Ink composition for continuous deflected jet printing

Abstract

An ink composition for continuous deflected ink jet printing, liquid at ambient temperature is disclosed. One aspect is an ink composition comprising: a solvent including organic solvent compound(s), and optionally water, the solvent representing at least 20% by weight of the total weight of the ink. Furthermore, there is at least one compound imparting conductivity to the ink composition, chosen from among the ionic liquids, the compound representing 0.2% by weight to 4% by weight of the total weight of the ink composition, preferably 0.5 to 3% by weight of the total weight of the ink composition. Lastly, the ink composition includes less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, and most preferably 0% by weight of water relative to the total weight of the ink composition.

Claims

1. A process for marking substrates, supports or objects by spraying an ink onto the substrates, supports or objects by a continuous deflected ink jet technique, wherein the ink is an ink composition for continuous deflected ink jet printing, comprising: a solvent consisting of one or more organic solvent compound(s), the solvent representing 30% to 90% by weight of the total weight of the ink; a dye that is soluble in the solvent; and at least one compound imparting conductivity to the ink composition, wherein the at least one compound is an ionic liquid composed of an organic cation imparting a positive charge thereto, with which an inorganic anion is associated imparting a negative charge thereto, wherein the at least one compound represents 0.2% by weight to 4% by weight of the total weight of the ink composition, and wherein the ionic liquid is a liquid at a temperature of 100° C. or lower; wherein the ink composition does not contain water, wherein the ink composition does not comprise a pigment, and wherein the ink composition is a liquid at ambient temperature.

2. The process according to claim 1, the ink composition further comprising a binder.

3. The process according to claim 2, wherein the binder comprises one or more resins or polymers.

4. The process according to claim 3, wherein the resin(s) and/or polymer(s) are selected from the group consisting of (meth)acrylic, vinyl, ketone, hydroxyaromatic, cellulosic, styrenic, epoxy, polyurethanes, styrene acrylates, alkoxysilanes, and the combinations thereof.

5. The process according to claim 4, wherein the hydroxyaromatic resins are selected from the group consisting of hydroxyphenol resins, phenol resins and polymers of hydroxy styrene.

6. The process according to claim 2, the ink composition comprising 0.1% to 30% by weight of the total weight of the ink composition of binder.

7. The process according to claim 1, wherein the ionic liquid is soluble in water to a proportion of not more than 0.1% by weight at ambient temperature.

8. The process according to claim 1, wherein the ionic liquids are selected from the group consisting of non-symmetrical alkyl-imidazolium salts, non-symmetrical alkylpyridinium salts, non-symmetrical aryl-pyridinium salts, non-symmetrical alkyl-phosphonium salts, substituted pyrrolidinium salts, non-symmetrical tetra-alkyl ammonium salts, guanidinium salts, and mixtures thereof.

9. The process according to claim 1, wherein the ionic liquids are selected from the group consisting of triflates, tetrafluoroborates, hexafluorophosphates, tosylates, thiocyanates, bistriflimides, trifluoromethanesulfonylimides, formiates, halides, alkylsulfates, alkylphosphates, alkylsulfonates, methylcarbonates, glycolates, dicyanamides, acetates of non-symmetrical alkyl-imidazolium, acetates of non-symmetrical alkylpyridinium, acetates of nonsymmetrical aryl-pyridinium, acetates of non-symmetrical alkyl-phosphonium, substituted pyrrolidiniums, substituted non-symmetrical tetra-alkyl ammoniums, guanidinium, and mixtures thereof.

10. The process according to claim 1, wherein the organic solvent compound(s) comprise a majority proportion by weight of one or more volatile organic solvent compound(s).

11. The process according to claim 10, wherein the organic solvent compound(s) are selected from the group consisting of alcohols, ketones, ethers of alkylene glycols, esters of alkylene glycols, esters of ethers of alkylene glycols, dimethyl formamide, N methylpyrrolidone, straight-chain or cyclic ethers, acetals, esters, cyclic or straight-chain aliphatic hydrocarbons, aromatic hydrocarbons, carbonates, and mixtures thereof.

12. The process according to claim 10, wherein the organic solvent(s) are selected from the group consisting of straight-chain aliphatic alcohols with 1 to 8 carbon atoms, branched aliphatic alcohols with 1 to 8 carbon atoms, ketones with 3 to 10 carbon atoms; mono alkyl ethers with a Cl-6 alkyl group, dialkyl ethers with a Cl-6 alkyl group, alkylene glycols with 1 to 10 carbon atoms in the alkylene chain, esters of alkylene glycols, esters of ethers of alkylene glycols with saturated aliphatic, and carboxylic acids with 1 to 6 carbon atoms.

13. The process according to claim 1, the ink composition further comprising one or more plasticizer(s) to the proportion of at least 0.05% by weight of the total weight of the ink composition.

14. The process according to claim 1, wherein the dye is selected from the group consisting of C.I. solvent dyes.

15. The process according to claim 14, wherein the dye is selected from the group consisting of C. I. Solvent Black 29, C. I. Solvent Black 7, C. I. Solvent Black 28, C. I. Solvent Black 27, C. I. Solvent Black 35, C. I. Solvent Black 45, C. I. Solvent Blue 70, and C. I. Solvent Red 124.

16. The process according to claim 1, comprising 0.05% to 25% by weight of dye of the total weight of the ink composition.

17. The process according to claim 1, wherein the conductivity of the ink composition is equal to or more than 5 μS/cm at 20° C.

18. The process according to claim 1, the ink composition further comprising one or more additives selected from the group consisting of anti-foaming agents, chemical stabilizers, UV stabilizers, surfactants, agents inhibiting corrosion by salts, bactericides, fungicides, biocides, and pH control buffers.

19. The process according to claim 1, wherein the at least one compound is about 0.5 to 3% by weight of the total weight of the ink composition.

20. An ink composition for marking substrates, supports or objects by spraying an ink onto the substrates, supports or objects by the continuous deflected ink jet technique, liquid at ambient temperature, wherein the ink of the sprayed ink is an ink composition comprising: a solvent consisting of one or more organic solvent compound(s), the solvent representing 30% to 90% by weight of the total weight of the ink; a dye that is soluble in the solvent; and at least one compound imparting conductivity to the ink composition, wherein the at least one compound is an ionic liquid composed of an organic cation imparting a positive charge thereto, with which an inorganic anion is associated imparting a negative charge thereto, wherein the at least one compound represents 0.2% by weight to 4% by weight of the total weight of the ink composition, and wherein the ionic liquid is a liquid at a temperature of 100° C. or lower; wherein the ink composition does not contain water, and wherein the ink composition does not comprise a pigment.

21. A substrate, support or object provided with a marking obtained by drying and/or absorption of an ink composition for continuous deflected ink jet printing, liquid at ambient temperature, the ink composition comprising: a solvent consisting of one or more organic solvent compound(s), the solvent representing 30% to 90% by weight of the total weight of the ink; a dye that is soluble in the solvent; and at least one compound imparting conductivity to the ink composition, wherein the at least one compound is an ionic liquid composed of an organic cation imparting a positive charge thereto, with which an inorganic anion is associated imparting a negative charge thereto, wherein the at least one compound represents 0.2% by weight to 4% by weight of the total weight of the ink composition, and wherein the ionic liquid is a liquid at a temperature of 100° C. or lower; wherein the ink composition does not contain water, and wherein the ink composition does not comprise a pigment.

22. The substrate according to claim 21, wherein the substrate is made of a material selected from a group consisting of metal, glass, ceramic, a cellulose-containing material, a synthetic polymer, polymethylmethacrylate, fabric, and combinations thereof.

Description

EXAMPLES

(1) The following ink compositions according to the invention were prepared by mixing the products given in Table I below in the indicated proportions. The viscosities and conductivities of the inks obtained are also given below.

(2) The viscosities were measured using a Low-Shear coaxial cylinder viscometer by Contraves (Switzerland) at 20° C., and conductivities were measured at ambient temperature, generally 20° C.

(3) TABLE-US-00001 TABLE I Examples Comparative Comparative (weight percentages) Example 1 Example 2 N.sup.o1 N.sup.o2 N.sup.o3 N.sup.o4 Methyl ethyl ketone 64.25 72.4 64.25 69.49 70.56 70.56 LTH resin by HULS 2.0 2.0 Resamine HF480 13.7 13.7 Solvent Black 29 6.15 5 6.15 4.37 4.91 4.91 Acrylic resin (Joncryl 690 by 8.8 8.8 BASF) Aminopropyltrimethoxysilane 2 1.75 1.96 1.96 Phenolic resin of novolac type 20 22.99 19.63 19.63 Polyester resin (Reactol 545 by 4.4 4.4 Hexion) Potassium hexafluorophosphate 0.6 0.5 1-butyl-3-methylimidazolium 0.6 1.31 2.94 hexafluorophosphate 1-butyl-3-methylimidazolium 2.94 tetrafluoroborate Tegoglide 435 0.1 0.1 Byk UV 3500 0.1 Tegophobe 6000 0.09 Viscosity (mPa .Math. s) 5.16 4.56 5.18 4.58 5.45 5.83 Conductivity (μS/cm) 705 780 613 716 883 1218

(4) The ink compositions of the invention prepared according to Examples 1 to 4, and also those of comparative Examples 1 and 2, were filtered on filters having a porosity of 1 μm, and gave inks that can be sprayed by ink-jet.

(5) The inks thus prepared were tested on Markem-Imaje® printers of type 9040 which operate according to the principle of continuous deflected ink jet printing.

(6) The markings, printings obtained with the inks of Examples 1 to 4 and comparative Examples 1 and 2 were all of excellent quality and their resistance to rubbing with water on glass was excellent.

(7) However, the resistance of the printing obtained with the ink composition according to the invention of Example 1 was better than the resistance of the printing obtained with the ink of comparative Example 1 which does not contain an ionic liquid.

(8) Also, and contrary to the indication given in document WO-A-2010/103088, the water resistance of the printing obtained with the ink compositions of the invention of Examples 2 and 3 containing an ionic liquid is obtained without heating the complete solution, whereas with the ink of comparative Example 2 it is necessary for the formulation to be heated so that the printing obtained are resistant to rubbing with water on glass.