Chemical Formulas

[chadden42]

My daughter (junior in high school) is doing a physics project on some types of pens and pencil. Her teacher requested she get some chemical formulas of ink. She is thinking of comparing/contrasting fountain vs roller vs ballpoint formulas. Do any of you have suggestions on resources to find this info?

 

Thanks

[WirsPlm]

There's a free ebook on the history of ink that might be useful called Forty Centuries of Ink, and Wikipedia has a fairly extensive discussion of the makeup of various inks, there's also several free, old ebooks from Project Gutenberg and Archive.org that provide household recipes or industrial recipies from periods when making personal ink was common which might be useful, modern ballpoint ink uses petroleum and not water and is still mostly proprietary so there's less public information about that I think.

[dcwaites]

Up until the mid 1800s, the most common ink used was iron-gall or ferro-gallate ink. The chemistry of this ink, as it changes while it dries, is quite interesting.

Other than that, many ink dyes are based on coal-tar chemistry, and are generally sourced from the Textile and Food Dye industries.

 

Your daughter might also want to look up the chemistry of a couple of specific dyes like Alizarin and Indigo, while she is looking up the chemistry of iron-gall/ferro-gallate ink and coal-tar dyes.

 

As far as I know, the dyes used in ballpoint ink are generally the same as used in fountain pens, just with different solvents and binders.

 

Also the MSDS (Material Safety Data Sheet) documents for various inks (Parker Quink, Sheaffer Skrip, etc) may be useful.

[JustWrite Pen Company]

I'm not sure if this helps, it's more a list of ingredients than an actual formula. I think you'll find actual formulas are closely guarded trade secrets. Another place to search is Google Patents https://www.google.com/?tbm=pts

 

Modern Fountain Pen Ink

Colorant: 1 - 15% (Water soluble dyes mainly but some inks contain small quantities of pigments)

Humectant: 2 - 5% (Prevents evaporation)

Fixer/Penetrant: 0 - 5% (Assists ink to penetrate paper fibres and 'fix' the ink)

Surfactant: 0.1 - 6% (Reduces surface tension allowing ink to flow more freely)

Preservative: 0.01 - 0.4% (Prevents bacterial, fungal and mold growth in ink)

Buffer: 0.05 - 1% (Adjusts pH level)

Lubricant: 0 - 0.5% (Lubricates contact between pen and paper to provide a smoother writing experience)

Water: 75 - 95% (Solvent)

 

Not every ink contains all of these ingredients and some inks contain other 'magical' ingredients that give ink unique qualities.

 

I believe ballpoint ink is very similar with a spirit based solvent used instead of water and rollerball inks use either water or spirit.

[MisterBoll]

I'm not sure if this helps, it's more a list of ingredients than an actual formula. I think you'll find actual formulas are closely guarded trade secrets. Another place to search is Google Patents https://www.google.com/?tbm=pts

 

Modern Fountain Pen Ink.........

 

Thank you Kevin for a good intro/info to this subject.