Two-component lightweight structural adhesive composition and method of making and use of bonded structures

Abstract

The application discloses a two-component lightweight structural adhesive composition and a manufacturing method and application of a bonded structure. The two-component lightweight structural adhesive composition comprises a first component and a second component; the first component comprises a polyol, a catalyst and a first filler, the second component comprises an isocyanate prepolymer, a second filler and an additive; the isocyanate prepolymer is selected from isocyanate prepolymers with multiple saturated cycloalkyl groups, the second filler is selected from hollow glass microspheres with long carbon chains on the surface, and the additive is selected from organic acids. By using the isocyanate prepolymer with multiple saturated cycloalkyl groups and the hollow glass microspheres with long carbon chains on the surface, and by neutralizing the alkalinity of the hollow glass microspheres with the organic acid, the reaction of the isocyanate is inhibited, a lightweight polyurethane structural adhesive composition can be obtained, the long-term storage viscosity is stable, and in application, the formed adhesive layer is not prone to generating pores, and has very excellent application effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesives, in particular to a two-component lightweight structural adhesive composition and a method for manufacturing a bonded structure and application thereof. BACKGROUND

[0002] Since 2021, the sales proportion of new energy vehicles has reached 13.4% of the total vehicle quantity. In order to solve the range anxiety of users, the energy density demand of power batteries is higher and higher. The structural design of power batteries has evolved from the original CTM battery cell to the module, and different structural types such as CTP (1st generation, 2nd generation, 3rd generation), CTB, CTC have been evolved.

[0003] Whether it is a traditional automobile or a new energy automobile, it is committed to the lightweight of the whole vehicle, so as to reduce energy consumption. In order to further improve the cruising range of electric vehicles, it is necessary to reduce the use of structural parts and other components as much as possible in a limited space, improve the space utilization rate, and place more power batteries. This means that more adhesives are needed to replace rivets and bolts and other structural parts.

[0004] Using polyurethane as a structural adhesive has better toughness and impact resistance, and has good bonding effect on most substrates. The prior art provides some technical solutions of lightweight two-component polyurethane structural adhesive. Some of the technical solutions use hollow glass microspheres as fillers to reduce the density of the structural adhesive.

[0005] However, the inventors of the present application found in long-term practice that hollow glass microspheres as optional low-density fillers can easily cause the viscosity of the isocyanate component to increase during storage due to the presence of a large number of hydroxyl groups on the surface and the pH value of 9.5-10. In addition, during application, the adhesive layer is extremely prone to forming pores, thereby affecting the application effect of the two-component polyurethane structural adhesive. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a two-component lightweight structural adhesive composition and a method for manufacturing a bonded structure and application thereof.

[0007] To achieve the foregoing purpose of the application, the technical solutions adopted by the present application include:

[0008] In a first aspect, the present application provides a two-component lightweight structural adhesive composition, comprising a first component and a second component; the first component comprises a polyol, a catalyst and a first filler, and the second component comprises an isocyanate prepolymer, a second filler and an auxiliary agent.

[0009] The isocyanate prepolymer has a plurality of saturated cycloalkyl groups, the second filler is selected from hollow glass microspheres with long carbon chains on the surface, and the auxiliary agent is selected from organic acids.

[0010] In a second aspect, the present application also provides a method for manufacturing an adhesive structure, comprising the following steps:

[0011] providing the above-mentioned two-component lightweight structural adhesive composition;

[0012] uniformly mixing the first component and the second component in the two-component lightweight structural adhesive composition to obtain an adhesive mixture;

[0013] applying the adhesive mixture to a position to be bonded and drying and curing to form an adhesive structure.

[0014] In a third aspect, the present application also provides a battery pack comprising a plurality of battery cells, wherein the adhesive structure for fixing the plurality of battery cells is formed by the above-mentioned manufacturing method.

[0015] Compared with the prior art, the present application has at least the following beneficial effects:

[0016] The two-component lightweight structural adhesive composition provided by the present application uses an isocyanate prepolymer having a plurality of saturated naphthenic groups and hollow glass microspheres with long carbon chains on the surface, and neutralizes the alkalinity of the hollow glass microspheres with an organic acid to inhibit the reaction of isocyanate, so that a lightweight polyurethane structural adhesive composition can be obtained, and the composition has stable long-term storage viscosity, and the formed adhesive layer is not prone to generate pores, and has very excellent application effect.

[0017] The above description is only a summary of the technical solutions of the present application, in order to enable those skilled in the art to more clearly understand the technical means of the present application, and can be implemented according to the content of the description, as follows. DETAILED DESCRIPTION

[0018] In view of the deficiencies in the prior art, the present inventors have long studied and practiced to propose the technical solutions of the present application. The present application aims to improve the storage stability of hollow glass microspheres and isocyanate by combining various surface treatment methods. The technical solutions, implementation process and principles will be further explained as follows.

[0019] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0020] Moreover, the use of terms such as "first" and "second", etc., are used herein for purposes of nomenclature only and are not otherwise intended to imply any actual relationship or order between the described components or method steps.

[0021] One aspect of the present embodiments provides a two-component lightweight structural adhesive composition, comprising a first component and a second component; the first component comprises a polyol, a catalyst and a first filler, the second component comprises an isocyanate prepolymer, a second filler and an auxiliary agent; the isocyanate prepolymer has a plurality of saturated cycloalkyl groups, the second filler is selected from hollow glass microspheres with long carbon chains on the surface, and the auxiliary agent is selected from organic acids.

[0022] In the above technical solution, the isocyanate prepolymer with saturated cycloalkyl groups is used, which has better permanent adhesion, mechanical properties, hydrolysis resistance and aging resistance than aromatic groups, which greatly helps the performance of the structural adhesive composition finally prepared by the present embodiments.

[0023] In some embodiments, the first component specifically comprises the following components calculated by mass fraction:

[0024] Polyol 80-95wt%, catalyst 0.02-1wt%, color paste 0.02-1wt%, molecular sieve 3-6wt%, fumed silica 0.5-3wt%, first filler 5-10wt%.

[0025] In some embodiments, the second component specifically comprises the following components calculated by mass fraction:

[0026] Isocyanate prepolymer: 45-55wt%; plasticizer: 3-6wt%; fumed silica: 0.5-3wt%; second filler: 45-55wt%; auxiliary agent: 0.5-1wt%.

[0027] In some embodiments, the isocyanate prepolymer is selected from HMDI type isocyanate prepolymer.

[0028] In some embodiments, the organic acid includes any one or a combination of the two of glacial acetic acid and oxalic acid.

[0029] In some embodiments, the hollow glass microspheres have a group as shown in formula (a) on the surface:

[0030]

[0031] wherein R1 is selected from C8-C 18 straight-chain or branched alkyl, preferably -(CH2)7CH3, -(CH2) 11CH3, -(CH2) 17 CH3, -(CH2)

[0032] In some embodiments, the average particle size of the hollow glass microsphere is 30-50 μm, preferably 40 μm, and the porosity is 25-50%, preferably 30-50%.

[0033] In some embodiments, the polyol includes any one or a combination of two or more of polyether polyol and polyester polyol, with a molecular weight of 200-4000 and a functionality of 2-3.

[0034] In some embodiments, the catalyst includes any one or a combination of two or more of organic tin, organic bismuth and organic titanium, preferably in a ratio of 1:1-1.5.

[0035] As some typical application examples of the above technical solution, a two-component lightweight polyurethane structural adhesive composition is composed of component A and component B:

[0036] Component A includes the following raw materials in parts by weight:

[0037] Polyol, 80-95 wt%.

[0038] Catalyst, 0.02-1 wt%.

[0039] Color paste, 0.02-1 wt%.

[0040] Molecular sieve, 3-6 wt%.

[0041] Fumed silica, 0.5-3 wt%.

[0042] Filler, 5-10 wt%.

[0043] Component B includes the following raw materials in parts by weight:

[0044] Isocyanate prepolymer, 45-55 wt%.

[0045] Plasticizer, 3-6 wt%.

[0046] Fumed silica, 0.5-3 wt%.

[0047] Filler, 45-55 wt%.

[0048] Auxiliary agent, 0.5-1%.

[0049] The selected isocyanate prepolymer is one of HMDI type prepolymers.

[0050] The selected auxiliary agent is glacial acetic acid.

[0051] The surface of the selected filler should have groups with the following structure:

[0052]

[0053] wherein: R2 is selected from -OCH3 or -OCH2CH3, and R1 is selected from -(CH2)7CH3, -(CH2) 11 -(CH2) 17 one of the -CH3 groups.

[0054] Another aspect of the embodiments of the present application provides a method for manufacturing an adhesive structure, comprising the following steps:

[0055] Providing the two-component lightweight structural adhesive composition provided by any of the above embodiments.

[0056] Mixing the first component and the second component of the two-component lightweight structural adhesive composition uniformly to obtain an adhesive mixture.

[0057] Placing the adhesive mixture on a position to be bonded and drying and curing to form an adhesive structure.

[0058] In some embodiments, the volume ratio of the first component and the second component is 0.8:1-1.2:1, preferably 1:1.

[0059] In some embodiments, the temperature of the drying and curing is 80-90℃, and the time is 2-3h.

[0060] In some embodiments, the shear strength of the adhesive structure is above 10MPa.

[0061] In some embodiments, the density of the adhesive structure is 1g / cm 3 The following.

[0062] Still another aspect of the embodiments of the present application also provides a battery pack comprising a plurality of battery cells, wherein the adhesive structure for fixing the plurality of battery cells is formed by the manufacturing method provided by any of the above embodiments.

[0063] The technical solutions of the present application are further described in detail through several embodiments. However, the selected embodiments are only used to illustrate the present application, and do not limit the scope of the present application.

[0064] Embodiment 1

[0065] This embodiment exemplifies a two-component lightweight structural adhesive composition, its preparation process, and corresponding adhesive performance and storage performance tests, as shown below:

[0066] The A component and the B component were uniformly mixed according to the corresponding proportions in Table 1 below, and then the A component and the B component were uniformly mixed at a mass ratio of 1:1 to prepare a shear sample, and the shear strength was tested after oven curing at 80°C for 2h, and the specific test data are shown in Table 2.

[0067] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested, and the test results are also shown in Table 2.

[0068] Example 2

[0069] This example illustrates a two-component lightweight structural adhesive composition, its preparation process, and corresponding bonding performance and storage performance tests, as follows:

[0070] The A component and the B component were uniformly mixed according to the corresponding proportions in Table 1 below, and then the A component and the B component were uniformly mixed at a mass ratio of 1:1 to prepare a shear sample, and the shear strength was tested after oven curing at 80°C for 2h, and the specific test data are shown in Table 2.

[0071] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested, and the test results are also shown in Table 2.

[0072] Example 3

[0073] This example illustrates a two-component lightweight structural adhesive composition, its preparation process, and corresponding bonding performance and storage performance tests, as follows:

[0074] The A component and the B component were uniformly mixed according to the corresponding proportions in Table 1 below, and then the A component and the B component were uniformly mixed at a mass ratio of 1:1 to prepare a shear sample, and the shear strength was tested after oven curing at 80°C for 2h, and the specific test data are shown in Table 2.

[0075] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested, and the test results are also shown in Table 2.

[0076] Comparative Example 1

[0077] This example illustrates a two-component lightweight structural adhesive composition, its preparation process, and corresponding bonding performance and storage performance tests, as follows:

[0078] The A component and the B component were uniformly mixed according to the corresponding proportions in Table 1 below, and then the A component and the B component were uniformly mixed at a mass ratio of 1:1 to prepare a shear sample, and the shear strength was tested after oven curing at 80°C for 2h, and the specific test data are shown in Table 2.

[0079] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested. The test results are also shown in Table 2.

[0080] The main difference between this comparative example and Example 1 is that the surface of the filler does not form long carbon chains, resulting in the inability to form the combined effect of long carbon chains, acidic adjuvants, and saturated cyclic isocyanate.

[0081] Comparative Example 2

[0082] This comparative example illustrates the preparation process of a two-component lightweight structural adhesive composition and the corresponding bonding performance and storage performance tests, as follows:

[0083] According to the corresponding proportions in Table 1 below, the A component and the B component were uniformly mixed, then the A component and the B component were uniformly mixed in a mass ratio of 1:1, shear samples were prepared, and the shear strength was tested after oven curing at 80°C for 2h. The specific test data are shown in Table 2.

[0084] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested. The test results are also shown in Table 2.

[0085] The main difference between this comparative example and Example 1 is that no organic acid is added as an adjuvant, resulting in the inability to form the combined effect of long carbon chains, acidic adjuvants, and saturated cyclic isocyanate.

[0086] Comparative Example 3

[0087] This comparative example illustrates the preparation process of a two-component lightweight structural adhesive composition and the corresponding bonding performance and storage performance tests, as follows:

[0088] According to the corresponding proportions in Table 1 below, the A component and the B component were uniformly mixed, then the A component and the B component were uniformly mixed in a mass ratio of 1:1, shear samples were prepared, and the shear strength was tested after oven curing at 80°C for 2h. The specific test data are shown in Table 2.

[0089] The B component was continuously stored at 50°C for 7 days, and the viscosity of the B component before and after storage was tested. The test results are also shown in Table 2.

[0090] The main difference between this comparative example and Example 1 is that an unsaturated MDI type isocyanate prepolymer is used, resulting in the inability to form the combined effect of long carbon chains, acidic adjuvants, and saturated cyclic isocyanate.

[0091] Table 1: Proportions of two-component lightweight structural adhesive compositions in examples and comparative examples

[0092]

[0093] Table 2 Adhesion and storage performance test results of two-component lightweight structural adhesive compositions in examples and comparative examples

[0094]

[0095] It should be noted that in Table 1: the polyether polyol is a PO type polyether polyol with a molecular weight of 400-5000, a functionality of 2 and / or 3, a low molecular weight polyether polyol with low viscosity and fast reaction speed, a high molecular weight flexible good, slow reaction, 2 functionality linear structure, providing flexibility, 3 functionality forming a crosslinked system, network structure, providing cohesive strength.

[0096] The polyester polyol is a dimer acid and / or bisphenol A modified polyester polyol with a molecular weight of 1000-3000 and a functionality of 2.

[0097] The catalyst is a complex of one or both of organic titanium and organic bismuth, preferably with a complex ratio of 3:4.

[0098] The isocyanate prepolymer-1 is an HMDI type isocyanate prepolymer.

[0099] The isocyanate prepolymer-2 is an MDI type isocyanate prepolymer.

[0100] The filler-1 is a hollow glass microsphere with a surface substituent R1 of -(CH2)7CH3 and R2 of -OCH2CH3.

[0101] The filler-2 is a hollow glass microsphere with a surface substituent R1 of -(CH2) 11 CH3 and R2 of -OCH3.

[0102] The filler-3 is a hollow glass microsphere with a surface substituent R1 of -(CH2) 17 CH3 and R2 of -OCH3.

[0103] The filler-4 is a hollow glass microsphere without a surface substituent.

[0104] Based on the above test results, it can be determined that the isocyanate composition provided by the examples of the present application selects an HMDI type isocyanate, the surface of the selected filler has a long carbon chain substituent group, and an organic acid is used as an additive, the shear strength of the prepared two-component polyurethane structural adhesive reaches 10 MPa, the density is less than or equal to 1 g / cm 3 , and the viscosity remains stable for a long time.

[0105] Example 4

[0106] The present embodiment exemplifies a two-component lightweight structural adhesive composition, its preparation process, and corresponding bonding performance and storage performance tests, which are substantially the same as those of Embodiment 1, with the main difference being that:

[0107] The acetic acid used in Embodiment 1 is replaced with an equivalent mass fraction of oxalic acid.

[0108] The remaining raw materials and proportions remain unchanged.

[0109] Uniformly mixed to obtain A component and B component, then according to the mass ratio 1:1, the A component and B component are uniformly mixed, then the shear sample is prepared, and the shear strength is tested after 2h oven curing at 80℃, which is almost the same as that of Embodiment 1.

[0110] And the B component is continuously stored at 50℃ for 7 days, and it is observed that the viscosity does not change significantly after storage, and there is no sign of any curing.

[0111] Therefore, it can be clearly seen that the two-component lightweight structural adhesive composition provided by the embodiments of the present application can obtain a lightweight polyurethane structural adhesive composition by using an isocyanate prepolymer with multiple saturated naphthenic groups and using hollow glass microspheres with long carbon chains on the surface, and by neutralizing the alkalinity of the hollow glass microspheres with organic acid to inhibit the reaction of isocyanate, while the composition has stable long-term storage viscosity, and in application, the formed adhesive layer is not prone to produce pores, and has very excellent application effect.

[0112] It should be understood that the above embodiments are only for illustrating the technical concepts and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A two-component lightweight structural adhesive composition, comprising a first component and a second component; the first component comprising a polyol, a catalyst, and a first filler, and the second component comprising an isocyanate prepolymer, a second filler, and additives; Its features are, The isocyanate prepolymer has multiple saturated cycloalkyl groups, the second filler is selected from hollow glass microspheres with long carbon chains on the surface, and the auxiliary agent is selected from organic acids, which neutralize the alkalinity of the hollow glass microspheres and inhibit the reaction of the isocyanate prepolymer. The first component specifically includes the following components calculated by mass fraction: Polyols 80-95 wt%, catalysts 0.02-1 wt%, color pastes 0.02-1 wt%, molecular sieves 3-6 wt%, fumed silica 0.5-3 wt%, primary packing material 5-10 wt%; The second component specifically includes the following components calculated by mass fraction: Isocyanate prepolymer: 45-55 wt% Plasticizer: 3-6 wt% Fumed silica: 0.5-3 wt%; Secondary filler: 45-55 wt% Additives: 0.5-1 wt% The surface of the hollow glass microspheres has groups as shown in formula (a): ; Among them, R1 is selected from C8-C 18 The straight-chain or branched alkyl group, R2 is selected from -OCH3 and / or -OCH2CH3.

2. The two-component lightweight structural adhesive composition according to claim 1, characterized in that, The isocyanate prepolymer is selected from HMDI type isocyanate prepolymers.

3. The two-component lightweight structural adhesive composition according to claim 1, characterized in that, The organic acid includes any one or a combination of two of glacial acetic acid and oxalic acid.

4. The two-component lightweight structural adhesive composition according to claim 1, characterized in that, R1 is selected from -(CH2)7CH3 and -(CH2). 11 CH3, -(CH2) 17 Any one of the CH3 types.

5. The two-component lightweight structural adhesive composition according to claim 1, characterized in that, The hollow glass microspheres have an average particle size of 30-50 μm and a porosity of 30-50%.

6. The two-component lightweight structural adhesive composition according to claim 1, characterized in that, The polyol includes any one or a combination of two of polyether polyols and polyester polyols.

7. The two-component lightweight structural adhesive composition according to claim 6, characterized in that, The polyol has a molecular weight of 200-4000 and a functionality of 2-3. And / or, the catalyst comprises any one or a combination of two or more of organotin, organobismuth, and organotitanium.

8. A method for manufacturing an adhesive structure, characterized in that, include: Provide a two-component lightweight structural adhesive composition according to any one of claims 1-7; The first component and the second component of the two-component lightweight structural adhesive composition are uniformly mixed to obtain an adhesive mixture. The adhesive mixture is applied to the bonding area and dried and cured to form an adhesive structure.

9. A battery pack comprising a plurality of battery cells, characterized in that, The bonding structure that fixes the plurality of said battery cells is formed by the manufacturing method of claim 8.

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