U.S. patent application number 14/022496 was filed with the patent office on 2014-03-13 for pretreatment of textile for inkjet printing.
This patent application is currently assigned to E I DU PONT DE NEMOURS AND COMPANY. The applicant listed for this patent is E I DU PONT DE NEMOURS AND COMPANY. Invention is credited to SCOTT W. ELLIS.
Application Number | 20140068877 14/022496 |
Document ID | / |
Family ID | 50231706 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140068877 |
Kind Code |
A1 |
ELLIS; SCOTT W. |
March 13, 2014 |
PRETREATMENT OF TEXTILE FOR INKJET PRINTING
Abstract
This invention pertains to inkjet printing on textile including
using a pretreatment solution containing poly(acrylic) acid,
hydrophilic copolymers of poly(acrylic) acid or mixtures thereof to
control bleed.
Inventors: |
ELLIS; SCOTT W.;
(Wilmington, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
E I DU PONT DE NEMOURS AND COMPANY |
Wilmington |
DE |
US |
|
|
Assignee: |
E I DU PONT DE NEMOURS AND
COMPANY
Wilmington
DE
|
Family ID: |
50231706 |
Appl. No.: |
14/022496 |
Filed: |
September 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61700531 |
Sep 13, 2012 |
|
|
|
Current U.S.
Class: |
8/467 |
Current CPC
Class: |
D06P 5/30 20130101; D06P
1/5257 20130101; D06P 1/54 20130101; D06P 5/22 20130101; D06P 1/44
20130101 |
Class at
Publication: |
8/467 |
International
Class: |
D06P 5/22 20060101
D06P005/22 |
Claims
1. A method of digitally printing :textile comprising the steps of:
(a) pretreating said textile with an aqueous pretreatment solution
comprising a bleed control agent selected from the group consisting
of poly(acrylic) acid, hydrophilic copolymers of poly(acrylic) acid
and mixtures thereof; (b) drying the pretreated textile; and (c)
digitally printing the dried, pretreated textile with a colored ink
jet ink; wherein said bleed control agent is present in an amount
less than 5% by weight based on the weight of said pretreatment
solution, and said ink jet ink comprises a pigment, a dispersant to
disperse said pigment, and a polymeric binder, and said binder is
cross-linked with a cross-linking agent or cross-linking groups
present in said textile.
2. The method of claim 1, optionally comprising an additional post
printing step of curing with melamine at a temperature greater than
180.degree. C.
3. The method of claim 2, wherein said bleed control agent has a pH
of between 2 and 5.
4. The method of claim 3, wherein said textile is a synthetic
material.
5. The method of claim 4, wherein said cross-linking agent is an
epoxide.
6. The method of claim 5, wherein said pretreatment solution
farther comprises a surfactant.
7. The method of claim 6, wherein said pretreatment solution has a
viscosity of less than 4 cPs.
8. The method of claim 4, wherein said cross-linking agent is an
epoxide.
9. The method of claim 9, wherein said pretreatment solution
farther comprises a surfactant.
10. The method of claim 10, wherein pretreatment solution has a
viscosity of less than 4 cPs.
11. The method of claim 1, wherein said polymeric binder is a
polyurethane.
12. The method of claim 11, wherein said bleed control agent has a
pH of between 2 and 5.
13. The method of claim 12, wherein said textile is a synthetic
material.
14. The method of claim 13, wherein said cross-linking agent is an
epoxide.
15. The method of claim 14, wherein said pretreatment solution
further comprises a surfactant.
16. The method of claim 15, wherein said pretreatment solution has
a viscosity of less than 4 cPs.
17. The method of claim 13, wherein said cross-linking agent is a
carbodiimide.
18. The method of claim 17, wherein said pretreatment solution
further comprises a surfactant.
19. The method of claim 18, wherein said pretreatment solution has
a viscosity of less than 4 cPs.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
from U.S. Provisional Application Ser. No. 61/700531, filed Sep.
13, 2012, which is incorporated by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
[0002] This invention pertains to inkjet printing on a pretreated
fabric with pigmented inkjet inks, and to a pretreatment solution
for the fabric that allows high quality printing thereon.
[0003] Digital printing methods such as inkjet printing are
becoming increasingly important for the printing of textiles and
offer a number of potential benefits over conventional printing
methods such as screen printing. Digital printing eliminates the
set up expense associated with screen preparation and can
potentially enable cost effective short run production. Inkjet
printing furthermore allows visual effects such as tonal gradients
and infinite pattern repeat sizes that cannot be practically
achieved with a screen printing process.
[0004] Bleed of one color into another is a typical problem in ink
jet printing because inks have relatively low viscosity and tend to
spread especially for inkjet printers having capability of printing
three or four primary colors in a simultaneous (or near
simultaneous) fashion. Such bleed of one printing liquid into an
adjacent printing liquid results in production of indistinct images
with a poor degree of resolution.
[0005] Various methods have been proposed to prevent bleed of
adjacent printing liquids. One method is to apply the two printing
liquids at a distance from one another so that no intermingling or
mixing of the printing liquids can occur. However, this method
produces images of poor resolution. Another method involves a delay
in applying the second printing liquid until the first printing
liquid is completely dry. This method is disadvantageous due to its
inefficiencies. Yet another approach to control bleed is to
increase the rate of penetration of the printing liquid into the
substrate, but this causes a reduction of optical density.
[0006] U.S. Patent Application Publication No. 2007/0011819
discloses a composition containing an ink receptor, a surfactant, a
flame retardant and a fluorescent whitening agent to pretreat
textiles.
[0007] U.S. Pat. No. 5,785,743 discloses the use of an organic acid
component in one ink to pair with another ink containing a pH
sensitive colorant to reduce bleed for printing on paper.
[0008] A need exists for a textile pretreatment composition that
can accommodate all the various factors such as weave, weight and
any other applied treatment from manufacturer that impact image
quality. The present disclosure satisfies this need by a providing
a textile pretreatment composition to reduce bleed on natural and
unnatural fibers.
SUMMARY OF THE DISCLOSURE
[0009] An embodiment provides a method of digitally printing a
textile comprising the steps of: [0010] (a) pretreating said
textile with an aqueous pretreatment solution comprising a bleed
control agent selected from the group consisting of poly(acrylic)
acid, hydrophilic copolymers of poly(acrylic) acid and mixtures
thereof; [0011] (b) drying the pretreated textile; and [0012] (c)
digitally printing the dried, pretreated textile with a colored ink
jet ink; wherein said bleed control agent is present in an amount
less than 5% by weight based on the weight of said pretreatment
solution, and said ink jet ink comprises a pigment, a dispersant to
disperse said pigment, and a polymeric binder, and said binder is
cross-linked with a cross-linking agent or cross-linking groups
present in said textile.
[0013] Another embodiment provides that the method optionally
comprising an additional post printing step of curing with melamine
at a temperature greater than 180.degree. C.
[0014] Another embodiment provides that the bleed control agent has
a pH of between 2 and 5.
[0015] Another embodiment provides that the textile is a synthetic
material.
[0016] Another embodiment provides that the cross-linking agent is
an epoxide.
[0017] Another embodiment provides that the pretreatment solution
further comprises a surfactant.
[0018] Another embodiment provides that the pretreatment solution
has a viscosity of less than 4 cPs.
[0019] Another embodiment provides that the polymeric binder is a
polyurethane.
[0020] Yet another embodiment provides that the cross-linking agent
is a carbodiimide.
[0021] These and other features and advantages of the present
embodiments will be more readily understood by those of ordinary
skill in the art from a reading of the following Detailed
Description. Certain features of the disclosed embodiments which
are, for clarity, described above and below as separate
embodiments, may also be provided in combination in a single
embodiment. Conversely, various features of the disclosed
embodiments that are described in the context of a single
embodiment, may also be provided separately or in any
subcombination.
DETAILED DESCRIPTION
[0022] Unless otherwise stated or defined, all technical and
scientific terms used herein have commonly understood meanings by
one of ordinary skill in the art to which this disclosure
pertains.
[0023] Unless stated otherwise, all percentages, parts, ratios,
etc., are by weight.
[0024] When an amount, concentration, or other value or parameter
is given as either a range, preferred range or a list of upper
preferable values and lower preferable values, this is to be
understood as specifically disclosing all ranges formed from any
pair of any upper range limit or preferred value and any lower
range limit or preferred value, regardless of whether ranges are
separately disclosed. Where a range of numerical values is recited
herein, unless otherwise stated, the range is intended to include
the endpoints thereof, and all integers and fractions within the
range.
[0025] When the term "about" is used in describing a value or an
end-point of a range, the disclosure should be understood to
include the specific value or end-point referred to.
[0026] As used, herein, the term "dispersion" means a two phase
system wherein one phase consists of finely divided particles
(often in a colloidal size range) distributed throughout a bulk
substance, the particles being the dispersed or internal phase and
the bulk substance being the continuous or external phase.
[0027] As used herein, the term "dispersant" means a surface active
agent added to a suspending medium to promote uniform and maximum
separation of extremely fine solid particles often of colloidal
sizes. For pigments, the dispersants are most often polymeric
dispersants, and the dispersants and pigments are usually combined,
using a dispersing equipment.
[0028] As used herein, the term "OD" means optical density.
[0029] As used herein, the term "aqueous vehicle" refers to water
or a mixture of water and at least one water-soluble, or partially
water-soluble (i.e., methyl ethyl ketone), organic solvent
(co-solvent).
[0030] As used herein, the term "substantially" means being of
considerable degree, almost all.
[0031] As used herein, the term "dyne/cm" means dyne per
centimeter, a surface tension Unit.
[0032] As used herein, the term "cP" means centipoise, a viscosity
unit.
[0033] As used herein, the term "mPas" means millipascal second, a
viscosity unit.
[0034] As used herein, the term "mNm.sup.-1" means milliNewtons per
meter, a surface tension unit.
[0035] As used herein, the term "mScm.sup.-1" means milliSiemens
per centimeter, a conductivity unit.
[0036] As used herein, the term "EDTA" means
ethylenediaminetetraacetic acid.
[0037] As used herein, the term "IDA" means iminodiacetic acid.
[0038] As used herein, the term "EDDHA" means
ethylenediamine-di(o-hydroxyphenylacetic acid).
[0039] As used herein, the term "DHEG" means
dihydroxyethylglycine.
[0040] As used herein, the term "DTPA" means
diethylenetriamine-N,N,N',N'',N''-pentaacetic acid.
[0041] As used herein, the term "GEDTA" means
glycoletherdiamine-N,N,N',N'-tetraacetic acid.
[0042] As used herein, Surfynol.RTM. 465 is a surfactant from Air
Products (Allentown, Pa., U.S.A.).
[0043] As used herein, the term "RMSD" refers to root mean square
deviation.
[0044] As used herein, the term "jettability" means good jetting
properties with no clogging or deflection during printing.
[0045] As used herein, the term "DTG" means direct to garment.
[0046] Unless otherwise noted, the above chemicals were obtained
from Aldrich (Milwaukee, Wis., U.S.A.) or other similar suppliers
of laboratory chemicals.
[0047] The materials, methods, and examples herein are illustrative
only except as explicitly stated, and are not intended to be
limiting.
Pretreatment Solution
[0048] The pretreatment solution used in the method of the present
disclosure contains a bleed control agent selected from the group
consisting of poly(acrylic) acid, hydrophilic copolymers of
poly(acrylic) acid and mixtures thereof. Typically, the
pretreatment solution comprises a solution of a poly(acrylic) acid,
hydrophilic copolymers of poly(acrylic) acid or mixtures of
poly(acrylic) acid, hydrophilic copolymers of poly(acrylic) acid in
water. Other organic ingredients such as co-solvents, swelling
agents, coalescing agents, viscosity modifiers, typically, will not
be included in the pretreatment solution. Optionally, the
pretreatment solution contains a surfactant. Co-solvent(s) may be
present when a surfactant is employed. Ingredient percentages of
the bleed control agent and the surfactant herein are weight
percent based on the total weight of the pretreatment solution,
unless otherwise indicated.
[0049] The bleed control agent is included in the pretreatment
solution in an effective amount to control bleed relative to
without the bleed control agent. Typically, the bleed control agent
is present in the pretreatment solution at a level of at least
about 0.2 by weight based on the total weight of the pretreatment
solution. The upper level is not limited, but is dictated by
considerations such as compatibility with other ink components. In
one embodiment, the bleed control agent is present in a range of
0.1% to 5 based on the total weight of the pretreatment solution.
In another embodiment, the bleed control agent is present in a
range of 0.2% to 4% based on the total weight of the pretreatment
solution. The appropriate levels of bleed control agent can be
readily determined by one of ordinary skill in the art through
routine experimentation.
Surfactant
[0050] The surfactant can be any surfactant that lowers the surface
tension of the multivalent salt solution to about 15 to about 10
dynes/cm or preferably about 18 to about 30 dynes/cm. The amount of
surfactant is from about 0.05% to about 10% by weight, typically
from about 0.25 to about 8% by weight and more typically from 0.5
to 6% by weight based on the as received weight from the commercial
supplier. Typically the surfactant may contain some organic solvent
components and/or water.
[0051] Up to 5% by weight of organic solvents may be included in
the pretreatment solution especially those solvents that are part
of the available surfactant.
Textile
[0052] The textile to be pretreated can be any textile suitable for
printing with colored inkjet inks. Typically, the textile includes
natural material such as cotton and cotton blends, and synthetic
material such as polyester.
Pretreatment of Textile
[0053] Application of the pretreatment to the textile can be any
convenient method and such methods are generally well-known in the
art. One example is an application method referred to as padding.
In padding, a textile is dipped in the pretreatment solution, then
the saturated textile is passed through nip rollers that squeeze
out the excess solution. The amount of solution retained in the
textile can be regulated by the nip pressure applied by the
rollers. Other pretreatment techniques include spray application
wherein the solution is applied by spraying on the face or face and
back of the textile. Spraying can be limited to the digitally
printed area of the printed textile. An example of where this
limited spraying would be particularly applicable is in the digital
printing of an image on preformed textile articles such as, for
example, a T-shirts, caps, undergarments and like clothing
articles.
[0054] After application of pretreatment, the textile may be dried
in any convenient manner. The textile is preferably substantially
dry at the time of printing, such that the final percent moisture
is (approximately) equal to the equilibrium moisture of the
pretreated textile at ambient temperature. The absolute amount of
moisture in the textile, of course, can vary somewhat depending on
the relative humidity of the surrounding air.
Colored Inkjet Inks
[0055] The colorant used for printing the colored image may be a
dye or a pigment. Dyes include disperse dyes, reactive dyes, acid
dyes and the like. The colored inkjet inks are preferably aqueous
and do not contain components that are UV curable.
[0056] Pigmented inks are preferred. Pigmented inkjet inks suitable
for use in the present method typically comprise a pigment
dispersed in a vehicle. Typically, the vehicle is an aqueous
vehicle. More typically, the pigment ink comprises an anionically
stabilized pigment dispersed in an aqueous vehicle.
[0057] The selected pigment(s) may be used in dry or wet form. For
example, pigments are usually manufactured in aqueous media, and
the resulting pigments are obtained as a water-wet presscake. In
presscake form, the pigment does not agglomerate to the extent it
would in dry form. Thus, pigments in water-wet presscake form do
not require as much mixing energy to de-agglomerate in the premix
process as pigments in dry form. Representative commercial dry
pigments are listed in U.S. Pat. No. 5,085,698.
[0058] Some examples of pigments with coloristic properties useful
in inkjet inks include: cyan pigments from Pigment Blue 15:3 and
Pigment Blue 15:4; magenta pigments from Pigment Red 122 and
Pigment Red 202; yellow pigments from Pigment Yellow 14, Pigment
Yellow 95, Pigment Yellow 110, Pigment Yellow 114, Pigment Yellow
128 and Pigment Yellow 155; red pigments from Pigment Orange 5,
Pigment Orange 34, Pigment Orange 43, Pigment Orange 62, Pigment
Red 17, Pigment Red 49:2, Pigment Red 112, Pigment Red 149, Pigment
Red 177, Pigment Red 178, Pigment Red 188, Pigment Red 255 and
Pigment Red 264; green pigments from Pigment Green 1, Pigment Green
2, Pigment Green 7 and Pigment Green 36; blue pigments from Pigment
Blue 60, Pigment Violet 3, Pigment Violet 19, Pigment Violet 23,
Pigment Violet 32, Pigment Violet 36 and Pigment Violet 38; white
pigments such as TiO.sub.2 and ZnO; and black pigment carbon black.
The pigment names and abbreviations used herein are the "C.I."
designation for pigments established by Society of Dyers and
Colourists, Bradford, Yorkshire, UK and published in The Color
Index, Third Edition, 1971.
[0059] The range of useful particle size after dispersion is
typically from about 0.005 micrometers to about 15 micrometers.
Typically, the pigment particle size should range from about 0.005
micrometers to about 5 micrometers; and, specifically, from about
0.005 micrometers to about 1 micrometers. The average particle size
as measured by dynamic light scattering is less than about 500 nm,
typically less than about 300 nm.
[0060] The amount of pigment present in the ink is typically in the
range of from about 0.1% to about 25% by weight, and more typically
in the range of from about 0.5% to about 10% by weight, based on
the total weight of ink. If an inorganic pigment is selected, the
ink will tend to contain higher percentages by weight of pigment
than with comparable inks employing organic pigment, since
inorganic pigments generally have higher densities than organic
pigments.
Aqueous Vehicle
[0061] Selection of a suitable aqueous vehicle mixture depends on
requirements of the specific application, such as the desired
surface tension and viscosity, the selected colorant, drying time
of the ink, and the type of substrate onto which the ink will be
printed. Representative examples of water-soluble organic solvents
which may be utilized in the present disclosure are those that are
disclosed in U.S. Pat. No. 5,085,698.
[0062] If a mixture of water and a water-soluble solvent is used,
the aqueous vehicle typically will contain about 30% to about 95 of
water with the remaining balance (i.e., about 70% to about 5%)
being the water-soluble solvent. Compositions of the present
disclosure may contain about 60% to about 95% water, based on the
total weight of the aqueous vehicle.
[0063] The amount of aqueous vehicle in the ink is typically in the
range of about 70% to about 99.8%; specifically about 80% to about
99.8%, based on total weight of the ink.
[0064] The aqueous vehicle can be made to be fast penetrating
(rapid drying) by including surfactants or penetrating agents such
as glycol ether(s) or 1,2-alkanediols. Suitable surfactants include
ethoxylated acetylene diols (e.g., Surfynols.RTM. series from Air
Products), ethoxylated primary (e.g., Neodol.RTM. series from
Shell) and secondary (e.g., Tergitol.RTM. series from Union
Carbide) alcohols, sulfosuccinates (e.g., Aerosol.RTM. series from
Cytec), organosilicones (e.g., Silwet.RTM. series from Witco) and
fluoro surfactants (e.g., Zonyl.RTM. series from DuPont).
[0065] The amount of glycol ether(s) or 1,2-alkanediol(s) added
must be properly determined, but is typically in a range of from
about 1% to about 15% by weight, and more typically about 2% to
about 10% by weight, based on the total weight of the ink.
Surfactants may be used, typically in an amount of from about 0.01%
to about 5%, and specifically from about 0.2% to about 2%, based on
the total weight of the ink.
Polymeric Dispersant
[0066] The polymeric dispersant for the non-self-dispersing
pigment(s) may be a random or a structured polymer. Typically, the
polymer dispersant is a copolymer of hydrophobic and hydrophilic
monomers. The "random polymer" means polymers where molecules of
each monomer are randomly arranged in the polymer backbone. For a
reference on suitable random polymeric dispersants, see: U.S. Pat.
No. 4,597,794. The "structured polymer" means polymers having a
block, branched, graft or star structure. Examples of structured
polymers include AB or BAB block copolymers such as the ones
disclosed in U.S. Pat. No. 5,085,698; ABC block copolymers such as
the ones disclosed in EP Patent Specification No. 0556649; and
graft polymers such as the ones disclosed in U.S. Pat. No.
5,231,131. Other polymeric dispersants that can be used are
described, for example, in U.S. Pat. No. 6,117,921, U.S. Pat. No.
6,262,152, U.S. Pat. No. 6,306,994 and U.S. Pat. No. 6,433,117.
Polymeric Binders
[0067] Polymeric binders are polymers that improve the durability
of a pigment dispersion once it is deposited onto a surface. Unlike
a dispersant, binder usually do not have the functionality or
structure to adequately stabilize a pigment dispersion. Binders
often are added after a pigment dispersion has been made.
[0068] The binders can be soluble in the vehicle or in a dispersed
form, and can be ionic or nonionic. Soluble binders include linear
homopolymers and copolymers or block polymers. They also can be
structured polymers including graft or branched polymers, stars and
dendrimers. The dispersed polymers may include, for example,
latexes and hydrosols. The polymers may be made by any known
process including, but not limited to, free radical, group
transfer, ionic, condensation and other types of polymerization.
They may be made by a solution, emulsion, or suspension
polymerization process. Typical classes of polymeric binders
include anionic acrylic, styrene-acrylic and polyurethane
polymer.
[0069] A polymeric binder is typically present at a level between
about 0.01% and about 10% by weight, based on the total weight of
an ink. The upper limit is dictated by ink viscosity or other
physical limitations.
Cross-linking of Polymeric Binder
[0070] The polymeric binder can contain cross-linkable functional
moieties. Such polymeric binder is thus capable of reacting with a
cross-linking agent. Identified in the table below are suitable
cross-linkable functional groups that are in the polymeric binder
and the companion cross-linking groups that may be present in the
cross-linking agent.
TABLE-US-00001 Cross-linkable Moieties Cross-linking Groups COOH
Epoxide, Carbodiimide, Oxazoline, N-Methyol Hydroxyl Epoxide,
Silane, Isocyanate, N-Methyol Amino Epoxide, Carbodiimide,
Oxazoline, N-Methyol
[0071] The mole ratio of the cross-linkable moieties on the
polymeric dispersant to the cross-linking group(s) on the
cross-linking agent is from 15:1 to 1:1.5, typically from 9:1 to
1:1.1, and most typically from 8:1 to 1:1. In calculating the mole
ratio, all cross-linkable moieties on the polymeric dispersants and
all cross-linking groups on the cross-linking agent are
included.
[0072] Alternatively, cross-linkable functional moieties on a
polymeric binder can react with cross-linking groups present in a
textile resulting in cross-linking.
Other Additives
[0073] Other ingredients, additives, may be formulated into the
inkjet ink, to the extent that such other ingredients do not
interfere with the stability and jettability of the inkjet ink.
This may be readily determined by routine experimentation by one
skilled in the art.
[0074] Surfactants are commonly added to inks to adjust surface
tension and wetting properties. Suitable surfactants include the
ones disclosed in the Vehicle section above. Surfactants are
typically used in amounts up to about 5% and more typically in
amounts up to 2% by weight, based on the total weight of the
ink.
[0075] Inclusion of sequestering (or chelating) agents such as
ethylenediaminetetraacetic acid (EDTA), iminiodiacetic acid (IDA),
ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA),
nitrilotriacetic acid (NTA), dihydroxyethylglycine (DHEG),
trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA),
diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA), and
glycoletherdiamine-N,N,N',N'-tetraacetic acid (GEDTA), and salts
thereof, may be advantageous, for example, to eliminate deleterious
effects of heavy metal impurities.
Ink Sets
[0076] The term "ink set" refers to all the individual inks or
other fluids an inkjet printer is equipped to jet. Ink sets
typically comprise at least three differently colored inks. For
example, a cyan (C), magenta (M) and yellow (Y) ink forms a CMY ink
set. More typically, an ink set includes at least four differently
colored inks, for example, by adding a black (K) ink to the CMY ink
set to form a CMYK ink set. The magenta, yellow and cyan inks of
the ink set are typically aqueous inks, and may contain dyes,
pigments or combinations thereof as the colorant. Such other inks
are, in a general sense, well known to those of ordinary skill in
the art.
[0077] In addition to the typical CMYK inks, an ink set may further
comprise one or more "gamut-expanding" inks, including differently
colored inks such as an orange ink, a green ink, a red ink and/or a
blue ink, and combinations of full strength and light strength inks
such as light cyan and light magenta. Such other inks are, in a
general sense, known to one skilled in the art.
[0078] A typical ink set comprises a magenta, yellow, cyan and
black ink, wherein the black ink is an ink according to the present
disclosure comprising an aqueous vehicle and a self-dispersing
carbon black pigment. Specifically, the colorant in each of the
magenta, yellow and cyan inks is a dye.
Ink Properties
[0079] Jet velocity, separation length of the droplets, drop size
and stream stability are greatly affected by the surface tension
and the viscosity of the ink. Pigmented ink jet inks typically have
a surface tension in the range of about 20 dyne/cm to about 70
dyne/cm at 25.degree. C. Viscosity can be as high as 30 cP at
25.degree. C., but is typically somewhat lower. The ink has
physical properties compatible with a wide range of ejecting
conditions, i.e., driving frequency of the piezo element or
ejection conditions for a thermal head for either a drop-on-demand
device or a continuous device, and the shape and size of the
nozzle. The inks should have excellent storage stability for long
periods so as not to clog to a significant extent in an ink jet
apparatus. Furthermore, the ink should not corrode parts of the ink
jet printing device it comes in contact with, and it should be
essentially odorless and non-toxic.
[0080] Although not restricted to any particular viscosity range or
printhead, the inventive ink set is particularly suited to lower
viscosity applications such as those required by thermal
printheads. Thus the viscosity of the inventive inks at 25.degree.
C. can be less than about 7 cP, typically less than about 5 cP, and
more typically than about 3.5 cP. Thermal inkjet actuators rely on
instantaneous heating/bubble formation to eject ink drops and this
mechanism of drop formation generally requires inks of lower
viscosity.
Printing Method
[0081] The present method relates to digitally printing a
pretreated textile, where the pretreated textile may have been
dried. Typically, this involves the following steps: [0082] (1)
providing an inkjet printer that is responsive to digital data
signals; [0083] (2) loading the printer with a textile to be
printed, in this case the pretreated textile; [0084] (3) loading
the printer with the above-mentioned inks or inkjet ink sets; and
[0085] (4) printing onto the media using the inkjet ink or inkjet
ink set in response to the digital data signals.
[0086] After the printing the printed media may be heated to dry
the printed image. The heating conditions depend on the media and
its maximum temperature before melting, sagging or the like. A mild
heating condition can be about 70.degree. C. for about 15 minutes.
A simple oven may be used for this post printing step.
[0087] Printing can be accomplished by any inkjet printer equipped
for handling and printing on textile. Commercial printers include,
for example, the Dupont.TM. Artistri.TM. 3210 and 2020 printers
(Wilmington Del.), the Mimaki TX (Nagano, Japan) series of
printers, US Screen Printing T-Shirt Printer (Tempe, Ariz.) and a
DTG printer from Impression Technology (Sydney, Australia).
[0088] As indicated above, a variety of inks and ink sets are
available for use with these printers. Commercially available ink
sets include, for example, DuPont.TM. Artistri.TM. P3500 and P5000
series inks.
[0089] The amount of ink laid down on the textile can vary by
printer model, by print mode (resolution) within a given printer
and by the percent coverage need to achieve a given color. The
preferred amount of ink in each drop is less than about 35
picoliters, preferably less than about 25 picoliters, and more
preferably less than 15 picoliters. The amount of ink jetted that
can be jetted onto a media is dependent on the media and the
printer. For instance, for the DTG printer and transparencies a
drop size of less than 10 picoliters produces the best printed
image.
[0090] The following examples illustrate the invention without,
however, being limited Thereto.
EXAMPLES
Printing Conditions
[0091] The examples described below were done using DTG printers
Belquette Mod 1 and Flexijet. Printing was done with print
resolution set to 1440.times.720 dpi and 720.times.720 dpi. The
textiles substrate used were Gildan 50/50 polycotton blend shirts
and 100% Augusta polyester shirt.
Pretreatment Solutions
[0092] Reagent grade poly(acrylic) acid (Aldrich) was mixed with
deionized water until the poly(acrylic) acid was completely
dissolved in a solution. The surface tension was measured with a
Kruss tensiometer with a platinum plate at ambient temperature.
Evaluation of Color Characteristics
[0093] The L*, a*, b*, C* and h parameters of a CIE L*a*b* color
scale were measured for each printed textile with and without a
pretreatment using a X-Rite colorimeter, Model SP-64 from X-Rite
Inc. The total color difference, .DELTA.E* was then calculated.
Also measured was gamut volume of selected textile print set.
[0094] Various black and color inks from the DuPont.TM.
Artistri.TM. P5000+ series were used in the examples summarized in
Table 1 without further modification. Each test was carried out in
duplicate and the averaged result was tabulated. Printing was done
with print resolution set to 1440.times.720 dpi. As shown in Table
1 below, printing conducted on textiles, Gildan 50/50 polycotton,
treated with the pretreatment (PT) solution of the instant
disclosure showed significant total color differences when compared
to printing conducted on textiles without the pretreatment.
TABLE-US-00002 TABLE 1 Gildan 50/50 Color measurements Examples
polycotton L* a* b* C* h Delta E Ex. 1 P5000+ Black with 34.56 0.48
-1.03 1.14 294.91 7.23 PT Control Ex. 1 P5000+ Black w/o 27.39 0.97
-1.78 2.03 298.71 PT Ex. 2 P5000+ Cyan with 55.09 -10.62 -38.93
40.35 254.74 2.80 PT Control Ex. 2 P5000+ Cyan w/o 56.06 -9.19
-39.20 40.27 256.80 PT Ex. 3 P5000+ Magenta 83.61 -4.61 80.52 80.65
93.28 8.64 with PT Control Ex. 3 P5000+ Magenta 84.37 -3.14 88.87
88.93 92.04 w/o PT Ex. 4 P5000+ Yellow 51.89 54.86 -8.83 55.57
350.86 10.16 with PT Control Ex. 4 P5000+ Yellow 45.65 58.27 -1.58
58.30 358.45 w/o PT Ex. 5 P5000+ Process 52.77 42.97 -27.44 50.98
32.56 9.16 Red with PT Control Ex. 5 P5000+ Process 46.49 49.52
28.69 57.23 30.08 Red w/o PT Ex. 6 P5000+ Process 52.46 -38.22
22.59 44.39 149.41 3.69 Green with PT Control Ex. 6 P5000+ Process
50.88 -34.93 22.49 41.55 147.22 Green w/o PT Ex. 7 P5000+ Process
41.70 6.99 -36.42 37.08 280.87 11.20 Blue with PT Control Ex. 7
P5000+ Process 31.23 9.83 -33.58 34.99 286.31 Blue w/o PT
[0095] As shown in Table 2 below, similar results were obtained
printing on a different textile, 100% Augusta polyester.
TABLE-US-00003 TABLE 2 100% Augusta Color measurements no
pretreatment Examples Polyester L* a* b* C* H Delta E Ex. 8 P5000+
Black Poly with 32.59 0.87 0.97 1.30 47.89 6.00 PT Control Ex. 8
P5000+ Black Poly w/o 38.56 1.02 1.47 1.79 55.22 PT Ex. 9 P5000+
Cyan Poly with 47.78 -1.99 -43.76 43.80 267.40 9.68 PT Control Ex.
9 P5000+ Cyan Poly w/o 54.25 -5.94 -37.73 38.20 261.05 PT Ex. 10
P5000+ Magenta Poly 51.35 55.36 -7.29 55.84 352.50 6.07 with PT
Control Ex. P5000+ Magenta Poly 55.17 52.10 -10.69 53.18 348.40 10
w/o PT Ex. 11 P5000+ Yellow Poly 88.41 -7.90 81.02 81.41 95.57 6.47
with PT Control Ex. P5000+ Yellow Poly w/o 88.86 -8.65 74.61 75.11
96.61 11 PT Ex. 12 P5000+ Red Poly with 52.84 44.04 24.12 50.21
28.71 5.40 PT Control Ex. P5000+ Red Poly w/o 54.85 40.77 20.32
45.55 26.49 12 PT Ex. 13 P5000+ Green Poly with 48.28 -21.40 7.43
22.65 160.86 7.86 PT Control Ex. P5000+ Green Poly w/o 50.86 -28.08
10.67 30.04 159.19 13 PT Ex. 14 P5000+ Blue Poly with 40.36 10.08
-24.53 26.52 292.34 348 PT Control Ex. P5000+ Blue Poly w/o 41.61
12.33 -26.87 29.57 294.66 14 PT
* * * * *