Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
I~GW(1-103~
,.
16~5~L588
W~TER IMPERMEABLE POLYU~ETHANES
Thls ~nvention relates to novel water impermeable,
hydrophobic polyurethane foams and to novel compositions and
methods ~or producing such foams.
It is well known that a polyurethane can be prepared
by reacting organic poly-functional isocyanates with organic
compounds having two or more reactive hydrogen atoms as
determined by the Zerewitinoff reaction. When this reaction is
conducted under anhydrous conditions~ the resulting polyurethane
may be non-porous. If a cellular or foamed product is desired,
water and an excess of lsocyanate must be added to the mixture.
When water reacts with the excess isocyanate groups not previously
reacted,carbon dioxide is formed and entrapped in the reaction
mixture. A cellular or foamed product may also be prepared by
including a low boiling solvent such as trichlorofluromethane 9
l trichlorotrifluromethane, methylene chloride and the like. Also
low boiling solvents and water may be used in the mixture to form
a cellular product. Various materials have been employed as
catalysts or activators in the formation of polyurethanes.
The preparation of ~oam from polyurethanes requlres
a predetermined control of the blowing or gas forming reaction
which liberakes the carbon dioxide. It has been found that the
desired foam tlme or rise time should be about 20 to lOO seconds,
typically about 70 seconds measured under commercial conditions
in environmental temperatures of about 25C. Although many
systems ha~e been tried, there is no simple commercial system
which will permit the production of water impermeable~
hydrophobic polyurethane foams.
- 1 -
:
~5~L5~3~
It is an object of this invention to provide a water impermeable,
hydrophobic foam product based on polyurethane. It is a further object of
this invention to form water impermeable, hydrophobic polyurethane for
applications where elimination of water penetration is necessary. Other ob-
jects will be apparent to those skilled in the art on inspection of the
following description.
The present invention provides a process for preparing a water-
impermeable polyurethane plastic which comprises mixing: (a) an organic
polyisocyanate; (b) a primary or secondary hydroxy-terminated polyalkylene
ether having from 2 to 4 hydroxyl groups and a molecular weight from about
500 to 10,000 and having a reactive hydrogen atom as determined by the
Zerewitinoff method; and (c) water or a mixture of a low boiling solvent and
water, in the presence of: (1) from about 0.005 to about 5 parts of a gel
catalyst per part of blow catalyst, wherein said gel catalyst is selected
from the group consisting of, Sn(OCORt)2 wherein R~ is a hydrocarbon radical
containing up to 17 carbon atoms; and Rl SnXb wherein Rl is as defined above,
X is selected from the group chlorides, negative residual organic carboxylic
acids RCOO~ or captides RS, alcohols RO, and esters of mercapto acids
ROOC(CH2) S wherein R is a hydrogen atom or an aIkyl radical containing up to
17 carbon atoms; (2) from about 0.005 to 5 parts by weight per 100 parts by
weight of the polyol of a blow catalyst selected from: tertiar~ amines;
metal soaps of the formula M(OCR") wherein R" is an organic acid radical con~
taining up to 21 carbon atoms, n is a valance of the metal atom, and the me-
tal form is selected from the group consisting of antimony, bismuth, arsenic,
manganese~ iron, cobalt, nickel, alkali metal (including ammonium), alkaline
earth metal, silver~ zinc~ cadmium, aluminum, or lead; and an organotin
compound of ~he formttla R~3SnX~ wherein R' is as defined above and X~ is a
negative residue from an organic carboxylic acid, a mercaptan, an alcohol,
a phenol, or a halogen acid; or a mixture thereof; (3) from about 5 to 70
- 2 -
,: . . . ~ . . .
.. .. . , - ~
~051~88 ~
parts by weight of the polyol of a hydrophobic composition comprising at least
one hydrophobic organic compound containing at least one active hydrogen and
having from 10 to 21 carbon atoms.
The present invention also provides a novel composition suitable
for use in the production of water-impermeable polyurethane foams by the re- ;
action of (a) an organic polyisocyanate; (b) a primary or secondary hydroxy-
terminated polyalkylene ether having from 2 to 4 hydroxyl groups and a mole-
cular weight from about 500 to lO,OOO and having a reactive hydrogen atom
as determined by the Zerewitinoff method; and (c) water or a mixture of a low
boiling solvent and water, which comprises essentially a hydrophobic composi-
tion comprising at least one hydrophobic organic compound containing at least
one active hydrogen and having from lO to 21 carbon atoms.
The foaming agent system of this invention provides an easily con- ;
trolled foamillg process. The no~el preferred hydrophobicity impàrting com-
pounds are straight chain alcohols exhibiting of from lO to 21 carbon atoms,
such as lauryl alcohol, heptadecanol cetyl ilcohol, eicosanol non-adecanol,
. ,
octadecanol, etc. The alkyl compounds may be any compound of the formula ~; ~
. .
(YRZ)n, wherein Y and Z are selected from the group consisting of mercapto,
, "~ ',.'3 ! 0
~ SH, hydroXyl~ -OH, and-o~ 3R4D~ wherein R is a hydrocarbon of at ;~ '~
least about lO carbon atoms and n is an integer of from l to 4. Thus~ when
the alkyl compolund containing at least one alkyl group exhibiting from about ~;
lO to about 21 carbon atoms
."-;. '. '~ `.
.. . .
'": ` ' ~ '
;', ':"j - ,',
. -: .. ::
s'i ~ - 2a - ;`- -
10515138
per active hydrogen atom capable of reacting with an lsocyanate
is a mercaptan, the mercaptan may be lauryl mercaptan, undecyl
mercaptan, etc. The hydrophobic component is present in an
amount from 5 parts to 70 parts by ~eight o~ the organic polyol.
Polyols used in making the polyurethanes of the
present invention are primary and secondary hydroxy-terminated
polyoxyalkylene ethers having from 2 to 4 hydroxyl groups and
a molecular weight o~ ~rom about 500 to 10,000. They are
liquids or are capable o~ being lique~ied or melted for handling
in the polyurethane foaming apparatus or machine.
Examples o~ polyoxyalkylene polyols include linear
and branched polyethers having a plurality o~ ether linkages
and containing at least two hydroxyl groups and being substan-
tially free from functional groups other than hydroxyl. hmPng
the polyoxyalkylene polyols which are useful in the practice
of this invention are the polyethylene glycols, the polypropylene
glycols, and polybutylene ether glycols. Polymers and copolymers
of polyoxyalkylene polyols are also adaptable in the process o~
this invention as well as the block copolymers of ethylene
oxide and propylene oxide. Among the copolymers o~ polyoxyalkyl-
ene polyols that deserve some special mention are the ethylene
oxide, propylene oxide and butylene oxide adducts o~ ethylene
glycol, propylene glycol, diethylene glycol, dipropylene glycol, ~ -
tr~ethylene glycol, 2-ethylhexane-diol-1,3~glycerol, 1,2 J 6-
hexanetriol~ trimethylolpropane, trimethyolethane, tris(hydroxy-
phenyl~ propane, triethanolamine, triisopropanolamine,
.
... . ~
10~15138
ethylenediamine, and ethanolamlne. Linear and branched
copolyethers of ethylene oxide and propylene oxide are also
useful in mak~ng the foamed products of this invention with
the preferred ones being those end-blocked with ethylene oxide
to provide primary hydroxyl groups in the polymer and having
molecular weights of from about 1000 to 5000.
~ Further useful types of polyetherpolyols are block
copolymers prepared from propylene oxide and ethylene oxide.
These polyethers can be characterized by the general formulae:
CH~
H(0-CH2-CH2)x(0-CH-CH2)y(0-CH2-CH2)zOH
and (A)
CH3 fH3
H(O-CH2-CH2)a(O-CH-CH2 ~ (CH2-CH-O)b(CH~-CH2-O)aH
N-CH 2 -CH 2 -N
H(0-CH2-CH2)a(0-fH-CH2)b ~CH2-fH-O)b(CH2-CH2-O)aH
CH3 CH~
(B~
wherein Formula A the total o~ subscripts, x~ y, and z represent
positive integers in the range of from 20 to 70 and the total of
subscripts a and b of Formula B represent positive integers in
the range of ~rom 20 to 100.
Polyethers having a branched chain network are also
useful. Such branched chain polyethers are readily prepared
~rom alkylene oxides of the type above described and initiators
having a functionality greater than two. Branched polyethers
have the advantage of making possible cross linking without the
. .
1051588
interaction of urea or urethane groups with the isocyanate
groups. This has the advantage of making a larger proportion
of the isocyanate used available for the evolution of carbon
dioxide and the reducing o~ the overall amount of isocyanate
that is required in the preparation of the foamed polymer.
Mixtures of polyether polyols can be used.
Examples of these polyoxyalkylene polyols include
polypropylene glycols having average molecular weights of
500 to 5,000 and reaction products of propylene oxide with
linear diols and higher polyols, said higher polyols when
employed as reactants giving rise to branched polyoxyalkylene
polyols; and ethylene oxide, propylene oxide copolymers having
average molecular weights of 500 to 5,000 in which the weight
ratio of ethylene oxide to propylene oxide ranges between
10:90 and 90:10, including reaction product mixtures of
ethylene oxide and propylene oxide in the said ratios with linear
diols and higher polyols.
Examples of linear diols referred to as reactants with ~-
one or more alkylene oxides include ethylene glycol, propylene
glyool, 2-ethylhexanediol-1,3 and examples of higher polyols
include glycerol, trimethylol propane, 1,2,6-hexane triol,
pentaerythritol and sorbitol.
Another class of polymers having termlnal groups that
contain reactive hydrogen atoms suitable for reaction with
polyisocyana~es are lactone polymers, preferably those exhibiting
molecular weights within the range of 500 to 10,000.
~a~5158~3
In the preparation of a cellular polyurethane, water
is mixed with the condensation product of an alkylene oxide
and an organic polyiso^yanate to produce carbon dioxide which
acts as a blowing agent. Many foaming or blowing catalysts may
be used to accelerate the formation of cellular polyurethane.
It is a feature of this invention that the synergistic
blowing catalyst combination herein noted may be used in
connection with a wide variety of gel catalysts including for
example dibutyltin dilaurate and stannous 2-ethylhexoate, etc.
In practice of the preferred embodiment of this invention, the
preferred gelatin catalyst which may be employed may be selected
~rom the group consisting of Sn(OCOR)2 and R'aSnXb. Other
equivalent gelation catalysts may be employed. In the stannous
compounds, Sn(OCOR)2, R may be a hydrocarbon residue typically
alkyl~ alkenyl, aryl, aralkyl, alkaryl, cycloalkyl, etc. R may,
for example, be methyl, ethyl, propyl, isopropyl, n-butyl,
isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl,
undecyl3 oleyl i.e. 7-heptadecenyl, etc., phenyl, o-, m-, or
p-tolyl, naphthyl, cyclohexyl, benzyl, etc. The nature of R
will, o~ course, define the group -OCOR3 when R is methyl, for
example, this group may be the acetate group. Preferably,
however, the R group will contain at least about 7 carbon atoms
and less than about 17 carbon atoms. When R is heptyl, the
group -OCOR may be the 2-ethylhexoate group; when R is 7-hepta-
decenyl, the group -OCOR is the oleate group, e~c. The preferred
compounds which may be employed is stannous 2-ethylhexoatç and
stannous oleate.
. ..
. . .- .- ....... , . . ,-
: . . . . .
10515198
In the organotin compounds R'aSnXb, R' may be the
same as R. Preferably R' will be a hydrocarbon residue,
typically alkyl, alkenyl, aryl, alkaryl, aralkyl, cycloalkyl,
etc. R' may be, for example, methyl, ethyl, propyl, isopropyl,
n-butyl, isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl,
decyl, undecyl, oleyl, i.e. 7-heptadecenyl, etc., phenyl, o-,
m-, or p-tolyl, naphthyl, cyclohexyl~ benzyl, etc. The sum of
a and b will be 4, and either of a and b may be 1, 2, and'3.
The preferred R' group is the n-butyl group C4H9-.
In the organotin compounds R'aSnXb, X may be selected
from the group consisting o~ chlorides and the negative residual
portions of organic carboxylic acids RCOO-, mercaptides RS~,
alcohbls RO-, esters of mercaptoacids ROOC(CH2~nS whe`rein R may
be hydrogen or the other residues' hereinbefore'noted; etc.
Typical specific residual portions may include the-2-ethylhexoate
the lauryl mercaptide, the methoxide, and the isooctyl thiogly-
colate. '
~he pre~erred organotin compounds R'aSnXb' may be
those wherein a and b are 2; e.g. dibutyltin dilaurate and
dibutyltin di-2-ethylhexoate.
In the practice o~ this invention, the gel catalyst
and the novel blowing catalyst combination may be present in
ratio o~ 0.01 to 5 parts, say 1 part of the former per part
of the latter. In one pre~`erred embodiment, when the blowing
catalyst combination o~ this invention is used with stannous
2-ethylhexoate as the gel catalyst, the ratio will be approximate y
1. ' ':,
- - . - - . , .-
, . . , ., .:
:105:~5i88
Preferably the catalyst mixture will be present in
catalytic amount corresponding to 0.01 to 5, say o.6 par~s
by weight per 100 parts o~ polyol. Preferably, the blowing
catalyst will be present in a catalykic amount corresponding
to 0.005 to 4.95, say 0.3 parts by weight per 100 parts of
polyol, and the gel catalyst will be present in catalytic
amount corresponding to 0.005 to 4.2 parts~ say 0.3 parts by
weight per 100 parts of polyol.
It is also a feature of this invention that the
combination herein noted may be used in connection with a wide
variety of blowing or foaming catalystsO These may include
tertiary amines, metal soaps wherein the metal may be antimony,
bismuth, arsenic, manganese, iron, cobalt, nickel, alkall metal
(lncluding ammonium), alkaline earth metal, silver~ zinc, cadmium
aluminum, or lead, or organotin compounds having the formula
R'3SnX' wherein R' is hydrocarbon and X' is selected ~rom the
group consisting of the negative residual portlon of an organic
carboxyllc acid, a mercaptan, an alcohol, a phenol, and a
halogen acid.
Typlcal tertiary amines whlch may be employed as
blowlng catalysts include N-alkyl morpholines, e.g. N-methyI
morpholine, N-ethyl morphollne (NEM) and cyclic triethylene
diamine includin~, e.g. that which is sold under the trademark
DABC0. Particularly pre~erred tertiary amine bIowing catalysts
may contain N-ethyl morpholine or cyclic triethylene diamine
or mixtures ~hereof~ the mixtures containing say about 1-2 parts
by weight of cyclic triethylene diamine per 3 parts of N-ethyl
- :: - -. -
105158
¦ morphol~ne. Tertlary amlne blowing catalysts may be particularly
¦ desirable when fast rlse times are desired.
Typical metal soaps which may be employed as blowing
l catalysts include compounds having the formula M(OOCR")n
¦ wherein M is selected from the group consisting of antimony,
bismuth, arsenic, manganese, iron, cobalt, nickel, silver~
zinc, cadmium, aluminum, and lead, R" is a hydrocarbon group
and n is a small whole integer corresponding to the valence
of M, typically 1, 2, 3, etc. Preferably n is 1 and the acid
from which the soap is derived is monobasic. Among the
hydrocarbon groups which may be represented by R", the following
may be particularly noted: aliphatic or cycloaliphatic groups
such as alkyl, alkenyl, etc. and corresponding cyclic groups
sueh as cycloalkyl, etc.; an aryl group such as phenyl,
subs~ituted phenyls, naphthyl, etc.; an aralkyl group such as
benzyl, styryl, cinnamyl, etc.; an alkaryl group such as tolyl,
xylyl, etc.; a eycloaliphatic group such as a naphthenie group;
etc. Other equivalent groups may be employed. In a pre~erred
embodiment, R" may be an alkyl group having less than about
21 carbon atoms. Typieal of the acids from which the soaps may
be prepared may be aeetie aeid, propionic acid~ butyric acid,
caproic acid, eaprylie acld, caprie aeid, stearie acid, oleic
aeid, ete. Naphthenie acid may be employed. The commercially-
oecurring mixture of acids known as "tall oil fatty aeids" may
` be employed. When the metal M is antimony, bismuth or arsenie,
the pre~erred R" group may be an aliphatic group having 6-21
carbon atoms. Typical preferred aeids from whieh these
... ~ _ g _
~051S~318
particular soaps may be prepared include 2-ethyl hexoic acid,
pelargonic acid, oleic acid, tetrachlorobenzoic acid, cyclohexyl
carboxylic acid, and commercially-occurring mixture of tall oil
fatty acids.
Specific metal soaps include: antimony tri-2-ethyl
hexoate; antimony tripelargonate; arsenic trioleate; antlmony
tritallate; bismuth tri-2-ethylhexoate; arsenic tripelargonate;
antimony tri(tetrachlorobenzoate); antimony tri(cyclohexyl- .
carboxylate); bismuth trioleate; ferric stearate; manganous
iO stearate; cobaltous stearake; cobaltous naphthenate; ferric
linoleate; manganous linoleate; ferrous stearate; nickel stearate; . :
calcium naphthenate; ammonium stearate; dimethylammonium stearate; :. :
trimethylammonium stearate; calcium stearate; magnesium stearate;
. barium stearate; lithium stearate; sodium stearate; strontium
stearate; potassium oleate; ammonium tallate; strontium 2~ethyl-
hexoate; lead naphthenate; æinc naphthenate; aluminum monostearate ;
aluminum distearate; aluminum trlstearate; plumbous ~tearate;
plumbous stëarate (basic); zinc stearate; cadmium stearate,
silver stearate; silver acetate; l~ad pelargonate. Preferred
metal soaps include: antimony tritallate; manganese linoleate; . .
. ferrous stearate; nickel stearate; calcium naphthenate; barium
stearate; sodium stearate; calcium stearate; zinc naphthenate;
plumbous stearate; and aluminum distearate. Most highly preferred
metal soaps include: manganese linoleate; calcium naphthenate;
cadmium stearate; and particularly antimony tritallate.
_ 10 -
10~1588
¦ In the practice o~ this invention, according to certain
¦ of i~s aspects/ when a blowing catalyst is employed, the curing
¦ catalysts may be present in a ratio of 0 1-5 parts by weight to
¦ 1 part by weight of blowing catalyst, preferably 0.5-2.5 to 1. ~,
¦ Preferably the catalyst mixture will be present in
catalytic amount corresponding to 0.01 to 5, say o.6 parts by
weight per 100 parts of polyol. Preferably, the blowing catalyst
will be present in a catalytic amount corresponding to 0.005 to
4.95, say 0.3 parts by weight per 100 parts of polyol, and the
gel catalyst will be present in a catalytic amount corresponding
to 0.005 to 4.2 parts, say 0.3 parts by weight per 100 parts of
polyol.
The process of this invention is particularly adapted
for making both cellular polyurethanes and non-porous poly-
urethane plastics. The hydrophobic compositions provided by this
lnvention are efficacious in preparing water-impermeable
urethane products by casting processes or by processes in which `
a millable gum is ~ormed. In processes of this type, the
condensation product of an alkylene oxide is reacted ~ith an
organic polyisocyanate and a at least one alkyl compound
exhibiting from about 10 to about 21 carbon atoms per active
hydrogen atom capable of reacting with an isocyanate.
A variety o~ organic polyisocyanates may be used in the
practice of this invention although diisocyanates are preferred
in many formulations. Suitable polyfunctlonal isocyanates
include alkylene diisocyanates such as hexamethylene
dilsocyanates~ and decamethylene diisocyanates, tolylene
' ~, '' ' ` ':` : " ' ' ' . . - '` " ` '
10515~8
diisocyanates, naphthalene diisocyanates, 4,4'-diphenylmethane
diisocyanates, isomers or mixtures of any of these.
Triisocyanates typically obtained by reaction with 3 moles of an
arylene diisocyanate with l mole of a triol, e.g. the reaction
products formed from 3 moles of tolylene diisocyanate and 1 mole
of hexane triol may be employed. A preferred polyisocyanate ls
the mixture of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene
diisocyanate.
The term "isocyanates" is used herein to refer to
polyisocyanates and to polyisothiocyanates, respecti~ely,
including particularly diisocyanates and diisothiocyanates.
While the invention has been described specifically with referenc~
to the reaction of certain diisocyanates, it is generically
applicable to the reaction of any compound containing two or
more -N=C=G groups in which G is oxygen or sulfur. Compounds
within this generic definition include polyisocyanates and
po,lyisothiocyanates of the general formula
RtNcG)x .
in which x is two or more and R can be alkylene, substituted
alkylene, arylene, substituted arylene, a hydroaarbon or
substituted hydrocarbon containing one or more aryl -NCG bonds
and one or more alkyl -NCG bonds, a hydrocarbon or substituted
hydrocarbon containing a plurality of either aryl -NCG or
alkyl -NCG bonds. R can also include radicals such as -R-Z-R
~here Z may be any divalent moiety such as -0-, -O-R-O-, -C0-,
-C2-~ -S-~ -S-R-S-, -SO2-, etc. Examples of such compounds
~ '1'
.~ . , . . ~ . .
I ~OS~S8~
include hexamethylene diisocyanate, 1,8~diisocyanate-p-methane,
¦ xylylene diisocyanates, (OCNCH2CH20CH2)~ methyl-2,4-diiso-
cyanate-cyclohexane, phenylene diisocyanates, tolylene diiso-
l cyanates, chlorophenylene dilsocyanates, diphenylmethane-4,4'-
¦ diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane-4,
4',4"-triisocyanate, xylene-~,a'-diisothiocyanate, and
isopropylbenzene-a,4-diisocyanate.
Further included are dimers and trimers o~ isocyanates
and diisocyanates and polymeric diisocyanates o~ the general
formulae
(RNCG)X and CR(NCG)X] Y : .
in which x and y are two or more, as well as compounds of the :
. general ~ormula
. M(NCG)X
in which x is two or more and M is a di~unctional or poly-
functional atom or group. Exampies o~ this type include
ethylphosphonic diisocyanate, C2H~P(O)(NCO)2, phen~lphosphonic
diisocyanate, C6H~P(NCO)2; compounds containing a _Si-NCG group,
isocyanates derived from sulfonamides (RSO2NCO), cyanic acid,
~0 and thiocyanic acid.
Substances having two or more active hydrogen atoms
determined by the Zerewitino~ method operative in the practice
of this invention are those organic compounds having two or more
reactive hydrogen atoms which react with organic poly-~unctional
isocyanates to give urethane polymers. The amount of isocyanate
employed generally ranges ~rom 1 to 7 equivalents prererably
2 to 6 equivalents, per equivalent o~ polyether. :
. . . .
~os~s~
The reaction of excess diisocyanate with a poly-
oxypropylene glycol produces a polymer having terminal iso-
cyanate groups. I~en it is desired to form a foam, the mixture
of the isocyanate-modified polyether reacts through the isocyanate
groups with a chain-extending agent containing active hydrogen
such as water. This involves several reactions that proceed
simultaneously including the reaction between the isocyanate
groups and wa~er to form urylene links (-NHCONH-) and carbon
dioxide, as well as the reaction of the urylene links so
formed with unreacted isocyanate groups to form biuret cross
links. Depending upon the desired density of the urethane foam
and the amount of cross linking desired, the total isocyanate
equivalent to the active hydrogen equivalent should be such as
to provide a ratio of 0.8 to 1.2 e~uivalents of isocyanate per
equivalent of ac~ive hydrogen, and preferably a ratio of about
0.9 to 1.1 equivalents.
Cell modifying agentsJ e.g. silicones such as tri-
methyl end-blocked dimethyl polysiloxanes may also be used in the
practice of this invention.
Other well known constituents can be added to the poly-
urethane foam recipe such as clay, talc, Ti02, silica and hydrated ~`
silica, CaC03, metal chromates, barytes, phthalocyanine green or
blue pigments, red iron oxide, conventional stabilizers, carbon
black, dyes, toners, epoxidized soy bean oil ~Paraplex G-62-
trademark), epoxides (Epon 828-trademark), ~ricresyl phosphate,
antioxidants, fungicides, bacteriostats and the like. These
constituents can
-14-
" . . . : . . ~
i , ~ . . - . - .
1051588
be added in various amounts to the foaming ingredlents to achieve
the desired properties in the resultant flexible, low density
foams. `
The preparation of the polyurethane foams of the present
invention can be formed by a process known in the art as the
"one-shot" process by a two step process involving, first, the
preparation of a "prepolymer," the well known "semiprepolymer"
or "quasi-prepolymer" technique. There all or a portion of the
polyol is reacted with all of the organic polyisocyanate,
providing a reaction product which contains a high percentage
free isocyanate groups and which is reacted with the remaining
portion of the hydroxyl-terminated polyol or a crosslinker,
together with water, catalysts, and metal oxides to ~orm a
rubbery, cellular, elastic product.
The following examples are intended to illustrat;e
more fully but not to limit the invention~ which is properly
delineated in the claims.
.
.
105~58~ ~
EXAMPLE 1
Practice of this invention according to a speci~ic
embodiment may be observed by ~orming a typical one shot poly-
ether flex~ble foam by mixing the ~ollowing components:
Part A
1. Amine based polyoxypropylene 2,960 parts
polyether polyol with a M~ of
about 3600 and capped with
ethyleneoxide having an OH
number o~ about 62.
2. A C12 to C13 linear primary 592 parts
alcohol.
3. Carbon black paste. 65 parts
4. Dibutyltindilàurate 3 parts
5. Triethylenediamine 1.5 parts
6. Dimethyl polysiloxane ~luid 1 part
7. Water 37 parts
Part B
1. Polymethylene polyphenylisocyanate 1,464 parts
having an equivalent weight of about
` 133.
Part A was mixed with Part B with rapid stirring for several
seconds and poured into a suitable mold. The mass swelled to
form a cellular polymer. A~ter the mass has cured, a 1" thick
section o~ ~oam was sliced ~rom the bun and a "U" shaped section
was cut having about a 1 square inch cross section. The sample
was compressed about 50% between two plexiglass plates and water
` ' ' ,
~ 3S~5~8
poured therein. It was observed that the water makes a high
contact angle with the foam sur~ace. .~fter several hours it
was observed that water has not passed through the foam.
EXAMPLE 2
The process of the foregoing example was used except
that the composition was comprised of the following mixture of
components:
Part A
l. ~ polyoxypropylene polyol containing 690 parts
polystyrene polyacrylonitrile and
capped with oxyethylene having an OH
number of about 27.
2. A C13 to C14 linear primary alcohol 80 parts
3. Carbon black paste 15 parts
4. Dibutyltindilaurate 0.5 parts
5. Bis(2-dimethylaminoethyl) ether2 parts
6. D~methylpolysilo~ane fluid0.05 parts
7. A silicone glycol copolymer0.15 parts
8. ~ater 10.7 parts
Part B
l. Polymethylene polyphenylisocyanate 270 parts
having an e~uivalent weight o~ about
133.
Part A was mixed with Part B as described in Example l. Testing
of the foam for resistance to water penetratlon as described in
Example 1 yielded results that demonstrated unusually hlgh
hydrophobic properties.
. ~ . . . .
1051S88
¦ Although this invention has been illustrated by
¦ reference to specific embodiments, modifications thereof which
¦ are clearly within the scope of the invention will be apparent
¦ to those skilled ln the art.
