Two-component polyurethane heat-conducting structural adhesive as well as preparation method and application thereof

Abstract

The invention provides a two-component polyurethane heat-conducting structural adhesive as well as a preparation method and application thereof. The two-component polyurethane heat-conducting structural adhesive comprises a component A and a component B in a volume ratio of (0.8-1.2): 1, the component A comprises the following components in parts by weight: dimer acid modified polyol, liquid polybutadiene polyol A, a modified castor oil diluent, liquid polybutadiene A and aluminum hydroxide heat-conducting powder A; and the component B comprises the following components in parts by weight: an isocyanate-terminated prepolymer, isocyanate A, liquid polybutadiene B and aluminum hydroxide heat-conducting powder B. The specific composition of the component A and the component B in the two-component polyurethane heat-conducting structural adhesive is designed, and the two-component polyurethane heat-conducting structural adhesive with higher heat conductivity coefficient, proper shear strength, better mechanical property and better aging property is prepared by matching the components.

Description

Technical Field

[0001] This invention belongs to the technical field of energy storage batteries, specifically relating to a two-component polyurethane thermally conductive structural adhesive, its preparation method and application, and more specifically to a low-strength, easily disassembled two-component polyurethane thermally conductive structural adhesive, its preparation method and application. Background Technology

[0002] Currently in the field of energy storage batteries, the connection between cells, PACKs, and liquid cooling plates mainly relies on thermally conductive adhesives. Previously, the solution widely used by customers was two-component silicone thermally conductive gel. However, due to problems such as high silicone cyclic content and easy silicone oil precipitation, customers have gradually turned to using two-component polyurethane thermally conductive structural adhesives.

[0003] CN120555004A discloses a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive comprises component A and component B. Component A, by mass parts, includes: 40-50 parts of modified polycarbonate polyol, 30-40 parts of modified polyether polyol, 15-25 parts of modified alumina filler, and 1-3 parts of silane coupling agent. The modified polycarbonate polyol is obtained by adding 2-sulfonic acid terephthalic acid and a first catalyst to polycarbonate polyol; the modified polyether polyol is obtained by adding 3-phenylpropionic acid p-nitrobenzene ester and a second catalyst to polyether polyol; the modified alumina filler is obtained by adding alumina filler to potassium perfluorooctyl sulfonate. Component B, by mass parts, includes: 20-30 parts of diphenylmethane diisocyanate, 40-50 parts of modified polycarbonate polyol, 1-3 parts of dehydrating agent, and 20-30 parts of modified alumina filler. The overview solution provides a two-component polyurethane thermally conductive structural adhesive with good flexibility, impact resistance and stability.

[0004] CN119264862A discloses a two-component polyurethane thermally conductive structural adhesive and its preparation method. The structural adhesive comprises component A and component B in a 1:1 volume ratio. Component A includes: 15-25 parts modified polyester polyol, 5-10 parts polyether polyol, 3-8 parts chain extender, 55-67 parts modified thermally conductive filler, 0.2-0.5 parts dispersant one, 0.1-0.3 parts black paste, 0.3-1 parts thixotropic agent, and 1-5 parts dehydrating agent. Component B includes: 30-50 parts blocked polyurethane prepolymer, 45-67 parts modified thermally conductive filler, 0.2-1 parts dispersant one, 0.2-0.5 parts dispersant two, 0.2-0.5 parts defoamer, and 0.2-1 parts dehydrating agent. The polyurethane thermally conductive structural adhesive provided by this technical solution has good mechanical properties, thermal conductivity, and flame retardant properties.

[0005] However, conventional polyurethane thermally conductive structural adhesives have high strength (typically exceeding 8 MPa shear strength for aluminum substrates). For the energy storage industry, structural design does not require excessively high shear strength. More importantly, excessively high shear strength makes rework during the production process very difficult, meaning that once components are glued on, they cannot be disassembled and reassembled by external force.

[0006] Therefore, a demand has gradually emerged in the market for a low-strength, easily disassembled two-component polyurethane thermally conductive structural adhesive, mainly in two aspects: First, the thermal conductivity must meet the customer's design requirements; currently, the market generally requires a thermal conductivity greater than 1.2 W / m·K. Second, the absolute shear strength after curing should not be too high. Customer verification has shown that controlling the shear strength of aluminum substrates within the range of 0.5-1.0 MPa is optimal, ensuring both structural design and safety while facilitating subsequent disassembly and reassembly. How to provide a two-component polyurethane thermally conductive structural adhesive that meets these requirements and possesses good mechanical properties has become a key research focus. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a two-component polyurethane thermally conductive structural adhesive, its preparation method, and its applications. More specifically, it relates to a low-strength, easily disassembled two-component polyurethane thermally conductive structural adhesive, its preparation method, and its applications. The present invention designs the specific compositions of components A and B in the two-component polyurethane thermally conductive structural adhesive, and through the combination of these components, obtains a two-component polyurethane thermally conductive structural adhesive with high thermal conductivity, suitable shear strength, good mechanical properties, and good aging performance.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a two-component polyurethane thermally conductive structural adhesive, comprising component A and component B in a volume ratio of (0.8-1.2):1; component A comprises the following components in parts by weight: 4-20 parts of dimer acid modified polyol, 5-20 parts of liquid polybutadiene polyol A, 3-10 parts of modified castor oil diluent, 3-20 parts of liquid polybutadiene A, and 60-80 parts of aluminum hydroxide thermally conductive powder A; component B comprises the following components in parts by weight: 5-20 parts of isocyanate-based end-polymer, 1-10 parts of isocyanate A, 5-20 parts of liquid polybutadiene B, and 60-80 parts of aluminum hydroxide thermally conductive powder B, wherein the NCO content in the isocyanate-based end-polymer is 8-18 wt%.

[0010] This invention designs the specific composition of component A and component B in a two-component polyurethane thermally conductive structural adhesive, and prepares a two-component polyurethane thermally conductive structural adhesive with high thermal conductivity, suitable shear strength, good mechanical properties and good aging properties through the combination of each component.

[0011] Specifically, this invention reduces the strength of the two-component polyurethane thermally conductive structural adhesive through the synergistic effect of dimer acid-modified polyol and liquid polybutadiene polyol in component A. This allows the shear strength of the two-component polyurethane thermally conductive structural adhesive to be controlled within the range of 0.5-1.0 MPa, ensuring both the structural design and safety of the energy storage battery prepared from this two-component polyurethane thermally conductive structural adhesive, and facilitating subsequent disassembly and reassembly.

[0012] This invention reduces the flexibility of two-component polyurethane thermally conductive structural adhesives by using modified castor oil diluent and liquid polybutadiene plasticizer, while improving the compatibility of the components in the two-component polyurethane thermally conductive structural adhesives and avoiding the migration problems caused by traditional plasticizers.

[0013] In this invention, the use of aluminum hydroxide thermal conductive powder enables the two-component polyurethane thermal conductive structural adhesive to have good thermal conductivity and a high thermal conductivity coefficient.

[0014] In this invention, by controlling the NCO content in the isocyanate-terminated prepolymer within the range of 8-18 wt%, the overall performance of the two-component polyurethane thermally conductive structural adhesive is further improved. If the NCO content in the isocyanate-terminated prepolymer is <8 wt%, the mechanical properties of the two-component polyurethane thermally conductive structural adhesive will decrease. Due to the excessively low NCO content, the molecular weight of the polymer is too large, resulting in better overall flexibility but too low absolute strength, leading to shear strength that cannot meet customer requirements and posing a safety hazard after bonding. If the NCO content in the isocyanate-terminated prepolymer is >18 wt%, the mechanical properties of the two-component polyurethane thermally conductive structural adhesive will be too high. Due to the excessively high NCO content, the molecular weight of the polymer is too low, resulting in insufficient overall flexibility and excessively high absolute strength, leading to shear strength exceeding the target requirements. Although the adhesive is strong, subsequent disassembly is not possible.

[0015] In this invention, the volume ratio of component A to component B in the two-component polyurethane thermally conductive structural adhesive can be 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, 1.05:1, 1.1:1, 1.15:1, or 1.2:1, etc.

[0016] In this invention, the weight percentage of the dimer acid-modified polyol in component A can be 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0017] The weight percentage of liquid polybutadiene polyol A in component A can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0018] The weight percentage of modified castor oil diluent A in component A can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, or 10 parts, etc.

[0019] The weight percentage of liquid polybutadiene A in component A can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0020] The weight percentage of aluminum hydroxide thermal conductive powder A in component A can be 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 70, or 80 parts, etc.

[0021] The weight percentage of isocyanate-terminated prepolymer in component B can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0022] The weight percentage of isocyanate A in component B can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts, etc.

[0023] The weight percentage of liquid polybutadiene B in component B can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0024] The weight percentage of aluminum hydroxide thermal conductive powder B in component B can be 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 70, or 80 parts, etc.

[0025] The NCO content in the isocyanate-terminated prepolymer is 8-18 wt%, for example, it can be 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, or 18 wt%, etc.

[0026] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0027] Preferably, the number average molecular weight of the dimer acid modified polyol is 1500-2500 (for example, it can be 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400 or 2500, etc.), preferably 2000.

[0028] Preferably, the functionality of the dimer acid modified polyol is 1.5-2.5, for example, it can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5, and more preferably 2.0.

[0029] In this invention, the dimer acid modified polyols include, but are not limited to, any one or a combination of at least two of the following: Cargill Priplast1838, Oleon RADIA 7287, Zhejiang Huangma HMN-1142T, and Shanghai Xunjie XJ-56.

[0030] Preferably, the number average molecular weight of the liquid polybutadiene polyol A is 2500-3500, for example, it can be 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400 or 3500.

[0031] Preferably, the functionality of the liquid polybutadiene polyol A is 2.0-2.5, for example, it can be 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5.

[0032] In this invention, the liquid polybutadiene polyol A includes, but is not limited to, any one or a combination of at least two of the following: Cray Valley Polybd R45V, Evonik Polyvest HT, and Tianyuan Aerospace Materials HTPB-2500;

[0033] Preferably, the number average molecular weight of the modified castor oil diluent is 500-1000, for example, it can be 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 or 1000.

[0034] In this invention, the modified castor oil diluent includes, but is not limited to, any one or a combination of at least two of Itoh Oil URIC Y-403, Itoh Oil URIC Y-406, Itoh Oil URIC H-4128, and Vertellus Polycin D-290.

[0035] Preferably, the number average molecular weights of liquid polybutadiene A and liquid polybutadiene B are each independently 2000-5000, for example, 2000, 2200, 2500, 2700, 3000, 3300, 3600, 3800, 4000, 4200, 4500, 4600, 4900 or 5000, etc.

[0036] In this invention, the liquid polybutadiene A and liquid polybutadiene B are exemplary, including but not limited to: Evonik Polyvest 110 and / or Evonik Polyvest 130.

[0037] Preferably, the D95 particle size of the aluminum hydroxide thermal conductive powder A and the aluminum hydroxide thermal conductive powder B is independently ≤100 μm, for example, it can be 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm or 100 μm, etc.

[0038] Preferably, the aluminum hydroxide thermal conductive powder A and the aluminum hydroxide thermal conductive powder B are each independently spherical or near-spherical.

[0039] This invention enables the preparation of a high-performance two-component polyurethane thermally conductive structural adhesive by selecting D95 particle size and spherical or near-spherical aluminum hydroxide thermally conductive powder. The use of spherical or near-spherical aluminum hydroxide thermally conductive powder avoids the significant wear caused to the adhesive application equipment by irregularly shaped aluminum hydroxide thermally conductive powder.

[0040] Preferably, the aluminum hydroxide thermal conductive powder A includes, but is not limited to, any one or a combination of at least two of Guangdong Yuxing DF-12UA-5, Leyuan Chemical EL-U130-A, and Leyuan Chemical EL-U200-A; the aluminum hydroxide thermal conductive powder B includes, but is not limited to, any one or a combination of at least two of Guangdong Yuxing DF-12UB-8, Leyuan Chemical EL-U130-B, and Leyuan Chemical EL-U200-B.

[0041] Preferably, the isocyanate A includes any one of self-carbodiimide-modified MDI, diphenylmethane diisocyanate, and HDI trimer.

[0042] In this invention, isocyanate A includes, but is not limited to, any one or a combination of at least two of the following: WANNATE CDMDI-100L, WANNATE MDI-50, Covestro Desmodur N3300, and Covestro Desmodur N100.

[0043] Preferably, the NCO content in the isocyanate-terminated prepolymer is 10-14 wt%, for example, it can be 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, or 14 wt%, etc.

[0044] In this invention, by controlling the NCO content in the isocyanate-terminated prepolymer to be in the range of 10-14 wt%, the overall performance of the two-component polyurethane thermally conductive structural adhesive can be further improved.

[0045] Preferably, the raw materials for preparing the isocyanate-terminated prepolymer include the following components in parts by mass: polyol and isocyanate B; wherein the polyol includes polyether polyol and / or liquid polybutadiene polyol B.

[0046] Preferably, the polyol is selected from a combination including polyether polyol and liquid polybutadiene polyol B.

[0047] Preferably, the polyol is selected from polyether polyol and liquid polybutadiene polyol B, and the mass ratio of the polyether polyol to the liquid polybutadiene polyol B is (0.8-1.2):1, for example, it can be 0.8:1, 0.85:1, 0.9:1, 0.95:1, 1:1, 1.15:1 or 1.2:1, etc.

[0048] The present invention preferably includes a combination of polyether polyol and liquid polybutadiene polyol B as the polyol, and further controls the mass ratio of polyether polyol and liquid polybutadiene polyol B in the range of (0.8-1.2):1, which further improves the overall performance of the two-component polyurethane thermally conductive structural adhesive.

[0049] Preferably, the number average molecular weight of the polyether polyol is 1500-2500, for example, it can be 1500, 1600, 1700, 1800, 1900, 2000, 2200, 2300, 2400 or 2500.

[0050] Preferably, the functionality of the polyether polyol is 2.

[0051] In this invention, the polyether polyols include, but are not limited to, Wanhua WANOL C2020 and Lanxing Dongda DL-2000D.

[0052] Preferably, the number average molecular weight of the liquid polybutadiene polyol B is 2500-3500, for example, it can be 2500, 2600, 2700, 2800, 1900, 3000, 3100, 3200, 3300, 3400 or 3500.

[0053] Preferably, the functionality of the liquid polybutadiene polyol B is 2.0-2.5, for example, it can be 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5.

[0054] In this invention, the liquid polybutadiene polyol B includes, but is not limited to, any one or a combination of at least two of the following: Cray Valley Polybd R45V, Evonik Polyvest HT, and Tianyuan Aerospace Materials HTPB-2500.

[0055] Preferably, the isocyanate B is selected from any one or a combination of at least two of carbodiimide-modified MDI, diphenylmethane diisocyanate, and HDI trimer.

[0056] In this invention, the isocyanate B includes, but is not limited to, any one or a combination of at least two of the following: WANNATE CDMDI-100L, WANNATE MDI-50, Covestro Desmodur N3300, and Covestro Desmodur N100.

[0057] Preferably, the isocyanate-terminated prepolymer is prepared by the following method, which includes the following steps: mixing a polyol and isocyanate B, reacting them, and obtaining the isocyanate-terminated prepolymer.

[0058] Preferably, the mixing process further includes a pretreatment step, wherein the pretreatment method includes dehydrating the polyol.

[0059] Preferably, the vacuum degree of the dehydration treatment is ≤-0.09 MPa, the temperature is 110-130℃ (e.g., 110℃, 112℃, 114℃, 116℃, 118℃, 120℃, 122℃, 124℃, 126℃, 128℃ or 130℃, etc.), and the time is 1.5-2.5 h (e.g., 1.5 h, 2 h or 2.5 h, etc.).

[0060] Preferably, after the dehydration treatment, the water content of the polyol is <200 ppm, for example, it can be 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm or 190 ppm, etc.

[0061] Preferably, the reaction temperature is 60-80℃, for example, it can be 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃, or 80℃, etc.

[0062] Preferably, the vacuum degree of the reaction is ≤ -0.09 MPa.

[0063] Preferably, the reaction is carried out under stirring at a speed of 80-120 rpm, such as 80 rpm, 85 rpm, 90 rpm, 95 rpm, 100 rpm, 105 rpm, 110 rpm, 115 rpm or 120 rpm.

[0064] In this invention, the isocyanate-terminated prepolymer is prepared by the following method, which specifically includes the following steps:

[0065] Polyols were dehydrated for 1.5-2.5 h under vacuum conditions ≤ -0.09 MPa and 110-130℃ to reduce their water content to <200 ppm.

[0066] The dehydrated polyol and isocyanate B were mixed and reacted at 60-80℃, vacuum degree ≤-0.09 MPa and rotation speed 80-120 rpm to obtain an isocyanate-terminated prepolymer with an NCO content of 8-18wt%.

[0067] Preferably, components A and B each independently include any one or a combination of at least two of the following: silica, molecular sieve, color paste, anti-aging agent, and water-absorbing agent.

[0068] Preferably, the color paste A comprises a yellow color paste.

[0069] Preferably, the color paste B comprises a blue color paste.

[0070] In this invention, there are no special restrictions on the specific selection of silica, molecular sieve, yellow pigment paste, blue pigment paste, anti-aging agent, and water absorbent; all of the above-mentioned additives commonly used in the art are applicable. The silica, exemplarily including but not limited to, is any one or a combination of two of CABOT CAB-O-SIL TS-720 and Evonik AEROSIL R202; the molecular sieve, exemplarily including but not limited to, is any one or a combination of two of Guangji GJH-03A and Grace Sylosiv A300; the yellow pigment, exemplarily including but not limited to, is any one or a combination of two of Baomeishi 085-1I4215 and Jiasheng PUC4009; the blue pigment, exemplarily including but not limited to, is any one or a combination of two of Baomeishi 085-5M4214 and Jiasheng PUC4010; the anti-aging agent, exemplarily including but not limited to, is any one or a combination of two of Taiwan double bond Chinox TP-10H and BASF Irganox B215; the water absorbent, exemplarily including but not limited to, is any one or a combination of two of Borchers TI and LANXESS Trixene ASF.

[0071] Preferably, the weight percentages of silica in component A and component B are each 0.5-5 parts, for example, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts, etc.

[0072] Preferably, the weight fractions of molecular sieves in component A and component B are each 1-5 parts, for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts, etc.

[0073] Preferably, the weight percentage of the pigment in component A and component B is 0.1-1 parts, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 part, etc.

[0074] Preferably, the weight percentage of the anti-aging agent in component A and component B is 0.1-1 parts each, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 part, etc.

[0075] Preferably, the weight percentage of the water-absorbing agent in component A and component B is 0.1-1 parts each, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 part, etc.

[0076] Preferably, component A further includes silica, molecular sieve, and yellow pigment.

[0077] Preferably, component B further includes silica, molecular sieve, blue pigment, anti-aging agent, and water-absorbing agent.

[0078] In a second aspect, the present invention provides a method for preparing a two-component polyurethane thermally conductive structural adhesive as described in the first aspect, the preparation method comprising the following steps:

[0079] Preparation of component A: Mix and degas the components in component A to obtain component A;

[0080] Preparation of component B: Mix the components in component B and degas to obtain component B;

[0081] Preparation of two-component polyurethane thermally conductive structural adhesive: Component A and component B are mixed at a volume ratio of (0.8-1.2):1 to obtain the two-component polyurethane thermally conductive structural adhesive.

[0082] Preferably, the mixing methods for preparing component A and preparing component B each independently include stirring, wherein the stirring speed is 450-550 rpm, for example, 450 rpm, 460 rpm, 470 rpm, 480 rpm, 490 rpm, 500 rpm, 510 rpm, 520 rpm, 530 rpm, 540 rpm, or 550 rpm.

[0083] Preferably, the degassing time for preparing component A and component B is independently 1-3 h, for example, it can be 1 h, 1.5 h, 2 h, 2.5 h or 3 h, etc.

[0084] Preferably, the degassing is performed under a vacuum of ≤-0.09 MPa.

[0085] Preferably, the water content of component A is <150 ppm, for example, it can be 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm or 140 ppm, etc.

[0086] It should be noted that the preparation of component A includes a pretreatment step before mixing. The pretreatment method includes dehydrating the dimer acid-modified polyol, liquid polybutadiene polyol A, modified castor oil diluent A, and liquid polybutadiene A respectively; and drying the aluminum hydroxide thermal conductive powder A and optionally, precipitated silica. The preparation of component B also includes a pretreatment step before mixing. The pretreatment method includes dehydrating the liquid polybutadiene B; and drying the aluminum hydroxide thermal conductive powder B and optionally, precipitated silica.

[0087] This invention does not impose any special limitations on the process parameters of the above dehydration treatment. For example, the vacuum degree of the dehydration treatment is ≤-0.09 MPa, the temperature is 110-130℃, and the time is 1.5-2.5 h. After the dehydration treatment, the water content of each of the above components is independently <200 ppm.

[0088] This invention does not impose any special limitations on the process parameters of the above-mentioned drying treatment. For example, the drying temperature is 90-110℃ and the time is 42-54 h. After drying, the water content of the component is <200 ppm.

[0089] Thirdly, the present invention provides a two-component polyurethane thermally conductive structural adhesive as described in the first aspect, wherein the two-component polyurethane thermally conductive structural adhesive is used to prepare an energy storage battery.

[0090] Compared with the prior art, the present invention has the following beneficial effects:

[0091] (1) This invention designs the specific composition of component A and component B in the two-component polyurethane thermally conductive structural adhesive, and prepares a two-component polyurethane thermally conductive structural adhesive with high thermal conductivity, suitable shear strength, good mechanical properties and good aging properties by combining each component.

[0092] (2) The present invention further improves the overall performance of two-component polyurethane thermally conductive structural adhesive by using a specific isocyanate-terminated prepolymer. Detailed Implementation

[0093] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0094] Example 1

[0095] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1:1.

[0096] Component A comprises the following components in parts by weight: 8 parts of dimer acid modified polyol (Cargill Priplast 1838), 8 parts of liquid polybutadiene polyol (Cray Valley Poly bd R45V), 8 parts of modified castor oil diluent (Itoh Oil URIC Y-403), 6.5 parts of liquid polybutadiene (Evonik Polyvest 130), 65 parts of aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UA-5), 1 part of silica (CABOT CAB-O-SIL TS-720), 3 parts of molecular sieve (Guangji GJH-03A), and 0.5 parts of yellow pigment (Baomeishi 085-1I4215).

[0097] Component B comprises the following components in parts by weight: 10 parts isocyanate-terminated prepolymer, 5 parts isocyanate (Covestro Desmodur N3300), 14 parts liquid polybutadiene (Evonik Polyvest 130), 65 parts aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UB-8), 1 part silica (CABOT CAB-O-SIL TS-720), 3 parts molecular sieve (Guangji GJH-03A), 1 part anti-aging agent (Taiwan Chinox TP-10H), 0.5 parts water-absorbing agent (Borchers TI), and 0.5 parts blue pigment (Baomeishi 085-5M4214).

[0098] The preparation method of the isocyanate-terminated prepolymer is as follows: polyether polyol (WANOL C2020) and liquid polybutadiene polyol (Cray Valley Poly bd R45V) are dehydrated for 2 h at -0.09 MPa and 120℃ to make their water content <200 ppm;

[0099] 150 parts by weight of dehydrated polyether polyol (WANOL C2020), 150 parts by weight of liquid polybutadiene polyol (Cray Valley Poly bd R45V), and 200 parts by weight of isocyanate (WANNATE CDMDI-100L) were mixed and reacted at 70°C, -0.09 MPa, and 100 rpm until the NCO content reached 10.50 wt%, at which point the reaction was stopped to obtain an isocyanate-terminated prepolymer.

[0100] The preparation method of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as follows:

[0101] Preparation of Component A: Dimer acid-modified polyol, liquid polybutadiene polyol, modified castor oil diluent, and liquid polybutadiene were dehydrated at -0.09 MPa and 120℃ for 2 h to reduce their water content to <200 ppm; aluminum hydroxide thermal conductive powder and silica were dried at 100℃ for 48 h to reduce their water content to <200 ppm; the above dehydrated components, dried components, and other components of Component A were stirred and mixed evenly at 500 rpm, and then degassed at -0.09 MPa for 2 h to obtain Component A with a water content of <150 ppm;

[0102] Preparation of Component B: Liquid polybutadiene polyol was dehydrated at -0.09 MPa and 120℃ for 2 h to reduce its water content to <200 ppm; aluminum hydroxide thermal conductive powder and silica were dried at 100℃ for 48 h to reduce their water content to <200 ppm; the dehydrated components, dried components, and other components of Component B were stirred and mixed evenly at 500 rpm, and then degassed at -0.09 MPa for 2 h to obtain Component B;

[0103] Preparation of two-component polyurethane thermally conductive structural adhesive: Component A and component B are mixed evenly at a volume ratio of 1:1 to obtain the two-component polyurethane thermally conductive structural adhesive.

[0104] Example 2

[0105] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1:1.

[0106] Component A comprises the following components in parts by weight: 10 parts of dimer acid modified polyol (HMN-1142T), 8.5 parts of liquid polybutadiene polyol (Evonik Polyvest HT), 6 parts of modified castor oil diluent (Itoh Oil URIC Y-406), 6 parts of liquid polybutadiene (Evonik Polyvest 130), 65 parts of aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U130-A), 1 part of silica (CABOT CAB-O-SIL TS-720), 3 parts of molecular sieve (Guangji GJH-03A), and 0.5 parts of yellow pigment (Baomeishi 085-1I4215).

[0107] Component B comprises the following components in parts by weight: 15 parts isocyanate-terminated prepolymer, 5 parts isocyanate (Covestro Desmodur N3300), 9 parts liquid polybutadiene (Evonik Polyvest 130), 65 parts aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U130-B), 1 part silica (CABOT CAB-O-SIL TS-720), 3 parts molecular sieve (Guangji GJH-03A), 1 part anti-aging agent (Taiwan Chinox TP-10H), 0.5 parts water-absorbing agent (Borchers TI), and 0.5 parts blue pigment (Baomeishi 085-5M4214).

[0108] The preparation method of the isocyanate-terminated prepolymer is as follows: the polyether polyol (WANOL C2020) is dehydrated for 2 h at -0.09 MPa and 120℃ to make its water content <200 ppm;

[0109] 300 parts by weight of dehydrated polyether polyol (WANOL C2020) and 200 parts by weight of isocyanate (WANNATE CDMDI-100L) were mixed and reacted at 70°C, -0.09 MPa and 100 rpm until the NCO content was 9.50 wt%, and the reaction was stopped to obtain isocyanate-terminated prepolymer.

[0110] The preparation of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as described in Example 1.

[0111] Example 3

[0112] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1:1.

[0113] Component A comprises the following components in parts by weight: 6 parts of dimer acid modified polyol (Oleon RADIA 7287), 6 parts of liquid polybutadiene polyol (Evonik Polyvest HT), 4 parts of modified castor oil diluent (Itoh Oil URICY-406), 5.5 parts of liquid polybutadiene (Evonik Polyvest 110), 75 parts of aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U200-A), 1 part of silica (Evonik AEROSIL R202), 2 parts of molecular sieve (Grace Sylosiv A300), and 0.5 parts of yellow pigment (Jiasheng PUC4009).

[0114] Component B comprises the following components in parts by weight: 8 parts isocyanate-terminated prepolymer, 4 parts isocyanate (Covestro Desmodur N100), 8 parts liquid polybutadiene (Evonik Polyvest 110), 75 parts aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U200-B), 1 part silica (Evonik AEROSIL R202), 2 parts molecular sieve (Grace Sylosiv A300), 1 part anti-aging agent (BASF Irganox B215), 0.5 parts water-absorbing agent (LANXESS Trixene ASF), and 0.5 parts blue pigment (Jiasheng PUC4010).

[0115] The isocyanate-terminated prepolymer is prepared as follows: liquid polybutadiene polyol (Evonik Polyvest HT) is dehydrated for 2 h at -0.09 MPa and 120℃ to reduce its water content to <200 ppm.

[0116] 100 parts by weight of dehydrated liquid polybutadiene polyol (Evonik Polyvest HT) and 120 parts by weight of isocyanate (WANNATE MDI-50) were mixed and reacted at 70°C, -0.09 MPa and 100 rpm until the NCO content reached 13.00 wt%, at which point the reaction was stopped to obtain an isocyanate-terminated prepolymer.

[0117] The preparation of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as described in Example 1.

[0118] Example 4

[0119] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1:1.

[0120] Component A comprises the following components in parts by weight: 4 parts of dimer acid modified polyol (Shanghai Xunjie XJ-56), 5 parts of liquid polybutadiene polyol (Tianyuan Aviation Materials HTPB-2500), 3 parts of modified castor oil diluent (Vertellus Polycin D-290), 3.5 parts of liquid polybutadiene (Evonik Polyvest 110), 80 parts of aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U200-A), 1 part of silica (Evonik AEROSIL R202), 3 parts of molecular sieve (Grace Sylosiv A300), and 0.5 parts of yellow pigment (Jiasheng PUC4009).

[0121] Component B comprises the following components in parts by weight: 6 parts isocyanate-terminated prepolymer, 4 parts isocyanate (Covestro Desmodur N100), 7 parts liquid polybutadiene (Evonik Polyvest 110), 78 parts aluminum hydroxide thermal conductive powder (Leyuan Chemical EL-U200-B), 1 part silica (Evonik AEROSIL R202), 2 parts molecular sieve (Grace Sylosiv A300), 1 part anti-aging agent (BASF Irganox B215), 0.5 parts water-absorbing agent (LANXESS Trixene ASF), and 0.5 parts blue pigment (Jiasheng PUC4010).

[0122] The preparation method of the isocyanate-terminated prepolymer is as follows: 150 parts of polyether polyol (Lanxing Dongda DL-2000D) and 150 parts of liquid polybutadiene polyol (Tianyuan Aviation Materials HTPB-2500) were dehydrated for 2 h at -0.09 MPa and 120℃ to make their water content <200 ppm;

[0123] 100 parts by weight of dehydrated polyether polyol (Lanxing Dongda DL-2000D), 100 parts by weight of liquid polybutadiene polyol (Tianyuan Aviation Materials HTPB-2500), and 200 parts by weight of isocyanate (Wanhua WANNATE MDI-50) were mixed and reacted at 70℃, -0.09 MPa, and 100 rpm until the NCO content reached 11.50 wt%, at which point the reaction was stopped to obtain an isocyanate-terminated prepolymer.

[0124] The preparation of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as described in Example 1.

[0125] Example 5

[0126] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1:1.

[0127] Component A comprises the following components in parts by weight: 20 parts of dimer acid modified polyol (Cargill Priplast 1838), 12 parts of liquid polybutadiene polyol (Cray Valley Poly bd R45V), 5 parts of modified castor oil diluent (Itoh Oil URIC Y-403), 20 parts of liquid polybutadiene (Evonik Polyvest 130), 60 parts of aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UA-5), 4 parts of silica (CABOT CAB-O-SIL TS-720), 1 part of molecular sieve (Guangji GJH-03A), and 0.5 parts of yellow pigment (Baomeishi 085-1I4215).

[0128] Component B comprises the following components in parts by weight: 20 parts isocyanate-terminated prepolymer, 18 parts isocyanate (Covestro Desmodur N3300), 20 parts liquid polybutadiene (Evonik Polyvest 130), 60 parts aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UB-8), 3 parts silica (CABOT CAB-O-SIL TS-720), 1 part molecular sieve (Guangji GJH-03A), 0.5 parts anti-aging agent (Taiwan Chinox TP-10H), 0.5 parts water-absorbing agent (Borchers TI), and 0.5 parts blue pigment (Baomeishi 085-5M4214); wherein the preparation method of the isocyanate-terminated prepolymer is the same as in Example 1.

[0129] The preparation of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as described in Example 1.

[0130] Example 6

[0131] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The two-component polyurethane thermally conductive structural adhesive includes component A and component B with a volume ratio of 1.1:1.

[0132] Component A comprises the following components in parts by weight: 14 parts of dimer acid modified polyol (Cargill Priplast 1838), 20 parts of liquid polybutadiene polyol (Cray Valley Poly bd R45V), 9 parts of modified castor oil diluent (Itoh Oil URIC Y-403), 13 parts of liquid polybutadiene (Evonik Polyvest 130), 78 parts of aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UA-5), 3 parts of silica (CABOT CAB-O-SIL TS-720), 4 parts of molecular sieve (Guangji GJH-03A), and 0.5 parts of yellow pigment (Baomeishi 085-1I4215).

[0133] Component B comprises the following components in parts by weight: 12 parts isocyanate-terminated prepolymer, 3 parts isocyanate (Covestro Desmodur N3300), 12 parts liquid polybutadiene (Evonik Polyvest 130), 70 parts aluminum hydroxide thermal conductive powder (Guangdong Yuxing DF-12UB-8), 2 parts silica (CABOT CAB-O-SIL TS-720), 2 parts molecular sieve (Guangji GJH-03A), 0.5 parts anti-aging agent (Taiwan Chinox TP-10H), 0.5 parts water-absorbing agent (Borchers TI), and 0.5 parts blue pigment (Baomeishi 085-5M4214); wherein the preparation method of the isocyanate-terminated prepolymer is the same as in Example 3.

[0134] The preparation of the above-mentioned two-component polyurethane thermally conductive structural adhesive is as described in Example 1.

[0135] Example 7

[0136] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the weight of polyether polyol (WANOLC2020) and liquid polybutadiene polyol (Cray Valley Poly bd R45V) in the raw materials for preparing the isocyanate-terminated prepolymer in component B is adjusted to 100 parts by weight and 200 parts by weight. Other conditions are the same as in Example 1.

[0137] Example 8

[0138] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the weight of polyether polyol (WANOLC2020) and liquid polybutadiene polyol (Cray Valley Poly bd R45V) in the raw materials for preparing the isocyanate-terminated prepolymer in component B is adjusted to 200 parts by weight and 100 parts by weight. Other conditions are the same as in Example 1.

[0139] Example 9

[0140] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the isocyanate-terminated prepolymer used in component B is not liquid polybutadiene polyol (CrayValley Poly bd R45V), and the weight of polyether polyol (WANOL C2020) is adjusted to 300 parts by weight. Other conditions are the same as in Example 1.

[0141] Example 10

[0142] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the isocyanate-terminated prepolymer used in component B is not polyether polyol (WANOLC2020), and the weight of liquid polybutadiene polyol (Cray Valley Poly bd R45V) is adjusted to 300 parts by weight. Other conditions are the same as in Example 1.

[0143] Example 11

[0144] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that when preparing the isocyanate-terminated prepolymer, the reaction is stopped after the NCO content reaches 8.2 wt%. Other conditions are the same as in Example 1.

[0145] Example 12

[0146] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that when preparing the isocyanate-terminated prepolymer, the reaction is stopped after the NCO content reaches 12.6 wt%. Other conditions are the same as in Example 1.

[0147] Example 13

[0148] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that when preparing the isocyanate-terminated prepolymer, the reaction is stopped after the NCO content reaches 13.9 wt%. Other conditions are the same as in Example 1.

[0149] Example 14

[0150] This embodiment provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that when preparing the isocyanate-terminated prepolymer, the reaction is stopped after the NCO content reaches 17.7 wt%. Other conditions are the same as in Example 1.

[0151] Comparative Example 1

[0152] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that when preparing the isocyanate-terminated prepolymer, the reaction is stopped after the NCO content reaches 7.1 wt%. Other conditions are the same as in Example 1.

[0153] Comparative Example 2

[0154] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the reaction is stopped after the NCO content reaches 19.4 wt% when preparing the isocyanate-terminated prepolymer. Other conditions are the same as in Example 1.

[0155] Comparative Example 3

[0156] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that liquid polybutadiene polyol (Cray Valley Poly bd R45V) was not used in component A, and the weight of dimer acid modified polyol (Cargill Priplast 1838) was adjusted to 16 parts. Other conditions are the same as in Example 1.

[0157] Comparative Example 4

[0158] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that dimer acid modified polyol (Cargill Priplast 1838) was not used in component A, and the weight of liquid polybutadiene polyol (Cray Valley Poly bd R45V) was adjusted to 16 parts. Other conditions are the same as in Example 1.

[0159] Comparative Example 5

[0160] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that liquid polybutadiene (Evonik Polyvest 130) was not used in component A, and the weight of modified castor oil diluent (Itoh Oil URIC Y-403) was adjusted to 14.5 parts. Other conditions are the same as in Example 1.

[0161] Comparative Example 6

[0162] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that modified castor oil diluent (Itoh Oil URIC Y-403) was not used in component A, and the weight of liquid polybutadiene (Evonik Polyvest 130) was adjusted to 14.5 parts. Other conditions are the same as in Example 1.

[0163] Comparative Example 7

[0164] This comparative example provides a two-component polyurethane thermally conductive structural adhesive and its preparation method. The only difference from Example 1 is that the liquid polybutadiene (Evonik Polyvest 130) in component A is replaced with an equal weight amount of diisononyl phthalate; the liquid polybutadiene (Evonik Polyvest 130) in component B is replaced with an equal weight amount of diisononyl phthalate; other conditions are the same as in Example 1.

[0165] The performance of the two-component polyurethane thermally conductive structural adhesives provided in the above embodiments and comparative examples was tested, and the specific test methods are as follows:

[0166] (1) Thermal conductivity: ASTM D5470, Standard Test Method for Thermal Conductivity of Thermally Conductive Insulating Materials;

[0167] (2) Shear strength: GB / T 7124-2008, Determination of tensile shear strength of adhesives (rigid material to rigid material).

[0168] (3) Tensile strength of the body: GB / T 528-2009, Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber;

[0169] (4) Elongation at break: GB / T 528-2009, Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber;

[0170] (5) Breakdown voltage: ASTM D149, Test method for dielectric breakdown voltage and dielectric strength of solid electrical insulating materials at industrial power frequencies;

[0171] (6) Volume resistivity: ASTM D257, standard test method for DC resistance or conductance of insulating materials;

[0172] (7) High temperature and high humidity aging (85°C / 85%RH): GB / T 2423.50-2012, Environmental testing of electrical and electronic products - Part 2: Test methods. Constant humidity and heat are mainly used for accelerated testing of components.

[0173] (8) Thermal shock aging: GB / T 2423.102-2008, Environmental testing of electrical and electronic products - Part 2: Test methods: Temperature (low temperature, high temperature) / Low pressure / Vibration (sine) combined.

[0174] The above performance tests are detailed in Table 1-3 below:

[0175] Table 1

[0176]

[0177] Table 2

[0178]

[0179] For example, the calculation method for the decay rate of thermal conductivity after 1000 h of high temperature and high humidity aging treatment is: (thermal conductivity before 1000 h of high temperature and high humidity aging treatment - thermal conductivity after 1000 h of high temperature and high humidity aging treatment) ÷ thermal conductivity before 1000 h of high temperature and high humidity aging treatment × 100%.

[0180] Table 3

[0181]

[0182] For example, the calculation method for the decay rate of thermal conductivity after thermal shock aging treatment is: (thermal conductivity before thermal shock aging treatment - thermal conductivity after thermal shock aging treatment) ÷ thermal conductivity before thermal shock aging treatment × 100%.

[0183] As described above, this invention designs the specific compositions of components A and B in a two-component polyurethane thermally conductive structural adhesive, and prepares a two-component polyurethane thermally conductive structural adhesive with high thermal conductivity, suitable shear strength, good mechanical properties, and good aging performance through the combination of each component. Its thermal conductivity is 1.20-1.50 W / (m·K), shear strength (Al3003) is 0.5-1.5 MPa, bulk tensile strength is 0.5-1.5 MPa, elongation at break is ≥40%, specifically 40-110%, breakdown voltage is ≥25 kV / mm, specifically 25-35 kV / mm, and volume resistivity is ≥1×10⁻⁶. 14 Ω·cm, specifically 2×10 14 Ω·cm - 6×10 15 Ω·cm; After high temperature and high humidity aging treatment for 1000 h, the thermal conductivity decay rate is 1.76-17.13%, the shear strength (Al3003) decay rate is 5.21-19.97%, the bulk tensile strength decay rate is 7.98-19.05%, the elongation at break decay rate is 8.52-19.09%, the breakdown voltage decay rate is 5.08-19.65%, and the volume resistivity decay rate is 5.77-18.39%; After thermal shock aging treatment, the thermal conductivity decay rate is 6.1-15.9%, the shear strength (Al3003) decay rate is 2.5-18.8%, the bulk tensile strength decay rate is 2.1-17.3%, the elongation at break decay rate is 6.6-16.2%, the breakdown voltage decay rate is 6.1-19.4%, and the volume resistivity decay rate is 5.6-19.9%.

[0184] As can be seen from Examples 1 and 7-14, and Comparative Examples 1-2, the present invention improves the overall performance of the two-component polyurethane thermally conductive structural adhesive by using a specific isocyanate-based end-capping prepolymer, designing the raw materials for preparing the isocyanate-based end-capping prepolymer, further using a combination of polyether polyol and polybutadiene polyol as the polyester polyol, and simultaneously controlling the NCO content in the isocyanate-based end-capping prepolymer within the range of 8-18 wt%.

[0185] Furthermore, by controlling the mass ratio of polyether polyol to polybutadiene polyol in the raw materials for preparing the isocyanate-based end-capped prepolymer within the range of (0.8-1.2):1, and controlling the NCO content in the isocyanate-based end-capped prepolymer within the range of 10-14 wt%, the present invention can further optimize and improve the comprehensive performance of the two-component polyurethane thermally conductive structural adhesive.

[0186] As can be seen from Examples 1-14 and Comparative Examples 3-7, the present invention designs the specific composition of component A and component B in the two-component polyurethane thermally conductive structural adhesive, and prepares a two-component polyurethane thermally conductive structural adhesive with high thermal conductivity, suitable shear strength, good mechanical properties and good aging properties through the combination of each component.

[0187] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A two-component polyurethane thermally conductive structural adhesive, characterized in that, The two-component polyurethane thermally conductive structural adhesive comprises component A and component B in a volume ratio of (0.8-1.2):

1. Component A comprises the following components in parts by weight: 4-20 parts of dimer acid-modified polyol; Liquid polybutadiene polyol A, 5-20 parts; 3-10 parts of modified castor oil diluent; Liquid polybutadiene A 3-20 parts; Aluminum hydroxide thermal conductive powder A: 60-80 parts; Component B comprises the following components in parts by weight: 5-20 parts of isocyanate-terminated prepolymer; Isocyanate A 1-10 parts; Liquid polybutadiene B, 5-20 parts; Aluminum hydroxide thermal conductive powder B: 60-80 parts; The NCO content in the isocyanate-terminated prepolymer is 8-18 wt%.

2. The two-component polyurethane thermally conductive structural adhesive according to claim 1, characterized in that, The number average molecular weight of the dimer acid-modified polyol is 1500-2500, preferably 2000; Preferably, the functionality of the dimer acid-modified polyol is 1.5-2.5, more preferably 2.0; Preferably, the number-average molecular weight of the liquid polybutadiene polyol A is 2500-3500; Preferably, the functionality of the liquid polybutadiene polyol A is 2.0-2.

5.

3. The two-component polyurethane thermally conductive structural adhesive according to claim 1 or 2, characterized in that, The number average molecular weight of the modified castor oil diluent is 500-1000; Preferably, the number-average molecular weights of liquid polybutadiene A and liquid polybutadiene B are each independently 2000-5000.

4. The two-component polyurethane thermally conductive structural adhesive according to any one of claims 1-3, characterized in that, The D95 particle size of aluminum hydroxide thermal conductive powder A and aluminum hydroxide thermal conductive powder B is independently ≤100 μm. Preferably, the isocyanate A comprises any one or a combination of at least two of carbodiimide-modified MDI, diphenylmethane diisocyanate, and HDI trimer.

5. The two-component polyurethane thermally conductive structural adhesive according to any one of claims 1-4, characterized in that, The NCO content in the isocyanate-terminated prepolymer is 10-14 wt%. Preferably, the raw materials for preparing the isocyanate-terminated prepolymer include the following components in parts by weight: polyol and isocyanate B; The polyols include polyether polyols and / or liquid polybutadiene polyol B; Preferably, the polyol is selected from a combination including polyether polyol and liquid polybutadiene polyol B; Preferably, the polyol is selected from polyether polyol and liquid polybutadiene polyol B, and the mass ratio of the polyether polyol to the liquid polybutadiene polyol B is (0.8-1.2):1; Preferably, the number-average molecular weight of the polyether polyol is 1500-2500; Preferably, the functionality of the polyether polyol is 2; Preferably, the number-average molecular weight of the liquid polybutadiene polyol B is 2500-3500; Preferably, the functionality of the liquid polybutadiene polyol B is 2.0-2.5; Preferably, the isocyanate B is selected from any one or a combination of at least two of carbodiimide-modified MDI, diphenylmethane diisocyanate, and HDI trimer.

6. The two-component polyurethane thermally conductive structural adhesive according to claim 5, characterized in that, The isocyanate-terminated prepolymer was prepared by the following method, which includes the following steps: Polyol and isocyanate B are mixed and reacted to obtain the isocyanate-terminated prepolymer; Preferably, the mixing process further includes a pretreatment step, wherein the pretreatment method includes: dehydrating the polyol; Preferably, the dehydration process involves a vacuum degree ≤ -0.09 MPa, a temperature of 110-130℃, and a time of 1.5-2.5 h. Preferably, after the dehydration treatment, the water content of the polyol is <200 ppm; Preferably, the reaction temperature is 60-80°C; Preferably, the vacuum degree of the reaction is ≤-0.09 MPa; Preferably, the reaction is carried out under stirring at a speed of 80-120 rpm.

7. The two-component polyurethane thermally conductive structural adhesive according to any one of claims 1-6, characterized in that, Components A and B each independently include any one or a combination of at least two of the following: silica, molecular sieve, color paste, anti-aging agent, and water-absorbing agent. Preferably, the color paste A comprises a yellow color paste; Preferably, the color paste B comprises a blue color paste; Preferably, the weight percentage of silica in component A and component B is 0.5-5 parts each; Preferably, the molecular sieve in component A and component B each contains 1-5 parts by weight independently; Preferably, the weight percentage of the color paste in component A and component B is independently 0.1-1 parts; Preferably, the anti-aging agent in component A and component B is each 0.1-1 parts by weight. Preferably, the weight percentage of the water-absorbing agent in both component A and component B is 0.1-1 parts.

8. A method for preparing a two-component polyurethane thermally conductive structural adhesive as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: Preparation of component A: Mix and degas the components in component A to obtain component A; Preparation of component B: Mix the components in component B and degas to obtain component B; Preparation of two-component polyurethane thermally conductive structural adhesive: Component A and component B are mixed at a volume ratio of (0.8-1.2):1 to obtain the two-component polyurethane thermally conductive structural adhesive.

9. The preparation method according to claim 8, characterized in that, The methods for preparing component A and the method for mixing during the preparation of component B each independently include stirring, wherein the stirring speed is 450-550 rpm; Preferably, the degassing time for preparing component A and component B is independently 1-3 h; Preferably, the degassing is performed under a vacuum of ≤-0.09 MPa; Preferably, the water content of component A is <150 ppm.

10. A two-component polyurethane thermally conductive structural adhesive as described in any one of claims 1-7, characterized in that, The two-component polyurethane thermally conductive structural adhesive is used to prepare energy storage batteries.

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