MXPA98006813A

MXPA98006813A - It eradicator system

Info

Publication number: MXPA98006813A
Application number: MXPA/A/1998/006813A
Authority: MX
Inventors: Wang Yichun
Original assignee: The Gillette Company; Wang Yichun
Priority date: 1996-02-22
Filing date: 1998-08-21
Publication date: 1999-02-24

Abstract

The present invention relates to: A combination of ink / eradicator fluid, including an ink containing a pigment and a binding agent, and an eradicating fluid containing a basic nitrogen compound. The binding agent is able to bind to the basic nitrogen compound

Description

INK ERADICATOR SYSTEM DESCRIPTION OF THE INVENTION This invention relates to ink eradicating systems. Ink eradicator systems generally include two components. A component is an aqueous ink that includes a pigment - typically a triarylmethane - which can be converted to a colorless form when contacted with a substance such as a sulfite reducing agent or a basic nitrogen compound. The second component is an aqueous eradicating fluid that includes a substance that can cause the colorant to be converted to a colorless form. A user writes with the ink and, if correction is necessary, apply the eradicating fluid to the mark with ink, to discolor the pigment. It is desirable to make possible the overwriting of the area to which an eradicating fluid is applied. A problem that can occur when overwriting an eradicated mark is attempted, is that the new mark may become discolored over time, as the pigment in the ink is put in REF. 28076 i contact with the excess eradicating substance (eg sulphite or amine) in the hardened eradicating fluid. The invention relates to the combination of an eradicable ink, aqueous ink and an aqueous eradicating fluid. The ink contains a pigment that discolours if it is contacted with a basic nitrogen compound, such as an amine.

The eradicating fluid contains the basic nitrogen compound. Importantly, the ink also includes an agent that binds to the basic nitrogen compound, which can bind to the excess basic nitrogen compound in the eradicating fluid. As a result, when the ink is used to overwrite an area to which the eradicating fluid has been applied, the basic nitrogen compound remaining in the eradicating fluid becomes bound to the binding agent of the nitrogen compound in the ink , and consequently does not cause significant discoloration of the pigment. The ink mark made on the eradicated area thus has a reduced tendency to discolour over time. The preferred pigments are triarylmethanes. The preferred basic nitrogen compounds are amines non-toxic, non-volatile, such as sodium glycinate. Preferred linking agents are metal salts. Magnesium salts such as magnesium sulfate and zinc salts such as zinc sulfate are examples of preferred binding agents. Preferred eradicating fluids also include a film forming polymer. The film forming polymer provides a thin film over the eradicated area, and as a result the overwriting time may decrease. It can also retard the diffusion of the eradicating fluid to paper, and can improve the quality of overwriting. Preferred ink-forming polymers include the sodium salts of polyacrylic acid. Preferred eradicating fluids have an eradication time of at least about 3 seconds, and more preferably less than 2 seconds. Preferred eradicating fluids have an overwrite time of less than about 15 seconds and more preferably less than 10 seconds. The invention also characterizes an eradicable ink that includes a pigment that discolours when the ink is brought into contact with a sodium glycinate solution at 8% by weight in water, and a metal salt capable of complexing with sodium glycinate. The invention also features a method of eradicating ink marking on a substrate. The method includes two steps. First, an ink containing a pigment which discolours if contacted with a basic nitrogen compound, a binding agent capable of binding to the basic nitrogen compound and water, is applied to the substrate to provide a label. Second, an eradicating fluid that includes the basic nitrogen compound and water is applied to the marking. The basic nitrogen compound causes the pigment to cecolorate. The invention also characterizes yet another method for providing a marking. This method also includes two steps. Firstly, an eradicating fluid containing a basic nitrogen compound and water is applied to a substrate to provide a coating of eradicating fluid. Second, an ink containing a pigment that discolours upon contact with the ink is applied to the eradicator fluid coating. composed of basic nitrogen, a binding agent capable of binding to the basic nitrogen compound and water. Preferably, the method also includes the initial realization of a mark on the substrate, on which the eradicating fluid is applied, with the same ink. "Eradication system", as used herein, means that a combination of an ink and a fluid are stored unmixed in the same general package. For example, the ink may be in a container and the eradicating fluid in a second container, but the two containers are included in the same package. Other features and advantages of the invention will be apparent from the description of the preferred embodiments thereof, and from the claims. Preferred combinations include an ink and an eradicating fluid. The ink contains a triarylmethane pigment, a metal salt capable of binding to the amine used in the eradicator fluid, an organic acid, a polyacrylate film-forming polymer and water. The eradicating fluid includes a non-volatile amine capable of discolouring the triarylmethane pigment, a polymer Film and water maker. The ink and the eradicating fluid may also include a surfactant to adjust the surface tension. Triarylmethane pigments that are capable of fading in the presence of an amine are known to those skilled in the art. Examples include Acid Blue 93 and Acid Blue 22. Sufficient pigment must be included in the ink to provide the intensity of the desired color, but not so much that large amounts of the eradicating fluid must be applied to a mark made with the ink, to cause that it is discolored. Preferred inks include between 2% and 5% and more preferably about 4%, of the triarylmethane pigment, by weight. Preferred metal salts are capable of binding to the amine used in the eradicating fluid. The metal salt is preferably also soluble in the ink. Examples of salts are magnesium sulfate and zinc sulfate. The ink should include an amount of metal salt sufficient to bind to the excess of amine when the ink is applied to a layer of eradicating fluid made on an ink mark. But you should not include too much metal salt, so that excessive amounts of eradicator fluid must be applied to eradicate the ink mark that is corrected. The ink mark to be corrected may include the metal salt, and there must be enough amine in the eradicator fluid to bind to the metal salt in the ink mark and to decolorize the pigment. Preferred inks include between 5% and 15%, and more preferably between 8% and 12%, of the metal salt, by weight. The organic acid increases the acidity of the ink and as a result increases the color intensity of the triarylmethane pigment. Examples of organic acids include citric acid, and tartaric acid. A sufficient amount of the organic acid must be included to provide an ink that includes a pigment of the desired intensity. Preferred inks may include between 1% and 3%, and more preferably 2%, of the organic acid, by weight. The polyacrylate film-forming polymer can improve the color intensity and reduce discoloration of the overwrite. Examples of polyacrylate film-forming polymers include Sokalan CPlOs, CP12s, and PA13PN, all of which are available from BASF. Sufficient polyacrylate film-forming polymer should be included in the ink to provide the objective benefit, but should not be included so much that the viscosity of the ink becomes undesirably high. Preferred inks may include between 1% and 5%, and more preferably between 2% and 4%, of the polyacrylate film-forming polymer, by weight. 10 Sufficient water should be included in the ink to dissolve the components and provide the ink with the desired viscosity. Preferred inks can have a viscosity of between 1 cps and 3 cps, and more preferably between 2 cps and 2.5 cps. The Preferred inks may include between 75% and 85% by weight of water. The non-volatile amine in the eradicating fluid causes the triarylmethane pigment to discolour when the fluid is applied over a mark made with the ink. The selected amine, in addition to being preferably non-volatile, must be non-toxic, and preferably odorless. Examples of preferred amines include glycine, (in the form of sodium glycinate), other amino acid salts and pol laminates. jgl «^ ag3 * gygg ^^" trt ~ '~' * '* ~ and ~ .ym -. * yt. ™ > --yt'-V "' and --y -rr - '^ S?« W «P '- ^ U'W-g'-WlW' '' - ^^ * ''« ^ ' Sufficient amine is included in the erradicator fluid to discolor the pigment, when applied in reasonable amounts to a mark made with the ink. But sufficiently large amounts of amine can interfere with the ability of the metallic salt in the ink to prohibit sufficiently the discoloration of a marking with corrective ink applied to a hardened eradicating fluid. Preferred eradicating fluids may include between 7% and 12%, and more preferably between 8% and 10%, of the amine, by weight. The film-forming polymer increases the viscosity of the eradicating fluid. This can also decrease the overwriting time by providing a thin film on the surface of a cover made with the eradicating fluid; The thin film increases the hardness of the surface, and can make the surface suitable to receive a mark made with ink, and even when the eradicating fluid has not completely dried. The film-forming polymer must be compatible with the amine used in the eradicating fluid. Preferred film-forming polymers are sodium salts of polyacrylic acids. Film-forming polymers of preferred polyacrylic acid have a number average molecular weight of between 1200 and 5000. A sufficient amount of film-forming polymer is included in the eradicating fluid, to provide the desired film and viscosity. Too much film-forming polymer can raise the viscosity to undesirable levels. Preferred fluids and radicants may include between 15% and 25%, and more preferably about 20%, of the film-forming polymer, by weight. Sufficient water should be included in the eradicator fluid to dissolve the components, and provide the fluid at the desired viscosity. Preferred eradicating fluids may have, for example, a viscosity between 5 and 15 cps, and more preferably between 6 cps and 7 cps. The eradicator fluid also preferably contains a buffer to maintain the pH of the solution, for example, between 11 and 12 (more preferably about 11.7). Preferred eradicating fluids may include, for example, between 75% and 85% of the aqueous buffer, in. weight. The surface tension of the ink and the eradicator fluid can have an impact on the eradication and overwriting operation of the eradication system. The surface tension of the ink is preferably between 30 dynes / cm and 45 dynes / cm, and more preferably is about 40 dynes / cm, and more preferably is about 40 dynes / cm. The surface tension of the eradicating fluid is preferably between 20 dynes / cm and 40 dynes / cm, more preferably between 25 kinas / cm and 35 dynes / cm, and more preferably is about 30 dynes / cm. The surface tension of the ink and the eradicating fluid can be adjusted using conventional surfactants. If the surface tension of the ink is too low, the ink can penetrate too low into a paper substrate, also rapidly relative to the erradicator fluid which is subsequently applied. If the surface tension of the eradicator fluid is too high, it can not penetrate into the paper as fast or at least as quickly as the previously applied ink. This could lead to either incomplete eradication or a long eradication period. Other conventional ingredients such as bactericides, thickeners and colorants can be included in the ink or in the eradicating fluid.

Preferred inks and eradicating fluids can be used in ball-point pens (pens), for example, pens that include a tubular member for fluid communication with a reservoir (either a fiber or hollow reservoir); a connector, having a seat, at one end of the member, an interior wall surface extending from the seat; a edge or edge placed at the end of the inner wall surface opposite the seat; and a spherical ball that is placed in the connector, rotatably engageable with the seat and captured by the edge. The writing instrument may also include, for example, a felt tip. The inks and the eradicating fluids can also be used in fountain pens. In one embodiment, the ink and the eradicator fluid are supplied in separate pens. If desired, several pens containing ink may be provided, each pen containing one ink. In another embodiment, the ink and the eradicating fluid are supplied in a simple pen, which contains a deposit for each one. Each deposit can be either a hollow or fiber deposit. The two deposits are surrounded by a tubular member, for example, a polypropylene barrel. If the pen is a marker, it includes tips at opposite ends, each tip being covered by a cap. An example of a suitable tip is the polyethylene pointed tip available from Interflo. Alternatively, if this is a rolling sphere tip pen it includes a ball structure and adapter plug, as described above, and as is well known in the art, at each end. The ink reservoir may be large enough, for example, to include approximately three times as much fluid as an eradicating fluid reservoir. The inks and the eradicating fluids can be prepared by mixing the components.

Example 1 An ink was prepared by mixing 4 parts of Acid Blue 93 (available from Orient), 2 parts of citric acid, 10 parts of magnesium sulfate, 2.5 parts of Sokalan CPlOs (available from BASF) and 81.5 parts of water.

An eradicating fluid was prepared by mixing 10 parts of sodium glycinate, 20 parts of sodium salt of polyacrylic acid (cat No. 42034-4, available from Aldrich), 0.2 part of surfactant (Dinol, available from Air Products) and 70 parts of an aqueous buffer solution (pH 11.7). One liter of the buffer solution includes 1.4841 boric acid, 4.1050 g sodium hydroxide, 1.4 ml acetic acid, and 1.4 ml phosphoric acid. The ink was used to write on paper for Ampad notes (available, for example, from Phase One Office Products Co., cat.No.AMP-20-372). The eradicating fluid was applied on a portion of the ink mark. After the eradicating fluid had sufficiently hardened, the marking was applied with corrective ink. No fading or discoloration of the corrective marking was observed.

Example 2 An eradicating fluid was prepared by mixing 10% (by total weight) of zinc sulfate, '"* fi ^ m * r? s 2. 5% Sokalan CPlOs, 2% citric acid, 4% Acid Blue 93, and 81.5% water.

Example 3 An eradicating fluid was prepared by casting 5% (by total weight) zinc sulfate, 5% magnesium sulfate, 2.5% Sokalan CPlOs, 2% citric acid, 4% Acid Blue 93, and 81.5% from aaua.

Other embodiments are within the claims. For example, an eradicating fluid may be used in combination with two inks, one of them including a metal salt that binds to the amine in the eradicating fluid, and the other that lacks the metal salt. An ink mark can be made on the paper with the ink lacking metal salt, and the eradicating fluid applied to discolor the pigment. Corrective marking can then be performed with the ink, which includes the metallic salt.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims

1. A combination of ink and eradicating fluid, characterized in that it comprises an eradicating fluid comprising a basic nitrogen compound and water, and an ink containing a pigment which is cemented if it is contacted with the basic nitrogen compound, a binding agent able to bind to the basic nitrogen compound, and water.

2. The combination according to claim 1, characterized in that the eradicator fluid further includes a film-forming polymer.

3. The combination according to the rei indication 2, characterized in that the film-forming polymer comprises a salt of polyacrylic acid.

4. The combination according to claim 2, characterized in that the eradicating fluid contains between 8% and 10% of the basic nitrogen compound by weight, between 15% and 25% of the * Fs • * ", J.-jgFS! T-y? Gyg -" !: gl T-vt? ** • «> . . m & mwßsnv ^ t? m i wi * Film-forming polymer by weight, and between 60% and 70% by weight of water.

5. The combination according to claim 1, characterized in that the ink also includes a film-forming polymer.

H.H. The combination according to claim 1, characterized in that the ink contains between 3% and 4% by weight of the pigment, between 8% and 12% by weight of the linking agent, and between 75% and 85% by weight of water.

7. The combination according to claim 5, characterized in that the film-forming polymer comprises a polyacrylate.

8. The combination according to claim 7, characterized in that the pH of the eradicating fluid is between about 10 and about 11.

9. The combination according to claim 1, characterized in that the pigment comprises a triarylmethane.

10. The combination according to claim 1, characterized in that the ink further comprises an organic acid.

11. The combination according to claim 1, characterized in that the binding agent comprises a metal salt.

12. The combination according to claim 11, characterized in that the metal salt comprises a magnesium salt.

13. The combination according to claim 12, characterized in that the magnesium salt comprises magnesium sulfate.

14. The combination according to claim 11, characterized in that the metal salt comprises a zinc salt.

15. The combination according to claim 14, characterized in that the zinc salt comprises zinc sulfate.

16. The combination according to claim 1, characterized in that the basic nitrogen compound comprises an amine.

17. The combination according to claim 16, characterized in that the amine comprises a sodium glycinate.

18. The combination according to claim 1, characterized in that the eradicating fluid has an eradication time of at least 3 seconds.

19. The combination according to claim 1, characterized in that the eradicating fluid has an overwriting time of less than 10 seconds.

20. The combination according to claim 1, characterized in that the ink has a surface tension of between 25 dynes / cm and 35 dynes / cm, and the eradicating fluid has a surface tension of between 35 dynes / cm and 40 dynes / cm.

21. An eradicable ink, characterized in that it comprises a pigment that discolours when the ink is contacted with an 8% by weight solution of sodium glycinate in water, a metal salt capable of complexing with sodium glycinate, and water.

22. The eradicable ink according to claim 21, characterized in that the ink further comprises a non-volatile organic acid.

23. The eradicable ink according to the rei indication 21, characterized in that the metal salt comprises a salt selected from the group consisting of magnesium salts and zinc salts.

24. A method for eradicating a marking of ink on a substrate, characterized in the substrate because it comprises applying to the substrate an ink comprising a pigment that discolours if it is contacted with a basic nitrogen compound, a binding agent capable of binding to the substrate. composed of basic nitrogen, and water, to provide a label on the substrate, and , + 22 applying an eradicating fluid to the marking comprising the basic nitrogen compound and water, the basic nitrogen compound causes the pigment to discolour.

25. The method according to claim 24, characterized in that the binding agent comprises a metal salt.

26. The method according to claim 24, characterized in that the basic nitrogen compound comprises an amine.

27. A method for providing a marking, characterized in that it comprises the application of an eradicating fluid containing a basic nitrogen compound and water, to a substrate, to provide a coating of eradicating fluid on the substrate, and 0 the application to the coating of the fluid eradicator, of an ink containing a pigment that discolours upon contact with the basic nitrogen compound, a binding agent capable of binding to the basic nitrogen compound, and water. INK ERADICATOR SYSTEM SUMMARY OF THE INVENTION A combination of .tinta / eradicator fluid, including an ink containing a pigment and a binding agent, and an eradicating fluid containing a basic nitrogen compound is disclosed. The binding agent is capable of binding to the basic nitrogen compound.