Note: Descriptions are shown in the official language in which they were submitted.
SPRAYABLE AND POURABLE POLYZJREA ELASTOMER
(D#80, 826 _r~
BACRGROOND OF THE INVENTION
1. Field of the Invention
The present invention relates to sprayable and
pourable polyurea elastomers which include novel chain extenders.
2. Description of Background Art
Elastomer systems are commonly recognized as, among
other things, coating materials, with spray polyurea elastomer
systems being particularly useful when employed in this capa-
city. One of the considerations confronting the skilled
artisan is the sprayability of the elastomer during the
critical period, that is, the point at which. the reactive
components are combined up through the point at which gelation
occurs. Similarly, the pourability of the elastomer during the
critical period also concerns the skilled artisan where the
elastomer is to be poured into an open mold, such as in
electric potting type work.
Polyurea elastomer systems are generally prepared by
reacting an,isocyanate with an active hydrogen component in the
presence of a chain extender. Certain known chain extenders
react very rapidly with the isocyanate component and, therefore,
are not well suited for spray or pour systems, inasmuch as poly-
merization or gelation occurs so rapidly that the elastomer is
virtually unsprayable and unpourable. One of the most widely -
employed chain extenders is diethyltoluene diamine (DETDA), a
product of Ethyl Corporation. Polyurea elastomer systems
fabricated from, among other things, DETDA generally exhibit good
processing characteristics.
pr\dgv02 -1-
~o~~~~~
However, one of the shortcomings associated with elastomer
systems fabricated with DETDA, where sprayable and/or pourability
are at issue, is the rapid gelation time. The polyurea
elastomer system of the present invention includes a chain
extender that reacts slower with the isocyanate component and,
accordingly, the rate at which the elastomer will gel is reduced
resulting in improved flowability, thereby permitting the
elastomer to be sprayed and/or poured. In addition, the polyurea
elastomer system of the present invention exhibits certain
properties which are similar to or bettter than those exhibited
by systems fabricated from DETDA.
U.S. Patent No. 3,979,364 describes the use of aminated
polyethers as hereinafter used as a component with a polyol to
make an elastomer. U.S. Patent No. 3,666,788 describes the use
of cyanoalkylated aminated polyethers in spray systems. The '788
disclosure, in Column 1, states that the aminated polyethers as
used hereinafter cannot be used in spray coatings due to very
rapid reaction rates with isocyanates.
zo
U.S. Patent Nos. 4,379,729; 4,444,910 and 4,433,067
describe elastomers which are prepared using a high molecular
weight amine terminated polyether, an aromatic diamine chain
extender and an aromatic polyisocyanate which may merely be a
polyisocyanate or a quasi-prepolymer prepared from a polyol
reacted with a polyisocyanate wherein some isocyanate groups
are still left unreacted. Various patents have been applied
for and received using the basic combination recited above as
well as various mold release agents and other additives, such
as catalysts and fillers, including glass fibers. For example,
see U.S. Patent No. 4,607,090.
U.S. Patent No. 3,714,128 describes cyanoalkylated
polyoxyalkylene polyamines which are useful for slowing the
gelling or hardening of the polyurea component so that good
pr\dgv02
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203~~~~
mixing of the isocyanate and amine components can be attained,
which gives the sprayed material ample time to adhere and level
before gelation of the polyurea coating occurs. This patent
does not describe the particular chain extenders employed in
the elastomer of the present invention.
U.S. Patent No. 4,714,778 describes certain alkenylated
toluene diamines which are reported as being useful as tri- and
tetrafunctional chain extenders for forming polyurethane-urea
l0 elastomers.
U.S. Patent No. 4,816,543 describes a monotertiary-
alkyltoluene diamine which is reported as being useful as a chain
extending agent for the formation of polyurethane-urea
elastomers. At least 50% of the equivalent weight of the chain
extending agent is mono-tertiary-butyltoluene diamine.
U.S. Patent No. 4,806,615 describes reaction injection
molded (RIM) elastomers consisting of a cured reaction product of
primary or secondary amine terminated polyethers of greater than
1500 molecular weight, an aromatic polyisocyanate, a combination
of an unsubstituted aromatic diamine chain extender and a
substituted acyclic aliphatic diamine chain extender.
U.S. Patent No. 4,218,543 describes the use of high
molecular weight polyols, certain aromatic diamines and
isocyanates, for the production of RIM parts. This patent
specifically claims as a chain extender 1-methyl-3,5-diethyl-2,4-
diaminobenzene (diethyltoluenediamine) and its isomer.
U.S. Patent No. 4,523,004 discloses a substituted
aromatic diamine chain extender in a RIM product.
U.S. Patent No. 4,631,298 discloses blending various
slower reacting chain extenders with diethyltoluene diamine in a
RIM system using amine terminated polyethers.
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CA 02034169 1998-10-27
Thus, it is our understanding that a polyurea elastomer
system which incorporates the particular chain extenders
described hereinbelow and which is sprayable and/or pourable has
heretofore been unavailable.
SUMMARY OF THE INVENTION
Accordingly, the present invention relates to a
polyurea elastomer which comprises an (A) component and a (B)
component. The (A) component includes an isocyanate.
Preferably, the isocyanate of component (A) includes a quasi-
prepolymer of an isocyanate and a material selected from at least
one polyol, a high molecular weight polyoxyalkyleneamine or a
combination of these materials. The (B) component includes (1)
an amine terminated polyoxyalkylene polyol and (2) a chain
extender which includes at least di(methylthio)-toluene diamine.
Preferably, the chain extender includes a combination of
di(methylthio)-toluene diamine and diethyltoluene diamine
(DETDA).
The present invention also relates to a method for
improving the flowability of a polyurea elastomer thereby
permitting said elastomer to be sprayed or, optionally, poured.
Specifically, the present method comprises incorporating a chain
extender including at least di(methylthio)-toluene diamine into
the elastomer. The di(methylthio)-toluene diamine is employed in
an amount sufficient to reduce the time in which the elastomer
will gel, thereby improving the flowability of the elastomer. A
first and second reactive st ream are directed into mutual contact
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75704-114
CA 02034169 1998-10-27
with each other to effectuate a mixing of the first and second
reactive streams. The first reactive stream includes an
isocyanate and the second reactive stream includes an amine
terminated polyoxyalkylene polyol and the aforedescribed chain
extender. The mixed first and second reactive streams are
sprayed or, optionally, poured onto or, optionally, into a
subst rat a .
According to one aspect of the present invention there
is provided a sprayable polyurea elastomer comprising an (A)
component which includes an isocyanate and a (B) component which
includes (1) an amine terminated polyoxy-alkylene polyol and (2)
a chain extender, said chain extender including a blend of
di(methylthio)-toluene diamine and diethyltoluene diamine, said
chain extender including between 71 and about 80 wt.~
diethyltoluene diamine based upon the total weight of said chain
extender.
According to a further aspect of the present invention
there is provided a sprayable polyurea elastomer comprising an
(A) component which includes a quasi-prepolymer of an isocyanate
and a material selected from at least one polyol, a high
molecular weight polyoxyalkyleneamine or a combination of said
materials; and a (B) component which includes (1) an amine
terminated polyoxyalkylene polyol and (2) a chain extender
including a blend of di(methylthio)-toluene diamine and
diethyltoluene diamine, said chain extender including between 71
and about 80 wt.$ diethyltoluene diamine based upon the total
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75704-114
CA 02034169 2002-O1-17
75704-114
weight of said chain extender.
According to another aspect of the present
invention there is provided a method for improving the
flowability of a sprayable polyurea elastomer, thereby
permitting said elastomer to be sprayed, said method
comprising the steps of: a) providing a first reactive
stream which includes an isocyanate; b) providing a second
reactive stream which includes: i) an amine terminated
polyoxyalkylene polyol; and ii) a chain extender including a
blend of di(methylthio)-toluene diamine and diethyltoluene
diamine, said di(methylthio)-toluene diamine being present
in an amount sufficient to reduce the rate at which said
elastomer will gel thereby improving the flowability of said
elastomer, and said diethyltoluene diamine being present in
an amount between 71 and about 80 wt% based upon the total
weight of said chain extender; c) directing said first and
said second reactive streams into mutual contact with each
other to effectuate a mixing of said first and second
reactive streams; and d) spraying said mixed first and
second reactive streams onto a substrate.
- 4b -
20~~1~~
Advantageously, when the chain extenders disclosed
herein are used to prepare the elastomer of the present inven-
tion, the rate at which gelation will occur is reduced resulting
in improved flowabil.ity, thereby permitting the elastomer to be
sprayed during the aforestated critical period. The reduced
reactivity and resulting improved flowability also permits the
present elastomer to be used in a pour gun for electrical potting
work and small mold filling work. In addition to satisfying the
criteria of sprayability and/or pourability, the present elastomer
also exhibits improved elongation and spray surface quality, as
well as good processability, appearance and toughness.
DESCRIPTION OF THE PREFERRED EM80DIMENTS
The isocyanates employed in component (A) are those
known to one skilled in the art. Thus, for instance, they can
include aliphatic isocyanates of the type described in U.S.
Patent No. 4,748,192. Accordingly, they are typically aliphatic
diisocyanates, and, more particularly, are the trimerized or the
biuretic form of an aliphatic diisocyanate, such as hexamethylene
diisocyanate, or the bifunctional monomer of the tetraalkyl
xylene diisocyanate, such as the tetramethyl xylene diisocyanate.
Cyclohexane diisocyanate is also to be considered a preferred
aliphatic isocyanate. Other useful aliphatic polyisocyanates are
described in U.S. Patent No. 4,705,814. They include aliphatic
diisocyanates, for example, alkylene di.isocyanates with 4 to 12
carbon atoms in the alkylene radical, such as 1,12-dodecane
diisocyanate and 1,4-tetramethylene diisocyanate. Also described
are cycloaliphatic diisocyanates, such as I,3 and 1,4-cyclohexane
diisocyanate as well as any desired mixture of these isomers,
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane
(isophorone diisocyanate); 4,4'-,2,2'- and 2,4'-dicyclohexyl-
methane diisocyanate as well as the corresponding isomer
mixtures, and the like.
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A wide variety of aromatic polyisocyanates may be used
to form the elastomer of the present invention. Typical aromatic
polyisocyanates include p-phenylene diisocyanate, polymethylene
polyphonylisocyanate, 2,6-toluene diisocyanate, dianisidine
diisocyanate, bitolylene diisocyanate, naphthalene-
1,4-diisocyanate, bis(4-isocyanatophenyl)methane, bis(3-methyl-
3-isocyanatophenyl)methane, bis(3-methyl-4-isocyanatophenyl)-
methane, and 4,4'-diphenylpropane diisocyanate.
Other aromatic polyisocyanates used in the practice of
the invention are methylene-bridged polyphenyl polyisocyanate
mixtures which have a functionality of from about 2 to about 4.
These latter isocyanate compounds are generally produced by the
phosgenation of corresponding methylene bridged polyphenyl
polyamines, which are conventionally produced by the reaction of
formaldehyde and primary aromatic amines, such as aniline, in the
presence of hydrochloric acid and/or other acidic catalysts.
Known processes for preparing polyamines and corresponding
methylene-bridged polyphenyl polyisocyanates therefrom are
described in the literature and in many patents, for example,
U.S. Patent NOS. 2,683,730; 2,950,263; 3,012,008; 3,344,162 arid
3,362,979.
Usually methylene-bridged polyphenyl polyisocyanate
mixtures contain about 20 to about 100 weight percent methylene
diphenyldiisocyanate isomers, with the remainder being polyme
thylene polyphenyl diisocyanates having higher functionalities
and higher molecular weights. Typical of these are polyphenyl
polyisocyanate mixtures containing about 20 to 100 weight
percent diphenyldiisocyanate isomers, of which 20 to about 95
weight percent thereof is the 4,4'-isomer with the remainder
being polymethylene polyphenyl polisocyanates of higher molecu
lar weight and funtionality that have an average functionality
of from about 2.1 to about 3.5. These isocyanate mixtures are
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~Q~4~.~~
known, commercially available materials and can be prepared by
the process described in U.S. Patent No. 3,362,979.
By far the most preferred aromatic polyisocyanate is
methylene bis(4-phenylisocyanate) or MDI. Pure MDI, quasi-
prepolymers of MDI, modified pure MDI, etc. are useful.
Materials of this type may be used to prepare suitable RIM
elastomers. Since pure MDI is a solid and, thus, often incon-
venient to use, liquid products based on MDI or methylene
bis(4-phenylisocyanate) are used herein. U.S. Patent No.
3,394,164 describes a liquid MDI product. More generally,
uretonimine modified pure MDI is included also. This product is
made by heating pure distilled MDI in the presence of a catalyst.
The liquid product is a mixture of pure MDI and modified MDI and
is represented as follows:
2 [ CN ~ CH2 ~ -NCO ]
Catalyst
OCN ~ CH2 ~ N=C=N ~ CH2 ~ -NCO + C02
Carbodiimide
OCN ~ CH2 ~ N r =N ~ CH2 ~ NCO
0=~-N ~ CH2 ~ NCO
Uretonimine
Examples of commercial materials of this type are Dow's ISONATE~
125M (pure MDI) and ISONATE 143L ("liquid" MDI). Preferably the
amount of isocyanates used is the stoichiometric amount based on
all the ingredients in the formulation or greater than the
stoichiometric amount.
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Of course, the term isocyanate also includes quasi-
prepolymers of isocyanates or polyisocyanates with active
hydrogen containing materials. The active hydrogen containing
materials can include, but are not limited to, a polyol or
polyols, a high molecular weight polyoxyalkyleneamine or
combinations thereof.
The polyols include polyether polyols, polyester
diols, triols, tetrols, etc., having an equivalent weight of at
least about 500, and preferably at least about 1,000 up to
about 3,000. Those polyether polyols based on trihydric
initiators of about 4,000 molecular weight and above are
especially preferred. The polyethers may be prepared from
ethylene oxide, propylene oxide, butylene oxide or mixtures of
propylene oxide, butylene oxide and/or ethylene oxide. Other
high molecular weight polyols which may be useful in this
invention are polyesters of hydroxyl terminated rubbers, e.g.,
hydroxyl terminated polybutadiene. Hydroxyl terminated quasi
prepolymers of polyols and isocyanates are also useful in this
invention.
Especially preferred are amine terminated polyether
polyols, including primary and secondary amine terminated poly-
ether polyols of greater than 1,500 average molecular weight
having from about 2 to about 6 functionality, preferably from
about 2 to about 3, and an amine equivalent weight of from about
750 to about 4,000. Mixtures of amine terminated polyethers may
be used. In a preferred embodiment the amine terminated poly-
ethers have an average molecular weight of at least about 2,500.
These materials may be made by various methods known in the art.
The amine terminated polyether resins useful in this
invention, for example, are polyether resins made from an
appropriate initiator to which lower alkylene oxides, such as
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CA 02034169 2001-04-03
75704-114
ethylene oxide, propylene oxide, butylene oxide or mixtures
thereof, are added with the resulting hydroxyl terminated
polyol then being aminat=ed.
When two or more oxides are used, they may be present
as random mixtures or a;~ blocks of one or the other polyether.
In the amination step it, is highly desirable that the terminal
hydroxyl groups in the polyol be essentially all secondary
hydroxyl groups for ease of amination. Normally, the amination
step does not completely replace all of the hydroxyl groups.
However, the majority of= hydroxyl groups are replaced by amine
groups. Therefore, in a preferred embodiment, the amine
terminated polyether re:~ins useful in this invention have
greater than 50 percent of their active hydrogens in the form
of amine hydrogens. If ethylene oxide is used it is desirable
to cap the hydroxyl terminated polyol with a small amount of
higher alkylene oxide to ensure that the terminal hydroxyl
groups are essentially all secondary hydroxyl groups. T'he
polyols so prepared are then reductively aminated by known
techniques, for example, as described in U.S. Patent No.
3,654,370.
In the practice of this invention, a single high
molecular weight amine terminated polyol may be used. Also,
mixtures of high molecular weight amine terminated polyols,
such as mixtures of di- and trifunctional materials and/or
different molecular weight or different chemical composition
materials, may be used.
Also, high molecular weight amine terminated
polyethers or simply polyether amines are included within the
scope of our invention and may be used alone or in combination
with the aforestated polyols. The term high molecular weight
is intended to include polyether amines having a molecular
weight of at least about 2000. Particularly preferred are the
JEFFAMINE~ series of
9
polyether amines available from Texaco Chemical Company; they
include JEFFAMINE D-2000, JEFFAMINE D-4000, JEFFAMINE T-30f0 and
JEFFAMINE T-5000. These polyether amines are described with
particularity in Texaco Chemical Company's product brochure
entitled THE JEFFAMINE POLYOXYALKYLENEAMINES.
The (B) component of the present polyurea elastomer
system includes an amine terminated polyoxyalkylene polyol and
a chain extender. The amine terminated polyoxyalkylene polyol
is preferably selected from diols or triols and, most preferably,
includes a blend of diols and/or triols. The particular polyols,
i.e., diols and/or triols, employed in component (B) are the same
as those described hereinabove in connection with the quasi-pre-
polymer of component (A).
The chain extenders useful in this invention include
di(methylthio)-toluene diamine, either used alone or, in a
preferred embodiment, in combination with, 1-methyl-3,5-diethyl-
2,4-diaminobenzene or 1-methyl-3,5-diethyl-2,6-diaminobenzene
(both of these materials are also called diethyltoluene diamine
or DETDA).
The aforestated combination includes from about
20 to about 99 parts of di(methylthio)-toluene diamine to about
80 to about 1 parts of DETDA.
One particularly preferred form of the di(methylthio)-
toluene diamine component of the chain extender is as Ethacure~
300, a product of Ethyl Corporation. Specifically, Ethacure 300
is a 4:1 blend of 3,5-di(methylthio)-2,4-toluene diamine and 3,5
di(methylthio)-2,6-toluene diamine, respectively.
Advantageously, the (A) and (B) components react to
form the present elastomer system without the aid of a catalyst.
gowever, if desired, a catalyst can be used.
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Catalysts such as tertiary amines or an organic tin
compound may suitably be a stannous or stannic compound, such as
a stannous salt of a carboxylic acid, a trialkyltin oxide, a
dialkyltin dihalide, a dialkyltin oxide, etc., wherein the
organic groups of the organic portion of the tin compound are
hydrocarbon groups containing from 1 to 8 carbon atoms. For
example, dibutyltin dilaurate, dibutyltin diacetate, diethyltin
diacetate, dihexyltin diacetate, di-2-ethylhexyltin oxide,
dioctyltin dioxide, stannous octoate, stannous oleate, etc., or
a mixture thereof, may be used.
Tertiary amine catalysts include trialkylamines (e. g.,
trimethylamine, triethylamine); heterocyclic amines, such as
N-alkymorpholines (e. g., N-methylmorpholine, N-ethylmorpholine,
dimethyldiaminodiethylether, etc.), 1,4-dimethylpiperazine, trie-
thylenediamine, etc.: and aliphatic polyamines, such as N,N,N~N~
tetramethyl-1,3-butanediamine.
Other conventional fomulation ingredients may be
employed in component (A) or (B) as needed, such as, for
example, foam stabilizers, also known as silicone oils or
emulsifiers. The foam stabilizers may be an organic silane or
siloxane. For example, compounds may be used having the
formula:
RSi[O-(R2Si0)n-(oxyalkylene)mR)3
wherein R is an alkyl group containing from 1 to 4 carbon
atoms; n is an integer .of from 4 to 8; m is an integer of from
20 to 40; and the oxyalkylene groups are derived from propylene
oxide and ethylene oxide. See, for example, U.S. Patent No.
3,194,773.
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2~3t~1~~
Pigments, far example titanium dioxide, may be
incorporated in the elastomer system, preferably in the (B)
component, to impart color properties to the elastomer.
Post curing of the elastomer of the invention is
optional. Post curing will improve some elastomeric proper-
ties, such as heat sag. Employment of post curing depends on
the desired properties of the end product.
The (A) component and (B) component of the present
polyurea elastomer system are combined or mixed under high
pressure; most preferably, they are impingement mixed directly
in the high pressure equipment, which is, for example, a GUSMER~
H-V proportioner fitted, for instance, with a GUSMER Model GX-7
spray gun. In particular, a first and second pressurized stream
of components (A) and (B), respectively, are delivered from two
separate chambers of the proportioner and are impacted or
impinged upon each other at high velocity to effectuate an
intimate mixing of the two components and, thus, the formation
of the elastomer system, which is then coated onto the desired
substrate via the spray gun.
As stated above, the polyurea elastomer of the present
invention can also be used in a pour gun for electric potting
type work or other open mold work that involves pouring. When
used in this capacity, the (A) and (B) components are mixed in
the same manner as described above. However, the high pressure
spray equipment is fitted with a pour gun, such as a GUSMER model
AR-C pour gun, instead of a spray gun.
Whether the elastomer of the present invention is to be
sprayed or poured, the volumetric ratio of the (A) component to
the (B) component is generally from about 30 to 70 percent to
about 70 to 30 percent. Preferably, component (A) and component
(g) are employed in a 1:1 volumetric ratio.
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GLOSSARY OF TERMS AN1D MATERIALS
ISONATE~ 143 L - Carbodiimide modified liquid MDI; a
product of the Dow Chemical Company.
THANOL~ SF-5505 - A 5500 molecular weight polyether triol
containing approximately 80% primary
hydroxide groups; a product of ARCO Chemical
Company.
ETHACURE~ 300 - a 4:1 blend of 3,5-di(methylthio)-2,4-tol-
uene diamine and 3,5-di(methylthio)-2,6-
toluene diamine; a product of Ethyl
Corporation.
JEFFAMINE~ T-5000 - Polypropylene oxide triamine of about 5000
molecular weight; a product of Texaco
Chemical Company.
JEFFAMINE~ T-3000 - Polypropylene oxide triamine of about 3000
molecular weight; a product of Texaco
Chemical Company.
JEFFAMINE~ D-4000 - Polypropylene oxide diamine of about 4000
molecular weight; a product of Texaco
Chemical Company.
JEFFAMINE~ D-2000 - Polypropylene oxide diamine of about 2000
molecular weight; a product of Texaco
Chemical Company.
The following examples are provided to further
illustrate preferred embodiments of the present invention and
should not be construed as limiting the present invention in
any way.
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In the examples, all spray work was performed with a
GUSMER H-V high pressure proportioner fitted with a GUSMER model
GX-7 spray gun or a GUSMER model AR-C pour gun, where appro-
priate. The elastomer systems were sprayed and poured using a
block temperature of 160°F on the (A) component side and 150°F
to
160°F on the (B) component side, with a hose temperature of
160°F. The system output ranged from 17.5 lbs/min to 22.5
lbs/min with a line pressure ranging from 1400 to 2800 psig on
the (A) component side and (B) component side. Each of the
l0 elastomer systems produced in the examples were mixed at an
(A):(B) volumetric ratio of 1:1.
EXAMPLE I
The (A) component of a polyurea elastomer was
prepared by combining 60 parts of ISONATE 143L and 40 parts of
THANOL SF-5505 to form a quasi-prepolymer. The (H) component
was prepared by combining 63.75 parts of JEFFAMINE D-4000, 25.0
parts of DETDA and 11.25 parts of Ethacure 300. The (A) and
(B) components were mixed in the high pressure equipment, which
was fitted with a pour gun. The resulting elastomer was poured
into and filled a 10" x 10" x 0.125" plaque mold.
COMPARATIVE EXAMPLE I A)
The (A) component of the polyurea elastomer produced
in this example was prepared in accordance with Example I. The
(B) component was prepared by combining 65.8 parts of JEFFAMINE
D-4000 with 34.2 parts of DETDA. The (A) and (B) components
were mixed in the high pressure equipment, which was fitted with
a pour gun. The resulting elastomer was poured into and par-
tially filled (850) a 10" x l0" x 0.125" plaque mold.
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~o~~.~o~
The physical properties of the polyurea elastomers
produced in Example I and Comparative Example I(A) were analyzed:
the results as well at the respective gel times are reported in
Table I.
TABLE I
COMPARATIVE
PROPERTIES
EXAMPLE I EXAMPLE I(A)
Gel Time (sec.) 2.6 1.5
Tensile (psi) 2785 3402
Elongation (%) 290 280
Tear (pli) 621 639
Shore D hardness (0 sec.) 62 66
(10 sec.) 57 60
Flexural Modulus (psi) 69233 63679
(77"F)
As these data demonstrate, the polyurea elastomer of
the present invention (Example I) exhibits a gel time that is
far slower than that exhibited by an elastomer which is devoid
of the chain extenders described herein (Comparative Example
I(Aj). The elastomer produced in Comparative Example I(A) was
pourable; however, the flowability was noticeably inferior to
that exhibited by the elastomer of Example I. Additional
properties, such as elongation and flexural modulus, are also
improved.
EXAMPLE II
The (Aj component of the polyurea elastomer produced
in this example was prepared in accordance with Example I. The
(B) component was prepared by combining 64.0 parts of JEFFAMINE
T-5000, 26.9 parts of DETDA and 9.1 parts of Ethacure 300.
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5
The (A) and (B) components were mixed in the high pressure
equipment, which was fitted with a model GX-7 spray gun. The
resulting elastomer was sprayed onto a flat metal substrate
coated with a zinc stearate based external mold release agent.
COMPARATIVE EXAMPLE II(A)
The (A) component of the polyurea elastomer produced
in this example was prepared in accordance with Example I. The
(B) component was prepared by combining 66.0 parts of JEFFAMINE
T-5000 and 34.0 parts of DETDA. The resulting elastomer was
sprayed onto the substrate as in Example II.
The physical properties of the polyurea elastamers
produced in Example II and Comparative Example II(A) were
analyzed; the results as well as the respective gel times are
reported in Table II.
TABLE II
COMPARATIVE
PROPERTIES EXAMPLE II EXAMPLE IIIA)
Gel Time (sec.) 2.5 1.5
Tensile (psi) 1872 1918
Elongation (%) 130 117
Tear (pli) 424 403
Shore D hardness (0 sec.)53 50
(10 sec.)49 47
Flexural Modulus (psi)
(77F) 43693 42900
(158F) 33861 36822
(-20F) 84848 83241
Heat sag (mm)
100 mm - 250F/60 min 1.0 0
25
.
150 mm - 250F/60 min 4.p 1,g
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These data further establish the reduced gel time
exhibited by the polyurea elastomer of the present invention.
Again, these data establish the superiority of certain other
properties. It is also noted that upon visual. inspection of the
elastomers produced in Example II and Comparative Example II(A),
the elastomer of the present invention exhibited a smoother
surface, indicating improved flowability, than the elastomer
produced in Comparative Example II(A).
EXAMPLE IIT
The (A) component of the polyurea elastomer produced
in this example was prepared in accordance with Example I. The
(B) component was prepared by combining 63.2 parts of JEFFAMINE
D-4000, 21.6 parts of DETDA and 15.2 parts of Ethacure 3000.
The (A) and (B) components were mixed in the high pressure
equipment and were sprayed onto the substrate as in Example II
and Comparative Example II(A).
The physical properties of the polyurea elastomer
produced in Example III were analyzed; the results as well as
the gel time are reported in Table III.
TABLE ITI
PROPERTIES EXAMPLE III
Gel Time (sec.) 2.5
Tensile (psi) 1976
Elongation (%) 190
Tear (pli) 459
Shore D hardness (0 sec/10 sec.) 56/49
Flexural Modulus (psi)
(77°F) 35142
(158°F)
24772
(-20°F) 91988
Heat sag (mm)
100 mm -250°F/60 min 1l.1
100 mm -311°F/60 min 38.1
150 mm -250°F/60 min 20,4
150 mm -311°F/60 min complete sag
pr\dgv02
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