CA1069255A - Ink composition for ink jet recording - Google Patents
Ink composition for ink jet recordingInfo
- Publication number
- CA1069255A CA1069255A CA267,069A CA267069A CA1069255A CA 1069255 A CA1069255 A CA 1069255A CA 267069 A CA267069 A CA 267069A CA 1069255 A CA1069255 A CA 1069255A
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- CA
- Canada
- Prior art keywords
- ink
- ink composition
- water
- composition
- soluble
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/52—Electrically conductive inks
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
- H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
- H01H33/66—Vacuum switches
- H01H33/664—Contacts; Arc-extinguishing means, e.g. arcing rings
- H01H33/6644—Contacts; Arc-extinguishing means, e.g. arcing rings having coil-like electrical connections between contact rod and the proper contact
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
- H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
- H01H33/66—Vacuum switches
- H01H33/664—Contacts; Arc-extinguishing means, e.g. arcing rings
- H01H33/6643—Contacts; Arc-extinguishing means, e.g. arcing rings having disc-shaped contacts subdivided in petal-like segments, e.g. by helical grooves
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Inks, Pencil-Leads, Or Crayons (AREA)
- Ink Jet Recording Methods And Recording Media Thereof (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An ink composition for ink jet recording consisting essentially of a water-soluble wetting agent, water, a water-soluble dye and an oxygen absorber.
An ink composition for ink jet recording consisting essentially of a water-soluble wetting agent, water, a water-soluble dye and an oxygen absorber.
Description
~9~55 The present invention relates to an improved ink com-position for ink jet recording, which is used for an ink jet re-cording apparatus for performing recording by jetting ink drops in response to electric signals to cause the ink to adhere onto a recording medium.
In order for an ink for ink jet recording to be jetted in drops stably at high speeds, the ink should have the follow-'ing properties at temperatures approximating room temperature:
(1) Viscosity : lower than 5 cps
In order for an ink for ink jet recording to be jetted in drops stably at high speeds, the ink should have the follow-'ing properties at temperatures approximating room temperature:
(1) Viscosity : lower than 5 cps
(2) Surface tension : 40 - 50 dyne/cm
(3) Amount of dissolved air: less than about 0.013 ml/ml Inks disclosed in the specifications of U.S. Patent No. 3,846,141 and British Patent No. 1,378,894 satisfy the re-quirements for the viscosity and surface tension among the above three requirements. ~amely, in an ink comprising water, a water-soluble wetting agent and a water-soluble dye, an ink comprising a water-soluble solvent in`addition to the foregoing basic com-ponents and an ink further comprising a minute amount of a sur-face active agent, it is possible to reduce the viscosity below 5 cps and adjust the surface tension to 40 - 50 dyne/cm. However, in conventional ink compositions for ink jet recording, no adjust- ~
ment of the amount of dissolved air is made. If the amount of dissolved air is too large, increase of the pressure for jetting cannot be precisely transferred through the ink, and therefore, it becomes difficult to perform recording precisely in response to electric signals.
The present invention relates to an ink composition for ink jet recording~which can be jetted stably in drops at a high ~ -speed.
More specifically, the present invention relates to an ink composition for ink jet recording which comprises a water- ~ -soluble wetting ag~ent (binder), water, a water-soluble dye and an ~ ~ ~
-1- ~ . :
oxygen absorber. More particularly the invention is concerned - with such an ink composition comprising 5 to 4~/0 by weight of the water-soluble wetting agent, 0.1 to l~/o by weight of the water-soluble dye and 0.5 to l~/o by weight of the oxygen absorber, and water' the ink composition having a viscosity lower than 5 cps, a surface tension of 40 to 50 dyne/cm and an amount of dissolved air less than 0.013 ml/ml at temperatures approximating room temperature.
In particular the dye is one which is not subject to colour change and does not form a precipitate in the presence of the oxygen ab~orber; and the oxygen absorber does not change the colour of the ink, does not generate nitrogen gas and does not form a precipitate.
The oxygen absorber is one which is soluble in the ink composltion and is thus suitably water-soluble.
The invention will now be described with reference to the accompanying drawings which show a preferred form thereof and wherein: ~
Fig. 1 is a diagram illustrating an embodiment of the ink jet recording apparatus for which the ink composition of the present invention is used;
Fig. 2 is a graph illustrating the relation between the amount of dissolved air in an ink and the standing time, which is observed when the ink from which dissolved air has been removed by a degasification treatment such as boiling is allowed l to stand in air ;~`
Fig. 3 is a graph illustrating an instance of the ;
relation between the amount of dissolved air in an ink and the threshold voltage of a recording head; and --,:' ~ . .
. . ~ ... . :
.. . .
gjgz55 Fig, 4 is a diagram illustrating an ink vessel com~ :
posed of a plastic film which is used for intercepting air from an ink.
Various apparatuses have been known for ink jet record-ing, and the ink composition of the present invention can be applied to these known apparatuses~ An instance of such ink jet recording apparatus will now be described by reference to Fig. 1.
Referring now to Fig. 1, a recording head 1 comprises a piezo-electric element 2, a vibrating plate 3 and an ink chamber 10. An ink 8 held in an ink vessel 7 is fed into the ink chamber 10 through an ink feed pipe 6 and the ink chamber 10 is filled with the ink 8. Reference numerals 4 and 5 represent a nozzle and an ink drop, respectively. The recording medium 9 is composed of pape~, cloth, wood or the like. :
In the recording apparatus having the above structure, when an electric signal 11 is applied between the piezo-electric element 2 and the vibrating plate 3, the piezo-electric element 2 ~ .
causes vibrations in response to the applied electric signal to : '`. ',', ,', .,:
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:.
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~ ' ,: ' '-'~ `' ' .'. ', ' .,,,~ ' ~ ', _ 2a -~9ZS5 increase the pressure in the ink 8 contained in the ink chamber 10. By this pressure increase, the ink 8 is jetted from the noz-zle 4 in the form of liquid drops 5, and the jetted ink drops 5 adhere onto the surface of the recording medi~m 9 to form thereon an image corresponding to the electric signal. This ink jet re-cording apparatus is detailed in the specifications of U.S. Pat-ent No. 3,747,120 and U.S. Patent No. 3,9~0,773.
In an ink jet recording apparatus of this type, for ex-ample, in order to record an original image having an A-4 size and a resolving degree of 6 lines per cm for 2 minutes, it is necessary for the recording head 1 to stably jet ink drops 5 in response to electric signals corresponding to image signals hav-ing a frequency lower than lO KHz. For attaining this feature, repeated increase of the pressure by vibrations of the piezo-elec-tric element 2 must be faithfully transferred through the ink 8.
When the ink used has a high viscosity, the resistance is enhanced on the wall surface of the ink chamber or the nozzle portion to cause pressure loss and hence, faithful transfer of the pressure is impossible. The influence of the surface tension of the ink on jetting of the ink is not serious, but too high a sur-face tension, of course, must be avoided. If the surface tension of the ink is too low, running of the ink takes place on the re- ;~
cording medium.
In the case where the amount of dissolved air in the ink is large, the higher the frequency of repetition of increase of the pressure, t:he more the ink comes to have properties as a compressible fluicl and the more the transfer of increase of the pressure is delayed.
As is seen from the foregoing illustration, when the viscosity of the ink is high or the amount of dissol~ed air is large, it is impossible to transfer the increase of the pressure faithfully and as a result, it is impossible to perform recording :~ .
~L~69255 faithfully in response to electric signals.
For the reasons set forth above, in order to jet ink drops stably at a high speed under the abovementioned recording conditions, an ink to be used for ink jet recording must satisfy the following requirements concerning physical properties at temp-eratures approximating room temperature:
(1) Viscosity : lower than 5 cps (2) Surface tension : 40 - 50 dyne/cm (3) Amount of dissolved air: less than about 0.013 ml/ml It is a primary object of the present invention to pro-vide an ink composition for ink jet recording, in which the fore-going requirements are sufficiently satisfied and especially in which the amount of dissolved air can be maintained at a very low level.
In general, the solubility of air in water is 0.0183 ml/ml as measured at 20C and one atmosphere, and it is known that this water solubility consists of a solubility of oxygen which is 0.0064 ml/ml and a solubility of nitrogen which is 0.0119 ml/ml.
We measured the solubility of air in an ink composition comprising water, a water-soluble wetting agent, a water-soluble dye and a water-soluble solvent and satisfying the foregoing re-quirements of the viscosity and surface tension, and as a result, .,.. ~.. : ~ ~ .
it was found that the solubility of air in such ink composition is substantially equal to the solubility in water. -As a result of our experiments, it was confirmed that -when in~ jet recording is carried out by using a recording head as shown in Fig. 1, if the amount of dissolved air is larger than 0.013 ml/ml, the response characteristic of the recording head is degraded.
When the driving voltage of the recording head exceeds 250 Vpp, air bubbles are readily sucked in the head from the noz-zle and jetting of the ink particles becomes unstable. As will be ; ~4~
- . . . .. - -. . . , .. ~ - . - ~ . . . , . . - -~69255 apparent from Fig. 3 illus~rating the influence of the amount of dissolved air in the ink on the minimum driving voltage (~hreshold) voltage) for jetting of the ink particles, as the amount of dis-solved air increases, in order to jet the ink particles, it is necessary to raise the driving voltage, and if the amount ol the dissolved air exceeds 0.013 ml/ml, the threshold voltage for jet-ting of the ink particles is higher than 250 Vpp and it becomes impossible to perform recording stably.
When an ink composition satisfying the foregoing require-ments for viscosity and surface tension was subjected to a degas-ification treatment such as boiling so that the requirement for the amount of dissolved air was satisfied and the degasified ink composition was allowed to stand in the ink jet recording apparatus shown in Fig. 1, it was found that the amount of dissolved air in the ink composition increased with the lapse of time as shown in Fig. 2 and the amount of dissolved air in the ink composition was as large as 0.013 ml/ml after the lapse of about 1 hour.
Some of us previously proposed an ink vessel as shown in Fig. 4 as means for eliminating the above disadvantage. Refer~
ring to Fig. 4, in this ink vessel, air is shut out from an ink 8 by a plastic film bag 12.
Resins having a low gas permeability, such as vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acryloni-trile copolymers, polyvinylidene chloride-coated nylon resins and polyvinylidene chloride-coated polyester resins, are preferably :
employed for formation of the plastic film bag 12. For example, when a vinylidene chloride-vinyl chloride copolymer (KREHALON
manufactured by Kureha Plastics Co., Ltd.), which is one of the materials having a lower gas permeability among those mentioned, was shaped into a film having a thickness of 40~ and the film was used as the film bag 12, the amount of dissolved air increased at a rate of about 0.002 ml/ml/day, and in the case of an ink com-_5_ , , ,:
~69Z~iS
position formed by removing an oxygen absorber from an ink com-position of Example 3 given hereinafter, the life o~ the ink com-position was prolonged by about 1 week.
However, no plastic material is capable of completely shutting out gases, and such prolon~ation of the ink life is of no significance from the practical viewpoint.
From the experimental results shown in Figure 2, we found that the critical lower value of the amount of air dissolved in an ink is substantially equal to the solubility o~ nitrogen of dissolved air in the ink and the influence of dissolved air can be substantially eliminated if dissolved oxygen is removed from dissolved air. It was also found that this can be accomplished by removing oxygen which is continually being dissolved in the ink.
This removal of dissolved oxygen, in general, may be :: :
accomplished by a physical method or chemical method. According ~`
to the former physical mèthod, oxygen is removed by boiling or pressure reduction, but it is difficult to perform the treatment continuously and maintain the intended effect for a long time ac-cording to this physical method. Therefore, we conducted research on a chemical method for removal of dissolved oxygen, and as a res- ;-. ~ - .: -ult, we found that dissolved oxygen can be effectively removed -~
, .. .
without any harmful influence on the quality of an ink by incorpor- ;
. . .
;` ation of a specific oxygen absorber. Based on this finding, we have now completed the present invention.
;~ In the present invention, a substance capable of chemi- ; -cally reacting with oxygen dissolved in an ink is used as an oxy- ~ ~
! : ` ~ ` :
~ gen absorber. As such substance, there can be mentioned various - .
- compounds, for example, metals such as iron chips, sulfites such as sodium sulfite, ammonium sulfite, potassium sulfite, sodium hydrogensulfite, potassium hydrogensulfite and ammonium hydrogen~
sulfite, polyhydric phenols such as pyrogallol, and other reduc-ing agents such as sodium trithionite and hydrazine~ However, in~
-:
: :
~ ~069255 order for these substances to be effectively used in the present invention, they must satisfy various requirements. For example, they must be easily soluble in an ink, they must not change the color of the ink, they must not generate nitrogen gas or the like by reaction with oxygen, and they must not form precipitates. In view of these requirements, sulfites such as sodium sulfite, am-monium sulfite, potassium sulfite, sodium hydrogensulfite, potas-sium hydrogensulfite and ammonium hydrogensulfite are most pre-ferred as oxygen absorbers. For example, when sodium sulfite is used as the oxygen absorber, it absorbs oxygen according to the following reaction: -2~a2S03 + 2 = 2~a2S4 (formula 1) When water, a polyhydric alcohol as a water-soluble wet-ting agent, a water-soluble dye and sodium sulfite are placed in an ink vessel of a vinylidene chloride-vinyl chloride copolymer as shown in Figure 4, the amount of air permeating the film vessel is 0.002 ml/ml/day and the portion accounted for oxygen is 0.0007 ml/ml/day. Accordingly, the amount of sodium sulfite in the ink composition necessary for absorbing the thus dissolved oxygen is 7.g x 10 6 g/ml/day. In order to maintain the amount of dissolved~
:~
oxygen in the ink composition at a level of 0.0007 ml/ml, sodium sulfite must be incorporated into the ink composition in an amount of about 0.5% by weight. In some ink compositions, this critical ~i . , concentration of sodium sulfite is higher than 0.5% by weight. In an ink composition containing sodium sulfite in an amount larger than the above critical value, the amount of oxygen dissolved in ~ ;~
the ink composition is maintained at a very low level and this ef-fect is manifested until all of sodium sulfite incorporated lS con~
sumed. For exampLe, if sodium sulfite is incorporated in an amount~
of 1% by weight, the life~of the ink is about 630 days. However, i~ the amount of sodium sulfite incorporated exceeds 10% by weighit~, .. ..
the ink is readily dried to cause clogging of the nozzle.
' ' ~; ' ; ~7~
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~)69255 The water-soluble we-tting agent that is used in the present invention includes polyhydric alcohols which are liquid at temperatures approximating room temperature, such as glycerin, ethylene glycol, polyethylene glycol, propylene glycol, methyl glucoside, trimethylolpropane, trimethylolethane, neopentyl glycol, sorbitol and mannitol, alkyl ethers of aliphatic polyhydric alco-hols, which are liquid at temperatures approximating room temp-erature, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, ethoxy glycol, monopropylene glycol methyl ether, dipropylene glycol methyl ether ;~ -and tripropylene glycol methyl ether, mono-acetates of alkyl ethers of aliphatic polyhydric alcohols, which are liquid at temperatures approximating room temperature, such as ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate and di-ethylene glycol monoethyl ether acetate, hydroxyalkyl formamides which have l to 4 carbon atoms in the alkyl group, and N-vinyl-2-pyrrolidone oligomers which are liquid at temperatures approximat- ~`
ing room temperature.
These water-soluble wetting agents may be used singly or in the form of mixtures of two or more of them.
The above-mentioned N-vinyl-2-pyrrolidone oligomers can be synthesized by adding concentrated sulfuric acid as a catalyst in an amount of 0.05 to 5% by weight based on the N-vinyl-2-pyr-rolidone monomer :in the state diluted with substantially the same amount of acetic acid and perform oligomerization at lO to 100C
in a solvent such as benzene.
In the present invention, a water-soluble organic solvent is incorporated i71 the ink composition according to need. As such solvent, there are preferably employed dioxane, acetone, diacetone alcohol, cellosolves, carbitols, alcohols having l to 3 carbon atoms, pyridine, climethylformamide, dimethylsulfoxide and N-methyl-2-pyrrolidone.
.
Any of wa-ter-soluble dyes having such property that color change or formation of precipitates is not caused by incor-poration of an oxygen absorber such as mentioned above can be used in the present invention. For example, ;there are employed C. I. Direct Blue 236, C. I. Direct Blue 203, C. I. Direct Blue 202, C. I. Direct Blue 15, C. I. Acid Blue 7, C. I. Acid Blue 9, C. I. Acid Yellow 1, C. I. Direct Red 227, C. I. Direct Red 225, C. I. Acid Red 87, C. I. Acid Red 92, C. I. Acid Red 52, C. I.
Direct Black 51, Direct Deep Black (manufactured by Mitsubishi Kasei), Chlorazol Viscose Black B450 (manufactured by ICI), ~igro-sine G 140 (manufactured by ICI), Benzo Nerol VSF (manufactured by Rayer) and Alcohol Mazenta (manufactured by Shirado Kagaku).
These water-soluble dyes may be used singly or in the form of mix-tures of two or more of them.
If necessary, a surface tension adjusting agent may be incorporated into the in~ composition of the present invention.
As the surface tension adjusting agent, there can be used, Eor ex-ample, cationic surface active agents such as sodium alkyl sul-fates, anionic surface active agents such as alkyl pyridium sul-fates, non-ionic surface active agents such as polyoxyethylene alkyl ethers, and amphoteric surface active agents.
Moreover, the ink composition of the present invention may further comprise a viscosity modifier according to need. As the viscosity modifier, there can be mentioned, for example, cel-lulose derivatives such as hydroxypropyl cellulose, carboxymethyl cellulose and hydroxyethyl cellulose, and water-soluble resins such as polyvinyl alcohol, polyvinyl pyrrolidone, acrylic resins, styrene-acrylic copolymers and styrene-maleic acid copolymers.
The presence of Cu ion as a catalyst is effective for promoting the reaction represented by the above reaction formula 1.
The ink composition of the present invention preferably comprises 5 to ar(P/O of a water-soluble wetting agent such as men-tioned above, 0.1 to 10% by weight of a water-soluble dye such as - ~:
_g_ . .
1~69Z55 mentioned above and 0.5 to 1~/~ by wei~ht of an oxygen absorber such as mentioned above, with the balance being water. According to need, up to 50~/O by weight of water may be replaced by a water-soluble organic solvent such as mentioned above. Further, small amounts of a surface active agent, an antiseptic, a fungicide, a viscosity modifier and the like may be incorporated in the ink composition of the present invention according to need.
As will be apparent from the foregoing illustration, ac-cording to the present invention, there is provided an ink compos-ition in which a viscosity of 1 to 5 cps, a surface tension of 40to 50 dyne/cm and a very low concentration of dissolved oxygen can always be maintained at temperatures approximating room temperature.
When this ink composition is used for ink jet recording, it is pos- -sible to jet ink drops stably at a high speed in an ink jet record-ing apparatus, and therefore, the application range of ink jet re-cording can be remarkably broadened according to the present in-vention.
The present invention will now be described in detail by reference to the following Examples that by no means limit the~
scope of the invention. In these Examples, experiments were con-ducted by using the ink ~et recording apparatus shown in Fig. 4, but it must be noted that similar effects can be obtained by using other known ink vessels.~ ~ -, . :
Composition /O by weiqht - Polyethylene glycol ~300 (having a 20 molecular weight of about 300) Dye, C. I. Acid Red 92 5 -Distilled water 73 ~ ~
, ~ .. .- .
Sodium sulfite 2 ~
. ~ . .~ . .
A polyoxyethylene alkyl ether type surface active agent as a surface tension adjusting agent and sodium dehydroacetate as an antiseptic mildewproofing agent were incorporated in the above ::
~a69zs5 composition, each being at a concentration lower than 2000 ppm.
The resulting ink composition had a surface tension of 40 dyne/cm and a viscosity of 2.5 cps at room temperature (25C).
The so-prepared ink composition was placed in an ink ves-sel as shown in Fig. 4 and used for ink jet recording. The thres-hold voltage was 100-150 Vpp. Even after the ink composition had been stored for 18 months, the amount of dissolved oxygen was smaller than 0.0007 ml/ml and the threshold voltage was lower than 250 Vpp. Thus, it was confirmed that the ink composition retained the original excellent jetting property (adaptability to ink jet recording) even after 18 months' storage. Further, formation of precipitates or change of the color was not observed during storage~
Composition % by weiqht Diethylene glycol 15 Dye, C. I. Direct Blue 202 2 Distilled water 82 Sodium sulfite In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. The resulting ink composition had a surface tension of 45 dyne/cm and a viscosity of 1.7 cps at ` room temperature.
When the ink composition was subjected to the jetting test after 18 months' storage and properties were examined in the ; same manner as in Example 1, results as excellent as those obtained in Example l were similarly obtained.
` Composition /O by weiqht Glycerin 10 Ethylene glycol monoethyl ether 10 Dye, Direct Deep Black (manufactured by -Mitsubishi Kasei) ~: .
-11- ' :~': ,:
1~69255 EXAMPLE 3 (cont'd) Composition % by weiqht Distilled water 77 Sodium sulfite ~ 2 In the same manner as in Example 1, the surface tension -adjusting agent and antiseptic mildewproofing agent were incorpor-ated in the above composition. The resulting ink composition had a surface tension of 42 dyne/cm and a viscosity of 1.5 cps at room temperature.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1. ;
E ~PLE 4 Composition /O by weiqht Glycerin 20 Dye, C. I. Acid Blue 9 2.5 Distilled water 72.5 Sodium sulfite 5.0 In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. The resulting ink composition had a surface tension of 48 dyne/cm and a viscosity of 1.8 cps.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1.
Composition /O by weiqht Polyethylene glycol #300 (having a mole-cular weight of about 300) 14 Diethylene glycol 2S
.
:
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1~69255 EXAMPLE 5 (cont'd) Composition /O by weiqht Dye, C. I. Acid Blue 9 3 Distilled water ~ 57 Sodium sulfite In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. 1'he resulting ink composition had a surface tension of 40 dyne/cm and a viscosity of 2.6 cps.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1.
The following various compositions were prepared.
Composition A /O by weiqht Polyethylene glycol #600 (having a mole-cular weight of 600) 20.0 Dye, C. I. Direct Blue 15 1.0 Distilled water 76.0 Ammonium hydrogensulfite 3.0 Composition B Dk by weiqht 1,5-Pentane diol 17.6 Dye, C. I. Direct Red 225 1.0 Distilled water 78.4 Ammonium hydrogensulfite 3.0 Composition C /O by weiqht Dipropylene glycol 12.0 Polyethylene glycol #300 (having a mole- ~ ;
cular weight of 300) 15.0 , Dye, C. I. Acid Blue 9 1.0 ~
; ~ Distilled water 71.0 ~ -Potassium sulfite 1.0 -. .
~ -13-,' . .
~ 69Z55 Comp_sitlon D/O by weiqht Dipropylene glycol 15.0 Polyethylene glycol #600 (havinq a mole-cular weight of 600) 5.0 Polyvinyl pyrrolidone I (havinq a mole-cular weight of 40,000) 1.0 Dye, C. I. Acid Blue 9 1.0 Distilled water 75,0 Ammonium sulfite 3.0 Composition E % by weight 1,3-Butane diol 20.5 .
Glycerin 4.0 Polyvinyl alcohol (having a molecular 0.5 weight of 500) .
Dye, C. I. Direct Red 225 1.0 Distilled water 73,0 Potassium sulfite 1.0 mposition F /O by weiqht .
Diethylene glycol 15.0 Sorbitol 3,0 : Dye, C. I. Direct Blue 15 1.0 .
Distilled water 80.0 Potassium sulfite 1.0 Composition G~/O by wei~ht Diethylene glycol 15.0 : Sorbitol 3.0 Dye, Direct Red 225 1.0 . .
: Distilled water 78.0 Ammonium hydrogensulfite 3,0 ... ~.:
Composition H % by weiqht -. .
GLycerin 18.0 .
.
: Hydroxypropyl cellulose 1.0 ..
. .
: Dye, C. I. Direct: Red 225 1.5 ' ' :"':-~
-14- :.
- ., ~069ZSS
Composition H (cont'd)/0 by weiqht Distilled water 76.5 Ammonium hydrogensulfite 3.0 Composition I ~O by weiqht Diethylene glycol monoethyl ether10.0 Dye, C. I. Direct Blue 236 3.0 Sodium sulfite 1.0 Distilled water 86.0 Composition J % by weiqht Ethylene glycol monobutyl ether 30.0 Dye, C. I. Direct Red 225 2.0 Potassium sulfite 2.0 Distilled water 64.0 Acetone 2.0 Composition K /O by weiqht Ethoxy glycol 10.0 Diethylene glycol methyl ether 5.0 Dye, C. I. Acid Blue 9 3.0 Ammonium sulfite 2.5 ~-Methyl-2-pyrrolidone 3,0 Distilled water ~ 76.5 Composition L ~/O by weiqht Ethylene glycol monoethyl ether 15.0 Diethylene glycol monomethyl ether acetate 5.0 Dye, C. I. Acid Red 92 5.0 Potassium sulfite 1.0 Distilled water 74,0 Composition M % by weiqht Ethylene glycol monoethyl ether acetate 10~0 ;
- :
Propylene glycol 25.0 Dye, C. I. Direcl Blue 15 1.0 Ammonium sulfite ~ 3.0 . .
Distilled water ~ 61.0 ;
.' , ~692~5 Composition ~ ~/~ by weiqht Tripropylene glycol methyl ether15.0 Dye, C. I. Direct Blue 15 2.0 Potassium sulfite 7.0 Distilled water 76.0 Composition 0 % by weiaht Diethylene glycol monobutyl ether20.0 Dye, C. I. Acid Red 92 2.0 Sodium sulfite 1.0 Distilled water 77.0 Composition P /O by wei~ht ~-Vinyl-2-pyrrolidone oligomer (having an average molecular weight of 300)5.0 Dye, C. I. Direct Blue 202 2.0 Sodium sulfite 1.0 Distilled water 91.0 Ethylene glycol 1.0 Composition Q ~O by weiqht ~-Hydroxyethyl formamide 10.0 Dye, C. I. Direct Blue 15 2.5 Potassium sulfite 1.0 Distilled water 86.5 Composition R % by weiqht .
~ Ethylene glycol monobutyl ether13.0 `~ Glycerin 5.0 `
Hydroxypropyl cellulose (HPC-SL manufactured ; by ~ippon Soda) 1.0 Dye, C. I. Direct. Red 225 1.5 ~ ~ -:~ , :.:. ::
~ Distilled water 76.5 , ~
Ammonium hydrogerisulfite 3,0 In the same manner as in Example 1, the surface tenslon adjusting agent and antiseptic mildewproofing agent were incorpor~-ated into the foregoing compositions. It was found that each of ;~
. . ' ` '.
, ~ ~,''~.'.', 1~69~55 the so prepared ink compositions had a surface tension of 40 - 50 dyne/cm and a viscosity lower than 5 cps at room temperature.
In the same manner as described in Example 1, these ink compositions were subjected to the jetting te-st af-ter 18 months' storage and properties were examined. In each ink composition, obtained results were as excellent as in Example 1.
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: -17-1 . . . ':
ment of the amount of dissolved air is made. If the amount of dissolved air is too large, increase of the pressure for jetting cannot be precisely transferred through the ink, and therefore, it becomes difficult to perform recording precisely in response to electric signals.
The present invention relates to an ink composition for ink jet recording~which can be jetted stably in drops at a high ~ -speed.
More specifically, the present invention relates to an ink composition for ink jet recording which comprises a water- ~ -soluble wetting ag~ent (binder), water, a water-soluble dye and an ~ ~ ~
-1- ~ . :
oxygen absorber. More particularly the invention is concerned - with such an ink composition comprising 5 to 4~/0 by weight of the water-soluble wetting agent, 0.1 to l~/o by weight of the water-soluble dye and 0.5 to l~/o by weight of the oxygen absorber, and water' the ink composition having a viscosity lower than 5 cps, a surface tension of 40 to 50 dyne/cm and an amount of dissolved air less than 0.013 ml/ml at temperatures approximating room temperature.
In particular the dye is one which is not subject to colour change and does not form a precipitate in the presence of the oxygen ab~orber; and the oxygen absorber does not change the colour of the ink, does not generate nitrogen gas and does not form a precipitate.
The oxygen absorber is one which is soluble in the ink composltion and is thus suitably water-soluble.
The invention will now be described with reference to the accompanying drawings which show a preferred form thereof and wherein: ~
Fig. 1 is a diagram illustrating an embodiment of the ink jet recording apparatus for which the ink composition of the present invention is used;
Fig. 2 is a graph illustrating the relation between the amount of dissolved air in an ink and the standing time, which is observed when the ink from which dissolved air has been removed by a degasification treatment such as boiling is allowed l to stand in air ;~`
Fig. 3 is a graph illustrating an instance of the ;
relation between the amount of dissolved air in an ink and the threshold voltage of a recording head; and --,:' ~ . .
. . ~ ... . :
.. . .
gjgz55 Fig, 4 is a diagram illustrating an ink vessel com~ :
posed of a plastic film which is used for intercepting air from an ink.
Various apparatuses have been known for ink jet record-ing, and the ink composition of the present invention can be applied to these known apparatuses~ An instance of such ink jet recording apparatus will now be described by reference to Fig. 1.
Referring now to Fig. 1, a recording head 1 comprises a piezo-electric element 2, a vibrating plate 3 and an ink chamber 10. An ink 8 held in an ink vessel 7 is fed into the ink chamber 10 through an ink feed pipe 6 and the ink chamber 10 is filled with the ink 8. Reference numerals 4 and 5 represent a nozzle and an ink drop, respectively. The recording medium 9 is composed of pape~, cloth, wood or the like. :
In the recording apparatus having the above structure, when an electric signal 11 is applied between the piezo-electric element 2 and the vibrating plate 3, the piezo-electric element 2 ~ .
causes vibrations in response to the applied electric signal to : '`. ',', ,', .,:
' .:
:.
:.. . .
., .
: '.'' ~
;.
~ ' ,: ' '-'~ `' ' .'. ', ' .,,,~ ' ~ ', _ 2a -~9ZS5 increase the pressure in the ink 8 contained in the ink chamber 10. By this pressure increase, the ink 8 is jetted from the noz-zle 4 in the form of liquid drops 5, and the jetted ink drops 5 adhere onto the surface of the recording medi~m 9 to form thereon an image corresponding to the electric signal. This ink jet re-cording apparatus is detailed in the specifications of U.S. Pat-ent No. 3,747,120 and U.S. Patent No. 3,9~0,773.
In an ink jet recording apparatus of this type, for ex-ample, in order to record an original image having an A-4 size and a resolving degree of 6 lines per cm for 2 minutes, it is necessary for the recording head 1 to stably jet ink drops 5 in response to electric signals corresponding to image signals hav-ing a frequency lower than lO KHz. For attaining this feature, repeated increase of the pressure by vibrations of the piezo-elec-tric element 2 must be faithfully transferred through the ink 8.
When the ink used has a high viscosity, the resistance is enhanced on the wall surface of the ink chamber or the nozzle portion to cause pressure loss and hence, faithful transfer of the pressure is impossible. The influence of the surface tension of the ink on jetting of the ink is not serious, but too high a sur-face tension, of course, must be avoided. If the surface tension of the ink is too low, running of the ink takes place on the re- ;~
cording medium.
In the case where the amount of dissolved air in the ink is large, the higher the frequency of repetition of increase of the pressure, t:he more the ink comes to have properties as a compressible fluicl and the more the transfer of increase of the pressure is delayed.
As is seen from the foregoing illustration, when the viscosity of the ink is high or the amount of dissol~ed air is large, it is impossible to transfer the increase of the pressure faithfully and as a result, it is impossible to perform recording :~ .
~L~69255 faithfully in response to electric signals.
For the reasons set forth above, in order to jet ink drops stably at a high speed under the abovementioned recording conditions, an ink to be used for ink jet recording must satisfy the following requirements concerning physical properties at temp-eratures approximating room temperature:
(1) Viscosity : lower than 5 cps (2) Surface tension : 40 - 50 dyne/cm (3) Amount of dissolved air: less than about 0.013 ml/ml It is a primary object of the present invention to pro-vide an ink composition for ink jet recording, in which the fore-going requirements are sufficiently satisfied and especially in which the amount of dissolved air can be maintained at a very low level.
In general, the solubility of air in water is 0.0183 ml/ml as measured at 20C and one atmosphere, and it is known that this water solubility consists of a solubility of oxygen which is 0.0064 ml/ml and a solubility of nitrogen which is 0.0119 ml/ml.
We measured the solubility of air in an ink composition comprising water, a water-soluble wetting agent, a water-soluble dye and a water-soluble solvent and satisfying the foregoing re-quirements of the viscosity and surface tension, and as a result, .,.. ~.. : ~ ~ .
it was found that the solubility of air in such ink composition is substantially equal to the solubility in water. -As a result of our experiments, it was confirmed that -when in~ jet recording is carried out by using a recording head as shown in Fig. 1, if the amount of dissolved air is larger than 0.013 ml/ml, the response characteristic of the recording head is degraded.
When the driving voltage of the recording head exceeds 250 Vpp, air bubbles are readily sucked in the head from the noz-zle and jetting of the ink particles becomes unstable. As will be ; ~4~
- . . . .. - -. . . , .. ~ - . - ~ . . . , . . - -~69255 apparent from Fig. 3 illus~rating the influence of the amount of dissolved air in the ink on the minimum driving voltage (~hreshold) voltage) for jetting of the ink particles, as the amount of dis-solved air increases, in order to jet the ink particles, it is necessary to raise the driving voltage, and if the amount ol the dissolved air exceeds 0.013 ml/ml, the threshold voltage for jet-ting of the ink particles is higher than 250 Vpp and it becomes impossible to perform recording stably.
When an ink composition satisfying the foregoing require-ments for viscosity and surface tension was subjected to a degas-ification treatment such as boiling so that the requirement for the amount of dissolved air was satisfied and the degasified ink composition was allowed to stand in the ink jet recording apparatus shown in Fig. 1, it was found that the amount of dissolved air in the ink composition increased with the lapse of time as shown in Fig. 2 and the amount of dissolved air in the ink composition was as large as 0.013 ml/ml after the lapse of about 1 hour.
Some of us previously proposed an ink vessel as shown in Fig. 4 as means for eliminating the above disadvantage. Refer~
ring to Fig. 4, in this ink vessel, air is shut out from an ink 8 by a plastic film bag 12.
Resins having a low gas permeability, such as vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acryloni-trile copolymers, polyvinylidene chloride-coated nylon resins and polyvinylidene chloride-coated polyester resins, are preferably :
employed for formation of the plastic film bag 12. For example, when a vinylidene chloride-vinyl chloride copolymer (KREHALON
manufactured by Kureha Plastics Co., Ltd.), which is one of the materials having a lower gas permeability among those mentioned, was shaped into a film having a thickness of 40~ and the film was used as the film bag 12, the amount of dissolved air increased at a rate of about 0.002 ml/ml/day, and in the case of an ink com-_5_ , , ,:
~69Z~iS
position formed by removing an oxygen absorber from an ink com-position of Example 3 given hereinafter, the life o~ the ink com-position was prolonged by about 1 week.
However, no plastic material is capable of completely shutting out gases, and such prolon~ation of the ink life is of no significance from the practical viewpoint.
From the experimental results shown in Figure 2, we found that the critical lower value of the amount of air dissolved in an ink is substantially equal to the solubility o~ nitrogen of dissolved air in the ink and the influence of dissolved air can be substantially eliminated if dissolved oxygen is removed from dissolved air. It was also found that this can be accomplished by removing oxygen which is continually being dissolved in the ink.
This removal of dissolved oxygen, in general, may be :: :
accomplished by a physical method or chemical method. According ~`
to the former physical mèthod, oxygen is removed by boiling or pressure reduction, but it is difficult to perform the treatment continuously and maintain the intended effect for a long time ac-cording to this physical method. Therefore, we conducted research on a chemical method for removal of dissolved oxygen, and as a res- ;-. ~ - .: -ult, we found that dissolved oxygen can be effectively removed -~
, .. .
without any harmful influence on the quality of an ink by incorpor- ;
. . .
;` ation of a specific oxygen absorber. Based on this finding, we have now completed the present invention.
;~ In the present invention, a substance capable of chemi- ; -cally reacting with oxygen dissolved in an ink is used as an oxy- ~ ~
! : ` ~ ` :
~ gen absorber. As such substance, there can be mentioned various - .
- compounds, for example, metals such as iron chips, sulfites such as sodium sulfite, ammonium sulfite, potassium sulfite, sodium hydrogensulfite, potassium hydrogensulfite and ammonium hydrogen~
sulfite, polyhydric phenols such as pyrogallol, and other reduc-ing agents such as sodium trithionite and hydrazine~ However, in~
-:
: :
~ ~069255 order for these substances to be effectively used in the present invention, they must satisfy various requirements. For example, they must be easily soluble in an ink, they must not change the color of the ink, they must not generate nitrogen gas or the like by reaction with oxygen, and they must not form precipitates. In view of these requirements, sulfites such as sodium sulfite, am-monium sulfite, potassium sulfite, sodium hydrogensulfite, potas-sium hydrogensulfite and ammonium hydrogensulfite are most pre-ferred as oxygen absorbers. For example, when sodium sulfite is used as the oxygen absorber, it absorbs oxygen according to the following reaction: -2~a2S03 + 2 = 2~a2S4 (formula 1) When water, a polyhydric alcohol as a water-soluble wet-ting agent, a water-soluble dye and sodium sulfite are placed in an ink vessel of a vinylidene chloride-vinyl chloride copolymer as shown in Figure 4, the amount of air permeating the film vessel is 0.002 ml/ml/day and the portion accounted for oxygen is 0.0007 ml/ml/day. Accordingly, the amount of sodium sulfite in the ink composition necessary for absorbing the thus dissolved oxygen is 7.g x 10 6 g/ml/day. In order to maintain the amount of dissolved~
:~
oxygen in the ink composition at a level of 0.0007 ml/ml, sodium sulfite must be incorporated into the ink composition in an amount of about 0.5% by weight. In some ink compositions, this critical ~i . , concentration of sodium sulfite is higher than 0.5% by weight. In an ink composition containing sodium sulfite in an amount larger than the above critical value, the amount of oxygen dissolved in ~ ;~
the ink composition is maintained at a very low level and this ef-fect is manifested until all of sodium sulfite incorporated lS con~
sumed. For exampLe, if sodium sulfite is incorporated in an amount~
of 1% by weight, the life~of the ink is about 630 days. However, i~ the amount of sodium sulfite incorporated exceeds 10% by weighit~, .. ..
the ink is readily dried to cause clogging of the nozzle.
' ' ~; ' ; ~7~
:
~)69255 The water-soluble we-tting agent that is used in the present invention includes polyhydric alcohols which are liquid at temperatures approximating room temperature, such as glycerin, ethylene glycol, polyethylene glycol, propylene glycol, methyl glucoside, trimethylolpropane, trimethylolethane, neopentyl glycol, sorbitol and mannitol, alkyl ethers of aliphatic polyhydric alco-hols, which are liquid at temperatures approximating room temp-erature, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, ethoxy glycol, monopropylene glycol methyl ether, dipropylene glycol methyl ether ;~ -and tripropylene glycol methyl ether, mono-acetates of alkyl ethers of aliphatic polyhydric alcohols, which are liquid at temperatures approximating room temperature, such as ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate and di-ethylene glycol monoethyl ether acetate, hydroxyalkyl formamides which have l to 4 carbon atoms in the alkyl group, and N-vinyl-2-pyrrolidone oligomers which are liquid at temperatures approximat- ~`
ing room temperature.
These water-soluble wetting agents may be used singly or in the form of mixtures of two or more of them.
The above-mentioned N-vinyl-2-pyrrolidone oligomers can be synthesized by adding concentrated sulfuric acid as a catalyst in an amount of 0.05 to 5% by weight based on the N-vinyl-2-pyr-rolidone monomer :in the state diluted with substantially the same amount of acetic acid and perform oligomerization at lO to 100C
in a solvent such as benzene.
In the present invention, a water-soluble organic solvent is incorporated i71 the ink composition according to need. As such solvent, there are preferably employed dioxane, acetone, diacetone alcohol, cellosolves, carbitols, alcohols having l to 3 carbon atoms, pyridine, climethylformamide, dimethylsulfoxide and N-methyl-2-pyrrolidone.
.
Any of wa-ter-soluble dyes having such property that color change or formation of precipitates is not caused by incor-poration of an oxygen absorber such as mentioned above can be used in the present invention. For example, ;there are employed C. I. Direct Blue 236, C. I. Direct Blue 203, C. I. Direct Blue 202, C. I. Direct Blue 15, C. I. Acid Blue 7, C. I. Acid Blue 9, C. I. Acid Yellow 1, C. I. Direct Red 227, C. I. Direct Red 225, C. I. Acid Red 87, C. I. Acid Red 92, C. I. Acid Red 52, C. I.
Direct Black 51, Direct Deep Black (manufactured by Mitsubishi Kasei), Chlorazol Viscose Black B450 (manufactured by ICI), ~igro-sine G 140 (manufactured by ICI), Benzo Nerol VSF (manufactured by Rayer) and Alcohol Mazenta (manufactured by Shirado Kagaku).
These water-soluble dyes may be used singly or in the form of mix-tures of two or more of them.
If necessary, a surface tension adjusting agent may be incorporated into the in~ composition of the present invention.
As the surface tension adjusting agent, there can be used, Eor ex-ample, cationic surface active agents such as sodium alkyl sul-fates, anionic surface active agents such as alkyl pyridium sul-fates, non-ionic surface active agents such as polyoxyethylene alkyl ethers, and amphoteric surface active agents.
Moreover, the ink composition of the present invention may further comprise a viscosity modifier according to need. As the viscosity modifier, there can be mentioned, for example, cel-lulose derivatives such as hydroxypropyl cellulose, carboxymethyl cellulose and hydroxyethyl cellulose, and water-soluble resins such as polyvinyl alcohol, polyvinyl pyrrolidone, acrylic resins, styrene-acrylic copolymers and styrene-maleic acid copolymers.
The presence of Cu ion as a catalyst is effective for promoting the reaction represented by the above reaction formula 1.
The ink composition of the present invention preferably comprises 5 to ar(P/O of a water-soluble wetting agent such as men-tioned above, 0.1 to 10% by weight of a water-soluble dye such as - ~:
_g_ . .
1~69Z55 mentioned above and 0.5 to 1~/~ by wei~ht of an oxygen absorber such as mentioned above, with the balance being water. According to need, up to 50~/O by weight of water may be replaced by a water-soluble organic solvent such as mentioned above. Further, small amounts of a surface active agent, an antiseptic, a fungicide, a viscosity modifier and the like may be incorporated in the ink composition of the present invention according to need.
As will be apparent from the foregoing illustration, ac-cording to the present invention, there is provided an ink compos-ition in which a viscosity of 1 to 5 cps, a surface tension of 40to 50 dyne/cm and a very low concentration of dissolved oxygen can always be maintained at temperatures approximating room temperature.
When this ink composition is used for ink jet recording, it is pos- -sible to jet ink drops stably at a high speed in an ink jet record-ing apparatus, and therefore, the application range of ink jet re-cording can be remarkably broadened according to the present in-vention.
The present invention will now be described in detail by reference to the following Examples that by no means limit the~
scope of the invention. In these Examples, experiments were con-ducted by using the ink ~et recording apparatus shown in Fig. 4, but it must be noted that similar effects can be obtained by using other known ink vessels.~ ~ -, . :
Composition /O by weiqht - Polyethylene glycol ~300 (having a 20 molecular weight of about 300) Dye, C. I. Acid Red 92 5 -Distilled water 73 ~ ~
, ~ .. .- .
Sodium sulfite 2 ~
. ~ . .~ . .
A polyoxyethylene alkyl ether type surface active agent as a surface tension adjusting agent and sodium dehydroacetate as an antiseptic mildewproofing agent were incorporated in the above ::
~a69zs5 composition, each being at a concentration lower than 2000 ppm.
The resulting ink composition had a surface tension of 40 dyne/cm and a viscosity of 2.5 cps at room temperature (25C).
The so-prepared ink composition was placed in an ink ves-sel as shown in Fig. 4 and used for ink jet recording. The thres-hold voltage was 100-150 Vpp. Even after the ink composition had been stored for 18 months, the amount of dissolved oxygen was smaller than 0.0007 ml/ml and the threshold voltage was lower than 250 Vpp. Thus, it was confirmed that the ink composition retained the original excellent jetting property (adaptability to ink jet recording) even after 18 months' storage. Further, formation of precipitates or change of the color was not observed during storage~
Composition % by weiqht Diethylene glycol 15 Dye, C. I. Direct Blue 202 2 Distilled water 82 Sodium sulfite In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. The resulting ink composition had a surface tension of 45 dyne/cm and a viscosity of 1.7 cps at ` room temperature.
When the ink composition was subjected to the jetting test after 18 months' storage and properties were examined in the ; same manner as in Example 1, results as excellent as those obtained in Example l were similarly obtained.
` Composition /O by weiqht Glycerin 10 Ethylene glycol monoethyl ether 10 Dye, Direct Deep Black (manufactured by -Mitsubishi Kasei) ~: .
-11- ' :~': ,:
1~69255 EXAMPLE 3 (cont'd) Composition % by weiqht Distilled water 77 Sodium sulfite ~ 2 In the same manner as in Example 1, the surface tension -adjusting agent and antiseptic mildewproofing agent were incorpor-ated in the above composition. The resulting ink composition had a surface tension of 42 dyne/cm and a viscosity of 1.5 cps at room temperature.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1. ;
E ~PLE 4 Composition /O by weiqht Glycerin 20 Dye, C. I. Acid Blue 9 2.5 Distilled water 72.5 Sodium sulfite 5.0 In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. The resulting ink composition had a surface tension of 48 dyne/cm and a viscosity of 1.8 cps.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1.
Composition /O by weiqht Polyethylene glycol #300 (having a mole-cular weight of about 300) 14 Diethylene glycol 2S
.
:
' . ,. :.
1~69255 EXAMPLE 5 (cont'd) Composition /O by weiqht Dye, C. I. Acid Blue 9 3 Distilled water ~ 57 Sodium sulfite In the same manner as in Example 1, the surface tension adjusting agent and antiseptic mildewproofing agent were incorpor-ated into the above composition. 1'he resulting ink composition had a surface tension of 40 dyne/cm and a viscosity of 2.6 cps.
In the same manner as described in Example 1, the ink composition was subjected to the jetting test after 18 months' storage and properties were examined. Obtained results were as excellent as those obtained in Example 1.
The following various compositions were prepared.
Composition A /O by weiqht Polyethylene glycol #600 (having a mole-cular weight of 600) 20.0 Dye, C. I. Direct Blue 15 1.0 Distilled water 76.0 Ammonium hydrogensulfite 3.0 Composition B Dk by weiqht 1,5-Pentane diol 17.6 Dye, C. I. Direct Red 225 1.0 Distilled water 78.4 Ammonium hydrogensulfite 3.0 Composition C /O by weiqht Dipropylene glycol 12.0 Polyethylene glycol #300 (having a mole- ~ ;
cular weight of 300) 15.0 , Dye, C. I. Acid Blue 9 1.0 ~
; ~ Distilled water 71.0 ~ -Potassium sulfite 1.0 -. .
~ -13-,' . .
~ 69Z55 Comp_sitlon D/O by weiqht Dipropylene glycol 15.0 Polyethylene glycol #600 (havinq a mole-cular weight of 600) 5.0 Polyvinyl pyrrolidone I (havinq a mole-cular weight of 40,000) 1.0 Dye, C. I. Acid Blue 9 1.0 Distilled water 75,0 Ammonium sulfite 3.0 Composition E % by weight 1,3-Butane diol 20.5 .
Glycerin 4.0 Polyvinyl alcohol (having a molecular 0.5 weight of 500) .
Dye, C. I. Direct Red 225 1.0 Distilled water 73,0 Potassium sulfite 1.0 mposition F /O by weiqht .
Diethylene glycol 15.0 Sorbitol 3,0 : Dye, C. I. Direct Blue 15 1.0 .
Distilled water 80.0 Potassium sulfite 1.0 Composition G~/O by wei~ht Diethylene glycol 15.0 : Sorbitol 3.0 Dye, Direct Red 225 1.0 . .
: Distilled water 78.0 Ammonium hydrogensulfite 3,0 ... ~.:
Composition H % by weiqht -. .
GLycerin 18.0 .
.
: Hydroxypropyl cellulose 1.0 ..
. .
: Dye, C. I. Direct: Red 225 1.5 ' ' :"':-~
-14- :.
- ., ~069ZSS
Composition H (cont'd)/0 by weiqht Distilled water 76.5 Ammonium hydrogensulfite 3.0 Composition I ~O by weiqht Diethylene glycol monoethyl ether10.0 Dye, C. I. Direct Blue 236 3.0 Sodium sulfite 1.0 Distilled water 86.0 Composition J % by weiqht Ethylene glycol monobutyl ether 30.0 Dye, C. I. Direct Red 225 2.0 Potassium sulfite 2.0 Distilled water 64.0 Acetone 2.0 Composition K /O by weiqht Ethoxy glycol 10.0 Diethylene glycol methyl ether 5.0 Dye, C. I. Acid Blue 9 3.0 Ammonium sulfite 2.5 ~-Methyl-2-pyrrolidone 3,0 Distilled water ~ 76.5 Composition L ~/O by weiqht Ethylene glycol monoethyl ether 15.0 Diethylene glycol monomethyl ether acetate 5.0 Dye, C. I. Acid Red 92 5.0 Potassium sulfite 1.0 Distilled water 74,0 Composition M % by weiqht Ethylene glycol monoethyl ether acetate 10~0 ;
- :
Propylene glycol 25.0 Dye, C. I. Direcl Blue 15 1.0 Ammonium sulfite ~ 3.0 . .
Distilled water ~ 61.0 ;
.' , ~692~5 Composition ~ ~/~ by weiqht Tripropylene glycol methyl ether15.0 Dye, C. I. Direct Blue 15 2.0 Potassium sulfite 7.0 Distilled water 76.0 Composition 0 % by weiaht Diethylene glycol monobutyl ether20.0 Dye, C. I. Acid Red 92 2.0 Sodium sulfite 1.0 Distilled water 77.0 Composition P /O by wei~ht ~-Vinyl-2-pyrrolidone oligomer (having an average molecular weight of 300)5.0 Dye, C. I. Direct Blue 202 2.0 Sodium sulfite 1.0 Distilled water 91.0 Ethylene glycol 1.0 Composition Q ~O by weiqht ~-Hydroxyethyl formamide 10.0 Dye, C. I. Direct Blue 15 2.5 Potassium sulfite 1.0 Distilled water 86.5 Composition R % by weiqht .
~ Ethylene glycol monobutyl ether13.0 `~ Glycerin 5.0 `
Hydroxypropyl cellulose (HPC-SL manufactured ; by ~ippon Soda) 1.0 Dye, C. I. Direct. Red 225 1.5 ~ ~ -:~ , :.:. ::
~ Distilled water 76.5 , ~
Ammonium hydrogerisulfite 3,0 In the same manner as in Example 1, the surface tenslon adjusting agent and antiseptic mildewproofing agent were incorpor~-ated into the foregoing compositions. It was found that each of ;~
. . ' ` '.
, ~ ~,''~.'.', 1~69~55 the so prepared ink compositions had a surface tension of 40 - 50 dyne/cm and a viscosity lower than 5 cps at room temperature.
In the same manner as described in Example 1, these ink compositions were subjected to the jetting te-st af-ter 18 months' storage and properties were examined. In each ink composition, obtained results were as excellent as in Example 1.
. .
' '', ',; ~ ' ~ ; ' '' -':
. . .
' ~
'' .i''' ,' , , , ' ' ":
"
: -17-1 . . . ':
Claims (8)
1. An ink composition for ink jet recording which comprises 5 to 40% by weight of a water-soluble wetting agent, 0.1 to 10% by weight of a water-soluble dye which is not subject to colour change and formation of precipitates in the presence of an oxygen absorber and 0.5 to 10% by weight of an oxygen absorber which does not change the colour of the ink, does not generate nitrogen gas and does not form precipitates, and water, the ink composition having a viscosity less than 5 cps, a surface tension of 40 to 50 dyne/cm and a content of dissolved air less than 0.013 ml/ml at temperatures approximating room temperature
2. An ink composition for ink jet recording as set forth in claim 1, wherein the wetting agent is at least one compound selected from the group consisting of polyhydric alcohols, alkyl ethers of aliphatic polyhydric alcohols, mono-acetates of alkyl ethers of aliphatic polyhydric alcohols, hydroxyalkyl formamides and N-vinyl-2-pyrrolidone oligomers.
3, An ink composition according to claim 1, wherein the oxygen absorber is water-soluble.
4. An ink composition for ink jet recording as set forth in claim 1, wherein the oxygen absorber is at least one compound selected from the group consisting of sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogensulfite, potassium hydrogensulfite and ammonium hydrogensulfite.
5. An ink composition according to claim 1, 3 or 4, wherein said oxygen absorber is sodium sulfite.
6. An ink composition according to claim 1, 3 or 4, further including a water-soluble organic solvent.
7. An ink composition according to claim 1, 3 or 4, further including a surface tension adjusting agent.
8. An ink composition according to claim 1, 3 or 4, further including a viscosity modifier.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14558375A JPS5274406A (en) | 1975-12-05 | 1975-12-05 | Ink for ink jet recording |
| JP13601776A JPS5361412A (en) | 1976-11-12 | 1976-11-12 | Ink jet recording ink |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1069255A true CA1069255A (en) | 1980-01-08 |
Family
ID=26469707
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA267,069A Expired CA1069255A (en) | 1975-12-05 | 1976-12-03 | Ink composition for ink jet recording |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1069255A (en) |
| DE (1) | DE2654984C3 (en) |
| GB (1) | GB1526017A (en) |
| IT (1) | IT1124795B (en) |
| SE (1) | SE421628B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2755773C2 (en) * | 1977-12-14 | 1982-04-15 | Siemens AG, 1000 Berlin und 8000 München | Ink for piezoelectrically operated ink pens |
| JPS5582175A (en) * | 1978-12-18 | 1980-06-20 | Konishiroku Photo Ind Co Ltd | Ink composition for ink jet recording |
| CA1147907A (en) * | 1979-11-07 | 1983-06-14 | Kenneth E. Edds | Water-based ink composition |
| JPS6050393B2 (en) | 1980-06-13 | 1985-11-08 | 富士写真フイルム株式会社 | water-based ink composition |
| JPS575771A (en) | 1980-06-13 | 1982-01-12 | Fuji Photo Film Co Ltd | Formation of colored image by ink jetting method |
| US4395287A (en) * | 1980-12-01 | 1983-07-26 | Canon Kabushiki Kaisha | Liquid recording material |
| US4508570A (en) * | 1981-10-21 | 1985-04-02 | Ricoh Company, Ltd. | Aqueous ink for ink-jet printing |
| JPS6033145B2 (en) * | 1982-10-27 | 1985-08-01 | 三菱化学株式会社 | recording liquid |
| JPS5980475A (en) * | 1982-10-29 | 1984-05-09 | Ricoh Co Ltd | Aqueous ink composition |
| JPS6215270A (en) * | 1985-07-15 | 1987-01-23 | Canon Inc | Recording liquid and recording method using same |
| EP0363139B1 (en) * | 1988-10-03 | 1994-12-07 | Seiko Epson Corporation | A recording ink for an ink jet printer |
| CA2016076A1 (en) * | 1989-05-05 | 1990-11-05 | Judith D. Auslander | Ink compositions for ink jet printers |
| JPH09279077A (en) * | 1996-04-17 | 1997-10-28 | Brother Ind Ltd | Water-base recording ink and ink jet recording method |
| US20030151028A1 (en) * | 2002-02-14 | 2003-08-14 | Lawrence Daniel P. | Conductive flexographic and gravure ink |
-
1976
- 1976-11-30 GB GB4984976A patent/GB1526017A/en not_active Expired
- 1976-12-03 SE SE7613599A patent/SE421628B/en not_active IP Right Cessation
- 1976-12-03 IT IT3011876A patent/IT1124795B/en active
- 1976-12-03 DE DE19762654984 patent/DE2654984C3/en not_active Expired
- 1976-12-03 CA CA267,069A patent/CA1069255A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2654984C3 (en) | 1980-11-20 |
| DE2654984B2 (en) | 1980-03-27 |
| SE7613599L (en) | 1977-06-06 |
| DE2654984A1 (en) | 1977-06-16 |
| SE421628B (en) | 1982-01-18 |
| IT1124795B (en) | 1986-05-14 |
| GB1526017A (en) | 1978-09-27 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |