JP6030614B2 - Aqueous inkjet ink comprising an ionically stabilized dispersion and a polyurethane ink additive - Google Patents

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from US Provisional Patent Application No. 60/007021 (filed Dec. 10, 2007), the disclosure of which is incorporated herein by reference for all purposes. Therefore, the entire contents thereof are incorporated as described in the present specification.

  The present invention relates to novel aqueous inkjet inks in which pigments are dispersed using ionically stabilized polymeric dispersants and selected polyurethane ink additives that are combined to produce inks, as well as in inkjet inks Regarding its use.

  Aqueous dispersions of pigments are known in the art and include, for example, printing inks (particularly inkjet printing); aqueous paints and other coating formulations for vehicles, buildings, road signs, etc .; cosmetics; pharmaceutical preparations Have been used in various applications such as Because pigments are typically insoluble in aqueous vehicles, it is often necessary to use a dispersant such as a polymeric dispersant or surfactant to produce a stable dispersion of the pigment in the vehicle. .

  The present invention is applied to writing instruments such as water-based ballpoint pens, fountain pens and felt pens; continuous and on-demand type ink jet printers such as thermal jet type and piezo type; and inks useful for ink jet printing methods using ink (printing) Liquid).

  Aqueous pigment dispersions are generally stabilized by one of nonionic or ionic techniques. When nonionic techniques are used, polymers having nonionic hydrophilic moieties that extend into the aqueous medium are typically utilized. The hydrophilic portion provides entropy stabilization or steric stabilization that stabilizes the pigment particles in an aqueous vehicle. Polyvinyl alcohol, cellulose derivatives, ethylene oxide modified phenols and ethylene oxide / propylene oxide polymers can be used for this purpose.

  Nonionic techniques are not sensitive to pH changes or ionic contamination, but have the major disadvantage that the printed image is water sensitive.

  In ionic techniques, the pigment particles are stabilized with a polymer of ion-containing monomers such as neutralized acrylic acid, maleic acid or vinyl sulfonic acid. The polymer provides stabilization through a charged bilayer mechanism where ionic repulsion prevents particle aggregation. Because the neutralizing component tends to evaporate after printing, the polymer has low water solubility and the printed image is less water sensitive than the nonionic stabilizing pigment.

  There continues to be a need for higher quality and different characteristics inks for inkjet ink applications. For example, photographic printing and other multicolor printing require improved inkjet inks. Although improvements in ink additives and polymeric dispersants have contributed significantly to improved inkjet inks, current dispersants still require the required optical density and saturation required for modern inkjet applications. Does not provide inks having

  A new class of dispersants has been described in US 2005/0090599. These ionically stabilized dispersions are described as substantially free of pigment steric stabilization. These ionically stabilized dispersions are obtained from polymeric dispersants with minimal hydrophilic components. While these dispersants have resulted in inks with superior properties, there is a need to find additives that optimize the properties of these ionically stabilized dispersions for use in inkjet inks. Is still there. These additives must improve properties without sacrificing other ink attributes, such as improving image color properties such as saturation without sacrificing optical density.

  Polyurethane has been used as an additive to inkjet inks with varying degrees of success. For example, US Pat. No. 7,176,248 describes the use of polyurethane additives for self-dispersing pigments in inks for inkjet inks, particularly piezo inks.

  U.S. Pat. No. 6,908,185 discusses a combination of a self-dispersing pigment, a polyurethane having a molecular weight of 3000 to 10,000, and a fixing agent.

  US 2005/0176848 A1 claims and discusses combinations of water soluble PUDs, pigments, and 1,2-alkyldiols. Although there is a long explanation of possible dispersant types, there are only examples based on self-dispersing pigments.

  US 2004/0229976 A1 and EP 1454968 A1 are combinations of pigment dispersions and PUDs, wherein the PUD is dispersible and less than 2.0% urea. What has a content is described and claimed. The pigment dispersion may be a self-dispersing pigment or may be a “conventional” dispersing pigment.

  While inks based on aqueous dispersions with polyurethane additives have provided improved ink jet inks for many aspects of ink jet printing, there is still an opportunity to improve these inks. One situation of particular importance is to achieve an improved optical density of the image; saturation and in particular gloss and sharpness (DOI). These must be achieved while maintaining other aspects of the ink, particularly the colored dispersion, such as dispersion stability, long nozzle life, etc.

  All of the above identified documents are hereby incorporated by reference herein in their entirety for all purposes.

  The use of conventional polymeric dispersants with known ink additives is well established as a means of forming inks, particularly inkjet inks. Usually, these conventional dispersants have at least moderate water solubility, and this water solubility is used as a guide to predict dispersion stability. During an enthusiastic search for new and improved polymeric dispersants, a new class of dispersants with little water solubility or water miscibility and very limited hydrophilic content was found. Which can be used to produce stable aqueous dispersions with new and improved properties. A new class of dispersants is described in US Patent Application Publication No. 2005/0090599, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes. It is used as a thing. Further, herein, when these new dispersions are utilized in an ink with at least one specific type of polyurethane ink additive, the optical properties enhanced in the prints resulting from these inks. It was unexpectedly found that it was possible to achieve this.

  A new class of dispersants already described in US 2005/0090599 produces stable aqueous dispersions through ionic stabilization with substantially no steric stabilization. It has been found. When these dispersions are utilized in inkjet inks, images printed with this ink exhibit both improved optical density, saturation, and image sharpness. In accordance with the present invention, when these new classes of dispersants are combined with at least one polyurethane ink additive as described herein, the presence of the selected polyurethane is enhanced without reducing the optical density. Unexpectedly improve the degree and sharpness of the image.

  Dispersions containing this new class of dispersants are referred to herein as ionic stabilized dispersions (ISDs). These dispersants themselves are referred to as ISD polymer dispersants.

  Accordingly, an ink having a dispersant resulting in a stable aqueous dispersion of pigment using an ISD polymer dispersant and a polyurethane ink additive; an ink set comprising at least one ink based on ISD and a polyurethane ink additive; and ISD and Ink jet printing methods using inks and ink sets based on polyurethane ink additives are provided.

According to one aspect of the invention, there is provided an aqueous ink comprising a polyurethane ink additive and a pigment dispersion comprising a pigment and a polymeric ionic dispersant in an aqueous vehicle, wherein:
(A) the ionic dispersant is physically adsorbed on the pigment,
(B) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle;
(C) The average particle size of the dispersion is less than about 300 nm, and (d) 24 hours after addition when 3 drops of ink are added to about 1.5 g of a salt aqueous solution of about 0.20 molar salt. When the pigment precipitates from the aqueous salt solution; and
Here, the polyurethane ink additive comprises: a. ) A urea terminated polyurethane wherein the weight fraction of the urea terminated polyurethane portion of the polyurethane is at least 2% by weight relative to the urethane resin;
b. ) Crosslinked polyurethane in the ink in an amount of greater than about 0.5% to about 30% by weight, based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is about 1% as measured by the THF insolubles test. Selected from the group consisting essentially of more than and less than about 50%.

According to another aspect of the invention, there is provided an aqueous ink comprising a polyurethane ink additive and a pigment dispersion comprising a pigment and a polymeric ionic dispersant in an aqueous vehicle, wherein:
(A) the ionic dispersant is physically adsorbed on the pigment,
(B) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle via ionic stabilization with substantially no steric stabilization; and (c) the average particle size of the dispersion is It is less than about 300 nm.

  According to another aspect of the present invention, there is provided an aqueous pigment inkjet ink comprising an aqueous pigment dispersion comprising a polyurethane ink additive as described above, which is about 0.05 to about based on the total weight of the ink. About 10 wt% polyurethane ink additive, about 0.1 to about 10 wt% pigment based on the total weight of the ink, about 0.5 to about 6 pigment to dispersant weight ratio, about 20 dyne / cm at 25 ° C. Have a surface tension in the range of ˜70 dyne / cm and a viscosity of less than about 30 cP at 25 ° C.

  In yet another aspect of the present invention, there is provided an ink set comprising at least one cyan ink, at least one magenta ink, at least one yellow ink, and optionally at least one black ink, wherein Wherein the at least one ink comprises an ionically stabilized pigment dispersion and at least one selected polyurethane ink additive, as described above and described in further detail below. An aqueous pigment inkjet ink containing.

In yet another embodiment of the invention:
(A) providing an inkjet printer responsive to a digital data signal;
(B) loading the substrate to be printed into the printer;
(C) loading the printer with the ink described above and described in further detail below, or the inkjet ink set described above and described in further detail below; and (D) An inkjet printing method on a substrate is provided that includes printing with ink or an inkjet ink set on a substrate in response to a digital data signal.

  The combination of the ISD dispersed pigment and the selected polyurethane ink additive significantly improved when the image was printed, although the image had an optical density that competed with that achieved with self-dispersing pigments. The result is an ink with gloss and image clarity. These images are also more smear resistant and more durable.

  Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

  Trademarks are shown in capital letters unless explicitly stated.

  Unless otherwise stated, all proportions, parts, ratios, etc. are on a weight basis.

  Where an amount, concentration or other value or parameter is listed as either a range, a preferred range or a list of preferred upper and preferred lower values, this is regardless of whether the ranges are disclosed individually. It should be understood that all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value are specifically disclosed. Where reference is made herein to a numerical range, this range is meant to include the endpoints and all integers and fractions within the range, unless otherwise specified. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.

  Where the term “about” is used in the description of a value or range endpoint, this disclosure should be understood to include the particular value or endpoint referred to.

  As used herein, “comprises”, “comprising”, “includes”, “including”, “has”, “having” The term “having” or any other derivative of any of these is intended to cover non-exclusive inclusions. For example, a process, method, article, or device that includes an enumerated component is not necessarily limited to only those components, and is not explicitly enumerated or such a process, method Other components unique to the article or device may be included. Further, unless expressly stated otherwise, “or” refers to inclusive or not exclusive or. For example, condition A or B is satisfied by any one of the following: A is true (or exists), B is false (or does not exist), and A is false (or exists) Not) and B is true (or present), and both A and B are true (or present).

  The use of “a” or “an” is utilized to describe the components and ingredients of the present invention. This is done merely for convenience and to provide a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

  Except as specifically described, the materials, methods, and examples herein are illustrative only and not intended to be limiting. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Accordingly, an ink having a dispersant that results in a stable aqueous dispersion of pigment using an ionically stabilized dispersant (ISD) polymer dispersant and a selected polyurethane ink additive; at least one based on ISD Ink sets comprising inks and selected polyurethane ink additives and ink-jet printing methods using ink and ISD based ink sets and selected polyurethane ink additives are provided; wherein the selected polyurethane is ,
a. ) A urea terminated polyurethane wherein the weight fraction of the urea terminated polyurethane portion of the polyurethane is at least 2% by weight relative to the urethane resin;
b. ) Crosslinked polyurethane in the ink in an amount of greater than about 0.5% to about 30% by weight, based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is about 1% as measured by the THF insolubles test. Selected from the group consisting essentially of more than and less than about 50%.

Aqueous pigment inkjet inks include polyurethane, aqueous pigment dispersions in an aqueous vehicle, where: aqueous pigment dispersions include ionic dispersants and pigments, where (a) ionic dispersants are physically incorporated into the pigments Adsorbed,
(B) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle;
(C) The average particle size of the dispersion is less than about 300 nm, and (d) 24 hours after addition when 3 drops of ink are added to about 1.5 g of about 0.20 molar salt aqueous solution. When the pigment precipitates from the aqueous salt solution; and the polyurethane ink additive
a. ) A urea terminated polyurethane wherein the weight fraction of the urea terminated polyurethane portion of the polyurethane is at least 2% by weight relative to the urethane resin;
b. ) Crosslinked polyurethane in the ink in an amount of greater than about 0.5% to about 30% by weight, based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is about 1% as measured by the THF insolubles test. It is selected from the group consisting essentially of more than and less than about 50%, preferably consisting of these alone.

  The ink of the present invention has an ionically stabilized pigment dispersion and a polyurethane ink additive. A pigment dispersion is formed in the dispersion process by dispersing a pigment containing an ionically stabilized dispersant. The ink is then preferably prepared by adding the polyurethane ink additive in any order to the ionically stabilized dispersion along with the vehicle and other ink components.

  These polyurethane ink additives are preferred dispersions in aqueous inks. In other words, the polyurethane ink additive is added as a dispersed polymer additive at the ink compounding stage. The chemical properties of urea-terminated polyurethanes and crosslinked polyurethanes are selected to be stable dispersions in typical aqueous ink formulations.

  The combination of the ISD dispersed pigment and the selected polyurethane ink additive significantly improved when the image was printed, although the image had an optical density that competed with that achieved with self-dispersing pigments. The result is an ink with gloss and image clarity. These images are also more smear resistant and more durable. When this combination is compared to the addition of a polyurethane additive to an ink containing a conventional polymer dispersed pigment, the optical density is reduced and the DOI is also reduced. Similarly, the addition of polyurethane additives to inks containing self-dispersing pigments results in comparable optical density, improved gloss and DOI, but this combination is the ISD / polyurethane ink additive combination described herein. It does not provide as good optical properties.

  This surprising result may be due to the interaction of polyurethane and ISD when the ink first encounters the printing substrate. Without being bound by theory, polyurethane is hydrophobic, but it has sufficient hydrophilic properties, especially through the hydrogen bonding sites of the polyurethane, reducing it while significantly improving gloss and image clarity. It can have a high effect that results in an optical density that has not been achieved. These improvements are believed to make inkjet inks successful, especially in the formation of multicolor images for photographic printing.

Ionically Stabilized Dispersions Science and technology to produce stable dispersions utilizing organic polymeric dispersants have been studied and have been extensively developed. In this publication, the type of dispersant is characterized based on the perceived stabilization mechanism. Therefore, the polymer dispersion can stabilize the dispersion by steric stabilization and electrostatic stabilization. In order to provide effective steric or electrosteric stabilization, the dispersant must adhere to the particle surface and interact with the dispersion medium. Both requirements include a dual functionality that features one or more functional groups or segments that bind to or interact with the particle surface, and a segment or tail that extends into the dispersion medium to provide the necessary barrier for stabilization. It can be filled with a polymeric dispersant containing groups. In practice, the optimization of the binary functional groups has resulted in many improved pigment dispersions. This dual functionality is achieved by utilizing a polymer having hydrophilic and hydrophobic segments.

  Alternatively, the polymeric dispersant can stabilize the pigment by an ionic mechanism. That is, the previously described polymer dispersant system suggests that the stabilization mechanism is derived from a polymer that provides stabilization via a charged bilayer mechanism that prevents agglomeration of particles (US Pat. No. 5 , 085, 698).

  While polymeric dispersants are most often described as providing stabilization via steric or ionic mechanisms, in practice most current polymeric dispersant systems are both, but not all, It seems to be stabilized by a combination of mechanisms. These stabilization, described simply in the context of a single mechanism, are now considered to be a combination of steric and ionic mechanisms.

  In the context of the present invention, it has now been recognized that even polymeric dispersants that function substantially without steric stabilization can satisfactorily stabilize the dispersion.

  Therefore, a polymer with a new balance of properties has been sought. The hydrophobic nature of the polymer is important in that it can be attached to the pigment surface, possibly by van der Waals and similar non-binding forces (physical adsorption to the pigment). The main difference between the present invention and the previously described system is that according to the present invention, the hydrophilic portion of the polymer is significantly reduced. Moreover, the hydrophobic / hydrophilic segments of the polymer are allocated to the polymer to minimize the large molecular area of the hydrophilic component. These high density hydrophilic groups can provide undesirable steric stabilization.

  This balance in new properties results in aqueous pigment dispersions with little or no steric stabilization and polymer stabilization mostly due to ionic stabilization only. "Powders, Handling, Dispersion of Powders in Liquids", Kirk-Othmer Encyclopedia of Chemical Technology, as a means of determining the three-dimensionality of John Wiley and Sons (2003) Although present, more general methods have been developed for characterizing the aqueous pigment ISDs according to the present invention that utilize ISD polymeric dispersants. This method is called the salt stability test.

Salt Stability Test A series of different concentrations of aqueous salt solution (typically NaCl) are prepared. For each salt solution, approximately 1.5 mL (about 1.5 g) is added to a small glass vial.

  For the pigment dispersion “concentrate”, one drop is added to the salt solution and mixed gently. For a pigment dispersion concentrate of about 15 wt% total solids (typically), a drop will typically total about 0.04 g. Tests on ink (which can be considered as a diluted form of the concentrate) have a lower solids content of the ink than that of the pigment dispersion concentrate, thus keeping the estimated solids the same This is quite similar to the salt stability test for pigment dispersion concentrates, except that the volume of ink added to the salt solution needs to be increased. Based on a typical ink of about 5 wt% total solids, about 3 times the weight of ink (compared to the concentrate) is required.

  For the pigment dispersion concentrates described above, the weight of solids from the concentrate is about 0.006 g in about 1.5 g of the aqueous salt test solution, or based on the weight of the aqueous salt test solution. It will be about 0.4% by weight.

It should be noted that the 0.4 wt% number derived above is not critical for salt stability test applications, but can be used as a reference point if desired. Because the results of the salt stability test are related to the concentration of salt relative to the solids, and because it can be somewhat difficult to accurately measure the solids content of the pigment dispersion, The following convention shall be adopted:
For pigment dispersions considered as concentrates (greater than about 10 wt% solids), one drop of dispersion should be used in a 1.5 mL salt solution;
For medium solids content pigment dispersions (about 5-10 wt% solids inks and / or concentrates), 2 drops of dispersion should be used in 1.5 mL salt solution and more diluted For pigment dispersions (such as inks up to about 5 wt% solids), 3 drops of dispersion should be used in 1.5 mL salt solution.

  For the inks of the present invention, 3 drops are used to perform this salt stability test, but 1 or 2 drops may be used if the pigment dispersion has a higher concentration.

Based on the above, an appropriate amount of pigment dispersion is added to the salt solution and mixed gently. After standing at room temperature for 24 hours, sample stability is rated as follows:
Grade 3: Complete precipitation of pigment; clear, colorless liquid on top.
Grade 2: no clear, colorless liquid layer; when the vial is tilted, a clear settling is observed at the bottom of the vial.
Grade 1: no clear, colorless liquid layer; very slight sedimentation (small isolated spots) is observed while tilting the vial.
Grade 0: No signs of settling.

  The salt concentration at which sedimentation is clearly observed (grade 2 or 3) is taken as the critical aggregation concentration for the pigment dispersion. From this test, it can be inferred that as the critical aggregation concentration increases, the role of macromolecular (steric) stabilization becomes more dominant, and the importance as a stabilization mechanism of electrostatic stabilization decreases. .

  An ISD polymer dispersant that meets the requirements for the present invention is one that results in a pigment dispersion rated as grade 2 or 3 at a 0.2 molar salt concentration. That is, the ISD polymer dispersant of the present invention will be observed to precipitate from the test solution at a 0.2 molar salt concentration when associated with a pigment in the ISD and when tested by the salt stability test. . Rating criteria 2 and 3 will each meet the criteria for deposition. More preferred are pigment dispersions rated 2 or 3 at a salt concentration of about 0.18 molar or less. Even more preferred are pigment dispersions rated 2 or 3 at a salt concentration of about 0.16 or less.

  Preferred salts for the aqueous salt solution are lithium, sodium or potassium salts.

  As indicated above, and for further clarity, salt stability tests are applicable for a wide variety of pigment dispersion solids contents. Although the definition of 1 drop, 2 drops or 3 drops for the test does not clearly define the amount of solids added, this test is quite flexible and these generalities effectively make the sample effective in a consistent manner. It was found to be sufficient to rate. In other words, the tests defined above yielded consistent and meaningful results regardless of deviations in the solids content of the dispersions being tested and were therefore adopted as definitions in the context of the present invention. Further details and practical application of the salt stability test (which specifically demonstrates the consistency of this result) are provided in the Examples section below.

  The ionic stabilized dispersions of the present application are stabilized by the presence of a minimum amount of ionic content in the dispersant and limited or negligible steric stabilization content in the dispersant. The It is surprising that the resulting pigment dispersion is so stable even though it contains only a very small amount of ionic components. The salt stability test is a means of identifying the low ionic character of this dispersion that the dispersion will be adversely affected by the addition of salt. This effect is observed in the pigment precipitation described in the salt stability test.

A large category of dispersed pigments that are likely to pass this salt stability test are pigments that have been processed as self-dispersing pigments (SDP). However, SDP does not meet the criteria of the present invention in that no polymeric dispersant is included in the system. The ink or dispersion test to determine the presence of SDP is as follows:
(A) Acidify the ink (or dispersion) by adding HCl. This converts water soluble components on SDP and dispersants such as COO ⁻ , SO ₃ ⁻ , phosphonates, etc. to acidified form, thereby reducing the solubility of pigments and dispersants in aqueous media. The hydratable cosolvent and surfactant should be dissolved in the aqueous phase by this step. The resulting solid is separated. Alternatively, for cation-based inks, ammonia can be added to basify the cationic stabilizing group.
(B) The obtained solid is extracted with tetrahydrofuran (THF). This removes the binder and dispersant from the separated solids, leaving a pigment that is substantially free of polymer. An encapsulant bound to the pigment can remain on the pigment.
(C) The obtained solid is dried.
(D) Redisperse the pigment with water and adjust the pH to about 9.
(I) When the pigment is redispersed in solution, the pigment is SDP with the dispersed portion covalently bonded to the pigment particles.
(Ii) If the pigment is not redispersed and remains undissolved, this is not SDP, but a conventional pigment converted to a stable dispersion by the polymer component removed in step (b) It is.
(E) The obtained solid is dried.

  If the pigment is a mixture of SDP and a conventional pigment containing a dispersant such as that described in US Pat. No. 6,440,203, already incorporated, the pigment left in step (e) May be a conventional polymer dispersed pigment, and the difference between the mass in step (c) and the mass in (e) would be the SDP that constituted the pigment mixture.

  The ISD polymer dispersant of the present invention has a binary functional group. The main part is hydrophobic having an attractive force to the pigment surface. The hydrophilic part is the resulting pigment / ISD polymer dispersion when the resulting pigment dispersant has little or no steric stabilization and is tested by a salt stability test in a 0.2 molar salt solution. The agent is limited to precipitate.

  ISD polymers can be formed by reacting well-defined hydrophobic and hydrophilic characteristic monomers. Examples of these monomers are acrylic monomers and acrylate monomers, which are described below. Alternatively, the ISD properties of the polymeric dispersant can be the result of the reaction of other types of monomers. An example of this is a polyurethane dispersant that meets the ISD salt stability criteria, where an advantageous balance of hydrophobic and hydrophilic properties is derived from both the monomers and end-capping moieties used in polyurethane synthesis. Therefore, the resulting hydrophobic / hydrophilic balance in the final polyurethane product meets the above criteria.

  ISD polymer dispersants are prepared by polymerization of hydrophobic and hydrophilic monomers. When tested as a polymeric dispersant containing pigment, the final polymer results in a dispersion that precipitates when the resulting pigment / ISD polymer dispersant is tested by a salt stability test in a 0.2 molar salt solution. There is no limitation on the means for polymerizing these monomers.

  ISD polymer dispersants can be random; linear copolymers; or structured polymers such as diblock (AB) or triblock (ABA or BAB) polymers, or graft or branched polymers. possible. The polymer can be formed by any of a number of well-known polymerization processes including free radicals, ions, group transfer (GTP), radical addition fragmentation (RAFT), atom transfer reactions (ATR), condensation reactions and the like. is there. The general conditions and examples of such polymerization processes are disclosed in many of the literature already incorporated.

  The ISD polymer dispersant of the present invention has a binary functional group. The main part is hydrophobic having an attractive force to the pigment surface. The hydrophilic portion was tested by a salt stability test with a 0.2 molar salt solution where the resulting pigment dispersant had little or no steric stabilization and the resulting pigment / ISD polymer dispersant. It is limited to precipitate in some cases.

  ISD polymers can be formed by reacting well-defined hydrophobic and hydrophilic characteristic monomers. Examples of these monomers are acrylic monomers and acrylate monomers, which are described below. Alternatively, the ISD properties of the polymeric dispersant can be the result of the monomer reaction. An example of this is a polyurethane dispersant that meets the ISD salt stability criteria, where an advantageous balance of hydrophobic and hydrophilic properties results in the monomers used in the polyurethane synthesis and the final polyurethane product. It can come from both the hydrophobic / hydrophilic balance.

  Preferred ISD polymer dispersants are prepared by polymerization of hydrophobic and hydrophilic monomers such as acrylates and acrylics. When tested as a polymeric dispersant containing pigment, the final polymer results in a dispersion that precipitates when the resulting pigment / ISD polymer dispersant is tested by a salt stability test in a 0.2 molar salt solution. There is no limitation on the means for polymerizing these monomers.

  ISD polymer dispersants derived from acrylic / acrylate monomers can be random; linear copolymers; or diblock (A-B) or triblock (A-B-A or B-A-B) polymers, or grafts or branches It can be a structured polymer such as a polymer. The polymer can be formed by any of a number of well known polymerization processes including free radicals, ions, group transfer (GTP), radical addition fragmentation (RAFT), atom transfer reactions (ATR) and the like. The general conditions and examples of such polymerization processes are disclosed in many of the literature already incorporated.

Polymeric dispersants derived from acrylic / acrylate monomers are copolymers of hydrophobic and hydrophilic monomers. Precursor monomer is capable of being displayed as follows, wherein, A represents a monomer for hydrophobic segments, B represents a monomer for the hydrophilic segments, Z _a is on the A monomer Indicates a hydrophobic substituent, and Z _b indicates a hydrophilic substituent on the B monomer. One type of two or more types of monomers can be present in each segment.

For A and B, preferred examples of structures that would result in an ISD dispersant are the group consisting of alkyl, aryl or alkylaryl groups, where each of R ^a -R ^f has H and 1-20 carbons As well as where Z _a and Z _b are those described below. In one preferred embodiment, each of R ^a -R ^f is selected from the group consisting of H and CH ₃ . In other preferred embodiments, each of R ^a -R ^b and R ^d -R ^e is H, and each of R ^c and R ^f is independently selected from H and CH ₃ .

The hydrophilic composition of the ISD polymer dispersant is minimal compared to known polymeric dispersants described in many of the literature already incorporated. The hydrophilicity of the ISD polymer dispersant is derived from the ionic substituent (Z _b ) on monomer B.

Z _b groups are anionic, it is possible cationic, amphoteric or zwitterionic hydrophilic components. A nonionic component is also included in the polymeric dispersant unless it includes sufficient steric stabilization so that the polymeric dispersant containing the pigment does not meet the criteria defined by the salt test. It is possible that For polymers containing nonionic components, the salt test requires any hydrophobic / hydrophilic / nonionic balance to achieve a “failed” salt test at an ionic concentration of 0.2 mole or less. A means for determining whether or not there is provided. Examples of Z _b groups are:
-Anionic, e.g. sulfonate, sulfate, sulfosuccinate, carboxylate, phosphate-cationic, e.g. amines including quaternary amine salts-amphoteric, e.g. N-> O
- zwitterionic, for example, _{betaines, + N-C-CO 2} -, lecithin.

The hydrophilic monomer can have a single Z _b substituent or a combination of Z _b groups. The Z _b group exists as its hydrogen-substituted form or as a salt.

  Preferred hydrophilic monomers include, for example, methacrylic acid, acrylic acid, maleic acid, maleic acid monoester, itaconic acid, itaconic acid monoester, crotonic acid, crotonic acid monoester, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, t-butylaminoethyl methacrylate, t-butylaminoethyl acrylate, vinyl pyridine, N-vinyl pyridine, and 2-acrylamide- 2-propanesulfonic acid is mentioned.

  Other hydrophilic nonionic monomers may be included. Preferred hydrophilic monomers include, for example, ethoxytriethylene glycol methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-ethoxyethyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate.

Hydrophobic compositions of ISD polymer dispersants are maximized compared to known polymeric dispersants described in many of the literature already incorporated. The hydrophobicity of the ISD polymer dispersant is derived from the hydrophobic substituent (Z _a ) on monomer A.

In a preferred embodiment, the Z _a:
(A) alkyl, aryl and alkylaryl groups containing from 1 to 20 carbon atoms, which may further contain one or more heteroatoms;
(B) a group of the structure C (O) OR ^g , wherein R ^g is selected from the group consisting of alkyl, aryl and alkylaryl groups containing from 1 to 20 carbon atoms, in one or more further group which may contain a hetero atom, and (c) the structure ^{C (O) NR h R i} ( wherein each of R ^h and R ⁱ are, H, and, from 1 to 20 Groups independently selected from the group consisting of alkyl, aryl and alkylaryl groups containing 1 carbon atom, which may further contain one or more heteroatoms Selected from the group.

  Preferred hydrophobic monomers are usually, for example, benzyl methacrylate, butyl methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, lauryl etacrylate, stearyl methacrylate, phenyl methacrylate, phenoxy. Ethyl methacrylate, methacrylonitrile, glycidyl methacrylate, p-tolyl methacrylate, sorbyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, phenyl Acrylate, Enoxyethyl acrylate, acrylonitrile, glycidyl acrylate, p-tolyl acrylate, sorbyl acrylate, styrene, α-methyl styrene, substituted styrene, N-alkyl acrylamide, N-alkyl methacrylamide, vinyl acetate, vinyl butyrate and vinyl benzoate Acid salts.

Preferred examples of A (hydrophobic) is Z _a is ^{C (O) OR g, C} (O) NR h R i and acrylic monomer selected from the group consisting of CN. In one preferred embodiment, R ^g is selected from the group consisting of alkyl, aryl and alkylaryl groups having 1 to 20 carbon atoms, the group further containing one or more heteroatoms. And R ^h and R ⁱ are independently selected from the group consisting of H and alkyl, aryl or alkylaryl groups having 1 to 9 carbon atoms. The polymer segment of the A monomer preferably has a number average molecular weight of at least about 300 and is water insoluble.

  This list is not limiting in that any polymer system that produces an ISD polymer dispersant (ie, produces an ISD that satisfies the salt stability test) will meet the polymer requirements of the present invention. .

  There is no limitation on the polymerization method in which the monomers A and B are combined to prepare the ISD polymer dispersant. Examples of polymerization methods include, but are not limited to, free radical processes, group transfer processes (GTP), and the like.

  Preferred ISD polymer dispersants derived from acrylic / acrylate monomers for use in the context of the present invention are greater than 300, preferably greater than 800, and less than about 30,000, preferably less than about 20,000, and typically Has a number average molecular weight in the range of about 1,000 to about 6,000.

  ISD polymer dispersants derived from acrylic / acrylate monomers are limited to the amount of ionic inclusions. For random, linear copolymers, diblocks, grafts and branched polymers, the hydrophilic monomer limit is from about 1 mole percent to less than about 20 mole percent based on all monomers. Alternatively, the hydrophilic monomer limit is from about 2 mole percent to less than about 15 mole percent based on all monomers. For ABA triblocks, the limit is from about 2 mole percent to less than about 38 mole percent and, alternatively, less than about 25 mole percent. For BAB triblocks, the limit is from about 2 mole percent to less than about 25 mole percent. For each of these ionic limits, the salt stability test of the pigment dispersion or inkjet ink is a determining factor for the ionic content.

  One of the consequences of the low hydrophilic content of ISD polymer dispersants derived from acrylic / acrylate monomers is their low water solubility. Water is, of course, a preferred medium for inkjet inks. Therefore, to prepare stable aqueous dispersions from ISD polymer dispersants, pigments and ISD polymers derived from acrylic / acrylate monomers so that it is possible to obtain an initial physical mixture of dispersant and pigment. It is preferred that the initial mixture of dispersant includes a hydratable solvent that sufficiently solubilizes the ISD polymer dispersant. This ISD polymer dispersant, pigment and solvent mixture derived from acrylic / acrylate monomers can then be processed by conventional dispersion processes to form a stable ISD polymer dispersant / pigment combination in an aqueous vehicle. Is possible. This aqueous vehicle can therefore be a combination of water and a hydrating solvent. Candidate solvent systems can be determined by studying the solubility of ISD polymer dispersants derived from acrylic / acrylate monomers using well-known solubility parameter methods.

  Other preferred polymer systems with respect to ISD polymer dispersants are isocyanate, diol and ionic configurations so as to obtain polyurethanes that can act as dispersants and meet ISD criteria as determined by salt stability tests. A urea-terminated polyurethane with selected ingredients. The urea-terminated polyurethanes described below have minimal ionic content, resulting in urea-terminated polyurethanes that meet this ISD criterion. The polyurethane ink additives described below can be ISD dispersants when the balance of properties meets the criteria for salt stability.

  The ISD and ink compositions of the present invention can be prepared by methods known in the art. It is generally desirable to form the ISD in a concentrate form, after which it is diluted with a suitable liquid containing the desired additives. ISD first premixes the selected pigment and ISD polymer dispersant in an aqueous carrier medium (such as water and optionally a water-miscible solvent) and then disperses or deagglomerates the pigment. It is prepared by. The dispersing step may be performed in a 2-roll mill, media mill, horizontal minimill, ball mill, attritor, or by passing the mixture through a plurality of nozzles in a liquid jetting interaction chamber at a liquid pressure of at least 5,000 psi. Can be achieved by producing a uniform dispersion (microfluidizer) in an aqueous carrier medium. Alternatively, the concentrate can be prepared by drying mill the polymer dispersant and pigment under pressure. The media for the media mill is selected from commonly available media including zirconia, YTZ and nylon. These various dispersion processes are described in US Pat. No. 5,225,292, US Pat. No. 5,026,427, US Pat. No. 5,310,778, US Pat. No. 5,891,231, US Pat. No. 5,679,138, US It is well known in the art in a general sense, as exemplified by US Pat. No. 5,976,232 and US Patent Application Publication No. 20030089277. All of these documents are hereby incorporated by reference herein in their entirety for all purposes. The 2-roll mill, media mill, and mixture are preferably passed through a plurality of nozzles in the liquid jet interaction chamber at a liquid pressure of at least 5,000 psi.

  After the mill process is complete, the pigment concentrate can be “thinned” into the aqueous system. “Thinned” refers to dilution of the concentrate in the mix or dispersion, and the intensity of the mix / dispersion is usually determined by error using trial and conventional methods, and often the polymeric dispersant, solvent and Depends on the pigment combination. It is necessary to determine the conditions for sufficiently thinning all combinations of the polymer dispersant, the solvent and the pigment.

  After the preparation of the ISD, the amount of hydratable solvent can exceed the amount that some inkjet applications would allow. For some ISDs, it may therefore be necessary to ultrafilter the final dispersion to reduce the amount of hydrating solvent. In order to improve the stability and reduce the viscosity of the pigment dispersion, a heat treatment can be performed by heating at a temperature of about 30 ° C. to about 100 ° C., preferably about 70 ° C., for about 10 to about 24 hours. Longer heating does not affect the performance of the dispersion.

  The amount of polymeric ISD dispersant required to stabilize the pigment depends on the particular ISD dispersant, pigment and vehicle interaction. The weight ratio of pigment to polymeric ISD dispersant will typically range from about 0.5 to about 6. A preferred range is from about 0.75 to about 4.

  While not being bound by theory, it is believed that ISD provides improved ink properties by the following means. A stable aqueous dispersion is critical because the inkjet ink ensures a long life of the ink cartridge and reduces problems such as nozzle clogging. However, the ink is unstable as it is jetted onto the media so that the pigment in the ink “crash out” onto the surface of the media (as opposed to being absorbed by the media). It is desirable to become. By having the pigment on the surface of the media, it is possible to achieve the beneficial properties of the ink.

  ISD polymer dispersants sufficiently stabilize the ink before jetting (such as in a cartridge), but as the ink is jetted onto the paper, it destabilizes the pigment system and removes the pigment. A novel dispersant is provided that remains on the surface of the media. This results in improved ink properties.

  The hydrophobic nature of inkjet inks formed by ISD significantly improves optical density and saturation. IS & T's NIP 18: 2002, International Conferencing on Digital Printing Technologies, page 369, a recent discussion of pigment inks shows a hydrophobic pigment formulation that, when jetted onto plain paper, results in a pigment remaining on the paper surface Is described. This surface deposit of pigment provides better optical density and saturation. The ISD of the present invention achieves an even better combination of optical density, saturation, gloss and image sharpness with higher levels of hydrophobicity.

Polyurethane ink additive A polyurethane ink additive is a polyurethane having a urethane bond in the main chain of the polyurethane structure. These polyurethanes can be soluble or in the form of colloidal dispersions, emulsions, suspensions or slurries.

  A preferred form of polyurethane ink additive is water dispersible polyurethane. According to the present invention, the term “polyurethane additive” can refer to an aqueous dispersion of a polymer containing urethane groups and optionally urea groups, as the term is understood by those skilled in the art. These polymers also incorporate hydrophilic functional groups to the extent required to maintain a stable dispersion of the polymer in water.

  Preferred polyurethane ink additives are those in which the polymer is stabilized in the dispersion primarily through incorporated ionic functional groups, such as neutralized acid groups, especially anionic functional groups. ("Anionically stable polyurethane dispersion"). Further details are provided below.

  Further preferred polyurethane ink additives include a. ) Urea end-capped, or b. ) Or cross-linked. The urea terminated polyurethane has a weight fraction of the urea terminated polyurethane portion of the polyurethane of at least 2% by weight relative to the urethane resin. Crosslinked polyurethane is present in the ink in a weight range of greater than about 0.5% to about 30% by weight based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is measured by a THF insoluble content test. And more than about 1% and less than about 50%.

  Such aqueous polyurethane ink additives typically have an isocyanate (N═C═O, NCO) prepolymer having an excess amount of NCO groups first formed and then the chain is monofunctional isocyanate reaction. It is end-capped with a functional group or is prepared by a multi-stage process in which the chain is extended in the aqueous phase, optionally in the presence of a polyfunctional chain extender. In the case of polyfunctional chain extenders, this will result in crosslinking of the polyurethane additive. NCO prepolymers are also typically formed by a multi-stage process. For urea terminated polyurethanes, the NCO prepolymer is reacted with a primary or secondary amine to urea-cure the polyurethane. Although other means of forming a crosslinked polyurethane are described below, preferred crosslinked polyurethanes also have an NCO prepolymer as an important intermediate, which is then at least a trisubstituted secondary and / or first Reacted with a secondary amine to produce a crosslink. During crosslinking, mono- and disubstituted amines may be present along with trisubstituted crosslinkers.

  Typically, in the first stage of prepolymer formation, the diisocyanate reacts with a compound containing one or more isocyanate-reactive groups and at least one acid or acid base to produce an intermediate. A product is formed. The acid or acid base can be part of a diisocyanate compound or part of a compound containing an isocyanate-reactive group. The molar ratio of isocyanate groups to isocyanate-reactive groups is such that the equivalent of isocyanate functional groups is greater than the equivalent of isocyanate-reactive functional groups, resulting in an intermediate product end-capped with at least one NCO group. Is. Therefore, the molar ratio of isocyanate groups to isocyanate-reactive groups is at least about 1.01 to 1.4: 1, preferably 1.05 to 1.25: 1 and more preferably 1.1 to 1.15. : 1. As an example, diisocyanates are reactive with diols in the presence of diols having ionic groups to produce an isocyanate-rich isocyanate prepolymer that is then further reacted.

  Suitable isocyanates are those containing either aromatic, alicyclic or aliphatic groups attached to isocyanate groups. Mixtures of these compounds can also be used. Compounds having an isocyanate bonded to an alicyclic or aliphatic moiety are preferred. If aromatic isocyanates are used, it is preferred that alicyclic or aliphatic isocyanates are also present. Structures I and R1 can preferably be substituted with an aliphatic group.

  Diisocyanates are preferred and any diisocyanate useful in the preparation of polyether glycols, polyurethanes and / or polyurethane-ureas from diisocyanates and diols or amines can be used in the present invention.

Examples of suitable diisocyanates include, but are not limited to, 2,4-toluene diisocyanate (TDI); 2,6-toluene diisocyanate; trimethylhexamethylene diisocyanate (TMDI); 4,4′-diphenylmethane diisocyanate (MDI); 4,4′-dicyclohexylmethane diisocyanate (H ₁₂ MDI); 3,3′-dimethyl-4,4′-biphenyl diisocyanate (TODI); dodecane diisocyanate (C ₁₂ DI); m-tetramethylene xylylene diisocyanate (TMXDI) 1,4-benzene diisocyanate; trans-cyclohexane-1,4-diisocyanate; 1,5-naphthalene diisocyanate (NDI); 1,6-hexamethylene diisocyanate (HDI); Li diisocyanate; isophorone diisocyanate (IPDI); and combinations thereof. IPDI and TMXDI are preferred.

  Small amounts, preferably less than about 3% by weight monoisocyanate or polyisocyanate, based on the weight of the diisocyanate, can be used in the mixture with the diisocyanate. Examples of useful monoisocyanates include alkyl isocyanates such as octadecyl isocyanate and aryl isocyanates such as phenyl isocyanate. Examples of polyisocyanates are triisocyanatotoluene HDI trimer (Desmodur 3300), and polymeric MDI (Mondur MR and MRS).

  Isocyanate-reactive compounds containing acid groups, i.e., carboxylic acid groups, carboxylate groups, sulfonic acid groups, sulfonic acid groups, phosphoric acid groups and phosphonic acid groups are chemically incorporated into polyurethanes to provide hydrophilicity. And the polyurethane is stably dispersed in the aqueous medium. The acid salts are formed by neutralizing the corresponding acid groups either before, during or after the formation of the NCO prepolymer, preferably after the formation of the NCO prepolymer. Preference is given to isocyanate-reactive compounds containing carboxylic acids or carboxylates.

  Suitable compounds for incorporating carboxyl groups are described in US Pat. No. 3,479,310, US Pat. No. 4,108,814 and US Pat. No. 4,408,008. Which are hereby incorporated by reference herein in their entirety for all purposes. Neutralizing agents for converting carboxylic acid groups to carboxylic acid groups are described in the aforementioned US patents and are also described later in this specification. In the context of the present invention, the term “neutralizing agent” is meant to encompass all types of agents useful for converting carboxylic acid groups to hydrophilic carboxylic acid groups.

Preferred carboxylic acid group-containing compounds have the structure (HO) _j Q (COOH) _k , where Q represents a linear or branched hydrocarbon radical containing 1 to 12 carbon atoms, j is 1 or 2, preferably 2, and k is 1 to 3, preferably 1 or 2, more preferably 1).

  Examples of these hydroxy-carboxylic acids include citric acid, tartaric acid and hydroxypivalic acid. Particularly preferred acids are those described above (where j = 2 and k = 1). These dihydroxyalkanoic acids are described in U.S. Pat. No. 3,420,054, which is incorporated herein by reference in its entirety for all purposes. Particularly preferred dihydroxyalkanoic acids are structural formulas:

（式中、Ｑ’は水素、または、１〜８個の炭素原子を含有するアルキル基である）
によって表されるα，α−ジメチロールアルカン酸である。もっとも好ましい化合物は、α，α−ジメチロールプロピオン酸（すなわち、上記式において、Ｑ’がメチルである）である。

(Wherein Q ′ is hydrogen or an alkyl group containing 1 to 8 carbon atoms)
The α, α-dimethylolalkanoic acid represented by The most preferred compound is α, α-dimethylolpropionic acid (ie, Q ′ is methyl in the above formula).

  The acid groups are incorporated in an amount sufficient to provide an ionic group content of at least about 10, preferably at least about 18 milligrams of KOH / 1 gram polyurethane resin solids. The upper limit for the content of acid groups is about 100, preferably about 60, and more preferably about 40 milligrams per gram of polyurethane resin solids. This ionic group content is equal to the acid value of the solid content of the polyurethane resin.

  Isocyanate-reactive group compounds include polyols, particularly diols. Suitable polyols containing at least two hydroxy groups that can be reacted with a pre-adduct to prepare an NCO prepolymer are about 120 to about 6000, preferably about 400 to about 3000, and more preferably about 600 to about 3000. It has a molecular weight of 2500. The molecular weight is a number average molecular weight (Mn) and is measured by end group analysis (OH number, hydroxyl analysis). Examples of these high molecular weight compounds include polyester polyols, polyether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers. A combination of polyols can also be used in the polyurethane.

  Suitable polyester polyols include reaction products of polyvalent, preferably dihydric alcohols to which trihydric alcohols can be added and polybasic, preferably dibasic carboxylic acids. Instead of these polycarboxylic acids, the corresponding carboxylic anhydrides or polycarboxylic acid esters of lower alcohols or mixtures thereof can be used for the preparation of the polyesters. The polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic, which can be substituted, for example, with halogen atoms and / or unsaturated. Examples include: succinic acid; adipic acid; suberic acid; azelaic acid; sebacic acid; phthalic acid; isophthalic acid; trimellitic acid; phthalic acid anhydride; tetrahydrophthalic acid anhydride; Chlorophthalic anhydride; endomethylenetetrahydrophthalic anhydride; glutaric anhydride; maleic acid; maleic anhydride; fumaric acid; dimer such as oleic acid, in which monomeric fatty acids may be mixed, and Trimeric fatty acids; dimethyl terephthalate and bis-glycol terephthalate.

  Suitable polyhydric alcohols include, for example, ethylene glycol; propylene glycol- (1,2) and-(1,3); butylene glycol- (1,4) and-(1,3); hexanediol- (1 6); Octanediol- (1,8); Neopentyl glycol; Cyclohexanedimethanol (1,4-bis-hydroxymethyl-cyclohexane); 2-methyl-1,3-propanediol; Examples include trimethyl-1,3-pentanediol; triethylene glycol; tetra-ethylene glycol; polyethylene glycol; dipropylene glycol; polypropylene glycol; dibutylene glycol and polybutylene glycol, glycerin, and trimethylol-propane.

  The polyester may also contain a portion of carboxyl end groups. Polyesters of lactones such as ε-caprolactone or hydroxycarboxylic acids such as ω-hydroxycaproic acid can also be used.

  Polycarbonates containing hydroxyl groups include diols such as propanediol- (1,3), butanediol- (1,4) and / or hexanediol- (1,6), diethylene glycol, triethylene glycol or tetraethylene glycol. Those known per se, such as products obtained from reaction with diaryl carbonates such as phosgene, diphenyl carbonate or with cyclic carbonates such as ethylene or propylene carbonate. Also suitable are polyester carbonates obtained from the aforementioned polyesters or polylactones and phosgene, diaryl carbonates or cyclic carbonates. Suitable polyether polyols are the reaction of starting compounds containing reactive hydrogen atoms with alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin, or mixtures of these alkylene oxides. In a known manner. More preferably, polyethers obtained without addition of ethylene oxide are used. Suitable starting compounds containing reactive hydrogen atoms include the polyhydric alcohols described for the preparation of polyester polyols, as well as water, methanol, ethanol, 1,2,6-hexanetriol, 1 , 2,4-butanetriol, trimethylolethane, pentaerythritol, mannitol, sorbitol, methylglycoside, sucrose, phenol, isononylphenol, resorcinol, hydroquinone, 1,1,1- or 1,1,2-tris- (hydroxy Phenyl) ethane.

  A preferred polyether diol is derived from 1,3-propanediol (PO3G). The employed PO3G can be obtained by any of a variety of well known chemical or biochemical transformation pathways. Preferably, 1,3-propanediol is obtained biochemically from renewable raw materials ("biologically derived" 1,3-propanediol). A description of this biochemically obtained 1,3-propanediol can be found in co-pending and co-pending US patent application Ser. No. 11/782098 (filed Jul. 24, 2007). This disclosure is hereby incorporated by reference herein in its entirety for all purposes.

  Polyethers obtained by reaction of starting compounds containing amine compounds can also be used, but are less preferred for use in the present invention. Examples of these polyethers, as well as suitable polyhydroxypolyacetals, polyhydroxypolyacrylates, polyhydroxypolyesteramides, polyhydroxypolyamides and polyhydroxypolythioethers are incorporated by reference herein in their entirety for all purposes. Is disclosed in U.S. Pat. No. 4,701,480, incorporated herein by reference.

  Examples of the poly (meth) acrylate containing a hydroxyl group include those commonly used in the technical field of addition polymerization such as cationic, anionic, radical, and polymerization. α-ω diols are preferred. An example of these types of diols are those prepared by “living” or “controlled” or chain transfer polymerization processes that allow the placement of one hydroxyl group at or near the end of the polymer. U.S. Pat. No. 6,248,839 and U.S. Pat. No. 5,990,245 (both incorporated herein by reference in their entirety for all purposes) Have examples of procedures for forming terminal diols.

  Other optional compounds for preparing the NCO prepolymer include low molecular weight, at least bifunctional isocyanate-reactive compounds having an average molecular weight of about 400 or less. Examples include dihydric and higher functional alcohols already described for the preparation of polyester polyols and polyether polyols.

  Preferably, in addition to the above-mentioned components that are difunctional in the isocyanate polyaddition reaction, in monofunctional moieties, and also in polyurethane chemistry such as trimethylolpropane or 4-isocyanato-methyl-1,8-octamethylene diisocyanate A small portion of commonly known trifunctional and higher order functional components can be used in special cases where a slight branch of NCO prepolymer or polyurethane is desired. However, the NCO prepolymer should be substantially linear, and this can be achieved by maintaining the average functionality of the prepolymer starting components at 2: 1 or less.

  Other optional compounds include isocyanate-reactive compounds containing lateral or terminal, hydrophilic ethylene oxide units. The content of hydrophilic ethylene oxide units (if present) can be about 50 wt% or less, preferably about 40 wt% or less, based on the weight of the polyurethane.

  Other optional compounds include isocyanate-reactive compounds containing self-condensable moieties. The content of these compounds depends on the desired level of self-condensation necessary to provide the desired resin properties. 3-amino-1-triethoxysilyl-propane is an example of a compound that will react with an isocyanate via an amino group and will self-condense via a silyl group when converted to water.

  Non-condensable silanes having isocyanate-reactive groups can be used in place of or in conjunction with isocyanate-reactive compounds containing self-condensable moieties. US Pat. No. 5,760,123 and US Pat. No. 6,046,295 (both incorporated herein by reference in their entirety for all purposes) Is an exemplary method for the use of any of these silane-containing compounds.

  Process conditions for preparing NCO prepolymers are discussed in patents already incorporated by reference. The final NCO prepolymer should have a free isocyanate content of about 0.5 to about 20%, preferably about 1 to about 10% by weight, based on the weight of prepolymer solids.

  Polyurethanes can be prepared by extending the chain length of these NCO prepolymers. Chain extenders are described in US Pat. No. 4,269,748, which is incorporated herein by reference in its entirety for all purposes herein. Optionally, a polyamine chain extender that can be partially or wholly blocked is disclosed as disclosed in US Pat. No. 4,829,122. These patents prepare an aqueous polyurethane dispersion by mixing an NCO prepolymer and an at least partially blocked diamine or hydrazine chain extender in the absence of water and then adding the mixture to water. Is disclosed. Upon contact with water, the blocking agent is released and the resulting unblocked polyamine reacts with the NCO prepolymer to form a polyurethane.

  Suitable block amines and hydrazines include ketimines and aldimines formed by reacting polyamines with ketones and aldehydes, and ketazines, aldazines, ketone hydrazones and aldehyde hydrazones formed by reacting hydrazine with ketones and aldehydes. Reaction products are mentioned. The at least partially blocked polyamine has at least one blocked primary or secondary amino group, as well as at least one blocked primary or secondary amino group in the presence of water. Contains primary or secondary amino groups.

  Polyamines suitable for preparing at least partially blocked polyamines have an average functionality of 2-6, preferably 2-4 and more preferably 2-3, ie the number of amine nitrogens per molecule Have The desired functionality can be obtained by using a mixture of polyamines containing primary or secondary amino groups. The polyamine is generally an aromatic, aliphatic or cycloaliphatic amine and contains 1 to 30, preferably 2 to 15 and more preferably 2 to 10 carbon atoms. These polyamines may contain additional substituents, provided that they are not as reactive with isocyanate groups as primary or secondary amines. These identical polyamines can be partially or fully blocked polyamines.

  Preferred polyamines used for chain extension and / or crosslinking include 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexaneisophoronediamine or IPDA, bis- (4-amino-cyclohexyl) -methane, bis- (4-amino-3-methylcyclohexyl) -methane, 1,6-diaminohexane, ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine and pentaethylenehexamine.

  When a chain extender is used in the reaction with an excess of NCO groups in the prepolymer, the amount of chain extender to be used in accordance with the present invention depends on the number of terminal isocyanate groups in the prepolymer. Preferably, the ratio of terminal isocyanate groups of the prepolymer to isocyanate-reactive groups of the chain extender is from about 1.0: 0.6 to about 1.0: 1.1, more preferably about 1 on an equivalent basis. 0.0: 0.8 to about 1.0: 0.98. Any isocyanate group that is not chain extended with an amine will react with water and function as a diamine chain extender.

  Chain extension can occur prior to the addition of water to the process, but is typically performed by combining the NCO prepolymer, chain extender, water and any other ingredients with agitation. Is called.

Polyurethanes can be characterized by a variety of techniques. One technique is differential scanning calorimetry analysis. This method is characterized by the thermal conversion of polyurethane. The initial T _g is a characteristic property of polyurethane.

  Suitable polyurethane additives will form dispersions when mixed with water or in the aqueous solution from which the polyurethane is prepared. The particle size of the polyurethane additive is typically in the range of about 30 to about 100,000 nm. A preferred range for polyurethane additives for inkjet inks is from about 30 to about 350 nm.

  It is possible to add other monomers and / or oligomers that are not chemically involved in the polyurethane synthesis step. This addition can be made anywhere in the synthesis cycle as long as it does not interfere with the polyurethane synthesis. A specific example of a compatible oligomer / monomer is styrene allyl alcohol.

  In order to obtain a stable polyurethane dispersion, sufficient that the resulting polyurethane remains stably dispersed in an aqueous medium when combined with any hydrophilic ethylene oxide unit and any external emulsifier. A good amount of acid groups must be neutralized. Generally, at least about 75%, preferably at least about 90% of the acid groups are neutralized to the corresponding carboxylic acid group. A preferred dispersion stabilizing means for the polyurethane additive is a carboxylate group without ethylene oxide substituents and external emulsifiers.

  Suitable neutralizing agents for converting acid groups to bases before, during or after incorporation into the NCO prepolymer include tertiary amines, alkali metal cations and ammonia. Examples of these neutralizing agents are disclosed in US Pat. No. 4,501,852 and US Pat. No. 4,701,480, both of which are incorporated herein by reference in their entirety. The entire contents thereof are incorporated as described herein for purposes.

  Neutralization may take place at any point in the process. A typical approach involves at least some neutralization of the prepolymer and then its chain extension in water in the presence of additional neutralizing agents.

  Preferred polyurethanes in the additive are selected from a) urea terminated polyurethanes and b) crosslinked polyurethanes.

Urea-terminated polyurethane additive The optional polyurethane ink additive can be a urea-terminated polyurethane of general structure (I).

（Ｒ₁＝ジイソシアネートからのアルキル、置換アルキル、置換アルキル／アリールであり、
Ｒ₂＝ジオールからのアルキル、置換／分岐アルキルであり、
Ｒ₃＝水素；アルキル；アミン末端封止基からの非イソシアネート反応性置換アルキル、イソシアネート反応性置換アルキル、または分岐アルキルであり；
Ｒ₄＝水素；アルキル；アミン末端封止基からの非イソシアネート反応性置換アルキル、イソシアネート反応性置換アルキル、または分岐アルキルであり；
イソシアネート反応性基はヒドロキシル、カルボキシル、メルカプトまたはアミドから選択され；
ｎ＝２〜３０であり；
ならびに、Ｒ₂＝Ｚ₁、Ｚ₂またはＺ₃であり、かつ、少なくとも１つのＺ₁またはＺ₃および少なくとも１つのＺ₂がポリウレタン組成物中に存在していなければならず；

(R ₁ = alkyl from diisocyanate, substituted alkyl, substituted alkyl / aryl,
R ₂ = alkyl from diol, substituted / branched alkyl,
R ₃ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
R ₄ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
The isocyanate-reactive group is selected from hydroxyl, carboxyl, mercapto or amide;
n = 2-30;
And R ₂ = Z ₁ , Z ₂ or Z ₃ and at least one Z ₁ or Z ₃ and at least one Z ₂ must be present in the polyurethane composition;

ｐは１以上であり、
ｐ＝１である場合、ｍは２以上〜約３６であり、
ｐ＝２以上である場合、ｍは２以上〜約１２であり；
Ｒ₅、Ｒ₆＝水素、アルキル、置換アルキル、アリールであり；ここで、Ｒ₅はＲ₅およびＲ₆置換メチレン基の各々と同一または異なっており、Ｒ₅とＲ₅またはＲ₆とは結合して環構造を形成していることが可能であり；
Ｚ₂は、イオン基で置換されたジオールであり；
Ｚ₃は、ポリエステルジオール、ポリカーボネートジオール、ポリエステルカーボネートジオールおよびポリアクリレートジオールから選択される；）
ここで、尿素末端ポリウレタンインク添加剤の尿素含有量はポリウレタン樹脂の少なくとも２重量％である。

p is 1 or more,
when p = 1, m is from 2 to about 36;
when p = 2 or more, m is 2 or more to about 12;
R ₅ , R ₆ = hydrogen, alkyl, substituted alkyl, aryl; where R ₅ is the same as or different from each of the R ₅ and R ₆ substituted methylene groups, and R ₅ and R ₅ or R ₆ are They can be joined to form a ring structure;
Z ₂ is a diol substituted with an ionic group;
Z ₃ is selected from polyester diol, polycarbonate diol, polyester carbonate diol and polyacrylate diol;)
Here, the urea content of the urea terminated polyurethane ink additive is at least 2% by weight of the polyurethane resin.

  Structure I shows a urea terminated polyurethane ink additive, and Structure II shows the diols and polyether diols that are building blocks for Structure I. When p is 1, the diol is a primary isocyanate-reactive group, and when p is greater than 1, the diol is characterized as a polyether diol.

The first step in the preparation is:
(A) (i) at least one polyether diol Z ₁ or Z ₃ component comprising a diol, (ii) at least one polyisocyanate component comprising a diisocyanate, and (iii) at least one containing an ionic group Z ₂ Providing a reactant comprising at least one hydrophilic reactant comprising a species of isocyanate-reactive formulation component;
(B) reacting (i), (ii) and (iii) in the presence of a hydratable organic solvent to form an isocyanate functional polyurethane prepolymer;
(C) adding water to form an aqueous dispersion; and (d) prior to, simultaneously with, or after step (c), the isocyanate-functional prepolymer is converted to a primary or secondary amine. A method of preparing an aqueous dispersion of an aqueous polyurethane composition of urea-terminated polyurethane comprising the step of chain-end capping with

  The chain end capped amine is typically added in an amount that reacts with substantially all of the remaining isocyanate functionality prior to the addition of water. The chain end capped amine is preferably a nonionic secondary amine.

  When the hydrophilic reactant contains an ionized group, upon addition of water (step (c)), the ionized group is an acid or base (depending on the type of ionized group) and the polyurethane is stably dispersed. May be ionized by adding in an amount such that it is possible. This neutralization can be performed at any convenient time during the preparation of the polyurethane.

  Preferably, at some point during the reaction (generally after addition of water and after chain extension), the organic solvent is substantially removed under reduced pressure to produce a dispersion essentially free of solvent. The

After the polyurethane dispersion is prepared, it is used in dispersing the particles by known dispersion techniques. An important property of the polyurethane ink additive is a diol and / or at least one polyether diol, Z ₁ or Z ₃ , and a monofunctional amine that provides urea end-capping.

  It should be understood that the process used to prepare the polyurethane generally results in a urea terminated polyurethane polymer of the above structure present in the final product. However, the final product is typically partly a urea terminated polyurethane polymer as described above, the other part being a normal distribution of other polymer products, and containing unreacted monomers in various ratios. It is understood that this may be a mixture of possible products. The resulting polymer heterogeneity will depend on the selected reactants and the selected reactant conditions, as will be apparent to those skilled in the art.

Diol and polyether diol component of urea end-capped polyurethane ink additive The optional diol component {Z1} has α, ω having at least 2 methylene groups and no more than 30 methylene groups (m = 2 to about 30). Can be based on either a dialcohol or diol (p = 1) or a polyether diol (p is greater than 1) having 2-12 methylene groups (m = 2 to about 12). is there. The diols and polyether diols can be used individually or in a mixture. The amount of diol: polyether diol ranges from 0: 100 to 100: 0. The preferred number of methylene groups for diols and polyether diols is at least 3 but less than about 30.

  In one embodiment, the diols and / or polyether diols shown in structure (II) are other oligomeric systems such as, for example, polyols, polyamines, polythiols, polythioamines, polyhydroxythiols and polyhydroxylamines and / or Or it may be blended with a polymeric polyfunctional isocyanate-reactive compound. When blended, it is possible to use a bifunctional component, and more preferably one or more diols including, for example, polyether diols, polyester diols, polycarbonate diols, polyacrylate diols, polyolefin diols and silicone diols. preferable.

  When p is greater than 1, the polyether diols shown in structure (II) are oligomers and polymers in which at least 50% of the repeating units have 2 to 12 methylene groups in the ether chemical group. More preferably, about 75% to 100%, even more preferably about 90% to 100%, and even more preferably about 99% to 100% of the repeating units comprise 2 to 12 methylene groups in the ether chemical group. (In structure (II), m = 3 to 12). The preferred number of methylene groups is 3 or 4. The polyether diols shown in structure (II) can be prepared by polycondensation of monomers containing α, ω diols where m = 2-12. Therefore, a polymer or copolymer containing the structural bonds shown above is provided. As indicated above, at least 50% of the repeat units are 2-12 methylene ether units.

Oligomers and polymers based on the polyether diols shown in structure (II), where p is greater than 1 are used as repeat units from 2 to about 50 poly (s) shown in structure (II). It has an ether diol, more preferably from about 5 to about 20 polyether diols shown in structure (II). Here, p represents the number of repeating groups. R ₅ and R ₆ is hydrogen, alkyl, substituted alkyl, aryl; wherein, R _5, R ₅ and R ₆ each and are the same or different substituents methylene group, and wherein the R ₅ It is possible that R ₅ or R ₆ is bonded to form a cyclic structure. As described below, the substituted alkyl preferably does not contain an isocyanate-reactive group except where a limited amount of trihydric alcohol can be tolerated. Usually, the substituted alkyl is intended to be inert during polyurethane preparation.

  In addition to 3-12 methylene ether units, smaller amounts of other units may be present, such as other polyalkylene ether repeat units derived from ethylene oxide and propylene oxide. The amount of ethylene glycol and 1.2-propylene glycol derived from epoxides such as ethylene oxide, propylene oxide, butylene oxide and the like is limited to less than 10% of the total weight of the polyether diol.

A preferred polyether diol is derived from 1,3-propanediol (PO3G). The employed PO3G can be obtained by any of a variety of well known chemical or biochemical transformation pathways. Preferably, 1,3-propanediol is obtained biochemically from renewable raw materials ("biologically derived" 1,3-propanediol). A description of this biochemically obtained 1,3-propanediol can be found in a co-filed U.S. patent application (Applicant's identification number is CL3026), the disclosure of which is herein The entire contents of all references are incorporated by reference as if set forth herein.
For the diol of structure (II) (p = 1), the biochemically derived material described above is the preferred 1,3-propanediol.

  The starting material to form the diol will depend on the desired structure II polyether diol (p is greater than 1), availability of starting material, catalyst, equipment, etc. , 12-diol reactant ". "1,2-1,12-diol reactant" means 1,2-1,12-diol and oligomer of 1,3-1,12-diol, preferably having a degree of polymerization of 2-50 And prepolymers, and mixtures thereof. In some cases, it may be desirable to use a low molecular weight oligomer, if available, up to 10% or more. Preferably, therefore, the starting material comprises 1,3-1,12-diol, and dimers and trimers thereof. Particularly preferred starting materials are about 90% by weight or more of 1,3-1,12-diol, and more preferably 99% by weight or more of 1,3-1,12-diol based on the weight of the reactants. Consists of 3-1,12-diol.

  As indicated above, the polyether diol shown in structure (II) (p is greater than 1) can be added to 3-12 methylene ether units to reduce the amount of other poly An alkylene ether repeating unit may be contained. The monomer used to prepare the poly (3-12) methylene ether glycol is therefore, in addition to the 1,3-propanediol reactant, 50% or less (preferably about 20% or less, more preferably about 10%). Up to about 2% by weight, and even more preferably up to about 2% by weight comonomer diol. Suitable comonomer diols for use in this process include aliphatic diols such as ethylene glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1 , 10-decanediol, 1,12-dodecanediol, 3,3,4,4,5,5-hexafluoro-1,5-pentanediol, 2,2,3,3,4,4,5,5 -Octafluoro-1,6-hexanediol and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-hexadecafluoro-1, 12-dodecanediol; cycloaliphatic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and isosorbide; and polyhydroxy compounds such as Glycerol, trimethylol propane, and pentaerythritol. The polyether diol shown in structure (II) useful in the practice of the present invention is described in US Pat. No. 6,608,168, the disclosure of which is hereby incorporated by reference in its entirety for all purposes. Small amounts of other recurring units such as, for example, aliphatic or aromatic diacids or diesters, such as those described in US Pat. This type of polyether diol, shown in structure (II), may also be referred to as “random polymethylene ether ester”, terephthalic acid, isophthalic acid, bibenzoic acid, naphthalic acid, bis (p-carboxyphenyl) methane 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-sulfonyldibenzoic acid, p- (hydroxyethoxy) benzoic acid, and combinations thereof, and 1,3-1,12-diol reactant and about 10 to about 0.1 mol% of its aliphatic or aromatic diacid, such as dimethyl terephthalate, bibenzoate, isophthalate, naphthalate and phthalate; and combinations thereof Or can be prepared by polycondensation of esters It is a function. Of these, terephthalic acid, dimethyl terephthalate and dimethyl isophthalate are preferred.

When a polyether diol shown in structure (II) (p is greater than 1) is used for the diols of the present invention, it is about 200 to about 5000, and more preferably about 240 to about 3600. It is preferable to have a number average molecular weight (M _n ) within the range of A blend of polyether diols shown in structure (II) can also be used. For example, polyether diols shown in structure (II) can include higher molecular weight and lower molecular weight blends, preferably higher molecular weights shown in structure (II). The polyether diol has a number average molecular weight of about 1000 to about 5000, and the lower molecular weight polyether diol shown in structure (II) has a number average molecular weight of about 200 to about 750. Blended, M _n of the polyether diol shown in structure (II) is further, it would be preferably in the range of from about 250 to about 3600. The polyether diols shown in structure (II) preferred for use herein are typically preferably from about 1.0 to about 2.2, more preferably from about 1.2 to about 2.2. , And even more preferably a polydisperse polymer having a polydispersity (ie M _w / M _n ) of from about 1.5 to about 2.1. Polydispersity can be adjusted by using a blend of polyether diols shown in structure (II).

  The polyether diol shown in structure (II) for use in the present invention preferably has a lightness of less than about 100 APHA, and more preferably less than about 50 APHA.

Other Isocyanate-Reactive Components As indicated above, the polyether diol shown in structure (II) can be blended with other polyfunctional isocyanate-reactive components, particularly oligomeric and / or polymeric polyols. Can be done.

  Other suitable diols contain at least two hydroxyl groups and preferably have a molecular weight of about 60 to about 6000. Of these, other polymeric diols are optimally defined by number average molecular weights, ranging from about 200 to about 6000, preferably from about 400 to about 3000, and more preferably from about 600 to about 2500. It is possible that there is. The molecular weight can be measured by hydroxyl group analysis (OH number).

  Examples of polymeric polyols include polyesters, polyethers, polycarbonates, polyacetals, poly (meth) acrylates, polyesteramides, polythioethers, and polyester-polycarbonates where both ester and carbonate linkages are found in the same polymer. Of the mixed polymer. Combinations of these polymers can also be used. For example, polyester polyols and poly (meth) acrylate polyols can be used in the same polyurethane synthesis.

  Suitable polyester polyols include reaction products of polyvalent, preferably dihydric alcohols, to which trihydric alcohols can be optionally added, and polybasic (preferably dibasic) carboxylic acids. Trihydric alcohols are limited to about 2 wt% or less so that some degree of branching can occur but no significant crosslinking occurs, and moderate branching of NCO prepolymer or polyurethane is desired. Can be used. Instead of these polycarboxylic acids, the corresponding carboxylic acid anhydrides or polycarboxylic acid esters of lower alcohols or mixtures thereof can be used for the preparation of the polyesters.

  The polycarboxylic acid can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic or mixtures thereof, which can be, for example, substituted by halogen atoms and / or unsaturated. Also good. The following are listed as examples: succinic acid; adipic acid; suberic acid; azelaic acid; sebacic acid; 1,12-dodecyl diacid; phthalic acid; isophthalic acid; trimellitic acid; phthalic anhydride; Hexahydrophthalic anhydride; tetrachlorophthalic anhydride; endomethylenetetrahydrophthalic anhydride; glutaric anhydride; maleic acid; maleic anhydride; fumaric acid; monomeric fatty acids may be mixed Dimer and trimer fatty acids such as oleic acid; dimethyl terephthalate and bis-glycol terephthalate.

  Preferred polyester diols for blending with the polyol shown in structure (II) are hydroxyl-terminated poly (butylene adipate), poly (butylene succinate), poly (ethylene adipate), poly (1,2-propylene) Adipate), poly (trimethylene adipate), poly (trimethylene succinic acid), polylactic acid ester diol and polycaprolactone diol. Other hydroxyl end-capped polyester diols are copolyethers containing repeat units derived from diols and sulfonated dicarboxylic acids, and are disclosed in US Pat. No. 6,316,586, the disclosure of which is hereby incorporated by reference for all purposes. The entire contents of which are incorporated herein by reference). A preferred sulfonated dicarboxylic acid is 5-sulfo-isophthalic acid, and a preferred diol is 1,3-propanediol.

  Suitable polyether polyols are known by reaction of starting compounds containing reactive hydrogen atoms with alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin, or mixtures thereof. It is obtained in the form of It is preferred that the polyether does not contain more than about 10% by weight of ethylene oxide units. More preferably, polyethers obtained without addition of ethylene oxide are used. Suitable starting compounds containing reactive hydrogen atoms include the polyhydric alcohols described for the preparation of polyester polyols, as well as water, methanol, ethanol, 1,2,6-hexanetriol, 1 , 2,4-butanetriol, trimethylolethane, pentaerythritol, mannitol, sorbitol, methylglycoside, sucrose, phenol, isononylphenol, resorcinol, hydroquinone, 1,1,1- and 1,1,2-tris- (hydroxy Phenyl) -ethane, dimethylolpropionic acid or dimethylolbutanoic acid.

  Polyethers obtained by reaction of starting compounds containing amine compounds can also be used. Examples of these polyethers, as well as suitable polyhydroxypolyacetals, polyhydroxypolyacrylates, polyhydroxypolyesteramides, polyhydroxypolyamides and polyhydroxypolythioethers are described in US Pat. No. 4,701,480, the disclosure of which is herein incorporated by reference. The entire contents of which are incorporated herein by reference for all purposes).

  Polycarbonates containing hydroxyl groups include propanediol- (1,3), butanediol- (1,4) and / or hexanediol- (1,6), diethylene glycol, triethylene glycol or tetraethylene glycol, higher polyethers Known per se, such as products obtained from the reaction of diols such as diols with diaryl carbonates such as phosgene, diphenyl carbonate, dialkyl carbonates such as diethyl carbonate, or cyclic carbonates such as ethylene or propylene carbonate The thing which is is mentioned. Also suitable are polyester carbonates obtained from the polyesters or polylactones mentioned above and phosgene, diaryl carbonates, dialkyl carbonates or cyclic carbonates.

  The polycarbonate diol for blending is preferably selected from the group consisting of polyethylene carbonate diol, polytrimethylene carbonate diol, polybutylene carbonate diol and oil hexylene carbonate.

  Examples of the poly (meth) acrylate containing a hydroxyl group include those commonly used in the technical field of addition polymerization such as cationic, anionic and radical polymerization. α-ω diols are examples. An example of these types of diols are those prepared by “living” or “controlled” or chain transfer polymerization processes that allow the placement of one hydroxyl group at or near the end of the polymer. U.S. Pat. No. 6,248,839 and U.S. Pat. No. 5,990,245, the disclosures of which are incorporated herein by reference in their entirety for all purposes. An example of a procedure for forming a terminal diol is provided. Other di-NCO reactive poly (meth) acrylate terminated polymers can be used. An example is an end group other than hydroxyl, such as amino or thiol, and mixed end groups with hydroxyl may also be included.

Any set of diols, above are shown as Z _3, it is a polyester diol, polycarbonate diol, polyester carbonate diols and polyacrylate diols. These Z ₃ diols are always used in combination with Z _{2 in} order to be able to achieve the ionic properties of polyurethane.

  Polyolefin diols are available from Shell as KRATON LIQUID L and from Mitsubishi Chemical Corporation as POLYTAIL H.

  Silicone glycols are well known and representative examples are described in US Pat. No. 4,647,643, the disclosure of which is hereby incorporated in its entirety for all purposes by reference herein. Incorporated as a thing.

  Other optional compounds for preparing the NCO prepolymer include low molecular weight, at least bifunctional NCO-reactive compounds having an average molecular weight of about 400 or less. Examples include dihydric and higher functional alcohols already described for the preparation of polyester polyols and polyether polyols.

  Preferably, in addition to the above-mentioned components that are difunctional in isocyanate polyaddition reactions, commonly known monofunctionalities in polyurethane chemistry such as trimethylolpropane or 4-isocyanatomethyl-1,8-octamethylene diisocyanate A small portion of the functional moiety and even trifunctional and higher functional components may be used in cases where NCO prepolymer or polyurethane branching is desired.

  However, it is preferred that the NCO functional prepolymer is substantially linear, which can be achieved by maintaining the average functionality of the prepolymer starting component at 2.1 or lower.

  Similar NCO-reactive materials can be used as described for hydroxy-containing compounds and polymers, but contain other NCO-reactive groups. Examples would be dithiols, diamines, thioamines, and even hydroxythiols and hydroxylamines. These can be any of the compounds or polymers having the molecular weight or number average molecular weight described for the polyol.

Chain End Capping Reactor for Urea End-capped Polyurethane Additives End-capping agents are primary or secondary monoamines added to form urea end-capping. In structure (I), the end-capping agent is shown as the R ₃ (R ₄ ) N-substituent on the polyurethane. Substitution patterns for R ₃ and R ₄ include hydrogen, alkyl, substituted / branched alkyl, isocyanate reactivity, where the substituents are hydroxyl, carboxyl, mercapto, amide, and primary or secondary amine It can be an isocyanate-reactive group selected from others with inferior isocyanate reactivity. At least one of R ₃ and R ₄ must be other than hydrogen. R ₃ and R ₄ may be connected to form a cyclic compound. Cyclic compounds can also have oxygen in the cyclic compound.

  The amount of chain terminator utilized should be approximately equivalent to the unreacted isocyanate groups in the prepolymer, and the ratio of active hydrogen from amines in the chain terminator to isocyanate groups in the prepolymer is on an equivalent basis. Preferably from about 1.0: 1 to about 1.2: 1, more preferably from about 1.0: 1.1 to about 1.1: 1, and even more preferably from about 1.0: 1.05. To about 1.1: 1. Any isocyanate group that is not end-capped with an amine can react with other isocyanate-reactive functional groups and water, but the ratio of chain end capping to isocyanate groups ensures that the urea end capping is Selected to be. Amine end-capping of the polyurethane is avoided by the choice and amount of chain end-capping agent, resulting in a urea-terminated polyurethane with improved molecular weight control and improved properties as a particle dispersant.

  Aliphatic primary or secondary monoamines are preferred. Examples of monoamines useful as chain terminators include, but are not limited to, butylamine, hexylamine, 2-ethylhexylamine, dodecylamine, diisopropanolamine, stearylamine, dibutylamine, dinonylamine, bis (2-ethylhexyl) Amine, diethylamine, bis (methoxyethyl) amine, N-methylstearylamine, diethanolamine and N-methylaniline. Other nonionic hydrophilic secondary amines include heterocyclic structures such as morpholine and similar secondary nitrogen heterocycles. A preferred isocyanate-reactive chain terminator is bis (methoxyethyl) amine (BMEA). Bis (methoxyethyl) amines are part of a preferred class of urea end-capped reactants where the substituents are non-reactive in isocyanate chemistry but are nonionic hydrophilic groups. This nonionic hydrophilic group provides a more water-compatible urea-terminated polyether diol polyurethane.

  Any primary or secondary monoamine substituted with a group with poor isocyanate reactivity can be used as a chain terminator. Groups that are less isocyanate reactive can be hydroxyl, carboxyl, amide and mercapto. Examples of monoamines useful as chain terminators include, but are not limited to, monoethanolamine, 3-amino-1-propanol, isopropanolamine, N-ethylethanolamine, diisopropanolamine, 6-aminocaproic acid, 8-amino Examples include caprylic acid, 3-aminoadipic acid, and lysine. Chain end capping agents may include those having two groups with poor isocyanate reactivity, such as glutamine. A preferred isocyanate-reactive chain terminator is diethanolamine. Diethanolamine is part of a preferred class of urea end-capped reactants, which are hydroxyl functional groups whose substituents can provide improved pigment wettability. The relative reactivity of the group with less amine to isocyanate reactivity, as well as the molar ratio of NCO to chain-capped amine, results in a urea terminated polyurethane.

The urea content of the urea terminated polyurethane in weight percent of the polyurethane is determined by dividing the mass of the chain terminator by the sum of the other polyurethane components including the chain end capping agent. The urea content is about 2% to about 14% by weight. The urea content is preferably from about 2.5% to about 10.5% by weight. 2% by weight occurs when the polyether diol used is large, for example _Mn is greater than about 4000 and / or the molecular weight of the isocyanate is high.

Polyisocyanate component Suitable polyisocyanates, preferably diisocyanates, are mentioned above.

Ionic Reactants Hydrophilic reactants contain ionic and / or ionizable groups (potentially ionic groups). Preferably, these reactants will contain one or two, more preferably two isocyanate-reactive groups, as well as at least one ionic or ionizable group. In the structural representation of the urea terminated polyether polyurethane described herein, the reactants containing an ionic group is represented as Z _2.

Examples of ionic dispersing groups include carboxylate groups (—COOM), phosphate groups (—OPO ₃ M ₂ ), phosphonic acid groups (—PO ₃ M ₂ ), sulfonate groups (—SO ₃ M), fourth A quaternary ammonium group (—NR ₃ Y, where Y is a monovalent anion such as chlorine or hydroxyl), or any other effective ionic group. M is a cation such as a monovalent metal ion (eg, NA ⁺ , K ⁺ , LI ^+, etc.), H ⁺ , NR ₄ ^+, etc., and each R is independently alkyl, aralkyl, aryl, or hydrogen It is possible that there is. These ionic dispersing groups are typically located in side groups from the polyurethane backbone.

Ionizable group is usually (such as carboxyl -COOH) acid form or base form (primary, secondary or tertiary amines -NH _2, -NRH, or -NR _2, etc.) except where the ion Corresponds to the group. The ionizable groups are those that are readily converted to their ionic form during the dispersion / polymer preparation process, as discussed below.

  The ionic or potentially ionic groups are urea terminated in an amount that provides sufficient ionic group content (with neutralization if necessary) to impart the polyurethane with dispersibility in an aqueous medium. Chemically incorporated into polyurethane. Typical ionic group content ranges from about 10 to about 210 milliequivalents (meq) or less, preferably from about 20 to about 140 meq / 100 g polyurethane, and most preferably less than about 90 meq / 100 g urea terminated polyurethane. Let's go.

  Suitable compounds for incorporating these groups include: (1) monoisocyanates and / or diisocyanates containing ionic and / or ionizable groups, and (2) isocyanate reactive groups and ionic and / or ionizable groups. The compound containing both is mentioned. In the context of this disclosure, the term “isocyanate-reactive group” is meant to include groups that react with isocyanates, which are well known to those skilled in the relevant art, preferably hydroxyl, primary amino groups and secondary groups. An amino group.

  Examples of isocyanates containing ionic or potentially ionic groups are sulfonated toluene diisocyanate and sulfonated diphenylmethane diisocyanate.

  For compounds containing isocyanate-reactive groups and ionic or potentially ionic groups, the isocyanate-reactive groups are typically amino groups and hydroxyl groups. The latent ionic group or its corresponding ionic group is preferably an anionic group, but may be cationic or anionic. Preferred examples of anionic groups include carboxylate and sulfonate groups. Preferred examples of the cationic group include a quaternary ammonium group and a sulfonium base.

  Neutralizing agents for converting ionizable groups to ionic groups are described in the literature already incorporated and are also described later in this specification. In the context of the present invention, the term “neutralizing agent” is meant to encompass all types of agents that are useful for converting ionizable groups to more hydrophilic ionic (salt) groups.

  In the case of ionic group substitution, this group can be a carboxylic acid group, a carboxylate group, a sulfonic acid group, a sulfonic acid group, a phosphoric acid group and a phosphonic acid group, and the acid salt is the corresponding acid. The groups are formed by neutralization either before, during or after formation of the NCO prepolymer, preferably after formation of the NCO prepolymer.

  Suitable compounds for incorporating carboxyl groups are described in US Pat. No. 3,479,310, US Pat. No. 4,108,814 and US Pat. No. 4,408,008. Which are hereby incorporated by reference herein in their entirety for all purposes. Neutralizing agents for converting carboxylic acid groups to carboxylic acid groups are described in the aforementioned US patents and are also described later in this specification. In the context of the present invention, the term “neutralizing agent” is meant to encompass all types of agents useful for converting carboxylic acid groups to hydrophilic carboxylic acid groups.

Preferred carboxylic acid group-containing compounds have the structure (HO) _j Q (COOH) _k , where Q represents a linear or branched hydrocarbon radical containing 1 to 12 carbon atoms, j is 1 or 2, preferably 2, and k is 1 to 3, preferably 1 or 2, more preferably 1).

  Examples of these hydroxy-carboxylic acids include citric acid, tartaric acid and hydroxypivalic acid. Particularly preferred acids are those described above (where j = 2 and k = 1). These dihydroxyalkanoic acids are described in U.S. Pat. No. 3,420,054, which is incorporated herein by reference in its entirety for all purposes. Particularly preferred dihydroxyalkanoic acids are structural formulas:

（式中、Ｑ’は水素、または、１〜８個の炭素原子を含有するアルキル基である）
によって表されるα，α−ジメチロールアルカン酸である。もっとも好ましい化合物は、α，α−ジメチロールプロピオン酸（すなわち、上記式において、Ｑ’がメチルである）である。

(Wherein Q ′ is hydrogen or an alkyl group containing 1 to 8 carbon atoms)
The α, α-dimethylolalkanoic acid represented by The most preferred compound is α, α-dimethylolpropionic acid (ie, Q ′ is methyl in the above formula).

  When the ionic stabilizing group is an acid, the acid group is at least about 6, preferably at least about 10 milligrams KOH, and even more preferably 20 per 1.0 gram of polyurethane per 1.0 gram of polyurethane. Incorporated in an amount sufficient to provide the acid group content of the urea-terminated polyurethane, known as the acid number by the skilled person (mg KOH / 1 gram solid polymer) of milligram KOH, the upper limit of acid number (AN) is about 120 , Preferably about 90.

  The urea terminated polyurethane ink additive has a number average molecular weight of about 2000 to about 30,000. Preferably, the molecular weight is about 3000-20000. As described herein, these urea terminated polyurethanes can also function as polymeric dispersants. In practice, those having a formulation that, when used with a dispersant, result in a pigment dispersion that passes the salt stability test set forth above can be considered an ISD dispersant.

Crosslinked polyurethane ink additive The optional polyurethane ink additive can be a crosslinked polyurethane. The means for achieving polyurethane cross-linking generally depends on at least one component of the polyurethane (starting material and / or intermediate) having three or more functional reactive sites. Reaction of each of the three (or more) reactive sites will result in a crosslinked polyurethane (three-dimensional matrix). If only two reactive sites are available for each reactive component, only linear (possibly even high molecular weight) polyurethane can be produced. Examples of cross-linking techniques include, but are not limited to:
An isocyanate-reactive moiety having at least 3 reactive groups, such as a polyfunctional amine or polyol;
The isocyanate has at least 3 isocyanate groups;
Via a reaction other than the isocyanate reaction, for example with at least three reactive sites in the prepolymer chain, which can react with an aminotrialkoxysilane;
Addition of a reactive component having at least three reactive sites to the polyurethane prior to its use in inkjet ink preparation, such as a trifunctional epoxy crosslinker;
Addition of a water-dispersible crosslinker having an oxazoline functional group;
Synthesis of polyurethanes with carbonyl functionality, followed by addition of dihydrazide compounds;
And any combination of these crosslinking methods and other crosslinking means known to those skilled in the relevant art.

  It will also be appreciated that these cross-linking components may be only a minor part of the total reactive functional groups added to the polyurethane. For example, if a polyfunctional amine is added, monofunctional and difunctional amines can also be present in the reaction with the isocyanate. The polyfunctional amine can be a minor part of the amine.

  Crosslinking preferably occurs during the preparation of the polyurethane. The preferred time for crosslinking in the polyurethane reaction sequence will be during or after the inversion step. That is, crosslinking preferably occurs during or immediately after the addition of water to the polyurethane preparation mixture. Inversion is the point at which enough water is added to convert the polyurethane to its stable dispersed aqueous form. Most preferably, crosslinking occurs after inversion. Moreover, it is preferred that substantially all crosslinking of the polyurethane is complete prior to incorporation into the ink formulation.

  Alternatively, crosslinking can occur during the initial formation of urethane bonds if the isocyanate or isocyanate-reactive group has three or more groups capable of reacting. If crosslinking occurs at this early stage, it should not be crosslinked to the extent that it results in gel formation. Excessive crosslinking at this stage will prevent the formation of a stable polyurethane dispersion.

  The amount of polyurethane cross-linking to achieve the desired ink-jet ink for ink-jet printing can vary over a wide range. Without being bound by theory, the amount of crosslinking depends on the polyurethane composition, the overall sequence of reaction conditions utilized to form the polyurethane, and other factors known to those skilled in the art.

  Preferred crosslinking is performed with a prepolymer having an excess of NCO reactive sites, followed by reaction with an amine in which at least some of the amines are tri- or higher. After inversion of the rich NCO-prepolymer, an amine is added and reacted with an excess of NCO. In addition to the trisubstituted amine, monoamines and diamines may be present. Amines can be primary and secondary amines. A preferred amine mixture for crosslinking is a mixture of diethylenetriamine and tetraethylenetriamine.

  Based on the techniques described herein, those skilled in the art will determine, through routine experimentation, the cross-linking required for a particular type of polyurethane to obtain an effective inkjet ink for textiles and other substrates. Is possible. Moreover, as mentioned above, these inks can also be used on plain paper, photographic paper, slide films, vinyl and other printable substrates.

  The amount of crosslinking can be measured by a standard tetrahydrofuran insoluble test. For purposes of definition herein, the tetrahydrofuran (THF) insoluble content of the polyurethane ink additive is obtained by mixing 1 gram of polyurethane ink additive and 30 grams of THF into a pre-weighed centrifuge tube. It is measured. After centrifuging the solution at 17,000 rpm for 2 hours, the top liquid layer is poured out, leaving the bottom undissolved gel. Centrifuge tubes containing undissolved gel are reweighed after the tubes are placed in an oven and dried at 110 ° C. for 2 hours.

  % THF insoluble content of polyurethane = (weight of tube and undissolved gel−weight of tube) / (sample weight × polyurethane solid%)

  The upper limit of crosslinking is related to the ability to form stable aqueous polyurethane dispersions. If a highly cross-linked polyurethane has appropriate ionic or nonionic functional groups that are stable when converted to water, the cross-linking level will result in improved textile inkjet inks. . The emulsion / dispersion stability of the crosslinked polyurethane can be improved by added dispersants or emulsifiers. The upper limit of crosslinking as measured by the THF insoluble content test is about 90%. Alternatively, the upper limit is about 50%.

  The lower limit of crosslinking in the polyurethane ink additive is about 1% or more, preferably about 4% or more as measured by a THF insoluble matter test.

  An alternative way to achieve an effective amount of crosslinking in the polyurethane is to select polyurethanes with crosslinkable sites and then crosslink these sites via self-crosslinking and / or via added crosslinking agents. It is to let you. Examples of self-crosslinking functional groups include, for example, silyl functional groups (self-condensing) that are available from certain starting materials as described above, and polyurethanes such as epoxy / hydroxyl, epoxy / acid and isocyanate / hydroxyl. A combination of incorporated reactive functional groups may be mentioned. Examples of polyurethanes and complementary crosslinking agents include: (1) polyurethanes, isocyanate reactive sites (such as hydroxyl and / or amine groups) and isocyanate crosslinking reactants, and 2) polyurethanes, unreacted isocyanate groups and isocyanates. -Reactive crosslinking reactants (for example containing hydroxyl and / or amine groups). Complementary reactants can be added to the polyurethane so that crosslinking occurs prior to its incorporation into the ink formulation. Crosslinking should preferably be substantially complete prior to incorporation of the additive into the ink formulation. The crosslinked polyurethane preferably has from about 1% to about 50% crosslinking as measured by a THF insoluble matter test.

  Combinations of two or more polyurethane additives, one or more of which are crosslinked, can also be utilized in the formulation of the ink.

  Further details regarding the preparation of polyurethane dispersions can be found in the literature already incorporated.

  The polyurethane ink additive is generally a stable aqueous dispersion of polyurethane particles having a solids content of about 60 wt% or less, preferably about 15 to about 60 wt%, and most preferably about 30 to about 45 wt%. is there.

  However, it is always possible to dilute the dispersion to any minimum solids content desired.

Pigments A wide variety of organic and inorganic pigments can be selected alone or in combination to form ISDs and inks. The term “pigment” as used herein means an insoluble colorant and can include disperse dyes. The pigment particles should be small enough to allow free flow in ink inkjet printing devices, particularly discharge nozzles having a diameter typically in the range of about 10 microns to about 50 microns. Particle size also has an effect on pigment dispersion stability, which is important throughout the life of the ink. The Brownian motion of the fine particles helps to prevent particle aggregation. It is also desirable to use small particles for maximum color strength and gloss. Useful particle size ranges are typically from about 0.005 microns to about 15 microns. Preferably, the pigment particle size should range from about 0.005 to about 5 microns and most preferably from about 0.005 to about 1 micron. The average particle size measured by the dynamic light scattering method is less than about 500 nm, preferably less than about 300 nm.

  The selected pigment can be used in dry or wet form. For example, pigments are usually produced in aqueous media, and the resulting pigments are obtained as water wet presscakes. In the presscake form, the pigment is not agglomerated to the extent that it is in the dry form. Therefore, water-wet presscake pigments do not require as much deagglomeration in the ink preparation process as dry-form pigments. Representative commercial dry pigments are listed in US Pat. No. 5,085,698, the disclosure of which is incorporated herein by reference in its entirety for all purposes. Is done.

  In the case of organic pigments, the ink contains about 30 wt% or less, preferably from about 0.1 to about 25 wt%, and more preferably from about 0.25 to about 10 wt% pigment, based on the total ink weight. Can do. If an inorganic pigment is selected, the ink will tend to contain a greater weight percent of the pigment than an equivalent ink using an organic pigment, and in some cases, the inorganic pigment will generally be , Having a specific gravity greater than the organic pigment, can be as much as about 75%.

  The ISD polymer dispersant is preferably in the range of about 0.1 to about 20% by weight, more preferably in the range of about 0.2 to about 10% by weight, and even more preferably, based on the weight of the total ink composition. It is present in the range of about 0.25% to about 5% by weight.

Ink Preparation and Properties The inks of the present invention are prepared by methods commonly used for the preparation of inkjet inks. The ISD pigment dispersion and polyurethane ink additive are mixed together with other additives to obtain an inkjet ink. It is preferred to add the formulation ingredients to the ISD pigment dispersion while stirring. The other formulation ingredients can be added in any convenient order.

  The dispersant used can also be used as an ink additive. That is, a polyurethane similar or identical to the structure shown in Structure I can be used to disperse the pigment and can also be used as a polyurethane ink additive.

  The polyurethane ink additive is in the range of about 0.1 to about 12%, more preferably in the range of about 0.2 to about 10%, and even more preferably about 0.000, based on the weight of the total ink composition. It is present in the range of 25 to about 8% by weight.

  Drop speed, droplet separation length, droplet size and flow stability are greatly affected by the surface tension and viscosity of the ink. Ink jet inks typically have a surface tension in the range of about 20 dyne / cm to about 70 dyne / cm at 25 ° C. The viscosity can be as high as about 30 cP at 25 ° C., but is typically somewhat lower. The ink has physical properties that can be adjusted by the ejection conditions and the printhead design. The ink should have excellent storage stability over time so as not to clog the inkjet device to a significant degree. Furthermore, the ink should not corrode the parts of the inkjet printing device that come into contact and should be essentially odorless and non-toxic.

  While not limited to any particular viscosity range or printhead, lower viscosity inks can be used and may be preferred for certain applications. Thus, the viscosity of the ink (at 25 ° C.) can be less than about 7 cp, less than about 5 cp, or even less than about 3.5 cp.

Aqueous carrier medium The aqueous carrier medium (aqueous vehicle) is water or a mixture of water and at least one hydratable organic solvent. The selection of a suitable mixture depends on the specific application requirements such as the desired surface tension and viscosity, the selected pigment, the drying time of the pigment inkjet ink, and the type of paper on which the ink will be printed. . Representative examples of water-soluble organic solvents that can be selected include (1) methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, iso-butyl. Alcohols such as alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol; (2) ketones or keto alcohols such as acetone, methyl ethyl ketone and diacetone alcohol; (3) ethers such as tetrahydrofuran and dioxane; (4) ethyl acetate, ethyl lactic acid; Salts, esters such as ethylene carbonate and propylene carbonate; (5) ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol Polyols, polyethylene glycol, glycerol, 2-methyl-2,4-pentanediol 1,2,6-hexanetriol and polyhydric alcohols such as thiodiglycol; (6) ethylene glycol mono-methyl (or -ethyl) ether , Alkylenes such as diethylene glycol mono-methyl (or -ethyl) ether, propylene glycol mono-methyl (or -ethyl) ether, triethylene glycol mono-methyl (or -ethyl) ether and diethylene glycol di-methyl (or -ethyl) ether Lower alkyl mono- or di-ethers derived from glycols; (7) pyrrolidone, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone; 1,3-dihydroxyethyldimethyl hydride Nitrogen-containing cyclic compounds such as Knights Inn; and a sulfur-containing compound such as (8) dimethyl sulfoxide and tetramethylene sulfone.

  A mixture of water and a polyhydric alcohol such as diethylene glycol is preferred as the aqueous carrier medium. In the case of a mixture of water and diethylene glycol, the aqueous carrier medium typically contains about 30% water / 70% diethylene glycol to about 95% water / 5% diethylene glycol. A preferred ratio is approximately 60% water / 40% diethylene glycol to about 95% water / 5% diethylene glycol. The proportion is based on the total weight of the aqueous carrier medium. Mixtures of water and butyl carbitol are also effective aqueous carrier media.

  The amount of aqueous carrier medium in the ink typically ranges from about 70% to about 99.8%, and preferably from about 80% to about 99.8%, based on the total weight of the ink.

  Aqueous carrier media can be made fast penetrating (fast drying) by including surfactants or penetrants such as glycol ethers and 1,2-alkanediols. As glycol ethers, ethylene glycol monobutyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether Diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, Propylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether, Propylene glycol mono -n- butyl ether, dipropylene glycol mono -n- propyl ether and dipropylene glycol mono - isopropyl ether. The 1,2-alkanediol is preferably 1,2-C4-6 alkanediol, most preferably 1,2-hexanediol. Suitable surfactants include ethoxylated acetylenic diols (eg, Surfynols® series from Air Products), ethoxylated primary alcohols (eg, Neodol® series from Shell) and secondary alcohols (eg, For example, Tergitol® series from Union Carbide), sulfosuccinates (eg Aerosol® series from Cytec), organosilicones (eg Silwet® series from Witco) and fluorosurfactants (eg Zonyl (registered trademark) series manufactured by DuPont).

  The amount of glycol ether and 1,2-alkanediol added must be properly determined, but is typically from about 1 to about 15 weight percent and more typically based on the total weight of the ink. The range is from about 2 to about 10% by weight. Surfactants can typically be used in amounts of about 0.01 to about 5%, preferably about 0.2 to about 2%, based on the total weight of the ink.

Other Additives Other additives such as biocides, wetting agents, chelating agents and viscosity modifiers may be added to the ink for conventional purposes.

  Biocides can be used to inhibit microbial growth.

  Ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA), ethylenediamine-di (o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetic acid (NTA), dihydroxyethyleneglycine (DHEG), trans-1,2-cyclohexanediamine Tetraacetic acid (CyDTA), diethylenetriamine-N, N, N ′, N ″, N ″ -pentaacetic acid (DTPA), and glycol ether diamine-N, N, N ′, N′-tetraacetic acid (GEDTA), and these Inclusion of a sequestering (or chelating) agent such as a salt of can be advantageous, for example, to eliminate the deleterious effects of heavy metal impurities.

  When used, the other polymer additives can be soluble or dispersed polymers and can be used in addition to the polyurethane ink additive in the inks of the present invention. is there. These can be any suitable polymer, for example, soluble polymers can include linear homopolymers, copolymers, block polymers or natural polymers. These can also be structured polymers including grafted or branched polymers, stars, dendrimers and the like. The dispersion polymer can include latex and the like. These polymers can be formed by any known process including, but not limited to, free radicals, group transfer, ions, RAFT, condensation, and other types of polymerization. Useful classes of polymers include, for example, acrylic, styrene-acrylic, and alginate. These other polymer additives can be selected from polymers that can function as ISD polymer dispersants, but are not utilized as such.

  These polymer additives can be effective in improving jetting stability, storage stability of the ink before it is put in the cartridge, and stability in the cartridge. Other properties that can be acted upon by the polymer additive include, for example, reliability for thermal ink jet printing and image durability including smear resistance.

Ink Sets Suitable ink sets for use in the present invention include at least three primary inks: cyan ink, magenta ink, and yellow ink (CMY), where at least one of these inks (and preferably All three colors) are based on ISD and polyurethane ink additives. This ink set may optionally contain additional ink, in particular black ink (forming the CMYK ink set).

  When the ink set includes black ink, pigment is generally preferable for black from the viewpoint of high optical density. The black ink can be carbon black dispersed using an ionically stabilized dispersant as described herein. A polyurethane ink additive may also be present in the black ink. The optional black pigment is a carbon black pigment, in particular SDP black. Examples of SDP black and inks based thereon can be found, for example, in US Pat. No. 6,852,156, and other SDP types are referenced in US Pat. No. 6,852,156. (These disclosures are hereby incorporated by reference herein in their entirety for all purposes).

  In addition to the black ink, the ink set may further include one or more other colored inks such as, for example, an orange ink and / or a green ink.

  The ink set that includes the ISD dispersed pigment and the polyurethane ink additive may further include a fixing solution that may be advantageous in reducing blur and back-through in fast-drying aqueous inks. For example, the disclosures of which are hereby incorporated by reference herein in their entirety for all purposes, US Pat. No. 5,746,818, US Pat. No. 6,450,632. U.S. Patent Application Publication No. 20020044185, European Patent No. 1258510 and US Patent Application Publication No. 200402016658.

  Here, the present invention is illustrated in more detail, but is not limited by the following examples.

Formula ingredients and abbreviations BMEA = bis (methoxyethyl) amine DBTL = dibutyltin dilaurate DMEA = dimethylethanolamine DMIPA = dimethylisopropylamine DMPA = dimethylolpropionic acid DMBA = dimethylolbutyric acid EDA = ethylenediamine EDTA = ethylenediaminetetraacetic acid HDI = 1,6-hexa Methylene diisocyanate IPDI = isophorone diisocyanate TMDI = trimethylhexamethylene diisocyanate TMXDI = m-tetramethylenexylylene diisocyanate NMP = n-methylpyrrolidone TEA = triethylamine TEOA = triethanolamine TETA = triethylenetetramine THF = tetrahydrofuran tetraglyme = tetraethylene glycol dimethyl ether Especially Unless otherwise noted, the above chemicals were obtained from Aldrich (Milwaukee, WI) or other similar suppliers of laboratory chemicals.
TERATHANE® 650 is a polytetramethylene ether glycol (PTMEG) manufactured by Invista (Wichita, KS) TERATHANE® 250 is a 250 molecular weight polytetramethylene ether glycol.

Degree of polyurethane reaction The degree of polyurethane reaction was determined by detecting NCO% by dibutylamine titration, which is a common method in urethane chemistry.

  In this method, a sample of NCO-containing prepolymer is reacted with a known amount of dibutylamine solution and the remaining amine is back titrated with HCl.

Particle Size Measurement The particle size of the polyurethane dispersion, pigment and ink was measured by dynamic light scattering using a Microtrac® UPA150 analyzer from Honeywell / Microtrac (Montgomeryville, PA).

  This technique is based on the relationship between particle velocity distribution and particle size. Laser generated light is diffused by each particle and is Doppler shifted by particle Brownian motion. The frequency difference between the shifted light and the unshifted light is amplified, digitized and analyzed to obtain a particle size distribution.

  The number reported below is the volume average particle size.

Measurement of solid content The solid content of the polyurethane dispersion containing no solvent was measured with a water analyzer, model MA50, manufactured by Sartorius. For polyurethane dispersions containing high boiling solvents such as NMP, tetraethylene glycol dimethyl ether, the solids content was then measured by the weight difference before and after calcination in a 150 ° C. oven for 180 minutes.

MW characterization of polyurethane additives All molecular weights were measured by GPC (gel permeation chromatography) using poly (methyl methacrylate) standards with tetrahydrofuran as eluent. Using the statics derived by Flory, the molecular weight of the polyurethane can be calculated or predicted based on the NCO / OH ratio and the molecular weight of the monomer. Molecular weight is also a characteristic of polyurethane that can be used to define polyurethane. Molecular weight is routinely reported as number average molecular weight Mw. For urea terminated polyurethane ink additives, the preferred molecular weight range is 2000-30000, or more preferably 3000-20000. For the crosslinked polyurethane ink additive, the preferred molecular weight is greater than 30,000 as Mn. The polyurethane additive is not limited to a Gaussian distribution of molecular weight and may have other distributions such as a bimodal distribution.

Salt Stability Test The polymer dispersion and ink test procedures used in these examples are described below.
(A) A salt solution is prepared by diluting a stock solution (eg, 0.2 molar NaCl) with deionized water.
(B) 1.5 g (ml) of salt solution is added to a glass vial (19 mm × 65 mm vial with cap) with a disposable full volume pipette (the pipette used is a SAMCO full volume pipette, catalog number 336B / B) -PET, Samco Scientific Corp (San Fernado, CA)).
(C) Add the entire volume of the test solution with a pipette. One drop is used for the dispersion concentrate. Three drops are used for the ink sample.
(D) Mix thoroughly with gentle agitation.
(E) Let the mixture stand at room temperature for 24 hours.
(F) Record a visual observation of each sample.
Grade 3: Complete precipitation of pigment; clear, colorless liquid on top.
Grade 2: no clear, colorless liquid layer; when the vial is tilted, a clear settling is observed at the bottom of the vial.
Grade 1: no clear, colorless liquid layer; very slight sedimentation (small isolated spots) is observed while tilting the vial.
Grade 0: No signs of settling.

Measurement of THF Insoluble Content The THF insoluble content of the polyurethane was measured by first mixing 1 gram of dispersed polyurethane and 30 grams of THF into a pre-lightweight centrifuge tube. After centrifuging the solution at 17,000 rpm for 2 hours, the top liquid layer was poured out, leaving the bottom undissolved gel. The centrifuge tube containing the undissolved gel was reweighed after the tube was placed in an oven and dried at 110 ° C. for 2 hours.

  % Microgel of polyurethane = ((weight of tube and undissolved gel) − (weight of tube)) / (sample weight × polyurethane solid%).

Polymeric Dispersants The following synthesis examples are all based on group transfer polymerization (GTP), but other types of polymerization processes can be used to produce similar types of polymers. In the case of block polymers, the current block was converted at least 95% before adding the monomer mixture for the next block. In all cases, supply cycle strategies are described. However, the synthesis was stopped when 99% of the polymer was converted as detected by HPLC. Reported molecular weights (unless otherwise noted) are based on theoretical considerations. For random linear polymers, the stated ratio is the weight ratio of monomer units in the final polymer; for triblock and other polymers, this ratio is the molar ratio of monomer components.

  Standard experimental techniques were employed for the following examples.

  The acid value was measured by titration and is reported as mg / 1 gram polymer solids. The molecular weight was measured by GPC. GPC separations were performed using four column sets consisting of two 500-Å and two 100-Å, 30 cm x 7.8 mm ID, Microstyragel columns (Waters (Milford, Mass.)). Tetrahydrofuran mobile phase was sent through a Hewlett-Packard (PaloAlto, CA) model 1090 gradient liquid chromatograph at a flow rate of 1.0 mL / min. The eluting species were detected using a Hewlett-Packard 1047A differential refraction detector. A thin low molecular weight poly (methyl-methacrylate) standard was used as the calibration material. The particle size was measured by dynamic light scattering using a Microtrac Analyzer (Largo, Florida). For many of the dispersion steps, a model 100F or Y from Microfluidics System (Newton, Mass.) Was used.

  In referring to the polymer composition, it should be noted that double slashes indicate separation between blocks and a single slash indicates a random copolymer. Thus, for example, BZMA / MAA 90/10 is a random copolymer having about 90 wt% benzyl methacrylate (BZMA) and about 10 wt% methacrylic acid (MAA) units in the final polymer; and BZMA // MAA // BZMA 8 // 10 // 8 is an ABA trilogy where the first A block is 8 BZMA unit length on average, the B block is 10 MAA unit length on average, and the last A block is 8 BZMA unit length on average Block polymer.

ISD Dispersant 1a BZMA / MAA 90/10 Random Linear Copolymer A 5 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. Tetrahydrofuran (THF), 1715.1 g, was charged to the flask. The catalyst (tetrabutyl ammonium m-chlorobenzoate, 1.2 mL of a 1.0 M solution in acetonitrile) was then added. Initiator (1-methoxy-1-trimethylsiloxy-2-methylpropene, 51.33 g (0.295 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate 1.2 mL of a 1.0 M solution in acetonitrile and THF, 10.0 g) was started and added over 180 minutes. Feed II (trimethylsilyl methacrylate, 267.6 g (1.69 mol) and benzyl methacrylate (BZMA), 1305.6 g (7.42 mol)) was started at 0.0 minutes and added over 70 minutes.

  At 173 minutes, 60.5 g of methanol was added to the above solution and distillation started. During the first stage of distillation, 503.0 g of material was removed. The final polymer solution was 51.5% solids.

  The polymer had a composition of BZMA / MAA 90/10; 5048 molecular weight (Mn); and an acid value of 1.24 (millieq / 1 gram polymer solids) based on total solids.

ISD Dispersant 1b BZMA / MAA 90/10 Random Linear Copolymer A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. Tetrahydrofuran (THF), 1200 g, was charged to the flask. The catalyst (0.75 mL of a 1.0 M solution of tetrabutylammonium m-chlorobenzoate in acetonitrile) was then added. Initiator (1,1-bis (trimethylsilyloxy) -2-methylpropene, 42.5 g (0.18 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate, 0.4 mL of a 1.0 M solution in acetonitrile and THF, 5 g) was started and added over 180 minutes. Feed II (trimethylsilyl methacrylate, 135.5 g (0.86 mol) and benzyl methacrylate, 825.5 g (4.69 mol)) was started at 0.0 minutes and added over 45 minutes.

  At 125 minutes, 70 g of methanol was added to the above solution and distillation started. During the first stage of distillation, 375 g of material was removed. The final polymer solution was 48.5% solids.

  The polymer had a molecular weight (Mn) of BZMA / MAA 90/10; 4995, and an acid value composition of 1.22 (millieq / 1 gram polymer solids) based on total solids.

ISD Dispersant 2a BZMA / MAA 92/8 random linear copolymer The same preparation as Preparation 1a was used, except that 213.2 g of trimethylsilyl methacrylate and 1334.5 g of benzyl methacrylate were used. This is 51.7% solids with a composition of BZMA / MAA 92/8, 5047 molecular weight (Mn) and acid value of 0.99 (meq / 1 gram polymer solids) based on total solids A polymer solution was produced.

ISD Dispersant 2b BZMA / MAA 92/8 Random Linear Copolymer with 2-Pyrrolidone as Final Solvent In a 5 liter flask, 1449 g of polymer 2a solution was added along with 412 g of 2-pyrrolidone. The solution was heated to reflux and 56 g of solvent was evaporated. 320.5 g of 2-pyrrolidone was then added to form a 45.7% solids polymer solution.

ISD Dispersant 2c BZMA / MAA 92/8 Random Linear Copolymer 103.0 g Trimethylsilyl methacrylate (0.65 mol), 844 g benzyl methacrylate (4.80 mol) and 55 g methanol and with 354 g material removed Used the same preparation as polymer preparation 1b. The final polymer solution was 48.4% solids.

  The polymer had a molecular weight (Mn) of BZMA / MAA 92/8; 4999, and an acid value composition of 0.98 (meq / 1 gram polymer solids) based on total solids.

ISD Dispersant 2d Neutralization of Polymer 2b with Potassium Hydroxide The following formulation ingredients were combined with stirring.

  In a 2 liter flask, 1000 g of polymer la solution was added. The solution was heated to reflux and 284 g of solvent was evaporated. 221 g of 2-pyrrolidone was then added to the flask. An additional 156 g of solvent was evaporated and 266 g of 2-pyrrolidone was added to form a 47% solids polymer solution.

ISD Dispersant 3a BZMA / MAA 94/6 random linear copolymer The same preparation as Preparation 1a was used, except that 160.3 g of trimethylsilyl methacrylate and 1363.5 g of benzyl methacrylate were used. The result is 49.9% solids with a composition of BZMA / MAA 94/6, molecular weight (Mn) of 5047, and an acid value of 0.77 (meq / 1 gram polymer solids) based on total solids. It was a polymer solution.

ISD Dispersant 3b BZMA / MAA 94/6 random linear copolymer containing 2-pyrrolidone as final solvent In a similar preparation to 2b, a polymer 3a solution was prepared with 2-pyrrolidone as the final solvent. The resulting solids content was 43.93%, THF was 8.8%, and 2-pyrrolidone was 47.27%.

ISD Dispersant 4 BZMA // MAA 5 // 1 short chain B block A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. Tetrahydrofuran THF, 1000.6 gm, was charged to the flask. 4.0 mL of a 1.0 M solution of catalyst tetrabutylammonium m-chlorobenzoate in acetonitrile was then added. The initiator, 1,1-bis (trimethylsiloxy) -2-methylpropene, 232.7 gm (1.00 mol) was injected. Feed I [benzyl methacrylate, 881.0 gm (5.00 mol)] was started at 0.0 minutes and added over 60 minutes.

  At 190 minutes, 64.2 gm of methanol was added to the above solution and distillation started. During the first stage of distillation, 457.7 gm of material was removed. The final polymer was 54.0% solids.

  The polymer had a composition of BZMA // MAA 5 // 1. This had an acid value of 0.90 (millieq / 1 gram polymer solids) based on the molecular weight of Mn = 886 and the total solids.

ISD dispersant 4b BZMA // MAA 5 // 1 short chain B block The same preparation as Preparation 4b was used, except that the monomer BZMA // MAA was used in a molar ratio of 5 // 1. This resulted in a polymer of 43.75% solids in 2-pyrrolidone.

ISD Dispersant 5 BZMA // MAA // BZMA 8 // 10 // 8 Triblock Copolymer A 5 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and addition funnel. A flask was charged with 1721.0 g of THF. The catalyst (1.9 mL of a 1.0 M solution of tetrabutylammonium m-chlorobenzoate in acetonitrile) was then added. Initiator (1-methoxy-1-trimethylsiloxy-2-methylpropene, 80.17 g (0.46 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate 1.8 mL of a 1.0 M solution in acetonitrile and THF, 16.92 g) was started and added over 210 minutes. Feed II (BZMA, 649.3 g (3.69 mol)) was started at 0.0 minutes and added over 45 minutes. Thirty minutes after completion of Feed II (over 99% of the monomers had reacted), Feed III (trimethylsilyl methacrylate, 726.7 g (4.60 mol)) was started and added over 30 minutes. 150 minutes after completion of Feed III (more than 99% of the monomers had reacted), Feed IV (BZMA, 647.5 g (3.68 mol)) was started and added over 30 minutes.

  At 500 minutes, 300.0 g of methanol was added to the above solution and distillation started. 750.0 g of material was removed to produce a final polymer solution of 51.5% solids in tetrahydrofuran.

  The polymer is composed of BZMA // MAA // BZMA 8 // 10 // 8, molecular weight (Mn) of 3780, and acid value composition of 2.88 (meq / 1 gram polymer solids) based on total solids. Had.

ISD Dispersant 6 BZMA / ETEGMA / MAA 84/10/6 Random Linear Copolymer A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. A flask was charged with 1200 g of THF. The catalyst (tetrabutylammonium m-chlorobenzoate, 0.76 mL of a 1.0 M solution in acetonitrile) was then added. Initiator (1-methoxy-1-trimethylsiloxy-2-methylpropene, 32 g (0.18 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate 0.76 mL of a 1.0 M solution in acetonitrile and THF, 10 g) was started and added over 300 minutes. Feed II (trimethylsilyl methacrylate, 99.4 g (0.63 mol), benzyl methacrylate, 754.1 g (4.28 mol), and ethoxytriethylene glycol methacrylate (ETEGMA), 92.1 g (0.37 mol)) Starting at 0.0 minutes and added over 45 minutes.

  At 175 minutes, 55 g of methanol was added to the above solution and distillation started. 350.5 g of material was removed to produce a final polymer solution of 49.1% solids.

  The polymer has a composition of BZMA / ETEGMA / MAA 84/10/6, molecular weight (Mn) of 4994, and acid value of 0.79 (meq / 1 gram polymer solids) based on total solids. It was.

ISD Dispersant 7 BZMA // DMAEMA 13 // 3.4 Diblock Copolymer A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. THF, 540 g, was charged to the flask. The catalyst (tetrabutyl ammonium m-chlorobenzoate, 0.69 g of a 1.0 M solution in acetonitrile) was then added. Initiator (1-methoxy-1-trimethylsiloxy-2-methylpropene, 29.8 g (0.17 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate, 0.35 g of a 1.0 M solution in acetonitrile and THF, 5 g) was started and added over 150 minutes. Feed II (N, N-dimethylaminoethyl methacrylate, 92.3 g (0.59 mol)) was added at 0.0 minutes and added over 30 minutes. Feed III (benzyl methacrylate, 390.8 g (2.22 mol)) was started over 60 minutes and added over 30 minutes.

  At 135 minutes, 11 g of methanol was added to the above solution and Feed I was stopped. Distillation was used to remove 48 g of material, resulting in a final polymer solution of 47.3% solids.

  This polymer is an amine of 1.18 (meq / 1 gram polymer solids) based on BZMA // DMAEMA 13 // 3.4 (molar ratio), 2930 theoretical molecular weight (Mn), and total solids. Value composition.

ISD Dispersant 8a BZMA / DMAEMA 85.5 / 14.5 Random Linear Copolymer A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. A flask was charged with 552 g of THF. The catalyst (tetrabutyl ammonium m-chlorobenzoate, 0.37 g of a 1.0 M solution in acetonitrile) was then added. Initiator (1-methoxy-1-trimethylsiloxy-2-methylpropene, 16.8 g (0.096 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate, 0.19 g of a 1.0 M solution in acetonitrile and THF, 5 g) was started and added over 150 minutes. Feed II (N, N-dimethylaminoethyl methacrylate, 71.7 g (0.46 mol) and benzyl methacrylate, 419.6 g (2.38 mol)) was started at 0.0 minutes and added over 30 minutes. .

  At 85 minutes, 6.6 g of methanol was added to the above solution and Feed I was stopped. Distillation was used to remove 28.5 g of material, resulting in a final polymer solution of 47.8% solids.

  This polymer is an amine of 0.92 (meq / 1 gram polymer solids) based on BZMA / DMAEMA 85.5 / 14.5 (weight ratio), theoretical molecular weight (Mn) of 5370, and total solids. Value composition.

ISD Dispersant 9 BZMA // MAA 13 // 3 short chain B block copolymer A 12 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and addition funnel. THF, 3866 g, was charged to the flask. The catalyst (tetrabutyl ammonium m-chlorobenzoate, 1.2 mL of a 1.0 M solution in acetonitrile) was then added. Initiator (1,1-bis (trimethylsilyloxy) -2-methylpropene, 281.1 g (1.21 mol)) was injected. Feed I (trimethylsilyl methacrylate, 382.8 g (2.42 mol)) was started and added over 30 minutes. At 117 minutes, Feed II (benzyl methacrylate, 2767.7 g (15.73 moles)) was started and added over 64 minutes. At 240 minutes, 232 g of methanol was added to the above solution and distillation started. 1180 g of material was removed resulting in a final polymer solution of 50.82% solids.

  This polymer has a BZMA // MAA 13 // 3 (molar ratio), a molecular weight (Mn) of 2522, a polydispersity of 1.26, and 1.23 (meq / 1 gram polymer solids based on total solids) Min) acid value composition.

(CP1) Comparative dispersion polymer 1 ETEGMA // BZMA // MAA 3.6 // 13.6 // 10.8
The following is an example of how to form a block polymer with both ionic stabilization as well as steric stabilization.

A 3 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. Tetrahydrofuran THF, 291.3 g, was charged to the flask. 0.44 mL of a 1.0 M solution of catalyst tetrabutylammonium m-chlorobenzoate in acetonitrile was then added. The initiator, 1,1-bis (trimethylsiloxy) -2-methylpropene, 20.46 g (0.0882 mol) was injected. Feed I [tetrabutylammonium m-chlorobenzoate, 0.33 mL of a 1.0 M solution in acetonitrile and THF, 16.92 g] was started and added over 185 minutes. Feed II [trimethylsilyl methacrylate, 152.00 g (0.962 mol)] was started at 0.0 minutes and added over 45 minutes. 180 minutes after completion of Feed II (more than 99% of the monomers had reacted), Feed III [benzyl methacrylate, 211.63 g (1.20 mol) was started and added over 30 minutes. 40 minutes after the completion of Feed III (over 99% of the monomers had reacted), Feed IV [ethoxytriethylene glycol methacrylate, 78.9 g (0.321 mol) was started and added over 30 minutes.

  At 400 minutes, 73.0 g of methanol and 111.0 g of 2-pyrrolidone were added to the above solution and distillation started. During the first stage of distillation, 352.0 g of material was removed. An additional 340.3 g of 2-pyrrolidone was then added and an additional 81.0 g of material was evaporated. Finally, a total of 86.9 g of 2-pyrrolidone was added. The final polymer was 40.0% solids.

  The polymer had a composition of ETEGMA // BZMA // MAA 3.6 // 13.6 // 10.8. This has a molecular weight of Mn = 4,200 and an acid value of 2.90.

Neutralization of Comparative Polymer 1 with potassium hydroxide The following formulation ingredients were combined with stirring.

(CP2) Comparative dispersant polymer 2 -BZMA // MAA 13 // 10
The following is an example of how to form a block polymer with both ionic stabilization as well as steric stabilization. The composition was BZMA // MAA 13 // 10.

A 12 liter flask was equipped with a mechanical stirrer, thermometer, N ₂ inlet, drying tube outlet, and dropping funnel. THF, 3750 g, and p-xylene, 7.4 g were charged to the flask. The catalyst (tetrabutylammonium m-chlorobenzoate, 3.0 mL of a 1.0 M solution in acetonitrile) was then added. Initiator (1,1-bis (trimethylsiloxy) -2-methylpropene, 291.1 g (1.25 mol)) was injected. Feed I (tetrabutyl ammonium m-chlorobenzoate, 3.0 mL of a 1.0 M solution in acetonitrile) was started and added over 180 minutes. Feed II (trimethylsilyl methacrylate, 1975 g (12.5 mol)) was started at 0.0 minutes and added over 35 minutes. 100 minutes after completion of Feed II (more than 99% of the monomers had reacted), Feed III (benzyl methacrylate, 2860 g (16.3 moles)) was started and added over 30 minutes.

  At 400 minutes, 720 g of methanol was added to the above solution and distillation started. During the first stage of distillation, 1764.0 g of material was removed. An additional 304.0 g of methanol was then added and an additional 2255.0 g of material was evaporated. The final polymer solution was 49.7% solids.

  The polymer had a molecular weight (Mn) of BZMA // MAA 13 // 10, 3200, and an acid value composition of 3.52 (meq / 1 gram polymer solids) based on total solids. .

Polyurethane Ink Additive Polyurethane Ink Additive Example 1 IPDI / 500 PO3G / DMPA AN30
The preparation was done in polyurethane ink additive example 2 (below) except that isophorone diisocyanate was used in place of toluene diisocyanate and the formulation was adjusted for molecular weight differences to maintain the same NCO / OH ratio. Prepared). The polyurethane dispersion had a viscosity of 24.4% solids, a particle size of 22.1 cP, d50 = nm and d95 = nm, and a molecular weight by GPC of Mn8170, Mw18084 and Pd2.21. The urea content is 4.2%.

Polyurethane Ink Additive Example 2 TDI / 500 PO3G / DMPA AN30
A 2 L reactor was charged with 166.4 PO3G (545 MW, 95.8 g tetraethylene glycol dimethyl ether, and 21.2 g dimethylolpropionic acid. The mixture was placed under reduced pressure at 110 ° C. with a content of less than 400 ppm The reaction was then cooled to 70 ° C. and 89.7 g toluene diisocyanate was added over 30 minutes followed by 15.8 g tetraethylene glycol dimethyl ether. Was kept at 80 ° C. and% NCO was less than 1.5% in 2 hours, then 12.4 g bis (2-methoxyethyl) amine was added over 5 minutes, after 1 hour at 60 ° C. , 50 g were removed for analysis and the remaining polyurethane solution was 45% KOH (15. The polyurethane dispersion was converted under high speed mixing by adding a mixture of g) and 218.0 g water followed by additional 464 g water.The polyurethane dispersion had a viscosity of 17.6 cP, 22.9% solids , D50 = 16 nm and d95 = 35 nm particle size, and molecular weight by GPC of Mn7465, Mw15500 and Pd2.08, urea content is 4.3.

Polyurethane Ink Additive Example 3 IPDI / T250 / DMPA BMEA AN30
A 2L reactor was charged with 104.3 Terathane 250, 95.2 g tetraethylene glycol dimethyl ether, and 20.8 g dimethylolpropionic acid. The mixture was heated to 115 ° C. for 1 hour with N 2 purge. The reaction was then cooled to 70 ° C. and 0.4 g dibutyltin dilaurate was added. Over 30 minutes, 142.7 g isophorone diisocyanate was added followed by 23.8 g tetraethylene glycol dimethyl ether. When the reaction was held at 80 ° C., the% NCO was less than 1.0% in 4.5 hours. 15.6 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.2 g) and 214 g water followed by an additional 443 g water. The polyurethane dispersion had a pH of 8.2, 25.4% solids, a viscosity of 17.8 cP, and a particle size of d50 = 16 nm and d95 = 24 nm.

Polyurethane Ink Additive Example 4 IPDI / T650 / DMPA AN30
A 2 L reactor was charged with 154.3 g Terathane® 650, 95.2 g tetraethylene glycol dimethyl ether, and 20.4 g dimethylolpropionic acid. The mixture was heated to 110 ° C. with N 2 purge for 10 minutes. The reaction was then cooled to 80 ° C. and 0.4 g dibutyltin dilaurate was added. Over 30 minutes, 96.0 g isophorone diisocyanate was added followed by 24.0 g tetraethylene glycol dimethyl ether. The reaction was held at 80 ° C. and the% NCO was less than 1.2% in 2 hours. Then 10.6 g bis (2-methoxyethyl) amine was added over 5 minutes. After 2 hours at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (16.8 g) and 236 g water followed by an additional 467 g water. The polyurethane dispersion had a viscosity of 11.4 cP, 25.3% solids, a particle size of d50 = 22 nm and d95 = 35 nm, and a molecular weight by GPC of Mn6520, Mw16000 and Pd2.5. The urea content is 8.8%.

Polyurethane Ink Additive Example 5 TDI / T650 / DMPA AN30
A 2L reactor was charged with 164.6 Terathane 650, 101.4 g tetraethylene glycol dimethyl ether, and 21.6 g dimethylolpropionic acid. The mixture was heated to 115 ° C. for 1 hour with N ₂ purge. The reaction was then cooled to 70 ° C. and 81.1 g toluene diisocyanate was added over 30 minutes followed by 20.6 g tetraethylene glycol dimethyl ether. The reaction was held at 80 ° C. and the% NCO was less than 1.5% in 5 hours. 11.2 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 2 hours at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.8 g) and 221.9 g water followed by an additional 418 g water. . The polyurethane dispersion has a pH of 7.9, 22.7% solids, a viscosity of 27.1 cP, a particle size of d50 = 15 nm and d95 = 25 nm, and a molecular weight by GPC of Mn8557, Mw16951 and Pd1.98. Was.

Polyurethane Ink Additive Example 6 IPDI / T650 / DMPA AN30
A 2 L reactor was charged with 154.3 Terathane 650, 95.2 g tetraethylene glycol dimethyl ether, and 20.3 g dimethylolpropionic acid. The mixture was heated to 115 ° C. for 1 hour with N 2 purge. The reaction was then cooled to 70 ° C. and 0.4 g dibutyltin dilaurate was added. Over 30 minutes, 96.0 g isophorone diisocyanate was added followed by 23.8 g tetraethylene glycol dimethyl ether. When the reaction was held at 80 ° C., the% NCO was less than 1.3% in 4.5 hours. 10.5 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (14.9 g) and 208.5 g water followed by an additional 440 g water. . The polyurethane dispersion had a pH of 7.9, 24.4% solids, a particle size of d50 = 19 nm and d95 = 30 nm, and a molecular weight by GPC of Mn9057, Mw18641 and Pd2.06. The urea content is 3.7.

Polyurethane Ink Additive Example 7 IPDI / T650 / DMPA AN45
A 2L reactor was charged with 136.7 g Terathane® 650, 84.3 g tetraethylene glycol dimethyl ether, and 32.1 g dimethylolpropionic acid. The mixture was heated to 110 ° C. for 1 hour with N 2 purge. The reaction was then cooled to 80 ° C. and 0.3 g dibutyltin dilaurate was added. Over 30 minutes, 108.9 g isophorone diisocyanate was added followed by 28.2 g tetraethylene glycol dimethyl ether. When the reaction was held at 80 ° C., the% NCO was less than 1.6% at 5.5 hours. 11.9 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 2 hours at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (22.8 g) and 320 g water followed by an additional 361.5 g water. . The polyurethane dispersion had a viscosity of 20.6 cP, 23.7% solids, a particle size of d50 = 14 nm and d95 = 18 nm, and a molecular weight by GPC of Mn 6320, Mw 17000 and Pd 2.7. The urea content is 4.1%.

Polyurethane Ink Additive Example 8 IPDI / T650 / DMPA AN60
The preparation was done with a polyurethane ink additive, except that some Terathane 650 was replaced with additional dimethylolpropionic acid to maintain the same NCO / OH ratio while adjusting the final acid number of the polyurethane to 60 mg KOH / g polymer. It was equivalent to Example 1. The polyurethane dispersion had a viscosity of 21 cP at 24.1% solids, a particle size of d50 = 19 nm and d95 = 24 nm, and a molecular weight by GPC of Mn 5944. The urea content is 4.5%.

Polyurethane ink additive Example 9a DEA end-capped 1,6 hexanediol, AN60
In a dry, alkali and acid free flask equipped with a dropping funnel, condenser, stirrer and nitrogen gas line, add 55 g 1,6 hexanediol, 48 g DMPA, 32.2 g TEA, 100 g acetone and 0.06 g DBTL was added. The contents were heated to 40 ° C. and mixed well. 227 g IPDI was then added to the flask via a dropping funnel at 40 ° C. over 60 minutes, and any remaining IPDI was rinsed from the dropping funnel into the flask with 10 g acetone.

  The flask temperature was raised to 50 ° C. and held at 50 ° C. until the NCO% was below 3.5%, then 39.5 grams DEA was added over 5 minutes followed by a 5 gram acetone rinse. . After 1 hour at 50 ° C., 613 g of deionized (DI) water was added via an addition funnel over 10 minutes. The mixture was held at 50 ° C. for 1 hour and then cooled to room temperature. Acetone (-115 g) was removed under reduced pressure to leave a polyurethane solution of about 35.0 wt% solids. The final polyurethane dispersion had a viscosity of 30 cP, pH 7.5, and a particle size of d50 = 86.5 nm.

Polyurethane Ink Additive Example 9b IPDI / HD BMEA AN30
A 2 L reactor was charged with 70.9 1,6-hexanediol, 55.3 g tetraethylene glycol dimethyl ether, and 21.5 g dimethylolpropionic acid. The mixture was heated to 110 ° C. with N 2 purge for 30 minutes. The reaction was then cooled to 80 ° C. and 0.5 g dibutyltin dilaurate was added. Over 30 minutes, 185.8 g isophorone diisocyanate was added followed by 45.8 g tetraethylene glycol dimethyl ether. When the reaction was held at 85 ° C., the% NCO was less than 2.1% in 2 hours. Then 20.3 g bis (2-methoxyethyl) amine was added over 5 minutes. After 1 hour at 85 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.7 g) and 222 g water followed by additional 489 g water. The polyurethane dispersion has a viscosity of 9.9 cP, 25.3% solids, pH 8.0, particle size of d50 = 17 nm and d95 = 26 nm, and molecular weight by GPC of Mn5611, Mw10316 and PD1.8. It was. The urea content is 6.8%.

Polyurethane Ink Additive Example 10 IPDI / DDD BMEA AN30
A 2 L reactor was charged with 95.9 1,12-dodecanediol, 74.9 g tetraethylene glycol dimethyl ether, and 20.6 g dimethylolpropionic acid. The mixture was heated to 110 ° C. for 1 hour with N 2 purge. The reaction was then cooled to 80 ° C. and 0.4 g dibutyltin dilaurate was added. Over 30 minutes, 153.5 g isophorone diisocyanate was added followed by 37.9 g tetraethylene glycol dimethyl ether. When the reaction was held at 85 ° C., the% NCO was less than 1.8% in 2 hours. 16.9 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 85 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (16.9 g) and 214 g water followed by an additional 458 g water. The polyurethane dispersion has a viscosity of 11.2 cP, 25.4% solids, pH 7.9, particle size of d50 = 17 nm and d95 = 25 nm, and molecular weight by GPC of Mn 6640, Mw 12615, and PD 1.9. It was. The urea content is 5.9%.

Polyurethane Ink Additive Example 11 IPDI / 1000PEG / DMPA BMEA AN20
A 2L reactor was charged with 154.1 g polyethylene glycol (1075 MW, Carbowax Sentry from Dow), 88.1 g tetraethylene glycol dimethyl ether, and 18.0 g dimethylolpropionic acid. The mixture was heated at 110 ° C. under reduced pressure. The reaction was then cooled to 75 ° C. and 0.2 g dibutyltin dilaurate was added. Over 30 minutes, 71.1 g isophorone diisocyanate was added followed by 11.7 g tetraethylene glycol dimethyl ether. When the reaction was held at 80 ° C., the% NCO was less than 1.0% in 5.5 hours. 7.8 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.1 g) and 211.0 g water followed by an additional 420 g water. . The polyurethane dispersion had a viscosity of 59.2 cP, a pH of 6.7, 23.9% solids, and a particle size of d50 = 4 nm and d95 = 7 nm. The urea content is 3/1%.

Polyurethane Ink Additive Example 12 11 IPDI / HQEE / DMPA BMEA AN30
A 2L reactor was charged with 95.2 hydroquinone di- (β-hydroxyethyl) ether (Poly-G HQEE from Arch Chemical), 74.3 g tetraethylene glycol dimethyl ether, and 20.8 g dimethylolpropionic acid. The mixture was heated to 115 ° C. for 1 hour with N 2 purge. The reaction was then cooled to 85 ° C. and 154.5 g isophorone diisocyanate was added over 30 minutes followed by 38.1 g tetraethylene glycol dimethyl ether. After the isocyanate feed was completed, 0.3 g dibutyltin dilaurate was added. The reaction was held at 85 ° C. and the% NCO was less than 1.9% in 4 hours. 16.9 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.4 g) and 214 g water followed by an additional 458 g water. The polyurethane dispersion has a viscosity of 34.4 cP, a pH of 25.3% solids, a pH of 8.46, a particle size of d50 = 11 nm and d95 = 16 nm, and a molecular weight by GPC of Mn6445, Mw12473 and Pd1.94. Was. The urea content is 5.9%.

Polyurethane Ink Additive Example 13 IPDI / 500PC / DMPA BMEA AN30
A 2 L reactor was charged with 146.3 Eternacoll UH50 (Ube polycarbonate diol, 501 MW), 84.2 g tetraethylene glycol dimethyl ether, and 20.8 g dimethylolpropionic acid. The mixture was heated to 75 ° C. with N 2 purge for 1 hour. Then 0.5 g dibutyltin dilaurate was added and 109.4 g isophorone diisocyanate was added over 30 minutes followed by 28.1 g tetraethylene glycol dimethyl ether. The reaction was held at 80 ° C. and% NCO was less than 1.1% in 1.5 hours. 12.0 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (15.3 g) and 225 g water followed by an additional 450.2 g water. . The polyurethane dispersion had a viscosity of 8.8 cP, 24.4% solids, a pH of 8.1, and a particle size of d50 = 14 nm and d95 = 28 nm. Urea content 4.16%.

Polyurethane ink additive example 14 (crosslinked polyurethane)
699.2 g Desmophen C200, 280.0 g acetone and 0.06 g DBTL were added to an alkali and acid free dry flask equipped with a dropping funnel, condenser, stirrer and nitrogen gas line. The contents were heated to 40 ° C. and mixed well. 189.14 g IPDI was then added to the flask via a dropping funnel at 40 ° C. over 60 minutes, and any remaining IPDI was rinsed from the dropping funnel into the flask with 15.5 g acetone.

  The flask temperature was raised to 50 ° C. and then maintained for 30 minutes. 44.57 g DMPA followed by 25.2 g TEA was added to the flask via the addition funnel, which was then rinsed with 15.5 g acetone. The flask temperature was then raised again to 50 ° C. and maintained at 50 ° C. until the NCO% was below 1.23%.

  At a temperature of 50 ° C., 1498.0 g deionized (DI) water was added over 10 minutes, followed by 24.4 g EDA (as a 6.25% aqueous solution) and 118.7 g TETA (6.25% aqueous solution). As) was added via an addition funnel over 5 minutes, then it was rinsed with 80.0 g water. The mixture was held at 50 ° C. for 1 hour and then cooled to room temperature.

  Acetone (−310.0 g) was removed under reduced pressure to leave a final dispersoid of polyurethane having about 35.0 wt% solids.

  For polyurethane dispersoid 2, crosslinking was achieved with tetraethylenetriamine. The urea content is 0.95% by weight.

Polyurethane Ink Additive Example 15 12IPDI / 15DHE T650 BMEA 45AN 90% KOH
A 2L reactor was charged with 109.7 g Terathane® 650, 33.8 g tetraethylene glycol dimethyl ether, and 6.6 g Dantocol DHE (1,3-dihydroxyethyldimethylhydantoin) and 27.0 g dimethylolpropionic acid. Filled. The mixture was heated to 75 ° C. for 20 minutes while purging with N ₂ . Then 0.4 g dibutyltin dilaurate was added. Over 60 minutes, 96.6 g isophorone diisocyanate was added followed by 8.0 g tetraethylene glycol dimethyl ether. When the reaction was held at 80 ° C., the corrected% NCO was less than 1.5% in 4 hours. 9.7 g bis (2-methoxyethyl) amine was then added over 5 minutes. After 1 hour at 80 ° C., the polyurethane solution was inverted under high speed mixing by adding a mixture of 45% KOH (22.6 g) and 317 g water followed by additional 372 g water. The polyurethane dispersion had a viscosity of xxx cP, xxx% solids, particle size of d50 = xx nm and d95 = xx nm, and molecular weight by GPC of Mn xxx, Mw xxx, and Pd xx. The urea content is 3.9%.

Dispersion Preparation 1-Black Dispersion (PD1)
An aqueous black pigment dispersion was prepared by mixing the following formulation ingredients with proper stirring.

  The dispersion was prepared with the following formulation.

  The listed formulation ingredients were mixed thoroughly and then dispersed using a Microfluidics system. The above was then diluted with 138 g of water and dispersed again with a Microfluidics system to give a 10 wt% pigment solids dispersion having an average particle size of 119 nm.

Dispersion Preparation 2-Magenta Dispersion (PD2)
An aqueous magenta pigment dispersion was first prepared by pulverizing the following formulation ingredients with a 2-roll mill.

  While this was pulverized, a magenta dispersion in the form of chips having a solid content of 89.7% by weight was formed. Next, it was first diluted by mixing the following formulation ingredients.

  The dispersion was then mixed at 3000 rpm for 4 hours in a high speed disperser. Following this, 500.0 g of the dispersion was removed and mixed with 53.75 g of Dowanol® DPM and 253.75 g of deionized water. This dispersion was then ground in a media mill. The dispersion is then purified by dilution with water, and excess solvent is removed via an ultrafiltration process to have 14.09 wt with less than 1.0 wt% solvent (other than water). % Pigment solids dispersion was produced.

Dispersion Preparation 3-Cyan Dispersion (PD3)
An aqueous cyan pigment dispersion was first prepared by pulverizing the following formulation components with a 2-roll mill.

  While this was pulverized, a cyan dispersion in the form of chips having a solid content of 93.45 wt% was formed. Next, it was first diluted by mixing the following formulation ingredients.

  The dispersion was then mixed for 3 hours at 4000 rpm in a high speed disperser and then subsequently ground in a media mill for 4 hours. The dispersion was then purified by diluting 341 g of material with 441 g of deionized water, and excess solvent was removed via an ultrafiltration process to obtain less than 1.0 wt% solvent (other than water), And a 13.65 wt% pigment solids dispersion having an average particle size of 123 nm.

Dispersion Preparation 4-Yellow Dispersion (PD4)
An aqueous yellow pigment dispersion was first prepared by pulverizing the following formulation components with a 2-roll mill.

While this was pulverized, a yellow dispersion in the form of chips having a solid content of 89.16 wt% was formed. Next, it was first diluted by mixing the following formulation ingredients.

  The dispersion was then mixed at 3000 rpm for 4 hours in a high speed disperser (HSD). This was then ground in a media mill for 4 hours. The dispersion was then purified by diluting 281 g of material with 141 g deionized water, and excess solvent was removed via an ultrafiltration process to obtain less than 1.0 wt% solvent (other than water) and An 18.37 wt% pigment solids dispersion having an average particle size of 79 nm was obtained.

Comparative dispersion preparation 3-self-dispersing black pigment (CDP3)
Prepared by the method described in Example 3 of previously incorporated US Pat. No. 6,852,156.

Polymer Dispersion Testing For the ISD, the ratio of hydrophilic and hydrophobic compositions is shown in the table. For each of the items, polymeric dispersants and polyurethane ink additives were prepared by the examples listed above or similar synthetic methods. Similarly, the dispersion and ink were prepared by the procedure described above. For random polymers, weight ratios are used; for block polymers, molar ratios of monomer components are used.

  Table 1 shows the salt stability test for the ISD polymeric dispersant containing carbon black pigment. For each of these polymeric dispersants, a stable dispersion was prepared in a manner similar to Dispersion Preparation 1. The pigment was carbon black. The results for inks containing SDP dispersants and conventional dispersants are also shown.

  The selected polyurethane ink additive may have the properties of an ISD dispersant. Dispersions were prepared in a manner similar to that described for the 92/8 dispersant system.

  The results in Table 1 show that when black pigment is formulated, seven ISD polymers meet the salt test criteria for the present invention. Comparing the 90/10, 92/8 and 94/6 ISDs, the hydrophilic component is reduced in this set and the salt stability test indicates that the polymeric dispersant precipitates at lower salt concentrations. Indicates deafness. The two polyurethanes tested as dispersants also meet the salt stability test as ISD. The SDP material also meets the salt test criteria but does not have a polymeric dispersant. Conventional dispersants are formulations that are typically commercially available for pigments for inks. Note that conventional dispersants do not meet the criteria of the present invention for salt stability testing. That is, these dispersions do not precipitate after 24 hours at high salt concentrations.

Test Ink Sample Printing Test examples were printed in the following manner unless otherwise indicated. Printing for ISD ink was performed with a piezo Epson 980 printer (Epson America Inc, Long Beach, Calif.) Using a black print head with a nominal resolution of 720 dots / inch on plain paper and 1440 dpi on glossy paper. It was. Printing was performed in a standard print mode by software selection. The print test was also conducted with a thermal ink jet printer, HP6122. Optical density and saturation were measured using a Greytag-Macbeth SpectroEye instrument (Greytag-Macbeth AG, Regensdorf, Switzerland). The plain paper OD value is the average of readings from prints on three different plain papers: Hammermill Copy Plus paper, Hewlett-Packard Office paper and Xerox 4024 paper. The glossy paper results are from prints formed using Epson Glossy Photo paper, SO41286. Epson Photo Quality ink jet paper (matte paper) SO41062 was also printed. Gloss was measured using a BYK-Gardner Micro-Tri-Gloss gloss meter (Gardner Co. (Pompano Beach, Florida)). The ink prepared using ISD was printed and the optical properties were measured. Black and other pigmented inks were prepared using the vehicles and ISD listed in Table 2. The optical density was tested with three different types of plain paper. All polymer formulations were based on 2-pyrrolidone formulations that were 1c, 2b, 3b and 5, respectively.

  ISD formulated inks that do not contain polyurethane ink additives have better optical density than comparative inks that contain conventional dispersants. For the series of ISD 90/10, 92/8, and 94/6, the optical density increases as the hydrophilicity decreases. For both ISD 92/8 and 94/6, the optical density was good at both 3 and 6% loading.

Preparation of an Ink Containing an ISD Dispersant and a Polyurethane Ink Additive The ink of the present invention has the following ingredients in a pigment dispersion in the same manner as the comparative ink example described above, except that the polyurethane ink additive is added. It was formed by adding. The dispersant used was a 92/8 dispersant described as ISD dispersant 2b. All amounts shown are weight percent.

  The raw material for the magenta pigment was EO2 made by Clariant (Charlotte, NC), and the raw material for the black pigment was Nipex 180IQ made by DeGussa (Parsippany, NJ).

Each of the inks shown in Tables 3-6 was printed and the optical properties were measured. The 100% and 80% displays for gloss and DOI data are 100% and 80% coverage, respectively.
Magenta

  For some of the inks of the present invention shown above, the data item list that only one page was printed indicates that the ink formulation was not stable or that other problems with printing occurred. Show. These formulations were not further optimized to minimize this effect. However, the data above show that gloss and DOI were not measurable, but the optical density is still within the required range. The comparative ink had comparable optical density results, indicating that the polyurethane ink additive had no adverse effect on the optical density.

  In terms of gloss and DOI, the ink of the present invention at 1% loading of polyurethane ink additive was significantly better than the comparative ink. For example, PUD2 had a gloss of 92.1 versus an average of about 61 for the comparative ink.

  Only one data item indicated that the ink could not be printed. This was a 3% PUD ink additive level. This is a wide range of pigment and polyurethane ink additive formulations. The comparative ink had comparable optical density results, indicating that the polyurethane ink additive had no adverse effect on the optical density.

  For inks containing ISD dispersed pigments and polyurethane ink additives, gloss and DOI were improved compared to ISD preparations without polyurethane additive.

  In order to compare the inks of the present invention containing an ISD dispersant and a polyurethane ink additive, a black ink containing an ISD dispersant and a polymeric additive equivalent to the ISD dispersant was prepared. The ISD dispersant is in this case the same as the polyurethane ink additive. For each ink, a pigment dispersion was prepared using conventional dispersion techniques. The ink was then prepared by adding other formulation ingredients including a polymeric ink additive.

  The inks of the present invention with polyurethane ink additive levels of 1.5, 3, 4.5 and 6% by weight had significantly better gloss at both 809 and 100% coverage. The DOI was better at the 1.5 and 3% levels. This indicates that at 4.5 and 6% polymeric ink additive loading, the DOI was not measurable or the ink had other printing problems that resulted in cloudiness. obtain.

Examples of Crosslinked Polyurethane Ink Additives Inks of the present invention were prepared and tested on paper and printed on textiles. Textile printing was performed according to the method described in US Patent Application Publication No. 20050215663. Magenta, cyan and yellow inks were prepared and tested. For textile printing on cotton and polycotton, the textile was fused prior to measurement. 7409 at 160 ° C for 2 minutes and 419 at 190 ° C for 2 minutes.

  The composition of the ink is as follows.

Comparison with conventional polymerized dispersion inks containing PUD ink additives.
Inks were prepared with ETEGMA // BZMA // MAA dispersant as described in Comparative Dispersant Polymer 1. Inks were prepared with and without the polyurethane ink additive.

The ink composition for these tests was in weight percent.
3.75% pigment (Nipex 180IQ)
1.875% acrylic polymer (solid); dispersant.
2.00% PUD ink additive 4
9.00% 2-pyrrolidinone 2.00% Isopropanol alcohol 0.20% Neopental alcohol 5.00% Liponics-EG1 (LEG)
0.20% Proxel GXL
75.975% water

PUD ink additives significantly reduce OD, but gloss and DOI change little. This conventional dispersed pigment does not have the improved combination that ISD and polyurethane ink additives have.
In addition, this invention includes the following invention including a claim.
1. An aqueous pigment inkjet ink comprising polyurethane, an aqueous pigment dispersion in an aqueous vehicle, wherein the aqueous pigment dispersion comprises a polymeric ionic dispersant and a pigment;
(A) the polymeric ionic dispersant is physically adsorbed on the pigment;
(B) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle;
(C) The average particle size of the dispersion is less than about 300 nm, and (d) 24 hours after addition when 3 drops of ink are added to about 1.5 g of about 0.20 molar salt aqueous salt solution. When observed, the pigment precipitates from the aqueous salt solution; and
The polyurethane is
a). A urea-terminated polyurethane wherein the weight fraction of the urea-terminated polyurethane part of the polyurethane is at least 2% by weight relative to the urethane resin; and b). A crosslinked polyurethane in an inkjet ink in an amount of from about 0.5% to about 30% by weight, based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is about An aqueous pigment inkjet ink selected from the group consisting essentially of greater than 1% and less than about 50%.
2. The polyurethane has the general structure (I):

（Ｒ₁＝ジイソシアネートからのアルキル、置換アルキル、置換アルキル／アリールであり、
Ｒ₂＝ジオールからのアルキル、置換／分岐アルキルであり、
Ｒ₃＝水素；アルキル；アミン末端封止基からの非イソシアネート反応性置換アルキル、イソシアネート反応性置換アルキル、または分岐アルキルであり；
Ｒ₄＝水素；アルキル；アミン末端封止基からの非イソシアネート反応性置換アルキル、イソシアネート反応性置換アルキル、または分岐アルキルであり；
イソシアネート反応性基はヒドロキシル、カルボキシル、メルカプトまたはアミドから選択され；
ｎ＝２〜３０であり；
ならびに、Ｒ₂＝Ｚ₁、Ｚ₂またはＺ₃であり、かつ、少なくとも１つのＺ₁またはＺ₃および少なくとも１つのＺ₂がポリウレタン組成物中に存在していなければならず；

(R ₁ = alkyl from diisocyanate, substituted alkyl, substituted alkyl / aryl,
R ₂ = alkyl from diol, substituted / branched alkyl,
R ₃ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
R ₄ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
The isocyanate-reactive group is selected from hydroxyl, carboxyl, mercapto or amide;
n = 2-30;
And R ₂ = Z ₁ , Z ₂ or Z ₃ and at least one Z ₁ or Z ₃ and at least one Z ₂ must be present in the polyurethane composition;

ｐは１以上であり、
ｐ＝１である場合、ｍは２以上〜約３６であり、
ｐ＝２超である場合、ｍは２以上〜約１２であり；
Ｒ₅、Ｒ₆＝水素、アルキル、置換アルキル、アリールであり；ここで、Ｒ₅はＲ₅およびＲ₆置換メチレン基の各々と同一または異なっており、Ｒ₅とＲ₅またはＲ₆とは結合して環構造を形成していることが可能であり；
Ｚ₂は、イオン基で置換されたジオールであり；
Ｚ₃は、ポリエステルジオール、ポリカーボネートジオール、ポリエステルカーボネートジオールおよびポリアクリレートジオールから選択される；）
の少なくとも１種の化合物を含む尿素末端ポリウレタンであり、
構造Ｉは尿素末端封止成分を示すと共に、構造ＩＩは、構造Ｉ用の構築ブロックであるジオールおよび／またはポリエーテルジオールを示す、１に記載のインクジェットインク。
３．前記尿素末端ポリウレタンが、構造ＩＩ（式中、ｍ＝３〜３６である）のものである、２に記載のインクジェットインク。
４．前記尿素末端ポリウレタンが、構造ＩＩ（式中、ｐは２以上であり、ｍ＝３〜１２である）のものである、２に記載のインクジェットインク。
５．前記ポリウレタンが、総インク組成物の重量に基づいて約０．１〜約１２重量％である、１に記載のインクジェットインク。
６．前記ポリウレタンが、総インク組成物の重量に基づいて約０．２〜約１０重量％である、１に記載のインクジェットインク。
７．前記ポリウレタンが、総インク組成物の重量に基づいて約０．２５〜約８重量％である、１に記載のインクジェットインク。
８．インクの総重量に基づいて約０．１〜約１０重量％の顔料、約０．５〜約６の顔料対分散剤の重量比、２５℃で約２０ｄｙｎｅ／ｃｍ〜約７０ｄｙｎｅ／ｃｍの範囲の表面張力、および、２５℃で約３０ｃＰ未満の粘度を有する、１に記載のインクジェットインク。
９．前記分散剤は、顔料を水性ビヒクルに安定的に分散させ、
（ｃ）分散体の平均粒径は約３００ｎｍ未満であり、ならびに
（ｄ）３滴のインクを約１．５ｇの約０．２０モル塩の塩水溶液に添加した場合に、添加後２４時間観察したときに、前記顔料が前記塩水溶液から析出し；および添加後２４時間観察したときに、前記顔料が前記塩水溶液から析出する、１に記載のインクジェットインク。
１０．前記高分子イオン性分散剤が親水性部分および疎水性部分を含み、前記疎水性部分が主たる部分である、１に記載のインクジェットインク。
１１．前記高分子イオン性分散剤が、１種または複数種の親水性モノマーおよび１種または複数種の疎水性モノマーのコポリマーであり、このコポリマーが約３００超〜約３０，０００未満の数平均分子量を有する、１０に記載の高分子イオン性分散剤分散体。
１２．前記顔料対高分子イオン性分散剤の重量比が約０．５〜約６である、１に記載のインクジェットインク。
１３．前記水性ビヒクルが、水および少なくとも１種の水和性の溶剤の混合物である、１に記載のインクジェットインク。
１４．少なくとも１種のシアンインク、少なくとも１種のマゼンタインクおよび少なくとも１種のイエローインクを含み、少なくとも１種のインクが１に記載の水性顔料インクジェットインクであるインクセット。
１５．（ａ）デジタルデータ信号に応答性のインクジェットプリンタを提供するステップ；
（ｂ）印刷されるべき基材を前記プリンタに装填するステップ；
（ｃ）１４に記載のインクを前記プリンタに装填するステップ；および
（ｄ）デジタルデータ信号に応答して、インクまたはインクジェットインクセットを用いて基材上に印刷するステップ
を含む基材上へのインクジェット印刷方法。
１６．１５に記載のインクセットが前記プリンタに装填される、５に記載の基材上へのインクジェット印刷方法。

p is 1 or more,
when p = 1, m is from 2 to about 36;
if p = 2, m is greater than or equal to 2 and about 12;
R ₅ , R ₆ = hydrogen, alkyl, substituted alkyl, aryl; where R ₅ is the same as or different from each of the R ₅ and R ₆ substituted methylene groups, and R ₅ and R ₅ or R ₆ are They can be joined to form a ring structure;
Z ₂ is a diol substituted with an ionic group;
Z ₃ is selected from polyester diol, polycarbonate diol, polyester carbonate diol and polyacrylate diol;)
A urea-terminated polyurethane comprising at least one compound of
2. The inkjet ink of 1, wherein structure I represents a urea end-capping component and structure II represents a diol and / or polyether diol that is a building block for structure I.
3. The inkjet ink of 2, wherein the urea-terminated polyurethane is of structure II (where m = 3 to 36).
4). The inkjet ink according to 2, wherein the urea-terminated polyurethane is of the structure II (wherein p is 2 or more and m = 3 to 12).
5. The inkjet ink of 1, wherein the polyurethane is from about 0.1 to about 12% by weight, based on the weight of the total ink composition.
6). The inkjet ink of 1, wherein the polyurethane is from about 0.2 to about 10% by weight, based on the weight of the total ink composition.
7). The inkjet ink of 1, wherein the polyurethane is from about 0.25 to about 8% by weight, based on the weight of the total ink composition.
8). From about 0.1 to about 10% by weight pigment, based on the total weight of the ink, from about 0.5 to about 6 pigment to dispersant weight ratio, ranging from about 20 dyne / cm to about 70 dyne / cm at 25 ° C. The ink-jet ink of claim 1, having a surface tension and a viscosity of less than about 30 cP at 25 ° C.
9. The dispersant stably disperses the pigment in the aqueous vehicle,
(C) The average particle size of the dispersion is less than about 300 nm, and (d) when 3 drops of ink are added to about 1.5 g of about 0.20 molar salt aqueous solution, observed 24 hours after addition. The inkjet ink according to 1, wherein the pigment precipitates from the aqueous salt solution; and the pigment precipitates from the aqueous salt solution when observed for 24 hours after the addition.
10. 2. The inkjet ink according to 1, wherein the polymeric ionic dispersant includes a hydrophilic portion and a hydrophobic portion, and the hydrophobic portion is a main portion.
11. The polymeric ionic dispersant is a copolymer of one or more hydrophilic monomers and one or more hydrophobic monomers, the copolymer having a number average molecular weight of greater than about 300 to less than about 30,000. 10. The polymer ionic dispersant dispersion according to 10.
12 2. The inkjet ink of 1, wherein the weight ratio of the pigment to the polymeric ionic dispersant is from about 0.5 to about 6.
13. The inkjet ink of 1, wherein the aqueous vehicle is a mixture of water and at least one hydrating solvent.
14 An ink set comprising at least one cyan ink, at least one magenta ink, and at least one yellow ink, wherein the at least one ink is the water-based pigment inkjet ink according to 1.
15. (A) providing an inkjet printer responsive to a digital data signal;
(B) loading the substrate to be printed into the printer;
(C) loading the ink of claim 14 into the printer; and (d) printing on the substrate using the ink or inkjet ink set in response to the digital data signal onto the substrate. Inkjet printing method.
16. The ink-jet printing method on a substrate according to 5, wherein the ink set according to 16.15 is loaded into the printer.

Claims (3)

An aqueous pigment inkjet ink comprising polyurethane and an aqueous pigment dispersion in an aqueous vehicle comprising:
The aqueous pigment dispersion includes a polymeric ionic dispersant and a pigment,
(A) the polymeric ionic dispersant is physically adsorbed on the pigment;
(B) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle;
(C) The average particle size of the aqueous pigment dispersion is less than 300 nm,
The polymeric ionic dispersant is a copolymer of one or more hydrophilic monomers and one or more hydrophobic monomers, the copolymer having a number average molecular weight of greater than 300 to less than 30,000 ,
The polyurethane is
a). The weight fraction of the urea-terminated polyurethane part of the polyurethane, determined by dividing the mass of the amine chain terminator by the sum of the other polyurethane components containing the chain terminator, is 2% by weight of the total weight of the urethane resin. A urea-terminated polyurethane that is 6.8% by weight,
And b). A crosslinked polyurethane in an inkjet ink in an amount of greater than 0.5% to 30% by weight, based on the total weight of the aqueous ink, wherein the amount of crosslinking in the crosslinked polyurethane is greater than 1% as measured by a THF insoluble content test. And less than 50% crosslinked polyurethane
Consisting of
The end of the polyurethane has a general structure (I):

(R ₁ = alkylene from diisocyanate, substituted alkylene, arylene, or substituted arylene;
R ₂ = Z ₁ , alkylene derived from Z ₂ or Z ₃ , or substituted alkylene,
R ₃ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
R ₄ = hydrogen; alkyl; non-isocyanate reactive substituted alkyl, isocyanate reactive substituted alkyl, or branched alkyl from an amine end-capping group;
The isocyanate-reactive group is selected from hydroxyl, carboxyl, mercapto or amide;
n = 2-30;
And R ₂ is as defined above and at least one Z ₁ or Z ₃ and at least one Z ₂ must be present in the polyurethane composition;

p is 1 or more,
When p = 1, m is 2-36,
if p = 2, m is 2-12;
R ₅ , R ₆ = hydrogen, alkyl, substituted alkyl, aryl; where R ₅ is the same as or different from each of the R ₅ and R ₆ substituted methylene groups, and R ₅ and R ₅ or R ₆ are They can be joined to form a ring structure;
Z ₂ is a diol substituted with an ionic group;
Z ₃ is selected from polyester diol, polycarbonate diol, polyester carbonate diol and polyacrylate diol;)
At least one compound of
A water-based pigmented inkjet ink where structure I represents a urea end-capping component and structure II represents a diol that is a building block for structure I. The inkjet ink of claim 1, wherein the urea terminated polyurethane is of structure II where m = 3 to 36. The inkjet ink of claim 1, wherein the urea-terminated polyurethane is of structure II where p is 2 or greater and m = 3-12.