Phenolic Resin
Definition
A class of synthetic polymer binder formed by condensation of phenols with formaldehyde; used in ballpoint ink vehicles since the 1950s; identifiable by FTIR carbonyl absorption at 1700-1720 cm-1.
- Chemistry
- Phenol-formaldehyde condensation polymer
- Use
- Binder in ballpoint ink vehicles since the 1950s
- Detection
- FTIR carbonyl absorption at 1700-1720 cm-1
- Polymer class
- Thermosetting synthetic resin
Common questions
Why does an ink examiner care about the resin, not just the dye?+
The resin binder controls how the ink flows, dries, and ages on paper, so its FTIR signature can help place an ink formulation within a manufacturing era or narrow down a brand, independent of the colorant used.
Can phenolic resin alone date a document?+
No; its presence only confirms a ballpoint ink consistent with post-1950s manufacture. Dating a specific writing to a date range needs solvent-loss or other comparative methods layered on top.
How is the FTIR carbonyl peak used practically in casework?+
An examiner compares the carbonyl absorption position and shape of a questioned ink against a reference library or a known-source ink, since resin formulation differences shift the peak and help discriminate between similar-looking inks.
Related terms
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- The Bundeskriminalamt (German Federal Criminal Police Office) reference database of European pen ink formulations, used as the evidentiary baseline for questioned-document cases...
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- USSS International Ink Library
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