WO2013159135A1

WO2013159135A1 - Dispersion ink

Info

Publication number: WO2013159135A1
Application number: PCT/AT2013/050093
Authority: WO
Inventors: Matteo LAGOMARSINO; Kriemhilt Roppert
Original assignee: Sepiax Ink Technology Gmbh
Priority date: 2012-04-23
Filing date: 2013-04-19
Publication date: 2013-10-31
Also published as: AT512820A1

Abstract

The invention relates to a dispersion ink comprising a combination of a component A and a component B, - wherein component A is an organic compound having a molecular weight between 95 g/mol and 1000 g/mol, and containing at most two acetylene group(s) and at most three terminal functional groups each with at least one heteroatom, and at least two and at most seven terminal functional groups consisting exclusively of carbon and hydrogen, - and component B is formed by polymer particles of an acrylic-based polymer in an aqueous dispersion, wherein the polymer particles have a diameter of at most 200 nm and are free of (meth)acrylonitrile, wherein the molecular weight of substance B is above 200,000 daltons and the glass-transition point is between 50 and 120°C, and wherein the components are in a ratio that is selected from a range with a lower boundary of 1:4 and an upper boundary of 1:8.

Description

dispersion ink

The invention relates to a dispersion ink for an inkjet printer and a simultaneous method for cleaning the Nozzle plate of the printhead of the inkjet printer.

For all inkjet printers, the component that brings the ink to the media is the printhead. With regard to the inkjet printer in the graphic field, the most commonly used technologies are piezo and thermal inkjet. Both of these printhead types have rows of very small openings (also known as "nozzles") from which the ink droplets are ejected.The size of these nozzles varies from manufacturer to manufacturer, but most are smaller in diameter than a human hair; The number of jets can range from several hundreds.One of the common myths about inkjet printers is that the inks are pumped through the nozzles, in fact the opposite is the case since all the printheads require a slightly negative pressure on the inks The process of firing a drop through the nozzle draws more ink from the ink supply into the printhead Many inkjet printers have pumps, but these are either used to transfer ink from the ink tanks to the head Reservoir, or to cleanse the head.

Most of the inks used in the graphic arts industry - except UV-curable inks - dry by evaporation. An ink formulation that dries by evaporation consists mainly of a liquid to keep the ink in a liquid state and also acts as a carrier for the pigments. Upon evaporation of this carrier liquid, the colorants are left in or on the surface of the material. The colorant is either a dye or a pigment. Frequently, a second carrier liquid (or a co-solvent) is used. Primarily, this serves to influence the drying time of the ink. The presence of a second carrier liquid also affects the viscosity of the ink during its manufacture. In addition, most inks contain small amounts of various other additives. These control or help with such aspects as adhesion of the ink to the medium, dot gain, dot formation, printhead corrosion, pH, fade resistance, and color brilliance. However, in simple terms, such an ink can be considered as a combination of carrier liquid (s) and pigment.

A pigment is a very fine powder of solid color particles which is finely distributed (dispersed) throughout the carrier liquid.

The secret of a good pigment ink is that the pigments must remain evenly distributed throughout the carrier liquid for a long time. Pigments show the natural tendency to settle. For a well-made pigment ink, the settling of the pigments should not or only to a small extent.

The golden rule in inkjet printing is: "If an inkjet ink dries on evaporation, the dried ink must redissolve in liquid form through the same ink." While this may sound rather simple, this rule is crucial Most inkjet printing systems capable of producing photo-quality prints have hundreds of nozzles and the openings of these nozzles are always liquid ink, resulting in the problem that the ink dries and The challenge for developers of inkjet printing systems is to develop an ink that will not clog the nozzles during printing but still allow the print image to dry quickly.

Looking closer at a single nozzle clogged with dried ink, one finds that it is easiest to use liquid ink to re-initiate the dried ink. By contrast, a separate cleaning system that bathes the printhead in a solution that causes the ink to dissolve again makes a major contribution to ensuring that the print System gets more complex. It's easier to bet on the "Golden Rule" and rely on the ink to turn itself on.

However, it is not sufficient to have a good balance between cosolvent and carrier liquid in the ink formulation to avoid fouling of the nozzle plate.

A common misconception is that when nozzles of a printhead become clogged (as seen by lines or banding in the print itself), this is caused by contamination or lumps in the ink. In 99% of all cases is for the clogging of a

Printhead dried ink or a bubble in her responsible. Air in the duct behind the nozzle of a printhead is a sure way to keep the ink from burning properly, because the air acts as a kind of shock absorber, and an ink drop that is ejected from the nozzle consists of three main parts: drops, ligament and satellites If the drop formation is not optimal, the ink tends to deposit on the nozzle plate during the jetting process, and once these deposits have reached a certain size, they will inevitably clog the nozzles from the outside.

In the so-called variable drop printing mode, the risk of producing deposits on the nozzle plate is even greater: various printhead control pulses produce different droplet sizes almost simultaneously, greatly increasing the risk of producing unwanted ligament / satellite collisions.

In general, there are two ways to clean soiled printheads during the production process:

- WIPER Cleaning: During printhead cleaning, the wiper moves mechanically back and forth several times under the printhead. With her rubber lip she pushes the excess ink aside during the cleaning process. Depending on the frequency of use and the type of ink used, the wiper may stick to the ink due to contamination and deposits. Then the real function

- cleaning the printhead - will affect or cause the wiper to smudge the printhead.

- PURGE cleaning: During print head cleaning, a significant amount of ink is "pressed" by the print head; According to the principle "ink dissolves ink", this is certainly a proven method to get the nozzles free again. Both methods inevitably lead to the following problems:

- Reduction of productivity due to downtime in printhead maintenance.

- Reliability in printing is not given, since it is not certain that the printer produces the print job without Nozzle- failures.

- Waste of ink during maintenance or production process.

From the prior art approaches are already known in which primarily by the Tinteneigen- shafts, the contamination of the Nozzle plate is known.

Thus, DE 695 26 957 T2 describes a stable ink-jet ink composition comprising a diluent containing not more than 5% by weight of water, a pigment and a dispersant for stabilizing the dispersion of the pigment in the diluent, the diluent being a non-polar Component as a main component, for example, dearomatized petroleum distillates, paraffins, and a polar organic liquid or a mixture of polar organic liquids as a minor component, for example, alcohols, glycols, alkoxylated alkylphenols, wherein the minor component in an amount of at least 5 wt .-% of the diluent present , wherein the diluent has a polar solubility keitsparameter greater than zero but not greater than 7 MPa ^Vl and the composition having a dewetting velocity of at least 100 μι εΰ ^ ^'1 on a surface having a surface energy of 10 + ImN.m ^"1 It solves the task a stable dispersion ink based on a non-polar solvent available which provides a well-defined print of acceptable optical density when printed from an ink jet printhead and increases the amount of uninterrupted print run without having to interrupt printing to clean or replace the printhead.

WO 2010/100438 A1 is concerned with an ink based on ethyl lactate and a dialkyl ether of ethylene or propylene glycol in order to remedy problems which occur especially with the Nozzle plate of MEMS printheads.

DE 696 18 658 T2 describes a dispersion ink of an ink jet printer in which the diluent is non-aqueous or contains less than 2% by weight of water, the dispersion ink comprising a dispersant having either basic or acidic groups and an amount of neutralizer therefor Contains groups, the amount being insufficient to cause sedimentation and / or an increase in viscosity in the ink within 28 days during its storage at 25 ° C.

Even in emphatically water-based formulations, the approach of formulating an ink in such a way that the Nozzles remain free for as long as possible is known in principle. The publications mentioned below use different substances and mechanisms.

An example of this is EP 1 457 534 A1. It is explained why the previous solutions for the prevention of Nozzle clogging are unsatisfactory, given an overview of newer solutions in the literature and presented a group of substances, which should allow in combination with a standard ink to print longer without cleaning or the open time to improve massively.

EP 0 834 538 A1 describes an aqueous ink system which likewise should not cause nozzle clogging. The cause is mainly seen in impurities, mainly by metal ions. These are complexed with chelating agendas. EP 0 909 798 A1 relates to a system comprising inter alia a water-soluble, cationic polymer and a so-called "googling preventor." The present invention is based on the object of providing a dispersion ink , with which an improvement in terms of contamination of Nozzle plate of an inkjet printer can be achieved.

This object is achieved with the dispersion ink mentioned in the introduction, which comprises a combination of a component A and a component B,

- wherein the component A is at least one organic compound having a molecular weight between 95 g / mol and 1000 g / mol, and in the at least one and a maximum of two acetylene group (s) and at least one and a maximum of 3 terminal functional groups with each containing at least one heteroatom and at least two and not more than seven terminal functional groups consisting exclusively of carbon and hydrogen,

- And the component B is formed by polymer particles of at least one acrylic polymer in aqueous dispersion and / or an acrylic-based polymer in aqueous dispersion, wherein the polymer particles have a maximum diameter of 200nm and are free of (meth) acrylonitrile, wherein the molecular weight of the substance B is greater than 200,000 daltons and the glass transition point is between 50 ° C and 120 ° C, and wherein component A is contained in a ratio to component B selected from a lower limit region of 1: 4 and an upper limit of 1 The object of the invention is achieved independently by the use of this ink for cleaning a nozzle plate of an ink jet printhead.

Surprisingly, the two components have a synergistic effect. The component B is present as an aqueous dispersion not as an elongated molecule but as a loose ball, ie at least approximately spherical, before. In contrast, the hydrophilic parts of the polymer tend to be on the outside, whereas the hydrophobic parts are more often within the "polymer sphere." This "polymer sphere" is known to be formed by oligomers (very short polyols). Peters et al, Progress in Organic Coatings 38 (2000), 137-150) .The interactions that are important for the attachment are based on the interaction of positive and negative charges Hydrophobic and hydrophilic interactions also play a role, increasing the number of hydrophilic groups as a whole against the external, aqueous medium, and further stabilizing the formed "polymer sphere" with a more hydrophilic surface than in a disordered arrangement.

By stabilizing these individual "polymer spheres" in solution in this way, of course, stabilization of the "polymer sphere" after ink-jet printing naturally also results and, as a result, it takes longer for a uniform film to form. This means that the drying time is longer. Also, the feel, gloss, etc. may be adversely affected, especially on non-absorbent materials such as polyethylene, polypropylene or polyvinyl chloride.

Component A interacts with these oligomers on the polymers of component B. They do not negatively influence the stability in solution (in the finished ink), but ensure that the individual "polymer spheres" fuse more rapidly to form a film after printing It has been found that with this combination of component A and component B on the printhead, the nozzles jetting exhibits unusual behavior, resulting in less soiling of the nozzle plate and, therefore, seldom need separate cleaning The unusual behavior of the Nozzles can be characterized by the fact that after the "shooting" of the inkjet, ie the ejection of ink, the meniscus of the ink quickly retreats into the Nozzles and any soiling by the ink on the surface of the Nozzle environment into the printhead so that the printhead stays clean. After every "shooting" of the Nozzles, where some of the ink can reach the surface due to previously mentioned processes ("Nozzle plate"), the ink will be retracted after 10μ8 at the latest. This prevents the ink from drying on the Nozzle plate during this time. Since this behavior occurs regardless of when the Nozzle will shoot the next time, the Nozzle plate remains clean and even if the Nozzle plate Do not shoot for a long time. Even if the Nozzles are above a heater, problems with soiling on the Nozzle plate are at least almost completely avoided or prevented. It should be noted at this point that the term component A or B not only individual organic compounds are understood, but also mixtures of several organic compounds, as long as each of these compounds of the mixtures meet the conditions for component A or component B. The term "dispersion ink" is understood to mean an ink for ink-jet printing in which the colorant is dispersed in the ink, so that dissolved colorants are not covered thereby.

According to one embodiment variant, it is provided that the one or more hetero atoms (e) of component A are formed by nitrogen or oxygen. On the one hand, the interaction between component A and the oligomers of component B is thereby improved on account of the electronegativity of these elements, but on the other hand this interaction is not so strong in comparison to other heteroatoms that the dispersion itself becomes unstable.

The terminal functional groups consisting exclusively of carbon and hydrogen are preferably selected from a group comprising alkyl groups (unbranched, branched and cyclic), aryl groups (with and without substituents), and radicals having one or more multiple bonds. It is thus achieved that the steric influences of this group (s) achieve a balance between the electronegative subregions and rather hydrophobic subregions in 3d space, which is advantageous for the interaction with the oligomers.

The component A may be contained in a proportion selected from a range having a lower limit of 0.15 wt% and an upper limit of 3.5 wt%. At a content of less than 0.15% by weight, it has been observed that the desired "cleaning effect" is only slightly formed, whereas when the proportion is greater than 3.5% by weight, the static surface tension of the ink too low, so that the drop can not separate well enough from the ligament. This leads to a strong impairment of the Jettability.

According to another embodiment variant it can be provided that the component B is contained in a proportion which is selected from a range with a lower limit of 1.0% by weight and an upper limit of 15% by weight. Below 1% by weight, many satellites form during the drop formation; above 15% by weight, the risk of film formation by the polymers on the meniscus leading to clogging is too great. In the preferred embodiment, components A and B are added in a ratio of 1: 6 to each other. This achieves the optimum of coupled self-cleaning and stable drop formation.

For a better understanding of the invention, this will be explained in more detail with reference to the following examples.

With the exception of the mixture of the two components A and B, the dispersion ink according to the invention is composed according to the prior art. Such dispersion inks usually contain one or more substances selected from a group comprising or consisting of at least one organic solvent or water as solvent, at least one pigment in the form of a pigment, substances for controlling the pH and surface tension.

Organic solvents can e.g. be:

Polyethylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, 2-pyrrolidone, 2,2-thiodiethanol, 1, (2-hydroxyethyl) -2-pyrrolidone, trimethylolpropane, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,2-hexanediol, hexylcarbitol, diethylene glycol butyl ether, diethylene glycol zyl ether, n-propyl alcohol, ethoxylated acetylenediols, dimethysulfite, diethylene glycol zyl ether, n-propyl alcohol, ethoxylated

Acetylenediol, dimethysulfoxide, aliphatic C 1 -C ₄ -alcohols, linear or branched, pentanediol, aliphatic ketones such as acetone, methyl ethyl ketone, diacetone alcohol, polyols such as ethyleneglycol, diethylene glycol, triethylene glycol, polyglycols having a molecular weight of 200-2000 g / mol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, glycerol, thiodiglycol, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethyl-imidazolidinone, dimethylacetamide, dimethylformamide, or mixtures thereof. Pigments can be, for example:

Black:

Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven, Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300 and Monarch, No. 2300, No. 900, MCF88, no. 33, No. 40, no. 45, No. 52, MA7, MA8, MA100, no. 2200B Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S 150, Color Black S 160, Color Black S 170, Printex 35, Printex 45, Printex U, Printex V, Printex 140U , Special Black 6, Special Black 5, Special Black 4A, Special Black 4, Black 7.

cyan:

C.I. Pigment Blue 15: 3, C.I. Pigment Blue 15: 4, C.I. Pigment Blue 16, C.I. Pigment Blue 22, C.I. Pigment Blue 60, C.I. Pigment Blue 1, C.I. Pigment Blue 2, C.I. Pigment Blue 3, C.I. Vat Blue 4, C.I. Vat Blue 60th

Magenta: C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red 168, C.I. Pigment Red 184, C.I. Pigment Red 202, C.I. Pigment Red 5, C.I. Pigment Red 7, C.I. Pigment Red 12, C.I. Pigment Red 48 (Ca), C.I. Pigment Red 48 (Mn), C.I. Pigment Red 57 (Ca), C.I. Pigment Red 57: 1, C.I. Pigment Red 112. Yellow:

CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 129, CI Pigment Yellow 1, CI Pigment Yellow 1, CI Pigment Yellow 1, CI Pigment Yellow 1, CI Pigment Yellow 1, CI Pigment Yellow 2, CI Pigment Yellow CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 16, CI Pigment Yellow 17, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 75, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98, CI Pigment Yellow 180.

White:

Tiianium dioxide, zinc white. Lkhopon, lead white, zinc sulphate, lead sulphate, zirconium oxides, antimony white, B iidioxid.

Substances for controlling or adjusting the pH are, for example:

Trimethylamine, monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, N, N-diethylethanolamine, Ν, Ν-dibutylethanolamine, N, N-di-n-butylethanolamine, NaOH, KOH, hydrochloric acid, acetic acid, citric acid.

Substances for controlling or adjusting the surface tension are, for example:

BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK- 333, BYK-337, BYK-344, BYK-370, BYK-375, BYK-377, TEGO-RAD 2100, TEGO-RAD2200N, TEGO-RAD2250, TEGO-

RAD2300, TEGO-RAD2500, TEGO-RAD2600, TEGO-RAD2700, Surfynol 420, Surfynol 440, Surfynol 465, Surfynol 485, Surfynol 104, Surfynol TG, Surfynol SE, Glanol 100, Glanol 115, Glanol 400, Glanol 410, Glanol 435, Glanol 440, Glanol 450, B-1484, Polyflow ATF-2, KL-600, UCR-L72.

It should be noted that the above-mentioned conventional ingredients of dispersion inks have only exemplary character and are not to be seen as limiting the invention.

According to the invention, it is provided that the dispersion ink contains a mixture of a component A and a component B. Component A is characterized by the chemical structure, which is reflected in the following features: the molecular weight is between 95 g / mol and 1000 g / mol;

It has been shown that both a certain rigidity and a certain flexibility in the molecule must be present; But this is only possible from a certain minimum size. The upper limit arises from the fact that in a larger molecule, the interaction with the oligomers is no longer reproducible. at least one and at most two acetylene groups are present in the compound;

These give the system a rigid component; corresponding double bonds surprisingly do not fulfill this purpose. The reason is believed to be that alkenes have a strong nucleophilic character while alkynes are only weakly nucleophilic. As a result, the interaction with the oligomers is different. at least one and at most three terminal functional groups are present, each containing at least one heteroatom.

This is important because some electronegativity improves the desired interaction with the oligomers. there are at least two and at most seven terminal functional groups containing only carbon and hydrogen.

In principle, this is the balance between electronegative groups and the classical properties of aliphatic hydrocarbons. However, additional steric effects due to voluminous groups can not be ruled out. The heteroatom (s) of the terminal functional group is preferably nitrogen or oxygen. In this case, the same heteroatom, ie, for example, only nitrogen or only oxygen, or even different heteroatoms may be present in these terminal functional groups, so that, for example, in a molecule of component A both oxygen and nitrogen are present as heteroatoms in the terminal functional groups.

The heteroatom-containing functional terminal group may be selected from a group comprising or consisting of carboxy groups, amino groups, hydroxy groups, but also on silicon, sulfur and halogen-based end groups.

The terminal functional groups consisting exclusively of carbon and hydrogen may be selected from the group mentioned above. It is possible that only the same of these terminal functional groups or different are present within a molecule.

For example, component A may be formed by a compound selected from a group comprising or consisting of:

Dimethyl acetylenedicarboxylate, 1-dimethylamino-2-propyne, 1-phenyl-2-propyn-1-ol, 3- (3-methoxyphenyl) -2-propyn-1-ol, 1,1-diphenyl-2-propyn-1 -ol, 1,1,3-triphenyl-2-propyn-1-ol,

1- (1-propynyl) cyclohexanol, 3-butyn-2-ol, 3-chloro-3-methyl-1-butyne, 2-methyl-3-butyne

2-ol, 2-methyl-4-phenyl-3-butyn-2-ol, 4- (3-aminophenyl) -2-methyl-3-butyn-2-ol, 4-diethylamino-2-butyn-1-ol ol, 1-acetoxy-4-diethylamino-2-butyne, 4-pentyn-2-ol, 1-chloro-2-methyl-3-pentyn-2-ol, 4-pentyn-1-yl acetate, 3-methyl - l -pentyn-3-ol, 3-methyl-1-penten-4-yn-3-ol, 4-methyl-1-pentyn-3-ol, 5-dimethylamino-2-methyl-3-pentyn-2 -ol, 3,5-dimethyl-1-hexyn-3-ol, 3-hexyn-2-ol, 2-methyl-3-hexyn-2-ol, 2,5-dimethyl-3-hexyne-2,5 -diol, 1-octynyl

3-ol, 3,6-dimethyl-4-octyne-3,6-diol, 2-methyl-5-octyn-4-ol, 2,4,7,9-tetramethyl-5-decyne-4,7- diol, 7-tetradecyne-6,9-diol, 3-trimethylsiloxy-1-propylene, 3-trimethylsilyl-2-propyn-1-ol, 4-trimethylsilyl-3-butyn-1-ol, 4- (trimethylsilyl) - 3-butyn-2-ol, 4-trimethylsilyl-3-butyn-2-one, 1-trimethylsilyl-3,3-dimethyl-1-butyne, 1,4-bis (trimethylsilyl) -1,3-butadiyne, 5 - Trimethylsilyl-4-pentyn-1-ol, 1-trimethylsilyl-1-hexyne; 2,4,7,9-tetramethyl-5-decylene-4,7-diol ethoxylate,

Ethynyl (trimethyl) silane; Ν, Ν, Ν ', Ν'-tetramethyl-2-butyne-1, 4-diamine; 3, 5-octadiyne-2,7-diol; 1-ethynylcyclohexanamine; l, l-dicyclohexyl-2-propyn-l-ol; 5,5-dimethyl-8-

(Trimethylsilyl) -7-octyne-2,4-dione; 2,2-dichlorovinyl methyl 2-propynyl phosphate; 1-methyl-1- (trichloromethyl) -3-butynyl carbamate; l- (ethynylsulfonyl) -4-methylbenzene; (3aR, 6aR) -3,3-dimethyl-3a- [4- (trimethylsilyl) -3-butynyl] hexahydrol (2H) -pentalenones; 1,1,6,6-tetraphenyl-2,4-hexadiyne-1,6-diol; (LE) -2-methyl-l-phenyl-l-penten-4-yn-3-ol; 6-chloro-N (2) -cyclopropyl-N (4) - (1-methyl-2-butynyl) -l, 3,5-triazine-2,4-diamine; 6-chloro-N (2) - cyclopropyl-N (4) - (1-ethyl-1-methyl-2-propynyl) -1,3,5-triazine-2,4-diamine; 2- {[(1-methyl-3-butynyl) oxy] carbonyl} benzoic acid; 6-chloro-N (2) -ethyl-N (4) - (1-methyl-2-butynyl) -1,3,5-triazine-2,4-diamine; D (-) - norgestrel; N- (1-ethyl-1-methyl-2-propynyl) -N '- (2-fluorophenyl) urea; 3 - [1,1-dimethyl-4- (trimethylsilyl) -3-butynyl] -2-cyclopenten-1-one; 1-ethyl-1-methyl-2-propynyl 4-nitrobenzoate; 2- {[(1,1-dimethyl-2-propynyl) amino] carbonyl} benzoic acid; N- (3, 4-dichlorophenyl) -N '- (1,1-dimethyl-2-propynyl) urea; (1R, 6R) - 1, 6-bis (2-chlorophenyl) -1,6-diphenyl-2,4-hexadiyne-1, 6-diol; AA-861; 1, 1, 4,4-tetraphenyl-2-butyne-1, 4-diol; (3-furylethynyl) (trimethyl) silane; 1-methyl-5 - [(trimethylsilyl) ethynyl] -1H-imidazole; (17beta) -3-methoxy-17- (2-propynyl) estra-l, 3,5 (19) -trien-17-ol; 2-propynyl-4- (aminosulfonyl) -1,3-dimethyl-1H-pyrazole-5-carboxylates; 4- {[(3-chloroanilino) carbonyl] oxy} -N, N, N-trimethyl-2-butyn-1-amino chloride; 5- (trifluoromethyl) -4 - ((trimethylsilyl) ethynyl) -1 H -pyrrolo [2,3-b] pyridines; Mifepristone; 4- [(17beta) -17_hydroxy-3-methoxyestra-1,3,5 (10) -trien-17-yl] -2-butynoic acid; WIN 51708 hydrate; (17beta) -1- [3- (dimethylamino) phenyl] -17-hydroxy-17- (1-propynyl) estra-4,9-diene-3-one; WIN 62.577.

All compounds are commercially available, in Europe eg Sigma-Aldrich, VWR or TCI Europe. Preferably, compounds are used which have at least three methyl groups and only one type of a heteroatom group, but these in any number (within the definitions already given). In the event that the compound according to the conditions for the component A is not sufficiently soluble in water to be introduced directly into an aqueous ink system, it is possible to add small to medium amounts of various known auxiliaries, for example 1,2-propanediol, or known dispersion techniques for example, stirrers or mills. The term "small to medium amount" is understood to mean a proportion of not more than 100% by weight, based on the total amount of component A.

It is also possible within the scope of the invention that component A is formed from a plurality of different compounds, for example two, three, four, etc., all compounds of this mixture satisfying the specified conditions for component A.

Component B is formed by one or more polymer (s) in aqueous dispersion. These polymers are characterized by the following features:

- The individual polymer particles have a maximum diameter of 200nm, in particular a maximum of 150 nm. With larger particles, the cleaning effect is achieved only unsatisfactory.

- The polymer particles are made of acrylic polymers and / or copolymers with it. These may be "pure" polyacrylates or else copolymers (random, alternating, and block copolymers as well as graft and gradient polymers), examples of which are ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, Methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-

Hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate. 1,4-butanediol dimethacrylate, urethane dimethacrylate, 2,2-bis (4- (2-methacryloxyethoxy) phenyl) propane, 2,2-bis (4- (methacryloxy) phenyl) propane, 2,2-bis ( 4- (2-hydroxy-3-methacryloxypropoxy) phenyl) propane, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, oligotriacrylate 480, (2,2-bis (4- (2-hydroxy-3-acryloxypropoxy) phenyl) propane, urethane diacrylate (aliphatic), urethane diacrylate (aromatic), triethylene glycol diacrylate, Ν, Ν-methylenebisacrylamide, tetrahydrofurfurylmethac- ethylate, ethyl cyanoacrylate; also ethylene-vinyl acetate-acrylate, vinyl acetate-vinyl chloride-ethylene acrylate, acrylic ester-vinyl acetate, substituted and unsubstituted styrene / acrylate, carboxylated styrene / acrylate, vinyl / acrylate and vinyltoluene / acrylate. - None of the polymer particles used contains methacrylonitrile or acrylonitrile

- The molecular weight is over 200,000 daltons;

The necessary viscosity of the ink is achieved by the polymers. If the molecular weight is too low, a great deal of polymer has to be used to achieve the required values. However, this leads to problems with the drying of the ink.

- The glass point is between 50 ° C and 120 ° C, in particular between 60 ° C and 120 ° C. This influences film formation under realistic drying conditions.

Such polymers are commercially available, for example under the name: VONCOAT;

BONCOAT SAE1014; SALBINOL SK-200; SURCOL ™ 836, 860, 441; CARBOSET ™ 525, 527;

JONCRYL ™ 52, 62, 67, 77, 95, 537_E, 538, 586, 611, 661, 668, 671, 680, 682, 683, 690, 693, 2038, 2178, 8067, 8078, 8082, 8083, HPD 296 ;

MICROGEL; NOBEL ™ DLX 3-5 or NOBEL ™ DHX 5-8;

PARALOID B-66 and B-72; NEOCRYL ™ B-725, B-731, B-735, B-810, B-811, B-813, B-814, B-817, B-842, B-890; UCAR VYHH, VMCH, YMCA, VAGF; VINNOL E15 / 45, H14 / 36, E15 / 45M.

These polymers are available from the respective manufacturers or trademark owners.

In the relevant literature, methods are also known which set out in detail how such a dispersion can be prepared. , An example provided by Peters et al, Progress in organic coatings 38 (2000), 137-150: the monomers are introduced with stirring at 90 ° C in a reaction flask. This is also equipped with a return flow system. After complete reaction, the resulting particles are cooled to room temperature and the pH is adjusted. It is then filtered to remove any sediment from the reaction. From different approaches arise oligomers or polymers. These can then be fused to the mentioned polymer-oligomer combinations.

Only one type of polymer particle can be contained in the dispersion ink. In particular, in this case, a polymer is used from the group consisting of or consisting of acrylic-based polymers. This is justified in particular by the fact that with these polymers the ink in the aqueous system good properties with regard to reversibility, rheology, rate of drying, film formation and film strength can be achieved.

On the other hand, there is also the possibility that the dispersion ink contains more than one type of polymer particles, in particular a mixture of up to three different types of polymer particles. Possible combinations are characterized above all by polymers having different glass transition points within the abovementioned limits; This results in an improved MFT (minimum film forming temperature) and improved strength of the resulting film.

In particular, the component A is contained in the dispersion ink in an amount selected from a range having a lower limit of 0.15% by weight and an upper limit of 3.5% by weight.

In particular, component B is contained in an amount selected from a range having a lower limit of 1.0 wt% and an upper limit of 15 wt%.

In the preferred embodiment, component A is contained in a proportion to component B in the dispersion ink selected from a lower limit region of 1: 4 and an upper limit of 1: 8, especially 1: 6. These preferred ratios have been found experimentally and are explained in the embodiments. Too large amounts of component A, the oligomers are strongly attacked and impaired in their function (stabilization of the polymer system). Again, if the levels are too low, the oligomers will not be able to be appreciably interacting with the polymer.

The preparation of the dispersion ink can be carried out as follows: with stirring, the individual components (s.u.) are brought together in succession. Finally, it is stirred for 10 minutes. Depending on the specification of the ink head manufacturer, the inks are then filtered, e.g. with Ιμιη polypropylene from Pall. The ink is now ready to use.

To evaluate the mode of action of the dispersion ink, the following example formulations were tested.

In general, the solvents may be from a group comprising or consisting of dipropylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, dimethyl sulfite, polyethylene glycol, diethylene glycol, 2,2-thiodiethanol, 1, (2, -hydroxyethyl) -2-pyrrolidone, Trime - thyolpropane, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,2-hexanediol, hexylcarbitol, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone, butyl ether, diethylene glycol benzyl ether, n-propyl alcohol, ethoxylated acetylenediols, dimethysulfoxide or mixtures thereof.

All of the following dispersion inks were prepared according to the method described above. In this case, component A and component B in each of the examples according to the invention were each added as a 50% solution or dispersion in water.

Example:

To demonstrate the cleaning effect, a nozzle plate of an ink jet printer was artificially stained. After a short shot of the Nozzles with this example recipe of the dispersion ink a clean Nozzleplate was seen.

During actual production, ie without artificial soiling, it has been observed that no large accumulations of ink residues are visible on the nozzle plate by this dispersion ink or method. In the course of the evaluation of the effect of the dispersion ink, the following further example formulations were prepared. All formulations had the following ingredients:

deionized

68.5 parts of water 4 parts Pigment Pigment Yellow 155

11 parts of solvent 1 diethylene glycol

5.8 parts Solvent 2 1,2-propanediol

4.5 parts of solvent 3, 1,2-hexanediol

0.4 parts of pH adjuster triethanolamine

To this "master recipe", Components A (0.8 parts) and B (5 parts) were each added as a 50% solution or dispersion as follows:

Example Component A Component B Evaluation

1 2-methyl-5-octyn-4-EOCRYL ™ B-2

ol 810

2 4-methyl-1-pentyn-NEOCRYL ™ B-3

3-ol 810

3 4-Methyl-1-pentyn-SURCOL ™ 836 1

3-ol

4 7-Tetradecyne-6,9-SURCOL ™ 836 4

diol

5 7-Tetradecyne-6,9 CARBOSET ™ 525 6

diol

6 7-Tetradecyne-6,9 CARBOSET ™ 527 8

diol

7 1, 1, 4,4-tetraphenyl JONCRYL ™ 611 3

2-butyne-l, 4-diol

8 1, 1, 4,4-tetraphenyl JONCRYL ™ 8067 3

2-butyne-l, 4-diol

9 N- (3,4- CARBOSET ™ 527 10

dichlorophenyl) -N '-

(1,1-dimethyl-2-propynyl)

10 N- (3.4- SURCOL ™ 836 8

dichlorophenyl) -N '- (1,1-dimethyl-2-propynyl)

The evaluation was carried out visually and rated with a number between 1 and 10, whereby the number 10 means very good cleaning properties, the numeral 1, however, means that a cleaning practically does not take place.

As part of the evaluation of the dispersion ink, the following comparative examples of dispersion inks were also prepared and tested according to the above-described production method.

In all the comparative examples, it was found that in normal operation, there is a consecutive soiling on the Nozzle plate, which is clearly visible after a few small deposits.

Comparative Example 1

In this comparative example, the ratio of components A and B does not cause proper jetting behavior

Comparative Example 2: 59 parts of deionized water

20 parts Pigment Pigment Red 122

10 parts of solvent 1 diethylene glycol

5 parts of solvent 2 1,2-propanediol

5 parts of solvent 3 1,2-hexanediol

0 parts substance B

0.5 parts of pH adjuster triethanolamine

N- (3,4-dichlorophenyl) -N '- (1,1-dimethyl-2-propynyl)

0.5 part of substance A (50% in water)

Without component B, the ink residue on the Nozzle plate will not retract, allowing you to see how each Nozzles crawls in quick succession.

Comparative Example 3

This comparative ink has no share of component A. Although the ink forms a decent ligament, undirected satellite drops irrevocably pollute the Nozzle plate and can no longer be withdrawn.

Comparative Example 4 54.5 parts of deionized water

20 parts Pigment Pigment Red 122

10 parts of solvent 1 diethylene glycol

5 parts of solvent 2 tetraethylene glycol

5 parts of solvent 3 1,2-propanediol

3 parts of substance B CARBOSET ™ 527

0.5 parts of pH adjuster triethanolamine

N- (3,4-dichlorophenyl) -N '- (1,1-dimethyl-2-)

4 parts of substance A propynyl) (50% in water)

Component A overrides the system so that the drops from the nozzle plate are no longer properly discharged and the ink can not form a stable jet. This comparative example shows the effect of the preferred ratio of the proportions of components A and B.

The exemplary embodiments show possible embodiments of the dispersion ink, wherein it should be noted at this point that the invention is not limited to the specifically described embodiments of the same, but rather also various combinations of the individual embodiments are possible with each other and this variation possibility due to the teaching of technical action by objective invention in the skill of those skilled in this technical field.

Claims

Patent claims

1. Dispersion ink of an ink jet printer comprising a combination of a component A and a component B,

wherein component A is an organic compound having a molecular weight between 95 g / mol and 1000 g / mol, and in the at least one and at most two acetylene group (s) and at least one and at most three terminal functional groups each having at least one Heteroatom and at least two and not more than seven terminal functional groups, consisting exclusively of carbon and hydrogen, are included,

- And the component B is formed by polymer particles of at least one acrylic polymer in aqueous dispersion and / or an acrylic-based polymer in aqueous dispersion, wherein the polymer particles have a maximum diameter of 200nm and are free of (meth) acrylonitrile, wherein the molecular weight of the substance B over 200,000 daltons and the glass point between 50 ° C and 120 ° C,

and wherein component A is contained in a ratio to component B selected from a lower limit region of 1: 4 and an upper limit of 1: 8.

2. dispersion ink according to claim 1, characterized in that the teroatom or heteroatom (s) of component A are formed by nitrogen or oxygen.

3. dispersion ink according to claim 1 or 2, characterized in that the consisting exclusively of carbon and hydrogen terminal functional groups of the component A are selected from a group comprising alkyl groups, aryl groups, and radicals having one or more multiple bonds.

4. dispersion ink according to any one of claims 1 to 3, characterized in that the component A is contained in a proportion which is selected from a range having a lower limit of 0.15 wt .-% and an upper limit of 3.5 wt .-%.

5. dispersion ink according to one of claims 1 to 4, characterized in that the component B is contained in a proportion which is selected from a range with a lower limit of 1.0 wt .-% and an upper limit of 15 wt. %.

6. dispersion ink according to any one of claims 1 to 5, characterized in that the component A is contained in a ratio of component B of 1: 6.

7. A method for cleaning a Nozzle plate of an ink jet print head under

Use of a dispersion ink comprising a combination of a component A and a component B,

wherein component A is an organic compound having a molecular weight between 95 g / mol and 1000 g / mol, and in the at least one and at most two acetylene group (s) and at least one and at most 3 terminal functional groups each having at least one Heteroatom and at least two and not more than seven terminal functional groups, consisting exclusively of carbon and hydrogen, are included,

and wherein and wherein component A is included in a ratio to component B selected from a lower limit region of 1: 4 and an upper limit of 1: 8.