CompuServe Messages

Kodak CD Permanence

    24-Mar-93 12:59:06
Sb: Kodak CD Permanence
Fm: Paul McAfee [Kodak] 70007,6241
To: ALL
The following will be part of our Intermedia press kit next week. March 1993 Eastman Kodak Company, 343 State St., Rochester, NY 14650 PERMANENCE OF KODAK WRITABLE CD MEDIA WITH INFOGUARD PROTECTION SYSTEM (Note: This also applies to Photo CD discs.) As new applications for writable CD products are identified and implemented, the issue of permanence of information recorded on CDs must be addressed. As with other information-recording media, including photographic film, magnetic tape, and optical discs, different manufacturers produce products having different quality, reliability, and lifetime properties. It is important that customers carefully select their suppliers. Kodak manufactures Kodak writable CD media with InfoGuard protection system using different materials and manufacturing processes than are used for mass produced audio or data discs. The reflector Kodak uses is gold, a material that is not adversely affected by moisture, oxygen, or solvents. The data-recording layer Kodak uses is a carefully selected laser-sensitive dye that does not change significantly over time, even when exposed to extreme light, heat, and humidity conditions. Kodak knows there are wide variations in composition of the dye layers used by various media manufacturers. Information stability characteristics in other manufacturers' media vary widely and can be linked to different types of dyes used in their discs. In our testing, we observe no significant changes in any performance characteristics of Kodak writable CD media with InfoGuard protection system after 32 days of continuous exposure to 50 Klux of simulated daylight (sunlight filtered through window glass). This corresponds to more than 100 years of exposure to indirect indoor sunlight. Indoor indirect sunlight is what a disc experiences when left on a desk or shelf in a well-windowed room. Similar results were obtained in our tests for discs exposed to high temperature (up to 176~ F/80~ C) and high humidity (up to 85%). It is not possible to accurately predict an expected data lifetime based on these results because the changes we observe are so small, even after prolonged testing. It is reasonable to expect a life of 30 years or more when discs are stored in normal home or office conditions. We are continuing our testing, covering many production lots of material, under many different testing conditions. Additional results will be reported when testing is completed. It is important to note that any accelerated tests are predictions that must be confirmed in real-life keeping tests. Kodak writable CD media with InfoGuard protection system also has been specially treated to minimize damage caused by handling. Our scratch tolerant surface resists damage even when subjected to forces twice as great as those that would cause data loss on conventional CDs and five times greater than those that would cause data loss on some other recordable CD media. This results in a product with excellent physical durability. ### [Note: Kodak and InfoGuard are trademarks.]