TECHLOGYKaltech's unique photocatalytic technology
1光触媒とは
What is a photocatalyst?We often get asked this question.
Photocatalyst uses titanium oxideIt is the main material.This titanium oxideIt is a type of semiconductorBy exposing it to lightWith that energyViruses, bacteria, odors, etc.Decomposes organic matter.
The effect of this photocatalyst isIn 1972, a British scientific journalIt was published in Nature,Now named after its discovererIt is also known as the "Honda-Fujishima effect."
Titanium oxide is not only the main material for photocatalysis,Chocolate, etc.Food coloring additives andexterior building paint,Plastics, printing inks, etc.It is used for various purposes.
Photocatalytic effects
The figure above shows the effect of photocatalysis.
leftThe figure shows the effect of photocatalysis.
When a photocatalyst filter coated with photocatalyst is irradiated with light such as LED light, a strong oxidizing power is generated on the surface. When organic matter in the air, such as viruses, bacteria, and odors, comes into contact with the surface of the photocatalyst, it is decomposed by this oxidizing power.
This oxidizing power is stronger than that of ozone or hypochlorite, but it does not float in the air and does not affect the human body.
2Caltech's uniqueness
In recent years, the range of applications of photocatalysts has expanded due to improvements in their performance.
Through its materials research, Kaltech's photocatalysts have achieved the highest level of performance in the industry.
Among them, photocatalytic materials are unique and truly the "secret sauce."
By applying unique innovations to this photocatalytic material, we have succeeded in developing a photocatalyst that is both highly efficient and durable.
Furthermore, to maximize the effectiveness of superior photocatalysts, we need the ability to develop unique products that take advantage of their characteristics.
Because we are "Photocatalyst Kaltech," we are able to handle everything from photocatalytic materials to product development, creating excellent products.
"Secret sauce" unique photocatalyst
From material development to commercializationEnd-to-end development
Photocatalytic materials
Photocatalytic materials
光触媒フィルター
Kartech Products
3Verification of photocatalytic technology
At Kartech, we are a venture company that conducts testing that major manufacturers cannot do, in order to contribute to society at large through the effects of our unique photocatalysts.
In October 2020, through joint research with the RIKEN Institute and Nihon University School of Medicine,We have verified and announced that our photocatalyst can inactivate the airborne novel coronavirus.This result was published in a paper in an overseas virology journal and received a great deal of attention.
This is the world's first attempt to demonstrate the inactivation effect of a photocatalyst on airborne COVID-19.(Survey conducted by our company in October 2020).
Additionally, we are currently conducting joint research with Nihon University School of Medicine to evaluate the effectiveness of photocatalytic devices in suppressing infectious diseases in clinical settings, and announced interim results in October last year confirming their effectiveness.
The results of this research are expected to contribute to the prevention of infectious diseases caused not only by the new coronavirus but also by common bacteria, viruses, and fungi in practical environments, especially among elderly people with weak immune systems and patients with underlying diseases who are vulnerable to infection.
Press conference (October 2020)
③-1 Testing the inactivation of the new coronavirus in an experimental environment
Published in MDPI's professional magazine, Viruses
Photocatalyst successfully reduces the infectiousness of airborne novel coronavirus to below the detection limit
- Presenting measures to realize a "With COVID-19" society and combat the new social threat of "mutant viruses" -
| Paper title | SARS-CoV-2 disinfection of air and surface contamination by TiO2 photocatalyst-mediated damage to viral morphology, RNA, and protein |
|---|---|
| Presenter | University of Tokyo, RIKEN, Nihon University |
| URL | (English)https://www.mdpi.com/1999-4915/13/5/942 |
| (Japanese sentence)https://www.a.u-tokyo.ac.jp/topics/topics_20210521-1.html *The University of Tokyo has also issued a press release with the same content. |
- <Researcher's comment> Yoko Hazama(Aida Yoko) Mr
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Department of Hematology and Rheumatology, Department of Internal Medicine, Nihon University School of Medicine Senior Visiting Researcher/RIKEN
(Currently a specially appointed professor at the Graduate School of Agriculture and Life Sciences, The University of Tokyo)"This is the first time in the world that photocatalytic technology has been demonstrated to reduce the infectiousness of airborne COVID-19 below the detection limit. This is expected to help create safe, clean spaces that will help realize a society where people can live with COVID-19. It also paves the way for us to overcome new strains that are currently posing a threat, as well as unknown viral infections that could pose a new social threat. We believe that photocatalytic technology will continue to make an even greater contribution to society in the future."
1) Inactivation of the novel coronavirus (SARS-CoV-2) by photocatalysis
For the first time in the world, we have demonstrated that photocatalytic technology can eliminate the infectivity of the novel coronavirus (SARS-CoV-2) floating in the air to below the limit of detection.
120 liter acrylic box.
Inside, a sterilization and deodorization machine equipped with Kartec's photocatalyst is installed.
- <Test Method>
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- Aerosolized SARS-CoV-2 of cough-equivalent size (particle diameter 5 μm) was sprayed into a 120-liter acrylic box.
- After treatment with titanium oxide photocatalyst, the air was collected using an air sampler and the viral infectivity was measured.
- Test time: 0 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes
- Photocatalytic device: Kartec sterilization and deodorization device, LED 405nm
- <Test Results>
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- Significant time-dependent decrease in infectious titer
- Inactivates 99.9% of SARS-CoV-2 in aerosols in 20 minutes
Viral infectivity (vertical axis) and the time relationship between photocatalyst and LED light source (horizontal axis)
*Control is for comparison purposes and does not have photocatalyst or light.
2) Photocatalysis decomposes the S protein and inactivates the virus
This is the first time that we have shown that reactive oxygen generated by the photocatalyst may be one of the causes of the degradation of S proteins and other proteins on the surface of virus particles, destroying the viral membrane and damaging the viral RNA.
- <Analysis by electron microscope>
- Through analysis using an electron microscope, the research group revealed that the photocatalytic reaction reduces the number of virus particles, increases the size of the virus particles, and reduces the number of S proteins on the surface of the virus particles.
③-2 Verification of the effectiveness of photocatalysis in preventing infectious diseases in a clinical environment (interim report)
The Division of Hematology and Collagen Diseases, Department of Internal Medicine, Nihon University School of Medicine and Caltech are conducting joint research to verify the effectiveness of photocatalytic devices in preventing infections within hospitals. The device is expected to be effective in preventing not only COVID-19 infections but also infections caused by common bacteria, viruses, and fungi in real-world environments for elderly patients with weak immune systems and those with underlying diseases who are vulnerable to infection.
*This information was announced in October 2021.
| Title | Expectations are high for the effectiveness of photocatalytic sterilization and deodorization in preventing infections among vulnerable individuals in practical environments |
|---|---|
| Presenter | Department of Hematology and Collagen Diseases, Nihon University School of Medicine, Caltech Co., Ltd. |
| URL | https://kaltec.co.jp/news/wp-content/uploads/2021/10/【プレスリリース】実使用環境下における感染弱者の感染症予防効果.pdf |
- With the approval of Nihon University's Ethics Committee, a certain degree of effectiveness has been confirmed in a clinical environment, and verification is currently ongoing, with a presentation at an academic conference planned for the future.
- <Verification method>
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In a ward for patients with malignant tumors and collagen diseases, sterilization and deodorization machines equipped with photocatalysts will be installed in 23 patient rooms and in the corridors, and the change in the number of patients with infectious diseases before and after the installation will be examined.
*Nosocomial infections are defined as infections that occur 48 hours or more after admission. - <Result>
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- Overall infection incidence rate 12/65 → 3/63 P value: 0.052
- Infection rate for those aged 65 and over: 10/30 → 2/39 P value: 0.003
- Infection rate in patients with underlying diseases: 13/61 → 6/62 P value: 0.086
- Incidence of patients with neutrophils <500 μl: 12/14 → 3/25 P value: <0.0001
Before installation: April 11, 2020(1 months)
After installation: April 11, 2021(1 months)
- <Conclusion>
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This study demonstrated the effectiveness of infection prevention in vulnerable individuals with weak immune systems.
As the aging society continues to progress, it is expected that the number of patients living in elderly care facilities and those receiving palliative care after anti-cancer drug treatment will increase. We hope that the results of this study will help reduce the worries of patients suffering from these infections and provide them with a peaceful life.
- <Researcher Comment> Kazuhide Iizuka(Iizuka Kazuhide) Mr
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Nihon University School of Medicine, Department of PathologyAssistant Medical Director of Clinical Laboratory Medicine
"It is highly significant that we have been able to obtain data that supports the effectiveness of photocatalytic sterilization and deodorization devices in real spaces, based on previous laboratory-level testing, as a measure against bacterial, fungal, and viral infections. Reducing the risk of infection in hospital rooms could potentially shorten patients' hospital stays and reduce the cost of administered medicines. Because immunity weakens with age and the risk of infection increases, this device is also expected to be effective in nursing homes and other care facilities with a large elderly population."
4Mold suppression
The effectiveness of photocatalysis in decomposing mold has been demonstrated.
We are developing products that utilize these effects to help reduce food waste.
We tested it on black mold that grows on bread.
We placed a loaf of bread in each of the two Food Fresh Keepers and tested the extent to which mold growth inside the cabinet could be suppressed with or without the photocatalyst (power on and power off).
The experiment began on November 22nd. Nine days later, on December 1st, black mold had grown extensively on the surface of the bread without the photocatalyst. On the other hand, no mold growth was observed on the bread with the photocatalyst. The photocatalyst was able to suppress the growth of black mold.
- These are the results of our experiments and are not a guarantee.
We tested it with seasonal fruit, mandarin oranges.
Following the experiment on black mold on bread, we tried it on mandarin oranges, a fruit that is essential in the coming season.
Oranges stored at room temperature without the use of photocatalysts have dry, wrinkled surfaces. On the other hand, oranges with the use of photocatalysts have shiny surfaces and look delicious. It is believed that this has helped to maintain the freshness of the oranges.
We tested it with mochi, which is prone to mold.
Following the experiments on black mold on bread and mandarin oranges, we tested it on freshly pounded rice cakes for a week.
Compared to the mochi preserved using the photocatalyst, the mochi preserved at room temperature without the photocatalyst shows a thick layer of mold growing on the surface.
5Decomposition of ethylene gas
Ethylene gas is a type of plant hormone secreted by vegetables and fruits, which promotes their own ripening. However, the ethylene gas emitted by vegetables and fruits also affects other fruits and vegetables, so storing them in the same space can cause the other fruits to deteriorate faster.
In the experiment, apples and bananas were placed in a plastic case. By placing a photocatalyst in an enclosed space, it was confirmed that the ethylene gas was broken down and the deterioration of the bananas was suppressed.
Apple/banana freshness test
Tested at room temperature (25°C ± 2°C)
| No catalyst | With catalyst | |||||||||
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| November 25st (start) |
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| November 29st (Day 5) |
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| November 4st (Day 11) |
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6Water purification demonstration
Photocatalysts can be used not only for air purification but also for water purification. We are working on water purification using photocatalysts that utilize recyclable waste by coating a lightweight foam material made from waste glass with photocatalysts.
In an experiment, river water was placed in a tank, and a lightweight foam material coated with photocatalyst was submerged and left in the sun. The water became clearer in just one day. This is thought to be because the organic matter in the river water was broken down by the photocatalyst.
Transparency comparison
7Suppression of hay fever
With the cooperation of Izu Nanamikai Medical Corporation's Atami Tokoro Memorial Hospital, 11 male and female hay fever sufferers wore a photocatalytic sterilization and deodorization device under their face. They then used a questionnaire created by our company to indicate the condition that most closely resembled their subjective symptoms of hay fever, on a scale of 10 to 10 (the higher the number, the worse the condition).
The results showed that symptoms improved in all hay fever patients. This is believed to be due to the effect of the photocatalytic sterilization and deodorization device placed under the face emitting clean air that was free of pollen and bacteria, preventing pollen from entering the subjects' bodies.
The symptom questionnaire was created under the supervision of Dr. Kazuhide Iizuka of the Department of Clinical Laboratory Medicine, Nihon University School of Medicine.
熱海所記念病院
Result
- All subjects were confirmed to have improved symptoms of hay fever.
- Approximately 90% of the subjects experienced improvement in "eye symptoms," "amount of tears," and "nasal congestion/difficulty breathing through the nose," and all patients generally showed a tendency for improvement in other subjective symptoms.
Percentage of people who experienced an effect on their main symptoms
- Eleven hay fever sufferers were asked to wear a small photocatalytic sterilization and deodorization device and their subjective symptoms of hay fever were investigated two weeks later. The results were graphed for patients who had subjective symptoms for each item before the device was installed.
[Symptoms of hay fever]
- Eye symptoms(itching, foreign body sensation, redness)
- Amount of tears
- Nasal congestion and difficulty breathing through the nose
- Frequency of blowing your nose
- Frequency of sneezing
- Throat discomfort/pain
- Decreased ability to think and concentrate
- Difficulty in speaking and pronunciation
- Headache/Headache Complete
- Itchy skin
Clinical trial
| subject | Medical institutions | Clinical period |
Used equipment |
|---|---|---|---|
| In their 20s to 40s 11 men and women |
Medical Corporation Association Izu Nanamikai 熱海所記念病院 |
2022 December |
A small photocatalytic sterilization and deodorization device manufactured by our company was attached under the subject's face. |
Confirmation of subjective symptoms
- The subjects wore our small photocatalytic sterilization and deodorization device under their faces.
- Subjects were asked to fill out a symptom questionnaire supervised by a doctor, and to indicate on a scale of 1 to 10 the symptom that most closely resembles that caused by hay fever (the higher the number, the worse the condition).
- To prevent the spread of COVID-19, masks are worn on a daily basis. When removing the mask for meals or other purposes, the device should remain on.