Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~Lo60~48 ::
; .,-..
The prese~t invention relates to high-temperature
resistant isocyanurate foams. More particularly, the inven~
tion relates to the preparatlon of isocyanurate foams having
~ exceptional high temperature properties by the reaction of
a polymeric isocya~ate and polyols in the presence of a blow-
ing agent and a trimerization catalyst.
The preparation of isocyanurate foams as well as
the use of these foams for insulation is well known in the
art. One of the requirements in the insulation of storage
tanks for hot oil, tar and other chemicals is that the
foams retain their properties at these elevated tempera~
.
tures. Another requirement of isocyanurate foams used for ~
~insulation of these high-temperature storage tanks is that ~ '
the foam system must be sprayable. The present invention
is directed to the preparation of isocyanurate foams
possessing exceptional high-temperature properties from
sprayable foam systems. ~ ;
-2-
: ..
~ . . . .
106014~
The present invention relates to high-temperature
resistant isocyanurate foams prepared by the reaction of
certain polymeric polyisocyanates and polyoxyethylene `
polyols in the presence of a blowing agent and a 1,3,5-
tris(N,N-dialkylaminoalkyl)-s-hexahydrotriazine trimeriza~
tion catalyst. Specifically, the invention relates to ;`
isocyanurate foams prepared by the reaction of~
(a) a polyaryl polyalkylene polyisocyanate
having a functionality of from 2.2 to 3.5 :in the presence of
(b) from 5 parts to 40 parts by weight of a :
. polyoxyethylene polyol havi~ a hydroxyl
number of from 100 to 900 and an ethylene
oxide content of from 50~ to 95~ by
L5 weight; .
~c) from L0 parts to 40 parts by weight of
a fluorocarbon blowing agent, and ~.
(d) from 1 part to 6 parts of a 1,3,5,-tris- :
(N,N-dialkylaminoalkyl)-s-hexahydrotriazine
.: ~,
'0 trimerization catalyst or the alkylene oxide ; :
and water adducts thereof, said parts ~:
.~ . ..
being based on 100 paxts by weight of
polyisocyanate.
'." ~ ,'::
,: :` ",-:
'`', ~.
-3- .
- , ~ . .
; ~06~148
As stated, there are four essential ingredients
employed in the isocyanurate foams of the present inven-
tion. One ingredient is a polyaryl polyalkylene polyiso-
cyanate. Various polyaryl polyalkylene polyiso-
cyanate and preferably a polyphenyl methylene polyiso-
cyanate which contains both di- and triisocyanates may be
used. Mixtures of isocyanates such as those disclosed in
U. S. Patent No. 2,683,730, British Patent No. 874,430,
and Canadian Patent No. 665,495 can be used. It is also
possible to use mixtures of polyphenyl polymethylene poly-
isocyanates which are outside the scope of these patents.
A particularly desirable one has a viscosity of from
150 to 250 cps. at 25C., and an isocyanate content
of at least 31% and has from 42~ to 48% of
its isocyanate content present as a monomeric diphenyl
methane diisocyanate. It is preferred to prepare the
polyaryl polyalkylene polyisocyanate by the reaction between
aniline and formaldehyde in such proportions of these two
reactants that an amine product is obtained which has
from 40% to 60% of diphenylmethane diamine and the balance
higher polyamines so that when the resulting mixture
of diphenylmethane diamine and higher polyphenyl poly-
methylene polyamines is phosgenated, the product
contain~ from 40% to 60% diphenyl methane diisocyanate,
-4-
1 0 60 ~ 4
20~ to 30~ triisocyanates, 8~ to 17~ tetxaisocyanate and
5% to 30~ penta- or higher polyisocyanates. Thus, in : :
accordance with a preferred method of preparing the poly- .
phenyl polymethylene polyisocyanates, one begins with the
aniline-formaldehyde reaction wherein the aniline and acid
catalyst are first mixed and reacted together and then the ~ :
resulting mixture of the acid salt, e.g. aniline hydro- .
chloride, and aniline are reacted with formaldehyde to
produce the mixture of diphenyl methane diamine and high `~:
polyamines. Then the initial amine product is neutralized. ~.
with approximately a stoichiometric amount of a base or
even a very slight excess of a base such as sodium
hydroxide, potassium hydroxide or the like and then the
amines to be phosgenated are separated from the salt formed
L5 by decantation and distillation to remove the water and
the salt. This mixture of amines may then be phosgenated
to preapre a mixture of organic polyisocyanates by a suitable ~ p~
phosgenation reaction such as those disclosed, for : ::
example, in U. S. Patents Nos. 2,683,160; 2,683,730;
!0 2,875,226. However, in order to get the desired
percentage of diisocyanates, the desired viscosity "~
and the desired isocyanate content,it is preferred to ~ .
carry out the reaction in two stages: first, at a tempera~
ture of from -20C. to 80C. and then ln a stage at ~ ~
-~ '
`
, :.
~ 06~148
a temperature of from 90C to 200C. Thus, the
polyphenyl polymethylene polyisocyanates are preferably
prepared b~ reacting phosgene with the aforementioned mix-
ture of amines in two stages at such a temperature that the
exothermic reaction occurriny wh~n these two components
are combined is initially not substantially above 90C.
to form a carbamyl chloride-amine hydrochloride slurry
which is then reacted with further phosgene at a tempera-
ture above 90C. but below 20C. to prepare the
mixture of polyphenyl polymethylene polyisocyanates referred
to above. It is preferred to use an inert organic
solvent in the phosgenation of the amlne. For thi~ pur-
pose, both the amine and the phosgene are premixed with the
organic solvent and then reacted in a solution in two
stages as set forth above to prepare the organic polyiso-
cyanateD It is preferred to use some type of high-speed
mixer for contacting the phosgene solution and amine
solution in the preparation of the initial carbamyl
chloride-amine hydrochloride slurry. A suitable high-speed
mixer is contemplated such as, for example, turbo-mixers,
colloid mills, pumps including centrifugal pumps,
which contain structural elements which rotate at high
speeds and thus insure intimate contact between the amine
and the phosgene within a relatively short period of time.
~a~6~14~3 :
Preferably, the high-speed mixer should be one whiah
roatates at a speed of 100 rpm. or more.
A suitable organic solvent which i9 inert to
the amine, to the resulting isocyanate, and to phosgene
may be used. Thus, solvents are, for example,
those which have the formula:
1 ~ 4
wherein R is the same or different and is lower alkyl,
hydrogen, halogen, nitro, aryloxy, alkoxy as well as hydro-
carbons, ethers, esters. A suitable halogenmay be used such as, chlorine, bromine, iodine,
fluorine. A suitable aryloxy radical may be
used such as, for example, phenoxy, cresoxy, ethyl-
phenoxy. A suitable alkoxy radical may be used
such as, for example, ethoxy, methoxy, propoxy,
butoxy~ Furthermore, mixtures of hydrocarbons such
as kerosene may be used. Examples of specific compounds
are benzene, toluene, xylene, chlorobenzene, o-dichloro- ;
benzene, nitrobenzene, cyclohexane, durene, o-, m-,
p-cymenes, dodecyl naphthylene ethyl acetate, diphenyl.
It has also been found preferable to use a low
amount of acid in the condensation of aniline with form-
aldehyde in order to achieve a mixture of amines which
~06~
will on phosgenation, yield the proper amount of diiso-
cyanate, total isocyanate and viscosity as set forth
above. This amount is preferably from 1% to 15%
of the acid required to react with all of the
amine in the reaction mixture.
Included within the term "polyarylpolyalkylene
polyisocyanates" as used herein are isocyanate-terminated
prepolymers prepared from the above polyisocyanates. These
prepolymers are prepared by reacting a stoichiometric
excess of the above polyisocyanates with any organio com-
pound having at least two reactive hydrogen compounds,
preferably polyether polyols.
The second ingredient employed in the preparation
of the isocyanurate foams of the present invention is a
polyoxyethylene polyol. These polyols have a hydroxyl
number of from lO0 to 900 and an ethylene oxi~e content of
from 50% to 95~ by weight. The polyols are generally
prepared by the reaction of ethylene oxide with a polyhydric
alcohol having from 2 to 8 carbon atoms and from 2 to 6
hydroxyl groups, or they may be prepared by the reaction of
ethylene oxide with the propylene oxide adducts of a poly-
hydric alcohol. Representative.polyhydric alcohols include
both aliphatic and aromatic alcohols such as ethylene
glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-
,
- . . , - . - ,: , :
., ,: , , : .
~L06~
butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol,
1,5-pentane diol, 1,4-pentane diol, 1,3-pentane diol,
1,6-hexane diol, 1,7-heptane diol, glycerol, 1~1,1-
trimethylolpropane, l,l,l-trimethylolethane, hexane-l,Z,6- ~,
triol, ~-methyl glucoside, pentaerythritol, sucrose and
sorbitol D Also included within the term "polyhydric
alcohole' are compounds derived from phenol such as 2,2-
di(4 hydroxyphenyl)propane, commonly known as Bisphenol A.
The following polyoxyethylene polyols are
10 preferred polyols of use in the subject invention: -
Polyol A - a polyol having a hydroxyl number
of 230 prepared by the reaction of
ethylene oxide with trimèthylol,
propane (oxyethylene content of
82~ by weight).
Polyol B - a polyol having a hydroxyl number
of 120 prepared by the reaction
of ethylene oxide with trimethylol-
propane (oxyethylene content of 90%
by weight).
Polyol C - polyol ha'ving a hydroxyl number of
561 prepared by the reaction of
ethylene oxide with trimethylol-
propane (oxyethylene content of
approximately 55% by weight).
g_
.
~L06~L4~
Generally from 5 parts to 40 part~ of polyol based
on 100 parts of polyisocyanate will be employed in the
present inventionO
The third ingredient employed in the preparation
of the isocyanurate foams of the present invention is a
1,3,5-tris(N,N-dialkylaminoalkyl)-s-hexahydrotriazine or
the alkylene oxide and water adducts thereof. It has been
found that other conventional isocyanurate trimeriz-ation
catalysts such as 2,4,6-tri(dimethylaminomethyl)phenol ara
not operable in the present invention. 1,3,5-Tris(N,N-
dialkylaminoalkyl)-s-hexahydrotriazines are generally
prepared by reacting aquimolar amounts of a dia~kylamino-
alkylamine and a 37% aqueous solution of formaldehyde
(formalin) at a temperature ranging from about OC. to
20C., and at atmospheric pressure. More particularly, the
amine and the formaldehyde are mixed together with gentle
stirring at about OC. Thereafter, and with continuous
gentle stirring the resulting mixture is allowed to heat
up to room temperature. The hexahydrotriazine compound is
then recovered by first saIting out the hexahydrotriazine
from the reaction mixture with a strong base, such as
potassium hydroxide and then purifying by distillation.
These hexahydrotriazine compound~ and their methods of
preparation are more particularly described by Nicolas et
--10--
.~ :
.; . . :
~06~
al, Journal of Cellular Plastics, 1 (1), 85 (1965), and
Graymore, Journal of the Chemical Soci~, 1493 (1931).
Representative of the 1,3,5-tris(N,N-dialkyl-
aminoalkyl)-s-hexahydrotriazines useful herein include, for
example, 1,3,5-tris~N,N-dimethyl-2 aminoet.hyl)-s-hexahydro-
triazine, 1,3,5-tris(N,N-dimethyl-2-aminop.ropyl)-s-hexa-
hydrotriazine; 1,3,5-tris(N,N-diethyl-2-aminoethyl)-s-
hexahydrotriazine; 1,3,5-tris-(N,N-dipropyl-2-aminoethyl)-s- .
hexahydrotriazine. The preferred compound is 1~3,5-tris-
(N,N-dimethyl-3-aminopropyl)-s-hexahydrotriazine which can
also be designated as 1,3,5-tris(3-dimethylaminopropyl)--s-
hexahydrotriazine.
other preferred isocyanate trimerization catalysts,
as noted, are the alkylene oxide and water adducts of the
hereinbeore described 1,3,5-tris(N,N-dialkylaminoalkyl)-s-
hexahydrotriazines. The alkylene oxides which may be used
to prepare the adducts are, preferably, linear alkylene
oxides, such as ethylene oxide, propylene oxide, the
butylene oxides, and the pentylene oxides. Although not
preferred, alicyclic oxides, such as cyclopentylene
oxide, cyclohexylene oxide, can be used herein. Also
substituted alkylene oxides, such as styrene
oxide, can be used herein. The preferred alkylene oxide, though,
~L~6~14tS
is propylene oxide. For a more comprehensive discussion
of thase adductsr reference i5 made to U. SO Patent No.
3,746,709. Generally, from 1 par~ to 6 parts by
weight of catalyst, based on 100 parts of polyisocyanate,
will be employed in the present invention.
The fourth ingredient employed in the preparation
of the isocyanurate foams of the present invention is a
fluorocarbon blowing agent. Illustrative blowing agents
which may be employed in the present invention include
tetrafluoromethane, bromotrifluoromethane, chlorotrifluoro-
methane, dibromodifluoromethane, dichlorodifluoromethane,
trichlorofluoromethane, hexafluoroethane, 1,2,2-trichloro-
1,1,2-trifluoroethane, 1,1,2,2-tetrachloro-1,2-difluoro-
ethane, 1,2-dibromo-1,1,2,2-tetrafluoroethane, 1,2,2-
tribromo-1,1,2-trifluoroethane, octa1uoropropane, deca-
fluorobutane, hexafluorocyclopropane, 1,2,3-trichloro-
1,2,3-trifluorocyclopropane, octafluorocyclobutane-1,1,2-
dichloro-1,2,3,3,4,4-hexafluorocyclobutane, and 1,2,3,4-
tetrachloro-1,2,3,4-tetrafluorocyclobutane. Generally,
from 10 parts to 40 parts by weight of fluorocarbon
based on 100 parts of polyisocyanate will be employed in
the subject invention.
In addition to the ingredients mentioned above,
other ingredients such as catalystst surfactants, fillers,
1~ ;
3L~6;014~3
pi~mants can also be used in the preparation of
the foams of the subJect invention. Suitable catalysts
include catalysts which promote carbodiimide linkages.
Suitable catalysts which promote carbodii.mide linkages
include the symmetrical and unsymmetrical t:riazines such
as 2,4,6-tris(dialkanolamino)-s-triazines, 2,4-bis(dialkyl-
amino)-6-N-alkylhydroxyalkylamino)-s-triazines, phospholene
oxides, methyl alcohol, fururyl alcohol.
Suitable urethane catalysts include tertiary
aminesj such as diethylene triamine ketimine, tetramethylene
diamine, triethylene diamine, tetramethylbutane diamine,
tetramethyl guanidine, trimethyl piperazine and metallo-
organic salt catalysts which are polyvalent metal salts of
an organic acid having up to about eighteen carbon atoms
and being vold of active hydrogen atomsO The organo
portion of the salt may be either linear or cyclic and
saturated or unsaturatedO Generally, the polyvalent metal
has a valence from about two to four Typical metallo-
organic salts include stannous acetate, stannous butyrate,
stannous 2-ethylh~xoate, stannous laurate, stannous oleate,
stannous stearate, lead cyclopentane carboxylate, cadmium
cyclohexane carboxylate, lead naphthenate, lead octoate,
cobalt naphthenate, zinc naphthenate, bis(phenyl mercury)
dodecyl succinate, phenyl mercuric benzoate, cadmium
-13~
.
~60~
naphthenate, dibutyl-tin dilaurate and dibutyltin di-2-
ethylhexoate. Generally, catalysts, when used, will be
employed in an amount ranging from 0.01 part to 7.5
parts by weight, based on the weight of polyol, and
preferably from 0 05 part to 4.0 parts by weight
thereof per 100 parts by weight of polyol. Surfactants
which can be used are the conventional surfactants used
in urethane preparation such as the polysiloxanes or the
alkylene oxide adducts of organic compounds containing
reactive hydrogen atoms.
Generally, the surfactant is employed in an amount
ranging from 0.01 part to 5 parts by weight thereof per
hundred parts of pol.yol, Conventional ~illers for use
herein include, for example, aluminum silicate, calcium
silicate, magnesium silicate, calcium carbonate, bariu~
sulfate, calcium sulfate, carbon black and silica. The
filler is normally present in an amount ranging from
5 parts to 50 parts by weight thereof per hundred parts -:
by weight of polyol, and preferably from 15 parts to 45
parts by weight thereof per one hundred parts by weight of polyol.
-14-
:, . . . .
1061~L48
The pigment which can be u~ed herein can be
selected from any conventional pigment heretofore dis-
closed in the art, such as titanium dioxide, zinc oxide,
iron oxides, antimony oxide, chrome green, chrome yellow,
iron blue siennas, molybdate oranges, organic pigments
such as para reds, benzidine yellow, toluldine red, toners,
and phthalocyanines.
In the Examples which follow, all parts are by
weight unless otherwise stated. In addition, the physical
properties of the-foams were determined i~ accordance with :~
standard ASTM test procedures.
,
1~6~4~
EXAMPLE I
A polyisocyanurate oam was prepared by spraying
onto a cardboard panel the following ingredients and
am~unts thereof:
Ingredients
Polyol ~ (as described
supra) l9.Y
Trichlorofluoromethane 22.7
Tris(dimethylaminopropyl~-
hexahydrotriazine (TDH) 3.0
Furfuryl alcohol 3.0
Silicone surfactant 0.5
Dibutyltin diacetate l.0
Polyphenylpolymethlene-
isocyanate (functionality 2.7) 100
The physical proparties o~ the resulting foam
were as ollows:
Density, pcf.
core 2.2
over-all 2.3
Tensile strength at R.T., psi. 38.5
Shear strength, psi. 24.0
Friability
Tumbling, ~ wt. loss 7.0
Taber, cycles/in. 174
-16- :
`-` 1060148 ~: ~
Moisture Vapor Transmission 4.2 .~
", ;~
Water absorption, lbs./sq ft. 0.06 `~
K Factor at 75F.
mean temperature
initiai 0.13 .~ :
after 10 days at 140F. 0.I6
Butler chimney Test
% weight retained 95.0 .
; ! ' . .
flame height, in. 6.0 .. ;~
time to extinguish, seconds 10.0 `
",: ~ ~
Oxygen Index 24.3 ;~
Simulated service tests, .`~
%volume change
158F., 100% R.H. (Relative Humidity)
1 day 1.8
2 days 2.3 `~
7 days 5.1 ` ; :
14 days 4.6 . .. ; `~
28 days 3.6 .
250F., dry heat
1 day
2 days . -1.1
7 days 0 5
14 days. -0.5
28 days` _0.4
,
,. . ~ , ,,
''''' ~' '` ~ '' '
`'': `'` ~"
-17-
: ''`;
`~ ~. :..
. . ~ . . . . . . . . .
r
~6~
Simulated service test t
% volume change (cont.)
-20F
1 day ~0 3
2 days 0.2
7 days 0.1
Compressive strength, psi
at yield pt., R.T. 42.7
250F. 27.1 ~ ;-
% of original 63.5
400F. 11.0
% of original 25.8
at 10% defl., R.T. 42.7 : .
250F. 28.5 .
% of original 66.7
400F. 10.7
% of original 25.1
EXAMPLE II ~ :
A polyisocyanurate foam was prepared from the
following formulation~
IngredientsParts by Weight
Polyol B (as described
supra) 19.8
Trichlorofluoromethane22.7
Tris(dimethylaminopropyl)-
hexahydrotriazine (TDH)3.0
:
:
-18-
.
: . . .. .
`- 106~4~
Furfuryl alcohol 3.0
Silicone surfactant 0.5
Dibutyltin diacetate 1.0
Polyphenylpolymethylene-
isocyanate (functionality 2.7) 100
The physical properties of the result:ing foam
were as follows~
Density, pcf.
core 2.2
over-all 2.3
Tensile strength at R.T. psi.41.0 ~;-
Shear strength, p3i. 22.0 ~ -~
Friability
Tumbling, % wt. 1088 6.0
Taber, cyales/in. 208
Moisture Vapor Transmission 4.2
Water absorption, lbs.jsq. ft. 0.06 `
K Factor at 75F.
mean temperature
initial 0.13
after 10 days at 140F. 0.16
~utler Chimney Test - `
% weight retained 95.0
flame height, in. 5.7
kime to extingulsh, seconds10.0
; ~
, . ''
--19-- .:
,: , : .
, . - . . : . -
~o~
Oxygen Index 25.
Simulated service tests
% volume change
158F., 100% R.H.
1 day 1.5
2 days 1.8
7 days 3.2
14 days 3.8
28 days 1.7
250F., dry heat
1 day -0.4
2 days ~0-7
7 days ~0-5
14 days 1.2
28 days -0.3
-20F.
1 day -0.2
2 days 0.2
7 days -0.2
20Compressive strength, psi.
at yield pt., R.T. 41.7
250~F. 26.4
% of original 63.3
400F. 11.7
% of original 28.0
-20-
Compressive strength, psi ~cont.)
at 10% defl., R.T. 41.9
250 F . 30 .1
% of original 71.8
400F. 13.5
% of original 32.2
The above Example was duplicated with the exc~p-
tion that 2, 4,6-tri(dimethylaminomethyl)phenol was employed
as trimerization catalyst in lieu of TDH. The reaction was
so slow that a stable foam was not obtained.
EXAMPLE III :
An isocyanurate foam was prepared from the follow-
ing formulation:
In~redients Parts by Weight
Pol~ol C (as described 19.8
supra) ::
Trichlorofluoromethane 22.7
Tris(dimethylaminopropyl)-
hexahydrotriazine (TDH) 3.0
Furfuryl alcohol 3.0
Silicone surfactant 0.5
Dibutyl~in diacetate l.0
Polyphenylpolymethylene-
isocyanate (functionality 2.7) lO0
The physical properties of the resulting foam
were as follows:
Density, pcf.
core 1.9
over-all 2.0
-21-
. . .
Tensile strength at R.T., psi. 39.0
Shear strength, psi. 22.0
Friability ~
Tumbling, ~ wt. loss14.0 ~ ;
Taber, cycles/in 116
Moisture Vapor Transmission 3.6 ~;
Water absorption, lbs./sq. ft. 0.06
K Factor at 75F.
mean temperature
initial 0.13 ~;
after 10 days at 140F. 0.16 -
Butlex Chimney Test
% weight retained 88.0
flame height, in. 8.7
time to extinguish, seconds 11.3
Oxygen Index 22.8
Simulated service tests,
% volume change
158F., 100% R.H.
l day 2.5
2 days 3.0
7 days 5.1
14 days 5.9
28 days 5.3
-22-
1~601~8
Simulated service tests, ` ~.
% volume change (cont.)
250F., dry heat
1 day 1.-
2 days 1~7 :
7 days 2.9
14 days 4.6 :~.
.. ;
28 days 6.0
-20F
1 ~ay -0.9
2 days -0.2
7 days -1.3
Compressive strength, psi.
at yield pt., R.T. 42.1
250F. 27.7
% of original 65.7
400F. 10.4
~ of original. 24.7
at lQ% defl., R.T. 42,1
250F. 31,2
of original 74~1
400F. ~7,7
% of original 18.3
. ~
-23- ~ .
