A two-component super-low-temperature-resistant polyurethane adhesive as well as a preparation method and application thereof

Abstract

The application relates to the technical field of polyurethane adhesives, and particularly discloses a two-component super-low-temperature-resistant polyurethane adhesive as well as a preparation method and application thereof. The two-component super-low-temperature-resistant polyurethane adhesive comprises an A component and a B component which are independently packaged; the A component comprises polyhydric alcohol, a filler, a catalyst, a thixotropic agent and a defoaming agent; the polyhydric alcohol comprises bisphenol A modified polyhydric alcohol, bio-based polyhydric alcohol and / or polyether polyhydric alcohol; the bisphenol A modified polyhydric alcohol has a hydroxyl value of 250-320 mgKOH / g, a functionality of 2.0 and a viscosity of 3000-20000 mPa.s. The two-component super-low-temperature-resistant polyurethane adhesive has high bonding strength, shear strength and good adhesion due to the compounding of the bisphenol A modified polyether with a benzene ring structure and the bio-based polyhydric alcohol and the polyether polyhydric alcohol, so that the adhesive can be used for a long time at minus 196 DEG C, and the mechanical properties remain unchanged.

Description

Technical Field

[0001] This application relates to the field of polyurethane adhesive technology, and more specifically, to a two-component ultra-low temperature resistant polyurethane adhesive, its preparation method, and its application. Background Technology

[0002] In international and intercontinental long-distance transportation, ships are commonly used to transport cryogenic liquefied gases such as natural gas, liquefied ethane, and liquefied propane stored in tanks. In tanks storing cryogenic liquids such as liquefied natural gas, adhesives are typically used to bond the insulation materials between the tank bodies and between the insulation materials and the tank body materials.

[0003] In storage tanks for cryogenic liquefied gases such as liquefied natural gas, adhesives are typically used at temperatures as low as -196°C. However, ordinary adhesives are prone to cracking and embrittlement in ultra-low temperature environments.

[0004] Therefore, there is an urgent need to develop an adhesive for ultra-low temperature environments that can be used stably at -196℃. Summary of the Invention

[0005] To improve the low-temperature stability of adhesives, this application provides a two-component ultra-low temperature resistant polyurethane adhesive, its preparation method, and its application.

[0006] In a first aspect, this application provides a two-component ultra-low temperature resistant polyurethane adhesive, employing the following technical solution: A two-component ultra-low temperature resistant polyurethane adhesive, comprising separately packaged component A and component B; Component A comprises the following components in parts by weight: 20-60 parts of polyols; 20-55 parts of filler; Catalyst 0.01 to 1 part; Thixotropic agent 0.1–5 parts; 0-2 parts of defoamer; 1-10 parts of absorbent; The polyols include bisphenol A modified polyols, bio-based polyols, and / or polyether polyols; The weight ratio of the bisphenol A modified polyol to the bio-based polyol is 1:(1-3); The molecular structural formula of the bisphenol A modified polyol is: , where n is 1 to 5; The bisphenol A modified polyol has a hydroxyl value of 250–320 mgKOH / g, a functionality of 2.0, and a viscosity of 3000–20000 mPa·s. Component B includes polyphenyl polymethylene polyisocyanate.

[0007] By adopting the above technical solution, on the one hand, because bisphenol A-modified polyols and polyphenyl polymethylene polyisocyanates contain benzene ring structures, they possess rigidity. Therefore, using polyphenyl polymethylene polyisocyanates and bisphenol A-modified polyols as the hard segment phase region, the urethane bonds and urea bonds formed by the reaction with other polyols will aggregate with the benzene ring through strong hydrogen bonds and van der Waals forces, which can effectively improve the strength and heat resistance of the adhesive.

[0008] On the other hand, bio-based polyols contain long-chain fatty acids and inherent ester bonds, while polyether polyols contain ether bonds, both exhibiting excellent flexibility, low-temperature flexibility, hydrolysis resistance, and toughness. Therefore, using bio-based polyols and / or polyether polyols as the soft segment phase region ensures that the adhesive does not vitrify at ultra-low temperatures and still maintains excellent flexibility, elasticity, and low-temperature flexibility.

[0009] Therefore, by using specific raw materials to formulate the adhesive, this application enables the adhesive to have an excellent microphase separation structure. When used at a temperature of -196°C, the adhesive changes from a highly elastic state to a leather-like state or a hard, highly elastic state, without becoming brittle like glass. Furthermore, the adhesive can disperse and bear stress, allowing it to maintain sufficient strength even at ultra-low temperatures.

[0010] Preferably, the bio-based polyol is one or two of castor oil-based or natural oil-modified polyols.

[0011] Preferably, the castor oil-based modified polyol has a hydroxyl value of 163 mg KOH / g and a viscosity of 680 mPa·s.

[0012] Preferably, the hydroxyl value of the natural oil-modified polyol is 160-330 mg KOH / g, and the viscosity is 700-4000 mPa·s.

[0013] Preferably, the hydroxyl value of the polyether polyol is 30–100 mgKOH / g.

[0014] By adopting the above technical solution, the polyol with the above properties is compounded and then reacted with polyphenyl polymethylene polyisocyanate to form an adhesive that has excellent strength, elasticity and low-temperature flexibility, making it tough, strong and durable even in an extremely cold environment of -196℃.

[0015] Preferably, the filler is one or more of calcium carbonate, kaolin, and titanium dioxide.

[0016] Preferably, the catalyst is one or more of triethylenediamine, dibutyltin dilaurate, and organobismuth.

[0017] Preferably, the thixotropic agent is one or two of gaseous silica and organobentonite.

[0018] Preferably, the polyphenyl polymethylene polyisocyanate has a viscosity of 150–700 mPa·s, an NCO content of 30–32%, and a functionality of 2.6–3.0.

[0019] Preferably, the mass ratio of component A to component B is (3-5):1.

[0020] Secondly, this application provides a method for preparing a two-component ultra-low temperature resistant polyurethane adhesive, using the following technical solution: A method for preparing a two-component ultra-low temperature resistant polyurethane adhesive includes the following steps: S1: First, mix the polyol, catalyst, thixotropic agent and defoamer, then dehydrate under vacuum at 100-120℃ and 0.05-0.1MPa for 2-4 hours, and then cool down to below 50℃ to obtain a dehydrated polyol mixture; S2: Dry the filler at 120-150℃ for 2-4 hours to obtain dehydrated filler; add the dehydrated filler to the dehydrated polyol mixture, stir and mix at 20-50℃ and 800-1500r / min for 0.5-2 hours, finally add the desiccant, stir and mix for 10-20 minutes to obtain component A; S3: Mix component A and component B to obtain a two-component ultra-low temperature resistant polyurethane adhesive.

[0021] By adopting the above technical solution, the polyol, catalyst, thixotropic agent and defoamer are first dehydrated by vacuuming and the filler is dried, which can reduce the moisture content. This not only improves the storage stability of the obtained component A, but also reduces the reaction between water and polyphenyl polymethylene polyisocyanate, improves the generation of bubbles in the adhesive, and is conducive to the formation of a dense adhesive layer.

[0022] Thirdly, this application provides an application of a two-component ultra-low temperature resistant polyurethane adhesive, employing the following technical solution: An application of a two-component cryogenic polyurethane adhesive in bonding insulation panels for LNG, LEG, and liquid nitrogen cryogenic liquefied gas ship storage tanks, as well as in bonding longitudinal and transverse seams of insulation layers in pipelines.

[0023] By adopting the above technical solution, the two-component ultra-low temperature resistant polyurethane adhesive of this application has the advantages of high strength, strong adhesion, no cracking, and long-term use in low temperature environments. It can be used in the bonding of insulation panels for LNG, LEG, and liquid nitrogen cryogenic liquefied gas ship storage tanks, as well as in the bonding of longitudinal and transverse seams of insulation layers in pipelines, and can also play a certain protective role for insulation materials.

[0024] In summary, this application has the following beneficial effects: 1. Because this application uses bisphenol A modified polyol, bio-based polyol and / or polyether polyol compound, the adhesive is endowed with high bonding strength, shear strength and good adhesion. In particular, the benzene ring structure of bisphenol A modified polyether and the urethane structure after the adhesive is cured together give the adhesive stable mechanical properties, which can be used for a long time at -196℃ without changing mechanical properties, and has excellent low temperature resistance. 2. In this application, the curing rate can be flexibly adjusted by adding catalyst, and the flow state can be adjusted by thixotropic agent to adapt to different construction and production environments, so that it can be used for machine application and manual application, thereby improving the applicability of adhesive; 3. Bio-based polyols have excellent environmental friendliness. In this application, bio-based raw materials are compounded with bisphenol A modified polyols, which effectively reduces the long-term environmental impact of adhesives. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] Unless otherwise specified below, all raw materials used in the embodiments of this application are commercially available. Bisphenol A modified polyol, brand name NTS-11s, with a hydroxyl value of 300-320 mgKOH / g, was purchased from Suzhou Netes Polyurethane Co., Ltd. Castor oil, with a hydroxyl value of 163 mg KOH / g and a viscosity of 680 mPa·s, was purchased from Guangzhou Maoting Chemical Co., Ltd. The bio-based polyol, brand name Sovermol 750, with a hydroxyl value of 300-330 mgKOH / g and a viscosity of 700-1400 mPa·s, was purchased from BASF (China) Co., Ltd. The polyether polyol, Lupronol Balance 50, with a hydroxyl value of 50 mg KOH / g, was purchased from BASF (China) Co., Ltd. Heavy calcium carbonate, purchased from Omia (China) Co., Ltd. Fumed silica, brand name AEROSIL 200, was purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd. Triethylenediamine was purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd. Dibutyltin was purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd. Fumed silica, brand name AEROSIL 200, was purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd. Liquid molecular sieve, 100 / 3A, was purchased from Ningrui Adhesives. Defoamer, brand name ACP-1000, purchased from Dow Chemical (Shanghai) Co., Ltd. Polyphenyl polymethylene polyisocyanate, brand name M20S, was purchased from BASF Polyurethanes Chongqing (Co., Ltd.) Example Example 1

[0027] A two-component ultra-low temperature resistant polyurethane adhesive includes separately packaged component A and component B; the mass ratio of components A and B is 4:1 when used.

[0028] The following table shows the weight (kg) of component A and its corresponding raw materials.

[0029]

[0030] Component B is polyphenyl polymethylene polyisocyanate, purchased from BASF Polyurethanes Chongqing (Co., Ltd.), brand name M20S.

[0031] The preparation method of the above-mentioned two-component ultra-low temperature resistant polyurethane adhesive includes the following steps: S1: First, mix the polyol, catalyst, thixotropic agent and defoamer, then dehydrate under vacuum at 115℃ and 0.1MPa for 2 hours, and then cool down to below 50℃ to obtain a dehydrated polyol mixture.

[0032] S2: Dry the filler at 120℃ for 2 hours to obtain the dehydrated filler; add the dehydrated filler to the dehydrated polyol mixture, stir and mix at 35±5℃ and 900r / min for 1 hour, and finally add the desiccant and stir and mix for 10 minutes to obtain component A.

[0033] S3: Mix component A and component B to obtain a two-component ultra-low temperature resistant polyurethane adhesive.

[0034] Examples 2-3 A two-component ultra-low temperature resistant polyurethane adhesive differs from Example 1 in that the weight (kg) of component A and its corresponding raw material is shown in the table below.

[0035] Comparative Example

[0036] Comparative Examples 1-2 A two-component polyurethane adhesive differs from Example 1 in that the weight (kg) of component A and its corresponding raw material is shown in the table below.

[0037] The two-component ultra-low temperature resistant polyurethane adhesive prepared in the embodiments of this application and the two-component polyurethane adhesive prepared in the comparative example were subjected to open time, surface drying time, hardness, shear strength, high and low temperature thermal cycling tests, and shear strength after high and low temperature cycling tests. The test methods are as follows:

[0038] Opening time: Tested according to GB7123-86 Determination of pot life of adhesives; Surface drying time: Tested according to GB1728-79 Method B: touch method; Hardness: Tested according to ISO 7619-1; Shear strength, high and low temperature thermal cycling test and shear strength after high and low temperature cycling: tested according to GB / T 7124-2008, the bonding substrate is aluminum alloy; The performance test results are shown in the table below.

[0039]

[0040] Data analysis of the table above shows that the shear strength of Example 2 is significantly improved compared to Example 1. This indicates that the use of bisphenol A-modified polyol NTS-11s, castor oil, and bio-based polyol Lupronol Balance 50 in the total raw materials for preparing the two-component ultra-low temperature resistant polyurethane adhesive of this application can improve the shear strength of the two-component ultra-low temperature resistant polyurethane adhesive.

[0041] Compared to Example 2, the shear strength of Example 3 showed little change. This indicates that in the total raw materials for preparing the two-component ultra-low temperature resistant polyurethane adhesive of this application, the bio-based polyols castor oil or Sovermol 750 can both improve the shear strength of the two-component ultra-low temperature resistant polyurethane adhesive.

[0042] Compared to Example 1, the shear strength of Comparative Examples 1 and 2 was significantly reduced, and slight cracks appeared in the -196℃ high and low temperature thermal cycling test. This indicates that in the total raw materials for preparing the two-component ultra-low temperature resistant polyurethane adhesive of this application, the bisphenol A modified polyol NTS-11s and castor oil have a synergistic effect, which can improve the shear strength and low temperature resistance of the two-component ultra-low temperature resistant polyurethane adhesive.

[0043] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A two-component ultra-low temperature resistant polyurethane adhesive, characterized in that, Includes individually packaged components A and B; Component A comprises the following components in parts by weight: 20-60 parts of polyols; 20-55 parts of filler; Catalyst 0.01 to 1 part; Thixotropic agent 0.1–5 parts; 0-2 parts of defoamer; 1-10 parts of absorbent; The polyols include bisphenol A modified polyols, bio-based polyols, and / or polyether polyols; The weight ratio of the bisphenol A modified polyol to the bio-based polyol is 1:(1-3); The molecular structural formula of the bisphenol A modified polyol is: , where n is 1 to 5; Component B includes polyphenyl polymethylene polyisocyanate.

2. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 1, characterized in that, The bisphenol A modified polyol has a hydroxyl value of 250–320 mgKOH / g, a functionality of 2.0, and a viscosity of 3000–20000 mPa•s.

3. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 1, characterized in that, The bio-based polyol is one or two of castor oil-based or natural oil-modified polyols.

4. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 3, characterized in that, The castor oil-based modified polyol has a hydroxyl value of 163 mg KOH / g and a viscosity of 680 mPa·s.

5. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 3, characterized in that, The hydroxyl value of the natural oil-modified polyol is 160–330 mg KOH / g, and the viscosity is 700–4000 mPa·s.

6. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 1, characterized in that, The hydroxyl value of the polyether polyol is 30–100 mgKOH / g.

7. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 1, characterized in that, The polyphenyl polymethylene polyisocyanate has a viscosity of 150–700 mPa·s, an NCO content of 30–32%, and a functionality of 2.6–3.

0.

8. The two-component ultra-low temperature resistant polyurethane adhesive according to claim 1, characterized in that, The mass ratio of component A to component B is (3-5):

1.

9. A method for preparing the two-component ultra-low temperature resistant polyurethane adhesive according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: First, mix the polyol, catalyst, thixotropic agent and defoamer, then dehydrate under vacuum at 100-120℃ and 0.05-0.1MPa for 2-4 hours, and then cool down to below 50℃ to obtain a dehydrated polyol mixture; S2: Dry the filler at 120-150℃ for 2-4 hours to obtain dehydrated filler; add the dehydrated filler to the dehydrated polyol mixture, stir and mix at 20-50℃ and 800-1500r / min for 0.5-2 hours, finally add the desiccant, stir and mix for 10-20 minutes to obtain component A; S3: Mix component A and component B to obtain a two-component ultra-low temperature resistant polyurethane adhesive.

10. The application of the two-component cryogenic polyurethane adhesive according to any one of claims 1 to 8 in the bonding of insulation panels for LNG, LEG, and liquid nitrogen cryogenic liquefied gas ship storage tanks, and in the bonding of longitudinal and transverse seams of insulation layers for pipelines.

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