A carbon fiber composite material for a laptop computer shell and its preparation process

Abstract

The present invention relates to the technical field of carbon fiber composite materials, and specifically to a carbon fiber composite material for a notebook computer shell and its preparation process, including the following processes: Lay the carbon fiber cloth flat in a mold, coat it with an epoxy resin composition, and pre-cure to form a pre-cured carbon fiber layer; Inject polyurethane resin successively on the upper and lower surfaces of the pre-cured carbon fiber layer to form a resin layer; Carry out compression molding to form a carbon fiber layer, and obtain the carbon fiber composite material. Through the epoxy resin composition prepared from epoxy resin and a curing agent, the carbon fiber cloth is coated and impregnated to form a carbon fiber layer by compounding, making it have the advantages of light weight, high strength, fast heat dissipation, and good shielding effect. And resin layers with high toughness are arranged on the upper and lower surfaces of the carbon fiber layer, which helps to improve the impact resistance of the prepared carbon fiber composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber composite materials, and particularly to a carbon fiber composite material for a notebook computer shell and a preparation process thereof. Background Art

[0002] Carbon fiber composite materials have many advantages such as high strength, high modulus, low specific gravity, low coefficient of thermal expansion, and corrosion resistance. They not only have the characteristics of high strength and firmness of aluminum-magnesium alloy, but also have the plasticity of engineering plastics, making their comprehensive performance excellent. The carbon fiber composite materials applied to notebook computer shells are mainly divided into four types: short carbon fiber reinforced composite materials, thermosetting continuous carbon fiber composite materials, thermoplastic continuous carbon fiber composite materials, and carbon fiber composite films. Among them, the molding process of using thermosetting continuous carbon fiber composite materials is to impregnate carbon fiber cloth with resin and then lay the cloth flat in a mold, and heat to cure the thermosetting resin to form a notebook computer shell. The commonly used thermosetting resin is epoxy resin, and the surface of the notebook computer shell made of it is relatively brittle and easy to break when dropped. Therefore, we propose a carbon fiber composite material for a notebook computer shell and a preparation process thereof. Summary of the Invention

[0003] The purpose of the present invention is to provide a carbon fiber composite material for a notebook computer shell and a preparation process thereof, so as to solve the problems raised in the above background art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: A carbon fiber composite material for a notebook computer shell, comprising a carbon fiber layer and a resin layer; the resin layer is disposed on the upper surface and the lower surface of the carbon fiber layer;

[0005] The carbon fiber layer is obtained by coating one or more layers of carbon fiber cloth with an epoxy resin composition and curing.

[0006] Further, the material of the resin layer is one or a mixture of more of PC (polycarbonate), ABS (acrylonitrile-butadiene-styrene copolymer), PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), and PU (polyurethane).

[0007] Further, the thickness of the carbon fiber cloth is 0.11 - 0.39 mm, and the gram weight is 110 - 360 g / m 2 .

[0008] Further, the thickness of the resin layer decreases stepwise from the outside to the inside, and the average thickness is 0.15 - 0.20 mm;

[0009] The middle of the resin layer is the key area, and the thickness is 0.10 - 0.25 mm;

[0010] The thickness of the periphery of the resin layer is 0.20 - 0.36 mm.

[0011] Furthermore, the thickness of the carbon fiber composite material is 1.2 - 4.4 mm.

[0012] A preparation process of a carbon fiber composite material for a notebook computer shell includes the following processes:

[0013] Lay the carbon fiber cloth flat in the mold, coat it with the epoxy resin composition, and pre-cure it to form a pre-cured carbon fiber layer;

[0014] Inject the polyurethane resin successively onto the upper and lower surfaces of the pre-cured carbon fiber layer to form a resin layer; perform molding under pressure to form a carbon fiber layer, and obtain the carbon fiber composite material.

[0015] Furthermore, before coating the epoxy resin composition, heat the carbon fiber cloth to 90 - 130 °C;

[0016] After coating, the epoxy resin composition flows and infiltrates the carbon fiber cloth;

[0017] The pre-curing process conditions are: temperature 90 - 100 °C, duration 30 - 60 min.

[0018] Furthermore, the molding under pressure process conditions are: molding under pressure temperature 95 - 120 °C, molding under pressure duration 80 - 100 min, molding under pressure pressure 0.5 - 1.2 MPa.

[0019] Furthermore, the epoxy resin composition includes the following mass components: 12 - 18 parts of modified epoxy resin and 2 - 6 parts of curing agent;

[0020] The curing agent is one of diethylaminopropylamine and diethyltoluenediamine;

[0021] The mass ratio of the epoxy resin composition to the carbon fiber is (30 - 46):100.

[0022] In the above technical solution, the epoxy resin composition prepared from the epoxy resin and the curing agent is used to coat and impregnate the carbon fiber cloth, and a carbon fiber layer is formed by compounding, making it have the advantages of light weight, high strength, fast heat dissipation, and good shielding effect. And resin layers with high toughness are provided on the upper and lower surfaces of the carbon fiber layer, which helps to improve the impact resistance of the prepared carbon fiber composite material. In the plane direction, the thickness of the outer circle of the resin layer is relatively high, which helps to prevent the corners of the prepared notebook computer shell from being crushed when it falls.

[0023] Furthermore, the modified epoxy resin is prepared by the following process:

[0024] S1. Heat the diisocyanate to 80 - 85 °C, slowly add the polyglycol, and react for 100 - 150 min; wash and dry to obtain the long-chain diisocyanate;

[0025] S2. Mix the long-chain diisocyanate and hydroxyethyl acrylate, heat up to 85 - 90 °C, and react for 150 - 200 min; wash and dry to obtain unsaturated isocyanate;

[0026] S3. Mix the unsaturated isocyanate and epoxy resin, heat up to 85 - 90 °C, and react for 5 - 6 h; obtain unsaturated epoxy resin;

[0027] S4. Dissolve the monomer and initiator in acetone, add the unsaturated epoxy resin and mix, then remove acetone by vacuum distillation; place it in a rheometer, and react at a temperature of 172 - 178 °C for 6 - 8 min to obtain modified epoxy resin.

[0028] Further, in S1, the diisocyanate is one of isophorone diisocyanate, toluene diisocyanate, 1,6 - hexamethylene diisocyanate, methylene diisocyanate, trimethyl hexamethylene diisocyanate, m - xylylene diisocyanate, tetramethyl diethylene diisocyanate, dodecylbenzene - 2,4 - diisocyanate, 4,4 - diisocyanatodicyclohexylmethane, 1,4 - cyclohexanedimethyl diisocyanate, 1,6 - diisocyanate - 2,2,4 - trimethylhexane;

[0029] The polyol is one or a mixture of polyethylene glycol, polypropylene glycol, hydroxyl - terminated polydimethylsiloxane, polytetrahydrofuran glycol, polycarbonate diol;

[0030] The - NCO / -OH ratio of the diisocyanate and the polyol is 2:1.

[0031] Further, in S2, the - NCO / -OH ratio of the long - chain diisocyanate and hydroxyethyl acrylate is 2:1.

[0032] Further, in S3, the - NCO / -OH ratio of the unsaturated isocyanate and epoxy resin is 1:1.

[0033] Further, in S4, the monomer includes: by mass, 10 parts of polybutadiene, 4 - 6 parts of styrene, 1.5 - 4.4 parts of acrylonitrile;

[0034] The initiator is dicumyl peroxide (DCP);

[0035] The mass ratio of the unsaturated epoxy resin, monomer, and initiator is 100:(9 - 15):(0.15 - 0.25);

[0036] The ratio of the monomer to acetone is 10 g / 10 mL;

[0037] The rotational speed of the rheometer rotor is 40 - 50 rpm.

[0038] In the above technical solution, the epoxy resin is modified as follows: Diisocyanate reacts with polyglycol and hydroxyethyl acrylate in sequence to prepare an isocyanate compound containing allyl group, denoted as unsaturated isocyanate; then the isocyanate in its molecular chain reacts with the hydroxyl group in the epoxy resin to obtain an epoxy resin with unsaturated bonds, denoted as unsaturated epoxy resin; finally, the obtained unsaturated epoxy resin is co-extruded with polybutadiene, styrene and acrylonitrile under the action of an initiator to form a composite epoxy resin with an ABS copolymer molecular structure, so that the toughness, processing performance and electrical properties of the prepared modified epoxy resin are effectively improved, and the impact resistance of the carbon fiber composite material is improved. At the same time, the modified epoxy resin has a higher bonding ability with the carbon fiber cloth and is less likely to be peeled off, which helps to further improve the mechanical properties of the carbon fiber composite material.

[0039] Further, the polyurethane resin is prepared by the following process:

[0040] Mix 1,6-hexamethylene diisocyanate and polycarbonate diol, stir for 30 min in a nitrogen atmosphere; heat to 70 - 75 °C and stir and react for 90 - 120 min; add hydroxyl-terminated polybutadiene and continue to react for 120 - 150 min to obtain a prepolymer;

[0041] Add hydroxyethyl acrylate, chain extender and catalyst, raise the temperature to 80 - 85 °C and react for 30 - 60 min to obtain polyurethane;

[0042] Mix the polyurethane, acrylonitrile, styrene, dodecafluoroheptyl methacrylate and initiator, extrude in a twin-screw extruder, pelletize and dry to obtain the polyurethane resin.

[0043] Further, the polyurethane resin is prepared from the following mass components: 17.6 - 23.9 parts of 1,6-hexamethylene diisocyanate, 13 - 18 parts of hydroxyl-terminated polybutadiene, 10 - 20 parts of polycarbonate diol, 1 - 2 parts of hydroxyethyl acrylate, 7.2 - 9.0 parts of chain extender; 3 - 5 parts of acrylonitrile, 1 - 2 parts of styrene, 2.4 - 3.0 parts of dodecafluoroheptyl methacrylate;

[0044] Further, the chain extender is one of methylpropanediol, 2,3-butanediol, 1,4-butanediol, ethylene glycol;

[0045] The catalyst is dibutyltin dilaurate, and the dosage is 0.13 - 0.17 wt% of the total mass of the polyurethane material system;

[0046] The initiator is dicumyl peroxide, and the dosage is 0.5 - 1.0 wt% of the total mass of the polyurethane resin material system.

[0047] In the extrusion process, the extrusion temperature is 185 - 235°C, and the twin-screw rotation speed is 100 - 120 r / min.

[0048] In the above technical solution, the prepolymerization method is adopted. Under the action of a catalyst, diisocyanate reacts with diol to prepare a prepolymer of polyurethane. Its degree of polymerization is closer, and the molecular arrangement tends to be orderly. Then a chain extender is added to synthesize polyurethane, thereby obtaining a polyurethane with a more regular and orderly molecular structure. The diol is polycarbonate diol and hydroxyl-terminated polybutadiene, which helps the polyurethane resin to have good heat resistance, impact resistance, wear resistance, mechanical properties and processing properties.

[0049] Hydroxyethyl acrylate is added in the later stage of the polyurethane prepolymerization reaction to introduce an allyl double bond, enabling the prepared polyurethane to be co-extruded with acrylonitrile, styrene, and dodecafluorooctyl methacrylate, further improving the corrosion resistance and heat resistance of the polyurethane, increasing the water contact angle of the resin layer, improving the water resistance, and preparing a polyurethane resin with higher strength and heat resistance and the resin layer thereof; and the resin layer has a partial molecular chain structure similar to that of the carbon fiber layer, improving the bonding strength between the two, enhancing the strength and toughness of the prepared carbon fiber composite material, and alleviating the phenomenon of dropping and breaking.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0051] A carbon fiber composite material for a notebook computer shell and its preparation process described in the present invention, through an epoxy resin composition prepared from an epoxy resin and a curing agent, coats and impregnates a carbon fiber cloth to form a carbon fiber layer, making it have the advantages of light weight, high strength, fast heat dissipation, and good shielding effect. And resin layers with high toughness are provided on the upper and lower surfaces of the carbon fiber layer, which helps to improve the impact resistance of the prepared carbon fiber composite material. Detailed implementation manners

[0052] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] In the following detailed implementation manners,

[0054] Carbon fiber cloth: CO6644B, with a thickness of 0.3 mm and a grammage of 317 g / m2, sourced from Toray Industries, Inc., Japan;

[0055] The thickness of the resin layer decreases stepwise from the outside to the inside, with a thickness of 0.10 mm in the key area; the outer thickness of the resin layer is 0.20 mm;

[0056] Polyethylene glycol: average number-average molecular weight of 2000, sourced from Sigma-Aldrich Shanghai Trading Co., Ltd.;

[0057] Polytetrahydrofuran diol: average number-average molecular weight of 2000, sourced from Sigma-Aldrich Shanghai Trading Co., Ltd.;

[0058] Hydroxyl-terminated polydimethylsiloxane: average number-average molecular weight of 550, sourced from Sigma-Aldrich Shanghai Trading Co., Ltd.;

[0059] Epoxy resin: EL127, sourced from Nan Ya Plastics Corporation, Ltd.;

[0060] Polybutadiene: B-1000, sourced from Nippon Soda Co., Ltd.;

[0061] Hydroxyl-terminated polybutadiene: JP-200, sourced from Nippon Soda Co., Ltd.;

[0062] Polycarbonate diol: SYHP1000, sourced from Shanghai Shuyu Chemical Co., Ltd.;

[0063] All "parts" hereinafter are by mass.

[0064] Example 1: A preparation process of a carbon fiber composite material for a laptop computer shell, comprising the following processes:

[0065] Step 1, prepare an epoxy resin composition:

[0066] S1. Heat isophorone diisocyanate to 80 °C, slowly add polyethylene glycol, and react for 150 min; wash and dry to obtain a long-chain diisocyanate; the -NCO / -OH ratio of isophorone diisocyanate to polyethylene glycol is 2:1;

[0067] S2. Mix the long-chain diisocyanate and hydroxyethyl acrylate, raise the temperature to 85 °C, and react for 200 min; wash and dry to obtain an unsaturated isocyanate; the -NCO / -OH ratio of the long-chain diisocyanate to hydroxyethyl acrylate is 2:1;

[0068] S3. Mix the unsaturated isocyanate and epoxy resin, raise the temperature to 85 °C, and react for 6 h; obtain an unsaturated epoxy resin; the -NCO / -OH ratio of the unsaturated isocyanate to epoxy resin is 1:1;

[0069] S4. Dissolve the monomer, initiator diisopropylbenzene peroxide in acetone, add unsaturated epoxy resin and mix, then remove acetone by vacuum distillation. Place it in a rheometer and carry out a mixing reaction at 172 °C for 8 min with a rheometer rotor speed of 40 rpm to obtain modified epoxy resin. The monomer includes 10 parts of polybutadiene, 4 parts of styrene, and 1.5 parts of acrylonitrile. The ratio of the monomer to acetone is 10 g / 10 mL. The mass ratio of the unsaturated epoxy resin, monomer, and initiator is 100:9:0.15.

[0070] S5. Mix 12 parts of the modified epoxy resin and 4 parts of the curing agent diethylaminopropylamine to obtain an epoxy resin composition.

[0071] Step 2. Prepare polyurethane resin:

[0072] Mix 1,6 - hexamethylene diisocyanate and polycarbonate diol, stir for 30 min in a nitrogen atmosphere. Heat to 70 °C and stir and react for 120 min. Add hydroxyl - terminated polybutadiene and continue to react for 150 min to obtain a prepolymer. Add hydroxyethyl acrylate, hydroxyethyl acrylate, chain extender methylpropanediol, and 0.13 wt% catalyst dibutyltin dilaurate, raise the temperature to 80 °C, and react for 60 min to obtain polyurethane.

[0073] Mix the polyurethane, acrylonitrile, styrene, dodecafluorooctyl methacrylate, and 0.5 wt% initiator diisopropylbenzene peroxide, and extrude them in a twin - screw extruder at an extrusion temperature of 185 - 235 °C and a twin - screw speed of 100 r / min. Pelletize and dry to obtain polyurethane resin. The polyurethane resin is prepared from the following mass components: 17.6 parts of 1,6 - hexamethylene diisocyanate, 13 parts of hydroxyl - terminated polybutadiene, 10 parts of polycarbonate diol, 1 part of hydroxyethyl acrylate, 7.2 parts of chain extender; 3 parts of acrylonitrile, 1 part of styrene, 2.4 parts of dodecafluorooctyl methacrylate.

[0074] Step 3. Prepare carbon fiber composite material:

[0075] Lay the carbon fiber cloth flat in a mold, heat to 90 °C, coat the 90 °C epoxy resin composition on the surface of the carbon fiber, carry out casting, and infiltrate the carbon fiber cloth. Repeat the above operation 3 times. Pre - cure to form a pre - cured carbon fiber layer. The pre - curing process conditions are: temperature 90 °C, duration 60 min. The mass ratio of the epoxy resin to the carbon fiber is 30:100.

[0076] Inject the polyurethane resin successively on the upper and lower surfaces of the pre - cured carbon fiber layer to form a resin layer. Carry out molding. The molding process conditions are: molding temperature 95 °C, molding duration 100 min, molding pressure 0.5 MPa, to form a carbon fiber layer and obtain a carbon fiber composite material.

[0077] Example 2: A preparation process of a carbon fiber composite material for a laptop computer shell, comprising the following processes:

[0078] Step 1, prepare an epoxy resin composition:

[0079] S1. Heat 1,6 - hexamethylene diisocyanate to 82°C, slowly add polytetrahydrofuran diol, and react for 120 min; wash and dry to obtain a long - chain diisocyanate; the - NCO / -OH ratio of 1,6 - hexamethylene diisocyanate to polytetrahydrofuran diol is 2:1;

[0080] S2. Mix the long - chain diisocyanate and hydroxyethyl acrylate, raise the temperature to 88°C, and react for 180 min; wash and dry to obtain an unsaturated isocyanate; the - NCO / -OH ratio of the long - chain diisocyanate to hydroxyethyl acrylate is 2:1;

[0081] S3. Mix the unsaturated isocyanate and epoxy resin, raise the temperature to 88°C, and react for 5.5 h; obtain an unsaturated epoxy resin; the - NCO / -OH ratio of the unsaturated isocyanate to epoxy resin is 1:1;

[0082] S4. Dissolve the monomer, initiator diisopropylbenzene peroxide in acetone, add the unsaturated epoxy resin and mix, and remove acetone by reduced pressure distillation; place it in a rheometer, and at a temperature of 175°C, mix and react for 7 min, with the rheometer rotor speed of 45 rpm to obtain a modified epoxy resin; the monomer includes 10 parts of polybutadiene, 5 parts of styrene, and 3 parts of acrylonitrile; the ratio of the monomer to acetone is 10 g / 10 mL; the mass ratio of the unsaturated epoxy resin, monomer, and initiator is 100:12:0.20;

[0083] S5. Mix 15 parts of the modified epoxy resin and 4 parts of the curing agent diethyltoluenediamine to obtain an epoxy resin composition;

[0084] Step 2, prepare a polyurethane resin:

[0085] Mix 1,6 - hexamethylene diisocyanate and polycarbonate diol, and stir for 30 min in a nitrogen atmosphere; heat to 72 °C and stir - react for 105 min; add hydroxyl - terminated polybutadiene and continue to react for 135 min to obtain a prepolymer; add hydroxyethyl acrylate, chain extender 2,3 - butanediol, and 0.15 wt% catalyst dibutyltin dilaurate, raise the temperature to 82 °C, and react for 45 min to obtain a polyurethane; mix the polyurethane, acrylonitrile, styrene, dodecafluorooctyl methacrylate, and 0.8 wt% initiator diisopropylbenzene peroxide, and extrude in a twin - screw extruder. The extrusion temperature is 185 - 235 °C, and the twin - screw rotation speed is 110 r / min; pelletize and dry to obtain a polyurethane resin; the polyurethane resin is prepared from the following mass components: 20.8 parts of 1,6 - hexamethylene diisocyanate, 15.5 parts of hydroxyl - terminated polybutadiene, 15 parts of polycarbonate diol, 1.5 parts of hydroxyethyl acrylate, 8.1 parts of chain extender; 4 parts of acrylonitrile, 1.5 parts of styrene, 2.7 parts of dodecafluorooctyl methacrylate;

[0086] Step 3: Prepare a carbon fiber composite material:

[0087] Lay the carbon fiber cloth flat in a mold, heat to 110 °C, coat the 90 °C epoxy resin composition on the surface of the carbon fiber, cast, and infiltrate the carbon fiber cloth. Repeat the above operations 3 times; pre - cure to form a pre - cured carbon fiber layer. The pre - curing process conditions are: temperature 95 °C, duration 45 min; the mass ratio of epoxy resin to carbon fiber is 38:100;

[0088] Inject the polyurethane resin successively on the upper and lower surfaces of the pre - cured carbon fiber layer to form a resin layer; perform compression molding. The compression molding process conditions are: compression molding temperature 110 °C, compression molding duration 90 min, compression molding pressure 0.8 MPa, to form a carbon fiber layer and obtain a carbon fiber composite material.

[0089] Example 3: A preparation process of a carbon fiber composite material for a laptop computer shell, including the following processes:

[0090] Step 1: Prepare an epoxy resin composition:

[0091] S1: Heat 1,4 - cyclohexanedimethylene diisocyanate to 85 °C, slowly add hydroxyl - terminated polydimethylsiloxane, and react for 100 min; wash and dry to obtain a long - chain diisocyanate; the - NCO / -OH ratio of 1,4 - cyclohexanedimethylene diisocyanate to hydroxyl - terminated polydimethylsiloxane is 2:1;

[0092] S2: Mix the long - chain diisocyanate and hydroxyethyl acrylate, raise the temperature to 90 °C, and react for 150 min; wash and dry to obtain an unsaturated isocyanate; the - NCO / -OH ratio of the long - chain diisocyanate to hydroxyethyl acrylate is 2:1;

[0093] S3. Mix the unsaturated isocyanate and epoxy resin, heat up to 90 °C, and react for 5 h to obtain unsaturated epoxy resin. The -NCO / -OH ratio of the unsaturated isocyanate to the epoxy resin is 1:1.

[0094] S4. Dissolve the monomer and the initiator dicumyl peroxide in acetone, add the unsaturated epoxy resin and mix, then remove acetone by vacuum distillation. Place it in a rheometer, and at a temperature of 178 °C, mix and react for 6 min with a rheometer rotor speed of 50 rpm to obtain modified epoxy resin. The monomer includes 10 parts of polybutadiene, 6 parts of styrene, and 4.4 parts of acrylonitrile. The ratio of the monomer to acetone is 10 g / 10 mL. The mass ratio of the unsaturated epoxy resin, the monomer, and the initiator is 100:15:0.25.

[0095] S5. Mix 18 parts of the modified epoxy resin and 4 parts of the curing agent diethylaminopropylamine to obtain an epoxy resin composition.

[0096] Step 2. Prepare polyurethane resin:

[0097] Mix 1,6 - hexamethylene diisocyanate and polycarbonate diol, stir in a nitrogen atmosphere for 30 min, heat to 75 °C, and stir and react for 90 min. Add hydroxyl - terminated polybutadiene and continue to react for 120 min to obtain a prepolymer. Add 2 - hydroxyethyl acrylate, chain extender 1,4 - butanediol, and 0.17 wt% catalyst dibutyltin dilaurate, heat up to 85 °C, and react for 30 min to obtain polyurethane. Mix the polyurethane, acrylonitrile, styrene, dodecafluorooctyl methacrylate, and 1.0 wt% initiator dicumyl peroxide, and extrude in a twin - screw extruder with an extrusion temperature of 185 - 235 °C and a twin - screw speed of 120 r / min. Pelletize and dry to obtain polyurethane resin. The polyurethane resin is prepared from the following mass components: 23.9 parts of 1,6 - hexamethylene diisocyanate, 18 parts of hydroxyl - terminated polybutadiene, 20 parts of polycarbonate diol, 2 parts of 2 - hydroxyethyl acrylate, 9.0 parts of chain extender; 5 parts of acrylonitrile, 2 parts of styrene, 3.0 parts of dodecafluorooctyl methacrylate.

[0098] Step 3. Prepare carbon fiber composite material:

[0099] Lay the carbon fiber cloth flat in a mold, heat to 130 °C, coat the epoxy resin composition at 90 °C on the surface of the carbon fiber, perform casting, and infiltrate the carbon fiber cloth. Repeat the above operations 3 times. Pre - cure to form a pre - cured carbon fiber layer. The pre - curing process conditions are: temperature 100 °C, duration 30 min. The mass ratio of the epoxy resin to the carbon fiber is 46:100.

[0100] Inject polyurethane resin onto the upper and lower surfaces of the pre-cured carbon fiber layer in sequence to form a resin layer; perform compression molding, and the compression molding process conditions are: compression molding temperature 120°C, compression molding duration 80 min, compression molding pressure 0.5 MPa, to form a carbon fiber layer and obtain a carbon fiber composite material.

[0101] Comparative Example 1: A preparation process of a carbon fiber composite material for a notebook computer shell, including the following processes:

[0102] Step 1: Prepare an epoxy resin composition:

[0103] S1. Mix isophorone diisocyanate and hydroxyethyl acrylate, heat up to 85°C, and react for 200 min; wash and dry to obtain unsaturated isocyanate; the -NCO / -OH ratio of isophorone diisocyanate and hydroxyethyl acrylate is 2:1;

[0104] S2. Mix the unsaturated isocyanate and epoxy resin, heat up to 85°C, and react for 6 h; obtain unsaturated epoxy resin; the -NCO / -OH ratio of the unsaturated isocyanate and epoxy resin is 1:1;

[0105] S3. Dissolve the monomer, initiator dicumyl peroxide in acetone, add the unsaturated epoxy resin and mix, and remove acetone by reduced pressure distillation; place it in a rheometer, and at a temperature of 172°C, mix and react for 8 min, and the rotational speed of the rheometer rotor is 40 rpm to obtain a modified epoxy resin; the monomer includes 10 parts of polybutadiene, 4 parts of styrene, and 1.5 parts of acrylonitrile; the ratio of the monomer to acetone is 10 g / 10 mL; the mass ratio of the unsaturated epoxy resin, monomer, and initiator is 100:9:0.15;

[0106] S4. Mix 12 parts of the modified epoxy resin and 4 parts of the curing agent diethylaminopropylamine to obtain an epoxy resin composition;

[0107] Steps 2 - 3 are the same as those in Example 1 to obtain a carbon fiber composite material.

[0108] Comparative Example 2: A preparation process of a carbon fiber composite material for a notebook computer shell, including the following processes:

[0109] Step 1: Prepare an epoxy resin composition:

[0110] S1. Mix isophorone diisocyanate and hydroxyethyl acrylate, heat up to 85°C, and react for 200 min; wash and dry to obtain unsaturated isocyanate; the -NCO / -OH ratio of isophorone diisocyanate and hydroxyethyl acrylate is 2:1;

[0111] S2. Mix the unsaturated isocyanate and epoxy resin, heat up to 85 °C, and react for 6 h to obtain unsaturated epoxy resin; the -NCO / -OH ratio of the unsaturated isocyanate to the epoxy resin is 1:1.

[0112] S3. Mix the unsaturated epoxy resin and the initiator dicumyl peroxide; place them in a rheometer, and at a temperature of 172 °C, mix and react for 8 min with a rheometer rotor speed of 40 rpm to obtain modified epoxy resin; the monomers include 10 parts of polybutadiene, 4 parts of styrene, and 1.5 parts of acrylonitrile; the mass ratio of the unsaturated epoxy resin to the initiator is 100:0.15.

[0113] S4. Mix 12 parts of the modified epoxy resin and 4 parts of the curing agent diethylaminopropylamine to obtain an epoxy resin composition.

[0114] Steps 2-3 are the same as in Example 1 to obtain a carbon fiber composite material.

[0115] Comparative Example 3: A preparation process of a carbon fiber composite material for a laptop computer shell, including the following processes:

[0116] Step 1. Prepare an epoxy resin composition: Mix 12 parts of epoxy resin and 6 parts of the curing agent diethylaminopropylamine to obtain an epoxy resin composition.

[0117] Steps 2-3 are the same as in Example 1 to obtain a carbon fiber composite material.

[0118] Comparative Example 4: A preparation process of a carbon fiber composite material for a laptop computer shell, including the following processes:

[0119] Step 2. Prepare polyurethane resin:

[0120] Mix 1,6-hexamethylene diisocyanate and polycarbonate diol, stir for 30 min in a nitrogen atmosphere; heat to 70 °C and stir and react for 150 min to obtain a prepolymer; add hydroxyethyl acrylate, chain extender methylpropanediol, and 0.13 wt% catalyst dibutyltin dilaurate, heat up to 80 °C, and react for 60 min to obtain polyurethane.

[0121] Mix the polyurethane, acrylonitrile, styrene, dodecafluorooctyl methacrylate, and 0.5 wt% initiator dicumyl peroxide, and extrude in a twin-screw extruder at an extrusion temperature of 185-235 °C and a twin-screw speed of 100 r / min; pelletize and dry to obtain polyurethane resin; the polyurethane resin is prepared from the following mass components: 17.6 parts of 1,6-hexamethylene diisocyanate, 20 parts of polycarbonate diol, 1 part of hydroxyethyl acrylate, 7.2 parts of chain extender; 3 parts of acrylonitrile, 1 part of styrene, 2.4 parts of dodecafluorooctyl methacrylate.

[0122] Steps 1 and 3 are the same as those in Comparative Example 3 to obtain a carbon fiber composite material.

[0123] Comparative Example 5: A preparation process of a carbon fiber composite material for a laptop computer shell, including the following processes:

[0124] Step 2, prepare polyurethane resin:

[0125] Mix 1,6 - hexamethylene diisocyanate and polycarbonate diol, stir for 30 min in a nitrogen atmosphere; heat to 70 °C and stir - react for 150 min to obtain a prepolymer; add hydroxyethyl acrylate, chain extender methylpropanediol, and 0.13 wt% catalyst dibutyltin dilaurate, raise the temperature to 80 °C, and react for 60 min to obtain polyurethane resin; the polyurethane resin is prepared from the following mass components: 17.6 parts of 1,6 - hexamethylene diisocyanate, 23 parts of polycarbonate diol, and 7.2 parts of chain extender;

[0126] Steps 1 and 3 are the same as those in Comparative Example 3 to obtain a carbon fiber composite material.

[0127] Experiment: Take the carbon fiber composite materials obtained in Examples 1 - 3 and Comparative Examples 1 - 5 to prepare specimens, and detect and record the test results of their properties respectively:

[0128] Taking GB / T 1447 as the reference standard, use an electronic universal testing machine to test the tensile properties of the specimens, with a tensile rate of 2 mm / min;

[0129] Taking GB / T 1449 as the reference standard, use an electronic universal testing machine to test the three - point bending properties of the specimens;

[0130] Taking ASTM D7136 as the reference standard, use an electronic universal testing machine to test the impact resistance of the specimens, with an impact object mass of 11.2 kg and a punch shape of a hemisphere.

[0131] Tensile strength (MPa) Flexural strength (MPa) <![CDATA[Impact toughness (kJ / m 2 ) <!-- 7 -->]]> Example 1 235.3 260.4 146 Example 2 241.8 267.9 152 Example 3 248.2 275.6 159 Comparative Example 1 227.2 252.3 140 Comparative Example 2 198.5 227.8 114 Comparative Example 3 190.7 220.1 108 Comparative Example 4 165.3 207.6 63 Comparative Example 5 156.4 196.9 59

[0132] According to the data in the above table, the following conclusions can be clearly obtained:

[0133] The carbon fiber composite materials obtained in Examples 1 - 3 are compared with those obtained in Comparative Examples 1 - 5. From the test results,

[0134] 1. Compared with the comparative examples, the carbon fiber composite materials obtained in Examples 1 - 3 have higher tensile strength, bending strength, and impact toughness data. This fully shows that the present invention has achieved an improvement in the mechanical properties and impact resistance of the prepared carbon fiber composite materials.

[0135] 2. Compared with Example 1, in the epoxy resin composition of Comparative Example 1, the modified epoxy resin is prepared from isophorone diisocyanate, hydroxyethyl acrylate, epoxy resin and monomer, and polyethylene glycol is not provided; in the epoxy resin composition of Comparative Example 2, the modified epoxy resin is prepared from isophorone diisocyanate, hydroxyethyl acrylate and epoxy resin, and polyethylene glycol and monomer are not provided; the epoxy resin composition of Comparative Example 3 consists of epoxy resin and curing agent. Compared with Comparative Example 3, terminal hydroxyl polybutadiene is not provided in the polyurethane resin preparation components of Comparative Example 4; terminal hydroxyl polybutadiene and vinyl monomer are not provided in the polyurethane resin preparation components of Comparative Example 5. For the carbon fiber composites obtained in Comparative Examples 1-5, the data of tensile strength, flexural strength and impact toughness decreased. It can be seen that the setting of the components and processes of the carbon fiber composites of the present invention can promote the improvement of their mechanical properties and impact resistance.

[0136] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0137] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A process for preparing a carbon fiber composite material for a laptop computer shell, characterized in that: Including the following processes: Taking carbon fiber cloth and laying it flat in a mold, coating it with an epoxy resin composition, and precuring it to form a precured carbon fiber layer; injecting polyurethane resin onto the upper surface and the lower surface of the pre-cured carbon fiber layer in sequence to form a resin layer; Molding to form a carbon fiber layer to obtain a carbon fiber composite material; The epoxy resin composition comprises the following components by mass: 12 to 18 parts of modified epoxy resin and 2 to 6 parts of curing agent; The modified epoxy resin is prepared by the following process: Heat the diisocyanate to 80-85°C, slowly add the polyglycol, and react for 100-150 minutes to obtain a long-chain diisocyanate; Mix long-chain diisocyanate and hydroxyethyl acrylate, raise the temperature to 85-90°C, and react for 150-200 minutes to obtain unsaturated isocyanate; Mix unsaturated isocyanate and epoxy resin, raise the temperature to 85-90°C, and react for 5-6 hours to obtain unsaturated epoxy resin; The monomer and the initiator are dissolved in acetone, and unsaturated epoxy resin is added and mixed, and distilled under reduced pressure; the mixture is placed in a rheometer, and mixed and reacted for 6 to 8 minutes at a temperature of 172 to 178° C. to obtain a modified epoxy resin.

2. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 1, characterized in that: The thickness of the resin layer decreases stepwise from the outside to the inside, with an average thickness of 0.15 to 0.20 mm; The middle of the resin layer is a key area with a thickness of 0.10 to 0.25 mm; the outer thickness of the resin layer is 0.20 to 0.36 mm.

3. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 1, characterized in that: The diisocyanate is one of isophorone diisocyanate, toluene diisocyanate, 1,6-hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, meta-xylylene diisocyanate, tetramethyl dimethylene diisocyanate, dodecylbenzene-2,4-diisocyanate, 4,4-diisocyanate dicyclohexylmethane, 1,4-cyclohexane dimethyl diisocyanate, and 1,6-diisocyanate-2,2,4-trimethylhexane; The polyglycol is a mixture of one or more of polyethylene glycol, polypropylene glycol, hydroxyl-terminated polydimethylsiloxane, polytetramethylene glycol, and polycarbonate glycol.

4. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 1, characterized in that: The monomers include: by mass, 10 parts of polybutadiene, 4 to 6 parts of styrene, and 1.5 to 4.4 parts of acrylonitrile; The mass ratio of unsaturated epoxy resin, monomer and initiator is 100:(9-15):(0.15-0.25).

5. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 1, characterized in that: The polyurethane resin is prepared by the following process: Mix 1,6-hexamethylene diisocyanate and polycarbonate diol, stir for 30 minutes in a nitrogen atmosphere; heat to 70-75°C, stir and react for 90-120 minutes; add hydroxyl-terminated polybutadiene, and continue to react for 120-150 minutes to obtain a prepolymer; Add hydroxyethyl acrylate, chain extender and catalyst, raise the temperature to 80-85°C, react for 30-60 minutes to obtain polyurethane; The polyurethane, acrylonitrile, styrene, dodecafluoroheptyl methacrylate and an initiator are mixed, extruded in a twin-screw extruder, granulated and dried to obtain a polyurethane resin.

6. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 5, characterized in that: The polyurethane resin is prepared from the following mass components: 17.6-23.9 parts of 1,6-hexamethylene diisocyanate, 13-18 parts of hydroxy-terminated polybutadiene, 10-20 parts of polycarbonate diol, 1-2 parts of hydroxyethyl acrylate, 7.2-9.0 parts of chain extender; 3-5 parts of acrylonitrile, 1-2 parts of styrene, 2.4-3.0 parts of dodecafluoroheptyl methacrylate; The chain extender is one of methyl propylene glycol, 2,3-butanediol, 1,4-butanediol and ethylene glycol.

7. The process for preparing a carbon fiber composite material for a notebook computer shell according to claim 5, characterized in that: In the extrusion process, the extrusion temperature is 185-235°C, and the twin-screw speed is 100-120r / min.

8. A carbon fiber composite material for a laptop computer shell, characterized in that: The method is prepared by the preparation process described in any of claims 1 to 7.