KR101987827B1 - Polymer Composite With Carbon Fiber and Manufacturing Thereof - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a carbon fiber composite material having an elastic layer between carbon fiber layers and having ductility and high strength, and a method of manufacturing the same. (A) 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive A polymer compound layer; And (b) a carbon fiber layer positioned above or above and below the polymer compound.

Description

TECHNICAL FIELD [0001] The present invention relates to a carbon fiber composite material,

The present invention relates to a carbon fiber composite material and a method of manufacturing the same, and more particularly, to a carbon fiber composite material having an elastic layer between carbon fiber layers and having ductility and high strength.

Carbon-carbon composites are widely used for aircraft brake discs and heat-resistant materials because of their excellent friction and abrasion characteristics and thermal shock resistance. The carbon composite material production method can be divided into a step of producing a fiber layer using carbon fiber and a step of densifying the fiber layer.

The process of densifying the fibrous layer is classified into a liquid impregnation method and a chemical vapor infiltration method.

In the liquid phase impregnation method, a fiber layer is impregnated with a resin and the resin is pyrolyzed to form a carbon matrix. The chemical vapor deposition method is a method of impregnating a hydrocarbon gas into a fiber layer and pyrolyzing the hydrocarbon gas to form a carbon matrix.

The chemical vapor infiltration method is divided into an ISOTHERMAL method and a THERMAL GRADIENT method.

The isothermal method pyrolyzes the hydrocarbon gas in a state in which the inner temperature and the outer temperature of the fiber layer become uniform. Therefore, the carbon composite material produced by the isothermal method has uniform thermal conductivity and uniformity of characteristics of the entire carbon matrix. However, in the isothermal method, pyrolysis reaction of hydrocarbon gas occurs simultaneously at the inside and outside of the fiber layer, so that the carbon which is thermally decomposed from the outside without being diffused into the inside of the fiber layer is deposited on the surface of the fiber layer. As a result, the pores on the surface of the fibrous layer are clogged, preventing the hydrocarbon gas from penetrating into the fibrous layer. Therefore, the surface of the fibrous layer should be ground periodically to pierce the clogged pores. When the surface of the fibrous layer is periodically changed, the size of the fibrous layer that can actually make the product is gradually reduced. Also, it takes a lot of time (2 ~ 3 months) to make the carbon composite because it has to drill periodically clogged pores.

The thermal gradient method gives a temperature gradient from the inside to the outside of the fiber layer so that the thermal decomposition reaction of the hydrocarbon gas progresses gradually from the inside to the outside of the fiber layer. Therefore, the pore clogging does not occur, and the surface of the fibrous layer does not have to be periodically ground, and the time (2 to 3 weeks) required to produce the carbon composite material is shortened. However, the thermal gradient method makes it difficult to linearly and precisely determine the thermal gradient, and when the hydrocarbon gas is pyrolyzed, the temperature inside and outside of the fiber layer becomes unstable as in the isothermal method. Therefore, the carbon composite made by the isothermal method has lower thermal conductivity than the carbon composite made by the isothermal method because the characteristics of the entire carbon matrix are not uniform.

However, in the case of the carbon fiber composite material produced as described above, the higher the content of carbon fiber is, the lower the ductility and the toughness of the composite material, the stronger impact may damage the composite material, So that it has a disadvantage that its durability is lower than its strength.

Korean Patent Publication No. 10-2016-0033448 discloses a thermoplastic resin-containing composite material having uniform conductivity and a molded article containing the same. Although the present invention discloses a composite material having carbon nanotubes having a high aspect ratio and having uniform conductivity, it has a problem in that the composite material is simply mixed with the carbon fibers, resulting in deterioration of ductility and ductility of the composite material

Korean Patent No. 10-1437212 discloses a continuous carbon fiber-reinforced thermoplastic composite material excellent in impregnation property and a manufacturing method thereof. In the present invention, the thermoplastic resin is impregnated with continuous carbon fiber which is widened to exhibit a high impregnation property, but the composite material to be produced may lack durability due to lack of ductility and toughness.

Accordingly, the present invention aims to provide a carbon fiber composite material excellent in mechanical properties and a method of manufacturing the same.

(A) 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of a weather resistance improver, , 1 to 20 parts by weight of an additive; And (b) a carbon fiber layer positioned above or above and below the polymer compound.

The synthetic rubber is acrylonitrile butadiene rubber (NBR), and the content of acrylonitrile may be 20 to 60% by weight.

The epoxy resin is a one-component epoxy resin, and may be an acrylonitrile-butadiene rubber-modified epoxy resin.

The filler may include at least one member selected from the group consisting of carbon black, calcium carbonate, silica, and diatomaceous earth.

(I) 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive, Preparing a polymer compound prepreg containing the polymer compound prepreg; (ii) preparing a carbon fiber prepreg by mixing carbon fibers and a thermosetting polymer; And (iii) alternately laminating the carbon fiber prepreg of the step (ii) and the polymer prepreg of the step (i), and then heating and molding the carbon fiber composite material to produce a carbon fiber composite material. ≪ / RTI >

Since the carbon fiber composite material and the manufacturing method thereof according to the present invention include a rubber layer between the carbon fiber layers, a carbon fiber composite material having ductility and toughness unlike the conventional carbon fiber composite material can be provided. Parts, cases, and the like.

1 is a view showing the structure of a carbon fiber composite material according to the present invention.
2 is a photograph showing a carbon fiber composite material molding apparatus of the present invention.
3 is a photograph showing a carbon fiber prepreg according to an embodiment of the present invention.
4 is a view showing a specimen used in the test of ASTM D3163 according to an embodiment of the present invention.
5 is a photograph of a case for a portable communication device made of a carbon fiber composite material according to an embodiment of the present invention.
6 is a cross-sectional view of a case for a portable communication device made of a carbon fiber composite material according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The present invention is capable of various modifications and various embodiments and is intended to illustrate and describe the specific embodiments in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms used in the description are used only to describe certain embodiments and are not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as comprise, having, or the like are intended to designate the presence of stated features, integers, steps, operations, elements, parts or combinations thereof, and may include one or more other features, , But do not preclude the presence or addition of one or more other features, elements, components, components, or combinations thereof.

(A) 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive A polymer compound layer; And (b) a carbon fiber layer positioned above or above and below the polymer compound.

The polymer compound layer is positioned between the carbon fiber layers to absorb impact applied to the carbon fiber layer, and noise and vibration can be reduced. Also, unlike the conventional carbon composite material, since the polymer compound layer is positioned between the carbon fiber layers, the carbon fiber composite material can have ductility and thus the flexural strength is increased.

The polymer compound layer is composed of a thermosetting rubber, and preferably 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of a weather- And 1 to 20 parts by weight of an additive.

The synthetic rubber may be any thermosetting rubber having elasticity as a main component of the polymer compound layer, but it may preferably be a butadiene rubber, more preferably an acrylonitrile butadiene rubber (NBR). The acrylonitrile-butadiene rubber is a copolymer prepared by emulsion polymerization of acrylonitrile and butadiene at a low temperature. The synthetic rubber is excellent in oil resistance and chemical resistance. In the present invention, the content of acrylonitrile is 20 to 60 wt% Preferably 30 to 45% by weight, more preferably 33 to 41% by weight. If the content of acrylonitrile is less than 20% by weight, the ductility of the polymer compound layer may be deteriorated and the durability of the carbon fiber composite material may deteriorate. When the content of the acrylonitrile is more than 60% by weight, adhesion between the polymer compound layer and the carbon fiber layer becomes difficult, Can happen.

The epoxy resin is added to improve the physical properties of the synthetic rubber. DIMER ACID denatured type, NBR denatured type, CTBN denatured type or urethane denatured type may be used, but preferably an acrylonitrile-butadiene rubber denatured epoxy resin Can be used. For the convenience of use and prevention of side reaction, a single-component type epoxy resin can be used. The amount of the epoxy resin is preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, and most preferably 5 to 10 parts by weight based on 100 parts by weight of the synthetic rubber. When the epoxy resin is used in an amount less than 1 part by weight, the effect of improving the physical properties of the synthetic rubber by the epoxy resin can not be expected. When the epoxy resin is used in an amount exceeding 20 parts by weight, the elongation of the synthetic rubber is increased, The bonding strength of the carbon fiber composite material is lowered.

The filler may be at least one material selected from the group consisting of carbon black, calcium carbonate, silica and diatomaceous earth, which is used to improve the strength of the synthetic rubber and improve the workability by lowering the flowability before curing. And preferably carbon black can be used. In the case of the synthetic rubber, when the flowability before curing is high, it is difficult to laminate with the carbon fiber layer, and it is difficult to laminate at a certain height. Therefore, it is preferable to control the flowability by adding the filler as described above. Further, in the case of the above filler, particularly carbon black, it is possible to increase the strength, durability and abrasion resistance of the rubber when it is mixed with rubber, so that it is preferably 1 to 20 parts by weight, more preferably 1 to 10 parts by weight, May be used in a mixture of 4 to 6 parts by weight. When the filler is mixed in an amount less than 1 part by weight, it is difficult to improve the flowability and durability of the filler. When the filler is used in an amount exceeding 20 parts by weight, the elasticity and elongation of the rubber are lowered and the durability and ductility It can fall.

The plasticizer is preferably a phthalate plasticizer, an epoxy plasticizer, a polyester plasticizer or an organic acid plasticizer as a material imparting flexibility of the rubber, more preferably dioctyl phthalate (DOP) or stearic acid ) Can be used. The plasticizer may be used in an amount of 1 to 20 parts by weight, preferably 3 to 10 parts by weight, more preferably 5 to 7 parts by weight, based on 100 parts by weight of the synthetic rubber. When the plasticizer is used in an amount of less than 1 part by weight, the plasticity of the plastic can not be improved. If the plasticizer is used in an amount exceeding 20 parts by weight, the plasticizer component may be eluted from the final product, have.

The weather resistance improver is an additive that improves the weatherability of the synthetic rubber by chemical or physical changes, so that the properties of the synthetic rubber are not changed when the synthetic rubber is exposed to the atmosphere to receive physical or chemical stimulation. It is preferable to use the above-mentioned weatherability improver to prevent physical changes due to chemical changes such as physical changes such as temperature and atmospheric pressure changes, irradiation with direct sunlight, acid rain, detergent, contact with human body secretions and the like. It is preferable to use tetramethyl quinoline (TMQ, RD) as a chemical weatherability improver and paraffine wax (SUN652) as a physical weather resistance improver. The weather resistance improver may be used in an amount of 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, more preferably 2 to 4 parts by weight based on 100 parts by weight of the synthetic rubber. When the weatherability improver is used in an amount less than 0.5 parts by weight, the weatherability of the carbon fiber composite material may be deteriorated due to a low improvement in weatherability. When the weather resistance improver is used in an amount exceeding 10 parts by weight, the weatherability of the carbon fiber composite material may be increased.

The additive may be used in an amount of 1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the synthetic rubber, to improve the processability and physical properties of the synthetic rubber. If it is used in an amount of less than 1 part by weight, it is difficult to expect improvement in physical properties. If it is used in an amount exceeding 20 parts by weight, the physical properties of the synthetic rubber may be improved. The additive is preferably used by mixing a plurality of components, and a crosslinking agent, a crosslinking accelerator, an antioxidant, a reaction promoter, a reaction retarder and the like may be mixed and used.

The carbon fiber composite material is more elastic than the conventional carbon fiber composite material and has excellent durability. Therefore, the carbon fiber composite material can be used for automobile interior and exterior materials, architectural structures, architectural interior materials, marine structural materials, and cellular communication device cases.

Hereinafter, the present invention will be described in detail through a method for producing a carbon fiber composite material.

(I) 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive Preparing a polymeric compound prepreg; (ii) preparing a carbon fiber prepreg by mixing carbon fibers and a thermosetting polymer; And (iii) alternately laminating the carbon fiber prepreg of the step (ii) and the polymer prepreg of the step (i), and then heating and molding the carbon fiber composite material to produce a carbon fiber composite material. ≪ / RTI >

The step (i) is a step of preparing a polymer compound prepreg, wherein 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 10 to 20 parts by weight of an additive are mixed and then molded into a plate having a predetermined thickness. Since the thermosetting resin is not cured, the polymer compound prepreg can be formed into various shapes before being molded by applying heat and pressure, because it has elasticity. The types and preferable mixing ratios of the polymer compounds are as described above.

The step (ii) is a step of preparing a carbon fiber layer prepreg (FIG. 3). In the basic method of producing a carbon fiber composite material, carbon fiber and a thermosetting polymer are mixed and molded to produce a carbon fiber sheet, And a polymer compound was laminated on the upper side to prepare a carbon fiber composite material. However, in the present invention, the carbon fiber and the thermosetting resin are mixed to prepare a plate-shaped carbon fiber prepreg, and then the carbon fiber layer and the polymer compound are laminated without performing the curing process. And molding.

The carbon fiber can be used regardless of its length and thickness as long as it is commercially available, and carbon fibers having appropriate length and thickness can be selected depending on the application and use environment. The carbon fibers may be carbon nanotubes, or single wall carbon nanotubes, double wall carbon nanotubes, multiwall carbon nanotubes, and mixtures thereof.

The thermosetting resin is impregnated with the carbon fiber to fix the carbon fiber. If the thermosetting resin is commercially available, it can be selected according to the application and the use environment. However, it is preferable that the thermosetting resin has a curing temperature and pressure similar to those of the polymer compound, so that the carbon fiber layer and the polymer compound are cured simultaneously. The thermosetting resin may include at least one selected from the group consisting of a urea resin, a melamine resin, an epoxy resin, an unsaturated polyester resin, an alkyd resin, a urethane resin, and a phenol resin. The thermosetting resin may include various additives such as a curing agent, And the like.

The step (iii) is a step of alternately laminating the carbon fiber prepreg and the polymer prepreg, followed by destruction and curing to produce a carbon fiber composite material. Unlike the conventional carbon fiber composite material, the carbon fiber prepreg The polymer compound prepreg is cured at one time. Therefore, the above-mentioned polymer compound and the thermosetting resin should have similar curing temperature and pressure as described above.

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

Example 1

(NBR) modified epoxy resin, 50 g of carbon black (N744), 50 g of a plasticizer (DOP), 10 g of a weather resistance improver (RD), 1 g of an acrylonitrile-butadiene rubber (KNB35L, KKPC) having an acrylonitrile content of 35% , SUN652), 10 g of a crosslinking agent and 35 g of a crosslinking accelerator (TT, CZ) were added to prepare a polymer compound.

Example 2

Except that an acrylonitrile-butadiene rubber (KNB40M, KKPC) having an acrylonitrile content of 40% by weight was used in place of the acrylonitrile-butadiene rubber having a content of acrylonitrile of 35% by weight in Example 1 A polymer compound was prepared in the same manner.

Example 3

A polymer compound was prepared in the same manner except that 100 g of the epoxy resin was used in Example 1.

Example 4

A polymer compound was prepared in the same manner except that 100 g of the epoxy resin was used in Example 2.

Comparative Example 1

A polymer compound was prepared in the same manner except that the epoxy resin was not used in Example 1.

Comparative Example 2

Except that acrylonitrile-butadiene rubber (KNB25M, KKPC) having a content of acrylonitrile of 25% by weight was used instead of acrylonitrile-butadiene rubber having a content of acrylonitrile of 35% by weight in Example 1 A polymer compound was prepared in the same manner.

Comparative Example 3

The rubber compound used for bonding the existing carbon fiber composite material was used.

Experimental Example 1

The polymer compounds of Examples 1 to 4 and Comparative Examples 1 to 3 were charged into a mold having a size of 20 cm × 20 cm at a thickness of 1.5 mm and cured to examine the physical properties of each sample. The physical properties of each sample are shown in Table 1 below.

importance Hardness
(JIS A) The tensile strength
(kgf / mm2) Elongation (%) 100% elongation tensile strength
(kgf / mm2) 300% elongation tensile strength
(kgf / mm2) Phosphorus strength
(kN / m) Example 1 1.1 54.0 43.0 376 13 30 30 Example 2 1.1 54.0 62.0 395 14 37 39.2 Example 3 1.1 53.0 54.0 448 12 29 31.3 Example 4 1.1 54.0 82.0 480 14 36 34.0 Comparative Example 1 1.0 51.6 32.1 274 11 21 25.3 Comparative Example 2 1.0 50.7 39.7 318 9 18 26.7 Comparative Example 3 1.2 46.8 28.7 137 3 - 12.8

As shown in Table 1, Examples 1 to 4 according to the present invention have higher durability than the rubber compound of Comparative Example 3 that has been used. The epoxy resin of Comparative Example 1 which did not use and Comparative Example 2 which contained 25% by weight of acrylonitrile showed higher durability than Comparative Example 3 which is a conventional rubber compound. However, in Examples 1 to 4 And it was found that it has low physical properties.

Example 5

A carbon fiber composite material was prepared using the polymer compound of Example 1 above.

A prepreg sheet impregnated with a thermosetting resin (epoxy 45 wt%) was inserted into a carbon fiber (continuous carbon fiber, 3K, PW (Plain Woven)) at a height of 0.5 mm into a 20 cm x 20 cm mold, The polymer compound was charged at a height of 0.5 mm. The properties of the carbon fiber prepreg used at this time are shown in Table 2 below.

Grade Thickness (mm) Total Wt
(g / m ² ) Fiber ArealWt
(g / m ² ) Resin
Content (%) WSN3K 0.227 336 198 41 Tensile Strength Tensile Modulus Fiber Density Resin Density 450 kgf / mm ² 24 x 10 ³ kgf / mm ² 1.77 g / cm < ² > 1.2 g / cm ²

Thereafter, a carbon fiber prepreg sheet was laminated at a height of 0.5 mm to form a sandwich structure with a total thickness of 1.5 T. The upper part of the mold was cured in an oven at 150 캜 while applying a pressure of 100 kg / cm 2.

Example 6

A carbon fiber book material was prepared in the same manner as in Example 5, except that the polymer compound of Example 2 was used.

Example 7

A carbon fiber book material was prepared in the same manner as in Example 5, except that the polymer compound of Example 3 was used.

Example 8

A carbon fiber composite material was prepared in the same manner as in Example 5, except that the polymer compound of Example 4 was used.

Comparative Example 4

The same material as in Example 5 was used, except that a carbon fiber prepreg sheet was charged into a mold of 20 cm x 20 cm at a height of 0.5 mm, and the upper portion was cured in an oven at 150 ° C while applying a pressure of 100 kg / The carbon fiber layer was first fabricated. 0.5 mm of the same polymer compound as in Example 5 was injected between the carbon fiber layers and then secondary cured under the same conditions.

Comparative Example 5

A carbon fiber composite material was prepared in the same manner as in Example 5, except that the polymer compound of Comparative Example 1 was used.

Experimental Example 2

The carbon fiber composite materials of Examples 5 to 8 and Comparative Examples 4 to 5 were used to perform an adhesive strength test. The results are shown in Table 3 below. The adhesive strength test was carried out by the method of ASTM D3163, and the specimen used at this time is shown in FIG.

Flexural Strength (Mpa) Adhesive strength (N / mm 2) Adhesive strength increase rate
(%, Based on Comparative Example 5) Example 5 179.4 4.59 14.36 Example 6 180.2 4.70 17.21 Example 7 192.5 4.98 24.19 Example 8 173.8 4.42 10.22 Comparative Example 4 110.3 1.87 -53.37 Comparative Example 5 160.3 4.01 -

As shown in Table 3, in Examples 5 to 8 of the present invention, there was an increase in high adhesive strength as compared with Comparative Example 5 in which no epoxy resin was used. In addition, the carbon fiber composite material produced by the method of Comparative Example 4 has a very low adhesive strength as compared with Examples 5 to 8 manufactured by the method of the present invention, so that when the carbon fiber composite material is manufactured by the method of the present invention, It is shown that it is greatly improved.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (5)

(a) a polymer compound layer comprising 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive, ; And
(b) a carbon fiber layer positioned on upper and lower portions of the polymer compound;
The carbon fiber composite material according to claim 1,
Wherein the synthetic rubber is acrylonitrile butadiene rubber (NBR), and the content of acrylonitrile is 35 to 40 wt%. delete The method according to claim 1,
The epoxy resin is a one-pack type epoxy resin, and is an acrylonitrile-butadiene rubber-modified epoxy resin. The method according to claim 1,
Wherein the filler comprises at least one selected from the group consisting of carbon black, calcium carbonate, silica, and diatomaceous earth. (i) a polymer compound comprising 1 to 20 parts by weight of an epoxy resin, 1 to 20 parts by weight of a filler, 1 to 20 parts by weight of a plasticizer, 0.5 to 10 parts by weight of an anti-weathering agent, and 1 to 20 parts by weight of an additive, Preparing a prepreg;
(ii) preparing a carbon fiber prepreg by mixing carbon fibers and a thermosetting polymer; And
(iii) alternately laminating the carbon fiber prepreg of the step (ii) and the polymer prepreg of the step (i), and then heating and forming the carbon fiber composite material;
Wherein the carbon fiber composite material is a carbon fiber composite material.

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