CA1147907A - Water-based ink composition - Google Patents
Water-based ink compositionInfo
- Publication number
- CA1147907A CA1147907A CA000360331A CA360331A CA1147907A CA 1147907 A CA1147907 A CA 1147907A CA 000360331 A CA000360331 A CA 000360331A CA 360331 A CA360331 A CA 360331A CA 1147907 A CA1147907 A CA 1147907A
- Authority
- CA
- Canada
- Prior art keywords
- ink composition
- dye
- weight
- ink
- water
- 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.)
- Expired
Links
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
- C09D11/30—Inkjet printing inks
- C09D11/32—Inkjet printing inks characterised by colouring agents
- C09D11/328—Inkjet printing inks characterised by colouring agents characterised by dyes
Abstract
Abstract An aqueous ink composition containing a dye and ammonium hydroxide and being substantially free of a resinous binder which is insoluble in water at a pH
of about 7 or less is provided.
of about 7 or less is provided.
Description
rl~
~.TER~.BASED INK COMPOSITI~
. .
Descx~ptlon Tech!nical Field :
The present in~ention is concerned with aqueous ink compositions which'exhibit ~ood water fastness without requ~xing t~e presence of a resinous binder in the compositi~n~ The'pres'ent invention is especially con-cerned with'aqueous ~nk'compositions which are useful as jet printing inks.
. .
B~ckground Art The basic technique'employed in jet printing involve~
us~n~ at least one'~nk'~et nozzle assembly attached to a pressurized source of ~nk. Each ink nozzle has a small orifice gener~lly with'a diameter of about 0.0005 to about 0,0028 inches which'~s energized by an electro-mechanical transducer to emit a continuous stream of generally unifo~ ink droplets at a rate of about 20 to about 200 kilohertz. The stream of droplets is directed onto the sur~ace of a mo~ing writing ~edium, such as . 20 paper. The stream. of droplets is controlled to form the desired printed characters in response to video signals der~ved from an electronic character generator and in response to an electrostatic deflection system~
In particular, the jet printers are adapted for pro-~iding a record on a writing medium by generating a series of ink drops, applying a charge successively on each o~ the ~nk drops in respon e to a signal which is recei~ed by the'printex, The drops are then directed along a path between two parallel conductive plates.
A deflect~on field, which is generated at a bias poten-tial, is applied to these plates with the result that the ink drops are deflected so that they reach the writing medium. They provide a representation, charac-teristic of the information contained in t~e signals.
,.. . .
1~79~7
~.TER~.BASED INK COMPOSITI~
. .
Descx~ptlon Tech!nical Field :
The present in~ention is concerned with aqueous ink compositions which'exhibit ~ood water fastness without requ~xing t~e presence of a resinous binder in the compositi~n~ The'pres'ent invention is especially con-cerned with'aqueous ~nk'compositions which are useful as jet printing inks.
. .
B~ckground Art The basic technique'employed in jet printing involve~
us~n~ at least one'~nk'~et nozzle assembly attached to a pressurized source of ~nk. Each ink nozzle has a small orifice gener~lly with'a diameter of about 0.0005 to about 0,0028 inches which'~s energized by an electro-mechanical transducer to emit a continuous stream of generally unifo~ ink droplets at a rate of about 20 to about 200 kilohertz. The stream of droplets is directed onto the sur~ace of a mo~ing writing ~edium, such as . 20 paper. The stream. of droplets is controlled to form the desired printed characters in response to video signals der~ved from an electronic character generator and in response to an electrostatic deflection system~
In particular, the jet printers are adapted for pro-~iding a record on a writing medium by generating a series of ink drops, applying a charge successively on each o~ the ~nk drops in respon e to a signal which is recei~ed by the'printex, The drops are then directed along a path between two parallel conductive plates.
A deflect~on field, which is generated at a bias poten-tial, is applied to these plates with the result that the ink drops are deflected so that they reach the writing medium. They provide a representation, charac-teristic of the information contained in t~e signals.
,.. . .
1~79~7
-2-The general configuration of ink systems employed with ~nk jet printers ~nclude an ink sump whichstoresthe ink. The sump feeds a compressor which in turn feeds a conduit, which is connected to an ~nk jet nozzle, An electromechanical transducer is ~mployed to ~ibxate the nozzle at some suitable high frequency, which after the ink is injected through an orifice of the nozzle in a stream, causes the stream to bxeak into the individual drops. It is desired for proper charging of the individual drops that the breakup of the stream occur within the chargin~ slot. The charging slot is the most desirable point alony the path of the`stream for the actual ch~rge of each ~ndividual drop to ~e placed.
To be suitable as an ink in ink jet printing systems~ the ink must possess a number of important characteristic~ or properties. For instance, the ink must have a viscosity suitable for providing the pro-per flow characteristics in the jet printing process.
Most ink jet printing inks have viscosities within the rangeof about 1 to about 10 centipoise at 75F
and preferably about 2 to about 6 centipoise at about 75F. Of course, depending on the particular config-urati~n of the des~red ink jet printing apparatus to be employed, the viscosity of a particular composition c~n vary somewhat.
Moreover, in view of the small orifice dia-meters of the nozzle employed, nozzle clogging can hecome ~ major concern. Therefore, an ink to be em-ployed in an ink jet printing operation cannot containparticulate m~terial which could clog the orifice of the nozzle. ~urthermore, the ink employed should not be one which would dry and plug the orifice when the system is not in operation. Another requirement for 1~79~)7 an ink jet printing ink is that it be electrically con~uct~Ve. The ink should also have a rel~tively fas~ drying time and sh~uld be resistant to smearing~
Since the ink should be resistant to smearing on the writing medium, the ink must ha~e the property of being readily absoxbèd into the writing medium.
At the present time, commercially available ànk jet co~pos~tions contain an organic resin bondîng agent to ix or bond the dye to the substrate. It has been believed that the use of a synthetic resin binder is necessary for such prupose. For instance, U.S.
Patent 4,136,076 to Daniels suggests an ink jet print-ing camposition where~y the permanence and adhesion to the target ~urface is improved by the presence of certain p~lymers which conta~n unesterified free carbonyl groups and certain multivalent metals to provide ~ cross~linking of the polymer. Daniels ~urther su~gests the use of certain volatile bases including ammonium hydroxide in order to render the polymers soluble in water or alcohol required by Daniels because of the presence of the polymer.
Moreover, U.S. Patent 3,891,581 to Argenio suggests a water dilutable transfer ink composition for use in flexographic and xotogravure heat transfer printing processes which contain a thermoplastic resin such as a polyester obtained by reacting a polyol partially esterified rosin with maleic anhydride and/or fumaric acid. These compositions can contain ammonium hydroxide. The ammonium hydroxide is present so that the composition has a pH of between about 8 and 9.
U.S. Patent 4,150!997 to Hayes also suggests the presence of cert~in bases to ink compositions con-taining a fluorescent pigment. The fluorescent pigment is a mixture of a dye ~nd an organic resin which ap-parently is cured (along theselines, see column 2, ~L1479~37 ~4-lin~s 2Q-23 and colu~n 3, lines 12 and 13), The base ~s ~dded to solubilize the pigment~ For in-stance, the base c~n be ammonium hydroxide which, according to the disclosure of this patent, forms a quaternary salt with the fluorescent pigment.
U.S. Patent 3,846,141 to Ostergren et al suggests jet printing ink compositions which can contain a base such ~s an alkanol a~ine, a monovalent hydrox-ide suchas an alkali metal hydroxide, ammonium hydrox~de or morpholine to provide a composition having a pH above ~bout 9. The base is disclosed as enabling the ink composition to be modi~ied by the incorporation of a resinous system such as a modi~ied styrene-maleic anhydride resln (see column 3, lines 53 et seq.l.
-U~S. Patent 3,594,736 to Hertz et al is of generalintere$t~
Disclosure of Invention The present invention, contrary to the suggestion in the prior art, does not require the presence of a resinous bonding agent in order to achieve water fastness of the dye. According to the present invention, the pH of the composition is ~djusted by incorporating ammonium hydroxide which maintains the dye dissolved while the ink is ln the bottle or ~1~7~7 ~ 5-container but evaporates after the ink is printed onto the substrate thereby reducing the pH and thereby rendering the ink insoluble on the paper, According to the present invention, a resinous binder is not necessary to achieve ~oth proper pH ~alance and water fastness as previously ~elieved.
The present inVention is concerned with an ink composition which consists essentially of an a~ueous solution o~ an organic direct dye and ammonium hydroxide, The ammonium hydroxide is present in the composition in an amount sufficient to provide the solution with a pH of at least about 9.5. In addi-t~on, the ~queous solution is free from resinous Binder components which are insoluble in water at a pH of ~bout 7 or less.
Brief ~escription of Drawing The drawing is a graph of water resistances of the inks of ~xamples 6 and 7.
Best and Various Modes ~or Carrying Out Invention According to the present invention, it is essential that the pH of the aqueous solution be provided by the addition of ammonium hydroxide as the basic material.
It has been noted, aswill be discussed hereinbelow, that the use of other basic materials such as sodium hydroxide and sodium carbonate have not provided the de~ree of water fastness achieved by the present in-vention when a synthetic resinous binder is not pre-sent in the composltion. Also, the addition of other volatile hases such as ammonium carbonate or morpholine does not provide the same desired results achieved with ~L1479~17 ~ 6~
ammonium hydroxide. The pH of the solution must be at least about 9.5 and is preferably at least about 10.
Generally the pH o~ the solution is not greater than ab~ut 12. The composition generally contains about ,05 to about 5% ~y ~eight of ammonium hydroxide and preferahly ~bout 0,1 to 3% ~y weight in order to achie~e the necessa~ pH level.
In addition~ the compos~tion must contain a coloring material which ts an ~rganic direct dye or mixture of such'dyes. The dyes employed should be soluble in water at a pH o~ a~out 9.5 and/or higher but substan-tially insoluble at a pH of 7 or less to achieve the ~esults obta,ined by the present invention. For in-stance, dyes such as Direct ~lue 1 and Direct Black 80 which Are soluble at a pH o~ 7 or belowdid not exhibit ~ater fastness when formulated with ammonium hydroxide ~ithout a xesinous bonding agent.
The use of pigments or other forms of particular matertal is not desirable since such materials tend to clog up the ~rery small orifices of the jet printer.
Preferred dyes of the present invention are the com-mercially available direct dyes which generally contain an ionizable inor~anic salt, such as Glauber salts, or sodium chloride which has been added during manufac-ture in order to standardize the dye lot. The inorganic~aterial thus renders the dye conducti~e whereby the ink drops are capable of b~ing deflected in an electro-magnetic field during jet printing. Such direct dyes are ~ell known to those skilled in the art and are commercially available, as represented by the CI Direct Black 38 dyes; Di~ect Black 19 dye; Amanil-P*dye;
.
~' , -- .
79V~7 Di~ect Blue 106; Direct Black 163; and Food Black 2.
A particularly pre~erred dye is Direct Black 19 dye.
It has been noted that Direct Black 19, Direct Black 38~ and ~m~nil-P dye have exhibited excellent water fast properties when employed with the ammonium hydrox~de. Howevex, var~ous other of the direct dyes, such as D~xect Blue 106, Direct Black 163, and Food Black 2 have been ~ormulated along with ammonium hydroxide but such, although exhibiting some degree of improved watex fastness, have not shown the excep-; tionally high degree ach~eved by the use of the above three-mentioned dyes.
The dye is generall~ present in the composition in amounts o~ about 0,5 to about 8% by ~eight, and preferahl~ ~bout 2 to about 5% ~y weight. In addition, it is noted that the water employed shbuld be distilled water which do~s not contain any substantial amounts of ions and can be considered deionized water.
The compositions can also contain auxiliary constituents such as humectants, bioc~des, fungicides, and stabil-izers or solubilizers.
Examples of some suitable humectants include gylcol and glycol derivatives, such as the polyalkylene glycols (such as polyethylene glycols and polypropylene glycols], propylene glycol, lower alkyl ethers of ethylene glycol, or diethylene glycol (such as ethylene glycol monomethyl-ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and ethylane glycol monobutyl ether); and glycerine. The humectant can generally be ~7~)7 pre~ent in the co~position, when employed, in a~ounts of ~out 5 to about 45% by weight. The hu~ectants are employed to retard the dxying of the inks to prevent prernature drying in the capillaries or other portions of the jet printing apparatus.
Examples of some solub~lizing agents to insure that the dye remains in solution include those mentioned in U.S~ Patent 3,846,141, such as N~methyl-2-pyrroli-done; ~ -dihydroxyethyl sulfide, N-vinyl pyrrolidone, substituted pyrrolidone, such as Solvofen HM-Gaf, 4-methoxy-4 methyl pentanone-2 and tetrahydro~
furfuryl alcohol. The a~ount of solubilizing agent generall~ employed is up to about 5% by weight andpreferably ~out 0.5 to about 4% by weight based upon the total weight o~ the ink composition.
Also, the ink composition may include a preservative to inhibit the irowth of bacteria during storage, particul~rly when the compositions are to be stored for prolonged periods of time. The bacteria might cloy the orifice of the jet printer if not prevented from growing. Examples of some suitabie preservatives are sodium omadine, and 6-acetoxy-2,4-dimethyl-m dioxane. Such are usually employed in amounts of up to about 1% by weight.
The composition ~ight also contain a chelating agent, such as ethylenedia~ine tetraacetic acid, tetra-sodium, generally xeferred to as EDTA. Chelating agents are employed for complexing metal ions such as ixon, Zinc, or magnesium present within the aqueous composition in order to prevent the precipitation of metal ions dissolved in the water or present along ~7907 witll the dye The chelating agent is generally employed in ~mounts up to about 5~ ~y weight and preferably abollt 0.05 to about 0.5% by wei~ht.
It is desirable that the compositions of the present invention have a viscosity of about 1.2 to about 10 centipoi~e at 75~ and prefera~ly about 2 to about 6 centipo~se at 75~F.
The compositions of the present invention can be pre-pared by thbroughly mixing the constituents to insure uniform mixin~ and complete dissolution of the dye and then ~ilter;~ng the resulting composition to remove any particulate contamination~ Filtration of the composition after mixing the components is highly desir~ble in oxder to remove from the composition particulate matter~ such as contamination or undissolved dye which mi~ht otherwise serve to clog or obstruct the oxifices of a jet prlnter during use. It is gen-erally pre~erred to filter the compositions of the present invertion in order to remove particulate matter having a diameter greater than about 2 microns, and preferably greater than about 1 micron in order to insure that the obstruction o~ the jet printed ~ill be avoided.
In accordance with the preferred method of preparing t~e compositions of the present invention, the water vehicle, a~monium hydroxide, any humectants, if present, and any solubilizing agent~ if employed, are first thoroughtly mixed in a manner in which the introduc-tion of air into the mixture or foaming is substantially avoided. After ~ uniform mlxture is obtained, the preserVative~ i~ employed~isslowly added and mixing LE979~020 :~147907 .`10-i5 continued until ~ unifo~m mixture is obtained.
Afte~ this, the oxganic dye is slowly sifted into the re~ulting mixture ~hile~a~itation is continued to en ure substantially complete dissolution of the dye S in the aqueous solution~ After dissolution of the dye, the ink composition is filtered to remove any particulate ~atter contained therein having a size greater th~n the desired maximum particle size.
The following non~limiting examples are presented wherein amounts are by weight unless the contrary is stated.
Example 1 To about 857.5 grams of deionized water at 72~F are added w~th stirring about 10 grams of a 30% solution lS of ammonium hydroxide; about 100 grams of Carbowax*200 (i.e. poLyethylene glycol); and about 32.5 grams of Direct Black 19 dye. This solution is stirred for a~out 4 hours at room temperature and filtered through a .45 micron membrane filter. This ink pro-du~ed excellent water fast properties when printedon a wide variety of papers. The ink was applied by a ink ~et technique.
Example 2 Example 1 is repeated except that the ink composition 5 is formulated as follows:
Direct ~lack 19 Dye 8.0%
NH40H (30% solution) 4.5%
Carbowax 200 * 10.0%
H2O 77.5% 0 The results ohtained are similar to thoseof Example 1.
*Trade Mark ~i4~9~7 Example 3 Exa~ple 1 is repe~ted except that the ink composition is ~'ormul~ted as follows:
Direct Black 19 Dye ,5%
NH40H (30~ solution) .5%
Carbowax 20010.0%
H2O 89.0% ,, The results obtained are similar to those of Example 1.
Ex'ample 4 Example 1 i5 repeated except that the ink composition i~ formulated as follows;
Direct Black 38 Dye 3.25 NH40H C30% solution) 1.1%
Car~owax 200 10.0-~
H2O 85.65%
The results obt~ined are similar to those of Example 1.
EXample' 5 Exa~ple 1 is repeated except that the ink composition is formulated as ~ollows:
Amani;l-P Dye 3.25 (Am. Color & Chem.~
NH4OH (,30% solution~ 1.0%
Carbowax 200 10.0%
H2O 85.7S%
The results obtained are si~ilar to those of Example 1.
Example 6 Example 1 is repeated except that the ink composition contains about 3.25% Direct Black 19 dye; about 10~
Carbowax 200; about 4% N-methyl-2-pyrrolidone; about 0,1% sodium omadine; and 0.2~ ethylenediamine tetra-acetic acid, tetrasodium salt; and remainder deionized water and ammonium hydroxide to provide a pH of 10.2 The results obtained are similar to those o~ Example 1.
79~7 ~ 12-The dashed line on the ~raph shows the water resistance by Use of a spectrophotometer by measuring the absor-ban~e of material washed off of a pr~nted sheet ~ith water. As noted, the ink lost pract~cally nothing in the test.
Example 7 Example 6 is repeated except that about 0.15% of sodium hydroxide and .1 to .2% of sodium carbonate are employed in place of the ammonium hydroxide to proyide the s~lution w~th a pH of 10.2. The solid line in the graph shows the water resistance of this ink~ A compaxison of the results shown in the graph ~or the ~nk of this example and that of example 6 clearly shows a significant difference in water spill resistance of the two inks with that of the present invention clearly being superior.
The tests for examples 6 and 7 were conducted at a temperature of about 74F, relative humidity of about 39~, a jet diameter of about 1.29 mils, an ink drop diameter of 2.48 mils, alambda (distance between drops) of 6.10 mils; ~xequency of 100 kilohertz; pressure of 32.2 ps~, and matrix spacing of 4.2 mils.
LE979~020
To be suitable as an ink in ink jet printing systems~ the ink must possess a number of important characteristic~ or properties. For instance, the ink must have a viscosity suitable for providing the pro-per flow characteristics in the jet printing process.
Most ink jet printing inks have viscosities within the rangeof about 1 to about 10 centipoise at 75F
and preferably about 2 to about 6 centipoise at about 75F. Of course, depending on the particular config-urati~n of the des~red ink jet printing apparatus to be employed, the viscosity of a particular composition c~n vary somewhat.
Moreover, in view of the small orifice dia-meters of the nozzle employed, nozzle clogging can hecome ~ major concern. Therefore, an ink to be em-ployed in an ink jet printing operation cannot containparticulate m~terial which could clog the orifice of the nozzle. ~urthermore, the ink employed should not be one which would dry and plug the orifice when the system is not in operation. Another requirement for 1~79~)7 an ink jet printing ink is that it be electrically con~uct~Ve. The ink should also have a rel~tively fas~ drying time and sh~uld be resistant to smearing~
Since the ink should be resistant to smearing on the writing medium, the ink must ha~e the property of being readily absoxbèd into the writing medium.
At the present time, commercially available ànk jet co~pos~tions contain an organic resin bondîng agent to ix or bond the dye to the substrate. It has been believed that the use of a synthetic resin binder is necessary for such prupose. For instance, U.S.
Patent 4,136,076 to Daniels suggests an ink jet print-ing camposition where~y the permanence and adhesion to the target ~urface is improved by the presence of certain p~lymers which conta~n unesterified free carbonyl groups and certain multivalent metals to provide ~ cross~linking of the polymer. Daniels ~urther su~gests the use of certain volatile bases including ammonium hydroxide in order to render the polymers soluble in water or alcohol required by Daniels because of the presence of the polymer.
Moreover, U.S. Patent 3,891,581 to Argenio suggests a water dilutable transfer ink composition for use in flexographic and xotogravure heat transfer printing processes which contain a thermoplastic resin such as a polyester obtained by reacting a polyol partially esterified rosin with maleic anhydride and/or fumaric acid. These compositions can contain ammonium hydroxide. The ammonium hydroxide is present so that the composition has a pH of between about 8 and 9.
U.S. Patent 4,150!997 to Hayes also suggests the presence of cert~in bases to ink compositions con-taining a fluorescent pigment. The fluorescent pigment is a mixture of a dye ~nd an organic resin which ap-parently is cured (along theselines, see column 2, ~L1479~37 ~4-lin~s 2Q-23 and colu~n 3, lines 12 and 13), The base ~s ~dded to solubilize the pigment~ For in-stance, the base c~n be ammonium hydroxide which, according to the disclosure of this patent, forms a quaternary salt with the fluorescent pigment.
U.S. Patent 3,846,141 to Ostergren et al suggests jet printing ink compositions which can contain a base such ~s an alkanol a~ine, a monovalent hydrox-ide suchas an alkali metal hydroxide, ammonium hydrox~de or morpholine to provide a composition having a pH above ~bout 9. The base is disclosed as enabling the ink composition to be modi~ied by the incorporation of a resinous system such as a modi~ied styrene-maleic anhydride resln (see column 3, lines 53 et seq.l.
-U~S. Patent 3,594,736 to Hertz et al is of generalintere$t~
Disclosure of Invention The present invention, contrary to the suggestion in the prior art, does not require the presence of a resinous bonding agent in order to achieve water fastness of the dye. According to the present invention, the pH of the composition is ~djusted by incorporating ammonium hydroxide which maintains the dye dissolved while the ink is ln the bottle or ~1~7~7 ~ 5-container but evaporates after the ink is printed onto the substrate thereby reducing the pH and thereby rendering the ink insoluble on the paper, According to the present invention, a resinous binder is not necessary to achieve ~oth proper pH ~alance and water fastness as previously ~elieved.
The present inVention is concerned with an ink composition which consists essentially of an a~ueous solution o~ an organic direct dye and ammonium hydroxide, The ammonium hydroxide is present in the composition in an amount sufficient to provide the solution with a pH of at least about 9.5. In addi-t~on, the ~queous solution is free from resinous Binder components which are insoluble in water at a pH of ~bout 7 or less.
Brief ~escription of Drawing The drawing is a graph of water resistances of the inks of ~xamples 6 and 7.
Best and Various Modes ~or Carrying Out Invention According to the present invention, it is essential that the pH of the aqueous solution be provided by the addition of ammonium hydroxide as the basic material.
It has been noted, aswill be discussed hereinbelow, that the use of other basic materials such as sodium hydroxide and sodium carbonate have not provided the de~ree of water fastness achieved by the present in-vention when a synthetic resinous binder is not pre-sent in the composltion. Also, the addition of other volatile hases such as ammonium carbonate or morpholine does not provide the same desired results achieved with ~L1479~17 ~ 6~
ammonium hydroxide. The pH of the solution must be at least about 9.5 and is preferably at least about 10.
Generally the pH o~ the solution is not greater than ab~ut 12. The composition generally contains about ,05 to about 5% ~y ~eight of ammonium hydroxide and preferahly ~bout 0,1 to 3% ~y weight in order to achie~e the necessa~ pH level.
In addition~ the compos~tion must contain a coloring material which ts an ~rganic direct dye or mixture of such'dyes. The dyes employed should be soluble in water at a pH o~ a~out 9.5 and/or higher but substan-tially insoluble at a pH of 7 or less to achieve the ~esults obta,ined by the present invention. For in-stance, dyes such as Direct ~lue 1 and Direct Black 80 which Are soluble at a pH o~ 7 or belowdid not exhibit ~ater fastness when formulated with ammonium hydroxide ~ithout a xesinous bonding agent.
The use of pigments or other forms of particular matertal is not desirable since such materials tend to clog up the ~rery small orifices of the jet printer.
Preferred dyes of the present invention are the com-mercially available direct dyes which generally contain an ionizable inor~anic salt, such as Glauber salts, or sodium chloride which has been added during manufac-ture in order to standardize the dye lot. The inorganic~aterial thus renders the dye conducti~e whereby the ink drops are capable of b~ing deflected in an electro-magnetic field during jet printing. Such direct dyes are ~ell known to those skilled in the art and are commercially available, as represented by the CI Direct Black 38 dyes; Di~ect Black 19 dye; Amanil-P*dye;
.
~' , -- .
79V~7 Di~ect Blue 106; Direct Black 163; and Food Black 2.
A particularly pre~erred dye is Direct Black 19 dye.
It has been noted that Direct Black 19, Direct Black 38~ and ~m~nil-P dye have exhibited excellent water fast properties when employed with the ammonium hydrox~de. Howevex, var~ous other of the direct dyes, such as D~xect Blue 106, Direct Black 163, and Food Black 2 have been ~ormulated along with ammonium hydroxide but such, although exhibiting some degree of improved watex fastness, have not shown the excep-; tionally high degree ach~eved by the use of the above three-mentioned dyes.
The dye is generall~ present in the composition in amounts o~ about 0,5 to about 8% by ~eight, and preferahl~ ~bout 2 to about 5% ~y weight. In addition, it is noted that the water employed shbuld be distilled water which do~s not contain any substantial amounts of ions and can be considered deionized water.
The compositions can also contain auxiliary constituents such as humectants, bioc~des, fungicides, and stabil-izers or solubilizers.
Examples of some suitable humectants include gylcol and glycol derivatives, such as the polyalkylene glycols (such as polyethylene glycols and polypropylene glycols], propylene glycol, lower alkyl ethers of ethylene glycol, or diethylene glycol (such as ethylene glycol monomethyl-ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and ethylane glycol monobutyl ether); and glycerine. The humectant can generally be ~7~)7 pre~ent in the co~position, when employed, in a~ounts of ~out 5 to about 45% by weight. The hu~ectants are employed to retard the dxying of the inks to prevent prernature drying in the capillaries or other portions of the jet printing apparatus.
Examples of some solub~lizing agents to insure that the dye remains in solution include those mentioned in U.S~ Patent 3,846,141, such as N~methyl-2-pyrroli-done; ~ -dihydroxyethyl sulfide, N-vinyl pyrrolidone, substituted pyrrolidone, such as Solvofen HM-Gaf, 4-methoxy-4 methyl pentanone-2 and tetrahydro~
furfuryl alcohol. The a~ount of solubilizing agent generall~ employed is up to about 5% by weight andpreferably ~out 0.5 to about 4% by weight based upon the total weight o~ the ink composition.
Also, the ink composition may include a preservative to inhibit the irowth of bacteria during storage, particul~rly when the compositions are to be stored for prolonged periods of time. The bacteria might cloy the orifice of the jet printer if not prevented from growing. Examples of some suitabie preservatives are sodium omadine, and 6-acetoxy-2,4-dimethyl-m dioxane. Such are usually employed in amounts of up to about 1% by weight.
The composition ~ight also contain a chelating agent, such as ethylenedia~ine tetraacetic acid, tetra-sodium, generally xeferred to as EDTA. Chelating agents are employed for complexing metal ions such as ixon, Zinc, or magnesium present within the aqueous composition in order to prevent the precipitation of metal ions dissolved in the water or present along ~7907 witll the dye The chelating agent is generally employed in ~mounts up to about 5~ ~y weight and preferably abollt 0.05 to about 0.5% by wei~ht.
It is desirable that the compositions of the present invention have a viscosity of about 1.2 to about 10 centipoi~e at 75~ and prefera~ly about 2 to about 6 centipo~se at 75~F.
The compositions of the present invention can be pre-pared by thbroughly mixing the constituents to insure uniform mixin~ and complete dissolution of the dye and then ~ilter;~ng the resulting composition to remove any particulate contamination~ Filtration of the composition after mixing the components is highly desir~ble in oxder to remove from the composition particulate matter~ such as contamination or undissolved dye which mi~ht otherwise serve to clog or obstruct the oxifices of a jet prlnter during use. It is gen-erally pre~erred to filter the compositions of the present invertion in order to remove particulate matter having a diameter greater than about 2 microns, and preferably greater than about 1 micron in order to insure that the obstruction o~ the jet printed ~ill be avoided.
In accordance with the preferred method of preparing t~e compositions of the present invention, the water vehicle, a~monium hydroxide, any humectants, if present, and any solubilizing agent~ if employed, are first thoroughtly mixed in a manner in which the introduc-tion of air into the mixture or foaming is substantially avoided. After ~ uniform mlxture is obtained, the preserVative~ i~ employed~isslowly added and mixing LE979~020 :~147907 .`10-i5 continued until ~ unifo~m mixture is obtained.
Afte~ this, the oxganic dye is slowly sifted into the re~ulting mixture ~hile~a~itation is continued to en ure substantially complete dissolution of the dye S in the aqueous solution~ After dissolution of the dye, the ink composition is filtered to remove any particulate ~atter contained therein having a size greater th~n the desired maximum particle size.
The following non~limiting examples are presented wherein amounts are by weight unless the contrary is stated.
Example 1 To about 857.5 grams of deionized water at 72~F are added w~th stirring about 10 grams of a 30% solution lS of ammonium hydroxide; about 100 grams of Carbowax*200 (i.e. poLyethylene glycol); and about 32.5 grams of Direct Black 19 dye. This solution is stirred for a~out 4 hours at room temperature and filtered through a .45 micron membrane filter. This ink pro-du~ed excellent water fast properties when printedon a wide variety of papers. The ink was applied by a ink ~et technique.
Example 2 Example 1 is repeated except that the ink composition 5 is formulated as follows:
Direct ~lack 19 Dye 8.0%
NH40H (30% solution) 4.5%
Carbowax 200 * 10.0%
H2O 77.5% 0 The results ohtained are similar to thoseof Example 1.
*Trade Mark ~i4~9~7 Example 3 Exa~ple 1 is repe~ted except that the ink composition is ~'ormul~ted as follows:
Direct Black 19 Dye ,5%
NH40H (30~ solution) .5%
Carbowax 20010.0%
H2O 89.0% ,, The results obtained are similar to those of Example 1.
Ex'ample 4 Example 1 i5 repeated except that the ink composition i~ formulated as follows;
Direct Black 38 Dye 3.25 NH40H C30% solution) 1.1%
Car~owax 200 10.0-~
H2O 85.65%
The results obt~ined are similar to those of Example 1.
EXample' 5 Exa~ple 1 is repeated except that the ink composition is formulated as ~ollows:
Amani;l-P Dye 3.25 (Am. Color & Chem.~
NH4OH (,30% solution~ 1.0%
Carbowax 200 10.0%
H2O 85.7S%
The results obtained are si~ilar to those of Example 1.
Example 6 Example 1 is repeated except that the ink composition contains about 3.25% Direct Black 19 dye; about 10~
Carbowax 200; about 4% N-methyl-2-pyrrolidone; about 0,1% sodium omadine; and 0.2~ ethylenediamine tetra-acetic acid, tetrasodium salt; and remainder deionized water and ammonium hydroxide to provide a pH of 10.2 The results obtained are similar to those o~ Example 1.
79~7 ~ 12-The dashed line on the ~raph shows the water resistance by Use of a spectrophotometer by measuring the absor-ban~e of material washed off of a pr~nted sheet ~ith water. As noted, the ink lost pract~cally nothing in the test.
Example 7 Example 6 is repeated except that about 0.15% of sodium hydroxide and .1 to .2% of sodium carbonate are employed in place of the ammonium hydroxide to proyide the s~lution w~th a pH of 10.2. The solid line in the graph shows the water resistance of this ink~ A compaxison of the results shown in the graph ~or the ~nk of this example and that of example 6 clearly shows a significant difference in water spill resistance of the two inks with that of the present invention clearly being superior.
The tests for examples 6 and 7 were conducted at a temperature of about 74F, relative humidity of about 39~, a jet diameter of about 1.29 mils, an ink drop diameter of 2.48 mils, alambda (distance between drops) of 6.10 mils; ~xequency of 100 kilohertz; pressure of 32.2 ps~, and matrix spacing of 4.2 mils.
LE979~020
Claims (24)
1. An ink composition suitable for use in ink jet printers exhibiting suitable viscosity and water-fastness comprising an aqueous solution of (a) water (b) an organic direct dye soluble in water at a pH of about 9.5 or higher but being substantially insolu-ble in water at a pH of 7 or less;
(c) ammonium hydroxide in suitable concentration to attain a pH of about 9.5 or higher;
said ink composition being substantially free of all resinous binders.
(c) ammonium hydroxide in suitable concentration to attain a pH of about 9.5 or higher;
said ink composition being substantially free of all resinous binders.
2. The ink composition of claim 1 having a pH of between about 9.5 and 12.
3. The ink composition of claim 2 including about 0.5 to about 8% by weight of said dye.
4. The ink composition of claim 3 including a humectant.
5. The ink composition of claim 1 including about 2% to about 5% by weight Direct Black 19 dye and about 10% by weight of polyethylene glycol said ink composition having sufficient ammonium hydroxide to produce a pH of about 10 .
6. The ink composition of claim 1 wherein said pH is at least about 10.
7. The ink composition of claim 1 wherein said pH is no greater than about 12.
8. The ink composition of claim 1 wherein the amount of ammonium hydroxide is about 0.05 to about 5% by weight.
9. The ink composition of claim 1 wherein the amount of ammonium hydroxide is about 0.1 to about 3% by weight.
10. The ink composition of claim 1 wherein said dye is Direct Black 38 dye.
11. The ink composition of claim 1 wherein said dye is Direct Black 19 dye.
12. The ink composition of claim 1 wherein said dye is Amanil-P* dye.
13. The ink composition of claim 1 which contains about 0.5 to about 8% by weight of said dye.
14. The ink composition of claim 1 which further contains a humectant.
15. The ink composition of claim 14 wherein said humec-tant is a glycol or polyalkylene glycol or mixture thereof.
16. The ink composition of claim 14 wherein said humectant is present in amounts of about 5 to about 45% by weight.
17. The ink composition of claim 1 which contains up to about 5% by weight of a solubilizing agent.
18. The ink composition of claim 17 wherein said solu-bilizing agent is present in an amount of about 0.5 to about 4% by weight.
19. The ink composition of claim 13 wherein said solu-bilizing agent is N-methyl-2-pyrrolidone.
20. The ink composition of claim 1 which further con-tains a preservative.
21. The ink composition of claim 1 which contains about 0.05 to about 0.5% by weight of a chelating agent.
22. The ink composition of claim 21 wherein said chelat-ing agent is ethylenediamine tetraacetic acid, tetrasodium.
23. The ink composition of claim 1 wherein the viscosity is about 1.2 to about 10 centipoise at 75°F.
24. The ink composition of claim 1 wherein the viscosity is about 2 to about 6 centipoise at 75°F.
*Trade Mark
*Trade Mark
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US9225479A | 1979-11-07 | 1979-11-07 | |
| US092,254 | 1979-11-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1147907A true CA1147907A (en) | 1983-06-14 |
Family
ID=22232389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000360331A Expired CA1147907A (en) | 1979-11-07 | 1980-09-16 | Water-based ink composition |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0028720B1 (en) |
| JP (1) | JPS5676475A (en) |
| CA (1) | CA1147907A (en) |
| DE (1) | DE3065786D1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU668260B2 (en) * | 1993-01-25 | 1996-04-26 | Canon Kabushiki Kaisha | Recording paper and ink-jet recording process making use of the same |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1195810B (en) * | 1981-10-05 | 1988-10-27 | Olivetti & Co Spa | SELECTIVE JET WRITING DEVICE OF RELATIVE INK IN CHOISTRO AND INK PREPARATION PROCESS |
| US4557761A (en) * | 1982-12-01 | 1985-12-10 | Canon Kabushiki Kaisha | Recording liquid |
| US4601756A (en) * | 1983-10-19 | 1986-07-22 | Canon Kabushiki Kaisha | Recording liquid |
| US4624708A (en) * | 1985-04-15 | 1986-11-25 | Xerox Corporation | Sulfonated trisazo dyes for ink jet compositions |
| EP0660805B1 (en) * | 1992-09-17 | 2001-11-21 | Coates Lorilleux S.A. | Method of cleaning waste water and recovery of contaminants therefrom |
| JP3072817B2 (en) | 1993-11-04 | 2000-08-07 | キヤノン株式会社 | Recording paper, image forming method using the same, and method of manufacturing recording paper |
| WO2015016295A1 (en) * | 2013-07-31 | 2015-02-05 | 中外製薬株式会社 | Pharmaceutical preparation comprising aminopyrazole derivative |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51137506A (en) * | 1975-05-22 | 1976-11-27 | Konishiroku Photo Ind | Composition of ink for ink jet recording |
| GB1526017A (en) * | 1975-12-05 | 1978-09-27 | Dainippon Toryo Kk | Ink composition for ink jet recording |
| JPS53123208A (en) * | 1977-04-02 | 1978-10-27 | Dainippon Toryo Kk | Aqueous marking ink |
| US4136076A (en) * | 1977-10-25 | 1979-01-23 | Dennison Manufacturing Co. | Ink jet printing composition comprising a solvent, a dye stuff, a volatile base, a multi-valent metal and a polymer containing carboxyl groups |
| US4155768A (en) * | 1977-12-05 | 1979-05-22 | International Business Machines Corporation | Waterfast ink for use in ink jet printing |
-
1980
- 1980-09-16 CA CA000360331A patent/CA1147907A/en not_active Expired
- 1980-10-15 DE DE8080106258T patent/DE3065786D1/en not_active Expired
- 1980-10-15 EP EP19800106258 patent/EP0028720B1/en not_active Expired
- 1980-10-29 JP JP15087480A patent/JPS5676475A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU668260B2 (en) * | 1993-01-25 | 1996-04-26 | Canon Kabushiki Kaisha | Recording paper and ink-jet recording process making use of the same |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3065786D1 (en) | 1984-01-05 |
| JPS5676475A (en) | 1981-06-24 |
| EP0028720A1 (en) | 1981-05-20 |
| EP0028720B1 (en) | 1983-11-30 |
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