KR20170134871A - Uniform coating method by high frequency dispersion spraying device - Google Patents

Abstract

The present invention relates to a method of coating silver nanowire uniformly by using a high-frequency dispersion spray, wherein the method comprises the steps of: dispersing 0.25wt% or less of silver nanowire in a dispersion solution containing a DMSO solvent to prepare a silver nanowire solution; heating a substrate to be coated with the silver nanowire; and spraying the dispersed silver nanowire solution onto the heated substrate by using a high-frequency dispersion spray nozzle. Additionally, the present invention relates to a composition for coating silver nanowire uniformly by using a high-frequency dispersion spray, which can achieve a fine and uniform coating at the level of few micrometers on a large area, and thus shows excellent integrity; and has higher durability and performance.

Description

TECHNICAL FIELD [0001] The present invention relates to a silver nanowire uniform coating method using a high frequency dispersing spray,

The present invention relates to a silver nanowire homogeneous coating method using a high frequency dispersing spray for producing a uniform conductive film having a constant conductivity value depending on its position.

Recently, attention has been focused on conductive nanoparticles capable of low-cost solution processing to replace materials such as indium tin oxide and Au, which are coated by chemical vapor deposition. Indium Tin Oxide and Au are mainly used as transparent electrode material for solar cell, and have excellent conductivity and chemical stability. However, since Indium Tin Oxide is a rare earth metal, it is in short supply compared to demand, and Au has a disadvantage of high price. As an alternative to this, a solution process using silver nanowires with high haze has been conducted while having excellent electrical conductivity and transparency.

In order to simplify the manufacturing process of the conventional electrode thin film, roll-to-roll printing, spray printing, and spin coating at room temperature and normal pressure are generally used. The roll-to-roll printing has a problem that it is difficult to adjust the position of the pattern, and it takes time to limit the pattern size and change the pattern. In the case of spray coating, since the metal or inorganic nanoparticle solution is not stable and dispersed over a long period of time, there is a problem that the composition of the coated thin film may be changed over time due to the characteristic of being influenced greatly by the viscosity of the solution. In addition, the solution of metal or inorganic nanoparticles is generally coated by a spin coating method, but the size of the substrate is limited, and an expensive solution is wasted by 80% or more, which is inefficient.

Recently, a technique to coat metal or inorganic nanoparticle materials with a micrometer thickness using a spray method has been developed to form an electrode thin film.

Conventional spray coating of metal or inorganic nanoparticles has difficulties in obtaining a uniform thickness and composition of the coating when the viscosity of the solution is high or when the particles are not stably dispersed in the solution. In addition, there is a disadvantage that the thin film coating of the spraying method is not suitable for large-area coating when the metal or inorganic nanoparticles are precipitated. On the other hand, as a method for uniformly large-area coating of the particles, the ultrasonic nozzle spray has high viscosity or disperses the nanoparticle solution through the ultrasonic wave continuously, so that it is not precipitated during the coating.

Korean Registered Patent Publication No. 10-1518223 (Announced 2015.05.08) Korean Patent Publication No. 10-2016-0033713 (published on March 28, 2016)

Disclosure of the Invention The object of the present invention is to solve the above-mentioned problems and to provide a high-frequency dispersing spray which can remarkably improve the uniformity of the coating to provide excellent performance and stability, And to provide a nanowire uniform coating method.

In order to achieve the above object, the silver nanowire uniform coating method using a high-frequency dispersion spray according to the present invention comprises dispersing silver nanowires in a dispersion solution containing a DMSO (dimethyl sulfoxide) solvent in an amount of 0.25 wt% Wire solution, heating the substrate on which the silver nanowire is to be coated, and spraying the dispersed silver nanowire solution onto the heated substrate with a high frequency dispersing spray nozzle.

The substrate may be heated above the boiling point of the silver nanowire dispersion solvent.

The heating temperature may be 190 캜 or higher.

The silver nanowire may have a length of 1 [mu] m to 200 [mu] m and a diameter of 20 nm to 1,300 nm.

The dispersion solution may be prepared by mixing 40 to 60 parts by weight of DMSO with respect to 50 parts by weight of ethanol.

The dispersion solution may contain a cellulose-based material as a stabilizer in a range of 0.5-1 weight per weight of the nanowire.

The cellulosic material may be selected from the group consisting of methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, methyl ethyl cellulose, carboxymethyl cellulose, and hydroxypropyl cellulose.

Accordingly, the present invention provides a silver nanowire thin film substrate coated on a substrate by the above method.

Also, the present invention provides a composition for uniform coating of silver nanowires using a high-frequency dispersion spray comprising 40 to 60 parts by weight of DMSO and 0.1 to 0.3 parts by weight of silver nanowires, based on 50 parts by weight of ethanol.

The silver nanowire uniform coating method using the high frequency dispersing spray according to the present invention has an advantage that fine and uniform coating can be performed at a level of several micrometers by suppressing the aggregation of the silver nanowire solution at the time of coating. In addition, the present invention has the advantage of improving the performance and stability of the electrode, and improving the chemical resistance and durability, by increasing the uniformity and having a constant electric conductivity regardless of the position.

1 is a scanning electron microscope photograph of the silver nanowire-coated thin film of Production Example 1. FIG.
2 is a scanning electron microscope photograph of the silver nanowire-coated thin film of Production Example 2. FIG.
3 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 3. FIG.
4 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 4. FIG.
5 is a scanning electron microscope photograph of the silver nanowire-coated thin film of Production Example 6. Fig.
6 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 8. Fig.
7 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 10. Fig.
8 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 11. Fig.
9 is a scanning electron microscope photograph of the silver nanowire-coated thin film of Production Example 12. Fig.
10 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 13;
11 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 14. Fig.
12 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 15. Fig.
13 is a scanning electron micrograph of the silver nanowire-coated thin film of Production Example 16. Fig.
14 is a scanning electron microscope photograph of the silver nanowire-coated thin film of Production Example 17. Fig.

Hereinafter, the present invention will be described in detail.

The silver nanowire uniform coating method using a high-frequency dispersion spray according to the present invention comprises the steps of dispersing silver nanowires in a dispersion solution containing a DMSO solvent to 0.25 wt% or less to prepare a silver nanowire solution, And spraying the dispersed silver nanowire solution onto the heated substrate with a high frequency dispersing spray nozzle.

More specifically, the high frequency dispersing spray using the ultrasonic spray deposition (USD) method has the advantage that since the nanowire uniform coating method itself breaks the agglomerate, the deposition becomes more uniform with the smooth surface, A thin coating film can be produced. Also, over time, silver nanowire particles precipitate and the composition of the coated thin film does not change.

More specifically, in the high-frequency dispersion spray according to an embodiment of the present invention, the frequency for uniform coating of the nanowires is effective from 170 kHz to 190 kHz.

When an electrode is manufactured using the high-frequency dispersion spray apparatus within the above-mentioned range, uniform thickness and composition of the thin film can be ensured and the physical properties and workability can be further improved.

In the silver nanowire uniform coating method using a high-frequency dispersion spray according to an embodiment of the present invention, the substrate may be heated to the boiling point or higher of the silver nanowire dispersion solvent.

More specifically, the process of raising the temperature of the substrate above the boiling point of the mixed solvent is a process for preventing the solution coated on the substrate from drying after the solution is dispersed to prevent the aggregation phenomenon, Uniformity can be remarkably improved, a large-area coating is possible, and a constant electric conductivity value can be obtained regardless of the position.

In the silver nanowire uniform coating method using a high-frequency dispersion spray according to an embodiment of the present invention, the heating temperature may be 190 ° C or higher.

More specifically, since the solvent DMSO remains after coating at a temperature of less than 190 캜, aggregation may occur, resulting in non-uniform surface after coating and deteriorating performance.

In the silver nanowire uniform coating method using a high frequency dispersing spray according to an embodiment of the present invention, the silver nanowire may have a diameter of 1 to 200 mu m and a diameter of 20 to 1,300 nm.

More specifically, when the aspect ratio of the silver nanowires is too large, the silver nanowires are hardly present in the form of wire and can be entangled like a thread, so the range described above is preferable.

In the silver nanowire uniform coating method using a high-frequency dispersion spray according to an embodiment of the present invention, the dispersion solution may be prepared by mixing 40 to 60 parts by weight of DMSO with respect to 50 parts by weight of ethanol.

More specifically, if the DMSO content is less than 40 parts by weight based on 50 parts by weight of ethanol, the improvement of surface uniformity is insignificant. If the DMSO content is more than 60 parts by weight, the electrical conductivity may be lowered, .

Therefore, the silver nanowire homogeneous coating method using the high frequency dispersing spray of the present invention has the advantage of improving the uniformity of the silver nanowire, thereby improving the performance and stability of the electrode, and improving the chemical resistance and durability.

In the silver nanowire uniform coating method using a high-frequency dispersion spray according to an embodiment of the present invention, the dispersion solution may contain a cellulose-based material as a stabilizer in a range of 0.5-1 weight per weight of the nanowire.

More specifically, in the silver nanowire uniform coating method using the high-frequency dispersion spray of the present invention, when the cellulose-based material is less than 0.5 per 1 weight of the nanowire, the function of the viscous agent for stabilizing the dispersion solution and the dispersion of silver nanowires It is not preferable because there is a problem that it can not be promoted. When the cellulose-based material is more than 1 part by weight of the silver nanowire, the electrical conductivity of the electrode formed through the coating is reduced.

In the silver nanowire uniform coating method using a high-frequency dispersion spray according to an embodiment of the present invention, the cellulose-based material may be selected from the group consisting of methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, methylethylcellulose, Carboxymethylcellulose, and hydroxypropylcellulose. ≪ Desc / Clms Page number 7 >

Accordingly, the present invention provides a silver nanowire thin film substrate coated on a substrate by the above method.

Also, the present invention provides a composition for uniform coating of silver nanowires using a high-frequency dispersion spray comprising 40 to 60 parts by weight of DMSO and 0.1 to 0.3 parts by weight of silver nanowires, based on 50 parts by weight of ethanol.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

The following physical properties were measured by the following methods.

1) Surface structure analysis

Optical microscopy (OM, Optical microscopy, Nikon, eclipse80i) was used to observe the formation of silver nanowire-coated thin films.

2) Surface uniformity

The surface uniformity of the microstructure of the silver nanowire-coated thin film was analyzed using a scanning electron microscope (SEM, JEOL LTD, JSM-6300). The size of the substrate used for the analysis was measured as 1 cm x 1 cm. Evaluation was made by the number of silver nanowire particles existing within a certain area, and X = no thin film formation, O = thin film formation, O: = thin film having more uniform surface was formed.

3) Electrical Conductivity Measurement

       The surface resistance per unit area was measured in terms of ohm / sq. Through a sheet resistance meter. The lower the value, the higher the electrical conductivity.

≪ Preparation Example 1 &

0.3 g of ethanol, 0.3 g of silver nano powder (manufactured by Nanopyxics), and 0.3 g of cellulose were mixed to prepare a silver nanowire coating composition. Spray the solution prepared from ultrasonic nozzle spray (flow rate: 16 ml / h, ultrasonic intensity 17 level, distance of separation 10 cm) at room temperature for 2 minutes on the substrate. The area of sprayed by SEM was measured and the uniformity was not observed.

≪ Preparation Example 2 &

Was prepared in the same manner as in Production Example 1, except that 0.2 g of nano powder (manufactured by Nanopyxics) and 0.2 g of a stabilizer (cellulose) were used.

≪ Preparation Example 3 &

Except that 0.1 g of nano powder (manufactured by Nanopyxics) and 0.1 g of a stabilizer (cellulose) were used.

≪ Preparation Example 4 &

0.2 g of silver nano powder (manufactured by Nanopyxics), and 0.2 g of a stabilizer (cellulose) were mixed to prepare a silver nanowire coating composition. Place the substrate on a hot plate and adjust the temperature to 70 ° C near the boiling point of ethanol. Spray the solution prepared with ultrasonic nozzle spray (flow rate: 16 ml / h, ultrasonic intensity 17 level, separation distance 10 cm) onto the substrate for 2 minutes . Measure the area sprayed with SEM and observe the uniformity.

≪ Production Example 5 &

Was prepared in the same manner as in Production Example 4 except that 0.1 g of nano powder (manufactured by Nanopyxics) and 0.1 g of a stabilizer (cellulose) were used.

Condition ethanol
(Parts by weight) Silver nano powder
(Parts by weight) cellulose (parts by weight) Substrate processing temperature (캜) Thin film formation
Whether Sheet resistance
(Ω / sq.) Production Example 1 100 0.3 0.3 Room temperature X - Production Example 2 100 0.2 0.2 Room temperature ○ 13.5 Production Example 3 100 0.1 0.1 Room temperature ○ 16.5 Production Example 4 100 0.2 0.2 70 ◎ 10.5 Production Example 5 100 0.1 0.1 70 ◎ 12.9

As shown in Table 1, it was confirmed that a thin film was formed in a coating composition containing silver nano powder at a concentration of 0.25 wt% or less. Also, it was confirmed that when the substrate treatment temperature was maintained at 70 캜, the aggregation phenomenon was further reduced and a uniform thin film was formed, and thus the sheet resistance value was decreased, thereby improving the electric conductivity. This is because the aggregation of the coating occurs because the coated solution is not dried immediately after spraying the solution. Therefore, the team confirmed that the method of treating the substrate with the temperature is more effective for the uniform coating as a whole. On the other hand, although ethanol was used as a solvent and the substrate treatment temperature was maintained at 70 캜, the sheet resistance value was rather high, so that other solvent conditions such as the following preparation examples were additionally performed.

Thus, coating thin films were formed by using acetone and DMSO as solvents having different boiling points, and the characteristics of the thin films were evaluated to obtain optimum coating conditions.

≪ Production Example 6 &

50 g of ethanol, 40 g of acetone, 0.2 g of silver nano powder (manufactured by Nanopyxics), and 0.2 g of cellulose were mixed to prepare a silver nanowire coating composition. Place the substrate on a hot plate and adjust the temperature to 70 ° C near the boiling point of ethanol. Spray the solution prepared with ultrasonic nozzle spray (flow rate: 16 ml / h, ultrasonic intensity 17 level, separation distance 10 cm) onto the substrate for 2 minutes . Measure the area sprayed with SEM and observe the uniformity.

≪ Production Example 7 >

(Manufactured by Nanopyxics) 0.1 g, and a stabilizer (cellulose) (0.1 g) were used in place of the above-prepared solution.

≪ Production Example 8 &

Except that 60 g of acetone was used.

< Production Example 9 >

60 g of acetone, 0.1 g of silver nano powder (manufactured by Nanopyxics), and 0.1 g of a stabilizer (cellulose) were used.

Condition ethanol
(Parts by weight) acetone
(Parts by weight) Silver nano powder
(Parts by weight) cellulose (parts by weight) Substrate processing temperature (캜) Thin film formation
Whether Sheet resistance
(Ω / sq.) Production Example 6 50 40 0.2 0.2 70 ○ 14.3 Production Example 7 50 40 0.1 0.1 70 ○ 15.4 Production Example 8 50 60 0.2 0.2 70 ○ 14.5 Production Example 9 50 60 0.1 0.1 70 ○ 16.4

As shown in Table 2, when acetone and ethanol were mixed and used as a solvent, they were coated in a circular dot form (see FIG. 5). Since acetone has a low boiling point, it appears to be coated with water droplets after drying rapidly after the solution has fallen onto the substrate. Further, in this case, it was confirmed that there was no remarkable effect in terms of electric conductivity. That is, when ethanol alone was used as a dispersion solvent, it was confirmed that it was coated more uniformly than using a dispersion solution in which acetone was mixed with ethanol. Then, another solvent instead of acetone was mixed with ethanol and used as a dispersion solvent.

&Lt; Production Example 10 &

Thus, a silver nanowire coating composition is prepared by mixing 50 g of ethanol, 30 g of DMSO, 0.2 g of silver nano powder (manufactured by Nanopyxics), and 0.2 g of cellulose. The substrate was placed on a hot plate and the temperature was adjusted to 190 ° C near the boiling point of DMSO. The solution was sprayed on the substrate for 2 minutes using an ultrasonic nozzle spray (flow rate: 16 ml / h, ultrasonic intensity 17 level, . Measure the area sprayed with SEM and observe the uniformity.

&Lt; Production Example 11 &

(Manufactured by Nanopyxics) 0.1 g, and a stabilizer (cellulose) 0.1 g were used in place of the nano-powder (manufactured by Nanopyxics).

&Lt; Production Example 12 &

Except that 40 g of DMSO was used.

&Lt; Preparation Example 13 &

Except that 40 g of DMSO, 0.1 g of silver nano powder (manufactured by Nanopyxics), and 0.1 g of a stabilizer (cellulose) were used.

&Lt; Production Example 14 >

Except that 60 g of DMSO was used.

&Lt; Production Example 15 >

Except that 60 g of DMSO, 0.1 g of silver nano powder (manufactured by Nanopyxics), and 0.1 g of a stabilizer (cellulose) were used.

&Lt; Production Example 16 &

Except that 80 g of DMSO was used.

<Production Example 17>

Except that 80 g of DMSO, 0.1 g of silver nano powder (manufactured by Nanopyxics), and 0.1 g of a stabilizer (cellulose) were used.

ethanol
(Parts by weight) DMSO
(Parts by weight) Silver nano powder
(Parts by weight) cellulose (parts by weight) Substrate processing temperature (캜) Thin film formation
Whether Sheet resistance
(Ω / sq.) Production Example 10 50 30 0.2 0.2 190 ○ 4.5 Production Example 11 50 30 0.1 0.1 190 ○ 6.1 Production Example 12 50 40 0.2 0.2 190 ◎ 5.1 Production Example 13 50 40 0.1 0.1 190 ◎ 8.1 Production Example 14 50 60 0.2 0.2 190 ◎ 5.4 Production Example 15 50 60 0.1 0.1 190 ◎ 8.4 Production Example 16 50 80 0.2 0.2 190 ○ 6.1 Production Example 17 50 80 0,1 0.2 190 ○ 9.6

As shown in Table 3, when the ethanol and DMSO are mixed as a solvent, the sheet resistance value is remarkably lowered. Particularly, in Production Examples 12 to 15, when 40 to 60 parts by weight of DMSO is mixed with 50 parts by weight of ethanol as a dispersion solution, it is confirmed that the electrical conductivity is improved and the coating film is formed finer and uniformly. Therefore, the silver nanowire uniform coating method using a high-frequency dispersion spray in which the silver nanowire solution is prepared by dispersing silver nanowires in a dispersion solution containing DMSO solvent in an amount of not more than 0.25 wt% And thus it has an excellent performance and stability, and additionally has an advantage of increasing chemical resistance and durability.

Claims (9)

A silver nanowire solution is prepared by dispersing silver nanowires in a dispersion solution containing a DMSO (dimethyl sulfoxide) solvent in an amount of 0.25 wt% or less,
Heating the substrate on which the silver nanowire is to be coated,
And spraying the dispersed silver nanowire solution onto the heated substrate with a high frequency dispersion spray nozzle. The method according to claim 1,
Wherein the substrate is heated to a temperature higher than the boiling point of the silver nanowire dispersion solvent. 3. The method of claim 2,
Wherein the heating temperature is 190 占 폚 or higher. The method according to claim 1,
Wherein the silver nanowire has a length of 1 m to 200 m and a diameter of 20 nm to 1,300 nm. The method according to claim 1,
Wherein the dispersion solution is prepared by mixing 40 to 60 parts by weight of DMSO with respect to 50 parts by weight of ethanol. 6. The method of claim 5,
Wherein the dispersion solution contains a cellulose-based material as a stabilizer in a range of 0.5-1 weight per weight of the nanowire. The method according to claim 6,
Wherein the cellulosic material is selected from the group consisting of methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, methylethylcellulose, carboxymethylcellulose, and hydroxypropylcellulose. A method for uniformly coating silver nanowires using. A silver nanowire thin film substrate coated on a substrate by the method of any one of claims 1 to 6. Wherein the silver nanowire comprises 40 to 60 parts by weight of DMSO and 0.1 to 0.3 parts by weight of silver nanowires, based on 50 parts by weight of ethanol.

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