Inks that don't dry out / Infinity Inks

[ferrogallic]

Any thoughts what could be the concept behind slow evaporating inks, like e.g. Private Reserve Infinity? 

 

Some ideas:

• use > 20% glycerol. 
  • Downside: Ink will smudge
• other humectants
  • sorbitol, urea, LiCl
  • If it is too hygroscopic, the ink will never dry. LiCl will dissolve in its own water.
• use 2 separate humectants, e.g. glycerol + urea.
  • Not sure why this doesn't smudge
  • patent here: https://patents.google.com/patent/JP4722462B2/en
• Evaporation suppressing monolayers, e.g.  octadecan-1-ol (stearyl alcohol, very common in hair conditioners) will slow down evaporation by about 50%. Ethylene glycol monooctadecyl ether will slow down the evaporation by 10x.
  • These would be ideal, if one could get them through the feed. Downside is they have very low water solubility. Maybe it doesn't matter, as only tiny amounts are required
  • Commercial products for pools are WaterSavr, AquaGuard, CoverFree, which is supposed to reduce evaporation by 85%
  • Could disperse in ink, potentially together with surfactant
• Use a water-soluble polymer that might concentrate near the surface and act similarly to the monolayer
  • Does PEG have such an effect?
  • PVA, PVP, ...
• Combination of polymer + surfactant
  • This patent shows a drawing of polyacrylic acid acting together with one of the monolayers above.
  • Other polymers mentioned:
    •  soluble polymer may include a homopolymer or copolymer derived from at least one compound selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, N-alkyl acrylamide, glycerol, ethyleneimine, ethylene oxide, vinyl pyrrolidone, vinyl acetate, the hydrolysis products of vinyl acetate, 2-hydroxyethyl acrylate, maleic acid, maleic anhydride and dimethylaminoethylacrylate.
• Nonionic surfactants might have a good balance between solubility and forming a layer on the surface
  • some compounds to try:

    • Ethoxylates, such as octaethylene glycol monododecyl ether, laureth-4, ...

    • Triton X

[ferrogallic]

I found a good overview of evaporation suppressing monolayers in this patent: Composition and method for suppressing water evaporation and heat loss

 

This patent number is printed on the bottle of Cover Free Liquid Blanket and suggests using Laureth-2, but the SDS for the product states the ingredient is octadecanol,

 

I did not find any supplier, these substances are made on an industrial scale, but don't seem to be available easily to end users.

 

Is anyone here working in the industry with access to these kinds substances?

 

Quote

 sold under the tradename of Hetoxol L-2. ... Polyoxyethylene (2) lauryl ether is also referred to as Laureth-2 (INCI Nomenclature, International Nomenclature of Cosmetics Ingredients, formerly the CTFA Dictionary), PEG-2 Lauryl Ether and others. It is assigned CAS Numbers 3055-93-4, 9002-92-0(g), EINECS Number 221-279-7 and is reported to have a calculated HLB value of 6.1 and is generally liquid at a temperature of 25 degrees C.

 

Quote

The use of long-chain, solid, aliphatic fatty alcohols, particularly of chain length C₁₆ and C₁₈, commonly known as, respectively, cetyl alcohol and stearyl alcohol, are known in the prior art for suppressing water evaporation. However issues with dispensing these materials present hurdles to their use in practice under actual use conditions. Attempts to overcome these hurdles have involved a number of approaches. The prior art teaches the need to combine these materials with solvents and dispersants or spreading agents to make their use practical under actual use conditions. These prior art compositions involve heating, combining and dispensing materials at high temperatures (between about 70 degrees C. to about 100 degrees C.). Compositions are delivered as dispersions, emulsions, solutions or solids.

U.S. Pat. Nos. 4,162,990 and 4,250,140 teach that the smallest chain length that can seriously be regarded as an evaporation retardant is C₁₆. Surprisingly, the present inventors find that Laureth-2 with a carbon length of C₁₂ performs unexpectedly well for suppressing water evaporation and heat loss.

Reiser (U.S. Pat. No. 3,528,764) discloses a method and apparatus for retarding water evaporation from water surfaces through the use of solid fatty alcohols delivered as a dispersion. Alternatively an emulsion can be formed from the dispersion by including a surfactant such as ethoxy derivatives of fatty alcohols. The inventor specifically indicates a preference to use a fatty alcohols having from 16 to 18 carbon atoms.

O'Brien (U.S. Pat. No. 6,303,133 B1) discloses a composition that forms a monolayer to suppress water evaporation, comprising an aliphatic alcohol component having from C₁₂-C₂₄ and powdered calcium hydroxide. Cetyl alcohol and octadecanol can be used; cetyl alcohol (hexadecanol) having a chain length of C₁₆ is preferred.

Rowlette (U.S. Pat. No. 4,162,990) discloses using a polyethylene glycol that is soluble in both water and the fatty alcohol (such as docosanol, docosanoic acid or octadecanol) as a spreading agent for the fatty alcohol on the surface of a body of water. The particles are mixed with particles of a filler material capable of generating a gas upon contact with water.

In U.S. Pat. No. 4,250,140 Rowlette discloses using a polyethylene glycol, such as those in the CARBOWAX® series (Registered trademark of Union Carbide Chemicals & Plastics Technology Corp., Danbury, Conn.), as a spreading agent for a film-forming agent. This patent states that C₁₆ is the smallest chain length that can seriously be regarded as an effective evaporation retardant.

U.S. Pat. No. 3,531,239 indicates that various fatty alcohols, such as octadecanol, hexadecanol, nonadecanol, and pentadecanol could be used as evaporation retardants for water although the inventor states that a chain length from C₁₆ to C₁₈ are generally preferred.

Egan (U.S. Pat. No. 3,415,614) discloses the addition of a heterocyclic, 5-membered ring compound, one of which is oxygen, to at least one solid aliphatic alcohol ranging from C12-C20, to form a solid, self-dispersing composition. The aliphatic alcohols include myristyl, cetyl and stearyl alcohols and mixtures thereof. The most preferred composition comprises cetyl and stearyl alcohols which retards evaporation by about 30-40%.

In U.S. Pat. No. 3,391,987 Myers discloses compositions using water-soluble saccharides as carriers for the fatty alcohols where hexadecanol and octadecanol with chain lengths C16 and C18 are especially preferred. Unsaturated alcohols such as oleyl alcohol may be used, but are not preferred.

Cox (U.S. Pat. No. 3,257,162) discloses glycol esters, glycol amides and ethoxylated amides and ethoxylated derivatives thereof that are effective in retarding evaporation of aqueous solutions of normally volatile organic substances.

In U.S. Pat. No. 3,959,154 Cox discloses agents to retard the evaporation of ammonia and amines from essentially aqueous solutions by adding thereto an alkyl ether having the formula:
R—(O[CH₂]_y)_n—R′
where

R is an alkyl group containing from 8 to 30 carbon atoms, and

R′ is an —OH or —NH₂ group,

y is an integer of 2 to 4; and

n is an integer of 1 to 10.

The inventor notes that the utility of these compositions is predicated on the fact that they effect the evaporation of dissolved ammonia or amines to a far larger extent than their effect on the evaporation of water.

In U.S. Pat. No. 2,903,338 Dressler discloses the use of finely divided and wetted/suspended fatty acid alcohols, preferably C₁₆ to C₁₈, dispersed in water or emulsified with sodium lauryl sulfate or sodium dodecylbenzene sulfonate to form a film that leads to a reduction in water loss by evaporation.

Malkemus (U.S. Pat. No. 3,036,880) discloses the use of ethylene glycol and propylene glycol monoesters of long chain fatty acids to form films on the surface of water. The patentee notes that the fatty acid must have at least 14 carbon atoms since esters from the lower acids do not appear to offer any advantages. Benzene is the preferred solvent.

In U.S. Pat. No. 3,146,059 Suzuki et al. disclose the use of derivatives of aliphatic alcohols with carbon chain lengths of 22 to 16 or docosanol to cetanol in compositions for retarding water evaporation. The claims are addressed to longer chain structures, having the general formula:
CH₃—(CH₂)m-O—(CH₂—CH₂—O)n-H
where m is 15-21; and

n is 1-5,

which may be mixed with a compound such as urea, salts of carboxymethylcellulose or alginic acid. Fatty alcohol derivatives of this invention with 1 mole of ethylene oxide showed an average reduction in the evaporation rate of water of 56%, 22%, 6% respectively for C₂₂, C₁₈, C₁₆. Furthermore, evaporation rate reduction decreased from an average of 56% for 1 mole of ethylene oxide to about 9% for 5 moles of ethylene oxide. Taken together these results clearly indicate that the expected effect on the evaporation rate of water for ethoxylates of fatty alcohols with a carbon chain length less than C₁₆ would be close to zero! Thus it would be very surprising and unexpected that a fatty alcohol ethoxylate with a carbon chain length of C₁₂ and 2 moles of ethylene oxide, such as Laureth-2 would have any effect on the evaporation rate of water.

Mazur (U.S. Pat. No. 3,241,908) discloses a method for preparing a monomolecular film former for controlling evaporation from water surfaces, using fatty acid alcohols such as n-hexadecanol and n-octadecanol, which show a 25-35% reduction in the evaporation rate of water.

In U.S. Pat. No. 3,437,421 Harwood discloses the use of long chain aliphatic alcohols as agents for retarding water evaporation and a method by which solid long-chained alcohols are liquefied by heating and then sprayed onto the surface of a body of water. The preferred compounds were the C₁₆ and C₁₈ compounds hexadecanol and octadecanol; unsaturated alcohols, such as oleyl alcohol, had a lower efficiency than the saturated alcohols.

In U.S. Pat. No. 3,650,980 Gothel et al. disclose a film forming composition to retard evaporation loss that comprises a higher alkyl alcohol and up to three weight percent of an ortho-silicic acid ester of an ethoxylated alcohol. Ethoxylated lauryl- as well as stearyl-alcohols are stated to be of restricted applicability as non-ionic surfactants.

Hall (U.S. Pat. No. 4,172,058) discloses the use of a mixture of hexadecanol and octadecanol, both as a mixture of liquids, or a dry mixture thereof, as a composition to retard evaporation of fluid from an aqueous mixture containing “H-SPAN”, a hydrolyzed starch-polyacrylonitrile graft copolymer.

In U.S. Pat. No. 4,707,359 McMullen discloses the use of fatty acid alcohols in conjunction with an insecticide to form a layer on a water surface and kill insects, such as mosquitoes. The particular compounds are described in Great Britain Pat. No. 1,557,804A, with the composition including an oleyl poly-ethoxy, poly-propoxy mixed ether. The composition may include a solvent, such as water, kerosene, hexane deiselene, heptane and gas oil.

Koester et al. (U.S. Pat. No. 4,932,994) disclose a paraffin-containing aqueous dispersion or a self-emulsifying solution in an organic solvent, to form films on the surface of water.

In contrast to the prior art compositions, embodiments of the present invention utilize polyoxyethylene alkyl ethers with carbon chain lengths less than C₁₆ as the active agent. For example, polyoxyethylene (2) lauryl ether is a polyoxyethylene lauryl ether having a carbon chain length of C₁₂ with 2 moles of ethylene oxide which performs unexpectedly well for suppressing water evaporation and heat loss. Furthermore, because it is a liquid at ambient conditions and is self-dispersing, it can be used as is, without the need for any further processing, without the need for any added solvents, carriers, dispersants or spreading agents, and without the need for any specialized equipment for application.

 

 

[amberleadavis]

Wow, this is a lot of work you have done.  I am sorry no one has responded..

[ferrogallic]

Thank you for the kind words!

 

Using chemical substances to reduce evaporation in reservoirs seems to work pretty well, many tests have shown to reduce evaporation by 50-80%. There are also couple of products on Amazon for home pool use.

 

These agents have slightly different constraints: they can't be soluble at all in water so they stay on the surface only. This allows to cover e.g. a 1 acre reservoir with only 100g of cetyl alcohol.

Here is how such a layer looks on a lake:

 

 

The ideal compound for an ink would be slightly soluble instead, so it could travel with the ink through the feed and then cover the ink in the feed to prevent it from drying out. It wouldn't matter if we'd need slightly more.

 

But maybe the product doesn't need to be mixed in with the ink and a tiny blob somewhere on the nib or the feed would slowly spread out across the free surface in the nib.

 

This would be the holy grail of inks, because the ink would still dry very quickly once absorbed onto paper.

 

Probably none of this is new and e.g. inkjet inks have solved the evaporation issue. I read that some use Dowanol glycol ethers as humectants, not sure how these compare to glycerine.

 

Maybe the Infinity Ink E.C.O. (Extended Cap Off) technology is based on something common in inkjet inks?

 

Hopefully someone who knows more about this topic will comment.

 

 

 

 

[lotharn]

I'm not really sure about the nanotechnology part of things, but a thought did occur, it could be that the private reserve formula draws water from the air, itself being hygroscopic, and thus never actually dries at all. it may be that it fully saturates the paper fibers to a degree that it is effectively dry.

[ferrogallic]

I'd suspect it would smudge, but maybe if the solution contained something that helped it to penetrate the paper fibers?

Is there a way to make the ink penetrate better without causing it to feather excessively?

 

Looking at this table of deliquescent salts, MgCl2, LiCl, and potassium acetate would be good candidates to try:

 

A saturated solution of LiCl is 84g/100ml would still absorb water from the ambient air, maybe 20-40g is a good range to start. It would be ok if the ink loses some water on the nib, as long as the remaining ink stays liquid.

 

[lotharn]

be aware that increased solutes in water will increase surface tension, but balanced with surfactant, shouldnt matter too much. lithium chloride looks pricey. why isnt magnesium sulphate in this list? or for that matter calcium chloride/carbonate?

[ferrogallic]

@lotharn took me some time to find a value for CaCl2, 31% RH. So it should work, as well.

I didn't find a value for magnesium sulphate.

Potassium carbonate might barely work, a concentrated solution has 44% RH.

Zinc chloride should also work, but even more so than the other chlorides it is very corrosive.

[lotharn]

are you testing these formulations?

[lotharn]

to be frank, the amount of any water drawn from the atmosphere exposed by the surface area of a fountain pen is very small.