Note: Descriptions are shown in the official language in which they were submitted.
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Flame-protected eatrudates, and flame-protected moulded articles produced by
means of compression moulding processes
The invention relates to flame-protected extrudates, especially films, sheets
and
wire-coatings, based on polyalkylene terephthalate and pentabromobenzyl
polyacrylate (PBBPA) having improved resistance to tearing and elongation at
tear
(stress at break and breaking elongation), electrical properties and surface
quality.
As is known, for example, from the literature Kunststoffe 80 (1990), pages 3
and 4,
plastics, such as thermosetting plastics, elastomers, polyamide,
polycarbonate, etc.,
can be rendered flame-resistant by the use of halogenated hydrocarbons.
It will be seen from the literature references mentioned above that although
plastics
parts containing halogenated hydrocarbons have a good flame-resisting action,
they
have a poor surface quality on account of the halogen-containing flame-
protecting
additives used hitherto, so that it is not possible to produce flame-protected
films or
mouldings having very thin walls from PBT.
Pentabromobenzyl mono- and poly-acrylate and their use as a flame-protecting
agent
in thermoplastic resins are described in EP-A 344 700. Extrudates, such as,
for
example, films and sheets, having the desired properties are not described
therein.
The object of the present invention is to provide flame-protected extrudates,
such as
films, sheets and wire-coatings, based on polyalkylene terephthalate and a
commercially available, inexpensive and hence economical flame-protecting
agent,
which extrudates have a high surface quality, improved electrical properties
and
improved resistance to tearing and elongation at tear (stress at break and
breaking
elongation) and can be produced from the thermoplastic moulding compositions
in a
simple manner by conventional techniques, for example extrusion, blow
moulding,
compression moulding processes.
~
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It has been found that extrudates (films, sheets and wire-coatings) and
moulded
articles produced by the compression moulding process which are based on
polyalkylene terephthalate and which are provided with a pentabromobenzyl
polyacrylate (PBBPA) unexpectedly have an excellent surface and good flow
properties while at the same time having very good flame-resistant behaviour
with a
high resistance to tearing and elongation at tear (stress at break and
breaking
elongation), their electrical properties being high and the remaining
properties being
good, without the thermoplastic matrix being damaged. A further advantage of
the
invention is that the thermoplastic moulding compositions based on
polyalkylene
terephthalate and PBBPA can be processed in an excellent manner to extrudates
(films, sheets and wire-coatings), for example by extrusion, blow moulding,
the
drawing out of looms, and to moulded articles by compression moulding
processes.
The extrudates (films, sheets and wire-coatings) and moulded articles,
produced by
1 S the compression moulding process, according to the invention can then be
processed
further by conventional techniques, for example deep drawing, printed on
and/or
inscribed by laser.
The present invention provides moulded articles produced by the compression
moulding process and extrudates, especially films, sheets and wire-coatings,
based
on thermoplastic moulding compositions containing
A) from 55 to 97.7 parts by weight, preferably from 60 to 95.5 parts by
weight,
especially from 70 to 95 parts by weight, of polyalkylene terephthalate,
B) from 2 to 30 parts by weight, preferably from 3 to 25 parts by weight,
especially from 4 to 20 parts by weight, of pentabromobenzyl polyacrylate,
C) from 0.3 to 12 parts by weight, preferably from 0.5 to 10 parts by weight,
especially from 1 to 8 parts by weight, of antimony compound(s), and
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D) from 0 to 90 parts by weight of polycarbonate and/or polyester carbonate,
wherein the sum of A) + B) + C) + D) is 100 and up to 10 parts by weight of
S polyalkylene terephthalate can be replaced by polyolefins.
The extrudates (films, sheets and wire-coatings) and moulded articles produced
by
the compression moulding process are obtainable from thermoplastic moulding
compositions containing the above-mentioned components A) to D). The
thermoplastic moulding compositions are distinguished by good flame-resistant
behaviour, without the thermoplastic matrix being damaged, in conjunction with
a
high surface quality and improved electrical properties and are especially
suitable for
the production of films and sheets owing to their good flow properties.
The invention relates also to the use of thermoplastic moulding compositions
containing the above-mentioned components in the production of flame-protected
extrudates (films, sheets and wire-coatings) and flame-protected moulded
articles
produced by the compression moulding process having improved properties in
respect of breaking elongation, stress at break and surface quality.
The term "films" usually refers to materials which can be rolled up, whereas
sheets
are generally stiff and hence cannot be rolled up.
Films within the scope of the invention generally have a thickness < 1200 p,m,
preferably from 25 to 1000 Vim, especially from 50 to 850 pm.
Sheets within the scope of the invention generally have a thickness of from
1.2 mm
to several centimetres, preferably from 1.2 mm to 4 cm, especially from 1.2 mm
to
2.5 cm.
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Component A
Polyalkylene terephthalates (component A) within the scope of the invention
are
reaction products of aromatic dicarboxylic acids or their reactive derivatives
(e.g.
dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or araliphatic
diols, and
mixtures of those reaction products.
Preferred polyalkylene terephthalates can be prepared from terephthalic acid
(or its
reactive derivatives) and aliphatic or cycloaliphatic diols having from 2 to
10 carbon
atoms by known methods (Kunststoff Handbuch, Vol. VIII, p. 695 ff, Karl-Hanser-
Verlag, Munich, 1973).
Preferred polyalkylene terephthalates contain at least 80 mol%, preferably 90
mol%,
based on the dicarboxylic acid, of terephthalic acid radicals and at least 80
mol%,
preferably at least 90 mol%, based on the diol component, of ethylene glycol
and/or
1,4-butanediol radicals or a mixture thereof with 1,4-cyclohexanediol.
The preferred polyalkylene terephthalates can contain, in addition to
terephthalic
acid radicals, up to 20 mol% of radicals of other aromatic dicarboxylic acids
having
from 8 to 14 carbon atoms or of aliphatic dicarboxylic acids having from 4 to
12
carbon atoms, such as radicals of phthalic acid, isophthalic acid, naphthalene-
2,6-
dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic acid, adipic acid,
sebacic
acid, azelaic acid, cyclohexanediacetic acid.
The preferred polyalkylene terephthalates can contain, in addition to ethylene
glycol
and/or 1,4-butanediol radicals, up to 20 mol% of other aliphatic diols having
from 3
to 12 carbon atoms or of cycloaliphatic diols having from 6 to 21 carbon
atoms, for
example radicals of 1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl
glycol, 1,5-
pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 3-
methyl-2,4-perltanediol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-
pentanediol
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and -1,6,2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 2,5-hexanediol,
1,4-di
((i-hydroxyethoxy)-benzene, 2,2-bis(4-hydroxycyclohexyl)-propane, 2,4-
dihydroxy
1,1,3,3-tetramethyl-cyclobutane, 2,2-bis(3-/3-hydroxyethoxyphenyl)-propane and
2,2-bis(4-hydroxypropoxyphenyl)-propane (DE-OS 24 07 674, 24 07 776, 27 1 S
932).
The polyalkylene terephthalates can be branched by the incorporation of
relatively
small amounts of tri- or tetra-hydric alcohols or of tri- or tetra-basic
carboxylic acids,
as are described, for example, in DE-OS 19 00 270 and US-A 3 692 744. Examples
of preferred branching agents are trimesic acid, trimellitic acid, trimethylol-
ethane
and -propane and pentaerythritol.
It is advisable to use not more than 1 mol% of the branching agent, based on
the acid
component.
Special preference is given to polyalkylene terephthalates that have been
prepared
solely from terephthalic acid and its reactive derivatives (e.g. its dialkyl
esters), diols
selected from ethylene glycol, 1,4-butanediol and 1,4-cyclohexanediol or
mixtures
thereof (polyethylene and polybutylene terephthalate), and mixtures of those
polyalkylene terephthalates.
Preferred polyalkylene terephthalates are also copolyesters which are prepared
from
at least two of the above-mentioned acid components and/or from at least two
of the
above-mentioned alcohol components, and especially preferred copolyesters are
poly-(ethylene glycoUl,4-butanediol) terephthalates.
The polyalkylene terephthalates preferably used as component A generally have
an
intrinsic viscosity of approximately from 0.4 to 1.5 dl/g, preferably from 0.5
to
1.3 dl/g, in each case measured in phenol/o-dichlorobenzene ( 1:1 parts by
weight) at
25°C.
°
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Component B
Pentabromobenzyl polyacrylate is generally known and is described, for
example, in
EP-A 344 700. It is available commercially (Dead Sea Bromine Group, Beer
Sheva,
Israel).
PBBPA can also be prepared in situ by the addition of pentabromobenzyl
monoacrylate to thermoplastic moulding compositions (EP-A 344 700).
Component C
Preferred antimony compounds are antimony trioxide and/or antimony pentoxide,
which are compounds which are generally known.
Component D
Polycarbonates are preferably used in an amount of from 0 to 75 parts by
weight,
based on the total amount of the moulding composition.
Polycarbonates can very especially preferably be added in an amount of from 20
to
70 parts by weight, based on the total amount of the moulding composition.
Aromatic polycarbonates and/or aromatic polyester carbonates according to
component D that are suitable according to the invention are known from the
literature or can be prepared by processes which are known from the literature
(for
the preparation of aromatic polycarbonates see, for example, Schnell,
"Chemistry
and Physics of Polycarbonates", Interscience Publishers, 1964, and DE-AS
1 495 626, DE-OS 2 232 877, DE-OS 2 703 376, DE-OS 2 714 544, DE-OS
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3 000 610, DE-OS 3 832 396; for the preparation of aromatic polyester
carbonates
see, for example, DE-OS 3 077 934).
The preparation of aromatic polycarbonates is carried out, for example, by
reacting
diphenols with carbonic acid halides, preferably phosgene, and/or with
aromatic
dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides,
according to the boundary surface process, optionally with the use of chain
terminators, for example monophenols, and optionally with the use of branching
agents having a functionality of three or more, for example triphenols or
tetraphenols.
Diphenols for the preparation of the aromatic polycarbonates and/or aromatic
polyester carbonates are preferably those of formula (I)
OH
(I)
HO
in which
A' represents a single bond, C,-CS-alkylene, CZ CS-alkylidene, CS-C6 cyclo-
alkylidene, -O-, -SO-, -CO-, -S-, -SOZ , C6 C,z arylene, which may be
condensed with further aromatic rings optionally containing hetero atoms, or
a radical of the formula
(II)
R6~z~ 7
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or a radical of formula (III)
Hs
-C ~ ~ CH3
I (III)
CHa
H3
the substituents B are each independently of the other C,-Cg alkyl, preferably
C,-C,
alkyl, especially methyl, halogen, preferably chlorine and/or bromine, C6 C,a
aryl, preferably phenyl, C7-C,Z aralkyl, phenyl-C,-C4 alkyl, preferably
benzyl,
x are each independently of the other 0, 1 or 2,
p , is 1 or 0, and
R6 and R' can be chosen individually for each Z and are each independently of
the
other hydrogen or C,-C6 alkyl, preferably hydrogen, methyl and/or ethyl,
Z represents carbon, and .
m represents an integer from 4 to 7, preferably 4 or 5,
with the proviso that at at least one Z atom,
R6 and R' are simultaneously alkyl.
Preferred diphenols are hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl,
bis(hydroxyphenyl)-C,-CS-alkanes, bis(hydroxyphenyl)-CS-C6 cycloalkanes, bis-
(hydroxyphenyl) ethers, bis(hydroxyphenyl) sulfoxides, bis(hydroxyphenyl)
ketones,
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bis(hydroxyphenyl)-sulfones and a,a-bis(hydroxyphenyl)-diisopropyl-benzenes,
as
well as their derivatives brominated and/or chlorinated at the nucleus.
Especially preferred diphenols are 4,4'-diphenylphenol, bisphenol A, 2,4-bis(4-
hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)-cyclohexane, 1,1-bis(4-
hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide,
4,4'
dihydroxydiphenylsulfone and their di- and tetra-brominated or -chlorinated
derivatives, such as, for example, 2,2-bis(3-chloro-4-hydroxyphenyl)-propane,
2,2
bis(3,5-dichloro-4-hydroxyphenyl)-propane or 2,2-bis(3,5-dibromo-4-hydroxy
phenyl)-propane.
Special preference is given to 2,2-bis(4-hydroxyphenyl)-propane (bisphenol A).
The diphenols can be used individually or in the form of any desired mixtures.
The diphenols are known from the literature or are obtainable by processes
which
are known from the literature.
Suitable chain terminators for the preparation of the thermoplastic, aromatic
polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or
2,4,6-tribromophenol, as well as long-chained alkylphenols, such as 4-(1,3-
tetra-
methylbutyl)-phenol according to DE-OS 2 842 005, or monoalkylphenols or
dialkylphenols having a total of from 8 to 20 carbon atoms in the alkyl
substituents,
such as 3,5-di-tert-butylphenol, p-isooctylphenol, p-tent-octylphenol, p-
dodecyl-
phenol and 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol.
The
amount of chain terminators to be used is generally from 0.5 mol% to 10 mol%,
based on the molar sum of the diphenols used in a particular case.
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The thermoplastic, aromatic polycarbonates have mean weight-average molecular
weights (Mw, measured, for example, by ultracentrifuge or scattered light
measurement) of from 10,000 to 200,000, preferably from 20,000 to 80,000.
The thermoplastic, aromatic polycarbonates can be branched in a known manner,
preferably by the incorporation of from 0.05 to 2.0 mol%, based on the sum of
the
diphenols used, of compounds having a functionality of three or more, for
example
compounds having three or more phenolic groups.
Both homopolycarbonates and copolycarbonates are suitable. For the preparation
of
copolycarbonates according to the invention as component A there may also be
used
from 1 to 25 wt.%, preferably from 2.5 to 25 wt.% (based on the total amount
of
diphenols to be used), of polydiorganosiloxanes having hydroxy-aryloxy
terminal
groups. Those compounds are known (see, for example, US patent 3 419 634) or
can
be prepared by processes which are known from the literature. The preparation
of
polydiorganosiloxane-containing copolycarbonates is described, for example, in
DE-OS 3 334 782.
Preferred polycarbonates, in addition to the homopolycarbonates of bisphenol
A, are
the copolycarbonates of bisphenol A with up to 15 mol%, based on the molar sum
of
diphenols, of diphenols other than those mentioned as being preferred or
especially
preferred, especially 2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane.
Aromatic dicarboxylic acid dihalides for the preparation of aromatic polyester
carbonates are preferably the diacid dichlorides of isophthalic acid,
terephthalic acid,
diphenyl ether 4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.
Special preference is given to mixtures of the diacid dichlorides of
isophthalic acid
and terephthalic acid in a ratio of from 1:20 to 20:1.
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In the preparation of polyester carbonates, a carbonic acid halide, preferably
phosgene, is additionally used concomitantly as difurlctional acid derivative.
There come into consideration as chain terminators for the preparation of the
aromatic polyester carbonates, in addition to the monophenols already
mentioned,
also their chlorocarbonic acid esters and the acid chlorides of aromatic
monocarboxylic acids, which may optionally be substituted by C,-CZi alkyl
groups
or by halogen atoms, as well as aliphatic CZ CZZ monocarboxylic acid
chlorides.
The amount of chain terminators is in each case from 0.1 to 10 mol%, based in
the
case of the phenolic chain terminators on moles of diphenols and in the case
of
monocarboxylic acid chloride chain terminators on moles of dicarboxylic acid
dichlorides.
1 S The aromatic polyester carbonates may also contain aromatic
hydroxycarboxylic
acids incorporated therein.
The aromatic polyester carbonates may be either linear or branched in a known
manner (see in this connection likewise DE-OS 2 940 024 and DE-OS 3 007 934).
There may be used as branching agents, for example, carboxylic acid chlorides
having a functionality of three or more, such as trimesic acid trichloride,
cyanuric
acid trichloride, 3,3'-4,4'-benzophenone-tetracarboxylic acid tetrachloride,
1,4,5,8-
naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid
tetrachloride, in
amounts of from 0.01 to 1.0 mol% (based on dicarboxylic acid dichlorides
used), or
phenols having a functionality of three or more, such as phloroglucinol, 4,6-
dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 2,4,4-dimethyl-2,4,6-tri-(4-
hydroxy-
phenyl)-heptane, 1,3, 5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-
hydroxyphenyl)-
ethane, tri-(4-hydroxyphenyl)-phenylmethane, 2,2-bis[4,4-bis(4-hydroxyphenyl)-
cyclohexyl]-propane, 2,4-bis(4-hydroxyphenyl-isopropyl)-phenol, tetra-(4-
hydroxy-
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phenyl)-methane, 2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-(4-
hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, tetra-(4-[4-hydroxyphenyl-
isopropyl]-phenoxy)-methane, 1,4-bis[4,4'-dihydroxytriphenyl)-methyl]-benzene,
in
amounts of from 0.01 to 1.0 mol%, based on diphenols used. Phenolic branching
agents can be used initially with the diphenols, acid chloride branching
agents can be
introduced together with the acid dichlorides.
The content of carbonate structural units in the thermoplastic, aromatic
polyester
carbonates can vary as desired.
The content of carbonate groups is preferably up to 100 mol%, especially up to
80 mol%, especially preferably up to 50 mol%, based on the sum of ester groups
and
carbonate groups.
Both the esters and the carbonates contained in the aromatic polyester
carbonates
can be present in the polycondensation product in the form of blocks or in a
randomly distributed manner.
The relative intrinsic viscosity (rare,) of the aromatic polyester carbonates
is in the
range of from 1.18 to 1.4, preferably from 1.22 to 1.3 (measured on solutions
of
0.5 g of polyester carbonate in 100 ml of methylene chloride solution at
25°C).
The thermoplastic, aromatic polycarbonates and polyester carbonates can be
used
alone or in any desired mixture with one another.
The aromatic polycarbonates can be prepared by known processes, for example by
melt transesterification of a corresponding bisphenol with diphenyl carbonate
and in
solution from bisphenols and phosgene. The solution may be homogeneous
(pyridine process) or heterogeneous (two-phase boundary surface process) (see
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H. Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Vol.
IX,
p. 33 et seq, Interscience Publ. 1964).
The aromatic polycarbonates generally have mean molecular weights M W of
approximately from 10,000 to 200,000, preferably from 20,000 to 80,000
(calculated
by gel chromatography after prior calibration).
Copolycarbonates within the scope of the invention are especially poly-
diorganosiloxane-polycarbonate block copolymers having a mean molecular weight
M W of approximately from 10,000 to 200,000, preferably from 20,000 to 80,000
(calculated by gel chromatography after prior calibration) and having a
content of
aromatic carbonate structural units of approximately from 75 to 97.5 wt.%,
preferably from 85 to 97 wt.%, and a content of polydiorganosiloxane
structural
units of approximately from 25 to 2.5 wt.%, preferably from 15 to 3 wt.%, the
block
copolymers being prepared starting from polydiorganosiloxanes containing a,co-
bis-
hydroxyaryloxy terminal groups and having a degree of polymerisation Pn of
from 5
to 100, preferably from 20 to 80.
The polydiorganosiloxane-polycarbonate block copolymers may also be a mixture
of
polydiorganosiloxane-polycarbonate block copolymers with conventional
polysiloxane-free, thermoplastic polycarbonates, the total content of
polydiorganosiloxane structural units in that mixture being approximately from
2.5
to 25 wt.%.
Such polydiorganosiloxane-polycarbonate block copolymers are characterised in
that
they contain in the polymer chain on the one hand aromatic carbonate
structural units
( 1 ) and on the other hand polydiorganosiloxanes containing aryloxy terminal
groups
(2)
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O
-O-Ar-O-C-O Ar-O- (1),
R R R~
- O-Ar-O - ( - ~ i-O-)a ( - ~ i-O-)e ( - ~ i-O-)~- Ar-O- {2),
R R' R'
in which
Ar are identical or different aryl radicals from diphenols, and
R and R' are identical or different and represent linear alkyl, branched
alkyl, alkenyl,
halogenated linear alkyl, halogenated branched alkyl, aryl or halogenated
aryl, but preferably methyl,
and
the number of diorganosiloxy units n=a+b+c is from 5 to 100, preferably from
20 to
80.
Alkyl in formula (2) above is, for example, C,-CZO alkyl; alkenyl in formula
(2)
above is, for example, Cz-C6 alkenyl; aryl in formula (2) above is C6 C,4
aryl. In the
above formula, halogenated means partially or completely chlorinated,
brominated
or fluorinated.
Examples of alkyls, alkenyls, aryls, halogenated alkyls and halogenated aryls
are
methyl, ethyl, propyl, n-butyl, tert-butyl, vinyl, phenyl, naphthyl,
chloromethyl,
perfluorobutyl, perfluorooctyl and chlorophenyl.
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Such polydiorganosiloxane-polycarbonate block copolyrners are known, for
example, from US-A 3 189 662; US-A 3 821 325 and US-A 3 832 419.
Preferred polydiorganosiloxane-polycarbonate block copolymers are prepared by
reacting polydiorganosiloxanes containing .a,co-bishydroxyaryloxy terminal
groups
together with other diphenols, optionally with the concomitant use of
branching
agents in the usual amounts, for example by the two-phase boundary surface
process
(see in this respect H. Schnell, Chemistry and Physics of Polycarbonates,
Polymer
Rev. Vol. IX, page 27 ff, Interscience Publishers New York 1964), the ratio of
the
difunctional phenolic reactants in each case being so selected that it results
in the
content of aromatic carbonate structural units and diorganosiloxy units
according to
the invention.
Such polydiorganosiloxanes containing a,c~-bishydroxyaryloxy terminal groups
are
known, for example, from US 3 419 634.
The thermoplastic moulding composition can contain up to 10 parts by weight,
especially from 1 to 8 parts by weight (based on a total weight of 100 parts
by
weight), of polyolefins. Suitable polyolefins are polymers of aliphatic
unsaturated
hydrocarbons, such as, for example, ethylene, propylene, butylene or
isobutylene,
which are obtained by conventional processes, for example radical
polymerisation,
and have mean weight-average molecular weights MW (measured by gel-
chromatographic methods) of from 3,000 to 3,000,000. Both high-pressure and
low-
pressure polyolefins can be used. Polyethylenes and polypropylenes are
preferred.
The moulding compositions may contain nucleating agents such as microtalc. The
moulding compositions may also contain conventional additives, such as
lubricants,
mould-release agents, processing stabilisers and anti-dripping agents (e.g.
polytetrafluoroethylene) as well as colourings and pigments.
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The sheets produced by the extrusion or compression moulding process can be
components from the electronics sector, which are desired to have good
electrical
properties with, at the same time, good flame-resistant behaviour and good
flowability and a high surface quality, without the thermoplastic matrix being
damaged.
There are accordingly used, for example, casing parts, plug boards and lamp
holders,
as well as parts from the motor vehicle sector.
Films produced from the moulding compositions may likewise be for the
electronics
sector, which films are desired to have good flame-resistant behaviour and
good
electrical properties, without the thermoplastic matrix being damaged.
Wire-coatings can be used, for example, for the electronics sector as well as
in
1 S automotive manufacture; they are desired to have good flame-resistant
behaviour, a
high level of electrical properties, high resistance to chemicals and a high
degree of
thermal stability, without the thermoplastic matrix being damaged.
For the production of the films, sheets and wire-coatings, the components are
mixed
and compounded by means of an extruder in the usual manner at temperatures of
approximately from 260°C to 320°C.
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Examples
Description of the test methods for testing moulded articles
Flame test according to UL 94 (IEC 707)
Bending test according to ISO 178
Melt volume rate (volume flow index) according to ISO 1133
Table 1
The electrical properties are measured as follows:
Electrical propertiesTest Units Standards Test
conditions specimens
Relative permittivity
(dielectric constant)100 Hz IEC 250 disk 80X2
Relative permittivity
(dielectric constant)1 MHz IEC 250 disk 80X2
Dielectric volume
resistivity Ohm~cm IEC 93 disk 80X2
Specific surface
resistivity Ohm IEC 93 disk 80X2
Dielectric.strength kV/mm IEC 243-1 disk 118X2
Tracking index test solutionstep IEC 112 disk 118X4
A
The components indicated in the Examples are mixed and compounded by means of
1 S an extruder under conventional conditions, and are then processed to test
specimens
in an injection-moulding machine under conventional PBT processing conditions
(composition temperature approximately 260°C).
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The test specimens are tested in respect of their properties.
The pentabromobenzyl polyacrylate (PBB-PA) used was Eurobrom FR 1025,
Eurobrom B.V. (NL) Rijswijk-Netherlands.
S
Example 1 according to the invention
79.0 wt.% polybutylene terephthalate (PBT)
(relative intrinsic viscosity 1.707-1.153, measured at T = 25°C in a
0.5% solution of phenol and o-dichlorobenzene, mixing ratio 1:1 parts
by weight)
15.0 wt.% PBB-PA
5.2 wt.% antimony trioxide
0.8 wt.% additives
Example 2 according to the invention
79.0 wt.% polybutylene terephthalate (PBT)
(relative intrinsic viscosity 1.834-1.875, measured at T = 25°C in a
0.5% solution of phenol and o-dichlorobenzene, mixing ratio 1:1 parts
by weight)
15.0 wt.% PBB-PA
5.2 wt.% antimony trioxide
0.8 wt.% additives
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Comparison Example 3
79.2 wt.% polybutylene terephthalate (PBT)
(relative intrinsic viscosity 1.707-1.153, measured at T = 25°C in a
0.5% solution of phenol and o-dichlorobenzene, mixing ratio 1:1 parts
S by weight)
15.0 wt.% epoxidised tetrabromobisphenol A
5.0 wt.% antimony trioxide
0.8 wt.% additives
Comparison Example 4
80.7 wt.% polybutylene terephthalate (PBT)
(relative intrinsic viscosity 1.643-1.705, measured at T = 25°C in a
0.5% solution of phenol and o-dichlorobenzene, mixing ratio 1:1 parts
by weight)
13.5 wt.% ethylene-bis-tetrabromophthalimide
5.0 wt.% antimony trioxide
0.8 wt.% additives
Example 5 according to the invention
91.4 wt.% polybutylene terephthalate (PBT)
(relative intrinsic viscosity 1.707-1.153, measured at T = 25°C in a
0.5% solution of phenol and o-dichlorobenzene, mixing ratio 1:1 parts
by weight)
6.0 wt.% PBB-PA
1:8 wt.% antimony trioxide
0.8 wt.% additives
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Table 2 (results)
Flame-protected
thermoplastic
moulding
compositions
ExampleExampleExampleExampleExample
1 2 3 4 5
PropertiesStandardsUnits Accor- Accor- Compa- Compa- Accor-
ding ding rison rison ding
to to to
the the the
inventioninvention invention
RelativeIEC 250 3.5 not aot 3.4 not tested
tested tested
permittivity
100 Hz
RelativeIEC 250 3.5 not 3.2 3.2 not tested
tested
permittivity
I MHZ
DielectricIEC 93 Ohm.cm 4.SE+16not > 10'5 > 10" not tested
tested
volume
resistivity
SpecificIEC 93 Ohm l.lE+17not > 10's > 10" not tested
tested
surface
resistivity
DielectricIEC 243 kV/mm 49 not 28 28 not tested
tested
strength
Flame UL 94
test
3.2 mm class VO VO VO VO VO
1.6 mm class VO VO VO VO V2
0.8 mm class VO VO VO VO not tested
0.4 mm class VO VO cannot cannot not tested
be be
producedproduced
Bending ISO 178
test
Flexural MPa 100 100 95 90 95
strength
Flexural % 5.5 5.6 5.5 5.0 7.5
elongation
Bending MPa 2800 2800 2700 2700 2600
modulus
MVR IS01133 cm'/10 22 17 15* 20 19
260C/2.16 min.
kg load
TrackingiEC 112 step 500 500 250 375 600
index
* Comparison Example 3 is in comparison with Examples 1 and 5
The Table shows that the test specimens produced from the moulding
compositions
according to the invention have a markedly better creep resistance, a
comparable or
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better flowability (MVR) and a higher level of mechanical properties than the
comparison test specimens. The moulding compositions according to the
invention
can also be processed to test specimens having thin wall thicknesses, so that
an
especially good behaviour in fire is achieved here. Comparison Examples 3 and
4
cannot be processed to test specimens having a thickness of 0.4 mm according
to the
flame test description.
The indicated components can also be mixed and processed to films in a film
extrusion machine under conventional PBT processing conditions (composition
temperature approximately 250°C).
Description of the test methods for testing films
Flame test according to LTL 94 (IEC 707)
The tests according to UL 94V and UL 94 VTM can be used for films. Sections
8.1
and 11.1 of UL 94 indicate the criteria for the selection of the test method.
Tensile test according to ISO 1184.
Films according to the invention having thicknesses in the range of from 0.1
mm to
0.8 mm are produced and tested in the flame test according to UL 94.
Example 1 according to the invention processed to a film:
With a film thickness of 0.6 mm, a V-0 was obtained in the test according to
UL 94V. With a film thickness of 0.1 mm, the test according to UL 94 VTM is
carried out and results in VTM-0.
Example 2 according to the invention:
Films according to the invention having thicknesses in the range of from 0.125
mm
to 0.75 mm are produced and tested in the flame test according to UL 94.
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Table 3 Results of the flame test (Example 2)
Film thickness/mm Test according to
UL 94 V UL 94 VTM
0.125 not tested VTM-0
0.250 V-0 VTM-0
-
0.375 V-0 V,hM-p
0.750 V-0 not tested
The stress at break and breaking elongation and the modulus of elasticity of
those
films are determined in the tensile test according to ISO 1884.
Table 4 Results of the mechanical properties (Example 2)
ThicknessStress Breaking Modulus
mm at break elongation of elasticity
MPa % MPa
longitudinaltransverselongitudinaltransverselongitudinaltransverse
0.125 37 41 3.4 12.2 2550 2500
0.175 46 36 3.4 17.6 2590 2515
0.250 44 43 6.4 5.4 2730 2620
0.375 43 46 12.3 10.0 2920 2910
0.450 45 50 5.2 4.2 3070 2910
0.500 50 48 4.5 8.6 3100 3140
0.625 52 52 10.0 3.8 3190 3300
0.750 52 51 3.9 7.3 3420 3290
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Comparison Example 3
The product could not be processed to films (tearing, surfaces greatly
damaged).
Comparison Example 4
The product could not be processed to films (tearing, surfaces greatly
damaged).
In contrast to the comparison tests, the moulding compositions according to
the
invention can be processed to films which have a high surface quality,
especially in
respect of shine and uniformity. At the same time, excellent behaviour in fire
is
achieved, while the level of mechanical properties is high.
