A silicone / polyurethane / epoxy resin composite emulsion, a preparation method and application thereof

Abstract

This invention provides a silicone / polyurethane / epoxy resin composite emulsion, its preparation method, and its application. It is prepared by the following steps: (1) after dehydration of polyethylene glycol and hydroxyl silicone oil, diisocyanate is added, and the mixture is heated to prepare a silicone / polyurethane prepolymer; (2) a hydrophilic chain extender is added to continue the reaction, resulting in a hydrophilic silicone / polyurethane prepolymer; (3) a diluent and epoxy resin are added, and the reaction yields a silicone / polyurethane / epoxy resin composite resin system; (4) a neutralizing agent is added after cooling; (5) water is added under high-speed stirring to form a silicone / polyurethane / epoxy resin composite emulsion; (6) the diluent is removed by vacuum distillation. The silicone / polyurethane / epoxy resin composite emulsion provided by this invention, when combined with a water-based curing agent, can be used to reinforce glass fiber filter media for lubricating oil filtration. The reinforced filter media can meet the requirements of pleating processes and high-temperature lubricating oil applications at 220℃.

Description

Technical Field

[0001] This invention belongs to the technical field of polymer materials and filter materials, specifically relating to an organosilicon / polyurethane / epoxy resin composite emulsion, its preparation method, and its application in high-temperature resistant lubricating oil filter materials. Background Technology

[0002] Lubricating oil plays a crucial role in the lubrication systems of aircraft and ship engines, reducing friction, minimizing wear, cooling, and preventing corrosion; it is often referred to as the "blood" of mechanical equipment. Practice shows that lubricating oil is easily contaminated by solid particles and water molecules, leading to fatigue wear and pitting, which in turn affects the service life of the equipment. There are many measures to prevent and control oil contamination, among which using a high-precision lubricating oil system filter for fine filtration is the most effective method. Lubricating oil filtration devices are used to remove contaminants generated by wear and corrosion of moving parts or introduced into the system from the outside, ensuring the contamination level of the engine lubrication system, preventing high-precision mating parts from jamming or pipeline blockage, which could cause system performance degradation or functional loss, and ensuring system reliability. The filter paper layer is the core technology of the filter element. It is generally made from glass fibers to obtain glass fiber filter materials. However, due to the poor bonding strength between glass fibers, they are easily dispersed by the working fluid medium. Therefore, it is necessary to modify the glass fibers with reinforcing resin to improve the physical and application properties of the filter material to meet processing and application requirements.

[0003] In recent years, with the continuous increase in the speed of vehicles, the operating temperature of lubricating oil systems has been gradually increased. Especially in some special or abnormal operating environments, short-term temperatures can reach over 220°C, placing higher demands on the high-temperature resistance of filter media and binding resins. On the other hand, the cylindrical pleated filter elements produced during the manufacturing process of lubricating oil filters can greatly improve the effective filtration area and dirt-holding capacity. In terms of pleat design, the pleat shape, indentation pressure, and depth are crucial to the filtration effect of the molded filter. The filter paper layer reinforced by resin should have bending processing properties and be able to prevent collapse in practical applications. In addition, filter media are also subject to the pulse effects of circulating flow, startup, impact, and vibration. This requires that the reinforcing resin, in addition to high-temperature resistance, bonding properties, and strength, should also have excellent toughness to ensure that the filter media meets the requirements of pleating processing and the pulse effects during application.

[0004] Traditional reinforcing resins for lubricating oil filter glass fiber media are mostly thermoplastic acrylic resins, which have advantages such as good water and chemical resistance, easy processing and molding, convenient construction, and environmental friendliness. US Patent 2015360156 reports a filter media layer obtained by impregnating glass fibers with 5% thermoplastic acrylic resin HYCAR 26120 (Lubrizol); foreign patent WO 2011087840 also reports the application of a reinforcing resin system composed of a 1:1 mixture of thermoplastic acrylic Eco32S (Rohm & Haas) and thermosetting acrylic HF-05A (Rohm & Haas); Chinese patent CN 109930425 reports a reinforcing resin composed of acrylic emulsion and curing agent PF7302B; another Chinese patent CN 103191605 also uses a reinforcing resin system composed of thermoplastic and thermosetting acrylic resins in a 1:1 ratio. However, thermoplastic acrylic resins have a low degree of crosslinking, causing the resin to swell and soften at high temperatures due to oil, thus damaging the filter media structure. Even adding thermosetting resins or other crosslinking agents cannot solve this problem. To address the high-temperature resistance issue, Chinese patent CN 110066359 describes the preparation of a water-soluble thermosetting acrylic resin that exhibits good performance after immersion in oil at 150°C. However, this system has a high curing temperature and is prone to aging, strength reduction, and decreased pulse resistance at temperatures exceeding 150°C. In summary, although acrylic resin is currently the most widely used resin in lubricating oil filter media, domestic and international products can no longer meet the requirements for filter elements operating in lubricating oil environments at 220°C.

[0005] Phenolic resin and epoxy resin are two important thermosetting reinforcing resins. Due to their excellent bonding properties, strength properties, and high-temperature and solvent resistance, they are also excellent reinforcing resin systems for glass fiber filter media. For example, the embodiments in patents CN105233569 and WO 2016040292 attempt to impregnate glass fibers with phenolic resin to obtain oil filter paper. However, commercially available phenolic resins are mainly solvent-based products, posing safety hazards during production and processing, and containing free phenol and formaldehyde, failing to meet green environmental protection requirements. Furthermore, phenolic resins have high curing temperatures and high brittleness after curing, resulting in poor processing performance of glass fiber paper products. Therefore, the application of phenolic resin-reinforced lubricating oil filter paper is rarely reported. The rigid skeleton and ether bond structure of epoxy resin endow it with good heat resistance and oil resistance. At the same time, water-based design of epoxy resin also provides safety and environmental friendliness. Therefore, some foreign products currently use epoxy resin as a reinforcing resin to meet the high-temperature resistance requirements of filter media, which can improve the chemical resistance and physical properties of the filter media to a certain extent. However, the epoxy resin system has poor toughness, which reduces the strength of the filter paper after bending, making it unable to meet the processing requirements. US Patent 2012248034 reports a reinforcing resin obtained by curing 75% toughened epoxy resin EPIREZ 5520W60 (Hexion) and 25% amine curing agent EPIKURE 8537WY60 (Hexion) at 105-120°C. However, it does not describe the structure, composition, or preparation method of the modified epoxy resin, and the processing performance of the treated glass fiber products still fails to meet the pleating requirements. Therefore, glass fiber products treated with this epoxy resin are mainly used in wound-wound filters.

[0006] With the changing application scope and working environment of lubricating oil systems, higher requirements (220℃) are placed on the high-temperature oil resistance and bonding performance of reinforcing resins. The currently disclosed filter media products or reinforcing resins cannot meet the actual application processing requirements. Therefore, there is an urgent need to find an environmentally friendly reinforcing resin system that can withstand higher temperatures and improve the processing performance of the reinforced filter media. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a silicone / polyurethane / epoxy resin composite emulsion. First, polyurethane, with its excellent oil resistance and elasticity, is selected as the toughening resin system. Second, silicone structural segments with excellent high-temperature resistance are introduced into the flexible segments of the polyurethane to further enhance its high-temperature resistance. Finally, epoxy resin, with its excellent high-temperature resistance, bonding strength, and chemical resistance, is further introduced into the resin system structure, ultimately forming a silicone / polyurethane / epoxy resin composite system. This composite resin system can simultaneously possess the excellent properties of epoxy resin, polyurethane, and silicone materials, and can compensate for their respective deficiencies. Furthermore, due to the introduction of hydrophilic polyethylene glycol flexible segments and hydrophilic chain extenders with hydrophilic groups into this composite resin system, the combined effect of these two components enables the composite resin to be water-based, becoming an environmentally friendly water-based resin system. The organosilicon / polyurethane / epoxy resin composite emulsion prepared in this invention, when applied to the impregnation of glass fiber filter media, not only imparts excellent tensile strength and its retention rate to the filter media, thus meeting the requirements for pleating the reinforced filter media, but also gives the reinforced filter media excellent oil resistance and high temperature resistance, meeting the application requirements of high-temperature lubricating oil at 220℃.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] This invention provides a method for preparing an organosilicon / polyurethane / epoxy resin composite emulsion, which is prepared by a method comprising the following steps:

[0010] I. In a reactor equipped with a stirring device, a condensing device, a nitrogen protection device, and a temperature control device, dehydrated polyethylene glycol, hydroxyl silicone oil, and a measured amount of diisocyanate are stirred evenly, and the mixture is heated to 70-80℃ at room temperature for 2-4 hours to prepare an organosilicon / polyurethane prepolymer.

[0011] II. Add a measured amount of hydrophilic chain extender, heat to 75-85℃ and react for 1-3 hours to prepare a hydrophilic organosilicon / polyurethane prepolymer;

[0012] III. Add measured amounts of epoxy resin and diluent, heat to 80-90℃ and react for 4-6 hours to prepare an organosilicon / polyurethane / epoxy resin composite resin system;

[0013] IV. Cool to 40-50℃, add neutralizing agent, and stir well;

[0014] V. Slowly add deionized water (2-4 times the mass of the composite resin) to the reaction system while stirring at 800-3000 rpm to form an organosilicon / polyurethane / epoxy resin composite emulsion;

[0015] VI. Reduced pressure distillation to remove most of the diluent;

[0016] The silicone / polyurethane / epoxy resin composite emulsion can be obtained by completing the above steps.

[0017] Furthermore, the diisocyanate is an aliphatic or alicyclic isocyanate monomer containing two -NCO groups in its structure.

[0018] Preferably, the diisocyanate is selected from one or more of isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), 1,4-cyclohexane diisocyanate (CHDI), trimethyl-1,6-hexamethylene diisocyanate (TMHDI), and cyclohexanedimethylene diisocyanate (HXDI) in any proportion.

[0019] Furthermore, the molecular weight of the polyethylene glycol is in the range of 800 to 3000. Preferably, the molecular weight of the polyethylene glycol is 1000 to 2000.

[0020] Furthermore, the molecular weight of the hydroxyl silicone oil ranges from 500 to 2000. Preferably, the molecular weight of the hydroxyl silicone oil is from 800 to 1500.

[0021] Further, the molar ratio of polyethylene glycol to hydroxyl silicone oil is 4:1-9:1. Preferably, the molar ratio of polyethylene glycol to hydroxyl silicone oil is 4:1-6:1.

[0022] Further, the total amount of polyethylene glycol and hydroxyl silicone oil in the molar ratio to diisocyanate is 1:3-1:4. Preferably, the total amount of polyethylene glycol and hydroxyl silicone oil in the molar ratio to diisocyanate is 1:3.5-1:3.8.

[0023] Furthermore, the hydrophilic chain extender is a carboxylic acid or sulfonic acid type hydrophilic chain extender containing two -OH groups in its structure, specifically one of 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 1,4-butanediol-2-sulfonic acid, and 1,2-dihydroxy-3-propanesulfonic acid.

[0024] Preferably, the hydrophilic chain extender is selected from one of 2,2-dimethylolpropionic acid and 2,2-dimethylolbutyric acid.

[0025] Further, the molar ratio of the hydrophilic chain extender to the diisocyanate is 1:3 to 1:7. Preferably, the molar ratio of the hydrophilic chain extender to the diisocyanate is 1:4 to 1:6.

[0026] Furthermore, the epoxy resin is a bisphenol A type or bisphenol F type epoxy resin having the following molecular structural formula:

[0027]

[0028] Wherein, the value of n1 ranges from 0.85 to 1.43 (epoxy value 0.27 to 0.34), and the value of n2 ranges from 0.95 to 1.35 (epoxy value 0.30 to 0.36). Preferably, the value of n1 ranges from 1.03 to 1.34 (epoxy value 0.28 to 0.32), and the value of n2 ranges from 1.07 to 1.28 (epoxy value 0.31 to 0.34).

[0029] Further, the mass ratio of epoxy resin to hydrophilic silicone / polyurethane prepolymer is 0.8:1-1.4:1. Preferably, the mass ratio of epoxy resin to hydrophilic silicone / polyurethane prepolymer is 1.0:1-1.2:1.

[0030] Further, the diluent is methyl ethyl ketone (MEK), and the amount of diluent added is 40%-100% of the mass of the epoxy resin. Preferably, the amount of diluent added is 60%-80% of the mass of the epoxy resin.

[0031] Further, the neutralizing agent is one or more of N,N-dimethylethanolamine, triethylamine, and sodium hydroxide in any proportion. Preferably, triethylamine is selected as the neutralizing agent.

[0032] Further, the molar ratio of the neutralizing agent to the hydrophilic chain extender is 1.1:1-1.4:1. Preferably, the molar ratio of the neutralizing agent to the hydrophilic chain extender is 1.2:1-1.3:1.

[0033] This invention provides an organosilicon / polyurethane / epoxy resin composite emulsion prepared by the above preparation method.

[0034] This invention also provides a method for applying the above-mentioned silicone / polyurethane / epoxy resin composite emulsion to a lubricating oil glass fiber filter material. Specifically, the silicone / polyurethane / epoxy resin composite emulsion is diluted with deionized water, and a measured amount of aqueous curing agent is added to form a reinforcing resin impregnation solution, which is used to impregnate glass fiber base paper to prepare a high-performance glass fiber filter material for lubricating oil filtration. It is prepared by a method including the following steps:

[0035] Ⅰ. Dilute the aforementioned silicone / polyurethane / epoxy resin composite emulsion with deionized water, and add a measured amount of water-based curing agent to form a reinforced resin impregnation solution;

[0036] II. The glass fiber base paper is impregnated in the above-mentioned reinforcing resin impregnation solution; and dried in the range of 80-100°C to form glass fiber filter material, wherein the amount of sizing in the reinforcing resin impregnation solution is 5.0±0.5% based on the weight of the glass fiber base paper;

[0037] III. Pleat the above-mentioned glass fiber filter material to make a filter element, dry it, and cure it at 110-150℃ for 15-30 minutes.

[0038] Furthermore, the water-based curing agent is one of a water-based polyamide curing agent or a water-based polyetheramine curing agent. Preferably, the water-based curing agent is a water-based polyamide curing agent.

[0039] Furthermore, the silicone / polyurethane / epoxy resin composite emulsion and the water-based curing agent are compounded according to the principle that the epoxy equivalent is equal to the active hydrogen equivalent.

[0040] The glass fiber filter material for lubricating oil filtration prepared above has excellent comprehensive performance. It not only retains the excellent tensile strength and retention rate of the filter material, but also has oil resistance, high temperature resistance, bonding performance and high toughness.

[0041] The beneficial technical effects of this invention are reflected in:

[0042] (1) The organosilicon / polyurethane / epoxy resin composite emulsion of the present invention is a homogeneous composite resin system formed by chemical bonding between organosilicon, polyurethane, and epoxy resin. Specifically, it is manifested in the following ways: First, polyethylene glycol and hydroxyl silicone oil are blended, and the terminal -OH groups of both react simultaneously with the -NCO groups of diisocyanate to generate a terminal -NCO group type organosilicon / polyurethane prepolymer. This process can overcome the situation where the poor compatibility between the hydrophobic silicone oil and the hydrophilic polyethylene glycol components in the system may lead to phase separation, thereby forming a homogeneous system. Then, by strictly controlling the number of hydroxyl groups in the bisphenol epoxy resin that undergo grafting reaction with the prepolymer, it is ensured that the organosilicon / polyurethane / epoxy resin composite system formed by chemical bonding does not undergo gelation during the reaction, thus ensuring the stability of the composite system. Finally, by neutralizing the carboxyl groups, hydrophilic properties are imparted, thereby achieving dual modification of the toughness and water solubility of the epoxy resin. Therefore, this silicone / polyurethane / epoxy resin composite resin system, while being water-soluble, can simultaneously possess the excellent oil resistance and elasticity of polyurethane, the high temperature resistance and toughness of silicone, and the high temperature resistance, oil resistance and adhesion of epoxy resin.

[0043] (2) The glass fiber filter material reinforced by the organosilicon / polyurethane / epoxy resin composite emulsion of the present invention can meet both the requirements for pleating the filter material and the requirements for application of the filter material under high temperature lubricating oil conditions.

[0044] (3) The silicone / polyurethane / epoxy resin composite emulsion of the present invention introduces hydrophilic polyethylene glycol molecular chain segments and hydrophilic carboxylate / sulfonate groups into the structure, thereby enabling it to form a stable water-dispersible resin emulsion through phase inversion. After removing the solvent by vacuum distillation, the resulting silicone / polyurethane / epoxy resin composite emulsion is an environmentally friendly product that can meet the environmental protection requirements of glass fiber filter materials in the sizing and processing process. Attached Figure Description

[0045] The present invention will now be described in detail with reference to the accompanying drawings.

[0046] Figure 1 This is a schematic diagram of the process flow for the organosilicon / polyurethane / epoxy resin composite emulsion, its preparation method, and its application as described in this invention.

[0047] Figure 2 SEM image of fiberglass base paper (magnified 1000 times).

[0048] Figures 3a to 3f SEM images (magnified 1000x) of the high-performance glass fiber filter media for lubricating oil filtration (organosilicon / polyurethane / epoxy resin composite emulsions of Examples 1-6) prepared in Examples 7-12.

[0049] Figure 4 SEM image (1000x magnification) of the high-performance glass fiber filter material for lubricating oil filtration prepared for Comparative Example 8 (organosilicon / polyurethane / epoxy resin composite emulsion of Comparative Example 2).

[0050] Figure 5 SEM image (1000x magnification) of the high-performance glass fiber filter material for lubricating oil filtration (a water-soluble thermosetting acrylic resin as described in patent CN 110066359 A) prepared for Comparative Example 9.

[0051] Figure 6 SEM image (1000x magnification) of the high-performance glass fiber filter media (commercially available waterborne epoxy resin) for lubricating oil filtration prepared for Comparative Example 10. Detailed Implementation

[0052] The following specific embodiments further illustrate an organosilicon / polyurethane / epoxy resin composite emulsion, its preparation method, and its application. Those skilled in the art will understand that these embodiments are for illustrative purposes only, but the scope of protection of the present invention is not limited thereto.

[0053] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all raw materials and reagents used in the following examples are commercially available products.

[0054] In the following examples, the water-based curing agent used in the silicone / polyurethane / epoxy resin composite emulsion is a commercially available water-based polyamide curing agent.

[0055] Examples 1-6

[0056] Examples 1-6 prepared an organosilicon / polyurethane / epoxy resin composite emulsion. The raw material composition is shown in Table 1, and the process flow is as follows: Figure 1 As shown, it is prepared by a method including the following steps:

[0057] I. In a reactor equipped with a stirring device, a condensing device, a nitrogen protection device, and a temperature control device, dehydrated polyethylene glycol, hydroxyl silicone oil, and diisocyanate are stirred evenly, and the mixture is heated to 70-80℃ at room temperature for 2-4 hours to prepare an organosilicon / polyurethane prepolymer.

[0058] II. Add a hydrophilic chain extender, heat to 75-85℃ and react for 1-3 hours to prepare a hydrophilic organosilicon / polyurethane prepolymer;

[0059] III. By adding epoxy resin and methyl ethyl ketone and reacting at 80-90℃ for 4-6 hours, an organosilicon / polyurethane / epoxy resin composite resin system can be prepared.

[0060] IV. Cool to 40-50℃, add triethylamine, and stir until homogeneous;

[0061] V. While stirring at 2000 rpm, slowly add sufficient deionized water (2-4 times the mass of the composite resin) to the reaction system to form an organosilicon / polyurethane / epoxy resin composite emulsion. After the phase inversion is complete, continue stirring for 1-2 hours.

[0062] VI. Remove the diluent methyl ethyl ketone by vacuum distillation at 60℃ and -0.08 MPa;

[0063] The above steps will yield the silicone / polyurethane / epoxy resin composite emulsion, and the results are shown in Table 1.

[0064] Table 1. Raw material composition of silicone / polyurethane / epoxy resin composite emulsions in Examples 1-6

[0065]

[0066]

[0067] As shown in Table 1, all of Examples 1-6, within the scope of this invention, can form stable emulsions with a bluish sheen. Replacing the hydrophilic chain extender in Examples 1-6 with 1,4-butanediol-2-sulfonic acid and 1,2-dihydroxy-3-propanesulfonic acid also yields silicone / polyurethane / epoxy resin composite emulsions that meet the above requirements.

[0068] Comparative Examples 1-6

[0069] Comparative Examples 1-6 prepared an organosilicon / polyurethane / epoxy resin composite emulsion. The raw material composition is shown in Table 2. The preparation was carried out according to the same steps and methods as Examples 1-6, and the results are shown in Table 2.

[0070] Table 2. Raw material composition of silicone / polyurethane / epoxy resin composite emulsions in Comparative Examples 1–6

[0071]

[0072]

[0073] Compared with Examples 1-6, it can be found that Comparative Example 1, using low molecular weight polyethylene glycol, could not form an emulsion; Comparative Example 2, lacking silicone components, formed a stable emulsion, but its resistance to high-temperature oil at 220°C was poor (see Comparative Example 8 in Table 3 below); Comparative Example 3 used too little diisocyanate, resulting in an unstable emulsion; Comparative Example 4 used too little hydrophilic chain extender, resulting in an unstable emulsion; Comparative Example 5 had a high epoxy value of epoxy resin, causing gelation in the composite resin system; Comparative Example 6 used too little neutralizer, resulting in an unstable emulsion and stratification of the system. Therefore, it is evident that without following the method of this invention, it is impossible to form a silicone / polyurethane / epoxy resin composite emulsion with excellent stability.

[0074] Examples 7-12

[0075] Examples 7-12 describe the preparation of a high-performance glass fiber filter material for lubricating oil filtration using the silicone / polyurethane / epoxy resin composite emulsions of Examples 1-6.

[0076] The silicone / polyurethane / epoxy resin composite emulsions prepared in Examples 1-6 above were diluted with deionized water, and a measured amount of aqueous curing agent was added to form a reinforced resin impregnation solution. This solution was used to impregnate glass fiber base paper (Guangzhou Huachuang Chemical Materials Technology Development Co., Ltd., model 8510, composed of glass wool and chopped glass fibers) to prepare a high-performance glass fiber filter material for lubricating oil filtration. This material was prepared by a method including the following steps:

[0077] I. The silicone / polyurethane / epoxy resin composite emulsions of Examples 1-6 were diluted with deionized water, and then a measured amount of waterborne curing agent (Westlake, EPIKURE™ Curing Agent 8537-WY-60, active hydrogen equivalent of 174 g / eq) was added according to Table 3 to form a reinforced resin impregnation solution. The reinforced resin impregnation solution was prepared by mixing the silicone / polyurethane / epoxy resin composite emulsion with the waterborne curing agent according to the theoretical value that the epoxy equivalent equals the active hydrogen equivalent.

[0078] Table 3. Mixing ratio of silicone / polyurethane / epoxy resin composite emulsion to water-based curing agent

[0079] Example 7 78.4％ 21.6％ Example 8 77.9％ 22.1％ Example 9 79.2％ 20.8％ Example 10 78.2％ 21.8％ Example 11 77.3％ 22.7％ Example 12 77.3％ 22.7％

[0080] II. The glass fiber base paper is impregnated in the above-mentioned reinforcing resin impregnation solution; dried at 80-100°C to form glass fiber filter material. The amount of sizing in the reinforcing resin impregnation solution is 5.0 ± 0.5% based on the weight of the glass fiber base paper.

[0081] III. Pleat the above-mentioned glass fiber filter material to make a filter element, dry it, and cure it at 120℃ for 15 minutes.

[0082] The high-performance glass fiber filter material prepared above was observed by scanning electron microscopy. The scanning electron micrographs of Examples 7-12 are shown below. Figures 3a to 3f . Figure 2 SEM images of fiberglass base paper, and Figure 2 In comparison, it can be seen that the high-performance glass fiber filter material obtained by applying the silicone / polyurethane / epoxy resin composite emulsion to the glass fiber base paper in the embodiments of the present invention can maintain an excellent pore structure and does not show obvious pore blockage. Therefore, the silicone / polyurethane / epoxy resin composite emulsion does not have a significant impact on the filtration performance of the filter material.

[0083] Comparative Example 7

[0084] Comparative Example 7 prepared an organosilicon / polyurethane / epoxy resin composite emulsion with the raw material composition as shown in Example 1 of Table 1. It was prepared according to the same steps and methods as Examples 1-6, with the difference being:

[0085] I. Polyethylene glycol, hydroxyl silicone oil, hydrophilic chain extender and diisocyanate are stirred together until homogeneous, and then heated to 75°C at room temperature for 4 hours to prepare hydrophilic organosilicon / polyurethane prepolymer;

[0086] II. The hydrophilic chain extender is added in step I.

[0087] In the comparative example, the silicone / polyurethane / epoxy resin composite emulsion prepared quickly gelled during the preparation of the hydrophilic silicone / polyurethane prepolymer, preventing further reaction. This demonstrates that without following the method of this invention, it is impossible to form a silicone / polyurethane / epoxy resin composite emulsion with excellent stability.

[0088] Comparative Example 8

[0089] This example demonstrates the preparation of a high-performance glass fiber filter material for lubricating oil filtration. The high-performance glass fiber filter material for lubricating oil filtration described in this comparative example was prepared using essentially the same steps as in Examples 7-12, with the following differences:

[0090] I. The silicone / polyurethane / epoxy resin composite emulsion used was obtained in Comparative Example 2. In particular, Comparative Example 2 did not contain silicone resin and was called a polyurethane / epoxy resin composite emulsion; wherein, the mixing ratio of the polyurethane / epoxy resin composite emulsion and the water-based curing agent was 77.9%:22.1%;

[0091] II. The glass fiber base paper is impregnated in a reinforcing resin impregnation solution to obtain Comparative Example 8 (polyurethane / epoxy resin composite emulsion) type high-performance glass fiber filter material.

[0092] The high-performance glass fiber filter material prepared above was observed by scanning electron microscopy. The scanning electron micrograph of Comparative Example 8 is shown below. Figure 4 .

[0093] from Figure 4 It can be seen that the high-performance glass fiber filter material obtained by applying the polyurethane / epoxy resin composite emulsion of Comparative Example 2 to the glass fiber base paper can maintain an excellent pore structure and no obvious pore blockage phenomenon is observed.

[0094] Comparative Example 9

[0095] This example demonstrates the preparation of a high-performance glass fiber filter material for lubricating oil filtration. The high-performance glass fiber filter material for lubricating oil filtration described in this comparative example was prepared using essentially the same steps as in Examples 7-12, with the following differences:

[0096] I. The water-soluble thermosetting acrylic resin described in patent CN 110066359 A (Example 1) is used instead of the silicone / polyurethane / epoxy resin composite emulsion described in Examples 7 to 12, and no curing agent is used;

[0097] II. The glass fiber base paper is impregnated in a reinforcing resin impregnation solution to obtain Comparative Example 9 (water-soluble thermosetting acrylic resin) type high-performance glass fiber filter material.

[0098] The high-performance glass fiber filter material prepared above was observed by scanning electron microscopy. The scanning electron micrograph of Comparative Example 9 is shown in [image missing]. Figure 5 .

[0099] from Figure 5 It can be seen that the high-performance glass fiber filter material obtained by applying the water-soluble thermosetting acrylic resin of patent CN 110066359 A to glass fiber base paper can maintain an excellent pore structure and does not show obvious pore blockage.

[0100] Comparative Example 10

[0101] This example demonstrates the preparation of a high-performance glass fiber filter material for lubricating oil filtration. The high-performance glass fiber filter material for lubricating oil filtration described in this comparative example was prepared using essentially the same steps as in Examples 7-12, with the following differences:

[0102] I. Select commercially available waterborne epoxy resin (Westlake, model EPI-REZ) TM Resin 5520-W-60 (epoxy equivalent of 480-560 g / eq) replaces the silicone / polyurethane / epoxy resin composite emulsions described in Examples 7-12; wherein, the mixing ratio of waterborne epoxy resin to waterborne curing agent is 75.0%:25.0%.

[0103] II. The glass fiber base paper is impregnated in a reinforcing resin impregnation solution to obtain a high-performance glass fiber filter material of Comparative Example 10 (commercially available waterborne epoxy resin).

[0104] The high-performance glass fiber filter material prepared above was observed by scanning electron microscopy. The scanning electron microscope image of Comparative Example 10 is shown below. Figure 6 .

[0105] from Figure 6 It can be seen that the high-performance glass fiber filter material obtained by applying commercially available water-based epoxy resin to glass fiber base paper can maintain an excellent pore structure and does not show obvious pore blockage.

[0106] Test Example 1

[0107] The pleating performance of the high-performance glass fiber filter media for lubricating oil filtration obtained in Examples 7-12 and the high-performance glass fiber filter media for lubricating oil filtration obtained in Comparative Examples 8-10 was determined.

[0108] The basis weight, tensile strength, and stiffness of the high-performance glass fiber filter media for lubricating oil filtration prepared by the glass fiber base paper (Guangzhou Huachuang Chemical Materials Technology Development Co., Ltd., model 8510, composed of glass wool and chopped glass fiber), Examples 7-12, and Comparative Examples 8-10 were measured, as well as the tensile strength after pleating. The test results are shown in Table 4.

[0109] Table 4. Test results of pleating performance of high-performance glass fiber filter media for lubricating oil filtration in each embodiment and comparative example.

[0110]

[0111]

[0112] The pleating performance was evaluated as follows: Referring to the national standard (GB / T 17939-2015), specifically Appendix A.3.6 (Flexibility). The filter paper was cut longitudinally into samples 300 mm long and 150 mm wide. Within a length of (250 ± 12) mm, the sample was bent longitudinally perpendicular to a 5 mm diameter shaft, with a bending radius of 180°, and the bending was repeated once. After the test, the filter material was considered to have passed if there were no cracks, breaks, fissures, or delamination.

[0113] Stiffness was measured in accordance with the national standard (GB / T 22364-2018) using a bending stiffness tester (model: 79-25-00-0002, TMI Corporation, USA); tensile strength was measured in accordance with the national standard (GB / T 12914-2018) using a tensile strength tester (model: CE062, L&W Company, Sweden).

[0114] As can be seen from Table 4, the high-performance glass fiber filter materials obtained by applying the organosilicon / polyurethane / epoxy resin composite emulsions of Examples 7-12 of this invention to glass fiber base paper, after pleating, exhibit tensile strength and retention rates that reach or even exceed those of the (water-soluble thermosetting acrylic resin) type glass fiber filter material described in Comparative Example 9. Example 8 achieved a retention rate of 64.94%. This is because polyethylene glycol, as a toughening segment, effectively improves the toughness of the resin-reinforced glass fiber filter material. When the glass fiber filter material is bent, it can disperse stress, thereby effectively inhibiting crack propagation and reducing the degree of breakage of fine fibers; and Comparative Example 8... In comparison, the high-performance glass fiber filter material obtained by applying the silicone / polyurethane / epoxy resin composite emulsion of the present invention to glass fiber base paper exhibits tensile strength and retention rate after pleating that is comparable to the high-performance glass fiber filter material of Comparative Example 8 (polyurethane / epoxy resin composite emulsion). This indicates that the tensile strength of the glass fiber filter material of the present invention is not affected by the amount of silicone resin used. Compared with Comparative Example 10, the high-performance glass fiber filter material obtained by applying the silicone / polyurethane / epoxy resin composite emulsion of the present invention to glass fiber base paper exhibits significantly better tensile strength and retention rate after pleating than the high-performance glass fiber filter material of Comparative Example 10 (commercially available waterborne epoxy resin).

[0115] Test Example 2

[0116] High-temperature resistance performance of high-performance glass fiber filter media for lubricating oil filtration obtained in Examples 7-12 and Comparative Examples 8-10 was determined.

[0117] The high-performance glass fiber filter media for lubricating oil filtration prepared in Examples 7-12 and Comparative Examples 8-10 were tested. The glass fiber filter media before and after pleating were immersed in aviation lubricating oil at 220°C, and the tensile strength of the glass fiber filter media after impregnation in high-temperature lubricating oil was measured. The test results are shown in Table 5.

[0118] Table 5. Test results of high-temperature lubricating oil resistance of high-performance glass fiber filter media for lubricating oil filtration in each embodiment and comparative example.

[0119]

[0120] The performance of high-temperature resistant lubricating oil was evaluated as follows: glass fiber filter paper was immersed in aviation lubricating oil at 220°C for 48 hours, so that both sides could be fully exposed to the oil. After removal, the surface lubricating oil was gently wiped off with filter paper, and then the residual lubricating oil was washed off three times with petroleum ether. Finally, the oil was placed in an oven at 80°C and dried to constant weight before performance testing.

[0121] The tensile strength was determined in accordance with the national standard (GB / T 12914-2018) using a tensile strength tester (model: CE062, L&W, Sweden).

[0122] As shown in Table 5, the high-performance glass fiber filter materials obtained by applying the silicone / polyurethane / epoxy resin composite emulsions of Examples 7-12 of this invention to glass fiber base paper exhibit tensile strength and retention rates exceeding 90% before and after oil immersion, indicating excellent high-temperature oil resistance. Even after pleating, the glass fiber filter material still maintains a high tensile strength retention rate after high-temperature oil immersion, demonstrating that even after pleating, the filter material can maintain structural and strength stability after prolonged immersion in high-temperature oil. Compared to the high-performance glass fiber filter material of Comparative Example 8 (polyurethane / epoxy resin composite emulsion), the composite emulsion without added silicone resin shows a significant decrease in tensile strength and retention rate after oil immersion, with a retention rate of only 61.08%, indicating that the addition of silicone resin can effectively improve the high-temperature oil resistance of the glass fiber filter material. After pleating, the tensile strength of the glass fiber filter material further decreases after high-temperature oil immersion, failing to maintain structural and strength stability. Compared to the high-performance glass fiber filter material of the (water-soluble thermosetting acrylic resin) type described in Comparative Example 9, the tensile strength and retention rate before and after oil immersion are very low. Furthermore, after the pleated glass fiber filter material undergoes a high-temperature oil resistance test, its tensile strength and retention rate further decrease, indicating that the (water-soluble thermosetting acrylic resin) type high-performance glass fiber filter material cannot withstand a high-temperature oil environment of 220°C. Compared to the high-performance glass fiber filter material of the (commercially purchased pure water-based epoxy resin) type described in Comparative Example 10, its tensile strength and retention rate before and after oil immersion can reach a high level of over 90%, indicating excellent high-temperature oil resistance. However, after the pleated glass fiber filter material undergoes a high-temperature oil resistance test, its tensile strength retention rate is 0, indicating that the (commercially purchased pure water-based epoxy resin) type high-performance glass fiber filter material cannot maintain structural and strength stability after pleating and has been dispersed by the fluid medium in the high-temperature oil.

[0123] The above embodiments are merely preferred embodiments of the present invention and are only used to explain the present invention, not to limit the present invention. Any changes, substitutions, modifications, etc., made by those skilled in the art without departing from the spirit and essence of the present invention should be within the protection scope of the present invention.

Claims

1. A method for preparing an organosilicon / polyurethane / epoxy resin composite emulsion, comprising the following steps: I. In a reactor equipped with a stirring device, a condensing device, a nitrogen protection device, and a temperature control device, dehydrated polyethylene glycol, hydroxyl silicone oil, and a measured amount of diisocyanate are stirred evenly, and the mixture is heated to 70-80℃ at room temperature for 2-4 hours to prepare an organosilicon / polyurethane prepolymer. II. Add a measured amount of hydrophilic chain extender, heat to 75-85℃ and react for 1-3 hours to prepare a hydrophilic organosilicon / polyurethane prepolymer; III. Add measured amounts of epoxy resin and diluent, heat to 80-90℃ and react for 4-6 hours to prepare an organosilicon / polyurethane / epoxy resin composite resin system; IV. Cool to 40-50℃, add neutralizing agent, and stir well; V. Add deionized water to the reaction system while stirring at 800-3000 rpm to form a silicone / polyurethane / epoxy resin composite emulsion; VI. Reduced pressure distillation to remove most of the diluent; The above steps yield the silicone / polyurethane / epoxy resin composite emulsion. In step I, the diisocyanate is an aliphatic or alicyclic isocyanate monomer containing two -NCO groups in its structure; the polyethylene glycol has a molecular weight range of 800 to 3000; and the total amount of polyethylene glycol and hydroxyl silicone oil is used in a molar ratio of 1:3 to 1:4 to the diisocyanate. In step II, the hydrophilic chain extender is a carboxylic acid or sulfonic acid type hydrophilic chain extender containing two -OH groups in its structure; the molar ratio of the hydrophilic chain extender to the diisocyanate is 1:3-1:7; In step III, the epoxy resin is a bisphenol A type or bisphenol F type epoxy resin having the following molecular structural formula: or in, The value range of n1 is 0.85-1.43, and the value range of n2 is 0.95-1.35; In step IV, the neutralizing agent is one or more of N,N-dimethylethanolamine, triethylamine, and sodium hydroxide, or in any proportion of two or more; the molar ratio of the neutralizing agent to the hydrophilic chain extender is 1.1:1-1.4:

1.

2. The method for preparing an organosilicon / polyurethane / epoxy resin composite emulsion according to claim 1, characterized in that, In step I, the molecular weight range of the hydroxyl silicone oil is 500 to 2000; the molar ratio of polyethylene glycol to hydroxyl silicone oil is 4:1 to 9:

1.

3. The method for preparing an organosilicon / polyurethane / epoxy resin composite emulsion according to claim 1, characterized in that, In step III, the mass ratio of epoxy resin to hydrophilic silicone / polyurethane prepolymer is 0.8:1-1.4:1; the diluent is methyl ethyl ketone (MEK), and the amount of diluent added is 40%-100% of the mass of epoxy resin.

4. An organosilicon / polyurethane / epoxy resin composite emulsion prepared by the preparation method according to any one of claims 1-3.

5. The application of the organosilicon / polyurethane / epoxy resin composite emulsion according to claim 4, characterized in that, The silicone / polyurethane / epoxy resin composite emulsion is applied to lubricating oil glass fiber filter materials and is prepared by a method including the following steps: I. The organosilicon / polyurethane / epoxy resin composite emulsion of claim 4 is diluted with deionized water, and a measured amount of aqueous curing agent is added to form a reinforced resin impregnation solution; II. The glass fiber base paper is impregnated in the above-mentioned reinforcing resin impregnation solution and dried in the range of 80-100°C to form glass fiber filter material, wherein the sizing amount of the reinforcing resin impregnation solution is 5.0±0.5% based on the weight of the glass fiber base paper; III. Pleat the above-mentioned glass fiber filter material to make a filter element, dry it, and cure it at 110-150℃ for 15-30 minutes.

6. The application of the organosilicon / polyurethane / epoxy resin composite emulsion according to claim 5, characterized in that, The waterborne curing agent is one of waterborne polyamide curing agent or waterborne polyetheramine curing agent; the silicone / polyurethane / epoxy resin composite emulsion and the waterborne curing agent are compounded according to the theoretical value that the epoxy equivalent is equal to the active hydrogen equivalent.

7. A high-performance glass fiber filter material for high-temperature lubricating oil filtration, characterized in that, It is prepared by a method including the following steps: I. The organosilicon / polyurethane / epoxy resin composite emulsion of claim 4 is diluted with deionized water, and a measured amount of aqueous curing agent is added to form a reinforced resin impregnation solution; II. The glass fiber base paper is impregnated in the above-mentioned reinforcing resin impregnation solution and dried in the range of 80-100°C to form glass fiber filter material, wherein the sizing amount of the reinforcing resin impregnation solution is 5.0±0.5% based on the weight of the glass fiber base paper; III. Pleat the above-mentioned glass fiber filter material to make a filter element, dry it, and cure it at 110-150℃ for 15-30 minutes.

8. The high-performance glass fiber filter material for high-temperature lubricating oil filtration according to claim 7, characterized in that, The waterborne curing agent is one of waterborne polyamide curing agent or waterborne polyetheramine curing agent; the silicone / polyurethane / epoxy resin composite emulsion and the waterborne curing agent are compounded according to the theoretical value that the epoxy equivalent is equal to the active hydrogen equivalent.

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