WO2013032059A1

WO2013032059A1 - Conductive composition and method for preparing same

Info

Publication number: WO2013032059A1
Application number: PCT/KR2011/007547
Authority: WO
Inventors: 진용현; 정경원; 송순모; 이재준
Original assignee: (주)누리비스타
Priority date: 2011-08-26
Filing date: 2011-10-11
Publication date: 2013-03-07
Also published as: KR20130022982A; KR101289768B1; CN103764766A

Abstract

The present invention relates to a conductive polymer composition and to a method for preparing same, and more particularly, to a conductive composition and to a method for preparing same, wherein the conductive composition has superior electrical conductivity and stability due to increased crosslink density of poly(3,4-ethylenedioxythiphene) through the addition of polycellulose sulfonate as a dopant into poly(3,4-ethylenedioxythiphene).

Description

Conductive composition and method for preparing same

The present invention relates to a conductive polymer composition and a method for preparing the same, and more particularly, to poly (3,4-ethylenedioxythiophene) by adding polycellulose sulfonate as a dopant to poly (3,4-ethylenedioxythiophene). The present invention relates to a conductive composition having high electrical crosslinking density and excellent stability and a method for producing the same.

The conductive polymer is an organic material and has the advantage of passing electricity, so the usefulness of the conductive polymer is very diverse. Recently, conductive polymers are applied in real life and high-tech industries such as touch panels, flexible display devices, flexible solar transparent electrodes, electronic notebooks, secondary batteries, antistatic, switching devices, nonlinear devices, capacitors, optical recording materials, and electromagnetic shielding materials. It is becoming.

In order for the conductive polymer to have conductivity, a doping process is required. Typically, after the powder form or film form, they are chemically doped, or by mixing the conductive powder and the dopant is dissolved by an organic solvent to make a conductive method.

Among various conductive polymers, poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate) (PEDOT / PSS) is stable in the air, and has high electrical conductivity at room temperature compared to other polymers, and has been applied in various fields.

Particularly, samples doped with poly (3,4-ethylenedioxythiophene) and doped with poly (4-styrenesulfonate) (PSS) with dopants have very uniform coatings with electrodes or antistatic materials, and have excellent interfacial properties and adhesion. Excellent application, wide application.

Current research on poly (3,4-ethylenedioxythiophene), like other polymers, is mostly about electrical and chemical synthesis using various dopants and its application.

The present invention is to replace the poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate), and more particularly relates to a novel conductive polymer composition and a method for producing the same by replacing the dopant with another material. .

An object of the present invention is to increase the crosslinking density of poly (3,4-ethylenedioxythiophene) by adding polycellulose sulfonate as a dopant to poly (3,4-ethylenedioxythiophene), and have excellent electrical conductivity and stability. It is to provide a composition and a method for producing the same.

The conductive composition of the present invention for achieving the above object is (a) a random copolymer having a unit structure represented by the following formula (1) doped with a polycellulose sulfonate doped with a polycellulose sulfonate having at least one sulfonate group in the copolymer and ( b) characterized by comprising a solvent.

[Formula 1]

Wherein R is —H, — (CH ₂ CH ₂ ) —OH, —CH ₂ CH ₂ OCH ₂ CH (OH) CH ₂ SO ₃ H, —CH ₂ CH ₂ OCH ₂ CH (OH) CH ₂ O -mC ₁₈ H ₃₇ one selected from m, at least one.

Method for producing a conductive composition of the present invention for achieving the above object (A) preparing a conductive polymer monomer solution containing a conductive polymer monomer, polycellulose sulfonate and a solvent and (B) polymerizing the conductive polymer monomer solution Characterized in that it comprises a step.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a conductive composition and a method of manufacturing the same according to the present invention will be described in detail.

Conductive Polymer Composition

The conductive polymer composition according to the present invention comprises (a) a random copolymer having a unit structure represented by the following Chemical Formula 1, and a conductive polymer doped with a polycellulose sulfonate having at least one sulfonate group in the copolymer, and (b) a solvent. It is characterized by including.

[Formula 1]

In the present invention, by using a polycellulose sulfonate as a dopant, the crosslinking density of the conductive polymer is increased, and electrical conductivity and thermal stability are improved. Hereinafter, the components of the conductive polymer composition of the present invention will be described in detail.

First, the conductive polymer of the present invention is an electrically conductive polymer having one? Electron per carbon atom, and generally has a molecular weight of about 3,000 or more. The conductive polymer has the advantage of being able to obtain a thin film having a high weight and flexibility compared to ITO, which is generally used as a transparent electrode.

Dopant refers to a material that acts as a charge carrier by adding or removing charges to a part of the π orbital function of the conductive polymer of the present invention. Dopants are generally added to give conductivity to the conductive polymer. The doping is added to the conductive polymer to form a charge carrier. Specifically, when providing charge to the conductive polymer is called doping (n-type doping), when removing the charge from the conductive polymer is called p-type doping (p-type doping).

According to the present invention, the electrical conductivity of the conductive polymer composition is increased and the thermal stability is increased by doping the conductive polymer using polycellulose sulfonate. At this time, the polycellulose sulfonate used as the dopant is a random copolymer having a unit structure represented by the following formula (1), and has at least one sulfonate group in the copolymer.

[Formula 1]

Specific structure of the polycellulose sulfonate represented by the formula (1) is the same as the formula (1-1).

[Formula 1-1]

When the polycellulose sulfonate of Chemical Formula 1 (or Chemical Formula 1-1) is dissolved in water, Na + ions dissociate as in Scheme 1 below, and H + ions are covalently bonded to sulfonate groups to form sulfonic acid groups.

Scheme 1

Hereinafter, the principle of improving the electrical conductivity and the thermal stability according to the polycellulose sulfonate doping of the conductive polymer will be described in detail.

As shown in Scheme 2, when the conductive polymer monomer ethylenedioxythiophene (EDOT) is oxidized, the cation of poly (3,4-ethylenedioxythiophene) and the sulfonate group anion of polycellulose sulfonate are electrically Guided together by gravity, they form a long chain.

Scheme 2

At this time, since the polycellulose sulfonate contains a hydroxyl group (-OH), hydrogen bonding occurs between the polycellulose sulfonate molecules, thereby increasing the crosslinking density of the conductive polymer chain.

Accordingly, the distance between the poly (3,4-ethylenedioxythiophene) conductive polymers is shortened, and the electrical conductivity of the conductive polymer composition is improved.

In addition, since the crosslinking density between the conductive polymer chains is high, the stability of the molecular structure is increased, and thus, even when heat is applied, the deformation of the polymer chains is small, thereby maintaining electrical properties. Such effects occur not only in the above-mentioned poly (3,4-ethylenedioxythiophene) conductive polymer but also in other conductive polymers.

Here, the conductive polymer doped with the polycellulose sulfonate of the present invention may be any of polythiophene-based, polypyrrole-based, polynetylene-based, polyaniline-based or polyacetylene-based.

In this case, the polythiophene-based conductive polymer is preferably poly (3,4-ethylenedioxythiophene). Poly (3,4-ethylenedioxythiophene) / polycellulose sulfonate has the advantages of high electrical conductivity, excellent thermal stability, and good transparency.

With respect to 100 parts by weight of the conductive composition of the present invention, the content of the conductive polymer doped with polycellulose sulfonate is preferably 0.1 to 50 parts by weight, more preferably 0.1 to 20 parts by weight. When the content of the conductive polymer doped with polycellulose sulfonate is less than 0.1 part by weight, it is difficult to realize high conductivity of 1 dB / □ or less even when a large amount of polar solvent is used as an additional dopant, and when it exceeds 50 parts by weight, the long wavelength of visible light If the area (550 nm) or more, the transmittance is reduced, there is a problem that the coating workability is not easy.

Next, a solvent included in the conductive composition of the present invention is added to disperse the conductive polymer in the solution phase. The solvent of the present invention may be at least one selected from water, aliphatic alcohols, aliphatic ketones, aliphatic carboxylic acid esters, aliphatic carboxylic acid amides, aromatic hydrocarbons, aliphatic hydrocarbons, acetonitrile, aliphatic sulfoxides, sorbitol.

At this time, the content of the solvent of the present invention is preferably 50 to 99.9 parts by weight, more preferably 60 to 99 parts by weight based on 100 parts by weight of the conductive composition. The solvent of the present invention is added to disperse the conductive polymer on the solution. When the content of the solvent is less than 50 parts by weight, the dispersibility of the conductive polymer is inferior, which may cause a problem of resistance scattering. When the amount is exceeded, there is a problem that the electrical conductivity of the conductive polymer composition is reduced.

The conductive polymer composition according to the present invention may further include a second dopant. The second dopant exhibits a screen effect between the conductive polymer and the polycellulose sulfonate to separate the polycellulose sulfonate having a low electrical conductivity from the conductive polymer, thereby improving the electrical conductivity of the conductive polymer composition as a whole.

The second dopant is only referred to as a secondary dopant because it causes a structural change of the conductive polymer and does not remain as a dopant, but exhibits the same effect as doping.

The second dopant is preferably an organic compound containing oxygen and nitrogen, and specifically, may be an ether group compound, a carbonyl group compound, a polar solvent, or a mixture thereof.

As the compound containing the ether group, diethylene glycol monoethyl ether and the like are preferable, and as the compound containing the carbonyl group, isoprone, propylene carbonate, cyclohexanone or butyrolactone is preferable. As the polar solvent, at least one selected from dimethyl sulfoxide, N-methylpyrrolidone, N, N-dimethylformamide, N-dimethylacetimide and sorbitol is preferable.

Among them, at least one selected from dimethyl sulfoxide, N-methylpyrrolidone, N, N-dimethylformamide, N-dimethylacetimide and sorbitol as the second dopant in terms of electrical conductivity improvement is used. desirable.

The content of the second dopant is preferably 0.5 to 15 parts by weight, and more preferably 0.5 to 5 parts by weight based on 100 parts by weight of the conductive polymer composition of the present invention. If the content of the second dopant is less than 0.5 parts by weight, there is little effect of improving the electrical conductivity, and if it exceeds 10 parts by weight, it is uneconomical because there is no effect of improving the conductivity due to the addition.

Meanwhile, the conductive composition of the present invention may further include a binder. The binder increases adhesion when the conductive polymer composition is applied to the base member. The binder may be at least one selected from acrylic, epoxy, ester, cellulose, urethane, ether, carboxyl, and amide based.

At this time, the content of the binder is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight with respect to 100 parts by weight of the conductive composition of the present invention. When the content of the binder is less than 0.1 parts by weight, the effect of improving adhesion is insignificant, and when the content of the binder is more than 10 parts by weight, the content is relatively higher than that of the conductive polymer, thereby reducing the electrical conductivity.

The conductive polymer composition according to the present invention may further include other additives such as dispersion stabilizers and surfactants in addition to the above additives.

Method for producing a conductive composition

The method for preparing a conductive composition of the present invention includes the steps of preparing a conductive polymer monomer solution comprising (A) a conductive polymer monomer, a polycellulose sulfonate and a solvent, and (B) polymerizing the conductive polymer monomer solution. It features. In the present invention, in polymerizing a conductive polymer, by using a polycellulose sulfonate as a dopant to dope the conductive polymer, the electrical conductivity and thermal stability of the conductive polymer composition is improved.

Hereinafter, the manufacturing process of the conductive composition of the present invention will be described. The overlapping parts will be omitted or briefly mentioned.

First, (A) A conductive polymer monomer solution containing a conductive polymer monomer, a polycellulose sulfonate and a solvent is prepared.

Here, the conductive polymer monomer may be thiophene, aniline, pyrrole, acetylene, phenylene or derivatives thereof.

In this case, preferably, the conductive polymer monomer may be 3,4-ethylenedioxythiophene. Poly (3,4-ethylenedioxythiophene) polymerized with the conductive polymer monomer 3,4-ethylenedioxythiophene has the advantage of high electrical conductivity and excellent transmittance.

At this time, the content of the conductive polymer monomer is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 3 parts by weight of 100 parts by weight of the conductive polymer monomer solution. If the content of the conductive polymer monomer is less than 0.1 parts by weight, there is a problem that the electrical conductivity of the conductive polymer composition is low, if it exceeds 20 parts by weight, the transmittance of the conductive polymer composition is lowered, the problem is not easy processing There is.

The conductive polymer monomer solution of the present invention includes a polycellulose sulfonate as a dopant, and the present invention enables the production of a conductive polymer doped with polycellulose sulfonate by using the polycellulose sulfonate as a dopant in the polymerization of the conductive polymer monomer. do. The conductive polymer composition of the present invention doped with polycellulose sulfonate has excellent electrical conductivity with a sheet resistance of 500 Ω / □ or less, and has high stability due to less change in molecular structure due to heat.

At this time, the content of the polycellulose sulfonate is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 6 parts by weight of 100 parts by weight of the conductive polymer monomer solution. When the content of the polycellulose sulfonate is less than 0.01 part by weight, the solubility of the conductive polymer is lowered and the doping effect of the conductive polymer is low. When the content of the polycellulose sulfonate is more than 10 parts by weight, the electrical conductivity improvement effect is increased by the addition of the polycellulose sulfonate. Insignificant

As described above, the solvent of the present invention serves to dissolve and disperse the conductive polymer monomer and the polycellulose sulfonate. The solvent includes 40 to 99 parts by weight of 100 parts by weight of the conductive polymer monomer solution.

Next, (B) the conductive polymer monomer solution is polymerized. By polymerizing the conductive polymer monomer solution, a conductive polymer doped with polycellulose sulfonate can be obtained.

Chemical polymerization, electrochemical polymerization, thermal polymerization, photopolymerization, and the like may be used as a method of polymerizing the conductive polymer monomer solution. In the present invention, it is preferable to use oxidative polymerization during chemical polymerization. Oxidation polymerization can be polymerized at low cost and has the advantage of a simple polymerization method.

Specifically, oxidizing agents such as ammonium peroxydisulfate, hydrochloric acid, and Lewis acid are added to the conductive polymer monomer solution to easily oxidize the monomer, and then polymerize to the conductive polymer. At this time, the oxidizing agent is preferably added 0.0001 ~ 4 mol relative to 1 mol of the conductive polymer monomer.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited by this embodiment.

Example 1

Water, 3,4-ethylenedioxythiophene, polycellulose sulfonate was added to a round 100 ml reaction vessel, and stirred and sonicated for 30 minutes to prepare a conductive polymer monomer solution. At this time, the composition ratio of the conductive polymer monomer solution was 97 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 2 parts by weight of polycellulose sulfonate based on 100 parts by weight of the conductive polymer monomer solution.

Next, 14.08 mmol of the oxidizing agent Fe ₂ (SO ₄ ) ₃ 5H ₂ O was added to the conductive polymer monomer solution, followed by oxidative polymerization at 25 ° C. for 3 hours to give poly (3,4-ethylenedioxythiophene) / poly Cellulosesulfonate (PEDOT / PCS) conductive polymer compositions were prepared. The conductive polymer composition was coated on a base member and dried in an oven at 100 ° C. for 2 minutes to prepare a conductive film.

Example 2

In the same manner as in Example 1, the composition ratio of the conductive polymer monomer solution is different from 96.5 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 2.5 parts by weight of polycellulose sulfonate based on 100 parts by weight of the conductive polymer monomer solution. It was.

The conductive polymer composition was coated on the base member and dried in an oven at 100 ° C. for 2 minutes to prepare a conductive film.

Example 3

In the same manner as in Example 1, the composition ratio of the conductive polymer monomer solution is different from 94 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 5 parts by weight of polycellulose sulfonate based on 100 parts by weight of the conductive polymer monomer solution. It was.

Example 4

In the same manner as in Example 1, the composition ratio of the conductive polymer monomer solution is different from 93 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 6 parts by weight of polycellulose sulfonate based on 100 parts by weight of the conductive polymer monomer solution. It was.

Comparative Example 1

In the same manner as in Example 1, polystyrene sulfonate was added instead of polycellulose sulfonate as a dopant. The composition ratio of the conductive polymer monomer solution was 96.5 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 2.5 parts by weight of polystyrenesulfonate based on 100 parts by weight of the conductive polymer monomer solution.

Comparative Example 2

In the same manner as in Example 1, polystyrene sulfonate was added instead of polycellulose sulfonate as a dopant. The composition ratio of the conductive polymer monomer solution was 97 parts by weight of water, 1 part by weight of 3,4-ethylenedioxythiophene, and 6 parts by weight of polystyrenesulfonate based on 100 parts by weight of the conductive polymer monomer solution.

Test Example

The sheet resistance of the conductive films prepared from the conductive polymer compositions of Examples and Comparative Examples before and after the heat treatment was evaluated and shown in Table 1 below. For sheet resistance, Mitsubishi Chemical Corporation's Loresta EP MCP-T360 was used. Heat treatment was performed for 30 minutes in 150 degreeC oven.

Table 1

	Before heat treatment		After heat treatment
	Sheet resistance (Ω / □)	Scatter%	Sheet resistance (Ω / □)	Scatter%
Example 1	157.0	6.4	163.8	12.2
Example 2	181.0	7.9	199.1	12.6
Example 3	195.3	7.5	211.4	12.5
Example 4	238.5	8.1	251.3	12.8
Comparative Example 1	212.8	15.0	224.0	33.5
Comparative Example 2	265.2	15.5	278.8	33.7

As can be seen from the experimental data of Table 1, the conductive polymer poly (3,4-ethylenedioxythiophene) / polycellulose sulfonate (PEDOT / PCS) doped with polycellulose sulfonate is poly (3,4- It was found that the lower the sheet resistance value than ethylenedioxythiophene) / polystyrene sulfonate (PEDOT / PSS), the better the electrical conductivity. In addition, it was confirmed that the conductive polymer poly (3,4-ethylenedioxythiophene) / polycellulose sulfonate of the present invention had low dispersion (%) of sheet resistance values before and after heat treatment, and thus had excellent thermal stability.

Although the present invention has been described in detail through specific examples, it is intended to describe the present invention in detail, and the conductive polymer composition and its preparation method according to the present invention are not limited thereto, and the present invention is applicable within the spirit of the present invention. It will be apparent that modifications and improvements are possible by those skilled in the art. All modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the following claims.

According to the present invention, by doping a conductive polymer using a polycellulose sulfonate as a dopant, the crosslinking density between the conductive polymers is increased, thereby improving the electrical conductivity.

In addition, according to the present invention, by doping the conductive polymer using a polycellulose sulfonate as a dopant, the stability of the molecular structure of the entire composition is increased, there is an effect that the width of change in electrical conductivity due to heat is reduced.

Claims

(a) a conductive polymer doped with a polycellulose sulfonate having at least one sulfonate group in the copolymer in a random copolymer having a unit structure represented by Formula 1 below; And

(b) a solvent;

A conductive polymer composition comprising a.

[Formula 1]

Wherein R is -H,-(CH 2 CH 2 ) -OH, -CH 2 CH 2 OCH 2 CH (OH) CH 2 SO 3 H, -CH 2 CH 2 OCH 2 CH (OH) CH 2 O-mC 18 H 37 is selected, m is 1 or more.)
The method of claim 1,

The conductive polymer composition, characterized in that the conductive polymer doped with the polycellulose sulfonate is 0.1 to 50 parts by weight, and the solvent is 50 to 99.9 parts by weight based on 100 parts by weight of the conductive polymer composition.
The method of claim 1,

The conductive polymer doped with the polycellulose sulfonate is a conductive polymer composition, characterized in that any one of a polythiophene-based, polypyrrole-based, polyphenylene-based, polyanilene-based or polyacetylene-based conductive polymer.
The method of claim 3,

The polythiophene-based conductive polymer is poly (3,4-ethylenedioxythiophene) (PEDOT), characterized in that the conductive polymer composition.
The method of claim 1,

The solvent is a conductive polymer, characterized in that at least one mixture selected from water, aliphatic alcohol, aliphatic ketone, aliphatic carboxylic acid ester, aliphatic carboxylic acid amide, aromatic hydrocarbon, aliphatic hydrocarbon, acetonitrile and aliphatic sulfoxide, sorbitol Composition.
The method of claim 1,

The conductive polymer composition further comprises a second dopant.
The method of claim 1,

The second dopant is a conductive polymer composition, characterized in that at least one mixture selected from dimethyl sulfoxide, N-methylpyrrolidone, N, N-dimethylformamide and N-dimethylacetimide, sorbitol.
The method of claim 1,

The conductive polymer composition further comprises a binder.
The method of claim 8,

The binder is a conductive polymer composition, characterized in that at least one mixture selected from acrylic, epoxy, ester, cellulose, urethane, ether, carboxyl and amide binder.
(A) preparing a conductive polymer monomer solution comprising a conductive polymer monomer, a polycellulose sulfonate and a solvent; And

(B) polymerizing the conductive polymer monomer solution;

Method for producing a conductive polymer composition comprising a.
The method of claim 10,

The polymerization method of producing a conductive polymer composition, characterized in that by the oxidation polymerization using an oxidizing agent.
The method of claim 10,

The conductive polymer composition is 0.1 to 20 parts by weight, the polycellulose sulfonate is 0.01 to 10 parts by weight, and the solvent is 50 to 99 parts by weight based on 100 parts by weight of the conductive polymer monomer solution. Manufacturing method.
The method of claim 10,

The conductive polymer monomer is a method for producing a conductive polymer composition, characterized in that the conductive polymer monomer selected from the group consisting of thiophene, aniline, pyrrole, acetylene, phenylene and derivatives thereof.
The method of claim 10,

The conductive polymer monomer is a method for producing a conductive polymer composition, characterized in that 3,4-ethylenedioxythiophene.
The method of claim 10,

The solvent is a conductive polymer, characterized in that at least one mixture selected from water, aliphatic alcohol, aliphatic ketone, aliphatic carboxylic acid ester, aliphatic carboxylic acid amide, aromatic hydrocarbon, aliphatic hydrocarbon, acetonitrile and aliphatic sulfoxide, sorbitol Method of Preparation of the Composition.