Signet Armorlite AR Coating Process Guidelines

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PURPOSE: To provide optimized AR coating process parameters for various Signet Armorlite RLXPlus® lens products. This will also assist Signet Armorlite’s KODAK CleAR™ Coating partner labs with washing instructions for SA lenses through the varied AR ultrasonic wash units installed at their facilities.

REVISION: First bullet point changed - RLXPlus in-molds coated lenses should not be exposed to an ion pre-cleaning.

GENERAL: The following are some primary requirements for optimal AR adhesion when AR coating RLXPlus in-mold and non in-mold hard coated lenses:

- RLXPlus in-molds coated lenses should not be exposed to an ion pre-cleaning.
Because in-mold RLXPlus is acrylic based, this step will reduce the potential adhesion to our hard coating regardless of the AR recipe application used. We have tested and proven that this step (in combination with other recipe elements) is not necessary for optimal adhesion even with silicon-based hard coatings, provided proper cleaning has been performed and the front surface is AR coated first.

- Chromium should be used as the initial adhesion material.
For RLXPlus in-mold coated lenses, we have found that chromium with a high purity rating gives the best overall adhesion characteristics. This also works exceptionally well with other hard coating types by the vast majority of lens and coating manufacturers. If the % purity value of the first layer material is over 99% chromium, assume it is not compatible with RLXPlus in-mold coated lenses. Only about 1 to 1.5 nanometers are needed to achieve the desired results (any more than this runs the risk of serious absorption issues).

- IIt is generally best to apply the entire AR stack (except hydro) to the front side first.
This ensures the RLXPlus in-mold lens surface is not contaminated from AR coating the backside first. This is required since you will not be using an ion pre-cleaning process on the RLXPlus in-mold coated surface.

We have tested many other factory coatings and have found coating the front side first can improve adhesion of both sides. No negative test results have been found by AR coating the front side of the lens first. The following will define this product line by refractive index and base material as this is the best way to identify the correct coating type:

Signet Armorlite coating type by lens material

RLXPlus should be pre-treated or washed with a chemical caustic solution in an ultrasonic bath. This ultrasonic pretreatment is formulated to better clean the RLXPlus surface to accept evaporative materials. The pre-treatment information is divided into two sections, one for labs with Leybold or Satisloh installed ultrasonic wash lines and one for Zeiss installed wash lines..

Why is this necessary?
Signet Armorlite RLXPlus in-mold coating is not sensitive to caustic materials. Thus it cannot be etched or stripped off the lens. Lens coatings with silica in their composition have a layer of their surface removed by exposure to caustic solutions, thus allowing their surfaces to be easily cleaned by this etching process. When the hard coating is not etched by the caustic solution, a sufficient caustic strength and exposure time is needed to remove contamination. When this is accomplished and the other parameters recommended in this TIP are followed, an AR-coated RLXPlus lens will have excellent abrasion resistance and AR coating durability.

For Leybold or Satisloh Labs:
We recommend all Signet Armorlite in-mold hard coated lenses be pretreated with a stand-alone, tabletop ultrasonic unit. This should be done before placement in your AR manufacturer’s ultrasonic wash unit. Use the following chemistry mix for this recommended pretreatment:
15.0 grams Optical 2010 per liter of deionized water
Ultrasonic agitation at 60°C for four to five minutes
All lenses that are not in-mold coated should never be run in this pre-treatment solution because severe damage to the factory hard coating will occur.

For Zeiss Labs:
All Signet Armorlite in-mold hard coated lenses are recommended to be cleaned using the 300 second wash process.

To all: For products that are not in-mold, a milder wash process, such as that defined by your AR coating equipment and process provider, is likely acceptable. We can verify this if you provide the chemical mixture, temperature and cycle times by washing step..

Please contact Steve Drake at Signet Armorlite Technical Services with questions, concerns, or requests.
Steve Drake – (760) 415-6470 mobile

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