Are Nano Carbon Inks Ok With Celluloid?

[Megaloblatta]

I have just bought a vintage vac-filler with a translucent celluloid (celluloid nitrate) barrel and wondered if anyone knows whether Sailor Kiwa-guro or Platinum carbon ink might stain the barrel? I read on Richard Binder's website that "Strongly alkaline inks can eat some organic resins, especially celluloid", however, I don't know what pH these inks are (I have searched unsuccessfully for the information on the Web). Does anyone know their pH? I have used Kiwa-guro for several years in demonstrator pens I have and there has been no staining or clogging, even though I may only clean them out once a year at most!

[Chrissy]

Japanese inks are usually considered to be within the "strongly alkaline" category

[Megaloblatta]

Japanese inks are usually considered to be within the "strongly alkaline" category

 

Isn't "Japanese inks" a big generalization though? Nano carbon inks are very different to dye based inks. Would be great if someone has actually measured the pH of them.

[Chrissy]

From Richard Binder's pages and reproduced on Indy-Pen-Dance.com: Report on PH of more than 60 inks

 

Sailor Sei-boku is 8.61. That's the closest I can get to your specific inks. There aren't any Sailor, Platinum or Pilot inks mentioned in the below PH 7 list.

 

If you search on Richard's web-site for PH of inks, it's there in his glossary

[Megaloblatta]

Just found that Pilot Black is 9.17! See in description of https://youtu.be/hr462GM6GhM

[Torrilin]

Ok, I feel obliged to mention that p.H ranges from 0 to 14, with 7 being neutral. I don’t have any offhand data on how basic/alkaline any foods are, but many foods have a p.H of 5, so I’d guess there’s at least some going up to 9ish. Also, p.H by itself doesn’t mean a lot. If you just know it’s a 5 or a 9, it could be safe or it could give you chemical burns. You just don’t know.

 

With celluloid in particular it’s known that it’s not stable and there’s not a good way to predict when it’ll go weird. There’s nitroglycerin involved in the chemical structure, but I’m not clear on the decay process. It’s possible the “go weird” part is more likely in a basic environment, but if you’re really worried you should check out the chemistry in detail. I’m not joking about the go weird part, it’s visually very dramatic. And dramatic reactions tend to get studied a lot.

[Megaloblatta]

I asked the same question on Reddit and received the following helpful answer: "According to Syumi no Bungubako Vol.11 (a Japanese pen magazine), Kiwaguro is pH 6.89 and Platinum Carbon Ink is 7.74. I use Japanese pigment ink in my modern pens and never had problems, but I would hesitate to use them in a vintage pen that is not replaceable."

[FPFan]

Personally, I would only use it in cartridge/converter pens and not things like pens with bladders such as Parker 51 and the like. But in the long run, the biggest problems would be particle build up in the feed and between the feed and nib. Cleaning would be recommended regularly with a mild pen flush. I only use the carbon inks in Japanese made pens such as Sailor, Platinum, and Nakaya!

[Megaloblatta]

I have now been using Sailor Kiwa-guro ink in a vintage vac-filler with a translucent celluloid (celluloid nitrate) barrel for 5 months. I haven't cleaned the pen during this time and have filled it several times. It has pretty light use - mainly to write shopping lists, so the ink sits around in the pen for a long time between fills. Anyway, the good news is that there has been absolutely no clogging and no staining of the barrel. I love this ink!