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
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
  • C09D11/102—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds
• • 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
  • C09D11/02—Printing inks
  • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
• • 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
  • C09D11/02—Printing inks
  • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
  • C09D11/037—Printing inks characterised by features other than the chemical nature of the binder characterised by the pigment

Definitions

• This invention relates generally to an ink composition, and in particular to a publication gravure ink containing a polyurethane bound colorant.
• the metal cylinder is used to transfer ink to paper.
• the depth ofthe engraving determines the amount of ink which is picked up by the rotating cylinder, and in turn, determines
• the number of cells may range from 22,000 cells per inch for standard quality printing, to 32,000 cells per inch or more
• Each individual cell is from 20 to 200 microns in width.
• the inks used in publication gravure consists of a colorant and a liquid vehicle
• a binder present in the vehicle affixes the colorant to the substrate on which it is printed.
• the binder may be a drying oil, which oxidizes and is converted from a liquid to a solid film,
• Gravure inks consist of approximately 30 wt. % of non- volatile components
• the binder and colorant are typically present in a ratio ranging from about 5: 1 to about 1 : 1 by weight, respectively.
• the resolution of gravure printing may be improved by increasing the number of
• pigments are employed as colorants in the inks.
• the pigments are
• resins such as polyurethane bound colorants
• resins may be substituted for conventional pigments.
• polymers can be ground to very fine powders and dispersed in inks or coating compositions.
• Moore et al., U.S. 5,176,745 disclose poly(oxyalkylene) substituted
• an object ofthe invention is to provide a gravure ink with increased color strength.
• Another object ofthe invention is to provide a gravure ink with reduced non-volatile components (solids) content, without sacrificing color strength. Still
• Another object ofthe invention is to replace all or part ofthe binder in a conventional
• the invention is to provide a gravure printing process employing the novel gravure ink disclosed herein.
• an ink composition having a volatile solvent and a non ⁇ volatile, film forming component, with the improvement of a colored polyurethane oligomer included in the non-volatile component, wherein the colored polyurethane oligomer is dissolved in the volatile solvent.
• the present gravure ink composition has the advantage of being compatible with higher resolution engraved cylinders, which employ relatively shallow cells, and can
• the present ink composition allows for improved color utilization and low solids compositions, which reduces ink
• the colored polyurethane oligomer can be employed as a binder in combination with pigments to enhance color strength.
• the gravure ink composition and its use in publication gravure printing has one or more ofthe following features: meets commercial viscosity requirements at relatively low solids content; reduced film thickness; greater color strength; improved rub resistance;
• C and molecular weights are based on the arithmetic mean.
• aryl and arylene are intended to be limited to single and fused double ring aromatic hydrocarbons. Unless otherwise specified, aliphatic hydrocarbons are from 1 to 12 carbon atoms in length, and cycloaliphatic hydrocarbons comprise from 3 to 8
• the ink composition contains approximately 5 to 40 wt. % solids and about 60 to 95 wt. % volatile solvent.
• the solids may be dispersed in the ink or dissolved in »
• non-volatile component is used herein to describe compounds which are left on the substrate, usually paper, when the ink dries during conventional publication gravure printing.
• the volatile solvent in the ink composition is preferably an organic solvent.
• the organic solvent may be selected from aliphatic, naphthenic and
• organic solvents include:
• esters of aliphatic acid having a boiling point from 60 to 340° C; (iii) esters of aliphatic acid having a boiling point
• ketones having a boiling point from 75 to 180° C;
• the organic solvents are C 3 to C 40 , compounds.
• organic solvents include
• ink compositions which contain emulsions of water and organic solvent, such as disclosed in Batlaw et al, U.S. 5,389,130.
• the solids component contains a polyurethane oligomer having copolymerized
• a polyfunctional chromophore referred hereto in as a "colored polyurethane oligomer".
• the colored polyurethane oligomer replaces all or a portion ofthe binder, or the binder and colorant in a conventional gravure ink composition.
• the colored polyurethane oligomers ofthe present invention may be prepared by
• mixture includes a polyol.
• Catalysts such as tertiary amines and organometallic
• Crosslinking ofthe polyurethane oligomer is preferably minimized by selecting a
• diisocyanate or polyisocyanate having a NCO number of from 2.0 to 2.5, preferably 2.0
• Suitable diisocyanates include: 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, mixtures of 2,4- and 2,6-tolylene diisocyanate, 4,4'-biphenylene
• 2,4'- diphenylmethane diisocyante tetramethyl-m-xylene diisocyanate, p-xylene diisocyanate, methylenedi-p-phenyl diisocyanate, m-phenylene diisocyanate, p-phenylene diisocanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-
• diisocyanatodiphenyl ether bis(4-isocyanatophenyl)sulfone, isopropylidene bis(4-phenyl
• isocyanate naphthalene- 1,5-diisocyanate, l-chloro-2,4-phenylene diisocyanate, 3,3'- bitolylene-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro- 4,4'-biphenylene diisocyanate, 2,2',5,5'-tetramethyl-4,4'- biphenylene diisocyanate, diphenylethane-4,4'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and the like.
• the colorant is preferably difunctional and the nucleophilic functionalities are preferably hydroxy.
• Virtually any chromophore may be employed in the invention,
• azo including polyazo, diphenylmethane,
• triarylmethane including polymethine, acridene, quinoline, thiazole, indamine, indophenol, azine, oxazine, thiazine, anthraquinone, indigoid and
• phthalocyanine chromophores are azos, diphenymethanes, triarylmethanes, xanthenes, methines, anthraquinones and phthalocyanines. S96/19957
• Example of suitable colorants include those having a nucleophilic group bonded
• oligomer one may employ: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-
• x represents 3, 4, or 5; and diols containing one or more oxygen or sulfur atoms in the chain, e.g., diethylene glycol, 2,2'-thiodiethanol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,3- and
• the greatest color strength will be achieved when the nucleophilic component of the polyurethane oligomer is primarily made up of functionalized colorant molecules.
• polyurethane oligomer by including a molar ratio of colorant to uncolored polyol
• the colorant compounds comprise greater than 50 mole percent of
• Colored polyurethane oligomers having the following characteristics are preferred: soluble in toluene, xylene and/or RotosolveTM at a concentration of at least 30 part per 100 parts of solvent;
• the molecular weight ranges from 2,000 to 15,000.
• the non- volatile or solids component ofthe ink composition may also contain conventional colorants and binders
• the most important class of colorants is pigments, and their use in gravure ink
• compositions is well known to those skilled in the art.
• compositions are well known to those skilled in the art.
• white pigments for purposes ofthe description herein, white pigments, clays, opacifiers and
• pigments are classified as pigments.
• dyestuffs are also within the scope ofthe present invention.
• Suitable dyestufFs are also present.
• Acid Dyes such as Acid Red 87, C.I. Number 45380
• Basic Dyes such as Basic Violet 10, C.I. Number 45170, and Basic Blue 26, C.I. Number 44045
• Solvent Dyes such as Solvent Yellow 19, C.I. Number 13900: 1 and
• binders are resins described as solid materials, or liquids ofa relatively high molecular weight, which adhere the colorant to a substrate when the ink dries.
• rosin and modified rosins such as calcium, magnesium and zinc metallic resinates, ester gum of rosin, maleic resins and esters, dimerized and
• polymerized rosins and rosin modified fumaric resins shellac, asphalts, phenolic resins and rosin-modified phenolic resins; alkyd resins; polystyrene resins and
• copolymers thereof terpene resins; alkylated urea formaldehyde resins; alkylated melamine formaldehyde resins; polyamide resins; vinyl resins, such as polyvinyl
• ketone resins acrylic resins, such as polyacryhc acid and polymethacrylic acid; epoxide resins; polyurethane resins; cellulosic resins, such as nitro cellulose, ethyl cellulose, cellulose acetate butyrate and carboxymethyl cellulose.
• the formulation may also include a non-drying oil like Maggie Oil 52TM, or a semi-drying oil or drying oil, such as linseed oil, tung oil and oiticica oil, as a binder. These oils undergo oxidative polymerization upon drying to form an adhesive film for
• these oils are provided in a modified form to enhance their
• Modification generally includes heat polymerization to form cyclic, dimers, trimers and some higher order polymers.
• Viscosities of these modified oils generally range from 1000 to 7500 centipoise at 25° C and they have a density of about 0.94 to 0.98 grams per ml. It is also well known in the art to incorporate miscellaneous additives into the ink composition to enhance performance with regard to gloss, rub resistance, flexibility,
• sucrose acetate iso-butyrate such as sucrose acetate iso-butyrate, triethyl citrate, and epoxidized soy bean oil, and
• waxes such as polyethylene waxes, halogenated hydrocarbon waxes and fatty acid amides.
• additives such as surfactants, defoaming agents, catalysts,
• the solids component ofthe ink may contain from: 0.1 to 100 parts of a colored polyurethane oligomers
• the colored polyurethane oligomer is at least 25%
• the solids component ofthe ink composition may contain from:
• An advantage of incorporating a colored polyurethane oligomer into a gravure ink is that the weight percent solids in the ink composition can be reduced, without
• Such inks form very thin films and are resistant to skip dots in light end print out, which
• drying in may be caused by high viscosity or excessive solvent evaporation, referred to as "drying in”.
• drying in The reduced solids content ink generally results in printing having reduced film
• polyurethane oligomer translates into a significant material cost savings, since a solvent
• the viscosity ofthe ink composition when used for gravure printing is generally between 10 seconds and 30 seconds by Shell Cup #2, preferably between 14 seconds
• the Shell Cup is a vessel of standard volume with an orifice at the bottom.
• the time it takes for the ink to empty out is measured in seconds; the longer the time,
• inks are typically used at temperatures ranging from 20°
• the ink composition ofthe present invention is intended for use in conventional gravure printing.
• the process entails an engraved gravure roll which is
• a substrate such as paper
• a substrate is fed through a nip formed by an impression roller and the gravure roll, thereby transferring ink from the cell to the
• Print density was measured on the 100% tone scale with an X-RiteTM model 938 Spectrodensitometer using ANSI status T response. Print gloss was measured with a
• Example 1 The following examples demonstrate synthesis of a colored polyurethane oligomer from a poly(oxyalkylene) substituted yellow azo colorant, and formulation of
• the reaction mixture was cooled to 45°C and 25 parts of toluene and 8.8 parts of a mixture of 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane diisocyanate (Miles Mondur ® ML) were added.
• the ratio of 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane diisocyanate Miles Mondur ® ML
• isocyanate groups to hydroxyl groups was 1.0.
• the mixture was heated at 85°C until all ofthe isocyanate had reacted to give 94.0 parts of a yellow polyurethane oligomer solution in toluene with 73.4% solids.
• a yellow ink was made from the polyurethane oligomer by dissolving 1.0 part
• oligomer from a poly(oxyalkylene) substituted yellow methine colorant and formulation of a gravure ink.
• m-toluidine was reacted with 2 moles of ethylene oxide and 8 moles of propylene oxide. Then, the m-toluidine derivative was converted to p-formyl m-toluidine as described in U.S. Patent 4,658,064. The aldehyde was condensed with
• a gravure ink was made by combining 1 0 parts ofthe methine polyurethane oligomer, 0.52 parts Union Camp Unirez 1144 ® resins and 7 2 parts toluene to give a Shell Cup #1 viscosity of 18s and 17.6 wt % solids
• the following example demonstrates synthesis of a colored polyurethane oligomer from a poly(oxyalkylene) substituted blue triphenyl methane colorant, and formulation of a gravure ink
• N-methyl aniline was reacted with 1 mole of ethylene oxide and 10 moles of
• oligomer which incorporates a colorless diol, as well as a colorant, and formulation of a
• the colorant was a poly(oxyalkylene) substituted methine colorant made according to Example 6, except that instead ofthe m-toluidine intermediate, aniline
• a gravure ink was made by combining 1.0 parts ofthe colored polyurethane
• Example 8 0.52 39.2
• the results demonstrate that at various print densities, the gravure inks ofthe present invention meet commercial requirements for viscosity and gloss. Additionally, the degree of cohesion or adhesion ofthe printed ink films (blocking) was measured by
• Example 10 (Comparative) The following comparative examples demonstrate that gravure inks containing a
• Resinall FP927 phenolic resin (50% solids), 0.30 g Alcolec S lecithin surfactant and
• Ink B Comparing the pigment Ink A with the soluble polyurethane oligomer Ink B, one finds that Ink B used 94% less resin and 71% more toluene. With pigments, it is necessary to use resins during dispersion to keep the particles separated. Pigments do
• the polyurethane oligomers are soluble and do not require dispersants.
• the polyurethane oligomers have both color and resin properties.
• Inks A and B were applied to 34 lb. coated paper using a laboratory K-proofer
• the printed paper samples were analyzed using CIELab coordinates measured using an X-Rite model 938 Spectrodensitometer. The spectrodensitometer was adjusted to D65 illuminant and 10° viewer.
• the L, a * and b * color coordinates for the different paper samples are given in Table 4 below where L is a measure of lightness or darkness, a * is a measure of redness or greenness, and b * is a measure of yellowness or
• samples were folded ink side to ink side and were rubbed vigorously by hand for 5 s.
• the samples were rated from 1 to 5 where a rating of 1 corresponded to essentially complete removal ofthe ink film and a rating of 5 corresponded to no damage to the
• rub resistance improved as the concentration of colored polyurethane oligomer increased.
• colored with pigments can be increased by employing the colored polyurethane oligomer as a dispersant/binder in the ink composition.
• polyurethane oligomer of Example 1 50.0% solids
• 90.6 grams colored polyurethane oligomer of Example 6 64.6% solids
• 135.3 grams of toluene were added to an Eiger mill and dispersed at 5000 rpm for 10 minutes to give maximum particle size ⁇ 1.0 micron by Hegmann gage.
• the amount of Yellow 12 and 14 pigment in the ink ofthe present example is the same as in Ink A of Example 10.
• the ink ofthe present example was applied to 34 lb. coated paper using a laboratory K-proofer draw down plate.
• the print sample was overcoated with clear resin (Unirez 1144).
• the print results are summarized in Table 6.
• polyurethane colorant polymers can replace some ofthe clear resin used to disperse pigments resulting in greater print density.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 1996
  • 1996-01-05 US US08/583,870 patent/US5886091A/en not_active Expired - Lifetime
  • 1996-12-17 EP EP96944380A patent/EP0813579B1/en not_active Expired - Lifetime
  • 1996-12-17 DE DE69611160T patent/DE69611160T2/de not_active Expired - Fee Related
  • 1996-12-17 AU AU14203/97A patent/AU1420397A/en not_active Abandoned
  • 1996-12-17 JP JP9525212A patent/JPH11501980A/ja not_active Withdrawn
  • 1996-12-17 ES ES96944380T patent/ES2153997T3/es not_active Expired - Lifetime
  • 1996-12-17 WO PCT/US1996/019957 patent/WO1997025384A1/en not_active Ceased
• 1998
  • 1998-12-10 US US09/208,882 patent/US5973062A/en not_active Expired - Fee Related

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