CERAMIC INK FOR INKJET DIGITAL PRINTING

Abstract

Ceramic ink for digital printing comprising a solid part provided with at least one ceramic component and a liquid part provided with at least one first vehicle, wherein said first vehicle is selected from the group comprising: esterified terephthalates, cyclohexane dicarboxylates, citrates, trimethylolpropane esters, fatty acid esters of aromatic alcohols.

Claims

1.-10. (canceled)

11. A ceramic ink for digital printing comprising a solid part provided with at least one ceramic component and a liquid part provided with at least one first vehicle, wherein said first vehicle is selected from the group comprising: esterified terephthalates, cyclohexane dicarboxylates, citrates, trimethylolpropane esters, fatty acid esters of aromatic alcohols.

12. An ink according to claim 11, in which the first vehicle represents at least 10 wt % relative to the total weight of the ink.

13. The ink according to claim 11, in which the esterified terephthalates have the general formula: ##STR00010## in which the cyclohexane dicarboxylates have the general formula: ##STR00011## in which the citrates have the general formula: ##STR00012## in which the trimethylolpropane esters have the general formula: ##STR00013## in which the fatty acid esters of aromatic alcohols have the general formula: ##STR00014## and in which R, R′, R″, R′″, R1 and R2 comprise a linear or branched aliphatic group.

14. The ink according to claim 11, in which said first vehicle has a boiling point above 250° C.

15. The ink according to claim 11, comprising a second vehicle selected from the group comprising: glycol ethers, alcohols, lactates, glycol ether acetates, aldehydes, ketones, linear and/or cyclic aliphatic hydrocarbons, aromatic hydrocarbons, oils, alkyl carbonates, fatty acid esters, polyacrylates, polymethacrylates and/or block copolymers.

16. The ink according to claim 15, in which the content of the second vehicle is less than 30 wt % relative to the total weight of the ink.

17. The ink according to claim 11, comprising at least one additive, in which said additive may at least be selected from the group comprising: dispersants, surfactants, viscosity modifiers, suspending agents, wetting agents, antifoaming agents, moistening agents, biocides, adhesion promoters, glue and colorants.

18. The ink according to claim 17, in which the content of additive is less than 5 wt % relative to the total weight of the ink.

19. A ceramic ink for digital printing comprising a solid part provided with at least one ceramic component and a liquid part provided with at least one first vehicle, in which said first vehicle has a boiling point above 250° C.

20. The ceramic ink for digital printing comprises a solid part provided with at least one ceramic component and a liquid part provided with at least one first vehicle, in which said first vehicle has a molecular weight above 190 g/mol.

Description

EXAMPLE 1

[0058] In the first embodiment example, the ink comprises the formulation given in Table 2.

TABLE-US-00002 TABLE 2 Component Percentage by weight (%) Solid part 42 First vehicle 32.1 Second vehicle 22.5 Additive 3.4

[0059] The solid part comprises particles having a maximum dimension equal to 1.2 μm with the following granulometric distribution: Dv (10) of 0.24 μm, a value of Dv (50) of 0.36 μm, a value of Dv (90) of 0.53 μm, a value of Dv (97) of 0.60 μm. The granulometry was measured with a laser diffraction granulometer (Mastersizer 3000, Malvern Panalytical).

[0060] The first vehicle comprises acetyl tributyl citrate (ATBC) having the following formula:

##STR00006##

[0061] The first vehicle selected in the first example comprises a boiling point of 331° C. Moreover, the first vehicle selected in the first example comprises a molecular weight of 402.48 g/mol and a viscosity of 15.9 cSt at 40° C.

[0062] The second vehicle selected in the first example is dipropylene glycol n-butyl ether (DOW Dowanol DPnB). This vehicle comprises a boiling point equal to 230° C., molecular weight equal to 190° C. and viscosity at 40° C. equal to 3.4 cSt.

[0063] The additive used in the first example is a polyamide dispersant produced by LUBRIZOL LTD and known by the trade name SOLSPERSE J980.

[0064] The ink thus obtained has a viscosity of 13.9 cSt at 40° C. (measured with a rheometer of the Kinexus type from Malvern Panalytical), a surface tension of 27.5 mN/m (measured by capillary tensiometer) and a density of 1359 g/l.

[0065] Table 3 shows the results of measurements of the concentration of emissions for example 0 and for example 1, as well as the percentage change between the measured results.

TABLE-US-00003 TABLE 3 Change relative to Parameter Sample 0 Example 1 Sample 0 (%) VOCs [mg/Nm.sup.3] 22.5 18.2 −19.1 Non-methane VOCs [mg/Nm.sup.3] 20.7 16.2 −21.7 Formaldehyde [mg/Nm.sup.3] 1.6 1.2 −25 Total aldehydes [mg/Nm.sup.3] 4.4 3.2 −27.3 Hydrofluoric acid [mg/Nm.sup.3] 0.6 0.6 0 Odoriferous substances [ouE/m.sup.3] 1165 598 −48.7

EXAMPLE 2

[0066] In the second embodiment example, the ink comprises the formulation given in Table 4.

TABLE-US-00004 TABLE 4 Component Percentage by weight (%) Solid part 42 First vehicle 40 Second vehicle 15 Additive 3

[0067] The solid part comprises particles having a maximum dimension equal to 1.2 μm with the following granulometric distribution: Dv (10) of 0.24 μm, a value of Dv (50) of 0.37 μm, a value of Dv (90) of 0.54 μm, a value of Dv (97) of 0.62 μm. The granulometry was measured with a laser diffraction granulometer (Mastersizer 3000, Malvern Panalytical).

[0068] The first vehicle selected in the second example comprises dipentyl terephthalate (DPT) having the following formula:

##STR00007##

[0069] The first vehicle selected in the second example comprises a boiling point of 353° C. Moreover, the first vehicle selected in the second example comprises a molecular weight of 306.4 g/mol and a viscosity of 13.1 cSt at 40° C.

[0070] The second vehicle selected in the second example is dipropylene glycol n-butyl ether (DOW Dowanol DPnB). This vehicle comprises a boiling point equal to 230° C., molecular weight equal to 190° C. and viscosity at 40° C. equal to 3.4 cSt.

[0071] The additive used in the second example is a polyamide dispersant produced by LUBRIZOL LTD and known by the trade name SOLSPERSE J980.

[0072] The ink thus obtained has a viscosity of 16.4 cSt at 40° C. (measured with a rheometer of the Kinexus type from Malvern Panalytical), a surface tension of 29.2 mN/m (measured by capillary tensiometer) and a density of 1367 g/l.

[0073] Table 5 shows the results of measurements of the concentration of emissions for example 0 and for example 2, as well as the percentage change between the measured results.

TABLE-US-00005 TABLE 5 Change relative to Parameter Sample 0 Sample 2 sample 0 (%) VOCs [mg/Nm.sup.3] 22.5 19.3 −14.2 Non-methane VOCs [mg/Nm.sup.3] 20.7 17.6 −15.0 Formaldehyde [mg/Nm.sup.3] 1.6 0.9 −43.8 Total aldehydes [mg/Nm.sup.3] 4.4 2.9 −34.1 Hydrofluoric acid [mg/Nm.sup.3] 0.6 0.5 −16.7 Odoriferous substances [ouE/m.sup.3] 1165 408 −65.0

[0074] As can be seen from the results given in Table 3 and in Table 5, the use of inks according to preferred embodiments of the ink makes it possible to lower the emissions of odoriferous substances by more than 40% relative to the conventional inks. Moreover, the inks according to the invention make it possible to lower the emissions of VOCs by at least 15% relative to the conventional inks, while the reduction in emissions of aldehydes and formaldehyde is greater than 25%.

[0075] Numerous modifications and variants of the invention thus conceived are possible, all within the scope of the inventive concept.

EXAMPLE 3

[0076] In the third example, the ink comprises the formulation given in Table 6.

TABLE-US-00006 TABLE 6 Component Percentage by weight (%) Solid part 45 First vehicle 51.4 Additive 3.6

[0077] The solid part comprises particles having a maximum dimension equal to 1.2 μm with the following granulometric distribution: Dv (10) of 0.24 μm, a value of Dv (50) of 0.36 μm, a value of Dv (90) of 0.53 μm, a value of Dv (97) of 0.60 μm. The granulometry was measured with a laser diffraction granulometer (Mastersizer 3000, Malvern Panalytical).

[0078] In this third example, according to the sixth embodiment of the invention, the first vehicle comprises a mixture comprising an esterified terephthalates and a trimethylolpropane esters. In particular, the esterified terephthalates is dipentyl terephthalate (DPT) and the trimethylolpropane esters comprises 1,1,1, tris-(hydroximethyl)-propane triheptanoate.

[0079] 1,1,1, tris-(hydroximethyl)-propane triheptanoate comprises a boiling point of 530° C., a molecular weight of 470.682 g/mol and a viscosity of 14 cSt at 40° C. The 1,1, tris-(hydroximethyl)-propane triheptanoate has the formula:

##STR00008##

[0080] DPT has a boiling point of 353° C., a molecular weight of 306.4 g/mol and a viscosity of 13.1 cSt at 40° C.

[0081] The additive used in the first example is a polyamide dispersant produced by LUBRIZOL LTD and known by the trade name SOLSPERSE J980.

[0082] The ink thus obtained has a surface tension of 28.1 mN/m (measured by capillary tensiometer) and a density of 145 g/l.

EXAMPLE 4

[0083] In the fourth example, the ink comprises the formulation given in Table 7.

TABLE-US-00007 TABLE 7 Component Percentage by weight (%) Solid part 40 First vehicle 31.7 Second vehicle 24.6 Additive 3.7

[0084] The solid part comprises particles having a maximum dimension equal to 1.2 μm with the following granulometric distribution: Dv (10) of 0.24 μm, a value of Dv (50) of 0.36 μm, a value of Dv (90) of 0.53 μm, a value of Dv (97) of 0.60 μm. The granulometry was measured with a laser diffraction granulometer (Mastersizer 3000, Malvern Panalytical). This fourth example has the peculiarity that the solid part comprises as major component, for example it is substantially composed by, Calcium Silicate (Wollastonite) as flux component. In this case the ink it is used as a glue for the application of a grit on the surface of ceramic tiles. In practice the grit is provided in solid form on the surface of the tile after printing of the ink so that the grit stick to the ink on the surface of the tile. The flux can help smelting of the grit. This kind of inks are also known as digital ceramic glues.

[0085] The first vehicle selected in the fourth example comprises dipentyl terephthalate (DPT) having the following formula:

##STR00009##

[0086] The first vehicle selected in the second example comprises a boiling point of 353° C. Moreover, the first vehicle selected in the second example comprises a molecular weight of 306.4 g/mol and a viscosity of 13.1 cSt at 40° C.

[0087] The second vehicle selected in the second example is dipropylene glycol n-butyl ether (DOW Dowanol DPnB). This vehicle comprises a boiling point equal to 230° C., molecular weight equal to 190° C. and viscosity at 40° C. equal to 3.4 cSt.

[0088] The additive used in the second example is a polyamide dispersant produced by LUBRIZOL LTD and known by the trade name SOLSPERSE J980. In this case the additive comprises also an organic pigment, for example being 0.5 wt % of the ink. The organic pigment act as a marker to see where the glue has been printed.

[0089] The ink thus obtained has a surface tension of 31 mN/m (measured by apillary tensiometer) and a density of 1300 g/l.