Siloxane primer for bonding rubber and metal for cable joint as well as preparation method and application of siloxane primer

Abstract

The invention provides a siloxane primer for bonding rubber and metal for a cable joint as well as a preparation method and application of the siloxane primer. The siloxane primer is prepared from the following components in parts by weight: 10 to 16 parts of trimethoxy silane containing epoxy alkyl, 10 to 16 parts of trimethoxy silane containing aminoalkyl, 3 to 6 parts of a methylamine auxiliary agent, 3 to 8 parts of a phenol auxiliary agent, 3 to 6 parts of a stabilizer and 50 to 65 parts of an organic solvent. Trimethoxysilane containing epoxy alkyl in the primer forms a covalent bond with the metal surface through the epoxy alkyl, and forms a good bonding interface with silicon rubber at the silane group end. Trimethoxy silane containing aminoalkyl is subjected to chemical reaction with hydroxyl or other polar groups on the surface of metal through aminoalkyl, so that the adhesive force of the primer and the metal is enhanced. Therefore, the siloxane primer disclosed by the invention can be used for improving the bonding strength between the silicone rubber and the metal, so that the reliability of a cable joint is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adhesive, in particular to a siloxane primer for bonding rubber and metal for cable joints and a preparation method and application thereof. BACKGROUND

[0002] In the cable network of power systems, cable joints as the key components connecting cable lines directly affect the safe operation and service life of the entire power network. Especially in high-voltage power transmission systems, the quality of cable joints is crucial. In order to meet the needs of power facility maintenance and emergency repair, fast installation technology of high-voltage cable joints has emerged, which can complete the assembly and sealing of the joint in a short time, greatly reducing the power outage time and maintenance cost.

[0003] The core of fast installation of high-voltage cable joints lies in the effective bonding of conductive liquid silicone rubber and metal of the shielding tube. However, as a high-performance organosilicon polymer, the surface energy of silicone rubber is low, and direct bonding with metal often fails to achieve ideal strength and durability. In addition, the addition reaction curing mechanism of silicone rubber requires special environment and conditions, and traditional adhesive formulations contain components harmful to the curing process of silicone rubber, such as maleate and fumarate, which can interfere with the crosslinking reaction between silicone rubber molecules, thereby reducing its electrical properties and mechanical strength.

[0004] At present, the widely used adhesive formulations in industry mainly include phenolic resin type, isocyanate type and halogenated rubber type materials. Although these formulations perform well in some application fields, they have obvious limitations in the specific scenario of fast installation of high-voltage cable joints. First, different types of adhesives have different bonding effects between silicone rubber and different metals (such as steel and brass, etc.), and the same formulation can have a difference of more than 2N / mm in peel strength between steel or brass. Second, the viscosity of existing adhesive formulations is too high, which limits their applicability in different surface treatment processes such as dip coating, brushing or spraying, increasing the time and complexity of cable joint installation. In addition, some traditional adhesive formulations contain components that corrode metals, which can cause damage to metal parts over time, affecting the structural integrity and electrical properties of the cable joint. Or some adhesives damage the Si-O bond of silicone rubber, affecting its electrical properties. Therefore, it is urgent to develop an adhesive specifically applied to fast installation of high-voltage cable joints. SUMMARY

[0005] The main purpose of the present application is to provide a siloxane primer for bonding rubber and metal for cable joints and a preparation method and application thereof, to solve the problems of poor bonding strength and reliability between rubber and metal in cable joints in the prior art.

[0006] To achieve the above object, according to one aspect of the present application, there is provided a siloxane-based primer for bonding rubber and metal for cable joints, comprising, in parts by weight, 10 to 16 parts of a trimethoxysilane having an epoxyalkyl group, 10 to 16 parts of a trimethoxysilane having an aminoalkyl group, 3 to 6 parts of a methylamine-based auxiliary, 3 to 8 parts of a phenol-based auxiliary, 3 to 6 parts of a stabilizer, and 50 to 65 parts of an organic solvent.

[0007] Further, the siloxane-based primer comprises, in parts by weight, 12 to 16 parts of the trimethoxysilane having an epoxyalkyl group, 12 to 16 parts of the trimethoxysilane having an aminoalkyl group, 3.5 to 5.5 parts of the methylamine-based auxiliary, 4 to 6 parts of the phenol-based auxiliary, 3 to 5 parts of the stabilizer, and 52 to 62 parts of the organic solvent.

[0008] Further, the mass ratio of the trimethoxysilane having an epoxyalkyl group to the trimethoxysilane having an aminoalkyl group is 1 to 1.3:1.

[0009] Further, the trimethoxysilane having an epoxyalkyl group is 2,3-epoxypropyl trimethoxysilane and / or 3-(2,3-epoxycyclohexyl)ethyl trimethoxysilane; and / or, the trimethoxysilane having an aminoalkyl group is selected from any one or more of 2-aminoethyl-3-aminopropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, and N-phenyl-3-aminopropyl trimethoxysilane.

[0010] Further, the methylamine-based auxiliary is hexamethylenetetramine; and / or, the phenol-based auxiliary is m-dihydroxybenzene; and / or, the stabilizer is bis-[γ-(carboxysiloxy)propyl]tetrasulfide.

[0011] Further, the organic solvent is n-heptane and / or xylene, and when the organic solvent is n-heptane and xylene, the n-heptane is in a weight fraction of 20 to 30 parts, and the xylene is in a weight fraction of 30 to 35 parts.

[0012] According to another aspect of the present application, there is provided a preparation method of the above siloxane-based primer, comprising: step S1, sequentially mixing and reacting raw materials including the trimethoxysilane having an epoxyalkyl group, the trimethoxysilane having an aminoalkyl group, and a first organic solvent to obtain an intermediate product; and step S2, secondly mixing raw materials including the intermediate product, the methylamine-based auxiliary, the phenol-based auxiliary, the stabilizer, and a second organic solvent to obtain the siloxane-based primer.

[0013] Further, in the above step S1, the first organic solvent is xylene; and / or, the reaction is performed under the condition of water bath heating, the reaction temperature is 60 to 70°C, and the reaction time is 1 to 3 hours.

[0014] Further, in the step S2, the second organic solvent is n-heptane; and / or, the time for mixing the second is 2-3 hours.

[0015] According to another aspect of the present application, there is provided a use of a siloxane primer in a cable joint, the siloxane primer being used to bond rubber and metal in a shielding tube of the cable joint, the siloxane primer being the siloxane primer described above or prepared by the preparation method described above.

[0016] By using the technical solution of the present application, the siloxane primer with the components and contents described above can not only improve the bonding strength and reliability of the silicone rubber and metal in the cable joint, but also has the following advantages: 1) the siloxane primer of the present application is not compatible with the silicone rubber after curing, so as to not destroy the Si-O bond of the silicone rubber; 2) the siloxane primer does not contain maleate and fumarate and other substances that affect the crosslinking of liquid silicone rubber; 3) the siloxane primer does not include compounds containing Se, Te, As, Sb elements and halides, so the siloxane primer of the present application has good environmental protection; 4) the siloxane primer has low viscosity, which can meet various surface treatment processes such as dip coating, brushing and spraying; 5) the siloxane primer has good heat resistance and no corrosion to metal. Specifically, the epoxy alkyl-containing trimethoxysilane can form a covalent bond with the metal surface through its epoxy alkyl group, and form a good adhesive interface with the silicone rubber at the end of the silane group, thereby enhancing the bonding strength of the rubber and the metal. The trimethoxysilane containing amino alkyl can react with the hydroxyl group or other polar groups on the surface of the metal through the amino alkyl group, thereby enhancing the adhesion of the siloxane primer to the metal. The methylamine-based auxiliary can control the curing process of the siloxane primer, thereby improving the bonding efficiency, and also plays a certain crosslinking promotion role, thereby further improving the bonding effect between the rubber and the metal. The phenol-based auxiliary can improve the hygrothermal stability of the siloxane primer, protect the bonding surface from being damaged in a humid environment, and also help to improve the durability of the bonding. The stabilizer can prolong the effective storage period of the siloxane primer, avoid curing or performance degradation before use, and thus ensure that the siloxane primer can maintain its bonding performance after long-term storage. The organic solvent can dissolve the above raw materials and control the viscosity, thereby facilitating the coating of the siloxane primer on the surface of the substrate. In summary, the siloxane primer of the present application can improve the bonding strength between the silicone rubber and the metal, thereby improving the reliability and installation efficiency of the cable joint, and is suitable for high-voltage cable joints and other demanding scenarios. DETAILED DESCRIPTION

[0017] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0018] As analyzed in the background of the present application, the prior art has problems of poor bonding strength and reliability between rubber and metal in cable joints. In order to solve the above problems, the present application provides a siloxane primer for bonding rubber and metal in cable joints, and a preparation method and application thereof.

[0019] In a typical embodiment of the present application, a siloxane primer for bonding rubber and metal in cable joints is provided, which comprises, in parts by weight, 10-16 parts of a trimethoxysilane containing an epoxy alkyl group, 10-16 parts of a trimethoxysilane containing an amino alkyl group, 3-6 parts of a methylamine-based auxiliary, 3-8 parts of a phenol-based auxiliary, 3-6 parts of a stabilizer, and 50-65 parts of an organic solvent.

[0020] The siloxane primer of the present application with the above components and contents not only improves the bonding strength and reliability between silicone rubber and metal in cable joints, but also has the following advantages: 1) the siloxane primer of the present application is not compatible with silicone rubber after curing, thereby not damaging the Si-O bond of silicone rubber; 2) the siloxane primer does not contain maleate and fumarate and other substances that affect the crosslinking of liquid silicone rubber; 3) the siloxane primer does not include compounds containing Se, Te, As, Sb elements and halides, thus the siloxane primer of the present application has good environmental friendliness; 4) the siloxane primer has low viscosity, which can meet various surface treatment processes such as dip coating, brush coating and spraying; 5) the siloxane primer has good heat resistance and no corrosivity to metal. Specifically, the trimethoxysilane containing an epoxy alkyl group can form a covalent bond with the metal surface through its epoxy alkyl group, and form a good adhesive interface with silicone rubber at the end of the silane group, thereby enhancing the bonding strength between rubber and metal. The trimethoxysilane containing an amino alkyl group can chemically react with the hydroxyl group or other polar groups on the metal surface through the amino alkyl group, thereby enhancing the adhesion of the siloxane primer to the metal. The methylamine-based auxiliary can control the curing process of the siloxane primer, thereby improving the bonding efficiency, and also plays a certain crosslinking promotion role, thereby further improving the bonding effect between rubber and metal. The phenol-based auxiliary can improve the hygrothermal stability of the siloxane primer, protect the bonding surface from damage in a humid environment, and also help to improve the durability of the bonding. The stabilizer can prolong the effective storage period of the siloxane primer, avoid curing or performance degradation before use, and thus ensure that the siloxane primer still maintains its bonding performance after long-term storage. The organic solvent can dissolve the above raw materials and control the viscosity, thereby facilitating the coating of the siloxane primer on the substrate surface. In summary, the siloxane primer of the present application can improve the bonding strength between silicone rubber and metal, thereby improving the reliability and installation efficiency of the cable joint, and is suitable for harsh scenarios such as high-voltage cable joints.

[0021] In addition, the weight parts of the trimethoxysilane containing epoxy alkyl groups can be 10, 11, 12, 13, 14, 15, or 16 parts. The weight parts of the trimethoxysilane containing aminoalkyl groups can be 10, 11, 12, 13, 14, 15, or 16 parts. The weight parts of 3 to 6 parts of methylamine auxiliaries can be 3, 4, 5, or 6 parts. The weight parts of phenolic auxiliaries can be 3, 4, 5, 6, 7, or 8 parts. Of course, the weight parts of the above components can be any value within the above range.

[0022] To further improve the bonding strength and reliability between silicone rubber and metal in cable joints, the aforementioned siloxane primer, by weight, comprises: 12-16 parts of trimethoxysilane containing epoxy alkyl groups, 12-16 parts of trimethoxysilane containing amino alkyl groups, 3.5-5.5 parts of methylamine additives, 4-6 parts of phenolic additives, 3-5 parts of stabilizers, and 52-62 parts of organic solvents.

[0023] In one embodiment of this application, the mass ratio of trimethoxysilane containing alkyl epoxide to trimethoxysilane containing aminoalkyl epoxide is 1 to 1.3:1.

[0024] Preferably controlling the mass ratio of trimethoxysilane containing epoxy alkyl groups to trimethoxysilane containing amino alkyl groups within the above range helps the epoxy alkyl groups in the trimethoxysilane containing epoxy alkyl groups and the amino alkyl groups in the trimethoxysilane containing amino alkyl groups to work synergistically at different sites on the metal surface, forming a more complex three-dimensional cross-linked structure. This further enhances the adhesive strength and durability of the siloxane primer, thus facilitating its long-term stable operation in high-voltage cable joints.

[0025] In one embodiment of this application, the trimethoxysilane containing an epoxy alkyl group is selected from 2,3-epoxypropyltrimethoxysilane and / or 3-(2,3-epoxycyclohexyl)ethyltrimethoxysilane; and / or, the trimethoxysilane containing an aminoalkyl group is selected from any one or more of 2-aminoethyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane.

[0026] Preferably controlling the types of trimethoxysilanes containing epoxy alkyl groups and trimethoxysilanes containing amino alkyl groups within the above-mentioned range helps the epoxy alkyl groups in the trimethoxysilanes containing epoxy alkyl groups and the amino alkyl groups in the trimethoxysilanes containing amino alkyl groups to work synergistically at different sites on the metal surface, forming a more complex three-dimensional cross-linked structure, thereby further enhancing the adhesion strength and durability of siloxane primers.

[0027] In one embodiment of this application, the methylamine auxiliary is hexamethylenetetramine; and / or, the phenolic auxiliary is resorcinol; and / or, the stabilizer is bis-[γ-(carboxysilyl)propyl]tetrasulfide.

[0028] Preferred methylamine additives within the above-mentioned range help to better control the curing process of siloxane primers, thereby improving adhesion efficiency. They also help promote the crosslinking of the aforementioned components, further enhancing the adhesion between rubber and metal. Preferred phenolic additives within the above-mentioned range help to further improve the hygrothermal stability and adhesive durability of siloxane primers. Preferred stabilizers within the above-mentioned range help to extend the effective shelf life of siloxane primers, allowing them to maintain their adhesive properties even after prolonged storage.

[0029] In one embodiment of this application, the organic solvent is n-heptane and / or xylene. When the organic solvent is n-heptane and xylene, the weight parts of n-heptane are 20 to 30 parts and the weight parts of xylene are 30 to 35 parts.

[0030] Preferring the type of organic solvent and the weight proportions of n-heptane and xylene within the aforementioned ranges helps to ensure the uniform dispersion of other components in the organic solvent. This, in turn, better adjusts the viscosity of the siloxane primer, allowing it to uniformly cover the surface of the substrate and form a dense and homogeneous adhesive layer, thereby improving the bond strength between rubber and metal. Simultaneously, it also facilitates the rapid drying and curing of the siloxane primer after application.

[0031] In another typical embodiment of this application, a method for preparing the above-mentioned siloxane primer is provided. The preparation method includes: step S1, sequentially mixing and reacting raw materials including trimethoxysilane containing epoxy alkyl, trimethoxysilane containing amino alkyl and a first organic solvent to obtain an intermediate product; and step S2, mixing raw materials including the intermediate product, methylamine auxiliaries, phenolic auxiliaries, stabilizers and a second organic solvent to obtain the siloxane primer.

[0032] The siloxane primer prepared by the above-described method can improve the adhesion strength between silicone rubber and metal, thereby improving the reliability and installation efficiency of cable joints and making it suitable for harsh environments such as high-voltage cable joints. Specifically, step S1 allows trimethoxysilane containing epoxy alkyl groups and trimethoxysilane containing amino alkyl groups to be uniformly dispersed in the first organic solvent, which facilitates subsequent reactions and forms an intermediate product with enhanced adhesion properties. The active groups of the epoxy alkyl and amino alkyl trimethoxysilanes can chemically react with hydroxyl or other polar groups on the metal surface, thereby enhancing the adhesion between the siloxane primer and the metal. Step S2 ensures that the above components are thoroughly and uniformly mixed, resulting in a siloxane primer with uniform composition. Methylamine and phenolic additives improve the curing characteristics, hygrothermal stability, and application performance of the primer. In summary, the preparation method of this application is simple, easy to operate, and can achieve large-scale production and application.

[0033] In one embodiment of this application, in step S1 above, the first organic solvent is xylene; and / or, the reaction is carried out under water bath heating conditions, the reaction temperature is 60~70℃, and the reaction time is 1~3h.

[0034] Xylene is preferably used as the first organic solvent, as it helps to better disperse the epoxy-alkyl-containing trimethoxysilane and the aminoalkyl-containing trimethoxysilane in the first organic solvent, thereby facilitating subsequent reactions. The reaction is preferably carried out under water bath heating conditions, and controlling the reaction temperature and time within the aforementioned range helps to promote the reaction of the epoxy-alkyl-containing trimethoxysilane and the aminoalkyl-containing trimethoxysilane, thereby improving the homogeneity of the intermediate product and thus enhancing the adhesion between the metal and the silicone rubber.

[0035] In one embodiment of this application, in step S2 above, the second organic solvent is n-heptane; and / or, the second mixing time is 2-3 hours.

[0036] The second organic solvent is preferably n-heptane. Controlling the second mixing time within the above range helps to fully disperse the components in the second organic solvent, thereby obtaining a siloxane-based primer with uniform composition.

[0037] In another typical embodiment of this application, an application of a siloxane primer in a cable joint is provided. The siloxane primer is used to bond the rubber and metal inside the cable joint shielding tube. The siloxane primer is the siloxane primer described above or prepared by the preparation method described above.

[0038] When assembling high-voltage cable joints, the siloxane-based primer of this application can significantly enhance the bonding strength between the semi-conductive liquid silicone rubber shielding layer and the metal joint components, thereby improving the overall mechanical stability of the cable joint and effectively reducing electrical faults caused by poor bonding.

[0039] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0040] The preparation methods of Examples 1 to 3 and Comparative Examples 1 and 2 are the same, the difference lies in the formulation, the specific formulation is shown in Table 1.

[0041] Example 1

[0042] The alkyl-containing trimethoxysilane 2,3-epoxypropyltrimethoxysilane and the alkyl-containing trimethoxysilane 2-aminoethyl-3-aminopropyltrimethoxysilane were dispersed in xylene, a first organic solvent, for a first mixing. The mixture was then transferred to a three-necked flask equipped with a stirrer, condenser, and dropping funnel. A water bath was turned on, and the temperature was raised to 65°C for 1 hour to obtain an intermediate product. The intermediate product was then further mixed with hexamethylenetetramine (a methylamine additive), resorcinol (a phenolic additive), bis-[γ-(carboxysilyl)propyl]tetrasulfide (a stabilizer), and n-heptane (a second organic solvent) for a second mixing for 2 hours to obtain a siloxane-based primer.

[0043] Example 4

[0044] The difference from Example 1 is that the total weight of 2,3-epoxypropyltrimethoxysilane and 2-aminoethyl-3-aminopropyltrimethoxysilane is 28 parts, and the mass ratio of 2,3-epoxypropyltrimethoxysilane to 2-aminoethyl-3-aminopropyltrimethoxysilane is 1.3:1, thus obtaining a siloxane-based primer.

[0045] Example 5

[0046] The difference from Example 1 is that the total weight of 2,3-epoxypropyltrimethoxysilane and 2-aminoethyl-3-aminopropyltrimethoxysilane is 28 parts, and the mass ratio of 2,3-epoxypropyltrimethoxysilane to 2-aminoethyl-3-aminopropyltrimethoxysilane is 0.8:1, thus obtaining a siloxane-based primer.

[0047] Test method:

[0048] Bonding strength test: Place the metal sheet to be bonded in the test mold and apply liquid silicone rubber to the metal sheet. After curing, the metal sheet to be tested is obtained. Remove it from the test mold and test the bonding strength according to GB / T 11211-2009 "Adhesion strength between vulcanized rubber or thermoplastic rubber and metal". The test results are shown in Table 2.

[0049] Table 1

[0050]

[0051] Table 2

[0052]

[0053] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0054] The siloxane-based primer of this application, containing the above-mentioned components and contents, not only improves the bonding strength and reliability between silicone rubber and metal in cable joints, but also has the following advantages: 1) The siloxane-based primer of this application is immiscible with silicone rubber after curing, thus not damaging the Si-O bonds of silicone rubber; 2) The siloxane-based primer does not contain maleic acid esters and fumarate esters, which affect the crosslinking of liquid silicone rubber; 3) The siloxane-based primer does not contain compounds containing Se, Te, As, Sb elements, or halides, therefore, the siloxane-based primer of this application has good environmental friendliness; 4) The siloxane-based primer has low viscosity, which can meet various surface treatment processes such as dip coating, brush coating, and spray coating; 5) The siloxane-based primer has good heat resistance and is non-corrosive to metals. Specifically, trimethoxysilane containing epoxy alkyl groups can form covalent bonds with the metal surface through its epoxy alkyl groups, forming a good adhesive interface with silicone rubber at the silane group ends, thereby enhancing the bonding strength between rubber and metal. Trimethoxysilanes containing aminoalkyl groups enhance the adhesion between siloxane primers and metals by providing the aminoalkyl group to chemically react with hydroxyl groups or other polar groups on the metal surface. Methylamine additives regulate the curing process of siloxane primers, thereby improving adhesion efficiency and also promoting cross-linking, further enhancing the adhesion between rubber and metal. Phenolic additives improve the hygrothermal stability of siloxane primers, protecting the bonding surface from damage in humid environments and also contributing to improved adhesion durability. Stabilizers extend the shelf life of siloxane primers, preventing curing or performance degradation before use, thus ensuring that the siloxane primers maintain their adhesive properties even after long-term storage. Organic solvents dissolve the above raw materials and control viscosity, thus facilitating the coating of siloxane primers onto the substrate surface. In summary, the siloxane-based primer of this application can improve the bonding strength between silicone rubber and metal, thereby improving the reliability and installation efficiency of cable joints, and is suitable for demanding scenarios such as high-voltage cable joints.

[0055] The above are merely embodiments of the present invention and are not intended to limit the invention. Those skilled in the art will recognize that the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A siloxane-based primer for bonding rubber and metal in cable joints, characterized in that, The siloxane primer comprises, by weight parts: 10-16 parts of trimethoxysilane containing epoxy alkyl groups; 10-16 parts of trimethoxysilane containing aminoalkyl groups; 3-6 parts of methylamine adjuvants; 3-8 parts of phenolic additives; 3-6 parts of stabilizer; and 50-65 parts of organic solvent.

2. The siloxane primer according to claim 1, characterized in that, The siloxane primer comprises, by weight parts: 12 to 16 parts of the aforementioned trimethoxysilane containing epoxy alkyl groups; 12 to 16 parts of the aforementioned trimethoxysilane containing aminoalkyl groups; 3.5 to 5.5 parts of the methylamine adjuvant; 4 to 6 parts of the phenolic additive; 3 to 5 parts of the stabilizer; and 52 to 62 parts of the organic solvent.

3. The siloxane primer according to claim 1 or 2, characterized in that, The mass ratio of the trimethoxysilane containing epoxy alkyl groups to the trimethoxysilane containing amino alkyl groups is 1~1.3:

1.

4. The siloxane primer according to claim 1 or 2, characterized in that, The trimethoxysilane containing alkyl epoxides is 2,3-epoxypropyltrimethoxysilane and / or 3-(2,3-epoxycyclohexyl)ethyltrimethoxysilane; And / or, the aminoalkyl-containing trimethoxysilane is selected from any one or more of 2-aminoethyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane.

5. The siloxane primer according to claim 1 or 2, characterized in that, The methylamine auxiliaries are hexamethylenetetramine; and / or, the phenolic auxiliaries are resorcinol; and / or, the stabilizers are bis-[γ-(carboxysilyl)propyl]tetrasulfide.

6. The siloxane primer according to claim 1 or 2, characterized in that, The organic solvent is n-heptane and / or xylene. When the organic solvent is n-heptane and xylene, the weight parts of n-heptane are 20-30 parts and the weight parts of xylene are 30-35 parts.

7. A method for preparing a siloxane-based primer according to any one of claims 1 to 6, characterized in that, The preparation method includes: Step S1 involves sequentially mixing and reacting a raw material comprising an epoxy-alkyl trimethoxysilane, an aminoalkyl trimethoxysilane, and a first organic solvent to obtain an intermediate product; and Step S2 involves a second mixing of the raw materials, including the intermediate product, methylamine additives, phenolic additives, stabilizers, and a second organic solvent, to obtain the siloxane primer.

8. The preparation method according to claim 7, characterized in that, In step S1, the first organic solvent is xylene; and / or, the reaction is carried out under water bath heating conditions, the reaction temperature is 60~70℃, and the reaction time is 1~3h.

9. The preparation method according to claim 7 or 8, characterized in that, In step S2, the second organic solvent is n-heptane; and / or, the second mixing time is 2-3 hours.

10. The application of a siloxane-based primer in cable joints, wherein the siloxane-based primer is used to bond rubber and metal inside the shielding tube of the cable joint, characterized in that... The siloxane primer is the siloxane primer according to any one of claims 1 to 6 or is prepared by the preparation method according to any one of claims 7 to 9.

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