WO2008045352A1

WO2008045352A1 - Printing inks and process for replacing paint colors utilizing paint colorant pigments

Info

Publication number: WO2008045352A1
Application number: PCT/US2007/021446
Authority: WO
Inventors: Daniel G. Phillips; Britt Nordby; Deokumar Robert Brijlall
Original assignee: Evonik Degussa Corporation
Priority date: 2006-10-06
Filing date: 2007-10-05
Publication date: 2008-04-17

Abstract

Custom printed retail paint merchandising aids, such as color cards having one or more color schemes displayed in predetermined fields for use in selecting custom-mixed architectural coating colors are produced to provide colors reproduced with great accuracy on an inkjet printer that is supplied with an ink color pigment dispersion set formulated with up to sixteen different colored liquid inks, each of which liquid inks are formulated from ink pigment dispersions using the same type of pigments as the corresponding paint pigment dispersions used to custom tint the finished architectural surface coating.

Description

PRINTING INKS AND PROCESS FOR REPLACING PAINT COLORS UTILIZING PAINT COLORANT PIGMENTS

Field of the Invention

This invention relates to pigment dispersions and printing inks formulated from these pigment dispersions that are particularly useful for the printing of improved, non-metameric representations of paint colors for use in the selection and identification of architectural surface coatings and paints. Specifically, the color dispersions and formulations are useful in inkjet printers that are programmed to replicate a predetermined color or group of colors selected from a larger pallet of colors.

Background of the Invention

Retail paint purchasers, including the class of non-professional do-it-yourself painters and professional painters and contractors, are accustomed to selecting custom-mixed colors from a pallet consisting of from several hundred to over twenty-seven hundred colors, shades and tones.

It has been, and remains the custom in the trade to display sample paint color cards, sometimes referred to as color chips_> at the point of sale, and to make these color cards available to the prospective customer. The traditional color cards typically take the form of strips of paper on which are coated stripes of color. These color cards have heretofore been prepared using a mixture formulated as paint which is then deposited onto a large substrate in the form of a moving web. It should be noted that the paint used in preparing color cards is not the same as the architectural paint whose color choices are intended to be displayed. This difference in paints is necessitated by the process used to create color chips and other sales aids. The substrates are dried and then cut into the desired size of color card, then selected by the user with no direct application to an architectural image or model.

In the United States, colorant systems for tinting architectural coatings have been developed that are based on twelve (12) pigment dispersions. Automated mechanical systems are provided with twelve (12) canisters in which the twelve (12) pigment dispersions are stored for automated dispensing into, for example, quart and gallon containers of paint base. In Europe and other regions of the world, custom-tinting systems have been developed that are based upon up to sixteen (16) colorants. Again, appropriate automated dispensing apparatus provide canisters and computer-controlled precision pumps and valves to accurately dispense one or a number of predetermined colorants into the container of paint base in order to produce the color selected by the customer.

Color cards are also produced to correspond to the types of paint available in the system. As used herein, references to types of paint means flat, eggshell, semi-gloss, gloss and other similar terms corresponding to the surface reflectivity of the finished dried paint. Traditionally, the art has accepted color cards that are, at most, a few inches wide, with paint stripes or "chips" that are much smaller. The advantages of offering larger color sample displays is apparent from a practical and marketing standpoint.

It has become acceptable and even desirable in various retail and commercial sales facilities engaged in the sales of end products of various colors to provide electronic color visualizers to permit the perspective purchaser to undertake color sampling independently of a sales representative. The important goal of achieving customer satisfaction with the color of the end product based upon a selection made utilizing an electronic means such as a computer monitor or larger scale touch screen display is the accuracy of the color portrayal. In order to attract and assist prospective purchases of custom -mixed architectural coatings and other paiαts, interactive computer-based programs have been developed. These electronic systems are offered in place of, or to supplement the pre-printed color cards or chips.

The electronic selection and display system can also include an associated inkjet printer to provide facsimiles of the screen displays or simpler color cards. The printers used in producing these color cards, or printed merchandising aides, are standard four-color inkjet printers. These will be understood by one of ordinary skill in the art of color reproduction in the field of architectural coatings to represent an approximation of the full range of colors obtainable by custom-mixing paints using ten or more standard colorants. The accurate representation or replication of colors on a printable substrate that are intended to correspond to those of an architectural surface coating when applied to a wall or other architectural element is, at best, problematical. This is particularly true when a color system having in excess of 2,500 separate tints and shades is being offered by the paint retailer.

Thus, a system using a four-color printer to produce color cards and color scheme combinations to support the sales of custom-tinted paints is necessarily limited. Customer satisfaction, and therefore prospective brand loyalty, depends to a great extent upon the customer's determination that the color field portrayed on the color card is an accurate representation of the color of the finished architectural coating when applied to a wall or other element. The long-established practice of providing a rack containing an organized display of relatively small color cards, each of which typically contains two or more color chips is being continued by retailers. Prospective customers can take the color cards home to assist in their fϊnal selection of the custom-mixed color(s). It is the current practice to manufacture these color cards and chips by applying a paint mixture directly to the paper substrate. The manufacture, original stocking and subsequent restocking of display racks and providing other types of printed merchandising aids is an expense that is associated with the retail sale of paint.

Therefore, the ability to customize and preview a selection of paint colors to be applied to the walls, trim and other features of a house, interior room or other architectural structure by means of custom printed cards and the like has been limited, resulting in unsatisfactory choices and increased expense to apply a color scheme with which the user ultimately may not be pleased.

Some improvement in reproducibility and the delineation of subtle differences between shades and tints of varying colors in a large palette can be expected by increasing the number of jets used for printing. Six-color and eight-color iπkjet printers have been developed for various commercial applications, principally the production of large volume products, such as outdoor billboards and other display items printed on flexible fabric-like substrates. However, in all of these various systems of the prior art, the colors to be reproduced are applied to the substrate in the form of inks. With the exception of black, magenta and yellow inks, the materials used to produce colored inks are different from, and for the most part, are chemically and functionally unrelated to those used to produce pigment dispersions or colorants that are used to custom-tint paint bases.

It is therefore an object of the invention to provide an improved printing system, including novel pigment dispersions and formulations for colored inks to provide more accurate representations of finished architectural coatings and paints when printed on flexible substrates of paper or the like.

Another object of the invention is to provide a new class of specialized printing inks that correspond to the colors of pigment dispersions used in the custom tinting of various types of paint bases. A further object of the invention is to provide methods for preparing printing ink formulations using pigments that are the same class and type of pigments used in producing pigment dispersions employed in custom tinting architectural coatings and paints.

Summary of the Invention

In one aspect, the invention broadly comprehends providing a specially formulated ink color pigment dispersion set for producing inks, which set includes pigment dispersions that are based on pigments used in existing custom tinting systems for architectural coatings and paints that are in commercial use.

A computer-based color selection and display system and method allow a user to make numerous color selections and to assemble color schemes that are reproduced on a printing substrate by a "paint-jef ' system. As used herein, the terms "paint-jet" system and "paint-jet" printer refer to the use of pigment dispersions, or colorants, to formulate inks that contain the same pigments as the commercial colorants that are commonly used to custom tint architectural coatings that are commonly referred to as interior and exterior house paint. The specially formulated ink, prepared in accordance with the invention, are used in a print head, nozzles and a corresponding control system that is analogous to an inkjet printer. These paint-jet compositions replace and supplement the conventional ink formulations used in inkjet printers. The use of the ink sets of the invention permit the accurate reproduction of the corresponding palette of paint colors for printing on demand by a prospective purchaser.

As used herein, the terms architectural coatings, architectural finishes and paint are used interchangeably. These terms refer to compositions prepared by mixing a pigment dispersion, (or colorant dispersion, or simply a colorant) in a paint base, which base can be clear or contain predetermined concentrations of titanium dioxide (TiO_>) in order to produce a desired color.

As used herein the term "pigmenf ' means an inorganic mineral compound or organic compound of a given color that is processed, e.g., as by grinding, and mixed with one or more liquid additives to produce a pigment dispersion, or colorant, of a specified color. For the purpose of describing the present invention, a set of paint pigment dispersions consisting of from as few as four (4) and up to sixteen (16) different colorants are used to produce an unlimited palette of different architectural surface coating (paint) colors. The present invention comprehends a corresponding set of inks prepared from specially formulated ink pigment dispersions, each of which dispersions employs the same type of pigment as the corresponding color of paint pigment dispersion. In the interests of clarity and to facilitate the description of the invention, the terms "ink pigment dispersion(s)" or "ink colorant(s)" will be used with reference to the preparation of the novel inks for use in inkjet printers, and "paint pigment dispersion(s)" or "paint colorants" will be used with reference to the prior art products used in tinting architectural surface coatings, or wall paint, in accordance with a given formula, or recipe, to achieve a predetermined color for the applied paint.

As used herein, the term "color ink set" means a plurality of predetermined inks of different colors that are produced using the same pigments as a corresponding set of paint colorants. The set of pigment dispersions and resulting ink formulations for use in the paint-jet system can comprise as few as four specially formulated inks, and is preferably based on eight to ten inks, more preferably on twelve inks, and most preferably on sixteen inks of different color, or color intensity. As used herein, the terms "color card" and "color sample card" will be understood to mean substrates upon which one or more colors are printed in variously configured fields, or color schemes, including depictions of rooms and building exteriors. Colorant Printing Formulations As previously noted, a limited number of printing inks employ the same pigments that are utilized in formulating pigment dispersions, or colorants, for architectural surface coatings. These include black, based upon carbon black, magenta and yellow. The cyan blue pigments traditionally used in formulating inks for conventional inkjet printers are different than the pigment(s) used to produce colorant dispersions for tinting paints. It has been found that using the same pigments that are used to produce the colorants for paints to produce the pigment dispersions for use in the manufacture of inks for use in an inkjet printer results in a greater ability to more accurately and reliably reproduce a given paint color on a printed merchandising aid.

Printing ink colorant dispersions for producing inks for use in the paint-jet printing method and apparatus of the invention can be produced from the following pigment types: a. black from carbon black PBk 7, b. magenta from ?V 19, c. yellow from PY74, d. blue from PBl 15 group, including 15:2, 15:3, e. green from PG7, f. red from PRl 88, g. yellow from PY42, h. yellow from a PY74 / PY65 mix, i. red from PRlOl₅ j. light black from PBk7, k. white from PWl.

It will be understood from the above description and discussion of the prior art, the system of the present invention will correspond in the number of individual colorants for the printing of merchandising aids to the number of colorant dispersions employed in the paint tinting system. Thus, for use with existing sixteen (16) pigment dispersion dispensing systems for custom mixing of paints, the paint-jet printer will have sixteen (16) dispensing jet nozzles. In the practical application of the system of the invention, a printer with twelve (12) inkjets would meet the needs of the industry. In most applications, the number of inkjets can be reduced by relying on the white background of the paper printing substrate to eliminate the need for a white colorant Preferred paper substrates are discussed below. Printers having six (6), eight (8) or ten (10) print heads can be utilized in the system and method of the invention. Shades of gray can also be achieved by using lower levels of black ink pigment dispersion in accordance with known program/controller methods.

Commercially acceptable printed merchandising aids can be produced using the paint- jet printing system of the invention that incorporates ten (10) different colored inks. InkJet printers with ten-color capability are commercially available. If an existing commercial inkjet printer is to be adapted for use with the invention, it should be of the type that utilizes pigmented-based inks rather than dyes. Since existing 10-color printers typically include cartridges containing several shades of black ink, the printer driver must be reprogrammed. Ηie design and implementation of the appropriate control system is well within the ordinary skill in the art.

In one preferred embodiment of the invention, the printing colorants are stored in refillable and interchangeable plastic reservoirs and connected by flexible plastic feed tubes to the inlet ports of a paint-jet printer. This apparatus is commonly known as a Continuous Ink Supply System and is available from numerous suppliers in the digital printing industry. Suitable printers are available from Epson as models C86, C88 and R800. The Epson printers are designed for use with pigment-type inks and employ a piezo-electric discharge mechanism. The size of the respective reservoirs is determined with reference to the particular color, the extent to which it is used in custom color formulations and the size of the printed samples typically requested by system users and other factors that will be determined based on experiential factors. Interchangeable reservoirs provide the advantage of changing the capacity based on current demand.

Detailed Description of the Invention Preparation of Colorant Printing Formulations

As will be apparent from the above description, the first step in the preparation of the pigment dispersions for formulating the colorant printing inks is to identify the pigments used in the manufacture of the pigment dispersions used to tint the paint bases. The pigments, whether they be derived organically or from natural-occurring mineral compounds, must be ground to a fineness that provides a particle size that will pass through the inkjet nozzle without clogging. Particle sizes in the 200 micron range and smaller can be used.

It has been found that many of the additives required in the formulation of pigment dispersions for tinting paint are not needed in the ink colorants and, in fact, produce deleterious effects. Useful pigment dispersions for the inks of the invention include from about 5% to 40% of pigment by weight in water. Small amounts of a water-soluble resin or resins, a humectant and one or more surfactants can be added to complete the pigment dispersion formulation. The pigment content in the finished ink formulation ranges from about 3% to 7% pigment by weight This is in contrast to typical paint formulations where the pigment content ranges from near zero up to about 5% to 60% by weight. Minor variations in the preferred formula for the various pigment dispersions may be required to account for the presence of "surface treatment" additives that are applied by pigment suppliers. Different suppliers of the same color and type of pigment use different surface treatment additives, the presence of which can affect certain properties of the pigment dispersion for the ink. Any such modifications as may be required are minor and are well within the ordinary skill in the art.

The final formulation of the pigment dispersion into an ink composition for use in an inkjet printer is dependent, to some extent, on the characteristics of the printer. These requirements are apparent from the great number of different cartridges and inks that are available as supplies for the numerous manufacturers of printers and the even greater number of models produced by any given manufacturer. Program Development

The development of the program for use in controlling the printer driver is comparable to that applied by the prior art. A twelve (12) head printer is provided with a cartridge or other reservoir means containing inks formulated with the pigment dispersions as described above that utilize the same pigments as the corresponding colorants used to tint paint bases. Formulations are selected and programmed based upon the experience and expectations of the color technician. The formulations are chosen to cover the broad spectrum of colors and correspond to printed merchandising aids of an existing system or a novel color palette that has been developed especially for an electronic display system. Each formulation is provided with a unique identifying code that is also entered in the program.

The printer is activated and the colors are printed as one or more fields on a paper or other substrate of the same type that will be used in printing the color sample card by the retail user. Preferably, the color field, or each of the fields, is accompanied by a unique identifying code, e.g., in a margin. These color calibration fields are then subjected to analysis by a photospectrometer and the corresponding data recorded in association with the unique color identifier. Assuming that the underlying color palette includes 2,760 different colors, a predetermined number of calibration color fields will be prepared and analyzed. The printer profiling can include from several hundred samples up to about one thousand for a palette of several thousand colors. The formulations for the remaining colors can be obtained by one of ordinary skill in the art using appropriate and well known algorithms to vary the colors and their relative proportions. Characteristics of Substrate

It has been found that optical brighteners commonly used in paper coatings and fillers adversely affect the accurate reproduction of colors. In a preferred embodiment, an uncoated acid-free 100% cotton paper is used as the printing substrate for producing the improved color sample cards in accordance with the invention. A matte finish paper stock has been found to produce superior results for flat architectural coatings.

In order to provide color cards for semi-gloss and gloss paint finishes, paper stock having corresponding surface characteristics are utilized. Paper storage and feed mechanisms of the type used with photocopy machines and desktop printers can be incorporated into the system for delivery of one of several types of paper in accordance with the computer directed processor/controller in response to the user's input selection.

Architectural surface coating systems that include up to 2760 individual colors can advantageously employ from eight to sixteen pigmented liquid printing colorants. Each of the colorants employs the pigments utilized in formulating pigment dispersion compositions of the type that are actually used in tinting the bases used in the architectural surface coatings, or paint. Historically, coloring systems employed in the U.S. typically have up to twelve colorant cartridges, while tinting apparatus used in Europe and elsewhere have up to sixteen colorant cartridges. The number of liquid colorants utilized in the printing of the color cards or other printed materials for products other than paints will depend, to some extent, upon the range of colors that the manufacturer intends to offer for its end products. For example, vinyl siding for commercial and residential use typically has a limited palette or number of colors in which it is commercially available so that the number of pigmented liquid colorants required to reproduce these colors need not be as extensive as those required for architectural surface coatings.

Other end products to which the formulations and methods of the invention can be applied include floor tiles produced from various tinted polymers and copolymers, roofing and other construction tiles fabricated from tinted plastics, bricks, pavers and other concrete products that are tinted.

The method and apparatus of the invention also provides manufacturers of end products with the opportunity to permit prospective purchasers, including architects, designers, contractors and even retail purchasers to select a custom color for use in the eventual production of the end product by using the same pigments in the inkjet printing system that are used to tint the end products. Offering purchasers this option also permits the manufacturer to establish a price that not only reflects the additional time and labor charges, but also colorant charges.

In the practice of this embodiment of the invention, the computer is provided with a program that allows the user to select a color or colors for the product that is within an acceptable manufacturing range for quality, durability and other specific characteristics. As will be understood by those of ordinary skill in the art, the addition of colorants and related additives cannot exceed predetermined limits without adversely affecting the quality of the particular end product. These limitations are readily determinable by one of ordinary skill in the relevant art. In a further aspect, the invention broadly contemplates the use of a plurality of pigment-based printing inks, i.e., a set of inks, prepared from liquid colorants mat are formulated using the same pigments that are employed in the manufacture of the end products to be pre-packaged and identified for the purchaser, e.g., by personalized labels. The plurality of liquid colorants can be supplied to the printer via conventional cartridges, but preferably via feed tubes connected to larger reservoirs for the production of printed color cards or other merchandising aids of the type customarily used in connection with the sale of the particular end products.

While the various preferred embodiments of the invention has been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous other variations, changes and substitutions will occur to those skilled in the art without departing from the invention herein. Accordingly, it is intended that the invention be determined by the interpretation and scope accorded the following claims.

Claims

CLAIMSWE CLAIM:

1. A color ink set consisting of a plurality of colored inks for use in conjunction with an inkjet printer having a corresponding number of active print heads, the printer being programmed to custom print color sample cards corresponding to the colors reproducible by custom mixing one or more paint pigment dispersions with a paint base to produce a color selected from an established palette of colors, the inks of the ink set being formulated using ^" the same type of pigments that are used to formulate the paint pigment dispersions to reproduce the colors of the established palette on the sample cards.

2. The color ink set of claim 1 which includes from 4 to 16 different colors.

3. An ink color pigment dispersion set for use in formulating a color ink set consisting of a plurality of color inks for use in conjunction with an inkjet printer having a corresponding number of print heads, the printer being programmed to custom print color sample cards corresponding to the colors reproducible by custom mixing one or more paint pigment dispersions wiih a paint base to produce a color selected from an established palette of colors, the inks of the ink set being formulated using the same type of pigments that are used to formulate the paint pigment dispersions to reproduce the colors of the established palette on the sample cards.

4. The ink color pigment dispersion set of claim 3 which includes from 4 to 16 different colors.

5. The ink color pigment dispersion set of claim 4 consisting of four colors formulated from tbe following pigments: a. black from carbon black PBk 7, b. magenta from PV 19, c. yellow from PY74, and d. blue from PBl 15 group, including 15:2, 15:3.

6. The ink color pigment dispersion set of claim 4 consisting of six colors formulated from the following pigments: a. black from carbon black PBk 7, b. magenta from PV 19, c. yellow from PY74, d. blue from PBl 15 group, including 15:2, 15:3, e. green from PG7, and

7. The ink color pigment dispersion set of claim 4 consisting of eight colors formulated from the following pigments: a. black from carbon black PBk 7, b. magenta from PVl 9, c. yellow from PY74, d. blue from PBl 15 group, including 15:2, 15:3, e. green from PG7,

g. yellow from PY42 and h. yellow from a PY74 / PY65 mix.

8. The ink color pigment dispersion set of claim 4 consisting of eleven colors foπnulated from the following pigments: a. black from carbon black PBk 1, b. magenta from PVl 9, c. yellow from PY74, d. blue from PBl 15 group, including 15:2, 15:3, e. green from PG7, f. red from PRl 88, g. yellow from PY42, h. yellow from a PY74 / PY65 mix, i. red from PRlOl₅ j . light black from PBk7, k. white from PWl.

9. The ink color pigment dispersion set of claim 3 in which each member of the set comprises pigments of an average particle size of less man 200 nanometers.

10. The ink color pigment dispersion set of claim 3 in which each member of the set comprises water, a biocide, a defoamer and a dispersing agent.

11. The color ink set of claim 1 in which each member of the set comprises water, a polyethylene glycol solution, a sequestering agent, 2-pyrrolidinone, diethylene glycol butyl ether.

12. A color inkjet printhead provided with the ink color pigment dispersion set of claim S.

13. A replacement cartridge for a color inkjet printer that has from four to sixteen nozzles that contains a corresponding number of color inks in accordance with claim 2.

14. A computer-based color selection system for personalized selection of one or more paint colors by a user, the paint colors to be custom-mixed according to a formulation using one or more pigment dispersions selected from a predetermined number of paint pigment dispersions, the system comprising: a color monitor; an input device for receiving user inputs and color selection inputs by the user; a computer operating a predetermined color selection program for interactively displaying colors and color schemes in response to color selection inputs by the user to generate a customized final color selection on the color monitor; and an inkjet printer and controller responsive to the color selection program for producing custom-printed color sample cards using inks formulated from ink pigment dispersions containing the same pigments as the corresponding paint pigment dispersions.

15. The color selection system of claim 14, wherein the input device includes a mouse.

16. The color selection system of claim 14, further comprising: a point-of-sale station including the input device.

17. The color selection system of claim 14, further comprising: a kiosk including the input device.

18. The color selection system of claim 14, further comprising: a workstation including the input device.

19. The color selection system of claim 14, further comprising: a network interface for transmitting the customized final color selection over the Internet to an external device.

20. The color selection system of claim 19, wherein the external device is an inkjet printer for dispensing inks corresponding to the customized final color selection.

21. The color selection system of claim 14, further comprising: an inkjet printer operatively connected to the computer for reproducing one or more paint colors utilizing liquid inks dispensed from nozzles onto a substrate positioned below the printer, the one or more colors corresponding to the user's final color selection.

22. The color selection system of claim 21, further comprising: a plurality of reservoirs containing colored inks in fluid communication with the inkjet printer for reproducing the paint colors based on the user's final color selection.

23. The color selection system of claim 21 , further comprising: printing paper supplied to the inkjet printer having a printing surface characteristic selected from the group consisting of gloss, semi-gloss and flat that corresponds to the finish of the paint of the customized final color selection.

24. The color selection system of claim 23, which includes a plurality of trays containing printing paper sheets having different surface characteristics and means for selectively delivering one sheet of paper from one of the plurality of trays in response to a selection by the user of a type of paint.

25. The color selection system of claim 24, wherein the printing papers correspond to a flat and semi-gloss surface finishes.

26. The color selection system of claim 24, which includes electronic actuation means that is responsive to a card bearing a magnetically encoded strip or a bar code to thereby permit user access.

27. The color selection system of claim 26, wherein the electronic actuation means is responsive to a credit card and a debit card.

28. The color selection system of claim 27, which includes means for storing and processing financial account information provided by the user upon the user's authorization during use of the system.

29. The color selection system of claim 23, wherein the selection layout includes indicia providing a discount coupon for use with a vendor.

30. The color selection system of claim 23, wherein the selection layout includes indicia providing a unique bar code corresponding to a color in the customized final color selection.

31. The color selection system of claim 23, which includes an electronic link to a computer-directed custom color paint tinting apparatus and associated memory device, whereby at least one final color selection product identifier is transmitted for storage in the associated memory device.

32. The color selection system of claim 31, wherein the number of liquid inks supplied to the inkjet printer corresponds to the number of paint colorants contained in the paint custom color mixing apparatus.