Note: Descriptions are shown in the official language in which they were submitted.
49
.; . ~.
The expansion of technology in the polyether
based polyurethane foam system over the last 10-15 years
~- has been tremendous. It is natural, therefore, that the
advent of a specialized area within that industry would
materialize and take a significant portion of the commer-
cial market. Such a specialized area is that of high ;~
resilience foams.
Resilience is defined as the work which a body
can do in springing back after a deforming force has
been removed. In defining resilience in polyurethane
foams, the industry generally considers a sag factor --
to differentiate conventional foams from high resilient
; foams. The sag factor is the ratio of indent load
deflection at 65~ deflection to that of the indent load
deflection at 25~ deflection. Indent load deflection
:~ is measured in lbs./50 in2. Conventional foams have `~
a sag factor of 2.0 to 2.3 while high resilient foams ;~
have such a factor of 2.8 to 3.1.
Since its introduction several years ago,
high resilience foams have~commanded a great amount
of attention from the urethane foam industry. The
material has foun~ widespread application, most sig-
, .~ ` .
; nificantly in the automobile industry for molded parts,
:- but also in the furniture and bedding industries. This
~I high acceptance has been due to the fact that most
`~ techniques from the alrea~y established polyurethane
foam industry can be utilized in high resilience foams
l and, moreover, the properties of the foam itself differ
i from ordinarily produced polyurethane foam to the extent
1 30 that for some applications, the high resilience foam is
. ~ . . .
,:j :, .
.; -1- . ~ ~,:,
.','' ' '~ ;
, .
. ,,~ ,. . .
: ,' ' ' : , ,
~6~6~
preferred. The physical pr~perties most valuable are
physical properties giving comfort~ fatigue resistance and
flame resi.stance.
With some modifications, the high resilience
- foam technology can be fitted into the already existing
polyurethane f`oam technologyO
As the foregQing indicates, the technology
of the ordinary polyurethane foam industry is applicable
to high resilient foams, but one area of the technology
is not readily transferred. The area is that portion
of the foamable compositlon which stabilizes the composi-
tion as it reacts, foams and finally solidifies. As a
matter of fact, the foam stabilizers used in existing ~ -
polyurethane foam systems cann.o.t be used.in the.new
high resilient foams because they cause severe voids
and splits in the foam and also cause severe shrinkage
of the foam slab. ;-
It has now been found that certain specially
defined polymeric materials will stabilize high -~
resilience foams without causing voids, splits and
: foam shrinkage while maintaining the other valuable
physical properties. ;` ~:
It is theref~re an object of this invention
to provide compositions and a process for producing
high resilient polyurethane foam which ~ill consistently
give foams which have a fine, uniform cell structure. ~ -.
It is a further object of this invention to
provide compositions and a process for producing high ~. -
resilient polyurethane foam which will consistently
give foams which are free of voids and splits.
-2-
Still another ob,ject of this invention is to
provide compositions and a process for producing foam
which will consistently maintain the foamed~ cured
heighth without shrinking upon cure. Yet another
object of this invention is to provide the industry with
more processing latitude than has been possible heretofore.
It has now been found that the use of certain ~-
; siloxane-oxyalkylene copolymers as foam stabilizers
in polyether based high resilient polyurethane fQams
will allow the production of foams which will have no
voi~s or splits, no slab shrinkage and useful physical `~
properties. In addition, the foam stabilizers of this
invention give the pro~ucer more process latitude in ~
-~ that he can not only utilize the foam stabilizer in ~ -
various quantities to fit his own peculiar polyurethane ;~
foam need~, but he can utilize the foam stabilizers in both
of the current, popular polyurethane foam processing
systems i.e. the polymer in p~ly~l and the cr~ss-linked
systems. ~ ~`
More speci~ically, the invention deals with
; a ~rocess for pre~aring high res1lient polyurethane foam,
which process includes the steps:
[I] Preparing a homogeneous mixture consisting
, i ~
~- essentially of
(A) 100 parts by weight of a base polyether
~ polyol selecte~ from a group consisting of ~`~
`~ (i) a polyether triol containing at
least 40 m~le ~ercent primary hydroxyl groups and `~
having a molecular weight in the range of 2,000 to
8,ooo grams per mole and
(ii) a mixture of (i) and an additional
.,
,,, . .
-3- -;
: " :
,
.. . . .
9 ~ ~ ~
polye-ther polyol havi.ng an average of at least two : .
hydroxyl groupsJ wherein said polyether poly~l is :
present in the mixture (li) to at least 40 weigh-t
percent of the total polyether polyol content of (ii), -~ ;
(B) a sufficient amount of organic polyiso-
cyanate to give from 90-120 percent, on a stoichiometric
basis, of isocyanate radicals for each hydroxyl radical
in the composition,
- ,; .~,
(C) a catalytic amount of a catalyst for ::~
: 10 the production of the high resilient polyurethane foam,
,: .
(D) 1-10 parts by weight of a blowing agent, .~ -~
.` (E) a foam stabilizing amount of a siloxane-
; oxyalkylene copolymer selected from a group consisting . ~:
.: . . ,
of (1), (2), (3), (4) ~r mixtures thereof wherein (1) ` ~:
has the general f~rmula . ;;:~
RaSi{(OSiMe2)eOSiMe2G3~a 3
. in which formula R is a hydrocarbon ~`~
.~ radical free ~f aliphatic unsaturation and contains ;
from 1-10 carbon atoms,
a is 0-~
,
.. Me is a Methyl ra~ical,
G is a radical selected from a group con~
sisting ~f
-D(0R")mA and
-L-D(oR1')mA wherein L is an oxygen or sulrur
atom,
D is a divalent linking radical selected
:: from the group consisting of
, ~
~ (i) al`kylene radi.cals,
; 30 (ii) radicals composed of carbon, hydrogen
and oxygen atoms, the oxygen atoms being present as
ether, ester or hydroxy groups, and
_L~_
/ .. : ~ .... . . .
: . ,~ ,
:. .. . . . .
~0~649
(;ii) radicals composed ~f carbon, hydrogen
; and sulfur atoms, the sulfur atoms being present as
thioether, thioester ~r thlol groups, th~re being no
more than 8 carbon a-toms in D, and L is bonded to a
carb~n atom of the D radical, ;~
R" is comp~sed of propylene radicals and
radicals selected from the gr~up consisting of ethylene ~ .:
and butylene radicals wherein the amount of ethylene -
and butylene ra~icals is less than 35 weight percent of
the total (OR") ra~ical, .j;
m has an average value of 1-15~
A is a radical selected from the group
c~nsisting of the -OR', OOCR', and OCQO~' radicals
'~
wherein R' is a radical free 3f aliphatic unsaturati~n :~
selecte~ from the group consisting of hydr~carbon and
. hydrocarboxy radicals, the A radical contalning a t~tal
~ of less than eleven atoms, in which formula when a = O,
then e is 0, 1 or 2; when a = 1, then e is 0, 1, 2 ~r 3;
when a = 2, then e is 0-5, and when a = ~, then e is 0-7;
(2) has the general formula
GMezSi(OSiMe2)f(0SiMeG)bOSiMe2G,
in which formula when b = O, then f is 0-7
when b = 1, then f is 0-7; when b = 2, then f is 0-5; ~:~
when b = 3~ then f is 0-4 and when b = 4, f is 0-2; ..
(3) has the general formula
RaSi{(OSiMe2)g(0SiMeG)cOSiMe3~ 4 - a ' ~:;; - ,
in which formula when a = O, g = O, then
c = 1; when a = 1, g = O, then c = l; when a = 2,
g = O, then c = 1 or 2; when a = 3, g = O, then c = 1-5; :
., , ~ : .
-5- ~ ~
., .
.. ,
`` 1~69~6g~9
when a -- 1, g = 1, then c = 1; when a = 2, c = 1, then g = 1
or 2,
(4) has the general formula
Me3Si(OSiMe2)h(OSiMeG)dOSiMe3,
in which formula h has an average value of
0-7, _ has an average value of 1-5 and when = O, d = 1-5;
when _ = 1 or 2, then _ is 1-4; when _ = 3 or 4, then _ is
1-3; when h is 5, then d is 1-2; and when- _ is 6 or 7, then
1 r
CII~ thereafter allowing the mixture to foam, and
curing the foamed composition.
Thus, in accordance with the more specific
teaching of the present concept a method is provided of pre~
paring a one-shot polyether based, high resilient polyurethane ` -`
foam. The method includes the steps of
(I) preparing a homogeneous mixture consisting
essentially of
(A) 100 parts by weight of a base polyether
,~ ~, , .
polyol selected from the group consisting of
(i) a polyether triol containing at least 40 ~ ~ ~
mole percent primary hydroxyl groups and having ~ ;
a molecular weight in the range of 2,000 to
8,000 grams per mole, and
(ii) a mixture of ci~ and an additional polyether -
polyol having an average of at least two hydroxyl
groups, wherein said polyether polyol is present ~
in the mixture (ii) to at least 40 weight percent ~ ;
of the total polyether polyol content of (ii),
(B~ a sufficient amount of organic polyisocyanate
~i 3Q to give from 90 to 120 percent, on a stoichio~ --
metric basis, of isocyanate radicals for each
hydroxyl radical in the composition,
~ kC -6-
16~6~ g
(C) a catalytic amount of a catalys~ for the ~ ~
production of the high resilient polyurethane ~ ;
foam,
(D) 1 to 10 parts by ~eight of a blowing agent, ~ ;
(E) a foam stabiliz;ng amount of a copolymer of
the general formula Me3Si(OSiMe2~h(0SiMeG)~OSiMe3
where _ has an average value of about 0, 1 or 3,
d has an average value of about 1 or 2, Me is the
Methyl radical and G is ~CH2)3(0CH2CCHHt20 3
~CH2)3(0CH2cH~20ccH3 or ~CH2)3(0CH2CH)2 50CH3
CH3 CH3
The usual method of this invention is to combine
ingredients tA), (C), (D), and (E) in any suitable container and ;~
., . . j: . ,
homogenize them using any suitable-means such as a commercial mixer
or the likeO The component (B) is then added, the mixture again f '~
homogenized and the foam allowed to rise in the container. The
foam can then be cured at room temperature (cold cured) or at
O : . ~
elevated temperatures (usually 107 C) and then removed from the
container for use later. In another method, the components can
be metered and mixed automatically so that the separate step of
adding component (B) can be eliminated. Both of these methods
are generally known in the art with the exception~of the use of i
', component (E) of the present invention. The above modes of mix~
ing are not the only methods by which the foaming composition can
be prepared. For instance, it is well within the scope of the ;
instant invention to mix the ingredients in any order in which it ' ~`
is desirable. The only exception is that component (B) '~
' "'""~':' :'
-6a~
::
(~
^ 1~64~4~ ~
canno-t be mixed with any poly~l or similarly reactive
component until the foaming is to begin
The polyether p~lyols employed in -this inven-tion
as component I(A) can be any p~]yether triol containing
; at least 40 mole percent of primary hydroxyl groups
and having a molecular weight from about 2,000 to a~ut
8,ooo grams/mole. Preferably, said polyether poly~ls
contain about 60-go mole percent of primary hydroxyl
groups and have a m~lecular weight from about 4,000 to
7,oO0 grams/mole.
The preferred polyether poly~ls ~f this
inventi~n are polyether triols obtained by chemical ';~
- addition of alkylene oxides to trihydroxyl organic
containing materials such as glycerol, 1,2,~-hexane~
triol, l,l,l-trimethylolethane, 1,1,1 trimethylolpr~pane, - `
3-(2-hydr~xyeth~xy)-1,2 propanedi~l, 3,-(2-hydr~xypro-
poxy)-1,2 propanediol and the like, as well as mixtures
there~f, i~
Alternatively, the ~olyether ~olyols can
be mixtures c~nsisting essentially ~f the above p~ly-
ether tri~ls and other p~lyether polyols having an ;
- average of at least two hydroxyl radicals per molecule,
said trisls constituting at least 40, ~referably 50 ~r
; m~re weight percent of the t~tal poly~l content of the
mixture. Such other polyether p~lyols having an
average ~f at least tw~ hydr~xyl radicals per molecule
are triols outsi~e the scope of this inventi~n, diols,
tetraols, and polymer/polyols as well as mixtures thereof. - ~
Examples of such polyether polyols containing ~ ?
at least two hydroxyl grou~s per molecule are 1,2-alkylene ; ~
.,` ':
-7- ;
:: ~
, ~ .
1~6~4~
oxides such as ethylene oxide, epichlorohydrin, ],2-
propylene oxide~ 1,2 butylene oxide and 2,3-bu-tylene
oxide, oxacyclobutane and substituted oxacyclobutanes
and tetrafuran.
They may be linear polyether glycols as are
prepared, for example, by the polymerization of an
- alkylene oxide in the presence of a basic catalyst~
such as potassium hydroxide, and a glycol as a primary
mon~amine. Alternatively there may be used branched
polyether prepared, for example, by the polymerization
of an alkylene oxide in the presence of a hasic catalyst
and a substance having more than tw~ active hydrogen
atoms per molecule, for example, ammonia and p~lyhydroxy
compounds such as glycerol, hexanetriols, trimethylol-
pro~ane and ethane, triethanolamine, ~entaerythritol,
sorbitol, sucrose an~ phenol-f~rmaldehyde reaction
products, aminoalcohols such as monoethanolamine and
diethan~lamine and polyamines such as ethylene diamine,
hexamethylenediamine, diethylene triamine, tolylene
diamine an~ di~minodi~henylmethane. ~ranched p~lyethers
,., ,.. ~
may also be ~roduced by copolymerizing a cyclic oxide
of the type already mentioned with cyclic oxides having
a functionality greater than two, for example, ~ie~oxides,
glycidols and 3-hydroxymethyloxacycl~butanes. ;;~
Another ty~e of polyether ~olyol that can be
mixéd with the above defined polyether triols and used
as starting materials are graft polymer in polyether
compositions obtained by polymeriæing ethylenically ~ ;
unsaturated monomers in a polyether as ~escribed in
~ .
3G U.S. Patent 3,383,351. Suitable monomers for producing ~
: .
::,. .
649
such compositions include~ for example, acrylonitrile,
vinyl chloride, styreneJ butadiene~ vinylidene chloride3
and the like. The most preferred is acrylonitrile at
this time. Suitable polyethers for producing such
compositions include, f~r example, those polyethers
described above. The graft polymer in ~olyether
comp~siti~ns can contain fr~m about 1 to about 70 weight
percent, preferably about 5-50 weight percent and most
preferably ab~ut 10 t~ 40 weight percent of the m~ncmer
polymerized in the polyether. Such compositions are
conveniently prepared by polymerizing the monomers
in the selecte~ ~lyether at a temperature of 40C to
150C in the presence ~f a free radical p~lymerization
catalyst, such as per~xides, persulfates, ~ercarbonates,
perb~rate and azo compounds. The resulting compositiorls
may c~ntain some unreacted polyether, m~nomer and free ~-
~olymer as well as the graft p~lymer in polyether reacted
:
species.
The ~ase p~lyethers are ncrmally used in the amount
of 100 parts by weight and the remainder of the com~onents
are based upon the ~ase poly~ls.
' Com~onent I(B), ~rganic polyis~cyanates, which
- are suitable in this inventi~n, include aliphatic diis~cy-
anates such as hexamethylene diis~cyanate, ar~matic
diis~cyanates such as toluene-2,4-diisocyanate, toluene~2
, -,,,~ ~
6-diis~cyanate and the familiar 8a 20 isomeric mixtures
of the 2,4 and 2,6 t~luene diis~cyanate, diphenyl-
methane-4,4-diis~cyanate, 3 methyldiphenylmethane
-4,4'diisocyanate, m- and p-phenylene diisocyanate. ~-
Other suitahle is~cyanates comprise the reaction
,
" _ g_
.
~- ;
1~i4~49
,
products of an excess of the diisocyana-te with poly-
hydric alc~hols such as trimethylolpropane. Still
other isvcyanates are blends of the above isocyanates - ;
such as to]uene diisocyanate and p~ly aromatic poly-
isocyanates and crude or residual polyisocyanates from -~
the pr~duction of purer species of polyisocyanates
The is~cyanates can be employed in the
inventi~n on a stoichiometric basis, that is, ~ne
isocyanate ra~ical for every hydroxyl radical. The
usual employment, however, is to utilize the-isocyanates
s~ as to give from 10% less than stoichiometric quantities ~-
~f is~cyanate radical to hydroxyl radical, t~ 20% greater `
than ~toichiometric quantities of isocyanate radical t~
hydroxyl in the system. Most ~referre~ for this inventi~n ~-~
is 5% in excess ~f the is~cyanate radicals over the
~ available hydr~xyl radicals.
;~ C0m~0nent I(C), a catalyst f~r the producti~n
of the high resilient f0am includes ~oth ~rior art amines ,~
and soluble 0rganic c~mpounds~of heavy metals either -~
singly ~r in various combinations. Exam~les-~f amines
useful in this invention include triethylenediamine
and N-ethylmorph~line and examples of ~rganic comp~unds `~
of heavy metals are dibutyltindilaurate and~stannous
octoate, Mixtures of catalysts may be advantage~us at
times. The catalysts are used in the amounts ranging
from ~.01-5.5 parts based on 100 ~arts ~f the base
polyol,
Compcnent I(D)g the blowing agent, is water
~--,:
or a low-b~iling ~rganic liquid. The bl~wing agent can
be a mixture of water and a low-boiling organic liquid
~,
. --10--
' ~
, '
,~ ~
,, . :
1~64~49 - ~
. The Low-boiling organic l~qui.d should be chemically
.
inert towards the 1socyanates and water and have a
boili.ng point less than -that of water. Preferably
much lower as for instance 75C or lessO
Low-boiling organic liquids include halogenated
alkanes such as monofluorotrichloromethane and methylene
chlorideO ";
: The blowing agent is used in the amount of ~:~
l-lO parts per l~O parts of the base polyetherO When
lO water is the sole blowing agent it is preferred to use :
from 200-~.5 parts per lOO parts of base polyether and
:; - when halogenated alkanes are the sole blowing agent it ~ :~
is preferred to use from l-lO parts per lOO parts ~f
.. ,., ~ .:~:
; base polyetherO Mixtures of halogenated alkanes are
also useful in this inventionO
The final major comp~nent I(E), is the siloxane~
oxyalkylene copolymer foam stabilizerO ~hen used in this :: ::
. . .
invention, the foam stabilizer when used without dilution
~ is utilized in the amounts ranging from 0002-200 parts
. 2Q ~er lOO parts of base ~olyether polyolO Most preferably
it is used in the range of 00 5-lo 0 parts per lOO parts
of polyether polyol
The essence of the present method is the use ~
of the nove] siloxane~oxyalkylene c~olymers, comp3nent : --
(E), in the f~aming systemO ~
It is the certain siloxane-oxyalkylene - :
copolymers, when used as foam stabilizers, that allow
the cured foam to consist of fine-uniform cells. It . ~ :
; is the certain siloxane-oxyalkylene copolymers, when ~ ;
used as foam stabilizers, that allow the cured foam ::
., .
-11-
.,
1~6~
to be clear of voids, spli-ts and holes and to be free
from slab shrinkage. It is the certain siloxane-
oxyalkylene copolymers, when used as fQam stabilizers,
that allow the cured foam t~ exhibit. physical properties -
which make it useful for molded foam applications.
Presently used polyurethane foam additives
found in the art and which fall outside the scope of
- -
this invention, do not allow one skilled in the art
to produce polyurethane foams with the above listed -
advantagesO Further, the normal polyurethane foam
additives do not give the processor the latitu~e tc ;~
produce foams fr~m the two polyurethane foam systems,
heretofore mentioned, without s~me major change~in the
foam stabilizer from one system t~ the other.
It is to be understood that the siloxane~
oxyalkylene copolymers ~f this invention are specific
materialsO It is also to be understood that whenever ` --
,. ~
, the symb~l = SiO is used in this s~ecification, it can
: G
~ 20 have two meaningsO It can be (MeGSiO3 or it can be
,-, , ,
(Me2GSiO) depending on the type of basic formula of
the siloxanes utilized as outlined in formulas (1) to
,,
(4) aboveO In addition, the siloxane portlon of the
siloxane-oxyalkylene co@olymer must contain from 0-7
(MezSiO) units and from 1-5 (MeGSiO) when the formula ~ ;
is that of (4) aboveO ;~ -
When the basic formula is (2) above, the
,: .,
(Me2SiO) units are 0-7 and khe (MeGSiO) units are
, ~ ::, :~
0-4 and when formula (1) is used, the (Me2SiO) units
are 0-7 and the (MeGSiO) units are 0.
_12-
.
. ,
-
. ., , . , ~
'~' ' .
' , , :': ' `:
3L~ 4~ :
`. -. , .-
~,. When the basic formula is ~3) above, the
`;`~ (Me2SiO~ un.its are 0-2 and the (MeGSiO) units are 1-5.
~ This automatically allows a molecular wei.ght range
:. for the basic siloxanes of this invention to be
.:~. (1) from 148 to 2340;
. ,.~,". : .
.. `. (2) from 134 to 952; ~.
~ : (3) from 221 to 2176 and
.. `~ (4) from 221 to 990. . ~.
In most cases, the preferred molecular weight
~. 10 range of the siloxanes is from 221 to 1000.
-............. The siloxane portion of the siloxane- .: oxyalkylene copolymer is represented by the four
following formulae which are siloxane precursors. ~ ~
(1) Ra~(OSiMez)eOSiMezZ}~_a - -
(2) ZMe2si(oslMe2)f(osiMez)bosiMe2z -~
(3) RaSi{(OSiMe2)g(0S~iMeZ¦cOSiMe9~}4 a
; (4) Me3Si(OSiMe2)h(0SiMeZ)dOSiMe3
~, e,.a, f, b~ g, c, h, d all have the
meanings define~ above and Z represents the appropriate
. 20 reactive group including -OR~', OC~ R~', H3 X, where
X-is chlorine, bromine or ~luorine;
.l OH, -(CHa)30CHzC~-CH2J alkylhalide such as ,(~Hz)3Cl, :
:,x ;, ~ ~
i:~'3 alkyl hydroxide such as -CHzCH20H and alkyl mercaptan .
uch as -(CHz)3SHo ~ ;~
. Any of the siloxanes or mixtures of the :~
,:: ".~
~:~.:; siloxanes containing the same reactive group can be ~::
,:..s.~
::~ utilized, which give rise to a copolymer when reacted
.. ~ 30 with the appropriate glycol.
" ,.,'.",~ , '
.....
,.. ..... .
. ,;,........... .
i.: .. ~ ;
:: .~,,
,:: :.
.... .. . . .. .
~6~49
-.
The siloxanes can be prepared in a number
of ways but the preferred method is to hydrolyze the
appr~priate silanes as for ins-tance in (1) above, a
mixture of silanes such as RaSiX4-a with dimethyldichloro-
silane, dimethylmonochlorosilane and thereafter equil-
ibrating the cohydrolyzate with an acid catalyst such :;
as H2S04. (2) is prepared by cohydrolyzing the silanes
in proportion of f moles of dimethyldichlorosilane, two
mols of dimethylm~nochlorosilane, and b mols of methyl-
dichlorosilaneO Once again the hydrolyzate is H2SO4 `~
equilibrated. (~) is prepared by cohydrolyzing one mol ;
: ,:,
,J , of silane of the formula ~aSiX4-a with _ mols of
~ dimethyldichl~rosilane~ c mols of methyldichlorosiIane
- and at least 4~a mols of trimethylchlorosilane and
~I thereafter e~uilibrating with H2S~4o (4) is prepared
by cohydrolyzing the silanes in the~pr~portion of h ~;
mols of dimethyldichlorosilane, two mols of trimethyl-
monochlorasilane an~ d m~ls of methyldichlorosilaneO
The cohydrolyzate is equilibrated with H2SO40 It is t~
2~ be understood that if the resulting cohydrolyzates have
m~lecular weights in excess of those within the scope
of this inventi~n, the cohydrolyzates can be distilled
t0 give the specific c~mpounds or average structures
antici~ated by the claims 0f this inventionO In each
case ab~ve, R and X are the same as defined ab~ve.
} Another method of preparing the siloxanes is
to equilibrate siloxanes that have already been hydrolyzed.
Such a method f0r instance would involve the equilibration
at tem~eratures (usually in excess of 50C), a mixture of
~0 units of (Me2SiQ) in the form of octamethylcyclotetra- ~
.,:
-14-
s~ ~ , .. .... .
~' :,, , , - : "
4~g
siloxane, b units o~ (MeZS10) in the form of (MéZSiO)4
and 1 unit o~` (ZMe2Si)z0 (i:~` applicable) in the ;~
presence of an equllibrating catalyst. Such equili- ;
brating catalysts are known in the ar-t and consist of ~. :
acid clays~ acid treated melamine type resins and
fluorinated alkanes with sulfonic acid groups~ For
those unfamiliar with such preparations, they can be
found in detail in United Sta-tes Patent 3,4~2,192~
Because of the desirable low m~lecular weight - ~::
of the siloxanes in this inventiong it is within the .
scope of the invention to use siloxanes which have been .
~ prepared by re-equilibrati~n from higher molecular weight
.~ siloxanes of the same general formulae as set out aboveO
The glycol portion of the siloxane oxyalkylene
copolymer must be predominantly poly~ropyleneO It is
to be understood that the glycol portion must contain ~.
less than 35 weight percent of oxyethylene or oxybuty-
lene if they are used at allO The ~referred glycol is ~;
100 ~ercent propylene glycolO The molecular weight of
the glycol ~or-tion is 103-500 grams/moleO The ~referred
range is 150-350 grams/moleO
The glycols useful in the siloxane-oxyalkylene
copolymer can be copolymers of pro~ylene oxide and -.
oxides sele~Gted from a group consisting of ethylene and
butylene oxides wherein the amount of ethylene or :~ ~
butylene radicals is less than 35 weight percent of ;
~ the total alkylene oxide in the copolymerO When ~.
siloxane-oxya].kylene copolymers are desired that contain .
the ~Si-D- linking grou~, the polyalkylene glyCQl should ~:
contain a monoalkenyl ether endblock~ The monoalkenyl .
-15-
;
: , : .
: , . , . ., , ,,, ,:, : , ,
64~
ether endb]ocked p~lyal~ylene gLycols can be copo].ymers
of propylene oxide and ethylene oxide or copolymers of
propylene oxide and butylene oxide or can be copolymers
of all three oxides provided the total ethylene and :~:
bu-tylene oxides, either singly or combined, do not
exceed 35 weight percent of the total alkylene oxide
: of the polyalkyleneoxide glycolO In addition~ the
~ ends of the polyglycol chain not attached to the siloxane
! moiety have a group A wherein A is defined above
10 These glycol copolymers can be linear or
branched and the molecular weight of the glycols is ~ . ;
103-500. The preferred range is 150-350
One method of preparing the glycol copolymers -.
.~ is to dissolve sodium metal in the appropriate alcohol,
; i.e. allyl alcohol or ethanol, in a mole ratio of one
to one and reacting the resulting product with the ;~.
appropriate alkylene oxides at elevated temperatures
and under pressureO The resulting product, after `~.
purification by removal of low boilers, is then capped
with the appr~priate group A
The siloxane-oxyalkylene copolymer is then
prepared by reacting the appropriate siloxane precursor r
and the appropriate polyglycol at elevated temperaturesO ~ .;;
The siloxane-oxyalkylene copolymer is ~.
prepared by reacting a monoalkylene ether, preferably . ~ :
the allyl ether, of the desired polyalkylene glycol
with a siloxane conta:ining SiH groupO When siloxane- .
oxyalkylene co~olymers are used that contain the Si-0-C
bonded copolymer, io eO where the linking radical is -0-D, -
the preferred method of preparing the siloxane-oxyalkylene
-16~ -
,, .
,
4~
copolymer îs by reacting the correspondlng alkoxy functional
siloxane with the appropriate glycol~, i.e.
_SiOQ ~ HOC_ ~ SiO~ ~ QOFf
; ~ in -this instance is a hydrocarbon radical
.~-~' .
free of aliphatic unsaturation and containing 1-10
,,
carbon atoms.
When the siloxane-oxyalkylene copolymer
:.
~ contains a sulfur atom, the preferred method is to
:, ::,:
~; react a siloxane, which contains the mercaptan group,
with a monoalkylene ether, preferably the allyl ether
of the desired polyalkylene glycol using a free radical
type of catalyst such as ultraviolet light or azobisiso-
~` butyrolnitrile
me first of these preferred methods is the
reaction of an allyl ether endblocked glycol with SiH
containing siloxanesO The reaction is carried out by
, ~
heating a mixture of the two reactants in the presence
~-, of a pIatinum catalyst such as chloropla-tinic acid
dissolved in a small amount of isopropyl alcohol, at
:... .,
~ 20 temperatures of from 100-200C.
;~s The second reaction is carried out by combining
j~ the reactants and heating in a solvent solution at reflux
,::"~.. , ~,
! temperatures The preferred solvent is xylene. The
. presence of a catalytic amount of concentrated hydro-
::.
chloric acid facilitates the reaction. ~;~
~ The third type of reaction is carried out by
.~ combining the reactants, heating to the decomposition
.~ temperature of the catalyst and allowing the reaction
: .
~.~ to proceed for 1-3 hours. A sample of the material is
: ~,
then titrated to determine the amount of mercaptan that
: ,' ~' ': ,
":
-17-
:'
: ,:
: ~ "
, '' ,, ~ ,:
.
~ ~46~9
has reacted The normal reactants would be a mercapto
containing siloxane and an alLyl ether endblocked glycol
as in -the first method above.
The siloxane-oxyalkylene copolymer is then
~; used neat, or optionally with a glycol diluent~ in the
i:
foam formulation. Such a diluent, for example, can be
., .:
dipropylene glycol.
~` Because of the discovery -that these certain
siloxane-oxyalkylene copolymers, having the specific
,
properties defined above, give superior high resilient
`~ foams, we have advanced the art beyond that which was
-;:::
known concerning high resilience polyurethane foams
;;i Furthermore, we have overcome a prejudice in the art by
.:~ ,;,
our inventionO In United States Patent 3,741,917, the
: . .
inventors describe their invention as a process which ~ i
., ~ .
~ utilizes siloxane-oxyalkylene copolymers. They state,~ ~
..~ .
however, that the glycol portion of the siloxane~
oxyalkylene copolymer must contain at least 35 weight
~ ~ p@rcent of oxyethylene in order ~or suitable foams
': `.- '
-~ 20 to be producedO
We have discovered that suitable foams can
` be produced by utilizing siloxane-oxyalkylene copolymers
as foam stabilizers that contain much less than 35
~; weight percent of oxyethylene~ Moreovér, we have found
;: -. :::
that our siloxane-oxyalkylene copolymer gives more ~
. j: :,: ~
~ consistant foams and further, the foam stabilizer can
.,. . ,,~ . ,
be used in both of the recognized foam systems in use
today,
It is to be understood that the composition
of this invention can contain small amounts of other
:,,:
,:,~,.~ .:.,
i. ~
-18-
~:". :':
, ~:
`~ '', '~, .
, :'':`
/ ~
`~
`.,
. .
," ' . ` ' ' , : ' .
. , : : : ~ :. : .
64~9
ingredien-ts normally founcl in poLyurethane foam systems
such as solvents, flame retardants and low molecular ~
weight siloxane oils. ~`
The following examples are lllustrative only and
should not be construed as limiting the invention.
For those unfamiliar wlth such preparations, they can
be found in detail in UOS. Patent 3,402,192.
The properties taken on the final cured foam
were obtained in the following manner unless otherwise
indicated.
Cell structure is a subjective test and
consists of taking a vertical cut with a band saw
through the standing cured foam while the foam is
still in the mold, observing the cell structure and
counting the number of cells per 2~54 cm A numerical
rating is placed on the cell structure ranging from 1-5
wherein 1 is fine and 5 is coarseO It can also be rated -~
as fine, medium, or coarse wherein 1-2 is fine, ~-4 is
medium and 5+ is coarseO -
The air flow of a small sample cut from the
heart of the foam bun is taken on a standard breath-
ability apparatusO A slice of foam is removed to give
a flat surface from which the foam and mold are subjected
to cutting at 1804 cm. and 20096 cm. from and parallel to
the bottom of the mold~ A 50 o8 cmO square 2.54 cm~ thick `~
slice is cut from the center of this 2054 cm. cross section
The air flow is taken on the apparatus at lo 27 cmO of waterO
The air flow is reported in liters/min and values are taken ;;
on crushed and non-crushed foam samples and reported below ;~
~0 as 00/00 i,e o42/408
~.
-19- ,~.
,
,
'
, ,. , ,: ., . :
", , , , ., .. , . , .. ., ~ ~ , , ,
~ 469L~ ~
In the exampl.e~ and the claims, Me is employed :~
as an abbrevia-tion for the C~.13- radical, IPA is iso- -
propyl alcohol and all viscosities and refractive indices :~
were measured at 25C unless otherwise specified.
Example l
This example illus-trates the preparation c)f
a siloxane precurso:r for the polyurethane foam stabilizer. ..
Into a twelve liter, three-necked flask
equipped with a stirrer, heating apparatus, temperature
controller and a reflux condenser surmounted with a :~
CaCl2 tube, was added 1620 gms of (Me3Si)20, 740 gms of .- ~ .
dimethyl cyclics, 600 gms of a 1QW molecular weight
methylhydrogen fluid and an equilibration catalyst
for the mixtureO The mixture was heated at 65C :~or .; ~ ~.
16 hours and then allowed to coolO It was treated with
NaHC03 to neutralize the catalyst and then it was vacuum ~. ;;
filteredO The resulting fluid was clear and colorless .~ ~
The analytical data showed there was present oO336% of ~.
: SiH which correspon~s to a molecular weight o~ 29705.
. . . ~
. Theoretical was 00338% and 2960 The viscosity was 129 cs
at 25C, refràctive index = 103848 ancl the speci:fic gravlty . ; -~ ~ ?
was o.848. The formula corresponds roughly to the structure :~ -.
. Me3SiO(Me2SiO) l O ~, (MeHSiO) l O OSiMe3 ~ ' '
Example 2
The preparation of a siloxane-oxyalkylene
copolymer use~ul as a f~am stabilizer in this inventionO ~ h.~.:
: , :
Into a l liter, 3-necked glass flask equipped
with a thermometerJ air motor, heating apparatus and a
reflux condenser surmounted by a CaCl2 tube, was placed :.
200 gms of the si.loxane from Example l, 280 gms of
::
-20- .~
64g
MeO(C3H6O)3H and 50 gms of dry xylene. The mixture
was hea~ed to 100C. and 3 ml. of H2PtC16 H2O in solvent
(30 ppm Pt was added). The reaction was refluxed for
6 hrs. at 152C. and a test was run for residual SiH
which indicated a small amount was present. A small
amount of stannous octoate was added to remove the
residual SiH and the mixture was heated for an additional
hourO The fluid was stripped to remoVe low boiling
materials. The material had the general ormula
10Me3SiO(~3e2Sio~l O~MeSiO)l.OSiMe3
(OCH2CH)30CH3 ~-
CH3
Example 3
Evaluation of Bxample 2 material in a foam
system utilizing a commercial foam stabilizer as a
comparison.
This is a polymer in polyol system.
Preparation of a premix:
a) Pluracol 5811 40.0 pts 4080.0 gms
b~ Dow CP47O1260.0 pts 6120.0 gms
..... .
c~ water 2.6 pts 265.2 gms
d) triethylene- 0.04 pts 4.0 gms
diamine .
e) Houdry X-Dm3 0.80 pts 81.6 gms
A grafted polyglycol having a hydroxyl number of 26
MgKOH/gm and a viscosity o 2800 cps at 770F.
. .
Polypropylene glycol triol of 4700 molecular weight
and having 50% Ethylene oxide end blocking.
Isocyanate containing 80/20 toluene diisocyanate and
30polymeric isocyanates
. ;, ~.
-21-
.~' ' '~ ' ": .
: '
,
. . . .
~,, , :
.
~4~
This mixture was mixed for 4 hours to homogenize.
To 103.44 gms of -the ab~ve premix, the following
was added~
f) 10% in Dioctylphthalate
of stannous octoate .03 pts -~
g) WUC-3051-T (isocyanate) 34.2 pts
Larger quantities of the above materials ~
were joined to have enough material to run on a foam ~--
machine, i.e. 517 gms ~f premix and 1.5 gms of f), and ;~
.- .:; ~....
171 gms o~ g).
Running the machine at 12~0 R~PoM~ mix time
20 seconds for the premix and 5 seconds for final mixO ;~
Results ;~
Approx.
Surfactant Conc ~ roup Structure ;` `~
commercial 0.1 pts MeO Si-C ':~ ~
Example 2 0.5 pts MeO Si-O-C i~ - -
Example 2 0.1 pts Me~ Si-O-C `
Cells Air flow Shrink '
i . ., ,~ -
medium 11.89/1~509 none
fine severe ;j i-
, .;: .:,
me~ium 11.3~/127.4 none
Example 4
This example illustrates the preparati~n of
Me3SiO(Me2SiO)1.O(MeSiO)l.~SiMe3 ~ ~
(CH2) 3 :., ~ ~ .
(OCH2CH2CH2)~OCH
to a glass three-necked, round bottomed flask equipped `~
with the equipment as f~und in Example 2, was added
-22- ;
,' .~ :
, ' ~ ''~ '
`:
.:: ~: , . . . . . : "~. - : . .
69L~
296 grams of the siloxane of Example 1. To this was
added 286 grams of CH2=cHcH2~ocH2cH)4ocH3~ The mixture
was heated to 110C. and catalyzed with 0.3 cc of chloro- ~
platinic acid in isopropyl alcohol. The pot exothermed ~ -
to 148C. and when it cooled to 120C., it was heated fOT
4 hours. The product when cooled was clear and dark
amber in color with a slight platinum precipitate.
.. . .
% SiH was found to be 0.011~ or a residual amount. ;
This product was diluted with CP-4701 to give approximately ` --
12.5% of the sur-factant in the glycol. ~hen evaluated as ~ ~ ~
a foam stabilizer, the following properties were found. `
Using the stabilizer at 1.0 pts per hundred gave a foam `
rise of 13.55 cm., cells with a rating of 2. (1 - fine,
; 5 = coarse?, air flow = 0.7/5.6 and there were no voids or ;
.-. ,,
splits. ~ commercial material gave the following properties
at 1.0 pph. Rise = 5 1/4, cells = 1.5, air flow = 21.5/169.9,
no voids and no splits. It is, therefore, observed that the
material of the present invention gives equivalent results.
; :. . , ~;,
20The system used in evaluation was that as shown in Example 3 `~
above.
~ ~ -
Example 5
This example illustrates the preparation of a
siloxane. To a 3-liter, 3-necked round bottomed glass flask,
there was added 1620 gms of (Me3Si)20, 2220 gms of dimethyl-
siloxane cyclics, 600 gms of a trimethylsiloxy-endblocked
methylhydrogen fluid having approximately 1.6% SiH and 4.0 gms
of a sulfonic acid catalyst.
This material was heated for 7-8 hours at
65C. The material was cooled and enough NaHCO3 was
-23-
E~ ~
~6~649
~ ,:
added to neutralize the catalyst. The material was
filtered to give a clear, colorless product. Analysis
gave 0.222% SiH, Calc was 0.225, Viscosity was 2.43 cs
at 25C. Refractive Index was 1.3903 and Specific Cravity
was 0.889.
Example 6
This example represents the preparation of ~-
an Si-C bonded surfactant using the siloxane of ~xample 5.
In a l-liter, 3-necked flask was placed 400 gms
of the siloxane rom Example 5, 257 gms of CH2=CHCH2 -
(OCH2CH)2 20CH3. The mix~ure was heated to 110C. -
CH3
and 0.3 cc platinum catalyst solution was added
: ,~
~3 ppm pt). The mixture exothermed to 147C. and was
heated at 140C. for 1 hour, then 120C. for 3 hours~
The product was filtered and gave a light yellow~ clear -~
solution. The residual SiH was .012%.
The surfactant was diluted to 2.5 weight percent ` -~-
in CP-4701 polyglycol and evaluated in a foam system as
follows.
; A premix was prepared as a polymer in polyol
system. `
~ '
.,; ~ .
; 30
:
24
,. ,~ :
., .
, ., , ~'
3~6~6~
Ingredient A~ount gms Parts
(a) ~(CH3)2NCH2CH2}20 2.l~ o.8
(b) NEM (n-Ethyl morpholine) 24~V 0,8
(c) Triethylenediamine 2~4 oO8
; (d) Distilled wa-ter 84,o 2.~
(e) Niax~ polyol ll-341 18000060,0
(f) Niax~ polyol 34-281 120000 4
light colored~ low viscosity polyols produced ;-
by in-situ polymerization of a vinyl monomer in the presence
of conventional polyols. 11-34 has a viscosity of 1050 cs
at 20C and a hydroxyl number o-f 3205 to 3505 mg. KOH/gm,
Nia~3 polyol 34-2B has a viscosity of 2550 cps at 25C by
a Brookfield viscometer.
This material was mixed on a roller for four ; ;~
hours to assure complete dispersion of' the ingredients.
~o the premix was added the following for every -
103.76 gms of premix- ` -
(a) surfactant
-, -
(b) 003 gm dibutyltindilaurate, mixed thoroughly
and added
(c) 3402 gms of isocyanate blend composed of
80 parts of 80/20 toluene diisocyanate and
20 parts of polymethylene polyphenylisocyanatso
Carried out the additions in the following manner:
(1) Added the surfactant and the tin catalyst to ~
; the premix; I ;
(2) Mixed at 750 rO pom~ for 20 seconds using
a commercial mixer;
(3) Added the isocyanate
(4) Mixed at 1250 rOp.mO for 4 seconds;
,, ::',
-25- -
'
'
:,
.: . ., :. .
~64649 ~
.
(5) Poured into a container (mold) and allowed
to rise; -~ -
(6) After full rise, postcured for 15 minutes
at 107C., if desired; ;~
(7) Cut foam sample and allow to cool to measure
shrink tendency and air flow.
Using the above method, the following results ` -
were obtained using the material from the above example
as the foam stabilizer.
At 1.0 pph surfactant: rise - 5 1/2; cells = 1.5; ;
air flow = 15.86/172.8; NO splits or voids; NO shrinkage~
Example 7
Three surfactants within the scope of this
invention and having the following formulas, were tested
in the polymer in polyol system for effectiveness, s
~1) Me3sio(Me2sio)3(Melslo)2siMe3
(2) Me3SiO(Me2SiO)3(MeSiO)lSiMe3 ~ ;
G
(3) Me3SiO(~e2SiO)l(MeSiO)
G
All surfactants were diluted to 7.5 welght % in CP-4701
In all cases, G was
. . . :,
-(CH2)3(OCH2CH)2 2OCH3. -~
CH3 --~
The following formulation for the foam was used.
(~) 60 parts CP-4701 (primary hydroxyl Dow)
(b) 40 parts Pluracol 581 (Wyandotte Chem.)l .
(c) .08 parts (CH3)2NCH2cH2OcH2cH2N(cH3)2
(d) .8 parts N-ethyl morpholine
(e) .08 parts Triethylenediamine ~` `
(f) 2.8 parts ~ater
See Example 3
B~ -26-
,
. ~ ., -, ,
1g~6~6~
To the premix was added surfactant and
(g~ .o3 parts Dibutyltindilaurate i~
(h) 34.2 parts Isocyanate blend as in the previous
example
Procedure:
(1) Mix in (g) and the surfactant at 750 r,pOm. for
20 seconds; i~
(2) Add isocyanate and mix at 1250 r.p.m. for 4 seconds;
(3) Pour and allow 3 minutes before postcuring f~r
15 minutes at 107C;
(4) Cool and cut. `
The results~
Surfactant Commercial NoO 1 No. 2 No. 3
surf,
~ph surfactant 1~0 loO 1~0 1~0
Foam rise 12.38 cm. 14~29 cmO 13097 cm. 12~7 cm.
Cell size 105 loO 105 2~0
Shrinkage None Slight None N~ne -~
Voi~s None None None Slight i-~
Air fl~w ;~
lit./min at ``~
27 cm. HzO `~
Noncrushed/ 10. 2/104~8 3~96/73~6 10~ 2/102 21~5/215
Crushed
Example 8 `~
The three surfactants of the ab~ve example ~-
. .... . . ~ .
were evaluated in a hetr~ ~olyol system.
The fQrmulati~n for the f~am was: ~
",'' ' ''~:
, .
,, I
1~646~
.~ Premix
! (a) 96 parts CP 470
(b) .o8 parts (CH3)2NCH2CH20CH2CH2N(CH3)z ~:
(C) J8 parts N-ethyl m~rpholine
~ o8 par-ts Triethylenediamine
(e) 2.8 parts Water
~f) 4.0 parts Pluracol 3552 (453 hydroxy No.)
To the premix add surfactant and .
(g) .03 parts Dibutyltindilaurate
(h) 35.0 parts Isocyanate blend from Example 6.
. 10 lSee Example 3. : ~:
polyglycol obtainable from Wyandotte Chemical,
. Wyandotte, MichiganO ~:.
Procedure: Essentiall.y the same as Example 7.
The results
.~ Surfactant No. 1 No. 2 No. 3
pph surfactant lo O 1~ 0 1~ 0
cell size loO 1~O ls5
,
shrinkage severe slight none
: air flow- 56.64 90.6
~: 2~ crushed -~
~1: ? `~
voids none none none
.
.
: .
~; : .
, 30 :
~,
~ -28-
"
.,
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