BROMINE-CONTAINING OLIGOMERIC ETHERS AND PROCESS FOR THEIR PRODUCTION

PROCEDE D'OBTENTION D'ETHERS OLIGOMERIQUES CONTENANT DU BROME

English Abstract

ABSTRACT OF THE DISCLOSURE :
The present invention relates to bromine-con-
taining oligomeric ethers containing structural units corres-
ponding to the formula
<IMG>
in which X = Br, Cl or H, n = 0 to 4, p, the average degree
of condensation is from 2 to 10 and y independently of one
another represents Br, Cl or H, the sum X+Y containing at
least two Br-atoms, and Z represents a direct bond, -CH2-,
C(CH3)2 or -SO2-. The invention is also directed to a
process for obtaining the above said compounds which are
suitable for use as flameproofing agents for numerous plastics.

Claims

The embodiments of the invention in which an exclu-
sive property or privilege is claimed are defined as follows:
1. A bromine containing oligomeric ether having
structural units of the general formula
<IMG>
in which X represents bromine, chlorine or hydrogen, n = O to 4,
p, the average degree of condensation is from 2 to 10 and each
Y independently represents bromine, chlorine or hydrogen, X and
Y together including at least two bromine atoms, and Z represents
a direct bond, an alkylene radical or the group -SO2-.
2. An oligomeric ether according to claim 1
wherein the alkylene radical Z is -CH2- or -C(CH3)2-.
3. An oligomeric ether according to claim 1 or 2
wherein X and Y together include from 3 to 5 bromine atoms.
4. An oligomeric ether according to claim 1 or 2
wherein the xylenyl component of the structural unit is a
meta or para xylenyl component.
5. An oligomeric ether according to claim 1
wherein all the substituents Y represent bromine.
6. An oligomeric ether according to claim 1
wherein all the substituents Y represent chlorine.

7. A bromine containing oligomeric ether accor-
ding to claim 1 having the general formula
<IMG>
in which X, Y, Z, n and p are as defined in claim 1, A represents
a halogen atom, an optionally nucleus-halogenated aryloxy radical
or the radical
<IMG>,
B represents hydrogen/ an optionally halogen-substituted alkyl
or aralkyl radical, or the radical
<IMG> ,
wherein X, A and n have the above meanings.
8. An oligomeric ether according to claim 1 or 7,
wherein p is from 3 to 7.
9. An oligomeric ether according to claim 7,
wherein A represents a chlorine atom.
16

10. An oligomeric ether according to claim 7,
wherein A represents a phenoxy radical having the formula
<IMG>
where R represents a hydrogen, chlorine or bromine atom or
a methyl group.
11. An oligomeric ether according to claim 7,
wherein B represents a benzyl radical of formula
<IMG>
where R represents a hydrogen, chlorine or bromine atom or
a methyl group.
12. A process for producing a bromine containing
oligomeric ether having structural units of the general formula
<IMG>
in which X represents bromine, chlorine or hydrogen, n = 0 to 4
and each Y independently represents bromine, chlorine or hydrogen,
X and Y together including at least two bromine atoms, and Z
17

represents a direct bond, an alkylene radical or the group
-SO2-, which process comprises reacting a xylylene dihalide of
formula
<IMG>
where Hal represents a halogen atom, with a bisphenolate of
formula
<IMG>
to form the desired oligomeric ether.
13. A process according to claim 12, wherein the
alkylene radical Z is -CH2- or -C(CH3)2-.
14. A process according to claim 12 or 13, wherein
Hal represents a chlorine atom.
15. A process according to claim 12, wherein the
bisphenolate is formed in situ by reaction of the free bisphenol
with a base.
16. A process according to claim 15, wherein the
base is an alkoxide, hydroxide or carbonate of an alkali or
an alkaline earth metal.
18

17. A process according to claim 16, wherein
the alkali metal is sodium or potassium.
18. A process according to claim 12, wherein the
reaction is carried out in dioxane, methyl glycol or an aromatic
hydrocarbon as solvent.
19. A process according to claim 12, wherein the
xylylene dihalide and bisphenolate are used in a molar ratio of
from 1:1 to 1:1.35.
20. A process according to claim 12, wherein the
reaction is carried out at a pressure of up to 10 bars.
21. A process according to claim 12, wherein the
reaction is carried out at a temperature of from 80 to 150°C.
22. A process according to claim 21, wherein the
reaction is carried out at a temperature of from 90 to 120°C.
23. A process according to claim 12, which includes
the additional step of introducing a mono phenol or a mono
halogen alkyl compound to the reaction mixture to close the
terminal groups of the oligomeric product.
24. A composition comprising a polymeric material
and, as flameproofing agent therefor, a bromine containing
oligomeric ether according to claim 1.
25. A composition according to claim 24, con-
taining from 4 to 20% by weight of oligomeric ether, based on
the total weight of the composition.
19

26. A composition according to claim 25, con-
taining from 5 to 16% by weight of oligomeric ether based on
the total weight of the composition.
27. A composition according to claim 24, which
additionally includes a substance which acts synergistically
with the oligomeric ether.
28. A composition according to claim 27, con-
taining up to 5% by weight of the substance.
29. A composition according to claim 27 or 28,
wherein the substance is antimony trioxide.
30. A composition according to claim 24, wherein
the polymeric material is a homopolymer or copolymer of ethylene,
propylene, butadiene, styrene or acrylonitrile.
31. A shaped article when formed from a composi-
tion according to claim 24.

Description

1~2~3~199
This invention relates to bromine-containing oligo-
meric xylylene~bisphenol ethers, to polymer compositions flame-
proofed therewi-th and to the production of the oligomeric ethers.
The ethers according to the invention contain s~ruc-
tural units corresponding -to the Eormula
X Y Y
n~
~-C~2 ~ 2 ~ ~ ~ O ~ '~)~
in which X represents Br, Cl or H, n = 0 to 4,p, the average degree
of condensation is from 2 to 10 and y independently of one another
represents Br, Cl or H, at leas-t two Br-atoms being present in
the sum (X+Y), and Z represents a direct bond~an alkylene radical
in particular -ctcH3)2- or -CH2-, or -SO2-.
In the structural unit, the substituents X~Y should
preferably contain from 3 to 5 bromine atoms.
The structural units consist of radicals of xylenes
and bisphenols etherified with one another. The xylene radicals
are derived from o , m- or p-xylenes, preferably from m- and
p-xylenes, which are unsubstituted, chlorinated, brominated or
chlorobrominated in the nucleus. Examples of such m- or p,-xylenes
are 2-bromo-,p-xylene, 2,5-dichloro- or -dibromo-p-xylene, tetra-
chloro-_- or p-xylene, tet-rabromo-m- or p-xylene, 2,3,5-tribromo-
6-chloro-p~xylene and from mixtures of the type whlch may be
obtained for example by chlorinating, bromina-ting or chloro-
brominating xylenes.
The bisphenol radicals are preferably derived frcm 2,2-bis-
(~-hydroxyphenyl)-propane (bisphenol A.-dian) and 4,4'-dihydroxy-
diphenylsulphone and nucleus-halogenated derivatives thereof,
particul~rly the 3,3',5,5'-tetrachloro- and -tetrabromo
derivatives.
-- 1 --
.,~ ~.
.

~.29~9
~ he ethers according to the invention correspond to
the general formula
~ CI~z ~ C~l~-0 O ~ ~Z r ~ ~~)e~~
in which X, y, Z, p and n are as defined above, A represents Cl,
optionally Br, an op-tionally nucleus-halogena-ted aryloxy
radical or
y,
~> { ' I
X~ :
and B represents H, -CH2 l ~ - ~ 2
or an optionally haloyen-substituted alkyl or aralkyl radical.
The ethers are present in the form of oligomer mixtures with
an average degree of condensation p preferably of
from 3 to 7. The average degree of condensation is the most
frequent degree of condensation in a distribution curve, for
example according to Flory, degrees of condensation of down to
2 and up to about 30 or higher can occur in the mixture.
Oligomeric ethers or their mixtures in which A
represents a phenoxy radical of the formula
:~
~ '

~ Z9889
and B represents an H-atom or
X~
2 ~ ~ 2
are preferred.
Mixtures of oligomeric ethers in which B represents
an H-atom or a benzyl radical of the formula
-C~
~nd A represents a Cl-atom or -0 ~ O ~ -Z < O ) 0-B:
in A and B, R represents H, CH3, CL or Br.
Although several monomeric halogen-containing e~hers
are known as flameproofing agents, losses of substance and
effect readily occur in their case through evaporation and
migration. The properties of the plastics are adversely affected
by, in some cases, plasticiser-like behaviour.
These disadvantages do not attend the oligomeric ethers
according to the invention.
The fact that the xylyle~e radical can be introduced
by reaction of the corresponding xylylene dichlorides contributes
towards the simple production of the oligomeric ethers.
The oligomeric ethers and their mixtures can be
obtained simply and in high yields.
No additional outlay is involved in the production of

9~
the oligomeric ethers in relation to monomeric ethers.
In one suitable produc-tion process for example,
xylylene dihalides, particularly the dichlorides, are reacted
in suitable solvents with alkali or alkaline-earth me~al salts
of the bisphenols, par-ticularly the Na or I~ salts. Instea~ of
using the bisphenolate, it is also possible to use the free
bisphenols and to add the necessary quantity of basic alkali
or alkaline-earth metal compounds, for example Na or K alkoxides,
hydroxides or carbonates, at the beginning of or during the
reaction, i.e. to produce the phenolate in situ.
Suitable temperatures are in the range from 85 to 150C
(preferably from 90 to 120C).
The reaction is preferably carried out under normal
pressure, although pressures of up to about 10 bars may be
applied. Suitable solvents are dioxane, methyl glycol, aromatic
hydrocarbons such as o~xylene or toluene, optionally their
mixtures and other solvents having boiling points of from about
85 to 150C.
The reactants may be used in a molar ratio of from
1:1 to about 1:1.35.
The terminal groups of the oligomeric ethers may be
influenced through the molar ratio of the xylylene and bisphenol
components. If for example the bisphenol is used in a molar
excess, the products predominantly contain terminal OH-groups,
as is exemplified by the following reaction scheme:
E! ClC1~2~ C112CI + (~'~1) 110~ `/`011
HO ~ \r ~ O- (CH2 ~ CH2-0 ~ -z- ~ -O-)~-H
y/
Y Y
_ ~ _

~ ~
~2~8~
By contrast, if the xylylene dichloride is used in a
molar excess, ClCH2 terminal groups predominate.
Where -terminal reactive yroups are undesirable, -they
may be closed by etherification with monofunctional haloyen-
alkyl compounds or monophenols. In order not to re~uce the
halogen content of the oligomeric ethers, compounds with a
sufficiently high halogen content are preferably used for
closing the terminal groups. Accordinglyl nucleus-halogenated
. phenols corresponding to the general formula
Xn
H0 - ~ -R
for example pentachlorophenol, tribromo- or pentabromophenol,
optionally even halogen cresols, are suitable for etherifying
the terminal halogen methyl groups, whilst halogen alkyl compounds,
part7cularly nucleus-halogena-ted benzyl halides of the general
formula
Xn
XCH~ R
for example pentachloro- or pentabromo-benzyl chloride, are
suitable for etherifying the terminal OH groups. In these
formulae, R represents 11, Cl, Br or CI13.
Any terminal chloromethyl groups of the oligomers
which are formed should generally be closed in the manner
described.
The molar quantities of the compounds used for closing
the terminal groups is governed by the number of functional

~IL2~
terminal groups which is in turn dependent upon the degree
of condensation ~.
If for example the starting materials are used in
quantities of 4:5 or 5:~ moles, the mixture obtained has an
average degree of condensation p of about ~ and from 1.~ to 2
moles of monofunctional compound may be added together with
the equivalent quantity of alkali a-t the end of the reaction to
close the terminal groups and the excess removed.
The compounds used for closing -the terminal groups
are with advantage added at the end of the condensation reaction
in the same operation.
In this production process, the bromine~containing
ethers are obtained in the form of oligomer mixtures. Although
it is possible to produce defined oligomers by reacting the
components in stages and subsequently isolating the respective
intermediate compounds formed, -this method is extremely complica-
ted and is nei-ther necessary nor advantageous for the proposed
use of the products as flameproofing agents.
The ethers according to the invention are solid
substances with very little, if any, colour of their own. They
are insoluble in water and, by virtue of their relatively high
molecular weight, are also completely or substantially insoluble
in lower alcohols, acetone and aliphatic hydrocarbons. Their
solubility in aromatic and chlorinated hydrocarbon solvent,
dimethyl formamide and particularly cyclic ethers, for example
dioxane and tetrahydrofuran, is better. Like the melting
range of the oligoethers, it is also in~luenced by different
components and molecular weights. Full particulars on the
production and properties of the ethers are given in Examples
1 to 12 and in Table 1.
The bromine-containing oligoethers according to the
invention are suitable for use as flameproofing agents for

1~2~8~3~
numerous plastics, particularly for homopolymers and copolymers
of ethylene, propylene, butadiene, styrene and acrylonitrile.
The new oligoe-thers have several major advantages over known
low molecular weiyht monoethers or diethers. For exarnple, by
virtue of thelr much lower vapour pressure, their volatility,
even at relatively high temperatures, is so low that there is
virtually no loss of flameproofing ayent and effect during their
incorporation into plastics compositions and during their
processing into shaped articles. Another advantage of the
relatively high molecular weight oligoethers is their lower
tendency towards migration. They prevent the flameproofing
agent from migrating from the surface of the plastics material
("chalking out") and hence, in conjunction with their low
volatility, also prevent losses during prolonged storage. In
addition, by virtue of their relatively high molecular weight,
the solubility or rather the molar concentration of the
oligeothers in the polymer and hence their influence upon
the properties of the polymer are reduced.
The flameproofing effect of the bromine-containing
oligoethers can be improved by the usual additives, particularly
antimony trioxide.
Some of the oligoethers were incorporated into various
polymers and copolymers and their flameproofing effect measured
by method UL 94 of the Underweiters' Laboratories and the
Limiting Oxygen Index method (LOI) according to ASTM D 2863-74.
The results are shown in Example 13.
The quantitles of the oligomeric ethers in plastics
may amoun~ to between 4 and 20% by weight and preferably to
between 5 and 16% by weight, optionally in addition to synergis-
tically acting metal oxides, such as antimony trioxide,in
quantities of from 0 to 5% by weight.
The invention will now be ~urther understood by means
of the following non-restrictive examples.
-- 7 --

8~
EXAMPLE 1
272 g of 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-
propane ("-tetrabromodian") were dissolved in a mixture of 125 g
of 32% sodium hydroxide solution and 950 ml of dioxane, followed
by the addi-tion with stixring of 196 g of -tetrachloro-~-x~lylene
dichloride. The mix-ture was boiled under reflux for 4 hours
at temperatures increasing from 90 to 101C, after which a
solution of 63 g of 2,4,6-tribromophenol in 125 ml of dioxane
and 32 g of 32~/o sodium hydroxide solution was added and the
mixture kept a-t boiling tempera-ture for another hour. After
the removal by distillation of 720 ml of aqueous dioxane, which
was used for further batches, the reaction mixture was stirred
into 4 litres of water and the deposit was filtered off under
suction. It was washed with water and methanol and dried
in vacuo at 100 to 120C.
The oligomeric tetrachloro-p-xylylene tetrabromodian
ether containing terminal tribromophenoxy groups was obtained
as a brownish-white powder in a yield of 458 g, corresponding
to 94.3% of the theoretical. For further particulars, see the
Table under Example 5
EXAMPLE 2
123 g of tetrabromo-p-xylylene dichloride and 73.2 g
of 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane were heated
with stirring to boiling temperature with 350 ml of dioxane,
followed by the dropwise addition over a period of 1 hour of
39 g of 40% sodium hydroxide solution. Thereafter, the mixture
was boiled under reflux for 3 hours, a solution of 25 g of 2,4,~-
tribromophenol in a mixture of 12 g of 40% sodium hydroxide
solution and 50 ml of dioxane was added and the mixture boiled
for another hour. 270 ml of aqueous dioxane were then distilled
off and the viscous distillation residue stirred into 1.8 litres
of water. The deposit was filtered off under suction, washed
-- 8 --

~ 9~
with water and methanol and dried in vacuo at 120C. Yield
of tetrabromo-p-xylylene tetrachlorodian ether containing
terminal tribromophenoxy groups: 185 g (91.1% of -the theoretical)
of a yellowish-white powder~
EXAMPLE 3:
63 g of tetrachloro-p-xylylene dichloridel 136 g of
2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane and 350 ml of
dioxane were mixed while stirring, followed by the dropwise
addition over a period of 1 hour at boiliny temperature of a
mixture of 42 g of 40% sodium hydroxide solution and 25 ml
of dioxane. After boiling under reflux for 3 hours, 52 g of
pentabromobenzyl chloride and a mixture of 10 g of 40% sodium
hydroxide solution and 50 ml of dioxane were added. The mixture
was then stirred for 1 hour at boiling temperature, after which
300 ml of dioxane/water were distilled off and the hot residue
was stirred into 1.8 litres of water. After a few hours, the
- deposit was filtered off under suction, washed with water and
methanol and dried in vacuo at 100 to 120C. 228 g of tetra-
chloro-p-xylylene tetrabromodian ether containing terminal
pentabromobenzyl groups were obtained in the form of a white
powder (97.9% of the theoretical).
EXAMPLE 4:
90.6 g of 3,3,5,5-tetrabromo-4,4-dihydroxy diphenyl
sulphone were dissolved in 400 ml of dioxane and 31 g of 40%
sodium hydroxide solution, 98.2 g of tetrabromo-p-xylylene
dichloride were added and the mixture stirred for 30 minutes.
It was then slowly heated to boiling temperature and boiled
under reflux for 4 hours. Following the addition of a solution
of 20 g of 2,4,6-tribromophenol in 40 ml of dioxane and 10 g
-of 40% sodium hydroxide solution, the mixture was boiled for
1 hour, 300 ml of aqueous dioxane were distilled off and -the
viscous residue poured with vigorous stirring into 1.5 litres
_ g _

889
of water~ The suction-filtered deposit was washed with water,
predri~d at ~0C, rewashed with 350 ml of me-thanol and dried
in vacuo at 100 to 120C. The oligomeric te-trabromo-p-xylylene
tetrabromodiphenyl,sulphone ether con-taining te~minal tribromo-
phenoxy groups was obtained in a yield of 169 y (87% of the
theoretical) as a yellowish powder.
EXAMPLES 5 to 12:
Following the procedure of Example 1, the starting
materials identified in Table 1 for each of Examples 5 to 12 were
reacted to form the oligomeric ethers of the corresponding
components of which the analytical data are shown in Table 1.
The results of Examples 1 to 12 are set out in Table 1.
Components (columns 1 to 3): the abbreviations under
"C" (xylylene radical), "D" (diphenoxy radical) and "terminal
groups" have the following meaning:
TBX = tetrabromoxylylene
TCX = tetrachloroxylylene
C = xylylene (non-halogenated)
D = 2,2-bis-(4-hydroxyphenyl)-propane ("dian")
TBD = 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane
TCD = 2,2-bis-(3,5-dichloro-4-hydroxyphenyl~-propane
DPS = 4,4'-dihydro~ydiphenyl sulphone
TsS = 3,3',5,5'-tetrabromo-4,4'-dihydroxydiphenyl sulphone
TPB = 2,4,6-tribromophenoxy
PBB = pentabromobenzyl.
Yield (column 4): the percentages are based on a
complete conversion of the starting materials used (=100%).
Halogen content (columns 5-7): in the TBX and PBB radicals,
a small proportion of the bromine in the nucleus is replaced
by chlorine. Accordingly, the total halogen content is below
the calculated value. Melting range (column 8): all the
substances melt completely, but as oligomer mixtures have
-- 10 --
i~, .

~9~
no defined melting point.
Weight losses (column 9) the temperatures at which
the thermogravimetrically determined weight losses arnount
respectively to 1 and 5% (heating rate: 8C per minute) are
quoted as a measure of thermal stabili-ty.
-- 11 --

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-- 12 --

9~9
EXAMPLE 13 (Use):
12 g of an oligomeric ether according -to Ex.amples 1
to 12 and 4 g of antimony trioxide were incorporated in the
usual way by rolling or extrusion into batches of 100 g of
standard commercial-grade granulated polyethylene. Test
specimens were produced by moulding or injection from the
compositions thus obtained for measuring flammability by the
Oxygen Index Method (ASTM D 2863-74) and the UL-94 Method
(Underwriters' Laboratories Inc.). The results are set out
in Tables 2 and 3. The oligomeric ethers used as flameproofing
agents are identified by the Nos. of the Examples mentioned in
Table 1.
The following commercial products were used as
polymers:
polyethylene : Hostalen*GF 7750 (Hoechst AG)
polypropylene : Hostalen~iPPN 1060 (Hoechst AG)
polystyrene : Type 432 F (BASF AG)
ABS : Novodur (Bayer AG) - a terpolymer of acryloni-
trile, butadiene aIId
styrene
EPDM : Nordel 402 T (Du Pont ~ Co.) - a terpolymer of
ethylene, propylene and
dienes such as norborna-
diene
Table 2: Testing by the Oxygen Index Method
Test specimen dimensions: 52 x 140 x 1 mm, the figures
indicate the limiting oxygen index (LOI) in % by
volume of 2~
Polymer Example 2 3 ¦ 4 9 11 12 addition
i _ _
Polyethylene 26.5 24.5 26.6 23.0 26.8 21.9 17.3
Polypropylene 31.0 29.2 30.0 30.8 29.2 31.7 I7.4
Polystyrene 23.3 22.4 23.8 24.4 24,7 22.8 17.4
ABS 23.0 22.3 24.2 24.9 22.1 23.2 17.6
EPDM 25.5 23.2 25.1 22.6 25.2 23.0 17.5
* Trademark
- 13 -
... .

Table 3: Testing by the UL-94 Method
Test specimen dimensions: 12.7 x 127 x 1.6 mm
The ratings used are as follows:
V0 = self-extinguishing after at most 5 seconds,
no inflaming drips
Vl = self-extinguishing after at most 25 seconds,
no inflaming drips
V2 = self-extinguishing after at most 25 seconds or
the substrate is inflamed
Polymer Exemple 1 2 9 10 11 12
Polypropylene V0/V0 V2/V2 Vl/Vl V0/V0 V0/V0 Vl/Vl
Polystyrene V0/V0 Vl/Vl V0/V0 V0/V0 V0/V0 V0/Vl
ABS VQ/V0 V2/V2 V2/V2 V2/V2 V0/V0 V2/V2
The first values were obtained without pretreatment
of the test specimens and the second values (after the oblique~
after ageing for 7 days at 70C.
- 14 -