Correction fluid containing a butyl methacrylate copolymer ditridecyl phthalate, a non-halogenated solvent and an opacifying agent

An ozone-friendly correction fluid includes a non-halogenated solvent, a butyl methacrylate copolymer as the polymeric film-forming material, a plasticizer, and an opacifying agent.

The invention relates to correction fluids. 
Correction fluids for correcting handwritten, typewritten or photocopy 
markings on paper are well known and their performance characteristics are 
well defined. Essential performance characteristics include the ability to 
provide a film or coalesced residue on drying which can both effectively 
cover erroneous markings on a paper surface and receive a corrected 
marking. Preferably, the film covering the marking should be strongly 
bonded to the paper surface and should also be sufficiently flexible so 
that the film will not be removed under normal conditions of handling. 
Additionally, the correction fluid should not interact with the marking to 
cause excessive discoloration of the resulting film (bleeding). Another 
important performance characteristic involves the drying rate of the 
composition which should be as rapid as possible so that corrections can 
be made relatively quickly. Normally, commercial correction fluids form 
films which are sufficiently dry to receive a corrected marking in about 
30-40 seconds. 
Correction fluids typically are a dispersion, i.e., a suspension of solid 
particles in a liquid. When a correction fluid sits around for some length 
of time the solid particles begin to settle, causing the fluid near the 
bottom of the container to become more compact. Compact settling is 
undesirable because it is no longer easily redispersed thereby reducing 
coverage or the ability of the fluid to cover markings. 
Correction fluids typically include some standard ingredients, including an 
opacifying agent, a film-forming polymeric material, a volatile solvent, 
and a dispersing agent. The opacifying agent is the solid that is 
dispersed in the fluid and provides the basis white color which can be 
toned with other pigments to provide a correction fluid closely 
corresponding to the color of the paper to which the fluid is to be 
applied. The film-forming polymeric material is substantially soluble in 
the selected solvent and binds pigment to paper and helps to form the 
flexible but solid covering that remains once the solvent evaporates. The 
volatile solvent is a carrier for all ingredients mentioned herein. The 
dispersing agent is included to stabilize the dispersion, i.e., to help 
ensure that the opacifying agent remains uniformly dispersed in the 
solvent. 
Historically, halogenated hydrocarbons have been the solvents of choice for 
correction fluid compositions. Halogentated hydrocarbon solvents present 
special advantages primarily because they have evaporation rates which 
provide correction fluids that dry rapidly and completely. Additionally, 
they do not interact with typewritten markings to cause unacceptable 
bleeding. Also, they can effectively dissolve those film-forming polymeric 
materials which provide durable but flexible films without causing 
excessive cockling or distortion of paper surfaces. Despite their 
recognized advantages when used as correction fluid solvents, the use of 
halogenated hydrocarbon solvents has become a matter of increased concern 
primarily because of their adverse effect on the environment 
(stratospheric ozone depletion). Accordingly, providing an 
"ozone-friendly" correction fluid be eliminating the use of halogenated 
hydrocarbon solvents from correction fluids has become a primary objective 
for the art and significant efforts have been directed to the development 
of correction fluids free of halogenated hydrocarbon solvents. By 
ozone-friendly correction fluid, we mean a correction fluid which either 
does not contain a material that migrates to the stratosphere or, if it 
contains such a material, the material does not cause a reduction in the 
ozone concentrations. 
SUMMARY OF THE INVENTION 
The invention features, in one aspect, a correction fluid includes a 
volatile, non-halogenated solvent; an butyl methacrylate copolymer as a 
film-forming material; a plasticizer; and an opacifying agent such as 
titanium dioxide. Preferably, the composition also contains a dispersing 
agent. By volatile, it is meant that the solvent has a boiling point of 
less that 155.degree. C. 
The invention features, in another aspect, a correction fluid that includes 
a volatile, non-halogenated cyclohexane or alkylated cyclohexane 
containing 10 or fewer carbon atoms as a solvent; a film-forming polymeric 
material; an alkyl sodium sulfosuccinate as a dispersing agent; a 
plasticizer for the film-forming polymeric material and an opacifying 
agent. 
The invention features, in yet another aspect, a correction fluid that 
includes a volatile, non-halogentated cyclohexane or alkylated cyclohexane 
containing 10 or fewer carbon atoms as a solvent; a film-forming polymeric 
material; a polymeric fatty ester as a dispersing agent; a plasticizer for 
the polymeric material; and an opacifying agent. 
The invention features, in still another aspect, a correction fluid that 
includes a volatile, non-halogenated mixture of paraffins and naphthenes 
as a solvent; a film forming polymeric material, preferable an isobutyl 
methacrylate copolymer or n-butyl methacrylate copolymer; a copolymeric 
fatty ester as a as a dispering agent; a plasticizer for the polymeric 
material; and an opacifying agent. 
The preferred dispersing agents include polymeric fatty esters or dialkyl 
sodium sulfosuccinates. Examples of preferred agents include dioctyl 
sodium sulfosuccinate and bistridecyl sodium sulfosuccinate. 
Preferred alkyl cyclohexane solvents include methylcyclohexane, 
ethylcyclohexane, and dimethylcyclohexane; the most preferred alkyl 
cyclohexane solvent is methylcyclohexane. When a paraffin/naphthene 
solvent is used according to the present invention, it is desirable to 
utilize a mixture which is high in paraffinic hydrocarbons, preferably 
about 40%, low in aromatic hydrocarbons, preferably from 0 to 10% 
aromatic, and the balance being naphtene, preferably about 60%. Most 
preferably the paraffinic hydrocarbon is predominently C.sub.7. The most 
preferred such blend is Tolu-Sol.TM. WHT manufactured by Shell Oil Co., 
Houston, Tex. These solvents can also be a blended with additional 
solvents, preferably, such blends include at least 50% of the cyclohexane, 
alkylated cyclohexane and/or naphthene/paraffin solvent by weight. 
Preferred additional solvents include odorless mineral spirits, isopropyl 
alcohol or dibasic ester (DBE), manufactured by DuPont Chemicals, 
Wilmington, Del., which is a blend of 45-75% dimethyl glutarate, 10-25% 
dimethyl adipate, and 15-30% dimethyl succinate. 
The preferred correction fluid includes between 35% and 55% by weight 
solvent; between 4% and 13% by weight copolymer; between 1% and 4% by 
weight plasticizer; between 0% and 3.5% by weight dispersing agent; and 
between 35% and 55% by weight opacifying agent. 
The correction fluid provides excellent coverage without bleeding typed 
originals writing inks, and copies. Importantly, the fluid exhibits 
excellent pigment redispersibility after long term storage. Also, because 
a non-halogenated solvent is employed in the fluid, it is ozone-friendly. 
Other features and advantages of the invention will be apparent from the 
description of the preferred embodiment thereof, and from the claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The preferred correction fluid includes methylcyclohexane as the solvent; 
isobutyl methacrylate or n-butyl methacrylate copolymer as the 
film-forming material; ditridecyl phthalate plasticizer; titanium dioxide 
as the opacifying agent; lamp black as a pigment to color match paper; 
mustard oil as a denaturant; and a fragrance. Most preferably the 
correction fluid also contains dioctyl sodium sulfosuccinate or a 
polymeric fatty ester as the dispersing agent. 
A sufficient amount of solvent should be included to make the fluid thin 
enough to be easily spread. So much should not be used so that the hiding 
power of the fluid diminishes. Preferably, the correction fluid should 
include 35%-55% by weight solvent. 
The preferred isobutyl methacrylate copolymer has a specific gravity of 
about 1.05 gm/cc and is available under the trade name PLEXIGUM(.RTM.) P28 
AND NeoCyrl B-705, manufactured by Rohm GmbH Chemische Fabrik, and ICI 
Resins U.S. respectively. The preferred n-butyl methacrylate copolymers 
are available under the trade name Elvacite 2044, 2045, 2046, manufactured 
by DuPont Company. 
A sufficient amount of the material should be included to provide good 
flexibility to the covering, but not so much that the viscosity of the 
fluid becomes too high, which can lead to reduced coverage and difficult 
brushing. The present correction fluid also contains an effective amount 
of a plasticizer to improve flexibility of the copolymer. Preferred 
plasticizers are dialkyl phthalate compounds and a most preferred 
plasticizer is Jayflex(.RTM.) (DTDP) brand ditridecyl phthalate 
plasticizer distributed by Exxon Chemical. Preferably, the correction 
fluid includes between 1% and 4% plasticizer. Preferably, the correction 
fluid includes between 4% and 12% of the copolymer. 
The preferred dialkyl sodium sulfosuccinate, dioctyl sodium sulfosuccinate, 
is sold under the trade name AERISOL OTS by American Cyanamid Co. The 
preferred polymeric fatty ester is sold under the trade name HYPERMER LPI 
by ICI Specialty Chemicals. A sufficient amount of the agent should be 
included to achieve complete dispersion of the titanium dioxide, but not 
so much should be included that the hiding power is reduced. The preferred 
fluid includes between 0% and 3.5% polymeric fatty ester by weight. 
Bistridecyl sodium sulfosuccinate (sold under the trade name AEROSOL TR70 
by American Cyanamid Co.) can also be used. 
Suitable titanium dioxide pigments include commercially available rutile 
titanium dioxides and anatase titanium dioxides or blends or mixtures of 
these which preferably have an average particle size between about 0.2 to 
about 0.4 microns and an average oil absorption of about 14 lbs. oil/100 
lbs. pigment to about 36 lbs./100 lbs. The amount of titanium dioxide 
included in the composition can vary depending on the degree of coverage 
desired. However, amounts between about 30 to about 60 percent by weight 
titanium dioxide based on total weight of composition are generally 
suitable. Other opacifying pigments may be used either alone but 
preferably in combination with the titanium dioxide. Such pigments include 
zinc sulfide and zinc oxide. Preferably the fluid includes between 35% and 
55 % of the opacifying agent by weight. 
Lamp black is included as a coloring pigment to match the color of fluid to 
standard white paper. Other pigments such as raw umber or yellow oxide can 
also be included to match the tone of colored paper. 
A small amount (0.10-2%) of mustard oil is included as a denaturant. 
A small amount of a fragrance is included in the preferred formula to help 
mask the odor of the solvent. Preferred is Fragrance 759292/602185, which 
is available from Haarmann & Reimer. 
Examples of preferred correction fluids are the following: 
______________________________________ 
Ingredient Wt % 
______________________________________ 
Methylcyclohexane 34.016 
Odorless Mineral Spirits 5.853 
Thermaplastic IBMA Copolymer, 
7.241 
Neocryl B705 Polymer 
Jayflex DTDP Plasticizer, 
2.678 
Ditridecyl Phthalate 
Polymeric Fatty ester 
Hypermer LP1, mfg. by ICI Americas, Inc. 
1.984 
Titanium Dioxide, Tipure R-931 
48.012 
Lamp Black 0.084 
Mustard Oil 0.112 
Fragrance 759292/0602185 0.020 
100.000 
______________________________________ 
EXAMPLE 2 
______________________________________ 
Ingredient Wt % 
______________________________________ 
Methylcyclohexane 28.98 
Dibasic Esters (DBE), mfg. by 
2.59 
DuPont Chemicals 
Isopropyl Alcohol (anhydrous) 
2.59 
Odorless Mineral Spirits 
3.81 
Ground bulk polymeric based on i-butyl 
8.49 
methacrylate Plexigum P28, mfg. by 
Rohm GmbH 
Jayflex DTDP plasticizer 
Ditridecyl Phthalate (DTDP 
2.92 
Titanium Dioxide, 50.40 
Tipure R-931 
Lamp Black 0.09 
Mustard Oil 0.11 
Fragrance 759292/D602185 
0.02 
100.00 
______________________________________ 
EXAMPLE 3 
______________________________________ 
Ingredient Wt % 
______________________________________ 
Paraffin/Naphthene Solvent, Tolu-Sol .TM. 
37.154 
mfg. by Shell Oil Co., Houston, TX 
Odorless Mineral Spirits 5.572 
Thermaplastic IBMA Copolymer, 
6.895 
Neocryl B705 Polymer 
Jayflex DTDP Plasticizer, 
2.550 
Ditridecyl Phthalate 
Polymeric Fatty ester 
Hypermer LP1, mfg. by ICI Americas, Inc. 
1.889 
Titanium Dioxide, Tipure R-931 
45.712 
Lamp Black 0.076 
Mustard Oil 0.130 
Fragrance 759292/0602185 0.022 
100.000 
______________________________________ 
EXAMPLE 4 
______________________________________ 
Ingredient Wt % 
______________________________________ 
Paraffin/Naphthene Solvent, Tolu-Sol .TM. 
38.473 
mfg. by Shell Oil Co., Houston, TX 
Odorless Mineral Spirits 3.858 
Thermaplastic BMA Copolymer, 
7.925 
Elvacite 2044 Polymer 
Jayflex DTDP Plasticizer, 
2.815 
Ditridecyl Phthalate 
Polymeric Fatty ester 
Hypermer LP1, mfg. by ICI Americas, Inc. 
0.834 
Titanium Dioxide, Tipure R-931 
45.881 
Lamp Black 0.078 
Mustard Oil 0.115 
Fragrance 759292/0602185 0.021 
100.000 
______________________________________ 
Correction fluids containing the above ingredients are prepared by first 
dissolving the copolymer in the solvent. Next, the polymeric fatty ester 
dispersant, if used, and titanium dioxide opacifying agent are added and 
the mixture dispersed for 3 hours in a bead mill, after which colorants, 
mustard oil, fragrance, and other ingredients are added to obtain final 
fluid composition. 
Other embodiments are within the claims. For example, in addition to the 
most preferred ingredients the composition may also include various 
additives known to those skilled in the art. These additives are 
incorporated to improved specific properties. These include plasticizers 
to improved dry film adhesion and flexibility, flattening agents to 
control film gloss, flow additives and thickeners to control brushing, 
leveling and settling and pigment extenders to reduce cost. Moreover, 
other dialkyl sodium sulfosuccinates, in particular those with alkyl 
groups having less than 15 or 20 carbon atoms, can be used in place of 
dioctyl sodium sulfosuccinate.