Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2000-08-24
2003-02-11
Klemanski, Helene (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C106S031640, C106S031490, C106S031780, C106S031580, C106S031860, C106S031650
Reexamination Certificate
active
06517619
ABSTRACT:
FIELD OF INVENTION
The present invention relates to solvent-based inks for writing instruments using fluorescent dyes and opacifying pigments.
BACKGROUND OF INVENTION
Writing instruments which are used to manually print text are in common use. The inks in these devices have traditionally used dyes (blue, black, red, green, etc.) which may exhibit a bright appearance on paper but do not exhibit a bright appearance in masscolor.
Current bright ink pens are either gel ink pens requiring a grease follower and point seal feature or free ink pens wherein the ink viscosity is low (less than 1000 cPs) and a flow control mechanism such as a baffle and/or capillary connectors is required. U.S. Pat. No. 4,671,691 to Case et al. and U.S. Pat. No. 4,726,845 to Thompson et al. disclose aqueous gel ink pens. Disadvantages to gel ink pens include additional production steps, additional cost to their production and short shelf life. U.S. Pat. No. 3,446,564 to Horie; U.S. Pat. No. 3,533,708 to Horie; U.S. Pat. No. 3,572,954 to Cheron; U.S. Pat. No. 3,873,218 to Yoshida; and U.S. Pat. No. 3,951,555 to Wittnebert et al. disclose writing instruments utilizing liquid reservoirs employing porous ink feed rods. Disadvantages to using porous ink feed rods include a potential failure to provide a sufficiently continuous flow of ink through the writing instrument tip to the paper.
U.S. Pat. No. 4,664,711 to Kawaguchi et al. discloses a fluorescent ink composition comprising (1) 5 -40% titanium dioxide treated with an alkaline earth metal or aluminum salt of a fatty acid; (2) organic resins, and (3) an organic solvent capable of dissolving the resins. The particle size of the TiO
2
is from 0.05 to 0.5 micron. U.S. Pat. No. 4,664,711 does not disclose treated titanium dioxide used below 5% of the formulation, nor any other opacifying agent other than TiO
2
.
U.S. Pat. No. 4,186,020 to Wachtel discloses a fluorescent printing ink comprising (1) an organic binder or carrier which dissolves in an organic solvent base and does not interfere with the fluorescence of the fluorescent dye or pigment component; (2) one or more fluorescent dye components which dissolve in the binder solution; (3) an organic phosphor, which may be a fluorescent dye or pigment of extremely high intensity and which dissolves in the organic solvent, and, optionally, (4) an organic brightener, and (5) an evaporation retardant. U.S. Pat. No. 4,186,020 does not disclose the use of non-organic opacifying agents used as brighteners.
U.S. Pat. No. 5,698,614 to Ueda et al. discloses a fluorescent ink composition comprising (1) an organic solvent comprising propylene glycol monomethyl ether, (2) a fluorescent pigment dissolved in the organic solvent comprising propylene glycol monomethyl ether and (3) a ketone resin. The ink composition of Ueda is particularly suitable for use in marking pens which have an ink reservoir composed of a bundle of fibers, wherein the ink composition is supplied from the ink composition by making use of capillary phenomenon. U.S. Pat. No. 5,968,614 does not disclose any opacifying agents used as brighteners.
U.S. Pat. No. 5,942,027 to Ikai et al. discloses an ink for a ballpoint pen comprising an organic solvent, colorant, resin, and fine particle silica having a particle diameter of 7 to 40 nm. The silica is used as an anti-seepage additive to control leakage from ballpoint pens. U.S. Pat. No. 5,942,027 does not disclose fluorescent dye nor does it disclose opacifying agents used as brighteners as recited in the present invention.
U.S. Pat. No. 3,997,498 to Reese et al. discloses a correction fluid composition comprising (1) an opacifying agent in an amount from about 15 to 35% by weight, (2) a halogenated ethane solvent, and (3) a resin. U.S. Pat. No. 3,997,498 does not disclose the use of these materials with fluorescent materials. Additionally, it does not disclose opacifying agents used below 5% by weight which act as brightening agents.
There is a need for fluorescent ink that can be used with traditional writing instrument mechanisms and solvent systems. Also desired is a fluorescent ink whose ink produces a particular brilliant appearance both within the ink containing member or tube of the writing instrument and on paper. Also desired is the ability to make many different colors and blends of ink for bright ink writing instruments. This invention satisfies these needs.
SUMMARY OF INVENTION
The object of the present invention is to provide fluorescent inks exhibiting a brilliant appearance in clear ink delivery members within clear pen barrels which can be delivered to paper reliably from a writing instrument. This fluorescent ink exhibits the same brilliance on paper as in the clear ink delivery member.
The ink composition of the present invention when placed in an optically transparent or translucent member or tube and mounted within an optically transparent or translucent barrel produces a brilliant appearance. The brilliance of the fluorescent ink is enhanced by the presence of an opacifying agent, which acts as a brightening agent. Although not intended to be limiting, it is believed that the combination of a white opacifying agent with a fluorescent dye enhances the brilliance of the fluorescent dye in the ink.
In a first embodiment of the present invention, a fluorescent ink composition for use in writing instruments comprises an organic solvent, a resin, a solvent soluble fluorescent colorant and an opacifying agent, whereby the opacifying agent acts as a brightener. Preferably, the ink composition has a viscosity from about 1,000 cPs to about 500,000 at 20° C. More preferably, the viscosity of the ink composition is from about 2,000 to about 50,000 cPs. Most preferably, the viscosity of the ink composition is from about 3,000 to about 30,000 cPs.
Preferably, the writing instrument is a ballpoint pen.
The fluorescent colorant may be used alone or in the form of a mixture of two or more fluorescent colorants. Preferably, the fluorescent colorant is present in the ink composition in amounts from about 0.1 to about 60 weight percent of the ink composition.
The opacifying agent may be used alone or in the form of a mixture of two or more opacifying agents. Preferably, the opacifying agent is an inorganic white pigment, such as silica, titanium dioxide and zinc oxide. Preferably, the opacifying agent has a particle diameter less than 1 micron. Depending on the refractive index of the opacifying agent, the amount of opacifying agent is from 0.1 to about 15.0% by weight of the ink composition.
When the refractive index of the opacifying agent is equal to or more than 2.0, the amount of the opacifying agent is from about 0.1 to 4.9 weight percent of the ink composition. Accordingly, one embodiment of the present invention is a fluorescent ink composition for use in a writing instrument comprising about 0.1 to 4.9 weight percent opacifying agent, with a refractive index of equal to or more than 2.0, a fluorescent dye, an organic solvent and a resin. Non-limiting examples of opacifying agents with a refractive index more than 2.0 are titanium dioxide (anatase and rutile), zinc oxide, zinc sulfide and zirconium oxide. Preferably, the particle diameter of these opacifying agents is from about 0.001 to about 5 microns. More preferably, the particle diameter of these opacifying agents is from about 0.01 to about 0.5 microns.
When the refractive index of the opacifying agent is less than 2.0, the amount of the opacifying agent is from about 0.1 to about 15 weight percent of the ink composition. Accordingly, another embodiment of the present invention is a fluorescent ink composition for use in a writing instrument comprising about 0.1 to about 15 weight percent opacifying agent, with a refractive index of less than 2.0, a fluorescent dye, an organic solvent and a resin. Non-limiting examples of opacifying agents with a refractive index less than 2.0 are silica, silicates, calcium carbonate, talc and china clay. Preferably, the opacifying agent is silica. Preferably, the particle diameter of the silica is from ab
Chen Qingping
Nowak Michael T.
BIC Corporation
Faison Veronica F.
Klemanski Helene
LandOfFree
Fluorescent inks for writing instruments using fluorescent... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fluorescent inks for writing instruments using fluorescent..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluorescent inks for writing instruments using fluorescent... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3151367