KR20130066384A - Coating composition comprising aniline terminated waterborne polyurethane and carbon nanotube - Google Patents

Abstract

PURPOSE: A coating composition is provided to have excellent abrasion resistance and electric conductivity, thereby being effectively applied to a floor material, electronic material film, heat-radiant sheet, a heating sheet, footwear sheet, and an insole sheet for shoes. CONSTITUTION: A coating composition contains carbon nanotubes and water-dispersible polyurethane with an aniline-terminated group. The mixing ratio of the water-dispersed polyurethane and carbon nanotubes with the aniline terminal group is 1:0.2-0.6(w:w). The water-dispersible polyurethane with the aniline terminal group has a structure in which an isocyanate group in a prepolymer side chain is capped with aniline. As aniline added amount increases, average particle diameter increases, and transmittance in a visible light is reduced.

Description

Coating composition containing water dispersible polyurethane having aniline end groups and carbon nanotubes {Coating composition comprising aniline terminated waterborne polyurethane and carbon nanotube}

The present invention relates to a coating composition having excellent electrical conductivity and abrasion resistance containing a water dispersible polyurethane having an aniline end group and carbon nanotubes.

Polyurethane (PU) is a urethane group formed by the reaction of a polyol having two or more hydroxyl groups (-OH) at the end of a molecule and a diisocyanate group having two isocyanate groups. It is a polymer which has a structure of NHCOO-] _n repeatedly (nonpatent literature 1 and 2). This polyurethane can control various properties according to the content of soft segment and hard segment. Therefore, it is applied to a wide range of fields such as paints, rubbers, leathers, fibers, adhesives, and glass or metal materials. It is widely utilized (nonpatent literature 1 and 2). However, polyurethane has been mainly used organic solvents such as benzene, toluene, xylene in the manufacturing process due to the strong hydrophobicity of the polyol. However, the oil-based polyurethane produced in this way emits volatile organic compounds in the manufacturing process or use process, which not only poses a risk of fire, but also causes air pollution. Therefore, in recent years, waterborne polyurethane dispersion (WPUD) manufactured using water as a solvent without using an organic solvent for environmental preservation or improvement of working environment has been in the spotlight (Non-Patent Documents 3 and 4). The water-dispersible polyurethane is produced by inducing an ionomer type by introducing a polar ion group into the polyurethane structure in order to disperse the hydrophobic resin well in water without the addition of an external emulsifier (Non-Patent Documents 5 to 7). .

First discovered in 1991, carbon nanotubes (CNTs) are divided into single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). It has thermal, electrical characteristics (Non Patent Literature 8). As a result, carbon nanotubes are becoming more versatile in engineering, such as the electronics, telecommunications, and automotive industries.In particular, in Japan and China, carbon nanotubes have been introduced for mass synthesis of multi-walled carbon nanotubes using fluidized reactors. Research on synthesis and application has been actively carried out at home and abroad (Non-Patent Documents 9-11).

On the other hand, in order to use carbon nanotubes as a conductive film or to manufacture other electronic devices, carbon nanotubes must be dissolved in a solution or a binder, but carbon nanotubes have a strong van der waals force. Because of the agglomeration of the bundle into bundles, it tends to agglomerate and collide within the matrix by the strong van der Waals forces. Therefore, when the carbon nanotubes are agglomerated in the matrix, the carbon nanotubes may not exhibit the inherent properties of the carbon nanotubes or may have a problem in that the uniformity of the properties may be degraded when manufacturing the thin film. In addition, due to the inherent properties of carbon nanotubes, it is not easy to obtain a dispersion in which carbon nanotubes are sufficiently dispersed by using conventional commercial dispersants, so that carbon nanotubes are uniformly dispersed or dissolved in a solvent or a resin. There is a need for the development of dispersants for the purpose.

Therefore, in order to solve this problem, in the present invention, a polyurethane prepolymer is prepared from polycarbonate diol, diisocyanate, and dimethylol propionic acid (DMPA), and the polyurethane Capping the terminal isocyanate groups in the backbone of the prepolymer with aniline (anillin) to synthesize aniline terminated waterborne polyurethane (aniline terminated waterborne polyurethane) having aniline end groups were used as a dispersant for carbon nanotubes. That is, the present inventors mix the water-dispersible polyurethane having the aniline end group with the multi-walled carbon nanotubes dispersed in water to prepare a new type of conductive coating composition having excellent abrasion resistance and electrical conductivity. Could complete.

<Non Patent Literature 1>

Yoo, JS and Chun, HJ, Application of Polyurethane Adhesives, Polymer Science and Technology , 1999, 10 (5), 578-588.

<Non Patent Literature 2>

Dieterich, D., Aqueous Emulsions, Dispersions and Solution of Polyurethanes; Synthesis and Properties. I, Angew . Macromol . Chem ., 98, 1981, 281-340.

<Non Patent Literature 3>

Hepburn, C., Polyurethane Elastomer, Elsevier, London, 1982.

<Non Patent Literature 4>

Cooper, SL and Tobosky, AV, Properties of Linear Elastomer Polyurethane, J. Appl . Polym . Sci ., 1966, 10, 1837-1844.

<Non Patent Literature 5>

Shin, YT, Hong, MG, Choi, JJ, Lee, WK, Lee, GB, Yoo, BW, Lee, MG and Song, KC, Preparation and Properties of Aminosilane Terminated Waterborne Polyurethane, Korean Chem. Eng. Res. , 2010, 48 (4), 434-439.

<Non Patent Literature 6>

Hong, MG, Shin, YT, Choi, JJ, Lee, WK, Lee, GB, Yoo, BW, Lee, MG and Song, KC, Preparation of Silylated Waterborne Polyurethane / Silica Nanocomposites Using Colloidal Silica, Ibid. , 2010, 48 (5), 561-567.

<Non Patent Literature 7>

Shin, YT, Hong, MG, Choi, JJ, Lee, WK, Yoo, BW, Lee, MG and Song, KC, Effect of Addition of Pentaerythritol Triacrylate on the Properties of Waterborne Polyurethane, Ibid . , 2011, 49 (4), 411-416.

<Non Patent Literature 8>

Yun, S., Im, H. and Kim, J., Dispersity and Electro-conductivity of PU Grafted MWCNT / PU Composite via Simple Blending Method, Appl . Chem . Eng . , 2010, 21, 500-504.

<Non Patent Literature 9>

Lee, J., K., Choi, H., O., Kim, E., B., Kim, S., Y., and Ju, C., D., Surface Resistance and Tensile Strength of Polyester Resin by Anti-static Agents, Korean Chem . Eng . Res . , 2010, 48 (5), 638-642.

<Non Patent Literature 10>

Han, JH Current Status on Synthesis of Carbon Nanotubes and Their Applications to Conducting Polymer, Polymer Science and Technology , 2005, 16 (2), 162-175.

<Non Patent Literature 11>

Lin, MF, Tsen, WC, Shu, YC and Chuang, FS, Effect of Silicon and Phosphorus on the Degradation of Polyurethanes, J. Appl . Polym . Sci . , 79 (5), 2001, 881-899.

<Non Patent Literature 12>

ASTM D 3359, Standard Test Methods for Measuring Adhesion by Tape Test, ASTM International , 1197, 927-929.

<Non Patent Literature 13>

Hwang, JH and Song, KC, Preperation of UV-Curable Organic-Inorganic Hybrid Hard Coatings Using Alumina Sols and Acrylate Monomers, Korean Chem . Eng . Res . , 2011, 49 (3), 277-284.

An object of the present invention is to provide a coating composition containing a water dispersible polyurethane having aniline end groups and carbon nanotubes.

The present invention relates to a coating composition containing a water dispersible polyurethane having aniline end groups and carbon nanotubes.

The water dispersible polyurethane composition having an aniline end group has a structure in which an isocyanate group in the side chain of the polyurethane prepolymer is capped with aniline. As the amount of aniline added increases, the average particle diameter of the water-dispersed polyurethane increases and the transmittance Is decreased.

In addition, the water-dispersible polyurethane having the aniline end group,

To the polyurethane prepolymer having an isocyanate group prepared by mixing diisocyanate, polycarbonate diol and dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone, aniline was added to prepare a polyurethane prepolymer having an aniline end group, After neutralizing it,

It may be prepared by dispersing the polyurethane prepolymer having the neutralized aniline end groups and adding a chain extender.

The polyurethane prepolymer having the aniline end group,

0.015 to 0.05 mol diisocyanate, 0.03 to 0.07 mol polycarbonate diol, and 0.001 to 0.04 mol of dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone are mixed with a polyurethane prepolymer having an isocyanate group. It can be prepared by adding 0.02 mol of aniline.

When preparing the polyurethane prepolymer having an isocyanate group, a catalyst may be used, and dibutyltin dilaurate and stainus octoate may be used as the catalyst, and may be used at a concentration of 0.00001 to 0.00008 mol.

The diisocyanate may comprise at least one compound of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate and 4,4-dicyclohexylmethane diisocyanate Can be.

The polyurethane prepolymer having the isocyanate group may be prepared by reacting dimethylol propionic acid dissolved in diisocyanate, polycarbonate diol and 1-methyl-pyrrolidinone at 50 to 100 ° C. for 1 to 5 hours. In the polyurethane prepolymer having an isocyanate group, the molar ratio of the isocyanate group and the hydroxyl group of the polycarbonate diol is preferably 1: 1.0 to 1.5.

In addition, the neutralizing agent used for the neutralization reaction of the polyurethane prepolymer having an aniline end group is characterized in that at least one compound selected from triethylamine, potassium hydroxide and ammonia. By using a neutralizing agent when preparing the polyurethane prepolymer, the carboxyl group formed by adding dimethylol propionic acid can be neutralized. The neutralizing agent can be reacted at 30 to 70 ° C for 0.5 to 3 hours.

As the chain extender, one or more compounds selected from the group consisting of ethylenediamine, 1,6-hexanediol, diethylenetriamine, hydrazine, isophoronediamine, morpholine, and 1,4-butanediol may be used. By adding an extender and reacting, the polymerization reaction of the composition can be enhanced. The chain extender can be reacted for 0.5 to 2 hours.

The mixing ratio of the coating composition containing the water-dispersible polyurethane having the aniline end group and the carbon nanotube may be 1: 0.2 to 0.6 (w / w). Preferably, a carbon nanotube dispersion is mixed with the water-dispersible polyurethane having the aniline end group to prepare a coating solution, and may be mixed by reacting at room temperature for 0.5 to 2 hours. The carbon nanotube dispersion is in a state in which carbon nanotubes are dispersed in water at 2.0 to 4.0 wt%, and may be multi-walled carbon nanotubes, and the multi-walled carbon nanotubes have an average diameter of 10 to 50 nm and 1 to 25 nm. It may be a multi-walled carbon nanotube having an average length of μm.

Therefore, the manufacturing method of the coating composition containing the water-dispersible polyurethane which has the aniline end group of this invention, and a carbon nanotube, Preferably,

Mixing a diisocyanate, polycarbonate diol and dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone to prepare a polyurethane prepolymer having an isocyanate group;

Preparing a polyurethane prepolymer having an aniline end group by adding aniline to the polyurethane prepolymer having a diisocyanate group;

Adding a neutralizing agent to the polyurethane prepolymer having the aniline end group;

Dispersing the polyurethane prepolymer having the aniline end group to which the neutralizing agent is added;

Preparing a water dispersible polyurethane having an aniline end group by adding a chain extender to the water dispersible composition; And

And adding multi-walled carbon nanotubes to the water-dispersible polyurethane having the aniline end groups.

More preferably,

Preparing a polyurethane prepolymer having an isocyanate group by mixing 0.01 to 0.05 mol diisocyanate, 0.03 to 0.07 mol polycarbonate diol and 0.001-0.04 mol of dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone;

Preparing a polyurethane prepolymer having an aniline end group by adding 0.005 to 0.02 mol of aniline to the polyurethane prepolymer having a diisocyanate group;

Adding 0.005 to 0.04 mol of a neutralizer to the polyurethane prepolymer having the aniline end group;

Adding water to a polyurethane prepolymer having an aniline end group to which the neutralizing agent is added;

Preparing a water dispersible polyurethane having an aniline end group by adding 0.001 to 0.03 mol of a chain extender to the water dispersible composition; And

It may include; adding a multi-walled carbon nanotubes 1: 0.2 ~ 0.6 (w: w) in a mixing ratio to the water-dispersible polyurethane having the aniline end group.

The coating composition containing the water-dispersible polyurethane and carbon nanotubes having the aniline end groups according to the present invention has better wear resistance and electrical conductivity than the conventional water-dispersible polyurethane composition or the conductive coating composition prepared by using carbon nanotubes. Thus, it can be efficiently applied to various conductive sheets, conductive film, conductive clothing, conductive sheet support layer, flooring made of conductive sheet, electronic material film, heat dissipation sheet, heat sheet, shoe sheet, shoe insole sheet. .

1 is an FT-IR spectrum analysis result of the polyurethane prepolymer, Figure 1.a is a FT-IR spectrum analysis of the polyurethane prepolymer obtained by reacting polycarbonate diol, isophorone diisocyanate and dimethylol propionic acid for 3 hours As a result, Figures 1b and c are the results of FT-IR spectra analysis of the polyurethane prepolymer having the aniline end obtained by reacting the polyurethane prepolymer with aniline for 1 to 2 hours.
2 shows the results of measurement of transmittance for water-dispersible polyurethanes A0, A1, A2, and A3 having an aniline end group using a spectrophotometer (UV-Visible spectrometer, UV-2450, Shimadzu).
Figure 3 is a photograph showing the particle size and the distribution state of the composition using a transmission electron microscope for the water-dispersible polyurethane composition having aniline end groups and the coating composition containing multi-walled carbon nanotubes A3CNT.
Figure 4 shows the results of analyzing the average particle diameter of the water-dispersible polyurethane composition having aniline end groups using a particle size analyzer.
5 is a result of measuring the surface resistance of the coating film made of A0CNT, A1CNT, A2CNT and A3CNT coating composition containing a water-dispersible polyurethane composition having aniline end groups and multi-walled carbon nanotubes (confirming the electrical conductivity) Indicates.
Figure 6 shows the results of measuring the surface resistance of the coating film of the coating composition A3CNT1, A3CNT2 and A3CNT3 prepared by varying the addition amount of the water-dispersible polyurethane composition having aniline end groups and the multi-walled carbon nanotubes (conductivity confirmation) .

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

&Lt; Example 1: Preparation of material for producing coating >

To prepare the coating composition of the present invention, aliphatic isoprone diisocyanate (98%, Aldrich) was used as diisocyanate, and polycarbonate diol (1000 g / mol, Asahi Kasei, product catalog number: CAS 61630-98- 6) was used as polyol. Dimethylolpropionic acid (98%, Aldrich) was used as an anionic group added for water dispersion, and 1-methyl-pyrrolidinone (1-methyl-2-) was used as a solvent for dissolving dimethylolpropionic acid. pyrolidinone, NMP, 99%, Aldrich) was used.

Also, dibutyltin dilaurate (DBTL, 95%, Aldrich) was used as a catalyst. An aniline (99.5%, Aldrich) having an aromatic structure was used for capping the residual isocyanate group of the obtained polyurethane prepolymer. Triethylamine (triethylamine, TEA, 99.5%, Aldrich) was used as a neutralizing agent, and ethylene diamine (ethylene diamine, EDA, 99%, Aldrich) was used as a chain extender. As carbon nanotubes to be mixed with the water-dispersible polyurethane having an aniline end group, multi-walled carbon nanotubes (3.0 wt%, World Tube, Korea), which are dispersed in water, were used. The above reagents were used without purification and chemical treatment.

Example 2 Preparation of Coating Composition Containing Water Dispersible Polyurethane Having Aniline End Groups and Multi-Walled Carbon Nanotubes

2-1. Preparation of Polyurethane Prepolymer Having Isocyanate Group

In a 500 ml four-necked flask connected with a thermometer, a condenser, a constant temperature bath and a stirrer, 0.0585 mol of isopron diisocyanate, 0.03 mol of polycarbonate diol, 0.015 mol of dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone, a catalyst After adding 0.000045 mol of dibutyl tin dilaurate and reacting at 500 rpm for 3 hours at 75 ° C., a polyurethane prepolymer having an isocyanate group was prepared. At this time, the molar ratio of the isocyanate group and the hydroxyl group of the polycarbonate diol was fixed at 1.3.

2-2. Preparation of Prepolymer Having Aniline End Groups

When the polyurethane prepolymer of Example 2-1 was prepared, the amount of aniline was adjusted to 0, 0.0075, 0.010, and 0.015 mol, respectively, and reacted at 50 ° C. for 2 hours to cap the residual isocyanate group remaining in the prepolymer with aniline. Polyurethane prepolymers having aniline end groups were prepared.

2-3. Preparation of Water Dispersible Polyurethane Having Aniline End Group

After that, 0.015 mol of triethylamine can be added to neutralize the carboxyl acid (COOH, carboxyl acid) group in the prepolymer formed by the addition of dimethylol propionic acid, and neutralized at 50 DEG C for 1 hour to be stably dispersed in water. After the addition of 120 g of distilled water, water was dispersed at 1,000 rpm for 20 minutes, and ethylene diamine was added as a chain extender and chain extended at 30 ° C. for 1 hour to obtain water having an aniline end group. Acidic polyurethanes were prepared. The chemical composition of the water-dispersible polyurethane composition having the aniline end groups is shown in Table 1.

Condition Concentration (mol) soft
Segment
Hard segment
Capping agent chain
Extenders
catalyst
corrector Polycarbonatediol
(PCD) Isophorone diisocyanate
(IPDI) Dimethylol
Propionic acid
(DMPA)
aniline
(aniline) Ethylenediamine
(EDA) Dibutyl tin dilaurate
(DBTL) tree
Ethylamine
(TEA) A0
(Comparison group)
0.03
0.0585
0.015
0.0000
0.0135
0.000045
0.015 A1 0.03 0.0585 0.015 0.0075 0.0097 0.000045 0.015 A2 0.03 0.0585 0.015 0.0100 0.0085 0.000045 0.015 A3 0.03 0.0585 0.015 0.0150 0.0060 0.000045 0.015

In addition, the synthesis process of the aniline terminated waterborne polyurethane (aniline terminated waterborne polyurethane) having the aniline end group shown in the following formula (1).

2-4. aniline Horse short  Water-dispersible polyurethane and Multiwall  Preparation of Coating Composition Containing Carbon Nanotubes-①

When a water-dispersible polyurethane composition having aniline end groups (A0 to A3, A0 is a comparative group) is prepared, 10 g of each composition and 4 g of multi-walled carbon nanotubes having a state dispersed in water are mixed for 1 hour. A composite coating composition (A0CNT-A3CNT, A0CNT is a comparative group) containing a water-dispersible polyurethane having aniline end groups and a multi-walled carbon nanotube was prepared (see Table 2).

Condition A0CNT
(Comparison group) A1CNT A2CNT A3CNT Having aniline end groups
Type of Water Dispersible Polyurethane (g) A0
(Comparison group) A1 A2 A3 Having aniline end groups
Weight of Water Dispersible Polyurethane (g) 10 10 10 10  Weight of Multi-walled Carbon Nanotubes (g) 4 4 4 4

2-5. aniline Horse short  Water-dispersible polyurethane and Multiwall  Preparation of Coating Composition Containing Carbon Nanotubes-②

In addition, the coating compositions A3CNT1, A3CNT2, A3CNT3, A3CNT4 and A3CNT5 shown in Table 3 were prepared by changing the amounts of multi-walled carbon nanotubes added to 10 g of A3 sample in Table 1, respectively, to 2, 4, 6, 8 and 10 g.

Condition A3CNT1 A3CNT2 A3CNT3 A3CNT4 A3CNT5 Weight (g) of water dispersible polyurethane with 'A3' aniline end groups 10 10 10 10 10 Weight of Multi-walled Carbon Nanotubes (g) 2 4 6 8 10

< Example  3. Aniline Terminal group  A water-dispersible polyurethane coating composition having an aniline Terminal group  Water-dispersible polyurethane and Multiwall  Physical Properties Analysis of Coating Composition Containing Carbon Nanotubes>

3-1. FT - IR ( Fourier transform spectroscopy ) Polyurethane through spectroscopic analysis Prepolymer  aniline Capping  Confirm

Confirming that the polyurethane prepolymer was aniline capping The polyurethane prepolymer of the reaction steps of Examples 2-1 and 2-2 was applied thinly on a potassium bromide (KBr) plate and then FT-IR (FTIR-8400S, Shimadzu) was used to measure the progress of the reaction between the main functional group and the isocyanate group, which is shown in FIG. 1.

Fig. 1.A is a result of FT-IR spectra analysis of a polyurethane prepolymer (prepolymer of Example 2-1) obtained by reacting polycarbonate diol, isophorone diisocyanate with dimethylol propionic acid for 3 hours. Results for an A1 polyurethane prepolymer added with 0.0075 mol of aniline prepared at -2. Figures 1b and c are FT-IR spectrum analysis results of the polyurethane prepolymer (prepolymer of Example 2-2) having the aniline end obtained by reacting the polyurethane prepolymer with aniline for 1 to 2 hours. Figure 1.a -NH stretching in the peak, in the vicinity of 1,700cm ^-1 -C = O band, -CH ₂ band at 2,900cm ^-1 region, -CO band, 2,260 in the vicinity of 1,100cm ^-1 in the vicinity of 3,300cm ^-1 It can be seen that the polyurethane prepolymer was synthesized by confirming the peak for the isocyanate group in the vicinity of cm ⁻¹ . In addition, it can be seen from FIGS. 1.b and c that the isocyanate group of the polyurethane prepolymer side chain is capped with aniline because the peak intensity of the isocyanate group in the vicinity of 2,260 cm ⁻¹ decreases as the reaction time increases after the addition of aniline.

3-2. aniline Terminal group  Physicochemical Properties of Water Dispersible Polyurethane Compositions

As the reaction time increases after the addition of aniline, as confirmed in FIGS. 1.b and c, the peak intensity for the isocyanate group (NCO) at around 2,260 cm ⁻¹ is weakened to the isocyanate group of the polyurethane prepolymer side chain with aniline. You can see that it is capped.

2 is a measurement of transmittance for water-dispersible polyurethanes A0, A1, A2, A3 having aniline end groups using a UV-Visible spectrometer (UV-2450, Shimadzu) (using the same method as in Example 3-7) As the amount of aniline added increased, the turbidity increased in the visible region, and the more aniline added during synthesis, the more aniline was capped in the polyurethane main chain, thus decreasing the transmittance of the water-dispersible polyurethane having an aniline end group. I think that.

3-3. Transmission electron microscope ( transmission electron microscope , TEM Particle size and shape analysis

In order to investigate the particle size and shape of the coating composition containing the water-dispersible polyurethane having aniline end groups and the multi-walled carbon nanotubes, each coating composition was diluted 1:50 in water to form a grid (mesh grid, copper, diameter). 16 mm, 0.15 mm thick), and dried at room temperature, and then measured and analyzed the particle size and shape of the coating film under an acceleration voltage of 80 kV using transmission electron micrographs (TEM, JEOL 2000-FXII, Japan). The results are shown in FIG. 3.

FIG. 3 is a photograph of particle size and shape of a water-dispersible polyurethane composition having aniline end groups and A3CNT, which is a coating composition containing multi-walled carbon nanotubes, measured using a transmission electron microscope. Carbon nanotubes and water-dispersible polyurethanes with small spherical aniline end groups of 10-20 nm in diameter coexisted. Through this, it was confirmed that the coating composition of the present invention existed in a physically simple mixed state in which chemical bonding did not occur between the water-dispersible polyurethane having the aniline end group and the multi-walled carbon nanotube particles.

3-4. Water-soluble polyurethane containing no aniline and aniline Terminal group  Of the water-dispersible polyurethane Check the size

Particle size analysis using dynamic light scattering method to determine the particle size of the water-dispersible polyurethane composition A0 and the water-dispersible polyurethane composition A1, A2 and A3 having the aniline end groups of Example 2-3 , DLS, Nicomp, model 380, USA) and the analysis results are shown in FIG. 4.

As shown in FIG. 4, the average particle diameter of pure water-dispersible polyurethane A0 was 13 nm, but the A1, A2, and A3 water-dispersible polyurethane compositions having aniline ends showed average particle diameters of 25 nm, 33 nm, and 40 nm, respectively. As it increased, the average particle diameter increased. It was analyzed that the more aniline added during the synthesis, the more the aniline was capped in the polyurethane main chain, the size of the formed particles increased, and the average particle size of the water-dispersible polyurethane having an aniline end group was also increased. As the particle size increases, as the amount of aniline having an aromatic structure increases, the water-dispersed polyurethane The average particle size increases and the proportion of the hard segment in the polyurethane structure also increases, resulting in excellent abrasion resistance of the coating film.

3-5. Pencil hardness and adhesion

In order to confirm the shape of the pencil hardness and adhesion of the coating composition of the present invention, after spin coating the respective coating compositions of Examples 2-4 and 2-5 on a polycarbonate substrate, the coating composition was heated at 120 ° C. for 30 minutes. It was heat cured for a while to prepare a coating film.

The pencil hardness was measured to push the hardened layer Put the pencil for pencil hardness measured in a pencil hardness tester (CT-PC1, CORE TECH, Korea) caught by 45 ^o angle, while applying a constant load (1kg). As a pencil, Mitsubishi pencil was used, and pencils showing strengths such as H-9H, F, HB, and B-6B were used.

In order to confirm the adhesive force, the method disclosed by ASTM D 3359 [Nonpatent Document 12] was referred to. To this end, 100 squares are made by applying a checkerboard shape at 11 × 11 intervals at 1 mm intervals with a cutter on the cured coating layer, and the 3M tape is adhered to it well and peeled off several times with a constant force. The degree of adhesion was observed. 5B for 100, 3B for more than 85, 4B for more than 85, 2B for over 65, 1B for over 35, and 0B for less than 35.

The results for the pencil hardness and adhesion are shown in Table 4 and Table 5, respectively.

Condition A0CNT A1CNT A2CNT A3CNT Pencil hardness 2B 2B 2B 2B Adhesion 5B 5B 5B 5B

Condition A3CNT1 A3CNT2 A3CNT3 A3CNT4 A3CNT5 Pencil hardness 2B 2B 2B 4B 4B Adhesion 5B 5B 5B 2B 2B

The results in Table 4 indicate that pencil hardness and adhesion of the coating film of the coating composition prepared by mixing 10 g of water-dispersible polyurethane compositions of A0, A1, A2 and A3 and 4 g of multi-walled carbon nanotubes prepared by varying the amount of aniline added, respectively. Indicates. Regardless of the change in the amount of aniline added in the sample in Table 4, both the pencil hardness of the coating film was confirmed as 2B, the adhesion of the coating film was also 5B and all showed excellent results.

The results in Table 5 indicate pencil hardness and adhesion of the coating film of the coating composition prepared by mixing the multi-walled carbon nanotubes 2, 4, 6, 8, and 10 g with 10 g of the water dispersible polyurethane composition having the aniline end group of A3, respectively. Indicates. In the case of A3CNT4 and A3CNT5, which had the highest amount of multi-wall carbon nanotubes, the pencil hardness was 4B and the adhesion strength was 2B, compared to other coating compositions. When the amount of multi-wall carbon nanotubes was increased by a certain amount, It was determined that the content of water in the coating composition increases, which adversely affects the physical properties of the coating film.

3-6. Surface resistance check (electrical conductivity)

In order to confirm the surface resistance of the surface of the coating film of the coating composition of the present invention, each coating composition was spin coated on a polycarbonate substrate, and then thermally cured at 120 ° C. for 30 minutes to prepare a coating film. The surface resistance was measured using a surface resistance measuring device (SIMCO, ST-3, Japan) under the condition of constant temperature, constant humidity, and are shown in FIGS. 5 and 6.

5 is A0CNT, which is a coating composition containing water-dispersible polyurethane and multi-walled carbon nanotubes containing no aniline, and A1CNT, A2CNT, which is a coating composition containing water-dispersible polyurethane and multi-walled carbon nanotubes having aniline ends, and This is the result of measuring the surface resistance to A3CNT. Referring to the results of FIG. 5, A0CNT, a coating composition without aniline, showed a surface resistance value of 10 ^10.9 / cm ² , but ACNT1, ACNT2, and ACNT3, respectively, with coating aniline added with 10 ^7.7 , It was confirmed that the surface resistance value of 10 ^7.7 , 10 ^7.6 / cm ² . However, regardless of the amount of aniline added, the surface resistance values of the aniline-added coating compositions showed similar values, indicating that a simple increase in the amount of aniline was not a significant factor in the electrical conductivity.

6 is a result of measuring the surface resistance of the coating composition A3CNT1, A3CNT2 and A3CNT3 obtained by changing the amount of multi-wall carbon nanotubes added to 2, 4 and 6g, respectively, in the water-dispersible polyurethane composition having aniline end groups. In this figure, as the addition amount of multi-walled carbon nanotubes increased to 2, 4, 6g, the surface resistivity decreased to 10 ^9.0 , 10 ^7.6 , 10 ^6.7 / cm ² , respectively. . However, when the excessive amount of multi-walled carbon nanotubes were added to 8 and 10g, it was difficult to check the surface resistance because the coating was not good, and the surface of the coating film was also not uniform. The mixing ratio of the polyurethane composition and the multi-walled carbon nanotubes was found to be 1: 0.2 to 0.6 (w / w).

3-7. Wear resistance

In order to measure the abrasion resistance of a film coated on a polycarbonate substrate, a wear tester (taber abraser, QM600T, Qmesys, Korea) was worn 100 times at a speed of 70 rpm under a weight of 500 g, followed by a UV-Visible spectrometer (UV). Wear resistance was measured using -2450, Shimadzu). To this end, the wear resistance was determined by measuring the transmittance of the coating film at 600 nm wavelength after each coating film was worn with a wear resistance wheel of 500 g weight at 70 rpm and 100 revolutions. The wear resistance of the coating film was determined by defining the transmission loss% (transmittance loss%) as follows, the higher the transmission loss% means that the wear resistance of the sample is not good.

Transmittance Loss% = 100 (BA) / B
A = transmittance (%) at 600 nm wavelength after measuring the wear resistance of the sample
B = transmittance (%) at 600 nm wavelength before measuring the wear resistance of the sample

In the above method, when measuring the wear resistance according to Table 6, in the case of the A0CNT coating composition made of pure water-dispersible polyurethane, the transmittance loss rate after abrasion of the coating film was 70%, but A1CNT and A2CNT samples were added with aniline. The loss rate of A3CNT was 43%, 38% and 32%, respectively. It was determined that as the amount of aniline having an aromatic structure increased, the ratio of hard segments in the polyurethane structure also increased, so that the wear resistance of the coating film was improved.

Claims (8)

A coating composition comprising a water dispersible polyurethane having aniline end groups and carbon nanotubes. The method of claim 1,
The coating composition is a coating composition, characterized in that the mixing ratio of water-dispersed polyurethane and carbon nanotubes having an aniline end group is 1: 0.2 ~ 0.6 (w: w). 3. The method according to claim 1 or 2,
The water-dispersible polyurethane having the aniline end group is 0.001 to 0.04 mol dimethylolpropy dissolved in 0.01 to 0.05 mol diisocyanate, 0.03 to 0.07 mol polycarbonate diol and 0.03 to 0.07 mol 1-methyl-pyrrolidinone. To the polyurethane prepolymer having an isocyanate group prepared by mixing onic acid, 0.005 to 0.02 mol aniline is added to prepare a polyurethane prepolymer having an aniline end group, which is at least one selected from triethylamine, potassium hydroxide and ammonia. After neutralizing with a neutralizing agent of 0.005 to 0.04 mol, the polyurethane prepolymer having the neutralized aniline end group is water-dispersed, and ethylenediamine, 1,6-hexanediol, diethylenetriamine, hydrazine, isophoronediamine, morpholine and It is prepared by adding 0.001 to 0.03 mol of at least one chain extender selected from the group consisting of 1,4-butanediol. Aniline end coating composition as water-dispersible characterized in that the polyurethane has a short. 3. The method according to claim 1 or 2,
The water-dispersible polyurethane having an aniline end group has a structure in which the isocyanate group of the polyurethane prepolymer side chain is capped with aniline, and as the amount of aniline added increases, the average particle size increases and transmittance decreases in the visible region. Coating composition, characterized in that the water-dispersible polyurethane having a terminal group. The method of claim 3, wherein
The diisocyanate is at least one compound of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate and 4,4-dicyclohexylmethane diisocyanate Coating composition containing a water-dispersible polyurethane and carbon nanotubes. The method of claim 3, wherein
The polyurethane prepolymer having an isocyanate group is a water dispersible polyurethane having an aniline end group, characterized in that the molar ratio of the isocyanate group and the hydroxyl group of the polycarbonate diol is 1: 1.0 to 1.5. 3. The method according to claim 1 or 2,
Carbon nanotubes of the coating composition is a multi-walled carbon nanotubes in a state dispersed in 2.0 to 4.0wt% in water having a mean diameter of 10 ~ 50nm, and an average length of 1 ~ 25㎛. Preparing a polyurethane prepolymer having an isocyanate group by mixing 0.01 to 0.05 mol diisocyanate, 0.03 to 0.07 mol polycarbonate diol and 0.001-0.04 mol of dimethylol propionic acid dissolved in 1-methyl-pyrrolidinone;
Preparing a polyurethane prepolymer having an aniline end group by adding 0.005 to 0.02 mol of aniline to the polyurethane prepolymer having a diisocyanate group;
Adding 0.005 to 0.04 mol of a neutralizer to the polyurethane prepolymer having the aniline end group;
Adding water to a polyurethane prepolymer having an aniline end group to which the neutralizing agent is added;
Preparing a water dispersible polyurethane having an aniline end group by adding 0.001 to 0.03 mol of a chain extender to the water dispersible composition; And
Adding multi-walled carbon nanotubes to the water-dispersible polyurethane having the aniline end groups in a mixing ratio of 1: 0.2 to 0.6 (w: w);
Method for producing a coating composition containing a water-dispersible polyurethane and carbon nanotubes having an aniline end group, characterized in that it is prepared.

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