High refractive index nanoparticles: ZIRCOSTAR™ 

The development of Nippon Shokubai 's zirconia nanoparticle dispersion "ZIRCOSTAR™" was a series of hardships

Among Nippon Shokubai 's fine particle product group, which is one of its flagship products, there are four products that include "star" in their names: EPOSTAR™, SEAHOSTAR™, ZIRCOSTAR™, and SOLIOSTAR™.

The road to commercializing one of these products, ZIRCOSTAR™, was one filled with difficulties, to the point where the person in charge couldn't help but mutter, "There was never an easy moment; it was always a struggle..."

The initial development stages ZIRCOSTAR™ also went smoothly.

In the early 2000s, product development using nanomaterials such as carbon nanotubes became popular, and Mr. Y, who was transferred from research to the business planning department, was researching nanocomposite materials (composite materials that combine nanomaterials with resins, etc.) in order to plan new products.

Mr. Y thinks, "In some cases we purchase nanoparticles from outside and mix them into our own resins, but wouldn't it be better to synthesize expensive nanoparticles in-house? Wouldn't that expand our business even more?"

It matches perfectly with the technology of the Catalyst Research Institute...

Mr. Y searched for a research department within the company that could synthesize nanoparticles, and approached the director of the Catalyst Research Institute, saying, "I think we can synthesize nanoparticles using the technology we use to synthesize catalysts."

The Catalyst Research Institute agreed with Y's proposal and began investigating various nanoparticles. H and Y, who were the main researchers working on nanoparticle synthesis, decided to try their hand at making zirconia (zirconium oxide) nanoparticles, which can increase the refractive index of optical materials.

Looking back on that time, Mr. H said, "At that time, I had reached a dead end in my research topic, but I was interested in nanoparticles, so I spent about two years researching literature and trying out various technologies through trial and error. I remembered that a paper I was looking at at the time contained a technology that seemed useful."

Overcoming the barrier of wastewater treatment during the scale-up stage...

When they introduced the zirconia nanoparticles they had synthesized in the lab to an optical materials manufacturer, they received a great deal of interest and a positive response. They proposed scaling up the product in order to commercialize it.

During the scale-up stage, the mission given to Mr. O, the researcher who received the theme from Mr. H, was to review the manufacturing process.

"When we consulted the production technology department about scaling up, we were told that the amount of wastewater was so large that the cost of treating it was higher than the cost of the particles themselves, and that, frankly, it was not worth discussing."

"We reviewed each step of the nanoparticle synthesis process that Mr. H had created, and we gradually reduced the amount of waste liquid. During this time, our technology was being touted as a key material within the Research Division, and we were under a lot of pressure to patent the manufacturing technology we had developed." (Mr. O)

However, after careful consideration, we were finally able to come up with a process that was at a level where we could carry out manufacturing, and we were finally at the stage of conducting a sample work campaign outside the company.

Here's a little anecdote.

"We thought we were finally ready to provide samples widely to outside parties and have a variety of customers evaluate them. However, at a report meeting within the Research Division, the head of the division instructed us, "This developed product is a key material, so we need to take good care of it. Before taking it outside the company, make sure you develop an application product in-house. Don't send it outside the company until our internal evaluation is complete."

Mr. Y recalls, "We were adjusting the evaluations within each department within the company, and even when we received good results in the internal evaluation, it would take a long time from there, and I became anxious that if we continued like this we would fall behind our competitors' products. After several months of this, I finally lost my patience during a meeting within the Research Headquarters, and said to the head of the Research Headquarters, 'Enough is enough. If we carry on like this, our hard-earned technology will be buried within the company. Please give us permission to conduct sample work outside the company.' I got a bit of a scolding from the higher-ups at the headquarters, but in the end we were able to conduct sample work outside the company, which was a relief."

If only six months had passed... we would have been at the mercy of the Lehman Shock.

Thus, the situation somehow became such that sample work could be done outside the company, and Mr. T, who was in charge of research at the time, said, "I volunteered and was put in charge of zirconia nanoparticles. We highlighted the transparency and high refractive index, and received a good response from major companies. We also received feedback that the performance evaluation was favorable, and hopes grew within the company that we might be adopted."

However, just as this was happening, the Lehman Shock occurred in 2008. With profits falling at every company, there was a need to reduce product development costs.

"I thought it was strange that they suddenly stopped contacting us after we had received so many requests for samples for the next scale-up. When I visited them, they told me, 'Due to the impact of the Lehman Shock, we needed to reduce development costs, so we decided to prioritize commercialization using zirconia particles from another company that was ahead of us. The price was low and the performance was good, but we were no longer able to consider the two companies at the same time, so unfortunately we will put consideration of your particles on hold.'"

"If only we had been able to release the sample six months earlier... I really regret it." (Mr. T)

We tried again with a new purpose, but it didn't lead to adoption...

Mr. T and his team pulled themselves together and started to develop a new application. They were considering dispersing zirconia nanoparticles in a resin to improve the refractive index. Although they had difficulty dispersing in a resin different from the ones they had been considering, they managed to create a sample.

The results were recognized and the idea was nominated for the Invention Planning Award, which is given to outstanding inventions in the research department. However, despite hopes of it being adopted within the Research Department, the idea proved difficult to solve, and the idea was put on hold as a new application.

The light is shining for adoption in display applications

Although samples were worked on for various applications, the characteristics did not seem to match, and discussions of changing or eliminating research themes began to arise within the headquarters.

In the midst of all this, we received a request to use zirconia nanoparticles for display applications. Although there were several obstacles, we worked together to overcome them and finally saw the light at the end of the tunnel.

The head of the Research Headquarters also made a powerful comment: "It's been a long and difficult journey, but now we can compete. I'm thrilled that we've come this far!"

"From this point on, the project's progress accelerated and we were able to secure employment." (Mr. T)

The ability to effectively bend light by taking advantage of the high refractive index of zirconia nanoparticles was appreciated, and the decision was made to use it as a material for optical films for LCD displays.

10 years of hard work. Overcoming hardships that are etched in our memories to bring the product to market

"The first ZIRCOSTAR™ was commercialized in 2015," says Mr. T, a person who has been involved with the product for a long time. Mr. T has a clear memory of what happened in what year.

Further evolution of nanoparticle technology

In recognition of its achievements, the zirconia nanoparticle dispersion ZIRCOSTAR™ was awarded the Chemical Technology Award by the Kinki Chemical Association in 2019.

In addition to being used as an optical material, ZIRCOSTAR™ is also used in dental materials due to its ability to show up on X-rays. Although ZIRCOSTAR™ was commercialized after many hardships, it did not grow smoothly even after commercialization. Although it was sometimes exposed to fierce competition, ZIRCOSTAR™ has continued to evolve through repeated improvements by researchers in order to solve new problems for customers every day, up until the present day.