U.S. patent number RE28,531 [Application Number 05/484,315] was granted by the patent office on 1975-08-26 for quick drying road marking composition and method.
This patent grant is currently assigned to Prismo Universal Corporation. Invention is credited to Edward R. de Vries.
United States Patent |
RE28,531 |
de Vries |
August 26, 1975 |
Quick drying road marking composition and method
Abstract
A road marking composition which may be applied to the roadway
and used immediately after deposition by traffic which includes
particular proportions of specific binders, pigments and solvents
of a particular range of pigment volume concentration and solids
content.
Inventors: |
de Vries; Edward R. (Lebanon,
NJ) |
Assignee: |
Prismo Universal Corporation
(Rockville, MD)
|
Family
ID: |
27047951 |
Appl.
No.: |
05/484,315 |
Filed: |
June 28, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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262233 |
Mar 1, 1963 |
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231283 |
Oct 17, 1962 |
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Reissue of: |
606023 |
Dec 30, 1966 |
03474057 |
Oct 21, 1969 |
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Current U.S.
Class: |
523/172; 427/137;
260/998.19; 524/601 |
Current CPC
Class: |
E01F
9/506 (20160201); C08K 3/34 (20130101); C09D
5/004 (20130101); C08K 5/02 (20130101); C08K
3/24 (20130101); C08K 5/00 (20130101); C08K
5/02 (20130101); C08L 67/08 (20130101); C08K
5/00 (20130101); C08L 67/08 (20130101); C08K
3/34 (20130101); C08L 67/08 (20130101); C08K
3/24 (20130101); C08L 67/08 (20130101) |
Current International
Class: |
E01F
9/04 (20060101); C09D 003/64 (); C09D 003/66 () |
Field of
Search: |
;260/22CB,DIG.38
;404/12-14 ;117/105.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Paint Industry Technical Yearbook and Materials Manual, 1959, Vol.
4, published by Heckel Publishing Co., Philadelphia, Pa., pp.
212-223..
|
Primary Examiner: Griffin; Ronald W.
Attorney, Agent or Firm: Cushman, Darby & Cushman
Parent Case Text
The present application is a continuation-in-part of applicant's
application Ser. No. 262,233, now abandoned, filed Mar. 1, 1963,
and entitled "Reflective Marker," which was a continuation-in-part
of application Ser. No. 231,283 filed Oct. 17, 1962, now abandoned.
Claims
What is claimed is:
1. A traffic line paint capable of being sprayed when heated
comprising by weight
said resin binder being selected from the group consisting of short
and medium oil length glycerol or other polyfunctional alcohol
phthalic alkyds having a polyfunctional alcohol phthalate resin
content of 40-58% and an oil content of 60-42%, said low boiling
solvents having a high solvency for the resin binder and a boiling
range below the temperature at which the paint is sprayed, and said
higher boiling solvents having a boiling range between
200-400.degree. F.
2. A traffic line paint according to claim 1 wherein the major
portion of said pigments is selected from the group consisting of
ground silica, natural clay, calcined clay and calcium sulfate
having at least 50% of their particles finer than 5 microns.
3. A traffic line paint according to claim 2 wherein said low
boiling solvent is methylene chloride.
4. A traffic line paint according to claim 3 wherein said resin
binder is a glycerol phthalic alkyd having a glyceryl phthalate
resin content of 40-58% and an oil content of 60-42%.
5. A traffic line paint according to claim 4 wherein said higher
boiling solvent is an aliphatic hydrocarbon, 15% aromatic, IBP
250.degree. F., EP 285.degree. F. and KB 40.
6. A method of applying a traffic line marker which is almost
immediately dry upon deposition comprising pumping a traffic paint
into a closed system under a fluid pressure of about 100-150
lbs./sq. inch, said traffic paint containing a resin binder,
pigments, a higher boiling solvent .Iadd., a pigment volume
concentration from 46-62%, a solids content of 70-85% .Iaddend.and
from 7-23% of a low boiling solvent therein having a high solvency
for the resin binder and a boiling range below the temperature at
which the paint is to be sprayed, heating said paint to a
temperature of about 140-250.degree. F., releasing said heated
paint through a spray orifice, applying auxiliary air pressure to
said sprayed material immediately after leaving said orifice, and
directing said sprayed stream onto a roadway surface.
7. A method according to claim 6 wherein reflectorizing glass
spheres are applied onto said marker immediately after deposition
onto said roadway surface.
8. A method according to claim 6 wherein said traffic paint is in
accordance with claim 1.
9. A traffic line paint according to claim 1 wherein the
proportions of the ingredients are as follows:
10. A traffic line paint according to claim 1 wherein the
proportions of ingredients are as follows:
11. A traffic line paint in accordance with claim 10 having the
following composition:
Description
The present invention relates to reflective markings and more
particularly to a reflective highway marker and composition
therefor, which shows little or no deformation or smearing of the
line by passing vehicles immediately after deposition.
Generally, reflective road markers in the form of traffic paints
are combinations of solvent, resinous binder and pigment supplied
at a viscosity which is suitable for spraying or brushing. These
traffic markers become sufficiently set, to allow traffic to pass
over them without deformation or smearing of the line, by
evaporation of the solvent alone and subsequent polymerization of
the resinous binder by oxidative processes. Some traffic paints set
sufficiently by evaporation of solvent only; however, these types
use solutions of hard resinous binders which require more solvent
to be used to obtain the desired viscosity. This greater solvent
volume is often more slowly released from such resins. Both types
of these materials require from 15 to 60 minutes before traffic can
be safely allowed to run over the markings. This requires the
placement of protective markers and later collecting them. This not
only seriously restricts traffic flow but adds considerably to the
cost of such marking.
Many attempts have been made to reduce the time required before the
freshly applied markings could be opened to traffic. The most
successful of these involved heating the material to the
neighborhood of 160.degree. F. just before application. This
allowed the use of less solvent in the base material since the
higher temperature had the effect of reducing the viscosity as
required for successful application. The lower solvent content
yielded a more rapid development of no smear characteristics;
however, not so rapid as to obviate the use of the protective
cones. The minimum time for no smear achieved by this method was 3
to 5 minutes; however, this is achieved only under ideal
conditions, i.e. warm, dry day and using thin films. At normal film
thickness as required for reasonable durability (approximately 15
mils wet), at least 15 minutes are required for "track free`
conditions under ideal weather conditions by this technique.
A further serious shortcoming of the above, traffic paints,
regardless of their composition, is their prolonged time to achieve
"track free" condition at night. This is important since areas
which are heavily travelled in daytime need to be marked at night
to prevent disastrous traffic tie-ups. Protection of the line for
long periods at night is difficult and dangerous due to more
limited visibility.
It is therefore an object of the present invention to provide a
line marking method and composition which enables traffic to pass
over the sprayed lines almost immediately after deposition without
pick-up, deformation or smearing of the lines regardless of the
weather conditions with the single exception of wet surfaces.
It is a further object of the present invention to provide a hot
spray quick drying traffic paint.
It is yet another object to provide a composition which can be
sprayed on the road in thicker layers and yet will be immediately
dry to no track regardless of the weather conditions with the
single exception of wet surfaces.
Other objects and the nature and advantages of the instant
invention will be apparent from the following description.
It has now been found that traffic paints which meet the above
requirements can be prepared by the use of specific ingredients for
the solvent, binder and pigments using relatively narrow critical
limits of these materials to obtain the desired pigment volume
concentration and solids content. The resulting traffic paint when
applied according to the method of the present invention will
achieve the desired objectives.
The compositions according to the present invention have the
following ingredients:
Percent by weight Binders 12-22 Pigments 50-69.4 Solvents (low
boiling) 7-23 Solvents (higher boiling) 5-20 Pigment volume
concentration 46-62 Solids content 70-85
The preferred range of ingredients in the compositions as can be
verified by the examples in this application is as follows:
Percent by weight Binders 14.0-21.7 Pigments 50.8-69.4 Solvents
(low boiling) 7.1-16.1 Solvents (higher boiling) 8.2-18.5 Pigment
volume concentration 46.7-60.1 Solids content 71.3-83.9
The resins which are suitable as binders in the composition are
preferably glycerol or other polyfunctional alcohol phthalic alkyds
of short and medium oil length which have a polyfunctional alcohol
phthalate resin content of 40-58% and an oil content of 60-42%.
When using medium oil length alkyds having a polyfunctional alcohol
phthalate resin content up to 51.6%, the oils should be selected
from a group including linseed, tung, dehydrated castor and
oiticica or soybean. Shorter oil lengths of over 51.6% glyceryl
phthalate resin content can be based wholly on soybean oil due to
the lower oil content. When higher concentrations of oil are
present it has been found that soybean oil is not sufficiently
conjugated and as a result the composition does not dry quickly
enough. The alkyds can be modified with up to 20% by weight of
certain hydrocarbon resins or with phenol to make phenolated
alkyds. It has also been found that a short oil epoxy ester resin
having an acid number less than 2 is also suitable for use as a
binder. Short oil urethane esters have also been found to be
suitable and to dry in a similar manner to the alkyds. Benzoic acid
condensations with polyfunctional alcohols can also be formulated
to give suitable results; however, such systems are somewhat
brittle. Styrene butadiene or vinyl toluene-butadiene copolymers
represent a binder which dries by solvent evaporation only which is
useful in connection with this invention; however, it must be used
without the chlorinated plasticizers normally associated with these
resins since such plasticizers affect solvent release properties
adversely.
The solvents used are a combination of a low boiling and a higher
boiling solvent. The lower boiling solvent or combination of
solvents has its boiling range below the temperature at which the
material is to be sprayed. This solvent or solvent combination is
prevented from evaporating or boiling due to the pressure in the
system. Upon release of the pressure at the spray orifice this
solvent is largely flashed out in the form of vapor. This flashing
out of the solvents results in (a) breaking up the material in the
form of fine droplets due to the sudden boiling out of this solvent
component, (b) cooling the remaining material rapidly due to the
loss of the heat of vaporization as well as the heat absorbed by
the expanding atomizing air, and (c) increasing the consistency of
the material to a consistency approaching a track free state before
it hits the surface due to the cooling effect and the loss of the
low boiling, high solvency, solvent. The other important function
of this solvent or solvent combination is to reduce the viscosity
of the resin-pigment combination so that it can be pumped from its
container with available equipment while maintaining its high
solids content. The required characteristics of this part of the
solvent in the composition are: (a) high solvency for the resins
used and (b) boiling point(s) below the spraying temperature.
Suitable solvents are cyclohexane, pentane, petroleum ether,
iso-hexane, hexane, methylene chloride, chloroform, carbon
tetrachloride, ethylene dichloride, trichloroethylene, acetone,
methyl ethyl ketone, ethyl acetate, isopropyl acetate, benzene and
the like. The preferred solvents are those that are chlorinated
because of their high or lack of flash point. Of these methylene
chloride is the most satisfactory because of its low toxicity, low
boiling point and rapid reduction of viscosity of most resins.
The second portion of the solvent or solvent combination has the
function of providing sufficient tack and flow to the pigment resin
combination after it reaches the road surface to (a) adhere to the
surface on which it is applied, (b) incorporate and bind to glass
spheres which may be added to obtain night visibility, and (c) from
a smooth continuous line. This solvent should also be such that it
will evaporate from the line marker quickly. This is accomplished
by using a fair to poor solvent for the resin and one which has a
preferred boiling range between 200.degree. F. and 300.degree. F. A
portion may have a boiling point as high as 400.degree. F. if it is
very poor solvent for the resin. For example, if the resin is a
medium oil phthalic alkyd (47% glyceryl phthalate, 53% oil) the
solvent should be a mixture of aliphatic hydrocarbons within the
boiling range containing not more than 20% aromatic hydrocarbons
and a kauri-butanol value of less than 50. Shorter oil phthalic
alkyds (57% glyceryl phthalate, 43% oil), epoxy esters and the like
can be used with aromatic solvents within the boiling range, such
as toluene or xylene, since such binders require higher K-B
solvents for solution.
The third basic part of the composition, the pigmentation, is also
critical with respect to the achievement of the objects of the
invention. This is particularly true with respect to the extenders
or low refractive index pigments. The pigments which are suitable
for developing the opacity and/or color to the marking material are
the same as those traditionally used in such markers, i.e. rutile
and anatase titanium dioxide, chrome yellow (lead chromate), carbon
black, and the like. The pigments used of this type should be free
of any treatment designed to improve the dispersion characteristics
of the pigment since such treatments were found to adversely affect
the "no track" time in compositions of this invention. The
composition of this invention requires that the major portion of
the volume of the pigmentation be one or a combination of ground
silica, natural clay, calcined clay, and calcium sulfate. Further,
the silica must have at least 50% of its particles finer than 3
microns with at least 80% of its particles within 5 microns of size
distribution. The natural and calcined clays should have at least
50% of their particles finer than 5 microns. Calcium sulfate
pigments should be at least 80% within a range of 0.4 to 0.8
microns. Generally, the most suitable pigments are those which are
not strongly wetted by the binder and which have their average
particle size in the vicinity of 1.5 microns. Pigments
significantly finer than this have such high oil adsorption that
they require such high binder and solvent concentrations that their
"no track" time does not meet the objectives of this invention as
the major pigment component. Coarser and more easily wet pigments
also do not meet the requirements regardless of other formulation
variables. Other types of extender (low refractive index) pigments
can be used in small quantities providing the above pigments
represent at least 50% of the total volume of the pigment.
Representatives of these other types are calcium carbonate
(whiting), magnesium silicate (talc), mica, and the like.
These pigments contribute importantly to this invention in that
they are of a size, shape and have surface characteristics such
that when in close proximity to each other they developed high
dilatancy and microporosity. Thus, when deposited on the substrate
with little solvent remaining in the material, a passing wheel will
impart a force which causes the apparent viscosity of the system to
be extremely high. Further, its microporous structure allows the
remaining solvent to escape rapidly. Calcined clays give the best
results because their cinder-like particles tend to lock together
when they are in close proximity and under stress.
Each specific pigment combination has a corresponding optimum
pigment volume concentration. Below this level the time for no
tracking characteristics increases rapidly and above this optimum
the durability characteristics shows rapid deterioration, loss of
adhesion, inability to hold glass spheres used as retroreflective
elements, and dirt penetration into the film due to excessive
porosity. The "no track" time for these systems is determined by
casting a 15 mil wet film of the composition and testing by the
method described in A.S.T.M. Designation 711-55. A result of 6
minutes or less by this test will generally have a no track time of
one minute or less when applied and compounded according to the
teachings of the invention. Examples of the variation of "no track"
time with pigment volume concentration of some pigments with a
fixed volume of hiding pigments in a representative binder as
described in the invention are given below:
These examples illustrate the characteristics of those pigments
which are suitable for use in this invention compared with those
which are unsatisfactory.
Pigment Volume Concen- No tration, Track Pigment percent Time
______________________________________ Silica-1.5 microns 50 11 55
7 60 5 65 4 70 3 Silica-10 microns 50 28 55 22 60 22 65 20 70 17
Magnesium silicate-5 microns 50 17 55 15 60 10 65 15 70 20 Calcium
carbonate-5 microns 50 30 55 23 60 18 65 15 70 15 Calcined clay-1.5
microns 35 12 40 8 45 7 50 5 55 3 60 1
______________________________________
The composition in accordance with the present invention is handled
for application by first pumping the material directly from its
container into a closed system maintained at a fluid pressure of
100 to 150 pounds per square inch. The material is passed through a
heat exchanger and heated lines. This increases its temperature to
a range between 140.degree. F. to 250.degree. F. The most practical
temperature was found to be 160.degree. F..+-.10.degree. F. The
heated material is then released from a spray orifice and is
further broken up by auxiliary air pressure.
The preferred viscosity of the composition of this invention should
be as high as practical. The higher the viscosity the higher the
solids of the composition and the closer it is to its no track
state. A practical limitation of handling the composition in cold
weather is viscosity. The minimum viscosity found which would allow
the desired results to be obtained is approximately 80 Krebs
units.
The following specific examples of formulations in accordance with
this invention are illustrative only and should not be construed as
limiting the scope of the invention.
EXAMPLE 1
Percent Material: by weight Binder-Glycerol-phthalic alkyd (47%
glyceryl phthalate-53% oil) (oil-75% soya-25% Chinawood) 17.1
Pigments: Rutile titanium dioxide 9.9 Calcium sulfate (0.6 micron)
23.0 Ground silica (1.5 micron) 26.3 Magnesium silicate (talc) 3.3
Solvents: Aliphatic hydrocarbon (15% aromatic, IBP 250.degree.F.,
EP 285.degree.F., KB 40) 9.4 Methylene chloride 9.4
Additives-Driers and additives 0.5
This formulation yielded a white paint having a pigment volume
concentration of 58.3 and a solids content of 80.1%.
EXAMPLE 2
Percent Material: by weight Binder-Glycerol-phthalic alkyd (47%
glyceryl phthalate-53% oil) (oil 75% soya-25% Chinawood) 17.7
Pigments: Chrome yellow medium (lead chromate) 10.2 Ground silica
(1.5 micron) 47.6 Magnesium silicate (talc) 3.4 Solvents: Aliphatic
hydrocarbon (15% aromatic, IBP 250.degree.F., EP 285.degree.F., KB
40) 10.9 Methylene chloride 9.7 Additives-Driers and additives
0.5
This formulation yielded a yellow paint having a pigment volume
concentration of 56.7 and a solids content of 79.4%.
EXAMPLE 3
Percent Material: by weight Binder-Glycerol-phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (oil-75%
soya-25% Chinawood) 16.9 Pigments: Carbon black (pigment grade 1.6
Ground silica (1.5 microns) 52.0 Magnesium silicate (talc) 6.5
Solvents: Aliphatic hydrocarbon (15% aromatic, IBP 250.degree.F.,
EP 285.degree.F., KB 40) 10.4 Methylene chloride 12.2
Additives-Driers and additives 0.4
This formulation yielded a black paint having a pigment volume
concentration of 60.1 and a solids content of 77.4%.
EXAMPLE 4
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 18.0 Pigments: Rutile titanium dioxide 10.4
Calcium sulfate (0.6 micron) 24.3 Natural clay 24.3 Magnesium
silicate 3.5 Solvents: Aliphatic hydrocarbon (15% aromatic, IBP
250.degree.F., EP 285.degree.F., KB 40) 10.5 Methylene chloride 8.4
Additives-Driers and additives 0.6
This formulation has a pigment volume concentration of 56.7% and a
solids content of 81.1%.
EXAMPLE 5
Percent Material by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 18.0 Pigments: Rutile titanium dioxide 10.4
Natural clay 48.6 Magnesium silicate 3.5 Solvents: Aliphatic
hydrocarbon (15% aromatic, IBP 250.degree.F., EP 285.degree.F., KB
40) 10.5 Methylene chloride 8.4 Additives-Driers and additives
0.6
This formulation has a pigment volume concentration of 58.0% and a
solids content of 81.1%.
EXAMPLE 6
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 21.7 Pigments: Rutile titanium dioxide 15.2
Calcined clay (1.5 microns) 35.6 Solvents: Aliphatic hydrocarbon
(15% aromatic, IBP 250.degree.F., EP 285.degree.F., KB 40) 15.7
Methylene chloride 11.0 Additives-Driers and additives 0.8
This formulation has a pigment volume concentration of 46.7% and a
solids content of 73.3%.
EXAMPLE 7
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 19.8 Pigments: Rutile titanium dioxide 13.8
Calcined clay (1.5) microns) 41.5 Solvents: Aliphatic hydrocarbon
(15% aromatic, IBP 250.degree.F., EP 285.degree.F., FB 40) 14.2
Methylene chloride 10.0 Additives-Driers and additives 0.7
This formulation has a pigment volume concentration of 51.6% and a
solids content of 75.8%.
EXAMPLE 8
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 19.8 Pigments: Rutile titanium dioxide 13.8
Natural clay 41.5 Solvents: Aliphatic hydrocarbon (15% aromatic,
IBP 250.degree.F., EP 285.degree.F., KB 40) 14.2 Methylene chloride
10.0 Additives-Driers and additives 0.7
This formulation has a pigment volume concentration of 51.9% and a
solids content of 75.8%.
EXAMPLE 9
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) (10%
Chinawood-90% soya) 20.0 Pigments: Rutile titanium dioxide 11.6
Natural clay 40.9 Magnesium silicate 3.9 Solvents: Aliphatic
hydrocarbon (15% aromatic, IBP 250.degree.F., EP 285.degree.F., KB
40) 11.7 Methylene chloride 11.3 Additives-Driers and additives
0.6
This formulation has a pigment volume concentration of 52.5% and a
solids content of 77.0%.
EXAMPLE 10
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalate-53% oil) (10% Chinawood-90% soya) 18.6 Pigments:
Rutile titanium dioxide 11.9 Natural clay 42.2 Magnesium silicate
4.0 Solvents: - Aliphatic hydrocarbon (15% aromatic, IBP
250.degree.F., EP 285.degree.F., KB 40) 10.0 Methylene chloride
10.6 Additives: Coumaron-indene hydrocarbon resin modifier (M.P.
200-220.degree.F., iodine value 230 heat re- active Sap. No. 0-2
Acid No. 0-2) 2.1 Driers and additives 0.6
This formulation has a pigment volume concentration of 55.0% and a
solids content of 79.4%.
EXAMPLE 11
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalate-53% oil) (10% Chinawood-90% soya) 17.1 Pigments:
Rutile titanium dioxide 12.3 Natural clay 43.5 Magnesium silicate
4.1 Solvents: Aliphatic hydrocarbon (15% aromatic, IBP
250.degree.F., EP 285.degree.F., KB 40) 9.2 Methylene chloride 8.8
Additives: Coumaron-indene hydrocarbon resin modifier M.P.
200-220.degree.F., iodine value 230 heat re- active Sap No. 0-2
Acid No. 0-2) 4.3 Driers and additives 0.7
This formulation has a pigment volume concentration of 57.8 and a
solids content of 82.0.
EXAMPLE 12
Percent Material: by weight Binder-Glycerol phthalic alkyd (57%
glyceryl phthalate-43% soya oil) 19.0 Pigments: Rutile titanium
dioxide 10.9 Natural clay 38.6 Magnesium silicate 3.6 Solvents:
Xylene 12.6 Methylene chloride 14.7 Additives-Driers and additives
0.6
This formulation has a pigment volume concentration of 53.2 and a
solids content of 72.7.
EXAMPLE 13
Percent Material: by weight Binder-Glycerol phthalic alkyd (50%
glyceryl phthalate-50% dehydrated castor oil) 18.5 Pigments: Rutile
titanium dioxide 10.7 Natural clay 37.8 Magnesium silicate 3.6
Solvents: Aliphatic hydrocarbon (15% aromatic, IBP 250.degree.F.,
EP 285.degree.F., KB 40) 18.5 Methylene chloride 10.2
Additives-Driers and additives 0.7
This formulation has a pigment volume concentration of 51.6 and a
solids content of 71.3.
EXAMPLE 14
Percent Material: by weight Binder-Glycerol phthalic alkyd (48%
glycerol phthalate-52% linseed oil) 18.5 Pigments: Rutile titanium
dioxide 10.7 Natural clay 37.8 Magnesium silicate 3.6 Solvents:
Aliphatic hydrocarbon (15% aromatic, IBP 250.degree.F., EP
285.degree.F., KB 40) 18.5 Methylene chloride 10.2 Additives-Driers
and additives 0.7
This formulation has a pigment volume concentration of 54.6 and a
solids content of 71.3.
EXAMPLE 15
Percent Material: by weight Binder-Glycerol phthalic alkyd (50%
glyceryl phthalate-50% DCO) (dehydrated castor oil) 18.5 Pigments:
Rutile titanium dioxide 10.7 Natural clay 37.8 Magnesium silicate
3.6 Solvents: Aliphatic hydrocarbon (15% aromatic, IBP
250.degree.F., EP 285.degree.F, KB 40) 18.5 Methylene chloride 10.2
Additives-Driers and additives 0.7
This formulation has a pigment volume concentration of 54.6 and a
solids content of 71.3.
EXAMPLE 16
Percent Material: by weight Binder-Glycerol phthalate alkyd (47%
glyceryl phthalate-53% oil) (10% Chinawood-90% soya) 14.0 Pigments
Rutile titanium dioxide 8.1 Natural clay 28.5 Magnesium silicate
2.7 Glass spheres (-45 mesh) 30.1 Solvents: Aliphatic hydrocarbon
(15% aromatic, IBP 250.degree.F, EP 285.degree.F, KB 40) 8.2
Methylene chloride 7.9 Additives-Driers and additives 0.5
This formulation has a pigment volume concentration of 52.4 and a
solids content of 83.9.
EXAMPLE 17
Percent Material: by weight Binder-Short oil epoxy ester having
acid number no greater than 1 (70% epoxy-30% oil) (M.P.
130.degree.C.) 15.3 Pigments Rutile titanium dioxide 9.1 Ground
silica (1.5 microns) 24.4 Calcium sulfate (1.5 microns) 21.3
Magnesium silicate 3.0 Solvents: Toluene 10.2 Methylene chloride
16.1 Additives-Driers and additives 0.6
This formulation has a pigment volume concentration of 59.4 and a
solids content of 73.7.
EXAMPLE 18
Percent Material: by weight Binder-Glycerol phthalic alkyd (47%
glyceryl phthalate-53% oil) (10% Chinawood-90% soya) 20.9 Pigments
Rutile titanium dioxide 10.9 Calcium sulfate (0.6 microns) 25.3
Calcined clay (1.5 microns) 24.1 Solvents: Aliphatic hydrocarbon
(15% aromatic, IBP 250.degree.F., EP 285.degree.F., KB 40) 11.3
Methylene chloride 7.1 Additives-Driers and additives 0.4
This formulation has a pigment volume concentration of 48.1 and a
solids content of 81.6.
EXAMPLE 19
Percent Material: by weight Binder-Phenolated alkyd (40% phthalic
anhy- dried-4% soya oil) (MIL R-15190A) 16.4 Pigments Rutile
titanium dioxide 8.9 Calcium sulfate (0.6 microns) 20.8 Ground
silica (1.5 microns) 26.5 Magnesium silicate 3.3 Solvents:
Aliphatic hydrocarbon (15% aromatic, IBP 250.degree.F., EP
285.degree.F., KB 40) 16.4 Methylene chloride 7.3 Additives-Driers
and additives 0.4
This formulation has a pigment volume concentration of 58.5 and a
solids content of 76.3.
After the composition in accordance with the previous examples has
been sprayed onto the roadway, glass beads can be immediately
dropped onto the paint while it is still tacky so that the beads
become partially embedded in the paint and it yields a line that is
immediately retroreflective. The higher boiling solvent retards the
setting up of the paint until it has reached the road and the glass
beads have been dropped in.
Traffic can pass over the lines of the present invention within 1
to 2 minutes of being sprayed without any smearing or deformation
of the lines. This differs from the prior systems due to the fact
that in the prior systems as long as even fairly small percentages
of solvent are retained the consistency of the film deposited is
not stiff enough to let traffic pass over, even though the surface
is dry to touch due to so-called skinning over. It is exactly the
skinning over effect that traps solvent in the film and prevents
any further reduction in drying time regardless of decreased
solvent content and increased temperature. This is not true in the
present invention which evaporates most solvent before deposition
and in which the binder has a high consistency during
deposition.
It will be obvious to those skilled in the art that various changes
may be made without departing from the scope of the invention and
the invention is not to be considered limited to what is described
in the specification.
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