A high thixotropic polyurethane composition and its preparation method and application

Abstract

The application discloses a kind of high thixotropy polyurethane compositions and its preparation method and application.The polyurethane composition includes: A) isocyanate component, B) isocyanate reactive component;Wherein, component B) includes the following composition: B1) fused ring amine class;B2) polyether polyol 1, functionality is 2-5, hydroxyl value is 200-800mgKOH / g, and the content of ethylene oxide in its polymerization monomer is 20-100%, calculated as the total mass of propylene oxide and ethylene oxide;Optionally B3) polyether polyol 2, functionality is 2-4, hydroxyl value is 20-170mgKOH / g, and the content of ethylene oxide is 0-20%, calculated as the total mass of propylene oxide and ethylene oxide;B4) polyether polyol 3 is polymerized by propylene oxide, functionality 2-4, and hydroxyl value is 150-600mgKOH / g.The polyurethane composition in the application has high thixotropy, and viscosity is large and does not flow under pressure-free state, and has good flowability under pressure state.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane materials technology, specifically relating to a highly thixotropic polyurethane composition, its preparation method, and its application. Background Technology

[0002] With the rapid development of the automotive industry and the implementation of the national development strategy for new energy electric vehicles, society has an increasing demand for lightweight, low-energy-consumption, and high-safety materials. The production of lightweight composite molded automotive interior and exterior parts has become a consensus and a major direction for development in the automotive industry. Therefore, high-strength and lightweight sandwich composite materials are receiving strong market attention, and domestic and international automotive brands have been using high-performance engineering plastics and plastic composite materials on a large scale to reduce vehicle weight.

[0003] Polyurethane foam, with its advantages of excellent lightweight, superior environmental performance, low production cost, and high malleability, can be used in the production of complex shapes and large-sized products. As a new type of foaming material, polyurethane foam is being widely used in wind turbine blades, automotive interior and exterior trim, building materials, ship hulls, and other applications.

[0004] Honeycomb reinforced polyurethane composite structures are materials developed in recent years for molding in the high-performance, lightweight automotive field. These structures are composed of polyurethane foam, fiber reinforcement, and honeycomb composites, using materials such as paper honeycomb, metal honeycomb, and plastic honeycomb. These reinforced composite structures offer advantages such as light weight, high flexural strength, good dimensional stability, environmental friendliness, high production efficiency, and flexible design. Compared to traditional automotive interior and exterior trim structures, they can reduce weight by 30% while maintaining the same stiffness, meeting market demands and significantly reducing manufacturing costs. The material also possesses environmentally friendly properties such as flame retardancy, low odor, and low emissions. Because polyurethane honeycomb composite sandwich products combine aesthetics, safety, lightweight, environmental friendliness, and low cost, they meet the rapidly evolving needs of the automotive industry.

[0005] The current process for preparing honeycomb sandwich materials is as follows: the honeycomb structure is used as the core material, and the two sides of the core material are reinforced fiber felt or fiber cloth. The polyurethane composition is sprayed on one side of the reinforced fiber felt or fiber cloth. The fixture is flipped over, and the spraying operation is repeated on the other side until double-sided spraying is completed. The product is placed in the mold, and the polyurethane composition foams, levels, cures and is demolded in the mold under certain pressure and temperature.

[0006] Currently, conventional polyurethane compositions sprayed onto reinforcing fibers require flipping the product to coat the other side. This process results in significant dripping of the polyurethane material, leading to a substantial decrease in material utilization and increased costs. Furthermore, the dripping polyurethane composition pollutes the environment after foaming, requiring frequent cleaning. More importantly, the dripping polyurethane composition prevents the product from being fully filled at the edges or in shaped areas. This is especially problematic for large-sized, complex-shaped products, resulting in severe material shortages or hollowness, which affects the product's mechanical strength and aesthetics.

[0007] As described in patent CN110964173A, this patent discloses the preparation of a honeycomb composite polyurethane composition, and the prepared product has low emission and low water absorption. However, this patent has the disadvantages of not having a rapid thickening effect after mixing the polyurethane composition, having a large amount of dripping during the raw material spraying and turning process, resulting in insufficient raw material utilization, increased cost, and easy incomplete filling of the product's shaped area.

[0008] In existing technologies, the mixing viscosity of polyurethane compositions is increased through physical or chemical reactions to achieve the anti-dripping effect.

[0009] In terms of physical thickening, powder fillers such as silica and glass microspheres are usually purchased on the market to increase the initial viscosity of the raw materials. However, due to the high initial viscosity of the raw materials, the mixing requirements of the equipment are very high. At the same time, due to the presence of powder, the storage stability and processability of the raw materials are very poor. Furthermore, the polyurethane composition is prone to clogging the nozzle during the mixing process, which leads to instability in the product production process and a significant increase in the overall cost.

[0010] In terms of chemical thickening, most products on the market use highly reactive DETDA to achieve the effect of thickening the raw materials and play a role in preventing dripping during the spraying process. Because DETDA has a fast reaction activity and a high degree of cross-linking in the early stage, the viscosity of the polyurethane composition increases significantly immediately after mixing. Although this method has a good anti-dripping effect, the actual production process still requires many operations such as spraying, placing in the mold, and closing the mold, which requires the polyurethane composition to have a long working period. However, due to the presence of DETDA, the polyurethane composition undergoes a deep cross-linking reaction instantly, and the fluidity of the raw materials decreases significantly. This is very unfavorable for molding complex shapes or large-sized products. Often, there will be defects such as material shortage, large pinholes, and uneven flow in the shaped area. Therefore, this solution is usually only suitable for the production of products with simple shapes and small sizes.

[0011] As described in patent CN101641384B, this patent discloses a polyurethane system for preparing polyurethane sandwich components. Due to the use of the highly active chain extender DETDA, the viscosity of the polyurethane composition increases significantly during mixing, achieving a good anti-sagging effect and improving raw material utilization. However, it is precisely because of the presence of DETDA that the viscosity of the polyurethane composition increases significantly during mixing, and the initial cross-linking degree of the mixture is already large, with no thixotropy. This leads to a significant decrease in the fluidity of the mixture in the mold, which is not conducive to the molding of large-sized and complex-shaped products.

[0012] Therefore, in order to solve the problems existing in the prior art, the present invention provides a highly thixotropic polyurethane composition. The isocyanate component and the isocyanate reactive component can quickly achieve high thixotropy after mixing. Under no pressure, the viscosity is relatively high (apparently non-flowing) and has excellent sagging effect. When the product enters the mold and is subjected to a certain pressure, the viscosity can be significantly reduced. It can maintain fluidity for a long time at both room temperature and high temperature, promoting surface leveling. The composite sandwich products prepared from the polyurethane composition have high surface density, excellent filling effect, high aesthetics, and excellent mechanical properties. The polyurethane composition is suitable for preparing sandwich materials with complex shapes and large dimensions. Summary of the Invention

[0013] To address the above technical problems, this invention proposes a highly thixotropic polyurethane composition, its preparation method, and its application.

[0014] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0015] A highly thixotropic polyurethane composition comprising: A) an isocyanate component, and B) an isocyanate reactive component;

[0016] Component B includes the following components:

[0017] B1) Fused-ring amines with a functionality of 1-6, preferably 2-4;

[0018] B2) Polyether polyol 1, with a functionality of 2-5, preferably 3-4, and a hydroxyl value of 200-800 mgKOH / g, preferably 400-700 mgKOH / g, wherein the ethylene oxide content in its monomer is 20-100%, preferably 60-100%, based on the total mass of propylene oxide and ethylene oxide;

[0019] Optionally B3) Polyether polyol 2, with a functionality of 2-4, a hydroxyl value of 20-170 mgKOH / g, and an ethylene oxide content of 0-20%, based on the total mass of propylene oxide and ethylene oxide;

[0020] Optionally B4) Polyether polyol 3, polymerized from propylene oxide, with a functionality of 2-4 and a hydroxyl value of 150-600 mgKOH / g, preferably 240-500 mgKOH / g.

[0021] In some preferred embodiments, the ratio of components A and B, expressed as the molar number of isocyanate groups to the molar number of active hydrogen atoms, is (1.5-2.5):1, preferably (1.6-2.1):1; wherein, active hydrogen atoms refer to hydrogen atoms capable of reacting with isocyanate groups.

[0022] Preferably, in component B1), the mass ratio of polyether polyol 1, polyether polyol 2, and polyether polyol 3 is (20-70):(0-10):(5-50), more preferably (35-55):(0-5):(15-35).

[0023] In some preferred embodiments, the isocyanate component is selected from polyisocyanates, preferably polyphenylmethane polyisocyanates, and more preferably one or more of Wanhua Chemical WANNATE 82681, Wanhua Chemical WANNATE PM-8215, Huntsman 5005, Covestro 44V20, and BASF M20S; polyphenylmethane polyisocyanates are isocyanate compounds known in the art, and their technical information can be found in Section 1.2 of the "Handbook of Polyurethane Raw Materials and Additives" (edited by Liu Yijun) published by Chemical Industry Press.

[0024] Preferably, the molecular weight of the polyether polyol 1 is 200-600;

[0025] Preferably, the molecular weight of the polyether polyol 2 is 1000-8000;

[0026] Preferably, the molecular weight of the polyether polyol 3 is 300-1000.

[0027] The above-mentioned polyether polyols can be obtained commercially or prepared using methods commonly used in the field. The functionality of the polyether polyol refers to the functionality of the initiator. For example, initiators for polyether polyols with a functionality of 2 can be selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, diethylene glycol, neopentyl glycol, etc.; initiators for polyether polyols with a functionality of 3 can be selected from glycerol, trimethylolpropane, triisopropanolamine, etc.

[0028] In some preferred embodiments, the fused-ring amine is selected from one or more of 1,5-diaminonaphthalene, 1,4-diaminoanthraquinone, 1,3,6,8-tetraaminopyrene, 2,3-diaminonaphthalene, and 1,8-diaminonaphthalene.

[0029] In some preferred embodiments, component B) further includes B5) a small molecule alcohol with a functionality of 1-4, preferably 2-3; the small molecule alcohol is preferably one or more of ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, diethylene glycol, neopentanediol, glycerol, and trimethylolpropane.

[0030] In some preferred embodiments, component B) further includes catalyst B6); said catalyst is selected from organometallic catalysts and / or amine catalysts, more preferably one or more of triethylamine, tributylamine, triethylenediamine, tetramethyl-ethylenediamine, pentamethyldiethylenetriamine, N,N-methylaniline, N,N-dimethylaniline, stannous octoate, stannous oleate, stannous laurate, dimethyl stannous dilaurate, dibutyl stannous dilaurate, dibutyl dithiol stannous, bismuth octoate, bismuth octanate, and bismuth cycloalkanoate.

[0031] In some preferred embodiments, component B) further includes a foaming agent; the foaming agent is selected from physical foaming agents and / or chemical foaming agents, preferably one or more of water, halogenated hydrocarbons, and hydrocarbon compounds; the amount of foaming agent used generally depends on the required polyurethane foam density.

[0032] Preferably, the haloalkane is one or more selected from monochlorodifluoromethane, dichloromonofluoromethane, dichlorofluoromethane, and trichlorofluoromethane;

[0033] Preferably, the hydrocarbon compound is one or more selected from butane, pentane, cyclopentane, hexane, cyclohexane, and heptane.

[0034] In some preferred embodiments, component B) further includes one or more of surfactants, antioxidants, dispersants, anti-hydrolysis agents, antistatic agents, viscosity reducers, crosslinking agents, internal release agents, flame retardants, pigments, fillers, foaming stabilizers, and light stabilizers.

[0035] The surfactants include, but are not limited to, organosilicones, polyols, silicones, sulfonated fatty alcohols, sulfonated fatty acids, and other nonionic surfactants.

[0036] As a preferred formulation, component B) comprises, by weight, the following substances in the following amounts:

[0037] Polycyclic amines: 0.3-2%, preferably 0.5-1.2%;

[0038] Polyether polyol 1 20-70%, preferably 35-55%;

[0039] Polyether polyol 2 0-10%, preferably 0-5%;

[0040] Polyether polyol 35-50%, preferably 15-35%;

[0041] Small molecule alcohols, 5-35%, preferably 10-26%;

[0042] Catalyst 0-1%, preferably 0.1-0.5%;

[0043] The foaming agent is 0-1.5%, preferably 0.5-1%;

[0044] Surfactant 0-3%, preferably 0.8-2%.

[0045] The polyurethane composition described in this invention, through the compounding of specific isocyanate components and isocyanate reactive components, can achieve rapid pre-crosslinking and chain extension reactions in the early stage of the reaction, resulting in high thixotropy. It has a high viscosity under no pressure and exhibits excellent sag effect; under certain pressure, the viscosity decreases significantly, and it can maintain excellent fluidity at room temperature, while also exhibiting excellent fluidity at high temperatures. The foam prepared from the polyurethane composition and the sandwich material prepared from it have excellent surface quality and mechanical properties.

[0046] As a further provision of this invention, a method for preparing a highly thixotropic polyurethane composition foam as described above is provided in a preferred embodiment, wherein the isocyanate component and the isocyanate reactive component are uniformly mixed using a polyurethane foaming machine, and the mixed raw material is poured into a mold. The main steps include:

[0047] The isocyanate component is mixed evenly at a temperature of 10-45°C;

[0048] The isocyanate reactive components are mixed evenly at a temperature of 10-45°C;

[0049] The isocyanate component and the isocyanate reactive component are uniformly mixed using a high-pressure machine, and the mixture is poured into a mold. The polyurethane composition foams, expands and fills in the mold. The mold temperature is controlled at 80-130℃ for curing. After curing is complete in 1-5 minutes, the mold is cooled and the material is removed, which is the polyurethane composition foam.

[0050] The present invention also provides the application of the highly thixotropic polyurethane composition as described above in automotive sandwich materials and composite materials.

[0051] The polyurethane composition can be sprayed onto the surface of the sandwich material. The sandwich material comprises a core layer and a reinforcing layer, wherein the core layer includes, but is not limited to, one or more of foam materials, paper honeycomb, metal honeycomb, and plastic honeycomb; the reinforcing layer includes, but is not limited to, one or more of glass fiber, carbon fiber, metal fiber, natural fiber, aramid fiber, and polyethylene fiber.

[0052] As a further provision of the present invention, in a preferred embodiment of the method for preparing the sandwich material, paper honeycomb is used as the core material, and glass fiber mat is used as the reinforcing layers on both sides of the core material; isocyanate components and isocyanate reactive components are uniformly mixed using a polyurethane foaming machine, and the mixed raw material is sprayed onto one side of the glass fiber mat. The fixture is flipped over, and the spraying operation is repeated on the other side until double-sided spraying is completed. The sandwich product is then placed into a mold. The main steps include:

[0053] The isocyanate component is mixed evenly at a temperature of 10-45°C;

[0054] The isocyanate reactive components are mixed evenly at a temperature of 10-45°C;

[0055] The isocyanate component and the reactive isocyanate component are uniformly mixed using a polyurethane foaming machine, and the mixture is sprayed onto both sides of the glass fiber mat. The polyurethane composition flows, foams, and expands in the gaps between the glass fiber mat and the paper honeycomb, producing polyurethane foam that fills the cavity of the interlayer material. The mold temperature is controlled at 100-130℃ for curing. After curing is complete in 1-2 minutes, the product is removed, thus forming the polyurethane composition interlayer material.

[0056] This invention provides a highly thixotropic polyurethane composition. The isocyanate component and the isocyanate reactive component can rapidly achieve high thixotropy after mixing. Under no pressure, it has a high viscosity (apparently non-flowing) and excellent sagging effect. However, when the product enters the mold and is subjected to a certain pressure, the viscosity can be significantly reduced. It maintains fluidity for a long time at both room temperature and high temperature, promoting surface leveling. The sandwich material prepared from this polyurethane composition has high surface density, excellent filling effect, high aesthetics, and excellent mechanical properties. This polyurethane composition is particularly suitable for preparing sandwich materials with complex shapes and large dimensions. Detailed Implementation

[0057] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0058] The main raw material information used in the following embodiments and comparative examples of this invention is as follows:

[0059] Isocyanate component: WANNATE 82681, NCO content 31.5wt%, Wanhua Chemical;

[0060] Isocyanate component: Huntsman 5005, NCO content 31.1 wt%, Huntsman;

[0061] Isocyanate composition: Covestro 44V20, NCO content 31.4wt%, Covestro;

[0062] 1,5-Diaminonaphthalene, commercially available;

[0063] 1,4-Diaminoanthraquinone, commercially available;

[0064] 1,3,6,8-Tetraaminopyrene, commercially available;

[0065] DETDA, diethyltoluene diamine, commercially available;

[0066] Polyether polyol 1-1, starting with glycerol, with a hydroxyl value of 600 mg KOH / g, polymerized from propylene oxide and ethylene oxide, with an ethylene oxide content of 95%, based on the total mass of propylene oxide and ethylene oxide;

[0067] Polyether polyol 1-2, starting with glycerol, hydroxyl value 450mgKOH / g, polymerized from propylene oxide and ethylene oxide, ethylene oxide content 65%, based on the total mass of propylene oxide and ethylene oxide;

[0068] Polyether polyol 2-1, starting with pentaerythritol, with a hydroxyl value of 110 mg KOH / g, polymerized from propylene oxide and ethylene oxide, with an ethylene oxide content of 5%, based on the total mass of propylene oxide and ethylene oxide;

[0069] Polyether polyol 2-2, glycerol-based, hydroxyl value 65 mg KOH / g, polymerized from propylene oxide and ethylene oxide, ethylene oxide content 15%, based on the total mass of propylene oxide and ethylene oxide;

[0070] Polyether polyol 2-3, starting with glycerol, hydroxyl value 24 mgKOH / g, polymerized from propylene oxide and ethylene oxide, ethylene oxide content 12%, based on the total mass of propylene oxide and ethylene oxide;

[0071] Polyether polyol 3-1, starting with propylene glycol, hydroxyl value of 280 mg KOH / g, polymerized with propylene oxide;

[0072] Polyether polyol 3-2, glycerol-initiated, hydroxyl value 490 mg KOH / g, propylene oxide polymerization;

[0073] Glycerin (GL) and diethylene glycol (DEG) are commercially available.

[0074] Surfactants: B8002, B8715, Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0075] Catalyst 1: KC152, purchased from Wanhua Chemical;

[0076] Catalyst 2: SA102, purchased from Air Chemical Company, USA;

[0077] Foaming agent: water.

[0078] The main test methods or standards used for the polyurethane compositions or their foams in the following embodiments and comparative examples of this invention are as follows:

[0079] Viscosity test standard: GB / T 12008.7-2010; Take 100g of polyurethane composition, control the raw material temperature at 25±1℃, put it in a 500ml paper cup, adjust the speed as required, mix for 10 seconds, and immediately conduct actual viscosity tests at different speeds; Observe the apparent flowability by vertically inverting the polyurethane composition; Evaluate thixotropy through actual viscosity and apparent flowability;

[0080] Raw material sagging evaluation: Take 100g of polyurethane composition, control the raw material temperature at 25±1℃, put it in a 500ml paper cup, rotate at 3000r / min, mix according to the ratio for 10 seconds, then immediately invert the paper cup vertically, restart the timing, and record the mass of polyurethane composition that flows out of the paper cup within 20 seconds.

[0081] High-temperature flowability evaluation: The raw material temperature is controlled at 25±1℃. Take 10g of the uniformly mixed polyurethane composition, put it into a circular mold with a diameter of 8cm and a thickness of 2mm, and the mold temperature is 110℃. Use a glass rod to detect the flowability time of the polyurethane composition.

[0082] The main test methods or standards used for sandwich articles prepared from the polyurethane compositions in the examples and comparative examples are as follows:

[0083] Product density testing standard: GB / T 6343;

[0084] Compressive strength test standard: GB / T 8813-2020;

[0085] Tensile strength test standard: GB / T 528-2009;

[0086] Bending strength test standard: GB / T 8812-2007;

[0087] Impact strength test standard: GB / T 1043-2008;

[0088] Product drip evaluation: The total weight of raw materials dripping during the flipping process of sandwich products is denoted as M. When M ≤ 5 grams, the drip effect is excellent; when 5 < M ≤ 50 grams, the drip effect is average; when M > 50 grams, the drip effect is poor.

[0089] Product surface density evaluation: honeycomb paper sandwich products have a density of 100cm. 2The number of pits with a diameter of 0.5 mm or larger is used as the evaluation standard; when the number of pits is ≤5, the surface density of the product is excellent; when 5 < number of pits ≤15, the surface density of the product is average; when 15 < number of pits ≤30, the surface density of the product is poor; when the number of pits >30, the surface density of the product is extremely poor.

[0090] Evaluation of surface filling effect: The honeycomb paper sandwich product has dimensions of 1.5m*1.5m*2cm. The evaluation standard is the area of ​​missing material on the top and bottom surfaces and edges of the product; when the missing material area is ≤3cm², the evaluation is considered satisfactory. 2 The surface filling effect of the product is excellent; 3cm 2 Area of ​​missing material ≤ 10cm 2 The surface filling effect of the product is average; 10cm 2 Area of ​​missing material ≤ 30cm 2 The surface filling effect of the product is poor; the area of ​​missing material is >30cm². 2 The surface filling effect of the product is extremely poor.

[0091] The amounts of each component of the polyurethane composition in the embodiments and comparative examples of the present invention are listed in Table 1, by mass.

[0092] Table 1

[0093]

[0094]

[0095] Referring to the formulations in Table 1, the raw materials for the polyurethane compositions in each example and comparative example were prepared. The isocyanate component and the isocyanate reactive component were uniformly mixed using a polyurethane foaming machine; a paper honeycomb structure was used as the core material, 2 cm thick and 1.5 m * 1.5 m in size, with fiberglass mats on both sides of the core material, the surface density of which was 450 g / m³. 2 The mixed polyurethane raw material is sprayed onto one side of the fiberglass felt (0.55 kg of polyurethane raw material is sprayed on one side per square meter). The fixture is flipped over, and the operation is repeated to spray the other side until double-sided spraying is completed. The sandwich product is placed into the mold, and the polyurethane composition flows, foams, and expands in the gap between the fiberglass felt and the paper honeycomb, producing polyurethane foam that fills the cavity of the sandwich material. The mold temperature is controlled at 100-130℃ for curing. After curing is complete in 1-2 minutes, the product is taken out, thus forming the polyurethane composition sandwich product.

[0096] The surface density, surface filling effect and mechanical properties of the above polyurethane composition sandwich products were tested, and the results are listed in Table 2.

[0097] Table 2

[0098]

[0099] A comparison of Tables 1 and 2 above shows that:

[0100] Comparative Example 1 and Comparative Example 1 show that when the polyurethane composition does not contain fused cyclic amines, the thickening and thixotropic effects of the product are very poor, the raw material sagging effect is very poor, resulting in extremely poor surface density and surface filling effect of the final product.

[0101] Comparative Example 3 and Comparative Example 2 show that when DETDA, a commonly used compound on the market, is used instead of polycyclic amines, the thickening and anti-dripping effects of the product are very good, but the thixotropy is poor, the viscosity decreases slowly with increasing shear, the product has poor flowability when under pressure in the mold, and the high-temperature flow time is too short, resulting in poor surface density and filling effect of the final product.

[0102] Comparative Example 1 and Comparative Example 3 show that when the amount of polyether polyol 2 exceeds 10%, the polyurethane composition cannot form foam normally due to differences in reactivity. At the same time, the thickening and thixotropic effects of the polyurethane composition are poor, resulting in extremely poor surface density of the product and poor surface filling effect.

[0103] Comparative Example 6 and Comparative Example 4 show that when the amount of polyether polyol 1 is less than 20%, the polyurethane composition has no obvious thickening and thixotropic effect due to the low content of highly active polyether, resulting in poor anti-drip effect and poor surface density and filling effect of the product.

[0104] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A high thixotropic polyurethane composition, characterized in that, It comprises: A) an isocyanate component, B) an isocyanate-reactive component; wherein component B) comprises the following components: B1) a condensed ring amine with a functionality of 1-6; B2) a polyether polyol 1 with a functionality of 2-5 and a hydroxyl value of 200-800 mgKOH / g, and a content of ethylene oxide in the polymerized monomers of 60-100% based on the total mass of propylene oxide and ethylene oxide; B3) a polyether polyol 2 with a functionality of 2-4, a hydroxyl value of 20-170 mgKOH / g, and a content of ethylene oxide of 0-20% based on the total mass of propylene oxide and ethylene oxide; B4) a polyether polyol 3 polymerized from propylene oxide, with a functionality of 2-4 and a hydroxyl value of 150-600 mgKOH / g; In component B), the mass ratio of polyether polyol 1, polyether polyol 2, and polyether polyol 3 is (20-70):(0-10):(5-50); component B) comprises 0.3-2% of the condensed ring amine based on the total mass of 100%; The mass ratio of component A) to component B) is (1.5-2.5):1 based on the molar number of isocyanate groups to the molar number of active hydrogen atoms.

2. The highly thixotropic polyurethane composition according to claim 1, characterized in that, The condensed ring amine has a functionality of 2-4.

3. The highly thixotropic polyurethane composition according to claim 1, characterized in that, The polyether polyol 1 has a functionality of 3-4 and a hydroxyl value of 400-700 mgKOH / g.

4. The highly thixotropic polyurethane composition according to claim 1, characterized in that, The polyether polyol 3 has a hydroxyl value of 240-500 mgKOH / g.

5. The highly thixotropic polyurethane composition according to claim 1, characterized in that, The mass ratio of component A) to component B) is (1.6-2.1):1 based on the molar number of isocyanate groups to the molar number of active hydrogen atoms.

6. The highly thixotropic polyurethane composition according to claim 1, characterized in that, In component B), the mass ratio of polyether polyol 1, polyether polyol 2, and polyether polyol 3 is (35-55):(0-5):(15-35).

7. The highly thixotropic polyurethane composition according to claim 1, characterized in that, The isocyanate component is selected from polyisocyanates.

8. The highly thixotropic polyurethane composition according to claim 7, characterized in that, The polyisocyanate is a polymethylene polyphenylmethane polyisocyanate.

9. The highly thixotropic polyurethane composition according to claim 7, characterized in that, The polyisocyanate is one or more of Wanhua WANNATE 82681, Wanhua WANNATE PM-8215, Huntsman 5005, Covestro 44V20, and BASF M20S.

10. The high thixotropic polyurethane composition according to claim 7, characterized in that, The polyether polyol 1 has a molecular weight of 200-600.

11. The highly thixotropic polyurethane composition according to claim 7, characterized in that, The polyether polyol 2 has a molecular weight of 1000-8000.

12. The high thixotropic polyurethane composition according to claim 7, characterized in that, The polyether polyol 3 has a molecular weight of 300-1000.

13. The highly thixotropic polyurethane composition according to any one of claims 1 to 12, characterized in that, The condensed ring amine is selected from one or more of 1,5-diaminonaphthalene, 1,4-diaminoanthraquinone, 1,3,6,8-tetraaminopyrene, 2,3-diaminonaphthalene, and 1,8-diaminonaphthalene.

14. The highly thixotropic polyurethane composition according to any one of claims 1 to 12, characterized in that, Component B) further comprises B5) a small molecule alcohol with a functionality of 1-4.

15. The highly thixotropic polyurethane composition according to claim 14, characterized in that, The small molecule alcohol has a functionality of 2-3.

16. The high thixotropic polyurethane composition according to claim 14, characterized in that, The small molecule alcohol is one or more of ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,2-pentanediol, hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, neopentyl glycol, glycerol, and trimethylolpropane.

17. The highly thixotropic polyurethane composition according to any one of claims 1 to 12, characterized in that, Component B) further comprises B6) a catalyst; the catalyst is selected from organometallic catalysts and / or amine catalysts.

18. The highly thixotropic polyurethane composition according to claim 17, characterized in that, The catalyst is selected from one or more of triethylamine, tributylamine, triethylene diamine, tetramethyl-ethylenediamine, pentamethyldiethylene-triamine, N-methylaniline, N,N-dimethylaniline, stannous octoate, stannous oleate, tin laurate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dithiol, bismuth neodecanoate, bismuth naphthenate.

19. The highly thixotropic polyurethane composition according to any one of claims 1 to 12, characterized in that, Component B) further comprises a blowing agent; the blowing agent is selected from a physical blowing agent and / or a chemical blowing agent.

20. The highly thixotropic polyurethane composition according to claim 19, characterized in that, The blowing agent is selected from one or more of water, a halogenated hydrocarbon, a hydrocarbon compound.

21. The highly thixotropic polyurethane composition according to claim 20, characterized in that, The halogenated hydrocarbon is one or more of monochlorodifluoromethane, dichloromonofluoromethane, dichlorofluoromethane, trichlorofluoromethane.

22. The high thixotropic polyurethane composition according to claim 20, characterized in that, The hydrocarbon compound is one or more of butane, pentane, cyclopentane, hexane, cyclohexane, heptane.

23. The highly thixotropic polyurethane composition according to any one of claims 1-12, characterized in that, Component B) further comprises one or more of a surfactant, an antioxidant, a dispersing agent, an anti-hydrolysis agent, an antistatic agent, a viscosity reducing agent, a crosslinking agent, an internal release agent, a flame retardant, a pigment, a filler, a blowing stabilizer, a light stabilizer.

24. The highly thixotropic polyurethane composition according to any one of claims 1-12, characterized in that, Component B) comprises the following amounts of substances, based on 100% of the total mass: 0.3-2% of a condensed ring amine; 20-70% of polyether polyol 1 ; 0-10% of polyether polyol 2; 5-35% of a small molecule alcohol; 0-1% of a catalyst; 0-1.5 of a blowing agent; 0-3 of a surfactant. Component B) comprises the following amounts of substances, based on 100% of the total mass:

25. The highly thixotropic polyurethane composition according to claim 24, characterized in that, 0.5-1.2% of a condensed ring amine; 35-55% of polyether polyol 1 ; 0-5% of polyether polyol 2; 15-35% of polyether polyol 3; 10-26% of a small molecule alcohol; 0.1-0.5% of a catalyst; 0.5-1% of a blowing agent; 0.8-2% of a surfactant.

26. Use of the high thixotropic polyurethane composition according to any one of claims 1-25 in automotive sandwich materials and composites. ​

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