KR20240028699A - Conductive foam composition of expressing color - Google Patents

Abstract

The present invention relates to a conductive foam composition capable of expressing color, has excellent anti-static performance, and is transparent, allowing various colors to be expressed in products.
In the conductive foam composition capable of developing color, 20 to 40 parts by weight of an antistatic agent based on 100 parts by weight of ethylene vinyl acetate copolymer (EVA); 5 to 10 parts by weight of metal oxide; 1 to 2 parts by weight of stearic acid; 10 to 20 parts by weight of hard coal; 1 to 2 parts by weight of hardener; 5 to 15 parts by weight of foaming agent; and 50 to 70 parts by weight of polar rubber.

Description

Conductive foam composition capable of expressing color

The present invention relates to a conductive foam composition capable of developing color, which has excellent anti-static performance, realizes transparency, and is capable of expressing various colors in finished products.

Foam, which has a unique characteristic of cushioning, is used for various purposes in real life or modern industry, such as building materials, automobile interior materials, and shoes, due to the functionality of cushioning.

However, most of the conventional polymer substrates mainly used in the production of such foams are non-polar materials, and the foam is damaged due to friction between the manufactured foams, friction between the foams and other materials, or electrical external force around the foams. There was a problem that static electricity was generated by easily charging the material itself or charging the opposing material.

Accordingly, the use of conductive polymers or conductive additives is necessary to provide electrical conductivity to the polymer substrate applied to the foam. However, conductive polymers are more expensive than general polymer substrates and it is difficult to manufacture foam using existing manufacturing processes. A method of imparting electrical conductivity to a polymer substrate using a conductive additive is mainly used.

For example, Korea Patent Publication No. 10-2008-0097007 discloses that when a display panel containing low-density polyethylene resin, carbon black, and a foaming agent is loaded into a packaging container, physical shock from the outside can be alleviated, and the display panel caused by static electricity can be alleviated. Technology regarding anti-static foam that can prevent defects has been announced, and Korean Patent No. 10-0855053 uses latex as the main material to form a large number of fine bubbles, breaking down the characteristics of a typical non-conductor in latex foam. And technology regarding conductive latex foam that has electrical conductivity and can be used as parts of electronic products and its manufacturing method has been announced.

In addition, Korea Patent No. 10-2142116 discloses a technology related to a foam composition containing conductive carbon black with improved antistatic properties that can exhibit permanent antistatic performance by incorporating surface-modified conductive carbon black into the foam. It has been announced.

However, although carbon black, which was used as a conductive additive in conventional patents, has the characteristic of excellent surface resistance as is well known, there are limitations in producing foams of various colors due to the inherent color of carbon black. It has the disadvantage of causing dust generation during the process.

Therefore, there is a need to develop technology that provides electrical conductivity to the polymer substrate applied to the foam and enables color expression at the same time.

Republic of Korea Patent Publication No. 10-2008-0097007 (2008.11.04.) Republic of Korea Patent No. 10-0855053 (2008.08.22.) Republic of Korea Patent No. 10-2142116 (2020.07.31.)

The present invention was developed to solve the above-mentioned problems. The purpose of the present invention is to provide a conductive foam composition that has excellent anti-static performance, transparency, and color expression that can provide various colors in finished products.

The objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above object, in the conductive foam composition capable of developing color according to the present invention, 20 to 40 parts by weight of an antistatic agent based on 100 parts by weight of ethylene vinyl acetate copolymer (EVA); 5 to 10 parts by weight of metal oxide; 1 to 2 parts by weight of stearic acid; 10 to 20 parts by weight of hard coal; 1 to 2 parts by weight of hardener; 5 to 15 parts by weight of foaming agent; and 50 to 70 parts by weight of polar rubber.

At this time, the polar rubber is characterized as acrylonitrile butadiene rubber (NBR), and the antistatic agent is bis(2-chloroethyl)ether-1,3-bis[3-(dimethylamino)propyl] urea. It is characterized in that it is one or more selected from copolymers, quaternary ammonium compounds, glycerin compounds, polypropylene glycol, and polyethylene glycol.

Meanwhile, the curing agent is characterized as t-butylperoxyisopropylbenzene (BIPB), and the blowing agent is an azo-based compound such as azobisisobutyronitrile, dimethyl 1,1'-azobis(1-cyclo It is characterized in that it is one or more selected from hexanecarboxylate) and azodicarbonamide.

At this time, the foam composition includes a masterbatch manufacturing step (S10) of preparing a masterbatch by mixing 100 parts by weight of the ethylene vinyl acetate copolymer (EVA) and 20 to 40 parts by weight of the antistatic agent, and adding the polarity to the masterbatch. A foam composition containing 50 to 70 parts by weight of rubber, 5 to 10 parts by weight of the metal oxide, 1 to 2 parts by weight of stearic acid, 10 to 20 parts by weight of the hardening agent, 1 to 2 parts by weight of the curing agent, and 5 to 15 parts by weight of the foaming agent. It is characterized in that it is manufactured through a manufacturing step (S20).

The conductive foam composition capable of developing color of the present invention has an advantage in that it has excellent antistatic properties by containing a transparent antistatic agent and can adsorb fine impurities in the air.

In addition, the conductive foam composition capable of expressing color of the present invention has the advantage of being transparent by including an antistatic agent having transparency, thereby providing a molded article with a desired color.

In addition, the conductive foam composition capable of expressing color of the present invention has the advantage of preventing dust from being generated in molded products by containing a transparent antistatic agent.

Figure 1 is a flowchart showing a method of manufacturing a conductive foam composition capable of expressing color according to the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

Specific details for implementing the present invention will be described in detail with reference to the drawings attached below. Regardless of the drawings, the same reference numerals refer to the same elements, and “and/or” includes each and all combinations of one or more of the mentioned items.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other elements in addition to the mentioned elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

First, the conductive foam composition capable of expressing color includes ethylene vinyl acetate copolymer (EVA), antistatic agent, metal oxide, stearic acid, carbon dioxide, curing agent, foaming agent, and polar rubber.

At this time, it is preferable to use acrylonitrile butadiene rubber (NBR) as the polar rubber. The acrylonitrile butadiene rubber (NBR) is a polymer obtained by copolymerizing butadiene and acrylonitrile, and the CN group, which is a polar group, is bonded to the other. It can exhibit higher conductivity compared to rubber.

According to a preferred embodiment, the polar rubber contains 50 to 70 parts by weight based on 100 parts by weight of the ethylene vinyl acetate copolymer (EVA), and according to a more preferred embodiment, the polar rubber contains the ethylene vinyl acetate copolymer (EVA). EVA) contains 60 parts by weight per 100 parts by weight.

Meanwhile, the antistatic agent is used to provide an antistatic function to the conductive foam composition capable of expressing color, and is a bis(2-chloroethyl)ether-1,3-bis[3-(dimethylamino)propyl] urea copolymer. , quaternary ammonium compounds, glycerin compounds, polypropylene glycol, and polyethylene glycol are preferably used.

The antistatic agent preferably contains 20 to 40 parts by weight based on 100 parts by weight of the ethylene vinyl acetate copolymer (EVA). When the antistatic agent is included in an amount of less than 20 parts by weight, the conductive foam composition capable of expressing color is It is difficult to achieve sufficient surface resistance, and if it exceeds 40 parts by weight, the viscosity of the conductive foam composition capable of expressing color increases, making foaming difficult, and there is a risk that the physical properties of the composition may deteriorate.

According to a more preferred embodiment, the antistatic agent contains 30 parts by weight based on 100 parts by weight of the ethylene vinyl acetate copolymer (EVA).

In addition, the bis(2-chloroethyl)ether-1,3-bis[3-(dimethylamino)propyl]urea copolymer, the quaternary ammonium compound, the glycerin compound, the polypropylene glycol, and the polyethylene glycol It has excellent antistatic properties and durability, and unlike carbon black, which is widely used as the most representative conductive additive, it is transparent and can be produced in a variety of colors when commercialized.

Next, the metal oxide is added to improve the electrical conductivity of the conductive foam composition capable of developing color, and is preferably contained in an amount of 5 to 10 parts by weight based on 100 parts by weight of the ethylene vinyl acetate copolymer (EVA). If it exceeds 10 parts by weight, there is a risk that the transparency and dispersibility of the conductive foam composition capable of expressing color may decrease.

In addition, the metal oxide contained in the conductive foam composition capable of expressing color is at least one selected from zinc oxide, ammonium oxide, tin oxide, and titanium dioxide.

Next, the stearic acid is used as a dispersion lubricant and is added for the purpose of maximizing dispersibility when manufacturing the conductive foam composition capable of expressing color, and the stearic acid is added to 100 parts by weight of the ethylene vinyl acetate copolymer (EVA). It is preferable to include 1 to 2 parts by weight, and more preferably 1.5 parts by weight.

Meanwhile, the light is a filler included to improve the strength and processability of products manufactured from the conductive foam composition capable of expressing color, and according to a preferred embodiment, it is contained in 100 parts by weight of the ethylene vinyl acetate copolymer (EVA). , 10 to 20 parts by weight, and according to a more preferred embodiment, 15 parts by weight.

At this time, the average particle size of the hard carbon is preferably 10 to 20 μm, and if the average particle size of the hard carbon exceeds 20 μm, the physical properties of the product manufactured from the conductive foam composition capable of expressing color may deteriorate.

In addition, as fillers included in the conductive foam composition capable of developing color, calcium carbonate, magnesium carbonate, silica, clay, etc. may be used in addition to the hard carbon.

According to a preferred embodiment, the curing agent is t-butylperoxyisopropylbenzene (BIPB) and contains 1 to 2 parts by weight based on 100 parts by weight of the ethylene vinyl acetate copolymer (EVA). In a more preferred embodiment, the curing agent is t-butylperoxyisopropylbenzene (BIPB). Accordingly, it contains 1.5 parts by weight.

Next, the foaming agent is at least one selected from the azo-based compounds azobisisobutyronitrile, dimethyl 1,1'-azobis(1-cyclohexanecarboxylate), and azodicarbonamide, and is added to 100 weight of the EVA. Part by weight, it is preferable to include 5 to 15 parts by weight, and more preferably 10 parts by weight.

Figure 1 is a flowchart showing a method of manufacturing a conductive foam composition capable of expressing color according to the present invention.

As shown in FIG. 1, the conductive foam composition capable of expressing color is manufactured through a masterbatch manufacturing step (S10) and a foam composition manufacturing step (S20).

First, in the masterbatch manufacturing step (S10), a masterbatch is prepared by mixing 100 parts by weight of the ethylene vinyl acetate copolymer (EVA) and 20 to 40 parts by weight of the antistatic agent.

Thereafter, in the foam composition manufacturing step (S20), 50 to 70 parts by weight of the polar rubber, 5 to 10 parts by weight of the metal oxide, and 1 to 2 parts by weight of stearic acid are added to the masterbatch prepared in the masterbatch manufacturing step (S10). A foam composition is prepared by adding 10 to 20 parts by weight of the hard charcoal and 5 to 15 parts by weight of the foaming agent.

That is, the masterbatch is prepared by first mixing the ethylene vinyl acetate copolymer (EVA) and the antistatic agent as described above, and the polar rubber, the metal oxide, the stearic acid, the carbon dioxide, and the above are added to the prepared masterbatch. By kneading the foaming agent to prepare the foam composition, the dispersibility of the foam composition can be further maximized.

Hereinafter, the configuration and operation of the present invention will be described in more detail through examples, comparative examples, and experimental examples of the present invention. However, the following examples are intended to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. Any information not described here can be technically inferred by anyone skilled in the art, so description thereof will be omitted.

Example

A masterbatch was prepared by mixing 100kg of ethylene vinyl acetate copolymer (EVA) and 30kg of glycerin compound, and the masterbatch was supplemented with 60kg of acrylonitrile butadiene rubber (NBR), 7kg of zinc oxide, 1.5kg of stearic acid, 15kg of hard carbon, and t-butyl. A foam sheet was prepared by foaming a foam composition prepared by adding 1.5 kg of peroxyisopropylbenzene (BIPB) and 10 kg of azobisisobutyronitrile.

Thereafter, the foam sheet was molded for 7 minutes under the conditions of 170°C and 150 kg/cm ² to prepare a foam test piece.

Comparative Example 1

It was prepared in the same manner as in the above example, except for acrylonitrile butadiene rubber (NBR).

Comparative Example 2

It was prepared in the same manner as in the above example, but excluding zinc oxide.

Comparative Example 3

It was prepared in the same manner as in the above example, except that the glycerin compound was replaced with carbon black.

That is, the foam composition according to the present invention was mixed with the components shown in Table 1 below, and the foam compositions of Examples and Comparative Examples 1 to 3 were foamed to prepare a foam sheet and then molded to prepare a foam test piece.

division Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Ethylene vinyl acetate copolymer 100 100 100 100 Glycerin compound 30 30 30 - zinc oxide 7 7 - 7 stearic acid 1.5 1.5 1.5 1.5 wonderment 15 15 15 15 t-butylperoxyisopropylbenzene 1.5 1.5 1.5 1.5 Azobisisobutyronitrile 10 10 10 10 Acrylonitrile butadiene rubber 60 - 60 60 carbon black - - - 30

Experiment example

This experimental example was an experiment to check the surface resistance, tensile strength, color, and dust generation of foam test pieces manufactured using the foam compositions of Examples and Comparative Examples 1 to 3, and the results are shown in Table 2.

At this time, the surface resistance was measured using a surface electrical resistance meter (Model 800) from ACSL Staticide, a device that measures the electrical resistance on the surface of a foam test piece in accordance with ASTM D257, and the average value was recorded after measuring 10 times.

In addition, the tensile strength was measured using a universal testing machine from Zwick in accordance with KS M6518, and the color was visually confirmed and then indicated.

Additionally, the generation of dust was checked after cleaning in an ultrasonic cleaner for 10 minutes.

division Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Surface resistance (Ω/sq.) 10 ⁶ 10 ⁶ 10 ¹⁵ 10 ⁶ Tensile strength (kg/cm ² ) 20 18 14.5 19.2 color Transparency Transparency Transparency black Whether dust is generated doesn't exist doesn't exist generation doesn't exist

As can be seen in Table 2, ethylene vinyl acetate copolymer (EVA), glycerin compound, zinc oxide, stearic acid, carbon dioxide, t-butylperoxyisopropylbenzene (BIPB), azobisisobutyronitrile, and acrylonitrile butadiene rubber. It was confirmed that the foam test piece (Example 1) made from a foam composition containing (NBR) was superior to the foam test pieces of Comparative Examples 1 to 3 in antistatic properties, tensile strength, and transparency, and did not generate dust. You can.

Although embodiments of the present invention have been described with reference to the above and the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will understand that it exists. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

S10: Masterbatch manufacturing stage
S20: Foam composition manufacturing step

Claims (6)

In a conductive foam composition capable of expressing color,
For 100 parts by weight of ethylene vinyl acetate copolymer (EVA),
20 to 40 parts by weight of antistatic agent;
5 to 10 parts by weight of metal oxide;
1 to 2 parts by weight of stearic acid;
10 to 20 parts by weight of hard coal;
1 to 2 parts by weight of hardener;
5 to 15 parts by weight of foaming agent; and
A conductive foam composition capable of expressing color, comprising 50 to 70 parts by weight of polar rubber. According to paragraph 1,
The polar rubber is,
A conductive foam composition capable of expressing color, characterized in that it is acrylonitrile butadiene rubber (NBR). According to paragraph 1,
The antistatic agent,
Bis(2-chloroethyl)ether-1,3-bis[3-(dimethylamino)propyl] urea copolymer, quaternary ammonium compound, glycerin compound, polypropylene glycol, and polyethylene glycol. A conductive foam composition capable of expressing color. According to paragraph 1,
The hardener is,
A conductive foam composition capable of expressing color, characterized in that it is t-butylperoxyisopropylbenzene (BIPB). According to paragraph 1,
The foaming agent,
A conductive foam composition capable of expressing color, characterized in that it is one or more selected from the azo-based compounds azobisisobutyronitrile, dimethyl 1,1'-azobis(1-cyclohexanecarboxylate), and azodicarbonamide. According to paragraph 1,
The foam composition is,
A masterbatch manufacturing step (S10) of preparing a masterbatch by mixing 100 parts by weight of the ethylene vinyl acetate copolymer (EVA) and 20 to 40 parts by weight of the antistatic agent, 50 to 70 parts by weight of the polar rubber to the masterbatch, Through the foam composition manufacturing step (S20) of adding 5 to 10 parts by weight of the metal oxide, 1 to 2 parts by weight of stearic acid, 10 to 20 parts by weight of the hardening agent, 1 to 2 parts by weight of the curing agent, and 5 to 15 parts by weight of the foaming agent. A conductive foam composition capable of expressing color, characterized in that it is manufactured.