Carbon fiber carbonization protective oil and preparation method thereof

Abstract

The application discloses a carbon fiber carbonization protective oil agent and a preparation method thereof, and relates to the technical field of novel inks. The carbon fiber carbonization protective oil agent comprises the following components by mass: base silicone oil 40-70 parts, high-temperature modifier 10-25 parts, thickening agent 3-12 parts, dispersing agent 2-8 parts, anti-ultraviolet oxidation agent 1-5 parts, surfactant 0.5-4 parts, coupling agent 0.3-3 parts and solvent 5-20 parts. The carbon fiber carbonization protective oil agent can more effectively inhibit the oxidation reaction of carbon fibers, slow down the decline trend of the strength and modulus of the carbon fibers under a high-temperature oxygen environment, and has a more remarkable antioxidation protection effect on the carbon fibers compared with the prior art. The anti-ultraviolet oxidation agent in the protective oil agent can better absorb ultraviolet light and convert the ultraviolet light into harmless heat energy, and under ultraviolet light irradiation, the anti-ultraviolet oxidation agent can slow down the performance deterioration trend of the carbon fibers, and has better durability under the ultraviolet light environment compared with the prior art.

Description

Technical Field

[0001] This invention relates to the field of novel ink technology, specifically to a carbon fiber carbonization protective oil and its preparation method. Background Technology

[0002] Carbon fiber has been widely used in many high-end fields such as aerospace, automotive manufacturing, and sporting goods due to its excellent mechanical properties, high temperature resistance, and lightweight yet high strength. However, the carbonization process is crucial yet extremely challenging in the production of carbon fiber.

[0003] The carbonization process of carbon fiber requires a high-temperature environment, during which the carbon fiber is highly susceptible to oxidation. An oxidation reaction occurs on the surface, leading not only to a significant decrease in fiber strength and modulus but also affecting its bonding performance with the matrix, thus reducing the final properties of the carbon fiber composite. Furthermore, high temperatures can cause irreversible changes to the surface structure of the carbon fiber, further impacting its performance in applications.

[0004] To address this issue, the industry typically employs several protective measures. One method involves introducing an inert gas, such as argon or helium, into the furnace during carbonization to isolate oxygen and prevent oxidation. However, this method has significant limitations; it only provides protection at the gaseous environment level and cannot directly form a stable and dense protective film on the carbon fiber surface, making it difficult to completely eliminate microscopic oxidation and erosion. Moreover, fluctuations in the inert gas supply or insufficient furnace sealing significantly increase the risk of oxidation.

[0005] Another common approach is to apply a surface coating to the carbon fiber precursor stage, using materials such as polyvinyl alcohol or polyacrylonitrile. However, these coating materials have poor high-temperature resistance and often decompose, carbonize, or even peel off rapidly during high-temperature carbonization, failing to provide effective protection throughout the entire carbonization cycle. Moreover, the decomposition products generated by these coatings at high temperatures may remain on the carbon fiber surface, affecting subsequent surface treatments and the quality of the composite material.

[0006] Given the shortcomings of existing technologies, it is particularly urgent to develop a carbon fiber carbonization protective oil that can adhere tightly to the carbon fiber surface, remain stable under high-temperature environments, and possess excellent antioxidant properties. This protective oil should form a dense, uniform protective film on the carbon fiber surface, effectively isolating oxygen from contact with the fiber, while not introducing harmful impurities or affecting subsequent processes. This ensures the stable performance of the carbon fiber during carbonization, improves the production quality and efficiency of carbon fiber, and meets the growing demand for high-performance carbon fiber materials from high-end manufacturing industries. Summary of the Invention

[0007] The present invention aims to provide a carbon fiber carbonization protective oil agent, which provides excellent antioxidant protection for carbon fibers in high-temperature environments through innovative formulation and process, and solves the problems of poor protection effect in the prior art.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a carbon fiber carbonization protective oil agent, comprising the following raw material components in parts by weight: 40-70 parts of base silicone oil, 10-25 parts of high-temperature modifier, 3-12 parts of thickener, 2-8 parts of dispersant, 1-5 parts of UV oxidant, 0.5-4 parts of surfactant, 0.3-3 parts of coupling agent, and 5-20 parts of solvent;

[0009] The UV oxidant is a compound represented by Formula 1:

[0010]

[0011] R1 is selected from: methyl, methoxy, phenyl, cyano.

[0012] Furthermore, the base silicone oil is selected from methylphenyl silicone oil with a viscosity range of 300-2000 cSt (25°C).

[0013] Furthermore, the high-temperature modifier is selected from thermoplastic polyimide PI2080.

[0014] Furthermore, the thickener is selected from fumed silica.

[0015] Furthermore, the dispersant is selected from: polyether-modified polysiloxane BYK-306.

[0016] Furthermore, the surfactant is selected from sodium dodecylbenzenesulfonate.

[0017] Furthermore, the coupling agent is selected from γ-aminopropyltriethoxysilane.

[0018] Furthermore, the solvent is selected from acetone or dimethyl sulfoxide.

[0019] Furthermore, the UV oxidant is selected from any one of the compounds shown in the following structures:

[0020]

[0021] A method for preparing a carbon fiber carbonization protective oil includes the following steps:

[0022] S1. Add the base silicone oil and solvent to the reaction vessel and stir and mix at 300-800 rpm for 10-20 minutes;

[0023] S2. Add the high-temperature modifier and thickener, heat to 50-80℃, and stir and mix at 300-500 rpm for 30-60 minutes;

[0024] S3. Add the dispersant, UV oxidant, surfactant and coupling agent in sequence, and stir and mix at 40-60℃ and 500-600 rpm for 1-2 hours;

[0025] S4. Homogenize the carbon fiber 2-3 times under a pressure of 10-25MPa to obtain a carbon fiber carbonization protective oil.

[0026] Furthermore, S3 is performed under a nitrogen atmosphere.

[0027] Furthermore, S1 is performed at room temperature.

[0028] A carbon fiber carbonization protective oil can be used in carbon fiber continuous and discontinuous fiber reinforced composite materials.

[0029] Furthermore, the hydroxyl groups in the aforementioned anti-UV oxidant molecule possess active hydrogen atoms, enabling them to actively capture free radicals generated under high-temperature conditions. The hydroxyl groups provide hydrogen atoms through homolytic cleavage, which combine with free radicals to form stable products, interrupting the free radical chain oxidation reaction. The conjugated structure in the molecule exhibits a strong absorption band in the ultraviolet region, effectively intercepting high-energy ultraviolet light that could trigger oxidation. After absorbing energy, electrons transition from the ground state to the excited state and convert light energy into harmless heat energy through internal conversion, preventing energy transfer to the carbon fiber surface and thus avoiding oxidation. The nitrogen atom enhances the electron delocalization capability, broadening the ultraviolet absorption range and increasing the extinction coefficient.

[0030] Through the synergistic effect of its components, the carbon fiber carbonization protective oil of this invention solves the technical problems of decreased strength and modulus and deteriorated bonding performance with the matrix caused by the easy oxidation of carbon fibers. Its synergistic mechanism is as follows: using methyl phenyl silicone oil as the base silicone oil, a continuous and flexible initial physical barrier is formed with the assistance of solvent acetone or dimethyl sulfoxide; the thickener fumed silica and the dispersant polyether-modified polysiloxane BYK-306 ensure that the system viscosity is suitable and uniformly dispersed; the surfactant sodium dodecylbenzenesulfonate optimizes wettability so that the film uniformly covers the micro-defects on the fiber surface; the high-temperature modifier thermoplastic polyimide PI2080 and methyl phenyl silicone oil synergistically construct a high-temperature resistant network to maintain the compactness of the film; the anti-UV oxidant captures free radicals through the active hydroxyl groups in the molecule and strongly absorbs ultraviolet light through the conjugated structure and converts it into heat energy; at the same time, the coupling agent γ-aminopropyltriethoxysilane enhances the chemical bonding of the film-fiber interface and prevents high-temperature peeling. Ultimately, through enhanced homogenization, a composite protective film is formed, achieving a synergistic effect of physical isolation and chemical inhibition, significantly reducing oxidation loss and meeting the needs of high-end manufacturing.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. Improved antioxidant properties: The carbon fiber carbonization protective oil of the present invention can more effectively inhibit the oxidation reaction of carbon fiber in a high-temperature and oxygen-rich environment, and slow down the decline in its strength and modulus. Compared with the prior art, the antioxidant protection effect on carbon fiber is more significant.

[0033] 2. Enhanced UV resistance: The UV oxidant in the protective oil can better absorb UV light and convert it into harmless heat energy. Under UV irradiation, it slows down the trend of carbon fiber performance degradation. Compared with existing technologies, it has better durability in UV environment.

[0034] 3. Improved stability of the protective film: Through the synergistic effect of each component, the formed protective film is more tightly bonded to the carbon fiber surface, and is less prone to peeling or structural damage at high temperatures, exhibiting more stable protective performance. Compared with existing technologies, the stability of the protective film during the high-temperature carbonization process is better. Attached Figure Description

[0035] Figure 1 This is the NMR spectrum of the UV oxidant 1 described in this invention. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely 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.

[0037] Preparation Example 1

[0038] Synthesis of UV oxidant 1:

[0039]

[0040] Under a nitrogen atmosphere, 15 g of starting material 1, 22.08 g of starting material 2, 15.94 g of potassium carbonate, 0.20 g of target carbon, 0.75 g of triphenylphosphine, and 200 g of toluene were added to the reaction system. After stirring until homogeneous, the mixture was heated to 110 °C and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered through a silica gel cake, evaporated to dryness, and subjected to silica gel column chromatography using a mixture of petroleum ether and ethyl acetate as eluent. After evaporation to dryness, 16.69 g of intermediate 1 was obtained. Mass spectrometry (M / Z-MS+H) + ): 498.

[0041]

[0042] Under a nitrogen atmosphere, 16.69 g of intermediate 1, 12.87 g of starting material 3, 9.62 g of potassium carbonate, 0.18 g of target carbon, 0.43 g of triphenylphosphine, and 200 g of toluene were added to the reaction system. After stirring until homogeneous, the mixture was heated to 110 °C and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, the mixture was filtered through a silica gel cake, evaporated to dryness, and subjected to silica gel column chromatography using a mixture of petroleum ether and ethyl acetate as eluent. After evaporation, 12.51 g of the UV oxidant 1 was obtained. Mass spectrometry (M / Z-MS+H) + ): 738. See MRI. Figure 1 .

[0043] Preparation Examples 2-4

[0044] Preparation Examples 2-4 sequentially prepared UV oxidant 2-UV oxidant 4, following the preparation method of Preparation Example 1, except that raw material 1 was replaced, while the rest remained the same as in Preparation Example 1. Specific structures of raw material 1, UV oxidant 2-UV oxidant 4, and mass spectrometry (M / Z-MS+H) are detailed. + The data is shown in Table 1.

[0045] Table 1.

[0046]

[0047] Example 1

[0048] Preparation of a carbon fiber carbonization protective oil:

[0049] 1. Raw material composition and specifications

[0050] Base silicone oil: Methylphenyl silicone oil (viscosity: 500 cSt, 25℃), dosage: 50 parts;

[0051] High-temperature modifier: thermoplastic polyimide PI2080, dosage: 15 parts;

[0052] Thickener: Fumed silica, 8 parts;

[0053] Dispersant: Polyether-modified polysiloxane BYK-306, 5 parts;

[0054] Anti-ultraviolet oxidant: Anti-ultraviolet oxidant 1 (synthesized from preparation example 1), in an amount of 3 parts;

[0055] Surfactant: Sodium dodecylbenzenesulfonate, 2 parts;

[0056] Coupling agent: γ-aminopropyltriethoxysilane, 1.5 parts;

[0057] Solvent: Acetone, 10 parts.

[0058] 2. Preparation steps

[0059] S1. Add 50 parts of methylphenyl silicone oil and 10 parts of acetone to a stainless steel reactor and mix at 500 rpm for 15 minutes at room temperature (25°C).

[0060] S2. Add 15 parts of thermoplastic polyimide PI2080 and 8 parts of fumed silica to the reactor, then heat to 65°C and mix at a stirring speed of 400 rpm for 45 minutes;

[0061] S3. Under a nitrogen atmosphere, add 5 parts of polyether-modified polysiloxane BYK-306, 3 parts of UV oxidant 1, 2 parts of sodium dodecylbenzenesulfonate and 1.5 parts of γ-aminopropyltriethoxysilane in sequence, keep the temperature at 50°C and mix at a stirring speed of 550 pm for 1.5 hours.

[0062] S4. Transfer the mixed system to a high-pressure homogenizer (pressure: 20MPa) and perform three cycles of homogenization (with a 5-minute cooling interval between each cycle) to finally obtain the carbon fiber carbonization protective oil agent.

[0063] Examples 2-4

[0064] The preparation of a carbon fiber carbonization protective oil agent is carried out by referring to the preparation method of Example 1, except that the anti-ultraviolet oxidant is replaced sequentially with anti-ultraviolet oxidant 2-anti-ultraviolet oxidant 4 prepared in Preparation Examples 2-4, and the rest is the same as in Example 1.

[0065] Comparative Example 1

[0066] The preparation of a carbon fiber carbonization protective oil agent is carried out according to the preparation method of Example 1, except that the anti-ultraviolet oxidant is replaced with comparative compound 1, and the rest is the same as in Example 1.

[0067] Comparative compound 1: CAS: 27676-62-6, is antioxidant 3114, which is a commonly used antioxidant in industry.

[0068] Comparative Example 2

[0069] The preparation of a carbon fiber carbonization protective oil agent is carried out according to the preparation method of Example 1, except that the anti-ultraviolet oxidant is replaced with comparative compound 2, and the rest is the same as in Example 1.

[0070] Comparative compound 2:

[0071] Comparative Example 3

[0072] The preparation of a carbon fiber carbonization protective oil agent is the same as in Example 1, except that the UV oxidizing agent is not added.

[0073] Comparative Example 4

[0074] The preparation of a carbon fiber carbonization protective oil agent is carried out by referring to the preparation method of Example 1, except that the mass fraction of the thickener is replaced with 0.5 parts, and the rest is the same as in Example 1.

[0075] Comparative Example 5

[0076] The preparation of a carbon fiber carbonization protective oil agent is carried out by referring to the preparation method of Example 1, except that the mass fraction of the dispersant is replaced with 15 parts, and the rest is the same as in Example 1.

[0077] Performance testing:

[0078] 1. Mechanical property testing: An oiling agent (a carbon fiber carbonization protective oiling agent prepared in the examples and comparative examples) was uniformly coated on the fiber surface (coating amount: 5±0.2wt%), followed by carbonization treatment. The carbonized fiber bundles were unidirectionally aligned and cured with epoxy resin to prepare test strips (size: 150×10×0.5mm). 3 Curing conditions: 120℃ / 2h, pressure 0.5MPa. Tensile strength test: Tensile strength was tested using a universal testing machine, referring to ASTM D3379 (monofilament tensile test). Data are shown in Table 2.

[0079] 2. Antioxidant Test: The carbon fiber carbonization protective oil prepared in the examples and comparative examples was stirred at 180°C and an oxygen concentration of 40 for 200 hours, and then its mechanical properties were tested. The data are shown in Table 2.

[0080] 3. Oxidation resistance test: The carbon fiber carbonization protective oil prepared in the examples and comparative examples was irradiated at 180℃ under a UV-A lamp for 200 hours with continuous stirring during irradiation, and then its mechanical properties were tested. The data are shown in Table 2.

[0081] Table 2.

[0082]

[0083]

[0084] The carbon fiber carbonization protective oil of this invention (Examples 1-4) exhibited significantly better stability than the comparative examples in terms of initial mechanical properties, oxidation resistance after high-temperature oxygen exposure, and oxidation resistance after UV irradiation. In contrast, the comparative examples showed significant performance degradation after oxidation resistance and oxidation resistance tests, especially in Comparative Example 3 (lacking an anti-UV oxidant). Overall, the examples demonstrated stronger tensile strength retention, highlighting the synergistic effect of the components in the formulation, while the performance fluctuations of the comparative examples emphasized the negative impact of missing or imbalanced proportions of key components.

[0085] 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 carbon fiber carbonization protective oil, characterized in that, The raw material composition includes the following components by weight: 40-70 parts base silicone oil, 10-25 parts high-temperature modifier, 3-12 parts thickener, 2-8 parts dispersant, 1-5 parts UV oxidant, 0.5-4 parts surfactant, 0.3-3 parts coupling agent, and 5-20 parts solvent; The UV oxidant is a compound represented by Formula 1: Formula 1; R1 is selected from: methyl, methoxy, phenyl, cyano; The base silicone oil is selected from methylphenyl silicone oil, with a viscosity range of 300-2000 cSt at 25°C; The high-temperature modifier is selected from: thermoplastic polyimide PI2080; The thickener is selected from: fumed silica; The dispersant is selected from: polyether-modified polysiloxane BYK-306; The surfactant is selected from: sodium dodecylbenzenesulfonate; The coupling agent is selected from: γ-aminopropyltriethoxysilane; The solvent is selected from acetone or dimethyl sulfoxide.

2. A method for preparing a carbon fiber carbonization protective oil agent as described in claim 1, characterized in that, Includes the following steps: S1. Add the base silicone oil and solvent to the reaction vessel and stir and mix at 300-800 rpm for 10-20 minutes; S2. Add the high-temperature modifier and thickener, heat to 50-80℃, and stir and mix at 300-500 rpm for 30-60 minutes; S3. Add the dispersant, UV oxidant, surfactant and coupling agent in sequence, and stir and mix at 40-60℃ and 500-600 rpm for 1-2 hours; S4. Homogenize the carbon fiber 2-3 times under a pressure of 10-25MPa to obtain a carbon fiber carbonization protective oil.

3. The method for preparing a carbon fiber carbonization protective oil agent according to claim 2, characterized in that, S3 is carried out under a nitrogen atmosphere.

4. The method for preparing a carbon fiber carbonization protective oil agent according to claim 2, characterized in that, S1 is performed at room temperature.

Images