Aqueous high temperature resistant organic impregnation agent combined with nano silicon oxide and preparation method thereof

Abstract

The invention discloses a preparation method of an aqueous high-temperature-resistant organic impregnating agent combined with nano silicon oxide. The method comprises the following steps: adding a methacrylate monomer into a container, and then adding a stabilizer to obtain a methacrylate monomer solution for standby use; further adding a dispersant into the container, and then adding the nano silicon oxide, and stirring evenly at room temperature; continuously adding a binder and stirring evenly to obtain a mixture; then adding the mixture into the methacrylate monomer solution, and stirring evenly for standby use; before use, adding an initiator and a crosslinking agent into the mixture, and stirring at room temperature until the initiator and the crosslinking agent are completely dissolved to obtain an aqueous high-temperature-resistant organic impregnating agent combined with an inorganic phase; coating the nano silicon dioxide to improve its lipophilicity and dispersibility, and adding the binder to make the nano silicon dioxide and the organic monomer compatible, thereby overcoming the problem of poor compatibility between the organic phase and the inorganic phase; the obtained organic impregnating agent has low viscosity, good stability and high-temperature resistance.

Description

Technical Field

[0001] The invention relates to a high temperature resistant organic impregnating agent and a preparation method thereof, in particular to an aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide and a preparation method thereof. Background Art

[0002] Metal castings, weldments, powder metallurgy parts, etc. will produce varying degrees of sand holes, pores, and even cracks, micropores and other defects during the molding process. The existence of these defects will make the processed products fail to meet the design requirements in terms of mechanical properties, air tightness, corrosion resistance, etc., thus causing product scrapping. In particular, such defects are relatively hidden and often can only be discovered during later testing, causing great losses to production. By infiltrating such metal castings, weldments, powder metallurgy parts, etc., the infiltrant is infiltrated into the workpiece and fills its surface pores and other defects, which can improve the material's density, mechanical properties, air tightness and other properties to a certain extent. At the same time, such infiltrants can also be used for sealing non-metallic components and coatings with micropores.

[0003] Impregnants are mainly divided into inorganic impregnants and organic impregnants. Inorganic impregnants are represented by water glass, which has good high temperature resistance, but is difficult to clean, and has poor reliability and durability; organic impregnants mainly include unsaturated compound impregnants such as acrylates, epoxy resin impregnants, etc. Among them, acrylates are the most widely used. Organic impregnants have good reliability, but poor high temperature resistance.

[0004] Since the impregnant is used in mechanical products, its high temperature resistance is very important. In order to improve the high temperature resistance of acrylic impregnants, the invention patent with the publication number "CN106046266A" discloses a method for preparing a methacrylate impregnant containing epoxy monomers for metal castings. The thermal decomposition temperature of the impregnant disclosed in the invention is increased to 280°C, and it can generally be used at 220-230°C. The preparation process of the impregnant has many types of raw materials and the preparation process is relatively complicated. At the same time, the macromolecule increases the viscosity of the component impregnant, which has a certain adverse effect on its impregnation performance.

[0005] That is, the technical problem that the high temperature resistance of the organic penetrant in the prior art is poor, or although the high temperature resistance of the organic penetrant is improved, its most basic impregnation performance is adversely affected. Summary of the invention

[0006] In view of the poor high temperature resistance of existing organic impregnants, the present invention provides an aqueous high temperature resistant organic impregnant combined with an inorganic phase with strong high temperature resistance and good water solubility, and further provides a preparation method of the organic impregnant.

[0007] Furthermore, the inorganic phase combined with the organic infiltrant is nano silicon oxide.

[0008] The technical solution adopted by the present invention to solve the above technical problems is: a method for preparing an aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide, comprising the following steps, wherein the following parts are all calculated by mass:

[0009] (1) adding 1-100 parts of methacrylate monomer and 0-1 parts of stabilizer into a container, stirring at room temperature at a speed of 1-10 rpm for 10-100 seconds until the mixture is uniform, to obtain a methacrylate monomer solution for standby use;

[0010] (2) Add 0-10 parts of dispersant to the container, then add 0-5 parts of nano-silicon oxide, stir at room temperature at a speed of 1-10 rpm for 10-100 seconds until uniform; continue to add 0-1 parts of binder, stir at room temperature for 10-30 minutes until uniform;

[0011] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 1 to 10 rpm for 10 to 100 seconds until the mixture is uniform;

[0012] (4) Add 0.01-0.24 parts of an initiator and 0.2-0.4 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 1-10 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, to obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase.

[0013] A further preferred technical solution of the present invention is that the methacrylate monomer is one or more of methyl hydroxymethylacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate.

[0014] A further preferred technical solution of the present invention is: the stabilizer is one or more of p-hydroxyanisole and dimethyl benzophenone.

[0015] A further preferred technical solution of the present invention is that the dispersant is one or more of propylene glycol, dipropylene glycol and polyethylene glycol.

[0016] A further preferred technical solution of the present invention is: the binder is a silane coupling agent;

[0017] The silane coupling agent includes one or more of N-(piperazine ethyl)-3-aminopropylmethyldimethoxysilane, 3-diethylenetriaminopropylmethyldimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane.

[0018] A further preferred technical solution of the present invention is that the initiator is one or more of azobisisobutyronitrile, dimethyl azobisisobutyrate, azobisisoheptanenitrile, ammonium persulfate, potassium persulfate, isobutane hydroperoxide, and benzoyl peroxide.

[0019] A further preferred technical solution of the present invention is that the cross-linking agent is one or more of N,N-methylenebisacrylamide, N-hydroxymethylacrylamide, divinylbenzene and diacetone acrylamide.

[0020] A further preferred technical solution of the present invention is: in step (2), the size range of the nano silicon oxide is 5-20 nanometers.

[0021] Another preferred subject: an aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide, which is prepared by a preparation method of an aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide.

[0022] A further preferred technical solution of the present invention is that at 60-100° C., the time required for curing of the organic impregnating agent is 5-35 minutes.

[0023] A further preferred technical solution of the present invention is that at 320° C., the mass residual rate of the organic impregnation agent is 76%-85%.

[0024] Compared with the prior art, the advantages of the present invention are as follows: the present invention improves the lipophilicity and dispersibility of nano-silicon dioxide by coating it, and at the same time adds a binder to make the nano-silicon dioxide and the organic monomer compatible, thereby overcoming the problem of poor compatibility between the organic phase and the inorganic phase. The inorganic phase nano-silicon oxide is used to improve the high-temperature stability of the impregnant, and while ensuring that the impregnant has a low viscosity (making it easy to clean the workpiece and remove the residual impregnant on the surface), the prepared impregnant has good dimensional stability at high temperatures (high temperature resistance and good stability).

[0025] Specifically, the organic impregnating agent prepared by the present invention can achieve a mass residual rate of more than 80% at 320° C. In addition, the standard sealing ring treated with the organic impregnating agent prepared by the present invention can maintain a sealing grade of Class 1 at 320° C. for 10-20 minutes.

[0026] Furthermore, the present invention adopts hydroxyethyl methacrylate, which is a high-quality resin monomer that can self-polymerize and copolymerize, has low viscosity, good permeability, and is miscible with water; after curing, it is not easy to leave residual glue on the surface, so the residual liquid on the surface of the workpiece after impregnation can be easily cleaned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are only schematically representing the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0028] Figure 1 is the mass residual rate of the organic impregnating agent at 320° C. in Example 1;

[0029] Figure 2 is the mass residual rate of the organic impregnating agent at 320°C in Example 2;

[0030] Figure 3 is the mass residual rate of the organic impregnating agent at 320°C in Example 3;

[0031] Figure 4 is the mass residual rate of the organic impregnating agent at 320°C in Example 4;

[0032] Figure 5 is the mass residual rate of the organic impregnating agent at 320° C. in Example 5;

[0033] Figure 6 is the mass residual rate of the organic impregnating agent at 320° C. in Example 6;

[0034] Figure 7 It is the mass residual rate of the organic impregnating agent at 320°C in Example 7. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It will be appreciated by those skilled in the art that these descriptions are only illustrative and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0036] It should be noted that like reference numerals denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the terms "front", "rear", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0038] In the prior art, impregnants are mainly divided into organic and inorganic impregnants. Inorganic impregnants have good high temperature resistance, but their materials are alkaline and highly hygroscopic, resulting in poor durability. After impregnation, the workpiece cannot be washed with water, which makes it easy for glue residue to remain on the surface of the workpiece. Organic impregnants have good durability and stable sealing performance after curing, but poor high temperature resistance.

[0039] At present, the mainstream optimization method for organic impregnation agents is to increase the cross-linking degree of resin monomers and use resin monomers with better high-temperature performance. For example, the so-called multifunctional macromolecular monomer materials are used for compounding. On the one hand, the thermal stability and mechanical properties of the monomers after polymerization are improved, and on the other hand, the cross-linking degree is increased to improve the thermal stability and mechanical properties of the polymer itself. However, due to the characteristics of the polymer material itself, the improvement of thermal stability and other properties is limited, and its heat resistance is generally not as good as that of inorganic impregnation agents.

[0040] Based on the above problems, the present invention combines the organic phase and the inorganic phase to achieve the purpose of taking advantage of each other's strengths and making up for each other's weaknesses. In addition, based on the problem that the inorganic phase and the organic phase are difficult to dissolve each other, the present invention coats the nano-silicon dioxide to improve its lipophilicity and dispersibility, and adds a binder (modified silane) to make the nano-silicon dioxide and the organic monomer compatible, thereby overcoming the problem of poor compatibility between the organic phase and the inorganic phase. The specific embodiments are as follows:

[0041] Example 1:

[0042] (1) Add 100 parts of methacrylate monomer to a container, then add 0.025 parts of p-hydroxyanisole, stir at room temperature at a speed of 1 rev / sec, stir for 10-100 seconds until uniform, and obtain a methacrylate monomer solution for standby use. In this embodiment, the methacrylate monomer is 80 parts of hydroxyethyl methacrylate and 20 parts of methyl hydroxymethylacrylate. (2) Add 3 parts of dipropylene glycol to a container, then add 1.5 parts of nano-silicon oxide with a size of 5 nanometers, stir at room temperature at a speed of 1 rev / sec, stir for 10-100 seconds until uniform; continue to add 1 part of a binder, stir at room temperature for 10-30 minutes until uniform; in this embodiment, the binder is a silane coupling agent, and preferably, the silane coupling agent includes N-(piperazinylethyl)-3-aminopropylmethyldimethoxysilane.

[0043] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 1 rpm for 10-100 seconds until the mixture is uniform.

[0044] (4) Add 0.05 parts of an initiator and 0.25 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 1 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, and obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is azobisisobutyronitrile and the cross-linking agent is N,N-methylenebisacrylamide.

[0045] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 75°C and heat it for a certain period of time until it is completely polymerized and cured.

[0046] The organic impregnating agent prepared in this example takes 34 minutes to fully polymerize and cure.

[0047] like Figure 1 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this embodiment is 82.5%.

[0048] Embodiment 2

[0049] (1) Add 100 parts of methacrylate monomer and 0.025 parts of dimethyl benzophenone into a container, stir at 5 rpm for 10-100 seconds at room temperature until the mixture is uniform, and obtain a methacrylate monomer solution for later use. The methacrylate monomer in this embodiment is hydroxyethyl methacrylate.

[0050] (2) Add 4 parts of dipropylene glycol to the container, then add 2 parts of nano-silicon oxide with a size of 10 nanometers, stir at a speed of 5 rpm at room temperature, stir for 10-100 seconds until uniform; continue to add 1 part of a binder, stir at room temperature for 10-30 minutes until uniform. The binder in this embodiment is a silane coupling agent, preferably 3-diethylenetriaminepropylmethyldimethoxysilane.

[0051] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 5 rpm for 10-100 seconds until the mixture is uniform.

[0052] (4) Add 0.1 parts of an initiator and 0.1 parts of a crosslinking agent to the mixture obtained in step (3), stir at room temperature at a speed of 5 rpm for 10-100 seconds until the initiator and the crosslinking agent are completely dissolved, and obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is dimethyl azobisisobutyrate and the crosslinking agent is N-hydroxymethyl acrylamide.

[0053] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 75°C and heat it for a certain period of time until it is completely polymerized and cured.

[0054] The organic impregnating agent prepared in this example takes 18 minutes to fully polymerize and cure.

[0055] like Figure 2 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this embodiment is 81.7%.

[0056] Embodiment 3

[0057] (1) Add 100 parts of methacrylate monomer to a container, then add 0.02 parts of p-hydroxyanisole, stir at room temperature at a speed of 10 rpm, stir for 10-100 seconds until uniform, and obtain a methacrylate monomer solution for standby use. In this embodiment, the methacrylate monomer is 70 parts of hydroxyethyl methacrylate and 30 parts of hydroxypropyl methacrylate. (2) Add 4 parts of dipropylene glycol to a container, then add 2 parts of nano-silicon oxide with a size of 15 nanometers, stir at room temperature at a speed of 10 rpm, stir for 10-100 seconds until uniform; continue to add 0.5 parts of a binder, stir at room temperature for 10-30 minutes until uniform. In this embodiment, the binder is a silane coupling agent, preferably γ-glycidyloxypropyltrimethoxysilane.

[0058] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 10 rpm for 10-100 seconds until the mixture is uniform.

[0059] (4) Add 0.2 parts of an initiator and 0.2 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 10 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved to obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is azobisisoheptanonitrile and the cross-linking agent is divinylbenzene.

[0060] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 75°C and heat it for a certain period of time until it is completely polymerized and cured.

[0061] The organic impregnating agent prepared in this example takes 12 minutes to fully polymerize and cure.

[0062] like Figure 3 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this embodiment is 82.1%.

[0063] Embodiment 4

[0064] (1) Add 100 parts of methacrylate monomer to a container, then add 0.02 parts of dimethyl benzophenone, stir at 3 rpm at room temperature, stir for 10-100 seconds until uniform, and obtain a methacrylate monomer solution for standby use. In this embodiment, the methacrylate monomer is 80 parts of hydroxyethyl methacrylate and 20 parts of 2-hydroxybutyl methacrylate. (2) Add 4 parts of dipropylene glycol to a container, then add 2 parts of nano-silicon oxide with a size of 15 nanometers, stir at 3 rpm at room temperature, stir for 10-100 seconds until uniform; continue to add 1 part of a binder, stir at room temperature for 10-30 minutes until uniform. The binder in this embodiment is a silane coupling agent, preferably 3-diethylenetriaminepropylmethyldimethoxysilane.

[0065] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 3 rpm for 10-100 seconds until the mixture is uniform.

[0066] (4) Add 0.05 parts of an initiator and 0.2 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 3 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, to obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is ammonium persulfate and the cross-linking agent is diacetone acrylamide.

[0067] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 85°C and heat it for a certain period of time until it is completely polymerized and cured.

[0068] The organic impregnating agent prepared in this example takes 12 minutes to fully polymerize and cure.

[0069] like Figure 4 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this embodiment is 82.3%.

[0070] Embodiment 5

[0071] (1) Add 100 parts of methacrylate monomers and 0.02 parts of dimethylbenzophenone into a container, stir at 7 rpm for 10-100 seconds until the mixture is uniform, and obtain a methacrylate monomer solution for standby use. The methacrylate monomers in this embodiment are 60 parts of hydroxyethyl methacrylate, 10 parts of hydroxypropyl methacrylate, and 20 parts of methyl methacrylate.

[0072] (2) Add 2 parts of polyethylene glycol to the container, then add 1 part of nano-silicon oxide with a size of 20 nanometers, stir at a speed of 7 rpm at room temperature, stir for 10-100 seconds until uniform; continue to add 0.5 parts of a binder, stir at room temperature for 10-30 minutes until uniform. In this embodiment, the binder is a silane coupling agent, preferably γ-glycidyloxypropyltrimethoxysilane.

[0073] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 7 rpm for 10-100 seconds until the mixture is uniform;

[0074] (4) Add 0.4 parts of an initiator and 0.3 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 7 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, and obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is potassium persulfate and the cross-linking agent is divinylbenzene.

[0075] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 75°C and heat it for a certain period of time until it is completely polymerized and cured.

[0076] The organic impregnation agent prepared in this example takes 7 minutes to fully polymerize and solidify.

[0077] like Figure 5 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this example is 76.2%.

[0078] Embodiment 6

[0079] (1) Add 100 parts of methacrylate monomers into a container, then add 0.015 parts of p-hydroxyanisole, stir at room temperature at a speed of 9 rpm, stir for 10-100 seconds until uniform, and obtain a methacrylate monomer solution for standby use. The methacrylate monomers in this embodiment are 60 parts of hydroxyethyl methacrylate, 20 parts of hydroxypropyl methacrylate, and 10 parts of 2-hydroxybutyl methacrylate.

[0080] (2) Add 4 parts of dipropylene glycol to the container, then add 2 parts of nano-silicon oxide with a size of 20 nanometers, stir at a speed of 9 rpm at room temperature, stir for 10-100 seconds until uniform; continue to add 0.5 parts of a binder, stir at room temperature for 10-30 minutes until uniform. The binder in this embodiment is a silane coupling agent, preferably 3-diethylenetriaminepropylmethyldimethoxysilane.

[0081] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 9 rpm for 10-100 seconds until the mixture is uniform.

[0082] (4) Add 0.2 parts of an initiator and 0.3 parts of a cross-linking agent to the mixture obtained in step (3), stir at room temperature at a speed of 9 rpm for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, and obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is isobutylene hydroperoxide and the cross-linking agent is N,N-methylenebisacrylamide.

[0083] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 80°C and heat it for a certain period of time until it is completely polymerized and cured.

[0084] The organic impregnation agent prepared in this example takes 7 minutes to fully polymerize and solidify.

[0085] like Figure 6 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this embodiment is 76.9%.

[0086] Embodiment 7

[0087] (1) Add 100 parts of methacrylate monomers to a container, then add 0.025 parts of dimethyl benzophenone, stir at room temperature at a speed of 4 rpm for 10-100 seconds until uniform, to obtain a methacrylate monomer solution for standby use. In this embodiment, the methacrylate monomers are 70 parts of hydroxyethyl methacrylate, 20 parts of hydroxypropyl methacrylate and 10 parts of 2-hydroxybutyl methacrylate.

[0088] (2) Add 2 parts of propylene glycol to the container, then add 1 part of nano-silicon oxide with a size of 10 nanometers, stir at a speed of 4 rpm at room temperature, stir for 10-100 seconds until uniform; continue to add 0.5 parts of a binder, stir at room temperature for 10-30 minutes until uniform. In this embodiment, the binder is a silane coupling agent, preferably γ-glycidyloxypropyltrimethoxysilane.

[0089] (3) adding the mixture obtained in step (2) to the methacrylic acid monomer solution prepared in step (1), stirring at room temperature at a speed of 4 rpm for 10-100 seconds until the mixture is uniform.

[0090] (4) Add 0.1 parts of an initiator and 0.2 parts of a crosslinking agent to the mixture obtained in step (3), stir at room temperature at a speed of 4 rpm for 10-100 seconds until the initiator and the crosslinking agent are completely dissolved, and obtain an aqueous high temperature resistant organic impregnation agent combined with an inorganic phase. In this embodiment, the initiator is benzoyl peroxide and the crosslinking agent is divinylbenzene.

[0091] Pour the prepared organic impregnation agent into the glass test tube to 2 / 3 of the tube, and then place it in a constant temperature water bath at 90°C and heat it for a certain period of time until it is completely polymerized and solidified.

[0092] The organic impregnating agent prepared in this example takes 5 minutes to fully polymerize and solidify.

[0093] like Figure 7 As shown, at 320° C., the residual rate of the organic impregnating agent prepared in this example is 77.4%.

[0094] It should be noted that the residual rate mentioned in Examples 1 to 7 refers to the ratio of the remaining mass of the organic impregnating agent prepared in each example after high temperature (320° C.) to the initial mass. Preferably, the residual rate of each example of the present invention is measured by differential scanning calorimetry (DSC).

[0095] Through the above seven embodiments, it can be found that the organic impregnation agent prepared by the present invention has good stability at high temperature (high temperature resistance).

[0096] In addition, the standard sealing ring treated with the organic impregnant prepared by the present invention has a sealing grade of Class 1 after being kept at 320°C for 10-20 minutes. Specifically, the standard test ring containing 20% ​​pores is impregnated with the impregnant prepared by the present invention by a vacuum impregnation process. The impregnated sealing ring is kept at 320°C for 10-20 minutes, then returned to room temperature and placed in water. A leak test is performed according to US MIL-I-17563C to determine its grade. The sealing rings treated by the embodiments of the present invention still have a sealing grade of Class 1.

[0097] The reason why the embodiments of the present invention can have such excellent high temperature resistance and stability is that the present invention can effectively improve the lipophilicity and dispersibility of nano-silicon dioxide by coating it, and at the same time add a binder to make the nano-silicon dioxide and organic monomers compatible, thereby overcoming the problem of poor compatibility between the organic phase and the inorganic phase.

[0098] In addition, the high-temperature stability of the infiltrant is improved by using inorganic nano-silicon oxide, which ensures that the infiltrant has low viscosity (making the workpiece easy to clean and remove residual infiltrant on the surface) while also giving the prepared infiltrant good dimensional stability at high temperatures (high temperature resistance and good stability).

[0099] Furthermore, the present invention adopts hydroxyethyl methacrylate, which is a high-quality resin monomer that can self-polymerize and copolymerize, has low viscosity, good permeability, and is miscible with water; after curing, it is not easy to leave residual glue on the surface, so the residual liquid on the surface of the workpiece after impregnation can be easily cleaned off.

[0100] It should be further explained that the aqueous high-temperature resistant organic impregnant combined with nano silicon oxide prepared by the above embodiment can be used to infiltrate the workpiece using a general vacuum infiltration technology. That is, the impregnant obtained in this embodiment has strong applicability and does not require additional design of corresponding impregnation technical means; those skilled in the art can use conventional impregnation technology in the prior art for application according to actual needs. Specifically, the closed container containing the impregnant can be evacuated to below 0.01 Bar, and then the workpiece to be infiltrated can be immersed in the impregnation liquid, and the vacuum can be continued to be below 0.01 Bar; of course, the workpiece can also be directly immersed in the impregnant for vacuum treatment. Then release the pressure and wash the remaining impregnant on the surface of the workpiece with water, then place it in hot water at 90-95°C for 10 minutes to cure, and then take it out and cool it.

[0101] The above is a detailed introduction to the aqueous high temperature resistant organic impregnation agent combined with nano silicon oxide and its preparation method provided by the present invention. The principle and implementation mode of the present invention are described in detail using specific examples herein. The description of the above embodiments is only used to help understand the present invention and its core ideas. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified in a number of ways without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing an aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide, characterized in that The method comprises the following steps, and the following numbers are calculated by weight: (1) Add 1-100 parts of methacrylate monomer and 0-1 parts of stabilizer into a container, stir for 10-100 seconds at room temperature until the mixture is uniform, and obtain a methacrylate monomer solution for standby use; (2) Add 0-10 parts of dispersant to the container, then add 1-5 parts of nano-silicon oxide, stir for 10-100 seconds at room temperature until uniform; continue to add 0.5-1 parts of binder, stir for 10-30 minutes at room temperature until uniform; (3) adding the mixture obtained in step (2) to the methacrylate monomer solution prepared in step (1), and stirring at room temperature for 10-100 seconds until the mixture is uniform; (4) adding 0.01-0.24 parts of an initiator and 0.2-0.4 parts of a cross-linking agent to the mixture obtained in step (3), stirring at room temperature for 10-100 seconds until the initiator and the cross-linking agent are completely dissolved, thereby obtaining an aqueous high temperature resistant organic impregnation agent combined with nano-silicon oxide; The methacrylate monomer is one or more of methyl hydroxymethylacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate; The dispersant is one or more of propylene glycol, dipropylene glycol, and polyethylene glycol; The binder is a silane coupling agent; The silane coupling agent includes one or more of N-(piperazine ethyl)-3-aminopropylmethyldimethoxysilane, 3-diethylenetriaminopropylmethyldimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane; The crosslinking agent is one or more of N,N-methylenebisacrylamide, N-hydroxymethylacrylamide, divinylbenzene, and diacetone acrylamide; In step (2), the size of the nano silicon oxide is in the range of 5-20 nanometers.

2. The method for preparing the aqueous high temperature resistant organic impregnating agent combined with nano silicon oxide according to claim 1, characterized in that: The stabilizer is one or more of p-hydroxyanisole and dimethyl benzophenone.

3. The method for preparing the aqueous high temperature resistant organic impregnation agent combined with nano silicon oxide according to claim 1, characterized in that: The initiator is one or more of azobisisobutyronitrile, dimethyl azobisisobutyrate, azobisisoheptanenitrile, ammonium persulfate, potassium persulfate, isobutane hydroperoxide, and benzoyl peroxide.

4. A water-based high temperature resistant organic impregnation agent combined with nano silicon oxide, characterized in that: Prepared by the preparation method of any one of claims 1-3 of an aqueous high temperature resistant organic impregnation agent combined with nano silicon oxide; At 60-100°C, the time required for the curing of the organic impregnant is 5-35 minutes; At 320° C., the mass residual rate of the organic impregnating agent is 76%-85%.

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