Hydrophobic anti-icing pre-dipping glue solution and preparation method thereof as well as prepreg and preparation method thereof

Abstract

The invention relates to the field of preparation of composite prepregs, and provides a hydrophobic anti-icing pre-dipping glue solution and a preparation method thereof, and a prepreg and a preparation method thereof, the hydrophobic anti-icing pre-dipping glue solution comprises epoxy resin, organic silicon resin, a nano-scale filler I, a micron-scale filler II, a curing agent and a solvent; the nanoscale filler I is selected from any one of silicon oxide, zinc oxide and aluminum oxide; and the micron-sized filler II is stearic acid modified titanium oxide powder. The hydrophobic anti-icing pre-dipping glue solution is prepared, the anti-icing prepreg is obtained through curing molding, and the hydrophobicity and the anti-icing performance of the surface of a material can be improved.

Description

Technical Field

[0001] The invention relates to the field of composite material prepreg preparation, and in particular to a hydrophobic anti-icing prepreg glue solution and a preparation method thereof, a prepreg and a preparation method thereof. Background Art

[0002] High-performance composite materials based on carbon fiber composite materials are widely used in many fields of the national economy in modern industry due to their high strength, low weight and excellent performance. However, the epoxy resin, a resin matrix commonly used in composite materials, has a low contact angle with water (about 75°), which leads to poor anti-icing ability of carbon fiber composite materials prepared with epoxy resin as the base material. Industrial products prepared with this composite material, such as wind turbine blades, aircraft, railway trucks, etc., are difficult to remove after ice is formed in low temperature environments.

[0003] The existing technology mainly solves the problem of composite material icing through coating or heating. The coating solution generally requires spraying after the equipment is manufactured, which is labor-intensive and difficult to ensure the appearance; the heating method is difficult to modify existing equipment and is relatively energy-consuming. Summary of the invention

[0004] The invention prepares an anti-icing prepreg glue solution, which comprises epoxy resin, silicone resin, nano-scale filler I, micron-scale filler II, curing agent and solvent; the nano-scale filler I is selected from any one of silicon oxide, zinc oxide and aluminum oxide; the micron-scale filler II is titanium oxide powder modified by stearic acid.

[0005] As a preferred embodiment, the epoxy resin is a difunctional epoxy resin with a viscosity of 10000 to 2000 mPa.s at 25°C.

[0006] The epoxy resin is a bifunctional epoxy resin, which means that the epoxy resin contains at least two epoxy groups and has a viscosity of 10000 to 20000 mPa.s at 25°C.

[0007] As a preferred embodiment, the organic silicone resin is a methylphenyl silicone resin, and the molecular weight is not limited. Preferably, the molar content of phenyl in the methylphenyl silicone resin is ≥30%;

[0008] As a preferred embodiment, the curing agent is methyl etherified amino resin.

[0009] As a preferred embodiment, the solvent is a mixture of xylene and n-butanol, and the mass ratio of xylene to n-butanol is (3-5):(7:5).

[0010] As a preferred embodiment, the mass ratio of the nano-scale filler I to the micro-scale filler II is 1:10 to 10:1.

[0011] As a preferred embodiment, the particle size of the nano-scale filler I ranges from 100 to 200 nanometers.

[0012] As a preferred embodiment, the particle size of the micron-sized filler I is in the range of 5 to 10 μm.

[0013] As a preferred embodiment, the stearic acid-modified titanium oxide powder is obtained by mixing titanium oxide and an ethanol solution of stearic acid.

[0014] As a preferred embodiment, the preparation method of stearic acid modified titanium oxide powder is as follows: stearic acid is added to ethanol and stirred evenly to form a mixed solution, the mass concentration of stearic acid in the mixed solution is 5% to 10%, titanium oxide powder is added at a mass ratio of 2:1 to 5:1 of the mixed solution and titanium oxide, and the reaction is mechanically stirred at 30 to 35°C for 30 to 60 minutes. After the reaction is completed, centrifugal filtration is performed, and the precipitate is rinsed with ethanol several times and then dried in an oven at 80°C to constant weight to obtain stearic acid modified titanium oxide powder.

[0015] As a preferred embodiment, the prepreg glue contains, by weight percentage: epoxy resin: 20% to 40%; silicone resin: 15% to 35%; nano-scale filler I: 1% to 10%; micron-scale filler II: 1% to 10%; curing agent: 10% to 20%; solvent: 10% to 20%.

[0016] As a preferred embodiment, the hydrophobic anti-icing prepreg further contains 1% to 2% of an auxiliary agent by weight percentage; the auxiliary agent is a dispersant, and the dispersant is selected from at least one of BYK161 or BYK163.

[0017] On the other hand, the present invention also provides a method for preparing any of the above-mentioned anti-hydrophobic and anti-icing prepreg glue solutions, wherein epoxy resin, silicone resin, nano-scale filler I, micron-scale filler II, curing agent and solvent are mixed to obtain the hydrophobic and anti-icing prepreg glue solution.

[0018] As a preferred embodiment, the mixing temperature is 20 to 40°C.

[0019] As a preferred embodiment, the stirring speed of the mixing is 1000 to 2000 rpm.

[0020] In another aspect, the present invention also provides a method for preparing any of the above-mentioned hydrophobic anti-icing prepregs, wherein the prepreg solution is coated on the surface of a fiber fabric, and then desolventized and solidified to obtain the hydrophobic anti-icing prepreg.

[0021] As a preferred technical solution, the desolvation conditions include: temperature 80-140° C., preferably 120° C., and time 10-30 min.

[0022] As a preferred technical solution, the curing conditions include: temperature 150-200° C., time 10-30 min.

[0023] As a preferred technical solution, the volume content of the fiber fabric is 50% to 60% calculated based on the total weight of the pre-impregnated adhesive and the fiber fabric.

[0024] As one of the specific implementation methods, the prepreg is coated on the surface of the fiber fabric, placed in a 120°C oven for desolventizing for 10 to 30 minutes, then heated to 150 to 200°C for 10 to 30 minutes for precuring, and the desolventizing and precuring steps are repeated several times until the prepreg completely penetrates the fiber fabric, thereby preparing an anti-icing prepreg.

[0025] As a preferred embodiment, the fiber fabric is selected from at least one of carbon fiber, glass fiber and aramid.

[0026] As a preferred embodiment, the water contact angle of the hydrophobic anti-icing prepreg is ≥124°, and the ice adhesion is ≤90 / KPa.

[0027] The ice adhesion of the hydrophobic anti-icing prepreg is selected from any value among 90 KPa, 65 KPa, 50 KPa or any range between the two.

[0028] The water contact angle of the hydrophobic anti-icing prepreg is selected from any value among 124°, 135°, 137° or any range between the two.

[0029] The present invention prepares a hydrophobic anti-icing prepreg, which can be coated on the surface of a fiber fabric and precured to obtain an anti-icing prepreg. After further curing and molding, the anti-icing prepreg has hydrophobic and anti-icing properties on the surface, and can be used as an outer protective layer to improve the weather resistance of the composite material. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0031] The instruments and materials used in the examples and comparative examples of the present invention are described as follows.

[0032] Bisphenol A epoxy resin, containing two epoxy groups, with a viscosity of 12800 Pa.s at 25°C, was purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd., with the brand name: NPEL-128

[0033] Methylphenyl silicone resin, in which the molar content of phenyl is 30%, purchased from Jiangsu Sanmu Group Co., Ltd., brand: SM1053G

[0034] Methyl etherified amino resin, purchased from Jiangsu Sanmu Group Co., Ltd., brand: SM5747

[0035] Fiber fabric is 200g / m 2 3k small tow carbon fiber plain cloth, purchased from Japan Toray carbon fiber cloth, brand UT70-20;

[0036] Dispersants BYK161 and BYK163 were purchased from BYK Chemical Company.

[0037] Preparation method of hydrophobic anti-icing prepreg and prepreg:

[0038] S1: bisphenol A epoxy resin, silicone resin, nano filler, micro filler, solvent, curing agent and additive are mixed uniformly under high-speed stirring to prepare a prepreg glue solution;

[0039] S2: Degassing the prepreg glue solution under vacuum degree ≤-0.085MPa for 20-30min;

[0040] S3: evenly coating the impregnation solution prepared in S2 on the surface of the composite fabric, so that the impregnation solution fully infiltrates and penetrates between the fibers;

[0041] S4: placing the impregnated fabric prepared in S3 in a 120° C. oven to remove the solvent for 10 to 30 minutes, and then heating the oven to 150 to 200° C. for 10 to 30 minutes for pre-curing;

[0042] S5: Repeat steps S3 and S4 2 to 5 times until the prepreg completely permeates the fiber fabric to obtain a hydrophobic anti-icing prepreg.

[0043] Preparation Example

[0044] Preparation of stearic acid modified titanium oxide powder: Stearic acid is added to ethanol and stirred evenly to form a mixed solution. The mass concentration of stearic acid in the mixed solution is 8%. Titanium oxide powder is added in a mass ratio of 2:1 between the solution and titanium oxide (particle size D90≈8 microns). The reaction is carried out by mechanical stirring at 30°C for 60 minutes. After the reaction is completed, centrifugal filtration is performed, and the precipitate is rinsed with ethanol several times, dried in an oven at 80°C to constant weight, and ground to obtain stearic acid modified titanium oxide powder (particle size D90≈8 microns).

[0045] Example 1

[0046] Step 1: 20 g of bisphenol A epoxy resin, 35 g of methylphenyl silicone resin, 10 g of nano silicon oxide (average particle size of 50 nm), 5 g of stearic acid-modified titanium oxide powder (obtained in Preparation Example 1), 18 g of mixed solvent (9 g of xylene, 9 g of n-butanol), 10 g of methyl etherified amino resin, and 2 g of BYK161 were mixed in a high-speed stirrer at a temperature of about 25° C. and a stirring speed of 2000 rpm to prepare a dipping solution;

[0047] Step 2: Place the prepreg glue solution in a vacuum environment of ≤-0.085MPa for 20 minutes for degassing treatment;

[0048] Step 3: evenly apply the prepared impregnation solution on the surface of the fiber fabric, so that the impregnation solution fully infiltrates and penetrates between the fibers;

[0049] Step 4: The impregnated fabric prepared above is placed in a 120° C. oven for desolventizing for 10 minutes, and then the temperature is raised to 180° C. and heated for 30 minutes for pre-curing;

[0050] Step 5: Repeat steps 3 and 4 three times until the prepreg liquid completely permeates the fiber fabric to obtain prepreg A with a fiber volume content of 55%.

[0051] Example 2

[0052] Step 1: 40 g of bisphenol A epoxy resin, 15 g of methylphenyl silicone resin, 8 g of nano zinc oxide (average particle size of 80 nm), 1 g of stearic acid-modified titanium oxide powder (obtained in Preparation Example 1), 20 g of mixed solvent (6 g of xylene, 14 g of n-butanol), 15 g of methyl etherified amino resin, and 1 g of BYK161 additive were mixed in a high-speed stirrer at a temperature of about 25° C. and a stirring speed of 2000 rpm to prepare a dipping solution;

[0053] Step 2: Place the prepreg glue solution in a vacuum environment of ≤-0.085MPa for 30 minutes for degassing treatment;

[0054] Step 3: evenly apply the prepared impregnation solution on the surface of the fiber fabric, so that the impregnation solution fully infiltrates and penetrates between the fibers;

[0055] Step 4: Place the impregnated fabric prepared above in an oven at 120° C. for desolventizing for 30 minutes, then heat to 190° C. for 20 minutes for pre-curing;

[0056] Step 5: Repeat steps 2 and 3 twice until the prepreg liquid completely permeates the fiber fabric to obtain prepreg B with a fiber volume content of 53%.

[0057] Example 3

[0058] Step 1: 30 g of bisphenol A epoxy resin, 30 g of methylphenyl silicone resin, 5 g of nano-alumina (average particle size of 80 nm), 8 g of stearic acid-modified titanium oxide powder (obtained in Preparation Example 1), 10 g of mixed solvent (5 g of xylene, 5 g of n-butanol), 16 g of methyl etherified amino resin, and 1 g of BYK161 additive were mixed in a high-speed stirrer at a temperature of about 25° C. and a stirring speed of 2000 rpm to prepare a dipping solution;

[0059] Step 2: Place the prepreg glue solution in a vacuum environment of ≤-0.085MPa for 30 minutes for degassing treatment;

[0060] Step 3: evenly apply the prepared impregnation solution on the surface of the fiber fabric, so that the impregnation solution fully infiltrates and penetrates between the fibers;

[0061] Step 4: Place the impregnated fabric prepared above in an oven at 120° C. for desolventizing for 30 minutes, then heat to 150° C. for 20 minutes for pre-curing;

[0062] Step 5: Repeat steps 2 and 3 four times until the prepreg liquid completely permeates the fiber fabric, to obtain prepreg C with a fiber volume content of 58%.

[0063] Comparative Example 1

[0064] Step 1: 20 g of bisphenol A epoxy resin, 10 g of nano silicon oxide, 5 g of stearic acid-modified titanium oxide powder (obtained in Preparation Example 1), 18 g of mixed solvent (9 g of xylene, 9 g of n-butanol), 10 g of methyl etherified amino resin, and 2 g of BYK161 additive were mixed in a high-speed stirrer at a temperature of about 25° C. and a stirring speed of 2000 rpm to prepare a dipping solution;

[0065] Step 2: Place the prepreg glue solution in a vacuum environment of ≤-0.085MPa for 20 minutes for degassing treatment;

[0066] Step 3: Evenly apply the prepared impregnation solution on the surface of the fiber fabric to allow the impregnation solution to fully infiltrate and penetrate between the fibers.

[0067] Step 4: Place the impregnated fabric prepared above in an oven at 120° C. for desolventizing for 10 minutes, then heat to 180° C. for 30 minutes for pre-curing;

[0068] Step 5: Repeat steps 3 and 4 three times until the prepreg liquid completely permeates the fiber fabric to obtain a prepreg M with a fiber volume content of 52%.

[0069] Comparative Example 2

[0070] Step 1: 20 g of bisphenol A epoxy resin, 35 g of methylphenyl silicone resin, 10 g of nano silicon oxide (average particle size of 50 nm), 5 g of ordinary titanium oxide powder, 18 g of mixed solvent (9 g of xylene, 9 g of n-butanol), 10 g of methyl etherified amino resin, and 2 g of BYK161 additive are mixed in a high-speed stirrer at a temperature of about 25° C. and a stirring speed of 2000 rpm to prepare a dipping solution;

[0071] Step 2: Place the prepreg glue solution in a vacuum environment of ≤-0.085MPa for 20 minutes for degassing treatment;

[0072] Step 3: Evenly apply the prepared impregnation solution on the surface of the fiber fabric, so that the impregnation solution fully infiltrates and penetrates between the fibers. Step 4: Place the impregnated fabric prepared above in a 120°C oven to remove the solvent for 10 minutes, then heat it to 180°C for 30 minutes for pre-curing;

[0073] Step 5: Repeat steps 3 and 4 three times until the prepreg liquid completely permeates the fiber fabric to obtain prepreg N with a fiber volume content of 55%.

[0074] Test Case

[0075] Prepreg A, prepreg B, and prepreg C prepared in Examples 1 to 3, and prepreg M and prepreg N prepared in Comparative Examples 1-2 were respectively used as prepregs and cured by hot pressing at a temperature of 180° C. for 120 min. After complete curing, a fiber-reinforced cured composite material was obtained.

[0076] The curing effects of prepreg A, prepreg B and prepreg C were good without delamination and blistering.

[0077] Prepreg M, because methylphenyl silicone resin is not used, the prepared prepreg lacks toughness components, resulting in warping during the curing process and delamination of the rear layers after curing.

[0078] Prepreg N, good curing effect, no delamination and blistering.

[0079] The fiber-reinforced cured composite material was used as a substrate sample and the following tests were performed. The test results are shown in Tables 1 and 2.

[0080] Test ice adhesion: The test method is to place 5 plastic rings of fixed size (inner diameter 31mm, wall thickness 3mm, height 25mm) horizontally on the surface of the substrate sample at -20℃, pour 6mL of 5℃ ice-water mixture, let it stand for 24h, and then use a tensile gauge to measure the minimum horizontal tension that causes the steel ring to move.

[0081] Test the water contact angle: The test method is to use the LSA100 contact angle meter produced by LAUDA Scientific of Germany.

[0082] Test the water contact angle after 50 frictions: The water contact angle is tested after the substrate sample is abraded 50 times using an abrasion tester. The abrasion tester has a CS-10 roller model and a load of 250 g.

[0083] Table 1

[0084]

[0085] Table 2

[0086]

[0087] The test results show that the cured composite materials obtained by curing the prepreg A, prepreg B and prepreg C prepared in Examples 1-3 have a water contact angle of more than 124°, have a significant hydrophobic effect, and an ice adhesion of less than 90 KPa, which can reduce the formation of ice and the difficulty of removing ice, and still have good hydrophobicity after being worn 50 times.

[0088] The prepreg M prepared in Comparative Example 1 does not use methylphenyl silicone resin. Due to the lack of toughness components in the prepared prepreg layer, the surface layer is delaminated, the water effect is reduced, and the contact angle decreases significantly after abrasion.

[0089] The prepreg N prepared in Comparative Example 2 does not use the micron-sized titanium oxide powder prepared by the present invention, and has a reduced hydrophobic effect and a weakened anti-icing effect.

[0090] The data comparison of the above comparative examples shows that the hydrophobic anti-icing prepreg and prepreg prepared by the present invention have good hydrophobic and anti-icing properties through the synergistic compounding of silicone resin, nanofiller and micron filler.

[0091] Any numerical value mentioned in the present invention includes all values ​​that increase by one unit each time from the lowest value to the highest value if there is only an interval of two units between any minimum value and any maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is declared to be 50-90, in this specification it means that 51-89, 52-88... and 69-71 and 70-71 are specifically listed. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 can be appropriately considered as a unit. These are just some specially specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed lowest and highest values ​​are considered to have been disclosed.

[0092] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. Hydrophobic anti-icing prepreg, characterized in that: It includes epoxy resin, silicone resin, nano-scale filler I, micro-scale filler II, curing agent and solvent; The nanoscale filler I is selected from any one of silicon oxide, zinc oxide and aluminum oxide; The micron-sized filler II is titanium oxide powder modified by stearic acid.

2. The hydrophobic anti-icing prepreg according to claim 1, characterized in that: The epoxy resin is a bifunctional epoxy resin with a viscosity of 10000-2000 mPa.s at 25°C; And / or, the organic silicon resin is a methylphenyl silicone resin, and preferably, the molar content of phenyl groups in the methylphenyl silicone resin is ≥30%; And / or, the curing agent is a methyl etherified amino resin; And / or, the solvent is a mixture of xylene and n-butanol, and the mass ratio of xylene to n-butanol is (3-5):(7:5).

3. The hydrophobic anti-icing prepreg according to claim 1 or 2, characterized in that: The mass ratio of the nano-scale filler I to the micro-scale filler II is 1:10 to 10:1; and / or, the particle size of the nanoscale filler I is in the range of 30 to 300 nm; and / or, the particle size of the micron-sized filler I ranges from 5 to 50 μm; The stearic acid-modified titanium oxide powder is obtained by mixing titanium oxide with an ethanol solution of stearic acid; Preferably, the stearic acid-modified titanium oxide powder is prepared by mixing stearic acid with ethanol to obtain a mixed solution, wherein the mass concentration of stearic acid in the mixed solution is 5% to 10%; titanium oxide is then added in a mass ratio of 2:1 to 5:1 between the mixed solution and titanium oxide, and the mixture is reacted at 30 to 35° C. for 30 to 60 minutes.

4. The hydrophobic anti-icing prepreg according to any one of claims 1 to 3, characterized in that: The prepreg solution contains, by weight percentage: Epoxy resin: 20% to 40%; Silicone resin: 15% to 35%; Nano-scale filler I: 1% to 10%; Micron-sized filler II: 1% to 10%; Curing agent: 10%~20%; Solvent: 10%~20%.

5. The hydrophobic anti-icing prepreg according to any one of claims 1 to 4, characterized in that: The hydrophobic anti-icing prepreg further contains 1% to 2% of an additive by weight percentage; The auxiliary agent is a dispersant; The dispersant is selected from at least one of BYK161 and BYK163.

6. The method for preparing the anti-hydrophobic and anti-icing prepreg according to any one of claims 1 to 5, characterized in that: The epoxy resin, the silicone resin, the nano-scale filler I, the micro-scale filler II, the curing agent and the solvent are mixed to obtain the hydrophobic anti-icing prepreg glue solution; Preferably, the mixing temperature is 20 to 40°C; Preferably, the stirring speed of the mixing is 1000 to 2000 rpm.

7. A method for preparing a hydrophobic anti-icing prepreg, characterized in that: The prepreg glue solution described in any one of claims 1 to 5 is coated on the surface of the fiber fabric, and the hydrophobic anti-icing prepreg glue material is obtained after desolventizing and curing.

8. The preparation method according to claim 7, characterized in that: The desolvation conditions include: temperature 80-140°C, preferably 120°C, time 10-30 min; And / or, the curing conditions include: temperature 150-200°C, time 10-30min; And / or, the volume content of the fiber fabric is 50% to 60% based on the total weight of the pre-impregnated adhesive solution and the fiber fabric.

9. The preparation method according to claim 8, characterized in that: The fiber fabric is selected from at least one of carbon fiber, glass fiber and aramid.

10. The hydrophobic anti-icing prepreg obtained by the preparation method according to claim 8 or 9, wherein the hydrophobic anti-icing prepreg has a water contact angle of ≥124° and an ice adhesion of ≤90 / KPa.

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