ESTERS DE L'ACIDE PHOSPHORIQUE

PHOSPHATE ESTERS

Abrégé anglais

-1-
ABSTRACT
Phosphate esters having the formula <IMG>
wherein A has the structural formula
<IMG>
and B has the structural formula
<IMG>
wherein the R groups are alkyl radicals, m and n are
each integers from 0 to 4 and the sum of m + n
is from 1 to about 4, are useful as flame retardants,
especially for rigid polyurethane foams.
-1-

Revendications

-20-
What is claimed is:
1. A phosphate ester having the formula RO[(A)m(B)n]H
wherein A has the structural formula
<IMG>
and B has the structural formula
<IMG>
wherein R,R1 and R2 are the same or different and are linear
or branched primary radicals selected from alkyl having 1
to 6 carbon atoms, and haloalkyl and hydroxyalkyl having 2
to 6 carbon atoms; m and n are integers from 0 to about 4
and the sum of m plus n is from 1 to about 4.
2. The phosphate esters of claim 1 wherein R, R1 and
R2 are the same.
3. The phosphate esters of claim 1 wherein at least
R1 and R2 are substituted with at least one halogen atom.
4. The phosphate esters of claim 1 wherein at least
R1 and R2 are substituted with at least one hydroxyl group.
-20-

-21-
5. The phosphate esters of claim 1 wherein R, R1
and R2 are each selected from the group consisting of methyl,
ethyl, propyl, n-butyl, 2-chloroethyl, hydroxyethyl, hydroxy-
propyl and 2,3-dibromopropyl.
6. A method for preparing the phosphate ester of claim
1 comprising
(a) reacting a polycyclic compound (I) having the
formula (C5H804P2)XuYv, wherein X is bromine
or chlorine, Y is OR3, wherein R3 is an alkyl
group having 1 to 6 carbon atoms or an halo-
alkyl group having 2 to 6 carbon atoms, u and
v are integers with values of 0, 1 or 2, and
the sum of u plus v is 2; with (II) a primary
alcohol of the formula HOQ, wherein Q has the
the meanings of R3 or is a primary hydroxy-
alkyl group having 2 to 6 carbon atoms, in the
presence of (III) C12;
(b) the molar ratio of II to I being equal to from
about (2u + v):l to 10(2u + v):1, said ratio
not exceeding a value of 20, and
(c) the molar ratio of III to I being from 2 to
2.2.
7. The method of claim 6, wherein X is bromine or
chlorine, u 18 2 and v is O and said ratio of II to I equals
4 to 20.
8. The method of claim 7, wherein said ratio of II to
I equals 5 to 12.
9. The method of claim 6, where Y is OR3, u is O and
v is 2, said ratio of II to I being 2 to 20.
-21-

-22-
10. The method of claim 9, wherein said ratio of II
to I is equal to 2 to 7.
11. The method of claim 6, wherein said alcohol (II)
is selected from the group consisting of methanol, ethanol,
n-butanol, 2-chloroethanol, 2,3-dibromopropanol, 2-hydroxy-
ethanol, and 3-hydroxypropanol.
12. The method of claim 7, wherein X is chlorine.
13. The method of claim 6, wherein said compound (I)
has a polycyclic structure selected from the group consist-
ing of
<IMG>
and
<IMG>
wherein the Z's may be the same or different and are select-
ed from the same groups as X and Y.
14. A flame retardant composition comprising an
organic polymer and a flame retarding effective amount of
-22-

-23-
a phosphate ester of the formula RO[(A)m(B)n]H wherein A
has the structure
<IMG>
and B has the structure
<IMG>
wherein R, R1 and R are the same or different and are
linear or branched primary radicals selected from alkyl
having 1 to 6 carbon atoms, and haloalkyl and hydrox-
alkyl having 2 to 6 carbon atoms; m and n are integers
from 0 to about 4 and the sum of m plus n is from 1 to
about 4.
15. The flame retardant composition or claim 14
wherein the organic polymer 18 selected from the group
consisting of polyester and polyurethane polymers.
16. The flame retardant composition of claim 14
wherein R1 and R2 are the same.
17. The flame retardant composition of claim 14
wherein R and R are each selected from the group consisting of
-23-

-24-
methyl, ethyl, propyl, n-butyl, 2-chloroethyl, 2,3-dibromo-
propyl, 2-hydroxyethyl and 3-hydroxypropyl.
18. The flame retardant composition of claim 15
wherein said polymer is a polyurethane polymer.
19. The flame retardant composition of claim 18 where-
in said polyurethane polymer is a rigid polyurethane foam
and said phosphate ester is chemically bound to and an
integral part of the polymer structure.
20. The flame retardant composition of claim 19, where-
in R1 and R2 are the same.
21. The flame retardant composition of claim 19, where-
in at least one of R1 and R2 is substituted with at least
one halogen atom.
22. The flame retardant composition or claim 14, where-
in said phosphate ester 18 present at a concentration of
from 2 to 40 percent by weight based on the total weight of
the polymer.
23. The flame retardant composition Or claim 22 where-
in said concentration is from 5 to 15 percent by weight.
-24-

Description

1056393
--2--
BACKGROUND OF TRE INVENrION
Field_of the Invention
This invention relates to novel phosphate esters
prepared from polycyclic phosphorohalidites. These
esters, which are use~ul as flame retardants especial-
ly ~or rlgid polyurethane ~oam~, have the ~ormula:
RO~(A)m(B)n~H wherein A has the structural formula
~ O
" "
-- P- O - ~c O- PR2Rl
H O O -
_
and B has the structural formula
O -
/ ~ ~--O-P-ORl
_ _ p ~ ~ oR2 _
wherein R~ Rl, and R2 are the sAme or dlfferent and are
alkyl radlcal~, ~nd m and n are integer~ from O to
about 4, the sum of m plu8 n being from one to ~bout
four. It is understood that structures A and B are
randonmly dlstributed within the~e oiigomerlc compounds.
Description of the Prior Art
Bli2nyuk et ~1., Zh. Ob~heh. Khim, 34, p. 1169-
70 (1960), teach react~ng PC13 with an excess o~
alcohol ln the pre~ence of chlorine to produce PO(OR)3.
Frank et al. J. Org. Chem., 31, p. 872-5 (1966),
converted ~lmple trialk~l pho~phltes (RO)3P to the
-2-

3 1056393
corresponding pho~phate~ (RO)3PO in a slmllar fashionl
Neither of the above references however disclose
the conversion of polycycllc phosphorohalidites to the
phosphate esters of thi~ lnvention.
SUMMARY OF THE _NVENTION
It is an ob~ect of thls lnvention to provide
new phosphate esters. It is a ~urther obJect of this
invention to present a process for preparing such
phosphate e~ters. I~'is another ob~ect of thi~ inven-
tion to prepare flame resi~tant polymers with the useof said phosphate esters, and it is still another
ob~ect of this invention to prepare ilame retardant
polyurethane and polyester polymers, e~pecially rlgid
polyurethane foams with the lncluslon thereln o~ the
co-reactive phosphate esters.
~ rDON OF THE PREFERRED EMBODIYENTS
Polycycllc phosphorohalidltes are used for the
preparation of the phosphate ester~ of this lnventlon.
These phosphorohalldites precursor~ have the general
formula tC5H804P2 )XUY~, whereln the substltuent~ X
~nd Y ma~ either be halogen or alkoxy radical~ as
described herelnafter.
The phosphate esters of this invention are
prepared from the above pho~phorohalidites resulting
in the new compounds of the general formula
R *(A)m (B)n-3H~ wherein A has the ~tructural io~mula
--,0, ,0, -- '''
tOR2~ oR2
3 HO O -
, -3-
.. , , . . ~, . .. . . ....

-4- 1056393
and B has the ~tructural formula
L ~~ O ~
whereln R, Rl and R2 may be s~me or different and are
selected from primary alkyl radicals having from 1
to about 6 carbon atoms and haloalkyl or hydroxy-
alkyl radical~ having from 2 to 6 carbon atom~.
These radicals may be elther linear or branched.
Examples of ~uch radlcals, but not ln limitation here-
of, include methyl, ethyl, propyl, n-butyl, lsobutyl,
n-pentyl, 2-methylbutyl, 3-methyl-butyl, neopentyl, n-
hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl,
2-chloroethyl, 2-bromoethyl, 2- or 3-chlorpropyl, 2-
or 3-bromopropyl, 2,3-dlrbomopropyl, 2,3-dichloro-
propyl, 4-chlorobutyl, 5-chloropentyl, 6-chlorohexyl,
2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl,
5-hydroxypentyl and 6-hydroxyhexyl.
The polycycllc phosphorohalldite precur~or~ are
known compounds of the general formula (C5H804P2)~ Yv
whereln X 18 bromine or prefera~ly chlorlne, Y i8 an
oR3 group wherein R3 1B an alkyl or halo~lkyl radlcal
selected ~rom the ~ame groupa QB R above~ but not a
hydroxyalkyl radlcal, u and v each have the values of
0, 1 or 2,and the ~um o~ u plU8 V i8 2. These pre-
cursors may al80 be represented by the structurAl
formulae

1056393
Z-p~ P-Z
and
/ o
~ 2 Z2
which-are isomers and wherein Z ha~ the meanlngs o~
X or Y as defined above. Although the polycylic
precursors wherein the ~ubstituent groups (X) are
halogen are called phosphorohalidltes, and wherein the
substituent gr~ups (Y) are oR3 are usually named
phosphltes, the latter compounds shall be included
under the general term phoRphorohalidites ~or the
purpo~e of this disclosure.
Polycyclic phosphorohalldites may be prepared
from phosphorus trlhalldes such as PC~3 or PBr3 and
and pentaerythrltol according to the method described
by H. J Lucas et al. J.A.C S Vol. 72, p. 491-497 (1950)
The conversion from halogen to oR3 substitution may be
made in accordance with U.S. Patent 2,961,454 (aould et
al.). It has been found that the ~re~hly prepared
spirocyc~ic or blcycllc compound~, ~ith tlme, isomerize
to form an equilibrium mixture containing both
structural isomer~. Either lsomer or a mixture thereo~
i~ sultable ~or the preparation o~ the in~entlve e~ters.
In view of the phosphorohalldites being ~olids they are
conveniently prepared in the presence of an inert
solvent. Subsequent preparation o~ the phosphlte esters
o~ thi~ lnvention may be conveniently carried out using
the phosphorohalidite solution thus obtained wlthout
--5--
.: . . .

-6- ~056393
prior recovery of the precursor. It ls advantageous
to choose a solvent wherein not only the precur~or
but also the ester i6 soluble, thus chlorinated hydro-
carbon~ such as carbon tetrachloride, chloroform,
ethylene dichloride, methylene dlchlorlde, and the
like are especially sultable. The preferred solvent
is ethylene dichloride. Since the spirocycllc pre-
cur~or ls more soluble in the above mentioned solvents,
it i~ the preferred form ~or use herein.
The compounds of this lnvention are prepared
by the addition of a polycyclic phosphorohalldite to
a primary allphatic alcohol ln the presence o~ chlorine.
Sald alcohols have the general formula HOQ, wherein Q
has the same meAnings as R,Rl and R2 defined above.
The use of ~econdary or tertiary alcohol~ for
the making of slmilar products accordlng to the process
of this invention while possible i~ not recommended
because of the tendency of such alcohols to form hypo-
~ halides in the presence o~ C12. Hypohalide~ may de-
compose rapidly, even explosively, at ambient temperatures,
When preparing the esters of thi~ invention the
ratio of alcohol must be controlled within certaln
llmlts in order to prevent undeslrable side reActions.
If the ratio is too low, Arbuzov type re~rrangements
may take place; i~ the ratio is too high, pentaerythrltol
and non-polycyclic or polymeric trlalkyl phosphates are
produced. Therefore, the molar ratlo of HOQ to X plu~ Y
~hould be equal to ~rom (au + ~:1 10(2u+v):1 ~aid ratio
not exceeding a value of 20:1.
If u equals 2 and v equal~ 0, the pre~erred

-7- 1056393
molar ratlo of HOQ to X+Y ha~ a value of ~rom 5 to 15,
most pre~erably from 8 to 12. If u equals 0 and v i6
2, the pre~erred molar ratio range may be from 2 to 7,
the mo~t pre~erred ratio being from 3 to 5. Withln
the~e limlt~, the ratlo o~ the reactant~ may be varied
a~ desired to produce pho~phate esters havlng a wlde
range of hydroxyl number~. For instance, lf X i8 ~-
chlorine, the alcohol iB ethanol and the rQtio i8 15,
ester~ having an OH number of about 190-200 are produced,
while a ratio o~ 8 leads to a product wlth an OH number -
o~ about 110-130. If X is chlorlne, the alcohol iB 2-
chloroethanol~ and the ratlo i8 6, the resultant pro-
duct has an OH number of about 120, while at a ratio o~
5 an OH number o~ about 90 resulte.
While agitating the reaction mixture, the
polyc~cllc pho~phorohalidlte (dlluted wlth an approprl~te~
inert 601vent i~ BO deslred) 1B addod contlnuouBly or ` ;~
incrementably to the alcohol. ~he ~lcohol may option~llg ~
be diluted wlth an inert organlc eolvent in whlch the ~ ;
reactant~ and the reeultant pho~phate esters are ~oluble.
Simultaneouely, but separately ko the ~ddition
of the phosphorohalidite, chlorine i~ charged to the
alcohol. The rate of ~ddition Or the two ingredients
ie maint~lned at a molar ratlo of h~logen to phoephoro-
halldite of at lea~t 2:1. Usually a ~light e~cess Or
halogen is used, preferably not exceeding 10 ~ole p~r-
cent. A convenient way to malntain the proper con-
centr~tlon of chlbrine durihg th~ r~actlon and to en8ure
` tha~ chlorlne 1~ in a sligh~ excesa~ ic Oy monltoring
the potentlaI o~ the reaction medlum wlth ~ standar~
-7-
..;
~, '
,
. .

-8- ~056393
potentiometer fitted with a redox probe con~isting of
a platlnum measuring probe wlth a standard calomel
reference electrode. This operation is carried out by
selecting a potential which is below that ob~erved for
the reaction medium, e.g. the solvent or alcohol or
mixtures thereof saturated with chlorine In the case
of a potentiometer with a scale from zero to 1400 mv,
for example, this operation is carried out at a
potential below 1400 mv, usually in the range from
500 mv to 900 mv. An excess of chlorine may al80 be
followed visually by the appearance of a greenlsh
color in the reaction mass. The reaction iB completed
when, after addition of all of the polycyclic phos-
phorohalldite, the resultlng solution maintalns a
permanent greenish color and no further uptake of
halogen is observed.
Alternatively, when Y is oR3 and v le 2, the
polycycllc startlng material may be dlssolved ln the
alcohol using an appropriate solvent lf de~ired such
as ethylene dlchlorlde, and then sub~equently treated
wlth chlorine until the reaction i8 complete.
The proce~s of thls inventlon i8 exothermlc
and requlres cooling to maintain a temperature of from
about -20C to about 80C, prefersbly 20C to 40C.
~5 Upon the completion of the reactlon~ the
phosphate esters may be recovered by stripplng the 801u-
tion under vacuum at about 30-50C to remove the bulk of
the hydrogen chloride produced durlng the reaction. ~he
solution 1B then neutralized by any conventional method,
such as by the addition of sodium bicarbonate~ aqueous
'' ,''.
- . - - ~ . . - .. .. - . ~ . . . .. . ~ .

9 1056393
sodium or potassium hydroxide, or an alcoholate salt.
Neutralization may also be performed by using an epoxide
such as ethylene or propylene oxlde. Alternatively,
the reaction mixture may first be neutrallzed and then
stripped as described above.
The neutralized mlxture ls then sub~ected to
vacuum distillation to remove any residual solvent or
alcohol as well as any volatile by-product~ such as
haloalkanes or chlorohydrins. The phosphate ester ls
then recovered as the dlstillatlon resldue.
Example I
Preparation of 3,9-Dichloro-2,4,8,10-tetraoxa-3,9-di-
~osphaspl o~ 5~? 5~ unde ane _
This polycycllc phosphorochloridite precursor
is prepared ln the following manner: To a 2-liter, 3-
necked round bottom fla~k equipped with a condenser,
a stirrer, a thermometer, a dropplng funnel and a nitro-
gen inlet tube, is added PC13 (280,0 g, 2.04 moles)
dropwise to a stlrred suspenslon o~ pentaerythrltol
(136.0 g, 1.0 mole) in dichloroethane (240 ml). The
reaction mixture is kept at 35-50C by means Or a water
bath. During the additlon the system iB kept under a
gentle nitrogen sweep to facilitate the removal of the
HCl formed. When the PC13 addition ls completed, the
temperature of the reactlon mixture 18 slowly raised to
reflux o~er about a one hour period. The mlxture 18
then kept under reflux, using a vigorous nitrogen sweep,
until a homogeneous solution is obtained, i.e. about one
to two hours. Trace amounts of white precipitate may ~-
separate from the reaction ~olution upon cooling to room
g_
- , - . . . . . . . .
, . . . . .
-.

1056393
-10-
temperature. This small amount of preclpitate, conæist-
ing mostly of pentaerythritol, is removed by filtration.
The filtrate contains the desired product, 3,9-dlchloro-
2,4,8,10-tetraoxa-3,9-diphosphaspiro~5.5~ undecane,
and is essentially free of by-products. The phosphoro-
chloridite precursor thus obtained is used ln the sub-
sequent reactions without further puri~ication.
Example II
Methyl Phosphate Ester
Thls example repreRents the general procedure
for the preparation of the compounds of this lnvention
by oxidation Or a phosphorochlorldite wlth chlorlne ln
presence of an alcohol.
Methanol (240 g, 7.5 moles) i3 stirred and cool-
ed to 5 to 10C by means of an acetone-lce bath ln a
reaction vessel fltted with a thermometer, an addltlon
funnel, and a gas lnlet tube connected to a chlorlne gas
cylinder. Chlorine (2 moles) and the phosphorochlorldlte
(1 mole~ Or Example I are added slmultaneously to the
methanol malntainlng a sllght chlorlne exce8s, a~
evldenced by the greenl~h color Or the reaction medium.
Durlng the additlon, the reactlon mixture 18 maintalned
at about 25 to 35C by means Or the acetone-lce bath as
well as by controlllng the rates Or addltion o~ the re-
actants. When the addltlon Or pho~phorochloridlte 18
completed, the resultlng greenlsh solutlon i8 distllled
under 10-20 mm Hg pressure at about 30-50C in order to
remove most of the HCl formed durlng the reactlon. The
re~ldual acidic solution i8 then treated with propylene
oxide at 40-60C untll neutral to moist litmus paper.
-10-

-
1056393
Low boiling materials are then f~rther removed from the
reaction solution by distlllation under 10-20 mm. Hg and ~ -
subsequently 0.5 mm. Hg at about 100C. The re~idue ls
the methyl phoæphate ester, a clear fluld oily material.
Analysis: 12.5% P: o.8% Cl; 0H~203
In Examples III to X incluslve, the æpiro-
cyclic compound described in and prepared essentially
according to Example I is used exclu~ively.
ExalQle III
Methyl Pho ~ r
The procedure of Example II i8 repeated except
that 15 moles of methanol are placed ln the reaction
vessel, the overall methanol to phosphorochloridlte mole
ratio belng 15.
Analysls: 16.4% P; 0.5% Cl: OH #287
Example IV
Ethyl Phosphate Ester
The procedure o~ Example II 1~ repeated except
that 15 moles o~ ethanol are u~ed in place Or the methanol.
Th0 mol0 ratio o~ ethanol to phosphorochlorldlte belng 15.
The resultant product i8 a clear ~luid oll.
Analysls: 14.7% P: 0.4~ Cl; OH #19o
Example V
Ethyl Pho3phate Ester
The procedure of Example IV i8 repeated except
that 8 moles-of ethanol are u~ed. The o~erall molar ratio
of alcohol to phosphorochloridlte belng 8. The product
ls a clear fluid oil.
Analysis: 14.6~ P; 0.7% Cl; OH #130

~056393
-12
Example VI
n-Butyl Phosphate Ester
The procedure of Example II is repeated except
that methanol is replaced by n-butanol, and the molar
ratio of n-butanol to the phosphorochlorldite employed
is 7Ø The product is a white w~xy solid.
Analysis: 13.6% P, OH#105
Example VII
2-ChloroethyI Phospha e Ester
The procedure of Example II is repeated except
that methanol is replaced by 2-chloroethanol, and the
ratio of 2-chloroethanol to the phosphorochloridlte em-
ployed is 4.5. The product obtained is a clear oll.
Analysis: 13.8% P; 19.8% Cl; OH #91
Example VIII
2,3 Dibrom propyl Phos~hate Ester
The procedure of Example II 18 repeated except
that methanol is replaced by 2,3-dibromopropanol at a
molar ratio of 2.,3-dibromopropanol to the phosphoro-
chlorldlte of 6. The resultant product is a dark tan
viscous oil.
Analysls: 7. ~ P; 56.2~ Br; 1.7~ Cl; OH #76
Example IX
2-Hydr_xyethyl Phosphate Ester
The procedure of E~ample II ls repeated except
that methanol is replaced by ethylene glycol at a molar
ratlo of ethylene glycol to the phosphorochlorldlte of 6.
The product is a clear oil.
Analysi~: 11.9~ P; OH #432
--12-
. ~

1056393
-13-
Example X
3-Hydrox~ropyl Phosphate Ester
The procedure o~ Example II is repeated except
1,3-propaned~ol is used instead of methanol. A 4 to 1
molar ratio of the alcohol to phosphorochloridite i8
maintained. The product is an oll.
Analysis: 10.4~ P, OH #363
Example XI
2-Chlor ethyl_Phosphate Ester
This example represents an alternate procedure
for the preparation o~ the phosphate esters of this in-
vention by chlorinatlon of a spirocyclic pho~phite where-
in Y is a 2-chloroethoxy group and v is 2 ln the presence
o~ an alcohol. The common lntermediate, the phosphoro-
chloridite, is prepared as descrlbed ln Example I, using
PC13 (280 g~ 2.04 mole) and pentaerythritol (136 1.O
mole) in dlchloroethane (240 ml.) as the solvent. The
resulting solution is treated with ethylene oxide over a ;~perlod of about 2 1/2 hours at about 50C ln presence of
TlC14 (5 drops) untll neutral to moist litmu~ paper.
The resultlng solutlon, now cont~ining the phosphlte,
3,~-bis(2-chloroethoxy)-2,4,8,10-tetraoxa-3,9-dlphospha-
spiro ~5.5~ undecane, 18 dlluted wlth 2-chloroethanol
(161 g, 2 moles) and treated wlth chlorine gas untll the
solution mQintains a sllghtly green color, indicatlng
that substantlally all of the phosphlte has reacted.
During oxidation, cooling wlth an acetone-lce bath 1
requlred to keep the temperature at about 25C. The
reactlon ~olutlon ls neutralized wlth propylene oxide and
concentrated first under 10-20mm Hg presgure and then under
-13-
..... .. . - :

1056393
-14-
0.3mm Hg pressure at about 100C pot temperature. The
product is a cle~r oil.
Analysis: 14.9% P: 20.1% Cl; OH #70
Example XII
_ ._
Preparation of Dichloro (2,6,7-trioxa-1-phos-
phabicyclo ~ .2]oct-4-yl)methyl phosphite. _
_ _ . . ., _ . _ . _ . _ _ _
This bicyclic precursor is prepared as ~ollows: -
a solution of phosphorus trichloride (gl~og.~ o.66 mole)
and 4-hydroxymethyl-2,6,7-trioxa-pho~phabicyclo~2.2.2]
octane [36.0g., 0.20 mole; prepared accordlng to the pro-
cedure descrlbed by W.S~ Wadsworth et al., J.R.C.S,, 84,
p. 615 (1962~in chloro~orm (200 ml) is stlrred at room
temperature for about 3 hours and then kept at reflux-
ing temperature for one hour. The product separates ~rom
solution as white crystals. It i8 separated by flltra-
tion, washed with an excess of carbon tetrachlorlde and
dried ln air. The product has a melting range o~
118-120C.
Analysis: 23.7%P; theory 23.4~P
~ le XIII
Eth~l Pho~Rhate Ester
_ . . .. _.. ~_ ._ . _ .. _
This example lllu~trate~ the preparation of
the phosphate ester of this lnvention from the bicycllc
phosphorohalidlte of Example XII uslng the procedure as
descrlbed ln Example II except that methanol i8 replaced
by ethanol. The mole ratlo of ethanol (62.5g) to the ~ ;
blcyclic pho~phorochlorldlte (30g, 0.113 moles ln 75 nil
of chloroform) la 12. A clear fluld oll 18 obtalned.
Analysls: 16.0~ P; OH ~77
The phosphate esters of this lnvention are
-14-
- - .
- . ~ . . . . . .

1056393
-15-
useful as flame retardants for organic polymerc~particular-
ly resins, and are ef~ective as reactive flame retardants
for polyesters and expecially for rigid polyurethane fOam8.
The OH functionality of these phosphates allows them to be
incorporated into the polymer backbone, thu~ providing a
permanent flame retardant protection to the polymer. In
addition, the preferred compositions, wherein at least Rl
and R are ethyl or 2-chloroethyl, are fluid oils at room
temperature and are ~oluble ln the polyether polyols
normally normally employed in polyurethane production.
This is especially advantageou~ in polyurethane foam
manufacture where homogeneity and low viscosity of the
components, i.e. polyisocyanates and polyols, are eseential.
When used a~ flame retardants in polymers such
as polyesters and polyurethanes, the~e pho6phate ester~
may be incorporated at concentrations of from about 2 to
40 percent, usuAlly from 5 to 15 percent based on the total
weight of the polymer.
Example _IV
~ ~ ane Foam
~ his example illustrates the utillty a~ well as
the superior efficacy of the compounds of the lnventlon
in rigld polyurethane foam
The ~oams are prepared using a conventional one
shot process employing the recipes li~ted on Table I
(Formulation). For thl~ purpose, all the ingredlents ex-
cept the polyl~ocyanate are thoroughly mixed ln a beaker
and thereafter the polyisocyanate 1~ added while rapldly
agitating the mixture with an air-drl~en ~tirrer. The
li~uld contents of the beaker ~re then poured into ~ mold
~'~' ' ' ' .

-16- 10563~3
where within a short period of time a foam develops.
The foam is cured overnight at room temperature, and the
flame resistance is determined by the Oxygen Index test
(A.S,T.M, D-2863).
Experiment A does not include a flame retardant,
and Experiment E contains a well known flame retardant
used commercially in rlgid polyurethane ~oams. Experiments
A and E are outside the scope of this inventlon.
In Table I the flame resistance data of the
~oams are summarized.
The results lndicate that ln all examples where
the compounds of the lnventlon are employed a6 the flame
retardant, the oxygen indices achieved are hlgher than
those of the blank (A) and of the compari60n experiment
(E). The extraordinary and unexpected improvement amounts
to over 30% (Expd. C+D) when compared to the prior art
compound at substantially the same concentratlon. Even
when only one-half of the compound of the inventlon is
incorporated in the polyurethane an lmprovement ls
achieved (B) over the comparison ~oam (E).
-16-

-17-
1056393
Tabl~ I
Co~porations and Re~ults o~ Ex~
Expêrlment A B ~C D E
Formulation parts by weight
Polyol(l) 100 87.6 75 74.2 74.6
Surfactant(2) 2 2 2 2 2
Triethylenedl~nine(3)
Dlmethylethanolamlne(3) - 2 2 - 2
Trichlorofluoromethane 30 30 30 45 30
Methylenebl~(phenyl lso-
cyanate) (crude)(5) 136 121 127 115 126.5
Phosphate of Example V - 12.4 25
Phosphate o~ Exan~le VII - - - 25.8
Commerclal FIame Retardant(62 - - - 25.4
15 Result~
Ox;rgen Index 20.6 23.6 24.5 24.9 23.5
% Improvement(8) _3.4 34. 48.
Remarks: 1) Propylene oxlde adduct of N-amlnoethylpipe-
razlne molecular welght ca. 350, OH ~ ca. 530.
2) Sillcone compound, M-193 of Dow Corning Corp.
3) Catalyst
4) Blowlng Agent
5) Product o~ Rubicon Chemicals, Inc.
6) O-O-dlethyl N,N-ble(Yurdroxyethyl)aminomethyl-
phosphonate.
7) ASTM D-2863
8) Calculated accordlng to equatlon
% Improvement - ~(OII -OIE)/(oIE-oIo)]x 100
whereln
3o OII = Oxygen index of con~position of invention
OIE = " " " Example E (con~arison)
OIo - " " " con~positlon wlthout flame
retardant (A)
- .

-18- 1056393 ::
This example illustrates that the composltlons of
this invention provide rlgld urethane foams having excel-
lent physical properties. The ~oam ~ormulation iB given
in Table II. For compar~son, a widely used reactlve flame
retardant (O,O-diethyl N,N-bis(hydroxyethyl)aminomethyl-
phosphonate), Experiment C, is also included. The physical
properties of the foamæ are summarized in Table II. The
test data demonstrate the superior compressive strength of
E~periment B of the invention over the polymer without A
flame retardant (A) and the one contalnlng a known flame
retardant (C ) .
In addition, friabillty and dimensional stabllity
after aging of sample B is superior to that of sample C
which contains the commercial reactive flame retardant.
-18-
.. ... . - . . . .. .. . , ........ . ........... ~ .. ... . . ..
: . ~ . : .- . - .

1056393
-19-
Table II
Results of Exa~le XV
Foam Formulation
Components A B C
Polyether polyol(l) 100 100 100
Silicone Surfactant
(DC 193 Dow Corning) 1,5 1.5 1.5
Triethylenediamlne 1,0 1,0 1,0
Dibutyltin dilaurante 0,2 0,2 0,2 -
Trichlorofluoromethane 40 40 40
Phosphate prepared arcording
to Ex~mple V - 20,5~ ) -
0,0-Diethyl N,N-bis(hydroxy-
ethyl)aminomethylphosphonate - - 25,5(2)
15 Methylenebis(phenylnocyanate
(crude)
Physical Properties
. .
Density, psf 1.96 2,19 2,50
Compressive strength, p8i: .
Parallel to foam rlse34.9 43.9 36,1
Perpendicular to foam rise 19,6 23.7 19,9
Friability, j¢ loss 13,6 17.7 ~ 23.9
% Closed cells 84.5 86.o 84.4
Dimen~lonal Stabllity (1 week),
% Vol change
158F, Dry 1,2 0.4 0.5
158F~ 97% RH 4,3 6,o 12,0
25~F, Dry 9,7 13.4 19,4
(1) Propoxylated sorbitol havlng an OH~ of about 550,
(2) Foams were formulated to give ~ame phosphorous con-
cen+,r~t.ion (ca, 0,9%) for both samples.
-19- ~ :