KR20080111944A - Conducting polymer coating composition having excellent mechanical properties by using multi-functional silicone precursor - Google Patents

Abstract

A conductive polymer coating composition having excellent solvent resistance by using multi-functional silicone precursor is provided to ensure solvent resistance, thin film hardness, adhesive property, transparency and conductivity. A conductive polymer coating composition comprises conductive polymer solution 10~90 weight% consisting of a conductive polymer, oxidizer, dopant and solvent; and multifunctional silicon precursor 90~10 weight%. The conductive polymer coating composition has the conductivity less than 105 Ф / sq and transparency of 80%, shows excellent anti-organic solvent resistance and film hardness of 4H or more.

Description

Conducting polymer coating composition having excellent mechanical properties by using multi-functional silicone precursor

The present invention relates to a polymer coating composition having excellent solvent resistance and mechanical strength and having transparency and conductivity, and a method of manufacturing the same. More specifically, the present invention relates to a polymer coating composition having excellent transparency and conductivity while having excellent solvent resistance and mechanical strength prepared by mixing a conductive polymer compound well dispersed in a solvent with a silane precursor having a multifunctional group.

Conventionally, as known in US Pat. No. 6,322,860 as a thin film having conductivity and transparency, indium tin oxide (ITO) sputtered on a substrate has been studied a lot. However, the ITO thin film requires an expensive vacuum process, and it is difficult to use the substrate as a plastic when heat-treated at a high temperature in order to lower the resistance. Other methods of manufacturing thin films with conductivity and transparency include chemical vapor deposition using a variety of metal oxides and reactive evaporation deposition, but there are limitations that require expensive processing costs in order to coat metal oxides on substrates such as sputtering. Coating is difficult. On the other hand, in the case of thin film manufacturing using conductive polymers such as polyaniline, polypyrrol, polythiophene, and the like, dip coating, spray coating, spin coating, bar coating, etc. Various polymer coating methods can be used over a large area, thereby reducing the process cost and facilitating workability. There are potential applications of transparent electrodes, electromagnetic shielding materials, flexible electrodes, and antistatic materials by applying the electrical properties of these conductive polymers, but they are insoluble in various solvents and are difficult to process and have poor thermal stability. Meanwhile, as described in US Pat. Nos. 5,035,926 and 5,391,472, polyethylene dioxythiophene (PEDOT) is introduced, and the material has excellent electrical conductivity, transparency, and processability, thereby acknowledging many possibilities. do.

However, the weakness of applying PEDOT-based conductive polymer as a coating material is that the mechanical properties (hardness and scratch resistance) of the film formed after coating on various substrates are very weak, and the solvent resistance to various solvents is weak, making it easy to touch even a little. Peeling or melting have had a big problem in practical use. In order to solve such a problem, a polymer binder such as acrylic, polyurethane, and polystyrene having appropriate strength may be used in a mixture, but it is difficult to obtain a thin film having sufficient thermal stability and mechanical properties. Instead of such organic polymer binders, the introduction of a silicon-based inorganic material as a binder to prepare a thin film having sufficient mechanical strength is disclosed in Korean Patent Publication Nos. 10-0278347, Korean Patent Publication No. 10-0333191, and Korean Patent Publication No. 0442409 Known in However, when using silicon alkoxides such as tetraethoxyortho silicate (TEOS), methyltrimethoxy silane (MTMS), dimethyldimethoxysilane (DMDMS), which consist of one silicon atom, it is suitable prior to mixing with the conductive polymer solution. Under the reaction conditions, oligomer-type silicate sol obtained by sol-gel reaction with water and catalyst should be used. However, by simplifying the process, the silicon alkoxide composed of one silicon atom is directly mixed with the PEDOT-based conductive polymer solution to form a thin film on the substrate, and the coated thin film which is cured at low temperature (less than 100 degrees) is obtained from IPA (isopropyl alcohol) and Solvent resistance to the same solvent is very weak (delamination occurs less than 10 times during Rubbing), the surface hardness is also not more than 2H has a big problem for use in applications for practical use.

As a result of the research to solve the problems of the prior art, a variety of compositions obtained by simple mixing with a conductive polymer solution using a silicon alkoxide having a bridge-like, cyclic, cage-type multifunctional group consisting of two or more silicon atoms It was found that the thin film obtained by coating on the substrate and cured at low temperature has excellent solvent resistance, thin film hardness, adhesiveness, transparency and conductivity, and the present invention was completed based on this.

Accordingly, an object of the present invention is to provide a conductive polymer coating composition having excellent solvent resistance, thin film hardness, adhesiveness, transparency and conductivity in a simpler and more economical process (simple mixing, low temperature process) than the prior art.

Hereinafter, the present invention will be described in detail.

The present invention is a composition consisting of 10 to 90% by weight of a conductive polymer solution consisting of a conductive polymer, an oxidizing agent, a dopant and a solvent, and 90 to 10% by weight of a multifunctional silicon precursor, and then thinned it by a wet coating method. The conductivity of the thin film obtained by curing at low temperature is 10 ⁵ Ω / □ or less, has a transparency of 80% or more and a film hardness of 4H or more, and has transparency and conductivity that can withstand 50 times or more when rubbing in an organic solvent such as IPA. It is characterized by having a polymer hard coating composition having.

The conductive polymer used in the present invention includes a polymer compound having transparency and conductivity obtained from at least one monomer selected from the group consisting of aniline and aniline derivatives, blood and pyrrole derivatives or 3,4-ethylenedioxythiophene and derivatives thereof. Polyaniline, polypyrrole or polydioxyethylenethiophene.

As the oxidizing agent used in the present invention, at least one compound selected from the group consisting of iron chloride, ferric toluenesulfonate, ferricdodecylbenzene sulfonate, and ferric anthraquinonesulfonate has a monomer and molar ratio of 1: 1 to 1: Can be used in the range of 10.

As the dopant of the conductive polymers used in the present invention, organic compounds substituted with sulfonic acid groups are preferable, and examples thereof include para-toluene sulfonic acid, dodecyl benzene sulfonic acid, anthraquinone sulfonic acid, 4-hydroxy benzene sulfonic acid, methyl sulfonic acid and nitrobenzene. At least one compound selected from the group consisting of sulfonic acid, polystyrenesulfonate, poly (styrene-co-styrenesulfonic acid), poly (2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylonitrile) The monomer and molar ratio of the conductive polymer may be used in the range of 1: 1 to 1:10.

The solvent in the present invention is water or alcohol having 1 to 5 carbon atoms or formamide, such as methanol, ethanol, propanol, isopropanol, normal butanol, sec-butanol, tert-butanol, N-methylformamide, N, N-dimethylform At least one solvent or mixed solvent selected from the group consisting of an amide solvent such as amide or a sulfoxide solvent such as methyl sulfoxide or dimethyl sulfoxide may be used in the range of 1:30 to 1: 200 based on the conductive polymer monomer. Can be.

In the present invention, the polyfunctional silicon precursor used for the purpose of increasing the solvent resistance and mechanical properties (hardness, adhesiveness) of the coating film is a bridge type represented by the following formula (1), a cyclic type represented by the formula (2) , At least one silicone compound selected from the group consisting of cage-type precursors represented by formula (3) can be used. The silicon precursor of the bridge structure may be represented by the following Chemical Formula 1, a bridge structure in which silicon atoms are bonded through a R ′ group, and an organic group is formed at a terminal thereof to form a hydrolyzable substituent.

Formula 1

Wherein R 'is phenylene and phenylene derivatives, thiophene and thiophene derivatives, 3,4-ethylenedioxythiophene and derivatives thereof or acetylene and derivatives thereof, X1, X2 and X3 are independently C1 to C3 alkyl group , A C1-C10 alkoxy group, or a halogen atom.

The cyclic silicon precursor may be represented by the following Chemical Formula 2, which is a cyclic structure in which silicon atoms are bonded through an oxygen atom, and an organic group is formed at a terminal thereof to form a hydrolyzable substituent.

Formula 2

Wherein R is a hydrogen atom, a C1-C3 alkyl group, a C3-C10 cycloalky group or a C6-C15 allyl group, X1, X2, X3 are independently C1-C3 Is an alkyl group, a C1-C10 alkoxy group, or a halogen atom, p is an integer of 3-8, and m is an integer of 1-10. The manufacturing method of the cyclic silicon precursor is not particularly limited, but may be prepared through a hydrosilylation reaction using a metal catalyst.

The cage-type silicon precursor is represented by the following Chemical Formula 3, and is a cage-type structure in which silicon atoms are bonded through an oxygen atom, and the terminal includes an organic group forming a substituent capable of hydrolysis.

Formula 3

In the above formula, X1, X2, X3 are independently an alkyl group of C1-C3, an alkoxy group of C1-C10 or a halogen atom, n is an integer of 1-10. The method for preparing the cage-type siloxane monomer is not particularly limited, but may be prepared through a hydrosilylation reaction using a metal catalyst.

The method of coating the conductive polymer solution and the multifunctional silicon precursor mixture obtained in the present invention forms a thin film having a thickness of 0.1 to 5 micrometers through processes such as dip coating, spray coating, spin coating, and bar coating, which are well known in the art. do. In order to obtain sufficient solvent resistance and mechanical properties, the curing process is performed at a temperature below 100 ° C for 10 to 60 minutes, and the final thin film is obtained by washing the thin film with distilled water to remove residual oxidants and dopants. .

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Example 1. Synthesis of PEDOT-based Conductive Polymer

7.04 mmol (4.77 g) of ferrictoluenesulfonate was added to a round 100 ml reactor, n-butanol 80.949 mmol (6 g) was added thereto, and stirred for 1 hour. Then, 0.703 mmol (0.1 g) of 3.4-ethylenedioxythiophene, a conductive polymer monomer, was added thereto. Inject and stir for 24 hours.

Example 2. Synthesis of Silane Precursor A with Bridge Structure

       6.435 mmol (1.07 g) of 2,2-bithiophene was added to a round 100 ml reactor, and the mixture was placed in a nitrogen atmosphere. After 25ml of tetrahydrofuran was added and stirred, the reactor was cooled to 0 for 10 minutes, and 2.5M n-butyllithium 14 mmol (5.6ml) was slowly added thereto. After 5 minutes, slowly raise the temperature to room temperature and stir for 3 hours. After stirring for 3 hours, the round 100ml reactor was cooled to -78 for about 10 minutes, and 14 mmol (2.75ml) of triethoxychlorosilane was slowly added thereto. After 5 minutes, slowly raise the temperature to room temperature and stir for 20 hours. After stirring for 20 hours, the mixture was filtered through sea sand and celite, and then, tetrahydrofuran was removed by depressurizing, and 50 ml of hexane was added. The mixture was stirred for 1 hour, filtered through sea sand and celite, and filtered through hexane. By removing, a silane precursor of a viscous green liquid was synthesized.

Example 3 Synthesis of Silane Precursor B with Bridge Structure

6.415 mmol (0.912 g) of 3.4-ethylenedioxythiophene is added to a round 100 ml reactor, and the mixture is brought to a nitrogen atmosphere. After 25ml of tetrahydrofuran was added and stirred, the reactor was cooled to 0 for 10 minutes, and 2.5M n-butyllithium 14 mmol (5.6ml) was slowly added thereto. After 5 minutes, slowly raise the temperature to room temperature and stir for 3 hours. After stirring for 3 hours, the round 100ml reactor was cooled to -78 for about 10 minutes, and 14 mmol (2.75ml) of triethoxychlorosilane was slowly added thereto. After 5 minutes, slowly raise the temperature to room temperature and stir for 20 hours. After stirring for 20 hours, the mixture was filtered through sea sand and celite, and then, tetrahydrofuran was removed by depressurizing, and 50 ml of hexane was added. The mixture was stirred for 1 hour, filtered through sea sand and celite, and filtered through hexane. To remove, a silane precursor of viscous dark purple liquid was synthesized.

Example 4 Silicon Precursor C Synthesis of Cyclic Structure

2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane) 29.014 mmol (10.0 g) and platinum (0) -1,3-divinyl-1,1,3,3-tetramethyldisiloxane compound dissolved in xylene solution [platinum (0) -1,3-divinyl-1,1,3 0.164 g of, 3-tetramethyldisiloxane complex (solution in xylenes)) was weighed into a flask, and diluted with 300 ml of diethyl ether. After the reaction vessel was lowered to -78, trichlorosilane 127.66 mmol (17.29 g) was added slowly, and the reaction temperature was gradually raised to room temperature. Thereafter, the reaction was performed at room temperature for 20 hours, volatiles were removed under a reduced pressure of about 0.1 torr, 100 ml of pentane was added, and after stirring for 1 hour, the mixture was filtered through celite to obtain a colorless clear solution. . The pentane was further removed under a reduced pressure of about 0.1 torr to obtain a colorless liquid compound [-Si (CH ₃ ) (CH ₂ CH ₂ Cl ₃ ) O-] ₄ in 95% yield. 11.28 mmol (10.0 g) of this compound was diluted with 500 ml of tetrahydrofuran, and 136.71 mmol (13.83 g) of triethylamine was added thereto. After the reaction vessel was lowered to -78, methyl alcohol 136.71 mmol (4.38 g) was added slowly, and the reaction temperature was gradually raised to room temperature. Thereafter, the reaction was performed at room temperature for 15 hours, filtered through celite, and volatiles were removed under reduced pressure of about 0.1 torr. 100 ml of pentane was added thereto, and after stirring for 1 hour, the clear, colorless solution obtained by filtering through celite was removed under a reduced pressure of about 0.1 torr. Was obtained in 94% yield.

Example 5 Silicon Precursor D Synthesis of a Cage Structure

7.194 mmol (10.0 g) of octa (chlorosilylethyl) -PoSS (Polyhedral Oligomeric Silsesquioxane) was diluted with 500 ml of tetrahydrofuran and 63.310 mmol (6.41 g) of triethylamine was added. Subsequently, the reaction temperature was lowered to -78, and methyl alcohol 63.310 mmol (2.03 g) was slowly added, and then the reaction temperature was gradually raised to room temperature. After the reaction was performed at room temperature for 20 hours, the mixture was filtered through celite and volatiles were removed under reduced pressure of about 0.1 Torr. 100 ml of pentane was added thereto, stirred for 1 hour, filtered through celite to obtain a colorless clear solution, and pentane was further removed from the solution under reduced pressure of about 0.1 Torr to have a cage structure. Silicon precursor (D) was obtained. The precursors were dissolved in CDCl ₃ and measured by NMR.

¹ H NMR (300 MHz): 0.11 (s, 48H, 8 ×-[CH ₃ ] ₂ ), 0.54-0.68 (m, 32H, 8 × -CH ₂ CH _2- ), 3.43 (s, 24H, 8 × -OCH ₃ )

Example 5 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (A)

XX g (based on the monomer: xx mol) of the PEDOT-based conductive polymer solution prepared in Example 1 and xx g (xx mol) of the bridge-shaped silicon precursor (A) prepared in Example 2 for 1 hour using a magnetic bar stirrer. The mixed solution at room temperature was coated on a polyethylene terephthalate substrate at 3,000 rpm for xx minutes using a spin coater to obtain a thin film. The substrate coated with the conductive polymer composition was dried and cured at 70 ° C. for 30 minutes, and washed with a sufficient amount of distilled water. The thin film was dried at room temperature and subjected to surface resistance, permeability, solvent resistance, and pencil hardness test. The results are summarized in Table 1.

Example 6 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (A)

The experiment was conducted under the same process conditions as in Example 5 except that the drying and curing temperatures of the coated substrate were 80 degrees.

Example 7 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (A)

The experiment was conducted under the same process conditions as in Example 5 except that the drying and curing temperatures of the coated substrate were set to 90 degrees.

Example 8 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (B)

The polyfunctional silicon precursor was tested under the same process conditions as in Example 5 except for using the precursor (B).

Example 9 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (B)

The experiment was conducted under the same process conditions as in Example 8 except that the drying and curing temperatures of the coated substrate were 80 degrees.

Example 10 Coating of Compositions Consisting of PEDOT and Bridged Silicon Precursors (B)

The experiment was conducted under the same process conditions as in Example 8 except that the drying and curing temperatures of the coated substrate were set to 90 degrees.

Example 11 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (C)

The polyfunctional silicon precursor was tested under the same process conditions as in Example 5 except for using the precursor (C).

Example 12 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (C)

The experiment was conducted under the same process conditions as in Example 11 except that the drying and curing temperatures of the coated substrate were 80 degrees.

Example 13 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (C)

The experiment was conducted under the same process conditions as in Example 11 except that the drying and curing temperatures of the coated substrate were set to 90 degrees.

Example 14 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (D)

The polyfunctional silicon precursor was tested under the same process conditions as in Example 5 except for using the precursor (D).

Example 15 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (D)

The experiment was conducted under the same process conditions as in Example 14 except that the drying and curing temperatures of the coated substrate were 80 degrees.

Example 16 Coating of a Composition Composed of PEDOT and Bridged Silicon Precursor (D)

The experiment was conducted under the same process conditions as in Example 14 except that the drying and curing temperatures of the coated substrate were set to 90 degrees.

Comparative Example 1. PEDOT Coating

The experiment was carried out under the same conditions as in Example 5 except that the PEDOT-based conductive polymer was coated without using a polyfunctional precursor, and the drying and curing temperatures of the coated substrate were set at 120 degrees.

Comparative Example 2. PEDOT + TEOS Coating

Tetraorthosilicate (TEOS) was used in place of the polyfunctional precursor, and the experiment was conducted under the same conditions as in Example 5 except that the drying and curing temperature of the coated substrate was 120 degrees.

Comparative Example 3. PEDOT + MTMS Coating

Methyltrimethoxysilane (MTMS) was used instead of the multifunctional precursor, and the experiment was conducted under the same conditions as in Example 5 except that the drying and curing temperature of the coated substrate was 120 degrees.

Mechanical properties Basic properties Solvent resistance ⁽¹⁾ (times) Pencil Hardness ⁽²⁾ (H) Surface Resistance ⁽³⁾ (kO / sq) Permeability ⁽⁴⁾ (%) Example 5 > 50 4 48 85 Example 6 > 50 4 56 88 Example 7 > 50 5 63 86 Example 8 > 50 5 9 90 Example 9 > 50 5 12 87 Example 10 > 50 5 11 84 Example 11 > 50 4 5 88 Example 12 > 50 4 8 83 Example 13 > 50 5 11 89 Example 14 > 50 4 10 87 Example 15 > 50 4 15 83 Example 16 > 50 4 21 82 Comparative Example 1 One <1 0.5 70 Comparative Example 2 10 2 3 89 Comparative Example 3 2 2 3 87

Table 1 Comparison of conductive thin film characteristics

⁽¹⁾ Solvent resistance test: The number of times the IPA is wetted with a cotton swab and the film is peeled off during rubbing with a constant force.

⁽²⁾ Pencil hardness meter, ⁽³⁾ Surface resistance: (Changmin 4-point probe), ⁽⁴⁾ Transmittance: 550 nm using UV-Vis spectrometer (UV-VIS, US / 8453, Hewlett packard) Permeability relative to PET film

According to the present invention, as shown in the comparative examples and examples, the mechanical properties of the thin film excellent in the case of using a polyfunctional silicon precursor having at least one silicon of the present invention as compared to the inorganic binder composed of conventional silicon one atom (solvent resistance) , Hardness). In addition, in the case of using silicon alkoxide, an oligomeric silicate sol obtained by conducting a sol-gel reaction in which water and a catalyst are introduced under appropriate reaction conditions before mixing with a conductive polymer solution should be used. The existing method can be improved in terms of the simplicity of the process that allows simple mixing with the conductive polymer solution and the economics of the process that enables the low temperature curing process, and it is expected to be industrially useful when applied to the actual process.

Claims (8)

10 to 90% by weight of a conductive polymer solution consisting of a conductive polymer, an oxidant, a dopant and a solvent, and a composition consisting of 90 to 10% by weight of a polyfunctional silicon precursor, when coated on the adherend, the conductivity is 10 ⁵ ? Conductive coating composition characterized in that the content of more than 80%, excellent organic solvent resistance and film hardness of more than 4H The conductive polymer according to claim 1 is a polymer compound having transparency and conductivity obtained from at least one monomer selected from the group consisting of aniline and aniline derivatives, blood and pyrrole derivatives or 3,4-ethylenedioxythiophene and derivatives thereof. Conductive polymer coating composition, characterized in that the polyaniline, polypyrrole or polydioxyethylenethiophene The at least one compound selected from the group consisting of iron chloride, ferric toluenesulfonate, ferricdodecylbenzene sulfonate, and ferric anthraquinonesulfonate as claimed in claim 1, has a monomer and molar ratio of 1: 1 to 1:10. Conductive polymer coating composition, characterized in that the range of The dopant of claim 1 is para toluene sulfonic acid, dodecyl benzene sulfonic acid, anthraquinone sulfonic acid, 4-hydroxy benzene sulfonic acid, methyl sulfonic acid, nitrobenzene sulfonic acid, polystyrene sulfonic acid, poly (styrene-co-styrene sulfonic acid), poly ( At least one compound selected from the group consisting of 2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylonitrile is used in the range of 1: 1 to 1:10 with a monomer and molar ratio of the conductive polymer. Conductive polymer coating composition The solvent in claim 1 is water or alcohol having 1 to 5 carbon atoms or formamide, N-methylformamide, N, N-dimethylform, such as methanol, ethanol, propanol, isopropanol, normal butanol, sec-butanol, tert-butanol. At least one solvent or mixed solvent selected from the group consisting of an amide solvent such as amide or a sulfoxide solvent such as methyl sulfoxide or dimethyl sulfoxide is used in the range of 1:30 to 1: 200 based on the conductive polymer monomer. Conductive polymer coating composition, characterized in that The conductive polymer coating composition of claim 1, wherein the multifunctional silicon precursor is a bridged silicon precursor represented by the following chemical formula.

Wherein R 'is phenylene and phenylene derivatives, thiophene and thiophene derivatives, 3,4-ethylenedioxythiophene and derivatives thereof or acetylene and derivatives thereof, X1, X2 and X3 are independently C1 to C3 alkyl group , A C1-C10 alkoxy group, or a halogen atom. The conductive polymer coating composition of claim 1, wherein the polyfunctional silicon precursor is a cyclic silicon precursor represented by the following formula (2).

Wherein R is a hydrogen atom, a C1-C3 alkyl group, a C3-C10 cycloalky group or a C6-C15 allyl group, X1, X2, X3 are independently C1-C3 Is an alkyl group, a C1-C10 alkoxy group, or a halogen atom, p is an integer of 3-8, and m is an integer of 1-10. The conductive polymer coating composition of claim 1, wherein the multifunctional silicon precursor is a cage-type silicon precursor represented by the following formula (3).

In the above formula, X1, X2, X3 are independently an alkyl group of C1-C3, an alkoxy group of C1-C10 or a halogen atom, n is an integer of 1-10.