A thixotropic rust preventive oil composition and a method for producing the same

Abstract

This invention discloses a thixotropic rust-preventive oil composition and its preparation method, which has the following beneficial effects: (1) Excellent thixotropic properties: Polyamide wax forms a stable three-dimensional hydrogen bond network in the base oil, making the rust-preventive oil exhibit high viscosity and non-flowing state when stationary, while the viscosity decreases rapidly when subjected to shear, resulting in good workability. (2) Good storage stability: The thixotropic network structure formed by polyamide wax is stable and does not separate or precipitate during long-term storage. (3) Good compatibility with strong polar rust inhibitors: Polyamide wax is a physical thixotropic agent and does not rely on chemical reactions to form a network. Therefore, it has good compatibility with strong polar rust inhibitors such as alkaline barium dinonylnaphthalenesulfonate (T705) and is not prone to interference. (4) High transparency: Polyamide wax can form a semi-transparent gel-like product after dispersion in mineral oil, with an attractive appearance. (5) Simple process: It can be produced using the masterbatch method, which improves production efficiency and ensures batch stability.

Description

Technical Field

[0001] This invention relates to the field of metal rust prevention technology, specifically to a thixotropic rust-preventive oil composition and its preparation method. Background Technology

[0002] Rust-preventive oil is a commonly used protective material in the rust prevention treatment of metal products. It forms an oil film on the metal surface to isolate moisture and oxygen, preventing metal corrosion. Traditional rust-preventive oils usually have low viscosity. After being sprayed or brushed onto a vertical metal surface, they are prone to dripping due to gravity, resulting in uneven oil film distribution or even complete loss in some areas, creating rust-preventive blind spots.

[0003] To address the aforementioned problems, existing technologies employ methods that include adding thickeners or thixotropic agents, such as hydrogenated castor oil, fumed silica, or organobentonite, to the rust-preventive oil. For instance, Chinese patent application CN202211608269.9 discloses a long-lasting thixotropic rust-preventive oil composition, in which the thixotropic agent is selected from hydrogenated castor oil, fumed silica, or organobentonite.

[0004] However, the existing technology still has the following problems: (1) Hydrogenated castor oil is prone to coarsening during storage, which leads to the stratification and precipitation of rust-preventive oil; (2) After the addition of fumed silica, the rust-preventive oil turns white and is sensitive to moisture; (3) Organic bentonite has low thixotropic efficiency and requires a high addition amount to achieve the desired effect; (4) Existing thixotropic agents are not compatible with strong polar rust inhibitors (such as basic dinonylnaphthalenesulfonate barium), which can easily interfere with the formation of thixotropic networks. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a thixotropic rust-inhibiting oil composition and its preparation method that are stable in storage, have excellent thixotropic properties, and are compatible with sulfonate rust inhibitors. This invention can solve the deficiencies of existing thixotropic rust-inhibiting oils in terms of storage stability, compatibility with strong polar rust inhibitors, and appearance transparency.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, the present invention provides the following first aspect of the technical solution: a thixotropic rust-preventive oil composition, comprising a base oil, a rust inhibitor, and a thixotropic agent, wherein the thixotropic agent is polyamide wax, and the thixotropic rust-preventive oil composition comprises the following components in parts by weight: 70-95 parts of base oil; 5-15 parts of rust inhibitor; and 0.5-3 parts of polyamide wax.

[0009] Preferably, the polyamide wax is a polyamide thixotropic agent with an activation temperature between 65-85°C.

[0010] Preferably, the base oil is any one of paraffinic oil, naphthenic oil, or a mixture of both.

[0011] Preferably, the base oil is a mixture of paraffinic base oil and naphthenic base oil.

[0012] Preferably, the rust inhibitor is a sulfonate rust inhibitor.

[0013] Preferably, the sulfonate rust inhibitor is basic dinonylnaphthalene sulfonate barium.

[0014] To solve the above-mentioned technical problems, the present invention provides the following second aspect of the technical solution: a method for preparing a thixotropic rust-preventive oil composition as described in the first aspect of the technical solution above, comprising the following steps:

[0015] (1) Heat the base oil to 65-90℃;

[0016] (2) Add rust inhibitor and stir for 15 minutes to dissolve it completely;

[0017] (3) Add polyamide wax in batches, keep the oil temperature at 75-90℃ and stir for 20-40 minutes under high-speed dispersion conditions to ensure that it is fully melted and dispersed;

[0018] (4) Stop heating and allow the mixture to cool naturally to room temperature under stirring conditions to obtain the thixotropic rust-preventive oil product.

[0019] Preferably, the heating temperature in step (1) is 75-90℃.

[0020] Preferably, the fineness of the dispersed system in step (3) is less than 15 micrometers.

[0021] To solve the above-mentioned technical problems, the present invention provides the following third aspect of the technical solution: a high-concentration masterbatch, which is used to prepare a thixotropic rust-preventive oil composition as described in the first aspect of the technical solution above, comprising a base oil and 5-10% by weight of polyamide wax.

[0022] (III) Beneficial Effects

[0023] Compared with the prior art, the present invention provides a thixotropic rust-preventive oil composition and its preparation method, which has the following beneficial effects:

[0024] (1) Excellent thixotropic properties: Polyamide wax forms a stable three-dimensional hydrogen bond network in the base oil, which makes the rust-preventive oil exhibit high viscosity and non-flow when it is stationary, while the viscosity decreases rapidly when subjected to shear (such as brushing or spraying), resulting in good workability.

[0025] (2) Good storage stability: The thixotropic network structure formed by polyamide wax is stable and does not separate or precipitate during long-term storage.

[0026] (3) Good compatibility with strong polar rust inhibitors: Polyamide wax is a physical thixotropic agent and does not rely on chemical reactions to form a network. Therefore, it has good compatibility with strong polar rust inhibitors such as alkaline barium dinonylnaphthalenesulfonate (T705) and is not prone to interference.

[0027] (4) High transparency: Polyamide wax can form a semi-transparent gel-like product after being dispersed in mineral oil, with a beautiful appearance.

[0028] (5) Simple process: The pre-gel method (masterbatch method) can be used for production, which can improve production efficiency and ensure batch stability. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the steps of a method for preparing a thixotropic rust-preventive oil composition according to the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a thixotropic rust-preventive oil composition, which includes a base oil, a rust inhibitor, and a thixotropic agent. The thixotropic agent of this invention is polyamide wax. The thixotropic rust-preventive oil composition includes the following components in parts by weight: 70-95 parts base oil; 5-15 parts rust inhibitor; and 0.5-3 parts polyamide wax.

[0032] Preferably, the polyamide wax is a polyamide thixotropic agent with an activation temperature between 65-85°C.

[0033] Preferably, the base oil is a mixture of paraffinic base oil and naphthenic base oil, wherein the paraffinic base oil is a mineral base oil mainly composed of straight-chain / branched alkanes (paraffinic hydrocarbons); the naphthenic base oil content is 10-50% of the total weight of the base oil. The aforementioned naphthenic base oil is a base oil with naphthenic hydrocarbons as the main component. The paraffinic base oil and naphthenic base oil of the present invention are both prior art and will not be described in detail here.

[0034] The aforementioned rust inhibitor is preferably a sulfonate rust inhibitor. More preferably, the sulfonate rust inhibitor is the existing basic barium dinonylnaphthalenesulfonate (commonly known as: T705).

[0035] The present invention also provides a method for preparing a thixotropic rust-preventive oil composition, comprising the following steps:

[0036] (1) Heat the base oil to 65-90℃;

[0037] (2) Add rust inhibitor and stir for 15 minutes to dissolve it completely;

[0038] (3) Add polyamide wax in batches, keep the oil temperature at 75-90℃ and stir for 20-40 minutes under high-speed dispersion conditions to ensure that it is fully melted and dispersed;

[0039] (4) Stop heating and allow the mixture to cool naturally to room temperature under stirring conditions to form a thixotropic network and obtain a thixotropic rust-preventive oil product.

[0040] It is understood that the above preparation method of the present invention involves heating, activating, dispersing, and cooling polyamide wax in base oil to form a thixotropic network.

[0041] Example 1:

[0042] This embodiment provides a thixotropic rust-preventive oil composition, the components and their weight parts as follows:

[0043] Base oils: 60 parts paraffinic base oil and 20 parts naphthenic base oil (total 80 parts);

[0044] Rust inhibitor: 10 parts of alkaline barium dinonylnaphthalenesulfonate (T705);

[0045] Thixotropic agent: 1.0 part of polyamide wax (THIXATROL PLUS).

[0046] The preparation method of the above-mentioned thixotropic rust-preventive oil composition includes the following steps:

[0047] (1) Add the base oil to the reactor and heat it to 80°C;

[0048] (2) Add rust inhibitor and stir for 15 minutes to dissolve it completely;

[0049] (3) Add polyamide wax in five equal batches, keep the oil temperature at 80°C and turn on the high-speed disperser. Disperse at a speed of 2000-2500 rpm for 30 minutes. Use a scraper fineness meter to check that the fineness is less than 15 microns.

[0050] (4) Stop heating, keep stirring, and let it cool naturally to room temperature to form a thixotropic network and obtain a thixotropic rust-preventive oil product.

[0051] Performance testing: Centrifugal stability (3000 rpm / 30 min): No stratification, no precipitation; Appearance: Semi-transparent gel.

[0052] Example 2:

[0053] This second embodiment provides a thixotropic rust-preventive oil composition, the components and their weight parts as follows:

[0054] Base oils: 50 parts paraffinic base oil and 30 parts naphthenic base oil (total 80 parts);

[0055] Rust inhibitor: 10 parts of alkaline barium dinonylnaphthalenesulfonate (T705);

[0056] Thixotropic agent: 1.5 parts of polyamide wax (THIXATROL PLUS).

[0057] The preparation method of the above thixotropic rust-preventive oil composition is the same as that in Example 1 above.

[0058] Performance testing: Centrifugal stability: No stratification, no sedimentation; Appearance: Semi-transparent gel, completely non-flowing when stationary.

[0059] Example 3 (Masterbatch Method):

[0060] This embodiment three provides a method for preparing a thixotropic rust-preventive oil composition using a high-concentration masterbatch.

[0061] The preparation of high-concentration masterbatch includes the following steps: (1) heating 90 parts of naphthenic base oil to 80°C; (2) adding 10 parts of polyamide wax and dispersing at a constant temperature and high speed for 30 minutes until the fineness is less than 15 micrometers; (3) cooling naturally under stirring to obtain high-concentration masterbatch (polyamide wax content 10%).

[0062] The preparation of the rust-preventive oil composition includes the following steps: (1) Take 70 parts of base oil, 10 parts of T705, and 20 parts of the above high-concentration masterbatch (equivalent to 2 parts of polyamide wax); (2) Heat to 40-55℃ and stir evenly at a constant temperature; (3) Cool naturally to room temperature while stirring.

[0063] The performance test results are basically consistent with those of Example 1 above.

[0064] Comparative Example 1: Hydrogenated castor oil was used to replace polyamide wax at an addition rate of 1.2%, with the rest remaining the same as in Example 1 above. Test results: Centrifugal stability: Slight stratification occurred (approximately 5%); Appearance: Opaque, with a granular texture.

[0065] Comparative Example 2: Fumed silica (hydrophobic) was used to replace polyamide wax at a dosage of 1.5%, with the rest remaining the same as in Example 1 above. Test results: Centrifugal stability: no stratification; Appearance: milky white and opaque.

[0066] Comparative Example 3: Prepared using the direct addition method (without using the masterbatch method), but without stirring during cooling; otherwise, it was the same as Example 1 above. Test results: After cooling, obvious stratification occurred, with approximately 30% sedimentation at the bottom, failing to form a uniform thixotropic network.

[0067] Summary of Experimental Results

[0068] The test results of the above embodiments and comparative examples are summarized in Table 1 below:

[0069] Table 1 Summary of test results for the examples and comparative examples

[0070] Example 1 No layering translucent gel Example 2 No layering translucent gel Comparative Example 1 Slight stratification Opaque, grainy Comparative Example 2 No layering Milky white and opaque Comparative Example 3 Severe stratification Layering

[0071] The above experimental results show that the present invention, using polyamide wax as a thixotropic agent, is superior to or equivalent to the prior art in terms of thixotropic properties, storage stability, and appearance transparency, and exhibits good compatibility with basic barium dinonylnaphthalenesulfonate T705. Meanwhile, maintaining stirring during cooling is a key process condition for forming a stable thixotropic network.

[0072] It is understood that this invention discloses a thixotropic rust-preventive oil composition and its preparation method. The thixotropic rust-preventive oil composition comprises a base oil, a rust inhibitor, and a thixotropic agent, wherein the thixotropic agent is polyamide wax. The preparation method includes the steps of heating and activating the polyamide wax in the base oil, dispersing it, and cooling it to form a thixotropic network. This invention, by using polyamide wax as a thixotropic agent, enables the rust-preventive oil to have high viscosity and non-flowing properties when stationary, and its viscosity rapidly decreases under shear, facilitating application. It also exhibits good long-term storage stability and excellent rust-preventive performance.

[0073] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A thixotropic rust preventive oil composition comprising a base oil, a rust preventive agent, and a thixotropic agent, characterized in that: The thixotropic agent is a polyamide wax, and the thixotropic rust-preventive oil composition comprises the following components in parts by weight: 70-95 parts of the base oil; 5-15 parts of the rust inhibitor; The polyamide wax is 0.5 to 3 parts.

2. The thixotropic rust preventive oil composition according to claim 1, characterized by: The polyamide wax is a polyamide thixotropic agent with an activation temperature between 65-85℃.

3. The thixotropic rust preventive oil composition according to claim 1, characterized by: The base oil is any one of paraffinic oil, naphthenic oil, or a mixture of both.

4. The thixotropic rust preventive oil composition according to claim 3, characterized by: The base oil is a mixture of paraffinic base oil and naphthenic base oil.

5. The thixotropic rust preventive oil composition according to claim 1, characterized by: The rust inhibitor is a sulfonate rust inhibitor.

6. The thixotropic rust preventive oil composition according to claim 5, characterized by: The sulfonate rust inhibitor is alkaline dinonylnaphthalene sulfonate barium.

7. A process for the preparation of a thixotropic rust preventive oil composition as claimed in any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Heat the base oil to 65-90℃; (2) Add rust inhibitor and stir for 15 minutes to dissolve it completely; (3) Add polyamide wax in batches, keep the oil temperature at 75-90℃ and stir for 20-40 minutes under high-speed dispersion conditions to ensure that it is fully melted and dispersed; (4) Stop heating and allow the mixture to cool naturally to room temperature under stirring conditions to obtain the thixotropic rust-preventive oil product.

8. The method of claim 7, wherein: The heating temperature in step (1) is 75-90℃.

9. The method of claim 7, wherein: The fineness of the dispersed system in step (3) is less than 15 micrometers.

10. A high concentration masterbatch for the preparation of a thixotropic rust preventive oil composition as claimed in any one of claims 1 to 6, characterized in that: It includes base oil and 5-10% by weight of polyamide wax.

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