CA2351162A1 - Printed media coating - Google Patents

9 heterocyclic (meth)acrylates (for example morpholinoethyl (meth)acrylate, N(2-methacryloyloxyethyl)ethyleneurea) or hydroxy esters (for example 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate) or alkyl polyethylene glycol (200-2000) (meth)acrylates (for example methoxypolyethylene glycol 750 methacrylate), can be used. Water-soluble polymers based on (meth)acrylic acid, which have dispersing or pigment-stabilizing properties and moreover, by interaction with the carbon black pigment, should prevent diffusion into the paper surface, can be used as the polyampholytes. Graft polymers with emulsifier properties, which are obtained by copolymerization of hydrophobic macromonomers with functionalized end groups with hydrophilic monomers (EP
0 728 780 B1), can be used as the comb polymers. The macromonomers with a (meth)acryloyl end group are prepared, for example, from C8_C3oalkyl methacrylates, cyclohexyl methacrylate or benzyl methacrylate and then with hydrophilic (meth)acrylates (for example (meth)acrylic acid, (meth)acrylamide, 2-hydroxyethyl (meth)-acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate and dimethylaminopropyl(meth)acrylamide and quaternary ammonium compounds thereof).
Block copolymers with the same monomer composition can equally suitably be used.
Copolymers which are prepared from acrylamide monomers and at least one of the monomers chosen from acrylic acid, dimethylaminopropylamine, dimethylaminopropylacrylamide (basic, neutral, quaternized), dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate, can be used as the polymers.

(d) The ink can comprise a polymer with functional groups and the media coating can comprise a compound which contains hydroxyl groups and is optionally modified with silane. The functional groups of the polymer can react 5 with the functional groups of the compound containing hydroxyl groups or silane-modified compound containing hydroxyl groups.
Precipitated silicas, pyrogenic silicas, pyrogenic oxides, silica sols, silica gels or naturally occurring

14 The functional groups can react with the crosslinking agent. The crosslinking agent can be activated by air, heat, light or UV.
(g) The ink and the media coating can comprise one or more monomers and the ink and/or media coating can comprise a polymerization initiator. The ink and the media coating can be bonded by the polymers prepared by the polymerization.
The polymerization initiator can be activated by air, heat, light or W. In a particular embodiment of the invention, the polymerization can be carried out by autocatalysis, without a polymerization initiator.
Dimers, trimers or tetramers can be used as the monomers.
The ink can also comprise further constituents, such as, for example, water, solvents, polymer, cationic additives, binders, such as, for example, starch, cellulose, gelatine, casein, polyvinyl alcohol, polyvinylpyrrolidone, styrene/butadiene copolymer or ethylene/vinyl acetate copolymer, glass frit and other auxiliary substances.
The media coating can also comprise further constituents, such as, for example, binders, pigment, wetting agents, tinting dyestuffs, antistatics and other auxiliary substances.
The ink jet process, for example, can be used as the process for the production of the printed media coating.
The printing can be carried out at temperatures of 10 ~C to 200 ~C. A heat treatment, for example by a heated roller, at 10~C to 300qC can optionally take place after the printing, in order to allow the reaction or to bring it to completion.

The printed media coatings can be used for the production of books, journals, posters, newspapers, textiles, articles of glass, metal or ceramic, depending on the medium.
The printed media coatings according to the invention have 5 a higher water resistance, fastness to light, fastness to wiping and an improved print quality. The printing can be carried out at a higher printing speed.

Examples To evaluate the interactions between inks and coating materials, coloristic measurements are carried out and the improved fastness to wiping is evaluated.
For the inks described by way of example which are based on pigment carbon blacks, the optical density D is determined with a densitometer from Macbeth of the type RD 918.
The fastness to wiping of an ink - coating material combination is estimated by the following method.
A modified K Control Coater from Erichson is used for the newly developed test method. An ink according to the invention described by way of example is knife-coated on to the medium to be coated (paper, film etc.) and dried, wetted with a defined amount of water and the water is wiped over the area to be tested by operating the slide.
The optical densities before and after wiping are determined as measurement values and a standardized rating of the pigment discharge is given with a figure from 0 (complete discharge) - 9 (no discharge). The data of the media coatings selected are assigned to the corresponding example.
Example 1 Preparation of a carbon black dispersion Distilled water is initially introduced into a dispersing vessel and 7.5 ~ Lutensol AO 30 from BASF is slowly added with the Ultra-Turrax running. When the Lutensol has dissolved completely, 2.1~ Hypomer CG6 from ICI Surfactants and 0.3~ AMP 90 from Angus Chemie are added. 15~ carbon black FW18 from Degussa are then added in portions, the dispersion is dispersed with the Ultraturrax (level 10) and thereafter the coarse contents are separated off in a centrifuge.
A bead mill is employed for further homogenization of the dispersion. The amount flowing through is 31/h at 3000 rpm.
To separate off bead fragments, the mixture is filtered over a sieve of 100).tm mesh width and centrifuged at 4000 rpm.
Preparation of an ink g 2-pyrrolidone, 5 g 1,2-propanediol and 4 g 1,5-10 pentanediol are topped up with 65 ml water. 35 g of the dispersion described above are then added, while stirring.
The ink obtained in this manner is then deaerated and introduced into the cartridge.
Production of the media coating 0.8 g NaN02 are added to 50 g ink, while stirring. The ink is investigated in respect of its fastness to wiping and optical density by the test methods mentioned.
A paper which is modified with amino-functional groups by the following process is used as the medium to be coated.
To prepare the brushing paints for the paper, polyvinyl alcohol (PVA) is dissolved in the total amount of water at approx. 95QC, the pigment (precipitated silica + Dynasilan~
AMEO from Sivento) is then incorporated at 500 to 1000 rpm and the components are dispersed for half an hour at 3000 rpm. The brushing paints are adjusted to a solids content of 18 ~. The example recipe comprises 100 parts of pigment and 50 parts of Mowiol 28-99 (PVA from Clariant GmbH). The solids content is 18~, the application weight is approx. 10 g/m2. The viscosity is determined by the Brookfield method, after stirring up. Thereafter, all the brushing paints are used to knife-coat in each case 10 sheets by hand on an 80 g/m2 wood-free base paper, and the coated papers produced are calendered, weighed and then subjected to the individual tests. The tests for determination of the quality of the paper include a printing test (printing a test image on an EPSON Stylus color 800 and HP Deskjet 550) and a drying test (determination of the drying time of 1 ~,1 water on the paper coated with ink).
The optical density of the ink coating according to the invention described above is 1.11. The difference from the optical density after the wiping operation is 0.05. The pigment discharge is rated as 8.
Example 2 Functionalization of a pigment carbon black g of a carbon black doped with silicon (according to EP

15 0799866) are stirred into 100 ml methyl ethyl ketone, 1.5 g Dynasylan~ Glymo from Sivento are added, and the mixture is stirred for 12 hours at room temperature and then filtered with suction. The carbon black obtained is then dried in a drying cabinet at 100 ~C for eight hours.
The functionalized carbon black is incorporated into a dispersion by the process described in example 1 and this is converted into an ink. The ink is investigated in respect of its fastness to wiping and optical density by the test method mentioned.
A paper which is coated by the process described in example 1 is used as the medium to be coated.
The optical density of the corresponding coating is 1.23.
The difference from the optical density after the wiping operation is 0.11. The pigment discharge is rated as 7.

Example 3 Functionalization of a pigment carbon black 15 g of a carbon black doped with silicon (according to EP
0799866) are stirred into 100 ml methyl ethyl ketone, 1.5 g Dynasylan~ 1161 (based on the active compound) from Sivento are added, and the mixture is stirred for 12 hours at room temperature and then filtered with suction. The carbon black obtained is then dried in a drying cabinet at 100 ~C
for eight hours.
The functionalized carbon black is incorporated into a dispersion by the process described in example 1 and this is converted into an ink. The ink is investigated in respect of its fastness to wiping and optical density by the test method mentioned.
A paper which is coated by the process described in example 1 is used as the medium to be coated. In addition to the constituents described, Polystabil 5312 from Stockhausen was added.
The optical density of the corresponding coating is 1.20.
The difference from the optical density after the wiping operation is 0.04. The pigment discharge is rated as 9.
Example 4 Preparation of a carbon black dispersion The dispersion is prepared analogously to example 1. Tego ABIL soft AF 100 from TEGO is used as the polymeric wetting agent.
The dispersion is converted into an ink as described in example 1.
A paper which is coated by the process described in example 1 is used as the medium to be coated. Instead of Dynasilan~

AMEO, Dynasilan~ Glymo is incorporated into the paper coating.
The optical density of the corresponding coating is 1.25.
The difference from the optical density after the wiping 5 operation is 0.03. The pigment discharge is rated as 9.
Example 5 Functionalization of a pigment carbon black Variant 1:
A solution of 2 ml azidosilane Si250 from Degussa in 150 ml 10 acetone is added to 10 g carbon black FW1 from Degussa, the mixture is stirred for 30 minutes at RT and the solvent is then stripped off in vacuo. The carbon black is heat-treated for two hours at 180~C. It is then washed with acetone and dried in a drying cabinet at 105~C for eight 15 hours.
Variant 2 A solution of 2 ml azidosilane Si250 from Degussa in 150 ml acetone is added to 10 g FW1 from Degussa and the solution is stirred for six hours under irradiation from two 20 laboratory heating lamps and while cooling with water (temp<50~C). It is then filtered with suction and the residue is dried in a drying cabinet at 105$C for eight hours.
The functionalized carbon blacks are incorporated into dispersions by the process described in example 1 and these are converted into inks. The ink is investigated in respect of its fastness to wiping and optical density by the test method mentioned.
Copy office paper from Kompass is used as the medium to be coated.

The optical density of the corresponding coating is 1.45 (variant 1) or 1.42 (variant 2). The difference from the optical density after the wiping operation is 0.02 (variant 1) or 0.04 (variant 2). The pigment discharge is rated as 9 (variant 1) or 8 (variant 2).
Example 6 Functionalization of a pigment carbon black 2 g Si69 (bis(triethoxysilylpropyl)tetrasulfane) from Degussa are dissolved in 150 ml toluene, 10 g FW1 are added and the mixture is boiled under reflux for five hours. The carbon black is then filtered off with suction and dried in a drying cabinet at 105~C for eight hours. The yield is determined with the aid of the amount of carbon black obtained.
Yield: 75~
The functionalized carbon black is incorporated into a dispersion by the process described in example 1 and this is converted into an ink. The ink is investigated in respect of its fastness to wiping and optical density by the test method mentioned.
Copy office paper from Kompass was used as the medium to be coated.
The optical density of the corresponding coating is 1.42.
The difference from the optical density after the wiping operation is 0.04. The pigment discharge is rated as 9.
The inks described are investigated for their printability.
Printing tests are carried out by means of commercially obtainable office inkjet printers. Printing takes place on in each case one side on four different commercially available ink jet papers and on copying paper immediately and after a 5 min, 10 min, 20 min, 30 min and 60 min printing pause. A long-term test (printing of 20 pages without a pause) and a refire test (investigation of the writing properties of the ink after a 1, 3 and 7 day printing pause) is furthermore carried out. The printed images correspond to or exceed the results of the corresponding original inks.

1. A printed media coating, wherein at least one constituent of the ink is bonded to at least one constituent of the media coating via a chemical bond.

2. A printed media coating as claimed in claim 1, wherein the media are glass, ceramic, plastic, textiles, leather or paper.

3. A printed media coating as claimed in claim l, wherein the ink comprises nitrite and carbon black and/or dyestuff and the media coating comprises a compound containing amino groups.

4. A printed media coating as claimed in claim 1, wherein the ink comprises a doped carbon black or dyestuff and the media coating comprises a compound containing hydroxyl groups, the doped carbon black or dyestuff and/or the compound containing hydroxyl groups being modified with a silane.

5. A printed media coating as claimed in claim 1, wherein the ink comprises a doped carbon black or dyestuff, optionally modified with a silane, and the media coating comprises a polymer with functional groups.

6. A printed media coating as claimed in claim 1, wherein the ink comprises a polymer with functional groups and the media coating comprises a compound which contains hydroxyl groups and is optionally modified with silane.

7. A printed media coating as claimed in claim 1, wherein the ink comprises a carbon black with -SiR(3-a) (O-(CH3)n-CH3)a groups (n = 0 - 5, a = 1 - 3, R = alkyl) and the media coating comprises a compound containing hydroxyl groups.

8. A printed media coating as claimed in claim 1, wherein the ink comprises an oligomer or polymer and a crosslinking agent and the media coating comprises an oligomer or polymer, optionally a crosslinking agent.

9. A printed media coating as claimed in claim 1, wherein the ink and the media coating comprise one or more monomers and the ink and/or media coating comprise a polymerization initiator.

l0.An ink, wherein at least one constituent of the ink forms a chemical bond with at least one constituent of the media coating.

11.A media coating, wherein at least one constituent of the media coating forms a chemical bond with at least one constituent of the ink.

12. A process for the production of a printed media coating as claimed in claim 1, which comprises spraying, printing or atomizing the ink on to the media coating and reacting at least one constituent of the ink with at least one constituent of the media coating to form a chemical bond.

13.A process for the production of a printed media coating as claimed in claim 12, wherein an ink jet process is used.

14.A process for the production of a printed media coating as claimed in claim 12, wherein the printing is carried out at temperatures of 10°C to 200°C.

15.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises nitrite and carbon black and/or dyestuff and the media coating comprises a compound containing amino groups.

16.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises a doped carbon black or dyestuff and the media coating comprises a compound containing hydroxyl groups, the doped carbon black or dyestuff and/or the compound containing hydroxyl groups being modified with a silane.

17.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises a doped carbon black or dyestuff, optionally modified with a silane, and the media coating comprises a polymer with functional groups.

18.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises a polymer with functional groups and the media coating comprises a compound which contains hydroxyl groups and is optionally modified with silane.

19.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises a carbon black with -SiR(3-a) (O-(CH2)n-CH3)a groups (n = 0-5 , a = 1-3, R = alkyl) and the media coating comprises a compound containing hydroxyl groups.

20.A process for the production of a printed media coating as claimed in claim 12, wherein the ink comprises an oligomer or polymer and a crosslinking agent and the media coating comprises an oligomer or polymer, optionally a crosslinking agent.

21.A process for the production of a printed media coating as claimed in claim 12, wherein the ink and the media coating comprise one or more monomers and the ink and/or media coating comprise a polymerization initiator.

22.The use of a printed media coating as claimed in claim 1 for the production of books, journals, posters, newspapers, textiles, articles of glass, metal or ceramic.