Re: virus: post-its
Sun, 17 Mar 1996 11:30:32 -0500

In a message dated 96-03-15 21:01:42 EST, you write:

>>I have been told that the glue from post-it notes never entirely
>>comes off the paper they've been attached to, and will
>>damage books over time. If you like a book enough to flag
>>it, you probably like it enough to want to preserve it. Use plain
>>paper bookmarks.

I have tested the monomer used for 3M Brand Post-It notes using the NIST
accelerated aging protocol and have not found a problem. Paper's acid
content is far more of a factor, both of the Post-It and the document.
Finger prints rapidly damage paper with more acid. Alkaline pH buffered
paper is the most resistant. The dyes used in Post-Its seem to be unstable
and I have seen them diffuse into the document on the opposite side of the
glue. Ironically the glue side seems to resist the dye penetration. The
length of the fiber content of the document is a factor. The accelerated
aging study used heat and the shorter the fibers, the faster the brittling.

The monomer used for Post-Its is in the crossover area on the aggressiveness
curve between the weak (falls off the document) and aggressive (3M "Scotch
Brand Magic Transparent Tape). The bonds of the glue and the fiber breaks at
the fiber junction leaving behind very little, if any monomer. This
depends on the fiber and temperature, humidity, etc. Post-It notes were
originally developed when a need was observer for bookmarking religious
hymnals in Minneapolis by a 3M research and development scientist. He wanted
a monomer that was "permanently temporary" and the document stability studies
conducted at that time confirmed this. The only improvement I would suggest
to 3M is using acid-free, alkaline buffered paper, NOT changing the monomer.

Davin C. Enigl, MS, MEAS
Senior Microbiologist, Consultant
HACCP Validations-sm
Hazard Analysis and Critical Control Point Validations
For the Food, Cosmetic and Pharmaceutical Industry
March 15, 1996
6:27 pm