Core-shell polymeric materials

FIELD OF THE INVENTION

The present invention relates to particulate materials having a core or core-shell structure. The present invention further relates to aqueous dispersions and inkjet ink compositions comprising such materials, and methods for making particulate materials, dispersions, and ink compositions.

CONTEXT

Ink compositions generally contain water-soluble dyes or water-insoluble pigments. While some dye-based inks are suitable for their intended uses, dyes have several disadvantages when used in inkjet ink compositions. For example, water soluble dyes can dissolve and diffuse when exposed to moisture or water. In addition, dye images may bleed or bleed on contact with felt tip markers or on being rubbed or touched by fingers. Dyes can also exhibit poor light stability when exposed to visible light, ultraviolet light, or sunlight.

Pigments can also be used as colorants in ink compositions to overcome certain drawbacks of colorants. However, pigments may not adhere sufficiently to substrates and may also be deficient in durability, for example, as indicated by drag in a highlight smear test. Accordingly, there remains a need to develop ink compositions comprising such colorants.

ABSTRACT

One embodiment relates to a particulate core-shell material, comprising, a core comprising a polyurethane; and a shell comprising a polyacrylate, wherein the shell covers the core.

Preferably, the core: shell weight ratio is in the range of 4: 1 to 1: 1.

Preferably, the core has a Tg (glass transition temperature) less than or equal to 50 ° C.

<td>Advantageously, ° C.</td><td>the</td><td>core</td><td>at</td><td>a</td><td>Tg</td><td>lower</td><td>or</td><td>equal</td>

<td>Advantageously, ° C.</td><td>the</td><td>core</td><td>at</td><td>a</td><td>Tg</td><td>lower</td><td>or</td><td>equal</td>

<td>Advantageously,</td><td>the</td><td>core</td><td>at</td><td>a</td><td>Tg</td><td>lower</td><td>or</td><td>equal</td>

at 20 ° C.

<td></td><td>Advantageously,</td><td>the envelope has</td><td>a</td><td>Tg</td><td>at</td><td>less</td>

<td> 20</td><td>° C.</td><td></td><td></td><td></td><td></td><td></td>

<td> 25</td><td>Advantageously, ° C.</td><td>the envelope has</td><td>a</td><td>Tg</td><td>at</td><td>less</td>

<td> 30</td><td>Advantageously, ° C.</td><td>the envelope has</td><td>a</td><td>Tg</td><td>at</td><td>less</td>

<td>is</td><td colspan="2">In one aspect of the invention, greater than the Tg of the nucleus.</td><td>the Tg</td><td>of</td><td colspan="2">The envelope</td>

<td colspan="2">Advantageously, at least 10 ° C at</td><td colspan="2">a Tg of the envelope Tg of the nucleus.</td><td>is</td><td colspan="2">superior</td>

<td> 30</td><td colspan="3">Advantageously, the Tg of the envelope ° C and the Tg of the core is less than 30</td><td>is ° C.</td><td>at</td><td>less</td>

<td> 25</td><td colspan="3">Advantageously, the Tg of the envelope ° C and the Tg of the core is less than 25</td><td>is ° C.</td><td>at</td><td>less</td>

In one aspect of the invention, the core comprises a crosslinked polyurethane.

In another aspect of the invention, the core comprises a linear polyurethane.

In another further aspect of the invention, the core comprises a branched polyurethane.

In another further aspect of the invention, the core comprises a grafted polyurethane.

In another 10 the envelope comprises

In another the envelope includes

In another the envelope includes

In another, the envelope comprises a further aspect of the invention, a crosslinked polyacrylate.

further aspect of the invention, a linear polyacrylate.

further aspect of the invention, a branched polyacrylate.

further aspect of the invention, a graft polyacrylate.

Advantageously, the core is covalently linked to the envelope.

Advantageously, the nucleus is covalently linked to the shell via a linker selected from urethane, urea, ester, and amide linkers.

Advantageously, the core-shell material comprises the reaction product of a vinyl terminated polyurethane and ethylenically unsaturated monomers.

Another embodiment relates to a particulate core-shell material comprising the reaction product of a vinyl terminated polyurethane and ethylenically unsaturated monomers.

In one aspect of the invention, the vinyl terminates the polyurethane via a linker selected from urethane, urea, ester, amide, and -CN- linkers.

In another aspect of the invention, the vinyl terminated polyurethane is the reaction product of an NCO terminated polyurethane prepolymer and ethylenically unsaturated monomers containing hydroxyl, and the vinyl terminates the polyurethane via a urethane binder.

In another further aspect of the invention, the vinyl terminated polyurethane is the reaction product of an NCO terminated polyurethane prepolymer and ethylenically unsaturated amino-containing monomers, and the vinyl terminates the polyurethane via a urea linker.

In a further aspect of the invention, the vinyl terminated polyurethane is the reaction product of a prepolymer of hydroxylated polyurethane and acid-containing unsaturated monomers, and the vinyl terminates the polyurethane via an ester linker.

ethylenic termination

In a further aspect of the invention, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and the vinyl terminates the polyurethane via an amide linker.

In a further aspect of the invention, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing epoxy, and the vinyl terminates the polyurethane via a CN- linker.

In another further aspect of the invention, the vinyl terminated polyurethane has the formula:

^ Polyurethane

R1 wherein R1 is selected from hydrogen, alkyls and aryls, and X comprises a linker selected from urethane, urea, ester and amide linkers.

In a further aspect of the invention, the vinyl-terminated polyurethane is the reaction product of an NCO-terminated polyurethane prepolymer and ethylenically unsaturated hydroxyl-containing monomers, and X comprises a urethane linker.

In a further aspect of the invention, the vinyl-terminated polyurethane is the reaction product of an NCO-terminated polyurethane prepolymer and ethylenically unsaturated amino-containing monomers, and X comprises a urea linker.

In a further aspect of the invention, the vinyl terminated polyurethane is the reaction product of a hydroxyl terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and X comprises an ester linker.

In another further aspect of the invention, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and X comprises an amide linker.

In a further aspect of the invention, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing epoxy, and X comprises a -CN- linker.

In another further aspect of the invention, X has the formula:

o wherein M is bonded to polyurethane;

in which M and P are independently selected from

NH, O, and CH₂ ; x and y are independently selected from 0 or 1; and L has the formula:

<img file="FR3003259B1_D0001.tif" />

R₂ R₃ FU in which R₂, R3, and R₄ are independently selected from hydrogen, alkyls, aryls, and hydroxyl; B is selected from NH and 0; and m, n, o, p, y are independently selected from 0 to 10.

In another further aspect of the invention, the ethylenically unsaturated monomers comprise a mixture of hydrophobic and hydrophilic monomers.

In another further aspect of the invention, the ethylenically unsaturated monomers are hydrophilic.

Advantageously, the ethylenically unsaturated monomers contain acidic groups and salts thereof.

In another further aspect of the invention, the ethylenically unsaturated monomers are selected from acrylics and acrylates.

Advantageously, the ethylenically unsaturated monomers comprise at least one first monomer chosen from acrylics and acrylates, and at least one second monomer chosen from acrylamides, vinyl-containing monomers, styrenes and butadiene.

In one aspect of the invention, the core of the material comprises a polyurethane.

In another further aspect of the invention, the shell of the material comprises the polymerization reaction product of the ethylenically unsaturated monomers with the vinyl terminated polyurethane.

In another further aspect of the invention, the shell of the material comprises a polyacrylate.

In another further aspect of the invention, the reaction product is capable of self-assembly in aqueous solution to form the particulate core-shell material.

Another embodiment relates to a method of making a particulate core-shell material, comprising:

reacting a vinyl terminated polyurethane with ethylenically unsaturated monomers.

In one aspect of the invention, the reaction is carried out in the presence of a radical initiator.

In another aspect of the invention, the reaction is carried out by solution polymerization or emulsion polymerization.

In another further aspect of the invention, the reaction is carried out in an organic solvent to form a solution containing the reaction product, and the method further comprises exposing the reaction product to an aqueous solution so as to cause the reaction product. 'self-assembly of the core-shell material.

Another embodiment relates to a particular core-shell material having the formula:

Polymer A-X-Polymer B wherein Polymer A comprises a polyurethane positioned in the core and Polymer B comprises a polyacrylate positioned in the shell, and wherein X is selected from urethane, urea, ester, and amide linkers.

Another embodiment relates to a composition comprising at least one pigment and the particulate materials previously described.

Another embodiment relates to an aqueous dispersion comprising at least one pigment and the particulate materials previously described.

Another embodiment relates to an inkjet ink composition comprising at least one pigment and the particulate material described herein.

DETAILED DESCRIPTION

Presently described are particulate materials having a core-shell structure. One embodiment relates to a particulate core-shell material comprising:

a core comprising a polyurethane; and a shell comprising a polyacrylate, wherein the shell covers the core.

In one embodiment, the particulate materials are provided in aqueous dispersions and inkjet ink compositions. For example, polymeric materials having film-forming properties have been added to an ink containing pigment for inkjet compositions to impart durability to the printed product since the film contributes to the adhesion of the pigment particles to the substrate. . However, the film-forming ability is balanced with ink-jetability reliability, which is achieved by avoiding adhesion between the particles and the printhead nozzle. It has been found that the core-shell particles can achieve this balance in that the core can function as a film former while the polyacrylate shell can impart inkjet capability.

In the present context, the term "polyurethane" denotes a polymer containing organic moieties assembled by urethane linkers (eg, -NH-C (O) -. O). The urethane linker typically results from a condensation reaction between polyisocyanates (eg, diisocyanates) and polyols (eg, diols and triols). The polyurethane can further include other types of linkers, such as urea linkers (eg, - NH-C (Ο) -NH-), in addition to urethane linkers.

In one embodiment, the polyisocyanates comprise two or more isocyanate groups bonded to organic groups, such as organic groups selected from C1-Cio alkylene, C3-C20A cycloalkylenes, C3-C20 heterocycloalkylenes, arylenes, heteroarylenes, and a combination thereof, each of which may be substituted with C1-C10 alkyls or aryls.

Examples of diisocyanate monomers include toluene 2,4-diisocyanate (2,4-TDI), 2,6-diisocyanate

<td rowspan="2">toluene (2.6- diisocyanate diisocyanate</td><td rowspan="2">TDI), of of</td><td colspan="2">hexamethylene diisocyanate (HDI),</td>

<td>4,4'-methylenediphenyl 2,4'-methylenediphenyl</td><td>(4,4'-MDI), (2,4'-MDI),</td>

<td>15 diisocyanate</td><td>of</td><td>2,2'-methylenediphenyl</td><td>(2,2'-MDI),</td>

<td>diisocyanate</td><td>of</td><td>methylene-bis (4-cyclohexyl)</td><td>(HDMI),</td>

diisocyanate diisocyanate (m-TMXDI), and isophorone m-tetramethylxylene (IPDI).

In one embodiment, the polyols include two or more -OH units, for example, diols and triols, bonded to organic groups, which can be small molecules or polymers such as polyesterpolyols, polyether polyols, and polycarbonatepolyols. Examples of organic groups include those selected from C1-C10 alkylene, C-cycloalkylenes₃-VS₂o, C3-C20 heterocycloalkylenes, arylenes, heteroarylenes, polyethers (eg, polypropylene glycols, poly (tetramethylene oxides), polycaprolactones), polyesters (eg, poly (butylene adipate) and a poly (hexamethylene adipate)), polycarbonates (for example, polycarbonates prepared from 2-butyl-2ethylpropyldiol, such as those of the OXYMER® series of products marketed by the Perstorp Group, or polycarbonates prepared from a mixture of 1,5pentanediol and 1,6-hexanediol, such as those of the DURANOL® series of products marketed by Asahi Kasei ίο

Chemical Corporation), polyacetals, polythioethers, polyesteramides, polyacrylates, polyolefins, polyalkylsiloxanes, and mixtures thereof.

Examples of polyols include polypropylene glycols, polyethylene / polypropylene glycols, poly (tetramethylene oxide) diols, poly (butylene adipate) glycols, poly (hexamethylene adipate) diol, polycarbonatediols prepared from. substituted or unsubstituted C1-C10 alkylenediols (e.g. 1,6-hexanediol, 1,5-pentanediol,

2-butyl-2-ethylpropyldiol), polycarbonates containing hydroxyl groups include products obtained by reaction of diols (such as propanediol, butanediol, hexanediol, ethylene glycol, triethylene glycol, or tetraethylene glycol) with phosgene, diarylcarbonates (such as diphenyl carbonate) or with cyclic carbonates (such as ethylene carbonate or propylene). Polycarbonates can also be obtained by reaction between a polyesterdiol and phosgene, diarylcarbonates, or cyclic carbonates.

In one embodiment, the polyol is a polymeric polyol having number average molecular weight in the range of 200 g / mol to 6000 g / mol, for example, 400 g / mol to 6000 g / mol, or 700 g / mol to 2000 g / mol. Such molecular weights can be determined by terminal group analysis.

Polyurethanes can be prepared by methods known in the art, for example, polycondensation reactions. The preparation typically implements multi-step synthesis methods. For example, an NCO terminated prepolymer can be prepared by reacting a polyol monomer (eg, diol) with a diisocyanate monomer. The reaction can take place in the absence of a solvent or in a water-miscible organic solvent (eg, acetone or N-methylpyrrolidone) which does not react with the isocyanate. The reaction can optionally be carried out at an elevated temperature (eg, at least about 50 ° C) and / or in the presence of a catalyst (eg, dibutyltin dilaurate). Reaction times can range from a few minutes to several hours, and may depend on factors such as reaction temperature, monomer concentrations, monomer reactivity, and the presence or absence of a catalyst. The molar amounts of the monomers can be based on the A / B ratio, where A is the molar amount of isocyanate groups and B is the molar amount of the hydroxyl groups of all diol monomers (or diamine monomers, if applicable). The A / B ratio can be at least about 1, for example, in the range of 1 to 2.

After reacting the polyol with the polyisocyanate, an NCO terminated polyurethane prepolymer can be formed. The A / B ratio can also be less than about 1, for example, in the range of 0.5 to 1. After the reaction, an OH-terminated polyurethane prepolymer (or NH2 terminated if diamine monomers are used) can. to be trained.

In one embodiment, vinyl groups can be linked to the polyurethane by subsequent reaction of the polyurethane prepolymer using methods known in the art. Such vinyl groups can be derived from monomers containing organic groups, including -COOH, -OH and -NH2, which can react with isocyanate, hydroxyl, or amino groups. Exemplary monomers include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, hydroxyethyl acrylate, and hydroxyethyl methacrylate. For example, hydroxyethyl methacrylate can react with NCO terminated polyurethane prepolymers to form vinyl terminated polyurethane under conditions similar to the preparation of polyurethane. In one embodiment, vinyl groups can be linked to the polyurethane via a linker selected from urethane, urea, ester, and amide linkers. In another embodiment, vinyl groups can be linked at either end of a polyurethane chain and / or at both ends of a polyurethane chain.

In one embodiment, the polyacrylate shell results from the polymerization of monomers chosen from acrylic acids and acrylates. Examples of monomers for the preparation of polyacrylates include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid; polymerizable monomers containing a sulfonic acid such as 3-sulfopropyl acrylate; polymerizable monomers containing amino such as methacrylate

N, N-dimethylaminoethyl, N, Ndiethylaminoethyl methacrylate; alkyl acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, 2ethylhexyl acrylate, lauryl acrylate, stearyl acrylate ; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and stearyl methacrylate; reactive polymerizable monomers such as glycidyl acrylate, glycidyl methacrylate, and acrolein; polymerizable hydroxyl-containing monomers such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate; polyfunctional polymerizable monomers such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,635 hexanediol dimethacrylate, polyethylene dimethacrylate, polyethylene dimethacrylate polyethylene glycol, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate and pentaerythritol trimethacrylate; polymerizable monomers containing a cationic group such as N, N-dimethylaminoethyl acrylate, methacrylate

N, N-dimethylaminoethyl, N, Ndiethylaminoethyl acrylate, and N, Ndiethylaminoethyl methacrylate.

Other monomers can be copolymerized with acrylic acid and / or acrylate monomers, comprising polymerizable monomers containing an amide group such as acrylamide, methacrylamide, N-methylolacrylamide, N-methylol methacrylamide, di-N-methylolacrylamide, di-N-methylolmethacrylamide, vinyacetamide; such as vinylpyrrolidone, and vinyl acetate; des and methylstyrene;

monomers containing vinyl vinylpyridine, vinyltoluene, styrenes such as styrene

Acrylonitrile; and butadiene

The polyurethanes forming the core and / or the polyacrylates forming the shell can be linear, branched, crosslinked (bond between polymers), or grafted (bond to macromolecules or substrates), using methods known in the art.

In one embodiment, the polyurethane is crosslinked. Examples of crosslinking agents include polyamines, polyols, and polyisocyanates having three or more functional groups capable of crosslinking reactions, for example, from 3 to 5 functional groups.

In one embodiment, the shell covers or otherwise coats or encapsulates the core, eg, the entire core. The covering, coating or encapsulant may or may not be in direct contact with the core. In one embodiment, an intermediate layer can be positioned between the shell and the core, for example, to facilitate adhesion or help produce a desired particle size. In another embodiment, the core is covalently linked to the shell.

In one embodiment, the particulate core-shell material is the reaction product of a vinyl-terminated polyurethane with monomers selected from acrylics and acrylates. The vinyl can terminate the polyurethane via a linker selected from urethane, urea, ester, amide, and -CN- linkers. In one embodiment, the vinyl terminated polyurethane is the reaction product of an NCO terminated polyurethane prepolymer and ethylenically unsaturated monomers containing hydroxyl, and the vinyl terminates the polyurethane via a urethane linker. In another embodiment, the vinyl terminated polyurethane is the reaction product of an NCO terminated polyurethane prepolymer and ethylenically unsaturated monomers containing amino, and the vinyl terminates the polyurethane via a urea linker. In another embodiment, the vinyl terminated polyurethane is the reaction product of a hydroxyl terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and the vinyl terminates the polyurethane via an ester linker. In another embodiment, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and the vinyl terminates the polyurethane via an amide linker. In another further embodiment, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing epoxy, and the vinyl terminates the polyurethane via a -CN- linker.

In one embodiment, the reaction between the polyurethane and the ethylenically unsaturated monomers involves a hydrophobic polyurethane and a hydrophilic ethylenically unsaturated monomer in an organic solvent to generate a soluble polymer. Exemplary organic solvents include alcohols. In one embodiment, the reaction product is capable of self-assembly in aqueous solution to form the particulate core-shell material. For example, after adding water, the polymer self-assembles so as to form the hydrophilic part in the form of a shell and the hydrophobic part as a core.

In one embodiment, the vinyl terminated polyurethane has the formula:

'^5%^ 5 '^' 'polyurethane

R 1 in which R 1 is selected from hydrogen, alkyls and aryls, and X comprises a linker selected from urethane, urea, ester and amide linkers. Alkyls are straight or branched chain saturated groups of 1 to

20 carbon atoms, for example, C1-C12 alkyls,

C1-C10, or C1-C6. Aryls are mono-, bi-, or other carbocyclic ring aromatic systems, for example, C1-C20 aryls, or C1-C12 aryls. Alkyls and aryls can be unsubstituted or substituted, for example, by alkyls, aryls, hydroxy, halide, alkoxy, amino, amido, carboxy, cyano, ester, ether, halogen, nitro, sulfate, sulfonate, sulfonyl, phosphate, phosphonate, and thio. In one embodiment, RI is chosen from hydrogen and C-alkyls_x-C6.

In one embodiment, the vinyl-terminated polyurethane is the reaction product of an NCO-terminated polyurethane prepolymer and ethylenically unsaturated monomers containing hydroxyl, and X comprises a urethane linker. In another embodiment, the vinyl terminated polyurethane is the reaction product of an NCO terminated polyurethane prepolymer and ethylenically unsaturated amino-containing monomers, and X comprises a urea linker. In another embodiment, the vinyl terminated polyurethane is the reaction product of a hydroxyl terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and X comprises an ester linker. In another embodiment, the vinyl-terminated polyurethane is the reaction product of an amino-terminated polyurethane prepolymer and ethylenically unsaturated monomers containing an acid, and X comprises a friend linker of. In another further embodiment, the vinyl terminated polyurethane is the reaction product of an amino terminated polyurethane prepolymer and ethylenically unsaturated monomers containing epoxy, and X comprises a -CN- linker.

In one embodiment, X has the formula:

/ © A¹'^- □

wherein M is bonded to the polyurethane;

wherein M and P are independently selected from NH, 0, and CH₂ ; x and y are independently selected from 0 or 1; and L has the formula:

(¾ rî &lt;

and in which R₂, R3, and R₄ are independently selected from hydrogen, alkyls, aryls, and hydroxyl; B is selected from NH and 0; and m, n, o, p, y are independently selected from 0 to 10.

One embodiment relates to a method of making a particulate core-shell material, comprising:

reacting a vinyl terminated polyurethane with ethylenically unsaturated monomers.

Vinyl-terminated polyurethane may have the structure

Polyurethane

Ri r

where Ri and X are as defined above.

In one embodiment, the reaction involves the polymerization reaction of the ethylenically unsaturated monomers in the presence of the vinyl terminated polyurethane. The reaction can be carried out by solution polymerization or emulsion polymerization. These polymerization processes are well documented in the literature and known to those skilled in the art. In one embodiment, the reaction is carried out in the presence of a radical initiator.

In one embodiment, the reaction results in a polyurethane-polyacrylate polymer. This polymer can further be combined with an aqueous solution base to produce the particulate core-shell material by self-assembly of polyurethane-polyacrylate polymers.

In one embodiment, the reaction is carried out in an organic solvent to form a solution containing the reaction product, and the method further comprises exposing the reaction product to an aqueous solution so as to cause self-assembly. of the core-shell material. In one embodiment, the aqueous solution comprises water, eg, 100% water, or a mixture of water and a miscible solvent (eg, at least 50% water). In one embodiment, the amount of aqueous solution added is sufficient to cause the self-assembled core-shell material to precipitate out of solution. The core-shell material can be purified and isolated by methods known in the art.

In one embodiment, the particulate material has the formula:

Polymer A-X-Polymer B wherein Polymer A comprises positioned in the core and Polyacrylate polymer positioned in the shell, embodiment, X is selected from ester, and amide linkers.

a polyurethane

B includes a

In a mode of urethane, urea,

In one embodiment, the polyurethane core has a weight average molecular weight of at least about 2000 g / mol (eg, at least about 5000 g / mol, at least about 10,000 g / mol). In another embodiment, the polyurethane core has a weight average molecular weight in the range of 2000 g / mol to 150,000 g / mol, for example, 2000 g / mol to 100,000 g / mol, or from 2000 g / mol to. 50,000 g / mol). In another embodiment, the polyurethane core has a weight average molecular weight in the range of about 10,000 g / mol to about 50,000 g / mol.

Without wishing to be bound by theory, it is believed that an ink composition having the claimed molecular weight exhibits a suitable balance of properties for increased durability (e.g., as indicated by drag in a highlighter smudge test) compared to the inkjet capacity.

Tg (i.e., glass transition temperature) can be determined by methods known in the art, such as measurement of viscoelasticity or thermal analysis. Alternatively, a theoretical value of T_g for the polymer material can be calculated based on the T_ghomopolymers of the polymerizable monomer. For example, the T_g of a copolymer obtained by copolymerization of three monomers, monomer I, monomer II, and monomer III, can be calculated based on equation (1) below:

100 / (T_g of the copolymer) = (% by weight of I / T monomer_g of homopolymer I) + (% by weight of monomer II / T_g of homopolymer II) + (% by weight of monomer III / T_g homopolymer III) (1)

In one embodiment, the core has a Tg less than or equal to 50 ° C, for example, a Tg less than or equal to 40 ° C, less than or equal to 30 ° C, a Tg less than or equal to 25 ° C, or a Tg less than or equal to 20 ° C. In one embodiment, the envelope has a Tg of at least 20 ° C, for example, a Tg of at least 25 ° C, or a Tg of at least 30 ° C. In one embodiment, a Tg of the shell is greater than a Tg of the core.

In one embodiment, the shell is "hard" relative to the "soft" core. Without wishing to be bound by any theory, it is believed that an ink formulation comprising a hard shell / soft core structure has both durability and inkjet capability. A hard shell produces the right inkjet properties, while the soft core enables film formation and provides durability to the resulting printed image. In one embodiment, the Tg of the shell is at least 30 ° C and the Tg of the core is less than 30 ° C. In another further embodiment, the Tg of the shell is at least 25 ° C and the Tg of the core is less than 25 ° C. In one embodiment, the Tg of the envelope is at least 10 ° C above the Tg of the core.

In one embodiment, the particulate shell core material has a minimum film-forming temperature (i.e., MFFT) of 25 ° C or less. (Generally, if the minimum film-forming temperature exceeds 25 ° C, a film cannot be formed under ambient conditions (for example, at room temperature) when an ink containing such a particulate material is applied to a medium. 'recording. One or more of gloss, clarity and uniformity of gloss may not be sufficiently obtained in some cases.) The resulting film serves to fix the dye components in the ink composition to the surface of a dye support. 'recording. Accordingly, the disclosed particulate materials can produce an image having good smear resistance. The minimum film-forming temperature of the polymer particles can be controlled by varying the types and composition ratio of monomers used in the core and shell regions and the weight average molecular weight of the polymer particles. The minimum film formation temperature of the polymer particles can be measured according to the test method of ISO 2115.

In one embodiment, the particulate materials have a volume average particle size in the range of 30 nm to 500 nm, for example, 50 nm to 400 nm, or 100 nm to 400 nm. Without wishing to be bound by any theory, it is believed that these size ranges balance the need for optimal inkjet (maximum size 400 or 500nm) with optical density (minimum size 30, 50, or 100 nm). After printing, larger core-shell particles can prevent pigment from absorbing into the paper substrate, thereby improving OD and / or durability.

In one embodiment, a core: shell weight ratio is in the range of 10: 1 to 1:10, for example, 5: 1 to 1: 5, or 4: 1 to 1: 1. Without wishing to be bound by any theory, it is believed that an ink composition having polymer particles with the core: shell weight ratio of the invention balances suitable properties for increased durability (e.g., as shown by little or no drag in a highlight smudge test) compared to inkjet capability.

Compositions, dispersions, and ink compositions for inkjet

Another embodiment relates to compositions comprising a colorant (eg, at least one pigment) and the particulate materials described herein.

The dye can be chosen from dyes and pigments. In one embodiment, the colorant is a colorant, such as conventional colorants including food colors, FD&amp;C colorants, acidic colors, direct dyes, reactive dyes, phthalocyanine sulfonic acid derivatives, including phthalocyanine derivatives. copper, sodium salts, ammonium salts, potassium salts, lithium salts, and the like. Combinations of dyes can also be used to form different hues. Examples of acidic dyes include, but are not limited to, acid red 18, acid red 27, acid red 52, acid red 249, acid red 289, acid blue 9, acid yellow 23, acid yellow 17, acid yellow 23, and acid black 52. Examples of basic dyes include, but are not limited to, basic red 1, basic blue 3, and basic yellow 13. Examples of direct dyes include, but are not limited to, direct red.

227, direct blue 86, direct blue 199, direct yellow

86, direct yellow 132, direct yellow 4, direct yellow 50, direct yellow 132, direct yellow 104, direct black 170, direct black 22, direct blue 199, direct black 19, and black direct 168. Examples of reactive dyes include, but are not limited to, reactive red 180, reactive red 31, reactive red 29, reactive red 23, reactive red 120, reactive blue 49, reactive blue 25, reactive yellow 37, reactive black 31, reactive black 8, reactive green 19, and reactive orange 84. Other types of dyes can also be used, including, for example, yellow 104 and magenta, 37 7.

In addition to the colorant (dyes or pigments), the inkjet ink compositions of the present invention may further incorporate additional colorants to modify the color balance and adjust optical density. Such dyes include food colors, FD&amp;C dyes, acid dyes, direct dyes, reactive dyes, derivatives of phthalocyaninesulfonic acids, including copper phthalocyanine derivatives, sodium salts, ammonium salts, potassium salts, and lithium salts.

In one embodiment, the colorant is selected from pigments, which are solid materials, generally in the form of a particle or in a readily particulate form, such as a cake. The pigment can be any type of pigment conventionally used by those skilled in the art, such as black pigments and other colored pigments including blue, black, brown, cyan, green, white, purple, magenta, red pigments, orange, or yellow. Mixtures of different pigments can also be used. Representative examples of black pigments include various carbon blacks (pigment black 7) such as tunnel blacks, furnace blacks, gas blacks, and lamp blacks, and include, for example, commercial carbon blacks. under the names Regai®, Black Pearls®, Elftex®, Monarch®, Mogul®, and Vulcan®, the carbon blacks marketed by Cabot Corporation (such as Black Pearls® 2000, Black Pearls® 1400, Black Pearls® 1300, Black Pearls® 1100, Black Pearls® 1000, Black Pearls® 900, Black Pearls® 880, Black Pearls® 800, Black Pearls® 700, Black Pearls® 570, Black Pearls® L, Elftex® 8, Monarch® 1400, Monarch® 1300, Monarch® 1100 , Monarch® 1000, Monarch® 900, Monarch® 880, Monarch® 800, Monarch® 700, Regai® 660, Mogul® L, Regai® 330, Regai® 400, Vulcan® P). Carbon blacks marketed by other suppliers can be used. Suitable classes of colored pigments include, for example, anthraquinones, phthalocyanine blues, phthalocyanine greens, disazos, monoazoids, pyranthrones, perylenes,. heterocyclic yolks, quinaeridones, quinolonoquinolones, and (thio) indigoids. Such pigments are marketed as a powder or cake from a variety of sources including, BASF Corporation, Engelhard Corporation, Sun Chemical Corporation, Clariant, and Dianippon Ink and Chemicals (DIC). Examples of other suitable color pigments are described in the Color Index, 3^th edition (The Society of Dyers and Colourists, 1982). In one embodiment, the pigment is a cyan pigment, such as pigment blue 15 or pigment blue 60, a magenta pigment, such as pigment red 122, pigment red 177, pigment red 185, pigment red 202 , or pigment violet 19, a yellow pigment, such as pigment yellow 74, pigment yellow 128, pigment yellow 139, pigment yellow 155, pigment yellow 180, pigment yellow 185, pigment yellow

218, pigment yellow 220, or pigment yellow 221, an orange pigment, such as pigment orange 168, a green pigment, such as pigment green 7 or pigment green 36, or a black pigment, such as black. carbon.

In one embodiment, the dye comprises a pigment and a dye to modify the color balance and adjust optical density.

In one embodiment, the pigment may be a self-dispersed pigment with a hydrophilic group or a polymer bonded to the surface of the pigment particle, a pigment dispersed in a polymer, and a microencapsulated pigment.

In one embodiment, the pigment is a self-dispersing pigment, for example selected from oxidized carbon black and pigments to which at least one organic group is bonded. Such self-dispersed pigments can be prepared by modification of any of the pigments described herein.

In one embodiment, the self-dispersed pigment is an oxidized carbon black. In one embodiment, "oxidized carbon blacks" are carbon black pigments generally having a pH &lt;7.0 which include ionic or ionizable surface bonded groups such as one or more of alcohols (phenols , naphthols), lactones, carbonyls, carboxyls (eg, carboxylic acids), anhydrides, ethers, and quinones. The degree of oxidation of carbon black can determine the surface concentration of these groups. In one embodiment, the oxidized carbon black is obtained by oxidizing an unmodified carbon black, for example, pigments selected from tunnel blacks, furnace blacks, gas blacks, and carbon blacks. lamp. Examples of unmodified carbon blacks include those marketed by Cabot Corporation such as Regai®, Black Pearls®, Elftex®, Monarch®, Mogul®, and Vulcan®, such as Black Pearls® 1100, Black Pearls® 900,

Black Pearls® 880, Black Pearls® 800, Black Pearls® 700,

Black Pearls® 570, Elftex® 8, Monarch® 900, Monarch® 880,

Monarch® 800, Monarch® 700, Regai® 660, and Regai® 330. Examples of oxidizing agents for carbon blacks include oxygen gas, ozone, peroxides such as hydrogen peroxide, persulfates such as sodium and potassium persulfate, hypohalites such as 1 sodium hypochlorite, nitric acid, and oxidants containing transition metals such as permanganate salts, osmium tetroxide, chromium oxides, ceric ammonium nitrates, and mixtures thereof (for example, mixtures of gaseous oxidants such as oxygen and ozone).

In another embodiment, the oxidized carbon black is obtained from commercial sources, such as Black Pearls® 1400, Black Pearls® 1300, Black Pearls® 1000, Black Pearls® L, Monarch® 1000, Mogul® L, and Regai® 400, marketed by Cabot Corporation.

In one embodiment, the pigment comprises at least one linked organic group where a "linked" organic group can be distinguished from an adsorbed group as a Soxhlet extraction for several hours (e.g., at least 4, 6, 8, 12, or 24 hours) does not remove the bound group from the pigment. In another embodiment, the organic group is bonded to the pigment if the organic group cannot be removed after repeated washing with a solvent or a mixture of solvents which can dissolve the starting organic treatment material but cannot disperse the solvent. pigment treated. In another further embodiment, "linked" refers to a bond such as a covalent bond, for example, a pigment bound or covalently bonded to a nucleophilic or organic group.

In one embodiment, the pigment is a carbon black to which at least one organic group is bonded. In one embodiment, the at least one organic group comprises a group selected from carboxylic acids, sulfonic acids, phosphonic acids, hydroxyls, amines, and esters, amides, and salts thereof. . In another embodiment, the at least one organic group comprises the formula - [R (A)] ~, in which:

R is bonded to carbon black and is selected from arylene, heteroarylene, and alkylene, and

A is selected from carboxylic acids, sulfonic acids, phosphonic acids, hydroxyls, amines, and esters, amides, and salts thereof.

Arylene, heteroarylene, and alkylene can be unsubstituted or substituted. Examples of¹ arylenes include phenylene, naphthylene, and biphenylene, and examples of ¹ heteroarylenes include phenylene, naphthylene, and biphenylene having a cyclic carbon substituted with one or more oxygen or nitrogen atoms. In one embodiment, the arylene is C5-C20 arylene. Heteroarylenes can be arylene as defined herein in which one or more ring carbon atoms are replaced by a heteroatom, for example, N, O, and S. The heteroatom can be bonded to other groups in addition to be a cyclic atom. Alkylenes can be branched or unbranched. The alkylene can be C1-C12 alkylene such as methylene, ethylene, propylene, or butylene.

In one embodiment, the linked organic group comprises at least one ionic group, an ionizable group, or mixtures of an ionic group and an ionizable group. An ionic group can be anionic or cationic and can be associated with a counterion of the opposite charge comprising inorganic or organic counterions, such as Na⁺, K⁺, Li⁺, NH4⁺, NR'4⁺, acetate, NO3, SO4^2-, R'SO3,

ROSO3 ', OH^-, or Cl ”, where R¹ represents hydrogen or an organic group, such as a substituted or unsubstituted aryl or alkyl group. An ionizable group is a group which is capable of forming an ionic group in the medium of use. Anionic groups are negatively charged ionic groups which can be generated from groups having ionizable substituents which can form anions (anionizable groups), such as acidic substituents. Cationic groups are positively charged ionic groups which can be generated from ionizable substituents which can form cations (cationizable groups), such as deep amines. Specific examples of anionic groups include -COO^-'-SO3 ”' -OSO3^-'-HPO3-; -OPO3^-2, or -PO3^-2, and specific examples of an anionizable group may include -COOH, -SO3H, -PO3H2, -R'SH, or -R'OH, where R 'represents hydrogen or an organic group, such as an aryl or alkyl group substituted or unsubstituted. In addition, specific examples of cationic or cationizable groups include alkyl- or arylamines, which can be protonated in acidic medium to form ammonium -NR'2H groups.⁺, where R 'represents an organic group, such as substituted or unsubstituted aryl or alkyl groups. Organic ionic groups include those described in U.S. Patent No. 5,698,016.

For example, the linked group can be an organic group such as a benzene carboxylic acid group (group -C₆H₄-COOH), a benzenedicarboxylic acid group, a benzenetricarboxylic acid group, a benzenesulfonic acid group (a -C6H4-SO3H group), or salts thereof. In one embodiment, surface modification to introduce ionic or ionizable groups on the surface of a pigment, such as chlorination and sulfonylation, can also be used.

In one embodiment, the linked organic group comprises a polymer. In one embodiment, the polymer comprises at least one nonionic group. Examples include alkylene oxide groups of about 1 to about 12 carbons and polyols, such as a group

-CH2-CH2-O-, a -CH group (CH₃) -CH₂-O-, a -CH group₂CH (CH₃) -O-, a -CH2CH2CH2-O- group, or combinations of. these. These nonionic groups can also comprise at least one ionic or ionizable group as described presently.

In one embodiment, the polymer has a low acid number. In one embodiment, the polymer may be a polymer containing an acid group having an acid number of less than or equal to about 200, for example less than or equal to about 150, less than or equal to about 110, or less than or equal to about 100. In another embodiment, the acid number of the polymer is greater than or equal to about 30. Therefore, the polymer may be an acid group containing polymer having an acid number of from about 30 to about 200, for example from about 30 to about 110, from about 110 to about 150, or from about 150. at about 200.

In one embodiment, the carbon black is modified with at least one organic group via diazonium treatment as detailed, for example, in the following patents: US Patents. No. 5,554,739; 5,630,868; 5,672,198; 5,707,432; 5,851,280; 5,885,335; 5,895,522;

<td> 5</td><td> 900</td><td> 029</td><td></td><td> 5 922</td><td> 118 ; 6 042 643</td><td> ; 6 534 569</td><td>r</td><td colspan="2"> 6 398 858</td>

<td>and</td><td> 6</td><td> 494</td><td> 94 3</td><td colspan="3">(high shear conditions)</td><td> 6</td><td> 372</td><td> 820 ;</td>

<td> 6</td><td> 368</td><td> 239</td><td> /</td><td> 6 350</td><td> 519 ; 6 337 358 ;</td><td> 6 103 380 ;</td><td> 7</td><td> 173</td><td> 078 ;</td>

<td> 7</td><td> 056</td><td> 962</td><td>r</td><td> 6 942</td><td> 724 ; 6 929 889 ;</td><td> 6 911 073 ;</td><td> 6</td><td> 478</td><td> 8 63 ;</td>

<td> 5 6</td><td> 472</td><td> 471</td><td>r</td><td>and WO</td><td>2011/143533. In</td><td>a mode of</td><td colspan="3">production,</td>

the binding is carried out via a diazonium reaction where the at least one organic group has a diazonium salt substituent. In another embodiment, the direct bond can be formed using the diazonium and stable free radical methods described, for example, in US Patent Nos. 6,068,688; 6,337,358;

368 239; 6,551,393; 6,852,158, which use the reaction of at least one radical with at least one particle, where a radical is generated by the interaction of at least one transition metal compound with at least one organohalide compound in the presence of one or more particles capable of radical capture, and the like. In one embodiment, the organic group is derived from amino functionalized aromatic compounds, such as 420 aminobenzylamine (4-ABA), 3-aminobenzylamine (3-ABA), 2-aminobenzylamine (2- ABA), 2-aminophenylethylamine, 4-aminophenyl- (2-sulfatoethyl) -sulfone, (APSES), paminobenzoic acid (PABA), 4-aminophthalic acid (4-APA), and 5-aminobenzene-1 acid , 2,3-tricarboxylic.

Another embodiment relates to a dispersion comprising at least one pigment and the particulate materials described herein. In one embodiment, the at least one pigment and the particulate materials are dispersed in a liquid vehicle, eg, an aqueous vehicle. In one embodiment, the aqueous solution contains more than 50% by weight of water and can be, for example, water or mixtures of water with water-miscible solvents such as alcohols. In one embodiment, the amount of pigment present in the dispersion can vary but is typically in an amount in the range of 0.1% to 30%, for example, 1% to 25%, 1% to 20%. , from 3% to 20%, from 3% to 15%, based on the total weight of the dispersion.

Another embodiment relates to an inkjet ink composition comprising at least one pigment and the particulate materials described herein. In one embodiment, the ink compositions are aqueous compositions and include a colorant, optional solvents, and additives such as surfactants, biocides, and the core polymeric shell material.

In one embodiment, the inkjet ink composition can be formulated to provide an amount of colorant such that the final amount in the inkjet ink composition is effective to produce the image quality. desired (eg, optical density) without deleteriously affecting the performance of the inkjet ink. In one embodiment, the colorant (eg, pigment) is present in an amount in the range of 1% to 10% by weight, based on the total weight of the composition, eg, an amount in the range of 2% to 10% by weight, from 3% to 10% by weight, from 2% to 7% by weight, or from 3% to 7% by weight, relative to the total weight of the composition.

Dispersants (surfactants and / or dispersants) can be added to further increase the colloidal stability of the composition or to modify the interaction of the ink with the printing substrate, such as the printing paper, or with the ink printhead. Various anionic, cationic and nonionic dispersing agents can be used in conjunction with the ink composition of the present invention, and these can be used neat or as an aqueous solution.

Representative examples of dispersants or anionic surfactants include, but are not limited to, higher fatty acid salts, higher alkyldicarboxylates, sulfuric acid ester salts of higher alcohols, (higher alkyl) sulfonates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, naphthalenesulfonates (Na, K,

Li, Ca, etc.), formalin polycondensates, condensates between higher fatty acids and amino acids, dialkylsulfosuccinic acid ester salts, alkylsulfosuccinates, naphthenates, a 1 ky Lé t her ca rboxy la tes, acylated peptides, a10 ο 1 e f ine su 1 f ona tes, N-acrylmethyltaurine, alkylethersulfonates, secondary higher alcohol ethoxysulfates, polyoxyethylene alkylphenylethersulfates, monoglycylsulfates, alkyl etherphosphates and alkylphosphates, alkylphosphonates and bisphosphonates, including hydroxy or amine derivatives. For example, polymers and copolymers of styrenesulfonate salts, unsubstituted and substituted naphthalenesulfonate salts (eg, alkyl or alkoxy substituted naphthalene derivatives), aldehyde derivatives (such as non-substituted alkylaldehyde derivatives). substituted compounds including formaldehyde, acetaldehyde, propylaldehyde, and the like), salts of maleic acid, and mixtures thereof can be used as anionic dispersant builders. Salts include, for example, Na⁺, Li⁺, K⁺, Cs⁺, Rb⁺, and substituted and unsubstituted ammonium cations. Representative examples of cationic surfactants include aliphatic amines, quaternary ammonium salts, sulfonium salts, phosphonium salts and the like.

Representative examples of dispersants or nonionic surfactants which can be used in inkjet inks of the present invention include fluorinated derivatives, silicone derivatives, acrylic acid copolymers, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether. polyoxyethylene, a secondary alcohol ether of polyoxyethylene, a styrol ether of polyoxyethylene, ethoxylated acetylenic diols, polyoxyethylene lanolin derivatives, ethylene oxide derivatives of alkylphenolformol condensates, block polymers of polyoxyethylene polyoxypropylene, fatty acid esters of polyoxyethylene-a lkylether compounds of p ο 1 y oxypr op y 1 enepolyoxyethylene, fatty acid esters ethylene glycol polyethylene oxide) of condensation type, fatty acid monoglycerides, polyglycerol fatty acid esters, propylene glycol fatty acid esters, sugarcane fatty acid esters, fatty acid alkanol amides, polyoxyethylene fatty acid amides and polyoxyethylene alkylamide oxides. For example, ethoxylated monoalkyl- or dialkylphenols can be used. These nonionic surfactants or dispersants can be used alone or in combination with the anionic and cationic dispersants mentioned above.

The dispersing agents can also be a natural polymer dispersant or a synthetic polymer dispersant. Specific examples of natural polymeric dispersants include proteins such as glue, gelatin, casein and albumin; natural rubbers such as gum arabic and gum tragacanth; glucosides such as saponin; alginic acid, and alginic acid derivatives such as propylene glycol alginate, triethanolamine alginate, and ammonium alginate; and cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose and

Ethyl hydroxycellulose. Specific examples of polymeric dispersants, including synthetic polymeric dispersants, include polyvinyl alcohols, pο 1 yviny1pyrrο1idones, acrylic or methacrylic resins (often referred to as "(meth) acrylic") such as poly ((meth) acrylic acid), copolymers of acrylic acid- (meth) acrylonitrile, copolymers of potassium (meth) acrylate- (meth) acrylonitrile, (meth) acrylate ester vinyl acetate copolymers and (meth) acrylate ester (meth) acrylic acid copolymers; styrene-acrylic or methacrylic resins such as styrene-(meth) acrylic acid copolymers, styrene-(meth) acrylic acid-(meth) acrylate ester copolymers, styrene-a-methylstyrene-aeide copolymers (meth) acrylic, styrene ea-methylstyrene-(meth) acrylic acid-(meth) acrylate ester copolymers; styrene-maleic acid copolymers; copolymers of maleic styrenehydride, copolymers of vinylnaphthalene acrylic acid or methacrylic acid; vinylnaphthalene-maleic aci copolymers; and vinyl acetate copolymers such as vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid-vinylethylene copolymers, vinyl acetate maleate ester copolymers, vinyl acetate copolymer. vinyl-crotonic acid and a vinyl acetate-acrylic acid copolymer; and salts thereof.

Humectants and water-soluble organic compounds can also be added to the inkjet ink composition of the present invention, in particular for the purpose of preventing clogging of the nozzle as well as to impart paper penetrating properties ( penetrating), improved drying (drying accelerators), and anti-tightening. Specific examples of humectants and other water soluble compounds which can be used include low molecular weight glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and dipropylene glycol; diols containing from about 2 to about 40 carbon atoms, such as 1, 3-pentanediol, 1,4-butanediol, 1,535 pentanediol, 1,4-pentanediol, 1,6-hexanediol, 1 , 5hexanediol, 2,6-hexanediol, neopentylglycol (2,2dimethyl-1,3-propanediol), 1,3-propanediol, 1,43003259 butanediol, 1,5-pentanediol, 1,6-hexanediol , the

1,2,6-hexanetriol, poly (ethylene-co-propylene) glycol, and the like, as well as their reaction products with alkylene oxides, including ethylene oxides / including ethylene oxide and propylene oxide; triol derivatives containing from about 3 to about 40 carbon atoms, including glycerin, trimethylolpropane, 1,3,5-pentanetriol, 1,2,6-hexanetriol, and the like as well as their reaction products with alkylene oxides, including ethylene oxide, propylene oxide, and mixtures thereof; neopentylglycol, (2,2-dimethyl-1,3-propanediol), and the like, as well as their reaction products with alkylene oxides, comprising ethylene oxide and propylene oxide in a ratio molar desirable for forming materials with a wide range of molecular weights; thiodiglycol; pentaerythritol and lower alcohols such as ethanol, propanol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol, 2-propyn-l-ol (propargyl alcohol), 2-buten-1-ol, 3-buten-2-o1, 3-butyn-2-ol, and cyclopropanol; amides such as dimethylformaldehyde and dimethylacetamide; ketones or ketoalcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; cellosolves such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, triethylene glycol monomethyl (or mο ηoethyl) ether; carbitols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; lactams such as 2-pyrrolidone, N-methyl-2-pyrrolidone and ε-caprolactam; urea and urea derivatives; internal salts such as betaine, and the like; thio (sulfur) derivatives of the materials mentioned above including 1-butanethiol; tbutanethiol, 1-methyl-1-propanethiol, 2-methyl-13003259 propanethiol; 2-methyl-2-propanethiol; thiocyclopropanol, thioethylene glycol, thiodiethylene glycol, trithio- or dithiodi é thy 1 è neg 1 yc ο 1, and the like; hydroxyamide derivatives, including acetylethanolamine,

Acetylpropanolamine, propylcarboxyethanolamine, propylcarboxypropanolamine, and the like; reaction products of the materials mentioned above with alkylene oxides; and mixtures thereof. Additional examples include saccharides such as maltitol, sorbitol, gluconolactone, and maltose; polyols such as trimethylolpropane and trimethylolethane; N-methyl-2-pyrrolidone; 1,3dimethyl-2-imidazolidinone; sulfoxide derivatives containing from about 2 to about 40 carbon atoms, including dialkylsulfides (symmetrical and asymmetric sulfoxides) such as dimethylsulfoxide, methylethylsulfoxide, akylphenylsulfoxides, and the like; and sulfone derivatives (symmetrical and asymmetric sulfones) containing from about 2 to about 40 carbon atoms, such as dimethylsulfone, methylethylsulfone, sulfolane (tetramethylenesulfone, a cyclic sulfone), dialkylsulfones, alkylphenylsulfones, dimethylsulfone, methyl ethylsulfone, diethylsulfone,

Ethylpropylsulfone, methylphenylsulfolane, methylsulfolane, dimethylsulfolane, and the like. Such materials can be used singly or in combination.

Biocides and / or fungicides can also be added to the inkjet ink composition of the present invention. Biocides are important in preventing bacterial growth since bacteria are often larger than ink nozzles and can cause clogging and other printing problems. Examples of useful biocides include, but are not limited to, benzoate or sorbate salts, and isothiazolinones.

In one embodiment, the inkjet ink composition comprises a co-solvent. In one embodiment, the co-solvent is soluble or miscible in water at concentrations of at least 10% by weight and is also chemically stable under aqueous hydrolysis conditions (e.g., reaction with water under heat aging conditions, including, for example, hydrolysis of esters and lactones). In one embodiment, the co-solvent has a dielectric constant lower than that of water, such as a dielectric constant in the range of about 10 to about 78 at 20 ° C. Examples of suitable co-solvents include low molecular weight glycols (such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, methyl ethyl ether. ethyleneg 1 ycο 1, monomethyl ether. or triethylene glycol monoethyl, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and tetraethylene glycol monobutyl ether); alcohols ____ (such as ethanol, propanol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol, 2propyn-1-ol (propargyl alcohol ), 2-buten-1-ol,

3-buten-2-ol, 3-butyn-2-ol, and cyclopropanol); diols containing from about 2 to about 40 carbon atoms (such as 1,3-pentanediol, 1,4-butanediol, 1,5pentanediol, 1,4-pentanediol, 1,6-hexanediol, 1,5hexanediol, 2,6-hexanediol, neopentylglycol (2,2dimethyl-1,3-propanediol), 1,3-propanediol, 1,4butanediol, 1,5-pentanediol, 1,6-hexanediol , the

1,2,6-hexanetriol, and poly (ethylene-co-propylene) glycol, as well as their reaction products with alkylene oxides, including ethylene oxides, including ethylene oxide and propylene oxide); triols containing from about 3 to about 40 carbon atoms (such as glycerin (glycerol), trimethylolethane, t rimethylolpropane, 1, 3,5-pentanetriol, 1,2,65 hexanetriol, and the like as well as reaction products thereof with alkylene oxides, including ethylene oxide, propylene oxide, and mixtures thereof); polyols (such as pentaerythritol); amides (such as dimethylformaldehyde and dimethylacetamide); ketones or ketoalcohols (such as acetone and diacetone alcohol); ethers (such as tetrahydrofuran and dioxane); lactams (such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and εcaprolactam); ureas or urea derivatives (such as di- (2-hydroxyethyl) -5,5, -dimethyl-hydantoin (dantacol) and 1,3-dimethyl-2-imidazolidinone); internal salts (such as betaine); and hydroxyamide derivatives (such as acetylethanolamine, acetylpropanolamine, propylcarboxyethanolamine, and propylcarboxypropanolamine, as well as their reaction products with alkylene oxides). Additional examples include saccharides (such as maltitol, sorbitol, gluconolactone, and maltose); sulfoxide derivatives (symmetrical and asymmetric) containing from about 2 to about 40 carbon atoms (such as dimethylsulfoxide, methylethylsulfoxide, and alkylphenylsulfoxides); and sulfone derivatives (symmetrical and asymmetric) containing from about 2 to about 40 carbon atoms (such as dimethylsulfone, methylethylsulfone, sulfolane (tetramethylenesulfone, a cyclic sulfone), dia 1kyl sulfones, alkylphenylsulfones, dimethylsulfone , methyl ethylsulfone, diethylsulfone,

Ethylpropylsulfone, methylphenylsulfone, methylsulfolane, and dimethylsulfolane). These co-solvents can be used alone or in combination.

The amount of the co-solvent can vary depending on various factors, including the properties of the solvent (solubility and / or dielectric constant), the type of pigment modified, and the desired performance of the resulting inkjet ink composition. In particular, the optional co-solvent can be used in amounts less than or equal to about 40% by weight based on the total weight of the inkjet ink composition, comprising an amount less than or equal to about 30 % and less than or equal to approximately 20%. In addition, when used, the amount of the optional co-solvent is greater than or equal to about 2% by weight based on the total weight of the inkjet ink composition, comprising an amount greater than or equal to about 5% and greater than or equal to about 10% by weight.

EXAMPLES

Abbreviations

Abbreviations and commercial sources:

_________________ · __________ IPDI -Isophorone diisocyanate _ ___ • HEMA = 2-Hydroxyethyl methacrylate • MMA = Methyl methacrylate • MAA = Methacrylic acid • AIBN = Azobisisobutyronitrile • HQ = Hydroquinone • EtOAc = Ethyl acetate • IPAH = = 2-Propanol • THF = Tetrahydrofuran • KOH = Potassium hydroxide • PEG600 = a polyethylene glycol with a molecular weight of 600 g / mol • TMP = Trimethylolpropane • SURFYNOL 465 = nonionic surfactant from Air Products • Fomrez 55-56 = polyester diol having a hydroxyl number of approximately 57 mg KOH / g (from Chemtura)

Example 1: HEMA I terminated polyurethane

To a 1 liter cylindrical reactor, equipped with a temperature controller, a stirrer, a condenser, and a nitrogen gas line, are added 150.4 g of Fomrez 55-56. After heating the contents to 80 ° C under nitrogen, a clear solution is thus obtained. 22.2 g of IPDI are then added to the mixture dropwise using a dropping funnel or plastic syringe. The reaction temperature is then increased to about 95 ° C and held for 4 hours. Then 150 ml of is added slowly under After the addition is complete, the reaction mixture is kept at about 80 ° C for 2.5 hours. At the end, after adding 5.38 ml of EtOH, the reaction continues for an additional hour at 80 ° C. This batch of HEMA-terminated polyurethane polymer solution is cooled to room temperature under nitrogen for the next step. These polyurethane polymers function as the core of the core-shell polymer particles.

EtOAc and 2.8 ml of shaking HEMA, respectively.

Example 2: polyurethane-acrylate polymer I

<td>AT</td><td>the</td><td>solution</td><td>polymer</td><td>from polyurethane to</td>

<td colspan="2">termination</td><td>HEMA I</td><td>of example 1,</td><td>150 ml of IPA is</td>

<td>added.</td><td>The</td><td>solution</td><td>of mixing</td><td>polymer is then</td>

<td>heated</td><td>at</td><td>about</td><td colspan="2">80 ° C. At the same time, a mixture of</td>

ml of styrene, 9.2 ml of MMA, 59.5 ml of MAA, 3.13 g of AIBN, and 100 ml of IPA is prepared and subjected to nitrogen bubbling. This mixture is then added to the polymer solution dropwise using a 5-dropper funnel over about 2 hours at 80 ° C. Once the addition is complete, the reaction continues for an additional 3 hours. At the end, 300 ml of THF are added and the PU-acrylate polymer solution is cooled to room temperature. These acrylic-styrene acrylate polymers function as the shell of the core-shell polymer particles.

Example 3: Core-Shell Polymer Particles I (CSPP-I)

With stirring, 50 g of the polyurethane-acrylate polymer solution I of Example 2 is diluted with 181 ml of THF, followed by the slow addition of 8.5 g of 20% by weight aqueous KOH solution. A few minutes later, this mixture is added to about 195 g of water with rapid stirring. A milky solution is obtained without any visible solid precipitate. The solvent is removed in vacuo and the solution is then filtered through 1 µm filters. A final solution containing polymer particles having a core-shell structure is obtained: 8.8% solid, particle size = 361 nm, AN = 150, core / shell weight ratio = 2/1. These dispersions remain stable at room temperature for several months. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Example 4: HEMA terminated polyurethane polymer.

II

To a 1 liter cylindrical reactor, equipped with a temperature controller, a stirrer, a condenser, and a nitrogen gas line, are added 150.4 g of Fomrez 55-56. After heating the contents to 80 ° C under nitrogen, a clear solution is thus obtained. 22.2 g of IPDI are then added to the mixture dropwise using a dropping funnel or plastic syringe. The reaction temperature is then increased to about 95 ° C and held for 4 hours. Then, 300 ml of EtOAc, 11.2 ml of HEMA, and 0.102 g of HQ are added slowly with stirring, respectively. After the addition is complete, the reaction mixture is held at about 80 ° C for about 4 hours. At the end, after adding 5.38 ml of EtOH, the reaction continues for an additional hour at 80 ° C. This batch of HEMA-terminated polyurethane polymer solution is cooled to room temperature under nitrogen for the next step. These polyurethane polymers function as the core of the core-shell polymer particles.

Example 5: polyurethane-acrylate polymer II

Half of the HEMA II terminated polyurethane polymer solution of Example 4 is used for the preparation of polyurethane-acrylate II polymer. After adding 50 ml of IPA, the polymer mixture solution is then heated to about 75 ° C. At the same time, a mixture of 9.0 ml of styrene, 26.3 ml of MMA, 8.11 ml of MAA, 1.384 g of AIBN, and 30 ml of IPA is prepared and bubbled with nitrogen. This mixture is then added to the polymer solution dropwise using a dropping funnel over about 1.5 hours at 75 ° C. Once the addition is complete, the reaction continues for an additional 4 hours. At the end, the polyurethane-acrylate polymer solution is cooled to room temperature. Such acrylic-styrene-acrylate polymers function as the shell of the core-shell polymer particles.

Example 6: Core-shell polymer particles II (CSPP-II)

With stirring, 50 g of the polyurethane-acrylate polymer solution of Example 5 are diluted with

275 ml of THF, followed by the slow addition of 9.5 g of 10% by weight aqueous KOH solution. A few minutes later, this mixture is added to about 270 g of water with rapid stirring. A milky solution is obtained without visible solid precipitate. The solvent is removed in vacuo and the solution is then filtered through 1 µm filters. A final solution containing polymer particles having a core-shell structure is obtained: 9.0% solid, particle size = 294 nm, AN = 43, core / shell weight ratio = 2/1. These dispersions remain stable at room temperature for several months. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

0 Example 7: HEMA terminated polyurethane polymer

III

To a 1 liter cylindrical reactor, equipped with a temperature controller, a stirrer, a condenser, and a nitrogen gas line, are added 130.3 g of Fomrez

55-56. After heating the contents to 80 ° C under nitrogen, a clear solution is thus obtained. 22.2 g of IPDI are then added to the mixture dropwise using a dropping funnel or plastic syringe. The reaction temperature is then increased to approximately

95 ° C and held for 4 hours. Then 250 ml of

EtOAc, 15.64 ml of HEMA, and 0.142 g of HQ are added slowly with stirring, respectively. After the addition is complete, the reaction mixture is held at about 80 ° C for about 4 hours. At the end, after adding 11.8 ml of n-butanol, the reaction continues for an additional hour at 80 ° C. This batch of HEMA-terminated polyurethane polymer solution is cooled to room temperature under nitrogen for the next step. Such polyurethane polymers function as core polymers of core-shell polymer particles.

Example 8: Polyurethane-acrylate III polymer

Half the amount of the HEMA III terminated polyurethane polymer solution of Example 7 is used for the preparation of the polyurethane acrylate polymer III. After adding 50 ml of IPA, the polymer mixture solution is then heated to about 75 ° C. At the same time, a mixture of 7.4 ml of styrene, 19.3 ml of MMA, 8.62 ml of MAA, 1.142 g of AIBN, and 40 ml of IPA is prepared and subjected to nitrogen bubbling. This mixture is then added to the polymer solution dropwise using a dropping funnel over about 1.5 hours at 75 ° C. Once the addition is complete, the reaction continues for an additional 4 hours. At the end, the polyurethane-acrylate polymer solution is cooled to room temperature. Such acrylic-yrene-acrylate polymers function as shell polymers of core-shell polymer particles.

Example 9: Core-shell polymer particles III (CSPP-III)

With stirring, 50 g of the polyurethane-acrylate polymer solution of Example 8 is diluted with 204 ml of THF, followed by the slow addition of 9.68 g of 10% by weight aqueous KOH solution. A few minutes later, this mixture is added to about 214 g of water with rapid stirring. A milky solution is obtained without visible solid precipitate. The solvent is removed in vacuo and the solution is then filtered through 1 µm filters.

A final solution containing polymer particles having a core-shell structure is obtained: 9.3% solid, particle size = 192 nm, AN = 56, core / shell weight ratio = 2/1. These dispersions remain stable at room temperature for several months.

Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Example 10: determination of the ratio. by core / shell weight

The core / shell weight ratio is determined based on the amount of core polymer, which is equal to the total weight of all of the components used in the preparation of polyurethane, and that of shell polymer, which is equal to the total weight of all the monomers used in the preparation of acrylate polymers.

Example 11: Determination of the Acid Number of Core-Shell Polymer Particles

For polymer particles having a core-shell structure, its acid number (AN) is calculated using the amounts of acid-containing monomer, which is used to stabilize the final polymer particles in water, based on of the following equation:

AN = moles of acid-containing monomer x 6.1 mg KOH x 1000 / (the total mass (g) of monomers used for the preparation of PU and of monomers used for the preparation of acrylate polymers).

Comparative Example A: Polymer B particles (PP-A)

NeoRez ™ R551 is an aqueous polyurethane of aliphatic polyether from DSM Coating Resins Inc. Removal of water from this solution of polymer particles by evaporation at room temperature results in the formation of a transparent polymer film.

Comparative example B: polymer particles B (PP-B)

Neocryl ™ A-1127 is an aqueous acrylic emulsion from DSM Coating Resins Inc. and has a glass transition temperature of -18 ° C and an MFFT of 7 ° C. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Comparative Example C; polymer particles C (PP-C)

Neocryl ™ A-2092 is an aqueous acrylic styrene emulsion from DSM Coating Resins Inc. and has a glass transition temperature of 8 ° C and an MFFT of 6 ° C. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Comparative example D: polymer particles D (PP-D)

NeoPac ™ E200 is an aqueous urethane acrylic emulsion from DSM Coating Resins Inc. and has an MFFT below 0 ° C. It has a core / shell structure, in which acrylate is the core polymer and

Urethane is the shell polymer. Removing water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Comparative example E: polymer particles E (PP-E)

NeoPac ™. E125 is an aqueous acrylic urethane emulsion from DSM Coating Resins Inc. and has an MFFT of less than 10 ° C. It has a core / shell structure, in which acrylate forms the core polymer and urethane forms the shell polymer. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Comparative example F: polymer particles F (PP-F)

Hybridur® 570 is an acrylic-ethane hybrid polymer from Air Products and has an MFFT of less than 10 ° C. Its polymer particles have a core / shell structure, in which acrylate forms the core polymer and urethane forms the shell polymer. Removal of water from this solution of polymer particles by evaporation at room temperature leads to the formation of a transparent polymer film.

Comparative example G: polymer particles G (PP-G)

Preparation of non-vinyl group terminated polyurethane polymer G:

To a 1 liter cylindrical reactor, equipped with a temperature controller, a stirrer, a condenser, and a nitrogen gas line, are added 150.4 g of Fouirez 55-56. After heating the contents to 80 ° C under nitrogen, a clear solution is thus obtained. 22.2 g of IPDI are then added to the mixture dropwise using a dropping funnel or plastic syringe. The reaction temperature is then increased to about 95 ° C and held for 4 hours. Then, 200 ml of EtOAc and 5.38 ml of ethanol are added slowly with stirring, respectively. After the addition is complete, the reaction mixture is held at about 80 ° C for about 4 hours. This batch of non-vinyl group-terminated polyurethane polymer solution is cooled to room temperature under nitrogen for the next step. These polyurethane polymers function as core polymers of subsequently formed polymer particles.

Preparation of polyurethane / acrylate polymer G

The non-vinyl group-terminated polyurethane polymer solution G is used for the preparation of PU / acrylate polymer G. After addition of 100 ml of IPA, the polymer mixture solution is then heated to about 75 ° C. At the same time, a mixture of 18.3 ml of styrene, 26.6 ml of MMA, 41 ml of MAA, 2.93 g of AIBN, and 100 ml of IPA is prepared and subjected to nitrogen bubbling. This mixture is then added to the polymer solution dropwise using a dropping funnel over about 2 hours at 75 ° C. Once the addition is complete, the reaction continues for an additional 3 hours. At the end, the polyurethane / acrylate polymer solution is cooled to room temperature. Such acrylic-styrene-acrylate polymers function as shell polymers of shell polymer core particles.

Preparation of polymer particles G (PP-G)

With stirring, 50 g of the polyurethane / acrylate polymer solution obtained above are diluted with

153 ml of THF, followed by the slow addition of 15 g of 10% by weight aqueous KOH solution. A few minutes later, this mixture is added to about 170 g of water with rapid stirring. A milky solution is obtained without visible solid precipitate, then the solvent is removed under vacuum. A final solution containing polymer particles having a core-shell structure is obtained: particle size = 2460 nm, AN = 107, core / shell weight ratio = 2/1. This batch of polymer particle dispersions quickly becomes unstable at room temperature, with polymer precipitates being observed at the bottom of the sample container.

Example 12: dispersion of carbon black

In this example, the pigment used is a modified carbon black (i.e., a carbon black bonded to at least one organic group), wherein the organic group comprises at least one geminal bisphosphonic acid group or a salt of it. This modified pigment can be prepared, for example, using the procedure described in US Patent Application Publication No. 20070100024.

Example 13: ink compositions

CSPP polymer particles I, II, and III, and comparative PP AG polymer particles are used as additives in ink formulations. Table 1 shows components of ink formulations (IV Inks) containing CSPP1, II, and III. Table 2 shows the components of comparative ink formulations (Comp. I-VI Inks) containing the comparative polymer particles. The amounts listed are in weight percent of the final ink composition. The pigment dispersions and polymer particles are specified on a solid basis.

4.8

Table 1

<td>Component</td><td>Ink I</td><td>Ink II</td><td>Ink III</td><td>Ink IV</td><td>V ink ^:</td>

<td>Dispersion black (pigment)</td><td> 4 %</td><td> 4 %</td><td> 4 %</td><td> 4 %</td><td> 4 %</td>

<td>CSPP-I</td><td> 1 %</td><td></td><td></td><td></td><td></td>

<td>CSPP-II</td><td></td><td> 1 %</td><td></td><td></td><td></td>

<td>CSPP-III</td><td></td><td></td><td> 1 %</td><td></td><td></td>

<td>CSPP-III</td><td></td><td></td><td></td><td> 2 %</td><td></td>

<td>CSPP-III</td><td></td><td></td><td></td><td></td><td> 3 %</td>

<td>Glycerol</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td>

<td>PEG600</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td>

<td>TMP</td><td> 3 %</td><td> 3 %</td><td> 3 %</td><td> 3 %</td><td> 3 %</td>

<td>Surfynol® 465</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td>

<td>Water</td><td>Completed is lying</td><td>Completed is lying</td><td>Completed is lying</td><td>Completed is lying</td><td>Completed is lying</td>

Table 2

<td>Component</td><td>Ink comp. I</td><td>Ink comp. II</td><td>Ink comp. III</td><td>Ink comp. IV</td><td>Ink comp. V</td><td>Ink comp. VI</td>

<td>Dispersio n of black (pigment)</td><td> 4 %</td><td> 4 %</td><td> 4 %</td><td> 4 %</td><td> 4 %</td><td> 4 %</td>

<td>PP-A</td><td> 1 %</td><td></td><td></td><td></td><td></td><td></td>

<td>PP-B</td><td></td><td> 1 %</td><td></td><td></td><td></td><td></td>

<td>PP-C</td><td></td><td></td><td> 1 %</td><td></td><td></td><td></td>

<td>PP-D</td><td></td><td></td><td></td><td> 1 %</td><td></td><td></td>

<td>PP-E</td><td></td><td></td><td></td><td></td><td> 1 %</td><td></td>

<td>PP-F</td><td></td><td></td><td></td><td></td><td></td><td> 1 %</td>

<td>Glycerol</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td>

<td>PEG600</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td><td> 5 %</td>

<td>TMP</td><td> 3 %</td><td> 3 %</td><td> 3 %</td><td> 3 %</td><td> 3 %</td><td> 3 %</td>

<td>Surfynol® 465</td><td> 0,1%</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td><td> 0,1 %</td>

<td>Water</td><td>complete is lying</td><td>complé -is lying</td><td>complé -is lying</td><td>complé -is lying</td><td>complé -is lying</td><td>complé -is lying</td>

Ink evaluation

The inkjet ink compositions of Tables 1 and 2 were evaluated as follows.

The inkjet ink compositions are printed on paper using a Canon ÎP4000 thermal inkjet printer. Each inkjet ink composition is loaded into a compatible Canon cartridge (available from Inkjet Warehouse) and printed with the following printer settings: print quality: high; normal paper; shades of grey ; and no photo option selected. Images are printed on Hewlett-Packard Multifunction Printing (HPMP) paper and Xerox 4200 plain paper. The print properties of the resulting printed images are measured at various times after printing (in particular

5 minutes and 24 hours).

The optical density (OD) of the printed images is measured using a SpectroEye Gretag or X-rite 938 spectrophotometer. For both instruments, the following settings are used: illumination at D65, standard observer 2 degrees, standard DIN density, white base set to Abs, and no filter. The results are expressed as an average of OD values ​​on these two papers. For each paper, the OD value is presented as an average of at least three optical density measurements taken at two corners, and at the center of a page.

Burr resistance (i.e., burr resistance) is measured in a highlight burr test (also referred to as a durability test) using Sharpie ACCENT # 25025 Yellow Highlighter as follows. A single pass or double pass (two passes one above the other) of the highlighter on an unprinted portion of the paper is performed to establish a reference value. Another single or double pass is then made on either side of four 2 mm wide strips printed 3 mm apart. Using the SpectroEye, the optical density (OD) value adjacent to the imprinted region for each pass of the highlighter is measured, along with the baseline OD value. The difference between the reference OD value and the measured OD value adjacent to the printed area (ADO) is the burr resistance value. Usually the values ​​of

ADO are recorded for single pass tests 5 minutes after printing and double pass 24 hours after printing. Presently, a 5 minute post print single pass test and a 24 hour post print double pass test are called Burr Resistance Test I and Burr Resistance Test II, respectively. The results of these two tests are classified as follows:

• A = no or little burr observed (that is, when the two ADO values ​​are not greater than 0.03, both ADO values ​​being measured from a single pass at 5 minutes later. print or double pass at 24 hours after printing on HPMP and Xerox 4200 papers); and • B = a small amount of burr is observed (that is, when at least one of the two values ​​of ADO remains outside the specifications for class A and class C, with both ADO values ​​being measured at from a single pass at 5 minutes after printing or a double pass at 24 hours after printing on HPMP and Xerox 4200 papers); and • C = noticeable smearing is observed (that is, when both ADO values ​​are not less than 0.15, both ADO values ​​are measured from a single pass at 5 minutes after printing or double pass at 24 hours, after printing on HPMP and Xerox 4200 papers).

For each inkjet ink composition, its jet suitability is evaluated by the printing test described as follows:

Each inkjet ink composition is printed using a Canon iP4000 thermal inkjet printer to generate 10 pages of solid black blocks (i.e., with 100% ink coverage) (size: 6.5 inch x 9.5 inch, or 16.51 x 24.13cm) with the following printer settings: print quality: normal; normal paper; gray scale;

and no photo option selected. Images are printed on HPMP paper. These 10 solid black print pages are rated as follows:

• Good = No or few defects;

· Fair = Lines missing on most pages;

• Poor = Many missing lines on most of these 10 pages; and • Bad = Ink cannot be printed with 10 Canon iP4000 printer.

The printing performance results are shown in Table 3.

Table 3

<td>Inks</td><td>% in particle weight s of polymer</td><td>particle of polymer</td><td>DO</td><td>Spray test</td><td>Test held at the burr I</td><td>Resistance test the burr II</td>

<td>Ink I</td><td> 1</td><td rowspan="5">core COULD/ envelope e acrylate</td><td> 1,37</td><td>Well</td><td>B</td><td>B</td>

<td>Ink II</td><td> 1</td><td> 1,37</td><td>Well</td><td>B</td><td>B</td>

<td>Ink III</td><td> 1</td><td> 1, 30</td><td>Well</td><td>AT</td><td>B</td>

<td>Ink IV</td><td> 2</td><td> 1, 38</td><td>Well</td><td>AT</td><td>AT</td>

<td>V ink</td><td> 3</td><td> 1,29</td><td>Well</td><td>AT</td><td>AT</td>

<td>Ink comp. I</td><td> 1</td><td>PU alone</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

<td>Ink comp. II</td><td> 1</td><td rowspan="2">poly- acrylate alone</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

<td>Ink comp. III</td><td> 1</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

<td>Ink comp. IV</td><td> 1</td><td rowspan="3">core acrylate / PU envelope</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

<td>Ink comp. V</td><td> 1</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

<td>Ink comp. VI</td><td> 1</td><td>no value*</td><td>Bad</td><td>no classroom- is lying*</td><td>no classroom- is lying*</td>

* Since such an example cannot be printed with the iP4000 printer, OD measurement and burr resistance tests could not be performed.

As is apparent from the results shown in Table 3, the inkjet printing inks of Ink Examples I to V, which comprise polymer particles having a polyurethane core and a polyacrylate shell, exhibit excellent jetability performance, high optical density, and improved smudge resistance. In these ink examples I to V, the amounts of polymer particles vary from 1% by weight to 3% by weight. On the other hand, the inkjet printing inks of Comparative Ink Examples I to VI, which contain 1% by weight of polymer particles with polyurethane alone, polyacrylate alone, or a polyacrylate core structure and polyurethane wrap, cannot be printed. In addition, the core-shell polymer particles prepared by copolymerization of non-vinyl group-terminated polyurethane and ethylenically unsaturated monomers (i.e., PP-G) are not colloidally stable even. at room temperature.

The use of the terms "a" and "a" and "the" should be considered to include both singular and plural forms, unless otherwise specified or clearly contradicted by the context. The terms "comprising", "having", "comprising", and "containing" are to be considered as open terms (ie, meaning "comprising, but not limited to") unless otherwise indicated. Mention of ranges of values ​​herein is solely intended to serve as an abbreviated method of individually referring to each separate value within the range, unless otherwise specified herein, and each separate value is incorporated into the specification as if it is individually mentioned herein. All of the methods described herein may be performed in any suitable order, unless otherwise stated herein or otherwise clearly contradicted by the context. Use of any and all of the examples, or of an exemplary term (eg, "as") herein described, is intended solely to better illustrate the invention and is not a limitation thereof. this.