The invention disclosed herein deals with acyloxy endblocked polyethers having improved hydrolytic stability. This invention also deals with polysiloxane-polyoxyalkylene copolymers having improved hydrolytic stability and, with compositions which include the polysiloxane-polyoxyalkylene copolymers in the presence of water, and to methods for use of the polysiloxane-polyoxyalkylene copolymers to prepare polyurethane foams.

This invention deals with acyloxy endblocked polyethers having improved 
hydrolytic stability. This invention also deals with 
polysiloxane-polyoxyalkylene copolymers having improved hydrolytic 
stability and, with compositions which include the 
polysiloxane-polyoxyalkylene copolymers in the presence of water, and to 
methods for use of the polysiloxane-polyoxyalkylene copolymers to prepare 
polyurethane foams. 
BACKGROUND OF THE INVENTION 
The polyethers disclosed in this invention are comprised of ethylene oxide 
and propylene oxide components which are endblocked with an acyloxy group. 
Typically, the precursors to such materials are hydroxy endblocked by 
virtue of the process by which they are manufactured. In many applications 
for these materials, the carbinol functionality at the ends of the polymer 
chains are required to be capped in order to reduce the reactivity of the 
polymers in certain reactive systems. Many of these materials are capped 
with ether groups, such as methyl ether; isocyanates, such as toluene 
monoisocyanate; acyloxy groups, such as acetoxy, and the like. 
The prior art, especially in the castable polyurethane resin, and 
polyurethane foam art, is replete with examples of these materials that 
are in the form of polysiloxane-polyoxyalkylene copolymers. The methods 
and materials used in capping the various polysiloxane-polyoxyalkylene 
copolymers are known as well. 
In the polyurethane foam art, there is a special problem associated with 
the use of polyethylene-polypropylene copolymers as the organic segment of 
the polysiloxane-polyoxyalkylene copolymers. The usual procedures for 
manufacturing such materials results in a molecule in which one end of the 
polyoxyalkylene is capped with an unsaturated group such as vinyloxy or 
allyloxy in order to be able to react with methylhydrogenpolysiloxanes to 
create the polysiloxane-polyoxyalkylene copolymers. This is possible 
through hydrosilylation using noble metal catalysts, wherein the 
polysiloxanes have a certain number of methylhydrogensiloxane units in 
their molecules that react with the unsaturated groups of the 
polyoxyalkylenes to form Si--C bonds. Generally, the polyoxyalkylene 
copolymers can be capped before the hydrosilylation, or they can be capped 
after the hydrosilylation. Whatever the case, the normal preparative 
method for the unsaturated polyoxyalkylene copolymers is to coreact, for 
example, allyl alcohol with ethylene oxide and then react this polymer 
with propylene oxide such that the polyoxyalkylene copolymer molecule ends 
up with primarily secondary alcohol groups at its non-unsaturated end. In 
other methods, a random copolymer can be formed by reacting ethylene 
oxide, propylene oxide and allyl alcohol to provide a material having 
large numbers of carbinols on the secondary carbon atoms of the propylene 
glycol that is formed. Thus, one ends up with a molecule having the 
general formula: 
##STR1## 
wherein the majority of the carbinols on the molecule are attached to the 
secondary carbon atoms. So that the polyoxyalkylene materials could be 
reacted into polysiloxanes, and eventually participate in, for example, 
polyurethane foam production as surfactants, the carbinols are quite often 
endblocked as was indicated supra. A common endblocker used is acyloxy. 
The acyloxy endblocked materials have been used for over twenty years in 
aqueous systems in spite of the fact that they are susceptible to 
hydrolytic degradation. Thus, even though the problem was not overly 
severe, it still remained a problem. Materials made this way and stored in 
environments wherein even minute amounts, e.g. 100 ppm water is also 
present, tended to be unstable on the shelf and hence, could not be stored 
with any expectation that the materials would remain stable. 
It was unexpectedly found by the inventor herein that when the 
polyoxyalkylene random copolymer was prepared so that a significant number 
of the carbinols are attached to primary carbon atoms, i.e. primarily on 
the oxyethylene segments of the copolymer, and then endcapped with acyloxy 
groups, a hydrolytically stable copolymer could be made. Such a material 
can be made by providing a random polyoxyalkylene copolymer, and then 
reacting it further with additional ethylene oxide or ethylene glycol to 
cap the polymer with primary carbinols, i.e. "enriched" random copolymers 
with ethylene oxide bound carbinols. 
Further, when the polyoxyalkylene copolymers of this invention were used to 
prepare polysiloxane-polyoxyalkylene copolymers, this benefit was imparted 
to such materials, even when they were stored over long periods of time 
and at elevated temperatures as evidenced by the accelerated data provided 
in the examples. 
PRIOR ART 
The inventor herein believes that no such materials have been made 
available prior to the disclosure herein. However, there is disclosed in 
U.S. Pat. No. 4,042,643, issued Aug. 16, 1977 to Creasey, et al, a 
polysiloxane-polyoxyalkylene copolymer having the following formula: 
EQU (CH.sub.3).sub.3 SiO{SiO(CH.sub.3).sub.2 }.sub.73 {SiO(CH.sub.3)R}.sub.25 
Si(CH.sub.3).sub.3 
wherein R is --(CH.sub.2).sub.3 O{CH.sub.2 (CH.sub.3)CHO}.sub.3 CH.sub.2 
CH.sub.2 OCH.sub.3. This material does not anticipate nor make obvious the 
materials of the instant invention because of the fact that the material 
is a block copolymer and, also, the primary carbinol is ether capped, not 
acyloxy capped, and it was found that these materials do not work very 
well in the end use applications of this invention. 
A further disclosure is made in U.S. Pat. No. 4,614,675, issued on Sep. 30, 
1986 to Ona, et al, wherein at the middle of the page bridging columns 5 
and 6, second formula, there is shown an acetoxy endblocked material which 
is an ethoxy endblocked polydimethylsiloxane bearing trimethylsiloxyethane 
pendant groups, and a separate pendant group which is illustrated as 
CH.sub.3 CO.sub.2 (EO).sub.30 (PO).sub.30 (CH.sub.2).sub.3 --. The 
inventor herein suggests that this material was never prepared, nor was it 
in hand, and that the disclosure of the specific arrangement of the 
acetoxy group on the ethylene oxide segment was merely a result of the 
arrangment of the chemical formulae on the paper. The inventor herein 
believes that this illustration is based on an alphabetized scheme moving 
from left to right on the paper and does not teach a random (EO)(PO) 
(ethylene oxide-propylene oxide) copolymer enriched with terminal ethylene 
oxide carbinols. In support of this proposition, reference is made to 
column 4 of the same patent, lines 44 et seq. in which the patentees 
clearly spell out that the polymers of their invention are --R'O(C.sub.2 
H.sub.4 O).sub.d (C.sub.3 H.sub.6 O).sub.c R" (cf. line 49), and in 
addition, all of the other (EO)(PO) copolymers that are disclosed therein 
are shown as having the capping groups on the propylene oxide, not on 
ethylene oxide. 
THE INVENTION 
Thus, what is disclosed and claimed herein as the invention are acyloxy 
endblocked polyether random copolymers having improved hydrolytic 
stability; polysiloxane-polyoxyalkylene copolymers prepared from the 
polyethers and also having improved hydrolytic stability; compositions 
which comprise such polysiloxane-polyoxyalkylene copolymers in the 
presence of water, and methods of preparing polyurethane foams using the 
polysiloxane-polyoxyalkylene copolymers as surfactants. 
More specifically, this invention deals with a polyoxyalkylene random 
copolymer comprising polyoxyethylene units and polyoxypropylene units and 
having the general formula 
EQU CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 CH.sub.2 
O).sub.w (C.dbd.O)R" 
wherein R" is selected from a group consisting of alkyl radicals having 
from 1 to 6 carbon atoms, z has a value of 1 to 50, and w has a value of 1 
to 50; wherein the ratio of z to w is in the range of 0.1 to 10:1, there 
being at least 40 mole percent of the molecules having --(C.dbd.O)R" 
bonded directly to primary carbon atoms in the polyoxyethylene units in 
the molecule. 
This invention further deals with polysiloxane-polyoxyalkylene copolymers 
selected from polysiloxane-polyoxyalkylene copolymers having the following 
general formula 
##STR2## 
wherein R is --(C.sub.n H.sub.2n)O{CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 
CH.sub.2 O).sub.w (C.dbd.O)R", wherein R" is selected from a group 
consisting of alkyl radicals having from 1 to 6 carbon atoms, n has a 
value of 2 to 8, x has a value of 1 to 500, y has a value of 1 to 500, z 
has a value of 1 to 50, and, w has a value of 1 to 50; wherein the ratio 
of x to y is in the range of 0.1 to 10:1, and the ratio of z to w is in 
the range of 0.1 to 10:1, there being at least 40 mole percent of the 
molecules having --(C.dbd.O)R" bonded directly to primary carbon atoms in 
the polyoxyethylene units in the molecule. 
Still further, this invention deals with a process of preparing 
polyurethane foams said method comprising: (I) mixing a formulation 
comprising: (a) at least one reactive diisocyanate; (b) at least one 
reactive polyol; (c) at least one catalyst; (d) an organic blowing agent, 
and (e) a polysiloxane-polyoxyalkylene copolymer selected from the group 
having the following general formula (i) (CH.sub.3).sub.3 
SiO{SiO(CH.sub.3).sub.2 }.sub.x --{SiO(CH.sub.3)R}.sub.y 
Si(CH.sub.3).sub.3 and (ii) (CH.sub.3).sub.3 SiO{SiO(CH.sub.3)R}.sub.y 
Si(CH.sub.3).sub.3 wherein R is a random copolymer comprising 
polyoxyethylene units and polyoxypropylene units and having the general 
formula 
EQU --(C.sub.n H.sub.2n)O{CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 CH.sub.2 
O).sub.w (C.dbd.O)R" 
wherein R" is selected from a group consisting of alkyl radicals having 
from 1 to 6 carbon atoms, n has a value of 2 to 8, x has a value of 1 to 
500, y has a value of 1 to 500, z has a value of 1 to 50, and w has a 
value of 1 to 50; wherein the ratio of x to y is in the range of 0.1 to 
10:1 and the ratio of z to w is in the range of 0.1 to 10:1, there being 
at least 40 mole percent of the molecules having --(C.dbd.O)R" bonded 
directly to primary carbon atoms in the polyoxyethylene units in the 
molecule; (II) allowing the mixture to react and cure whereby a 
polyurethane foam is obtained. 
This invention also deals with a second process for producing polyurethane 
foams, said process comprising: (I) mixing a formulation comprising: (a) 
at least one reactive diisocyanate; (b) at least one reactive polyol; (c) 
at least one catalyst; (d) water, and (e) a polysiloxane-polyoxyalkylene 
copolymer selected from the group having the following general formula (i) 
##STR3## 
wherein R is a random copolymer comprising polyoxyethylene units and 
polyoxypropylene units and having the general formula 
EQU --(C.sub.n H.sub.2n)O{CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 CH.sub.2 
O).sub.w (C.dbd.O)R", 
wherein R" is selected from a group consisting of alkyl radicals having 
from 1 to 6 carbon atoms, n has a value of 2 to 8, x has a value of 1 to 
500, y has a value of 1 to 500, z has a value of 1 to 50, and w has a 
value of 1 to 50; wherein the ratio of x to y is in the range of 0.1 to 
10:1 and the ratio of z to w is in the range of 0.1 to 10:1, there being 
at least 40 mole percent of the molecules having --(C.dbd.O)R" bonded 
directly to primary carbon atoms in the polyoxyethylene units in the 
molecule; (II) allowing the mixture to react and cure whereby a 
polyurethane foam is obtained. 
This invention deals with yet another process for preparing polyurethane 
foams, the process comprising: (I) mixing a formulation comprising: (a) at 
least one reactive diisocyanate; (b) at least one reactive polyol; (c) at 
least one catalyst; (d) an organic blowing agent; (e) water, and (f) a 
polysiloxane-polyoxyalkylene copolymer selected from the group having the 
following general formula (i) (CH.sub.3).sub.3 SiO--{SiO(CH.sub.3).sub.2 
}.sub.x {SiO(CH.sub.3)R}.sub.y Si(CH.sub.3).sub.3 and (ii) 
(CH.sub.3).sub.3 SiO--{SiO(CH.sub.3)R}.sub.y Si(CH.sub.3).sub.3 wherein R 
is a random copolymer comprising polyoxyethylene units and 
polyoxypropylene units and having the general formula --(C.sub.n 
H.sub.2n)O{CH.sub.2 (CH.sub.3)CHO}.sub.z-- --(CH.sub.2 CH.sub.2 O).sub.w 
(C.dbd.O)R", wherein R" is selected from a group consisting of alkyl 
radicals having from 1 to 6 carbon atoms n has a value of 2 to 8, x has a 
value of 1 to 500, y has a value of 1 to 500, z has a value of 1 to 50, 
and w has a value of 1 to 50; wherein the ratio of x to y is in the range 
of 0.1 to 10:1 and the ratio of z to w is in the range of 0.1 to 10:1, 
there being at least 40 mole percent of the molecules having --(C.dbd.O)R" 
bonded directly to primary carbon atoms in the polyoxyethylene units in 
the molecule; (II) allowing the mixture to react and cure whereby a 
polyurethane foam is obtained. 
This invention also deals with a hydrolytically stable composition 
comprising: (A) water, and (B) a polysiloxane-polyoxyalkylene copolymer 
selected from polysiloxane-polyoxyalkylenes copolymers having the 
following general formula 
##STR4## 
wherein R is a random copolymer comprising polyoxyethylene units and 
polyoxypropylene units and having the general formula 
EQU --(C.sub.n H.sub.2n)O{CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 CH.sub.2 
O).sub.w (C.dbd.O)R", 
wherein R" is selected from a group consisting of alkyl radicals having 
from 1 to 6 carbon atoms, n has a value of 2 to 8, x has a value of 1 to 
500, y has a value of 1 to 500, z has a value of 1 to 50, and w has a 
value of 1 to 50; wherein the ratio of x to y is in the range of 0.1 to 
10:1 and the ratio of z to w is in the range of 0.1 to 10:1, there being 
at least 40 mole percent of the molecules having --(C.dbd.O)R" bonded 
directly to primary carbon atoms in the polyoxyethylene units in the 
molecule.

DETAILED DESCRIPTION OF THE INVENTION 
One aspect of this invention are the polyoxyalkylene random copolymers 
having the general formula 
EQU CH.sub.2 .dbd.CHCH.sub.2 O{CH.sub.2 (CH.sub.3)CHO}.sub.z (CH.sub.2 CH.sub.2 
O).sub.w (C.dbd.O)R". 
The polyoxyalkylene copolymers must be random in structure as it relates to 
the components --(CH.sub.2 CH.sub.2 O)--, and --{CH.sub.2 
(CH.sub.3)CHO}--, as it has been reported to the inventor herein that 
block copolymers will not give the benefits in the end use application. As 
indicated above, one end of the molecules of this polyoxyalkylene 
copolymer is capped with an unsaturated moiety, such as vinyloxy or 
allyloxy, allyloxy being preferred. The other end of the molecule contains 
a polyoxyalkylene segment which is capped with a carbinol, and without 
this invention, the amount of polyoxyalkylene end groups that contain 
primary carbinols is limited to generally less than about 10 mole percent. 
The polyoxyalkylene random copolymers of this invention have a average 
molecular weight of about 160 to 4130 g/mole. 
It should be understood by those skilled in the art that the number of 
primary hydroxyl groups present in the random copolymer must be such that 
at least 40 mole percent of the molecules have carbinols bonded directly 
to primary carbon atoms in the polyoxyethylene units in the molecule. 
The majority of the primary hydroxyl groups are those derived from the 
ethylene oxide residues but certain of the hydroxyl groups derived from 
propylene oxide can also be primary depending upon the manner in which the 
oxirane ring of the propylene oxide opens up in the formation of the 
copolymer. In this invention, the polyoxyalkylene random copolymer which 
is "enriched", contains at least forty mole percent of end groups having 
primary carbinols before it is endcapped. The primary carbinols are 
reacted with various acylates in order to cap the carbinols with an 
acyloxy group. For purposes of this invention, the formula, R" is the 
alkyl radical of an acyloxy endblocking or endcapping material and these 
materials are selected from a group consisting of alkyl radicals having 
from 1 to 6 carbon atoms. Preferred for this invention are the methyl, 
ethyl, propyl and butyl radicals. Most preferred is the methyl radical. 
The molecular weight of the polyoxyalkylene random copolymer is made up 
primarily of the ethylene oxide and the propylene segments, and such 
molecular weight is indicated by the subscripts w and z, respectively. The 
subscript z has a value of 1 to 50, and w has a value of 1 to 50; wherein 
the ratio of z to w is in the range of 0.1 to 10:1. Such copolymers 
include for example: CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CHCH.sub.3 
O).sub.18 (CH.sub.2 CH.sub.2 O).sub.18 C(O)CH.sub.3, and the like. 
As indicated above, this invention also deals with 
polysiloxane-polyoxyalkylene copolymers, which are prepared by utilizing 
the polyoxyalkylene random copolymers described above. The materials are 
prepared by the well-known hydrosilylation in which the polysiloxanes 
containing hydrogen attached to silicon atoms, for example, 
(CH.sub.3).sub.3 SiO{SiO(CH.sub.3)H}.sub.1 Si(CH.sub.3).sub.3 ; 
(CH.sub.3).sub.3 SiO{SiO(CH.sub.3).sub.2 }.sub.1 --{SiO(CH.sub.3)H}.sub.1 
Si(CH.sub.3).sub.3 ; (CH.sub.3).sub.3 SiO{SiO(CH.sub.3).sub.2 
}3.7{SiO(CH.sub.3)H}.sub.9.5 --Si(CH.sub.3).sub.3 ; (CH.sub.3).sub.3 
SiO{SiO(CH.sub.3).sub.2 }.sub.1.9 {SiO(CH.sub.3)H}.sub.13.3 
Si(CH.sub.3).sub.3 ; (CH.sub.3).sub.3 SiO{SiO(CH.sub.3).sub.2 }.sub.2.1 
{SiO(CH.sub.3)H}.sub.22.8 Si(CH.sub.3).sub.3 ; (CH.sub.3).sub.3 
SiO--{SiO(CH.sub.3).sub.2 }.sub.3.3 {SiO(CH.sub.3)H}.sub.73 
Si(CH.sub.3).sub.3 ; (CH.sub.3).sub.3 SiO{SiO(CH.sub.3).sub.2 }.sub.8.0 
--{SiO(CH.sub.3)H}.sub.87 Si(CH.sub.3).sub.3, and (CH.sub.3).sub.3 
SiO{SiO(CH.sub.3).sub.2 }.sub.19 -{SiO(CH.sub.3)H}.sub.139 
Si(CH.sub.3).sub.3, are used herein. The silicon bound hydrogen is reacted 
with the unsaturated terminal of the polyoxyalkylene random copolymers 
under the catalytic influence of platinum, rhodium, or the like. These 
reactions are well known in the art and a detailed description of the 
reaction will not be set forth herein. 
The polysiloxane portion of the copolymer is comprised of trialkylsilyl 
endblocking units, and for purposes of this invention, the body of the 
siloxane chain is comprised of polydimethylsiloxane units and 
methylhydrogenpolysiloxane units having the general formula: 
##STR5## 
wherein x has an average value of 1 to 500, and y has an average value of 
1 to 500. Further, the ratio of x to y is in the range of 0.1 to 10:1. 
The polyxiloxane-polyoxyalkylene copolymers are useful as surfactants in 
the preparation of polyurethane foams. 
COPOLYMER SURFACTANTS 
All of the surfactants used in the examples were prepared by 
hydrosilylation of the allyloxy, or vinyloxy endblocked polyethers, using 
platinum as the catalyst, according to standard procedures known in the 
art. 
EXAMPLE 1 
A set of samples were subjected to an accelerated hydrolysis test to show 
the hydrolytic stability of the materials of this invention. 
A material, CH.sub.2 .dbd.CHCH.sub.2 O(CH.sub.2 CHCH.sub.3 O).sub.18 
(CH.sub.2 CH.sub.2 O).sub.18 C(O)CH.sub.3 was prepared. Samples of this 
material were placed in a 92.degree. C. oven and the acid content was 
measured periodically over a period of time with the following results. 
______________________________________ 
ACID NO. TOTAL 
TIME mg. KOH/ ACID 
Min. gram sample 
ppm 
______________________________________ 
0 .0136 14.5 
17 .0136 14.5 
55 .0194 20.7 
97 .0360 38.5 
120 .0160 17.3 
182 .0564 60.0 
245 .0344 36.8 
328 .0814 86.9 
360 .0702 75.0 
1260 .0570 61.0 
2747 .0496 53.0 
4190 .07197 77.0 
______________________________________ 
These results show that the rate was 11.2 ppm/hr. and it plateaued around 
80 ppm, while a like sample, not falling within the scope of this 
invention had an initial rate of 37 ppm/hr. and a plateau at about 500 
ppm. It was speculated that the erratic acid values were caused by the use 
of glass vials having plastic tops which may have leaked acetic acid 
through the caps as they were heated in this accelerated test. However, 
the data shows the desired trend leading to the conclusions regarding the 
benefits recited herein. 
EXAMPLE 2 
Hydrolysis rates were measured on the material of example 1 and it was 
compared with other similar materials with varying amounts of ethylene 
oxide groups containing acetoxy groups. 
______________________________________ 
HYDROLYSIS 
SAMPLE RATE 
______________________________________ 
A 11.2 ppm/hr. 
B 37.3 ppm/hr. 
C 15.2 ppm/hr. 
D 12.3 ppm/hr. 
______________________________________ 
Sample B is a material of the prior art. Sample A is the inventive material 
of example 1. Sample C is a material of this invention having 80% ethylene 
oxide ends covered with acetoxy groups, and Sample D is a material of this 
invention having 60% ethylene oxides ends covered with acetoxy groups. 
In spite of the fact that the hydrolysis rate does not line up with very 
well with the percentage of ethylene oxide ended polymers, it is clear 
that the hydrolysis rates of the materials of the instant invention are 
lower than those of the prior art material. 
EXAMPLE 3 
Preparation of a flexible polyurethane foam using (CH.sub.3).sub.3 
SiO{(CH.sub.3).sub.2 SiO}.sub.103 (CH.sub.3 RSiO).sub.10 
Si(CH.sub.3).sub.3 wherein R is --(CH.sub.2).sub.3 O(CH.sub.2 CHCH.sub.3 
O).sub.18 (CH.sub.2 CH.sub.2 O).sub.18 C(O)CH.sub.3. 
The polyether was reacted with a polydimethylsiloxane substituted with 
0.117 weight percent hydrogen attached to silicon atoms and having a 
viscosity of 155 centistokes. 
The resulting polysiloxane-polyoxyalkylene copolymer was used in a test for 
flexible polyurethane foam as follows: 
1. 107.8 g of premix consisting of 
4.2 weight percent water 
92.7 weight percent of polyol 235-048, a product of Dow Chemical, Midland 
Mich. 
3.0 weight percent of methylene chloride 
0.1 weight percent of Dabco BL11, an amine catalyst product of Air Products 
& Chemicals. 
2. 0.6 g of the polysiloxane-polyoxyalkylene produced above. 
3. 0.4 g of T-10 catalyst, a tin catalyst product of Air Products & 
Chemicals. 
4. 53.1 g of toluene diisocyanate. 
The components 1 to 4 were thoroughly mixed and a flexible polyurethane 
foam was produced having a foam height of 233.7 mm. The average for 
production lots having the same formulation, but made with acyloxy 
polyethers not of this invention is 233.2 mm. This shows that the ability 
of the surfactant to perform in a polyurethane formulation is essentially 
unaffected.