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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a liquid composition for ink jet printing,
particularly a liquid composition suitable for printing of mixed woven
fabrics or mixed nonwoven fabrics comprising readily dyeable reactive
fibers such as cotton, hemp, viscose, wool, silk, nylon, etc, and less
dyeable nonreactive fibers such as polyester or acetate, and an ink jet
printing method by used thereof.
2. Description of the Prior Art
In the prior art, for printing of mixed woven fabrics comprising readily
dyeable reactive fibers such as cotton, hemp, viscose, wool, silk, nylon,
etc. and less dyeable nonreactive fibers such as polyester or acetate,
there have been employed printing methods such as roller printing, screen
printing, transfer printing, etc. in which a formulated dye of a reactive
dye (or a threne dye) and a disperse dye is used. Also, separately, the
printing method by ink jet system has been proposed. And, in practicing
the printing method by this ink jet system, considerable technical
difficulty has been accompanied in finely dispersing the formulated dye
uniformly into the liquid composition for printing. At the same time,
particularly the formation ratio of the dyes in the droplets discharged
from the ink jet nozzle cannot be kept constant, and therefore in the dye
fixing treatment after printing, there ensues frequently the problem that
variation in concentration occurred in dyeing to give non-uniform dyed
product without color regularity. Thus, this technique has not been easily
practiced.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a liquid
composition for printing which can be applied to the printing method
according to the ink jet system to realize a print of good quality.
Another object of the present invention is to provide an ink jet printing
method improved so as to give a uniform dyed product without color
irregularity.
The present invention accomplishing these objects provides, in one aspect,
a liquid composition for ink jet printing comprising a reactive disperse
dye dispersed or dissolved in an aqueous liquid medium and, in another
aspect, an ink jet printing method by imparting a liquid composition onto
a cloth according to the ink jet system and then subjecting the cloth to
dye fixing treatment, said liquid composition comprising a reactive
disperse dye dispersed or dissolved in an aqueous liquid medium.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
To describe in more detail about the present invention, the constitution
which charactersizes first the present invention is used of a reactive
disperse dye as the colorant of the liquid composition for ink jet
printing.
The reactive disperse dyes to be used in the present invention refer to a
slightly water-soluble azo type, anthraquinone type or other types of dyes
used sometimes in printing of, for example, polyester/cotton mixed woven
fabrics of the prior art. These reactive disperse dyes have molecular
weights within a certain limited range, and also have no water-soluble
group such as sulfonic acid group or carboxylic group in their structures,
and also have groups which can react with hydroxyl or amino groups of the
fibers to form covalent bonds with fibers, such as an ethyleneimine group,
an azide group, a sulfonethyleneimine group, a dichlorotriazine group, a
monochlorotriazine group, a trichloropyrimidine group, a
monochlorodifluoropyrimidine group, a chlorobenzothiazole group, a
dichloropyridazone group, a dichloropyridazine group, a
dichloroquinoxaline group, an epoxy group, a 3-carboxypyridiniotriazine
group, and the groups of
SO.sub.2 CH.sub.2 CH.sub.2 OSO.sub.3 H,
SO.sub.2 NHCH.sub.2 CH.sub.2 OSO.sub.3 H,
NHCOCH.sub.2 CH.sub.2 OSO.sub.3 H,
NHCOCH.sub.2 CH.sub.2 Cl,
NHCOCH.dbd.CH.sub.2,
SO.sub.2 CH.dbd.CH.sub.2,
CH.sub.2 NHCOCCl.dbd.CH.sub.2,
NHCOCBr.dbd.CH.sub.2,
NOCOCH.sub.2 Cl,
NHCH.sub.2 OH, -PO.sub.3 H,
SO.sub.2 CH.sub.2 CH.sub.2 OCOCH.sub.3,
SO.sub.2 CH.sub.2 CH.sub.2 OCOOC.sub.4 H.sub.9, etc.
Among them, examples of preferable reactive disperse dyes in the present
invention include those represented by the formulas shown below.
##STR1##
In the present invention, the above dyes and their derivatives can be
particularly preferably used.
In the present invention, the medium for dispersing the above reactive
disperse dye may preferably an aqueous liquid medium. Such an aqueous
medium may preferably be water alone or a mixture of water with a
water-soluble organic colvent. Examples of water-soluble organic solvent
include alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol,
ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol,
sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and the like;
amides such as dimethylformamide, dimethylacetamide and the like; ketones
or ketoalcohols such as acetone, diacetone alcohol and the like; ethers
such as tetrahydrofuran, dioxane and the like; polyalkylene glycols such
as polyethylene glycol, polypropylene glycol and the like; alkylene
glycols of which alkylene group contains 2 to 6 carbon atoms such as
ethylene glycol, propylene glycol, butylene glycol, triethylene glycol,
1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and
the like, glycerin; lower alkyl ethers of polyhydric alcohols such as
ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or
ethyl) ether, triethylene glycol monomethyl (or ethyl) ether and the like;
N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and so on.
In the present invention, the most preferable liquid medium composition
comprises water and at least one of water-soluble organic solvents, said
water-soluble solvent containing at least water-soluble high boiling
organic solvent, for example, polyhydric alcohols such as ethylene glycol,
propylene glycol, glycerin, etc. The amount of these liquid media employed
may be such that the ratio of the above reactive disperse dye contained
should be about 0.1 to 15% by weight when the liquid composition for
printing is prepared.
The liquid composition of the present invention contains the essential
components as described above and, otherwise it can contain various known
dispersing agents, surfactants, viscosity controllers added therein, if
necessary.
Important as the dispersing agents or surfactants which may be optionally
added are anionic dispersing agents or surfactants such as fatty acid
salts, alkylsulfate salts, alkylbenzenesulfonate salts,
alkylnaphthalenesulfonate salts, dialkylsulfosuccinate salts,
alkylphosphate salts, naphthalenesulfonic acid formalin condensates,
polyoxyethylenealkylsulfate salts, etc.; nonionic dispersing agents or
surfactants such as polyoxyethylene alkyo ether, polyoxyethylene
alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid
ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene
alkylamine, glycerin fatty acid ester, oxyethylene-oxypropylene block
copolymer, etc.
The viscosity controlling agent may preferably be primarily a water-soluble
natural or synthetic polymer such as carboxymethyl cellulose, sodium
polyacrylate, polyvinylpyrrolidone, gum arabic, starch, etc., and the
viscosity of the liquid composition of the present invention is controlled
to 50 cps or less, preferably 1 to 15 cps, at 25.degree. C. with the use
of or without use of these viscosity controlling agents.
In order to make up an ink to be used for the ink jet recording method in
which ink is electrically charged, a specific resistance controlling agent
composed of an inorganic salt is added such as lithium chloride, ammonium
chloride, sodium chloride, etc.
When the liquid composition is to be applied for the ink jet system in
which ink is discharged by the action of heat energy, thermal properties
(e.g. specific heat, thermal expansion coefficient, thermal conductivity,
etc.) may be sometimes controlled.
Further, other than the above three kinds of additives, it is also possible
to add, for example, defoaming agents, penetration agents, antifungal
agents, pH controllers, etc., if desired.
The liquid composition for ink jet printing of the present invention is
generally obtained by mixing the essential components and the optical
components as described above by a grinding means known in the art such as
ball mill, sand mill, speed line mill, etc. to make the particle size of
the dye generally to 30.mu.m or less, preferably 20.mu.m or less. If the
particle size is too large, there may be caused the problems such as
clogging of the ink jet nozzle, or incomplete level dyeing in the
subsequent dye fixing treatment step. Also, when a liquid medium capable
of dissolving the reactive disperse dye is selected as the liquid medium,
the liquid composition of the present invention can be obtained by mere
dissolving action such as heating, etc.
The liquid composition for printing of the present invention can be
basically obtained as described above, but a further important point in
the present invention is to control the liquid composition obtained by
formulating the essential components and the optical components as
described above to have a surface tension within the range from 35 to 60
dyne/cm. Control of the liquid composition to have such a surface tension
can be accomplished by those skilled in the art with ease by selection of
the reactive disperse dye, selection of the liquid medium and combination
thereof and use of various additives.
In the liquid composition of the present invention, if its surface tension
is less than 35 dyne/cm, the liquid composition applied to a woven or
nonwoven fabric comprising various kinds of fibers will spread to cause
excessive blurring of the liquid composition attached on its surface,
whereby fine picture patterns can be formed with difficulty. On the other
hand, if the surface tension exceeds the upper limit of the above range,
stable and uniform droplets can be obtained with difficulty during
discharging from the ink jet nozzle.
The value of the surface tension as mentioned above is measured by means of
VISCONIC ELD (produced by Tokyo Keiki Co.) at 25.degree. C.
In the present invention, it is very effective to adjust the content of
polyvalent metals in the liquid composition to not higher than 100 ppm.
Such adjustment of polyvalent metal content can be accomplished by
selection of the construction material of the apparatus for grinding the
reactive disperse dye to be used in the present invention, by purification
of the reactive disperse according to the known method or by use of
distilled water or deionized water as the liquid medium.
The construction material of the grinding apparatus may preferably to
alumina. The purification method may preferably the method in which the
dye is extracted with an organic solvent or the method in which the dye is
washed by suspending in a solvent in which polyvalent metals are soluble.
In the liquid composition of the present invention, if the content of
polyvalent metals is higher than 100 ppm, clogging of the ink jet nozzle
will frequently occur. Also, problems may also occur such as inferior
discharging stability from the nozzle or dispersion stability of the dye,
and further level dyeing on a cloth may become insufficient.
Further, it is also desirable to adjust pH to 3 to 7 in the liquid
composition of the present invention.
Such adjustment of pH can be accomplished with ease by adding suitably a pH
controller into the liquid composition. Basic controllers may preferably
be NaOH, KOH, Na.sub.2 CO.sub.3,K.sub.2 CO.sub.3, triethanolamine, etc.,
while acidic controllers may preferably be acetic acid, hydrochloric acid,
glycolic acid, etc.
In the liquid composition of the present invention, if its pH is lower than
3, there may sometimes occur corrosion or deterioration of the ink
pathways, and also dispersion stability of the dye may be lowered.
Further, if the pH is in the alkali region, the reaction may sometimes
occur between the constituent material of the liquid composition and the
dye, whereby the reaction with the cloth may be hindered.
The liquid composition as described in detail above is well fitted for the
ink jet system and is also useful for printing woven fabrics or nonwoven
fabrics, particularly mixed woven fabrics or mixed nonwoven fabrics
comprising reactive fibers dyeable with reactive dyes such as cotton,
hemp, viscose, wool, silk, nylon, etc. and non-reactive fibers dyeable
with disperese dyes such as polyester fiber, acetate fiber, polypropylene
fiber, vinylon fiber, etc. Although any of known woven fabrics or nonwoven
fabrics can be used, in addition thereto, these woven fabrics or nonwoven
fabrics applied with pretreatment for ink jet printing may also be
available. Such pretreatment can be performed by imparting a water-soluble
or water-dispersible polymer which can absorb or retain rapidly the liquid
composition for printing imparted onto the surface of the fiber
constituting the fabric.
The ink jet system employed for imparting the liquid composition of the
present invention to the woven fabric, nonwoven fabric or molded product
as described above may be any system, provided that it can release the
liquid composition of the present invention effectively from the nozzle
and impart it to the woven fabric or nonwoven fabric which is the target
to be jetted against. Typical examples of such systems are described in,
for example, IEEE Transactions on Industry Applications Vol. JA-13, No. 1
(Feb., March 1977); Nikkei Electronics No. 305 (Dec. 6, 1982). The systems
described in these literatures can be preferably used for the liquid
composition of the present invention. To describe about some of them,
there is first an electrostatic attracting system. In this system, a
strong electrical field is applied between a nozzle and an acceleration
electrode placed several mm ahead of the nozzle, and the ink formed into
particles from the nozzle is successively withdrawn and permitted to fly
between deflecting electrodes, while giving information signals to the
deflecting electrodes to effect recording; alternatively in another
system, ink particles are jetted out corresponding to the information
signals without deflection of ink particles. Either system may be
applicable for the present invention.
In the second system, high pressure is applied by a midget pump on ink and
the nozzle is vibrated mechanically by a quartz oscillator, etc., thereby
jetting out forcibly minute ink particles, and the ink particles jetted
out are electrically charged corresponding to information signals
simultaneously with jetting. The charged ink particles are deflected
corresponding to the amount of charges during passing through the
deflecting electrode plates. Another system utilizing this system is the
so called microdot ink jet system. According to this system, the ink
pressure and excitation conditions are maintained at appropriate values
within a certain limited range, two kinds of large and small droplets are
generated from the tip of the nozzle, of which only the small droplets are
utilized for recording. The specific feature of this system resides in
enabling to obtain of a group of minute droplets even with a large nozzle
opening of the prior art.
The third system is the piezoelectric device system. According to this
system, as a means for pressurizing ink, instead of mechanical means
employed in other systems, a piezoelectric device is used. By generating
mechanical displacement by giving electrical signals to a piezoelectric
device, pressure is applied to ink to jet it out of a nozzle.
The liquid composition of the present invention is also suitable for
printing by an ink jet system according to the method disclosed in U.S.
Pat. No. 4,410,899 in which the ink receiving action of heat energy
undergoes abrupt change in volume accompanied with generation of bubbles,
and the ink is discharged by pressurizing action due to the change.
Any of various ink jet systems as described above can be used, and picture
patterns such as letter, figures, etc. with colored liquid composition are
formed on cloths such as woven or nonwoven fabrics by employment of any of
such systems. Since the colorant in the liquid composition of the present
invention is not a mixture of a disperse dye and a water-soluble dye, but
comprises a dye of a single component, the liquid composition of ink can
be maintained always constant to enable uniform printing.
Accordingly, even after the subsequent dye fixing treatment such as alkali
treatment or heating treatment, sharp and minute picture patterns can be
formed. In contrast, when the ink for ink jet printing of the prior art is
used, the problems in the apparatus as mentioned above were caused and
also minute picture patterns were difficult to be formed on cloths due to
inferior level dyeing characteristics.
As described above, by use of the liquid composition of the present
invention, the liquid composition can be attached on a cloth corresponding
exactly to the image signals. Since the reactive disperse dye in the
liquid composition in this state is merely attached onto the cloth, it is
preferably subjected to reactive fixation of the dye onto the fiber and
removal of unfixed dye. Such reactive fixing and removal of unreacted dye
can be performed according to a known method, for example, according to
the treatment such as the steaming method, the HT steaming method, the
thermofix method, the alkali pad steam method, the alkali blotch steam
method, the alkali shock method, the alkali cold fix method, etc.,
followed by washing.
According to the present invention as described above, an expensive
printing plate is not required as in general printing of the prior art,
but the image to be printed can be prepared and modified with extreme ease
by means of a computer, whereby it is possible to adapt the desired
pattern at any time for the changes in fashion without employing expensive
plates as in the prior art. Accordingly, it has the advantage of being
applicable not only for industrial printing process but also for printing
as a hobby in homes in general.
The present invention is described in more detail by referring to the
following Examples, where parts and % are based on weight. In these
Examples, the term ink has the same meaning as the liquid composition as
mentioned above.
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Example 1 (example of ink preparation)
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Dye of the above formula (2)
5 Parts
Anionic surfactant (dispersing agent)
(Demol N, produced by Kao Sekken K. K.)
4 Parts
Ethylene glycol 15 Parts
Diethylene glycol 13 Parts
Water 65 Parts
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After all of the above components were dispersed in a ball mill made of
alumina for about 36 hours, the mixture was adjusted to pH 4.7 with acetic
acid, and further dispersed in the ball mill made of alumina for 3 hours,
followed by removal of coarse particles with particles sizes of 10 .mu.m
or more through Fluoropore Filter FP-1000 (produced by Sumitomo Denko
K.K.), to provide an aqueous ink (A).
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Example 2 (example of ink preparation)
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Dye of the above formula (7)
4 Parts
Anionic surfactant (Nikkol OTP-100s,
0.05 Parts
produced by Nikko Chemicals K. K.)
Anionic surfactant
(Demol N, produced by Kao Sekken K. K.)
1.5 Parts
Nonionic surfactant
(Emulgen 981, produced by Kao Sekken K. K.)
0.2 Parts
Isopropyl alcohol 0.5 Parts
Propylene glycol 15 Parts
Polyethylene glycol 400 5 Parts
Water 75 Parts
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After all of the above components were dispersed in a ball mill made of
alumina for about 40 hours, the mixture was adjusted to pH 5.6 with acetic
acid, and further dispersed in the ball mill made of alumina for 2 hours,
followed by removal of coarse particles with particles sizes of 5 .mu.m or
more through Fluoropore Filter EP-500 (produced by Sumitomo Denko K.K.),
to provide an aqueous ink (B).
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Example 3 (example of ink preparation)
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Dye of the above formula (14)
7 Parts
Dye of the above formula (15)
2 Parts
Nonionic surfactant
(Emulgen 707, produced by Kao Sekken K. K.)
1.5 Parts
Nonionic surfactant (Leodol TW-P120, produced
2.0 Parts
by Kao Sekken K. K.)
Ethylcarbitol 20 Parts
Water 70 Parts
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From all of the above components, an aqueous ink (C) was obtained in the
same manner as Example 2.
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Example 4 (example of ink preparation)
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Dye of the above formula (9)
6 Parts
Anionic surfactant (Ionet D-2, produced by
5.5 Parts
Sanyo Kasei Kogyo K. K.)
Ethylene glycol 25 Parts
Glycerin 5 Parts
1,3-Dimethylimidazolidinone
5 Parts
Water 60 Parts
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From all of the above components, an aqueous ink (D) was obtained in the
same manner as Example 1. Comparative example 1 (example of ink
preparation)
In place of the reactive disperse dye in Example 1, 3 parts of C.I.
Disperse Blue 3 and 2 parts of Reactive Blue 49 were employed, following
otherwise the same procedure as Example 1, to obtain an ink (E) for
comparative purpose.
COMPARATIVE EXAMPLE 2 (EXAMPLE OF INK PREPARATION)
In place of the reactive disperse dye in Example 2, 2 parts of C.I.
Disperse Red 54 and 2 parts of Reactive Red 22 were employed, following
otherwise the same procedure as Example 2, to obtain an ink (F) for
comparative purpose.
The properties of the ink obtained in Examples 1 to 4 and Comparative
examples 1 and 2 are shown in Table 1 shown below.
TABLE 1
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Comparative
Example example
Ink Ink Ink Ink Ink Ink
(A) (B) (C) (D) (E) (F)
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Surface tension
45 37 42 57 25 62
(dyne/cm)
pH 4.7 5.6 5.6 4.7 2.5 11.2
Polyvalent 78 53 60 18 80 62
metal content
(ppm)*1
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*1 Results of analysis by ICP (Induction Combined Emission
Spectroanalyzer) are shown.
EXAMPLE 5
The respective aqueous inks (A-F) of Examples 1 to 4 and Comparative
examples 1 and 2 were applied for an ink jet printer utilizing heat energy
according to the method as disclosed in U.S. Pat. No. 4,410,899 for
printing of various mixed woven fabrics, followed by heat treatment at
180.degree. C. for 90 second. Further, in an alkali bath prepared with
sodium carbonate and potassium chloride, dyeing was performed at
90.degree. C. for 20 seconds, followed by washing with a neutral
detergent, to obtain printed products. The results are shown in Tale 2.
TABLE 2
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Variance
Cloth Blurr
in dot size
__________________________________________________________________________
Example
Ink (A) Cotton 100% (georgette)
O O
Ink (B) Polyester 65%, Cotton 35% (broad)
O O
Ink (C) Polyester 50%, Cotton 50% (broad)
O O
Ink (D) Wool 100% (Taffeta)
O O
Comparative example
Ink (E) Cotton 100% (georgette)
X X
Ink (F) Cotton 100% (georgette)
O X
__________________________________________________________________________
*1 Sharpness of fine line (width: about 1 mm) of printed product was
judged by visual observation. O: Good X: Bad
*2 Dots were printed in an array of 30 cm at 1 mm intervals and variance
of dots was judged by visual observation. O: Good X: Bad
EXAMPLE 6
The respective aqueous inks (A-E) of Examples 1 to 4 and Comparative
example 1 were mounted on (1) an ink jet printer utilizing heat energy
according to the method disclosed in U.S. Pat. No. 4,410,899 (size of
nozzle : 40.times.50 .mu.) and (2) an ink jet printer PJ-1080A utilizing a
piezoelectric device (produced by Canon K.K., nozzle diameter 65 .mu.),
and continuous printing of 10 dots was performed by means of 10 nozzles on
a broad fabric comprising 65% polyester and 35% cotton. Also, the
respective aqueous inks (A-E) were placed in glass bottles of 100 cc and
stored therein at 40.degree. C. for one week for evaluation of storage
stability of ink. The results are shown in the Table 3 shown below.
The aqueous inks (A-D) of Examples 1 to 4 were mounted on an ink jet
printer PJ-1080A utilizing a piezoelectric device (produced by Canon K.K.,
nozzle diameter : 65 .mu.), and printing was effected on a broad fabric
comprising 65% polyester and 35% cotton, and thereafter heat treatment was
applied on the printed fabric at 180.degree. C. for 90 seconds, followed
by fixing by treatment in an alkali bath prepared with sodium carbonate at
90.degree. C. for 20 seconds. After washing with a neutral detergent and
drying, sharp printed products were obtained.
TABLE 3
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Comparative
Example example
Ink Ink Ink Ink Ink
(A) (B) (C) (D) (E)
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*1 Clogging Printer (1)
0 0 1 0 9
Printer (2) 0 0 0 0 9
*2 Storage stability X
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*1 Number of nozzles causing clogging when 10 dots were each continuously
printed by 10 nozzles in the printer of each system.
*2 After storage of ink at 40.degree. C. for one week, generation of
foreign matter was judged by visual observation. .circle. : No foreign
matter X : Foreign matter generated
* * * * *
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