The invention relates to correction fluid products:
Correction fluids are used for correction handwritten, typewritten
or photocopied markings on paper. Generally, correction fluids are applied to a
paper surface in liquid form. After application, the fluids harden to a film which
can effectively cover erroneous markings on the surface and can receive a corrected
marking. Correction fluids typically contain a resin that provides the flexible
film, and an opacifying pigment, usually titanium dioxide, dispersed in a liquid.
The liquid may be water or an organic solvent.
Correction fluids are often supplied in a small container with an
applicator brush attached to the cap through a stem. A user unscrews the cap from
the container and withdraws the brush loaded with correction fluid. The user then
contacts the erroneous marking with the brush, and correction fluid is transferred
to the substrate to cover the marking.
The invention relates to a correction fluid product comprising a body,
a correction fluid and an applicator that can be used to apply correction fluid.
The applicator preferably includes a stem, an applicator tip including foam in
contact with the correction fluid, the foam having an average pore size of between
20 ppi and 130 ppi, and preferably a flexible material, i.e., a flexor, within
the tip. The applicator is easy to use and preferably can be inserted into a correction
fluid container in the same general manner as brush applicators. The applicator
provides an even laydown of correction fluid on a substrate, resulting in good
correction quality. The applicator has good durability and facilitates precise
In one aspect, the invention relates to product with an applicator,
including a stem and an applicator tip including foam, having a flexibility of
at least 0.0005 inch of deflection per gram of force, preferably at least 0.002
inch of deflection per gram of force.
In another aspect, the invention features an applicator, including
a stem and an applicator tip including foam, having an angled chisel-shaped application
surface for applying correction fluid to a substrate.
In another aspect, the invention relates to a product with an applicator
including a stem and an applicator tip including a quenched foam. By quenched foam,
it is meant a foam that is reticulated (substantially all membranes have been removed
to make it open-celled) by chemical methods.
Preferably, the product also includes an insert through the opening,
through which the applicator passes during use. Preferred inserts include a narrowed
neck portion that removes excess correction fluid when the applicator tip is withdrawn
from the reservoir.
The invention further relates to a product within an applicator having
an applicator tip including foam, a correction fluid reservoir, including correction
fluid, from which the correction fluid is fed to the applicator tip. The applicator
has a flexibility of at least 0.0005 inch of deflection per gram of force. the
applicator may also include a removable enclosure (e.g., a cap) for the tip.
Other features and advantages of the invention will be apparent from
the description of the preferred embodiment thereof, and form the claims.
Fig. 1 is an exploded view of a correction fluid container including a correction
Fig. 2 is a side of the end portion (including the applicator tip) of the foam
applicator in Fig. 1;
Fig. 3 is a side view of the applicator tip removed from the applicator in Fig.
2, with the portion of the flexor within the tip shown in broken lines;
Fig. 4 is a front view of the end portion of the foam applicator tip in Fig.
Fig. 5 is a side view of a second applicator, with the flexor shown in broken
Fig. 6 is a side view of a third applicator, with the flexor shown in broken
Fig. 7 is a rear view of the applicator in Fig. 6.
Referring to Figs. 1-4, a correction fluid container 10 includes a
cap 12, an applicator 14, a body 16 including a correction fluid reservoir, and
an insert 18.
Applicator 14 includes a stem 20, and an applicator tip 22. The applicator
tip includes a foam portion 24 enclosing a flexor 26. The applicator has a flexibility
of at least 0.0005 inch of deflection per gram of force, preferably at least 0.002
inch of deflection per gram of force, measured as described below. The flexibility
of the applicator depends on a number of factors, including the stiffness of the
stem; the composition, length, width, and thickness of the flexor; and the chemical
composition and thickness of the foam portion.
The stiffness of the stem depends on the composition, length, and
diameter of the stem. Generally, the less stiff the stem, the more flexible the
applicator. Stems composed of softer materials are less stiff than stems composed
of harder materials, and longer stems are less stiff than shorter stems. Stems
may be made of, for example, polymeric materials such as a low density and/or high
density polyethylene or polypropylene. The stem may have a length, for example,
of between 2 cm and 15 cm, and preferably between 2 cm and 10 cm. It also may
have a diameter of between, for example, 0.1 cm and 2 cm, and preferably between
0.2 cm and 0.8 cm. Stem 20 has a length of 4.1 cm and a diameter of 0.31 cm.
Flexor 26 includes an extension 28 that fits into the hollow end of
Generally, the softer the foam and the thinner the applicator tip
the greater the flexibility of the foam applicator. The foam is an open cell foam
having a pore size of between 20 ppi and 130 ppi, preferably between 80 ppi and
120 ppi, and may be, for example, a polyether/polyurethane, polyester/polyurethane,
polyether, or polyester foam. The foam can have a density, for example, in the
range of 1.6 lb/ft3 to 15.0 lb/ft3, a compression deflection
(CLD) of 25% R (radius) at (0.05-5.0) psi and a CLD of 65% at (0.2-10) psi. A preferred
foam is a quenched polyester polyurethane foam having a density of 1.85 lb/ft3,
a pore size of 80 ppi to 120 ppi, a CLD of 25% R at 0.25 psi, and a CLD of 65%
R at 0.45 psi.
The foam portion (including the enclosed flexor) may have a thickness
(t1), for example, of between 0.16 cm and 1.27 cm, a length (1) of between
0.3 cm and 2.0 cm, and a width (w) between 0.2 cm and 1.0 cm. Foam portion 24 has
a thickness (t1) (at midpoint) of about 0.44 cm, and a length (I) of
about 0.9 cm. Foam portion 24 is tapered and has a thickness at its base of about
0.44 cm and a thickness towards its tip of about 0.34 cm.
Generally, the softer the composition of the flexor the greater the
flexibility of the foam applicator. The flexor may be composed, for example, of
a composite of linear low density polyethylene and a thermoplastic olefin having
a very high softness and low modulus (e.g., Adflex KS-359P, available from Mobil),
low density polyethylene, high density polyethylene, polypropylene, or nylon. In
addition, as a general rule, thinner flexors provide more flexible foam applicators.
The flexor may have, for example, a width (w) of between 0.02 cm and 0.15 cm,
and a thickness (t) of between 0.1 cm and 1.0 cm. Flexor 26 has a width (w) of
0.06 cm. Flexor 26 is tapered but has a thickness of about 0.25 cm at its mid-point.
Foam applicator 14 has an angled chisel-shaped applicator surface
30 that includes a point 32. The angle (α in the Figure) preferably is between
15° and 60° (e.g., 30°). The long applicator side surface can be used to apply
correction fluid over words; the point or straight edge of 32 allows a user to
easily apply correction fluid to individual letters.
Insert 18 may be composed, for example, of a high density polyethylene.
The insert has a narrowed neck region 30 that may have an inside diameter of between
3.0 mm and 5.0 mm (e.g., 3.8 mm), and may have a length of between 5 mm and 40
mm (e.g., 25 mm). When portion 24 is removed (wiped off) from the correction fluid
reservoir for use, excess correction fluid is removed by narrowed neck 34. When
portion 24 is reinserted into the fluid reservoir after use, any excess correction
fluid that comes off portion 24 during reinsertion generally is accommodated by
the portion of insert 18 above the narrowed neck, thus avoiding spillage of correction
Applicator 10 may be used with organic solvent-based or water-based
correction fluids. In addition to the liquid vehicle, correction fluids may include
an opacifying agent such as titanium dioxide, a film-forming polymer, and various
other standard ingredients. Correction fluids may have a viscosity, for example,
of between 10 cps and 2000 cps, preferably between 30 cps and 1000 cps, at 20 rpm
using a Brookfield Viscometer. Preferred correction fluids are described in, for
example, U.S. Patent Nos. 5,199,976 and 5,306,755, which are incorporated by reference
Referring to Fig. 5, an applicator 34 has a design similar to applicator
14. Applicator 34, unlike applicator 14, does not have a tapered foam portion or
Referring to Figs. 6 and 7, an alternative applicator 36 has a spear-shaped
tip and includes a stem 38, a flexor 40, and a foam portion 42.
The flexibility of an applicator can be measured using an Instron
Model 1122 Compression Tester. The capped end of the applicator is attached to
a fixed stand, having a rotating fixture to vary the angle of attachment. The angle
is set at 40° so that the foam-tip is just underneath the vertical cylinder (probe)
of the tester, having a diameter of 15 cm. This probe is then moved downwards slowly
at a controlled rate of 0.13 cm/min while pressing the foam-tip during its downward
movement. The force generated by the probe to deflect the foam-tip and the actual
deflection of the foam-tip were continually monitored and transmitted to a recorder
for recording on a X-Y graph. The flexibility (calculated from the graph) corresponds
to the ratio of deflection distance to the applied force, i.e., the slope of deflection
vs. applied force graph. The measurements are conducted at various deflection distances,
e.g., 0.05", 0.1", 0.15", 0.20" and 0.25".
The flexibility of 12 applicators was measured according to this
procedure. The results are shown below in Tables 1 and 2. "Spear" in the applicator
in Figs. 6 and 7; "Chisel #1" is the applicator in Figs. 1-4; and "Chisel #2" is
the applicator in Fig. 5.
Although the flexibility of the examples were measured at various
deflection distances, "flexibility"(as that term is used in the claims) should
be measured at a deflection distance of 0.05".
A correction fluid product, comprising
a body including a reservoir and an opening,
a correction fluid within the reservoir, and
an applicator, inserted through the opening, including a stem and an applicator
tip including foam in contact with the correction fluid, the foam having an average
pore size of between 20 ppi and 130 ppi.
The product of claim 1, wherein the applicator further comprises a flexor within
The product of claim 1 or 2, wherein the foam comprises a polyurethane/polyester.
The product of claim 1 or 2 wherein the foam has a density from 1.6 to 15 pounds
per cubic foot.
The product according to claim 4, wherein the foam has a porosity from 80 ppi
to 120 ppi.
The product according to claim 4 or 5, wherein the foam is a polyester polyurethane.
The product according to claim 6, wherein the foam is a quenched foam.
The product according to claim 7, wherein the foam has a density of 1.85 pounds
per cubic foot.
The product according to claim 6, wherein the foam is a fully open cell polyester
polyurethane foam with a density of 6 pounds per cubic foot and a porosity of 100
ppi to 110 ppi.
The product according to claim 4, wherein the foam has a minimum elongation
of 250 percent.
The product according to claim 10, wherein the foam has a minimum elongation
of 500 percent.
A method of applying a correction fluid to cover a marking on a substrate using
an applicator including a stem and an applicator tip including a foam having an
average pore size of between 20 ppi and 130 ppi, comprising
loading correction fluid onto the applicator tip, and
contacting the surface with the applicator tip to transfer correction fluid over
The method of claim 12, wherein the applicator further comprises a flexor within