KR101089060B1 - Fabrication method for high performance carborn fibers-reinforced composites by using the optimized condition of burdening - Google Patents

Abstract

The present invention relates to a method for producing a high strength carbon fiber reinforced composite material using optimized curing conditions, and more particularly, to control the room temperature viscosity of a thermosetting polymer resin solution, and to a semi-cured state through pre-heating of pregreg It relates to a method for producing a high-strength carbon fiber reinforced composite material according to (b-stage) and optimized curing conditions, and to a high-strength carbon fiber reinforced composite material produced by the above method.

The high-strength carbon fiber composite material prepared according to the present invention is a thermosetting polymer resin solution when manufactured by a vacuum bag molding method because the optimum semi-cured state (b-stage) is set through the preheat treatment of prepreg. It is possible to prevent the lowering of the physical properties of the composite material caused by the viscosity decrease of the result, it is possible to manufacture a high-strength carbon fiber reinforced composite material having high mechanical properties.

Carbon fiber reinforced composite, thermoset, semi-hardened, vacuum bag molding, high strength

Description

Manufacturing method of high strength carbon fiber reinforced composite material using optimized hardening condition {FABRICATION METHOD FOR HIGH PERFORMANCE CARBORN FIBERS-REINFORCED COMPOSITES BY USING THE OPTIMIZED CONDITION OF BURDENING}

The present invention relates to a method for producing a high strength carbon fiber reinforced composite material using optimized curing conditions, and more particularly, to control the room temperature viscosity of a thermosetting polymer resin solution, and to a semi-cured state through pre-heating of pregreg It relates to a method for producing a high-strength carbon fiber reinforced composite material according to (b-stage) and optimized curing conditions, and to a high-strength carbon fiber reinforced composite material produced by the above method.

Carbon fibers-reinforced composites have been used primarily in the aerospace and aerospace industries, as well as in the highly technical fields related to nuclear and general technology, as well as in transportation, such as bearings, gears, cams and automotive fuselage. Its application scope has been attracting attention as a promising new material because it has been extended to various fields such as electricity, electronics, materials, civil engineering and building materials, automobiles, ships, military equipment, and sports goods.

The carbon fiber reinforced composite material has an autoclave or vacuum bag molding method because the presence of air bubbles remaining inside during manufacture makes a critical effect on the mechanical properties of the final composite material. The pressure difference in the curing process is used to remove residual internal bubbles.

In addition, when the thermosetting resin is used as a matrix, the curing temperature is generally 150 ° C. or higher, and as a result, the viscosity of the internal resin becomes very low. This lowered resin is discharged to the outside through the breather due to the pressure difference, and if the excess resin escapes, it leads to the deterioration of the physical properties of the composite material. to prevent the removal of excessive resin during high temperature curing.

In addition, when the carbon fiber is a long-fiber type carbon fiber, the carbon fiber is impregnated with a resin such as an epoxy resin by a filament winding method, semi-cured, and then cured by cutting to a certain size. However, it is very difficult to identify the semi-cured state because certain resins exhibit the properties of pseudo plastics that do not exhibit adhesion at room temperature. In the case of misdiagnosing the semi-cured state as described above and performing high temperature curing, the viscosity of the resin decreases rapidly during curing, resulting in a decrease in physical properties due to excessive removal of the internal resin.

Therefore, it is required to develop the optimal curing conditions according to the characteristics of the polymer resin solution used in the production of carbon fiber composite materials.

Accordingly, the present invention has been made to solve the above problems, the main object of the present invention is a vacuum bag for improving the mechanical strength by inducing a semi-cured state of the thermosetting polymer resin solution in the method of manufacturing a carbon fiber reinforced composite material The present invention provides a method for producing a carbon fiber reinforced composite material using a vacuum bag molding method.

In order to achieve the above object, the present invention comprises the steps of (1) preparing a thermosetting polymer resin solution by mixing a polymer resin, a curing agent and an accelerator; (2) impregnating carbon fibers in the thermosetting polymer resin solution to prepare a prepreg; (3) preheating the prepreg; (4) stacking the heat treated prepreg; And (5) compressing the laminated prepreg to thermally harden it under vacuum, thereby providing a method of manufacturing a high strength carbon fiber reinforced composite material using a vacuum bag molding method.

In the present invention, the thermosetting polymer resin solution is mixed with 50 to 150 parts by weight of a curing agent, 0.1 to 5.0 parts by weight of a accelerator relative to 100 parts by weight of the polymer resin, characterized in that the room temperature (30 ℃) viscosity is controlled to 400 to 800 cps , The line heat treatment process is characterized in that it is carried out for 1 minute to 60 minutes in a temperature range of 50 ~ 130 ℃ in an inert atmosphere such as nitrogen, helium, argon at atmospheric pressure.

The present invention also provides a high strength carbon fiber reinforced composite material produced by the above method and improved in mechanical strength.

The mechanical interface strength of the carbon fiber reinforced composite material according to the present invention is characterized in that the 30 ~ 70 MPa.

The high-strength carbon fiber composite material prepared according to the present invention is a thermosetting polymer resin solution when manufactured by a vacuum bag molding method because the optimum semi-cured state (b-stage) is set through the preheat treatment of prepreg. It is possible to prevent the lowering of the physical properties of the composite material caused by the viscosity decrease of the result, it is possible to manufacture a high-strength carbon fiber reinforced composite material having high mechanical properties.

In addition, the high-strength carbon fiber composite material of the present invention is very excellent in mechanical properties compared to the conventional carbon fiber composite material can be usefully used throughout the industry.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for producing a high strength carbon fiber reinforced composite material using vacuum bag molding method.

Specifically, the present invention comprises the steps of (1) preparing a thermosetting polymer resin solution by mixing a polymer resin, a curing agent and an accelerator; (2) impregnating carbon fibers in the thermosetting polymer resin solution to prepare a prepreg; (3) preheating the prepreg; (4) stacking the heat treated prepreg; And (5) compressing the stacked prepregs to thermally harden them in vacuo.

In the present invention, the thermosetting polymer resin solution prepared in the step (1) is preferably mixed with 50 to 150 parts by weight of a curing agent, 0.1 to 5.0 parts by weight of a curing agent with respect to 100 parts by weight of the polymer resin, wherein the thermosetting polymer resin solution The room temperature viscosity of is 400 to 800 cps at 30 ℃, the resin content is preferably 50 ± 2% relative to the carbon fiber reinforced composite material finally produced.

In addition, the polymer resin may be used as long as the liquid thermosetting resin, preferably, may include epoxy, phenol, unsaturated polyester, and the like.

In addition, the curing agent used for the thermal curing of the laminated prepreg may be used a commonly used curing agent such as aromatic polyamine-based, aliphatic polyamine-based, acid anhydride-based, preferably MPDA (meta-phenylene diamine), DDS ( Diamino-diphenyl sulfone (DDM), diamino-diphenyl methane (DDM), diethylenetriamine (DETA), triethylenetetramine (TETA), nadic methyl anhydride (NMA), chlorendic anhydride (HET) and methyltetrahydrophthalic anhydride (MTHPA) are preferred. The promoter for promoting is preferably selected from amines, preferably DMP (tris-dimethylaminomethyl phenol) -30 or BMPA (benzyldimethylamine).

In the present invention, the carbon fiber of the step (2) may be used a conventional long-fiber carbon fiber, preferably T100 to T1200, 1K to 24K, PAN-based, Pitch-based, Rayon It is good that it is 1 or more types chosen from system.

In addition, the method of manufacturing the prepreg in the step (2) can be used both uniaxial or multi-axial filament winding, it may further include a predetermined amount of an organic solvent in the resin for easier processability.

In the present invention, in the step (3), the pre-heat treatment process is necessary to secure the optimum radius of the prepreg (b-stage), the pre-heat treatment process is 50 ℃ under normal pressure and inert atmosphere such as nitrogen, helium, argon It is preferable to carry out for 1 to 60 minutes in the temperature range of -130 degreeC. This is because less than one minute does not sufficiently transfer heat into the prepreg, and if it exceeds 60 minutes, excessive hardening may occur.

In the present invention, in the step (5) it is preferable to squeeze the laminated preg using a thermocompressor and then to cure for 1 to 5 hours at 130 ~ 170 ℃ at a pressure of 7 ~ 8 MPa under vacuum. .

In an embodiment of the present invention, the one-way prepreg is laminated, and the stacked prepregs are thermally cured by pressure and heat in a vacuum atmosphere using a thermocompressor, but the present invention is not limited thereto.

The present invention also provides a high strength carbon fiber reinforced composite material produced by the above method.

In the present invention, the mechanical interface strength of the carbon fiber reinforced composite is preferably 30 to 70 MPa.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

Example 1.

In order to manufacture the carbon fiber reinforced composite material of the present invention, the carbon fiber was used 12K unsized% untreated long-fiber carbon fiber (Taekwang Industrial Co., Ltd.), the epoxy resin Epon-826 (Co., Ltd.) Gangnam Hwaseong, Korea) 100 g, the curing agent and accelerator were 50 and 0.1 g each of MTHPA (methyltetrahydrophthalic anhydride; HM2200, Gangnam Hwaseong, Korea) and BDMA (benzyldimethylamine; Gangnam Hwaseong, Korea), respectively. A thermosetting polymer resin solution was prepared.

After impregnating the long-fiber carbon fiber and the thermosetting polymer resin solution to prepare a grip prepreg for 1 minute pre-heat treatment at 50 ℃, one-way prepreg laminated and then laminated prepreg using a thermocompressor It was cured at 150 DEG C for 2 hours under pressure of 7.35 MPa under vacuum atmosphere.

Example 2.

A carbon fiber-reinforced composite material was prepared under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 0.1 g of BDMA and preheated at 70 ° C. for 10 minutes. It was.

Example 3.

A carbon fiber-reinforced composite material was prepared under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 150 g of HN2200, and 0.1 g of BDMA and preheated at 100 ° C. for 30 minutes. It was.

Example 4.

A carbon fiber-reinforced composite material was prepared under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 0.5 g of BDMA. It was.

Example 5.

A carbon fiber-reinforced composite material was manufactured under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 1.0 g of BDMA and preheated at 130 ° C. for 20 minutes. It was.

Example 6.

A carbon fiber-reinforced composite material was manufactured under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 2.0 g of BDMA and preheated at 130 ° C. for 30 minutes. It was.

Example 7.

A carbon fiber-reinforced composite material was prepared under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 5.0 g of BDMA and preheat-treated at 130 ° C. for 60 minutes. It was.

Comparative Example 1.

A carbon fiber-reinforced composite material was prepared under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 30 g of HN2200, and 0.01 g of BDMA and preheated at 130 ° C. for 60 minutes. It was.

Comparative Example 2

 A carbon fiber-reinforced composite material was manufactured under the same conditions as in Example 1, except that the thermosetting polymer resin solution was prepared in a composition of 100 g of Epon-826, 100 g of HN2200, and 2.0 g of BDMA and preheated at 35 ° C. for 60 minutes. It was.

In the present invention, each characteristic value was measured by the following method.

Experimental Example 1. Measurement of room temperature viscosity

The room temperature (30 ° C.) viscosity of the thermosetting polymer resin solutions prepared in Examples and Comparative Examples was measured using a Brookfield viscometer (No. 62 spindle, 30 rpm), and the results are shown in Table 1 below.

Experimental Example 2. Resin Content Measurement

In order to measure the resin content in the carbon fiber-reinforced composite materials prepared in Examples and Comparative Examples, the amount of residual fibers was measured after evaporating all the thermosetting polymer resin solutions in a furnace of nitrogen atmosphere, The limit value of the residual fiber was calculated as the resin content. The results are shown in Table 1 below.

Experimental Example 3. Measurement of Mechanical Strength

The mechanical strength of the carbon fiber reinforced composites prepared in Examples and Comparative Examples was measured using the interlaminar shear stree (ILSS) method, one of the three-point bending strength measurement method, the results are shown in Table 1.

Epon-826
(g) HN2200
(g) BDMA
(g) Heat treatment
Temperature (℃) time
(minute) Room temperature viscosity
(cps) Suzy
Content rate (%) ILSS
(MPa) Example 1 100 50 0.1 50 One 400 38 30 Example 2 100 100 0.1 70 10 450 42 42 Example 3 100 150 0.1 100 30 500 44 48 Example 4 100 100 0.5 130 10 550 47 55 Example 5 100 100 1.0 130 20 630 48 62 Example 6 100 100 2.0 130 30 780 50 70 Example 7 100 100 5.0 130 60 800 52 65 Comparative Example 1 100 30 0.01 130 60 320 12 17 Comparative Example 2 100 100 2.0 35 60 380 15 21

However, the said result is the average of the result measured more than 10 times.

As described above, specific portions of the contents of the present invention have been described in detail, and for those skilled in the art, these specific techniques are merely preferred embodiments, and the scope of the present invention is not limited thereto. Will be obvious. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (12)

(1) preparing a thermosetting polymer resin solution by mixing 50 to 150 parts by weight of the curing agent and 0.1 to 5.0 parts by weight of the accelerator with respect to 100 parts by weight of the polymer resin; (2) Prepreg by impregnating the thermosetting polymer resin solution with one or more long-fiber carbon fibers selected from T100 to T1200, 1K to 24K, PAN system, Pitch system, and Rayon system. Preparing a; (3) preheating the prepreg to a temperature range of 50 to 130 ° C. in an inert atmosphere such as nitrogen, helium, and argon for 1 to 60 minutes; (4) stacking the heat treated prepreg; And (5) compressing the laminated prepreg using a thermocompressor and thermally curing the resin at a pressure of 7 to 8 MPa at 130 to 170 ° C. for 1 to 5 hours under vacuum. The vacuum bag molding includes a vacuum bag molding. molding method, The room temperature viscosity of the thermosetting polymer resin solution is characterized in that 400 to 800cps at 30 ℃, the resin content is high strength carbon fiber reinforced composite material, characterized in that 50 ± 2% to the carbon fiber reinforced composite material finally produced Method of preparation. delete delete delete The method of claim 1, The polymer resin is a manufacturing method characterized in that it uses at least one thermosetting polymer resin selected from epoxy, phenol, or unsaturated polyester. The method of claim 1, The curing agent is a meta-phenylene diamine (MPDA), diamino-diphenyl sulfone (DDS), diamino-diphenyl methane (DDM), diethylenetriamine (DETA), triethylenetetramine (TETA), nadic methyl anhydride (NMA), chlorendic anhydride (HET), MTHPA (methyltetrahydrophthalic anhydride) The production method characterized by using at least one selected from. The method of claim 1, The accelerator is a manufacturing method characterized in that at least one selected from DMP (tris-dimethylaminomethyl phenol) -30 or BMPA (benzyldimethylamine). delete delete delete delete delete