KR20180106598A

KR20180106598A - Manufacturing Method of Molded Article Comprising ABS or MPPO Composite Materials

Info

Publication number: KR20180106598A
Application number: KR1020170035177A
Authority: KR
Inventors: 강명구
Original assignee: 강명구
Priority date: 2017-03-21
Filing date: 2017-03-21
Publication date: 2018-10-01

Abstract

The present invention relates to a manufacturing method of a molded article obtained by mixing a polycaprolactam master batch and an acrylonitrile-butadiene-styrene (ABS) resin or a modified polyphenylene oxide (MPPO) resin, and molding the mixture. The polycaprolactam master batch is produced by the following steps: dispersive-mixing ε-caprolactam and a polymerization catalyst to prepare polycaprolactam; and mixing carbon nanotubes with the polycaprolactam and molding the mixture to prepare pellets. The polycaprolactam master batch and the ABS resin or the MPPO resin are mixed and molded at 180 to 210°C. The molded article of the present invention exhibits excellent antistatic properties even with a small amount of carbon nanotubes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a molded article comprising a composite material of ABS resin or MPPO resin,

The present invention relates to a method of producing a molded article comprising a composite material of ABS (acrylonitrile-butadiene-styrene) resin or MPPO (Modified Polyphenylene Oxide) resin, and more particularly, And more particularly, to a method of manufacturing a molded article capable of manufacturing a tray used in an electronic component manufacturing process.

In the manufacturing process of electronic parts, a tray formed by molding a sheet of a polymer resin material is used for transferring and packaging parts, and the like. These trays must be made of materials that are durable and impact resistant without generating static electricity because they must contain electronic components that are easily damaged by static electricity.

Since a general polymer resin has a surface resistivity of 10 ¹³ Ω or more, static electricity is easily generated and it is not suitable for use as a tray for such an electronic component. For this reason, a conductor such as an antistatic agent or carbon black is added, To form a coating layer. Particularly, ABS (acrylonitrile-butadiene-styrene) resin having excellent impact resistance and heat resistance is widely used as a material for such trays.

Accordingly, in Korean Patent Laid-Open Publication No. 10-2008-0035058, a tray is manufactured using a multi-layered multilayer sheet of PC / ABS / PC to obtain abrasion resistance, impact resistance and antistatic characteristics. Korean Patent Publication No. 10-0560045 A tray is manufactured through a five-layered synthetic resin sheet obtained by laminating a semiconductive layer formed by mixing EVA, LLDPE, and a liquid antistatic agent on both sides of a main sheet. Korean Patent Publication No. 10-2011-0096884 and Korean Patent Publication No. 10-0560045 disclose a surface layer comprising an ABS resin as a center layer and an ABS resin and a carbon nanotube on a surface thereof, And an effect of not generating a foreign substance is obtained.

However, the above-mentioned prior arts have been complicated in the process because the resin for the tray is manufactured through the method of laminating the coating layer on the surface based on the ABS resin, but the durability is higher than that of the conventional coating method, So that durability is deteriorated.

Korean Patent Publication No. 10-2008-0035058 Korean Patent Publication No. 10-0560045 Korean Patent Publication No. 10-2011-0096884 Korean Patent Publication No. 10-0560045 Korean Patent Publication No. 10-1417945 Korean Patent Publication No. 10-1612545 Korean Patent Publication No. 10-2015-0028698

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above problems of the prior art, and it is an object of the present invention to provide an ABS resin or an MPPO resin with high dispersion of carbon nanotubes, thereby exhibiting excellent antistatic characteristics even when using a small amount of carbon nanotubes, It is an object of the present invention to provide a method of manufacturing a molded article comprising a material of ABS resin or MPPO resin composite which is simple in manufacturing process but has excellent physical properties because it has no structure.

Another object of the present invention is to provide a method for producing a molded article comprising a composite material of ABS resin or MPPO resin excellent in moldability so as to be suitable for an electronic component tray.

In order to accomplish the above object, the present invention provides a process for producing a molded article comprising a composite material of ABS resin or MPPO resin, which comprises mixing a polycaprolactam master batch with an ABS resin or an MPPO resin to form the polycaprolactam master The batch is prepared by dispersively mixing? -Caprolactam and a polymerization catalyst to prepare polycaprolactam; And mixing and molding the carbon nanotubes with the polycaprolactam to form pellets, wherein the polycaprolactam master batch and the ABS resin or the MPPO resin are mixed at 180 to 210 ° C.

Also, the pellet is prepared by press molding at 220 to 250 ° C, and the? -Caprolactam and the carbon nanotube are contained in a weight ratio of 5: 5 to 7: 3.

Further, the molded article comprising the ABS resin or the composite material of MPPO resin is characterized by containing 0.5 to 1.5% by weight of the carbon nanotubes based on the total weight.

In the present invention, the molded article comprising the composite material of ABS resin or MPPO resin may be a tray for electronic parts used for transferring or packaging of electronic parts.

The method for producing a molded article according to the present invention has excellent antistatic characteristics even when a small amount of carbon nanotubes are used by incorporating carbon nanotubes into ABS resin or MPPO resin with high dispersion and does not have a coating layer or laminated structure, But also a molded body having excellent physical properties can be produced.

Particularly, it is possible to provide a method of manufacturing a molded article comprising an ABS resin or an MPPO resin composite material excellent in moldability so as to be suitable for an electronic component tray.

1 is a photograph of a prototype of a carbon nanotube master batch (a), an ABS resin pellet (b) containing the master batch, and an electronic part tray (c) manufactured by molding the ABS resin pellet.

Hereinafter, the present invention will be described in more detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The polycaprolactam formed by polymerization of? -caprolactam is generally called nylon-6, and is known as a medium suitable for dispersion of carbon nanotubes. That is, when a carbon nanotube is mixed with a polymer of? -Caprolactam as a filler in Korean Patent Publication Nos. 10-1417945, 10-1612545 and 10-2015-0028698, carbon nanotubes It is known that even if contained in a high content, the dispersibility is excellent.

In the present invention, a resin masterbatch is produced by using the conventional carbon nanotube dispersion technique, and an ABS resin molded body is produced through the resin masterbatch, thereby obtaining a molded body in which carbon nanotubes are highly dispersed.

In general, polycaprolactam should be heated to a temperature of 220 to 250 ° C. for molding. Since the molding temperature of ABS is about 200 ° C., it is difficult to produce a composite resin merely by mixing polycaprolactam and ABS resin. Therefore, it has been found preferable to prepare and apply polycaprolactam to the master batch so that molding can be performed in a temperature range of 180 ~ 210 ° C, which is an ABS molding condition.

In the present invention, the polycaprolactam master batches are disclosed in Korean Patent Publication Nos. 10-1417945, 10-1612545, and 10-2015-0028698, which are well known in the art, The manufacturing process is optimized.

That is, the polycaprolactam master batch is prepared by dispersing and mixing? -Caprolactam and a polymerization catalyst to produce polycaprolactam, and mixing the polycaprolactam with carbon nanotubes followed by molding to produce pellets do.

The polymerization of? -Caprolactam can be carried out under ordinary polymerization conditions. As the polymerization catalyst, a conventional metal catalyst or an organometallic catalyst may be used, and it is preferable to use titanium tetraoxide (TiO ₄ ). The polymerization catalyst is preferably mixed in an amount of 0.5 to 1.0 mol% with respect to? -Caprolactam, and polycaprolactam is produced through the reaction.

The polycaprolactam may be uniformly dispersed by mixing the carbon nanotubes while maintaining the polycaprolactam at a temperature of about 250 ° C, which is a temperature above the melting point. The mixing can be carried out using a Sinky mixer, a ball mill, have. Since the viscosity of the polycaprolactam is remarkably reduced at the above temperature, very uniform dispersion is possible even when the carbon nanotubes are mixed in powder form. The use of polycaprolactam in comparison to other polymers has been shown to be particularly effective in dispersing carbon nanotubes, which is believed to be related to the viscosity of polycaprolactam at high temperatures.

Further, in a state where the carbon nanotubes are highly dispersed, a low surface resistance can be secured even if a small amount is used. Korean Patent Publication No. 10-0610888 discloses that when ABS resin is mixed with carbon nanotubes in an amount of 0.6 to 1.6 wt%, physical properties having a surface resistance of 10 ² to 10 ¹² Ω are obtained. However, In the present invention in which the carbon nanotubes are dispersed in the whole of the formed body due to the surface resistance of the coating layer of the carbon nanotubes.

When a process of dispersing such carbon nanotubes at a high temperature is performed, there is a problem that a large number of pores are generated. Therefore, after compounding the master pellets by the compounding step, they are mixed with the master batch and the ABS resin or MPPO resin, It is possible to prevent occurrence of deterioration of mechanical properties and to ensure excellent workability.

Further, it was found that when preparing the master batch, it is preferable to mix the? -Caprolactam and the carbon nanotube in a weight ratio of 5: 5 to 7: 3. That is, if the content of carbon nanotubes is too large, the polymerization of epsilon -caprolactam does not occur smoothly and dispersion of carbon nanotubes becomes uneven. Therefore, the content should not be used more than the above range. If the content is too small, Or MPPO resin, the carbon nanotube content in the final molded body can not be adjusted, and the electrostatic properties are deteriorated.

In the present invention, the ε-caprolactam serves as a mediator for dispersing the carbon nanotubes, and the electrical conductivity of the molded product is achieved by the ABS resin. However, the amount of the carbon nanotubes, which are expensive raw materials, It is necessary to optimize the weight ratio of? -Caprolactam and the carbon nanotube in a weight ratio of 5: 5 to 7: 3, since it is necessary to achieve high dispersion of carbon nanotubes in order to obtain physical properties usable for the same shaped body. The dispersibility of the carbon nanotubes can be improved by adding an additive such as a dispersant. However, considering that the temperature for preparing the master batch is 220 ° C or higher, addition of a dispersant such as a surfactant is not effective.

In the present invention, in order to produce the master batch, the pellets are produced by mixing and press-molding the carbon nanotubes and? -Caprolactam at a temperature of 220 to 250 ° C, ° C., it is possible to smoothly mix with ABS resin or MPPO resin at 180 to 210 ° C. which is the general molding temperature of ABS resin or MPPO resin.

ABS resin pellets can be prepared by mixing the master batch with an ABS resin or an MPPO resin and by press molding. The pellets are heated to 180 to 210 ° C in order to produce a tray for electronic parts, And then extruding the sheet to prepare a sheet, placing the sheet in a molding machine, and molding the sheet into a tray of a desired shape.

When the masterbatch is once mixed with the ABS resin or the MPPO resin and then heated to a temperature higher than the molding temperature range, the carbon nanotubes dispersed in the masterbatch are diffused into the ABS resin or the MPPO resin, Respectively. Therefore, once the ABS resin or the MPPO resin pellets are produced, it is preferable that the pellets are molded under the condition that they do not deviate from the temperature range of 180 to 210 deg. In addition, it is also possible to produce a molded article directly with a molding machine in a state in which a master batch and an ABS resin or MPPO resin are mixed without producing pellets of ABS resin or MPPO resin.

The molded product produced by the molding method of the present invention preferably contains carbon nanotubes in an amount of 0.5 to 1.5% by weight based on the total weight. Within the above range, the surface resistance of 10 ⁵ Ω or less Respectively. That is, when the content of carbon nanotubes is too small, the surface resistance exceeds 10 ⁵ Ω. When the content of carbon nanotubes is too large, uneven dispersion occurs due to the arrangement, and electrostatic properties are changed, appear.

The results of evaluating the characteristics of trays for electronic parts according to the manufacturing method of the present invention will be described with reference to the following examples.

Carbon nanotubes were multi-walled carbon nanotubes supplied from Hanwha Nanotech, which were directly used without pretreatment and were mixed with? -Caprolactam in the weight ratio shown in Table 1. The mixed resin and the carbon nanotubes were polymerized by kneading at 240 DEG C for 1 hour, and then press-molded at a pressure of 20 MPa for 2 minutes to prepare a master batch.

The prepared master batch and the ABS resin were compounded so that the final carbon nanotube content was in the range of 0.5 to 1.5 wt%, and the compounding process was performed at the ABS molding temperature shown in Table 1. The compounding process was carried out using SM PLATEX's TEX 20 model, and the temperature from the barrel to the nozzle was maintained in the range of 180 to 210 ° C. The screw and the mixing speed were set to 300 rpm and 30 rpm, respectively.

The pellets were extruded to prepare a sheet member, which was then placed on a molding machine and heated to produce a tray for electronic parts.

The masterbatch and the MPPO resin were also compounded in the same manner as described above and subjected to a compounding process under the conditions shown in Table 2 to prepare a tray for electronic parts.

The surface resistance was measured for the tray using an SRM-200 resistance meter of Wolfgang Warmbier under the conditions of applied voltages of 500 V, 60 seconds, 20 2 C, and 30 2% RH.

The abrasion resistance of the pellet was measured by measuring the weight after the pellet was formed into a disc shape, mounted on a rotating mechanism, rotated 1,000 times, and worn with a wearer.

Caprolactam: CNT
(Weight ratio) ABS molding temperature
(° C) CNT content
(weight%) Surface resistance
(Ω) Abrasion resistance
(Mg / 1000 times) Example 1 7: 3 200 1.0 1.5 x 10 ³ 8.0 Example 2 6: 4 190 1.2 1.2 x 10 ⁴ 8.7 Example 3 5: 5 200 1.0 1.2 x 10 ⁴ 8.5 Comparative Example 1 4: 6 200 1.4 1.6 x 10 ⁸ 10.3 Comparative Example 2 3: 7 200 1.2 1.4 × 10 ¹² 11.2 Comparative Example 3 7: 3 220 1.0 1.5 x 10 ⁹ 9.8

Caprolactam: CNT
(Weight ratio) MPPO molding temperature
(° C) CNT content
(weight%) Surface resistance
(Ω) Abrasion resistance
(Mg / 1000 times) Example 4 7: 3 200 1.0 1.8 x 10 ⁴ 7.4 Example 5 6: 4 190 1.2 5.8 x 10 ⁴ 8.4 Example 6 5: 5 200 1.0 6.2 × 10 ⁴ 8.2 Comparative Example 4 4: 6 200 1.4 2.6 x 10 ⁹ 11.8 Comparative Example 5 3: 7 200 1.2 3.4 × 10 ¹¹ 12.4 Comparative Example 6 7: 3 220 1.0 1.5 × 10 ⁸ 10.2

The results of Table 1 and Table 2 show that when the content of caprolactam and carbon nanotubes is in the range of 5: 5 to 7: 3, the surface resistivity of the formed body is 1 x 10 ⁵ Ω or less, ㎎ or less. However, in Comparative Examples 1 and 2 in which the content of carbon nanotubes was too large, the amount of abrasion loss was greatly increased and the surface resistance was increased, which was not preferable. In addition, even when the content of caprolactam and carbon nanotubes was optimized, a higher molding temperature resulted in poor surface resistance and wear reduction. This is because when the temperature is raised to the manufacturing temperature range of the master batch, the dispersibility of the carbon nanotubes deteriorates in the process of compounding with the resin. When the molding temperature is increased to 230 and 240 ° C, This tendency was confirmed by the fact that it was bad.

The electrical conductivity of the tray of Example 1 containing 1 wt% of carbon nanotubes was measured and found to be 1.92 x 10 < ^-1 > S / m, which was 1.58 x 10 < ^-2 & gt ^; S / m Respectively.

From these results, it can be seen that the method of manufacturing a molded article according to the present invention can prevent generation of dust due to abrasion due to abrasion of upper and lower sides in the process of transferring electronic parts and maintains a surface resistance of 10 ⁵ Ω or less, It can be confirmed that this method is suitable for manufacturing a tray for parts.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and that various changes and modifications may be made therein without departing from the spirit and scope of the invention. Change is possible. Such variations and modifications are to be considered as falling within the scope of the invention and the appended claims.

Claims

A process for producing a molded article by mixing a polycaprolactam master batch with an ABS resin (acrylonitrile-butadiene-styrene) resin or MPPO (Modified Polyphenylene Oxide)
The polycaprolactam master batch may contain,
dispersing the? -caprolactam and the polymerization catalyst to prepare polycaprolactam;
Mixing the carbon nanotubes with the polycaprolactam and molding the mixture to form pellets,
Wherein the polycaprolactam master batch and the ABS resin or the MPPO resin are mixed at 180 to 210 ° C.

The method according to claim 1,
Wherein the pellet is manufactured by press molding at 220 to 250 ° C.

The method according to claim 1,
Wherein the ε-caprolactam and the carbon nanotube are contained in a weight ratio of 5: 5 to 7: 3.

The method according to claim 1,
Wherein the molded article comprising the ABS resin composite material contains 0.5 to 1.5% by weight of carbon nanotubes based on the total weight of ABS resin or MPPO resin composite material.

5. The method according to any one of claims 1 to 4,
Wherein the molded article is a tray for an electronic part.