CONTURAN®

SCHOTT’s experience and expertise has resulted in the creation of a series of innovative and versatile CONTURAN® glass products. Made almost entirely anti-reflective by SCHOTT’s unique sol-gel technique, CONTURAN® can be adapted for a wide variety of roles through special coating and thermal toughening.

A wide range of properties for a wide range of uses

Pioneering coating process

In SCHOTT’s sol-gel dipping method, glass is submerged in metal oxide solutions and the metal oxide coatings are burned in at up to 500°C. These layers generate interference that eradicates almost all reflection. CONTURAN® has less than 0.5% reflection on each side compared to 4% for uncoated glass.

Reflection-free vision

Thanks to the SCHOTT’s cutting-edge coating technique, CONTURAN® offers less than 1% reflectance and allows up to 99% light transmission, resulting in glass with exceptional clarity.

Innovative customization

Curved, shaped and coated, CONTURAN® can be customized to suit any situation. Even when curved, the glass doesn’t lose its anti-reflective qualities, and further options include protective layers against UV and IR light, and fingerprint elimination via DARO coating.

Tough and durable

CONTURAN® can be thermally toughened, giving the glass up to four times more mechanical and thermal strength than non-toughened glass. This unique glass can also be chemically strengthened through its anti-reflective layer – the only anti-reflective glass in the world with this feature.
Types

CONTURAN® can be made using a variety of base glasses, each of which has their own unique properties. 

 

Soda-lime float glass

  • Often used in both technical and non-technical applications
  • Solid optical mechanical and chemical properties

 

BOROFLOAT® borosilicate glass

  • Floated borosilicate glass
  • Highly transparent
  • Outstanding thermal resistance
  • High chemical durability

 

Aluminosilicate Glass

  • Floated aluminosilicate glass
  • Unmatched mechanical resistance
  • Withstand impacts and shocks
  • Offers highest levels of flexural strength and scratch resistance

 

CONTURAN® is available in different variants: 

Conturan variants

 

 
Anti-Reflective Properties

CONTURAN® anti-reflective glass is a float glass with optical interference properties coated on one or both sides to minimize surface reflections. A special immersion procedure is used to apply multiple metal oxide layers just nanometers thick. Reflections are reduced optically by up to 90% and the glass appears invisible. At a transmission of >98%, viewers can then focus on what’s important.

 

Advantages of SCHOTT CONTURAN®

  • Luminous reflectance of 0.9%
  • Appears invisible
  • Neutral in color
  • High transmission
  • Color rendering index of Ra = 100

 

Float vs anti-reflective glass 

Conventional float glass has dependable but limited optical properties. At just 91% transmission, a significant amount of light is lost. The smaller share of this (approximately 1%) is absorbed by the glass itself. The other 8% is reflected by the glass surface. This reflection is perceived as highly inconvenient, especially in applications which require clear viewing. Surface finishing can help here.


Disadvantages of float glass 

  • Luminous reflectance of 8%
  • Undesirable reflections
  • Lower transmission
  • Colors appear drab
 

 Float glass

Float glass

 Float glass

SCHOTT CONTURAN®

1% luminous reflectance of SCHOTT CONTURAN® compared to 8% luminous reflectance of regular glass.

Durability

SCHOTT understands the importance of clear and consistent vision for outdoor displays, so produce a series of high-tech, anti-reflective glass of the highest quality with surfaces that are extremely tough, reliable, and easy to clean.

 

Benefits of SCHOTT dip-coated glass

  • Burned-in surface coating 
  • Highly resistant to abrasion
  • Extremely stable

 

CONTURAN® is also mechanically robust and highly resistant to chemicals, delivering durable performance in every application. Key properties include:

  • High mechanical durability proven by international standards
  • Easy handling and processing
  • Robust surface for daily cleaning cycles

 

Testing

CONTURAN® undergoes a series of rigorous tests, split into mechanical and chemical:


Mechanical tests

  • The Tesa Test highlights the durability against the forces of adhesive tape being ripped from the coating.
  • Taber Abrasion Test, which tests the abrasion resistance of the coating. 
Testing 

 

 

Testing the abrasion resistance of coating with the Taber Abrasion Process

  • The Pencil Hardness Test checks scratch resistance. Here CONTURAN® achieved class 9H, a significantly higher score than other anti-reflective surfaces.

 

Testing 

 

Pencil Hardness Test to check scratch resistance

  • The Cheesecloth Test is a good indicator of the resistance of the coating. It’s based on DIN ISO 9211-4 and simulates moderate abrasion. In this test, a cushion of gauze is pressed onto a coated surface with a certain force and then moved several times. The surface is then checked for damage. Competing products are 95% worse than SCHOTT products in this test.

Testing

Cheesecloth test shows the good resistance of the coating

 

Cleaning tests

The test was carried out by the materials testing center in Karlsruhe in accordance with the UB MED guideline MFR 890/009, which subjected CONTURAN® to intensive resistance testing. The test applied standard, medical-sector cleaning agents containing various classes of active ingredients and then examined their impact on CONTURAN® over several hours. The surfaces and their appearance were assessed and evaluated. Based on this, we provide recommendations on the majority of the substances tested:

Class of chemical agent Specific test medium   Result  

Alcohol

Incidur-Spray (undiluted), Ethanol (96 % Vol.), Mykrozid liquid (undiluted),Meliseptol rapid (undiluted), Isopropyl (70 %)

Aldehyde

Melsitt (10 % Vol.), Lysoformin (2 % Vol.), Aldasan 2000 (4 % Vol.),
Kohrsolin (0.5 % Vol.), Dismozon (0.5 %)

Peroxide compounds

Perform (3 %), Hydrogen Peroxide (3 %)

Pyridine derivative

Spray Activ (undiluted)

Benzine

Benzine / Petroleum ether (undiluted)

Dish liquid

Regular dish liquid (1 %)

Organic acids

Bio-AntiBact med

Limewater

Alkylamine

Incidin Plus (8.0 % Vol.)

Quaternary compounds

Mykrozid sensitive liquid (undiluted), Morning Mist (1:64 diluted),
Terralin protect (2.0 % Vol.), Microbac®Tissues (direct)

Taski Sprint DS 5001 (0.5 % Vol.), Sulfanios Fraicheur Citron (0.25 % Vol.)

Chlorine derivatives

Sodium hypochlorite (bleach; 10 %)

Terralin (0.5 % Vol.)

Antiseptic agent

Chlorhexidin (0.5 %) in Isopropyl (70 %)

Ammonia

Ammonia hydroxide solution (1.65 % Vol.)


✓ = safe to use
•  = residues may accumulate on the surface

 

 

Chemical and corrosion resistance tests

  • CASS (Copper-accelerated acid salt spray) test for 21 days at 50°C based on DIN EN ISO 9227.
  • NSS (neutral salt spray) testing with sodium chloride at 35°C based on DIN EN ISO 9227.
  • Coating durability against cleaning chemicals proven by a test based on guideline UB MED MFR 890/009.

 

 

Climate resistance

  • Condensation atmosphere with constant humidity – 21 days storage at 40°C and humidity 100% based on DIN EN ISO 6270-2-CH.
CONTURAN® Daro

The difference between anti-reflective glazing and CONTURAN® DARO can be seen immediately. This durable, anti-reflective coating with oleophobic properties is one of the best products on the market for eliminating fingerprints and smudges on display glazing.

 

Specifications of CONTURAN® DARO

CONTURAN® DARO
Supply forms
  • processed glass
  • stock sheets
Thickness from 1.1 to 6.0 mm
Dimensions up to 990 x 1,770 mm (72” diagonal)
Available on all CONTURAN®types
Processing

can be combined with any type of
processing you require, for example:

  • screen printing
  • tempering
  • laminating
  • etc.

 

Fingerprint-free

Fingerprints have a crucial impact on the optical properties of an anti-reflective coating and are much more visible than on uncoated glass. CONTURAN® DARO eliminates these fingerprints using a combination of oleophobic and hydrophobic properties, reducing their visibility down to 10%.

CONTURAN® DARO 

 

Easy-to-clean

The DARO coating is a proprietary blend of hydrophobic and oleophobic molecules that are optimized to bond with the nano-features of SCHOTT´s anti-reflective coating. Oleophobic and hydrophobic surfaces (initial water contact angle > 110°) don't allow grease and sweat from fingers to stick to the glass and any remaining residues can be removed very easily by dry wiping. 

Easy to clean Easy to clean

 

Equally applied imprint on CONTURAN® DARO and anti-reflective glass (both glasses wiped dry three times)

 

Long-term durability

In order to use an anti-reflective coating in a touch application, it must have an oleophobic coating that can withstand hundreds of thousands of finger touches and rubs. CONTURAN® DARO fulfills this demand and maintains properties such as reduced visibility of fingerprints, easy-to-clean surface and good haptics, even if subjected to harsh mechanical and chemical stress.

 

Proof of durability for touch applications 

  • The Tesa Test highlights the durability against the forces of adhesive tape being ripped from the coating.
  • Taber Abrasion Test, which tests the abrasion resistance of the coating.
  • The cheesecloth Test is a good indicator of the resistance of the coating. It's based in DIN ISO 9211-4 and simulates moderate abrasion.

Proof of durability for touch applications

 

Surface testing

Surfaces of touchscreens need to withstand hundreds of thousands of finger touches. Touching the surface leads to mechanical abrasion and chemical wear because of the salt in finger sweat. In order to prove the durability of CONTURAN® DARO, we perform mechanical abrasive tests (cheesecloth rubs) as well as chemical resistance tests (salt spray). 

 

Surface testing 

 

Chemical Toughening

The hardness of a glass is increased by performing a special treatment in a salt bath (chemical tempering). Smaller ions from the glass surface are replaced by larger ones from the salt bath by way of ion exchange. This creates compressive stresses in the surface, which increase the strength of the glass.


Before

Chemical Toughening

After
Chemical Toughening 

This process is known as chemical tempering or chemical toughening, and is particularly well suited for thin glasses with a thickness of less than 3.2 mm, which can no longer be easily thermally tempered. 

 

Reduced process complexity in chemical tempering 

SCHOTT offers the only anti-reflective coating designed for chemical tempering through the coating layer of CONTURAN® Tough. In a complex process chain, chemical tempering is performed first, before a standard anti-reflective coating is applied. 

Reduced process complexity in chemical tempering  

Until now, toughening took place prior to the application of anti-reflection coating, because conventional sputtered anti-reflective coatings prevent the ion exchange required in the toughening process. However, introducing the coating at a later stage of the process chain requires a one-off production, which is an extremely inefficient procedure.

CONTURAN® Tough and CONTURAN® Tough AS provide a crucial difference. These anti-reflective glasses are the only one of their kind that permit chemical toughening all the way through to their anti-reflective coating thanks to SCHOTT’s unique sol-gel coating. This provides notable improvements compared to standard procedures.

CONTURAN® Tough enables ion exchange through the anti-reflective layer, thereby greatly simplifying the process chain. Large format glass can be coated with the anti-reflective layer first then processed further, which results in a much more efficient procedure. 

Want to know more? Let’s talk

Whether you need more information, samples, a quote, or advice for a project, we would be delighted to talk to you.

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