Toray Advanced Film Co., Ltd. (head office: Chuo-ku, Tokyo; President: SusumuYamaguchi; hereinafter referred to as “the Company”) today announced that it hassucceeded in developing a silver nano-wire based transparent conductive filmwith the world’s best transparency and conductivity -light transmittance of 90%or above and surface resistivity^*1, which is a measure ofconductivity, between 150 and 250 Ω/sq- using wet coating method. The materialalso boasts superior flexibility, natural coloration, durability andworkability, and the Company expects to begin its mass production in the nearfuture.

Transparent conductive films are generally ITO films^*2 by use ofvapor deposition or sputtering methods, making them not much suitable forbending as they are thin and brittle inorganic material, and they sometimesaffect the flexibility of the final product. Furthermore, the primary rawmaterial Indium being a rare metal, there is also the issue of depletion ofresources. On the other hand, wet coating films using organic conductingmaterials, while superior in flexibility tend to be susceptible todiscoloration^*3 when conductivity is improved. They also have issueson durability under high heat and higher moisture circumstance though someproducts using such materials are available in the market. At the same time, intouch panel and display applications, it is necessary to not only havedurability and reliability but also compatibility with pattern processing andother peripheral technologies without losing optical characteristics.

Against this background, the Company recently entered into a strategicpartnership with Cambrios Technologies Corporation (head office: Sunnyvale,California; CEO: Michael Knapp), a U.S.-based electronic materials manufacturer,to develop a new product that addresses the above issues by bringing togetherhigh transparency, high conductivity nanowire ink technology of Cambrios withthe Company’s superior film processing technology.

Key technological points of the transparent conductive film developed thistime using silver nanowire ink are as follows: (1) nano-level coating thicknesscontrol technology, (2) wet-method multilayer laminating technology, and (3)product design proposals that suit the fabrication process of the user. Theproduct is considered better suited for mass production in comparison with ITOfilms which require sputtering or other such vacuum process. Also, given itssuperior flexibility and invisible patterning properties^*4 inaddition to high transparency and conductivity, the new film is expected to findapplication in touch panels used in cellular phones, smart phones and tabletPCs. The material can also address the need for lower resistance required bylarger-sized touch panels and therefore the Company expects it to contribute tothe display technology revolution in the future. Going forward, the Companyhopes the film would eventually be used in 3-D touch panels, solar cells andorganic EL electrodes.

The Company intends to further grow its touch panel-related business centeredon business expansion of transparent conductive materials widely used in smartphones and tablet PCs.

The Company will display the new products at the 2^ndHighly-functional Film Technology Expo to be held at the Tokyo Big Sight Japanfrom April 13 (Wed) to April 15 (Fri), 2011.

[Notes]

^*1　Surface resistivity
Surface resistivity is one of theyardsticks for measuring antistatic performance (or conductivity). It denotesthe resistance per unit area and is measured in Ohms per square (Ω/sq). As longas the sample being measured is square, the surface resistivity will be the sameregardless of the size of the sample (e.g. the value is same for1mm², 1 m² or 1 km²).

^*2　ITO
Indium tin oxide, or ITO, is a type of inorganiccompositions with transparency and conductivity, used as a primer afternano-atomization and in sputtering-based ITO films.

^*3　coloration
Organic conducting agents are generally prone tospecific coloration. While coloration is barely noticeable in thin films, thethicker the films are made to boost conductivity, the more prominent it becomes.For example, in the case of polythiophene series the color becomes dark blue andfor polypyrrole it becomes dark brown.

^*4　Invisible patterning properties
When using conductive filmsin touch panels for smart phones, etc. it is necessary to carry out patterning.This patterning has been found to generate patterns with differences in degreeof transmission and reflection, coloration and other optical properties. It isnecessary to keep these differences in optical properties to the minimum inorder to carry out patterning that is invisible to human eyes.

Source: http://www.toray.com/news/film/nr110408.html