Liquid ink

Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C401S141000, C401S142000, C401S198000, C401S209000, C524S509000, C524S516000, C524S542000, C260SDIG031, C106S031130, C106S031270, C106S031280

Reexamination Certificate

active

06518329

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to liquid inks. More particularly, it relates to liquid inks for marking instruments.
Marking instruments, e.g., pens and markers, have a tip to which a liquid ink is supplied from a reservoir to be applied onto a substrate, such as a sheet of paper, by means of the tip which is moved over the surface of the substrate to leave a liquid trace.
Traditionally, liquid inks for marking instruments either have a viscosity of about 5 centipoise (“cps”) or lower (e.g., for fiber tip pens or fountain pens), or have a viscosity of about 7,500 cps or higher (e.g., for ball point pens). The latter usually contain a certain amount of a polymeric material(s).
SUMMARY OF THE INVENTION
One of the features of the present invention involves non-erasable liquid inks for marking instruments with a distinctive range of viscosity.
Thus, one aspect of the invention relates to a non-erasable liquid ink, with a water content of about 0-15% by weight, for a marking instrument. By “erasable ink” is meant an ink, which, after being deposited on a porous substrate, cannot be erased using a conventional rubbery eraser. The non-erasable ink includes a solvent and a colorant, e.g., a dye or a pigment, dissolved or dispersed in the solvent, and has a viscosity of about 15 to 4,500 cps. More preferred ranges of viscosity include, but are not limited to, about 50 to 2,000 cps, about 100 to 1,000 cps, or about 150 to 600 cps. The viscosity of an ink of this invention described herein is that measured at a shear rate of 300 sec
−1
at room temperature.
The liquid ink may also contain one or more polymers with averaged molecular weights ranging from about 1×10
4
to 1×10
6
daltons (preferably, about 1×10
5
to 6×10
5
daltons) with the total content of the polymer(s) being about 0.05% to 2.5% by weight of the ink. A more preferred range of the total polymer contents is about 0.05% to 1.0%. It is particularly preferred that the total polymer content be about 0.3%. Examples of suitable polymers include, but are not limited to, polyvinylpyrolidone (“PVP”) and, ketone/formaldehyde resin.
Preferably, one or more lubricants, such as oleic acid or oleic diethanolamine (“ODEA”), can be incorporated in the liquid ink as to decrease friction resulting either from contact between a marking instrument and the substrate (e.g., paper) onto which a marking is being made, or, in the case of a ballpoint pen, from contact between the roller ball and the socket, thereby enhancing smoothness in using the marking instrument.
The colorant used in the liquid ink may be either a dye (i.e., which can be dissolved in a solvent), or a pigment (i.e., which can only be dispersed, rather than dissolved, in a solvent). When a pigment is used, it is preferred that a gelling agent be also included in the ink so as to prevent pigment sedimentation or ink leakage.
Another aspect of this invention relates to a non-erasable liquid ink, with a water content of about 0-15% by weight, for a marking instrument which includes (i) one or more polymers with averaged molecular weights ranging from about 1×10
4
to 1×10
6
daltons, preferably, about 1×10
5
to 6×10
5
(e.g., PVP or ketone/formaldehyde resin), (ii) a colorant, and (iii) a solvent, with the total content of the polymer(s) being about 0.05% to 2.5% by weight (more preferably, about 0.05% to 1% by weight) of the ink. In a particularly preferred embodiment, the total polymer content is about 0.3% by weight. Similarly, whenever necessary, other ingredients, such as a lubricant or a gelling agent, can also be included in the ink.
Note that a colorant incorporated in an ink of this invention does not include a colored polymer, e.g., polymeric dyestuff. Similarly, a polymer used in this invention is, by definition, not colored. By “polymer” is meant a macromolecule consisting essentially of repeating units with a molecular weight of at least 1×10
4
daltons. A preferred M.W. range is about 1×10
4
to 1×10
6
daltons. A particularly preferred M.W. range is about 1×10
5
to 6×10
5
daltons.
Also within the scope of this invention is a marking instrument which includes: a body, a reservoir chamber within the body, and a liquid ink in the chamber. The liquid ink may be an ink of the present invention as described above, or an ink of a lower viscosity which is most suitable for use in fiber tip pens or fiber tip highlighters.
Preferably, the marking instrument further includes an ink feed device having a channel for conducting the ink from the chamber to a marking tip, an elastomeric member which partly confines the chamber and supports the feed device with respect to the body, and a valve defined by the feed device and the elastomeric member for controlling communication between the chamber and the channel, whereby the feed device is retractable relative to the body under a force exerted against the tip, and in response to such retraction the chamber is pressurized by deflection of the elastomeric member and the valve is opened to allow the ink to enter the channel from the chamber. Note that the marking instrument constructed in a manner described above may be equipped with a variety of different marking tips (e.g., a roller ball) and is not limited to any particular type of tip.
A further aspect of the present invention relates to a method of making a marking on a substrate, e.g., a piece of paper. The method includes the steps of: providing one of the above-described liquid inks of this invention, and applying the liquid ink against a surface of the substrate forming a marking.
One feature of the invention is the use of the valved ink feed device which allows lower viscosity ink to flow to the marking tip only when the tip is pressed against a writing surface. Without this valve restricting flow to the tip, the lower viscosity ink would tend to leak from the marking tip. By use of this valved ink feed device, lower viscosity ink can now be used, the ink having lower writing friction when applied.


REFERENCES:
patent: 2870742 (1959-01-01), Hackmyer
patent: 2874679 (1959-02-01), Zepelvitch
patent: 3420610 (1969-01-01), Malm
patent: 3424537 (1969-01-01), Henriksen
patent: 3656857 (1972-04-01), Seregely
patent: 3792932 (1974-02-01), Henriksen
patent: 3834823 (1974-09-01), Seregely et al.
patent: 3875105 (1975-04-01), Daugherty et al.
patent: 3884707 (1975-05-01), Dick et al.
patent: 3949132 (1976-04-01), Seregely et al.
patent: 4389499 (1983-06-01), Risegraf
patent: 4390646 (1983-06-01), Ferguson
patent: 4391927 (1983-07-01), Farmer
patent: 4471079 (1984-09-01), Enami
patent: 4509876 (1985-04-01), Hori
patent: 4721739 (1988-01-01), Brenneman et al.
patent: 4786198 (1988-11-01), Zgambo
patent: 4940628 (1990-07-01), Lin et al.
patent: 4973180 (1990-11-01), Hori
patent: 5120359 (1992-06-01), Uzukawa et al.
patent: 6075070 (2000-06-01), Lin et al.
patent: 926 054 (1954-08-01), None
patent: 0 109 726 (1984-05-01), None
patent: 0 413 273 (1991-02-01), None
patent: 0 476 492 (1992-03-01), None
patent: 153.504 (1987-10-01), None
patent: 135878 (1982-08-01), None
patent: 59-068381 (1984-04-01), None
patent: 60-158277 (1985-08-01), None
patent: 61-60768 (1988-12-01), None
patent: 2-20982 (1990-02-01), None
patent: 313396 (1991-01-01), None
patent: 91-013396 (1991-01-01), None
patent: 3-73398 (1991-03-01), None
patent: 4-85094 (1992-03-01), None
patent: 4-119897 (1992-04-01), None
patent: 4-119898 (1992-04-01), None
patent: 92-332697 (1992-11-01), None
patent: 92-332698 (1992-11-01), None
patent: 93-007822 (1993-01-01), None
patent: WO 93/05966 (1993-04-01), None
British Provisional Specification No. 812,704, Marks & Clerk, Apr. 15, 1957.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Liquid ink does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Liquid ink, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid ink will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3124249

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.