Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
10~ 14
BACKGROUNO O~' THE INVENTION
This invention relates to the production of poly-
ether polyol compositions; and more particularly to a method
of producing polyether polyol compositions ~hich contain
alxoxyalkanol amines by oxyalkylating a polyhydric initiator
in the presence of an aqueous ammonia solution.
PRIOR ART
Polyoxyalkylene polyols or polyether polyols are
well known. Such polyether polyols are known to be formed
by the reaction of a polyhydric compound having from about 2
8 hydroxyl groups with a 1,2-epoxide such as ethylene oxide,
propylene oxide or higher alkylene oxide in the presence of
a basic catalyst such as aqueous sodium or potassium hydro-
xide. The polyether polyols pro~uced are useful as react-
ants with isocyanate containing compounds to form polyure-
thane material and particularly polyurethane foams.
The above-mentioned method of producing polyether
polyols is less than desirable, however, in that the reac-
tion requires a subsequent refining step which includes the
neutralization of the caustic alkali catalyst with subsequent
removal of the precipitated salts. In addition~ the presence
of aqueous caustic alkali in the reaction medium is known to
facilitate undesirable side ractions. Specifically, the
alkylene oxide and water combine to produce diols. These
diols tend to decrease the functionality of more desirable
higher functionality polyol compositions.
In an effort to avoid the subsequent refinement
step and/or the production of diols, various methods have
been proposed. For example, oxyalkylation of the relatively
high melting polyhydric initiators has been proposed where
the solid initiators are fused at high temperatures in the
.~
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~06S314
presence of an alkylene oxide. This method, while avoiding
the disadvantages of the previous method, damages and dis-
colors the final product because of the high temperatures
required. Other proposed methods involve the use of non-
aqueous solvents with a compatible basic substance; however,
most of these methods require catalyst removal and/or solvent
recovery prior to using the produced polyols in polyurethane
foams. For example, it has been disclosed that certain
amine compounds can be utilized as both a solvent and a
catalyst for polyether polyol production. One process, as
disclosed in U.S. Patent 2,902,476, uses lower alkyl tertiary
amines and, specifically triethyl-, trimethyl- and tripropyl-
amines, as a solvent and a catalyst in the reaction of pro-
pylene oxide with polyhydric ini~iators. Water is specifi-
cally excluded from the reaction mixture.
While this process eliminates the inherent diffi-
culties encountered with aqueous reaction mediums, it
involves the use of expensive, purified solvents. Addition-
ally, trialkyl amines are poor initiator solvents. Thus,
large amounts of amine solvent are required in order to form
the desirable single phase reaction mixture. The presence of
large quantities of trialkyl amines in the polyol product is
not desirable. Specifically, such substances are highly
odoriferous in urethane foam products and strongly catalyze
isocyanate-polyol reactions. Therefore, small amounts of
these substances must be utilized and/or the solvent must be
removed from the polyether polyol composition prior to foam
formation, thus requiring a removal step. When small amounts
of tertiary alkyl amines are utilized, the amount of solvent
is insufficient to form a homogeneous single-phase reaction
media. The resulting solid-liquid-gas heterogeneous reaction
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10tj5314
is difficult to adequately control.
Another such process disclosed in U.S. Patent
3,332,934, utilizes a triethanolamine catalyst-solvent for
the reaction of propylene oxide with a polyhydric initiator.
As in the previously disclosed process, the reaction pro-
ceeds in the absence of water. Pure triethanolamine like
trimethylamine is relatively expensive. Likewise, triethanol-
amine is a poor initiator solvent. When those amounts of
triethanolamine required to produce polyols of desirable
hydroxyl number, i.e. from about 400 to 600, are utilized,
a heterogeneous slurry of the solid polyhydric material is
formed. Thus the oxyalkylation occurs in a gas-liquid-solid
phase reaction. As mentioned hereinbefore, such a system is
difficult to control with the rate being determined by the
solubility of the solid initiator. The time of reaction
ranges from 7 to about 20 hours. If larger amounts of
triethanolamine are utilized, a reformulation of the
catalyzed polyol-isocyanate foam reaction is required.
Further, some of the polyether polyols produced
using pure triethanolamines exhibit viscosities which render
them difficult to ship and use in standard urethane systems.
Attempts to use solvents, such as for example a fluorocarbon,
in order to reduce viscosities limits the use of the poly-
ether polyols in producing low density foam compositions.
Therefore, a process for producing polyether polyols, which
is compatible with urethane systems, is relatively easy to
control,uses relatively inexpensive starting materials but
does not suffer the inherent drawbacks of caustic alkali
catalyzed systems, would be desirable.
Unexpectedly it has been found that suitable poly-
ether polyols, including those having hydroxyl numbers from
106531~
about 400 to about 650 with viscosities from about 1,000 to 20,000 centipoise,
can be produced in a single process utilizing the relatively inexpensive
starting materials of aqueous ammonia, and one or more alkylene oxides with
a polyhydric initiator. The reactions proceed relatively fast in a homogen-
eous reaction media at lower temperatures. The ammonia itself becomes oxy-
alkylated producing alkoxyalkanol amines which are compatible with urethane
systems and need not be removed prior to the polyol-isocyanate reaction.
These alkoxyalkanol amines increase the blending compatibility of the polyol
compositions with other polyols. Surprisingly, the production of diols is
relatively small and no refinement step is necessary to remove the nitrogen
containing moiety. Further, it has been unexpectedly found that by varying
the amounts (concentration) of the ammonia initially added, the viscosities
of the polyether polyols produced can be effectively lowered without material-
ly affecting properties of the foam produced therefrom.
SUMMARY OF THE INVENTIoN
In one aspect of the invention there is provided a method for pro-
ducing polyether polyol compositions comprising the step of: intimately
contacting at least one alkylene oxide having from 2 to 4 carbon atoms or
mixtures thereof with an aliphatic polyhydric nonreducing initiator having
from about 2 to 8 hydroxyl moieties per molecule at lower temperatures of
from about 30 C to 150 C in the presence of an effective amount of an aqueous
ammonia solution.
In another aspect there is provided a method for producing a poly-
ether polyol composition comprising the steps of: initially forming an
aqueous initiator-ammonia admixture wherein the initiator is an aliphatic
polyhydric nonreducing compound having from about 2 to 8 hydroxyl moieties
per molecule~ intimately contacting at least one alkylene oxide having from
2 to 4 carbon atoms or mixtures thereof with said aqueous initiator-ammonia
admixture at temperatures within a range of from about 30 to about 150 C
~ _ 4 _
¢i
10653~4
to form said polyether polyol composition.
In yet another aspect there is provided a method for producing a
polyether polyol composition comprising the steps of: initially forming
homogeneous aqueous initiator-ammonia admixture wherein the initiator is an
aliphatic polyhydric nonreducing compound having from about 3 to 8 hydroxyl
moieties per molecule by initially admixing said initiator in sufficient water
to form a substantially homogeneous aqueous initiator solution, and contacting
said aqueous initiator solution with a compound selected from ammonia, ammon-
ium hydroxide, and mixtures thereof in amounts sufficient to form an aqueous
initiator-ammonia admixture containing from about 10 to about 100 parts by
weight initiator to about 1 part by weight of ammonia; heating said initiator
ammonia admixtùre to temperatures of about 40 C; intimately contacting the
heated aqueous initiator ammonia mix~ure with from 2 to 12 moles of ethylene
oxide per mole of initiator at temperatures of from about S0 C to about 60 C
to form an aqueous reaction product; and intimately contacting said aqueous
reaction product with from about 8 moles to about 20 moles propylene oxide
per mole of initiator at temperatures from about 105 C to about 115C to form
said polyether polyol composition.
According to the broader aspects of the invention, polyether polyols
are produced by oxyalkylating a polyhydric initiator at lower temperatures
with an alkylene oxide in the presence of an effective amount of an aqueous
ammonia solution. The nitrogen conta;n;ng moiety also undergoes oxyaIkyla-
tion during the process such that the final polyether polyol contains admixed
therewith various alkoxyalkanol amines which contain reactive hydroxyl groups
and act as a mild catalyst for polyolixocyanate reactions.
According to a preferred embodiment, polyether polyols having low
hydroxyl numbers and low viscosities are prepared by forming an aqueous
initiator-ammonia mixture
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1065314
which is heated to temperatures of about 40C. The heated
mixture is intimately contacted with an alkylene oxide
selected from ethylene oxide, and propylene oxide and
mixtures thereof at temperatures of from about 40C to 120C
to produce the polyether polyol composition.
DETAILED DESCRIPTION OF THE PREFERRED E~BODIMENT
Polyether polyol compositions having hydroxyl
numbers from about 400 to about 650 with viscosities from
about 4,000 to 20,000 centipoise are produced in accordance
with a preferred embodiment by initially admixing sufficient
water with a solid sucrose initiator to form a homogeneous
aqueous solution containing from about a 50~ to about 75~ by
weight sucrose. The aqueous solution thus formed is then
heated to from akout 30C to about 40C in a suitable reaction
vessel such as a sealable reaction kettle fitted with agita-
tion apparatus or the like. The temperature of the solution
is maintained while the solution is agitated in an inert
atmosphere, e.g. nitrogen. Ammonia gas is then pressured
into the kettle at autogenous pressure until an a~ueous
ammonia-sucrose solution is obtained containing from about
10 to 100 parts by weight sucrose to 1 part by weight ammonia.
While agitation is contined, ethylene oxide is slowly
pressured into the reaction kettle at autogenous pressures.
The temperature of the exothermic reaction mixture is
regulated between about 50 and 65C during ethylene oxide
addition by the removal of heat using suitable means such as
for example a water cooled condenser or the like. The
ethylene oxide addition is continued until from about 2 to 12
moles of ethylene oxide is added per mole of sucrose. The
ethylene oxide is allowed to digest until a substantially
constant pres~ure is attained.
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The excess oxiAe is vented and excess water by,
for example, vacuum stripping to yield a reaction mixture
having from about 8% to 12~ by weight water.
The reaction mixture is then heated by suitable
means to temperatures of from about 100C to about 115C.
Propylene oxide is then slowly pressured into the reaction
kettle at autogenous pressure in amounts from 8 moles to 20
moles per mole of sucrose. The propylene oxide is allowed
to digest until a substantially constant pressure is attained
to yield a polyether polyol in accordance with the instant
invention.
If desired, formed glycols and additional water
can then be removed by, for example, steam stripping followed
by vacuum stripping accomplished by methods well known in the
art.
In the broadest sense, the polyether polyols of
the instan~ invention are the oxyalkylation product of an
alkylene oxide and an initiator having from about 2 to 8
hydroxyl moieties per molecule. The initiators useful in
the practice on the invention can be characterized generally
as aliphatic polyhydric nonreducing compounds. These
initiators are well known in the art, many being described
in U.S. Patent 3,535,307. A preferred class of initiator~
are those aliphatic nonreducing polyhydric compounds having
from 3 to 8 hydroxyl groups. The preferred initiators are
sucrose, sorbitol, ~ -methyl glucoside, hydroxypropyl gluco-
side, pentaerythritol, trimethylolpropane, and glycerine.
The most preferred is sucro~e because of availability.
The oxyalkylating agents useful in the practice
of the instant invention may be generally characterized as
the alkylene oxides. A preferred group of alkylene oxides
1()653~
are those having from about 2 to about 4 carbon atoms and
more preferably the 1,2-epoxides having 2 to 3 carbon atoms,
i.e. ethylene oxide and propylene oxide.
The oxyalkylated product, i.e. the polyether
polyols of the instant invention, are achieved by the utili-
zation of specific alkylene oxides or mixtures thereof in
various quantities. While the hydroxyl number and viscosi-
ties of the final polyol products are determined by various
factors such as temperature ancl the amount of ammonia pre-
sent, to a large extent the characteristics of the final
polyol are determined by the oxyalkylating agents, their
manner of addition to the reaction meaia, and the quantities
used. The alkylene oxide addition is therefore somewhat
empirical and depends upon factors such as the product
desired, the alkylene oxides used, the method of addition,
the order of addition and the temperatures at which the
alkylene oxides are added. For example, the alkylene oxide
rea~ent can be added to the reaction mixture in either a
heteric or a blocked manner or a combination thereof.
In order to achieve the most desired polyols of
the instant invention, it is preferred that a blocked addi-
tion be utilized wherein ethylene oxide is first added to
the reaction mixture and then propylene oxide is added.
Various addition methods yield products of the desired
viscosity range with desirable hydroxyl numbers. For ex-
ample, heteric-type addition can be used wherein a mixture
of ethylene oxide and propylene oxide is added. Further,
the relative concentrations of ethylene oxide and propylene
oxide may be varied in the mixture as the reaction progresses.
For example, an ethylene oxide rich mixture may be initially
metered into the reaction mixture. As the addition pro-
10~53~4
gresses, the relative concentration of propylene oxide may
be increased. This can be accomplished ~ith, for example,
a valved mixing nozzle which is progressively regulated.
According to the invention, the reaction mixture
contains aqueous ammonia which may be supplied by any ammonia
releasing or ammonium hydroxide forming sllhstance which is
nondeleterious to the reaction. The concentration of ammonia
present in the aqueous ammonia-initiator solution is pre-
ferably from about 1:10 to 1:100 parts by weight of ammonia
to initiator and more preferably 1:10 to 1:3Q. All the
ammonia present in aqueous solution is believed to be present
as the hydroxide. Preferably ammonia gas is used, being
brought into intimate contact with an aqueous initiator solu-
tion. Ammonium hydroxide can also be employed either alone
or in combination with the ammonia gas. ~hen ammonium
hydroxide is used, preferably a 29% ammonia by weight
aqueous solution is employed. It will be understood that the
initial water added to the coinitiator can be reduced pro-
portionally to allow for the water added when aqueous
ammonium hydroxide is employed.
The exact amount of water used in forming the
initial reaction mixture is not critical. A sufficient
amount of water is necessary to dissolve the solid initiator
and expedite the reaction. Since the majority of the water
is removed from polyether polyols used in nonaqueous urethane
systems, polyols prepared for use in suc~ systems advan-
tageously contain only small amounts of water. Excess
water occurring in the final polyether polyol products pro-
duced may be removed by any suitable method known in the art
such as vacuum stripping.
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According to the process of the instant invention,
an initial reaction mixture is formed wherein an initiator is
admixed with water and an ammonia releasinq substance or
ammonium hydroxide. Preferably, the initiator is first
admixed with water to form a homogeneous solution to which
ammonia is added. The most preferred aqueous initiator solu-
tions are those obtained in commerce which are already in
liquid form. These solutions facilitate pumping of the
initiator into the reaction vessel without the need for hand-
ling solid initiator such as sucrose or the like. Anhydrousammonia is contacted directly with the aqueous initiator solu-
tion. The aqueous initiator-ammonia solutions are thus pre-
pared by pressuring ammonia gas into the initiator solution
at autogenous pressures preferably in the presence of an inert
atmosphere until a desired concentration is obtained.
Preferably, the aqueous sucrose solution is ini-
tially preheated to temperatures of from about 30C to 40C
to facilitate the addition of the ammonia and to further
dissolve the initiator when a solid initiator is used. The
preheating step is desirable in that it decreases the amount
of water required to form a sub8tantially single phase
aqueous ammonia-initiator mixture and helps insure a homo-
geneous reaction mixture. Durinq this preheating, an inert
atmosphere is maintained within the reaction kettle. Pre-
ferably this is accomplished by the introduction of anhydrous
nitrogen; however, any inert gas commonly used for such
purposes may be utilized. The inert atmosphere is not
critical and is employed to prevent formation of color
forming impurities which detract from the appeal of the
urethane foam ultimately produced from the polyether polyols
formed.
1065314
The oxyalkylation can be accomplished immediately
upon formation of the initial reaction mixture. The alkylene
oxide is pressured in the reaction kettle and allowed to
come in intimate contact with the reaction mixture. Gen-
erally, oxyalkylation is an exothermic reaction. Depending
on the alkylene oxide used, the heat of reaction must be
dissipated from the reaction mixture or the rate of addition
regulated to maintain the reaction mixture temperature below
about 150C. Temperatures in excess of 150C facilitate
unwanted side reactions which result in color forming
impurities. In order to initiate the oxyalkylation reaction,
the reaction mixture can be initially heated to a desirable
temperature.
When block addition of more than one alkylene oxide
is required, it has been found advantageous to carry out the
oxyalkylation step in stages. Thus, reaction temperatures
may be more effectively controlled to facilitate formation
of particular products, and the water content of the reaction
mixture can be regulated at the termination of each stage.
As was mentioned hereinbefore, unexpectedly the
instant process does not result in extensive diol formation,
even though water is used as a solvent. The reason for this
is not clearly understood but is believed to be associated
with the weak basisity of the nitrogen containing moiety.
As water i~ present in the reaction mixture, however, it
will react to some extent with the oxides to produce glycols
thus increasing the hydroxyl number of the final product.
Therefore, by utilizing blocked addition techni~ues, excess
water can be removed prior to addition of alkylene oxides
requiring strenuous reaction conditions, such as for example
high temperatures.
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1065314
When the ethylene oxide and propylene oxide are
added in a blocked manner, preferably ethylene oxide is
added in amounts from about 2 moles to about 12 moles per
mole of initiator and more preferably 3 moles to about 5
moles per mole of initiator. The amounts of propylene oxide
which can be utilized are pefera~1y from about 8 moles to
about 20 moles per mole of initiator, and more preferably
from about 12 moles to about 16 moles per mole of initiator.
Preferably the ethylene oxide is added at lower temperatures
of about 50 to 65C, whereas the propylene oxide is added
at slightly higher temperatures of from about 105 to 115C.
Additionally, to insure inhibition of diol formation,
excess water is preferably removed at the termination of
the ethylene oxide addition. Sufficient water is removed
such that the reaction mixture contains from about 6% to
about 12% water by weight and more preferably 10% water by
weight. Surprisingly, it has been found that lowering the
water concentration below about 6% does not decrease sub-
stantially the small amount of glycol formed, but does
materially impede the completion of the alkylene oxide
addition.
After each addition of alkylene oxide, preferably
sufficient time is allowed to completely digest and react
the added reagent. Upon completion of all alkylene oxide
additions, the reaction vessel is vented. Excess water and/
or glycol then may be removed by vacuum stripping or steam
stripping the reaction product. The need for water and/or
glycol removal at various stages during the production of
the polyether polyols will depend upon the final product
desired. According to a preferred embodiment wherein the
ethylene oxide and propylene oxide are added in blocks,
10~5314
regulation of the reaction mixture water content after the
ethylene oxide addition may render subsequent steam strip-
ping to effect glycol removal unnecessary.
During the instant process, the nitrogen contain-
ing moiety, which is predominately ammonium hydroxide under-
goes oxyalkylation. The oxyalkylated nitrogen moiety, which
can best be described as an alkoxyalkanolamine, is present
in the final product. Thus, the polyether polyols of the
instant invention contain, admlxea therewith, various
alkoxyalkanol amines which need not be removed prior to the
polyol-isocyanate reaction. These amine compounds have been
shown to contain hydroxyl moieties which undergo reaction
to become an integral part of the polyurethane polymeric
network. Additionally, these amine compounds act as a mild
catalyst in the isocyanate reaction yielding highly desir-
able foams, but not interfering with the formulation of
reactants. Specifically, it has been discovered that the
amount of externally added catalyst normally required in
foam formulation need not be varied when using the polyether
polyols of the instant invention.
The equipment required for carrying out the process
of the instant invention is well known in the art. The
process can be carried out in a single standard gas-liquid
phase reaction kettle preferably fitted with a stirring
apparatus and a means for heating the reactants from tempera-
tures of about 30C to about 120C. Additionally, the
reaction kettle need only maintain pressure integrity at
pressures of from 1 to 6 atmospheres.
In accordance with another aspect of the invention,
it has been unexpectedly found that the viscosity of the
final polyether polyol produced in accordance with the
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1065314
invention can be varied within relative limits by varying
the amount of ammonia originally present in the aqueous
initiator-ammonia admixture. It will be realized that
generally the viscosity increases as the hydroxyl number
increases and this is generally true of the polyether polyols
produced in accordance with the instant invention. However,
it has been found that a relatively less viscous product
may be formed by adding relatively more ammonia in the
initial step of the process. For example, it has been
shown that viscosities in the range from about 1,000 to
about 8,000 centipoise can be obtained with polyether polyols
produced in accordance with the invention having hydroxyl
numbers from about 450 to about 600 by adding from about 1
to about 5 weight % excess ammon;a based upon the weight of
ammonia initially present in the aqueous initiator-ammonia
solution. Generally, the amount of excess ammonia that can
be added is that amount which will nondeleteriously affect
the urethane foam produced from the polyether polyol pro-
duced in accordance with the instant invention.
In accordance with another aspect of the instant
invention, a polyether polyol which is suitable for blending
may be produced. Blending as used herein is physically
admixing one or more polyether polyols having for example
different hydroxyl numbers and viscosities to produce a
polyether polyol admixture having a hydroxyl number and a
viscosity within a desirable range for a specific application.
Specifically, by forming an aqueous ammonia-initiator solu-
tion containing an excess of ammonia polyols having relatively
lower viscosities can be produced. Further, by oontacting
the aqueous ammonia-initiator containing excess ammonia with
relatively larger molar amounts of ethylene oxide at lower
10~;531~
temperatures and relatively smaller amounts of propylene
oxide at higher temperatures, polyether polyols having
lower hydroxyl numbers. Depending on the viscosities and
hydroxyl numbers desired, the polyether polyols produced in
accordance with the invention can then be blended with
otherwise nonusable polyols such as polyether polyols having
very high viscosities to yield polyether polyol blends
which are urethane system compatible.
Unexpectedly, it has been found that in accord-
ance with this aspect of the invention, the presence of the
alkoxyalkanol amines greatly increases the blendability of
the polyether polyols produced. Thus, not only may the
hydroxyl number and viscosity of an undesirable polyol be
reduced by blending with polyols of the instant invention,
but the blend is easily obtained with a minimum of physical
mixing.
The following examples are presented for illus-
trative purposes only and are not meant by way of limitation.
Example I
In this example a polyether polyol having viscosi-
ties and hydroxyl number~ which are compatible with urethane
systems was produced. Initially a lS-gallon reaction kettle
fitted with agitation equipment was charged with 4.0 lbs. of
water and 20.2 lbs. (0.059 lb. mole) granular sucrose. An
anhydrous nitrogen atmosphere was then introduced and the
admixture stirred to obtain a homogeneous solution. Agitation
was continued as 1.13 lbs. (0.0666 lb. mole) of ammonia was
pressured into the kettle. The resulting homogeneous mixture
was heated to about 40C with agitation and 9.0 lbs. (0.204
lb. mole) of ethylene oxide was pressured into the kettle at
a rate so as to maintain the exothermic reaction mixture
~0653~
below 60C. The reaction mixture was then digested at
50-60C to a constant pressure.
The resulting reaction mixture was heated with
agitation to temperatures of about 110 to 115C and 56.0
lbs. (0.965 lb. mole) propylene oxide was pressured into
the kettle at a rate such that the entire amount of propylene
oxide was added over a three hour period. With continued
agitation, the propylene oxide was digested to a constant
pressure. The excess oxides were then vented and excess
water removed by vacuum stripping. The resulting reaction
product mixture was further steam stripped to remove glycols
followed by vacuum stripping to remove still further water.
The resultant dark red viscous liquid weighed 77.5 lbs. and
analyzed as follows: hydroxyl number, 522; viscosity (25C,
Brookfield), 17,750; amine (meq/g), .82; and H20 (~ by
weight) .06.
Example II
To a 15-gallon kettle fitted with a stirring device
was added 30.0 lbs. (0.059 lb. mole) of 67.2% by weight
sucrose solution, which was stirred at 25-30C under nitrogen
atmosphere while 1.13 lbs. (0.066 lb. mole) anhydrous ammonia
was pressured into the kettle. The resulting homogeneous
mixture was stirred and heated to 40-45C while 9.0 lbs.
(0.204 lb. mole) of ethylene oxide was added at a rate so a~
to maintain the exothermic reaction below 60C. Then, 3.0
lbs. (0.052 lb. mole) of propylene oxide wa~ added. The
resulting mixture was finally heated to 75-80C and digested
for 30 minutes.
The aqueous reaction product mixture was stripped
with partial vacuum down to 80 mm Hg/80C reducing the water
concentration to 10.5%. The stripped mixture was then heated
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106S3~4
to 115C and 53 lbs. (0.915 lb. mole) propylene oxide was
added at a constant rate over a two-hour period. After a
one-hour digestion period at 115C, the temperature was
raised to 125-130C and the mixture steam-stripped for two
hours and finally vacuum stripped at 5 mm Hg/125C. The
product obtained was a clear, red, viscous liquid. The
product analyzed as follows: hydroxyl no., 533; viscosity
(25C, Brookfield), 18,200 cps; H20 (% by weight), 0.07;
color (Gardner), 10; and amine (meq/g), .86.
Example III
In this example, ethylene oxide and propylene
oxide were added by heteric addition in accordance with the
invention. A 15-gallon reaction kettle fitted with
agitation equipment was charged with 22.0 lbs. (0.0427 lb.
mole) of a 67% by weight aqueous sucrose solution and
stirred under a nitrogen atmosphere while 0.85 lbs.
(0.050 lb. mole) of anhydrous ammonia was pressured into
the kettle.
The resulting homogeneous mixture was then heated
to 45-50C with agitation and 10.4 lbs. (0.195 lb. mole) of
a heteric mixture containing lS lbs. (33% by weight) ethylene
oxide and 30 lbs. (67% by weight~ propylene oxide was
pressured into the kettle at a rate such as to maintain the
exothermic reaction mixture below about 60C. Upon com-
pletion of the addition, the agitated mixture was heated to
65-80C and digested for about 30 mins. The digested solu-
tion was stripped at 80 mm Hg/80C to remove water. The
percent by weight water remaining in the solution was about
10.2. The stripped solution was then heated with agitation
to a temperature of about 110-115C and 34.6 lbs., i.e. the
remainder of the heteric propylene oxide-ethylene oxide
10~
admixture, was pressured into the kettle. The temperature
was maintained with agitation for about 2 hours to digest
the reactants.
The kettle was vented and the mixture was stripped
at 5 mm Hg/110-115C. The resultant product consisted of
58.8 lbs. of a clear, light, reddish-brown liquid which
analyzed as follows: hydroxyl number, 545; viscosity (25C,
Brookfield), 6,900; H2O (% by weight), .10; color (Gardner),
10: and amine (meq/g), .90.
Examples IV-VI
These examples demonstrate that varying the water
content of the reaction mixture prior to the block addition
of propylene oxide produces highly desirable polyols without
the necessity of steam stripping. All three examples were
prepared in a ~ubstantially similar manner wherein a 15-gallon
reaction kettle fitted with agitation equipment was charged
with 22.0 lbs. (0.0427 lb. mole) of a 67% by weight aqueous
sucrose solution and stirred under a nitrogen atmosphere at
40-45C. Then 0.85 lbs. (0.050 lb. mole) of ammonia was
pressured into the kettle.
After the ammonia addition, 8.60 lbs. (0.195 lb.
mole) of ethylene oxide was added over a l-hour period with
the exothermic reaction mixture temperature being maintained
below about 57C. The resultant reaction mixture was digested
for 1 hour at about 75C and the kettle was vented. The
reaction was then vacuum stripped at 50-100 mm Hg/75C to
give a water content in the reaction mixture as shown in
Table I below for each of the three examples.
The stripped mixture was then heated to 110C and
38.0 lbs. (0.655 lb. mole) of propylene oxide added over a
1-1/2 hour period. After digesting for 2 hours, the kettle
1065~14
was vented. The resulting mixture was vacuum stripped at
5 mm Hg/105C to 110C. The various properties of the three
products obtained are shown in Table I.
TABLE I
4 S 6
Approx. H20 by weight %
when propylene oxide
addition started 10.0 8.2 6.8
Approx. lbs. water reacted 1.06 1.31 1.0
Products
Hydroxyl number 517 525 530
Viscosity (25C,
Brookfield) 11,000 lO,OC08,500
H20 (~ by weight final)0.07 0.030.04
Amine (meq/g) .79 .78.81
Color (Gardner) 12 11 11
pH 10.1 10.210.7
Examples ~ VIII
In these examples, the effect of adding excess
ammonia in accordance with the invention is shown. Both
products were prepared in a similar manner using a 5-gallon
reaction kettle charged ^~ith initiator-water solutions and
the process was conducted subctantially as described in
Examples IV-VI using reactants in quantities and under
reaction conditions as shown in Table II.
-18-
10~ 4
TABLE II
Reactants 7 8
Initiator (tetrol)
~ -methyl glucoside (lbs.) 9.7
Pentaerythritol (lbs.) 6.8
Water (lbs.) 5.0 5.0
Ammonia added at about 50C .50 .50
Ratio of ammonia to initiator
(by weight) 1:19.5 1:13.6
Ethylene oxide added at
50-60C (lbs.) 5.0 5.0
Digestion 50-60C (hrs.)
Vacuum stripped at 75-80C (hrs) 3 3
Propylene oxide at 110 (lbs.)22.5 18.5
Digestion 110C (hrs) 2 2
Stripped at 5 mm Hg/110C ~hrs)
Product
Hydroxyl number 493 604
Viscosity 4,100 1,400
H20 (% by weight) 0.02 0.10
Amine (meq/g) .74 .93
Color (Gardner) 12 12
pH 10.3 11.5
Examples IX-X
In these examples, polyether polyols were prepared
substantially by the method of Examples VII and VIII using a
hexol and a pentol initiator, respectively. In Example IX,
sorbitol was utilized as an initiator, while in Example X
hydroxypropyl glucoside was used. The quantities of reactants
used and the characteristics of the products obtained in each
of these examples is shown in Table III.
1065314
- TABLE III
9 10
Reactants
Initiator (lbs.)
70% aqueous sorbitol (lbs.) 13.0
80% hydroxypropyl glucoside (lbs.) 9.0
Anhydrous ammonia (lbs.) 0.50.45
Ethylene oxide at 50-60C 5.04.5
Propylene oxide at 110C 26.017.5
Product
Hydroxyl no. 557 522
Viscosity (25C, Brookfield) 5,7004,700
H20 (~ weight final) 0.0~0.05
Amine (meq/g .66.93
Color (Gardner) 13 12
pH 10.111.9
Table IV shows a side by side comparison of the
polyather polyols prepared with different initiators. The
amount of reactants are based on a by weight ratio using the
amount of ammonia as unity. Columns A, B, C, D, and E of
Table IV represent the data of Examples VI, IX, X, VII, and
VIII, respectively.
-20-
~;5314
TABLE IV
A B C D E
Reactants
(Ratio by weight of
ammonia present)
Ammonia 1.0 1.0 1.0 1.0 1.0
Initiator
Sucrose (octol) 17.2
Sorbitol (hexol) 18.2
10Hydroxypropyl
glucoside (pentol) 16.0
-methyl glucoside
~tetrol) 19.5
Pentaerythritol
(tetrol) 13.6
Ethylene oxide lQ.l 10.0 10.0 10.0 lO.C
Propylene oxide 45.0 52.0 39.0 45.0 37.0
Analysi~
Viscosity (25C,
20Brookfield) 8,500 5,7004,700 4,100 1,400
Hydroxyl no. 530 557 522 493 604
Examples XI-XII
In these examples, polyol blends were prepared in
accordance with the invention by physically admixing a
Polyol A produced in accordance with the instant invention
and a commercially available Polyol B of high viscosity.
The analysis of the constituent polyols and the resulting
blend is shown in Table V.
1065314
TABLE V
11 12
Polyol A (g) 4001) 2503)
Hydroxyl no. 493 545
Viscosity (25C, Brookfield) cps 4,100 6,900
Polyol B (g) 4002) 1504)
Hydroxyl no. 574 631
Viscosity (25C, Brookfield) cps 2S0,000 176,000
Blend (g) 800 400
Hydroxyl no. 539 580
Viscosity (25C, Brookfield) cps 23,000 20,000
1) Polyether polyol produced in Example VII f~
2) Polyether polyol sold under the name "THANOL R-850" by
Jefferson Chemical Co., Inc., Box 53300, Houston, TX 77052
3) Polyether polyol produced in Example III ~
4) A polyol intermediate or condensate of "THANOL R-650-X"
sold by Jefferson Chemical Co., Inc. Box 53300,
Houston, TX 77052
Examples XIII-XVIII
In these examples, rigid polyurethane foams were
produced from the polyether polyols produced in Examples VI,
IX, X, VII, VIII, and XI. The polyurethane foams in each of
these examples were produced in a substantially identical
manner with amounts of reactants in parts by weight as set
forth in Table VI. In each formulation 0.5 parts by weight
of the reactants was a silicon oil emulsifying surfactant
sold under the trade name "DC 193" by The Dow Chemical Co.,
Midland, Michigan 48640, 0.5 parts by weight was a tri-
ethylenediamine (TEDA) - dipropylene glycol catalyst solution
containing about 33% by weight TEDA sold under the trade name
B "DABCO~33-LV" by Air Products and Chemical, Inc., Houdry
Division, 1339 Chestnut St., Philadelphia, Pa. 19107 and 13
parts by weight was trichloromonofluoromethane used as a
blowing agent. In each example the reactants were admixed
(tracle ~a r k)
-22-
10~
and poured into molds 7"x14"x8" and allowed to foam. The
cured foam was tested to determine its physical properties.
The results of these tests are set forth in Table VI.
TABLE VI
13 14 15 16 17
Formulation
(pbw) 1) 2) 3) 4) 5) 6)
Polyol 37.1 36.0 37.2 38.6 34.2 36.6
7)
Isocyanate 48.9 50.0 48.8 47.4 51.8 49.4
Cream time, sec 36 33 27 32 27 37
Tack free time,
sec 117 130 90 120 90 135
Rise time, sec 150 185 120 180 120 180
Physical
Properties
Density
(lbs./cu.ft.) 2.21 2.04 2.03 2.06 1.90 2.10
Friability8) None Very Yes Yes Slight Very
(initial) Slight Slight
Friability 9)
(internal) 5.75 8.3 7.5 1.2 4.6 17.8
Heat distortion
(C) 182 181 152 155 149 181
K-factor (~tu,
in./sq.f~
hr., F) ~ 0.118 0.116 0.119 O.I09 0.117 0.122
% closed cells
(based on
total cells) 93.6 93.0 94.6 95.4 92.5 91.4
Dimensional
stability 11)
(% volume
Increase) +4 +1 +4 +6 +3 +6
1) Polyether polyol of Example VI
2) Polyether polyol of Example IX
3) Polyether polyol of Example X
4) Polyether polyol of Example VII
5) Polyether polyol of Example VIII
6) Polyether polyol blend of Example XI
7) Methylene bridged polyaryl isocyanate (f- 2.7)
8) Performed 10 mins. after pouring; classification: none,
very slight, slight, yes, very
9) % wt. loss after 10 mins. of tumbling
10) Measure of heat permeability for a given thickness
11) 100~ realtive hum~dity; 158F; one week
-23-
~O~S314
While the invention has been explained in relation
to its preferred embodiment, it is to be understood that
various modifications thereof will become apparent to those
skilled in the art upon reading the specification and is
intended to cover such modifications as fall within the
scope of the appended claims.
