Fluorine-containing release agent with self-healing performance and preparation method and application thereof

Abstract

The invention relates to the technical field of organic polymer auxiliaries, and particularly discloses a fluorine-containing release agent with self-healing performance and a preparation method and application thereof. The release agent is prepared from the following components in parts by weight: 1.0 to 10.0 parts of self-healing fluorine modified organic silicon resin, 0.1 to 2.5 parts of simethicone, 0.001 to 0.05 part of stabilizer and 86.0 to 99.0 parts of organic solvent, the self-healing fluorine modified organic silicon resin is prepared from hydroxyl-terminated polydimethylsiloxane dihydric alcohol, diisocyanate and fluorine modified amino silicone oil. The low surface tension and hydrophobic and oleophobic characteristics of the organic fluorine element are utilized, so that migration of dimethyl silicone oil and abrasion of the release agent are reduced. The organic silicone oil molecules containing active amino react with the organic silicone oil with the terminal isocyanate group to generate a large number of acyl semicarbazide bonds. A large number of hydrogen bonds can be formed among the acyl semicarbazide bonds, reversibility is achieved, and the release agent is endowed with good self-healing performance.

Description

Technical Field

[0001] The invention belongs to the technical field of organic polymer composite material additives, and particularly relates to a fluorine-containing release agent with self-healing properties, a preparation method and application thereof. Background Art

[0002] Mold release agents can be categorized as internal or external based on their application method. External release agents offer greater flexibility, allowing for the type and number of application times to be selected based on the desired product shape and the difficulty of demolding. Because release agents (often made of materials such as silicone or fluorine) have low surface tension, migrating to the product surface can cause surface contamination and hinder painting or other secondary processing. Therefore, for composite products requiring further surface finishing, release agents must adhere securely to the mold with minimal or no migration to the product surface.

[0003] In addition, during the molding process of composite materials, the mold coated with release agent will inevitably scratch the raw materials (carbon fiber cloth or prepreg, etc.) or the molded product, causing damage to the release agent layer. If the release agent layer cannot be repaired in time, the composite material will directly contact the mold at the damaged part of the release agent layer, causing local adhesion between the product and the mold, increasing the difficulty of demoulding or making it difficult to demould. For traditional release agents, manual re-application of release agent is often used to repair damaged release coatings. The manual re-application method is not only time-consuming and labor-intensive, but may also fail to solve the problem in a timely manner due to reasons such as the operator's inadequate inspection and inadequate repair.

[0004] In order to solve the problems existing in the prior art, it is necessary to provide a semi-permanent release agent that has low migration, self-healing properties and can be used multiple times. Summary of the Invention

[0005] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and provide a fluorine-containing release agent with self-healing properties, as well as a preparation method and application thereof. The release agent utilizes the primary amino group (-NH2) of amino silicone oil and the isocyanate group (-NCO) silicone oil to form a large number of multiple hydrogen bonds between the acylaminourea bonds and the urethane bonds, thereby giving the release agent good self-healing properties; a large number of organic fluorine atoms are introduced into the silicone oil network structure, and the organic fluorine side chain structure not only provides low surface energy and good demolding properties, but also inhibits the migration of methyl silicone oil and reduces the wear of the release agent.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention is to provide a fluorine-containing release agent with self-healing properties, the components of which include, by weight: 1.0 to 10.0 parts of a self-healing fluorine-modified silicone resin, 0.1 to 2.5 parts of dimethyl silicone oil, 0.001 to 0.05 parts of a stabilizer, and 86.0 to 99.0 parts of an organic solvent;

[0008] The preparation method of the self-healing fluorine-modified silicone resin comprises the following steps:

[0009] S1. Add hydroxy-terminated polydimethylsiloxane diol and diisocyanate in a molar ratio of 1:2 to 2.1, add 0.001% to 0.02% of the catalyst by weight, and react at 60° C. to 85° C. for 2.5 to 6 hours to obtain an intermediate product A;

[0010] S2, under the condition of room temperature to 60 ° C and stirring, add organic solvent and amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2-3 to calculate the amount of amino silicone oil); after stirring evenly, add the primary amine molar number (n -NH2 ) 40% to 70% of fluorinated acrylate monomer, and continue the reaction for 0.5 to 4 hours;

[0011] S3, under room temperature and stirring conditions, according to the -NCO and the remaining -NH2 functional groups are equal in molar number (n -NCO :n -NH2(剩余) =1:1) and add intermediate product A, stir, and react at room temperature for 0.5h to 3h to obtain the product.

[0012] Furthermore, the structural formula of the hydroxy-terminated polydimethylsiloxane diol is Among them, 45≤a≤200.

[0013] Furthermore, the structural formula of the diisocyanate is

[0014] At least one of .

[0015] Furthermore, the structural formula of amino silicone oil is Among them, 1000≤m≤5×10 5 And m≥200(n+p), n and p are integers and p≥0.

[0016] Furthermore, the organic solvent is at least one of heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tridecane, tetradecane, solvent oil D28, solvent oil D30, and petroleum ether (60-90).

[0017] Furthermore, the catalyst is at least one of dibutyltin dilaurate, stannous octoate, organic bismuth, pentamethyldiethylenetriamine, and dimethylcyclohexylamine.

[0018] Furthermore, the fluorine-containing acrylate is at least one of trifluoroethyl acrylate, pentafluoropropyl acrylate, hexafluorobutyl acrylate, heptafluorobutyl acrylate, dodecafluoroheptyl acrylate, tridecafluorooctyl acrylate, and pentafluorooctyl acrylate.

[0019] Furthermore, the viscosity of the dimethyl silicone oil is 50 to 10,000 cps.

[0020] The second aspect of the present invention is to provide a method for preparing the above-mentioned release agent, wherein the preparation method comprises preparing the following components by weight: 1.0 to 10.0 parts of a self-healing fluorine-modified silicone resin, 0.1 to 2.5 parts of dimethyl silicone oil, 0.001 to 0.05 parts of a stabilizer, and 86.0 to 99.0 parts of an organic solvent;

[0021] The above components are mixed evenly at room temperature to obtain a semi-permanent release agent with low migration and self-healing properties.

[0022] The third aspect of the present invention is to provide the use of the above-mentioned release agent in preventing the material from adhering to the mold surface during the molding process.

[0023] A fourth aspect of the present invention is to provide a mold, the surface of which is coated with the above-mentioned release agent for use in demoulding molded products.

[0024] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0025] (1) The present invention provides a fluorine-containing mold release agent with self-healing properties and low migration. Organic fluorine atoms are introduced into the methyl silicone oil molecular chain through chemical bonds. After the organic silicone oil molecular chain containing fluorine atoms (containing -NH2) reacts with the terminal isocyanate silicone oil (containing -NCO), a three-dimensional network structure is formed, which reduces or eliminates the possibility of low-surface substances such as organic silicon and organic fluorine from contaminating the product.

[0026] (2) The surface tension of organic fluorine compounds (16-17 mN / m) is lower than that of silicone (22-24 mN / m) (and has hydrophobic and oleophobic properties), and they are more rigid. They will spontaneously migrate to the surface of the release agent, acting as a molecular isolation layer. This effectively inhibits the migration of low-viscosity dimethyl silicone oil from the inside of the release agent layer to the outside, reducing the contamination of the product by dimethyl silicone oil. In addition, at the microscopic level, the migrated organic fluorine atoms make the surface of the release layer uneven. This microstructure will further reduce the release force, reduce single-time wear, and increase the number of demolding times.

[0027] (3) The release agent provided by the present invention has self-healing properties. The amino silicone oil reacts with the isocyanate silicone oil to generate a large number of acyl semicarbazide bonds. A large number of multiple hydrogen bonds can be formed between the acyl semicarbazide bonds and the urethane bonds. These numerous hydrogen bonds are reversible, giving the release agent good self-healing properties.

[0028] (4) Dimethyl silicone oil has good compatibility with the self-healing network, and the hardness of the release layer can be flexibly adjusted by changing the dosage of dimethyl silicone oil, so that the release agent has a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the static contact angle of Example 1 and the comparative example sample;

[0030] Figure 2 This is an atomic force microscope photograph of the release layer obtained by spin coating in Example 1;

[0031] Figure 3 The self-healing time of Examples 1 to 6 and the DW977 release agent layer;

[0032] Figure 4 It is the average demolding times of Examples 1 to 6 and the DW977 release agent layer. DETAILED DESCRIPTION

[0033] To make the objects, technical solutions, and advantages of the present invention more apparent, the following describes the specific embodiments of the present invention in further detail with reference to the specific examples and accompanying drawings. Where specific test methods, instruments, or conditions are not specified in the examples, the methods or conditions described in the literature in the art or the product specifications were used. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0034] The present invention provides a method for preparing a fluorine-containing release agent with self-healing properties. The method comprises preparing the following components, in parts by weight: 1.0 to 10.0 parts of a self-healing fluorine-modified silicone resin, 0.1 to 2.5 parts of dimethyl silicone oil, 0.001 to 0.05 parts of a stabilizer, and 86.0 to 99.0 parts of an organic solvent; and uniformly mixing the above components at room temperature to obtain the release agent.

[0035] The preparation method of the self-healing fluorine-modified silicone resin comprises the following steps:

[0036] S1. Add hydroxy-terminated polydimethylsiloxane diol and diisocyanate in a molar ratio of 1:2 to 2.1, add 0.001% to 0.02% of the catalyst by weight, and react at 60° C. to 85° C. for 2.5 to 6 hours to obtain an intermediate product A;

[0037] S2, under the condition of room temperature to 60 ° C and stirring, add organic solvent and amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2-3 to calculate the amount of amino silicone oil to be added). After stirring evenly, add the primary amine molar number (n -NH2 ) 40% to 70% of fluorinated acrylate monomer, and continue the reaction for 0.5 to 4 hours;

[0038] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1 and add intermediate product A, stir, and react at room temperature for 0.5h~3h to obtain.

[0039] Among them, the structural formula of hydroxy-terminated polydimethylsiloxane diol is Where 45≤a≤200; the structural formula of diisocyanate is

[0040] At least one of; the structural formula of amino silicone oil is Among them, 1000≤m≤5×10 5 and m≥200(n+p), n and p are integers and p≥0; the organic solvent is at least one of heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tridecane, tetradecane, solvent oil D28, solvent oil D30, and petroleum ether (60-90); the catalyst is at least one of dibutyltin dilaurate, stannous octoate, organic bismuth, pentamethyldiethylenetriamine, and dimethylcyclohexylamine; the stabilizer is at least one of triisopropylphenyl phosphate, tributylphenyl phosphate, and triphenyl phosphate; the fluorine-containing acrylate is at least one of trifluoroethyl acrylate, pentafluoropropyl acrylate, hexafluorobutyl acrylate, heptafluorobutyl acrylate, dodecafluoroheptyl acrylate, tridecafluorooctyl acrylate, and pentafluorooctyl acrylate; and the viscosity of the dimethyl silicone oil is 50 to 10,000 cps.

[0041] The fluorine-containing release agent provided by the present invention can be prepared according to the above methods, which will be described below with reference to specific examples.

[0042] Example 1

[0043] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0044] S1. Add 0.0033 g (0.02%) of dibutyltin dilaurate to hydroxy-terminated polydimethylsiloxane diol (14.98 g, 1.0 mmol) and isophorone diisocyanate (0.47 g, 2.1 mmol) and react at 85°C for 6.0 h. Cool and filter to obtain intermediate product A.

[0045] S2, under the condition of mechanical stirring at room temperature, add 99.0g solvent oil D28 and 9.51g (5.04mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:3 to calculate the amount of amino silicone oil). After stirring evenly, 0.83 g (3.53 mmol) of hexafluorobutyl acrylate (70% by mole of primary amine in amino silicone oil) was added and the reaction was continued for 4 h.

[0046] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 11.68 g (1.512 mmol) of intermediate product A was added, stirred, and reacted at room temperature for 3 h to obtain a fluorine-modified self-healing silicone resin solution.

[0047] To the obtained 121.02 g fluorine-modified self-healing silicone resin solution, 2.503 g dimethyl silicone oil and 0.051 g triisopropylphenyl phosphate were added, and the mixture was mixed evenly under stirring to obtain the product.

[0048] Example 2

[0049] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0050] S1. Add 0.0017 g (0.01%) of stannous octoate to hydroxy-terminated polydimethylsiloxane diol (13.97 g, 4.0 mmol) and toluene diisocyanate (1.39 g, 8.0 mmol) and react at 75°C for 2.5 h. Cool and filter to obtain dimethylsiloxane with isocyanate groups at both ends (Intermediate Product A).

[0051] S2, under the condition of mechanical stirring at 40 ° C, add 36.05g solvent oil D30, 50.13g heptane and 0.95g (0.504mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2 to calculate the amount of amino silicone oil). After stirring evenly, 0.137 g (0.353 mmol) of dodecafluoroheptyl acrylate (70% by mole of primary amine in amino silicone oil) was added, and the reaction was continued for 0.5 h, and then the temperature was cooled to room temperature.

[0052] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 0.581 g (0.151 mmol) of intermediate product A was added, mechanically stirred, and reacted at room temperature for 0.5 h to obtain a fluorine-modified self-healing silicone resin solution.

[0053] To the obtained 87.85 g fluorine-modified self-healing silicone resin solution, 0.101 g of dimethyl silicone oil and 0.001 g of tributylphenyl phosphate were added, and the mixture was mixed evenly under stirring to obtain the product.

[0054] Example 3

[0055] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0056] S1. Add 0.0003 g (0.001%) of pentamethyldiethylenetriamine to hydroxy-terminated polydimethylsiloxane diol (25.12 g, 2.5 mmol) and diphenylmethane diisocyanate (1.07 g, 5.15 mmol) and react at 60°C for 5.0 h. Cool and filter to obtain dimethylsiloxane with isocyanate groups at both ends (Intermediate Product A).

[0057] S2, under the condition of mechanical stirring at 50 ° C, add 50.0g solvent oil D28, 40.0g petroleum ether and 6.67g (3.535mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2.5 (calculate the amount of amino silicone oil). After stirring evenly, 0.591 g (1.414 mmol) of tridecafluorooctyl acrylate (40% by mole of primary amine in amino silicone oil) was added, and the reaction was continued for 1.5 h, and then cooled to room temperature.

[0058] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 22.221 g (2.121 mmol) of intermediate product A was added, mechanically stirred, and reacted at room temperature for 2.5 h to obtain a fluorine-modified self-healing silicone resin solution.

[0059] To the obtained 119.47 g fluorine-modified self-healing silicone resin solution, 1.53 g dimethyl silicone oil and 0.033 g triphenyl phosphate were added, and the mixture was mixed evenly under stirring to obtain the product.

[0060] Example 4

[0061] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0062] S1. Add 0.0026 g (0.015%) of dimethylcyclohexylamine to hydroxy-terminated polydimethylsiloxane diol (15.11 g, 3.0 mmol), dicyclohexylmethane diisocyanate (0.79 g, 3.00 mmol), and 1,6-hexamethylene diisocyanate (0.51 g, 3.05 mmol). React at 70°C for 4.0 h. Cool and filter to obtain dimethylsiloxane with isocyanate groups at both ends (Intermediate Product A).

[0063] S2, under the condition of mechanical stirring at 45 ° C, add 37.0g undecane, 40.0g isooctane and 13.0g tetradecane, 10.05g (5.327mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2.8 (calculate the amount of amino silicone oil). After stirring evenly, 1.131 g (2.490 mmol) of pentadecafluorooctyl acrylate and 0.112 g (0.706 mmol) of trifluoroethyl acrylate (60% by mole of primary amine in the amino silicone oil) were added, and the reaction was continued for 1.5 h, and then the temperature was cooled to room temperature.

[0064] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 11.651 g (2.131 mmol) of intermediate product A was added, mechanically stirred, and reacted at room temperature for 1.5 h to obtain a fluorine-modified self-healing silicone resin solution.

[0065] To the obtained 111.70 g self-healing organic silicone resin solution, 1.5 g of dimethyl silicone oil, 0.005 g of triisopropylphenyl phosphate and 0.003 g of triphenyl phosphate were added, and the mixture was mixed evenly under stirring to obtain the product.

[0066] Example 5

[0067] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0068] S1. Hydroxyl-terminated polydimethylsiloxane diol (8.01 g, 1.0 mmol), hydroxyl-terminated polydimethylsiloxane diol (7.03 g, 2.0 mmol), isophorone diisocyanate (0.47 g, 2.1 mmol), and dicyclohexylmethane diisocyanate (1.06 g, 4.00 mmol) were added with 0.0017 g (0.01%) of organic bismuth and reacted at 75°C for 3.5 h. The mixture was cooled and filtered to obtain a dimethylsiloxane with isocyanate groups at both ends (intermediate product A).

[0069] S2, under the condition of mechanical stirring at 60 ° C, add 70.0g isononane, 15.0g dodecane, 10.0g tridecane and 11.19g (5.931mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2.2 (calculate the amount of amino silicone oil). After stirring evenly, 0.195 g (0.953 mmol) of pentafluoropropyl acrylate and 0.511 g (2.011 mmol) of heptafluorobutyl acrylate (50% by mole of primary amine in the amino silicone oil) were added, and the reaction was continued for 2.5 h, and then the temperature was cooled to room temperature.

[0070] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 16.38 g (2.965 mmol) of intermediate product A was added, mechanically stirred, and reacted at room temperature for 3 h to obtain a fluorine-modified self-healing silicone resin solution.

[0071] To the obtained 123.27 g self-healing organic silicone resin solution, 1.2 g of dimethyl silicone oil, 0.005 g of triisopropylphenyl phosphate and 0.005 g of tributylphenyl phosphate were added, and the mixture was mixed uniformly under stirring to obtain the product.

[0072] Example 6

[0073] This embodiment provides a method for preparing a fluorine-containing release agent with self-healing properties, which is as follows:

[0074] S1. Add 0.0011 g (0.003%) of dibutyltin dilaurate to hydroxyl-terminated polydimethylsiloxane diol (15.10 g, 1.0 mmol), hydroxyl-terminated polydimethylsiloxane diol (7.96 g, 1.0 mmol), hydroxyl-terminated polydimethylsiloxane diol (7.66 g, 2.2 mmol), toluene diisocyanate (0.70 g, 4.0 mmol), diphenylmethane diisocyanate (0.41 g, 1.60 mmol), and dicyclohexylmethane diisocyanate (0.80 g, 3.00 mmol), and react at 65°C for 5.0 h. Cool and filter to obtain a dimethylsiloxane with isocyanate groups at both ends (intermediate product A).

[0075] S2, under the condition of mechanical stirring at 30 ° C, add 30.0g decane, 56.0g dodecane and 9.48g (5.024mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2=1:2.7 (calculate the amount of amino silicone oil). After stirring evenly, 0.105 g (0.252 mmol) of tridecafluorooctyl acrylate, 0.335 g (1.317 mmol) of heptafluorobutyl acrylate, and 0.304 g (1.293 mmol) of hexafluorobutyl acrylate (55% by mole of primary amine in the amino silicone oil) were added, and the reaction was continued for 2.0 h.

[0076] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2(剩余) =1:1, and 17.56 g (2.261 mmol) of intermediate product A was added, mechanically stirred, and reacted at room temperature for 1.5 h to obtain a fluorine-modified self-healing silicone resin solution.

[0077] To the obtained 113.78 g self-healing organic silicone resin solution, 1.5 g of dimethyl silicone oil and 0.03 g of triisopropylphenyl phosphate were added, and the mixture was mixed evenly under stirring to obtain the product.

[0078] Comparative Example

[0079] S1. Add 0.0033 g (0.02%) of dibutyltin dilaurate to hydroxy-terminated polydimethylsiloxane diol (14.98 g, 1.0 mmol) and isophorone diisocyanate (0.47 g, 2.1 mmol) and react at 85°C for 6.0 h. Cool and filter to obtain intermediate product A.

[0080] S2, under the condition of mechanical stirring at room temperature, add 99.0g solvent oil D28 and 9.51g (5.04mmol) amino silicone oil (according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:3 to calculate the amount of amino silicone oil), and stir evenly.

[0081] S3, at room temperature and under stirring conditions, according to the molar number of functional groups n -NCO :n -NH2 =1:1, and 11.68 g (1.512 mmol) of intermediate product A was added, stirred, and reacted at room temperature for 3 h to obtain a self-healing silicone resin solution.

[0082] 2.503 g of dimethyl silicone oil and 0.051 g of triisopropylphenyl phosphate were added to 120.2 g of the obtained self-healing organic silicone resin solution, and the mixture was mixed evenly under stirring to obtain the product.

[0083] Performance testing and comparative experiments

[0084] (1) Migration performance

[0085] The n-hexane solution of Example 1 and the comparative example sample was dropped onto a 10mm×10mm glass sheet, and then spin-coated with a spinner to obtain a smooth release agent layer. The contact angle of distilled water on the surface of the coating agent layer was measured using a static contact angle meter. Each sample was tested three times and the average value was taken. The test results are shown in Figure 1 .

[0086] As shown in the figure, the contact angle of water in Example 1 is 120.7°, while the contact angle of water in the comparative example (Comparative Example 1) is 100.3°. This indicates that the release agent layer containing fluorine (Example 1 sample) exhibits lower surface tension. Analysis suggests that the fluorine element, which has a lower surface tension in its molecular structure, gradually migrates from the interior of the release agent to the surface, coating the release agent surface and causing the water contact angle to be significantly larger (by nearly 20°) than the sample without fluorine.

[0087] The n-hexane solution of Example 1 was spin-coated on a glass sheet to obtain a uniform thin layer of release agent. After natural drying, it was placed in a 60°C oven for 4 hours to completely evaporate the solvent. The surface morphology of the release agent layer was measured using an atomic force microscope (Tapping mode). Figure 2 As shown in the figure, on the surface of the release agent layer, the enriched fluorine atom side chains / side groups form protrusions with diameters ranging from tens to hundreds of nanometers and heights of approximately 7 to 10 nanometers. These hydrophobic and oleophobic nano-micro-protrusions (similar to the micro-convex structure on the surface of a lotus leaf) help further reduce the surface energy of the release agent and improve the release effect.

[0088] The spontaneous migration of fluorine from the interior of the release agent layer to the surface layer can also be demonstrated by the appearance of the release agent on the mold surface. Table 1 shows the appearance of the release agent layer after spraying Examples 1 to 6 and the comparative example samples on the mold surface (mold temperature 40-50°C) and the solvent has completely evaporated.

[0089] As shown in Table 1, the release agent layers obtained in Examples 1-6 were all opaque, while the coatings obtained in the comparative example were transparent. This indicates that the surface layer of the release agent is enriched with a high concentration of fluorine. This enriched fluorine occupies the position previously occupied by dimethylsiloxane, acting as a molecular barrier. This effectively inhibits the migration of low-viscosity dimethyl silicone oil from the interior of the release agent layer to the outside, reducing contamination of the product by the dimethyl silicone oil.

[0090] Table 1. Phenomenon of release agent on mold surface

[0091] Test samples Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example Appearance cream cream turbid cream turbid turbid transparent

[0092] To demonstrate that the introduction of organic fluorine into the organosilicon structure can reduce dimethoxysilane migration, a two-component polyester-polyurethane coating was directly sprayed onto the surfaces of composite products formed using molds cured using the samples from Examples 1-6 and the Comparative Example. The results are shown in Table 2. The composite products from Examples 1-6 produced smooth paint films after direct painting, indicating that the composite products were not contaminated by the low-surface-tension substance in the release agent. However, the composite product from the Comparative Example exhibited irregular localized shrinkage cavities after painting, indicating that dimethylsiloxane had migrated from the release agent layer to the composite product surface.

[0093] Table 2. Direct spraying of paint on composite surfaces

[0094]

[0095] (2) Self-healing performance

[0096] Pour Examples 1-6 and comparative sample DW977 into a polytetrafluoroethylene mold and dry in a 60°C forced air drying oven to constant weight. Carefully cut through the release agent coating layer with a knife (do not damage the mold surface). Observe the time required for the damaged area to completely heal at room temperature. The results are shown in Table 1. Figure 3 .

[0097] from Figure 3 The results show that compared to the comparative sample DW977, the release agents of Examples 1-6 exhibited superior self-healing properties at room temperature. A penetrating scratch on the release agent layer completely healed within 18 minutes at room temperature. However, the comparative sample DW977 did not fully heal within 60 minutes.

[0098] (3) Average demoulding times

[0099] For Examples 1-6 and the comparative sample DW977, three groups of molds were selected and the mold release agent was cured on the steel mold according to the normal construction process, and then the epoxy carbon fiber composite material was molded. The average demolding times of Examples 1-6 and the comparative samples are shown in FIG. Figure 3 shown.

[0100] from Figure 4 It can be seen that compared with the comparative sample DW977, the average demoulding times of the release agents of Examples 1 to 6 are significantly greater than that of the comparative sample DW977.

[0101] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fluorine-containing release agent with self-healing properties, characterized in that: The components thereof include, by weight: 1.0 to 10.0 parts of self-healing fluorine-modified organic silicone resin, 0.1 to 2.5 parts of dimethyl silicone oil, 0.001 to 0.05 parts of stabilizer, and 86.0 to 99.0 parts of organic solvent; The preparation method of the self-healing fluorine-modified silicone resin comprises the following steps: S1. Add hydroxy-terminated polydimethylsiloxane diol and diisocyanate in a molar ratio of 1:2 to 2.1, add 0.001% to 0.02% of the catalyst by weight, and react at 60° C. to 85° C. for 2.5 to 6 hours to obtain an intermediate product A; S2, under the condition of room temperature to 60 ℃ and stirring, add organic solvent and amino silicone oil, according to the molar number of -NCO and -NH2 functional groups n -NCO :n -NH2 =1:2-3 to calculate the amount of amino silicone oil; after stirring evenly, add fluorinated acrylate monomer with a primary amine molar number of 40%-70%, and continue the reaction for 0.5-4h, and the reaction temperature gradually returns to room temperature; S3. Under room temperature and stirring conditions, add the intermediate product A calculated according to the molar ratio of -NCO and the remaining -NH2 functional groups of 1:1, stir, and react at room temperature for 0.5h to 3h to obtain the product.

2. The fluorinated release agent according to claim 1, wherein The structural formula of the hydroxy-terminated polydimethylsiloxane diol is Among them, 45≤a≤200.

3. The fluorine-containing release agent according to claim 1, wherein The structural formula of the diisocyanate is At least one of .

4. The fluorine-containing release agent according to claim 1, wherein The structural formula of amino silicone oil is Among them, 1000≤m≤5×10 5 And m≥200(n+p), n and p are integers and p≥0.

5. The fluorinated release agent according to claim 1, wherein The organic solvent is at least one of heptane, isoheptane, octane, isooctane, nonane, isononane, decane, isodecane, undecane, dodecane, tridecane, tetradecane, solvent oil D28, solvent oil D30, and petroleum ether (60-90); the catalyst is at least one of dibutyltin dilaurate, stannous octoate, organic bismuth, pentamethyldiethylenetriamine, and dimethylcyclohexylamine; and the stabilizer is at least one of triisopropylphenyl phosphate, tributylphenyl phosphate, and triphenyl phosphate.

6. The fluorine-containing release agent according to claim 1, wherein The fluorine-containing acrylate is at least one of trifluoroethyl acrylate, pentafluoropropyl acrylate, hexafluorobutyl acrylate, heptafluorobutyl acrylate, dodecafluoroheptyl acrylate, tridecafluorooctyl acrylate, and pentafluorooctyl acrylate.

7. The fluorine-containing release agent according to claim 1, wherein The viscosity of the dimethyl silicone oil is 50 to 10,000 cps.

8. The method for preparing a fluorine-containing release agent according to any one of claims 1 to 7, wherein: The preparation method comprises the following components, calculated by weight: 1.0 to 10.0 parts of a self-healing fluorinated silicone resin, 0.1 to 2.5 parts of dimethyl silicone oil, 0.001 to 0.05 parts of a stabilizer, and 86.0 to 99.0 parts of an organic solvent; The above components are mixed evenly at room temperature to obtain the fluorine-containing semi-permanent release agent with self-healing properties.

9. Use of the fluorine-containing mold release agent according to any one of claims 1 to 7 in preventing a material from adhering to a mold surface during molding.

10. A mold, characterized in that: The surface of the mold is coated with a release agent according to any one of claims 1 to 7 for demoulding the molded product.

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