A low-carbon two-component polyurethane potting compound for filters and its preparation method

Abstract

This invention relates to the field of polyurethane materials, and more particularly to a low-carbon two-component polyurethane potting compound for filters and its preparation method. The raw materials for preparing the polyurethane potting compound include component A and component B; component A includes MDI and a plasticizer; component B includes a bio-based polyol, PCE, silane-modified acrylate oligomer, filler, molecular sieve, colorant, catalyst, and functional additives. This invention utilizes PCE-330P synthesized from carbon dioxide to achieve low-carbon emissions. Combined with silane-modified acrylate oligomer and calcium carbonate filler, it significantly improves the tensile strength, adhesion, and aging resistance of the potting compound. The production process is simple and pollution-free, suitable for continuous operation of dispensing machines, and can efficiently ensure the long-term stable operation of filters.

Description

Technical Field

[0001] This invention relates to the field of polyurethane materials, and more particularly to a low-carbon two-component polyurethane potting compound for filters and its preparation method. Background Technology

[0002] Two-component polyurethane potting compound has become one of the core materials in filter manufacturing due to its excellent adhesion, sealing, insulation and environmental resistance. It can effectively isolate external adverse factors by forming a dense protective layer, ensuring the long-term stable operation of the filter under complex working conditions.

[0003] However, traditional polyurethane potting compounds currently on the market still have certain technical shortcomings, making it difficult to meet the dual demands of filter manufacturing and low-carbon development. On the one hand, traditional filter products mostly rely on castor oil and polyether polyols as core potting materials. The molecular structure of these materials inherently limits the mechanical strength, adhesive stability, and aging resistance of the potting compounds. In long-term high-temperature, high-humidity, or alternating hot and cold environments, traditional potting compounds are prone to problems such as hardness decay, cracking, and debonding. Especially in equipment such as filters that require long-term continuous operation, this often leads to filter failure, seriously affecting the reliability and service life of the equipment. On the other hand, the production process of traditional potting compounds does not fully implement the concept of low-carbon and environmental protection. The synthesis of raw materials relies heavily on fossil resources, and industrial waste gases and other wastes are not effectively utilized. This makes it impossible to adapt to the development needs of enterprises' green transformation and also limits the application of products in fields with high environmental protection requirements.

[0004] Furthermore, existing modification technologies for potting compound raw materials still have significant shortcomings, further restricting the improvement of filter product performance. While some modified oligomers attempt to improve potting compound performance, they generally suffer from complex production processes, harsh reaction conditions, and high pollution emissions, increasing production costs and failing to meet environmental protection requirements. Simultaneously, some modified materials exhibit poor compatibility with polyurethane systems, easily leading to defects such as phase separation and bubbles in filter products, thus affecting the overall protective effect of the potting compound. Therefore, developing a two-component polyurethane potting compound that possesses excellent mechanical strength, stable adhesion, and long-lasting aging resistance, aligns with low-carbon and environmentally friendly principles, and features a simple and pollution-free core raw material modification process has become a critical technical problem urgently needing to be solved in the filter manufacturing field. Summary of the Invention

[0005] To address the aforementioned technical problems, the first aspect of this invention provides a low-carbon two-component polyurethane potting compound for filters. The polyurethane potting compound is prepared from raw materials comprising component A and component B. Component A, by weight, comprises 10-20 parts MDI (diphenylmethane diisocyanate) and 10-20 parts plasticizer. Component B, by weight, comprises 20-50 parts bio-based polyol, 5-20 parts carbon dioxide-based polycarbonate polyether polyol (PCE), 5-15 parts silane-modified acrylate oligomer, 0-10 parts plasticizer, 30-60 parts filler, 5-10 parts molecular sieve, 0.1-5 parts colorant, 0.01-0.05 parts catalyst, and 0.02-0.1 parts functional additives. The hydroxyl value of the silane-modified acrylate oligomer is 90-120 mg KOH / g.

[0006] As an implementable example, the mass ratio of component A to component B is 1:(1-5).

[0007] As an implementable example, the MDI includes liquefied MDI and / or polymeric MDI.

[0008] As an implementable example, the plasticizer includes one or more of the following: dioctyl terephthalate, diisononyl cyclohexane-1,2-dicarboxylate, tributyl citrate, acetylated tributyl citrate, trioctyl trimellitate, polyol benzoate, isosorbide di-n-octanoate, dioctyl adipate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, or epoxidized soybean oil.

[0009] As an example of an implementable approach, the bio-based polyols include one or more of modified soybean oil, modified palm oil, castor oil, modified castor oil, or modified cashew nut shell oil.

[0010] As an example of an implementable case, the PCE has a hydroxyl value of 50-65 mg KOH / g and a viscosity of 1000-5000 mPa·s at 70°C.

[0011] Furthermore, the PCE has a hydroxyl value of 51-61 mgKOH / g, a viscosity of 1000-3000 mPa·s at 70°C, and the grade of the PCE is PCE-330P, which can be purchased from Hefei Puli Advanced Materials Technology Co., Ltd.

[0012] This invention selects PCE with a hydroxyl value of 51-61 mgKOH / g and a viscosity of 1000-3000 mPa·s at 70℃ as the reaction raw material. The hydroxyl value range of 51-61 mgKOH / g is excellently matched with castor oil and silane-modified acrylate oligomers with a hydroxyl value of 90-120 mgKOH / g in the formulation, and can form a suitable crosslinking density with the polymerization of MDI in component A. This avoids both excessively high hydroxyl value leading to overly dense crosslinking and material embrittlement, and insufficient crosslinking and decreased mechanical properties due to excessively low hydroxyl value, thus ensuring excellent tensile strength, hardness, and adhesion of the potting compound. Its moderate viscosity takes into account both production and use requirements, facilitating the preparation of component B with castor oil and filler. The raw materials, such as the coating material, are stirred and dispersed at high speed to avoid uneven mixing and air bubbles caused by high viscosity. On the other hand, it is beneficial to the flowability of components A and B during mixing, and is suitable for continuous operation of the dispensing machine to ensure a smooth potting process. At the same time, PCE-330P is synthesized from carbon dioxide and propylene oxide. It has a random block structure of polycarbonate and polyether, which has better compatibility with polyurethane system. It can give full play to its superior mechanical properties and weather resistance compared with ordinary polyether. At the same time, it is in line with the concept of low carbon emission reduction and can significantly improve the aging resistance of polyurethane potting compound, effectively making up for the shortcomings of traditional products in mechanical properties.

[0013] As an feasible example, the raw materials for preparing the silane-modified acrylate oligomer include, by mass parts, 100-200 parts solvent, 80-120 parts acrylate monomer, 1-10 parts initiator, and 1-10 parts isocyanate-based silane.

[0014] As an implementable example, the acrylate monomers include alkyl acrylates and hydroxyalkyl acrylates.

[0015] Furthermore, the acrylate monomers include at least one selected from isooctyl acrylate, butyl acrylate, ethyl acrylate, methyl acrylate, methyl methacrylate, and butyl methacrylate. The hydroxyalkyl acrylates include at least one selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate.

[0016] As an implementable example, the initiator includes one or more of the following: benzoyl peroxide (BOP), dilauroyl peroxide, diacetyl peroxide, dipropionyl peroxide, dibutyryl peroxide, di(2,4-dichlorobenzoyl peroxide), di(o-methylbenzoyl peroxide), di(p-chlorobenzoyl peroxide), tert-butyl peroxypentanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyneodecanate, di(1-hydroxycyclohexyl peroxide), methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, cyclohexanone peroxide, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, azobisisobutyronitrile, and azobisisovalerate.

[0017] As an implementable example, the isocyanate-based silane includes 3-isocyanate-propyltrimethoxysilane or 3-isocyanate-propyltriethoxysilane.

[0018] Furthermore, the preparation method of the silane-modified acrylate oligomer includes the following steps: S1. Mix 50-80% of the total solvent, 15-40% of the total acrylate monomer, and 15-40% of the total initiator, and heat to 60-90℃ to initiate polymerization to obtain the base material; mix the remaining solvent, remaining acrylate monomer, and remaining initiator into the base material and add them dropwise to carry out polymerization. After the dropwise addition is completed, keep the temperature at 60-90℃ for reaction. After the reaction is completed, cool down and desolventize under reduced pressure to obtain the acrylate oligomer. S2. Mix the acrylate oligomer and isocyanate-based silane and react for 1-3 hours to obtain the silane-modified acrylate oligomer.

[0019] Acrylic ester oligomers themselves have certain weather resistance and adhesion. The silane groups in isocyanate-based silanes have strong reactivity. After silane modification, they can form chemical bonds with hydroxyl, amino and other groups on the surface of the substrate. On the other hand, they can give the material better heat resistance and damp heat resistance, and can effectively resist the corrosion of high temperature and humid environment.

[0020] As an implementable example, the filler includes one or more of calcium carbonate, silica fume, alumina, talc, or bentonite.

[0021] Furthermore, the filler includes calcium carbonate with a particle size of 2-25 μm.

[0022] Furthermore, the calcium carbonate has particle sizes of 2 μm and 25 μm, and the mass ratio of 2 μm calcium carbonate to 25 μm calcium carbonate is (1-2):(1-2).

[0023] This invention limits the use of 2μm and 25μm calcium carbonate in combination. It can improve the density and mechanical properties of the system through synergistic particle size. Fine-particle calcium carbonate can fill the gaps between coarse-particle calcium carbonate to form a tightly packed structure, reduce the internal porosity of the potting compound, enhance the density of the protective layer, and improve tensile strength, hardness and impermeability. Meanwhile, coarse-particle calcium carbonate can avoid the viscosity spike caused by excessive agglomeration of fine powder, balance the reinforcing effect and material toughness, and prevent the polyurethane potting compound layer from becoming embrittled.

[0024] Furthermore, the catalyst comprises at least one of dibutyltin dilaurate, dibutyltin diacetate, stannous octanoate, bismuth neodecanoate, bismuth octanoate, bismuth isooctanoate, bismuth naphthenate, bismuth laurate, zinc octanoate, zinc isooctanoate, zinc neodecanoate, zinc naphthenate, or zinc laurate.

[0025] As an example of implementation, the functional additives include one or more of defoamers, antioxidants, UV stabilizers, or antibacterial agents, and functional additives can be rationally selected according to the actual product performance requirements.

[0026] A second aspect of this invention provides a method for preparing a low-carbon two-component polyurethane potting compound for filters, comprising the following steps: The plasticizer is heated to 100~120℃ and stirred. Then, it is vacuum dehydrated under -0.09~-0.095MPa, cooled to below 60℃, added MDI, stirred evenly, cooled to 40~45℃, filtered and discharged to obtain component A. PCE, bio-based polyol, plasticizer, and filler are mixed, heated to 100~120℃, stirred, and then dehydrated under vacuum at -0.09~-0.095MPa. After cooling to below 60℃, molecular sieve, silane-modified acrylate oligomer, color paste, functional additives, and catalyst are added in sequence. After stirring evenly, the mixture is cooled to 40~45℃, filtered, and discharged to obtain component B.

[0027] When using, simply mix component A and component B of the low-carbon two-component polyurethane potting compound for the filter in the specified ratio.

[0028] Beneficial effects (i) This invention significantly improves the tensile strength, hardness and adhesion of potting compound by compounding PCE with self-made silane-modified acrylate oligomer, far exceeding the traditional additive-free formulation.

[0029] (ii) The core raw material PCE of this invention is synthesized from carbon dioxide and propylene oxide in industrial and aquaculture waste gas, realizing the resource utilization of waste and replacing some traditional petrochemical-based raw materials, which is in line with the low-carbon concept. At the same time, the production process of silane-modified acrylate oligomers has no pollutant emissions, and the whole process practices the concept of green production.

[0030] (III) The excellent weather resistance of silane-modified acrylate oligomers combined with PCE allows the potting compound to maintain a hardness of over 40A after 24 hours of accelerated aging under saturated water vapor pressure at 143℃. This effectively delays hardness decay, cracking, and adhesion failure under high temperature and high humidity conditions, thus extending the service life of the filter.

[0031] (iv) The preparation method of the silane-modified acrylate oligomer of the present invention is simple, easy to industrialize, and the solvent can be recycled.

[0032] (v) The raw materials of each component of the present invention have good compatibility and no obvious phase separation or bubble defects; the auxiliary raw materials such as molecular sieves and environmentally friendly color pastes are selected to balance the stability of the system and the safety of use. Detailed Implementation

[0033] In Examples 1-6 of this invention, the raw materials for preparing component A in Comparative Examples 1-2, by mass parts, include 15 parts of polymeric MDI and 15 parts of epoxidized soybean oil, wherein the polymeric MDI is branded WANNATE PM-200 and purchased from Wanhua Chemical.

[0034] In Examples 1-6 and Comparative Examples 1-2 of this invention, two types of silane-modified acrylate oligomers, namely oligomer 1# and oligomer 2#, are used.

[0035] The preparation method of the oligomer 1# is as follows: S1. Mix 100g of isopropanol, 15g of butyl acrylate, 5g of hydroxyethyl acrylate, and 1g of BPO, and heat to 80~85℃ to obtain the base material. S2. Weigh 50g of isopropanol, 60g of butyl acrylate, 20g of hydroxyethyl acrylate, and 4g of BPO. Mix and dissolve them evenly. Add the mixture dropwise after the product base material from step S1 has been initiated. The addition should be completed in 1.5 hours. S3, keep the reaction at 80±2℃ for 1.5h, then cool down to 60℃; S4. The solvent is removed under reduced pressure at 50~60℃ and -0.09MPa to obtain the acrylate oligomer. S5. Heat 100 parts of acrylate oligomer to 100~120℃, remove water under vacuum at -0.09~0.095MPa, cool down to 60℃, add 5 parts of 3-isocyanate-propyltrimethoxysilane, keep the reaction at 60℃ for 2 hours, cool down to below 40℃, filter and discharge to obtain oligomer 1#. Oligomer 1# is a yellow transparent liquid with a hydroxyl value of 100±5 mgKOH / g.

[0036] The preparation method of the oligomer 2# is as follows: S1. Mix 100g of isopropanol, 20g of butyl acrylate, 10g of hydroxyethyl acrylate, and 2g of BPO, and heat to 80~85℃ to obtain the base material; S2. Weigh 50g of isopropanol, 50g of butyl acrylate, 20g of hydroxyethyl acrylate, and 3g of BPO. Mix and dissolve them evenly. Add the mixture dropwise after the product base from step S1 has been initiated. The addition should be completed in 1.5 hours. S3, keep the reaction at 80±2℃ for 1.5h, then cool down to 60℃; S4. The solvent is removed under reduced pressure at 50~60℃ and -0.09MPa to obtain the acrylate oligomer. S5. Heat 100 parts of acrylate oligomer to 100~120℃, remove water under vacuum at -0.09~-0.095MPa, cool down to 60℃, add 10 parts of 3-isocyanate-propyltrimethoxysilane, keep the reaction at 60℃ for 2h, cool down to below 40℃, filter and discharge to obtain oligomer 2#. Oligomer 2# is a yellow transparent liquid with a hydroxyl value of 105±5 mgKOH / g.

[0037] For component B in Examples 1-6 and Comparative Examples 1-2, the information and mass fractions of the raw materials used in its preparation are shown in Table 1.

[0038] Table 1

[0039] The castor oil is refined grade 1 commercially available castor oil; the PCE has a hydroxyl value of 51-61 mgKOH / g, a viscosity of 1000-3000 mPa·s at 70℃, and is brand name PCE-330P, purchased from Hefei Puli Advanced Materials Technology Co., Ltd.; the polyether polyol is brand name PPG-310, purchased from Shandong Lanxing Dongda Chemical Co., Ltd.; the plasticizer is epoxidized soybean oil; the filler is calcium carbonate with a particle size of 2μm and 25μm, and the weight ratio of 2μm calcium carbonate to 25μm calcium carbonate is 1:1; the molecular sieve is 5A low-alkalinity molecular sieve with pH=8-9, purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.; the functional additive is BYK-A535 defoamer, purchased from BYK Chemical; the color paste is purchased from Shanghai Jiasheng New Materials Co., Ltd.; and the catalyst is dibutyltin dilaurate.

[0040] The preparation method of the two-component polyurethane potting compound for low-carbon filters in Examples 1-6 of this invention is as follows: The plasticizer is heated to 120°C and stirred. Then, it is dehydrated under vacuum at -0.09MPa and cooled to below 60°C. MDI is added and stirred evenly. The mixture is then cooled to 45°C and filtered to obtain component A. PCE, castor oil, plasticizer, and filler are mixed, heated to 120°C, stirred, and then dehydrated under vacuum at -0.09 to -0.095 MPa. After cooling to below 60°C, molecular sieve, silane-modified acrylate oligomer, color paste, functional additives, and catalyst are added in sequence. After stirring evenly, the mixture is cooled to 45°C, filtered, and discharged to obtain component B.

[0041] In this invention, the preparation method of component A in the two-component polyurethane potting compound for the filter in Comparative Example 1 is the same as in Examples 1-6, and the preparation method of component B is as follows: Castor oil, plasticizer, and filler are mixed, heated to 120°C, stirred, and then dehydrated under vacuum at -0.09 to -0.095 MPa. The mixture is then cooled to below 60°C, and molecular sieve, color paste, functional additives, and catalyst are added in sequence. After stirring evenly, the mixture is cooled to 40 to 45°C, filtered, and discharged to obtain component B.

[0042] In this invention, the preparation method of component A in the two-component polyurethane potting compound for the filter in Comparative Example 2 is the same as in Examples 1-6, and the preparation method of component B is as follows: Polyether polyol PPG-310, castor oil, plasticizer, and filler are mixed, heated to 120°C, stirred, and then dehydrated under vacuum at -0.09~-0.095 MPa. After cooling to below 60°C, molecular sieve, color paste, functional additives, and catalyst are added in sequence. After stirring evenly, the mixture is cooled to 45°C, filtered, and discharged to obtain component B.

[0043] Performance Evaluation Curing conditions for polyurethane potting compound: Mix components A and B evenly (mass ratio of components A to B is 30:100), and cure at room temperature (23±2℃) for 7 days.

[0044] 1. Tensile test: The polyurethane potting compounds prepared according to Examples 1-6 and Comparative Examples 1-2 were tested according to the national standard GB / T 1040.3-2006.

[0045] 2. Hardness test: The polyurethane potting compounds prepared according to Examples 1-6 and Comparative Examples 1-2 were tested according to the national standard GB / T 531.1-2008.

[0046] 3. Shear test The polyurethane potting compound prepared according to national standard GB / T 2174-2008 in Examples 1-6 and Comparative Examples 1-2 was tested; the substrates for testing were ABS board and aluminum board.

[0047] 4. Accelerated aging test at 143℃ Mix the polyurethane potting compound components A and B of Examples 1-6 and Comparative Examples 1-2 evenly, pour the mixture into a mold with a thickness of 10 mm and a diameter of 50 mm, cure at room temperature of 25°C for 7 days, and then place the sample under saturated water vapor pressure of 143°C for 8 h, 16 h, and 24 h to observe and test, and record the hardness.

[0048] The test results for the above tests are detailed in Table 2.

[0049] Table 2

[0050] Table 2 shows that the tensile strength, Shore hardness, and shear strength against ABS boards and aluminum substrates of Examples 1-6, which include PCE-330P and silane-modified acrylate oligomers, are significantly higher than those of Comparative Examples 1-2, which do not contain these two core ingredients. Example 6 exhibits the best performance, demonstrating that the addition of these two core ingredients can significantly improve the mechanical strength and adhesiveness of the potting compound. A comparison of the examples shows that as the amount of PCE-330P and silane-modified acrylate oligomers increases, the tensile strength, hardness, and shear strength generally increase, reflecting the synergistic effect of the two on performance. Enhancement effect: In the accelerated aging test at 143℃, the hardness of Examples 1-6 after aging for 8h, 16h, and 24h was higher than that of Comparative Examples 1-2. After 24 hours, the hardness remained above 40A, and the hardness decay rate was slower, indicating that the synergistic effect of PCE and silane-modified acrylate oligomer can significantly improve the high-temperature aging resistance of the potting compound. In contrast, the comparative examples without the two core raw materials not only had significantly lower mechanical strength and adhesion, but also significantly insufficient aging resistance, with hardness of only 30A and 32A after 24h aging. This further verifies the necessity of the formulation design of this invention for improving the performance of polyurethane potting compounds.

Claims

1. A low-carbon two-component polyurethane potting compound for filters, characterized in that, The raw materials for preparation include component A and component B; the raw materials for component A include MDI and plasticizer; the raw materials for component B include bio-based polyol, carbon dioxide-based polycarbonate polyether polyol PCE, silane-modified acrylate oligomer, filler, molecular sieve, color paste, catalyst, and functional additives. The raw materials for preparing the silane-modified acrylate oligomer, by mass parts, include 100-200 parts solvent, 80-120 parts acrylate monomer, 1-10 parts initiator, and 1-10 parts isocyanate-based silane; the hydroxyl value of the silane-modified acrylate oligomer is 90-120 KOH / g. The acrylate monomers include alkyl acrylates and hydroxyalkyl acrylates; the alkyl acrylates include at least one of isooctyl acrylate, butyl acrylate, ethyl acrylate, methyl acrylate, methyl methacrylate, and butyl methacrylate; the hydroxyalkyl acrylates include at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate. The isocyanate-based silane includes 3-isocyanate-propyltrimethoxysilane or 3-isocyanate-propyltriethoxysilane; The PCE has a hydroxyl value of 50-65 mg KOH / g and a viscosity of 1000-5000 mPa·s at 70°C.

2. The low-carbon two-component polyurethane potting compound for filters according to claim 1, characterized in that, The MDI includes liquefied MDI and / or polymeric MDI.

3. The low-carbon two-component polyurethane potting compound for filters according to claim 1, characterized in that, The raw materials for preparing component B also include plasticizers; The plasticizer includes one or more of the following: dioctyl terephthalate, diisononyl cyclohexane-1,2-dicarboxylate, tributyl citrate, acetylated tributyl citrate, trioctyl trimellitate, polyol benzoate, isosorbide di-n-octyl ester, dioctyl adipate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, or epoxidized soybean oil.

4. The low-carbon two-component polyurethane potting compound for filters according to claim 1, characterized in that, The bio-based polyols include one or more of modified soybean oil, modified palm oil, castor oil, modified castor oil, or modified cashew nut shell oil.

5. The low-carbon two-component polyurethane potting compound for filters according to claim 1, characterized in that, The PCE has a hydroxyl value of 51-61 mgKOH / g and a viscosity of 1000-3000 mPa·s at 70°C.

6. The low-carbon two-component polyurethane potting compound for filters according to claim 1, characterized in that, The preparation method of the silane-modified acrylate oligomer includes the following steps: S1. Mix 50-80% of the total solvent, 15-40% of the total acrylate monomer, and 15-40% of the total initiator, and heat to 60-90℃ to initiate polymerization to obtain the base material; mix the remaining solvent, remaining acrylate monomer, and remaining initiator into the base material and add them dropwise for polymerization. After the dropwise addition is completed, keep the reaction at 60-90℃. After the reaction is completed, cool down and remove the solvent under reduced pressure to obtain the acrylate oligomer. S2. Mix and react the acrylate oligomer with isocyanate-based silane to obtain silane-modified acrylate oligomer.

7. A method for preparing a low-carbon two-component polyurethane potting compound for filters according to any one of claims 1-6, characterized in that, Includes the following steps: The plasticizer is heated to 100~120℃ and stirred. It is then vacuum dehydrated under -0.09~-0.095MPa, cooled to below 60℃, and MDI is added. After stirring evenly, the mixture is cooled to 40~45℃, filtered, and discharged to obtain component A. PCE, bio-based polyol, plasticizer, and filler are mixed and heated to 100~120℃. The mixture is stirred and dehydrated under vacuum at -0.09~-0.095MPa. After cooling to below 60℃, molecular sieve, silane-modified acrylate oligomer, color paste, functional additives, and catalyst are added sequentially. After stirring evenly, the mixture is cooled to 40~45℃ and filtered to obtain component B.

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