Prise winners list

Groundbreaking 'oil-based' mold release agent for 'electrostatic coating' in die-casting. This agent is highly-efficient, economical and eco-friendly.

Minato-ward, Tokyo
Aoki Science Institute Co., Ltd.
Other award winners
Masanao Kobayashi, Toshiaki Shimizu
Recommended by
Togawa Koji

Komatsubara, Hiroaki  (39)
Research and Development Dept.
Chief researcher

We made a success because we flexibly doubted the common practice in the business field forty years ago

In die-casting (manufacturing method, in which melted metal is flowed into a mold and cooled to manufacture a product) of such products as an engine block, it was a common practice to use a water-soluble mold release agent to release a product from the mold surface. However, this company doubted that common practice and developed a new oil-based mold release agent. By using it, they could reduce the amount of used agent to 1/1000 compared with the conventional one, did not need to treat wastewater any longer and remove water by air blowing, and could reduce their working time significantly. The new release agent extended the life span of mold (20 times longer at maximum) and reduced the percent defective and energy cost. The new agent is very economical and used by major carmakers and other manufacturers, contributing to the preservation of environment by reducing CO2 emission.


It seemed wasteful to use a large quantity of water-soluble mold release agent

Die-casting is used to manufacture many parts such as a crankcase and cylinder block for an automobile engine. In die-casting, metals such as aluminum that is melted at high temperature are poured into a mold and cooled in it to manufacture a product. This method reminds us of "Taiyaki" (fish-shaped pancake). In baking Taiyakis, cooking oil is applied to the interior of mold so that they are not stuck to the bottom. Likewise, in die-casting, a mold release agent (oil) is applied to the interior of mold so that products can be released from the mold easily. Aoki Science Institute Co., Ltd. manufactures such mold release agent, lubricant, etc. 
"In the old days, oil-based mold release agents were used, but they easily caught fire when they were applied to a heated metal. Therefore people have been using water-soluble agents commonly since forty years ago."
Even a water-soluble mold release agent contains a slight amount of oil because, without oil, products cannot be released clearly from a mold. When a water-soluble agent is applied to a heated mold, the water evaporates and the oil remains.
In reality, things are not so easy. What happens when water is dropped on a heated frying pan? Usually water sizzles and evaporates. However, on a very hot metal, water forms balls, the water balls roll on the surface and do not evaporate (Leidenfrost phenomenon). The temperature of melted aluminum is about 650C and that of mold, into which it is poured, becomes 300 to 400C. Therefore when a water-soluble mold agent is applied to such mold, the Leidenfrost phenomenon occurs in the mold, the oil cannot adhere to the surface and the material is stuck to the surface.
"A large quantity of mold release agent was used to cool a mold to prevent this phenomenon, and this method was a common practice in the past forty years. However, we, people in a manufacturing facility, began to think that it was very ineffective to pour a large quantity of water-soluble agent to a mold."
Doubting the common practice is the first step toward an invention. We thought that since our goal was to apply oil to the mold surface, we had to apply oil to it from the very beginning. We found that we only had to use a solvent that did not catch fire. 
"Cool the mold whenever we cast a metal" was the common practice in our business field. However, the mold was cooled to evaporate the water in a mold release agent and form an oil film on the mold surface. If no water was contained, there was no need to cool the mold. 
This company started research of oil-based mold release agent in 2004 and completed a new product next year. The new oil-based agent had surprisingly many advantages.
"Quantity of used mold release agent was reduced to 1/1000 because there was no need to cool the mold surface anymore, and it was no more necessary to treat a large quantity of wastewater. Wok time was reduced by 10% because it was no more necessary to remove the remaining water from the mold surface by air blowing, and there was no defective product caused by remaining water. In addition, the life span of mold was extended"
Why could the life span of mold be extended? In the conventional method, whenever casting was performed, the mold was heated and cooled suddenly and so cracks were caused when casting was performed about 20000 times. In the new oil-based mold release agent, however, the change of temperature on the mold surface was much smaller and so the life span was extended.

In development of the second-generation product, the disadvantage of the first-generation product was eliminated in a new idea contrary to the conventional one

The new oil-based mold release agent had one disadvantage while it had many advantages as shown above. Since the quantity of agent applied was drastically reduced, the agent could not be sprayed to every corner of a mold of complicated shape.
"We thought that we should use "electrostatic coating", the technology used in the coating industry, to solve this problem. If a mold release agent was electrically-charged, sprayed gently and adhered to the mold surface by static electricity, even parts, which could not be coated by spray, could be coated."
However, the oil-based mold release could not be electrically charged because it was almost an insulator. Therefore we had the oil-based mold release agent contain a slight quantity of water and electrically charged it by applying high voltage when spraying it. The idea of this method was just contrary to that of the conventional one, in which a slight quantity of oil was contained in the water solution. 
Thus we completed the second-generation product in Sept. 2007. The first-generation product is used by more than one hundred companies including carmakers such as Toyota and Honda, and sales of the second-generation product is increasing gradually. 
"We are still testing how long the life span of mold can be extended, but some customers say, "We will be able to use our present mold without replacing it till manufacturing of its products is terminated."
"Mold release agent", which ordinary people do not know, is greatly contributing to strengthen the competitiveness of Japanese manufacturers.

Aoki Science Institute Co., Ltd.

Feb. 1927
40 million yen
19 (as of Dec. 2009)
Brief information:
The company manufactures and sells "Lubrolene" brand highly-efficient engine oil and gear oil, mold release agent for die-casting, lubricant and cutting oil.

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The can (light-blue) on the right contains the firs-generation mold release agent and the can (green) on the left contains the second-generation agent. The conventional agent was diluted by 50 to 100 times in water before use.


About 60-thousand voltage is applied at the tip of spry gun to electrically charge a slight amount of water that is contained in the oil-based mold release agent.


By spraying and distributing it gently, the mold release agent is flowed into every corner of mold.