Note: Descriptions are shown in the official language in which they were submitted.
11137~0
This application is a divisional of S.N. 304,687, filed June 2, 1978,
and is directed to the preparation of polymer bonded concrete using in situ
polymerization of methyl methacrylate monomer, while the parent is directed to
the preparation of polymer bonded concrete using in situ polymerization of
unsaturated polyester resin in excess of specific monomers.
This invention relates to polymer concretes. More particularly,
it relates to polymer concretes having very low polymer binder leve]s.
Concretes manufactured with synthetic organic binders are known,
the binders generally being resins of the epoxy, polyester and melamine-
formaldehyde types. These non-hydraulic concretes have superior properties
once the binders are cured and fused with the inorganic components to produce
a hardened mass. They are used in the production of precàst elements for
architectural or engineering applications or for cast-in-place uses, where
strength, water- and chemical-resistance or speed of cure are desirable.
A catalyst is generally added to the resinous component immediately before
casting, the catalyzed resin is then added to the inorganic component and the
resulting mix is placed in forms. Curing normally requires about 1 to 4 hours
in the case of polyester binders.
Although polymer bonded concretes are now well-known, there are
some major drawbacks to the use of them. These drawbacks are high cost,
low modulus of elasticity, poor fire resistance, limited surface effects that
can be achieved for architectural purposes, high shrinkage on curing resulting
in curling or cracking, high exothermic reaction on curing leading to internal
stresses and poor processibility due to the viscous nature of the liquid
phase used. All these disadvantages are the result of one difficulty and that
is the inability to reduce the organic binder component below a level of about
10-15 percent by weight of the concrete without causing other serious problems
such as low compressive and tensile strengths, poor resistance to wear and
sensitivity to impact.
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11137~)0
The use of low polymer binder levels in different types of
compositions containing inorganic solids is known. For example, U.S. Patent
2,991,267 discloses a granular material for use in making molds for metal
casting. Sand is coated with a thermosetting resin such as a phenol-
formaldehyde or melamine-formaldehyde type and in order to obtain satisfactory
binder distribution on the sand, the coating is carried out using a volatile
solvent, a
.
.
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11137QO
slurry of the binder in a non-solvent or adherence of powdered binder to
moistened sand. The arlounts of binder necessary are disclosed as one half to
five percent by weight. When the mold is prepared, coated sand of different
grades is used and vibrated to ensure packing and heat or other treatment is
then used to effect curing of the binder. Although very low resin amounts are
disclosed, this reference is not helpful in respect of polymer concretes and
decreasing the resin binder levels therein, in that foundry molds are very
porous articles and the strength considerations are not at all similar.
U.S. Patent 3,070,557 discloses aggregates and fillers bonded
with polymers, which compositions are primarily intended to serve as paving
compositions of the asphalt type. Although other uses are suggested for
compositions no data are given as to strength measurement`s which would be
of importance given the type of organic binders being used. The polymeric
binders are high molecular weight linear thermoplastic polymers having cer-
tain specific characteristics such as low softening point, being substantially -
uncrosslinked, melt viscosity of 100 - 30,000 cps and the like. Examples of
the binders are polyolefins principally, and copolymers thereof. The
proportions of the binder used are disclosed as l - 10% by weight of solid,
preferably 2 - 8%. The method of application favored is hot plastic mixing,
o wherein the polymer is heated to 100 - 300F above its softening point and
the inorganic solids are then mixed therewith. Even at those temperatures,
the polymeric binder still has significantly high viscosity. This reference
also is not of help in decreasing the level of the binders used in polymer
~concretes where high strength properties are required.
In fact, attempts have been made with polyester type concretes
to mix the binder with the inorganic solids using a low level of binder by
first heating the resin in order to reduce its viscosity. Theoretically
this would enable mixing of low amounts of binder with the inorganic solids
and still provide proper distribution throughout the composition. However,
addition of catalyst, fillers, and sand on a continuous basis is required
because of the increased reactivity of the heated resin. This necessitates
complex machinery and results in relatively low delivery rates. Further-
more, the viscosity reduction of the binder even on heating is not enough
'137~)
to achieve substantially lower resin levels.
Another reference wherein low binder levels are used with
inorganic solids is U.S. Patent 3,243,388 which relates to a plastic bonded
concrete. However, although low binder levels are suggested the reference is
concerned with compositions wherein the spaces between the mineral aggre-
gates contain closed cell expanded or foamed plastics. Thermoplastic or
thermosetting foamable resins are used and polymerization and foaming is
carried out in the mold once the inorganic material has been mixed with
the ingredients. Generally polyurethane and polystyrene foams are
illustrated. This type of "concrete" is a very light-weight material and
the strength characteristics as compared to polymer concretes using non-
foamed resins are completely differènt. Thus this reference is also not of
help in enabling reduction of binder levels in high strength polymer concretes.
The coating of inorganic materials with polymer by means of poly-
merization of monomers carried out in the presence of the solids is known.
An example is U.S. Patent 3,971,753 but this patent does not deal with
polymer bonded concrete but rather with fillers to be incorporated in polymer
compositions. It has nothing to do with the problems attendant on attempt-
ing to lower the total polymer content of a polymer bonded concrete.
The specific problem of binder level in polymer bonded concretes
has been dealt with in U.S. Patent 3,801,536. This reference discloses that
the viscosity of the polymeric binder, i.e. epoxy or polyester resin, for
use with various aggregates and fillers can be affected by the use of a
micronic inorganic filler having particle size below two microns and high
shape regularity. This material is used in an amount of about 25 - 75% by
weight of the binder and enables reduction of the proportion of resin in
the eventual composition, but with proper distribution of the binder through-
out the other solid materials. The micronic material apparently most
suitable and particularly illustrated is titanium dioxide, especially a
mixture of anatase and rutile, although iron oxides are also suggested. The
references discloses that with this material the amount of resin which can be
111370()
used in the case of polyester resins is lowered to 7 - 13% by weight of
the composition and 2 - 7% by weight with epoxy resins. The main dis-
advantage to the use of this method of lowering binder levels in polymer
concrete is that the micronic fillers required are 2 to 4 times as expensive
as the resin binder by volume. These cost considerations mitigate against
the use of these materials.
It hss now been found that very low binder levels in polymer
bonded concrete can be achieved by a completely different method. This is
done by mixing certain monomeric materials with the inorganic components
rather than only formed polymers or prepolymers as binder, together with
polymerization initiator and allowing polymerization to occur as the setting
process. The exceptionally low viscosity bf the liquid pfiase permits the
mixing in of enough sand, fillers, and aggregates to obtain binder levels of
5 - 10% by weight and as low as 3%.Optimum distribution of the binder material
and resultant strength of the concrete product is also aided by intense
vibration of the mixed components to obtain maximum packing of the solids
either before or during the setting process. Setting is accelerated or
initiated by the application of heat, use of promotors and the like.
Thus, the present invention provides a polymer concrete having
high strength characteristics comprising an aggregate consisting of sand,
stone or gravel or mixtures thereof and an organic binder in an amount ofabout
3 to about 10% by weight of said concrete, said organic binder consistin~ of
polymer formed in situ from one or morec~, ~-ethylenically unsaturated
monomers of the group of styrene, styrene derivatives, Cl-8 alkyl esters-of
acrylic or methacrylic acids, and divinyl benzene, or a low viscosity solution
of an unsaturated polyester in said monomers, said solution containing
monomer in excess of that required for cross-linking the polyester.
The invention also provides a process for the preparation of
a polymer bonded concrete of low binder content which comprises
(1) mixing an aggregate consisting of sand, stone, or gravel or
mixtures thereof with~ as binder components,
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" ~
a) one or more ~ ethylenically unsaturated monomers of the group of
styrene, styrene derivatives, Cl 8 alkyl esters of acrylic or methacrylic acids,
or divinyl benzene, or an unsaturated polyester dissolved in one or more of said
monomers, the solution of monomer and polyester being of low viscosity and con-
taining monomer in excess of that required for cross-linking purposes, and
b) a free radical polymerization initiator,
to form a mixture of said aggregate with said binder component.s;
(2) casting said mixture;
. (3) subjecting said mixture to intense vibration to pack solids
therein to occupy the minimum possible volume; and
(4) allowing said monomers to polymerize and set to produce said
polymer bonded concrete.
In more particular aspects, the invention provides a process for the
preparation of a polymer bonded concrete containing from 3 to less than 10~ of
organic binder material, which process comprises:
(1) mixing an aggregate consisting of sand, stone or gravel or
mixtures thereof with binder components comprising
(a) an unsaturated polyester resin dissolved in styrene monomer,
the solution being of low viscosity and containing additional monomer in excess
of that required for cross-linking of the polyester, the additional monomer
~eing selected from the group styrene, methyl methacrylate and butylacrylate,and
(b) a free radical polymerization initiator,
to form a mixture.of the aggregate and the binder components;
(2) casting the mixture;
(3) subjecting the mixture to intense vibration to pack solids
therein to occupy the minimum possible volume and substantially eliminate voids;
and
(4) causing the monomers to polymeri7.e by the application of heat
-- 5
11137QO
.
to produce the polymer bonded concrete;
and a process for the preparation of a polymer bonded conerete contain-
ing from 3 to less than 7% of organie binder material, which process comprises:
tl) mixing an aggregate consisting of sand, stone or gravel or
mixtures thereof with binder components comprising
(a) methyl methacrylate monomer, and
(b) a free radical polymerization initiator,
to form a mixture of the aggregate and the binder components;
(2) casting the mixture;
(3) subjecting the mixture to intense vibration to pack solids therein
to occupy the minimum possible volume and substantially eliminate voids, and
(4) causing the monomers to polymerize by the application of heat to
produce the polymer bonded concrete.
The ability to use monomers and in situ polymerization (not only a
cross-linking process) to obtain a polymer bonded concrete of superior properties
is eompletely unexpected. One would expect high shrinkage to oeeur as the mono-
mers used inherently shrink far more during polymerization than occurs during
curing of, for example, a polyester resin used alone as binder. For instance,
the shrinkage that occurs in polymerization of methyl methacrylate to polymethylmethacrylate is 20-22%. In fact, however, when the method according to the
present invention is used, the retraction of the concrete is less than occurs
in the preparation of conventional polymer bonded concretes. Furthermore, the
stress cracking that is normally associated with the exotherm produced by the
curing of high-resin concretes is absent. The concrete also "places" better thanhydraulie conerete, allowing easting in molds as thin as ~-ineh. Furthermore,
standard eonerete mixing and plaeing equipment may be used.
Beeause of the decreased levels of binder which may be used in the
concrete according to the present invention, the total cost of the conerete often
can be halved with no untoward effeets on mechanical properties. For
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example,, a formulation containing 3.5 percent unsaturated polyester
dissolved in styrene (72:28) by weight), 3.1 percent methylmethacrylate,
0.08% initiator and 93% graded silica fillers, sand and aggregates has
provided a concrete of 2750 p.s.i. in flexion, 13,500 p.s.i. in compression
strength, having resistance to at least 50 cycles of freeze and thaw and
absorbing 0.1% water. The modulus of elasticity, 6.6 X 10 , is at least
twice as high as that of conventional polyester bonded concretes. The
weathering resistance is also improved in that a concrete such as aforemention-
ed exhibited no changed in appearance after 2500 hours in a weatherometer.
The binder is the only flammable component in polymer bonded
concretes and as according to the present invention the proportion of the
binder component is considerably reduced, the fire resistahce is greatly
improved. Furthermore, replacement of conventional fillers of smaller size
with certain materials even further improves the fir resistant properties
as will be detailed later herein.
The aggregates which can be used in the present process are
sands, stone and gravel which are normally used for making concrete with
hydraulic binders. The aggregates may be screened or crushed, preferably
with not too many fines.
Fillers which are comminuted solids can be added to the actual
aggregates as granulated material of particle size less than the aggregates.
Silica is advantageously used because of its low price, low porosity and
relatively great hardness. Examples of suitable types of silica are silica
flour and Ottawa silica. Also among fillers which may be used are treated
and untreated calcium carbonates. The percentage of the filler or extender
which is used is determined for any given aggregate by a technique analagous
to that used in the production of hydraulic cements and mortars. It consists
for a given aggregate in testing various proportions of aggregates and extend-
er in a system of the binder composition of interest. The quantity of the
extender chosen will be that which corresponds substantially to the maximum
` ` 11137~)0
of resistance to compression and of flexion. The fillers mentioned are not
intended to be limiting as any fillers known in the ar~. of concrete manu-
facture may be used.
Other materials may be added, as for example titanium dioxide
or iron oxides or other materials for pigmentation.
It has been found that by replacement of smaller size fillers
(e.g. 44 - 220 microns) with certain compounds, fire retardancy of the
products is greatly increased over and above that achieved by reduction
in the amount of binder used. These compounds may be any powdered sub-
stance which releases water of crystallization at high temperatures as
for example alumina trihydrate, ericalcium aluminate hexahydrate and
zinc borate. The amount of such materials which is requi~ed to provide
maximum fire retardancy is in general about twice the amount of resin
binder that is used. Thus in the conventional polymer concretes pro-
hibitive amounts of these materials must be used, but with the concretes
according to the present invention having low polymer binder content there
is a corresponding decrease in the amount of fire retardant compound
which is necessary to obtain maximum retardancy. Generally levels of
20 - 200~ by weight based on binder greatly improv~s fire resistance of
the concrete.
It has already been indicated that the monomers which may be
used to form the binders according-to the present invention are ~ ethylen-
ically unsaturated monomers, i.e. styrene and styrene derivatives, divinyl
benzene and Cl-8 alkyl esters of acrylic and methacrylic acids. Examples
of these monomers are styrene itself, lower alkyl substituted styrenes as
for instance ~ -methyl styrene and vinyl toluene, divinyl benzene, methyl
acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, 2-ethylhexyl
acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate,
butyl methacrylate and the like. These monomers may be used alone or in
3~ comtinaeion :nd ehe preferred monomers, ~articularly from the poiDt of v:eu
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of cost, are styrene, methyl methacrylate and butyl acrylate. Suitably,
others of the monomers may be combined with the preferred monomers to
modify the proper~ies of the binder and as such can be used in minor
amounts.
Also other monomers in addition to those mentioned and cross-
linking agents may be included in relatively low proportions to alter
properties of the binder, as for instance to improve adhesion or increase
glass transition temperature. Examples of these monomers and cross-
linking agents are acrylic acid, methacrylic acid, 1,3-butylene dimeth-
acrylate, trimethylolpropane trimethacrylate, diethyl phthalate, dibutyl
phthalate and diallyl phtllalate.
The foregoing monomers can be used as such or can be used to
dissolv~ a certain proportion of unsaturated polyester. These unsaturated
polyesters are condensation products of polyalcohols and unsaturated
dibasic acids and are general purpose medium reactive resins conventionally
used in the polymer concrete and fibre glass fields as binders. Examples
are Palatal*H-170 (obtainab]e from BASF Canada Ltd) and Laminac* 4193 (ob-
tainable from Cyanamid of Canada which are unsaturated polyester resins
dissolved in styrene, there being incorporated in the resin about 1 part
of maleic anhydride for every 2 parts of styrene. Paraplex* P-444A
(obtainable from Rohm & Haas Company Canada Ltd.) is a similar suitable
unsaturated polyester.
It is known to add material such as styrene to unsaturated
polyester resins and in fact they are supplied by chemical suppliers
diluted with sufficient styrene for eventual cross-linking of the polyester.
The proportions supplied are usually about 70 parts by weight polyester
to 30 parts by weight styrene. The viscosity of such diluted resins is
still far greater than 1000 cps. By the further dilution according to
the present invention with monomers as aforementioned viscosities of
3Q perhaps 50 cps down to less than 1 cps are obtained. Such diluted polyesters
~': Trade ~larh
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provide more monomer than is required for cross-linking of the polyester
and when used according to the present invention polymerization of that
monomer occurs as well as the cross-linking reaction. Obviously when
an unsaturated polyester resin is not used, the viscosity of the monomer
components is negligible when compared to the use of preformed resin
binders and cross-linking is not involved.
For the purposes of the present invention it has been found
possible to use proportions of unsaturated polyester resin dissolved in
monomers so long as the viscosity of the solution in the monomers does
not exceed about 50 cps. In terms of proportion by weight, the polyester
resin can constitute up to about 50% by weight of the binder components,
and is preferably 40% by weight or less.~ ~
As indicated previously the amount of binder component (a)
which can be used according to the present invention is generally
between S and 10% by weight of the composition, but even lower proportions
are suitably down to about 3 %. The low viscosity of the liquid organic
phase permits mixing in of high levels of aggregates, fillers and sand
and other inorganic components and the low surface tension of the liquid
phase allows intimate contact between the organic particles. Because
of the low proportions of liquid used, it is not so much the liquid phase
that provides the characteristics of curing and of the final product but
rather a product is provided which is a nearly inorganic, nearly mono-
lithic structure with particles of sand and aggregate intimately adhering
to each other. The final product has in fact more of the characteristics
of granite or stone than plastic, or for that matter even hydraulic concrete.
The amount of binder can be increased somewhat above 10% but
i increased too much then problems arise in obtaining a uniform concrete
and the improved properties obtainable with the lower binder levels
are sacrificed.
~The polymerization initiators which are added according to the
process of the present invention are free radical type initiators which will
1113~ 0
effect polymerlzation of the monomers, and where applicable, cross-linking
of the polyester resins used. These initiators may be either those which
are active at room temperature or at increased temperatures. An example
for use at room temperature is benzoyl peroxide together with nitrogen
containing promoters such as N,N-diethyl-m-toluidine and N,N-dimethyl-
aniline. An example of an initiator for use at elevated temperature is
bis-4-tertiary-butyl-cyclohexyl peroxydicarbonate. The use of heat
activated initiators and heat during setting of the concrete is of ad-
vantage in that it permits a longer pot-life of the fresh concrete mix.
Other examples of appropriate initiators will immediately occur to those
skilled in the art. The proportions of initiator will generally be 0.1
to 5% by weight of other binder components.
As indicated previously standard concrete mixing and placing
equipment may be used for the concrete according-to the invention. For
precast concrete components, the molds used are preferably closed molds
although open molds are possible. The reason for this is partly because
of volatility of the monomers when heat is used to effect setting and also
the use of closed molds prevents warping because heat can be applied from
both sides and a more uniform polymeri~ation obtained. If closed molds
are used, it is not necessary that the mold be completely closed and by
closed molds can be meant as well a mold with up to 10 - 30% of the
concrete surface area being exposed.
It is standard practice in the-manufacture of regular precast
concrete to vibrate the concrete in order to place it and bring to the
surface any air entrapped while mixing or pouring. The use of vibration
in the process of the present invention is essential for those reasons
and also for another, that is the achievement of minimum volume occupied
by the aggregates or placement of the aggregates without voids. By
reduclng the viscosity of the liquid phase preferably to something of
the order of less than 1 centipoise with concomitant reduction in surface
tension the aggregates can settle freely on vibration and orient themselves
in what lnevitably turns out to be the most compact placement. This of
10 .
11137~0
course cannot be achieved with viscous binders. Since this procedure
allows solids to impinge on solids, the shrinkage normally associated
with increasing monomer level and conversion to polymer is not experienced.
In the case of hydraulic concrete, over-vibration leads to segregation
of the mix which is undesirable. In the present process over-vibration
can be routinely used to ensure placing of the aggregates in the desired
configuration.
Various vibrating devices can be used depending on the manner
of manufacture of the concrete. For example with molds for precast
concrete table vibrators can be used whereas for cast-in-place applications
internal vibrating devices are appropriate. In fact any type of vibration
may be used and any frequency, even mechanical shock, as`long as it is
intense. The energy requirements are not dependent on frequency and
the amount of vibration that is to be used is determined empirically and
is such as is sufficient to remove significant amounts of voids. In
other words the spaces or gaps between aggregate particles are reduced
to a minimum.
Once the concrete mixture has been cast and vibrated, the
time required for setting will of course depend on the particular ini-
tiator used and whether or not heat is applied. The time required may
be anything from 5 minutes up to 3 hours or longer and the temperature may
be from room temperature up to 200 F or higher.
Reinforcing materials used in conventional concrete mixes
may also be used according to the present invention. These may be for
example reinforcing bars or steel mesh. Also steel fibres may be used in
the present compositions and can be merely mixed in with the other com-
ponents, which is unlike hydraulic concretes wherein the steel fibres on
mixing tend to agglomerate. Such reinforcment improves the tensile strength
and impact resistance of the concrete.
The polymer bonded concretes according to the present invention
can be modified as to surface appearance for various architectoral uses.
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,~ 111376~0
The surface of the concrete can be treated or etched with any solvent
for the polymer binder used so that an exposed aggregate effect is obtained.
A particularly useful solvent for polymethacrylate, polyacrylates or
polystyrene is methylene chloride. Surface treatment of this type is
normally produced in hydraulic concretes by etching with acids, retarding
the surface cure of the concrete and/or by sand blasting.
A plastic-like finish on the concrete may be obtained in
precast structures by applying a coating of pigmented resin in the mold
prior to casting of the concrete. This surface coating adheres per-
manently to the concrete product. Examples of such resins are Palatal*H-170 and Gel-Kote* (available from Glidden Company).
The following examples are intended to illustrate the present
invention but are not to be limiting to the scope thereof.
In all the examples the aggregates used were added to a con-
ventional pan-type mixer, the liquid ingredients except for initiator
then added, followed by the other dry ingredients and finally the initiator.
Mixing was continued for two minutes and the mix then transferred to a
closed 30 square foot mold. Vibration was carried out for two minutes using
a 1~ horse power reciprocal vibrator operating at a frequency of 3450 rpm.
.The conditions of curing or setting are detailed in each example.
Example 1
A polymer concrete according to the invention was prepared using the
following components:
Polyester Resin 72% Styrene 28% (Palatal*H-170) 3.5%
- ~ Methyl Methacrylate 3.1%
Bis-4-Tertbutylcyclohexyl Peroxydicarbonate 0.08%
Silica Flour ( ~200 Mesh) 12.6%
Ottawa Silica (27 Mesh) 21.2%
Round ~uartz Aggregates (1/8" - 3/8") 58.8%
Titanium Dioxide 0.8%
* Trade Mark
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% Organic: 6.7
Heat Cure: (~ hour at 175 F)
Thickness of Casting: ~ 3/4"
Compressive Strength: 13,500 p.s.i. (ASTM C39-73)
FLexural Strength: 2,750 p.s.i. (ASTM C78-75)
Modulus of Elasticity: 6.6 X 10 p.s.i.(ASTM C469-65)
Example 2
The following components were used in preparation of a polymer concrete
according to the invention:
Methyl Methacrylate 5.75%
Bis-4-Tertbutylcyclohexyl Peroxydicarbonate 0.05%
Titanium Dioxide ~ 0.25%
Calcium Carbonate 250 Mesh + 12.00%
Calcium Carbonate 50 - 500 mesh 14.00%
Aggregates 1/8" - l" 67.20%
% Organic: 5.8% .
Heat Cure: (1 hour at 160 F)
; Thickness of Casting: ~ 2"
Example 3
.
The following components were used:
Polyester resin 72%, Styrene 28% (Palatal*H-170) 3.20%
Butyl Acrylate 1.60%
Methyl Methacrylate 1.60%
Silica-Flour * (200 Mesh) 12.00
Ottawa Silica (27 Mesh) 32.00
Round Quartz Aggregates (1/8" - 3/4") 49.00
Titanium Dioxide 0.13%
N-N-Diethyl-m-Toluidine 0.04%
N,N-Dlmethylaniline 0.08%
Benzoyl Peroxide 70% (Granules) 0.25%
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% Organic: 6.77
Room Temperature Cure: (3 hours at 70 F)
Thickness of Casting: ~ 2"
* 7.8% retained on 200 mesh; 12.9% retained on 2io mesh;
11.1% retained on 325 mesh, pan: 66.7%.
Example 4
This concrete was prepared from the following:
Poiyester Resin 72%, Styrene 28%(Palatal*H-170) 2.5%
Methyl Methacrylate 2.5%
Bls-4-Tertbutylcyclohexyl Peroxydicarbonate 0.1%
Silica Flour ( ~ 200 Mesh) 12.9%
Ottawa Flour (27 Mesh) 21.9%
Round Quartz Aggregates (1/8" - 3/4") 59.7%
Titanium Dioxide 0.4%
% Organic: 5.1
Heat Cure: (3/4 hour at 175 F)
; Thickness of Casting: ~ 2"
This example was also repeated using only styrene in place
of methyl methacrylate withcomparable results.
,
Example 5
The following were used to prepare a concrete mix:
Polyester resin 72% Styrene 28%(Palatal*H-170) 3.3%
Methyl Methacrylate 2.7%
Bis-4-Tertbutylcyclohexyl Peroxydicarbonate 0.6%
Silica Flour ( ~200 Mesh) 10.0%
Ottawa Silica (27 Mesh) 15.0%
Round Quartz Aggregates (1/8" - 3/8") 68.5%
Iron Oxide Color 0.5%
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% Organic: 6.1
Heat Cure: 15 Minutes at 200 F
Thickness of Casting: ~7 1"
Example 6
The following ingredients were mixed and cured:
Polyester resin 72%, Styrene 28% (Palatal*U-170) 2.9%
Methyl Methacrylate 2.9%
Bis-4-Tertbutylcyclohexyl Peroxydicarbonate 0.06%
Silica Flour ( ~200 Mesh) 3.8%
Aluminum Hydrate (~verage lOO~Mesh) ~ 10.0%
Ottawa Silica (27 Mesh) 16.2%
Round Quartz Aggregates (1/8" - 1/2") 64.0%
Titanium Dioxide . 0.2%
% Organic: 5.9
Heat Cure: 1 Hour at 165 F
Thickness of Casting: 2"
.
Example 7
:A concrete was prepared from the following:
Polyester Resin 72% Styrene 28% (Palatal*H-170) 3.3%
Methyl Methacrylate 3.3%
Bis-4~Tertbutylcyclohexyl Peroxydicarbonate 0.1%
Silica Flour ( ~200 Mesh) 6.0%
Aluminum Hydrate (Average 100 Mesh) 13.4%
Ottawa Silica (27 Mesh) 15.2%
Round Quartz Aggregates (1/8'! - 1/2") 57.46%
Titanium Dioxide 0.14%
Molybdate Orange 1.12Z
rl~ ~ 1113700
% Organic: 6.7
Heat Cure: ~ Hour at 175 F
Thickness of Casting: < 2"
The polymer concretes of Examples 2 - 7 had properties very
similar to those of the concrete of Example l,for instance compressive
strengths of the order of 13,500 psi.
It was found that the properties of the concretes of the
foregoing Examples did not vary to any significant degree for the binder
proportions specified.
~ As an indicationof the fire resistant properties of polymer
concretes as illustrated in Examples 6 and 7, a concrete made from the
components as listed in Example 7 but without the molybdate orange coloring
was found not to give off smoke or flame during decomposition by a
2500F heat source. Smoke emission according to ASTM D2843 was 1% while
a test for fire resistance (ASTM D2863) resulted in an oxygen index of
over 80.
All of the foregoing examples of polymer bonded concretes
according to the invention may be used for precast panels for fascia panels
20 for buildings having thicknesses of 3/8 to 4", patio slabs. concrete flower
boxes, garden furniture, load bearing or non-load bearing sandwich panels
using urethane foam sandwich between two slabs of polymer concrete
adhered both mechanically and chemically, wall cladding 3/8 to 1 inch
thick to replace conventional lath and stucco systems, plywood and aluminum
and steel siding, and the like.
The polymer bonded concretes of examples 1, 3, 4 and 5 are
particularly suitable for the manufacture of drain, sewer and other pipes
because of chemical and abrasion resistance. These polymer concretes
are also of use for chemically resistant articles such as pump motor
30 boxes, storage tanks and basis, floor slabs and tiles.
-` 11137~0
The polymer concrete of Example 1 has been used in the form
of panels to protect the sides, undersides, or supporting pillars of
elevated highways because of its extremely high chemical resistance.
This concrete has also been used as permanent, white, impervious forms
for highway median strips, these forms being thin shells utilizing regular
hydraulic concrete as filler.
The polymer concrete of example 4 is abrasion resistant and
is particularly suitable for the manufacture of railroad ties and tracks
for rubber tired su~way cars.
la The polymer concretes of examples 6 and 7 are particularly
suitable for the manufacture of fire resistant panels and the like
because of the low binder content and inclusion of aluminum hydrate.
