'Choetsu Technology®' is expected to deeply involve
advancements in many fields, including materials science and medicine,
contributing to global themes such as plastic reduction and SDGs, and
further to the virtuous cycle of economy and environment,
as a safe, cutting-edge technology originating from Japan.
'Choetsu Technology®' is a unique silica coating
technology invented in 1997 and still under research,
originating from Japan. It generates a glassy thin film by reacting with
OH groups (moisture or humidity) in the air or within substances,
without requiring strong acids, under near room temperature and pressure
conditions.
It is chemically neutral and does not contain harmful substances,
naturally decomposing in the environment after disposal,
thus imposing no burden on the human body or the environment.
*Choetsu Technology is a registered trademark of Choetsu Kaken Co., Ltd.
[Usage]
Apply Choetsu Liquid to paper, wood, stone, resin, metal, etc.,
generating a glassy thin film on the surface or inside the substrate
through chemical reaction bonding.
[Power and Effect]
Enhances the inherent water repellency, oil repellency, and rigidity
of glass, and can impart heat resistance, flame retardancy,
insulation, transparency,
radiation shielding, and antibacterial properties (adsorption and
decomposition).
Since application is done at room temperature in liquid form, it can
be applied evenly without damaging the material.
It is chemically neutral and generates a safe film layer for both
objects and the human body in three-dimensional directions.
The liquid is essentially colorless and transparent. Its viscosity
is generally 0.002 to 0.016 Pa.s, offering excellent workability.
The liquid is not of a single type; it is possible to adjust the film
layer according to functional requirements.
It can accommodate hardness, flexibility, moldability, and barrier
properties.
It generates chemical bonding reactions with the substrate fibers in
three-dimensional directions without requiring large amounts of water
or strong acids at room temperature and pressure.
(The reaction is generally accelerated by heating.)
Choetsu Liquid provides the following functions:
This technology generates a glassy thin film through reactions without
requiring large amounts of water or strong acids, at near room
temperature and pressure. It is chemically neutral and free of
petroleum-based resins, making it a safe technology that does not
burden the human body or the natural environment.
Additionally, upon combustion decomposition, it returns to silicon,
avoiding environmental pollution. It can be disposed of as general
household waste.
Since the liquid contains no petroleum-based resins, it is safe for the human body. A coated spoon has obtained a report compliant with US FDA (Food and Drug Administration) standards and passed EU food contact tests, confirming the safety of Silicagen Coat.
Imparts strong water repellency without compromising the substrate's texture. When applied to paper, it helps maintain shape even during prolonged water immersion.
Prevents the penetration of oils with small molecules and low intermolecular density, such as olive oil.
Titanium compounds are uniformly dispersed within the amorphous structure formed by the bonding reaction, performing adsorption and decomposition. This exhibits antifouling and antibacterial effects similar to photocatalysts, with effects lasting gently over a long period. It is characterized by exhibiting certain effects even in dark places.
Materials such as wood and paper treated with Choetsu Technology® are covered with a glassy thin film, making them less likely to combine with oxygen and thus less flammable.
The liquid seals microscopic cracks and irregularities invisible to the naked eye in three dimensions. For wood, it prevents water infiltration, discoloration/fading from UV rays, and general deterioration.
When applied to wood, it improves surface hardness. When applied to substrates with fibers like paper or cloth, the glass film coats the fibers, enhancing tensile strength.
Examples of Technology Application
*Depending on the material to be applied, it may not be applicable.
Choetsu Technology is also advancing research to mitigate the
effects of radiation on the Earth and human body, succeeding in evenly
dispersing tungsten molecules in the liquid.
We have developed materials with radiation shielding properties that
surpass lead by coating fibers such as paper, and currently hold
multiple related patents and utility models.
<Mechanism>
Fine tungsten powder binds with Silicagen Coat and siloxane through
the oxide film on the surface.
When Silicagen Coat combined with tungsten is applied and penetrated
into paper or fibers, tungsten powder is uniformly dispersed on the
coated surface.
<Production and Performance of Radiation Shielding Fabric>
Our company has developed radiation shielding fabric using our unique
radiation shielding technology.
The tungsten-coated radiation shielding fabric uses polyester as the
base material.
The fabric contains tungsten 740g/m² (87.5% by weight), polyester
85g/m², and glass thin film 105g/m².
Optical microscope observation of the outer surface and cut surface of
tungsten-coated radiation shielding fabric.
Both figures show that the tungsten powder is covered with a
chemically bonded glass thin film and is uniformly and stably embedded
in the fabric.
<Features of Our Radiation Shielding Clothing>
<Examples of Productization of Our Radiation Shielding Fabric>
① We delivered radiation shielding fabric mixed with tungsten to
companies developing radiation shielding clothing.
② As auxiliary shielding for high-energy accelerators, we produced and delivered collimator covers.
<Reference>
Shielding performance against 150keV X-rays and thermal neutrons
The shielding performance of tungsten shielding fabric was measured
using an imaging device at the Kyoto University Research Reactor
Institute (KURNS). The radiation sources were 150 keV X-rays from the
TRIX-150WE-OC X-ray generator and thermal neutrons from the E-2 hole
of the KUR reactor. Transmission imaging of X-rays and neutrons
through crepe-processed fabric and flat fabric was captured using a
combination of a scintillator and a CCD camera.
The results are as follows.
The two figures on the left in the diagram show the X-ray transmission results, and the right shows the thermal neutron results. Both the X-ray and neutron transmission images of the flat fabric on the right show no shading, indicating that tungsten was uniformly applied. The numbers represent the transmission ratio of radiation through the entire fabric. Subtracting the transmission ratio from 1 gives the shielding ratio of the fabric.
The above shows the shielding performance of tungsten shielding fabric
in terms of shielding rate, etc.
The shielding rate is quite high at 46.8% for the flat fabric. On the
other hand, the crepe-processed fabric has a shielding rate of 59.4%,
and considering that the weight of the fabric is almost twice that of
the flat fabric, it can be said that it is not as high as the weight
ratio. Especially when considering the exponential attenuation of
radiation within the shielding body, the attenuation trend for the
flat fabric extended to the weight of the crepe-processed fabric and
evaluated with a transmission ratio of 0.26 calculated shielding rate
of 74% is even lower.
The shielding performance of each shielding fabric is equivalent to a
lead thickness of 0.264mm for the flat fabric and 0.377mm for the
crepe-processed fabric. Compared to lead of the same weight, the
shielding performance is three times for the flat fabric and about
twice for the crepe-processed fabric.
Additionally, the transmission rate of thermal neutrons was 98.9% for
the flat fabric and 98.0% for the crepe-processed fabric. As a result,
the neutron shielding rate was 1.1% and 2.0%, respectively, and it was
found to be almost proportional to the weight of the fabric.
Comparison with Similar and Competing Technologies
Choetsu Technology belongs to a high rank overall as a shielding for scattered gamma rays and X-rays.
For inquiries about original development liquids, please contact us through the inquiry form
◇ It has been confirmed that polyester fabric (cloth) coated with
Silicagen Coat
has water repellency exceeding that of
fluorine-based water repellents.
As a result of conducting water repellency function tests by
applying the same amount of Silicagen Coat and fluorine-based water
repellent to 100% polyester, 100% nylon, and 100% cotton fabrics
in-house, it was confirmed that polyester has water repellency
exceeding that of fluorine-based water repellents, and nylon also
has the same level of water repellency (grade 4) as polyester.
Amid concerns about the harmfulness of fluorine-based water
repellents, the demand for Silicagen Coat as a safe water repellent
that does not contain any fluorine is expected. (Testing
organization: Japan Textile Products Quality and Technology Center)
◇ A spoon coated with Silicagen Coat passed the food contact
test,
confirming the safety of Silicagen Coat.
In the EU, where disposable plastics are banned, a wooden cutlery coated with our Silicagen Coat, which is attracting attention as an alternative, passed the food contact test, confirming the safety of Silicagen Coat. Early practical application of wooden cutlery in the EU is expected. (Testing organization: BUREAU VERITAS)
◇ By applying Choetsu Technology®, we
succeeded in smoothing the surface of removable dentures used in
the dental field
and effectively making them antibacterial.
By applying silica resin coating technology (Choetsu
Technology®), we succeeded in smoothing the surface
of removable dentures used in the dental field and effectively
making them antibacterial. A joint research group from Tsurumi
University, Neutron Science Center of the Comprehensive Research
Organization, and the Institute for Solid State Physics at the
University of Tokyo succeeded in effectively carrying
hinokitiol, which has antibacterial activity, on the surface of
dentures using silica resin coating technology (Choetsu
Technology®), and using CFU assay, fluorescence
microscopy, scanning electron microscopy, Fourier transform
infrared spectroscopy, proton nuclear magnetic resonance, etc.,
it was revealed that the application of silica resin coating
technology (Choetsu Technology®) can
effectively reduce surface roughness, improve hydrophobicity,
and effectively suppress the growth of the fungus Candida
albicans, which causes denture stomatitis. The paper also
mentions the potential application of silica resin coating
technology (Choetsu Technology®) to various
medical materials, and it is planned to proceed with research
for clinical application in the future.
The details of this research result were published in the
electronic version of Clinical Oral Investigation on August 15,
2022 (https://doi.org/10.1007/s00784-022-04670-z).
◇ Silicagen Coating: A High-Performance Protective Film with Antifouling and Antibacterial Effects
The University of Tokyo and
Neutron Science Center of the
Comprehensive Research Organization (CROSS)
◇ Application of Silicagen Coating to Cultural Properties
Efforts are beginning to utilize the effects of Choetsu
Technology, such as water repellency, antifouling, and
antibacterial properties,
to maintain and preserve cultural
properties in their natural form and prevent weathering, fungi,
and salt damage.
- Experimental coating on Boso stone and part of the exterior
wall at Nokogiriyama Museum
Experiment site: Nokogiriyama Museum Foundation*1 -
Experimental coating content: On November 18, 2022, Silicagen
Coat - for antifouling and antibacterial use - was applied to
parts of the Boso stone and exposed concrete parts of the
exterior wall of the Nokogiriyama Museum, which appeared to be
deteriorating, and the progress is being observed.
* Coating on Boso stone*2
It seems that the lichens attached to the Boso stone are
decreasing. Also, it seems that the dirt and deterioration of
the stone itself are being prevented. We will continue to
monitor the progress and verify the effects.
* Application to part of the exterior concrete
The actual coated part is suppressing surface deterioration
regardless of wind, rain, salt damage, or exhaust gas from the
roadside. We will continue to monitor the progress and verify
the effects.
[Impressions of Director Suzuki of Nokogiriyama Museum]
I am pleased that the lichens attached to the Boso stone coated
with Silicagen Coat are gradually regressing. Also, I feel that
the concrete coated with Silicagen Coat is less deteriorated
compared to other parts.
*1: About Nokogiriyama Museum: Opened in March 2010 as
Kanaya Museum.
As a symbol of "art" in Kanaya, Futtsu City, Chiba
Prefecture, which is working on town revitalization with the
theme of "stone and art," it has been familiar to local
residents and tourists until now. In 2020, the name was
changed to "Nokogiriyama Museum," named after the famous
mountain in Chiba Prefecture, Nokogiriyama. Since then, it has
been active as a museum promoting regional revitalization,
education, and contribution to the local community through art
and culture. It regularly holds the Nokogiriyama Competition,
cultural exchange exhibitions with Switzerland and Sweden, and
exhibitions of artists active at the forefront of the Japanese
art world. Located 1 minute on foot from Tokyo Bay Ferry
Kanaya Port, 5 minutes on foot from JR Uchibo Line Hamakanaya
Station, and 3 minutes by car from Tateyama Expressway Futtsu
Kanaya Interchange.
https://nokogiriyama.com/
*2: About Boso stone: A general term for tuffaceous
sandstone or volcanic breccia tuff quarried from Nokogiriyama
and its surroundings in the central and southern part of the
Boso Peninsula. The one applied this time was taken from
Nokogiriyama.
◇ Successfully Antiviralizing Mask Nonwoven Fabric Filters Using Choetsu Technology®
Research Group of Professor Kazuhito Satomura, Department of Oral Medicine, School of Dentistry, Tsurumi University
By applying silica resin coating technology (Choetsu
Technology®) developed by Choetsu Kaken Co., Ltd., we succeeded in effectively
antiviralizing nonwoven fabric filters inside surgical masks
widely used in medical settings. The research group of
Professor Kazuhito Satomura, Department of Oral Medicine,
School of Dentistry, Tsurumi University, succeeded in
effectively carrying antibacterial substances on the fiber
surface of surgical mask nonwoven fabric filters by combining
Choetsu Technology® with various antibacterial
agents, and reported that inactivation effects of 99.999% or
more against human coronavirus could be imparted to the
nonwoven fabric using any of the antibacterial agents
tested. This makes it possible to easily antibacterialize
and antiviralize existing masks by applying Choetsu
Technology®. Furthermore, the paper mentions the
possibility of easily carrying various functional substances
on the surface of various materials using Choetsu
Technology®.
The details of this research result were published in the
electronic version of the International Journal of
Environmental Research and Public Health on March 22, 2022
(https://doi.org/10.3390/ijerph19063639).
