JPS61126186A - Non-corrosive impulse jet ink - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to the field of impulse inkjet inks, and more particularly to the field of impulse inkjet inks, and more particularly to the field of impulse inkjet inks having metallic materials in contact with such inks and exposed to corrosion thereof. This invention relates to the field of impulse ink jet inks for use in jet systems.

BACKGROUND [Prior Art] This invention is disclosed in U.S. Patent Application No. 331.604, filed December 17, 1981, entitled "Natural Wax Containing Inkjet Ink" (now U.S. Patent No. N).

No. 4,390,369), and Follow-on Application No. 507,918 (currently U.S. Pat. No. 4,484,948) filed on June 27, 1983 (both filed by the applicant of this patent application). ) related to

A wide variety of impulse ink jet inks have been suggested. As disclosed in the aforementioned related patent applications and patent specifications, these inks contain fatty acids such as oleic acid; a wide variety of colorants such as many dyes and some pigments; and solvents and solvent additives. aromatic alcohols, aromatic ethers, dimethyl sulfoxides, alkylpyrrolidones, methoxy- and ethoxy-triglycols, and aliphatic ketones, and especially n-methylpyrrolidone, benzidyl alcohol,
It can include benzyl ether, diethylene glycol, methoxy triglycol, and mixtures thereof.

In addition to the above, other practitioners in the art have suggested the use of seed materials in inks, including inks intended for some types of inkjet printing.

U.S. Patent No. 4, 197.135 (BaiJey et al.) describes a method containing water-soluble dyes and polyamines containing seven or more nitrogen atoms per molecule that is said to improve the water retention properties of inks used in inkjet printing. An ink is disclosed. Balley et al. further note that the absence of emine functionality is primarily to avoid azo dye composition reactions (this requirement would be met by the synthesis of bar-alkyl or bar-hydroxyalkyl substituted polyethylene amines). It is disclosed that the additives of the invention are to be distinguished from the polyethylene emines of the prior art. Preferred polyamines are disclosed in which the hydrogens of the primary amine groups are replaced by methyl or hydroxymethyl groups.

U.S. Patent No. 4.343,653 (Beach et al.)
discloses a jet ink comprising a Sulfur Black 1 dye, the solubilizing groups of which have been oxidized, for example by the use of hydrogen peroxide.

U.S. Patent No. 4, 382.946 (Unihara et al.) entitled "Ink composition for inkjet recording"
having an aqueous liquid comprising a water-soluble acid or a direct dye or a mixture thereof and further comprising higher alcohols having 1 to 6 carbon atoms, hexylene glycol, triethylene glycol, di-propylene glycol and 1,2.
An ink comprising a compound selected from the class of 6-hexanetriol is disclosed.

U.S. Pat. No. 4,409,040 (Tabayashi et al.) discloses various inkjet inks, including inks containing various solubilizers or wetting agents. In particular, Tabayashi suggests an ink comprising a water-soluble dye, a wetting agent, and a dissolution in water of polyethylene glycol phenol ether or a derivative thereof. Examples of disclosed humectants include polyhydric alcohols such as ethylene glycol,
Diethylene glycol, glycerin, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol; pyrrolidones, such as n-methylpyrrolidone and β-hydroxyethylpyrrolidone; low molecular weight alkylene imines, such as polyethyleneimine and polypropyleneimine; amino alcohols, such as monoethanol amine, jetanolamine,
Included are triethanolamine, N,N-dimethylethanolamine and aminoethylethanolamine; and amides such as formamide and N,N-dimethylformamide.

Other patents of interest in this field include U.S. Patent No.
3.282,852 (Bennett), No 4
, 108.671 (R3chlin), No 4 +
136+076 (Daniels), N.

An ink composition for inkjet recording is disclosed that consists essentially of a dye, water, a water-soluble dye, and an "oxygen absorber." Maxima states that when there is a large amount of dissolved air in the ink, as the frequency of pressure increases increases, ``the ink becomes more compressible fluid, and the movement of the pressure increases becomes more pronounced.'' It teaches "delay". Maxima therefore suggests that it is desirable to keep the amount of dissolved air at very low levels.

Physical or chemical methods have been suggested for removing dissolved oxygen, and this method uses metals such as iron pieces, sulfites, such as sodium sulfite, ammonium sulfite, and potassium sulfite to remove dissolved oxygen from the ink. , sodium bisulfite, potassium bisulfite, and ammonium bisulfite; polyhydric phenols such as pyrogallol, and other reducing agents such as sodium trithionide and hydrazine, and the like.

Although a variety of inks have been suggested for use in inkjet ink printing, inkjet inks that are easily jetted in impulse inkjet systems, yield high quality prints, and exhibit excellent material compatibility There remains a need to provide The selection of materials used in an inkjet printing system is very critical to its reliability and performance. When selecting hardware or ink materials, the interaction between the ink and the hardware is a major concern.

Most inkjet hardware consists of two primary materials: metals and polymers. Damage to metals is generally caused by corrosion, whereas damage to polymers is generally the result of defects in mechanical properties, such as swelling, embrittlement, softening and disintegration.

The inventors have discovered that metal corrosion can be predicted by electrochemical experiments such as electrostatic potential measurements or by weight loss. Water-based inks have higher conductivity than non-aqueous inks because water can ionize dye and salt impurities. Therefore, water-based inks are more corrosive. We have found that with the exception of a few highly ionized polar solvents such as acids or amines, corrosion is rarely caused by the ink vehicle alone.

[Summary of the invention]

This invention provides non-aqueous inks and inkjet systems in which chemical additives are used to help the inks overcome metal corrosion problems. In particular, the novel impulse ink jet inks of this invention comprise a fatty acid vehicle, a colorant, and an antioxidant in an amount effective to substantially reduce the rate of ink-induced metal corrosion. Preferred antioxidants comprising from 0.1 to 5% by weight, preferably from 0.5 to 5%, more preferably from 1 to 4% by weight of the ink of this invention are alkylated hydroquinones, such as Ler t-butylhydroquinone. .

It has been found that with the use of such antioxidants, the corrosion rate of nickel can be reduced to one-eighth of that of the ink without additives. This effect is particularly important in inkjet inks containing relatively high concentrations of high quality dyes.

Accordingly, a first object of this invention is to provide an improved inkjet ink for use with inkjet systems having materials that are subject to attack by the ink.

Another object of this invention is to provide an impulse ink jet system that exhibits reduced corrosion rates.

These and other objects of the invention will become apparent from the following more detailed description.

[Specific description]

This invention provides a new impulse inkjet ink for use with inkjet systems having materials that are subject to attack by the ink. The ink jet system of the invention therefore comprises ink supply means for supplying ink to an impulse ink jet head having a metal surface that is in contact with the ink to be jetted and is subject to attack by the ink. A preferred ink for use in this system comprises at least one fatty acid, a dye, and an antioxidant in an amount sufficient to substantially reduce the rate of corrosion of metal surfaces by the ink. In the systems of this invention, the inks of this invention generally contain medium to high molecular weight natural fatty acid vehicles, such as C6-C2
& a fatty acid vehicle, preferably oleic acid. This vehicle accounts for 10-97% by weight of the ink.

Preferred inks further include aromatic alcohols, aromatic ethers, dimethyl sulfoxides, alkylpyrobilines, methoxy- and ethoxy-glycols, polyethylene glycols, aliphatic ketones, and mixtures thereof. 10-90% by weight of selected vehicle additives. Preferred vehicle additives can be selected from the group consisting of n-methylpyrrolidone, benzyl alcohol, benzyl ether, methoxy triglycol, diethyl glycol, and mixtures thereof.

Preferred inks also contain 3-20% by weight, preferably 1
It comprises from 0 to 17% by weight, more preferably 15% by weight of one or more vehicle soluble dyes.

Preferred dyes include quinoline yellow, nitrosine base, acetosol brown, orasol black, and oil yellow. A mixture of 1 part Acetosol Brown and 2 parts Orasol Black is a suitable 'black'.
Currently preferred for obtaining inks.

The inks of this invention further comprise an antioxidant in an amount sufficient to substantially reduce the rate of corrosion by the ink on the metal parts of the ink jet system that come into contact with the ink. As used herein, the term "substantially reduces" the rate of corrosion by one percent of the rate of corrosion that would occur with the same ink without the addition of an antioxidant.
Defined as a decrease of 0% or more. According to this invention,
The antioxidant accounts for 0.1-5% by weight of the ink, preferably 1-4%. 37.5% by weight diethyl glycol, 37.5% by weight methoxytriglycol, 1
In an ink consisting of 0% oleic acid, 5% Acetosol Brown, and 10% Olasol Black RL,
The results of using butylated hydroquinone, a preferred antioxidant, are shown in the following table. This test is 3 inches x 174
using inch test coupons and at 100°C.
This was done by measuring the amount of weight loss of the coupon over a period of ~6 days.

The additive concentration is
Weight loss (%) (10-3/J/day; at 100℃) 0
2.61 1 0.83 3 0.18 5 0.05 As can be seen from the above table, improvement in corrosion resistance and reduction in corrosion rate are shown to be proportional to the concentration of addition.

The effect of the ink of this invention on the corrosion rate depends, of course, to a large extent on the susceptibility of a given metallic material to attack by the ink. Many stainless steels are
It shows little or no corrosion even at moderately elevated temperatures. On the other hand, the corrosion of brass is many times that of nickel. Furthermore, the relative corrosion rate of the nickel part is
There are various types of nickel, including whether the nickel is electroformed (which exhibits a higher corrosion rate) or crude (which exhibits the same or somewhat lower corrosion rate depending on the type of ink used). It will depend on the factors.

As can be seen from the foregoing description, the present invention provides novel inkjet inks and systems that substantially reduce the rate of corrosion attack of the ink on corrosion-sensitive components.

Margin below

Claims (1)

Claims: 1. A fatty acid vehicle, a colorant, and an antioxidant in an amount sufficient to substantially reduce the rate of corrosion.
Impulse jet ink for use in ink jet systems having materials exposed to attack by the ink. 2. The impulse ink jet ink according to claim 1, wherein the antioxidant occupies 0.1 to 5% by weight of the ink. 3. The impulse ink jet ink according to claim 1, wherein the antioxidant is alkylated hydroquinone. 4. The ink according to claim 3, wherein the antioxidant is butylated hydroquinone. 5. The impulse ink jet ink according to claim 1, wherein the fatty acid is a C_8 to C_2_6 fatty acid. 6. Claim 5, wherein the fatty acid is oleic acid
Impulse inkjet ink as described in . 7. Furthermore, aromatic alcohols, aromatic ethers,
and comprising a vehicle additive selected from the group consisting of dimethyl sulfoxides, alkylpyrrolidones, methoxy- and ethoxy-triglycols, polyethylene glycols, aliphatic ketones, and mixtures thereof. is 10 to 90% by weight of the ink.
The ink according to claim 1, which occupies the following. 8. The ink of claim 7, wherein said vehicle additive comprises a mixture of diethylene glycol and methoxy-triglycol. 9. The dye according to claim 1, wherein said dye is selected from the group consisting of quinoline yellow, nigrosine base, acetosol brown, orasol black and oil yellow, and said dye constitutes from 3 to 20% by weight of the ink. ink. 10. Applying ink to an impulse ink jet head having (a) an impulse ink jet ink comprising at least one fatty acid and a dye; and (b) a metal surface in contact with the ink and subject to corrosion thereby. an ink supply means for; and wherein the ink further comprises an antioxidant in an amount sufficient to substantially reduce the rate of corrosion of the metal surface by the ink.