Note: Descriptions are shown in the official language in which they were submitted.
CA 02216173 1997-09-23
WO 96I3~0446 PCT/LTS96/04001
AS PHALT EM(JLS I ONS
The present invention relates to aqueous
emulsions of asphalt or coal tar, and in particular to
aqueous asphalt emulsions of the oil-in-water type
wherein the asphalt component is the discontinuous phase
and the aqueous vehicle is the continuous phase. More
particularly, the present invention relates to aqueous
emulsions of asphalt that can be combined with fillers
such as clay, sand and/or fibers (such as fiberglass
and/or cotton), and in some cases modified with
polymerized materials such as rubber, latex or SBR-type
polymers. Such filled emulsions are typically used for
applying sealing coatings to driveways, parking lots,
pipes, and the like.
Asphalt is conventionally recognized in this
field as a dark brown to black cementitious material in
which the predominating constituents are bitumens that
occur in nature or are obtained in the fractionation of
petroleum. Asphalt characteristically contains very
high molecular weight hydrocarbons soluble in some
hydrophobic solvents. Bitumen is generically known as a
class of black or dark-cementitious substances, natural
or manufactured, composed principally of high molecular
weight hydrocarbons.
Asphalts have been known for many years in
various naturally-occurring types, but more and more
conventionally asphalts are obtained as a very high
molecular weight fraction obtained through the refining
or fractionation of. petroleum feed streams. In some
3p cases these petroleum fractions are chemically processed
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-2-
prior to or after fractionation; and emulsions made with
the resulting treated asphalts are also the subject of
this application.
Asphalt is useful in its ability, especially
when combined with a fine particulate filler, to form a
continuous, highly water-impervious film or coating when
applied for instance to roofs, and other exterior
surfaces such as driveways, sidewalks, roadways, pipes,
and the like.
Coal tars and fractionated coal tars are
currently used in such applications, as emulsions and
particularly as filled emulsions. The present invention
can be considered applicable to the formation of such
filled emulsions of coal tar and coal tar derivatives as
well as to filled emulsions of asphalt.
Historically, coal tar and derivatives thereof
have been incorporated into filled emulsions as the
primary asphalt-like material. Filled coal tar
emulsions are easily made using any of various
surfactants. However, coal tar and its derivatives have
become suspected as possibly carcinogenic, so avoiding
their use has become desirable. Identifying
satisfactory asphalt emulsions which are free of coal
tar and coal tar derivatives is thus one of the
principal objectives of the present invention.
The task of emulsifying asphalt and keeping it
emulsified as a uniform dispersion of asphalt in the
water in the presence of filler material, affording easy
formulation of the final filled emulsion product, and at
the same time obtaining the emulsion in a form which
CA 02216173 1997-09-23
WO 961:0446 PCTJUS96104001
-3-
resists premature breaking, has been notoriously
challenging. The components of the emulsifying system
have to permit formation of the emulsion as desired
prior to application of the emulsion to the particular
surface. Once the emulsion has been applied and the
water has evaporated, the components of the emulsifier
system remain behind yet must not be permitted to re-
emulsify the asphalt upon subsequent exposure to water.
In addition, it is conventional practice to manufacture
emulsion for the consumer in large batches, comprising
hundreds or even thousands of gallons, from which
individual consumer-sized quantities of the emulsion are
dispensed for resale. Unfortunately, cationic and many
anionic emulsifiers do not permit formation of stable
filled asphalt emulsions which satisfy all of these
requirements_
The stability of the emulsion before use, and
the rapid curing of the emulsion after application, are
particularly critical for packaged products sold to
consumers but are also important for bulk products sold
to contractors and large-scale applicators. The ability
to formulate the emulsions, particularly on such large
scale, is vulnerable to variations in the constitution
of the water used to formulate the emulsion, and
particularly vulnerable to the presence of dissolved
salts which when present are known as "hardness" of the
water. These salts can interfere with the ability to
establish the desired emulsion, either through co-acting
with the components of the emulsifying system, or
3G
CA 02216173 1997-09-23
WO 96/30446 fCT/US96/04001
-4-
1 otherwise for instance by undesirably altering the ionic
strength of the aqueous phase of the emulsion..
The stability and curing behavior of the
asphalt emulsion are particularly~sensitive to the
presence of solids added to the emulsion to form a
filled emulsion product. These properties are also
sensitive to the amount of such solids and to their
identity.
It is also advantageous in some cases to
produce a filled emulsion that is thixotropic. This
thixotropic, or shear thinning, property minimizes
splashing and pooling of the emulsion in low spots while
enabling application of a desired thickness.
Accordingly, the present invention is directed
to emulsifiers~for the formation of asphalt emulsions,
which are not adversely affected by the presence of
solids used to produce filled products.
The present invention is also directed to
emulsifying agents for use in formulating asphalt
emulsions, which resist premature "breaking" of the
emulsion while in storage prior to application. It is
furthermore desirable to formulate asphalt emulsions
with components that are easily available and relatively
inexpensive, and which as well do not adversely affect
the quality of the film or coating formed following
application of the asphalt emulsion.
The present invention is more particularly is
directed to a storage-stable oil-in-water asphalt
emulsion, comprising
(A) water as the continuous phase;
CA 02216173 1997-09-23
WO 96130446 PCT/US96/04001
-5-
(B) one or more emulsifiers selected from the
1
group consisting of (i) compounds of the formula (Ia),
(Ib)
(R1CH(OH)-(CHZ)n,S03)iX - (Ia)
(RICH=CH (CHZ) n,_1S03) iX (Ib)
and mixtures thereof, wherein R contains 6 to 40 carbon
atoms and is straight or branched aliphatic, aromatic,
alkyl-aromatic, aromatic-alkyl, or alkyl-aromatic-alkyl,
m is 1-10, X is -H or is a canon such as sodium,
calcium, potassium, lithium or ammonium, or an amine of
the formula -N+H (C1_2o alkyl) 2 or -N'HZ (C1_2o alkyl) , and i
is 1 or more and is the valence of x;
(ii) compounds of the formula (II)
R20- (AlkO) ~CH2COOX ( I I )
and salts thereof with a cation X as defined above,
wherein R2 contains & to .40 carbon atoms and is straight
or branched aliphatic, aromatic, alkyl-aromatic,
aromatic-alkyl, or alkyl-aromatic-alkyl, each Alk is
s tra fight or branched CzH4 , C3H6 or C4H8 , and c i s 1- 2 0 0 ;
(iii) compounds of the formula (III)
( (R3) k- (A) -S03) iX (III)
35
CA 02216173 1997-09-23
WO 96/30446 PCT/LTS96/04001
-6-
wherein R3 contains 6 to 40 carbon atoms and is straight
or branched aliphatic, aromatic-alkyl, or alkyl-
aromatic-alkyl, A is aromatic, X and i are as defined
above, and k is 1, 2 or 3; and
(iv) amphoteric emulsifiers of the formulas
(a) , (b)
R4- (OC3H6) 0_1- (C (O) NH (CHZ) 1_3) o_1-N (Z1) (Zz) o_1-ZCOOX (a)
R4 (OC3H6) °_1 (C (O) NH (CHz) 1_3) o_1-N (Z1) (Z2) p_1-ZS03X (b)
wherein X is -H or a cation such as sodium, calcium,
potassium, lithium or ammonium, or an amine of the
formula -N'H ( C1_zo alkyl ) 2 or -N*H2 ( Cl_2o alkyl ) , R' is
straight or branched alkyl or alkylene, or cyclic or
heterocyclic aromatic which is optionally substituted
with alkyl, and contains 4 to 40 carbon atoms and 0-5
carbon-carbon. double bonds,_Z1 and Z2 are independently
of each other H, CfH2f+1 or CfH2fOH wherein f is 1 to 6 and
Preferably 1, 2 or 3 or, in formula (a) , one of Z1 and ZZ
can be -ZCOOX, and Z is (CHZ) f, CH2CH20CH2CH2, or
CHZCHOHCH2 ;
(C) asphalt, comprising a discontinuous phase
uniformly dispersed in said emulsion; and
(D) finely divided particulate filler
uniformly distributed throughout said emulsion.
From evaluations of many anionic and
amphoteric emulsifiers, and finding little success, it
is quite surprising to have found that emulsions in
accordance with this invention form storage-stable
CA 02216173 1997-09-23
WO 9610446 PCTlIJS96104001
_7_
filled emulsions, without loss of the emulsion and
without loss of stability or curing properties.
Further, the present invention is directed to
3
a method of making an oil-in-water asphalt emulsion,
comprising combining asphalt, an aqueous continuous
phase, and one or more emulsifiers selected from the
group consisting of compounds of the formulas (Ia),
(Ib), (IT), (III), (a) and (b) as defined above, and
finely divided particulate filler, in any sequence under
emulsifying conditions effective to form an emulsion
which exhibits long-term phase stability.
It has now, quite unexpectedly, been found
that emulsifying the asphalt with any of the
aforementioned emulsifiers of formulas (Ia), (Ib), (II),
(III), (a) and/or (b) affords uniform dispersibility of
th.e asphalt in water and obtains an emulsion which
resists premature breaking. The system forms an
emulsion which prior to application is stable, at room
temperature conditions, for a reasonably long period of
time. The emulsion is able to withstand mixing with
fine particulate matter such as clay, fibers, or sand
without breaking (becoming two distinct phases of oil
and water). The resulting emulsion mix, sometimes
called a ~~ filled emulsion~~ , is compatible and stable
for
a reasonably long period of time. That is, it remains
liquid; retains its essentially monophasic state; and
retains particulate filler without breaking.
By correct choice of the emulsifier, the flow
properties of the resulting emulsion can be varied
anywhere from a relatively thin free flowing liquid to
a
CA 02216173 2003-10-30
_g_
thixUtr~pic 7. i.c~ui d . Once t3ze f filled cululsion i.s
1
apla7~ a.ed, or exampl.e oii t~31~: ~ut'ta~ee cy-F dra.v~vaala,
paxv:img 3ot~, pipii'7g, cyr in crack fillirs~ upp~.icatio~~,
fir. cures in a reaeona~ly short. Lime uri t:h associated
vra~Cx' ~v~porat i can . 'I:hi p C17.BCOVex'~~ turt~leiasc~~G,
perln).CR
cn~P f:n formulate tlae asylalL OCUL111;1bri SVJ.t27 GUm~znnentr~
that are eatj.i:ly :~.xi~.~r~l~ ana L~1 ar.:i.vQ7.y iuexpes~aivt
.
'fhe c~ephc~l2: (car. bitumat~l ernploy~d i.t?, this ,
invPnti.an can be either a n~tuiaLly-CsCCIIIZ'7.i7g ~~phalt
or
r cn~~crlufia~:tured a~~7l~aa.r. produced ar iszatamee ?~~
~eiit77~ tig
1.C
petro:leutrc. IL yam >'7u t1 ~Oal t.ar or. coal. rar derivaZivc
_
Tt fan be other heavy bituminous mai:aiittl ~.~ wel7 at,
Hc::xvy orgc~rii c= raFirluuma_ naturally-flccurrin~ a:~~Htal
~:.r
euiL~tbl~ fo1 u3e in t'.hi~ :i~1ve11t.i.on include, BUY'
c:xamh3e,
7.ake asphalta, rack aephalt~t mnC~ C11~ like. Sma.t-_ahla
m~nufaotured aaphalt~ inclmdP, for exaasplt, ~~raigl~~.-run
a~phal ta, Zsi'oYa~t3~; Fis~ph~~lta, ,~ i r-171 ro,vn aephalte
, L~tC:r's1y~11
aey~halta, blended ~taphall~, amd t.h~: 7 1 ke _ ns used
herein, the term "aapi~,a3.t" irtcl.udc::~ itl~t.eT~1 a7.r:
t~ometimee
.rPf.erred to as "bitumen" . ~s, turthel~ dcs3ci':ipt,iOri
Of
~;~p11~t1C u::eiul 11~ thi;~ invelWion may he fc~ut-sd in
the
"Hncyclopedia of Chemical Tecrmolv~
~y"
VvlLUrie 3 ~ at ~7p.
,
~
284 -327.
.. Iispl~al~~ preferred for ueu in 1:~11~ 111v~17t.1017
lave at5 i.t~it.i~7 vi:~cr.'r.~i.Gy ~i .~. fills viscosity Briar to
ernulsi.ticatxoiiy at 60°C vL fZCnu uk~c~ul 100 tm ~hc~ut
20, ODO poiS~, alCliOUgh a~phalr.~ having higher yr lower
viacaaitiea can also be uae~ul , The vi:~~':~7i~tt.y rn~y hr-,-.
r~eterrnioed by ChP pTt~c~pdm-ea r3QRC:rihPd in ASTt~Wt:~l
CA 02216173 1997-09-23
WO 9C/~0446 PCTlUS96/0.~001
_g_
Method D2171. The asphalt quality can also be described
by hardness or penetration number. Typically, asphalts
in the penetration range of 5 to 400 and preferably 20
to 150 are used, but asphalts with higher or lower
values can be used. For some applications, such as
' driveway sealers, the preference is for harder asphalts
(lower penetration number) so that the asphalt can
resist softening by drippings of petroleum based
products.
The emulsifiers of the present invention can
include (i) one or more compounds corresponding to
either or both of the following formulas (Ia) and (Ib):
( R1CH ( OH ) - ( CHZ ) mS03 ) iX ( I a )
( R1CH=CH ( CHz ) rt,_1S03 ) iX ( Ib )
wherein in each of formulas (Ia) and (Ib), R1 contains 6
to 40 carbon atoms. Preferred R1 groups include straight
and branched alkyl groups containing 9-25, and
preferably 15-17, carbon atoms. Preferred R1 groups
containing an aromatic moiety include these wherein the
aromatic moiety is phenyl. Other aromatic moieties
include naphthalene, indanyl and indenyl. Examples of
groups with an aromatic moiety include phenyl, alkyl-
substituted phenyl, benzyl and alkyl-substituted benzyl.
In formulas (Ia) and (Ib), m is 1-10 and preferably 2-4.
Preferred compounds include those known
generically as olefin sulfonates, which are mixtures of
long chain sulfonate salts prepared by sulfonation of
CA 02216173 2001-07-27
'~Lf-'-'~-.'-1'J'~.' L 1: 1~~ I-I~:UM ' ~~::LLI_'r' ' nUl f ~U I '_~LL.1
:~34'_r_~S f'. 1'-'~
w o ~s~3aaa6
rc~rnrsa~aoo i
1 long c:hanr olaiinr~.- I3ecaurse of thc~ raatrme of the
sulCon.:rtion pro~:e:~s, the olefin suZfonatp,~; generally
compri:ee mixr,~t,_-~,.; ~,i ~,ikene sul fonatcs ~ and kiydroxy
alkane sulfonates. Pax~tici~larly greierred olefin
=:ulioixates i.noludn, but. are not Zimitr?c3 to, alpha:-olef in
nu'Lfonat~es.
L~rcfexrer3 oxarr~pl,es of these olefin sulfonates
usel:uZ irx the present inventic>n axe thr~sc~ ,sold by W1_tco
Corgoratic~n una~r 'the rramfi ~Wit conat:~~'~OS", and
zo "wxtc~,nat~ r;QS-z~c" .
Tlre emulsi.f ier:~ u:~e~ul in Lhe prey;cnt
iravent:ion also 'inr_lurle one car more carhoxylated
nonzon_ics of the foi~mua.s~ (II)
1 ~ k20- (AlkO) ~.CHICf,~H ( TI )
and/or st-r7 is thereof with a ration X ns defined abovrs,
Tn formpi_a (iI) ~ nl containn G to ~1p carlavn atoms and. can
ara <xlkyl r.~roup which r_~zr1 be stra:i.gYtt ox branched.
20 Hxampl es of such ally]. groups include tc:~rader_yl,
tr (decy7, , anc~ ethylhexyl . P.re~exred R~ groups iucl,ude
any of those described above ,with xe~r~poct. s=o prefexred R1
groups. A pre~~rxrr~l example at R; as a subrti'tut~~.d
hhany~. group is rrony_l. phenol.. each (hlk0) group crrn be
etho,ty, propox~,~ c7r buCoxy, 't~r,~ pr~Lei'reci (Alko) ~ cars be
a chain of randomly ar:~n~Ied ethoxy and pxopoxy units,
a Ixomo--oligomer of only .ethoxy or only prcpoaty uni.t:s, a
bloc)e cohoZymc:r containirxd one or more-~ blflcks . of
repe.xtzng ethoxy units and one or tr,ore bl.ockr: of
r-epeat.zng l3xopQxy urrit~s, or- ether conrloinaLion: of et~kroxy
35 * trademark
CA 02216173 1997-09-23
WO 96I~0446 PCT/US96104001
-11-
and propoxy. As noted, the total number c of alkoxy
units is 1-200, preferably 1-60 and more preferably 5-
20.
. The emulsion can also comprise one or more
alkyl aryl sulfonates of the formula (III):
v
( ( R3 ) k-A- S03 ) iX ( I I I )
wherein i and X are as defined hereinabove. Each R3
group contains 6 to 40 carbon atoms. Preferred R' groups
include straight or branched alkyl groups containing to
6 to 40, preferably 6 to 24, and more preferably 12 to
19:, carbon atoms. Other preferred R3 groups include
aromatic-alkyl, such as benzyl or phenethyl, it being
nated that R3 should be selected so that an aromatic
moiety is not bonded directly to A. Preferably A is a
monocyclic or polycyclic aromatic group, preferably
phenyl or naphthyl and more preferably phenyl, and k is
1, 2 or 3. Preferably, k is 1.
It should be recognized that, if desired,
amounts of other emulsifying components (such as
amphoteric and nonionic emulsifiers) may be present
together with the one or more compounds of the foregoing
formulas (Ia), (Ib), (II), and/or (III). Thus, while
the advantages attributed to the present invention can
be realized by employing solely one or a mixture of the
compounds of the foregoing formulas (Ia), (Ib), (II),
and/or (III), as the emulsifying components, the scope
of the present invention is not confined to those
systems which exclude the presence of other emulsifying
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-12-
1 agents so long as they are compatible with the
emulsifying capabilities of the compounds described
herein. Indeed, the compatibility and synergy of these
compounds when used together with other emulsifying
agents, while still being able to maintain a storage-
stable emulsion, is another valuable and unexpected
aspect of this invention.
For instance, the emulsion can include one or
more amphoteric emulsifiers, particularly those of the
formula (IVa),(IVb)
R4- (OC3H6) 0_1- (C (0) NH (CHZ) 1_3) o_1-N (Z1) (ZZ) o_1-ZCOOX (IVa)
R4-(OC3H6)o_,-(C(O)NH(CH2)1_a)o-i-N(Z1) (Za)o_1-ZS03X (IVb)
wherein X is as defined above, R' is straight or branched
alkyl or alkylene, or cyclic or heterocyclic aromatic
which is optionally substituted with alkyl, and contains
4 to 40 carbon atoms and 0-5 carbon-carbon double bonds,
Z1 and ZZ are independently of each other H, CfH2f,1 or
CfH2FOH wherein f is 1 to 6 and preferably 1, 2 or 3 or,
in formula (IVa) , one of Z1 and ZZ can be -ZCOOX, and Z
is ( CHZ ) f , CHZCHZOCHzCH2 , or CHaCHOHCH2 Formulas ( IVa ) and
(IVb) embrace betaines, sulfobetaines (sultaines),
glycinates and propionates, which are commercially
available and/or can readily be synthesized.
Examples of amphoteric emulsifiers include
fatty betaines such as lauryl dimethyl betaine (e. g.
REWOTERIC~ AM-DML-35)(this and all other REWOTERIC'~
branded compounds are marketed by Witco Corp.) and N
CA 02216173 1997-09-23
WO 96f30446 PCTlUS96104001
-13-
lauryl-beta-iminopropionic acid, mono-sodium salt (e. g.
REWOTERIC AM-LP); glycinates such as N-
cocoylamidoethyl-N-(2-hydroxyethyl)-N-carboxymethyl
glycine, disodium salt (e.g. REWOTERIC AM-2C-W) and the
N-lauroyl analog thereof (e. g. REWOTERIC-AM-B-15);
propionates such as sodium cocoamphopropionate (e. g.
REWOTERIC AM-KSF-40); and sulfobetaines such as lauryl
hydroxy sultaine (e.g. REWOTERIC~ AM-HC) and
cocamidopropyl hydroxysultaine (e. g. REWOTERIC AM-CAS).
Preferred R4 groups in formulas (IVa) and (IVb)
include alkyl and alkylene radicals derived from fatty
acids. Other preferred R' groups include benzyl, alkyl-
substituted benzyl, and saturated and unsaturated 5-
member and 6-member rings containing as the ring atoms
exclusively carbon, or carbon and 1 or 2 nitrogen atoms,
such as piperazine and alkyl-substituted piperazine. R4
can contain 4 to 40 carbon atoms, preferably 8 to 24
carbon atoms and more preferably 12 to 18 carbon atoms.
The filled emulsions of the present invention
2Q also include a filler component which is composed of
finely divided particulate material that does not react
chemically with the other components. Examples include
clay, synthetic or naturally occurring fibers, lime,
sand and/or carbon black. The particle size
distribution should be well below that of aggregate,
such as that which is bound with asphalt to create
paving material_ The particle size can be that of
conventional fillers currently used in coal tar asphalt
emulsions, but is preferably, generally about 0.5
m
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-14-
microns to about 0.01 millimeters up to about 2 or even
3-5 millimeters.
The emulsions of the present invention will of
course also contain water, and may contain other
components that can be present in filled asphalt
emulsions without interfering with the properties of the
filled emulsions of the present invention. Such
optional additional ingredients particularly include
but are not limited to fuel oil, kerosene, antistrip
agents, latex or other polymers compatible with the
emulsion, and agents such as thixotropicity agents to
adjust and control the viscosity of the final product.
When the intended end use is a product having
a relatively less viscous nature, such as for driveway
sealing, if the emulsifier present is an amphoteric the
viscosity can be adjusted as desired by addition of an
anionic or nonionic emulsifier (or both).
The relative amounts of the asphalt, the
aqueous phase, and the emulsifying component, are of
course a function of the fact that the product (whether
filled or unfilled) must take the form of an oil-in-
water emulsion of the asphalt in the aqueous phase as
the continuous phase. As such, then, the permissible
amounts of the asphalt, water, and emulsifying
components in the unfilled emulsion can vary. within
relatively large ranges, the asphalt comprising about 5
to about 85 or even 95 percent by weight of the
emulsion, and preferably the narrower range of about 50
to about 70 weight percent of the emulsion.
35
CA 02216173 1997-09-23
WO 96130446 PCT/US96104001
-15-
The filled emulsion contains about 10 to about
90 percent by weight of particulate filler, preferably
about 10 to about 70 percent by weight, and more
preferably about 10 to about 30 percent by weight of the
filled emulsion. The emulsifying component, as the
total effective amount of compounds of formulas (Ia),
(Ib), (II), and (III), defined above, will generally
comprise (but is not restricted to) about 0.1 to about
5_0 percent weight of the filled emulsion, and
preferably comprise the narrower range of about 0.2 to
about 2.0 weight percent of the emulsion. The water
generally comprises but is not restricted to about 20 to
about 70 percent by weight of the filled emulsion, or
more narrowly about 30 to about 50 weight percent of the
emulsion.
The pH of the emulsion can be about 1 to about
14, but is preferably about 7 to about 10. If pH
adjustment is necessary during formulation, it can be
accomplished by addition of small but effective amounts
of base such as sodium hydroxide or acid such as
sulfonic acid.
Preparation of the emulsion involves
relatively straightforward application of conventional
emulsification technology. The asphalt when emulsified
should preferably be in the form of very fine droplets
or particles having a diameter on the order o~ about 0_5
to about 50 microns, preferably about 5 to about 10
microns. To obtain particle sizes that permit
emulsification of the asphalt, the asphalt component
when formulated into the emulsion must be hot enough to
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-16-
be liquid but not so hot as to cause the aqueous phase
to boil off, which obviously would break the emulsion.
Emulsification can be carried out in a mill of
conventional design known to those of ordinary skill in
this art, such as a colloid mill, which simultaneously
intimately mixes the water, asphalt and emulsifying
components using high shear. The emulsifying compounds
used in the present invention can be added
simultaneously with the water and the asphalt, or more
Preferably can be dissolved in the water prior to
introduction of the asphalt into the resulting solution.
The desired filled asphalt emulsion is made by
mixing the filler(s), that is, fibers, clays, lime
and/or sand and/or other additives, into the emulsion.
Preferably, the filler components and water are pre-
mixed and then added to the emulsion after it is formed.
However, the filler components can be added per se, or
pre-mixed with. any other emulsion component,. and
combined with all the other components in the mill or
thereafter.
Asphalt emulsions prepared in accordance with
the present 'invention exhibit a number of advantageous
properties, notably, emulsions formed with the compounds
of the foregoing formulas (Ia) , (Ib) , (II) and/or (III) ,
resist breaking to a superior and unexpected degree even
when formulated with filling components, and even when
made with water, including i.e. "hard" water, containing
salts dissolved therein. In general, the emulsions
prepared in accordance with the present invention resist
generally "breaking" to a superior and unexpected degree
CA 02216173 1997-09-23
WO 96!30446 PCT/US96/04001
-17-
1 compared to emulsions prepared with other emulsifying
systems.
Another conspicuous advantage of the emulsions
of the present invention is that they permit the
formation of useful, stable asphalt emulsions while
' avoiding the use of coal tar and of products derived
from coal tar. It is desirable to avoid the use of coal
tar and its derivatives, as they have been implicated in
recent years as suspected carcinogens. However, as
discussed herein, the task of identifying suitable
materials providing the valuable properties afforded by
coal tar or its derivatives has not been achievable.
The present invention, however, satisfies that
significant objective.
The following examples are provided for
purposes of illustration and are not intended to limit
the scope of the present invention.
EXAMPLE 1
~ asphalt emulsion was prepared by combining
in a Charlotte G-5 colloidal emulsion mill, "AC-20"
asphalt (Ashland Oil Co.) and 2 wt.~ (by weight of the
emulsion) of a 35 wt.~ aqueous solution of "Witconate
AOS" (Witco Corp.), a mixture of alpha-olefin sulfonates
of formulas (Ia) and (Ib) set forth herein. The
solution had been prepared at 100°F. The asphalt was at
280-285°F when used to make the emulsion. The emulsion
had a pH of 7.8.
The resulting emulsion was stable and had
excellent quality. The emulsion was then mixed with
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-18-
1 varying amounts of a premixed Sealer "A" at room
temperature. Sealer "A" had the composition set forth
in Table A:
TABLE A
Lime 30 wt.o
Emulsion Grade Clay 4 wt.~
Silica Sand 12 wt.~
0 Bentonite Clay ~ wt-
1 Carbon Black 1 wt.~
Fiber 0.5 wt.~
Water 45.5 wt.~
The mixtures formed by mixing Sealer "A" with
the emulsion were assessed for physical state after 1-10
days, 30 days, and 60 days. Also, the performance was
observed when the mixtures were spread on a metal
surface and cured at room temperature. The results are
given in Table 1:
TABLE 1
Emulsions made with "Witconate AOS", mixed
with Sealer "A" (premixed) at room temperature.
30
CA 02216173 2001-07-27
~CF'-u'_-1J'-f'' l i: t=' f (_'.UP1 ~~~~~LLL'~' '~~~G( (- 'lIJ .
'_~lL~1s~34'_~c~3 P.24
Wn 9frJ3R4dfi FG'rlOS9GIiW(NI1
_Zg_
' 7,mt Amt . l ' Mixtzm~ Curing
, of of Ob~~~at
~ ioi~
tim,~l-:~CnSeai.~r of
",~"
(a9 wt,t (as wt,.~t MixCUre
of of
mixture) mixtu_r~)1-1.0
days
a0 da
r, 60
flays
70 30 VL'1"} 6dihe 83mC 9-G 3xYs.
as RS
thin, 1 day 1 clay cure/
Htai good
a
So 5U thi~t, same uame 4-6 lxrx.
as as
stable 1 day z day cure/
goad
40 60 thin, samR nrma 4-n' hrs.
as a..
rsi.aitsi.P1 day 1 day cure/
9~
30 70 Chin, olighr.lyname' a-6 Ura.
an
4table thick, 3u days cure/
good ood
25 75 'xlitlhtlyslightlysame 9-6 hrc.
ss
t.tlfCk,thick, .7. day CurE/
ntabl g~xxl ccr1
~ _
20 BP thick, ~ta!~e 'uvu,e 4-G hxs.
as a$
arable d,~y 1 day cmef
good
15 ~5 ' thick, aam~ name 9-G hra.
as as
arable , day 1 day cure/
good
Commei- thick, came name 4-G hrs.
as as
vial stable, t day 1 day Cuxe/
DXivewr~y R't i'7ht 9~
Sealer tlxixv-
tropic
the r.imes sea ~ortlt under the heading "Cuxing
of Mixture" in T~.hle 1 and tiii:zeaxter are thn . length of
time within whist the emulsiorx Cured and ~3ri~d Lo a
CCtd~ir)~ .
~_ ~ 2
Am ash>halt emul.siou was prepared usizxg "Emcpl
p CNP-1~0" (Wit.co Core. ) , a 10-male eC.hoxylate of xioxzyl
* trademark
CA 02216173 1997-09-23
WO 96/30446 PCT/US96/04001
-20-
1 phenol carboxylate anionic emulsifier in about 10 wt.~
water at 2.0~ use level (by weight of the emulsion).
Emulsifier solution pH was adjusted to 10.0 by addition
of NaOH. "AC-20" asphalt (Ashland) was used at 280°F to
make the emulsion in a Charlotte G-5 colloidal emulsion
mill. The above emulsion was then mixed at different
ratios with premixed Sealer "A" defined in Table A in
Example 1. Mixes were made at room temperature. The
performance of the resulting mixtures is set forth in
'Table 2.
TABLE 2
Emulsions made with "Emcol CNP-120", mixed
with Sealer "A" (premixed) at room temperature.
~-5 Amt. of Amt. of Mixture Curing
Observation
Emulsion Sealer "A.. Test
(as wt.% (as wt.% (2 grams
of of of
mixture) mixture) 1-10 days mixture)
30-60 days
70 30 thin, same as 4-6 hrs.,
stable 1 day good
50 50 thin, same as 4-6 hrs.,
stable 1 day slippery,
blackish
40 60 slightly same as rich,
thick 1 day blackish
30 70 thick, same as 4-6 hrs.,
stable 1 day good
2 25 75 thick, same as 4-6 hrs.,
c,
stable 1 day good
Commercial thick, same as 4-6 hrs.,
Sealer stable, 1 day good
thixotropic
35
CA 02216173 1997-09-23
WO 96!30446 PCT/LTS96/04001
-21-
EXAMPLE 3
1
An asphalt emulsion was prepared using as an
' anionic emulsifier dodecyl benzene sulfonate ("Witco
1298", Witco Corp.) at 2.0~ use level (by weight of the
emulsion). Emulsifier solution pH was adjusted to 10.0
by adding NaOH. "AC-20" asphalt (Ashland) was used at
280°F to make the emulsion. The emulsion was prepared
in a Charlotte G-5 colloidal emulsion mill. It was
mixed with premixed Sealer "A" at different ratios, at
room temperature. Sealer "A" had the composition set
forth in Table A, Example 1. The results are set forth
in Table 3.
TABLE 3
Emulsions made with "Witco 1298", mixed with
Sealer "A" (premixed) at room temperature.
Amt. of Amt. of Mixture Curing
Observation
Emulsion Sealer "A" Test
(wt.% (wt.% (2 grams
of of of
mixture) mixture) 1-10 days mixture)
30-60 days
40 60 very thin, same as 4-6 hrs.,
stable 1 day good
70 very thin, same as 4-6 hrs.,
stable 1 day good
20 80 thin, same as 4-6 hrs.,
2 stable 1 day good
c,
EXAMPLE 4
A coal tar emulsion was prepared using
"Witconate AOS" at 2.Oo use level (emulsion weight).
The emulsifier solution pH was 7.7, and was used as is.
35
CA 02216173 1997-09-23
WO 96/30446 PCTIUS96/04001
-22-
1 A coal tar sample was used which was fairly
soft at room temperature. An emulsion was manufactured
in a Charlotte G-5 colloidal emulsion mill by
emulsifying the coal tar at 200°F~with water and the
emulsifier. The resulting emulsion had a solids content
(coal tar) of 61.8~k.
The above emulsion was mixed with premixed
Sealer "A" defined in Table A, Example 1 at 50/50
(.weight: weight). The mixture was a stable emulsion.
EXAMPLE 5
Asphalt emulsions were prepared by emulsifying
asphalt in water with several different amphoteric
emulsifiers of formula (IVa) or (IVb). The components
and respective amounts were as follows; the pH was
adjusted to the indicated value by adding sodium
hydroxide:
Use level as wt.~
Emulsifier of emulsion ~HAsphalt
Cocamidopropyl 2.6 11 Ashland AC-20
dimethylbetaine
Cocamidopropyl 2.6 11 Chevron AC-20
hydroxy sultaine
Lauryl 2.6 11 Chevron AC-20
dimethyl betaine
Disodium coco- 2.6 11 Chevron AC-20
amphodiacetate
Combining each of these emulsions with Sealer
"A", at levels of about 70 wt.% Sealer "A" or higher at
120-130°F, gave smooth, thick, homogeneous emulsions.
When these products were spread out into films and
35
CA 02216173 1997-09-23
WO 9610446 PCT/ITS96/04001
-23-
cured, a smooth, continuous, durable layer formed in a
short period of time.
COMPARATIVE EXAMPLES
Tests conducted with some other emulsifiers
were unable to produce stable filled asphalt emulsions.
These results demonstrated that the success of the
particular selection of emulsifiers embodied in the
present invention is quite unexpected. For instance, a
tyl.~lca1 anionic emulsifier such as tall oil fatty acids
commonly used for manufacturing of rapid-medium set type
asphalt emulsions at range of 0.4 to 0.6~ use levels,
did not produce a stable, filled asphalt emulsion, even
at 0.6~ and at 1.0~ use level (by weight of the
emulsion). The emulsifier solution pH was adjusted to
10.0 by adding NaOH. "AC-20" asphalt (Ashland) was used
at 280~F to manufacture the emulsion in a Charlotte G-5
colloidal emulsion mill. The resulting emulsion, after
24 hours storage at room temperature, was mixed with
Sealer "A" defined in Table A, Example 1. The results
were broken, incompatible emulsions.
Similar tests conducted with cationic
emulsifiers, even at higher use levels, demonstrated
that cationic emulsifiers could not form a stable
emulsion containing as filler fine materials such as
clay, lime, fiber, and sand used in driveway sealer
application. Emulsion/Sealer "A" mixtures at 50:50
ratio formed incompatible, broken emulsions.
35
