SDK Starts to Mass-Produce Transparent Conductive Ink for Electronics

SDK and Microwave Chemical Jointly Develops New Industrial Technology


Showa Denko K.K. (SDK) (TOKYO:4004) and Microwave Chemical Co., Ltd. (Microwave Chemical) have jointly developed a technology to mass produce silver nanowire ink that forms transparent electro-conductive patterns through utilization of printing technology.


In 2012, SDK developed printable silver nanowire ink to form transparent electro-conductive patterns on flexible films jointly with Professor Katsuaki Suganuma of National University Corporation Osaka University*.  In order to form conductive patterns with high transparency and high electro-conductivity, it is very important to raise the aspect ratio (ratio of length to diameter) of silver nanowire, a metallic nanomaterial.  Since the conventional method to synthesize silver nanowires tends to allow silver nanoparticles to have crystal growth on all of their surfaces, it is not easy to have silver nanoparticles grow to be nanowires.  Therefore, establishment of technology that realizes stable mass production of silver nanowires was a problem.


This time, SDK and Microwave Chemical jointly developed a method to synthesize silver nanowires with microwave heating, a technology to selectively heat materials.  If microwave is irradiated on silver nanoparticles in their growth process to be silver nanowires, only the growing ends absorb energy and generate heat.  In order to utilize this property, we made silver nanoparticles selectively absorb capping agent that interferes crystal growth, and successfully produced slender nanowires with great efficiency.


After printing, silver nanowire ink expresses electro-conductivity after application of Photonic CuringTM process technology**.  This time, SDK has developed undercoating agent that enhances closeness of adhesion of silver nanowire patterns to the surfaces of substrates or films and minimizes damage to substrates or films caused by curing.  SDK is also developing overcoating agent that prevents deterioration of silver nanowires which are said to be weak against heat.  SDK will start to offer samples of the ink and related materials in July 2015***.


SDK will exhibit a touch sensor and a 7-inch touch panel made with the ink and related materials on experimental basis at the SDK’s booth in “JPCA Show 2015” which is to be held at Tokyo Big Sight from June 3 to 5, 2015.



* SDK’s news release on October 1, 2011: “SDK Develops Printable Conductive Inks for Electronics”

** SDK’s news release on April 11, 2011: “SDK and NovaCentrix to Cooperate in Printed Electronics”

*** This product is under development, and the specifications indicated here are subject to change.



Media contact:

Showa Denko K.K.  Public Relations Office (Phone: 81-3-5470-3235)

Microwave Chemical Co., Ltd.  Administrative Department (Phone: 81-6-6170-7595)




Outline of Showa Denko K.K.

Head office: Minato-ku, Tokyo

Established in June 1939

Representative Director, President: Hideo Ichikawa

Capital: \140,564 million

Number of employees: 10,577 (Consolidated, as of December 31, 2014)

Scope of business: R&D, production and sales of petrochemicals, chemicals, electronics, inorganics, aluminum products, etc.


Outline of Microwave Chemical Co., Ltd.

Microwave Chemical was established as a venture company originated from National University Corporation Osaka University.  Making use of microwave technology, Microwave Chemical aims to bring about revolutions in manufacturing processes of chemical products and promote energy conservation in factories worldwide.  Setting “Change the way we produce fuel and chemicals.” as its basic concept, Microwave Chemicals starts up and runs many joint projects with companies, laboratories, government institutions, and other organizations engaged in manufacturing, and promotes practical use and industrial application of innovative fruits of these projects.


Head office: Suita-city, Osaka

Established in August 2007

Representative Director, President: Iwao Yoshino

Capital: \2,038 million (including a capital reserve of \1,012 million)

Number of employees: 39 (As of May 31, 2014)

Scope of business: Development and offering of manufacturing methods making use of microwave technologies, especially in the fields of chemical industry and energy industry.  R&D on chemical manufacturing processes utilizing microwave technology, and engineering these processes.  Manufacturing products through these processes and selling these products.  Joint operation with other entities.  Licensing intellectual properties.

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Contact Number


〒565-0871 Photonics Center 5F, 2-1 Yamadaoka, Suita, Osaka
FAX +81-6-6170-7596