阅读说明：本技术 用于喷墨打印的墨组合物 (Ink composition for inkjet printing ) 是由 A·基里亚库 J·哈里斯 D·A·P·福特斯 于 2018-05-11 设计创作，主要内容包括：本发明公开了一种墨组合物,其包含一种或多种挥发性有机溶剂和一种或多种着色剂。该墨组合物包括具有一种或多种聚合物的粘合剂树脂和用于使粘合剂树脂的聚合物交联的金属交联剂。一种或多种聚合物包含用于使主粘合剂树脂的聚合物与金属交联剂交联的配位基团。墨组合物可用于喷墨打印例如连续喷墨打印,并且可以适于在经历工业蒸煮和灭菌过程的基材上产生耐用的代码。墨也可提供打印机的热稳定性和可靠性。(An ink composition includes one or more volatile organic solvents and one or more colorants. The ink composition includes a binder resin having one or more polymers and a metal crosslinking agent for crosslinking the polymers of the binder resin. The one or more polymers comprise a coordinating group for crosslinking the polymer of the primary binder resin with the metal crosslinker. The ink compositions can be used for ink jet printing, such as continuous ink jet printing, and can be suitable for producing durable codes on substrates that are subjected to industrial cooking and sterilization processes. The ink may also provide thermal stability and reliability of the printer.)

1. An ink composition comprising one or more volatile organic solvents and one or more colorants, said ink being characterized in that it comprises a main binder resin comprising one or more polymers and a metal crosslinker,

wherein the one or more polymers comprise a coordinating group for crosslinking the polymer of the primary binder resin with the metal crosslinker, and the content of the coordinating group is from 1.7 to 28 wt% based on the total weight of the primary binder resin, and wherein the primary binder resin is present at least 1.5 wt% based on the total weight of the ink composition.

2. The ink composition according to claim 1, wherein the content of the coordinating group is 2 to 22 wt%.

3. The ink composition according to any one of the preceding claims, wherein the coordinating group is selected from hydroxyl, carboxyl and amino.

4. The ink composition of any of the preceding claims, wherein the coordinating group is a hydroxyl group.

5. The ink composition according to claim 4, wherein the hydroxyl value is from 60 to 330mg KOH/g.

6. The ink composition according to any one of the preceding claims, wherein the primary binder resin is selected from the group consisting of cellulose resins, acrylic resins, vinyl resins, polyamides, polyesters and polyurethanes.

7. The ink composition according to claim 6, wherein the primary binder resin is a cellulose resin.

8. The ink composition according to claim 7, wherein the cellulose resin is cellulose acetate butyrate.

9. The ink composition according to any one of the preceding claims, wherein the molecular weight, e.g. weight average molecular weight (Mw), of the primary binder resin is from 1,500 to 50,000.

10. The ink composition of any one of the preceding claims, wherein the primary binder resin is present at 1.5 to 25 wt% based on the total weight of the ink composition.

11. The ink composition of any of the preceding claims, wherein the metallic crosslinker is a titanium or zirconium containing species.

12. The ink composition of claim 11, wherein the metal crosslinker is selected from the group consisting of titanium acetylacetonate, titanium butyl phosphate, titanium triethanolamine, titanium lactate, zirconium diethyl citrate, zirconium acetate, and zirconium propionate.

13. The ink composition of claim 12, wherein the metal crosslinker is zirconium propionate.

14. The ink composition of any one of the preceding claims, wherein 0.1 to 5 wt% of the metal crosslinker is provided.

15. The ink composition of any one of the preceding claims, wherein the ink composition further comprises a carboxyl resin.

16. The ink composition of claim 15, wherein the carboxyl resin is a Styrene Maleic Anhydride (SMA) -based polymer comprising carboxyl functional groups.

17. The ink composition according to claim 15 or 16, wherein the carboxylic resin has an acid value of 60 to 500mg KOH/g.

18. The ink composition of any one of claims 15-17, wherein the carboxyl resin is present at 0.1 to 10 wt% based on the total weight of the ink composition.

19. The ink composition of any one of claims 15-18, wherein the carboxyl resin comprises a polymer having a molecular weight, e.g., a weight average molecular weight (Mw), of 1,500 to 50,000.

20. The ink composition according to any one of claims 15 to 19, wherein the primary binder comprises a polymer having a higher molecular weight, e.g. a higher weight average molecular weight, than the polymer of the carboxyl resin.

21. The ink composition according to any one of claims 15 to 20, wherein the primary binder resin is present in the composition in an amount greater than the amount of the carboxyl resin.

22. The ink composition of any one of the preceding claims, wherein the ink composition further comprises a third resin.

23. The ink composition according to claim 22, wherein the third binder resin has a lower molecular weight, e.g., a weight average molecular weight, than the carboxyl resin.

24. The ink composition according to claim 22 or 23, wherein the third binder resin has a lower molecular weight, weight average molecular weight, than the main binder resin.

25. The ink composition according to any one of claims 22 to 24, wherein the molecular weight, e.g., weight average molecular weight (Mw), of the third binder resin is 100 to 1,000.

26. The ink composition of any one of claims 22-25, wherein the third binder resin comprises carboxyl functional groups.

27. The ink composition according to claim 26, wherein the third binder resin has an acid value of 60 to 500mg KOH/g.

28. The ink composition of any one of claims 22-27, wherein the third binder resin is present at 0.1 to 1 wt% based on the total weight of the ink composition.

29. The ink composition according to any one of claims 22 to 28, wherein the third binder resin is a rosin resin.

30. The ink composition of claim 29, wherein the rosin resin is selected from the group consisting of hydrogenated rosin resins, polymerized rosin resins, esters of rosin resins, phenolic modified rosin resins, and maleic modified rosin resins.

31. The ink composition of claim 30, wherein the rosin resin is a maleic modified rosin resin.

32. The ink composition according to any one of the preceding claims, wherein at least some of the polymers of the primary binder resin are crosslinked by the metal crosslinker.

33. A printing method comprising the steps of: providing a composition according to any one of claims 1 to 32, and depositing the ink composition onto a substrate, and optionally allowing the deposited composition to dry.

34. An ink cartridge comprising the composition of any one of claims 1 to 32.

35. A printing method comprising the steps of: providing an ink cartridge comprising the ink composition of claim 34; ejecting droplets of the ink composition from the cartridge onto a substrate to provide a deposited composition, and optionally allowing the deposited composition to dry.

36. A substrate comprising a printed deposit made according to the method of claim 35.

37. A printed deposit comprising one or more colorants, characterized in that said printed deposit comprises a primary binder resin comprising one or more polymers and a metallic crosslinker crosslinking said primary binder resin,

wherein the one or more polymers comprise a coordinating group for crosslinking the polymer of the primary binder resin with the metal crosslinker, and the content of the coordinating group is from 1.7 to 28 wt% based on the total weight of the primary binder resin, and wherein the primary binder resin is present at least 1.5 wt% based on the total weight of the ink composition.

Technical Field

The present invention relates to ink compositions, in particular for ink jet printing, such as continuous ink jet printing.

Background

In the field of industrial coding and marking codes, date and traceability information is directly applied to products and/or packaging. A common technique is continuous inkjet printing, where selective charging and deflection of ink droplets is used to mark various substrates.

In food packaging applications it is common that the final packaged and printed product undergoes additional processing steps to extend the shelf life of the product before reaching the consumer, examples of such processes being deep freezing, cooking or sterilization.

In the food packaging industry, printed substrates are often subjected to a retort (or steam sterilization process) to both sterilize the package and partially cook the contents of the package. Since the package may come into contact with an adjacent package, it is possible to "transfer" or "offset" the printed code to the adjacent package, particularly during autoclaving. In order for the code not to be transferred, the dried ink must remain rigid and non-tacky at high temperatures.

Some known methods of providing inks that are stable under retort conditions are discussed in CN 101987932A, CN 101987931a and CN 102140276 a. There is no disclosure that the inks in these applications resist offset during cooking.

CN 101987932A discusses an ink jet ink composition having one or more organic solvents, resins, and colorants, a viscosity of 2.8 to 6.2CP at 25 deg.C, an electrical conductivity of 500-1,500. mu.S at 20 deg.C, and a surface tension of 27-30 Dyn/cm. The ink is described as resistant to steam treatment.

CN 101987931a discusses an ink jet ink composition having 11 to 26 wt% of a polymer resin, 2 to 10 wt% of a colorant, 65 to 75 wt% of a solvent, and 1 to 5 wt% of an antistatic agent. The ink is described as being resistant to fading upon high temperature baking.

CN 102140276a discusses an inkjet ink composition with one or more organic solvents, resins, colorants and auxiliaries, characterized by a polyurethane as the main binder. The viscosity of the ink at 25 ℃ is 2 to 10CP, the conductivity at 20 ℃ is 500-2,000. mu.S and the surface tension is 27-35 Dyn/cm. The ink is described as resistant to steam treatment.

It is desirable that the prints be durable, have good adhesion and rub resistance, and have good contrast on the substrate. Inks with these properties are desirable in food packaging applications due to their fast drying times, ability to produce clear marks on non-uniform surfaces, and ability to have good adhesion on various package types.

It is also desirable that ink formulations used for coding and marking have good thermal stability properties so that the physical properties (e.g., viscosity and particle size) do not change significantly during ink storage or during operation of the printer. This thermal stability (in both hot and cold environments) is necessary to ensure reliable printer operation so that acceptable print quality and on-substrate performance can be ensured in all customer environments.

It is an object of the present invention to provide an ink composition having some of the desirable features described above. In particular, it is an object of the present invention to provide an ink that survives the cooking process and does not transfer to adjacent packages during the process.

An alternative and/or additional object of the present invention is to overcome or solve the problems with the prior art ink jet ink compositions, or at least to provide a commercially useful alternative to the prior art ink jet ink compositions.

Disclosure of Invention

The present invention seeks to provide solvent-based ink compositions, in particular ink compositions for inkjet printing, such as continuous inkjet printing, which are suitable for producing durable codes on substrates subjected to industrial cooking and sterilization processes. The present invention can also provide thermal stability and reliability of the printer.

Accordingly, in one aspect, the present invention provides an ink composition comprising one or more volatile organic solvents and one or more colorants. The ink jet ink composition includes a binder resin including one or more polymers and a metal crosslinker for crosslinking the polymers of the binder resin. The one or more polymers comprise a coordinating group for crosslinking the polymer of the primary binder resin with the metal crosslinker. The content of the coordinating group is 1.7 to 28 wt% based on the total weight of the main binder resin. Preferably, the primary binder resin is present in at least 1.5 wt% based on the total weight of the ink composition.

In another aspect, the present invention provides printed deposits formed from the ink compositions of the present invention. The printed deposit comprises one or more colorants and includes a binder resin comprising one or more polymers and a metallic crosslinker crosslinking the polymers of the binder resin.

In this manner, the present invention provides ink compositions and/or printed deposits that can withstand the retort process without shifting to adjacent products.

The ink composition may further include a carboxyl resin for reducing the viscosity of the ink composition. The ink composition may further include a third binder resin for increasing solubility of the ink composition. Typically, a third binder is present with the carboxyl resin.

In this manner, the present invention provides an ink having desirable durability as well as good thermal stability and printer reliability.

The ink composition is compatible with components of an ink jet printer, particularly a continuous ink jet printer. The ink composition is suitable for direct application to products and/or product packaging to achieve high quality images.

These and other aspects and embodiments of the invention are described in further detail below.

Drawings

Fig. 1 is a graph of ejection stability trace data of the ink composition (ink 3) of the present invention measured by tracing the printer nozzle movement from the top down angle.

Fig. 2 is a graph of the ejection stability trace data of the ink composition of the present invention (ink 4) measured by tracing the printer nozzle movement from the top down angle.

Detailed Description

The present invention provides ink compositions comprising one or more volatile organic solvents and one or more colorants. The ink includes a primary binder resin comprising one or more polymers and a metal crosslinker. The one or more polymers comprise a coordinating group for crosslinking the polymer of the primary binder resin with the metal crosslinker. Typically, the content of the coordinating group is 1.7 to 28 wt% based on the total weight of the main binder resin.

Preferably, the ink compositions described herein have a viscosity at 25 ℃ of about 0.5 to 7mpa.s, more preferably 1 to 5.5 mpa.s. Preferably, the ink composition described herein has a viscosity at 25 ℃ of less than 7mpa.s, more preferably less than 5.5 mpa.s. Preferably, the ink composition described herein has a viscosity at 25 ℃ of more than 0.5mpa.s, more preferably more than 1mpa.s, even more preferably more than 3 mpa.s. The viscosity of the ink composition may be within a range selected from the upper and lower limits of the above amounts. The viscosity of the composition can be measured using a viscometer, such as a Brookfield DV-11+ viscometer.

Preferably, the ink composition described herein has a surface tension at 25 ℃ of 20 to 50mN/m, more preferably 25 to 40 mN/m. The surface tension of the composition can be measured using equipment such as a du Nouy ring tensiometer or using the pendant drop method on a KSV Cam 200 optical tensiometer.

Solvent(s)

The ink composition comprises at least one volatile organic solvent. Any volatile organic solvent that can dissolve the resin is suitable. The solvent may be selected from ketones, alcohols, esters, glycols, glycol ethers. The solvent may be a mixture of solvents.

The expression "volatile organic solvent" is generally understood to mean that the solvent has an evaporation rate of greater than 0.5 (preferably greater than 1.5, more preferably greater than 2), the evaporation rate based on n-butyl acetate being equal to 1 on a scale. In other words (see below), the solvent has a volatility index according to the NF T30-301 standard of more than 0.5, preferably more than 1.5, more preferably more than 2. The rate of evaporation or volatilization can be measured at a temperature of 25 ℃ and a pressure of 1.013 kPa.

Volatile organic solvents are short drying times because the organic solvent evaporates rapidly (e.g., as compared to aqueous solvents). Volatile organic solvents enhance the adhesion of the ink composition due to their ability to penetrate to semi-porous or non-porous substrates. The drying time of the ink depends on the ambient temperature, pressure and humidity, e.g. 25 ℃, 1.013kPa and Q70% humidity. Preferably, the ink dries within 0.1 to 3 seconds.

For example, the volatile organic solvent may be selected from the group consisting of acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, cyclohexanone, ethanol, isopropanol, n-propanol, isobutanol, n-butanol, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, n-pentyl acetate, isoamyl acetate, isobutyl isobutyrate, ethylene glycol, propylene glycol, 1-methoxy-2-propanol and 1-methoxy-2-propyl acetate.

In one embodiment, the volatile organic solvent is not an ester solvent.

The ink composition may also comprise water. For example, if present, water may be present at less than 10 wt%, based on the total weight of the ink composition, preferably, water is present at less than 5 wt%.

The composition may be a non-aqueous composition.

Preferably, the volatile organic solvent is present in the composition at 10 to 95 wt%, more preferably 40 to 90 wt%, most preferably 70 to 90 wt% by weight, based on the total weight of the ink composition.

Preferably, the volatile organic solvent is present at less than 95 wt%, more preferably less than 93 wt%, even more preferably less than 91 wt%, based on the total weight of the ink composition. Preferably, the organic solvent is present at greater than 10 wt%, preferably greater than 40 wt%, even more preferably greater than 70 wt%, based on the total weight of the ink composition. The solvent may be present in an amount within a range selected from the upper and lower limits of the amounts recited above.

Preferred volatile organic solvents are ketones, such as methyl ethyl ketone. Preferably, a ketone, such as methyl ethyl ketone, is present in 10 to 90 wt%, more preferably 50 to 85 wt%, most preferably 65 to 80 wt%, based on the total weight of the ink composition.

Preferably, a ketone, such as methyl ethyl ketone, is present at less than 90 wt%, more preferably less than 85 wt%, even more preferably less than 80 wt%, based on the total weight of the ink composition. Preferably, a ketone such as methyl ethyl ketone is present at greater than 10 wt%, preferably greater than 50 wt%, even more preferably greater than 65 wt%, based on the total weight of the ink composition. The ketone may be present in an amount within a range selected from the upper and lower limits of the amounts described above.

Preferably, when the volatile organic solvent is a mixture, the mixture comprises an alcohol, such as C_1-6Alkyl alcohols, for example ethanol or isopropanol. Preferably, the alcohol is present in 5 to 20 wt%, more preferably 10 to 15 wt%, based on the total weight of the ink composition.

Preferably, the alcohol is present at less than 20 wt%, more preferably less than 15 wt%, based on the total weight of the ink composition. Preferably, the alcohol is present at greater than 5 wt%, preferably greater than 10 wt%, based on the total weight of the ink composition. The alcohol may be present in an amount within a range selected from the upper and lower limits of the amounts recited above.

Preferably, when the volatile organic solvent is a mixture, the mixture comprises a ketone and an alcohol, e.g. C_1-6An alkyl alcohol. For example, the mixture comprises methyl ethyl ketone and ethanol or isopropanol.

In the printed deposit, the solvent is at least partially evaporated. In this case, no solvent or only traces of solvent may be present in the printed deposit.

Coloring agent

The ink composition comprises a colorant, such as a dye or a pigment. Preferably, the colorant is a pigment. The pigment may be in the form of a dispersion in the composition. The pigment may be an inorganic pigment or an organic pigment.

Preferably, the average particle size of the pigment is less than 1 μm. The average particle diameter referred to herein is the Z-average particle diameter calculated using dynamic light scattering. This is the intensity weighted average hydrodynamic size of the collection of particles.

For example, the inorganic pigment may be selected from titanium oxide (e.g., titanium dioxide), iron oxide, and carbon black prepared by known methods (e.g., contact, furnace, and heat treatment).

For example, the organic pigment may be selected from azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments), polycyclic pigments (such as phthalocyanine, perylene, Perinone, anthraquinone, quinacridone, dioxazine, thioindigo, isoindolinone, and quinophthalone pigments), dye-type chelate pigments (such as basic dye-type chelate pigments and acidic dye-type chelate pigments), nitro pigments, nitroso pigments, and aniline black.

Preferably, the inorganic pigment is carbon black. Carbon blacks that can be used in black inks include carbon blacks manufactured by Mitsubishi Chemical Corporation, e.g., No.2300, No.900, MCF 88, No.33, No.40, No.45, No.52, MA7, MA 8, MA 100, and No. 2200B; carbon blacks manufactured by Columbian Carbon co., ltd., such as Raven5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, and Raven 700; carbon blacks manufactured by Cabot corporation, for example, Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch700, Monarch800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, and Monarch 1400; and carbon blacks manufactured by Degussa, for example, pigment carbon black FW 1, pigment carbon black FW 2V, pigment carbon black FW 18, pigment carbon black FW 200, pigment carbon black S150, pigment carbon black S160, pigment carbon black S170, Printex 35, Printex U, Printex V, Printex 140U, ultrablack 6, ultrablack 5, ultrablack 4A, and ultrablack 4.

Pigments for yellow ink include c.i. pigment yellow 1, c.i. pigment yellow 2, c.i. pigment yellow 3, c.i. pigment yellow 12, c.i. pigment yellow 13, c.i. pigment yellow 14, c.i. pigment yellow 16, c.i. pigment yellow 17, c.i. pigment yellow 73, c.i. pigment yellow 74, c.i. pigment yellow 75, c.i. pigment yellow 83, c.i. pigment yellow 93, c.i. pigment yellow 95, c.i. pigment yellow 97, c.i. pigment yellow 98, c.i. pigment yellow 109, c.i. pigment yellow 110, c.i. pigment yellow 114, c.i. pigment yellow 128, c.i. pigment yellow 129, c.i. pigment yellow 138, c.i. pigment yellow 150, c.i. pigment yellow 151, c.i. pigment yellow 154, c.i. pigment yellow 155, c.i. pigment yellow 180, c.i. pigment yellow 185, and c.i. pigment yellow 185.

The pigment for magenta ink includes c.i. pigment red 5, c.i. pigment red 7, c.i. pigment red 12, c.i. pigment red 48(Ca), c.i. pigment red 488 (Mn), c.i. pigment red 57(Ca), c.i. pigment red 57:1, c.i. pigment red 112, c.i. pigment red 122, c.i. pigment red 123, c.i. pigment red 168, c.i. pigment red 184, c.i. pigment red 202, c.i. pigment red 176, c.i. pigment red 254, c.i. pigment red 255, c.i. pigment red 272, c.i. pigment red 254, c.i. pigment orange 64, and c.i. pigment orange 73.

The pigment for cyan ink includes c.i. pigment blue 1, c.i. pigment blue 2, c.i. pigment blue 3, c.i. pigment blue 15:34, c.i. pigment blue 16, c.i. pigment blue 22, c.i. pigment blue 60, c.i. vat blue 4, c.i. vat blue 60, c.i. pigment blue 15:2, c.i. pigment blue 15:4, c.i. pigment green 3, c.i. pigment violet 23, and c.i. pigment violet 37.

Preferably, the organic pigment is selected from the group consisting of c.i. pigment red 176, c.i. pigment red 254, c.i. pigment red 255, c.i. pigment red 272, c.i. pigment red 254, c.i. pigment orange 64, c.i. pigment orange 73, c.i. pigment yellow 83, c.i. pigment yellow 138, c.i. pigment yellow 139, c.i. pigment yellow 151, c.i. pigment yellow 154, c.i. pigment blue 15:2, c.i. pigment blue 15:3, c.i. pigment blue 15:4, c.i. pigment green 3, c.i. pigment violet 23 and c.i. pigment violet 37.

Preferably, the colorant is present from 1 to 25 wt% based on the total weight of the ink composition, more preferably from 1.5 to 15 wt%, most preferably from 2 to 6 wt% based on the total weight of the ink composition.

Preferably, the colorant is present at less than 25 wt%, more preferably less than 15 wt%, even more preferably less than 4 wt%, based on the total weight of the ink composition. Preferably, the colorant is present at greater than 1 wt%, preferably greater than 1.5 wt%, even more preferably greater than 2 wt%, based on the total weight of the ink composition. The colorant may be present in an amount within a range selected from the upper and lower limits of the amounts recited above.

In this way, the formulation can have a desired opacity and color.

Metal crosslinking agent

The metal crosslinking agent contains a metal substance that can form crosslinks between polymers of the main binder resin. The metal species of the metal crosslinker may form crosslinks between the polymers of the carboxyl resin and/or the polymers of the third resin present. Any suitable metallic species may be used for this purpose.

Preferably, the metallic crosslinker is a titanium or zirconium containing material, preferably a ti (iv) or zr (iv) containing material. A metal crosslinker may be used that reacts in solution to form crosslinks between two or more polymers with the metal in the metal crosslinker.

The metal crosslinker may be a metal ligand complex, such as a metal cation with an organic ligand. Preferably, the ligand of the metal-ligand complex is an organic ligand, such as an alkyl carboxylate. Preferably, the metal of the metal-ligand complex is a metal cation, such as Ti (IV) or Zr (IV). For example, the metal crosslinker may be selected from titanium acetylacetonate, titanium butyl phosphate, titanium triethanolamine, titanium lactate, zirconium diethyl citrate, zirconium acetate, and zirconium propionate. Preferably, the metal crosslinker is zirconium propionate.

Preferably, the metal crosslinker is added in an amount of 0.1 to 5 wt%, more preferably 0.3 to 4 wt%, most preferably 0.7 to 3 wt%, based on the total weight of the ink composition.

Preferably, the metallic crosslinker is added in an amount of less than 5 wt%, more preferably less than 4 wt%, even more preferably less than 3 wt%, based on the total weight of the ink composition. Preferably, the metallic crosslinker is added in an amount of greater than 0.1 wt%, preferably greater than 0.3 wt%, even more preferably greater than 0.7 wt%, based on the total weight of the ink composition. The metal crosslinker may be present in an amount within a range selected from the upper and lower limits of the amounts described above.

Without wishing to be bound by theory, it is believed that the metal centers crosslink with certain polymers of the primary binder resin by the interaction of the coordinating groups on the polymer with the polymer. Examples of coordinating groups are hydroxyl, carboxyl and amino. In this way, the metallic crosslinker imparts high temperature resistance and offset resistance during cooking to the ink.

At least some crosslinking may occur in the liquid ink, however, it is preferred that complete crosslinking only occur upon evaporation of the solvent. Solvent evaporation increases the component concentration and will increase the rate of crosslinking. Complete crosslinking in the liquid ink can lead to gelation of the ink.

In some cases, at least some of the polymers of the primary binder resin are crosslinked in an organic solvent by a metal crosslinker.

Primary binder resin

The ink composition includes a primary binder resin. The primary binder resin comprises one or more polymers. One or more polymers of the primary binder resin may be crosslinked by a metal crosslinking agent. Crosslinking occurs through one or more suitable coordinating groups on the polymer of the primary binder resin.

The content of the coordinating group is 1.7 to 28 wt% based on the total weight of the main binder resin, more preferably, the content of the coordinating group is 2 to 22 wt%, even more preferably 3 to 17 wt%. Preferably, the content of the coordinating group is less than 28 wt%, more preferably less than 22 wt%, even more preferably less than 17 wt%, based on the total weight of the primary binder resin. Preferably, the content of the coordinating group is more than 1.7 wt%, preferably more than 2 wt%, even more preferably more than 3 wt%, based on the total weight of the main binder resin. The content of the coordinating group of the main binder resin may be within a range selected from the upper and lower limits of the above amount.

For example, the polymer of the main binder resin may have one or more of the following coordinating groups capable of binding the metal crosslinker; hydroxyl, carboxyl and amino.

As described above, the crosslinking of the main binder resin and the metal crosslinking agent imparts high temperature resistance and offset resistance during retort to the ink.

In addition, the main binder resin can impart desired viscosity and adhesion to the ink.

Without wishing to be bound by theory, it is proposed that the primary binder resin provides viscosity through chain entanglement, which causes the solution to resist flow. Adhesion can be achieved by several mechanisms: entanglement with the substrate upon drying, intermingling of polymer chains, and physical interactions such as hydrogen bonding and dipolar interactions between the polymer and the substrate.

In one embodiment, the polymer of the primary binder resin has hydroxyl groups coordinated with the metal crosslinker.

Preferably, the hydroxyl number is from 60 to 330mg KOH/g, more preferably from 100 to 265mg KOH/g, most preferably from 130 to 200mg KOH/g. Preferably, the hydroxyl number is less than 330mg KOH/g, more preferably less than 265mg KOH/g, and most preferably less than 200mg KOH/g. Preferably, the hydroxyl number is greater than 60mg KOH/g, more preferably greater than 100mg KOH/g, most preferably greater than 130mg KOH/g. The hydroxyl value of the primary binder resin may be within a range selected from the upper and lower limits of the above amounts.

The hydroxyl number is the number of milligrams of potassium hydroxide required to neutralize the acetic acid absorbed after acetylation of 1 gram of chemical containing free hydroxyl groups.

Preferably, the hydroxyl content is from 2 to 10 wt%, more preferably the hydroxyl content is from 3 to 8 wt%, even more preferably from 4 to 6 wt%, based on the total weight of the primary binder resin. Preferably, the hydroxyl content is less than 10 wt%, more preferably less than 8 wt%, even more preferably less than 6 wt%, based on the total weight of the primary binder resin. Preferably, the hydroxyl content is greater than 2 wt%, preferably greater than 3 wt%, even more preferably greater than 4 wt%, based on the total weight of the primary binder resin. The hydroxyl value of the primary binder resin may be within a range selected from the upper and lower limits of the above amounts. The hydroxyl group content of the main binder resin may be an amount within a range selected from the upper and lower limits of the above amount.

The hydroxyl content, expressed as a weight percentage, refers to the weight percentage (wt%) of hydroxyl groups per 100 grams of material in terms of the mass of hydroxide functional groups in grams.

In one embodiment, the polymer of the main binder resin has an amine group for coordinating with the metal crosslinker.

Preferably, the amine number is from 20 to 330mg KOH/g, more preferably from 30 to 265mg KOH/g, most preferably from 60 to 200mg KOH/g. Preferably, the amine number is less than 330mg KOH/g, more preferably less than 265mg KOH/g, most preferably less than 200mg KOH/g. Preferably, the amine number is greater than 20mg KOH/g, more preferably greater than 30mg KOH/g, and most preferably greater than 60mg KOH/g. The amine value of the main binder resin may be within a range selected from the upper and lower limits of the above amount.

The amine number is the number of milligrams of potassium hydroxide required to neutralize the acetic acid absorbed after acetylation of 1 gram of chemical containing free amine groups.

In one embodiment, the polymer of the main binder resin has a carboxyl group for coordinating with the metal crosslinking agent.

Preferably, the acid value of the primary binder resin is 60 to 500mg KOH/g, more preferably 100 to 500mg KOH/g, more preferably 130 to 500mg KOH/g, most preferably 200 to 500mg KOH/g. Preferably, the acid number is less than 500mg KOH/g, more preferably less than 450mg KOH/g, most preferably less than 400mg KOH/g. Preferably, the acid number is greater than 60mg KOH/g, more preferably greater than 100mg KOH/g, more preferably greater than 130mg KOH/g, and most preferably greater than 200mg KOH/g. The acid value of the main binder resin may be within a range selected from the upper and lower limits of the above amount.

The acid number is measured by titrating 1g of material with potassium hydroxide up to the point of neutralization. The acid number is the amount in milligrams (mg) of KOH required to achieve the point of neutralization.

The primary binder resin may be selected from any suitable binder resin, for example, suitable binders include polyamide resins, polyurethane resins, rosin ester resins, acrylic resins, polyvinyl butyral resins, polyesters, phenolic resins, vinyl resins, polystyrene/polyacrylate copolymers, cellulose ethers, cellulose nitrate resins, polymaleic anhydrides, acetal polymers, polystyrene/polybutadiene copolymers, polystyrene/polymethacrylate copolymers, sulfonated polyesters, aldehyde resins, polyhydroxystyrene resins, and polyketone resins, and mixtures of two or more thereof.

Preferably, the primary binder resin is selected from the group consisting of cellulose resins, acrylic resins, vinyl resins, polyamides, polyesters and polyurethanes. More preferably, the primary binder resin is a cellulose resin. Even more preferably, the cellulose resin is cellulose acetate butyrate.

Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the primary binder resin is from 1,500 to 50,000, more preferably from 10,000 to 50,000, even more preferably from 15,000 to 50,000. Preferably, the primary binder resin has a molecular weight, e.g., a weight average molecular weight (Mw), of at least 1,500, more preferably at least 10,000, even more preferably at least 15,000. Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the primary binder resin is less than 50,000. The molecular weight, e.g., the weight average molecular weight (Mw), of the primary binder resin is within a range selected from the upper and lower limits of the aforementioned amounts.

Preferably, the primary binder resin has good solubility in organic solvents commonly used in solvent-based inks. For example, the solubility of the main binder resin in a solvent at 25 ℃ is 20g/100mL to 100g/100 mL.

Preferably, the primary binder resin is present at 1.5 to 25 wt%, more preferably 2 to 10 wt%, even more preferably 4 to 6 wt%, based on the total weight of the ink composition.

Preferably, the primary binder resin is present at less than 25 wt%, more preferably less than 10 wt%, more preferably less than 8 wt%, even more preferably less than 6 wt%, based on the total weight of the ink composition. Preferably, the primary binder resin is present at greater than 1.5 wt%, preferably greater than 2 wt%, even more preferably greater than 4 wt%, based on the total weight of the ink composition. The primary binder resin may be present in an amount within a range selected from the upper and lower limits of the amounts described above.

Preferably, the primary binder resin is present in the composition in an amount greater than the amount of the carboxyl resin (if present) and greater than the amount of the third resin (if present).

Preferably, the primary binder resin has good solubility in organic solvents commonly used in solvent-based inks.

For example, the solubility of the main binder resin in a solvent at 25 ℃ is 20g/100mL to 100g/100 mL.

Combinations of different resins may provide the ink composition of the present invention, for example, a combination of the above resins, i.e., the primary binder resin, the starch resin, and the third resin.

In the printed deposit, at least some of the polymers of the primary binder resin are crosslinked by the metallic crosslinker.

Carboxyl resin

The ink composition may include a second resin that is different from the primary binder resin. The second resin is a carboxyl resin.

Carboxyl resins are resins having carboxyl functional groups, i.e. the resin contains one or more COOH residues. Examples of suitable carboxyl resins are acrylic resins, rosin resins and maleic resins. The carboxyl resin may be a polymer, for example a polymer having carboxyl functional groups, i.e. the polymer contains one or more COOH residues.

Without wishing to be bound by theory, it is believed that the carboxyl groups preferentially interact with the metal crosslinker, thereby hindering the viscosity increase through crosslinking of the primary binder resin. In this way, the carboxyl resin imparts improved storage stability to the ink.

Preferably, the carboxyl resin is a Styrene Maleic Anhydride (SMA) based polymer containing carboxyl functional groups.

SMA-based resins can be obtained, for example, by reacting polymerized styrene maleic anhydride with a suitable alcohol. This can be accomplished during the formulation of the ink composition by adding styrene maleic anhydride and a suitable alcohol to the ink formulation. Suitable alcohols include ethanol, isopropanol, n-propanol, isobutanol, n-butanol and 1-methoxy-2-propanol.

Preferably, the acid value of the carboxyl resin is from 60 to 500mg KOH/g, more preferably from 100 to 500mg KOH/g, more preferably from 130 to 500mg KOH/g, most preferably from 200 to 500mg KOH/g. Preferably, the acid number is less than 500mg KOH/g, more preferably less than 450mg KOH/g, most preferably less than 400mg KOH/g. Preferably, the acid number is greater than 60mg KOH/g, more preferably greater than 100mg KOH/g, more preferably greater than 130mg KOH/g, most preferably greater than 200mg KOH/g. The acid value of the carboxyl resin may be within a range selected from the upper and lower limits of the above amount.

The acid number is measured by titrating 1 gram of material with potassium hydroxide to a point of neutralization. The acid number is the amount in milligrams (mg) of KOH required to achieve the point of neutralization.

For example, in the case of a styrene maleic anhydride resin reacted with an alcohol, the alcohol reacted with the maleic anhydride group to form an ester group and a carboxyl group. This is sometimes referred to as the half ester (of maleic anhydride). In this case, the acid value of the alcohol-treated maleic anhydride is the number of milligrams of KOH required to neutralize one carboxyl group formed by reaction with the alcohol, i.e., one molecule of KOH per maleic anhydride group.

In addition, for example, styrene maleic anhydride has no carboxyl group. However, the styrene maleic anhydride group did react with KOH. The maleic anhydride group reacts with two molecules of KOH (i.e., they react as if they were two carboxyl groups) to form the potassium salt. The acid number specified for such resins is the number of milligrams of KOH required to neutralize 1 gram of resin according to the definition of 'acid number'. Thus, although there are no carboxyl groups, styrene maleic anhydride still has an 'acid value'. The acid number of the styrene maleic anhydride will be twice the acid number required to neutralize the corresponding alcohol-treated styrene maleic anhydride.

Preferably, the carboxyl resin is present at 0.1 to 10 wt%, more preferably 0.5 to 5 wt%, even more preferably 1 to 2 wt%, based on the total weight of the ink composition.

Preferably, the carboxyl resin is present at less than 10 wt%, more preferably less than 5 wt%, more preferably less than 3 wt%, even more preferably less than 2 wt%, based on the total weight of the ink composition. Preferably, the carboxyl resin is present at greater than 0.1 wt%, preferably greater than 0.5 wt%, even more preferably greater than 1 wt%, based on the total weight of the ink composition. The amount of carboxyl resin present may be within a range selected from the upper and lower limits of the amounts described above.

Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the polymer of the carboxyl resin is 1,500 to 50,000, more preferably 2,000 to 20,000, even more preferably 4,000 to 10,000. Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the polymer of the carboxyl resin is less than 50,000, more preferably less than 20,000, even more preferably less than 10,000. Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the polymer of the carboxyl resin is at least 1,500, more preferably at least 2,000, even more preferably at least 4,000. The molecular weight, e.g., the weight average molecular weight (Mw), of the polymer of the carboxyl resin is within a range selected from the upper and lower limits of the above amounts.

Preferably, the primary binder comprises a polymer having a molecular weight higher than that of the polymer of the carboxyl resin. The higher molecular weight polymer of the primary binder resin means that crosslinking of the primary binder resin increases the viscosity of the ink composition. The preferential crosslinking of the carboxyl groups makes it possible to control this increase in viscosity and thus to improve the storage stability of the ink composition without affecting the retort resistance.

Preferably, the carboxyl resin has good solubility in organic solvents commonly used in solvent-based inks. For example, the solubility of the carboxyl resin in the solvent at 25 ℃ is 20g/100mL to 100g/100 mL. Preferably, the solubility of the carboxyl resin is greater than 20g/100mL at 25 deg.C, more preferably, the solubility is greater than 50g/100mL at 25 deg.C. The solubility of the carboxyl resin in the solvent may be within a range selected from the upper and lower limits of the above amount.

A third resin

The ink composition may include a third resin. The third resin is different from the main binder resin and from the carboxyl resin present. The third binder resin increases the solubility of the ink to impart reliable printer operation.

The third binder resin may have, for example, a lower molecular weight than the carboxyl resin, and may have a lower molecular weight than the main binder resin. .

Preferably, the molecular weight, e.g., weight average molecular weight (Mw), of the third binder resin is from 100 to 1,000, more preferably from 200 to 800, even more preferably from 250 to 500. Preferably, the molecular weight, e.g. the weight average molecular weight (Mw), of the third binder resin is less than 1000, more preferably less than 800, even more preferably less than 500. Preferably, the molecular weight, e.g. weight average molecular weight (Mw), of the third binder resin is at least 100, more preferably at least 200, even more preferably at least 250. The molecular weight, for example, the weight average molecular weight (Mw), of the third binder resin is within a range selected from the upper and lower limits of the above amounts.

The low molecular weight third binder resin imparts solubility to the ink composition.

Without wishing to be bound by theory, it is proposed that if the low molecular weight third binder resin is not coordinated, the low molecular weight third binder resin disrupts the crosslinking of the main binder resin by being located between the polymer chains of the main binder resin. In this way, it is considered that the third binder resin reduces the viscosity of the ink composition, thereby improving the solubility. In contrast, if the low-molecular-weight third binder resin is used for coordination, the low-molecular-weight third binder resin may compete with the main binder resin and the copolymer resin to bind the metal crosslinking agent and reduce the viscosity of the ink composition, thereby improving solubility.

The third binder resin may include carboxyl functional groups. Preferably, the acid value of the third binder resin is from 60 to 500mg KOH/g, more preferably from 120 to 500mg KOH/g, most preferably from 250 to 500mg KOH/g. Preferably, the acid number is less than 500mg KOH/g, more preferably less than 450mg KOH/g, most preferably less than 400mg KOH/g. Preferably, the acid number is greater than 60mg KOH/g, more preferably greater than 120mg KOH/g, most preferably greater than 200mg KOH/g. The acid value of the third binder resin may be within a range selected from the upper limit and the lower limit of the above amount.

The acid number is measured by titrating 1g of this material with potassium hydroxide up to the point of neutralization. The acid number is the amount in milligrams (mg) of KOH required to achieve the point of neutralization.

The third binder resin may compete with the carboxyl resin to coordinate with the metal crosslinker.

Without wishing to be bound by theory, it is proposed that the crosslink density of the dried ink may decrease if the third binder resin competes with the carboxyl resin to coordinate with the metal crosslinker. The reduced crosslink density of the dried ink can affect the proposed retort resistance, which is provided by the main binder resin crosslinking. Preferably, a small amount of the third binder resin is used to balance the desired solubility while maintaining retort resistance.

Preferably, the third binder resin is present at 0.1 to 1 wt%, more preferably 0.3 to 0.9 wt%, even more preferably 0.5 to 0.8 wt%, based on the total weight of the ink composition.

Preferably, the third binder resin is present at less than 1 wt%, more preferably less than 0.9 wt%, even more preferably less than 0.8 wt%, based on the total weight of the ink composition. Preferably, the third binder resin is present at greater than 0.1 wt%, preferably greater than 0.3 wt%, even more preferably greater than 0.5 wt%, based on the total weight of the ink composition. The third resin may be present in an amount within a range selected from the upper and lower limits of the amounts described above.

The third binder resin may be a rosin resin. The rosin resin may be a hydrogenated rosin resin, a polymerized rosin resin, an ester of a rosin resin, a phenolic-modified rosin resin, or a maleic-modified rosin resin. Preferably, the rosin resin is a maleic acid modified rosin resin such as Erkamar 3360.

Preferably, the third resin has good solubility in organic solvents commonly used in solvent-based inks. For example, the solubility of the third resin in the solvent at 25 ℃ is 1g/100mL to 100g/100 mL.

Additive agent

The ink composition and printed deposit may comprise other components such as are common in the art.

Preferably, the ink composition and printed deposit may further comprise one or more preservatives, moisture absorbers, surfactants, conductive salts, humectants, adhesion promoting additives, biocides, and mixtures of two or more thereof.

Conductivity additives

Preferably, the ink composition and the printed deposit further comprise a conductivity additive. The conductivity additive may be any organic salt known in the art.

Conductivity additives for ink compositions are well known in the art, particularly conductivity additives for ink jet ink compositions.

Preferably, the organic salt is selected from quaternary ammonium salts or phosphonium salts. For example, the organic salt may be selected from tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium acetate, tetrabutylammonium nitrate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylphosphonium chloride, and tetrabutylphosphonium bromide. A preferred salt is tetrabutylammonium bromide.

Preferably, the conductivity additive is present at 0.1 to 5 wt% based on the total weight of the ink composition.

Moisture absorbent

Preferably, the ink composition and the printed deposit further comprise a moisture absorber.

Suitable moisture absorbents include ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 4-cyclohexanedimethanol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 8-octanediol, 1, 2-propanediol, 1, 2-butanediol, 1, 3-butanediol, 2, 3-butanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, glycerol, 1,2, 6-hexanetriol, sorbitol, 2-pyrrolidone, 2-propylene glycol, butyl propyl ester, tetrahydrofurfuryl alcohol, and 1,2, 4-butanetriol, and mixtures of two or more thereof. Preferably, the moisture absorbent is selected from the group consisting of glycerin, tetrahydrofurfuryl alcohol, polypropylene glycol, and mixtures of two or more thereof.

The ink composition may include a moisture absorber to solvent ratio of about 1: 1.

The ink composition may comprise up to 30 wt% of a moisture absorber, based on the total weight of the composition. More preferably, the ink composition comprises up to 20 wt% of moisture absorber, based on the total weight of the composition.

Preservative

Preferably, the ink composition and/or the printed deposit further comprises a preservative.

Suitable preservatives include sodium benzoate, benzoic acid, sorbic acid, potassium sorbate, calcium benzoate, methylparaben, and mixtures of two or more thereof. The preferred preservative is sodium benzoate.

The ink composition may comprise up to 2 wt% of a preservative, based on the total weight of the composition. More preferably, the ink composition comprises up to 1 wt% preservative, based on the total weight of the composition.

Surface active agent

Preferably, the inkjet ink composition and/or the printed deposit further comprises a surfactant.

Suitable surfactants include anionic, cationic or nonionic surfactants and mixtures of two or more thereof. Non-limiting examples of anionic surfactants include alkyl sulfates, alkylaryl sulfonates, dialkyl sulfosuccinates, alkyl phosphates, and polyoxyethylene alkyl ether sulfates. Non-limiting examples of cationic surfactants include alkylamine salts, ammonium salts, alkylpyridinium salts, and alkylimidazolium salts. Non-limiting examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, fluorine-containing nonionic surfactants, and silicon-containing nonionic surfactants. Mixtures of two or more surfactants may be used.

The ink composition may comprise up to 5 wt% of a surfactant, based on the total weight of the composition. More preferably, the ink composition comprises at most 1 wt% of surfactant, based on the total weight of the composition.

Type of package

The present application further provides a process for printing an image on a substrate comprising directing a stream of droplets of any embodiment of the ink composition of the present invention onto a substrate and allowing the droplets to dry, thereby printing an image on the substrate. Preferably, an ink jet printer, such as a continuous ink jet printer, is used in the method. Any suitable substrate may be printed according to the present invention.

The ink composition of the present invention is particularly suitable for printing on non-porous materials, such as non-porous materials used for food packaging.

Examples of suitable substrates include metal cans, plastic pots, retort pouches and flexible plastic films. These substrates can be made of, for example, aluminum, steel, LDPE, HDPE, polypropylene, PET, nylon or PVdC.

Method and use

The ink composition is formulated by combining the components using methods known in the art. The metal crosslinker additives described herein can be easily incorporated into existing formulation processes because the metal crosslinker additives are present in the ink composition in relatively low amounts. Thus, the metal crosslinker additive preferably does not create solubility issues that require modification of existing formulation processes. Instead, the metal crosslinker additive is added to the ink composition only with the other components of the ink composition. Since the metal crosslinker additive is easily incorporated into existing processes, it is cost effective to reduce nozzle plate wetting and/or increase throw distance and/or increase decap time and/or increase the retort resistance of the ink composition.

In some embodiments, the metal crosslinker is mixed with the carboxyl resin in a volatile organic solvent prior to addition of the primary binder resin. For example, the carboxyl resin and the metal crosslinking agent may be mixed for about 12 to 24 hours before the addition of the main binder resin.

In this way, the viscosity of the prepared ink is reliable. Without wishing to be bound by theory, it is proposed that the carboxyl resin is crosslinked with the metal crosslinker and reaches an equilibrium point prior to addition of the primary binder resin. This may result in reduced cross-linking of the primary binder resin and provide a more reliable viscosity.

The present application further provides a method of printing an image on a substrate in a continuous ink jet printer, the method comprising directing a stream of droplets of any embodiment of the ink composition onto a substrate and drying the droplets to print the image on the substrate. Any suitable substrate may be printed according to the present invention.

Examples of suitable substrates include porous substrates such as non-coated paper, semi-porous substrates such as water-coated paper, clay-coated paper, silica-coated paper, UV-coated paper, polymer-coated paper, and varnish-coated paper, and non-porous substrates such as hard plastics, polymer films, polymer laminates, metals, metal foil laminates, glass, and ceramics. The paper substrate may be a sheet of paper, a roll of paper, or a sheet of paperboard. The plastic, laminate, metal, glass and ceramic substrates may be in any suitable form, such as in the form of bottles or containers, plates, rods, cylinders, and the like.

Preferably, the ink compositions described herein are food grade ink compositions. The edible surface may be printed using the inks described herein. These foods include, but are not limited to, baked goods, cookies (bisuits) and cakes, cookies (cookies), nuts, chocolate, cheese, crackers and chips, pastries, puddings and mousses, ice cream and cream, pet foods and pet treats, main meal treats, cereals, sausage casings, and tablets.

The ink composition of the present invention is particularly useful for printing on egg shells. In the past, due to the curved shape of eggs, it has proven very difficult to provide high quality printing on eggshells, and thus the required throw distance is typically large compared to printing on flat surfaces. Other difficulties encountered when providing high quality printing on egg shells include the ability to provide ink compositions having good water resistance, adhesion, and contrast when printed onto egg shells.

Advantageously, at least some of the above-described problems are overcome and/or alleviated using the compositions and methods described herein, thereby providing improved quality printing.

Definition of

The term printed deposit as used herein refers to the ink composition after it has been printed onto a suitable substrate. This is the ink composition of the invention wherein at least some of the solvent has evaporated.

The term ink composition as used herein includes ink jet ink compositions suitable for ink jet printing. The ink composition is typically in liquid form and is typically a solution.

The terms cook, cooking or retorting as used in this application refer to further processing steps used in the food packaging industry, which steps are generally intended to extend the shelf life of the product. The retort process is a steam treatment process used to sterilize the package and partially cook the contents of the package.

The term offset as used herein refers to the process of transferring a code or the like printed on a packaging substrate to an adjacent substrate. Typically, this occurs during cooking and is often an undesirable result.

The term acid number as used herein refers to the number of milligrams of potassium hydroxide required to neutralize 1 gram of the acid of the oil.

The term C as used in this application_1-6Alkyl alcohol refers to any solvent having at least one hydroxyl functional group (-OH) and having 1 to 6 carbon atoms.

The term polymer as used herein refers to any substance having repeating units, including: polysaccharides and derivatives thereof, such as cellulose and derivatives thereof; addition polymers such as acrylic resins or polyethylene resins; condensation polymers such as polyurethanes, polyamides, and polyesters; and copolymers in which the repeat units are formed from two or more different compounds, such as styrene and maleic anhydride.

Other preferences

Each and every compatible combination of the above-described embodiments is expressly disclosed herein as if each and every combination was individually and explicitly recited.

Various further aspects and embodiments of the invention will be apparent to those skilled in the art in view of this application.

As used herein, "and/or" is considered to specifically disclose each of the two specified features or components as well as the two specified features or components. For example, "a and/or B" is considered to disclose specifically (i) a, (ii) B and (iii) a and B, respectively, as if they were individually listed in this application.

Unless the context indicates otherwise, the description and definition of features set forth above is not limited to any particular aspect or embodiment of the invention, and applies equally to all aspects and embodiments described.

Certain aspects and embodiments of the present invention will now be described by way of example and with reference to the above-described drawings.