High-heat-resistant two-component polyurethane structural adhesive for power battery and preparation method thereof

Abstract

A high-heat-resistant two-component polyurethane structural adhesive for power batteries, which is composed of component A and component B in a volume ratio of (0.8-1.2):1; the component A is prepared from raw materials including castor oil 25 parts by weight, modified castor oil 10-40 parts by weight, chain extender 1-10 parts by weight, aluminum hydroxide flame-retardant powder 30-80 parts by weight, white carbon black thixotropic agent 1-5 parts by weight, adhesion promoter 0.5-3 parts by weight, metal catalyst 0.05-0.5 parts by weight, and yellow color paste 0.1-1 part by weight; the component B is prepared from raw materials including diisocyanate 30 parts by weight, polycarbonate diol 5-20 parts by weight, polyether glycol 3-15 parts by weight, aluminum hydroxide flame-retardant powder 30-80 parts by weight, white carbon black thixotropic agent 1-5 parts by weight, water absorption agent 0.5-3 parts by weight, and blue color paste 0.1-1 part by weight. The high-heat-resistant two-component polyurethane structural adhesive for power batteries uses specific components with specific contents, realizes good overall interaction, has high-temperature resistance and good flexibility, and is suitable for power battery PACK packaging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane glue, more particularly to a high-heat-resistant two-component polyurethane structural glue for power batteries and a preparation method thereof. BACKGROUND

[0002] At present, in the field of power battery PACK packaging, the two-component polyurethane structural glue mainly plays a role in bonding and fixing. Previously, battery factories mainly focused on the performance of the body strength, elongation at break, shear strength and the like of a two-component polyurethane structural glue at room temperature when evaluating the two-component polyurethane structural glue, and judged whether a product was suitable according to the performance. However, in fact, the temperature of the battery during normal use is about 50℃ to 60℃, and the mechanical properties tested at room temperature cannot represent the data of the two-component polyurethane structural glue at high temperature. On the contrary, the two-component polyurethane glue products on the market all show the characteristics of not being resistant to high temperature, and the shear strength at high temperature is often only 20% to 30% of the shear strength at room temperature, which will bring significant hidden dangers. Therefore, how to improve the mechanical properties of the two-component polyurethane glue at high temperature (50℃ to 60℃) is a problem that needs to be solved, and the battery factories have gradually paid attention to this problem.

[0003] Intuitively, to improve the high-temperature resistance of the polyurethane glue, rigid structures can be introduced into the molecular chain segments or the crosslinking density of the product can be improved, so that the glass transition temperature of the product can be improved, and then the product has higher mechanical strength and elastic modulus at high temperature. However, blindly improving the structural rigidity and the glass transition temperature will cause the brittleness to increase and the toughness to decrease. The introduction of too many rigid structures and the increase of the crosslinking density will cause the elongation at break to decrease significantly, and cannot meet the requirements of the battery in the automobile driving in terms of fatigue resistance and stretch resistance. At the same time, the sharp rise of the hardness will also make the glue have the risk of scratching the battery. Therefore, while developing the high-temperature-resistant polyurethane glue, we need to try not to reduce or reduce the flexibility of the product as much as possible, so that the developed product has real practical value. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a high-heat-resistant two-component polyurethane structural glue for power batteries and a preparation method thereof. The high-heat-resistant two-component polyurethane structural glue for power batteries provided by the present application has high-temperature resistance and good flexibility, and is suitable for power battery PACK packaging.

[0005] The present application provides a high-heat-resistant two-component polyurethane structural glue for power batteries, which is composed of an A component and a B component in a volume ratio of (0.8-1.2):1; the A component is prepared from raw materials including the following components:

[0006] castor oil 25 parts by weight;

[0007] modified castor oil 10 parts by weight to 40 parts by weight;

[0008] chain extender 1 part by weight to 10 parts by weight;

[0009] aluminum hydroxide flame retardant powder 30 parts by weight to 80 parts by weight;

[0010] white carbon touch agent 1 part by weight to 5 parts by weight;

[0011] adhesion promoter 0.5 parts by weight to 3 parts by weight;

[0012] metal catalyst 0.05 parts by weight to 0.5 parts by weight;

[0013] yellow paste 0.1 parts by weight to 1 part by weight;

[0014] The B component is prepared from raw materials comprising the following components:

[0015] diisocyanate 30 parts by weight;

[0016] polycarbonate diol 5 parts by weight to 20 parts by weight;

[0017] polyether diol 3 parts by weight to 15 parts by weight;

[0018] aluminum hydroxide flame retardant powder 30 parts by weight to 80 parts by weight;

[0019] white carbon touch agent 1 part by weight to 5 parts by weight;

[0020] water absorption agent 0.5 parts by weight to 3 parts by weight;

[0021] blue paste 0.1 parts by weight to 1 part by weight.

[0022] Preferably, the modified castor oil is selected from one or more of ITO AC-006 modified castor oil, ITO AC-009 modified castor oil, and VARTUS M-365 modified castor oil.

[0023] Preferably, the chain extender is selected from 2-ethyl-1,3-hexanediol and / or 2-butyl-2-ethyl-1,3-propanediol.

[0024] Preferably, the aluminum hydroxide flame retardant powder is selected from JINGO JAZ-119 and / or XUSON XS-AWC-505D.

[0025] The white carbon touch agent is selected from CABOT TS720 and / or WINGATE R202.

[0026] Preferably, the adhesion promoter is selected from BYK-4510 and / or BYK-4511.

[0027] Preferably, the metal catalyst is a Vantrus Coscat-83 organic bismuth catalyst.

[0028] Preferably, the diisocyanate is selected from one or more of Wanhua diphenylmethane diisocyanate, liquefied diphenylmethane diisocyanate, carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate;

[0029] The polyether diol is selected from one or more of Wanhua C2020, East Big DL2000, East Big DL1000.

[0030] Preferably, the polycarbonate diol is selected from one or more of Asahi Kasei T5652, Asahi Kasei T5651, Asahi Kasei T5650J.

[0031] Preferably, the water absorbing agent is Borchers TI water absorbing agent.

[0032] The application also provides a preparation method of the high-heat-resistant two-component polyurethane structural adhesive for power batteries, comprising the following steps:

[0033] a) heat castor oil, modified castor oil, chain extender, aluminum hydroxide flame retardant powder and white carbon black thixotropic agent to 110-130 DEG C under stirring at 100-300 rpm, vacuumize to below-0.09 MPa for 1.5-2.5 h of dehydration, then cool to below 50 DEG C to add adhesion promoter, metal catalyst and yellow paste, vacuumize to below-0.09 MPa and continue stirring at 50-150 rpm for 0.5-1 h to obtain component A;

[0034] b) dry and dehydrate aluminum hydroxide flame retardant powder and white carbon black thixotropic agent in an oven at 90-110 DEG C for 20-30 h for standby; stir diisocyanate, polycarbonate diol and polyether diol at 20-30 DEG C at 50-150 rpm and vacuumize to-0.1 to-0.08 MPa for 1-3 h of reaction, then add the previously dried aluminum hydroxide flame retardant powder and white carbon black thixotropic agent, add water absorbing agent and blue paste, stir at 20-30 DEG C at 150-250 rpm and vacuumize to-0.1 to-0.08 MPa for 0.5-1.5 h of reaction to obtain component B;

[0035] c) mix the above-mentioned component A and component B uniformly to obtain the high-heat-resistant two-component polyurethane structural adhesive for power batteries;

[0036] The step a) and step b) are not limited in order.

[0037] The application provides a high-heat-resistant two-component polyurethane structural adhesive for power batteries, which is composed of an A component and a B component in a volume ratio of (0.8-1.2):1; the A component is prepared from raw materials including the following components: 25 parts by weight of castor oil; 10-40 parts by weight of modified castor oil; 1-10 parts by weight of a chain extender; 30-80 parts by weight of aluminum hydroxide flame-retardant powder; 1-5 parts by weight of white carbon black thixotropic agent; 0.5-3 parts by weight of an adhesion promoter; 0.05-0.5 parts by weight of a metal catalyst; and 0.1-1 part by weight of yellow paste; and the B component is prepared from raw materials including the following components: 30 parts by weight of diisocyanate; 5-20 parts by weight of polycarbonate diol; 3-15 parts by weight of polyether diol; 30-80 parts by weight of aluminum hydroxide flame-retardant powder; 1-5 parts by weight of white carbon black thixotropic agent; 0.5-3 parts by weight of a water absorption agent; and 0.1-1 part by weight of blue paste. Compared with the prior art, the high-heat-resistant two-component polyurethane structural adhesive for power batteries provided by the application realizes good interaction of the whole product by using specific components with specific contents, and the product has high-temperature resistance and good flexibility, and is suitable for power battery PACK package.

[0038] In addition, the preparation method provided by the application has simple process, mild and easy-to-control conditions, easily available raw materials and low cost, and has wide industrial application prospect. DETAILED DESCRIPTION

[0039] The technical solutions of the application will be described clearly and completely below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0040] The application provides a high-heat-resistant two-component polyurethane structural adhesive for power batteries, which is composed of an A component and a B component in a volume ratio of (0.8-1.2):1; the A component is prepared from raw materials including the following components:

[0041] 25 parts by weight of castor oil;

[0042] 10-40 parts by weight of modified castor oil;

[0043] 1-10 parts by weight of a chain extender;

[0044] 30-80 parts by weight of aluminum hydroxide flame-retardant powder;

[0045] 1-5 parts by weight of white carbon black thixotropic agent;

[0046] adhesion promoter 0.5-3 parts by weight;

[0047] metal catalyst 0.05-0.5 parts by weight;

[0048] yellow paste 0.1-1 parts by weight;

[0049] The B component is prepared from raw materials comprising the following components:

[0050] diisocyanate 30 parts by weight;

[0051] polycarbonate diol 5-20 parts by weight;

[0052] polyether diol 3-15 parts by weight;

[0053] aluminum hydroxide flame-retardant powder 30-80 parts by weight;

[0054] white carbon black thixotropic agent 1-5 parts by weight;

[0055] water absorption agent 0.5-3 parts by weight;

[0056] blue paste 0.1-1 parts by weight.

[0057] The present application aims at the problem that the body strength, shear strength and elastic modulus of existing two-component polyurethane glue significantly decrease at battery use temperature (50-60℃) compared with normal temperature 25℃, and provides a high-heat-resistant two-component polyurethane structural glue for power batteries; the high-heat-resistant two-component polyurethane structural glue for power batteries is composed of A component and B component with a volume ratio of (0.8-1.2):1, preferably 1:1.

[0058] In the present application, the A component is prepared from raw materials comprising the following components:

[0059] castor oil 25 parts by weight;

[0060] modified castor oil 10-40 parts by weight;

[0061] chain extender 1-10 parts by weight;

[0062] aluminum hydroxide flame-retardant powder 30-80 parts by weight;

[0063] white carbon black thixotropic agent 1-5 parts by weight;

[0064] adhesion promoter 0.5-3 parts by weight;

[0065] metal catalyst 0.05-0.5 parts by weight;

[0066] yellow paste 0.1-1 parts by weight;

[0067] Preferably prepared from the following raw materials:

[0068] Castor oil 25 parts by weight;

[0069] Modified castor oil 15 parts by weight to 25 parts by weight;

[0070] Chain extender 5 parts by weight to 7 parts by weight;

[0071] Aluminum hydroxide flame-retardant powder 40 parts by weight to 50 parts by weight;

[0072] White carbon black thixotropic agent 1.5 parts by weight to 2.5 parts by weight;

[0073] Adhesion promoter 0.8 parts by weight to 1.2 parts by weight;

[0074] Metal catalyst 0.08 parts by weight to 0.12 parts by weight;

[0075] Yellow color paste 0.4 parts by weight to 0.6 parts by weight.

[0076] In the present application, the castor oil is unmodified castor oil, and a commercially available product of ordinary castor oil raw material known to those skilled in the art can be used.

[0077] In the present application, the modified castor oil is preferably selected from one or more of ITO AC-006 modified castor oil, ITO AC-009 modified castor oil, and VARTUS M-365 modified castor oil, and more preferably is ITO AC-006 modified castor oil or ITO AC-009 modified castor oil. The present application does not have special restrictions on the source of the modified castor oil, and a commercially available product known to those skilled in the art can be used.

[0078] In the present application, the chain extender is preferably selected from 2-ethyl-1,3-hexanediol (EHD) and / or 2-butyl-2-ethyl-1,3-propanediol (BEPD), and more preferably is 2-ethyl-1,3-hexanediol or 2-butyl-2-ethyl-1,3-propanediol. The present application does not have special restrictions on the source of the chain extender, and a commercially available product known to those skilled in the art can be used.

[0079] In the present application, the aluminum hydroxide flame-retardant powder is selected from JINGE JAZ-119 and / or XUSON XS-AWC-505D, and more preferably is JINGE JAZ-119 or XUSON XS-AWC-505D; and the white carbon black thixotropic agent is preferably selected from CABOT TS720 and / or WINCRE R202, and more preferably is CABOT TS720 or WINCRE R202. The present application does not have special restrictions on the source of the aluminum hydroxide flame-retardant powder and the white carbon black thixotropic agent, and a commercially available product known to those skilled in the art can be used.

[0080] In the present application, the adhesion promoter is preferably selected from BYK-4510 and / or BYK-4511, more preferably BYK-4510 or BYK-4511. The present application does not have a special limitation on the source of the adhesion promoter, and a commercially available product well known to those skilled in the art can be used.

[0081] In the present application, the metal catalyst is preferably Coscat-83 organic bismuth catalyst by Vantros; a commercially available source well known to those skilled in the art can be used.

[0082] In the present application, the B component is prepared from raw materials including the following components:

[0083] 30 parts by weight of diisocyanate;

[0084] 5 to 20 parts by weight of polycarbonate diol;

[0085] 3 to 15 parts by weight of polyether diol;

[0086] 30 to 80 parts by weight of aluminum hydroxide flame retardant powder;

[0087] 1 to 5 parts by weight of white carbon black thixotropic agent;

[0088] 0.5 to 3 parts by weight of water absorbing agent;

[0089] 0.1 to 1 part by weight of blue paste;

[0090] Preferably prepared from raw materials including the following components:

[0091] 30 parts by weight of diisocyanate;

[0092] 10 to 18 parts by weight of polycarbonate diol;

[0093] 4 to 12 parts by weight of polyether diol;

[0094] 40 to 50 parts by weight of aluminum hydroxide flame retardant powder;

[0095] 1.5 to 2.5 parts by weight of white carbon black thixotropic agent;

[0096] 0.8 to 1.2 parts by weight of water absorbing agent;

[0097] 0.4 to 0.6 parts by weight of blue paste.

[0098] In the present application, the diisocyanate is preferably selected from one or more of Wanhua diphenylmethane diisocyanate (MDI-100), liquefied diphenylmethane diisocyanate (MDI-50), and carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate (MDI-100L), more preferably Wanhua diphenylmethane diisocyanate (MDI-100), liquefied diphenylmethane diisocyanate (MDI-50), or carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate (MDI-100L). The present application does not have special restrictions on the source of the diisocyanate, and commercially available products known to those skilled in the art can be used.

[0099] In the present application, the polycarbonate diol is preferably selected from one or more of Asahi Kasei T5652, Asahi Kasei T5651, and Asahi Kasei T5650J, more preferably Asahi Kasei T5652, Asahi Kasei T5651, or Asahi Kasei T5650J. The present application does not have special restrictions on the source of the polycarbonate diol, and commercially available products known to those skilled in the art can be used.

[0100] In the present application, the polyether diol is preferably selected from one or more of Wanhua C2020, Toagosei DL2000, and Toagosei DL1000, more preferably Wanhua C2020, Toagosei DL2000, or Toagosei DL1000. The present application does not have special restrictions on the source of the polyether diol, and commercially available products known to those skilled in the art can be used.

[0101] In the present application, the aluminum hydroxide flame-retardant powder and fumed silica thixotropic agent are the same as described in the above technical solution, and will not be repeated here.

[0102] In the present application, the water-absorbing agent is preferably Borchers TI water-absorbing agent; commercially available products of the above-mentioned monofunctional small molecule isocyanate water-absorbing agent known to those skilled in the art can be used.

[0103] The high-heat-resistant two-component polyurethane structural adhesive for power batteries provided by the application realizes good overall interaction by using specific components with specific contents, and the high-heat-resistant two-component polyurethane structural adhesive for power batteries provided by the application has high-temperature resistance and good flexibility, and is suitable for power battery PACK packaging.

[0104] The application further provides a preparation method of the high-heat-resistant two-component polyurethane structural adhesive for power batteries.

[0105] a) heating castor oil, modified castor oil, a chain extender, aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent to 110-130 DEG C under stirring at 100-300 rpm, vacuumizing to below-0.09 MPa for dehydration for 1.5-2.5 h, then cooling to below 50 DEG C to add adhesion promoter, metal catalyst and yellow color paste, vacuumizing to below-0.09 MPa to continue stirring at 50-150 rpm for 0.5-1 h to obtain component A;

[0106] b) drying and dehydrating aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent in an oven at 90-110 DEG C for 20-30 h for standby; stirring diisocyanate, polycarbonate diol and polyether diol at 20-30 DEG C and 50-150 rpm and vacuumizing to-0.1 to-0.08 MPa for 1-3 h, then adding the dried aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent, adding water absorber and blue color paste, stirring at 20-30 DEG C and 150-250 rpm and vacuumizing to-0.1 to-0.08 MPa for 0.5-1.5 h to obtain component B (realizing preparation of polycarbonate prepolymer);

[0107] c) mixing the above-mentioned component A and component B uniformly to obtain the high-heat-resistant two-component polyurethane structural adhesive for power batteries;

[0108] The step a) and step b) are not limited in sequence.

[0109] The preparation method provided by the application improves the high-temperature resistance of the adhesive by introducing a polycarbonate prepolymer structure into the formula, and has the advantages of simple process, mild and easy-to-control conditions, easily available raw materials, low cost and wide industrial application prospect.

[0110] The application provides a high-heat-resistant two-component polyurethane structural adhesive for power batteries, which is composed of an A component and a B component in a volume ratio of (0.8-1.2):1.

[0111] In addition, the preparation method provided by the application has the advantages of simple process, mild and easy-to-control conditions, easily available raw materials, low cost and wide industrial application prospect.

[0112] In order to further illustrate the application, the following examples are used for detailed description. The raw materials used in the following examples of the application are all commercially available, and include:

[0113] (modified) castor oil: castor oil, Ito AC-006 modified castor oil, Ito AC-009 modified castor oil and Valtorus M-365 modified castor oil;

[0114] Chain extender: 2-ethyl-1,3-hexanediol (EHD), 2-butyl-2-ethyl-1,3-propanediol (BEPD);

[0115] Diisocyanate: Wanhua diphenylmethane diisocyanate (MDI-100), liquefied diphenylmethane diisocyanate MDI-50, carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate (MDI-100L);

[0116] Polyether diol: Wanhua C2020, Dongda DL2000 and Dongda DL1000;​​​​​​​​​​​​​​

[0117] Polycarbonate diol: Asahi Kasei T5652, Asahi Kasei T5651 and Asahi Kasei T5650J;

[0118] Aluminum hydroxide flame-retardant powder: Jinggo JAZ-119 and Xingsen XS-AWC-505D;

[0119] White carbon black thixotropic agent: CABOT TS720 and Wincell R202;

[0120] Adhesion promoter: BYK-4510 and BYK-4511;

[0121] Metal catalyst: Vantrus Coscat-83 organic bismuth catalyst;

[0122] Water absorption agent: Borchers TI (monofunctional small molecule isocyanate);

[0123] Color paste: Boma blue color paste and yellow color paste.

[0124] The preparation method of the following examples of the present application comprises the following steps:

[0125] (1) Component A:

[0126] The castor oil, modified castor oil, chain extender, aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent are heated to 120°C under stirring at 200 rpm, vacuumized to below -0.09 MPa for 2 h of dehydration, and then cooled to below 50°C to add the adhesion promoter, metal catalyst and yellow color paste, vacuumized to below -0.09 MPa for 45 min of continuous stirring at 100 rpm, to obtain component A.

[0127] (2) Component B:

[0128] The aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent are dried by oven drying at 100°C for 24 h, ready for use; the diisocyanate, polycarbonate diol and polyether diol are stirred at 100 rpm at room temperature and vacuumized to -0.09 MPa for 2 h of reaction, followed by adding the pre-dried aluminum hydroxide flame-retardant powder and white carbon black thixotropic agent, adding the water absorption agent and blue color paste, stirring at 200 rpm at room temperature and vacuumizing to -0.09 MPa for 1 h of reaction, to obtain component B.

[0129] (3) The above-mentioned component A and component B are mixed uniformly according to the volume ratio of 1:1, to obtain a two-component polyurethane structural adhesive.

[0130] Example 1

[0131] A component: castor oil 25 parts by weight, Ito AC-006 modified castor oil 20 parts by weight, 2-ethyl-1, 3-hexanediol 6 parts by weight, Kingfa JAZ-119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, BYK-4510 adhesion promoter 1 part by weight, Vantros Coscat-83 metal catalyst 0.1 part by weight, Boma yellow paste 0.5 part by weight;

[0132] B component: Wanhua MDI-100 diphenyl methane diisocyanate 30 parts by weight, Asahi Kasei T5652 polycarbonate diol 10 parts by weight, Wanhua C2020 polyether diol 12 parts by weight, Kingfa JAZ119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, Borchers TI water absorbent 1 part by weight, Boma blue paste 0.5 part by weight.

[0133] The two-component polyurethane structural adhesive is prepared according to the above preparation method.

[0134] Example 2

[0135] A component: castor oil 25 parts by weight, Ito AC-009 modified castor oil 20 parts by weight, 2-ethyl-1, 3-hexanediol 6 parts by weight, Kingfa JAZ-119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, BYK-4510 adhesion promoter 1 part by weight, Vantros Coscat-83 metal catalyst 0.1 part by weight, Boma yellow paste 0.5 part by weight;

[0136] B component: Wanhua MDI-50 liquefied diphenyl methane diisocyanate 30 parts by weight, Asahi Kasei T5651 polycarbonate diol 14 parts by weight, Tokiwa DL1000 polyether diol 8 parts by weight, Kingfa JAZ-119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, Borchers TI water absorbent 1 part by weight, Boma blue paste 0.5 part by weight.

[0137] The two-component polyurethane structural adhesive is prepared according to the above preparation method.

[0138] Example 3

[0139] A component: castor oil 25 parts by weight, Ito AC-009 modified castor oil 20 parts by weight, 2-butyl-2-ethyl-1,3-propanediol 6 parts by weight, Asahi Sunacs XS-AWC-505D aluminum hydroxide flame retardant powder 45 parts by weight, Wanhua R202 white carbon black thixotropic agent 2 parts by weight, BYK-4511 adhesion promoter 1 part by weight, Vantros Coscat-83 metal catalyst 0.1 part by weight, Boma yellow paste 0.5 part by weight;

[0140] B component: Wanhua MDI-100L liquefied diphenyl methane diisocyanate 30 parts by weight, Asahi Kasei T5650J polycarbonate diol 18 parts by weight, Toki DL1000 polyether diol 4 parts by weight, Asahi Sunacs XS-AWC-505D aluminum hydroxide flame retardant powder 45 parts by weight, Wanhua R202 white carbon black thixotropic agent 2 parts by weight, Borchers TI water absorber 1 part by weight, Boma blue paste 0.5 part by weight.

[0141] The two-component polyurethane structural adhesive is prepared according to the above preparation method.

[0142] Comparative Example 1

[0143] A component: castor oil 25 parts by weight, Ito AC-009 modified castor oil 20 parts by weight, 2-butyl-2-ethyl-1,3-propanediol 6 parts by weight, Asahi Sunacs XS-AWC-505D aluminum hydroxide flame retardant powder 45 parts by weight, Wanhua R202 white carbon black thixotropic agent 2 parts by weight, BYK-4511 adhesion promoter 1 part by weight, Vantros Coscat-83 metal catalyst 0.1 part by weight, Boma yellow paste 0.5 part by weight;

[0144] B component: Wanhua MDI-100 liquefied diphenyl methane diisocyanate 30 parts by weight, Wanhua C2020 polyether diol 22 parts by weight, Janggong JAZ119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, Borchers TI water absorber 1 part by weight, Boma blue paste 0.5 part by weight.

[0145] The two-component polyurethane structural adhesive is prepared according to the above preparation method.

[0146] Comparative Example 2

[0147] A component: castor oil 15 parts by weight, Ito AC-006 modified castor oil 20 parts by weight, Asahi Kasei T5650J polycarbonate diol 10 parts by weight, 2-ethyl-1, 3-hexanediol 6 parts by weight, King Industries JAZ-119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, BYK-4510 adhesion promoter 1 part by weight, Vantros Coscat-83 metal catalyst 0.1 part by weight, Bomaish yellow paste 0.5 parts by weight;

[0148] B component: Wanhua MDI-100 diphenyl methane diisocyanate 30 parts by weight, Wanhua C2020 polyether diol 22 parts by weight, King Industries JAZ119 aluminum hydroxide flame retardant powder 45 parts by weight, CABOT TS720 white carbon black thixotropic agent 2 parts by weight, Borchers TI water absorber 1 part by weight, Bomaish blue paste 0.5 parts by weight.

[0149] The two-component polyurethane structural adhesive is prepared according to the above preparation method.

[0150] The formula table is shown in Table 1 below.

[0151] Table 1 Typical Comparative Experiment

[0152]

[0153]

[0154] In the above experiments, different proportions of polycarbonate diol were added in the preparation of prepolymer in B component in Examples 1-3, while no polycarbonate diol was added in Comparative Example 1, and polycarbonate diol was added in A component in Comparative Example 2.

[0155] The properties of the above two-component polyurethane structural adhesive were tested according to the following test standards.

[0156] Test standards:

[0157] Tensile strength, elongation at break: GB / T 528-2009, Determination of tensile stress-strain properties of vulcanized or thermoplastic rubbers;

[0158] Shear strength: GB / T 7124-2008, Determination of tensile shear strength of adhesives (rigid material to rigid material);

[0159] Elastic modulus: ASTM E1640, Standard Test Method for Assignment of the Glass Transition Temperature By Dynamic Mechanical Analysis.

[0160] The test results are shown in Table 2 below.

[0161] Table 2 Test results

[0162] Performance indicators Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Bulk tensile strength (25°C, MPa) 12.3 14.6 16.5 10.5 10.8 Elongation at break (25°C, %) 87 43 13 120 67 Shear strength (25°C, MPa, Al-Al) 12.9 13.7 13.9 10.3 10.9 Elastic modulus (25°C, MPa) 830 950 1250 650 760 Bulk tensile strength (60°C, MPa) 5.8 6.7 7.4 3.5 4.1 Shear strength (60°C, MPa, Al-Al) 5.1 5.9 6.0 2.3 3.3 Elastic modulus (60°C, MPa) 89 104 130 45 54

[0163] From the results, with the addition of polycarbonate segments in the B component prepolymer, the bulk strength and shear strength of the system are significantly improved, especially the mechanical properties at high temperature 60℃ are significantly improved, but it cannot be ignored that when the content of polycarbonate in the system is too high, the shear strength will not be further improved, and the toughness of the system is significantly reduced, and the elongation at break is significantly reduced; in addition, the effect of adding polycarbonate segments in the form of prepolymer into the formula is significantly better than that of adding them alone in the formula.

[0164] In summary, compared with the prior art, the two-component polyurethane structural adhesive provided by the application has higher bulk strength, higher shear strength and higher elastic modulus at high temperature (50℃-60℃), and the elongation at break of the system can still be maintained at a certain level, maintaining a certain flexibility, meeting the requirements of fatigue resistance, stretch resistance and the like of the battery during automobile driving. The experimental results show that the two-component polyurethane structural adhesive provided by the application has a bulk tensile strength of 12MPa-15MPa, a tensile shear strength of 12MPa-14MPa, an elongation at break of 20%-40%, and an elastic modulus of 600MPa-1000MPa at room temperature 25℃; the bulk strength is 5MPa-7MPa, the tensile shear strength is 5MPa-6MPa, and the elastic modulus is 80MPa-120MPa at high temperature 60℃.

[0165] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high heat-resistant two-component polyurethane structural adhesive for power batteries, comprising component A and component B in a volume ratio of (0.8~1.2):1; wherein component A is prepared from raw materials including the following components: 25 parts by weight of castor oil; 10 to 40 parts by weight of modified castor oil; Chain extender 1 to 10 parts by weight; 30 to 80 parts by weight of aluminum hydroxide flame retardant powder; 1 to 5 parts by weight of thixotropic silica; Adhesion promoter: 0.5 parts by weight to 3 parts by weight; Metal catalyst, 0.05 parts by weight to 0.5 parts by weight; Yellow pigment, 0.1 parts by weight to 1 part by weight; Component B is prepared from raw materials comprising the following components: 30 parts by weight of diisocyanate; 5 to 20 parts by weight of polycarbonate diol; 3 to 15 parts by weight of polyether diol; 30 to 80 parts by weight of aluminum hydroxide flame retardant powder; 1 to 5 parts by weight of thixotropic silica; 0.5 to 3 parts by weight of water-absorbing agent; 0.1 to 1 part by weight of blue pigment; The modified castor oil is selected from one or more of Ito AC-006 modified castor oil, Ito AC-009 modified castor oil, and Vantrus M-365 modified castor oil; the chain extender is selected from 2-ethyl-1,3-hexanediol and / or 2-butyl-2-ethyl-1,3-propanediol; the thixotropic silica is selected from CABOT TS720 and / or Evonik R202; the adhesion promoter is selected from BYK-4510 and / or BYK-4511; and the metal catalyst is Vantrus Coscat-83 organic bismuth catalyst. The diisocyanate is selected from one or more of Wanhua diphenylmethane diisocyanate, liquefied diphenylmethane diisocyanate, and carbodiimide-urea ketimide modified 4,4'-diphenylmethane diisocyanate; the polyether diol is selected from one or more of Wanhua C2020, Dongda DL2000, and Dongda DL1000; the polycarbonate diol is selected from one or more of Asahi Kasei T5652, Asahi Kasei T5651, and Asahi Kasei T5650J; and the water-absorbing agent is Borchers TI water-absorbing agent.

2. A method for preparing a high heat-resistant two-component polyurethane structural adhesive for power batteries as described in claim 1, comprising the following steps: a) Castor oil, modified castor oil, chain extender, aluminum hydroxide flame retardant powder, and silica thixotropic agent are heated to 110℃~130℃ with stirring at 100rpm~300rpm, and dehydrated under vacuum to below -0.09MPa for 1.5h~2.5h. Then, the temperature is lowered to below 50℃, adhesion promoter, metal catalyst, and yellow pigment are added, and the mixture is stirred under vacuum to below -0.09MPa for 50rpm~150rpm for 0.5h~1h to obtain component A. b) Dry the aluminum hydroxide flame retardant powder and silica thixotropic agent in a drying oven at 90℃~110℃ for 20h~30h, and set aside. Stir the diisocyanate, polycarbonate diol and polyether diol at 20℃~30℃ at 50rpm~150rpm and vacuum to -0.1MPa~-0.08MPa for 1h~3h. Then add the pre-dried aluminum hydroxide flame retardant powder and silica thixotropic agent, add the water absorbent and blue pigment, stir at 20℃~30℃ at 150rpm~250rpm and vacuum to -0.1MPa~-0.08MPa for 0.5h~1.5h to obtain component B. c) Mix the above components A and B evenly to obtain a high heat-resistant two-component polyurethane structural adhesive for power batteries. There is no order restriction between steps a) and b).

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