WO2004053005A1

WO2004053005A1 - Washable waterborne ink

Info

Publication number: WO2004053005A1
Application number: PCT/NL2003/000788
Authority: WO
Inventors: Pascal Maria Hubert Pierre Tijssen
Original assignee: Dsm Ip Assets B.V.
Priority date: 2002-12-06
Filing date: 2003-11-10
Publication date: 2004-06-24
Also published as: AU2003279628A1

Abstract

The invention relates to a washable waterborne ink comprising a copolymer or a salt thereof of an aliphatic carboxylic acid-functional aliphatic monomer and an non-functional aliphatic monomer in a weight ratio between the carboxylic acid-functional aliphatic monomer and the non-functional aliphatic monomer, such that it allows water solubility and simultaneously imparts a good dye blocking effect.

Description

WASHABLE WATERBORNE INK

The invention relates to a washable waterbome ink comprising a polymer having acid functional groups.

A washable waterbome ink is in this application understood to be a colored composition, including a marker composition and a paint, comprising a colorant and water as a liquid carrier, which composition can be applied on a surface for writing, painting and/or decorative purposes and which composition, after being applied and dried, can be removed through contact with water and/or detergents. Washable waterbome inks are used, for instance, in markers and felt-tip pens. An important requirement for such an ink, in particular when intended for use by children, is that the colorant has a good affinity to certain substrates, such as paper, but has low affinity to skin and clothing and can easily be removed therefrom.

The washability of a washable ink generally depends strongly on the solubility of the colorants used. Generally, soluble colorants or dyes are used. However, in many cases the performance is still insufficient. To enhance the washability of a waterbome ink, the ink often comprises a so-called washability- enhancing additive or dye blocker. In the past, sulphonated phenol/formaldehyde condensation products were used as dye blocker. As described in US-64532584 these products suffered from a high color themselves and as such tend to have an adverse effect on the brightness of some shades of the target ink composition producing a shade with a dull dirty appearance. This problem is particularly noticed with regard to lighter color shades. Other dye -blocking compounds include polyaromatic sulfonates _, and their salts, such as described in US-5116410 and styrene-maleic anhydride copolymers and salts thereof, such as described in US-64532584; the latter patent publication claims with styrene-maleic anhydride copolymers and salts thereof to have solved the color problem and dulling effect of sulphonated phenol/formaldehyde condensation products. It is furthermore reported that the dye -blocking styrene-maleic anhydride copolymers and salts thereof, due to a limited molecular weight, can be added in very high amounts without increasing the viscosity in a deleteriously high amount for standard marker performance. With the increasing use of washable waterbome inks, there is also an increasing demand for suitable dye blockers that can be used in such washable waterbome inks. Furthermore, modern ink compositions, especially marker pens used for highlighting text or relevant passages therein, regularly comprise fluorescent dyes. A disadvantage of the known dye blockers based on sulphonated phenol/formaldehyde condensation products, polyaromatic sulfonates and their salts, and styrene-maleic anhydride copolymers and salts thereof, is that they reduce the intensity of the color of the fluorescent dyes. As a result thereof, either the amount of dye blocker in the ink composition should be kept limited, more fluorescent dye would be needed, and/or the resulting color of the ink is affected.

The aim of the invention is to provide a washable waterbome ink comprising a dye blocker which has no adverse effects on the color intensity of fluorescent dyes, or in a lesser extent than the known dye blockers.

This aim has been achieved with a washable waterbome ink comprising a copolymer or a salt thereof of an aliphatic carboxylic acid-functional aliphatic monomer and an non-functional aliphatic monomer in a weight ratio between carboxylic acid-functional aliphatic monomer and non-functional aliphatic monomer, such that it allows water solubility and simultaneously imparts a good dye-blocking effect.

The washable waterbome ink according to the invention provides a good washability enhancing performance in waterbome inks, without significantly reducing the color intensity of fluorescent dyes and allowing production of inks with bright color shades.

With a carboxylic acid-functional aliphatic monomer is understood, here and hereafter, a carboxylic acid-functional aliphatic monomer having a single unsaturated polymerizable group.

The term non-functional aliphatic monomer is understood to be, here and hereafter, an aliphatic monomer having a single unsaturated polymerizable group, and not having a carboxylic acid-functional group. The non-functional aliphatic monomers may comprise ester, amide and/or hydroxyl groups. Such an aliphatic monomer having a single unsaturated polymerizable group may be a diene, such as butadiene or isoprene, comprising two double bounds, of which only one double bound is converted in a single covalent bound during polymerization, and the other remaining double bond is hydrogenated after polymerization, thus before the copolymer is used in the washable waterbome ink.

Typically, the copolymer in the washable waterbome ink according to the invention comprises 10-99 weight % of the carboxylic acid-functional aliphatic monomer and 90-1 weight % of the non-functional aliphatic monomer, the weight % relative to the total weight of the copolymer. The amounts used may also be somewhat higher or lower, depending on the specific carboxylic acid-functional aliphatic monomer and non-functional aliphatic monomer used. Preferably, the copolymer comprises 20- 99 weight % of the carboxylic acid-functional aliphatic monomer respectively 80-1 weight % of the non-functional aliphatic monomer, more preferably, 25-50 weight % respectively 75-50 weight %.

The copolymer has a carboxyl equivalent weight of between 60 g/mol and 600 g/mol, preferably between 80 g/mol and 400 g/mol and most preferably between 100 g/mol and 200 g/mol. A too low a content of carboxyl acid-functional groups, respectively a too high a carboxyl equivalent weight, limits the solubility of the copolymer or salt thereof; a too high a content of carboxyl acid-functional groups, respectively a too low a carboxyl equivalent weight, limits the effectiveness of the copolymer or the salt thereof as a dye blocker.

The copolymer in the washable waterbome ink according to the invention may have a molecular weight within a wide range. Typically, though not limited thereto, the weight average molecular weight is between 600 g/mol and 50.000 g/mol, preferably between 600 g/mol and 25.000 g/mol and more preferably between 600 g/mol and 10.000 g/mol, and most preferably between 600 g/mol and 5.000 g/mol. An advantage of a molecular weight of the copolymer below 5000 g/mol is that the waterbome ink composition comprising the copolymer may comprise more of the copolymer without exhibiting an exorbitantly high viscosity and allowing the ink to perform properly and permit adequate flow of the composition through the tip of a marker pen. The greater the amount of copolymer is, the greater is the ability to prevent permanent staining on certain substrates. A further advantage of the copolymer with the lower molecular weight is that it can be added in high amounts without a significant dulling effect within the different color shades produced and without a adverse effect on the color intensity of fluorescent dyes.

Suitable carboxylic acid-functional aliphatic monomers, which may be present in the copolymer that can be used in the washable waterbome ink according to the invention are, for example, monocarboxylic acid-functional unsaturated monomers, such as acrylic acid and methacrylic acid, dicarboxylic acid-functional unsaturated monomers, such as maleic acid, itaconic acid and fumaric acid, and a half-ester and an anhydride thereof, and mixtures thereof.

Suitable aliphatic alcohols that may be used in the half-ester of a dicarboxylic acid-functional unsaturated monomer are, for example, primary, secondary and tertiary aliphatic alcohols, wherein the aliphatic group may be a linear or a branched group. Examples of suitable aliphatic alcohols include methanol, ethanol, propanol, isopropanol, n-butanol, iso-butanol, tert-butanol, 2-ethylhexanol, n- laurylalcohol, stearylalcohol. Examples of suitable half-esters include methyl-maleic acid ester, ethyl- maleic acid ester, 2-ethylhexanol maleic acid ester, n-laurylalcohol maleic acid ester, stearylalcohol maleic acid ester, propyl itaconic acid ester, iso-butyl itaconic acid ester, 2-ethylhexanol-itaconic acid ester, methyl-fumaric acid and 2-ethylhexanol-fumaric acid ester.

Preferably, the carboxylic acid-functional aliphatic monomer is chosen from the group consisting of acrylic acid, methacrylic acid, maleic acid and the anhydride thereof, fumaric acid, itaconic acid and the anhydride thereof, and mixtures thereof. More preferably, the carboxylic acid-functional aliphatic monomer is acrylic acid, maleic acid or the anhydride thereof. The advantage is that these monomers and copolymers thereof are generally available.

Suitable non-functional aliphatic monomers, which may be present in the copolymer that can be used in the washable waterbome ink according to the invention are, for example, esters of aliphatic alcohols with carboxyl acid-functional monomers, amides of aliphatic amines and carboxyl acid-functional monomers, α- olefins, dienes, and cyclic olefins, and mixtures thereof. Carboxyl acid-functional monomers that may be used in the non-functional aliphatic monomers comprising an ester with an aliphatic alcohol, are, for example, monocarboxylic acid-functional unsaturated monomers, such as acrylic acid and methacrylic acid, and dicarboxylic acid-functional unsaturated monomers, such as maleic acid, itaconic acid and fumaric acid. When the non-functional aliphatic monomer is based on a dicarboxylic acid- functional unsaturated monomer, the monomer has the form of a diester.

Suitable aliphatic alcohols that may be used in the non-functional aliphatic monomers comprising an ester group, are the same as mentioned above for the carboxylic acid-functional aliphatic monomers based on a half-ester of a dicarboxylic acid-functional unsaturated monomer.

Examples of suitable non-functional aliphatic monomers comprising an ester group include methylacrylate, ethylacrylate, n-butylacrylate, iso-butylacrylate, 2- ethylhexylacrylate, laurylacrylate, methylmethacrylate, ethylmethacrylate, n- butylmethacrylate, iso-butylmethacrylate, 2-ethylhexylmethacrylate, laurylmethacrylate, dimethylmaleate, diethylmaleate, di-n-butylmaleate, di-2-ethylhexylmaleate, di- octylmaleate, dilaurylmaleate.

Examples of suitable α-olefins are, for example, C2-C24 α-olefins and include ethene, propene, 1-butene, 1-isobutene, 1-octene, 1-tetradecene, and tetracosene.

Examples of suitable dienes are, for example, butadiene and isoprene. If the copolymer in the washable waterbome ink according to the invention comprises a diene, the diene in the copolymer has to be in the hydrogenated form.

Examples of suitable cyclic olefins are, for example, norbornene and ethylnorbomene.

Preferably, the non-functional aliphatic monomer is an ester of an aliphatic alcohol with a carboxyl acid-functional monomer or an α-olefin. Use of the copolymer, comprising such a monomer, as dye blockers in a waterbome ink provides highly effective prevention of permanent staining by the ink on substrates such as skin, clothing, and the like.

More preferably the non-functional aliphatic monomer is an α-olefin. The advantage is that this allows even better washability results. More preferably, the α-olefin is a C2-C12-α-olefin. The advantage of a washable waterbome ink according to the invention comprising a copolymer based on C2-C12-α-olefin is that it has better solubility and/or that good solubility can be obtained at lower carboxylic acid content.

In another preferred embodiment of the invention the copolymer is a copolymer of maleic acid or the anhydride thereof and an α-olefin, more preferably a copolymer of maleic acid, or the anhydride thereof, and a C2-C12-α-olefin, and most preferably a copolymer of maleic acid, or the anhydride thereof, and the C2-C12-α- olefin in a mole ratio between 1 :1 and 1 :3. The advantage is that the washable waterbome ink comprising the copolymer of maleic acid and the C2-C12-α-olefin in a mole ratio between 1 :1 and 1 :3 has an excellent washability enhancing performance. The performance is in general as good as, and in many cases even better than, dye blockers based on styrene-maelic anhydride copolymers. The washable waterbome ink typically comprises the copolymer or the salt thereof in the form of a solid, a paste or a solution. For attaining the right solubility of the copolymer, it might be necessary to use the copolymer in the form of a salt comprising a neutralizing agent or to dissolve the copolymer in an alkaline solution comprising a neutralizing agent. For preparing the salt or for preparing the alkaline solution, a neutralizing agent chosen from the group consisting of ammonia, an amine and a metal hydroxide chosen from lithium hydroxide, sodium hydroxide and potassium hydroxide, may be used. Generally, the salt of the copolymer is a sodium salt. Also for preparing the alkaline solution typically sodium hydroxide is used. The ratio between copolymer and neutralizing agent in the salt or in the alkaline solution used for preparing the solution may be varied over a large range, as long as it is sufficient for dissolving the copolymer. Preferably the ratio is chosen in such a way that the ratio in molar equivalents between the amount of hydroxide, ammonia or amine, and the number of carboxyl groups in the copolymer is between 0,5 and 2,0 more preferably between 0,75 and 1 ,0. A too low a ratio will limit the solubility, whereas a too high a ratio will result in a unnecessary high excess of hydroxide and a highly alkaline ink composition.

Typically, the waterbome ink comprises the copolymer in an effective amount to attain at least a minimal effect of dye blocking. This amount or higher amounts for attaining a higher level of dye blocking effect, can easily be determined empirically by the man skilled in the art of formulating waterbome ink compositions.

The waterbome ink according to the invention typically comprises at least one colorant. The colorant in the inventive ink may be selected from pigments, dyes, inks and the like. A pigment is understood to be a non-soluble colorant. It may be used, for example, in a dispersed form. A dye is understood to be a soluble colorant. Any type of such compounds may be utilized, including, but not limited thereto, polymeric dyes, acid dyes, and the like.

In a preferred embodiment the colorant is a dye, more preferably a fluorescent dye. The advantage of the waterbome ink according to the invention comprising a fluorescent dye is that the ink has good washability while the colour strength of the fluorescent dye is well-maintained.

In another preferred embodiment of the waterbome ink, the colorant is a polymeric dye consisting of a colorant bonded to a water-soluble polymer. The advantage is that the colorant itself does not need to be soluble or washable, while the waterbome ink comprising said polymeric dye and the copolymer described above, has good washability, even when the dye is based on a colorant which itself is not soluble or washable, and which washability is better than for the corresponding ink without the copolymer.

Typically, the colorant bonded to the water-soluble polymer is bonded via a covalent bond, via hydrogen bonds or via an ionic bond. In a more preferred embodiment, the colorant is bonded to the water- soluble polymer via an ionic bond or a covalent bond. Ionic bond formation occurs as a result of coulombic force between cations and anions when these ions come into close proximity of each other. In other words, colorants with cationic groups are attracted to anionic groups on the water-soluble polymer, while colorants with anionic groups are attracted to cationic groups on the water-soluble polymer. It can be applied to colorants with ionic groups; several of these colorants are only soluble in polar solvents, in particular water, and generally to a limited extent only. The advantage of an ionically bonded colorant is that such a bond is very strong. Bonding of the colorant to the water-soluble polymer via an ionic bond can advantageously be applied to enhance the solubility both in water as well as in organic solvents and thereby to enhance the washability.

Examples of suitable anionic groups capable of forming ionic groups are, for example, carboxylic acid, sulfonic acid, phosphoric acid, phosphinic acid, or salts thereof.

Preferably, the anionic group is a sulfonic acid group or a carboxylic group, or a salt thereof. A carboxylic acid group is advantageously applied as part of the water-soluble polymer, since water-soluble polymers with carboxylic acid groups can be easily prepared. The advantage of a sulfonic acid group, or a salt thereof, is that stronger ionic bonds are formed. A further advantage is that many known dyes already contain a sulfonic acid group, or a salt thereof.

Examples of suitable cationic groups capable of forming ionic bonds are amine groups and salts thereof, and oxazolinium ions. Preferably, the amine group is a tertiary amine group when part of the water-soluble polymer. The advantage is that tertiary amine groups can be build-in in the water-soluble polymer, without the risk of reaction with carboxylic groups resulting in amide formation. Oxazolinium ions can also be used advantageously as the cations, since these ions can easily be formed in β- hydroxyalkyl-amide functional water-soluble polymers.

Suitable dyes bearing cationic groups are, for example, dyes comprising a quaternary ammonium group, a pyridinium groups or a thiazolium group.

Examples of suitable colorants with the preferred ionic group can simply be selected from known dyes, e.g. from the list in The Sigma-Aldrich Handbook of Stains, Dyes and Indicators.

Within the group of dyes capable of forming ionic bonds a specific class is formed by the so-called acid dyes. The term acid dye does not describe a particular chemical type of dye, but rather refers to the traditional practice of dyeing fabrics from acidified solutions. Children use these coloring markers to write and color on a wide variety of substrates, in particular on porous surfaces such as paper. Most suitable for use in coloring compositions are, in general, those acid dyes having good chrome, color intensity, and water solubility. One drawback of acid dyes, however, is that generally they stain the skin and few are completely washable from children's clothing. Acid dyes also tend to stain many household surfaces. By using a polymeric bonded acid dye in an ink composition according to the invention, permanent staining of the acid dye can substantially be reduced. A further more preferred embodiment of the invention relates to a waterbome ink, wherein the polymeric dye is a colorant chemically bonded to the water-soluble polymer via at least one covalent bond. Covalent bonding can be applied to colorants with reactive groups capable to react with functional groups on the water- soluble polymer. Colorants with such reactive groups are also known as reactive dyes. The advantage of a covalently bonded colorant is that it forms an integral part of the water-soluble polymer to which it is linked and therefore there is less chance of detachement from the water-soluble polymer. Bonding of a colorant to the water- soluble polymer via a covalent bond can be advantageously applied to enhance the solubility both in water as well in organic solvents. By using a polymeric bonded reactive dye in combination in an ink composition according to the invention, permanent staining of the reactive dye can substantially be reduced.

Examples of suitable reactive groups for forming covalent bonds are, for example, but not limited thereto, halotriazine rings, for example fluorotriazine rings or chlorotriazine rings, dihalo- or halosulfonyl-pyrimidine rings, dihaloquinoxaline groups, dihalopyrazone groups, dihalophthalazine groups, halobenzothiazole groups, mono-(m-carboxypyridinium)-triazine groups, amino epoxide groups, substituted sulfone groups, for example a vinylsulfone group or sulfatoethyl sulfone group, carboxylic acid groups or carboxylic acid chlorides, phenolic groups, haloacetylamide groups and sulfatopropionamides. Preferably the reactive group is a fluorotriazine ring or chlorotriazine ring, a vinylsulfone group, a carboxylic acid group or carboxylic acid chloride. The advantage is that these groups easily react with a hydroxy group or a carboxylic acid group to give a covalent bond. A fluorotriazine ring or chlorotriazine ring can react, for example, with a hydroxy group to form an ether bond between the colorant and the water-soluble polymer. A vinylsulfone group can react with, for example, a hydroxy group to form an ether bond. A carboxylic acid group or carboxylic acid chloride can react with, for example a hydroxy group to form an ester bond.

The water-soluble polymer may, for example, be a water-soluble hyperbranched polyester or a water-soluble hyperbranched polyesteramide. Preferably, a water-soluble hyperbranched polyesteramide is used. The advantage is that dyes bound to a water-soluble hyperbranched polyesteramide allow the formation of ink compositions with a very low level of permanent staining of the human skin.

The polymeric dye may also be a polymeric colorant possessing a certain amount of polyoxyalkylene groups (such as ethylene oxide, propylene oxide, butylene oxide, glycidol and the like). Preferably, these colorants have all ethylene oxide groups, as these are more water soluble and thus more fugitive than longer chain groups, although combinations of ethylene oxide and any of the others may be utilized as well. The term polyoxyalkylene is intended to encompass any pendant group, which includes at least two alkyleneoxy moieties. Preferably, each polyoxyalkylene group 2 to 50, more preferably 2 to 10 alkyleneoxy moieties.

The inventive waterbome ink may also comprise standard components, such as liquid carriers, including, and not limited to, water, water miscible solvents such as lower alcohols, (ethanol, methanol, and isopropanol), glycol ethers, polyethylene glycol, phenols, and the like. The ink of this invention may comprise non- aqueous solvents (with no water present) as long as the colorant easily disperses within the solvent. Other components that may be comprised in the waterbome ink include humectants (such as glycerin and alkylene glycols, for example ethylene glycol, propylene glycol, butylenes glycol), film-forming polymers (such as starch), water soluble resins (such as polyvinylpyrrolidine and polyvinylactetate), surfactants (such as nonionic surfactants, [such as ethoxylated dodecanol], anionic surfactants [such as alkyl phosphates] and cationic surfactants [such as quaternary ammonium salts]), preservatives, defoamers, pH regulators as well as other components. These materials and their functions are well known, and their mention here is by way of illustration only. Generally, any effective amount of the additive may be used as long as the coloring composition, and the stability thereof, are suitable for use in the desired end product.

Typically, the inventive waterbome ink comprises water as the liquid carrier. The liquid carrier may be present in an amount varying within a wide range. The maximum amount of liquid carrier is the amount which results in a stable composition and which is capable of forming a mark having the minimum acceptable visibility on a substrate. The minimum amount of liquid carrier is that necessary to form a stable solution of the components of the coloring composition in the waterbome ink and to provide an ink composition that can be freely dispensed from a selected ink delivery system. Preferably, the waterbome ink comprises a water-soluble hyperbranched polymer. This has the advantage that the composition may comprise a higher amount of the copolymer or a copolymer with a higher molecular weight without raising the viscosity of a washable waterbome ink composition up to unacceptable levels. Typically, the inventive washable waterbome ink comprises a) 50 - 99 weight % of a liquid carrier and optionally other soluble components, b) 0.5 - 40 (preferably 1 - 30) weight % of a copolymer or a salt thereof of an aliphatic carboxylic acid-functional aliphatic monomer and an non-functional aliphatic monomer in a weight ratio between carboxylic acid-functional aliphatic monomer and non-functional aliphatic monomer, such that it allows water solubility and simultaneously imparts a good dye-blocking effect, c) 0.5 - 40 (preferably 1 - 30) weight % of at least one colorant, d) 0 -25 (preferably 0-10) weight % of at least one other component, wherein the weight % are relative to the total weight of the ink and the sum of a) + b) + c) + d) is 100%.

The invention also relates to the use of a copolymer or a salt thereof of an aliphatic carboxylic acid-functional aliphatic monomer and an non-functional aliphatic monomer in a weight ratio between carboxylic acid-functional aliphatic monomer and non-functional aliphatic monomer, such that it allows water solubility and simultaneously imparts a good dye blocking effect, as dye-blocker in a washable waterbome ink.

The invention also relates to an ink delivery system, such as marker pens, writing implements, felt-tip pens, spray-pattern indicators and other colorant transfer devices containing a waterbome ink according to the invention. The invention will now be elucidated with reference to the following examples, without being limited thereto.

Materials:

Olefin copolymer A: Poly(MA-co-O)Na: poly(maleic acid-co-olefin) sodium salt , 25 % (M/M) solution in water; (ex Sigma-Aldrich Chemie BV, Zwijndrecht, The Netherlands). Acid copolymer B: Poly(acrylic acid-co-maleic acid); 50 % (M/M) solution in water,

(ex Sigma-Aldrich Chemie BV, Zwijndrecht, The Netherlands). Styrene copolymer C: Milliguard® AW: A low molecular weight poly(styrene-co-maleic acid) sodium salt, 20 % (M/M) solution in water, (ex Milliken &

Company, Spartanburg, SC, U.S.A.). Colorants: Palmer Colorants Black, Blue, FL-Red, Orange, Scarlet and

Magenta (ex Milliken & Company, Spartanburg, SC, U.S.A.) Reactive Dyes: Cibacron Blue P-3R (C.I. 621526) and Cibacron Red P-B (C.I. 18208) (ex Ciba Geigy, Groot Bijgaarden, Belgium)

Acid Dyes: Acid Red 1 , Acid Red 18, Acid Red 52, Acid Yellow 17 (C.I.

42650), FD&C Yellow 6, Acid Blue 7, Acid Black 2 (ex

Chemische Fabriek Triade, Naaldwijk, The Netherlands) Polymeric Dyes: Concentrates of polymer-bonded dyes, based on the Reactive Dyes and Acid Dyes mentioned above and a hyperbranched polymer, were prepared as described below Fluorescent Dye: Acid Yellow 73: water-soluble fluoresceine (ex

Chemische Fabriek Triade, Naaldwijk, The Netherlands)

Synthesis of hyperbranched polymer P.

A double-walled glass reactor was charged with 528 g of molten diisopropanolamine having a temperature of 40°C. 331 g of succinic anhydride was added under stirring and the reaction mixture was heated to 180°C. After leaving the reaction mixture at this temperature under stirring for three hours, the pressure in the reactor was lowered to 2 mPA. After a total reaction time of 6.5 hours at 180°C, the polymer obtained was cooled and obtained as a solid. The acid value of the polymer was 0.8 mg KOH/g resin.

Synthesis of concentrate of polymer bonded Reactive Blue 49 (Concentrate Blue P-3R) 66 g of Cibacron Blue P-3R was mixed with 200 g of hyperbranched polymer D and heated to 150 °C for 2 hours. During the reaction a covalent bond was formed between a hydroxyl group of polymer A and the chlorotriazine ring of the dye. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C. Synthesis of concentrate of polymer bonded Reactive Red 24 (Concentrate Red P-B)

66 g of Cibacron Red P-B was mixed with 200 g of hyperbranched polymer D and heated to 150 °C for 2 hours. During the reaction a covalent bond was formed between a hydroxy group of polymer A and the chlorotriazine ring of the dye. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Yellow 17 (Concentrate Yellow 17) 5 g of Acid Yellow 17 was mixed with 30 g of hyperbranched polymer

D and heated to 150°C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Red 1 (Concentrate Red 1) 12,5 g of Acid Red 1 was mixed with 25 g of hyperbranched polymer D and heated to 150°C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Red 18 (Concentrate Red 18) 7,5 g of Acid Red 18 was mixed with 30 g of hyperbranched polymer D and heated to 150°C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Red 52 (Concentrate Red 52) 12,5 g of Acid Red 52 was mixed with 30 g of hyperbranched polymer

D and heated to 150°C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C. Svnthesis of concentrate of polymer bonded FD&C Yellow 6 (Concentrate Yellow 6)

7,5 g of FD&C Yellow 6 was mixed with 30 g of hyperbranched polymer D and heated to 150°C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Blue 7 (Concentrate Blue 7)

12,5 g of Acid Blue 7 was mixed with 30 g of hyperbranched polymer D and heated to 150 °C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Synthesis of concentrate of polymer bonded Acid Black 2 (Concentrate Black 2)

12,5 g of Acid Black 2 was mixed with 30 g of hyperbranched polymer D and heated to 150 °C for 2 hours. Upon cooling the reaction mixture solidified. 10 g of the reaction mixture was dissolved in 15 g of water at 70 °C.

Testing of skin staining

The skin stain test was done as follows. To start with, the person doing the test, further called subject, washed his/her hands with hand soap and warm water to remove substantially all residual traces of grease, oil and dirt and dried his/her hands thoroughly first with a towel and then by air-drying. The test composition was then applied using a cotton wadding bud to the palm of the subject's hand. One mark, approximately 1 inch long and 1/4 of an inch wide was made for each composition. More colorant composition was applied through repeated drawings on the same line, when necessary, until each composition exhibited the same color intensity. The marks were allowed to dry for fifteen minutes and then rinsed under cold water to remove excess color. After the water rinse step, the remaining stains (if any) were evaluated empirically on a scale of one to five. Then the subject washed his/her hands with soap and cold water for 30 seconds and rinsed and dried his/her hands with a paper towel. After this soap wash step, the remaining stains (if any) were evaluated again empirically on a scale of one to five both after the water rinse of Step 4 and the soap wash of Step 5. The rating scale was as follows: Rating Comment

0 No visible stain

1 Very light stain 2 Light stain

3 Moderate stain

4 Heavy stain

5 No color removed

Preparation of inks

In the following examples all materials are used as received or as obtained from the synthesis except for Olefin copolymer A and Acid copolymer B, which were diluted with water to a solid content of 20 % (M/M) in water.

Examples l-VI

Based on the Palmer Colorants and the Olefin copolymer A, 6 waterbome inks were prepared having the following composition, showing between brackets the relative weight amounts: colorant (2), Olefin copolymer A (2), glycerin (0,6) and water (1,4).

Comparative Experiments A-F

Based on the Palmer Colorants and Styrene copolymer C, 6 waterbome inks were prepared with a composition similar to those of Example l-VI: colorant (2), Styrene copolymer C (2), glycerin (0,6) and water (2); (the values between brackets show the relative weight amounts).

Comparative Experiments G-L

6 Waterbome inks similar to those of Example l-VI were prepared with the Acid copolymer B and the 6 Palmer Colorants. The compositions of these inks were as follows (the values between brackets show the relative weight amounts): colorant (2), Acid copolymer B (2), glycerin (0,6) and water (1,4).

Comparative Experiments M-R. Blank experiments were done by preparing waterbome inks, with the same colorants without the addition of a dye blocker, having the following composition, colorant (2), glycerin (0,6) and water (3,4); (the values between brackets show the relative weight amounts).

Each composition was then tested for skin staining. The results of the skin rinsability and washability test of the inventive Examples and the Comparative Experiments after rinsing and washing are listed in Table I.

Table I. Stain test results for Examples l-VI and Comparative Experiments A-R

Examples VII-VIII and Comparative Experiments S-X

Based on the Red Concentrate and the Blue concentrate of the polymer bond dyes, waterbome inks were prepared with the Olefin copolymer A (Examples VII-VIII), the Styrene copolymer C (Comparative Experiments S-T) and the Acid copolymer B (Comparative Experiments U-V) and blank experiments without the addition of dye blocker (Comparative Experiments W-X). The compositions are shown in Table II. Table II. Composition of Inks according Examples VII-VIII and Comparative Experiments S-X (numbers indicate relative weight of the respective components)

Each composition was then tested for skin staining. The results of the skin rinsability and washability of the inventive Examples and the Comparative Experiments after rinsing and washing are listed in Table III.

Table III. Stain test results for Examples VII-VIII and Comparative Experiments S-X

Examples IX-XV and Comparative Experiments Y-NN

Based on the Red Concentrate and the Blue concentrate of the polymer bond dyes, waterbome inks were prepared with the Olefin copolymer A(Examples VII-VIII), the Styrene copolymer C (Comparative Experiments S-T) and the Acid copolymer B (Comparative Experiments U-V) and blank experiments without the addition of dye blocker (Comparative Experiments W-X). The compositions are shown in Table II.

Table IV. Composition of Inks according Examples IX-XV and Comparative Experiments Y-SS (numbers indicate relative weight of the respective components)

Each composition was then tested for skin staining. The results of the skin rinsability and washability of the inventive Examples and the Comparative Experiments after rinsing and washing are listed in Table V.

Table V. Stain test results for Examples IX-XV and Comparative Experiments Y-SS

The results in Tables I, III and V show that the define Copolymer A used in the Examples has very good dye-blocking properties, which are as least as good as the Styrene copolymer C and in several cases even better. The results are also much better than those obtained with the control and in the major part of the cases also better than those obtained with the Acid copolymer B.

Example XVI An amount of Olefin Copolymer A solution (25% in water) was weighted and diluted with water to form a 20% solution. An amount, corresponding with 1% of the 20% solution, of Fluorescent Dye (Acid yellow 73) was weighted, added to and dissolved into the solution to form an intensely colored 1 % solution of Fluorescent Dye in a 20% Olefin Copolymer A solution. 5 ml of this solution was pipetted in a 50 ml flask and filled to the mark with water. After shaking, 5 ml of the diluted solution was pipetted in a 50 ml flask and filled to the mark with water. After shaking, 5 ml of this double diluted solution was pipetted in a 50 ml flask and filled to the mark with water. Thus a 1000 times diluted solution of Fluorescent Dye and Olefin Copolymer A was obtained. A 1 cm cuvette was filled with the solution for recording an UV-VIS absorption spectrum.

Comparative Experiment TT An amount of Fluorescent Dye (Acid yellow 73) was weighted and dissolved in Styrene copolymer C in such extent to form a 1% solution of Fluorescent Dye in 20 % Styrene copolymer C solution. This solution was diluted, analogously to Example XVI, in 3 steps to a 1000 times diluted solution of Fluorescent Dye and Styrene Copolymer B in water. A 1 cm cuvette was filled with the solution for recording an UV-VIS absorption spectrum.

Comparative Experiment UU

An amount of Fluorescent Dye (Acid yellow 73) was weighted and dissolved in water, and diluted in such extent to form a 1% solution of Fluorescent Dye in water. This solution was diluted, analogously to Example XVI, in 3 steps to a 1000 times diluted solution of Fluorescent Dye in water. A 1 cm cuvette was filled with the solution for recording an UV-VIS absorption spectrum.

UV-VIS analysis UV-VIS absorption spectra of the 1000 times diluted solutions of

Example XVI and Comparative Experiments TT and UU, were recorded with a UV-VIS spectrometer Instrument Model Lambda (range 280-580 nm; slit width 2 nm, scan speed 60 nm/min) with water as a reference. Before the recording of the spectra a test run was made with water versus water in 1 cm cuvettes under the same conditions. The wavelength at maximum absorption and relative values for the maximum absorption are reported in next table VI.

The absorption spectra had very similar shapes, with a maximum absorption with experimental error at the same wave length, indication that the polymers present in the solution did not effect the shape of absorption of the fluorescent dye. The relative values for the absorption differ significantly, the lower value for Comparative Experiment TT relative to Comparative Experiment UU indicating a weakening effect of the Styrene copolymer C on the color intensity of the fluorescent dye, while the higher value for Example XVI relative to Comparative Experiment UU indicating a enhancing effect of the Olefin Copolymer A on the color intensity of the fluorescent dye. Table VI: UV-VIS results for Example XVI and Comparative Experiments TT and UU

Claims

1. Washable waterbome ink comprising a polymer having acid functional groups characterized in that the polymer is a copolymer or a salt thereof of an aliphatic carboxylic acid-functional aliphatic monomer and an non-functional aliphatic monomer in a weight ratio between the carboxylic acid-functional aliphatic monomer and the non-functional aliphatic monomer, such that the copolymer has a carboxyl equivalent weight of between 60 g/mol and 600 g/mol.

2. Washable waterbome ink according to claim 1 , wherein the copolymer comprises 10-99 weight % of the carboxylic acid-functional aliphatic monomer and 90-1 weight % of the non-functional aliphatic monomer, and the weight % are relative to the total weight of the copolymer.

3. Washable waterbome ink according to claim 1 or 2, wherein the copolymer has a carboxyl equivalent weight of between 80 g/mol and 400 g/mol.

4. Washable waterbome ink according to any of the claims 1 to 3, wherein the copolymer has a weight average molecular weight is between 600 g/mol and 50.000 g/mol.

5. Washable waterbome ink according to any of the claims 1 to 4, wherein carboxylic acid-functional aliphatic monomer is chosen from the group consisting of acrylic acid, methacrylic acid, maleic acid and the anhydride thereof, fumaric acid, itaconic acid and the anhydride thereof, and mixtures thereof.

6. Washable waterbome ink according to any of the claims 1 to 5, wherein the non-functional aliphatic monomer is an ester of an aliphatic alcohol with a carboxyl acid-functional monomer or an α-olefin.

7. Washable waterbome ink according to any of the claims 1 to 6, wherein the copolymer is a copolymer of maleic acid, or the anhydride thereof, and a α- olefin.

8. Washable waterbome ink according to any of the claims 1 to 7, wherein the washable waterbome ink comprises a neutralizing agent chosen from the group consisting of ammonia, an amine and a metal hydroxide chosen from lithium hydroxide, sodium hydroxide and potassium hydroxide.

9. Washable waterbome ink according to any of claims 1 to 8, comprising at least one colorant.

10. Washable waterbome ink according to claim 9, wherein the at least one colorant is a polymeric dye consisting of a colorant bonded to a water-soluble polymer.

11. Waterbome ink according to any of claims 1-10, wherein the waterbome ink comprises a hyperbranched polymer.

12. Use of a copolymer according to any of claims 1-7 as a dye blocker in a waterbome ink.

13. Ink delivery system, such as a marker pen, a writing implement, a felt-tip pen, a spray-pattern indicator or another colorant transfer device, containing a washable waterbome ink according to any of claims 1-11.