KR102008761B1 - Epoxy composites containing pitch coated glass fiber - Google Patents

Abstract

The present invention relates to an epoxy composite having improved heat dissipation, and more particularly, to an epoxy composite including a glass fiber coated with a pitch and a manufacturing technology thereof.
According to the present invention as described above, by adding a reinforcing agent carbonized Yurit oil coated with pitch, there is an effect of providing an epoxy composite with improved thermal stability and mechanical properties.

Description

EPOXY COMPOSITES CONTAINING PITCH COATED GLASS FIBER}

The present invention relates to an epoxy composite having improved heat dissipation, and more particularly, to a manufacturing technology of an epoxy composite including a glass fiber coated with a pitch.

 Recently, the rapid development of the electronics industry deals with the problem of effectively dissipating the generated heat as the power consumption increases due to the speed improvement and functionalization of electronic products. The heat generated in the electronic device degrades the performance of the device, and the development of high heat-dissipating material that can solve the problem is essential to shorten the life of the device. Early heat dissipating materials mainly used thermoplastic polymers with low thermal conductivity, but due to the low thermal conductivity of 0.2 W / mK and the inherent characteristics of thermoplastic polymers, thermal stability problems such as thermal expansion coefficient were caused, so that metal or ceramic fillers were improved to improve thermal diffusion characteristics. The method of addition is studied. Among the ceramic fillers, silicon carbide material has excellent thermal mechanical properties such as specific strength, oxidation resistance, corrosion resistance, thermal shock resistance, abrasion resistance, and high thermal conductivity in the matrix. However, silicon carbide requires a high content, which finally has a disadvantage of weakening mechanical properties. The reinforced epoxy composite is one of the good resins that can lead to thermal properties. Epoxy resins not only have good adhesiveness, chemical resistance, corrosion resistance, and heat resistance, but also have excellent workability, wear resistance, and dimensional stability, and have an advantage of being able to meet a wide range of needs by selecting and blending resins and curing agents. For this reason, research on reinforced epoxy composites combining them is 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 carbonized glass fiber coated with a pitch.

Another object of the present invention is to provide an epoxy composite having improved thermal stability and mechanical properties by simultaneously adding a pitch-coated carbonized reinforcing agent 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 a glass fiber 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 fiber is characterized in that the carbonized (carbonized) after coating the glass fiber with a pitch.

The epoxy resin composition is characterized in that it further comprises 0.4 to 2.8 parts by weight of silicon carbide (SiC).

In addition, the present invention provides a method for producing an epoxy composite with improved heat dissipation. The method for producing an epoxy composite material includes coating a pitch on glass fibers, carbonizing pitch coated glass fibers, mixing the carbonized pitch coated glass fibers and an epoxy resin, and curing the mixture. It includes.

The carbonizing step is characterized in that the temperature is performed at 600 to 1000 ℃, an inert gas atmosphere.

The mixing step is characterized in that the glass fiber coated with a pitch of 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the epoxy resin and the epoxy resin. The mixing step is characterized in that to further mix 0.4 to 2.8 parts by weight of silicon carbide (SiC).

According to the present invention as described above, by adding a reinforcing agent carbonized glass fiber coated with a pitch, there is an effect of providing an epoxy composite with improved thermal stability and mechanical properties. In addition, by providing an epoxy composite with improved heat dissipation according to the present invention, there is an effect that can be used as a high heat radiation material in the electronic industry.

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

Hereinafter, the present invention will be described in detail.

The epoxy resin composition of 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 fiber is characterized in that the carbonized (carbonized) after coating the glass fiber with a pitch.

In addition, the epoxy resin composition is characterized in that it further comprises 0.4 to 2.8 parts by weight of silicon carbide (SiC) relative to 100 parts by weight of epoxy resin. If the concentration of silicon carbide is less than 0.4 part by weight based on 100 parts by weight of epoxy resin, the heat dissipation effect is not preferable. If the concentration of silicon carbide exceeds 2.8 parts by weight based on 100 parts by weight of epoxy resin, dispersibility is lowered and It is not preferable because mutual agglomeration between silicon carbides occurs to form a non-uniform phase to reduce physical properties. The particle size of the silicon carbide used is not preferable because the heat dissipation effect is insignificant when 4 μm or less, and the dispersing effect is insignificant when it is 10 μm or more.

According to another aspect of the present invention, an epoxy composite material manufacturing method having improved heat dissipation may include coating a pitch on glass fibers, carbonizing pitch coated glass fibers, and carbonizing the pitch coated glass fibers and epoxy resin. Mixing and curing the mixture.

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

The organic solution is preferably selected from aromatic solvents, but more preferably quinoline. It is preferable to stir and mix the organic solution and the pitch for 1 to 5 hours at room temperature.

After coating the glass fibers with a pitch, the organic solution is preferably dried for 12 to 24 hours in an oven at 80 to 100 ° C., and preferably washed 1 to 10 times with distilled water after drying.

The carbonization step is characterized in that the temperature is carried out in 600 to 1000 ℃, an inert gas atmosphere. More specifically, it is preferable to heat-treat for 5 to 60 minutes at a temperature increase rate of 1 to 4 ° C / min and a temperature of 600 to 1000 ° C using a furnace of an inert atmosphere. In addition, the carbonization temperature is not preferable when the carbonization temperature is less than 600 ℃, if the carbonization temperature is less than 1000 ℃ to induce the physical properties of the glass fiber to break down the structural breakdown. In order to remove impurities remaining on the surface after heat treatment for carbonization, it is preferable to further perform distilled water washing and drying processes.

The mixing step is characterized in that the glass fiber coated with a pitch of 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the epoxy resin and the epoxy resin. In addition, the mixing step is characterized by further mixing 0.4 to 2.8 parts by weight of silicon carbide (SiC) relative to 100 parts by weight of epoxy resin.

Silicon carbide (SiC) preferably has a particle size of 4 to 10μm. The particle size of the silicon carbide used is not preferable because the heat dissipation effect is insignificant when 4 μm or less, and the dispersing effect is insignificant when it is 10 μm or more.

Curing step is characterized in that curing for 3 hours or more at a temperature of 140 to 200 ℃, pressure 10 to 100MPa conditions. When the curing temperature is 140 ° C. or lower, complete curing cannot be induced, and when the curing temperature is 200 ° C. or higher, the lowering of the physical properties is not preferable. If the pressure is 10 MPa or less, the resin remains excessively in the fiber to quantify the decrease in physical properties. If the pressure is 100 MPa or more, the epoxy resin is excessively released to induce a decrease in the binding between the resin and the filler, which is not preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Example  One.

Pitch coated carbide glass fibers were 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. After the glass fiber was loaded on the prepared pitch solution and uniformly coated on the surface of the glass fiber, it was dried for 12 hours in a drying oven at 70 ℃, and heat-treated at 600 ℃ using a tubular furnace of an inert atmosphere for 5 minutes. In order to remove impurities remaining on the surface, the pitch-coated glass fiber was washed several times with distilled water and then dried in a drying oven at 80 ℃.

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

Epoxy composite material including pitch coated glass fibers is melt mixed by adding 0.1 parts by weight of pitch coated carbide glass fibers and 0.4 parts by weight of silicon carbide to 100 parts by weight of epoxy resin. After the dispersion was completed by adding the curing agent DDM (Dephenyl Deamino Metane) to the epoxy resin was mixed, the bubbles generated during the mixing process were removed. Finally, an epoxy composite material including glass fibers coated with a pitch was cured by hot pressing at a pressure of 10 MPa and 140 ° C. for 2 hours using a hot press.

Example  2.

Prepared in the same manner as in Example 1, but carbonized for 10 minutes to produce a pitch-coated carbide glass fibers, 0.2 parts by weight of the glass fiber and 0.8 parts by weight of silicon carbide in the composite material manufacturing process and cured at a pressure of 30 MPa To prepare an epoxy composite material comprising a glass fiber coated with a pitch.

Example  3.

Manufactured in the same manner as in Example 1, the carbonization temperature is 700 ℃, the carbonization time is 20 minutes to produce pitch coated carbide glass fibers, 0.4 parts by weight of glass fiber and 1.2 parts by weight of silicon carbide in the composite material manufacturing process An epoxy composite material was prepared comprising pitch coated glass fibers.

Example  4.

Prepared in the same manner as in Example 1, the particle size of the silicon carbide was pulverized to 7 μm, and in the manufacturing process of the composite material was cured at 1.6 parts by weight of silicon carbide and a pressure of 50 MPa, a temperature of 170 ℃ coated with pitch Epoxy composite materials including glass fibers were prepared.

Example  5.

Prepared in the same manner as in Example 1, but the carbonization temperature is 800 ℃, the carbonization time of 30 minutes to produce a pitch-coated carbide glass fiber, in the manufacturing process of the composite material by adding 0.6 parts by weight of glass fiber and 2.0 parts by weight of silicon carbide An epoxy composite material was prepared comprising pitch coated glass fibers.

Example  6.

The process was carried out in the same manner as in Example 1, but was cured at a pressure of 70 MPa to prepare an epoxy composite material comprising a glass fiber coated with a pitch.

Example  7.

In the same manner as in Example 1, but carbonized for 40 minutes to produce a pitch-coated carbide glass fiber, grinding the particle size of silicon carbide to 10 μm, 0.8 parts by weight of glass fiber in the composite material manufacturing process and 2.4 parts by weight of silicon carbide was added, and cured at a temperature of 200 ° C. to prepare an epoxy composite material including glass fibers coated with pitch.

Example  8.

The process was carried out in the same manner as in Example 1, but was cured at a pressure of 90 MPa to prepare an epoxy composite material comprising a glass fiber coated with a pitch.

Example  9.

The process was carried out in the same manner as in Example 1, but the carbonization temperature is 1000 ℃, the carbonization time is 50 minutes to manufacture a pitch coated carbide glass fiber, 1.0 part by weight of glass fiber and 2.8 parts by weight of silicon carbide in the composite material manufacturing process Epoxy composites comprising glass fibers coated with pitch were added and cured at a pressure of 100 MPa.

Comparative example  One.

Fiberglass

Comparative example  2.

pitch

Comparative example  3.

DDM, a curing agent, is added to the epoxy resin and mixed to remove bubbles generated during the mixing process. Epoxy composite material was prepared by hot pressing at 50 MPa at 170 ° C. for 2 hours using a hot press.

Manufacturing Conditions of Epoxy Composites According to Examples Carbonization temperature
(℃) Carbonization time
(min) Silicon Carbide
Particle size
(μm) Fiberglass
usage
(wt%) Silicon Carbide
usage
(wt%) Curing temperature
(℃) 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 with

The surface change of the carbonized pitch coated glass fiber was measured using a scanning electron microscope.

Surface observation results using a scanning electron microscope is shown in FIG. According to the result, it can be seen that the pitch is coated on the glass fiber surface. In comparison, it can be seen that the glass fiber (Comparative Example 1) is not coated with a pitch and thus the surface is not rough.

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

In order to analyze the functional groups of the carbonized pitch-coated glass fiber surface, Fourier infra-red spectrum analysis was performed.

Fourier transform infrared spectral analysis for surface functional group analysis is shown in FIG. 2. According to the results, as shown in FIG. 2, it can be seen that the Si-O-Si peak (1010cm ^-1 ) and the carbonyl peak (1298cm ^-1 ) and the peaks of typical pitches 2989cm ^-1 , 2789cm ^-1, and 1655cm ^-1 , This indicates that the pitch is coated on the surface of the glass fiber.

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. The thermogravimetric analysis confirmed the thermal stability using the initial thermal decomposition temperature (IDT) and the activation energy (E _{a , dec} ) values. Decomposition activation energy was also calculated using the integration method of Horowitz-Metzger. Analytical conditions are the temperature increase rate of 10 ℃ / min under nitrogen (N ₂ ) atmosphere, the measurement range is 30 to 900 ℃.

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

Thermogravimetric Analysis Results of Epoxy Composites According to an 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

Flexural strength of the epoxy composite according to the embodiment was measured. The flexural strength test was tested using a universal testing machine according to ASTM D 790 at a crosshead ratio of 1 mm / min, and at least five specimens for each example were tested for reliability of the test results.

Flexural strength measurement results of the epoxy composite material according to the embodiment are shown in Table 3. According to the results, as shown in Table 2, the bending strength increased as the content of silicon carbide increased, and Example 3 (silicon carbide 2.0g addition group) had the highest bending strength.

Flexural strength of epoxy composite according to one embodiment of the present invention Flexural Strength (MPa.m ^1/2 ) 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

As mentioned above, specific portions of the present disclosure have been described in detail, and it is apparent to those skilled in the art that such specific techniques are merely preferred embodiments, and thus the scope of the present disclosure is not limited thereto. something to do. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

Epoxy resins;
Glass fibers coated with a pitch of 0.1 to 0.8 parts by weight with respect to 100 parts by weight of the epoxy resin; And
0.4 to 2.4 parts by weight of silicon carbide (SiC) relative to 100 parts by weight of the epoxy resin,
The pitch coated glass fiber is carbonized after coating the glass fiber with a pitch,
Epoxy resin composition, characterized in that the particle size of the silicon carbide (SiC) is 4 to 10 ㎛.
The method of claim 1,
The pitch coated glass fiber is 0.2 to 0.8 parts by weight relative to 100 parts by weight of the epoxy resin,
The silicon carbide is 0.8 to 2.4 parts by weight relative to 100 parts by weight of the epoxy resin,
Epoxy resin composition, characterized in that the initial thermal decomposition temperature (IDT) is 667 to 776 ℃.
delete Coating a pitch on the glass fibers;
Carbonizing the pitch coated glass fibers;
Mixing the carbonized pitch coated glass fiber with an epoxy resin and silicon carbide (SiC); And
Curing the mixture of carbonized pitch coated glass fiber and epoxy resin, silicon carbide (SiC),
The mixing step is mixing the epoxy resin and glass fiber coated with a pitch of 0.1 to 0.8 parts by weight with respect to 100 parts by weight of the epoxy resin, 0.4 to 2.4 parts by weight of silicon carbide (SiC),
The particle size of the silicon carbide (SiC) is 4 to 10 ㎛ characterized in that the heat dissipation improved epoxy composite material manufacturing method.
The method of claim 4, wherein
The pitch coated glass fiber is 0.2 to 0.8 parts by weight relative to 100 parts by weight of the epoxy resin,
Said silicon carbide is 0.8 to 2.4 parts by weight relative to 100 parts by weight of the epoxy resin manufacturing method of the epoxy composite material with improved heat dissipation.
The method of claim 5,
The curing step is a method of producing an epoxy composite with improved heat dissipation, characterized in that carried out under a curing pressure of 30 to 70 Ma. delete

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