PRINTRONICS

Producing Organic Conductive Inks
Through a Simple Synthesis Method

Paper Electronics Research AssociationT

he Paper Electronics Research Association,
whose members include those from universities, corporations, and creative agencies, held its
20th Technology Research Presentation Conferencein Tokyo this past September. In aiming to develop
new applications using the characteristics of printing
technology and paper, each event hosts company
representatives, creators, and university researchers
as speakers. During the most recent event, Professor Shuichi Maeda of Tokai University and Chairof the Department of Optical and Imaging Scienceand Technology, Tsuguo Yanai of Paper Art Studio,and Kenji Takasaki from MEIKO PRINTING CO., LTD.,
took the stage.

Synthesizing Hybrid InorganicOrganic Conductive Inks

certain chemicals. The inks also remain stable after printing
and drying, so do not peel oﬀ the paper. According to Professor Maeda, the greatest advantage of this simple method
is its safety and the ease with which anyone can replicate it.
On the other hand, silica is an insulator, so its low conductivity is not suited to certain applications. In fact, polypyrrole silica has a conductivity that is a magnitude or twolower than that of pure polypyrrole. Hybridizing the inks withtin oxide, however, increases the conductivity to the samelevel or higher than that of standard polypyrrole.
Following this explanation, Professor Maeda introduced
the use of these inks in applications like antigen-antibody
reaction dyes and electronic paper. According to Professor
Maeda, some areas of Europe already use these inks as antigen-antibody reaction dyes in pregnancy tests and AIDS
tests.

The basic method for synthesizing organic conductive inks

Paper Texture and Artworkthat disperse stably in water relies on hybridizing organic

Tsuguo Yanai of Paper Art Studio has made his own paper

conductive polymers (polypyrrole, etc.) and inorganic parti-

since the mid-1980s, which he has used to create traditionalcles (silica, etc.) at the nano-scale. Professor Shuichi Maeda

paper crafts and works of art. This work initially stemmedof Tokai University explained this method using the example

from his desire to make original paper and print this withof polypyrrole silica as part of his talk. In this case, a sy-engraved copperplates. During the event, he discussed hisringe is used to introduce pyrrole to a solution containing

experience thus far using videos and photos of his artistic

dissolved iron chloride and colloid silica. In doing so, theprocess.

solution steadily converts to a black ink over the course of

As Mr. Yanai explains, traditional materials like stone,

30 seconds to around one minute. The ink particles range

wood, metal, and clay are often used as a medium in thefrom 100 to 200 nm, and do not precipitate out after they

art world, whereas paper has only served as a supporting

disperse. As such, the inks are stable, remain unchanged

material that is either drawn on or printed, for example. In

even after a year, and absorb more light than dyes used inresponse, he began presenting works of art from his de-58

Convertech International

November / December 2019sire to use paper as an expressive medium that would standreturned to his father’s company after his father began con-alongside materials like stone and metal. In one example

sidering shutting down the business, at which time he start-

titled “Relic,” which was on display at one of his exhibitions

ed searching for other businesses based on the remnants ofin September, Mr. Yanai recreated the faces of historical ﬁg-

his more exciting life in Tokyo. In response to the boom inures through the paper making process itself. In this case,letterpress printing that was occurring at this time in Tokyo,

black dyed raw paper materials are washed over a mesh to

he gathered together the second and third generations ofproduce the images.

managers at letterpress printing companies in Osaka andOverseas Interest in Japanese
Letterpress Printing
Kenji Takasaki succeeded his father as president of MEIKO

created the KANSAI MOVABLE TYPE CLUB. This organization holds letterpress printing events and has been coveredby the media, both of which have rapidly accelerated themomentum of letterpress printing in Osaka.

PRINTING, a movable type (letterpress) printing company

The 12 plate, 24 color Ukiyo-e-like letterpress prints thatbased in Osaka with 70 years of history, some 10 years ago.

Mr. Takasaki makes have also attracted interest from over-Having had absolutely no interest in printing earlier in his life,seas. Similarly, he also uses letterpress printing together

before taking over the company Mr. Takasaki established anwith gold foil discarded by gold foil companies, which, ac-cross-industry exchange group when he was still in his 20s,cording to Mr. Takasaki, have become very popular in Tai-and became involved with various businesses, including in-

wan and China. In addition to printing, Mr. Takasaki is also

ternet cafes, commemorative school magazine printing, for-developing new businesses through collaborations with thetune telling, and melon bread food truck sales. Mr. Takasaki

presidents and owners of companies in other industries.

November / December 2019

Convertech International59