|Kodak Park in Colorado|
And, since Polaroid kept much of the receiver design a secret, the only book-form reference we have is the Focal Press book by Andre Rott and Edith Weyde entitled, "Photographic Silver Halide Diffusion Processes", and certain of the early Edwin H. Land essays, such as published by McCann, particularly Volume 1, "Polarizers and Instant Photography". Then there are several patents, long expired, that hint of certain tips, tricks and practical implementations of "the receiver". These are, by far, the most valuable to us, and it is good that the companies concentrated on patents, which as you know have a limited lifetime, so anyone, including you, can now use them.
|Very small clumped and dispersed nanoparticles|
Aqueous Coatings vs Solvent-Based Coatings
There are thousands of coatings and many techniques for coating sheet products such as paper, plastics, films and fabrics. We need to coat baryta paper - the paper that is normally used for photo prints - with the special materials mentioned previously to form the receiver sheet, and produce the positive print. Aqueous coatings, as the name suggests, are water-based. Water is a good and environmentally safer solvent for paints, for instance, and for things such as gelatin emulsions, candy, food, and printing. But solvent-based coatings have their own advantages: Oil paints use a solvent (volatile petroleum oils) to maintain a sticky, adhesive and semiliquid state. The solvent evaporates into the atmosphere. Other solvent-based materials contain alcohols, or light oils similar to paint thinner. Oil paints can be stronger, and tougher, and have other chemical advantages, but industrial coatings with solvent-based materials also require additional steps to capture and clean the evaporated solvents. Often this is termed "solvent recovery".
Our detective work tells us that traditional receivers are made of both aqueous (water) and solvent based materials, which have to work together to form the nucleating layer. Sounds complex? Yes it is. We are fortunate to have the experience of coaters, some who were with Kodak, Polaroid and other important firms in the coating business, to help us understand the manufacturing tradeoffs as we near decision points on the processes needed to produce New55 FILM. Even they, however, find this field of coated nanoparticles something they will have to learn about, too.
Secrecy is needed in industry, this we understand, and trade secrets are essential to keep. But when companies die, the knowledge can, and often does die. Look at the many industries and technologies from the Roman Era until today - medicine, surgery, navigation, pigments, gold plating, and many many more - that were lost because nobody dared write down how to do it out of fear of copying. It was not until the 18th Century when patents allowed inventors to bring forth their ideas for public review in return for 20 years of exclusivity, and look at what happened since then. But not everything to be known is written, and it certainly is not on the internet, or google searchable.
So that was the subject-of-the-week, amid many sourcing and vendor efforts, phone calls, visits, quotations and buying the things we need to finalize the design. Onward.