Note: Descriptions are shown in the official language in which they were submitted.
--- 1086884
This invention relates to sulphur cements and concretes pro-
duced therefrom.
This application is a division of application Serial No.
251,362 filed April 28, 1976.
Sulphur cements have a long history of use in specialized appli-
cations. Thus, Canadian Patent No. 71,636 issued to George McKay pro-
vided a sulphur-containing composition useful for sealing purposes at a
joint, for roofing purposes, for the forming of ornamental figures, and
for the coating of the exposed surfaces of iron or steel steps, the com-
position including sulphur, brick-dust, tin, lead, bismuth, plaster of
paris and borax.
However, attempts to make durable, high strength concrete-like
materials from sulphur cements have encountered cost, durability, or
other difficulties that precluded commercialization. Proposals have been
made to increase the strength of sulphur as a bonding agent by the addi-
tion of coal, sand or pumice thereto. Moreover, peculiar characteristics
were proposed to be imparted by the addition thereto of bitumens,
metallic sulphides, and fibrous materials. Also, United States Patent
j No. 3,459,717 patented August 5, 1969 by J.B. Signouret, provided a
~0 sulphur-based plastic composition of improved fireproofing characteristics
by the incorporation, into the molten sulphur, of a diester of dithio-
phosphoric acid and an ethylenic hydrocarbon. A major problem in the
commercialization of sulphur cements has been the progressive embrittle-
ment and subsequent crumbling, under thermal stress, of the sulphur
cement. The cause of this embrittlement is believed to be the progressive
crystallization of the initially amorphous sulphur. Partial inhibition
of the crystallization has been achieved through various organic and
inorganic additives.
Thiokol (Trade Mark of Thiokol Chemical Corporation for olefin
polysulphide products) have been used to stabilize the amorphous form of
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sulphur in sulphur cements. Thtl8, Canadian Patent No. 356,181 lssued
February 25, l936 to W.W. Vuecker, purports to provide a solution to the
problem by dissolving, in the sulphur, certain olefin polysulphides or
polymerization products thereof. These cements, however, were not
practical on a large scale due to their high cost and disagreeable odor.
Dicyclopentadiene has good stabilization properties and more favourable
economics, but imparts a nauseating odor to the sulphur cement and has
other shortcomings, e.g., its vapour, even at low concentrations, is
highly toxic [see, for example, Kinkead et al, "The Mammalian Toxicity of
Dicyclopentadiene", Toxicology and Applied Pharmacology, 20 552-561
(1971)]. Moreover, dicyclopentadiene requires refluxing with molten
sulphur to avoid excessive loss of material in vapour form.
An object of one aspect of this invention now provided by the
present divisional application is to provide a sulphur cement composition
which does not suffer the disadvantages of the compositions of the prior
art.
An object of another aspect of this invention now provided by
the present divisional application is to provide a more durable sulphur
cement.
An object of yet another aspect of this invention now provided
by the present divisional application is to provide a sulphur cement
which can be made with off-grade sulphur.
An object of still another aspect of this invention now pro-
vided by the present divisional application is to provide a sulphur
cement which is resistant to the corrosive influence of salts, most acids
and solvents.
An object of a further aspect of this invention now provided by
the present divisional application is to provide a sulphur cement which
provides good thermal insulation and which develops high strength without
hours of cooling.
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.,
An ob~ect of yet a further aspect of this invention now pro-
vided by the present divisional application i9 to provide sulphur con-
cretes made with the sulphur cements, which are self-extlnguishing.
By one broad aspect of this invention now provided by the
present divisional application, a sulphur cement pre-mix composition i8
provided comprising: (a) sulphur and (b) a bonding agent which is
adapted to stabilize the sulphur cement against progressive embrittlement
and mechanical failure under thermal or physical stress, the bonding
agent being selected from the group consisting of: (i) up to 10% by
weight of the total amount of sulphur, of a liquid organic agent adapted
to stabilize the sulphur cement against progressive embrittlement and
subsequent crumbling under thermal stress, the agent comprising an
olefinic hydrocarbon polymer material, and having a non-volatile content
greater than 50% by weight and a minimum Wijs iodine number of 100 cg/g,
such polymer material being capable of reaÇtin~ with sulphur to form a
sulphur-containing polymer and being present ~n the su~p~hur cement as the
sulphur-containing polymer; and (ii) a mixture of up to 10% by weight
of the total amount of sulphur, of the liquid organic agent (i) and, for
each 100 parts by weight of sulphur, from 10 to 150 parts by weight of a
viscosity increasing, surface active, finely divided, particulate solid in-
organic agent, the inorganic agent being of a size passing through a screen
having a sieve opening of 0.147 mm, and being selected from the group con-
: sisting of fly ash, dolomite, pulverized limestone and a mixture of pyrites
and pyrrhotites.
By another aspect, the present invention now provided by the pre-
sent divisional application provides a sulphur cement composition consisting
essentially of: (a) sulphur which has been melted to ~ontain dispersed
therein (b) a bonding agent which is adapted to stabilize the sulphur cement
against progressive embrittlement and mechanical ~ailire under thermal or
physical stress, the bonding agent being se.lected from the group consisting
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(i) up to 10% by weight of tlle total amount of suLpimr, of a liquid or-
g~nic agent comprising an olefinic hydrocarbon polymer material having a
non-volatile content greater than 50~ by weight and a minimum Wi~5 iodine
number of 100 cg/g. such polymer material being capable of reacting with
sulphur to form a sulphur-containing polymer and being present in the sul-
phur cement as the sulphur-containing polymer; and (li) a mixture of up to
10% by weight of the total amount of sulphur, of the liquid organic~agent
(i) and, for each 100 parts by weight of sulphur, from 10 to 150 parts by
weight of and a viscosity increasing, surface active, finely divided, parti-
culate solid inorganic agent, the inorganic agent being of a size passingthrough a screen having a sieve opening of 0.147 mm, and being selected from
the group consisting of fly ash, dolomite, pulvçrized limestone and a mixture
of pyrites and pyrrhotites.
By one variant, the bonding agent may consist essentially of
(i), or it may consist essentially of the mixture defined as (ii).
By another variant, the bonding agent consists essentially of
the olefinic hydrocarbon polymer material, which polymer material is in
the form of a pre-reacted sulphur-containing polymer provided by reacting
the olefinic liquid hydrocarbon polymer with a smaller proportion of
sulphur than is required in the final sulphur cement.
By variations thereof, the ratio of the sulphur to the liquid
organic agent may be 2.45:1 or greater, or the amount of liquid organic
agent may be 1 to 5% by weight of the total sulphur.
By another variant, the bonding agent consists essentially of
the olefinic liquid hydrocarbon polymer material, the polymer material
being in the form of a pre-reacted sulphur-containing polymer provided
by reacting the heat reactive olefinic liquid hydrocarbon polymer with a
smaller proportion of sulphur than is required in the final sulphur
cement, and wherein the liquid organic agent is present in an amount of
1 to 5% by weight of the total amount of sulphur.
By a variation thereof, the bonding agent comprises a mixture
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of such organic material and fly ash of a size passing through a screen
having a sieve opening of 0.147 mm.
By still another variation, the bonding agent comprises a mix-
ture of the olefinic liquid hydrocarbon polymer material which i9 in the
form of a pre-reacted sulphur-containing polymer provided by reacting the
heat reactive olefinic liquid hydrocarbon polymer with a smaller propor-
tiOII of sulphur than is required in the final sulphur cement and fly ash
of a size passing through a screen having a sieve opening of 0.147 mm.
By yet a further variant, the composition includes an additive
to provide fire resistance, e.g., 1,5,9-cyclododecatriene, or the reac-
tion product of diphenoxyphosphinic acid with sulphur and with ~-methyl
styrene.
By another aspect of this invention now provided by the present
divisional application, a sulphur concrete is provided comprising (A) a
sulphur cement pre-mix composition consisting essentially of (a) sulphur
and (b) a bonding agent which is adapted to stabilize the sulphur cement
against progressive embrittlement and mechanical failure under thermal or
physical stress, the bonding agent being selected from the group consis-
ting of (i) up to 10% by weight of the total amount of sulphur, of a
liquid organic agent, the agent comprising an olefinic hydrocarbon poly-
mer material having a non-volatile content greater than 50~ by weight and
a minimum Wijs iodine number of 100-cg/g, such polymer material being
; capable of reacting with sulphur to form a sulphur-containing polymer and
being present in the sulphur cement as the sulphur-containing polymer; and
(ii) a mixture of up to 10% by weight of the total amount of sulphur, of
the liquid organic agent (i) and, for each 100 parts by weight of sulphur,
from 10 to 150 parts by weight of and ~ viscosity increasing, surface active,
- finely divided, particulate solid inorganic agent, the inorganic agent
being of a size passing through a screen having a sieve opening of 0.147
mm, and being selected from the group consisting of fly ash, dolomite,
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1086884
- pulverized limestone ant a mixture of pyrites and pyrrhotites; and (B)
natural or manufactured aggregates.
By another aspect of this invention now provided by the present
divisional application, a sulphur concrete is provi.ded comprising (A) a
sulphur cement composition consisting essentially of: (a) sulphur which
has been melted to contain dispersed therein (b) a bonding agent which
is adapte~ to stabilize the sulphur cement against progressive embrittle-
ment and mechanical failure under thermal or physical stress, the bonding
agent being selected from the group consisting of ti) up to 10% by weight
of the total amount.of sulphur, of a liquid organic agent, the agent
comprising an olefinic hydrocarbon polymer material and having a non-
volatile content greater than 50% by weight and a minimum Wijs iodine
number of 100 cg/g, such polymer material being capable of reacting with
sulpjur to form a sulphur-containing polymer and being present in the
sulphur cement as the sulphur-containing polymer; and (ii) a mixture of
up to 10% by weight of the tot~l amount of sulphur, of the liquid organ-
ic agent (i) and, for each 100 parts by weight of sulphur, from 10 to
150 parts by weight of and a viscosity increasing, surface active, finely
. _ , . _ . . . .
divided, particulate solid inorganic agent, the inorganic agent being
of a size passing through a screen having a sieve opening of 0.147 mm,
and being selected from the group consisting of fly ash, dolomite, pul-
verized limestone and a mixture of pyrites and pyrrhotites; and (B)
natural or manufactured aggregates. -
By a variant thereof, the ratio of aggregate (B) to sulphur
cement (A) is 80-36:20-64.
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The sulphur cement or sulphur-cement pre-mix forming an essen-
tial element of the sulphur concrete of this aspect of this invention now
provided by the present divisional appllcation may be any one of the
variants and variations heretofore described.
The present invention now provided by the pre~ent divisional
application in one of its aspects provides a sulphur cement which can be
used for the manufacture of sulphur concrete having numerous applications
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in the construction field. It is substantlally free from the disadvan-
tages of the products described previously and has positive advantages,
as will be described hereinafter.
The sulphur cement according to one aspect of this invention
now provided by the present divisional application employs, as the stabil-
izer, the particularly recited olefinic liquid hydrocarbon stabilizer,
e.g., the heat reactive polymer derived from petroleum, as hereinabove
more particularly described. The proportions of the chemical stabilizer
may be varied depending upon the end use of the cement.
The chemical stabilizer used in the compositions of aspects of
this invention now provided by the present divisional application is any
of the olefinic hydrocarbon polymers derived from petroleum having a non-
volatile content greater than 50% by weight and a minimum Wijs iodine
number of 100 cg/g capable of reacting with sulphur to form a sulphur-
containing polymer. Typically, the chemical stabilizer is used in amounts
up to 10% by weight of the total sulphur, and more especially in the pro-
portion of l - 5% of the total sulphur by weight. The amount of such
chemical stabilizer required depends upon the end use of the cement and
the properties desired.
The chemical stabilizer can be incorporated into the final
cement mix by several reaction routes within the ambit of this invention.
Preferably, the chemical is pre-reacted at approximately 140C. for 30
minutes with a smaller proportion of sulphur than is required in the
final mix. The resulting concentrate can then be either stored for
future use or dissolved in the residual sulphur (liquefied) required for
the final mix at the mixing temperature.
While any chemical stabilizer having the above properties may
be used, typical such chemical stabilizers are those known by the
following Trade Marks: RP220, a product of Exxon Chemical Co.; RP020, a
product of Exxon Chemical Co.; CTLA, a product of Enjay Chemical Co.;
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and ESCOPOL, a product o Esso Chemical AB (Sweden); all identifying a
heat reactive olefinic liquid hydrocarbon obtained by partial polymeriza-
tion of olefins.
In order to provide a sulphur-containing cement of aspects of
this invention now provided by the present divisional application having
a workable consistency, it is necessary to add to the liquid organic
stabilizer, a finely divided, viscosity increasing material, for example,
fly ash, gypsum, dolomite, pulverized limestone, a mixture of pyrites and
pyrrhotites, or rock dust of a size up to minus 100 mesh, but preferably
of a size of minus 200 mesh. Fly ash from the burning of hydrocarbon
fossil fuels and generally in the form of tiny hollow spheres called
cenospheres and consisting of major amounts of silicon oxide and aluminum
oxide, with smaller quantities of ferric oxide, calcium oxide, magnesium
oxide, sodium oxide, po$assium oxide and carbon, is particularly effec-
tive in this regard due to its small particle size, shape and surface
texture. It has been found to impart an extra measure of durability to
the final cement, independent of its source, and serves the dual func-
tion of viscosity increaser and sulphur cement stabilizer. Depending
upon the degree of fineness of the fly ash and the consistency desired,
an amount up to one and one-half times the total weight of the sulphur
may be beneficially added.
A notable feature of the sulphur cement of aspects of this
invention now provided by the present divisional application is that such
sulphur cement does not require high purity sulphur and can be made with
off-grade sulphur containing hydrocarbon impurities, blow dirt, and other
"contaminants". The presence of hydrogen sulphide (H2S) in the sulphur
has been determined to be detrimental, but the simple process of remelting
the sulphur usually reduces the concentration of this contaminant to
harmless levels.
The resulting cement of an aspect of this invention now provided
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by the present divisional application is substantially resistant to the
corrosive influences of salts, most acids, and solvents. Hot oxidizing
acids at high concentrations and strong concentrated bases do attack the
cement, however. The cement is essentially impervious to moisture
penetration. It provides good thermal insulation, is used hot with no
water, and develops high strength within hours of cooling. Thus, sulphur
concrete pouring can take place in winter without the usual freezing
problems of conventional portland cement concretes, which require the
presence of water for setting.
A wide range of aggregates can be used with the sulphur cement
of one aspect of this invention now provided by the present divisional
application as described above, to make strong, durable concretes of
another aspect of this invention now provided by the present ~ivisional
application. Among the conventional aggregates useful herein for pre-
paring the concrete of another aspect of this invention now provided by
the present divisional application are sand, crushed cinder~, brick dust,
foundry sand, crushed quart~ite gravel, crushed limestone, siliceous
tailing sand, expanded shale, expanded clay, crushed barite, crushed
brick, crushed portland cement concrete, and crushed granite. Preferably,
the aggregate particles are of angular shape and of rough surface texture
as can be obtained by crushing. With a sufficiently fluid mix, or
through use of heated molds, the mold surfaces are reproduced precisely.
Where sulphur is readily available, the cement and the concrete of
aspects of this invention now provided by the present divisional applica-
tion can be produced at competitive costs. The compatibility of the
sulphur cement of aspects of this invention now provided by the present
divisional application with aggregates of wide ranging densities permits
the design of concretes having very wide ranges of densities ranging, for
example, as low as 10 lbs. per cubic foot, to ranges between 100 lbs. per
cubic foot and 230 lbs. per cubic foot, or even as high as 500 lbs. per
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cubic foo~. The sulphur concrete of an aspect of this lnvention now pro-
vided by the present divisional application can be reinforced in conven-
tional fashion by the use of steel, asbestos or glass fibre, or other
reinforcing materials.
The sulphur concretes of aspects of this inven~ion now provided
by the present divisional application tend to be self-extinguishing with
ash contents approaching two-thirds the weight of sulphur and can be made
fire resistant, and/or to inhibit the formation of S02 when heated, by
the addition of suitable additives, e.g., 1,5,9-cyclododecatriene or the
reaction product of diphenoxyphosphinic acid with sulphur and t~-methyl
styrene.
The sulphur concretes of another aspect of this invention now
provided by the present divisional application derived from the sulphur
cements of a first aspect of this int~ention now provided by the present
divisional application are not refractory materials and will soften and
melt if heated above 120C., although the rate of melting is slow due to
the low thermal conductivity imparted to the concrete by the sulphur.
`~ The principles developed for the grading of aggregates used in
conventional concretes are essentially unchanged for sulphur concretes
~0 of aspects of this invention now provided by the present divisional
application except for the much greater tolerance of fines and silt of
the sulphur concretes. 80% of the ultimate concrete strength is developed
in one day; virtually 100% of the ultimate strength is realized after
four days.
These sulphur concretes may be used as a construction material
for a wide variety of precast and poured-in-place applications, e.g.,
sidewalks, steps 9 parking curbs, highwary median barriers, sewer pipe,
septic tanks, pilings, footings, foundations, pavements, industrial tanks,
ponds, swimming pools, etc. The hot sulphur concrete mix may also be
pumped and sprayed for waterproof and erosion proof coatings on earth-fill
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1~6884
dikes, highway and railway embankments and as linings for irrigation
canals, farm ponds, etc.
The examples given below are lntended only to lllustrate aspects
of the present invention now provided by the present divisional applica-
tion.
The hydrocarbon stabilizer (at 25C.) was added to molten
sulphur (at 140C.) with vigorous stirring. Heat was applied only to
maintain a reaction temperature of 140 to 150C. At this temperature
reaction times were in the order of 15 to 40 minutes. The progress of
the reaction could be monitored by the degree of homogeneity of the mix,
by careful observation of the temperature of the reaction mixture, or
by observation of the increasing viscosity of the mixture. At sulphur-
stabilizer ratios of less than 4:1 by weight, control of the addition
rate was required to prevent the exothermicity of the reactions raising
temperatures above 155C., at which point hydrogen sulphide (H2S~ was
evolved with consequent foaming and degradation of the product.
When reactions were conducted under the above-prescribed con-
ditions, the product was a sulphur-containing polymer which, on cooling,
possessed glass-like properties which were retained indefinitely.
The properties of the olefinic hydrocarbon polymers used for
illustrative purposes herein are given in Table 1. Reaction conditions
for the preparation of seven sulphur-containing polymers are contained
in Table 2.
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- Table 1
RP220 RP020CTLA Escopol
Flash Point (COC) minimum 150 13R 150 125
Gravity (API) maximum 4 4.0 9.6 3
Iodine Number (lOOcg~g) minimum 200 160 255 135
Non-volatile Matter (X b~ weight) 80 70 83 75
(3 hrs. @ 105C) minimum
Density (15.6C.) gm/cc 1.05 1.04 1.00 1.03
Viscosity (cst/100C) maximum 25 26 28 25*
*cst/50C.
Table 2
Reaction Conditions for the
Preparation_of Sulphur-containing Polymers
Stabillzer Weight (K~) Reaction Reaction Product
Sample (STB)STB S ''Temp.(C)' Time (Min) Colour
1 CTLA 12.5 37.5 140 30 dark brown
2 CTLA 8.3 41.7 140 40 dark brown
3 Escopol 10.0 40.0 150 15 light brown
4 Escopol 14.5 35.5 140 20 light brown
RP220 8.3 41.7 150 15 dark brown
6 RP220 12.5 37.5 140 20 dark brown
7 RP020 12.5 37.5 140 15 dark brown
Examples'l to 9 - Sulphur Cements and Concretes Derived Therefrom
A first series of sulphur cements, Examples 1 through 9, were
prepared by addition of: the required sulphur (less than contained in
the prereacted material), the prereacted material, and lastly, fly ash
to achieve the desired consistency of the sulphur cement'. Then the
aggregate was added to provide the sulphur concrete.
The components were mixed at 130C. in a heated 1/3 cubic foot
concrete mixer for 15 minutes before pouring into molds. Compaction was
obtained through vibration or tapping of the molds. For simplicity of
representation, all the examples are chosen using RP220 as the hydrocar-
~` bon stabilizer.
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1~86884
Examples 10 to 13
A second series of sulphur cements and sulphur concretes was
prepared in a manner analogous to that of Examples 1 to 9 with the
exception that raw stabilizer (i.e. not pre-reacted with sulphur) was
added directly to the mix at the previous point of pre-reacted material
addition. In order to allow completç reaction, the mixing time was
increased to 20 minutes.
The results are summarized and tabulated below in Table 3.
Table 3
Sulphur Concretes - Composition and Properties
Chemical
Stabi- Compres-
Exam- Aggre-lizer Density sive*
ple gateSulphur Fly Ash RP220 (g/cc) Strength
1 Crushed quartzite 71.720.4 7.4 0.50 2.38 7,160
gravel
2 Crushed limestone 73.526 - 0.50 2.41 5,290
3 Siliceous tailings 63.534.8 - 1.7 2.21 5,290
sand
4 Expanded shale 38.6 37.623.2 0.59 1.73 4,610
Expanded clay 38.4 32.029.2 0.38 1.77 8,350
6 Crushed barite 78.7 15.05.9 0.38 3.18 7,520
-20
7 Crushed brick 54.5 27.317.5 0.68 2.17 8,530
8 Crushed portland 64.124.1 11.2 0.60 2.23 5,690
cement concrete
9 Crushed granite 65.920.0 12.6 0.50 2.39 7,760
Crushed quartzite 64.419.6 15.5 0.49 2.38 8,710
gravel
11 Siliceous tailings 60.930.8 7.5 0.77 2.23 6,530
sand
12 Expanded shale 50.0 26.622.7 0.66 1.70 4,740
13 Crushed barite 79.1 13.27.4 0.33 3.28 7,650
* Mean of three (3) tests.
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