U.S. patent application number 11/024900 was filed with the patent office on 2005-07-14 for ink set for ink jet printing.
This patent application is currently assigned to BROTHER KOGYO KABUSHIKI KAISHA. Invention is credited to Kawaguchi, Takashi, Mizuno, Akiko, Mori, Shiro, Sawada, Hidemasa.
Application Number | 20050150421 11/024900 |
Document ID | / |
Family ID | 34737290 |
Filed Date | 2005-07-14 |
United States Patent
Application |
20050150421 |
Kind Code |
A1 |
Sawada, Hidemasa ; et
al. |
July 14, 2005 |
Ink set for ink jet printing
Abstract
An ink jet ink set for fabric printing contains a magenta ink
containing C.I. Pigment Red 213 and a yellow ink containing a
yellow pigment having L*a*b* color system chromas a* and b* such
that -18.ltoreq.a*.ltoreq.0, and 50.ltoreq.b*.ltoreq.80 when
printed on fabrics by an ink jet method, whereby a vivid red can be
obtained in the printed portions of fabrics upon printing by an ink
jet method.
Inventors: |
Sawada, Hidemasa;
(Nagoya-shi, JP) ; Kawaguchi, Takashi;
(Nagoya-shi, JP) ; Mizuno, Akiko; (Nagoya-shi,
JP) ; Mori, Shiro; (Kawanishi-shi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
BROTHER KOGYO KABUSHIKI
KAISHA
Nagoya-shi
JP
FUJI PIGMENT CO., LTD
Kawanishi-shi
JP
|
Family ID: |
34737290 |
Appl. No.: |
11/024900 |
Filed: |
December 30, 2004 |
Current U.S.
Class: |
106/31.6 ;
427/258; 427/372.2 |
Current CPC
Class: |
D06P 5/30 20130101; C09D
11/40 20130101 |
Class at
Publication: |
106/031.6 ;
427/258; 427/372.2 |
International
Class: |
C09D 011/00; B05D
005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2004 |
JP |
2004-007007 |
Claims
1. An ink jet ink set for fabric printing comprising a magenta ink
containing C.I. Pigment Red 213 and a yellow ink containing a
yellow pigment having L*a*b* color system chromas a* and b* such
that -18.ltoreq.a*.ltoreq.0, and 50.ltoreq.b*.ltoreq.80 when
printed on fabrics by an ink jet method.
2. An ink jet ink set according to claim 1 wherein the yellow
pigment is selected from among C.I. Pigment Yellow 23, 74, 147,
150, 151, 154, 155, 175, 180 and 185.
3. An ink jet ink set according to claim 1 wherein each ink
contains an aqueous emulsion.
4. An ink jet printing method comprising the steps of forming red
on a fabric by attaching droplets of the inks of the ink set
according to claim 3 on the fabric; and fixing the coloring
material of the inks onto the fabric by thermal treatment of the
fabric.
5. An ink jet printing method according to claim 4, wherein the
amount of ink droplets attached onto the fabric ranges from 7 to 30
mg per square inch.
6. An ink jet printing method according to claim 5, wherein the
fabric is a sheeting fabric made of cotton, polyester, or blends
thereof.
7. An ink jet ink set according to claim 2 wherein each ink
contains an aqueous emulsion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ink set used for fabric
printing by an ink jet method, and to an ink jet method using this
ink set.
[0003] 2. Description of the Related Art
[0004] Ink sets with 3 or 4 colors, yellow inks, magenta inks, blue
inks and, as needed, black inks, are widely used conventionally in
cases where full color is formed by ink jet methods, where
water-soluble dyes for each color are used as coloring agents.
Pigment inks using pigments have been adopted as well in recent
years, in addition to water-soluble dyes, from the viewpoint of
weatherability and water resistance. Fabrics are also printed by
ink jet methods using pigment inks.
[0005] However, reproduction of vivid hues is more difficult using
pigment inks than using dye inks, and the range of hues that can be
rendered is narrower. Thus, active research is being conducted on
combinations of pigments as coloring agents that may allow
obtaining vivid hues in printed portions by ink jet printing using
pigment inks (Japanese Patent Application Laid-Open No. H10-25440
and Japanese Patent Application Laid-Open No. 2001-181987).
[0006] C.I. Pigment Red 122 is widely used as pigment magenta ink,
for instance in the pigment ink disclosed in Japanese Patent
Application Laid-Open No. H10-25440.
[0007] However, C.I. Pigment Red 122 has the drawbacks of being
expensive, difficult to disperse and possessing a weak coloring
power, etc., and especially in fabrics, the surface after printing
tends to appear white due to fabric fluff. Moreover, vivid reds
cannot be obtained either by attempting to render red using yellow
inks and magenta inks comprising this C.I. Pigment Red 122, since
the resulting red hue is close to magenta.
SUMMARY OF THE INVENTION
[0008] In light of the above, an object of the present invention is
to provide an ink set of pigment inks for fabric printing by an ink
jet method, that allows imparting vivid hues, especially a vivid
red, to the printed portion, and to provide an ink jet printing
method that allows imparting vivid hues to fabrics, especially
forming printed portions with vivid reds on the fabrics, by using a
specified ink set.
[0009] The inventors perfected the present invention upon
discovering that vivid reds could be rendered on fabric by using a
C.I. Pigment Red 213 as a magenta pigment, and using a greenish
yellow pigment exhibiting, on the fabric, values of chromas a*, b*
within a specified range.
[0010] Specifically, the present invention provides an ink jet ink
set for fabric printing comprising a magenta ink containing C.I.
Pigment Red 213 and a yellow ink containing a yellow pigment having
L*a*b* color system chromas a* and b* such that
-18.ltoreq.a*.ltoreq.0, and 50.ltoreq.b*.ltoreq.80 when printed on
fabrics by an ink jet method.
[0011] In particular, the present invention provides embodiments
wherein the yellow pigment of the yellow ink in this ink jet ink
set for fabric printing is selected from C.I. Pigment Yellow 23,
74, 147, 150, 151, 154, 155, 175, 180 and 185, and embodiments
wherein the inks contain aqueous emulsions.
[0012] Also, the present invention provides an ink jet printing
method comprising the steps of forming red on the fabric by
attaching droplets, onto the fabric in an arbitrary sequence, of
the each ink of the ink set for fabric ink jet printing containing
the aforementioned aqueous emulsions; and fixing the coloring
material of the ink onto the fabric by thermal treatment of the
fabric.
[0013] In the ink set according to the present invention, used are
a magenta ink containing C.I. Pigment Red 213 and a greenish yellow
ink containing a yellow pigment having L*a*b* color system chromas
a* and b* such that -18.ltoreq.a*.ltoreq.0, and
50.ltoreq.b*.ltoreq.80 when printed on fabrics by an ink jet
method.
[0014] Therefore, the ink jet printing method according to the
present invention using this ink set for ink jet printing allows
achieving vivid and natural red hues on the printed portions while
expanding the rendering range in the green region, in which visual
perception is high in humans.
[0015] Since C.I. Pigment Red 213 has a greater coloring power than
C.I. Pigment Red 122, using C.I. Pigment Red 213 as pigment in
magenta inks allows reducing to a fifth the amount of magenta
pigment that must be used to achieve the same color development as
when using C.I. Pigment Red 122.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an a*-b* graph showing the rendering range
expansion in the periphery of red by different magenta pigments.
FIG. 2 is an a*-b* graph showing the rendering range expansion of
the green area by different yellow pigments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The ink set of the present invention is explained in detail
as below.
[0018] The present invention comprises at least a yellow ink and a
magenta ink, and may additionally comprise as needed a cyan ink and
a black ink.
[0019] Herein C.I. Pigment Red 213 is used as the coloring agent of
the magenta ink. The use of C.I. Pigment Red 213 allows expanding
the rendering range of red in the portions printed by ink-jet, as
compared with the conventional C.I. Pigment Red 122 widely used as
a magenta ink pigment; thus, vivid reds can be rendered by
combining a magenta ink comprising C.I. Pigment Red 213 with a
yellow ink with pigments of a specified chroma, as described below.
Also, the amount of pigment used can be reduced since C.I. Pigment
Red 213 has a stronger coloring power than C.I. Pigment Red
122.
[0020] The average volume particle diameter of the C.I. Pigment Red
213 in the magenta ink is set preferably to 50 nm or more from the
viewpoint of pigment dispersion stability, color development,
weatherability of the pigment, etc., and it is also preferably set
to 200 nm or less from the viewpoint of vividness, pigment
dispersion stability, color separation, etc.
[0021] The amount of C.I. Pigment Red 213 in the magenta ink ranges
preferably from 0.1 to 10 wt % from the viewpoint of color density
reproducibility and in order to maintain a good dispersibility in
the ink, etc.
[0022] The pigments used in the yellow ink of the ink set according
to the present invention are greenish yellow pigments having L*a*b*
color system chromas a* and b* such that -18.ltoreq.a*.ltoreq.0,
and 50.ltoreq.b*.ltoreq.80, preferably -15.ltoreq.a*.ltoreq.-5, and
50.ltoreq.b*.ltoreq.70, when printed on fabrics by an ink jet
method. Yellow pigments having such chromas that may be used
include for instance C.I. Pigment Yellow 3, 4, 5, 7, 17, 23, 50,
51, 74, 81, 98, 105, 147, 150, 151, 154, 155, 175, 180, 185, etc.
These can be used singly or in combination as the yellow ink
pigment.
[0023] By combining a magenta ink comprising C.I. Pigment Red 213
with a yellow ink consisting of yellow pigments having the a* and
b* chromas above, it is possible to achieve the rendering of a
vivid red in printed portions on fabric. In addition, by combining
these yellow inks with ordinary cyan ink-jet inks containing
pigments (for instance C.I. Pigment Blue 15:3, 15:4, etc.), it is
possible to expand the rendering range in the green region in which
visual perception is high in humans. By contrast, using a reddish
yellow pigment with a* greater than 0 in combination with C.I.
Pigment Red 213 allows expanding the rendering region of yellow,
oranges and other hues around red, but this expansion of the red
peripheral areas is not meaningful in practice. Also, using such
reddish yellow pigments results in a narrowing of the green
rendering range, which is undesirable. From the viewpoint of hue
balance, there are no yellow pigments having b* over 80 that can be
used in practice, while values of b* smaller than 50 result in a
darkening of the color of the printed portion, which is equally
undesirable.
[0024] Preferred yellow pigments, from the viewpoint of color
development, photoresistance, thermal resistance, dispersibility,
dispersion stability, supply stability, absence of environmentally
hazardous chlorine in the pigment structure, etc. are for instance,
C.I. Pigment Yellow 23, 74, 147, 150, 151, 154, 155, 175, 180 and
185 among the above-listed yellow pigments.
[0025] In the present invention, the chroma a* and b* values that
determine the yellow pigment are the measured chroma a*, b* values
(light source D65) of a 100% cotton white sheeting fabric (Hanes
Beefy-T) printed by an ink jet method with 0.1 to 100 picoliters
per droplet.
[0026] The average volume particle diameter of the yellow ink
pigment is set preferably to 50 nm or more from the viewpoint of
pigment dispersion stability, color development, weatherability of
the pigment, etc., and it is also preferably set to 250 nm or less
from the viewpoint of vividness, pigment dispersion stability, and
color separation, etc.
[0027] The amount of pigment in the yellow ink ranges preferably
from 0.5 to 15 wt % from the viewpoint of color density
reproducibility and in order to maintain a good dispersibility in
the ink, etc.
[0028] Coloring agents that may be used in cyan inks and black inks
include conventional cyan pigments and black pigments, for instance
cyan pigments such as C.I. Pigment Blue 15:3, 15:4, etc., and black
pigments such as carbon black, etc.
[0029] The inks for the different colors that constitute the
ink-set according to the present invention contain also aqueous
emulsions and aqueous solvents, in addition to the pigments above
as coloring agents.
[0030] The aqueous emulsions used herein act as pigment
dispersants, or binders for fixing the pigments on the fabric, and
include aqueous resin emulsions used conventionally in ink-jet
inks. Resins constituting these resin emulsions include for
instance acrylic resin emulsions, styrene/maleic anhydride
copolymer resin emulsions, urethane resin emulsions, vinyl acetate
resin emulsions, vinyl acetate/acrylic acid copolymer resin
emulsions, vinyl acetate/ethylene copolymer resin emulsions,
etc.
[0031] The kind of the aqueous emulsion is not particularly
restricted and may include anionic, cationic, nonionic, emulsions,
etc. Micro-emulsions, gross emulsions, reactive emulsions,
crosslinking emulsions at normal temperatures, 2-layer emulsions
etc. may also be used.
[0032] The amount of aqueous emulsion in the ink ranges from 0.1 to
73 wt %, preferably from 1 to 30 wt %, from the viewpoint of resin
emulsion dispersibility in the ink, adjuvant power for color
density reproduction, buffering of interactions with other ink
components, etc. The average volume particle diameter of the resin
micro-particles that constitute the emulsion ranges herein from 10
nm to 100 nm, preferably from 10 to 50 nm.
[0033] Pure water, deionized water, water-soluble organic solvents,
etc. may be used as the aqueous solvent. Water-soluble organic
solvents include for instance C1-C4 alkyl alcohols, ketones or
ketoalcohols, ethers, polyalkylene glycols, alkylene glycols with
C2-C6 alkylene groups, glycerin, low alkyl ethers of polyhydric
alcohols, N-methyl-2-pyrrolidone, triethanolamine, etc.
[0034] The inks for each color constituting the ink set according
to the present invention may further contain additives such as
surfactants, pH regulators, antifoaming agents, preservatives,
etc.
[0035] The method for preparing the inks may involve, for instance,
dispersing the pigments, the aqueous emulsion, the aqueous solvent,
and the additives as needed using dispersing equipment such as a
sand mill, a ball mill, a roll mill, etc., and separating the
coarser particles by centrifugation in order to obtain the pigment
ink. Alternatively, the pigment may be added under stirring to an
aqueous solution of aqueous emulsion prepared beforehand, with
dispersion being-carried out next using dispersion equipment.
[0036] The ink jet printing method according to the present
invention is a fabric printing method by attaching droplets of the
ink of each color onto the fabric by an ink jet method, in an
arbitrary sequence, using the ink set according to the present
invention which comprises at least red ink and yellow ink; the ink
jet printing method comprising the steps of forming a printed
portion having red areas on the fabric and fixing the coloring
material of the ink onto the fabric by thermal treatment of the
fabric.
[0037] Ink-jet methods herein include for instance piezo-type
methods using piezo elements in the printer head, etc.
[0038] The total amount of ink for each color attached as droplets
onto the fabric by an ink jet method ranges preferably from 7 to 30
mg per square inch. This allows achieving a good color reproduction
and an adequate density.
[0039] The fabrics printed by an ink jet method are not
particularly restricted provided their raw fibers can be dyed by
pigments, and include for instance woven fabrics, knitted fabrics,
non-woven fabrics, etc. These may include for instance natural
fibers such as cotton, silk, hemp, wool, etc., synthetic fibers
such as polyamides, polyesters, acrylics, etc.; regenerated and
semi-synthetic fibers such as rayon, acetate, etc.; or blended
fibers thereof. Fabrics that may be printed using the method
according to the present invention include preferably fabrics
having the feel, water absorbance, price and availability of 100%
cotton white T-shirts.
[0040] Thermal treatment is carried out after forming the printed
portion on the fabric in order to fix the color on the fabric;
herein the heating may be applied using a heat roller, by hot air
blowing, by steam heating, etc.
[0041] After the thermal treatment, the excess pigment or resin
from the aqueous emulsion etc. may be washed off as needed.
EXAMPLES
[0042] The invention is explained in detail as below by way of the
following Examples.
[0043] (1) Preparation of the Pigment Ink
[0044] A disperser (sand grinder, Igarashi Machinery Co. Ltd.) was
filled (filling rate 50 vol %) with 1 mm diameter glass beads or
zirconium beads (1 mm diameter), next 10 wt % of C.I. Pigment Red
213 as the pigment, 35 wt % of glycerin as the aqueous solvent, and
the balance of pure water were charged in the disperser, then the
mixture was crushed for 3 to 4 hours. The product was centrifuged
(10000 rpm, 30 minutes) to remove the coarser particles. To this,
added was as the aqueous emulsion 4.0 wt % of a 10% aqueous
solution of acrylic resin emulsion adjusted to a pH of 8 to 10,
yielding a magenta ink (pigment concentration 10 wt %) with
dispersed pigment particles having a volume average diameter
ranging from 50 nm to 200 nm.
[0045] The same ink was prepared using the pigments listed in Table
1 to obtain three magenta inks, three yellow inks and one cyan
ink.
[0046] (2) Fabric Printing
[0047] With the magenta and yellow inks prepared in (1), magenta
and yellow solid print images were formed on 100% cotton T-shirts
(Hanes Beefy T) using a piezo-type inkjet printer having a 600 dpi
resolution, and then red solid print images were formed by jetting
equal amounts of magenta and yellow inks, in that order.
[0048] The surfaces of the obtained images were measured using a
spectrophotometer (CM-3700d, from Minolta Co. Ltd.) to determine
their a*, b* chromas in a L*a*b* color system.
[0049] Green and blue wet images were formed in a similar way using
respectively the yellow and cyan inks, and the magenta and cyan
inks prepared in (1), and their a*, b* chromas were determined.
[0050] The results are given in Table 1, FIG. 1 and FIG. 2.
1TABLE 1 No. Pigment a* b* 1 Magenta Pig. R. 213 55.090 -2.318 2
Pig. R. 122 48.056 -24.175 3 P.R. 170 55.038 12.224 4 Yellow P.Y.
74 -8.056 60.986 5 P.Y. 55 2.951 66.896 6 P.Y. 180 -8.943 56.830 7
Cyan P.B. 15:3 -7.482 -44.037 8 Red P.R. 213 + P.Y. 74 43.657
21.179 9 P.R. 213 + P.Y. 180 32.286 22.701 10 P.R. 122 + P.Y. 74
22.017 23.099 11 P.R. 122 + P.Y. 180 19.903 24.291 12 P.R. 170 +
P.Y. 74 44.478 30.398 13 P.R. 170 + P.Y. 180 47.077 29.896 14 P.R.
213 + P.Y. 55 49.691 30.925 15 Green P.Y. 55 + P.B. 15:3 -29.645
11.962 16 P.Y. 180 + P.B. 15:3 -33.658 4.482 17 Blue P.R. 213 +
P.B. 15:3 14.891 -29.963 18 P.R. 122 + P.B. 15:3 6.874 -41.074
[0051] Table 1 and FIG. 1 show that when C.I. Pigment Red 213 is
used as the magenta pigment, the rendering range of red is wider
than when C.I. Pigment Red 122 is used. This expanded rendering
range is illustrated in FIG. 1 as the coarse-dot shaded area A in
FIG. 1.
[0052] In this case, the blue rendering range becomes narrower by
the fine-dot shaded area B of FIG. 1; however, the expansion of the
red rendering range through the use of C.I. Pigment Red 213 has a
dramatic effect in enlarging the color development range. This
suggests that C.I. Pigment Red 213 is to be preferably used as a
magenta pigment.
[0053] When a so-called red color C.I. Pigment Red 170 is used as
the magenta pigment, the blue rendering range becomes even narrower
than when C.I. Pigment Red 213 is used. Therefore, using C.I.
Pigment 213 as a magenta pigment allows obtaining an ideal red that
need not sacrifice blue rendering range.
[0054] On the other hand, the results of table 1 and FIG. 2 show
that, compared with using the greenish yellow pigments C.I. Pigment
Yellow 74 or 180, when the reddish yellow pigment C.I. Pigment
Yellow 55 is used in combination with C.I. Pigment Red 213, the
rendering range around red expands (area C in FIG. 2), but when
combined with C.I. Pigment Blue 15:3, the green rendering range
becomes narrower (area D in FIG. 2). The rendering range of the
expanded red periphery corresponds herein to areas of orange and
yellow, colors that have little bearing on the rendering of red,
and are thus not relevant for color reproduction in practice.
[0055] Moreover, the human visual perception is higher for green
regions than for red regions. Therefore, it is preferable to use a
greenish yellow pigment as the yellow pigment in combination with
the C.I. Pigment Red 213 in order to ensure an expansion of the
green rendering range, rather than to further expand an already
sufficient red rendering range.
[0056] The ink set according to the present invention is useful for
fabric printing by inkjet methods, in particular for forming vivid
red images in the printed portions.
[0057] The entire disclosure of the specification, claims, summary
and drawings of Japanese Patent Application No. 2004-007007 filed
on Jan. 14, 2004 is hereby incorporated by reference.
* * * * *