Ink Recipe Research

[Cathedrow]

I thought I'd have a go at ink design. I'm no chemist (yet), but I've got a hankering for UV reactive inks. They're a rare thing on this side of the atlantic, thanks to all you americans keeping Nathan so busy! I've had some interesting results from research so far, so I thought I'd share to avoid duplication of work.

Patent search:

I couldn't find many fountain pen ink recipes. The search was complicated by the facts that fountain pen ink used to be called "Writing fluid" or "Writing ink", and ball point pens used to be called fountain ball pens.

I did find the following recipes though: US46684, US1848077, US1932248, US1972395, US2476991, US2493724, US2555474. That list includes some attempts at biocides, pH neutral, water-fast and anti-forgery inks.

Ink properties:

Chad Labs have some details

• Viscosity 1-1.25cps at 25'C
• Surface tension 42-48 dynes/cm
• pH 4-8 at 25'C (Noodlers: pH 6.8 - 7.9)
• Specific gravity 1.002-1.1035 g/cc at 25'C
• Optical properties (of course!)
• Low corrosion to pen materials (stainless steel, silver, gold and plastics)
• Resist mold growth
• Liquid or sol (colloidal suspension, pigment particle size much less that 1um)
• Flushable from pen - leave only water soluble residue.
• Low abrasion

Similar inks:

I also notice ink jet ink has quite similar properties to fountain pen ink.

US5085698 specifies ink jet ink as having

• viscosity 3.2 cps
• surface tension 45.5 dyne/cm
• pH 8.9.

So some ink jet recipes might be adaptable to fountain pens. However, I notice ink jet inks often include acrylics and solvents that would need removing.

Some capped marker highlighter inks have similar properties to fountain pen ink:

• Viscosity 2.8-4.8 cps at 25'C (a bit high)
• Specific gravity 1.07 - 1.11 g/cc
• pH 5-7 at 25'C
• surface tension >35 dynes/cm

[Intellidepth]

Welcome to FPN. Great topic and interesting patents.

 

That first patent is adorably quaint.

 

I'll follow your thread with interest and curiosity as I've played around with ink viscosity briefly at the domestic level, but have no knowledge of ink manufacture at all.

 

I'm happy to contain my mixology to ink colours rather than formulations and observe your exploration and experimentation from the sidelines. Having phenol in my house is enough right now.

[Cathedrow]

Thanks. This is really coming from the urge to scratch an itch. I've got a lot of things I'd like to try in inks - strontium aluminate (phosphorescent, but abrasive), quantum dots (can be fluorescent, invisible and light-stable - but hard to make and toxic), histology stains (lots of colours, waterproof), sheens and glitters, water resistance, anti-fraud etc. And even if those inks can't be made at home, it would be nice to at least understand why.

 

It appears that a colloidal mill capable of grinding down to 2μm are within a hobbyist budget, so that is an encouraging start for playing with pigments.

 

A lot of research to do!

[Intellidepth]

My eyes just went googly-looking. This sounds Awesome.

 

No doubt you've already found these threads, but if not...

 

Some of FPNers' successes, trials, tribulations and wisdom re DIY glitter/luster in ink:

https://www.fountainpennetwork.com/forum/index.php/topic/277454-experimenting-with-gold-powder/

 

Luster available from here (no affiliation) or its distributors:

https://www.ckproducts.com/categories/311/-Previously-Luster-Dust-Designer-Luster

 

Xanthan viscosity + glitter/luster experiments:

https://www.fountainpennetwork.com/forum/index.php/topic/283167-glitteratipearlmica-and-e415/

 

I remember that someone also linked to a commercial mica supply site - perhaps in the Experimenting with gold powder thread?

 

Histology stains sound fascinating. Solid permanency on paper that survives water drops without running is an elusive but sought after element by people who send snail mail. I've done a little research on it (excluding histology stains!) but it's beyond my ability as it seems to be linked in some respects to not only additives but also to the dye properties themselves and the form/medium of preparation.

Edited April 19, 2015 by Intellidepth

[Intellidepth]

You've prompted me to pull out my carboxymethyl cellulose and start another domestic experiment.

[musicman123]

Interesting patents! Super cool to see the work that went into inks back then!

[El Gordo]

You may want to check German patents as well, some of pretty recent date (although abandoned), in the last decade although Chinese patents pop-up (note that more than 95 % of the people on this earth live outside the USA...)

Also have a look at a number of discussion on this forum on the compatibility of fountain pens and pigmented inks. If you start milling down to 2 micron and use even smaller (QD) particles, use your PPE's.

Looking for recipes in patents is a good thing, take into account however that these are legal documents given you the right (if granted and maintained) to prevent other people from commercially exploiting your formulations, not science and technology reports. The claims can be quite broad and as you noticed it seems that one composition can be good for fountain pen ink, gel pens, markers, ink jet, ... . Weird.

Edited April 20, 2015 by El Gordo

[Cathedrow]

Thanks for the encouragement. I'm very much at the research stage now. I'm certainly not about to wade in.

 

My methodology for patents so far has been: Find a relevant patent, look for all the patents it refers to as prior art, plus all the patents that reference it (the parent and children if you will), and read those too. Then I'm discarding those that are less relevant. A few DE and UK parents have come up, but nothing relevant as yet - the european patents tend to describe just the invention, whereas the US patents give examples. El Gordo: If you've found any interesting patents, please post some links, and I'll research from there too, language barrier permitting.

 

I totally understand that learning from patents have some limitations - but with most academic papers locked behind a paywall, and a lot of trade secrets, patents are the most accessible way I've found of learning how inks are made with sufficient technical detail.

[El Gordo]

Well, you can't do much about trade secrets (I can imagine that the keepers of such secrets sometimes look here for some fun reading as well ...(or ideas...)).

 

For the academic works, it might help to search for the title and/or authors alone if you find something on a paying site. There might be pre-prints or other versions that covers the same or similar topic and that are made available at the researchers website. You could also contact the author directly. As you are "not a chemist (yet)", I assume you are planning or in progress to become one, so maybe you already have access to an old fashioned library with bound paper journals dating back to pre-computer times. Not everything is on the web.

 

I think discovery is half of the fun, so no direct links ... but as far as your strategy goes:

 

- seems OK, might want to limit searches with inclusion of patent classes as well (could be good as a start, but for one reason or another it makes one miss a lot as well). In case you have not discovered it yourself: http://www.uspto.gov/learning-and-resources/support-centers/patent-and-trademark-resource-centers-ptrc/resources/seven

 

- Noticed you use Google Patents, has some nice features, but you could also use http://patft.uspto.gov/netahtml/PTO/search-adv.htm for US or EU/World http://worldwide.espacenet.com/advancedSearch?locale=en_EP (published applications from 90+ countries). Don't worry too much about the different languages: for example if you search in the latter for "fountain pen ink" in the title or abstract and "CN" (China) in the publication number, the fourth (of 699) is a Chinese (obviously) publication, but the abstract (in English) has a description of the formulation.

 

So, hope this is not all already known, and happy hunting with your patent landscaping.

 

PS there is nothing exclusively American about UV reactive inks, they only make more fuzz about everything ...

 

For only one example (not affiliated) http://www.chemstream.be/inkjet_inks.html (OK not fountain pen inks) or http://www2.fhi.nl/labautomation/archief/2009/images/guido%20desie.pdf (not affiliated to the presenter's company)

[Cathedrow]

" I assume you are planning or in progress to become one" - alas not. I've got my certificate on the wall for electronic engineering, and this is very much a hobby interest. I hope I'm not spoiling anyone's fun by posting the recipes I find - my intention is very much to save someone else repeating the same chores that consume so much of my valuable spare time.

 

One of my aims is a home-brew UV reactive ink like Blue Ghost. I've just found this patent, US20050099475. It may be an inkjet ink, but it looks adaptable by dropping the alcohol content, and it is not only safe but edible. Riboflavin or quinine are the food safe dyes. Riboflavin is particularly easy to obtain - it's available pure as a dietary supplement.

One recipe in that patent is:

• Solvent: water
• Surfactant: ethyl alcohol
• Buffer: sulphuric acid
• Edible colourant: quinine sulphate

Substitute sulphuric acid for citric acid, tweak the proportions, and that sounds very much like a recipe for gin and tonic. Cheers!

[musicman123]

" I assume you are planning or in progress to become one" - alas not. I've got my certificate on the wall for electronic engineering, and this is very much a hobby interest. I hope I'm not spoiling anyone's fun by posting the recipes I find - my intention is very much to save someone else repeating the same chores that consume so much of my valuable spare time.

 

One of my aims is a home-brew UV reactive ink like Blue Ghost. I've just found this patent, US20050099475. It may be an inkjet ink, but it looks adaptable by dropping the alcohol content, and it is not only safe but edible. Riboflavin or quinine are the food safe dyes. Riboflavin is particularly easy to obtain - it's available pure as a dietary supplement.

 

One recipe in that patent is:

 

• Solvent: water
• Surfactant: ethyl alcohol
• Buffer: sulphuric acid
• Edible colourant: quinine sulphate

Substitute sulphuric acid for citric acid, tweak the proportions, and that sounds very much like a recipe for gin and tonic. Cheers!

Wait isn't Quinine an anti-malarial drug? So the ink will end up preventing malaria as well?

[Cathedrow]

Wait isn't Quinine an anti-malarial drug? So the ink will end up preventing malaria as well?

Theoretically! (Although, of course, UV ink, a G&T and the malaria treatment all have very different concentrations of the ingredients).

[El Gordo]

" I assume you are planning or in progress to become one" - alas not. I've got my certificate on the wall for electronic engineering, and this is very much a hobby interest. I hope I'm not spoiling anyone's fun by posting the recipes I find - my intention is very much to save someone else repeating the same chores that consume so much of my valuable spare time.

 

One of my aims is a home-brew UV reactive ink like Blue Ghost. I've just found this patent, US20050099475. It may be an inkjet ink, but it looks adaptable by dropping the alcohol content, and it is not only safe but edible. Riboflavin or quinine are the food safe dyes. Riboflavin is particularly easy to obtain - it's available pure as a dietary supplement.

One recipe in that patent is:

• Solvent: water
• Surfactant: ethyl alcohol
• Buffer: sulphuric acid
• Edible colourant: quinine sulphate

Substitute sulphuric acid for citric acid, tweak the proportions, and that sounds very much like a recipe for gin and tonic. Cheers!

Wow, an electronic engineer with a passion for chemistry, rare bread ...

Not sure about the choice for sulphuric acid however (if you would be looking for inks for paper that would keep some long time (https://www.uni-marburg.de/bis/ueber_uns/projekte/dfgtinte/zustandsklasse), maybe you could start from your gin tonic and experiment, sounds like a good excuse ...

Edited April 26, 2015 by El Gordo