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AdNano ITO Nanostructured Indium Tin Oxide, Applications, Properties and Product Availability, Supplier Data By Degussa

Topics Covered

Background

Applications

Product Properties

Powder

Dispersion

Lacquer

Packaging and Storage

Background

Coatings on glass or plastics containing AdNano® ITO are highly transparent and feature electrical conductivity, antistatic properties and IR absorption. These properties are additionally complimented by scratch resistance of the coatings. Such characteristics open up numerous potential applications, for example, in optoelectronic components such as flat panel displays. Other fields of application are antistatic coatings for aircraft or automobile windows, and heat absorbing transparent coatings.

Degussa offers its know-how for the adaptation of available formulations to different systems. Surface modification and the provision of test dispersions facilitate rapid testing of the suitability of AdNano® ITO in a given application in the first developmental stage.

AdNano® ITO is available as:

•        VP AdNano® ITO TC8 Powder form for antistatic applications

•        VP AdNano® ITO IR5 Powder form for IR applications

•        VP AdNano® ITO DE 20 % ITO dispersion in ethanol = Standard recommendation for electrically conductive coatings, antistatic applications

•        VP AdNano® ITO LUV1 Transparent scratch-resistant antistatic coating, UV-curing

•        Test dispersions of VP AdNano® ITO in water and /or solvents upon request

Applications

Transparent antistatic coatings and films for flat panel displays and clean-room window panes. Antistatic transparent surfaces have gained increasing interest in recent years. The use of films and plastic glazing is increasingly replacing typical glass applications. Due to a certain degree of surface conductivity, glasses experience few problems with electrostatic charges. Plastics, however, become heavily charged in dry or air-conditioned rooms. As a result, discharges may occur that can disrupt electronic components or displays.

Considerably more dust contamination of the plastic surfaces is also observed. Additionally, standards for optical transparency and clarity are increasing with the widespread use of plastic films on TV screens and displays. The outer film facing the viewer of displays is often treated with rapidly degrading antistatic chemicals after installation.

Light-sensitive colored conductive polymers that result in an antistatic surface are also an alternative, however they can cause a distorted color perception. The use of coating formulations based on AdNano® ITO products does not have these drawbacks. They are stable and exhibit high grade functionality. Coatings with the new antistatic transparent AdNano® ITO coating formulations enable PET, TAC, PMMA and other substrates to be provided with three attractive functions in a single step.

•        Antistatic properties (105 -108 Ω/sq.) together with high transparency, color fastness and high UV resistance

•        High mechanical stability and scratch resistance (up to 5H)

•        High chemical resistance

The coating is provided at low cost on conventional film coating systems. With this coating system, Degussa provides customers with the advantages resulting from many years of intensive research; maximum transparency, scratch resistance and antistatic properties with minimum ITO use.

Figure 1 shows an example of a UV-curing acrylic coating on a Plexiglas® sheet featuring a transparency of 96 % (BYK-Gardener), a haze of 0.5% and a surface resistivity of 108 Ω/sq. This coating passes the steel wool scratch test.

AZoNano - The A to Z of Nanotechnology - Coating on Plexiglas® sheet

Figure 1. Coating on Plexiglas® sheet

In addition to the pure powder, AdNano® ITO is also available predispersed in water or solvents, for custom development of coating systems.

Nano structured ITO is further processed into heat or UV-cured coatings in aqueous or solvent based dispersions which are applied in conventional coating processes (blade, spray, dipping, pouring or spin coating). There is a great deal of latitude in the choice of component geometries that can be coated, affording a wide range of possibilities in fields of application such as antistatic scratch proofing of aircraft windows, safety goggles and motorcycle helmets.

Figure 2. Relationship between pencil hardness of the surface and electrical surface resistivity using AdNano® LUV coatings

Table 1. Parameters of LUV coatings

Properties

VP AdNano® ITO LUV 1

VP AdNano® ITO LUV 2

Surface Resistivity[Ω/sq.]

108

105

Pencil Hardness on PET

Up to 3H

Up to 2H

Pencil Hardness on PMMA

Up to 5H

Up to 4H

Pencil Hardness on TAC

Up to 3H

Up to 2H

Delta Haze [%]

< 1

< 1

Delta Transmittance [%]

> 95

> 95

Chemical resistance

Good

Good

Instruction sheets are available for the use of ITO containing coatings or dispersions. Acrylic coatings have been prepared, for example, using VP AdNano® ITO DE, a 20 % ethanolic dispersion with VP AdNano® ITO TC8.The acrylic coating was applied with 12μm blade and cured with a UV lamp under an inert gas atmosphere. In this instance, the ITO concentration is 20 wt % in the solid coating.

Transparent IR-absorbing coatings for laser marking and for heat-absorbing films for windows in automobiles and buildings Incorporated in a wide variety of transparent plastics and clear coatings, VP AdNano® ITO IR5 permits selective absorption of IR laser light and thermal radiation invisible to the human eye thanks to the combination of optical transparency and IR absorption.

With sufficient intensity, the energy of the laser beam can be utilized to selectively heat, melt or carbonize the polymeric matrix. This provides versatile potential uses: rapid inside marking of transparent plastics, selective engraving or laser induced welding of transparent plastics.

The application of VP AdNano® ITO IR5 in transparent film coatings makes it possible to provide glass installed in buildings or vehicles with better solar absorption properties while maintaining optical transparency (no darkening). Figure 3 shows the infrared transmission spectrum of a typical coating on Plexiglas in comparison to the uncoated material.

AZoNano - The A to Z of Nanotechnology - IR transmission spectra of a coated and uncoated PMMA sheet

Figure 3. IR transmission spectra of a coated and uncoated PMMA sheet

Table 2. The measured heat protection indicators show that providing a window with a VP AdNano® ITO IR5 film can compete with modern solar protection glass windows

Transmittance visible range (coating + substrate) [%]

88

Haze (coating + substrate) [%]

< 1

SKZ value (=Transmittance/g-value)

1.23

Global Radiation Transmitted τe *1 [%]

54

Global Radiation Reflected ρe *2 [%]

7

*1 Measurement method: DIN EN 410, comparable to TSET ASTM E 424-71

*2 Measurement method: DIN EN 410, comparable to TSER ASTM E 424-71

Product Properties

Powder

AdNano® ITO in pure form is a fine blue powder. The color is an indicator of the quality of the product. Yellow or gray ITO has a distinctly lower electrical conductivity. At temperatures over 200° C in the presence of oxygen, AdNano® ITO loses its blue color and also its conductivity. Table 3 shows some typical values of the product in powder form. When processing and handling the material, all of the usual precautions for fine powders must be taken and the instructions in the safety data sheet must be adhered to.

Table 3. Powder properties, typical values

Property

Typical Value

Color

blue

Tapped density (g/l)

ca. 900

Specific surface area BET (m2/g)

45 +- 15

Minimum electrical resistivity (Ωcm)

1-2

ITO content

> 99.999 %

Dispersion

All AdNano® ITO products in powder form are particularly easy to disperse with the use of high shear force, allowing for excellent transparency of the product.

AZoNano - The A to Z of Nanotechnology - TEM photo of a cross section of AdNano® ITO LUV1-coating on a PMMA film

Figure 4. TEM photo of a cross section of AdNano® ITO LUV1-coating on a PMMA film

AZoNano - The A to Z of Nanotechnology - Particle size distribution of AdNano® ITO in dispersion

Figure 5. Particle size distribution of AdNano® ITO in dispersion

Lacquer

A UV curable solvent based lacquer system with nano structured Indium Tin Oxide is available for the production of electrical dissipative, antistatic, transparent and scratch resistant coatings on polymer substrates such as Plexiglas® (PMMA), PET or TAC.

Packaging and Storage

AdNano® ITO (powder) samples are delivered in 50g glass bottles. Packaging for larger amounts and containers is available upon request. Dispersions and coating material are also delivered in glass bottles. It is recommended to store the product in a dry place and away from heat and frost and to process it within six months after production. Slight sedimentation is normal and can be eliminated by shaking or stirring.

 

For more information on this source please visit Degussa.

 

Date Added: Jul 1, 2006 | Updated: Jun 11, 2013
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