A coating composition, a grease coating and a preparation method and application thereof

Abstract

The application relates to the technical field of paint, and particularly discloses a paint composition, a grease paint and a preparation method and application thereof. The paint composition provided by the application comprises the following components by weight: polyacrylate 8-18 parts, dimethyl silicone oil 20-50 parts and styrene modified alkyd resin 5-10 parts; the weight average molecular weight of the dimethyl silicone oil is 3000-10000 Da; further, the weight average molecular weight of the dimethyl silicone oil is 5000-8000 Da; the application also provides a paint grease made of the above paint composition. The paint grease provided by the application has excellent flowability and bending resistance, and can be applied to substrates such as plastics, rubber and glass, so that good lubrication and protection can be achieved.

Description

Technical Field

[0001] This application relates to the field of coating technology, specifically to a coating composition, an oil-based coating, its preparation method and application. Background Technology

[0002] With the development of modern industry, the number of friction pairs in automated and mechanized products is increasing, and the requirements for friction reduction, wear resistance, and extended service life are becoming increasingly stringent. Lifetime lubrication is even required for precision parts in some optical equipment, precision instruments, and other electronic products. Grease is a viscous liquid or semi-solid substance that, when applied to or penetrating the surface of mechanical equipment, provides lubrication and protection.

[0003] Traditional greases are mostly perfluoropolyether greases. Perfluoropolyether greases are white greases made by thickening highly chemically stable perfluoropolyether oil with polytetrafluoroethylene and adding special anti-corrosion additives. Perfluoropolyether greases have high stability and good anti-wear properties, and are usually used as lubricants for long service cycles and harsh operating conditions. However, these greases have poor fluidity at room temperature and are mostly paste-like, resulting in poor uniformity when applied. Furthermore, when used on substrates such as plastics, rubber, and glass, the grease coating formed has poor bending resistance and is prone to breakage after bending. Summary of the Invention

[0004] In order to overcome the problems of uneven application and easy breakage of existing lubricating greases, and to obtain a grease coating with good fluidity and good bending resistance, this application provides a coating composition, a grease coating, a preparation method thereof, and its application.

[0005] In a first aspect, this application provides a coating composition, which adopts the following technical solution:

[0006] A coating composition comprising the following components by weight: 8-18 parts of polyacrylate, 20-50 parts of dimethyl silicone oil, and 5-10 parts of styrene-modified alkyd resin; wherein the dimethyl silicone oil has a weight-average molecular weight of 3000-10000 Da.

[0007] This application provides a coating composition made of polyacrylate, dimethyl silicone oil, and styrene-modified alkyd resin. This coating composition exhibits excellent flowability and flexural strength. When applied to the surfaces of plastic, rubber, and glass substrates, it provides excellent lubrication and protection. Dimethyl silicone oil possesses excellent viscosity-temperature properties and can operate within a temperature range of -70℃ to 180℃. This application uses dimethyl silicone oil with a weight-average molecular weight of 3000-10000 Da to prepare the grease coating, resulting in excellent lubrication properties. When applied to the substrate surface, it ensures the substrate remains in a free-sliding state. Polyacrylate imparts good flexural strength to the coating composition. Furthermore, the polyacrylate main chain does not contain double bonds, resulting in excellent resistance to thermal oxidation. Styrene-modified alkyd resin refers to a modified alkyd resin made using styrene monomer as a modifier, possessing good weather resistance, water resistance, and electrical insulation. Additionally, styrene-modified alkyd resin and polyacrylate have good miscibility, resulting in good uniformity of the coating composition and excellent flexural strength of the obtained coating.

[0008] In some embodiments, the polyacrylate may be in parts by weight of 8-10, 8-13, 8-15, 8-18, 10-13, 10-15, 10-18, 13-15, 13-18, or 15-18.

[0009] In some specific embodiments, the polyacrylate may be in the following weight proportions: 8 parts, 10 parts, 13 parts, 15 parts, or 18 parts.

[0010] In some embodiments, the dimethyl silicone oil may be in parts by weight of 20-30 parts, 20-40 parts, 30-40 parts, 30-50 parts, or 40-50 parts.

[0011] In some specific embodiments, the dimethyl silicone oil may be present in parts by weight of 20, 30, or 40.

[0012] Or 50 copies.

[0013] Optionally, the weight-average molecular weight of the dimethyl silicone oil is 5000-8000 Da.

[0014] Optionally, the coating composition comprises the following components by weight: 10-15 parts polyacrylate, 20-40 parts dimethyl silicone oil, and 5-10 parts styrene-modified alkyd resin.

[0015] Optionally, the polyacrylate is polymerized from acrylate monomers; the acrylate monomers are selected from one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, hexyl methacrylate, isobornyl methacrylate, trifluoroethyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, and octafluoropentyl methacrylate.

[0016] Optionally, the acrylate monomers are ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate; the molar ratio of ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate is 1:(0.2-0.4):(0.8-1.2).

[0017] In some embodiments, the molar ratio of ethyl acrylate, isobornyl methacrylate and hexafluorobutyl acrylate is 1:(0.2-0.3):1, 1:(0.2-0.4):1, 1:(0.2-0.5):1, 1:(0.3-0.4):1, 1:(0.3-0.5):1, 1:(0.4-0.5):1, 1:0.3:(0.5-0.8), 1:0.3:(0.5-1.2) or 1:0.3:(0.8-1.2).

[0018] In one specific embodiment, the molar ratio of ethyl acrylate, isobornyl methacrylate and hexafluorobutyl acrylate can be 1:0.2:1, 1:0.3:1, 1:0.4:1, 1:0.5:1, 1:0.3:0.5, 1:0.3:0.8 or 1:0.3:1.2.

[0019] In one specific embodiment, the acrylate monomers are methyl acrylate, ethyl methacrylate, and hexafluorobutyl acrylate in a molar ratio of 1:0.3:1.

[0020] In one specific embodiment, the acrylate monomers are ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl methacrylate in a molar ratio of 1:0.3:1.

[0021] Optionally, the coating composition further includes 0.3-0.8 parts of lubricant and 0.05-0.2 parts of antioxidant.

[0022] Secondly, this application provides a method for preparing polyacrylate.

[0023] A method for preparing polyacrylate includes the following steps: dissolving an initiator and an emulsifier in an alcohol solvent, and refluxing and heating to 50-70°C under stirring; maintaining the above reaction temperature, and then adding acrylate monomers dropwise to the reaction system, with the addition time controlled at 1.5-3 hours; after the addition is complete, continuing the reaction at the above temperature for 5-12 hours to obtain polyacrylate.

[0024] Optionally, the initiator is benzoyl peroxide or diisopropyl peroxide.

[0025] Optionally, the emulsifier is selected from nonylphenol polyoxyethylene ether, sodium diisooctyl sulfosuccinate, and sodium dodecyl sulfate.

[0026] Thirdly, this application provides an oil-based coating.

[0027] An oil-based coating, prepared using the coating composition.

[0028] This application utilizes a coating composition to prepare an oil coating. Applying the oil coating to the surface of a substrate can reduce the coefficient of friction of the substrate surface, thereby improving the lubricity and wear resistance of the substrate surface.

[0029] The preparation method of the above-mentioned grease coating includes the following steps: mixing polyacrylate, dimethyl silicone oil and styrene-modified alkyd resin evenly to obtain the grease coating.

[0030] Fourthly, the application of the coating compositions and grease coatings provided in this application on plastic substrates, rubber substrates, glass substrates or metal substrates.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. This application utilizes polyacrylate, dimethyl silicone oil, and styrene-modified alkyd resin to prepare a coating composition. By controlling the molecular weight of dimethyl silicone oil within the range of 3000-10000 Da, the obtained coating composition exhibits excellent uniformity, flowability, and bending resistance. Applying the grease coating made from the coating composition to the surface of a substrate ensures that the substrate is in a free-sliding state and improves the bending resistance of the substrate.

[0033] 2. In this application, ethyl acrylate, isobornyl methacrylate and hexafluorobutyl acrylate in a molar ratio of 1:(0.2-0.4):(0.8-1.2) are further selected as acrylate monomers, and the resulting polyacrylate has better bending resistance; the grease coating made from it can be used to coat the substrate to further improve the bending resistance of the substrate. Detailed Implementation

[0034] In a first aspect, this application provides a coating composition comprising the following components in parts by weight: 8-18 parts of polyacrylate, 20-50 parts of dimethyl silicone oil, 5-10 parts of styrene-modified alkyd resin, 0.3-0.8 parts of lubricant, and 0.05-0.2 parts of antioxidant; further, the coating composition comprises the following components in parts by weight: 10-15 parts of polyacrylate, 20-40 parts of dimethyl silicone oil, 5-10 parts of styrene-modified alkyd resin, 0.3-0.8 parts of lubricant, and 0.05-0.2 parts of antioxidant.

[0035] The dimethyl silicone oil has a weight-average molecular weight of 3000-10000 Da; further, the dimethyl silicone oil has a weight-average molecular weight of 5000-8000 Da.

[0036] In this application, the acrylate monomers are selected from one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, hexyl methacrylate, isobornyl methacrylate, trifluoroethyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, and octafluoropentyl methacrylate. Further, the acrylate monomers are ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate; the molar ratio of ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate is 1:(0.2-0.4):(0.8-1.2).

[0037] In this application, the preparation method of polyacrylate includes the following steps: dissolving an initiator and an emulsifier in an alcohol solvent, and refluxing and heating to 50-70°C under stirring; maintaining the above reaction temperature, and then adding acrylate monomers dropwise to the reaction system, with the addition time controlled at 1.5-3h; after the addition is completed, continuing the reaction at the above temperature for 5-12h to obtain polyacrylate.

[0038] Secondly, this application provides an oil-based coating prepared using a coating composition.

[0039] The preparation method of the above coating composition includes the following steps: mixing polyacrylate, dimethyl silicone oil and styrene-modified alkyd resin evenly to obtain an oil coating.

[0040] In this application, dimethyl silicone oil was purchased from Jining Tangyi Chemical Co., Ltd.; styrene-modified alkyd resin was purchased from Jining Sanshi Biotechnology Co., Ltd.; and other raw materials, reagents, solvents, etc., could be obtained commercially.

[0041] The following describes this application in further detail with reference to preparation examples, embodiments, and performance testing.

[0042] Preparation Examples 1-9

[0043] Preparation Examples 1-9 each provide a polyacrylate.

[0044] The difference in the above preparation examples lies in the monomers and ratios of the polyacrylate, as shown in Table 1 below.

[0045] The preparation method of the above polyacrylate includes the following steps: dissolving sodium dodecyl sulfate (2% of the total mass of monomers) and benzoyl peroxide (0.3% of the total mass of monomers) in ethanol, and refluxing and heating to 60°C under stirring; maintaining the above reaction temperature, and then adding acrylate monomers dropwise to the reaction system, controlling the dropwise addition time to 2 hours; after the dropwise addition is completed, continuing the reaction at the above temperature for 10 hours to obtain polyacrylate.

[0046] Table 1. Monomers and proportions of polyacrylates provided in Preparation Examples 1-9

[0047]

[0048]

[0049] Preparation Example 10

[0050] Preparation Example 10 provides a polyacrylate.

[0051] The difference in the above preparation examples is that the monomers of the polyacrylate are methyl acrylate, ethyl methacrylate and hexafluorobutyl acrylate in a molar ratio of 1:0.3:1.

[0052] Preparation Example 11

[0053] Preparation Example 11 provides a polyacrylate.

[0054] The difference in the above preparation example is that the monomers of the polyacrylate are ethyl acrylate, isobornyl methacrylate and hexafluorobutyl methacrylate in a molar ratio of 1:0.3:1.

[0055] Examples 1-11

[0056] Examples 1-11 each provide an oil-based coating.

[0057] The difference in the above embodiments is that the polyacrylate in the oil coatings is derived from Preparation Examples 1-11.

[0058] The preparation method of the grease coating provided in Examples 1-11 includes the following steps: 13g of polyacrylate, 30g of dimethyl silicone oil (weight average molecular weight of 3000-5000 Da) and 8g of styrene-modified alkyd resin are mixed evenly to obtain the grease coating.

[0059] Example 12

[0060] Example 12 provides an oil coating.

[0061] The difference between the above embodiment and Embodiment 2 is that the weight-average molecular weight of the dimethyl silicone oil in the grease coating is 5000-8000 Da.

[0062] Example 13

[0063] Example 13 provides an oil coating.

[0064] The difference between the above embodiment and Embodiment 2 is that the weight-average molecular weight of the dimethyl silicone oil in the grease coating is 8000-10000 Da.

[0065] Examples 14-20

[0066] Examples 14-20 each provide an oil-based coating.

[0067] The difference between the above embodiment and Embodiment 2 is that the amount of each component added to the oil coating is shown in Table 2 below.

[0068] Table 2 shows the addition amounts of each component in the oil coatings provided in Examples 2 and 14-20.

[0069]

[0070] Comparative Example 1

[0071] Comparative Example 1 provides an oil coating.

[0072] The difference between the above comparative example and Example 2 is that the weight-average molecular weight of the dimethyl silicone oil in the grease coating of Comparative Example 1 is 12000-15000 Da.

[0073] Comparative Example 2

[0074] Comparative Example 2 provides an oil coating.

[0075] The difference between the above comparative example and Example 2 is that the weight-average molecular weight of dimethyl silicone oil in the grease coating of Comparative Example 2 is 1000-2000 Da.

[0076] Comparative Example 3

[0077] Comparative Example 3 provides an oil-based coating.

[0078] The difference between the above comparative example and Example 2 is that the styrene-modified alkyd resin in the oil coating of Example 2 was replaced with acrylic-modified alkyd resin (purchased from Shandong Guangshen Electronic Technology Co., Ltd.).

[0079] Performance testing

[0080] The performance of the oil coatings obtained in Examples 1-20 and Comparative Examples 1-3 was tested, and the results are shown in Table 3 below.

[0081] (1) Viscosity: The viscosity of oil and coating was measured using an NDJ1 rotary viscometer.

[0082] (2) Bending resistance: A grease coating is applied to the surface of the optical fiber (3mm in diameter, 35mm in bending radius), and then the bending radius of the optical fiber is tested when it is bent and wound before and after coating. The bending radius of the optical fiber refers to the minimum bending radius allowed when the optical fiber is bent. The larger the radius, the better the bending resistance of the surface optical fiber.

[0083] Table 3 Performance test results of the oil coatings obtained in Examples 1-20 and Comparative Examples 1-3

[0084]

[0085] According to the test results in Table 3, the grease coatings prepared by polyacrylate, dimethyl silicone oil with a weight-average molecular weight of 3000-10000 Da, and styrene-modified alkyd resin in Examples 1-20 of this application have excellent flowability and bending resistance, with a viscosity of 1400-1900 mPa·s and a bending radius of 40-75 mm after coating the optical fiber. In contrast, the grease coating obtained by Comparative Example 1 using dimethyl silicone oil with a weight-average molecular weight of 12000-15000 Da has poor flowability and a viscosity as high as 2235 mPa·s. The grease coating prepared by Comparative Example 2 using dimethyl silicone oil with a weight-average molecular weight of 1000-2000 Da has good flowability, but it has no significant effect on improving the bending resistance of the optical fiber. The grease coating prepared by Comparative Example 3 using styrene-modified alkyd resin has poor flowability and a mediocre effect on improving the bending resistance of the optical fiber. Therefore, this application demonstrates that by using polyacrylate, dimethyl silicone oil, and styrene-modified alkyd resin to prepare grease coatings, and controlling the weight-average molecular weight of dimethyl silicone oil within the range of 3000-10000 Da, a grease coating with good flowability and uniformity can be obtained. When this grease coating is applied to a substrate, its excellent flowability can avoid damage to the substrate and allow the substrate to slide freely. In addition, this grease coating can also improve the bending resistance of the substrate, thereby achieving a protective effect on the substrate.

[0086] The test results of Examples 1-11 show that, in Examples 1-7, using ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate as acrylate monomers, the viscosity of the grease coating prepared was 1487-1641 mPa·s, and the bending radius of the optical fiber after coating was 56.8-71.0 mm; while in Example 8, using ethyl acrylate and isobornyl methacrylate as monomers for preparing polyacrylate, the bending radius of the optical fiber after coating was only 44.4 mm; in Example 9, using ethyl acrylate and hexafluorobutyl acrylate as monomers for preparing polyacrylate... The acrylate monomers used in Example 10 resulted in an optical fiber with a bending radius of only 42.8 mm after being coated with an grease coating. Example 10 used methyl acrylate, ethyl methacrylate, and hexafluorobutyl acrylate in a molar ratio of 1:0.3:1 as monomers to prepare polyacrylate, resulting in an optical fiber with a bending radius of only 48.2 mm after being coated with an grease coating. Example 11 used ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl methacrylate as monomers to prepare polyacrylate, resulting in an optical fiber with a bending radius of only 52.6 mm after being coated with an grease coating. Therefore, it is demonstrated that the polyacrylate prepared using ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate as acrylate monomers in this application exhibits good mechanical properties, and the grease coating prepared using these monomers demonstrates excellent bending resistance.

[0087] Further comparing the test results of Examples 1-7, Examples 1-3 and 6-7 further controlled the molar ratio of ethyl acrylate, isobornyl methacrylate and hexafluorobutyl acrylate in polyacrylate within the range of 1:(0.2-0.4):(0.8-1.2). The resulting grease coating had good bending resistance, and the bending radius of the optical fiber after coating reached more than 60 mm.

[0088] The test results of Examples 2, 12-13, and Comparative Examples 1-2 show that as the weight-average molecular weight of dimethyl silicone oil in the grease coating increases, the viscosity of the obtained grease coating gradually increases, and the bending radius of the optical fiber after coating also increases. Examples 2 and 12-13, by controlling the weight-average molecular weight of dimethyl silicone oil within the range of 3000-10000 Da, can obtain grease coatings with good flowability and excellent bending resistance. Furthermore, especially in Example 12, where the weight-average molecular weight of dimethyl silicone oil is controlled within the range of 5000-8000 Da, the overall performance of the obtained grease coating in terms of flowability and bending resistance is even more excellent.

[0089] The test results of Examples 2 and 14-20 show that the oil-based coatings obtained in Examples 2, 15-16, and 18-19 have better overall performance in terms of flowability and flexural strength than those obtained in Examples 14, 17, and 20. Therefore, considering economic costs, this application further controls the addition amount of each component in the coating composition within the following range: 10-15 parts of polyacrylate, 20-40 parts of dimethyl silicone oil, and 5-10 parts of styrene-modified alkyd resin, which can obtain an oil-based coating with even better overall performance in terms of flowability and flexural strength.

[0090] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A coating composition characterized in that, The coating composition comprises the following components by weight: polyacrylate 10-15 parts, dimethyl silicone oil 20-40 parts, and styrene-modified alkyd resin 5-10 parts. The polyacrylate is polymerized from acrylate monomers; the acrylate monomers are ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate; the mass ratio of the ethyl acrylate, isobornyl methacrylate, and hexafluorobutyl acrylate is 1: (0.2-0.4): (0.8-1.2).

2. The coating composition according to claim 1, characterized in that, The dimethyl silicone oil has a weight average molecular weight of 5000-8000 Da.

3. The coating composition of claim 1, wherein, The coating composition comprises the following components by weight: polyacrylate 10-15 parts, dimethyl silicone oil 20-40 parts, and styrene-modified alkyd resin 5-10 parts.

4. The coating composition of claim 1, wherein, The preparation method of the polyacrylate comprises the following steps: dissolving an initiator and an emulsifier in an alcohol solvent, and refluxing and heating to 50-70℃ under stirring; maintaining the above reaction temperature, then adding acrylate monomers dropwise into the reaction system, and controlling the dropwise adding time to be 1.5-3h; after the dropwise adding is completed, continuing the reaction at the above temperature for 5-12h to obtain the polyacrylate.

5. The coating composition according to any one of claims 1 to 4, characterized in that, The coating composition further comprises lubricant 0.3-0.8 parts and antioxidant 0.05-0.2 parts.

6. A method for producing an oil and fat coating, characterized by, The grease coating is prepared from the coating composition of any one of claims 1-5, and specifically comprises the following steps: uniformly mixing the polyacrylate, dimethyl silicone oil, and styrene-modified alkyd resin to obtain the grease coating.

7. Use of the coating composition of any one of claims 1-5 on a plastic substrate, a rubber substrate, a glass substrate, or a metal substrate.

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