MXPA00008290A - Coloured polyurethanes - Google Patents

Abstract

The invention relates to polyurethanes, inks comprising polyurethanes and their use in ink jet printing where the polyurethane comprises a coloured water-dissipatable polyurethane obtainable by chain-terminating a polyurethane prepolymer with a colorant.

Description

COLOR POLYURETHANES Field of the Invention This invention relates to polyurethanes, to inks comprising polyurethanes and to their use in inkjet printers.

Background of the Invention Ink jet printing methods involve a non-impact printing technique to print an image on a substrate by firing ink droplets through a thin nozzle on a substrate without the fine nozzle having contact with the substrate. . ' These are very demanding performance requirements for the dyes and inks used in inkjet printing. For example, these desirably provide shapes, non-granular images having good water resistance, good light resistance and optical density. Inks are often required to dry quickly when applied to a substrate for REF: 122176 prevent them from being erased, but they do not form a layer that can block the drip of the fine nozzle. The inks may also be stable for storage for a while without decomposing or forming a precipitate which may also block the fine nozzle. Thermal inkjet and piezoelectric inkjet printers are widely used, so it is a necessity for inks, suitable for use on both types of printers, to have a highly strong color and to give images that have solids to light and solids. to water when printed on a "typical" substrate, especially plain paper. s EP 0769 5-09 describes a high-molecular-weight, extended-chain polyurethane formed from a colored polyurethane-terminated polyurethane prepolymer, however this composition is not ideal for use in ink jet printers with thermal heads The use of heat can result in blockage of the nozzles and other operating problems.

Description of the invention It has now been found that color polyurethanes according to the present invention can be used to make inks that are suitable for both thermal and piezo inkjet printers.

In accordance with a first aspect of the present invention, there is provided a water-dissipable, colored polyurethane, obtained from processes comprising the steps of: i) reacting a mixture comprising the components (a) and (b) wherein the component (a) is at least one organic polyisocyanate and the component (b) is at least one compound that reacts in isocyanate which provide dispersible groups in water; and ii) chain the product of step i) with the component (c) wherein the component (c) comprises a dye having a functional group capable of reacting with the components (a) or (b).

Preferably the color-dissipable polyurethane in water has an average molecular weight (mp) of less than 50,000, since this molecular weight leads to improvements in the performance of the inks - which contain the polyurethane, especially for use in jet printers. thermal ink. The Pm of the polyurethane is preferably less than 40,000 more preferably less than 30,000. The pm of the polyurethane is preferably greater than 1000. The pm can be measured by gel permeation chromatography.

The gel permeation chromatography method used to determine the pm preferably comprises the polyurethane to a chromatography column packed with a "crosslinked polystyrene / divinyl benzene, eluting the column with tetrahydrofuran at a temperature of 40 ° C and testing the pm of the polyurethane compared to a number of polystyrene standards of a known pm. Appropriate chromatography columns packed with a polystyrene / divinyl benzene cross link are commercially available from Polymer Laboratories.

As an alternative to the cpg method to determine ei pm, one can use other methods, for example multiangular light scattering.

Component (a) can be any organic polyisocyanate known in the art, preferably having two isocyanate groups, and includes aliphatic, cycloaliphatic, aromatic or araliphatic isocyanate. Examples of suitable organic polyisocyanates include 1,6-hexamethylene ethylene diisocyanate diisocyanate, isbforone diisocyanate, tetramethylxylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2-6-diisocyanate. toluene, 4,4'-diphenyl-methane diisocyanate and its hydrogenated derivatives, 2,4 '-diphenylmethane diisocyanate, and its hydrogenated derivatives, and 1,5-naphthylene diisocyanate. The mixtures of the polyisocyanates can be used, in particular isomeric mixtures of the toluene diisocyanates or isomeric mixtures of the diphenylmethane diisocyanates (or their hydrogenated derivatives), and also organic polyisocyanates which can be modified by the introduction of urethane, allophanate, urea residues, biuret, carbodiimide, uretonimine or isocyanurate.

Preferred organic polyisocyanates include cycloaliphatic polyisocyanates, especially isophorone diisocyanate, and aliphatic isocyanates, especially 1, β-hexamethylene diisocyanate or di-hydroxylated, -diphenyl methyl diisocyanate. A small amount of the triisocyanates may be included as part of component (a) but their amount preferably will not exceed 5% by weight relative to the total weight of component (a). In a preferred embodiment, component (a) consists of a mixture of diisocyanate and from 0 to 5% of triisocyanate per weight relative to the diisocyanate.

Component (b) which provides water dispersible groups, preferably has at least one and preferably has two, groups that react with the isocyanate. The preferred isocyanate-reacting groups are selected from -OH, -NH2, -NH- and -SH. Compounds having three isocyanate-reactive groups can be presented as part of component (b), preferably, at low levels not exceeding 5% by weight relative to the total weight of component (b). These groups which react with the isocyanate are capable of reacting with an isocyanate group (-NCO) in component (a) or component (c). Preferred components (a) and (b) are colorless.

Water-dispersible groups are preferably present in the polyurethane as chain, pendant or terminal groups. Additional water-dispersible groups can be introduced into the polyurethane as a reactive layer having an isocyanate group or reacting in isocyanate and a water dispersible group.

The nature and level of the water dispersible groups in the polyurethane has the influence that a solution, dispersion, emulsion or suspension is formed in the dissipation of the polyurethane.

The water dispersible group contained in the polyurethane can vary within wide limits but is usually selected to sufficiently secure the polyurethane forms of ink jet printing inks in an aqueous and water medium. The polyurethane is preferably soluble in water, however a small amount of the polyurethane may not be soluble in water and exist as dispersed particles when mixed with an aqueous medium or with water.

Preferably the portion of the insoluble polyurethane is less than 50%, preferably less than 40% and more preferably less than 30% by weight relative to the total weight of the polyurethane.

The water dispersible groups can be ionic, nonionic or a mixture of ionic and nonionic water dispersible groups. Preferred ionic water dispersed groups include cationic quaternary ammonium groups and anionic sulphonic acid groups, phosphonic acid groups and carboxylic acid groups.

Ionic water dispersible groups can be incorporated in the polyurethane in the form of a low molecular weight polyol or polyamine relative to the appropriate ionic water dispersible groups. Preferred isocyanate-reacting compounds provide water-dispersible groups which are diols having one or more carboxylic acid groups and / or sulfonic acid groups, more preferably dihydric alkoxy acids, especially 2,2-dimethyl-yl propionic acid and / o bis (2-hydroxyethyl) -5-sodiosulfoisoptalate.

The sulfonic and carboxylic acid groups may subsequently be neutralized completely or partially with a base containing a cationic charge to give a salt. If the sulfonic or carboxylic acid groups are used in combination with a dispersible group in nonionic water neutralization may not be required. The conversion of any free acid groups into the corresponding salt can be effected during the preparation of the polyurethane and / or during the preparation of an ink from the polyurethane.

Preferably the base used to neutralize any water dispersible groups is ammonia, an amine or an inorganic base. The appropriate amines are tertiary amines, for example triethylamine or triethanolamine. Suitable inorganic bases include alkali hydroxides and carbonates, for example lithium hydroxide, sodium hydroxide or potassium hydroxide. A quaternary ammonium hydroxide, for example N + (CH 3) 4 OH, can also be used. Generally, a base is used that gives the required counter ion desired for the ink that is prepared from polyurethane. For example, suitable counter ions include Li +, Na +, K +, NH 4 +, Cs +, and substituted ammonium salts, including salts of tibutyl ammonium, tetrabutyl ammonium, imidesolium, tetraethylammonium, tetrabutylphosphonium and trimethyl sulphonium. NH4 + is especially preferred. Preferred nonionic water dispersible groups are in polyoxyalkylene chain, terminal and pendant groups more preferably polyoxypropylene and polyoxyethylene groups. The examples include the groups of the formula RO (CH2CH20) nH, RO (CH2CH20) n (CH2CH (CH3) O) and CH2CH (CH3) NH2, or H2NCH (CH3) CH2 (CH (CH3) CH20) and (CH2CH20) n (CH2CH (CH3) 0) and CH2CH (CH3) NR -. ^ Where n 1 to 100, R is H or CH3, each R1 independently is H or a substituted or unsubstituted C? _? Alkyl group (especially CH 2 CH 2 -OH) and y = 2 to 15.

Optionally the mixture comprises the components (a) and (b) in step i) further comprises an isocyanate-reactive compound that is free from the water-dispersible groups. Preferably these compounds that are free of the water dispersible groups are organic polyols or polyamines having a number average molecular weight of up to 3000, more preferably up to 2000, especially from 400 to 2000. Preferred organic polyols include diols that are free of the dispersible groups in water and mixtures thereof. Such diols can be members of any of the chemical classes of polymeric diols used or proposed for use in polyurethane formulations. In particular, the diols can be polyester, polystyrene, polyoleters (other than polyethylene oxide and / or polypropylene oxide groups) polyether, polycarbonate, polyacetal, polyolefin or polysiloxane.

Additional examples of optional diols that are free of water dispersible groups include organic diols and polyols having a low number average molecular weight of 400. Examples of such diols and polyols include ethylene glycol, diethylene glycol, tetraethylene glycol, bis (hydroxyethyl) terephthalate, cyclohexane dimethanol, furan dimethanol, polyethylene glycol and polypropylene glycol.

When the mixture comprises the components (a) and (b) which contain an isocyanate-reactive compound that is free from water dispersible groups it is preferably present in relatively small amounts Preferably step i) is carried out in an organic solvent or as a mixture comprising components (a) and (b). Preferably step i) is carried out under anhydrous conditions.

The amounts relative to the components (a) and (b) are preferably selected such that the molar ratio of the isocyanate groups to the isocyanate-reactive groups is greater than 1: 1. The relative amounts of the components (a) and (b) are preferably selected such that the molar ratio of the isocyanate groups to the isocyanate-reactive groups is from 1.1: 1 to 2: 1, preferably from 1.2: 1 to 2: 1 Alternatively, a group which reacts in isocyanate terminated in prepolymer can be prepared in such a way that the molar ratio of the isocyanate groups to the isocyanate-reactive groups is from about 1: 1 to 1: 2, preferably from about 1: 1. up to 1: 1.3.

If desired, a catalyst may be used in step i) and / or step ü), to assist in the formation of the polyurethane, suitable catalysts include butyl tin dilaurate, stannous octaoate and tertiary amines as is known in the art.

An organic solvent may optionally be included in step i) to reduce the viscosity of the mixture. Preferably a water-miscible solvent is used, for example N-methylpyrrolidone, dimethyl sulfoxide, an alkyl ether of a glycol acetate, methyl ethyl ketone or a mixture thereof. Step i) is usually continued until the reaction between components (a) and (b) is substantially complete, giving either a finished prepolymer of the isocyanate terminated group or reacting in isocyanate.

The function of the component (c) is for the color and to finish the product chain of step i). In this way, component (C) is used to completely cover any excess of isocyanate end groups or reacts in isocyanate in the polyurethane resulting from the reaction of components (a) and (b) in step i). Component (c) can normally be chosen to have a functional group capable of reacting with the terminal groups in the product of step i). For example, if the product of step i) has terminal isocyanate groups, then component (c) can be selected to have a group that reacts in isocyanate, if the product of step i) has groups that react in terminal isocyanates then the component (c) ) can be selected to have an isocyanate group, and if the product of step i) has a terminal isocyanate group and a group that reacts on terminal isocyanate, then component (c) can be selected to be a mixture of dyes of each of is a group that reacts in isocyanate or an isocyanate group.

The dye preferably comprises a chromophoric group and a functional group selected from the isocyanate groups and which react in isocyanate. Nevertheless. Several such functional groups may be present in the dye with the proviso that one has a higher reactivity than the other (s) to ensure that the polyurethane chain termination is the main reaction and not the chain reaction. The functional group can be directly linked to a chromophoric group or can be linked through a linking group. An example of a linking group is an alkylene diamine linked to a chromophoric group by means of a triazine ring.

The chromophoric group preferably comprises an azo group, anthraquinone, pyrroline, phthalocyanine, polymethine, arylcarbonium, triphenoxazoin, diarylmethyl, tertiary, anthraquinone, phthalocyanine, methine, polymethine, indoaniline, indophenol, stilbene, escuiaril, aminoketone, xanthan, fluorone, acridene, quinoline, thiazole, azine, indulin, nigrosine, oxazine, thiazine, indigoid, quinoniodine, quinacr idona, lactone, pyrroline, benzodifuranone or indole. More preferably the chromophoric groups are azo groups, especially monoazo, disazo, trisazo and phthalocyanine groups. Especially preferred monoazo groups comprise two aryl groups linked by an azo group where optionally one or both and ether groups.

Preferably the dye is a dye comprising a chromophoric group and a functional group selected from the isocyanate groups and which react in isocyanate. The dye preferably comprises or is comprised from 1 to 10, more preferably 1. up to 5, especially 1, 2 or 3 of said dyes. The dye can be soluble in organic solvents and / or in water. The water solubility of the dye can be realized by the presence of acidic groups in the dye. Preferred acid groups are phosphonic, carboxylic or sulphonic acids and combinations and salts thereof.

Component (c) optionally transports water dispersible groups as described above.

The amount of component (c) used in step ii) normally depends on the ratios of components (a) and (b), the amount of finished chain desired and the depth of the desired shape.

Component (c) can also include colorless compounds having a functional group capable of reacting with component (a) or (b), for example, an isocyanate group or a group that reacts in isocyanate.

The colorless compounds have a group which reacts in isocyanate including, for example, monoalcohols, monohydrazides, monohydrazines, monoamines and monothiols. Compounds having two functional groups that react in isocyanate can be included as one of the groups that most react with an isocyanate group so that it reacts essentially as a compound that reacts in monofunctional isocyanate. An example includes ethanolamine where the amine group is more reactive than the hydroxyl group. The colorless compounds have an isocyanate group including, for example, mono alkyl isocyanates.

Preferably, from 10 to 100%, more preferably from 30 to 100% and still more than 50 to 100% by weight of component (c) comprises a colorant having functional groups capable of reacting with the components (a) or (b).

Step ii) is preferably carried out at a temperature from 10 ° C to 130 ° C, more preferably 15 ° C to 100 ° c.

Step ii) is preferably carried out by mixing the product of step i) with component (c). For example, the product of step i) may be added to a solution of component (c) or component (c) may be added to a solution of the product of step i). Alternatively component (c) can be reacted with a product of step i), followed by a dispersion of the resulting mixture in a solvent and reaction with an additional amount of component (c).

Step ii) can optionally be carried out in a solvent, preferably in water, an aqueous solvent or an organic solvent. Component (c) is preferably soluble in the solvent. The product of step ii) can then be dissipated in water.

Some chain extensions may occur during step ii) as a minor side reaction, for example with water. However, preferably the polyurethane is not deliberately extended in its chain during step ii). If step ii) is carried out in water, the conditions are preferably selected in such a way that the substantial chain extension of the polyurethane does not occur.

Polyurethane dissipable in colored water may contain additional bonds in addition to urethane bonds, for example urea, amide, thiourea or thiourethane bonds.

Preferably, the color-water-dissipable polyurethanes according to a first aspect of the present invention are obtained by the established processes.

Preferably, the water-dissipatable color polyurethane of the present invention (and any of its resulting inks) is yellow, magenta, cyan or black.

The dissolvable polyurethane e? The colored water of the present invention can be purified if desired in the usual manner. for the colorants used in ink jet printers. For example, a mixture of the dissipatable polyurethane in water of color and water can be purified by ion exchange, filtration, reverse osmosis, dialysis, ultra filtration or a combination thereof. In this way, one can remove co-solvents used for polymerization, low molecular weight salts, impurities and free monomers.

In a second aspect of the present invention, there is provided an ink comprising a color-dissipable polyurethane in accordance with the first aspect of the present invention and a liquid medium. A preferred ink comprises: (a) from 0.25 to 30 parts of a water-dissipatable polyurethane of color of the first aspect of the present invention; and (b) up to 99.75 parts of a liquid medium; where all the parts are by weight and the number of parts of (a) + (b) = 100.

The number of parts of component (a) preferably is from 0.5 to 28, more preferably from 2 to 25, and especially from 2.5 to 20 parts.

The inks according to a second aspect of the invention can be prepared by mixing the dissipatable polyurethane in colored water with the liquid medium. Appropriate techniques are well known in the art, for example agitation, ultra sonication or mixing of the mixture. The water-dissolvable polyurethane mixture and the liquid medium is preferably in the form of a dispersion, emulsification, suspension, solution or mixture thereof.

The water-dissipatable polyurethane in colored water is preferably mixed with a first liquid medium, followed by mixing the resulting mixture, with a second liquid medium.

The liquid medium preferably comprises water, a mixture of water and organic solvent or a water-free organic solvent. For example, polyurethane dissipable in water can be added to water followed by the addition of one or more organic solvents. Preferably, the first liquid medium is an organic solvent and the second liquid medium is water or a mixture comprising water and one or more organic solvents.

When the liquid medium comprises a mixture of water and an organic solvent, the weight ratio of the water to the organic solvent is preferably from 99: 1 to 1:99, more preferably from 99: 1 to 50:50 and especially from 95: 5. until 60:40.

It is preferred that the organic solvent present in the mixture of water and organic solvent be a water miscible organic solvent or a mixture of such solvents. Preferred water miscible organic solvents include C 1-6 alkanoles, preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol and cyclohexanol; linear amides, preferably dimethyl formamide or dimethyl acetamide; ketones and alcohols of ketones, preferably acetone, methyl ether ketone, cyclohexanone and diacetone alcohol; ethers miscible in water, preferably tetrahydrofuran and dioxane; diols, preferably diols having from 2 to 12 carbon atoms, for example pentamo-1,5-diol, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexene glycol and thiodiglycol and oligo- and poly-alkylene glycols, preferably diethylene glycol, triethylene glycol, polyethylene glycol and polypropylene glycol; triols, preferably glycerol and 1,2,6-hexantriol; mono-C? alkyl ethers of diols, preferably mono-C? alkyl ethers of diols having from 2 to 12 carbon atoms, especially 2-methylxyl anol, 2- (2-ethoxyethoxy) ethanol, - (2-ethoxyethoxy) -et anol, 2- [2- (2-methoxyethoxy) ethanol, ethoxy] ethanol, 2- [2- (2-ethoxyethoxy) ethanol, et oxy] ethanol, and ethylene glycol monoal lieter; cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-1-2-pyrrolidone, caprolactam and 1,3-dimetimidazolidone; cyclic esters preferably caprolactone; sulfoxides, preferably dimethyl sulfoxide and sulfolane. Preferably the liquid medium comprises water and 2 or more, especially from 2 to 8, water soluble organic solvents.

Particularly preferred water-soluble organic solvents are cyclic amides, especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone; diols, especially 1,5-pentane diol, ethylene glycol, thiodiglycol, diethylene glycol and triethylene glycol; and mono-C?-alkyl and C?-alkyl ethers of diols, more preferably mono-C? _4-alkyl ethers of diols having from 2 to 12 carbon atoms, especially 2-methoxy-2-ethoxy -2 -ethoxyethanol.

When the liquid medium comprises a water-free organic solvent, (this is less than 1% water by weight) the solvent preferably has a boiling point from 30 ° to 200 ° C, more preferably from 40 ° to ~ 150 ° C , especially from 50 to 125 ° C. The organic solvent may be non-miscible in water, miscible in water or a mixture of such solvents. Water-miscible organic solvents are preferably any of the water-miscible organic solvents described above. Preferred non-miscible solvents in water include, for example, aliphatic hydrocarbons; esters, preferably ethyl acetate; chlorinated hydrocarbons, preferably CH2C12; and ethers, preferably diethyl ether; and mixtures thereof.

When the liquid medium comprises an organic solvent immiscible with water, preferably a polar solvent is included because it increases the solubility of the polyurethane in the liquid medium. Examples of polar solvents include C?-Alco alcohols. In view of the aforementioned preferences, it is especially preferred that when the liquid medium is a water-free organic solvent, it comprises a ketone (especially methyl ethyl ketone) and / or an alcohol (especially a C 1 -4 alkanol, more especially ethanol or propanol).

The water-free organic solvent can be a simple organic solvent or a mixture of two or more organic solvents. It is preferred that when the medium is a water-free organic solvent this is a mixture of 2 to 5 different organic solvents. This allows a medium to be selected that gives good control over the drying characteristics and storage stability of the ink.

The medium of the ink comprises a water-free organic solvent, and is particularly useful when fast drying times are required and particularly where the printing on its hydrophobic non-absorbent substrates, for example plastics, metal and glass.

A preferred liquid medium comprises: a) from 75 to 95 parts of water; and b) from 25 to 5 parts of the total of one or more selected solvents of diethylene glycol, 2-pyrrolidone, thiodiglycol, N-methyl, lyrrolidone, cyclohexanol, caprolactone, caprolactam and pentan-1, 5-diol; where the parts are by weight and the sums of the parts of (a) and (b) = 100.

The ink may also contain an active taut agent. This helps to dissipate dissipable polyurethane in colored water in addition to the dissipation caused by dispersant groups coming from component ii) of dissipable polyurethane in colored water. Optionally, the ink may also contain additional additives conventionally used in jet printing inks, for example conductive agents, defoamers, antioxidants, corrosion inhibitors, bactericides and viscosity modifiers.

The ink preferably has a pH from 3 to 11, more preferably from 4 to 10. Such a pH can be obtained by the addition of a base, acid or a buffer solution. When a base is used, this is preferably the base that was used to neutralize the anionic dispersion group during the preparation of the polyurethane.

The viscosity of the ink is preferably less than 20 cp, more preferably less than 10cp to 20 ° C.

The ink is preferably filtered through a filter having a main pore size of below 10 μm, preferably below 5 μm, more preferably below 2 μm, especially about 0.45 μm. In this way, the particulate matter is removed by otherwise blocking the fine nozzle in an inkjet printer.

The inks of the second aspect of the present invention have the advantage that they are suitable not only for use in piezoelectric ink jet printers, but also for use in thermal and continuous ink jet printers. This creates a discrete drip on the substrate with a small tendency to diffusion.

Consequently, image forms can be obtained with excellent print quality and very little of any mixing between printed colors side by side. Additionally, the inks show good storage stability, solids to light and moisture and solids for both an acid and alkaline enhanced writing.

A further aspect of the invention provides a process for printing an image on a substrate comprising applying thereto an ink containing a water-dissipatable polyurethane of the present invention by means of an inkjet printer.

The ink used in this process is preferably as defined in the second aspect of the present invention.

The ink jet printer preferably applies the ink to the substrate in the form of a drip running through a small nozzle in the substrate. Preferred inkjet printers are piezoelectric ink jet printers and thermal ink jet printers. In thermal ink jet printers, programmed heat pulses are applied to the ink in a reservoir by means of a resistor adjacent to the nozzle, thereby causing the ink to eject in the form of small droplets directed towards the substrate during the Relative movement between the substrate and the nozzle. In piezoelectric ink jet printers, the oscillation of a small crystal causes ejection of the ink from the nozzles.

The substrate preferably is paper, plastic, a cloth, metal or glass, more preferably paper, a glide of a top projector, a material, textile, especially paper.

The preferred papers are flat, covered or treated papers that may have an acidic, alkaline or neutral character. More preferably the substrate is a flat or covered paper.

According to a further description of the invention there is provided an ink jet printer cartridge containing an ink as defined above. ~ The invention will now be described only as an example. All parts and percentages are by weight unless otherwise specified.In the examples the compounds referred to with reference to the Cl numbers are the dyes identified by these numbers in the international color index, 3rd edition, 3rd revision.

Example 1: Preparation of a color polyurethane dissipable in magenta water Step i): A magenta dye of formula 1 was prepared as the ammonium salt as described below: Formula 1 A pre-filtered solution d'e 1 red 11 reactive Cl (a dichlorot riazinyl dye) (120 parts) was dissolved in distilled water (1500 parts). N-Butylamine (8 parts) was dissolved in acetone (50 parts) and added dropwise while maintaining the temperature at 25 ° C and the pH at 8.4 by the addition of 2N NaOH. The mixture was stirred for an additional hour and then an additional charge of n-butylamine (2 parts) in acetone was added. (20 parts) while maintaining the temperature at 25 ° C and the pH at 8.4. After an additional hour, two additional charges of n-butylamine (2 parts) in acetone (20 parts) were made before the reaction as shown to be completed by high performance liquid chromatography (HPLC). The resulting intermediate was precipitated from the cooled reaction mixture by the addition of a 30% aqueous salt solution and an acidification of pH 2 by the addition of 2N hydrochloric acid. The intermediate was asylated by filtration and washed with IN hydrochloric acid. The intermediate was dissolved in water (1000 parts) and added dropwise to a stirred solution of ethylene diamine (60 parts) in distilled water (1000 parts) at 70 ° C. The mixture was stirred at 70 ° C for two additional hours and at room temperature for 2 days at which HPLC analysis indicated that no starting material was left over. Sodium chloride (10% w / w) was added to the mixture followed by acidification to pH 2.5 by the addition of concentrated hydrochloric acid. The resulting product was isolated by filtration, washed with a little cold water, dried at 50 ° C, mixed in methanol, isolated by filtration, washed with a little cold water and methanol and dried. The product was dissolved in distilled water, filtered through a cascade of filters (microfiber glass GF / A, GF / F and membrane) to 0.45 microns and then scrubbed by reverse osmosis using a 500 PM cutoff membrane. and evaporated to dry to yield the dye of formula 1 (37.5 parts) Step ii): The dye of formula 1 step i) in the form of an ammonium salt was then used for a finished chain polyurethane prepolymer using the method as described in steps i) and ii) below and the components described in the following table 1.

TABLE 1 Step Preparation of a polyurethane prepolymer Components 1, 2, 3 and 4 were charged to a stirred reaction vessel under a nitrogen atmosphere and heated to 90 ° C, then component 5 was added. The reaction "became exothermic by about 3 ° C and then it was maintained at 90-95 ° C for 3 hours to give a polyurethane prepolymer.After 3 hours the NCO content of the reaction mixture was found to be 3.74% The mixture was reduced in solids up to 50% using N-methylpyrrolidone.

Step ii): Finishing the chain with a dye The polyurethane prepolymer from step i) (6.32 g) at 90 ° C was dispersed in a mixture of components 6 and 7 (40.55 g) initially at 30 ° C.

The mixture was stirred for an additional 1.5 hours and then cooled to room temperature before starting to filter through a 5.0 μm filter cloth.

The resulting color water dispersible polyurethane was found to have a solids content of 8.46%, a pH of 9.96 and a Pm determined by gel permeation chromatography of 4233 (Mn = 1446).

Example 2: Preparation of a color polyurethane dissipable in water Step i) _: Preparation of dye 2 Formula 2 The dye of formula 2 was prepared as described in steps a), b) and e) below.

Step a) Preparation of a mono-azo intermediate of Formula 3 Formula 3 -Anois ophthalic acid (109 parts) and sodium nitride (46 parts) were dissolved in water (1000 parts) with the addition of 2N sodium hydroxide to pH 7.7. The resulting solution was slowly added to concentrated hydrochloric acid (180 parts) at 0-10 ° C. The mixture was stirred for 2 hours at 0-10 ° C until reacted to give a diazonium salt. The excess nitric acid was destroyed by the addition of sulfamic acid until A failure in the paper starch was shown as an immediate change.

A solution of 2, -dimet oxyaniline (92 parts) in methylated alcoholic paints (2000 parts) was added slowly to the previous diazonium salt and stirred at 0-10 ° C. The mixture was maintained at a temperature of 0-10 ° C by the addition of ice during the addiction and then stirred for 2 hours at this temperature. Water (4000 parts) was added and the mixture was stirred overnight at room temperature The mixture was filtered and the resulting precipitate was isolated by filtration and stirred in 2N hydrochloric acid (1500 parts) .The resulting mixture was filtered and the precipitate in this way obtained it was dried in an oven at 40 ° C to produce the compound of Formula 3 (364 parts).

Step Preparation of a Formula 4 Naphthalene Intermediate Formula 4 A mixture of 2, 8-dihydroxy-6-naphthalene sulfonic acid (263 parts), sodium hydrogen sulfide (259 parts), water (900 parts) and 1, diaminooctane (400 parts) was reacted while stirring at 80 ° C for 20 hours and then at 20 additional hours at 95 ° C. The reaction was allowed to cool overnight and was filtered. The resulting precipitate was isolated by filtration and stirred in water (500 parts) and 2N sodium hydroxide (750 parts) for 15 minutes, hydrochloric acid "2N (300 parts) was added and the precipitate was filtered. water (500 parts) and 2N sodium hydroxide (1000 parts) were heated to 50 ° C. 2N hydrochloric acid was added and the precipitate was filtered at 40 ° C. The precipitate was dried in an oven at 70 ° C. to produce the Naphthalene intermediary required (111 parts).

Step c): Preparation of the dye of Formula 2 The product of step a) (105 parts) and sodium nitride (20 parts) were dissolved in water (1000 parts) by adding 2N sodium hydroxide to a pH of 9.0. The resulting solution was added to concentrated hydrochloric acid (100 parts) and water (400 parts) and reacted while stirring with a high side-shaker at room temperature for 1.25 hours to give the diazonium salt. The excess nitric acid was destroyed by adding sulfamic acid until the paper starch showed no immediate change.

The diazonium salt was added slowly to a solution of the product from step b) (96 parts) in water (1000 parts) which had previously been adjusted to pH 11 using sodium carbonate (50 parts) and 2N sodium hydroxide. The temperature during the addition was maintained at 0-10 ° C by adding ice and the pH was maintained at 10-11 by adding 2N sodium hydroxide.The solution was stirred for 2 hours at 0-10 ° C and overnight at room temperature. The solution was adjusted to a pH of 6.5 with concentrated hydrochloric acid and the precipitate was filtered.The resulting precipitate was dissolved in water (500 parts) with the addition of concentrated ammonia (750 parts) .Concentrated hydrochloric acid was added (500 parts) and the precipitate was filtered.This process was repeated and the resulting precipitate was suspended in water (700 parts) and concentrated ammonia (200 parts) .The suspension was dialyzed to <100μs / cm and sieved at 60 ° C using a GF / D glass microfiber filter paper The solvent was evaporated to dry at 80 ° C to yield the Formula 2 dye as the ammonium salt (127 parts).

An ion exchange column packing with a highly acidic resin (H + form) was stirred with an aqueous solution of triethylamine (5% v / v) until the eluent tested basic with pH indicator paper 8-10. The ammonium salt of the dye of formula 2 (66 parts) was dissolved in water (1300 parts) with the addition of triethylamine to a pH of 9.0 and passed through the column. Water was flowed through the column until the eluent appeared to have very little color. The solvent was evaporated to dry to yield the triethylamine salt of the Formula dye 2 (72 parts).

Stage ii) The triethylamine salt of the dye of Formula 2 prepared in step i) was then used to terminate the polyurethane prepolymer chain using the method as described below in steps i) and ii) and the components as described above. continuation in table 2.

TABLE 2 Step i): Preparation of polyurethane prepolymer The components 1, 2, 3 and 4 were charged to a stirred reaction vessel under a nitrogen atmosphere and heated to 100 ° C. The reaction mixture was then maintained at 100 ° C for 3 hours to give a polyurethane prepolymer. Component 5 was then added to reduce the general solids up to 50%. A sample of the reaction mixture (4.0 g) was removed to determine the% NCO content that was found to be 2. 14% NCO. The component was then added to a portion of the prepolymer (14.78 g) at 70 ° C and this temperature was maintained for an additional 30 minutes. The reaction mixture was then cooled to 40-45 ° C.

Step ii): Chain termination with a dye Components 7 and 8 were added to the reaction mixture prepared in step ii), step i). The reaction mixture was then reheated to 70 ° C and kept at this temperature for an additional 30 minutes to give a colored polyurethane polymer solution.

The polymer solution (58.04 g) at 70 ° C was dispersed in 84.35 g of the distilled water initially at 30 ° C. During the addition of the polymer solution to the water to give a dispersion, the temperature of the water rose to about 49.1 ° C. The dispersion was stirred for an additional hour, cooled to room temperature and filtered through a 50 μ filter cloth.

The resulting dispersion of the dissipatable polyurethane in color water was found to have a solids content of 9.42%, a pH of 6.13, and a Pm as determined by gel permeation chromatography of 10,180 (Mn = 5008).

Preparation of inks of dissipatable polyurethanes in colored water prepared in groups 1 and 2.

The colored polyurethane polymers prepared in Examples 1 and 2 respectively were diluted with water (150 parts) and adjusted to a pH of 10 using concentrated ammonia. The resulting solutions were screened through a cascade of filters (microfiber glass GF / A, GF / F and membrane) up to 0.45 microns and then purified by reverse osmosis using a "100,000 PM cutoff membrane.The solvent was evaporated to dry at 70 ° C to give dissipatable polyurethanes in purified color water.

The inks were prepared by dissolving 15 parts of the dye [ie, the water-dissipable polyurethanes of purified color of Examples 1 and 2 respectively] in a stock solution of 9 parts of water and 1 part of 1-methyl-2-pyrrolidinone. with the addition of concentrated ammonia to give a pH of 9-10. The inks were filtered through a 0.45 micron membrane filter, and a series of vertical and horizontal bars were printed on a 100 g / m2 Conquistador high white flat paper from Arjo-Wiggins Ltd; White Gilbert Bond paper or white Xerox acid paper using an HP 560 thermal ink jet printer to give the test prints. The properties of the resulting test impressions are shown in Table 3 below.

Table 3 -C- Enhancement test The test prints prepared above were tested for stain resistance for enhanced writings. Yellow enhanced scripts (acidic and alkaline) were used to draw a horizontal line through the series of vertical printed bars. The amount of ink smeared on the white paper between the vertical bars was evaluated visually. The prepared prints of the inks containing the water-dissipable color polyurethanes prepared in Examples 1 and 2 were fast for both acidic and alkaline enhanced scripts.

Solidity to Moisture The moisture fastness was determined as follows; 0.5 cm3 of water was circulated, repeating the moisture fastness of the test prints prepared previously 24 hours after printing. The moisture solids were marked on a scale from 1 to 10, with one representing poor moisture fastness and 10 not producing discoloration on the white paper.

Coordinated, bright colors and optical density Coordinated colors, L a b and optical density were measured in the test prints prepared above using a 938 X-rite rofhotometer.

The optical density was measured from the strength of the color "on a logarithmic scale.

Coordinated color defined brightness and color on a color scale, where "a" is a measure of redness (+ a) or greenness (-a) and "b" is a measure of yellowing (+ b) or bluing (-b). The coordinates "a" and "b" approach zero for neutral colors (white, gray and black). The maximum values "a" and "b" are the most saturated color.

The bright "L" is measured on a scale from zero (white) to 100 (black).

Inks Additional inks can be prepared having the formulations described in Table 4 below where the following abbreviations are used. Water can be included in each formulation to be the total number of parts greater than 100. These inks can be applied to flat paper using an ink jet printer.

FRU: fructose PU *: Polyurethanes dissipatable in colored water as prepared in examples 1 and 2. The number of parts by weight of PU is shown in parentheses. BZ: Benzyl alcohol DG: Diethylene glycol DMB: Diethylene glycol monobutyl ether AC: Acetone IPEA: Isopropyl alcohol M: Methanol 2P: 2-pyrrolidone MBC: Methyl ilbutyl ketone SUR: Surfinol 465 (a surface-active agent) PHO: K2P04 TEN: triethanolamine NMP: N-methylpyrrolidone TDG: thiodiglycol CAP: caprolactam BC: butylcelosolve GLI: glycerol NH: sodium hydroxide AS: ammonium sulfate (NH4) 2S04 MA: methyl amine CH3NH2 Table 4 ? (Water is included in each formulation to make the total number of parts up to 100) It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (12)

Claims

1. A color dissipable polyurethane in water, obtained from a process characterized in that it comprises the steps of: i) reacting a mixture comprising the components (a) and (b) wherein the component (a) is at least one organic polyisocyanate and the component (b) is at least one compound that reacts to the isocyanate by propounding dispersible groups; and ii) terminating the product chain of step i) with component (c) wherein component (c) comprises a dye having a functional group capable of reacting with components (a) or (b).

2. The polyurethane according to claim 1, characterized in that step ii) is carried out in water.

3. The polyurethane according to claim 1 or 2, characterized in that step ii) is carried out at a temperature of 10 ° C to 130 ° C.

Four . The polyurethane according to claim 1 or 3, characterized in that step ii) is carried out in an organic solvent.

5. The polyurethane according to any of the preceding claims, characterized in that it is soluble in water.

6. The polyurethane according to any of the foregoing indications, characterized in that it has a pM less than 50,000.

An ink, characterized in that it comprises a polyurethane according to any of claims 1 to 6, and a liquid medium

8. The ink according to claim 7, characterized in that it has a viscosity less than 20cp at 20 ° C.

9. The ink according to claim 7 or 8, characterized in that it is filtered through a filter having a main pore size of below 10 μM.

10. The ink according to claim 7 to 9, characterized in that it is yellow, magenta, cyan or black.

11. A process for printing an image on a substrate, characterized in that it comprises applying thereto an ink containing a polyurethane according to any of claims 1 to 6 by means of an ink jet printer.

12. An ink jet printer cartridge characterized in that it contains an ink according to any of claims 7 to 10.