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Superhydrophilic Inorganic Coating

Product Name

Superhydrophilic Inorganic Coating

Superhydrophilic polysilicate inorganic coating agent with excellent weather resistance, antifouling properties, and high transparency. The low viscosity of this agent makes it easy to apply on the surfaces. Excellent in workability.


CeraAqua is a superhydrophilic polysilicate designed as a inorganic coating agent having excellent weather resistance, antifouling properties, and high transparency at the same time. Applicable to to the anti-fouling of solar panels and external walls with its self-cleaning and the anti-static effect. The low viscosity of this agent gives easiler application in actual coating works.


After applying CeraAqua on the base material, the silanol group in the agent is strongly bound to the surface material to form a hard film which builds a superhydrophilic antifouling coating.


(1) Antifouling property

Painted surfaces, tiles, glass, and metal surfaces under outdoor environment are tend to be discolored to black due to contamination in the air. CeraAqua coating, with its hydrophilicity, gives self-cleaning property to the surfaces, which removes dirts by rainwater restoring the surface to its original condition.

【Image Diagram】

The hydrophilic film formed by CeraAqua coating on the painted surface
removes the attached dirts by rainwater.

(2) Weather resistance

Because the film coated with CeraAqua consists of inorganic polysilicate, it forms highly light-transmissive layer insoluble in water.  It is very stable to ultraviolet and infrared rays causing no discoloration or degradation of light transmittance.

(3) High transparency/light transmission

Polysilicate-based inorganic coating agent has low refractive index and high light transmittance, which improves the transparency of glass and other transparent materials.

(4) Easy-to-install

Because of its low viscosity, it has excellent applicability and shows strong adhesion to the base material.   The cure time can be shortened by heating from room temperature.

Antifouling Test

(1) Accelerated Test for Transparent Plates (Civil Engineering Research Center)

The antifouling test of a light transmitting plate for trafficway was conducted
by the Civil Engineering Research Center.

  1. Standard black contaminant was applied on the glass surface coated with CeraAqua.
  2. After the surface was dried, water was sprayed to remove contaminant.
  3. Light transmittance and color difference of the surface were measured.

The followings are the results.

Reference value Results
Color difference △L - 3.20≦ △L - 0.68
Transmittance 66.0≦ 94.2

(2) Exposure Test of painted Steel Sheet: Antifouling Test by Raindrop

CeraAqua coating     No coating

(3) Improved Antifouling of window glass

CeraAqua coating     No coating

Light transmission Test

Test sample: solar-cell cover glass. The comparison was made between the sample coated with CeraAqua and the another one without. CeraAqua coating made improvement of light transmittance in all light wavelengths tested.

Coating agent :CeraAquaa NS235-N1
Film thickness :Dry film thickness0.3μm
Measuring equipment

:Ultraviolet-visible spectrophotometer V530
(Nippon Spectroscopy Co., Ltd.)


Wavelength (nm) 400 500 600 700 800
No coating 91.3% 91.6% 91.5% 91.0% 90.4%
CeraAqua coating 92.1% 92.8% 93.0% 92.8% 92.4%

Water resistance Test

Showering test (pump:70ml/cm²/minute)

Shower at 4,000ml/cm³/h, i.e. 4,000mm precipitation per hour.

Test sample: solar-cell cover glass. The comparison was made between the sample coated with CeraAqua and the another one without.


Exposure time 0 hour 24 hours 48 hours 72 hours 96 hours 120 hours
No coating 50.6 46.3 40.7 38.2 36.6 35.5
CeraAqua coating - - 2.5 3.0 5.3 5.0

Note: ( - ) indicates unmeasurable by contact angle meter.


  1. Metal-based or ceramic-based outer wall paints, tiles: Antifouling by self-cleaning effect and  antistatic property.  Protection of base material.
  2. Architectural window glass: Reduction of cleaning times by self-cleaning effect .
  3. Solar cell cover glass: Maintaining and improving light transmittance by anti-fouling and low refractive index.
  4. Window glass for automobiles and trains: Long-term antifouling and transparancy by its superhydrophilicity.
  5. Mirror: Anti-fogging property due to superhydrophilicity.
  6. Street lights and lighting fixtures (LEDs, etc.): Anti-fouling of cover glass
  7. Soundproofing walls for traficway (metal, acrylic, poly, etc.): Anti-fouling and anti-soiling

Examples of application - house exterior wall

CeraAqua coating applied to acrylic silicone exterior paint for antifouling protection

Air spray coating at construction site using the CeraAqua

Coating method

Pretreatment for glass substrate

Lightly polish the glass surface with abrasives to remove stains on the surface, or slightly shave the surface to let clean active surface appear.
Wash with water, then dry completely.

Pretreatment for exterior building materials

Clean the organic painted surface with a hot water high-pressure cleaning device and dry it thoroughly.
If the painted surface is cracked, use a primer G130 to fill the crack.

Pretreatment for film substrate

Apply corona discharge treatment or primer painting.  Apply CeraAqua at soonest possible timing afte pretreatment.
When using primer, CeraAqua primer G130 is recommended.

Application tool

Roll coater, flow coater, air spray, sponge roller, brush

Conditions of application


:30μm(wet thickness)
Cure temperature :room temperature~200℃×5minites
Film thickness :0.3μm or less(dry thickness)

Product details

Trade name

1.CeraAqua NS235-N1
2.CeraAqua NS244-N1.5


1.Inorganic ingredients : Silica Compounds of Polysilicate Condensates
2.Solvents : Alcohols and propylene glycol ethers


Appearance :Clear colorless liquid
Specific gravity :0.85~0.89
Viscosity :1~3mPa・s
Solids content :0.9~1.6%

Hazardous material Classification

Class 4, Class 1 Petroleum

Storage stability

3-6 months from the date of manufacture

R&D Center

At our R&D center, we are developing materials to respond to customers various requirements.
If you have any opinion or resquest, please do not hesitate to contact us.