U.S. patent application number 12/785164 was filed with the patent office on 2010-11-25 for pre-treatment liquid for liquid absorbing printing substrates.
This patent application is currently assigned to Vistaprint Technologies Limited. Invention is credited to Ulrich G. Hermann.
Application Number | 20100293725 12/785164 |
Document ID | / |
Family ID | 41124077 |
Filed Date | 2010-11-25 |
United States Patent
Application |
20100293725 |
Kind Code |
A1 |
Hermann; Ulrich G. |
November 25, 2010 |
PRE-TREATMENT LIQUID FOR LIQUID ABSORBING PRINTING SUBSTRATES
Abstract
Liquids for the pre-treatment of liquid absorbing substrates, in
particular textiles or garments, in printing processes are
disclosed, said liquids being based on water and/or a low molecular
alcohol and including small amounts of an organic acid and/or other
reagents to increase dye fixation as well as at least one corrosion
inhibiting agent selected from a group containing quaternary
ammonium salts, derivates thereof and their corresponding
organically substituted amines, hydroxy substituted acetylenic
components and derivates thereof, carboxylic, dicarboxylic and
polycarboxylic acids, long-chain carboxylic, dicarboxylic and
polycarboxylic acids and separated fractions and derivates thereof,
sulfur containing heterocyclic compounds and derivates thereof,
nitrogen containing heterocyclic compounds and derivates thereof,
nitrite and nitrate salts of metal ions, organic nitrites and
nitrates, organic nitrogen compounds and reductive nitrogen
containing compounds. Preferably the concentration of the corrosion
inhibiting agent is between 0.01 wt. % and 10 wt. % and the surface
tension of the liquid between 15 mN/m and 70 mN/m.
Inventors: |
Hermann; Ulrich G.; (Uster,
CH) |
Correspondence
Address: |
WILMERHALE/BOSTON
60 STATE STREET
BOSTON
MA
02109
US
|
Assignee: |
Vistaprint Technologies
Limited
Hamilton
BM
|
Family ID: |
41124077 |
Appl. No.: |
12/785164 |
Filed: |
May 21, 2010 |
Current U.S.
Class: |
8/480 |
Current CPC
Class: |
D06P 1/66 20130101; D06P
5/30 20130101; D06P 5/001 20130101; D06P 5/22 20130101; D06P 1/6426
20130101; C09D 11/54 20130101 |
Class at
Publication: |
8/480 |
International
Class: |
D06P 5/22 20060101
D06P005/22 |
Foreign Application Data
Date |
Code |
Application Number |
May 25, 2009 |
EP |
09161020.4 |
Claims
1. Liquid for the pre-treatment of liquid absorbing substrates, in
particular textiles or garments, in printing processes, said liquid
being based on water and/or a low molecular alcohol and including
small amounts of an organic acid and/or other reagents to increase
dye fixation, characterized in that said liquid contains at least
one corrosion inhibiting agent.
2. Liquid according to claim 1, wherein the corrosion inhibiting
agent is selected from a group containing quaternary ammonium
salts, derivates thereof and their corresponding organically
substituted amines, hydroxy substituted acetylenic components and
derivates thereof, carboxylic, dicarboxylic and polycarboxylic
acids, long-chain carboxylic, dicarboxylic and polycarboxylic acids
and separated fractions and derivates thereof, sulfur containing
heterocyclic compounds and derivates thereof, nitrogen containing
heterocyclic compounds and derivates thereof, nitrite and nitrate
salts of metal ions, organic nitrites and nitrates, organic
nitrogen compounds, reductive nitrogen containing compounds,
combinations and solutions thereof and the like.
3. Liquid according to claim 2, wherein the corrosion inhibiting
agent is soluble in protic solvents.
4. Liquid according to claim 3, wherein the viscosity of the
corrosion inhibiting agent or its solution is adjusted to be lower
than 1500 mPas at 25.degree. C., by mixing with water or alcohol at
percentages of 0.01 wt. % to 25 wt. %.
5. The method of claim 4, wherein the water or alcohol is a
percentages of 0.1 wt. % to 3 wt. %.
6. The method of claim 4, wherein the viscosity of the corrosion
inhibiting agent or its solution is adjusted to be lower than 500
mPas at 25.degree. C.
7. The method of claim 4, wherein the viscosity of the corrosion
inhibiting agent or its solution is adjusted to be lower than 200
mPas at 25.degree. C.
8. Liquid of claim 1, wherein the concentration of the corrosion
inhibiting agent or its solution is between 0.01 wt. % and 10 wt.
%.
9. Liquid of claim 1, wherein the concentration of the corrosion
inhibiting agent or its solution is between 0.05 wt. % and 5 wt.
%.
10. Liquid of claim 1, wherein the concentration of the corrosion
inhibiting agent or its solution is between 0.1 wt. % and 1 wt.
%.
11. Liquid of claim 1, wherein the surface tension of the liquid is
between 15 mN/m and 70 mN/m.
12. Liquid of claim 1, wherein the surface tension of the liquid is
between 17 mN/m and 50 mN/m.
13. Liquid of claim 1, wherein the surface tension of the liquid is
between 20 mN/m and 40 mN/m.
14. Liquid according to claim 1, wherein the surface tension of the
liquid is adjusted by addition of at least one surface-active
agent.
15. A method of using the liquid of claim 1, comprising applying
the liquid to a substrate in a printing process.
16. The method of claim 15, wherein the printing process is a
wet-in-wet ink jet printing process.
17. The method of claim 15, wherein the printing process is a
direct-to-garment printing process.
18. The method of claim 16, wherein the liquid is used as a priming
fluid.
19. The method of claim 16, wherein the liquid is applied to the
printing substrate directly before the printing and preferably
applied by spraying or rolling of the liquid onto the printing.
20. The method of claim 16, wherein the application of the liquid
to the printing substrate is done inside the printing machine.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn.119(a)-(c) to European Patent Application No.
09161020.4, filed May 25, 2009.
BACKGROUND
[0002] The present invention refers to pre-treatment liquids for
liquid absorbing printing substrates. In particular, the present
invention refers to pre-treatment liquids for use in
direct-to-garment printing processes.
[0003] Applying liquid ink on liquid absorbing substrates is a
well-known technique to print patterns, fonts or pictures with high
definition on such substrates. Printable liquid absorbing
substrates are, for example, paper, cardboard, woven or non-woven
materials, lengths of material, textiles, garments and the like. A
known printing process, which employs liquid ink is, for example
ink jet printing. Ink jet printing is widely performed in two
different ways: (1) by continuous ejection of pressurized ink
through nozzles, or (2) by applying ink droplet-by-droplet only in
places where such ink droplets are required to form a printed
image. The latter is generally done using the so called
drop-on-demand technique, where ink droplets are ejected from a
print head at high speed, for example, using piezoelectric crystals
that propel the ink droplets.
[0004] The problems when using ink jet printing techniques to print
on absorbing materials such as textiles or garments, for example,
by direct-to-garment printing, are diverse. For example, the
applied inks often suffer in terms of color fidelity, color
vividness and color strength. Also, wash resistance of the printed
image is often an issue. Moreover, in particular in high definition
printing applications, bleeding is a major issue, that is, the
intrusion of one ink spot into adjacent ink spots. In the large
picture, this results in improper contrast and blurred
representation of the printed image. Bleeding is affected by
numerous factors, including the substrate's ink absorption and
capillary action characteristics, the ink's properties, such as,
for example, the drying speed as well as the printing technology
and in particular the ink jet printer's nozzle arrangement that is
being used for applying the ink.
SUMMARY
[0005] To overcome these problems, various pre-treatment liquids
based on different chemical compositions have been developed for
use in direct-to-garment printing. Typically, pre-treatment liquids
are based on water or a low molecular alcohol and include small
amounts of an organic acid that serves to immobilize ink droplets
and increase dye fixation. Other than that, pre-treatment liquids
may contain sizing agents, anti-bleeding agents, pH controllers
(buffers), moisturizers, surfactants and specific conditioners,
such as, for example, anti-reducing agents.
[0006] In one aspect, a liquid for the pre-treatment of liquid
absorbing substrates, in particular textiles or garments, in
printing processes is provided, the liquid being based on water
and/or a low molecular alcohol and including small amounts of an
organic acid and/or other reagents to increase dye fixation,
characterized in that the liquid contains at least one corrosion
inhibiting agent.
[0007] In one or more embodiments, the corrosion inhibiting agent
is selected from a group containing quaternary ammonium salts,
derivates thereof and their corresponding organically substituted
amines, hydroxy substituted acetylenic components and derivates
thereof, carboxylic, dicarboxylic and polycarboxylic acids,
long-chain carboxylic, dicarboxylic and polycarboxylic acids and
separated fractions and derivates thereof, sulfur containing
heterocyclic compounds and derivates thereof, nitrogen containing
heterocyclic compounds and derivates thereof, nitrite and nitrate
salts of metal ions, organic nitrites and nitrates, organic
nitrogen compounds, reductive nitrogen containing compounds,
combinations and solutions thereof and the like.
[0008] In any of the preceding embodiments, the corrosion
inhibiting agent is soluble in protic solvents.
[0009] In any of the preceding embodiments, the viscosity of the
corrosion inhibiting agent or its solution is adjusted to be lower
than 1500 mPas at 25.degree. C., preferably lower than 1000 mPas at
25.degree. C., more preferably lower than 500 mPas at 25.degree. C.
and most more preferably lower than 200 mPas at 25.degree. C. by
mixing with water or alcohol at percentages of 0.01 wt. % to 25 wt.
%, and preferably 0.1 wt. % to 3 wt %.
[0010] In any of the preceding embodiments, the concentration of
the corrosion inhibiting agent or its solution is between 0.01 wt.
% and 10 wt. %, preferably between 0.05 wt. % and 5 wt. %, and more
preferably between 0.1 wt. % and 1 wt. %.
[0011] In any of the preceding embodiments, the surface tension of
the liquid is between 15 mN/m and 70 mN/m, preferably between 17
mN/m and 50 mN/m, and more preferably between 20 mN/m and 40
mN/m.
[0012] In any of the preceding embodiments, the surface tension of
the liquid is adjusted by addition of at least one surface-active
agent.
[0013] In another aspect, the liquid as described herein above is
used in a printing process.
[0014] In another embodiment, the printing process is a wet-in-wet
ink jet printing process.
[0015] In another embodiment, the printing process is a
direct-to-garment printing process.
[0016] In any of the preceding embodiments, the liquid is used as a
priming fluid.
[0017] In any of the preceding embodiments, the liquid is applied
to the printing substrate directly before the printing and
preferably applied by spraying or rolling of the liquid onto the
printing.
[0018] In any of the preceding embodiments, the application of the
liquid to the printing substrate is done inside the printing
machine.
DETAILED DESCRIPTION
[0019] The use of pre-treatment liquids prior to the application of
liquid ink on absorbing substrates by ink jet printing in a
wet-in-wet printing process improves print quality by immobilizing
ink droplets on the substrate surface or at least close thereto and
thereby avoiding bleeding, enhancing contrast, letting colors of
the applied inks appear stronger and more brilliant, etc. In
addition thereto garments treated by pre-treatment liquids in
direct-to-garment printing techniques enjoy improved tensile
strength, softer feel, improved or better controlled wash
resistance, etc.
[0020] Known pre-treatment liquids are, however, corrosive due to
the organic acids contained therein as well as ammonium salts
and/or halide ions that are often present in such liquids. It has
been found that known pre-treatment liquids lead to corrosion of
non corrosion-resistant parts in print facilities and, in
particular, in printing machines, by direct contact and notably
also indirect contact with these liquids. This generally leads to
increased service and maintenance costs and unwanted down times of
the printing machines and other print facility equipment.
[0021] It is therefore an object of the invention to provide
improved pre-treatment liquids that are less corrosive and possibly
even protective against corrosion while, at the same time,
maintaining the advantageous effects of known pre-treatment liquids
on the print quality and the printing substrates.
[0022] To solve this object the invention provides a liquid for the
pre-treatment of liquid absorbing substrates for use in printing
processes, said liquid being based on water and/or a low molecular
alcohol and including a small amount of an organic acid and/or
other reagents to increase dye fixation, and wherein said liquid
contains at least one corrosion inhibiting agent. Preferably, the
corrosion inhibiting agent is soluble in protic solvents.
[0023] Organic acids used in pre-treatment liquids are, for
example, monocarboxylic acids, such as, formic acid, acetic acid,
propionic acid, and the like as well as aromatic acids, such as,
benzoic acid and derivatives thereof, benzene sulfonic acid,
p-toluene sulfonic acid and derivatives thereof. Different organic
acids may also be used in pre-treatment liquids as long as they are
sufficiently well soluble in water. Other reagents to increase dye
fixation used in pre-treatment liquids are, for example, guanidine
and its slats, alumina and silica powders as well as tartaric acid
ammonium salts.
[0024] Also, pre-treatment liquids of the invention may contain
hydrotropic agents, such as, for example, urea and thiourea, sizing
agents, such as, for example, cellulose and derivatives thereof,
alginate, xanthane gum, shellac gum, gum arabic and the like as
well as conditioners, such as, for example, sodium chloride and
sodium sulphate salts.
[0025] In a preferred embodiment of the invention, the corrosion
inhibiting agent is selected from the group containing quaternary
ammonium salts, derivates thereof and their corresponding
organically substituted amines, hydroxy substituted acetylenic
components and derivates thereof, carboxylic, dicarboxylic and
polycarboxylic acids, long-chain carboxylic, dicarboxylic and
polycarboxylic acids and separated fractions and derivates thereof,
sulfur containing heterocyclic compounds and derivates thereof,
nitrogen containing heterocyclic compounds and derivates thereof,
nitrite and nitrate salts of metal ions, organic nitrites and
nitrates, organic nitrogen compounds, reductive nitrogen containing
compounds, combinations thereof and the like.
[0026] Other compounds, such as, for example, phosphonic acid
esters, may be used as corrosion inhibiting agent as long as they
are soluble in water or organic solvents and do not produce skin
irritations or do other harm to the wearer.
[0027] In another preferred embodiment, the concentration of the
corrosion inhibiting agent is between 0.01 wt. % and 10 wt. %,
preferably between 0.05 wt. % and 5 wt. % and most preferably
between 0.1 wt. % and 1 wt. %.
[0028] In yet another preferred embodiment, the surface tension of
the pre-treatment liquid is between 15 mN/m and 70 mN/m, preferably
between 17 mN/m and 50 mN/m, and most preferably between 20 mN/m
and 40 mN/m. In order to adjust the surface tension of the
pre-treatment liquid of the invention to the desired range, a
surface-active agent may be added in an embodiment of the
invention.
[0029] The liquids for the pre-treatment of liquid absorbing
substrates for use in printing processes produce surprisingly good
results as regards the avoidance of bleeding, contrast and color
enhancements, wash resistance, etc. It turned out that this can be
attributed in parts to comparatively low concentrations of the
corrosion inhibiting agents in the pre-treatment liquids of the
invention, so that the ink droplet immobilizing effect and the dye
fixation effect of the organic acid and/or said other reagents to
increase dye fixation remain substantially unaffected. In addition,
the corrosion inhibiting agents do, in contrast to what was
expected by the inventors, only slightly affect the surface tension
of the pre-treatment liquids of the invention, in particular if
used at the low concentrations as mentioned, so that an effective
and quick moistening of the liquid absorbing substrates and in
particular textiles or garments can be achieved shortly before the
printing process.
[0030] Despite low concentrations of the corrosion inhibiting
agents in the pre-treatment liquids of the invention, they show
significantly reduced corrosive effects on printing machines and
print facility installations. In particular, pitting corrosion of
iron, steel, aluminium or magnesium containing parts is effectively
lowered. Moreover, again contrary to what was expected,
pre-treatment liquids of the invention did not produce any visible
marks, such as by discoloration, yellowing or browning on textiles
or garments during drying and/or oven baking, a process in which
printed textiles or garments are heated for curing and cross
linking purposes after being printed on.
[0031] The invention also refers to the use of the liquid for the
pre-treatment of liquid absorbing substrates in printing processes,
preferably a wet-in-wet ink jet printing process in which liquid
ink is printed directly on textiles or garments.
[0032] In accordance with a particularly preferred implementation,
the liquid for the pre-treatment of the liquid absorbing substrate
of the invention is used as a priming fluid, that is, the liquid is
applied to the liquid absorbing substrate directly before the
printing process. Preferably, the application of the pre-treatment
liquid of the invention includes spraying or rolling of the
pre-treatment liquid on the liquid absorbing substrate inside the
printing machine, that is, the ink jet printer. Alternatively or in
addition thereto, the pre-treatment liquid can be applied to the
liquid absorbing substrate outside the printing machine prior to
being processed therewith.
[0033] In such an implementation, the application of the
pretreatment liquid inside the printing machine can be achieved in
different ways. In one embodiment, for example, the entire print
substrate is moistened as the spray nozzle for spraying
pre-treatment liquid onto the liquid absorbing substrate is
arranged independently of the print head in the feeding area of the
printing machine. In such case, the amount of pre-treatment liquid
can be varied, for example, as different types of textiles or
garments are printed by altering the feeding speed of the printing
machine while having pre-treatment liquid fed to the spray nozzles
at constant rates.
[0034] In another embodiment, the spray nozzle is coupled to the
print head and thus pre-treatment liquid is applied to the
absorbing substrate mainly in areas, where also ink is going to be
applied. This way a reduced consumption of pre-treatment liquid can
be achieved and the amount of pre-treatment liquid can be varied
either by modifying the spray nozzle ejection rate or by changing
the relative speed of the print/spray head with regard to the
printing substrate.
[0035] Further features will become apparent when considering the
following detailed description of experimental results with
different pre-treatment-liquids according to the invention in test
systems.
Experimental Data
[0036] In order to work out optimized anti-corrosion and dye
fixation/ink droplet immobilization effects, a broad variety of
corrosion inhibitors were tested by the inventor in admixtures with
experimental pre-treatment liquids as may be used in
direct-to-garment printing processes.
[0037] Most experimental pre-treatment liquids were aqueous
solutions including 3 wt. % to 10 wt. % (preferably 5 wt. %) acetic
acid and 0.1 to 5 wt. % of low-molecular glycols or glycol ethers
(e.g. ethylene glycol or propyl glycol or ethylene glycol
monopropyl ether) slightly neutralized with small amounts (0.1 wt.
% to 3 wt. %, preferably 1 wt. % to 2 wt. %) of organic amines,
such as triethylamine, ethanolamine or higher homologues with
longer alkylic chains but still water-soluble. The surface tension
was in the range of 20 to 40 mN/m. Other experimental pre-treatment
liquids were alcoholic solutions.
[0038] The corrosion inhibiting agents tested in admixture with the
experimental pre-treatment liquids were of the following types:
[0039] Acetylenic alcohols (e.g. Korantin PP.TM., BASF),
dicarboxylic acids (e.g. Irgacor DSS G.TM., Ciba), polyvalent
acids, for example, polyacrylic acid (e.g. Mw: 1000;
Sigma-Aldrich), quarternary ammonium compounds (e.g. Lugalvan P.TM.
and Lugalvan BPC48.TM. BASF) and organically soluble heterocyclic
compounds, for example, imidazoline (e.g. Amin O.TM., Ciba),
sarcosine (e.g. Sarkosyl O.TM., Ciba) or triazole (e.g. Irgamet
42.TM., Ciba) derivatives.
[0040] For an improved mixing of the corrosion inhibiting agents in
the experimental pre-treatment liquids and subsequent spraying
thereof through nozzles, a relatively low viscosity of less than
500 mPas and preferably less than 200 mPas at 25.degree. C. of the
corrosion inhibiting agents, or their respective solutions, is
desirable and can be accomplished by suitably mixing with water or
isopropyl alcohol at percentages between 0.01 wt. % to 25 wt. %,
and preferably 0.1 wt. % to 3 wt %, that is, addition of 0.01 wt. %
to 25 wt. % and preferably 0.1 wt. % to 3 wt % of the corrosion
inhibiting agent to solvent water or alcohol, such as, for example
isopropyl alcohol or mixtures thereof.
[0041] In order to test corrosion inhibiting efficiency, non-plated
and untreated test bodies of non-corrosion resistant steel were
immersed in modified pre-treatment liquids. Corrosion of the test
bodies was evaluated on a daily basis.
[0042] Corrosions tests yielded the results given in table 1.
TABLE-US-00001 TABLE 1 Remarkable Concentr. Corrosion corrosion
(no. Corrosion inhibitor: (wt. %) after day 1 of days); specify 1.
none 0 strong 1, weight loss by corrosion 2. Korantin PP, BASF 0.1
to 1 none 28, very faint, no weight loss 3. Lugalvan P, BASF 0.1 to
1 none 21, very faint, no weight loss 4. Lugalvan BPC48, BASF 0.1
to 1 none 21 very faint, no weight loss 5. Irgacor DSS G, Ciba 0.1
minimum 14 very faint, no weight loss 6. Polyacrylic Acid 1 to 2
minimum 7 very faint, no (Sigma-Aldrich); 30% weight loss solution
in water 7. Irgamet 42, Ciba 0.1 to 1 none 28, non-aqueous solution
8. Amin O, Ciba 0.1 to 1 none 28, non-aqueous solution 9. Sarkosyl
O, Ciba 0.1 to 1 none 28, non-aqueous solution
[0043] Test bodies immersed in aqueous experimental pre-treatment
liquid without a corrosion inhibiting agent (No. 1 showed strong
corrosion already after one day). Test bodies immersed in
non-aqueous solutions but alcoholic solutions (Nos. 7 to 9) showed
no remarkable corrosion for a long time.
[0044] Following corrosion test, print tests were done with an ink
jet direct-to-garment printer in combination with suitable water
based inks in cyan, magenta, yellow, black and white color. Test
prints were done on dark and white T-shirts and the T-shirts oven
baked after printing at about 170.degree. C. for about 8
minutes.
[0045] Dark T-shirts were printed using aqueous pre-treatment
solutions according to the invention and white T-shirts were
printed using alcoholic pre-treatment solutions according to the
invention.
[0046] Printing with normal print parameters produced print results
that were absolutely comparable to direct-to-garment printing
processes using pre-treatment liquids according to the prior art.
No bleeding, no unsharp print result and no discoloration, such as
yellowing or brown discoloration were visible after printing and
oven baking. Wash tests revealed no deterioration of the print
result after five consecutive wash cycles.
* * * * *