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Attained the antibacterial activity value 2.0 that the medical front requests!

Antibacterial coating

*Antibacterial activity value of 4.6 has been attained in actual measurement tests.

Attained antibacterial efficacy (after 24 hours) of 99.9% or higher and passed the 100,000-time keying anti-wear test!

The technology was adopted for the Support Industry business by The Ministry of Economy, Trade and Industry in 2015

The project team, “Development of a painting technology that optimizes antibacterial performances by forming a sub-μm functional surface” project team (KUBOI Coating Works Co., Ltd., Tokyo Metropolitan University, MEIJI AIR COMPRESSOR MFG. CO., LTD., and TAMA-TLO) has been developing with the support of  “Support Industry business (tactical base technology sophistication support business)” promoted by the Ministry of Economy, Trade and Industry has succeeded in development of a highly functional paint film that meets the antibacterial standard “antibacterial activity value 2 or higher (1% or lower to the average value of the logarithmic value of viable bacteria counts after 24-hour cultivation of non-processed testing pieces) required by a lot of medical institutions and which film passed the anti-wear test of 100,000-time keying using an artificial finger.

Medical standard for antibacterial performance different from ordinary standard

The “antibacterial level” employed in ordinary products only requires germs attached on objects not to grow or to prevent them from growing and antibacterial paints that meet this standard are already available.

Paint films (films created with painting) that meet the performance of “antibacterial activity value of 2 or higher (antibacterial activity value is 1% or lower to the average value of the log value of viable bacteria counts after 24-hour cultivation of non-processed test pieces) have not been put into production so far.


The success in experimental development (experiment result was 3.6, exceeding the required criteria by a large margin) by the antibacterial product development project team was confirmed by a research institute of an antibacterial paint film having a capability of “antibacterial activity value of 2 or higher” requested by medical institutions as demonstrated with its test results (*).


The company is planning to put into production as antibacterial keyboards and antibacterial mouse used for operating PCs for electronic medical charts and medical devices and antibacterial films for touch panels, for the purpose of preventing nosocomial infections. Then we will extend the product range to in-hospital equipment such as handrails or partition boards.


*2: The test method is specified in JIS (Japanese Industrial Standard) Z2801:2012 “Antibacterial products-Test for antibacterial activity and efficacy and tests were conducted in the manner complying with the standards to calculate the antibacterial activity value.

Antibacterial performance that meets the needs from doctors

We have realized a sufficient antibacterial performance of antibacterial activity value 2.0 or higher (*) that users of medical institutions can use free of anxiety.

In addition, we have realized the required antibacterial performance using a mechanism that does not dissolve antibacterial components which may cause skin troubles, concerns in the conventional antibacterial products.

Nano-size antibacterial agent evenly distributed in the painting film will keep antibacterial efficacy without eluting those components so that users can use the product free of any anxiety.


*A JIS standard that requires the antibacterial activity value be 1% or lower to the average value of the log value of viable bacteria counts after 24-hour cultivation of non-processed testing pieces. 

Painting-an optimal technology for stereo structures

As an antibacterial material to be used in the medical applications, antibacterial films have already been put into production. Many of medical devices or equipment used in hospital environment, however, have complicated 3D shapes, which poses a problem that prevents films from following such shapes. The mist-painting technology that atomizes liquid for painting is able to shape a film to the shape of the object to paint can follow closely to complicated shapes such as a keyboard or a mouse for PCs indispensable for the present medical environment. Development of a painting technology that dissipate antibacterial agent evenly within the given paint film has enabled antibacterial efficacy to exert even at a worn thin paint film. In addition, our antibacterial paint film has passed the anti-wear test of 100,000-time keying using an artificial finger.

No effluence of components ensures anxiety-free application

The company’s antibacterial paint for medical purposes, unlike common antibacterial products, does not elute antibacterial agent and can be used free of anxiety of being skin troubles. This means that the design approach itself is completely different from other products whose antibacterial activity value is high only at the early stages when more components elute. Antibacterial paint may be applied as a post-processing for existing products and paint colors that can be prepared include clear blue, the material color of the antibacterial agent such as for antibacterial keyboards or mouse or almost transparent clear coat to be applied to a touch panel film. The paint film has a high transparency of characters and is applicable to such products as keyboards whose surface has processed characters. We meet requests from manufacturers to apply the antibacterial paint to their own products. Please feel free to click the button below for inquiry.

Even dissipation technology that can keep the efficacy until the end of the use life

The specific gravity of the antibacterial agent is heavier than that of paints and if it is painted using the ordinary technology makes the agent settle out within the paint film preventing the performance of the agent from exerting. To the contrary, making the agent float using an anti-settling agent results in the antibacterial agent to collect partially in the superficial layer and the antibacterial agent in the lower layer thinner, which means when the superficial layer is abraded away during use, and finally the antibacterial efficacy will be lost.

In order for the antibacterial efficacy to exert stably from the beginning of use to the end of use life when the paint film is worn out, it is necessary to dissipate the antibacterial agent evenly from the superficial layer to the deepest point of the paint film, which has been realized with our proprietary painting technology. 

Efficacy has been validated in a test by a public research institution

●JIS Z2801:2012 test results

Testing bacterial species:Staphylococcus aureus NBRC12732

Count of viable bacteria:4.9×105(count/ml)/inoculated dose:0.4(ml)

The reasons we have developed an antibacterial paint

President Kaname Kuboi has a bitter memory that his mother had been suffered for several years from infection during an operation of a cancer. He had been hoping to minimize in-hospital infection using industrial painting technologies which had been the Kuboi family’s business since his predecessor when he received a consultation about antibacterial paint films from medical personnel. The strong hope of the president drove pursuit for a higher performance not satisfied with a make-belief performance, which led to the realization of the requests by a lot of doctors.


Looking for products

The company is planning to release PC peripheral devices that meet antibacterial activity value of 2.0 and are antibacterial painted for medical institutions as products. 

Antibacterial keyboard for medical institutions

Antibacterial mouse for medical institutions

Touch panel sheet for medical institutions

Please feel free to send your opinions and requests about antibacterial paint or highly functional painting.

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KUBOI Coating Works Co.,Ltd.


1083-3 Nakashinden, Sayama City, Saitama Prefecture, Japan

TEL: 04-2958-5763

FAX: 04-2957-8097

*The company has acquired certification of ISO9001:2015 Quality Management System.

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