Norland Optical Adhesive 161H is an adhesive that will cure optically clear when exposed to long wavelength ultraviolet or visible light (blue-violet) or heat. The adhesive has low viscosity.  NOA 161H is recommended for bonding glass or plastic. NOA 161H is cured by ultraviolet light between 315 to 400 nanometers and visible light between 400 to 450 nanometers. The peak absorption wavelengths are 325, 365 and 400 nanometers. Minor absorption wavelengths are 410 and 420 nm. Full cure requires 6 Joules/cm ² .

In addition to the UV cure, NOA 161H contains a latent heat catalyst that can quickly cure areas that do not see the ultraviolet light. The catalyst allows the adhesive to cure in 10 minutes at 125°C in a convection oven, or 3 hours at 80° C. Faster cure times are possible with infrared ovens. Areas in contact with air will cure tacky unless exposed to UV light or given the 125° C cure. Temperatures less than 80°C will not activate the adhesive. The advantage of the heat cure is to bring partially cured adhesive to full cure to get the maximum physical properties of the adhesive. The heat cure is not required if all the adhesive receives proper exposure to UV or visible light

NOA 161H can withstand temperatures from -125C to 125C.

Typical Properties of NOA 161H

Spectral Transmission of NOA 161H
(One mil film thickness)
nm %T
750 89.2
700 89.0
650 88.8
550 88.2
500 87.6
450 86.6
400 80.6
350 58.4
300 19.4

Shelf life of the liquid is a minimum of 6 months from the date of shipment if refrigerated and kept in a dark place in the original container, refer to the package label for the actual expiration date.  Allow the adhesive to come to room temperature prior to use.

Care should be taken in handling this material. The Material Safety Data Sheet should be read for this product. Prolonged contact with skin should be avoided and affected areas should be washed thoroughly with copious amounts of soap and water. If adhesive gets into eyes, flush with water for 15 minutes and seek medical attention.

The data contained in this technical data sheet is of a general nature and is based on laboratory test conditions. Norland Products does not warrant the data contained in this data sheet. Norland does not assume responsibility for test or performance results obtained by users. It is the users responsibility to determine the suitability for their product application, purposes and the suitability for use in the user's intended manufacturing apparatus and methods. The user should adopt such precautions and use guidelines as may be reasonably advisable or necessary for the protection of property and persons. Nothing in this technical data sheet shall act as a representation that the product use or application will not infringe a patent owned by someone other than Norland Products or act as a grant of a license under any Norland Products Inc patent. Norland Products recommends that each user test its proposed use and application before putting into production.