KR102576652B1 - Thermoplastic polyester-based elastomer resin composition for electrostatic discharge comprising carbon-based fillers and molded article comprising the same - Google Patents

Abstract

The present invention relates to a thermoplastic polyester-based elastomer resin composition for electrostatic discharge containing a carbon-based filler and a molded article containing the same, and more specifically, to a thermoplastic polyester-based elastomer and an adipic acid-based plasticizer in a specific content, A thermoplastic polyester elastomer resin for electrostatic discharge that exhibits an anti-static effect due to its excellent surface resistance despite containing a low content of carbon nanotubes, and does not deteriorate physical properties such as hardness, ductility, and elastic modulus compared to existing polyester elastomer resin composites. It relates to a composition and a molded article containing the same.

Description

Thermoplastic polyester-based elastomer resin composition for electrostatic discharge comprising carbon-based fillers and molded article comprising the same}

The present invention relates to a thermoplastic polyester-based elastomer resin composition for electrostatic discharge containing a carbon-based filler and a molded article containing the same, and more specifically, to a thermoplastic polyester-based elastomer and an adipic acid-based plasticizer in a specific content, A thermoplastic polyester elastomer resin for electrostatic discharge that exhibits an anti-static effect due to its excellent surface resistance despite containing a low content of carbon nanotubes, and does not deteriorate physical properties such as hardness, ductility, and elastic modulus compared to existing polyester elastomer resin composites. It relates to a composition and a molded article containing the same.

Recently, with the development of electronic product technology, electronic products have become smaller, more integrated, and higher-performing. Accordingly, electrically conductive materials are being used to prevent electrical damage that may occur during transportation and storage of materials such as electronic products and parts. .

Examples of those used for the above purposes include electronic component transfer carts, electronic component transfer pipe coating materials, and electronic component trays (IC trays) for thermoforming, as well as for transporting semiconductor chips between manufacturing processes and packaging them after manufacturing. It is being used.

The size and shape of the tray, etc. are determined depending on the type and type of the semiconductor chip, and can serve to prevent damage such as electrical shock due to dust, moisture, etc. to components on which circuits are printed.

The cart, pipe tray, etc. may include a heating process to remove moisture during the manufacturing process of the parts. For example, the tray containing the parts may be baked, so the material of the tray, etc. Physical properties such as heat resistance, stability before and after baking, low distortion, static dissipation, surface resistance, electrical conductivity, and low sloughing are required.

Conventionally, in order to satisfy the above physical properties, many materials using carbon fiber or carbon black have been used.

However, when carbon fiber or carbon black is included, there is a limitation in that it is difficult to improve formability and low sloughing characteristics. In addition, specifically, there is a problem that the formability is low due to the high carbon filler content and the carbon is smeared.

Thermoplastic polyester elastomer resins are being actively developed for applications that meet the requirements for long durability and increasingly high heat resistance of automobile parts by taking advantage of their excellent heat resistance, chemical resistance, and durability. The uses for automotive drivetrains are diverse, especially constant velocity joint boots belonging to the suspension system, gearbox bellows belonging to the steering system, air ducts and intercooler pipes around the engine, and dashboard skins or buttons as interior materials. Recently, the demand for conductive thermoplastic polyester elastomer resin has been increasing due to the development of electronic product accessories and wearable equipment.

In thermoplastic polyester-based elastomer resin, ductility and hardness can be said to be the most important characteristics of the polymer. When carbon-based filler is applied to improve electrical conductivity, the ductility and hardness of the elastomer polymer resin increase due to the high mechanical properties of the carbon-based filler. tends to rise very significantly, so a method to solve this is needed.

Therefore, there is a need for an elastomer polymer composite resin for electro-static discharge (ESD) that can exhibit the ductility and hardness of existing products while satisfying the electrical conductivity of thermoplastic polyester-based elastomer resin.

The object of the present invention is to provide a thermoplastic polyester-based elastomer and an adipic acid-based plasticizer in a specific content, and have excellent surface resistance despite containing a low content of carbon nanotubes, thereby exhibiting an anti-static effect, as well as existing polyester-based elastomer resin composites. The object of the present invention is to provide a thermoplastic polyester-based elastomer resin composition for electrostatic discharge that does not deteriorate physical properties such as hardness, ductility, and elastic modulus, and a molded article containing the same.

In order to solve the above technical problem, the present invention, based on a total of 100% by weight of the composition, (1) 60 to 90% by weight of thermoplastic polyester-based elastomer; (2) 1.5 to 14.5% by weight of carbon nanotubes; and (3) 6 to 34% by weight of an adipic acid-based plasticizer.

According to another aspect of the present invention, a molded article containing the thermoplastic polyester-based elastomer resin composition of the present invention is provided.

The thermoplastic resin composition according to the present invention exhibits an anti-static effect and does not deteriorate physical properties such as hardness, ductility, and elastic modulus compared to existing polyester-based elastomer resin composites, so that electrostatic discharge characteristics, hardness, ductility, and elastic modulus are required at the same time. It can be suitably used as a product material.

The present invention will be described in detail below.

The thermoplastic polyester-based elastomer resin composition of the present invention includes (1) a thermoplastic polyester-based elastomer, (2) carbon nanotubes, and (3) an adipic acid-based plasticizer. In one embodiment, the thermoplastic polyester-based elastomer resin composition of the present invention may further include other additives.

(1) Thermoplastic polyester elastomer resin

The thermoplastic polyester-based elastomer resin composition of the present invention includes thermoplastic polyester-based elastomer (TPEE).

The TPEE is a thermoplastic polymer that is block copolymerized into a hard segment and a soft soft segment.

In one embodiment, the hard segment includes polymerized units of aromatic dicarboxylic compounds and diols, and the soft segment includes polymerized units of polyalkylene oxide.

The aromatic dicarboxylic compounds include Terephthalic Acid (TPA), Isophthalic Acid (IPA), 1,5-Dinaphthalenedicarboxylic Acid (1,5-NDCA), 2,6-Dinaphthalenedicarboxylic Acid (2,6-NDCA), Dimethyl Terephthalate (DMT), Dimethyl Isophthalate, and combinations thereof may be used. It is possible, and preferably DMT can be used.

The diol may be a linear or cyclic aliphatic diol having 2 to 8 carbon atoms, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, One selected from 4-cyclohexanedimethanol and combinations thereof can be used, and 1,4-butanediol is preferably used.

The polyalkylene oxide may be selected from polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol (PTMEG), and combinations thereof, preferably PTMEG can be used.

According to one embodiment, the thermoplastic polyester elastomer may be branched by a branching agent to increase melt tension and improve the stability of the strand during TPEE production, thereby increasing productivity. there is. The branching agent may be selected from, for example, glycerol, pentaerythritol, neopentylglycol, and combinations thereof, and preferably glycerol.

TPEE that can be used in the present invention can generally be manufactured through melt polymerization consisting of two steps: oligomerization reaction and polycondensation reaction, and is preferably a branched thermoplastic polyester elastomer.

In one embodiment, the branched TPEE is subjected to an oligomerization reaction in the presence of an appropriate catalyst (e.g., tetra-n-butoxy titanium (TBT)) after the above components are added to the reactor. It can be manufactured through melt polymerization, which consists of two steps: and polycondensation reaction. The oligomerization reaction can proceed for 3 to 4 hours at 140 to 215 ° C, and the polycondensation reaction can be carried out for 4 to 5 hours at 210 to 250 ° C. The process can be progressed by gradually depressurizing from 760 torr to 0.3 torr over a period of time.

In one embodiment, considering mechanical strength, flexibility, etc., the soft segment content in the TPEE is preferably 5 to 75% by weight, more preferably 30 to 70% by weight, based on 100% by weight of the total TPEE. If the soft segment content in TPEE is too small, the hardness of TPEE increases, making it difficult to expect flexibility. Conversely, if the polyalkylene oxide content is too high, it is difficult to expect high heat resistance performance.

According to one embodiment, the intrinsic viscosity of the TPEE may be 1.7 to 2.2 dl/g, and more preferably 1.9 to 2.0 dl/g.

Additionally, according to one embodiment, the shore hardness D of the TPEE may be 25 to 45, and more preferably 25 to 35.

100% by weight of the thermoplastic polyester elastomer resin composition of the present invention preferably contains 55 to 90% by weight, more preferably 65 to 85% by weight, and even more preferably 70 to 83% by weight. . If the TPEE content in the resin composition is lower than the above level, there may be a problem of reduced resilience, and conversely, if it is higher than the above level, there may be a problem that it is not easy to suppress swelling.

In one embodiment, the thermoplastic polyester-based elastomer resin composition of the present invention may include 60 to 90% by weight of thermoplastic polyester-based elastomer, based on 100% by weight of the total composition. If the thermoplastic polyester-based elastomer content in 100% by weight of the resin composition is excessively lower than the above level, existing physical properties such as processability, tensile strength, elongation, and hardness may be poor, and conversely, if it is excessively higher than the above level, the content of other components may be relatively low. may be lowered to increase the surface resistance.

More specifically, the content of the thermoplastic polyester-based elastomer in 100% by weight of the thermoplastic resin composition of the present invention may be 60% by weight or more, 65% by weight or more, or 69% by weight or more, and may be 90% by weight or less, 85% by weight or less, or It may be 81% by weight or less.

(2) Carbon nanotubes

The type of carbon nanotubes that can be included in the thermoplastic polyester-based elastomer resin composition of the present invention is not particularly limited, and carbon nanotubes commonly used in this field can be used without limitation. For example, the carbon nanotube may be a single-walled carbon nanotube (SWNT), a multi-walled carbon nanotube (MWNT), or a combination thereof. According to one embodiment of the present invention, it may be a multi-walled carbon nanotube.

The thermoplastic polyester-based elastomer resin composition of the present invention may contain 1.5 to 14.5% by weight of carbon nanotubes based on 100% by weight of the total composition. If the carbon nanotube content in 100% by weight of the resin composition is excessively lower than the above level, the surface resistance of the molded product manufactured from the resin composition may be too high, and the electrostatic discharge effect due to the addition of carbon nanotubes may be insignificant. Conversely, if it is excessively higher than the above level, the processability may be reduced. , tensile strength may become poor.

More specifically, the carbon nanotube content in 100% by weight of the thermoplastic resin composition of the present invention may be 1.5% by weight or more, 2% by weight or more, or 3% by weight or more, and may also be 14.5% by weight or less, 12% by weight or less, and 10% by weight or less. % or less or 7% by weight or less.

(3) Adipic acid-based plasticizer

The thermoplastic polyester-based elastomer resin composition of the present invention contains adipic acid or adipic acid ester as an adipic acid-based plasticizer, which is used to facilitate control of hardness of the resin composition and to have a low elastic modulus.

The adipic acid ester may be a dialkyl ester of adipic acid or adipic acid polyester. As the dialkyl ester of adipic acid, for example, di(C4-C12 alkyl) ester of adipic acid may be used, and more specifically, di(C6-C10 alkyl) ester of adipic acid may be used. .

In one embodiment, the adipic acid or adipic acid ester is adipic acid, dioctyl adipic acid, 2-diethyl hexyl adipic acid, diisononyl adipic acid. Dioctyl adipate, di(2-ethylhexyl) adipate, diisononyl adipate, adipic acid Polyesters selected from adipic acid polyester and combinations thereof may be used, and diisononyl ester of adipic acid may be preferably used.

The thermoplastic polyester-based elastomer resin composition of the present invention may include 6 to 34% by weight of an adipic acid-based plasticizer based on a total of 100% by weight of the composition. If the adipic acid-based plasticizer content in 100% by weight of the resin composition is excessively lower than the above level, the hardness and elastic modulus may increase, which may result in problems making it unsuitable for use compared to existing resin compositions. Conversely, if it is higher than the above level, migration and insufficient adhesion may occur. Extrusion processability becomes poor, and modulus and hardness may decrease significantly.

More specifically, the adipic acid-based plasticizer content in 100% by weight of the thermoplastic resin composition of the present invention may be 6% by weight or more, 10% by weight or more, 12% by weight or more, or 15% by weight or more, and may be 34% by weight or less, 30% by weight or more. It may be less than 28% by weight, or less than 25% by weight.

(4) Other additives

In addition to the above components, the thermoplastic resin composition of the present invention may further include one or more additives commonly used in thermoplastic resin compositions, such as light stabilizers, heat stabilizers, antioxidants, nucleating agents, lubricants, pigments, dyes, It may contain one or more of a release agent and general carbon black.

In one embodiment, the light stabilizer includes 2-(2'-hydroxyphenyl)-benzotriazole, 2-hydroxy-benzophenone, and 2-(2'-hydroxy-5'-octylphenyl)benzotria. Sol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(4,6-diphenyl-1,3,5-tri Azin-2-yl)-5-hexyloxy-phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol or 2,2' -Methylenebis(6-(2H-benzotriazol-2-yl))-4-(1,1,3,3-tetramethylbutyl)phenol, etc. can be used.

In one embodiment, the heat stabilizer may be bisphenol A epoxy resin, monocarbodiimide, or polycarbodiimide.

In one embodiment, the antioxidant includes tris(nonylphenyl)phosphite, (2,4,6-tri-tert-butylphenyl)(2-butyl-2-ethyl-1,3-propanediol)phosphite, , tris(2,4-dibutylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butyl-4-methylphenyl) Organophosphorus antioxidants such as pentaerythritol diphosphite or distearyl pentaerythritol diphosphite, pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) pro Phenolic antioxidants such as cypionate or octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis(3-dodecylthiophenyl)propionate Thioester-based antioxidants such as Nate) can be used.

In one embodiment, the nucleating agent may be talc, mica, silicate, ionomer, sodium 2,2'-methylene-bis-(4,6-di-tert-butylphenyl)phosphate, etc.

In one embodiment, the lubricant may be a long chain ester of pentaerythritol or stearyl stearate.

In one embodiment, pigments, dyes, release agents, and general carbon black can be used that are generally commercially available.

According to another aspect of the present invention, a molded article containing the thermoplastic polyester-based elastomer resin composition of the present invention is provided.

In one embodiment, the molded article of the present invention may be manufactured by extruding, casting, blow molding, or injection molding a melt of the thermoplastic resin composition of the present invention.

In one embodiment, the molded article of the present invention may be an electronic component transfer cart, an electronic component transfer pipe coating material, or an electronic component tray for thermoforming.

Hereinafter, the present invention will be described in more detail through examples and comparative examples. However, the scope of the present invention is not limited to these.

[Example]

Thermoplastic resin compositions of Examples 1 to 7 and Comparative Examples 1 to 8 were prepared by mixing the components and amounts shown in Tables 1 and 2. Afterwards, extrusion of each thermoplastic resin composition was performed using a 32-pi twin screw extruder at 230°C to 250°C and 200 rpm to 250 rpm, and an injection molding machine with a clamping force of 100 to 200 tons was used under the same temperature conditions. An injection specimen was manufactured using. In the case of injection specimens for measuring mechanical properties, injection specimens meeting each ASTM standard were manufactured to be suitable for measuring tensile strength and flexural strength.

(1) Thermoplastic polyester-based elastomer (TRIEL 5401NA, Samyang Corporation)

(2-1) Carbon nanotube: Bundle chip type MWCNT (tube diameter 7~15 nm)

(2-2) Carbon nanotube: Powder type MWCNT (tube diameter 9~10 nm)

(3-1) Adipic acid-based plasticizer (Mw 500)

(3-2) Terephthalate plasticizer (Mw 400)

(4) Other additives: antioxidants, mold release agents

[Physical property evaluation]

(1) Surface resistance

The surface resistance of the manufactured injection specimen was measured using Mitsybushi Chemical Analytech's HirestaUX equipment and LorestGX equipment. The results measured by the device are displayed as ^{a 10}

(2) Processability

In the process of manufacturing an injection specimen using a thermoplastic resin composition, considering gas generation during extrusion and injection, swell phenomenon, and constant input of raw materials, the degree to which overall processability was excellent was evaluated in five stages as follows.

- Very good: No problems mentioned above during extrusion.

- Excellent: The above-mentioned problems exist slightly during extrusion, but there are no problems at all in production.

- Good: The above-mentioned problems exist during extrusion, but there are no problems in production.

- Normal: The above-mentioned problems exist during extrusion, and the swell phenomenon is particularly severe, causing problems in production.

- Defect: Overall problems such as gas generation during extrusion, swell phenomenon, and raw material input are so serious that production is difficult.

(3) Tensile strength: Tensile strength was measured according to ASTM D638.

(4) Tensile elongation: Tensile elongation was measured according to ASTM D638.

(5) Modulus: Modulus was measured according to ASTM D638.

(6) Shore D hardness: Shore D hardness was measured according to ASTM D2240 (Table 1)

[Table 1]

[Table 2]

As can be seen in Table 1, the thermoplastic polyester-based elastomer resin compositions of Examples 1 to 7 according to the present invention exhibit similar levels of tensile strength, tensile elongation, and hardness to Comparative Example 1, which is a conventional TPEE composition. , it was confirmed that the surface resistance was lower and the electrostatic discharge effect was excellent.

However, as can be seen in Table 2, in the case of the compositions of Comparative Examples 2 to 4 using a terephthalate-based plasticizer, which is a different type of plasticizer, the processability was significantly reduced, and the mechanical properties (tensile strength, modulus, hardness) were also significantly reduced. was able to confirm.

In the case of Comparative Example 5, which contained a smaller amount of adipic acid-based plasticizer than the appropriate amount, the tensile strength, modulus, and hardness increased significantly, and the properties of TPEE could not be realized. On the contrary, in the case of Comparative Example 6, in which an excessive amount of adipic acid-based plasticizer was included, extrusion processability was poor due to migration and insufficient adhesion, and the modulus and hardness were greatly reduced.

The composition of Comparative Example 7, which contained a small amount of carbon nanotubes (CNTs), did not lower the surface resistance as much as desired, and in the case of Comparative Example 8, which contained an excessive amount of CNTs, processability was poor and the tensile strength and tensile elongation were significantly reduced. It was confirmed that the modulus and hardness increased significantly and the elastomer properties were lost.

Claims (9)

Based on 100% by weight of the total composition,
(1) 69 to 79.4% by weight of thermoplastic polyester-based elastomer;
(2) 5 to 7% by weight of carbon nanotubes; and
(3) 15 to 25% by weight of adipic acid-based plasticizer;
Thermoplastic polyester-based elastomer resin composition. The method of claim 1, wherein the thermoplastic polyester-based elastomer comprises: a hard segment containing polymerized units of an aromatic dicarboxylic compound and a diol; And a soft segment containing polymerized units of polyalkylene oxide. A thermoplastic polyester-based elastomer resin composition comprising a. According to paragraph 2,
the aromatic dicarboxylic compound is selected from terephthalic acid, isophthalic acid, 1,5-dinaphthalene dicarboxylic acid, 2,6-dinaphthalene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, and combinations thereof;
the diol is selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and combinations thereof;
A thermoplastic polyester-based elastomer resin composition, wherein the polyalkylene oxide is selected from polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, and combinations thereof. The thermoplastic polyester-based elastomer resin composition of claim 1, wherein the adipic acid-based plasticizer is a dialkyl ester of adipic acid, adipic acid polyester, or a combination thereof. The method of claim 1, wherein the adipic acid-based plasticizer is adipic acid, dioctyl adipic acid, 2-diethyl hexyl adipic acid, and diisononyl adipic acid. A thermoplastic polyester-based elastomer resin composition selected from dioctyl ester of adipic acid, di(2-ethylhexyl) ester of adipic acid, diisononyl ester of adipic acid, adipic acid polyester, and combinations thereof. . The thermoplastic polyester-based elastomer resin composition of claim 1, wherein the carbon nanotubes are multi-walled carbon nanotubes. The thermoplastic polyester-based elastomer resin composition of claim 1, further comprising one or more additives selected from light stabilizers, heat stabilizers, antioxidants, nucleating agents, lubricants, pigments, dyes, mold release agents, and general carbon black. A molded article comprising the thermoplastic polyester-based elastomer resin composition of any one of claims 1 to 7. The molded article according to claim 8, which is an electronic component transfer cart, an electronic component transfer pipe coating material, or an electronic component tray for thermoforming.