Two-component polyurethane adhesive

Abstract

The present application provides a two-component polyurethane adhesive, comprising a first component and a second component, wherein the first component comprises a first resin, a second resin, a first filler, a water scavenger, an anti-settling agent, and a catalyst, and the second component comprises a prepolymer, an isocyanate, a second filler, a flame retardant, and an anti-settling agent. The prepolymer is selected from reaction products of a polyol and a diisocyanate. The polyol is selected from at least one of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone diol, polycarbonate diol, castor oil, and modified castor oil. The diisocyanate is selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate. The isocyanate is selected from a hexamethylene diisocyanate trimer. By means of such configuration, the two-component polyurethane adhesive not only has a relatively long work life, but can also be quickly cured in a short time at room temperature to produce a relatively high initial curing strength, thereby improving production efficiency and reducing energy consumption.

Description

A two-component polyurethane adhesive

[0001] This application claims priority to Chinese Patent Application No. 202510055345.5, filed on January 14, 2025, entitled "A Two-Component Polyurethane Adhesive", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of adhesive technology, and in particular to a two-component polyurethane adhesive. Background Technology

[0003] With the rapid development of China's new energy vehicle industry, the demand for lithium-ion battery packs, a core component of new energy vehicles, has also increased dramatically. Compared to traditional welding methods, the emerging method of assembling lithium-ion battery packs using adhesives offers advantages such as safety, lightweight design, and customizable functionality. Two-component polyurethane structural adhesives account for more than 30% of the global polyurethane adhesive market. Compared to epoxy and acrylic adhesives, two-component polyurethane adhesives have advantages such as being virtually odorless, having a mild and controllable reaction, relatively low rigidity, strong vibration resistance, and high functional adjustability.

[0004] The working time of two-component polyurethane adhesives is generally controlled by the amount of catalyst used. Reducing the amount of catalyst can extend the working time, but it also prolongs the time required to achieve high initial solid strength. Generally, when the working time of a two-component polyurethane adhesive after mixing is controlled to be approximately 30 minutes, the initial solid strength achieved at room temperature after 40 minutes is almost zero. Therefore, a longer working time is needed to obtain higher initial solid strength, resulting in lower production efficiency. To achieve high initial solid strength within a short period after the working time, such as approximately 10 minutes, additional energy input, such as heating, is often required to shorten the time to achieve initial solid strength. Although increasing the amount of catalyst may also achieve high initial solid strength at room temperature within approximately 40 minutes, this would shorten the working time to approximately 5 minutes, which is too short and would prevent complete application. Therefore, there is an urgent need to develop a two-component polyurethane adhesive that has both a longer working time and can rapidly cure at room temperature to achieve high initial solid strength in a short time, in order to improve production efficiency and reduce energy consumption. Summary of the Invention

[0005] The purpose of this application is to provide a two-component polyurethane adhesive to solve the problems of short working time and long time to achieve high initial strength at room temperature in two-component polyurethane adhesives, thereby improving production efficiency and reducing energy consumption. The specific technical solution is as follows:

[0006] This application provides a two-component polyurethane adhesive, comprising a first component and a second component. The first component comprises 15wt%–40wt% of a first resin, 15wt%–40wt% of a second resin, 20wt%–50wt% of a first filler, 2wt%–8wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst. The second component comprises 10wt%–40wt% of a prepolymer, 10wt%–40wt% of an isocyanate, 20wt%–40wt% of a second filler, 3wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent. Preferably, the first component comprises 20wt%–40wt% of a first resin, 18wt%–40wt% of a second resin, 30wt%–40wt% of a first filler, 2wt%–5wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst; the second component comprises 12wt%–40wt% of a prepolymer, 12wt%–40wt% of an isocyanate, 20wt%–30wt% of a second filler, 5wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent. The first resin is selected from at least one of modified castor oil, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, and polycarbonate diol; the second resin is selected from at least one of bisphenol A polyoxypropylene ether, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, and polycarbonate diol; the first resin and the second resin are selected from different substances. The prepolymer is selected from the reaction product of polyol and diisocyanate, wherein the polyol is selected from at least one of polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, polycarbonate diol, castor oil and modified castor oil, and the diisocyanate is selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate; the isocyanate is selected from hexamethylene diisocyanate trimer.

[0007] In some embodiments of this application, the modified castor oil is modified by at least one selected from polyethylene glycol, polyether diol, small molecule polyol and soybean oil, and the modified castor oil has an average functionality of 2.5 to 3.

[0008] In some embodiments of this application, the number average molecular weight of the modified castor oil is 1000 to 2000.

[0009] In some embodiments of this application, the catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, triethylamine chelate, diethylenetriamine, and triethylenediamine.

[0010] In some embodiments of this application, the first filler is selected from at least one of aluminum hydroxide, calcium carbonate, bentonite and silica, the dehydrating agent is selected from at least one of molecular sieve, p-toluenesulfonyl isocyanate, triethyl orthoformate and 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine, and the anti-settling agent is selected from at least one of fumed silica and paraffin.

[0011] In some embodiments of this application, the prepolymer is selected from the reaction product of polypropylene glycol, modified castor oil, and isophorone diisocyanate; based on the mass of the prepolymer, the mass percentage of polypropylene glycol is 30% to 70%; the mass percentage of modified castor oil is 5% to 30%; and the mass percentage of isophorone diisocyanate is 20% to 60%.

[0012] In some embodiments of this application, the flame retardant is selected from at least one of antimony trioxide, magnesium hydroxide, aluminum hydroxide, antimony oxide, and red phosphorus.

[0013] In some embodiments of this application, the second filler is selected from at least one of alumina, calcium carbonate, bentonite, and silica.

[0014] In some embodiments of this application, the first component further includes a first pigment, the first pigment having a mass percentage content of 0.1 wt% to 2 wt% based on the mass of the first component; the second component further includes a second pigment, the second pigment having a mass percentage content of 0.1 wt% to 1 wt% based on the mass of the second component.

[0015] The beneficial effects of this application are:

[0016] This application provides a two-component polyurethane adhesive, comprising a first component and a second component. The first component includes a first resin, a second resin, a first filler, a dehydrating agent, an anti-settling agent, and a catalyst. The second component includes a prepolymer, an isocyanate, a second filler, a flame retardant, and an anti-settling agent. The prepolymer is selected from a reaction product of a polyol and a diisocyanate. The polyol is selected from at least one of polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, polycarbonate diol, castor oil, and modified castor oil. The diisocyanate is selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate. The isocyanate is selected from hexamethylene diisocyanate trimer. With the above configuration, the two-component polyurethane adhesive can have both a longer working time and rapid curing at room temperature for a short time to produce high initial strength, thereby improving production efficiency and reducing energy consumption.

[0017] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Detailed Implementation

[0018] The technical solutions of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0019] This application provides a two-component polyurethane adhesive, comprising a first component and a second component. The first component comprises 15wt%–40wt% of a first resin, 15wt%–40wt% of a second resin, 20wt%–50wt% of a first filler, 2wt%–8wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst. The second component comprises 10wt%–40wt% of a prepolymer, 10wt%–40wt% of an isocyanate, 20wt%–40wt% of a second filler, 3wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent. Preferably, the first component comprises 20wt%–40wt% of a first resin, 18wt%–40wt% of a second resin, 30wt%–40wt% of a first filler, 2wt%–5wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst; the second component comprises 12wt%–40wt% of a prepolymer, 12wt%–40wt% of an isocyanate, 20wt%–30wt% of a second filler, 5wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent. The first resin is selected from at least one of modified castor oil, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, and polycarbonate diol; the second resin is selected from at least one of bisphenol A polyoxypropylene ether, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, and polycarbonate diol; the first resin and the second resin are selected from different substances; the prepolymer is selected from the reaction product of polyol and diisocyanate, the polyol is selected from at least one of polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, polycarbonate diol, castor oil, and modified castor oil, the diisocyanate is selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate; the isocyanate is selected from hexamethylene diisocyanate trimer.

[0020] The inventors have discovered that by selecting the two-component polyurethane adhesive of this application, the first component includes a first resin and a second resin within the scope of this application, and the second component contains a prepolymer selected from a reaction product of a polyol and a diisocyanate, a diisocyanate selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate, and an isocyanate selected from hexamethylene diisocyanate trimer, and formulated according to the proportions of this application, the first and second components work synergistically, which is beneficial for extending the working time and for rapid curing at room temperature in a short time to produce higher initial strength, thereby improving production efficiency and reducing energy consumption.

[0021] In this application, the mass percentage of the first resin in the first component can be 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, or a range consisting of any two of these values; the mass percentage of the second resin in the first component can be 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, or a range consisting of any two of these values; the mass percentage of the first filler in the first component can be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, or a range consisting of any two of these values; the first component... The mass percentage of the dehydrating agent in the first component can be 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, or any two of these values; the mass percentage of the anti-settling agent in the first component can be 0.5wt%, 0.8wt%, 1wt%, 1.3wt%, 1.5wt%, 1.8wt%, 2wt%, or any two of these values; the mass percentage of the catalyst in the first component can be 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.3wt%, 1.5wt%, 1.8wt%, 2wt%, or any two of these values. For example, the mass percentage of the prepolymer in the second component can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or a range of any two of these values; the mass percentage of the isocyanate in the second component can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or a range of any two of these values; the mass percentage of the second filler in the second component can be 20 wt%, 25 wt%, 30 wt%. The mass percentage of the flame retardant in the second component can be 3wt%, 5wt%, 8wt%, 10wt%, 13wt%, 15wt%, 18wt%, 20wt%, or any two of these values; the mass percentage of the anti-settling agent in the second component can be 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.3wt%, 1.5wt%, 1.8wt%, 2wt%, or any two of these values.

[0022] In some embodiments of this application, the modified castor oil is modified by at least one selected from polyethylene glycol, polyether diol, small molecule polyol, and soybean oil. The average functionality of the modified castor oil is 2.5 to 3. For example, the average functionality of the modified castor oil can be 2.5, 2.6, 2.7, 2.8, 2.9, 3, or a range of any two values ​​therein. The small molecule polyol can be selected from at least one selected from triethylene glycol, 1,4-butanediol, glycerol, and 1,6-hexanediol. By using modified castor oil within the scope of this application, it is beneficial to further improve the initial and final strength of the two-component polyurethane adhesive. This application does not particularly limit the source of the modified castor oil; for example, it can be obtained by purchase or by preparation.

[0023] This application does not impose any particular limitation on the preparation method of modified castor oil, as long as it achieves the purpose of this application. For example, the preparation method of modified castor oil may include, but is not limited to, the following steps: adding castor oil to a reaction vessel equipped with a stirrer, thermometer, and condenser, then slowly adding a small molecule polyol and a catalyst, wherein the catalyst may be selected from acidic catalysts (e.g., p-toluenesulfonic acid) or basic catalysts (e.g., potassium hydroxide, sodium hydroxide, etc.), and stirring to mix evenly. Then, the temperature is raised to 120°C to 200°C, and the reaction is carried out for 3 to 8 hours to allow the hydroxyl groups in the castor oil to undergo esterification and other chemical reactions with the hydroxyl groups of the small molecule polyol. Then, the temperature is lowered to a certain degree, and the catalyst is removed by a suitable method, such as neutralizing with acid (for basic catalysts) or alkali (for acidic catalysts) and then filtering. Afterwards, some water-soluble impurities generated in the reaction are washed away by water, and unreacted small molecule polyols and other low-boiling-point impurities are removed by means of vacuum distillation, etc., finally obtaining modified castor oil.

[0024] In some embodiments of this application, the number-average molecular weight of the modified castor oil is 1000 to 2000. For example, the number-average molecular weight of the modified castor oil can be 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, or any two of these values. By selecting modified castor oil within the range of this application, it is beneficial to further improve the initial and final strength of the two-component polyurethane adhesive.

[0025] In some embodiments of this application, the catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, triethylamine chelated tin, diethylenetriamine, and triethylenediamine. By selecting a catalyst within the scope of this application and controlling the mass percentage of the catalyst within the scope of this application, it is beneficial to promote the curing reaction of the first component and the second component, and to have a suitable operating time.

[0026] In some embodiments of this application, the first filler is selected from at least one of aluminum hydroxide, calcium carbonate, bentonite and silica, the dehydrating agent is selected from at least one of molecular sieve, p-toluenesulfonyl isocyanate, triethyl orthoformate and 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine, and the anti-settling agent is selected from at least one of fumed silica and paraffin.

[0027] In some embodiments of this application, the prepolymer is selected from the reaction product of polypropylene glycol, modified castor oil, and isophorone diisocyanate; based on the mass of the prepolymer, the mass percentage of polypropylene glycol is 30% to 70%; the mass percentage of modified castor oil is 5% to 30%; and the mass percentage of isophorone diisocyanate is 20% to 60%. For example, the mass percentage of polypropylene glycol can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any two of these values; the mass percentage of modified castor oil can be 5%, 8%, 10%, 13%, 15%, 18%, 20%, 30%, or any two of these values; and the mass percentage of isophorone diisocyanate can be 20%, 30%, 40%, 50%, 60%, or any two of these values. The prepolymer is selected from the reactants of polypropylene glycol, modified castor oil and isophorone diisocyanate, and the ratio between the three is controlled within the range of this application, which is beneficial to extend the working time and improve the initial and final strength.

[0028] In some embodiments of this application, the flame retardant is selected from at least one of antimony trioxide, magnesium hydroxide, aluminum hydroxide, antimony oxide, and red phosphorus.

[0029] In some embodiments of this application, the second filler is selected from at least one of alumina, calcium carbonate, bentonite, and silica.

[0030] In some embodiments of this application, the first component further includes a first pigment, the mass percentage of which is 0.1 wt% to 2 wt% based on the mass of the first component; for example, the mass percentage of the first pigment can be 0.1 wt%, 0.4 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, or a range of any two of these values. The second component further includes a second pigment, the mass percentage of which is 0.1 wt% to 1 wt% based on the mass of the second component; for example, the mass percentage of the second pigment can be 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, or a range of any two of these values. This application does not particularly limit the types of the first and second pigments, as long as they achieve the purpose of this application; for example, the first pigment can be selected from yellow pigments, and the second pigment can be selected from blue pigments.

[0031] The two-component polyurethane adhesive of this application is used by mixing the first component and the second component in a volume ratio of 1:1.

[0032] In this application, there are no particular limitations on the source of the raw materials used in the first and second components, as long as they can achieve the purpose of this application. They can be obtained commercially or prepared.

[0033] This application does not particularly limit the preparation methods of the first and second components, as long as they achieve the purpose of this application. For example, the preparation method of the first component can be as follows: add the first resin and the second resin to a vacuum stirrer, heat to 80°C to 120°C, stir for 0.5 h to 2 h, then turn off the heating function, add the first filler, dehydrating agent, and anti-settling agent, and continue vacuum stirring. After the temperature drops below 50°C, add the catalyst and stir evenly to obtain the first component. The preparation method of the second component can be as follows: first, add the polyol and diisocyanate to a reaction vessel under a nitrogen atmosphere in a certain proportion, and react at 80°C to 120°C for 22 h to 26 h to obtain the prepolymer. Then, add the prepolymer and isocyanate to a vacuum stirrer and stir evenly, then add other components and continue stirring to obtain the second component.

[0034] Example

[0035] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Unless otherwise specified, "parts" and "%" refer to mass. All raw materials used in the embodiments and comparative examples of this application are commercially available.

[0036] Test methods and equipment:

[0037] Operation time test

[0038] Place 10ml of the first component and 10ml of the second component into a beaker, so that the 20ml of gel is about 1cm thick in the beaker. Stir for 1 minute and let stand at 25℃. The time when the gel does not string when touched is the working time.

[0039] Testing of initial and final strength

[0040] At 25℃, the first and second components were mixed uniformly at a volume ratio of 1:1. The shear strength after standing at 25℃ for 40 minutes was recorded as the initial solids strength. The shear strength after standing at 25℃ for 7 days was recorded as the final solids strength. The shear strength test method was in accordance with GB / T 7124-2008, and the substrate was aluminum / aluminum (3003 aluminum alloy).

[0041] Example 1

[0042] Preparation of the first component: First resin modified castor oil (castor oil modified with polyethylene glycol 400 (PEG400), the average functionality of the modified castor oil is 2.8, and the number average molecular weight is 1800) and second resin bisphenol A polyoxypropylene ether are added to a vacuum stirrer in proportion, heated to 120℃, and stirred under vacuum for 2 hours. Then the heating function is turned off, and first filler aluminum hydroxide, dehydrating agent molecular sieve, anti-settling agent fumed silica and yellow pigment are added. Vacuum stirring is continued for 1 hour. After the temperature drops below 50℃, catalyst dibutyltin dilaurate is added and stirred for 1 hour to obtain the first component.

[0043] Preparation of the second component: Polypropylene glycol (PPG1000), modified castor oil (castor oil modified with polyethylene glycol 400 (PEG400), the modified castor oil having an average functionality of 2.8 and a number-average molecular weight of 1800), and isophorone diisocyanate were added to a reactor under a nitrogen atmosphere and stirred at 80°C for 24 hours to obtain a prepolymer. Based on the mass of the prepolymer, the mass percentages of polypropylene glycol, modified castor oil, and isophorone diisocyanate were 50%, 30%, and 20%, respectively. Then, the prepolymer and hexamethylene diisocyanate trimer were added to a vacuum stirrer and stirred for 1 hour. Afterward, alumina (the second filler), antimony trioxide (the flame retardant), fumed silica (the anti-settling agent), and blue pigment were added and stirred for 1 hour to obtain the second component. The table above shows the mass percentage of each material in the first and second components.

[0044] Example 2

[0045] Except for adjusting the mass ratio of each material according to the table above, and changing polypropylene glycol 1000 in the second component to polypropylene glycol 2000 (PPG2000), the rest is the same as in Example 1.

[0046] Example 3

[0047] Except for replacing the modified castor oil in the second component prepolymer with polyethylene glycol 300 (PEG300) as shown in the table above, the rest is the same as in Example 1.

[0048] Example 4

[0049] Except for adjusting the mass ratio of each material according to the table above, and replacing isophorone diisocyanate in the second component with dicyclohexylmethane diisocyanate, everything else is the same as in Example 1.

[0050] Example 5

[0051] Except that all the polyols in the prepolymer reactants of the second component are selected from polypropylene glycol 1000 (PPG1000) according to the table above, i.e., the mass percentage of polypropylene glycol 1000 is 80% based on the mass of the prepolymer, and the mass percentage of isophorone diisocyanate is 20%, the rest are the same as in Example 1.

[0052] Example 6

[0053] Except for adjusting the components of the prepolymer in the second component to be: based on the mass of the prepolymer, the mass percentage of polypropylene glycol 1000 is 70%, the mass percentage of modified castor oil is 10%, and the mass percentage of isophorone diisocyanate is 20%. The rest is the same as in Example 1.

[0054] Example 7

[0055] In addition to adjusting the components of the prepolymer in the second component as follows: based on the mass of the prepolymer, the mass percentage of polypropylene glycol 1000 is 35%, the mass percentage of modified castor oil is 5%, and the mass percentage of isophorone diisocyanate is 60%.

[0056] Example 8

[0057] Except for adjusting the mass percentage of each material according to the table above, and replacing the modified castor oil in the first and second components with triethylene glycol-modified castor oil with an average molecular weight of 1200 and an average functionality of 2.6, everything else is the same as in Example 1.

[0058] Example 9

[0059] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0060] Example 10

[0061] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0062] Example 11

[0063] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1. The average molecular weight of the polytetrahydrofuran ether diol is 1000.

[0064] Example 12

[0065] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0066] Example 13

[0067] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0068] Example 14

[0069] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0070] Comparative Example 1

[0071] Except that the isocyanate in the second component of the table above is selected from polymethylene polyphenyl polyisocyanate, the rest is the same as in Example 1.

[0072] Comparative Example 2

[0073] Except for replacing isophorone diisocyanate in the prepolymer of component 2 in the table above with liquefied diphenylmethane diisocyanate, the rest is the same as in Example 1.

[0074] Comparative Example 3

[0075] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0076] Comparative Example 4

[0077] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0078] Comparative Example 5

[0079] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0080] Comparative Example 6

[0081] Except for adjusting the relevant parameters according to the table above, everything else is the same as in Example 1.

[0082] Table 1 shows the test results for each embodiment and comparative example.

[0083] Table 1

[0084] As can be seen from Examples 1 to 14 and Comparative Examples 1 to 6, by selecting the first and second components within the scope of this application and controlling the mass percentage content of each substance in the first and second components within the scope of this application, the first and second components work synergistically to obtain a two-component polyurethane adhesive that has both a long working time and can rapidly cure at room temperature in a short time to produce high initial strength, while also taking into account final strength. This is beneficial for improving production efficiency and reducing energy consumption. Comparative Example 1 did not use isocyanates within the scope of this application. Although the resulting two-component polyurethane adhesive produced high initial strength within 40 minutes, its working time was short, only 10 minutes. The excessively short working time would prevent the adhesive from being applied completely. The reactants of the prepolymer in the second component of Comparative Example 2 did not include diisocyanates within the scope of this application. Although the resulting two-component polyurethane adhesive produced high initial strength within 40 minutes, its working time was short, only 12 minutes. The excessively short working time would prevent the adhesive from being applied completely. In Comparative Example 3, the mass percentages of prepolymer and isocyanate in the second component are outside the scope of this application. Although the resulting two-component polyurethane adhesive has a long working time, its initial solid strength after 40 minutes is only 0.2, which does not meet the application requirements. In Comparative Example 4, the mass percentages of the first and second resins in the first component are outside the scope of this application. Although the resulting two-component polyurethane adhesive has a long working time, its initial solid strength after 40 minutes is only 0.1, which does not meet the application requirements. In Comparative Example 5, the mass percentages of prepolymer and isocyanate in the second component are outside the scope of this application. Although the resulting two-component polyurethane adhesive has a high initial solid strength within 40 minutes, its working time is short, only 18 minutes. This short working time will prevent complete application. In Comparative Example 6, the mass percentages of the first and second resins in the first component are outside the scope of this application. Although the resulting two-component polyurethane adhesive has a long working time, its initial solid strength after 40 minutes is only 0.4, which does not meet the application requirements.

[0085] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A two-component polyurethane adhesive comprising a first component and a second component, wherein, The first component comprises 15wt%–40wt% of a first resin, 15wt%–40wt% of a second resin, 20wt%–50wt% of a first filler, 2wt%–8wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst; the second component comprises 10wt%–40wt% of a prepolymer, 10wt%–40wt% of an isocyanate, 20wt%–40wt% of a second filler, 3wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent. The first resin is selected from at least one of modified castor oil, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, and polycarbonate diol. The second resin is selected from at least one of bisphenol A polyoxypropylene ether, polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether diol, polycaprolactone diol, and polycarbonate diol; The first resin and the second resin are selected from different substances; The prepolymer is selected from the reaction product of polyol and diisocyanate, wherein the polyol is selected from at least one of polyethylene glycol, polypropylene glycol, polytetrahydrofuran ether glycol, polycaprolactone diol, polycarbonate diol, castor oil and modified castor oil, and the diisocyanate is selected from at least one of isophorone diisocyanate and dicyclohexylmethane diisocyanate. The isocyanate is selected from hexamethylene diisocyanate trimer.

2. The two-component polyurethane adhesive according to claim 1, wherein, The first component comprises 20wt%–40wt% of a first resin, 18wt%–40wt% of a second resin, 30wt%–40wt% of a first filler, 2wt%–5wt% of a dehydrating agent, 0.5wt%–2wt% of an anti-settling agent, and 0.2wt%–2wt% of a catalyst; the second component comprises 12wt%–40wt% of a prepolymer, 12wt%–40wt% of an isocyanate, 20wt%–30wt% of a second filler, 5wt%–20wt% of a flame retardant, and 0.2wt%–2wt% of an anti-settling agent.

3. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The modified castor oil is produced by modifying castor oil with at least one selected from polyethylene glycol, polyether diol, small molecule polyol and soybean oil, and the modified castor oil has an average functionality of 2.5 to 3.

4. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The modified castor oil has a number average molecular weight of 1000-2000.

5. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, triethylamine chelate, diethylenetriamine, and triethylenediamine.

6. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The first filler is selected from at least one of aluminum hydroxide, calcium carbonate, bentonite and silica; the dehydrating agent is selected from at least one of molecular sieve, p-toluenesulfonyl isocyanate, triethyl orthoformate and 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine; and the anti-settling agent is selected from at least one of fumed silica and paraffin.

7. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The prepolymer is selected from the reaction products of polypropylene glycol, modified castor oil and isophorone diisocyanate; the mass percentage of the polypropylene glycol is 30% to 70% based on the mass of the prepolymer; the mass percentage of the modified castor oil is 5% to 30%; and the mass percentage of the isophorone diisocyanate is 20% to 60%.

8. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The flame retardant is selected from at least one of antimony trioxide, magnesium hydroxide, aluminum hydroxide, antimony oxide and red phosphorus.

9. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The second filler is selected from at least one of aluminum oxide, calcium carbonate, bentonite and silicon dioxide.

10. The two-component polyurethane adhesive according to claim 1 or 2, wherein, The first component further comprises a first pigment, and the mass percentage of the first pigment is 0.1wt% to 2wt% based on the mass of the first component; and the second component further comprises a second pigment, and the mass percentage of the second pigment is 0.1wt% to 1wt% based on the mass of the second component.

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