A two-component epoxy resin for vacuum diversion and its preparation method

Abstract

The present invention relates to the technical field of epoxy resins, and particularly to a two-component epoxy resin for vacuum casting and a preparation method thereof. The two-component epoxy resin is composed of component A and component B in a weight ratio of 100:20-30. After curing, the surface of the carbon fiber product is bright and pore-free, with good weather resistance, bright surface and high transparency, which is more conducive to subsequent surface painting processing, and has better strength and toughness. Under the combined action of polyurethane-modified epoxy resin, inorganic filler, defoaming agent and leveling agent in component A, it is beneficial to improve the dispersibility of component A and promote the cured surface to present a soft, flat and pore-free effect, which is beneficial to the brightness and transparency of the product surface, and more beneficial to improve strength and toughness. Under the action of benzyl alcohol in component B, it helps to improve the fluidity of the epoxy resin, promote the reaction, improve the toughness, and jointly act with component A to significantly improve the gloss and brightness of the product surface, facilitating subsequent surface painting processing.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resins, and particularly relates to a two-component epoxy resin for vacuum infusion and a preparation method thereof. Background Art

[0002] The vacuum infusion process (also known as VARTM, SCRIMP, VIP, etc.) is a lamination process for producing fiber-reinforced plastic (FRP) parts. In this process, under a high-vacuum environment, the resin is pressed into dry materials (such as felts, fabrics, stitched felts, and foam cores) by atmospheric pressure, and the pressure difference between the vacuum gap and the external atmospheric pressure presses the resin into the porous material until it is completely infiltrated. The vacuum is maintained until the part is cured, thereby manufacturing a dense composite part.

[0003] However, after the existing carbon fibers are processed with vacuum infusion epoxy resin, affected by the composite materials in the epoxy resin, the product surface is dull, there are many micropores, and the weather resistance is insufficient, which is not conducive to subsequent processing operations such as surface painting, and the toughness fails to meet the requirements. Summary of the Invention

[0004] In order to overcome the disadvantages and deficiencies existing in the prior art, one of the purposes of the present invention is to provide a two-component epoxy resin for vacuum infusion.

[0005] Another purpose of the present invention is to provide a preparation method of a two-component epoxy resin for vacuum infusion. The preparation method is simple to operate, convenient to control, has high production efficiency, low production cost, and can be used for large-scale production.

[0006] One of the purposes of the present invention is achieved by the following technical solution: A two-component epoxy resin for vacuum infusion, which is composed of component A and component B in a weight ratio of 100:20 - 30;

[0007] Component A includes the following raw materials in parts by weight:

[0008] Bisphenol A epoxy resin 50 - 80 parts

[0009] Bisphenol F epoxy resin 15 - 25 parts

[0010] Polyurethane-modified epoxy resin 8 - 12 parts

[0011]

[0012] Component B includes the following raw materials in parts by weight:

[0013] Polyetheramine curing agent 10 - 20 parts

[0014] Alicyclic amine curing agent 20 - 30 parts

[0015] 10 - 12 parts of benzyl alcohol.

[0016] This two - component epoxy resin for vacuum guiding uses component A as the main resin component and component B as the main curing component. After being mixed in proportion, it has low viscosity and good fluidity, is suitable for vacuum guiding, and after curing, the surface of the carbon fiber product is bright and pore - free, with good weather resistance, bright surface and high transparency, which is more conducive to subsequent surface painting processing, and has better strength and toughness. Among them, in component A, bisphenol A - type epoxy resin is used as the main resin, and bisphenol F - type epoxy resin and epoxy diluent are added to jointly reduce the overall viscosity of component A. Component A and component B jointly control the viscosity of this two - component epoxy resin within 500 - 800 mPa·s. And the blend of bisphenol F - type epoxy resin, bisphenol A - type epoxy resin and polyurethane - modified epoxy resin synergistically exhibits good weather resistance and anti - aging properties. Under the combined action of special polyurethane - modified epoxy resin, inorganic filler, defoamer and leveling agent, it is beneficial to improve the dispersibility of component A and can promote the cured surface to present a soft, flat and pore - free effect, which is beneficial to the brightness and transparency of the product surface and is more conducive to improving strength and toughness. In component B, polyetheramine - type curing agent and cycloaliphatic amine - type curing agent are used synergistically to cure the two - component epoxy resin, promote the curing speed, and are beneficial to improving weather resistance, water resistance, surface transparency and mechanical properties. Under the action of benzyl alcohol, it not only helps to improve the fluidity of the epoxy resin, promotes the reaction of polyetheramine - type curing agent and cycloaliphatic amine - type curing agent with the epoxy resin in component A, improves the toughness of the cured product, but also, under the combined action with the special polyurethane - modified epoxy resin, inorganic filler, defoamer and leveling agent in component A, can significantly improve the gloss, brightness and transparency of the product surface, which is more conducive to subsequent surface painting processing.

[0017] Preferably, the bisphenol A - type epoxy resin is E44; the bisphenol F - type epoxy resin is EXA - 830CRP or EXA - 830LVP.

[0018] Preferably, the preparation method of each part of the polyurethane - modified epoxy resin comprises the following steps:

[0019] (R1), take 2.5 - 3.5 parts of polyether polyol, 8.5 - 9.5 parts of isocyanate, 85 - 95 parts of epoxy resin E44, 8 - 12 parts of hydroxyl - terminated hyperbranched polyester and 1 - 2 parts of organotin catalyst by weight, and set aside;

[0020] (R2), add polyether polyol and isocyanate into the reaction kettle for mixing, introduce nitrogen, heat up to 60 - 120 °C and stir for 2 - 3 h, then cool to room temperature to obtain a polyurethane prepolymer;

[0021] (R3) Preheat epoxy resin E44 at 100 - 140 °C for 4 - 6 h to remove moisture and volatiles therein, and evacuate until the bubbles disappear to obtain pretreated epoxy resin;

[0022] (R4) Add polyurethane prepolymer, hydroxyl - terminated hyperbranched polyester and organotin catalyst to the pretreated epoxy resin, heat up to 100 - 140 °C, and perform high - speed homogeneous shear stirring at 1000 - 1500 rpm for 1 h, continue the reaction for 3 - 6 h, then evacuate and hold for 15 min to remove the bubbles in the liquid material, thus obtaining the polyurethane - modified epoxy resin.

[0023] Adopting the above - mentioned technical solution, the prepared polyurethane - modified epoxy resin has rigid molecules of polyurethane - modified epoxy resin uniformly dispersed in the epoxy matrix at the molecular level to form a molecular composite material. The whole system is similar to a semi - interpenetrating network. These rigid molecules can enhance the matrix, improve the tensile strength of the matrix, and at the same time prevent cracks and increase the toughness of the matrix, and promote the cured surface to present a soft, flat and pore - free effect. Further introducing hydroxyl - terminated hyperbranched polyester can further enhance the strength and toughness.

[0024] Preferably, the polyether polyol is polyethylene glycol or polypropylene glycol; the isocyanate is at least one of diphenylmethane diisocyanate, isophorone diisocyanate and p - phenylene diisocyanate.

[0025] Preferably, the hydroxyl - terminated hyperbranched polyester is H303; the organotin catalyst is dibutyltin dilaurate.

[0026] Preferably, the epoxy diluent is a mixture of glycidyl methacrylate and 2 - tolyl glycidyl ether.

[0027] Adopting the above - mentioned technical solution, more preferably, the epoxy diluent is a mixture of glycidyl methacrylate and 2 - tolyl glycidyl ether in a weight ratio of 1 - 3:5, which is beneficial to improving heat resistance. And glycidyl methacrylate contains both a carbon - carbon double bond and an epoxy group in its molecule, and the unique structure and steric hindrance of 2 - tolyl glycidyl ether can significantly enhance the toughness and impact resistance of the cured epoxy resin, thus enhancing the mechanical properties of the overall material.

[0028] Preferably, the inorganic filler is quartz powder and glass powder.

[0029] Adopting the above - mentioned technical solution, more preferably, the inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 1 - 2:8. The two act synergistically, having a high surface energy, good compatibility and good filling effect in the system, effectively improving the impact strength and tensile strength, and promoting surface transparency and weather resistance.

[0030] Preferably, the defoaming agent is BYK-A530 or ACP-1400, and the leveling agent is polydimethylsiloxane or polymethylphenylsiloxane.

[0031] With the above technical solution, the above defoaming agent has high temperature resistance, acid and alkali resistance, low toxicity, and good dispersion performance, and can effectively inhibit the formation of bubbles; the above leveling agent can significantly improve the leveling property of the system, and at the same time improve the gloss and feel of the product surface.

[0032] Preferably, the polyetheramine curing agent is D-230; the alicyclic amine curing agent is 1,3-cyclohexanedimethanamine and isophorone diamine.

[0033] With the above technical solution, more preferably, the alicyclic amine curing agent is a mixture of 1,3-cyclohexanedimethanamine and isophorone diamine in a weight ratio of 3:1-2, with a faster curing speed, better low-temperature weather resistance, better water resistance, and the ability to resist yellowing, and has characteristics such as low viscosity, clear transparency, good mechanical properties and excellent weather resistance, which can significantly improve production efficiency and product quality.

[0034] The second object of the present invention is achieved by the following technical solution: The preparation method of the above two-component epoxy resin for vacuum casting includes the following steps:

[0035] (S1) Weigh bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane-modified epoxy resin, epoxy diluent, inorganic filler, defoaming agent and leveling agent by weight, mix them evenly, evacuate until the bubbles are eliminated, and filter to remove impurities to obtain component A;

[0036] (S2) Weigh polyetheramine curing agent, alicyclic amine curing agent and benzyl alcohol by weight, mix them evenly, and filter to remove impurities to obtain component B;

[0037] When this two-component epoxy resin is applied to the vacuum casting process, component A and component B are mixed evenly by weight, and the obtained two-component epoxy resin is introduced into a mold with a carbon fiber product by evacuation, and then cured by standing at room temperature for 23-25 h or cured by heating to 60-70 °C for 30-60 min.

[0038] The beneficial effects of the present invention are as follows: The two-component epoxy resin for vacuum casting of the present invention uses component A as the main resin component and component B as the main curing component. After mixing in proportion, it has low viscosity and good fluidity, is suitable for vacuum casting, and the surface of the cured carbon fiber product is bright and pore-free, with good weather resistance, bright surface and high transparency, which is more conducive to subsequent surface painting processing, and has better strength and toughness.

[0039] The preparation method of the present invention is simple to operate, convenient to control, has high production efficiency and low production cost, and can be used for large-scale production. Detailed Embodiments

[0040] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments. The content mentioned in the embodiments does not limit the present invention.

[0041] Embodiment 1

[0042] A two-component epoxy resin for vacuum diversion is composed of component A and component B in a weight ratio of 100:25;

[0043] Component A includes the following raw materials in parts by weight:

[0044]

[0045] Component B includes the following raw materials in parts by weight:

[0046] Polyetheramine curing agent 15 parts

[0047] Alicyclic amine curing agent 25 parts

[0048] Benzyl alcohol 11 parts.

[0049] The bisphenol A epoxy resin is E44; the bisphenol F epoxy resin is EXA-830CRP.

[0050] The preparation method of each part of the polyurethane-modified epoxy resin includes the following steps:

[0051] (R1), Take 3 parts of polyether polyol, 9 parts of isocyanate, 90 parts of epoxy resin E44, 10 parts of hydroxyl-terminated hyperbranched polyester and 1.5 parts of organotin catalyst by weight, and set aside;

[0052] (R2), Add the polyether polyol and isocyanate into the reaction kettle for mixing, introduce nitrogen, heat up to 90 °C and stir for 2.5 h, then cool to room temperature to obtain a polyurethane prepolymer;

[0053] (R3), Preheat the epoxy resin E44 at 120 °C for 5 h to remove the moisture and volatiles therein, evacuate until the bubbles are eliminated to obtain a pretreated epoxy resin;

[0054] (R4), Add the polyurethane prepolymer, hydroxyl-terminated hyperbranched polyester and organotin catalyst to the pretreated epoxy resin, heat up to 120 °C, and perform high-speed homogeneous shear stirring at 1200 rpm for 1 h, continue the reaction for 4 h, then evacuate and hold for 15 min to remove the bubbles in the liquid material, thus obtaining the polyurethane-modified epoxy resin.

[0055] The polyether polyol is polypropylene glycol; the isocyanate is a mixture of diphenylmethane diisocyanate, isophorone diisocyanate and p-phenylene diisocyanate in a weight ratio of 1:2:1.

[0056] The hydroxyl-terminated hyperbranched polyester is H303; the organotin catalyst is dibutyltin dilaurate.

[0057] The epoxy diluent is a mixture of glycidyl methacrylate and 2-tolyl glycidyl ether in a weight ratio of 2:5.

[0058] The inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 1.5:8.

[0059] The defoaming agent is BYK-A530, and the leveling agent is polydimethylsiloxane.

[0060] The polyetheramine curing agent is D-230; the alicyclic amine curing agent is a mixture of 1,3-cyclohexanedimethanamine and isophorone diamine in a weight ratio of 3:1.5.

[0061] The preparation method of the two-component epoxy resin for vacuum casting includes the following steps:

[0062] (S1) Take bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane-modified epoxy resin, epoxy diluent, inorganic filler, defoaming agent and leveling agent by weight, mix them evenly, evacuate until the bubbles are eliminated, and filter to remove impurities to obtain component A;

[0063] (S2) Take polyetheramine curing agent, alicyclic amine curing agent and benzyl alcohol by weight, mix them evenly, and filter to remove impurities to obtain component B.

[0064] Example 2

[0065] A two-component epoxy resin for vacuum casting consists of component A and component B in a weight ratio of 100:20;

[0066] Component A includes the following raw materials in parts by weight:

[0067]

[0068] Component B includes the following raw materials in parts by weight:

[0069] Polyetheramine curing agent 10 parts

[0070] Alicyclic amine curing agent 20 parts

[0071] Benzyl alcohol 10 parts.

[0072] The bisphenol A type epoxy resin is E44; the bisphenol F type epoxy resin is EXA-830CRP.

[0073] The preparation method of each portion of the polyurethane modified epoxy resin comprises the following steps:

[0074] (R1) Weigh 2.5 parts of polyether polyol, 8.5 parts of isocyanate, 85 parts of epoxy resin E44, 8 parts of hydroxyl-terminated hyperbranched polyester and 1 part of organotin catalyst by weight, and set aside;

[0075] (R2) Add the polyether polyol and isocyanate into a reaction kettle for mixing, introduce nitrogen, heat up to 60°C and stir for 2 h, then cool to room temperature to obtain a polyurethane prepolymer;

[0076] (R3) Preheat the epoxy resin E44 at 100°C for 4 h to remove the moisture and volatiles therein, evacuate until the bubbles are eliminated to obtain a pretreated epoxy resin;

[0077] (R4) Add the polyurethane prepolymer, hydroxyl-terminated hyperbranched polyester and organotin catalyst to the pretreated epoxy resin, heat up to 100°C, and carry out high-speed homogeneous shear stirring at 1000 rpm for 1 h, continue the reaction for 3 h, then evacuate and keep it for 15 min to remove the bubbles in the liquid material, thus obtaining the polyurethane modified epoxy resin.

[0078] The polyether polyol is polypropylene glycol; the isocyanate is a mixture of diphenylmethane diisocyanate, isophorone diisocyanate and p-phenylene diisocyanate in a weight ratio of 1:2:1.

[0079] The hydroxyl-terminated hyperbranched polyester is H303; the organotin catalyst is dibutyltin dilaurate.

[0080] The epoxy diluent is a mixture of glycidyl methacrylate and 2-tolyl glycidyl ether in a weight ratio of 1:5.

[0081] The inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 1:8.

[0082] The defoaming agent is ACP-1400, and the leveling agent is polymethylphenylsiloxane.

[0083] The polyetheramine curing agent is D-230; the cycloaliphatic amine curing agent is a mixture of 1,3-cyclohexanedimethanamine and isophorone diamine in a weight ratio of 3:1.

[0084] The preparation method of the two-component epoxy resin for vacuum casting comprises the following steps:

[0085] (S1) Take bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane-modified epoxy resin, epoxy diluent, inorganic filler, defoamer and leveling agent by weight parts, mix them evenly, evacuate until the bubbles are eliminated, filter to remove impurities, and obtain Component A;

[0086] (S2) Take polyetheramine curing agent, cycloaliphatic amine curing agent and benzyl alcohol by weight parts, mix them evenly, filter to remove impurities, and obtain Component B.

[0087] Example 3

[0088] A two-component epoxy resin for vacuum resin infusion consists of Component A and Component B in a weight ratio of 100:30;

[0089] Component A includes the following raw materials by weight parts:

[0090]

[0091] Component B includes the following raw materials by weight parts:

[0092] Polyetheramine curing agent 20 parts

[0093] Cycloaliphatic amine curing agent 30 parts

[0094] Benzyl alcohol 12 parts.

[0095] The bisphenol A epoxy resin is E44; the bisphenol F epoxy resin is EXA-830CRP.

[0096] The preparation method of each part of the polyurethane-modified epoxy resin includes the following steps:

[0097] (R1) Take 3.5 parts of polyether polyol, 9.5 parts of isocyanate, 95 parts of epoxy resin E44, 12 parts of hydroxyl-terminated hyperbranched polyester and 2 parts of organotin catalyst by weight parts, and set aside;

[0098] (R2) Add polyether polyol and isocyanate into the reaction kettle and mix them, introduce nitrogen, heat up to 120 °C and stir for 3 h, then cool to room temperature to obtain polyurethane prepolymer;

[0099] (R3) Preheat epoxy resin E44 at 140 °C for 6 h to remove the moisture and volatiles in it, evacuate until the bubbles are eliminated, and obtain pretreated epoxy resin;

[0100] (R4) Add polyurethane prepolymer, hydroxyl-terminated hyperbranched polyester and organotin catalyst to the pretreated epoxy resin, heat up to 140 °C, and stir at a high speed of 1500 rpm for 1 h with homogeneous shear, continue to react for 6 h, then evacuate and keep for 15 min to remove the bubbles in the liquid material, and obtain the polyurethane-modified epoxy resin.

[0101] The polyether polyol is polypropylene glycol; the isocyanate is a mixture of diphenylmethane diisocyanate, isophorone diisocyanate and p-phenylene diisocyanate in a weight ratio of 1:2:1.

[0102] The hydroxyl-terminated hyperbranched polyester is H303; the organotin catalyst is dibutyltin dilaurate.

[0103] The epoxy diluent is a mixture of glycidyl methacrylate and 2-tolyl glycidyl ether in a weight ratio of 3:5.

[0104] The inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 2:8.

[0105] The defoaming agent is BYK-A530, and the leveling agent is polydimethylsiloxane.

[0106] The polyetheramine curing agent is D-230; the cycloaliphatic amine curing agent is a mixture of 1,3-cyclohexanedimethanamine and isophorone diamine in a weight ratio of 3:2.

[0107] The preparation method of the two-component epoxy resin for vacuum resin infusion molding includes the following steps:

[0108] (S1) Weigh bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane-modified epoxy resin, epoxy diluent, inorganic filler, defoaming agent and leveling agent by parts by weight, mix them evenly, evacuate until the bubbles are eliminated, and filter to remove impurities to obtain component A;

[0109] (S2) Weigh polyetheramine curing agent, cycloaliphatic amine curing agent and benzyl alcohol by parts by weight, mix them evenly, and filter to remove impurities to obtain component B.

[0110] Example 4

[0111] A two-component epoxy resin for vacuum resin infusion molding consists of component A and component B in a weight ratio of 100:27;

[0112] Component A includes the following raw materials by parts by weight:

[0113] Bisphenol A epoxy resin 70 parts

[0114] Bisphenol F epoxy resin 18 parts

[0115] Polyurethane-modified epoxy resin 11 parts

[0116] Epoxy diluent 16 parts

[0117] Inorganic filler 14 parts

[0118] Defoaming agent 0.7 part

[0119] Leveling agent: 0.4 parts

[0120] The component B comprises the following raw materials in parts by weight:

[0121] Polyetheramine curing agent: 17 parts

[0122] Alicyclic amine curing agent: 27 parts

[0123] Benzyl alcohol: 11 parts

[0124] The bisphenol A epoxy resin is E44; the bisphenol F epoxy resin is EXA-830CRP.

[0125] The preparation method of each part of the polyurethane-modified epoxy resin comprises the following steps:

[0126] (R1) Take 2.8 parts of polyether polyol, 8.8 parts of isocyanate, 88 parts of epoxy resin E44, 11 parts of hydroxyl-terminated hyperbranched polyester and 1.8 parts of organotin catalyst by weight, and set aside;

[0127] (R2) Add the polyether polyol and the isocyanate into a reaction kettle for mixing, introduce nitrogen, heat up to 88°C and stir for 2.3 h, and then cool to room temperature to obtain a polyurethane prepolymer;

[0128] (R3) Preheat the epoxy resin E44 at 130°C for 4.5 h to remove the moisture and volatiles therein, evacuate until the bubbles disappear to obtain a pretreated epoxy resin;

[0129] (R4) Add the polyurethane prepolymer, the hydroxyl-terminated hyperbranched polyester and the organotin catalyst to the pretreated epoxy resin, heat up to 130°C, and perform high-speed homogeneous shear stirring at 1300 rpm for 1 h, continue the reaction for 4.5 h, and then evacuate and hold for 15 min to remove the bubbles in the liquid material, thus obtaining the polyurethane-modified epoxy resin.

[0130] The polyether polyol is polypropylene glycol; the isocyanate is a mixture of diphenylmethane diisocyanate, isophorone diisocyanate and p-phenylene diisocyanate in a weight ratio of 1:2:1.

[0131] The hydroxyl-terminated hyperbranched polyester is H303; the organotin catalyst is dibutyltin dilaurate.

[0132] The epoxy diluent is a mixture of glycidyl methacrylate and 2-methylbenzene glycidyl ether in a weight ratio of 2.3:5.

[0133] The inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 1.3:8.

[0134] The defoamer is BYK-A530, and the leveling agent is polydimethylsiloxane.

[0135] The polyetheramine curing agent is D-230; the alicyclic amine curing agent is a mixture of 1,3-cyclohexanedimethanamine and isophorone diamine in a weight ratio of 3:1.3.

[0136] The preparation method of the two-component epoxy resin for vacuum casting comprises the following steps:

[0137] (S1) Weigh bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane-modified epoxy resin, epoxy diluent, inorganic filler, defoamer and leveling agent by weight, mix them evenly, evacuate until the bubbles are eliminated, filter to remove impurities, and obtain Component A;

[0138] (S2) Weigh polyetheramine curing agent, alicyclic amine curing agent and benzyl alcohol by weight, mix them evenly, filter to remove impurities, and obtain Component B.

[0139] Comparative Example 1

[0140] The difference between this comparative example and Example 1 is that:

[0141] In the preparation method of each portion of the polyurethane-modified epoxy resin, in step (R1), 3 parts of polyether polyol, 9 parts of isocyanate, 100 parts of epoxy resin E44, 0 part of hydroxyl-terminated hyperbranched polyester and 1.5 parts of organotin catalyst are weighed by weight and set aside; that is, the polyurethane-modified epoxy resin does not contain hydroxyl-terminated hyperbranched polyester.

[0142] Comparative Example 2

[0143] The difference between this comparative example and Example 1 is that:

[0144] The epoxy diluent is a mixture of neopentyl glycol diglycidyl ether and 1,4-butanediol diglycidyl ether in a weight ratio of 2:5.

[0145] Comparative Example 3

[0146] The difference between this comparative example and Example 1 is that:

[0147] The inorganic filler is nano-silica.

[0148] Comparative Example 4

[0149] The difference between this comparative example and Example 1 is that:

[0150] Component B comprises the following raw materials by weight:

[0151] Polyetheramine curing agent 21 parts

[0152] Alicyclic amine curing agent 30 parts

[0153] 0 parts of benzyl alcohol; that is, the B component does not contain benzyl alcohol.

[0154] Performance Test of Example 5

[0155] Take the two-component epoxy resins of Examples 1-4 and Comparative Examples 1-4. When preparing the samples, mix the A component and B component of the two-component epoxy resin evenly according to the weight ratio, and introduce the obtained two-component epoxy resin into the mold with ZT6F carbon fiber products by vacuum pumping, and then cure at 65 °C for 45 min to obtain the samples. Test the tensile strength, flexural strength, surface flatness and surface gloss after vacuum guiding and curing with carbon fiber products; the test methods are as follows:

[0156] Tensile strength: The tensile strength of the samples was tested according to the "Standard Test Method for Tensile Properties of Polymer Matrix Composites ASTM D3039".

[0157] Flexural strength: The flexural strength of the samples was tested according to the "Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials ASTM D790".

[0158] Surface flatness: Take the samples and observe whether the surface of the samples is flat, smooth and free of obvious defects.

[0159] Surface gloss: Instrument model: HG60S glossmeter, incident angle: 60°, read the gloss value of the samples.

[0160] The test results are shown in Table 1 below:

[0161]

[0162]

[0163] As can be seen from Table 1 above, for the two-component epoxy resin for vacuum guiding of the present invention, with the A component as the main resin component and the B component as the main curing component, it has low viscosity and good fluidity after being mixed in proportion, is suitable for vacuum guiding, and the surface of the carbon fiber product after curing is bright and pore-free, has good weather resistance, bright surface and high transparency, is more conducive to subsequent surface painting processing, and has better strength and toughness.

[0164] The above embodiments are the preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A two-component epoxy resin for vacuum infusion, characterized in that: It is composed of component A and component B in a weight ratio of 100:20-30; The A component includes the following raw materials in parts by weight: The B component includes the following raw materials in parts by weight: 10-20 parts of polyetheramine curing agent Alicyclic amine curing agent 20-30 parts Benzyl alcohol 10-12 parts; The epoxy diluent is a mixture of glycidyl methacrylate and 2-toluene glycidyl ether; The inorganic filler is a mixture of ultrafine quartz powder and T836 glass powder in a weight ratio of 1-2:8; The preparation method of each polyurethane modified epoxy resin comprises the following steps: (R1), take 2.5-3.5 parts of polyether polyol, 8.5-9.5 parts of isocyanate, 85-95 parts of epoxy resin E44, 8-12 parts of terminal hydroxyl hyperbranched polyester and 1-2 parts of organotin catalyst by weight, and set aside; (R2), adding polyether polyol and isocyanate into a reaction kettle, mixing, introducing nitrogen, heating to 60-120° C. and stirring for 2-3 hours, and then cooling to room temperature to obtain a polyurethane prepolymer; (R3), preheating epoxy resin E44 at 100-140° C. for 4-6 hours to remove moisture and volatiles therein, and evacuating until bubbles are eliminated to obtain a pretreated epoxy resin; (R4), adding a polyurethane prepolymer, a terminal hydroxyl hyperbranched polyester and an organic tin catalyst to the pretreated epoxy resin, raising the temperature to 100-140°C, and performing high-speed homogeneous shear stirring at 1000-1500 rpm for 1 hour, continuing the reaction for 3-6 hours, and then evacuating and maintaining the vacuum for 15 minutes to remove bubbles in the liquid, thereby obtaining the polyurethane modified epoxy resin.

2. A two-component epoxy resin for vacuum infusion according to claim 1, characterized in that: The bisphenol A type epoxy resin is E44; the bisphenol F type epoxy resin is EXA-830CRP or EXA-830LVP.

3. The two-component epoxy resin for vacuum infusion according to claim 1, characterized in that: The polyether polyol is polyethylene glycol or polyoxypropylene glycol; the isocyanate is at least one of diphenylmethane diisocyanate, isophorone diisocyanate and p-phenylene diisocyanate.

4. The two-component epoxy resin for vacuum infusion according to claim 1, characterized in that: The terminal hydroxyl hyperbranched polyester is H303; and the organic tin catalyst is dibutyltin dilaurate.

5. The two-component epoxy resin for vacuum infusion according to claim 1, characterized in that: The defoaming agent is BYK-A530 or ACP-1400, and the leveling agent is polydimethylsiloxane or polymethylphenylsiloxane.

6. The two-component epoxy resin for vacuum infusion according to claim 1, characterized in that: The polyetheramine curing agent is D-230; the alicyclic amine curing agents are 1,3-cyclohexanedimethylamine and isophoronediamine.

7. A method for preparing a two-component epoxy resin for vacuum infusion according to any one of claims 1 to 6, characterized in that: The steps include: (S1), taking bisphenol A epoxy resin, bisphenol F epoxy resin, polyurethane modified epoxy resin, epoxy diluent, inorganic filler, defoamer and leveling agent by weight, mixing them evenly, evacuating until bubbles are eliminated, filtering and removing impurities, and obtaining component A; (S2), taking a polyetheramine curing agent, an alicyclic amine curing agent and benzyl alcohol in parts by weight, mixing them evenly, filtering and removing impurities, and obtaining a component B; When the two-component epoxy resin is used in a vacuum infusion process, component A and component B are uniformly mixed according to a weight ratio, and the obtained two-component epoxy resin is introduced into a mold with a carbon fiber product by vacuuming, and then cured at room temperature for 23-25 ​​hours or heated to 60-70°C for 30-60 minutes.

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