture of talc powder and nano-silicon dioxide, and the mixing mass ratio of the talc powder to the nano-silicon dioxide is (3-5):1.

[0021] By adopting the above technical solution, it is beneficial to prepare a polyurethane adhesive with high peel strength and tensile strength.

[0022] In a second aspect, the present application provides a method for preparing a high-efficiency and environmentally friendly adhesive using the following technical solution: A method for preparing an efficient and environmentally friendly adhesive comprises the following steps: S1. Add 10-20 wt% of a flexible polyurethane prepolymer to N,N-dimethylformamide, heat to 80-88° C. and stir thoroughly, then reduce the temperature to below 60° C., add bisphenol A epoxy acrylate and a silane coupling agent, stir and mix thoroughly, cool to obtain component A, and store in the dark; add other additives such as a filler and a catalyst to an appropriate amount of N,N-dimethylformamide, stir and disperse thoroughly at room temperature to obtain component B, and store in the dark; S2. When an adhesive is needed, component A and component B are mixed, stirred thoroughly, and adjusted to a suitable viscosity using an appropriate amount of N,N-dimethylformamide to obtain a highly efficient and environmentally friendly adhesive.

[0023] The above-described technical solution not only simplifies the preparation method but also allows for direct application by simply mixing components A and B. This simplifies the preparation of the polyurethane adhesive before use, thereby optimizing the application process and making it suitable for large-scale industrial production. Furthermore, separating the polyurethane adhesive into components A and B and storing them away from light effectively reduces the risk of curing during storage, thereby extending its shelf life.

[0024] In a third aspect, the application of a high-efficiency and environmentally friendly adhesive provided by this application adopts the following technical solution: The invention discloses an application of a high-efficiency and environmentally friendly adhesive in the production and preparation of automobile air-conditioning pipes.

[0025] By adopting the above technical solution, the bonding performance of the adhesive for automobile air-conditioning pipes can be effectively improved. It not only has a faster curing speed, which is conducive to simplifying the production process of automobile air-conditioning pipes, but also has high bonding peel strength and heat and hydrolysis resistance, which is conducive to preventing the automobile air-conditioning pipes from being fully bonded between the resin isolation layer and the rubber sleeve after long-term use, and not easily falling off and separating.

[0026] In summary, the technical solution of this application has at least one of the following beneficial effects: 1. By using aliphatic isocyanate and CO2-based polycarbonate polyol to synthesize a flexible polyurethane prepolymer, combined with bisphenol A epoxy acrylate and other additives, a polyurethane adhesive with faster curing speed, higher peel strength and mechanical properties can be produced.

[0027] 2. By adding different vegetable oil-based polyols to the system, the different properties of the polyurethane adhesive can be adjusted according to the usage scenarios of the polyurethane adhesive, making the polyurethane adhesive more versatile. It is also beneficial to balance the flexibility and tensile strength of the polyurethane adhesive containing epoxy resin, making its overall performance better.

[0028] 3. By introducing a photoinitiator into the system and combining it with bisphenol A epoxy acrylate, the polyurethane adhesive can be effectively catalyzed to rapidly cure under light conditions, which is beneficial to further improve the curing efficiency of the polyurethane adhesive and can be applied to instant bonding operations on online production lines.

[0029] 4. Reasonable selection of silane coupling agent can help improve the peel strength of polyurethane adhesive for different materials.

[0030] 5. By optimizing the type and proportion of fillers added, the rheological properties of polyurethane adhesives can be effectively improved, which is conducive to the preparation of polyurethane adhesives with excellent comprehensive performance. DETAILED DESCRIPTION

[0031] The present application is further described in detail below with reference to preparation examples, embodiments and comparative examples.

[0032] Polypropylene carbonate diol was purchased from Dazhi Fine Chemicals, with specific grades being PPCD 221 and PPCD 231. PPCD-221 has a molecular weight of 2000 and a viscosity of 1000-2000 mPa.s / 40°C, while PPCD-231 has a molecular weight of 3000 and a viscosity of 4000-6000 mPa.s / 40°C.

[0033] The castor oil-based polyol was purchased from modified castor oil diol of Vantellus, with a specific brand name of D-2000, a molecular weight of 2000, and a viscosity of 1360 cps / 25°C.

[0034] The cashew nut shell liquid-based polyol was purchased from Cardolite's cashew nut shell liquid diol, specifically the brand NX-9201LP, with a viscosity of 1300 cps / 25°C.

[0035] The soybean oil-based polyol was purchased from the vegetable oil-based polyol of Haierma Group, with a specific brand name of HM-13160, a molecular weight of 1000, and a viscosity of 1000 cps / 25°C.

[0036] Bisphenol A epoxy acrylate was purchased from Boxing New Materials, with a specific brand name of B-151, wherein the viscosity of the brand is 12000-20000 cps / 60°C.

[0037] γ-Aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane were purchased from Nanjing Nengde New Materials.

[0038] Preparation Example [Preparation Example 1-1] A flexible polyurethane prepolymer is prepared by the following preparation steps: Take 50wt% of aliphatic isocyanate and dissolve it in N,N-dimethylformamide. Add complex polyol according to the molar ratio of NCO:OH=2:1 and stir thoroughly. Then add stannous octoate, heat to 95℃ and continue stirring for 2h. After the reaction reaches the isocyanate value close to the theoretical value, distill under reduced pressure and dry in vacuum to obtain a flexible polyurethane prepolymer.

[0039] In this preparation example, the aliphatic isocyanate is specifically selected from hexamethylene diisocyanate; the complex polyol is a mixture of polypropylene carbonate diol PPCD-221 and polypropylene carbonate diol PPCD-231, specifically, the hydroxyl molar ratio of polypropylene carbonate diol PPCD-222 and polypropylene carbonate diol PPCD-231 is 1:2; and the amount of stannous octoate added is 0.5% of the amount of the complex polyol added.

[0040] [Preparation Example 1-2] A flexible polyurethane prepolymer is prepared by the following preparation steps: Take 50wt% of aliphatic isocyanate and dissolve it in N,N-dimethylformamide. Add complex polyol according to the molar ratio of NCO:OH=2.3:1 and stir thoroughly. Then add stannous octoate, heat to 110℃ and continue stirring for 1.5h. After the reaction reaches the isocyanate value close to the theoretical value, reduce pressure distillation and vacuum drying to obtain a flexible polyurethane prepolymer.

[0041] In this preparation example, the aliphatic isocyanate is specifically selected from hexamethylene diisocyanate; the complex polyol is a mixture of polypropylene carbonate diol PPCD-221, polypropylene carbonate diol PPCD-231, and castor oil-based polyol. Specifically, the hydroxyl molar ratio of polypropylene carbonate diol PPCD-221, polypropylene carbonate diol PPCD-231, and castor oil-based polyol is 1:4:1; and the added amount of stannous octoate is 0.5% of the added mass of the complex polyol.

[0042] [Preparation Examples 1-3] A flexible polyurethane prepolymer is prepared by the following preparation steps: Take 50wt% of aliphatic isocyanate and dissolve it in N,N-dimethylformamide. Add complex polyol according to the molar ratio of NCO:OH=1.6:1 and stir thoroughly. Then add stannous octoate, heat to 110℃ and continue stirring for 1.5h. After the reaction reaches the isocyanate value close to the theoretical value, distill under reduced pressure and dry in vacuum to obtain a flexible polyurethane prepolymer.

[0043] In this preparation example, the aliphatic isocyanate is specifically selected from hexamethylene diisocyanate; the complex polyol is a mixture of polypropylene carbonate diol PPCD-231, castor oil-based polyol, and cashew nut shell oil-based polyol. Specifically, the molar ratio of hydroxyl groups of polypropylene carbonate diol PPCD-231, castor oil-based polyol, and cashew nut shell oil-based polyol is 3:1:1; and the amount of stannous octoate added is 0.5% of the added mass of the complex polyol.

[0044] [Preparation Examples 1-4] A flexible polyurethane prepolymer differs from [Preparation Example 1-1] in that the compound polyol is different.

[0045] In this preparation example, the composite polyol is a mixture of polypropylene carbonate diol PPCD-231 and castor oil-based polyol. Specifically, the molar ratio of the hydroxyl groups of polypropylene carbonate diol PPCD-231 and castor oil-based polyol is 2:1.

[0046] [Preparation Examples 1-5] A flexible polyurethane prepolymer differs from [Preparation Example 1-1] in that the compound polyol is different.

[0047] In this preparation example, the composite polyol is a mixture of polypropylene carbonate diol PPCD-231 and cashew nut shell oil-based polyol. Specifically, the molar ratio of the hydroxyl groups of polypropylene carbonate diol PPCD-231 and cashew nut shell oil-based polyol is 2:1.

[0048] [Preparation Example 1-6] A flexible polyurethane prepolymer differs from [Preparation Example 1-1] in that the compound polyol is different.

[0049] In this preparation example, the composite polyol is a mixture of polypropylene carbonate diol PPCD-231 and soybean oil-based polyol. Specifically, the molar ratio of the hydroxyl groups of polypropylene carbonate diol PPCD-231 and soybean oil-based polyol is 2:1.

[0050] [Preparation Example 1-7] A flexible polyurethane prepolymer differs from [Preparation Example 1-1] in that the compound polyol is different.

[0051] In this preparation example, the composite polyol is a mixture of polypropylene carbonate diol PPCD-231, cashew nut shell oil-based polyol and soybean oil-based polyol. Specifically, the molar ratio of the hydroxyl groups of polypropylene carbonate diol PPCD-231 and soybean oil-based polyol is 4:1:1.

[0052] [Preparation Example 1-8] A polyurethane prepolymer differs from [Preparation Example 1-1] in that the compound polyol is different.

[0053] In this preparation example, PPG-3000 was used to replace the complex polyol in equal amounts. Example

[0054] [Example 1] A high-efficiency and environmentally friendly adhesive comprises the following raw materials: 15 kg of flexible polyurethane prepolymer, 20 kg of bisphenol A epoxy acrylate, 5 kg of silane coupling agent, 0.3 kg of catalyst, and 12 kg of filler.

[0055] In this embodiment, the flexible polyurethane prepolymer is a flexible polyurethane prepolymer prepared in [Preparation Example 1]; the silane coupling agent is γ-aminopropyltriethoxysilane; the catalyst is dibutyltin dilaurate; and the filler is talc.

[0056] A method for preparing an efficient and environmentally friendly adhesive comprises the following steps: S1. Add 15 wt% of a flexible polyurethane prepolymer to N,N-dimethylformamide, heat to 85° C. and stir thoroughly for 5 minutes, then reduce the temperature to 60° C., add bisphenol A epoxy acrylate and a silane coupling agent, stir and mix thoroughly for 30 minutes, cool to obtain component A, and store in the dark; add 50 wt% of a filler to N,N-dimethylformamide, add a catalyst, stir and disperse thoroughly at room temperature for 30 minutes, to obtain component B, and store in the dark; S2. When an adhesive is needed, mix component A and component B, stir and mix thoroughly for 10 minutes, and use an appropriate amount of N,N-dimethylformamide to adjust the viscosity to a suitable value to obtain a highly efficient and environmentally friendly adhesive.

[0057] [Example 2] A high-efficiency and environmentally friendly adhesive comprises the following raw materials: 10 parts of flexible polyurethane prepolymer, 30 kg of bisphenol A epoxy acrylate, 6 kg of silane coupling agent, 0.5 kg of catalyst, and 10 kg of filler.

[0058] In this embodiment, the flexible polyurethane prepolymer is a flexible polyurethane prepolymer prepared in [Preparation Example 1]; the silane coupling agent is γ-aminopropyltriethoxysilane; the catalyst is dibutyltin dilaurate; and the filler is a mixture of talc and nano-silica, specifically including 7.5 kg of talc and 2.5 kg of nano-silica.

[0059] A method for preparing an efficient and environmentally friendly adhesive comprises the following steps: S1. Add 10 wt% of a flexible polyurethane prepolymer to N,N-dimethylformamide, heat to 80° C. and stir thoroughly for 5 minutes, then reduce the temperature to 60° C., add bisphenol A epoxy acrylate and a silane coupling agent, stir and mix thoroughly for 30 minutes, cool to obtain component A, and store in the dark; add 50 wt% of a filler to N,N-dimethylformamide, add a catalyst, stir and disperse thoroughly at room temperature for 30 minutes to obtain component B, and store in the dark; S2. When an adhesive is needed, mix component A and component B, stir and mix thoroughly for 10 minutes, and use an appropriate amount of N,N-dimethylformamide to adjust the viscosity to a suitable value to obtain a highly efficient and environmentally friendly adhesive.

[0060] [Example 3] A high-efficiency and environmentally friendly adhesive comprises the following raw materials: 20 kg of flexible polyurethane prepolymer, 15 kg of bisphenol A epoxy acrylate, 4 kg of silane coupling agent, 0.5 kg of catalyst, and 15 kg of filler.

[0061] In this embodiment, the flexible polyurethane prepolymer is a flexible polyurethane prepolymer prepared in [Preparation Example 1]; the silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, specifically including 3 kg of γ-aminopropyltriethoxysilane and 1 kg of γ-mercaptopropyltrimethoxysilane; the catalyst is dibutyltin dilaurate; and the filler is nano-silica and ultrafine mica powder, specifically including 10 kg of talc powder, 2.5 kg of nano-silica and 2.5 kg of ultrafine mica powder.

[0062] A method for preparing an efficient and environmentally friendly adhesive comprises the following steps: S1. Add 20 wt% of a flexible polyurethane prepolymer to N,N-dimethylformamide, heat to 88° C. and stir thoroughly for 5 minutes, then reduce the temperature to 60° C., add bisphenol A epoxy acrylate and a silane coupling agent, stir and mix thoroughly for 30 minutes, cool to obtain component A, and store in the dark; add 50 wt% of a filler to N,N-dimethylformamide, add a catalyst, stir and disperse thoroughly at room temperature for 30 minutes, to obtain component B, and store in the dark; S2. When an adhesive is needed, mix component A and component B, stir and mix thoroughly for 10 minutes, and use an appropriate amount of N,N-dimethylformamide to adjust the viscosity to a suitable value to obtain a highly efficient and environmentally friendly adhesive.

[0063] [Example 4] A high-efficiency and environmentally friendly adhesive, which differs from [Example 1] in that the flexible polyurethane prepolymer is different.

[0064] In this embodiment, the flexible polyurethane prepolymer is specifically selected from a flexible polyurethane prepolymer prepared in [Preparation Example 4].

[0065] [Example 5] A high-efficiency and environmentally friendly adhesive, which differs from [Example 1] in that the flexible polyurethane prepolymer is different.

[0066] In this embodiment, the flexible polyurethane prepolymer is specifically selected from a flexible polyurethane prepolymer prepared in [Preparation Example 5].

[0067] [Example 6] A high-efficiency and environmentally friendly adhesive, which differs from [Example 1] in that the flexible polyurethane prepolymer is different.

[0068] In this embodiment, the flexible polyurethane prepolymer is specifically selected from a flexible polyurethane prepolymer prepared in [Preparation Example 6].

[0069] [Example 7] A high-efficiency and environmentally friendly adhesive, which differs from [Example 1] in that the flexible polyurethane prepolymer is different.

[0070] In this embodiment, the flexible polyurethane prepolymer is specifically selected from a flexible polyurethane prepolymer prepared in [Preparation Example 7].

[0071] [Example 8] A high-efficiency and environmentally friendly adhesive, which differs from [Example 7] in that it also includes a photoinitiator.

[0072] In this embodiment, the photoinitiator is specifically selected as photoinitiator TPO, and the added amount of photoinitiator TPO is 5% of the added amount of bisphenol A epoxy acrylate, that is, 1 kg.

[0073] A method for preparing an efficient and environmentally friendly adhesive, which differs from [Preparation Example 7] in step S1.

[0074] In this embodiment, when preparing component B in step S1, the photoinitiator and the catalyst need to be added together.

[0075] [Example 9] A high-efficiency and environmentally friendly adhesive, which differs from [Example 8] in the silane coupling agent used.

[0076] In this embodiment, the silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, specifically comprising 4 kg of γ-aminopropyltriethoxysilane and 1 kg of γ-mercaptopropyltrimethoxysilane.

[0077] [Example 10] A high-efficiency and environmentally friendly adhesive, which differs from [Example 9] in that the filler is different.

[0078] In this embodiment, the fillers are talc powder and nano-silicon dioxide, specifically including 10 kg of talc powder and 2 kg of nano-silicon dioxide.

[0079] [Example 11] A high-efficiency and environmentally friendly adhesive, which differs from [Example 9] in that the filler is different.

[0080] In this embodiment, the fillers are talc powder and nano-silicon dioxide, specifically including 10 kg of talc powder and 2 kg of ultrafine mica powder.

[0081] Comparative Example [Comparative Example 1] An adhesive, which differs from [Example 1] in that no flexible polyurethane prepolymer is used.

[0082] In this comparative example, an equal amount of a polyurethane prepolymer prepared in [Preparation Example 8] was used to replace the flexible polyurethane prepolymer.

[0083] [Comparative Example 2] An adhesive, which differs from [Example 1] in that bisphenol A epoxy acrylate is not added.

[0084] In this comparative example, the flexible polyurethane prepolymer prepared in [Preparation Example 1] was used in place of bisphenol A epoxy acrylate, and 5 kg of 1,4-butanediol was also added. Specifically, in this comparative example, an adhesive comprised the following raw materials: 35 kg of flexible polyurethane prepolymer, 5 kg of 1,4-butanediol, 5 kg of silane coupling agent, 0.3 kg of catalyst, and 12 kg of filler.

[0085] [Comparative Example 3] An adhesive, which differs from [Example 1] in that bisphenol A epoxy acrylate is not added.

[0086] In this comparative example, bisphenol A epoxy resin (E51 type) was used to replace bisphenol A epoxy acrylate in equal amounts.

[0087] Performance test data 1. Curing Speed ​​Test: The test was conducted according to Section 6.8 of HG / T 4363-2012, One-Component Polyurethane Adhesives for Automotive Window Glass. The test lasted 24 hours under natural light. The curing speed (mm / 24 hours) of the adhesives prepared in the Examples and Comparative Examples was recorded.

[0088] 2. Flexibility test: The test was conducted in accordance with GB / T 13477.7-2002 Test methods for building sealing materials - Part 7: Determination of low-temperature flexibility, and the cracking of the adhesives prepared in the examples and comparative examples was recorded.

[0089] 3. Bond Strength Test: A material identical to the resin barrier layer and rubber sleeve of an automotive air conditioning duct was used as the bonding member. The adhesive prepared in each Example and Comparative Example was applied between the two. The adhesive was allowed to stand at room temperature for 48 hours to fully cure, thereby producing a bond specimen. The bond specimen was then tested in accordance with GB / T 2791-1995, Adhesives - T-Peel Strength Test Method - Flexible Material to Flexible Material. The peel strength (N / 25mm) of the polyurethane adhesive prepared in each Example and Comparative Example after curing was recorded.

[0090] 4. Bond durability: Place the bonded specimens under conditions of 85°C and 95% relative humidity for 240 hours. Remove them and dry the surface moisture. Place them under standard conditions at room temperature for 4 hours, and then test their peel strength (N / 25mm) again.

[0091] 5. Tensile Strength Test: The test was conducted according to ASTM D412 Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension, and the tensile strength (MPa) of the adhesives prepared in each Example and Comparative Example was recorded.

[0092] Table 1 Partial performance test data of adhesives Combining Example 1 and Comparative Examples 1-3 with the data in Table 1, it can be seen that in Example 1, by synthesizing a flexible polyurethane prepolymer using aliphatic isocyanate and CO2-based polycarbonate polyol, and combining it with bisphenol A epoxy acrylate and other additives, the polyurethane adhesive prepared not only has a faster curing speed, but also has higher peel strength and mechanical properties. The comprehensive performance is not only high but also relatively balanced, which can fully meet the bonding requirements of automotive air-conditioning pipes.

[0093] Among them, from the comparison of Example 1 and Comparative Example 1 and their performance data, it can be seen that by using CO2-based polycarbonate polyol to synthesize a flexible polyurethane prepolymer, specifically polypropylene carbonate diol with a molecular weight of 3000, compared with using polypropylene glycol with the same molecular weight to synthesize a flexible polyurethane prepolymer, although the curing speed of the prepared polyurethane adhesive is slightly reduced, the flexibility and peel strength of the adhesive after curing are significantly improved. This may be because the carbonate group in the molecular chain of polypropylene carbonate polyol increases the molecular chain rigidity of the flexible polyurethane prepolymer, thereby affecting the reaction rate. However, because of this, the polyurethane adhesive can have a longer operating time, can be fully cured and has good and balanced comprehensive performance. In addition, it can be seen from Example 1 and Comparative Examples 2-3 and their data that bisphenol A epoxy acrylate can not only significantly improve the peel strength and mechanical strength of the polyurethane adhesive, but also, compared with the traditional bisphenol A epoxy resin, it can further improve the curing speed and flexibility of the polyurethane adhesive. This may be because bisphenol A epoxy acrylate further introduces acrylate segments, which not only enables the polyurethane adhesive to undergo free radical polymerization, improves its curing efficiency, and reduces the influence of epoxy resin on the curing speed of the polyurethane adhesive, but also the flexible acrylate segments can cooperate with the interpenetrating network structure formed by the epoxy groups, so that after the polyurethane adhesive is cured, it has both a rigid epoxy phase and an elastic acrylate phase inside, which is beneficial to disperse stress and inhibit crack propagation, thereby improving its flexibility.

[0094] Combining Examples 1 and 4-7 with the data in Table 1, it can be seen that while the introduction of different plant oil-based polyols can moderately improve some of the properties of the polyurethane adhesive, it can also produce some adverse effects. However, when a flexible polyurethane prepolymer is synthesized by reacting an aliphatic isocyanate with a polypropylene carbonate diol, a cashew nut shell oil-based polyol, and a soybean oil-based polyol, the resulting polyurethane adhesive not only exhibits a relatively fast cure speed but also exhibits high flexibility, peel strength, and tensile strength, resulting in good and balanced overall performance. This may be because the plant oil-based polyol contains plant oil-based segments with different branching chains. During synthesis, the dispersion of the soft and hard segments of the polyurethane varies, affecting the overall crystallinity and, in turn, resulting in different properties of the polyurethane adhesive.

[0095] Combining Examples 7-8 with the data in Table 1, it can be seen that by further introducing a photoinitiator into the system and coordinating the bisphenol A epoxy acrylate in the system, the curing speed of the polyurethane adhesive can be further improved.

[0096] Combining Examples 8-9 with the data in Table 1, it can be seen that when the silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, the resulting polyurethane adhesive not only has a faster curing speed, but also has a higher peel strength for the resin isolation layer-rubber sleeve bonding medium of the automotive air conditioning pipe.

[0097] Combining Examples 9-11 and the data in Table 1, it can be seen that when the filler is talc and nano-silica mixed in a specific proportion, the peel strength and tensile strength of the polyurethane adhesive are significantly improved compared to when only talc is added. In addition, when ultrafine mica powder is used to replace nano-silica in equal amounts, although the peel strength and tensile strength of the polyurethane adhesive will decrease, the peel strength of the polyurethane adhesive decreases less under long-term high heat and high humidity environment, which means that the polyurethane adhesive has better heat and hydrolysis resistance at this time.

[0098] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high-efficiency and environmentally friendly adhesive, characterized in that: Comprising the following raw materials in parts by mass: Flexible polyurethane prepolymer: 10-20 parts; Bisphenol A epoxy acrylate: 15-30 parts; Silane coupling agent: 4-6 parts; Catalyst: 0.3-0.5 parts; Filler: 10-15 parts; The flexible polyurethane prepolymer is prepared by mixing an excess of aliphatic isocyanate and a complex polyol and then performing a prepolymerization reaction. The complex polyol includes a CO2-based polycarbonate polyol, and the molecular weight of the CO2-based polycarbonate polyol is 2000-3000.

2. The high-efficiency and environmentally friendly adhesive according to claim 1, characterized in that The complex polyol also includes a low-viscosity vegetable oil-based polyol, and the vegetable oil-based polyol includes at least one of castor oil-based polyol, cashew nut shell oil-based polyol or soybean oil-based polyol.

3. The high-efficiency and environmentally friendly adhesive according to claim 2, characterized in that : The composite polyol is specifically a mixture of polypropylene carbonate diol, cashew nut shell oil-based polyol and soybean oil-based polyol, and the hydroxyl molar ratio of the polypropylene carbonate diol, the cashew nut shell oil-based polyol and the soybean oil-based polyol is 4:(1-1.5):(0.5-1).

4. The high-efficiency and environmentally friendly adhesive according to claim 1, characterized in that : Also includes a photoinitiator, the amount of the photoinitiator added is 3%-5% of the amount of the epoxy acrylate resin added.

5. The high-efficiency and environmentally friendly adhesive according to claim 1, characterized in that : The silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane, and the mixing mass ratio of the γ-aminopropyltriethoxysilane and the γ-mercaptopropyltrimethoxysilane is (3-4):

1.

6. The high-efficiency and environmentally friendly adhesive according to claim 1, characterized in that : The catalyst is one of stannous octoate or dibutyltin dilaurate.

7. The high-efficiency and environmentally friendly adhesive according to claim 1, characterized in that The filler is talcum powder, or a mixture of at least one of nano silicon dioxide and ultrafine mica powder and talcum powder.

8. The high-efficiency and environmentally friendly adhesive according to claim 7, characterized in that : The filler is a mixture of talc powder and nano-silicon dioxide, and the mixing mass ratio of the talc powder to the nano-silicon dioxide is (3-5):

1.

9. A method for preparing a high-efficiency environmentally friendly adhesive, for preparing a high-efficiency environmentally friendly adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Add 10-20 wt% of a flexible polyurethane prepolymer to N,N-dimethylformamide, heat to 80-88° C. and stir thoroughly, then reduce the temperature to below 60° C., add bisphenol A epoxy acrylate and a silane coupling agent, stir and mix thoroughly, cool to obtain component A, and store in the dark; add other additives such as a filler and a catalyst to an appropriate amount of N,N-dimethylformamide, stir and disperse thoroughly at room temperature to obtain component B, and store in the dark; S2. When an adhesive is needed, component A and component B are mixed, stirred thoroughly, and adjusted to a suitable viscosity using an appropriate amount of N,N-dimethylformamide to obtain a highly efficient and environmentally friendly adhesive.

10. An application of a high-efficiency and environmentally friendly adhesive, applicable to a high-efficiency and environmentally friendly adhesive according to any one of claims 1 to 8, characterized in that : Used in the production and preparation of automobile air-conditioning pipes.

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