KR20180071790A - Epoxy composites containing pitch coated glass fiber - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to an epoxy composite material having improved heat dissipation property, and more particularly, to an epoxy composite material including glass fiber coated with a pitch and a manufacturing technique thereof.
According to the present invention, it is possible to provide an epoxy composite material having improved thermal stability and mechanical properties by adding a reinforcing agent in which the pitch-coated potting oil is carbonized.

Description

[0001] EPOXY COMPOSITES CONTAINING PITCH COATED GLASS FIBER [0002]

TECHNICAL FIELD The present invention relates to an epoxy composite material having improved heat dissipation property, and more particularly, to a technique for producing an epoxy composite material containing glass fiber coated with a pitch.

 Recently, the rapid development of the electronics industry has been regarded as an important issue that effectively emits heat due to an increase in power consumption due to the speed improvement and functionalization of electronic products. It is essential to develop highly heat-dissipative materials that can reduce the performance of equipment and shorten its service life. The initial heat-dissipating material is mainly made of a thermoplastic polymer having a low thermal conductivity. However, due to low thermal conductivity of the thermoplastic polymer of 0.2 W / mK or less and thermal stability problems such as thermal expansion coefficient due to its inherent characteristics, a metal or ceramic filler Is being studied. Among the ceramic fillers, silicon carbide materials have excellent thermal and mechanical properties such as noble strength, oxidation resistance, corrosion resistance, thermal shock resistance, abrasion resistance, and high thermal conductivity in a matrix. However, since silicon carbide requires a high content, there is a disadvantage that it finally weakens the mechanical properties. Therefore, reinforced epoxy composites are one of the good resins that can lead to thermal properties. Epoxy resins are excellent in adhesiveness, chemical resistance, corrosion resistance and heat resistance, and are excellent in processability, abrasion resistance and dimensional stability, and have the advantage of being able to cope with a wide variety of demands by selection of resin types and hardeners. For this reason, studies on reinforced epoxy composites combining these materials are very interesting.

An object of the present invention is to provide an epoxy composite material having improved thermal stability and mechanical properties by adding a reinforcing agent obtained by carbonizing pitch-coated glass fibers.

Another object of the present invention is to provide an epoxy composite material in which thermal stability and mechanical properties are further improved by simultaneously adding carbonized reinforcing agent coated with pitch and silicon carbide (SiC) as a reinforcing agent.

In order to achieve the above object, the present invention provides an epoxy resin composition comprising an epoxy resin and glass fibers coated with a pitch of 0.1 to 0.5 parts by weight based on 100 parts by weight of the epoxy resin.

The glass fiber coated with the pitch is carbonized after coating the glass fiber with a pitch.

The epoxy resin composition further comprises 0.4 to 2.8 parts by weight of silicon carbide (SiC).

Further, the present invention provides a method for producing an epoxy composite material having improved heat dissipation. The epoxy composite material manufacturing method includes the steps of coating a pitch on a glass fiber, carbonizing the glass fiber coated with pitch, mixing the carbonized pitch-coated glass fiber and epoxy resin, and curing the mixture .

The carbonizing step is performed in an inert gas atmosphere at a temperature of 600 to 1000 ° C.

Wherein the mixing step comprises mixing an epoxy resin and glass fibers coated with a pitch of 0.1 to 0.5 parts by weight relative to 100 parts by weight of the epoxy resin. Wherein the mixing step further comprises mixing 0.4 to 2.8 parts by weight of silicon carbide (SiC).

According to the present invention, it is possible to provide an epoxy composite material improved in thermal stability and mechanical properties by adding a reinforcing agent obtained by carbonizing pitch-coated glass fibers. Further, by providing the epoxy composite material with improved heat dissipation property according to the present invention, there is an effect that it can be used as a high heat dissipation material in the electronic industry.

1 is a scanning electron microscope (SEM) photograph of an epoxy composite according to an embodiment of the present invention.
FIG. 2 illustrates Fourier Transform Infrared Spectroscopy (FT-IR) results of an epoxy composite according to an embodiment of the present invention.
FIG. 3 is a thermogravimetric analysis (TGA) result of an epoxy composite according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

An epoxy resin composition according to one embodiment of the present invention includes an epoxy resin and glass fibers coated with a pitch of 0.1 to 0.5 parts by weight relative to 100 parts by weight of the epoxy resin.

The pitch-coated glass fibers are characterized by carbonization after coating with glass fibers at a pitch.

The epoxy resin composition further comprises 0.4 to 2.8 parts by weight of silicon carbide (SiC) based on 100 parts by weight of the epoxy resin. If the concentration of silicon carbide is less than 0.4 parts by weight based on 100 parts by weight of the epoxy resin, the heat dissipation effect is insufficient, which is not preferable. When the concentration of silicon carbide exceeds 2.8 parts by weight based on 100 parts by weight of the epoxy resin, Mutual agglomeration of silicon carbide occurs to form a heterogeneous phase, thereby reducing physical properties, which is not preferable. When the particle size of the silicon carbide used is 4 μm or less, the heat radiation effect is insignificant, and if it is 10 μm or more, the dispersing effect is insignificant.

According to another aspect of the present invention, there is provided a method of manufacturing an epoxy composite material having improved heat dissipation, comprising the steps of: coating a pitch with a glass fiber; carbonizing the pitch-coated glass fiber; Mixing and curing the mixture.

The pitch is characterized in that the organic solution and pitch are mixed in a mass ratio of 10: 1 to 1:10.

The organic solvent is preferably an aromatic solvent, but quinoline is more preferable. It is preferable to mix the organic solution and the pitch by stirring at room temperature for 1 to 5 hours.

It is preferable to dry in an oven at 80 to 100 ° C for 12 to 24 hours so that the used organic solution can be removed after coating the glass fiber with a pitch, and it is preferable that the glass fiber is washed 1 to 10 times with distilled water after drying.

And the step of carbonizing is performed in an inert gas atmosphere at a temperature of 600 to 1000 캜. More specifically, it is preferable to use a furnace in an inert atmosphere for heat treatment at a temperature raising rate of 1 to 4 占 폚 / min and a temperature of 600 to 1000 占 폚 for 5 to 60 minutes. In addition, the carbonization temperature is lower than 600 ° C., and the carbonization effect is insignificant. On the other hand, when the temperature is higher than 1000 ° C., the structure is broken and the physical properties of the glass fiber are deteriorated. After the heat treatment for carbonizing, it is preferable to further perform distilled water washing and drying to remove impurities remaining on the surface.

And mixing the epoxy resin and the glass fiber coated with the pitch of 0.1 to 0.5 parts by weight relative to 100 parts by weight of the epoxy resin. In addition, the mixing step may further include mixing 0.4 to 2.8 parts by weight of silicon carbide (SiC) with respect to 100 parts by weight of the epoxy resin.

The silicon carbide (SiC) preferably has a particle size of 4 to 10 mu m. When the particle size of the silicon carbide used is 4 μm or less, the heat radiation effect is insignificant, and if it is 10 μm or more, the dispersing effect is insignificant.

The curing step is characterized by curing at a temperature of 140 to 200 占 폚 and a pressure of 10 to 100 MPa for 3 hours or more. When the curing temperature is lower than 140 캜, it is not preferable because it can not induce complete curing. When it is higher than 200 캜, the physical properties are lowered, which is not preferable. When the pressure is less than 10 MPa, excess resin remains in the fiber to deteriorate the physical properties. When the pressure is more than 100 MPa, excessive amount of epoxy resin escapes to induce deterioration of adhesion between the resin and the filler.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Example  One.

Pitch - coated carbonized glass fiber was prepared.

Quinoline and pitch were mixed at a mass ratio of 10: 1 and stirred at room temperature for about 2 hours to prepare a pitch solution. The prepared pitch solution was coated with glass fiber uniformly on the glass fiber surface, dried in a drying oven at 70 ° C for 12 hours, and heat-treated at 600 ° C for 5 minutes using a tubular furnace in an inert atmosphere. To remove impurities remaining on the surface, the pitch-coated glass fibers were washed several times with distilled water and dried in a drying oven at 80 ° C for 12 hours.

Silicon carbide is prepared by pulverizing the particle size to 4 μm using a freezer mill.

The epoxy composite material containing pitch-coated glass fibers is prepared by adding 0.1 wt% of carbonized glass fiber pitch-coated to 0.4 wt% of epoxy resin and 0.4 wt% of silicon carbide. DDM (Dephenyl Deamino Metane), a curing agent, was added to the dispersed epoxy resin, and the bubbles formed in the mixing process were removed. Finally, an epoxy composite material containing glass fibers coated with pitch was prepared by curing by hot pressing at a pressure of 10 MPa and a high temperature at 140 캜 for 2 hours.

Example  2.

The carbonized glass fibers were carbonized for 10 minutes to form pitch-coated carbonized glass fibers, and 0.2 wt% of glass fibers and 0.8 wt% of silicon carbide were added during the course of preparing the composite material, and a pressure of 30 MPa The epoxy composite material including the glass fiber coated with the pitch by curing was produced.

Example  3.

The carbonized glass fiber was produced in the same manner as in Example 1 except that the carbonization temperature was 700 ° C. and the carbonization time was 20 minutes. In the course of producing the composite material, 0.4 wt% of glass fiber and 1.2 wt% of silicon carbide were added An epoxy composite material comprising glass fiber coated with pitch was prepared.

Example  4.

The same procedure as in Example 1 was carried out except that the particle size of silicon carbide was pulverized to 7 μm and cured at a pressure of 1.6 wt% and 50 MPa and a temperature of 170 ° C. An epoxy composite material containing glass fibers was prepared.

Example  5.

The carbonized glass fiber was produced in the same manner as in Example 1 except that the carbonized glass fibers were pitch-coated at a carbonization temperature of 800 ° C. and a carbonization time of 30 minutes, and 0.6 wt% of glass fibers and 2.0 wt% of silicon carbide were added An epoxy composite material comprising glass fiber coated with pitch was prepared.

Example  6.

The procedure of Example 1 was followed to cure at 70 MPa to prepare an epoxy composite material comprising glass fiber coated with a pitch.

Example  7.

The carbonized glass fiber was pitch-coated by carbonization for 40 minutes in the same manner as in Example 1, the particle size of silicon carbide was pulverized to 10 μm, and 0.8 wt% 2.4 wt% of silicon carbide was added and cured at a temperature of 200 캜 to prepare an epoxy composite material containing glass fiber coated with a pitch.

Example  8.

The procedure was carried out in the same manner as in Example 1, except that an epoxy composite material containing glass fibers coated with pitch was cured at a pressure of 90 MPa.

Example  9.

The carbonized glass fibers were pitch-coated at a carbonization temperature of 1000 ° C. and a carbonization time of 50 minutes to prepare carbonized glass fibers. In the course of producing the composite material, 1.0 wt% of glass fibers and 2.8 wt% Was added and cured at a pressure of 100 MPa to prepare an epoxy composite material containing pitch-coated glass fibers.

Comparative Example  One.

Glass fiber

Comparative Example  2.

pitch

Comparative Example  3.

Add DDM as a curing agent to the epoxy resin and mix to remove the bubbles generated during the mixing process. The epoxy composite was cured by hot pressing at 50 MPa and 170 DEG C for 2 hours.

Production conditions of the epoxy composite material according to the embodiment Carbonization temperature
(° C) Carbonization time
(min) Silicon carbide
Particle size
(μm) Glass fiber
usage
(wt%) Silicon carbide
usage
(wt%) Curing temperature
(° C) Curing pressure
(MPa) Example 1 600 5 4 0.1 0.4 140 10 Example 2 600 10 4 0.2 0.8 140 30 Example 3 700 20 4 0.4 1.2 140 30 Example 4 700 20 7 0.4 1.6 170 50 Example 5 800 30 7 0.6 2.0 170 50 Example 6 800 30 7 0.6 2.0 170 70 Example 7 900 40 10 0.8 2.4 200 70 Example 8 900 40 10 0.8 2.4 200 90 Example 9 1000 50 10 1.0 2.8 200 100 Comparative Example 1 - - - - - - - Comparative Example 2 - - - - - - - Comparative Example 3 - - - - - 170 50

Measurement example  1. Scanning electron microscope ( SEM ) Surface observation

Surface changes of carbonized pitch coated glass fibers were measured using a scanning electron microscope.

The results of surface observation using a scanning electron microscope are shown in Fig. According to the above results, it can be confirmed that the surface of the glass fiber is coated with the pitch. In comparison with this, it can be seen that the glass fiber (Comparative Example 1) is not coated with a pitch and the surface is not rough.

Measurement example  2. Fury  Transform Infrared Spectrum (FT-IR) Analysis

To analyze the functional groups on the carbonized pitch coated glass fiber surfaces, Fourier transform infrared spectral analysis was performed.

Fourier transform infrared spectral analysis results for surface functional group analysis are shown in FIG. According to the above results, it can be seen that Si-O-Si peak (1010 cm ^-1 ), carbonyl peak (1298 cm ^-1 ) and peaks of typical pitches are 2989 cm ^-1 , 2789 cm ^-1 and 1655 cm ^-1 , This indicates that the surface of the glass fiber is coated with a pitch.

Measurement example  3. Thermogravimetric analysis ( TGA , Thermogravimetric  analysis)

Thermogravimetric analysis was performed to determine the thermal stability of the epoxy composites according to the Examples. In the thermogravimetric analysis _, thermal stability was confirmed by using initial thermal decomposition temperature (IDT) and activation energy (E _{a , dec} ) values. The decomposition activation energies were also calculated using the Horowitz-Metzger integration method. The analytical conditions are nitrogen (N ₂₎ is a temperature rise rate under the atmosphere of 10 ℃ / min, measuring range is 30 to 900 ℃.

The thermogravimetric analysis results are shown in FIG. 3 and Table 2. According to the above results, it can be seen that the pyrolysis temperature and the activation energy increase as the content of silicon carbide increases in the epoxy composite material. This means that as the content of silicon carbide increases, the thermal stability increases.

The thermogravimetric analysis results of the epoxy composite material according to one embodiment of the present invention IPDT ( ^o C) E _{a , dec} (KJ / mol) Example 1 667 270 Example 2 667 289 Example 3 673 308 Example 4 724 335 Example 5 756 354 Example 6 761 360 Example 7 776 361 Example 8 782 365 Example 9 790 366 Comparative Example 1 - - Comparative Example 2 - - Comparative Example 3 596 258

Measurement example  4. Flexural strength  exam

The flexural strength of the epoxy composite material according to the example was measured. Flexural strength tests were conducted using a universal material tester in accordance with ASTM D 790 at a crosshead ratio of 1 mm / min and at least five specimens were tested per each example for reliability of the test results.

The flexural strength measurement results of the epoxy composites according to the examples are shown in Table 3. According to the results, as shown in Table 2, the flexural strength was increased as the content of silicon carbide was increased, and the flexural strength of Example 3 (silicon carbide added 2.0 g) was the highest.

The flexural strength of the epoxy composite according to an embodiment of the present invention Flexural Strength (MPa.m1 ^{/ 2} ) Example 1 9.57 Example 2 11.67 Example 3 12.54 Example 4 13.05 Example 5 13.98 Example 6 13.85 Example 7 11.87 Example 8 9.95 Example 9 7.63 Comparative Example 1 - Comparative Example 2 - Comparative Example 3 5.12

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

Epoxy resin and
Wherein the glass fiber is coated with a pitch of 0.1 to 0.5 parts by weight relative to 100 parts by weight of the epoxy resin.
The method according to claim 1,
Wherein the glass fiber coated with the pitch is carbonized after coating with a glass fiber at a pitch.
The method according to claim 1,
Wherein the epoxy resin composition further comprises silicon carbide (SiC) in an amount of 0.4 to 2.8 parts by weight based on 100 parts by weight of the epoxy resin.
Coating a pitch on the glass fiber;
Carbonizing the pitch coated glass fiber;
Mixing the carbonized pitch-coated glass fiber and the epoxy resin; And
Curing the mixture; Wherein the epoxy composite material has a high thermal conductivity.
5. The method of claim 4,
Wherein the carbonizing step is performed in an inert gas atmosphere at a temperature of 600 to 1000 ° C.
5. The method of claim 4,
Wherein the mixing step comprises mixing an epoxy resin and a glass fiber coated with a pitch of 0.1 to 0.5 part by weight relative to 100 parts by weight of the epoxy resin.
The method according to claim 6,
Wherein the mixing step further comprises mixing 0.4 to 2.8 parts by weight of silicon carbide (SiC) with respect to 100 parts by weight of the epoxy resin.

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