Note: Descriptions are shown in the official language in which they were submitted.
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~ ; invention relntcfi to novcl Elrc retardant
- composltion3 and morc par~lcularly relate~ to fire retardant
polymeric compositlons containing as an es~ential ingredlent
a halogenated compound of this invention.
It is known that the fire retardant properties of
various polymeric materials may be enhanced by the addition
of various halogenated organic compounds which are derived
from polyhalogenated cyclopentadiene. It has now been found )
that when certain of these compoundg contain both chlorine and
bromine substituents they impart exceptional fire retardant
properties to combustible polymers when incorporated therein.
The compounds of this invention which possess these
desirable fire retardant properties can be represented by the
following structural formula
:, ' ,.
C L
C~ ~ Br ~,
Cl X (I)
wherein X ls selected from the group consisting of hydrogen,
chlorine and bromine. Thus, one embodiment of the present ~ -
invention resides in a fire retardant polymeric composition
comprising a combustible polymer and a halogenated compound
having the structure as defined by Formula I.
The halogenated compounds falling within the scope
of the present invention are 1,2-dibromo-4,5,6,7,8,8-hexa-
30 chloro-3a,4,7,7a-tetrahydro-4,7-methanoindane, 1,2-dibromo-
3,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane
and 1,2,3-tribromo-4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro-
.~
qP
m~p~
~ .
, . . .
4,7-metllanoin~an~ lO5 Z9 ~
The halogenatcd compounds of thls inventlon in
addition to exhiblting exccptional fire retardant propertie~
are less toxic and more biodegradable than the closely related
compounds.
The preparation of these compoundfi is described
in the following examples.
Example 1
Preparation of 1,2-Dibromo-4,5,6,7,8,8-hexachloro-
3a,4,7,7a-tetrahydro-4,7-methanoindane_ _
; lC
4,5,6,7,8,8-Hexachloro-3a,4,7,7a-tetrahydro-4,7-
methanoindane (170 grams; 0.5 mol), ferric chloride (1 gram)
and carbon tetrachloride (500 ml) were charged into a glass
reaction flask equipped with a mechanical stirrer, thermometer,
- reflux condenser and addition funnel. The mixture was heated
at reflux and a solution of bromine (80 grams; O.S mol) in
carbon tetrachloride (100 ml) was added dropwise over a period
of about 1 hour. After the addition was completed stirring was
continued for a period of about 1 hour. After this time the
reaction mixture was treated with powdered activated carbon.
The carbon was then removed by filtration and the filtrate was
stripped of solvent on a rotary evaporator. The residue was
recrystallized from isopropyl alcohol to yield the desired
product 1,2-dibromo-4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro-
4,7-methanoindane having a melting point of 123 to 130C.
Example 2
Preparation of 1,2-Dibromo-3,4,5,6,7,8,8-heptachloro-
3a,4,7,7a-tetrahvdro-4,7-methanoindane _
3,4,5,6,7,8,8-Heptachloro-3a,4,7,7a-tetrahydro-
4,7-methanoindene (187 grams; O.S mol), ferric chloride
(1 gram) and csrbon tetrachloride t500 ml) were charged into a
glass reaction flask equipped with a mecllanical stirrer,
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thermometer, reflux con~enser and additlon funnel. The mixture
was heated at reflux and a solutlon of bromine (80 grams; 0.5 mol)
in carbon tetracllloride (100 ml) was added thereto over a period
of about 2 hours. After the addition wag completed heating was
continued for an additional hour. After this time the reaction
mixture was treated with activated powdered carbon. The csrbon
was then removed by filtration and the filtrate evaporated on a
rotary evaporator, The residue was recrystallized from isopropyl
alcohol to yield the desired product 1,2-dibromo-3p4,5,6,7,8,8-
heptachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane melting at
127 to l38C.
Example 3
; Preparation of 1,2,3-Tribromo-4,5,6,7,8,8-hexachloro-
~; 3a 4 7 7a-tetrahvdro-4 7-methanoindane
,
- 4,5,6,7,8,8-Hexachloro-3a,4,7,7a-tetrahydro-4,7-
methanoindene (170 grams; 0.5 molj benzoyl peroxide (0.1 g) ;-
and carbon tetrachloride were charged into a glass reaction
~,CJ vessel equipped with a mechanical stirrer, thermometer, reflux ` ~--
condenser and addition funnel. This mixture was heated at
reflux and a solution of bromine (80 grams) in carbon tetra-
chloride (100 ml) was added as rapidly as the color disappeared. ~ ~ -
After this addition was completed ferric chloride-~l gram) was
added to the mixture and additional bromine (80 grams) dissolved
in carbon tetrachloride (100 ml) was added dropwise over a
period of about 2 hours. After this time the reaction mixture
was treated with powdered activated carbon. The carbon was
removed by filtration and the filtrate was stripped of solvent - -
in a rotary evaporator. The residue was recrystallized from
isopropyl alcohol to yield the desired product 1,2,3-tribromo-
4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane
melting at 140 to 149C.
The halogenated compounds of this invention impart
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: , ' ' : '
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flre re~ardallt propcrtlcs to colllbustl~lc polymeru by formlng
an ln~lmate ~dn~lxture therewlth. Thls adm~xture can be
readlly preparcd by one of several methods well known ln the
art For example the halogenated compounds can be sdmlxed
lnto the combustible polymer while the latter is di6solved in
a ~uitable solvent. This procedure is especially useful when
it i8 desired to mix the halogenated compounds during the
preparation of t~e polymer. The halogenated compound can also
` be mixed with the combustible polymer in the molten state at a
temperature than can range from the melting point of the poly-
mer to a temperature just below the decomposition temperature
of the polymer. Another method of forming an intimate admixture
comprises dry blending the halogenated compound with the polymer
in the finely divided state. Subsequent molding or extrusion
of this blend can then result in a substantially homogeneous
composition.
The fire retardant polymeric compositions of the
instant invention can contain from about 5 to about 50 weight
. percent of on~ or more of the halogenated compounds of Formula
I. The exact amount of halogenated compound employed will
tepend upon such factors as the degree of fire retardancy ~ -
desired, the specific combustible polymer used, the end use of
the resulting product and the like.
The halogenated compounds of this invention can impart
; fire retardant properties to combustible polymers. Exemplary
of such polymers which can be used in admixture with the
halogenated compounds to form the fire retardant polymeric
compositions of this invention are the homopolymers and copoly-
mers of unsaturated aliphatic, cycloaliphatic and aromatic
hydrocarbons, such as polyethylene, polypropylene, polybutene,
ethylene propylene copolymers, copolymers of ethylene or
propylene with other olefins, polybutadiene, polymers of butadiene,
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polyi~oprenc, poly~tyr~ne, polyvlnylidene, and polymers of
pentene, hexene, heptenc, octcne, 2-methylpropene-1, 3-methyl-
butene-l, 4-~ethylpentene-1, 4-methylhexene-1, 5-methylhexene-1,
bicyclohexene (2.2.1), pentadiene, hexadiene, 2,3-dimethyl-
butadiene-1,3, 2-methylpentadiene, vinylcyclohexene such as
4-vinylcyclohexene, cyclopentadiene, methylstyrene and the like.
Other useful polymers include indene-coumarone resins, polymers
of acrylate este~s and polymers of methacrylate esters, acrylate
and methacrylate resins such as ethyl acrylate, n-butyl meth- ~
acrylate, isobutyl methacrylate, ethyl methacrylate, and methyl ;
methacrylate, alkyd resins, hydrocarbon resins from petroleum, -
isobutylene resins, polyurethanes, polyester resins such as
-~ unsaturated polyesters of dibasic acids and dihydroxy compounds,
polyester elastomers, polyisobutylene, rubbers such as natural ~ -
rubber, synthetic polyisoprene, chlorinated rubber, polybutadiene, '
cyclized rubber, butadiene-acrylonitrile rubber, butadiene- ;~--
styrene rubber, butyl rubber, neoprene rubber, polystyrene? `
terpene resins, urea resins, vinyl resins such as poly(vinyl
acetal), poly~vinyl acetate), vinyl alcohol-acetate copolymer,
poly(vinyl alcohol), poly(vinyl alkyl ether), vinyl methyl
ether-maleic anhydride copolymer, poly(vinyl chloride), poly
(vinyl butyral), vinyl chloride-acetate copolymer, poly(vinyl ---
pyrrolidone) vinylidene chloride copolymers and the like.
Additional useful polymers include nylon, diallyl phthalates
and phthalate resins and polyearbonates,
The fire retardant compositions of this invention can
also contain ad~uvants which in conjunction with the halogenated
compounds improve the fire retardancy of the composition and in
some instances provide synergistic results not obtainable with
the use of the individual compounds. Such ad~uvants can comprise
antimony compounds such as antimony trioxide, zinc borate, lead
arsenates such as Pb~As04 and the like. These ad~uvants can
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co~nprise from nbout 1 to about 35% by wcight of the total
compo~itlon.
The effectiveness of the halogenated compounds of
thls invention as flame retardAnts was demonstrated in experi-
ments wherein fire retardant composltions comprising the
halogenated compounds and various combustible polymers were
sub~ected to a flammability test using the oxygen index method.
The flammability test was carried out in accordance with the
general procedures detailed in the ASTM D 2863-70 te6t method.
This method provides a procedure for determining the relative
flammability of plastics by measuring the minimum concentration
of oxygen expressed as volume percent, in a slowly rising
mixture of oxygen and nitrogen that will ~ust support com-
bustion. The results of these experiments are set forth in
the following Examples. In each of these examples the components
were blended in the molten state using a dough blender.
Composition Oxygen Index;
' Example 4 Parts by Weight Percent
- Polyethylene 60 35.5
Product of Example 1 40
Example 5
Polyethylene 60 27.5
Product of Example 2 40
Example 6
Polyethylene 60 33.0
Product of Example 3 40
Example 7
Polyethylene 60 33.5
Product of Example 3 30
Antimony trioxide 7
Zinc borate 3
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ComposiLion Oxygen Index
-'' Part~ by Wei~,ht _ Pcrcent
l,x.~mple 8
Polyethylelle 65 32.0
Protuct of Example 1 25
Antimony trioxide 7
Zlnc bo rate 3
Example 9
A B S * 60 40.0 ,
Product of Exampl,e 1 40
:. , .
Example 10 ' '~ ~
ABS 60 38.0 -,
Product of Example 2 40
, Example 11
'' ABS 62 38.5 -'
., .
Product of Example 3 38
:: .
~, Example_12
Polystyrene 60 >40.0
Product of Example 1 40
` Example 13 '-
20, Poly'styrene ~ 60 >40.0
Protuct of Example 2 40
Example 14
Polystyrene 60 >40.0
Product of Example 3 40
The above data demonstrates the flame retardant prop-
erties of the compositions of this invention. It can be seen ~ ' ,
when the foregoing values are compared to the standard oxygen
~ndex of polyethylene and polystyrene which are 17.4 and 18.lX ~
respectively (as published in the Flammability Handbook for --
Plastics; Carlos Hilado, 1969) that the halogenated compounds
of the present invention are very effective as flame retardants
for combustible polymers.
*Terpolymer of acrylonitrile, butadiene and styrene.
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, .. . . .
