KR20190023273A - Polymer-boron nitride based filler composites and preparation methods thereof - Google Patents

Abstract

The present invention relates to a polyamide/boron nitride composite which comprises a polyamide; and boron nitride filler dispersed on the surface of the polyamide and physically and chemically bonded to the polyamide, wherein the polyamide and boron nitride filler are treated with mechanofusion and plasma simultaneously in a mixed state. According to a production method of the present invention, dispersibility and bonding force between the polyamide and the boron nitride filler are excellent.

Description

[0001] The present invention relates to polymer-boron nitride filler composites and their preparation,

The present invention relates to a polymer-boron nitride composite having excellent mechanical properties and thermal conductivity and a method for producing the same. More particularly, the present invention relates to polyamide and boron nitride filler dispersed with excellent dispersion and physically- And a polyamide / boron nitride composite excellent in thermal conductivity and a method for producing the same.

The heat dissipation material means a material that can easily release the heat generated from the inside to the outside when the electronic / mechanical device is operated. Since heat generated from the inside not only deteriorates the performance of the device but also causes deformation and reduces the life of the device, it is necessary to develop an effective heat dissipation material to solve the problem. Conventional heat dissipation materials are mainly made of metal, but recently, a composite material having a high heat conductivity and a mixture of a filler and a polymer material has been attracting attention. Particularly, in the case of the polymer-boron nitride composite, the advantages such as processability, light weight and low cost obtained from the polymer material, and the insulating property and high thermal conductivity provided by the boron nitride, do not have the conventional metal material or the composite material containing the carbon filler Has attracted attention as a material having a high level of heat radiation performance while having an insulation characteristic. However, when a polymer-boron nitride composite is produced through a conventional processing process, the affinity between the polymer and the boron nitride filler is weak, so that the mechanical properties of the composite are poor and the boron nitride is not evenly distributed in the polymer matrix. And had thermal conductivity problems. Therefore, it is required to develop a new processing process that can improve the mechanical properties and thermal conductivity of the composite material in order to be practically applied to the heat-dissipating material of the polymer-boron nitride filler composite. The present invention aims at enhancing the affinity between the two materials and enhancing the dispersion of the filler in the polymer matrix through the combination of the physical-chemical bonding method and the plasma treatment during the complexing process of the polymer matrix and the filler, thereby improving the mechanical properties and thermal conductivity So as to manufacture the excellent polymer composite heat dissipation material.

International Patent No. 2007-138743 Korea Patent No. 10-0448115 Korean Patent Publication No. 10-2003-0027219

The first problem to be solved by the present invention is a polymer composite in which a polymer and a boron nitride filler are physically and chemically bonded to each other to improve mechanical properties and thermal conductivity. A boron nitride filler is added to polyamide And a polyamide / boron nitride composite in which mechanical properties and thermal conductivity are simultaneously improved by physical-chemical bonding.

A second object of the present invention is to provide a method for producing a polyamide / boron nitride composite having the above characteristics.

According to one aspect of the present invention,

Polyamide; And a boron nitride filler dispersed on the surface of the polyamide and physically and chemically bonded to the polyamide, wherein the polyamide and the boron nitride filler are mixed at the same time with mechanofusion mechanofusion and plasma treated polyamide / boron nitride composites are provided.

The polyamide may be any one or two or more blends selected from a ring-opening polymer of a lactam compound, a polycondensation polymer of ω-amino undecanoic acid, and a polycondensation polymer of a diamine and an organic acid.

The polyamide may be any one or two or more blends selected from polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610 and polyamide 612.

The boron nitride filler may be selected from the group consisting of hexagonal boron nitride, wurtzite boron nitride, cubic boron nitride, boron nitride nanosheet, And may be at least one selected from the group consisting of boron nitride nanotubes.

The plasma may be any one selected from a nitrogen plasma, an argon plasma, and an oxygen plasma.

The polyamide / boron nitride composites may contain 95.5 to 79.5% by weight of polyamide and 4.5 to 20.5% by weight of boron nitride filler.

At least one selected from nitrogen, argon and oxygen atoms may be inserted into at least one surface selected from the polyamide and the boron nitride filler.

Between the polyamide and the boron nitride filler, at least one chemical bond selected from an amide bond, an amine bond, an ether bond, a carbonyl bond, an ethylene bond, an acetal bond and a urea bond may be formed.

According to another aspect of the present invention,

(1) administering polyamide powder and boron nitride powder to a chamber of a dry high energy type mixer; And (2) a step of producing a plasma in the chamber while simultaneously performing mechanofusion to produce a composite in which the boron nitride filler is dispersed and physically-chemically bonded to the polyamide, wherein the polyamide / boronite A process for the preparation of the rye complex is provided.

The mechanofusion can be performed by rotating the chamber at a rate of 100 to 5000 rpm for 5 to 30 minutes under the condition that the pressure inside the chamber is 1.010 ² Pa to 1.010 ³ Pa.

The plasma generation and mechanofusion may be performed in air, nitrogen, argon or oxygen atmosphere.

The plasma may generate a functional group containing nitrogen or oxygen atoms on at least one surface selected from polyamide and boron nitride fillers.

The functional group may be an amide group, an amine group, a hydroxy group, an aldehyde group, a carboxyl group, a carbonyl group and a urea group And the like.

A method for producing a composite by simultaneously treating a polyamide and a boron nitride filler according to the present invention with a mechanofusion and a plasma may be a polyamide-boron nitride filler manufactured by a conventional Henschel type mixer, a roll mill, The dispersibility and bonding strength between the polyamide and the boron nitride filler is superior to that of the mixture. Particularly, although the conventional polyamide-boron nitride filler mixture has a problem that the mechanical properties exhibited by the polyamide are lowered, the composite according to the present invention has an increased interfacial interaction between the polyamide and the boron nitride filler, The contact surface area between the amide and the boron nitride filler was increased to increase the mechanical properties of the polyamide than that of the original polyamide. In particular, the thermal conductivity was greatly improved. In addition, the chemical bond formed between the polyamide and the boron nitride filler greatly increases the affinity and bonding force between the polyamide and the boron nitride filler, thereby enhancing the mechanical properties of the polyamide and enhancing the phonon delivery So that the thermal conductivity can be increased. The polyamide / boron nitride filler composite according to the present invention exhibits remarkably improved thermal conductivity while increasing the tensile strength of the originally polyamide even when the boron nitride filler is added in a high content, so that the conventional mechanical properties and thermal conductivity are reduced Compared to composites, it can be used in various fields including heat dissipation materials.

Fig. 1 is a schematic view of the process of Production Example 1. Fig.
2 shows the measurement results of tensile strength (a), tensile strain (b) and Young's modulus (c) according to Test Example 1.
3 shows the result of measuring the thermal conductivity according to Test Example 1. Fig.
4 is a result of differential scanning calorimetry (DSC) analysis according to Test Example 2. Fig.
Fig. 5 is a thermogravimetric analysis (TGA) analysis result according to Test Example 3. Fig.
6 is a dynamic thermal characteristic analyzer (DMA) analysis result according to Test Example 4. Fig.
7 is a result of infrared spectroscopy (FT-IR) analysis according to Test Example 5. Fig.
8 is a result of infrared camera analysis according to Test Example 5. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the polyamide / boron nitride composite of the present invention will be described.

The polyamide / boron nitride composites of the present invention include polyamides; And a boron nitride filler dispersed on the surface of the polyamide by means of mechanofusion and plasma treatment and physico-chemically bonded to the polyamide.

The polyamide / boron nitride composites of the present invention are characterized in that polyamides and boron nitride fillers having poor affinity to each other are combined with a good dispersity and strong interaction through simultaneous treatment of mechanofusion and plasma.

The composite according to the present invention is excellent in the dispersibility of polyamide and boron nitride filler, so that the content of filler is increased compared to a polyamide-boron nitride filler mixture prepared by a conventional dry mixer such as a Henschel type mixer, a roll mill or a pin mill Can be applied to new engineering plastics materials with new properties such as thermal conductivity while retaining the inherent properties of polyamides.

As described above, according to the prior art, the simple mixed polyamide-boron nitride filler mixture has poor dispersibility of the filler in the polyamide polymer matrix, resulting in phase separation due to the formation of aggregates of the fillers. Therefore, the phonons in the complex can not be effectively transferred, and the thermal conduction can not be improved. The limit of the improvement of the thermal conductivity can be improved to some extent by increasing the content of the boron nitride filler, but it is not easy to use industrially because it lowers the mechanical properties of the polyamide and causes the lowering of the processability.

In the present invention, the surfaces of polyamide and boron nitride fillers are modified by physical and chemical methods through simultaneous treatment of mechanofusion and plasma, and as a result, composites having excellent mechanical properties and thermal conductivity can be produced.

The polyamide / boron nitride composites according to the present invention have improved mechanical properties such as tensile strength compared to conventional polyamide or conventional polyamide-boron nitride filler mixtures, despite the addition of boron nitride fillers, The degree of improvement was remarkably improved.

According to the present invention, a functional group may be formed by nitrogen, argon or oxygen atoms on at least one surface selected from the polyamide and the boron nitride filler, and the functional group may be formed by a plasma treatment . According to the present invention, the plasma may be a nitrogen plasma, an argon plasma or an oxygen plasma, an air plasma, preferably a nitrogen plasma or an oxygen plasma, and most preferably a nitrogen plasma.

According to the present invention, the treatment of the plasma is carried out by treating the surface of the polyamide and / or boron nitride filler with the nitrogen, argon or oxygen atom in an amount of 1 to 100 ppm selected from an amide group, an amine group, a hydroxyl group, an aldehyde group, a carboxyl group, a carbonyl group and a urea group More than one species. In addition, the functional groups formed on the surface of the polyamide and the polyamide / boron nitride composite filler may form strong chemical bonds between the polyamide and the boron nitride filler to increase the affinity between the polyamide and the boron nitride filler, And the boron nitride filler can be stably bonded.

According to the present invention, the chemical bond formed between the polyamide and the boron nitride filler may be at least one selected from an amide bond, an amine bond, an ether bond, a carbonyl bond, an ester bond, an ethylene bond, an acetal bond and a urea bond, But is not limited to.

The polyamide according to the present invention is not particularly limited as far as it is produced by a previously known method and is preferably a polymer formed by ring-opening polymerization of a lactam compound, polycondensation of ω-aminoundecanoic acid or polycondensation of a diamine and an organic acid And blends of two or more of these polymers are also included in the polyamide of the present invention.

In the present invention, the lactam may be epsilon -caprolactam, and the diamine may be any one or two or more selected from hexamethylenediamine, tetramethylenediamine, and metaxylenediamine, and the organic acid is adipic acid, sebacic acid, Dodecanoic acid, and dodecanoic acid.

According to the present invention, the preferred polyamide may be a blend of polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612 and two or more thereof.

Wherein said polyamide 6 is prepared by ring-opening polymerization of epsilon -caprolactam, said polyamide 11, 12 being prepared by polycondensation of omega-amino undecanoic acid, said polyamide 46 being a mixture of tetramethylenediamine and adipic acid, And polyamides 66, 610 and 612 are prepared by polycondensation of hexamethylenediamine with adipic acid, sebacic acid and dodecanoic acid, respectively.

The boron nitride filler according to the present invention may be selected from the group consisting of hexagonal boron nitride (h-BN), wurtzite boron nitride (w-BN), cubic boron nitride (c-BN), boron nitride nanosheets (BNNSs), and boron nitride nanotubes (BNNTs).

According to the present invention, the polyamide / boron nitride composite contains 95.5 to 79.5% by weight of polyamide and 4.5 to 20.5% by weight of boron nitride filler to produce a composite having high tensile strength and excellent strain and thermal conductivity .

Since the polyamide / boron nitride complex according to the present invention is physically and chemically bonded to the polyamide with the boron nitride filler, there is no problem of forming aggregates between the boron nitride fillers, so that phonons in the composite can be effectively transferred, The thermal conductivity can be improved.

Hereinafter, a method for producing the polyamide / boron nitride composite of the present invention will be described.

The method for producing a polyamide / boron nitride composite of the present invention comprises the steps of: 1) injecting a polyamide powder and a boron nitride filler powder into a chamber of a dry high energy type mixer; And 2) producing a plasma in the chamber while simultaneously performing mechanofusion to produce a composite in which the boron nitride filler is dispersed and physico-chemically bonded to the polyamide.

The mechanofusion refers to the application of high mechanical energy to a mixture of polyamide and boron nitride filler, which causes the polyamide particles and the boron nitride filler particles to undergo a strong shear force and compressive force, whereby the polyamide particles and the boron nitride filler particles And the boron nitride filler particles physically-chemically bond to the surface of the polyamide particles.

The mechanofusion is preferably performed by rotating the chamber at a rate of 100 to 5000 rpm for 5 to 30 minutes under the condition that the pressure inside the chamber is 1.0 × 10 ² Pa to 1.0 × 10 ³ Pa.

The boron nitride filler has a disadvantage in that it is not compatible with a polymer such as polyamide and a lot of aggregates are generated in the preparation of a crude liquid or a compounding, and the thermal conductivity property is deteriorated thereby making it difficult to be applied commercially. In addition, according to the prior art, when mixed with general dry mixer such as Henschel type mixer, difference in specific gravity is generated, so that it is not coated on polyamide or only very small amount is coated, and most of boron nitride fillers are independently flocculated .

The present invention physically-chemically bonds a boron nitride filler to a polyamide by mechanofusion so that the boron nitride filler can be dispersed in a good dispersion in the polyamide matrix. Particularly, it has been confirmed that when a plasma is generated together with the mechanofusion, the polyamide and the boron nitride filler can be bonded with an improved interaction. The increase in the boron nitride filler dispersion and the improvement in bonding strength with polyamide can greatly increase the thermal conductivity of the composite.

The plasma generation and the mechanofusion may be performed in an atmosphere of air, nitrogen, argon, or oxygen, and the plasma may be performed in order to form a functional group on at least one of a polyamide and a boron nitride filler Lt; / RTI >

According to the present invention, the functional group may be at least one member selected from an amide group, an amine group, a hydroxyl group, an aldehyde group, a carboxyl group, a carbonyl group and a urea group. The functional groups formed on the surface of the polyamide or / and boron nitride filler increase the affinity between the polyamide and the boron nitride filler and increase the affinity between the polyamide and the boron nitride filler for amide bond, amine bond, ether bond, carbonyl bond , Ester bond, ethylene bond, acetal bond and urea bond To form one or more bonds to be selected and to be stably bonded.

According to the present invention, preferred polyamide / boron nitride composites contain 0.1 to 40 parts by weight of the boron nitride filler based on 100 parts by weight of the polyamide; The inside of the chamber is constituted by a nitrogen atmosphere of 1.0 × 10 ² Pa to 1.0 × 10 ³ Pa and a voltage of 1 to 2 kV is applied thereto; The chamber may be rotated at a speed of 1000 to 5000 rpm for 5 to 30 minutes.

According to the present invention, it is preferred that the polyamide / boron nitride composites contain 95.5 to 79.5% by weight of polyamide and 4.5 to 20.5% by weight of boron nitride filler.

The inside of the chamber is constituted by a nitrogen atmosphere of 5.0 × 10 ² Pa and a voltage of 1 to 2 mV is applied thereto; And the chamber may be rotated at a speed of 2000 rpm for 10 minutes. The composite produced by performing the above conditions has a higher tensile strength as well as a higher tensile strain and a higher thermal conductivity than the composite under other conditions.

The polyamide / boron nitride composites of the present invention can be used by injection, extrusion and injection. The extruded or extruded and extruded polyamide / boron nitride composites have excellent dispersibility of the polyamide and boron nitride fillers in the matrix, and have not only uniform mechanical strength but also excellent thermal conductivity.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be clear to those who have knowledge.

[Example]

Manufacturing example  One

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing a process for producing a polyamide 66 / boron nitride filler composite of Production Example 1. FIG. Production example 1 will be described with reference to Fig.

297 g of polyamide 66 and 3 g of hexagonal boron nitride filler were placed in a chamber of a dry high energy type mixer. The inside of the chamber was replaced with a nitrogen atmosphere to adjust the pressure to 5.0 × 10 ² Pa. During the mechanofusion process, a voltage of 1 to 2 kV was applied to the inside of the chamber to generate a plasma in the chamber for 10 minutes to produce a polyamide 66 / Boron nitride filler composite was prepared.

Manufacturing example  2

285 g of polyamide 66 and 15 g of boron nitride filler were placed in a chamber of a dry high energy type mixer. Thereafter, the preparation was carried out in the same manner as in Preparation Example 1.

Manufacturing example  3

270 g of polyamide 66 and 30 g of boron nitride filler were placed in a chamber of a dry high energy type mixer. Thereafter, the preparation was carried out in the same manner as in Preparation Example 1.

Manufacturing example  4

270 g of polyamide 66 and 60 g of boron nitride filler were placed in a chamber of a dry high energy type mixer. Thereafter, the preparation was carried out in the same manner as in Preparation Example 1.

compare Manufacturing example  One

297 g of polyamide 66 and 3 g of boron nitride filler were mixed on a 3 roll machine for 72 hours to prepare a polyamide 66 / boron nitride filler mixture.

compare Manufacturing example  2

285 g of polyamide 66 and 15 g of boron nitride filler were mixed on a 3 roll machine for 72 hours to prepare a polyamide 66 / boron nitride filler mixture.

compare Manufacturing example  3

270 g of polyamide 66 and 30 g of boron nitride filler were mixed for 72 hours using a 3 roll machine to prepare a polyamide 66 / boron nitride filler mixture.

compare Manufacturing example  4

270 g of polyamide 66 and 60 g of boron nitride filler were mixed for 72 hours using a 3 roll machine to prepare a polyamide 66 / boron nitride filler mixture.

Example  One

The polyamide 66 / boron nitride filler composite of Preparation Example 1 was extruded in an extruder in order to disperse the boron nitride filler adhered to the polyamide 66 more evenly. The extrusion conditions were 1, 2, 3, 4, 5, 6, and 7 die temperatures of 260, 265, 265, 265, 265, 263, 260 ℃ and screw speed of 100 rpm. The extruded sample was cut with a pelletizer using a pelletizer.

Next, a polyamide 66 / boron nitride filler composite prepared as a pellet was injected using an injection molding machine to prepare a specimen. The injection conditions were 1, 2, 3 and 4 die temperatures of 260, 265, 265, 265 ℃, screw speed of 150 rpm and back pressure of 8.5 bar.

Example  2

A specimen was prepared by the method of Example 1 except that the polyamide 66 / boron nitride filler composite of Production Example 2 was used instead of Production Example 1.

Example  3

A specimen was prepared in the same manner as in Example 1, except that the polyamide 66 / boron nitride filler composite of Production Example 3 was used instead of Production Example 1.

Example  4

A specimen was prepared in the same manner as in Example 1 except that the polyamide 66 / boron nitride filler composite of Production Example 4 was used instead of Production Example 1.

Comparative Example  One

The polyamide 66 / boron nitride filler mixture of Comparative Preparation Example 1 was used instead of the polyamide 66 / boron nitride filler composite of Production Example 1, by extrusion and injection in the same manner as in Example 1.

Comparative Example  2

The polyamide 66 / boron nitride filler mixture of Comparative Preparation Example 2 was used instead of the polyamide 66 / boron nitride filler composite of Production Example 5, by extrusion and injection in the same manner as in Example 1. [

Comparative Example  3

The polyamide 66 / boron nitride filler mixture of Comparative Preparation Example 3 was used instead of the polyamide 66 / boron nitride filler composite of Production Example 1, by extrusion and injection in the same manner as in Example 1.

Comparative Example  4

The polyamide 66 / boron nitride filler mixture of Comparative Preparation Example 4 was used instead of the polyamide 66 / boron nitride filler composite of Production Example 1, by extrusion and injection in the same manner as in Example 1.

[Test Example]

Test Example  1: Measurement of mechanical properties and thermal conductivity

The tensile strength, tensile strain and Young's modulus of the specimens according to Examples 1, 2, 3 and 4 and Comparative Examples 1, 2, 3 and 4 were measured using a universal testing machine (UTM) Young's modulus) was measured. The thermal conductivity of the specimen was measured using a thermal conductivity meter. The results are shown in Table 1 and FIGS. 2 and 3, respectively.

division Tensile Strength (MPa) Young's modulus (MPa) Tensile strain (%) Thermal conductivity (W / mK) Example 1 86.2 ± 0.4 3029.1 ± 109.9 16.3 ± 0.3 0.88 + 0.02 Example 2 85.3 ± 0.5 3403.9 ± 115.3 9.6 ± 0.2 1.41 + 0.02 Example 3 84.2 ± 0.4 4193.3 ± 129.4 8.4 ± 0.3 2.04 ± 0.01 Example 4 82.3 ± 0.5 5065.3 ± 170.3 4.8 ± 0.3 2.72 ± 0.02 Comparative Example 1 75.1 ± 3.2 2624.4 ± 105.5 12.5 ± 1.3 0.33 ± 0.01 Comparative Example 2 71.9 ± 2.4 2843.1 ± 178.8 6.9 ± 0.9 0.41 + - 0.01 Comparative Example 3 68.7 ± 1.9 3077.9 ± 128.3 5.1 ± 0.9 0.49 + 0.02 Comparative Example 4 61.9 ± 2.9 3631.1 + - 248.6 3.3 ± 0.4 0.54 + 0.02

As shown in Table 1 and Figs. 2 and 3, the composite molded under the same conditions showed that the specimens of Examples 1, 2, 3 and 4 according to the present invention exhibited excellent tensile strength and thermal conductivity Respectively.

Test Example  2: differential scanning calorimeter ( DSC ) analysis

A differential scanning calorimetry analysis was performed to determine the melting temperature (T _m ) and melting enthalpy (delta H) of the polyamide 66 / boron nitride filler composite, which is shown in FIG. Fig. 4 shows the results of differential scanning calorimetry analysis of Comparative Example 2 and Example 2. Fig.

According to FIG. 4, the specimen according to Example 2 exhibited a melting temperature of about 20 ° C or higher and a melting enthalpy of about 20 J / g lower than that of Comparative Example 2, confirming the bonding between polyamide 66 and boron nitride filler I could. The melting temperature and melting enthalpy of the polyimide 66 used were 263.5 ° C and 79.3 J / g, respectively.

Test Example  3: thermogravimetric analyzer ( TGA ) analysis

Analysis was performed with a thermogravimetric analyzer to check the binding of the polyamide 66 / boron nitride filler complex and the content of filler in the composite. This is shown in FIG. Fig. 5 shows the results of the thermogravimetric analyzer of Comparative Example 2 and Example 2. Fig.

5, it can be seen that the thermal decomposition temperature of the specimen according to Example 2 is lower than that of Comparative Example 2. The lowering of the pyrolysis temperature is a result of bonding between polyamide 66 and boron nitride, resulting in the chain of polyamide 66 being cut off. As a result, it was confirmed that a bond was formed between the polymer and the filler.

Test Example  4: Dynamic Thermal Characterization DMA ) analysis

In order to confirm the glass transition temperature (T _g ) of the polyamide 66 / boron nitride filler composite, analysis was performed using a dynamic thermal characteristic analyzer, which is shown in FIG. 6 shows the results of the analysis of the dynamic thermal characteristic analyzer of Comparative Example 2 and Example 2. Fig.

According to FIG. 6, the glass transition temperature of the specimen according to Example 2 was higher than that of Comparative Example 2. This fact confirms that the bond between the polyamide 66 and the boron nitride filler was achieved. The glass transition temperature of the polyimide 66 used is 69 占 폚.

Test Example  5: Fury  Conversion Infrared Spectroscopy ( FT - IR ) analysis

In order to confirm whether the bonding of the polyamide 66 / boron nitride filler according to the present invention is formed by the combined treatment of mechanofusion and plasma, the specimens of Example 2 and Comparative Example 2 according to the present invention were subjected to Fourier transform infrared spectroscopy And this is shown in FIG.

It can be seen that the peak of the complex of Example 2 at 3300 cm ^-1 , 3070 cm ^-1 and 2930 ~ 2860 cm ^-1 is reduced as compared with that of Comparative Example 2 and the polyamide peak. Also, it can be seen that the peak at 1417 cm ^-1 is smaller than that of Comparative Example 2, and the peak at 1360 cm ^-1 is broadly generated. These results show that the chemical bond is formed between the polyamide 66 and the boron nitride filler by mechanofusion and plasma treatment. On the other hand, in Comparative Example 2, it can be seen that chemical bonding between the polyamide 66 and the boron nitride filler was not formed.

Test Example  6: Infrared camera analysis

Through the above Example 3 and Comparative Example 3, infrared camera analysis was performed to determine whether the chemical bonding between the polyamide 66 and the boron nitride filler had an effect on the heat dissipation characteristics, and the temperature was measured over time.

8 (a) shows temperature changes of Example 3 and Comparative Example 3 while heating the bottom surface to 120 ° C after loading the composite specimen. In Example 3 in which the bond between polyamide 66 and boron nitride filler was formed, the maximum temperature rose to 119 ° C, whereas in Comparative Example 3 where no bond was formed, the maximum temperature rose only to 110 ° C. It was confirmed that the bond between polyamide 66 and boron nitride filler could improve the thermal conductivity and transfer the heat absorbed from the bottom to other surface. 8 (b) is a graph showing changes in temperature of the specimen with time while the temperature of the specimen of Example 3 and Comparative Example 3 is increased to 120 ° C. and then exposed to air and cooled. It was confirmed that Example 3 in which the bond between the polymer and filler was generated was cooled at a rate faster than that in Comparative Example 3. As a result, it was confirmed that the composite in which the bond between the polymer and the filler was formed had better heat radiation characteristics than the composite in which the bond was not formed.

Claims (13)

Polyamide; And a boron nitride filler dispersed on the surface of the polyamide and physically and chemically bonded to the polyamide,
Wherein the polyamide and the boron nitride filler are simultaneously mixed and mechanofusion and plasma treated. The method according to claim 1,
Wherein the polyamide is any one or two or more blends selected from a ring-opening polymer of a lactam compound, a polycondensation polymer of ω-aminoundecanoic acid, and a polycondensation polymer of a diamine and an organic acid. The method according to claim 1,
Wherein the polyamide is a blend of one or more selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610 and polyamide 612 Ride complex. The method according to claim 1,
The boron nitride filler may be selected from the group consisting of hexagonal boron nitride, wurtzite boron nitride, cubic boron nitride, boron nitride nanosheet, Wherein the polyamide / boron nitride composite is at least one selected from the group consisting of boron nitride nanotubes. The method according to claim 1,
Wherein the plasma is any one selected from a nitrogen plasma, an argon plasma, and an oxygen plasma. The method according to claim 1,
Wherein said polyamide / boron nitride composites comprise 95.5 to 79.5 wt% of polyamide and 4.5 to 20.5 wt% of boron nitride filler. The method according to claim 1,
Wherein at least one selected from nitrogen, argon and oxygen atoms is inserted into at least one surface selected from the polyamide and the boron nitride filler. The method according to claim 1,
Characterized in that at least one chemical bond selected from an amide bond, an amine bond, an ether bond, a carbonyl bond, an ethylene bond, an acetal bond and an urea bond is formed between the polyamide and the boron nitride filler Ride complex. (1) administering polyamide powder and boron nitride powder to a chamber of a dry high energy type mixer; And
(2) a step of producing a plasma in the chamber while simultaneously performing mechanofusion to prepare a composite in which boron nitride filler is dispersed and physically-chemically bonded to polyamide, and polyamide / boronite Lt; / RTI > 10. The method of claim 9,
Wherein the mechanofusion is carried out by rotating the chamber at a rate of 100 to 5000 rpm for 5 to 30 minutes under the condition that the pressure inside the chamber is 1.010 ² Pa to 1.010 ³ Pa. Lt; RTI ID = 0.0 > a < / RTI > boron nitride complex. 10. The method of claim 9,
Wherein said plasma generation and mechanofusion are performed in an atmosphere of air, nitrogen, argon or oxygen. 10. The method of claim 9,
Wherein the plasma generates a functional group containing a nitrogen atom or an oxygen atom on at least one surface selected from polyamide and boron nitride fillers. 13. The method of claim 12,
Wherein the functional group is at least one selected from the group consisting of an amide group, an amine group, a hydroxyl group, an aldehyde group, a carboxyl group, a carbonyl group and a urea group.

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