KR20200036620A - Thermoplastic elastic resin composition and product prepared by the same - Google Patents

Abstract

The present invention relates to a thermoplastic elastomer composition and a molded article prepared therefrom, and more particularly, to a thermoplastic elastomer composition having improved electrical conductivity and a molded article prepared therefrom. A thermoplastic elastic resin composition according to the present invention may have excellent elastic and heat resistance properties. In addition, the molded article prepared from the thermoplastic elastic resin composition according to the present invention is flexible without impact strength being lowered due to the elastic material base, and is excellent in electrical conductivity, and thus can be applied to products such as electrical and electronic equipment and conductive cables.

Description

Thermoplastic elastic resin composition and molded article prepared therefrom {Thermoplastic elastic resin composition and product prepared by the same}

The present invention relates to a thermoplastic elastomer composition and a molded article prepared therefrom, and more particularly, to a thermoplastic elastomer composition having improved electrical conductivity and a molded article prepared therefrom.

Conventionally, highly conductive metals such as aluminum, magnesium, and copper have been mainly used. These metals have a low electrical resistance value, and when used as an outer case of an electronic component, they have the advantage of exhibiting excellent effects not only for heat radiation but also for preventing electromagnetic interference.

However, since it has low moldability, productivity, and part design limitations, it is a trend to replace fillers with thermoplastics.

In addition, in addition to the exterior case of electronic components, cables and conductive elastic materials having excellent electrical properties have recently increased.

To compensate for this, elastic materials reinforced with various carbon materials such as carbon nanotubes, carbon nanofibers, carbon black, and graphite have been proposed. Thermoplastic elastomers have been developed in various types of thermoplastic elastomers (TPE), such as styrene type, urethane type, olefin type, and amide type. It has both the properties of elastic materials and the thermoplastic properties of ordinary plastic materials.

 In particular, polyester-based elastomers have excellent mechanical properties, and above all, have excellent repetitive fatigue and hinge properties and long-term durability compared to other types of elastomers, and have been widely used in various mechanical parts and automobile fields.

However, in general, in the case of a polyether ester elastomer resin, the polyether-based polyol used to realize the properties of the elastomer has a low melting point and also has a low heat resistance, so that the polymer chain decomposes due to heat and oxygen at high temperatures for a long time to degrade physical properties. There is a problem of discoloration. In addition, polymer materials including elastomers contain a large amount of various types of volatile substances, which may cause odor or release substances harmful to the human body, which meets the recent global demand for environmentally friendly issues. Problems that cannot be raised are also being raised.

Accordingly, various methods have been proposed to improve the heat resistance and weather resistance of the polyether ester elastomer resin. U.S. Patent Publication No. 3,723,427 discloses a method of applying a stabilizer of a tris (hydroxybenzyl) cyanurate type, which is a hindered phenol-based primary heat resistant agent, and U.S. Patent Publication 3,758,579 discloses a thioester ( Thioester), while presenting a secondary heat-resistant agent, disclosed a method of mixing with a phenol-based primary heat-resistant agent. In US Patent Publication No. 4,414,408, two types of stabilizers are mixed to promote a synergistic effect of improving the stability of the thermoplastic polyester elastomer resin, and US Patent Publication No. 4,405,749 discloses 1,3,5-tris- ( 2-hydroxyethy1) -s-triazine-2,4,6- (1H, 3H, 5H) trion) and 3,5-di-t-buty1-4-hydroxyhydrocinnamic acid are used to improve the stability of the polyester resin. A method for improving was disclosed.

However, even if a filler is included in the polyether ester resin of the prior art, it satisfies moldability, productivity, and component design, and is insufficient to improve mechanical properties and electrical conductivity properties.

Thus, the present inventors have made great efforts to solve the above problems, and by using a conductive filler mixed with a carbon material, confirms a thermoplastic elastic resin composition having excellent mechanical properties and electrical properties similar to metals, and completed the present invention. Was done.

Accordingly, the present invention is intended to provide a thermoplastic elastic resin composition having electrical properties and elasticity such as rubber and a molded product manufactured therefrom.

A first preferred embodiment of the present invention for solving the above problems is a polyether ester block copolymer; Conductive fillers; And a dispersant comprising a compound having a silane group, the conductive filler comprising 5 to 30 parts by weight of acicular carbon material with respect to 100 parts by weight of the polyether ester block copolymer; And it provides a thermoplastic elastic resin composition comprising 30 to 130 parts by weight of a plate-like carbon material.

Another preferred embodiment according to the present invention is a polyether ester block copolymer; Conductive fillers; And a dispersant comprising a compound having a silane group, the conductive filler comprising 5 to 30 parts by weight of acicular carbon material with respect to 100 parts by weight of the polyether ester block copolymer; It provides a thermoplastic elastic resin composition comprising 10 to 30 parts by weight of a spherical carbon material.

The polyether ester block copolymer according to the first embodiment has a Shore hardness of 70A to 95A or less and a melt flow index of 5g / 10min to 30g / 10min when measured at ISO 1133 measurement criteria at 230 ° C to 2.16kg. You can.

The acicular carbon material according to the first embodiment may be a carbon fiber having an aspect ratio (L / D) of 1 to 2,000.

The plate-like carbon material according to the first embodiment may include graphite and graphene.

The spherical carbon material according to the first embodiment may include kecheon black, carbon black.

The dispersant containing the compound having the silane group according to the first embodiment may be a compound having a structure in which at least one functional group and a silane group of an epoxy, carboxyl, and amine functional group are combined. .

Another preferred embodiment according to the present invention is to provide a molded article made of a thermoplastic elastic resin composition.

The thermoplastic elastic resin composition according to the present invention may have excellent elastic and heat resistance properties.

In addition, the molded article manufactured from the thermoplastic elastic resin composition according to the present invention is flexible without impact strength deterioration due to the elastic material base, and is excellent in electrical conductivity, and thus can be applied to products such as electrical and electronic and conductive cables.

One embodiment of the present invention is a polyether ester block copolymer; Conductive fillers; And a dispersant comprising a compound having a silane group, wherein the conductive filler is a needle-like carbon material; And a plate-like carbon material or a spherical carbon material, and the acicular carbon material is contained in an amount of 5 to 30 parts by weight based on 100 parts by weight of the polyether ester block copolymer, and the plate-like carbon material 30 It provides a thermoplastic elastic resin composition characterized in that it is contained in an amount of from 130 parts by weight or 10 to 30 parts by weight of the spherical carbon material.

Hereinafter, the present invention will be described in more detail.

[Polyether ester block copolymer]

The polyetherester block copolymer (Thermoplastic polyester Elastomer; TPEE) is composed of a hard segment (hard segment) composed of diol and dicarboxylate (or dicarboxylic acid) and a polyalkylene oxide containing an ester group. It consists of a soft segment (soft segment, soft chain) that is, dicarboxylate (or dicarboxylic acid) and polyether-based polyol after the first transesterification reaction (or esterification reaction), and then condensed in a separate reactor It may be a copolymer obtained in combination.

The diol may be butanediol (butylene glycol), monoethylene glycol, diethylene glycol, propylene glycol and neopentyl glycol, and the like, and the dicarboxylate (or dicarboxylic acid) may be dimethyl terephthalate, terephthalic acid, dimethyl Isophthalate, isophthalic acid, dimethylnaphthalate, naphthalenedicarboxylic acid, adipic acid and sebacic acid can be applied, and the polyether-based polyol is polyalkylene oxide such as polytetramethylene glycol, polyethylene glycol and polypropylene glycol. Can be applied.

The polyether ester block copolymer is not particularly limited as long as it has the properties of an elastomer, but specifically, it has a hard segment of butanediol and dimethyl terephthalate and polyoxytetramethylene glycol (PTMG) is made of a soft segment. desirable.

The hardness of the polyether ester block copolymer may be controlled by a soft segment (soft segment) and polyalkylene oxide containing an ether group, preferably based on the total weight of the polyether ester block copolymer, polyalkylene By including the oxide in an amount of 40 to 80% by weight, the surface hardness of the polyether ester block copolymer is ASTM D2240 measurement standard, Shore 70A to 95A, and in consideration of formability, measured at ISO 1133 measurement criteria 230 ℃ to 2.16kg At the time, it is advantageous that the melt flow index is 5 g / 10 min to 30 g / 10 min.

[Conductive filler]

The conductive filler is an inorganic material having electrical properties, and serves to reflect unwanted electromagnetic waves at the interface of the shield through the electrical conductivity of the material, and exhibits electrical properties by being uniformly dispersed in the polyether ester block copolymer.

As the conductive filler, acicular carbon materials such as carbon fiber, carbon nanotube (CNT), carbon nanofiber (CNF), graphite, expanded graphite, expanded graphite, graphene nanoplate, Plate-type carbon materials such as graphene, carbon black (CB), and spherical carbon materials such as kecheon black may be used. In the case of the needle-like carbon material, the resin itself has excellent electrical conductivity and serves to improve mechanical properties. The plate-like carbon material has an advantage of excellent conductivity when dispersing because it has a constant aspect ratio and has low contact resistance, and the spherical carbon material has an advantage of low cost and easy control of conductivity according to content control.

The conductive filler may realize excellent conductivity when using a conductive filler containing at least one of a plate-like carbon material and a spherical carbon material while including a needle-like carbon material.

At this time, the needle-like carbon material is preferably an aspect ratio (Aspect ratio, L / D) of 1 to 2,000 carbon fibers.

When the conductive filler is used as a filler containing a needle-like carbon material and a plate-like carbon material in a thermoplastic resin composition containing a polyether ester block copolymer, or when used as a filler comprising a needle-like carbon material and a spherical carbon material, needle-like type It can exhibit superior electromagnetic wave performance than fillers that use carbon materials or plate-like carbon materials independently. This improves the conductivity network by increasing the volume fraction of the filler present in the resin unit volume according to the shape of the material, while reducing the contact resistance between the conductive fillers by making surface contact between the plate-shaped or spherical carbon materials and the fiber-like carbon materials. It means that the conductivity is increased according to the factors to increase the conductivity.

In addition, the conductive filler is contained in an amount of 5 to 30 parts by weight of the acicular carbon material with respect to 100 parts by weight of the polyether ester block copolymer, 30 to 130 parts by weight of the plate-shaped carbon material, or 10 to 10 parts by weight of the spherical carbon material. Content of 30 parts by weight may be included. When the above range is satisfied, it is possible to uniformly disperse the conductive filler in the thermoplastic elastic resin, and to prevent a rapid rise in viscosity of the thermoplastic elastic resin composition, to prevent pressure and injection molding defects, and to achieve the required level of electrical conductivity. It may be more advantageous to obtain.

[Dispersant]

The dispersant may be a compound having a silane group, and preferably, a compound having a structure in which at least one functional group and a silane group of an epoxy, carboxyl, or amine group are combined.

The dispersant reacts with the terminal functional group of the polyether ester block copolymer and at least one functional group of an epoxy group, a carboxyl group, or an amine group, and at the same time, a silane group reacts with a conductive filler to increase the interfacial bonding force between the polyether ester block copolymer and the conductive filler. It has the advantage of realizing electrical characteristics and improving mechanical properties at the same time. In addition, the dispersant is preferably a compound having a structure in which an epoxy group or a carboxyl group functional group and a silane group are bonded in comparison with an amine group, in terms of improving the interface bonding force between the polyether ester block copolymer and the conductive filler.

The dispersing agent is preferably included in 0.1 to 3.0 parts by weight, more preferably 0.5 to 2.0 parts by weight based on 100 parts by weight of the polyether ester block copolymer. When the dispersant is contained in an amount of 0.1 to 3.0 parts by weight, the number of functional groups for improving the interfacial bonding force formed on the filler surface is sufficient to uniformly disperse the high and low conductive fillers, preventing aggregation between the conductive fillers, conductive performance and mechanical It may be more advantageous to obtain an effect capable of preventing deterioration of properties.

The thermoplastic elastic composition of the present invention is a heat resistant agent, antioxidant, light stabilizer, mold release agent, compatibilizer, dye, pigment, colorant, plasticizer, impact modifier, stabilizer, lubricant, etc. It may further include one or more additives selected from the group consisting of a mixture of.

The heat-resistant agent may further include 0.05 to 2 parts by weight of a hindered phenol-based heat-resistant agent with respect to 100 parts by weight of the polyether ester block copolymer in consideration of the durability improvement of the thermoplastic elastic resin composition, and the hindered The phenolic heat-resistant agent is a heat stabilizer, and may serve as an antioxidant as well as a role of improving the durability of an elastic body made of a polyether ester elastomer resin composition.

The hindered phenol-based heat-resistant agent is pentaerythritol tetrakis- (methylene)-(3,5 di-tert-buthyl-4-hydroxyx Phenyl (hydroxy phenyl) propionate can be used, and more specifically, the heat-resistant agent is 2,2'-m-phenylene bis (2-oxazoline) [2,2'-m-phenylene bis (2-oxazoline)], 4,4'-bis (α, α-dimethylbenzyl-disphenylamine) [4,4'-bis (alpha, alpha-dimethylbenzyl diphenylamine)] and N, N'-hexane-1 , 6-diyl bis (3- (3,5-di-tert-butyl-4-hydrocyphenyl-propionamide [N, N'-hexane-1,6-diyl bis (3- (3,5-di -tert-butyl-4-hydroxyphenyl propionamide)], or a mixture of two or more selected from the group consisting of, but is not limited thereto.

The antioxidant may be selected from among phenol type, phosphite type, thioether type and amine type, and the release agent is selected from among fluorine-containing polymers, silicone oils, metal stearate salts, metal monate salts, montanic acid ester waxes, and polyethylene waxes. It may be, but is not necessarily limited to this.

As a result, the present invention can provide a molded article from a thermoplastic elastic resin composition having excellent electrical conductivity and mechanical properties, and is particularly advantageous for injection and extrusion molding processing, electrical and electronic fields requiring conductive performance and mechanical properties, conductive cables, etc. It can provide a molded article that can be applied to products such as.

[Example]

Hereinafter, the present invention will be described in more detail through examples. These examples are only intended to illustrate the present invention in more detail, and the present invention is not limited thereby.

Examples 1 to 5 and Comparative Examples 1 to 5

A polyether ester block copolymer (TPEE) having a surface hardness of SHORE 85A (Kollon Plastics Co., Ltd., KOPEL ^® KP3328), a dispersant, and other additives were added in the amounts indicated in Table 1 below and mixed for 10 minutes using a tumbler mixer. N, N-hexane-1,6-diyl-bis (3- (3,5-di-tert-butyl-4-hydrocyphenyl propionamide) and 4,4′-bis (α, α- Dimethylbenzyl disphenylamine) was further added to the main hopper by adding the amount indicated in Table 1 below.

A needle-like carbon material of carbon short fibers (CF), a plate-like carbon material of graphite, and a spherical carbon material of Ketchen Black are selected as shown in Table 1 below, put into a side hopper, and inserted into a twin screw screw type extrusion kneader ( It was melt-kneaded through a twin screw extruder) to prepare an elastomer resin composition. At this time, the temperature of the extruder was set to 100 ° C, 150 ° C, 180 ° C, 200 ° C, 220 ° C in order from the primary inlet to the die, and the number of rotations of the screw was mixed under the conditions of 350 RPM.

Item TPEE
(Parts by weight) black smoke
(Parts by weight) Kecheon Black
(Parts by weight) CF
(Parts by weight) Epoxy
Silane
(Parts by weight) Heat Resistant-1
(Parts by weight) Heat Resistant-2
(Parts by weight) Example One 100 48 - 8 One One One 2 100 75 - 10 One One One 3 100 115 - 12 One One One 4 100 - 12 6 One One One Comparative example One 100 - - - - One One 2 100 26 - 7 One One One 3 100 150 - - One One One 4 100 75 - 10 - One One 5 100 - 6 - One One One 6 100 - 12 - One One One 7 100 160 - 8 One One One 8 100 - 40 6 One One One 9 100 - 6 6 One One One 10 100 48 - 45 One One One 11 100 48 - 2 One One One

-Kecheon Black: (Akzonobel, EC 300J)

-Heat Resistant-1: N, N'-hexane-1,6-diyl-bis (3- (3,5-di-tert-butyl-4-

Hydrocyphenyl propionamide)

-Heat-resistant agent-2: 4,4'-bis (α, α-dimethylbenzyl disphenylamine)

Property evaluation

The composition, which had been mixed from the extruder, was discharged onto a strand, solidified in a cooling bath having a temperature of 35 ° C., and then obtained as a pelletized product through a pelletizer. Tensile strength, impact strength, and surface resistance were measured as a reference.

-Tensile strength and tensile elongation: After the specimen was prepared according to ASTM D638, the maximum tensile strength and tensile elongation were measured.

-Impact strength: After preparing a 1/4 inch specimen according to ASTM D256, the impact strength of IZOD, Notched (IZOD) at room temperature (23 ° C) was measured.

-Surface resistance: According to JIS 7194, specimens of 60 mm X 60 mm X 1 mm (width X height X height) were prepared and evaluated through 4 probe methods.

Item The tensile strength
(MPa) Tensile elongation
(%) Izod
Impact strength
(J / m) 23 ℃ Surface resistance
(Ω / □) Example One 24 349 NB ~ 10 ² 2 27 315 NB ~ 10 ¹ 3 28 295 NB ~ 10 ⁰ 4 22 405 NB ~ 10 ⁰ Comparative example One 19 801 NB ~ 10 ¹⁶ 2 21 455 NB ~ 10 ¹⁰ 3 28 81 NB ~ 10 ⁶ 4 27 308 NB ~ 10 ³ 5 19 673 NB ~ 10 ¹⁰ 6 20 480 NB ~ 10 ⁴ 7 35 15 5 ~ 10 ⁰ 8 32 67 5 ~ 10 ² 9 28 51 NB ~ 10 ⁰ 10 23 350 NB ~ 10 ⁸ 11 23 420 NB ~ 10 ⁴

As a result of physical property measurement, Examples 1 to 4 according to the present invention include a polyether ester block copolymer, a conductive filler having two or more kinds of conductive carbon materials, and a compound having a silane group as shown in Table 2 above. By including the dispersing agent in the optimum range, it is possible to discount that the electrical properties are improved while having excellent tensile strength, tensile elongation and impact strength.

Examples 1 to 3 is a composition using graphite and carbon fibers as a conductive carbon material, it was confirmed that the mechanical properties are improved, the surface resistance is also excellent and the electrical properties are excellent as the graphite content is increased.

In Example 4, instead of graphite, kecheon black was used, and it was confirmed that it has excellent mechanical properties and electrical properties even when used in a smaller amount than graphite.

On the other hand, it was confirmed that Comparative Example 1 does not include a conductive filler, and thus significantly lowers tensile strength and surface resistance.

In Comparative Example 2, even if the carbon fiber was included in an appropriate range, when the graphite was included in an appropriate range and the surface resistance was 26 parts by weight of graphite, it was confirmed that the surface resistance was low and electrical properties were also low. 3, it was confirmed that low graphite electrical properties and low tensile elongation were lowered by including graphite in excess of the appropriate range.

Comparative Example 4 does not contain a dispersant, the dispersion of the conductive carbon material is not smooth, it was confirmed that the surface resistance is low compared to Example 2.

Comparative Example 5 and Comparative Example 6 is used as a conductive carbon material, while using only ketcheon black, is included below the appropriate range, the surface resistance is low, so it is not excellent in electrical properties, Comparative Example 7 is suitable for each graphite used as a conductive carbon material It was confirmed that the tensile elongation and the impact strength were lowered as being used beyond the range.

In Comparative Examples 8 and 9, it was confirmed that the ketcheon black used as the conductive carbon material was used outside the appropriate range, and the tensile strength was low, and the elastic force was decreased, and the impact strength was also affected.

In Comparative Examples 10 and 11, carbon fibers were used outside the appropriate range as conductive carbon materials, and it was confirmed that the electrical properties were not excellent due to low surface resistance.

The above description of the present invention is for illustration only, and those skilled in the art to which the present invention pertains can understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive.

Claims (8)

Polyether ester block copolymers; Conductive fillers; And a dispersant comprising a compound having a silane group,
The conductive filler is 5 to 30 parts by weight of acicular carbon material with respect to 100 parts by weight of the polyether ester block copolymer; And 30 to 130 parts by weight of a plate-like carbon material. Polyether ester block copolymers; Conductive fillers; And a dispersant comprising a compound having a silane group,
The conductive filler is 5 to 30 parts by weight of acicular carbon material with respect to 100 parts by weight of the polyether ester block copolymer; Thermoplastic elastic resin composition comprising 10 to 30 parts by weight of a spherical carbon material. The method according to claim 1 or 2, wherein the polyether ester block copolymer has a Shore hardness of 70A to 95A and an ISO 1133 measurement criterion of 2.16 kg at 230 ° C, a melt flow index of 5 g / 10 min to 30 g / 10 min. Thermoplastic elastic resin composition, characterized in that. [3] The thermoplastic elastic resin composition of claim 1 or 2, wherein the acicular carbon material is a carbon fiber having an aspect ratio (L / D) of 1 to 2,000. The thermoplastic elastic resin composition of claim 1, wherein the plate-like carbon material includes graphite and graphene. [Claim 3] The thermoplastic elastic resin composition of claim 2, wherein the spherical carbon material comprises ketcheon black and carbon black. The method of claim 1 or claim 2, wherein the dispersing agent containing a compound having a silane group is a compound having a structure in which at least one functional group and a silane group of an epoxy, carboxyl, or amine functional group are combined Thermoplastic elastic resin composition, characterized in that. A molded article made from the thermoplastic elastic resin composition according to any one of claims 1 to 7.