WO2018198887A1

WO2018198887A1 - Inks

Info

Publication number: WO2018198887A1
Application number: PCT/JP2018/015916
Authority: WO
Inventors: Masao Ikoshi
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2017-04-28
Filing date: 2018-04-17
Publication date: 2018-11-01
Anticipated expiration: 2019-10-28

Abstract

An aqueous ink-jet printing ink including at least: (a) 8-18 parts by weight (PBW) of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49; (b) 15-40 PBW of a water-miscible solvent having a boiling point lower than 240°C and comprising at least 40% ethylene glycol; (c) 0.1-10 PBW of a buffer; (d) 0.01-2.5 PBW of a non-ionic surfactant; (e) 4-14 PBW of urea; (f) 0-5 PBW of biocide; (g) 0-12 PBW of a solvent having a boiling point higher than 270°C; (h) 0-10 PBW of a solvent having a boiling point in a range of from 240°C to 270°C; and (i) a balance to 100 PBW of water. Also ink-jet printing processes, ink-jet ink containers, printed substrates, ink-sets and ink-jet printers.

Description

INKS

This invention relates to inks, a process for ink-jet printing, ink-jet ink containers, ink sets and ink-jet printers.

Ink-jet printing is a non-impact printing technique in which droplets of an ink are ejected through fine nozzles onto a substrate without bringing the nozzles into contact with the substrate.

Ink-jet printing is increasingly being used in the industrial sector where industrial ink-jet printers are required to work at high speeds. To achieve this a print-head for an industrial ink-jet printer will have multiple minute nozzles arranged at a high density on a face plate to enable high productivity single-pass printing with acceptable print resolutions.

Ink formulation for all forms of ink-jet printing is extremely demanding. It is especially difficult to formulate inks able to reliably work in these high speed single-pass print-heads.

The consequences of a blockage or failure of a single one of the tiny nozzles in a single-pass industrial ink-jet printer is potentially catastrophic since these print-heads are designed to work on high throughput media. Thus, a single nozzle not working could result in an unwanted white line appearing on an entire printing output which would then have to be discarded.

This new print-head technology has enabled ink-jet printing to be used in all printing applications including the printing of reactive dyes on to textiles.

One of the challenges in using ink printing technology on textiles is that the inks should dry as quickly as possible so the printed fabric can be rolled immediately after printing thus enabling a high throughput. Because of this inks based on low boiling solvents are preferred.

However inks based on low boiling solvents can dry quickly on the nozzle face plate and cause blockages with resultant jetting issues.

Solution to Problem
Thus, in the present disclosure the applicant has developed ink-jet inks based on low boiling solvents which are not only able to fire reliably through all types of single-pass print-head but also show the following benefits:
- use of the inks of the present disclosure minimises face-plate wetting;
- use of the inks of the present disclosure results in less frequent head replacement;
- use of the inks of the present disclosure results in less clogging on printer filters;
- use of the inks of the present disclosure lowers the energy required to dry the print in an online process;
- the inks of the present disclosure display excellent stability and resistance to crystal formation at low temperatures; and
- the inks of the present disclosure display excellent stability to hydrolysis which is crucial in their global transport.

The present invention provides:
(1) an aqueous ink-jet printing ink comprising:
(a) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
(b) from 15 to 40 parts by weight of a water-miscible solvent with a boiling point lower than 240°C and comprising at least 40% ethylene glycol;
(c) from 0.1 to 10 parts by weight of a buffer;
(d) from 0.01 to 2.5 parts by weight of a non-ionic surfactant;
(e) from 4 to 14 parts by weight of urea;
(f) from 0 to 5 parts by weight of biocide;
(g) from 0 to 12 parts by weight of a solvent having a boiling point higher than 270°C;
(h) from 0 to 10 parts by weight of a solvent having a boiling point in a range of from 240°C to 270°C; and
(i) a balance to 100 parts by weight of water.
All parts and percentages herein (unless stated otherwise) are by weight.
All boiling points (bp) are at 1 atmosphere pressure.

(2) The aqueous ink-jet printing ink as defined in (1), which is:
a cyan ink in which component (a) comprises C.I. Reactive Blue 72;
a magenta ink in which component (a) comprises C.I. Reactive Red 245;
a yellow ink in which component (a) comprises C.I. Reactive Yellow 95;
an orange ink in which component (a) comprises C.I. Reactive Orange 13;
a blue ink in which component (a) comprises C.I. Reactive Blue 49; or
a red ink in which component (a) comprises a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13.

(3) The aqueous ink-jet printing ink as defined in either (1) or (2), wherein component (b) comprises, in addition to the at least 40% ethylene glycol, one or more selected from the group consisting of dipropylene glycol, 1,3-butanediol and propylene glycol.

(4) The aqueous ink-jet printing ink as defined in any one of (1) to (3), wherein component (c) is a compound of the following Formula (1):
R¹R²N-Ar-(Z)_n
Formula (1)
wherein:
R¹ is H or an alkyl group and R² is an alkyl group, or R¹ and R² together with the N atom to which they are attached form a 5- or 6- membered ring;
Ar is a phenylene group;
Z is SO₃X or CO₂X;
X is H or a cation; and
n is 1 or 2.

(5) The aqueous ink-jet printing ink as defined in (4), wherein component (c) is N:N-diethylsulfanilic acid.

(6) The aqueous ink-jet printing ink as defined in any one of (1) to (5), wherein component (d) is 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof.

(7) The aqueous ink-jet printing ink as defined in any one of (1) to (6), wherein a total concentration of Ca and Mg in the ink is less than 300ppm.

(8) An aqueous ink-jet printing ink as defined in (1), comprising:
(a’) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
(b’) from 15 to 40 parts by weight of a water-miscible solvent selected from the group consisting of ethylene glycol, dipropylene glycol, 1,3 butanediol and propylene glycol and comprising at least 40% ethylene glycol;
(c’) from 0.2 to 1 part by weight of N:N-diethylsulfanilic acid;
(d’) from 0.1 to 1.5 parts by weight of 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof;
(e’) from 4 to 14 parts of urea;
(f’) from 0 to 1 part by weight of biocide;
(g’) from 0 to 12 parts by weight of glycerol or triethylene glycol or a mixture thereof;
(h’) from 0 to 8 parts by weight of 2-pyrrolidone; and
(j’) a balance to 100 parts water.

(9) A multicolour ink-set comprising:
a cyan ink that is the ink of (1) in which component (a) comprises C.I. Reactive Blue 72;
a magenta ink that is the ink of (1) in which component (a) comprises C.I. Reactive Red 245;
a yellow ink that is the ink of (1) in which component (a) comprises C.I. Reactive Yellow 95;
an orange ink that is the ink of (1) in which component (a) comprises C.I. Reactive Orange 13
a blue ink that is the ink of (1) in which component (a) comprises C.I. Reactive Blue 49; and
a red ink that is the ink of (1) in which component (a) comprises a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13.

(10) An ink-jet printing process, comprising printing the ink as described in any one of (1) to (8) or the inks of the multicolour ink-set as described in (9) onto a substrate using an ink-jet printer with single-pass print-head.

(11) The ink-jet printing process according to (10), wherein the ink-jet printer has a single-pass ink recirculating print-head.

(12) The ink-jet printing process according to (10), wherein the ink-jet printer has a single-pass non-recirculating print-head.

(13) The ink-jet printing process according to any one of (10) to (12), which is a textile material printing process comprising:
(a) optionally pre-treating a textile material;
(b) ink-jet printing a textile material with the ink according to any one of (1) to (8) or the multicolour ink-set as described in (9) using an ink-jet printer with a single-pass print-head;
(c) heat treating the printed textile material; and
(d) washing the heat treated printed textile material.

(14) A substrate printed with the ink as described in any one of (1) to (8).

(15) The substrate as defined in (14), which is a printed textile material.

(16) An ink-jet printer ink container tank comprising the ink-jet printing ink as described in any one of (1) to (8).

(17) An ink-jet printer with a single-pass print-head containing the ink-jet printing ink as described in any one of (1) to (8) or the multicolour ink-set as described in (9).

In this specification, a range of numerical values described using “(from) ... to ...” means a range including the numbers listed before and after “to” as a minimum value and a maximum value respectively.
Regarding ranges of numerical values that are gradationally described, the upper limit or the lower limit of one range of numerical values that is gradationally described may be substituted with the upper limit or the lower limit of another range of numerical values that is gradationally described. Further, the upper limit or the lower limit of a range of numerical values described herein may be substituted with the values shown in Examples.
In the case of referring to an amount of a certain component in a composition, in a case in which plural substances corresponding to the component are present in the composition, the amount of the component means a total amount of the plural substances which are present in the composition, unless otherwise specified.
"Percent (%) by mass" and "percent (%) by weight" have the same meaning, and "parts by mass" and "parts by weight" have the same meaning.
The term "step" includes not only an independent process, but also one that cannot be clearly distinguished from other process, as long as the predetermined action of this step is achieved thereby.
In regard to a description of a group (atomic group), a description that does not indicate substitution or unsubstitution is meant to include a group that does not have a substituent, as well as a group having a substituent. For example, an "alkyl group" is meant to include an alkyl group that does not have a substituent (unsubstituted alkyl group) as well as an alkyl group that has a substituent (substituted alkyl group).
A combination of two or more preferred features that are independently disclosed results in a further preferred feature.

<Aqueous ink-jet printing ink>
The aqueous ink-jet printing ink according to a first aspect of the present disclosure, which may be hereinafter referred to as "the aqueous ink(s)", "the ink(s)", "the ink-jet printing ink composition" or "the ink composition", includes:
a) from 8 to 18 parts by weight of a one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
b) from 15 to 40 parts by weight of water-miscible solvent with a boiling point less than 240°C including at least 40% ethylene glycol;
c) from 0.1 to 10 parts by weight of a buffer;
d) from 0.01 to 2.5 parts by weight of a non-ionic surfactant;
e) from 4 to 14 parts by weight of urea;
f) from 0 to 5 parts by weight of biocide;
g) from 0 to 12 parts by weight of a solvent with a boiling point greater than 270oC;
h) from 0 to 10 parts by weight of a solvent with a boiling point in the range of from 240°C to 270°C; and
i) the balance to 100 parts by weight water.
All parts and percentages herein (unless stated otherwise) are by weight.
All boiling points (bp) are at 1 atmosphere pressure.

(a) Dye
The ink of the present disclosure contains a dye, component (a), as a colorant. In embodiments, the ink is preferably a cyan ink which includes C.I. Reactive Blue 72 as a colorant, a magenta ink which includes C.I. Reactive Red 245 as a colorant, a yellow ink which includes C.I. Reactive Yellow 95 as a colorant, an orange ink which includes C.I. Reactive Orange 13 as a colorant, a blue ink which includes C.I. Reactive Blue 49 as a colorant or a red ink which includes a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13 as colorants.

The dye is present in an amount of from 8 to 18 parts by weight of the ink. The ink may provide sufficient color optical density of printed images by including the dye at 8 parts by weight or more. The ink may sufficiently prevent undesired color transfer from printed images formed thereby by limiting the amount of the dye to 18 parts by weight or less.

(b) Water-miscible solvent having bp<240°C
The ink contains 15 to 40 parts by weight of a low boiling point solvent as component (b). Component (b) may be any low boiling point solvent or mixture thereof, including at least 40% ethylene glycol, having a boiling point lower than 240°C which is suitable for use in an ink-jet ink. By including 40% parts by weight or more ethylene glycol in component (b), the ink may sufficiently prevent blockage or failure of nozzles of a recording head in an inkjet recording apparatus and thus provide fire reliability.

Preferably component (b) includes in addition to the at least 40% ethylene glycol (bp 197°C) one or more of dipropylene glycol (bp 232°C), 1,3-butanediol (bp 203°C) and propylene glycol (bp 188°C).

(c) Buffer
Component (c) may be any compatible buffer able to maintain the pH of the ink in the required range of pH 7 to 8.5, examples of such buffers include trishydroxymethylaminomethane (THAM), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), morpholinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), phosphate buffer solution, and tris(hydroxymethyl)aminomethane (Tris) buffer.

However, preferably, in component (c) the buffer is a compound of Formula (1):

R¹R²N-Ar-(Z)_n
Formula (1)

wherein in Formula (1):
R¹ is H or an alkyl group and R² is an alkyl group, or R¹ and R² together with the N atom to which they are attached form a 5- or 6- membered ring;
Ar is a phenylene group;
Z is SO₃X or CO₂X;
X is H or a cation; and
n is 1 or 2.

Preferably in the compound of Formula (1), R¹ and R² are each independently alkyl, or R¹ and R² together with the N atom to which they are attached form a 5- or 6- membered ring. More preferably R¹ and R² are each independently C_1-6-alkyl, especially ethyl.

When R¹ and R² together with the N atom to which they are attached form a 5- or 6- membered ring, the ring is preferably an optionally substituted morpholine, piperazine or piperidine. Preferred optional substituents are carboxy and sulfo.

Preferably the total number of carbon atoms in R¹ and R² added together is from 3 to 18, more preferably 3 to 12, especially 3 to 6.

Ar is preferably phenylene.

Z is preferably CO₂X.

X is preferably a cation, more preferably an alkali metal (especially Na⁺, K⁺ or Li⁺), ammonium or substituted ammonium cation.

Examples of compounds of Formula (1) include 4-chloro-N:N-diethylaniline sulfonic acid, N:N-di-n-hexylaniline-3-sulfonic acid, N-ethyl-N-n-hexylaniline disulfonic acids, 2-N:N-diethylaminonaphthalene-6-sulfonic acid, 2-(N-ethyl-N-benzylamino)-toluene-4-sulfonic acid, 2-N:N-diethylaminotoluene-4-sulfonic acid, N-ethyl-N-cyclohexylaniline-sulfonic acid, N-ethyl-N-betahydroxyethylaniline-sulfonic acid, N-ethyl-N-phenylbenzylaminomonosulfonic acid, 2-(N-ethyl-N-phenylamino)-ethanesulfonic acid, 2-(N-butyl-N-phenylamino)ethanesulfonic acid and 4:4’bis(diethylamino)diphenyl-2:2’-disulfonic acid. Because of their ease of manufacture and efficiency as buffers, the preferred compounds of Formula (1) are the lower N:N-dialkyl-derivatives of metanilic acid (aniline 3-sulfonic acid) and sulfanilic acid (aniline 4-sulfonic acid) especially N:N-diethylmetanilic acid, N:N-diethylsulfanilic acid, or the mixture of the two obtained by the sulfonation of diethylaniline with oleum. N:N-diethylsulfanilic acid is also known as N:N-diethyl-3-sulfoaminobenzene (DEAS).

Preferably component (c), the buffer, is N:N-diethylsulfanilic acid.

The amount of the buffer present in the ink may be arbitrarily set as long as it can maintain the pH of the ink in the required range, but it is typically from 0.1 to 10 parts by weight of the ink. In embodiments, preferably, the buffer is present in an amount of from 0.1 parts to 5 parts, more preferably of from 0.2 parts to 1 part, and especially of from 0.5 parts to 0.7 parts by weight of the ink composition.

(d) Non-ionic surfactant
The non-ionic surfactant, component (d), is not particularly limited. In embodiments, component (d) is preferably an acetylenic surfactant.

Any acetylenic surfactant may be used as component (d). However, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and ethylene oxide condensates thereof and 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol and ethylene oxide condensates thereof are preferred.

It is particularly preferred that the acetylenic surfactant is 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof. The surfactants 2,4,7,9-tetramethyl-5-decyne-4,7-diol and ethylene oxide condensates thereof are available as the SURFYNOL (registered trademark) range of surfactants from Air Products.

A single kind of surfactant or mixtures containing different surfactants may be used as the non-ionic surfactant.

The amount of the non-ionic surfactant present in the ink may be arbitrarily set as long as it can suitably adjust surface tension of the ink, but it is typically from 0.01 to 2.5 parts by weight of the ink. In embodiments, Component (d), the non-ionic surfactant, is preferably present in the range of from 0.1 parts to 1.5 parts by weight of the ink.

(e) Urea
The ink contains 4 to 14 parts by weight of urea as component (e). The ink may sufficiently provide fire reliability by including 4 to 14 parts by weight of urea, in which blockage or failure in an inkjet recording due to drying of nozzles of a recording head apparatus may be prevented. In addition, the ink may display resistance to dye crystal formation at low temperatures by including 4 parts by weight or more of urea, and the ink may sufficiently prevent color shade change which may occur due to aging of the ink.

(f) Biocide
In embodiments, the ink may contain a biocide, as component (f), if necessary. Component (f), the biocide, may be any biocide (or mixture of biocides) which is stable in the ink. It is particularly preferred that the biocide includes 1,2-benzisothazolin-3-one which is available as a 20% active solution from Lonza as PROXEL (registered trademark) GXL and BIOBAN (registered trademark) DXN (2,6-dimethyl-1,3-dioxan-4-yl acetate), from Dow Chemical Company.

The level of biocide in the ink depends on which biocide is used. However, typically the biocide is present in a range of 0 to 5 parts by weight of the ink, and preferably in a range of 0 to 1 part by weight of the ink, and more preferably in a range of from 0.01 to 1 part by weight of the ink.

A biocide may not be required (namely, the content of a biocide in the ink can be zero parts) if the ink is prepared immediately before use but will be an essential component if the ink is to be stored or kept for any length of time.

(g) Solvent with bp>270°C
Although the ink may be free of a solvent having a boiling point higher than 270°C, the ink may contain such a solvent, as component (g), in embodiments if necessary. Component (g) may be any solvent having a boiling point higher than 270°C which is suitable for use in an ink-jet ink. A single kind of the solvent or mixture of these solvents may be used in the inks of the present disclosure.

Preferably component (g) includes glycerol (bp 290°C) or triethylene glycol (bp 287°C) or a mixture thereof. More preferably component (g) includes glycerol.

(h) Solvent with bp: 240-270°C
Although the ink may be free of a solvent having a boiling point in the range of from 240°C to 270°C, the ink may contain such a solvent, as component (h), in embodiments as necessary. Component (h) may be any solvent having a boiling point in the range of from 240°C to 270°C which is suitable for use in an ink-jet ink.
Component (h) is not particularly limited. In embodiments, component (h) preferably includes 2-pyrrolidone (bp 245°C). A single kind of the solvent or mixture of these solvents may be used in the inks of the present disclosure.

Preferably component (h) is present in the range of from 3 to 7 parts by weight of the ink.

(i) Water
The ink-jet printing ink of the present disclosure includes water. A content of water in the ink is not particularly restricted. In embodiments, the ink preferably includes at least 20% water and more preferably at least 25% water. Any source of precipitate free high quality water may be used in the inks of the present disclosure. Preferably the water is deionised water.

Preferably the pH of the ink-jet printing ink is in the range of from between pH 6 to 9 and more preferably of from between pH 7 to 8.5.

The ink-jet printing ink preferably has a surface tension of from 20 dynes/cm to 50 dynes/cm, more preferably of from 25 dynes/cm to 50 dynes/cm and especially of from 30 dynes/cm to 40 dynes/cm, when measured at 25°C using a tensiometer AquaPi (trade name, manufactured by Kibron Inc.).

Preferably, the ink-jet printing ink has been filtered through a filter having a mean pore size of less than 10 microns, more preferably less than 5 microns and especially less than 1 micron.

Preferably, the ink-jet printing ink has a total concentration of Ca plus Mg in the ink of less than 300 ppm, more preferably less than 100 ppm and especially less than 50 ppm.

In addition to the above mentioned components, the ink-jet printing ink composition may optionally include one or more ink additives. Preferred additives suitable for ink-jet printing inks are anti-kogation agents, rheology modifiers, corrosion inhibitors and chelating agents.
Preferably, the total amount of additives is no more than 10 parts by weight of the ink.

These additives and additional dyes are added to and include part of component (i), the water added to the ink-jet printing ink.

In a preferred embodiment the ink-jet printing ink includes:
a’) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
b’) from 15 to 40 parts by weight of a water-miscible solvent selected from one or more of the group consisting of dipropylene glycol, 1,3 butanediol and propylene glycol and including at least 40% ethylene glycol;
c’) from 0.2 to 1 part by weight of N:N-diethylsulfanilic acid;
d’) from 0.1 to 1.5 parts by weight of 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof;
e’) from 4 to 14 parts of urea;
f’) from 0 to 1 part by weight of biocide;
g’) from 0 to 12 parts by weight of glycerol or triethylene glycol or a mixture thereof;
h’) from 0 to 8 parts by weight of 2-pyrrolidone; and
i’) a balance to 100 parts of water.

A more preferred ink-jet printing ink of the present disclosure includes:
a’) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
b’) from 15 to 40 parts by weight of a water-miscible solvent selected from the group consisting of dipropylene glycol, 1,3 butanediol and propylene glycol and including at least 40% ethylene glycol;
c’) from 0.2 to 1 part by weight of N:N-diethylsulfanilic acid;
d’) from 0.1 to 1.5 parts by weight of 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof;
e’) from 4 to 14 parts of urea;
f’) from 0.1 to 1 part by weight of biocide;
g’) from 0 to 12 parts by weight of glycerol or triethylene glycol or a mixture thereof;
h’) from 3 to 7 parts by weight of 2-pyrrolidone; and
i’) a balance to 100 parts of water.

<Multicolour ink-set>
A second aspect of present disclosure includes a multicolour ink-set including at least two inks, at least one ink among which being the ink as described in the first aspect of present disclosure. In embodiments, the ink-set is a multicolour ink-set including inks as described in the first aspect of present disclosure where a cyan ink includes C.I. Reactive Blue 72 as a colorant, a magenta ink includes C.I. Reactive Red 245 as a colorant, a yellow ink includes C.I. Reactive Yellow 95 as a colorant, an orange ink includes C.I. Reactive Orange 13 as a colorant, a blue ink which includes C.I. Reactive Blue 49 as a colorant and a red ink which includes a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13 as colorants.

The multicolour ink-set of the second aspect of present disclosure may include additional inks as described in the first aspect of present disclosure.

The multicolour ink-set of the second aspect of present disclosure may also include additional inks not as described in the first aspect of present disclosure. Thus, for example it may also contain a black ink, a grey ink, a green ink and variants on the ink described above with alternate colorants.

<Ink-jet printing process>
A third aspect of present disclosure provides an ink-jet printing process wherein the ink-jet printing ink according to the first aspect of present disclosure or the inks of the multicolour ink-set according to the second aspect of present disclosure is/are printed onto a substrate by means of an ink-jet printer.

The process of the present disclosure may use any ink-jet printer, preferably with a single-pass print-head.

Thus the third aspect of present disclosure provides an ink-jet printing process wherein the ink as described in the first aspect of present disclosure or the multicolour ink-set according to the second aspect of present disclosure is printed onto a substrate using an ink-jet printer with single-pass print-head.

One preferred type of single-pass print-head has an ink re-circulation channel in the ink supply system. This channel allows for fresh ink to be available for jetting and can be part of the ink supply system or even specially engineered channels which run behind the nozzle plate. It is preferred that the ink supply system runs behind the nozzle plate as this allows for the use of more volatile inks whilst not compromising restart/latency behaviour. Print-heads of this type are available from Fujifilm Dimatix.

Recirculating print-heads are usually equipped with a reservoir heater and a thermistor to control the jetting temperature. It is preferred that the viscosity of the ink-jet printing ink at the jetting temperature is in the range of from 3 to 20 mPa s and more preferably in a range of from 3 to 12 mPa s.

Thus in a first preferred embodiment of the second aspect of present disclosure the ink-jet printer has a single-pass ink recirculating print-head.

A second preferred type of single-pass print-head is a non-recirculating print-head. Print-heads of this type are available from Kyocera.

Non-recirculating print-heads are also usually equipped with a reservoir heater and a thermistor to control the jetting temperature. It is preferred that the viscosity of the ink-jet printing ink at the jetting temperature for print-heads of this type is in the range of from 3 to 7 mPa s.

Viscosity is as would be measured using a Brookfield DV-II or DV-II+ digital viscometer with UL-adapter and water jacket and spindle S00 at 3 rpm. DV-II, DV-II+, UL-adapter and S00 are all trade names from Brookfield Engineering Laboratories Inc.

Thus in the second preferred embodiment of the third aspect of present disclosure the ink-jet printer has a single-pass ink non-recirculating print-head.

Preferably the ink-jet printing ink of the first aspect of present disclosure is applied at a temperature in excess of 30°C.

The substrate is preferably paper, plastic, metal or glass and more preferably a textile material.

The textile material may be of natural or synthetic fibers including blends thereof. Thus, it may be cellulose, including viscose rayon and regenerated viscose rayon, wool, acrylic, polyamide such as nylon, polyester such as polyethyleneglycolterephthalate or polyurethane. It is, however, preferably cellulose or a blend thereof.

The textile material is preferably woven or knitted or in the form of dry or wet laid fibers. It may be in the form of sheets, webs, threads or ready made up garments such as drapes, shirting, toweling, underwear, socks and sheeting.

Preferably the textile material has been impregnated with a pre-treatment composition including components such as a color enhancing agent; an alkali metal hydroxide, carbonate, bicarbonate or a mixture thereof; a thickener, such as sodium alginate and water.

In the textile printing process according to the third aspect of present disclosure if the textile material has not been impregnated with a pre-treatment agent to enhance the dyeing process then a pre-treatment step is required.

The pre-treatment step requires that the textile material is treated with a pre-treatment liquid containing at least one of an alkali agent, such as sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, trisodium phosphate, and sodium acetate, and a hydrotropic agent such as urea.

The pre-treatment liquid may also contain a sizing agent, for example: starch materials such as corn and wheat; cellulose based materials such as carboxymethyl cellulose and hydroxymethyl cellulose; polysaccharides such as sodium alginate, gum arabic, locust bean gum, gum tragacanth, guar gum, and tamarind seed; proteins such as gelatin and casein; natural water-soluble polymers such as tannin and lignin; and synthetic water-soluble polymers such as polyvinyl alcohol-based compounds, polyethylene oxide-based compounds, acrylic acid-based compounds, and maleic anhydride-based compounds.

Other components which may be present in the pre-treatment liquid include an anti-reduction agent, a preservative, a fungicide, a chelating agent, a pH adjusting agent, a thickening agent such as an alginate and a surfactant.

The exact composition of the pre-treatment liquid will depend on the printing regime and nature of the textile material.

The pre-treatment liquid may be applied to the textile material by any suitable method. Thus, the textile material may be immersed in the pre-treatment liquid, coated by means of a pad batch method, roll coater or the like, sprayed, or applied by an ink-jet printer.

The pre-treated textile material is then allowed to dry.

In the process of the third aspect of present disclosure the textile material is then printed using an ink-jet printer, preferably an ink-jet printer with a single-pass head as described above.

Following the printing step the printed textile material is preferably subjected to a heat treatment step. The heat treatment step may utilize any method known in the art such as a high temperature steaming or high pressure steaming. To minimise any possible damage to the textile material the temperature in the heat treatment step is preferably in a range of from 90°C to 110°C.

The printed textile material is then washed to remove any excess dye. The washing step uses water though soaping treatment may be used in some instances.

Thus, a preferred ink-jet printing process of the third aspect of present disclosure is a textile material printing process including the following steps:
a) optionally pre-treating a textile material;
b) ink-jet printing the textile material with an ink-jet printing ink as described in the first aspect of present disclosure or a multicolour ink-set according to the second aspect of present disclosure, preferably using an ink-jet printer with a single-pass print-head, as described and preferred above;
c) heat treating the printed textile material; and
d) washing the heat treated printed textile material.

<Printed substrate>
A fourth aspect of the present disclosure provides a substrate printed by an ink-jet printing process as described in the third aspect of present disclosure using an ink-jet printing ink as described in the first aspect of present disclosure or a multicolour ink-set according to the second aspect of present disclosure. The substrate is as described and preferred in the third aspect of present disclosure. Thus, the preferred printed substrate is a textile material.

<Ink-jet printer ink container>
According to a fifth aspect of the present disclosure there is provided an ink-jet printer ink container (e.g. a cartridge or a larger ink tank), including an ink-jet printing ink as described in the first aspect of the present disclosure.

<Ink-jet printer>
A sixth aspect of the present disclosure provides an ink-jet printer with a single-pass print-head, as described in the third aspect of present disclosure, containing an ink-jet printing ink as described in the first aspect of present disclosure or a multicolour ink-set according to the second aspect of present disclosure.

EXAMPLES

The present disclosure will now be illustrated by the following examples, but the invention is not limited thereto. The numerical values expressed by "part" or "%" in the following description are by weight unless stated to the contrary.

The ink compositions 1 to 34 and comparative ink compositions C1 to C14 shown in Tables 1-1 to 1-9 were prepared, filtered through a 1.0μm pore size membrane and evaluated using the following test protocols. Ink composition C13 was prepared and evaluated in the same manner as ink composition C10 except that ink composition C13 was heated at 60°C for 7 days before being subject to the evaluations.

The following abbreviations were used in the Tables:
EG - ethylene glycol
DPG - dipropylene glycol
1,3-B - 1,3-butanediol
PG - propylene glycol
G - glycerol
TEG - triethylene glycol
2-P - 2-pyrrolidone
S-465 - SURFYNOL (registered trademark) 465
S-440 - SURFYNOL (registered trademark) 440
DEAS - N:N-diethylsulphanilic acid
DI - Deionised water
RB 72 - C.I. Reactive Blue 72
RR 245 - C.I. Reactive Red 245
RY95 - C.I. Reactive Yellow 95
RO13 - C.I. Reactive Orange 13
RB 49 - C.I. Reactive Blue 49

SURFYNOL (registered trademark) 440 is 2,4,7,9-tetramethyl-5-decyne-4,7-diol from Air Products.
SURFYNOL (registered trademark) 465 is an ethylene oxide condensate of 2,4,7,9-tetramethyl-5-decyne-4,7-diol from Air Products.
C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49 were obtained from Dystar.

Evaluations
1. Print OD
A pre-coat solution containing 66.3% water, 20.0% urea, 12.0% soda-ash and 1.7% sodium alginate was prepared and filtered through a 10μm pore size membrane filter.

The pre-coat solution was applied to the front and back of a 100% cotton fabric by Pad Batch (60% wet pick-up) and dried at ambient condition overnight.

The substrate was printed using a printer with a Fujifilm Dimatix Samba single-pass print-head. Three different drop volumes (2.3pl, 4.5pl, 9.0pl) were applied at 100% duty solid image (1200 x 1200dpi). The printed samples were dried at 25°C for 30min. The samples were then steam treated at 100°C for 10min. They were then washed with cold water for 2 min, with 90°C hot water for 10min and finally with cold water for 2 min. The samples were then allowed to dry at room temperature.

The optical properties of the printed substrate (optical density: OD) were then measured with a spectrophotometer (trade name: X-Rite eXact, manufactured by X-Rite Inc.). The prints were evaluated as follows. Herein, grade B or higher is deemed as acceptable.

2. Color transfer
A pre-coat solution containing 66.3% water, 20.0% urea, 12.0% soda-ash and 1.7% sodium alginate was prepared and filtered through a 10μm pore size membrane filter.

The substrate was printed using a printer with a Fujifilm Dimatix Samba single-pass print-head. Three different drop volumes (2.3pl, 4.5pl, 9.0pl) were applied at 100% duty solid image (1200 x 1200dpi). The printed samples were dried at 25°C for 1min. An unprinted white substrate was then placed on the printed sample and a pressure of 0.98N/cm² was applied for 3 seconds. Colour transfer to the white substrate was assed visually, in which grade B or higher is deemed as acceptable.

Evaluation Criteria
AA : no color transfer is seen at 9.0pl sample
A : slight color transfer is seen at 9.0pl sample
B : slight color transfer is seen at 4.5pl sample
C : some extent of color transfer is seen at 4.5pl sample
D : color transfer is seen clearly at 2.3pl sample

3. Jetting Failure by Drying (Open Cap Evaluation)
In this evaluation a single-pass Kyocera KJ4B (trade name) print-head (drop volume of 4.5pl) was used.

An initial print on HP Advanced Photo Paper (trade name) of the nozzle check image of all 2656 nozzles, on the print-head, was carried out. The print-head was then left uncapped for 30min before nozzle check image was reprinted and the delay of jets after firing signals was determined. This delay is defined as D (mm) , in which grade B or higher is deemed as acceptable.

4. Colour Shade Change
Print samples on a cotton substrate were prepared as described in protocol 1, above, using freshly made ink and ink aged for 7 days at 60°C. The optical properties of the printed substrates (OD, L*, a* and b*) were then measured with a X-Rite eXact (trade name). The change in the color shade ΔE was then calculated as shown below. Herein, grade A or higher is deemed as acceptable.

5. Dye Crystallization test
Ink (20g) was placed in 20ml glass sample bottle and stored at 0°C for 14 days, and crystal formation was assessed visually. Herein, grade A or higher is deemed as acceptable.

Evaluation Criteria
A : No Crystal
D : Crystal is seen

Inks according to the present disclosure and Comparative inks were evaluated using these protocols and the results are shown in Tables 3-1 and 3-2 below. From these results it is clear that the inks of the present disclosure display superior properties.

The disclosure of U.S. Provisional Application No. 62/491,305, filed April 28, 2017, is incorporated herein by reference in its entirety.
All literatures, patents, patent applications, and technical standards described herein are herein incorporated by reference to the same extent as if each individual literature, patent, patent application, or technical standard was specifically and individually indicated as being incorporated by reference.

Claims

An aqueous ink-jet printing ink comprising:
(a) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
(b) from 15 to 40 parts by weight of a water-miscible solvent having a boiling point lower than 240°C and comprising at least 40% ethylene glycol;
(c) from 0.1 to 10 parts by weight of a buffer;
(d) from 0.01 to 2.5 parts by weight of a non-ionic surfactant;
(e) from 4 to 14 parts by weight of urea;
(f) from 0 to 5 parts by weight of biocide;
(g) from 0 to 12 parts by weight of a solvent having a boiling point higher than 270°C;
(h) from 0 to 10 parts by weight of a solvent having a boiling point in a range of from 240°C to 270°C; and
(i) a balance to 100 parts by weight water.
The aqueous ink-jet printing ink as claimed in claim 1, which is:
a cyan ink in which component (a) comprises C.I. Reactive Blue 72;
a magenta ink in which component (a) comprises C.I. Reactive Red 245;
a yellow ink in which component (a) comprises C.I. Reactive Yellow 95;
an orange ink in which component (a) comprises C.I. Reactive Orange 13;
a blue ink in which component (a) comprises C.I. Reactive Blue 49; or
a red ink in which component (a) comprises a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13.
The aqueous ink-jet printing ink as claimed in either claim 1 or claim 2, wherein component (b) comprises, in addition to the at least 40% ethylene glycol, one or more selected from the group consisting of dipropylene glycol, 1,3-butanediol and propylene glycol.
The aqueous ink-jet printing ink as claimed in any one of claims 1 to 3, wherein component (c) is a compound of the following Formula (1):

R¹R²N-Ar-(Z)_n
Formula (1)

wherein:
R¹ is H or an alkyl group and R² is an alkyl group, or R¹ and R² together with the N atom to which they are attached form a 5- or 6- membered ring;
Ar is a phenylene group;
Z is SO₃X or CO₂X;
X is H or a cation; and
n is 1 or 2.
The aqueous ink-jet printing ink as claimed in claim 4, wherein component (c) is N:N-diethylsulfanilic acid.
The aqueous ink-jet printing ink as claimed in any one of claims 1 to 5, wherein component (d) is 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof.
The aqueous ink-jet printing ink as claimed in any one of claims 1 to 6, wherein a total concentration of Ca and Mg in the ink is less than 300ppm.
An aqueous ink-jet printing ink as claimed in claim 1, comprising:
(a’) from 8 to 18 parts by weight of one or more dyes selected from the group consisting of C.I. Reactive Blue 72, C.I. Reactive Red 245, C.I. Reactive Yellow 95, C.I. Reactive Orange 13 and C.I. Reactive Blue 49;
(b’) from 15 to 40 parts by weight of a water-miscible solvent selected from the group consisting of ethylene glycol, dipropylene glycol, 1,3 butanediol and propylene glycol and comprising at least 40% ethylene glycol;
(c’) from 0.2 to 1 part by weight of N:N-diethylsulfanilic acid;
(d’) from 0.1 to 1.5 parts by weight of 2,4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof;
(e’) from 4 to 14 parts of urea;
(f’) from 0 to 1 part by weight of biocide;
(g’) from 0 to 12 parts by weight of glycerol or triethylene glycol or a mixture thereof;
(h’) from 0 to 8 parts by weight of 2-pyrrolidone; and
(j’) a balance to 100 parts water.
A multicolour ink-set comprising:
a cyan ink that is the ink of claim 1 in which component (a) comprises C.I. Reactive Blue 72;
a magenta ink that is the ink of claim 1 in which component (a) comprises C.I. Reactive Red 245;
a yellow ink that is the ink of claim 1 in which component (a) comprises C.I. Reactive Yellow 95;
an orange ink that is the ink of claim 1 in which component (a) comprises C.I. Reactive Orange 13
a blue ink that is the ink of claim 1 in which component (a) comprises C.I. Reactive Blue 49; and
a red ink that is the ink of claim 1 in which component (a) comprises a mixture of C.I. Reactive Red 245 and C.I. Reactive Orange 13.
An ink-jet printing process, comprising printing the ink as described in any one of claims 1 to 8 or the inks of the multicolour ink-set as described in claim 9 onto a substrate using an ink-jet printer with single-pass print-head.
The ink-jet printing process according to claim 10, wherein the ink-jet printer has a single-pass ink recirculating print-head.
The ink-jet printing process according to claim 10, wherein the ink-jet printer has a single-pass non-recirculating print-head.
The ink-jet printing process according to any one of claims 10 to 12, which is a textile material printing process comprising:
(a) optionally pre-treating a textile material;
(b) ink-jet printing a textile material with the ink according to any one of claims 1 to 8 or the multicolour ink-set as described in claim 9 using an ink-jet printer with a single-pass print-head;
(c) heat treating the printed textile material; and
(d) washing the heat treated printed textile material.
A substrate printed with the ink as described in any one of claims 1 to 8.
The substrate as claimed in claim 14, which is a printed textile material.
An ink-jet printer ink container tank comprising the ink-jet printing ink as described in any one of claims 1 to 8.
An ink-jet printer with a single-pass print-head containing the ink-jet printing ink as described in any one of claims 1 to 8 or the multicolour ink-set as described in claim 9.