Winter jelly-resistant gel for bonding aluminum cellular board and preparation method thereof

Abstract

The invention relates to the technical field of polyurethane adhesives, in particular to winter jelly-resistant gel for bonding aluminum cellular boards and a preparation method of the winter jelly-resistant gel. The main agent is at least prepared from the following raw materials in parts by weight: 30 to 50 parts of vegetable oil, 5 to 8 parts of trifunctional hydroxyl-terminated polypropylene oxide ether, 2 to 5 parts of bisphenol A polyether polyol, 0.7 to 1 part of dihydric alcohol, 30 to 40 parts of filler, 2 to 6.2 parts of molecular sieve, 0.5 to 0.8 part of silane coupling agent, 0.25 to 1 part of catalyst, 1 to 5 parts of plasticizer, 0.4 to 0.8 part of wetting dispersant and 0.1 to 0.5 part of fumed silica; by comprehensively regulating and controlling the selection and addition amount of the raw materials in the system, the provided product has excellent low-temperature resistance when being used for bonding the aluminum honeycomb plate, the phenomena of cracking, bulging or embrittlement and the like of the honeycomb plate in the construction process are avoided, and the actual application requirements are met.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane adhesives, and specifically to a winter freeze-resistant adhesive for bonding aluminum honeycomb panels and a preparation method thereof. Background Art

[0002] In a winter low-temperature environment (<5°C), during the construction process of honeycomb panels, phenomena such as chipping, bulging, or embrittlement occur. After uncovering, basically all the glue is taken away by the honeycomb core, resulting in no glue adhering to the aluminum plate surface, and the strength and effect both fail to meet the actual application requirements. Chinese Patent (authorized announcement number: CN119432302B) discloses an adhesive for tooling smooth aluminum and a preparation method thereof, mainly by optimizing the formula of the adhesive to achieve efficient bonding of smooth aluminum and honeycomb panels, but it cannot overcome the problem of insufficient glue strength in a low-temperature environment. Chinese Patent Application (publication number: CN119505783A) discloses a fast-curing two-component hot-pressing adhesive and a preparation method and application thereof. By adjusting the particle size and type of fillers and cooperating with the optimization of catalysts and curing agents, a fast-curing two-component hot-pressing adhesive is obtained, but the pot life of the product is short, increasing the construction difficulty. Summary of the Invention

[0003] To solve the above problems, the present invention provides a winter freeze-resistant adhesive for bonding aluminum honeycomb panels. By comprehensively controlling the selection and addition amount of each raw material in the system, the provided product has excellent low-temperature resistance when used for bonding aluminum honeycomb panels, avoiding phenomena such as chipping, bulging, or embrittlement during the construction process of honeycomb panels and meeting the actual application requirements.

[0004] On the one hand, the present invention provides a winter freeze-resistant adhesive for bonding aluminum honeycomb panels, including a main agent and a curing agent; calculated by weight, the preparation raw materials of the main agent at least include: 30 - 50 parts of vegetable oil, 5 - 8 parts of trifunctional hydroxyl-terminated polypropylene oxide ether, 2 - 5 parts of bisphenol A polyether polyol, 0.7 - 1 part of diol, 30 - 40 parts of filler, 2 - 6.2 parts of molecular sieve, 0.5 - 0.8 part of silane coupling agent, 0.25 - 1 part of catalyst, 1 - 5 parts of plasticizer, 0.4 - 0.8 part of wetting and dispersing agent, and 0.1 - 0.5 part of fumed silica.

[0005] In one embodiment, the vegetable oil is at least one of castor oil, soybean oil, or cashew shell oil.

[0006] In one embodiment, the hydroxyl value of the trifunctional hydroxyl-terminated polypropylene oxide ether is 350 - 450 mgKOH / g.

[0007] In one embodiment, the hydroxyl value of the trifunctional hydroxyl-terminated polypropylene oxide ether is 374 - 390 mgKOH / g, the product grade is T-403, and it is sourced from Greenlink (Jining) Chemical Technology Co., Ltd.

[0008] In one embodiment, the hydroxyl value of the bisphenol A polyether polyol is 200 - 300 mgKOH / g.

[0009] In one embodiment, the hydroxyl value of the bisphenol A polyether polyol is 220 - 230 mgKOH / g, the product grade is BPA-3, and it is sourced from Shandong Shangzheng New Materials Technology Co., Ltd.

[0010] In one embodiment, the diol is selected from at least one of propylene glycol, ethylene glycol, or butylene glycol.

[0011] In one embodiment, the molecular sieve at least includes 3A molecular sieve.

[0012] In one embodiment, the catalyst is an amine catalyst, and the mass ratio of the amine catalyst to the diol is (0.28 - 0.5) : (0.7 - 1).

[0013] In one embodiment, the amine catalyst is selected from triethylenediamine or pentamethyldiethylenetriamine.

[0014] In one embodiment, the plasticizer is fatty acid methyl ester, and the mass ratio of the fatty acid methyl ester to the 3A molecular sieve is (4 - 6) : (1.5 - 3).

[0015] In one embodiment, the wetting and dispersing agent is an alkyl ammonium salt solution of polycarboxylic acid.

[0016] In one embodiment, the model of the wetting agent and dispersing agent is BYK-202.

[0017] In one embodiment, the silane coupling agent is isocyanatopropyltriethoxysilane.

[0018] In one embodiment, by weight, the raw materials for preparing the main agent include: 38 - 42 parts of vegetable oil, 6.5 - 7 parts of trifunctional hydroxyl-terminated polypropylene oxide ether, 2.5 - 3.3 parts of bisphenol A polyether polyol, 0.7 - 1 part of diol, 34 - 36 parts of filler, 4.8 - 6 parts of molecular sieve, 0.5 - 0.8 part of silane coupling agent, 0.3 - 0.35 part of catalyst, 1.8 - 2 parts of plasticizer, 0.5 - 0.6 part of wetting and dispersing agent, and 0.2 - 0.3 part of fumed silica.

[0019] The present invention mainly optimizes the problems existing in the actual production application process after the existing polyurethane adhesive is applied to the bonding of the aluminum plate-honeycomb core-aluminum plate sandwich structure. However, during the development of the product, there is a situation where the film hardness, active period, curing time, and low-temperature bonding performance of the adhesive film cannot be effectively balanced. Through a large number of experimental explorations, it is found that by simultaneously introducing trifunctional hydroxyl-terminated polypropylene oxide ether, bisphenol A polyether polyol, diol, molecular sieve, wetting and dispersing agent, catalyst, plasticizer, and silane coupling agent, and controlling the addition amounts of each raw material, when the provided polyurethane adhesive is used for the low-temperature (<5°C) lamination of the honeycomb core and the aluminum plate, the obtained aluminum honeycomb panel has good material breakage effect, and the adhesive film adhesion area on the aluminum plate surface is ≥90%, meeting the actual construction requirements and being particularly suitable for the low-temperature environment in winter. However, there are still some products with a relatively short activation period or relatively low film hardness. The inventor analyzes the reasons as follows: Through the cooperation of the above raw materials and the control of the addition amounts, on the one hand, it can overcome the problems of slow curing rate, incomplete curing, loose structure, brittleness, and low mechanical strength under low-temperature environments; on the other hand, the plasticizer, molecular sieve, and coupling agent in the system can overcome the problem of too high glass transition temperature, frozen molecular chains, hard and brittle adhesive layer, and inability to release stress through deformation under low-temperature environments when added in appropriate amounts; on the third hand, through the combined action of trifunctional hydroxyl-terminated polypropylene oxide ether, bisphenol A polyether polyol, diol, silane coupling agent, and wetting agent, the mechanical strength of the colloid is improved, and the problem of decreased surface energy of the aluminum plate, poor wettability of the glue, and inability to fully penetrate the micropores of the substrate, resulting in a decrease in bonding strength under low temperature is overcome.

[0020] Furthermore, in the present invention, the molecular sieve in the system is optimized to be 3A molecular sieve, and the catalyst is an amine catalyst. By controlling the mass ratio of the amine catalyst to the diol to be (0.28 - 0.5):(0.7 - 1), while ensuring that the obtained aluminum honeycomb panel has excellent material breakage effect at low temperature, the active period of the product is controlled within 4 - 8 minutes, meeting the requirements of actual production applications. Further, by controlling the plasticizer in the system to be fatty acid methyl ester and controlling the mass ratio of the fatty acid methyl ester to the 3A molecular sieve to be (4 - 6):(1.5 - 3), while ensuring that the film hardness of the product is within the range of 93 - 95, the curing time of the product is shortened to improve production efficiency, and the low-temperature lamination effect of the adhesive for the honeycomb core and the aluminum plate can be further improved.

[0021] In one embodiment, the filler at least includes a calcium-based filler, and the particle size of the calcium-based filler is 800 - 1000 mesh.

[0022] In one embodiment, the calcium-based filler is calcium carbonate, and the product brand is 1250-mesh heavy calcium, sourced from Helixin.

[0023] In one embodiment, the BET specific surface area of the fumed silica is 150 - 250 m² / g.

[0024] In one embodiment, the fumed silica is of the type AEROSIL 200 and is sourced from Shandong Wanhua Tianhe New Materials.

[0025] In one embodiment, the curing agent is an isocyanate curing agent with an isocyanate group content (-NCO) of 20 - 40 wt%.

[0026] In one embodiment, the -NCO content of the isocyanate curing agent is 30.5 - 32.0 wt%.

[0027] In one embodiment, the isocyanate curing agent is polymeric MDI, and the model of the polymeric MDI is Wanhua PM200.

[0028] In one embodiment, the mass ratio of the main agent to the curing agent is (4 - 6):1.

[0029] In one embodiment, the mass ratio of the main agent to the curing agent is 5:1.

[0030] On the other hand, the present invention provides a method for preparing a winter freeze-resistant adhesive for bonding aluminum honeycomb panels, which at least includes the following steps: by weight, mix the raw materials of the main agent to obtain the main agent; when in use, mix the main agent and the curing agent and then use.

[0031] In one embodiment, the method for preparing the main agent includes the following steps: place vegetable oil, trifunctional hydroxyl-terminated polypropylene oxide ether, bisphenol A polyether polyol, and diol in a container, stir at 500 - 1000 r / min for 10 - 30 min to obtain a glue solution; stop stirring, add fumed silica, control the rotation speed at 100 - 300 r / min and stir for 3 - 5 min, adjust the rotation speed to 500 - 900 r / min and stir for 5 - 15 min to obtain mixture 1; adjust the rotation speed to 1000 - 1200 r / min, add inorganic filler and molecular sieve to mixture 1 and stir for 20 - 30 min to obtain mixture 2; add a wetting and dispersing agent to mixture 2 and stir at 1000 - 1200 r / min for 0.5 - 1.5 h to obtain mixture 3; add a catalyst, a plasticizer, and a coupling agent to mixture 3 and stir at 1000 - 1200 r / min for 20 - 30 min, and then evacuate and stir at 1000 - 1200 r / min for 20 - 40 min to obtain the main agent.

[0032] The method for preparing the freeze-resistant adhesive provided by the present invention is simple, easy to control, and easy to realize large-scale industrial production and application.

[0033] Beneficial effects 1. The present invention provides a winter antifreeze adhesive for bonding aluminum honeycomb panels. By selecting and controlling the addition amount of each raw material in a comprehensive regulation system, the provided product has excellent low temperature resistance when used for bonding aluminum honeycomb panels, avoiding the occurrence of collapse, bulging or brittleness of the honeycomb panels during the construction process, and meeting the actual application needs.

[0034] 2. The present invention simultaneously introduces trifunctional terminal hydroxyl polypropylene oxide ether, bisphenol A polyether polyol, diol, molecular sieve, wetting dispersant, catalyst, plasticizer and silane coupling agent, and controls the addition amount of each raw material, so that the provided polyurethane adhesive is used for low-temperature (<5°C) composite of honeycomb core and aluminum plate, and the obtained aluminum honeycomb panel has good material breaking effect, and the adhesive film adhesion area on the aluminum plate surface is ≥90%, which meets the actual construction requirements and is particularly suitable for low-temperature environment in winter.

[0035] 3. The present invention optimizes the system so that the molecular sieve is 3A molecular sieve, the catalyst is an amine catalyst, and the mass ratio of the amine catalyst to the diol is controlled to be (0.28-0.5): (0.7-1). While ensuring that the obtained aluminum honeycomb panel has excellent material breaking effect at low temperature, the activity period of the product is controlled to 4-8 minutes, meeting the actual production application needs.

[0036] 4. By controlling the plasticizer in the system to be fatty acid methyl ester and controlling the mass ratio of fatty acid methyl ester and 3A molecular sieve to be (4-6): (1.5-3), the hardness of the product film is ensured to be within the range of 93-95, while shortening the curing time of the product and improving production efficiency, and further improving the low-temperature composite effect of the adhesive for honeycomb core and aluminum plate.

[0037] 5. The preparation method of the freeze-resistant glue provided by the present invention is simple, easy to control, and easy to realize large-scale industrial production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a diagram showing the material breaking effect of Example 1.

[0039] Figure 2 This is the material breaking effect diagram of Example 2.

[0040] Figure 3 This is a diagram showing the material breaking effect of Example 3.

[0041] Figure 4 This is the material breaking effect diagram of comparative example 1.

[0042] Figure 5 This is the material breaking effect diagram of comparative example 2.

[0043] Figure 6 This is the material breaking effect diagram of comparative example 3.

[0044] Figure 7Effect diagram of material breakage for Comparative Example 4

[0045] Figure 8 Effect diagram of material breakage for Comparative Example 5

[0046] Figure 9 Effect diagram of material breakage for Comparative Example 6

[0047] Figure 10 Effect diagram of material breakage for Comparative Example 7

[0048] Figure 11 Effect diagram of material breakage for Comparative Example 8

[0049] Figure 12 Effect diagram of material breakage for Comparative Example 9

[0050] Figure 13 Effect diagram of material breakage for Comparative Example 10

[0051] Figure 14 Effect diagram of material breakage for Comparative Example 11

[0052] Figure 15 Effect diagram of material breakage for Comparative Example 12

[0053] Figure 16 Effect diagram of material breakage for Comparative Example 13 Detailed implementation mode

[0054] Examples 1 - 3, Comparative Examples 1 - 13 Examples 1 - 3 and Comparative Examples 1 - 13 of the present invention provide a winter freeze - resistant adhesive for bonding aluminum honeycomb panels, which is composed of a main agent and a curing agent in a mass ratio of 5:1; by weight, the raw materials for preparing the main agent are shown in Table 1 and Table 2, and the curing agent is polymeric MDI (Wanhua PM200).

[0055] Table 1

[0056] In Table 1, the hydroxyl value of the trifunctional terminal - hydroxyl polypropylene oxide ether is 374 - 390 mgKOH / g, and the hydroxyl value of the bisphenol A polyether polyol is 220 - 230 mgKOH / g.

[0057] Table 2

[0058] In Table 2, the hydroxyl value of the trifunctional terminal - hydroxyl polypropylene oxide ether is 374 - 390 mgKOH / g, and the hydroxyl value of the bisphenol A polyether polyol is 220 - 230 mgKOH / g.

[0059] Examples 1-3 of the present invention and Comparative Examples 1-13 on the other hand provide a method for preparing a winter freeze-resistant adhesive for bonding aluminum honeycomb panels, comprising the following steps: placing vegetable oil, trifunctional hydroxyl-terminated polypropylene oxide ether, bisphenol A polyether polyol, and diol in a container, stirring at 800 r / min for 20 min to obtain a glue solution; stopping stirring, adding fumed silica, controlling the rotation speed at 200 r / min and stirring for 5 min, adjusting the rotation speed to 800 r / min and stirring for 10 min to obtain mixture 1; adjusting the rotation speed to 1200 r / min, adding inorganic filler and molecular sieve to mixture 1 and stirring for 20 min to obtain mixture 2; adding a wetting and dispersing agent to mixture 2 and stirring at 1200 r / min for 1 h to obtain mixture 3; adding a catalyst, a plasticizer, and a coupling agent to mixture 3 and stirring at 1200 r / min for 20 min, evacuating and stirring at 1200 r / min for 30 min to obtain the main agent; when in use, mixing the main agent and the curing agent and then using them.

[0060] Performance Test 1. Glue film hardness: After uniformly mixing the main agent and the curing agent in each example (mixing time is 20 s), coating on the surface of the aluminum plate, and curing (curing conditions are 22 ± 1 °C, 24 h) to obtain a glue film with a thickness of 6 mm, using a Shore hardness tester to test the hardness of the glue film (a hardness range of 93 - 95 is more appropriate), and the test results are shown in Table 3.

[0061] 2. Pot life: After uniformly mixing the main agent and the curing agent in each example (mixing time is 20 s), when obvious resistance appears during stirring, it is determined that the pot life ends (generally controlled at 4 - 8 min in the process is more appropriate), and the results are shown in Table 3.

[0062] 3. Material breakage effect at low temperature: After uniformly mixing the main agent and the curing agent in each example (mixing time is 20 s), coating (coating amount is 250 g / m 2 ) on the aluminum plate, compounding with the honeycomb core, using a press to press to the limit, relieving pressure after pressing at -5 °C for 10 hours, curing for 24 h, and then conducting a hand tearing and peeling test on the aluminum plate and the honeycomb core (controlling the same peeling force in each example and comparative example during the experiment), the material breakage effect is shown in Figure 1-16 , calculating the area ratio of the glue film attached to the aluminum plate after peeling, and the results are shown in Table 3.

[0063] 4. Curing time: After uniformly mixing the main agent and the curing agent in each example (mixing time is 20 s), coating (coating amount is 250 g / m 2 ) on the aluminum plate, when the glue film cannot be damaged, it is determined as initial curing (generally controlled at 10 - 12 h in the process, the shorter the better), and the results are shown in Table 3.

[0064] Table 3

[0065] It can be seen from the data in Table 3 that the antifreeze adhesives provided in Examples 1-3 effectively balance the hardness, active life, curing time and low-temperature bonding performance of the product compared with the antifreeze adhesives provided in Comparative Examples 1-13, and better meet the actual application requirements.

Claims

1. A winter freeze-resistant adhesive for bonding aluminum honeycomb panels, characterized in that, It includes a main agent and a curing agent; By weight, the raw materials for preparing the main agent at least include: 30-50 parts of vegetable oil, 5-8 parts of trifunctional hydroxyl-terminated polypropylene oxide ether, 2-5 parts of bisphenol A polyether polyol, 0.7-1 part of diol, 30-40 parts of filler, 2-6.2 parts of molecular sieve, 0.5-0.8 part of silane coupling agent, 0.25-1 part of catalyst, 1-5 parts of plasticizer, 0.4-0.8 part of wetting and dispersing agent, 0.1-0.5 part of fumed silica; the hydroxyl value of the trifunctional hydroxyl-terminated polypropylene oxide ether is 350-450 mgKOH / g, and the hydroxyl value of the bisphenol A polyether polyol is 200-300 mgKOH / g.

2. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 1, wherein, The diol is selected from at least one of propylene glycol, ethylene glycol or butanediol.

3. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 2, characterized in that, The catalyst is an amine catalyst, and the mass ratio of the amine catalyst to the diol is (0.28-0.5):(0.7-1).

4. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 2, characterized in that, The molecular sieve at least includes 3A molecular sieve.

5. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 4, wherein, The plasticizer is fatty acid methyl ester, and the mass ratio of the fatty acid methyl ester to the 3A molecular sieve is (4-6):(1.5-3).

6. The winter frost-resistant adhesive for bonding aluminum honeycomb panels according to claim 1, characterized in that, The wetting and dispersing agent is an alkyl ammonium salt solution of polycarboxylic acid.

7. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 1, characterized in that, The filler at least includes a calcareous filler, and the particle size of the calcareous filler is 800-1000 mesh.

8. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 1, characterized in that, The mass ratio of the main agent to the curing agent is (4-6):

1.

9. The winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to claim 8, characterized in that, The curing agent is an isocyanate curing agent with an isocyanate group content of 20-40wt%.

10. A preparation method of a winter freeze-resistant adhesive for bonding aluminum honeycomb panels according to any one of claims 1-9, characterized in that, By weight, the raw materials of the main agent are mixed to obtain the main agent; during use, the main agent and the curing agent are blended and then used.

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